Coating compositions comprising an organosilane polymer and reactive dispersed polymers

A coating composition containing a film-forming organosilane polymer and a sterically dispersed macromolecular polymer having macromonomer chains which react with the silane functionality of the organosilane polymer. The coating compositon can be used as the clearcoat over a conventional pigmented basecoat, or as a basecoat or monocoat or primer when a suitable amount of pigment is incorporated therein. The coating composition provides improved chemical resistance and is not prone to cracking.

BACKGROUND OF THE INVENTION 
This invention is directed to a coating composition useful for providing a 
finish on a variety of substrates. In particular, this invention is 
directed to an organosilane composition which may be used for finishing 
automobiles and trucks. 
It is well known that consumers prefer automobiles and trucks with an 
exterior finish having an attractive aesthetic appearance, including high 
gloss and excellent DOI (distinctness of image). While ever more 
aesthetically attractive finishes have been obtained, deterioration of the 
finish over time, whereby the exterior finish of an automobile or truck 
loses its luster or other aspects of its aesthetic appearance, may be all 
the more noticeable. An increasingly observed cause of this deterioration 
is etching of the finish caused by exposure to environmental chemical 
attack. Chemicals that may cause etching of a finish include pollutants 
such as acid rain and chemical smog. 
In order to protect and preserve the aesthetic qualities of the finish on a 
vehicle, it is generally known to provide a clear (unpigmented) topcoat 
over a colored (pigmented) basecoat, so that the basecoat remains 
unaffected even on prolonged exposure to the environment or weathering. It 
is also generally known that alkoxysilane polymers, due to strong silane 
bonding when cured, exhibit excellent chemical resistance. Exemplary of 
prior art patents disclosing silane polymers for coating are U.S. Pat. No. 
4,368,297; U.S. Pat. No. 4 518 726; U.S. Pat. No. 4,043,953; and Japanese 
Kokai 57-12058. 
However, to applicants' knowledge, none of the previously disclosed 
alkoxysilane compositions for finishing automobiles or trucks have ever 
been placed into commercial use. It is believed that heretofore known or 
patented alkoxysilane coatings may suffer from certain unsolved problems 
or deficiencies. In particular, alkoxysilane coatings may exhibit a strong 
tendency to cracking. Such cracking may result from either stress or 
degradation by ultraviolet radiation. Such cracking would seriously and 
adversely affect long term durability and weatherability. 
There is a need for a commercially practical clearcoat finish having 
excellent appearance, including high gloss and DOI, that is also resistant 
to etching caused by chemical attack. To be commercially practical, such a 
clearcoat must not be prone to cracking. It is also desirable that such a 
clearcoat should be capable of being applied over a variety of basecoats 
and have excellent adhesion. 
SUMMARY OF THE INVENTION 
The invention is directed to a coating composition useful for finishing the 
exterior of automobiles and trucks and other substrates. The composition 
comprises: 
(a) from about 20 to 90% by weight, based on the weight of the binder 
solids, of a film-forming organosilane polymer having a weight average 
molecular weight of about 500-30,000 comprising 
(i) from about 30 to 95% by weight, based on the weight of a substantially 
epoxy free organosilane polymer, of ethylenically unsaturated monomers 
which do not contain a silane functionality and about 5 to 70% by weight 
ethylenically unsaturated monomers which contain a silane functionality; 
and 
(b) from about 10 to 60%, based on the weight of the binder solids, of 
particles of a dispersed polymer comprising: 
(i) a core comprising a macromolecular polymer which is not highly 
crosslinked and which has a molecular weight of at least 50,000 and which 
comprises a variety of different monomers; and 
(ii) a plurality of macromonomer chains, attached to the macromolecular 
polymer, having a weight average molecular weight of about 1,000 to 
30,0000, comprising 3 to 30% by weight, based on the weight of the 
macromonomer, of polymerized ethylenically unsaturated monomers which 
comprise a crosslinking functionality capable of forming a covalent bond 
with a silane functionality in said organosilane polymer and about 70 to 
95% by weight, based on the weight of the macromonomer, of at least one 
other polymerized ethylenically unsaturated monomer without a crosslinking 
functionality; and 
(c) from about 25 to 50% by weight, based on the weight of the composition, 
of a liquid organic carrier. 
The covalent bonding between crosslinking functionalities in said 
non-aqueous dispersion polymer and silane functionalities in said 
organosilane polymer is believed to reduce the tendency to cracking, after 
drying or curing, of the finish produced by coating a substrate with the 
present composition. 
Optionally, the composition may further comprise one or more non-silane 
film-forming solution polymers, preferably about 0 to 30% more preferably 
about 0 to 20% by weight, based on the weight of binder solids of the 
composition. 
In a preferred embodiment, the macromonomer chains of the dispersed polymer 
are covalently bonded at an end portion thereof to the macromolecular 
polymer. Further, it is preferred that about 5 to 20% of the monomers 
which comprise the macromonomer chain contain a crosslinking 
functionality. 
The invention also includes a process for coating a substrate with the 
above coating composition. The claimed invention further includes a 
substrate having adhered thereto a coating according to the above 
composition. 
The composition of the present invention is especially useful for forming a 
clear topcoat over a pigmented basecoat. Such a clear topcoat can be 
applied over a variety of colorcoats, such as water or organic solvent 
based colorcoats or powder colorcoats.

DETAILED DESCRIPTION OF THE INVENTION 
This invention provides a coating composition useful for finishing the 
exterior of automobile and truck bodies. Depending on its use, the present 
composition is capable of providing a coating which is durable, has 
excellent adhesion to basecoats, does not crack, does not deteriorate in 
terms of transparency under prolonged exposure to weather conditions, and 
imparts a superior glossy appearance for an extended period. Also, the 
coating composition offers a significant improvement over conventionally 
used coating compositions in terms of resistance to etching caused by 
environmental chemical attack. 
A typical automobile steel panel or substrate has several layers of 
coatings. The substrate is typically first coated with an inorganic 
rust-proofing zinc or iron phosphate layer over which is provided a primer 
which can be an electrocoated primer or a repair primer. A typical 
electrocoated primer typically comprises a cathodically deposited epoxy 
modified resin. A typical repair primer comprises an alkyd resin. 
Optionally, a primer surfacer can be applied over the primer coating to 
provide for better appearance and/or improved adhesion of the basecoat to 
the primer coat. A pigmented basecoat or colorcoat is next applied over 
the primer surfacer. A typical basecoat comprises a pigment, which may 
include metallic flakes in the case of a metallic finish, and polyester or 
acrylourethane as a film-forming binder. A clear topcoat (clearcoat) is 
then applied to the pigmented basecoat (colorcoat). The colorcoat and 
clearcoat are preferably deposited to have thicknesses of about 0.1-2.5 
mils and 1.0-3.0 mils, respectively. A composition according to the 
present invention, depending on the presence of pigments or other 
conventional components, may be used as a basecoat, clearcoat, or primer. 
However, a particularly preferred composition is useful as a clear topcoat 
to prevent environmental chemcical attack to the entire finish. A 
clearcoat composition of the present invention may be applied over a 
basecoat composition of the present invention. 
The film-forming portion of the present coating composition, comprising 
polymeric components, is referred to as the "binder" or "binder solids" 
and is dissolved, emulsified or otherwise dispersed in an organic solvent 
or liquid carrier. The binder solids generally includes all the normally 
solid polymeric non-liquid components of the composition. Generally, 
chemical additives such as stabilizers, catalysts, or pigments are not 
considered part of the binder solids. Non-binder solids other than 
pigments usually do not amount to more than about 5% by weight of the 
composition. In this disclosure, the term binder includes the organosilane 
polymer, the NAD polymer, and all other optional film-forming polymers. 
The applied coating composition suitably contains about 50-75% by weight 
of the binder solids and about 25-50% by weight of the organic solvent 
carrier. 
The binder of the coating composition contains about 20-90%, preferably 
40-80%, more preferably about 40% by weight of a film-forming silane 
containing polymer, hereafter also referred to as the silane polymer. A 
silane polymer having about 50%, more generally between 50% and 60%, 
silane monomer has been found to have improved mar and recoat adhesion. 
The silane polymer portion of the binder has a weight average molecular 
weight of about 1000-30,000, a number average molecular weight of about 
500-10,000. All molecular weights disclosed herein are determined by gel 
permeation chromatography using a polystyrene standard, unless stated 
otherwise. 
The silane polymer is the polymerization product of about 30-95%, 
preferably 40-60%, by weight ethylenically unsaturated non-silane 
containing monomers and about 5-70%, preferably 40-60%, by weight 
ethylenically unsaturated silane containing monomers, based on the weight 
of the organosilane polymer. Suitable ethylenically unsaturated non-silane 
containing monomers are alkyl acrylates, alkyl methacrylates and any 
mixtures thereof, where the alkyl groups have 1-12 carbon atoms, 
preferably 3-8 carbon atoms. 
