Epoxy coating compositions with improved weatherability

Abstract

Solvent soluble epoxy-containing compositions prepared by polymerizing ethylenically unsaturated monomers such as alkyl acrylates in the presence of the reaction product of a liquid epoxy resin such as a diglycidyl ether of bisphenol A and acrylic acid and/or methacrylic acid. These compositions are useful in the preparation of coatings.

Description

BACKGROUND OF THE INVENTION

The present invention is directed to epoxy resins having improved weathering properties.

Epoxy resin coatings, particularly aromatic epoxy resin coatings usually have poor weathering characteristics. The aliphatic based epoxy resins usually have relatively good weathering characteristics but are usually deficient in such properties as a combination of hardness and flexibility (toughness) and chemical, solvent, and moisture resistance.

The epoxy resin coatings of the present invention not only have good weathering properties, they also have sufficiently good properties in one or more of the following: chemical, solvent, and moisture resistance, hardness, adhesion, and flexibility.

SUMMARY OF THE INVENTION

The present invention pertains to a solvent soluble epoxy-containing composition which comprises the product obtained by reacting in the presence of a suitable quantity of a suitable vinyl polymerization catalyst so as to effect polymerization:

(A) the reaction product obtained by reacting in the presence of a suitable quantity of a suitable catalyst (1) at least one material having from greater than 1 to about 4 ##STR1## per molecule wherein each R is independently hydrogen or a monovalent hydrocarbon group having from 1 to about 4 carbon atoms; X is --O--, --S-- or ##STR2## and wherein said material has an epoxide equivalent weight of from about 150 to about 400, preferably from about 180 to about 270; and (2) at least one of acrylic acid or methacrylic acid; wherein components (1) and (2) are present in a quantity which provides an equivalent ratio of acid groups from component (2) to epoxy groups from component (1) of from about 0.1:1 to less than about 0.5:1, preferably from about 0.2:1 to about 0.3:1; and (B) at least one monomer having at least one polymerizable ethylenically unsaturated group per molecule and which optionally contains a hydroxyl or an epoxide group; and wherein components (A) and (B) are employed in quantities such that the weight ratio vinyl monomers to epoxy resin varies from 0.4 to 2.5, preferably from 0.6 to 1.5.

The present invention also pertains to a curable composition which comprises

(I) the aforementioned epoxy-containing composition; (II) optionally a suitable quantity of a suitable solvent system; and (III) an effective quantity of a suitable curing agent and/or catalyst.

DETAILED DESCRIPTION OF THE INVENTION

Suitable materials having an average of from greater than 1 to about 4 ##STR3## per molecule include the glycidyl ethers, thioethers and esters of aromatic compounds having an average of from greater than 1 to about 4 --OH, --SH, --COOH or mixture of such groups per molecule. Particularly suitable are those compounds represented by the formulas ##STR4## wherein A is independently a divalent hydrocarbon group having from one to about 8 carbon atoms, --O--, --S--, --S--S--, ##STR5## each A' is independently a divalent hydrocarbon group having from one to about 8, preferably from 1 to about 4 carbon atoms; each R is independently hydrogen or a monovalent hydrocarbon group having from 1 to about 4 carbons; each X is independently hydrogen, bromine, chlorine or a hydrocarbon group having from one to about 8 carbon atoms; each Z is independently --O--, --S-- or ##STR6## n has a value of zero or 1; n' has an average value of from zero to about 5, preferably from zero to about 3; and m has an average value of from about 0.1 to about 4, preferably from about 0.8 to about 2.

Suitable polymerizable ethylenically unsaturated monomers which can be employed herein include, for example, C.sub.1 -C.sub.8 alkyl esters of acrylic and methacrylic acid; styrene and ring-substituted styrenes; vinyl and vinylidene halides; vinyl esters such as vinyl acetate, vinyl propionate, and the like; ethylene or propylene; dialkyl maleate or fumarate esters; acrylonitrile, mixtures thereof and the like.

Suitable catalysts for reacting the low equivalent weight epoxy resin with the acrylic or methacrylic acid include, for example, phosphines, phosphonium salts, tertiary amines, tertiary ammonium bases and salts, mixtures thereof and the like.

Suitable vinyl polymerization catalysts include, for example, benzoyl peroxide, peroxy ethers, and peroxy esters; and azo compounds such as azobis(isobutyronitrile), mixtures thereof and the like.

Suitable curing agents for the epoxy-containing material include, for example, polyamides, polyamidoamines, polyamines, polythiols, polycarboxylic acids, and carboxylic acid anhydrides, mixtures thereof and the like.

Suitable solvents which can be employed herein include, for example, aromatic hydrocarbons, ketones, esters, alcohols, and glycol ethers having boiling-points above 140.degree. C., or which can be contained by a pressure vessel if their boiling point is below 140.degree. C., mixtures thereof and the like.

In addition to the aforementioned components, the curable compositions of the present invention can include, if desired, pigments, dyes, fillers, flow control agents, fire retardant agents, mixtures thereof and the like.

The following examples are illustrative of the present invention, but are not to be construed as to limiting the scope thereof in any manner.

In the following examples, reference is made to acrylic resin and epoxy resin.

Acrylic resin means a resinous substance, soft or hard at room temperature, formed by the free-radical initiated polymerization of acrylic or methacrylic acid, their esters, or their nitriles with each other, singly, or with other vinyl monomers such as styrene, vinyl acetate, vinyl or vinylidene chloride, maleate esters, ethylene, and the like.

Epoxy resin means resinous substances characterized by containing from 1.0 to about 5, usually 2.0 to 3.5, oxirane groups per molecule, usually as the 2,3-epoxypropylether group. The resin may be a crystalline or amorphous solid, a syrup, or an oily liquid.

EXAMPLE 1

A two-liter spherical Pyrex.RTM. reaction vessel was equipped for mechanical stirring, temperature measurement and control, solvent reflux, and continuous reactants addition by means of a metering pump. To this vessel was charged the following: 452.5 gm of a liquid diglycidyl ether of bisphenol A having an average EEW of 181, 58.0 gm of glacial methacrylic acid, 6.0 gm of a 1% solution of p-methoxyphenol in methyl amyl ketone; and 0.77 gm of a 70% solution of ethyltriphenyl phosphonium acetate.acetic acid complex in methanol as a catalyst. The mixture was stirred and warmed slowly to 120.degree. C., at which point the heat of reaction caused the temperature to rise further to about 135.degree.. It then fell slowly back to 120.degree. where it was held until 2.0 hours (7200 s) after the time it first reached 120.degree. C. At this time the vessel contents were a thin, yellow clear liquid containing <0.05% by weight of methacrylic acid (by gas chromatography). This liquid was cooled, and when the temperature had fallen to 60.degree. C., a mixture of 187 ml of n-butyl acrylate and 206 ml of methyl methacrylate was added and stirred in until a clear, light-yellow liquid solution of resin-in-monomers was obtained (.about.1/2 hour, 1800 s). This solution was further cooled to <10.degree. C., and 7.5 ml (7.8 gm) of tert-butyl perbenzoate was added and stirred in. The entire cold solution, 857 ml, was then decanted into a one-liter Pyrex.RTM. reservoir attached to the reaction vessel via a metering pump.

