Solution polymerization of acrylic acid derived monomers using tertiary alkyl(ηC5)hydroperoxides

Claim 2

A process for the free-radical polymerization of monomers derived from substituted or unsubstituted acrylic acid or methacrylic acid or esters thereof comprising solution polymerizing said monomers wherein 20-40% by weight of the monomer composition is hydroxyalkyl acrylate or methacrylate in a temperature range of 90°-200° C., in the presence of a solvent suitable for high solids coating application, wherein the solvent to monomer ratio is 3:1 to 0.1:1, and in the presence of an initiating amount of about 0.50 to about 10.0 parts by weight per 100 parts of monomer of a tertiary-alkyl hydroperoxide and/or its derivative having a one hour half-life temperature in the range of 50°-190° C. and having at least 5 carbons in the tertiary alkyl component, said derivatives being selected from peroxyketals, dialkyl peroxides, peroxyesters, and monoperoxycarbonates, wherein the initiators and monomers, alone or in combination, are added over a period of at least about 3 hours at a controlled rate wherein the rate of addition corresponds approximately to the rate of decomposition of said monomer and initiator.

Claim 3

The process of claim 1 wherein the tertiary-alkyl hydroperoxide and/or its derivative is selected from the class of (ROO) n R 1 where n is 1 or 2, and when n is 1, R is selected from t-alkyl of 5-20 carbons, t-cycloalkyl of 6-20 carbons, and ##STR7## R 2 is selected from lower alkyl of 1-6 carbons, R 3 is selected from alkyl of 2-6 carbons, and Ar is selected from aryl of 6-12 carbons, and R 1 is independently selected from R, hydrogen, acyl of 2-18 carbons, aroyl of 7-18 carbons, or alkoxycarbonyl of 2-19 carbons, and when n is 2, R 1 is selected from di-tertiary-alkylene of 7-20 carbons, di-tertiary alkynylene of 8-20 carbons, di-t-cycloalkylene of 12-20 carbons, and ##STR8## where R 2 is as defined above and Ar' is selected from arylene of 6-12 carbons, ##STR9## where R 4 and R 5 are the same or different, alkyl of 1-10 carbons, cycloalkyl of 5-10 carbons, cycloalkenyl of 5-10 carbons, or aralkyl of 7-10 carbons, and R 4 and R 5 can join together to form an alkylene diradical of 5-11 carbons, ##STR10## where R 6 is selected from alkylene of 1-20 carbons, cycloalkylene of 5-12 carbons, arylene of 6-12 carbons, ##STR11## where R 7 is selected from alkylene of 2-20 carbons and cycloalkylene of 5-12 carbons, and R is selected from the same groups mentioned above when n=1 and also can be hydrogen, acyl of 2-18 carbons, aroyl of 7-18 carbons, or alkoxycarbonyl of 2-19 carbons when R 1 is selected from di-t-alkylene, di-t-alkynylene, di-t-cycloalkylene, or ##STR12## wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , Ar, and Ar' can optionally be substituted, wherein the substituents can be one or more of lower alkyl of 1-4 carbon, cycloalkyl of 5-12 carbons, halo, carboxy, hydroxy, lower acyloxy of 1-4 carbons, epoxy, lower alkoxy of 1-4 carbons, aryloxy of 6-12 carbons, lower alkoxycarbonyl of 1-4 carbons, carbamoyl, mono and di lower alkyl carbamoyl of 1-4 carbons, and dicarboximido of 4-12 carbons, and Ar', R 6 , R 7 and when R 4 and R 5 join together to form an alkylene diradical can optionally contain one or more oxygen or nitrogen.

Claim 4

The process of claim 2 wherein the tertiary-alkyl hydroperoxide derivative is selected from tertiary-amyl peroctoate, di-tertiary-amyl diperoxyazelate, di-tertiary-amyl peroxide, 1,1-di(t-amylperoxy)cyclohexane, di-(t-octylperoxy)propane, tertiary-octyl hydroperoxide, 2,2-di-(t-amylperoxy)butane, and ethyl 3,3-di(t-amylperoxy)butyrate.

Claim 5

The process of claim 3 wherein the monomers are selected from the group consisting of acrylic acid, methacrylic acid, methyl methacrylate, isobutyl methacrylate, butyl acrylate, butyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, styrene, para-methyl styrene, and mixtures thereof.

Claim 6

The process of claim 4 wherein the monomers are by weight of monomer composition 30% methyl methacrylate, 40% isobutyl methacrylate, and 30% hydroxyethyl methacrylate.

Claim 7

The process of claim 4 wherein the monomers are by weight of monomer composition 10-30% styrene, 30-60% isobutyl methacrylate, and 20-40% hydroxyethyl methacrylate.

Claim 8

The process of claim 4 wherein the monomers are by weight of monomer composition 30% para-methyl styrene, 40% isobutyl methacrylate, and 30% hydroxyethyl methacrylate.

Claim 9

The process of claim 4 wherein the monomers are by weight of monomer composition 30% styrene, 30% butyl acrylate, 20% butyl methacrylate, and 20% 2-hydroxyethyl acrylate.

Claim 10

The process of claim 4 wherein the solvent is selected from the group consisting of toluene, xylene, ethyl acetate, acetone, methyl ethyl ketone, methyl n-amyl ketone, ethyl alcohol, benzyl alcohol, oxo-hexyl acetate, oxo-heptyl acetate, propylene glycol methyl ether acetate and mineral spirits.

Claim 11

The process of claim 1 wherein a combination of two or more initiators are used wherein at least one is a tertiary-alkyl (≧C 5 ) hydroperoxide and/or its derivative.