Polymer compositions containing hydroxyl functional (meth)acrylates and hydroxyalkyl carbamate (meth)acrylates and mixtures thereof

This invention relates to novel copolymers based on the copolymerization product of hydroxyl (meth)acrylate esters and (meth)acrylate esters of hydroxyalkyl carbamates; and other homopolymers and copolymers base on (meth)acrylate esters. In addition, novel copolymer blends may be formulated from individual copolymers based on hydroxyl (meth)acrylate esters and individual (meth)acrylate esters of hydroxyalkyl carbamates. Mixtures including crosslinking agents may be used to provide curable copolymer or copolymer-blend coating compositions.

BACKGROUND OF THE INVENTION 
The present invention relates to novel copolymers based on (meth)acrylate 
esters of hydroxyls and (meth)acrylate esters of hydroxyalkyl carbamates, 
which have been copolymerized with each other, to provide polymers having 
improved properties. 
(Meth)acrylic polymers are known in commerce, and are formed by 
polymerization of one or more (meth)acrylates. These acrylic polymers can 
be formed into coatings, inks, and the like that have either a 
thermoplastic or soluble character or a thermoset or insoluble character. 
Such products are known to have good hydrolytic stability and other 
weathering characteristics particularly in comparison to polyesters and 
polyethers. Even though acrylic polymers have such desirable properties, 
the coatings industry actively seeks coatings having improved hydrolytic 
resistance particularly at high and low pH values over those of the 
current acrylics. Such improved resistance would result in products that 
have enhanced resistance to hostile environments such as those caused by 
acid rain, by air-borne chemicals, by cleaners used for dirt removal, by 
erosion due to dirt particles or other debris, by actinic energy such as 
from sunlight, and the like. 
It is well known that polymers containing free hydroxyl functionality can 
be crosslinked with various aminoplasts such as hexamethoxymelamine and 
such aminoplast crosslinking agents are widely used in combination with 
various polymers including the acrylic polymers described above to provide 
coatings for a variety of substrates. However, it is believed that coating 
compositions based on these type polymers and crosslinking agents are less 
likely to withstand harsh environmental conditions due to the weak ether 
linkage formed between a reactive group on the crosslinking agent and the 
hydroxyl group of the polymer to be crosslinked. 
The demanding nature of today's marketplace, which is driven by quality, 
energy, and environmental considerations, has developed a need for 
coatings with improved resistance to chemical attack from water, acids, 
alkalis, and the like. 
SUMMARY OF THE INVENTION 
Applicants have discovered novel copolymers and copolymer blends based on 
the copolymerization product of one or more (meth)acrylate esters of 
hydroxyl functional monomers, and one or more (meth)acrylate esters of 
hydroxyalkyl carbamates. The novel copolymers may also be formed by 
copolymerizing the individual components and mixing to form copolymer 
blends. The copolymers or copolymer blends also include other 
(meth)acrylate homopolymers and copolymers and optionally, may include 
ethylenically unsaturated monomers. 
The term "(meth)acrylate," as used herein, refers to both acrylate and 
methacrylate polymers and both oligomers of relatively low molecular 
weight copolymers, copolymers of relatively high molecular weight, and 
high molecular weight polymers thereof. The term "copolymer" is 
contemplated to include oligomers and polymers. 
In addition, the invention relates to compositions containing the above 
copolymer or copolymer blends and one or more crosslinking agents reactive 
with at least one of the carbamate or hydroxyl functionalities present, 
preferably with both types of functionalities. Suitable catalysts, 
photoinitiators if cured with ultraviolet light, and the like, as well as 
optionally wetting agents, fillers, pigments, colorants, fungicides, 
stabilizers, and the like as are known to those skilled in the art of 
coating formulation may be included. 
Coating, ink, adhesive, and sealant compositions formed from the copolymers 
or copolymer blends of the present invention can be cured by simple 
solvent evaporation; by thermal means from solution; by photochemical 
means; or, if the copolymer has a sufficiently high glass transition 
temperature, from a powder form. 
DETAILED DESCRIPTION OF THE INVENTION 
This invention relates to copolymers and copolymer blends comprising novel 
(meth)acrylate polymers and, optionally, crosslinking agents, and other 
ingredients known to those skilled in the art of formulation. 
The preferred (meth)acrylate copolymers are based on the copolymerization 
product of (a) one or more hydroxyl functional (meth)acrylate monomers and 
(b) one or more (meth)acrylate esters of hydroxyalkyl carbamates, along 
with other (meth)acrylate comonomers. 
The preferred hindered-hydroxyl functional (meth)acrylate monomers, 
component (a), can be prepared, for example, by (i) direct esterification 
of appropriate diol compound with methacrylic acid or acrylic acid, (ii) 
reaction of appropriate diol compound with methacrylic anhydride or 
acrylic anhydride, and (iii) transesterification of appropriate diol 
compound with alkyl methacrylate or alkyl acrylate, e.g., methyl 
methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl 
methacrylate, propyl acrylate, and the like. Such preparation procedures 
are described in copending U.S. patent application Ser. No. 07/962,559, 
incorporated herein by reference. 
Illustrative hindered-hydroxyl functional (meth)acrylate monomers useful in 
this invention include, for example, 2-ethyl-3-hydroxyhexyl methacrylate, 
1-propyl-2-ethyl-3 hydroxypropyl methacrylate, 
1-ethyl-2-methyl-3-hydroxypropyl methacrylate, 2-methyl-3-hydroxypentyl 
methacrylate, 2,2,4-trimethyl-3-hydroxypentyl methacrylate, 
2-propyl-3-hydroxyheptyl methacrylate, 1-butyl-2-propyl-3-hydroxypropyl 
methacrylate, 2-ethyl-3-hydroxyheptyl methacrylate, 
1-butyl-2-ethyl-3-hydroxypropyl methacrylate, 2-propyl-3-hydroxypropyl 
methacrylate, 2-ethyl-3-hydroxypropyl methacrylate, 
1-i-butyl-2-i-propyl-3-hydroxypropyl methacrylate, 
2-i-propyl-3-hydroxy-5-methylhexyl methacrylate, 
1-methyl-2-i-propyl-3-hydroxypropyl methacrylate, 
2-i-propyl-3-methyl-3-hydroxypropyl acrylate, 1-i-butyl-3-hydroxypropyl 
methacrylate, 3-hydroxy-5-methylhexyl methacrylate, 
1-methyl-2-butyl-3-hydroxypropyl methacrylate, 2-butyl-3-hydroxybutyl 
methacrylate, 1-i-propyl-2,2-dimethyl-3-hydroxypropyl methacrylate, 
2,2-dimethyl-3-hydroxy-4-methylpentyl methacrylate, and the like. 
Preferred hindered-hydroxyl functional (meth)acrylate monomers useful in 
this invention are obtained from 2,2,4-trimethyl-1,3-pentanediol, 
2-methyl-1,3-pentanediol and 2-ethyl-1,3 hexanediol. 
Other hydroxyl functional (meth)acrylate monomers, component (a), useful in 
the present invention may be prepared by methods described in U.S. Pat. 
