Abstract: The invention provides alkenyl-containing siloxane copolymers preparable by reacting: a compound (1) having at least three aliphatic double bonds, of the general formula R2(CR3═CH2)x  where R2 is a trivalent or tetravalent hydrocarbon of silane radical, and R3 is a hydrogen atom or an alkyl radical, with an organosiloxane having terminal Si-bonded hydrogen atoms, in the presence of a hydrosilylation catalyst, in a second step reacting: the resulting hydrocarbon-siloxane copolymers containing Si-bonded hydrogen atoms with &agr;,&ohgr;-dialkenylsiloxane polymer in the presence of a hydrosilylation catalyst, and, if desired, in a third step, equilibrating: the resulting alkenyl-containing siloxane copolymers with an organopolysiloxane from the group consisting of linear organopolysiloxanes containing terminal triorganosiloxy groups, linear organopolysiloxanes containing terminal hydroxyl groups, branched organopolysiloxanes with or without hydroxyl groups, cyclic organopolysiloxanes, and copol

Abstract: Alkoxy silane oligomers which have a non-hydrolyzable carbon bridged bond to another silane functionality are taught herein, as well as their manufacture and utility.

Abstract: A method for manufacturing an organic solvent-soluble hydrogenated octasilsesquioxane-vinyl group-containing compound copolymer comprising reacting 1 mol of (A) a hydrogenated octasilsesquioxane described by formula I with 0.2 to less than 3 mol of (B) a divinyl group-containing compound described by formula (2) CH2═CH—L—CH═CH2   Formula 2 where L is selected from the group consisting of (a) a divalent hydrocarbon group comprising 3 to 10 carbon atoms and (b) —(SiR2O)m—SiR2—, where each R is independently selected from the group consisting of alkyls comprising 1 to 6 carbon atoms and aryls comprising 6 to 9 carbon atoms and 1≦m≦10; in the presence of a hydrosilylation catalyst.

Abstract: An organopolysiloxane adhesive contains an organopolysiloxane rubber base, an organopolysiloxane pressure sensitive adhesive, a aliphatic unsaturated-functional M′Q resin, and a polyhydrido-functional organopolysiloxane in an organic solvent, and exhibits differential adhesion between dental impression material and dental impression tray material.

Abstract: A method for the preparation of hydrophilic silica gels with high pore volume. In the preferred method a hydrophilic silica hydrogel treated with an organosilicon compound to effect hydrophobing of the silica hydrogel is heated in the presence of an oxidizing atmosphere to a temperature sufficient to reduce the hydrophobicity imparted by the surface treatment thereby producing a hydrophilic silica gel having high pore volume.

Abstract: A curable silicone wire and cable coating composition with improved flame resistance at heat flux rates of 50 to 90 kW/m2, made by mixing ingredients comprises: (A) 30 to 90 weight percent of a heat-curable non-halogenated organosiloxane polymer, containing at least 2 alkenyl groups per molecule, (B) 1 to 65 weight percent of a reinforcing silica filler, based on the total composition, (C) 5 to 70 weight percent wollastonite having an average particle size of 2 to 30 &mgr;m, based on the total composition, and (D) curing component sufficient to cure the composition.

Abstract: A precursor composition includes (1) at least one crosslinking compound represented by the formula: wherein: u and x are independently selected positive integers, v and w are independently selected integers greater than or equal to zero, R1, R2, R3, R4, R5, R6, R7 and R8 are independently selected from the group consisting of alkyl, aryl, alkylaryl, haloalkyl, haloaryl and mixtures thereof; A and E are independently selected from the group consisting of O, an aliphatic bridge, an aryl bridge and mixtures thereof; and R9 and R10 are unsubstituted or substituted vinyl or ethynyl groups, (2) at least one organosilicon compound containing at least two silicon hydride moieties per molecule, and (3) a hydrosilation catalyst, A cross-linked polymer is formed by reacting the crosslinking compound of formula I with the organosilicon compound via a hydrosilation reaction. A thermoset polymer is formed by thermally curing the crosslinked polymer.

Abstract: The present invention relates to a foam control composition and to its use in foaming systems. More particularly, this invention relates to a foam control composition comprising a polysiloxane and a resin-filler made from MQ resins having at least one polyoxyalkylene group. The compositions of this invention exhibit excellent defoam effects and antifoam persistency.

