Unitika Ltd.

Kazushige Kojima

Koji Fujimoto

Sachiko Kokuryo

Tsuneo Tamura

Takaaki Matsuo

Keizo Kyuda

Izumi Yoshida

Mitsunobu Satoh

The present invention provides a polyamide resin composition in which silicate layers originating from a layered silicate and having the below-described property {circle around (1)} are uniformly dispersed on a molecular level in a polyamide resin to accomplish high strength, high modulus, high heat resistance, high toughness, excellent dimensional stability, and high tensile elongation with a small deviation. {circle around (1)}: average particle size from a photograph observation of transmission electron microscopy is 0.1 &mgr;m or less and not including a maximum particle size of 30 &mgr;m or higher.

Polyamide resin composition and process for producing the same

A polyamide resin composition comprising (A) a reinforced polyamide resin which comprises 100 parts by weight of a nylon 6 homopolymer or copolymer and 1 to 20 parts by weight of a layered silicate uniformly dispersed in the polymer on the molecular level and (B) a non-reinforced polyamide resin, a test specimen of said composition having a tensile weld strength of 45 MPa or higher and a flexural modulus of 4 GPa or higher.

Polyamide resin composition and molded articles

A process for forming an ultra-high molecular weight nylon 6 by polymerizing .epsilon.-caprolactam, which comprises heating substantially anhydrous .epsilon.-caprolactam at a temperature of from 100.degree. to 200.degree. C. in the presence of (a) a main catalyst selected from a Grignard compound and a halogenated magnesium lactamate, (b) a co-catalyst selected from an acyl lactam compound and an isocyanic acid ester and (c) at least one activator selected from the group consisting of amides, sulfoxides, thioethers and phosphoric esters. According to this inventive process, an ultra-high molecular weight nylon 6 can be produced within a short period of time, making use of industrially advantageous compounds which are stable in air, hardly dangerous and inexpensive. Being free from cross-linkings, the ultra-high molecular weight nylon 6 obtained by the process of this invention is soluble in various solvents and is useful as a starting material for the production of high strength and high modulus materials.

Anhydrous polymerization of caprolactam with catalyst, cocatalyst and

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Kyoto, Japan

Kazushige Kojima