No. 3,674,838 such as 1) by the reaction of .alpha.,.beta.-unsaturated 
acids such as acrylic acid, methacrylic acid, .alpha.-ethylacrylic acid, 
.alpha.-phenyl acrylic acid, .alpha.-benzyl acrylic acid, .alpha.-chloro 
acrylic acids, and the like ,with epoxy compounds including 1,2-epoxy 
aliphatics such as epoxy ethane, ethylene oxide, 1,2-epoxy propane, 
1,2-epoxy butance, etc., and other epoxy compounds such as trimethylene 
oxide, 1,3-epoxy butane, 2,3-epoxy butane, .alpha.,.alpha.'-epoxy 
dibenzyl, and tetrahydrofuran; and 2) by the reaction of the above 
.alpha.,.beta.-unsaturated acids with dihydric alcohols having both 
hydroxyl groups connected to carbon atoms having hydrogen as theonly other 
substituent. Preferred hydroxyl funtional (meth)acrylate monomers include 
hydroxy ethyl (meth)acrylate, hydroxy propyl (meth)acrylate and hydroxy 
butyl (meth)acrylate, hydroxy butyl (meth)acrylates, hydroxy decyl 
(meth)acrylates, and the like; including caprolactone (meth)acrylates 
which are the product of reacting an e-carpolactone with a hydroxyalkyl 
acrylate and which have both acrylate and hydroxyl functionality. 
The preferred (meth)acrylate esters of hydroxyalkyl carbamates useful in 
the practice of this invention include compounds having the formula: 
##STR1## 
wherein R is hydrogen or methyl; R' is hydrogen; R" is hydrogen or lower 
alkyl of 1 to 8 carbon atoms; and X is a linear, branched, or cyclic, 
substituted or unsubstituted hydrocarbyl of 1 to 20 carbon atoms, 
preferably from 2 to 12 carbon atoms, and most preferably from 2 to 8 
carbon atoms. 
As used herein, the term "O-carbamate" refers to the compounds of the above 
Formula I wherein R" is hydrogen; while the term "N-carbamate" refers to 
compounds of the above Formula I wherein R" is a lower alkyl of 1 to 8 
carbon atoms. 
(Meth) acrylate esters of hydroxyalkyl carbamates useful in the practice of 
the present invention may be conveniently prepared by methods known in the 
art. U.S. Pat. No. 3,674,838 describes methods of preparing O-carbamates 
(meth)acrylates including by the reaction of a hydroxy functional ester 
with phosgene to form a chloroformate intermediate; which is then reacted 
with ammonia to give the desired O-carbamate. Illustrative of useful 
O-carbamate (meth)acrylates include 2-hydroxy ethyl carbamate 
(meth)acrylate, 2-hydroxy propyl carbamate (meth)acrylate, and 2-hydroxy 
butyl carbamate (meth)acrylate. 
U.S. Pat. No. 4,126,747 discloses useful N-carbamate (meth)acrylates for 
the practice of the present invention. Such N-carbamate (meth)acrylates 
may be prepared by the acid-catalyzed direct esterification of acrylic or 
methacrylic acid with the desired hydroxyalkyl carbamate such as hydroxy 
ethyl methacrylate, hydroxy propyl (meth)acrylate, hydroxy butyl 
methacrylate, and the like. Those skilled in the art are fully familiar 
with this class of compounds and will appreciate that mixtures can also be 
used. Illustrative of useful N-carbamate (meth)acrylates include 
N-methyl-2-hydroxyethyl carbamate (meth)acrylate, N-ethyl-2-hydroxyethyl 
carbamate (meth)acrylate, N-propyl-2-hydroxyethyl carbamate 
(meth)acrylate, N-butyl-2-hydroxyethyl carbamate (meth)acrylate, 
N-methyl-2-hydroxypropyl carbamate (meth)acrylate, N-ethyl-2-hydroxypropyl 
carbamate (meth)acrylate, N-propyl-2-hydroxypropyl carbamate 
(meth)acrylate, and N-butyl-2-hydroxypropyl carbamate (meth)acrylate. 
X may be any suitable linear, branched, or cyclic, substituted or 
unsubstituted hydrocarbyl of 1 to 20 carbon atoms, preferably from 2 to 12 
carbon atoms, and most preferably from 2 to 8 carbon atoms; including 
alkyl radicals such as, among others, ethyl, n-propyl, isopropyl, n-butyl, 
isobutyl, chloropropyl, and nitrobutyl; aryl radicals including benzyl and 
phenylether; divalent alkyl radicals such as methylene, ethylene, 
propylene, isopropylene, butylene, isobutylene, dodecamethylene; as well 
as divalent aryl radicals such as ortho-, meta- and paraphenylene, and 
-napthalene, and divalent aralkyl radicals such as methylphenylene, 
ethylphenylene, phenylmethylene and phenylethylene. 
The copolymers containing hydroxyl functional (meth)acrylate monomers and 
hydroxyalkyl carbamate (meth)acrylate may be polymerized in amounts of 
each component from about 0.1 to 80 weight percent of the total copolymer 
composition; more preferably from about 1 to 50 weight percent of the 
total copolymer composition; and most preferably from about 5 to about 50 
weight percent of the total copolymer composition. 
Suitable comonomers copolymerizable with components (a) and (b) above 
include acrylic acid, methacrylic acid, the esters of acrylic and 
methacrylic acid such as the various methyl, ethyl, propyl, butyl, pentyl, 
hexyl, octyl, decyl, and dodecyl acrylates and the like, including the 
various isomers of these and other listed compounds; bornyl, isobornyl, 
norbornyl and isonorbornyl acrylate; 
3-(meth)acryloxypropyltris(tri-methylsiloxy) silane; ethoxylated and 
propoxylated acrylates which are the product of reacting an alkylene oxide 
illustrative of which are ethylene oxide, propylene oxide, and the like, 
with an hydroxyalkyl acrylate; cyclohexyl acrylate, 2-phenoxyethyl 
acrylate, glycidyl acrylate, and the like. Small amounts of up to 5% by 
weight of di(meth)acrylates or higher functionality (meth)acrylates, such 
as those found during manufacture of many (meth)acrylates, may be used in 
the polymerization, though it is preferred that such multifunctional 
(meth)acrylates be removed using methods know in the art, such as 
distillation. 
Illustrative of ethylenically unsaturated monomers which may optionally be 
copolymerized with the novel (meth)acrylate esters of the present 
invention include styrene, vinyl cyclohexane, vinyl cyclohexene, vinyl 
cyclooctane, N-vinyl-pyrrolidone, vinyl pyridines, vinyl imidazole, vinyl 
naphthalene, acrylonitrile, methacrylonitrile, vinyl chloride, vinyl 
fluoride, vinyl bromide, vinylidine fluoride, vinylidine chloride, 
5-vinyl-2-norbornene and other vinyl norbornenes; vinyl esters such as 
vinyl acetate, vinyl trifluoroacetate, vinyl propionates, vinyl butyrates, 
vinyl pentanoates, vinyl 2-ethylhexanoate, vinyl nonanoates, vinyl 
decanoates, vinyl neonanoate, vinyl neodecanoate, vinyl neopentanoate and 
the like; vinyl ethers such as vinyl alcohol which is formed by the 
hydrolysis of vinyl acetate, vinyl propionates, vinyl triethylene glycol 
and the like; vinyl acetic acid, 3-vinylbenzyl chloride, 4-vinylbiphenyl, 
vinyl carbazole, vinyl chloroformate, vinyl crotonate, 
vinyltrimethylsilane, vinyltrimethoxysilane, vinylferrocene, 
vinyltributyltin, vinyl sulfonic acid, and the like. Included within the 
definition of vinyl compounds is maleic anhydride, maleic acid, and 
maleate esters and half esters. 
These other comonomers based on (meth)acrylate homopolymers or copolymers, 
and optional ethylenically unsaturated monomers may be copolymerized with 
the functional components (a) and (b) in amounts of from about 0 to 90 
weight percent of the total copolymer composition; more preferably from 10 
to 80 weight percent of the total copolymer composition; and most 
preferably from about 20 to 70 weight percent of the total copolymer 
composition. 