Suitable alkyl methacrylate monomers used to form the organosilane polymer 
are methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl 
methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl 
methacrylate, octyl methacrylate, nonyl methacrylate, lauryl methacrylate 
and the like. Similarly, suitable alkyl acrylate momomers include methyl 
acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl 
acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, 
lauryl acrylate and the like. Cycloaliphatic methacrylates and acrylates 
also can be used, for example, such as trimethylcyclohlexyl methacrylate, 
trimethylcyclohexl acrylate, iso-butyl methacrylate, t-butyl cyclohexyl 
acrylate, or t-butyl cyclohexyl methacrylate. Aryl acrylate and aryl 
methacrylates also can be used, for example, such as benzyl acrylate and 
benzyl methacrylate. Of course, mixtures of two or more of the above 
mentioned monomers are also suitable. 
In addition to alkyl acrylates or methacrylates, other polymerizable 
monomers, up to about 50% by weight of the polymer, can be used in the 
acrylosilane polymer for the purpose of achieving the desired hardness, 
appearance, mar resistance and the like. Exemplary of such other monomers 
are styrene, methyl styrene, acrylamide, acrylonitrile, methacrylonitrile, 
and the like. Styrene can be used in the range of 0-50% by weight. The 
silane polymer is substantially epoxy free, preferably essentially free of 
epoxy groups as crosslinking groups. The disclosed embodiment does not use 
epoxy groups in the silane polymer. 
A suitable silane containing monomer useful in forming the acrylosilane 
polymer is an alkoxysilane having the following structural formula: 
##STR1## 
wherein R is either CH.sub.3, CH.sub.3 CH.sub.2, CH.sub.3 O, or CH.sub.3 
CH.sub.2 O; R.sub.1 and R.sub.2 are CH.sub.3 or CH.sub.3 CH.sub.2 ; and 
R.sub.3 is either H, CH.sub.3, or CH.sub.3 CH.sub.2 ; and n is 0 or a 
positive integer from 1 to 10. Preferably, R is CH.sub.30 or CH.sub.3 
CH.sub.2 O and n is 1. 
Typical examples of such alkoxysilanes are the acrylatoalkoxy silanes, such 
as gamma-acryloxypropyltrimethoxy silane and the methacrylatoalkoxy 
silanes, such as gamma-methacryloxypropyltrimethoxy silane, and 
gamma-methacryloxypropyltris(2-methoxyethoxy) silane. 
Other suitable alkoxy silane monomers have the following structural 
formula: 
##STR2## 
wherein R, R.sub.1 and R.sub.2 are as described above and n is a positive 
integer from 1 to 10. 
Examples of such alkoxysilanes are the vinylalkoxy silanes, such as vinyl 
trimethoxy silane, vinyl triethoxy silane and vinyl 
tris(2-methoxyethoxy)silane. 
Other suitable silane containing monomers are ethylenically unsaturated 
acyloxysilanes, including acrylatoxy silane, methacrylatoxy silane and 
vinylacetoxy silanes, such as vinylmethyldiacetoxy silane, 
acrylatopropyltriacetoxy silane, and methacrylatopropyltriacetoxy silane. 
Of course, mixtures of the above-mentioned silane containing monomers are 
also suitable. 
Consistent with the above mentioned components of the silane polymer, an 
example of an organosilane polymer useful in the coating composition of 
this invention may contain the following constituents: about 15-25% by 
weight styrene, about 30-60% by weight methacryloxypropyltrimethoxy 
silane, and about 25-50% by weight trimethylcyclohexyl methacrylate. 
One preferred acrylosilane polymer consists of about 20% styrene, 55% of a 
silane monomer such as methacryloxypropyltrimethoxysilane, about 15% 
methyl methacrylae, about 5% butyl methacrylate, and about 5% 
ethylhexylacrylate. Another preferred acrylosilane polymer contains about 
30% by weight styrene, about 50% by weight methacryloxypropyl trimethoxy 
silane, and about 20% by weight of nonfunctional acrylates or 
methacrylates such as trimethylcyclohexyl methacrylate, butyl acrylate, 
and iso-butyl methacrylate and any mixtures thereof. 
Silane functional macromonomers also can be used in forming the silane 
polymer. These macromonomers are the reaction product of a silane containg 
compound, having a reactive group such as epoxide or isocyanate, with an 
ethylenically unsaturated non-silane containing monomer having a reactive 
group, typically a hydroxyl or an epoxide group, that is co-reactive with 
the silane monomer. An example of a useful macromonomer is the reaction 
product of a hydroxy functional ethylenically unsaturated monomer such as 
a hydroxyalkyl acrylate or methacrylate having 1-4 carbon atoms in the 
alkyl group and an isocyanatoalkyl alkoxysilane such as isocyanatopropyl 
triethoxysilane. 
Typical of such above mentioned silane functional macromonomers are those 
having the following structural formula: 
##STR3## 
wherein R, R.sub.1, and R.sub.2 are as described above; R.sub.4 is H or 
CH.sub.3, R.sub.5 is an alkylene group having 1-8 carbon atoms and n is a 
positive integer from 1-8. 
Additional to the organosilane polymer, other film-forming and/or 
crosslinking solution polymers may be included in the present application. 
Examples include conventionally known acrylics, cellulosics, aminoplasts, 
urethanes, polyesters, epoxides or mixtures thereof. 
The silane polymer may optionally contain hydroxy containing monomers, for 
example, as dislosed in international disclosure no. WO 91/16383 based on 
International Application No. PCT/JP91/00559, which may improve recoat 
adhesion. However, in the preferred embodiment, the binder of the coating 
composition contains about 20-90%, preferably 40-80%, by weight of a 
film-forming polymeric polyol, that is a separate polymer from the silane 
polymer. Such a polyol suitably has a weight average molecular weight of 
about 1500-20,000, preferably 1500-12,000, and a hydroxyl number of about 
40-200, preferably 60-140. Suitable polyols include acrylics, polyesters, 
acrylourethanes, polyester urethanes, polyurethane polyesters, or 
polyurethanes, polyester urethane silanes, or combinations thereof. Graft 
polymers of different hydroxy containing resins are also suitable. 
A suitable polyol is a polyester or polyesterurethane copolymer thereof 
having a hydroxy number of about 10 to 200 and a weight average molecular 
weight of about 6,000-30,000. Such copolymers are well known to those 
skilled in the art and the particular monomer make-up can be selected to 
achieve the desired properties for a particular application, for example, 
depending on whether increased flexibility or increased mar resistance is 
desired. Especially preferred copolymers are polyester urethanes. Examples 
of polyesterurethanes are disclosed in U.S. Pat. No. 4,810,759, European 
Patent Application 0 409 301 A2, European Patent Application 409 300 A, 
all hereby incorporated by reference. 
Examples of polyesters which may be employed in this invention are suitably 
prepared from linear or branched chain diols, including ether glycols, or 
mixtures thereof or mixtures of diols and triols, containing up to and 
including 8 carbon atoms, in combination with a dicarboxylic acid, or 
anhydride thereof, or a mixture of dicarboxylic acids or anhydrides, which 
acids or anhydrides contain up to and including 12 carbon atoms, wherein 
at least 75% by weight, based on the weight of dicarboxylic acid, is an 
aliphatic dicarboxylic acid. A commericially available conventional 
polyester, which may be employed in the present composition, is Rucoflex 
1015S-120 polyester, having a hydroxy number of 125 and composed of one 
mole of a glycol, 2 moles of adipic acid, and 2 moles of neopentyl glycol. 
Polyester urethanes suitably are a reaction product of a hydroxyl 
terminated polyester and a polyisocyanate, preferably, an aliphatic or 
cycloaliphatic diisocyanate. 
In the present composition, the polyesters or polyester copolymers such as 
urethanes have a hydroxyl number of about 10-200 and preferably 40-160 and 
have a weight average molecular weight of about 6,000-30,000, preferably 
9,000-17,000, and a number average molecular weight of about 2,000-5,000, 
preferably 3,000-4,000. All molecular weights mentioned herein are 
measured using gel permeation chromatography using polyethyl methacrylate 
as a standard. 
Representative saturated and unsaturated polyols that may be reacted to 
form a polyester include alkylene glycols such as neoptyl glycol, ethylene 
glycol, propylene glycol, butane diol, pentane diol, 1,6-hexane diol, 
2,2-dimethyl-1,3-dioxolane-4-methanol, 4-cyclohexane dimethanol, 
2,2-dimethyl 1,3-propanediol, 2,2-bis(hydroxymethyl)propionic acid, and 
3-mercapto-1,2-propane diol. Neopentyl glycol is preferred to form a 
flexible polyurethane that is soluble in conventional solvents 
Polyhydric alcohols, having at least three hydroxyl groups, may also be 
included to introduce branching in the polyester. Typical polyhydric 
alcohols are trimethylol propane, trimethylol ethane, pentaerythritol, 
glycerin and the like. Trimethylol propane is preferred, in forming a 
branched polyester. 
