Showing papers by "3M published in 1999"

Color shifting film

Abstract: Multilayer polymeric films and other optical bodies are provided which are useful in making colored mirrors and polarizers. The films are characterized by a change in color as a function of viewing angle.

Modified copolyesters and improved multilayer reflective films

Abstract: A multilayered polymer film includes a first set of optical layers and a second set of optical layers. The first set of optical layers is made from a polyester which is often birefringent. The polyesters of the first set of optical layers typically have a composition in which 70-100 mol % of the carboxylate subunits are first carboxylate subunits and 0-30 mol % are comonomer carboxylate subunits and 70 to 100 mol % of the glycol subunits are first glycol subunits and 0 to 30 mol % of the glycol subunits are comonomer glycol subunits, where at least 0.5 mol % of the combined carboxylate and glycol subunits are comonomer carboxylate or comonomer glycol subunits. The multilayered polymer film may be used to form, for example, a reflective polarizer or a mirror.

Process for making multilayer optical films

Abstract: Methods and apparatuses are provided for the manufacture of coextruded polymeric multilayer optical films. The multilayer optical films have an ordered arrangement of layers of two or more materials having particular layer thicknesses and a prescribed layer thickness gradient throughout the multilayer optical stack. The methods and apparatuses described allow improved control over individual layer thicknesses, layer thickness gradients, indices of refraction, interlayer adhesion, and surface characteristics of the optical films. The methods and apparatuses described are useful for making interference polarizers, mirrors, and colored films that are optically effective over divers portions of the ultraviolet, visible, and infrared spectra.

Radiopaque cationically polymerizable compositions comprising a radiopacifying filler, and method for polymerizing same

Abstract: Polymerizable compositions that include: (a) a cationically active functional group; (b) an initiation system capable of initiating cationic polymerization of the cationically active functional group; and (c) a filler composition that includes various radiopacifying fillers in an amount sufficient to render the polymerizable composition radiopaque. Components (a), (b), and (c) are selected such that the polymerizable composition polymerizes to form a polymerized composition having a Barcol hardness, measured using a GYZJ-935 meter, of at least 10 within 30 minutes following initiation of the cationically active functional group at a reaction temperature of 25° C.

Face mask that has a filtered exhalation valve

Abstract: A filtering face mask that covers at least the nose and mouth of a wearer and that includes an exhalation valve. The exhalation valve opens in response to increased pressure when the wearer exhales to allow the exhaled air to be rapidly purged from the mask interior. An exhale filter element is placed in one of several locations in the exhale flow stream to remove contaminants from the exhaled air. The face mask is beneficial in that it provides comfort to the wearer by allowing warm, moist, high-CO2-content air to be rapidly evacuated from the mask interior through the valve and also protects the wearer from splash fluids and polluted air while at the same time protecting other persons or things from being exposed to contaminants in the exhale flow stream.

Photovoltaic powering and control system for electrochromic windows

Abstract: A sealed insulated glass unit is provided with an electrochromic device for modulating light passing through the unit. The electrochromic device is controlled from outside the unit by a remote control electrically unconnected to the device. Circuitry within the unit may be magnetically controlled from outside. The electrochromic device is powered by a photovoltaic cells. The photovoltaic cells may be positioned so that at least a part of the light incident on the cell passes through the electrochromic device, providing a form of feedback control. A variable resistance placed in parallel with the electrochromic element is used to control the response of the electrochromic element to changes in output of the photovoltaic cell.

Contoured layer channel flow filtration media

Abstract: A filtration media array is provided having at least one contoured polymeric film layer having surface structures. The film layers may be configured as a stack that has the contoured film layer defining a plurality of ordered inlet openings through a face of the stack and corresponding air pathways, thereby forming an open, porous volume. The air pathways may be defined by a plurality of flow channels formed by the contours of the structured contoured film layers.

Tamper-indicating article for reusable substrates

Abstract: A tamper-indicating article comprises (a) a pressure-sensitive adhesive film or pressure-sensitive adhesive-coated tape that can be removed, without exhibiting cohesive failure, from a substrate surface (e.g., an automobile windshield) by stretching the film or tape; and (b) at least one damageable layer that shows cohesive or intralayer failure when an attempt is made to remove the article from the substrate surface. The article is especially useful for application to valuable, non-disposable substrates and can be removed therefrom without substrate damage.

