JP3204760B2 - Pressure-sensitive recording sheet and method for producing the same - Google Patents

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 more particularly, to a self-coloring type pressure-sensitive recording layer of a single form provided on a support, with a thermoplastic resin laminated layer interposed therebetween. Is an internal color developing pressure-sensitive recording sheet provided with an opaque coating sheet having a releasability, a non-exposure property of recording, water resistance, chemical resistance, oil resistance, and scratch resistance as a type of recording sheet. In particular, it is a pressure-sensitive recording sheet that can be used as a voucher, a communication message, an amusement product, or a recording paper for a clean room, having excellent performance in 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 has been developed from a so-called carbonless copying paper. Also called paper. The composition consists of a step of applying a coating of microcapsules containing a colorless dye (hereinafter referred to as a color forming agent) to a support, and an electron-accepting material such as acid clay, a phenol resin, and an organic acidic substance on the coating. A production method by two-layer coating (including a method in which the order of application is reversed) consisting of two steps and a step of applying a substance (hereinafter referred to as a color developer), or the above two components, or any one of the components. Manufacturing method by microencapsulation, uniform mixing and one layer coating
No. 7-16096). In such a self-coloring pressure-sensitive recording sheet, since a color former and a developer are present in the vicinity, a printed image with a high color density is easily obtained, but unintentional unintended undesired due to friction during production or handling. There is a problem that coloring stains easily occur.

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

[0004] Heretofore, 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. 49-10857) or a recording method having a plastic layer by a melt lamination method. Sheets (Japanese Utility Model Laid-Open No. 52-149709) and examples of providing a release layer on these protective layers are known. However, in reality, when a protective layer is provided by melt lamination or lamination, although unnecessary color stains can be prevented, it is basically assumed that the pressure-sensitive recording portion is exposed, The problem of record confidentiality could not be solved. In addition, a heat-sealable or thermoplastic resin coating layer is provided on the recording layer of the self-coloring type pressure-sensitive recording sheet, and the back surface is overlaid with an opaque cover sheet coated with a hot-melt or thermoplastic heat-sealable adhesive. (Japanese Utility Model Laid-Open No. 2-2173, Japanese Utility Model Laid-Open No. 3-116974)
However, if hot pressing is performed as much as it is integrated, color fogging of the pressure-sensitive recording layer may be caused and the commercial value may be lost.
Alternatively, there is no other option than using a resin having an adhesive strength much lower than the adhesive strength and performing integration by adhesive strength with a light press. Although this type of pressure-sensitive recording sheet has a concealing property of the recording, it can be easily re-adhered only by, for example, re-pressing, and thus has low confidentiality of the recording.

The present applicants have previously described a pressure-sensitive recording layer in which a color former or a developer microencapsulated on one or both sides is individually laminated or mixed on one surface of a support. Using a pressure-sensitive recording sheet in which the opaque covering sheet and the opaque covering 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 strong, and the opaque covering sheet and the thermoplastic resin laminate It has been found that these problems can be solved by weakening the adhesive strength to the layer, but there is a problem that the peelability when the opaque cover sheet is peeled tends to vary. this is,
This is probably because the opaque cover sheet is often formed of 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 covering sheet which is in contact with the thermoplastic resin laminate layer is a paper mainly composed of pulp, 18
Even if the average value of the 0 ° peel test is such that the adhesive strength falls within the allowable range, microscopically, it is thought that the unevenness of the pulp fiber affects the adhesive strength.
Although such a microscopic excessive adhesive strength hardly affects the peeling itself of the opaque cover sheet, it may cause the pressure-sensitive recording layer to develop color, which is not preferable as a recording sheet. If the press pressure at the time of lamination is reduced to avoid such micro excessive adhesion, the adhesiveness itself of the opaque covering sheet is deteriorated, causing a fatal defect such as peeling of the upper paper.

The adhesive strength of the thermoplastic resin laminate layer is a relative comparison between the pressure-sensitive recording layer side and the opaque cover sheet side. Preferably, the adhesive strength of the thermoplastic resin laminate layer on the pressure-sensitive recording layer side is preferable. Is 100 gf / 15 m in a 180 ° peel test using a Tensilon universal tensile tester.
m or more.
If the adhesive strength of the thermoplastic resin laminate layer is less than this range, a trouble of peeling off the thermoplastic resin laminate layer may occur during recording, transport and the like. In addition, if it is more than this range, the pressure-sensitive recording layer will develop color even if the thermoplastic resin laminate layer is forcibly peeled off, so that the adhesive strength is sufficient.