To the now-empty vessel was charged 368.4 gm of methyl n-amyl ketone. Stirring was begun, and heat was applied to bring the liquid temperature to 150.degree. C. as quickly as possible. When the temperature was at 150.degree. C., the resin/monomers feed was started by turning on the metering pump. The pump was adjusted so that feed was completed in 3 hours and 55 minutes (14100 s). The pump hold-up was 20 ml, so the net feed-volume was 837 ml, or about 878 gm. The temperature was held at 150.degree..+-.2.degree. C. for 2.0 hours (7200 s) after completion of the feed, then the polymer solution was cooled to room temperature and bottled.

It was analyzed and was found to have the following properties.

______________________________________Appearance Clear, yellowViscosity at 25.degree. C. 6820 cps% non-volatiles as:acrylic resin, wt. 50.2epoxy resin, wt. 19.1Acrylic resin mol. wt.--M.sub.w 1.77 .times. 10.sup.5--M.sub.n 1.33 .times. 10.sup.4EEW, liquid basis 729EEW, solids basis 505______________________________________

From the above data it was possible to calculate that the acrylic resin (solids) had an epoxy (C.sub.2 H.sub.3 O) content of 1.98 weight percent and an EEW (epoxide equivalent weight) of 2171, and therefore was functional in epoxy groups to the extent of 6.1 per average polymer molecule: ##EQU1## that the acrylic copolymer resin crosslink density, (X).sub.n, was two per average molecule, and that the average molecule had a degree of polymerization of 80-81 (D.P.=80-81).

EXAMPLES 2-4 AND COMPARATIVE EXPERIMENTS A-C

The solution prepared in Example 1 was made into clear, catalyzed epoxy coating formulations as shown in Table I. Also included are comparative coatings prepared from an epoxy resin which is a diglycidyl ether of bisphenol A having an average EEW of about 500-525 designated as DGEBA as a 70% solids solution in methyl n-amyl ketone.

TABLE I______________________________________ EXAMPLE OR COMPARATIVE EXPERIMENT NO. EX- EX- EX- AM- COMP. AM- COMP. AM- COMP.COMPO- PLE EXPT. PLE EXPT. PLE EXPT.NENTS 2 A 3 B 4 C______________________________________Product from 21.0 -- 21.0 -- 21.0 --Ex. 1, gDGEBA -- 21.0 -- 21.0 -- 21.0SOLUTION,GCH .RTM. 5.0 5.0 -- -- -- --140.sup.1, gVERSA- -- -- 11.5 11.5 -- --MID .RTM.115 .times. 70.sup.2, gD.E.H. .RTM. 29.sup.3 -- -- -- -- 1.2 1.2methyl ether 5.0 5.0 5.0 5.0 5.0 5.0of propyleneglycol, gmethyl ethyl quantity required to provide spray viscosityketone, g of 250-300 cP.______________________________________ .sup.1 A polyamide curing agent having an amine hydrogen equivalent weigh of about 175 available from General Mills as Versamid 140. .sup.2 A polyamide curing agent having an amine hydrogen equivalent weight of about 375 available from General Mills. .sup.3 A polyamide curing agent having an amine hydrogen equivalent weigh of about 29 available from The Dow Chemical Company.

The clear lacquer-like solutions were spread in even films on 4".times.12" (10.16 cm.times.30.48 cm) 20-guage unpolished cold-rolled steel panels and allowed to cure in a vertical position for one week (604800 s) at 24.degree.-27.degree. C. They were then evaluated as shown in Table II.

The results demonstrate that the subject compositions are capable of being formulated to yield coatings having not only superior resistance to dulling and chalking but other properties equal or superior to those of conventional epoxy resin coatings.

TABLE II__________________________________________________________________________ EXAMPLE OR COMPARATIVE EXPERIMENT NO. COMP. COMP. COMP. EXAMPLE EXPT. EXAMPLE EXPT. EXAMPLE EXPT.PROPERTY 2 A 3 B 4 C__________________________________________________________________________GLOSS excellent good excellent very excellent very good goodHARDNESS, pencil 2H-3H H-2H F-H 2H 2H H-2HADHESION (dry) 100% 30% 100% 56% 100% 31%REVERSE IMPACT, in-lb >180 >180 >120 >180 >200 >200cm-kg >207 >207 >138 >207 >230 >230MEK DOUBLE RUBS >200 >200 >200 100-125 >200 >200LOSS OF ADHESION, 16% 100% 55% 100% 100% 100%1 hour boiling waterwater immersionSALT FOG EXPOSURE, 3/4" gross 1/2" 1/2"-3/4" gross 11/2"-2"24 hours (86400 s) (19 mm) failure (12.7 mm) (12.7 mm- failure (25.4 mm- creep in creep 19 mm) 50.8 mm) 24 hrs. creep creepQUV EXPOSURE, glossy complete- glossy complete- glossy complete-500 hours ly flat ly flat ly flat(1,800,000 s)DRY FILM THICKNESSmils 1.2-1.4 1.2-1.3 1.0-1.4 1.1-1.3 1.1-1.4 1.0-1.3mm 0.03048- 0.03048- 0.0254- 0.02794- 0.02794- 0.0254- 0.03556 0.03302 0.03556 0.03302 0.03556 0.03302__________________________________________________________________________

EXAMPLES 5-8

Employing the procedure for Example 1, various compositions were prepared. The components and characteristics are given in Table III.

The purpose of this series of experiments was to demonstrate the preparation and use of a set of copolymer resins in which the molecular weight has been varied by varying the ratio of vinyl carboxylic acid equivalents to glycidyl ether equivalents, short of gellation.

This variable (carboxyl group/epoxy group) is believed to control the molecular weight of the resulting vinyl copolymer by controlling the number of branch sites in the copolymer backbone; i.e., more branch sites results in higher molecular weight copolymer.

When the acid/epoxy ratio in this series was increased to 0.50, the solution gelled during the vinyl polymerization.

TABLE III__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLE 5 6 7 8__________________________________________________________________________COMPONENTSEPOXY RESIN.sup.1, g/equiv. 240/1.26 240/1.26 240/1.26 240/1.26METHACRYLIC ACID, g/equiv. 21.7/.252 30.7/.357 37.6/.437 48.5/.564ACID/EPOXY EQUIV. RATIO 0.2/1 0.283/1 0.346/1 0.4/11% PHENOTHIAZINE IN METHYL 10 10 10 10AMYL KETONE, gETHYLTRIPHENYLPHOSPHONIUM 0.5 0.5 0.5 0.5ACETATE.ACETIC ACID COMPLEX, gSEC-BUTYL ACRYLATE, g 133 133 133 133STYRENE, g 84.8 84.8 84.8 84.8t-BUTYL PERBENZOATE, g/mole %.sup.2 12.2/2.90 12.8/2.90 13.3/2.91 13.7/2.84METHYL AMYL KETONE, g 200 204 207 213PROPERTIESSOLUTION VISCOSITY, cps 328 757 1870 3910% NON-VOLATILES 68.8 69.1 69.1 69.2MOLECULAR WEIGHT OF THE COPOLYMER--M.sub.w 1.08 .times. 10.sup.4 1.52 .times. 10.sup.4 2.5 .times. 10.sup.4 3.7 .times. 10.sup.4--M.sub.n 7.1 .times. 10.sup.3 8.02 .times. 10.sup.3 9.45 .times. 10.sup.3 1.09 .times. 10.sup.4ACRYLIC/EPOXY, wt. % 50/50 51/49 52/48 52/48(.sup.-f).sub.n of acrylic copolymers 3.2 4.0 5.4 4.9(.sup. --X).sub.n of acrylic copolymers 0.4 0.8 1.3 0.6EEW (total solids basis) 515 590 660 800__________________________________________________________________________ .sup.1 The epoxy resin was a diglycidyl ether of bisphenol A having an average EEW of 190. .sup.2 a freeradical polymerization initiator; mol % is defined as follows: ##STR7##

EXAMPLES 9-12 AND COMP. EXPT. D-G

The solution epoxy-containing polymers of Table III were made into clear, catalyzed epoxy coatings. The components and results are given in Table IV. For comparative purposes, coatings were also prepared from glycidyl ethers of bisphenol A having equivalent weights similar to those of the examples. These comparative epoxy resins are designated in the table as DGEBA. The mixtures were all diluted to a viscosity of 120-145 cps with methyl ethyl ketone. The films were cast onto 24-guage unpolished cold-rolled steel panels and cured by allowing them to stand for one week (604800 s) at 24.degree.-27.degree. C. The compositions and results are given in Table IV.

