JPH06171210A - Pressure sensitive recording sheet and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a pressure sensitive recording sheet having an opaque coating sheet which has a closed property of information and its secrecy and can not be adhered after once peeled off, and a peeling property balanced with an adhesion property by a method wherein a surface of the opaque coating sheet on a contact side with a thermoplastic resin laminate layer is processed by mold releasing treatment. CONSTITUTION:In a pressure sensitive recording sheet 7, a pressure sensitive recording layer 4 and an opaque resin coating sheet 1 are integrated on a side surface of a base material 5 via a thermoplastic resin laminate layer 3. Then, a color coupler or a developer on both sides or one side is microcapsulated and respectively or mixedly applied to the pressure sensitive recording layer 4. In that case, a surface of the opaque coating sheet 1 on a contact side with the thermoplastic resin laminate layer 3 is processed by mold releasing treatment. That is, the mold reliesing processed opaque coating sheet 6 is formed by the opaque coating sheet 1 and a mold reliesing processed layer 2. Further, a silicone compound, a fluorine compound, or an interfacial active agent are used for the mold releasing treatment. Furthermore, melting extrusion and cladding are carried out in manufacturing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive recording sheet, and an opaque coating sheet on a single-form self-coloring type pressure-sensitive recording layer provided on a support through a thermoplastic resin laminate layer. Is a pressure-sensitive recording sheet having an internal color forming property, the opaque coating sheet has releasability, and is a type of recording sheet having non-exposure of recording, water resistance, chemical resistance, oil resistance, and scratch resistance. In particular, it is a pressure-sensitive recording sheet that can be used as a recording sheet for slips, correspondence, entertainment items, clean rooms, etc., which has excellent properties of preventing re-adhesion and retaining information.

[0002]

2. Description of the Related Art The pressure-sensitive recording layer used in the present invention is a self-coloring pressure-sensitive recording type, which is developed from so-called carbonless copying paper. Also called paper. Its composition is a process of applying a coating of microcapsules containing a colorless dye (hereinafter referred to as a color former) on a support, and electron-accepting properties of acid clay, phenolic resin, organic acid substances, etc. on the coating. Conveniently the process of applying a substance (hereinafter referred to as a color developer) and a manufacturing method by two-layer coating consisting of two steps (including those in which the coating order is reversed), the above two components, or any one component Manufacturing method by microencapsulation, uniform mixing, and single layer coating (Japanese Patent Publication No.
No. 7-16096) is known. In such a self-coloring pressure-sensitive recording sheet, a color developing agent and a color developing agent are present in the vicinity, so a printed image with a high color density is easily obtained, but unintentional unintentional due to friction during manufacturing or handling. There is a problem that colored stains are likely to occur.

The self-coloring pressure-sensitive recording sheet is destined to satisfy both the practically required coloring performance and the suppression of unnecessary coloring stains under the conditions under which it is used. Efforts are being made to satisfy both conflicting properties of dirt. Further, in the self-coloring type pressure-sensitive recording sheet, the pressure-sensitive recorded information is inevitably exposed to the public and highly open.
If you wanted to hide the information content, you had to put it in a separate bag.

Up to now, for example, a method of providing a laminate layer by a vacuum adhesion method on a recording layer of a self-coloring pressure-sensitive recording sheet (Japanese Patent Publication No. Sho 49-10857) or a recording having a plastic layer by a melt lamination method. Known examples include a sheet (Japanese Utility Model Publication No. 52-149709) and a release layer provided on these protective layers. However, in reality, when a protective layer is provided by fusion lamination or lamination, unnecessary color stains can be prevented, but basically it is premised that the pressure-sensitive recording portion is exposed. The issue of record secrecy could not be resolved. In addition, a heat-sealing or thermoplastic resin coating layer is provided on the recording layer of a self-coloring type pressure-sensitive recording sheet, and the back surface is overlaid with an opaque coating sheet coated with a hot-melt type or thermoplastic type heat-sealing adhesive. , A method of integrating by hot pressing (Japanese Utility Model Laid-Open No. 2-2173, Japanese Utility Model Laid-Open No. 3-116974)
No.), but if they are hot pressed enough to be integrated, color fog on the pressure-sensitive recording layer may be caused, resulting in loss of commercial value.
Alternatively, there is no choice but to use a resin having an adhesive force much weaker than the adhesive force and to perform integration with the adhesive force with a light press. Although this type of pressure-sensitive recording sheet has the concealment of the recording, it can be easily re-adhered by simply re-pressing it, so that the confidentiality of the recording is low.

The present applicants have previously prepared a pressure-sensitive recording layer in which a color-forming agent or a color-developing agent, both or one of which has been microencapsulated, is individually laminated or mixed on one surface of a support. Using a pressure-sensitive recording sheet in which the opaque coating sheet and the opaque coating sheet are integrated via a thermoplastic resin laminate layer, the adhesive strength between the pressure-sensitive recording layer and the thermoplastic resin laminate layer is increased, and the opaque coating sheet and the thermoplastic resin laminate sheet are laminated. It was found that these problems could be solved by weakening the adhesive strength with the layer, but there was a problem that the releasability of the opaque coated sheet was likely to vary. this is,
It is considered that this is based on the reason that the opaque coated sheet is often formed from paper made of pulp, so that the surface in contact with the thermoplastic resin laminate layer is not uniform. In particular, when the surface of the opaque coated sheet that is in contact with the thermoplastic resin laminate layer is paper whose main component is pulp,
Even if the average value of the 0 ° peeling test is such that the adhesive strength falls within the allowable range, there is a portion that exceeds the allowable adhesive strength, although it is considered microscopically to be the effect of the unevenness of the pulp fiber.
Although such a micro excessive adhesion strength hardly affects the peeling itself of the opaque coating sheet, it may cause color development in the pressure-sensitive recording layer and is not preferable as a recording sheet. If the press pressure at the time of lamination is reduced in order to avoid such a microscopic excessive adhesion, the adhesiveness itself of the opaque coating sheet deteriorates, causing a fatal defect as a product such as peeling of the top paper.

