An acrylic rubber contains a copolymer of a monomer mixture of: 25 to 46 wt. % of alkoxyalkyl acrylate, 23 to 37 wt. % of 2-ethylhexyl acrylate, 9 to 17 wt. % of alkyl methacrylate, 1 to 3 wt. % of monoalkyl fumarate and the remaining amount is ethyl acrylate. This acrylic rubber improves hydrolysis resistance by introducing a specific alkyl acrylic monomer with extremely low hydrolysis property i.e. low hydrophilicity, and at the same time satisfies all of oil resistance, cold resistance, and hydrolysis resistance in a well-balanced manner.

A composition for sealing joints, penetrations and other leaks in particular in the construction field, including at least one ethylenically unsaturated, radically polymerizable water-soluble compound, at least one radical initiator, water and at least one corrosion inhibitor including at least one phosphate. The corresponding composition has a corrosion-inhibiting effect with respect to metal.

An elastomeric article is provided that includes a composition having a silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3. The elastomeric article can exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70 C.). The silane-crosslinked polyolefin elastomer can include a first polyolefin having a density less than 0.86 g/cm.sup.3, a second polyolefin having a crystallinity less than 40%, a silane crosslinker, a grafting initiator, and a condensation catalyst.

A hot-melt composition includes, with respect to 100 parts by mass of (A) a hydrogenated styrene thermoplastic elastomer having styrene-based polymer blocks at both ends and a hydrogenated diene polymer block at a middle portion and having a mass-average molecular weight of 250,000-600,000, 20-150 parts by mass of (B) a first styrene-based tackifying resin having a softening point of 135-160 C., 100-400 parts by mass of (C) a second styrene-based tackifying resin having a softening point of 105-135 C., 100-500 parts by mass of (D) a third tackifying resin for the hydrogenated diene polymer block having a softening point of 100-160 C. and 500-1,500 parts by mass of (E) a liquid softener. The hot-melt composition has excellent adhesion and easy peel ability, and is a material suitable as a sealing material for a lighting device of an automobile or the like.

One aspect of the present invention is a hot melt composition containing a silane coupling agent, a thermoplastic polymer, a softener, and a catalyst, wherein the silane coupling agent is hydrolyzed to a compound having a boiling point of 70 to 180 C.

One aspect of the present invention is a hot melt composition including a modified thermoplastic polymer having an alkoxysilyl group in a molecule; a softener; and a catalyst.

Disclosed is a gas seal member for high-pressure hydrogen device with sufficiently reduced occurrence of both swelling destruction and blister destruction. The gas seal member is formed of a cross-linked product of an elastomer composition which comprises an elastomer and fibrous carbon nanostructures, wherein a hydrogen diffusion coefficient D1 of a cross-linked product of an elastomer component including the elastomer and a hydrogen diffusion coefficient D2 of the cross-linked product of the elastomer composition satisfy the relationship 0.7<D2/D1<1.0.

A closure plug of a battery includes an external thread for installing into an opening of a battery cover, and at least one gas-tight seal arranged on an outer side of the closure plug. The at least one gas-tight seal includes a mixture of polypropylene or polyethylene and polyisobutylene.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

To provide a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit which has a satisfactory oil resistance. A method for producing a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit includes a step for conducting continuous addition or 10 cycles or more of intermittent portionwise addition of the chloroprene monomer after initiation of a polymerization reaction is provided. A rubber composition using a statistical copolymer according to the invention or a vulcanized molded article containing the rubber composition is excellent in terms of oil resistance, mechanical strength, compression set at a low temperature and flex fatigue resistance.