Abstract: A silicone composition for preparing a silicone pressure sensitive adhesive, the composition comprising (A) 20 to 55 parts by weight of a polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule; (B) 45 to 80 parts by weight of an organopolysiloxane resin consisting essentially of R33 SiO1/2 units and SiO4/2 units, wherein the total amount of components (A) and (B) is 100 parts by weight; (C) an organohydrogenpolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule in an amount sufficient to cure the composition; (D) 25 to 200 parts by weight of a silica filler having an average surface area less than 25 m2/g; and (E) a catalytic amount of a hydrosilylation catalyst. Each R3 is independently selected from the group consisting of monovalent hydrocarbon and monovalent halogenated hydrocarbon groups. The mole ratio of R33SiO1/2 units to SiO4/2 units in the organopolysiloxane resin is from 0.6:1 to 1.

Abstract: Curable organopolysiloxane compositions comprising a platinum catalyst selected from the group consisting of (PR23)2Pt(—C≡C—R3)2  (III), (R22P—R4—PR22)Pt(—C≡C—R3)2  (IV) and H—C≡C—R5—C≡C—[—Pt(PR23)2—C≡C—R5—C≡C—]e—H  (V) where R2, R3, R4, R5 and e are as defined in claim 1.

Abstract: A silicone gel composition, (A) 100 parts by weight of a first polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule and having a viscosity of from 0.2 to 10 Pa·s at 25° C.; (B) at least about 0.5 part by weight of a second polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule, wherein the second polydiorganosiloxane has a viscosity at 25° C. of at least four times the viscosity of the first polydiorganosiloxane at 25° C.; (C) an organohydrogensiloxane having the average formula R7Si(SiOR82H)3 wherein R7 is an alkyl group having 1 to 18 carbon atoms or aryl, R8 is an alkyl group having 1 to 4 carbon atoms, in an amount sufficient to provide from 0.1 to 1.5 silicon-bonded hydrogen atoms per alkenyl group in components (A) and (B) combined; and (D) a hydrosilylation catalyst in an amount sufficient to cure the composition.

Abstract: A linear polyfluoro compound having at least two alkenyl groups as a base component is blended with a linear polyfluoro compound having one alkenyl group and a hydrosilyl-bearing linear polysiloxane having fluoroalkyl substituents in side chains and at ends thereof. With a platinum catalyst added, there is obtained a curable composition having improved storage stability which will quickly cure into satisfactory gel products.

Abstract: A silicone composition comprising (A) 100 parts by weight of a polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule; (B) 75 to 150 parts by weight of an organopolysiloxane resin having a number-average molecular weight of from 2,000 to 5,000 and consisting essentially of R.sup.3.sub.2 R.sup.4 SiO.sub.1/2 units and SiO.sub.4/2 units wherein each R.sup.3 is independently selected from the group consisting of monovalent hydrocarbon and monovalent halogenated hydrocarbon groups free of aliphatic unsaturation, R.sup.4 is selected from the group consisting of R.sup.3 and alkenyl, the mole ratio of R.sup.3.sub.2 R.sup.4 SiO.sub.1/2 units to SiO.sub.4/2 units is from 0.6:1 to 1.1:1, and the resin contains an average of from 2.5 to 7.

Abstract: A silicone composition for preparing a silicone pressure sensitive adhesive, the composition comprising (A) 20 to 55 parts by weight of a polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule; (B) 45 to 80 parts by weight of an organopolysiloxane resin comprising R.sup.3.sub.3 SiO.sub.1/2 units and SiO.sub.4/2 units wherein each R.sup.3 is independently selected from the group consisting of monovalent hydrocarbon and monovalent halogenated hydrocarbon groups, the mole ratio of R.sup.3.sub.3 SiO.sub.1/2 units to SiO.sub.4/2 units is from 0.6:1 to 1.

Abstract: A heat fixing roll includes a silicone rubber layer on a cylindrical metal mandrel having a penetration of at least 10 according to ASTM D1403 and a fluoroplastic layer thereon. The silicone rubber layer is obtained by molding and curing an addition reaction type liquid silicone rubber composition to the mandrel. The roll provides a sufficient nip width under low pressure, improved abrasion resistance, long-lasting toner release, and a satisfactory fixing function even at a high speed over a long period of time.

