摘要:
Provided is a polychloroprene having narrower molecular weight distribution, a method of producing the same and an adhesive containing the same. Chloroprene alone or a mixture of chloroprene and a monomer copolymerizable with chloroprene is radically polymerized in the presence of a dithiocarbamic ester compound represented by the following Chemical Formula (A).
摘要:
An ethylene/aromatic vinyl copolymer characterized by satisfying the following: (1) It has an aromatic vinyl content of 0.5 to 10 mol%; (2) It gives a 0.2 mm-thick molding which has a haze of 14% or lower or a total light transmittance of 90 % or higher; (3) It satisfies the following relationship (1) between the aromatic vinyl content and the glass transition point (Tg) which is determined by the inflection point method and is observed with a differential scanning calorimeter (DSC) at temperatures not lower than -50 °C: -20 + 1.00St > Tg > -30 + 1.05St relationship (1) wherein St represents the aromatic vinyl content of the copolymer (mol%); (4) It has a weight-average molecular weight of 140,000 to 500,000 when the aromatic vinyl content is 5 to 10 mol%, and of 60,000 to 500,000 when the aromatic vinyl content is 0.5 to 5 mol%, excluding 5 mol%.
摘要:
Provided is a polychloroprene latex extremely superior in adhesion properties. According to the present invention, chloroprene or a mixture of chloroprene and a monomer copolymerizable with chloroprene is polymerized in the presence of a surfactant in an aqueous medium, in which the surfactant's concentration is lower than its critical micelle concentration (CMC) to obtain a polychloroprene latex. The polychloroprene latex produced according to the present invention is extremely superior in adhesion properties and others and give a smaller amount of deposits during production.
摘要:
Provided is a sulfur-modified chloroprene elastomer composition superior both in viscosity stability during storage and scorching resistance during processing and a blend and vulcanized article thereof. A sulfur-modified chloroprene elastomer composition, containing a thiuram compound in an amount of 1 to 2.5 mass % and having an organic acid content, as determined in accordance with JIS K6237, of 1.5 to 15 mass %, an ash content, as determined in accordance with JIS K6228, of 0.03 to 0.2 mass %, and a mass ratio of the organic acid content to the ash content (organic acid content/ash content) of 50 to 500, as they are so regulated by modification of the blending amount of the emulsifier.
摘要:
A medical material and a medical supply which each comprises an aromatic vinyl/α-olefin random copolymer. They contain substantially no chlorine, and have not only excellent flexibility and transparency and moderate resilience but radiation resistance and biocompatibility. They are hence advantageously used especially in the medical field.
摘要:
A process for producing an olefin/aromatic vinyl copolymer which comprises conducting polymerization so as to satisfy that (a) the conversion of the aromatic vinyl monomer as measured at the termination of the polymerization is 50 mol% or higher and/or (b) the polymer solution resulting from the polymerization has a polymer concentration of 10 wt.% or higher as measured at the termination of the polymerization, and conducting the polymerization while changing the partial olefin pressure so that the partial olefin pressure as measured at the termination of the polymerization is 1.3 to 20 times that at the beginning of the polymerization. Thus, an olefin/aromatic vinyl copolymer excellent in transparency, heat resistance, and moldability is produced with practical high productivity.
摘要:
A novel olefin/styrene/diene cross copolymer having excellent physical and mechanical properties; a novel, efficient and economical process for the production of the same; efficient and economical processes for the production of various cross copolymers including olefin/diene cross copolymers; and various resin compositions and works containing the novel cross copolymer, which are freed from the problems of resin compositions and works of the prior art or improved therein.