The adhesive strength with the thermoplastic resin laminate layer is a relative comparison between the pressure sensitive recording layer side and the opaque coating sheet side, but preferably the adhesive strength of the thermoplastic resin laminate layer on the pressure sensitive recording layer side. Is 100gf / 15m in a 180 ° peel test on a Tensilon universal tensile tester.
It is preferable that the adhesive strength (peeling strength) is m or more.
If the adhesive strength of the thermoplastic resin laminate layer is less than this range, peeling trouble of the thermoplastic resin laminate layer may occur during recording, transportation, and the like. Further, if it is more than this range, even if the thermoplastic resin laminate layer is forcibly peeled off, the pressure-sensitive recording layer develops color, so that the adhesive strength is sufficient.

In principle, the opaque coating sheet can be peeled off if the adhesive strength with the thermoplastic resin laminate layer on the side of the opaque coating sheet is less than the adhesive strength between the thermoplastic resin laminate layer and the pressure-sensitive recording layer, but too much. If the adhesive strength is too close, the thermoplastic resin laminate layer may float (partially peel off) from the pressure-sensitive recording layer, or the pressure-sensitive recording layer may develop color or become opaque when the opaque coating sheet is peeled off. Depending on the thickness of the cover sheet, the opaque cover sheet may be broken when peeled off. Such troubles differ in the adhesive strength range generated depending on the thickness and type of the opaque coating sheet, the thickness of the thermoplastic resin laminate layer, or the color developability of the pressure-sensitive recording layer.
It is preferable that the adhesive strength (peeling strength) is smaller than 80 gf / 15 mm in the 0 ° peeling test.

In general, when a thermoplastic resin laminate is carried out, the adherend and the polyolefin resin are adhered to each other by a physical anchor effect or by a weak hydrogen bond. Naturally, it is possible to improve the adhesiveness by increasing the ratio of chemical bonds between the polyolefin resin and the adherend by undercoating the adherend or using a reactive polyolefin resin. The adhesive strength between the thermoplastic resin laminate layer and the adherend has such an anchor effect,
It can be strengthened or weakened by changing the ratio of hydrogen bonds and chemical bonds. That is, in order to increase the adhesive strength, the resin temperature and the adherend temperature during melt lamination are increased, the adherend surface is roughened, the press pressure during lamination is increased to enhance the anchor effect, and Corona treatment, flame treatment, UV irradiation,
This is achieved by performing a pretreatment such as ozone treatment to introduce a polar group and increasing the proportion of hydrogen bonds.

On the contrary, in order to weaken the adhesive strength, the resin temperature and the adherend temperature at the time of melt lamination are lowered, the adherend surface is smoothed, and the press pressure at the time of lamination is lowered to lower the anchor effect. Or, to reduce the proportion of polar groups without pretreatment such as corona treatment, flame treatment, ultraviolet irradiation, ozone treatment on the adherend, or increase the water content if it is a porous substance such as paper. It is possible to reduce the bonding strength by reducing the proportion of hydrogen bonds that contribute to adhesion.

However, from the viewpoint of the production process, the resin temperature and the press pressure at the time of melt lamination are determined by the pressure sensitive recording layer side where the adhesive strength is desired to be increased and the opaque coated sheet side where the adhesive strength is relatively low. It is impossible to make a large change at the same time, and basically, the resin temperature and the press pressure have to be set higher so that the adhesive strength on the pressure-sensitive recording layer side is not too small. Under such conditions, the adhesive strength will be considerably high even if the opaque coating sheet side is not subjected to pretreatment such as corona treatment, and peeling of the opaque coating sheet will be very heavy, or pressure-sensitive recording will occur when the opaque coating sheet is peeled off. There was a problem that the layers developed color.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pressure-sensitive recording sheet having an opaque coating sheet with the information non-disclosure without sacrificing its original coloring property. The peeled opaque coated sheet has a confidentiality property that prevents re-adhesion, and the adhesiveness of the thermoplastic resin laminate layer is good in actual use, prevents recording alteration and contamination, and balances peelability and adhesiveness. An object of the present invention is to provide a pressure-sensitive recording sheet having a smooth opaque cover sheet.

[0012]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found the following solution. That is, a pressure-sensitive recording layer and an opaque coating sheet, each of which is formed by laminating or mixing a color former or a color developer in which both or one of them is microencapsulated on one side of a support, respectively, are mixed with a thermoplastic resin. A pressure-sensitive recording sheet integrated with a laminate layer, characterized in that the surface of the opaque coating sheet on the side in contact with the thermoplastic resin laminate layer is subjected to release treatment. It is an invention. It is preferable that the releasing treatment herein is performed by substantially containing one or more kinds of compounds selected from a silicone compound, a fluorine compound and a surfactant on the surface of the opaque coated sheet or in the opaque coated sheet. To produce the product of the present invention, a pressure-sensitive recording layer in which a color-developing agent or a color-developing agent, both or one of which is microencapsulated, is singly laminated or mixed on one surface of a support. The pressure-sensitive recording layer and the release-treated layer are made to face each other, and a thermoplastic resin is melt-extruded in the middle of the sheet. This is done by bonding a sheet having a recording layer and an opaque coating sheet.

