Patents by Inventor Michel Letoffe
Michel Letoffe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6521699Abstract: The invention concerns a silicon dispersion hardenable by cross-linking and useable particularly as putty, paint or film coating. The dispersion according to the instant invention contains hydroxylated condensable constituents and is free from hydrolyzable substituents capable of being transformed into volatile organic compounds, is free from volatile organic compounds and polyvinil alcohol, and contains an &agr;,&ohgr;-diOH polyorganosiloxane (A), an adherence promoter (B) with NH2 functions and OH functions, and, optionally, a catalyst (C), a surfactant (D), a cross-linking agent (E), fillers (F), a dispersing agent (G), a plasticizer (H), an antifungal agent (I), an antifoaming agent (J), a stabilizer (K) or a base (L). The invention is useful for putty or film coatings prepared with this dispersion.Type: GrantFiled: April 27, 2001Date of Patent: February 18, 2003Inventors: Michel Feder, Philippe Jost, Michel Letoffe, Marie-Cécile Duchamp
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Publication number: 20010031818Abstract: The invention concerns a silicon dispersion hardenable by cross-linking and useable particularly as putty, paint or film coating. The dispersion according to the instant invention contains hydroxylated condensable constituents and is free from hydrolyzable substituents capable of being transformed into volatile organic compounds, is free from volatile organic compounds and polyvinil alcohol, and contains an &agr;,&ohgr;-diOH polyorganosiloxane (A), an adherence promoter (B) with NH2 functions and OH functions, and, optionally, a catalyst (C), a surfactant (D), a cross-linking agent (E), fillers (F), a dispersing agent (G), a plasticizer (H), an antifungal agent (I), an antifoaming agent (J), a stabilizer (K) or a base (L). The invention is useful for putty or film coatings prepared with this dispersion.Type: ApplicationFiled: April 27, 2001Publication date: October 18, 2001Inventors: Michel Feder, Philippe Jost, Michel Letoffe, Marie-Cecile Duchamp
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Patent number: 6124235Abstract: An accelerator system for the cold crosslinking of polymers which harden on exposure to moisture by hydrolysis/condensation, comprising: (C) x parts by weight of a catalyst for crosslinking the said polymers by polycondensation, x ranging from 0.01 to 10; (E) Y parts by weight of a solid inorganic compound containing an amount y of water in the form of water of hydration and/or water adsorbed by capillary condensation, this amount y ranging from 0.5 to 40 parts by weight, and which can represent up to 70% of the weight of the said solid inorganic compound; (F) z parts by weight of fillers, z ranging from 0 to 50; (D) 100-(x+Y+z) parts by weight of a diluent or of a solvent of the said catalyst (C), the diluent or solvent having a dynamic viscosity at 25.degree. C. of the order of 50 to 200,000 mPa.s; the respective amounts of the four constituents (C), (E), (F) and (D) being such that the system obtained exists in the form of a manipulable paste.Type: GrantFiled: July 3, 1997Date of Patent: September 26, 2000Assignee: Rhone-Poulenc ChimieInventors: Michel Letoffe, Jean-Marc Pujol
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Patent number: 5681884Abstract: An accelerator system for the cold crosslinking of polymers which harden on exposure to moisture by hydrolysis/condensation, comprising: (C) x parts by weight of a catalyst for crosslinking the said polymers by polycondensation, x ranging from 0.01 to 10; (E) Y parts by weight of a solid inorganic compound containing an amount y of water in the form of water of hydration and/or water adsorbed by capillary condensation, this amount y ranging from 0.5 to 40 parts by weight, and which can represent up to 70% of the weight of the said solid inorganic compound; (F) z parts by weight of fillers, z ranging from 0 to 50; (D) 100-(x+Y+z) parts by weight of a diluent or of a solvent of the said catalyst (C), the diluent or solvent having a dynamic viscosity at 25.degree. C. of the order of 50 to 200,000 mPa.s; the respective amounts of the four constituents (C), (E), (F) and (D) being such that the system obtained exists in the form of a manipulable paste.Type: GrantFiled: September 22, 1994Date of Patent: October 28, 1997Assignee: Rhone-Poulenc ChimieInventors: Michel Letoffe, Jean-Marc Pujol
