Abstract: There is disclosed a polycarbonate and polysiloxane block copolymer includes 1 to 50 percent by mass of a siloxane portion derived from a polysiloxane block represented by the following formula (I) and 50 to 99 percent by mass of a carbonate portion derived from a polycarbonate block represented by the following formula (II). There can be provided a novel polycarbonate and polysiloxane block copolymer capable of readily imparting excellent flame retardance, and a flame retardant resin composition.

Abstract: There is disclosed a polycarbonate and polysiloxane block copolymer includes 1 to 50 percent by mass of a siloxane portion derived from a polysiloxane block represented by the following formula (I) and 50 to 99 percent by mass of a carbonate portion derived from a polycarbonate block represented by the following formula (II). There can be provided a novel polycarbonate and polysiloxane block copolymer capable of readily imparting excellent flame retardance, and a flame retardant resin composition.

Abstract: A curable silicone resin composition is provided which is useful as a material for optical devices or parts, insulation material for electronic devices or parts, or coating material, and which produces a cured product having high hardness and strength and further having good optical transmission in the short wavelength region. The composition includes (A) an aromatic hydrocarbon compound having at least two hydrogen atoms bonded to silicon atoms with the silicon atoms being bonded to the hydrocarbon skeleton of the aromatic hydrocarbon compound, (B) a cyclic siloxane compound having at least two silicon atom-bonded alkenyl groups, and (C) a hydrosilylation reaction catalyst, or (D) an aromatic hydrocarbon compound having at least two alkenyl groups bonded to silicon atoms with the silicon atoms being bonded to the hydrocarbon skeleton of the aromatic hydrocarbon compound, (E) a cyclic siloxane compound having at least two silicon atom-bonded hydrogen atoms, and (C) a hydrosilylation reaction catalyst.

Abstract: A method for removing an acidic gas from a raw gas containing the acid gas by contacting the raw gas with an aqueous alkanol amine solution, characterized in that a composition comprising an organopolysiloxane containing a polyoxyalkylene group and a fine silica powder is caused to be present. In some embodiments, a composition comprising the above-mentioned organopolysiloxane and a fine silica powder is added appropriately according to the state of foaming in an acidic gas removing reaction system from the outside of the system, or use is made of an alkanol amine containing in advance a composition comprising the above-mentioned organopolysiloxane and a fine silica powder. In preferred embodiments, the fine silica powder has a specific surface area of 50 m2/g or more, and/or the composition comprising the above-mentioned organopolysiloxane and a fine silica powder is used in an amount of 0.1 to 5000 ppm relative to the alkanol amine.

Abstract: A curable silicone resin composition is provided which is useful as a material for optical devices or parts, insulation material for electronic devices or parts, or coating material, and which produces a cured product having high hardness and strength and further having good optical transmission in the short wavelength region. The composition includes (A) an aromatic hydrocarbon compound having at least two hydrogen atoms bonded to silicon atoms with the silicon atoms being bonded to the hydrocarbon skeleton of the aromatic hydrocarbon compound, (B) a cyclic siloxane compound having at least two silicon atom-bonded alkenyl groups, and (C) a hydrosilylation reaction catalyst, or (D) an aromatic hydrocarbon compound having at least two alkenyl groups bonded to silicon atoms with the silicon atoms being bonded to the hydrocarbon skeleton of the aromatic hydrocarbon compound, (E) a cyclic siloxane compound having at least two silicon atom-bonded hydrogen atoms, and (C) a hydrosilylation reaction catalyst.

Abstract: A polycarbonate polymer and resin composition having excellent transparency and abrasion resistance, comprising a mixture of (i) a polycarbonate polymer having a repeating unit having a specific grafted polysiloxane structure, and (ii) from 0 to 20 wt % of a diorganopolysiloxane. The polycarbonate polymer is obtained by reacting (a) a specific polysiloxane compound and (b) a specific bisphenol compound with (c) a carbonate ester forming compound.

Abstract: Proposed is a novel polysiloxane-polyether block copolymer having excellent heat resistance, which is characterized by the molecular structure consisting of repetition of diorganopolysiloxane units and polyoxyalkylene units having a bisphenol linkage of the formula --O--Pn--CMe.sub.2 --Pn--O-- in the unit, Pn being a 1,4-phenylene group and Me is a methyl group. This polysiloxane-polyether block copolymer can be prepared by conducting a hydrosilation reaction between a diorganopolysiloxane terminated at each molecular chain end with a silicon-bonded hydrogen atom and a polyoxyalkylene compound having the bisphenol linkage in the molecule and terminated at each molecular chain end with an alkenyl group or, preferably, allyl group in the presence of a platinum catalyst.