The details of the present invention will be described below. In the pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque coating sheet can be integrated during melt extrusion of the thermoplastic resin laminate layer, and the adhesive strength (peel strength) of the thermoplastic resin laminate layer can be recorded by pressure-sensitive recording. By changing the layer side and the opaque coating sheet side, it is possible to peel off the opaque coating sheet having a relatively weak adhesive strength with the thermoplastic resin laminate layer.

In the present invention, any method may be used for the release treatment of the opaque coating sheet, and the following methods are available, for example. That is, on one surface of the opaque coated sheet, a silicone compound, a fluorine compound, an aliphatic hydrocarbon lubricant, a higher aliphatic alcohol lubricant, a higher fatty acid lubricant, a fatty acid amide lubricant, a metal soap lubricant, a fatty acid ester lubricant, Cationic surface active agent, nonionic surface active agent, anionic surface active agent, amphoteric surface active agent or the like is applied to the opaque coating sheet, or internally added,
It is used after being impregnated, and if necessary dried and cured. It is possible to use other binder components together with these release agents, but it is preferable to use a binder that does not exhibit substantial tackiness or adhesiveness by heating.

Among the release agents used in the present invention, the silicone compound includes an acryloyl group, a methacryloyl group, a vinyl group, an epoxy group, a vinylamide group, a hydrosilyl group, a silanol group, a diazo group, an acetylene group at a molecular end or a side chain, A silicone resin (mainly polydialkylsiloxane) having a functional group selected from a thiol group and a phenol group or bonded to these functional groups via an alkylene group or an alkyleneoxy group is preferable. . These silicone resins may be further modified with long-chain alkyl, polyether, carbinol, amine, epoxy, carboxyl, mercapto and methacryl.

Other releasing agents include mineral oil-based liquid paraffin, fatty acid-based stearic acid, oleic acid, etc.
Natural oils and fats animal and vegetable oils, natural waxes, fatty acid ester-based ethylene glycol fatty acid esters, sorbitol fatty acid esters, polyoxyethylene fatty acid esters, alcohol-based polyoxyalkylene glycols, glycols, polyoxyethylene higher alcohol ethers, etc., Amide-based polyoxyethylene alkylene, amide resin, etc., phosphate ester-based polyoxyalkylene phosphate, etc., metal soap-based calcium stearate, zinc stearate, sodium oleate, etc., fluorine-based polytetraethylene fluoroethylene , Perfluoroalkyl alkoxylates, perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl quaternary ammonium halogens Compound, perfluoroalkyl polyoxyethylene ethanols, and fluorinated alkyl esters, talc as an inorganic systems. The release agent can be applied by emulsion type, solvent type, solventless type, mixed melt extrusion type, etc., and the curing mechanism is solvent evaporation type, condensation type, addition type, cross-linking type, ring-opening polymerization type, ultraviolet ray. Curing reactions such as irradiation type and electron beam irradiation type are possible.

As the surfactant used as the release agent,
Polyoxyethylene polyoxypropylene block polymer, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, sorbitan acid fatty acid ester, polyoxyethylene sorbitan acid fatty acid ester, fatty acid monoglyceride, polyethylene glycol fatty acid ester, polyoxyethylene alkylamine, etc. Nonionic surfactant, various fatty acid salts such as oleic acid type and stearic acid type, fatty acid soap, alkyl sulfate ester, alkylbenzene sulfonate, alkylnaphthalene sulfonate, dialkyl sulfosuccinate, higher alcohol sulfate ester salt, α- Anionic surfactants such as olefin sulfonate and alkyl phosphate, alkyl trimethyl ammonium chloride, alkyl benzyl methyl ester Ammonium chloride, cationic surface active agents, such as other quaternary ammonium salts,
And amphoteric surfactants such as sodium lauryl aminopropionate and lauryl methyl betaine.

In the present invention, examples of the binder component include the following substances. As natural and synthetic polymers, modified starch compounds such as starch and oxidized starch, alginic acid compounds such as sodium alginate and propylene glycol alginate, casein,
Gelatin, chitin, chitosan, modified cellulose compound,
Fully or partially saponified polyvinyl alcohol polymaleic acid copolymer, polyacrylamide, water-soluble alkyd resin, styrene / maleic anhydride copolymer, styrene / butadiene copolymer, butadiene / methacrylate copolymer, acrylonitrile / butadiene / Synthetic polymers such as acrylic acid latex and the like may be used alone or in combination, without solvent, or dissolved or dispersed in a solvent.

The coating amount of these release agents varies depending on the smoothness and air permeability of the opaque covering sheet to be used, and the type, thickness and processing conditions of the thermoplastic resin laminate layer.
It is preferable that the substantial amount of the release agent applied is 0.1 g / m ² or more. In addition to the application to the opaque coating sheet, a method of performing a mold release treatment on the opaque coating sheet by impregnation, or a release agent is internally added at the stage of manufacturing the opaque coating sheet, and the release agent is added in the opaque coating sheet. There is also a method of immobilizing.

