U.S. patent application number 13/370683 was filed with the patent office on 2012-06-07 for waterborne, radiation-curable coating compositions and related methods.
This patent application is currently assigned to PPG Industries Ohio, Inc.. Invention is credited to M. Lisa Perrine.
Application Number | 20120142818 13/370683 |
Document ID | / |
Family ID | 39310906 |
Filed Date | 2012-06-07 |
United States Patent
Application |
20120142818 |
Kind Code |
A1 |
Perrine; M. Lisa |
June 7, 2012 |
WATERBORNE, RADIATION-CURABLE COATING COMPOSITIONS AND RELATED
METHODS
Abstract
Disclosed are waterborne, radiation-curable coating
compositions. These coating compositions include a
water-dispersible polymer and a hydrophobic multi-functional
ethylenically unsaturated compound. The compositions are
characterized by being viscosity stable at elevated temperatures
and alkaline conditions.
Inventors: |
Perrine; M. Lisa; (Allison
Park, PA) |
Assignee: |
PPG Industries Ohio, Inc.
Cleveland
OH
|
Family ID: |
39310906 |
Appl. No.: |
13/370683 |
Filed: |
February 10, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11562069 |
Nov 21, 2006 |
8138262 |
|
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13370683 |
|
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Current U.S.
Class: |
523/400 ;
524/500; 524/502; 524/538 |
Current CPC
Class: |
C09D 133/08 20130101;
C08K 5/0025 20130101; C08F 8/44 20130101; C08F 265/06 20130101;
C09D 4/06 20130101; C09D 4/06 20130101; C08F 265/06 20130101; C08F
265/06 20130101; C08F 222/1006 20130101 |
Class at
Publication: |
523/400 ;
524/502; 524/538; 524/500 |
International
Class: |
C09D 163/00 20060101
C09D163/00; C09D 175/04 20060101 C09D175/04; C09D 123/02 20060101
C09D123/02; C09D 177/00 20060101 C09D177/00; C09D 157/00 20060101
C09D157/00; C09D 133/00 20060101 C09D133/00 |
Claims
1. A waterborne coating composition comprising: a
water-dispersible, acid-functional polymer neutralized by a
neutralizing agent comprising a monofunctional tertiary amine
having a pK.sub.a of no more than 9.5, wherein the neutralizing
agent comprises at least 50 percent by weight of total amine in the
composition; and a hydrophobic multi-functional ethylenically
unsaturated compound; wherein the composition has an initial
viscosity of 100 to 300 centipoises at 77.degree. F. and a final
viscosity of 100 to 450 centipoises at 77.degree. F. after exposure
to a temperature of 120.degree. F. for a period of 28 days; and
wherein the composition is curable by exposure to ultraviolet
radiation or electron beam radiation.
2. The waterborne coating composition of claim 1, wherein the
composition comprises a carrier fluid comprising at least 80 weight
percent water.
3. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer comprises a vinyl
polymer, acrylic polymer, polyolefin, epoxy, polyamide, and/or
polyurethane.
4. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer comprises a carboxylic
acid-functional polymer.
5. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer comprises a vinyl
polymer.
6. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer comprises a carboxylic
acid-functional vinyl polymer.
7. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer comprises an acrylic
polymer.
8. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer comprises a carboxylic
acid-functional acrylic polymer.
9. The waterborne coating composition of claim 1, wherein the
water-dispersible, acid-functional polymer has an acid number of 15
to 50.
10. The waterborne coating composition of claim 1, wherein the
composition comprises from 5 percent to 50 percent of the
water-dispersible, acid-functional polymer by weight based on the
total weight of the composition.
11. The waterborne coating composition of claim 1, wherein the
hydrophobic multi-functional ethylenically unsaturated compound
comprises three or more sites of ethylenic unsaturation per
molecule.
12. The waterborne coating composition of claim 10, wherein the
hydrophobic multi-functional ethylenically unsaturated compound
comprises trimethylolpropane tri(meth)acrylate.
13. The waterborne coating composition of claim 1, wherein the
composition comprises from 2 percent to 30 percent of the
hydrophobic multi-functional ethylenically unsaturated compound by
weight based on the total weight of the composition.
14. The waterborne coating composition of claim 1, wherein the
coating composition has a pH of 7 to 9.
15. The waterborne coating composition of claim 1, wherein the
monofunctional tertiary amine has a pK.sub.a of no more than
8.0.
