Patents Represented by Attorney Douglas B. Little
  • Patent number: 5486271
    Abstract: A process for preparing perfluoroalkanesulfonyl fluorides, e.g., perfluoromethanesulfonyl fluoride, is described which comprises electrochemically fluorinating in the presence of anhydrous hydrogen fluoride mono-, di- or tri- alkylsulfonyl alkyl esters or amides, or mono-, bis- or tris- alkylsulfonyl alkanes or disulfones. The process can be used to prepare perfluoroalkanesulfonyl fluorides in good yield and can be both more electrically-efficient and more fluorine-efficient than the conventional preparative method involving the electrochemical fluorination of hydrocarbon alkanesulfonyl halides.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: January 23, 1996
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: John C. Hansen, Herward A. Vogel
  • Patent number: 5378575
    Abstract: A weather resistant sign and a method of printing a sign including the steps of providing a sign component and an image definition, applying dry toner powder to surface portions corresponding to the image definition, and fusing the applied toner. Preferably, the fused toner is protected from weather by a transparent protective layer. A toner composition and a computer program for printing are also disclosed.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: January 3, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: J. Sundar Rajan, Vincent J. Mako
  • Patent number: 5262225
    Abstract: A curable polymer composition for use in providing a dimensionally stable coating comprises a semi-interpenetrating polymer network. The semi-interpenetrating polymer network includes a reactive polymer component, cross-linking agent, and non-reactive polymer component. The non-reactive polymer component has a molecular weight of about 7,000-30,000, and preferably about 15,000. In preferred embodiments, the reactive polymer has a molecular weight of about 30,000-200,000, and preferably about 40,000-60,000. Spacecoat compositions made with formulations described, exhibit good long-term stability, and resistance to failure upon embossing of a substrate to which the retroreflective sheeting is applied.
    Type: Grant
    Filed: October 19, 1992
    Date of Patent: November 16, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bruce B. Wilson, Raymond E. Grunzinger
  • Patent number: 5256721
    Abstract: A curable polymer composition for use in providing a dimensionally stable coating comprises a semi-interpenetrating polymer network. The semi-interpenetrating polymer network includes a reactive polymer component, cross-linking agent, and non-reactive polymer component. The non-reactive polymer component has a molecular weight of about 7,000-30,000, and preferably about 15,000. In preferred embodiments, the reactive polymer has a molecular weight of about 30,000-200,000, and preferably about 40,000-60,000. Spacecoat compositions made with formulations described, exhibit good long-term stability, and resistance to failure upon embossing of a substrate to which the retroreflective sheeting is applied.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: October 26, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bruce B. Wilson, Raymond E. Grunzinger
  • Patent number: 5232791
    Abstract: The present invention provides a magnetic recording medium that includes a polymeric flexible substrate and a magnetic layer coating thereon, with a binderless carbon rich layer adhered to the magnetic layer.The present invention also provides a process for the plasma deposition of the carbon rich coating onto a magnetic medium comprising the steps of:a. providing a magnetic medium in a vacuum chamber;b. generating carbon rich plasma in the vacuum chamber by injecting a plasma gas suitable to provide a carbon rich coating into an elongated hollow cathode; and providing a sufficient voltage to create and maintain plasma; and maintaining a vacuum in the vacuum chamber sufficient for the plasma; andc. exposing the magnetic medium to the plasma while the magnetic medium is influenced by a radio frequency bias electrode to accelerate the plasma towards the magnetic medium and deposit the carbon rich coating on the magnetic medium.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: August 3, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Gunter A. Kohler, Richard W. Duerst, Daniel P. Stubbs
  • Patent number: 5196474
    Abstract: A curable polymer composition for use in providing a dimensionally stable coating comprises a semi-interpenetrating polymer network. The semi-interpenetrating polymer network includes a reactive polymer component, cross-linking agent, and non-reactive polymer component. The non-reactive polymer component has a molecular weight of about 7,000-30,000, and preferably about 15,000. In preferred embodiments, the reactive polymer has a molecular weight of about 30,000-200,000, and preferably about 40,000-60,000. Spacecoat compositions made with formulations described, exhibit good long-term stability, and resistance to failure upon embossing of a substrate to which the retroreflective sheeting is applied.
    Type: Grant
    Filed: January 11, 1991
    Date of Patent: March 23, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bruce B. Wilson, Raymond E. Grunzinger
  • Patent number: 5194113
    Abstract: Thermoplastic based pavement marking sheets are disclosed. The marking sheets employ a conformant composite material including: polyolefin and a nonreinforcing mineral particulate; and/or a thermoplastic upper surface. Preferably, the sheet's thermoplastic upper surface is embedded with reflective elements and/or skid-resistant particles. A solventless process of embedding particles in thermoplastic pavement marking sheets is disclosed. Processes for preparing marking sheets are also disclosed. Conformant pavement marking sheets which may be applied in cooler conditions are also disclosed.
