Abstract: A solvent-free, cold-setting ternary organosiloxane composition is disclosed, which contains (A) liquid organopolysiloxane, (B) a cross-linking agent, and (C) a curing catalyst, said organopolysiloxane (A) being constituted by organosilicon group of X--Si (wherein X represents a hydrogen atom or a monovalent hydrocarbyl group) and functional side chain of OR (wherein R represents a hydrogen atom, a C.sub.1 -C.sub.5 alkyl group or an acyl group), said cross-linking agent (B) being one or more organometallic compounds selected from the group consisting of an organoaluminum compound, an organoboron compound, an organosilicon compound, an organotitanium compound and an organozirconium compound having at least one functional group selected from among an alkoxy group, an acyloxy group and an oxime group, and said curing catalyst (C) being a metal-containing organic compound, with the total contents of the metal elements of the ternary composition being 40% by weight or more in terms of MO.sub.

Abstract: The invention provides a thermal and addition curable silicone release coating comprising a mixture of an epoxysilicone controlled release additive containing at least one tri- or quadri-functional siloxane unit, a vinyl-functional silicone base polymer, a temperature-dependent hydrosilation inhibitor and an effective hydrosilation catalyst.

Abstract: A silicon-containing polymer comprising repeating units of silicon-containing cyclic compound, represented by a general formula (I) ##STR1## (wherein m and n are zero or a positive integer, respectively, however m+n>0, and X is any of an alkyl group, alkoxy group, phenyl group, naphthyl group, substituted phenyl group and substituted naphthyl group or a mixture of these, and the substituent of said substituted phenyl group or substituted naphthyl group indicates any of halogen atom, halogenated alkyl group, amino group, aminoalkyl group and nitro group or a mixture of these), and a photosensitive material containing said silicon-containing polymer are disclosed.

Abstract: One part organosiloxane compositions exhibiting long term storage stability under ambient conditions and adhesion at curing temperatures below 120.degree. C. comprise a specified combination of platinum catalyst inhibitors and an adhesion promoting composition consisting essentially of a vinyltrialkoxysilane, an epoxy-substituted alkoxysilane, a vinyl-containing hydroxylated polyorganosiloxane, and a chelated aluminum compound.

Abstract: Liquid silicone compositions are described that cure to rubber which exhibits a unique combination of properties including low compression set and unprimed adhesion to a variety of substrates. The compositions include silicone polymers curable by hydrosilation reaction and specific combinations of adhesion promoting materials. Compositions containing aluminum chelates and epoxytrialkoxysilanes have been found particularly useful when adhesion to metal substrates is desired. When the compositions are desired to adhere to plastic materials, it is advantageous to include along with the aluminum chelate and epoxytrialkoxysilane, a tetraalkyltitanate, an alkylpolysilicate, and an acrylate or methacrylate compound.

Abstract: The heat stability of acrylamide functional polydiorganosiloxanes which cure by exposure to ultraviolet radiation can be improved by the addition of nickel carboxylate, stannous naphthenate, cerium carboxylate, manganese carboxylate, aluminum carboxylate, silver carboxylate, copper undecylenate, cobalt carboxylate, mono(methacrylate) tripropoxyzirconate, mono(ethylacetoacetonate) aluminum di-(sec-butoxide), di-(ethylacetoacetonate) aluminum sec-butoxide, zinc acetylacetonate, molybdenum acetylacetonate, and dibutyltin dicarboxylate.

Abstract: A method of making a dispersion of a high viscosity siloxane in a volatile, especially cyclic siloxane, comprises first dispersing organopolysiloxanes having at least 2 Si--OR groups, wherein R is H or alkyl in a volatile siloxane and adding a catalyst which is either a phosphonitrile halide having the general formula [X(PX.sub.2 .dbd.N).sub.n PX.sub.3 ].sup.+ [MX.sub.(v-t+1) R.sub.t ].sup.-, or a heterogeneous catalyst selected from Li, Mg, Ca, Sr or Ba hydroxide, Na or K borate or phosphate, Rb or Cs carbonate or carboxylates of Rb or Cs wherein M is an element having an electronegativity of from 1.0 to 2.0, R is alkyl, X is halide, n is 1 to 6, v is the valence of M and t is from 0 to (v-1).