The novel (meth)acrylate copolymers of this invention can be prepared by a 
variety of polymerization techniques illustrative of which are solution 
polymerization, aqueous emulsion, dispersion, or suspension 
polymerization, bulk polymerization, nonaqueous emulstion, dispersion, or 
suspension polymerization, and the like. Said polymerizations can be 
effected in a variety of reactors illustrative of which are stirred batch 
reaction, tubular reactors, and the like and can be made of various 
materials of construction all of which are known to those skilled in the 
art of conducting such polymerizations. 
In a preferred embodiment, the novel (meth)acrylate copolymers of the 
present invention include the copolymerization product of isomers 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxypropyl methacrylate as component (a) and 
2-hydroxyl propyl carbamate methacrylate as component (b); with other 
(meth)acrylate comonomers such as 2-ethylhexyl acrylate and cyclohexyl 
methacrylate. 
In another embodiment of the present invention, novel (meth)acrylate 
copolymers are based on the copolymerization product of one or more 
(meth)acrylate esters of hydroxyalkyl carbamates having the following 
Formula I: 
##STR2## 
wherein R, X, R' and R" have the same meaning above, provided at least one 
of the (meth)acrylate esters of hydroxyalkyl carbamates has R" as a lower 
alkyl of 1 to 8 carbon atoms. 
Illustrative of preferred copolymerizations of an O-carbamate 
(meth)acrylate and an N-carbamate (meth)acrylate includes the 
copolymerization of an O-carbamate selected from the group including 
2-hydroxy ethyl carbamate (meth)acrylate, 2-hydroxy propyl carbamate 
(meth)acrylate, and 2-hydroxy butyl carbamate (meth)acrylate; and an 
N-carbamate (meth)acrylate selected from the group including 
N-methyl-2-hydroxyethyl carbamate (meth)acrylate, N-ethyl-2-hydroxyethyl 
carbamate (meth)acrylate, N-propyl-2-hydroxyethyl carbamate 
(meth)acrylate, Nobutyl-2-hydroxyethyl carbamate (meth)acrylate, 
N-methyl-2-hydroxypropyl carbamate (meth)acrylate, N-ethyl-2-hydroxypropyl 
carbamate (meth)acrylate, N-propyl-2-hydroxypropyl carbamate 
(meth)acrylate, and N-butyl-2-hydroxypropyl carbamate (meth)acrylate; 
along with the above described suitable comonomers. 
The copolymers containing hydroxyalkyl carbamate (meth)acrylate of the 
above formula may be polymerized in amounts of each component, O-carbamate 
and N-carbamate, from about 0.1 to 80 weight percent of the total 
copolymer composition; more preferably from about 1 to 50 weight percent 
of the total copolymer composition; and most preferably from about 5 to 
about 50 weight percent of the total copolymer composition. Again, the 
remaining percentage is made up of comonomers of other (meth)acrylate 
homopolymers and polymers or the optional ethylenically unsaturated 
monomers. 
In addition, novel copolymers of (meth)acrylates may be formed from the 
copolymerization product of N-carbamate (meth)acrylates and the above 
described comonomers; illustrative of which is the copolymerization 
product of N-methyl-2-hydroxyethyl carbamate (meth)acrylate, 
Noethyl-2-hydroxyethyl carbamate (meth)acrylate, N-propyl-2-hydroxyethyl 
carbamate (meth)acrylate, N-butyl-2-hydroxyethyl carbamate (meth)acrylate, 
N-methyl-2-hydroxypropyl carbamate (meth)acrylate, N-ethyl-2-hydroxypropyl 
carbamate (meth)acrylate, N-propyl-2-hydroxypropyl carbamate 
(meth)acrylate, or N-butyl-2-hydroxypropyl carbamate (meth)acrylate, with 
the above described suitable comonomers such as 2-ethylhexyl acrylate and 
cyclohexyl methacrylate. 
Copolymer blends may be formulated by copolymerizing the individual 
monomers of components (a) with the desired comonomers, and component (b) 
with the desired comonomers, to make individual copolymers of (a) and (b); 
and then physically mixing the two copolymers to make a blend of 
copolymers. 
In another embodiment, novel copolymer blends may be formulated using 
individual copolymers of an O-carbamate (meth)acrylate and an N-carbamate 
(meth)acrylate, to yield the desired blend. 
Coating compositions containing the above-described copolymers and 
copolymer blends may be formulated to contain one or more crosslinking 
agents, preferably one or more of a catalyst or photoinitiator, and 
optionally one or more of an inert solvent, a surfactant or other flow and 
leveling agent, a slip agent, pigments and/or other colorants, fillers, 
and other ingredients known to those skilled in the art of formulation. 
Illustrative of crosslinking agents suitable for crosslinking the copolymer 
or copolymer blend compositions of the invention are aminoplasts including 
guanidines and polyguanidines, multifunctional isocyanates which term 
includes blocked isocyanates, phenolics, cycloaliphatic epoxides, glycidyl 
epoxides; carbodiimides and polycarbodiimides, and the like. Mixtures of 
the various crosslinking agents can be used as long as there is no 
interference with the crosslinking function. 
Preferred aminoplast crosslinking agents include alkoxymelamines, 
melamine-formaldehydes, urea-formaldehydes, alkylated benzoguanimines, 
guanyl ureas, guanidines, biguanidines, polyguanidines, and the like. More 
preferred compounds include methylated melamine, 
hexamethoxymethyl-melamine, butylated melamine, methylated/butylated 
melamine, butylated urea, benzoguanidine, and the like. 
Multifunctional isocyanate crosslinking agents may also be used. 
Illustrative of which are 4,4'-diphenylmethane diisocyanate, 
4,4'-dicyclohexyl diisocyanate, 2,4- and 2,6-toluene diisocyanate, 
isophorone diisocyanate, xylidiene diisocyanate, meta- and 
para-tetramethylxylene diisocyanate, hexamethylene diisocyanate, 2,2,4- 
and 2,4,4-trimethylhexamethylene diisocyanate, 4,4',4"-triisocyanato 
triphenylmethane, biurets of hexamethylene diisocyanate with an average 
functionality greater than 2, and the like. Multifunctional isocyanates 
that have been blocked with phenols, caprolactam, methyl ethyl ketone 
oxime, and the like, are particularly useful for storage stable systems 
that are thermally cured. 
Phenolic crosslinking agents useful in the practice of this invention are 
the soluble, heat-reactive phenols or cresols such as those described in 
T. S. Carswell, Phenoplasts, pages 9-29, Interscience Publishers Inc., New 
York (1947) and in J. A. Brydson, Plastic Materials, pages 385-386, D. Van 
Nostrand Co. Inc., New Jersey (1966). Illustrative of soluble, 
heat-reactive phenolic crosslinking agents are monomers and polymers of 
alkylated phenol-formaldehyde, alkylated cresol-formaldehyde, including 
methylated phenol-formaldehyde, butylated phenol-formaldehyde, 
cresol-formaldehyde, and the like, as well as various heat reactive 
phenolics made by reacting phenol, propyl phenols, butyl phenols, amyl 
phenols, and/or higher hydrocarbon phenols, o-, m-, and p-cresol, 
xylenols, and the like, with formaldehyde in the presence of a suitable 
catalyst such as ammonia, ethylamine, triethylamine, as well as other 
phenols which are known in the art of making heat reactive phenolics. 
