Provided is a dip molding emulsion including, at least: an elastomer that contains a (meth)acrylonitrile-derived structural unit, an unsaturated carboxylic acid-derived structural unit, and a butadiene-derived structural unit in a polymer main chain; an epoxy crosslinking agent; water; and a pH modifier, in which dip molding composition the elastomer contains the (meth)acrylonitrile-derived structural unit in an amount of 20% by weight to 40% by weight, the unsaturated carboxylic acid-derived structural unit in an amount of 1% by weight to 10% by weight, and the butadiene-derived structural unit in an amount of 50% by weight to 75% by weight, and the epoxy crosslinking agent includes an epoxy crosslinking agent containing an epoxy compound having three or more epoxy groups in one molecule and has a dissolution rate in water of 10% to 70% as determined by a specific measurement method.

A latex for dip forming and a sulfur-based crosslinking agent, and has a pH of 9.5-11, the latex containing a copolymer having 40-80% by weight of conjugated diene monomer units (A) that contain a butadiene unit and an isoprene unit, 10-45% by weight of ethylenically unsaturated nitrile monomer units (B), and 2-15% by weight of ethylenically unsaturated acid monomer units (C), the ratio between the butadiene unit content and the isoprene unit content being 40:60 to 95:5 expressed in terms of weight.

Disclosed is a dip-formed article obtained by dip-molding a latex composition for dip-forming, which contains a crosslinking agent and a latex for dip-forming containing a copolymer composed of 40-80% by weight of conjugated diene monomer units (A) containing an isoprene unit, 20-45% by weight of ethylenically unsaturated nitrile monomer units (B), and 2-15% by weight of ethylenically unsaturated acid monomer units (C), and having a weight ratio of butadiene unit content to isoprene unit content that falls within the range of 60:40 to 100:0. Tear strength is at least 50 N/mm, tensile strength is at least 25 MPa, and oil swelling rate does not exceed 5%.

A method of preparing a carboxylic acid-modified nitrile-based copolymer latex is provided. The method of preparing a carboxylic acid-modified nitrile-based copolymer later includes emulsion-polymerizing a monomer mixture including a conjugated diene-based monomer, an ethylenically unsaturated nitrile-based monomer, and an ethylenically unsaturated acid monomer in the presence of a cross-linking agent including glyoxal.

A latex composition for dip molding having an excellent flow mark property and syneresis property and being capable of providing a molded article having excellent tensile properties and texture is provided. A method of preparing the latex composition, and a dip-molded article produced using the latex composition are also provided.

A method of the present invention for producing a carbon nanotube includes: a dispersing step of dispersing a carbon nanotube in a solvent by carrying out a dispersion treatment that brings about a cavitation effect, the carbon nanotube having an average diameter (Av) and a diameter distribution (3σ) that satisfy 0.60>3σ/Av>0.20; and a mixing step of mixing carbon nanotube slurry obtained in the dispersing step with latex.

This application relates to synthetic elastomeric articles, and gloves in particular, comprising the cured product of a synthetic latex composition, the synthetic latex composition comprising a synthetic carboxylated polymer and a cross-linking composition, the cross-linking composition comprising an aqueous solution of a negatively charged multivalent metal complex ion having a pH of at least 9.0. Also described are compositions for forming the articles, and methods for making the articles, based on the use of the described cross-linking composition. The articles so produced have an average thickness of 0.2 mm or less and a modulus at 500% of less than 6.5 MPa.

A latex composition for dip molding includes a carboxylic acid-modified nitrile-based copolymer latex having pKa of 9.5 to 10.2 and satisfying General Formulas 1 and 2.

0.85≤P≤1.0, P=CV.sub.D/CV.sub.0  [General Formula 1]

5≤M≤20, M=m.sub.1×m.sub.2  [General Formula 2] wherein CV.sub.0 represents a capillary viscosity which is measured in a swollen in a methyl ethyl ketone solvent, CV.sub.D represents a capillary viscosity in a deswollen state, m.sub.1 represents an insolubility of a dried film in the methyl ethyl ketone solvent, and m.sub.2 represents a swelling index of the dried film in the methyl ethyl ketone solvent, wherein a carboxylic acid-modified nitrile-based copolymer of carboxylic acid-modified nitrile-based copolymer latex includes: a conjugated diene-based monomer-derived unit, an ethylenic unsaturated nitrile-based monomer-derived unit, and an ethylenic unsaturated acid monomer-derived unit. A molded article having a layer derived from the latex composition is also provided.

Disclosed is a latex composition for dip molding including a carboxylic acid-modified nitrile-based copolymer latex satisfying General Formula 1, wherein the carboxylic acid-modified nitrile-based copolymer includes: 15 wt % to 30 wt % of the ethylenic unsaturated nitrile-based monomer-derived unit and 2.5 wt % to 4.5 wt % of the ethylenic unsaturated acid monomer-derived unit, and a molded article:

1.0 mm.sup.2/s≤CV.sub.0≤3.0 mm.sup.2/s.  General Formula 1

The present invention relates to methods for reprocessing elastomeric films or articles comprising an elastomer film wherein the elastomeric film is made from a polymer latex comprising: (a) particles of a carboxylated conjugated diene nitrile latex polymer (a) obtainable by free-radical emulsion polymerization of a mixture of ethylenically unsaturated monomers comprising: 15 to 99 wt.-% of conjugated dienes; 1 to 80 wt.-% of monomers selected from ethylenically unsaturated nitrile compounds; 0.05 to 10 wt.-% of ethylenically unsaturated carboxylic acids and/or salts thereof; 0 to 50 wt.-% of vinyl aromatic monomers; and 0 to 65 wt.-% of alkyl esters of ethylenically unsaturated acids, the weight percentages being based on the total monomers in the mixture in combination or association with (b) particles of a latex polymer (b) comprising at least one oxirane-functional group;
wherein the monomer composition of the latex polymer (a) is different from the monomer composition of the latex polymer (b) and to the use said polymer latex to make an elastomeric film obtained from said polymer latex self-healing, repairable and/or recyclable.