TABLE IV__________________________________________________________________________ COMP. COMP. COMP. COMP.COMPONENTS & EXAMPLE EXPT. EXAMPLE EXPT. EXAMPLE EXPT. EXAMPLE EXPT.PROPERTIES 9 D 10 E 11 F 12 G__________________________________________________________________________COPOLYMER SOLUTION, 5/30.0 -- 6/30.0 -- 7/30.0 -- 8/30.0 --EX. NO./gGCH 14, g 7.48 7.48 6.57 6.57DGEBA SOLUTION, g -- 30.0 -- 30.0 -- 30.0 -- 30.0METHYL ETHER OF 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0PROPYLENE GLYCOL, gCURED FILM PROPERTIESGLOSS excellent excellent excellent excellent excellent excellent excellent excellentREVERSE IMPACT,in-lbs 3 130 120 110 140 140 130 140cm-kg 3.5 150 138 127 161 161 150 161FORWARD IMPACT,in-lbs 18 180 180 180 180 180 180 180cm-kg 20.7 207 207 207 207 207 207 207HARDNESS, pencil 2H 2H 2H 3H F 2H F 2HADHESION, % retained 100 100 100 100 100 100 100 100MEK DOUBLE RUBS >200 >200 >200 >200 >200 >200 >200 >200DRY FILM THICKNESS,mils 2 1.5 1.5 1.5 2 1.5 2 1.5mm 0.05 0.04 0.05 0.04 0.05 0.04 0.04 0.04GLOSS AFTER 1000 HRS fair flat fair flat good flat good flat(3.6 .times. 10.sup.6 s)QUV exposure__________________________________________________________________________

EXAMPLES 13-16

Employing the procedure for Example 1, various compositions were prepared. The components and results are given in Table V.

The purpose of this series of experiments was to demonstrate the preparation and use of a set of copolymer resins in which the molecular weight has been varied by varying the initiator concentration while holding the number of branch sites constant. Higher initiator concentrations result in shorter copolymer chains, hence fewer branch sites per molecule.

Comparison of the data of Table V with those of Table III demonstrates that variation of initiator concentration is the more effective means of obtaining high levels of epoxy functionality in the vinyl copolymer (f.sub.n) without driving up viscosity excessively. Both methods, however, are practical and yield coatings having similar properties.

When the t-butyl perbenzoate concentration was reduced to 0.50 mol %, the copolymer solution gelled during polymerization.

TABLE V__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLE 13 14 15 16__________________________________________________________________________COMPONENTSEPOXY RESIN.sup.1, g/equiv. 452.5/2.5 452.5/2.5 452.5/2.5 452.5/2.5METHACRYLIC ACID, g/equiv. 58/.674 58/.674 58/.674 58/.674ACID/EPOXY EQUIV. RATIO .270 .270 .270 .2701% p-METHOXYPHENOL IN METHYL 6.0 6.0 6.0 6.0AMYL KETONE, gETHYLTRIPHENYLPHOSPHONIUM 0.77 0.77 0.77 0.77ACETATE.ACETIC ACID COMPLEX, gn-BUTYL ACRYLATE, g 167.5 167.5 167.5 167.5METHYL METHACRYLATE, g 206.3 206.3 206.3 206.3t-BUTYL PERBENZOATE, g/mole %.sup.2 7.8/0.95 15.6/1.95 23.4/2.88 31.2/3.85METHYL AMYL KETONE, g 370 372 375 379PROPERTIESSOLUTION VISCOSITY, cps 1100 512 427 378% NON-VOLATILES 68.7 68.3 68.8 68.8MOLECULAR WEIGHT OF THE COPOLYMER--M.sub.w 5.1 .times. 10.sup.4 1.6 .times. 10.sup.4 1.2 .times. 10.sup.4 9.6 .times. 10.sup.3--M.sub.n 9.47 .times. 10.sup.3 6.8 .times. 10.sup.3 5.22 .times. 10.sup.3 4.66 .times. 10.sup.3ACRYLIC/EPOXY, wt. % 49/51 50/50 50/50 50/50(.sup.-f).sub.n of acrylic copolymers 6.6 4.3 3.5 2.9( .sup.--X).sub.n of acrylic copolymers 1.2 0.8 0.6 0.5EEW (total solids basis) 497 504 509 523__________________________________________________________________________ .sup.1 The epoxy resin was a diglycidyl ether of bisphenol A having an average EEW of 181. .sup.2 See Table III.

EXAMPLES 17-28 AND COMP. EXPT. H-J

The solution epoxy-containing polymers were made into clear catalyzed epoxy coatings. The components and results are given in Table VI. For comparative purposes, a similar coating was prepared from a diglycidyl ether of bisphenol A epoxy resin having a similar epoxide equivalent weight. This epoxy resin used for control purposes is designated as DGEBA. The compositions and results are given in Table VI.

The overall properties of these coatings are generally equal or superior to the control, with much better resistance to dulling by ultraviolet light.

