Abstract: This invention provides a process for the manufacture of organopolysiloxane compositions, an in particular sealants, comprising mixing a polymer, preferably silicone, a surface active filler, an organosilane such as a cross-linker, a catalyst and an adhesion promoter, in which the organosilane (iii) is mixed with surface active filler (ii) prior to the introduction of the adhesion promoter. The resulting sealant compositions have improved adhesion properties.

Abstract: This invention provides a process for the manufacture of organopolysiloxane compositions, an in particular sealants, comprising mixing a polymer, preferably silicone, a surface active filler, an organosilane such as a cross-linker, a catalyst and an adhesion promoter, in which the organosilane (iii) is mixed with surface active filler (ii) prior to the introduction of the adhesion promoter. The resulting sealant compositions have improved adhesion properties.

Abstract: This specification describes and claims a process for preparing chain-extended organopolysiloxanes. The process comprises the steps of: A) mixing organopolysiloxanes having at least one silicon-bonded hydroxyl group per molecule with a polymerization catalyst to form a mixture, B) allowing the mixture of step A to react so as to produce a reaction product comprising polymerized organopolysiloxanes of which some have at least one silicon-bonded hydroxyl group per molecule and C) allowing the silicon-bonded hydroxyl group containing organopolysiloxanes of the reaction product of step B to react with a nitrogen-containing silylating agent capable of chain-extending to produce a chain-extended organopolysiloxane. Preferably the silylating agent is a cyclosilazane. Organopolysiloxanes having terminal groups other than silicon-containing hydroxyl groups and which are capable of equilibrating with the mixture of step A and/or the reaction product of step B may also be introduced prior to step C.

Abstract: This specification describes and claims a method for producing polydiorganosiloxanes partially end-blocked with substituted silethylene groups. The method comprises the steps of: A) mixing a hydroxyl end-blocked polydiorganosiloxane with a silicon-containing compound having at least two silicon-bonded hydrogen atoms and a --Si(R').sub.3 end-blocked siloxane in the presence of an acidic polymerisation catalyst to form a mixture wherein each R' independently denotes a monovalent hydrocarbon or halohydrocarbon having 1 to 6 carbon atoms, B) conducting a reaction with the mixture of step A so as to produce a polydiorganosiloxane having at least one silicon-bonded hydrogen atom and at least one --Si (R').sub.3 group and C) adding a substituted alkenylsilane in the presence of a hydrosilylation catalyst to the reaction product obtained from step B to form a polydiorganosiloxane partially end-blocked with substituted silethylene groups.

Abstract: A moisture curable composition comprises a mixture and/or a reaction product of a polymeric material having not less than two groups bonded to silicon which are hydroxyl or hydrolyzable groups, an alkoxysilane curative, an adhesion promoter and catalyst material for catalyzing the condensation reaction between the polymeric material and the alkoxysilane curative. The adhesion promoter comprises a silicone-organic copolymer consisting of units (I) according to the general formula R.sub.a R'SiO.sub.(4-a)/2 and units (II) according to the general formula R.sub.b R'SiO.sub.(3-b)/2 where R represents a monovalent hydrocarbon group and R' represents an oxyalkylene chain R.sup.6 (C.sub.2 H.sub.4 O).sub.x (C.sub.3 H.sub.6 O).sub.y Z in which R.sup.6 represents a hydrocarbon linkage to a silicon atom, Z represents H or a carboxylic acid residue.

Abstract: A composition curable in presence of atmospheric moisture to an elastomeric body, comprising (A) the product formed by mixing a polymeric material having at least two groups bonded to silicon which are hydroxyl or alkoxy group and an alkoxysilane curative and (B) a titanium compound according to the general formula Ti(OR).sub.x (OR').sub.y (OR*).sub.z where x is 0 to 0.4 inclusive, y is 0 to 3.9, z is 0.1 to 4, x+y+z=4, R* is 2,4-dimethyl-3-pentyl, R' represents a monovalent tertiary aliphatic hydrocarbon group, and JR represents a monovalent linear aliphatic hydrocarbon group having 1 to 6 carbon atoms. The compositions cure quickly and do not yellow.