The carboxylic acids include the saturated and unsaturated polycarboxylic 
acids and the derivatives thereof. Aliphatic dicarboxylic acids that can 
be used to form the polyester are as follows: adipic acid, sebacic acid, 
succinic acid, azelaic acid, dodecanedioic acid and the like. Prefered 
dicarboxylic acids are a combination of dodecandioic acid and azelaic 
acid. Aromatic polycarboxylic acids include phthalic acid, isophthalic 
acid, terephthalic acid, and the like. Anhydrides may also be used, for 
example, maleic anhydride, phthalic anhydride, trimellitic anhydride, and 
the like. 
Typical polyisocyanates that may be used to form the polyester urethane are 
as follows: isophorone diisocyanate which is 
3-isocyanatemethyl-3,5,5-trimethylcyclohexyl-isocyanate, 
propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, 
butylene-1,3-diisocyanate, hexamethylene diisocyanate, 
methyl-2,6-diisocyanate, methyl-2,6-diisocyanate caproate, octamethlyene 
diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, nonamethylene 
diisocyante, 2,2,4-trimethylhexamethylene diisocyanate, decamethylene 
diisocyanate, 2,11-diisocyano-dodecane and the like, meta-phenylene 
diisocyanate, para-phenylene diisoxyanate, toluene-2, 4-diisocyanate, 
toluene-2,6-diisocyanate, xylene-2, 4-diisocyanate, 
xylene-2,6-diisocyanate, dialkyl benzene diisocyanates, such as 
methylpropylbenzene diisocyanate, methylethylbenzene diisocyanate, and the 
like: 2,2'-biphenylene diisocyanate, 3,3'-biphenylene diisocyanate, 
4,4'-biphenylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene 
diisocyanate, and the like; methylene-bis(4-phenyl isocyanate), 
ethylene-bis(4-phenyl isocyanate), isopropylidene-bis(4-phenyl 
isocyanate), butylene-bis(4-phenylisocyanate), and the like; 
2,2'-oxydiphenyl diisocyanate, 3,3'-oxydiphenyl diisocyanate, 
4,4'-oxydiphenyl diisocyanate, 2,2'-ketodiphenyl diisocyanate, 
3,3'-ketodiphenyl diisocyanate, 4,4'-ketodiphenyl diisocyanate, 
2,2'-thiodiphenyl diisocyanate, 3,3'-thiodiphenyl diisocyanate, 
4,4'-thiodiphenyl diisocyanate, and the like; 2,2'-sulfonediphenyl 
diisocyanate, 3,3'-sulfonediphenyl diisocyanate, 4,4'-sulfonediphenyl 
diisocyanate, and the like; 2,2'-methylene-bis(cyclohexyl isocyanate), 
3,3'-methylene-bis(cyclohexyl isocyanate), 4,4'-methylene-bis(cyclohexyl 
isocyanate), 4,4'-ethylene-bis(cyclohexyl isocyanate), 
4,4'-propylene-bis-(cyclohexyl isocyanate), 
bis(paraisocyano-cyclohexyl)sulfide, bis(para-isocyano-cyclohexyl)sulfone, 
bis(para-isocyano-cyclohexyl)ether, bis(para-isocyano-cyclohexyl)diethyl 
silane, bis(para-isocyano-cyclohexyl)diphenyl silane, 
bis(para-isocyano-cyclohexyl)ethyl phosphine oxide, 
bis(para-isocyano-cyclohexyl)phenyl phosphine oxide, 
bis(para-isocyano-cyclohexyl)N-phenyl amine, 
bis(para-isocyano-cyclohexyl)N-methyl amine, 3,3'-dimethyl-4,4'-diisocyano 
biphenyl, 3,3'-dimethoxy-biphenylene diisocyanate, 
2,4-bis(b-isocyano-t-butyl)toluene, 
bis(para-b-isocyano-t-butyl-phenyl)ether, 
para-bis(2-methyl-4-isocyanophenyl)benzene, 3,3-diisocyano adamantane, 
3,3-diisocyano biadamantane, 3,3-diisocyanoethyl-1'-biadamantane, 
1,2-bis(3-isocyano-propoxy)ethane, 2,2-dimethyl propylene diisocyanate, 
3-methoxy-hexamethylene diisocyanate 2,5-dimethyl heptamethylene 
diisocyanate, 5-methyl-nonamethylene diisocyanate, 
1,4-diisocyano-cyclohexane, 1,2-diisocyano-octadecane, 
2,5-diisocyano-1,3,4-oxadiazole, OCN(CH.sub.2).sub.3 O(CH.sub.2).sub.2 
O(CH.sub.2).sub.3 NCO, OCN(CH.sub.2).sub.3 NCO or the following: 
##STR4## 
Aliphatic diisocyanates are suitable, forming urethanes that have excellent 
weatherability. One aliphatic diisocyanate that is particularly preferred 
is a mixture of 2,2,4-trimethyl hexamethylene diisocyanate and 
2,4,4-trimethyl hexamethylene diisocyanate. One cycloaliphatic 
diisocyanate that may be preferred is 
4,4-methylene-bis(cyclohexylisocyanate). 
A suitable polyester urethane is the reaction product of 
trimethylhexamethylene diisocyanate and a hydroxy terminated polyester of 
neopentyl glycol, trimethylol propane, azelaic acid and dodecanedioic 
acid. Another suitable polyester urethane is the reaction product of 
4,4-methylene-bis(cyclohexyl isocyanate) and a hydroxy terminated 
polyester of 1,6 hexane diol, cyclohexane diethanol, trimethylol propane 
and azelaic acid. 
A polyester may be prepared by conventional techniques in which the 
component polyols and carboxylic acids and solvent are esterified at about 
110.degree.-250.degree. C. for about 1-10 hours to form a polyester. To 
form a polyester urethane, a polyisocyanate may then be added and reacted 
at about 100.degree.-200.degree. C. for about 15 minutes to 2 hours. 
In preparing the polyester, an esterification catalyst is typically used. 
Conventional catalysts include benzyl trimethyl ammonium bydroxide, 
tetramethyl ammonium chloride, organic tin compounds, such as dibutyl tin 
diaurate, dibutyl tin oxide stannous octoate and the like, titanium 
complexes and litharge. About 0.1-4% by weight, based on the total weight 
of the polyester, of the catalyst is typically used. The aforementioned 
catalysts may also be used to form the polyester urethane. 
The stoichiometry of the polyester preparation is controlled by the final 
hydroxyl number and by the need to obtain a product of low acid number; an 
acid number below 10 is preferable. The acid number is defined as the 
number of milligrams of potassium hydroxide needed to neutralize a 1 gram 
sample of the polyester. Additional information on the preparation of 
polyester urethanes is disclosed in the above cited patents incorporated 
by reference. 
Another suitable type of polyol is an acrylic polyol solution polymer, 
preferably in the amount of about 15% by weight of binder. Such a polyol 
is suitably the polymerization product of monomers which may include any 
of the aforementioned alkyl acrylates and/or methacrylates and, in 
addition, hydroxy alkyl acrylates or methacrylates. This acrylic polyol 
polymer preferably has a hydroxyl number of about 50-200 and a weight 
average molecular weight of about 1,000-200,000 and preferably about 
1,000-20,000, more preferably about 6000. Preferably the Tg is from 
2.degree. to 18.degree. C. 
To provide the hydroxy functionality in the acrylic polyol, up to about 90% 
by weight, preferably 20 to 50%, of the polyol comprises hydroxy 
functional polymerized monomers. Suitable monomers include hydroxy alkyl 
acrylates and methacrylates, for example, hydroxy ethyl acrylate, hydroxy 
propyl acrylate, hydroxy isopropyl acrylate, hydroxy butyl acrylate, 
hydroxy ethyl methacrylate, hydroxy propyl methacrylate, hydroxy isopropyl 
methacrylate, hydroxy butyl methacrylate, and the like, and mixtures 
thereof. 
Other polymerizable non-hydroxy containing monomers may be included in the 
acrylic polyol polymer, in an amount up to about 90% by weight, preferably 
50 to 80%. Such polymerizable monomers include, for example, styrene, 
methylstyrene, acrylamide, acrylonitrile, methacrylonitrile, 
methacrylamide, methylol methacrylamide and methylol acrylamide and the 
like, and mixtures thereof. 
One example of an acrylic polyol polymer comprises about 10-20% by weight 
of styrene, 40-60% by weight of alkyl methacrylate or acrylate having 1-6 
carbon atoms in the alkyl group, and 10-50% by weight of hydroxy alkyl 
acrylate or methacrylate having 1-4 carbon atoms in the alkyl group. One 
such polymer contains about 15% by weight styrene, about 29% by weight 
iso-butyl methacrylate, about 20% by weight 2-ethylhexyl acrylate, and 
about 36% by weight hydroxy propylacrylate. 
A key component of the coating composition of the present invention is, in 
addition to the above polymeric components, a dispersed polymer. Polymers 
dispersed in an organic (substantially non-aqueous) medium have been 
variously referred to, in the art, as a non-aqueous dispersion (NAD) 
polymer, a microgel, a non-aqueous latex, or a polymer colloid. See 
generally, Poehlin et al., editor, SCIENCE AND TECHNOLOGY OF POLYMER 
COLLOIDS, Volume 1, pages 40-50 (1983); El-Asser, editor, FUTURE 
DIRECTIONS IN POLYMER COLLOIDS, pages 191-227 (1987); Barrett, DISPERSION 
POLYMERIZATION IN ORGANIC MEDIA (John Wiley 1975). See also U.S. Pat. Nos. 
