Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/56—Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic System
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/0801—General processes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic System
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/0834—Compounds having one or more O-Si linkage
  • C07F7/0838—Compounds with one or more Si-O-Si sequences
  • C07F7/0872—Preparation and treatment thereof
  • C07F7/0876—Reactions involving the formation of bonds to a Si atom of a Si-O-Si sequence other than a bond of the Si-O-Si linkage
  • C07F7/0878—Si-C bond
  • C07F7/0879—Hydrosilylation reactions
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic System
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/18—Compounds having one or more C—Si linkages as well as one or more C—O—Si linkages
  • C07F7/1804—Compounds having Si-O-C linkages
  • C07F7/1872—Preparation; Treatments not provided for in C07F7/20
  • C07F7/1876—Preparation; Treatments not provided for in C07F7/20 by reactions involving the formation of Si-C linkages
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/38—Polysiloxanes modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0091—Complexes with metal-heteroatom-bonds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/06—Preparatory processes
  • C08G77/08—Preparatory processes characterised by the catalysts used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/12—Polysiloxanes containing silicon bound to hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/20—Polysiloxanes containing silicon bound to unsaturated aliphatic groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
  • C08G77/24—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen halogen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/70—Siloxanes defined by use of the MDTQ nomenclature

Definitions

• This invention relates to a hydrosilation process involving the reaction of a compound containing silicon-bonded hydrogen with a compound containing aliphatic unsaturation in the presence of ultraviolet or visible radiation, and to compositions that are useful in said process.
• the invention further relates to polysiloxane compositions, prepared by said process, which compositions are useful for preparing dental impressions, adhesives, release liners, and caulking materials.
• platinum complexes for accelerating the aforementioned thermally-activated addition reaction include: a platinacyclobutane complex having the formula (PtCl 2 -C 3 H 6 ) 2 (U.S. Patent No.
• chloroplatinic acid with an alcohol, ether, aldehyde, or mixtures thereof U.S. Patent No. 3,220,972, Lamoreaux
• a platinum compound selected from trimethylplatinum iodide and hexamethyldiplatinum U.S. Patent No.
• X is a halogen or alkyl radical (U.S. Patent No. 4,276,252, Kreis et al);
• platinum alkyne complexes U.S. Patent No. 4,603,215, Chandra et al.
• platinum alkenylcyclohexene complexes U.S. Patent No. 4,699,813, Cavezzan
• a colloidal hydrosilation catalyst provided by the reaction between a silicon hydride or a siloxane hydride and a platinum (0) or platinum (II) complex
• platinum complexes and many others are useful as catalysts in processes for
• Platinum complexes that can be used to initiate ultraviolet radiation-activated hydrosilation reactions have been disclosed, e.g., platinum azo complexes (U.S. Patent No. 4,670,531,
• compositions that are curable by ultraviolet radiation include those described in U.S. Patent Nos. 4,640,939 and 4,712,092 and in European Patent Application No. 0238033.
• this invention provides an improved process for the actinic radiation-activated addition reaction of a compound containing
• hydrosilation silicon-bonded hydrogen with a compound containing aliphatic unsaturation, said addition being referred to as hydrosilation, the improvement comprising using, as a platinum hydrosilation catalyst, an
• the process comprises exposing to actinic radiation, i.e., radiation having a wavelength of about 200 nm to about 800 nm, a composition capable of undergoing hydrosilation comprising:
• radiation having a wavelength of about 200 nm to about 800 nm, and having a triplet energy of at least 31 Kcal/mole.
• the invention further involves novel compositions, capable of undergoing hydrosilation, containing both the aforementioned platinum complex and the aforementioned sensitizer.
• An important application of the process and compositions of the invention is as a visible light curable impression material for dental applications.
• reaction composition will not react prematurely or readily in the absence of actinic radiation
• the term "compound”, unless indicated otherwise, is a chemical substance which has a particular molecular identity or is made of a mixture of such substances, e.g., polymeric substances.
