Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
  • B41M5/132—Chemical colour-forming components; Additives or binders therefor
  • B41M5/155—Colour-developing components, e.g. acidic compounds; Additives or binders therefor; Layers containing such colour-developing components, additives or binders
• • 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
• • 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
• • 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
• • 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

Definitions

• a method for printing carbonless forms on an electrostatic printer or copier which comprises: providing a recording sheet comprising a substrate, said substrate being coated with a coated front (CF) coating comprising a developer, hollow microspheres and a binder composition, wherein the binder composition comprises polyvinyl alcohol; and printing on the recording sheet with an electrostatic printer or copier.
• CF coated front
• binder composition further comprises at least one other binder material.
• binder composition further comprises a synthetic binder selected from the group consisting of polyvinyl acetate and copolymers thereof, styrene butadiene rubber (SBR), polystyrene, butadiene-styrene copolymers, polyvinylpyrrolidone, ethyl acrylate, butyl acrylate, methyl methacrylate, acrylamide and mixtures thereof.
• SBR styrene butadiene rubber
• polystyrene polystyrene, butadiene-styrene copolymers
• polyvinylpyrrolidone ethyl acrylate, butyl acrylate, methyl methacrylate, acrylamide and mixtures thereof.
• said binder composition further comprises a latex binder selected from the group consisting of sytrenebutadiene latexes, carboxylated sytrenebutadiene latexes, acrylic latexes, and acrylonitrile latexes.
• a latex binder selected from the group consisting of sytrenebutadiene latexes, carboxylated sytrenebutadiene latexes, acrylic latexes, and acrylonitrile latexes.
• said binder composition comprises from about 2 to 30 percent by dry weight of the CF coating.
• said CF coating comprises from about 2 to 12 percent by dry weight polyvinyl alcohol.
• said binder composition further comprises a styrenebutadiene latex
• said binder composition further comprises a starch binder.
• microspheres have a diameter from about 0.3 ⁇ to 15 ⁇ .
• a process for electrostatically printing carbonless sheets and producing a carbonless formset comprising: providing a plurality of carbonless sheets, including at least a first substrate containing a coating of an encapsulated color former and a second substrate containing a second coating comprising a color developer in a binder matrix of polyvinyl alcohol and latex, wherein the first and second substrates are positioned such that the first and second coatings are juxtaposed; printing said sheets on an electrostatic copier or printer; and applying adhesive to the formset sheets after the sheets have been printed on the electrostatic copier or printer thereby forming a collated formset wherein a coating containing an encapsulated color former is in contact with a coating containing a color former.
• said carbonless formset further comprises at least one intermediate sheet containing a coating of an encapsulated color former on one surface and a coating comprising a color developer in a binder matrix of polyvinyl alcohol and latex on the other surface.
• a method for printing carbonless forms on an electrostatic printer or copier which comprises: providing a recording sheet comprising a substrate, said substrate being coated with a coated front (CF) coating comprising from about 4 to 40% by dry weight of a developer, from about 5 to 50% by dry weight hollow microspheres and from about 2 to 30% by dry weight of a binder composition, wherein the binder composition comprises polyvinyl alcohol and a latex binder, said polyvinyl alcohol being from about 2 to 12 % and said latex binder being from about 2 to 10% by dry weight of said CF coating composition; and printing on the recording sheet with an electrostatic printer or copier.
• CF coated front
• said CF coating composition comprises from about 10 to 25%> developer, from about 7 to 20% microspheres, from about 4 to 9% polyvinyl alcohol and from about 3 to 6% latex binder based on dry weight of said CF coating composition.
• the present invention relates to carbonless copy paper, and more specifically to a carbonless CF recording sheet capable of being run on electrostatic copiers and printers without contaminating the components of the electrostatic device.
• Carbonless copy systems and other copying systems employing a color precursor and a developer are well known in the art. These systems can comprise two sheets, a transfer or donor sheet which contains a colorless color- forming agent on one of its surfaces which is often contained in pressure rupturable microcapsules and a developer or receiver sheet, which is typically a substrate having a layer of a developer material coated onto its front surface which can react with the colorless color-forming agent to form a visible image.