Outdoor advertising system

Abstract: The present invention is an outdoor advertising or display system including a multi-layer graphic article intended for application to an outdoor surface such as concrete, asphalt and the like. The advertising system includes an imageable base layer and an image-protective surface layer that can be laminated to the base layer following imaging of the base layer. The image-protective surface layer is frictionally modified to provide an anti-skid layer for surface traffic.

Fused glassy particulates obtained by flame fusion

Abstract: The disclosure describes methods for producing bulk, particulate material that includes solid, generally ellipsoidal particles. Irregularly shaped feed particles with average particle sizes of up to 25 microns on a volume basis are dispersed in at least a portion of a combustible gas mixture by application of force and/or fluidizing agents. The combustible mixture with particles in suspension is then delivered, while controlling agglomeration or re-agglomeration of the particles, to at least one flame front. There, the mixture and suspended particles are uniformly distributed across the surface(s) of and passed through the flame front(s) with a high concentration of particles in the mixture. This flame front and the resultant flame(s) with suspended particles are located in at least one “wall free” zone. In such zone(s) the flame(s) may expand while the particles are maintained in dispersion and heated, with controlled and highly efficient application of heating energy. At least partial fusion occurs within at least the surfaces of the particles at high thermal efficiencies, while agglomeration of particles during fusion is inhibited.

Abrasive articles including an antiloading composition

Abstract: An abrasive article comprising a backing, a plurality of abrasive particles, a binder which adheres the abrasive particles to the backing, and a peripheral coat including an antiloading component is provided. The antiloading component is of the formula (CnH2n+1)-COO-M, wherein n is greater than 17 and M is selected from Group 1 of the Periodic Table, with the proviso that when M is lithium, n is greater than 21. The antiloading component can be included in a coated abrasive article, such as a lapping or structured abrasive article, and a nonwoven abrasive article.

Free radical polymerization method

Abstract: In one aspect the invention provides an energy efficient polymerisation method comprising irradiating a polymerizable composition and a photoinitiator with a source of essentially monochromatic radiation where the photoinitiator and the wavelength of the radiation source are selected such that the extinction coefficient of the photoinitiator at the peak wavelength of the source is greater than about 1000 M-1 cm-1 and such that the photoinitiator absorbs at least two percent of the actinic radiation incident on the coating. In another aspect the invention provides energy efficient methods of polymerizing polymerizable compositions and cross-linking cross-linkable compositions by irradiating the respective compositions with a low power source of essentially monochromatic radiation. The low power energy sources have an input power of less than about 10 W/cm. Articles made from the above methods, including polymer films having release coatings, adhesive coatings, hard coatings and the like thereon, also are provided.

Guest-host polarizers

Abstract: A polarizer is described that is formed of a host matrix and a guest dye. The host matrix may be a lyotropic liquid crystal matrix having a predetermined orientation. A guest pleochroic dye may be disposed within the host lyotropic liquid crystal matrix. The guest pleochroic dye is oriented by the orientation of the host matrix.

Display substrate electrodes with auxiliary metal layers for enhanced conductivity

Abstract: A method for enhancing the conductivity of transparent conductive electrodes on display substrates by providing patterned auxiliary metallic layers adjacent to the transparent conductive material. The method of the present invention eliminates the need for aligning the auxiliary metal layers (26) with transparent conductive electrodes (22) a) by using an inclined collimated beam of metallic material (28) for depositing a metal coating (26) on resist strips (24), or b) by providing resist residuals at the corner of the metal coating, or by forming a contignous metallic coating with a periodic array of holes therein which can be etched simultaneously with the underlying transparent conductive layer.

Time-temperature integrating indicator device with barrier material

Abstract: A time-temperature indicator device provides a visually observable indication of the cumulative thermal exposure of an object. The device includes a substrate having a diffusely light-reflective porous matrix and a backing. The backing includes on its surface a viscoelastic indicator material for contacting the substrate and a barrier material for substantially inhibiting the lateral flow of viscoelastive indicator material between the substrate and the backing.

Abrasion and stain resistant curable fluorinated coating

Abstract: A heat curable fluorochemical coating composition is disclosed comprising an amino resin crosslinking agent, an addition copolymer of a fluorinated monomer having a fluorocarbon group of at least three carbon atoms and a non-fluorinated monomer having a crosslinking group capable of reacting with said amino resin at elevated temperature and a hardening agent capable of crosslinking with said amino resin at elevated temperature. The coating composition is useful for providing anti-stain and/or stain release properties to a variety of substrates.

