Dow Corning Corporation

Dow Corning Ireland Limited

Bhukandas Parbhoo

Roberto Bortolin

Pierre Chevalier

Scott S Brown

Simon R Hurford

Andrew James Goodwin

Timothy Rex Bunce

Kyuha Chung

Yeong Joo Lee

Stuart Leadley

Manoj Kumar Chaudhury

A method of forming a powder and/or discrete gel particles of a compound selected from the group of a metallic oxide, a metalloid oxide, a mixed oxide, an organometallic oxide, an organometalloid oxide, an organomixed oxide resin, and/or an organic resin from one or more respective organometallic precursor(s), organometalloid precursor(s) and/or organic precursors and mixtures thereof, comprising the steps of passing a gas into a means for forming excited and/or unstable gas species (), typically an atmospheric plasma generating means; treating said gas such that upon leaving said means the gas comprises excited and/or unstable gas species which are substantially free of electrical charges at a temperature of between 10&#xb0; C. and 500&#xb0; C. A gaseous and/or liquid precursor is then introduced () into said excited and unstable gas species in a downstream region external () to the means for forming excited and/or unstable gas. The interaction between the precursor and the excited and unstable gas species results in the formation of a powder and/or discrete gelled particles which are subsequently collected. The particles prepared by the method may be subsequently functionalised.

Manufacture of resins

This invention relates to a method of functionalizing a powdered substrate. The method comprises the following steps, which method comprises passing a gas into a means for forming excited and/or unstable gas species, typically an atmospheric pressure plasma or the like and treating the gas such that, upon leaving said means, the gas comprises excited and/or unstable gas species which are substantially free of electric charge. The gas comprising the excited and/or unstable gas species which are substantially free of electric charge is then used to treat a powdered substrate and a functionalizing precursor in a downstream region external to the means for forming excited and/or unstable gas, wherein neither the powdered substrate nor the functionalizing precursor have been subjected to steps (i) and (ii) and wherein said functionalizing precursor is introduced simultaneously with or subsequent to introduction of the powdered substrate. Preferably the method takes place in a fluidized bed.

Functionalisation of particles

A method of forming a gel and/or powder of a metallic oxide, metalloid oxide and/or a mixed oxide or resin thereof from one or more respective organometallic liquid precursor(s) and/or organometalloid liquid precursor(s) by oxidatively treating said liquid in a non-thermal equilibrium plasma discharge and/or an ionised gas stream resulting therefrom and collecting the resulting product. The non-thermal equilibrium plasma is preferably atmospheric plasma glow discharge, continuous low pressure glow discharge plasma, low pressure pulse plasma or direct barrier discharge. The metallic oxides this invention particularly relates to are those in columns 3and 4of the periodic table namely, aluminium, gallium, indium, tin and lead and the transition metals. The metalloids may be selected from boron, silicon, germanium, arsenic, antimony and tellurium. Preferred metalloid oxide products made according to the process of the present invention are in particular oxides of silicon including silicone resins and the like, boron, antimony and germanium.

Gel and powder making

A method for creating adhesion includes plasma treating two substrates and thereafter contacting the substrates. The method can be used on a variety of dry surfaces. The method is used to adhere nonadhesive surfaces such as a cured silicone with a ceramic or semiconductor.

Method for creating adhesion during fabrication of electronic devices

Release modifier composition useful in release coating compositions comprising a fluorosilicone compound having perfluoroalkyl groups and at least three silicon-bonded hydrogen atoms and a MQ resin having at least one alkenyl group. Release coating compositions comprising the release modifier compositions and a method for modifying the release force of release coating compositions is also claimed.

