Abstract: A graft precursor is formed by preparing a propylene polymer suspension having a propylene polymer suspended in water and a solution having a specific radically (co)polymerizable organic peroxide and a specific radical polymerization initiator dissolved in specific amounts in a vinyl monomer, mixing the propylene suspension and the solution in a specific ratio, heating and stirring the resultant mixture under conditions incapable of inducing substantial decomposition of the polymerization initiator, and further elevating the temperature of the mixture after the total amount of the vinyl monomer, the radically (co)polymerizable organic peroxide, and the radical polymerization initiator has decreased to less than 50% by weight of the initial total amount. Then a graft resin composition is produced by melting and kneading the graft precursor, either by itself or in combination with a propylene polymer and a vinyl polymer, at a temperature in the range of 100.degree. to 300.degree. C.

Abstract: An ethylene-acrylic acid ester copolymer can be easily grafted in a high graft efficiency with a peroxy group-containing block copolymer consisting of segments of copolymer A, which is a copolymer of a (meth)acrylic acid ester monomer or its mixture with a radically copolymerizable monomer, with a radically copolymerizable peroxycarbonate, and segments of (co)polymer B, which is different from copolymer A in the monomer composition and does not contain a monomer unit of the radically copolymerizable peroxycarbonate. The grafted ethylene-acrylic acid ester copolymer can be effectively used as a compatibilizing agent in a polymer blend of polyolefin with styrene (co)polymer, as an emulsifying agent in an emulsion of high polymer, or as an adhesive at the interface of polyolefin and styrene (co)polymer.

Abstract: A block copolymer consisting of segments of copolymer A, which is obtained by copolymerizing an aromatic vinyl monomer with a radically copolymerizable peroxycarbonate and has peroxy groups in its main polymer chain, and segments of (co)polymer B, which is different from copolymer A in the monomer composition and does not contain peroxy groups, can modify matrix resin without deteriorating the mechanical property of the resin.

Abstract: A block copolymer consisting of segments of copolymer A, which is obtained by copolymerizing a (meth)acrylic acid ester monomer with a radically copolymerizable peroxycarbonate and has peroxy groups in its main polymer chain, and segments of (co)polymer B, which is different from copolymer A in the monomer composition and does not contain peroxy groups, can modify matrix resin without deteriorating the mechanical property of the resin.

Abstract: A plastic lens which has high hardness and excellent scratch resistance and can form a transparent and uniform reflection preventing film through vacuum deposition, is produced by mixing(a) diethylene glycol bis(allyl carbonate) with(b) at least one of organic peroxides having a decomposition temperature at selected half-life value for ten hours of not higher than 80.degree. C. and(c) at least one of organic peroxides having a decomposition temperature at selected half-life value for ten hours of 90.degree.-110.degree. C., which have no copolymerizability to the diethylene glycol bis(allyl carbonate) (a), as a polymerization initiator, and polymerizing and casting the resulting mixture in a desired lens-forming mold.

Abstract: Disclosed herein is a low shrinkable unsaturated polyester resin composition consisting of (A) 20-70% by weight of an unsaturated polyester, (B) 28-60% by weight of a monomer polymerizable with the above unsaturated polyester, and (C) 2-20% by weight of a block copolymer mixture. The mixtures of the monomer (B) and the block copolymer mixture (C), and a mixture of the polyester (A), the monomer (B), and the block copolymer mixture (C) are in a non-aqueous dispersion state. The block copolymer mixture is obtained by polymerizing either one of the monomers defined below in (a) and (b) with a polymerization initiator a polymeric perioxide represented by the formula: ##STR1## in which R.sub.1 represents a divalent branched hydrocarbon group having 10-30 carbons, and R.sub.2 and R.sub.

Abstract: A plastic lens which has high hardness and excellent scratch resistance and can form a transparent and uniform reflection preventing film through vacuum deposition, is produced by mixing(a) diethylene glycol bis(allyl carbonate) with(b) at least one of organic peroxides having a decomposition temperature at selected half-life value for ten hours of not higher than 80.degree. C. and(c) at least one of specifically limited peroxycarbonates having a radical copolymerizability to the diethylene glycol bis(allyl carbonate) (a), as a polymerization initiator, and polymerizing and casting the resulting mixture in a desired lens-forming mold.

Abstract: Styrene-type monomers are polymerized, or mixtures of styrene-type monomers and other vinyl type monomers and copolymerized, at 50.degree.-120.degree. C. using 1-10 wt%, based on the weight of the monomers, of an organic peroxide polymerization initiator whose decomposition temperature at 10 hours of halflife is 40.degree. C. to 70.degree. C. whereby colorless low molecular weight styrene series polymers are obtained at a high yield, using polymerization apparatus of simple structure.