U.S. patent application number 14/921901 was filed with the patent office on 2016-02-18 for polycarbonate microfluidic articles.
The applicant listed for this patent is SABIC Global Technologies B.V.. Invention is credited to Bret William Baumgarten, Jon M. Malinoski.
Application Number | 20160045917 14/921901 |
Document ID | / |
Family ID | 50156892 |
Filed Date | 2016-02-18 |
United States Patent
Application |
20160045917 |
Kind Code |
A1 |
Malinoski; Jon M. ; et
al. |
February 18, 2016 |
POLYCARBONATE MICROFLUIDIC ARTICLES
Abstract
Microfluidic devices, and methods for their use are described.
The microfluidic devices include articles formed from a
thermoplastic composition comprising a poly(aliphatic
ester)-polycarbonate comprising soft block ester units, derived
from monomers comprising an alpha, omega C.sub.6-20 aliphatic
dicarboxylic acid or derivative thereof, a dihydroxyaromatic
compound, and a carbonate source.
Inventors: |
Malinoski; Jon M.;
(Zionsville, IN) ; Baumgarten; Bret William; (San
Rafael, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SABIC Global Technologies B.V. |
Bergen op Zoom |
|
NL |
|
|
Family ID: |
50156892 |
Appl. No.: |
14/921901 |
Filed: |
October 23, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14163675 |
Jan 24, 2014 |
9186674 |
|
|
14921901 |
|
|
|
|
61756378 |
Jan 24, 2013 |
|
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Current U.S.
Class: |
422/503 |
Current CPC
Class: |
C08L 2666/18 20130101;
B01L 3/5085 20130101; B01L 2300/12 20130101; C08G 63/64 20130101;
C12Q 1/686 20130101; B01L 3/50851 20130101; B01L 2300/0829
20130101; C08L 67/02 20130101; B01L 2200/06 20130101; B01L 3/5027
20130101; B01L 2200/12 20130101; B01L 2300/0851 20130101; C08L
69/005 20130101; B01L 3/502707 20130101 |
International
Class: |
B01L 3/00 20060101
B01L003/00 |
Claims
1. A microfluidic device, comprising a fluid sample in a channel or
microwell that includes a wall having a fabricated thickness of
less than or equal to 1 mm formed from a thermoplastic composition
comprising: a poly(aliphatic ester)-polycarbonate comprising soft
block ester units, derived from monomers comprising: an alpha,
omega C.sub.6-20 aliphatic dicarboxylic acid or derivative thereof,
a dihydroxyaromatic compound, and a carbonate source.
2. The microfluidic device of claim 1, wherein the fabricated
dimension is 0.005 to 1 mm.
3. The microfluidic device of claim 1, wherein the fabricated
dimension is 0.01 to 0.5 mm.
4. The microfluidic device of claim 1, wherein the fabricated
dimension is 0.05 to 0.2 mm.
5. The microfluidic device of claim 1, wherein the thermoplastic
composition has a melt flow rate of 66 to 150 g/10 min at
300.degree. C. under a load of 1.2 kilograms according to ASTM
D1238-10.
6. The microfluidic device of claim 1, wherein the thermoplastic
composition has an HDT is 80 to 140.degree. C. at 0.45 mega Pascal
(MPa) with an unannealed 3.2 mm plaque according to ASTM
D648-07.
7. The microfluidic device of claim 6, wherein the thermoplastic
composition has a Notched Izod Impact (NII) ductility of 30 to
100%, with a 1/8-inch thick bar (3.18 mm) at 23.degree. C.
according to ASTM D256-10.
8. The microfluidic device of claim 1, wherein the thermoplastic
composition has an HDT is 80 to 140.degree. C. at 1.82 mega Pascal
(MPa) with an unannealed 3.2 mm plaque according to ASTM
D648-07.
9. The microfluidic device of claim 8, wherein the thermoplastic
composition has a Notched Izod Impact (NII) ductility of 30 to
100%, with a 1/8-inch thick bar (3.18 mm) at 23.degree. C.
according to ASTM D256-10.
10. The microfluidic device method of claim 1, wherein the
thermoplastic composition has a Notched Izod Impact (NII) ductility
of 30 to 100%, with 1/8-inch thick bars (3.18 mm) at 23.degree. C.
according to ASTM D256-10.
11. The microfluidic device of claim 1, wherein the article has a
Notched Izod Impact (NII) of 400 to 700 Joules per meter (J/m) with
1/8-inch thick bars (3.18 mm) at 23.degree. C. according to ASTM
D256-10.
12. The microfluidic device of claim 1, wherein the fluid is at a
process temperature of at least 90.degree. C.
13. The microfluidic device of claim 12, wherein the process
temperature is less than or equal to 120.degree. C.
14. The microfluidic device of claim 12, wherein the process
temperature is less than or equal to 110.degree. C.
15. The microfluidic device of claim 12, wherein the process
temperature is at least 95.degree. C.
16. The microfluidic device of claim 12, wherein the process
temperature is from 95.degree. C. to 105.degree. C.
17. The microfluidic device of claim 1, wherein the wall having a
fabricated thickness of less than or equal to 1 mm is a wall having
a molded thickness of less than or equal to 1 mm.
18. The microfluidic device of claim 17, wherein the molded
thickness is 0.005 to 1 mm.
19. The microfluidic device of claim 17, wherein the molded
thickness is 0.01 to 0.5 mm.
20. The microfluidic device of claim 17, wherein the molded
thickness is 0.05 to 0.2 mm.
Description
[0001] This application claims priority to U.S. nonprovisional
application Ser. No. 14/163,675, filed Jan. 24, 2014, which claims
priority to U.S. provisional application 61/756,378 filed Jan. 24,
2013, the disclosures of which are incorporated herein by reference
in their entirety.
TECHNICAL FIELD
[0002] The disclosure generally relates to a thermoplastic
composition with flowability for use in thin walled articles.
BACKGROUND
[0003] Thin walled articles are commonly used in the medical field,
for example in microfluidic and/or polymerase chain reaction (PCR)
applications. Microfluidic applications deal with the precise
control of fluids that are geometrically constrained in
microfluidic devices that can be characterized in general by the
presence of one or more channels with at least one dimension of
less than or equal to 1 millimeter (mm). Obtaining microfluidic
devices that can achieve accurate fine mold detail replication and
that can allow for the production of channels with such small
dimensions is a constant challenge.
[0004] Considering PCR applications, PCR is a process used to
amplify and copy a piece of DNA sequence across multiple orders of
magnitude and is a vital technique in the field of molecular
biology. In the PCR process, the DNA fragment is mixed in aqueous
solution with complementary DNA primers and DNA polymerase enzyme
and the mixture is taken through several thermal cycling steps.
This thermal cycling process separates the double-helix of the
target DNA sequence and initiates new DNA synthesis through the DNA
polymerase catalyst. A typical thermal profile for the PCR reaction
is shown below in Table 1, where .degree. C. is degrees
Celsius.
TABLE-US-00001 TABLE 1 Step Time Duration Temperature (.degree. C.)
Initial Denaturation 2 minutes 94-95 Denaturation 20-30 seconds
94-95 Primer Extension 1 minute 72 Final Extension 5-15 minutes
72
[0005] The PCR reactions are typically carried out in microwells in
arrays from 8 to 96 wells and volumes of 0.2-0.5 milliliters (mL).
Due to the high number of samples in each microwell plate, the
Society of Biomolecular Screening and the American National
Standards Institute (ANSI) have published standards ANSI/SBS 1-2004
through 4-2004 for microwell plates concerning the particular
dimensions and positions of the microwells for microwell plates
having 96, 984, and 1536 wells.
[0006] Efficient heat transfer through the walls of the microwell
to the reaction solution is required for strict temperature control
during the PCR reaction process. In order to achieve efficient heat
transfer, the PCR trays are designed with very thin microwell wall
thicknesses, such as around 0.2 mm. Injection molding of these
thin-wall trays becomes a significant challenge since an extremely
high flow material is required to fill the thin microwell walls. In
addition, the material needs to have sufficient heat resistance to
avoid deformation during the PCR thermal cycling step, and optical
clarity is desired so the liquid volume level can be observed.
Typically, a polypropylene such as PD702 from LYONDELL BASELL is
used for injection molding of the PCR trays. However, polypropylene
is subject to softening at elevated temperatures such as those used
in PCR denaturation cycles, which can cause PCR or other
microfluidic components to become excessively flexible during
processing, and/or be subject to warping or other physical
deformation, and/or leaking.
[0007] Polycarbonate materials have not typically been used for
thin-wall microfluidic applications such as PCR microwells because
while many polycarbonates possess the clarity and high heat
resistance desired for the PCR or other microfluidic applications,
they have generally been thought to lack sufficient flow to fill
the thin tooling required and/or do not have sufficient ductility
at room temperature. Accordingly, polypropylene has generally been
the thermoplastic of choice for PCR and other microfluidic
applications.
[0008] While a number of microfluidic and/or PCR devices fabricated
from polypropylene or other materials that have been used for such
devices have been proposed, there is a continuing need in the art
for materials for use in making thin walled articles that are
compatible with the microfluidic and/or PCR operating
conditions.
SUMMARY
[0009] As further described herein, microfluidic devices can
include articles formed from a thermoplastic composition comprising
a poly(aliphatic ester)-polycarbonate comprising soft block ester
units, derived from monomers comprising an alpha, omega C.sub.6-20
aliphatic dicarboxylic acid or derivative thereof, a
dihydroxyaromatic compound, and a carbonate source.
[0010] In some embodiments, the microfluidic device, comprising a
poly(aliphatic ester)-polycarbonate comprising soft block ester
units, derived from monomers comprising an alpha, omega C.sub.6-20
aliphatic dicarboxylic acid or derivative thereof, a
dihydroxyaromatic compound, and a carbonate source, is a PCR
microwell or a PCR microwell plate.
[0011] Also, as described in further detail below, a method of
using a microfluidic device for processing fluids comprises
[0012] exposing a portion of the device to a processing temperature
at least 90.degree. C.;
[0013] wherein the portion of the device exposed to the processing
temperature includes an article formed from a thermoplastic
composition comprising:
[0014] a poly(aliphatic ester)-polycarbonate comprising soft block
ester units, derived from monomers comprising an alpha, omega
C.sub.6-20 aliphatic dicarboxylic acid or derivative thereof, a
dihydroxyaromatic compound, and a carbonate source.
[0015] Also provided is a microfluidic device for processing fluids
at a process temperature of at least 90.degree. C., the device
comprising an article exposed to the process temperature formed
from a thermoplastic composition comprising a thermoplastic
composition comprising
[0016] a poly(aliphatic ester)-polycarbonate comprising soft block
ester units, derived from monomers comprising an alpha, omega
C.sub.6-20 aliphatic dicarboxylic acid or derivative thereof, a
dihydroxyaromatic compound, and a carbonate source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a more complete understanding of the present
application, reference is now made to the following descriptions
taken in conjunction with the accompanying figures in which:
[0018] FIG. 1 is an illustration of a typical microfluidic plate;
and
[0019] FIG. 2 is an illustration of a typical microwell plate.
