CA1071343A - Flexible thermosetting acrylic enamels - Google Patents
Flexible thermosetting acrylic enamelsInfo
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- CA1071343A CA1071343A CA248,866A CA248866A CA1071343A CA 1071343 A CA1071343 A CA 1071343A CA 248866 A CA248866 A CA 248866A CA 1071343 A CA1071343 A CA 1071343A
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Abstract
FLEXIBLE THERMOSETTING ACRYLIC ENAMELS
ABSTRACT OF THE DISCLOSURE
A thermosetting acrylic enamel, useful for coating automobile and truck bumpers, flexible filler panels located between the bumper and the chassis, flexible fender extensions, and other energy absorbing parts, contains the following film-forming constituents:
(A) an acrylic polymer of an alkyl acrylate having 2-8 carbon atoms in the alkyl group, an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, an alkyl methacrylate having 1-18 carbon atoms in the alkyl group or mixtures of such an alkyl methacrylate and styrene, and a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(B) a polyester having a molecular weight not above 2,000, a hydroxyl number range of 50-150 and a glass transition temperature below 25°C;
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 and a dicar-boxylic acid, an anhydride thereof or mixtures of dicarboxylic acids, containing up to and including 12 carbon atoms, wherein at least 75% by weight, based on the weight of dicar-boxylic acid, is an aliphatic dicarboxylic acid; and (C) a nitrogen resin crosslinking agent.
ABSTRACT OF THE DISCLOSURE
A thermosetting acrylic enamel, useful for coating automobile and truck bumpers, flexible filler panels located between the bumper and the chassis, flexible fender extensions, and other energy absorbing parts, contains the following film-forming constituents:
(A) an acrylic polymer of an alkyl acrylate having 2-8 carbon atoms in the alkyl group, an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, an alkyl methacrylate having 1-18 carbon atoms in the alkyl group or mixtures of such an alkyl methacrylate and styrene, and a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(B) a polyester having a molecular weight not above 2,000, a hydroxyl number range of 50-150 and a glass transition temperature below 25°C;
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 and a dicar-boxylic acid, an anhydride thereof or mixtures of dicarboxylic acids, containing up to and including 12 carbon atoms, wherein at least 75% by weight, based on the weight of dicar-boxylic acid, is an aliphatic dicarboxylic acid; and (C) a nitrogen resin crosslinking agent.
Description
~Q7~L3~3 BACKGROUND OF THE_INVENTION
This ~nvention is related to coating compositions and in particular to flexible solvent based thermosetting acrylic enamels. The automobile and truck manufacturing lndustry is currently utilizing bumpers o~ a flexible material, flexible filler panels located between the bumper and the chassis, flexlble ~ender extensions, flexlble ex~erior trim parts, and other energy and impact absorblng parts to reduce ~amage in the event of a mlnor impact or a collision~
To provide the automobile or truck with a pleasing aesthetic appearance, a finish is applled to these parts.
This finish must have excellent adherence to the substrate, be durable, ~lexible, and weatherable. However, substrates coated with conventlonal enamel finishes have often shown failure, such as cracking o~ the ~inish where the ~inish was exposed to low temperaturesO The novel thermosetting acryllc enamel of this invention has excellent low temperature flexi-bility~ adhesion to primers and substratesg and gasoline " rffsi~tance.
SUMMARY OF THE IN~ENTION
Accordin~ to the present invention there ls provided a thermosetting acrylic enamel wherein the film-~orming constituents of the enamel consist essentially o~:
(A) 20-80% by weight, based on the weight o~ (A) plus (B) plus (C), of an acryl~c polymer conslstlng essentially of:
(l) 0-97~ by weight, based on the polymer, of an alkyl acrylat~ having 2-8 carbon atoms in the alkyl group; provided that ~hen thl.s monomer is not Present, there is present at least 20% of an alkyl meth-acrylate having 6-18 carbon atoms in the alkyl group, ~ 7~3~
This ~nvention is related to coating compositions and in particular to flexible solvent based thermosetting acrylic enamels. The automobile and truck manufacturing lndustry is currently utilizing bumpers o~ a flexible material, flexible filler panels located between the bumper and the chassis, flexlble ~ender extensions, flexlble ex~erior trim parts, and other energy and impact absorblng parts to reduce ~amage in the event of a mlnor impact or a collision~
To provide the automobile or truck with a pleasing aesthetic appearance, a finish is applled to these parts.
This finish must have excellent adherence to the substrate, be durable, ~lexible, and weatherable. However, substrates coated with conventlonal enamel finishes have often shown failure, such as cracking o~ the ~inish where the ~inish was exposed to low temperaturesO The novel thermosetting acryllc enamel of this invention has excellent low temperature flexi-bility~ adhesion to primers and substratesg and gasoline " rffsi~tance.
SUMMARY OF THE IN~ENTION
Accordin~ to the present invention there ls provided a thermosetting acrylic enamel wherein the film-~orming constituents of the enamel consist essentially o~:
(A) 20-80% by weight, based on the weight o~ (A) plus (B) plus (C), of an acryl~c polymer conslstlng essentially of:
(l) 0-97~ by weight, based on the polymer, of an alkyl acrylat~ having 2-8 carbon atoms in the alkyl group; provided that ~hen thl.s monomer is not Present, there is present at least 20% of an alkyl meth-acrylate having 6-18 carbon atoms in the alkyl group, ~ 7~3~
(2) 3-15~ by weight~ based on thç weight o* :
the polymer, o~ a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms ~n the alkyl group or mix~ures thereof;
(~) 0-90% by weight, based on the weight of the polymer, o~ an alkyl methacrylate -:
having 1-18 carbon atoms in the alkyl group .' or ~ixtures o~ an alkyl methacrylate ha~ing 1-18 carbon atoms in the alkyl group ~-and styrene3 wherein styrene does not exceed 75% by weight of sa~d mixture; and (4) 0-10% by weight, based on the weight o~ ,~
the polymer, o~ an a$~-e~hylenically unsaturated carboxylic acid such as .
~, acrylic acid, methacrylic acid~ itaconic acid, or mixtures thereo~;
wherein components (1) through (4) total 100~
said acrylic polymer:has an inherent ViSCQSity, at 25c~ o~ 0.05-0.~5 (determined as a 0.5%
~olution in 1,2-dichloroet~ane) and a glass , ~ransition temperature not exceeding 60C;
~,1' , (B) lQ-50~ by weight, based on the we,ight o~ (A) plus (B) plus (C)a o~ a polyester prepared from linear or branched chain diol~ including ether glycols ~r mixtures thereof or mixtures o~
, ~ .
diol~ and triols, contalning up to and including ' -~:.
8 carbon atoms and a dlcarboxylic acld, an ., -anhydride thereof or mixtures of dicarboxylic . acids~ contain~ng up to and including 12 carbon ,:
-30 atoms, wherein at least 75~ by weight, based on the w lght~o~ dicarboxylic acid, is an aliphatic ~ :' , .
~ ~ 3 ~ :
. :
7~343 dicarboxylic acid; wherein sald polyes~er ha~
a molecular we~ght not exceeding 2,000, a hydroxyl number range o~ 50-150, a maximum acid number o~ 10, and a glass tr~nsition temperature below 25~; and ~C) 10-4Q% by weight, based on the welght o~ (A) plus (B) plus (C), of a nitrogen resin cross-linking agent, wherein components (A)~ (B)~ and (C) add up to 100%~
. ~
.
DESCRIPTION OF THE INVENTION
.
The novel thermosetting acrylic enamel o~ this invention has a solids content of film-~orming constituents of about lO to 7G~ and preferably 15 to 40% by weight. Thls coat- ;
ing composltion ca~ be clear or pigmented and if pigmented can contain up to about a pigment/~inder ratio of lOO/100 and . usually 50~100. ;`~
. .
Optionally, the coating composition can contain color-ants~ wetting agents, antioxidants, fungicides, bactericides, viscosity control agents, and other conventional additives for 20 enamels.-~he film-~orming components o~ the thermosetting acrylic enamel contaln 20-80g by weight o~ an acrylic polymer~
,10-50% by weight Or a polyester, and 10-40% by weight o~ a nltrogen resin crosslinking agent, based on the weight of these - . .
I ~llm-~ormers. Preferablyg for the best balance of properties of low temperature flexibill~y, adhesion to primers and ~ æubstrate, and ~asoline resist~nce, the coating composit~on -~ contains 30-60% by weight o~ the acrylic polymer~ 2~-40~ by we~ght o~ the pol~ester, and 15-35~ by weight of the nitrogen ~i .
` 30 resin crosslinking agent. One pre~rred compositlon conta~n~
. :
: ~ ~ 4 -~: - ' . "~ :-': ;',.. :
~L~'7~3~3
the polymer, o~ a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms ~n the alkyl group or mix~ures thereof;
(~) 0-90% by weight, based on the weight of the polymer, o~ an alkyl methacrylate -:
having 1-18 carbon atoms in the alkyl group .' or ~ixtures o~ an alkyl methacrylate ha~ing 1-18 carbon atoms in the alkyl group ~-and styrene3 wherein styrene does not exceed 75% by weight of sa~d mixture; and (4) 0-10% by weight, based on the weight o~ ,~
the polymer, o~ an a$~-e~hylenically unsaturated carboxylic acid such as .
~, acrylic acid, methacrylic acid~ itaconic acid, or mixtures thereo~;
wherein components (1) through (4) total 100~
said acrylic polymer:has an inherent ViSCQSity, at 25c~ o~ 0.05-0.~5 (determined as a 0.5%
~olution in 1,2-dichloroet~ane) and a glass , ~ransition temperature not exceeding 60C;
~,1' , (B) lQ-50~ by weight, based on the we,ight o~ (A) plus (B) plus (C)a o~ a polyester prepared from linear or branched chain diol~ including ether glycols ~r mixtures thereof or mixtures o~
, ~ .
diol~ and triols, contalning up to and including ' -~:.
8 carbon atoms and a dlcarboxylic acld, an ., -anhydride thereof or mixtures of dicarboxylic . acids~ contain~ng up to and including 12 carbon ,:
-30 atoms, wherein at least 75~ by weight, based on the w lght~o~ dicarboxylic acid, is an aliphatic ~ :' , .
~ ~ 3 ~ :
. :
7~343 dicarboxylic acid; wherein sald polyes~er ha~
a molecular we~ght not exceeding 2,000, a hydroxyl number range o~ 50-150, a maximum acid number o~ 10, and a glass tr~nsition temperature below 25~; and ~C) 10-4Q% by weight, based on the welght o~ (A) plus (B) plus (C), of a nitrogen resin cross-linking agent, wherein components (A)~ (B)~ and (C) add up to 100%~
. ~
.
DESCRIPTION OF THE INVENTION
.
The novel thermosetting acrylic enamel o~ this invention has a solids content of film-~orming constituents of about lO to 7G~ and preferably 15 to 40% by weight. Thls coat- ;
ing composltion ca~ be clear or pigmented and if pigmented can contain up to about a pigment/~inder ratio of lOO/100 and . usually 50~100. ;`~
. .
Optionally, the coating composition can contain color-ants~ wetting agents, antioxidants, fungicides, bactericides, viscosity control agents, and other conventional additives for 20 enamels.-~he film-~orming components o~ the thermosetting acrylic enamel contaln 20-80g by weight o~ an acrylic polymer~
,10-50% by weight Or a polyester, and 10-40% by weight o~ a nltrogen resin crosslinking agent, based on the weight of these - . .
I ~llm-~ormers. Preferablyg for the best balance of properties of low temperature flexibill~y, adhesion to primers and ~ æubstrate, and ~asoline resist~nce, the coating composit~on -~ contains 30-60% by weight o~ the acrylic polymer~ 2~-40~ by we~ght o~ the pol~ester, and 15-35~ by weight of the nitrogen ~i .
` 30 resin crosslinking agent. One pre~rred compositlon conta~n~
. :
: ~ ~ 4 -~: - ' . "~ :-': ;',.. :
~L~'7~3~3
3 ~ by weight o~ the acrylic polymer, 4 ~ by we~ght of the polyester, and 30~ by weight o~ the nitrogen resin cross-linking agent. Another pre~erred composition is a 50/30/~0 by welght ratio o~ these three compo~ents.
The acryllc polymers utilized in the coating composi-tion are prepared by conven~ional polymerizat~on ~echniques ln which the monomers are blended with solvents and polymeriza-t~on catalysts and heated to about 60-150C for about 2-10 hour~, About 0.1 to 4% by weight, based on the weight of the monomers used to prepare the acrylic polymer, of a polymeriza-tion catalyst is used. Typical catalyst are azo-bis-iso-butyronitrile~ azo-bis-alpha,gama-dimethylvaleronitrile, .
benzoyl peroxide, t-butyl per~xypivalate~ ditertiary-butyl peroxide, and the like. Up to 5% by weight of the monomers of a chain transfer agent such a~ dodecylmercaptan or benzene-thiol can be used to c~ntrol molecular weight.
