U.S. patent application number 17/382411 was filed with the patent office on 2021-11-18 for orthodontic articles prepared using a polycarbonate diol, and methods of making same.
This patent application is currently assigned to 3M Innovative Properties Company. The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Ian Dailey, David B. Olson.
Application Number | 20210355262 17/382411 |
Document ID | / |
Family ID | 1000005740501 |
Filed Date | 2021-11-18 |
United States Patent
Application |
20210355262 |
Kind Code |
A1 |
Dailey; Ian ; et
al. |
November 18, 2021 |
ORTHODONTIC ARTICLES PREPARED USING A POLYCARBONATE DIOL, AND
METHODS OF MAKING SAME
Abstract
The present disclosure provides an orthodontic article including
the reaction product of the photopolymerizable composition. The
photopolymerizable composition includes i) a monofunctional
(meth)acrylate monomer whose cured homopolymer has a glass
transition temperature of 90 degrees Celsius or greater; ii) a
photoinitiator; and iii) a polymerization reaction product of
components. The components include 1) an isocyanate; 2) a
(meth)acrylate mono-ol; 3) a polycarbonate diol; and 4) a catalyst.
Further, the present disclosure provides a method of making an
orthodontic article. The method includes obtaining a
photopolymerizable composition and selectively curing the
photopolymerizable composition to form an orthodontic article.
Further, methods are provided, including receiving, by a
manufacturing device having one or more processors, a digital
object comprising data specifying an orthodontic article; and
generating, with the manufacturing device by an additive
manufacturing process, the orthodontic article based on the digital
object. A system is also provided, including a display that
displays a 3D model of an orthodontic article; and one or more
processors that, in response to the 3D model selected by a user,
cause a 3D printer to create a physical object of an orthodontic
article.
Inventors: |
Dailey; Ian; (Maplewood,
MN) ; Olson; David B.; (Hudson, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
1000005740501 |
Appl. No.: |
17/382411 |
Filed: |
July 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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17042384 |
Sep 28, 2020 |
11104758 |
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PCT/US2019/033252 |
May 21, 2019 |
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17382411 |
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62692456 |
Jun 29, 2018 |
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62736031 |
Sep 25, 2018 |
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62769421 |
Nov 19, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 18/222 20130101;
A61C 7/002 20130101; C08G 2650/16 20130101; B29C 71/0009 20130101;
B33Y 40/20 20200101; C08K 5/3437 20130101; B29C 2071/0027 20130101;
C08G 18/227 20130101; B33Y 30/00 20141201; C08G 64/305 20130101;
B29C 71/02 20130101; C08G 18/672 20130101; B33Y 70/00 20141201;
C08G 18/44 20130101; A61C 7/08 20130101; B29C 71/04 20130101; A61C
13/0019 20130101; B33Y 80/00 20141201; B33Y 10/00 20141201; C08G
18/3206 20130101; C08G 18/246 20130101 |
International
Class: |
C08G 18/44 20060101
C08G018/44; B33Y 10/00 20060101 B33Y010/00; B33Y 70/00 20060101
B33Y070/00; B33Y 80/00 20060101 B33Y080/00; B33Y 40/20 20060101
B33Y040/20; A61C 7/00 20060101 A61C007/00; A61C 7/08 20060101
A61C007/08; A61C 13/00 20060101 A61C013/00; B29C 71/00 20060101
B29C071/00; B29C 71/02 20060101 B29C071/02; B29C 71/04 20060101
B29C071/04; C08G 18/22 20060101 C08G018/22; C08G 18/24 20060101
C08G018/24; C08G 18/32 20060101 C08G018/32; C08G 18/67 20060101
C08G018/67; C08G 64/30 20060101 C08G064/30; C08K 5/3437 20060101
C08K005/3437 |
Claims
1. A compound of Formula (V): ##STR00025##
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 17/042,384, filed Sep. 28, 2020, which is a national stage
filing under 35 U.S.C. 371 of PCT/US2019/033252, filed May 21,
2019, which claims the benefit of U.S. Application No. 62/692,456,
filed Jun. 29, 2018; U.S. Application No. 62/736,031, filed Sep.
25, 2018; and U.S. Application No. 62/769,421, filed Nov. 19, 2018,
the disclosures of which are incorporated by reference in their
entireties herein.
TECHNICAL FIELD
[0002] The present disclosure broadly relates to orthodontic
articles and methods of making the orthodontic articles, such as
additive manufacturing methods.
BACKGROUND
[0003] The use of stereolithography and inkjet printing to produce
three-dimensional articles has been known for a relatively long
time, and these processes are generally known as methods of so
called 3D printing (or additive manufacturing). In vat
polymerization techniques (of which stereolithography is one type),
the desired 3D article is built up from a liquid, curable
composition with the aid of a recurring, alternating sequence of
two steps: in the first step, a layer of the liquid, curable
composition, one boundary of which is the surface of the
composition, is cured with the aid of appropriate radiation within
a surface region which corresponds to the desired cross-sectional
area of the shaped article to be formed, at the height of this
layer, and in the second step, the cured layer is covered with a
new layer of the liquid, curable composition, and the sequence of
steps is repeated until a so-called green body (i.e., gelled
article) of the desired shape is finished. This green body is often
not yet fully cured and must, usually, be subjected to post-curing.
The mechanical strength of the green body immediately after curing,
otherwise known as green strength, is relevant to further
processing of the printed articles.
[0004] Other 3D printing techniques use inks that are jetted
through a print head as a liquid to form various three-dimensional
articles. In operation, the print head may deposit curable
photopolymers in a layer-by-layer fashion. Some jet printers
deposit a polymer in conjunction with a support material or a
bonding agent. In some instances, the build material is solid at
ambient temperatures and converts to liquid at elevated jetting
temperatures. In other instances, the build material is liquid at
ambient temperatures.
SUMMARY
[0005] Existing printable/polymerizable resins tend to be too
brittle (e.g., low elongation, short-chain crosslinked bonds,
thermoset composition, and/or high glass transition temperature)
for a resilient oral appliance such as an aligner. An aligner or
other appliance prepared from such resins could easily break in the
patient's mouth during treatment, creating material fragments that
may abrade or puncture exposed tissue or be swallowed. These
fractures at the very least interrupt treatment and could have
serious health consequences for the patient. Thus, there is a need
for curable liquid resin compositions that are tailored and well
suited for creation of resilient articles using 3D printing (e.g.,
additive manufacturing) method. Preferably, curable liquid resin
compositions to be used in the vat polymerization 3D printing
process have low viscosity, a proper curing rate, and excellent
mechanical properties in the final cured article. In contrast,
compositions for inkjet printing processes need to be much lower
viscosity to be able to be jetted through nozzles, which is not the
case for most vat polymerization resins.
[0006] In a first aspect, an orthodontic article is provided. The
orthodontic article includes a) a polymerized reaction product of a
photopolymerizable composition. The photopolymerizable composition
includes i) a monofunctional (meth)acrylate monomer whose cured
homopolymer has a T.sub.g of 90.degree. C. or greater; ii) a
photoinitiator; and iii) a polymerization reaction product of
components. The components of iii) include 1) an isocyanate; 2) a
(meth)acrylate mono-ol; a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 3) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is (an integer of) 2 to 23.
The polymerized reaction product of the photopolymerizable
composition has a shape of the orthodontic article.
[0007] In a second aspect, a method of making an orthodontic
article is provided. The method includes a) obtaining a
photopolymerizable composition according to the first aspect; b)
selectively curing the photopolymerizable composition; and c)
repeating steps a) and b) to form multiple layers and create the
orthodontic article.
[0008] In a third aspect, a non-transitory machine readable medium
is provided. The non-transitory machine readable medium includes
data representing a three-dimensional model of an orthodontic
article, when accessed by one or more processors interfacing with a
3D printer, causes the 3D printer to create an orthodontic article
comprising a reaction product of a photopolymerizable composition
according to the first aspect.
[0009] In a fourth aspect, a method is provided. The method
includes a) retrieving, from a non-transitory machine readable
medium, data representing a 3D model of an article; b) executing,
by one or more processors, a 3D printing application interfacing
with a manufacturing device using the data; and c) generating, by
the manufacturing device, a physical object of the orthodontic
article. The orthodontic article includes a reaction product of a
photopolymerizable composition according to the first aspect.
[0010] In a fifth aspect, another method is provided. The method
includes a) receiving, by a manufacturing device having one or more
processors, a digital object comprising data specifying a plurality
of layers of an orthodontic article; and b) generating, with the
manufacturing device by an additive manufacturing process, the
orthodontic article based on the digital object. The orthodontic
article includes a reaction product of a photopolymerizable
composition according to the first aspect.
[0011] In a sixth aspect, a system is provided. The system includes
a) a display that displays a 3D model of an orthodontic article;
and b) one or more processors that, in response to the 3D model
selected by a user, cause a 3D printer to create a physical object
of an orthodontic article. The orthodontic article includes a
reaction product of a photopolymerizable composition.
[0012] In a seventh aspect, a compound is provided. The compound is
of Formula (V):
##STR00001##
[0013] The compound of the seventh aspect can advantageously be
used as a UV absorber in orthodontic articles and methods according
to the first through fifth aspects.
[0014] Clear tray aligners and tensile bars made according to at
least certain embodiments of this disclosure were found to show low
brittleness, good resistance to water, and good toughness.
[0015] The above summary of the present disclosure is not intended
to describe each disclosed embodiment or every implementation of
the present disclosure. The description that follows more
particularly exemplifies illustrative embodiments. In several
places throughout the application, guidance is provided through
lists of examples, which examples can be used in various
combinations. In each instance, the recited list serves only as a
representative group and should not be interpreted as an exclusive
list.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a flowchart of a process for building an article
using the photopolymerizable compositions disclosed herein.
[0017] FIG. 2 is a generalized schematic of a stereolithography
apparatus.
[0018] FIG. 3 is an isometric view of a printed clear tray aligner,
according to one embodiment of the present disclosure.
[0019] FIG. 4 is a flowchart of a process for manufacturing a
printed orthodontic appliance according to the present
disclosure.
[0020] FIG. 5 is a generalized schematic of an apparatus in which
radiation is directed through a container.
[0021] FIG. 6 is a block diagram of a generalized system 600 for
additive manufacturing of an article.
[0022] FIG. 7 is a block diagram of a generalized manufacturing
process for an article.
[0023] FIG. 8 is a high-level flow chart of an exemplary article
manufacturing process.
[0024] FIG. 9 is a high-level flow chart of an exemplary article
additive manufacturing process.
[0025] FIG. 10 is a schematic front view of an exemplary computing
device 1000.
[0026] While the above-identified figures set forth several
embodiments of the disclosure other embodiments are also
contemplated, as noted in the description. The figures are not
necessarily drawn to scale. In all cases, this disclosure presents
the invention by way of representation and not limitation. It
should be understood that numerous other modifications and
embodiments can be devised by those skilled in the art, which fall
within the scope and spirit of the principles of the invention.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0027] As used herein, "aliphatic group" means a saturated or
unsaturated linear, branched, or cyclic hydrocarbon group. This
term is used to encompass alkyl, alkenyl, and alkynyl groups, for
example.
[0028] As used herein, "alkyl" means a linear or branched, cyclic
or acyclic, saturated monovalent hydrocarbon having from one to
thirty-two carbon atoms, e.g., methyl, ethyl, 1-propyl, 2-propyl,
pentyl, and the like.
[0029] As used herein, "alkylene" means a linear saturated divalent
hydrocarbon having from one to twelve carbon atoms or a branched
saturated divalent hydrocarbon radical having from three to twelve
carbon atoms, e.g., methylene, ethylene, propylene,
2-methylpropylene, pentylene, hexylene, and the like.
[0030] As used herein, "alkenyl" refers to a monovalent linear or
branched unsaturated aliphatic group with one or more carbon-carbon
double bonds, e.g., vinyl. Unless otherwise indicated, the alkenyl
groups typically contain from one to twenty carbon atoms.
[0031] As used herein, the term "arylene" refers to a divalent
group that is carbocyclic and aromatic. The group has one to five
rings that are connected, fused, or combinations thereof. The other
rings can be aromatic, non-aromatic, or combinations thereof. In
some embodiments, the arylene group has up to 5 rings, up to 4
rings, up to 3 rings, up to 2 rings, or one aromatic ring. For
example, the arylene group can be phenylene.
[0032] As used herein, "aralkylene" refers to a divalent group that
is an alkylene group substituted with an aryl group or an alkylene
group attached to an arylene group. The term "alkarylene" refers to
a divalent group that is an arylene group substituted with an alkyl
group or an arylene group attached to an alkylene group. Unless
otherwise indicated, for both groups, the alkyl or alkylene portion
typically has from 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to
6 carbon atoms, or 1 to 4 carbon atoms. Unless otherwise indicated,
for both groups, the aryl or arylene portion typically has from 6
to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6
to 12 carbon atoms, or 6 to 10 carbon atoms.
[0033] As used herein, the term "essentially free" in the context
of a composition being essentially free of a component, refers to a
composition containing less than 1% by weight (wt. %), 0.5 wt. % or
less, 0.25 wt. % or less, 0.1 wt. % or less, 0.05 wt. % or less,
0.001 wt. % or less, or 0.0001 wt. % or less of the component,
based on the total weight of the composition.
[0034] As used herein, the term "glass transition temperature"
(T.sub.g), of a polymer refers to the transition of a polymer from
a glassy state to a rubbery state and can be measured using
Differential Scanning Calorimetry (DSC), such as at a heating rate
of 10.degree. C. per minute in a nitrogen stream. When the T.sub.g
of a monomer is mentioned, it is the T.sub.g of a homopolymer of
that monomer. The homopolymer must be sufficiently high molecular
weight such that the T.sub.g reaches a limiting value, as it is
generally appreciated that a T.sub.g of a homopolymer will increase
with increasing molecular weight to a limiting value. The
homopolymer is also understood to be substantially free of
moisture, residual monomer, solvents, and other contaminants that
may affect the T.sub.g. A suitable DSC method and mode of analysis
is as described in Matsumoto, A. et. al., J. Polym. Sci. A., Polym.
Chem. 1993, 31, 2531-2539.
[0035] As used herein, the terms "hardenable" refers to a material
that can be cured or solidified, e.g., by heating to remove
solvent, heating to cause polymerization, chemical crosslinking,
radiation-induced polymerization or crosslinking, or the like.
[0036] As used herein, "curing" means the hardening or partial
hardening of a composition by any mechanism, e.g., by heat, light,
radiation, e-beam, microwave, chemical reaction, or combinations
thereof.
[0037] As used herein, "cured" refers to a material or composition
that has been hardened or partially hardened (e.g., polymerized or
crosslinked) by curing.
[0038] As used herein, "integral" refers to being made at the same
time or being incapable of being separated without damaging one or
more of the (integral) parts.
[0039] As used herein, the term "(meth)acrylate" is a shorthand
reference to acrylate, methacrylate, or combinations thereof,
"(meth)acrylic" is a shorthand reference to acrylic, methacrylic,
or combinations thereof, and "(meth)acryl" is a shorthand reference
to acryl and methacryl groups. "Acryl" refers to derivatives of
acrylic acid, such as acrylates, methacrylates, acrylamides, and
methacrylamides. By "(meth)acryl" is meant a monomer or oligomer
having at least one acryl or methacryl groups, and linked by an
aliphatic segment if containing two or more groups. As used herein,
"(meth)acrylate-functional compounds" are compounds that include,
among other things, a (meth)acrylate moiety.
[0040] As used herein, "polymerizable composition" means a
hardenable composition that can undergo polymerization upon
initiation (e.g., free-radical polymerization initiation).
Typically, prior to polymerization (e.g., hardening), the
polymerizable composition has a viscosity profile consistent with
the requirements and parameters of one or more 3D printing systems.
In some embodiments, for instance, hardening comprises irradiating
with actinic radiation having sufficient energy to initiate a
polymerization or cross-linking reaction. For instance, in some
embodiments, ultraviolet (UV) radiation, e-beam radiation, or both,
can be used. When actinic radiation can be used, the polymerizable
composition is referred to as a "photopolymerizable
composition".
[0041] As used herein, a "resin" contains all polymerizable
components (monomers, oligomers and/or polymers) being present in a
hardenable composition. The resin may contain only one
polymerizable component compound or a mixture of different
polymerizable compounds.
[0042] As used herein, the "residue of a diisocyanate", is the
structure of the diisocyanate after the --NCO groups are removed.
For example, 1,6-hexamethylene diisocyanate has the structure
OCN--(CH.sub.2).sub.6--NCO, and its residue, Rai, after removal of
the isocyanate groups is --(CH.sub.2).sub.6--.
[0043] As used herein, the "residue of a polycarbonate polyol", is
the structure of the polycarbonate polyol after the --OH groups are
removed. For example, a polycarbonate diol having the structure
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH, has a residue,
R.sub.dOH, after removal of the end --OH groups, of
--R.sub.1--O--C(.dbd.O)--(O--R.sub.1--O--C(.dbd.O)).sub.m-1--O--R.sub.2---
, wherein each R.sub.1 in each repeat unit and R.sub.2 is
independently an aliphatic, cycloaliphatic, or
aliphatic/cycloaliphatic alkylene group and m is 2 to 23. Examples
of R.sub.1 and R.sub.2 groups include
--CH.sub.2--CH.sub.2--CH(CH.sub.3)--CH.sub.2--CH.sub.2--,
--CH.sub.2--C(CH.sub.3).sub.2--CH.sub.2--, --(CH.sub.2).sub.6--,
--(CH.sub.2).sub.9--, and --(CH.sub.2).sub.10--.
[0044] As used herein, "thermoplastic" refers to a polymer that
flows when heated sufficiently above its glass transition point and
become solid when cooled.
[0045] As used herein, "thermoset" refers to a polymer that
permanently sets upon curing and does not flow upon subsequent
heating. Thermoset polymers are typically crosslinked polymers.
[0046] As used herein, "occlusal" means in a direction toward the
outer tips of the patient's teeth; "facial" means in a direction
toward the patient's lips or cheeks; and "lingual" means in a
direction toward the patient's tongue.
[0047] The words "preferred" and "preferably" refer to embodiments
of the disclosure that may afford certain benefits, under certain
circumstances. However, other embodiments may also be preferred,
under the same or other circumstances. Furthermore, the recitation
of one or more preferred embodiments does not imply that other
embodiments are not useful, and is not intended to exclude other
embodiments from the scope of the disclosure.
[0048] In this application, terms such as "a", "an", and "the" are
not intended to refer to only a singular entity, but include the
general class of which a specific example may be used for
illustration. The terms "a", "an", and "the" are used
interchangeably with the term "at least one." The phrases "at least
one of" and "comprises at least one of" followed by a list refers
to any one of the items in the list and any combination of two or
more items in the list.
[0049] As used herein, the term "or" is generally employed in its
usual sense including "and/or" unless the content clearly dictates
otherwise.
[0050] The term "and/or" means one or all of the listed elements or
a combination of any two or more of the listed elements.
[0051] Also herein, all numbers are assumed to be modified by the
term "about" and preferably by the term "exactly." As used herein
in connection with a measured quantity, the term "about" refers to
that variation in the measured quantity as would be expected by the
skilled artisan making the measurement and exercising a level of
care commensurate with the objective of the measurement and the
precision of the measuring equipment used. Also herein, the
recitations of numerical ranges by endpoints include all numbers
subsumed within that range as well as the endpoints (e.g., 1 to 5
includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).
[0052] As used herein as a modifier to a property or attribute, the
term "generally", unless otherwise specifically defined, means that
the property or attribute would be readily recognizable by a person
of ordinary skill but without requiring absolute precision or a
perfect match (e.g., within +/-20% for quantifiable properties).
The term "substantially", unless otherwise specifically defined,
means to a high degree of approximation (e.g., within +/-10% for
quantifiable properties) but again without requiring absolute
precision or a perfect match. Terms such as same, equal, uniform,
constant, strictly, and the like, are understood to be within the
usual tolerances or measuring error applicable to the particular
circumstance rather than requiring absolute precision or a perfect
match.
[0053] In a first aspect, the present disclosure provides an
orthodontic article. The orthodontic article includes: [0054] a) a
polymerized reaction product of a photopolymerizable composition
comprising: [0055] i) a monofunctional (meth)acrylate monomer whose
cured homopolymer has a T.sub.g of 90.degree. C. or greater; [0056]
ii) a photoinitiator; and [0057] iii) a polymerization reaction
product of components, the components comprising: [0058] 1) an
isocyanate; [0059] 2) a (meth)acrylate mono-ol; [0060] 3) a
polycarbonate diol of Formula (I):
[0060] H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I) [0061]
wherein each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or [0062] aliphatic/cycloaliphatic alkylene group
and an average number of carbon atoms in a combination of all the
R.sub.1 and R.sub.2 groups is 4 to 10, and m is 2 to 23; and [0063]
4) a catalyst; [0064] wherein the polymerized reaction product has
a shape of the orthodontic article.
[0065] The components (i) through (iii) (and 1) through 4)) are
discussed in detail below.
Monofunctional (Meth)Acrylate Monomer
[0066] In any embodiment, the photopolymerizable composition
comprises a monofunctional (meth)acrylate monomer having a high
glass transition temperature (T.sub.g), i.e., whose cured
homopolymer has a T.sub.g of 90.degree. C. or greater. In some
embodiments, a monofunctional (meth)acrylate monomer is present
whose cured homopolymer has a T.sub.g of 100.degree. C. or greater,
110.degree. C. or greater, 120.degree. C. or greater, 125.degree.
C. or greater, 130.degree. C. or greater, 135.degree. C. or
greater, 140.degree. C. or greater, 145.degree. C. or greater,
150.degree. C. or greater, 155.degree. C. or greater, 160.degree.
C. or greater, 165.degree. C. or greater, 170.degree. C. or
greater, 175.degree. C. or greater, 180.degree. C. or greater,
185.degree. C. or greater, 190.degree. C. or greater, or even
195.degree. C. or greater. In select embodiments, a monofunctional
(meth)acrylate monomer is present whose cured homopolymer has a
T.sub.g of 150.degree. C. or greater, 170.degree. C. or greater, or
180.degree. C. or greater. The T.sub.g of the homopolymer of the
monofunctional (meth)acrylate monomer is typically no greater than
about 260.degree. C. For example, 1-adamantyl methacrylate
decomposes at about 260.degree. C. In some embodiments, the T.sub.g
of the homopolymer of the monofunctional (meth)acrylate monomer is
no greater than 255.degree. C., 250.degree. C., 245.degree. C.,
240.degree. C., 235.degree. C., 230.degree. C., 225.degree. C.,
220.degree. C., 215.degree. C., 210.degree. C., 205.degree. C. or
200.degree. C. The inclusion of one or more monofunctional
(meth)acrylate monomers whose cured homopolymer has a T.sub.g of
90.degree. C. or greater in a photopolymerizable composition
contributes to increasing the relaxation modulus of a
photopolymerization reaction product of the composition as measured
after soaking in deionized water. Often, the T.sub.g of a
homopolymer of a monomer can be found in the literature, such as in
Table 1 below. Table 1 includes the reported T.sub.g of the
homopolymer of a number of monofunctional (meth)acrylate monomers
and the literature source of the reported T.sub.g.
[0067] In some embodiments, the monofunctional (meth)acrylate
monomer comprises a cycloaliphatic monofunctional (meth)acrylate.
Suitable monofunctional (meth)acrylate monomers include for
instance and without limitation, dicyclopentadienyl acrylate,
dicyclopentanyl acrylate, dimethyl-1-adamantyl acrylate, cyclohexyl
methacrylate, butyl methacrylate (e.g., tert-butyl methacrylate),
3,3,5-trimethylcyclohexyl methacrylate,
butyl-cyclohexylmethacrylate (e.g.,
cis-4-tert-butyl-cyclohexylmethacrylate, 73/27
trans/cis-4-tert-butylcyclohexylmethacrylate, or
trans-4-tert-butylcyclohexyl methacrylate), 2-decahydronapthyl
methacrylate, 1-adamantyl acrylate, dicyclopentadienyl
methacrylate, dicyclopentanyl methacrylate, isobornyl methacrylate
(e.g., d,l-isobornyl methacrylate), dimethyl-1-adamantyl
methacrylate, bornyl methacrylate (e.g., d,l-bornyl methacrylate),
3-tetracyclo[4.4.0.1.1]dodecyl methacrylate, 1-adamantyl
methacrylate, isobornyl acrylate, or combinations thereof. In an
embodiment, the monofunctional (meth)acrylate monomer comprises
isobornyl methacrylate.
[0068] In certain embodiments, the weight ratio of the
monofunctional (meth)acrylate monomer to the polyurethane
(meth)acrylate polymer is 60:40 to 40:60, 55:45 to 45:55, or 50:50.
Often, the monofunctional (meth)acrylate monomer is present in an
amount of 40 parts or more by weight per 100 parts of the total
photopolymerizable composition, 45 parts or more, 46 parts or more,
47 parts or more, 48 parts or more, 49 parts or more, or 50 parts
or more; and 65 parts or less, 64 parts or less, 63 parts or less,
62 parts or less, 61 parts or less, 60 parts or less, 59 parts or
less, 58 parts or less, 57 parts or less, 56 parts or less, or 55
parts or less, by weight per 100 parts of the total
photopolymerizable composition.
[0069] In some embodiments of the invention, the cured material
will be in contact with an aqueous environment. In those cases, it
is advantageous to utilize materials which have low affinity for
water. The affinity for water of certain (meth)acrylate monomers
can be estimated by the calculation of a partition coefficient (P)
between water and an immiscible solvent, such as octanol. This can
serve as a quantitative descriptor of hydrophilicity or
lipophilicity. The octanol/water partition coefficient can be
calculated by software programs such as ACD ChemSketch, (Advanced
Chemistry Development, Inc., Toronto, Canada) using the log of
octanol/water partition coefficient (log P) module. In embodiments
of the present invention, the calculated log P value is greater
than 1, 1.5, 2, 2.5, 3, 3.5, or 4. The calculated log P value is
typically no greater than 12.5. In some embodiments, the calculated
log P value is no greater than 12, 11.5, 11, 10.5, 10, 9.5, 9, 8.5,
8, 7.5, 7, 6.5, 6, or 5.5. Moreover, in some embodiments,
photopolymerizable compositions exclude the presence of a
significant amount of hydrophilic (meth)acrylate monomers by being
essentially free of any monofunctional (meth)acrylate monomer
having a log P value of less than 3, less than 2, or less than
1.