[0007] In principle, the opaque coated sheet can be peeled off if the adhesive strength between the thermoplastic resin laminated layer and the pressure-sensitive recording layer is less than the adhesive strength between the thermoplastic resin laminated layer and the pressure-sensitive recording layer. If the adhesive strength is too close, the thermoplastic resin laminate layer will float (partially peel off) from the pressure-sensitive recording layer, or the pressure-sensitive recording layer will develop color or opacity when the opaque cover sheet is peeled off. Depending on the thickness of the covering sheet, there may be a trouble that the opaque covering sheet is broken at the time of peeling. Such troubles are caused by differences in the thickness and type of the opaque cover sheet, the thickness of the thermoplastic resin laminate layer, or the adhesive strength range caused by the coloring of the pressure-sensitive recording layer.
The adhesive strength (peel strength) is preferably smaller than 80 gf / 15 mm in a 0 ° peel test.

In general, when performing lamination of a thermoplastic resin, the adherend and the polyolefin resin are bonded to each other by a physical anchor effect or by weak hydrogen bonding. Naturally, it is possible to improve the adhesion 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 is such an anchor effect,
It can be strengthened or weakened by changing the ratio of hydrogen bonds or chemical bonds. That is, in order to increase the adhesive strength, the resin temperature and the adherend temperature during melt lamination are increased, the surface of the adherend is roughened, the pressing pressure during lamination is increased to enhance the anchor effect, Corona treatment, flame treatment, UV irradiation,
This is achieved by performing a pretreatment such as an ozone treatment to introduce a polar group and increase the ratio of hydrogen bonds.

Conversely, to lower the adhesive strength, the resin effect and the temperature of the adherend during the melt lamination are lowered, the surface of the adherend is smoothed, and the pressing pressure during the lamination is reduced to lower the anchor effect. Or, reduce the ratio of polar groups without performing pretreatment such as corona treatment, flame treatment, ultraviolet irradiation, ozone treatment on the adherend, or increase the moisture 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 contributing to bonding.

However, from the viewpoint of the production process, the resin temperature and press pressure during the melt lamination are different between the pressure-sensitive recording layer where the adhesive strength is to be increased and the opaque cover sheet where the adhesive strength is to be kept relatively low. At the same time, it is not possible to make a large change. Basically, the resin temperature, the pressing pressure, and the like must be set high so that the adhesive strength on the pressure-sensitive recording layer side is not too small. Under these conditions, even if no pre-treatment such as corona treatment is performed on the opaque coated sheet side, the adhesive strength is considerably high, and if the opaque coated sheet is peeled off very heavily or the opaque coated sheet is peeled off, pressure-sensitive recording There was a problem that the layer developed color.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pressure-sensitive recording sheet having an opaque cover sheet, which has a non-disclosure of information without sacrificing its original color developing property. The peeled opaque cover sheet has the confidentiality that it does not adhere again, and in actual use, the thermoplastic resin laminate layer has good adhesiveness, prevents recording alteration and contamination, and balances peelability and adhesiveness It is an object of the present invention to provide a pressure-sensitive recording sheet having an unclear opaque cover sheet.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, have found the following solutions. That is, a pressure-sensitive recording layer and an opaque coating sheet, which are individually laminated or mixed with a color former or a developer, both or one of which is microencapsulated, on one surface of the support, are formed of a thermoplastic resin. In a pressure-sensitive recording sheet integrated via a laminate layer, a release treatment is performed on a surface of the opaque cover sheet on a side in contact with the thermoplastic resin laminate layer. It is an invention. It is preferable that the release treatment is performed by including at least one compound selected from a silicone compound, a fluorine compound, and a surfactant in the surface of the opaque coated sheet or in the opaque coated sheet. In order to manufacture the article of the present invention, a pressure-sensitive recording layer in which a color former or a developer, both or one of which is microencapsulated, is individually laminated or mixed and applied on one side of a support. Pressure-sensitive by pressing the pressure-sensitive recording layer and the release-treated layer facing each other, and extruding a thermoplastic resin in the middle between the sheet and the opaque cover sheet on which at least one surface has been release-treated. This is performed by laminating a sheet having a recording layer and an opaque covering 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 cover sheet can be integrated when the thermoplastic resin laminate layer is melt-extruded, and the adhesive strength (peel strength) of the thermoplastic resin laminate layer is pressure-sensitively recorded. By changing between the layer side and the opaque covering sheet side, the opaque covering sheet having relatively low adhesive strength to the thermoplastic resin laminate layer can be peeled off.