Typical solvents which can be used to prepare the acryl1c polymer and also used as diluent in the coating composi-tion used in this invention are toluene, xylene, butyl acetate, ethyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone~ ethyl alcohol, normal-butyl alcohol, other aromatic hydrocarbons, cycloaliphatic hydrocarbons~ esters, ethers, ketones~ and alcohols~ suc~ as are conventionally used.
- The acrylic polymer of the thermosetting acrylic enamel used in this invention con~ains Q-g7~ by weight, based on the pol~mer, o~ an alkyl acrylate having 2-8 carbon atoms in the alkyl gro~p, provi~ed that wh~n this monomer is not present then the polymer will conkai~ at least 2~ by weight, based on the polymer, of an alkyl methacrylake having 6-18 carbon atoms in the alkyl group. Typical alkyl acrylates which ~07~3~3 ~
can be used are ethyl acrylate, but~1 acxylate, isobutyl acrylate, and 2-ethylhexyl acrylate~ Prefe~ably the acrylic polymer contains 50-75~ by ~eiyht o~ the ~lkyl acrylate having 2-8 carbon atoms ; n the alkyl group, and most preferably butyl acrylate. Typic~l alkyl methacrylates which can be used to replace the alkyl acrylates without losing the requisite flexibility and which provide additional outdoor durability for the acrylic enamel can include hexyl methacryla~e, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, and the like.
The acrylic polymer also contain~ ~-15% by weight, based on the polymer, of a hydroxyalkyl acrylate or methacryl-ate or a mixture thereof having 2-1~ carbon atoms in the alkyl ~roup. Typical compounds o~ this type are hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate~
hydroxypropyl methacrylate, hydroxybutyl methacrylate, and the like Preferably the acrylic polymer contains from 6-12%
; by weight of the hydroxyalkyl acrylat~, preferably hydroxy-ethyl acrylate.
The acrylic polymer can also contain o-~n~ hy weight, based on the polymer, of an alkyl methacrylate having 1-18 carbon atoms in the alkyl group or a mixture of such alkyl `
methacrylate and styrene. When such mixture of monomers is usedl styrene does not exceed 75% by weight of this mixture.
Typical alkyl methacrylates which can be used in addition to those listed above are methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl meth-acrylate, isobutyl methacrylate, and the like. Preferably, the acrylic polymer contains 10-30% by weight o~ methyl meth-acrylate or a mixture o~ methyl methacr~ylate and styrene ~ 6 -' - .
`~ 7~ IL3 or, in addit:~on to methyl methacrylateJ 20-80% by weight, based on the polymer, and preferably 30-6Q% by weigh~J of alkyl methacrylate having 6-18 carbon atoms in the alkyl group ~
The acryl~c polymer contains 0-10% by weight, based on the polymer, of an ~,~ eth~lenically unsaturated carboxylic acid and pre~erably 1-5~ by weight of the acid. Typical acids are acrylic acid~ methacryllc acid~ itat,onic acld, crotonlc acid~ and the like. Rreferred are acr~lic acld and methacr~lic acid.
Th~ following is one group o~ preferred acrylic polymers: 53-75% by weight o~ butyl acrylate~ 10-30~ by weight~ :
of methyl methacrylate~ 6-12% by weight o~ hydroxyethyl acrylate, and 1-5~ b~ weight of acr~lic acid or methacrylic acid. Another group o~ preferred polymers, having excellent durability, contains 20~65% by weight of methyl methacrylate, 20-60% o~ lauryl methacrylate or stearyl methacr~late, 6-12%
by weight of 2-hydroxyethyl acrylate, and 1-5% by weight of acryl~c acid or methacrylic acid. Still another group o~
pre~erred polymers contains 10-30~ by weight of methyl methacrylate, 20-60~ b~ weight o~ alkyl methacrylate having 12-16 carbon atoms in the alkyl group, 20-40% by weight o~
alk~l acrylate havlng 2-8 carbon atoms in the alkyl group, 0-35~ by weight of normal-butyl methacrylate, 6-12% by we~ght ~ o~ 2-hydroxyethyl acrylate, and 1-5% by weight o~ acrylic : acid or methacrylic acid. One particularly pre~erred polymer that results in a high quality flexible finish contains 61~ butyl acrylate, 26% methyl methacrylate, 10% hydroxyethyl acrylate, and 3~ acrylic acid~ ~ blend of acrylic polymers that has khe final composition as lndicated above can also b~
used in the acr~lic enamel.
~ 7 ~
.~ ~ 1~ .
~ . ~ . . _ .
10~13~3 AmorAg paxticularl~ prefe~xed pol~mers resulting in a durable high ~uality flexible finish are included the following: 28~ methyl methacrylate~ 29% lauryl methacrylate, 30~ normal-butyl ~crylate, 10% 2~hydroxyethyl acrylate, and 3% acrylic acid; 26.4~ methyl methacrylate, 51% lauryl meth-acrylate, 9.6% normal-butyl methacrylate, 10% 2-hydroxye~hyl acrylate, and 3~ acrylic acid; 26.44 methyl m~thacrylate, 30% stearyl methacrylate, 30.6~ normal-butyl methacrylate, 10~ 2-hydxoxyethyl acrylate, and 3~ acrylîc acid. :
The acrylic polymer of the thermosettlng acrylic e~amel used in th~s invention has an inherent vlscosity, at 25C, of 0.05 0.~5, as determined as a 0.5% solution in 1,2-dichloroethane. The polymer has a glass transition temperature not exceeding 60~C and a hydroxyl number range of approxi-mately 15-75. The hydroxyl number is defined as the number of milligrams o~ potassium hydroxide needed to neutralize the acetic acid generated during the analysis of a 1-gram sample.
The polyester of the thermosetting acrylic enamel of this invention is prepared from linear or branched chain diols, includ~ng ether glycols, or mixtures thereof or mixtures of diols and triols, containing up to and including 8 carbon atoms an~ a dicarboxylic acid, an anhydride thereo~ or a mixture of dicarboxylic acids~containin~ up to and including 12 carbon atoms~ wherein at least 75% by weight, based on the weight of dicarboxylic ac~d, is an aliphatic dicarboxylic acid. The polyester pre~erably comprises between 20-40% o~ the film-. .
forming constituents of the thermosetting acrylic enamel.
Typical diols w~ich can be used in the preparation ofthe polyes~er include ethylene gly~ol, 1,2-propylene glycol, 1~3-propylene glycol, 1~2-butylene glycol, l~-butylene glycol~
l~-butylene glycolD neopentyl glycol~ 2~methyl-2-ethyl-1S~_ ~ ~ 7 ~ 3 4 3 ' ~ :
propanediol, 1,6-hexanediol, diethylene glycol, trlethylene glycol, 2-ethyl-1,3-hexanediol~ and the like. Pre~erably neopentyl glycol, 1~6-hexanediol or their mixtures~ are utillzed.
Typical trlols which can be used in the preparatlon o~ the polyes+~ r include tr~methylolpropane, trimethylolethane, glycerol, and 1,2~6-hexanetriol.
Typieal diearboxylie aeids inelude succinic aeid, sebacic acid, glutaric acid, adipic aeid, azelaic acid~
dodecanedioic acid, the isomeric phthalic acids~ and the like.
As is known to those skilled in the art~ anhydrides of the dicarboxylic acids can also be utilized. A preferred diacid is adipic acid.
The polyesters of the thermosettin~ acrylic enamel ~ of this invention meet two criteria: ~irst~ the polyesters ; have a glass transition temperature below 25C and preferably below O~C. As an example, a polyester prepared ~rom neopentyl glycol and adipic acid has a glass transition temperaturç of -34C. Second, in order that the polyester and the acrylic polymer of the thermosetting acrylic enamel o~ this invention b~ compatible the molecular weight o~ the polyester must not exceed approximately 2,000. Polyesters above this mole~ular weight may undergo phase separakion ~rom the acrylic polymers utilized in this invention and provide hazy films. Preferred . molecular weight is approx~mately 1,000 as calculated from hydroxyl number ~alues.
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 aeid number below 10 i8 preferable. The acid number is definod as the number o~
milligram~ o~ potassium hydroxide needed to neutralize a _ g _ .
13~3 l-gram sample of the polyester.
The nitrogen resin crossllnking agents are well-known in the art and comprise 10-40% by weight of the coating composltion of this invention. Preferably the coating compos~-tion contains 15-355~ o~ the crosslinking agent. ~hese nitrogen resins are the alkylated products o~ amino resins prepared by the condensations o~ ak least one aldehyde with at least one of urea, N,N'-ethylene urea, dicyandiamide~ and amino tri-aæ~nes such as melamines and ~uanamines. Among the aldehydes th~t are suitable are ~ormaldehyde, revertible polymers there-of such as parafo~naldehydeg acetaldehyde~ crotonaldehyde~ and acroleinO Preferred are formaldehyde and revertible polymers thereof. The amino res~ns are alkylated with 1-6 alkanol mole-cules containing 1-6 carbon atoms. Preferably the amino resins are alkylated with 3-6 alkanol molecul0s, wherein the preferred alkanols are methanol or n-butanol. Preferred nitrogen resins include melamine resins such as partially butylated melamine-formaldehyde resins or partiaily methylated melamine-formalde-hyde resins The nitrogen resins can be utilized neat or dissolved in or~anic solvents. Acceptable solvents include methanol, isopropanol, n-butanol, toluene, xylene~ hydrocarbon soivents, 2-butoxy-1-ethanol, and mixtures thereof.
During the crosslinking reaction to be described ~elow3 the nitrogen resins can crosslink with themselves or they can crossllnk with the hydroxy-functional acrylic poly-mers and the hydroxy-functional polyesters.
Optionally, an acid catalyst can be used in the coat-ing composition to facilitate curing. Useful acid catalysts 3 include the alkylated benzene sulfon~c acids such as para-:. ~ 10 - ' ~7~3~3 toluene sul~onic acid and the mono- and di- e~ters of phosphoric acid where the esterifying alcohols ~an be alkyl, cycloalkyl or aryl alcohols. Phosphoric acid itself can also be utilized. The composition can contain from 0-5~ by weight of an acid catalyst.
The acid catalyst can be utilized when, for example, there is an absence of acid groups in the acrylic polymer, ~hen a low temperature cure is required or when a highly etherified melamine resin such as hexamethoxymethylmelamine ~s used.
The thermosetting acrylic enamel of this invention can be pigmented. Typical pigments which can be used are metallic oxides, pre~erably titanium dioxide, zinc oxide, iron oxide, and the like, metallic flakes such as aluminum flake~ metallic powders, metallic hydroxides~ "Afflair'~Flake pigments (a registered trademark of E. I. du Pont de Nemours and Company), i.e. mica coated with titanium dioxide sulfatesJ carbonates, carbon black, silica~ talc, china clay, and other pigments, organic dyes~ and lakes, The amount of pigment utilized can depend on the type of ~inal application of the thermosettlng acrylic enamel. Pigment/binder ratios between 3/100 and 100/100 can be utilized with the preferred P/B range being 3/100-50/100 ~or automotive applications and near the maximum P/B rati~ of 100/100 for other industrial coatings.
The thermosetting acrylic enamel of this invention can be adhered to a substrate directly or a primer composition can be used to improve adhesion. Typical primers that can be used include polyalkylene ether glycols crosslinked with an aroma~ic diisocyanate and a polyester diol~ chain-extended - 11 ~
:
, .
~107~4~
with an organic diisocyanate, and crosslinked with an alkylated melamine-formaldehyde resin.
A variety o~ substrates can be coated with the acrylic thermosetting enamel o~ this invention; the sub- `
strates c~n be rubbery, semi-rigid, and metallic. Examples of suitable substrates are ~lexible hydrocarbon rubbers such a~
EPDM (~erpolymers o~ ethy~ene, propylene, and diene)~ butyl rubber, styrene-butadiene rubber, polybu~adiene rubber or polyisoprene rubber; urethane and Hytre ~ (registered trade-mark of E. I. du Pont de Nemours and Company) polyester rubber;
injection molded polyester urethane, elastopla~tic micro-cellular urethane ~oam; ABS (terpolymers of acrylonitrile, butadiene, and sytrene), steel; aluminum.