Abstract: The invention describes crosslinkable compositions comprising(1) organosilicon compounds which contain radicals having aliphatic carbon-carbon multiple bonds,(2) organosilicon compounds having Si-bonded hydrogen atoms or, in place of or in addition to (1) and (2); said composition further comprising(3) organosilicon compounds which contain radicals having aliphatic carbon-carbon multiple bonds and Si-bonded hydrogen atoms,(4) catalysts which promote the addition of Si-bonded hydrogen to aliphatic multiple bonds, and ##STR1## where R.sup.1 and R.sup.2 are as defined in claim 1, and X is a radical of the formula --OH, --Cl, --Br and --CN, with the radical --OH being particularly preferred.

Abstract: Crosslinkable compositions comprise novel organosilicon compounds (B.sup.1) containing Si-bonded hydrogen atoms and comprising(a) units of the formulaH.sub.a R.sub.2-a SiO.sub.2 O.sub.2/2 (I),where R is as defined in claim 1 and a is 0, 1 or 2, with the proviso that at least 20 mol % of the units of the formula (I) are ones in which a is 1 or 2,(b) carbostructural units G (II), where G are identical or different and are each a trivalent to decavalent aliphatic hydrocarbon radical having from 7 to 30 carbon atoms per radical, which may contain one or more heteroatoms selected from the group consisting of oxygen, boron, silicon, tin or titanium, with the proviso that at least three Si atoms are connected to one another via G,(c) units of the formula ##STR1## where b is 0, 1 or 2, with the proviso that b in formula (III') is not 2 and with the proviso that the units of the formula (III) or (III') are connected via the Si atoms to the carbostructural units G and(d) units of the formulaH.sub.c R.sub.3-c SiO.sub.

Abstract: This invention relates to resin-fillers and compositions containing the resin-fillers. Resin-fillers are the reaction product of a resin having monofunctional siloxane (M) units and tetrafunctional siloxane (Q) units, chemically linked to a crosslinker by addition reaction. The resin-fillers have properties more similar to those of silica fillers and less like those of conventional MQ resins. The resin-fillers are insoluble in solvents, form homogeneous blends with silicone polymers, and dramatically impact modulus and viscosity of a polymer even at low (e.g. 5 to 10 wt %) loading.

Abstract: An ultra-high molecular weight MQ resin and a method for its preparation are disclosed. The ultra-high molecular weight MQ resin has weight average molecular weight of at least 100,000, and the ultra-high molecular weight MQ resin is soluble in organic solvents.

Abstract: Novel rubber-modified rigid silicone resins are disclosed. The novel resins are the copolymerized reaction product of (A) an organosilicon composition selected from the group consisting (I) an organosilicone resin, (II) hydrolyzable precursors of (I), and an hydrolyzate of (II), (B1) a first silicone rubber having a nonfunctional linear chain length between functional groups from 6 to 100 and (B2) a second silicone ruberr having terminal functional groups and a degree of polymerization from about 200 to 1,000. The novel rubber-modified rigid silicone resins of the invention show remarkably high fracture toughness, K.sub.Ic, and critical strain energy release rate G.sub.Ic.

Abstract: More than about 9/10 (by weight as a platinum group metal atom) of the necessary amount of a platinum group metal catalyst enclosed in a compound having a melting or softening point of 40-200.degree. C., less than about 1/10 (by weight as a platinum group metal atom) of the necessary amount of a platinum group metal catalyst, and an addition reaction retarder are blended in an organopolysiloxane composition comprising an organopolysiloxane containing alkenyl or hydroxyl radicals and an organohydrogenpolysiloxane. The composition has improved shelf stability, an increased pot life, good curing capability, and fast curing upon heating.

