High solid coatings

Claim 2

An improved process for forming high solids acrylic copolymer resins suitable for electrostatic spraying which comprises contacting under polymerizing conditions at least one hydroxy-substituted alkyl (meth)acrylate monomer and at least one non-hydroxy substituted alkyl (meth)acrylate monomer in the presence of a free radical initiator and a solvent therefor, said solvent comprising at least one normally liquid ester selected from the group consisting of compounds having the formula: wherein R 1 is a straight or branched chain alkyl of 1 to 6 carbon atoms, and R 2 is a straight or branched chain alkyl of 1 to 7 carbon atoms, with the proviso that R 1 and R 2 together contain from 6 toll carbon atoms.

Claim 3

The process of claim 1 wherein said hydroxy-substituted alkyl (meth)acrylate monomer comprises a member selected from the group consisting of monomers of the formula: wherein R 4 is hydrogen or methyl and R 5 and R 6 are independently selected from the group consisting of hydrogen and alkyl of from 1 to 6 carbon atoms.

Claim 4

The process according to claim 1 or claim 2, wherein said non-hydroxy substituted alkyl (meth)acrylate monomer comprises at least one monomer of the formula: wherein R 7 is alkyl of from 1 to 6 carbon atoms and R 8 is hydroxy or methyl.

Claim 5

The process according to any of claims 1 to 3, wherein ester solvent is employed in admixture with at least one alkyl-substituted benzene solvent in which the alkyl substituent(s) contain a total of at least 2 carbon atoms when the benzene ring is monoalkyl substituted and contains a total of at least 3 carbon atoms when the benzene ring is substituted by two or more alkyl groups.

Claim 6

The process according to claim 4 wherein said alkyl-substituted benzene solvent comprises at least 1 aromatic compound of the formula: wherein p is an integer of from 1 to 4, and X is in each instance in which it appears independently selected from the group consisting of straight and branched-chain alkyl of from 1 to 4 carbon atoms, with the proviso that when p is 1, X must contain at least 2 carbon atoms and with the further proviso that when p is 2 or higher, the X groups must contain a total of at least 3 carbon atoms, and mixtures of the foregoing aromatic compounds.

Claim 7

The process according to any of claims 1 to 5, wherein said ester solvent is employed in an amount of from 10 to 70 by weight of the reaction mass in said polymerization reaction.

Claim 8

The process according to any of claims 1 to 6, wherein said hydroxy-substituted alkyl (meth)acrylate monomer is employed in an amount of from 5 to 30 wt.% of the total monomers charged to said polymerization reaction.

Claim 9

The process -according to any of claims 1. to 7, wherein said non-hydroxy substituted alkyl (meth)acrylate monomer- comprises from 5 to 95 wt.% of the total monomers charged to said polymerization reaction.

Claim 10

The process according to any of claim 1 to 8, wherein said polymerization reaction is effected for a time of from 0.5 to 10 hours.

Claim 11

The process according to any of claims 1 to 9, - wherein the acrylic polymer produced in said polymerization reaction is characterized by a weight average molecular weight of from 2,000 to 12,000.

Claim 12

The process according to any of claims 1 to 10, wherein said normally liquid ester solvent comprises an alkyl - acetate having a total of from 5 to 7 carbom atoms in the alkyl moiety, an alkyl proportionate having a total of from 4 to 6 carbon atoms in the alkyl moiety or an alkyl butyrate having a total of from 3 to 5 carbon atoms in the alkyl moiety.

Claim 13

A polymerizable composition comprising a mixture of acrylic resin monomers and from 10 to 70 wt. %. of a solvent comprising at least ane normally liquid ester selected from the group consisting of compounds having the formula: wherein R 1 is a straight or branched chain alkyl of 1 to 6 carbon atoms, and R 2 is a straight or branched chain alkyl of 1 to 7 carbon atoms, with the proviso that R l and R 2 together contain from 6 to 11 carbon atoms.

Claim 14

A polymerizable composition comprising a mixture of acrylic resin monomers and from 10 to 70 wt. %. of a solvent comprising at least ane normally liquid ester selected from the group consisting of compounds having the formula: wherein R 1 is a straight or branched chain alkyl of 1 to 6 carbon atoms, and R 2 is a straight or branched chain alkyl of 1 to 7 carbon atoms, with the proviso that R l and R 2 together contain from 6 to 11 carbon atoms.

Claim 15

A polymerizable composition suitable for application after polymerization to a surface by electrostatic spraying as a high solids coating which comprises (a) from 30 to 90 wt.% of a monomer mixture comprising (i) at least one hydroxy-substituted alkyl (meth)acrylate in an amount of from 5 to 30 wt.% of said monomer mixture; (ii) at least one non-hydroxy substituted alkyl (meth)acrylate monomer in an amount of from 5 to 95 wt.% of said monomer mixture; and (iii) at least one free radical polymerization initiator in an amount of from 0.5 to 6 wt.% of said monomer mixture; and (b) from 10 to 70 wt.% of a polymerization solvent comprising at least one normally liquid ester selected from the group consisting of compounds having the formula: - 'wherein R is a straight or branched chain alkyl of 1 to 6 carbon atoms, and R 2 is a straight or branched chain alkyl of 1 to 7 carbon atoms, with the proviso that R 1 and R 2 together contain from 6 to 11 carbon atoms.