Illustrative of cycloaliphatic epoxide crosslinking agents are 
3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 
3,4-epoxy-6-methyl-cyclohexylmethyl 
3,4-epoxy-6-methylcyclohexane-carboxylate, vinyl cyclohexane diepoxide, 
cyclohexane diepoxide, cyclopentadiene diepoxide, limonene diepoxide, 
.alpha.-pinene diepoxide, 
3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxycyclohexane-m-dioxane, 
bis(3,4-epoxycyclohexylmethyl)adipate, and the like. Polyfunctional 
cycloaliphatic epoxides preferred for use in the present invention include 
those disclosed in U.S. Pat. No. 5,268,489. Small amounts of up to about 
25% of monoepoxides can also be used in the formulation. Specific useful 
monoepoxides are limonene monoepoxide, .alpha.-pinene monoepoxide, vinyl 
3,4-epoxycyclohexane, norbornene monoepoxide, cyclohexane monoepoxide, 
3,4-epoxy derivatives of alkoxylated and/or lactone derivatives of 
tetrahydrobenzyl alcohol, and the like. 
Illustrative of glycidyl epoxide crosslinking agents are the diglycidyl 
ether of bisphenol A, higher homologs of the diglycidyl ether of bisphenol 
A, diglycidyl ethers of brominated bisphenol A, 1,4-butanediol diepoxide, 
epoxy esters, epoxy silanes, epoxy siloxanes, epoxy novolacs, and the 
like. 
Suitable crosslinking agents may be present in the composition in amounts 
from about 5 to about 55 weight percent based on the total copolymer 
composition, more preferably from about 15 to 35, and most preferably from 
about 20 to 30 weight percent. 
It is preferable that a catalyst be used for curing or crosslinking of 
acrylic coating compositions. Illustrative catalysts for thermal curing of 
the coating compositions when aminoplasts and cycloaliphatic epoxides are 
used include, among others, p-toluene sulfonic acid and its salts such as 
ammonium p-toluene sulfonate, diethylammonium sulfonate, 
diisopropyl-ammonium p-toluene sulfonate, and the like; dodecylbenzene 
sulfonic acid and its salts such as ammonium dodecylbenzene sulfonate, 
diethylammonium dodecylbenzene sulfonate, and the like; phosphoric acid 
and its salts; dinonyl-naphthalene sulfonic acids and their salts such as 
ammonium dinonylnaphthalene sulfonic acids, dipropylammonium 
dinonyl-naphthalene sulfonic acids; diethyl-ammonium dinonylnaphthalene 
sulfonic acids, and the like; boron trifiuoride etherate; trimelletic 
acid; trifiic acid and its salts such as diethylammonium trifiate, 
ammonium trifiate, diisopropylammonium trifiate, and the like; and when 
isocyanates are used include, among others, zinc octanoate, stannous 
octanoate, dibutyltin dilaurate, amines, and the like. The triflic acid 
salts are particularly useful when cycloaliphatic epoxides are used as the 
crosslinking agents since they allow low temperature curing conditions to 
be used. 
Catalysts may be present in amounts from about 0.1 to 20 weight percent of 
the total copolymer composition, more preferably from about 0.5 to 10 
weight percent, and most preferably from about 1 to 5 weight percent of 
the total composition. 
The formulations of the present invention may also contain a variety of 
additives including antioxidants, ultraviolet light stabilizers, 
surfactants or other flow and leveling agents illustrative of which are 
silicone oils, acrylic polymers such as MODAFLOWS.TM. available from 
Monsanto Co., silicone/alkylene oxides, fluorocarbon surfactants, and the 
like. In addition, fillers, pigments, thickeners, inert solvents such as 
toluene, pentyl propionate, 1,1,1-trichloroethane, ethoxyethyl acetate, 
propoxyethyl acetate, ethoxybutyl acetate, butyl acetate, methyl isobutyl 
ketone, methyl ethyl ketone, methyl amyl ketone, xylene, and the like may 
be used; along with inert polymers, waxes, adhesion promoters, and slip 
agents such as silicone oils, powdered polytetrafluoroethylene alone or in 
combination with powdered polyethylene and the like. The above optional 
additives are known to those skilled in the art and many are commercially 
available. 
In a particular embodiment of this invention, photocurable coating 
compositions are comprised of (meth)acrylate copolymer and/or copolymer 
blend compositions, cycloaliphatic epoxides, onium salt photoinitiators, 
and certain optional ingredients. These compositions may be cured with 
ultraviolet light, preferably ultraviolet light less than about 350 nm. 
The optional ingredients may include commercially available materials 
illustrative of which are the polyester, poly(alkylene oxide), 
polycaprolactone, and polycarbonate polyols; the glycidyl epoxides; mono- 
and multifunctional acrylates; surfactant and other flow and leveling 
agents, fillers, microspheres, solvents, including reactive solvents, and 
other ingredients such as those previously listed and known to those 
skilled in the art of formulating photocurable, cationic-initiated coating 
systems. In addition, N-carbamate (meth)acrylates of Formula I may be used 
in the above cationic-cure photocure systems as well as in photogenerated 
free-radical-cure and electron beam-cure systems. 
Suitable cation-generating, onium-salt photoinitiators for the photocurable 
compositions of the invention include one or more aromatic iodonium 
complex salt or aromatic sulfonium complex salt. Illustrative of such 
photoinitiators are the complex salts described in U.S. Pat. Nos. 
4,231,951, in 4,161,478, in 4,069,055, in 4,058,400, in 4,256,828; the 
bis(4-(diphenylsulfonio)phenyl)- sulfide-bis-hexafluorometallic salts such 
as the phosphate, arsenate, and antimonate salts described by W. R. Watt 
and coworkers in Journal of Polymer Science: Polymer Chemistry Edition, 
Vol. 22, page 1789, 1984; and the like. Commercially available 
photoinitiators of this class include FX-512 (3M Co.), CYRACURE UVI-6990 
and UVI-6974 (Union Carbide Corp.), KI-85 (Degussa A. G., Germany), and 
SP-150 and SP-170 (Asahi Denka, Japan). When photolyzed, these 
photoinitiators fragment into both cationic species and free radicals. The 
formulations can optionally contain benzophenone. 
Illustrative of photoinitiators useful in noncationic, free-radical 
initiated radiation-cure systems are 2,2-diethoxy-acetophenone, benzoin 
ethers, benzophenone, benzophenone in combination with an amine, urea, 
urethane or other synergist, and the like. 
Such photoinitiators may be present in the copolymer composition in amounts 
from about 0.05 to 10 weight percent, more preferably from 0.1 to 6 weight 
percent, and most preferably from about 0.2 to 4 weight percent. 
Coating compositions of the present invention may be applied to a variety 
of substrates using any effective, known, means such as spraying, 
brushing, dipping, roll coating, or other appropriate application methods. 
Substrates that can be coated include metals such as iron, steel, 
stainless steel, primed steel, brass, copper, zinc, silver, gold, and the 
like; wood substrates such as siding, indoor and outdoor trim, paneling, 
furniture, baseball bats, hockey sticks, pencils, decorative articles, 
press-board items, and the like; plastics substrates such as molded 
sheet-molding compounds, polycarbonates, polyolefins, and the like; paper; 
glass; and others. Radiation curable systems are particularly useful when 
curing coatings on plastics and paper. 
A preferred embodiment of a coating composition may include, for example, 
(meth)acrylate copolymers based on the copolymerization product of isomers 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxypropyl methacrylate with 2-hydroxypropyl 
carbamate (meth)acrylate and other desired comonomers, along with a 
methylated/butylated melamine crosslinking agent and a silicone-based 
surfactant. 
Certain of the following preparations and examples are provided to further 
illustrate this invention. 
GLOSSARY OF TERMS 
Aminoplast 1 - A hexamethoxymelamine marketed by American Cyanamid as 
CYMEL.TM. 303. 