The thermosetting acrylic enamel of this invention can be applied by any o~ the standard application methods such as spray or roller coating and brushing. ~1hen the coating is applied by spraying it is possible to utilize spray solids higher than has been customary with most commercially useful pr~or art enamels. When a pre~erred solvent such as normal-butanol is included in the solvent system an ena~el of up to 40% solids content can be sprayed. The coating ~hickness can be from 0.03 millimeter to 0.07 millimeter, the preferred thickness being approximately 0.05 millimeter The thermosetting acrylic enamel of this invention can be cured at elevated temperatures. Typical curing condl-tions comprise heating the coating at approximately 100-110C
~or one hour or at approximately 150C for 10 minutes. The coatings are cured at approximately 120C ~or ~0 minutes prior to carrying out the various tests to be described below.
The resulting dried and cured coating is a polyblend . - , ' . "" .
.
. .... . , . ~ . , .. .. , - . . . : .
~L~7~34~
~tructure ln which the acrylic polymer surrounds partlcles o~
the soft polyester polymer and the structure is crosslinked with the nitrogen resin. The above structure is the result of the hard acrylic polymer and the soft polyester polymer having borderline compatibility. In solution the polymers are completely homogeneous but a controlled degree of phase 6eparat~0n of the soft polymer from the hard polymer oc~urs when the solvents evaporate during film formation on drying of the coating9 The crosslinkin~ agent is compatible wit~ both the hard and the so~t polymers and is distributed through both phases and forms a uniformly crosslinked structure~ As a result of this novel macroscopic compatibility and microscopic incompatibility of the acrylic pol~ner and the polyester upon fllm formation, there is obtained the thermosetting acryllc enamel of this invention.
Thls unique structure provides a coating with excel-len~ toughness, flexibility, and gasoline resistance which are required for many end uses such as coatings for flexible sub-strates, finishes for plastics~ coatings for coi~ or metals3 ~inlshes ~or foamed rubber and foamed plastics~ post-formable coatings for metals, and the like.
A number of tests can be oarrie~ out to demonstrate the ~uitability for various flnal applications of the coatings ~ased on the thermQsett~tng acrylic enamel of this invention.
The mandrel test is carried out by bending a coated sample panel around a 2, 1, and 1/2 inch mandrel, respectively, at room temperature and at -30~C. The coated specimens are examlned for delamlnation and cracking. Samples showing no signs of cracklng at the lower of the two temperatures can ~0 be utili~6d in appllcations where low temperature flexibility .
:
: . . , '. '.. ,' - , ' - - : . .
i343 is a requlrement.
The gasoline resistance of the coatings-~f this ~nvention is determined by an immersion test in which the coated panels are immersed into gasoline 10 tlmes, for 10 seconds each3 with a 20-second interval between each of the immersion~. Samples are then examined ~or softening of the coating by scraping it with the rounded end o~ a paper clip and for color removal by wiping over the surface of the coat-in~ with folded cheese-cloth.
Additional tests, designed to prov~de information on long term stability of the coatings, can be carried out by soakin~ the samples in ~Jater at between 30-35C for 10 days.
At the end of this period the panels are checked ~or blister-ing and are tested for loss of adhesion by peeling a piece of scotch ~ape ~rom an X mark placed on the coating prior to the soaking cycle, Additional testing~ in a weatherometer ~or exposUre resistance and for gloss retention~ can also be carried out.
The following ex~nples illustrate the inventîon.
All quanti~ies are on a weight basis unless otherwise indicated.
EXAMPIE~
A
Polymer solution A is prepared as follows:
Parts By Portion 1 Weight .... ..
Methyl methacrylate 16~10 Butyl acrylate 68.o3 2-Hydroxyethyl acrylate 6~10 ~ Acrylic acid 1.5~
n-Butanol 142~74 .
, , :'.
, ~ .~ . . .
~7~1L3~3 ' ;~
Parts By Portion 2 W~ight -Butyl acetate 9.1~
Benzoyl peroxide 0.054 (Containing 22~ water) Port Methyl methacrylate 102.40 Butyl acrylate 204.00 2-Hydroxyethyl acrylate 38~80 Acrylic acid 11.90 ~enzoyl peroxide 1.132 (Conkaining 22% water) Portion 4 -Butyl acetate ~1.60 Be~zoyl peroxide o/324 (Containing 22~o water) Portion 5 n-~utanol 174O10 807.96 :
Portlon 1 is charged into a reaction vessel equipped with a stirrer, a pressure equalizer addition funnel, con-denser, a ther~ometer, and a heating mantle and heated to lts re~lux temperature o~ about 120C Portion 2 is added in about one minute to initlate polymerization5 followed by the addition of portion ~ at a uniform rate. This addition is complete in 90 minukes. Portion 4 is then added over a 60-minuke period~ at a un~form rate, while a sllght reflux is maintained~ After a further 15-minute period portion 5 is added.
The resulting polymer solukion has a polymer solids .
... . .
~7~3~3 content of about 55% by weighk indicating that monomer con-verslon is substantlally complete. The polymer has the composition: methyl methacrylate/butyl acrylate/2-hydroxy-ethyl acrylate/acrylic acid in a welght ratio of 26/61/10/~, and has an inherent viscosity~ at 25C, o~ 0.20, measured as a 0,5% solution ~n 1,2-di~hl~roethane, and has an acid number of 24.
(B) Polymer solution B ls prepared as follo~s:
Parts By Portion 1 Weight .
Aromatic hydrocarbon mi~ture ~boiling point range: 150-190C) 145.6 Xylene 156.6 n-Butanol 21.9 Portion 2 Styrene 242.9 - Butyl acrylate 18~.5 2-~Iydroxyethyl acrylate 39.6 Acrylic acid 18.7 Dltertiarybutyl peroxide 9,7 t_Butyl peracetate (75% in mineral spirits) 6.5 , . . .
Portion 1 is charged into a reaction vessel equipped as above, and heated to its reflux temperature of about 134C~
Por~ion 2 is added over a 2-hour period while the reaction mixture is maintained at a slight reflux (134-137C) and for an additional 1.5 hours. Conversion of the monomers is sub- .:
ætantlally compl~te at this timer The polymer has a composit,ion . : :
~07~3~3 butyl acrylate/styrene/2-hydroxyethyl acrylate/acrylic acid//38/50/8/4 (by weight), a æolids content of 60% by welght, and a Gardner-Holdt Yiscosity~ at 25C~ of X-Z.
(C) A mill base is prepared as ~ollows:
Part~ By Portion 1 Weight Polymer solution B (prepared above) 9~00 Toluene 4.50 Anhydrous isopropanol 3.60 V.M. ~ P. naphtha ~.90 Portion 2 T~tanium dioxide pigment 63.oo Portion 3 . .
Polymer solution B (prepared above) 16.00 Total100.00 Portion 1 is charged into a high-speed mixer and mixed for 30 minutes and then portion 2 is added and mixed ~or :
an additional hour. Portion 3 is.then added and mixed for 1 hour. The resulting composition is then passed through a conventional sand mill and ground at 20 gallons per minute in an 8 gallon unit to fo~m a white pigment dispersion having a pigment to binder ratio o~ 413/100.
~ ' .'' :
'' :
.' '' ':
- ~
~107~L34L3 ~ ~
: (D) A coatlng composition is prepared by blending together the following ingredients:
Parts ~y White mill base ~Prepared in (C) above) 66.7 Polymer solution A (Prepared above) 36~4 Polyester(l) 40~o Butylated Melamine/Formaldehyde Resi~ ~
~ 10(55.5% solids) 54.1 - n-Butanol 108.0 : ., ~1) The polyester is prepared ~rom adipic acid and neopentyl glycol, has a hydroxyl number o~ 90 and an acid number of 0,4, .
(2) The nitrogen resin i5 dissolved in n~butanol and . has a Gardner-Holdt viscosity, at 25C, of I-0.
.
; The resulting coating composition has a solids con-tent of 45% by weight and a pigment/binder ratio o~ 42/100. The compozition is applied to a thermoplastic urethane rubber sub-strate with a fixed-gap (10 mil) coating kni~e and cured ~or 30 minutes at 125Co The resulting cured coating has excellent low tamperature flexibility and satis~actory gasoline resistance. ;.
. EXAMPLE 2 .
me coating composition of Example 1 is applied to a steel sheet having a thicl~ness use~ul in automobile construc-tion (35 mil)~ Curing as above results in a film having a 1-5 ~:
~HN hardness and passing a zero T-hend test.
.
~, ' : - 18 -,, .
' : ~
7 ~ 3 A coating compositlon is prepared as follows:
P~rts By Portion 1 Weight .
Polymer solution A rom Ex. l(A17 54.5 Polyester (shown in E~ample 1)40.0 Butylated Melamine/Formaldehyde Resin (55~ solids, as described in ~xample l~ 5400 ~ 10 Portlon 2 : Aluminum (medium-coarse ~lakes in paste ~orm, at 65-66% solids in a blend o~ mineral spirits and high solvency naphtha) 6.o Portion 3 n-Butanol 140.0 Portion 4 Ethyl acetate/cellosolve acetate ` (2/l by weight) lO0.0 Portion l is blended at room temperature. To the blend is added portion 2 and mixed for ~0 minutes at approxi-mately 500 revolutions per minute. The composition is thinned to 35% ~by weight) solids content by the addition of portion 3.
The composition can be applied at this solids content or can be further thinned, by the addition o~ portion 4~ ~or spray-~application by an air suction spray-gun The composition is sprayed onto a 0.25-inch thick iiNordell' ~trademark of E~ I.
du Pont de Nemours and Company) rubber substrate whlch is a rubber of an ethylene-propylene-diene polymer and baked for ~0 minutes at 125C to give a finish about 1.8 mils in ; thickness.
.. ., .. . . . -, lL~7~3~3 Be:~ore the rubber is coated with the compostion, it is surface treated using the îollowing procedure:
( 1) T~e rubber substrate is immersed inko a cleaning solution of 1.5~ (b~r weight) RIDOLINE* 72, manu-factured by Amchem Products J Incorporated, Ambler, Pa~;
(2) me substrate is rinsed as follows:
r~ree 15 second rinses with the last rinse being with deionized water;
10 (3) m e substrate is drained and dried;
The acryllc polymers utilized in the coating composi-tion are prepared by conven~ional polymerizat~on ~echniques ln which the monomers are blended with solvents and polymeriza-t~on catalysts and heated to about 60-150C for about 2-10 hour~, About 0.1 to 4% by weight, based on the weight of the monomers used to prepare the acrylic polymer, of a polymeriza-tion catalyst is used. Typical catalyst are azo-bis-iso-butyronitrile~ azo-bis-alpha,gama-dimethylvaleronitrile, .
benzoyl peroxide, t-butyl per~xypivalate~ ditertiary-butyl peroxide, and the like. Up to 5% by weight of the monomers of a chain transfer agent such a~ dodecylmercaptan or benzene-thiol can be used to c~ntrol molecular weight.
Typical solvents which can be used to prepare the acryl1c polymer and also used as diluent in the coating composi-tion used in this invention are toluene, xylene, butyl acetate, ethyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone~ ethyl alcohol, normal-butyl alcohol, other aromatic hydrocarbons, cycloaliphatic hydrocarbons~ esters, ethers, ketones~ and alcohols~ suc~ as are conventionally used.
- The acrylic polymer of the thermosetting acrylic enamel used in this invention con~ains Q-g7~ by weight, based on the pol~mer, o~ an alkyl acrylate having 2-8 carbon atoms in the alkyl gro~p, provi~ed that wh~n this monomer is not present then the polymer will conkai~ at least 2~ by weight, based on the polymer, of an alkyl methacrylake having 6-18 carbon atoms in the alkyl group. Typical alkyl acrylates which ~07~3~3 ~
can be used are ethyl acrylate, but~1 acxylate, isobutyl acrylate, and 2-ethylhexyl acrylate~ Prefe~ably the acrylic polymer contains 50-75~ by ~eiyht o~ the ~lkyl acrylate having 2-8 carbon atoms ; n the alkyl group, and most preferably butyl acrylate. Typic~l alkyl methacrylates which can be used to replace the alkyl acrylates without losing the requisite flexibility and which provide additional outdoor durability for the acrylic enamel can include hexyl methacryla~e, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, and the like.
The acrylic polymer also contain~ ~-15% by weight, based on the polymer, of a hydroxyalkyl acrylate or methacryl-ate or a mixture thereof having 2-1~ carbon atoms in the alkyl ~roup. Typical compounds o~ this type are hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate~
hydroxypropyl methacrylate, hydroxybutyl methacrylate, and the like Preferably the acrylic polymer contains from 6-12%
; by weight of the hydroxyalkyl acrylat~, preferably hydroxy-ethyl acrylate.