Abstract: A method of making organopolysiloxanes comprises contacting organosilicon compounds having at least one unit ##EQU1## wherein R.degree. is hydrogen, hydroxyl, a C.sub.1-18 hydrocarbon, substituted hydrocarbon or hydrocarbonoxy group and a has a value of from 0 to 4 with a phosphonitrile halide AB, wherein A is a phosphonitrile halide cation [X(PX.sub.2 .dbd.N).sub.n PX.sub.3 ].sup.+, wherein X is halide and n is from 1 to 8 and B is an anion derived from a Lewis acid not containing a P atom, e.g. [MX.sub.(v-t+1) R.sup.2 .sub.t ].sup.-. The method is particularly useful for condensation of silanol end-blocked siloxanes.

Abstract: The present invention relates to a novel method of preparing siloxane bonds. The method comprises reacting less than or equal to 1 equivalent of a carboxylic acid with 2 equivalents of alkoxy groups on an alkoxysilane in the presence of a strong acid.

Abstract: Curable organopolysiloxanes with epoxy groups are disclosed which contain additionally at least one group of the formula[--O--((C.sub.n H.sub.2n O--).sub.x).sub.y ].sub.z R.sup.3 --O--((C.sub.n H.sub.2n O--).sub.x).sub.y HwhereinR.sup.3 is a divalent alkylene group with 2 to 11 carbon atoms,z is 0 or 1y is 0 or 1z+y is 1 or 2n has an average value of 2 to 3 in the average molecule, the absolute value of n being 2, 3 or 4 andx has a value of 1 to 200.The organopolysiloxanes which contain the additional group are useful as curable coating agents with adhesive properties when used alone or in admixture with curable compounds which have epoxy groups, particularly organopolysiloxanes which contain epoxy groups, but are free of the aforementioned additional group. The organopolysiloxanes are used in combination with catalytically acting curing agents.

Abstract: Polycarbosilanes having Si units which are linked by phenyl-substituted methylene bridges or by partially or completely fluorinated hydrocarbon bridges. These polycarbosilanes are obtained by a Grignard polycondensation reaction. If phenyl substituents are present on the silicon atoms of the polycarbosilanes, they may also optionally be exchanged for halogen atoms in additional halogenating reactions, so that polycarbosilanes can be prepared which are both fluorinated on the hydrocarbon bridges and halogenated (particularly fluorinated) on the silicon atoms.

Abstract: A preparation process of block copolymers which comprises conducting living polymerization of a (meth)acrylic ester substantially in the absence of water, by using a macromolecular compound having a functional end group represented by the formula (1): ##STR1## Wherein R is H or an n-alkyl group having from 1 to 3 carbon atoms and R' is H or an alkyl group having from 1 to 6 carbon atoms, as a polymerization initiator and in the presence of a Lewis acid or in the presence of a donor compound of an anion selected from HF.sub.2.sup.-, (CH.sub.3).sub.3 SiF.sub.2.sup.- or F.sup.-, as well as novel block copolymers prepared therefrom are disclosed.

Abstract: A class of catalysts for the anionic copolymerization of cyclic lactams in the presence of .omega.-(N-acyllactam)polyorganosiloxanes, .alpha.,.omega.-di-(N-acyllactam)polyorganosiloxanes or star-shaped .omega.-(N-acyllactam)polyorganosiloxanes is disclosed. The catalysts successfully protect the siloxane prepolymer from harmful depolymerization reactions at elevated temperatures while anionically polymerizing the cyclic lactams via ringopening. Diblock, triblock, multiblock and star-block copolymers, e.g., of a polyorganosiloxane and a polyamide, with advantageously high polyorganosiloxane and polyamide block molecular weights and superior heat resistance can be synthesized with the catalysts. The composition of these block copolymers, with the structure AB, ABA, and star-(BA).sub.r, r .gtoreq.3, where A=polyamide and B=polyorganosiloxane, and the process for producing them are also described.

