Silicone pressure-sensitive adhesive process and product with improved lap-shear stability-I
US4584355A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1984 |
| Grant date | Apr 22, 1986 |
| Priority date | — |
| Expiry date | Oct 29, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/44
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention relates to silicone pressure-sensitive adhesives having improved viscosity stability, film physical property stability upon aging and lap shear stability (hold time) made by a method comprising the condensation of a benzene-soluble resin copolymer of 0.6 to 0.9 triorganosiloxy units per SiO.sub.4/2 unit which contains silicon-bonded hydroxyl radicals and a polydiorganosiloxane preferably containing silicon-bonded hydroxyl or other hydrolyzable endblocking radicals with a sufficient amount of an ammonia releasing endblocking agent containing endblocking triorganosilyl units such as hexamethyldisilazane to result in a 1:0.8 to 1:3 mole ratio of silicon-bonded hydroxyl radicals and hydrolyzable endblocking radicals to total moles of triorganosilyl units provided by the endblocking agent. The condensation is conducted with heating at 80.degree. C.-160.degree. C. in the presence of 0.5 to 10 moles of water per mole of .dbd.NH present in the endblocking agent and, when necessary, in the presence of an effective amount of an organic solvent such as xylene. Condensation is preferably conducted under solvent reflux conditions. When the condensation reaction is substantially c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.