Abstract: Alkoxyamines containing a vinyl group as represented by the following general formula (1) are produced in a method which comprises a process of heating divinyl benzene, nitroxide compound and organic peroxide up to a temperature at which the organic peroxide decomposes thermally: (In the formula, R1 represents an aryl group or an R2O group, wherein R2 represents a linear or branched alkyl group having 1-12 carbon atoms or a cycloalkyl group. R3 and R4 are each tertiary alkyl group having 4-6 carbon atoms or of cyclic structure where R3 and R4 are connected with each other having a total carbon number of 8-16. In case of cyclic structure, they are optionally substituted either by an alkyl group, an oxo group, a hydroxyl group, an acyloxy group or an alkoxy group.) Furthermore, graft polymers can be produced by the use of high molecular radical polymerization initiators from which an alkoxyamine group suspends.

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.

Abstract: An unsaturated polyester resin composition which is obtained by incorporating a thermoplastic random-copolymer having peroxycarbonate groups in the molecule thereof into an unsaturated polyester resin, which composition is excellent in low shrinkage characteristics and it is not weakened in mechanical strength.

Abstract: A styrene resin composition which is admixed with a styrene-vinyl acetate block copolymer is improved in the fluidity without degrading the mechanical strength and electric insulation resistance. Said vinyl acetate block polymer can easily be obtained by using a polymeric peroxide having ester bonds in the molecule thereof, notwithstanding that a copolymer of a styrene and a vinyl acetate could not be prepared easily by the prior art.