| 摘要 |
<p>1,247,503. Pressure-sensitive adhesive coatings. DOW CORNING CORP. 13 March, 1970 [14 April, 1969], No. 12129/70. Heading B2E. [Also in Division C3] A pressure-sensitive adhesive composition comprises (1) a methylphenylpolysiloxane resin having 0.5-0.8 phenyl groups and 1.45- 1.8 phenyl plus methyl groups per Si atom, and containing Si-bound OH groups, (2) a polysiloxane having at least 8 Si atoms, and 0.25-1.75 phenyl groups and 0.15-0.60 vinyl groups per Si atom, any other hydrocarbon groups being methyl groups, to a total of at least 1 hydrocarbon group per Si atom, (3) a compound having at least 2 Si atoms and at least 2 SiH groups per molecule, any other groups attached to Si being aromatic hydrocarbon or methyl groups or siloxane oxygen, and (4) a catalyst for the reaction between (2) and (3). The adhesive proper is the mixture obtained when (2) has been gelled by reaction with (3); a permanent bond is obtained when this mixture is heated to cure (1), optionally in the presence of a silanol condensation catalyst. In Examples (1) is a resin containing PhSiO 3 / 2, MeSiO 3/2 and Ph 2 SiO and/or Me 2 SiO and/or PhMeSiO units, and OH groups, with 0.6wt % of zinc octoate catalyst, (2) is a linear or non-linear polysiloxane containing phenyl and vinyl and optionally methyl groups, (3) is a copolymer of Me 2 SiO and MeHSiO units or an oligomeric linear or branched methylphenylhydrogen siloxane or disilahydrocarbon; and (4) is H 2 PtCl 6 . The compositions are applied to a polyimide tape, which is heated 3-4 mins at 170‹C to give an adhesive tape, which bonds to copper or aluminium sheet on heating for 2 hrs at 260‹C.</p> |