[0070] In some embodiments, photopolymerizable compositions contain
hydrophilic (meth)acrylate monomers or polymers (e.g., hydrophilic
urethane (meth)acrylate polymer) having a log P value of less than
3, less than 2, or less than 1, in an amount of 25% by weight or
less, based on the total weight of the photopolymerizable
composition, such as 23%, 21%, 20%, 19%, 17%, 15%, 13%, or 11% or
less of hydrophilic components; and 1% by weight or more, 2%, 3%,
4%, 5%, 7%, 9%, or 10% or more hydrophilic components, for example
1% to 25% by weight, based on the total weight of the
photopolymerizable composition. In some embodiments, the
combination of a hydrophilic component and a monofunctional
(meth)acrylate monomer whose cured homopolymer has a T.sub.g of
150.degree. C. or greater can impart advantageous properties to an
article, for instance, 20% by weight or more, 22%, 25%, 27%, 30%,
32%, 35%, 37%, 40%, 42%, 45%, 47%, or 50% by weight or more of a
monofunctional (meth)acrylate monomer whose cured homopolymer has a
T.sub.g of 150.degree. C. may be included when 1% to 25% by weight
of a hydrophilic component is present, each based on the total
weight of the photopolymerizable composition.
TABLE-US-00001 TABLE 1 Reported glass transition temperature
(T.sub.g) and calculated log P (log of octanol/water partition
coefficient) of homopolymers of monofunctional (meth)acrylate
monomers. T.sub.g Calculated Monomer (.degree. C.) T.sub.g
Reference log P 3,3,5-trimethylcyclohexyl 15 Hopfinger et. al.; J.
4.38 acrylate Polym. Sci. B., Polym. Phys. 1988, 26, 2007
d,l-isobornyl acrylate 94 Jakubowski et. al. 4.22 Polymer, 2008,
49, 1567 dicyclopentanyl acrylate 103 U.S. Pat. No. 4,591,626 3.69
3,5-dimethyl-1-adamantyl 105 Matsumoto, A. et. al. 4.63 acrylate
Macromolecules 1991, 24, 4017 cyclohexyl methacrylate 107 Wilson,
P.S., Simha, R.; 3.41 Macromolecules, 1973, 95, 3, 902 tert-butyl
methacrylate 113 Matsumoto, A. et. al. 2.57 Macromolecules 1991,
24, 4017 3,3,5-trimethylcyclohexyl 125 Hopfinger et. al.; J. 4.93
methacrylate Polym. Sci. B., Polym. Phys. 1988, 26, 2007
cis-4-tert-butyl-cyclo- 132 Matsumoto, A. et. al. 5.13
hexylmethacrylate Macromolecules 1993, 26, 7, 1659
2-decahydronapthyl 145 Matsumoto, A. et. al., J. 4.95 methacrylate
Polym. Sci. A., Polym. Chem. 1993, 31, 2531 1-adamantyl acrylate
153 Matsumoto, A. et. al. 3.68 Macromolecules 1991, 24, 4017
Mixture of 73% 163 Matsumoto, A. et. al. 5.13
trans-4-tert-butylcyclohexyl- Macromolecules methacrylate/27% 1993,
26, 7, 1659 cis-4-tert-butyl- cyclohexylmethacrylate
dicyclopentanyl methacrylate 173 U.S. Pat. No. 4,591,626 4.24
trans-4-tert-butylcyclohexyl 178 Matsumoto, A. et. al. 5.13
methacrylate Macromolecules 1993, 26, 7, 1659 d,l-isobornyl
methacrylate 191 Matsumoto, A. et. al., 4.77 J. Polym. Sci. A.,
Polym. Chem. 1993, 31, 2531 3,5-dimethyl-1-adamantyl 194 Matsumoto,
A. et. al. 5.19 methacrylate Macromolecules 1991, 24, 4017
d,l-bornyl methacrylate 194 Matsumoto, A. et. al., 4.77 J. Polym.
Sci. A., Polym. Chem. 1993, 31, 2531 3-tetracyclo[4.4.0.1.1]dode-
199 Matsumoto, A. et. al., 4.66 cyl methacrylate J. Polym. Sci. A.,
Polym. Chem. 1993, 31, 2531 1-adamantyl methacrylate >253
Matsumoto, A. et. al. 4.23 Macromolecules 1991, 24, 4017
2-ethylhexyl methacrylate -10 Fleischhaker et. al., 4.88 Macromol.
Chem. Phys. 2014, 215, 1192. tetrahydrofurfuryl 60 E.I. du Pont de
Nemours 1.38 methacrylate & Co., Ind. Eng. Chem., 1936, 28,
1160, 2-phenoxyethyl methacrylate 47 Song et. al.; J. Phys. 3.26
Chem. B 2010, 114, 7172 N-vinyl pyrrolidone 180 Turner et. al;
Polymer, 0.37 1985, 26, 757 carboxyethyl acrylate <30 Fang et.
al.; Int. J. 0.60 Adhes. and Adhes. 84 (2018) 387-393
2-hydroxyethyl methacrylate 105 Russell et. al.; J. 0.50 Polym.
Sci. Polym. Phys, 1980, 18, 1271 acryloyl morpholine 147 Elles, J.;
Chimie -0.94 Moderne, 1959, 4, 26, 53
Photoinitiator
[0071] Photopolymerizable compositions of the present disclosure
include at least one photoinitiator. Suitable exemplary
photoinitiators are those available under the trade designations
OMNIRAD from IGM Resins (Waalwijk, The Netherlands) and include
1-hydroxycyclohexyl phenyl ketone (OMNIRAD 184),
2,2-dimethoxy-1,2-diphenylethan-1-one (OMNIRAD 651), bis(2,4,6
trimethylbenzoyl)phenylphosphineoxide (OMNIRAD 819),
1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one
(OMNIRAD 2959),
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (OMNIRAD
369),
2-Dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-but-
an-1-one (OMNIRAD 379),
2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (OMNIRAD
907),
Oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone]
ESACURE ONE (Lamberti S.p.A., Gallarate, Italy),
2-hydroxy-2-methyl-1-phenyl propan-1-one (DAROCUR 1173), 2, 4,
6-trimethylbenzoyldiphenylphosphine oxide (OMNIRAD TPO), and 2, 4,
6-trimethylbenzoylphenyl phosphinate (OMNIRAD TPO-L). Additional
suitable photoinitiators include for example and without
limitation, benzyl dimethyl ketal, 2-methyl-2-hydroxypropiophenone,
benzoin methyl ether, benzoin isopropyl ether, anisoin methyl
ether, aromatic sulfonyl chlorides, photoactive oximes, and
combinations thereof.
[0072] In some embodiments, a photoinitiator is present in a
photopolymerizable composition in an amount of up to about 5% by
weight, based on the total weight of polymerizable components in
the photopolymerizable composition. In some cases, a photoinitiator
is present in an amount of 0.1 wt. % or more, 0.2 wt. % or more,
0.3 wt. % or more, 0.4 wt. % or more, 0.5 wt. % or more, 0.6 wt. %
or more, 0.7 wt. % or more, 0.8 wt. % or more, 0.9 wt. % or more,
1.0 wt. % or more, 1.25 wt. % or more, or 1.5 wt. % or more; and 5
wt. % or less, 4.8 wt. % or less, 4.6 wt. % or less, 4.4 wt. % or
less, 4.2 wt. % or less, 4.0 wt. % or less, 3.8 wt. % or less, 3.6
wt. % or less, 3.4 wt. % or less, 3.2 wt. % or less, 3.0 wt. % or
less, 2.8 wt. % or less, 2.6 wt. % or less, 2.4 wt. % or less, 2.2
wt. % or less, 2.0 wt. % or less, 1.8 wt. % or less, or 1.6 wt. %
or less. Stated another way, the photoinitiator may be present in
an amount of about 0.1-5% by weight, 0.2-5% by weight, or 0.5-5% by
weight, based on the total weight of the photopolymerizable
composition.
[0073] Further, a thermal initiator can optionally be present in a
photopolymerizable composition described herein. In some
embodiments, a thermal initiator is present in a photopolymerizable
composition or in an amount of up to about 5% by weight, based on
the total weight of polymerizable components in the
photopolymerizable composition. In some cases, a thermal initiator
is present in an amount of about 0.1-5% by weight, based on the
total weight of polymerizable components in the photopolymerizable
composition. Suitable thermal initiators include for instance and
without limitation, peroxides such as benzoyl peroxide, dibenzoyl
peroxide, dilauryl peroxide, cyclohexane peroxide, methyl ethyl
ketone peroxide, hydroperoxides, e.g., tert-butyl hydroperoxide and
cumene hydroperoxide, dicyclohexyl peroxydicarbonate,
2,2,-azo-bis(isobutyronitrile), and t-butyl perbenzoate. Examples
of commercially available thermal initiators include initiators
available from DuPont Specialty Chemical (Wilmington, Del.) under
the VAZO trade designation including VAZO 67
(2,2'-azo-bis(2-methybutyronitrile)) VAZO 64
(2,2'-azo-bis(isobutyronitrile)) and VAZO 52
(2,2'-azo-bis(2,2-dimethyvaleronitrile)), and LUCIDOL 70 from Elf
Atochem North America, Philadelphia, Pa.
[0074] In certain aspects, the use of more than one initiator
assists in increasing the percentage of monomer that gets
incorporated into the reaction product of polymerizable components
and thus decreasing the percentage of the monomer that remains
uncured.
Components
[0075] Orthodontic articles according to the present disclosure
comprise a polymerized reaction product of components. The
components include at least one isocyanate, at least one
(meth)acrylate mono-ol, at least one polycarbonate diol, and at
least one catalyst. Each of these components is discussed in detail
below.
[0076] Suitable amounts of each of the isocyanate, (meth)acrylate
mono-ol, and polycarbonate diol present in the components are based
on molar ratios of each of these components to the others. For
instance, a ratio of the isocyanate (e.g., a diisocyanate, which
has 2 isocyanate equivalents per mole of isocyanate compound) to
the polycarbonate diol typically ranges from 4 molar equivalents of
the isocyanate to 1 molar equivalent of the alcohol of the
polycarbonate diol, to 4 molar equivalents of the isocyanate to 3
molar equivalents of the alcohol of the polycarbonate diol. Stated
another way, a ratio of the isocyanate (e.g., a diisocyanate) to
the polycarbonate diol typically ranges from 4 molar equivalents of
the isocyanate to 1 molar equivalent of the alcohol of the
polycarbonate diol, to 1.3 molar equivalents of the isocyanate to 1
molar equivalent of the alcohol of the polycarbonate diol. In
select embodiments, a ratio of the isocyanate to the polycarbonate
diol is 4 molar equivalents of isocyanate to 2 molar equivalents of
the alcohol of the polycarbonate diol, or stated another way, 2
molar equivalents of isocyanate to 1 molar equivalent of alcohol of
the polycarbonate diol. The closer the ratio of the isocyanate to
the polycarbonate diol is to 1 molar equivalent of isocyanate to 1
molar equivalent of the alcohol of the polycarbonate diol, the
higher the weight average molecular weight of the resulting
polyurethane (meth)acrylate polymer produced in the polymerization
reaction product of components.
[0077] A ratio of the isocyanate (e.g., a diisocyanate) to the
(meth)acrylate mono-ol typically ranges from 4 molar equivalents of
the isocyanate to 3 molar equivalents of the (meth)acrylate
mono-ol, to 4 molar equivalents of the isocyanate to 1 molar
equivalent of the (meth)acrylate mono-ol. Stated another way, a
ratio of the isocyanate (e.g., a diisocyanate) to the
(meth)acrylate mono-ol typically ranges from 1.3 molar equivalents
of the isocyanate to 1 molar equivalent of the (meth)acrylate
mono-ol, to 4 molar equivalents of the isocyanate to 1 molar
equivalent of the (meth)acrylate mono-ol. In select embodiments, a
ratio of the isocyanate to the (meth)acrylate mono-ol is 4 molar
equivalents of the isocyanate to 2 molar equivalents of the
(meth)acrylate mono-ol, or stated another way, 2 molar equivalents
of the isocyanate to 1 molar equivalents of the (meth)acrylate
mono-ol.
[0078] A ratio of the polycarbonate diol to the (meth)acrylate
mono-ol typically ranges from 1 molar equivalent of the alcohol of
the polycarbonate diol to 3 molar equivalents of the (meth)acrylate
mono-ol, to 3 molar equivalents of the polycarbonate diol to 1
molar equivalents of the (meth)acrylate mono-ol. Stated another
way, a ratio of the polycarbonate diol to the (meth)acrylate
mono-ol typically ranges from 1 molar equivalent of the alcohol of
the polycarbonate diol to 3 molar equivalents of the (meth)acrylate
mono-ol, to 1 molar equivalent of the alcohol of the polycarbonate
diol to 0.3 molar equivalents of the (meth)acrylate mono-ol. In
select embodiments, a ratio of the polycarbonate diol to the
(meth)acrylate mono-ol is 1 molar equivalent of the alcohol of the
polycarbonate diol to 1 molar equivalent of the (meth)acrylate
mono-ol.
[0079] Isocyanate
[0080] The components (e.g., included in the polymerization
reaction product of components) comprise at least one isocyanate.
Polyisocyanates which can be employed in the components can be any
organic isocyanate having at least two free isocyanate groups.
Included are aliphatic, cycloaliphatic, aromatic and araliphatic
isocyanates. Any of the known polyisocyanates such as alkyl and
alkylene polyisocyanates, cycloalkyl and cycloalkylene
polyisocyanates, and combinations such as alkylene and
cycloalkylene polyisocyanates can be employed.
[0081] In some embodiments, diisocyanates having the formula
R.sub.di(NCO).sub.2 can be used, with R.sub.di as defined
above.
[0082] Specific examples of suitable diisocyanates include for
instance and without limitation, 2,6-toluene diisocyanate (TDI),
2,4-toluene diisocyanate,
methylenedicyclohexylene-4,4'-diisocyanate (H12MDI),
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),
1,6-diisocyanatohexane (HDI), tetramethyl-m-xylylene diisocyanate,
a mixture of 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexane
(TMXDI), trans-1,4-hydrogenated xylylene diisocyanates (H6XDI),
cyclohexyl-1,4-diisocyanate, 4,4'-methylene diphenyl diisocyanate,
2,4'-methylene diphenyl diisocyanate, a mixture of 4,4'-methylene
diphenyl diisocyanate and 2,4'-methylene diphenyl diisocyanate,
1,5-naphthalene diisocyanate, 1,4-tetramethylene diisocyanate,
1,4-phenylene diisocyanate, 2,6- and 2,4-toluene diisocyanate,
1,5-naphthylene diisocyanate, 2,4' and 4,4'-diphenylmethane
diisocyanate, pentamethylene diisocyanate, dodecamethylene
diisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane
diisocyanate, methyl 2,4-cyclohexane diisocyanate,
methyl-2,6-cyclohexane diisocyanate, 1,4-bis (isocyanatomethyl)
cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 4,4'-toluidine
diisocyanate, 4,4'-diphenyl ether diisocyanate, 1,3- or
1,4-xylylene diisocyanate, lysine diisocyanate methyl ester,
3,3'-dimethyl-4,4'-diphenylmethane diisocyanate,
3,3'-dimethyl-phenylene diisocyanate, 2,5-bis (isocyanate
methyl)-bicyclo[2.2.1]heptane, 2,6-bis (isocyanate
methyl)-bicyclo[2.2.1]heptane, bis (2-isocyanate ethyl) fumarate,
4-diphenylpropane diisocyanate,
trans-cyclohexane-1,4-diisocyanatehydrogenated dimer acid
diisocyanate, a norbornene diisocyanate, methylenebis
6-isopropyl-1,3-phenyl diisocyanate, and any combination thereof.
In select embodiments, the diisocyanate comprises IPDI.
[0083] It is also possible to use higher-functional polyisocyanates
known from polyurethane chemistry or else modified polyisocyanates,
for example containing carbodiimide groups, allophanate groups,
isocyanurate groups and/or biuret groups.
[0084] (Meth)acrylate mono-ol
[0085] The components (e.g., included in the polymerization
reaction product of components) comprise a (meth)acrylate mono-ol.
Typically, the (meth)acrylate mono-ol comprises a hydroxy
functional (meth)acrylate of Formula (II):
HO-Q-(A).sub.p (II)
wherein Q is a polyvalent organic linking group, A is a (meth)acryl
functional group of the formula
--XC(.dbd.O)C(R.sub.3).dbd.CH.sub.2, wherein X is O, S, or
NR.sub.4, R.sub.4 is H or alkyl of 1 to 4 carbon atoms, R.sub.3 is
a lower alkyl of 1 to 4 carbon atoms or H, and wherein p is 1 or
2.
[0086] Q can be a straight or branched chain or cycle-containing
connecting group. Q can include a covalent bond, an alkylene, an
arylene, an aralkylene, an alkarylene. Q can optionally include
heteroatoms such as O, N, and S, and combinations thereof. Q can
also optionally include a heteroatom-containing functional group
such as carbonyl or sulfonyl, and combinations thereof. In some
embodiments, Q is a straight chain, branched chain, or
cycle-containing connecting group selected from arylene,
aralkylene, and alkarylene. In yet other embodiments, Q is a
straight chain, branched chain, or cycle-containing connecting
group containing heteroatoms such as O, N, and S and/or a
heteroatom containing functional group such as carbonyl and
sulfonyl. In other embodiments, Q is a branched or cycle-containing
alkylene group that optionally contains heteroatoms selected from
O, N, S, and/or a heteroatom-containing functional group such as
carbonyl and sulfonyl.
[0087] In some embodiments, in the hydroxy functional
(meth)acrylate of Formula (II), Q is an alkylene group, p is 1, and
in the (meth)acryl functional group A, X is O and R.sub.2 is methyl
or H. In certain preferred embodiments, in the hydroxy functional
(meth)acrylate of Formula (II), Q is an alkylene group, p is 1, and
in the (meth)acryl functional group A, X is O and R.sub.2 is
methyl.
[0088] Suitable example (meth)acrylate mono-ols include for
instance and without limitation, 2-hydroxyethyl (meth)acrylate,
hydroxypropyl acrylate (all isomers), hydroxybutyl acrylate (all
isomers), poly(e-caprolactone) mono[2-(meth) acryloxy ethyl] esters
such as caprolactone monoacrylate available under the trade
designation "SR-495" from Sartomer USA (Arkema Group) (Exton, Pa.),
glycerol dimethacrylate, 1-(acryloxy)-3-(methacryloxy)-2-propanol,
2-hydroxy-3-phenyloxypropyl (meth)acrylate, 2-hydroxyalkyl
(meth)acryloyl phosphate, 4-hydroxycyclohexyl (meth)acrylate,
trimethylolpropane di(meth)acrylate, trimethylolethane
di(meth)acrylate, 1,4-butanediol mono(meth)acrylate, neopentyl
glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate,
3-chloro-2-hydroxypropyl (meth)acrylate,
2-hydroxy-3-alkyloxy(meth)acrylate, polyethylene glycol
mono(meth)acrylate, polypropylene glycol mono(meth)acrylate,
ethylene oxide-modified phthalic acid (meth)acrylate, and
4-hydroxycyclohexyl (meth)acrylate.
[0089] Polycarbonate diol
[0090] The components (e.g., included in the polymerization
reaction product of components) comprise a polycarbonate diol,
which was found to contribute to less water being absorbed during
contact with water than orthodontic articles containing
polyurethanes having alternate linking groups, such as polyethers.
As orthodontic articles are used in the moisture-rich environment
of a patient's mouth, the extent of water absorption is relevant to
the composition of an orthodontic article. Select articles absorb
less than 3%, less than 2.5%, less than 2%, less than 1.5%, or even
less than 1% water when soaked in deionized water for 7 days at
37.degree. C. The polycarbonate diol is of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I)
wherein each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit, and R.sub.2 are independently an aliphatic, cycloaliphatic,
or aliphatic/cycloaliphatic alkylene group and an average number of
carbon atoms in a combination of all the R.sub.1 and R.sub.2 groups
is 4 to 10, and m is (an integer of) 2 to 23. Stated another way,
while some repeat units of R.sub.1 and/or R.sub.2 may have a carbon
number of less than 4 (e.g., 2 or 3), enough of the repeat units
have a sufficiently high carbon number that when the carbon numbers
of all the repeat units of R.sub.1 and R.sub.2 in the polycarbonate
diol of Formula (I) are averaged, that average falls within the
range of 4 to 10, or any of 4 to 6, 4 to 7, 4 to 8, 4 to 9, 5 to 7,
5 to 8, 5 to 9, 5 to 10, 6 to 8, 6 to 9, 6 to 10, 7 to 9, 7 to 10,
or 8 to 10. In select embodiments, at least one of R.sub.1 or
R.sub.2 is --CH.sub.2CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2--,
--(CH.sub.2).sub.6--, or --(CH.sub.2).sub.4--, and preferably a
combination of --CH.sub.2CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2--,
and --(CH.sub.2).sub.6--.
[0091] In some embodiments, either the polycarbonate diol has a
number average molecular weight (Mn) of greater than 1,000 grams
per mole (g/mol) or a weighted average of all polycarbonate diols
present in the components has a Mn of greater than 1,000 g/mol,
wherein Mn is determined by OH value. Stated a different way, when
the components contain a single polycarbonate diol of Formula (I),
the polycarbonate diol has a Mn higher than 1,000 g/mol. When the
components contain two or more polycarbonate diols (e.g., one or
more being of Formula (I)), the Mn of at least one of the
polycarbonate diols may be 1,000 g/mol or less with the proviso
that a weighted average of all the Mn values of the two or more
polycarbonate diols is higher than 1,000 g/mol. For instance,
components containing two polycarbonate diols could include a molar
ratio of a first polycarbonate diol having a Mn of about 500 g/mol
of 1 to a second polycarbonate diol having a Mn of about 1,500
g/mol of 2, resulting in a weighted average Mn of 1,167 g/mol. In
certain embodiments, a polycarbonate diol (or a weighted average of
all the polycarbonate diols present in the components) has a number
average molecular weight of 1,500 g/mol or higher.
[0092] In some embodiments, one or more polycarbonate diols are
present having a Mn of 450 grams per mole (g/mol) or greater, 500
g/mol or greater, 550 g/mol or greater, 600 g/mol or greater, 650
g/mol or greater, 700 g/mol or greater, 750 g/mol or greater, 800
g/mol or greater, 850 g/mol or greater, 900 g/mol or greater, 950
g/mol or greater, or 1,000 g/mol or greater; and 3,200 g/mol or
less, 3,100 g/mol or less, 3,000 g/mol or less, 2,900 g/mol or
less, 2,800 g/mol or less, 2,700 g/mol or less, 2,600 g/mol or
less, 2,500 g/mol or less, 2,400 g/mol or less, 2,300 g/mol or
less, 2,200 g/mol or less, 2,100 g/mol or less, 2,000 g/mol or
less, 1,900 g/mol or less, 1,800 g/mol or less, or 1,700 g/mol or
less. Stated another way, the polycarbonate diol may have a Mn of
450 g/mol to 3,200 g/mol, 800 g/mol to 3,200 g/mol, 1,000 g/mol to
3,200 g/mol, 1,500 g/mol to 3,200 g/mol, 1,800 g/mol to 3,200
g/mol, 450 g/mol to 2,200 g/mol, 800 g/mol to 2,200 g/mol, 1,000
g/mol to 2,200 g/mol, 1,500 g/mol to 2,200 g/mol, or 1,800 g/mol to
2,200 g/mol. Inclusion of a polycarbonate diol having a Mn of
greater than 3,200 g/mol, on the other hand, may negatively impact
the stiffness of a photopolymerization reaction product of the
photopolymerization composition, by increasing the elastomeric
character of the photopolymerization reaction product. In select
embodiments, the photopolymerizable composition is essentially free
of any diols that have a Mn lower than the one or more
polycarbonate diols present in the components.
[0093] Suitable polycarbonate diols for use in the components
include for instance and without limitation, those commercially
available from Kuraray Co. Ltd. (Tokyo, JP) under the trade
designation "KURARAY POLYOL", e.g., specifically, each of the
KURARAY POLYOL C series: C-590, C-1090, C-2050, C-2090, and C-3090;
from Covestro LLC (Pittsburgh, Pa.) under the trade designation
"DESMOPHEN", e.g., specifically, each of the DESMOPHEN C series:
C-2100, C-2200, and C XP-2613.
[0094] Catalyst
[0095] The components (e.g., included in the polymerization
reaction product of components) comprise a catalyst to catalyze the
reaction of the at least one isocyanate, at least one
(meth)acrylate mono-ol, and at least one polycarbonate diol.
Typically, catalyst is included in an amount of 0.01 wt. % to 5 wt.
%, based on the total weight of the polymerizable components.
[0096] Examples of suitable catalysts include for instance and
without limitation, dioctyl dilaurate (DOTDL), stannous octoate,
dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide,
dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin
mercaptide, dioctyltin thiocarboxylate, lead 2-ethylhexanoate,
tetra-alkyl titanates such as tetrabutyl titanate (TBT),
triethylamine, N, N-dimethylcyclohexylamine, N-methylmorpholine,
N-ethylmorpholine, N, N-dimethyl-p-toluidine, beta-(dimethylamino)
propionitrile, N-methylpyrrolidone, N, N-dicyclohexylmethylamine,
dimethylaminoethanol, dimethylamino-ethoxyethanol,
triethylenediamine, N, N, N'-trimethyl aminoethyl ethanol amine, N,
N, N', N'-tetramethylethylenediamine, N, N, N',
N'-tetramethyl-1,3-diamine, N, N, N',
N'-tetramethyl-1,6-hexanediol-diamine, bis(N, N-dimethylaminoethyl)
ether, N'-cyclohexyl-N, N-dimethyl-formamidine, N,
N'-dimethylpiperazine, trimethyl piperazine, bis(aminopropyl)
piperazine, N--(N, N'-dimethylaminoethyl) morpholine,
bis(morpholinoethyl) ether, 1,2-dimethyl imidazole,
N-methylimidazole, 1,4-diamidines, diazabicyclo-[2.2.2]-octane
(DABCO), 1,4-diazabicyclo [3.3.0]-oct-4-ene (DBN),
1,8-diazabicyclo-[4.3.0]-non-5-ene (DBN),
1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU), and phenol salts, salts
such as octyl acid salts, N, N, N',
N''-pentamethyldiethylenetriamine, N, N, N', N''-pentamethyl
dipropylenetriamine, tetramethylguanidine, N-cyclohexyl-N', N',
N'', N''-tetramethyl guanidine, N-methyl-N'-(2-dimethyl amino
ethyl) piperazine, 1,3,5-tris (N,
N-dimethyl-propyl)-hexahydro-1,3,5-triazine.
[0097] In any embodiment, the catalyst comprises zinc, an amine,
tin, zirconium, or bismuth. The catalyst can comprise tin, such as
dibutyltin diacrylate. Preferably, however, the catalyst is free of
tin, as tin catalysts may not be desirable to include in
orthodontic articles that will be in contact with a patient's
mouth.