When a pressure-sensitive recording sheet in which the thickness of the thermoplastic resin laminate layer is within a certain range and the color-developing property of the pressure-sensitive recording layer is high, the opaque coating sheet almost disperses and absorbs the writing pressure. Since it transmits without pressure, high color density can be obtained at the time of pressure sensitive recording, and the gloss, scratch resistance, and abrasion resistance of the printing surface are excellent, and also because an opaque coating sheet is provided on the thermoplastic resin laminate layer. The pressure-sensitive recorded information can be handled without being exposed and exposed to the outside, and the opaque coated sheet can be peeled off as necessary to read the pressure-sensitive recorded information inside. Further, the information once disclosed has a characteristic that it cannot be hidden again (preventing re-adhesion).

As the resin constituting the thermoplastic resin laminate layer, polyethylene (low density, medium density, high density, linear low density polyethylene), polypropylene, polytrimethylpentene, polybutene, ethylene vinyl acetate copolymer, ethylene ethyl General-purpose melt extrusion resins such as acrylate copolymer, ethylene acrylic acid copolymer, ethylene methyl acrylate copolymer, ethylene vinyl alcohol copolymer, ethylene methacrylic acid copolymer and its salts, vinyl chloride, vinylidene chloride They can be used alone or as a mixture. The mixing method is not particularly limited, and any method can be used. For example, an extruder for kneader, a heating kneading roll, a Banbury mixer, a predetermined amount of a polyolefin resin using a kneader, and if necessary, various additives (release agent, slip agent, pigment, antioxidant, neutralizing agent) Agent, etc.) and melt-mixed, and then crushing and pelletizing the mixture, or by directly charging the mixture into an extruder in a so-called simple blend state and extrusion-coating, or when polymerizing one of the polyolefin resins. A method using a mixed resin obtained by copolymerizing other components can be used.

Further, by setting the thickness of the thermoplastic resin laminate layer in the range of 10 to 50 μm, the glossiness, scratch resistance, and gloss of the printed surface can be obtained without lowering the color developability of the pressure-sensitive recording layer.
Not only does it improve abrasion resistance, but it also functions as a release layer that is released from the opaque coated sheet. When the thickness of the thermoplastic resin laminate layer is smaller than this range, when the opaque coating sheet is peeled off, a laminate layer floating occurs in which the thermoplastic resin laminate layer is peeled off from the pressure-sensitive recording layer, or
The background may be fogged on the pressure-sensitive recording layer, making it difficult to read the record. When the thickness of the thermoplastic resin laminate layer is thicker than this range, the recording density is lowered when pressure-sensitive printing is performed, which is not preferable as a recording sheet.

In order to integrate the pressure-sensitive recording layer and the opaque coating sheet with a thermoplastic resin laminate, a general laminator such as a melt extrusion die, a T die or a multi-layer simultaneous extrusion die can be used. As a pretreatment for melt extrusion, a known treatment for improving adhesion such as corona treatment or frame treatment may be performed on the pressure-sensitive recording layer or the opaque coating sheet. As a matter of course, the adhesiveness and the releasability can be controlled by changing the degree of surface treatment of the pressure-sensitive recording layer and the opaque coating sheet. At the time of laminating by melt extrusion, either the support having a pressure-sensitive recording layer or the opaque coating sheet may be positioned on the cooling roll side or the press roll side, but a pressure-sensitive recording layer having particularly high color-developing sensitivity is provided. When used, it is preferable to use an opaque cover sheet on the press roll side.

The resin forming these thermoplastic resin laminate layers can contain organic or inorganic pigments, organic dyes, and dye amounts, for example, kaolin, calcined kaolin, talc, pyrophyllite, diatomaceous earth, carbonic acid. calcium,
Examples thereof include aluminum hydroxide, magnesium hydroxide, magnesium carbonate, titanium oxide, barium carbonate, urea-formalin resin, plastic beads such as styrene, ultramarine blue, crystal violet, and leuco dye coloring material.

Between the pressure-sensitive recording layer and the thermoplastic resin laminate layer, if necessary, polyvinyl alcohol, gelatin, polyacrylic acid and its salts, casein, starch, various latexes such as rubber latex, etc. for improving adhesion. The aqueous polymer intermediate layer can be provided in a coating amount range that does not reduce the pressure-sensitive recording sensitivity.

As the support and the opaque coating sheet used in the pressure-sensitive recording sheet of the present invention, general paper such as glassine paper, high-quality paper, art paper, coated paper, cast paper and the like can be used, wood pulp, Raw materials commonly used in papermaking, such as synthetic pulp, fillers, sizing agents, paper-strengthening agents, and dyes, can be used as necessary.
Further, plastic sheets such as polyethylene, polypropylene, polyethylene terephthalate, polyamide, polyvinyl chloride, polyvinylidene chloride, and polymethylpentene, and synthetic papers and nonwoven fabrics made of these synthetic fibers,
Or laminated paper with synthetic resin laminated on one side, metal foil, or laminated product of metal foil and paper, vapor-deposited paper, opaque sheet subjected to hologram treatment, laminated product with synthetic resin film, mica paper, glass Paper etc. can also be used. These supports can be made opaque with inorganic or organic pigments, inks, toners and the like. In addition, a pressure-sensitive recording layer or a part thereof (developing agent layer or color-developing agent layer), a heat-sensitive layer, a magnetic recording layer, or a printing layer is provided on the non-bonded surface of the opaque coating sheet or the surface having no pressure-sensitive recording layer. It can also be provided.

