An aqueous polymer latex composition is described for the preparation of an elastomeric film comprising: (I) particles of a latex polymer obtained by free-radical emulsion polymerization of a mixture of ethylenically unsaturated monomers, the particles bearing functional groups (a); and (II) a cross-linking component selected from monomeric compounds and oligomeric or polymeric compounds that are not prepared be free-radical addition polymerization, the cross-linking component comprising functional groups (b) and (c) that are different from each other, wherein functional group (b) forms upon reaction with functional group (a) a thermally reversible linkage selected from one or more of (i) a linkage having the structural formula

##STR00001##  wherein X, n, R1 and R2 are as defined; and (ii) a beta-hydroxy ester linkage; and functional groups (c) on different molecules of component (II) are capable of reacting with each other to provide elastomeric films having self-healing properties that can be repaired and recycled.

Acrylic rubber bale excellent in storage stability and processability, a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber bale, and a cross-linked product of the rubber mixture are provided. The acrylic rubber bale includes an acrylic rubber having a reactive group and a weight average molecular weight (Mw) of 100,000 to 5,000,000, wherein an amount of gel insoluble in methyl ethyl ketone is 50% by weight or less, and a specific gravity is 0.8 or more.

An acrylic rubber bale excellent in strength properties and processability, a method for producing the same, a rubber mixture containing the acrylic rubber bale, a method for producing the same, and a rubber cross-linked product of the same. The acrylic rubber bale includes an acrylic rubber mainly containing a (meth) acrylic acid ester having a weight average molecular weight (Mw) of 1,000,000 to 5,000,000, and a ratio (Mz/Mw) of a Z-average molecular weight (Mz) and a weight average molecular weight (Mw) is 1.3 or more, wherein an amount of gel insoluble in methyl ethyl ketone is 50% by weight or less.

Acrylic rubber bale excellent in storage stability and processability, a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber bale, and a cross-linked product of the rubber mixture are provided. The acrylic rubber bale includes an acrylic rubber having a reactive group and a weight average molecular weight (Mw) of 100,000 to 5,000,000, wherein an amount of gel insoluble in methyl ethyl ketone is 60% by weight or less, and a specific gravity is 0.8 or more.

An acrylic rubber sheet excellent in storage stability and water resistance, a method for producing the same, a rubber mixture containing the acrylic rubber sheet and a rubber cross-linked product thereof are provided. The acrylic rubber sheet according to the present invention includes an acrylic rubber having a reactive group and having a weight average molecular weight (Mw), a ratio of a Z-average molecular weight (Mz) and a weight average molecular weight (Mw) in a specific range. The acrylic rubber sheet according to the present invention has an ash content of 0.2% by weight or less, an amount of gel insoluble in methyl ethyl ketone is 50% by weight or less, and a water content of less than 1% by weight, and is excellent in water resistance and highly well-balanced in strength properties and processability.

Acrylic rubber bale having remarkably improved storage stability and water resistance without deteriorating cross-linking properties, a method of production, a rubber mixture obtained by mixing the acrylic rubber bale, a method of production, and a rubber cross-linked product obtained by cross-linking the same is provided. The acrylic rubber bale includes an acrylic rubber, and the acrylic rubber is mainly composed of (meth) acrylic acid ester, and has a weight average molecular weight of 100,000 to 5,000,000, and has a ratio of a Z-average molecular weight and a weight average molecular weight of 1.3 or more, where an ash content is 0.6% by weight or less, and the ash contains a periodic table group 2 metal and phosphorus, and a phosphorus content is 10% by weight or more, and the ratio of the periodic table group 2 metal to phosphorus is in the range of 0.6 to 2 molar ratio.

A carboxyl group-containing nitrile rubber comprising an α,β-ethylenically unsaturated nitrile monomer unit in a content of 5 to 60 wt % and having an iodine value of 120 or less, wherein the carboxyl group-containing nitrile rubber has a polymer Mooney viscosity (ML1+4, 100° C.) of 60 or less and a polymer pH of 7 or less.

A carboxyl group-containing nitrile rubber comprising an α,β-ethylenically unsaturated nitrile monomer unit in a content of 5 to 60 wt % and having an iodine value of 120 or less, wherein the carboxyl group-containing nitrile rubber has a polymer Mooney viscosity (ML1+4, 100° C.) of 60 or less and a polymer pH of 7 or less.

The present invention relates to a process for producing PEG acrylate-HNBR copolymer which exhibits excellent processability by latex hydrogenation of PEG acrylate-NBR latex to afford PEG acrylate-HNBR latex and subsequent coagulation.

The present invention relates to a process for producing PEG acrylate-HNBR copolymer which exhibits excellent processability by latex hydrogenation of PEG acrylate-NBR latex to afford PEG acrylate-HNBR latex and subsequent coagulation.