A composition for forming a release coating is disclosed. The composition comprises (A) an organopolysiloxane comprising the reaction product of: (i) a silicone resin having a particular formula; and (ii) a cyclic siloxane; in the presence of a polymerization catalyst. The composition further comprises (B) an organopolysiloxane including an average of at least two silicon-bonded ethylenically unsaturated groups per molecule.

A resist underlayer film-forming composition includes: a polysiloxane compound including a first structural unit represented by formula (1); and a solvent. X represents a group represented by formula (2); a is an integer of 1 to 3; R.sup.1 represents a halogen atom, a hydroxy group, or a monovalent organic group having 1 to 20 carbon atoms; and b is an integer of 0 to 2; and a sum of a and b is no greater than 3. R.sup.2 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms; n is 1 or 2; R.sup.3 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; L represents a single bond or a divalent linking group; and * denotes a site bonding to the silicon atom in the formula (1). The composition is suitable for lithography with an electron beam or extreme ultraviolet ray.

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A process can be used for increasing the molecular weight of low molecular weight α,ω-polysiloxanediols. The process involves heating the low molecular weight α,ω-polysiloxanediols in the presence of acetic anhydride at temperatures of 80° C. to 220° C., preferably at temperatures of 100 to 200° C., and particularly preferably at temperatures of 120-180° C., for 1 h to 24 h, preferably for 2 h to 16 h, and particularly preferably for 3 h to 12 h. The molar amount of the silanol groups used is greater than that of the acetic anhydride used.

A process can be used for increasing the molecular weight of low molecular weight α,ω-polysiloxanediols. The process involves heating the low molecular weight α,ω-polysiloxanediols in the presence of acetic anhydride at temperatures of 80° C. to 220° C., preferably at temperatures of 100 to 200° C., and particularly preferably at temperatures of 120-180° C., for 1 h to 24 h, preferably for 2 h to 16 h, and particularly preferably for 3 h to 12 h. The molar amount of the silanol groups used is greater than that of the acetic anhydride used.

A curable organosilicon resin composition includes; (A) an organopolysiloxane having a resin structure containing 10 to 60 mol % of an R.sup.1SiO.sub.3/2 unit, 30 to 80 mol % of an (R.sup.2).sub.2SiO.sub.2/2 unit, and 1 to 30 mol % of an (R.sup.3).sub.3SiO.sub.1/2 unit. At least a part of the (R.sup.2).sub.2SiO.sub.2/2 unit is in continuous repeating units with the average number of the repeating units being 3 to 80. The organopolysiloxane has a weight average molecular weight of 5,000 to 50,000; the amount of the hydroxy groups bonded to silicon atoms is 0.001 to 1.0 mol/100 g; and the amount of the alkoxy groups, each having 1 to 10 carbon atoms, bonded to silicon atoms is 1.0 mol/100 g or less. A curable organosilicon resin composition has excellent workability, can give a cured product rapidly, and can make the cured product excellent in mechanical properties, heat resistance, crack resistance, and adhesive property, the surface tackiness being suppressed.

A curable organosilicon resin composition includes; (A) an organopolysiloxane having a resin structure containing 10 to 60 mol % of an R.sup.1SiO.sub.3/2 unit, 30 to 80 mol % of an (R.sup.2).sub.2SiO.sub.2/2 unit, and 1 to 30 mol % of an (R.sup.3).sub.3SiO.sub.1/2 unit. At least a part of the (R.sup.2).sub.2SiO.sub.2/2 unit is in continuous repeating units with the average number of the repeating units being 3 to 80. The organopolysiloxane has a weight average molecular weight of 5,000 to 50,000; the amount of the hydroxy groups bonded to silicon atoms is 0.001 to 1.0 mol/100 g; and the amount of the alkoxy groups, each having 1 to 10 carbon atoms, bonded to silicon atoms is 1.0 mol/100 g or less. A curable organosilicon resin composition has excellent workability, can give a cured product rapidly, and can make the cured product excellent in mechanical properties, heat resistance, crack resistance, and adhesive property, the surface tackiness being suppressed.

The present invention relates to a process for producing and for regenerating siloxane hydrogen carrier compounds.

The present invention relates to a polysiloxane copolymer including a structural unit derived from a siloxane-based polymer and a structural unit derived from a silane-based monomer, and a method for preparing the same. The polysiloxane copolymer of the present invention has excellent heat resistance, flexibility, transparency, photosensitivity, durability and the like, and may be widely used as a material in an optical field or/and an electronic field.

The present invention relates to a polysiloxane copolymer including a structural unit derived from a siloxane-based polymer and a structural unit derived from a silane-based monomer, and a method for preparing the same. The polysiloxane copolymer of the present invention has excellent heat resistance, flexibility, transparency, photosensitivity, durability and the like, and may be widely used as a material in an optical field or/and an electronic field.

The present invention relates to a process for producing high-purity hydrosilylation products, and also to the products that may be produced by this process and to the use thereof as surfactants.