Aminoplast 2 - A methylated/butylated melamine marketed by Monsanto Co. as 
RESIMENE.TM. 755. 
Blocked Isocyanate 1 - A blocked isocyanate, that is thought to be a methyl 
ethyl ketone oxime blocked trimer of 4,4'cyclohexane-methyl diisocyanate, 
marketed by Miles, Inc. under the designation Desmodur BL-3174A. 
Catalyst 1 - A 40% by weight solution of para-toluene sulfonic acid in 
methanol. 
Catalyst 2 - Dibutyltin dilaurate. 
Catalyst 3 - A 25% by weight solution of dodecylbenzene sulfonic acid in 
methanol. 
Solvent 1 - A 97/3 by weight mixture of butyl propionate and isobutanol. 
Surfactant 1 - A 25% by weight solution in methyl amyl ketone of a 
silicone-based surfactant marketed by OSi Specialties Inc. as SILWET.TM. 
L-7001. 
Surfactant 2 - A 25% by weight solution in methyl amyl ketone of a 
silicone-based surfactant marketed by OSi Specialties Inc. as SILWET.TM. 
L-77. 
Surfactant 3 - a silicone-based surfactant marketed by OSi Specialties Inc. 
as SILWET.TM. L-7001. 
Surfactant 4 - a silicone-based surfactant marketed by OSi Specialties Inc. 
as SILWET.TM. L-77. 
Photoinitiator 1 - An aryl sulfonium hexafluoroantimonate photoinitiator 
that is marketed by Union Carbide Chemicals and Plastics Co. Inc. as 
CYRACURE.TM. UVI-6974. 
In the examples which follow, the cured compositions were evaluated 
according to one or more of the following procedures: 
Gloss is determined at 20.degree. and 60.degree. by the procedure of ASTM 
D523-85. 
Acid Etch Resistance--A Fini automatic transfer pipette is used to place a 
series of 50 micro-liter droplets of 15% sulfuric acid solution at 
approximately 1/4-inch intervals in two rows along the length of one or 
more coated panels. Usually two panels are required to provide the length 
of surface needed to examine the temperature range of 40.degree. to 
100.degree. C. that is achieved in the gradient temperature oven. Two rows 
of spots are used for duplication of the test. The coated panels are 
placed in an end-to-end position on the heating bank of a BYK Chemie 
gradient temperature oven and aligning the first spots with the #1 rod 
which is at 40.degree. C. which results in the various spots being at 
temperatures that range to 100.degree. C. The sulfuric acid solution 
droplets are allowed to contact the coating for various times at the 
indicated temperatures. After the desired heating time, the panels are 
removed from the gradient oven, cooled to room temperature, rinsed 
thoroughly with distilled water, lightly patted dry, and evaluated. 
Evaluation is by examining the areas that had been covered with the 
droplets with a 10-power, lighted magnifier. The following are points of 
comparison observed and recorded for each coating. 
a) The lowest temperature spot area with a visible defect in the coating. A 
"visible defect" is the first sign of any blush, bubbling, yellowing, or 
other visible change. 
b) The lowest temperature spot with a severe defect. A "severe defect" is 
blistering or complete removal of the coating with the substrate visible. 
This latter factor means the acidic solution has cut through the coating 
to the substrate. 
c) A scaled 1 to 5 rating of any defect or change occurring specifically in 
the 50.degree. C., 60.degree. C., and 70.degree. C. areas of the coating 
using the following rating system. 
1 - FAIL. Coating is cut to the substrate or has severe bubbling. 
2 - SEVERE. Small blister or bubble present in the coating. 
3 - MODERATE. Pinhole defect or slight change in surface of coating by 
fingertip feeling or visible loss of gloss. 
4 - SLIGHT. Blushing or yellowing of coating with no change by fingertip 
feeling. 
5 - UNCHANGED. No visible evidence of any effect. 
Pencil Hardness (ASTM D 3363 74): Pencil leads of increasing harness values 
are forced against the film coating surface in a precisely defined manner 
until one pencil lead cut through the surface of the film coating. The 
surface hardness is considered as the hardest pencil grade which just 
failed to cut through the film coating surface. The pencil leads, in order 
of softest to hardest, are reported as follows: 6B, 5B, 4B, 3B, 2B, B, HB, 
F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, AND 9H. 
Impact Resistance (Forward): A measure of the ability of a cured film 
coating to resist rupture from a falling weight. A Gardner Impact Tester 
using an eight-pound dart is used to test film coatings cast and cured on 
steel panels. The dart is raised to a given height in inches and dropped 
onto the coating side of the coated panel. The inches times pounds, 
designated inches-pounds, absorbed by the film without rupturing is 
recorded as the fil's forward impact resistance. 
Impact Resistance (Reverse): Same description as above, except, the dart is 
dropped onto the uncoated side of the coated panel. 
Viscosity is determined using a Brookfield Viscometer and viscosity 
standards, by the procedure described in ASTM D2196.

EXAMPLES 
Preparation A 
A mixture of the isomers 2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxypropyl methacrylate is prepared by 
placing 900 grams (6.17 moles) of 2,2,4-trimethyl-1,3-pentanediol (TMPD) 
in a four-neck, glass reaction flask equipped with a Therm-O-Watch 
temperature control device, a nitrogen inlet and outlet, a stirrer, and a 
feeding port. The TMPD is melted and dried by heating to 85.degree. C. 
while flowing dry nitrogen through the reaction mass for about 2 hours. 
Then 2.0 grams of methoxyhydroquinone, 2.0 gram of phenothiazine, and 
1,139 grams (7.4 moles) of freshly distilled methacrylic anhydride are 
added. While stirring and employing a nitrogen purge, 40.5 grams of 
distilled pyridine are added and the reaction mass is heated to and held 
at 35.degree. C. for about 36 hours. Excess methacrylic anhydride is then 
quenched by first adding methanol and then washing with water. The mixture 
of monomethacrylate isomers is separated by fractional distillation from 
most or all of any di(meth)acrylate that forms as well as from any other 
impurities. It is expected that about 2% of a di(meth)acrylate will form 
during the synthesis, having the structure: 
EQU CH.sub.2 .dbd.C(CH.sub.3)--CO--O--CH.sub.2 C(CH.sub.3).sub.2 
CH(O--OC--C(CH.sub.3).dbd.CH.sub.2)CH(CH.sub.3)CH.sub.3 
Preparation B 
Preparation of 2-hydroxypropyl carbamate methacrylate. A four-necked, 
five-liter round-bottomed reaction flask equipped with a thermometer, 
condenser, mechanical stirrer, and air sparger is charged with 1,920 g 
(16.1 moles) of 2-hydroxypropyl carbamate, 2,236 g (14.5 moles) of 
distilled methacrylic anhydride, 83 g of anhydrous pyridine, and 4.2 g 
(1,000 parts per million) methoxyhydroquinone. The reaction mass is 
stirred and slowly heated to 65.degree. C. with a hot-water bath. During 
this heating period and during the course of the reaction, the reaction 
mass is sparged with air. The reaction mass is held at 65.degree. C. until 
the concentration of methacrylic anhydride decreased to less than 1.5 
percent by weight. The resulting product is then washed with a saturated 
solution of sodium carbonate, and the aqueous layer removed from the 
solids by decantation. This washing procedure is repeated two more times 
to neutralize all of the methacrylic acid. The resulting solid product is 
then washed twice with a total of two gallons of distilled water. For each 
wash, the solids are melted by heating the wash water to 50.degree. C. 
