Abstract: Provided is a sulfur-modified polychloroprene that generates a smaller amount of nitrosamine compounds during kneading or curing operation. A sulfur-modified polychloroprene, comprising functional groups having a structure represented by Chemical Formula I (in Chemical Formula I, R0 represents an alkyl group having 1 to 4 carbon atoms and x is an integer of 2 to 8) in an amount of 0.05 to 0.

Abstract: Provided are a sulfur-modified chloroprene rubber with reduced exothermicity, a molding thereof, and a production method therefor. A sulfur-modified chloroprene rubber modified at the polymer terminals with at least one compound selected from tetramethylthiuram disulfide, tetraalkylthiuram disulfides with alkyl groups having a carbon number of 2 to 7 and dialkyldithiocarbamic acid salts with alkyl groups having a carbon number of 1 to 7, wherein there are peak tops at 3.55 to 3.61 ppm and at 3.41 to 3.47 ppm in 1H-NMR spectrum, as determined in deuterochloroform solvent, wherein the ratio (A/B) of the peak area (A) at 3.55 to 3.61 ppm to the peak area (B) at 4.2 to 6.5 ppm is 0.05/100 to 0.50/100, and the extract with ethanol/toluene azeotropic mixture, as specified by JIS K 6229, is 3.0 to 9.0 mass %.

Abstract: There is provided an alumina fiber capable of fixing a honeycomb carrier while maintaining elasticity for a long period of time even in a severe usage environment, and an alumina fiber aggregate formed of the fiber. Problems in a gripping material of an automotive honeycomb carrier are solved by applying an alumina fiber containing from 70 to 98% by mass of alumina and from 2 to 30% by mass of silica, having an average fiber diameter of from 3.0 to 8.0 ?m, a ratio of fibers having a fiber diameter exceeding 10 ?m being 5% or less in terms of the number of fibers and a size of a mullite crystallite contained in each fiber of from 10 to 1500 ?, and by forming an alumina fiber aggregate by using the fibers.

Abstract: Provided are a sulfur-modified chloroprene rubber with reduced exothermicity, a molding thereof, and a production method therefor. A sulfur-modified chloroprene rubber modified at the polymer terminals with at least one compound selected from tetramethylthiuram disulfide, tetraalkylthiuram disulfides with alkyl groups having a carbon number of 2 to 7 and dialkyldithiocarbamic acid salts with alkyl groups having a carbon number of 1 to 7, wherein there are peak tops at 3.55 to 3.61 ppm and at 3.41 to 3.47 ppm in 1H-NMR spectrum, as determined in deuterochloroform solvent, wherein the ratio (A/B) of the peak area (A) at 3.55 to 3.61 ppm to the peak area (B) at 4.2 to 6.5 ppm is 0.05/100 to 0.50/100, and the extract with ethanol/toluene azeotropic mixture, as specified by JIS K 6229, is 3.0 to 9.0 mass %.