Abstract: Cold processable heat curable alkenyl silicone rubbers that comprising an alkenyl silicone gum or mixture of alkenyl silicone gums selected from the group of alkenyl silicone gums having the formula:(M.sub.a M.sup.vi.sub.1-a)(D.sup.vi).sub.x (D).sub.y (M.sub.a M.sup.vi.sub.1-a);a process for making such heat curable rubbers, and articles of manufacture made therefrom.

Abstract: A silicone rubber composition which has excellent adhesion to various substrate materials with which it is in contact during its curing. The silicone rubber composition comprises an adhesion promoter comprising an addition reaction product or a reaction mixture of (i) a carboxylic acid ester described by general formula ##STR1## where R.sup.2 is an alkenyl group and x is a number of 1 to 6, and (ii) an alkoxysilane expressed by general formula ##STR2## where R.sup.3 is a monovalent hydrocarbon group which does not contain aliphatic unsaturated linkage, R.sup.4 is an alkyl group, and a is a number of 1 to 3.

Abstract: An anaerobically curing composition is comprised of (i) a silicone fluid formed as the reaction product of at least one first silane of formula I:R.sub.n Si(X).sub.4-n (I),wherein the R groups are the same or different and selected from the group consisting of hydrogen, C1-C12 alkyl, C6-C12 aryl, C7-C18 arylalkyl, C7-C18 alkylaryl, haloalkyl, haloaryl and monovalent ethylenically unsaturated radicals excluding (meth)acryloxy functional groups, X is a hydrolyzable functionality, and n is an integer of from 0 to 3, and at least one second silane of formula II:R.sup.1.sub.m R.sup.2.sub.p Si(X).sub.4-(m+p) (II),wherein R.sup.1 is a (meth)acrylic functional group and R.sup.

Abstract: Pressure sensitive silicone adhesive compositions having excellent peel adhesive strength, high tack and excellent quick stick capability are provided. Generally the adhesive composition is made of a MQ resin and a silicone gum, to which a silicone fluid is added. A cure catalyst can then be added to the mixture prior to coating.

Abstract: A process for the preparation of alkylsilanes and alkenyl silanes by hydrosilylation of their corresponding silanes and unsaturated hydrocarbons in the presence or absence of a catalyst. A process for the preparation of polyalkenylsilanes (some of which are novel high molecular compounds) by the anionic coordination polymerization, radical polymerization or ionic polymerization of the alkenylsilanes. A process for the production of silicon carbide by using these polyalkenylsilanes as prepolymers.

Abstract: This invention provides curable compositions comprising a polytitanosiloxane containing at least two alkenyl radicals per molecule and a crosslinking agent that is either 1) the combination of an organohydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule and a platinum-containing catalyst or 2) an organic peroxide. This invention also provides a method for curing a polytitanosiloxane by reacting it with the crosslinking agent of the present compositions.

Abstract: The present invention relates to branched silicon-bonded hydrogen endblocked organosilicon compounds containing silalkylene groups and to a method for the preparation of such compounds. The organosilicon compounds of this invention are soluble in certain organic solvents and can be prepared such that they have a very high weight average molecular weight.

Abstract: Silicone adhesive compositions having excellent quick stick, peel and tack adhesion properties are provided. Generally the adhesive composition is the reaction mixture of a silanol-containing siloxane resin, a silicone polymer gum, and a silicone fluid containing functionality capable of reacting with silanol and silanol-like groups; optionally, a solvent; and a cure catalyst are added.

Abstract: Crosslinkable copolymers suitable for use as elevated temperature pressure-sensitive adhesives comprise randomly arranged silarylene units and siloxane units. Preferably, there is present in the copolymer backbone in the range of 0.8 to 1.2 siloxane to silarylene units, and there being present in the copolymer a crosslinking functionality.

Abstract: A fuser roll having a metal core shaft has a resilient layer placed around the metal core shaft with at least the surface layer of the resilient layer comprising a fluorosilicone rubber layer containing 5 to 50 wt. % polytetrafluoroethylene. Since this fuser roll is excellent in releasability and silicone oil resistance, the durability is excellent, and the image obtained by a copying machine wherein the roll is used becomes sharp.