• the two sheets are juxtaposed so that the colorless color- forming agent faces the developer material.
• pressure such as a pen, pencil, typewriter, or other writing instrument
• the microcapsules are ruptured which releases the colorless color-forming agent.
• the color-forming agent reacts with the developer material on the developer sheet to form a visible image.
• CarbonJess papers are widely used in the forms industry. Typically, preprinted forms are compiled into a set or packet such that marking the top form will provide the required number of duplicates.
• the carbonless paper is prepared in precollated sets wherein sheets of various colors and surfaces are packaged in reversed sequence sets wherein the sheets are arranged opposite to their normal functional order. That is, the CF sheet is first in the set with the CB sheet being last, with the required number of CFB sheets therebetween. When the sheets are then printed in a printer which automatically
• precollated sheets can be arranged in their normal functional order.
• the contamination with the newer electrostatic devices is originating with the CF coating rather than the CB coating.
• the CF sheet As the CF sheet is fed through the paper transport system of the printer or copier, it encounters various pressure points in the device, such as, for example, feed belts and wheels, retard rollers, pinch rollers and the like. When the sheet is passed through these points, often under elevated temperatures, there is intimate contact between the pressure point and the sheet which can result in contamination of the device with components of the CF coating and have deleterious effects on the continued operation of the printer or copier.
• Simply increasing the amount of binder in the CF formulation may improve binding of the various CF components and thereby reduce contamination.
• an increase in binder levels typically results in a corresponding decrease in product performance characteristics, such as intensity.
• This invention provides an improved carbonless copy paper, and in particular an improved carbonless CF recording sheet which is capable of being printed on an electrostatic copier or printer without excessive contamination and without requiring excessive maintenance to enable continued operation of the printer or copier. It has been found that, in accordance with the invention, the binder portion of the CF coating can be increased without adversely affecting imaging properties.
• polyvinyl alcohol mixed with latex is used to improve binding of the pigments in the CF coating while avoiding film formation which can be detrimental to image intensity and speed of development.
• an improved binder based on PVA and starch prepared as a cooked pre-mix is used to provide improved binding of the CF coating without adversely affecting imaging properties. DESCRIPTION
• the recording sheet of the present invention may be used in any imaging system in which a color precursor is reacted with a developer to form an image. More particularly, it may be used in pressure-sensitive transfer recording systems, pressure- sensitive self-contained recording systems, and thermal or heat-sensitive recording systems.
• the recording sheet of the present invention may be used in a photosensitive recording system.
• Photosensitive compositions, photoinitiators, color formers, wall formers, encapsulation techniques and developer materials useful in photosensitive recording systems are described in U.S. Pat. Nos. 4,399,209; 4,772,530; and 4,772,541 are useful herein. These patents are incorporated herein by reference.
• the recording sheet includes a substrate having a front surface and a back surface.
• the substrate is typically paper but in certain applications it may be made of transparent polymeric materials such as polyethylene terephthalate, translucent substrates, opaque polymeric substrates such as Melinex 329 and Melinex 470 sold by ICI Americas, or polymer coated paper materials such as commercially available photographic papers and plain paper.
• the developer material is selected such that it reacts with the color precursor to produce a high density image.
• the color precursor is a substantially colorless electron donating compound of the type conventionally used in the pressure-sensitive recording art and the developer material is a solid particulate electron accepting compound.