Silicone release coating compositions

A release modifier for silicone release compositions comprising a MQ resin consisting essentially of units of the formulae

Silicone release composition

A release modifier which comprises (i) a MQ resin consisting essentially of units of the formulae SiO.sub.2 and R.sub.3 SiO.sub.1/2 wherein R denotes a monovalent hydrocarbon group having up to 3 carbon atoms, a hydrogen atom, a c.sub.2-5 alkenyl group of the formula --R'CH.dbd.CH.sub.2, provided there is at least one group --R'CH.dbd.CH.sub.2 present per MQ molecule and (ii) a .alpha.,.omega.-diolefin having the general formula CH.sub.2 .dbd.CH--(CH.sub.2).sub.n --CH.dbd.CH.sub.2, wherein n denotes an integer with a value of from 4 to 18 gives improved release force over prior art controlled release additives. Also claimed is a solventless release composition based on siloxanes having SiH groups and a catalyst in addition to the release modifier.

Silicone release compositions

A method of making silethynyl polymers having units of the general formula--(R.sub.2 SiC.tbd.C)-- wherein each R independently denotes a hydrogen atom, an alkyl, aryl or alkenyl group or a substituted alkyl, aryl or alkenyl group having up to 18 carbon atoms comprises adding a lithium salt of one or more diethynylsilanes of the general formula R.sub.2 Si(C.tbd.CH).sub.2 to one or more dihalosilanes of the general formula R.sub.2 SiX.sub.2 where X is a halogen atom and allowing the components to react. Copolymers with alternating units can be made. Linear polymers are made preferentially. Limiting the use of solvent increases the percentage of linear polymers produced.

Method of making silethynyl polymers

A method of making silethynyl polymers having units of the general formula --(R.sub.2 SiC.tbd.C)-- wherein each R independently denotes a hydrogen atom, an alkyl, aryl or alkenyl group or a substituted alkyl, aryl or alkenyl group having up to 18 carbon atoms comprises adding a lithium salt of one or more diethynylsilanes of the general formula R.sub.2 Si(C.tbd.CH).sub.2 to one or more dihalosilanes of the general formula R.sub.2 SiX.sub.2 where X is a halogen atom and allowing the components to react. Copolymers with alternating units can be made. Linear polymers are made preferentially. Limiting the use of solvent increases the percentage of linear polymers produced.

A method of making silethynyl-siloxane copolymers having R.sub.2 SiC.tbd.C units and R.sub.2 SiO units wherein each R denotes H or a C.sub.1-16 hydrocarbon or substituted hydrocarbon group, comprises ring-opening copolymerization in the presence of a catalytic amount of a lithium compound, of cyclic siloxanes and cyclic silethynyl polymers. Novel silethynyl-siloxane copolymers of the formula ##STR1## are also disclosed wherein R' denotes --C.tbd.CH or R and a and b are at least 1.

Method of making silethynyl-siloxane copolymers

Organosilbutadiyne polymers having the general formula R'-[(R).sub.2 Si--C.tbd.C--C.tbd.C].sub.n -(R).sub.2 SiR' wherein R is a hydrogen atom, a hydrocarbon group or a substituted hydrocarbon group, R' is hydroxyl, halogen or R and n is an integer, are made by (A) reacting HC.tbd.C--C.dbd.CH--OZ with alkyllithium in a molar ratio of 1:3 wherein Z denotes an alkyl group having up to 6 carbon atoms followed by (B), further reacting the product of (A) with one or more dihalosilanes.

Method of making organosilbutadiyne polymers

Organosilbutadiyne polymers having the general formula R'-[(R).sub.2 Si-C.tbd.C-C.tbd.C].sub.n -(R).sub.2 SiR' wherein R is a hydrogen atom, a hydrocarbon group or a substituted hydrocarbon group, R' is hydroxyl, halogen or R and n is an integer, are made by (A) reacting bis(trialkylsilyl)butadiyne with alkyllithium in a molar ratio of 1:2 followed by (B), further reacting the product of (A) with one or more dihalosilanes.

Cyclic silethynyl polymers, having at least 4 silicon atoms per polymer, have the average formula ##STR1## Preferably x has a value of 5 or 6, and each R is independently methyl or phenyl. They are prepared by reacting a lithium salt of one or more diehtynylsilanes with one or more dihalosilanes. These polymers are useful for example in semi- or photoconductive applications.

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Barry, United Kingdom

Bhukandas Parbhoo