Dow Corning S.a.

Dow Corning Corporation

Ecole Polytechnique

Dow Corning Europe Sa

Patrick Leempoel

Pierre Descamps

Pere Roca I Cabarrocas

Pavel Bulkin

Thibault Kervyn De Meerendre

Dmitri Daineka

Francois De Buyl

Eric Damme

Andre R Colas

Takao Takemasa

Patrick Deglasse

Fabrice Lebecq

Jean-Marc Gilson

Jean-Paul Hautekeer

Thien Hai Dao

Jean De La Croi Habimana

Thibault Kervyn De Meerendré

An apparatus is described for depositing a film on a substrate from a plasma. The apparatus comprises an enclosure, a plurality of plasma generator elements disposed within the enclosure, and means, also within the enclosure, for supporting the substrate. Each plasma generator element comprises a microwave antenna having an end from which microwaves are emitted, a magnet disposed in the region of the said antenna end and defining therewith an electron cyclotron resonance region in which a plasma can be generated, and a gas entry element having an outlet for a film precursor gas or a plasma gas. The outlet is arranged to direct gas towards a film deposition area situated beyond the magnet, as considered from the microwave antenna, the outlet being located in, or above, the hot electron confinement envelope.

Method and apparatus for forming a film by deposition from a plasma

A plasma excitation device is described for use in depositing a film on a substrate from a plasma formed by distributed electron cyclotron resonance. The device comprises a microwave antenna having an end from which microwaves are emitted, a magnet disposed in the region of the said antenna end and defining therewith an electron cyclotron resonance region in which a plasma can be generated, and a gas entry element having an outlet for a film precursor gas or a plasma gas. The outlet is arranged to direct gas towards a film deposition area situated beyond the magnet, as considered from the microwave antenna.

Device for forming a film by deposition from a plasma

A method is described of depositing film of an amorphous or microcrystalline material, for example silicon, from a plasma on to a substrate. Microwave energy is introduced into a chamber as a sequence of discrete microwave pulses, a film precursors gas is introduced into the chamber as a sequence of discrete gas pulses, and gas for generating atomic hydrogen is supplied to the chamber at least during each microwave pulse. Each microwave pulse is followed in non-overlapping fashion with a precursor gas pulse, and each precursor gas pulse is followed by a period during which there is neither a microwave pulse nor a precursor gas pulse.

Method of forming a film by deposition from a plasma

A method is described for forming a film of amorphous silicon (a-Si:H) on a substrate by deposition from a plasma. The substrate is placed in an enclosure, a film precursor gas is introduced into the enclosure, and unreacted and dissociated gas is extracted from the enclosure so as to provide a low pressure in the enclosure. Microwave energy is introduced into the gas within the enclosure to produce a plasma therein by distributed electron cyclotron resonance (DECR) and cause material to be deposited from the plasma on the substrate. The substrate is held during deposition at a temperature in the range 200-600&#xb0; C., preferably 225-350&#xb0; C. and a bias voltage is applied to the substrate at a level to give rise to a sheath potential in the range &#x2212;30 to &#x2212;105V, preferably using a source of RF power in the range of 50-250 mW/cm2 of the area of the substrate holder.

Deposition of amorphous silicon films by electron cyclotron resonance

A method is described of forming a film of an amorphous material on a substrate () by deposition from a plasma. The substrate () is placed in an enclosure, a film precursor gas is introduced into the enclosure through pipes (), and unreacted and dissociated gas is extracted from the enclosure through pipes () so as to provide a low pressure therein. Microwave energy&#x2014;is introduced into the gas within the enclosure as a sequence of pulses at a given frequency and power level to produce a plasma therein by distributed electron cyclotron resonance (DECR) and cause material to be deposited from the plasma on the substrate. The frequency and/or power level of the pulses is altered during the course of deposition of material, so as to cause the bandgap to vary over the thickness of the deposited material.

Film deposition of amorphous films with a graded bandgap by electron cyclotron resonance

A method is described of forming a film of an amorphous material on a substrate by deposition from a plasma. The substrate is placed in an enclosure, a film precursor gas is introduced into the enclosure, and unreacted and dissociated gas is extracted from the enclosure so as to provide a low pressure therein. Microwave energy is introduced into the gas within the enclosure to produce a plasma therein by distributed electron cyclotron resonance (DECR) and cause material to be deposited from the plasma on the substrate. The said flow rate of the film precursor gas is altered during the course of deposition of material, so as to cause the bandgap to vary over the thickness of the deposited material.

Method for forming a film with a graded bandgap by deposition of an amorphous material from a plasma

An apparatus is provided for producing a plasma for a work surface, for example to deposit material thereon. The apparatus comprises an enclosure which contains an ionizable gas, a plurality of plasma excitation devices each of which is arranged to enable microwaves to travel from a first end thereof to a second end and radiate therefrom into the gas, and means for generating a magnetic field in the gas. A source of microwaves feeds microwaves to the first ends of the excitation devices. In use, regions exist within the said gas where the direction of the electric vector of the microwaves is non-parallel to the lines of the magnetic field, and the magnetic field has value B, and the microwaves have a frequency f such as to substantially satisfy the relationship: B=&#x3c0;mf D e where m and e are the mass and charge respectively of an electron.

Method and apparatus for creating a plasma

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 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. The chain-extended organopolysiloxanes are suitable for use in sealant compositions.

Process for preparing chain-extended organopolysiloxanes

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

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. Also disclosed is a method of forming an elastomeric mass between surfaces which is adherent to at least two such surfaces which method comprises introducing between the surfaces said moisture curable composition.

Organosiloxane compositions

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.

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. Also disclosed is a method of forming an elastomeric mass between surfaces which is adherent to at least two such surfaces which method comprises introducing between the surfaces said moisture curable composition.

Adhesion method employing organosiloxane compositions

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.

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.

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Brussels, Belgium

Patrick Leempoel