In the present invention, any method may be used for the release treatment of the opaque cover sheet. For example, there is the following method. That is, on one side of the opaque cover sheet, a silicone compound, a fluorine compound, an aliphatic hydrocarbon-based lubricant, a higher aliphatic alcohol-based lubricant, a higher fatty acid-based lubricant, a fatty acid amide-based lubricant, a metal soap-based lubricant, a fatty acid ester-based lubricant, Apply a cationic surfactant, a nonionic surfactant, an anionic surfactant, an amphoteric surfactant, etc. to an opaque covering sheet, or add internally,
It is impregnated and dried and cured if necessary. Although it is unavoidable to use other binder components together with these release agents, it is preferable to use a binder that does not exhibit substantial tackiness or adhesiveness when heated.

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

Other release agents include mineral oil-based liquid paraffin, fatty acid-based stearic acid and oleic acid.
Natural oils and fats animal and vegetable oils, natural waxes, etc., fatty acid ester-based ethylene glycol fatty acid esters, sorbitol fatty acid esters, polyoxyethylene fatty acid esters, etc., 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 alkoxylate, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl quaternary ammonium halide Compound, perfluoroalkyl polyoxyethylene ethanols, and fluorinated alkyl esters, talc as an inorganic systems. The release agent can be applied in the form of an emulsion, solvent, non-solvent, or mixed melt-extrusion system, and its curing mechanism is solvent evaporation, condensation, addition, cross-linking, ring-opening polymerization, and UV curing. A curing reaction such as an irradiation type or an electron beam irradiation type is possible.

The surfactant used as the release agent includes:
Polyoxyethylene polyoxypropylene block polymer, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, sorbitan acid fatty acid ester, polyoxyethylene sorbitan acid fatty acid ester, fatty acid monoglyceride, polyethylene glycol fatty acid ester, polyoxyethylene alkylamine, etc. Nonionic surfactants, various fatty acid salts such as oleic acid and stearic acid, fatty acid soaps, alkyl sulfates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, higher alcohol sulfates, α- Anionic surfactants such as olefin sulfonates and alkyl phosphates, alkyltrimethylammonium chloride, alkylbenzylmethyl Ammonium chloride, cationic surface active agents, such as other quaternary ammonium salts,
And amphoteric surfactants such as sodium laurylaminopropionate and laurylmethylbetaine.

In the present invention, examples of the binder component include the following substances. As natural polymers and synthetic polymers, starch, modified starch compounds such as oxidized starch, sodium alginate, alginic acid compounds such as 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 / A synthetic polymer such as latex acrylic acid, or a polymer may be used alone or as a mixture, without solvent, dissolved or dispersed in a solvent.

The amount of the release agent to be applied varies depending on the smoothness and air permeability of the opaque cover sheet to be used, and on the type, thickness and processing conditions of the thermoplastic resin laminate layer.
Preferably, the substantial coating amount of the release agent is 0.1 g / m ² or more. Also, in addition to the application to the opaque cover sheet, a method of performing a release treatment on the opaque cover sheet by impregnation, or internally adding a release agent at the stage of manufacturing the opaque cover sheet, and releasing the release agent in the opaque cover sheet There is also a method of immobilizing.

In the case where the thickness of the thermoplastic resin laminate layer is within a certain range and a pressure-sensitive recording sheet having a high coloring property of the pressure-sensitive recording layer is used, the opaque covering sheet almost disperses and absorbs the pen pressure. In order to transmit without pressure, high color density can be obtained at the time of pressure-sensitive recording, and the glossiness, scratch resistance and rub resistance of the printed surface are excellent, and the opaque covering sheet is provided on the thermoplastic resin laminate layer. The information recorded with pressure sensitivity can be handled without exposing and exposing the information to the outside, and the information recorded with pressure sensitivity can be read inside by peeling off the opaque cover sheet as necessary. Further, the information once disclosed cannot be concealed again (anti-adhesion property).