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Patent number: 5079324Abstract: Functionalized diorganopolysiloxanes containing alkoxy endgroups, well adapted for the formulation of single-component cold-vulcanizable elastomer compositions therefrom, are prepared by reacting an .alpha., .omega.-dihydroxydiorganopolysiloxane oil with a polyalkoxysilane in the presence of a catalytically effective amount of lithium hydroxide.Type: GrantFiled: November 6, 1989Date of Patent: January 7, 1992Assignee: Rhone-Poulenc ChimieInventors: Roger Cocco, Michel Letoffe, Georges Nielsen
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Patent number: 4956436Abstract: Organopolysiloxane compositions curable into elastomeric state, whether in single- or two-component form, comprise an .alpha.,.omega.-dihydroxypolydiorganopolysiloxane oil, a crosslinking agent therefor, optionally, inorganic fillers and an adhesion promoter, and a catalytically effective amount of a pentacoordinated tin monochelate produced by reacting a .beta.-dicarbonyl compound with an organotin salt.Type: GrantFiled: June 27, 1988Date of Patent: September 11, 1990Assignee: Rhone-Poulenc ChimieInventors: Michel Letoffe, Claude Millet, Serge Serafini
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Patent number: 4824924Abstract: The diorganopolysiloxane alpha, omega-diol oils are terminally alkoxylated by reacting same with a polyalkoxysilane in the presence of an organic oxime devoid of silicon atoms. The resulting functionalized oils are well adapted for the formulation of single-component, storage-stable organopolysiloxane CVE compositions.Type: GrantFiled: April 28, 1987Date of Patent: April 25, 1989Assignee: Rhone-Poulenc ChimieInventors: Michel Letoffe, Pierre-Michel Peccoux
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Patent number: 4797462Abstract: Organopolysiloxanes curable into elastomeric state, well adapted as sealing materials for a variety of substrates and useful, e.g., in the automotive industry, are comprised of a polyhydroxylated polysiloxane, a polyacyloxysilane crosslinking agent, and an effective amount of at least one calcium oxide, strontium oxide and/or barium oxide cure accelerator therefor. The subject compositions are stable for at least 10 minutes at ambient temperature and crosslink on heating and/or addition of an aqueous or liquid carboxylic acid promoter thereto.Type: GrantFiled: September 11, 1987Date of Patent: January 10, 1989Assignee: Rhone-Poulenc ChimieInventors: Michel Letoffe, Georges Barrandon
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Patent number: 4769409Abstract: Single-component diorganopolysiloxane compositions which are storage-stable in the absence of atmospheric moisture and which crosslink into silicone elastomeric state in the presence of moisture, are comprised of an alkoxy-terminated diorganopolysiloxane, a functionalization catalyst containing a primary or secondary amine group, a tin condensation catalyst, a filler material, and an effective stabilizing amount of an alkyl or aryl isocyanate-substituted diorganopolysiloxane.Type: GrantFiled: April 28, 1987Date of Patent: September 6, 1988Assignee: Rhone-Poulenc ChimieInventors: Michel Gay, Michel Letoffe, Pierre-Michel Peccoux
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Patent number: 4762879Abstract: Single-component diorganopolysiloxane compositions which are storage-stable in the absence of atmospheric moisture and which crosslink into silicone elastomeric state in the presence of moisture, are comprised of an alkoxy-terminated diorganopolysiloxane, a functionalization catalyst containing a primary or secondary amine group, a tin condensation catalyst, a filler material, and an effective stabilizing amount of an isocyanurate of the formula: ##STR1## wherein W is --CH.sub.2).sub.n N.dbd.C.dbd.O and n ranges from 1 to 12.Type: GrantFiled: April 28, 1987Date of Patent: August 9, 1988Assignee: Rhone-Poulenc ChimieInventors: Michel Letoffe, Pierre-Michel Peccoux