Abrasive article and method of grinding glass

Abstract: The present invention is a fixed abrasive article for grinding or polishing the surface of a glass workpiece. The abrasive article for grinding glass has abrasive composites containing a binder, an alkaline metal salt, and diamond abrasive particles or agglomerate particles comprising diamond particles, the composites integrally molded to a backing. The abrasive article for grinding glass is capable of removing between about 200 and 400 micrometers of glass using an RPP procedure having a polish time interval of between 10 and 15 seconds, generally about 12 seconds. The abrasive article for polishing glass comprises a backing containing fibers, and a plurality of abrasive composites integrally molded to the backing comprising an organic resin, ceria abrasive particles, and alkaline metal salt. The abrasive articles for polishing glass also provide an optimum rate of breakdown of the abrasive composites and improved adhesion between the abrasive composites and the backing.

Multi-component unidirectional graphic article

Abstract: The present invention relates to graphic or informational articles (10) that may be applied to a surface of a translucent or substantially clear substrate (60) so that the image may be viewed through the substrate. The graphic articles of the present invention include a perforated imageable component (12) and a non-perforated attachment component (14). The imageable component includes an opaque, perforated imageable film layer (16) that accepts an image layer (50) on its first major surface (18). On the second major surface (20) of the imageable film layer, a perforated, opaque light absorbing film (22) is applied. The attachment component includes a substantially transparent scrim layer (30) of a polymeric film. This scrim layer is un-perforated and includes a pressure sensitive adhesive (36) on its first major surface (32); a heat activated adhesive (40) on its second major surface (34). After the imageable film layer is imaged, the heat activated adhesive may be used to laminate the attachment component to the imageable component to create a finished graphic article. The pressure sensitve adhesive on the attachment component may then be used to attach the graphic article to the transparent substrate (60). When the graphic articles of the present invention are mounted on a transparent substrate, an observer (70) on one side of the substrate may view an image or a message through the substrate, and an observer (72) on the opposite side of the substrate enjoys a substantially unobstructed view through the image and the substrate.

Microstructure liquid dispenser

Abstract: Liquid dispenser (10) comprising a reservoir (12) including a plurality of elongated channels (18) formed from overlaying layers (14) of microstructured film having a dispensing edge (22), each elongated channel having an outlet (20) at the dispensing edge (22), wherein liquid can be stored in the reservoir (12), and a transfer element (42) in fluid communication with the dispensing edge of the reservoir (12) that provides a location from which liquid stored in the reservoir can be controllably dispensed.

Variably printed tape and system for printing and applying tape onto surfaces

Abstract: An apparatus (10) for printing variable information on a tape (14) to form a tape segment, cutting the tape segment to form a tag (8), and applying the tag onto an object includes a printer (18) for printing information onto the tape segment. A controller (20) controls the printer in response to input to vary the information printed onto the tape. The printed tape segment is transported to a location for application onto the object and is cut. An adhesive tape (14) can have variable information printed on it and can be applied onto an object. The tape includes a backing layer and an adhesive layer on the first side of the backing layer. At least one of the backing layer and the adhesive layer are colored to yield a tape opacity of greater than (60). The tape can have a scan rating of at least C when applied on a black background and an opacity of at least (65). The tape can achieve specific scan ratings when adhered to surfaces that have color coordinates including combinations of a*, b*, and L* that are selected in combination with each other.

Intumescable fire stop device having quick fasteners

Abstract: An intumescable fire stop device and method of installing the same including a collar and a fastening device. The collar includes intumescable material supported by a jacket. The fastening device includes an axial shaft portion, a radial shank portion and a means to attach the fastening device to the collar. The radial shank portion is placed through an opening in a wall or other rigid surface through which a pipe or other member extends and between the wall and the pipe. The radial shank portion is then extended on the far side of the wall to engage the far side of the wall and firmly secure the collar to the near side of the wall.