16. A waterborne coating composition comprising: (a) a carrier
fluid comprising at least 80 weight percent water; (b) 5 percent to
50 percent by weight based on the total weight of the composition
of a carboxylic acid-functional acrylic polymer; (c) a neutralizing
agent comprising a monofunctional tertiary amine having a pK.sub.a
of no more than 9.5, wherein the neutralizing agent comprises at
least 50 percent by weight of total amine in the composition, and
wherein the carboxylic acid-functional acrylic polymer is
neutralized by the monofunctional tertiary amine; and (d) 2 percent
to 30 percent by weight based on the total weight of the
composition of a hydrophobic multi-functional ethylenically
unsaturated compound comprising three or more sites of ethylenic
unsaturation per molecule; wherein the composition has an initial
viscosity of 100 to 300 centipoises at 77.degree. F. and a final
viscosity of 100 to 450 centipoises at 77.degree. F. after exposure
to a temperature of 120.degree. F. for a period of 28 days; wherein
the coating composition has a pH of 7 to 9; and wherein the
composition is curable by exposure to ultraviolet radiation or
electron beam radiation.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/562,069 filed Nov. 21, 2006, entitled:
"Waterborne, Radiation-curable Coating Compositions and Related
Methods"
FIELD OF THE INVENTION
[0002] The present invention relates to waterborne,
radiation-curable coating compositions. These coating compositions
comprise a water dispersible polymer and a hydrophobic
multi-functional ethylenically unsaturated compound and are
characterized by being viscosity stable at elevated temperatures
and alkaline conditions.
BACKGROUND INFORMATION
[0003] Thermally cured solvent-based and water-based coatings have
been widely available. A disadvantage of solvent-based coatings is
a high VOC (volatile organic compound) content compared to
water-based coatings. Additionally, both solvent-based and
water-based thermal cure coatings, as compared to ultraviolet
("UV") light curable coatings, can have slow rates of cure, due, in
at least some cases, to a slow rate of reaction for the
crosslinkers that are used. UV-curable systems often provide a much
faster reaction because a UV light with certain frequencies is used
to form radicals from a photoinitiator that crosslinks the vinyl
groups on the resin. The UV light curing reaction can take place
within a few seconds as opposed to a thermal curing reaction that
can take significantly longer, including several minutes or
more.
[0004] UV-curable, water-based coatings can be used in some cases.
Often, in addition to radiation curable materials, these coatings
often include a water dispersible polymer, such as an acid
functional acrylic or polyester, which is neutralized in water with
an amine Because little or no heat is required to cure a UV-curable
water-based coating, they can be applied to heat sensitive
substrates, such as cellulosics and plastics.
[0005] One disadvantage that has been associated with UV-curable,
water-based coating compositions is that they often exhibit poor pH
and viscosity stability under the alkaline conditions that are
often desirable or necessary. Often, under these conditions, the
radiation curable materials, such as multi-functional
(meth)acrylates, that are present hydrolyze in the presence of
water, which leads to an undesired increase in the viscosity of the
composition over time.
[0006] As a result, it would be desirable to provide waterborne,
radiation-curable coating compositions that are viscosity stable
under alkaline conditions.
SUMMARY OF THE INVENTION
[0007] In certain respects, the present invention is directed to
waterborne, radiation-curable coating compositions. These
compositions comprise (a) a water dispersible polymer; (b) a
hydrophobic multi-functional ethylenically unsaturated compound;
and (c) a neutralizing agent comprising predominantly a
monofunctional tertiary amine having a pK.sub.a of no more than
9.5.
[0008] In other respects, the present invention is directed to
waterborne, radiation curable coating compositions comprising an
acid functional polymer and a hydrophobic multi-functional
ethylenically unsaturated compound, wherein the composition is
viscosity stable for at least 28 days at 120.degree. F. when
neutralized to a pH of from 7 to 9.
DETAILED DESCRIPTION OF THE INVENTION
[0009] For purposes of the following detailed description, it is to
be understood that the invention may assume various alternative
variations and step sequences, except where expressly specified to
the contrary. Moreover, other than in any operating examples, or
where otherwise indicated, all numbers expressing, for example,
quantities of ingredients used in the specification and claims are
to be understood as being modified in all instances by the term
"about". Accordingly, unless indicated to the contrary, the
numerical parameters set forth in the following specification and
attached claims are approximations that may vary depending upon the
desired properties to be obtained by the present invention. At the
very least, and not as an attempt to limit the application of the
doctrine of equivalents to the scope of the claims, each numerical
parameter should at least be construed in light of the number of
reported significant digits and by applying ordinary rounding
techniques.
[0010] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard variation found in their respective testing
measurements.
[0011] Also, it should be understood that any numerical range
recited herein is intended to include all sub-ranges subsumed
therein. For example, a range of "1 to 10" is intended to include
all sub-ranges between (and including) the recited minimum value of
1 and the recited maximum value of 10, that is, having a minimum
value equal to or greater than 1 and a maximum value of equal to or
less than 10.
[0012] In this application, the use of the singular includes the
plural and plural encompasses singular, unless specifically stated
otherwise. In addition, in this application, the use of "or" means
"and/or" unless specifically stated otherwise, even though "and/or"
may be explicitly used in certain instances.