The acrylic polymer can also contain o-~n~ hy weight, based on the polymer, of an alkyl methacrylate having 1-18 carbon atoms in the alkyl group or a mixture of such alkyl `
methacrylate and styrene. When such mixture of monomers is usedl styrene does not exceed 75% by weight of this mixture.
Typical alkyl methacrylates which can be used in addition to those listed above are methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl meth-acrylate, isobutyl methacrylate, and the like. Preferably, the acrylic polymer contains 10-30% by weight o~ methyl meth-acrylate or a mixture o~ methyl methacr~ylate and styrene ~ 6 -' - .
`~ 7~ IL3 or, in addit:~on to methyl methacrylateJ 20-80% by weight, based on the polymer, and preferably 30-6Q% by weigh~J of alkyl methacrylate having 6-18 carbon atoms in the alkyl group ~
The acryl~c polymer contains 0-10% by weight, based on the polymer, of an ~,~ eth~lenically unsaturated carboxylic acid and pre~erably 1-5~ by weight of the acid. Typical acids are acrylic acid~ methacryllc acid~ itat,onic acld, crotonlc acid~ and the like. Rreferred are acr~lic acld and methacr~lic acid.
Th~ following is one group o~ preferred acrylic polymers: 53-75% by weight o~ butyl acrylate~ 10-30~ by weight~ :
of methyl methacrylate~ 6-12% by weight o~ hydroxyethyl acrylate, and 1-5~ b~ weight of acr~lic acid or methacrylic acid. Another group o~ preferred polymers, having excellent durability, contains 20~65% by weight of methyl methacrylate, 20-60% o~ lauryl methacrylate or stearyl methacr~late, 6-12%
by weight of 2-hydroxyethyl acrylate, and 1-5% by weight of acryl~c acid or methacrylic acid. Still another group o~
pre~erred polymers contains 10-30~ by weight of methyl methacrylate, 20-60~ b~ weight o~ alkyl methacrylate having 12-16 carbon atoms in the alkyl group, 20-40% by weight o~
alk~l acrylate havlng 2-8 carbon atoms in the alkyl group, 0-35~ by weight of normal-butyl methacrylate, 6-12% by we~ght ~ o~ 2-hydroxyethyl acrylate, and 1-5% by weight o~ acrylic : acid or methacrylic acid. One particularly pre~erred polymer that results in a high quality flexible finish contains 61~ butyl acrylate, 26% methyl methacrylate, 10% hydroxyethyl acrylate, and 3~ acrylic acid~ ~ blend of acrylic polymers that has khe final composition as lndicated above can also b~
used in the acr~lic enamel.
~ 7 ~
.~ ~ 1~ .
~ . ~ . . _ .
10~13~3 AmorAg paxticularl~ prefe~xed pol~mers resulting in a durable high ~uality flexible finish are included the following: 28~ methyl methacrylate~ 29% lauryl methacrylate, 30~ normal-butyl ~crylate, 10% 2~hydroxyethyl acrylate, and 3% acrylic acid; 26.4~ methyl methacrylate, 51% lauryl meth-acrylate, 9.6% normal-butyl methacrylate, 10% 2-hydroxye~hyl acrylate, and 3~ acrylic acid; 26.44 methyl m~thacrylate, 30% stearyl methacrylate, 30.6~ normal-butyl methacrylate, 10~ 2-hydxoxyethyl acrylate, and 3~ acrylîc acid. :
The acrylic polymer of the thermosettlng acrylic e~amel used in th~s invention has an inherent vlscosity, at 25C, of 0.05 0.~5, as determined as a 0.5% solution in 1,2-dichloroethane. The polymer has a glass transition temperature not exceeding 60~C and a hydroxyl number range of approxi-mately 15-75. The hydroxyl number is defined as the number of milligrams o~ potassium hydroxide needed to neutralize the acetic acid generated during the analysis of a 1-gram sample.
The polyester of the thermosetting acrylic enamel of this invention is prepared from linear or branched chain diols, includ~ng ether glycols, or mixtures thereof or mixtures of diols and triols, containing up to and including 8 carbon atoms an~ a dicarboxylic acid, an anhydride thereo~ or a mixture of dicarboxylic acids~containin~ up to and including 12 carbon atoms~ wherein at least 75% by weight, based on the weight of dicarboxylic ac~d, is an aliphatic dicarboxylic acid. The polyester pre~erably comprises between 20-40% o~ the film-. .
forming constituents of the thermosetting acrylic enamel.
Typical diols w~ich can be used in the preparation ofthe polyes~er include ethylene gly~ol, 1,2-propylene glycol, 1~3-propylene glycol, 1~2-butylene glycol, l~-butylene glycol~
l~-butylene glycolD neopentyl glycol~ 2~methyl-2-ethyl-1S~_ ~ ~ 7 ~ 3 4 3 ' ~ :
propanediol, 1,6-hexanediol, diethylene glycol, trlethylene glycol, 2-ethyl-1,3-hexanediol~ and the like. Pre~erably neopentyl glycol, 1~6-hexanediol or their mixtures~ are utillzed.
Typical trlols which can be used in the preparatlon o~ the polyes+~ r include tr~methylolpropane, trimethylolethane, glycerol, and 1,2~6-hexanetriol.
Typieal diearboxylie aeids inelude succinic aeid, sebacic acid, glutaric acid, adipic aeid, azelaic acid~
dodecanedioic acid, the isomeric phthalic acids~ and the like.
As is known to those skilled in the art~ anhydrides of the dicarboxylic acids can also be utilized. A preferred diacid is adipic acid.
The polyesters of the thermosettin~ acrylic enamel ~ of this invention meet two criteria: ~irst~ the polyesters ; have a glass transition temperature below 25C and preferably below O~C. As an example, a polyester prepared ~rom neopentyl glycol and adipic acid has a glass transition temperaturç of -34C. Second, in order that the polyester and the acrylic polymer of the thermosetting acrylic enamel o~ this invention b~ compatible the molecular weight o~ the polyester must not exceed approximately 2,000. Polyesters above this mole~ular weight may undergo phase separakion ~rom the acrylic polymers utilized in this invention and provide hazy films. Preferred . molecular weight is approx~mately 1,000 as calculated from hydroxyl number ~alues.
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 aeid number below 10 i8 preferable. The acid number is definod as the number o~
milligram~ o~ potassium hydroxide needed to neutralize a _ g _ .
13~3 l-gram sample of the polyester.
The nitrogen resin crossllnking agents are well-known in the art and comprise 10-40% by weight of the coating composltion of this invention. Preferably the coating compos~-tion contains 15-355~ o~ the crosslinking agent. ~hese nitrogen resins are the alkylated products o~ amino resins prepared by the condensations o~ ak least one aldehyde with at least one of urea, N,N'-ethylene urea, dicyandiamide~ and amino tri-aæ~nes such as melamines and ~uanamines. Among the aldehydes th~t are suitable are ~ormaldehyde, revertible polymers there-of such as parafo~naldehydeg acetaldehyde~ crotonaldehyde~ and acroleinO Preferred are formaldehyde and revertible polymers thereof. The amino res~ns are alkylated with 1-6 alkanol mole-cules containing 1-6 carbon atoms. Preferably the amino resins are alkylated with 3-6 alkanol molecul0s, wherein the preferred alkanols are methanol or n-butanol. Preferred nitrogen resins include melamine resins such as partially butylated melamine-formaldehyde resins or partiaily methylated melamine-formalde-hyde resins The nitrogen resins can be utilized neat or dissolved in or~anic solvents. Acceptable solvents include methanol, isopropanol, n-butanol, toluene, xylene~ hydrocarbon soivents, 2-butoxy-1-ethanol, and mixtures thereof.
During the crosslinking reaction to be described ~elow3 the nitrogen resins can crosslink with themselves or they can crossllnk with the hydroxy-functional acrylic poly-mers and the hydroxy-functional polyesters.
Optionally, an acid catalyst can be used in the coat-ing composition to facilitate curing. Useful acid catalysts 3 include the alkylated benzene sulfon~c acids such as para-:. ~ 10 - ' ~7~3~3 toluene sul~onic acid and the mono- and di- e~ters of phosphoric acid where the esterifying alcohols ~an be alkyl, cycloalkyl or aryl alcohols. Phosphoric acid itself can also be utilized. The composition can contain from 0-5~ by weight of an acid catalyst.
The acid catalyst can be utilized when, for example, there is an absence of acid groups in the acrylic polymer, ~hen a low temperature cure is required or when a highly etherified melamine resin such as hexamethoxymethylmelamine ~s used.
The thermosetting acrylic enamel of this invention can be pigmented. Typical pigments which can be used are metallic oxides, pre~erably titanium dioxide, zinc oxide, iron oxide, and the like, metallic flakes such as aluminum flake~ metallic powders, metallic hydroxides~ "Afflair'~Flake pigments (a registered trademark of E. I. du Pont de Nemours and Company), i.e. mica coated with titanium dioxide sulfatesJ carbonates, carbon black, silica~ talc, china clay, and other pigments, organic dyes~ and lakes, The amount of pigment utilized can depend on the type of ~inal application of the thermosettlng acrylic enamel. Pigment/binder ratios between 3/100 and 100/100 can be utilized with the preferred P/B range being 3/100-50/100 ~or automotive applications and near the maximum P/B rati~ of 100/100 for other industrial coatings.
The thermosetting acrylic enamel of this invention can be adhered to a substrate directly or a primer composition can be used to improve adhesion. Typical primers that can be used include polyalkylene ether glycols crosslinked with an aroma~ic diisocyanate and a polyester diol~ chain-extended - 11 ~
:
, .
~107~4~
with an organic diisocyanate, and crosslinked with an alkylated melamine-formaldehyde resin.
A variety o~ substrates can be coated with the acrylic thermosetting enamel o~ this invention; the sub- `
strates c~n be rubbery, semi-rigid, and metallic. Examples of suitable substrates are ~lexible hydrocarbon rubbers such a~
EPDM (~erpolymers o~ ethy~ene, propylene, and diene)~ butyl rubber, styrene-butadiene rubber, polybu~adiene rubber or polyisoprene rubber; urethane and Hytre ~ (registered trade-mark of E. I. du Pont de Nemours and Company) polyester rubber;
injection molded polyester urethane, elastopla~tic micro-cellular urethane ~oam; ABS (terpolymers of acrylonitrile, butadiene, and sytrene), steel; aluminum.
The thermosetting acrylic enamel of this invention can be applied by any o~ the standard application methods such as spray or roller coating and brushing. ~1hen the coating is applied by spraying it is possible to utilize spray solids higher than has been customary with most commercially useful pr~or art enamels. When a pre~erred solvent such as normal-butanol is included in the solvent system an ena~el of up to 40% solids content can be sprayed. The coating ~hickness can be from 0.03 millimeter to 0.07 millimeter, the preferred thickness being approximately 0.05 millimeter The thermosetting acrylic enamel of this invention can be cured at elevated temperatures. Typical curing condl-tions comprise heating the coating at approximately 100-110C
~or one hour or at approximately 150C for 10 minutes. The coatings are cured at approximately 120C ~or ~0 minutes prior to carrying out the various tests to be described below.
The resulting dried and cured coating is a polyblend . - , ' . "" .
.
. .... . , . ~ . , .. .. , - . . . : .
~L~7~34~
~tructure ln which the acrylic polymer surrounds partlcles o~
the soft polyester polymer and the structure is crosslinked with the nitrogen resin. The above structure is the result of the hard acrylic polymer and the soft polyester polymer having borderline compatibility. In solution the polymers are completely homogeneous but a controlled degree of phase 6eparat~0n of the soft polymer from the hard polymer oc~urs when the solvents evaporate during film formation on drying of the coating9 The crosslinkin~ agent is compatible wit~ both the hard and the so~t polymers and is distributed through both phases and forms a uniformly crosslinked structure~ As a result of this novel macroscopic compatibility and microscopic incompatibility of the acrylic pol~ner and the polyester upon fllm formation, there is obtained the thermosetting acryllc enamel of this invention.
Thls unique structure provides a coating with excel-len~ toughness, flexibility, and gasoline resistance which are required for many end uses such as coatings for flexible sub-strates, finishes for plastics~ coatings for coi~ or metals3 ~inlshes ~or foamed rubber and foamed plastics~ post-formable coatings for metals, and the like.
A number of tests can be oarrie~ out to demonstrate the ~uitability for various flnal applications of the coatings ~ased on the thermQsett~tng acrylic enamel of this invention.