[0098] The catalyst may comprise an organometallic zinc complex
that is free of 2-ethylhexyl carboxylate and 2-ethylhexanoic acid,
such as the zinc catalyst commercially available from King
Industries, Inc. (Norwalk, Conn.) under the trade designation K-KAT
XK-672, and/or other zinc catalysts available from King Industries,
such as K-KAT XK-661, and K-KAT XK-635. Another suitable catalyst
is bismuth neodecanoate, for instance commercially available from
Sigma-Aldrich (St. Louis, Mo.), as well as bismuth catalysts
available from King Industries under the trade designations K-KAT
XK-651 and K-KAT 348. Available aluminum based catalysts include
K-KAT 5218 from King Industries. Further, zirconium based catalysts
include K-KAT 4205 and K-KAT 6212 available from King
Industries.
Polymerized Reaction Product of Components
[0099] Orthodontic articles according to the present disclosure
comprise a polymerized reaction product of components, which were
described above. The polymerized reaction product of components
contains at least one polyurethane (meth)acrylate polymer.
Urethanes are prepared by the reaction of an isocyanate with an
alcohol to form carbamate linkages. The polyurethane (meth)acrylate
polymer typically provides toughness (e.g., at least a minimum
tensile strength and/or modulus and flexibility, (e.g., at least a
minimum elongation at break)) to the final orthodontic article. In
addition to the urethane functionality, the polyurethane
(meth)acrylate polymer further comprises a polycarbonate linking
group. The linking group is a functional group that connects two or
more urethane groups, and may be divalent, trivalent, or
tetravalent, and preferably divalent. In addition, the polyurethane
(meth)acrylate polymer optionally further comprises one or more
functional groups selected from hydroxyl groups, carboxyl groups,
amino groups, and siloxane groups. These functional groups can be
reactive with other components of the photopolymerizable
composition during polymerization. The polyurethane (meth)acrylate
polymer preferably has a weight average molecular weight (Mw) of
3,000 g/mol or greater, 4,000 g/mol or greater, 5,000 g/mol or
greater, 6,000 g/mol or greater, 6,000 g/mol or greater, 7,000
g/mol or greater, 8,000 g/mol or greater, 9,000 g/mol or greater,
10,000 g/mol or greater, 11,000 g/mol or greater, or 12,000 g/mol
or greater; and 50,000 g/mol or less, 45,000 g/mol or less, 40,000
g/mol or less, 35,000 g/mol or less, 32,000 g/mol or less, 30,000
g/mol or less, 28,000 g/mol or less, 25,000 g/mol or less, 23,000
g/mol or less, 20,000 g/mol or less, or 18,000 g/mol or less.
Stated another way, the polyurethane (meth)acrylate polymer may
have a Mw of 3,000 g/mol to 50,000 g/mol, 6,000 g/mol to 40,000
g/mol, 6,000 g/mol to 18,000 g/mol, 6,000 g/mol to 35,000 g/mol, or
8,000 g/mol to 32,000 g/mol. Weight average molecular weight may be
measured using gel permeation chromatography (GPC), for instance
using the method described in the Examples below. Higher molecular
weight of the polyurethane (meth)acrylates will result in higher
viscosity resin formulations with comparable compositions and
loadings, which makes them less flowable; lower molecular weight of
the polyurethane (meth)acrylates will reduce their toughening
effect on the cured orthodontic articles.
[0100] In some embodiments, the polyurethane (meth)acrylate is of
Formula (VI):
(A).sub.p-Q-OC(O)NH--R.sub.di--NH--C(O)--[O--R.sub.dOH--OC(O)NH--R.sub.d-
h--NH--C(O)].sub.r--O-Q-(A).sub.p (VI)
wherein, A has the formula --OC(.dbd.O)C(R.sub.3).dbd.CH.sub.2
wherein R.sub.3 is an alkyl of 1 to 4 carbon atoms (e.g. methyl) or
H, p is 1 or 2, Q is a polyvalent organic linking group as
described above, Rai is the residue of a diisocyanate, R.sub.dOH is
the residue of a polycarbonate polyol, and r averages from 1 to 15.
In some embodiments, r is no greater than 15, 14, 13, 12, 11, or
10. In some embodiments, r averages at least 2, 3, 4, or 5. In some
embodiments, A is a methacryl functional group, such as
methacrylate.
[0101] In some embodiments, the polymerized reaction product of
components further comprises one or more side reaction products in
addition to the polyurethane (meth)acrylate polymer. Depending on
the selectivity of the catalyst and/or the weight ratios of the
components, oligomers of the reactants may be produced. The order
of addition of components in preparing the photopolymerizable
composition affects the relative amounts of polymers and oligomers
produced in the photopolymerized reaction product. For instance,
adding the isocyanate to the polycarbonate diol first, followed by
adding the monofunctional (meth)acrylate results in a higher ratio
of polyurethane (meth)acrylate polymer to side products such as
oligomers, than instead adding the monofunctional (meth)acrylate to
the isocyanate first, followed by adding the polycarbonate
diol.
[0102] Oligomers having a structure of monofunctional
(meth)acrylate monomer-isocyanate-monofunctional (meth)acrylate
monomer have been found to be a byproduct of the polymerization
reaction of components in certain embodiments. It is possible to
purify the polyurethane (meth)acrylate polymer to remove such side
products. Alternatively, additional side products such as oligomers
may be added to the polymerized reaction product, particularly when
a specific reaction generates a small amount of one or more side
products. It has been discovered that some side product components
can improve at least one of modulus or extent of crosslinking after
the photopolymerizable composition has been cured.
[0103] For example, photopolymerizable compositions optionally
comprise a compound of Formula (III):
(H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--X).sub.p-Q-OC(.dbd.O)NH--R.sub.di-NHC-
(.dbd.O)O-Q-(X--C(.dbd.O)(R.sub.3)C.dbd.CH.sub.2).sub.p (III)
[0104] wherein X, Q, p, and R.sub.3 are as defined for Formula
(II), and Rai is the residue of a diisocyanate as defined above.
Typically, the compound of Formula (III) is produced during the
polymerization of the components, as described above. The specific
formulation of the components will affect how much of a compound of
Formula (III) is made during the polymerization of components. For
instance, the specificity of the catalyst towards catalyzing the
formation of the polyurethane (meth)acrylate polymer can affect the
amount of the compound of Formula (III) generated during the
polymerization of the components. In certain embodiments, the
compound of Formula (III) is added to the photopolymerizable
composition, particularly when a smaller amount of the compound of
Formula (III) is produced by the polymerization of components than
desired. In any embodiment, the compound may advantageously improve
crosslinking during the photopolymerization reaction, increase the
modulus or the photopolymerization reaction product, or both.
Regardless of if the compound of Formula (III) is formed during the
polymerization of the components, added separately to the
photopolymerizable composition, or both, in some embodiments the
compound of Formula (III) is present in an amount of 0.05 weight
percent (wt. %) or greater, based on the weight of the
polymerizable composition, 0.1 wt. % or greater, 0.5 wt. % or
greater, 1 wt. % or greater, 1.5 wt. % or greater, 2.5 wt. % or
greater, 2 wt. % or greater, 3 wt. % or greater, 4 wt. % or
greater, 5 wt. % or greater, 6 wt. % or greater, 7 wt. % or
greater, 8 wt. % or greater, or 9 wt. % or greater; and 20 wt. % or
less, 18 wt. % or less, 16 wt. % or less, 15 wt. % or less, 14 wt.
% or less, 12 wt. % or less, or 10 wt. % or less, based on the
weight of the polymerizable composition. Stated another way, the
compound of Formula (III) may be present in the photopolymerizable
composition in an amount of 0.05 to 20 weight percent (wt. %), 1.5
to 12 wt. %, 2.5 to 12 wt. %, 5 to 15 wt. %, 5 to 12 wt. %, 7 to 15
wt. %, 7 to 12 wt. %, or 5 to 20 wt. %, based on the weight of the
polymerizable composition. Optionally, X is O in the compound of
Formula (III). In select embodiments, the compound of Formula (III)
is of Formula (IV):
##STR00002##
Second Polymerization Reaction Product of Components:
[0105] In any embodiment, the photopolymerizable composition
further comprises a second polymerization reaction product of
components. The use of a second polyurethane(meth)acrylate polymer
may provide somewhat different mechanical properties to the
orthodontic article than using a single polyurethane(meth)acrylate
polymer in the photopolymerizable composition. The components of
the second polymerization reaction product comprise: [0106] 1) an
isocyanate functional (meth)acrylate compound of the Formula
(VII):
[0106] (A).sub.p-Q-NCO (VII), [0107] wherein A, p, and Q are as
defined for Formula (II); [0108] 2) a polycarbonate diol of Formula
(I):
[0108] H(O--R.sub.1--O--C(.dbd.O)).sub.mO--R.sub.2--OH (I) [0109]
wherein each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23; and [0110] 3) a
catalyst. The second polymerization reaction product comprises a
polyurethane (meth)acrylate polymer that is different from the
first polyurethane (meth)acrylate polymer. In select embodiments,
the second polymerization reaction product comprises a compound of
Formula (VIII):
[0110]
(H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--O).sub.p-Q-NH--C(.dbd.O)--(O---
R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--O--C(.dbd.O)NH-Q-(O--C(.dbd.O)(R-
.sub.3)C.dbd.CH.sub.2).sub.p (VIII);
wherein Q, p, and R.sub.3 are as defined for Formula (II) and
R.sub.1 and R.sub.2 are as defined for Formula (I).
[0111] The compound of Formula (VIII) is typically obtained by
reaction of a polycarbonate diol with an isocyanate functional
(meth)acrylate compound in the presence of a catalyst. Examples of
the isocyanate functional (meth)acrylate include isocyanatoethyl
methacrylate, isocyanatoethoxyethyl methacrylate, isocyanatoethyl
acrylate, and 1,1-(bisacryloyloxymethyl) ethyl isocyanate, which
are for instance commercially available from Showa Denko (Tokyo,
Japan). As an example, the compound of Formula (VIII) may, in
select embodiments, be a compound of Formula (IX):
##STR00003##
In Formula (IX), n is about 6.7 for a 1000 molecular weight
polycarbonate diol based on hexane diol.
[0112] In some embodiments, the second polymerization reaction
product comprises a compound of Formula (XII):
##STR00004##
[0113] wherein R.sub.d, is a residue of a diisocyanate as defined
above. In embodiments in which the diisocyanate is asymmetric,
during polymerization the orientation of attachment of the residue
of the diisocyanate to the nitrogen atoms of the carbamate linkages
will vary and the polymerized reaction product will accordingly
contain multiple polyurethane methacrylate structures.
Difunctional Component
[0114] The photopolymerizable compositions of the present
disclosure optionally include at least one difunctional component,
such as a difunctional (meth)acrylate monomer or oligomer. A
difunctional component present in a photopolymerizable composition
can co-react with the polyurethane (meth)acrylate polymer (e.g., is
capable of undergoing addition polymerization).
[0115] A difunctional component (e.g., monomer) is optionally
present in an amount of up to 15 wt. %, based on the total weight
of the photopolymerizable composition, up to 12 wt. %, up to 10 wt.
%, or up to 8 wt. %, based on the total weight of the
photopolymerizable composition. Including more than 15 wt. %
difunctional components may lead to more crosslinking than desired
and decrease the elongation of the orthodontic article.
[0116] Suitable difunctional monomers include for instance and
without limitation, compounds having the Formula (X):
H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)X-Q-O--C(.dbd.O)NH--R.sub.di--NHC(.dbd.O-
)--O-Q-XC(.dbd.O)C(R.sub.3).dbd.CH.sub.2 (X);
[0117] wherein R.sub.3 is as defined for Formula (II) and R.sub.d,
is the residue of a diisocyanate, or compounds having the Formula
(XI):
H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--O-Q-NH--C(.dbd.O)--(O--R.sub.1--O--C(.-
dbd.O)).sub.m--O--R.sub.2--O--C(.dbd.O)NH-Q-O--C(.dbd.O)C(R.sub.3).dbd.CH.-
sub.2 (XI),
wherein Q, X, and R.sub.3 are as defined for Formula (II) and
R.sub.1 and R.sub.2 are as defined for Formula (I). Additional
suitable difunctional monomers include hydroxyethyl methacrylate
diester of terephthalic acid, 1,12-dodecanediol dimethacrylate,
alkoxylated hexanediol diacrylate, alkoxylated neopentyl glycol
diacrylate, caprolactone modified neopentylglycol hydroxypivalate
diacrylate, caprolactone modified neopentylglycol hydroxypivalate
diacrylate, cyclohexanedimethanol diacrylate, diethylene glycol
diacrylate, dipropylene glycol diacrylate, ethoxylated (10)
bisphenol A diacrylate, ethoxylated (3) bisphenol A diacrylate,
ethoxylated (30) bisphenol A diacrylate, ethoxylated (4) bisphenol
A diacrylate, hydroxypivalaldehyde modified trimethylolpropane
diacrylate, neopentyl glycol diacrylate, polyethylene glycol (200)
diacrylate, polyethylene glycol (400) diacrylate, polyethylene
glycol (600) diacrylate, propoxylated neopentyl glycol diacrylate,
tetraethylene glycol diacrylate, tricyclodecanedimethanol
diacrylate, triethylene glycol diacrylate, tripropylene glycol
diacrylate, or any combination thereof. Further suitable
difunctional monomers include the dimethacrylates of each of the
above listed diacrylates.
[0118] Typically, the photopolymerizable compositions are
essentially free of trihydric alcohols, which are alcohols having
three hydroxyl groups. This is due to such alcohols increasing the
hydrophilicity of the photopolymerizable composition, which may
result in an undesirably high water absorption during use of an
orthodontic article prepared from the photopolymerizable
composition.
[0119] Additives
[0120] Photopolymerizable compositions described herein, in some
instances, further comprise one or more additives, such as one or
more additives selected from the group consisting of inhibitors,
stabilizing agents, sensitizers, absorption modifiers, fillers and
combinations thereof.
[0121] In addition, a photopolymerizable material composition
described herein can further comprise one or more sensitizers to
increase the effectiveness of one or more photoinitiators that may
also be present. In some embodiments, a sensitizer comprises
isopropylthioxanthone (ITX) or 2-chlorothioxanthone (CTX). Other
sensitizers may also be used. If used in the photopolymerizable
composition, a sensitizer can be present in an amount ranging of
about 0.01% by weight or about 1% by weight, based on the total
weight of the photopolymerizable composition.
[0122] A photopolymerizable composition described herein optionally
also comprises one or more polymerization inhibitors or stabilizing
agents. A polymerization inhibitor is often included in a
photopolymerizable composition to provide additional thermal
stability to the composition. A stabilizing agent, in some
instances, comprises one or more anti-oxidants. Any anti-oxidant
not inconsistent with the objectives of the present disclosure may
be used. In some embodiments, for example, suitable anti-oxidants
include various aryl compounds, including butylated hydroxytoluene
(BHT), which can also be used as a polymerization inhibitor in
embodiments described herein. In addition to or as an alternative,
a polymerization inhibitor comprises methoxyhydroquinone
(MEHQ).
[0123] In some embodiments, a polymerization inhibitor, if used, is
present in an amount of about 0.001-2% by weight, 0.001 to 1% by
weight, or 0.01-1% by weight, based on the total weight of the
photopolymerizable composition. Further, if used, a stabilizing
agent is present in a photopolymerizable composition described
herein in an amount of about 0.1-5% by weight, about 0.5-4% by
weight, or about 1-3% by weight, based on the total weight of the
photopolymerizable composition.
[0124] A photopolymerizable composition as described herein can
also comprise one or more UV absorbers including dyes, optical
brighteners, pigments, particulate fillers, etc., to control the
penetration depth of actinic radiation. One particularly suitable
UV absorber is Tinuvin 326
(2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol,
obtained from BASF Corporation, Florham Park, N.J. Another
particularly suitable UV absorber that is an optical brightener
that is Tinopal OB, a benzoxazole,
2,2'-(2,5-thiophenediyl)bis[5-(1,1-dimethylethyl)], also available
from BASF Corporation. Another suitable UV absorber is an optical
brightener comprising a compound of Formula (V):
##STR00005##
[0125] The compound of Formula V may be synthesized as described in
detail in the Examples below.
[0126] The UV absorber, if used, can be present in an amount of
about 0.001-5% by weight, about 0.01-1% by weight, about 0.1-3% by
weight, or about 0.1-1% by weight, based on the total weight of the
photopolymerizable composition.
[0127] Photopolymerizable compositions may include fillers,
including nano-scale fillers. Examples of suitable fillers are
naturally occurring or synthetic materials including, but not
limited to: silica (SiO.sub.2 (e.g., quartz)); alumina
(Al.sub.2O.sub.3), zirconia, nitrides (e.g., silicon nitride);
glasses and fillers derived from, for example, Zr, Sr, Ce, Sb, Sn,
Ba, Zn, and Al; feldspar; borosilicate glass; kaolin (china clay);
talc; zirconia; titania; and submicron silica particles (e.g.,
pyrogenic silicas such as those available under the trade
designations AEROSIL, including "OX 50," "130," "150" and "200"
silicas from Degussa Corp., Akron, Ohio and CAB-O-SIL M5 and TS-720
silica from Cabot Corp., Tuscola, Ill.). Organic fillers made from
polymeric materials are also possible, such as those disclosed in
International Publication No. WO09/045752 (Kalgutkar et al.).
[0128] The compositions may further contain fibrous reinforcement
and colorants such as dyes, pigments, and pigment dyes. Examples of
suitable fibrous reinforcement include PGA microfibrils, collagen
microfibrils, and others as described in U.S. Pat. No. 6,183,593
(Narang et al.). Examples of suitable colorants as described in
U.S. Pat. No. 5,981,621 (Clark et al.) include 1-hydroxy-4-[4-me
thylphenylamino]-9,10-anthracenedione (FD&C violet No. 2);
disodium salt of
6-hydroxy-5-[(4-sulfophenyl)oxo]-2-naphthalenesulfonic acid
(FD&C Yellow No. 6);
9-(o-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3H-xanthen-3-one,
disodium salt, monohydrate (FD&C Red No. 3); and the like.
[0129] Discontinuous fibers are also suitable fillers, such as
fibers comprising carbon, ceramic, glass, or combinations thereof.
Suitable discontinuous fibers can have a variety of compositions,
such as ceramic fibers. The ceramic fibers can be produced in
continuous lengths, which are chopped or sheared to provide the
discontinuous ceramic fibers. The ceramic fibers can be produced
from a variety of commercially available ceramic filaments.
Examples of filaments useful in forming the ceramic fibers include
the ceramic oxide fibers sold under the trademark NEXTEL (3M
Company, St. Paul, Minn.). NEXTEL is a continuous filament ceramic
oxide fiber having low elongation and shrinkage at operating
temperatures, and offers good chemical resistance, low thermal
conductivity, thermal shock resistance, and low porosity. Specific
examples of NEXTEL fibers include NEXTEL 312, NEXTEL 440, NEXTEL
550, NEXTEL 610 and NEXTEL 720. NEXTEL 312 and NEXTEL 440 are
refractory aluminoborosilicate that includes Al.sub.2O.sub.3,
SiO.sub.2 and B.sub.2O.sub.3. NEXTEL 550 and NEXTEL 720 are
aluminosilica and NEXTEL 610 is alumina. During manufacture, the
NEXTEL filaments are coated with organic sizings or finishes which
serves as aids in textile processing. Sizing can include the use of
starch, oil, wax or other organic ingredients applied to the
filament strand to protect and aid handling. The sizing can be
removed from the ceramic filaments by heat cleaning the filaments
or ceramic fibers as a temperature of 700.degree. C. for one to
four hours.
[0130] The ceramic fibers can be cut, milled, or chopped so as to
provide relatively uniform lengths, which can be accomplished by
cutting continuous filaments of the ceramic material in a
mechanical shearing operation or laser cutting operation, among
other cutting operations. Given the highly controlled nature of
certain cutting operations, the size distribution of the ceramic
fibers is very narrow and allow to control the composite property.
The length of the ceramic fiber can be determined, for instance,
using an optical microscope (Olympus MX61, Tokyo, Japan) fit with a
CCD Camera (Olympus DP72, Tokyo, Japan) and analytic software
(Olympus Stream Essentials, Tokyo, Japan). Samples may be prepared
by spreading representative samplings of the ceramic fiber on a
glass slide and measuring the lengths of at least 200 ceramic
fibers at 10.times. magnification.
[0131] Suitable fibers include for instance ceramic fibers
available under the trade name NEXTEL (available from 3M Company,
St. Paul, Minn.), such as NEXTEL 312, 440, 610 and 720. One
presently preferred ceramic fiber comprises polycrystalline
.alpha.-Al.sub.2O.sub.3. Suitable alumina fibers are described, for
example, in U.S. Pat. No. 4,954,462 (Wood et al.) and U.S. Pat. No.
5,185,299 (Wood et al.). Exemplary alpha alumina fibers are
marketed under the trade designation NEXTEL 610 (3M Company, St.
Paul, Minn.). In some embodiments, the alumina fibers are
polycrystalline alpha alumina fibers and comprise, on a theoretical
oxide basis, greater than 99 percent by weight Al.sub.2O.sub.3 and
0.2-0.5 percent by weight SiO.sub.2, based on the total weight of
the alumina fibers. In other embodiments, some desirable
polycrystalline, alpha alumina fibers comprise alpha alumina having
an average grain size of less than one micrometer (or even, in some
embodiments, less than 0.5 micrometer). In some embodiments,
polycrystalline, alpha alumina fibers have an average tensile
strength of at least 1.6 GPa (in some embodiments, at least 2.1
GPa, or even, at least 2.8 GPa). Suitable aluminosilicate fibers
are described, for example, in U.S. Pat. No. 4,047,965 (Karst et
al). Exemplary aluminosilicate fibers are marketed under the trade
designations NEXTEL 440, and NEXTEL 720, by 3M Company (St. Paul,
Minn.). Aluminoborosilicate fibers are described, for example, in
U.S. Pat. No. 3,795,524 (Sowman). Exemplary aluminoborosilicate
fibers are marketed under the trade designation NEXTEL 312 by 3M
Company. Boron nitride fibers can be made, for example, as
described in U.S. Pat. No. 3,429,722 (Economy) and U.S. Pat. No.
5,780,154 (Okano et al.).
[0132] Ceramic fibers can also be formed from other suitable
ceramic oxide filaments. Examples of such ceramic oxide filaments
include those available from Central Glass Fiber Co., Ltd. (e.g.,
EFH75-01, EFH150-31). Also preferred are aluminoborosilicate glass
fibers, which contain less than about 2% alkali or are
substantially free of alkali (i.e., "E-glass" fibers). E-glass
fibers are available from numerous commercial suppliers.
[0133] Examples of useful pigments include, without limitation:
white pigments, such as titanium oxide, zinc phosphate, zinc
sulfide, zinc oxide and lithopone; red and red-orange pigments,
such as iron oxide (maroon, red, light red), iron/chrome oxide,
cadmium sulfoselenide and cadmium mercury (maroon, red, orange);
ultramarine (blue, pink and violet), chrome-tin (pink) manganese
(violet), cobalt (violet); orange, yellow and buff pigments such as
barium titanate, cadmium sulfide (yellow), chrome (orange, yellow),
molybdate (orange), zinc chromate (yellow), nickel titanate
(yellow), iron oxide (yellow), nickel tungsten titanium, zinc
ferrite and chrome titanate; brown pigments such as iron oxide
(buff, brown), manganese/antimony/titanium oxide, manganese
titanate, natural siennas (umbers), titanium tungsten manganese;
blue-green pigments, such as chrome aluminate (blue), chrome
cobalt-alumina (turquoise), iron blue (blue), manganese (blue),
chrome and chrome oxide (green) and titanium green; as well as
black pigments, such as iron oxide black and carbon black.
Combinations of pigments are generally used to achieve the desired
color tone in the cured composition.
[0134] The use of florescent dyes and pigments can also be
beneficial in enabling the printed composition to be viewed under
black-light. A particularly useful hydrocarbon soluble fluorescing
dye is 2,5-bis(5-tert-butyl-2-benzoxazolyl) 1 thiophene.
Fluorescing dyes, such as rhodamine, may also be bound to cationic
polymers and incorporated as part of the resin.
[0135] If desired, the compositions of the disclosure may contain
other additives such as indicators, accelerators, surfactants,
wetting agents, antioxidants, tartaric acid, chelating agents,
buffering agents, and other similar ingredients that will be
apparent to those skilled in the art. Additionally, medicaments or
other therapeutic substances can be optionally added to the
photopolymerizable compositions. Examples include, but are not
limited to, fluoride sources, whitening agents, anticaries agents
(e.g., xylitol), remineralizing agents (e.g., calcium phosphate
compounds and other calcium sources and phosphate sources),
enzymes, breath fresheners, anesthetics, clotting agents, acid
neutralizers, chemotherapeutic agents, immune response modifiers,
thixotropes, polyols, anti-inflammatory agents, antimicrobial
agents, antifungal agents, agents for treating xerostomia,
desensitizers, and the like, of the type often used in dental
compositions.
[0136] Combinations of any of the above additives may also be
employed. The selection and amount of any one such additive can be
selected by one of skill in the art to accomplish the desired
result without undue experimentation.
[0137] Photopolymerizable compositions materials herein can also
exhibit a variety of desirable properties, non-cured, cured, and as
post-cured articles. A photopolymerizable composition, when
non-cured, has a viscosity profile consistent with the requirements
and parameters of one or more additive manufacturing devices (e.g.,
3D printing systems). Advantageously, in many embodiments the
photopolymerizable composition contains a minimal amount of
solvent. For instance, the composition may comprise 95% to 100%
solids, preferably 100% solids. In some instances, a
photopolymerizable composition described herein when non-cured
exhibits a dynamic viscosity of about 0.1-1,000 Pas, about 0.1-100
Pas, or about 1-10 Pas using a TA Instruments AR-G2 magnetic
bearing rheometer using a 40 mm cone and plate measuring system at
40 degrees Celsius and at a shear rate of 0.11/s. In some cases, a
photopolymerizable composition described herein when non-cured
exhibits a dynamic viscosity of less than about 10 Pas.
Orthodontic Articles
[0138] A polymerized reaction product of a photopolymerizable
composition according to the above disclosure comprises a shape of
an orthodontic article. The conformability and durability of a
cured orthodontic article made from the photopolymerizable
compositions of the present disclosure can be determined in part by
standard tensile, modulus, and/or elongation testing. The
photopolymerizable compositions can typically be characterized by
at least one of the following parameters after hardening.
