DOW TORAY CO., LTD.

Provided is a hot-melt curable silicone composition that forms a cured product that can be cured at a temperature of 100° C. or lower, has excellent storage stability, is relatively hard from curing, and has low surface tack, and a sheet or film formed from the same. The curable silicone composition comprises: (A) a solid organopolysiloxane resin that contains at a mass ratio of 0:100 to 90:10 (Al) an organopolysiloxane resin having a curing reactive functional group and containing 20 mol % or more of a Q unit (i.e., a SiO 4/2 unit), and (A2) an organopolysiloxane resin not having a curing reactive functional group and containing 20 mol % or more of a Q unit; (B) 10 to 100 parts by mass of a straight-chain or branched organopolysiloxane having a curing reactive functional group and is liquid or has plasticity; (C) an organohydrogenpolysiloxane; and (D) a photoactivated hydrosilylation reaction catalyst.

Provided is a curing reactive organopolysiloxane composition that forms a pressure-sensitive adhesive layer having excellent curing properties, a wide range of designable viscoelastic properties such as storage elastic modulus (G′) and the like, and practically sufficient pressure-sensitive adhesive strength and tensile adhesive strength. The organopolysiloxane composition comprises: (A) an organopolysiloxane having an alkenyl group; (B) an organopolysiloxane resin with 9 mol % or less of hydroxyl groups or the like relative to all silicon atoms in a molecule or resin mixture thereof; (C) an organohydrogenpolysiloxane; (D) an organic silicon compound having an alkenyl group; and (E) a hydrosilylation reaction catalyst. A ratio (molar ratio) of the substance amount of SiH groups in component (C) relative to the sum of alkenyl groups in components (A), (B) and (D) is 1.0 or more.

Provided is an ultraviolet-curable composition containing silicon atoms, wherein the composition has a high ability to adjust the mechanical properties of the cured product thereof, and has excellent workability and high adhesion to a substrate even for solvent-free application. This disclosure provides an ultraviolet-light curable composition and a use thereof. The composition contains: (A) 1-99 parts by mass of a compound having at least one (meth)acryloxy group and hydroxyl group in one molecule and having no silicon atom; (B) 1-99 parts by mass of an organopolysiloxane having at least two alkenyl groups in one molecule and having no ultra-violet-curable functional group; and (C) 0-80 parts by mass of a compound having at least one (meth)acryloxy group in the molecule and having no hydroxyl group, on the basis of 100 parts by mass of the total mass of the composition, and contains substantially no organic solvent in the composition.

A precast concrete molded body is provided, which is a cured product of a concrete composition. The concrete composition comprises: a microcapsule; cement; and at least one type of aggregate. The microcapsule is provided with a core-shell structure having i) a core made of a water repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell made of a silicon-based network polymer containing silica units. The concrete composition contains 0.01 to less than 0.5 parts by weight of microcapsules per 100 parts by weight of cement. Thereby, a precast concrete molded body can be provided, having high strength, as well as at least one of the following properties: air content stability, substance penetration prevention, and freeze-thaw resistance.

[OBJECT] To provide an organopolysiloxane having favorable fine patterning properties (including coatability), a favorable alkali solubility and a favorable high energy beam-curability, and capable of forming a cured film having a high transparency and a practically sufficient mechanical strength when cured, and to provide, along with the use thereof, a high energy beam-curable composition containing the organopolysiloxane. [SOLUTION] Provided are a curable branched organopolysiloxane and a use thereof, wherein the curable branched organopolysiloxane is represented by an average unit formula (1): (R 3 SiO 1/2 ) a (R 2 SiO 2/2 ) b (RSiO 3/2 ) c (SiO 4/2 ) d (O 1/2 Z) e (1) (wherein R is a group selected from a monovalent hydrocarbon group, an alkoxy group, a hydroxyl group, and a phenolic hydroxyl group-containing group; 0≤a, 0≤b, 0<c, 0≤d, 0≤e, 0.8≤c/(a+b+c+d+e); and the molecule has at least one phenolic hydroxyl group-containing group therein), and wherein the curable branched organopolysiloxane has a weight average molecular weight of 4,000 or less and a polydispersity of 1.3 and less, and preferably has a cage-like molecular structure.

