Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B25/00—Layered products comprising a layer of natural or synthetic rubber
  • B32B25/04—Layered products comprising a layer of natural or synthetic rubber comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B25/08—Layered products comprising a layer of natural or synthetic rubber comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
  • A61P31/04—Antibacterial agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets
  • G03G7/002—Organic components thereof
  • G03G7/0026—Organic components thereof being macromolecular
  • G03G7/004—Organic components thereof being macromolecular obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/006—Substrates for image-receiving members; Image-receiving members comprising only one layer
  • G03G7/0073—Organic components thereof
  • G03G7/008—Organic components thereof being macromolecular
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/75—Printability
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2323/00—Polyalkenes
  • B32B2323/10—Polypropylene
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Definitions

• thermoplastic films which are capable of receiving ink derived from liquid toner, especially liquid toner employed in electrostatic printing.
• Electrostatic printing is a very effective method of image transfer commonly used in photocopying and photo printing.
• a potential electrostatic image is formed on an imaging surface carrying a uniform electrostatic charge.
• the uniform electrostatic charge can be created by exposing the surface to corona discharge.
• the uniform electrostatic charge is then selectively discharged by exposing it to a modulated beam of light which corresponds to an image formed from an original.
• the discharged surfaces form the background while the charged surfaces form the print image.
• the print image is developed by applying pigmented toner particles which adhere to the charged “print” portions of the surface.
• the pigment is subsequently transferred by various techniques to a copy sheet.
• Dry toner is most commonly used in electrostatic printing.
• the quality and clarity of the image and image resolution is related to the size of the toner particles. While it is thought that very fine particles will produce a finer image, there is a practical limitation on the size of toner particles which can be used. Dry toner particles must be of sufficient weight and size to be deposited onto the print surface without becoming airborne, which is thought to lead to machinery fouling and, possibly, environmental problems. Additionally, in fixing the image, the dry toner particles are fused onto the paper by exposure to very high temperatures, e.g. in excess of about 400° F. (204° C.). This energy requirement is a significant drawback.
• Paper is widely used as the image receiving element in electrostatic imaging. It would be advantageous to use plastic as the receiving element. Among other advantages over paper, plastic is moisture resistant, flexible and heat sealable and plastic substrates can be either clear or opaque. However, the high temperatures necessary for imaging with the dry toners will melt plastic films and the liquid toners do not transfer well and adhere to uncoated plastic.
• Plastic films which can receive printing inks have been disclosed; however, these films require specialized treatment to enable them to receive the dry toner.
• a layer of plastic film used as a laminate for corrugated paperboards is disclosed in U.S. Pat. No. 4,871,406.
• the film is a thermoplastic co-extruded polymeric film, such as, polypropylene with ethylene acrylic acid.
• This film can receive printing inks only after being treated with a corona discharge device or a high velocity flame.
• U.S. Pat. No. 4,853,290 discloses laminates of polypropylene film prepared by coextruding a polymer composition onto a polypropylene film. This polypropylene film requires corona treatment after printing on its surface.
• Corona and flame treatments oxidize a plastic surface in order to enable the fixing of dry printing inks. Besides adding time, money and inconvenience to the production process, these treatments pose safety and environmental hazards.
• a corona treatment process generates toxic ozone so the atmosphere in the treating step must be contained and exhausted from the operating area. At high film speeds, a layer of air that contains ozone adheres to the film as it leaves the treating enclosure. This layer must be removed from the film by close-fitting baffles or a vacuum system. In some cases corona treatment requires special chambers and needs to be carried out off-line.
• Flame treatment entails impinging a flame directly onto a film surface as the film is moved across a cooling roll. The complexity of controlling the flame-treating process presents safety hazards.
• liquid toners have been developed in which the toner is dispersed in a solvent. The solvent is removed in the last printing step by the mechanism of the press. Because of the liquid medium, very fine dye particles can be employed without concern for the particles becoming airborne. Thus, copies of very high resolution can be made and high temperatures needed to fuse dry toners are not required.
• Liquid toners for electrostatic imaging are described in U.S. Pat. Nos. 5,225306; 5,276,492; 5,346,769 and 5,407,771.
• Typical systems used for coating plastic films are the dispersion, solvent and extrusion coating processes.
• the dispersion coating system is a multi-step, complex process that requires vigilant monitoring.
• the dispersion coating process involves unwinding the film, applying the coating uniformly at the desired thickness, waiting for the coating to dry and rewinding the film into a uniform roll.
• Coating thickness should be measured across the film as part of the coating sequence. This can be done using radiation absorption. As the chemical nature of the coating more nearly approaches the substrate, this measurement becomes increasingly difficult.