[0139] The orthodontic article preferably exhibits at least one
desirable physical property. These physical properties include the
following: initial relaxation modulus, elongation at break, tensile
strength, relaxation modulus at 30 minutes, percent loss of
relaxation modulus, weight percent extractable components, and
exhibiting peaks in loss modulus and tan delta with large
temperature separation, and percent weight of water absorption.
Preferably, the orthodontic article exhibits at least two different
desirable physical properties, more preferably at least three
different desirable physical properties, and most preferably at
least initial relaxation modulus, elongation at break, and tensile
strength. The values of these different physical properties are
described below.
[0140] An orthodontic article optionally exhibits an initial
relaxation modulus of 100 megapascals (MPa) or greater measured at
37.degree. C. and 2% strain, as determined by Dynamic Mechanical
Analysis (DMA) following conditioning (i.e., soaking) of a sample
of the material of the orthodontic article in deionized water for
48 hours at room temperature (i.e., 22 to 25.degree. C.) ("Water
Conditioning"). The DMA procedure is described in detail in the
Examples below. Preferably, an orthodontic article exhibits an
initial relaxation modulus of 200 MPa or greater, 300 MPa or
greater, 400 MPa or greater, 500 MPa or greater, 600 MPa or
greater, 700 MPa or greater, 800 MPa or greater, 900 MPa or
greater, 1,000 MPa or greater, 1,100 MPa or greater, or even 1,200
MPa or greater. In some embodiments, the initial relaxation modulus
is no greater than about 3000, 2500, 2000, or 1500 MPa.
[0141] An orthodontic article optionally exhibits a (e.g., 30
minute) relaxation modulus of 100 MPa or greater as determined by
DMA following 30 minutes of soaking in water at 37.degree. C. under
a 2% strain. The DMA procedure for relaxation modulus is described
in detail in the Examples below, and is performed on a sample of
the material of the orthodontic article following Water
Conditioning and initial relaxation modulus testing. Preferably, an
orthodontic article exhibits a (e.g., 30 minute) relaxation modulus
of 200 MPa or greater, 300 MPa or greater, 400 MPa or greater, 500
MPa or greater, 600 MPa or greater, 700 MPa or greater, 800 MPa or
greater, 900 MPa or greater, or even 1,000 MPa or greater. In some
embodiments, the (e.g., 30 minute) relaxation modulus is no greater
than about 1500, 1200, 1000, or 800 MPa.
[0142] An orthodontic article optionally exhibits a percent loss of
relaxation modulus of 70% or less as determined by DMA. The loss is
determined by comparing the initial relaxation modulus to the
(e.g., 30 minute) relaxation modulus at 37.degree. C. and 2%
strain. It was discovered that orthodontic articles according to at
least certain embodiments of the present disclosure exhibit a
smaller loss in relaxation modulus following exposure to water than
articles made of different materials. Preferably, an orthodontic
article exhibits loss of relaxation modulus of 65% or less, 60% or
less, 55% or less, 50% or less, 45% or less 40% or less, or even
35% or less. In some embodiments, the loss of relaxation modulus is
10%, 15%, or 20% or greater.
[0143] An orthodontic article optionally exhibits an elongation at
break of a printed article of 20% or greater, as determined
according to the Examples section below, after conditioning (i.e.,
soaking) of a sample of the material of the orthodontic article in
phosphate-buffered saline having a pH of 7.4, for 24 hours at a
temperature of 37.degree. C. ("PBS Conditioning"). High elongation
at break helps prevent the orthodontic article from being too
brittle and potentially breaking during use by a patient.
Preferably, an orthodontic article exhibits an elongation at break
of 25% or greater, 30% or greater, 35% or greater, 40% or greater,
45% or greater, 50% or greater, 55% or greater, 60% or greater, 65%
or greater, 70% or greater, 75% or greater, 80% or greater, 85% or
greater, 90% or greater, 95% or greater, 100% or greater, 110% or
greater, or even 120% or greater. In some embodiments, the
elongation at break is no greater than 250%, 240%, 230%, 220%,
210%, 200%, 190%, 180%, 170%, 160%, 150%, or 140%.
[0144] An orthodontic article optionally exhibits a tensile
strength at yield (or maximum) of 14 MPa or greater as determined
according to ASTM-D638-14, using test specimen V, after PBS
Conditioning. Strength at yield (i.e., yield strength) is defined
as the maximum tensile stress a material can handle before it is
permanently deformed. Tensile strength at break refers to the point
on the stress-strain curve where the material breaks. As used
herein, samples that yield have a distinct peak in the
stress-strain curve. The stress-strain curves for brittle
materials, however, do not have a yield point and are often linear
over the full range of strain, eventually terminating in fracture
at a maximum tensile strength without appreciable plastic flow.
High tensile strength contributes to the orthodontic article having
sufficient strength to be resilient during use in a patient's
mouth. Preferably, an orthodontic article exhibits a tensile
strength of 15 MPa or greater, 17 MPa or greater, 20 MPa or
greater, 25 MPa or greater, 30 MPa or greater, 35 MPa or greater,
40 MPa or greater, 45 MPa or greater, 50 MPa or greater, or even 55
MPa or greater. In some embodiments, the tensile strength is no
greater than 100 MPa, 95 MPa, 90 MPa, 85 MPa, 80 MPa, 75 MPa, or 70
MPa.
[0145] In select embodiments, an orthodontic article exhibits an
initial relaxation modulus of 100 MPa, an elongation at break of
20% or greater, and a tensile strength of 14 MPa or greater.
Similarly, an article may exhibit any combination of the preferred
values described above, of each of the initial relaxation modulus,
elongation at break, and tensile strength at yield. It was
unexpectedly found that photopolymerizable compositions according
to at least certain embodiments are capable of forming articles
simultaneously having all three of these physical properties.
[0146] In select embodiments, dynamic mechanical analysis of
articles showed a specific type of response that gave high
elongation with high relaxation modulus at 30 minutes. When
measured at a frequency of 1 Hz and a temperature heating ramp rate
of 2.degree. C./min from below -40.degree. C. to above 200.degree.
C., some embodiments according to the present disclosure display a
peak in the loss modulus below 20.degree. C., more preferably below
15.degree. C., most preferably below 10.degree. C. In some
embodiments, the peak loss modulus temperature is at least
-70.degree. C., -60.degree. C., or -50.degree. C. The term peak
does not necessarily mean the global maximum value in loss modulus,
but can be a local maximum value, or a shoulder on a larger peak.
These articles tend to display high levels of elongation at break.
In other embodiments, articles may display a tan delta peak
>60.degree. C., >80.degree. C., more preferably
>100.degree. C., most preferably >110.degree. C. In some
embodiments, the peak tan delta temperature is no greater than
150.degree. C., 140.degree. C., 135.degree. C., or 130.degree. C.
Articles which displayed high 30 minute relaxation modulus
displayed tan delta peaks >60.degree. C. Articles which
displayed both high elongation and high 30 minute relaxation
modulus displayed a peak in the loss modulus below 20.degree. C.
and a tan delta peak greater than 60.degree. C. Loss modulus and
tan delta are explained, for instance, in Sepe, M. P. (1998 Dynamic
Mechanical Analysis for Plastics Engineering. William Andrew
Publishing/Plastics Design Library).
[0147] In at least certain embodiments of orthodontic articles of
the present disclosure, the articles are advantageously more
resistant to staining than articles made from different, more
hydrophilic components. For instance, dyes and other colored
materials in beverages are typically hydrophilic, thus they will
have a greater affinity for a more hydrophilic composition than a
more hydrophobic composition.
[0148] In certain embodiments, an orthodontic article comprises 2
wt. % or less extractable components, 1 wt. % or less, 0.75 wt. %
or less, 0.5 wt. % or less, or even 0.1% or less extractable
components, based on the total weight of the article. Either an
organic solvent or water can be used to extract component, as
described in detail in the Examples below. Post-processing of the
orthodontic article to assist in achieving a low extractable
component-containing article is discussed in more detail below.
[0149] The above mechanical properties are particularly well suited
for orthodontic articles that require resiliency and flexibility,
along with adequate wear strength and low hygroscopicity.
Methods
[0150] In a second aspect, the present disclosure provides a method
of making an orthodontic article. The method comprises: [0151] a)
obtaining a photopolymerizable composition comprising: [0152] i) a
monofunctional (meth)acrylate monomer whose cured homopolymer has a
T.sub.g of 90.degree. C. or greater; [0153] ii) a photoinitiator;
[0154] and [0155] iii) a polymerization reaction product of
components, the components comprising: [0156] 1) an isocyanate;
[0157] 2) a (meth)acrylate mono-ol; [0158] 3) a polycarbonate diol
of Formula (I):
[0158] H(O--R.sub.1--O--C(.dbd.O)).sub.mO--R.sub.2--OH (I) [0159]
wherein each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or [0160] aliphatic/cycloaliphatic alkylene group
and an average number of carbon atoms in a combination of all the
R.sub.1 and R.sub.2 groups is 4 to 10, and m is 2 to 23; and [0161]
4) a catalyst; [0162] b) selectively curing the photopolymerizable
composition; and [0163] c) repeating steps a) and b) to form
multiple layers and create the orthodontic article.
[0164] Photopolymerizable compositions described herein can be
mixed by known techniques. In some embodiments, for instance, a
method for the preparation of a photopolymerizable composition
described herein comprises the steps of mixing all or substantially
all of the components of the photopolymerizable composition,
heating the mixture, and optionally filtering the heated mixture.
Softening the mixture, in some embodiments, is carried out at a
temperature of about 50.degree. C. or in a range from about
50.degree. C. to about 85.degree. C. In some embodiments, a
photopolymerizable composition described herein is produced by
placing all or substantially all components of the composition in a
reaction vessel and heating the resulting mixture to a temperature
ranging from about 50.degree. C. to about 85.degree. C. with
stirring. The heating and stirring are continued until the mixture
attains a substantially homogenized state.
[0165] In many embodiments, the photopolymerizable composition is
vat polymerized, as discussed in detail below.
[0166] The shape of the article is not limited, and typically
comprises a shaped integral article, in which more than one
variation in dimension is provided by a single integral article.
For example, the article can comprise one or more channels, one or
more undercuts, one or more perforations, or combinations thereof.
Such features are typically not possible to provide in an integral
article using conventional molding methods. Specific orthodontic
articles are described in further detail below.
[0167] The components of the photopolymerizable composition are as
discussed in detail above. In many embodiments, the
photopolymerizable composition is cured using actinic radiation
comprising UV radiation, e-beam radiation, visible radiation, or a
combination thereof. Moreover, the method optionally further
comprises post curing the orthodontic article using actinic
radiation.
[0168] In certain embodiments, the method comprises vat
polymerization of the photopolymerizable composition. When vat
polymerization is employed, the radiation may be directed through a
wall of a container (e.g., a vat) holding the photopolymerizable
composition, such as a side wall or a bottom wall.
[0169] A photopolymerizable composition described herein in a cured
state, in some embodiments, can exhibit one or more desired
properties. A photopolymerizable composition in a "cured" state can
comprise a photopolymerizable composition that includes a
polymerizable component that has been at least partially
polymerized and/or crosslinked. For instance, in some instances, a
cured article is at least about 10% polymerized or crosslinked or
at least about 30% polymerized or crosslinked. In some cases, a
cured photopolymerizable composition is at least about 50%, at
least about 70%, at least about 80%, or at least about 90%
polymerized or crosslinked. A cured photopolymerizable composition
can also be between about 10% and about 99% polymerized or
crosslinked.
Fabricating an Orthodontic Article
[0170] Once prepared as set forth above, the photopolymerizable
compositions of the present disclosure may be used in myriad
additive manufacturing processes to create a variety of e.g.,
orthodontic articles. A generalized method 100 for creating
three-dimensional articles is illustrated in FIG. 1. Each step in
the method will be discussed in greater detail below. First, in
Step 110 the desired photopolymerizable composition (e.g.,
comprising at least one polyurethane (meth)acrylate polymer) is
provided and introduced into a reservoir, cartridge, or other
suitable container for use by or in an additive manufacturing
device. The additive manufacturing device selectively cures the
photopolymerizable composition according to a set of computerized
design instructions in Step 120. In Step 130, Step 110 and/or Step
120 is repeated to form multiple layers to create the article
comprising a three-dimensional structure (i.e., an orthodontic
article). Optionally uncured photopolymerizable composition is
removed from the article in Step 140, further optionally, the
article is subjected to additional curing to polymerize remaining
uncured photopolymerizable components in the article in Step 150,
and yet further optionally, the article is subjected to a heat
treatment in Step 160.
[0171] Methods of printing a three-dimensional article or object
described herein can include forming the article from a plurality
of layers of a photopolymerizable composition described herein in a
layer-by-layer manner. Further, the layers of a build material
composition can be deposited according to an image of the
three-dimensional article in a computer readable format. In some or
all embodiments, the photopolymerizable composition is deposited
according to preselected computer aided design (CAD)
parameters.
[0172] Additionally, it is to be understood that methods of
manufacturing a 3D article described herein can include so-called
"stereolithography/vat polymerization" 3D printing methods. Other
techniques for three-dimensional manufacturing are known, and may
be suitably adapted to use in the applications described herein.
More generally, three-dimensional fabrication techniques continue
to become available. All such techniques may be adapted to use with
photopolymerizable compositions described herein, provided they
offer compatible fabrication viscosities and resolutions for the
specified article properties. Fabrication may be performed using
any of the fabrication technologies described herein, either alone
or in various combinations, using data representing a
three-dimensional object, which may be reformatted or otherwise
adapted as necessary for a particular printing or other fabrication
technology.
[0173] It is entirely possible to form a 3D article from a
photopolymerizable composition described herein using vat
polymerization (e.g., stereolithography). For example, in some
cases, a method of printing a 3D article comprises retaining a
photopolymerizable composition described herein in a fluid state in
a container and selectively applying energy to the
photopolymerizable composition in the container to solidify at
least a portion of a fluid layer of the photopolymerizable
composition, thereby forming a hardened layer that defines a
cross-section of the 3D article. Additionally, a method described
herein can further comprise raising or lowering the hardened layer
of photopolymerizable composition to provide a new or second fluid
layer of unhardened photopolymerizable composition at the surface
of the fluid in the container, followed by again selectively
applying energy to the photopolymerizable composition in the
container to solidify at least a portion of the new or second fluid
layer of the photopolymerizable composition to form a second
solidified layer that defines a second cross-section of the 3D
article. Further, the first and second cross-sections of the 3D
article can be bonded or adhered to one another in the z-direction
(or build direction corresponding to the direction of raising or
lowering recited above) by the application of the energy for
solidifying the photopolymerizable composition. Moreover,
selectively applying energy to the photopolymerizable composition
in the container can comprise applying actinic radiation, such as
UV radiation, visible radiation, or e-beam radiation, having a
sufficient energy to cure the photopolymerizable composition. A
method described herein can also comprise planarizing a new layer
of fluid photopolymerizable composition provided by raising or
lowering an elevator platform. Such planarization can be carried
out, in some cases, by utilizing a wiper or roller or a recoater.
Planarization corrects the thickness of one or more layers prior to
curing the material by evening the dispensed material to remove
excess material and create a uniformly smooth exposed or flat
up-facing surface on the support platform of the printer.
[0174] It is further to be understood that the foregoing process
can be repeated a selected number of times to provide the 3D
article. For example, in some cases, this process can be repeated
"n" number of times. Further, it is to be understood that one or
more steps of a method described herein, such as a step of
selectively applying energy to a layer of photopolymerizable
composition, can be carried out according to an image of the 3D
article in a computer-readable format. Suitable stereolithography
printers include the Viper Pro SLA, available from 3D Systems, Rock
Hill, S.C. and the Asiga PICO PLUS 39, available from Asiga USA,
Anaheim Hills, Calif.
[0175] FIG. 2 shows an exemplary stereolithography apparatus
("SLA") that may be used with the photopolymerizable compositions
and methods described herein. In general, the SLA 200 may include a
laser 202, optics 204, a steering lens 206, an elevator 208, a
platform 210, and a straight edge 212, within a vat 214 filled with
the photopolymerizable composition. In operation, the laser 202 is
steered across a surface of the photopolymerizable composition to
cure a cross-section of the photopolymerizable composition, after
which the elevator 208 slightly lowers the platform 210 and another
cross section is cured. The straight edge 212 may sweep the surface
of the cured composition between layers to smooth and normalize the
surface prior to addition of a new layer. In other embodiments, the
vat 214 may be slowly filled with liquid resin while an article is
drawn, layer by layer, onto the top surface of the
photopolymerizable composition.
[0176] A related technology, vat polymerization with Digital Light
Processing ("DLP"), also employs a container of curable polymer
(e.g., photopolymerizable composition). However, in a DLP based
system, a two-dimensional cross section is projected onto the
curable material to cure the desired section of an entire plane
transverse to the projected beam at one time. All such curable
polymer systems as may be adapted to use with the
photopolymerizable compositions described herein are intended to
fall within the scope of the term "vat polymerization system" as
used herein. In certain embodiments, an apparatus adapted to be
used in a continuous mode may be employed, such as an apparatus
commercially available from Carbon 3D, Inc. (Redwood City, Calif.),
for instance as described in U.S. Pat. Nos. 9,205,601 and 9,360,757
(both to DeSimone et al.).
[0177] Referring to FIG. 5, a general schematic is provided of
another SLA apparatus that may be used with photopolymerizable
compositions and methods described herein. In general, the
apparatus 500 may include a laser 502, optics 504, a steering lens
506, an elevator 508, and a platform 510, within a vat 514 filled
with the photopolymerizable composition 519. In operation, the
laser 502 is steered through a wall 520 (e.g., the floor) of the
vat 514 and into the photopolymerizable composition to cure a
cross-section of the photopolymerizable composition 519 to form an
article 517, after which the elevator 508 slightly raises the
platform 510 and another cross section is cured.
[0178] More generally, the photopolymerizable composition is
typically cured using actinic radiation, such as UV radiation,
e-beam radiation, visible radiation, or any combination thereof.
The skilled practitioner can select a suitable radiation source and
range of wavelengths for a particular application without undue
experimentation.
[0179] After the 3D article has been formed, it is typically
removed from the additive manufacturing apparatus and rinsed,
(e.g., an ultrasonic, or bubbling, or spray rinse in a solvent,
which would dissolve a portion of the uncured photopolymerizable
composition but not the cured, solid state article (e.g., green
body). Any other conventional method for cleaning the article and
removing uncured material at the article surface may also be
utilized. At this stage, the three-dimensional article typically
has sufficient green strength for handling in the remaining
optional steps of method 100.
[0180] It is expected in certain embodiments of the present
disclosure that the formed article obtained in Step 120 will shrink
(i.e., reduce in volume) such that the dimensions of the article
after (optional) Step 150 will be smaller than expected. For
example, a cured article may shrink less than 5% in volume, less
than 4%, less than 3%, less than 2%, or even less than 1% in
volume, which is contrast to other compositions that provide
articles that shrink about 6-8% in volume upon optional post
curing. The amount of volume percent shrinkage will not typically
result in a significant distortion in the shape of the final
object. It is particularly contemplated, therefore, that dimensions
in the digital representation of the eventual cured article may be
scaled according to a global scale factor to compensate for this
shrinkage. For example, in some embodiments, at least a portion of
the digital article representation can be at least 101% of the
desired size of the printed appliance, in some embodiments at least
102%, in some embodiments at least 104%, in some embodiments, at
least 105%, and in some embodiments, at least 110%.
[0181] A global scale factor may be calculated for any given
photopolymerizable composition formulation by creating a
calibration part according to Steps 110 and 120 above. The
dimensions of the calibration article can be measured prior to post
curing.
[0182] In general, the three-dimensional article formed by initial
additive manufacturing in Step 120, as discussed above, is not
fully cured, by which is meant that not all of the
photopolymerizable material in the composition has polymerized even
after rinsing. Some uncured photopolymerizable material is
typically removed from the surface of the printed article during a
cleaning process (e.g., optional Step 140). The article surface, as
well as the bulk article itself, typically still retains uncured
photopolymerizable material, suggesting further cure. Removing
residual uncured photopolymerizable composition is particularly
useful when the article is going to subsequently be post cured, to
minimize uncured residual photopolymerizable composition from
undesirably curing directly onto the article.
[0183] Further curing can be accomplished by further irradiating
with actinic radiation, heating, or both. Exposure to actinic
radiation can be accomplished with any convenient radiation source,
generally UV radiation, visible radiation, and/or e-beam radiation,
for a time ranging from about 10 to over 60 minutes. Heating is
generally carried out at a temperature in the range of about
75-150.degree. C., for a time ranging from about 10 to over 60
minutes in an inert atmosphere. So called post cure ovens, which
combine UV radiation and thermal energy, are particularly well
suited for use in the post cure processes of Step 150 and/or Step
160. In general, post curing improves the mechanical properties and
stability of the three-dimensional article relative to the same
three-dimensional article that is not post cured.
[0184] One particularly attractive opportunity for 3D printing is
in the direct creation of orthodontic clear tray aligners. These
trays, also known as aligners or polymeric or shell appliances, are
provided in a series and are intended to be worn in succession,
over a period of months, in order to gradually move the teeth in
incremental steps towards a desired target arrangement. Some types
of clear tray aligners have a row of tooth-shaped receptacles for
receiving each tooth of the patient's dental arch, and the
receptacles are oriented in slightly different positions from one
appliance to the next in order to incrementally urge each tooth
toward its desired target position by virtue of the resilient
properties of the polymeric material. A variety of methods have
been proposed in the past for manufacturing clear tray aligners and
other resilient appliances. Typically, positive dental arch models
are fabricated for each dental arch using additive manufacturing
methods such as stereolithography described above. Subsequently, a
sheet of polymeric material is placed over each of the arch models
and formed under heat, pressure and/or vacuum to conform to the
model teeth of each model arch. The formed sheet is cleaned and
trimmed as needed and the resulting arch-shaped appliance is
shipped along with the desired number of other appliances to the
treating professional.
[0185] An aligner or other resilient appliance created directly by
3D printing would eliminate the need to print a mold of the dental
arch and further thermoform the appliance. It also would allow new
aligner designs and give more degrees of freedom in the treatment
plan. Exemplary methods of direct printing clear tray aligners and
other resilient orthodontic apparatuses are set forth in PCT
Publication Nos. WO2016/109660 (Raby et al.), WO2016/148960
(Cinader et al.), and WO2016/149007 (Oda et al.) as well as US
Publication Nos. US2011/0091832 (Kim, et al.) and US2013/0095446
(Kitching).
[0186] The following describes general methods for creating a clear
tray aligner as printed appliance 300. However, other dental and
orthodontic articles can be created using similar techniques and
the photopolymerizable compositions of the present disclosure.
Representative examples include, but are not limited to, the
removable appliances having occlusal windows described in
International Application Publication No. WO2016/109660 (Raby et
al.), the removable appliances with a palatal plate described in US
Publication No. 2014/0356799 (Cinader et al); and the resilient
polymeric arch members described in International Application Nos.
WO2016/148960 and WO2016/149007 (Oda et al.); as well as US
Publication No. 2008/0248442 (Cinader et al.). Moreover, the
photopolymerizable compositions can be used in the creation of
indirect bonding trays, such as those described in International
Publication No. WO2015/094842 (Paehl et al.) and US Publication No.
2011/0091832 (Kim, et al.) and other dental articles, including but
not limited to crowns, bridges, veneers, inlays, onlays, fillings,
and prostheses (e.g., partial or full dentures). Other orthodontic
appliances and devices include, but not limited to, orthodontic
brackets, buccal tubes, lingual retainers, orthodontic bands, class
II and class III correctors, sleep apnea devices, bite openers,
buttons, cleats, and other attachment devices.
Fabricating an Orthodontic Appliance with the Photopolymerizable
Compositions
[0187] One particularly interesting implementation of an article is
generally depicted in FIG. 3. The additive manufactured article 300
is a clear tray aligner and is removably positionable over some or
all of a patient's teeth. In some embodiments, the appliance 300 is
one of a plurality of incremental adjustment appliances. The
appliance 300 may comprise a shell having an inner cavity. The
inner cavity is shaped to receive and resiliently reposition teeth
from one tooth arrangement to a successive tooth arrangement. The
inner cavity may include a plurality of receptacles, each of which
is adapted to connect to and receive a respective tooth of the
patient's dental arch. The receptacles are spaced apart from each
other along the length of the cavity, although adjoining regions of
adjacent receptacles can be in communication with each other. In
some embodiments, the shell fits over all teeth present in the
upper jaw or lower jaw. Typically, only certain one(s) of the teeth
will be repositioned while others of the teeth will provide a base
or anchor region for holding the dental appliance in place as it
applies the resilient repositioning force against the tooth or
teeth to be treated.
[0188] In order to facilitate positioning of the teeth of the
patient, at least one of the receptacles may be aligned to apply
rotational and/or translational forces to the corresponding tooth
of the patient when the appliance 300 is worn by the patient in
order to eventually align said tooth to a new desired position. In
some particular examples, the appliance 300 may be configured to
provide only compressive or linear forces. In the same or different
examples, the appliance 300 may be configured to apply
translational forces to one or more of the teeth within
receptacles.
[0189] In some embodiments, the shell of the appliance 300 fits
over some or all anterior teeth present in an upper jaw or lower
jaw. Typically, only certain one(s) of the teeth will be
repositioned while others of the teeth will provide a base or
anchor region for holding the appliance in place as it applies the
resilient repositioning force against the tooth or teeth to be
repositioned. An appliance 300 can accordingly be designed such
that any receptacle is shaped to facilitate retention of the tooth
in a particular position in order to maintain the current position
of the tooth.
[0190] A method 400 of creating an orthodontic appliance using the
photopolymerizable compositions of the present disclosure can
include general steps as outlined in FIG. 4. Individual aspects of
the process are discussed in further detail below. The process
includes generating a treatment plan for repositioning a patient's
teeth. Briefly, a treatment plan can include obtaining data
representing an initial arrangement of the patient's teeth (Step
410), which typically includes obtaining an impression or scan of
the patient's teeth prior to the onset of treatment. The treatment
plan will also include identifying a final or target arrangement of
the patient's anterior and posterior teeth as desired (Step 420),
as well as a plurality of planned successive or intermediary tooth
arrangements for moving at least the anterior teeth along a
treatment path from the initial arrangement toward the selected
final or target arrangement (Step 430). One or more appliances can
be virtually designed based on the treatment plan (Step 440), and
image data representing the appliance designs can exported in STL
format, or in any other suitable computer processable format, to an
additive manufacturing device (e.g., a 3D printer system) (Step
450). An appliance can be manufactured using a photopolymerizable
composition of the present disclosure retained in the additive
manufacturing device (Step 460).