In the method of the present invention, the base paper based on natural pulp including waste paper pulp, which is advantageously used, includes
Various polymer compounds and additives can be contained. For example, starch, starch derivatives (cationized starch, phosphate esterified starch, oxidized starch, etc.), polyacrylamide, polyvinyl alcohol, polyvinyl alcohol derivatives (completely saponified, partially saponified,
Carboxy-modified, cation-modified, other various modified polyvinyl alcohol), gelatin (alkali-treated, acid-treated, various modified gelatin), etc., dry paper strength enhancer, star gum, alginic acid derivatives and other natural polymer polysaccharides, higher fatty acid metal salts , Rosin derivatives, dialkyl ketones, alkenyl or alkyl succinic anhydrides, epoxidized higher fatty acid amides, organic fluoro compounds, dialkyl ketene dimer emulsions and other sizing agents, polyamide polyamine epichlorohydrin resins, melamine resins, urea resins, epoxidized polyamide resins Wet paper strength enhancer, stabilizer, pigment, dye, antioxidant, optical brightener, various latex, etc.
Inorganic electrolyte (sodium chloride, sodium sulfate, sodium phosphate, calcium chloride, lithium chloride, magnesium chloride, magnesium sulfate, barium chloride, etc.), pH
A modifier, a fixing agent such as a sulfuric acid band and aluminum chloride, a filler such as calcium carbonate, kaolin, talc, and clay, and an additive such as an organic conductive agent may be appropriately combined and contained. These contents may be dispersed in the pulp slurry at the paper making stage, may be added at the tab size after paper making, and the solution may be applied by various coaters. However, in all cases the concentration of residual surfactant must be below 800 ppm.

The pressure-sensitive recording layer that can be used in the present invention is not particularly limited, and any conventionally known one can be used. For example, a method of microencapsulation, a wall material of the microcapsule, a color former or an oil dissolving the color former, a color developer, an electron beam curable resin, a microcapsule protective agent, or the like. Examples of the microencapsulation method include a coacervation method (US Pat. No. 2,800,458), an interfacial polymerization method (Japanese Patent Publication No. 47-1763, etc.), an in situ polymerization method (Japanese Patent Publication No. 51-9079, etc.). Etc. can be used.

Polyurethane, polyurea, epoxy resin, urea / formalin resin, melamine / formalin resin and the like can be used as the wall material of the microcapsule.

As the color former, triallylmethane compounds, diarylmethane compounds, xanthene compounds,
A thiazine-based compound, a spiropyran-based compound, or the like can be used, and is not particularly limited as long as it is generally used for pressure-sensitive recording materials and heat-sensitive recording materials.

As the oil for dissolving the color former, aromatic synthetic oils such as diarylalkane series, alkylnaphthalene series, alkylated biphenyls, hydrogenated terphenyls, aliphatic synthesis such as kerosene, naphtha, paraffin oil and chlorinated paraffins are used. Oils, cottonseed oil, soybean oil, vegetable oils such as flaxseed oil and the like can be used.

As the protective agent for the microcapsules, cellulose powder, starch particles, talc, calcined kaolin, calcium carbonate and the like can be used.

Examples of developers include clays (eg, acid clay, attapulgite, etc.), organic acids (eg, aromatic carboxy compounds such as salicylic acid, or metal salts thereof), mixtures of organic acids and metal compounds, An acidic polymer (for example, phenol-formaldehyde resin, salicylic acid-based resin, or a metal salt thereof) or the like can be used.

In the present invention, as the binder used for forming the pressure-sensitive recording layer, starch, cellulose derivatives such as hydroxyethyl cellulose, methyl cellulose, ethyl cellulose and carboxymethyl cellulose, proteins such as casein and gelatin, oxidized starch and ester compounds. Aqueous natural polymer compounds such as saccharose such as starch, polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic acid ester / Methacrylic acid terpolymer, styrene /
Water-soluble synthetic polymer compounds such as alkali salts of maleic anhydride copolymers, latex, polyacrylamide, styrene / maleic anhydride copolymers, latexes, water-soluble alkali salts of ethylene / maleic anhydride copolymers, etc. Polymer, polyvinyl acetate, polyurethane, polyacrylic acid ester, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate /
Butadiene copolymer, acrylonitrile / butadiene /
Examples thereof include latex such as acrylic acid copolymer and ethylene / vinyl acetate copolymer.

Pigments used in the pressure-sensitive recording layer or the thermoplastic resin laminate layer include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide and aluminum hydroxide. , Urea-formalin resin and the like.

In addition, zinc stearate as an auxiliary agent,
Waxes such as higher fatty acid metal salts such as calcium stearate, paraffin, oxidized paraffin, polyethylene, oxidized polyethylene, stearamide, castor wax, etc., dispersant such as sodium dioctylsulfosuccinate, sulfonic acid modified polyvinyl alcohol, benzophenone type, An ultraviolet absorber such as a benzotriazole type, a surfactant, a fluorescent dye and the like are added as necessary.

In the pressure-sensitive recording sheet of the present invention, the method for forming the pressure-sensitive recording layer includes blade coating method, air knife coating method, gravure coating method, roll coating coating method,
Known coating methods such as a bar coating method and a drop curtain coating method can be used. The pressure-sensitive recording layer is preferably smoothed.

Further, a back coat is applied to prevent curling, a conductive treatment is applied to prevent jamming, and an undercoat layer is provided between the support and the pressure sensitive recording layer. Various known techniques in 1) can be added as necessary.