Abstract: Compositions which are stable at room temperature, but when heated to an elevated temperature crosslink to form elastomeric solids comprising(A) organopolysiloxanes containing silicon bonded hydroxyl groups,(B) a crosslinking agent selected from(a) silanes,(b) partial hydrolyzates thereof and(c) organohydrogenpolysiloxanes and(C) an aluminum salt of a carboxylic acid which is a solid at room temperature.When the compositions are heated to a temperature of at least 50.degree. C. and more preferably from 100.degree. to 350.degree. C., they cure to form elastomeric solids.

Abstract: An organopolysiloxane graft-type polyester is prepared by reacting, in the presence of an effective amount of a hydrosilylation catalyst, a polyester containing at least one alkenyl group and having no unsaturated terminal groups, said polyester having a number average molecular weight of about 500 to about 5,000, and an organopolysiloxane containing one hydrosilyl group. The organopolysiloxane graft-type polyester has excellent compatibility with polyesters and can improve the surface smoothness and hydrophobic property of the polyester when modified therewith.

Abstract: A hard coating composition comprising an epoxy group-containing organic silicon compound and inorganic submicron particles such as silica sol is curable with a minimal amount of an antimony compound as the curing catalyst. The composition is thus stable during shelf storage and can be cured to a plastic optical article as a mar resistant hard coating film.

Abstract: The invention relates to polyacrylates corresponding to formula (I) ##STR1## to their production in a quasi-ionic polymerization and to their use as monofunctional chain terminators, optionally in combination with typical other chain terminators, for the production of aromatic polycarbonates.The invention also relates to the polycarbonates or polycarbonate mixtures obtained using the compounds corresponding to formula (I) and to their use as additives for other thermoplastic polycarbonates.

Abstract: An antistatic coating composition comprising: (a) a first organosilane compound having at least one epoxy group and at least one hydrolyzable alkoxy group; (b) a second organosilane compound having no epoxy group and two or more hydrolyzable alkoxy groups; (c) 2 to 20 wt %, based on the total weight of said first and second organosilane compounds, of aluminum dihydrogenphosphate; and (d) 50 to 500 parts by weight, based on the total weight of said first and second organosilane compounds, of an organic solvent for said first and second organosilane compounds.The coating composition has a long pot life to be stably stored for a long period of time, and may be coated on any of usual materials including metallic, inorganic and organic materials to form a cured coating film which is excellent in resistance to heat, durability, water-proof property and resistance to chemicals by heating at a relatively low temperature for a short time.Also provided is an improved process for preparing such a coating composition.

Abstract: A coating composition to form a coat on the surface of electrophotographic carrier which imparts excellent durability, moisture resistance and flowability to the carrier comprises:(A) 100 parts by weight of an organopolysiloxane of the general formula;R.sub.a X.sub.b SiO.sub.(4-(a+b))/zwherein R represents a substituted or unsubstituted hydrocarbon residue; X represents a hydroxyl group, or a hydrolizable group; "a" is a number in the range of 0.8<a<1.8; and "b" is a number in the range of 0.1<b.ltoreq.3,(B) 0.05 to 50 parts by weight of an organohydrogenpolysiloxane having at least two hydrogen atoms bonded directly to silicon atom, in a molecule, and(C) a curing catalyst.

Abstract: The silacyclobutane functional polydiorganosiloxane copolymers of the invention have the following structure: ##STR1## wherein M is selected from ##STR2## wherein R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.e, and R.sup.f are independently monovalent radicals selected from the group consisting of hydrogen, hydrocarbon, or substituted hydrocarbon; m and x are integers of from 0 or more; n is equal to 1; and p is an integer greater than 0; with the proviso that there is at least one silacyclobutane group in the copolymer. The copolymer can be made by reacting a hydroxyl endblocked polydiorganosiloxane with either a difunctional chain extending silacyclobutane or with a monofunctional chain stopper, or a mixture of chain extender and chain stopper. The copolymer can be made into curable compositions by use of suitable catalyst.

