摘要:
Organosols of organopolysiloxanes are prepared by adding water-soluble organic solvents or mixtures thereof or water-soluble mixtures of water-soluble and water-insoluble organic solvents to aqueous, colloidal suspensions of organopolysiloxanes obtained by adding at least one alkoxysilane and/or the partial hydrolyzate thereof, and, if appropriate, mixed with an organo(poly)siloxane free of alkoxy groups and having a maximum of 8 siloxane units per molecule, to water in the presence of emulsifiers at a maximum rate of 5 moles of organosilicon compound per hour and per liter of water, and subsequently removing the water by distillation.
摘要:
Previously cross-linked silicone elastomer particles with an organic-polymer shell are used as constituents for formulating aqueous coating compositions based on water-soluble or water-dilutable binders. The silicone elastomer particles contain: (a) 5 to 95% by weight, with respect to the total weight of the copolymer, of a nuclear polymer of general formula (R.sub.2 SiO.sub.2/2).sub.x (RSiO.sub.3/2).sub.y (SiO.sub.4/2).sub.z, in which x=5 to 99.5% by mole, y=0.5 to 95% by mole, z=0 to 30% by mole, and (b) 5 to 95% by weight, with respect to the total weight of the copolymer of a shell made of an organopolymer from mono- or poly-ethylenically unsaturated monomers; and R stands for the same or different monovalent alkyl or alkenyl radicals with 1 to 6 carbon atoms, aryl radicals or substituted hydrocarbon radicals.
摘要:
Process for the preparation of an organopolysiloxane resin, which comprisesin a first stage reacting at least one silane of the formulaR.sub.a Si(OR.sup.1).sub.4-a (I)in which a has a value of 0, 1, 2 or 3, R and R.sup.1 are monovalent organic radicals which may be the same or different and/or a partial hydrolyzate thereof, with the proviso that at least one silane of formula (I), where a is 0 or 1 and/or a partial hydrolyzate thereof is employed, and optionally an organo(poly)siloxane with water in the presence of a poly-protic acid and optionally other substances, subsequently partly neutralizing the acid by addition of a base and then distilling off at least some of the compound R.sup.1 OH formed,in a second stage reacting the homogeneous reaction mass resulting from the first stage in the presence of a base and a water-insoluble organic solvent and distilling off the water and the compound R.sup.1 OH,in a third stage, bringing the homogeneous reaction mass resulting from the second stage to a pH of between 6 and 8 by buffering with a poly-protic acid and/or salts thereof, distilling off the water and any compound R.sup.1 OH still present and filtering off the salt which has precipitated, andoptionally, in a fourth stage separating the homogeneous reaction mass resulting from the third stage from the water-insoluble organic solvent.
摘要:
A process for preparing organopolysiloxane hydrosols by mixing an organosilicon compound with water, which comprises mixing a silane of the formulaR.sub.a Si(OR.sup.1).sub.4-a (I)where a is 0, 1, 2 or 3, R can be the same or different and is a hydrogen atom or a monovalent organic radical, R.sup.1 can be the same or different and is a monovalent organic radical, and/or a partial hydrolysis product thereof and, optionally, an organodisiloxane of the formulaR.sup.2.sub.3 Si-O-SiR.sup.2.sub.3 (II)where R.sup.2 can be the same or different and is the same as R, with water in the presence of an emulsifier at a temperature below 15.degree. C.
摘要:
The invention relates to crosslinked organopolysiloxanes which contain groups which form free radicals and are built up from units of the formula[R.sub.a Si(O.sub.(3-a)/2)-R.sup.1 -X-(R.sup.1 -Si(O.sub.(3-a)/2)).sub.b R.sub.a ] (1),in whichX is a radical from the group consisting of --N.dbd.N--, --O--O--, --S--S-- and --C(C.sub.6 H.sub.5).sub.2 --C(C.sub.6 H.sub.5).sub.2 --, andR is monovalent SiC-bonded, optionally substituted C.sub.1 - to C.sub.18 -hydrocarbon radicals,R.sup.1 is divalent SiC-bonded, optionally substituted C.sub.1 - to C.sub.18 -hydrocarbon radicals which can be interrupted by divalent radicals, bonded to carbon atoms on both sides, from the group consisting of --O--, --COO--, --OOC--, --CONR.sup.2 --, --NR.sup.2 CO-- and --CO--,R.sup.2 is a hydrogen atom or a radical R,a has the values 0, 1 or 2 andb has the values 0 or 1,and further organosiloxane units. The organopolysiloxanes are used as free radical macroinitiators for grafting polymerization of ethylenically unsaturated monomers.
摘要:
Composition comprising (A) 50-99.5 wt %, based on the total weight, of A, B and C of a reaction resin or reaction resin mixture that is processed into thermosetting materials, said resin or resin mixture being liquid at temperatures in the range of 15 to 100° C. and having an average molecular weight of 200 to 500,000 and with a sufficient number of suitable reactive groups for a curing process and (B) 0.5-50 wt %, relative to the total weight of A, B and C of one or more dispersed polyorganosiloxanes that are contained in the reaction resin or reaction resin mixture homogeneously in finely distributed form as polyorganosiloxane droplets with a diameter of 0.001 to 4 μm, wherein the organopolysiloxane particle is a polymer of the general formula (R3SiO1/2)W(R2SiO2/2)X—(RSiO3/2)Y—(SiO4/2)Z, where w=0 to 20 Mol %, x=80 to 99.9 Mol %, y=0.5 to 10 Mol %, z=0 to 10 Mol %, (C) 0.1-50 wt %, based on the total weight of A, B and C of one or more silicone organo copolymers as dispersing agents that can be homogeneously dissolved or homogeneously emulsified in the reaction resin or reaction resin mixture.
摘要:
Thermoset polymer systems are toughened without compromising other polymer properties by including 0.5 to 50 weight percent of 0.001 to 0.4 μm monodisperse core/shell polymers having at least an inner core of a silicone polymer and an outer core of organopolymer.
摘要:
Redispersible core/shell elastomeric particles are prepared by a process wherein a silicone elastomer core is covered with a second silicone shell, followed by an organic polymer shell.
摘要:
Composition comprising (A) 50-99.5 wt %, based on the total weight, of A, B and C of a reaction resin or reaction resin mixture that is processed into thermosetting materials, said resin or resin mixture being liquid at temperatures in the range of 15 to 100° C. and having an average molecular weight of 200 to 500,000 and with a sufficient number of suitable reactive groups for a curing process and (B) 0.5-50 wt %, relative to the total weight of A, B and C of one or more dispersed polyorganosiloxanes that are contained in the reaction resin or reaction resin mixture homogeneously in finely distributed form as polyorganosiloxane droplets with a diameter of 0.001 to 4 μm, wherein the organopolysiloxane particle is a polymer of the general formula (R3SiO1/2)w(R2SiO2/2)x- (RSiO3/2)y- (SiO4/2)z, where w=0 to 20 Mol %, x=80 to 99.9 Mol %, y=0.5 to 10 Mol %, z=0 to 10 Mol %, (C) 0.1-50 wt %, based on the total weight of A, B and C of one or more silicone organo copolymers as dispersing agents that can be homogeneously dissolved or homogeneously emulsified in the reaction resin or reaction resin mixture.
摘要:
Particulate additives which may be added to thermoset or thermoplastic polymers while maintaining transparency comprise core/shell polysiloxane graft polymers having a silicone core, optionally an inner addition polymer core within the silicone core, and an addition polymer shell. The silicone core is derived from at least one monomer having conjugated electron pairs.