The mandrel test is carried out by bending a coated sample panel around a 2, 1, and 1/2 inch mandrel, respectively, at room temperature and at -30~C. The coated specimens are examlned for delamlnation and cracking. Samples showing no signs of cracklng at the lower of the two temperatures can ~0 be utili~6d in appllcations where low temperature flexibility .
:
: . . , '. '.. ,' - , ' - - : . .
i343 is a requlrement.
The gasoline resistance of the coatings-~f this ~nvention is determined by an immersion test in which the coated panels are immersed into gasoline 10 tlmes, for 10 seconds each3 with a 20-second interval between each of the immersion~. Samples are then examined ~or softening of the coating by scraping it with the rounded end o~ a paper clip and for color removal by wiping over the surface of the coat-in~ with folded cheese-cloth.
Additional tests, designed to prov~de information on long term stability of the coatings, can be carried out by soakin~ the samples in ~Jater at between 30-35C for 10 days.
At the end of this period the panels are checked ~or blister-ing and are tested for loss of adhesion by peeling a piece of scotch ~ape ~rom an X mark placed on the coating prior to the soaking cycle, Additional testing~ in a weatherometer ~or exposUre resistance and for gloss retention~ can also be carried out.
The following ex~nples illustrate the inventîon.
All quanti~ies are on a weight basis unless otherwise indicated.
EXAMPIE~
A
Polymer solution A is prepared as follows:
Parts By Portion 1 Weight .... ..
Methyl methacrylate 16~10 Butyl acrylate 68.o3 2-Hydroxyethyl acrylate 6~10 ~ Acrylic acid 1.5~
n-Butanol 142~74 .
, , :'.
, ~ .~ . . .
~7~1L3~3 ' ;~
Parts By Portion 2 W~ight -Butyl acetate 9.1~
Benzoyl peroxide 0.054 (Containing 22~ water) Port Methyl methacrylate 102.40 Butyl acrylate 204.00 2-Hydroxyethyl acrylate 38~80 Acrylic acid 11.90 ~enzoyl peroxide 1.132 (Conkaining 22% water) Portion 4 -Butyl acetate ~1.60 Be~zoyl peroxide o/324 (Containing 22~o water) Portion 5 n-~utanol 174O10 807.96 :
Portlon 1 is charged into a reaction vessel equipped with a stirrer, a pressure equalizer addition funnel, con-denser, a ther~ometer, and a heating mantle and heated to lts re~lux temperature o~ about 120C Portion 2 is added in about one minute to initlate polymerization5 followed by the addition of portion ~ at a uniform rate. This addition is complete in 90 minukes. Portion 4 is then added over a 60-minuke period~ at a un~form rate, while a sllght reflux is maintained~ After a further 15-minute period portion 5 is added.
The resulting polymer solukion has a polymer solids .
... . .
~7~3~3 content of about 55% by weighk indicating that monomer con-verslon is substantlally complete. The polymer has the composition: methyl methacrylate/butyl acrylate/2-hydroxy-ethyl acrylate/acrylic acid in a welght ratio of 26/61/10/~, and has an inherent viscosity~ at 25C, o~ 0.20, measured as a 0,5% solution ~n 1,2-di~hl~roethane, and has an acid number of 24.
(B) Polymer solution B ls prepared as follo~s:
Parts By Portion 1 Weight .
Aromatic hydrocarbon mi~ture ~boiling point range: 150-190C) 145.6 Xylene 156.6 n-Butanol 21.9 Portion 2 Styrene 242.9 - Butyl acrylate 18~.5 2-~Iydroxyethyl acrylate 39.6 Acrylic acid 18.7 Dltertiarybutyl peroxide 9,7 t_Butyl peracetate (75% in mineral spirits) 6.5 , . . .
Portion 1 is charged into a reaction vessel equipped as above, and heated to its reflux temperature of about 134C~
Por~ion 2 is added over a 2-hour period while the reaction mixture is maintained at a slight reflux (134-137C) and for an additional 1.5 hours. Conversion of the monomers is sub- .:
ætantlally compl~te at this timer The polymer has a composit,ion . : :
~07~3~3 butyl acrylate/styrene/2-hydroxyethyl acrylate/acrylic acid//38/50/8/4 (by weight), a æolids content of 60% by welght, and a Gardner-Holdt Yiscosity~ at 25C~ of X-Z.
(C) A mill base is prepared as ~ollows:
Part~ By Portion 1 Weight Polymer solution B (prepared above) 9~00 Toluene 4.50 Anhydrous isopropanol 3.60 V.M. ~ P. naphtha ~.90 Portion 2 T~tanium dioxide pigment 63.oo Portion 3 . .
Polymer solution B (prepared above) 16.00 Total100.00 Portion 1 is charged into a high-speed mixer and mixed for 30 minutes and then portion 2 is added and mixed ~or :
an additional hour. Portion 3 is.then added and mixed for 1 hour. The resulting composition is then passed through a conventional sand mill and ground at 20 gallons per minute in an 8 gallon unit to fo~m a white pigment dispersion having a pigment to binder ratio o~ 413/100.
~ ' .'' :
'' :
.' '' ':
- ~
~107~L34L3 ~ ~
: (D) A coatlng composition is prepared by blending together the following ingredients:
Parts ~y White mill base ~Prepared in (C) above) 66.7 Polymer solution A (Prepared above) 36~4 Polyester(l) 40~o Butylated Melamine/Formaldehyde Resi~ ~
~ 10(55.5% solids) 54.1 - n-Butanol 108.0 : ., ~1) The polyester is prepared ~rom adipic acid and neopentyl glycol, has a hydroxyl number o~ 90 and an acid number of 0,4, .
(2) The nitrogen resin i5 dissolved in n~butanol and . has a Gardner-Holdt viscosity, at 25C, of I-0.
.
; The resulting coating composition has a solids con-tent of 45% by weight and a pigment/binder ratio o~ 42/100. The compozition is applied to a thermoplastic urethane rubber sub-strate with a fixed-gap (10 mil) coating kni~e and cured ~or 30 minutes at 125Co The resulting cured coating has excellent low tamperature flexibility and satis~actory gasoline resistance. ;.
. EXAMPLE 2 .
me coating composition of Example 1 is applied to a steel sheet having a thicl~ness use~ul in automobile construc-tion (35 mil)~ Curing as above results in a film having a 1-5 ~:
~HN hardness and passing a zero T-hend test.
.
~, ' : - 18 -,, .
' : ~
7 ~ 3 A coating compositlon is prepared as follows:
P~rts By Portion 1 Weight .
Polymer solution A rom Ex. l(A17 54.5 Polyester (shown in E~ample 1)40.0 Butylated Melamine/Formaldehyde Resin (55~ solids, as described in ~xample l~ 5400 ~ 10 Portlon 2 : Aluminum (medium-coarse ~lakes in paste ~orm, at 65-66% solids in a blend o~ mineral spirits and high solvency naphtha) 6.o Portion 3 n-Butanol 140.0 Portion 4 Ethyl acetate/cellosolve acetate ` (2/l by weight) lO0.0 Portion l is blended at room temperature. To the blend is added portion 2 and mixed for ~0 minutes at approxi-mately 500 revolutions per minute. The composition is thinned to 35% ~by weight) solids content by the addition of portion 3.
The composition can be applied at this solids content or can be further thinned, by the addition o~ portion 4~ ~or spray-~application by an air suction spray-gun The composition is sprayed onto a 0.25-inch thick iiNordell' ~trademark of E~ I.
du Pont de Nemours and Company) rubber substrate whlch is a rubber of an ethylene-propylene-diene polymer and baked for ~0 minutes at 125C to give a finish about 1.8 mils in ; thickness.
.. ., .. . . . -, lL~7~3~3 Be:~ore the rubber is coated with the compostion, it is surface treated using the îollowing procedure:
( 1) T~e rubber substrate is immersed inko a cleaning solution of 1.5~ (b~r weight) RIDOLINE* 72, manu-factured by Amchem Products J Incorporated, Ambler, Pa~;
(2) me substrate is rinsed as follows:
r~ree 15 second rinses with the last rinse being with deionized water;
10 (3) m e substrate is drained and dried;
(4) The dried substrate is sprayed with a 10% solution .-o~ benzophenone dissolved in xylene to deposik about 1.0-2.0 milligrams o~ dr~ benzophenone p~r square : lnch of surface of the substrate;
(5~ The benzophenone coated surface is exposed to a ~:~
quartz-~acketed mercury vapor cont,~ining 0.05-0.4 ~oules/square centimeter of radiation in the wave length band of 365 ~ 5nm and allowed to cool to abQut 50C.
rrhe rubber substrat.e with the activated surface then is ~prayed with the above compostion and baked as indicated above. A uniform silver-gray metallic finish, having excellent gloss, Fesults.
* denotes trade mark ~. ~
~....................................................................... . :.
~Ot~1~43 .................. ,, ~.
A c~ating composition is prepared as follows:
Parts By Portion 1 White mill base (prepared in Ex.l) 66.7 Polymer solution A rrepared in Example 1 (A~7 72~7 Polyester ~o.o Par~ially Methy~ated Melamine/
Formaldehyde Resin (80% solids in iso-propanol) 25.0 Portion 2 Mono- and di-phenyl phosphate (20~ solids in n-butanol) 2.5 Portion 3 .
n-Butanol 110.0 (1~ The polyester is prepared from adipic acld, neopentyl glycol, and 1,6-hexanediol, ha.s a molecular weight of approximately 1,000, a hydroxyl number of 100, and an acid number of 0.5.
Por~ion 1 is blended at room temperature~ The acid catalyst (portion 2) is added and the blend thinned with portion ~0 The resulting composition has a solids content o.f 45~ by weight and a pigment/binder ratio of 42/100~ When cast on a steel sheet and cured for 30 minutes at 125C a uniform white glossy coating results.
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~.(171 343 EX~PLE 5 (A?
Polymer solution A is prepared as ~ollows:
Portion 1 Par~s By ` '~
Methyl methacrylate 16.1 n-Butyl acrylate 34.0 Lauryl methacrylate 34.0 2-~ydroxyethyl acrylate 6.1 Acrylic acid 1.5 n Butanol 142.7 Portion 2 Butyl acetate 9.1 Ben~oyl peroxide 0.054 (containing 22~ water) Portion 3 .
I Methyl methacrylate 102.4 : ~-Butyl acrylate 102.0 Lauryl methacrylate 102.0 2-Hydroxyethyl acrylate . 38.0 ~0 Acrylic acid 11.90 Benzoyl peroxide 1.132 (containing 22% water) ~, Portion 4 .
Butyl acetate 31060 . Benzoyl peroxide 0.324 :' (containing 22% water~
: Portion 5 : :.
n-Butanol 174.10 .
.
~137~39L3 Pvrtion l is char~ed into a ~eaction vessel equipped with ~ stirrer, a pxessu~e equ~lizer addition ~unnel, con-denser, a thermometer, a heating mantle ~nd heated to its reflux temperature of about 120~C~ Portion 2 ~s added in about one minute to initiat~ polymerization t followed by the addition of portion 3 at a uniform rate~ This addition is complete in 90 minutes. Portion 4 is then added over a 60-minute period, at a uniform rate, while a slight reflux is maintained. After a further 15-minute period portion 5 is added.
The resulting polymer solution has a polymer solids content of about 55% by weight indicating ~hat monomer - conversion is substantially complete. The polymer has the composition methyl methacrylate/lauryl methacrylate/n-butyl acrylate/2-hydroxyethyl acrylate/acrylic acid in a weight ratio of 28/29/30/lO/3.
(B) A coating composition is prepared as follows:
~ ':
Parts By Portion l Weight . --White mill base (prepared in Ex .1 ) ~6 .7 Polyttler solutlon A rprepared above] 72.7 Polyesterl 30 0 Partially Methylated Melamine/
Formaldehyde Resin (80~ sollds in iso-propanol ) 25 . O
Portion 2 ~; :
Mono- and di-phenyl phosphate (20% solids in n-butanol) 2.5 - ,.-_ ~3 _ : . . ... . .. . . - :
- , ~ - . , , : .
~1343 Portion 3 n-Butanol . 110.0 (1) The polyester is prepared f'rom adipic acid, neopentyl glycol, and 1,6-he}~anediol, has a molecular weight o:~ approY.imately 1, ooO~ a h~droxyl number of 100, and an acid number of 0~5.
Por~ion 1 is blended at room temperature. The acid catalyst ~portion 2) is added and the blend thinned with 10portion ~. The resulting co~positiorl has a solids content o~
45% by weight and a pigment/binder ratio of 42/100. When cast on a s~eel sheet and cured ~or 30 minutes at 125~C a uniform i:hlte glos~y coating result~.
