US 4,394,480 AGranted

Low shrinkage unsaturated polyester resin composition

AssigneeNippon Oil and Fats Co., Ltd.

InventorsNorihisa Ujikawa, Kyosuke Fukushi

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Abstract

An unsaturated polyester resin composition comprising an unsaturated polyester resin, a polymerizable monomer and a mixture of block copolymers having acid groups prepared by first copolymerizing in a first copolymerization reaction a polymeric peroxide with a monomer A or B, or with an unsaturated acid together with monomer A or B, thereby obtaining a copolymer having peroxy bonds in the molecule thereof, which copolymer is further copolymerized in the second copolymerization reaction with each of monomers A or B or the unsaturated acid which were excluded in the first copolymerization reaction to give the block copolymer mixture, which composition shows no segregation of the low shrinkage agent on thickening by a thickener and the said composition gives cured moldings of reduced shrinkage which are excellent in many characteristics. Monomer A: a vinyl acetate or a mixture of vinyl acetate and one or more monomers which are copolymerizable with vinyl acetate Monomer B: styrene series monomers, unsaturated organic acids, anhydrides, or acid esters, or mixtures thereof

Claims16

Dependent claims

A low-shrinkage unsaturated polyester resin composition comprising (a) from 20 to 70% by weight of unsaturated polyester resin, (b) from 20 to 70% by weight of a first polymerizable monomer and (c) from 1 to 20% by weight of a block copolymer mixture having acid groups, said block copolymer mixture having been prepared by first copolymerizing (i) a polymeric peroxide having the formula ##STR10## wherein R.sub.1 is alkylene or substituted alkylene having 1 to 18 carbon atoms, cycloalkylene or substituted cycloalkylene having 3 to 15 carbon atoms, phenylene or substituted phenylene;

R.sub.2 is alkylene or substituted alkylene having 2 to 10 carbons atoms, ##STR11## wherein R.sub.3 is hydrogen or methyl, R.sub.4 is alkylene or substituted alkylene having 2 to 10 carbon atoms and m is an integer of 1 to 13, ##STR12## and n is an integer of 2 to 20, with (ii) a second monomer component selected from the group consisting of monomer A, monomer B, mixture of monomer A and an unsaturated organic acid, and mixture of monomer B and an unsaturated organic acid,
wherein monomer A consists of 70 to 100% by weight of vinyl acetate and up to 30% by weight of fourth monomer copolymerizable with vinyl acetate, and monomer B consists of 0 to 100% by weight of one or more styrene series monomers and 0 to 100% by weight of one or more unsaturated organic acid esters,
whereby to obtain a copolymer having peroxy bonds in the molecule, and then block copolymerizing said copolymer having peroxy bonds in the molecule with a third monomer component which is selected from the same group as, but is different from, the said second monomer component that was used in the first copolymerization step, with the provisos that one of said second and third monomer components is a mixture of one of monomer A or monomer B and said unsaturated organic acid and the other of said second and third monomer components is the other of monomer A or monomer B.

A low-shrinkage unsaturated polyester resin composition comprising (a) from 20 to 70% by weight of unsaturated polyester resin, (b) from 20 to 70% by weight of a first polymerizable monomer and (c) from 1 to 20% by weight of a block copolymer mixture having acid groups and having an acid value of from 0.5 to 20, said block copolymer mixture having been prepared by first copolymerizing, at a reaction temperature of from 40.degree. to 90.degree. C. and for a reaction time of from 2 to 15 hours, (i) a polymeric peroxide having the formula ##STR13## wherein R.sub.1 is alkylene or substituted alkylene having 1 to 18 carbon atoms, cycloalkylene or substituted cycloalkylene having 3 to 15 carbon atoms, phenylene or substituted phenylene;

R.sub.2 is alkylene or substituted alkylene having 2 to 10 carbon atoms, ##STR14## wherein R.sub.3 is hydrogen or methyl, R.sub.4 is alkylene or substituted alkylene having 2 to 10 carbon atoms and m is an integer of 1 to 13, ##STR15## and n is an integer of 2 to 20, with (ii) a second monomer component selected from the group consisting of monomer A, monomer B, mixture of monomer A and an unsaturated organic acid, and mixture of monomer B and an unsaturated organic acid,
wherein monomer A consists of 70 to 100% by weight of vinyl acetate and up to 30% by weight of fourth monomer copolymerizable with vinyl acetate, and monomer B consists of 0 to 100% by weight of one or more styrene series monomers and 0 to 100% by weight of one or more unsaturated organic acid esters,
the amount of said polymeric peroxide being from 0.1 to 10 parts by weight per 100 parts by weight of the monomer A or monomer B contained in said second monomer component, whereby to obtain a copolymer having peroxy bonds in the molecule, and then block copolymerizing said copolymer having peroxy bonds in the molecule with a third monomer component which is selected from the same group as, but is different from, the said second monomer component that was used in the first copolymerization step, with the provisos that one of said second and third monomer components is a mixture of one of monomer A or monomer B and said unsaturated organic acid, the other of said second and third monomer components is the other of monomer A or monomer B, and the amount of monomer A is from 10 to 90% by weight based on the sum of the amounts of monomer A plus monomer B.

Dependencies are inferred from the claim text.