• hydrosilation means the addition of organosilicon compounds containing silicon-bonded hydrogen to a compound containing an aliphatic multiple bond, and in the hydrosilation process described in this application, it refers to those processes in which platinum-containing catalysts are used to effect the addition of an organosilicon compound having a
• the platinum complex is an ( ⁇ - ⁇ iolefin)( ⁇ -aryl)platinum complex described in U.S. Patent No. 4,530,879,
• R 1 represents an alkadiene that is ⁇ -bonded to platinum, the alkadiene being a straight or branched chain group and preferably
• alkadiene preferably containing 6 to 12 carbon atoms, the alkadiene further being either
• R 2 and R 3 represent aryl radicals that are
• ⁇ -bonded to platinum are independently selected from monocyclic and polycyclic aryl radicals preferably containing 6 to 18 carbon atoms, said aryl radicals being either unsubstituted or substituted with one or more groups that are inert in a hydrosilation reaction;
• R 4 and R 5 each independently represents
• a represents zero or one, being zero only when both R 4 and R 5 are said alkenyl radicals and being one when either R 4 or R 5 is not said alkenyl radical.
• Sensitizers suitable for this invention are those compounds capable of absorbing actinic radiation within the ultraviolet and visible regions of the
• electromagnetic spectrum i.e., about 200 nm to about 800 nm, and capable of transferring energy to the
• platinum complex It has been discovered that they must have a triplet energy level of at least 31 Kcal/mole, and must not inhibit the hydrosilation reaction.
• Sensitizers are preferably selected from two classes of compounds: 1) polycyclic aromatic compounds, and 2) aromatic compounds containing a ketone chromophore.
• the sensitizer compounds can be substituted with any
• substituents examples include alkyl, alkoxy, aryl, aryloxy, aralkyl, alkaryl, halogen, etc.
• sensitizers suitable for the invention include
• anthracene 9-vinylanthracene, 9,10-dimethylanthracene, 9,10-dichloroanthracene, 9,10-dibromoanthracene,
• unsaturated compounds contain elements other than carbon and hydrogen, it is preferred that these elements be either oxygen, nitrogen, silicon, a halogen, or a
• the aliphatically unsaturated compound can contain one or more carbon-to-carbon
• aliphatically unsaturated hydrocarbons which can be employed include mono-olefins, for example, ethylene, propylene, and 2-pentene, diolefins, for example, divinylbenzene, butadiene, and 1,5-hexadiene,
• cycloolefins for example, cyclohexene and cycloheptene
• monoalkynes for example, acetylene, propyne, and l-buten-3-yne.
• the aliphatically unsaturated compounds can have up to 20 to 30 carbon atoms, or more.
• Oxygen-containing aliphatically unsaturated compounds can also be used, especially where the
• unsaturation is ethylenic, such as methyl vinyl ether, divinyl ether, phenyl vinyl ether, monoallyl ether of ethylene glycol, allyl aldehyde, methyl vinyl ketone, phenyl vinyl ketone, acrylic acid, methacrylic acid, methyl acrylate, allyl acrylate, methyl methacrylate, allyl methacrylate, vinylacetic acid, vinyl acetate, and linolenic acid.
• Heterocyclic compounds containing aliphatic unsaturation in the ring such as
• dihydrofuran, and dihydropyran are also suitable for the present invention.
• Halogenated derivatives of the previously mentioned aliphatically unsaturated compounds can be employed, including acyl chlorides as well as compounds containing a halogen substituent on a carbon atom other than a carbonyl carbon atom.
• halogen-containing compounds include, for example, vinyl chloride, and the vinyl chlorophenyl esters.
• Unsaturated compounds containing nitrogen substituents such as acrylonitrile, N-vinylpyrrolidone alkyl cyanide, nitroethylene, etc., are also useful in the practice of the present invention.
• unsaturated compounds useful in the practice of the present invention include polymers containing aliphatic unsaturation, such as the polyester resins prepared from polybasic saturated or unsaturated acids with polyhydric unsaturated alcohols, and the polyester resins prepared by reacting unsaturated polybasic acids with saturated polyhydric alcohols.
• a particularly useful type of unsaturated compound which can be employed in the practice of the present invention is that containing silicon, such as those compounds commonly referred to as organosilicon monomers or polymers. These unsaturated organosilicon compounds have at least one aliphatically unsaturated organic radical attached to silicon per molecule.
• the aliphatically unsaturated organosilicon compounds include silanes, polysilanes, siloxanes, silazanes, as well as monomeric or polymeric materials containing silicon atoms joined together by methylene or
• aliphatically unsaturated organosilicon compounds useful in the present invention are the monomeric silanes having the empirical formula:
• R 6 represents a monovalent aliphatic unsaturated hydrocarbyl group
• R 7 represents a monovalent saturated hydrocarbyl group
• X represents a hydrolyzable group
• b represents an integer from 1 to 4, inclusive, c represents zero or an integer from 1 to 3, inclusive, the
• d represents an integer from 3 to 18, inclusive
• e represents a number having a value of 0.0001 to 1, inclusive
• f represents zero or a number such that the sum of e and f is equal to 1 to 2, inclusive.
