An article comprises a laminate with a layer comprising a first latex composition containing a cross-linker component selected from sulfur, organic peroxide, vulcanizing activators, and vulcanizing accelerator; and a second layer comprising a second latex composition free of the cross-linker component. The laminate is formed by dipping a mold into the first latex composition then into the second latex composition forming a laminated film, then curing the laminated film by heating to a temperature between 90° C. to 140° C. Lastly, the laminated film is removed from the mold via inversion such that the second layer is inwards and the first layer is outwards.

An article comprises a laminate with a layer comprising a first latex composition containing a cross-linker component selected from sulfur, organic peroxide, vulcanizing activators, and vulcanizing accelerator; and a second layer comprising a second latex composition free of the cross-linker component. The laminate is formed by dipping a mold into the first latex composition then into the second latex composition forming a laminated film, then curing the laminated film by heating to a temperature between 90° C. to 140° C. Lastly, the laminated film is removed from the mold via inversion such that the second layer is inwards and the first layer is outwards.

A latex of a styrene-based block copolymer includes a styrene-based block copolymer and water. The styrene-based block copolymer includes a toluene insoluble content of 30 to 95 wt %. The latex of the styrene-based block copolymer is superior in the processability and can provide a molded film such as a dip-molded product having the high tear strength, the high stress retention and the soft texture.

A latex composition for dip molding includes a carboxylic acid-modified nitrile-based copolymer latex and a cholate-based emulsifier, wherein the cholate-based emulsifier is included in an amount of 0.02 to 3 parts by weight based on a solid content with respect to a solid content of 100 parts by weight of the carboxylic acid-modified nitrile-based copolymer latex. A method of preparing the latex composition for dip molding and a molded article produced using the same are also provided.

A method for producing a polymer latex includes: a preparation step of reducing the weight average molecular weight of a conjugated diene polymer (A) by 20 to 70 mass %, thereby obtaining an organic solvent solution containing a conjugated diene polymer (B) having a weight average molecular weight lower than that of the conjugated diene polymer (A); and an emulsification step of emulsifying the organic solvent solution in water in the presence of a surfactant, thereby obtaining a polymer latex.

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

Provided among other things is an elastomeric article providing a chemical barrier, the article having a layered structure comprising a sequential laminate of: (a) a latex-based elastomeric polymeric barrier layer; (b) a non-reactive tie adhesive resin layer comprising oxo (—(C═O)—) groups; and (c) a polyamide layer; wherein the layered structure has a first side nearest the latex-based elastomeric polymeric barrier layer and a second side; wherein the layered structure is effective to provide a chemical permeation time in excess of 100 minutes pursuant to EN 16523-1:2015 for benchmark solvents of acetone, ethyl acetate and methanol, when applied to the first side, and in excess of 100 minutes for acetone when applied to the second side; and wherein the elastomeric layer is primarily not polyolefin.

Provided among other things is an elastomeric article providing a chemical barrier, the article having a layered structure comprising a sequential laminate of: (a) a latex-based elastomeric polymeric barrier layer; (b) a non-reactive tie adhesive resin layer comprising oxo (—(C═O)—) groups; and (c) a polyamide layer; wherein the layered structure has a first side nearest the latex-based elastomeric polymeric barrier layer and a second side; wherein the layered structure is effective to provide a chemical permeation time in excess of 100 minutes pursuant to EN 16523-1:2015 for benchmark solvents of acetone, ethyl acetate and methanol, when applied to the first side, and in excess of 100 minutes for acetone when applied to the second side; and wherein the elastomeric layer is primarily not polyolefin.

The present technology provides a carboxylic acid-modified nitrile-based copolymer latex including a carboxylic acid-modified nitrile-based copolymer including a conjugated diene-based monomer-derived unit, an ethylenic unsaturated nitrile-based monomer-derived unit, and an ethylenic unsaturated acid monomer-derived unit, wherein the carboxylic acid-modified nitrile-based copolymer latex satisfies General Formula 1 and General Formula 2.

The present technology provides a carboxylic acid-modified nitrile-based copolymer latex including a carboxylic acid-modified nitrile-based copolymer including a conjugated diene-based monomer-derived unit, an ethylenic unsaturated nitrile-based monomer-derived unit, and an ethylenic unsaturated acid monomer-derived unit, wherein the carboxylic acid-modified nitrile-based copolymer latex satisfies General Formula 1 and General Formula 2.