摘要:
Organopolysiloxane compositions suitable for use in a liquid injection molding process of elastomeric articles are produced by mixing a vinyl-endblocked polydiorganosiloxane fluid copolymer containing dimethylsiloxane units and methyl-3,3,3-trifluoropropylsiloxane units, a treated, reinforcing silica filler, a platinum-containing catalyst, a curing agent comprising dimethylhydrogensiloxane units as the only source of silicon-bonded hydrogen atoms and, as an inhibitor for the platinum-containing catalyst, certain olefinic siloxanes and/or acetylenic siloxanes. These compositions are especially suited for liquid injection molding because they can be stored at room temperature for days and can be injected into a hot mold with pressures less than 352 kg./sq.cm. (5,000 psi) whereon they cure rapidly to an elastomeric article having a tensile strength greater than 42 kg./sq.cm., and elongation at break greater than 300 percent and a tear strength greater than 7 kg./cm.
摘要:
Mixing a hydroxyl endblocked polydiorganosiloxane, an organohydrogensiloxane, a platinum catalyst and a platinum catalyst inhibitor where the inhibitor is present in an amount of 0.0001 to 0.001 moles of inhibitor per 100 grams of hydroxyl endblocked polydiorganosiloxane and thereafter allowing the resulting mixture to cure, provides an elastomer.
摘要:
Continuously passing a mixture of an acetylenic alcohol and a siloxane compound having at least three silicon-bonded hydrogen atoms bonded to at least three different silicon atoms in the presence of a platinum catalyst through a heating means wherein the mixture is heated above 100.degree.C. and above the temperature at which the olefinic siloxane compound product is no longer an inhibitor for the reaction and wherein the reactants and products are maintained under sufficient pressure to keep the mixture in a liquid state at least until the mixture has passed through the heating means provides an olefinic siloxane compound which, below 100.degree.C, is an inhibitor for the reaction between the acetylenic alcohol, the siloxane compound having at least three silicon-bonded hydrogen atoms in the presence of platinum.
摘要:
The present invention relates to the composition, preparation, and use of multi-layer composite films comprising a core layer of low gas permeable material, two intermediate layers sandwiching the core layer, and two outer layers sandwiching the two intermediate layers. The core layer provides the excellent oxygen barrier property, whereas the intermediate and outer layers protect the core layer so the oxygen permeability of the resulting multi-layer composite film becomes independent on relative humidity.
摘要:
The present invention relates to the composition, preparation, and use of multi-layer composite films comprising a core layer of low gas permeable material, two intermediate layers sandwiching the core layer, and two outer layers sandwiching the two intermediate layers. The core layer provides the excellent oxygen barrier property, whereas the intermediate and outer layers protect the core layer so the oxygen permeability of the resulting multi-layer composite film becomes independent on relative humidity.
摘要:
The present invention relates to the composition, preparation, and use of multi-layer composite films comprising a core layer of low gas permeable material, two intermediate layers sandwiching the core layer, and two outer layers sandwiching the two intermediate layers. The core layer provides the excellent oxygen barrier property, whereas the intermediate and outer layers protect the core layer so the oxygen permeability of the resulting multi-layer composite film becomes independent on relative humidity.
摘要:
A composite films which exhibit low oxygen transmission rates. The film comprises a silane resin coated on a plastic substrate then cured by ultraviolet radiation. For the silane coating, this invention relies on a class of organosilicon compounds derived from 1) organohydrogensilanes or organohydrogensiloxanes and 2) propargyl esters of carboxylic acids containing a terminal aromatic hydrocarbon radical, where the carbopropynoxy group of the ester and the aromatic hydrocarbon radical are separated by at least two adjacent ethylenically unsaturated carbon atoms. If more than two of these carbon atoms are present they form a sequence of conjugated ethylenic double bonds which allows the polymer to cross-link upon exposure to ultraviolet radiation.
摘要:
The present invention provides microencapsulated liquid or solubilized curing catalysts for one-part heat curable organosiloxane compositions. The curing catalysts are prepared by the photoinitiated polymerization of at least one solubilized hydroxyl-containing ethylenically unsaturated organic compound in the presence of a photoinitiator for the polymerization of said compound, an optional surfactant, and a liquid or solubilized curing catalyst for organosiloxane compositions. The curing agent is in the form of coordination complex with an ethylenically or acetylenically unsaturated organic compound and the solvent for the polymerization reaction is a mono- or polyhydric alcohol. At least a portion of the present 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.
摘要:
Compositions which cure by UV radiation in less than one second are obtained by mixing an alkenyl containing polydiorganosiloxane, a mercapto functional crosslinker of the mercapto functional polyorganosiloxane or mercapto organic compounds, a photosensitizer, a viscosity stabilizer, and optionally a reinforcing agent. These compositions can be packaged in one container and can be used as the primary coating for optical fibers.
摘要:
Adhesive compositions comprising blends of polyethylene oxide-grafted silicone polymers with resinous copolymers are disclosed. The adhesive compositions enhance release, in a controlled fashion, of bioactive or chemical agents blended or otherwise dispersed through the compositions. Transdermal drug delivery devices incorporating the adhesive compositions are also disclosed.