The resin constituting the thermoplastic resin laminate layer includes polyethylene (low density, medium density, high density, linear low density polyethylene), polypropylene, polytrimethylpentene, polybutene, ethylene vinyl acetate copolymer, ethylene ethyl General-purpose melt-extruded resins such as acrylate copolymers, ethylene acrylic acid copolymers, ethylene methyl acrylate copolymers, ethylene vinyl alcohol copolymers, ethylene methacrylic acid copolymers and their salts, vinyl chloride and 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, a predetermined amount of polyolefin resin using an extruder for a kneading machine, a heating kneading roll, a Banbury mixer, a kneader, etc., and various additives as necessary (release agent, slip agent, pigment, antioxidant, neutralization And then melt-mixing and then pulverizing and pelletizing the mixture, or directly extruding the extruder in the state of a so-called simple blend for extrusion coating, or when polymerizing one polyolefin resin 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 gloss, scratch resistance and the like of the printed surface can be improved without deteriorating the color developability of the pressure-sensitive recording layer.
Not only improves the abrasion resistance, but also functions as a release layer that separates from the opaque cover sheet. If the thickness of the thermoplastic resin laminate layer is thinner than this range, when the opaque cover sheet is peeled off, the laminate of the thermoplastic resin laminate layer peels off from the pressure-sensitive recording layer occurs,
In some cases, the recording is difficult to read due to background fogging of the pressure-sensitive recording layer. If the thickness of the thermoplastic resin laminate layer is larger than this range, the recording density is reduced in pressure-sensitive printing, which is not preferable as a recording sheet.

In order to integrate the pressure-sensitive recording layer and the opaque cover sheet by means of a thermoplastic resin laminate, a common laminator such as a melt extrusion die, a T die, or a multilayer simultaneous extrusion die can be used. As a pretreatment for the melt extrusion, any known treatment for improving adhesiveness such as a corona treatment or a frame treatment may be performed on the pressure-sensitive recording layer or the opaque covering sheet. As a matter of course, the degree of surface treatment of the pressure-sensitive recording layer and the opaque covering sheet can be changed to control the adhesiveness and peelability. At the time of lamination by melt extrusion, any of the support having the pressure-sensitive recording layer and the opaque cover sheet may be located on the cooling roll side or on the press roll side, but the pressure-sensitive recording layer having particularly high color development sensitivity may be used. When used, it is preferable to use an opaque covering sheet on the press roll side.

The resin forming the thermoplastic resin laminate layer may contain an organic or inorganic pigment, an organic dye, and a dyeing amount. For example, kaolin, calcined kaolin, talc, pyroxene, diatomaceous earth, carbonated calcium,
Examples 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 materials.

[0025]

As the support and the opaque covering sheet used in the pressure-sensitive recording sheet of the present invention, general papers such as glassine paper, woodfree paper, art paper, coated paper and cast paper can be used. Raw materials usually used in papermaking, such as synthetic pulp, fillers, sizing agents, paper strength agents, dyes, etc., can be used as needed.
In addition, plastic sheets such as polyethylene, polypropylene, polyethylene terephthalate, polyamide, polyvinyl chloride, polyvinylidene chloride, and polymethylpentene, and synthetic paper and nonwoven fabric made of these synthetic fibers,
Or laminated paper with synthetic resin laminated on one side, metal foil, or bonded product of metal foil and paper, vapor-deposited paper, opaque sheet with hologram treatment, bonded product with synthetic resin film, mica paper, glass Paper and the like can also be used. These supports can be made opaque with inorganic or organic pigments, inks, toners and the like. Further, the pressure-sensitive recording layer or a part thereof (a color developer layer or a color former layer), a heat-sensitive layer, a magnetic recording layer, and a print layer are formed on the non-bonded surface of the opaque cover 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 mainly composed of 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, phosphated starch, oxidized starch, etc.), polyacrylamide, polyvinyl alcohol, polyvinyl alcohol derivatives (completely saponified, partially saponified,
Dry paper strength enhancers such as carboxy-modified, cationic-modified, and other various modified polyvinyl alcohols), gelatin (alkali-treated, acid-treated, and various modified gelatins), natural high-molecular polysaccharides such as star gum and alginic acid derivatives, and higher fatty acid metal salts Sizing agents such as rosin derivatives, dialkyl ketones, alkenyl or alkyl succinic anhydrides, epoxidized higher fatty acid amides, organic fluoro compounds, dialkyl ketene dimer emulsions, polyamide polyamine epichlorohydrin resins, melamine resins, urea resins, epoxidized polyamide resins Wet paper strength enhancers, stabilizers, pigments, dyes, antioxidants, optical brighteners, various latexes, etc.
Inorganic electrolyte (sodium chloride, sodium sulfate, sodium phosphate, calcium chloride, lithium chloride, magnesium chloride, magnesium sulfate, barium chloride, etc.), pH
An adjusting agent, a fixing agent such as a sulfate band or aluminum chloride, a filler such as calcium carbonate, kaolin, talc, and clay, and an additive such as an organic conductive agent can be appropriately combined and contained. These inclusions may be dispersed in the pulp slurry at the papermaking stage, may be added at the tab size after papermaking, or the solution may be applied with 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 a conventionally known one can be used. For example, a method of microencapsulation, a wall material of the microcapsule, a color former or an oil for dissolving the color former, or a color developer, an electron beam curable resin, a microcapsule protective agent, or the like. Examples of the microencapsulation method include a coacervation method (U.S. Pat. No. 2,800,458), an interfacial polymerization method (Japanese Patent Publication No. 47-1763, etc.), and an in-situ polymerization method (Japanese Patent Application Laid-Open No. 51-9079, etc.). Can be used.