Abstract: Single component inorganic/organic network materials incorporating the physical properties of glasses with the flexibility of organic materials of empirical formula X(SiO.sub.1.5).sub.n wherein X is one or more flexible organic linkages and n is greater than or equal to 2, as well as precursors thereof, are disclosed.

Abstract: The introduction of release coating-forming silicone compositions that yield cured release coatings that exhibit excellent release properties against tacky substances and do not impair the residual adhesion of tacky substances.Silicone composition for the formation of cured release coatings, that characteristically comprises(A) 100 weight parts of a cured coating-forming silicone composition into which there is admixed(B) 0.5 to 500 weight parts organosilicon polymer with the following average unit formula ##STR1## wherein R represents C.sub.1 to C.sub.10 monovalent hydrocarbon groups that are free of aliphatic unsaturation; R.sup.1 represents organic groups selected from the group consisting essentially of C.sub.2 to C.sub.20 alkylene groups and organic groups with the formulas --R.sup.3 (OR.sup.3).sub.y -- and --R.sup.3 --(R.sub.2 SiO).sub.z R.sub.2 Si--R.sup.3 -- (R is defined as above, R.sup.3 denotes C.sub.2 to C.sub.

Abstract: Adhesion-promoting additives for use in curable organosiloxane compositions comprise 1) at least one organosiloxane comprising a) silicon bonded hydrogen atoms and/or ethylenically unsaturated substituents bonded to silicon through carbon and b) at least one silicon atom containing three hydrolyzable groups, and 2) at least one silane containing four alkoxy or enoloxy groups or three of these groups and a hydrocarbon radical containing an epoxy or ethylenically unsaturated group as a substituent.

Abstract: An organic silicon alternating copolymer which resistant to chain scission by acid or alkali is disclosed, said copolymer comprising repeat units having the formula ##STR1## wherein R represents a monovalent hydrocarbon group having 1 to 10 carbon atoms and containing no aliphatic unsaturation, R.sup.1 represents a fluorine atom-containing monovalent organic group having 4 to 10 carbon atoms and containing at least two groups of the formula -CF.sub.2 -, R.sup.2 represents an alkylene group having 2 to 10 carbon atoms and said copolymer has a degree of polymerization of 1 to 10,000.

Abstract: Monodisperse, homogeneous polyaminoborazines, well suited for pyrolysis into ceramic BN shaped articles, e.g., fibers, films, etc., are prepared by thermally polycondensing a trifunctional aminoborazine under conditions of polycondensation reaction equilibrium.

Abstract: The introduction of a room-temperature-curable organopolysiloxane composition that exhibits tack during the course of its cure and that forms a cured product strongly adherent to a variety of substrates when cured while in contact with substrate. Also, the introduction of a method for the preparation of this room-temperature-curable organopolysiloxane composition.

Abstract: An uncrosslinked polysilazane containing chemically bound peroxide groups is prepared by reacting a polysilazane and a hydroperoxide at a temperature below the decomposition temperature of the hydroperoxide. A thermoset polymer is formed by heating an uncrosslinked, peroxide-substituted silazane that is also substituted by alkenyl or alkynyl groups at temperatures sufficiently high to decompose the chemically bound peroxide groups to yield a free radical, thereby initiating crosslinking. The crosslinked polysilazanes can be pyrolyzed to form ceramic articles.

Abstract: Disclosed is a rubber member for paper-feeding machine parts, such as rubber rollers, rubber belts and the like in copying machines and printers of computers, word processors, facsimile machines and the like, capable of exhibiting excellent smoothness and stability of paper transfer performance. The rubber member is a cured silicone rubber body obtained by curing a specific silicone rubber composition containing a silicone-based tackifier and a cured silicone rubber powder and is characterized by the specific values of the tear strength, ultimate elongation and rubber hardness.

Abstract: A compound having a group --N.dbd.N-- is added to a conductive silicone rubber composition comprising an organopolysiloxane, conductive carbon black, and an organic peroxide. The composition allows for atmospheric hot air vulcanization with the aid of an organic peroxide irrespective of the inclusion of carbon black and is significantly improved in shelf stability. The conductive silicone rubber resulting therefrom is free of voids or surface tack and has improved heat resistance and conductivity.

Abstract: A fluorosilicone pressure sensitive adhesive (PSA) having high solvent resistance is disclosed, The PSA is formed of (A) from about 5 to 70 percent fluorosilicone polymers; (B) from about 10 to 60 percent of a silanol containing MQ resin; and (C) from about 10 to 50 percent of resin compatible diorganosiloxane polymers and may be diluted and cured in the presence of a catalyst or initiator.