[0191] In some embodiments, a (e.g., non-transitory)
machine-readable medium is employed in additive manufacturing of
articles according to at least certain aspects of the present
disclosure. Data is typically stored on the machine-readable
medium. The data represents a three-dimensional model of an
article, which can be accessed by at least one computer processor
interfacing with additive manufacturing equipment (e.g., a 3D
printer, a manufacturing device, etc.). The data is used to cause
the additive manufacturing equipment to create an article
comprising a reaction product of a photopolymerizable composition,
the photopolymerizable composition includes a blend of: i) a
monofunctional (meth)acrylate monomer whose cured homopolymer has a
T.sub.g of 90.degree. C. or greater; ii) a photoinitiator; and iii)
a polymerization reaction product of components. The components
include 1) an isocyanate; 2) a (meth)acrylate mono-ol; a
polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 3) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is (an integer of) 2 to 23.
The polymerized reaction product of the photopolymerizable
composition has a shape of the orthodontic article. The details of
the photopolymerizable composition are as described above.
[0192] Data representing an article may be generated using computer
modeling such as computer aided design (CAD) data. Image data
representing the (e.g., polymeric) article design can be exported
in STL format, or in any other suitable computer processable
format, to the additive manufacturing equipment. Scanning methods
to scan a three-dimensional object may also be employed to create
the data representing the article. One exemplary technique for
acquiring the data is digital scanning Any other suitable scanning
technique may be used for scanning an article, including X-ray
radiography, laser scanning, computed tomography (CT), magnetic
resonance imaging (MRI), and ultrasound imaging. Other possible
scanning methods are described, e.g., in U.S. Patent Application
Publication No. 2007/0031791 (Cinader, Jr., et al.). The initial
digital data set, which may include both raw data from scanning
operations and data representing articles derived from the raw
data, can be processed to segment an article design from any
surrounding structures (e.g., a support for the article). In select
embodiments, scanning techniques may include, for example, scanning
a patient's mouth to customize an orthodontic article for the
patient.
[0193] Often, machine-readable media are provided as part of a
computing device. The computing device may have one or more
processors, volatile memory (RAM), a device for reading
machine-readable media, and input/output devices, such as a
display, a keyboard, and a pointing device. Further, a computing
device may also include other software, firmware, or combinations
thereof, such as an operating system and other application
software. A computing device may be, for example, a workstation, a
laptop, a personal digital assistant (PDA), a server, a mainframe
or any other general-purpose or application-specific computing
device. A computing device may read executable software
instructions from a computer-readable medium (such as a hard drive,
a CD-ROM, or a computer memory), or may receive instructions from
another source logically connected to computer, such as another
networked computer. Referring to FIG. 10, a computing device 1000
often includes an internal processor 1080, a display 1100 (e.g., a
monitor), and one or more input devices such as a keyboard 1140 and
a mouse 1120. In FIG. 10, an aligner article 1130 is shown on the
display 1100.
[0194] Referring to FIG. 6, in certain embodiments, the present
disclosure provides a system 600. The system 600 comprises a
display 620 that displays a 3D model 610 of an article (e.g., an
aligner 1130 as shown on the display 1100 of FIG. 10); and one or
more processors 630 that, in response to the 3D model 610 selected
by a user, cause a 3D printer/additive manufacturing device 650 to
create a physical object of the article 660. Often, an input device
640 (e.g., keyboard and/or mouse) is employed with the display 620
and the at least one processor 630, particularly for the user to
select the 3D model 610. The article 660 comprises a reaction
product of a photopolymerizable composition, the photopolymerizable
composition includes a blend of: i) a monofunctional (meth)acrylate
monomer whose cured homopolymer has a T.sub.g of 90.degree. C. or
greater; ii) a photoinitiator; and iii) a polymerization reaction
product of components. The components include 1) an isocyanate; 2)
a (meth)acrylate mono-ol; a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 3) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article. The details of the photopolymerizable
composition are as described above.
[0195] Referring to FIG. 7, a processor 720 (or more than one
processor) is in communication with each of a machine-readable
medium 710 (e.g., a non-transitory medium), a 3D printer/additive
manufacturing device 740, and optionally a display 730 for viewing
by a user. The 3D printer/additive manufacturing device 740 is
configured to make one or more articles 750 based on instructions
from the processor 720 providing data representing a 3D model of
the article 750 (e.g., an aligner article 1130 as shown on the
display 1100 of FIG. 10) from the machine-readable medium 710.
[0196] Referring to FIG. 8, for example and without limitation, an
additive manufacturing method comprises retrieving 810, from a
(e.g., non-transitory) machine-readable medium, data representing a
3D model of an article according to at least one embodiment of the
present disclosure. The method further includes executing 820, by
one or more processors, an additive manufacturing application
interfacing with a manufacturing device using the data; and
generating 830, by the manufacturing device, a physical object of
the article. The additive manufacturing equipment can selectively
cure a photopolymerizable composition to form an article. The
article comprises a reaction product of a photopolymerizable
composition, the photopolymerizable composition includes a blend
of: i) a monofunctional (meth)acrylate monomer whose cured
homopolymer has a T.sub.g of 90.degree. C. or greater; ii) a
photoinitiator; and iii) a polymerization reaction product of
components. The components include 1) an isocyanate; 2) a
(meth)acrylate mono-ol; a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 3) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article. The details of the photopolymerizable
composition are as described above. One or more various optional
post-processing steps 840 may be undertaken. Typically, remaining
unpolymerized photopolymerizable component may be cured. The
article comprises an orthodontic article.
[0197] Additionally, referring to FIG. 9, a method of making an
article comprises receiving 910, by a manufacturing device having
one or more processors, a digital object comprising data specifying
a plurality of layers of an article; and generating 920, with the
manufacturing device by an additive manufacturing process, the
article based on the digital object. Again, the article may undergo
one or more steps of post-processing 930.
Select Embodiments of the Disclosure
[0198] Embodiment 1 is an orthodontic article. The orthodontic
article includes a reaction product of a photopolymerizable
composition. The photopolymerizable composition includes a) a
polymerized reaction product of a photopolymerizable composition.
The photopolymerizable composition includes i) a monofunctional
(meth)acrylate monomer whose cured homopolymer has a T.sub.g of
90.degree. C. or greater; ii) a photoinitiator; and iii) a
polymerization reaction product of components. The components
include 1) an isocyanate; 2) a (meth)acrylate mono-ol; 3) a
polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0199] Embodiment 2 is the orthodontic article of embodiment 1,
wherein the (meth)acrylate mono-ol is of Formula (II): HO-Q-(A)
(II). Q is a polyvalent organic linking group, A is a (meth)acryl
functional group of the formula
--XC(.dbd.O)C(R.sub.3).dbd.CH.sub.2, wherein X is O, S, or
NR.sub.4, R.sub.4 is H or alkyl of 1 to 4 carbon atoms, R.sub.3 is
a lower alkyl of 1 to 4 carbon atoms or H, and wherein p is 1 or
2.
[0200] Embodiment 3 is the orthodontic article of embodiment 2,
wherein in the hydroxy functional (meth)acrylate of Formula (II), Q
is an alkylene group, p is 1, and in the (meth)acryl functional
group A, X is O and R.sub.3 is methyl or H.
[0201] Embodiment 4 is the orthodontic article of embodiment 2 or
embodiment 3, wherein in the hydroxy functional (meth)acrylate of
Formula (II), Q is an alkylene group, p is 1, and in the
(meth)acryl functional group A, X is O and R.sub.3 is methyl.
[0202] Embodiment 5 is the orthodontic article of any of
embodiments 1 to 4, wherein the photopolymerizable composition
further includes a compound of Formula (III):
(H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--X).sub.p-Q-OC(.dbd.O)NH--R.sub.di--NH-
C(.dbd.O)O-Q-(X--C(.dbd.O)(R.sub.3)C.dbd.CH.sub.2).sub.p (III).
X, Q, p, and R.sub.3 are as defined for Formula (II), and R.sub.d,
is the residue of a diisocyanate.
[0203] Embodiment 6 is the orthodontic article of embodiment 5,
wherein the compound of Formula (III) is produced during the
polymerization of the components.
[0204] Embodiment 7 is the orthodontic article of embodiment 5 or
embodiment 6, wherein the compound of Formula (III) is added to the
photopolymerizable composition.
[0205] Embodiment 8 is the orthodontic article of any of
embodiments 5 to 7, wherein the compound of Formula (III) is
present in an amount of 0.05 to 20 weight percent (wt. %), based on
the weight of the polymerizable composition.
[0206] Embodiment 9 is the orthodontic article of any of
embodiments 5 to 8, wherein the compound of Formula (III) is
present in an amount of 1.5 to 12 wt. %, based on the weight of the
polymerizable composition.
[0207] Embodiment 10 is the orthodontic article of any of
embodiments 5 to 8, wherein the compound of Formula (III) is
present in an amount of 5 to 20 wt. %, based on the weight of the
polymerizable composition.
[0208] Embodiment 11 is the orthodontic article of any of
embodiments 5 to 10, wherein X is O in the compound of Formula
(III).
[0209] Embodiment 12 is the orthodontic article of any of
embodiments 5 to 11, wherein the compound of Formula (III) is of
Formula (IV):
##STR00006##
[0210] Embodiment 13 is the orthodontic article of any of
embodiments 1 to 12, wherein the photopolymerizable composition
further includes a difunctional (meth)acrylate monomer or
oligomer.
[0211] Embodiment 14 is the orthodontic article of any of
embodiments 1 to 13, wherein the monofunctional (meth)acrylate
monomer is selected from the group consisting of dicyclopentadienyl
acrylate, dicyclopentanyl acrylate, isobornyl acrylate,
dimethyl-1-adamantyl acrylate, cyclohexyl methacrylate, butyl
methacrylate (e.g., tert-butyl methacrylate),
3,3,5-trimethylcyclohexyl methacrylate,
butyl-cyclohexylmethacrylate (e.g.,
cis-4-tert-butyl-cyclohexylmethacrylate, 73/27
trans/cis-4-tert-butylcyclohexylmethacrylate, and/or
trans-4-tert-butylcyclohexyl methacrylate) 2-decahydronapthyl
methacrylate, 1-adamantyl acrylate, dicyclopentadienyl
methacrylate, isobornyl methacrylate (e.g., d,l-isobornyl
methacrylate), dimethyl-1-adamantyl methacrylate, bornyl
methacrylate (e.g., d,l-bornyl methacrylate),
3-tetracyclo[4.4.0.1.1]dodecyl methacrylate, 1-adamantyl
methacrylate, or combinations thereof.
[0212] Embodiment 15 is the orthodontic article of any of
embodiments 1 to 14, wherein a weight ratio of the monofunctional
(meth)acrylate monomer to the polyurethane (meth)acrylate polymer
is 60:40 to 40:60.
[0213] Embodiment 16 is the orthodontic article of any of
embodiments 1 to 15, wherein a weight ratio of the monofunctional
(meth)acrylate monomer to the polyurethane (meth)acrylate polymer
is 55:45 to 45:55.
[0214] Embodiment 17 is the orthodontic article of any of
embodiments 1 to 16, wherein the isocyanate includes a diisocyanate
selected from the group consisting of 2,6-toluene diisocyanate
(TDI), methylenedicyclohexylene-4,4'-diisocyanate (H12MDI),
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),
1,6-diisocyanatohexane (HDI), tetramethyl-m-xylylene diisocyanate,
a mixture of 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexame
(TMXDI), trans-1,4-hydrogenated xylylene diisocyanates
(H.sub.6XDI), or combinations thereof.
[0215] Embodiment 18 is the orthodontic article of any of
embodiments 1 to 17, wherein the isocyanate includes IPDI.
[0216] Embodiment 19 is the orthodontic article of any of
embodiments 1 to 18, wherein the polycarbonate diol has a molecular
weight of 450 grams per mole (g/mol) to 3,200 g/mol, or 1,800 g/mol
to 3,200 g/mol.
[0217] Embodiment 20 is the orthodontic article of any of
embodiments 1 to 19, wherein the polycarbonate diol has a molecular
weight of 800 g/mol to 2,200 g/mol or 1,800 g/mol to 2,200
g/mol
[0218] Embodiment 21 is the orthodontic article of any of
embodiments 1 to 20, wherein the photopolymerizable composition has
a solids content of 95% to 100% solids.
[0219] Embodiment 22 is the orthodontic article of any of
embodiments 1 to 21, wherein the photopolymerizable composition has
a solids content of 100% solids.
[0220] Embodiment 23 is the orthodontic article of any of
embodiments 1 to 22, wherein the photopolymerizable composition
further includes a UV absorber comprising an optical brightener in
an amount of 0.001 to 5% by weight, based on the total weight of
the photopolymerizable composition.
[0221] Embodiment 24 is the orthodontic article of embodiment 23,
wherein the optical brightener includes a compound of Formula
(V):
##STR00007##
[0222] Embodiment 25 is the orthodontic article of any of
embodiments 1 to 24, wherein the photopolymerizable composition
further includes an inhibitor in an amount of 0.001 to 1 wt. %,
based on the total weight of the photopolymerizable
composition.
[0223] Embodiment 26 is the orthodontic article of any of
embodiments 1 to 25, wherein the photoinitiator is present in an
amount of 0.2 to 5 wt. %, based on the total weight of the
photopolymerizable composition.
[0224] Embodiment 27 is the orthodontic article of any of
embodiments 1 to 26, wherein the catalyst contains zinc.
[0225] Embodiment 28 is the orthodontic article of any of
embodiments 1 to 27, wherein the catalyst includes an
organometallic zinc complex and is free of 2-ethylhexyl carboxylate
and 2-ethylhexanoic acid.
[0226] Embodiment 29 is the orthodontic article of any of
embodiments 1 to 28, wherein the catalyst is free of tin.
[0227] Embodiment 30 is the orthodontic article of any of
embodiments 1 to 29, wherein the catalyst contains bismuth.
[0228] Embodiment 31 is the orthodontic article of any of
embodiments 1 to 30, wherein the polyurethane (meth)acrylate
polymer has a weight average molecular weight (Mw) of 6,000 g/mol
to 35,000 g/mol.
[0229] Embodiment 32 is the orthodontic article of any of
embodiments 1 to 31, wherein the photopolymerizable composition
further includes a difunctional monomer in an amount of up to 15
wt. %, based on the total weight of the photopolymerizable
composition.
[0230] Embodiment 33 is the orthodontic article of embodiment 32,
wherein the difunctional monomer includes a compound of Formula
(X):
H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)X-Q-O--C(.dbd.O)NH--R.sub.dh--NHC(.dbd.O)-
--O-Q-XC(.dbd.O)C(R.sub.3).dbd.CH.sub.2 (X), wherein R.sub.dt is
the residue of a diisocyanate, Q, X, and R.sub.3 are as defined for
Formula (II).
[0231] Embodiment 34 is the orthodontic article of embodiment 32,
wherein the difunctional monomer includes a compound of Formula
(XI):
H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--O-Q-NH--C(.dbd.O)--(O--R.sub.1--O--C(.d-
bd.O)).sub.m--O--R.sub.2--O--C(.dbd.O)NH-Q-O--C(.dbd.O)C(R.sub.3).dbd.CH.s-
ub.2 (XI) wherein Q and R.sub.3 are as defined for Formula (II) and
R.sub.1 and R.sub.2 are as defined for Formula (I).
[0232] Embodiment 35 is the orthodontic article of any of
embodiments 1 to 34, wherein a ratio of the isocyanate to the
polycarbonate diol ranges from 4 molar equivalents of the
isocyanate to 1 molar equivalent of the alcohol of the
polycarbonate diol, to 4 molar equivalents of the isocyanate to 3
molar equivalents of the alcohol of the polycarbonate diol.
[0233] Embodiment 36 is the orthodontic article of embodiment 35,
wherein the ratio of the isocyanate to the alcohol of the
polycarbonate diol is 4 molar equivalents of isocyanate to 2 molar
equivalents of the alcohol of the polycarbonate diol.
[0234] Embodiment 37 is the orthodontic article of any of
embodiments 1 to 36, wherein a ratio of the isocyanate to the
(meth)acrylate mono-ol ranges from 4 molar equivalents of the
isocyanate to 3 molar equivalents of the (meth)acrylate mono-ol to
4 molar equivalents of the isocyanate to 1 molar equivalent of the
(meth)acrylate mono-ol.
[0235] Embodiment 38 is the orthodontic article of any of
embodiments 1 to 37, wherein a ratio of the isocyanate to the
(meth)acrylate mono-ol is 4 molar equivalents of the isocyanate to
2 molar equivalents of the (meth)acrylate mono-ol.
[0236] Embodiment 39 is the orthodontic article of any of
embodiments 1 to 38, wherein a ratio of the polycarbonate diol to
the (meth)acrylate mono-ol ranges from 1 molar equivalent of the
alcohol of the polycarbonate diol to 3 molar equivalents of the
(meth)acrylate mono-ol, to 3 molar equivalents of the alcohol of
the polycarbonate diol to 1 molar equivalents of the (meth)acrylate
mono-ol.
[0237] Embodiment 40 is the orthodontic article of any of
embodiments 1 to 39, wherein a ratio of the polycarbonate diol to
the (meth)acrylate mono-ol is 1 molar equivalent of the alcohol of
the polycarbonate diol to 1 molar equivalent of the (meth)acrylate
mono-ol.
[0238] Embodiment 41 is the orthodontic article of any of
embodiments 1 to 40, wherein the polyurethane (meth)acrylate is of
Formula (VI):
(A).sub.p-Q-OC(O)NH--R.sub.d--NH--C(O)--[O--R.sub.dOH--OC(O)NH--R.sub.dh-
--NH--C(O)].sub.r--O-Q-(A).sub.p (VI)
[0239] wherein, A has the formula
--OC(.dbd.O)C(R.sub.3).dbd.CH.sub.2, wherein R.sub.3 is an alkyl of
1 to 4 carbon atoms (e.g. methyl) or H, p is 1 or 2, Q is a
polyvalent organic linking group as described above, Rai is the
residue of a diisocyanate, R.sub.dOH is the residue of a
polycarbonate polyol, and r averages from 1 to 15.
[0240] Embodiment 42 is the orthodontic article of any of claims 1
to 41, wherein the photopolymerizable composition further includes
a second polymerization reaction product of components. The
components include 1) an isocyanate functional (meth)acrylate
compound of Formula (VII): (A).sub.p-Q-NCO (VII), wherein A, p, and
Q are as defined for Formula (II); 2) a polycarbonate diol of
Formula (I): H(O--R.sub.1--O--C(.dbd.O)).sub.mO--R.sub.2--OH (I);
and 3) a catalyst. Each of R.sub.1 in each
(O--R.sub.1--O--C(.dbd.O)) repeat unit and each R.sub.2 are
independently an aliphatic, cycloaliphatic, or
aliphatic/cycloaliphatic alkylene group and an average number of
carbon atoms in a combination of all the R.sub.1 and R.sub.2 groups
is 4 to 10, and m is 2 to 23.
[0241] Embodiment 43 is the orthodontic article of any of
embodiments 1 to 42, wherein the second polymerization reaction
product includes a compound of Formula (VIII):
(H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--O).sub.p-Q-NH--C(.dbd.O)--(O--R.sub.1-
--O--C(.dbd.O)).sub.mO--R.sub.2--O--C(.dbd.O)NH-Q-(O--C(.dbd.O)(R.sub.3)C.-
dbd.CH.sub.2).sub.p (VIII).
Q, p, and R.sub.3 are as defined for Formula (II) and R.sub.1 and
R.sub.2 are as defined for Formula (I).
[0242] Embodiment 44 is the orthodontic article of embodiment 43,
wherein the compound of Formula (VIII) is a compound of Formula
(IX):
##STR00008##
[0243] wherein n is about 6.7 for a 1000 molecular weight
polycarbonate diol based on hexane diol
[0244] Embodiment 45 is the orthodontic article of any of
embodiments 1 to 44, wherein a cured homopolymer of the
monofunctional (meth)acrylate monomer has a T.sub.g of 100.degree.
C. or greater.
[0245] Embodiment 46 is the orthodontic article of any of
embodiments 1 to 45, wherein the cured homopolymer of the
monofunctional (meth)acrylate monomer has a T.sub.g of 170.degree.
C. or greater or 180.degree. C. or greater.
[0246] Embodiment 47 is the orthodontic article of any of
embodiments 1 to 46, wherein the monofunctional acrylate monomer
includes a cycloaliphatic monofunctional (meth)acrylate.
[0247] Embodiment 48 is the orthodontic article of any of
embodiments 1 to 47, wherein the monofunctional acrylate monomer
includes isobornyl methacrylate.
[0248] Embodiment 49 is the orthodontic article of any of
embodiments 1 to 48, exhibiting an initial relaxation modulus of
100 megapascals (MPa) or greater measured at 2% strain at
37.degree. C.
[0249] Embodiment 50 is the orthodontic article of any of
embodiments 1 to 49, exhibiting a percent loss of relaxation
modulus of 70% or less.
[0250] Embodiment 51 is the orthodontic article of any of
embodiments 1 to 50, exhibiting a percent loss of relaxation
modulus of 40% or less.
[0251] Embodiment 52 is the orthodontic article of any of
embodiments 1 to 51, exhibiting a relaxation modulus of 100 MPa or
greater.
[0252] Embodiment 53 is the orthodontic article of any of
embodiments 1 to 52, exhibiting an elongation at break of a printed
article of 20% or greater.
[0253] Embodiment 54 is the orthodontic article of any of
embodiments 1 to 53, exhibiting an elongation at break of a printed
article of 70% or greater.
[0254] Embodiment 55 is the orthodontic article of any of
embodiments 1 to 54, exhibiting a tensile strength at yield of 14
MPa or greater.
[0255] Embodiment 56 is the orthodontic article of any of
embodiments 1 to 55, exhibiting a tensile strength at yield of 25
MPa or greater
[0256] Embodiment 57 is the orthodontic article of any of
embodiments 1 to 56, including 1 wt. % or less extractable
components.
[0257] Embodiment 58 is the orthodontic article of any of
embodiments 1 to 57, exhibiting a peak in loss modulus of
20.degree. C. or less.
[0258] Embodiment 59 is the orthodontic article of embodiment 58,
exhibiting a tan delta peak of 80.degree. C. or greater.
[0259] Embodiment 60 is the orthodontic article of any of
embodiments 1 to 57, wherein the orthodontic article includes a
dental tray, a retainer, or an aligner.
[0260] Embodiment 61 is the orthodontic article of any of
embodiments 1 to 58, wherein the orthodontic article includes an
aligner.
[0261] Embodiment 62 is a method of making an orthodontic article.
The method includes a) obtaining a photopolymerizable composition;
b) selectively curing the photopolymerizable composition; and c)
repeating steps a) and b) to form multiple layers and create the
orthodontic article. The photopolymerizable composition includes i)
a monofunctional (meth)acrylate monomer whose cured homopolymer has
a T.sub.g of 90.degree. C. or greater; ii) a photoinitiator; and
iii) a polymerization reaction product of components. The
components include 1) an isocyanate; 2) a (meth)acrylate mono-ol;
3) a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the groups
R.sub.1 and R.sub.2 is 4 to 10, and m is 2 to 23.
[0262] Embodiment 63 is the method of embodiment 62, wherein the
photopolymerizable composition is cured using actinic radiation
including UV radiation, e-beam radiation, visible radiation, or a
combination thereof.
[0263] Embodiment 64 is the method of embodiment 63, wherein the
actinic radiation is directed through a wall of a container holding
the photopolymerizable composition.
[0264] Embodiment 65 is the method of embodiment 63 or embodiment
64, wherein 90% or greater of the actinic radiation is absorbed
over a distance of 150 micrometers of the photopolymerizable
composition.
[0265] Embodiment 66 is the method of any of embodiments 62 to 65,
wherein the photopolymerizable composition is cured through a floor
of a container holding the photopolymerizable composition.
[0266] Embodiment 67 is the method of any of embodiments 62 to 66,
further including post curing the orthodontic article using actinic
radiation.
[0267] Embodiment 68 is the method of any of embodiments 62 to 67,
wherein the method includes vat polymerization of the
photopolymerizable composition.
[0268] Embodiment 69 is the method of any of embodiments 62 to 68,
further including subjecting the orthodontic article to a heat
treatment.
[0269] Embodiment 70 is the method of any of embodiments 62 to 69,
wherein the photopolymerizable composition further includes at
least one filler.
[0270] Embodiment 71 is the method of any of embodiments 62 to 70,
wherein the photopolymerizable composition further includes at
least one filler selected from silica, alumina, zirconia, and
discontinuous fibers.
[0271] Embodiment 72 is the method of embodiment 71, wherein the
discontinuous fibers include carbon, ceramic, glass, or
combinations thereof.
[0272] Embodiment 73 is the method of any of embodiments 62 to 72,
wherein the (meth)acrylate mono-ol is of Formula (II):
HO-Q-(A).sub.p (II). Q is a polyvalent organic linking group, A is
a (meth)acryl functional group of the formula
--XC(.dbd.O)C(R.sub.3).dbd.CH.sub.2, wherein X is O, S, or
NR.sub.4, R.sub.4 is H or alkyl of 1 to 4 carbon atoms, R.sub.3 is
a lower alkyl of 1 to 4 carbon atoms or H, and wherein p is 1 or
2.
[0273] Embodiment 74 is the method of embodiment 73, wherein in the
hydroxy functional (meth)acrylate of Formula (II), Q is an alkylene
group, p is 1, and in the (meth)acryl functional group A, X is O
and R.sub.3 is methyl or H.
[0274] Embodiment 75 is the method of embodiment 73 or embodiment
74, wherein in the hydroxy functional (meth)acrylate of Formula
(II), Q is an alkylene group, p is 1, and in the (meth)acryl
functional group A, X is O and R.sub.3 is methyl.
[0275] Embodiment 76 is the method of any of claims 62 to 75,
wherein the photopolymerizable composition further includes a
compound of Formula (III):
(H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--X).sub.p-Q-OC(.dbd.O)NH--R.sub.di--NH-
C(.dbd.O)O-Q-(X--C(.dbd.O)(R.sub.3)C.dbd.CH.sub.2).sub.p (III).
X, Q, p, and R.sub.3 are as defined for Formula (II), and R.sub.d,
is the residue of a diisocyanate.
[0276] Embodiment 77 is the method of embodiment 76, wherein the
compound of Formula (III) is produced during the polymerization of
the components.
[0277] Embodiment 78 is the method of embodiment 76 or embodiment
77, wherein the compound of Formula (III) is added to the
photopolymerizable composition.
[0278] Embodiment 79 is the method of any of claims 76 to 78,
wherein the compound of Formula (III) is present in an amount of
0.05 to 20 weight percent (wt. %), based on the weight of the
polymerizable composition.