Further, as a constitution of the present invention, calcium carbonate, talc, silica, clay, barium sulfate, magnesium carbonate, magnesium silicate, between the support and the pressure-sensitive recording layer are used in order to obtain a high color density. Inorganic pigments such as lead sulfate, lead white, zinc white, zinc sulfide, satin white, titanium oxide, antimony oxide, mica, bentonite, calcium silicate, gypsum, aluminum hydroxide, or polystyrene, polyvinyltoluene, styrene / divinylbenzene There is no problem in providing an undercoat layer containing fine organic pigments such as polymers, polymethylmethacrylate, urea / formaldehyde polymers, and polyethylene.

The pressure-sensitive recording sheet of the present invention is used for pressure-sensitive recording on the surface, the pressure-sensitive recording surface, the surface of a thermoplastic resin laminate layer, the front surface or the back surface of an opaque coating sheet, or the back surface of the pressure-sensitive recording sheet. A color former layer or a developer layer or both, a protective coating layer, a peeling layer, a printing layer, a tint block printing layer, a toner receiving layer, an ink receiving layer, a heat-sensitive recording layer, a writing layer, a magnetic recording layer, etc. Alternatively, they can be provided at the same time. Further, the pressure-sensitive recording sheet of the present invention can be used as a series of copy sheets in combination with other pressure-sensitive recording sheet, back carbon copying sheet, adhesive sheet, printing sheet, transparent film and the like. There is no problem in processing a part or all of the recording sheet of the present invention such as die cutting, separating a part of the opaque coating sheet, processing perforations and printer feed holes.

[0041]

In the pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque coating sheet are integrated by the thermoplastic resin laminate layer, and the pressure-sensitive recording layer and the thermoplastic resin laminate layer are firmly adhered. Since the opaque coating sheet is peeled off, it is weakly adhered to the thermoplastic resin laminate layer, and the opaque coating sheet is separated with a light force from the support having the thermoplastic resin laminate layer and the pressure sensitive recording layer. Can be peeled off. Once the opaque coated sheet is separated from the thermoplastic resin laminate layer, the thermoplastic resin laminate layer is already cooled and solidified, so that it cannot be easily re-bonded. Since the thermoplastic resin laminate layer transmits the writing pressure with almost no dispersion and absorption, a high color density can be obtained at the time of pressure-sensitive recording, and the printed surface has excellent gloss, scratch resistance, and abrasion resistance. Since it has a thermoplastic resin laminate layer and an opaque cover sheet, the pressure-sensitive recorded information can be handled without being exposed or exposed to the outside, and the opaque cover sheet can be peeled off as necessary to make the inside sense. You can read the pressure-recorded information. Furthermore, for the reasons stated above, the information once disclosed is
It has a feature that it cannot be hidden again (anti-redeposition property).

[0042]

The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples.
All parts and% shown below are based on weight. Also,
Unless otherwise noted, the value indicating the smear amount is the smear amount after drying.

Example 1 As the pressure-sensitive recording paper, a commercially available high-sensitive self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diaself, MCD N130, basis weight 130 g / m ² ) was used. As the opaque coated sheet, a single-sided cast paper having a basis weight of 70 g / m ² was used, and a silicone resin emulsion (X-52-151, manufactured by Shin-Etsu Chemical Co., Ltd., 3% PM 6A / B as a catalyst) was used as a release agent on the non-cast surface. 1) in a solid content of 1 g / m ² and then dried by heating. Corona treatment was applied to the pressure-sensitive recording surface, and low density polyethylene (density: 0.918 g / cc, M was used as a thermoplastic resin laminate layer using a melt extrusion die.
FR: 12g / 10 minutes) and high density polyethylene (density:
0.955 g / cc, MFR: 37 g / 10 min) of an equal amount mixture of 15 g / m ² press linear pressure 28 kg
Melt-extruded at a pressure of 1 / cm, and the pressure-sensitive recording layer and the release-treated surface of the opaque coating sheet are bonded as a bonding surface,
A target pressure-sensitive recording sheet was obtained.

Example 2 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. Example 1 as an opaque cover sheet
The same single-sided cast paper is used as the release agent on the non-cast surface as a fluorine compound (3M, Florard FC
170C) 2% trimethylolpropane triacrylate (Ciba Geigy Photo Initiator Irgacure 65
1 (containing 5%) was applied at a rate of ² g / m ² and cured by irradiation with ultraviolet rays. Corona treatment was applied to the pressure-sensitive recording surface, and low-density polyethylene (density: 0.918 g / cc, MF was used as a thermoplastic resin laminate layer using a melt extrusion die.
R: 12 g / 10 minutes) and polypropylene (density: 0.9
(05 g / cc, MFR: 15 g / 10 min), an equal amount mixture of 15 g / m ² and a press linear pressure of 28 kg / cm 2.
Was melt-extruded, and the pressure-sensitive recording layer and the release-treated surface of the opaque coating sheet were bonded together as a bonding surface to obtain a target pressure-sensitive recording sheet.

Example 3 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. Example 1 as an opaque cover sheet
2 g of polyvinyl alcohol containing 5% of a cationic surfactant (manufactured by Nippon Emulsifier, Newcol 291M) as a release agent on the non-cast surface using the same single-sided cast paper
It was applied at a ratio of / m ² and dried by heating. The pressure-sensitive recording surface is subjected to corona treatment, and a low density polyethylene (density: 0.
920 g / cc, MFR: 10 g / 10 min) and high-density polyethylene (density: 0.955 g / cc, MFR: 25
(g / 10 minutes), and an equivalent mixture is melt-extruded at a press linear pressure of 28 kg / cm so as to have a pressure of 15 g / m ^2, and the pressure-sensitive recording layer and the release-treated surface of the opaque coating sheet are bonded as a bonding surface, A target pressure-sensitive recording sheet was obtained.