Abstract: A moisture curable composition comprises a mixture and/or a reaction product of a polymeric material having not less than two groups bonded to silicon which are hydroxyl or hydrolyzable groups, an alkoxysilane curative, an adhesion promoter and catalyst material for catalyzing the condensation reaction between the polymeric material and the alkoxysilane curative. The adhesion promoter comprises a silicone-organic copolymer consisting of units (I) according to the general formula R.sub.a SiO.sub.(4-a)/2 and units (ii) according to the general formula R.sub.b R'SiO.sub.(3-b)/2 where R represents a monovalent hydrocarbon group and R' represents an oxyalkylene chain R.sup.6 (C.sub.2 H.sub.4 O).sub.x (C.sub.3 H.sub.6 O).sub.y Z in which R.sup.6 represents a hydrocarbon linkage to a silicon atom, Z represents H or a carboxylic acid residue.

Abstract: The specification describes and claims a composition curable in presence of atmospheric moisture to an elastomeric body, comprising (A) the product formed by mixing a polymeric material having at least two groups bonded to silicon which are hydroxyl or hydrolysable (eg alkoxy) groups and an alkoxysilane curative and (B) a compound according to the general formula M?OR!.sub.x ?OR'!.sub.y where M represents a metal having a valency of 4 selected from Group IVB of the Periodic Table and is preferably titanium, x has a value from 0 to 1, y has a value from 3 to 4 and (x+y)=4, R' represents a monovalent tertiary aliphatic hydrocarbon group and R represents a monovalent linear aliphatic hydrocarbon group having 1 to 6 carbon atoms which is different from R'. Preferred compounds (B) are those in which R' represents C(R.sup.2 R.sup.3 R.sup.4) in which each of R.sup.2, R.sup.3 and R.sup.

Abstract: A moisture curable composition is claimed comprising (a) a condensation product of a polyacid chloride with an alkylene or oxyalkylene polymer having substituent groups condensible therewith with an organosilicon compound having at least one silicon-bonded group --R(NHR.sup.1).sub.m NH.sub.2 e.g. a material of the general formula ##STR1## wherein each R may be the same or different and represent a linking group, each R' represents a group --R(NHR.sup.1).sub.m NH.sub.2, a hydrolysable group R", a group R'" or a group R'Si(OSiR.sup.1.sub.2).sub.s --O-- where R'" is a hydrocarbon group, m is from 0 to 10 and s is from 0 to 1500 and (b) a curative. Preferred materials are amino silanes in which R" is an oximo, alkoxy, alkenyloxy or alkoxyalkoxy group, --R(NHR.sup.1).sub.m NH.sub.2 is aminopropyl and m is 0. The aminosilane is preferably .gamma.-aminopropyltrimethoxysilane or .gamma.-aminopropyltriethoxysilane and the organic polymer is a polyoxyalkylene glycol.

Abstract: The specification describes and claims a moisture curable composition comprising hydroxypolysiloxane, silane curing agent, finely divided filler (preferably calcium carbonate), catalyst, and as rheological additive, a polymer having on its polymer chain at least one carboxylic acid anhydride group. Preferred rheological additives are polybutadiene polymers treated with e.g. maleic acid anhydride. These products have improved rheology for sealant use.

Abstract: The specification describes and claims curable polysiloxane compositions filled with a mixture of two types of finely divided calcium carbonate. The curable polysiloxane comprises 100 parts by weight of a hydroxypolysiloxane with from 5 to 12 parts by weight of a curing agent therefore comprising a silane of the formula R.sub.a R'.sub.b Si or a siloxane having units ##EQU1## wherein each R represents a monovalent hydrocarbon group, each R' represents an hydroxy, alkoxy, or alkoxyalkoxy group, a+b=4, a has a value 0 or 1, b has a value 3 or 4, c has a value 1, 2 or 3 and a+c is not greater than 3 as exemplified by methyl trimethoxy silane, together with a catalytic amount of a titanium or tin compound for promoting curing of the product in presence of moisture of the atmosphere.

Abstract: Organopolysiloxane compositions which are curable to elastomers via an addition reaction of unsaturated bonds to silicon-bonded hydrogen atoms in the presence of a group VIII metal catalyst have improved adhesion, without inhibiting their curing, by incorporating an organosilicon compound of the general formula(RO).sub.c R.sub.3-c SiO(R.sub.2 SiO).sub.x (R'RSiO).sub.y (R"RSiO).sub.z SiR.sub.3-c (OR).sub.cwherein R is a hydrocarbon, R' has olefinic unsaturation and at least 6 carbon atoms, R" contains an epoxy group and x, y and z are at least 1, z being 2 if c is 0.