Patents Represented by Attorney C. Alexander
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Patent number: 4397142Abstract: Coded threads and sheet material for making such threads useful in counterfeit-inhibiting garments. The sheet material comprises transparent microspheres, a specularly reflective layer underlying the microspheres, and a polymeric layer underlying the specularly reflective layer and containing particulate matter which may be varied from sheet material to sheet material to encode information and allow identification of the sheet material. The sheet material is split in narrow widths and incorporated into threads.Type: GrantFiled: December 7, 1981Date of Patent: August 9, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventor: Wallace K. Bingham
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Patent number: 4393901Abstract: Pipe adapted to be installed underwater at increased ocean depths by practical pipe-laying procedures comprises a porous cement shell filled with hollow spheres that are slowly permeable to water under pressure. The cement shell is filled with a sufficient volume of the hollow spheres to make the pipe only slightly heavier than sea water, providing a reduced weight that overcomes previous difficulties in laying pipe at great depths. Over a period of time after the pipe has been installed underwater, the hollow spheres gradually fill with water and make the pipe rest stably on the ocean bottom. The preferred spheres comprise porous core spheres coated with thin coatings that partially seal the spheres to the needed degree of permeability.Type: GrantFiled: July 19, 1982Date of Patent: July 19, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventor: Warren R. Beck
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Patent number: 4391646Abstract: Glass bubbles of increased collapse strength are prepared. The bubbles have an average particle density of 0.4 or more and are made of glass that consists essentially of SiO.sub.2 (60-90 weight-percent), alkali metal oxide (2-20 weight-percent), B.sub.2 O.sub.3 (1-30 weight-percent), sulfur (0.005 to 0.5 weight-percent), and other conventional glass-forming ingredients.Type: GrantFiled: February 25, 1982Date of Patent: July 5, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventor: Peter A. Howell
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Patent number: 4388359Abstract: Pavement-marking sheet material having protuberances on its upper surface which carry partially exposed microspheres by which the protuberances are made retroreflective and which are separated by recessed areas in which microspheres are fully embedded and not exposed, so as to improve the daytime appearance of the sheet material.Type: GrantFiled: April 23, 1982Date of Patent: June 14, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventors: John L. Ethen, Timothy D. Bredahl
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Patent number: 4377988Abstract: Reflective sheeting useful for application to a pesticide-impregnated animal collar, and animal collars made from the sheeting. The sheeting generally comprises a monolayer of transparent microspheres; specularly reflective material underlying the microspheres; a binder layer of polymeric binder material in which the microspheres are partially embedded; a carrier sheet stretchable about 10 percent or more before rupture, in which the portions of the microspheres protruding from the binder layer are embedded; a barrier layer underlying the binder layer, which sorbs plasticizers more slowly than the binder layer sorbs the plasticizers; and a layer of adhesive underlying the barrier layer.Type: GrantFiled: September 24, 1981Date of Patent: March 29, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventors: Chi F. Tung, James C. Coderre, Chester A. Bacon, Jr.
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Patent number: 4372997Abstract: Fire- and heat-resistant sheet material comprises fibrous webs adhered together with asphalt which is filled with inorganic particles, intumescable granules, and a catalyst which catalyzes charring of the asphalt.Type: GrantFiled: April 9, 1982Date of Patent: February 8, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventors: Gary D. Fritze, Joseph Graham
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Patent number: 4367920Abstract: New methods for making "embedded-lens" retroreflective sheeting, and new forms of such sheeting, are provided. The new sheetings are retroreflective through an increased angular range, and also provide brighter overall retroreflectivity and other advantageous properties.Type: GrantFiled: June 19, 1981Date of Patent: January 11, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventors: Chi F. Tung, James C. Coderre
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Patent number: 4367919Abstract: Glass microspheres and other glass elements based on B.sub.2 O.sub.3, BaO, SiO.sub.2 and TiO.sub.2 have an improved combination of crushing strength, index of refraction, and, especially in some formulations, chemical resistance. The microspheres are especially adapted for use as retroreflective elements in pavement markings.Type: GrantFiled: March 19, 1981Date of Patent: January 11, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventors: Chi F. Tung, Benjamin T. Fellows
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Patent number: 4349598Abstract: Retroreflective film, sheeting or the like having an array of light-reflecting right triangle prisms between a transparent surface layer and a backing layer. The opposing triangular end faces of adjacent prisms are spaced apart to provide internal reflection therefrom. The retroreflective material provides efficient retroreflection at angles of incidence of about 30.degree.-85.degree. and therefore is effective where light is directed in a path nearly parallel to a reflective surface, such as highway lane dividers or guardrail markers placed parallel to a highway. Retroreflective material on such markers becomes visible to an observer while yet remote from the markers.Type: GrantFiled: December 1, 1976Date of Patent: September 14, 1982Assignee: Minnesota Mining and Manufacturing CompanyInventor: Michael L. White