Abstract: Provided is a thermoplastic fluorosilicone resin of the average compositional formula (1):(RfCH.sub.2 CH.sub.2 SiO.sub.3/2).sub.x (C.sub.6 H.sub.5 SiO.sub.3/2).sub.y (SiO.sub.2).sub.z ( 1)wherein Rf is a perfluoroalkyl group having 1 to 10 carbon atoms, and x, y, and z are 0.2.ltoreq.x.ltoreq.0.95, 0<y.ltoreq.0.8, 0.ltoreq.z.ltoreq.0.05, and x+y+z=1 and having a softening point of 50.degree.-200.degree. C. The fluorosilicone resin is useful for microcapsulating a platinum catalyst for prolonging the pot life of an addition type organopolysiloxane composition and can be used as a coating agent for forming a weather resistant, stainproof, water repellent coating.

Abstract: A curable resin composition containing (a) a homo- or copolymer of an organohydrogenpolysiloxane macromonomer, (b) an alkenyl group-containing polymer, and (c) a hydrosilylation catalyst is disclosed. The organohydrogenpolysiloxane macromonomer may be incorporated into a single polymer entity together with an alkenyl group-containing monomer unit to produce a self-crosslinkable copolymer.

Abstract: Coating agents for electrophotography carriers are disclosed which are resistant to wear, peel-off, cracks, and prevent the occurrence of a spent phenomenon, and which possess a durability for a long period of use and a superior stability in the carrier charge characteristics. The coating provides long lifetime electrophotography carriers which possess reduced temperature dependency and improved stability in the carrier charge characteristics.The coating agents for the electrophotography carrier are characterized by having an organopolysiloxane expressed by the formula below as a main component:R.sub.a.sup.f R.sub.b.sup.1 Si(OR.sup.2).sub.c O.sub.(4-(a+b+c))/2IwhereinR.sup.f is C.sub.p F.sub.2p+1 Q;p is 1-12;Q is a bivalent organic group with 2-12 carbon atoms;R.sup.1 is alkyl with 1-12 carbon atoms or phenyl;R.sup.2 is H or alkyl with 1-6 carbon atoms; anda, b and c are numbers satisfying the following conditions:0<a.ltoreq.1, 0.ltoreq.b<2, 0.ltoreq.c.ltoreq.3, and 0.ltoreq.a+b+c.ltoreq.4.

Abstract: A wet frictional material having a high heat resistance, excellent durability and superior initial conformability. The wet frictional material contains a fiber base material, a filler, a frictional adjustment agent and a thermosetting synthetic resin. The thermosetting synthetic resin comprises a silicone resin represented by the following average formula. The silicone resin contains a trifunctional unit (RSiO.sub.3/2) (where R represents a substituted or unsubstituted monovalent hydrocarbon group) in an amount of from 40 to 100 mol % of units constituting the silicone resin:(R.sup.1).sub.a (OR.sup.2).sub.b SiO.sub.(4-a-b)/2where R.sup.1 represents a substituted or unsubstituted monovalent hydrocarbon group, and R.sup.2 represents a hydrogen atom or an organic group having from 1 to 10 carbon atoms, and 0.2.ltoreq.a.ltoreq.1.8 and 0<b.ltoreq.1.0).

Abstract: Novel organopolysiloxanes have the average compositional formula (1): ##STR1## wherein X is a monovalent substituent containing a polyoxyethylene group, Y is a 3-(meth)acryloxypropyl group, R.sup.1 is a C.sub.1-6 alkyl group or phenyl group, a=0 or 1, 1.ltoreq.b.ltoreq.20, 0.ltoreq.c.ltoreq.10, 1.ltoreq.d.ltoreq.10, and 1.ltoreq.a+c.ltoreq.10. They are prepared by effecting addition reaction of an aliphatic unsaturated compound containing a polyoxyethylene group to corresponding organohydrogenpolysiloxanes.