    Type: Grant
    Filed: February 3, 1992
    Date of Patent: March 16, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: James E. Lasch, Gregory F. Jacobs, Terry R. Bailey, Louis C. Belisle, Roger R. Kult, Robert A. Haenggi, Michael P. Daniels
  • Patent number: 5138488
    Abstract: The present invention provides an improved cube-corner retroreflective article that exhibits a wide range of retroreflective angularity in multiple viewing planes. The present invention provides cube-corner retroreflective elements having a decreased size, as measured by the height of the cube corner, thereby decreasing the amount of canting required to achieve a given angularity. Alternatively, angularity can be enhanced by leaving the degree of canting constant and decreasing the size of the cube corner.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: August 11, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Theodore J. Szczech
  • Patent number: 5110667
    Abstract: Polymer blend useful in making release liners, especially for reflective sheeting, comprises:A. a matrix polymer (e.g., a polyolefin);B. a filler such as CaCO.sub.3 ;C. a fluorocarbon, such as a 2-oxazolidinone compound.Typical proportions are: polypropylene 54.5%, CaCO.sub.3 45%, and fluorochemical oxazolidinone 0.5%.Liners made of this composition can be used both in the process of manufacturing reflective sheeting and as release liners on finished product, thus combining process and product liner into one. They can also be used as a slip sheet in bonding reflective sheeting to sign blanks or substrates.
    Type: Grant
    Filed: March 26, 1990
    Date of Patent: May 5, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Stephen J. Galick, James E. Sax
  • Patent number: 5085918
    Abstract: A weather resistant sign and a method of printing a sign including the steps of providing a sign component and an image definition, applying dry toner powder to surface portions corresponding to the image definition, and fusing the applied toner. Preferably, the fused toner is protected from weather by a transparent protective layer. A toner composition and a computer program for printing are also disclosed.
    Type: Grant
    Filed: May 15, 1990
    Date of Patent: February 4, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: J. Sundar Rajan, Vincent J. Mako
  • Patent number: 5082715
    Abstract: Conformable marking sheet comprising a microporous thermoplastic polymer base sheet having a network of interconnected pores. The marking sheet has a low yield stress, making it conformable to rough surfaces. The pores of the base sheet can be filled with a diluent (wax) or they may have the diluent removed, for example by extraction. The construction may further comprise an adhesive on the bottom and a top marking indicium layer comprising a polymeric binder in which is partially embedded a multiplicity of retroflective lens elements, e.g., transparent microspheres.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: January 21, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: James E. Lasch, James M. Kaczmarczik, James A. Klein
  • Patent number: 5073404
    Abstract: Retroreflective sheeting has been improved by a coating comprising silica and a transparent polymer selected from aliphatic polyurethanes, polyvinyl chloride copolymers having a minor amount of a comonomer containing at least one carboxylic acid or hydroxyl moiety, and acrylic polymers. Silica comprises 10-80 weight percent (10-70% in the case of polyacrylates) of the transparent protective coating. For example, a solution or dispersion of polyurethane is mixed with a silica sol and possibly other ingredients (e.g. wetting agent, UV light absorber and adhesion promoter), and the composition is coated onto the retroreflective sheet and dried. The coated retroreflective sheeting has superior soil and dew repellancy, retaining a higher percentage of original brightness after exposure to dirt and/or dew conditions.
    Type: Grant
    Filed: July 20, 1990
    Date of Patent: December 17, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Tzuli J. Huang
  • Patent number: 5069577
    Abstract: Raised pavement marker useful in geographic areas where snow plows are used and comprising hollow base with an open bottom and dome top, characterized by:A. base cross section being closed curved shape like cylinder;B. dome having:1) outer surface which approximates surface of rotation of a sine wave with highest point in middle of dome;2) dome cross section is thickest near center and thinnest at p eriphery;3) at least 2 ribs projecting from surface, to protect reflector which may be cube corner reflectror affixed to dome;C. material of construction which is an elastomer having T.sub.g no greater than -50.degree. C., preferably polyurethane compound containing a lubricating polymer, such as a silicone.
    Type: Grant
    Filed: October 23, 1990
    Date of Patent: December 3, 1991
    Inventor: Patrick E. Murphy
  • Patent number: 5059061
    Abstract: Method and apparatus are disclosed for automatically applying pavement marking tape to roadway surfaces using a self-propelled vehicle. Tapes can be applied in continuous stripes or intermittent stripes of variable spacing or length while the vehicle is in motion. Methods are also disclosed for changing rolls of tapes while the vehicle is in motion, and thereby reducing stopping times for splicing. The tape application mechanism can be enclosed within the vehicle so that the operator is protected from traffic hazards.