TABLE VI__________________________________________________________________________ COMP. EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXPT.COMPONENTS & PROPERTIES 17 18 19 20 H__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 13/21.0 14/21.0 15/21.0 16/21.0 --DGEBA SOLUTION, g -- -- -- -- 21.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type GCH14.sup.1 GCH14 GCH14 GCH14 GCH14g 5.0 5.0 5.0 5.0 5.0METHYL ETHYL KETONEGLOSS excellent excellent excellent excellent goodHARDNESS, pencil 2H-3H 2H 2H 2H H-2HADHESION (DRY), % retention 100 100 100 100 30REVERSE IMPACT, in-lbs >180 >180 >180 >180 >180cm-kg >207 >207 >207 >207 >207MEK DOUBLE RUBS >200 >200 >200 >200 >200LOSS OF ADHESION AFTER IMMERSION 39 89 92 47 100FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 0.75" 0.75" 0.75" 0.75" gross(86400 s) (19.05 mm) (19.05 mm) (19.05 mm) (19.05 mm) failure creep creep creep creepEXPOSURE TO QUV FOR 500 HRS low gloss medium medium low gloss flat(1.8 .times. 10.sup.6 s) gloss gloss__________________________________________________________________________ COMP. EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXPT.COMPONENTS & PROPERTIES 21 22 23 24 I__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 13/21.0 14/21.0 15/21.0 16/21.0 --DGEBA SOLUTION, g -- -- -- -- 21.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type V115X70.sup.2 V115X70 V115X70 V115X70 V115X70g 11.5 11.5 11.5 11.5 11.5METHYL ETHYL KETONEGLOSS very good very good fair good very goodHARDNESS, pencil F-H 2H 2H F 2HADHESION (DRY), % retention 100 100 100 100 56REVERSE IMPACT, in-lbs 50 70 60 70 180cm-kg 58 81 69 87 207MEK DOUBLE RUBS >200 >200 >200 >200 <125LOSS OF ADHESION AFTER IMMERSION <5 65 <5 34 100For 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 0.5" 0.5" 0.5" 0.5" 0.5"(86400 s) (12.7 mm) (12.7 mm) (12.7 mm) (12.7 mm) (12.7 mm) creep creep creep creep creepEXPOSURE TO QUV FOR 500 HRS low gloss low gloss low gloss low gloss flat(1.8 .times. 10.sup.6 s)__________________________________________________________________________ COMP. EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXPT.COMPONENTS & PROPERTIES 25 26 27 28 J__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 13/21.0 14/21.0 15/21.0 16/21.0 --DGEBA SOLUTION, g -- -- -- -- 21.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type D.E.H. 29.sup.3 D.E.H. 29 D.E.H. 29 D.E.H. 29 D.E.H. 29g 1.2 1.2 1.2 1.2 1.2METHYL ETHYL KETONEGLOSS excellent excellent excellent excellent very goodHARDNESS, pencil 2H-3H H-2H 2H-3H H-2H H-2HADHESION (DRY), % retention 100 100 100 100 31REVERSE IMPACT, in-lbs 40 70 <20 30 >180MEK DOUBLE RUBS >200 >200 >200 >200 >200LOSS OF ADHESION AFTER IMMERSION 10 100 100 100 100FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 1" 1" 1" 1" gross(86400 s) (25.4 mm) (25.4 mm) (25.4 mm) (25.4 mm) failure creep creep creep creepEXPOSURE TO QUV FOR 500 HRS low gloss low gloss very low low gloss flat(1.8 .times. 10 s) gloss__________________________________________________________________________ .sup.1 Curing agent GCH14 was a polyamide having an amine hydrogen equivalent weight of about 175 available from General Mills as Versamid 114. .sup.2 Curing agent V115X70 was a polyamide having an amine hydrogen equivalent weight of about 375 available from General Mills as VERSAMIDE .RTM. 115X70. .sup.3 D.E.H. .RTM. 29 was a polyamine having an amine hydrogen equivalen weight of about 29 available from The Dow Chemical Company.

EXAMPLES 28-31

Employing the procedure for Example 1, various compositions were prepared. The components and characteristics are given in Table VII.

In this series of copolymers the molecular weight of the diglycidyl ether resin was increased until gellation of the copolymer solution occurred. The highest molecular-weight diglycidyl ether that could be used was about 760.

TABLE VII__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLE 28 29 30 31__________________________________________________________________________COMPONENTSEPOXY RESIN.sup.1, g/equiv. 425/2.35 498.1/2.25 548.9/1.95 610.6/1.60, EEW 181 221 281 381METHACRYLIC ACID, g/equiv. 58/.674 52.2/.607 45.2/.526 37.1/.431ACID/EPOXY EQUIV. RATIO .287 .270 .270 .2691% P-METHOXYPHENOL IN METHYL 6.0 6.5 7.0 7.6AMYL KETONE, gETHYLTRIPHENYLPHOSPHONIUM 0.77 0.84 0.89 1.00ACETATE.ACETIC ACID COMPLEX, gn-BUTYL ACRYLATE, g 167.5 150.8 130.7 107.2METHYL METHACRYLATE, g 206.3 183.4 158.9 130.4t-BUTYL PERBENZOATE, g/mole %.sup.2 23.4/2.89 21.1/2.92 18.3/2.92 15/2.92METHYL AMYL KETONE, g 375 376 377 370PROPERTIESSOLUTION VISCOSITY, cps 427 665 1100 3790% NON-VOLATILES 68.8 68.5 68.2 68.0MOLECULAR WEIGHT OF THE COPOLYMER--M.sub.w 1.2 .times. 10.sub.4 1 .times. 10.sup.4 1.1 .times. 10.sup.4 1.5 .times. 10.sup.4--M.sub.n 5.22 .times. 10.sup.3 5.4 .times. 10.sup.3 4.91 .times. 10.sup.3 5.67 .times. 10.sup.3ACRYLIC/EPOXY, wt. % 50/50 45/55 39/61 32/68( .sup.-f).sub.n of acrylic copolymer 3.5 3.6 2.5 3.0(.sup.--X).sub.n of acrylic copolymer 0.6 0.7 0.5 0.6EEW (total solids basis) 509 577 685 810__________________________________________________________________________ .sup.2 See Table III.

EXAMPLES 32-43

Employing the procedure for Examples 2-4, coatings were prepared from the epoxy-containing polymers prepared in Examples 28-31. Methyl ethyl ketone was added to each formulation in a quantity sufficient to provide the coating with a viscosity of 125-140 cps. The formulation and results are given in Table VIII.

It is noteworthy that when the EEW of the copolymer resin (total resin solids) passes from 685 to 810 a sharp deterioration in several properties is observed; viz., gloss retention, solvent resistance, and salt-fog resistance. An EEW less than about 700, and preferably less than about 600, is therefore desirable.

TABLE VIII__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLECOMPONENTS & PROPERTIES 32 33 34 35__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 9/20.7 10/23.5 11/27.9 12/33METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type GCH14.sup.1 GCH14 GCH14 GCH14g 5.0 5.0 5.0 5.0GLOSS excellent excellent excellent excellentHARDNESS, pencil 2H 2H 2H-3H 2HADHESION (DRY), % retention 100 100 100 100REVERSE IMPACT, in-lbs 150 >180 >180 >180cm-kg 173 >207 >207 >207MEK DOUBLE RUBS >200 >200 >200 100LOSS OF ADHESION AFTER IMMERSION 92 100 100 100FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 0.75" 0.5" 1" 1"(86400 s) (19.05 mm) (12.7 mm) (25.4 mm) (25.4 mm) creep creep creep creepEXPOSURE TO QUV FOR 500 HRS fair fair fair low(1.8 .times. 10.sup.6 s) gloss gloss gloss gloss__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLECOMPONENTS & PROPERTIES 36 37 38 39__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 9/20.7 10/23.5 11/27.9 12/33.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type V115X70.sup.2 V115X70 V115X70 V115X70g 11.5 11.5 11.5 11.5GLOSS fair excellent excellent excellentHARDNESS, pencil 2H H H HADHESION (DRY), % retention 100 100 100 100REVERSE IMPACT, in-lbs 60 >180 >180 >180cm-kg 69 >207 >207 >207MEK DOUBLE RUBS >200 >200 200 100LOSS OF ADHESION AFTER IMMERSION <5 10 <5 97FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 0.5" 0.5" 0.75" 1"(86400 s) (12.7 mm) (12.7 mm) (19.05 mm) (25.4 mm) creep creep creep creepEXPOSURE TO QUV FOR 500 HRS low fair low good(1.8 .times. 10.sup.6 s) gloss gloss gloss gloss__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLECOMPONENTS & PROPERTIES 40 41 42 43__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 9/20.7 10/23.5 11/27.9 12/33.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type D.E.H. .RTM. 29.sup.3 D.E.H. .RTM. 29 D.E.H. .RTM. 29 D.E.H. .RTM. 29g 1.2 1.2 1.2 1.2GLOSS excellent excellent excellent excellentHARDNESS, pencil 2H-3H 3H 2H-3H 2HADHESION (DRY), % retention 100 100 100 100REVERSE IMPACT, in-lbs <20 110 130 >180cm-kg <23 127 150 >207MEK DOUBLE RUBS >200 >200 190 175LOSS OF ADHESION AFTER IMMERSION 100 100 100 100FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 1" 1" 1" gross(86400 s) (25.4 mm) (25.4 mm) (25.4 mm) failure creep creep creepEXPOSURE TO QUV FOR 500 HRS low fair good low(1.8 .times. 10.sup.6 s) gloss gloss gloss gloss__________________________________________________________________________ .sup.1 Curing agent GCH14 was a polyamide having an amine hydrogen equivalent weight of about 175 available from General Mills as Versamid 140. .sup.2 Curing agent V115X70 was a polyamide having an amine hydrogen equivalent weight of about 375 available from General Mills as VERSAMIDE .RTM. 115X70. .sup.3 D.E.H. .RTM. 29 was a polyamine having an amine hydrogen equivalen weight of about 29 available from The Dow Chemical Company.

