Dow Corning Corporation

Dow Corning S.a.

Northwestern University

Dow Silicones Corporation

Francois De Buyl

Patrick Leempoel

Valerie Smits

Damien Deheunynck

Michael Backer

Tobin Jay Marks

Toshio Saruyama

Mamoru Tachikawa

Frederic Gubbels

Peng-Fei Fu

Michael Wolfgang Backer

Richard Alan Palmer

Robert Harold Krahnke

Hiroshi Adachi

Timothy B Lueder

Gary Thomas Burns

Gregory Chambard

Victor Baily

Jean De La Croix Habimana

Sarah Louise O'Hare

Thomas Chaussee

Kazutoshi Okabe

Martijn A Beukema

Iain A Mackinnon

Eric Damme

Patrick Deglasse

Thierry Cooremans

Olivier Debever

Vincent Rerat

Geraldine Durand

Julien Renaud

Luo Cheng Zhang

Tobin J Marks

Gary Burns

Martin Beukema

John G Francis

Donna M Perry

Elizabeth Van Den Berg

A room temperature curable composition is disclosed. The composition can be used as an encapsulation/potting material. The composition comprises: (i) at least one condensation curable silyl terminated polymer having at least one silicon bonded hydroxyl functional group per molecule; (ii) a cross-linker having at least two hydrolysable groups and selected from certain silanes and/or silyl functional molecules; and (iii) a condensation catalyst selected from the group of titanates and/or zirconates. The molar ratio of the sum of moisture present in the composition and total silicon bonded hydroxyl groups:the catalyst ('the molar ratio') is &#x3e;7:1. When the molar ratio is from &#x3e;7:1 to 10:1, the molar ratio of total silicon bonded hydroxyl groups:total hydrolysable groups is between 0.1:1 to 0.3:1. When the molar ratio is &#x3e;10:1, the molar ratio of total silicon bonded hydroxyl groups:total hydrolysable groups is between 0.1:1 to 0.5:1.

Elastomeric compositions and their applications

The invention provides a composition comprising a polyolefin and a polyorganosiloxane in which at least 50 mole % of the siloxane units are D units as herein defined and which contains at least one unsaturated group, characterized in that the unsaturated group is group of the formula &#x2014;X&#x2014;CH&#x2550;CH&#x2014;R&#x2033; (I) or &#x2014;X&#x2014;C&#x2261;C&#x2014;R&#x2033; (II), in which X represents a divalent organic linkage having an electron withdrawing effect with respect to the &#x2014;CH&#x2550;CH&#x2014; or &#x2014;C&#x2261;C&#x2014; bond and/or containing an aromatic ring or a further olefinic double bond or acetylenic unsaturation, the aromatic ring or the further olefinic double bond or acetylenic unsaturation being conjugated with the olefinic unsaturation of &#x2014;X&#x2014;CH&#x2550;CH&#x2014;R&#x2033; or with the acetylenic unsaturation of &#x2014;X&#x2014;C&#x2261;C&#x2014;R&#x2033; and R&#x2033; represents hydrogen or a group having an electron withdrawing effect or any other activation effect with respect to the &#x2014;CH&#x2550;CH&#x2014; or &#x2014;C&#x2261;C&#x2014; bond.

Organopolysiloxanes containing an unsaturated group

Methods for producing a silyl-functionalized polyolefin with silyl monomer incorporation are provided. The method includes reacting a silicon-containing olefin with an &#x3b1;-olefin, in the presence of a catalytic amount of a group IV catalyst for a time sufficient to produce a silyl-functionalized polyolefin.

Method for producing silyl-functionalized polyolefins and silyl-functionalized polyolefins with silyl monomer incorporation

The invention provides a process for grafting silane or silicone functionality onto a polyolefin, comprising reacting the polyolefin with an unsaturated monomer (A) containing an olefinic &#x2014;C&#x2550;C&#x2014; bond or acetylenic &#x2014;C&#x2261;C&#x2014; bond and a reactive functional group X in the presence of means capable of generating free radical sites in the polyolefin and with an organosilicon compound (B) having a functional group Y which is reactive with the functional group X of the unsaturated monomer (A), characterized in that the unsaturated monomer (A) contains an aromatic ring or a further olefinic double bond or acetylenic unsaturation, the aromatic ring or the further olefinic double bond or acetylenic unsaturation being conjugated with the olefinic &#x2014;C&#x2550;C&#x2014; or acetylenic &#x2014;C&#x2261;C&#x2014; unsaturation of the unsaturated monomer (A).

