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Matrix for release of active ingredients

  • US 4,908,208 A
  • Filed: 04/22/1988
  • Issued: 03/13/1990
  • Est. Priority Date: 04/22/1988
  • Status: Expired due to Fees
First Claim
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1. In a system for delivering an active substance to the atmosphere:

  • a matrix containing an active ingredient, said matrix comprising a substantially linear thermoplastic 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°

    C. and 160°

    C. said soft segments forming from about 70 to 99 percent by weight, based on the weight of said copolymer, said hard segments forming about 1 to 30 weight percent, based on the weight of said copolymer, the average molecular weight of said copolymer being between about 30,000 and 500,000, said active substance being an insect sex pheromone, a bactericide, an herbicide, a plant growth regulator, or an insect repellant.

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