Abstract: A paper feed roller formed from a high friction rubber obtained by curing a high friction rubber-forming composition comprising in admixture,(A) a silicone rubber compound containing an organopolysiloxane of the average compositional formula (1):R.sub.n.sup.1 SiO.sub.(4-n)/2 (1)wherein R.sup.1 is a substituted or unsubstituted monovalent hydrocarbon group, the groups represented by R.sup.1 containing up to 95 mol. % of a methyl group, at least 3 mol. % of a phenyl group and at least 0.2 mol. % of a vinyl group, and n is a positive number of from 1.95 to 2.05, and(B) a silicone rubber compound containing an organopolysiloxane of the average compositional formula (2):R.sub.m.sup.2 SiO.sub.(4-m)/2 (2)wherein R.sup.2 is a substituted or unsubstituted monovalent hydrocarbon group, the groups represented by R.sup.2 containing at least 98 mol. % of a methyl group, and m is a positive number of from 1.95 to 2.05,said silicone rubber compounds (A) and (B) being mixed in a weight ratio between 5:95 and 95:5.

Abstract: By curing either one of an organic peroxide-curable silicone rubber composition and an organic peroxide-curable unsaturated polyester resin composition and then curing the other composition while placing it in close contact with the cured composition, there is obtained a composite material in which an organic peroxide-cured silicone rubber is closely and firmly joined with an organic peroxide-cured unsaturated polyester resin.

Abstract: The composition of the present invention comprises an oil-resistant silicone rubber composition that undergoes little swelling even when used in regular or continuous contact with mineral oil-based lubricating oil such as engine oil and so forth. The oil-resistant silicone rubber composition comprises:(A) a dimethylsiloxane-3,3,3-trifluoropropylmethylsiloxane-methylvinylsiloxane copolymer gum that contains 0.001 to 5 mole percent methylvinylsiloxane unit,(B) a hydrocarbon oil or diorganopolysiloxane oil wherein the total in each diorganopolysiloxane oil molecule of the number of silicon-bonded hydrogen atoms and the number of functional groups reactive with component (A) or (C) is less than two,(C) a reinforcing filler, and(D) a curing agent in a quantity sufficient to cure the composition.

Abstract: Self-adhesive silicone compositions having (A) an organopolysiloxane of the following average unit equation (1)(R.sup.1).sub.z --SiO.sub.(4-z)/2 (1)wherein R.sup.1 is either a substituted or an unsubstituted monovalent hydrocarbon group and Z is a number in the range from 1.98 to 2.01 having a viscosity at 25.degree. C. of at least 300 cSt,(B) an organic silicon compound which possesses at least one group expressed by the following equation (2) within the molecule: ##STR1## wherein R.sup.2 is a substituted or an unsubstituted monovalent hydrocarbon group, R.sup.3 and R.sup.4 are either a hydrogen atom, methyl group, or an ethyl group, and n is an integer of 0, 1, or 2, and(C) an organic peroxide. The silicone compositions strongly adhere onto various materials such as metals and plastics without the need of primer treatments.

Abstract: A fuser member comprised of a supporting substrate comprising an outer layer of a volume grafted elastomer, which is a substantially uniform integral interpenetrating network of a hybrid composition of a fluoroelastomer and a polyorganosiloxane, said volume graft having been formed by dehydrofluorination of said fluoroelastomer by a nucleophilic dehydrofluorinating agent, followed by addition polymerization by the addition of an alkene or alkyne functionally terminated polyorganosiloxane and a polymerization initiator; and wherein said outer layer contains a reactive metal oxide in an amount of from about 2 to about 7 weight percent.

Abstract: A new highly crosslinked silicone polymer particle for gas chromatography application and a process for synthesizing such copolymer. The new copolymer comprises vinyltriethoxysilane and octadecyltrichlorosilane. The copolymer has a high degree of crosslinking and a cool balance of polar to nonpolar sites in the porous silicon polymer assuring fast separation of compounds of variable polarity.