Abstract: The invention relates to organopolysiloxanes which have aliphatically unsaturated radicals, are soluble to at least 80 wt % in organic solvents selected from xylene and toluol at a temperature of 25.degree. C. and a pressure of from 900 to 1100 hPa and contain at least one unit of the following formula (I) R.sup.1.sub.a R.sub.2-a SiO.sub.2/2, at least one unit of the following formula (II) R.sup.1.sub.b R.sub.3-b SiO.sub.1/2, at least one unit of the following formula (III) O.sub.1/2 R.sub.2 SiO.sub.x YRSiO.sub.2/2, and optionally at least one unit of the following formula (IV) O.sub.1/2 R.sub.2 SiO.sub.x YR.sub.2 SiO.sub.1/2, in which:R can be identical or different and is a monovalent, substituted or unsubstituted, SiC-bonded, aliphatically saturated hydrocarbon radical.R.sup.1 can be identical or different and is a monovalent, SiC-bonded, substituted or unsubstituted, aliphatically unsaturated hydrocarbon radical,a is 0, 1 or 2,b is 0, 1, 2 or 3,x is 0 or 1 andy is a radical --(CR.sup.3.sub.2).sub.n CHR.

Abstract: A silicone rubber composition comprises a silicone rubber and porous inorganic fine powders holding dimethyl-silicone oil.

Abstract: The present invention relates to electrically conductive silicone compositions comprising an organopolysiloxane containing at least two alkenyl groups per molecule, an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule, a platinum group metal containing catalyst, a conductive metal particulate, a precrosslinked elastomeric silicone particle, and a non-reactive volatile diluent. The electrically conductive silicone compositions of this invention are useful as electrically conductive adhesives and coatings for electrical and electronic devices. The cured electrically conductive silicone compositions of this invention have high electroconductivity and rubbery elasticity.

Abstract: This invention relates to a silicone release coating comprising (A) an organopolysiloxane having at least two crosslinkable carbon-carbon double bonds in each molecule, (B) an organopolysiloxane having at least two Si-bonded hydrogen atoms in each molecule, (C) a silylated polymethylsilsesquioxane and (D) platinum catalyst. The silicone release coating compositions of this invention can further comprise an inhibitor. The silicone release coating compositions of this invention do not decline in release resistance due to release paper aging or release liner aging.

Abstract: There is proposed a method of forming an insulating film pattern, which enables an insulating pattern of high precision and low dielectric constant to be easily obtained by means of an alkali development with basic solution. This method comprises the steps of coating a photosensitive composition comprising a first silicone polymer having a specific monomer and a second silicone polymer having a specific monomer on a substrate thereby to form a film of photosensitive composition, selectively exposing the film of photosensitive composition, alkali-developing the exposed film to form a pattern, and heat-treating the pattern of the photosensitive composition film.

Abstract: A high voltage electrical insulator formed from a curable liquid silicone rubber composition, and subsequently cured, a composition consisting essentially of(A) 100 weight parts of a fluid mixture of polyorganosiloxane comprising(a) at least 5 weight percent of a polyorganosiloxane resin comprising repeating units selected from the group consisting of SiO.sub.4/2 and RSiO.sub.3/2, where R is a monovalent hydrocarbon group, and(b) polydiorganosiloxane having a viscosity in the range from about 100 mPa.multidot.s to 100,000 mPa.multidot.s, that contains at least 2 silicon-bonded alkenyl groups in each molecule,(B) 1 to 100 weight parts microparticulate silica,(C) polyorganohydrogensiloxane that contains at least 2 silicon-bonded hydrogen atoms in each molecule, in a quantity that provides a value from 0.

Abstract: An alkenyl-functional silylated polymethylsilsesquioxane that contains no more than 0.12 residual silanol per Si atom and is obtained by silylating the silanol in starting polymethylsilsesquioxane. The starting polymethylsilsesquioxane has a predetermined number average molecular weight, Mn, from 380 to 2,000 and is represented by the general formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.mwherein m and n are positive numbers that provide the predetermined Mn, with the proviso that the value of m/(m+n) is less than or equal to 0.152/(Mn.times.10.sup.-3)+0.10 and greater than or equal to 0.034/(Mn.times.10.sup.-3). The alkenyl-functional silylated polymethylsilsesquioxane has the formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.m-k (CH.sub.3 Si(OSiR.sup.1 R.sup.2 R.sup.3)O.sub.2/2).sub.kwherein k is a positive number smaller than A, (m-k/(m+n) is less than or equal to 0.12, and R.sup.1, R.sup.2 and R.sup.