• Monovalent aliphatic unsaturated hydrocarbyl groups represented by R 6 include alkenyl, for example, vinyl, propenyl, isopropenyl, 3-butenyl, and 5-hexenyl.
• Groups represented by R 7 include, for example, alkyl groups, such as methyl, ethyl, and pentyl; cycloalkyl groups, such as cyclopentyl and cyclohexyl; aryl groups such as phenyl and tolyl; aralkyl groups, such as benzyl and phenylethyl; and halogenated hydrocarbyl groups, such as haloalkyl, e.g., chloromethyl, trichloromethyl, and 3,3,3-trifluoropropyl, and haloaryl, e.g.,
• Hydrolyzable groups represented by X include, for example, halogen groups such as chloro , bromo , and iodo , alkoxy groups such as methoxy , ethoxy, and phenoxy, and acyloxy groups such as acetoxy,
• a hydrolyzable group is one which undergoes a displacement reaction with water.
• the compound containing aliphatic unsaturation is an aliphatically unsaturated polyorgano- siloxane represented by the general formula:
• each R 8 can be the same or different and represents a non-halogenated or halogenated
• ethylenically- unsaturated group having from 2 to 18 carbon atoms such as vinyl, propenyl, and chlorovinyl
• a non-halogenated or halogenated alkyl group having from 1 to 18 carbon atoms such as methyl, ethyl, propyl, hexyl, octyl, dodecyl, octadecyl, trichloromethyl, and 3,3,3-trifluoropropyl
• h represents a number having a value from 1 to
• g 0, 1, 2, or 3.
• the reactant containing the silicon-hydrogen linkage can be a polymeric compound or a compound that is not polymeric.
• These compounds are well-known in the art and are disclosed in the patents which describe the aliphatically unsaturated reactant, i.e., Ashby, U.S. Patent No. 3,159,662; Lamoreaux, U.S. Patent No.
• the reactant containing the silicon-hydrogen linkage should contain at least one silicon-bonded hydrogen atom per molecule, with no more than three hydrogen atoms
• silicon-bonded hydrogen atom which can be used in the invention are organosilanes having the empirical formula
• R 9 represents an organic group, preferably
• j represents the integer 1, 2, or 3
• k represents zero or an integer of 1 to 3
• X, d, e and f are as defined above for formulas II, III, and IV.
• R 9 examples include, for example, alkyl groups having 1 to 18 carbon atoms, e.g., methyl, ethyl, propyl, octyl, and octadecyl, cycloalkyl groups having 5 to 7 ring carbon atoms, e.g., cyclohexyl and cycloheptyl, aryl groups having 6 to 18 carbon atoms, e.g., phenyl, naphthyl, tolyl, xylyl, and combinations of alkyl and aryl groups, e.g., aralkyl groups, such as, benzyl and phenylethyl, and
• halo-substituted groups thereof e.g., chloromethyl, chlorophenyl, and dibromophenyl.
• the R 9 group is methyl or both methyl and phenyl.
• the R 9 group can also be an unsaturated aliphatic group having 1 to 20 carbon atoms, such as alkenyl or cycloalkenyl, e.g., vinyl, allyl and cyclohexenyl.
• the silicon compound containing silicon-hydrogen linkages can be reacted with itself to form a polymer.
• a preferred compound having silicon-bonded hydrogen useful in this invention is a
• each R 10 can be the same or different and
• n represents hydrogen, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a phenyl group, at least one but not more than one-half of all the R 10 groups in the siloxane being hydrogen, m represents 0, 1, 2, or 3, and
• n represents a number having an average value from 1 to about 3,000.
• the hydrosilation composition useful in the synthesis of low molecular weight compounds by the process of the invention can be prepared by mixing about 0.1 to about 10.0 equivalent weights of the compound having silicon-bonded hydrogen with one equivalent weight of the compound having aliphatic unsaturation and then adding an amount of platinum complex catalyst sufficient to catalyze the reaction and an amount of sensitizer sufficient to sensitize the platinum complex upon exposure to actinic radiation having a wavelength from about 200 nm to about 800 nm.
