Storage stable heat curable organosiloxane compositions containing a microencapsulated catalyst and method for preparing said catalyst
US5194460A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 2, 1992 |
| Grant date | Mar 16, 1993 |
| Priority date | — |
| Expiry date | Jan 2, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2987
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention provides microencapsulated hydrosilylation catalysts for one-part heat curable organosiloxane compositions. Compositions containing these exhibit long-term storage stability yet cure rapidly when heated above the melting point of the encapsulating polymer. At least a portion of these microcapsules are less than one micron in diameter, and substantially all are less than about three microns in diameter. Compositions containing the preferred platinum group metals as catalysts are optically transparent. The microencapsulated curing catalysts of this invention are prepared by irradiating with UV light in the wavelength range of from 300 to 400 nanometers a solution containing (1) at least one of a specified group of photocrosslinkable organosiloxane compounds derived from propargyl esters of carboxylic acids containing a terminal aromatic hydrocarbon radical and at least two ethylenically unsaturated carbon atoms and (2) a liquid or solubilized hydrosilylation catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.