• the developer can be selected from among the developers conventionally used in carbonless paper including acid clay, active clay, attapulgite, etc.; organic acids such as tannic acid, gallic acid, propylgallate; aromatic carboxylic acids such as benzoic acid, p-tert- butyl-benzoic acid, 4-methyl-3-nitro- benzoic acid, salicylic acid, 3-phenyl salicylic acid, 3- cyclohexyl salicylic acid, 3-tert-butyl-5-methyl salicylic acid, 3,5-ditert-butyl salicylic acid, 3-methyl-5-benzyl salicylic acid, 3-phenyl-5-( ⁇ , ⁇ -dimethylbenzyl)salicylic acid, 3- cyclohexyl-5-( ⁇ , ⁇ -dimethylbenzyl)salicylic acid, 3-( ⁇ , ⁇ -dimethylbenzyl)-5-methyl salicylic acid, 3,5-dicyclohexyl salicylic acid, 3,5-di-( ⁇ -methyl
• Preferred developer materials are phenolic resins, such as phenol-aldehyde resins e.g., p-phenyl-pjienolformaldehyde resin; phenol-acetylene resins, e.g., p-tert-butyl- phenoi-acetylene resin; polyvalent metallic salts thereof such as zinc modified phenol formaldehyde resin as disclosed in U.S. Pat. No. 3,732,120, and phenolic resins modified to include amounts of unsubstituted or substituted salicylic acids in a manner known in the art.
• phenol-aldehyde resins e.g., p-phenyl-pjienolformaldehyde resin
• phenol-acetylene resins e.g., p-tert-butyl- phenoi-acetylene resin
• polyvalent metallic salts thereof such as zinc modified phenol formaldehyde resin as disclosed in U.
• phenolic resin useful in the present invention is the product of oxidative coupling of substituted or unsubstituted phenols or bisphenols. Oxidative coupling may be catalyzed by various catalysts but a particularly desirable catalyst is the enzyme peroxidase.
• Particularly desirable developers are the resins described in commonly assigned U.S. Pat. No. 4,647,952, which is incorporated herein by reference, and more particularly the product of oxidative coupling of bisphenol A.
• Especially preferred developer materials are phenol-formaldehyde condensation products. More particularly, alkylphenolic resins and, still more particularly, metallated products of alkylphenolic resins are preferred.
• alkyl phenols are monosubstituted by an alkyl group which may contain 1 to 12 carbon atoms.
• alkyl phenols are ortho- or para- substituted ethylphenol, propylphenol, butylphenol, amyl- phenol, hexylphenol, heptylphenol, octylphenol, nonylphenol, t-butylphenol, t-octylphenol, etc.
• thermoplastic developer material which may be used within the scope of the present invention is a resin-like condensation product of a polyvalent metal salt, such as a zinc salt, and a phenol, a phenol-formaldehyde condensation product, or a phenol- salicylic acid-formaldehyde condensation product.
• a polyvalent metal salt such as a zinc salt
• phenolic developer resins are available from Schenectady Chemical Co. under the designations HRJ 2629, HRJ 2969, HRJ 4250 and HRJ 4542. The latter two products are reported to be a metallated condensation product of an ortho- or para-substituted alkylphenol, a substituted salicylic acid, and formaldehyde.
• a binder is used to improve the scuff resistance of the recording layer and to provide adequate adhesion between the coating and the substrate.
• the amount of binder used in the composition will vary depending upon the nature of the binder material. In accordance with the present invention, the amount of binder used is determined based on the amount necessary to securely anchor the components of the recording coating to the sheet in order to avoid contamination without adversely affecting imaging properties.
• the total binder content typically will fall within the range of about 2 to 30% and more typically about 8 to 20% based on solids.
• a binder used in the present invention is mixed with the developer resin to form a developer coating.
• the binder acts to enhance the surface strength of the coating as well as to adhere the coating to the substrate.
• a strong synthetic binder such as polyvinyl alcohol, is used to provide enhanced binding strength.
• Additional synthetic and/or natural binders can also be added. Synthetic binders are typically preferred because they are stronger than natural binders and the surface strength of the developer sheet can be maintained without affecting image development.
• Illustrative examples of other synthetic binders which can be used include polyvinyl acetate and copolymers thereof, styrene butadiene rubber (SBR), polystyrene, butadiene-styrene copolymers, polyvinylpyrrolidone, acrylic homo- or copolymers such as acrylic or methacrylic acids or lower alkyl esters thereof, e.g., ethyl acrylate, butyl acrylate and methyl methacrylate, acrylamide and the like.
