Provided is a crosslinked rubber having excellent workability and heat resistance, and a crosslinkable rubber composition that can be used to form the crosslinked rubber. The crosslinkable rubber composition contains: a rubber including a carboxyl group-containing ethylenically unsaturated monomer unit; an amine-based crosslinking agent having a melting point of at least 50 C. and no higher than 180 C.; and one or more carbon nanotubes. The crosslinked rubber is obtainable through crosslinking of the crosslinkable rubber composition. The carbon nanotubes preferably have a BET specific surface area of from 600 m.sup.2/g to 2,000 m.sup.2/g.

A curable liquid rubber composition having improved viscosity stability is provided. The curable liquid rubber composition includes at least one functionalized crosslinkable polymer that is liquid at 25 C., contains at least one diene monomer in polymerized form, and is functionalized with one or more anhydride functional groups, one or more hydroxyl functional groups or one or more (meth)acrylate functional groups; at least one non-functionalized crosslinkable polymer that is liquid at 25 C., contains at least one diene monomer in polymerized form, and is not functionalized with anhydride, hydroxyl or (meth)acrylate functional groups; at least one metallic monomer coagent which is a metal carboxylate salt containing at least one (meth)acrylate functional group; and at least one inorganic filler. The curable liquid rubber composition has a total moisture content of not more than 1000 ppm, whereby controlling the amount of water reduces the tendency of the composition to exhibit an increase in viscosity over time.

A crosslinkable rubber composition includes a carboxyl group-containing highly saturated nitrile copolymer rubber, and silica treated with silicone oil.

A self-healing hydraulic seal is provided. The self-healing hydraulic seal is prepared from a water-swellable elastomeric composition comprising a base polymer and a plant-based polysaccharide.

A self-healing hydraulic seal is provided. The self-healing hydraulic seal is prepared from a water-swellable elastomeric composition comprising a base polymer and a plant-based polysaccharide.

A carbamate ester compound represented by the general formula:
ZOCONH(CH.sub.2).sub.nNHCOOZ[I]
wherein Z is [i], [ii], or [iii] below, and n is an integer of 2 to 10, ##STR00001## (wherein R.sup.1 and R.sup.2 are each independently a lower alkyl group having 1 to 5 carbon atoms, R.sup.3 is a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and a is 1 or 2). The carbamate ester compound is used as a vulcanizing agent for carboxyl group-containing acrylic rubber and improves the delay of the vulcanization rate by scorch suppression.

A carbamate ester compound represented by the general formula:
ZOCONH(CH.sub.2).sub.nNHCOOZ[I]
wherein Z is [i], [ii], or [iii] below, and n is an integer of 2 to 10, ##STR00001## (wherein R.sup.1 and R.sup.2 are each independently a lower alkyl group having 1 to 5 carbon atoms, R.sup.3 is a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and a is 1 or 2). The carbamate ester compound is used as a vulcanizing agent for carboxyl group-containing acrylic rubber and improves the delay of the vulcanization rate by scorch suppression.

The present disclosure involves a preparation method of bio-based silica/poly (itaconate-ter-isoprene-ter-glycidyl methacrylate) nanocomposite. Bio-based silica/poly (itaconate-ter-isoprene-ter-glycidyl methacrylate) nanocomposite is environment-friendly, and silica and poly (itaconate-ter-isoprene-ter-glycidyl methacrylate) are derived from non-petroleum base materials, which do not rely on fossil fuel. Compared with nanocomposite without nanocomposite, nanocomposites with glycidyl methacrylate have better silica diffusion, mechanical properties and wet-skid resistance of rubber product are improved while consuming the same time. Further, rolling resistance is decreased so that using silane coupling agent is avoided. Therefore, the processing technology is simplified, and VOC emission is avoided. It is a kind of green tire rubber product.

The present disclosure involves a preparation method of bio-based silica/poly (itaconate-ter-isoprene-ter-glycidyl methacrylate) nanocomposite. Bio-based silica/poly (itaconate-ter-isoprene-ter-glycidyl methacrylate) nanocomposite is environment-friendly, and silica and poly (itaconate-ter-isoprene-ter-glycidyl methacrylate) are derived from non-petroleum base materials, which do not rely on fossil fuel. Compared with nanocomposite without nanocomposite, nanocomposites with glycidyl methacrylate have better silica diffusion, mechanical properties and wet-skid resistance of rubber product are improved while consuming the same time. Further, rolling resistance is decreased so that using silane coupling agent is avoided. Therefore, the processing technology is simplified, and VOC emission is avoided. It is a kind of green tire rubber product.

A carboxyl group-containing acrylic rubber composition comprising (A) carboxyl group-containing acrylic rubber, (B) 1,4-diazabicyclo[2.2.2]octane, (D) a crosslinking agent for carboxyl group-containing acrylic rubber, and (E) a guanidine-based, thiuram-based, or thiourea-based crosslinking accelerator. The carboxyl group-containing acrylic rubber composition can form an acrylic rubber layer having excellent bonding strength to a fluororubber layer by crosslinking bonding a fluororubber composition. The carboxyl group-containing acrylic rubber composition may further comprise (C) a primary amine represented by the general formula RNH.sub.2, wherein R is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, thereby increasing interlaminar bonding force.