A composite porous membrane contains at least one porous base layer and at least one uniaxially stretched coating layer located on at least one side surface of the porous base layer. For example, the composite porous membrane comprises at least one porous base layer and at least one nanofiber-like non-polyolefin polymer porous layer oriented along the transverse stretching direction of the composite porous membrane and located on one or two side surfaces of the porous base layer, or the composite porous membrane comprises a biaxially stretched polypropylene porous base layer and a uniaxially stretched coating layer located on at least one side surface of the porous base layer. The composite porous membrane is coated with a coating solution prior to transversely stretching. The nanofiber-like non-polyolefin polymer porous layer may reduce cracking of the composite porous membrane in the machine direction.

A composite porous membrane contains at least one porous base layer and at least one uniaxially stretched coating layer located on at least one side surface of the porous base layer. For example, the composite porous membrane comprises at least one porous base layer and at least one nanofiber-like non-polyolefin polymer porous layer oriented along the transverse stretching direction of the composite porous membrane and located on one or two side surfaces of the porous base layer, or the composite porous membrane comprises a biaxially stretched polypropylene porous base layer and a uniaxially stretched coating layer located on at least one side surface of the porous base layer. The composite porous membrane is coated with a coating solution prior to transversely stretching. The nanofiber-like non-polyolefin polymer porous layer may reduce cracking of the composite porous membrane in the machine direction.

The present invention aims to provide a method for improving the fluidity of a crystal nucleating agent for polyolefin resins without impairing other properties, and a polyolefin resin composition containing the crystal nucleating agent with improved fluidity and having excellent properties including transparency, and a molded article thereof. Adjustment to specific characteristics can improve the fluidity of a crystal nucleating agent for polyolefin resins, and the use of such a crystal nucleating agent having specific characteristics remarkably improves the workability during molding processing and provides a polyolefin resin composition excellent in properties such as transparency, and a molded article thereof.

The present invention aims to provide a method for improving the fluidity of a crystal nucleating agent for polyolefin resins without impairing other properties, and a polyolefin resin composition containing the crystal nucleating agent with improved fluidity and having excellent properties including transparency, and a molded article thereof. Adjustment to specific characteristics can improve the fluidity of a crystal nucleating agent for polyolefin resins, and the use of such a crystal nucleating agent having specific characteristics remarkably improves the workability during molding processing and provides a polyolefin resin composition excellent in properties such as transparency, and a molded article thereof.

A method for producing a resin composition of the present invention is a method for producing a resin composition, the method including a step of obtaining a resin composition by heating and melt-kneading a mixture containing a particulate nucleating agent in which D.sub.50 is equal to or more than 0.1 μm and equal to or less than 300 μm and a thermoplastic resin using a twin screw extruder (100) including, inside a cylinder (10), a screw (50) having kneading discs (60), in which the step of obtaining a resin composition includes an extrusion step of extruding the mixture supplied into the twin screw extruder (100) in an ejection direction under kneading conditions in which X and Y satisfy 4.0≤X in a range of 6.0×10.sup.3≤Y≤7.0×10.sup.4 when a volume-based ejection amount is denoted by X (10.sup.−6.Math.kg.Math.h.sup.−1.Math.mm.sup.−3), and a strain rate is denoted by Y (min.sup.−1).

Provided are: a nucleating agent capable of imparting excellent mechanical properties to a molded article; a resin composition; a method of producing a resin composition; and a molded article. The nucleating agent contains: (A) an aromatic phosphate metal salt having a structure represented by Formula (1) (wherein, R.sup.1 to R.sup.5 each independently represent a hydrogen atom or an alkyl group; n represents 1 or 2; when n is 1, M.sup.1 represents an alkali metal or dihydroxyaluminum; and when n is 2, M.sup.1 represents an alkaline earth metal, zinc, or hydroxyaluminum); and (B) a carboxylic acid metal salt having a structure represented by Formula (2) (wherein, M.sup.2 represents an alkali metal, an alkaline earth metal, hydroxyaluminum, or dihydroxyaluminum; a represents 1 or 2; x represents 1 or 2; a and x satisfy ax=2; and Z represents a group having a structure represented by Formula (3) or (4)).

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A package for contact lenses package having an ability to block ultraviolet and high energy visible wavelengths. The package has a transmissibility of less than 20% at wavelengths between 250 nm and 475 nm, and a transmissibility equal to or greater than 10% at the light wavelengths greater than 480 nm.

An extrusion composition containing at least one resin selected from the group consisting of polypropylene homopolymers, polypropylene random copolymers, and polypropylene impact copolymers. The extrusion composition also contains at least one benzoic acid salt-based nucleating agent provided in the composition at a use level of between about 0.01 and 0.15 parts by weight, in relation to 100 parts by weight of the resin and at least one co-additive selected from the group consisting of poly(ethylene glycol) and copolymers containing segments of ethylene oxide, wherein the co-additive has a number average molecular weight of about 300 or more, and wherein the use level of the co-additive is about 0.005 parts by weight or more, in relation to 100 parts by weight of the resin.

Provided are: an additive composition capable of imparting excellent mechanical properties to a molded article; a resin composition containing the same; a method of producing the resin composition; and a molded article. The additive composition contains: (A) a nucleating agent; (B) a hydroxy group-containing fatty acid lithium salt; and (C) a hydrotalcite. In this additive composition, the (A) nucleating agent contains an organic oxoacid metal salt, the content of the (B) hydroxy group-containing fatty acid lithium salt is 25 to 400 parts by mass with respect to 100 parts by mass of the (A) nucleating agent, and the content of the (C) hydrotalcite is 25 to 400 parts by mass with respect to 100 parts by mass of the (A) nucleating agent.

Provided are: an additive composition capable of imparting excellent mechanical properties to a molded article; a resin composition containing the same; a method of producing the resin composition; and a molded article. The additive composition contains: (A) a nucleating agent; (B) a hydroxy group-containing fatty acid lithium salt; and (C) a hydrotalcite. In this additive composition, the (A) nucleating agent contains an organic oxoacid metal salt, the content of the (B) hydroxy group-containing fatty acid lithium salt is 25 to 400 parts by mass with respect to 100 parts by mass of the (A) nucleating agent, and the content of the (C) hydrotalcite is 25 to 400 parts by mass with respect to 100 parts by mass of the (A) nucleating agent.