Matrix for release of active ingredients
US4908208A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 1988 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Apr 22, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/61
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A matrix for delivery of active substances such as fragrances and pheromones into the atmosphere is provided which matrix is active substance permeable (including to hydrophilic substances) and is formed of a copolymer which can be softened sufficiently at temperature between 45.degree. C. and 160.degree. C. to incorporate the substances therein without damage caused by heat or chemical reactions, the matrix being formed of a substantially linear block copolymer which is a reaction product of a polydiorganosiloxane which forms soft segments in said reaction product and a diisocyanate which forms hard segments, said copolymer having a glass transition temperature between 45.degree. C. and 160.degree. C. said soft segments comprising from 70 to 99 percent by weight, based on the weight of said copolymer, the average molecular weight of the copolymer being between 15,000 and 500,000.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.