Abstract: Disclosed is an electrophotographic toner binder which comprises a silicone-grafted copolymer produced by radical copolymerization of an organopolysiloxane compound represented by the following general formula (I) and another monomer capable of undergoing the radical copolymerization with said organopolysiloxane compound: ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group; R.sup.2 represents a divalent hydrocarbon group containing 1 to 12 carbon atoms, which may have one or more of an oxygen atom interposed in its carbon chain; R.sup.3 represents a monovalent hydrocarbon group containing 1 to 6 carbon atoms; m represents 1, 2 or 3; and n represents an integer from 20 to 200.

Abstract: A coating composition for carriers which are adapted for use in electrophotography is described. The composition comprises an organopolysiloxane of the following average unit formula (1)R.sup.1.sub.a Si(OR.sup.2).sub.b O.sub.[4-(a+b)]/2 (1)wherein R.sup.1 represents an alkyl group having from 1 to 10 carbon atoms or a phenyl group, R.sup.2 represents a hydrogen atom or an alkyl, alkenyl or alkoxyalkyl group, each having from 1 to 10 carbon atoms for the alkyl and alkenyl and from 2 to 10 carbon atoms for the alkoxyalkyl, a is a value of 0.8.ltoreq.a.ltoreq.1.8, b is a value of 0<b<3, an organosilane of the following general formula (2) serving as a crosslinking agent for the organopolysiloxane(CH.sub.3).sub.2 SiX.sub.2 (2)wherein each X represents an alkenoxy group or oxime having from 2 to 10 carbon atoms, and a curing catalyst for the organopolysiloxane. Carriers having core particles and a cured film of the composition formed on individual particles are also described.

Abstract: A curable resin composition comprises (A) a silicone resin having epoxy and phenyl groups and at least two hydrolyzable silyl groups and/or silanol groups in one molecule, (B) a vinyl polymer having a group or groups reactive with the epoxy group in the ingredient (A), and (C) a condensation catalyst for the silicone resin.

Abstract: A process for preparing a polyester-modified silicone resin comprises mixing an alkoxysilane and/or its hydrolyzate, i.e. an alkoxysiloxane, and a polyester resin having at least two hydroxyl groups in the molecule, and subjecting the mixture to hydrolysis and polycondensation reactions in the presence of an acid catalyst. This process is performed by a continuous one-stage reaction sequence including hydrolysis, polycondensation and modification and is simplified. A composition comprising the polyester-modified silicone resin is also described. The composition comprising organozinc compounds along with the modified silicone resin is significantly improved in heat resistance and color-difference.

Abstract: A blend of (A) an acrylic, polyester or epoxy resin having at least two alkenyl or alkynyl groups in a molecule, (B) an organic silicon compound having at least two hydrogen atoms each directly attached to a silicon atom in a molecule, and (C) a hydrosilylaion catalyst is blended with (D) an organic iron or aluminum compound to form a hydrosilylative composition. Component (D) scavenges a catalyst poison, permitting components (A) and (B) to undergo hydrosilylation reaction with the aid of catalyst (C).

Abstract: The present invention provides a coating agent for an electrophotographic carrier comprising as a major component a copolymer of at least one monomer selected from the organopolysiloxanes represented by the following general formulas 1, 2, and 3 with other polymerizable monomer: ##STR1## wherein the general formulas 1, 2, and 3, R.sup.1 is hydrogen atom or methyl group; R.sup.2 is C.sub.1 -C.sub.10 alkyl or phenyl group; R.sup.3 is R.sup.2 or CH.sub.2 .dbd.C(R.sup.1)COOC.sub.3 H.sub.6 ; n, p, and q are defined as n.gtoreq.3, p.gtoreq.0, q.gtoreq.3, and p<q; and r is an integer of 2-20.The coating agent for an electrophotographic carrier resists the formation of wear, peeling, cracks, and the like, which can also prevent the spent condition from occurring and thus, permits use over a long period of time; and it provides a long-life electrophotographic carrier in which the carrier charge characteristics exhibit low temperature dependency.

Abstract: Novel organopolysiloxanes containing both a (meth)acryl group and a carboxyl group in a molecule are well compatible with organic resins and useful as resin modifiers.

Abstract: A curable resin composition comprising (a) an acrylic, polyester, epoxy or polyol resin having a plurality of alkynyl groups, (b) an organohydrogenpolysiloxane, and (c) an amount of platinum catalyst effective to catalyze the crosslink reaction between (a) and (b). The composition is useful for coating and molding purposes and gives a cured product having excellent acid resistance, water resistance and other properties.