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Patent number: 4755579Abstract: Organopolysiloxane compositions comprising a polyhydroxylated polysiloxane and a polyacyloxysilane, whether in single- or two-component form, rapidly cure into elastomeric state (and are thus useful, e.g., as sealing materials) in the presence of a 2-carboxycarboxamide cure autoaccelerator.Type: GrantFiled: June 16, 1987Date of Patent: July 5, 1988Assignee: Rhone-Poulenc Specialites ChimiquesInventor: Michel Letoffe
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Patent number: 4748166Abstract: Storage stable, water-free, RTV organopolysiloxane adhesives curable in the presence of water or atmospheric moisture, and comprising a dihydroxydiorganopolysiloxane polymer, fillers, an amine fraction and a curing catalyst, are characterized by incorporation therein of a polyalkoxylated organosilane having the formula:R'.sub.x Si[(OCH.sub.2 CH.sub.2).sub.p OCH.sub.3 ].sub.4-xwherein R' is methyl, vinyl, allyl, methallyl or phenyl, and p and x are each one or two.Type: GrantFiled: May 28, 1986Date of Patent: May 31, 1988Assignee: Rhone-Poulenc IndustriesInventors: Alain Gautier, Bernard Laisney, Michel Letoffe
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Patent number: 4672003Abstract: Novel RTV organopolysiloxane compositions, advantageously two-component compositions, which are easily vulcanized into self-adhesive elastomers having excellent reversion properties, are comprised of (1) at least one alpha, omega-dihydroxydiorganopolysiloxane polymer having a viscosity of from about 500 to 1,000,000 mPa.s at 25.degree. C., the organic radicals of which being monovalent hydrocarbon radicals, (2) at least one filler material therefor, (3) at least one polyalkoxysilane or polyalkoxysiloxane cross-linking agent therefor, (4) a catalytically effective amount of at least one tin catalyst, and (5) at least one silane having the general formula: ##STR1## wherein R is an alkyl or alkoxy radical having from 1 to 4 carbon atoms, at least 2 of said radicals R being alkoxy radicals, R' is an alkyl radical having from 1 to 3 carbon atoms, and n is an integer of from 3 to 10.Type: GrantFiled: October 29, 1985Date of Patent: June 9, 1987Assignee: Rhone-Poulenc Specialites ChimiquesInventor: Michel Letoffe
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Patent number: 4604444Abstract: Organopolysiloxane compositions readily cross-linked into elastomers, e.g., elastomeric seals, and advantageously formulated in either one- or two-component packages, are comprised of (A) a polyhydroxylated polysiloxane, (B) a polyacyloxysilane cross-linking agent and (C) a hardening accelerator therefor, said hardening accelerator being protectively microencapsulated within impermeable outer skin membranes adopted to be chemically or physically disrupted, e.g., by heat, irradiation or mechanical breaking, to permit the release of said accelerator (C) therefrom and consequent curing of the composition.Type: GrantFiled: October 19, 1984Date of Patent: August 5, 1986Assignee: Rhone-Poulenc Specialites ChimiquesInventors: Andre Donnadieu, Michel Letoffe
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Patent number: 4532315Abstract: Organopolysiloxane compositions which rapidly harden to the elastomeric state, even at ambient temperatures, are comprised of (i) a polyhydroxylated polysiloxane, (ii) a polyacyloxysilane cross-linking agent therefor, and (iii) a hardening accelerator comprising an alkali or alkaline earth metal hydroxide. The subject compositions are useful, inter alia, for providing elastomeric seals.Type: GrantFiled: January 25, 1984Date of Patent: July 30, 1985Assignee: Rhone-Poulenc Specialites ChimiquesInventors: Michel Letoffe, Roger Favre, Patrice Perrin