Abstract: An organopolysiloxane composition that can be crosslinked by addition, comprisinga) a branched organopolysiloxane having unsaturated hydrocarbon groups, and triorganosiloxy end unitswherein at least 90% of the organo groups are methyl groups,the number average molecular weight of which is on average from 9,000 to 60,000,wherein the ratio of the number of diorganosiloxy units (D-units) to the number of branch points is on average between 15 and 40, andwherein at least one triorganosiloxy unit (M-unit) and at maximum half of all the M-units are free of unsaturated radicals, the remaining M-units each have only one unsaturated radical and the content of unsaturated radicals is from 0.

Abstract: The invention relates to aliphatically unsaturated organosilicon compounds having 2 to 17 silicon atoms, to processes for their preparation and to their use in crosslinkable organopolysiloxane compositions, especially in compositions which can be crosslinked peroxidically or by hydrosilylation.

Abstract: A curable silicone composition cures to form a silicone cured product with improved fire-retarding properties. The composition comprises a hydrosilylation-reaction curable silicone composition Fire-retarding properties are imparted to the composition using a silica powder with a specific surface area of not less than 50 sq. m/g and a diamine compound. The cured product is preferably a silicone gel.

Abstract: A highly productive process for preparing cured silicone powder having a uniform particle size, in which a platinum-alkenylsilozane complex catalyst is added to a water-based dispersion of a silicone composition. The silicone composition is (i) an organopolysiloxane having at least two silicon-bonded alkenyl groups in each molecule, and (ii) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule. The catalyst is added and dispersed in the form of liquid particles with an average particle size in volumetric particle size distribution in water of no more than one micron.

Abstract: A curable silicone composition cures to form a silicone cured product with improved fire-retarding, properties. The composition comprises a hydrosilylation-reaction curable silicone composition. Fire-retarding properties are imparted to the composition by using an additive comprising tetrafunctional and monofunctional siloxane units and a diamine compound. The silicone cured product is preferably a silicone gel.

Abstract: Improved very high viscosity (putty) two component polymerizable polyorganosiloxane composition for use in making dental impressions, having improved tear strength, handling and wettability. Improved tear strength results from inclusion of a quadri-functional polysiloxane having a vinyl content of 0.16 to 0.24 m-mole/g. Working time is maintained by including sufficient amounts of a retarder composition that delays onset of the vinyl polymerization. Handling is improved by the addition of a very high viscosity linear vinyl terminated polydimethylsiloxane which reduces tackiness and improves the shelf stability. Wettability is improved by including a surfactant resulting in a surface contact angle with water at three minutes of less than 50.degree.. The surfactant chosen has an HLB of 8-11, such that the wetting contact angle is achieved within less than two minutes and remains wetting throughout the working time of the impression taking, substantially improving the impression making process.

Abstract: There is disclosed a curable resin composition that has an excellent fluidity prior to curing and that cures to form a molding resin that is flexible, highly moisture resistant, and strongly resistant to heat shock, said composition comprising(A) 100 weight parts of a curable resin; and(B) 0.1 to 500 weight parts of an epoxy group-containing silicone resin that has the general formula(R.sup.1 SiO.sub.3/2).sub.a (R.sup.2 R.sup.3 SiO.sub.2/2).sub.b (SiO.sub.4/2).sub.cwherein R.sup.1, R.sup.2 and R.sup.3 each represents a group selected from the group consisting of an epoxy group-containing organic group and a monovalent hydrocarbon group with the proviso that said epoxy group-containing organic groups comprise 0.1 to 40 mole percent of the total silicon-bonded organic groups in said silicone resin (B), a is a positive number, b is zero or a positive number, c is zero or a positive number, b/a has a value of zero to 10, c/(a+b+c) has a value of zero to 0.

Abstract: Curable organosiloxane compositions that cure by a platinum group metal catalyzed hydrosilation reaction to yield machinable elastomers exhibiting a high resistance to erosion contain an alkenyl-functional organosiloxane copolymer as the reinforcing agent together with quartz and organic or inorganic microspheres as the non-reinforcing filler. The concentration and density of the microspheres are preferably within specified limits.

Abstract: Acetylenic maleates, fumarates and related derivative compounds are new compositions of matter having the formula:R.sub.1 O.sub.2 C--CH.dbd.CH--CO.sub.2 R.sub.2wherein R.sub.1 may be an organic moiety containing at least two carbon atoms triply bonded one to the other as:--C.tbd.C--and R.sub.2 may be hydrogen, an organic moiety, or R.sub.1 ; suitable for use as liquid injection molding inhibitors either singly or in combination with themselves or other liquid injection molding inhibitors when used for the process of liquid injection molding curable compositions enabling an increase in the size of articles manufactured therefrom, which new compositions of matter cure into the polymerizable or curable resins thereby creating new compositions of matter as cured resins from which said articles of manufacture are produced.