Abstract: An uncrosslinked polysilazane containing chemically bound peroxide groups is prepared by reacting a polysilazane and a hydroperoxide at a temperature below the decomposition temperature of the hydroperoxide. A thermoset polymer is formed by heating an uncrosslinked, peroxide-substituted silazane that is also substituted by alkenyl or alkynyl groups at temperatures sufficiently high to decompose the chemically bound peroxide groups to yield a free radical, thereby initiating crosslinking. The crosslinked polysilazanes can be pyrolyzed to form ceramic articles.

Abstract: Silicone rubber compositions which comprise (A) an organopolysiloxane, which possesses at least one triorganosilyl-amine group expressed by the following equation (1) at its molecular end and a degree of polymerization which is at least 2000, and the silicone rubber compositions which further comprise (B) a fine powdered silica whose specific surface area is at least 50 m.sup.2 /g, ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each a substituted or unsubstituted monovalent hydrocarbon group, each of which can be the same or different. The silicone rubber compositions are a non-fluidity type; therefore, they offer superior workability and formability. Further, silicone rubber obtained by the curing of the said compositions possess superior physical properties, extremely low hardness, flexibility, and good rubber elasticity, thus they are useful as raw materials of various products.

Abstract: Disclosed are organosilicon crosslinked polymers and crosslinkable prepolymers that are the reaction product of (a) a cyclic polysiloxane in which each silicon atom is substituted with (i) a saturated, substituted or unsubstituted alkyl or alkoxy group or a substituted or unsubstituded aryl or aryloxy group, and (ii) a substituted or unsubstituted hydrocarbon group having at least one carbon-carbon double bond that is reactive in hydrosilation, (b) at least one organosilicon compound having at least two .tbd.SiH groups, and optionally (c) a hydrocarbon polyene having at least two nonaromatic carbon-carbon double bonds that are reactive in hydrosilation. A process for preparing the polymers and prepolymers and for preparing the cyclic polysiloxanes is also disclosed.

Abstract: A cover-gasket assembly for a hard disk device which comprises a gasket applied to a predetermined position of a cover for the hard disk device, wherein the gasket is formed essentially of a cured product of a fluorosilicone rubber composition. The assembly is particularly excellent in sealing property against permeation of water vapor, and can be used extremely effectively for hard disk devices for handy office-automation apparatuses such as laptop or pocket-size personal computers, word processors and the like which are expected to be used under various temperature and humidity conditions.

Abstract: A composition comprising (A) an organopolysiloxane having a unit of the formula: R.sup.1 SiO.sub.3/2 wherein R.sup.1 is methyl, phenyl or vinyl in its molecule and having at least 0.05 alkenyl groups each directly attached to a silicon atom per silicon atom, (B) an organohydrogenpolysiloxane having at least 2 hydrogen atoms each directly attached to a silicon atom per molecule, (C) a platinum catalyst, and (D) an organosilane or organopolysiloxane of the formula: R.sup.2.sub.a (R.sup.3 O).sub.b SiO.sub.(4-a-b)/2 wherein R.sup.2 and R.sup.3 are hydrogen, methyl, phenyl or vinyl maintains good light transmission in cured form when exposed to humidity and is thus suitable for forming cores of optical fibers. Similar benefits are obtained with a composition comprising components (A) and (B), (C') a platinum catalyst and/or a radical polymerization initiator, and (E) a carboxylate.

Abstract: A novel self-adhesive silicone rubber composition is disclosed which gives a cured silicone rubber capable of being firmly bonded to the surface of various kinds of substrate materials even without the pre-treatment of the substrate surface with a primer so that the composition is useful as a coating material in the preparation of a silicone rubber-coated cloth advantageous in respect of the firm adhesion of the cured silicone rubber layer to the substrate cloth. The composition is characterized by the formulation of a unique component which is an organosilane compound having an isocyanato-containing group and a hydrolyzable group in a molecule such as 3-isocyanatopropyl trimethoxy silane.