4,147,688; 4,180,489; 4,075,141; 4,415,681; and 4,591,533, hereby 
incorporated by reference. Microgel particles, necessarily cross-linked, 
have been used for years as impact modifiers for plastics, as rheology 
controllers for coatings, and in basecoats, to permit wet-on-wet 
application of paints. 
In general, the dispersed polymer of the present invention is characterized 
as a polymer particle dispersed in an organic media, which particle is 
stabilized by what is known as steric stabilization. According to the 
prior art, steric stabilization is accomplished by the attachment, 
commonly by adsorption, of a solvated polymeric or oligomeric layer at the 
particle medium interface. The problem of providing a steric barrier has 
been considered in two parts: first, the selection of the soluble polymer 
which comprises the solvate sheath surrounding each particle and, 
secondly, the method of attaching or anchoring this polymer to the 
particle surface. The most widely known type of stabilizer used in 
dispersed polymers had been based on block or graft copolymers, one 
component of which is the soluble stabilizing portion and the other 
portion, often termed the anchor, is insoluble in the continuous phase and 
is adsorbed on or is absorbed into the disperse phase. It is also known 
that to increase the stability of the a dispersed polymer, particularly to 
strong solvents, or to ensure that the stabilizer is not desorbed or 
displaced, the anchor group may be covalently linked to the particle. This 
has been achieved by incorporating into the anchor group a reactive group, 
for example a glycidyl group which can react with a complementary group in 
the dispersed polymer, for example a carboxylic acid. 
In the dispersed polymers of the present composition, the dispersed phase 
or particle, sheathed by a steric barrier, will be referred to as the 
"macromolecular polymer" or "core." The stabilizer forming the steric 
barrier, attached to this core, will be referred to as the "macromonomer 
chains" or "arms." 
The dispersed polymers of the present invention solve the problem of 
cracking heretofor associated with silane coatings. These dispersed 
polymers, to reduce cracking to the desired minimum, must be used in 
higher amounts than dispersed polymers are typically used for other 
purposes. For example, while microgels have been used in basecoats for 
flow control at levels of not more than about 5%, the present dispersed 
polymers are used in an amount varying from about 10 to 60%, preferably 
about 15 to 40%, most preferably about 20% by weight of the total solids 
binder in the composition. Hight levels of dispersed polymer may give 
better crack resistance but may also have an adverse tradeoff regarding 
appearance. The ratio of the silane polymer component to the dispersed 
polymer component of the composition suitably ranges from 5:1 to 1:2, 
preferably 4:1 to 1:1. These relatively high concentrations of dispersed 
polymers, in the present composition, is made possible by the presence of 
reactive groups on the arms of the dispersed polymer, which reactive 
groups make the polymers compatible with the continuous phase of the 
system. 
The dispersed polymer contains about 10-90%, preferably 50-80% by weight, 
based on the weight of the dispersed polymer, of a high molecular weight 
core having a weight average molecular weight of at least about 50,000. 
While a range of 50,000-500,000 is suitable, nominally infinite weight 
average molecular weights or also suitable. The preferred average particle 
(core) size is at least 0.1, preferably 0.1 to 0.5 microns. The core 
preferably is at least 50% by weight of the dispersed polymer, more 
preferably 60-80% by weight of the dispersed polymer. The arms, attached 
to the core, make up about 90-10%, preferably 20-50%, most preferably less 
than 40% by weight of the dispersed polymer, and has a weight average 
molecular weight of about 1,000-30,000, preferably 1,000-10,000. 
Preferably, the macromolecular core of the dispersed polymer is comprised 
of a variey of different polymerized ethylenically unsaturated monomers. 
Suitable monomers include styrene, alkyl acrylate or methacrylate, 
ethylenically unsaturated monocarboxylic acid, and/or silane containing 
monomomers. Such monomers as methyl methacrylate contribute to a high Tg 
(transition glass temperature) dispersed polymer, whereas such "softening" 
monomers as butyl acrylate or 2-ethylhexylacrylate contribute to a low Tg 
dispersed polymer. Other optional monomers are hydroxyalkyl acrylates or 
methacrylates or acrylonitrile. It is noted that such functional groups as 
hydroxy can react with silane groups in the organosilane polymer to 
produce more bonding in the composition. If the core is crosslinked, allyl 
acrylate or allyl methacrylate, which crosslink with each other, can be 
used or an epoxy functional monomer such as glycidyl acrylate or 
methacrylate can be used, which will react with monocarboxylic acid 
functional ethylenically unsaturated monomers to crosslink the core. 
Preferably, there is silane functionality, for crosslinking purposes, in 
the case, which functionality may be provided by a small amount of one or 
more of the silane containing monomers mentioned above with respect to the 
film forming organosilane polymer. Suitably, the silane functionality is 
the primary or major means, preferably the sole means, of crosslinking in 
the core. Suitably about 2 to 10%, preferably about less than 5% of the 
monomers making up the macromolecular core are silane monomers capable of 
crosslinking between themselves. Thus, crosslinking occurs by siloxane 
bonding (--Si--O--Si--). This silane crosslinking enables the core to 
behave as a non-crosslinked polymer before cure for good flow during 
application, resulting in improved appearance. The core can crosslink 
during and after curing, upon exposure to humidity and heat during curing 
and/or exposure to humidity in the environment after curing. A further 
advantage of silane being present in the core is that the cured film does 
not blush when exposed to humidity, which blushing was found to occur 
without the presence of silane. If the core is pre-crosslinked (before 
curing) by other means, such as acid/epoxy or diacrylates, then humidity 
sensitivity may be eliminated but the system may have poor flow and 
appearance. 
The reason that the dispersed polymer in the present coating composition 
eliminates the cracking problem which silane-containing film forming 
polymers are otherwise prone is not known for certain. Although not 
wishing to be bound by theory, one hypothesis is that the dispersed 
polymer provides high density, high molecular weight reinforcement, which 
reinforcement is integrated with the matrix of the film. This enables the 
coating to withstand stress and/or U.V. degradation. Such reinforcement 
also may prevent the propogation of cracking. Another hypothesis is that 
the dispersed polymer, with its macromolecular coil or core, provides a 
certain amount of sponginess and flexibilty to the coating, that is, the 
macromolecular core may be able to contract and expand, especially with 
low volatile organic content. This so-called sponginess may compensate to 
some extent for the points, or concentrated areas, of silane bonding. 
Silane crosslinking tends to become tightly bound, since each silane 
moiety or group potentially can be crosslinked at three sites and a number 
of silane moieties can become extended in a silane ladder or matrix. 
Without the dispersed polymer, an over concentration of silane 
crosslinking may result in stress cracking. 
As mentioned above, it is preferred that the macromolecular core of the 
dispersed polymer has a low amount of crosslinking within the 
macromolecular core and, most preferably, the core has zero 
pre-crosslinking. This means there is no crosslinking in solution, before 
the composition is cured or baked. The more the core is crosslinked, the 
less its sponginess. Also, without crosslinking, the macromolecular core 
is capable of uncoiling to some extent and therefore has a better tendency 
to flow, an advantage in spray application of the coating composition. 
Some degree of crosslinking may be desirable, for example, in order to 
derive the macromolecular core polymer from shorter chains. However, in 
general, the greater the crosslinking, the more tightly bound together the 
polymer and the less its ability to prevent cracking of the coating. 
Because limited or no pre-crosslinking in the macromolecular core of the 
dispersed polymer is desired, dispersed polymers which are highly 
crosslinked, namely star polymers disclosed in U.S. Pat. No. 4,810,756 to 
Spinelli, would not be equivalent to dispersed polymers of the present 
invention. 
A distinctive feature of the dispersed polymers of the present invention is 
the presence of macromonomer arms which are reactive, that is these arms 
have numerous reactive groups, referred to as "crosslinking 
functionalities," which are adapted to react with the organosilane polymer 
of the present composition. It is not known with certainty what portion of 
the these functional groups do, in fact, react with the organosilane 
polymer, because of the numerous and complicated sets of reactions which 
may occur during baking and curing of the composition, especially if 
additional film-forming binders are present. However, it may be said that 
a substantial portion of these functionalities in the arms, preferably the 
majority therof, do in actuality react and crosslink with the film-former 
of the composition, which in some cases may exclusively consist of an 
organosilane polymer. Of course, if additional film-forming polymers are 
present, for example, a polyol, then the arms may react with film-formers 
other than the organosilane polymer. Suitably, about 3 to 30 % of the 
monomers which make up the macromonomer arms have reactive crosslinking 
functional groups. Preferably about 10 to 20% of the monomers have such 
reactive groups. Dispersed polymers having reactive arms have been 
disclosed in U.S. Pat. No. 4,591,533 to Antonelli et al. 