DETAILED DESCRIPTION
[0020] The thermoplastic composition used to make the microfluidic
devices described herein is also referred to as the high flow
thermoplastic composition that comprises polycarbonate,
specifically a polyester-polycarbonate copolymer, more specifically
a poly(aliphatic ester)-polycarbonate copolymer. Generally, as used
herein, the term "polycarbonate" refers to the repeating structural
carbonate units of the formula (1)
##STR00001##
in which at least 60 percent of the total number of R.sup.1 groups
contain aromatic moieties and the balance thereof are aliphatic,
alicyclic, or aromatic. Each R.sup.1 can be an aromatic radical of
the formula -A.sup.1-Y.sup.1-A.sup.2-. Each R.sup.1 can comprise a
C.sub.6-30 aromatic group, that is, contains at least one aromatic
moiety. R.sup.1 can be derived from a dihydroxy compound of the
formula HO--R.sup.1--OH, in particular of formula (2)
HO-A.sup.1-Y.sup.1-A.sup.2-OH (2)
wherein each of A.sup.1 and A.sup.2 is a monocyclic divalent
aromatic group and Y.sup.1 is a single bond or a bridging group
having one or more atoms that separate A.sup.1 from A.sup.2. In an
embodiment, one atom separates A.sup.1 from A.sup.2. Illustrative
non-limiting examples of radicals of this type are --O--, --S--,
--S(O)--, S(O).sub.2--, --C(O)--, methylene, cyclohexylmethylene,
2-[2.2.1]-bicycloheptylidene, ethylidene, isopropylidene,
neopentylidene, cyclohexylidene, cyclopentadecylidene,
cyclododecylidene, and adamantylidene. The bridging radical Y.sup.1
can be a hydrocarbon group or a saturated hydrocarbon group such as
methylene, cyclohexylidene, or isopropylidene. Specifically, the
R.sup.1 groups can be derived from a dihydroxy aromatic compound of
formula (3)
##STR00002##
wherein R.sup.a and R.sup.b are each independently a halogen,
C.sub.1-12 alkoxy, or C.sub.1-12 alkyl; and p and q are each
independently integers of 0 to 4. It will be understood that
R.sup.a is hydrogen when p is 0, and likewise R.sup.b is hydrogen
when q is 0. Also in formula (3), X.sup.a is a bridging group
connecting the two hydroxy-substituted aromatic groups, where the
bridging group and the hydroxy substituent of each C.sub.6 arylene
group are disposed ortho, meta, or para (specifically para) to each
other on the C.sub.6 arylene group. Examples of the bridging group
X.sup.a include a single bond, --O--, --S--, --S(O)--,
S(O).sub.2--, --C(O)--, or a C.sub.1-18 organic group. The
C.sub.1-18 organic bridging group can be cyclic or acyclic,
aromatic or non-aromatic, and can further comprise heteroatoms such
as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. The
C.sub.1-18 organic group can be disposed such that the C.sub.6
arylene groups connected thereto are each connected to a common
alkylidene carbon or to different carbons of the C.sub.1-18 organic
bridging group. In an embodiment, p and q are each 1, and R.sup.a
and R.sup.b are each a C.sub.1-3 alkyl group, specifically methyl,
disposed meta to the hydroxy group on each arylene group. X.sup.a
can be a substituted or unsubstituted C.sub.3-18 cycloalkylidene, a
C.sub.1-25 alkylidene of formula --C(R.sup.c)(R.sup.d)-- wherein
R.sup.c and R.sup.d are each independently hydrogen, C.sub.1-12
alkyl, C.sub.1-12 cycloalkyl, C.sub.7-12 arylalkyl, C.sub.1-12
heteroalkyl, or cyclic C.sub.7-12 heteroarylalkyl, or a group of
the formula --C(.dbd.R.sup.e)-- wherein R.sup.e is a divalent
C.sub.1-12 hydrocarbon group such as methylene,
cyclohexylmethylene, ethylidene, neopentylidene, and
isopropylidene, as well as 2-[2.2.1]-bicycloheptylidene,
cyclohexylidene, cyclopentylidene, cyclododecylidene, or
adamantylidene.
[0021] Bisphenols containing substituted or unsubstituted
cyclohexane units can also be used as a dihydroxy compound, for
example bisphenols of the formula (4)
##STR00003##
wherein each R.sup.f is independently hydrogen, C.sub.1-12 alkyl,
or halogen; and each R.sup.g is independently hydrogen or
C.sub.1-12 alkyl. The substituents can be aliphatic or aromatic,
straight chain, cyclic, bicyclic, branched, saturated, or
unsaturated. Such cyclohexane-containing bisphenols, for example
the reaction product of two moles of a phenol with one mole of a
hydrogenated isophorone, can be used to make polycarbonate polymers
with high glass transition temperatures and high heat distortion
temperatures. Cyclohexyl bisphenol containing polycarbonates, or a
combination comprising at least one of the foregoing with other
bisphenol polycarbonates, are supplied by BAYER CO. under the APEC*
trade name.
[0022] Other aromatic dihydroxy compounds of the formula
HO--R.sup.1--OH include compounds of formula (5)
##STR00004##
wherein each R.sup.h is independently a halogen atom, a C.sub.1-10
hydrocarbyl such as a C.sub.1-10 alkyl group, a halogen-substituted
C.sub.1-10 alkyl group, a C.sub.6-10 aryl group, or a
halogen-substituted C.sub.6-10 aryl group, and n is 0 to 4. The
halogen can be bromine.
[0023] Some illustrative examples of specific aromatic dihydroxy
compounds include the following: 4,4'-dihydroxybiphenyl,
1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene,
bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane,
bis(4-hydroxyphenyl)-1-naphthylmethane,
1,2-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)-1-phenylethane,
2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane,
bis(4-hydroxyphenyl)phenylmethane,
2,2-bis(4-hydroxy-3-bromophenyl)propane,
1,1-bis(hydroxyphenyl)cyclopentane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)isobutene,
1,1-bis(4-hydroxyphenyl)cyclododecane,
trans-2,3-bis(4-hydroxyphenyl)-2-butene,
2,2-bis(4-hydroxyphenyl)adamantane, alpha,
alpha'-bis(4-hydroxyphenyl)toluene,
bis(4-hydroxyphenyl)acetonitrile,
2,2-bis(3-methyl-4-hydroxyphenyl)propane,
2,2-bis(3-ethyl-4-hydroxyphenyl)propane,
2,2-bis(3-n-propyl-4-hydroxyphenyl)propane,
2,2-bis(3-isopropyl-4-hydroxyphenyl)propane,
2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane,
2,2-bis(3-t-butyl-4-hydroxyphenyl)propane,
2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,
2,2-bis(3-allyl-4-hydroxyphenyl)propane,
2,2-bis(3-methoxy-4-hydroxyphenyl)propane,
2,2-bis(4-hydroxyphenyl)hexafluoropropane,
1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene,
1,1-dibromo-2,2-bis(4-hydroxyphenyl)ethylene,
1,1-dichloro-2,2-bis(5-phenoxy-4-hydroxyphenyl)ethylene,
4,4'-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone,
1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, ethylene glycol
bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether,
bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide,
bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorine,
2,7-dihydroxypyrene,
6,6'-dihydroxy-3,3,3',3'-tetramethylspiro(bis)indane
("spirobiindane bisphenol"), 3,3-bis(4-hydroxyphenyl)phthalimide,
2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene,
2,7-dihydroxyphenoxathin, 2,7-dihydroxy-9,10-dimethylphenazine,
3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and
2,7-dihydroxycarbazole, resorcinol, substituted resorcinol
compounds such as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl
resorcinol, 5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl
resorcinol, 5-cumyl resorcinol, 2,4,5,6-tetrafluoro resorcinol,
2,4,5,6-tetrabromo resorcinol, or the like; catechol; hydroquinone;
substituted hydroquinones such as 2-methyl hydroquinone, 2-ethyl
hydroquinone, 2-propyl hydroquinone, 2-butyl hydroquinone,
2-t-butyl hydroquinone, 2-phenyl hydroquinone, 2-cumyl
hydroquinone, 2,3,5,6-tetramethyl hydroquinone,
2,3,5,6-tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluoro
hydroquinone, 2,3,5,6-tetrabromo hydroquinone, or the like, or
combinations comprising at least one of the foregoing dihydroxy
compounds.
[0024] Specific examples of bisphenol compounds of formula (3)
include 1,1-bis(4-hydroxyphenyl) methane, 1,1-bis(4-hydroxyphenyl)
ethane, 2,2-bis(4-hydroxyphenyl) propane (hereinafter "bisphenol A"
or "BPA"), 2,2-bis(4-hydroxyphenyl) butane,
2,2-bis(4-hydroxyphenyl) octane, 1,1-bis(4-hydroxyphenyl) propane,
1,1-bis(4-hydroxyphenyl) n-butane,
2,2-bis(4-hydroxy-2-methylphenyl) propane,
1,1-bis(4-hydroxy-t-butylphenyl) propane, 3,3-bis(4-hydroxyphenyl)
phthalimidine, 2-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine
(PPPBP), and 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (DMBPC).
Combinations comprising at least one of the foregoing dihydroxy
compounds can also be used.
[0025] In some embodiments, the polycarbonate is a linear
homopolymer derived from bisphenol A, in which each of A.sup.1 and
A.sup.2 is p-phenylene and Y.sup.1 is isopropylidene in formula
(3).
[0026] The polycarbonates can have an intrinsic viscosity, as
determined in chloroform at 25.degree. C., of 0.3 to 1.5 deciliters
per gram (dl/g), specifically 0.45 to 1.0 dl/g. The polycarbonates
can have a weight average molecular weight (M.sub.w) of 10,000 to
100,000 grams per mole (g/mol), as measured by gel permeation
chromatography (GPC) using a cross-linked styrene-divinyl benzene
column, at a sample concentration of 1 milligram per milliliter,
and as calibrated with polycarbonate standards. The polycarbonate
can have a melt volume flow rate (often abbreviated MVR) that
measures the rate of extrusion of a thermoplastics through an
orifice at a prescribed temperature and load. Polycarbonates for
the formation of articles can have an MVR, measured at 300.degree.
C. under a load of 1.2 kg according to ASTM D1238-10 or ISO 1133,
of 0.5 to 80 cubic centimeters per 10 minutes (cc/10 min).
[0027] "Polycarbonates" and "polycarbonate resins" as used herein
further include homopolycarbonates, copolymers comprising different
R.sup.1 moieties in the carbonate (referred to herein as
"copolycarbonates"), copolymers comprising carbonate units and
other types of polymer units, such as ester units, polysiloxane
units, and combinations comprising at least one of
homopolycarbonates and copolycarbonates. As used herein,
"combination" is inclusive of blends, mixtures, alloys, reaction
products, and the like. A specific type of copolymer is a polyester
carbonate, also known as a polyester-polycarbonate. Such copolymers
further contain, in addition to recurring carbonate chain units of
the formula (1), units of formula (6)
##STR00005##
wherein R.sup.2 is a divalent group derived from a dihydroxy
compound, and can be, for example, a C.sub.2-10 alkylene group, a
C.sub.6-20 alicyclic group, a C.sub.6-20 aromatic group or a
polyoxyalkylene group in which the alkylene groups contain 2 to 6
carbon atoms, specifically 2, 3, or 4 carbon atoms. R.sup.2 can be
a C.sub.2-30 alkylene group having a straight chain, branched
chain, or cyclic (including polycyclic) structure. Alternatively,
R.sup.2 can be derived from an aromatic dihydroxy compound of
formula (3) above, or from an aromatic dihydroxy compound of
formula (5) above. T is a divalent group derived from a
dicarboxylic acid (aliphatic, aromatic, or alkyl aromatic), and can
be, for example, a C.sub.4-18 aliphatic group, a C.sub.6-20
alkylene group, a C.sub.6-20 alicyclic group, a C.sub.6-20 alkyl
aromatic group, or a C.sub.6-20 aromatic group.
