The dewaxing aid of the present invention is a dewaxing aid including an ethylene-α-olefin copolymer (A) having a molar ratio [(a)/(b)] of (a) ethylene and (b) an α-olefin having 3 or more and 12 or less carbon atoms of 93/7 to 75/25, and having a weight average molecular weight of 10,000 to 500,000. According to the present invention, a dewaxing aid that is excellent in improving filterability can be provided.

Provided is a thermoplastic resin composition exhibiting both high transmittance and low haze and having excellent transparency and excellent scratch resistance and toughness. The thermoplastic resin composition of the present disclosure contains 50% to 99% by mass of methacrylic resin (A) and 1% to 50% by mass of thermoplastic polyurethane (B), wherein the methacrylic resin (A) contains 80.0% to 99.9% by mass of methacrylate ester monomer unit, 0.1% to 20.0% by mass of vinyl monomer unit containing a vinyl monomer copolymerizable with a methacrylate ester monomer excluding maleic acid and maleic anhydride, and 0% to 4.0% by mass of maleic acid and/or maleic anhydride monomer unit, and the thermoplastic polyurethane (B) has a structural unit derived from polyester polyol and a structural unit derived from isocyanate having an alicyclic ring.

Provided is a thermoplastic resin composition exhibiting both high transmittance and low haze and having excellent transparency and excellent scratch resistance and toughness. The thermoplastic resin composition of the present disclosure contains 50% to 99% by mass of methacrylic resin (A) and 1% to 50% by mass of thermoplastic polyurethane (B), wherein the methacrylic resin (A) contains 80.0% to 99.9% by mass of methacrylate ester monomer unit, 0.1% to 20.0% by mass of vinyl monomer unit containing a vinyl monomer copolymerizable with a methacrylate ester monomer excluding maleic acid and maleic anhydride, and 0% to 4.0% by mass of maleic acid and/or maleic anhydride monomer unit, and the thermoplastic polyurethane (B) has a structural unit derived from polyester polyol and a structural unit derived from isocyanate having an alicyclic ring.

An acrylic rubber containing: an alkyl acrylate unit; a crosslinking monomer unit; a unit of a bifunctional monomer represented by the following formula (A-1):

##STR00001##

wherein n represents 1 to 9, R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents an alkanediyl group having 2 to 4 carbon atoms; and an ethylene unit, wherein the acrylic rubber has a toluene insoluble content of 4 to 40% by mass.

An acrylic rubber containing: an alkyl acrylate unit; a crosslinking monomer unit; a unit of a bifunctional monomer represented by the following formula (A-1):

##STR00001##

wherein n represents 1 to 9, R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents an alkanediyl group having 2 to 4 carbon atoms; and an ethylene unit, wherein the acrylic rubber has a toluene insoluble content of 4 to 40% by mass.

A crosslinkable rubber composition includes a carboxyl group-containing nitrile rubber (A); a carboxyl group-containing acrylic rubber (B); and a polyamine-based crosslinking agent (C), where a ratio of a weight of the carboxyl group-containing nitrile rubber (A) to a weight of the carboxyl group-containing acrylic rubber (B) is from 5:95 to 95:5. The carboxyl group-containing nitrile rubber (A) includes 5 to 60% by weight of α,β-ethylenically unsaturated nitrile monomer units, and α,β-ethylenically unsaturated monocarboxylic acid ester monomer units. The carboxyl group-containing nitrile rubber (A) has an iodine value of 120 or less.

A crosslinkable rubber composition includes a carboxyl group-containing nitrile rubber (A); a carboxyl group-containing acrylic rubber (B); and a polyamine-based crosslinking agent (C), where a ratio of a weight of the carboxyl group-containing nitrile rubber (A) to a weight of the carboxyl group-containing acrylic rubber (B) is from 5:95 to 95:5. The carboxyl group-containing nitrile rubber (A) includes 5 to 60% by weight of α,β-ethylenically unsaturated nitrile monomer units, and α,β-ethylenically unsaturated monocarboxylic acid ester monomer units. The carboxyl group-containing nitrile rubber (A) has an iodine value of 120 or less.

A (meth)acrylic copolymer of the present invention includes a constituent unit (B) derived from a polysiloxane block-containing polymerizable monomer (b) represented by Formula (b1). In Formula (b1), R.sup.30 represents a hydrogen atom or a methyl group, a represents an integer of 2 to 5, b represents a number of 0 to 50, c represents an integer of 0 to 18, d represents a number of 1 to 1000, e represents a number of 1 to 80, R.sup.31 to R.sup.39 each represents an alkyl group, an alkoxy group, a phenyl group, a substituted phenyl group, a phenoxy group, or a substituted phenoxy group.

A (meth)acrylic copolymer of the present invention includes a constituent unit (B) derived from a polysiloxane block-containing polymerizable monomer (b) represented by Formula (b1). In Formula (b1), R.sup.30 represents a hydrogen atom or a methyl group, a represents an integer of 2 to 5, b represents a number of 0 to 50, c represents an integer of 0 to 18, d represents a number of 1 to 1000, e represents a number of 1 to 80, R.sup.31 to R.sup.39 each represents an alkyl group, an alkoxy group, a phenyl group, a substituted phenyl group, a phenoxy group, or a substituted phenoxy group.

An aqueous dispersion of a hydrophobically-modified alkali-soluble multistage polymer useful as a thickener affording high thickening efficiency and an aqueous coating composition comprising such aqueous dispersion showing good stability after heat aging without compromising stability upon addition of colorants.