Abstract: A sealant for use at temperatures greater than about 700.degree. F. may be formed from:(a) about 40 to 90 wt-% of a silicone having a molecular weight of about 10,000 to 10,000,000 and repeating units comprising:(i) about 1 to 20 mole-% of units having the formula: ##STR1## wherein R comprises --H, a C.sub.1-5 alkyl group, a C.sub.1-5 fluoroalkyl group, a vinyl group or a phenyl group and(ii) about 99 to 80 mole-% of units having the formula: ##STR2## wherein each R independently comprises --H, a C.sub.1-5 alkyl group, a C.sub.1-5 fluoroalkyl group, a vinyl group, or a phenyl group; and(b) about 1 to 10 wt-% of a thermal stabilizer;(c) about 0.1 to 2 wt-% of a curing agent; and(d) about 0 to 50 wt-% of an inorganic filler;wherein the composition remains an effective sealant at temperatures above about 700.degree. F. The sealant may be used to bond and seal a barrier film or vacuum bag to a forming tool in autoclave curing and processing of thermosetting and thermoplastic composites.

Abstract: A fluorine-containing silicone rubber composition comprising (A) a fluorocarbonsiloxane having the following general formula (1): ##STR1## wherein a to d is a positive integer, R.sup.1 and R.sup.2 are a monovalent hydrocarbon group free of aliphatic unsaturated groups, R.sup.3 is a monovalent hydrocarbon group containing an aliphatic unsaturated bond, Rf.sup.1 is a fluorine-containing alkylene polyether group, and (B) an organic peroxide. The composition is excellent in solvent resistance, chemical resistance and water and oil repellency, and can be molded by press molding and has been improved in respect of insufficient curing.

Abstract: An air bag coating composition predominantly comprising an organopolysiloxane having a degree of polymerization of 1,000 to 10,000 and a molecular weight distribution index (Mw/Mn) of less than 5 is provided. The composition is applied and cured to an air bag base fabric without strike-through.

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: Novel polysiloxane-silazane preceramic polymer compositions are prepared by the controlled hydrolysis polymerization of a trimer or tetramer of a monomer of the structure ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently alkyl groups containing from 1 to 4 carbon atoms R.sup.a, R.sup.b, R.sup.c, and R.sup.d are independently alkenyl or alkyl groups containing from 2 to 6 carbon atoms with the proviso that at least one of R.sup.a, R.sup.b, R.sup.c, or R.sup.d group is an alkenyl group.Another useful composition is made by reacting the above mentioned monomers with alkoxide or aryloxide compounds of the elements Al, B, Zr, Ti, Si, Hf, and Y in the presence of water to make polysilazoxane polymers modified with said alkoxides or aryloxide compounds. Another useful composition is made by reacting the polysiloxane-silazane polymer with vinyl or allyl substituted compounds of boron or silicon or both.

Abstract: Silicone rubber compositions based on an organopolysiloxane are improved in release properties by blending a silane having both a fluorinated hydrocarbon group and an alkanoyloxy group and/or an organopolysiloxane having an alkanoyloxy or alkanoyloxyalkyl group.

Abstract: A silicone rubber composition that will be cured using as catalyst a platinum family metal and an organic peroxide, comprising as its constituent component an organosilizane compound represented by the following general formula:(R.sup.2).sub.3 SiNH(R.sup.3 R.sup.4 SiO).sub.n R.sup.3 R.sup.4 SiNHSi(R.sup.2).sub.3wherein R.sup.2 represents a substituted or unsubstituted monovalent hydrocarbon group, R.sup.3 and R.sup.4, which may be the same or different, each represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, and n is an integer of 2 to 20. Even if a large amount of a silica filler is blended in this silicone rubber composition, the silicone rubber composition is excellent in that it has suitable plasticity and is low in crepe hardening and good in workability such as rollability and extrudability.

Abstract: A silicone rubber composition is prepared by mixing a diorganopolysiloxane which contains 0.1 to 5 weight % of low-molecular-weight organosiloxane with a vapor pressure at 200.degree. C. of at least 10 mm Hg, with at least 90 weight % of a low-molecular-weight organosiloxane with a boiling point not exceeding 250.degree. C. at 760 mm Hg and a curing agent with filler being optional. These silicone rubber compositions are useful for silicone rubber moldings which can be used to in applications involving electrical switch contacts resulting in electrical switch contact conduction free of defects.

Abstract: A modified organopolysiloxane comprising [R.sup.1.sub.2 SiO.sub.2/2 ] or [R.sup.1.sub.3 SiO.sub.1/2 ] units wherein R.sup.1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms, at least two R.sup.1 substituents per molecule being replaced by specific isocyanurate or cyanurate groups is a vulcanization activator for assisting in vulcanization of fluorocarbon rubber or fluorocarbon/silicon rubber compositions with peroxide vulcanizing agents. It is prepared by reacting triallyl isocyanurate, triallyl cyanurate or a derivative thereof with dimethylchlorosilane or methyldichlorosilane in the presence of a platinum catalyst to form a chlorosilane containing diallylisocyanurate or diallylcyanurate groups, followed by hydrolysis. An alternative process is by reacting triallyl isocyanurate, triallyl cyanurate or a derivative thereof with a siloxane in the presence of a platinum catalyst.