[0279] Embodiment 80 is the method of any of embodiments 76 to 79,
wherein the compound of Formula (III) is present in an amount of
1.5 to 12 wt. %, based on the weight of the polymerizable
composition.
[0280] Embodiment 81 is the method of any of embodiments 76 to 79,
wherein the compound of Formula (III) is present in an amount of 5
to 20 wt. %, based on the weight of the polymerizable
composition.
[0281] Embodiment 82 is the method of any of embodiments 76 to 81,
wherein X is O in the compound of Formula (III).
[0282] Embodiment 83 is the method of any of embodiments 76 to 82,
wherein the compound of Formula (III) is of Formula (IV):
##STR00009##
[0283] Embodiment 84 is the method of any of embodiments 62 to 83,
wherein the photopolymerizable composition further includes a
difunctional (meth)acrylate monomer or oligomer.
[0284] Embodiment 85 is the method of any of embodiments 62 to 84,
wherein the monofunctional (meth)acrylate monomer is selected from
the group consisting of dicyclopentadienyl acrylate,
dicyclopentanyl acrylate, isobornyl acrylate, dimethyl-1-adamantyl
acrylate, cyclohexyl methacrylate, butyl methacrylate (e.g.,
tert-butyl methacrylate), 3,3,5-trimethylcyclohexyl methacrylate,
butyl-cyclohexylmethacrylate (e.g.,
cis-4-tert-butyl-cyclohexylmethacrylate, 73/27
trans/cis-4-tert-butylcyclohexylmethacrylate, and/or
trans-4-tert-butylcyclohexyl methacrylate) 2-decahydronapthyl
methacrylate, 1-adamantyl acrylate, dicyclopentadienyl
methacrylate, isobornyl methacrylate (e.g., d,l-isobornyl
methacrylate), dimethyl-1-adamantyl methacrylate, bornyl
methacrylate (e.g., d,l-bornyl methacrylate),
3-tetracyclo[4.4.0.1.1]dodecyl methacrylate, 1-adamantyl
methacrylate, or combinations thereof.
[0285] Embodiment 86 is the method of any of embodiments 62 to 85,
wherein a weight ratio of the monofunctional (meth)acrylate monomer
to the polyurethane (meth)acrylate polymer is 60:40 to 40:60.
[0286] Embodiment 87 is the method of any of embodiments 62 to 86,
wherein a weight ratio of the monofunctional (meth)acrylate monomer
to the polyurethane (meth)acrylate polymer is 55:45 to 45:55.
[0287] Embodiment 88 is the method of any of embodiments 62 to 87,
wherein the isocyanate includes a diisocyanate selected from the
group consisting of 2,6-toluene diisocyanate (TDI),
methylenedicyclohexylene-4,4'-diisocyanate (H12MDI),
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),
1,6-diisocyanatohexane (HDI), tetramethyl-m-xylylene diisocyanate,
a mixture of 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexame
(TMXDI), trans-1,4-hydrogenated xylylene diisocyanates (H6XDI), or
combinations thereof.
[0288] Embodiment 89 is the method of any of embodiments 62 to 88,
wherein the isocyanate comprises IPDI.
[0289] Embodiment 90 is the method of any of embodiments 62 to 89,
wherein the polycarbonate diol has a molecular weight of 450 grams
per mole (g/mol) to 3,200 g/mol, or 1,800 g/mol to 3,200 g/mol.
[0290] Embodiment 91 is the method of any of embodiments 62 to 91,
wherein the polycarbonate diol has a molecular weight of 800 g/mol
to 2,200 g/mol, or 1,800 g/mol to 2,200 g/mol.
[0291] Embodiment 92 is the method of any of embodiments 62 to 91,
wherein the photopolymerizable composition has a solids content of
95% to 100% solids.
[0292] Embodiment 93 is the method of any of embodiments 62 to 92,
wherein the photopolymerizable composition has a solids content of
100% solids.
[0293] Embodiment 94 is the method of any of embodiments 62 to 93,
wherein the photopolymerizable composition further comprises a UV
absorber comprising an optical brightener in an amount of 0.001 to
5% by weight, based on the total weight of the photopolymerizable
composition.
[0294] Embodiment 95 is the method of embodiment 94, wherein the
optical brightener includes a compound of Formula (V):
##STR00010##
[0295] Embodiment 96 is the method of any of embodiments 62 to 95,
wherein the photopolymerizable composition further includes an
inhibitor in an amount of 0.001 to 1 wt. %, based on the total
weight of the photopolymerizable composition.
[0296] Embodiment 97 is the method of any of embodiments 62 to 96,
wherein the photoinitiator is present in an amount of 0.2 to 5 wt.
%, based on the total weight of the photopolymerizable
composition.
[0297] Embodiment 98 is the method of any of embodiments 62 to 97,
wherein the catalyst contains zinc.
[0298] Embodiment 99 is the method of any of embodiments 62 to 98,
wherein the catalyst includes an organometallic zinc complex and is
free of 2-ethylhexyl carboxylate and 2-ethylhexanoic acid.
[0299] Embodiment 100 is the method of any of embodiments 62 to 99,
wherein the catalyst is free of tin.
[0300] Embodiment 101 is the method of any of embodiments 62 to
100, wherein the catalyst contains bismuth.
[0301] Embodiment 102 is the method of any of embodiments 62 to
101, wherein the polyurethane (meth)acrylate polymer has a weight
average molecular weight of 6,000 g/mol to 35,000 g/mol.
[0302] Embodiment 103 is the method of any of embodiments 62 to
102, wherein the photopolymerizable composition further includes a
difunctional monomer in an amount of up to 15 wt. %, based on the
total weight of the photopolymerizable composition.
[0303] Embodiment 104 is the method of embodiment 103, wherein the
difunctional monomer includes a compound of Formula (X):
H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)X-Q-O--C(.dbd.O)NH--R.sub.di-NHC(.dbd.O)--
-O-Q-XC(.dbd.O)(R.sub.3).dbd.CH.sub.2 (X), wherein R.sub.d, is the
residue of a diisocyanate and R.sub.3 is as defined for Formula
(II).
[0304] Embodiment 105 is the method of embodiment 103, wherein the
difunctional monomer includes a compound of Formula (XI):
H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--O-Q-NH--C(.dbd.O)--(O--R.sub.1--O--C(.d-
bd.O)).sub.m--O--R.sub.2--O--C(.dbd.O)NH-Q-O--C(.dbd.O)C(R.sub.3).dbd.CH.s-
ub.2 (XI) wherein Q and R.sub.3 are as defined for Formula (II) and
R.sub.1 and R.sub.2 are as defined for Formula (I).
[0305] Embodiment 106 is the method of any of embodiments 62 to
105, wherein a ratio of the isocyanate to the polycarbonate diol
ranges from 4 molar equivalents of the isocyanate to 1 molar
equivalent of the alcohol of the polycarbonate diol, to 4 molar
equivalents of the isocyanate to 3 molar equivalents of the alcohol
of the polycarbonate diol.
[0306] Embodiment 107 is the method of embodiment 106, wherein the
ratio of the isocyanate to the polycarbonate diol is 4 molar
equivalents of isocyanate to 2 molar equivalents of the alcohol of
the polycarbonate diol.
[0307] Embodiment 108 is the method of any of embodiments 62 to
107, wherein a ratio of the isocyanate to the (meth)acrylate
mono-ol ranges from 4 molar equivalents of the isocyanate to 3
molar equivalents of the (meth)acrylate mono-ol to 4 molar
equivalents of the isocyanate to 1 molar equivalent of the
(meth)acrylate mono-ol.
[0308] Embodiment 109 is the method of any of embodiments 62 to
108, wherein a ratio of the isocyanate to the (meth)acrylate
mono-ol is 4 molar equivalents of the isocyanate to 2 molar
equivalents of the (meth)acrylate mono-ol.
[0309] Embodiment 110 is the method of any of embodiments 62 to
109, wherein a ratio of the polycarbonate diol to the
(meth)acrylate mono-ol ranges from 1 molar equivalent of the
alcohol of the polycarbonate diol to 3 molar equivalents of the
(meth)acrylate mono-ol, to 3 molar equivalents of the alcohol of
the polycarbonate diol to 1 molar equivalents of the (meth)acrylate
mono-ol.
[0310] Embodiment 111 is the method of any of embodiments 62 to
110, wherein a ratio of the polycarbonate diol to the
(meth)acrylate mono-ol is 1 molar equivalent of the alcohol of the
polycarbonate diol to 1 molar equivalent of the (meth)acrylate
mono-ol.
[0311] Embodiment 112 is the method of any of embodiments 62 to
111, wherein the polyurethane (meth)acrylate is of Formula
(VI):
(A).sub.p-Q-OC(O)NH--R.sub.dh--NH--C(O)--[O--R.sub.dOH--OC(O)NH--R.sub.d-
h--NH--C(O)].sub.r--O-Q-(A).sub.p (VI)
[0312] wherein, A has the formula
--OC(.dbd.O)C(R.sub.3).dbd.CH.sub.2 wherein R.sub.3 is an alkyl of
1 to 4 carbon atoms (e.g. methyl) or H, p is 1 or 2, Q is a
polyvalent organic linking group as described above, Rai is the
residue of a diisocyanate, R.sub.dOH is the residue of a
polycarbonate polyol, and r averages from 1 to 15.
[0313] Embodiment 113 is the method of any of embodiments 62 to
112, the photopolymerizable composition further includes a second
polymerization reaction product of components. The components
include 1) an isocyanate functional (meth)acrylate compound of the
Formula (VII): (A).sub.p-Q-NCO (VII), wherein A, p, and Q are as
defined for Formula (II); 2) a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 3) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23.
[0314] Embodiment 114 is the method of embodiment 113, wherein the
second polymerization reaction product includes a compound of
Formula (VIII):
(H.sub.2C.dbd.C(R.sub.3)C(.dbd.O)--O).sub.p--O-Q-NH--C(.dbd.O)--(O--R.su-
b.1--O--C(.dbd.O)).sub.m--O--R.sub.2--O--C(.dbd.O)NH-Q-(O--C(.dbd.O)(R.sub-
.3)C.dbd.CH.sub.2).sub.p (VIII).
Q, p, and R.sub.3 are as defined for Formula (II) and R.sub.1 and
R.sub.2 are as defined for Formula (I).
[0315] Embodiment 115 is the method of embodiment 114, wherein the
compound of Formula (VIII) is a compound of Formula (IX):
##STR00011##
[0316] wherein n is about 6.7 for a 1000 molecular weight
polycarbonate diol based on hexane diol.
[0317] Embodiment 116 is the method of any of embodiments 62 to
115, wherein a cured homopolymer of the monofunctional
(meth)acrylate monomer has a T.sub.g of 100.degree. C. or
greater.
[0318] Embodiment 117 is the method of any of embodiments 62 to
116, wherein the cured homopolymer of the monofunctional
(meth)acrylate monomer has a T.sub.g of 170.degree. C. or greater
or 180.degree. C. or greater.
[0319] Embodiment 118 is the method of any of embodiments 62 to
117, wherein the monofunctional acrylate monomer includes a
cycloaliphatic monofunctional (meth)acrylate.
[0320] Embodiment 119 is the method of any of embodiments 62 to
118, wherein the monofunctional acrylate monomer includes isobornyl
methacrylate.
[0321] Embodiment 120 is the method of any of embodiments 62 to
119, wherein the orthodontic article exhibits an initial relaxation
modulus of 100 megapascals (MPa) or greater measured at 2% strain
at 37.degree. C.
[0322] Embodiment 121 is the method of any of embodiments 62 to
120, wherein the orthodontic article exhibits a percent loss of
relaxation modulus of 70% or less.
[0323] Embodiment 122 is the method of any of claims 62 to 121,
wherein the orthodontic article exhibits a percent loss of
relaxation modulus of 40% or less.
[0324] Embodiment 123 is the method of any of embodiments 62 to
122, wherein the orthodontic article exhibits a relaxation modulus
of 100 MPa or greater.
[0325] Embodiment 124 is the method of any of embodiments 62 to
123, wherein the orthodontic article exhibits an elongation at
break of a printed article of 20% or greater.
[0326] Embodiment 125 is the method of any of embodiments 62 to
124, wherein the orthodontic article exhibits an elongation at
break of a printed article of 70% or greater.
[0327] Embodiment 126 is the method of any of embodiments 62 to
125, wherein the orthodontic article exhibits a tensile strength at
yield of 14 MPa or greater.
[0328] Embodiment 127 is the method of any of embodiments 62 to
126, wherein the orthodontic article exhibits a tensile strength at
yield of 25 MPa or greater
[0329] Embodiment 128 is the method of any of embodiments 62 to
127, wherein the orthodontic article contains 1 wt. % or less
extractable components.
[0330] Embodiment 129 is the method of any of embodiments 62 to
128, wherein the orthodontic article exhibits a peak in loss
modulus of 20.degree. C. or less.
[0331] Embodiment 130 is the method of embodiment 129, exhibiting a
tan delta peak of 80.degree. C. or greater.
[0332] Embodiment 131 is the method of any of embodiments 62 to
130, wherein the orthodontic article includes a dental tray, a
retainer, or an aligner.
[0333] Embodiment 132 is the method of any of embodiments 62 to
131, wherein the orthodontic article includes an aligner.
[0334] Embodiment 133 is a compound of Formula (V):
##STR00012##
[0335] Embodiment 134 is an orthodontic article including a
polymerized reaction product of a photopolymerizable composition.
The photopolymerizable composition includes i) a monofunctional
(meth)acrylate monomer whose cured homopolymer has a T.sub.g of
90.degree. C. or greater; ii) a photoinitiator; iii) a UV absorber
comprising a compound of Formula (V)
##STR00013##
and iv) a polymerization reaction product of components. The
components include 1) an isocyanate; 2) a (meth)acrylate mono-ol;
3) a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0336] Embodiment 135 is a method of making an orthodontic article,
the method including a) obtaining a photopolymerizable composition;
b) selectively curing the photopolymerizable composition; and c)
repeating steps a) and b) to form multiple layers and create the
orthodontic article. The photopolymerizable composition includes i)
a monofunctional (meth)acrylate monomer whose cured homopolymer has
a T.sub.g of 90.degree. C. or greater; ii) a photoinitiator; iii) a
UV absorber comprising a compound of Formula (V)
##STR00014##
and iv) a polymerization reaction product of components. The
components include 1) an isocyanate; 2) a (meth)acrylate mono-ol;
3) a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.mO--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0337] Embodiment 136 is a non-transitory machine readable medium
comprising data representing a three-dimensional model of an
orthodontic article, when accessed by one or more processors
interfacing with a 3D printer, causes the 3D printer to create an
orthodontic article comprising a reaction product of a
photopolymerizable composition. The photopolymerizable composition
includes i) a monofunctional (meth)acrylate monomer whose cured
homopolymer has a T.sub.g of 90.degree. C. or greater; ii) a
photoinitiator; and iii) a polymerization reaction product of
components. The components include 1) an isocyanate; 2) a
(meth)acrylate mono-ol; 3) a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average of carbon atoms in a combination of all the R.sub.1 and
R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0338] Embodiment 137 is a method including a) retrieving, from a
non-transitory machine readable medium, data representing a 3D
model of an article; b) executing, by one or more processors, a 3D
printing application interfacing with a manufacturing device using
the data; and c) generating, by the manufacturing device, a
physical object of the orthodontic article. The orthodontic article
includes a reaction product of a photopolymerizable composition.
The photopolymerizable composition includes i) a monofunctional
(meth)acrylate monomer whose cured homopolymer has a T.sub.g of
90.degree. C. or greater; ii) a photoinitiator; and iii) a
polymerization reaction product of components. The components
include 1) an isocyanate; 2) a (meth)acrylate mono-ol; 3) a
polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0339] Embodiment 138 is a method including a) receiving, by a
manufacturing device having one or more processors, a digital
object comprising data specifying a plurality of layers of an
orthodontic article; and b) generating, with the manufacturing
device by an additive manufacturing process, the orthodontic
article based on the digital object. The orthodontic article
includes a reaction product of a photopolymerizable composition.
The photopolymerizable composition includes i) a monofunctional
(meth)acrylate monomer whose cured homopolymer has a T.sub.g of
90.degree. C. or greater; ii) a photoinitiator; and iii) a
polymerization reaction product of components. The components
include 1) an isocyanate; 2) a (meth)acrylate mono-ol; 3) a
polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0340] Embodiment 139 is a system including a) a display that
displays a 3D model of an orthodontic article; and b) one or more
processors that, in response to the 3D model selected by a user,
cause a 3D printer to create a physical object of an orthodontic
article. The orthodontic article includes a reaction product of a
photopolymerizable composition. The photopolymerizable composition
includes i) a monofunctional (meth)acrylate monomer whose cured
homopolymer has a T.sub.g of 90.degree. C. or greater; ii) a
photoinitiator; and iii) a polymerization reaction product of
components. The components include 1) an isocyanate; 2) a
(meth)acrylate mono-ol; 3) a polycarbonate diol of Formula (I):
H(O--R.sub.1--O--C(.dbd.O)).sub.m--O--R.sub.2--OH (I); and 4) a
catalyst. Each of R.sub.1 in each (O--R.sub.1--O--C(.dbd.O)) repeat
unit and each R.sub.2 are independently an aliphatic,
cycloaliphatic, or aliphatic/cycloaliphatic alkylene group and an
average number of carbon atoms in a combination of all the R.sub.1
and R.sub.2 groups is 4 to 10, and m is 2 to 23. The polymerized
reaction product of the photopolymerizable composition has a shape
of the orthodontic article.
[0341] Embodiment 140 is the article of any of embodiments 1 to 61,
wherein the photopolymerizable composition comprises at least one
hydrophilic monomer or polymer having a log P of less than 3,
present in an amount of 1% to 25% by weight, based on the total
weight of the photopolymerizable composition.
[0342] Embodiment 141 is the article of embodiment 140, wherein the
photopolymerizable composition comprises at least one
monofunctional (meth)acrylate monomer whose homopolymer has a
T.sub.g of 150.degree. C. or greater in an amount of 20% by weight
or greater, based on the total weight of the photopolymerizable
composition.
[0343] Embodiment 142 is the method of any of embodiments 62 to
131, wherein the photopolymerizable composition comprises at least
one hydrophilic monomer or polymer having a log P of less than 3,
present in an amount of 1% to 25% by weight, based on the total
weight of the photopolymerizable composition.
[0344] Embodiment 143 is the method of embodiment 142, wherein the
photopolymerizable composition comprises at least one
monofunctional (meth)acrylate monomer whose homopolymer has a
T.sub.g of 150.degree. C. or greater in an amount of 20% by weight
or greater, based on the total weight of the photopolymerizable
composition.
EXAMPLES
[0345] Objects and advantages of this disclosure are further
illustrated by the following examples, but the particular materials
and amounts thereof recited in these examples, as well as other
conditions and details, should not be construed to unduly limit
this disclosure.
Materials
[0346] Unless otherwise noted, all parts, percentages, ratios, etc.
in the examples and the rest of the specification are by weight.
The Materials Table (below) lists materials used in the examples
and their sources.
TABLE-US-00002 Materials Table Material designation Description
1-Adamantanol Obtained from TCI America, Portland, OR. 212-20 A
polycarbonate diol of about 1500 MW made with CO.sub.2 and
propylene oxide obtained as "CONVERGE POLYOL 212-20" from Aramco,
Dhahran, Saudi Arabia. 4-chloro-1,8- Obtained from Alfa Aesar,
Haverhill, MA. naphthalic anhydride 4-hydroxy-TEMPO
4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, obtained from Sigma
Aldrich, St. Louis, MO. 4-tert- 4-tert-butylcyclohexanol, mixture
of isomers, obtained from TCI butylcyclohexanol America, Portland,
OR. Acetonitrile Omnisolv HPLC grade obtained from EMD Millipore, a
part of Merck KGaA, Darmstadt, Germany. Acrylic acid Obtained from
Alfa Aesar, Haverill, MA. Acryloyl chloride Obtained from
Sigma-Aldrich Chemical Company, St. Louis, MO. Ammonium formate
Obtained as a 5 M aqueous solution from Agilent Technologies,
Waldbronn, Germany. Anhydrous Obtained from EMD Millipore, a part
of Merck KGaA. magnesium sulfate BHT 2,6-di-t-butyl-4-methylphenol
obtained from Alfa Aesar, Haverhill, MA. BiN Bismuth neodecanoate
obtained from Sigma-Aldrich, St. Louis, MO. C XP-2613 A
polycarbonate diol of about 2000 MW of what is believed to have
about a 75:25 mole ratio of butane diol:hexane diol, obtained as
"DESMOPHEN C XP-2613" from Covestro LLC., Leverkusen, Germany.
C-1090 A polycarbonate diol of about 1000 MW made with about a 9:1
mole ratio of 3-methyl-1,5-pentanediol (MPD): hexane diol (HD),
(i.e., 90% MPD,) obtained as "KURARAY POLYOL C-1090" from Kuraray
Co. Ltd., Tokyo, Japan. C-2050 A polycarbonate diol of about 2000
MW made with about a 50% (i.e., 5:5) mole ratio of (MPD): (HD),
obtained as "KURARAY POLYOL C- 2050" from Kuraray Co. Ltd. C-2090 A
polycarbonate diol of about 2000 MW made with about a 9:1 mole
ratio of (MPD): (HD), obtained as "KURARAY POLYOL C-2090" from
Kuraray Co. Ltd. C-2100 A polycarbonate diol of about 1000 MW that
it is believed uses HD as the diol, obtained as "DESMOPHEN C-2100"
from Covestro LLC. C-2200 A polycarbonate diol of about 2000 MW
that it is believed uses HD as the diol, obtained as "DESMOPHEN
C-2200" from Covestro LLC. C-3090 A polycarbonate diol of about
3000 MW made with about a 9:1 mole ratio of (MPD): (HD), obtained
as "KURARAY POLYOL C-3090" from Kuraray Co. Ltd. C-590 A
polycarbonate diol of about 500 MW made with about a 9:1 mole ratio
of (MPD): (HD) obtained as "KURARAY POLYOL C-590" from Kuraray Co.
Ltd. CEA 2-Carboxyethyl acrylate, obtained from Sigma-Aldrich, St.
Louis, MO. Chloroform Obtained from EMD Millipore, a part of Merck
KGaA, Darmstadt, Germany. CHMA Cyclohexyl methacrylate, obtained
from Alfa Aesar, Haverhill, MA. DBTDL Dibutyltin diacrylate,
obtained from Sigma-Aldrich, St. Louis, MO. DDDMA 1,12-dodecanediol
dimethacrylate obtained as "SR262" from Sartomer, Exton, PA.
Desmodur I (IPDI) Isophorone diisocyanate, under trade designation
"DESMODUR I" equivalent weight 111.11, molecular weight 222.22
g/mole, from Covestro LLC. Desmodur W Hydrogenated methylene
diisocyanate, under trade designation (H12MDI) "DESMODUR W",
equivalent weight 131.25, molecular weight 262.5 g/mole, from
Covestro LLC. DiCPMA Dicyclopentanyl methacrylate Obtained from TCI
America, Portland, OR. DMAP 4-dimethylaminopyridine, obtained from
Alfa Aesar, Haverhill, MA. EHMA 2-Ethyl hexyl methacrylate,
obtained from Alfa Aesar. Ethanol Obtained from Spectrum Chemicals,
New Brunswick, NJ. Ethanolamine Obtained from Sigma Aldrich. Ethyl
acetate Obtained from EMD Millipore, a part of Merck KGaA.
Exothane-10 A urethane (meth)acrylate oligomer comprising a
polyethylene oxide diol of about 400 MW, obtained as "EXOTHANE-10"
from Esstech Inc., Essington, PA. Exothane-108 A urethane
(meth)acrylate oligomer comprising a polytetramethylene oxide diol
of about 650 MW, obtained as "EXOTHANE-108" from Esstech Inc.
G-AC-MAC Glycerol acrylate methacrylate (
1-(acryloyloxy)-3-(methacryloyloxy)-2- propanol, CAS 1709-71-3),
obtained from TCI America, Portland, OR. HCl Hydrochloric acid,
obtained from Sigma Aldrich. HDDMA 1,6-Hexanediol dimethacrylate
(SR239), obtained from Sartomer. HDI 1,6-diisocyanatohexane,
equivalent weight 84.1, molecular weight 168.2, available under
trade designation "DESMODUR H", from Covestro LLC. HEA Hydroxyethyl
acrylate, obtained from Alfa Aesar. HEMA Hydroxyethyl methacrylate,
obtained from TCI America, Portland, OR. Heptane Heptane (Ultra
resi-analyzed) was obtained from Avantor, Center Valley, PA.
Hydroquinone Obtained from Alfa Aesar. IBOA Isobornyl acrylate,
obtained from Alfa Aesar. IBOMA Isobornyl methacrylate obtained as
"SR423A" from Sartomer. IEM Isocyanatoethyl methacrylate, MW
155.15, available under the trade designation "KARENZ MOI," from
Showa Denko. IEM-EO Isocyanatoethoxyethyl methacrylate, MW 199.2,
available under the trade designation "KARENZ MOI-EG," from Showa
Denko. iPrOH Isopropyl alcohol, obtained from EMD Millipore, a part
of Merck KGaA. KOH Potassium hydroxide, obtained from Sigma
Aldrich. MDI Product trade designation "MONDUR MLQ," an approximate
80:20 mixture of 4,4' and 2,4' diphenylmethane diisocyanate,
equivalent weight 125.125, molecular weight 250.25, from Covestro
LLC. MeOH Methanol, obtained from EMD Millipore, a part of Merck
KGaA. Methacrylic acid Obtained from Sigma Aldrich. Methacrylic
Obtained from Sigma Aldrich. anhydride Na.sub.2CO.sub.3 Sodium
Carbonate, obtained from Sigma Aldrich. NL2030B A polycarbonate
diol of about 2000 MW made with about a 3:7 mole ratio of neopentyl
glycol:butane diol, obtained as "NL2030B" from Mitsubishi Chemical
Company, Tokyo, JP. NL2005B A polycarbonate diol of about 2000 MW
made with about a 5:95 mole ratio of neopentyl glycol:butane diol,
obtained as "NL2005B" from Mitsubishi Chemical Company. NL2010DB A
polycarbonate diol of about 2000 MW made with about a 10:90 mole
ratio of 1,10-decane diol:butane diol, obtained as "NL2010B" from
Mitsubishi Chemical Company. NVP 1-vinyl-2-pyrolidone, obtained
from TCI Chemicals, Portland, OR. Omnirad 379
2-Dimethylamino-2-(4-methyl-benzy1)-1-(4-morpholin-4-yl-pheny1)-
butan-1-one, photoinitiator, obtained from IGM Resins, Charlotte,
NC. P-1020 A 3-methyl-1,5-pentane diol terephthalate diol of about
1000 MW obtained as "KURARAY POLYOL P-1020" from Kuraray. PBS
Phosphate buffered saline (PBS, 10X), pH =7.4, obtained from Alfa
Aesar. PEG600DMA Polyethylene glycol 600 dimethacrylate, obtained
from Sartomer. PEMA 2-Phenoxy ethyl methacrylate ("SR340"),
obtained from Sartomer. Petroleum ether Obtained from EMD
Millipore, a part of Merck KGaA. Phenothiazine Obtained from TCI
America. Propylene Obtained from Alfa Aesar. Carbonate PTMO-2000 A
poly(tetramethylene oxide) diol of about 2000 MW, obtained as
"POLYTHF 1000" polyether from BASF, Florham Park, NJ.
p-toluenesulfonic Obtained from TCI, America. acid Sodium
bicarbonate Obtained from EMD Millipore, a part of Merck KGaA.