• SBR styrene butadiene rubber
• acrylic homo- or copolymers such as acrylic or methacrylic acids or lower alkyl esters thereof, e.g., ethyl acrylate, butyl acrylate and methyl methacrylate, acrylamide and the like.
• Latex binders such as sytrenebutadiene latexes, carboxylated sytrenebutadiene latexes, acrylic latexes, and acrylonitrile latexes.
• Latex binders when present, typically fall within the range of about 2 to 10% and more typically 3 to 6% by dry weight of the coating composition.
• Genflo Latex 5100 is sold under the trade designation Genflo Latex 5100 from Omnova.
• binders are gum arabic, casein, sodium alginate, methyl cellulose, carboxy ethyl cellulose, dextrin, starch or modified starches, e.g., oxidized, hydrolyzed or hydroxyethylated starch, and the like.
• the microspheres used in the present invention are hollow spherical pigment particles made from a synthetic organic polymer or any inorganic shell- forming material such as glass or sodium silicate. Typically such microspheres have a diameter of approximately 0.3 ⁇ to 15 ⁇ and preferably about 1.0 micron. Such hollow synthetic organic pigment particles are known in the art and are commercially available from Rohm and Haas Corp.
• the microspheres provide a network of gas-filled voids in the developer layer. Furthermore, it is believed that the microspheres help to prevent the binder from forming a film on the surface of the sheet.
• One example of a commercially available microspheres that is useful in the present invention is sold under the trade designation HP-1055 from Rohm and Haas.
• Hollow polymer particles which are useful in this invention may be made in accordance with and having the properties disclosed in U.S. Pat. Nos. 3,784,391; 4,798,691; 4,908,271; 4,910,229; and 4,972,000; and Japanese Patent Applications 60/223873; 61/62510; 61/66710; 61 /86941; 62/127336: 62/156387; 01/185311 ; and 02/140272; U.S. Pat Nos. 4,427,836;4,469,825; ⁇ ,594,363; and 4,880,842.
• the disclosures therein related to the manufacture and composition of the hollow polymer particles are incorporated herein by reference.
• the preferred pigment has a soft compressible quality that yields a microscopic void under the applicalion of writing or marking pressure.
• the recording layer may also include in the coating solution a viscosity increasing additive, typically a water-soluble material, which significantly increases the
• thermoplastic developer material further optionally incorporated with the thermoplastic developer material is one or more dispersing agents (e.g., Dispex N-40, polymeric carboxylic acid from Allied Colloids, Inc.).
• dispersing agents e.g., Dispex N-40, polymeric carboxylic acid from Allied Colloids, Inc.
• Other commonly utilized additives such as anti-foaming agents, structured clays (e.g., Exsilon 87 and Ansilex 93 from Englehard Corp., as described in U.S.
• Patent 5,350,729 to Londo et al. optical whitening agents (e.g., Tinopal PT-150 from Ciba Geigy Corp.) and lubricants (e.g., Nopcote C-105HS calcium stearate dispersion from Henkel Corp.) may also be added in minor amounts.
• optical whitening agents e.g., Tinopal PT-150 from Ciba Geigy Corp.
• lubricants e.g., Nopcote C-105HS calcium stearate dispersion from Henkel Corp.
• the developer material is dispersed in a liquid, typically water, to form a resin dispersion, and binder material, microspheres, and optional additives are mixed into the dispersion.
• a liquid typically water
• binder material, microspheres, and optional additives are mixed into the dispersion.
• the dispersion is well mixed, it is coated onto the support by coating means known in the art. For example, a Meyer bar coater may be used.
• the developer layer is applied in an amount of about 1.0 to 2.0 pounds per 1700 sq. ft.
• the de eloper resin is used in an amount sufficient to react with a color precursor and form as image.
• the developer layer contains about 4 to 40%) developer and about 5 to 50 wt.% microspheres.
• the amount of developer resin used is about 10% to 25% and the amount of microspheres is about 7 to 20% based on dry weight.
• binder levels of the recording layer are increased such that the coatings can be run for extended periods of time on an electrostatic printer or copier without excessive contamination or downtime for maintenance.