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EX~P~E 5 ~. _ Example 5 i5 repeated by substituting the following polymer solution as Polymer Solution A:
Polymer solution A i~ prepared as follows:
Por~ion 1 Parts By . - _~ .
Methyl methacrylate 16.1 n-Butyl methacrylate 34,0 stearyl ~ethacrylate 34.0 ; 10 2-Hydroxyethyl acrylate 6.1 Acrylic acid 1.5 n-Butanol 142.7 Portion 2 Butyl acetate 9.1 Benzoyl peroxide 0.054 : (containing 22~ water) - ::
Portion 3 :.
Methyl methacrylate .102.4 n-Butyl methacrylate 102.0 2D stear~l ~ethacrylate 102.0 2-Hydroxyethyl acrylate 38.0 Acrylic acid 11.90 .:
Benzoyl peroxide 1.132 ~containing 22% water) . .
Portion 4 .
: Butyl acetate ~ - : 31.60 :
. Benzoyl peroxide : 0.324 : ;~
(containing 22% water) .
- 25 - :
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L3~l3 Portion_ 5 17~ . 10 n-Butanol ~ .
~oxti~n 1 i~ ch~r~ed into a xeaction ~essel e~uipped with ~ stixre~, a pxe~suxe e~ualiæer addition ~unnel, con-denser, a ~hermometer, a he~,ting Tn~ntle and heated to its re~lux temper~ture of about 120C~ Portion ~ is added in about one minute to initiate pol~merization, followed by the addition o portion 3 at a uniform rate. This addi~ion i9 complete in 90 minutes. Portion 4 is then added over a 60-mi~u~e period, at a uniform xate, while a sli~ht reflux ismaintained. Ater a further 15-minute period portion 5 is added.
` The resulting polymer solution has a polymer solids :~ content o~ about 55% by weight indicating that monomer ~; ~on~ersion is substantially complete. The polymer has the ~, . composition ~ethyl methacrylate/stearyl methacrylate/n-butyl : . . . ~ .
: methacrylate/2-hydroxyethyl acrvlate/acrylic acid in a weight ratio of 28/29/30/10/3.
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-~ 7~3~3 (B) A coating composition is prepared as follows:
Parts By , Port~on 1 ei~ht ~hlte mill ~ase (prepa~ed in Ex.l) 66~7 Polymer solution A ~prepared above ] . 72 0 7 Polyes~er 3O.O
Partially Methylated Melam$ne/
1~ Formaldehyde Xesin (8O~ solids in iso-propanvl) . ~5,O.
Portion 2 , ~Mono- and di-phenyl phosphate :~(20~ solids ln n-butanol) 2.5 . :~
, Portion 3 n Rutanol . llO~O
The polyester ~.s prepared ~rom adipic acid, neopentyl glycol, and.l,6-hexanediol~ has a molecular weight of approxi~a~ely l,OOO, a ~20 hydroxyl number o~ lOO~ and an acid n~,~ber ~f O~5. ;:
.
. Portion 1 is blended at room temperature. The aci~
~ataly~t (portion 2) is added and the blend thinned ~ith port~on 3. The resulting co~position has a solids content of :
45% by weig~t and a pigment/binder ratio of 42/lOO. When ~ ~ .
~cast on a s~eel ~heet and cu~ed for 3O minutes at 125C a ::.
uniform white glossy ~oat~ng resul~s.
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~C3 7:~3~3 E~MPLE 7 Example 5 is repeated by substikuting the following polymer solution as Polymer Solution A:
Polymer solution A is pxepared as ~ollows;
P~rtion 1 Par~s By Methyl methacrylate 16.1 ~auryl methacrylate 68.0 2-Hydroxyethyl acrylate 6.1 Acrylic acid 1.5 n Butanol 142.7 Portion 2 Butyl acetate 9.1 .
Benzoyl peroxide 0.054 I ~containing 22~ water) !
Portion 3 :
Methyl methacrylate ~ 102.4 Lauryl methacrylate 204.0 2-Hydroxyethyl acrylate 38.0 Acrylic acid .11.90 Benzoyl peroxide 1.132 ~containing 22% water) Portion 4 .
Butyl acetate ~ 31.60 Benzoyl peroxide 0.324 (containing 22% water) ;: ~Portion~S
~n-Butanol 174.10 .'', . .
~7~343 ''.. : :
.
Po~tion l is ch~rged int~ a reaction vessel equipped ~ith ~ stirrex, ~ p~essure equ~lizer addition .funnel, con-denser, a thermometer, and ~ h.eatin~ mantle .and heated to its reflux temperature of ahout 120~C~ Portion 2 is added in about one minute to initiate polymeri~ation, followed by the addition of portion 3 at a uniform rate~ This addition is complete in 90 minutes. Portion 4 is then added over a 60- :
minute period, at a uniform rate, while a slight reflux is ::
maintained, After a further 15-minute period portion 5 is added.
The resulting polymer solution has a polymer solids ~. :
. . content of about 55% by weight indicating that monomer con-- version is substantially complete. The polymer has the com-position: methyl methacrylate/lauryl methacrylate/2-hydroxy-ethyl acrylate/ acrylic acid in a weight ratio of 28/5g/10/3.
The coating obtained utilizing this polymer cured for 30 minutes at 125C on a steel sheet is uniform, glossy, and flexible. :~:
.
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~C~7~3~3 ~X~pL~ 8 When Examples 5, 6, and 7 are repeated utilizing aluminum flakes as 5hown in Example 3, instead of the white mill base from Example 1, and the coatings are cured, either on a flexi~le substrate or on steel, the enamels have excellent gloss retention, as indicated by outdoor exposure or under - simulated conditions.
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(5~ The benzophenone coated surface is exposed to a ~:~
quartz-~acketed mercury vapor cont,~ining 0.05-0.4 ~oules/square centimeter of radiation in the wave length band of 365 ~ 5nm and allowed to cool to abQut 50C.
rrhe rubber substrat.e with the activated surface then is ~prayed with the above compostion and baked as indicated above. A uniform silver-gray metallic finish, having excellent gloss, Fesults.
* denotes trade mark ~. ~
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A c~ating composition is prepared as follows:
Parts By Portion 1 White mill base (prepared in Ex.l) 66.7 Polymer solution A rrepared in Example 1 (A~7 72~7 Polyester ~o.o Par~ially Methy~ated Melamine/
Formaldehyde Resin (80% solids in iso-propanol) 25.0 Portion 2 Mono- and di-phenyl phosphate (20~ solids in n-butanol) 2.5 Portion 3 .
n-Butanol 110.0 (1~ The polyester is prepared from adipic acld, neopentyl glycol, and 1,6-hexanediol, ha.s a molecular weight of approximately 1,000, a hydroxyl number of 100, and an acid number of 0.5.
Por~ion 1 is blended at room temperature~ The acid catalyst (portion 2) is added and the blend thinned with portion ~0 The resulting composition has a solids content o.f 45~ by weight and a pigment/binder ratio of 42/100~ When cast on a steel sheet and cured for 30 minutes at 125C a uniform white glossy coating results.
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~.(171 343 EX~PLE 5 (A?
Polymer solution A is prepared as ~ollows:
Portion 1 Par~s By ` '~
Methyl methacrylate 16.1 n-Butyl acrylate 34.0 Lauryl methacrylate 34.0 2-~ydroxyethyl acrylate 6.1 Acrylic acid 1.5 n Butanol 142.7 Portion 2 Butyl acetate 9.1 Ben~oyl peroxide 0.054 (containing 22~ water) Portion 3 .
I Methyl methacrylate 102.4 : ~-Butyl acrylate 102.0 Lauryl methacrylate 102.0 2-Hydroxyethyl acrylate . 38.0 ~0 Acrylic acid 11.90 Benzoyl peroxide 1.132 (containing 22% water) ~, Portion 4 .
Butyl acetate 31060 . Benzoyl peroxide 0.324 :' (containing 22% water~
: Portion 5 : :.
n-Butanol 174.10 .
.
~137~39L3 Pvrtion l is char~ed into a ~eaction vessel equipped with ~ stirrer, a pxessu~e equ~lizer addition ~unnel, con-denser, a thermometer, a heating mantle ~nd heated to its reflux temperature of about 120~C~ Portion 2 ~s added in about one minute to initiat~ polymerization t followed by the addition of portion 3 at a uniform rate~ This addition is complete in 90 minutes. Portion 4 is then added over a 60-minute period, at a uniform rate, while a slight reflux is maintained. After a further 15-minute period portion 5 is added.
The resulting polymer solution has a polymer solids content of about 55% by weight indicating ~hat monomer - conversion is substantially complete. The polymer has the composition methyl methacrylate/lauryl methacrylate/n-butyl acrylate/2-hydroxyethyl acrylate/acrylic acid in a weight ratio of 28/29/30/lO/3.
(B) A coating composition is prepared as follows:
~ ':
Parts By Portion l Weight . --White mill base (prepared in Ex .1 ) ~6 .7 Polyttler solutlon A rprepared above] 72.7 Polyesterl 30 0 Partially Methylated Melamine/
Formaldehyde Resin (80~ sollds in iso-propanol ) 25 . O
Portion 2 ~; :
Mono- and di-phenyl phosphate (20% solids in n-butanol) 2.5 - ,.-_ ~3 _ : . . ... . .. . . - :
- , ~ - . , , : .
~1343 Portion 3 n-Butanol . 110.0 (1) The polyester is prepared f'rom adipic acid, neopentyl glycol, and 1,6-he}~anediol, has a molecular weight o:~ approY.imately 1, ooO~ a h~droxyl number of 100, and an acid number of 0~5.
Por~ion 1 is blended at room temperature. The acid catalyst ~portion 2) is added and the blend thinned with 10portion ~. The resulting co~positiorl has a solids content o~
45% by weight and a pigment/binder ratio of 42/100. When cast on a s~eel sheet and cured ~or 30 minutes at 125~C a uniform i:hlte glos~y coating result~.
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EX~P~E 5 ~. _ Example 5 i5 repeated by substituting the following polymer solution as Polymer Solution A:
Polymer solution A i~ prepared as follows:
Por~ion 1 Parts By . - _~ .
Methyl methacrylate 16.1 n-Butyl methacrylate 34,0 stearyl ~ethacrylate 34.0 ; 10 2-Hydroxyethyl acrylate 6.1 Acrylic acid 1.5 n-Butanol 142.7 Portion 2 Butyl acetate 9.1 Benzoyl peroxide 0.054 : (containing 22~ water) - ::
Portion 3 :.
Methyl methacrylate .102.4 n-Butyl methacrylate 102.0 2D stear~l ~ethacrylate 102.0 2-Hydroxyethyl acrylate 38.0 Acrylic acid 11.90 .:
Benzoyl peroxide 1.132 ~containing 22% water) . .
Portion 4 .
: Butyl acetate ~ - : 31.60 :
. Benzoyl peroxide : 0.324 : ;~
(containing 22% water) .
- 25 - :
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, . , ~ . .
L3~l3 Portion_ 5 17~ . 10 n-Butanol ~ .
~oxti~n 1 i~ ch~r~ed into a xeaction ~essel e~uipped with ~ stixre~, a pxe~suxe e~ualiæer addition ~unnel, con-denser, a ~hermometer, a he~,ting Tn~ntle and heated to its re~lux temper~ture of about 120C~ Portion ~ is added in about one minute to initiate pol~merization, followed by the addition o portion 3 at a uniform rate. This addi~ion i9 complete in 90 minutes. Portion 4 is then added over a 60-mi~u~e period, at a uniform xate, while a sli~ht reflux ismaintained. Ater a further 15-minute period portion 5 is added.
` The resulting polymer solution has a polymer solids :~ content o~ about 55% by weight indicating that monomer ~; ~on~ersion is substantially complete. The polymer has the ~, . composition ~ethyl methacrylate/stearyl methacrylate/n-butyl : . . . ~ .
: methacrylate/2-hydroxyethyl acrvlate/acrylic acid in a weight ratio of 28/29/30/10/3.
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-~ 7~3~3 (B) A coating composition is prepared as follows:
Parts By , Port~on 1 ei~ht ~hlte mill ~ase (prepa~ed in Ex.l) 66~7 Polymer solution A ~prepared above ] . 72 0 7 Polyes~er 3O.O
Partially Methylated Melam$ne/
1~ Formaldehyde Xesin (8O~ solids in iso-propanvl) . ~5,O.
Portion 2 , ~Mono- and di-phenyl phosphate :~(20~ solids ln n-butanol) 2.5 . :~
, Portion 3 n Rutanol . llO~O
The polyester ~.s prepared ~rom adipic acid, neopentyl glycol, and.l,6-hexanediol~ has a molecular weight of approxi~a~ely l,OOO, a ~20 hydroxyl number o~ lOO~ and an acid n~,~ber ~f O~5. ;:
.