As the wall material of the microcapsules, polyurethane, polyurea, epoxy resin, urea / formalin resin, melamine / formalin resin and the like can be used.

Examples of the color former include triallylmethane compounds, diarylmethane compounds, xanthene compounds,
There is no particular limitation as long as a thiazine-based compound, a spiropyran-based compound, or the like can be used, as long as it is generally used for a pressure-sensitive recording material or a heat-sensitive recording material.

Examples of oils for dissolving the color former include aromatic synthetic oils such as diarylalkanes, alkylnaphthalenes, alkylated biphenyls and hydrogenated terphenyls, and aliphatic synthetic oils such as kerosene, naphtha, paraffin oils and chlorinated paraffins. Vegetable oils such as oil, cottonseed oil, soybean oil, and linseed oil 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 the color developer include clays (eg, acid clay, attapulgite, etc.), organic acids (eg, aromatic carboxy compounds such as salicylic acid, and metal salts thereof), mixtures of organic acids and metal compounds, An acidic polymer (for example, a phenol-formaldehyde resin, a salicylic acid resin, or a metal salt thereof) or the like can be used.

In the present invention, the binder used for forming the pressure-sensitive recording layer includes starches, cellulose derivatives such as hydroxyethylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose, proteins such as casein and gelatin, starch oxide, and ester compounds. Aqueous natural polymer compounds such as saccharose such as starch, polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, acrylamide / acrylate copolymer, acrylamide / acrylate / Methacrylic acid terpolymer, styrene /
Water-soluble synthetic polymer compounds and latexes such as alkali salts of maleic anhydride copolymer, latex, polyacrylamide, styrene / maleic anhydride copolymer, etc., and water-soluble such as alkali salts of ethylene / maleic anhydride copolymer. Polymer, polyvinyl acetate, polyurethane, polyacrylate, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate /
Butadiene copolymer, acrylonitrile / butadiene /
Latexes such as an acrylic acid copolymer and an ethylene / vinyl acetate copolymer are exemplified.

Examples of the pigment 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.

In addition, zinc stearate as an auxiliary agent,
Higher fatty acid metal salts such as calcium stearate, waxes such as paraffin, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, caster wax, etc., dispersants such as sodium dioctyl sulfosuccinate, sulfonic acid-modified polyvinyl alcohol, benzophenone, A benzotriazole-based ultraviolet absorber, a surfactant, a fluorescent dye, and the like are added as necessary.

In the pressure-sensitive recording sheet of the present invention, the method of forming the pressure-sensitive recording layer includes a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, and the like.
Known coating methods such as a bar coating method and a falling curtain coating method can be used. The pressure-sensitive recording layer is preferably subjected to a smoothing treatment.

Further, in the field of pressure-sensitive recording material production, for example, 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 can be added as necessary.

Further, as a constitution of the present invention, calcium carbonate, talc, silica, clay, barium sulfate, magnesium carbonate, magnesium silicate, 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, polyvinyl toluene, styrene / divinyl benzene Providing an undercoat layer containing a finely divided organic pigment such as a polymer, polymethyl methacrylate, a urea / formaldehyde polymer, or polyethylene can be used without any problem.

The pressure-sensitive recording sheet of the present invention may be used for pressure-sensitive recording on its surface, pressure-sensitive recording surface, thermoplastic resin laminate layer surface, front or back surface of an opaque covering sheet, or the back surface of the pressure-sensitive recording sheet. The color former layer or the developer layer or both, the protective coating layer, the release layer, the printing layer, the tint block printing layer, the toner receiving layer, the ink receiving layer, the thermosensitive recording layer, the writing layer, the magnetic recording layer, etc. alone, Alternatively, they can be provided at the same time. 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 sheets, back carbon copy sheets, adhesive sheets, printing sheets, transparent films, and the like. Processing of a part or the whole of the recording sheet of the present invention, such as die cutting, separation of a part of the opaque cover sheet, processing of perforations, printer feed holes, etc., may be performed at all.

