A method for making an article from a silicone pressure sensitive adhesive composition

摘要

The present inventions relates to a method for making an article, comprising applying a layer of a silicone composition on at least a portion of at least one surface of a substrate, said silicone composition comprising the condensation reaction product of a silanol-functional silicone resin, said resin comprising M structural units according to the R 1 3 SiO 1/2 , wherein each R 1 is independently hydroxy or a monovalent hydrocarbon radical, and Q structural units according to the formula SiO 4/2 in a ratio of M units to Q units of less than 1.1:1, a silanolfunctional polydiorganosiloxane gum and a crosslinker, said silicone composition being obtained by a method comprising:
condensing, at an elevated temperature in the presence of a base catalyst, said silanol-functional silicone resin, and
(a) heating a mixture of the resin, gum, crosslinker, base catalyst an an organic solvent to a first elevated temperature to begin condensation of the resin, gum and crosslinker,
(b) adding a molar excess, based on moles of alkoxy groups of the resin, gum and crosslinker of the mixture of step (a), of water to the mixture of step (a),
(c) heating the mixture of step (b) to allow hydrolysis of any remaining alkoxy groups, and
(d) heating the mixture of step (c) to a second elevated temperature to drive condensation of the resin, gum and crosslinker toward completion.