[0028] Examples of aromatic dicarboxylic acids that can be used to
prepare the polyester units include isophthalic or terephthalic
acid, 1,2-di(p-carboxyphenyl)ethane, 4,4'-dicarboxydiphenyl ether,
4,4'-bisbenzoic acid, and combinations comprising at least one of
the foregoing acids. Acids containing fused rings can also be
present, such as in 1,4-, 1,5-, or 2,6-naphthalenedicarboxylic
acids. Specific dicarboxylic acids are terephthalic acid,
isophthalic acid, naphthalene dicarboxylic acid, cyclohexane
dicarboxylic acid, or combinations thereof. A specific dicarboxylic
acid comprises a combination of isophthalic acid and terephthalic
acid wherein the weight ratio of isophthalic acid to terephthalic
acid is 91:9 to 2:98. In another specific embodiment, R.sup.2 is a
C.sub.2-6 alkylene group and T is p-phenylene, mphenylene,
naphthalene, a divalent cycloaliphatic group, or a combination
thereof. This class of polyester includes the poly(alkylene
terephthalates).
[0029] The molar ratio of ester units to carbonate units in the
copolymers can vary broadly, for example 1:99 to 99:1, specifically
10:90 to 90:10, more specifically 25:75 to 75:25, depending on the
desired properties of the final composition.
[0030] The thermoplastic composition can comprise a
polyester-polycarbonate copolymer, specifically a
polyester-polycarbonate copolymer in which the ester units of
formula (6) comprise soft block ester units, also referred to
herein as aliphatic dicarboxylic acid ester units. Such a
polyester-polycarbonate copolymer comprising soft block ester units
is also referred to herein as a poly(aliphatic
ester)-polycarbonate. The soft block ester unit can be a C.sub.6-20
aliphatic dicarboxylic acid ester unit (where C.sub.6-20 includes
the terminal carboxyl groups), and can be straight chain (i.e.,
unbranched) or branched chain dicarboxylic acids, cycloalkyl or
cycloalkylidene-containing dicarboxylic acids units, or
combinations of these structural units. In some embodiments, the
C.sub.6-20 aliphatic dicarboxylic acid ester unit includes a
straight chain alkylene group comprising methylene (--CH.sub.2--)
repeating units. In some embodiments, a soft block ester unit
comprises units of formula (6a)
##STR00006##
wherein m is 4 to 18, more specifically 8 to 10. The poly(aliphatic
ester)-polycarbonate can include less than or equal to 25 weight %
of the soft block unit. The poly(aliphatic ester)-polycarbonate can
comprise units of formula (6a) in an amount of 0.5 to 10 weight %,
specifically 2 to 9 weight %, and more specifically 3 to 8 weight
%, based on the total weight of the poly(aliphatic
ester)-polycarbonate. The poly(aliphatic ester)-polycarbonate can
have a glass transition temperature of 110 to 145.degree. C.,
specifically 115 to 145.degree. C., more specifically 128 to
139.degree. C., even more specifically 130 to 139.degree. C.
[0031] The poly(aliphatic ester)-polycarbonate is a copolymer of
soft block ester units with carbonate units. The poly(aliphatic
ester)-polycarbonate is shown in formula (6b)
##STR00007##
where each R.sup.3 is independently derived from a
dihydroxyaromatic compound of formula (3) or (5), m is 4 to 18, and
x and y each represent average weight percentages of the
poly(aliphatic ester)-polycarbonate where the average weight
percentage ratio x:y is 10:90 to 0.5:99.5, specifically 9:91 to
1:99, and more specifically 8:92 to 3:97, where x+y is 100.
[0032] Soft block ester units, as defined herein, can be derived
from an alpha, omega C.sub.6-20, specifically, C.sub.10-12,
aliphatic dicarboxylic acid or a reactive derivative thereof. The
carboxylate portion of the aliphatic ester unit of formula (6a), in
which the terminal carboxylate groups are connected by a chain of
repeating methylene (--CH.sub.2--) units (where m is as defined for
formula (6a)), can be derived from the corresponding dicarboxylic
acid or reactive derivative thereof, such as the acid halide
(specifically, the acid chloride), an ester, or the like. Exemplary
alpha, omega dicarboxylic acids (from which the corresponding acid
chlorides can be derived) include alpha, omega C.sub.6 dicarboxylic
acids such as hexanedioic acid (also referred to as adipic acid);
alpha, omega C.sub.10 dicarboxylic acids such as decanedioic acid
(also referred to as sebacic acid); and alpha, omega C.sub.12
dicarboxylic acids such as dodecanedioic acid (sometimes
abbreviated as DDDA). It will be appreciated that the aliphatic
dicarboxylic acid is not limited to these exemplary carbon chain
lengths, and that other chain lengths within the C.sub.6-20
limitation can be used. In some embodiments, the poly(aliphatic
ester)-polycarbonate having soft block ester units comprising a
straight chain methylene group and a bisphenol A polycarbonate
group is shown in formula (6c)
##STR00008##
where m is 4 to 18 and x and y are as defined for formula (6b). In
an embodiment, the poly(aliphatic ester)-polycarbonate copolymer
comprises sebacic acid ester units and bisphenol A carbonate units
(formula (6c), where m is 8, and the average weight ratio of x:y is
6:94).
[0033] The poly(aliphatic ester)-polycarbonate copolymer, as
described above, can be a polycarbonate having aliphatic
dicarboxylic acid ester soft block units randomly incorporated
along the copolymer chain. The introduction of the soft block
segment (e.g., a flexible chain of repeating CH.sub.2 units) in the
polymer chain of a polycarbonate reduces the glass transition
temperatures (T.sub.g) of the resulting soft block containing
polycarbonate copolymer. These materials are generally transparent
and have higher melt volume ratios than polycarbonate homopolymers
or copolymers without the soft block.
[0034] The poly(aliphatic ester)-polycarbonate copolymer, i.e., a
polycarbonate having aliphatic dicarboxylic acid ester soft block
units randomly incorporated along the copolymer chain, has soft
block segment (e.g., a flexible chain of repeating --CH.sub.2--
units) in the polymer chain, where inclusion of these soft block
segments in a polycarbonate reduces the glass transition
temperatures (T.sub.g) of the resulting soft block-containing
polycarbonate copolymer. These thermoplastic compositions,
comprising soft block in amounts of 0.5 to 10 wt % of the weight of
the poly(aliphatic ester)-polycarbonate, are transparent and have
higher MVR than polycarbonate homopolymers or copolymers without
the soft block.
[0035] The poly(aliphatic ester)-polycarbonate can have clarity and
light transmission properties, where a sufficient amount of light
with which to make photometric or fluorometric measurement of
specimens contained within the channels and/or wells of an article
made thereof can pass through the thermoplastic composition. The
poly(aliphatic ester)-polycarbonate can have 80 to 100%
transmission, more specifically, 89 to 100% light transmission as
determined by ASTM D1003-11, using 3.2 mm thick plaques. The
poly(aliphatic ester)-polycarbonate can also have low haze,
specifically 0.001 to 5%, more specifically, 0.001 to 1% as
determined by ASTM D1003-11 using 3.2 mm thick plaques.
[0036] While the soft block units of the poly(aliphatic
ester)-polycarbonate copolymers cannot be specifically limited to
the alpha, omega C.sub.6-20 dicarboxylic acids disclosed herein, it
is believed that shorter soft block chain lengths (less than
C.sub.6, including the carboxylic acid groups) cannot provide
sufficient chain flexibility in the poly(aliphatic
ester)polycarbonate to increase the MVR to the desired levels
(i.e., greater than or equal to 13 cc/10 min at 250.degree. C. and
1.2 kg load); likewise, increasing the soft block chain lengths
(greater than C.sub.20, including the carboxylic acid groups) can
result in creation of crystalline domains within the poly(aliphatic
ester)-polycarbonate composition, which in turn can lead to phase
separation of the domains that can manifest as reduced transparency
and increased haze, and can affect the thermal properties such as
T.sub.g (where multiple T.sub.g values can result for different
phase separated domains) and MVR (decreasing MVR to values of less
than 13 cc/10 min at 250.degree. C. and 1.2 kg load).
[0037] Exemplary thermoplastic compositions include poly(sebacic
acid ester)-co-(bisphenol A carbonate). It will be understood that
a wide variety of thermoplastic compositions and articles derived
from them can be obtained by not only changing the thermoplastic
compositions (e.g., by replacing sebacic acid with adipic acid in
the poly(sebacic acid ester)-co-(bisphenol A carbonate) but by
changing the amounts of sebacic or other aliphatic acid content in
the blends while maintaining a constant molecular weight or while
varying the molecular weight. Similarly, new thermoplastic
compositions can be identified by changing the molecular weights of
the components in the exemplary copolymer blends while keeping, for
example, sebacic acid content constant.
[0038] The ductility, transparency and melt flow of the
thermoplastic compositions may be varied by the composition of the
poly(aliphatic ester)-polycarbonate. For example, wt % of aliphatic
dicarboxylic acid ester units (e.g., sebacic acid) may be varied
from 1 to 10 wt % of the total weight of the thermoplastic
composition. The distribution (in the polymer chain) of the sebacic
acid (or other dicarboxylic acid ester) in the copolymers may also
be varied by choice of synthetic method of the poly(aliphatic
ester)-polycarbonate copolymers (e.g., interfacial, melt processed,
or further reactive extrusion of a low MVR poly(aliphatic
ester)-polycarbonate with a redistribution catalyst) to obtain the
desired properties. In this way, thermoplastic compositions having
high flow (e.g. MVR of up to 25 cc/10 min. at 1.2 Kg and
250.degree. C.) may further be achieved where the poly(aliphatic
ester)-polycarbonate is too low in MVR, or is opaque (where the
soft blocks are too great in length, the concentration of the soft
block in the copolymer is too high, or where the overall molecular
weight of the copolymer is too high, or where the copolymer has a
block architecture in which the soft block units in the copolymer
aggregate to form larger blocks), while transparent products with
greater than or equal to 85% transmission, haze of less than 1%
(measured on a 3.2 mm thick molded plaque), and high flow (e.g., up
to an MVR of 25 cc/10 min. at 1.2 Kg and 250.degree. C.), and
ductility may be obtained. Thermoplastic compositions having this
combination of properties is not obtainable from polycarbonate
compositions of, for example, bisphenol A polycarbonate homopolymer
absent a poly(aliphatic ester)-polycarbonate copolymer.
[0039] Polyester-polycarbonate copolymers generally can have a
weight average molecular weight (M.sub.w) of 1,500 to 100,000 grams
per mole (g/mol), specifically 1,700 to 50,000 g/mol. In an
embodiment, poly(aliphatic ester)-polycarbonates have a molecular
weight of 15,000 to 45,000 g/mol, specifically 17,000 to 40,000
g/mol, more specifically 20,000 to 30,000 g/mol, and still more
specifically 20,000 to 25,000 g/mol. Molecular weight
determinations are performed using gel permeation chromatography
(GPC), using a cross-linked styrene-divinylbenzene column and
calibrated to polycarbonate references. Samples are prepared at a
concentration of 1 milligram (mg)/mL, and are eluted at a flow rate
of 1.0 mL/min.
