Abstract: A process for producing a highly expanded polypropylene foam which is uniform in viscosity during extrusion foaming, improved in melt strength and free from unevenness of surface by using a polypropylene resin having a specified melt tension.

Abstract: A process for producing glass fiber-reinforced, transparent cast sheets comprising impregnating glass fibers with a resin syrup comprising 10 to 50 parts by weight of a copolymer (A) consisting essentially of 20 to 95% by weight of an aromatic vinyl compound and 5 to 80% by weight of other polymerizable monomer, 1 to 40 parts by weight of an aromatic vinyl compound (B), 50 to 90 parts by weight of other polymerizable monomer (C) and optionally 0.5 to 10 parts by weight of maleic anhydride, and casting the resulting mixture.

Abstract: A continuous process for producing rubber-modified methyl methacrylate syrups which comprises continuously supplying a material liquor comprising 1 to 20 parts by weight of a rubbery polymer dissolved in 100 parts by weight of a monomer comprising 60 to 100% by weight of methyl methacrylate, and a radical-polymerization initiator to the first reaction zone, continuously polymerizing at such a stationary conversion that the rubber polymer is dispersed in the form of particles form while maintaining the temperature and residence time in the zone so that a steady state is achieved in the zone and the steady-state concentration of the initiator in the zone is 1/2 to 1/1,000 time as much as the concentration of initiator supplied, continuously taking out the resulting reaction mixture from the zone, and passing it through the second reaction zone having a volume of 0 to 5 times as much as that of the first reaction zone, to obtain a stable syrup comprising a disperse phase and a continuous phase, the former phase

Abstract: A novel copolymer resin having excellent compatibility with rubber and plastics, stable to air, easily soluble in the hydrocarbon solvents and free of gel, said resin being obtained either (1) by copolymerizing one or more of the monomeric substances selected from the group consisting of cyclopentadiene, dicyclopentadiene and alkyl-substituted compounds thereof and one or more of the substances selected from the hydroxystyrene derivatives, or (2) by copolymerizing one or more of the monomeric substances selected from the group consisting of cyclopentadiene, dicyclopentadiene and alkyl-substituted compounds thereof, one or more of the substances selected from the codimers of cyclopentadiene and/or alkyl-substituted compounds thereof and chain conjugated diolefins having 4 to 5 carbon atoms, and one or more of the substances selected from the hydroxystyrene derivatives. There are also provided compositions comprising said resin and rubber or thermoplastic high-molecular weight substances.

Abstract: In the production of petroleum resins by polymerizing an unsaturated hydrocarbon-containing fraction having a boiling point ranging from -20.degree. to 200.degree. C. at -50.degree. to 100.degree. C., an improvement for producing light-colored clear petroleum resins which comprises using an aluminum chloride/fatty acid ester/aromatic hydrocarbon complex solution.

Abstract: A petroleum resin produced by copolymerizing a monomer composition comprising (1) a mixture of 20 to 80 parts by weight of a so-called spent C.sub.4 - or C.sub.5 -fraction obtained by removing most of the dienic constituents from a fraction mainly of four or five carbon atoms formed in petroleum cracking and 80 to 20 parts by weight of styrene and/or a styrene derivative, and (2) 0.5 to 10 parts by weight of divinylbenzene for 100 parts by weight of the monomeric constituents contained in said mixture (1), with a catalyst system comprising an organoaluminum compound represented by the general formula AlR.sub.n X.sub.3.sub.-n (wherein R is an alkyl group having 1 to 4 carbon atoms, X is a halogen atom, and n is a positive number from 1 to 2) as main catalyst and an alkyl halide or a hydrogen halide as co-catalyst in a hydrocarbon solvent at a temperature of 0.degree. to 60.degree. C.

Abstract: A novel petroleum resin having not only a relatively low molecular weight but a narrow molecular weight distribution and having excellent characteristics as a tackifier particularly suitable for use in hot-melt adhesives and also suitable for synthetic rubbers, adhesive tapes, sealants, and the like, which resin is obtained by copolymerizing 20 to 80 parts by weight of a so-called spent C.sub.4 - or C.sub.5 -fraction obtained by removing most of the dienic constituents from the fractions mainly of C.sub.4 or C.sub.5 carbon atoms produced by petroleum cracking and 80 to 20 parts by weight of styrene and/or a styrene derivative with a catalyst system comprising an organoaluminum compound represented by the general formula AlRX.sub.2 (wherein R is an alkyl group having 1 to 4 carbon atoms and X is a halogen atom) as main catalyst and an alkyl halide or a hydrogen halide as co-catalyst, in a hydrocarbon solvent at a temperature of 0.degree. to 60.degree. C.

Abstract: A process for producing a petroleum resin which comprises polymerizing in the presence of a Friedel-Crafts catalyst a C.sub.5 -fraction from cracked naphtha or oil gas, which has been subjected to an adjustment of a weight ratio of acyclic diolefins to monoolefins and a weight ratio of cyclic diolefins to monoolefins to from 0.40 to 0.70 and from 0.07 to 0.35, respectively.