The arms of the dispersed polymer should be anchored securely to the 
macromolecular core. For this reason, the arms preferably are anchored by 
covalent bonds. The anchoring must be sufficent to hold the arms to the 
dispersed polymer after they react with the film-former polymer. For this 
reason, the conventional method of anchoring by adsorption of the backbone 
portion of a graft polymer may provide insufficent anchoring. 
As indicated above, the arms or macromonomers of the dispersed polymer 
serve to prevent the core from flocculating by forming what is referred to 
in the art as a steric barrier. The arms, typically in contrast to the 
macromolecular core, are believed capable, at least temporarily, of being 
solvated in the organic solvent carrier or media of the composition. They 
may therefore be in a chain-extended configuration and their crosslinking 
functional groups are therefore relatively readily available to reaction 
with the silane groups of the film forming silane containing polymer. Such 
arms suitably comprise about 3 to 30%, preferably 10 to 20%, by weight, 
based on the weight of macromonomer, of polymerized ethylenically 
unsaturated hydroxy, epoxide, silane, acrylamide (including 
methacrylanide) acid, anhydride, isocyanate or other crosslinking 
functionality containing monomers, or combinations thereof, and about 
70-95% by weight, based on the weight of the macromonomer, of at least one 
other polymerized ethylenically unsaturated monomer without such 
crosslinking functionality. Preferably the crosslinking functionality is a 
hydroxy, silane or epoxy containing monomer, since such reactive groups 
can be utilized in one package systems. When the crosslinking 
functionality is an acid, anhydride or isocyanate, then a two package 
system, with the dispersed polymer in a first package and the organosilane 
in a second package, is generally required. Combinations of the 
above-mentioned crosslinking functional groups are also suitable, although 
it is noted that hydroxy and silane groups have limited compatibility and 
are preferably not on the same macromonomer chain. 
As an example, the macromonomer arms attached to the core may contain 
polymerized monomers of alkyl methacrylate, alkyl acrylate, each having 
1-12 carbon atoms in the alkyl group, as well as glycidyl acrylate or 
glycidyl methacrylate or ethylenically unsaturated monocarboxylic acid for 
anchoring and/or crosslinking. Typically useful hydroxy containing 
monomers are hydroxy alkyl acrylates or methacrylates as described above. 
A preferred composition for a dispersed polymer that has hydroxy 
functionality comprises a core consisting of about 25% by weight hydroxy 
ethyl acrylate, about 4% by weight methacrylic acid, about 36.5% by weight 
methyl methacrylate, about 18% by weight methyl acrylate, about 1.5% by 
weight glycidyl methacrylate and about 15% styrene. The macromonomer 
attached to the core contains 97.3% by weight prepolymer and about 2.7% by 
weight glycidyl methacrylate, the latter for crosslinking or anchoring. A 
preferred prepolymer contains about 30% by weight butyl methacrylate, 
about 30% by weight butyl methacrylate, about 30% by weight butyl 
acrylate, about 10% by weight hydroxyethyl acrylate, about 2% by weight 
glycidyl methacrylate, and about 15% by weight styrene. 
The dispersed polymer may be produced by conventionally known procedures. 
For example, it has been disclosed that such polymers may be produced by a 
process of dispersion free radical polymerization of monomers, in an 
organic solvent, in the presence of a steric stabilizer for the particles. 
The procedure has been described as basically one of polymerizing the 
monomers in an inert solvent in which the monomers are soluble but the 
resulting polymer is not soluble, in the presence of a dissolved 
amphiteric stabilizing agent. Such procedures have been extensively 
disclosed in both the patent and non-patent literature, for example, see 
the above cited references regarding dispersed polymers in general, or 
U.S. Pat. No. 4,220,679 and PAINT AND SURFACE COATING: THEORY AND 
PRACTICE, ed. R. Lambourne (Ellis Horwood Limited 1987). As illustrated in 
the examples below, the macromonomer arms can be prepared by cobalt 
catalyzed special chain transfer (SCT) polymerization, group transfer 
polymerization (GTP), or free radical polymerization. 
Optionally, the present coating composition may optionally further include, 
particularly in conjunction with an optional polyol polymer, an additional 
crosslinking agent, for example conventionally known monomeric or 
polymeric alkylated melamine formaldehyde resin that is partially or fully 
alkylated. One preferred crosslinking agent is a methylated and butylated 
or isobutylated melamine formaldehyde resin that has a degree of 
polymerization of about 1-3. Generally, this melamine formaldehyde resin 
contains about 50% butylated groups or isobutylated groups and 50% 
methylated groups. Such crosslinking agents typically have a number 
average molecular weight of about 300-600 and a weight average molecular 
weight of about 500-1500. Examples of commercially available resins are 
"Cymel" 1168, "Cymel"1161, "Cymel" 1158, "Resimine" 4514 and "Resimine" 
354. A preferred melamine, for a good balance of properties, is a fully 
aklylated resin such as "Cymel 1168." The crosslinking agent is suitably 
used in the amount of about 5-50% by weight, based on the weight of the 
binder of the composition. More preferably, the level of melamine is about 
15%, about equal to the level of the polyol. Lower levels of melameine may 
have an advantage with regard to hardness and appearance. Other 
crosslinking agents are urea formaldehyde, benzoquanamine formaldeyde and 
blocked polyisocyanates. 
Another optional component, in another embodiment of the present invention, 
is one or more silsesquioxanes. Such silsesquioxanes may suitably be 
present in the amount of 1 to 15% by weight, based on the weight of the 
binder, preferably about 10%, to improve the etch resistance when used to 
provide a coating. Silsesquioxane compounds are oligomers that may be 
visualized as composed of tetracylosiloxane rings, for example as follows: 
##STR5## 
The number of repeating units is suitably 2 or more, preferably 2 to 12. 
Exemplary compounds, commercially available from Petrarch Systems, Inc. 
(Bristol, Pa.) include polymethylsilsesquioxane, 
polyphenylpropylsilsesquioxane, polyphenylsilsesquioxane, and 
polyphenylvinylsilsesquioxane. 
Such silsesquioxanes have a plurality of consecutive SiO.sub.3 R-- groups, 
forming SiO cages or "T" structures or ladders. The various rough 
geometries depend on the n in the above formula, which may vary from 2 to 
12 or greater. These silsesquioxane compounds should have at least 1 
hydroxy group, preferably at least 4. However, the greater the number of 
hydroxy groups, the greater the amount of crosslinking. A preferred 
polysilsesquioxane may be depicted as having the following structural 
formula: 
##STR6## 
In the above formula, R is a substituted or unsubstituted alkyl, alkoxy or 
pheny or combination thereof. Substituents include hydroxy, halo groups 
such as fluoro, and haloalky groups such as trifluoromethyl. As one 
example, in the above formula, R may consist of about 70 mole percent of 
phenyl and 30 mole percent propyl. Such a compound is commercially 
available as Z-6018 from Dow Corning. This compound has a Mw of 1600, 4 
SiOH groups, and an OH equivalent weight of 330-360. 
A catalyst is typically added to catalyze the crosslinking of the silane 
moieties of the silane polymer with itself and with other components of 
the composition, including the dispersed polymer. Typical of such 
catalysts are dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin 
dioxide, dibutyl tin dioctoate, tin octoate, aluminum titanate, aluminum 
chelates, zirconium chelate and the like. Tertiary amines and acids or 
combinations therof are also useful for catayzing silane bonding. 
Preferably, these catalysts are used in the amount of about 0.1 to 5.0%, 
more preferbly about 0.6% by weight of the composition. Preferably, when 
the present composition is used as a clearcoat in a basecoat/clearcoat 
system, then for improved recoat adhesion, about 0.8% of the catalyst is 
placed in the basecoat and only about 0.2% of the catalyst is placed in 
the topcoat. In such a case, the silane catalyst in the basecoat will 
diffuse to the topcoat. 
To improve weatherability of a clear finish produced by the present coating 
composition, an ultraviolet light stabilizer or a combination of 
ultraviolet light stabilizers can be added in the amount of about 0.1-5% 
by weight, based on the weight of the binder. Such stabilizers include 
ultraviolet light absorbers, screeners, quenchers, and specific hindered 
amine light stabilizers. Also, an anitoxidant can be added, in the about 
0.1-5% by weight, based on the weight of the binder. 
Typical ultraviolet light stabilizers that are useful include 
benzophenones, triazoles, triazines, benzoates, hindered amines and 
mixtures thereof. A preferred stabilizer package comprises 2% Tin 900 (UV 
screener) and 1.5% Tin 123 (hindered amine). Specific examples of 
ultraviolet stabilizers are disclosed in U.S. Pat. No. 4,591,533, the 
entire disclosure of which is incorporated herein by reference. 
For stability, sag resistance, or rheology, the composition may also 
include other conventional formulation additives such as flow control 
agents, for example, such as RESIFLOW S (polybutylacrylate), BYK 320 and 
325 (high molecular weight polyacrylates); rheology control agents, such 
as fumed or hydrophobic silica or microgel ; water scavengers such as 
tetrasilicate, trimethyl orthoformate, triethyl orthoformate and the like. 