[0013] As previously mentioned, certain embodiments of the present
invention are directed to "waterborne" coating compositions. As
used herein, the term "waterborne" coating composition refers to
compositions wherein the solvent or carrier fluid primarily or
principally comprises water. For example, in certain embodiments of
the present invention, the carrier fluid is at least 80 weight
percent water. In certain embodiments, in addition to water, the
aqueous medium may further comprise an organic solvent, such as,
for example, alcohols with up to about 8 carbon atoms, such as
methanol, isopropanol, and the like; or glycol ethers, such as the
monoalkyl ethers of ethylene glycol, diethylene glycol, or
propylene glycol, and the like. When present, organic solvents are
typically used in amounts up to about ten percent by volume, based
on the total volume of aqueous medium.
[0014] In addition, certain embodiments of the present invention
are directed to coating compositions that are "low VOC" coating
compositions. As used herein, the term "low VOC composition" means
that the composition contains no more than three (3) pounds of
volatile organic compounds per gallon of the composition. In
certain embodiments, the coating compositions of the present
invention comprise no more than one (1) pound of volatile organic
compound per gallon of the coating composition. As used herein, the
term "volatile organic compound" refers to compounds that have at
least one carbon atom and which are released from the composition
during drying and/or curing thereof. Examples of "volatile organic
compounds" include, but are not limited to, alcohols, benzenes,
toluenes, chloroforms, and cyclohexanes.
[0015] As also indicated, the waterborne coating compositions of
the present invention are "radiation-curable". As used herein, the
term "radiation-curable" refers to compositions that include a
compound having reactive components that are polymerizable by
exposure to an energy source, such as an electron beam (EB), UV
light, or visible light. Examples of radiation curable compounds
include those that contain ethylenic unsaturation, such as acrylate
or methacrylate groups, fumarate groups, vinyl ether groups,
maleate groups, thiol groups, alkenes, epoxies and the like.
[0016] As previously indicated, the waterborne, radiation-curable
coating compositions of the present invention comprise a water
dispersible polymer. As used herein, the term "water dispersible
polymer" refers to a polymer than is capable of being stably
dispersed in water with or without the aid or use of a surfactant.
In certain embodiments, the water dispersible polymer utilized in
the coating compositions of the present invention is capable of
being stably dispersed in water without the aid or use of a
significant amount, i.e., no more than 1 percent by weight based on
the weight of the polymer, of surfactant.
[0017] Suitable water dispersible polymers include polyurethanes,
epoxies, polyamides, chlorinated polyolefins, acrylics,
oil-modified polymers, as well as mixtures or copolymers thereof.
Such polymers can be readily synthesized and made to be water
dispersible using conventional techniques. In certain embodiments,
for example, the incorporation of acid functionality produces water
dispersibility. As a result, in certain embodiments, the water
dispersible polymer included in the compositions of the present
invention comprises an acid functional polymer.
[0018] The acid functionality incorporated onto such polymers is,
in certain embodiments, carboxylic acid, though, in other
embodiments, other acids, such as sulfonic acid, may be used. In
certain embodiments, the acid functional polymer has at least two
carboxyl groups per molecule.
[0019] Suitable acid functional polymers include, but are not
limited to, acid functional acrylic polymers, polyolefins, epoxies,
polyamides, and polyurethanes, including mixtures thereof. In
certain embodiments, the acid functional polymer included in the
coating compositions of the present invention has an acid number of
from 5 to 50, such as 5 to 30.
[0020] Carboxylic acid-functional acrylic polymers that are
suitable for use in the present invention can be prepared by free
radical polymerization methods that are known to those of ordinary
skill in the art. In certain embodiments, such a polymer is
prepared by polymerizing one or more carboxylic acid functional
ethylenically unsaturated monomers, e.g., (meth)acrylic acid, with
one or more ethylenically unsaturated monomers that are free of
carboxylic acid functionality, e.g., methyl (meth)acrylate,
isobornyl (meth)acrylate, butyl (meth)acrylate and styrene.
Alternatively, such a carboxylic acid functional acrylic polymer
may be prepared by first preparing a hydroxy functional acrylic
polymer that is then reacted with a cyclic anhydride, e.g.,
succinic anhydride. Additionally suitable ethylenically unsaturated
monomers are functional monomers that can supply crosslinking
moieties for thermosetting polymers, such as acrylic acid,
methacrylic acid, and hydroxy functional acrylates and
methacrylates, such as hydroxyethyl acrylate, hydroxyethyl
methacrylate, hydroxypropyl acrylate, and hydroxypropyl
methacrylate.
[0021] In certain embodiments, the coating compositions of the
present invention comprise a self-crosslinking acrylic polymer,
such as an acrylic polymer with acetoacetoxy-type functional
moieties, as described, for example, in United States Patent
Application Publication No. 2005/0176874A1 at [0001] to [0049], the
cited portion of which being incorporated herein by reference.