Abstract: Aqueous dispersions of a silicone, crosslinkable into elastomeric state upon removal of water therefrom under ambient conditions, well adapted for formulation into paints and for the production of silicone elastomer seals, include (A) 100 parts by weight of an oil-in-water emulsion containing a stabilizing amount of at least one anionic and/or nonionic surfactant and at least one alkoxylated diorganopolysiloxane, (B) an effective amount of an inorganic siliceous or nonsiliceous filler material, and (C) a catalytically effective amount of a metal curing catalyst.

Abstract: A resinous composition containing (A) a high molecular weight hydroxy compound having 2 or more hydroxy groups per molecule and having a number average molecular weight of 3,000 to 200,000, (B) a high molecule weight epoxy compound having 2 or more epoxy groups per molecule and having a number average molecular weight of 120 to 200,000, (C) a silane compound having one or more silicon-containing functional groups per molecule and (D) a chelate of aluminum, titanium or zirconium with a ligand exhibiting ketoenol tautomerism, can be cured at temperatures not exceeding 100.degree. C. and forms a desirable coating when cured.

Abstract: A method of preparing an alkoxysilane and a silicone resin includes the steps of combining a siloxane A having a first boiling point with a catalyst in a reaction vessel. A tri or tetra alkoxy functional silane monomer B is added to the vessel having a second boiling point. The contents of the vessel are heated. By a rearrangement reaction, an alkoxysilane is distilled from the vessel. The alkoxysilane has a boiling point which is lower than the mixture of the boiling points of the siloxane A, the silane monomer B and the temperature of the heated vessel. A silicone resin having alkoxy functionality and no silanol functionality is recovered from the vessel.

Abstract: A novel room temperature-curable organopolysiloxane-based composition is proposed which is capable of giving a surface coating highly insusceptible to surface stain even by exposure over years. The composition comprises: (A) a block copolymer composed of dimethylsiloxane units and trifunctional siloxane units of which the organic group is a phenyl group or a fluorine containing aliphatic group, in a specified molar proportion; (B) an organosilane compound having hydrolyzable groups; and (C) a polyoxyalkylene-modified organosiloxane compound of the formula (Me.sub.3 SiO--).sub.2 SiR.sup.4 --C.sub.3 H.sub.6 --(--O--R.sup.5 --).sub.b --O--SiR.sup.6.sub.a X.sub.3-a, in which Me is a methyl group, R.sup.4 is a methyl group or trimethylsiloxy group, R.sup.5 is an ethylene group or propylene group, R.sup.6 is a monovalent hydrocarbon group, X is a hydrolyzable group, the subscript a is zero or 1 and the subscript b is a positive integer not exceeding 50, with optional addition of a condensation catalyst.

Abstract: A room temperature vulcanizable organopolysiloxane composition is provided, comprising (a) a diorganopolysiloxane blocked with a silanol, dialkoxy or trialkoxy radical at both ends of the molecular chain thereof, (b) a novel organic silicon compound of the general formula: ##STR1## wherein R.sup.1 is hydrogen or a monovalent hydrocarbon radical having 1 to 8 carbon atoms, ##STR2## m and l are independently equal to 0, 1 or 2, and n is an integer in the range of 2 to 8, and (c) a curing catalyst. The composition may further contain (d) an organoalkoxysilane.

Abstract: Disclosed is a resin composition curable at a low temperature and characterized in that the composition comprises:(a) at least one of a copolymer comprising as its monomer components an oxirane-containing vinyl monomer and an alkoxysilane-containing vinyl monomer and a vinyl copolymer comprising at its monomer components a polysiloxane macromonomer and an oxirane-containing vinyl monomer,(b) a chelate compound, and(c) a compound having a number average molecular weight of up to about 1,000 and containing at least two alicyclic oxirane groups in the molecule.

Abstract: The present invention relates to the addition of aluminum salts of fatty acids with 12 to 18 carbon atoms, particularly aluminum stearate, to dental impression materials on the basis of addition and/or condensation crosslinking organosilicones to improve their structural viscosity behavior and thus to ease their handling for the dentist.

Abstract: Organic silicon-nitrogen compositions are prepared by the reaction of approximately equimolar amounts of a glycidoxyalkyltrialkoxysilane and a primary amine such as isobutylamine. They are useful as adhesion promoters in room temperature vulcanizable compositions comprising polyalkoxysilyl-terminated polydiorganosiloxanes.