[0040] Polyester-polycarbonates can exhibit melt flow rates as
described by the melt volume ratio (MVR) of 5 to 150 cubic
centimeters (cc)/10 min, specifically 7 to 125 cc/10 min, more
specifically 9 to 110 cc/10 min, and still more specifically 10 to
100 cc/10 min, measured at 300.degree. C. and a load of 1.2 kg
according to ASTM D1238-10. The poly(aliphatic ester)-polycarbonate
can have an MVR of 66 to 150 g/10 min, and more specifically 100 to
150 g/10 min, measured at 300.degree. C. and under a load of 1.2
kilograms according to ASTM D1238-10. Commercial polyester blends
with polycarbonate are marketed under the trade name XYLEX.RTM.,
including for example XYLEX.RTM. X7300, and commercial
polyester-polycarbonates are marketed under the trade name
LEXAN.RTM. SLX polymers, including for example LEXAN.RTM. SLX-9000,
and are available from SABIC Innovative Plastics (formerly GE
Plastics). In an embodiment, poly(aliphatic ester)-polycarbonates
have an MVR of 13 to 25 cc/10 min, and more specifically 15 to 22
cc/10 min, measured at 250.degree. C. and under a load of 1.2
kilograms and a dwell time of 6 minutes, according to ASTM
D1238-10. Also in an embodiment, poly(aliphatic
ester)-polycarbonates have an MVR of 13 to 25 cc/10 min, and more
specifically 15 to 22 cc/10 min, measured at 250.degree. C. and
under a load of 1.2 kilograms and a dwell time of 4 minutes,
according to ISO 1133.
[0041] The thermoplastic composition can further comprise another
thermoplastic polymer such as a polycarbonate polyester copolymer
different from the poly(aliphatic ester)-polycarbonate copolymer, a
polycarbonate, a polyester, a polysiloxane-polycarbonate copolymer,
or combinations comprising one or more of the foregoing.
[0042] The thermoplastic composition can thus comprise
poly(aliphatic ester)-polycarbonate copolymer, and optionally a
polycarbonate polymer not identical to the poly(aliphatic
ester)-polycarbonate. Such added polycarbonate polymer may be
included but is not essential to the thermoplastic composition. In
an embodiment, where desired, the thermoplastic composition may
include the polycarbonate in amounts of less than or equal to 50 wt
%, based on the total weight of poly(aliphatic ester)-polycarbonate
and any added polycarbonate. Specifically useful in the
thermoplastic polymer include homopolycarbonates, copolycarbonates,
polyester-polycarbonates, polysiloxane-polycarbonates, blends
thereof with polyesters, and combinations comprising at least one
of the foregoing polycarbonate-type resins or blends. It should
further be noted that the inclusion of other polymers such as
polycarbonate is permitted provided the desired properties of the
thermoplastic composition are not significantly adversely affected.
In a specific embodiment, a thermoplastic composition consists
essentially of a poly(aliphatic ester)-polycarbonate copolymer. In
another specific embodiment, the thermoplastic composition consists
of poly(aliphatic ester)-polycarbonate copolymer.
[0043] When the poly(aliphatic ester)-polycarbonate is blended with
other polymer, the thermoplastic composition can comprise
polycarbonate, including blends of polycarbonate homo and/or
copolymers, polyesters, polyester-polycarbonates other than the
poly(aliphatic ester)-polycarbonates disclosed above, or
polysiloxane-polycarbonate in an amount of less than or equal to 50
wt %, specifically 1 to 50 wt %, and more specifically 10 to 50 wt
%, based on the total weight of poly(aliphatic ester)-polycarbonate
and any added polycarbonate, provided the addition of the
polycarbonate does not significantly adversely affect the desired
properties of the thermoplastic composition. Where a polycarbonate
is used in addition to the poly(aliphatic ester)-polycarbonate, the
polycarbonate (or a combination of polycarbonates, i.e., a
polycarbonate composition) can have an MVR measured at 300.degree.
C. under a load of 1.2 kg according to ASTM D1238-10 or ISO 1133,
of 45 to 75 cc/10 min, specifically 50 to 70 cc/10 min, and more
specifically 55 to 65 cc/10 min.
[0044] Polyesters can include, for example, polyesters having
repeating units of formula (6), which include poly(alkylene
dicarboxylates), liquid crystalline polyesters, and polyester
copolymers. The polyesters described herein are generally
completely miscible with the polycarbonates when blended.
[0045] Such polyesters generally include aromatic polyesters,
poly(alkylene esters) including poly(alkylene arylates), and
poly(cycloalkylene diesters). Aromatic polyesters can have a
polyester structure according to formula (8), wherein D and T are
each aromatic groups as described hereinabove. In an embodiment,
aromatic polyesters can include, for example,
poly(isophthalate-terephthalate-resorcinol) esters,
poly(isophthalate-terephthalate-bisphenol A) esters,
poly[(isophthalate-terephthalate-resorcinol)
ester-co-(isophthalate-terephthalate-bisphenol A)] ester, or a
combination comprising at least one of these. Also contemplated are
aromatic polyesters with a minor amount, e.g., 0.5 to 10 wt %,
based on the total weight of the polyester, of units derived from
an aliphatic diacid and/or an aliphatic polyol to make
copolyesters. Poly(alkylene arylates) can have a polyester
structure according to formula (8), wherein T comprises groups
derived from aromatic dicarboxylates, cycloaliphatic dicarboxylic
acids, or derivatives thereof. Examples of specific T groups
include 1,2-, 1,3-, and 1,4-phenylene; 1,4- and 1,5-naphthylenes;
cis- or trans-1,4-cyclohexylene; and the like. Specifically, where
T is 1,4-phenylene, the poly(alkylene arylate) is a poly(alkylene
terephthalate). In addition, for poly(alkylene arylate), specific
alkylene groups D include, for example, ethylene, 1,4-butylene, and
bis-(alkylene-disubstituted cyclohexane) including cis- and/or
trans-1,4-(cyclohexylene)dimethylene. Examples of poly(alkylene
terephthalates) include poly(ethylene terephthalate) (PET),
poly(1,4-butylene terephthalate) (PBT), and poly(propylene
terephthalate) (PPT). Poly(alkylene naphthoates), such as
poly(ethylene naphthanoate) (PEN), and poly(butylene naphthanoate)
(PBN), or poly(cycloalkylene diesters) such as
poly(cyclohexanedimethylene terephthalate) (PCT), can also be used.
Combinations comprising at least one of the foregoing polyesters
can also be used.
[0046] Copolymers comprising alkylene terephthalate repeating ester
units with other ester groups can also be used. Ester units can
include different alkylene terephthalate units, which can be
present in the polymer chain as individual units, or as blocks of
poly(alkylene terephthalates). Specific examples of such copolymers
include poly(cyclohexanedimethylene terephthalate)-co-poly(ethylene
terephthalate), abbreviated as PETG where the polymer comprises
greater than or equal to 50 mole % of poly(ethylene terephthalate),
and abbreviated as PCTG where the polymer comprises greater than 50
mole % of poly(1,4-cyclohexanedimethylene terephthalate).
[0047] Poly(cycloalkylene diester)s can also include poly(alkylene
cyclohexanedicarboxylate)s. Of these, a specific example is
poly(1,4-cyclohexanedimethano 1-1,4-cyclohexanedicarboxylate)
(PCCD), having recurring units of formula (7)
##STR00009##
wherein, as described using formula (6), R.sup.2 is a
1,4-cyclohexanedimethylene group derived from
1,4-cyclohexanedimethanol, and T is a cyclohexane ring derived from
cyclohexanedicarboxylate or a chemical equivalent thereof, and can
comprise the cis-isomer, the trans-isomer, or a combination
comprising at least one of the foregoing isomers.
[0048] The polyesters can be obtained by interfacial polymerization
or melt-process condensation as described above, by solution phase
condensation, or by transesterification polymerization wherein, for
example, a dialkyl ester such as dimethyl terephthalate can be
transesterified with ethylene glycol using acid catalysis, to
generate poly(ethylene terephthalate). It is possible to use a
branched polyester in which a branching agent, for example, a
glycol having three or more hydroxyl groups or a trifunctional or
multifunctional carboxylic acid has been incorporated. Furthermore,
it is sometimes desirable to have various concentrations of acid
and hydroxyl end groups on the polyester, depending on the ultimate
end use of the composition.
[0049] The thermoplastic composition can comprise a
polysiloxane-polycarbonate copolymer, also referred to as a
polysiloxane-polycarbonate. The polysiloxane (also referred to
herein as "polydiorganosiloxane") blocks of the copolymer comprise
repeating siloxane units (also referred to herein as
"diorganosiloxane units") of formula (8):
##STR00010##
wherein each occurrence of R is same or different, and is a
C.sub.1-13 monovalent organic radical. For example, R can
independently be a C.sub.1-13 alkyl group, C.sub.1-13 alkoxy group,
C.sub.2-13 alkenyl group, C.sub.2-13 alkenyloxy group, C.sub.3-6
cycloalkyl group, C.sub.3-6 cycloalkoxy group, C.sub.6-14 aryl
group, C.sub.6-10 aryloxy group, C.sub.7-13 arylalkyl group,
C.sub.7-13 arylalkoxy group, C.sub.7-13 alkylaryl group, or
C.sub.7-13 alkylaryloxy group. The foregoing groups can be fully or
partially halogenated with fluorine, chlorine, bromine, or iodine,
or a combination thereof. Combinations of the foregoing R groups
can be used in the same copolymer.
[0050] The value of D in formula (8) can vary widely depending on
the type and relative amount of each component in the thermoplastic
composition, the desired properties of the composition, and like
considerations. Generally, D can have an average value of 2 to
1,000, specifically 2 to 500, more specifically 5 to 100. In an
embodiment, D has an average value of 30 to 60, specifically 40 to
60. In another embodiment, D has an average value of 45.
[0051] Where D is of a lower value, e.g., less than 40, it can be
desirable to use a relatively larger amount of the
polycarbonate-polysiloxane copolymer. Conversely, where D is of a
higher value, e.g., greater than 40, it can be necessary to use a
relatively lower amount of the polycarbonate-polysiloxane
copolymer.
[0052] A combination of a first and a second (or more)
polysiloxane-polycarbonate copolymer can be used, wherein the
average value of D of the first copolymer is less than the average
value of D of the second copolymer. In one embodiment, the
polydiorganosiloxane blocks are provided by repeating structural
units of formula (9):
##STR00011##
wherein D is as defined above; each R can independently be the same
or different, and is as defined above; and each Ar can
independently be the same or different, and is a substituted or
unsubstituted C.sub.6-30 arylene radical, wherein the bonds are
directly connected to an aromatic moiety. Ar groups in formula (9)
can be derived from a C.sub.6-30 dihydroxyarylene compound, for
example a dihydroxyarylene compound of formula (2), (3), or (5)
above. Combinations comprising at least one of the foregoing
dihydroxyarylene compounds can also be used. Specific examples of
dihydroxyarylene compounds are 1,1-bis(4-hydroxyphenyl) methane,
1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane,
2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane,
1,1-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)n-butane,
2,2-bis(4-hydroxy-1-methylphenyl)propane,
1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenylsulphide),
and 1,1-bis(4-hydroxy-t-butylphenyl)propane. Combinations
comprising at least one of the foregoing dihydroxy compounds can
also be used.
