摘要:
A process for producing a linear organotetrasiloxane comprises the step of hydrolyzing a dihalotetrasiloxane in the presence of an organic compound having at least one epoxy radical. The process prevents effectively the by-production of high molecular weight or cyclic condensates, and yields a linear organotetrasiloxane having a high OH number and high activity.
摘要:
A novel room temperature-curable organopolysiloxane-based composition is proposed which is capable of giving a surface coating highly insusceptible to surface stain even by exposure over years. The composition comprises: (A) a block copolymer composed of dimethylsiloxane units and trifunctional siloxane units of which the organic group is a phenyl group or a fluorine containing aliphatic group, in a specified molar proportion; (B) an organosilane compound having hydrolyzable groups; and (C) a polyoxyalkylene-modified organosiloxane compound of the formula (Me.sub.3 SiO--).sub.2 SiR.sup.4 --C.sub.3 H.sub.6 --(--O--R.sup.5 --).sub.b --O--SiR.sup.6.sub.a X.sub.3-a, in which Me is a methyl group, R.sup.4 is a methyl group or trimethylsiloxy group, R.sup.5 is an ethylene group or propylene group, R.sup.6 is a monovalent hydrocarbon group, X is a hydrolyzable group, the subscript a is zero or 1 and the subscript b is a positive integer not exceeding 50, with optional addition of a condensation catalyst.
摘要:
The invention provides a foamable organopolysiloxane composition capable of giving, by foaming and curing at room temperature, a silicone rubber foam of high foaming expansion having very uniform and dense cellular structure. The composition is prepared by a process comprising the steps of: (A) compounding an .alpha.,.omega.-dihydroxy dimethylpolysiloxane with a reinforcing silica filler, hexamethyl disilazane and water as the hydrolysis agent of the silazane to give a compound; (B) removing ammonia in the compound formed by the hydrolysis of the silazane compound as completely as possible; and (C) compounding the compound with a polyhydroxy methylpolysiloxane, an organohydrogenpolysiloxane and a platinum compound as a catalyst for the dehydrogenation reaction between the silanolic hydroxy groups and the silicon-bonded hydrogen atoms to produce hydrogen as the foaming gas.
摘要:
Disclosed herein are a carbon fiber-reinforced carbon composite material composed of carbon as a matrix and carbon fiber as a reinforcement, and also a process for producing the same. The composite material is produced by coating nonwoven fabrics of carbon fiber or a blend of carbon fiber and organic fiber with a filler-containing liquid, laminating the nonwoven fabrics one over another, and subjecting the laminated nonwoven fabrics to needle punching repeatedly with a plurality of needles, thereby yielding a prepreg of three-dimensional structure, and carbonizing and calcining the thus obtained prepreg.
摘要:
The essential components in the inventive room temperature-curable organopolysiloxane composition are: (A-1) a diorganopolysiloxane of which each terminal silicon atom has a silanolic hydroxy group or two alkoxy groups; (A-2) a filler; (A-3) an alkenyloxy silane, e.g. methyl tri)isopropenyloxy)silane; (A-4) a guanidino-containing organosilicon compound, e.g. 3-(tetramethylguanidino)propyl trimethoxy silane; (A-5) an alcohol, e.g. methyl or ethyl alcohol; (B) an organosilicon compound having a silicon-bonded hydrogen atom; and (C) an organic tin compound as a catalyst. By virtue of the unique formulation above, the composition is very stable in storage in a moisture-free condition for a long period of time without losing the high curability when exposed to a moisture-containing atmosphere.
摘要:
The invention provides a room temperature-curable organopolysiloxane composition curable into a rubbery elastomer, which has excellent storage stability under a moisture-free condition without losing high curability. The composition comprises, in addition to the conventional essential ingredients of a hydroxy- or alkoxy-terminated diorganopolysiloxane, filler, triisopropenyloxy silane compound as a crosslinking agent and a guanidino-containing organosilicon compound as a curing aid, an amino-containing silane compound such as MeSi[NH--C.sub.3 H.sub.6 --Si(OEt).sub.3 ].sub.3 and MeSi[NH--C.sub.2 H.sub.4 NHC.sub.3 H.sub.6 --Si(OMe).sub.3 ].sub.3.
摘要翻译:本发明提供可固化到橡胶弹性体中的室温可固化的有机基聚硅氧烷组合物,其在无湿度条件下具有优异的储存稳定性,而不损失高固化性。 除了作为交联剂的填充剂,作为交联剂的三异丙烯基氧基硅烷化合物和作为固化助剂的含胍基的有机硅化合物的常规必需成分之外,还包含含氨基的硅烷化合物,例如 MeSi [NH-C3H6-Si(OEt)3] 3和MeSi [NH-C2H4NHC3H6-Si(OMe)3] 3。
摘要:
The room temperature-curable organopolysiloxane composition of the invention capable of giving a cured rubber can be used advantageously as an insulating material in electric and electronic instruments without causing troubles in contact points which is unavoidable with conventional compositions. The inventive composition is formulated with (a) a diorganopolysiloxane terminated at the molecule molecular chain ends each with a silanolic hydroxy group, (b) an alkenyloxy, e.g. isopropenyloxy, containing silane and (c) a guanidino-substituted organosilicon compound and these components are specified either by the upper limit of the content of low molecular constituents having a specified vapor pressure or higher or the upper limit of the vapor pressure of the compound per se so that the electric contact points near the insulation with the composition are free from exposure to the vapor of organosilicon compounds which may be deposited as an oxide of silicon by sparks.
摘要:
The silicone rubber composition of the invention essentially comprises (a) a silanolic hydroxy-terminated diorganopolysiloxane, (b) a hydrolyzable vinyl silane compound such as a vinyl trialkoxysilane and (c) an organopolysiloxane having at least two mercapto groups in the form of, for example, 3-mercaptopropyl groups, in a molecule. The composition can be cured by two different mechanisms of crosslink formation one by the condensation reaction between the silanol groups in (a) and the hydrolyzable groups in (b) in the presence of atmospheric moisture and the other between the vinyl groups in (b) and mercapto groups in (c) under irradiation with ultraviolet light. The two-way cruability of the composition greatly expands the application fields of the silicone rubber composition.
摘要:
The invention relates to an apparatus for incising on a film to be processed the precise contour of a required photographic image so as to obtain a process block for prints in which such photographic image is to be inserted. The apparatus comprises a data input unit capable of detecting the precise contour by causing a light pen to trace the general contour of a required image on a photocopy; an output unit capable of incising the contour on a film to be processed by receiving signals of the positions of the precise contour detected by the input unit; and a control unit capable of performing a control operation, such as relay, comparison, etc. of the signals between the input unit and the output unit.
摘要:
Printing ink compositions which are suitable for use in the method of dry-planographic printing on a high-speed web offset press are provided wherein an ink vehicle comprises from 1 to 70% by weight of a silicone-modified phenolic resin prepared by reacting an oil-soluble solid phenolic resin with an amino group-containing organopolysiloxane. Said ink compositions are capable of producing copy sheets without the occurrence of scumming and the piling of ink throughout a long continuous operation by the said printing method.