Abstract: The invention relates to a process for treating organocyclosiloxane-containing mixtures with condensation catalysts. The resultant mixtures can be reacted with silanes or siloxanes to form organopolysiloxanes containing functional groups.

Abstract: Polysiloxane compositions which harden in the presence of moisture by elimination of alcohols, which have high stability in storage while unvulcanized in the absence of moisture, which exhibit good adhesion to substrates, and which are improved by the presence of stabilizing silyl derivations of N-methyl benzamide contain:(A) 100 parts by weight of a polydimethyl siloxane which contains terminal diorganyloxyorganosilyl or triorganyloxylsilyl groups and which has a viscosity of 0.1 to 100 Pas,(B) 0 to 100 parts by weight of an .alpha.,.omega.-bis(trimethylsiloxy)-polydimethyl siloxane which has a viscosity of from 0.04 to 10 Pas,(C) 0 to 5 parts by weight of an alkoxysilane having the formulaR.sup.1.sub.a Si(OR.sup.2).sub.4-a,in whichR.sup.1 is C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl or C.sub.5 -C.sub.6 aryl;R.sup.2 is C.sub.1 -C.sub.6 alkyl, and a is 0 or 1,(D) 0.

Abstract: N-Silylalkylamides are useful as adhesion promoters in room temperature vulcanizable compositions comprising polyalkyoxysilyl-terminated polydiorganosiloxanes. The formamides, which are preferred, are novel compounds.

Abstract: Organopolysiloxanes containing triorganosiloxy terminal units are obtained by a continuous process in which an organopolysiloxane mixture containing organo(poly)siloxanes having triorganosiloxy terminal units and cyclic organopolysiloxanes are introduced into a tube reactor that has been heated to at least 80.degree. C. and which contains a static catalyst bed. The organopolysiloxane composition containing triorganosiloxy terminal units, which exits from the tube reactor is different from the organo(poly)siloxanes containing triorganosiloxy terminal units which were introduced into the reactor. The contents of the reactor in the area between one-third and two-thirds of the distance between the point where the organopolysiloxanes are introduced into the tube reactor and the point where the organopolysiloxanes exit from the reactor, are maintained at a temperature which is at least 50.degree. C. below that which is immediately upstream from the outlet of the reactor.

Abstract: A curable composition comprising (A) a siloxane-polyester copolymer, (B) one or more solvents for the siloxane-polyester copolymer, (C) a silane having silicon-bonded alkoxy or alkoxy-alkoxy groups and a silicon-bonded substituent containing an epoxy group, (D) aluminium acetylacetonate and (E) a tetraalkyl titanate.The compositions are heat-curable and are useful for the formation of protective and decorative coatings on substrates such as metals and plastics.

Abstract: Organopolysiloxane resin blended with alkyl-alkoxypolysiloxane resin plus a condensation catalyst is found to have reduced soil retention. Optionally, there may be added perfluoroalkyl resin for improved oil and water repellency.

Abstract: Solventless silicone coating compositions are disclosed which contain a fluid silicone resin and a polydiorganosiloxane fluid.

Abstract: An acid scavenger additive for a one-component, acyloxy-functional RTV composition. The acid scavenger is selected from magnesium materials, zinc materials, and aluminum materials. The acid scavenger prevents a discoloration of the metallic substrate and a decrease in bonding properties of the RTV composition to the substrate on which it is applied.

Abstract: A continuous method for altering the molecular weight of organosilicon compositions containing Si-bonded oxygen in the presence of a catalyst and preferably under decreased pressure, in which a cylindrical reactor is employed have a ratio of length to inside diameter of between 1:1 and 50:1. A reactive mixture is stirred in the cylindrical reactor by a stirring apparatus having one or more stirring blades, so that the mixture is subjected to a maximum centrifugal acceleration b.sub.max of at least 70 m.s.sup.-2 and more preferably at least 165 m.s.sup.-2.