[0041]

In the pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque cover sheet are integrated by a thermoplastic resin laminate layer, and the pressure-sensitive recording layer and the thermoplastic resin laminate layer are firmly adhered to each other. Since the opaque coated sheet has been subjected to a release treatment, it is weakly bonded to the thermoplastic resin laminated layer, and the opaque coated sheet is separated from the support having the thermoplastic resin laminated layer and the pressure-sensitive recording layer with a light force. (Peel). Once the opaque cover sheet is separated from the thermoplastic resin laminate layer, the thermoplastic resin laminate layer has already cooled and solidified, so it will not easily re-attach. Since the thermoplastic resin laminate layer transmits the pen pressure almost without dispersing and absorbing, a high color density can be obtained at the time of pressure-sensitive recording, and the printed surface has excellent gloss, scratch resistance, and friction resistance. Since it has a thermoplastic resin laminate layer and an opaque cover sheet, it is possible to handle pressure-sensitive recorded information without revealing it to the outside and to handle it without exposing it. The recorded information can be read. In addition, for the reasons described above, once disclosed,
It has the characteristic that it cannot be concealed again (anti-adhesion property).

[0042]

EXAMPLES 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 percentages shown below are based on weight. Also,
The value indicating the amount of smear is the amount of smear after drying unless otherwise specified.

Example 1 A commercially available high-sensitivity self-coloring type pressure-sensitive recording paper (Mitsubishi Paper Mills, Diamond Self, MCD N130, basis weight 130 g / m ² ) was used as the pressure-sensitive recording paper. A single-sided cast paper having a basis weight of 70 g / m ² was used as the opaque covering sheet, 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 side. Was applied at a solid content of 1 g / m ² and dried by heating. The pressure-sensitive recording surface is subjected to a corona treatment, and a low-density polyethylene (density: 0.918 g / cc, M
FR: 12 g / 10 min) and high density polyethylene (density:
0.955 g / cc, MFR: 37 g / 10 min) and an equal mixture of 15 kg / m ² and a press linear pressure of 28 kg.
/ Cm and extruded with the release surface of the pressure-sensitive recording layer and the opaque coating sheet as the bonding surface.
The desired pressure-sensitive recording sheet was obtained.

Example 2 The same self-coloring type pressure-sensitive recording paper as in Example 1 was used as the pressure-sensitive recording paper. Example 1 as an opaque covering sheet
Using a single-sided cast paper similar to that described above, and using a fluorine compound as a release agent on the non-cast side (3M, Florad FC
170C) and 2% of trimethylolpropane triacrylate (a photoinitiator Irgacure 65 manufactured by Ciba-Geigy).
(Including 5% of 1) at a rate of ² g / m ² and cured by irradiation with ultraviolet light. A corona treatment is applied to the pressure-sensitive recording surface, and a low-density polyethylene (density: 0.918 g / cc, MF
R: 12 g / 10 minutes) and polypropylene (density: 0.9
An equivalent mixture of 0.5 g / cc, MFR: 15 g / 10 min) was pressed to a linear pressure of 28 kg / cm ² so that the mixture became 15 g / m ^2.
, And bonded together with the release-treated surface of the pressure-sensitive recording layer and the opaque cover sheet as a bonding surface to obtain the desired pressure-sensitive recording sheet.

Example 3 The same self-coloring type pressure-sensitive recording paper as in Example 1 was used as the pressure-sensitive recording paper. Example 1 as an opaque covering sheet
2 g of polyvinyl alcohol containing 5% of a cationic surfactant (manufactured by Nippon Emulsifier, New Coal 291M) as a release agent on the non-cast surface using the same single-sided cast paper
/ M ² and heated and dried. A corona treatment is performed on the pressure-sensitive recording surface, 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 min) by melt-extrusion at a press linear pressure of 28 kg / cm so that the mixture becomes 15 g / m ^2, and the pressure-sensitive recording layer and the opaque coated sheet are bonded together as a release surface. The desired pressure-sensitive recording sheet was obtained.