During the washing procedure, the melted solids are well stirred and the 
aqueous material is allowed to separate from the molten organic material 
and decanted before the desired product resolidifies. The wet product is 
dried overnight in a hood to yield 2,000 g of anhydrous 2-hydroxypropyl 
carbamate methacrylate that analysis indicates has a 97% purity. 
Example 1 
A two-liter round-bottom reaction flask equipped with a mechanical stirrer, 
thermometer, two feed lines designated as A and B, and condenser is 
charged with 100 grams of Solvent 1 while maintaining a nitrogen 
atmosphere in the reaction flask. A nitrogen atmosphere is maintained 
throughout the procedure. The reactor is then heated to reflux 
(.about.140.degree. C.). A mixture of monomers containing 120.0 grams of 
the mixture of 2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxy-propyl methacrylate prepared in 
Preparation A, 109.5 grams of 2-ethylhexyl acrylate, 64.5 grams of 
cyclohexyl methacrylate, and 6.0 grams of methacrylic acid is added 
through Feed Line A and a mixture of 70.0 grams of Solvent 1 and 10.0 
grams of t-amylperoxyacetate catalyst {Lupersol 555M60(60TS)} is added 
through Feed Line B with both additions taking place over a 4-hour time 
period. After the additions are completed, Feed Line A is flushed with 15 
grams of Solvent 1 and the reaction mixture held at 140.degree. C. for an 
additional 30 minutes. Then the reactor is cooled to 100.degree. C., and a 
post high-temperature-reaction addition of a mixture containing 0.9 grams 
of catalyst dissolved in 15 grams of Solvent 1, is added through Feed Line 
B over a 30 minute period, and the reaction continued at 100.degree. C. 
for two hours. The resulting transparent solution is cooled to room 
temperature and stored for analysis and other use. The product has 57.32 
percent solids and a viscosity of 89.3 cP. The acrylic copolymer has a 
number-average molecular weight of 2535, a weight-average molecular weight 
of 4755, and a polydispersity of 1.88, as determined by gel permeation 
chromatography using polystyrene standards. 
Example 2 
In the same general manner described in Example 1, the reactor is charged 
with 50 grams of Solvent 1 while maintaining a nitrogen atmosphere in the 
reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). A 
mixture of monomers containing 121.1 grams 2-hydroxypropyl carbamate 
methacrylate (Preparation B), 143.59 grams of 2-ethylhexyl acrylate, 74.39 
grams of cyclohexyl methacrylate, 6.92 grams of methacrylic acid, and 196 
grams of Solvent 1 is added through Feed Line A, and a mixture of 80.7 
grams of Solvent 1 and 11.5 grams of t-amylperoxyacetate catalyst 
{Lupersol 555M60(60TS)} is added through Feed Line B with both additions 
taking place over a 4-hour time period. After the additions are completed, 
Feed Line A is flushed with 15 grams of Solvent 1, and the reaction 
mixture held at 140.degree. C. for an additional 30 minutes. Then the 
reactor is cooled to 100.degree. C., and a post high-temperature-reaction 
addition of a mixture containing 1.0 grams of catalyst dissolved in 17.3 
grams of Solvent 1 is added through Feed Line B over a 30 minute period, 
and the reaction continued at 100.degree. C. for two hours. The resulting 
transparent solution is cooled to room temperature and stored for analysis 
and other use. The product has 57.9 percent solids and a viscosity of 535 
cP. The acrylic copolymer has a number-average molecular weight of 2851, a 
weight-average molecular weight of 4969, and a polydispersity of 1.74, as 
determined by gel permeation chromatography using polystyrene standards. 
Example 3 
In the same general manner described in Example 1, the reactor is charged 
with 59.5 grams of Solvent 1 while maintaining a nitrogen atmosphere in 
the reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). A 
mixture of monomers containing 61.75 grams 2-hydroxypropyl carbamate 
methacrylate (Preparation B), 82.35 grams of a mixture of 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxy-propyl methacrylate (Preparation A), 
160.58 grams of 2-ethylhexyl acrylate, 98.82 grams of cyclohexyl 
methacrylate, 8.23 grams of methacrylic acid, and 99.5 grams of Solvent 1 
is added through Feed Line A, and a mixture of 96.0 grams of Solvent 1 and 
13.7 grams of t-amylperoxyacetate catalyst {Lupersol 555M60(60TS)} is 
added through Feed Line B with both additions taking place over a 4-hour 
time period. After the additions are completed, Feed Line A is flushed 
with 15 grams of Solvent 1 and the reaction mixture held at 140.degree. C. 
for an additional 30 minutes. Then the reactor is cooled to 100.degree. 
C., and a post high-temperature-reaction addition of a mixture containing 
1.19 grams of catalyst dissolved in 20.6 grams of Solvent 1 is added 
through Feed Line B over a 30 minute period, and the reaction continued at 
100.degree. C. for two hours. The resulting transparent solution is cooled 
to room temperature and stored for analysis and other use. The product has 
56.89 percent solids and a viscosity of 73.1 cP. The acrylic copolymer has 
a number-average molecular weight of 2268, a weight-average molecular 
weight of 3716, and a polydispersity of 1.64, as determined by gel 
permeation chromatography using polystyrene standards. 
Example 4 
In the same general manner described in Example 1, the reactor is charged 
with 50 grams of Solvent 1 while maintaining a nitrogen atmosphere in the 
reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). A 
mixture of monomers containing 41.52 grams of 2-hydroxyethyl methacrylate, 
60.55 grams 2-hydroxypropyl carbamate methacrylate (Preparation B), 134.94 
grams of 2-ethylhexyl acrylate, 102.07 grams of cyclohexyl methacrylate, 
6.92 grams of methacrylic acid, and 84 grams of Solvent 1 is added through 
Feed Line A and a mixture of 80.7 grams of Solvent 1 and 11.5 grams of 
t-amylperoxy-acetate catalyst {Lupersol 555M60(60TS)} is added through 
Feed Line B with both additions taking place over a 4-hour time period. 
After the additions are completed, Feed Line A is flushed with 17.3 grams 
of Solvent 1, and the reaction mixture held at 140.degree. C. for an 
additional 30 minutes. Then the reactor is cooled to 100.degree. C., and a 
post high-temperature-reaction addition of a mixture containing 1.0 grams 
of catalyst dissolved in 17.3 grams of solvent is added through Feed Line 
B over a 30 minute period, and the reaction continued at 100.degree. C. 
for two hours. The resulting transparent solution is cooled to room 
temperature and stored for analysis and other use. The product has 57.12 
percent solids and a viscosity of 300 cP. The acrylic copolymer has a 
number-average molecular weight of 3071, a weight-average molecular weight 
of 6061, and a polydispersity of 1.97, as determined by gel permeation 
chromatography using polystyrene standards. 
Example 5 
In the same general manner described in Example 1, the reactor is charged 
with 100 grams of Solvent 1 while maintaining a nitrogen atmosphere in the 
reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). A 
mixture of monomers containing 120.0 grams of a mixture of 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 1-isopropyl-2,2-dimethyl- 
3-hydroxy-propyl methacrylate (Preparation A), 103.5 grams of propylheptyl 
acrylate, 70.5 grams of cyclohexyl methacrylate, and 6.0 grams of 
methacrylic acid is added through Feed Line A, and a mixture of 70.0 grams 
of Solvent 1 and 10.0 grams of t-amylperoxyacetate catalyst {Lupersol 
555M60(60TS)} is added through Feed Line B with both additions taking 
place over a 4-hour time period. After the additions are completed, Feed 
Line A is flushed with 15 grams of Solvent 1, and the reaction mixture is 
held at 140.degree. C. for an additional 30 minutes. Then the reactor is 
cooled to 100.degree. C., and a post high-temperature-reaction addition of 
a mixture containing 0.9 grams of catalyst dissolved in 15.0 grams of 
Solvent 1 is added through Feed Line B over a 30 minute period, and the 
reaction continued at 100.degree. C. for two hours. The resulting 
transparent solution is cooled to room temperature and stored for analysis 
and other use. The product has 56.84 percent solids and a viscosity of 
83.3 cP. The acrylic copolymer has a number-average molecular weight of 
2436, a weight-average molecular weight of 3893, and a polydispersity of 
1.60, as determined by gel permeation chromatography using polystyrene 
standards. 
