Title:
SYNTHETIC POLYISOPRENE LATEX CONDOMS WITH REDUCED NITROSAMINE
Document Type and Number:
Japanese Patent JP2022068874
Kind Code:
A
Abstract:
To provide a method for manufacturing highly elastic synthetic polyisoprene latex condoms with reduced nitrosamine.SOLUTION: A vulcanization composition comprises insoluble amorphous sulfur extracted with a zinc dithiocarbamate catalyst at 20°C to form a sulfur chain and transported to the interior of synthetic polyisoprene particles forming physical attachment of sulfur to active sites. The degree of 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. A post-vulcanization composition with accelerators crosslinks 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 and excellent tear strength, releasing below 10 ppb of nitrosamines.SELECTED DRAWING: None
Inventors:
PATHOMPONG CHUPAYAK
THEERAPHOL PIACHAN
SUPPARAT PIACHAN
BRIAN YOUICHI KEMPIMOOK
PUNYAWAT CHUPAYAK
WARANYU DARARATTANAROJ
DAVE NARASIMHAN
SUDARSHAN NARASIMHAN
THEERAPHOL PIACHAN
SUPPARAT PIACHAN
BRIAN YOUICHI KEMPIMOOK
PUNYAWAT CHUPAYAK
WARANYU DARARATTANAROJ
DAVE NARASIMHAN
SUDARSHAN NARASIMHAN
Application Number:
JP2021173439A
Publication Date:
May 10, 2022
Filing Date:
October 22, 2021
Export Citation:
Assignee:
THAI NIPPON RUBBER IND PUBLIC CO LTD
International Classes:
A61F6/04; C08C1/00; C08K5/39; C08L9/10
Foreign References:
| US20090272384A1 | 2009-11-05 | |||
| WO2019173863A1 | 2019-09-19 |
Attorney, Agent or Firm:
Hidewa Patent Office