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Patent number: 4348312Abstract: Compositions comprising copolymers of methyl methacrylate and ethyl acrylate and of vinylidene fluoride and hexafluoropropylene may be blended to form transparent compositions of low refractive index, making them useful in retroreflective products as a layer in which glass microspheres are embedded.Type: GrantFiled: March 11, 1981Date of Patent: September 7, 1982Assignee: Minnesota Mining and Manufacturing CompanyInventor: Chi F. Tung
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Patent number: 4323633Abstract: It is desirable to protect color photographic dye images from ultraviolet radiation which tends to cause dyes to fade.It has been the practice in the art to add materials into or above the silver halide emulsions which will absorb ultraviolet radiation but allow transmission of visible radiation.One of the best classes of compounds are the 2-(2'-hydroxyphenyl)-benzotriazoles. These materials absorb ultraviolet radiation well, but tend to have poor solubility, crystallize out of the coating solution and emulsion, and diffuse through the photographic element.A novel class of substituted 2-(2'-hydroxyphenyl)-benzotriazoles has been found to reduce many of these problems.Type: GrantFiled: November 13, 1980Date of Patent: April 6, 1982Assignee: Minnesota Mining and Manufacturing CompanyInventor: Paolo Beretta
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Patent number: 4323591Abstract: Polyacrylate materials having certain heterocyclic nuclei within the structure have been found to be readily and polymerizable by irradiation in air. Typically, polyacrylate materials are highly sensitive to the presence of oxygen and do not polymerize fully unless special precautions or conditions are undertaken.Type: GrantFiled: January 29, 1981Date of Patent: April 6, 1982Assignee: Minnesota Mining and Manufacturing CompanyInventors: Larry A. Wendling, John B. Covington
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Patent number: 4312676Abstract: A liquid coating composition that is useful to form retro-reflective marks that actuate photoscanner sensing devices and that comprises a liquid vehicle and retro-reflective elements uniformly dispersed in the vehicle. The vehicle includes a high proportion of volatile solvent and a gel agent that gels the vehicle so that the retro-reflective elements are suspended in the vehicle. The gel agent comprises at least a large proportion of the non-volatile portion of the vehicle.Type: GrantFiled: August 26, 1977Date of Patent: January 26, 1982Assignee: Minnesota Mining & Manufacturing CompanyInventors: John M. Hogseth, Melvin L. Johnson
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Patent number: 4288355Abstract: A surgical cement comprised of a concentrated non-gelling aqueous solution of a polycarboxylic acid and an aqueous suspension of metal oxide powder which when mixed together form a plastic mass which is formable into the desired shape before it hardens. The surgical cement has particular utility for dental applications.Type: GrantFiled: May 22, 1978Date of Patent: September 8, 1981Assignee: Minnesota Mining and Manufacturing CompanyInventors: Harvey L. Anderson, Ronald M. Randklev
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Patent number: 4256828Abstract: Photocopolymerizable compositions are described which contain epoxides, organic material with hydroxyl functionality, and a photosensitive aromatic sulfonium or iodonium salt of a halogen-containing complex ion. Coated substrates are also described.Type: GrantFiled: September 2, 1975Date of Patent: March 17, 1981Assignee: Minnesota Mining and Manufacturing CompanyInventor: George H. Smith
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Patent number: 4256694Abstract: Colorimetric indicator material comprising alumina impregnated with permanganate ion and silver ion which changes color from purple to brown in the presence of carbon monoxide is disclosed. A personal monitor containing permanganate ion and silver ion impregnated alumina which changes color completely when the carbon monoxide exposure over a given period of time exceeds a predetermined concentration is disclosed.Type: GrantFiled: June 5, 1978Date of Patent: March 17, 1981Assignee: Minnesota Mining and Manufacturing CompanyInventors: Jerome W. McAllister, Gunter A. Kohler, Virtudes R. Lund
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Patent number: 4231886Abstract: Compositions are provided comprising complex salts dissolved in liquid organic esters in amounts of at least 10% by weight. The compositions provide a concentrated liquid form of complex salt for use as photoinitiator in polymerization reactions.Type: GrantFiled: January 29, 1979Date of Patent: November 4, 1980Assignee: Minnesota Mining and Manufacturing CompanyInventor: Robert C. Carlson
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Patent number: 4231951Abstract: A triarylsulfonium complex salt is described which has particular utility as a photoinitiator for the polymerization of epoxide monomers in thick films or coatings. Photopolymerizable compositions are also described.Type: GrantFiled: June 25, 1979Date of Patent: November 4, 1980Assignee: Minnesota Mining and Manufacturing CompanyInventors: George H. Smith, Peter M. Olofson
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Patent number: RE31087Abstract: A method for separating water-immiscible oils and oil-like substances from mixtures including said oils in an aqueous medium which comprises contacting the mixture with an oleophilic fibrous web comprising large numbers of interconnected, interstitial spaces for reception and retention of the oil to the exclusion of water.Type: GrantFiled: April 16, 1981Date of Patent: November 23, 1982Assignee: Minnesota Mining and Manufacturing CompanyInventor: William E. Sohl
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Patent number: RE31285Abstract: A method for forming a filter of electrically charged electret fiber material, consisting of a high molecular weight, nonpolar polymeric substance, comprising drawing, charging, and fibrillating a foil of said high molecular weight substance. The fibrillated foil is wound and then crimping is effected.Type: GrantFiled: December 7, 1981Date of Patent: June 21, 1983Assignee: Minnesota Mining and Manufacturing CompanyInventors: Jan van Turnhout, Johannes C. Rieke