Example 4 The same self-coloring type pressure-sensitive recording paper as in Example 1 was used as the pressure-sensitive recording paper. Example 1 as an opaque covering sheet
2 g / m ^{2 of} polyvinyl alcohol containing 2% of a nonionic surfactant (manufactured by Sanyo Chemical Industries, Nonipol 100) as a release agent on the non-cast surface using the same single-sided cast paper
And dried by heating. The pressure-sensitive recording surface is subjected to a corona treatment, and a low-density polyethylene (density: 0.918) is used as a thermoplastic resin laminate layer using a melt extrusion die.
g / cc, MFR: 12 g / 10 min) and high-density polyethylene (density: 0.955 g / cc, MFR: 37 g / 1)
(0 min), melt-extruded the mixture at a press linear pressure of 28 kg / cm to a weight ratio of 15 g / m ^2, and bonded the release surface of the pressure-sensitive recording layer and the opaque coating sheet as a bonding surface. Thus, an intended pressure-sensitive recording sheet was obtained.

Example 5 The same self-coloring type pressure-sensitive recording paper as in Example 1 was used as the pressure-sensitive recording paper. Example 1 as an opaque covering sheet
Using the same single-sided cast paper as above, polyvinyl alcohol containing 5% of zinc stearate as a release agent was applied at a rate of ² g / m ^{2 to} the non-cast side, and dried by heating. A corona treatment is applied to the pressure-sensitive recording surface, and a low-density polyethylene (density: 0.918 g / cc, MFR: 12 g / 10 min) and polypropylene (density: 0.900 g / cc, MFR:
15 g / 10 min) at a weight ratio of 1: 2 to 15 g / m ^2.
Then, they were melt-extruded at a press linear pressure of 28 kg / cm so that the pressure-sensitive recording layer and the opaque cover sheet were bonded together with the release-treated surface as a bonding surface to obtain an intended pressure-sensitive recording sheet.

Example 6 The same self-coloring type pressure-sensitive recording paper as in Example 1 was used as the pressure-sensitive recording paper. Example 1 as an opaque covering sheet
Using a single-sided cast paper similar to that described above, a fluorine compound (Florard FC72 manufactured by 3M) as a release agent on the non-cast side.
1) was applied at a rate of 1 g / m ² and dried by heating. A pressure-sensitive recording surface is subjected to a corona treatment, and a polypropylene wire (density: 0.900 g / cc, MFR: 15 g / 10 min) is pressed using a melt extrusion die as a thermoplastic resin laminate layer so as to be 18 g / m ^2. The mixture was melt-extruded at a pressure of 28 kg / cm, and bonded together with the release-treated surface of the pressure-sensitive recording layer and the opaque coating sheet as a bonding surface to obtain a target pressure-sensitive recording sheet.

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

Comparative Example 1 As the pressure-sensitive recording paper, the same commercially available high-sensitivity self-coloring type pressure-sensitive recording paper as in Example 1 was used. A corona treatment is applied to the pressure-sensitive recording surface, and a low-density polyethylene (density: 0.918 g) is used as a thermoplastic resin laminate layer using a melt extrusion die.
/ Cc, MFR: 12 g / 10 min) and high density polyethylene (density: 0.955 g / cc, MFR: 37 g / 10
) 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 (single-sided cast paper, basis weight 70 g / m ² ) was also subjected to corona treatment to provide a thermoplastic resin laminate layer similar to that used for the pressure-sensitive recording paper. The pressure-sensitive recording layer and the thermoplastic resin laminate layer provided on the opaque cover sheet were faced to each other, and were heat-pressed and integrated to obtain a target pressure-sensitive recording sheet.

Comparative Example 2 The same self-coloring type pressure-sensitive recording paper as in Example 1 was used as the pressure-sensitive recording paper. Example 1 as an opaque covering sheet
The same single-sided cast paper as above was used, and the non-cast side was used without being subjected to a release treatment. A corona treatment is applied to the pressure-sensitive recording surface, and a low-density polyethylene (density: 0.918 g / c) is used as a thermoplastic resin laminate layer using a melt extrusion die.
c, MFR: 12 g / 10 min) and high density polyethylene (density: 0.955 g / cc, MFR: 37 g / 10)
) Was 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 opaque covering sheet were simultaneously bonded to obtain an intended pressure-sensitive recording sheet.

[Color-forming property] The color-forming density of each pressure-sensitive recording sheet was determined by using an impact printer after further laminating one sheet of pressure-sensitive paper (CBN50 on NCR paper) on an opaque cover sheet. Printing was performed by applying a constant weight, and then the opaque coated sheet was peeled off to expose the color printing 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, relative values of 95% or more were excellent, relative values of 85% or more and less than 90%, and values of less than 85% were inferior.