[0053] Units of formula (9) can be derived from the corresponding
dihydroxy compound of formula (10)
##STR00012##
wherein R, Ar, and D are as described above. Compounds of formula
(10) can be obtained by the reaction of a dihydroxyarylene compound
with, for example, an alpha, omega-bisacetoxypolydiorgano siloxane
under phase transfer conditions.
[0054] In another embodiment, polydiorganosiloxane blocks comprise
units of formula (11)
##STR00013##
wherein R and D are as described above, and each occurrence of
R.sup.5 is independently a divalent C.sub.1-30 alkylene, and
wherein the polymerized polysiloxane unit is the reaction residue
of its corresponding dihydroxy compound. In a specific embodiment,
the polydiorganosiloxane blocks are provided by repeating
structural units of formula (12)
##STR00014##
wherein R and D are as defined above. Each R.sup.5 in formula (12)
is independently a divalent C.sub.2-8, aliphatic group. Each M in
formula (12) can be the same or different, and can be a halogen,
cyano, nitro, C.sub.1-8 alkylthio, C.sub.1-8 alkyl, C.sub.2-8
alkoxy, C.sub.2-8, alkenyl, C.sub.3-8 alkenyloxy group, C.sub.3-8
cycloalkyl, C.sub.3-8 cycloalkoxy, C.sub.6-10 aryl, C.sub.6-10
aryloxy, C.sub.7-12 arylalkyl, C.sub.7-12 arylalkoxy, C.sub.7-12
alkylaryl, or C.sub.7-12 alkylaryloxy, wherein each n is
independently 0, 1, 2, 3, or 4.
[0055] In some embodiments, M is bromo or chloro, an alkyl group
such as methyl, ethyl, or propyl, an alkoxy group such as methoxy,
ethoxy, or propoxy, or an aryl group such as phenyl, chlorophenyl,
or tolyl; R.sup.5 is a dimethylene, trimethylene or tetramethylene
group; and R is a C.sub.1-8 alkyl, haloalkyl such as
trifluoropropyl, cyanoalkyl, or aryl such as phenyl, chlorophenyl
or tolyl. In some embodiments, R is methyl, or a mixture of methyl
and trifluoropropyl, or a mixture of methyl and phenyl. In still
another embodiment, M is methoxy, n is one, R.sup.5 is a divalent
C.sub.1-3 aliphatic group, and R is methyl.
[0056] Units of formula (12) can be derived from the corresponding
dihydroxy polydiorganosiloxane (13)
##STR00015##
wherein R, D, M, R.sup.5, and n are as described above. Such
dihydroxy polysiloxanes can be made by effecting a platinum
catalyzed addition between a siloxane hydride of formula (14)
##STR00016##
wherein R and D are as previously defined, and an aliphatically
unsaturated monohydric phenol. Aliphatically unsaturated monohydric
phenols include, for example, eugenol, 2-allylphenol,
4-allyl-2-methylphenol, 4-allyl-2-phenylphenol,
4-allyl-2-bromophenol, 4-allyl-2-t-butoxyphenol,
4-phenyl-2-phenylphenol, 2-methyl-4-propylphenol,
2-allyl-4,6-dimethylphenol, 2-allyl-4-bromo-6-methylphenol,
2-allyl-6-methoxy-4-methylphenol and 2-allyl-4,6-dimethylphenol.
Mixtures comprising at least one of the foregoing can also be
used.
[0057] Polysiloxane-polycarbonates comprise 50 to 99.9 wt % of
carbonate units and 0.1 to 50 wt % siloxane units, based on the
total weight of the polysiloxane-polycarbonate. Specific
polysiloxane-polycarbonate copolymers comprise 90 to 99 wt %,
specifically 75 to 99 wt %, of carbonate units and 1 to 25 wt %,
specifically 1 to 10 wt %, siloxane units. An exemplary
polysiloxane-polycarbonate copolymer can comprise 6 wt % siloxane
units. Another exemplary polysiloxane-polycarbonate comprises 20 wt
% siloxane units. All references to weight percent compositions in
the polysiloxane-polycarbonate are based on the total weight of the
polysiloxane-polycarbonate
[0058] Exemplary polysiloxane-polycarbonates comprise polysiloxane
units derived from dimethylsiloxane units (e.g., formula (11) where
R is methyl), and carbonate units derived from bisphenol A, e.g.,
the dihydroxy compound of formula (3) in which each of A.sup.1 and
A.sup.2 is p-phenylene and Y.sup.1 is isopropylidene.
Polysiloxane-polycarbonates can have a weight average molecular
weight of 2,000 to 100,000 g/mol, specifically 5,000 to 50,000
g/mol. Some specific polysiloxane-polycarbonates have, for example,
a weigh average molecular weight of 15,000 to 45,000 g/mol.
Molecular weights referred to herein are as measured by gel
permeation chromatography using a cross-linked styrene-divinyl
benzene column, at a sample concentration of 1 milligram per
milliliter, and as calibrated with polycarbonate standards.
[0059] A polysiloxane-polycarbonate can have a melt volume flow
rate, measured at 300.degree. C. under a load of 1.2 kg, of 1 to 50
cc/10 min, specifically 2 to 30 cc/10 min. In an embodiment, the
polysiloxane-polycarbonate has a melt volume rate measured at
300.degree. C. under a load of 1.2 kg, of 5 to 15 cc/10 min,
specifically 6 to 14 cc/10 min, and specifically 8 to 12 cc/10 min
mixtures of polysiloxane-polycarbonates of different flow
properties can be used to achieve the overall desired flow
property. In an embodiment, exemplary polysiloxane-polycarbonates
are marketed under the trade name LEXAN.RTM. EXL polycarbonates,
available from SABIC Innovative Plastics (formerly GE
Plastics).
[0060] The thermoplastic composition can further include various
other additives ordinarily incorporated with thermoplastic
compositions of this type, where the additives are selected so as
not to significantly adversely affect the desired properties of the
thermoplastic composition. Mixtures of additives can be used. Such
additives can be mixed at a suitable time during the mixing of the
components for forming the thermoplastic composition.
[0061] Additives contemplated herein include, but are not limited
to, impact modifiers, fillers, colorants including dyes and
pigments, antioxidants, heat stabilizers, light and/or UV light
stabilizers, reinforcing agents, light reflecting agents, surface
effect additives, plasticizers, lubricants, mold release agents,
flame retardants, antistatic agents, anti-drip agents, radiation
(gamma) stabilizers, and the like, or a combination comprising at
least one of the foregoing additives. A combination of additives
can be used, for example a combination of a heat stabilizer, mold
release agent, and ultraviolet light stabilizer. Specifically, a
combination of additives can be used comprising one or more of an
antioxidant such as IRGAPHOS*, pentaerythritol stearate, a
compatibilizer such as JONCRYL* epoxy, a quaternary ammonium
compound such as tetramethyl ammonium hydroxide or tetrabutyl
ammonium hydroxide, and a quaternary phosphonium compound such as
tetrabutyl phosphonium hydroxide or tetrabutyl phosphonium acetate.
In general, the additives are used in the amounts generally known
to be effective. The total amount of additives (other than any
impact modifier, filler, or reinforcing agents) is generally 0.01
to 5 weight %, based on the total weight of the composition. While
it is contemplated that other resins and/or additives can be used
in the thermoplastic compositions described herein, such additives
while desirable in some exemplary embodiments are not
essential.
[0062] The thermoplastic composition can comprise poly(aliphatic
ester)-polycarbonate in an amount of 50 to 100 wt %, based on the
total weight of poly(aliphatic ester)-polycarbonate and any added
polycarbonate. The thermoplastic composition can comprise only
poly(aliphatic ester)-polycarbonate. The thermoplastic composition
can comprise poly(aliphatic ester)-polycarbonate that has been
reactively extruded to form a reaction product. The thermoplastic
composition can comprise a blend of poly(aliphatic
ester)-polycarbonate that has been reactively extruded.
[0063] The thermoplastic composition can comprise a soft block
content (i.e., an alpha, omega C.sub.6-20 dicarboxylic acid ester
unit content) of 0.5 to 10 wt %, specifically 1 to 9 wt %, and more
specifically 3 to 8 wt %, based on the total weight of the
poly(aliphatic ester)-polycarbonate copolymer and any added
polycarbonate.
[0064] The thermoplastic composition can have clarity and light
transmission properties, where a sufficient amount of light with
which to make photometric or fluorometric measurement of specimens
contained within the channels and/or wells of an article made
thereof can pass through the thermoplastic composition.
Thermoplastic composition can have 80 to 100% transmission, more
specifically, 89 to 100% light transmission as determined by ASTM
D1003-11, using 3.2 mm thick plaques. The thermoplastic composition
can also have low haze, specifically 0.001 to 5%, more
specifically, 0.001 to 1% as determined by ASTM D1003-11 using 3.2
mm thick plaques.
[0065] The thermoplastic composition can have an MVR of greater
than or equal to 13 cc/10 min, specifically of 13 to 25 cc/10 min
at 300.degree. C. under a load of 1.2 kg), more specifically of 15
to 22 cc/10 min at 300.degree. C. under a load of 1.2 kg according
to ASTM D1238-10.
[0066] The thermoplastic compositions can further have an HDT of
greater than or equal to 100.degree. C., more specifically of 100
to 140.degree. C. measured at 1.82 mega Pascal (MPa) using
unannealed 3.2 mm plaques according to ASTM D648-07. The
thermoplastic compositions can also have an HDT of greater than or
equal to 115.degree. C., more specifically of 115 to 155.degree. C.
measured at 0.45 MPa using unannealed 3.2 mm plaques according to
ASTM D648-07.
[0067] The thermoplastic compositions can further have a Notched
Izod Impact of 400 to 700 Joules per meter (J/m) or 510 to 650 J/m,
measured at 23.degree. C. using 1/8-inch thick bars (3.18 mm) in
accordance with ASTM D256-10. The thermoplastic compositions can
further have a Notched Izod Impact ductilities of 30 to 100% or 50
to 100%, measured at 23.degree. C. using 1/8-inch thick bars (3.18
mm) in accordance with ASTM D256-10.
[0068] The thermoplastic compositions can have an instrumented
impact energy at peak of 40 to 80 J/m or 50 to 70 J/m, measured at
23.degree. C. in accordance with ASTM D3763-10. The thermoplastic
compositions can have an instrumented impact ductility of 65 to
100% or 85 to 100% measured at 23.degree. C. in accordance with
ASTM D3763-10.
[0069] The thermoplastic compositions can have a tensile or a
flexural modulus of 1500 to 3500 MPa or 2000 to 3000 MPa measured
at 0.2 inches (in)/min (approximately 5.0 mm/min) in accordance
with ASTM D638-10. The thermoplastic compositions can have a
tensile stress at yield of 35 to 100 MPa or 50 to 80 MPa measured
at 0.2 in/min in accordance with ASTM D638-10. The thermoplastic
compositions can have a tensile stress at break of 35 to 100 MPa or
50 to 80 MPa measured at 0.2 in/min in accordance with ASTM
D638-10. The polycarbonate compositions can have a tensile strain
at yield of 2 to 10% or 5 to 8% measured at 0.2 in/min in
accordance with ASTM D638-10. The thermoplastic compositions can
have a tensile strain at break of 85 to 150% or 95 to 110% measured
at 0.2 in/min in accordance with ASTM D638-10.
