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.

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.

An acrylic rubber excellent in water resistance and a method for producing the same are provided. An acrylic rubber composed of: 70 to 99.9 wt % of a bonding unit derived from (meth) acrylic acid ester; 0.1 to 10 wt % of a bonding unit derived from a cross-linkable monomer; and if necessary, 0 to 20 wt % of a bonding unit derived from another monomer, wherein the ash content is 0.5 wt % or less, the total amount of magnesium and phosphorus in the ash is 30 wt % or more, a ratio of the magnesium to the phosphorus ([Mg]/[P]) by weight is 0.4 to 2.5, and Mooney viscosity (ML1+4, 100° C.) of the rubber is 10 to 150 is particularly excellent in water resistance, and a rubber cross-linked product using the same is also excellent in physical properties.

An acrylic rubber excellent in water resistance and a method for producing the same are provided. An acrylic rubber composed of: 70 to 99.9 wt % of a bonding unit derived from (meth) acrylic acid ester; 0.1 to 10 wt % of a bonding unit derived from a cross-linkable monomer; and if necessary, 0 to 20 wt % of a bonding unit derived from another monomer, wherein the ash content is 0.5 wt % or less, the total amount of magnesium and phosphorus in the ash is 30 wt % or more, a ratio of the magnesium to the phosphorus ([Mg]/[P]) by weight is 0.4 to 2.5, and Mooney viscosity (ML1+4, 100° C.) of the rubber is 10 to 150 is particularly excellent in water resistance, and a rubber cross-linked product using the same is also excellent in physical properties.

The curable composition for imprinting includes: a compound represented by the following Formula (1); a radically polymerizable compound other than the compound represented by Formula (1); and a photoradical polymerization initiator, in Formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or an organic group having 1 to 8 carbon atoms and may be bonded to each other to form a ring, R.sup.3 represents a monovalent organic group, and R.sup.4 and R.sup.5 each independently represent a hydrogen atom or a monovalent organic group. ##STR00001##

The curable composition for imprinting includes: a compound represented by the following Formula (1); a radically polymerizable compound other than the compound represented by Formula (1); and a photoradical polymerization initiator, in Formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or an organic group having 1 to 8 carbon atoms and may be bonded to each other to form a ring, R.sup.3 represents a monovalent organic group, and R.sup.4 and R.sup.5 each independently represent a hydrogen atom or a monovalent organic group. ##STR00001##

A cross-linkable nitrile rubber composition that includes a nitrile group-containing copolymer rubber (A), silica (B1), clay (B2), calcium carbonate (B3), and a polyamine-based cross-linking agent (C). A total amount of the silica (B1), the clay (B2), and the calcium carbonate (B3) is 150 to 200 parts by weight with respect to 100 parts by weight of the nitrile group-containing copolymer rubber (A), a content ratio of the silica (B1) is greater than 0 wt % and 50 wt % or less with respect to the total amount of the silica (B1), the clay (B2), and the calcium carbonate (B3), and a content ratio of the clay (B2) and the calcium carbonate (B3) is 30:70 to 90:10 in a weight ratio of “clay (B2):calcium carbonate (B3)”.

A cross-linkable nitrile rubber composition that includes a nitrile group-containing copolymer rubber (A), silica (B1), clay (B2), calcium carbonate (B3), and a polyamine-based cross-linking agent (C). A total amount of the silica (B1), the clay (B2), and the calcium carbonate (B3) is 150 to 200 parts by weight with respect to 100 parts by weight of the nitrile group-containing copolymer rubber (A), a content ratio of the silica (B1) is greater than 0 wt % and 50 wt % or less with respect to the total amount of the silica (B1), the clay (B2), and the calcium carbonate (B3), and a content ratio of the clay (B2) and the calcium carbonate (B3) is 30:70 to 90:10 in a weight ratio of “clay (B2):calcium carbonate (B3)”.

An acrylic rubber bale excellent in storage stability and water resistance and a method for producing the same are provided. An acrylic rubber bale, including an acrylic rubber having a reactive group, with a specific ash content, a large proportion of magnesium and phosphorus in the ash, and a specific ratio of magnesium and phosphorus, is highly excellent in storage stability and water resistance. This acrylic rubber bale can be produced by using a specific stabilizer and a specific coagulant in an emulsion polymerization process of an acrylic rubber and performing a process from coagulation process to baling process under specific conditions.

An acrylic rubber bale excellent in storage stability and water resistance and a method for producing the same are provided. An acrylic rubber bale, including an acrylic rubber having a reactive group, with a specific ash content, a large proportion of magnesium and phosphorus in the ash, and a specific ratio of magnesium and phosphorus, is highly excellent in storage stability and water resistance. This acrylic rubber bale can be produced by using a specific stabilizer and a specific coagulant in an emulsion polymerization process of an acrylic rubber and performing a process from coagulation process to baling process under specific conditions.