• the conditions of the dispersion coating process must be carefully monitored in order to ensure adequate coalescence of the coating.
• the dispersion coating polymer is dispersed in water often with a surfactant. Once the coating is applied, the water is evaporated. In order for a film to form, conditions need to be highly regulated. If evaporation occurs at room temperature, the dried polymer usually forms a fragile, uncoalesced coating. The particles need to make intimate contact with each other in order for coalescence to occur. Then diffusion and interpenetration of the polymer molecules must occur readily across the particle interfaces. The effectiveness of this diffusion depends on the mobility of the polymer molecules which in turn depends on the temperature of and the viscosity of the liquefying particle, which is a function of molecular weight.
• the surfactant used to create a stable dispersion can act as a barrier to interpenetration at the surface of the particles. Therefore an optimum must be found in the concentration of the surfactant.
• the solvent coating system also entails a multi-step process. This process involves unwinding the film, applying the coating uniformly at the desired thickness, waiting for the coating to dry and rewinding the film into a uniform roll.
• the desired film thickness can be achieved by the use of radiation absorption.
• thermoplastic film which is capable of receiving ink derived from liquid toner without the need of, among other things, coating(s) and/or post-extrusion or post-printing processes.
• the present invention provides an ink-based-image-bearing substrate.
• This substrate includes a coextruded thermoplastic film having at least one layer made from a polymer derived from polypropylene and another layer made from a polymer bearing an acidic functional group.
• the layer which includes the polymer derived from the polypropylene is oriented in at least the machine direction.
• the layer which includes the polymer bearing an acidic functional group is the print-receiving layer.
• Liquid toner ink is electrostatically printed on the layer which includes the polymer bearing an acidic functional group.
• the polymer bearing an acidic functional group is preferably ethylene-acrylic acid or ethylene methacrylic acid.
• the invention includes a method for providing the ink-based-image-bearing substrate.
• the ethylene-acrylic acid copolymer layer of the film preferably has an acrylic acid content in the range of 1.0 to 18.0 wt %, and the most preferred range is from 2.0 to 6.0 wt %.
• the ethylene-methacrylic acid copolymer layer of the film preferably has an methacrylic acid content in the range of 1.0 to 18.0 wt %, and the most preferred range is from 2.0 to 6.0 wt %.
• thermoplastic film has a layer made from a polymer bearing an acidic functional group, especially with an optimal acid content, liquid toner can be used in electrostatic imaging of the film without the difficulties presented by coating processes.
• thermoplastic films adds time, money and inconvenience to the production process.
• Coating systems are multi-step, complex processes requiring extensive physical manipulation of the substrate films. Such processes include unwinding the substrate film, applying the coating, allowing the coating to dry and rewinding the film into a uniform roll. Achieving the desired thickness for a coating may involve the use of radiation absorption.
• solvent-based coatings present the additional problems of environmental hazards pertaining to solvent disposal. Furthermore, solutions used in these solvent-based coatings are sensitive to ambient conditions, such as temperature and atmospheric moisture which further complicate the production process
• Extrusion coating systems further present limitations with respect to the substrate films and polymer melts that can be used.
• the ethylene-methacrylic acid preferably has a methacrylic acid content from a range of 1.0 to 18.0 wt %, and most preferably having a methacrylic acid content of about 2.0 to 6.0 wt %.
• the ethylene content of the copolymer can be from about 82.0 to 99.0 wt .%, preferably 94.0 to 98.0 wt % of ethylene, while from about 1 to 18.0 wt. % can be of acrylic acid or methacrylic acid.
• Ethylene acid copolymers belong to a family of ethylene copolymers in which the polyethylene chain is modified by the presence of pendant carboxyl groups. These copolymers are characterized by good toughness and adhesion to a variety of metallic and nonmetallic substrates. Ethylene acid copolymers are produced by the high pressure free radical copolymerization of acrylic acid or methacrylic acid with ethylene to form ethylene acrylic acid or ethylene methacrylic acid. When ethylene is copolymerized with acrylic acid or methacrylic acid, the molecular structure is significantly altered by the random inclusion of bulky carboxylic acid groups along the backbone and side chains of the copolymer. The carboxyl groups are free to form bonds and interact with any polar substrate.
• the carboxyl groups disrupt the linearity of the polyethylene backbone and reduce the total crystallinity.
• a commercially available ethylene-acrylic acid copolymer is Primacor 4983 sold by Dow Chemical Co.
• the ethylene-acrylic acid is often supplied as a resin.