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Patent number: 4525565Abstract: Provided are single component organopolysiloxane compositions which are hardenable at ambient temperatures and contain as the cross-linking agent silanes with hydrocarbonoyloxy (acyloxy) or ketoniminoxy groups. The compositions further comprise a cross-linking catalyst which is an organic derivative of titanium, e.g., a titanium ester, polytitanoxane, alkanolamine titanate, etc., or an organic derivative of zirconium, e.g., a zirconate, polyzirconate, etc. After cross-linking, the present compositions provide organopolysiloxane elastomers exhibiting good properties.The organopolysiloxane compositions are referred to as "single component" to contrast them with the two-component organopolysiloxane compositions which are not storage stable and must therefore be handled in two separate packages, which problem is overcome by the present compositions.Type: GrantFiled: July 29, 1983Date of Patent: June 25, 1985Assignee: Rhone-Poulenc Specialites ChimiquesInventors: Bernard Laisney, Michel Letoffe, Patrice Perrin, Jean Ulrich
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Patent number: 4508888Abstract: Organopolysiloxane compositions which rapidly harden to the elastomeric state, even at ambient temperatures, are comprised of (i) a polyhydroxylated polysiloxane, (ii) a polyacyloxysilane cross-linking agent therefor, and (iii) a hardening accelerator comprising water and an alkali or alkaline earth metal phosphate and/or polyphosphate. The subject compositions are useful, inter alia, for providing elastomeric seals.Type: GrantFiled: January 25, 1984Date of Patent: April 2, 1985Assignee: Rhone-Poulenc Specialites ChimiquesInventors: Michel Letoffe, Roger Favre, Patrice Perrin
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Patent number: 4143088Abstract: An organosilicon composition is disclosed which is storage-stable in the absence of moisture and is rapidly curable into elastomers with self-adherent properties in the presence of water at room temperature. Such compositions are prepared by mixing:(a) at least one .alpha.,.omega.-di(hydroxy) diorganopolysiloxane polymer,(b) at least one organosilicon resin,(c) at least one alkoxylated organosilicon compound, and(d) at least one organic titanium derivative.Type: GrantFiled: March 24, 1977Date of Patent: March 6, 1979Assignee: Rhone-Poulenc IndustriesInventors: Georges Favre, Andre Gibard, Michel Letoffe
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Patent number: 3983265Abstract: Substrates, particularly electronic connections, are protected by coating the substrate with a curable organosilicon composition based on .alpha.-.omega.-dihydroxy diorganopolysiloxanes, methyl polysiloxanes, fillers, amino organosilicon cross linking agents and optionally alkyl silicates or polysilicates, which are vulcanizable at ambient temperature or above, are improved by using a methylpolysiloxane in which the ratio of the R(CH.sub.3).sub.2 SiO.sub.0.5 units (R=C.sub.1 --C.sub.3 alkyl or vinyl) to SiO.sub.2 units is 0.4:1 to 1.2:1 and which contains 0.5 - 3.5% by weight OH groups bonded to Si and by using an amino organosilicon compound which is an aminoorganosilane of the general formula (i) (R"O).sub.3.sub.-p R'.sub.p Si[(CH.sub.2).sub.n O].sub.m (CH.sub.2).sub.t NHQ in which R' represents an alkyl group with 1 to 4 carbon atoms, a vinyl group or a phenyl group, R" represents a methyl, ethyl or methoxyethyl radical, Q represents a hydrogen atom or the radical --(CH.sub.2).sub.2 NH.sub.Type: GrantFiled: May 14, 1975Date of Patent: September 28, 1976Assignee: Rhone-Poulenc S.A.Inventor: Michel Letoffe
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Patent number: 3965280Abstract: Electrical and electronic devices are coated with an organopolysiloxane composition which consists essentially of a mixture of the following ingredients by weight:I 100 parts of a .alpha.,.omega.-dihydroxydiorganopolysiloxane polymer, of viscosity at least about 600 cPo at 25.degree.C,ii 1 to 15 parts of an organosilicon compound which is eitherA a monomer of the formula (A): R.sub.x Si[(OCH.sub.2 CH.sub.2).sub.a OR'].sub.4.sub.-x', orB a polymer resulting from the partial hydrolysis of at least one monomer of formula Si(OR').sub.4 ;iii 0.2 to 6 parts of an organic derivative of titanium, which is either:A a monomer of the formula (B): Ti[OCH.sub.2 CH.sub.2).sub.b OR"].sub.4',b a polymer resulting from the partial hydrolysis of at least one monomer of the formula Ti(OR").sub.Type: GrantFiled: May 5, 1975Date of Patent: June 22, 1976Assignee: Rhone-Poulenc S.A.Inventors: Louis Ceyzeriat, Michel Letoffe