Example 6 
In the same general manner described in Example 1, the reactor is charged 
with 100 grams of Solvent 1 while maintaining a nitrogen atmosphere in the 
reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). A 
mixture of monomers containing 69.2 grams of a mixture of 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxy-propyl methacrylate (Preparation A), 
51.9 grams 2-hydroxypropyl carbamate methacrylate (Preparation B), 128.02 
grams of propylheptyl acrylate, 89.96 grams of cyclohexyl methacrylate, 
and 6.92 grams of methacrylic acid is added through Feed Line A, and a 
mixture of 80.7 grams of Solvent 1 and 11.5 grams of t-amylperoxyacetate 
catalyst {Lupersol 555M60(60TS)} was added through Feed Line B with both 
additions taking place over a 4-hour time period. After the additions are 
completed, Feed Line A is flushed with 15 grams of Solvent 1 and the 
reaction mixture held at 140.degree. C. for an additional 30 minutes. Then 
the reactor is cooled to 100.degree. C., and a post 
high-temperature-reaction addition of a mixture containing 1.0 grams of 
catalyst dissolved in 17.3 grams of Solvent 1 is added through Feed Line B 
over a 30 minute period and the reaction continued at 100.degree. C. for 
two hours. The resulting transparent solution is cooled to room 
temperature and stored for analysis and other use. The product has 56.84 
percent solids and a viscosity of 139 cP. The acrylic copolymer has a 
number-average molecular weight of 2545, a weight-average molecular weight 
of 4254, and a polydispersity of 1.67, as determined by gel permeation 
chromatography using polystyrene standards. 
Example 7 
In the same general manner described in Example 1, the reactor is charged 
with 59.5 grams of Solvent 1 while maintaining a nitrogen atmosphere in 
the reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). A 
mixture of monomers containing 69.00 grams N-butyl 2-hydroxyethyl 
carbamate (meth)acrylate, 60.0 grams of a mixture of 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxy-propyl methacrylate (Preparation A), 
94.5 grams isodecyl methacrylate, 70.5 grams isobornyl methacrylate and 
6.0 grams of methacrylic acid, and 99.5 grams of Solvent 1 is added 
through Feed Line A, and a mixture of 96.0 grams of Solvent 1 and 13.7 
grams of t-amylperoxyacetate catalyst {Lupersol 555M60(60TS)} is added 
through Feed Line B with both additions taking place over a 4-hour time 
period. After the additions are completed, Feed Line A is flushed with 15 
grams of Solvent 1 and the reaction mixture held at 140.degree. C. for an 
additional 30 minutes. Then the reactor is cooled to 100.degree. C., and a 
post high-temperature-reaction addition of a mixture containing 1.19 grams 
of catalyst dissolved in 20.6 grams of Solvent 1 is added through Feed 
Line B over a 30 minute period, and the reaction continued at 100.degree. 
C. for two hours. The resulting transparent solution is cooled to room 
temperature and stored for analysis and other use. The product has 57.49 
percent solids and a viscosity of 1500 cP. The acrylic copolymer has a 
number-average molecular weight of 5826, a weight-average molecular weight 
of 18545, and a polydispersity of 3.18, as determined by gel permeation 
chromatography using polystyrene standards. 
Examples 8- 14 
The acrylic-solution polymers of Examples 1-7 were formulated in a 3 to 1 
ratio by weight with Aminoplast 2 crosslinking agent. To each of these 
mixtures, 1.6 percent by weight of Catalyst 3, 0.5% Surfactant 1, and 0.5% 
Surfactant 2 are added and then well mixed. The resultant liquid coating 
formulations are applied to steel panels with a wire-wound draw-down rod 
and baked for 30 minutes in a 140.degree. C. oven. The resulting coatings 
have the following properties: 
______________________________________ 
EXAMPLE 
8 9 10 11 12 13 14 
______________________________________ 
Copolymer of 
1 2 3 4 5 6 7 
Example 
TEST 
GLOSS 85.8/ 85.9/ 86.1/ 
86.6/ 
85.8/ 
85.9/ 
86.7/ 
20.degree./60.degree. 
95.9 96.0 95.9 96.5 96.0 96.0 96.2 
ACID ETCH 73/ 69/ 74/ 70/ 69/ 73/ 68/ 
Visible/Severe 
84 80 86 82 77 84 78 
PENCIL HB/ HB/ HB/ B/ B/ HB/ F 
HARDNESS HB HB HB B B HB 
IMT 40/ 28/ 48/ 30/ 43/ 33/ 25/ 
Forward/Reverse 
&lt;5 &lt;5 &lt;5 &lt;5 &lt;5 &lt;5 &lt;5 
Viscosity of 
89.3 535 73.1 300 83.3 139 15 
Copolymer 
______________________________________ 
Example 15 
The liquid coating formulations from Example 8 and Example 9 are blended in 
a 1 to 1 ratio by weight and then coated and cured in the same manner as 
cured coatings from Example 8 through 14. The resulting coating has a 
Gloss (20.degree./60.degree.) of 86.1/96.2, an acid etch (visible/severe) 
of 72/84, a pencil hardness of HB/HB, and an impact (forward/reverse) of 
33/&lt;5 in-lbs. These results demonstrate that polymers containing only 
hindered hydroxyl functionality (Example 1 copolymer) can be successfully 
blended and cured with polymers containing O-carbamate functionality 
(Example 2 copolymer). 
Example 16 
An oligomeric copolymer that contains both free hydroxyl and free 
O-carbamate functionality is prepared from a 450-gram mixture of the 
Preparation A hindered-hydroxyl (meth)acrylate mixture, Preparation B 
hydroxyalkyl carbamate methacrylate, butyl acrylate, and methyl 
methacrylate. A chain transfer agent, 3-mercapto-1-propanol, is included 
in the monomer mixture. The initial pentyl propionate solvent is placed in 
a 2-liter, four-neck, glass reaction flask equipped with a mechanical 
stirrer, a Thermo-watch heat controller, a nitrogen sparger, a 
water-cooled condenser, and 500-milliliter and 125-milliliter addition 
funnels. A nitrogen sparge is maintained throughout the procedure. The 
solvent is heated to 125.degree. C., and the monomer mixture is fed by 
means of a piston pump to the flask over a four-hour period while 
controlling the temperature at 125.degree. C. Concurrently, the initiator 
mixture consisting of t-amyl peroxyacetate initiator dissolved in pentyl 
propionate is fed to the reaction flask by means of a second piston pump 
over the same time period. The two feeds are introduced into the reactor 
below the liquid surface and from opposite sides of the reactor. After 
completion of the feeding step, the monomer line is flushed with pentyl 
propionate, and the reaction is allowed to proceed for 30 minutes at 
125.degree. C. Then a second initiator feed consisting of a mixture of 
t-amyl peroxyacetate dissolved in pentyl propionate is fed to the reaction 
mass, and the reaction is allowed to proceed for an additional 2 hours at 
125.degree. C. The solution of oligomeric copolymer that contains both 
free hydroxyl and free O-carbamate functionality is cooled to room 
temperature and stored for future use. 