EXAMPLES 44-48

Employing the procedure of Example 1, various compositions were prepared. The components and characteristics are given in Table IX.

The purpose of this series of copolymers was the demonstration of film improvements by incorporation of an hydroxyl-functional vinyl monomer into the copolymer.

TABLE IX__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLE 44 45 46 47 48__________________________________________________________________________COMPONENTSEPOXY RESIN.sup.1, g/equiv. 1200/6.63 400/2.21 400/2.21 400/2.21 400/2.21METHACRYLIC ACID, g/equiv. 153.5/1.78 51.2/.60 51.2/.60 51.2/.60 51.2/.60ACID/EPOXY EQUIV. RATIO .269 .269 .269 .269 .2691% PHENOTHIAZINE IN METHYL 28.1 9.4 9.4 9.4 9.4AMYL KETONE, gETHYLTRIPHENYLPHOSPHONIUM 2.5 0.83 0.83 0.83 0.83ACETATE.ACETIC ACID COMPLEX, gn-BUTYL ACRYLATE, g 493 154 144 123 82STYRENE, g 597 199 199 199 1992-HYDROXYPROPYL ACRYLATE, g 0 10.3 20.6 41.2 82.4t-BUTYL PERBENZOATE, g/mole %.sup.2 65.9/2.88 22.0/2.89 22.0/2.89 22.0/2.90 22.0/2.91METHYL AMYL KETONE, g 1040 343 343 343 343PROPERTIESSOLUTION VISCOSITY, cps 822 1130 1180 1410 2030% NON-VOLATILES 70.5 70 70 70 70MOLECULAR WEIGHT OF THE COPOLYMER--M.sub.w 1.2 .times. 10.sup.4 2.2 .times. 10.sup.4 1.9 .times. 10.sup.4 2.3 .times. 10.sup.4 2.1 .times. 10.sup.4--M.sub.n 7.15 .times. 10.sup.3 8.78 .times. 10.sup.3 8.49 .times. 10.sup.3 8.53 .times. 10.sup.3 8.79 .times. 10.sup.3ACRYLIC/EPOXY, wt. % 52/48 52/48 52/48 52/48 52/48(.sup.-f).sub.n of acrylic copolymer 3.4 4.2 4.2 4.2 4.2(.sup.--X).sub.n of acrylic copolymer 0.7 0.8 0.8 0.8 0.8EEW (total solids basis) 560 568 565 560 575__________________________________________________________________________ .sup.1 The epoxy resin was a diglycidyl ether of bisphenol A having an average EEW of 181. .sup.2 See Table III.

EXAMPLES 49-63

Employing the procedure of Examples 2-4, coatings were prepared from the epoxy-containing polymers prepared in Table IX. Methyl ethyl ketone was added to each formulation in a quantity sufficient to provide the coating with a viscosity of 125-140 cps. The results are given in Table X.

In this series progressively larger amounts of 2-hydroxypropyl acrylate were substituted for n-butyl acrylate in the vinyl monomer recipe to improve copolymer resin/hardener compatibility. The results are improved dry-film clarity and gloss and reduced surface oiliness, if the 2-hydroxypropyl acrylate weight concentration in the vinyl monomers recipe exceeds about ten percent.

TABLE X__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLECOMPONENTS & PROPERTIES 49 50 51 52 53__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 44/21.0 45/21.0 46/21.0 47/21.0 48/21.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type GCH14.sup.1 GCH14 GCH14 GCH14 GCH14g 5.0 5.0 5.0 5.0 5.0GLOSS good excellent excellent excellent excellentHARDNESS, pencil H H H 2H HADHESION (DRY), % retention 100 100 100 100 100REVERSE IMPACT, in-lbs 180 >180 180 180 180cm-kg 207 >207 207 207 207MEK DOUBLE RUBS >200 >200 >200 >200 >200LOSS OF ADHESION AFTER IMMERSION 61 86 86 96 44FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS0.75" 0.75" 0.75" 0.5" 0.75"(86400 s) (19.05 mm) (19.05 mm) (19.05 mm) (12.7 mm) (19.05 mm) creep creep creep creep creepEXPOSURE TO QUV FOR 500 HRS medium medium medium low medium(1.8 .times. 10.sup.6 s) gloss gloss gloss gloss glossFILM CLARITY clear clear clear clear clearFILM SURFACE OILINESS oily slightly none none none oily__________________________________________________________________________ EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLECOMPONENTS & PROPERTIES 54 55 56 57 58__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 44/21.0 45/21.0 46/21.0 47/21.0 48/21.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type V115X70.sup.2 V115X70 V115X70 V115X70 V115X70g 11.5 11.5 11.5 11.5 11.5GLOSS excellent excellent excellent excellent excellentHARDNESS, pencil H F-H 2H F H-2HADHESION (DRY), % retention 100 100 100 100 100REVERSE IMPACT, in-lbs 30 50 80 110 120cm-kg 35 58 92 127 138MEK DOUBLE RUBS 100 >200 100 100 150LOSS OF ADHESION AFTER IMMERSION 10 <5 32 32 55FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 1" 0.5" gross 0.75" 0.5"(86400 s) (25.4 mm) (12.7 mm) failure (19.05 mm) (12.7 mm) creep creep creep creepEXPOSURE TO QUV FOR 500 HRS low gloss low gloss lost low gloss medium(1.8 .times. 10.sup.6 s) glossFILM CLARITY cloudy clear clear clear clearFILM SURFACE OILINESS oily slightly none none none oily__________________________________________________________________________EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLECOMPONENTS & PROPERTIES 59 60 61 62 63__________________________________________________________________________COPOLYMER SOLUTION, EX. NO./g 44/21.0 45/21.0 46/21.0 47/21.0 48/21.0METHYL ETHER OF PROPYLENE 5.0 5.0 5.0 5.0 5.0GLYCOL, gCURING AGENT, type D.E.H. .RTM. 29.sup.3 D.E.H. .RTM. 29 D.E.H. .RTM. 29 D.E.H. .RTM. 29 D.E.H. .RTM. 29g 1.2 1.2 1.2 1.2 1.2GLOSS good good excellent excellent excellentHARDNESS, pencil H-2H H-2H 2H 2H 2HADHESION (DRY), % retention 100 100 100 100 100REVERSE IMPACT, in-lbs <20 <20 <20 <20 <20cm-kg <23 <23 <23 <23 <23MEK DOUBLE RUBS >200 >200 >200 >200 >200LOSS OF ADHESION AFTER IMMERSION 100 100 100 100 100FOR 1 HOUR (3600 s) IN BOILINGWATER, %SALT-FOG EXPOSURE FOR 24 HOURS 1" 1" 1" gross gross(86400 s) (25.4 mm) (25.4 mm) (25.4 mm) failure failure creep creep creepEXPOSURE TO QUV FOR 500 HRS medium medium medium medium medium-(1.8 .times. 10.sup.6 s) gloss gloss gloss gloss good glossFILM CLARITY faint clear clear clear clear hazeFILM SURFACE OILINESS oily oily faint none none__________________________________________________________________________ .sup.1 Curing agent GCH14 was a polyamide having an amine hydrogen equivalent weight of about 175 available from General Mills as Versamid 140. .sup.2 Curing agent V115X70 was a polyamide having an amine hydrogen equivalent weight of about 375 available from General Mills as VERSAMIDE .RTM. 115X70. .sup.3 D.E.H. .RTM. 29 was a polyamide having an amine hydrogen equivalen weight of about 29 available from The Dow Chemical Company.

