Abstract: The present invention provides nonflammable silicone rubber compositions which exhibit a superior non-inflammability and a reduced toxicity due to by-products generated during vulcanization and forming processes.

Abstract: An improvement is proposed for an acrylic rubber composition to decrease the stickiness of the rubber composition under processing and shaped and vulcanized articles of the composition to a metallic surface with which the rubber article is kept in contact at an elevated temperature under compression as is the case in packings, gaskets and O-rings as automobile parts. The improvement can be obtained by compounding the rubber composition consisting of an acrylic rubbery polymer, which can be substituted by organosilicon groups, and a reinforcing filler with a limited amount of a specific diorganopolysiloxane, e.g., dimethyl polysiloxane, of which from 5 to 50% in number of the organic groups bonded to the silicon atoms are phenyl groups.

Abstract: A method of producing a silicone rubber composition, comprising heating a mixture of an organopolysiloxane having a silanol group at both the ends of the molecular chain, a end blocking agent, such as a triorganosilanol, a silane or a siloxane having two dialkylaminosilyl groups in the molecule, and a reinforcing filler thereby carrying out chain lengthening and end blocking of said organopolysiloxane. According to this method, a silicone rubber composition whose low-molecular siloxane content is held down remarkably can be produced without consuming a large amount of energy for the mixing.

Abstract: To a silicone rubber composition including (A) a diorganopolysiloxane having an aliphatic unsaturated hydrocarbon group, (B) an organohydrogenpolysiloxane having at least two SiH groups in a molecule, and (C) a platinum catalyst, is added (D) an organic silicon compound of the following general formula (2): ##STR1## wherein R.sup.2, R.sup.5, and R.sup.6 are independently selected from monovalent hydrocarbon groups free of an aliphatic unsaturated bond, R.sup.3 is a monovalent hydrocarbon group, R.sup.4 is hydrogen or methyl, and n is an integer of 0 to 3. The composition has a long pot life after addition of curing components (B) and (C) and is extrusion moldable into bubble-free transparent parts. The composition is prepared by mixing component (A) with components (B) and (C) while adding component (D) thereto.

Abstract: A manufacturing method of organosilanes having silanol groups which is characterized by mixing organoalkoxy silanes, having at most a 20 ppm content of chlorine, expressed by the general chemical formula (1) below:Si(R.sup.1).sub.m (R.sup.2).sub.n (OR.sup.3).sub.k (1)wherein each of R.sup.1 and R.sup.2 is either a substituted or unsubstituted monovalent hydrocarbon group; R.sup.3 is an alkyl group of 1 to 4 carbon atoms; subscripts m and n are 0, 1, 2, or 3; k is either 1 or 2; and the sum of subscripts m+n+k=4, with ion-exchanged water having an electroconductivity of at least 10.sup.10 M.OMEGA., then further adding a macro-porous cation-exchange resin with a pore volume measured by the mercury injection method of at least 0.1 ml/g to the said mixture, followed by stirring of the mixture and removal of the cation-exchange resin.

Abstract: An expandable conductive-silicone rubber composition includes (A) an organopolysiloxane having at least two alkenyl groups, (B) conductive carbon black, (C) an organic peroxide of the formula: ##STR1## wherein R.sup.2 and R.sup.3 each are a monovalent C.sub.3 -C.sub.10 hydrocarbon group or a group of --SiR.sup.4.sub.3 wherein R.sup.4 is methyl, ethyl or phenyl, X is --(CH.sub.2).sub.n --, --CH.sub.2 --C(CH.sub.3).sub.2 --CH.sub.2 -- or --(C.sub.2 H.sub.4 O).sub.m --C.sub.2 H.sub.4 -- wherein n=2 to 8 and m=1 to 4, (D) an organohydrogenpolysiloxane, (E) a platinum catalyst, and (F) a blowing agent. It is fully stable during shelf storage, has a long pot life, and is rapidly expandable and curable through hot air vulcanization into conductive silicone rubber foam having high conductivity and improved fatigue endurance of sponge cells when the foam is used as a sponge roll.

Abstract: A conductive silicone rubber composition is prepared by mixing an organopolysiloxane having an aminoalkyl radical, an organopolysiloxane having a (meth)acryloxyalkyl or glycidoxyalkyl radical, and conductive carbon black to form silicone rubber composition (A) in which the carbon black is fixed, and then mixing it with a silicone rubber composition (B) comprising a dimethylpolysiloxane. The composition has stable resistivity in the semiconductive region independent of molding conditions.

Abstract: Organopolysiloxanes having a silanol group at both terminal ends of molecular chain thereof are brought into condensation reaction with each other in the presence of a silane or siloxane having at least two dialkylaminosilyl groups per molecule as a condensation catalyst and a triorganosilanol or other endblocking agent, to lengthen the chain of the organopolysiloxane under reaction, whereby a triorganosilyl-endblocked organopolysiloxane with a high polymerization degree is obtained. The process yields a triorganosilyl-endblocked high-polymerization-degree organopolysiloxane while effectively suppressing or preventing the formation of low-molecular-weight siloxanes.