______________________________________ 
Initial pentyl propionate solvent, g 
150.0 
Monomer Mixture, g*** 
Preparation A hydroxyalkylacrylate methacrylate 
90.0 
Preparation B hydroxypropyl carbamate methacrylate 
90.0 
Butyl acrylate 135.0 
Methyl methacrylate 135.0 
3-Mercapto-1-propanol* 2.70 
Initiator Mixture, g 
Pentyl propionate 95.0 
t-Amylperoxyacetate** 27.0 
Monomer Line Flush 
Pentyl propionate, g 25.0 
Second Initiator Mixture, g 
Pentyl propionate 25.0 
t-Amylperoxyacetate** 2.5 
______________________________________ 
*Chain transfer agent 
**Lupersol 555M60(60TS) 
***The indicated Monomer Mixture is prepared, and 450 grams of the mixtur 
is used prepare the copolymer. 
Example 17 
Twenty grams of the oligomeric copolymer of Example 1, 3.8 grams of 
Aminoplast 1, 0.24 grams of Surfactant 1, 0.24 grams of Surfactant 2, 2.0 
grams of methyl amyl ketone solvent, and 0.5 gram of Catalyst 1 are placed 
in a glass container and well stirred. This thermally-curable coating 
system is coated onto a steel substrate with a No. 20 wire-wound rod and 
cured at 145.degree. C. for 30 minutes. A clear coating with good 
properties results. 
Example 18 
Thirty grams of the oligomeric copolymer of Example 1, 60 grams of 
3,4-epoxycyclohexyl 3,4-epoxycyclohexane carboxylate, and 3.0 grams of 
Photoinitiator 1 are added to an amber-colored glass container. The 
ingredients are well mixed and then applied to a steel panel by the 
draw-down method using a No. 20 wire-wound rod. The coated panel is then 
placed on a conveyor moving at 30 feet/minute and cured by passing it 
under a 300 watt-per-inch medium-pressure mercury-vapor lamp. A tack-free, 
clear coating results. 
Example 19 
Fifteen grams of the oligomeric copolymer of Example 1, 40 grams of 
3,4-epoxycyclohexyl 3,4-epoxycyclohexane carboxylate, 0.3 grams of 
diethylammonium trifiate catalyst, and 10 grams of methyl amyl ketone 
solvent are added to a glass container and well mixed. The mixture is 
coated onto a steel panel with a No. 22 wire-wound rod. The coated panel 
is allowed to air dry for 10 minutes, and then it is oven baked at 
140.degree. C. for 15 minutes. A clear, tack-free coating with good water 
resistance results. 
Example 20 
In the same general manner described in Example 1, the reactor is charged 
with 100 grams of Solvent 1 while maintaining a nitrogen atmosphere in the 
reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). 
300 grams of a mixture of monomers containing 40 percent 
N-butyl-2-hydroxyethyl carbamate (meth)acrylate, 36.5% 2-ethylhexyl 
acrylate, 21.5% cyclohexyl methacrylate, and 2 percent methacrylic acid, 
wherein said percentages are weight percentages, are added through Feed 
Line A and a mixture of 70.0 grams of Solvent 1 and 10.0 grams of 
t-amylperoxyacetate catalyst {Lupersol 555M60(60TS)} is added through Feed 
Line B with both additions taking place over a 4-hour time period. After 
the additions are completed, Feed Line A is flushed with 15 grams of 
Solvent 1 and the reaction mixture held at 140.degree. C. for an 
additional 30 minutes. Then the reactor is cooled to 100.degree. C., and 
a post high-temperature-reaction addition of a mixture containing 0.9 
grams of catalyst dissolved in 15.0 grams of solvent is added through Feed 
Line B over a 30 minute period and the reaction continued at 100.degree. 
C. for two hours. The resulting transparent solution is cooled to room 
temperature and stored for analysis and other use. The product has 58.27 
percent solids and a viscosity of 168 cP. The acrylic copolymer has a 
number-average molecular weight of 3108, a weight-average molecular weight 
of 5874, and a polydispersity of 1.89, as determined by gel permeation 
chromatography using polystyrene standards. 
Example 21 
Three parts by weight of the acrylic solution polymer of Example 20 is 
mixed with one part by weight with Aminoplast 2. To this mixture, 1.6 % by 
weight of Catalyst 3, 0.5% of Surfactant 3, and 0.5% of Surfactant 4 are 
added. The ingredients are well mixed, applied to steel substrate by the 
draw-down technique, and baked in a forced-air oven at 140.degree. C. for 
30 minutes. At room temperature, the coatings have the following 
properties: pencil hardness HB; impact resistance (direct/forward) 40/&lt;5 
in.lbs; gloss (20.degree./60.degree.) 88.1/97.1; acid etch resistance 
(visible/severe) 70/77; solvent resistance &gt;300 double methyl ethyl ketone 
rubs. 
Example 22 
In the same general manner described in Example 1, the reactor is charged 
with 100 grams of Solvent 1 while maintaining a nitrogen atmosphere in the 
reaction flask. A nitrogen atmosphere is maintained throughout the 
procedure. The reactor is then heated to reflux (.about.140.degree. C.). 
300 grams of a mixture of monomers containing 22.7% N-butyl-2-hydroxyethyl 
carbamate (meth)acrylate, 17.5% of a mixture of the isomers 
2,2,4-trimethyl-3-hydroxypentyl methacrylate and 
1-isopropyl-2,2-dimethyl-3-hydroxypropyl methacrylate (Preparation A), 
33.8% isodecyl methacrylate, 24.0% isobornyl methacrylate, and 2 percent 
methacrylic acid, wherein said percentages are weight percentages, are 
added through Feed Line A and a mixture of 70.0 grams of Solvent 1 and 
10.0 grams of t-amylperoxyacetate catalyst {Lupersol 555M60(60TS)} is 
added through Feed Line B with both additions taking place over a 4-hour 
time period. After the additions are completed, Feed Line A is flushed 
with 15 grams of Solvent 1 and the reaction mixture held at 140.degree. C. 
for an additional 30 minutes. Then the reactor is cooled to 100.degree. 
C., and a post high-temperature-reaction addition of a mixture containing 
0.9 grams of catalyst dissolved in 15.0 grams of solvent is added through 
Feed Line B over a 30 minute period and the reaction continued at 
100.degree. C. for two hours. The resulting transparent solution is cooled 
to room temperature and stored for analysis and other use. The product has 
59.0 percent solids and a viscosity of 6200 cP. The acrylic copolymer has 
a number-average molecular weight of 5787, a weight-average molecular 
weight of 22,020, and a polydispersity of 3.8, as determined by gel 
permeation chromatography using polystyrene standards. It is unexpected 
that a polymer of this molecular weight has a relatively low viscosity at 
59.0% solids. 
Example 23 
Three parts by weight of the acrylic solution polymer of Example 22 is 
mixed with one part by weight Aminoplast 2. To this mixture, 1.6% by 
weight of Catalyst 3, 0.5% by weight of Surfactant 3, and 0.5% by weight 
of Surfactant 4 are added. The ingredients are well mixed, applied to 
steel substrate by the draw-down technique, and baked in a forced-air oven 
at 140.degree. C. for 30 minutes. At room temperature, the coatings have 
the following properties: pencil hardness F; impact resistance 
(direct/forward) 20/&lt;5 in.lbs; gloss (20.degree./60.degree.) 86.2/96.1; 
acid etch resistance (visible/severe) 74/79; solvent resistance &gt;1000 
double methyl ethyl ketone rubs.