EXAMPLES 64-66 AND COMP. EXPT. J

The procedure of Example 1 was employed in preparing the epoxy-containing polymers except that the polymerization temperature was varied. The components and results are given in Table XI.

Higher temperatures are seen to yield copolymers of narrower molecular weight distribution (M.sub.w /M.sub.n), a desirable property. A temperature of about 135.degree. C. is the lowest practical.

TABLE XI__________________________________________________________________________ COMP. EXAMPLE EXAMPLE EXAMPLE EXPT. 64 65 66 J__________________________________________________________________________COMPONENTSEPOXY RESIN.sup.1, g/equiv. 485.7/2.68 485.7/2.68 485.7/2.68 485.7/2.68METHACRYLIC ACID, g/equiv. 80/.93 80/.93 80/.93 80/.93ACID/EPOXY EQUIV. RATIO .347 .347 .347 .3471% p-METHOXYPHENOL IN METHYLAMYL KETONE, g 6.6 6.6 6.6 6.6ETHYLTRIPHENYLPHOSPHONIUMACETATE .multidot.ACETIC ACID COMPLEX, g 0.85 0.85 0.85 0.85n-BUTYL ACRYLATE, g 188 188 188 188METHYL METHACRYLATE, g 217.7 217.7 217.7 217.7t-BUTYL PERBENZOATE, g/mole %.sup.2 14.0/3.15 14.0/3.15 14.0/3.15 14.0/3.15METHYL AMYL KETONE, g 342 342 342 342POLYMERIZATION TEMPERATURE, .degree.C. 148 143 138 133PROPERTIESSOLUTION VISCOSITY, cps 2110 4370 20900 gelled% NON-VOLATILES 70 70 70 --MOLECULAR WEIGHT OF THE COPOLYMER--M.sub.w 5.0 .times. 10.sup.4 1.3 .times. 10.sup.5 3.0 .times. 10.sup.5 -- --M.sub.n 7.42 .times. 10.sup.3 8.87 .times. 10.sup.3 8.82 .times. 10.sup.3 --ACRYLIC/EPOXY, wt. % 51/49 51/49 51/49 --.sup.-f.sub.n of acrylic copolymer 4.9 5.9 5.9 --.sup.--X.sub.n of acrylic copolymer 1.3 1.6 1.6 --EEW (total solids basis) 592 595 587 --__________________________________________________________________________ .sup.1 The epoxy resin was a diglycidyl ether of bisphenol A having an average EEW of 181. .sup.2 See Table III.

EXAMPLE 67

The epoxy-methacrylic acid reaction was conducted as in Example 1. Then, this was mixed with the monomers and the mixture was fed over a period of 4 hours and 10 minutes (15000 s) at a solvent temperature of 120.degree. C. The mixture was then stirred at 120.degree. C. for an additional two hours (7200 s) to complete the polymerization. The composition and properties are given in the following Table XII.

This copolymer was prepared to illustrate the incorporation of additional epoxy functionality into the copolymer (the use of glycidyl methacrylate) and the use of a different solvent and a different polymerization initiator.

TABLE XII______________________________________ EXAMPLE 67______________________________________COMPONENTSEPOXY RESIN.sup.1,g/equiv. 240/1.326METHACRYLIC ACID, g/equiv. 30.7/.357ACID/EPOXY EQUIV. RATIO .2691% p-METHOXYPHENOL IN METHYL 7.2AMYL KETONE, gETHYLTRIPHENYLPHOSPHONIUM 0.50ACETATE.multidot.ACETIC ACID COMPLEX, gn-BUTYL ACRYLATE, g 137.3GLYCIDYL METHACRYLATE 72.0n-DODECANE-1-THIOL 1.21-TERT-BUTYLAZO-1-CYANOCYCLO- 14.9/2.85HEXANE g/mole %.sup.2METHYL ETHER OF PROPYLENE 284GLYCOLPROPERTIESSOLUTION VISCOSITY, cps not determined% NON-VOLATILES 62MOLECULAR WEIGHT OFTHE COPOLYMER--M.sub.w 1.10 .times. 10.sup.4--M.sub.n 5.14 .times. 10.sup.3ACRYLIC/EPOXY, wt. %.sup.-f.sub.n of acrylic copolymer 3.7.sup.--X.sub.n of acrylic copolymer 0.7EEW (total solids basis) 359______________________________________ .sup.1 The epoxy resin was a diglycidyl ether of bisphenol A having an average EEW of 181. .sup.2 See Table III.

EXAMPLES 68-69

The procedure of Example 1 was employed using various epoxy resins. The components and results are given in the following Table XIII.

Both resins gave good coatings when cured with a polyamide.

TABLE XIII__________________________________________________________________________ EXAMPLE EXAMPLE 68 69__________________________________________________________________________COMPONENTSEPOXY RESIN.sup.1, g/equiv. 237.sup.1 /1.43 511.3.sup.2 /2.86METHACRYLIC ACID, g/equiv. 24.6/.286 49.2/.572ACID/EPOXY EQUIV. RATIO .200 .2001% PHENOTHIAZINE IN METHYL 10.0 --AMYL KETONE, g1% HYDROQUINONE IN METHYL -- 40.0AMYL KETONE, gETHYLTRIPHENYLPHOSPHONIUM 0.50 1.37ACETATE.multidot.ACETIC ACID COMPLEX, gSEC-BUTYL ACRYLATE, g 133 --n-BUTYL ACRYLATE, g -- 270.5STYRENE, g 84.8 --METHYL METHACRYLATE, g -- 191.6t-BUTYL PERBENZOATE, g/mole %.sup.2 12.4/2.90 27.4/2.98METHYL AMYL KETONE, g 200 411PROPERTIESSOLUTION VISCOSITY, cps 2790 2430% NON-VOLATILES 68.7 69MOLECULAR WEIGHT OF THE COPOLYMER--M.sub.w 1.16 .times. 10.sup.4 2.9 .times. 10.sup.4--M.sub.n 8.17 .times. 10.sup.3 6.06 .times. 10.sup.3ACRYLIC/EPOXY, wt. %(.sup.-f).sub.n of acrylic copolymer 9.0 .about.8(.sup.--X).sub.n of acrylic copolymer 2.4 .about.2EEW (total solids basis) not det. not det.__________________________________________________________________________ .sup.1 The epoxy resin was the triglycidyl ether of tris(4hydroxyphenyl)methane having an average EEW of 166. .sup.2 The epoxy resin was the glycidyl ether of a phenolformaldehyde novolac resin having an average epoxy functionality of about 3.5 and an average EEW of about 179.