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 conductive silicone rubber composition comprising (A) an organopolysiloxane, (B) conductive carbon black, and (C) an organic peroxide is improved in shelf stability by adding (D) a fatty acid or an acid anhydride thereto. The composition is subject to atmospheric hot air vulcanization to form a conductive silicone rubber having improved conductivity and physical properties.

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: An improvement is proposed for an acrylic rubber composition to decrease the stickiness of the rubber composition under processing and shaped and vulcanized articles of the composition to a metallic surface with which the rubber article is kept in contact at an elevated temperature under compression as is the case in packings, gaskets and O-rings as automobile parts. The improvement can be obtained by compounding the rubber composition consisting of an acrylic rubbery polymer, which can be substituted by organosilicon groups, and a reinforcing filler with a limited amount of a specific diorganopolysiloxane, e.g., dimethyl polysiloxane, of which from 5 to 50% in number of the organic groups bonded to the silicon atoms are phenyl groups.

Abstract: A silicone rubber composition comprising (A) an organopolysiloxane, (B) an organic peroxide and (C) carbon black cures under anaerobic conditions into silicone rubber having improved physical properties. A composition further comprising (D) an organopolysiloxane copolymer consisting essentially of M and Q units in a molar M/Q ratio of 6/10 to 9/10 forms an anaerobic adhesive composition which is a useful sealant.

Abstract: A novel method is proposed for the effective utilization of scraps of cured silicone rubbers, of which no method of disposal is known heretofore other than discarding as a waste material. Namely, scraps of cured silicone rubbers can be compounded in a considerably large amount with a vulcanizable composition based on an organic rubbery elastomer such as fluorocarbon rubbers, e.g., binary copolymers of hexafluoropropylene and vinylidene fluoride, and dispersed therein in such fineness that particles of the cured silicone rubber can no longer be recognized by the naked eyes only when the organic rubbery elastomer composition has a specific Mooney viscosity (ML.sub.1+4 100.degree. C.) of at least 70 to give a uniform curable rubber composition capable of being cured into vulcanized rubber articles having various properties as good as or comparable with those of the vulcanized rubber articles from the same organic rubbery elastomer without admixture of cured silicone rubber scraps.

Abstract: The invention provides a silicone rubber composition which is efficiently curable by exposure to microwaves but, different from conventional microwave-curable silicone rubber compositions compounded with a deep-colored energy-absorbing agent, is still capable of being colored in any desired color because the energy-absorbing agent compounded therein is not colored. The energy-absorbing agent used here is a silica or polyorganosilsesquioxane powder having cyanoalkyl or fluoroalkyl groups bonded to the silicon atoms.

Abstract: The present fluorosilicone rubber composition comprises a trifluoropropyl group-containing organopolysiloxane, a perfluoroalkyl group-containing organopolysiloxane, and a silica filler. This composition exhibits excellent resistance to any of nonpolar solvents, polar solvents, and fuel oils.

Abstract: The present invention provides a heat-curable silicone rubber composition to be cured by hydrosilation reactions and having outstanding physical properties, especially a high tear strength, said composition comprising(A) a polydiorganosiloxane having at least two unsaturated aliphatic hydrocarbon groups and represented by the general formula (1):R.sub.a.sup.1 SiO.sub.(4-a)/2 ( 1)wherein R.sup.1 represents a substituted or unsubstituted monovalent hydrocarbon group containing 0.01 to 15 mole % of an unsaturated aliphatic hydrocarbon group, a is a positive number of from 1.95 to 2.05.(B) a polyorganohydrogensiloxane having at least three hydrogen atoms directly bonded to silicon atom in a molecule,(C) silica filler having a specific surface area of at least 50 m.sup.2 /g, and(D) an addition reaction catalyst,(E) water, and preferably(F) an organosilane represented by the general formula:R.sub.m.sup.2 Si(OR).sub.4-mwherein R.sup.

Abstract: A silicone rubber composition comprising (A) an alkenyl-containing organopolysiloxane, (B) a polycyclic aromatic compound having at least two phenyl groups, and (C) finely divided silica is easy to process and cures to silicone rubber having low hardness while retaining good physical properties.

Abstract: An improved double-layered rubber laminate is proposed, which is an integral body consisting of a first layer of an organopolysiloxane-based rubber composition and a second layer of an acrylic rubber-based composition. When the acrylic rubber in the latter composition is not a conventional acrylic rubber but a copolymeric rubber of a (meth)acrylate ester monomer and an organosilicon monomer having, in a molecule, at least one silicon-bonded vinyl group and an ethylenically unsaturated group other than silicon-bonded vinyl groups, such as 3-methacryloxypropyl, very firm bonding can be obtained between the layers by the co-vulcanization of the laminated layers to exhibit very high resistance against delamination.

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.