Abstract: Polyorganosiloxane compositions yielding cured elastomers exhibiting cohesive bonding to inorganic substrates contain as the adhesion promoter the combination of (1) a 1,2- bis(trialkoxysilyl)ethane of the general formula (RO).sub.3 SiCH.sub.2 CH.sub.2 Si(OR).sub.3 where R represents an alkyl or haloalkyl radical containing from 1 to 8 carbon atoms, (2) an organosilicon compound containing at least one hydroxyl group or a hydrolyzable precursor thereof and at least one group that reacts at ambient temperature with the alkoxy groups of the silylethane or with the curable polyorganosiloxane composition, and (3) a catalyst for the reaction of the adhesion promoter ingredients.Preferred compositions are cured at room temperature by a platinum catalyzed hydrosilation reaction and are applied to metallic substrates that have not been cleaned or otherwise treated prior to application of the composition.

Abstract: A process for preparing a pressure sensitive adhesive comprising:(A) an organic polymer having in its molecule at least one reactive silicon-containing group represented by the formula (I): ##STR1## wherein R.sup.2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms or a triorganosiloxy group having the formula (II):(R').sub.3 SiO-- (II)in which R' is a monovalent hydrocarbon group having 1 to 20 carbon atoms and may be the same or different, X is hydroxyl group or a hydrolyzable group, and may be the same or different when 2 or more X groups are attached, a is 0 or an integer of 1 to 3, b is 0, 1 or 2, and m is 0 or an integer of 1 to 18, and(B) 0.1 to 20 parts by weight of, per 100 parts by weight of the organic polymer, at least one curing catalyst selected from the group consisting of an organic aluminium and an organic zirconium. The composition has excellent heat resistance and releasability from substrates, e.g. a release paper coated with a silicone release agent.

Abstract: Room temperature-curable organopolysiloxane compositions are made from essentially linear organopolysiloxanes having hydroxyl or hydrolyzable end groups, a crosslinking agent, a filler, optionally a curing catalyst, an unsaturated ester having at least ten carbon atoms in the unsaturated fatty acid component of the ester, and a photosensitizer. These compositions cure to elastomeric materials which do not soil on the surface or the surrounding areas of the substrate in contact with the cure product. The adhesion of these cured products is not reduced.

Abstract: An acid scavenger additive for a one-component, acyloxy-functional RTV composition. The acid scavenger is selected from magnesium materials, zinc materials, and aluminum materials. The acid scavenger prevents a discoloration of the metallic substrate and a decrease in bonding properties of the RTV composition to the substrate on which it is applied.

Abstract: There is provided a room temperature vulcanizable silicone rubber composition which upon curing to the solid, elastic state exhibits improved adhesion to various substrates, comprising:(a) a polydiorganosiloxane wherein the silicon atom at each polymer chain end has bonded thereto at least two hydrolyzable groups,(b) an effective amount of non-chelate condensation catalyst, and(c) an effective amount of metal chelate adhesion promoter.

Abstract: A pressure sensitive adhesive composition comprising:(A) an organic polymer having in its molecule at least one reactive silicon-containing group represented by the formula (I): ##STR1## wherein R.sup.2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms or a triorganosiloxy group having the formula (II):(R').sub.3 SiO-- (II)in which R' is a monovalent hydrocarbon group having 1 to 20 carbon atoms and may be the same or different, X is hydroxyl group or a hydrolyzable group, and may be the same or different when 2 or more X groups are attached, a is O or an integer of 1 to 3, b is 0, 1 or 2, and m is O or an integer of 1 to 18, and(B) 0.1 to 20 parts by weight of, per 100 parts by weight of the organic polymer, at least one curing catalyst selected from the group consisting of an organic aluminum and an organic zirconium. The composition has excellent heat resistance and releasability from substrates, e.g. a release paper coated with a silicone release agent.

Abstract: Phenylene group-containing organopolysiloxanes formed of a plurality of identical or different units represented by the structural formula: ##STR1## where in each case all three possible isomers in relation to the position of the SiO.sub.3/2 --R.sup.1 substituents on the phenylene group can be present concurrently, in which R.sup.1 stands for --CH.sub.2 --CH.sub.2 -- or CH.sub.3 --CH< and the free valences of the oxygen atoms are saturated by silicon atoms of other groups of formula (1) and/or by cross-linking bridge groups. A process for the preparation of these polysiloxanes and the use thereof for the synthesis of carriers of active substances is also disclosed.