Modified polyolefins

This invention relates to the treatment of a carbon based filler with a hydrolysable silane to modify the surface of the filler. It also relates to a carbon based filler modified by treatment with a hydrolysable silane, and to polymer compositions containing such a modified carbon based filler.

Treatment of filler with silane

A polyorganosiloxane polyoxyalkylene block copolymer having one or more polyorganosiloxane blocks and one or more polyoxyalkylene blocks linked to each other via divalent radicals which comprises at least two silicon-bonded alkoxy groups, preferably of the form PS (A PO)(A PS), wherein PO is a polyoxyalkylene block, PS represents a polyorganosiloxane block, A is a divalent radical, m and n have independently a value of at least 1, comprising at least one alkoxy-substituted siloxane unit of the formula (R')(OR)&#x2014;SiO, wherein R represents an alkyl group having 1 to 4 carbon atoms and each R&#x2032; represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, or an alkoxy group of the formula &#x2014;OR and q has a value of 0, 1 or 2, provided at least two silicon-bonded groups OR are present in the block copolymer. Also provided is a curable composition of the above which may comprise a condensation catalyst and a hydrophilic polymer network made from curing the composition in the presence of moisture, which exhibit interesting reversible hydrophilic properties.

Polymer and polymer compositions

The invention relates to a process for grafting hydrolysable silane groups to a polyolefin in which ethylene units, if present, form less than 50% by weight of the total polyolefin. The polyolefin is reacted with an unsaturated silane, having at least one hydrolysable group bonded to Si, or a hydrolysate thereof, in the presence of means capable of generating free radical sites in the polyolefin. The unsaturated silane has the formula R&#x2033;&#x2014;CH&#x2550;CH&#x2014;Z (I) or R&#x2033;&#x2014;C&#x2261;C&#x2014;Z (II) in which Z represents an electron-withdrawing moiety substituted by a &#x2014;SiRR'group wherein R represents a hydrolysable group; R&#x2032; represents a hydrocarbyl group having 1 to 6 carbon atoms; a has a value in the range 1 to 3 inclusive; and R&#x2033; represents hydrogen or a group having an electron withdrawing or any other activation effect with respect to the &#x2014;CH&#x2550;CH&#x2014; or &#x2014;C&#x2261;C&#x2014; bond. The use of an unsaturated silane of the formula R&#x2033;&#x2014;CH&#x2550;CH&#x2014;Z (I) or R&#x2033;&#x2014;C&#x2261;C&#x2014;Z (II) in carrying out the grafting reaction on the polyolefin may give enhanced grafting yield compared to grafting with an olefinically unsaturated silane such as vinyltrimethoxysilane not containing an electron withdrawing moiety Z. The invention permits to provide a silane-modified polyolefin having a high grafting efficiency while limiting/preventing polymer degradation by chain scission. The silane-modified polyolefin can be further reacted with a polar surface, a filler or a polar polymer or reacted on itself to crosslink the polyolefin and obtain enhanced physical properties of the composites made thereof.

A moisture curable composition capable of cure to an elastomeric body, comprising a polymeric material having not less than two hydroxyl or hydrolyzable groups an alkoxysilane curative and a catalyst comprising:

Organosiloxane compositions

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.

Process for the manufacturing of organopolysiloxane compositions

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. A chain extender may also be included with the reaction mixture of step A and/or the reaction product of step B. The polydiorganosiloxanes are suitable for use in sealant compositions.

Method for preparing polydiorganosiloxanes partially end-blocked with

Alkoxy-functional room temperature vulcanizing (RTV) compositions, curable in the presence of moisture, comprising polymers containing on average at least 1.2 alkoxysilyl chain terminations per molecule, a tetraalkoxytitanium compound containing on average greater than 90 mole percent of the alkoxy groups as tertiary amyloxy groups, a filler, and an alkoxysilane. The addition of these components in amounts to satisfy defined molar ratios provide alkoxy-functional RTV compositions having both improved storage stability and improved green strength upon curing.

Alkoxy-functional RTV compositions with increased green strength and

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.

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.4 represents a monovalent aliphatic chain having 1 to 6 carbon atoms, the most preferred groups R' being tertiary butyl and t-amyl groups. The compositions cure without need for the presence of a chelating agent and the preferred compositions cure quickly and do not yellow.

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Hoeilaart, Belgium

Francois De Buyl