[Background Fog] The background fog of each pressure-sensitive recording sheet was measured by exfoliating the opaque cover sheet to expose the thermoplastic resin laminate layer, and measuring the optical density of the background with a Macbeth reflection densitometer. Based on the optical density of the background of the self-coloring type pressure-sensitive recording paper before lamination, an increase of 0.01 points or less is excellent, more than 0.01 points and 0.03 points or less, more than 0.03 points Large increases were judged poor.

[Confidentiality] When the opaque covering sheet of each pressure-sensitive recording sheet was peeled off and pressed again with a finger,
The case where no re-adhesion was possible was judged as excellent in confidentiality, the one that could be easily re-adhered was inferior in security, and the one that could be re-adhered when subjected to thermocompression bonding at about 120 ° C. was judged as in average.

[Releasability] The releasability of each pressure-sensitive recording sheet was determined by cutting only the opaque cover sheet at one end of the opaque cover sheet of the sample cut to a width of 30 mm, and removing the opaque cover sheet from the thermoplastic resin laminate layer. After peeling, evaluation was performed. Excellent when the opaque coated sheet can be easily peeled, excellent when the opaque coated sheet can be peeled off, but the peeling is a little heavy, and when the coloration occurs in the pressure-sensitive recording layer. The case where peeling was so heavy that the sheet was broken 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 adhered sufficiently to the pressure-sensitive recording layer, and only the opaque cover sheet peeled off cleanly when peeled off. The opaque cover sheet had uniform and good release properties, and the thermoplastic resin laminate layer remained adhered to the pressure-sensitive recording layer. The pressure-sensitive recording layer after peeling off the opaque cover sheet has good color development, no background fog when the opaque cover sheet is peeled off, and once the information is disclosed after peeling off once, the confidential property that does not adhere again Had.

On the other hand, in the thermocompression bonding of the thermoplastic resin laminate layers obtained as a comparison, the background fogging which seems to have occurred at the time of thermocompression bonding to the pressure-sensitive recording layer, although it is peeled off from the thermoplastic resin laminate layer. Occurred. In the sample in which the opaque cover sheet was not subjected to the release treatment, the thermoplastic resin laminate layer sufficiently adhered to the pressure-sensitive recording layer. There was a problem in releasability such as background fogging when the sheet was peeled off.

[0059]

According to the pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque cover sheet are integrated by a thermoplastic resin laminate layer, and the opaque cover sheet is lightly pressed with the thermoplastic resin laminate layer and the pressure-sensitive record sheet. It can be separated (peeled) from the support having the layer. The information recorded with pressure sensitivity can be handled without being exposed and exposed to the outside, and the information recorded with pressure sensitivity can be read inside by peeling off the opaque cover sheet as necessary. In addition, once disclosed information has the characteristic that it cannot be concealed again (anti-adhesion property), and is used in many applications such as continuous slips, pasted slips, correspondence such as labels and postcards, recording, and dust-free recording paper. It is of great practical significance that can be used.

[Brief description of the drawings]

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

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 opaque cover sheet 2 release treatment layer 3 thermoplastic resin laminate layer 4 pressure-sensitive recording layer 5 support 6 release-treated opaque cover sheet 7 pressure-sensitive recording sheet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-51175 (JP, A) JP-A-6-155897 (JP, A) Japanese Utility Model Showa 60-178125 (JP, U) 10857 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/124

Claims (3)

(57) [Claims] 1. A pressure-sensitive recording layer and an opaque coating sheet each having a color former or a developer, both or one of which is microencapsulated, individually laminated or mixed on one surface of a support. In a pressure-sensitive recording sheet integrated via a thermoplastic resin laminate layer, a release treatment is performed on a surface of the opaque cover sheet in contact with the thermoplastic resin laminate layer. Recording sheet. 2. The pressure-sensitive recording sheet according to claim 1, wherein the release processing comprises:
The pressure-sensitive recording sheet according to claim 1, wherein the pressure-sensitive recording sheet is formed by containing at least one compound selected from a silicone compound, a fluorine compound, and a surfactant. 3. A sheet having a pressure-sensitive recording layer on one side of a support, on which a color former or a developer, both or one of which is microencapsulated, are individually laminated or mixed and applied. A sheet having a pressure-sensitive recording layer, by exposing an opaque cover sheet on which at least one surface has been subjected to a release treatment, by melt-extruding a thermoplastic resin between the pressure-sensitive recording layer and the release-treated layer and in the middle thereof; And a opaque cover sheet.