• polyvinyl alcohol PVA
• the amount of PVA on a dry basis typically is between 2 and 12%, preferably between 4 and 9%.
• the polyvinyl alcohol is cooked with a starch to prepare a pre-mix which is then used to prepare a CF recording layer coating composition in accordance with the present invention.
• the amount of starch used typically is about 2 to 25%, preferably about 4 to 20% based on dry weight.
• One embodiment of the present invention is a developer sheet which minimizes contamination in electrostatic printers or copiers and yet also provides improved image intensity through one or a combination of mechanisms.
• the starch-PVA pre-mix prevents formation of a PVA barrier film which otherwise would interfere with imaging capabilities of the carbonless form.
• the starch-PVA pre-mix facilitates penetration of the color oil (from ruptured CB microcapsules) into the developer layer and into contact with the color developing resin, thereby forming an image.
• the present invention also provides a method for printing carbonless forms on an electrostatic printer or copier which comprises providing a recording sheet having a developer and a binder, wherein the binder comprises one or more synthetic binders, preferably a combination of polyvinyl alcohol and latex, and printing on the recording sheet with an electrostatic printer or copier.
• Carbonless forms printed in accordance with the present invention can be run sequentially for an extended period of time without causing contamination of the electrostatic printer or copier.
• the method of the invention avoids expensive printer downtime for cleaning typically required for electrostatic printing of conventional carbonless.
• the present invention is also directed to a process for electrostatically printing carbonless sheets and producing a carbonless formset.
• the carbonless formset contains a plurality of sheets, including at least a first substrate containing a coating of an encapsulated color former and a second substrate containing a second coating of a color developer.
• the first and second substrates are positioned such that the first and second coatings are juxtaposed.
• the second coating comprises a color developer in a binder matrix of polyvinyl alcohol and latex.
• Fo ⁇ nsets are produced by applying adhesive to the formset sheets after the sheets have been printed on the electrostatic copier or printer, such that the first and second substrates are collated as a set.
• Formsets of three plies or more can be prepared by providing one or more CFB sheets between the first (CB) and second (CF) substrates.
• the present invention is illustrated in more detail by the following non- limiting examples. As shov in the following table, recording sheets prepared in accordance with the present invention can successfully be processed on an electrostatic printer or copier without causing excessive contamination to the components of the device and yet still provide improved imaging capabilities.
• Developer coating compositions were prepared using the binder, developer resin, plastic pigment and other additives (combined mix) identified in Table 1. The three fo ⁇ nulations represent a prior art control and two formulations (YE and YC) representative of the present invention. In general, the developer coatings were prepared by adding, with mixing, the components in the order listed. The PVA was cooked at about 90° C for approximately 30 minutes before being added to the mix.
• compositions were formulated as aqueous dispersions at a solids content compatible with the applicable coating method, as is known in the art.
• the compositions were coated on a standard basestock according to conventional coating procedures. Imaging and processing properties of the samples were determined in accordance with the following test procedures.
• the coated specimens were also tested on a Xerox printer to determine the propensity of the samples to cause contamination in the printer.
• the specimens were processed through the printer and the point at which contamination was observed on the fuser roll pad was recorded as the run length. Accordingly, specimens having longer run lengths are less likely to cause contamination in the electrostatic printers.
• R is the average reflectance of the imaged area of the respective test
• p is the average reflectance of the unimaged area of the specimen.
• the samples produced in accordance with the invention provided significantly improved performance on the copier, improved intensity and approximately equivalent smudge compared to the prior art control samples.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Chemical & Material Sciences (AREA)
• Color Printing (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2000
  • 2000-07-24 EP EP00962004A patent/EP1204536A4/de not_active Withdrawn
  • 2000-07-24 AU AU73875/00A patent/AU7387500A/en not_active Abandoned
  • 2000-07-24 CA CA002382673A patent/CA2382673C/en not_active Expired - Fee Related
  • 2000-07-24 WO PCT/US2000/040467 patent/WO2001007265A1/en not_active Ceased

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