Abstract: A solventless curable silicone release composition contains (A) a branched organopolysiloxane having a vinyl group attached to a silicon atom at an end of its molecular chain, (B) an organohydrogenpolysiloxane having at least three SiH groups in a molecule, and (C) a platinum group metal catalyst. The composition is easily applicable to a thin gage and cures into a releasable silicone coating ensuring light release at high speeds. A release sheet having the cured coating formed thereon has improved release characteristics.

Abstract: A hydrogen-functional silylated polymethylsilsesquioxane that contains no more than 0.12 residual silanol per Si atom and is obtained by silylating the silanol in starting polymethylsilsesquioxane. The starting polymethylsilsesquioxane has a predetermined number average molecular weight, Mn, from 380 to 2,000 and is represented by the general formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.mwherein m and n are positive numbers that provide the predetermined Mn, with the proviso that the value of m/(m+n) is less than or equal to 0.152/(Mn.times.10.sup.-3)+0.10 and greater than or equal to 0.034/(Mn.times.10.sup.-3). The hydrogen-functional silylated polymethylsilsesquioxane has the formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.m-k (CH.sub.3 Si(OSiR.sup.1 R.sup.2 R.sup.3)O.sub.2/2).sub.kwherein k is a positive number smaller than m, (m-k/(m+n) is less than or equal to 0.12, and R.sup.1, R.sup.2, and R.sup.

Abstract: Substantially branched alkenyl silicone polymer compositions having on average at least two branching points per molecule provide laminate release compositions that provide releasable laminates against methyl and phenyl silicone pressure sensitive adhesives.

Abstract: Novel liquid organopolysiloxane resins of the average composition ?R.sup.1 Si(CH.sub.3).sub.2 O.sub.1/2 !.sub.a ?(CH.sub.3).sub.3 SiO.sub.1/2 !.sub.b ?R.sup.2 O.sub.1/2 !.sub.c ?R.sup.1 Si(CH.sub.3)O!.sub.d ?(CH.sub.3).sub.2 SiO!.sub.e ?SiO.sub.2 !,whereinR.sup.1 is a C.sub.2 -C.sub.8 -alkenyl group,R.sup.2 is an optionally substituted, linear or branched C.sub.1 -C.sub.8 -alkyl group or a mixture thereof,a+b+c+d+e is about 1 to 6,d+e is about 0 to 3,the resin has a viscosity of 0.1 to 1000 Pas at 25.degree. C., andthe alkenyl or vinyl content of the resin is in the range of 0.4 to 4 mmol/g,and their preparation by reacting at least one of tetraalkoxysilane and its partial hydrolyzate with at least one organosiloxane and a strong acid as catalyst in the presence of water and optionally an organic solvent at a temperature of about >40.degree. C. They are formulated into novel low viscosity polydiorganosiloxane compositions.

Abstract: The present invention provides novel vinyl containing organopolysiloxane elastomers which possess excellent low compression set and heat aging characteristics and which can advantageously be formulated into liquid silicone elastomer moldable compositions.

Abstract: A method of thickening solvents involves reacting (A) an .tbd.Si--H containing polysiloxane with (B) an alpha, omegadiene; conducting the reaction in the presence of a platinum catalyst and (C) a solvent; continuing the reaction until a gel is formed by crosslinking and addition of .tbd.Si--H across double bonds in the alpha, omega-diene; adding additional solvent and a post cure quenching agent to the gel; and subjecting the solvent, the post cure quenching agent, and the gel to shear force until a paste is formed.

Abstract: This invention relates to a silicone release coating composition comprising an organopolysiloxane having at least 2 alkenyl groups in each molecule, an organopolysiloxane having at least 3 silicon-bonded hydrogen atoms in each molecule, a carbon-carbon triple bond-functional alcohol having a boiling point at ambient pressure of at least 140.degree. C., an organosilicon compound having at least 3 carbon-carbon triple bond-functional hydrocarbon groups bonded across oxygen to silicon, and a platinum catalyst. The silicone release coating compositions of this invention have excellent bath stability, form a very stable thin film on applicator rolls, cure rapidly even at relatively low temperatures, have stable curing characteristics during the course of bath aging, and exhibit stable release values during the course of bath aging.

