Abstract: A process for producing a polymer of excellent weatherability, which comprises reacting a polymer having a thioether bond, with a peroxide to oxidize the sulfur atom in the bond to convert it into a sulfone.

Abstract: The present invention provides a thermosetting coating resin consisting of a branched polymer, which branched polymer is obtained by copolymerizing a macromolecular monomer having a radical-polymerizable group at one end in the molecule and having a weight-average molecular weight of 1,000-10,000, with another radical-polymerizable monomer, which branched polymer contains the unit of said macromolecular monomer in a proportion of 40-99.5% by weight based on the amount of total constitutional units, which branched polymer has a cross-linkable functional group, and which branched polymer has a weight-average molecular weight of 5,000-30,000. The present invention further provides a process for producing such a thermosetting coating resin.

Abstract: A process for producing an aqueous resin dispersion is disclosed, which comprises dissolving a macromonomer having a radical polymerizable group at the terminal thereof and an oil-soluble radical polymerization initiator in a hydrophobic vinyl monomer copolymerizable with the macromonomer to form a solution, emulsifying the solution in an aqueous medium in the presence of an emulsifying agent selected from (A) an alkali sulfosuccinate anionic surfactant and (B) a surfactant comprising from 2 to 98% by weight of (i) an alkali sulfonate anionic surfactant other than (A) or (ii) an alkali sulfuric ester anionic surfactant, and from 98 to 2% by weight of a nonionic surfactant having an HLB value of 10 or more, and copolymerizing the macromonomer and the vinyl monomer at an elevated temperature. The aqueous resin dispersion has a high content of a graft polymer with a reduced content of unreacted macromonomer.

Abstract: An ethylene graft copolymer is disclosed, which is obtained by radical polymerizing a monomer composition comprising (A) from 50 to 99.95% by weight of ethylene, (B) from 0.05 to 50% by weight of a macromonomer having a number average molecular weight of from 2,000 to 20,000 and having a (meth)acryloyl group only at one terminal of the molecular chain thereof, and (C) 0 to 49.95% by weight of other radical polymerizable monomer(s). The ethylene graft copolymer is a modifier for improving impact resistance of engineering plastics or a compatibilizer for engineering plastics to provide a molding resin composition excellent in impact resistance and oil resistance. The ethylene graft copolymer is also useful as a hot-melt adhesive or a pressure-sensitive adhesive.

Abstract: A process for producing a macromolecular monomer, which comprises anionic polymerization of a (meth)acrylic acid ester monomer by using, as a polymerization initiator, a compound represented by the following general formula [I]: ##STR1## wherein M.sup.+ is a quaternary ammonium ion; .phi.is a phenylene group; R.sub.1 and R.sub.2 are each an electron withdrawing group stabilizing the carbanion C.sup.-, or one of them is said electron withdrawing group and the other is an alkyl group of 1-6 carbon atoms or a phenyl group; and n is an integer of 0-6.

Abstract: Provided is a process for producing hydroxylapatite suitable for chromatographic separation of biopolymers. The process comprises allowing hexagonal prismatic or acicular monetite to react with potassium hydroxide and/or lithium hydroxide under heating.

Abstract: A magnetic recording medium having a modified surface, consisting essentially of (a) a substrate, (b) a ferromagnetic metal thin film formed on one side of the substrate by a vacuum deposition method, an ion plating method, a sputtering method or a plating method and (c) a lubricating coating layer formed on the thin film or on the back of the substrate or on both of them. The recording medium has an improved running stability, durability and corrosion resistance.

Abstract: A process for producing acrylic acid or methacrylic acid by reacting acetic acid or propionic acid with formaldehyde in a gas phase is described, characterized by carrying out the reaction in the presence of a solid catalyst containing at least one of boron oxide or phosphorus oxide and having an acid site of an acid strength, pKa.ltoreq.-3.0. The solid catalyst is of high activity and is satisfactory in both selectivity and conversion and, furthermore, its high selectivity can be maintained for long periods of time. Thus the desired product, acrylic acid or methacrylic acid, can be produced in high yield.