[0070] Polycarbonates and polyestercarbonates can be manufactured
by processes such as interfacial polymerization and melt
polymerization. Although the reaction conditions for interfacial
polymerization can vary, an exemplary process generally involves
dissolving or dispersing a dihydric phenol reactant in aqueous
caustic soda or potash, adding the resulting mixture to a
water-immiscible solvent medium, and contacting the reactants with
a carbonate precursor in the presence of a catalyst such as, for
example, a tertiary amine or a phase transfer catalyst, under
controlled pH conditions, e.g., 8 to 10. The most commonly used
water immiscible solvents include methylene chloride,
1,2-dichloroethane, chlorobenzene, toluene, and the like.
[0071] Exemplary carbonate precursors include, for example, a
carbonyl halide such as carbonyl bromide or carbonyl chloride, or a
haloformate such as a bishaloformates of a dihydric phenol (e.g.,
the bischloroformates of bisphenol A, hydroquinone, or the like) or
a glycol (e.g., the bishaloformate of ethylene glycol, neopentyl
glycol, polyethylene glycol, or the like). Combinations comprising
at least one of the foregoing types of carbonate precursors can
also be used. In an exemplary embodiment, an interfacial
polymerization reaction to form carbonate linkages uses phosgene as
a carbonate precursor, and is referred to as a phosgenation
reaction.
[0072] Among tertiary amines that can be used are aliphatic
tertiary amines such as triethylamine, tributylamine,
cycloaliphatic amines such as N,N-diethyl-cyclohexylamine and
aromatic tertiary amines such as N,N-dimethylaniline.
[0073] Among the phase transfer catalysts that can be used are
catalysts of the formula (R.sup.3).sub.4Q.sup.+X, wherein each
R.sup.3 is the same or different, and is a C.sub.1-10 alkyl group;
Q is a nitrogen or phosphorus atom; and X is a halogen atom or a
C.sub.1-8 alkoxy group or C.sub.6-18 aryloxy group. Exemplary phase
transfer catalysts include, for example,
[CH.sub.3(CH.sub.2).sub.3].sub.4NX,
[CH.sub.3(CH.sub.2).sub.3].sub.4PX,
[CH.sub.3(CH.sub.2).sub.5].sub.4NX,
[CH.sub.3(CH.sub.2).sub.6].sub.4NX,
[CH.sub.3(CH.sub.2).sub.4].sub.4NX,
CH.sub.3[CH.sub.3(CH.sub.2).sub.3].sub.3NX, and
CH.sub.3[CH.sub.3(CH.sub.2).sub.2].sub.3NX, wherein X is Cl.sup.-,
Br.sup.-, a C.sub.1-8 alkoxy group or a C.sub.6-18 aryloxy group.
An effective amount of a phase transfer catalyst can be 0.1 to 10
weight percent (wt %) based on the weight of bisphenol in the
phosgenation mixture. In another embodiment, an effective amount of
phase transfer catalyst can be 0.5 to 2 wt % based on the weight of
bisphenol in the phosgenation mixture.
[0074] When an interfacial polymerization is used as the
polymerization method, rather than utilizing the dicarboxylic acid
(such as the alpha, omega C.sub.6-20 aliphatic dicarboxylic acid)
per se, it is possible to employ the reactive derivatives of the
dicarboxylic acid, such as the corresponding dicarboxylic acid
halides, and in particular the acid dichlorides and the acid
dibromides. Thus, for example instead of using isophthalic acid,
terephthalic acid, or a combination comprising at least one of the
foregoing (for poly(arylate ester)-polycarbonates), it is possible
to employ isophthaloyl dichloride, terephthaloyl dichloride, and a
combination comprising at least one of the foregoing. Similarly,
for the poly(aliphatic ester)-polycarbonates, it is possible to
use, for example, acid chloride derivatives such as a C.sub.6
dicarboxylic acid chloride (adipoyl chloride), a C.sub.10
dicarboxylic acid chloride (sebacoyl chloride), or a C.sub.12
dicarboxylic acid chloride (dodecanedioyl chloride). The
dicarboxylic acid or reactive derivative can be condensed with the
dihydroxyaromatic compound in a first condensation, followed by in
situ phosgenation to generate the carbonate linkages with the
dihydroxyaromatic compound. Alternatively, the dicarboxylic acid or
derivative can be condensed with the dihydroxyaromatic compound
simultaneously with phosgenation.
[0075] Alternatively, melt processes can be used to make the
polycarbonates. Generally, in the melt polymerization process,
polycarbonates can be prepared by co-reacting, in a molten state,
the dihydroxy reactant(s) and a diaryl carbonate ester, such as
diphenyl carbonate, in the presence of a transesterification
catalyst in a BANBURY* mixer, twin screw extruder, or the like to
form a uniform dispersion. Volatile monohydric phenol is removed
from the molten reactants by distillation and the polymer is
isolated as a molten residue. A specific melt process for making
polycarbonates uses a diaryl carbonate ester having
electron-withdrawing substituents on the aryls. Examples of
specific diaryl carbonate esters with electron withdrawing
substituents include bis(4-nitrophenyl)carbonate,
bis(2-chlorophenyl)carbonate, bis(4-chlorophenyl)carbonate,
bis(methyl salicyl)carbonate, bis(4-methylcarboxylphenyl)carbonate,
bis(2-acetylphenyl)carboxylate, bis(4-acetylphenyl)carboxylate, or
a combination comprising at least one of the foregoing. In
addition, transesterification catalysts for use can include phase
transfer catalysts of formula (R.sup.4).sub.4QA above, wherein each
R.sup.4, Q, and X are as defined above. Examples of
transesterification catalysts include tetrabutylammonium hydroxide,
methyltributylammonium hydroxide, tetrabutylammonium acetate,
tetrabutylphosphonium hydroxide, tetrabutylphosphonium acetate,
tetrabutylphosphonium phenolate, or a combination comprising at
least one of the foregoing.
[0076] All types of polycarbonate end groups are contemplated in
the polycarbonate composition, provided that such end groups do not
significantly adversely affect desired properties of the
compositions.
[0077] Branched polycarbonate blocks can be prepared by adding a
branching agent during polymerization. These branching agents
include polyfunctional organic compounds containing at least three
functional groups selected from hydroxyl, carboxyl, carboxylic
anhydride, haloformyl, and mixtures of the foregoing functional
groups. Specific examples include trimellitic acid, trimellitic
anhydride, trimellitic trichloride, tris-p-hydroxy phenyl ethane,
isatin-bisphenol, tris-phenol TC
(1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene), tris-phenol PA
(4(4(1,1-bis(p-hydroxyphenyl)-ethyl)alpha, alpha-dimethyl benzyl)
phenol), 4-chloroformyl phthalic anhydride, trimesic acid, and
benzophenone tetracarboxylic acid. The branching agents can be
added at a level of 0.05 to 2.0 weight %. Mixtures comprising
linear polycarbonates and branched polycarbonates can be used.
[0078] A chain stopper (also referred to as a capping agent) can be
included during polymerization. The chain stopper limits molecular
weight growth rate, and so controls molecular weight in the
polycarbonate. Exemplary chain stoppers include certain
mono-phenolic compounds, mono-carboxylic acid chlorides, and/or
mono-chloroformates. Mono-phenolic chain stoppers are exemplified
by monocyclic phenols such as phenol and C.sub.1-22
alkyl-substituted phenols such as p-cumyl-phenol, resorcinol
monobenzoate, and p- and tertiary-butyl phenol; and monoethers of
diphenols, such as p-methoxyphenol. Alkyl-substituted phenols with
branched chain alkyl substituents having 8 to 9 carbon atom can be
specifically mentioned. Certain mono-phenolic UV absorbers can also
be used as a capping agent, for example
4-substituted-2-hydroxybenzophenones and their derivatives, aryl
salicylates, monoesters of diphenols such as resorcinol
monobenzoate, 2-(2-hydroxyaryl)-benzotriazoles and their
derivatives, 2-(2-hydroxyaryl)-1,3,5-triazines and their
derivatives, and the like.
[0079] Mono-carboxylic acid chlorides can also be used as chain
stoppers. These include monocyclic, mono-carboxylic acid chlorides
such as benzoyl chloride, C.sub.1-22 alkyl-substituted benzoyl
chloride, toluoyl chloride, halogen-substituted benzoyl chloride,
bromobenzoyl chloride, cinnamoyl chloride, 4-nadimidobenzoyl
chloride, and combinations thereof; polycyclic, mono-carboxylic
acid chlorides such as trimellitic anhydride chloride, and
naphthoyl chloride; and combinations of monocyclic and polycyclic
mono-carboxylic acid chlorides. Chlorides of aliphatic
monocarboxylic acids with less than or equal to 22 carbon atoms are
useful. Functionalized chlorides of aliphatic monocarboxylic acids,
such as acryloyl chloride and methacryoyl chloride, are also
useful. Also useful are monochloroformates including monocyclic,
mono-chloroformates, such as phenyl chloroformate,
alkyl-substituted phenyl chloroformate, p-cumyl phenyl
chloroformate, toluene chloroformate, and combinations thereof.
[0080] Where the melt volume rate of an otherwise compositionally
suitable poly(aliphatic ester)-polycarbonate is not suitably high,
i.e., where the MVR is less than 13 cc/10 min when measured at
250.degree. C., under a load of 1.2 kg, the poly(aliphatic
ester)-polycarbonate can be modified to provide a reaction product
with a higher flow (i.e., greater than or equal to 13 cc/10 min
when measured at 250.degree. C., under a load of 1.2 kg), by
treatment using a redistribution catalyst under conditions of
reactive extrusion. During reactive extrusion, the redistribution
catalyst can be typically included in small amounts of less than or
equal to 400 parts per million (ppm) by weight, by injecting a
dilute aqueous solution of the redistribution catalyst into the
extruder being fed with the poly(aliphatic
ester)-polycarbonate.
[0081] The redistribution catalyst can be tetraalkylphosphonium
hydroxide, tetraalkylphosphonium alkoxide, tetraalkylphosphonium
aryloxide, a tetraalkylphosphonium carbonate, a tetraalkylammonium
hydroxide, a tetraalkylammonium carbonate, a tetraalkylammonium
phosphite, a tetraalkylammonium acetate, or a combination
comprising at least one of the foregoing catalysts, wherein each
alkyl is independently a C.sub.1-6 alkyl. In a specific embodiment,
a redistribution catalyst is a tetra C.sub.1-6 alkylphosphonium
hydroxide, C.sub.1-6 alkyl phosphonium phenoxide, or a combination
comprising one or more of the foregoing catalysts. An exemplary
redistribution catalyst is tetra-n-butylphosphonium hydroxide.
[0082] The redistribution catalyst can be present in an amount of
40 to 120 ppm, specifically 40 to 110 ppm, and more specifically 40
to 100 ppm, by weight based on the weight of the poly(aliphatic
ester)-polycarbonate.