Claim 16

A polymerizable composition suitable for application after polymerization to a surface by electrostatic spraying as a high solids coating which comprises (a) from 30 to 90 wt.% of a monomer mixture comprising (i) at least one hydroxy-substituted alkyl (meth)acrylate in an amount of from 5 to 30 wt.% of said monomer mixture; (ii) at least one non-hydroxy substituted alkyl (meth)acrylate monomer in an amount of from 5 to 95 wt.% of said monomer mixture; and (iii) at least one free radical polymerization initiator in an amount of from 0.5 to 6 wt.% of said monomer mixture; and (b) from 10 to 70 wt.% of a polymerization solvent comprising at least one normally liquid ester selected from the group consisting of compounds having the formula: - 'wherein R is a straight or branched chain alkyl of 1 to 6 carbon atoms, and R 2 is a straight or branched chain alkyl of 1 to 7 carbon atoms, with the proviso that R 1 and R 2 together contain from 6 to 11 carbon atoms.

Claim 17

The polymerizable composition of claim 13 wherein said monomer mixture further comprises from 5 to 30 Wt.% of at least one monovinyl aromatic hydrocarbon containing from 8 to 12 carbon atoms.

Claim 18

Low viscosity acrylic resins, suitable for application as a high solids coating upon a surface by electrostatic spraying, which comprise resins formed by polymerization of from 30 to 90 wt.% of an acrylic monomer mixture in the presence of from 10 to 70 wt.% of a polymerization solvent comprising at least one normally liquid ester selected from the group consisting of compounds having the formula: wherein R 1 is a straight or branched chain alkyl of 1 to 6-carbon atoms, and R 2 is a straight or branched chain alkyl of.l to 7 carbon atoms, with the proviso that R 1 and R2 together contain from 6 to 11 carbon atoms, said acrylic monomer mixture comprising (i) at least one hydroxy-substituted alkyl (meth) acrylate in an amount of from 5 to 30 wt.% of said monomer mixture; (ii) at least one non-hydroxy substituted alkyl (meth)acrylate monomer in an amount of from 5 to 95 wt.% of said monomer mixture; and (iii) at least one free radical polymerization initiator in an amount of from 0.5 to 6 wt.% of said monomer mixture,. said acrylic resin being characterized by weight average molecular weights of from 2,500 to 10,000, by kinemmatic viscosities of up to 6,000 cs and by weight average molecular weight to number average molecular weigh.t ratios of from 1 to 5.

Claim 19

Low viscosity acrylic resins, suitable for application as a high solids coating upon a surface by electrostatic spraying, which comprise resins formed by polymerization of from 30 to 90 wt.% of an acrylic monomer mixture in the presence of from 10 to 70 wt.% of a polymerization solvent comprising at least one normally liquid ester selected from the group consisting of compounds having the formula: wherein R 1 is a straight or branched chain alkyl of 1 to 6-carbon atoms, and R 2 is a straight or branched chain alkyl of.l to 7 carbon atoms, with the proviso that R 1 and R2 together contain from 6 to 11 carbon atoms, said acrylic monomer mixture comprising (i) at least one hydroxy-substituted alkyl (meth) acrylate in an amount of from 5 to 30 wt.% of said monomer mixture; (ii) at least one non-hydroxy substituted alkyl (meth)acrylate monomer in an amount of from 5 to 95 wt.% of said monomer mixture; and (iii) at least one free radical polymerization initiator in an amount of from 0.5 to 6 wt.% of said monomer mixture,. said acrylic resin being characterized by weight average molecular weights of from 2,500 to 10,000, by kinemmatic viscosities of up to 6,000 cs and by weight average molecular weight to number average molecular weigh.t ratios of from 1 to 5.

Claim 20

The low viscosity acrylic resins of claim 15 wherein said acrylic monomer mixture additionally comprises from 5 to 30 wt.% of at least one monovinyl aromatic hydrocarbon containing from 8 to 12 carbon atoms, and either (i) from 2 to 5 wt.% of acrylic acid, or (ii) front 3 to 10 wt.% of at least one member selected from the group consisting of vinylchloride, acrylonitrile, methacrylonitrile and vinyl acetate.

Claim 21

The use as a polymerization solvent in the formation of high solids acrylic copolymer resins suitable for electrostatic spraying of a normally liquid ester of the formula: as defined in claim 1. The use as a polymerization solvent in the formation of high solids acrylic copolymer resins suitable for electrostatic spraying of pentyl acetates. The use as a polymerization solvent in the formation of high solids acrylic copolymer resins suitable for electrostatic spraying of a mixture of 2-methyl-butyl acetate, 3-methyl-butyl acetate and n-pentyl acetate. The use as a polymerization solvent in the formation of high solids acrylic copolymer resins suitable for electrostatic spraying of hexyl acetates. The use as a polymerization solvent in the formation of high solids acrylic copolymer resins suitable for electrostatic spraying of heptyl acetates.