    Type: Grant
    Filed: June 14, 1990
    Date of Patent: October 22, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Heinrich F. Stenemann, Louis F. Keller
  • Patent number: 5051858
    Abstract: Recording disk, such as a data recording disk, having:1. annular main body having datum surface intended to rest on disk drive turntable;2. hub having a center hole;3. magnetic yoke, generally concentric with the main body and hub; said recording disk being characterized by:A. yoke plate adherend on one side of main body, being radially closer to the center hole than datum surface and adjacent the hub;B. axial spacing between yoke plate and hub; andC. axial spacing between datum surface and the side of the yoke plate away from the yoke plate adherend.Design (keeping disk datum and yoke plate adherend on main body rather than on hub) maintains elasticity of the hub (not restricting it like designs in which yoke plate is glued to hub) giving good disk centering onto disk drive spindle. Preferably, hub is made of material having higher elasticity than main body, and both are integral, i.e., injection molded in intimate contact.Stretched surface recording (SSR) disks can be made with this hub design.
    Type: Grant
    Filed: March 16, 1990
    Date of Patent: September 24, 1991
    Assignees: Minnesota Mining and Manufacturing Company, Sony Corporation
    Inventors: Robert S. Jackson, Toshio Aizawa
  • Patent number: 5028305
    Abstract: A method for producing a magneto-optic layer includes depositing amorphous magnetizable film layer on a substrate using a triode sputtering process. The magneto-optic layer includes an alloy of terbium, cobalt, iron, chromium and an oxygen content approximately between 2-6 atom percent midway through the thickness of the layer.
    Type: Grant
    Filed: April 23, 1990
    Date of Patent: July 2, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Richard F. Willson, Vaughn W. Halling
  • Patent number: 5008142
    Abstract: A curable polymer composition for use in providing a dimensionally stable coating comprises a semi-interpenetrating polymer network. The semi-interpenetrating polymer network includes a reactive polymer component, cross-linking agent, and non-reactive polymer component. The non-reactive polymer component has a molecular weight of about 7,000-30,000, and preferably about 15,000. In preferred embodiments, the reactive polymer has a molecular weight of about 30,000-200,000, and preferably about 40,000-60,000. Spacecoat compositions made with formulations described, exhibit good long-term stability, and resistance to failure upon embossing of a substrate to which the retroreflective sheeting is applied.
    Type: Grant
    Filed: September 2, 1988
    Date of Patent: April 16, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bruce B. Wilson, Raymond E. Grunzinger
  • Patent number: 4989948
    Abstract: The invention provides a reflective sheeting material having a structured reflective surface having a linear ray of isosceles prism reflecting elements, each element including a pair of reflective surfaces at an angle of about 120.degree. therebetween. The invention also provides a reflective sheeting material having a structured reflective surface comprising an array of reflecting elements, each comprising a polyhedron having three paralellogram faces. The invention also provides an apparatus such as a light pole for transporting light and reflecting the light in a broad, uniform pattern. The apparatus comprises (a) a columnar light conduit, for transporting light therealong, the conduit having a proximate end and a distal end; (b) a light source provided at the proximate end of the light conduit,and (c) a light distributing reflective member, such as the reflective sheeting material described above, comprising a multiplicity of repeating reflecting elements.
    Type: Grant
    Filed: May 8, 1989
    Date of Patent: February 5, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: John F. Dreyer, Jr.
  • Patent number: 4988541
    Abstract: Process for making retroreflector sheet having protrusions which are retroreflective on selected side surfaces of the protrusions. Continuous web of polymeric base sheet having a front surface with a plurality, of protrusions, each protrusion having a top surface and at least one side surface, is provided. The web is conveyed through a nip in contact with a liquid film of bonding polymer at sufficient pressure to displace the film from the protrusion top surfaces and onto selected side surfaces, depending upon the relative speeds of the web and bonding polymer film. Retroreflective beads are applied to the liquid film which is then solidified (e.g., by temperature change) to hold the beads in place.
    Type: Grant
    Filed: January 2, 1990
    Date of Patent: January 29, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Thomas P. Hedblom
  • Patent number: 4988555
    Abstract: A retroreflector sheet comprising a base sheet and integral protrusions having a top and a side surface. Selected side surfaces are covered with a bead bond layer including partially embedded retroreflector beads. A process for preparing the retroreflector sheet is also disclosed.
    Type: Grant
    Filed: January 2, 1990
    Date of Patent: January 29, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Thomas P. Hedblom