• Polypropylenes commercially suitable for this invention include Fina 3371 (available from Fina Oil and Chemical Co. of Dallas, Tex.), Exxon 4612 and Exxon 4252 (available from Exxon Chemical Co. of Houston, Tex.) and Amoco 6361 (available from Amoco Chemical Co. of Chicago, Ill.).
• the ethylene-acrylic acid copolymer layer of the film has a softening point in a range of 180°-220° F., which is lower than the orientation temperature for oriented polypropylene. This feature allows for additional smoothing of the ethylene-acrylic acid surface which enhances the printability of the surface.
• the films of this invention can contain a relatively inert particulate filler additive.
• a filler which has found specific utility in the coextruded film of this invention is fumed silica.
• the fumed silica is composed of particles which are agglomerations of smaller particles and which have an average particle size of, for example, about 2 to 9 microns, preferably about 3 to 5 microns.
• any finely divided inorganic solid materials such as silica is contemplated as a useful filler for purposes of the present coextruded film. These include talc, calcium carbonate, diatomaceous earth, calcium silicate, bentonite and clay.
• the total amount of filler typically ranges from about 0.1% to about 80%, specifically from about 0.3% to 7.0% based on the entire weight of the coextruded film. When a clear film is needed the particulate concentration will be relatively low, for example from about 0.1% to about 10%, specifically from about 0.3% to about 7.0%.
• the particulates are generally small in size, typically ranging from about 1 m to about 10 m specifically from about 3 m to about 7 m.
• Further examples of fillers include kaolin, silica, aluminum silicates, clay and talc. Pulp is also contemplated.
• Preferred among the foregoing fillers are those that function as antiblock/slip agents.
• Silica is a specific example of a filler which is found to function in this manner.
• Opacity enhancing particulates may also be employed. These are relatively inert substances. Calcium carbonate is extensively used in thermoplastics since it is relatively inexpensive and easy to use. It can be used in its natural form but “precipitated calcium carbonate,” which is prepared by chemical processes, can be employed. Sometimes, particles of calcium carbonate are coated with a resin to reduce plasticizer absorption and this form can also be employed.
• the filler can also include pigment-imparting particulates.
• Pigments contemplated are organic or inorganic substances with particle sizes which are rarely less than 1 micron in diameter. Typical pigments include carbon black and titanium dioxide. Calcium carbonate can also act as a pigment.
• Other pigments not to be excluded by this invention are metallic pigments such as particles of aluminum, copper, gold, bronze or zinc. These pigments are usually flake shaped particles which reflect light when incorporated into the coextruded film.
• the fillers including inert particulate slip/antiblock agents, opacifying agents, and/or pigments can be used in combination, depending upon the desired degree of translucency or opacity.
• the concentration is less than about 70% of the total particulate concentration of the film, specifically about 20% to about 50% of the total particulate concentration of the film.
• particulates which may be employed in addition to those noted above include acetylene black, alpha cellulose, aluminum silicates, barium sulfate, calcium silicate, calcium sulphate, cellulose, clays, diatomite, glass flake, keratin, lignin, lithophone, mica, microballoons, molybdenum disulfide, nepheline syenite, paper, pulp, quartz, shell flour, talc, vermiculite and wood.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Public Health (AREA)
• Organic Chemistry (AREA)
• Pharmacology & Pharmacy (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Veterinary Medicine (AREA)
• Medicinal Chemistry (AREA)
• Oncology (AREA)
• Communicable Diseases (AREA)
• Laminated Bodies (AREA)
• Printing Methods (AREA)
• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

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• 1998
  • 1998-09-10 US US09/151,129 patent/US20010053434A1/en active Granted
  • 1998-09-10 US US09/151,129 patent/US6331346B1/en not_active Expired - Lifetime
• 1999
  • 1999-09-09 WO PCT/US1999/020563 patent/WO2000015424A1/en not_active Ceased
  • 1999-09-09 JP JP2000569995A patent/JP2002524781A/ja not_active Withdrawn
  • 1999-09-09 CA CA2343149A patent/CA2343149C/en not_active Expired - Fee Related
  • 1999-09-09 AT AT99946801T patent/ATE286807T1/de not_active IP Right Cessation
  • 1999-09-09 AR ARP990104547A patent/AR022086A1/es unknown
  • 1999-09-09 BR BR9913568-0A patent/BR9913568A/pt not_active Application Discontinuation
  • 1999-09-09 EP EP99946801A patent/EP1115559B1/en not_active Expired - Lifetime
  • 1999-09-09 ES ES99946801T patent/ES2237152T3/es not_active Expired - Lifetime
  • 1999-09-09 DE DE69923195T patent/DE69923195T2/de not_active Expired - Lifetime
  • 1999-09-09 AU AU59127/99A patent/AU751775B2/en not_active Ceased

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