Abstract: The present invention is a heat curable polyorganosiloxane composition comprising (A) a first polydiorganosiloxane having two diorganoalkenylsiloxy terminal groups per molecule and a total concentration of unsaturated hydrocarbon radicals of 0.118 to 0.156 mole percent; (B) a second polydiorganosiloxane having two diorganoalkenysiloxy terminal groups per molecule, and no detectable concentration of pendant unsaturated hydrocarbon radicals; (C) a third polydiorganosiloxane having two diorganoalkenysiloxy terminal groups per molecule and a total concentration of unsaturated hydrocarbon radicals of 1.37 to 2.24 mole percent; wherein the weight ratio of polydiorganoiloxanes (A), (B), and (C) satisfy the relationship (C)/(A+B)=0.0379 to 0.1071 and A/B=1.460 to 2.115; (D) a crosslinker containing silicone-hydrogen bonds, wherein the ratio of silicone-hydrogen bonds to the total ethylenically unsaturated hydrocarbon radicals present on the polydiorganosilanes (A), (B), and (C) is from 1.00 to 2.

Abstract: Sprayable, environmentally harmless addition curable silicone foul release coating compositions comprise a polyorganosiloxane having at least two organic radicals bound to silicon which have therein a carbon-carbon double bond, a polyorganosiloxane having at least two Si--H moieties per molecule, silica having a surface area in the range of about 100-600 m.sup.2 /g, a platinum group hydrosilylation catalyst and a polymerization inhibitor. One of the polyorganosiloxane components comprises internally functional and terminally functional compounds.

Abstract: Siloxane-based elastomer-forming compositions comprise a first a,w-dihydroxyl polydiorganosiloxane, a second a,w-dihydroxyl polydiorganosiloxane, a third a,w-dihydroxyl polydiorganosiloxane, an organosilicon compound having at least three silicon-bonded substituents selected from the group consisting of hydrogen and alkoxy groups, and a condensation catalyst. The number average molecular weight ratio of the first a,w-dihydroxyl polydiorganosiloxane to the second a,w-dihydroxyl polydiorganosiloxane is in the range of 20 to 80 and the number average molecular weight ratio of second a,w-dihydroxyl polydiorganosiloxane to the third a,w-dihydroxyl polydiorganosiloxane is in the range of 1 to 6. The molar ratio of the first a,w-dihydroxyl polydiorganosiloxane to the second a,w-dihydroxyl polydiorganosiloxane is in the range of 0.01 to 0.15 and the molar ratio of the second a,w-dihydroxyl polydiorganosiloxane to the third a,w-dihydroxyl polydiorganosiloxane is in the range of 0.2 to 2.

Abstract: A silicone gel formulation is described having a Voland hardness of from about 6 to 20 grams, a tack of from about 17 to 35 grams, and a stress relaxation greater than 50%. The material is especially suitable for sealing the back end of connectors containing a multiple fine wires with gauges between about 14 gauge and 28 gauge. It is particularly suitable to seal the back end of an automotive connector subjected to a wide variety of harsh environmental conditions.

Abstract: A liquid silicone rubber base is prepared by mixing an organopolysiloxane containing at least two alkenyl groups, reinforcing silica having a BET specific surface area of at least 50 m.sup.2 /g, and optionally, a mixing assistant. The mixing step includes a first stage of mixing under a first shear stress of at least 1.times.10.sup.6 N/m.sup.2 for 1-5 minutes and a second stage of mixing under a second shear stress which is up to 1/2 of the first shear stress for at least 2 minutes. The silicone rubber base is sufficiently shelf stable to minimize a viscosity rise with time.

Abstract: Hot-melt silicone pressure sensitive adhesive compositions containing organic waxes, methods of using the compositions and devices made using the compositions are disclosed. The hot-melt silicone pressure sensitive adhesive compositions include a mixture of (i) a silicate resin, (ii) a silicone fluid, and (iii) an organic wax having a melting point of between 30.degree. C. and 150.degree. C. The organic wax decreases dynamic viscosity of the adhesive at temperatures equal to or below about 200.degree. C.