When the present composition is used as a clearcoat (topcoat) over a 
pigmented colorcoat (basecoat) to provide a colorcoat/clearcoat finish, 
small amounts of pigment can be added to the clear coat to eliminate 
undesirable color in the finish such as yellowing. It may be preferred to 
have about a 40% level of melamine in the basecoat coupled with about 10% 
melamine in the clearcoat for improved DOI. 
The present composition also can be pigmented and used as the colorcoat, or 
as a monocoat or even as a primer or primer surfacer. The composition has 
excellent adhesion to a variety of substrates, such as previously painted 
substrates, cold rolled steel, phosphatized steel, and steel coated with 
conventional primers by electrodeposition. The present composition 
exhibits excellent adhesion to primers, for example, those that comprise 
crosslinked epoxy polyester and various epoxy resins, as well as alkyd 
resin repair primers. The present compositon can be used to coat plastic 
substrates such as polyester reinforced fiberglass, reaction 
injection-molded urethanes and partially crystalline polyamides. 
When the present coating composition is used as a basecoat, typical 
pigments that can be added to the composition include the following: 
metallic oxides such as titanium dioxide, zinc oxide, iron oxides of 
various colors, carbon black, filler pigments such as talc, china clay, 
barytes, carbonates, silicates and a wide variety of organic colored 
pigments such as quinacridones, copper phthalocyanines, perylenes, azo 
pigments, indanthrone blues, carbazoles such as carbozole violet, 
isoindolinones, isoindolones, thioindigo regs, benzimidazolinones, 
metallic flake pigments such as aluminum flake and the like. 
The pigments can be introduced into the coating composition by first 
forming a mill base or pigment dispersion with any of the aforementioned 
polymers used in the coating composition or with another compatable 
polymer or dispersant by conventional techniques, such as high speed 
mixing, sand grinding, ball milling, attritor grinding or two roll 
milling. The mill base is then blended with the other constituents used in 
the coating composition. 
Conventional solvents and diluents are used to disperse and/or dilute the 
above mentioned polymers to obtain the present coating composition. 
Typical solvents and diluents include toluene, xylene, butyl acetate, 
acetone, methyl isobutyl ketone, methyl ethyl ketone, methanol, 
isopropanol, butanol, hexane, acetone, ethylene glycol, monoethyl ether, 
VM and P naptha, mineral spirits, heptane and other aliphatic, 
cycloaliphatic, aromatic hydrocarbons, esters, ethers and ketones and the 
like. 
The coating composition can be applied by conventional techniques such as 
spraying, electrostatic spraying, dipping, brushing, flowcoating and the 
like. The preferred techniques are spraying and electrostatic spraying. 
After application, the composition is typically baked at 100-150.degree. 
C. for about 15-30 minutes to form a coating about 0.1-3.0 mils thick. 
When the composition is used as a clearcoat, it is applied over the 
colorcoat which may be dried to a tack-free state and cured or preferably 
flash dried for a short period before the clearcoat is applied. The 
colorcoat/clearcoat finish is then baked as mentioned above to provide a 
dried and cured finish. 
It is customary to apply a clear topcoat over a basecoat by means of a 
"wet-on-wet" application, i.e., the topcoat is applied to the basecoat 
without curing or completely drying the basecoat. The coated substrate is 
then heated for a predetermined time period to allow simultaneous curing 
of the base and clear coats. 
Upon curing of clear topcoat compositions of the present invention, a 
portion of the silane containing polymer may migrates and stratifies to 
the top of the clearcoat, particularly when the organosilane polymer is 
used in combination with a polyol, so as to produce a durable, 
weather-resistant clearcoat. Such stratification has been shown by 
electron scanning chemical analysis (ESCA) of a cross section of the cured 
layer of topcoat. 
The coating composition can be formulated as a one-package system that has 
an extended shelf life. 
The following Examples illustrate the invention. All parts and percentages 
are on a weight basis unless otherwise indicated. 
EXAMPLE 1 
An organosilane polymer solution A is prepared by charging the following 
constituents into a polymerization reactor equipped with a heat source and 
a reflux condensor: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
"Solvesso" 100 75.00 
Portion II 
Methacryloxypropyltrimethoxy silane 
300.00 
Styrene monomer 173.00 
Isobutyl methacrylate monomer 
103.86 
"Solvesso" 100 45.02 
Portion III 
2,2-(2-methyl butane nitrile) 
57.32 
"Solvesso" 100 85.80 
Total 840.00 
______________________________________ 
The "Solvesso" 100 is a conventional aromatic hydrocarbon solvent. Portion 
I is charged into the reactor and heated to its reflux temperature. 
Portion II, containing the monomers for the organosilane polymer, and 
Portion III, containing the polymerization initiator, are each premixed 
and then added simultaneously to the reactor while the reaction mixture is 
held at its reflux temperature. Portion II is added at a uniform rate over 
a 6 hour period and Portion II is added at a uniform rate over a 7 hour 
period. After Portion II is added, the reaction mixture is held at its 
reflux temperature for an additional hour. The resulting acrylosilane 
polymer solution is cooled at room temperature and filtered. 
The resulting acrylosilane polymer solution has a polymer solids content of 
about 70%, the polymer has a weight average molecular weight of about 
3,000, and has the following constituents: 30% styrene, 18% isobutyl 
methacrylate, and 52% methacryloxypropyl trimethoxysilane. 
EXAMPLE 2 
A hydroxy functional non-aqueous sterically stabilized dispersed polymer is 
prepared by charging the following components into a reactor: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
Isopropanol 179.26 
Acrylic polymer solution 2254.05 
(52% solids of an acrylic polymer 
of 15% styrene, 28% butyl methacrylate, 
30% butyl acrylate, 10% hydroxy ethyl 
acrylate, 2% acrylic acid and 15% ethyl 
methacrylate having a weight average 
molecular weight of 10,000 in a solvent 
mixture of 82.2% xylene and 17.8% butanol) 
Mineral spirits 255.65 
Heptane 1912.46 
Portion II 
Heptane 28.75 
t-Butyl peroctoate 4.68 
Portion III 
Methyl methacrylate monomer 
1459.69 
Hydroxyethyl acrylate monomer 
784.81 
Styrene monomer 156.97 
Portion IV 
Acrylic polymer solution 1126.52 
(53% solids of an acrylic polymer 
of 15% styrene, 28% butyl methacrylate, 
30% butyl acrylate, 10% hydroxy ethyl 
acrylate, 2% acrylic acid and 15% ethyl 
methacrylate, 2.7% glycidyl methacrylate 
having a weight average molecular weight 
of 10,000 in a solvent mixture of 82.2% 
xylene and 17.8% butanol) 
Methyl methacrylate monomer 
125.57 
Methyl acrylate monomer 565.06 
Glycidyl methacrylate monomer 
47.05 
Heptane 17.25 
Portion V 
Mineral Spirits 638.63 
t-Butyl peroctoate 47.14 
Isobutanol 127.31 
Portion VI 
t-Butyl peroctoate 30.96 
Isobutanol 255.65 
Portion VII 
Heptane 167.25 
Total 10,184.71 
______________________________________ 
Portion I is charged into the reaction vessel and heated to its reflux 
temperature. Then Portion II is added to the reaction vessel mixed and 
held at reflux temperature for 2 minutes. Then Portions III and IV are 
added simultaneously with Portion V, over a 210 minute period, to the 
reaction vessel while maintaining the resulting reaction mixture at its 
reflux temperature. Then the mixture is held at its reflux temperature for 
an additional 45 minutes. Portion VI is added over a 90 minute period 
while maintaining the reaction mixture at its reflux temperature and then 
held at this temperature for an additional 90 minutes. Portion VII is 
added and excess solvent is stripped off to give a 60% solids dispersion. 
The resulting polyester dispersed polymer has a core having a weight 
average molecular weight of about 100,000-200,000 and arms attached to the 
core having a weight average molecular weight of about 10,000-15,000. 
EXAMPLE 3 
An acrylic polyol resin solution is prepared by charging the following 
constituents into a polymerization reactor equipped with a heat source and 
a reflux condenser: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
n-Pentyl propionate 
501.00 
Portion II 
Styrene 360.00 
Isobutyl methacrylate 
696.00 
2-Ethylhexyl acrylate 
480.00 
Hydroxypropyl acrylate 
864.00 
n-Pentylpropionate 285.00 
Portion III 
t-Butyl peroctoate 60.00 
n-Pentyl propionate 
60.00 
Total 3306.00 
______________________________________ 
Portion I is charged into the reactor and is heated to its reflux 
temperature of about (160-163.degree. C.). Portions II and III are each 
premixed and then added simultaneously to the reactor while the reaction 
mixture is held at its reflux temperature. Portion II is added at a 
uniform rate over a 6 hour period and Portion III is added at a uniform 
rate over a 7 hour period. After Portion III is added, the reaction 
mixture is held at its reflux temperature for an additional hour. The 
resulting acrylic polyol resin solution is cooled at room temperature and 
filtered. 