Example 4 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. Example 1 as an opaque cover sheet
2 g / m ^{2 of} polyvinyl alcohol containing 2% of a nonionic surfactant (manufactured by Sanyo Kasei Co., Ltd., Nonipol 100) as a release agent on the non-cast surface using the same single-sided cast paper
Was applied and heated and dried. Corona treatment was applied to the pressure-sensitive recording surface, and low-density polyethylene (density: 0.918 was used as a thermoplastic resin laminate layer using a melt extrusion die.
g / cc, MFR: 12 g / 10 minutes) and high-density polyethylene (density: 0.955 g / cc, MFR: 37 g / 1
0 min) 3: 1 weight ratio mixture was melt extruded at a press linear pressure of 28 kg / cm so as to be 15 g / m ^2, and the pressure-sensitive recording layer and the opaque coating sheet were pasted together as the pasting surface. A desired pressure-sensitive recording sheet was obtained.

Example 5 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. Example 1 as an opaque cover sheet
Using a single-sided cast paper similar to that described above, polyvinyl alcohol containing 5% of zinc stearate as a release agent was applied to the non-cast surface at a rate of ² g / m ² , and dried by heating. Corona treatment is applied to the pressure-sensitive recording surface, and low-density polyethylene (density: 0.918 g / cc, MFR: 12 g / 10 minutes) and polypropylene (density: 0.900 g / cc, MFR:
15 g / 10 min) in a weight ratio of 1: 2 mixture to 15 g / m ²
So as to achieve a pressure linear pressure of 28 kg / cm, and the pressure-sensitive recording layer and the release-treated surface of the opaque coating sheet were bonded together as a bonding surface to obtain a target pressure-sensitive recording sheet.

Example 6 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. Example 1 as an opaque cover sheet
Using a single-sided cast paper similar to the above, a fluorine compound (Florard FC72 manufactured by 3M Co., Ltd.) is used as a release agent on the non-cast surface.
1) was applied at a rate of 1 g / m ² and dried by heating. Corona treatment was applied to the pressure-sensitive recording surface, and polypropylene (density: 0.900 g / cc, MFR: 15 g / 10 minutes) was pressed with a melt extrusion die as a thermoplastic resin laminate layer to a press line of 18 g / m ^2. The composition was melt-extruded at a pressure of 28 kg / cm, and the release-treated surface of the pressure-sensitive recording layer and the opaque coating sheet were bonded together as a bonding surface to obtain a target pressure-sensitive recording sheet.

Example 7 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. As the opaque coating sheet, a commercially available lower sheet of pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, N40 under NCR) was used, and a radiation-curable silicone resin (X62-7192, manufactured by Shin-Etsu Chemical Co., Ltd., 5%) as a release agent on the non-recording surface. Photoinitiator manufactured by Ciba Geigy Inc., including Irgacure 651)
It was applied at a rate of g / m ² and cured by ultraviolet irradiation. The pressure-sensitive recording surface is subjected to corona treatment, and a polypropylene (density:
0.900 g / cc, MFR: 15 g / 10 min) 18
It was melt-extruded at a press linear pressure of 28 kg / cm so that the pressure was g / m ^2, and the release-treated surface of the pressure-sensitive recording layer and the opaque coated sheet were bonded as the bonding surface to obtain the target pressure-sensitive recording sheet.

Comparative Example 1 As the pressure-sensitive recording paper, a commercially available high-sensitivity self-coloring type pressure-sensitive recording paper similar to that of Example 1 was used. Corona treatment was applied to the pressure-sensitive recording surface, and low density polyethylene (density: 0.918 g was used as a thermoplastic resin laminate layer using a melt extrusion die.
/ Cc, MFR: 12 g / 10 minutes) and high-density polyethylene (density: 0.955 g / cc, MFR: 37 g / 10
Min) was melt-extruded at a press linear pressure of 28 kg / cm so that the mixture became 10 g / m ² . Further, the non-cast surface of the opaque coated sheet (one-sided cast paper, basis weight 70 g / m ² ) was also subjected to corona treatment, and a thermoplastic resin laminate layer similar to that used for pressure-sensitive recording paper was provided. The thermoplastic resin laminate layers provided on the pressure-sensitive recording layer and the opaque coating sheet were faced to each other and heat-pressed to be integrated to obtain an intended pressure-sensitive recording sheet.

Comparative Example 2 As the pressure-sensitive recording paper, the same self-coloring type pressure-sensitive recording paper as in Example 1 was used. Example 1 as an opaque cover sheet
The same single-sided cast paper was used, and the non-cast surface was used without peeling treatment. Corona treatment was applied to the pressure-sensitive recording surface, and low-density polyethylene (density: 0.918 g / c was used as a thermoplastic resin laminate layer using a melt extrusion die.
c, MFR: 12 g / 10 minutes) and high-density polyethylene (density: 0.955 g / cc, MFR: 37 g / 10
Min) was melt-extruded at a press linear pressure of 28 kg / cm to a pressure of 15 g / m ^2, and the pressure-sensitive recording layer and the opaque coating sheet were attached at the same time to obtain the target pressure-sensitive recording sheet.