Ablated laser feature shape reproduction control

Abstract: This invention concerns a process useful for increasing the accuracy of the shape of a laser ablated feature formed on a substrate, especially where the substrate is a polymeric article. The process includes irradiating the polymeric article with laser light that has passed through a retardation plate selected from stationary adjustable plates, rotating plates or spinning plates, preferable in multiples of quarter-waves or half-waves. This invention also concerns a laser apparatus useful for making ablated features in a substrate having a radiation source; a mask positioned between the radiation source and a substrate to be irradiated, and a retardation plate which is stationary and adjustable, rotating or spinning plates.

Secondary loop refrigeration system

Abstract: A method and apparatus are provided for using certain hydrofluoroethers (HFEs) as low temperature heat transfer media in secondary loop refrigeration systems. These materials exhibit a low, somewhat linear Temperature Difference Factor over the temperature range of -15° C. to -65° C., making them ideal for use as low temperature heat transfer media. The HFEs of the present invention are nonflammable, nontoxic, environmentally benign, and have a high heat transfer capacity and low viscosity over the required operating temperatures. Furthermore, since these materials have high boiling points and low freezing points, they are not prone to phase changes over the required operating temperatures, and do not require pressurized systems.

Internally damped rotatable storage article

Abstract: The present invention provides a method for internally damping a rotatable storage article which is subject to resonant vibrations. More specifically, the present invention provides a method of improving the damping properties of a rotatable storage article by introducing a viscoelastic material as an inner layer(s) of the rotatable storage article. The invention also provides the damped rotatable storage articles themselves.

Applicator for a coreless tape roll

Abstract: An applicator for a lint removal device includes a handle portion connected to a tape-receiving portion. The tape-receiving portion includes a tape-receiving surface, an inner lip, an outer lip, and grooves adjacent the lips. The outer lip is tapered. After a roll of tape traverses over the outer lip it is locked in place on the tape-receiving surface and cannot be removed by sliding it back over the outer lip.

Roll stabilizing release liner

Abstract: A release liner providing more roll stability (i.e., the coils forming the roll are less likely to fall apart when the roll is held suspended along its outer circumferential edge) when used with double-sided tape having a heat activated adhesive ('HAA') side and a pressure sensitive adhesive ('PSA') side. The release liner includes a front liner side comprising a release layer in contact with, bonded to and readily removable from the PSA side and a back liner side comprising a roll stability layer. The roll stability layer comprises an ethylene vinyl acetate and contacts the HAA side when the adhesive tape assembly is formed into a roll.

Uniform meltblown fibrous web and methods and apparatus for manufacturing

Abstract: Multilayer meltblown fibrous webs, as well as apparatus and methods of forming the webs. The webs are produced on a rotating collector that also moves parallel to its longitudinal axis. The webs are thus formed in a helical process, and the resulting tubular web is separated in a direction parallel to a helix angle. By separating the tubular web in a direction parallel to the helix angle, a flat multilayer meltblown fibrous web is provided that allows for incorporation of feathered edges formed during the article's manufacture.

Protective enclosure for a multi-chip module

Abstract: A heat dissipating element, positioned inside a protective cover, removes heat from the vicinity of a multi-chip module comprising active semiconductor devices attached to a printed circuit board. Attachment of the protective cover to the printed circuit board uses a latching mechanism with minimum board space requirements.

Cleaning pads formed from non-woven abrasive web material, especially for domestic use

Abstract: A dispenser package comprises a box-shaped dispenser (12) containing a longitudinally-extending web (6) of lofty, non-woven, abrasive material comprising fibres having a tenacity of at least 7.0 g/dtex., which is partially cut, at intervals along the length of the web, along bowed transverse lines (2) enabling the web to be separated readily into pads (3). The web, which has a thickness less than 1 cm and a weight less than 500 g/m2, is Z-folded at the joins (5) between adjacent pads and can be withdrawn from within the dispenser through a slot-shaped opening (10) in the latter.

Method of producing porous calcined polyimide

Abstract: Object: to provide a porous polyimide whose dielectric constant and refractive index are lowered while maintaining intrinsic performances of a polyimide, such as heat resistance, etc., and which is highly transparent. Means for solving: a porous polyimide comprising a polyimide containing matrix, and a plurality of micropores dispersed in said matrix, characterized in that said micropores are formed by removing a hydrophilic polymer from a precursor comprising a polyimide-containing matrix, and the hydrophilic polymer dispersed in said matrix, and that the porous polyimide has light transmittance of no less than 70 %.