Abstract: Urea-functional organopolysiloxanes containing units of the formula RnSiO(4-n)/2??(I), where R is a radical R1 or a radical —OR2 or a radical Q, Q is a urea-functional radical of the formula —R5—[NR4—R6—]xNR4R3??(II), where the radicals R4 are identical or different and are each a radical R4? or a radical Ru, where R4? is hydrogen or a monovalent C1-C6-hydrocarbon radical where Ru is radical of the formula —C(?O)—NH2, and where at least one urea-functional radical Q having a radical Ru is present per molecule are prepared by reacting amino-functional organopolysiloxanes comprising units of the formula R?nSiO(4-n)/2??(IV), where A is an amino-functional radical of the formula —R5—[NR4?—R6—]xNR4?R3??(V), with the proviso that at least one amino-functional radical A is present per molecule in the organopolysiloxanes made up of units of the formula (III), with ortho-substituted aryl carbamates of the formula R7—Ar—O—C(?O)—NH2??(VI), where Ar is an ortho-substituted aryl radical.

Abstract: Urea-functional organopolysiloxanes containing units of the formula RnSiO(4-n)/2 ??(I), where R is a radical R1 or a radical —OR2 or a radical Q, Q is a urea-functional radical of the formula —R5—[NR4—R6—]xNR4R3 ??(II), where the radicals R4 are identical or different and are each a radical R4? or a radical Ru, where R4? is hydrogen or a monovalent C1-C6-hydrocarbon radical where Ru is radical of the formula —C(?O)—NH2, and where at least one urea-functional radical Q having a radical Ru is present per molecule are prepared by reacting amino-functional organopolysiloxanes comprising units of the formula R?nSiO(4-n)/2 ??(IV), where A is an amino-functional radical of the formula —R5—[NR4?—R6—]xNR4?R3 ??(V), with the proviso that at least one amino-functional radical A is present per molecule in the organopolysiloxanes made up of units of the formula (III), with ortho-substituted aryl carbamates of the formula R7—Ar—O—C(?O)—NH2 ??(VI), where Ar is an ortho-substituted aryl radical.

Abstract: Organopolysiloxanes containing a large proportion of methylene-bonded polar groups have high relative permittivities, and are especially useful as thermally stable dielectrics. A methoxymethyl alkoxysilane starting material is easily synthesized, and can be incorporated into the polymers by conventional methods known in organosilicon chemistry.

Abstract: Alkali metal silanolates are prepared by a process in which alcohol and water are removed from an alkali metal silanolate hydrolysis mixture in two steps, the second removal step occurring at a pressure lower than the first removal step.

Abstract: Polymerizable siloxy-substituted silanes are obtained in high yield and purity by adding a substituted alkoxysilane to a mixture of disiloxane, acetic acid, sulfuric acid, and optionally an acidic catalyst, separating a product phase from an acidic phase, adding hexamethyldisilazane to the product phase and filtering off a resulting salt, followed by distillation.

Abstract: Siloxy-substituted silane-containing polymerizable silicones are prepared in high purity by metering a substituted alkoxysilane into a mixture of disiloxane, acetic acid, and acid catalyst, adding acetyl chloride, separating an acidic phase from a product phase, and adding hexamethyldisilazane to the product phase, which is then distilled.

Abstract: Siloxy-substituted silane-containing polymerizable silicones are prepared in high purity by metering a substituted alkoxysilane into a mixture of disiloxane, acetic acid, and acid catalyst, adding acetyl chloride, separating an acidic phase from a product phase, and adding hexamethyldisilazane to the product phase, which is then distilled.

Abstract: Polymerizable siloxy-substituted silanes are obtained in high yield and purity by adding a substituted alkoxysilane to a mixture of disiloxane, acetic acid, sulfuric acid, and optionally an acidic catalyst, separating a product phase from an acidic phase, adding hexamethyldisilazane to the product phase and filtering off a resulting salt, followed by distillation.

Abstract: Ionic organosilicon compounds comprising siloxane units of the formulaA.sub.a R.sub.b X.sub.c SiO.sub.(4-a-b-c)/2 (I),in whichR is an identical or different, optionally halogenated hydrocarbon radicals having 1 to 12 carbon atoms or radicals of the formulae--R'--((NHCH.sub.2 CH.sub.2).sub.o --(N.sup.+ H.sub.2 CH.sub.2 CH.sub.2).sub.p --N.sup.(x+q-2)+ H.sub.x R".sub.q).sub.d-1 (II)--R'--(SH).sub.d-1 (III)or--R'--(Z--C (O)--CR'"=CH.sub.2).sub.d-1 (IV)in whichR', R", Z, R'", o, p, q, x, d, X and A have the meaning given in claim 1 anda is 0 or 1,b is 0, 1, 2 or 3,c is 0, 1, 2 or 3and the sum a+b+c is.ltoreq.