[Coloring property] The color density of each pressure-sensitive recording sheet was measured by an impact printer after overlaying another sheet of pressure-sensitive upper paper (CBN50, NCR upper paper, manufactured by Mitsubishi Paper Mills) on the opaque coating sheet. Printing was performed by applying a constant weight, the opaque coating sheet was then peeled off to expose the color printed surface, and the color density was measured with a Macbeth reflection densitometer. Based on the color density of the self-coloring type pressure-sensitive recording paper before lamination, the relative value was 95% or more, excellent, 85% or more and less than 90%, and less than 85% inferior.

[Background fog] For the background fog of each pressure-sensitive recording sheet, the opaque coating sheet was peeled off to expose the thermoplastic resin laminate layer, and the optical density of the background was measured by a Macbeth reflection densitometer. Based on the optical density of the background of the self-coloring type pressure-sensitive recording paper before laminating, an increase of 0.01 points or less is excellent, a value greater than 0.01 points and 0.03 points or less is average, and more than 0.03 points A large increase was judged poor.

[Confidentiality] When the opaque coating sheet of each pressure-sensitive recording sheet is peeled off and pressed again with a finger,
When the re-adhesion was not possible at all, the secrecy was excellent, when the re-adhesion was easy, the secrecy was poor, and when the thermo-compression bonding at about 120 ° C. was performed, the re-adhesiveness was judged as the secrecy level.

[Peelability] The peelability of each pressure-sensitive recording sheet was measured by cutting only the opaque coating sheet at one end of the opaque coating sheet of the sample cut into a width of 30 mm, and removing the opaque coating sheet from the thermoplastic resin laminate layer. It peeled and evaluated. When the opaque coating sheet can be easily peeled off, the opaque coating sheet can be peeled off, but the peeling is a little heavy and the color develops on the pressure-sensitive recording layer. The case where the peeling was so heavy that the sheet was destroyed was judged as poor.

[0056]

[Table 1]

Evaluation: In the pressure-sensitive recording sheets obtained in Examples 1 to 7, the thermoplastic resin laminate layer was sufficiently adhered to the pressure-sensitive recording layer, and only the opaque coating sheet was peeled off neatly at the time of peeling, and The opaque cover sheet was uniform and had good release properties, and the thermoplastic resin laminate layer remained adhered to the pressure-sensitive recording layer. All the pressure-sensitive recording layers after peeling off the opaque coating sheet have good color development, and there is no background fog when peeling off the opaque coating sheet. I had one.

On the other hand, in the thermocompression bonding of the thermoplastic resin laminate layers obtained as a comparison, although the peeling occurred from the thermoplastic resin laminate layers, the background fog which seems to have occurred during the thermocompression bonding to the pressure sensitive recording layer. Occurred. Further, in the sample in which the opaque coating sheet was not subjected to the peeling treatment, the thermoplastic resin laminate layer adhered sufficiently to the pressure-sensitive recording layer, and only the opaque coating sheet peeled at the time of peeling, but the peeling was heavy and the opaque coating There was a problem in releasability such as a background fog when peeling the sheet.

[0059]

In the pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque coating sheet are integrated by the thermoplastic resin laminate layer, and the opaque coating sheet is lightly pressed to the thermoplastic resin laminate layer and the pressure-sensitive recording sheet. It can be separated (peeled) from the support having a layer. The pressure-sensitive recorded information can be handled without being exposed to the outside and exposed, and the opaque coating sheet can be peeled off as necessary to read the pressure-sensitive recorded information inside. Furthermore, once disclosed information has the feature that it cannot be hidden again (prevention of re-adhesion), and it has many uses such as continuous slips, pasting slips, labels, postcards and other correspondence, recording, dust-free recording paper, etc. It is of great practical significance that can be used.

[Brief description of drawings]

FIG. 1 is a sectional view of a pressure-sensitive recording sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Opaque cover sheet 2 Release treatment layer 3 Thermoplastic resin laminate layer 4 Pressure sensitive recording layer 5 Support 6 Opaque cover sheet subjected to release treatment 7 Pressure sensitive recording sheet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Ninohira 34-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Paper Mills, Ltd.

Claims (3)

[Claims] 1. A pressure-sensitive recording layer and an opaque coating sheet, wherein a color former or a color developer, both or one of which is microencapsulated, is individually laminated on one surface of a support or mixed and applied. In a pressure-sensitive recording sheet integrated via a thermoplastic resin laminate layer, the surface of the opaque coating sheet on the side in contact with the thermoplastic resin laminate layer is subjected to a mold release treatment. Recording sheet. 2. The pressure-sensitive recording sheet, release treatment,
The pressure-sensitive recording sheet according to claim 1, wherein the pressure-sensitive recording sheet is made by containing one or more kinds of compounds selected from a silicone compound, a fluorine compound and a surfactant. 3. A sheet having a pressure-sensitive recording layer, which is formed by laminating a color-forming agent or a color-developing agent, both or one of which is microencapsulated, individually on one surface of a support, or by mixing and coating them. A sheet having a pressure-sensitive recording layer by arranging an opaque coated sheet having a release treatment on at least one surface, the pressure-sensitive recording layer and the release-treated layer are opposed to each other, and a thermoplastic resin is melt-extruded in the middle thereof. A method for producing a pressure-sensitive recording sheet, which comprises laminating an opaque cover sheet with the opaque cover sheet.