Sulfuric acid Obtained from EMD Millipore, a part of Merck KGaA.
Tetrahydrofuran Omnisolv HPLC grade from EMD Millipore, a part of
Merck KGaA. THFMA Tetrahydrofurfuryl methacrylate, obtained from
Sartomer. Tinuvin 326 Phenol,
2-(5-chloro-2H-benzotriazol-2-y1)-6-(1,1-dimethylethyl)-4- methyl,
UV-absorber, obtained from BASF. TMXDI
1,3-Bis(1-isocyanato-1-methylethyl)benzene, equivalent weight
122.15, molecular weight 244.3, from Sigma-Aldrich. TPO
2,4,6-trimethylbenzoyldiphenylphosphine oxide photoinitiator
obtained as "IRGACURE TPO" from BASF. Triethylamine Obtained from
EMD Millipore, a part of Merck KGaA. TMCHMA
3,3,5-trimethylcylohexanemethacrylate, obtained from Sartomer.
XK-672 Zn based catalyst obtained as "K-KAT XK-672" from King
Industries, Norwalk, CT.
Preparatory Examples
Preparation of Naphthalimide Acrylate (NapA)
##STR00015## ##STR00016##
[0348] To a 1 L three-neck round-bottom flask was added
4-chloronaphthalic anhydride (100.0 g, 0.4299 moles, 1.0 equiv.),
ethanolamine (26.26 g, 0.4299 moles, 1.0 equiv.), and iPrOH (516.7
g). The flask was outfitted with a temperature probe, overhead
stirrer, and reflux condenser. The reaction mixture was heated to
80.degree. C. with stirring for 6 hours, then cooled to 10.degree.
C. with an ice bath. The resulting yellow solid was collected via
filtration and stirred with a mixture of water (300 g), iPrOH (300
g), and concentrated HCl (10 g). The resulting solid was filtered
and washed with water/iPrOH (1:1, 500 g) and allowed to air dry.
This afforded alcohol 2 (102 g, 86%).
##STR00017##
[0349] To a 2 L three-neck round-bottom flask was added alcohol 2
(100.0 g, 0.3627 moles, 1.0 equiv.), KOH (40.71 g, 0.7255 moles,
2.0 equiv.), and methanol (581 g). The flask was outfitted with a
temperature probe, overhead stirrer, and reflux condenser. The
reaction mixture was heated to 65.degree. C. with stirring for 36
hours, then cooled to 10.degree. C. with an ice bath. The resulting
yellow solid was collected via filtration and stirred with a
mixture of water (300 g), MeOH (300 g), and concentrated HCl (10
g). The resulting solid was filtered and washed with water/MeOH
(1:1, 600 g) and allowed to air dry. This afforded alcohol 3 (86.5
g, 88%).
##STR00018##
[0350] To a 1 L 3-neck round-bottom flask was added alcohol 3
(80.00 g, 0.2949 moles, 1.0 equiv.), chloroform (704 g), and
triethylamine (35.81 g, 0.3539 moles, 1.2 equiv.). The flask was
outfitted with a Claisen adapter, overhead stirrer, and a
pressure-equalizing addition funnel. The Claisen adapter was
outfitted with a temperature probe and a reflux condenser. The
reaction mixture was stirred and heated to 40.degree. C. Acryloyl
chloride (29.36 g, 0.3244 moles, 1.1 equiv.) was added dropwise via
the addition funnel such that the reaction temperature did not rise
above 45.degree. C. After addition was complete, the reaction was
stirred for 30 minutes. Triethylamine (6.00 g, 0.0593 moles, 0.2
equiv.) was added, followed by acryloyl chloride (5.00 g, 0.0552
moles, 0.19 equiv.) dropwise. The reaction was stirred for an
additional 30 minutes at 40.degree. C. Next, the reaction flask was
outfitted with a distillation head, condenser, and receiving flask.
The reaction mixture was heated to strip most of the chloroform.
EtOH (500 g) was added, and the strip continued until the
distillation head temperature reached 78.degree. C. The reaction
mixture was cooled to 10.degree. C. with an ice bath and filtered.
The resulting solid was washed with water/HCl (10:1, 500 mL),
water/Na.sub.2CO.sub.3 (10:1, 500 mL), and water/EtOH (1:1, 500
mL). The solid was allowed to dry to afford the product 4 as a pale
yellow solid (92.5 g, 96%).
Preparation of Adamantyl-1-methacrylate (AdMA)
[0351] A 2 L, 3 neck round-bottom flask was fitted with a
dean-stark trap with a condenser, magnetic stir bar, and a
thermometer. 1-Adamantanol (252 g 1.650 mol), hydroquinone (0.3 g),
methacrylic acid (455 g, 5.28 mmol), and methylcyclohexane (400 g)
were added and the mixture was stirred. Sulfuric acid (10.5 g) was
then added to the mixture, and then dry air was slowly bubbled into
the mixture. The mixture was heated to reflux under constant
bubbling of air for 26 hours, during which time the reaction
product water was removed using the trap. The mixture was then
cooled to room temperature, and slowly added to a mechanically
stirred, ice-bath cooled mixture of 350 g KOH (6.2 mol) in 1000 g
of deionized water and 500 g hexanes. After the addition was
complete, the resulting mixture was separated using a separatory
funnel, and extracted 1.times.500 mL hexanes. The combined organic
extracts were washed with a saturated aqueous sodium bicarbonate
solution, and then 20 mg of phenothiazine was added to the organic
phase. This was then dried over anhydrous magnesium sulfate,
filtered, and concentrated by rotary evaporation. The concentrate
was then distilled under vacuum (BP=87-90.degree. C., 0.3 torr),
where the receiver flask contained 15 mg of 4-hydroxy-TEMPO, and
320 g of liquid was obtained. BHT (48 mg) was then added and dry
air was bubbled into the clear product for 30 seconds before
storage. .sup.1H NMR: 5.99 (m, 1H), 5.45 (m, 1H), 2.14 (m, 9H),
1.87 (m, 3H), 1.64 (m, 6H). .sup.13C NMR: 168.5, 138.1, 124.3,
80.4, 41.3, 36.3, 30.9, 18.4. Purity by GC=98.4%.
[0352] Characterization of the Above Material by Nuclear Magnetic
Resonance (NMR) Spectroscopy
[0353] An Ultrashield 500 Plus FT NMR instrument from Bruker
(Billerica, Mass.) was used to acquire .sup.1H NMR (500 MHz) and
.sup.13C NMR (125 MHz) spectra. Chemical shifts (6) are reported in
ppm relative to CDCl.sub.3. Abbreviations for splitting patterns
are as follows; s (singlet); d (doublet); t (triplet); q (quartet);
m (multiplet); br (broad); app (apparent) and combinations of these
abbreviations.
Preparation of 4-tert-butylcyclohexyl methacrylate (mixture
cis/trans) (tBuCHMA)
[0354] A 2 L, 3 neck round-bottom flask was fitted with a 250 mL
addition funnel, magnetic stir bar, and a thermometer.
4-tertbutylcyclohexanol (150 g, 960 mmol), dichloromethane (600 g),
triethylamine (178 g, 1760 mmol), and DMAP (6.4 g, 52 mmol) were
added to the flask, and then methacrylic anhydride (263 g, 1710
mmol) was added dropwise keeping the temperature below 35.degree.
C. This mixture was stirred at room temperature for 24 hours, and
then 150 mL water was added and stirred overnight. Dichloromethane
(500 g) was then added, and the organic phase was washed with 200
mL water, 200 mL of 0.1 M HCl, and 200 mL saturated sodium
bicarbonate. The organic phase was dried over anhydrous magnesium
sulfate and 20 mg phenothiazine was added. This was filtered and
concentrated by rotary evaporation. The concentrate was then
distilled under vacuum (BP=73-90.degree. C., 0.3 torr), where the
receiver flask contained 7 mg of 4-hydroxy-TEMPO, and 170 g of
liquid was obtained. BHT (26 mg) was then added and dry air was
bubbled into the clear product for 30 seconds before storage.
.sup.1H NMR was consistent with a mixture of 72% trans and 28% cis
isomer as described in Macromolecules, 1993, 26, 1659-1665. GC
analysis showed a total of 96% of the two isomers with a ratio of
73% trans/27% cis.
[0355] Characterization of the Above Material by Gas Chromatography
(GC)
[0356] Sample purity and product ratios were determined by gas
chromatography (GC) and was performed using a Hewlett Packard (Palo
Alto, Calif.) 6890 Series Plus gas chromatograph with a flame
ionization detector and HP G1530A digital integrator. Sample
injection was done with a 7683 series injector in conjunction with
an injection volume of 2 microliters, injection port at a
temperature of 250.degree. C., and a split ratio of 20:1. A 30
m.times.0.53 mm.times.5 micrometer column obtained under the trade
designation "RESTEX RTX-1" from Restek Corp. (Bellefonte, Pa.) was
utilized with a flow rate of 12.4 mL/min He as the carrier gas with
a temperature program of 50.degree. C. to 230.degree. C. at
15.degree. C./min; 230.degree. C. to 280.degree. C. at 50.degree.
C./min; then hold at 280.degree. C. for 2 min.
Preparation of diol diacrylates
Preparation of C-590 diol diacrylate
##STR00019##
[0358] C-590 diol (50 g, 90.79 mmol;) and acrylic acid (19.8 g, 275
mmol,) and p-toluenesulfonic acid (1.96 g, 11.3 mmol,) were charged
into a 250 mL 3-neck flask equipped with a magnetic stirring bar, a
thermocouple and a condenser. The mixture was heated at 85.degree.
C. Vacuum (15-20 torr) was applied for 2 minutes every 15-20
minutes in order to remove any formed water from the reaction. This
was repeated for 4 hours at which time there were no signs of
H.sub.2O forming or condensing on the flask walls. The heat was
turned off. After cooling to room temperature, the mixture was
dissolved in a 130 mL ethyl acetate/petroleum ether mixture (10:3
ratio). The mixture was extracted with 10% aqueous NaOH (100 mL)
then H.sub.2O (200 mL). The organic layer was dried (over
Na.sub.2SO.sub.4), then concentrated to give a clear liquid with
91% yield.
Preparation of C-590 diol dimethacrylate (C-590 diol MA)
##STR00020##
[0360] This material was prepared following the procedure described
above for preparation of C-590 diol diacrylate, except that
methacrylic acid was used instead of acrylic acid. The product was
isolated as a low viscosity liquid in 88-93% yield.
Preparation of C-2050 diol dimethacrylate (C-2050 diol MA)
##STR00021##
[0362] This material was prepared following the procedure described
above for preparation of C-590 diol diacrylate, except that
methacrylic acid was used instead of acrylic acid and C-2050 diol
was used instead of C-590 diol.
Preparation of Polycarbonate Diol Based Urethane
(Meth)acrylates
[0363] The urethane acrylates are of three main types: [0364] 1)
Polycarbonate diols reacted with diisocyanates capped with
(meth)acrylate mono-ols such as HEA and HEMA. Below is an idealized
structure of such a material, illustrated with a hexane diol based
polycarbonate diol:
[0364] ##STR00022## [0365] 2) Polycarbonate diols capped with
isocyanate-(meth)acrylates, illustrated with a hexane diol based
polycarbonate diol and IEM:
[0365] ##STR00023## [0366] 3) Diisocyanates capped with
(meth)acrylate mono-ols:
##STR00024##
[0367] Type 1: 4 IPDI/2 C-2050/2 HEMA (PE-1)
[0368] A 1 L three-necked round-bottom flask was charged with
514.75 g C-2050 (0.52285 eq, 984.5 hydroxide equivalent weight (OH
EW)), heated to about 45.degree. C., then were added 116.19 g IPDI
(1.0457 eq), 0.280 g BHT (400 ppm), and 0.175 DBTDL (250 ppm). The
reaction was heated under dry air to an internal setpoint of
105.degree. C. (temperature reached at about 20 min). At 1 hour and
20 minutes 69.06 g HEMA (0.5307 eq, 130.14 MW, a 1.5% excess) was
added via an addition funnel at a steady rate over 1 hour and 10
minutes. The reaction was heated for about 2.5 hours at 105.degree.
C., then an aliquot was checked by Fourier transform infrared
spectroscopy (FTIR) and found to have no -NCO peak at 2265 cm.sup.1
and the product was isolated as a clear, viscous material.
[0369] Type 2: C-2050/2 IEM (PE-2)
[0370] A 1 L three-necked round-bottom flask was charged with
431.93 g C-2050 (0.43873 eq, 984.5 OH EW), 0.200 g BHT (400 ppm),
and 0.125 g DBTDL (250 ppm) and heated to an internal temperature
of about 60.degree. C. under dry air. Then 68.07 g IEM (0.43873 eq,
155.15 MW) was added via an addition funnel over about 1 hour and
20 minutes. At 1 hour and 30 minutes an aliquot was checked by FTIR
and found to have no -NCO peak at 2265 cm.sup.-1. At 1 hour and 38
minutes 1.32 g more IEM was added, and an aliquot was checked by
FTIR and found to have no -NCO peak at 2265 cm.sup.-1. At 4 hours
into the reaction, the reaction was stopped and the product was
isolated as a clear, viscous material.
[0371] Type 3: IPDI/HEMA (PE-3)
[0372] A 1 L three-necked round-bottom flask was charged with
319.80 g IPDI (2.878 eq), 0.280 g BHT, and 0.175 g bismuth
neodecanoate (250 ppm based on solids) and heated to an internal
temperature of about 55.degree. C. under dry air. Then 380.20 g
(2.921 eq) HEMA was added over 1 hour and 45 minutes, with the
internal temperature rising to a maximum of 90.degree. C. At 2
hours and 25 minutes an aliquot was checked by FTIR and found to
have no -NCO peak at 2265 cm.sup.-1.
[0373] The samples in Table 2 below were prepared by methods
according to those of Types 1-3 described above, using the amounts
and types of materials indicated in the table.
TABLE-US-00003 TABLE 2 Preparative Examples of Polycarbonate Diol
Based Polyurethane (Meth) Acrylates Isocyanate Diol (meth)-acrylate
mono-ol Catalyst BHT Sample Designation Type g Type g OH EW Type g
Type g g PE-4 4 IPDI/2 P-1020/2 HEMA IPDI 39.02 P-1020 87.79 500
HEMA 23.19 DBTDL 0.075 0 PE-5 4 IPDI/2 C-2050/2 HEMA IPDI 82.99
C-2050 367.68 984.2 HEMA 49.33 DBTDL 0.125 0.200 PE-6 4 H12MDI/2
C-2050/2 HEMA H12MDI 95.17 C-1090 356.94 984.2 HEMA 47.89 DBTDL
0.125 0.200 PE-7 4 IPDI/2 C-2050/2 HEMA IPDI 82.99 C-2050 367.68
984.2 HEMA 49.33 DBTDL 0.125 0.200 PE-8 4 IPDI/2 C-2020/2 HEMA IPDI
83.81 C-2020 366.37 971.42 HEMA 49.82 DBTDL 0.125 0.200 PE-9
C-2090/IEM IEM 69.63 C-2090 430.37 959 -- DBTDL 0.125 0.200 PE-10
C-2090/IEM-EO IEM-EO 86.00 C-2050 414.00 959 -- DBTDL 0.125 0.200
PE-11 C-2050/IEM IEM 18.91 C-2050 120.00 984.2 -- DBTDL 0.035 0.056
PE-12 C-2200/IEM IEM 68.86 C-2200 431.14 971.42 -- DBTDL 0.125
0.200 PE-13 4 IPDI/2 C-3090/2 HEMA IPDI 60.57 C-3090 403.43 1480.21
HEMA 36.00 DBTDL 0.125 0.200 PE-14 C-3090/IEM IEM 47.44 C-3090
452.56 1480.21 -- -- DBTDL 0.125 0.200 PE-15 C-1090/IEM IEM 117.78
C-1090 382.22 503.5 -- -- DBTDL 0.125 0.200 PE-16 C-590/IEM IEM
192.83 C-590 307.17 247.14 -- -- DBTDL 0.125 0.200 PE-17 4 IPDI/2
212-20/2 HEMA IPDI 98.96 212-20 342.22 768.49 HEMA 58.82 DBTDL
0.125 0.200 PE-18 4 IPDI/2 PTMO-2000/2 IPDI 82.82 PTMO-2000 367.95
997.0 HEMA 49.23 DBTDL 0.125 0.200 HEMA PE-19 4 IPDI/1.5 C-2050/2.5
HEMA IPDI 98.70 C-2050 327.96 984.2 HEMA 73.34 DBTDL 0.125 0.200
PE-20 4 IPDI/2.5 C-2050/1.5 HEMA IPDI 71.6 C-2050 396.49 984.2 HEMA
31.92 DBTDL 0.125 0.200 PE-21 4 TMXDI/2 C-2050/2 HEMA TMXDI 89.78
C-2050 361.68 984.2 HEMA 48.54 DBTDL 0.125 0.200 PE-22 4 IPDI/2
C-2050/2 HEA IPDI 117.46 C-2050 520.24 984.2 HEA 62.3 DBTDL 0.125
0.200 PE-23 4 HDI/2 C-2050/2 HEMA HDI 65.47 C-2050 383.11 984.2
HEMA 51.42 DBTDL 0.125 0.200 PE-24 4 MDI/2 C-2050/2 HEMA MDI 91.56
C-2050 360.11 984.2 HEMA 48.33 DBTDL 0.125 0.200 PE-25 4 IPDI/2
C-1090/2 HEMA IPDI 131.81 C-1090 289.85 488.67 HEMA 78.35 DBTDL
0.125 0.200 PE-26 4 IPDI/2 C-2015N/2 HEMA IPDI 83.44 C-2015N 366.97
977.35 HEMA 49.60 DBTDL 0.125 0.200 PE-27 4 IPDI/2 C-2050/2 HEMA
IPDI 117.46 C-2050 520.24 984.2 HEMA 69.82 BiN 0.177 0.283 PE-28 4
IPDI/2 XP C2613/2 HEMA IPDI 82.91 XP C2613 373.11 1000 HEMA 49.29
DBTDL 0.125 0.200 PE-29 4 IPDI/2 C 7203/2 HEMA IPDI 81.08 C 7203
370.73 1016.12 HEMA 48.19 DBTDL 0.125 0.200 PE-30 4 IPDI/1.5
C-3090/2.5 HEMA IPDI 74.20 C-3090 370.67 1480.21 HEMA 55.13 DBTDL
0.125 0.200 PE-31 4 IPDI/1 C-3090/3 HEMA IPDI 95.75 C-3090 318.88
1480.21 HEMA 85.37 DBTDL 0.125 0.200 PE-32 4 IPDI/2 C-2050/2 HEMA
IPDI 265.57 C-2050 1176.6 984.2 HEMA 157.86 BiN 0.400 0.640 PE-33
IPDI/HEMA IPDI 319.8 -- -- -- HEMA 380.20 BiN 0.175 0.280 PE-34 4
IPDI/2 C-2050/2 HEMA IPDI 83.01 C-2050 367.65 984.2 HEMA 49.34
XK-672 0.125 0.200 PE-35 4 IPDI/2 C-2050/2 HEMA IPDI 83.01 C-2050
367.65 984.2 HEMA 49.34 XK-672 0.125 0.200 PE-36 4 IPDI/2 C-2050/2
HEMA IPDI 83.01 C-2050 367.65 984.2 HEMA 49.34 XK-672 0.125 0.200
PE-37 4 IPDI/2 C-2090/2 HEMA IPDI 125.16 C-2090 550.45 977.35 HEMA
74.40 XK-672 0.125 0.200 PE-38 4 IPDI/2 C-3090/2 HEMA IPDI 90.85
C-3090 605.15 1480.21 HEMA 54.00 XK-672 0.125 0.200 PE-39 4
IPDI/2.5 C-2090/1.5 HEMA IPDI 108.02 C-2090 593.83 977.35 HEMA
48.15 XK-672 0.125 0.200 PE-40 4 IPDI/3 C-2090/1 HEMA IPDI 95.00
C-2090 626.76 977.35 HEMA 28.24 XK-672 0.125 0.200 PE-41 4 IPDI/2
C-1090/2 HEMA IPDI 117.78 C-1090 262.21 494.71 HEMA 70.01 XK-672
0.113 0.180 PE-42 4 IPDI/2.5 C-1090/1.5 HEMA IPDI 106.42 C-1090
296.14 494.71 HEMA 47.44 XK-672 0.113 0.180 PE-43 4 IPDI/3 C-1090/1
HEMA IPDI 97.06 C-1090 324.10 494.71 HEMA 28.85 XK-672 0.113 0.180
PE-44 4 IPDI/2 C-2050/2 HEMA IPDI 248.55 C-2050 1100.80 984.2 HEMA
150.65 XK-672 0.375 0.600 PE-45 4 IPDI/2 NL2030B/2 HEMA IPDI 97.35
NL2030 B 442.80 1010.8 HEMA 59.86 XK-672 0.15 0.240 PE-46 4 IPDI/2
NL2005B/2 HEMA IPDI 95.91 NL2005 B 445.11 1031.25 HEMA 58.98 XK-672
0.15 0.240 PE-47 4 IPDI/2 NL2010DB/2 HEMA IPDI 98.25 NL2010 DB
441.34 998.22 HEMA 60.41 XK-672 0.15 0.240 PE-48 H12MDI/HEMA H12MDI
310.25 HEMA 324.73 XK-672 0.159 0.254 PE-49 4 IPDI/2 C-3090/1
HEMA/1 IPDI 71.35 C-3090 470.32 1464.75 HEMA/G- 22.04/36.28 XK-672
0.159 0.254 G-AC-MAC Ac-MAC PE-50 4 IPDI/2 C-3090/2 IPDI 69.70
C-3090 459.42 1467.75 G-AC-MAC 72.49 XK-672 0.159 0.254 G-AC-MAC *
add diol over 1.5h
[0374] Determination of HEMA-IPDI-HEMA Oligomer Concentration.
[0375] Determination of a concentration of HEMA-IPDI-HEMA oligomer
was performed by liquid chromatography-mass spectrometry (LC/MS) on
an Agilent 1260 Infinity Series liquid chromatography system
(Agilent Technologies, Waldbronn, Germany) using an Agilent
Poroshell 120 SB-C82.1 mm.times.50 mm 2.7 micrometer column eluted
at 40.degree. C. with a flow rate of 0.5 mL per minute. 2
microliter samples were injected and eluted with a linear gradient
as described below. The water was Omnisolv HPLC grade from EMD
Millipore, a part of Merck KGaA. The re-equilibration time between
experiments was 5 minutes. Detection was with an Agilent 6130
Quadrupole LC/MS detector with electrospray ionization. Sample
quantification was done by integration of the chromatographic peak
detected at 500.3 m/z (M-NH.sub.4.sup.+). Mass spectrometer
parameters were in atmospheric pressure ionization-electrospray
(API-ES) mode: capillary voltage 4 kV, nebulizer gas pressure 50
psig (345 kPa gauge), drying gas flow rate 10 liters per minute,
drying gas temperature 300.degree. C.
TABLE-US-00004 TABLE 3 Solvent elution gradient Solvent Time (min)
6 mM ammonium formate in water 0 6 mM ammonium formate in 98%
acetonitrile/2% water 3 6 mM ammonium formate in 98%
acetonitrile/2% water 5 89% acetonitrile 10% tetrahydrofuran 1%
formic acid 6 89% acetonitrile 10% tetrahydrofuran 1% formic acid 8
6 mM ammonium formate in water 9
[0376] Calibration samples were prepared by dissolution of 0.1009 g
of material polyurethane acrylate PE-33 in a 100 mL volumetric
flask using ethyl acetate. This solution was then diluted 1 mL into
a 100 mL volumetric flask using acetonitrile to produce dilution 1.
Dilution 1 was further diluted to .about.2.02, 0.505, 0.101 and
0.0121 ppm concentrations in acetonitrile and filtered through 0.22
micron PTFE syringe filters (Fisher Brand, Thermo Fisher
Scientific, Hampton, N.H.). The calibration curve was linear from
2.02-0.0121 ppm. Calibrations were performed directly preceding
analytical samples.
[0377] Analytical samples were prepared by dissolution of 0.1-0.3 g
of material in a 100 mL volumetric flask using ethyl acetate. This
solution was then diluted 1 mL into a 100 mL volumetric flask using
acetonitrile to produce dilution 1. Dilution 1 was filtered through
0.22 micron PTFE syringe filters (Fisher Brand) and analyzed as
discussed above. The results for each sample are shown in Table 4
below.
TABLE-US-00005 TABLE 4 % HEMA-IDPI-HEMA in polymer (does not
IPDI:Polyol:HEMA include IBOMA Sample Polyol Catalyst eq ratio
diluent if present) PE-13 C-3090 DBTDL 4:2:2 5.0% PE-30 C-3090
DBTDL 4:1.5:2.5 11.1% PE-31 C-3090 DBTDL 4:1:3 20.7% PE-37 C-2090
XK-672 4:2:2 5.4% PE-38 C-3090 XK-672 4:2:2 3.8% PE-7 C-2050 DBTDL
4:2:2 5.6% PE-9 C-2050 DBTDL 4:2:2 5.5% PE-32 C-2050 BiN 4:2:2 5.7%
PE-25 C-1090 DBTDL 4:2:2 8.6% PE-39 C-2090 XK-672 4:2.5:1.5 3.0%
PE-40 C-2090 XK-672 4:3:1 0.3% PE-41 C-1090 XK-672 4:2:2 7.5% PE-42
C-1090 XK-672 4:2.5:1.5 1.8% PE-43 C-1090 XK-672 4:3:1 0.1% PE-44
C-2050 XK-672 4:2:2 5.0%
General Procedure for Formulation Preparation
[0378] Formulations were prepared by weighing the components
(indicated in Tables 5-17) in an amber jar, followed by rolling on
a roller (having the trade designation "OLDE MIDWAY PRO18" and
manufactured by Olde Midway) at 60.degree. C. until mixed.