EXAMPLE 70

A copolymer was prepared exactly as in Example 47, Table IX, except that, instead of 41.2 gm of 2-hydroxypropyl acrylate, 45.6 gm of 2-hydroxybutyl acrylate was used as part of the vinyl monomer mixture. The resulting copolymer solution had the following properties.

______________________________________Solution viscosity, cps 779% Non-volatiles 68Mol. Wt. of the Copolymer--M.sub.w 1.74 .times. 10.sup.4--M.sub.n 7.15 .times. 10.sup.3Acrylic/Epoxy, wt. % 52/48(.sup.-f).sub.n of acrylic copolymer 3.5(-x).sub.n of acrylic copolymer 0.8EEW (total solids basis) 576______________________________________

The copolymers of Examples 47 and 70 were made into white enamels for use with polyamide curing agents as shown below. Also included was a conventional bisphenol A diglycidyl ether known as DER.RTM.671, for comparative purposes.

______________________________________ENAMEL RECIPE Resins of Conventional This Invention.sup.1 Epoxy Resin.sup.2______________________________________Pigment GrindEpoxy Resin 180.0 gm 168.0 gmSolutionTiPure .RTM. R-960 172.8 gm 172.8 gmTiO.sub.2Diluentmethyl ethyl ketone sufficient to reduce the vis- cosity of the enamels to 300 cps.______________________________________ .sup.1 at 70% solids .sup.2 at 75% solids in methyl ibutyl ketone The pigment was dispersed in the epoxy resin solution by grinding the mixture for ten minutes (600 s) on a Cowles high-shear disperser.

To each enamel was added a solution of 18.0 gm of Versamid.RTM.1540 in 22.0 gm of Dowanol.RTM.PM glycol ether solvent. After thorough mixing, the enamels were allowed to stand for 1.0 hours (3600 s) at 25.degree. C., then sprayed onto 24 gauge unpolished cold-rolled steel, 24 gauge phosphatized steel (Bonderite.RTM.40), and aluminum Q panels. The coatings were allowed to harden for one week at 25.degree. C. The enamels were designated as follows:

Enamel based on 2-hydroxypropyl acrylate--I-A Enamel based on 2-hydroxybutyl acrylate--I-B Enamel based on conventional epoxy resin--I-C

In the same way, two more enamels were made for use with a different polyamide hardener, Versamid.RTM.115. In this case, only the experimental copolymer based on 2-hydroxypropyl acrylate was used.

______________________________________ENAMEL RECIPE Resins of Conventional This Invention Epoxy Resin______________________________________Pigment GrindEpoxy Resin 170.0 gm 158.7 gmSolutionTiPure .RTM. R-960 214.0 gm 214.0 gmTiO.sub.2Diluentmethyl ethyl ketone sufficient to reduce the vis- cosity of the enamels to 300 cps.______________________________________ To each of these enamels was added a solution of 59.5 gm of Versamid.RTM.115 dissolved in 50.0 gm of Dowanol.RTM.PM glycol ether and 26.9 gm of methyl ethyl ketone, with aging and spraying as before. Enamel designations were as follows. Enamel based on 2-hydroxypropyl acrylate--IA Enamel based on conventional epoxy resin--IIC

The five enamels at spraying had the properties shown in Table XIV.

TABLE XIV______________________________________ Value Property in EnamelEnamel Property IA IB IC IIA IIC______________________________________color white white white white whiteviscosity, cps .about.300 .about.300 .about.300 .about.300 .about.300% non-volatiles 72 71 66 65 67pigment/binder 1.20 1.20 1.20 1.20 1.20resin/hardener 7.0 7.0 7.0 2.0 2.0______________________________________ After curing for one week at 25.degree. C., the coated panels were evaluated as shown in Tables XV, XVI and XVII. TABLE XV__________________________________________________________________________Cured Coating Properties Over 24-GuageUnpolished Cold-Rolled Steel Value Obtained with EnamelCoating Property IA IB IC IIA IIC__________________________________________________________________________60.degree. Gloss, % 95 99 93 79 95SURFACE OILINESS none none none none noneIMPACT, FORWARD.sup.1 15 15 28 40 90IMPACT, REVERSE.sup.1 <2 <2 <2 <20 30ADHESION, %.sup.2 100 97 99 99 95MEK DOUBLE-RUBS.sup.3 200 135 >200 >200 >2001/8 in. (3.175 mm) conical 1/4" 1/8" 1/8" <1/16" <1/16"mandrel bend.sup.4 (6.35 mm) (3.175 mm) (3.175 mm) (1.5875 mm) (1.5875 mm)DRY-FILM THICKNESS,mils 2-21/2 3-31/2 3-31/2 21/2-3 2mm 0.0508- 0.0762- 0.0762- 0.0635- 0.0508 0.0635 0.0889 0.0889 0.0762__________________________________________________________________________ .sup.1 Gardner impactor, inchlbs. .sup.2 1.5 mil (0.0381 mm) crosshatch with tapepull .sup.3 to substrate .sup.4 length of crack at narrow end of bend TABLE XVI______________________________________CURED COATING CORROSION-RESISTANCE.sup. 1 OVER24-GUAGE BONDERITE .RTM. 40Coating Value Obtained with EnamelProperty IA IB IC IIA IIB______________________________________creep fromscribe.sup. 2 3 days <1/32" <1/32" <1/32" <1/32" <1/32"(259200 s) 7 days 1/32" 1/32" 1/32" 1/32" 1/32"(604800 s)21 days 1/4-3/8" 3/32" 1/2" 1/4" 1/4"(1814400 s)42 days 1/4-3/8" 1/8" >1" 3/4" 1/8"(3628800 s)fieldrusting 3 days none none slight none none(259200 s) 7 days none none severe none none(604800 s)21 days none none severe none none(1814400 s)42 days none none severe none none(3628800 s)blisters 3 days none none many none none(259200 s) fine 7 days none none many none none(604800 s) fine21 days none none many few none(1814400 s) fine medium42 days few none many few few(3628800 s) small medium medium small______________________________________ .sup.1 5% saltfog at 95.degree. F. for 1000 hours .sup.2 1/32" = 0.79375 mm; 1/4" = 6.35 mm; 3/4" = 19.05 mm; 1/16" = 1.587 mm 3/8" = 9.525 mm; 1" = 25.4 mm; 1/8" = 3.175 mm; 1/2" = 12.7 mm? TABLE XVII______________________________________Cured Coating Resistance to Dulling and Chalking inthe QUV.sup.1 .RTM. Over Aluminum Q-Panels Value Obtained with EnamelProperty IA IB IC IIA IIB______________________________________60.degree. GLOSS AFTER 0 days 95 98 94 80 97 3 days (259200 s) 75 86 29 58 67 7 days (604800 s) 41 78 7 20 1914 days (1209600 s) 15 30 6* 8 12*21 days (1814400 s) 31 24* 5 5 728 days (2419200 s) 12* 21 3 5* 535 days (3024000 s) 11 19 3 7 --42 days (3628800 s) -- 15 -- 6 --______________________________________ *onset of chalking .sup.1 light/moisture cycle was 8.0 hours of light at 140.degree. F. (60.degree. C.) and 4.0 hours of moisture at 125.degree. F. (51.7.degree. C.).?

EXAMPLE 71

A copolymer was prepared exactly as in Example 47, Table IX, except that 41.2 gm of 2-hydroxyethyl methacrylate was used in place of 41.2 gm of 2-hydroxypropyl acrylate. The resulting copolymer solution had the following properties.

