A rubber composition based on at least one diene elastomer, a reinforcing filler predominantly comprising a filler covered at least partially by silica and a crosslinking system. The dispersion of the filler in the elastomeric matrix has a Z score greater than or equal to 70, and the composition is devoid of agent for coupling the filler with the elastomer.

The invention relates to a method for the manufacture of a prophylactic article, especially of a glove, from a (carboxylated) diene rubber, according to which a layer of a (carboxylated) diene latex is applied on a former and the (carboxylated) diene latex is cross-linked with a cross-linking agent, which is immobilized on inorganic and/or organic particles with formation of modified particles, and the modified particles are added to the (carboxylated) diene latex.

A method for producing a latex composition, the method comprising a provision step of providing a conjugated diene polymer latex; and a preparation step of adding a sulfur-based vulcanizing agent, a xanthogen compound, and a strong acid salt-based surfactant to the conjugated diene polymer latex to prepare a latex composition.

A method for producing a latex composition, the method comprising a provision step of providing a conjugated diene polymer latex; a preparation step of adding a sulfur-based vulcanizing agent and a xanthogen compound to the conjugated diene polymer latex to prepare a latex composition before aging; and an aging step of, after the preparation of the latex composition before aging, aging the prepared latex composition before aging through storing of the latex composition at a temperature of 5 to 60° C. for 12 hours to 14 days, wherein the pH of the latex composition after 12 hours from the start of aging in the aging step is controlled to 9 or more.

A method of producing a packaging structure, including the steps: coating at least one surface of a first sheet base material and/or a second sheet base material with a synthetic polyisoprene latex having a weight average molecular weight of 500,000 -5,000,000 and/or a styrene-isoprene-styrene block copolymer having a weight average molecular weight of 100,000-300,000, sandwiching an article to be packaged in a state wherein the first and second sheet base material are in contact with each other via a latex coated surface formed on the first and/or second sheet base material to thereby obtain a laminated body, pressing a portion where at least the first and second sheet base material of the laminated body are in contact with each other via the latex coated surface at a temperature of 100° C. or less to thereby obtain a pressed laminated body, and performing a sterilization treatment on the pressed laminated body.

A latex of an acid-modified conjugated diene polymer including the acid-modified conjugated diene polymer obtained by modifying a conjugated diene polymer with an acid group-containing compound, in which a content of a structural unit derived from the acid group-containing compound is 0.2 to 0.7 parts by weight with respect to 100 parts by weight of the acid-modified conjugated diene polymer; a content of a water-soluble polymer in the latex is 2 parts by weight or less with respect to 100 parts by weight of the acid-modified conjugated diene polymer; when a solids content of the latex is adjusted to 60 wt %, a viscosity at 25° C. is 800 mPa.Math.s or less; and when the solids content of the latex is adjusted to 50 wt %, the viscosity at 25° C. is 300 mPa.Math.s or less.

A peroxide formulation includes at least one peroxide and at least one compound having a secondary amine group selected from amino acids, such as arginine, folic acid, and polyethyleneamines. The peroxide formulation is capable of curing an aqueous elastomer such as a latex in the full or partial presence of oxygen. Methods of using the peroxide formulation include dip-molding latex elastomer compositions.

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%.

Methods of vulcanization using a high content sulfur polymer, instead of elemental sulfur, have been developed. These high sulfur content polymers are referred to as Chalcogenide Hybrid Inorganic/Organic Polymers (CHIP) materials and have good polymer compatibility in that they are soluble in a number of polymers. Furthermore, CHIP materials may have weaker bonds than the S—S bonds of elemental sulfur and thus provide for a higher crosslinking efficiency vulcanization.