Abstract: Block copolymers of poly(N-formylethyleneimine) or poly(N-acetylethyleneimine) with poly(N-acylethyleneimine or poly(N-acylpropyleneimine) having a molecular weight of 500 to 50,000 and a method for their production. These block copolymers are useful as surface active agents.

Abstract: A composition comprises 100 parts by weight of a vinyl chloride type resin and 25 to 200 parts by weight of a plasticizer, the vinyl chloride type resin being composed of 1 to 90% by weight of tetrahydrofuran-insoluble gel fraction and the balance of tetrahydrofuran-soluble fraction. This composition gives a rubbery elastomer having an excellent heat deformation resistance and an excellent matt finish and a small compression permanent set. Though it is close to rubber in properties, the composition has a moldability and processability similar to those of conventional thermoplastic resins, and can be formed into a sheet for interior material of automobile, a packing, a tube, etc.

Abstract: A method for producing a vinyl chloride resin comprising 10 to 80% by weight of tetrahydrofuran-insoluble vinyl chloride resin gel fraction and the balance of tetrahydrofuran-soluble fraction with an average polymerization degree of 1,000 or more, characterized in that vinyl chloride alone or a mixture of a major amount of vinyl chloride and a minor amount of at least one monomer copolymerizable therewith is polymerized at a temperature of 0.degree. to 50.degree. C. in the presence of at least one polyfunctional monomer having two or more ethylenic double bonds in the molecule until the whole monomer or monomers in the polymerization system are substantially polymerized. The thus obtained vinyl chloride resin is excellent in processability and capable of forming a molded article having a small compression permanent set.