[0022] Acid functional acrylic polymers can, for example, be
prepared by solution polymerization techniques known to those
skilled in the art. Generally, the monomer(s) are polymerized in
the presence of a suitable free radical initiating catalyst, such
as an organic peroxide or azo compound, for example benzoyl
peroxide, t-butyl perbenzoate, or N,N'-azobis-(isobutyronitrile).
The amount of catalyst can vary widely depending upon the
particular polymerization conditions. In certain embodiments, the
monomer(s) are polymerized in the presence of an organic solvent
such as an alcohol, an aromatic solvent, a ketone, and/or a glycol.
The solvent(s) are selected such that they solubilize the monomers
and can be readily removed by distillation at the completion of the
polymerization.
[0023] Polyurethanes having carboxylic acid functionality are also
suitable for use in the present invention and can be prepared, as
will be appreciated by those skilled in the art, by reacting one or
more isocyanates with one or more hydroxy-functional compounds.
Suitable water-dispersible polyurethanes, and methods for their
preparation, are described in United States Published Patent
Application No. 2005/0192400A1 at to [0047] and [0055], the cited
portion of which being incorporated herein by reference.
[0024] Polyesters having carboxylic acid functionality may, in
certain embodiments, also be suitable for use in the present
invention and may be prepared by art-recognized methods, which
include reacting carboxylic acids (and/or esters thereof) having
acid (or ester) functionalities of at least 2, and polyols having
hydroxy functionalities of at least 2. As is known to those of
ordinary skill in the art, the molar equivalents ratio of
carboxylic acid groups to hydroxy groups of the reactants is
selected such that the resulting polyester has carboxylic acid
functionality and the desired molecular weight.
[0025] In certain embodiments, the acid functional polymer is
present in the coating compositions of the present invention in an
amount of from 5 percent to 50 percent by weight, such as 7 to 40
percent by weight, with the weight percent being based on the total
weight of the coating composition.
[0026] As previously indicated, the waterborne coating compositions
of the present invention also comprise a hydrophobic
multi-functional ethylenically unsaturated compound. As used
herein, the term "hydrophobic ethylenically unsaturated compound"
refers to ethylenically unsaturated compounds that are essentially
not compatible with, do not have an affinity for, and/or are not
capable of dissolving in water using conventional mixing means.
That is, upon mixing a sample of the compound with an organic
component and water, a majority of the polymer is in the organic
phase and a separate aqueous phase is observed. See Hawley's
Condensed Chemical Dictionary, (12th Ed. 1993) at page 618.
[0027] As used herein, the term "multi-functional ethylenically
unsaturated compound" refers to compounds containing two or more
sites of ethylenic unsaturation per molecule. Specific examples of
which include, but are not limited to, bifunctional ethylenically
unsaturated compounds, which contain two sites of ethylenic
unsaturation per molecule, trifunctional ethylenically unsaturated
compounds, which contain three sites of ethylenic unsaturation per
molecule, tetrafunctional ethylenically unsaturated compounds,
which contain four sites of ethylenic unsaturation per molecule,
and pentafunctional ethylenically unsaturated compounds, which
contain five sites of ethylenic unsaturation per molecule. As will
be appreciated, mixtures of two or more hydrophobic
multi-functional ethylenically unsaturated compounds may be used in
the compositions of the present invention.
[0028] Specific examples of hydrophobic bifunctional ethylenically
unsaturated compounds, which are suitable for use in the present
invention, include, without limitation, 1,3-butylene glycol
di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol
di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A
glycidyl di(meth)acrylate, ethylene oxide-modified bisphenol A
di(meth)acrylate, ethylene oxide-modified bisphenol A glycidyl
di(meth)acrylate, 2,2-bis(4-methacryloxypropoxyphenyl)propane,
7,7,9-trimethyl-4,13-dioxa-3,14-dioxo-5,12-diazahexadecane-1,1,6-diol
di(meth)acrylate, neopentyl glycol hydroxypivalate
di(meth)acrylate, caprolactone-modified neopentyl glycol
hydroxypivalate di(meth)acrylate, trimethylolethane
di(meth)acrylate, trimethylolpropane di(meth)acrylate, and the
like.
[0029] Specific examples of hydrophobic trifunctional or higher
polyfunctional ethylenically unsaturated compounds that are
suitable for use in the present invention include, but are not
limited to, trimethylolmethane tri(meth)acrylate, trimethylolethane
tri(meth)acrylate, trimethylolpropane tri(meth)acrylate,
pentaerythritol tri(meth)acrylate, dipentaerythritol
tri(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate,
pentaerythritol tetra(meth)acrylate, dipentaerythritol
tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the
like.
