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.

The present invention relates to a latex composition for dip-forming including two different types of carboxylic acid modified-nitrile based copolymer latex, and a dip-formed article prepared therefrom having excellent durability for sweat, and having high tensile strength and elongation percentage. Accordingly, the latex composition for dip-forming has excellent tensile strength, elongation percentage, stress and durability, and is useful in industries requiring these, for example, a rubber glove industry and the like.

An environment-friendly impregnation solution includes in percentage by weight: 1-15% of blocked isocyanate, 0.5-10% of special amino resin, 10-50% of rubber latex, 1-5% of auxiliaries, and the balance of water, wherein the sum of the weight percentage of each component is 100%. A method for preparing the environment-friendly impregnation solution includes adding blocked isocyanate and auxiliary A into water and stirring uniformly to obtain Composition 1; adding auxiliary B into Composition 1 and stirring uniformly to obtain Composition 2; adding special amino resin into Composition 2 and stirring uniformly, then subjecting the same to grinding to obtain Composition 3; adding rubber latex into Composition 3 and stirring uniformly to obtain the environment-friendly impregnation solution, followed by packaging. The impregnation solution of the invention does not contain toxic and harmful substances such as formaldehyde and resorcinol, and the preparation method thereof is simple.

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

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 is a method for producing a latex comprising hollow resin particles each with a high void ratio and a method for producing hollow resin particles each with a higher void ratio. In the method for producing the latex: a suspension treatment of the mixture liquid which comprises a monomer, a crosslinkable monomer, an oil-soluble polymerization initiator, a fat/fatty oil, a hydrocarbon solvent, a suspension stabilizer and an aqueous medium is carried out to prepare a suspension comprising monomer drops; a polymerization reaction of the suspension is carried out to prepare a precursor composition which comprises precursor particles each having a hollow portion including the hydrocarbon solvent.

Provided are compositions and associated methods for producing elastomeric rubber gloves with improved strength and flexibility at desirable glove palm thicknesses. An example elastomeric rubber glove comprises a substrate formed from a composition comprising a synthetic rubber latex, and an ionic liquid. The ionic liquid may comprise a combination of one or more alkyl imidazole ionic salts. The composition may comprise one or more metal oxides, including at least one of zinc oxide, magnesium oxide, cadmium oxide, and aluminum oxide. The synthetic rubber latex compositions were found to yield a material with strength and flexibility characteristics comparable to natural latex gloves of a greater thickness. The described gloves may also be cured without the addition of Sulphur and other vulcanization or rubber accelerators, further reducing the risk of allergies and costs of production.

Provided is a method of producing a glove, the method including: (1) the step of immersing a glove forming mold in a liquid coagulant containing calcium ions so as to allow the coagulant to adhere to the glove forming mold; (2) the step of adjusting the pH to be 9 or higher using an ammonium compound or an amine compound and leaving a glove emulsion composition to stand with stirring; (3) the dipping step of immersing the glove forming mold, to which the coagulant has thus adhered in the step (1), in the glove emulsion composition; (4) the gelling step of leaving the glove forming mold, to which the glove emulsion composition has thus adhered, to stand at a temperature for a period that satisfy specific conditions; (5) the leaching step of removing impurities from a cured film precursor thus formed on the glove forming mold; (6) the beading step of, after the leaching step, winding the cuff portion of the resulting glove; (7) the precuring step of heating and drying the cured film precursor that has been subjected to the beading step; and (8) the curing step of heating the cured film precursor at a specific temperature for a specific period to obtain a cured film.

The method produces hollow resin particles. The method comprising steps of: preparing a mixture liquid comprising (A) a monomer comprising at least one monomer selected from the group consisting of a monovinyl monomer and a hydrophilic monomer excluding acrylonitrile and methacrylonitrile, (B) a crosslinkable monomer, (C) an oil-soluble polymerization initiator, (E) a hydrocarbon solvent, (F) a suspension stabilizer and (G) an aqueous medium; carrying out a suspension treatment of the mixture liquid to prepare a suspension; carrying out a polymerization reaction of the suspension to prepare a precursor composition; carrying out a solid-liquid separation of the precursor composition to obtain the precursor particles; and removing the hydrocarbon solvent (E) included in the precursor particles.