The resulting acrylic polyol resin solution is 70% by weight of polymer 
solids. The polymer has a weight average molecular weight of about 6,000 
and a hydroxyl number of about 150-160. It consitutes the following: 15% 
styrene, 29% isobutyl methacrylate, 20% 2-ethylhexyl methacrylate, and 36% 
hydroxypropyl acrylate. 
EXAMPLE 4 
A coating composition is prepared by blending together the following 
constituents: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
Xylene 163.00 
2(3-hydroxy-3,5'-ditertamylphenyl 
113.20 
amylphenyl) benzotriazole 
Hindered amine U.V. light stabilizer 
147.80 
solution (40% solution in xylene of 
8-acetyl-3-dodecyl-7,7,9,9- 
tetramethyl-2,3,8-triazaspiro (4,5)- 
decane-2,4 dione) 
Baysilon Oil Solution 4.10 
(72.8 parts Baysilone Fluid OL and 
655.2 parts xylene) 
Portion II 
Methylated/butylated melamine 
2068.50 
formaldehyde resin (fully butylated 
and methylated melamine formaldehyde 
resin having a butoxy/methoxy ratio 
of 1:1 and a degree of polymerization 
of about 1-1.2) 
Acrylic polyol resin solution 
4054.30 
Blocked sulfonic acid solution 
236.40 
(33% solids in methanol of dodecyl benzene 
sulfonic acid blocked with dimethyl 
oxazolidine, molar ratio of acid: dimethyl 
oxazolidine is 1.52:1) 
Dispersed polymer (prepared above) 
985.40 
Acrylosilane polymer solution A 
3439.00 
(prepared above) 
Dibutyl tin dilaurate 65.00 
Portion III 
Methanol 203.80 
"Solvesso" 100 - hydrocarbon solvent 
458.50 
Total 11,939.00 
______________________________________ 
The constituents of Portion I are added in the order shown to a mixing 
vessel and agitated until solution is complete. Portion II is added to the 
vessel and mixed for 30 minutes. Portion III is added and mixed for 30 
minutes. The resulting clear coating composition has 70% solids content. 
The resulting composition is sprayed onto primer coated phosphatized steel 
panels that were coated with a solvent base pigmented acrylic polymer 
basecoating composition. The composition is sprayed onto the panels before 
the basecoating is baked. The panels are baked at 120.degree. C. for 30 
minutes and a clear coat about 2 mils thick is formed on each panel. The 
clear coating has a hardness of 8 knoops, a gloss measured at 20.degree. 
C. of 95. The coating has excellent outdoor weatherability and resistance 
to environmental attack, good mar and scratch resistance, good humidity 
resistance as determined by the Cleveland Humidity test and good chip 
resistance as determined by a gravelometer test. 
EXAMPLE 5 
An acrylosilane polymer solution B is prepared by first forming a silane 
containg macromonomer and then reacting the macromonomer with acrylic 
monomers. 
The macromonomer is prepared by charging the following constituents into a 
reactor equipped as above: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
Y-9030 (isocyanatopropylmethoxy 
750.0 
silane) 
Xylene 300.0 
Portion II 
Hydroxyethyl acrylate monomer 
340.0 
Total 1390.0 
______________________________________ 
Portion I is heated to about 120.degree. C. and Portion II is slowly added 
over a 1 hour period with constant mixing. The reaction mixture is held at 
the above temperature for about 1 hour and the isocyanate level is checked 
by infrared analysis. When the isocyanate level reaches zero, the reaction 
is stopped and the resulting macromonomer solution is cooled to room 
temperature. 
Acrylosilane polymer solution B is prepared by charging the following 
constituents into a reactor as equipped above: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
"Solvesso" 100 430.0 
Portion II 
Macromonomer solution (prepared above) 
1826.0 
Styrene monomer 765.0 
Methyl methacrylate monomer 
153.0 
Butyl methacrylate monomer 
153.0 
2-Ethylhexyl methacrylate monomer 
153.0 
"Solvesso" 100 170.0 
Portion III 
2,2-(2 methyl butane nitrile) 
100.0 
"Solvesso" 100 300.0 
Total 4050.0 
______________________________________ 
Portion I is charged into the reactor and heated to its reflux temperature. 
Portions II and III are premixed and slowly added to the reactor while 
maintaining the reaction mixture at its reflux temperature. Portion II is 
a added over a 6 hour period and Portion III is added over a 7 hour 
period. The reaction mixture is held at its reflux temperature for an 
additional hour and then cooled to room temperature. 
The resulting acrylosilane polymer solution has a polymer solids content of 
about 66%. The polymer has a weight average molecular weight of about 
6,000, and has the following constituents: 53% macromonomer, 29% styrene, 
6% methyl methacrylate, 6% butyl methacrylate, and 6% 2-ethylhexyl 
methacrylate. 
EXAMPLE 6 
An acrylosilane polymer solution C is prepared by cobalt special chain 
transfer (SCT) by charging the following constituents into a heated 
reactor flask of five liter volume fitted with a water cooled condensor, 
stirrer, 2 feed metering pumps and a thermometer: 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
"Solvesso" 100 120.0 
Ethylene Glycol Monobutyl Ether Acetate 
120.0 
Xylene 150.0 
Portion II 
gamma-methacryloxypropyltrimethoxy 
39.67 
silane 
Styrene 28.33 
Isobutyl methacrylate 45.33 
Co(DMG-BF.sub.2).sub.2 0.05 
VAZO 67 2.74 
Portion III 
gamma-methacryloxypropyltrimethoxy 
847.83 
silane 
Styrene 605.42 
Isobutyl methacrylate 968.67 
Portion IV 
VAZO 67 17.25 
"Solvesso" 100.00 
Ethylene glycol monobutyl ether acetate 
100.00 
Xylene 100.00 
Portion V 
t-Butyl Peroxyacetate 10.00 
Xylene 60.00 
______________________________________ 
Portion I, containing organic solvents, is charged into the reactor flask 
and heated under a nitrogen atmosphere to its reflux temperature. Portion 
II, containing the acrylosilane monomers and an initiator (a cobalt 
chelate of dimethylglycol and boron difluoride), is added to the refluxing 
solvent over a 10 minute period. After the 10 minute period, Portion III, 
containing additional monomers, and Portion IV, containing additional 
solvent, are each premixed and then added simultaneously to the reactor 
while the reaction mixture is held at its reflux temperature. Portion III 
is added at a uniform rate over a period of 360 minutes and Portion IV is 
added at a uniform rate over a period of 390 minutes. Then, Portion V, 
containing an initiator to kill the cobalt chain transfer, is fed over a 
20 minute period. After Portion V is added, the reaction mixture is held 
at its reflux temperature for an additional 30 minutes. The resulting 
acrylosilane polymer solution is cooled at room temperature and filtered. 
The polymer has a weight average molecular weight of about 10,000-12,000 
and constitutes 29% styrene, 30% isobutyl methacrylate and 41% 
methacryloxypropyltrimethoxy silane. 
EXAMPLE 7 
An acrylosilane polymer solution D is prepared by a group transfer process 
(GTP) as follows. To a four neck 3 liter flask, fitted with a stirrer, 
condenser, two feed pumps, thermometer and nitrogen inlet is added 950 g 
toluene, 136 g methyl methacrylate, 106 g butyl methacrylate, 118 g 
trimethoxysilylpropyl methacrylate and 46.2 g trimethoxysilylpropyl 
dimethyl ketene. The reaction mixture is cooled to 5.degree. C. and 4 ml 
of tetrabutyl ammonium m-chlorobenzoate catalyst is added over 90 minutes. 
The catalyst feed is temporarily interrupted during the reaction exotherm. 
When the exotherm subsides, the catalyst feed is resumed together with a 
monomer feed, over 40 minutes, of 220 g methyl methacrylate, 212 g butyl 
methacrylate and 237 g trimethoxysilylpropyl methacrylate . After 
completing all the addition, the reaction mixture is held for an 
additional half hour, after which 45 g methanol, for killing the ketene 
initiator, is added to the reaction mixture. The resulting polymer 
solution constitutes 35% methyl methacrylate, 31% butyl methacrylate, and 
34% methacryloxypropyl trimethoxy silane. 
EXAMPLE 8 
The following components are used in preparing an acrylosilane solution 
polymer by free radical polymerization. 
______________________________________ 
Parts by 
Weight 
______________________________________ 
Portion I 
"Solvesso" 100 726.4 g 
Portion II 
Methacryloxypropyltrimethoxy silane 
1380.3 g 
Styrene 500. g 
Methyl methacrylate monomer 
424.7 g 
2-Ethylhexyl acrylate 159.2 g 
Butyl methacrylate monomer 
159.2 g 
Hydrocarbon ("Napoleum" 145A) 
81.8 g 
Portion III 
"Lupersol" 70 70. g 
Hydrocarbon ("Napoleum" 145A) 
199.3 g 
Portion IV 
Hydrocarbon ("Napoleum" 145A) 
27.2 g 
Portion V 
Hydrocarbon ("Napoleum" 145A) 
9.1 g 
______________________________________ 
Portion I, containing organic solvent, is charged to the reaction flask and 
heated to reflux. Portion II, containing the monomers for the acrylosilane 
polymer, and Portion III, containing a t-butyl peroxyacetate initiator, 
are added simultaneously. Portion II is added over a 6 hour period, and 
Portion III is added over a 7 hour period. After Portion II is added, 
Portion IV is added immediately. After Portion III is added, Portion V is 
added immediately. Heating is continued at reflux for one additional hour 
after all the portions have been added. The reaction mixture is then 
cooled and filtered. 