[0030] In certain embodiments, the coating compositions of the
present invention are substantially free, or, in some cases,
completely free of monofunctional acrylates. As used herein, the
term "monofunctional acrylate" refers to a molecule having one
acrylate moiety. As used herein, the term "substantially free"
means that the material being discussed is present in a
composition, if at all, as an incidental impurity. In other words,
the material does not affect the viscosity stability properties of
the composition of the present invention. As used herein, the term
"completely free" means that the material being discussed is not
present in a composition at all.
[0031] In certain embodiments, the hydrophobic multi-functional
ethylenically unsaturated compound is present in the coating
compositions of the present invention in an amount of from 2
percent to 30 percent by weight, such as 5 to 15 percent by weight,
with the weight percent being based on the total weight of the
coating composition.
[0032] Certain embodiments of the waterborne coating compositions
of the present invention also comprise a neutralizing agent
comprising predominantly a monofunctional tertiary amine having a
base strength, pK.sub.a, of no more than 9.5, in some cases, no
more than 8.5, and, in yet other cases, no more than 8.0. As used
herein, when it is stated that the neutralizing agent comprises
"predominantly" a monofunctional tertiary amine, it means that the
amount of monofunctional tertiary amine used to solubilize the acid
functional polymer is sufficient to produce a composition that is
viscosity stable under alkaline conditions. In certain embodiments,
this means that at least 50 percent by weight, in some cases at
least 75 percent by weight, or, in yet other cases, at least 90
percent by weight, of the total amine in the composition is a
monofunctional tertiary amine having a pK.sub.a of no more than
9.5.
[0033] Monofunctional tertiary amines having a pKa within the
desired range, which are suitable for use in the present invention,
include, but are not necessarily limited to, triallylamine,
diallylmethylamine, benzyldimethylamine, n-allylmorpholine,
propargyldimethylamine, propargylethyldimethylamine,
n-methylmorpholine, n,n-dimethylhydroxylamine, allyldimethylamine,
benzyldiethylamine, n-ethylmorpholine, propargymethyldimethylamine,
including mixtures thereof.
[0034] In the compositions of the present invention, the
neutralizing agent is present in an amount sufficient to neutralize
the coating composition to a pH within the range of 7 to 9, such as
7.0 to 8.7, or, in some cases, 7.5 to 8.7.
[0035] The inventors have surprisingly discovered that the
waterborne, radiation-curable compositions described herein are
viscosity stable under alkaline conditions. As used herein, the
term "alkaline conditions" means that the pH of the composition is
within the range of 7 to 9, in some cases 7.5 to 8.7. As used
herein, the term "viscosity stable" means that the viscosity of the
composition does not increase by more than 50% of its original
viscosity, in some cases not more than 25%, after being exposed to
a temperature of 120.degree. F. for a period of 28 days.
[0036] In certain embodiments, the initial viscosity of the
composition is 100 to 300 centipoises (cps), such as 120 to 200
cps, at 77.degree. F. (25.degree. C.) and the final viscosity is
100 to 450 cps, such as 120 to 300 cps, at 77.degree. F.
(25.degree. C.). As used herein, the term "final viscosity" refers
to the viscosity of the composition after the composition has been
exposed to a temperature of 120.degree. F. for a period of 28 days.
The viscosity values reported herein are measured according to the
method described in the Examples.
[0037] In addition to the previously described components, the
compositions of the present invention may include other components,
such as, for example, free radical photoinitiators. Suitable free
radical photoinitiators include, but are not limited to,
benzophenones, acetophenone derivatives, such as
alpha-hydroxyalkylphenylketones, benzoins such as benzoin alkyl
ethers and benzyl ketals, monoacylphosphine oxides, and
bisacylphosphine oxides. Free radical initiators are commercially
available from, for example, Ciba Specialty Chemicals Corporation
in their DURACURE and IRGACURE lines; IRGACURE 184, IRGACURE 500,
and DURACURE 1173 are particularly suitable.
[0038] In certain embodiments, the radiation curable compositions
of the present invention comprise 0.01 up to 15 percent by weight
of free radical photoinitiator or, in some embodiments, 0.01 up to
10 percent by weight, or, in yet other embodiments, 0.01 up to 5
percent by weight of free radical photoinitiator based on the total
weight of the composition.
[0039] In certain embodiments, the compositions of the present
invention also comprise any of a variety of other additives, such
as rheology modifiers, surfactants, UV-light stabilizer, dyes,
pigments, sanding additives, antioxidants, solvents, and flatting
agents (e.g. wax-coated or non-wax coated silica or other inorganic
materials), among other materials.
[0040] In certain embodiments, the coating compositions of the
present invention also include a colorant. As used herein, the term
"colorant" means any substance that imparts color and/or other
opacity and/or other visual effect to the composition. The colorant
can be added to the coating in any suitable form, such as discrete
particles, dispersions, solutions and/or flakes. A single colorant
or a mixture of two or more colorants can be used in the coatings
of the present invention.