[0083] The thermoplastic compositions described herein can be
molded into shaped articles by for example injection molding (such
as one-shot or two-shot injection molding), extrusion, rotational
molding, blow molding, and thermoforming. Desirably, the
thermoplastic composition has excellent mold filling capability due
to its high flow properties.
[0084] The thermoplastic composition can be manufactured, for
example, by mixing powdered poly(aliphatic ester)-polycarbonate
copolymer, along with an added polycarbonate and/or additives in a
HENSCHEL MIXER* high speed mixer. Other low shear processes
including but not limited to hand mixing can also accomplish this
blending. The blend can then be fed into the throat of an extruder
via a hopper. Alternatively, one or more of the components can be
incorporated into the composition by feeding directly into the
extruder at the throat and/or downstream through a sidestuffer.
Additives can also be compounded into a masterbatch with a desired
polymeric resin and fed into the extruder. The extruder is
generally operated at a temperature higher than that necessary to
cause the composition to flow, but at which temperature components
of the thermoplastic composition do not decompose so as to
significantly adversely affect the composition. The extrudate is
immediately quenched in a water bath and pelletized. The pellets,
so prepared when cutting the extrudate, can be one-fourth inch long
or less as desired. Such pellets can be used for subsequent
molding, shaping, or forming.
[0085] In a specific embodiment, the compounding extruder is a
twin-screw extruder. The extruder is typically operated at a
temperature of 180 to 385.degree. C., specifically 200 to
330.degree. C., more specifically 220 to 300.degree. C., wherein
the die temperature can be different. The extruded thermoplastic
composition is quenched in water and pelletized.
[0086] The thermoplastic compositions can be molded into shaped
articles by a variety of means such as injection molding (such as
one-shot or two-shot injection molding), extrusion, rotational
molding, blow molding, and thermoforming with or without the
application of a vacuum. In some embodiments, the molding can be
done by injection molding. Desirably, the thermoplastic composition
has excellent mold filling capability due to its high flow
properties.
[0087] Products (e.g., articles) made from the thermoplastic
composition(s) can be used in a variety of applications including
thin walled articles, where transparency and ductility retention at
low temperatures are both required or where transparency, precision
as defined by a high degree of reproducibility, retention of
mechanical properties including impact strength, and precise
optical properties are required. Such a blend to provide a
thermoplastic composition would reduce the residual stress in the
molded article due to the improved ductility and the better flow.
Shaped, formed, or molded articles comprising the thermoplastic
compositions are also provided.
[0088] The high melt flow thermoplastic composition polycarbonate
comprises a polyester-polycarbonate copolymer and more specifically
a poly(aliphatic ester)-polycarbonate copolymer. The high melt flow
thermoplastic described herein can therefore be used to make an
article for use in, for example, microfluidic applications such as
PCR applications, etc., wherein the article is exposed at some
point during processing to temperatures of at least 90.degree. C.,
more specifically at least 95.degree. C., and even more
specifically at least 98.degree. C. In some embodiments, the
processing temperature is less than or equal to 120.degree. C.,
more specifically less than or equal to 110.degree. C., even more
specifically less than or equal to 105.degree. C., and even more
specifically less than or equal to 100.degree. C. These upper and
lower limits are independently combinable to form processing
temperature ranges, such as an exemplary processing temperature
range of 95.degree. C. to 105.degree. C., or an exemplary
processing temperature range of 95.degree. C. to 100.degree. C.
during functional usage. Furthermore, the high melt flow
thermoplastic composition can display one or more of optical
clarity, improved modulus, improved room temperature ductility, and
heat resistance.
[0089] The microfluidic device can be used to handle nano and
picoliter fluid volumes. Exemplary microfluidic devices described
herein can be devices that are capable of handling a small amount
of fluid such as less than or equal to 1000 microliters,
specifically 10 picoliters to 1000 microliters, more specifically
50 picoliters to 500 microliters, even more specifically 100
picoliters to 200 microliters. In the case of microwells such as
PCR microwells, exemplary microwell volume capacities can range
from 1 microliter to 1000 microliters, more specifically 10
microliters to 500 microliters, and more specifically 20
microliters to 250 microliters.
[0090] The microfluidic device can be a device for use in
applications where precise control and manipulation of fluids that
are geometrically constrained to a small scale is desired. For
example the microfluidic device can comprise a fabricated dimension
of less than or equal to 1 mm, specifically from 0.005 to 1 mm,
more specifically from 0.01 to 0.5 mm, even more specifically from
0.05 to 0.25 mm.
[0091] The microfluidic device can be used in the field of
molecular biology for enzymatic analysis (such as glucose and
lactate assays), DNA analysis (such as for PCR applications and
high-throughput screening), and proteomics.
[0092] The microfluidic device can be a microfluidic plate and can
be used, for example, in lab-on-chip applications, where one or
more of the following processing steps is integrated onto a single
chip: a pre-treatment step, a preparation step, a mixing step, a
treatment step, a separation step, a reaction step, etc. The
microfluidic plate can be used in continuous flow applications
where fluid continuously flows through at least one channel. The
channel can be a microfabricated channel and the flow can be
achieved by internal forces (such as capillary forces) or by
external forces (such as a pressure source or a mechanical pump).
The channel can have a fabricated dimension as described above,
wherein the dimension is at least one of a width or a depth of the
channel, or a thickness of a wall that forms a boundary of the
channel. The fabricated dimension can be a dimension of less than
or equal to 1 mm, specifically from 0.005 to 1 mm more specifically
from 0.01 to 0.5 mm, even more specifically from 0.05 to 0.25 mm.
The channel can be fabricated by, for example, injection molding,
lithographic techniques, etching, or micromachining. A top view of
an exemplary microfluidic device 100 is depicted in FIG. 1, where a
channel 105 is formed as described above in or on a support 110. In
operation, a process fluid enters the channel 105 at channel inlet
115 and flows through the channel to channel outlet 120.
[0093] The microfluidic device can be a PCR device for use in PCR
applications (such as amplitubes, caps, and microwell plates). The
PCR device can be used to contain small amounts of fluid as
described above and/or can comprise a fabricated dimension of less
than or equal to 1 mm, specifically from 0.005 to 1 mm more
specifically from 0.01 to 0.5 mm, even more specifically from 0.05
to 0.25 mm, wherein the dimension is a wall thickness and the
fabrication step can be a molding step.
[0094] The thermoplastic composition can be used in PCR devices
such as PCR microwells, or in other applications requiring
retention of process materials in microwells. PCR or other
microwell devices can include microwells integrated into a
microwell plate, as well as individual microwells, or rows or racks
of microwells that can be disposed into openings of plates or other
retention devices. The microwells can have various shapes including
pot-shaped, shell-shaped, cup shaped, cone-shaped, tube-shaped, and
the like. The microwells can be cylindrical, spherical,
rectangular, hexangular, conical, and the like. The microwells can
also have different shapes in different sections of the microwell
plate. The microwells can have any suitable configuration including
hexagonal or spherical. An exemplary embodiment of a PCR microwell
plate is illustrated in cross-section view in FIG. 2, where
microwell plate 200 has a plate portion 210 having a number of
microwells attached through openings in plate portion 210. Each
microwell comprises thick wall portion 215, thin wall portion 220,
and cup-shaped bottom portion 225. The details of the attachment of
the microwells to the plate portion are not shown in FIG. 2, but a
number of attachment modalities are known in the art, as described
further in the exemplary disclosure below. The thin wall portion
220 can have a thickness of 0.01 to 0.5 mm, more specifically from
0.05 to 0.25 mm.
[0095] The microwell plate can be designed such that the microwells
do not project beyond the underside or the top side of the plate or
such that they project from the underside and/or top side of the
plate. Microwell plates having microwells that project from the
underside of the plate are particularly suited for use in
thermocyclers for PCR, since the heat exchange can take place
directly between the plate of the thermocycler and the walls of the
wells. When the wells project from the underside of the plate, the
wells can be 3 to 30 mm in diameter and 2 to 15 mm in depth. When
the wells project beyond the top side of the plate, a sealing
attachment of a cover film can directly fit to the upper edges of
the wells. When the wells do not project from the top side of the
plate, the plate has a flat surface such that a cover plate can be
laid on top of the wells to seal them. The cover plate can be made
of any material such as a glass or a thermoplastic and can have
adhesive properties such as pressure sensitive adhesive
properties.
[0096] The plate and the microwells can be one piece or can be
joined together to form one piece. The plate and microwells can be
joined together by injection molding. Alternatively, the plate can
have a plurality of holes, and the wells can be joined to the plate
in one piece by molding onto the edges of the holes. The plate and
microwells can both comprise the high melt flow thermoplastic
composition or the microwells can comprise the high melt flow
thermoplastic composition and the plate can be made of a different
material.
[0097] The microwell plate can further be a laminate structure
wherein one or more layers comprise the high melt flow
thermoplastic composition. The laminate structure can be formed via
coextrusion. A laminate structure can be useful in embodiments
where a gas-barrier layer, a liquid-barrier layer, or the like is
desired or to control the surface properties, for example
hydrophobicity. A laminate structure can also be useful when
reagents, such as those used in PCR techniques, can absorb certain
polymers from the substrate contact with, which potentially reduces
the amount of polymer absorbed and improve reaction yield.
[0098] Further description can be found in U.S. patent application
Ser. No. 61/756,385 filed on Jan. 24, 2013 under attorney docket
number 12PLAS0171-US-PSP, entitled "Microwell Plate", the
disclosure of which is incorporated herein by reference in its
entirety, and in U.S. patent application Ser. No. 61/756,384 filed
on Jan. 24, 2013 under attorney docket number 12PLAS0170-US-PSP,
entitled "Microwell Plate", the disclosure of which is incorporated
herein by reference in its entirety.
[0099] The following examples are provided to illustrate exemplary
embodiments. The examples are merely illustrative and are not
intended to limit devices made in accordance with the disclosure to
the materials, conditions, or process parameters set forth
therein.
EXAMPLES
[0100] Molecular weight determinations were performed using GPC,
using a cross-linked styrene-divinylbenzene column and calibrated
to polycarbonate references. Samples are prepared at a
concentration of 1 mg/mL, and are eluted at a flow rate of 1.0
mL/min.
[0101] MVR was determined at 300.degree. C. or 250.degree. C. using
a 1.2-kilogram weight, in accordance with ASTM 1238-10.
[0102] Izod Notched Impact Strength is used to compare the impact
resistances of plastic materials. Izod Impact was determined using
a 3.2 mm thick, molded Izod notched impact bar per ASTM D
256-10.
[0103] Heat Deflection Temperature (HDT) is also used to compare
heat resistance of plastic materials. Results were determined using
a 3.2 mm thick, molded bar per ASTM D648.
[0104] Tensile properties such as Tensile Strength and Tensile
Elongation to break were determined according to ASTM D 638-10.
[0105] Instrumented impact ductility was determined according to
ASTM D3763-10 at 23.degree. C.
[0106] Specific gravity was determined according to ASTM
D792-08.
[0107] Light transmission and % haze were determined according to
ASTM D1003-11 using 3.2 mm plaques.