Abstract: A method of preparing vinyl-silicone copolymers which involves the use of a mercapto-functional silicone compound as a macromolecular chain transfer agent. Release coatings and low adhesion backsizes comprising the vinyl-silicone copolymers.

Abstract: Organosilicon polymers of polycyclic polyenes, cyclic polysiloxanes and/or tetrahedral siloxysilanes, and unsaturated hydrocarbyl group-bearing silicon compounds. The polymers are prepared by reacting the indicated compounds together, or by reacting the hydrocarbyl group-bearing silicon compounds with prepolymers of the polycyclic polyenes and cyclic polysiloxanes and/or tetrahedral siloxysilanes.

Abstract: The present invention is characterized by producing a one part organopolysiloxane composition by mixing an organohydrogenpolysiloxane, an addition reaction catalyst, and a hydroperoxide (retarding agent), maturing the resulting mixture at a temperature of 0.degree. to 60.degree. C. for 10 hours or more, and then mixing the obtained mixture with an organopolysiloxane that is a base component. According to this method, the viscosity increase of a one part organopolysiloxane composition wherein a hydroperoxide is used as a retarding agent and the curing delay of said composition due to aging can be obviated.

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: A silicone rubber composition comprises, as the base component thereof, a diorganopolysiloxane having the following general formula: ##STR1## wherein Rf is a perfluoroalkyl group or a perfluoroalkyl ether group, X is hydrogen, (CH.sub.3).sub.3 Si--, or (CH.sub.2 .dbd.CH)(CH.sub.3).sub.2 Si--, l and m are each an integer of 1 or above, and n is an integer of 0 or above. The silicone rubber composition has excellent resistance not only to nonpolar solvents such as benzene but also to polar solvents such as ketones, esters, etc.

Abstract: A silicone rubber composition having excellent workability and extrusion-moldability and capable of giving cured silicone rubber articles having good mechanical properties is proposed, which is prepared by admixing, in addition to the conventional ingredients of an organopolysiloxane gum, a finely divided reinforcing silica filler and a curing agent such as an organic peroxide, a low molecular-weight organopolysiloxane having, in a molecule, at least three silanolic hydroxy groups which serves as a wetting agent of the silica filler so as to improve the compatibility of the silica filler with the organopolysiloxane gum giving a possibility of increasing the amount of the silica filler without adverse influences such as a decrease in the plasticity of the composition.

Abstract: A method is disclosed for preparing a heterogeneous silicone rubber molding wherein a portion of the molding is formed from a semicured silicone rubber particulate and a portion from a thermosetting silicone rubber composition. The mold is filled with the particulate and the thermosetting silicone rubber composition, then closed and pressurized and heated, forming the portions into a single body or element by curing the thermosetting silicone rubber composition at the same time that curing of the semicured silicone rubber particulate is brought to completion.

Abstract: A method for the manufacture of silicone rubber moldings comprises the preparation of a silicone rubber composition by blending an organoperoxide having an activation energy of 25 to 41 kcal/mol into a semicurable organopolysiloxane composition whose main component is organopolysiloxane having organoperoxide-crosslinkable functional groups. The silicone rubber composition is made into a particulate form and heated at a temperature below 100 degrees Centigrade to produce a semicured, particulate molding material which retains the activity of the organoperoxide and which contains residual crosslinkable functional group on the organopolysiloxane. Subsequently a mold is filled with the molding material and the mold material is completely cured at a temperature of at least 100 degrees Centigrade under the application of pressure. The method is particularly useful for automatic molding methods.

Abstract: A composition that comprises a (thio)amide-modified silazane polymer containing at least one alkenyl or alkynyl group and a free radical generator can be crosslinked by an energy input provided in the form of heat, ultraviolet radiation, or an electron beam. The crosslinked (thio)amide-modified silazane polymer composition can be pyrolyzed to form a silicon nitride-containing ceramic.