Showing papers by "3M published in 1973"

Poly(perfluoroalkylene oxide) derivatives

Abstract: Polyfunctional poly(perfluoroalkylene oxide) compounds, such as compounds of the formula A--CF.sub.2 O(CF.sub.2 CF.sub.2 O).sub.m (CF.sub.2 O).sub.n CF.sub.2 --A' where A and A' are reactive radicals containing a polymerizable functional group, e.g., hydroxyl, are provided, such compounds being useful as monomers in the preparation of polymeric materials, e.g., polyurethanes, possessing unusual low temperature stability and resistance to solvents.

Intumescent sheet material

Abstract: An intumescent sheet material is provided containing vermiculite or other expandable mica. A process for mounting catalyst supports is described.

Photopolymerizable sheet material with diazo resin layer

Abstract: Light-sensitive sheet material is provided comprising a base sheet bearing a thin coating of a diazo resin over which is provided a photopolymerizable layer Upon exposure of the sheet material to actinic radiation, the image areas of the photopolymerizable layer as well as corresponding areas of diazo resin are insolubilized Preferred sheet material is useful in lithographic printing

Spheroidal composite particle and method of making

Abstract: Composite abrasive granules, in which fine, hard abrasive grains are distributed throughout a relatively softer metal oxide matrix, can be substituted for conventional abrasive grains. In a preferred method of manufacture, the abrasive grains are dispersed in a metal oxide gel, the gel dehydrated to leave spheroidal composite granules, and the granules heated to drive off the remaining water. The temperature of heating is low enough that temperature-unstable abrasive grains, like diamonds and cubic boron nitride, can be used.

Photosensitive elements containing chromophore-substituted vinyl-halomethyl-s-triazines

Abstract: Chromophore-substituted vinyl-halomethyl-s-triazine compounds are provided capable of free-radical generation upon excitation with radiation having a wavelength of from about 330 to about 700 millimicrons.

Shaped and fired articles of tio2

Abstract: Solid, shaped and fired refractory articles, such as fibers and microspheres, of titanium dioxide are made by shaping, gelling, and firing titania sols. Said fibers can be made by extruding in air a viscous aqueous titania sol, and heating and firing the resulting green fiber to remove water, decompose and volatilize undesired constituents, and form a refractory fiber of polycrystalline titanium dioxide, which is useful, for example, to form refractory fabrics or as reinforcement for composites. Said microspheres can be made by dispersing droplets of an aqueous titania sol in an organic dehydrating liquid, separating the resulting green microspheres from the dehydrating liquid, and heating and firing the green microspheres to form solid refractory microspheres of polycrystalline titanium dioxide, which are useful, for example, in reflective signs or traffic marking surfaces. Said fired fibers and microspheres are preferably transparent to visible light with the titanium dioxide content thereof in its anatase form.

Selected time interval indicating device

Abstract: Indicating device suitable for visibly measuring parameters such as time, temperature, and time-temperature relationships. The device includes a porous fluid carrying pad, a wick material for said fluid, and an indicator means whereby the progress of fluid along the wick material can be visibly indicated and used to measure the passage of time, the exposure to a given minimum temperature, or a time-temperature relationship. The combination is adapted to regulate migration of fluid from the fluid source to the wick material.

Zinc oxide light emitting diode

Abstract: A light emitting diode comprising a single crystal of high efficiency violet fluorescing zinc oxide together with an ohmic cathode and a rectifying anode secured thereto. The diode emits near band-gap radiation at room temperature when energized with low D.C. voltage. The produced light is believed to be associated with radiative recombination of free excitons.

Tamper indicator tape

Abstract: An easy opening, hermetically sealed container with a preformed aperture is covered by a tape closure having on its outer surface an indicator layer which changes color when flexed, thereby indicating whether the closure has been handled or tampered with.

Stratum having release properties and method of making

Abstract: A stratum having accurately predictable and controllable release properties toward normally tacky and pressure-sensitive adhesive sheet materials is prepared by reacting two moieties, one terminated with a plurality of isocyanate groups and the other a liquid hydroxyl- or amine-containing organosilicone. The hydroxyl or amine groups are at least three carbon atoms distant from the nearest silicone atom and constitute no more than about 4% by weight of the organosilicone. Depending upon the release characteristics achieved, the reaction product can function as a shaped article, all or part of a release liner, or as a low-adhesion backsize for pressure-sensitive adhesive tape.

Outerwear fabric treatment

Abstract: Durably launderable and dry-cleanable repellancy to water and oil is conferred on fabrics consisting essentially completely of hydrophobic synthetic fibers by application of a blend of a fluoroaliphatic vinyl polymer and a carbodiimide, preferably comprising fluoroaliphatic groups.

Biaxially oriented polyethylene terephthalate film having a surface suitable for writing thereon

Abstract: An integral heat-set, biaxially oriented composite film comprised of a layer of transparent polyethylene terephthalate having a smooth exposed major surface and a transparent copolyester layer having a matte exposed major surface. The film is dimensionally stable, strong, tough and water resistant, receptive to writing, and transparent when applied to a substrate, permitting visual recognition of indicia therethrough. The film provides a particularly superior backing for an adhesive tape.