Abstract: Functionalized phenylene group-containing organopolysiloxanes, comprising a plurality of identical or different units of the formula: ##STR1## where in each case all three possible isomers in relation to the position of the SiO.sub.3/2 --R.sup.1 substituents on the phenylene group can be present concurrently, in which the bridge groups R.sup.1 represent the groups --CH.sub.2 --CH.sub.2 -- or CH.sub.3 --CH<, X represents Cl, Br, CH.sub.2 Cl, P(C.sub.6 H.sub.5).sub.2, and Ch.sub.2 P(C.sub.6 H.sub.5).sub.2, and the free valences of the oxygen atoms are saturated by silicon atoms of other groups of formula (1) and/or by cross-linking agents. Also disclosed is a process for the preparation of said polysiloxanes.

Abstract: There is disclosed a resin composition comprising(A) a spiro ortho ester compound and/or a spiro ortho carbonate compound;(B) an aluminum compound; and(C) a silanol compound or a silicon compound which is capable of generating a silanol group;the amounts of components (B) and (C) being within the range of 0.001 to 10% by weight and 0.1 to 20% by weiht, based on the amount of component (A), respectively.The resin composition of this invention is excellent in volumetric shrinkage performance at curing operation and is good in storability. Therefore, the cured product can be used for a wide variety of industrially valuable applications, such as an ink, a coating, an adhesive, a surface coating, an encapsulation and an electrical insulating material.

Abstract: In a process for varying the molecular weight of linear or cyclic organopolysiloxanes in the presence of a catalyst which is solid in the reaction mixture at the reaction temperature, the improvement comprising that the catalyst which is solid in the reaction mixture at least at the respective reaction temperature and the organopolysiloxane whose molecular weight is to be changed are continuously and simultaneously passed through a heated cylindrical reactor whose contents is mechanically moved, the reactor having a length to inside diameter ratio of 1:1 to 20:1 and its interior pressure being held at 50 to 500 hPa (abs.) and the catalyst is removed from the mixture after leaving the reactor.

Abstract: Organopolysiloxane compositions that are crosslinked by ultraviolet light comprising (A) an organopolysiloxane having units of the formulaHR.sup.1 C=CR.sup.2 COOR.sup.3 SiR.sub.2 O.sub.1/2,in which at least two such siloxane units are present per molecule of organopolysiloxane (A) and at least 80 percent of the number of the remaining siloxane units in organopolysiloxane (A) comprise units of the formulaR.sub.2 SiO,where R is a monovalent hydrocarbon radical or a halogenated monovalent hydrocarbon radical, R.sup.1 is hydrogen or a halogenated phenyl radical, R.sup.2 is hydrogen or an alkyl radical having from 1 to 4 carbon atoms per radical and R.sup.3 is a divalent hydrocarbon radical or a halogenated divalent hydrocarbon radical, in which the organopolysiloxane (A) has an average viscosity of from 20 to 5000 mPa.s at 25.degree. C., (B) an organopolysiloxane terminated by units of the formula R.sub.3 SiO.sub.178 , and having from 0.05 to 5 mole percent of units of the formula ##EQU1## wherein R and R.sup.

Abstract: An organosilicon polymer whose main-chain skeleton is composed mainly of following structural units (A), (B), (C), (D), (E) and (F) ##STR1## wherein R represents CH.sub.3 or H, said structural units forming linear, branched and cyclic structures, and said main-chain skeleton further having a polysilane skeleton ##STR2## (2.ltoreq.n.ltoreq.10). The said organosilicon polymer can be produced by adding at least one anhydrous metal halide to a polysilane having the structure ##STR3## the amount of the metal halide being 0.5 to 10% by weight based on the weight of the polysilane; and heating the mixture in an atmosphere inert to the reaction.

Abstract: Siloxane modified isocyanurate polymers are disclosed which are the reaction product of a siloxane containing polyahl and a polyisocyanate in the presence of a catalyst for a trimerization of the isocyanate to form isocyanurate rings.