Provided is a release control agent containing a silicone resin having a weight average molecular weight based on standard polystyrene by gel permeation chromatography of 3,000 to 6,000 and expressed by the average unit formula: (R 1 3 SiO 1/2 ) a (SiO 4/2 ) 1.0 , wherein each R 1 independently represents an alkyl group with 1 to 6 carbon atoms, and “a” represents a number from 0.5 to 1.5, and (B) a diorganopolysiloxane having at least two silicon-bonded alkenyl groups in a molecule and/or (C) an α-olefin with 12 to 24 carbon atoms. Also provided is a releasable film-forming silicone composition containing the release control agent. The releasable film-forming silicone composition forms a releasable film with little change in release force and that does not reduce the residual adhesive strength of a pressure sensitive adhesive (PSA) after long-term aging in a state adhered to the PSA despite exhibiting a relatively large release force with respect to the PSA.

Provided herein is a light diffusing material having excellent light transmittance, light diffusion properties, and mechanical properties. The light diffusing material comprises a curable organopolysiloxane composition, comprising: A) an organopolysiloxane having reactive groups; B) one or more inorganic fillers; and C) an organosilicon compound different from component A), and comprising component(s) C1) and/or C2). Component C1) is an organosilicon compound having a reactive functional group that can bond with component A), a hydrolyzable silyl group and/or a silicon atom-bonded hydroxyl group, and two or more silicon atoms, in the molecule. Component C2) is an organosilicon compound having a reactive functional group with three or more carbon atoms, which can bond with component A), a hydrolyzable silyl group and/or a silicon atom-bonded hydroxyl group, and one or more silicon atoms, in the molecule. The mass of component B) is 30 to 95% relative to the mass of the overall composition.

Provided herein is a light diffusing material having excellent light transmittance, light diffusivity, and mechanical properties. The light diffusing material comprises a curable organopolysiloxane composition, comprising: A) an organopolysiloxane having reactive groups; B) one or more inorganic fillers; and C) an organosilicon compound that differs from component A), and comprising component(s) C1) and/or C2). Component C1) is an organosilicon compound having a reactive functional group that can bond with component A), a hydrolyzable silyl group and/or a silicon atom-bonded hydroxyl group, and two or more silicon atoms, in the molecule. Component C2) is an organosilicon compound having a reactive functional group with three or more carbon atoms, which can bond with component A), a hydrolyzable silyl group and/or a silicon atom-bonded hydroxyl group, and one or more silicon atoms, in the molecule. The mass of component B) is 30 to 95% relative to the mass of the overall composition.

Performance requirements of electroactive polymer materials used for transducer devices include dielectric breakdown strength, Young's modulus, dielectric constant, thickness, and electromechanical instability. There are correlation relationships therebetween but definitions of the correlation relationships have not been achieved. Therefore, it is necessary to search for an excellent material by trial and error, which requires a great deal of work. Disclosed herein is a curable elastomer composition that includes a compound having a high dielectric functional group. A cured product of the composition satisfies the following formula: E = α ⁡ ( Y ε 0 ⁢ ε r ) 0.5 where E is the dielectric breakdown strength in the range of 50 V/μm to 200 V/μm, α is a constant in the range of 0.4 to 0.9, Y is Young's modulus and is in the range of 0.001 MPa to 10 MPa, ε γ is a specific dielectric constant and is 100 or less, and ε 0 represents the dielectric constant of vacuum.

An ultraviolet (UV) curable organopolysiloxane composition with excellent workability when applied to a substrate is provided, in which a product obtained by curing the composition has a low dielectric constant. The UV curable organopolysiloxane composition comprises (A) one or more organosiloxane and/or organopolysiloxane having an average of two or more UV reactive functional groups in one molecule, and (B) one or more organosilane, organosiloxane, and/or organopolysiloxane having one UV reactive functional group in one molecule. An organic solvent is not included in the composition. In addition to components (A) and (B), the composition can comprise one or a plurality of additives selected from a group consisting of: (D1) nonionic surfactants not containing a silicon atom and are not acrylic; (D2) nonionic surfactants containing a silicon atom and having an HLB value of 4 or less; and (D3) silicone oils with a viscosity of 90 mPa-s or less at 25° C.