Carpet treating and treated carpet

Abstract: A durably soil-resistant carpet is provided which comprises a plurality of organic fibers having thereon a normally solid coating comprising (a) at least one phase of a water-insoluble addition polymer derived from a polymerizable ethylenically unsaturated monomer free of non-vinylic fluorine, the polymer having at least one major transition temperature higher than about 45° C. and a solubility parameter of at least about 8.5, and (b) at least one phase of a water-insoluble fluorinated component containing a fluoroaliphatic radical of at least 3 carbon atoms, the fluorinated component having at least one major transition temperature higher than about 45° C.; and at least one of said phases being a continuous phase. Novel compositions and processes for the treatment of carpets to render them durably soil resistant are also provided.

Removable pressure-sensitive adhesive sheet material

Abstract: A flexible self-sustaining backing is coated with a stable viscous copolymer latex formed from monomers of (1) major amounts of certain alkyl acrylates, (2) minor amounts of certain emulsifier monomers, and (3) if desired, minor amounts of zwitterionic monomers, and the water evaporated from the latex to leave a tacky and pressure-sensitive adhesive. When tape prepared in this way is applied to enameled or lacquered substrates, it can be removed without leaving an adhesive residue, even after extended exposure to heat and light. Other sheet materials (e.g., floor tile, carpeting, label stock, etc.) are similarly removable when provided with this adhesive.

Transfer letter system

Abstract: A composite strip material for forming graphics such as letters, numbers, symbols or pictures. The strip includes an accepting tape comprising a layer of latent adhesive material in face-to-face contact with a layer of microgranules lightly adhered to a donor web. At least one of the layers bears a radiation absorbing pigment which, when selectively heated in accordance with a pattern of radiation, momentarily softens adjacent portions of the adhesive material. Upon separation of the accepting tape and donor web, microgranules transfer to the accepting tape only in irradiated areas.

Tagging explosives with organic microparticles

Abstract: Tagging explosives by incorporating microparticles of a tackfree organic carrier, which microparticles have a distinctive geometric shape 1-250 micrometers in size. The microparticles contain tagging elements in uniform amounts of at least 0.1% of the total weight of each microparticle. By incorporating uniquely coded microparticles into each unit of production of explosive, any unit of production can be retrospectively identified by recovering and analyzing a single microparticle.

Low density abrasive pad having different abrasive surfaces

Abstract: An abrasive pad, especially useful in cleaning and scouring kitchen utensils, is comprised of a lofty fibrous nonwoven structure of mixed denier nylon or polyester crimped filaments bonded at contacting points with thermosetting resin containing finely divided soft abrasive and coated on one of its surfaces with thermosetting resin containing finely divided hard abrasive. The pad surface containing soft abrasive provides a mildly abrasive surface capable of cleaning, without harmfully scratching, non-stick plastic pan coatings (e.g., "Teflon" perfluoroethylene polymer), plastic dishes, etc. The pad surface containing the hard abrasive provides an aggressive abrasive surface capable of scouring stainless steel or aluminum pots and pans soiled with baked-on or burned cooking residues.

Easily rupturable band of tape

Abstract: A band of tape that may be easily ruptured is applied around an article by use of a tape assembly that comprises a heatshrinkable backing, a layer of adhesive carried on the backing for adhering the tape assembly to the article, and a non-adhesive tear strip that is narrower than the backing and is positioned between the layer of adhesive and the article. Short longitudinally extending cuts, parallel to, and on both sides of the tear strip, are made in an end of the backing that is exposed when the tape assembly is wrapped around the article. After application of the tape assembly around an article, the tape assembly is subjected to an elevated temperature sufficient to shrink the backing. Since the backing shrinks, while the tear strip adhered to the backing by the layer of adhesive either does not shrink or shrinks less than the backing, the portion of the tape assembly located between the longitudinal cuts in the backing curves outwardly to form a pull-tab.

Composition for filling, patching and the like

Abstract: Light weight patching, caulking or sealing composition which is especially useful for filling dents in automobile bodies. A conventional liquid thermosetting polyester resin, generally containing solid particulate inorganic filler, is additionally filled with small hollow filler particles. The composition is rendered thixotropic, storage stable, spreadable, and self-leveling by dissolving in the resin minor amounts of cellulose acetate butyrate or related mixed esters of cellulose. After hardening, the composition is easily sanded to the desired contour; paint applied thereover forms a smooth coat, which, surprisingly, is free of pockmarks.

Magnetic security document and method for making same

Abstract: A security document having a magnetic recording layer containing uniformly dispersed magnetizable material having magnetic anisotropy wherein the material at a plurality of selected locations is differently physically aligned with respect to a reference location to provide a magnetically detectable permanent fixed information pattern such as a code pattern useful for authenticating the document. The document is authenticated in the following manner. A magnetic field is applied to the document to cause the material within the plurality of selected locations to be differently magnetized according to the physical alignment thereof. The differently magnetized selected locations are subsequently sensed by traversing the document past a sensor device to provide a signal representative of the plurality of selected locations. This signal is compared with a predetermined signal pattern to authenticate the document.

