The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 09, 2025
Filed:
Oct. 22, 2020
Thai Nippon Rubber Industry Public Company Limited, Chonburi, TH;
Pathompong Chupayak, Chonburi, TH;
Theeraphol Piachan, Chonburi, TH;
Supparat Piachan, Chonburi, TH;
Brian Youichi Kempimook, Chonburi, TH;
Punyawat Chupayak, Chonburi, TH;
Waranyu Dararattanaroj, Chonburi, TH;
Dave Narasimhan, Flemington, NJ (US);
Sudarshan Narasimhan, Flemington, NJ (US);
Thai Nippon Rubber Industry Public Company Limited, Chonburi, TH;
Abstract
A synthetic polyisoprene latex emulsion has pre-vulcanization composition and post vulcanization composition. The pre-vulcanization composition comprises insoluble amorphous sulfur extracted with zinc dithiocarbamate catalyst at 20° C. to form sulfur chain and transported to interior of synthetic polyisoprene particle forming physical attachment of sulfur to active sites. The degree of pre-vulcanization is verified by expansion of cast and dried film of latex in toluene in 20 minutes by means of a swelling index test. The latex emulsion is vulcanized at 90° C. to 120° C. for 3 to 5 minutes. Post-vulcanization composition with accelerators crosslink between synthetic polyisoprene particles, uniformly curing both in the inter-particle and intra-particle regions to produce high cross link density, uniform distribution of double bonds with zinc segregation at the boundaries of original particles. The condom exhibits high tensile strength, tensile modulus, elongation with excellent tear strength releasing below 10 ppb of nitrosamines.