Provided is a polysiloxane composition containing a polysiloxane compound including a constitutional unit represented by Formula (1) and at least one of a constitutional unit of Formula (2) and a constitutional unit of Formula (3), and a solvent.

[(R.sup.x).sub.bR.sup.1.sub.mSiO.sub.n/2]  (1)

[(R.sup.y).sub.cR.sup.2.sub.pSiO.sub.q/2]  (2)

[SiO.sub.4/2]  (3)

Here, R.sup.x is a monovalent group represented by Formula (1a) (X is a hydrogen atom or an acid-labile group, a is an integer of 1 to 5, and a broken line represents a bond), R.sup.y is a monovalent organic group having 1 to 30 carbon atoms, which contains any one of an epoxy group, an oxetane group, an acryloyl group, and a methacryloyl group.

##STR00001##

Novel compositions and systems for closure of wounds are disclosed. The compositions provide devices of improved flexibility and elasticity and are readily applied to wound sites or over wound closure devices. The present invention is also directed to a novel platinum catalyst for use in such compositions. The catalyst provides for rapid curing on topical surfaces such as skin and bonds to such surfaces in about 2-5 minutes.

A composition of the present invention contains the following components A to C: A. a linear terminal-reactive polydimethylsiloxane; B. a thermally conductive filler including the following B1, B2, and B3 in an amount of 800 to 2500 parts by mass with respect to 100 parts by mass of the component A; and C. a curing catalyst in a catalytic amount. The component B includes the following: B1. a thermally conductive filler that has an average particle size of 0.1 to 1.0 μm and is surface treated with a surface treatment agent containing a reactive group having no unsaturated bond; B2. a thermally conductive filler that has an average particle size of 1.0 to 10 μm and is surface treated with a surface treatment agent containing a reactive group having an unsaturated bond; and B3. a thermally conductive filler that has an average particle size of 10 to 100 μm and is surface treated with the surface treatment agent containing a reactive group having no unsaturated bond or the surface treatment agent containing a reactive group having an unsaturated bond. Thus, the thermally conductive silicone composition and the sheet formed by using this composition have a high strength.

According to the present invention, an ultraviolet curable silicone composition for stereolithography, which contains (A) an organopolysiloxane that has two groups represented by formula (1) ##STR00001##
(wherein each R.sup.1 independently represents a monovalent hydrocarbon group having 1-20 carbon atoms; R.sup.2 represents an oxygen atom or the like; R.sup.3 represents an acryloyloxyalkyl group or the like; p represents a number satisfying 0≤p≤10; and a represents a number satisfying 1≤a≤3) in each molecule,
(B) an organopolysiloxane resin that is composed of (a) a unit represented by formula (2) ##STR00002##
(wherein R.sup.1-R.sup.3, a and p are as defined above), (b) an R.sup.4.sub.3SiO.sub.1/2 unit (wherein each R.sup.4 independently represents a monovalent hydrocarbon group having 1-10 carbon atoms) and (c) an SiO.sub.4/2 unit, and wherein the molar ratio of the total of the unit (a) and the unit (b) to the unit (c) is within the range of 0.6-1.2:1 and
(C) a photopolymerization initiator has a viscosity that is applicable to a stereolithography system such as lifting system and forms a cured product which has excellent physical properties of rubber.

Provided is a silicone rubber composition that allows for both the securing of time for filling materials and an improvement in productivity which is achievable due to a short curing time, and that has excellent reproducibility of curing properties. The silicone rubber composition contains (a) an organopolysiloxane having an alkenyl group, (b) a peroxide cross-linking agent, and (c) a heat stabilizer, wherein (c) includes a compound represented by general formula (1). In formula (1), R.sub.1 represents hydrogen or a methyl group, R.sub.2, R.sub.3, R.sub.4, and R.sub.5, each independently represent a C1-9 alkyl group, and R.sub.6 represents hydrogen or a methyl group.

##STR00001##

A photocurable resin composition for imprinting including a polymerizable compound, and a photopolymerization initiator, wherein the polymerizable compound includes a siloxane bond in a molecule, and includes at least one polymerizable functional group, and a ratio of oxygen atoms bonded to a single silicon atom, among oxygen atoms bonded to a silicon atom included in the polymerizable compound, is 10 mol % or less.

A photocurable resin composition for imprinting including a polymerizable compound, and a photopolymerization initiator, wherein the polymerizable compound includes a siloxane bond in a molecule, and includes at least one polymerizable functional group, and a ratio of oxygen atoms bonded to a single silicon atom, among oxygen atoms bonded to a silicon atom included in the polymerizable compound, is 10 mol % or less.

A polyolefin-polydiorganosiloxane block copolymer may be prepared by hydrosilylation reaction.

Provided are a self-welding high dielectric silicone rubber composition and a self-welding high dielectric tape. The self-welding high dielectric silicone rubber composition comprises: (A) 100 parts by mass of an organopolysiloxane represented by an average composition formula (1) and having, in a molecule, at least two alkenyl groups bonded to silicon atoms, R.sup.1.sub.nSiO.sub.(4-n)/2 (1), (in the formula, R.sup.1 represents the same or different, unsubstituted or substituted monovalent hydrocarbon group and n is a positive number of 1.95 to 2.04); (B) 10 to 100 parts by mass of hydrophobic fumed silica having a specific surface area obtained by the BET adsorption method of 50 m.sup.2/g or larger; (C) 100 to 300 parts by mass of a conductive complex oxide; (D) 0.1 to 50 parts by mass of a boric acid or a boric acid compound; (E) 1 to 10 parts by mass of a diorganopolysiloxane capped at both molecular terminals with alkoxy groups; and (F) 0.01 to 10 parts by mass of a curing agent comprising an acyl organic peroxide. The self-welding high dielectric silicone rubber composition can be hot-air vulcanized under normal pressure by extrusion molding or roll forming with calender rolls.

Provided are an excellently convenient ultraviolet-curable organopolysiloxane causing no surface curing inhibition even when cured in the atmosphere; a composition containing such organopolysiloxane; and a cured product of such composition. The organopolysiloxane is represented by the following formula (1):

##STR00001##

wherein each R.sup.1 independently represents a monovalent hydrocarbon group having 1 to 10 carbon atoms or a group represented by the following formula (2), each molecule has at least one group represented by the following formula (2), m is a number satisfying 1≤m≤10,000,

##STR00002##

wherein R.sup.2 represents a group having at least one of an acryloyl group, methacryloyl group, acryloyloxyalkyl group or methacryloyloxyalkyl group, R.sup.3 represents a divalent hydrocarbon group having 1 to 20 carbon atoms.