EXAMPLE 9 
A dispersed (NAD) polymer A is prepared as follows. The macromonomer 
portion is prepared by a group transfer procedure. 
Macromonomer A: To a four neck 3 liter flask, is fitted a stirrer, 
condenser, two feed pumps, thermometer and nitrogen inlet. To the flask is 
added 840 g of toluene, 100.3 g 2-ethylhexyl methacrylate, 75.4 g isobutyl 
methacrylate, 16.4 g hydroxyethyl methacrylate and 38.6 g 
trimethoxysilylpropyl dimethylketene. The reaction mixture is cooled to 
5.degree. C. and the addition of 6.0 g tetrabutylammonium m-chlorobenzoate 
catalyst over 90 minutes is started. The catalyst feed is temporarily 
interrupted during the reaction exotherm. When the exotherm subsides, the 
catalyst feed is resumed together with a monomer feed over 40 minutes, 
comprising 202.1 g 2-ethylhexyl methacrylate, 136.7 g isobutyl 
methacrylate and 29.7 g hydroxyethyl methacrylate. A second monomer feed 
of 23.0 g allyl methacrylate is then added to the reactor. After 
completing all the additions, the reaction mixture is held for an 
additional 30 min., after which 3.0 g methanol is added to the reaction 
mixture. 
Macromolecular Core: A reactor is charged with 248.3 g of macromonomer A 
above and 251.94 g heptane and heated to reflux under N.sub.2. At reflux 
is added 0.41 g tert-butylperoctoate, an initiator, followed with monomer 
and initiator feeds added over 210 minutes. The monomer feed is as 
follows: 20.6 heptane, 41.58 g stryrene, 54.25 g Methyl acrylate, 138.61 g 
methyl methacrylate, 13.86 g methacryloxypropyl trimethoxysilane, 27.12 g 
acrylonitrile, 133.7 g macromonomer A. The initiator feed is as follows: 
48.38 g heptane and 4.16 g TBPO (tertiary butyl peroxide). The reaction is 
held at reflux for 45 minutes. A scavenger mix of 18.04 g heptane and 2.72 
g TBPO is then added over 90 minutes. The reaction is held at reflux for 
60 minutes and then distilled t 55% solids. 
EXAMPLE 10 
This example illustrates a dispersed or NAD Polymer B, in which the 
macromonomer is prepared by special chain transfer : 
Macromonomer B: To a reactor is added 100.92 g butyl acrylate, 100.92 g 
isobutyl methacrylate, 600.62 g 2-ethylhexyl methacrylate , 110.24 g 
hydroxyethyl methacrylate and 611.94 g toluene. The mixture is heated to 
reflux under N.sub.2. At reflux is added a mixture of 178.43 g butyl 
acrylate, 178.45 g isobutylmethacrylate, 42.93 g toluene, 1.17 g VAZO 88 
(a nitrile initiator) and 30 ppm Co(DMG-BF2)2 catalyst over 10 minutes. To 
the reactor is then fed a mixture of 190.61 g isobutylmethacrylate, 621.93 
g 2-ethylhexyl methacrylate, 120.66 g methacryloxypropyl trimethoxysilane, 
4.13 g VAZO 88 and 86.08 g toluene over a period of 240 minutes. This is 
followed with a scavenger feed of 108.01 g toluene and 2.01 g VAZO 88 for 
60 minutes. The reaction is the held at reflux for 90 minutes. Finally, 
251.21 g toluene is added. 
Macromolecular Core: To a reactor is charged 142.4 g of macromonomer B as 
prepared above and 251.94 g heptane. This is heated to reflux under 
N.sub.2. At reflux is added 0.41 g tert-butylperoctoate, followed with 
monomer and initiator feeds added over 210 minutes. The monomer feed is as 
follows: 20.6 g heptane, 41.58 g styrene, 54.25 g methyl methacrylate, 
138.61 g methyl acrylate, 13.86 g methaacryloxypropyl trimethoxysilane, 
27.12 g acrylonitrile, 76.68 g of macromonomer B. The initiator feed is as 
follows: 48.38 g heptane and 4.16 g TBPO. The reaction feed is held at 
reflux for 45 minutes and then a scavenger mix is started of 18.04 g 
heptane and 2.72 g TBPO over 90 minutes. The reaction mixture is held at 
reflux for 60 minutes and distilled to 55% solids. 
EXAMPLE 11 
This example illustrates a dispersed (NAD) Polymer C prepared by a free 
radical procedure: 
Macromonomer C: To a reactor is added 195.91 g xylene which is heated to 
reflux under N.sub.2. At reflux is added a mixture of 213.0 g 
butylmethacrylate, 221.21 g butyl acrylate, 49.54 g hydroxyethyl acrylate, 
11.6 g methyl methacrylate, and 6.0 g xylene over 240 mins. with the 
initiator feed. The initiator feed consists of 30.0 g xylene, 41.55 g 
butanol and 37.18 g TBPO and is fed to the reactor with monomer feed over 
270 mins. To the reactor is added a mix of 0.02 g butyl catechol, 0.21 g 
isopropanol, 8.8 g glycidyl methacrylate and 3.0 g xylene. A mix of 0.12 g 
dimethylethylamine and 0.5 g xylene is added to the reactor, held for 90 
mins. and cooled quickly to below 176.degree. F. 
Macromolecular core C: To a reactor is charged 142.4 g macromonomer C 
prepared as above and 251.94 g heptane. The mixture is heated to reflux 
under N.sub.2. At reflux is added 0.41 g tert-butylperoctoate, followed 
with monomer and initiator feeds added over 210 minutes. The monomer feed 
consists of the following: 20.6 g heptane, 41.58 g styrene, 68.11 g methyl 
methyl methacrylate, 138.61 g methyl acrylate, 27.12 g acrylonitrile, and 
76.68 g of macromonomer C as prepared above. The initiator feed consisted 
of the following: 48.38 g heptane and 4.16 g TBPO. The reaction is held at 
reflux for 45 minutes and then is added a scavenger mix of 18.04 g heptane 
and 2.72 g TBPO over 90 minutes. The reaction is held at reflux for 60 
minutes and then distilled to 55% solids. 
EXAMPLE 12 
This example illustrates a clearcoat composition according to the present 
invention. The following ingredients were added with mixing and a nitrogen 
blanket: 
______________________________________ 
Polymer B 320.00 gm 
NAD A 162.00 gm 
Tin 1130 7.50 gm 
Tin 440 (40% sol. in Xylene) 
7.50 gm 
"Byk" 325 0.60 gm 
Trimethyl orthoformate 1.00 gm 
"Fascat" 4020 6.00 gm 
"Solvesso" 100 35.00 gm 
______________________________________ 
In the above list, tin 1130 and tin 440 are U.V. screeners, "Byk" 325 is a 
flow agent, trimethylorthoformate is a stabilizer to prevent gelling, 
"Fascat" 4020 is a disbutyl tin dilaurate curing catalyst, and "Solvesso" 
100 is an aromatic solvent. The clearcoat composition is sprayed at a 
viscosity of 35" Fisher #2 cup. It is sprayed over clearcoat wet on wet at 
1.8-2.0 mil thickness and baked 30 min. at 265.degree. F. The clearcoat 
typically exhibits an out of oven hardness of 3-4 Knoop, a gloss of 85-95 
at 20.degree. and a DOI of 80-90. The clearcoat had excellent durability 
and crack resistance. 
The above examples of dispersed polymers illustrate the presparation of 
dispersed polymers with hydroxy functionalities in the macromonomer arms 
attached to the core. Analogous dispersed polymers may be prepared 
analogously, with epoxide, anhydride, isocyanate, silane, or amine 
functionalities in the macromonomers, respectively, by the substitution, 
as will be appreciated by those skilled in the art, of the 
hydroxy-containing monomer in the above example, with a corresponding 
amount, respectively of an epoxide-containing monomer such as glycidyl 
methacrylate, an anhydride-containing monomer such as itaconic anhydride, 
an isocyanate containing monomer such as benzene, 
1-(1-isocyanto-1-methylethyl)-3-(1-methylethenyl) a,a-Dimethyl 
meta-isopropenyl benzly isocyanate ("TMI" metal vinyl isocyanate available 
from American Cyanamid in Wayne, N.J.), a silane-containing monomer such 
as gamma-methacryloxypropyltrimethoxy silane, or an amide or 
amine-containing monomer such as methacrylamide. 
Various modifications, alterations, additions, or substitutions of the 
components of the composition and process of this invention will be 
apparent to those skilled in the art without departing from the scope and 
spirit of this invention and it should be understood that this invention 
is not unduly limited to the illustrative embodiments set forth herein.