______________________________________solution viscosity, cps 1500% non-volatiles 69.7mol. wt. of the copolymer--M.sub.w 20,000--M.sub.n 7,300acrylic/epoxy, wt. % 52/48(.sup.-f).sub.n of acrylic polymer 3.7(-X).sub.n of acrylic polymer 0.9EEW (total solids basis) 562______________________________________

The resin was made into an enamel for use with Versamid.RTM.1540 and sprayed on metal panels as in Example 70. Cured coating properties are shown below in Tables XVII-XIX. The experimental enamel is designated as III-B and DER.RTM.671 control enamel as III-C.

TABLE XVIII______________________________________Cured Coating Properties Over 24-GuageUnpolished Cold-Rolled SteelCoating Property III-B III-C______________________________________60.degree. GLOSS, % 89 93SURFACE OILINESS none noneIMPACT, FORWARD 15 28IMPACT, REVERSE <2 <2ADHESION, % 99 99MEK DOUBLE-RUBS >200 >2001/8" (3.175 mm) 1/2" (12.7 mm) <1/16"MANDREL BEND crack (1.5875 mm) crackDRY FILM THICKNESS,mils 3-31/2 3-31/2mm 0.0762-0.0889 0.0762-0.0889______________________________________ TABLE XIX______________________________________Cured Coating Corrosion-Resistance Over 24-GuageBonderite .RTM. 40 Value Obtained with EnamelCoating Property III-B III-C______________________________________creep from scribe 3 days(259200 s) <1/32" (0.79375 mm) <1/32" (0.79375 mm) 7 days(604800 s) <1/32" (0.79375 mm) 1/32" (0.79375 mm)21 days(1814400 s) 0-1/4" (0-6.35 mm) 1/2" (12.7 mm)42 days(3628800 s) 1/4-3/8" >1" (25.4 mm) (6.35-9.525 mm)field rusting 3 days(259200 s) none slight 7 days(604800 s) none severe21 days(1814400 s) none severe42 days(3628800 s) none severeblisters 3 days(259200 s) none many fine 7 days(604800 s) none many fine21 days(1814400 s) none many fine42 days(3628800 s) none many medium______________________________________ TABLE XX______________________________________Cured Coating Resistance to Dulling andChalking in the QUV .RTM. OverAluminum Q Panels Value Obtained with EnamelProperty III-B III-C______________________________________60.degree. gloss after0 days 92 943 days (259200 s) 61 297 days (6048800 s) 29 714 days (1209600 s) 12 6*21 days (1814400 s) 11 528 days (2419200 s) 9* 335 days (3024000 s) 8 342 days (3628800 s) -- --______________________________________ *onset of chalking

EXAMPLE 72

A copolymer was prepared exactly as in Example 47, Table IX, except that the methacrylic acid was first copolymerized with the other vinyl monomers, then this carboxylated copolymer solution was coupled to the bisphenol A diglycidyl ether resin. A comparison of the properties of the two products is given in Table XXI.

TABLE XXI______________________________________Comparison of Two Identical CopolymersMade by Different Procedures Value Obtained with Copolymer ofCopolymer Property Example 47 Example 72______________________________________appearance clear, amber clear, amber% non-volatiles 70 69.1solution viscosity 1410 cps 2720 cpsmol. wt. of vinyl copolymer--M.sub.w 23,000 72,500--M.sub.n 8,530 9,530EEW, liquid basis 800 732EEW, solids basis 560 506(.sup.-f).sub.n of the copolymer 3.4 4.2(-X).sub.n of the copolymer 0.8 1.0______________________________________

The much higher ratio M.sub.w /Mn in Example 72 results in a doubling of the viscosity (undesirable) with only a slight improvement in copolymer functionality, (f).sub.n.

Claims

1. A solvent soluble epoxy-containing composition which comprises the product obtained by reacting in the presence of a suitable quantity of a suitable vinyl polymerization catalyst so as to effect polymerization

(A) the reaction product obtained by reacting in the presence of a suitable quantity of a suitable catalyst

(1) at least one material having from greater than 1 to about 4 ##STR8## per molecule wherein each R is independently hydrogen or a monovalent hydrocarbon group having from 1 to about 4 carbon atoms; X is --O--, --S-- or ##STR9## and wherein said material has an epoxide equivalent weight of from about 150 to about 400; and

(2) at least one of acrylic acid or methacrylic acid;

wherein components (1) and (2) are present in a quantity which provides an equivalent ratio of acid groups from component (2) to epoxy groups from component (1) of from about 0.1:1 to less than about 0.5:1; and

(B) at least one monomer having at least one polymerizable ethylenically unsaturated group per molecule and which optionally contains a hydroxyl or an epoxide group; and

wherein components (A) and (B) are employed in quantities such that the weight ratio of vinyl monomers to epoxy compound varies from about 0.4:1 to about 2.5:1.

2. An epoxy-containing composition of claim 1 wherein

(i) the equivalent weight of component (A-1) is from about 180 to about 270;

(ii) the ratio of acid groups from component (A-2) to epoxy groups from component (A-1) is from about 0.2:1 to about 0.3:1; and

(iii) components (A) and (B) are employed in quantities such that the weight ratio of vinyl monomers to epoxy compound is from about 0.6:1 to about 3.0:1.

3. An epoxy-containing composition of claim 2 wherein

(i) component (A-1) is a glycidyl ether of an aromatic dihydroxyl-containing compound or a mixture of such glycidyl ethers; and

(ii) component (B) is styrene, n-butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl methacrylate, or a mixture thereof.

4. A curable composition which comprises

(I) an epoxy-containing composition which comprises the product obtained by reacting in the presence of a suitable quantity of a suitable vinyl polymerization catalyst so as to effect polymerization

(A) the reaction product obtained by reacting in the presence of a suitable quantity of a suitable catalyst

(1) at least one material having from greater than 1 to about 4 ##STR10## per molecule wherein each R is independently hydrogen or a monovalent hydrocarbon group having from 1 to about 4 carbon atoms; X is --O--, --S-- or ##STR11## and wherein said material has an epoxide equivalent weight of from about 150 to about 400; and

(2) at least one of acrylic acid or methacrylic acid;

wherein components (1) and (2) are present in a quantity which provides an equivalent ratio of acid groups from component (2) to epoxy groups from component (1) of from about 0.1:1 to about 0.4:1; and

(B) at least one monomer having at least one polymerizable ethylenically unsaturated group per molecule and which optionally contains a hydroxyl or an epoxide group; and

wherein components (A) and (B) are employed in quantities such that the weight ratio of vinyl monomers to epoxy compound is from about 0.4:1 to about 2.5:1;

(II) optionally a suitable quantity of a suitable solvent system for achieving the desired application viscosity; and

(III) an effective quantity of a suitable curing agent and/or catalyst for curing the composition.

5. A curable composition of claim 4 wherein

(i) the equivalent weight of component (I-A-1) is from about 180 to about 270;

(ii) the ratio of acid groups from component (I-A-2) to epoxy groups from component (I-A-1) is from about 0.2:1 to about 0.3:1; and

(iii) components (I-A) and (I-B) are employed in quantities which provide a weight ratio of vinyl monomers to epoxy compound of from about 6:1 to about 1.5:1.

6. A curable composition of claim 5 wherein

(i) component (I-A-1) is a glycidyl ether of an aromatic dihydroxyl-containing compound or a mixture of such glycidyl ethers;

(ii) component (I-B) is styrene, n-butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate or a mixture thereof.