[0041] Example colorants include pigments, dyes and tints, such as
those used in the paint industry and/or listed in the Dry Color
Manufacturers Association (DCMA), as well as special effect
compositions. A colorant may include, for example, a finely divided
solid powder that is insoluble but wettable under the conditions of
use. A colorant can be organic or inorganic and can be agglomerated
or non-agglomerated. Colorants can be incorporated into the
coatings by use of a grind vehicle, such as an acrylic grind
vehicle, the use of which will be familiar to one skilled in the
art.
[0042] Example pigments and/or pigment compositions include, but
are not limited to, carbazole dioxazine crude pigment, azo,
monoazo, disazo, naphthol AS, salt type (lakes), benzimidazolone,
condensation, metal complex, isoindolinone, isoindoline and
polycyclic phthalocyanine, quinacridone, perylene, perinone,
diketopyrrolo pyrrole, thioindigo, anthraquinone, indanthrone,
anthrapyrimidine, flavanthrone, pyranthrone, anthanthrone,
dioxazine, triarylcarbonium, quinophthalone pigments, diketo
pyrrolo pyrrole red ("DPPBO red"), titanium dioxide, carbon black
and mixtures thereof. The terms "pigment" and "colored filler" can
be used interchangeably.
[0043] Example dyes include, but are not limited to, those that are
solvent and/or aqueous based such as pthalo green or blue, iron
oxide, bismuth vanadate, anthraquinone, perylene, aluminum and
quinacridone.
[0044] Example tints include, but are not limited to, pigments
dispersed in water-based or water miscible carriers such as
AQUA-CHEM 896 commercially available from Degussa, Inc., CHARISMA
COLORANTS and MAXITONER INDUSTRIAL COLORANTS commercially available
from Accurate Dispersions division of Eastman Chemical, Inc.
[0045] As noted above, the colorant can be in the form of a
dispersion including, but not limited to, a nanoparticle
dispersion. Nanoparticle dispersions can include one or more highly
dispersed nanoparticle colorants and/or colorant particles that
produce a desired visible color and/or opacity and/or visual
effect. Nanoparticle dispersions can include colorants such as
pigments or dyes having a particle size of less than 150 nm, such
as less than 70 nm, or less than 30 nm. Nanoparticles can be
produced by milling stock organic or inorganic pigments with
grinding media having a particle size of less than 0.5 mm Example
nanoparticle dispersions and methods for making them are identified
in U.S. Pat. No. 6,875,800 B2, which is incorporated herein by
reference. Nanoparticle dispersions can also be produced by
crystallization, precipitation, gas phase condensation, and
chemical attrition (i.e., partial dissolution). In order to
minimize re-agglomeration of nanoparticles within the coating, a
dispersion of resin-coated nanoparticles can be used. As used
herein, a "dispersion of resin-coated nanoparticles" refers to a
continuous phase in which is dispersed discreet "composite
microparticles" that comprise a nanoparticle and a resin coating on
the nanoparticle. Example dispersions of resin-coated nanoparticles
and methods for making them are identified in United States Patent
Application Publication 2005-0287348 A1, filed Jun. 24, 2004, U.S.
Provisional Application No. 60/482,167 filed Jun. 24, 2003, and
U.S. patent application Ser. No. 11/337,062, filed Jan. 20, 2006,
which is also incorporated herein by reference.
[0046] Example special effect compositions that may be used in the
compositions of the present invention include pigments and/or
compositions that produce one or more appearance effects such as
reflectance, pearlescence, metallic sheen, phosphorescence,
fluorescence, photochromism, photosensitivity, thermochromism,
goniochromism and/or color-change. Additional special effect
compositions can provide other perceptible properties, such as
opacity or texture. In a non-limiting embodiment, special effect
compositions can produce a color shift, such that the color of the
coating changes when the coating is viewed at different angles.
Example color effect compositions are identified in U.S. Pat. No.
6,894,086, incorporated herein by reference. Additional color
effect compositions can include transparent coated mica and/or
synthetic mica, coated silica, coated alumina, a transparent liquid
crystal pigment, a liquid crystal coating, and/or any composition
wherein interference results from a refractive index differential
within the material and not because of the refractive index
differential between the surface of the material and the air.
[0047] In general, the colorant can be present in any amount
sufficient to impart the desired visual and/or color effect. The
colorant may comprise from 1 to 65 weight percent of the present
compositions, such as from 3 to 40 weight percent or 5 to 35 weight
percent, with weight percent based on the total weight of the
compositions.