Example 1 and Comparative Examples 2 and 3
[0108] Example 1 was prepared from a high melt flow thermoplastic
composition that is 6.0 mole (mol) % sebacic acid and 94.0 mol %
bisphenol-A with a molecular weight of 17,000 g/mol and a glass
transition temperature of 135.degree. C. Comparative Examples 2 and
3 comprise standard polycarbonate materials, PC-65 and PC-100,
respectively, where PC-65 is a linear BPA polycarbonate with a
molecular weight of 17,000 g/mol and PC-100 is a linear BPA
polycarbonate with a molecular weight of 15,000 g/mol. The
compositions of Example 1 and Comparative Examples 2 and 3 were
prepared using a 30 mm co-rotating twin screw (Werner &
Pfleiderer; ZSK-30) extruder using a melt temperature of
300.degree. C. with a rate of 20 kg/hour (hr), 20 inches of mercury
vacuum, and a screw speed of 400 RPM. In the case of Example 1 the
IRGAPHOS solution was fed into the extruder using a separate liquid
pump feeder. The extrudate was cooled under water, pelletized and
dried at 120.degree. C. for 4 hours with a desiccant bed dryer. To
make test specimens, the dried pellets were injection molded using
a Van Dorn 80T molding machine at 300.degree. C. melt temperature
to form test parts for impact and mechanical testing. The physical
and mechanical properties of Example 1 and Comparative Examples 2
and 3 are shown in Table 2, where pph is parts per hundred
resin.
TABLE-US-00002 TABLE 2 Comparative Comparative Example 1 Example 2
Example 3 Material HFD Low M.sub.w Copolymer 100 0 0 Polycarbonate
17,000 M.sub.w (PC-65) 0 100 0 Polycarbonate 15,000 M.sub.w
(PC-100) 0 0 100 pph pph pph IRGAPHOS 168 0.06 0.06 0.06 PETS 0.20
0.20 0.20 JONCRYL ADR4368CS epoxy 0.10 0.10 0.10 Tetrabutyl
phosphonium hydroxide, 40% 0.029 0 0 solution in water Mechanical
Tensile Modulus, 0.2 in/min MPa 2340 2390 ** Tensile Stress, yield,
Type 1, MPa 53 59 ** 0.2 in/min Tensile Stress, break, Type MPa 52
52 ** 1, 0.2 in/min Tensile Strain, yield, Type 1, % 5.5 5.5 ** 0.2
in/min Tensile Strain, break, Type % 101 83 ** 1, 0.2 in/min Impact
Izod impact, notched 23.degree. C. J/m 596 500 ** Izod impact,
notched 23.degree. C., % 100 20 ** % ductile Instrumented impact
Energy J 62 34 ** @ peak, 23.degree. C. Instrumented impact,
23.degree. C., % 100 60 ** % ductile Physical Specific Gravity --
1.20 1.20 1.20 Melt Flow Rate, 300.degree. C. cm.sup.3/10 min 94 61
94 Melt Flow Rate, 250.degree. C. cm.sup.3/10 min 17.9 10.4 17.9
Thermal HDT, 0.45 MPa, 3.2 mm, .degree. C. 117 135 ** unannealed
HDT, 1.82 MPa, 3.2 mm, .degree. C. 103 124 ** unannealed Optical
Light Transmission, 3.2 mm % 89 89 ** % Haze, 3.2 mm % <1 <1
** ** material too brittle-unable to mold proper test bars without
cracking/shattering
[0109] As can be seen from Table 2, Example 1 resulted in a
polycarbonate composition with improved impact and thermal
properties as compared to the polycarbonate of Comparative Examples
2 and 3, where Comparative Example 3 resulted in a material that
was too brittle and was therefore unable to mold proper test bars
without cracking or shattering. The improved melt flow rates at 300
and 250.degree. C. of 100 and 19 g/10 min, respectively, of the
polycarbonate composition used in Example 1 allows for the
composition to produce microfluidic articles, including microwells,
with wall thicknesses of 0.20 mm, whereas the lesser melt flow
rates at 300 and 250.degree. C. of 65 and 11 g/10 min,
respectively, of the polycarbonate of Comparative Example 2 does
not allow for the composition to have sufficient flow to fill a
0.20 mm thickness PCR tray tool.
Example 1 and Comparative Example 4
[0110] The polycarbonate composition used to make Example 1 was
compared to a typical polypropylene used in commercial microwell
production, PD702 from LYONDELL BASELL (Comparative Example 4) as
shown in Table 3.
TABLE-US-00003 TABLE 3 Comparative Example 1 Example 4 Mechanical
Flexural modulus, 0.2 in/min MPa 2340 1170 Tensile Stress, yield,
Type 1, MPa 53 31.7 0.2 in/min Impact Izod impact, notched
23.degree. C. J/m 596 32.0 Izod impact, notched % 100 0 23.degree.
C., % ductile Physical Specific Gravity -- 1.20 0.902 Melt Flow
Rate, 300.degree. C., cm.sup.3/10 min 94 -- 1.2 kgf Melt Flow Rate,
250.degree. C., cm.sup.3/10 min 17.9 -- 1.2 kgf Melt Flow Rate,
230.degree. C., cm.sup.3/10 min 13.7 35 1.2 kgf Rockwell hardness
(R-scale) -- 120 89 Thermal HDT, 0.45 MPa, 3.2 mm, .degree. C. 117
95 unannealed
[0111] Table 3 shows that the polycarbonate of Example 1 has
superior impact properties, stiffness values, as well as improved
heat deformation values as compared to the polypropylene sample of
Comparative Example 4.
[0112] All ranges disclosed herein are inclusive of the endpoints,
and the endpoints are independently combinable with each other
(e.g., ranges of "up to 25 wt. %, or, more specifically, 5 wt. % to
20 wt. %", is inclusive of the endpoints and all intermediate
values of the ranges of "5 wt. % to 25 wt. %," etc.). "Combination"
is inclusive of blends, mixtures, alloys, reaction products, and
the like. Furthermore, the terms "first," "second," and the like,
herein do not denote any order, quantity, or importance, but rather
are used to denote one element from another. The terms "a" and "an"
and "the" herein do not denote a limitation of quantity, and are to
be construed to cover both the singular and the plural, unless
otherwise indicated herein or clearly contradicted by context. The
suffix "(s)" as used herein is intended to include both the
singular and the plural of the term that it modifies, thereby
including one or more of that term (e.g., the film(s) includes one
or more films). Reference throughout the specification to "one
embodiment", "another embodiment", "an embodiment", and so forth,
means that a particular element (e.g., feature, structure, and/or
characteristic) described in connection with the embodiment is
included in at least one embodiment described herein, and can or
cannot be present in other embodiments. In addition, it is to be
understood that the described elements can be combined in any
suitable manner in the various embodiments.
[0113] The terms "bottom", and/or "top" are used herein, unless
otherwise noted, merely for convenience of description, and are not
limited to any one position or spatial orientation.
[0114] The endpoints of all ranges directed to the same component
or property are inclusive and independently combinable (e.g.,
ranges of "less than or equal to 25 weight %, or 5 weight % to 20
weight %," is inclusive of the endpoints and all intermediate
values of the ranges of "5 weight % to 25 weight %," etc.).
[0115] As used herein, the term "hydrocarbyl" and "hydrocarbon"
refers broadly to a substituent comprising carbon and hydrogen,
optionally with 1 to 3 heteroatoms, for example, oxygen, nitrogen,
halogen, silicon, sulfur, or a combination thereof; "alkyl" refers
to a straight or branched chain, saturated monovalent hydrocarbon
group; "alkylene" refers to a straight or branched chain,
saturated, divalent hydrocarbon group; "alkylidene" refers to a
straight or branched chain, saturated divalent hydrocarbon group,
with both valences on a single common carbon atom; "alkenyl" refers
to a straight or branched chain monovalent hydrocarbon group having
at least two carbons joined by a carbon-carbon double bond;
"cycloalkyl" refers to a non-aromatic monovalent monocyclic or
multicylic hydrocarbon group having at least three carbon atoms,
"cycloalkenyl" refers to a non-aromatic cyclic divalent hydrocarbon
group having at least three carbon atoms, with at least one degree
of unsaturation; "aryl" refers to an aromatic monovalent group
containing only carbon in the aromatic ring or rings; "arylene"
refers to an aromatic divalent group containing only carbon in the
aromatic ring or rings; "alkylaryl" refers to an aryl group that
has been substituted with an alkyl group as defined above, with
4-methylphenyl being an exemplary alkylaryl group; "arylalkyl"
refers to an alkyl group that has been substituted with an aryl
group as defined above, with benzyl being an exemplary arylalkyl
group; "acyl" refers to an alkyl group as defined above with the
indicated number of carbon atoms attached through a carbonyl carbon
bridge (--C(.dbd.O)--); "alkoxy" refers to an alkyl group as
defined above with the indicated number of carbon atoms attached
through an oxygen bridge (--O--); and "aryloxy" refers to an aryl
group as defined above with the indicated number of carbon atoms
attached through an oxygen bridge (--O--).
[0116] Unless otherwise indicated, each of the foregoing groups can
be unsubstituted or substituted, provided that the substitution
does not significantly adversely affect synthesis, stability, or
use of the compound. The term "substituted" as used herein means
that at least one hydrogen on the designated atom or group is
replaced with another group, provided that the designated atom's
normal valence is not exceeded. When the substituent is oxo (i.e.,
.dbd.O), then two hydrogens on the atom are replaced. Combinations
of substituents and/or variables are permissible provided that the
substitutions do not significantly adversely affect synthesis or
use of the compound. Exemplary groups that can be present on a
"substituted" position include, but are not limited to, cyano;
hydroxyl; nitro; azido; alkanoyl (such as a C.sub.2-6 alkanoyl
group such as acyl); carboxamido; C.sub.1-6 or C.sub.1-3 alkyl,
cycloalkyl, alkenyl, and alkynyl (including groups having at least
one unsaturated linkages and from 2 to 8, or 2 to 6 carbon atoms);
C.sub.1-6 or C.sub.1-3 alkoxy groups; C.sub.6-10 aryloxy such as
phenoxy; C.sub.1-6 alkylthio; C.sub.1-6 or C.sub.1-3 alkylsulfinyl;
C.sub.1-6 or C.sub.1-3 alkylsulfonyl; aminodi(C.sub.1-6 or
C.sub.1-3)alkyl; C.sub.6-12 aryl having at least one aromatic rings
(e.g., phenyl, biphenyl, naphthyl, or the like, each ring either
substituted or unsubstituted aromatic); C.sub.7-19 alkylenearyl
having 1 to 3 separate or fused rings and from 6 to 18 ring carbon
atoms, with benzyl being an exemplary arylalkyl group; or
arylalkoxy having 1 to 3 separate or fused rings and from 6 to 18
ring carbon atoms, with benzyloxy being an exemplary arylalkoxy
group.
[0117] All cited patents, patent applications, and other references
are incorporated herein by reference in their entirety. However, if
a term in the present application contradicts or conflicts with a
term in the incorporated reference, the term from the present
application takes precedence over the conflicting term from the
incorporated reference.
[0118] While the disclosure has been described with reference to an
exemplary embodiment, it will be understood by those skilled in the
art that various changes can be made and equivalents can be
substituted for elements thereof without departing from the scope
of the disclosure. In addition, many modifications can be made to
adapt a particular situation or material to the teachings of the
disclosure without departing from the essential scope thereof.
Therefore, it is intended that the disclosure not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this disclosure, but that the disclosure will include
all embodiments falling within the scope of the appended
claims.
* * * * *