System and method for authenticating and interrogating a magnetic record medium

Abstract: A magnetic record medium including a sheet having a layer containing magnetically anisotropic particles wherein the particles are permanently physically aligned at selected locations to form a fixed information pattern, is used in an authentication system in which the medium is subjected to magnetizing fields along two transverse directions to differently magnetize the particles depending upon the physical alignment thereof with respect to the field. The different magnetizations are sensed to produce signals representative of the selected locations, which signals are compared to authenticate the medium. The medium is further used in information processing systems in which a substantially unidirectional magnetizing field differently magnetizes the differently physically aligned particles, and in which the different magnetization is sensed to produce a signal representative of the fixed information.

Encapsulated isocyanurate catalyst

Abstract: A one-part, room temperature-latent isocyanate-catalyst system trimerizable to polyisocyanurate is formed comprising an aromatic isocyanate having dispersed throughout liquid microcapsules of a catalyst for isocyanurate formation. The microcapsules have a permeable shell wall essentially of partially polymerized aromatic isocyanates which encapsulates the liquid catalyst at room temperature but on activation of the isocyanate-catalyst system by a suitable force the liquid catalyst permeates the shell wall, mixes with the polyisocyanate, and cures the isocyanate to a fully cured thermoset isocyanurate material.

First aid bandage

Abstract: A first aid bandage is disclosed comprising a flexible backing, preferably microporous, having an adhesive layer applied thereover with an absorbent pad covering an intermediate portion of said backing and secured thereto by said adhesive layer and a strip of microporous breathable surgical tape superposed over said absorbent pad and lightly adhered to the adhesive of said flexible backing while having its adhesive surface exposed such that the entire surface of the first aid bandage is adhered to a wound site.

Precision molded refractory articles and method of making

Abstract: A precision molded refractory article, which can have an intricate geometry with fine surface detail, such as an electrical discharge machining electrode, is made by molding in a flexible mold a plastic mixture of multi-modal refractory powders and a thermoplastic binder to form a green article of predetermined shape and dimensions, heating the green article to remove said binder and consolidate the refractory powders with very minimum shrinkage of the article, infiltrating the resulting porous article or skeleton with a molten infiltrant of a low melting point metal or alloy, and cooling the infiltrated skeleton, thereby forming a precision refractory article having a uniform high density, a useful working surface free of machined or otherwise disturbed metal, and a shape and dimensions precisely conforming to said green article.

Pressure sensor and instrument utilizing same

Abstract: A pressure indicating instrument including first and second conductors and a layer of compressible insulating material interposed between the conductors for normally holding the conductors out of electrical contact The layer is compressible to allow the conductors to move toward each other and into electrical contact An indicator is coupled to the conductors for indicating whether the conductors are in electrical contact

Electrographic recording process and apparatus employing synchronized recording pulses

Abstract: An improved electrographic recording process and apparatus are provided wherein a recording medium is arranged between two spaced opposed electrodes, one of which is in contact with one side of the recording medium, and the other of which is a recording electrode that indirectly contacts the opposite side of the recording medium through an electrically conductive, magnetically attractable toner powder. Such toner is drawn into a recording region between the recording electrode and the recording medium by an alternating magnetic field, and an electrical record signal of short duration is applied to one of the electrodes at such time that the alignment of the toner in the recording region is at an optimum for providing toner deposition on the recording medium.

Static mixing device

Abstract: A static in-line mixing tube for mixing a plurality of fluids during their passage through the tube comprises a hollow tube packed with shaped pieces, each comprising a disc having at least one projection perpendicularly attached thereto.

Coated aluminum substrates having a binder of aluminum hydroxyoxide

Abstract: Aluminum substrates are provided having a coating of particulate material bound thereto by means of an in situ formed binder of aluminum hydroxyoxide. The coated aluminum constructions have utility in imaging and reproduction process (e.g., as printing plates, as electrographic elements, etc.), as magnetic recording surfaces, controlled roughness surfaces, decorative panels, protective surfaces, etc.

Friction-surface sheet

Abstract: A flat, backing layer of uniform thickness of biaxially oriented, heat set polyethylene terephthalate having adherently bonded to its upper surface a textured, tough, scuff-resistant, weather-resistant layer of certain thermoplastic ethylenic copolymers, and a normally tacky pressure-sensitive adhesive layer adherently bonded to its lower surface, provides a friction-surface sheet for use on stairs, in bath tubs and showers, and on other surfaces which may be inherently undesirably slippery. The friction-surface sheet is made by coating a thin, ultra-violet light transmissive self-sustaining layer of a coherent film forming thermoplastic polymer onto the polyethylene terephthalate layer, irradiating the interface between the layers to cause adherent bonding, coating the ethylenic copolymer on top of the polymer layer by melt fusion, and embossing the copolymer layer to provide the textured surface. Pressure-sensitive adhesive is then applied to the lower surface of the sheet to facilitate mounting thereof on any of a variety of substrates.

Color photographic developing solution

Abstract: Color development of a silver halide photographic element containing dispersed couplers is improved by developing the elements in the presence of an alkyl glycol ether or an aryl glycol ether.