[0048] The radiation curable compositions of the present invention
may be applied directly onto the surface of a substrate or over an
underlayer by any suitable coating process known to those of
ordinary skill in the art, for example, by dip coating, direct roll
coating, reverse roll coating, curtain coating, spray coating,
brush coating, vacuum coating and combinations thereof. The method
and apparatus for applying the composition to the substrate may be
determined, at least in part, by the configuration and type of
substrate material. Dry film thickness can range from, for example,
about 0.1 to 3.0 mils (2.5 to 76.2 microns) per layer, such as 0.2
to 2.0 mils (5.1 to 50.8 microns) per layer or, in some
embodiments, 0.2 to 1.0 mil (5.1 to 25.4 microns) per layer.
[0049] Suitable substrates include cellulosic-containing materials,
including paper, paperboard, cardboard, plywood and pressed fiber
boards, hardwood, softwood, wood veneer, particleboard, chipboard,
oriented strand board, and fiberboard. Such materials may be made
entirely of wood, such as pine, oak, maple, mahogany, cherry, and
the like. In some cases, however, the materials may comprise wood
in combination with another material, such as a resinous material,
i.e., wood/resin composites, such as phenolic composites,
composites of wood fibers and thermoplastic polymers, and wood
composites reinforced with cement, fibers, or plastic cladding. In
certain embodiments, such a substrate has been coated or treated
with a wood stain and or toner prior to application of the
compositions of the present invention.
[0050] Suitable metallic substrates include, but are not limited
to, foils, sheets, or workpieces constructed of cold rolled steel,
stainless steel and steel surface-treated with any of zinc metal,
zinc compounds and zinc alloys (including electrogalvanized steel,
hot-dipped galvanized steel, GALVANNEAL steel, and steel plated
with zinc alloy), copper, magnesium, and alloys thereof, aluminum
alloys, zinc-aluminum alloys such as GALFAN, GALVALUME, aluminum
plated steel and aluminum alloy plated steel substrates may also be
used. Steel substrates (such as cold rolled steel or any of the
steel substrates listed above) coated with a weldable, zinc-rich or
iron phosphide-rich organic coating are also suitable for use in
the process of the present invention. Such weldable coating
compositions are disclosed in U.S. Pat. Nos. 4,157,924 and
4,186,036. Cold rolled steel is also suitable when pretreated with,
for example, a solution selected from the group consisting of a
metal phosphate solution, an aqueous solution containing at least
one Group IIIB or IVB metal, an organophosphate solution, an
organophosphonate solution, and combinations thereof. Also,
suitable metallic substrates include silver, gold, and alloys
thereof.
[0051] Examples of suitable silicatic substrates are glass,
porcelain and ceramics.
[0052] Examples of suitable polymeric substrates are polystyrene,
polyamides, polyesters, polyethylene, polypropylene, melamine
resins, polyacrylates, polyacrylonitrile, polyurethanes,
polycarbonates, polyvinyl chloride, polyvinyl alcohols, polyvinyl
acetates, polyvinylpyrrolidones and corresponding copolymers and
block copolymers, biodegradable polymers and natural polymers--such
as gelatin.
[0053] Examples of suitable textile substrates are fibers, yarns,
threads, knits, wovens, nonwovens and garments composed of
polyester, modified polyester, polyester blend fabrics, nylon,
cotton, cotton blend fabrics, jute, flax, hemp and ramie, viscose,
wool, silk, polyamide, polyamide blend fabrics, polyacrylonitrile,
triacetate, acetate, polycarbonate, polypropylene, polyvinyl
chloride, polyester microfibers and glass fiber fabric.
[0054] Examples of suitable leather substrates are grain leather
(e.g. nappa from sheep, goat or cow and box-leather from calf or
cow), suede leather (e.g. velours from sheep, goat or calf and
hunting leather), split velours (e.g. from cow or calf skin),
buckskin and nubuk leather; further also woolen skins and furs
(e.g. fur-bearing suede leather). The leather may have been tanned
by any conventional tanning method, in particular vegetable,
mineral, synthetic or combined tanned (e.g. chrome tanned, zirconyl
tanned, aluminium tanned or semi-chrome tanned). If desired, the
leather may also be re-tanned; for re-tanning there may be used any
tanning agent conventionally employed for re-tanning, e.g. mineral,
vegetable or synthetic tanning agents, e.g., chromium, zirconyl or
aluminium derivatives, quebracho, chestnut or mimosa extracts,
aromatic syntans, polyurethanes, (co) polymers of (meth)acrylic
acid compounds or melamine/, dicyanodiamide/and/or
urea/formaldehyde resins.
[0055] Examples of suitable compressible substrates include foam
substrates, polymeric bladders filled with liquid, polymeric
bladders filled with air and/or gas, and/or polymeric bladders
filled with plasma. As used herein the term "foam substrate" means
a polymeric or natural material that comprises a open cell foam
and/or closed cell foam. As used herein, the term "open cell foam"
means that the foam comprises a plurality of interconnected air
chambers. As used herein, the term "closed cell foam" means that
the foam comprises a series of discrete closed pores. Example foam
substrates include polystyrene foams, polymethacrylimide foams,
polyvinylchloride foams, polyurethane foams, polypropylene foams,
polyethylene foams, and polyolefinic foams. Example polyolefinic
foams include polypropylene foams, polyethylene foams and/or
ethylene vinyl acetate (EVA) foam. EVA foam can include flat sheets
or slabs or molded EVA forms, such as shoe midsoles. Different
types of EVA foam can have different types of surface porosity.