TABLE-US-00006 TABLE 5 Example formulations (amounts in parts by
weight) Component EX-1 EX-2 EX-3 EX-4 EX-5 EX-6 PE-41 50 PE-42 50
PE-43 50 PE-37 50 PE-39 50 PE-40 50 IBOMA 50 50 50 50 50 50 TPO 2 2
2 2 2 2
TABLE-US-00007 TABLE 6 Example formulations (amounts in parts by
weight) EX- EX- EX- EX- EX- EX- EX- EX- Component 7 8 9 10 11 12 13
14 PE-19 50 PE-7 50 PE-22 50 PE-20 50 PE-21 50 PE-23 50 PE-24 50
PE-6 50 IBOMA 50 50 50 50 50 50 50 50 TPO 2 2 2 2 2 2 2 2 BHT
0.025
TABLE-US-00008 TABLE 7 Example formulations (amounts in parts by
weight) Component EX-15 EX-16 EX-17 EX-18 EX-19 PE-38 50 PE-31 50
PE-26 50 PE-8 50 PE-28 50 IBOMA 50 50 50 50 50 TPO 2 2 2 2 2
TABLE-US-00009 TABLE 8 Example formulations (amounts in parts by
weight) Component EX-20 EX-21 EX-22 EX-23 EX-24 EX-25 PE-25 25 18
10 15 PE-13 25 32 25 35 PE-19 25 PE-26 40 PE-30 40 PE-14 10 AdMA 50
IBOMA 50 50 50 50 50 TPO 2 2 2 2 2 2
TABLE-US-00010 TABLE 9 Example formulations (amounts in parts by
weight) Component EX-26 EX-27 EX-28 EX-29 EX-30 PE-13 45 40 PE-30
47.5 PE-32 47.5 PE-33 5 10 2.5 2.5 5 PE-11 45 IBOMA 50 50 50 50 50
TPO 2 2 2 2 2
TABLE-US-00011 TABLE 10 Example formulations (amounts in parts by
weight) Component EX-31 EX-32 EX-33 EX-34 EX-35 EX-36 PE-5 40 40 40
40 PE-7 40 40 PE-9 10 PE-10 10 PE-11 10 PE-12 10 PE-15 10 PE-16 10
IBOMA 50 50 50 50 50 50 TPO 2 2 2 2 2 2
TABLE-US-00012 TABLE 11 Example formulations (amounts in parts by
weight) Component EX-37 EX-38 EX-39 EX-40 PE-7 40 40 PE-5 45 PE-32
50 C-590 diol 10 MA C-2050 diol 10 MA DDDMA 5 HDDMA 10 IBOMA 50 50
50 40 TPO 2 2 2 2
TABLE-US-00013 TABLE 12 Example formulations (amounts in parts by
weight) Compo- EX- EX- EX- EX- EX- EX- EX- EX- EX- nents 41 42 43
44 45 46 47 48 49 PE-19 50 PE-5 40 60 PE-32 50 50 50 50 PE-14 45
PE-33 5 PE-7 50 IBOMA 60 40 50 DiCPMA 50 50 AdMA 50 tBuCHMA 50 CHMA
50 TMCHMA 50 TPO 2 2 2 2 2 2 2 2 2
TABLE-US-00014 TABLE 13 Example formulations (amounts in parts by
weight) Components EX-50 EX-51 EX-52 EX-53 EX-54 EX-55 PE-19 50
PE-22 50 PE-27 50 PE-34 50 PE-35 50 PE-36 50 IBOMA 50 50 50 50 IBOA
50 50 TPO 2 2 2 2 2 2
TABLE-US-00015 TABLE 14 Example formulations (amounts in parts by
weight) EX- EX- EX- EX- EX- EX- EX- Components 79 80 81 82 83 84 85
PE-13 45 PE-32 50 PE-45 50 PE-46 50 PE-47 50 PE-48 5 PE-49 50 PE-50
50 tBuCHMA 50 IBOMA 50 50 50 50 50 50 TPO 2 2 2 2 2 2 2
TABLE-US-00016 TABLE 15 Example formulations (amounts in parts by
weight) Components EX-87 EX-88 EX-89 Exothane 10 10 PE-44 50 50 40
IBOMA 40 30 50 HEMA 10 20 TPO 2 2 2
TABLE-US-00017 TABLE 16 Comparative example formulations (amounts
in parts by weight) Components CE-1 CE-2 CE-3 CE-4 CE-5 CE-6 PE-32
50 50 50 50 Exothane 10 30 50 CEA 50 NVP 20 IBOMA 50 EHMA 50 PEMA
50 PEG600DMA 50 THFMA 50 TPO 2 2 2 2 2 2
TABLE-US-00018 TABLE 17 Comparative example formulations (amounts
in parts by weight) Components CE-7 CE-8 CE-9 CE-10 CE-11 CE-12
Exothane 108 50 PE-18 50 PE-17 50 PE-5 30 70 PE-4 50 IBOMA 50 50 50
70 30 50 TPO 2 2 2 2 2 2 BHT 0.025 0.025 0.025
Polymer/Oligomer Molecular Weight Characterization Method:
[0379] The molecular weights of the oligomers and the polymers were
characterized using gel permeation chromatography (GPC). The GPC
equipment consisted of an e2695 Separation Module and a 2414 dRI
detector, both from Waters Corporation (Milford, Mass.). It was
operated at a flow rate of 0.6 mL/min using tetrahydrofuran as the
eluent. The GPC column was a HSPgel HR MB-M column also from Waters
Corporation. The column compartment and differential refractive
index detector were set to 35.degree. C. The molecular weight
standards were EasiVial PMMA from Agilent Technologies (The M.sub.p
values of the PMMA molecular weight standards used in the
calibration curve ranged from 550 D to 1,568,000 g/mol.) The
relative number average molecular weight (Mn) and weight average
molecular weight (Mn) of selected oligomers/polymers are tabulated
below in Table 18, in kiloDaltons (kD):
TABLE-US-00019 TABLE 18 Sample Mn (kD) Mw (kD) Polydispersity PE-6
4.3 18.1 4.2 PE-7 3.5 12.1 3.4 PE-8 3.5 12.4 3.5 PE-9 3.0 7.5 2.5
PE-10 3.1 7.4 2.4 PE-11 3.1 8.1 2.6 PE-12 3.3 8.7 2.6 PE-13 4.3
17.9 4.1 PE-14 4.5 11.5 2.6 PE-17 1.6 6.3 4.1 PE-18 3.8 12.9 3.4
PE-19 2.1 8.9 4.3 PE-20 5.0 16.4 3.3 PE-21 3.7 14.3 3.9 PE-22 3.1
11.6 3.7 PE-23 3.9 17.0 4.4 PE-24 3.4 14.0 4.1 PE-25 2.0 5.6 2.8
PE-26 2.9 12.8 4.3 PE-27 3.3 14.0 4.3 PE-28 2.8 12.3 4.4 PE-29 3.6
11.5 3.2 PE-30 2.9 12.9 4.4 PE-31 2.0 9.8 4.9 PE-32 3.9 12.1 3.1
PE-33 4.1 14.4 3.5 PE-35 3.5 12.9 3.7 PE-36 3.6 12.0 3.4 PE-39 7.4
21.8 3.0 PE-40 11.3 30.5 2.7 PE-41 2.8 6.3 2.2 PE-42 3.9 9.1 2.3
PE-43 6.3 15.8 2.5 PE-44 4.6 12.8 2.8 PE-45 14.3 24.6 1.7 PE-46
15.6 25.8 1.8 PE-47 18.3 32.1 1.8
General Procedure of Formulation Casting and Curing
[0380] Each formulation indicated in Tables 5-17 was poured into a
silicone dogbone mold (Type V mold of 1 mm thickness, ASTM D638-14)
for preparing tensile specimens, and a rectangular mold of
dimensions (9.4 mm.times.25.4 mm.times.1 mm) for DMA 3-point bend
test specimens. A 2 mil (0.05 mm) polyethylene terephthalate (PET)
release liner (obtained under the trade designation "SCOTCHPAK"
from 3M Company (St. Paul, Minn.)) was rolled on the filled mold,
and the filled mold along with the liner was placed between two
glass plates held by binder clips. The formulation was cured under
a Asiga Pico Flash post-curing chamber (obtained from Asiga USA,
Anaheim Hills, Calif.) for 30 minutes. The specimens were removed
from the mold followed by additional light exposure for 30 minutes
using the Asiga Pico Flash post-curing chamber. Specimens were then
kept in an oven set at 100.degree. C. for 30 minutes. The dogbone
specimens were conditioned in Phosphate-buffered saline (PBS,
1.times., pH=7.4) for 24 hours at 37.degree. C. The DMA 3-point
bend test specimens were conditioned in de-ionized (DI) water for
48 hours at room temperature.
General Procedure for Determination of Loss Modulus and Tan Delta
Using Dynamic Mechanical Analysis
[0381] Dynamic mechanical analysis (DMA) was performed on
rectangular cured samples (approximately 25.4 mm.times.9.4
mm.times.1 mm) using a TA Instruments model Q800 dynamic mechanical
analyzer (TA Instruments (Newcastle, Del.)) using a tension clamp
in controlled strain mode, 0.2% strain, 0.02 N preload force, 125%
force track, 1 Hz. Temperature was swept at a rate of 2.degree.
C./min from -40.degree. C. to 200.degree. C. Samples were immersed
in deionized water at 37.degree. C. for least 24 hours, at which
time the samples were fully saturated with water prior to testing
and tested immediately after removal from water.
TABLE-US-00020 TABLE 19 Measured physical properties of samples.
Peak loss Peak Tan delta Sample Resin 1 Resin 2 modulus (.degree.
C.) (.degree. C.) EX-8 PE-7 IBOMA 2 121 EX-47 PE-32 CHMA 0 73 CE-12
PE-4 IBOMA 44 129 EX-44 PE-32 AdMA 5 117 CE-1 PE-32 PEMA -7 31 CE-4
PE-32 EHMA -21 26 EX-51 PE-22 IBOA -14 67 CE-6 Exothane 10 IBOMA 31
124
Additive Manufacturing of Formulated Resins
[0382] Unless otherwise noted, all 3D-printed examples were
manufactured either on an Asiga Pico 2 HD or Asiga Max, a vat
polymerization 3D printer available from Asiga USA, Anaheim Hills,
Calif. Each formulation listed in Tables 20-23 was photopolymerized
on an Asiga 3D printer with a LED light source of 385 nm. Tensile
test bars of Type V according to ASTM D638-14 (2014) and DMA
3-point bend test specimens were manufactured. The resin bath of
the printer was heated to 35-50.degree. C. before
photopolymerization to reduce the viscosity to be able to
manufacture the tensile test bars. The following settings were used
for the printing: slice thickness=50 .mu.m; burn in layers=1;
separation velocity=1.5 mm/s, separation distance=10 mm, approach
velocity=1.5 mm/s. On the Asiga Pico 2 HD, 1 slide per layer was
used at a speed of 7 mm/min. In addition, Table 24 describes the
printer type, and the exposure time, burn-in time, and temperature
used for printing the formulations indicated in Tables 20-23. The
printed parts were washed using propylene carbonate followed by
isopropanol to remove unreacted resin. The printed part was then
post-cured using Asiga Pico Flash post-curing chamber for 90
minutes on each side followed by heating in an oven at 100.degree.
C. for 30 minutes. The dogbone specimens were conditioned in
phosphate-buffered saline (PBS, 1.times., pH=7.4) for 24 hours at
37.degree. C. The DMA 3-point bend test specimens were conditioned
in DI water for 48 hours at room temperature.
TABLE-US-00021 TABLE 20 Example formulations for additive
manufacturing (amounts in parts by weight) Components EX-56 EX-57
EX-58 EX-59 EX-60 PE-43 50 PE-44 50 50 50 PE-32 50 IBOMA 50 50 50
50 50 TPO 2 2 0.5 0.5 BHT 0.025 0.025 0.025 0.025 0.025 Omnirad 379
0.75 NapA 0.025 0.025 0.1 0.0175 Tinuvin 326 0.025
TABLE-US-00022 TABLE 21 Example formulations for additive
manufacturing (amounts in parts by weight) Compo- EX- EX- EX- EX-
EX- EX- EX- nents 61 62 63 64 65 66 67 PE-7 47 PE-5 44 PE-6 50
PE-37 50 PE-25 25 PE-13 25 25 20 PE-19 25 30 IBOMA 53 56 50 50 50
50 50 TPO 2 2 2 2 2 2 2 BHT 0.025 0.025 0.025 0.025 0.025 0.025
0.025 NapA 0.025 0.025 0.025 0.025 0.025 0.025 0.025
TABLE-US-00023 TABLE 22 Example formulations for additive
manufacturing (amounts in parts by weight) Compo- EX- EX- EX- EX-
EX- EX- EX- nents 68 69 70 71 72 73 74 PE-5 PE-19 50 PE-44 49.42
45.22 44.69 44.16 39.96 PE-33 5.58 9.78 7.81 5.84 10.04 5 PE-13 45
IBOMA 40 45 45 47.5 50 50 50 HDD- 10 MA TPO 0.5 2 2 2 2 2 2 BHT
0.025 0.025 0.025 0.025 0.025 0.025 0.025 NapA 0.1 0.025 0.025
0.025 0.025 0.025 0.025
TABLE-US-00024 TABLE 23 Example formulations for additive
manufacturing (amounts in parts by weight) Components EX-75 EX-76
EX-77 EX-78 EX-86 PE-19 50 PE-32 50 PE-13 50 PE-30 40 PE-14 10
PE-47 50 DiCPMA 50 AdMA 50 50 50 IBOMA 50 TPO 2 2 2 2 2 BHT 0.025
0.025 0.025 0.025 0.025 NapA 0.025 0.025 0.025 0.025 Tinuvin 326
0.025
TABLE-US-00025 TABLE 24 Additive manufacturing conditions. Exposure
Burn-in Temperature Example Printer Time (sec) Time (sec) (.degree.
C.) EX-56 Asiga Pico 2 HD 2.25 15 50 EX-57 Asiga Max 3 10 40 EX-58
Asiga Max 5 10 40 EX-59 Asiga Pico 2 HD 3.75 20 50 EX-60 Asiga Max
4.5 10 40 EX-61 Asiga Pico 2 HD 2 8 50 EX-62 Asiga Pico 2 HD 2.5 8
50 EX-63 Asiga Max 2.5 10 40 EX-64 Asiga Pico 2 HD 2 8 50 EX-65
Asiga Pico 2 HD 2 8 50 EX-66 Asiga Max 3 10 40 EX-67 Asiga Pico 2
HD 2 8 50 EX-68 Asiga Pico 2 HD 2 8 50 EX-69 Asiga Max 3 10 40
EX-70 Asiga Max 3 10 40 EX-71 Asiga Max 3 10 40 EX-72 Asiga Max 3
10 40 EX-73 Asiga Max 3 10 40 EX-74 Asiga Pico 2 HD 2 8 50 EX-75
Asiga Pico 2 HD 2 8 50 EX-76 Asiga Pico 2 HD 2 8 50 EX-77 Asiga
Pico 2 HD 2 8 50 EX-78 Asiga Pico 2 HD 2 8 50 EX-86 Asiga Max 5 10
40
General Procedure for Tensile Testing
[0383] PBS conditioned dogbones were tested on an Instron 5944
(Instron, Norwood, Mass.) with a 500 N load cell. The test speed
was 5 mm/minute and the initial grip separation was 1 inch (2.5
cm). The gauge length was set to 1 inch (2.5 cm). Five replicate
samples for each formulation were tested, and the average value are
reported. The tensile strength at yield was determined according to
ASTM D638-14 (2014) and shown in Table 25 and Table 26 below. For
specimens that did not yield, maximum tensile strength was
determined. Elongation at break was determined from the crosshead
movement of the grips.
General Procedure for the Determination of Relaxation Modulus Using
Dynamic Mechanical Analysis
[0384] Rectangular specimens were water conditioned by soaking in
deionized water for 48 hours at room temperature at 22 to
25.degree. C. and were tested in a TA Q800 DMA equipped with a
submersion 3-point bending clamp. The water conditioned rectangular
specimens were placed in water filled submersion fixture. The
specimens were equilibrated for 10 minutes at 37.degree. C.,
followed by applying a 2% strain. Relaxation modulus was measured
for 30 minutes using TA Advantage software, and is reported in
Tables 25 and 26.
TABLE-US-00026 TABLE 25 Yield strength, elongation and relaxation
modulus of cast formulations. Percent Loss of Initial Relaxation
Relaxation Strength at Elongation Relaxation Modulus at Modulus
Yield at Break Modulus 30 Minutes After Sample (MPa) (%) (MPa)
(MPa) 30 Minutes CE-1 9.3* 167.5 N.M1 N.M1 N.M1 CE-2 8.6* 181.1
N.M1 N.M1 N.M1 CE-3 1.3* 5.8 N.M1 N.M1 N.M1 CE-4 2.9* 87.7 N.M1
N.M1 N.M1 CE-5 1.2* 32.0 N.M2 N.M2 N.M2 CE-6 46.9 2.9 1662.0 712.5
57.1 CE-7 26.1 9.3 1027.0 265.8 74.1 CE-8 15.2 122.7 401.5 51.2
87.2 CE-9 15.7* 1.0 N.M2 N.M2 N.M2 CE-10 29.3* 1.7 N.M2 N.M2 N.M2
CE-11 25.2* 130.9 106.2 17.2 83.8 CE-12 64.8* 2.8 2829.0 1859.0
34.3 EX-1 56.2 7.6 1442.0 720.9 50.0 EX-2 42.0 12.9 798.4 313.4
60.7 EX-3 28.7 84.2 594.3 212.9 64.2 EX-4 30.7 38.9 794.8 312.4
60.7 EX-5 22.1 80.8 540.8 214.2 60.4 EX-6 17.6 113.9 498.5 198.8
60.1 EX-7 39.1 17.1 1213.0 545.1 55.1 EX-42 39.7 16.5 1096.0 557.9
49.1 EX-43 17.4 92.7 438.1 84.1 80.8 EX-9 22.2 36.4 632.3 174.3
72.4 EX-10 20.2 90.3 565.6 182.2 67.8 EX-11 22.5 70.0 740.8 219.8
70.3 EX-12 14.7 75.8 500.1 143.2 71.4 EX-13 27.7 46.3 922.2 365.7
60.3 EX-14 28.5 46.7 867.1 380.8 56.1 EX-15 23.1 90.7 655.8 258.5
60.6 EX-16 38.3 12.2 949.6 458.8 51.7 EX-50 17.2 64.1 263.4 17.6
93.3 EX-17 26.8 44.7 763.1 219.6 71.2 EX-18 21.1 65.5 498.0 147.6
70.4 EX-19 23.5 15.5 772.8 295.0 61.8 EX-20 35.5 25.1 1020.0 434.7
57.4 EX-21 33.2 30.9 977.7 391.6 59.9 EX-24 27.3 66.6 780.3 287.9
63.1 EX-23 32.9 54.9 1173.0 397.1 66.1 EX-22 30.4 48.0 859.1 368.4
57.1 EX-44 33.3 27.5 837.5 325.0 61.2 EX-45 21.5 67.9 369.7 71.9
80.6 EX-41 32.8 35.2 808.1 229.3 71.6 EX-46 16.6 66.6 345.8 73.6
78.7 EX-47 14.0 125.6 169.0 13.9 91.8 EX-29 28.4 37.8 746.3 267.7
64.1 EX-28 29.0 34.7 879.7 362.3 58.8 EX-26 30.8 47.5 824.4 366.9
55.4 EX-27 37.8 12.5 985.1 476.6 51.6 EX-31 24.1 63.7 612.6 201.5
67.1 EX-32 24.7 58.1 602.8 197.0 67.3 EX-33 26.8 53.9 691.4 246.8
64.3 EX-34 26.3 57.1 577.6 172.8 70.1 EX-35 27.8 53.0 698.4 220.0
68.5 EX-36 34.4 28.4 882.6 327.2 62.9 EX-25 28.7 56.3 738.1 285.1
61.4 EX-30 23.3 51.0 458.0 109.0 76.2 EX-48 24.1 28.2 591.9 177.3
70.0 EX-37 30.0 29.2 691.0 251.7 63.6 EX-38 24.6 66.0 640.6 196.0
69.4 EX-39 32.8 30.5 916.3 410.2 55.2 EX-40 21.3 66.2 570.5 156.7
72.5 EX-8 26.9 54.4 765.0 264.7 65.4 EX-49 22.2* 75.5 261.1 56.1
78.5 EX-52 27.8 63.4 749.0 282.4 62.3 EX-53 25.1 53.0 636.2 236.1
62.9 EX-54 27.9 53.5 761.9 264.1 65.3 EX-55 26.1 49.9 746.3 258.6
65.3 EX-51 18.8* 101.0 121.1 20.5 83.1 EX-79 35.0 14.9 1051.0 457.8
56.4 EX-80 19.6* 28.5 486.0 190.0 60.9 EX-81 30.1 33.3 891.0 369.7
58.5 EX-82 32.7 24.2 924.5 441.3 52.3 EX-83 26.3 50.2 741.5 335.4
54.8 EX-84 29.7 30.4 649.4 311.8 52.0 EX-85 16.6 66.6 345.8 73.6
78.7 EX-87 26.6 66.6 486.2 74.5 84.7 EX-88 16.6 91.9 316.7 21.7
93.14 EX-89 36 23.3 926.9 346.3 62.64 N.M1. Not measured since
these samples were very flexible and soft, and couldn't be
successfully clamped for DMA testing. N.M2. Not measured since
these specimens were very brittle. *maximum tensile strength is
reported for specimens that did not yield.
TABLE-US-00027 TABLE 26 Yield strength, elongation and relaxation
modulus of printed formulations. Percent Loss of Initial Relaxation
Relaxation Strength Elongation Relaxation Modulus at Modulus at
Yield at Break Modulus 30 Minutes After Sample (MPa) (%) (MPa)
(MPa) 30 Minutes EX-56 24.1 91.2 536.0 187.6 65.0 EX-57 25.0 103.0
722.5 252.7 65.0 EX-58 21.6 83.8 666.1 227.7 65.8 EX-59 21.9 126.4
612.7 194.4 68.3 EX-60 23.8 93.2 675.7 226.5 66.5 EX-61 28.3 96.7
857.5 325.0 62.1 EX-62 36.5 24.7 1175.0 460.1 60.8 EX-63 29.0 76.4
710.8 277.7 60.9 EX-64 27.1 126.0 805.2 303.4 62.3 EX-65 31.3 70.4
978.2 383.7 60.8 EX-66 25.0 111.1 406.3 157.2 61.3 EX-67 29.4 75.0
879.5 368.8 58.1 EX-68 24.2 32.8 620.9 211.2 66.0 EX-69 26.7 65.5
696.4 249.4 64.2 EX-70 35.6 41.2 1007.0 436.1 56.7 EX-71 35.7 43.5
983.0 441.2 55.1 EX-72 36.6 42.9 925.3 413.6 55.3 EX-73 43.7 20.6
1199.0 564.8 52.9 EX-74 23.8 98.7 649.0 261.8 59.7 EX-75 28.9 74.7
800.3 249.1 68.9 EX-76 30.3 88.7 789.4 288.3 63.5 EX-77 22.7 144.9
738.1 285.1 61.4 EX-78 27.6 95.9 707.1 265.0 62.5 EX-86 28.9 28.3
715.4 322.7 54.9
Additive Manufacturing of Aligner Articles from the Formulated
Resin
[0385] The formulation of EX-57 was photopolymerized on the Asiga
Max printer with a LED light source of 385 nm. A stereolithography
file format (STL file) of the aligner was loaded into the Asiga
Composer software, and support structures were generated. The resin
bath of the printer was heated to 40.degree. C. before
photopolymerization to reduce the viscosity to be able to
manufacture the article. The following settings were used for the
printing: slice thickness=50 .mu.m; burn in layers=1; separation
velocity=1.5 mm/min, burn-in exposure time=10 sec; exposure time=3
sec. The printed part was washed using propylene carbonate followed
by isopropanol to remove unreacted resin. The printed specimen was
then post-cured using an Asiga Pico Flash post-curing chamber for
90 minutes on each side. The photopolymerized aligners fit the
models, showing precision of the additive manufacture part. The
aligner had acceptable strength and flexibility.
Test Procedure for Gravimetric Analysis of Extractable from Printed
Articles
[0386] Articles shaped as a continuous 5-tooth row (30.4
mm.times.9.24 mm.times.8.17 mm) using formulations of EX-57 and
EX-58 were printed and post processed according to the procedure
described above. The thickness of the article was 0.49 mm.
3.times.5-tooth articles (total surface area of 45 cm.sup.2) were
placed in a 40 mL glass vial and weighed. 15 mL of solvent (either
heptane or 5% ethanol/Milli-Q water) was added to the vial, with
one 15 mL blank (vial without articles) for each solvent. The vials
were covered with TEFLON caps, and the samples were kept at
37.degree. C. for 24 hours while shaking at 80 RPM in a LabLine
Bench top incubated shaker Model 4628. The samples were allowed to
cool before transferring the extraction solution to a new 20 mL
glass vial. A 5 mL aliquot was transferred to a preweighed 8 mL
glass vial and set to evaporate under a nitrogen purge. The vials
were weighed once the solvent dried off, until a constant weight
was reached. % Residue was calculated using the following formula
shown below. The test was completed in triplicates, all run at the
same time, and result shown is the average of the three
replicates.
% .times. .times. Residue = [ ( Vial .times. .times. after .times.
.times. evaporation .function. ( g ) - Vial .times. .times. tare
.function. ( g ) ) * 15 .times. .times. mL .times. .times. solvent
Mass .times. .times. of .times. .times. article .times. .times. ( g
) * 5 .times. .times. mL .times. .times. solvent .times. .times.
analyzed ] * 100 ##EQU00001##
TABLE-US-00028 TABLE 27 % Extractable % Extractable in Sample in
Heptane 5% EtOH/H.sub.2O EX-57 0.444 0.129 EX-58 0.280 0.072
[0387] All of the patents and patent applications mentioned above
are hereby expressly incorporated by reference. The embodiments
described above are illustrative of the present invention and other
constructions are also possible. Accordingly, the present invention
should not be deemed limited to the embodiments described in detail
above and shown in the accompanying drawings, but instead only by a
fair scope of the claims that follow along with their
equivalents.
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