• the amount of the catalyst can range from about 5 to about 1,000 parts by weight, preferably from about 50 to about 500 parts by weight, per 1,000,000 parts by weight of the total composition.
• the amount of sensitizer can range from about 50 to about 50,000 parts by weight, preferably from about 500 to about 5,000 parts by weight, per 1,000,000 parts by weight of total composition.
• reactants and catalyst can be introduced into a vessel equipped for stirring, where the mixture is stirred until it is homogenous. If either of the reactants is a solid or is extremely viscous, a solvent can be
• Suitable solvents include aromatic hydrocarbons, such as xylene and toluene, aliphatic hydrocarbons, such as hexane and mineral spirits, and halogenated hydrocarbons, such as chlorobenzene and trichloroethane. It is desirable that the solvent be transmissive to actinic radiation. From about 0.1 to about 10 parts of solvent per part by weight of the combined reactants may be used. The resulting reaction product will generally be sufficiently pure for its intended use. However, it may be desirable to remove the solvent if one has been employed.
• hydrosilation compositions useful in the preparation of higher molecular weight cured siloxane polymers, by the process of this invention can be prepared by mixing an aliphatically unsaturated
• reaction mixture can be mixed, as by stirring, blending, or tumbling, until it is homogenous.
• the thoroughly mixed composition can then be applied to a substrate by any suitable means, such as by spraying, dipping, knife coating, curtain coating, roll coating, or the like, and the coating cured by using conventional techniques for providing actinic radiation. It is preferred that curing be conducted by exposing the coated substrate to radiation having a wavelength of about 200 nm to about 800 nm. Depending on the
• any radiation source emitting radiation above about 200 nm can be used.
• suitable radiation sources include tungsten halogen lamps, xenon arc lamps, mercury arc lamps, incandescent lamps, and fluorescent lamps.
• Particularly preferred sources of visible radiation are tungsten halogen, xenon arc, and mercury arc lamps.
• additives conventionally included in hydrosilation compositions can be included in the curable compositions, depending on the intended purpose of the composition.
• Fillers and/or pigments such as chopped fibers, crushed polymers, talc, clay, titanium dioxide, and fumed silica can be added.
• Soluble dyes, oxidation inhibitors, and/or any material that does not interfere with the catalytic activity of the platinum complex and does not absorb actinic radiation at the absorption wavelength of the sensitizer can be added to the composition.
• the shelf life of the curable compositions containing the catalyst and sensitizer can be extended by the addition of a conventional catalyst inhibitor.
• the amount of catalyst inhibitor can vary from about 1 to about 10 times, or more, the amount of platinum complex, depending on the activity of the particular complex or complex-accelerator used and the shelf life desired for the composition. Greater amounts of inhibitor should be used with the more active complexes, with lesser amounts being used for the less active complexes.
• Hydrosilation inhibitors are well known in the art and include such compounds as acetylenic
• any solid substrate for a variety of purposes.
• substrates include paper, cardboard, wood, cork,
• plastic such as polyester, nylon, polycarbonate, etc.
• woven and nonwoven fabric such as cotton, polyester, nylon, etc., metal, glass, and ceramic.
• epoxy-functional siloxanes as taught in U.S. Patent No. 4,243,718 (Murai, et al) are useful for priming the surface of plastic films such as polyester and
• compositions of this invention can be applied and cured in relatively thick sections, such as an impression material for dental applications or a
• compositions of this invention were evaluated for cure speed in the following manner. Molds made from a 1.5 mm thick "Teflon" sheet with a 6 mm diameter hole through the sheet were clamped to clean glass slides so that the central axis of the hole in the mold was normal to the glass slide. The hole was filled with a sample of the composition being evaluated.
• a "Visilux” 2 dental curing light (available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota) with a light output in the visible region of the spectrum between 400 and 500 nm was clamped to a ring stand and positioned such that the cylindrical tip of the light source was 5.0 mm above the top of the "Teflon” mold. The center of the 6 mm diameter sample was directly beneath the light tip.
• a stock composition was prepared by mixing in a glass container 97.5 parts by weight of vinyl
• photosensitizers are capable of increasing the cure speed of this silicone formulation
• Example 2 To 10.0 g aliquots of the composition of Example 1 were added the photohydrosilation catalyst (COD)Pt(p-C 6 H 4 OCH 3 ) 2 at a concentration of 200 ppm Pt and varying amounts of the photosensitizer
• 2-chlorothioxanthone under a "Black Light” source ( ⁇ 400 nm ) up to a level of at least 2 , 000 ppm and under a "Visilux” 2 source (400-500 nm) up to a level of about 1,000 ppm.