Molded EVA can comprise a dense surface or "skin", whereas flat
sheets or slabs can exhibit a porous surface.
[0056] Once applied, the compositions of the present invention can
be cured by radiation. Thus, for example, the compositions of the
present invention may be cured by, for example, irradiation with
ultraviolet rays, electron beam radiation, as is known to those
skilled in the art and described in the Examples. In certain
embodiments, curing can be completed in less than one minute.
[0057] Illustrating the invention are the following examples that
are not to be considered as limiting the invention to their
details. All parts and percentages in the examples, as well as
throughout the specification, are by weight unless otherwise
indicated.
Example 1
[0058] The coatings shown in Table I were prepared by adding weight
in grams of each material under agitation and stirring until
uniform. pH was measured using an Accumet Research model AR15 pH
meter. Viscosity was measured at 77.degree. F. (25.degree. C.) and
12 rpm using a Brookfield DV-II digital viscometer with a #52
spindle. Viscosities were measured initially and after samples were
aged for 28 days at 120.degree. F.
TABLE-US-00001 TABLE I Sample 1 Sample 2 Sample 3 Ingredient
NeoCryl A-633.sup.1 111.1 111.1 NeoCryl XK-220.sup.2 99.23
Deionized water 15.53 Igepal CO 430.sup.3 0.23 0.23 0.22 Rhodapex
CO 436.sup.4 0.38 0.38 0.37 Ditrimethylol propane tetraacrylate
22.86 22.86 Trimethylol propane triacrylate 21.88 Lux 440.sup.5
50.72 50.72 48.28 Deionized water 21.41 21.41 19.99 2-butoxy
ethanol 5.12 5.12 5.00 Deionized water 10.08 10.08
n-methyl-2-pyrrolidone 3.00 3.00 3.00 Dipropylene glycol 2.00 2.00
monomethyl ether DSX-1514.sup.6 1.16 1.16 2.00 Airex 902.sup.7 0.78
0.78 0.74 OK 520.sup.8 1.09 1.09 1.18 Tego Glide 440.sup.9 0.66
0.66 0.64 Foamex 822.sup.10 1.30 1.30 1.25 Irgacur 500.sup.11 2.58
2.58 2.50 Byk 348.sup.12 1.30 1.30 1.25 Deionized water 14.22 14.22
n-ethyl morpholine 2.2 4.30 Dimethyl ethanol amine 1.00 Deionized
water 19.99 Testing Initial pH 8.21 8.26 8.64 Initial viscosity cps
165 184 151 14 day heat aged viscosity cps 217 466 143 28 day heat
aged viscosity cps 384 Off scale 197 .sup.1Acrylic emulsion from
Neo Resins. .sup.2Acrylic emulsion from Neo Resins. .sup.3Nonionic
wetting agent from Rhodia. .sup.4Anionic surfactant from Rhodia.
.sup.5UV Crosslinkable dispersion from Alberdingk-Boley.
.sup.6Aqueous urethane emulsion from Cognis. .sup.7Polyether
siloxane emulsion from Tego Chemie. .sup.8Amorphous precipitated
silica from Degussa. .sup.9Polyether modified siloxane from Degussa
Goldschmidt. .sup.10Polyether polysiloxane from Degussa
Goldschmidt. .sup.11Photoinitiator mixture from Ciba Additives.
.sup.12Polyether modified siloxane from Byk-Chemie.
Test Substrates
[0059] After 4 weeks aging at 120.degree. F., Sample 3 was drawn
down on a Leneta chart using a 046 wire wound bar, flashed 15
minutes at 120.degree. F. and UV cured using 80 W/cm medium
pressure mercury UV curing lamps (part no. 25-20008-E), available
from Western Quartz Products, Inc. with 1000 mJ/cm.sup.2 UVA as
measured using a Power Puck radiometer. Stain marking of resultant
cured film immediately after chemical spot testing is shown in
Table II.
TABLE-US-00002 TABLE II Chemical Stain 1 hour spot with mustard
Slight mark 24 hour spot with (50 weight % isopropanol in water)
Slight mark 24 hour spot with concentrated lemon juice No mark
[0060] It will be appreciated by those skilled in the art that
changes could be made to the embodiments described above without
departing from the broad inventive concept thereof. It is
understood, therefore, that this invention is not limited to the
particular embodiments disclosed, but it is intended to cover
modifications which are within the spirit and scope of the
invention, as defined by the appended claims.
* * * * *