. Portion 1 is blended at room temperature. The aci~
~ataly~t (portion 2) is added and the blend thinned ~ith port~on 3. The resulting co~position has a solids content of :
45% by weig~t and a pigment/binder ratio of 42/lOO. When ~ ~ .
~cast on a s~eel ~heet and cu~ed for 3O minutes at 125C a ::.
uniform white glossy ~oat~ng resul~s.
~..' ~ : ' . ~'. .;
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. .
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~C3 7:~3~3 E~MPLE 7 Example 5 is repeated by substikuting the following polymer solution as Polymer Solution A:
Polymer solution A is pxepared as ~ollows;
P~rtion 1 Par~s By Methyl methacrylate 16.1 ~auryl methacrylate 68.0 2-Hydroxyethyl acrylate 6.1 Acrylic acid 1.5 n Butanol 142.7 Portion 2 Butyl acetate 9.1 .
Benzoyl peroxide 0.054 I ~containing 22~ water) !
Portion 3 :
Methyl methacrylate ~ 102.4 Lauryl methacrylate 204.0 2-Hydroxyethyl acrylate 38.0 Acrylic acid .11.90 Benzoyl peroxide 1.132 ~containing 22% water) Portion 4 .
Butyl acetate ~ 31.60 Benzoyl peroxide 0.324 (containing 22% water) ;: ~Portion~S
~n-Butanol 174.10 .'', . .
~7~343 ''.. : :
.
Po~tion l is ch~rged int~ a reaction vessel equipped ~ith ~ stirrex, ~ p~essure equ~lizer addition .funnel, con-denser, a thermometer, and ~ h.eatin~ mantle .and heated to its reflux temperature of ahout 120~C~ Portion 2 is added in about one minute to initiate polymeri~ation, followed by the addition of portion 3 at a uniform rate~ This addition is complete in 90 minutes. Portion 4 is then added over a 60- :
minute period, at a uniform rate, while a slight reflux is ::
maintained, After a further 15-minute period portion 5 is added.
The resulting polymer solution has a polymer solids ~. :
. . content of about 55% by weight indicating that monomer con-- version is substantially complete. The polymer has the com-position: methyl methacrylate/lauryl methacrylate/2-hydroxy-ethyl acrylate/ acrylic acid in a weight ratio of 28/5g/10/3.
The coating obtained utilizing this polymer cured for 30 minutes at 125C on a steel sheet is uniform, glossy, and flexible. :~:
.
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~C~7~3~3 ~X~pL~ 8 When Examples 5, 6, and 7 are repeated utilizing aluminum flakes as 5hown in Example 3, instead of the white mill base from Example 1, and the coatings are cured, either on a flexi~le substrate or on steel, the enamels have excellent gloss retention, as indicated by outdoor exposure or under - simulated conditions.
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Claims (26)
1. A thermosetting acrylic enamel wherein the film-forming constituents comprise:
(A) 20-80% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 0-97% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 3-15% by weight, based on the weight of the polymer, of a hydroxalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 0-90% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-18 carbon atoms in the alkyl group or a mixture of alkyl methacrylates having 1-18 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; provided that when the alkyl acrylate of (1) is not present, there is present at least 20% by weight, based on the weight of the polymer, of such alkyl methacrylate having 6-18 carbon atoms in the alkyl group; and (4) 0-10% by weight, based on the weight of the polymer, of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid;
wherein components (1) through (4) total 100%, said acrylic polymer has an inherent viscosity, at 25°C, of 0.05-0.35, as determined as a 0.5%
solution in 1,2-dichloroethane, and a glass transition temperature not exceeding 60°C;
(B) 10-50% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from linear or branched chain diol, including ether glycols, or mixtures thereof or mixtures of diols and triols, containing up to and including 8 carbon atoms and a dicarboxylic acid, an anhydride thereof or mixtures of dicarboxylic acids containing up to and includ-ing 12 carbon atoms, wherein at least 75% by weight, based on the weight of dicarboxylic acid, is an aliphatic dicarboxylic acid; where-in said polyester has a molecular weight not exceeding 2,000, a hydroxyl number range of 50-150, a maximum acid number of 10, and a glass transition temperature below 0°C; and (C) 10-40% by weight, based on the weight of (A) plus (B) plus (C), of an alkylated amine-aldehyde resin, and alkylated amide-aldehyde resin or mixtures thereof.
(A) 20-80% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 0-97% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 3-15% by weight, based on the weight of the polymer, of a hydroxalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 0-90% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-18 carbon atoms in the alkyl group or a mixture of alkyl methacrylates having 1-18 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; provided that when the alkyl acrylate of (1) is not present, there is present at least 20% by weight, based on the weight of the polymer, of such alkyl methacrylate having 6-18 carbon atoms in the alkyl group; and (4) 0-10% by weight, based on the weight of the polymer, of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid;
wherein components (1) through (4) total 100%, said acrylic polymer has an inherent viscosity, at 25°C, of 0.05-0.35, as determined as a 0.5%
solution in 1,2-dichloroethane, and a glass transition temperature not exceeding 60°C;
(B) 10-50% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from linear or branched chain diol, including ether glycols, or mixtures thereof or mixtures of diols and triols, containing up to and including 8 carbon atoms and a dicarboxylic acid, an anhydride thereof or mixtures of dicarboxylic acids containing up to and includ-ing 12 carbon atoms, wherein at least 75% by weight, based on the weight of dicarboxylic acid, is an aliphatic dicarboxylic acid; where-in said polyester has a molecular weight not exceeding 2,000, a hydroxyl number range of 50-150, a maximum acid number of 10, and a glass transition temperature below 0°C; and (C) 10-40% by weight, based on the weight of (A) plus (B) plus (C), of an alkylated amine-aldehyde resin, and alkylated amide-aldehyde resin or mixtures thereof.
2. The thermosetting acrylic enamel of Claim 1 wherein said acrylic polymer comprises 20-80% of said film-forming constituents and consists essentially of:
(1) 20-40% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or meth-acrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 10-45% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group;
(4) 1-5% by weight, based on the weight of the polymer, of at least one.alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid; methacrylic acid, itaconic acid, and crotonic acid; and (5) 20-60% by weight, based on the weight of the polymer, of an alkyl methacrylate having 12-16 carbon atoms in the alkyl group, the sum of the weights of (3) and (5) not exceeding 90% of the weight of the polymer.
(1) 20-40% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or meth-acrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 10-45% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group;
(4) 1-5% by weight, based on the weight of the polymer, of at least one.alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid; methacrylic acid, itaconic acid, and crotonic acid; and (5) 20-60% by weight, based on the weight of the polymer, of an alkyl methacrylate having 12-16 carbon atoms in the alkyl group, the sum of the weights of (3) and (5) not exceeding 90% of the weight of the polymer.
3. The thermosetting acrylic enamel of Claim 1 wherein said acrylic polymer comprises 20-80% of said film-forming constituents and consists essentially of:
(1) 20-60% by weight, based on the weight of the polymer, of an alkyl methacrylate having 12-16 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-3 carbon atoms in the alkyl group or mixtures thereof;
(3) 20-65% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group;
(4) 1-5% by weight, based on the weight of the polymer, of a least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, meth-acrylic acid, itaconic acid, and crotonic acid, the sum of the weight of (1) and (3) not ex-ceeding 90% of the weight of the polymer.
(1) 20-60% by weight, based on the weight of the polymer, of an alkyl methacrylate having 12-16 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-3 carbon atoms in the alkyl group or mixtures thereof;
(3) 20-65% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group;
(4) 1-5% by weight, based on the weight of the polymer, of a least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, meth-acrylic acid, itaconic acid, and crotonic acid, the sum of the weight of (1) and (3) not ex-ceeding 90% of the weight of the polymer.
4. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of:
(A) 20-80% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 10-97% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 3-15% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 0-90% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group or a mixture of alkyl methacrylates having 1-4 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; and (4) 0-10% by weight, based on the weight of the polymer, of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid;
wherein components (1) through (4) total 100%, said acrylic polymer has an inherent viscosity, at 25°C, of 0.05-0.35, as determined as a 0.5%
solution in 1,2-dichloroethane, and a glass transition temperature not exceeding 60°C;
(B) 10-50% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from a linear or branched chain diol, including ether glycols, or mixtures thereof or mixtures of diols and triols, containing up to and acid, an anhydride thereof or mixtures of dicarboxylic acids containing up to and includ-ing 12 carbon atoms, wherein at least 75% by weight, based on the weight of dicarboxylic acid, is an aliphatic dicarboxylic acid; where-in said polyester has a molecular weight not exceeding 2,000, a hydroxyl number range of 50-150, a maximum acid number of 10, and a glass transition temperature below 0°C; and (C) 10-40% by weight, based on the weight of (A) plus (B) plus (C), of an alkylated amine-aldehyde resin, an amide-aldehyde resin or mixtures thereof.
(A) 20-80% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 10-97% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 3-15% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 0-90% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group or a mixture of alkyl methacrylates having 1-4 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; and (4) 0-10% by weight, based on the weight of the polymer, of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid;
wherein components (1) through (4) total 100%, said acrylic polymer has an inherent viscosity, at 25°C, of 0.05-0.35, as determined as a 0.5%
solution in 1,2-dichloroethane, and a glass transition temperature not exceeding 60°C;
(B) 10-50% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from a linear or branched chain diol, including ether glycols, or mixtures thereof or mixtures of diols and triols, containing up to and acid, an anhydride thereof or mixtures of dicarboxylic acids containing up to and includ-ing 12 carbon atoms, wherein at least 75% by weight, based on the weight of dicarboxylic acid, is an aliphatic dicarboxylic acid; where-in said polyester has a molecular weight not exceeding 2,000, a hydroxyl number range of 50-150, a maximum acid number of 10, and a glass transition temperature below 0°C; and (C) 10-40% by weight, based on the weight of (A) plus (B) plus (C), of an alkylated amine-aldehyde resin, an amide-aldehyde resin or mixtures thereof.
5. m e thermosetting acrylic enamel of Claim 4 wherein said acrylic polymer comprises 20-80% of said film-forming constituents and consists essentially of:
(1) 53-75% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 10-30% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group or a mixture of alkyl methacrylate having 1-4 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the polymer, of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid.
(1) 53-75% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 10-30% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group or a mixture of alkyl methacrylate having 1-4 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the polymer, of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid.
6. The thermosetting acrylic enamel of Claim 4 wherein said acrylic polymer comprises 30-60% of said film-forming constituents and consists essentially of:
(1) 53-75% by weight, based on the weight of the acrylic polymer, of butyl acrylate;
(2) 6-12% by weight, based on the weight of the acrylic polymer, of hydroxyethyl acrylate;
(3) 10-30% by weight, based on the weight of the acrylic polymer, of methyl meth-acrylate and styrene, wherein the weight of styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the acrylic polymer, of acrylic acid, meth-acrylic acid or mixtures thereof.
(1) 53-75% by weight, based on the weight of the acrylic polymer, of butyl acrylate;
(2) 6-12% by weight, based on the weight of the acrylic polymer, of hydroxyethyl acrylate;
(3) 10-30% by weight, based on the weight of the acrylic polymer, of methyl meth-acrylate and styrene, wherein the weight of styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the acrylic polymer, of acrylic acid, meth-acrylic acid or mixtures thereof.
7. The thermosetting acrylic enamel of Claim 1 wherein said polyester comprises 20-40% by weight of said film-forming constituents and is prepared from at least one diol selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2-ethyl-1,3-hexanediol, neopentyl glycol, 2-methyl-2ethyl-1,3-propane-diol, 1,6-hexanediol, diethylene glycol, and triethylene glycol or a mixture of diol with a triol selected from the group consisting of trimethylolpropane, trimethylolethane, glycerol, and 1,2,6-hexanetriol and an aliphatic dicarboxylic acid, an anhydride thereof or mixtures of dicarboxylic acids, wherein at least 75% by weight, based on the weight of said mixture, is an aliphatic dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, azelaic acid, dodecanedioic acid, and the isomeric phthalic acids.
8. The thermosetting acrylic enamel of Claim 1 wherein said nitrogen resin crosslinking agent comprises 15-35% by weight of said film-forming constituents and is an alkylated melamine-formaldehyde resin.
9. The thermosetting acrylic enamel of Claim 4 wherein said acrylic polymer consists essentially of:
(1) 85-97% by weight, based on the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group, and (2) 3-15% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof.
(1) 85-97% by weight, based on the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group, and (2) 3-15% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof.
10. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of:
(A) 30-60% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer con-sisting essentially of:
(1) 53-75% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 10-30% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group or a mixture of alkyl methacrylate having 1-4 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the acrylic polymer, of acrylic acid, meth-acrylic acid or mixtures thereof.
wherein components (1) through (4) total 100%, said acrylic polymer has an inherent viscosity at 25°C, of 0.05-0.35, as determined as a 0.5%
solution in 1,2-dichloroethane, and a glass transition temperature not exceeding 60°C;
(B) 20-40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from at least one diol selected from the group consisting of ethylene glycol, 1,2,-propylene glycol, 1,3-propylene glycol, 1,2,-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2-ethyl-1,3-hexanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 1,6-hexanediol, diethylene glycol, and triethylene glycol or a mixture of a diol with a triol selected from the group consisting of tri-methylolpropane, trimethylolethane, glycerol, and 1,2,6-hexanetriol and an aliphatic di-carboxylic acid, an anhydride thereof or mixtures of dicarboxylic acids, wherein at least 75% by weight, based on the weight of said mixture, is an aliphatic dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, azelaic acid, and the isomeric phthalic acids; wherein said polyester has a molecular weight not exceeding 2,000, a hydroxyl number range of 50-150, a maximum acid number of 10, and a glass transi-tion temperature below 0°C; and (C) 15-35% by weight, based on the weight of (A) plus (B) plus (C), of an alkylated melamine-formaldehyde resin crosslinking agent.
(A) 30-60% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer con-sisting essentially of:
(1) 53-75% by weight, based on the weight of the polymer, of an alkyl acrylate having 2-8 carbon atoms in the alkyl group;
(2) 6-12% by weight, based on the weight of the polymer, of a hydroxyalkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group or mixtures thereof;
(3) 10-30% by weight, based on the weight of the polymer, of an alkyl methacrylate having 1-4 carbon atoms in the alkyl group or a mixture of alkyl methacrylate having 1-4 carbon atoms in the alkyl group and styrene, wherein styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the acrylic polymer, of acrylic acid, meth-acrylic acid or mixtures thereof.
wherein components (1) through (4) total 100%, said acrylic polymer has an inherent viscosity at 25°C, of 0.05-0.35, as determined as a 0.5%
solution in 1,2-dichloroethane, and a glass transition temperature not exceeding 60°C;
(B) 20-40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from at least one diol selected from the group consisting of ethylene glycol, 1,2,-propylene glycol, 1,3-propylene glycol, 1,2,-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2-ethyl-1,3-hexanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 1,6-hexanediol, diethylene glycol, and triethylene glycol or a mixture of a diol with a triol selected from the group consisting of tri-methylolpropane, trimethylolethane, glycerol, and 1,2,6-hexanetriol and an aliphatic di-carboxylic acid, an anhydride thereof or mixtures of dicarboxylic acids, wherein at least 75% by weight, based on the weight of said mixture, is an aliphatic dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, azelaic acid, and the isomeric phthalic acids; wherein said polyester has a molecular weight not exceeding 2,000, a hydroxyl number range of 50-150, a maximum acid number of 10, and a glass transi-tion temperature below 0°C; and (C) 15-35% by weight, based on the weight of (A) plus (B) plus (C), of an alkylated melamine-formaldehyde resin crosslinking agent.
11. The thermosetting acrylic enamel of Claim 10 wherein said acrylic polymer consists essentially of:
(1) 53-75% by weight, based on the weight of the acrylic polymer, of butyl acrylate;
(2) 6-12% by weight, based on the weight of the acrylic polymer, of hydroxethyl acrylate;
(3) 10-30% by weight, based on the weight of the acrylic polymer, of methyl methacrylate or a mixture of methyl methacrylate and styrene, wherein the weight of styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the acrylic polymer, of acrylic acid, methacrylic acid or mixtures thereof.
(1) 53-75% by weight, based on the weight of the acrylic polymer, of butyl acrylate;
(2) 6-12% by weight, based on the weight of the acrylic polymer, of hydroxethyl acrylate;
(3) 10-30% by weight, based on the weight of the acrylic polymer, of methyl methacrylate or a mixture of methyl methacrylate and styrene, wherein the weight of styrene does not exceed 75% by weight of said mixture; and (4) 1-5% by weight, based on the weight of the acrylic polymer, of acrylic acid, methacrylic acid or mixtures thereof.
12. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of:
(A) 20% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 61% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 26% by weight, based on the weight of the polymer, of methyl methacrylate; and (4) 3% by weight, based on the weight of the polymer, of acrylic acid; and 10% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 38% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 8% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 50% by weight, based on the weight of the polymer, of styrene; and (4) 4% by weight, based on the weight of the polymer, of acrylic acid;
said acrylic polymer has an inherent viscosity, at 25°C, of 0.1-0.3 as determined as a 0.5%
solution in 1,2-dichloroethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester has a molecular weight not exceeding 2,000, a maximum acid number of 5,and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine formalde-hyde crosslinking agent;
wherein the enamel also contains pigment.
(A) 20% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 61% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 26% by weight, based on the weight of the polymer, of methyl methacrylate; and (4) 3% by weight, based on the weight of the polymer, of acrylic acid; and 10% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 38% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 8% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 50% by weight, based on the weight of the polymer, of styrene; and (4) 4% by weight, based on the weight of the polymer, of acrylic acid;
said acrylic polymer has an inherent viscosity, at 25°C, of 0.1-0.3 as determined as a 0.5%
solution in 1,2-dichloroethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester has a molecular weight not exceeding 2,000, a maximum acid number of 5,and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine formalde-hyde crosslinking agent;
wherein the enamel also contains pigment.
13. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of:
(A) 30% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 61% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 26% by weight, based on the weight of the polymer, of methyl methacrylate; and (4) 3% by weight, based on the weight of the polymer, of acrylic acid;
wherein said acrylic polymer has an inherent viscosity at 25°C, of 0.1 to 0.3 as determined as a 0.5% solution in 1,2-dichloroethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester hag a molecular weight not exceeding 2,000, a maximum acid number of 5, and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine formalde-hyde crosslinking agent;
wherein the enamel also contains pigment.
(A) 30% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 61% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 26% by weight, based on the weight of the polymer, of methyl methacrylate; and (4) 3% by weight, based on the weight of the polymer, of acrylic acid;
wherein said acrylic polymer has an inherent viscosity at 25°C, of 0.1 to 0.3 as determined as a 0.5% solution in 1,2-dichloroethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester hag a molecular weight not exceeding 2,000, a maximum acid number of 5, and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine formalde-hyde crosslinking agent;
wherein the enamel also contains pigment.
14. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of:
(A) 40% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 61% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 26% by weight, based on the weight of the polymer, of methyl methacrylate; and (4) 3% by weight, based on the weight of the polymer, of acrylic acid; and 10% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of;
(1) 38% by weight, based on the weight of the polymer, of butyl acrylate, (2) 8% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 50% by weight, based on the weight of the polymer, of styrene; and (4) 4% by weight, based on the weight of the polymer, of acrylic acid;
said acrylic polymer has an inherent viscosity, at 25°C, of 0.1-0.3 as determined as a 0.5% solu-tion in 1,2-dichloroethane;
(B) 30% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol, 1,6-hexanediol, and adipic acid, wherein said polyester has a molecular weight between 700-1300, a hydroxyl number range of 70-110, and a maximum acid number of 5; and (C) 20% by weight, based on the weight of (A) plus (B) plus (C), of a partially methylated melamine formaldehyde crosslinking agent;
wherein the enamel also contains pigment.
(A) 40% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 61% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 26% by weight, based on the weight of the polymer, of methyl methacrylate; and (4) 3% by weight, based on the weight of the polymer, of acrylic acid; and 10% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of;
(1) 38% by weight, based on the weight of the polymer, of butyl acrylate, (2) 8% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 50% by weight, based on the weight of the polymer, of styrene; and (4) 4% by weight, based on the weight of the polymer, of acrylic acid;
said acrylic polymer has an inherent viscosity, at 25°C, of 0.1-0.3 as determined as a 0.5% solu-tion in 1,2-dichloroethane;
(B) 30% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol, 1,6-hexanediol, and adipic acid, wherein said polyester has a molecular weight between 700-1300, a hydroxyl number range of 70-110, and a maximum acid number of 5; and (C) 20% by weight, based on the weight of (A) plus (B) plus (C), of a partially methylated melamine formaldehyde crosslinking agent;
wherein the enamel also contains pigment.
15. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of:
(A) 30% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 30% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 28% by weight, based on the weight of the polymer, of methyl methacrylate;
(4) 3% by weight, based on the weight of the polymer, of acrylic acid; and (5) 29% by weight, based on the weight of the polymer, of lauryl methacrylate;
wherein said acrylic polymer has an inherent viscosity, at 25°C, of 0.1 to 0.3 as determined as a 0.5% solution in 1,2-dichloroethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester has a molecular weight not exceeding 2,000, a maximum acid number of 5, and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine for-maldehyde crosslinking agent;
wherein the enamel also contains pigment.
(A) 30% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 30% by weight, based on the weight of the polymer, of butyl acrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 28% by weight, based on the weight of the polymer, of methyl methacrylate;
(4) 3% by weight, based on the weight of the polymer, of acrylic acid; and (5) 29% by weight, based on the weight of the polymer, of lauryl methacrylate;
wherein said acrylic polymer has an inherent viscosity, at 25°C, of 0.1 to 0.3 as determined as a 0.5% solution in 1,2-dichloroethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester has a molecular weight not exceeding 2,000, a maximum acid number of 5, and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine for-maldehyde crosslinking agent;
wherein the enamel also contains pigment.
16. A thermosetting acrylic enamel wherein the film-forming constituents consist essentially of;
(A) 30% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 59% by weight, based on the weight of the polymer, of lauryl methacrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 28% by weight, based on the weight of the polymer, of methyl methacrylate;
(4) 3% by weight, based on the weight of the polymer, of acrylic acid;
wherein said acrylic polymer has an inherent viscosity, at 25°C, of 0.1 to 0.3 as determined as a 0.5% solution in 1,2-dichlorethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester has a molecular weight not exceeding 2,000, a maximum acid number of 5, and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine for-maldehyde crosslinking agent;
wherein the enamel also contains pigment.
(A) 30% by weight, based on the weight of (A) plus (B) plus (C), of an acrylic polymer consisting essentially of:
(1) 59% by weight, based on the weight of the polymer, of lauryl methacrylate;
(2) 10% by weight, based on the weight of the polymer, of 2-hydroxyethyl acrylate;
(3) 28% by weight, based on the weight of the polymer, of methyl methacrylate;
(4) 3% by weight, based on the weight of the polymer, of acrylic acid;
wherein said acrylic polymer has an inherent viscosity, at 25°C, of 0.1 to 0.3 as determined as a 0.5% solution in 1,2-dichlorethane;
(B) 40% by weight, based on the weight of (A) plus (B) plus (C), of a polyester prepared from neopentyl glycol and adipic acid; wherein said polyester has a molecular weight not exceeding 2,000, a maximum acid number of 5, and a hydroxyl number range of 70-110; and (C) 30% by weight, based on the weight of (A) plus (B) plus (C), of a butylated melamine for-maldehyde crosslinking agent;
wherein the enamel also contains pigment.
17. A flexible substrate coated with the thermo-setting acrylic enamel of Claim 12.
18. A flexible substrate coated with the thermo-setting acrylic enamel of Claim 13.
19. A flexible substrate coated with the thermo-setting acrylic enamel of Claim 14.
20. A flexible substrate coated with the thermo-setting acrylic enamel of Claim 15.
21. A flexible substrate coated with the thermo-setting acrylic enamel of Claim 16.
22. A metallic substrate coated with the thermo-setting acrylic enamel of Claim 12.
23. A metallic substrate coated with the thermo-setting acrylic enamel of Claim 13.
24. A metallic substrate coated with the thermo-setting acrylic enamel of Claim 14.
25. A metallic substrate coated with the thermo-setting acrylic enamel of Claim 15.
26. A metallic substrate coated with the thermo-setting acrylic enamel of Claim 16.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US56293875A | 1975-03-27 | 1975-03-27 | |
| US64569275A | 1975-12-31 | 1975-12-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071343A true CA1071343A (en) | 1980-02-05 |
Family
ID=27073126
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA248,866A Expired CA1071343A (en) | 1975-03-27 | 1976-03-25 | Flexible thermosetting acrylic enamels |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1071343A (en) |
-
1976
- 1976-03-25 CA CA248,866A patent/CA1071343A/en not_active Expired
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