• compositions of this invention were added 15.8 mg of (COD)Pt(p-C 6 H 4 OCH 3 ) 2 (200 ppm Pt) and 15 mg of 2-chlorothioxanthone (500 ppm).
• the composition was coated on super calendered Kraft paper at a coating weight of 1 to 2 g/m 2 and cured by irradiation under an atmosphere of nitrogen in a PPG processor that advanced the sample at a rate of 50 cm/sec under two medium pressure mercury lamps emitting 120 watts of radiation per centimeter of lamp length and subsequent heating in a circulating air oven at 100°C for 2 minutes.
• the release value of the cured silicone coating was determined by the following procedure: A heptane-isopropyl alcohol solution of pressure-sensitive adhesive comprising isooctyl acrylate (95.5% by
• silicone-coated substrate at an angle of 180° and a pulling speed of 230 cm/min.
• the readhesion value of the pressure-sensitive tapes was determined by the following procedure: The pressure-sensitive tapes, as removed from the silicone coated surface, were applied to the surface of a clean glass plate. An average value of 1,400 g per 2.5 cm of width was measured to be the force required to pull the tape from the glass surface at an angle of 180° and a pulling speed of 230 cm/min. A control readhesion value was obtained for the pressure-sensitive tape by applying the tape, which had not been placed in contact with a silicone-coated surface, to a clean glass plate and measuring the force required to remove the tape from the plate. The control readhesion value was 1,500 g per 2.5 cm of width.
• This example illustrates the preparation of a silicone-based pressure-sensitive adhesive tape from a composition of this invention.
• a mixture of the silicone-based pressure-sensitive adhesive tape from a composition of this invention.
• the mixture was stripped of volatile material by heating at 65°C under less than 0.5 mm of Hg pressure on a rotary evaporator. To the resulting viscous mixture were added 0.80 g of
• 2-chlorothioxanthone (1,000 ppm).
• the composition was knife coated at a thickness of 0.05 mm on a 0.05 mm thick polyethylene terephthalate film, and the coating was cured by irradiation under an atmosphere of nitrogen in a PPG processor that advanced the sample at a rate of 50 cm/sec under two medium pressure mercury lamps emitting 120 watts of radiation per centimeter of lamp length and subsequent heating in a circulating air oven at 100oC for two minutes.
• Adhesion was determined essentially according to the procedure described in ASTM D-330 (1983). Strips of the tape 2.54 cm wide and approximately 25 cm long were adhered to a glass surface using a 2.04 kg rolled weight. An average value of 1,600 g per 2.5 cm of width was measured to be the force required to pull the adhesive tape away from the glass surface at an angle of 180° and a pulling speed of 230 cm/min.
• Shear strength was determined essentially according to the procedure described in ASTM D-3654 (1982). Specimens 1.27 cm wide and approximately 8 cm long were adhered to a bright annealed steel surface with an overlap area of 1.27 cm by 1.27 cm. The samples were suspended vertically and maintained at a
• the tack of the adhesive tape was measured qualitatively by touching the cured adhesive with a finger. Tack was judged to be moderate.
• composition of this invention illustrates the preparation of a conformal coating for electronic components using a composition of this invention.
• a composition consisting of the following ingredients in the amounts indicated was prepared:
• the composition was applied to an integrated circuit board measuring 2 inches by 2 inches in
• the coating was irradiated with a "Visilux" 2 light source for approximately 4 minutes to provide a tough, elastomeric, transparent coating that adhered well to the circuit board.
• This example illustrates preparation of a dental impression by means of a visible-light curable wash material and a chemically curable tray material.
• a polyvinylsiloxane formulation curable by visible light was prepared by mixing the following ingredients in the amounts indicated:
• impression material (Express Medium Viscosity Wash, Minnesota Mining and Manufacturing Company, St. Paul, Minnesota) was applied by syringe directly over the several teeth both adjacent to and including those previously irradiated with light. The material was allowed to set for about five minutes. The bulk

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  • 1991-11-12 KR KR1019930701779A patent/KR930703402A/ko not_active Application Discontinuation
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