JPH08183245A - Lamination type pressure-sensitive recording sheet - Google Patents

Abstract

PURPOSE: To provide a lamination type pressure-sensitive recording sheet having uniform and stable releasability. CONSTITUTION: A pressure-sensitive recording layer formed by laminating a color former and a coupaler one of which or both of which are microencapsulated independently or applying a mixture of them and an opaque cover sheet are integrated with the single surface of a support through an ethylene polymer laminate layer containing an oxidation inhibitor. By this constitution, a lamination type pressure-sensitive recording sheet extremely stable in peel strength at the time of the peeling of the opaque sheet, not extremely changed in peel strength even if there is slight irregularity in laminating conditions and having stable quality is obtained. This recording sheet is also excellent in production stability of laminate processing at the time of production. Further, data can be recorded on the internal pressure-sensitive recording part by pressure and, when internal data is disclosed by peeling the opaque cover sheet, the opaque cover sheet is not again bonded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated pressure-sensitive recording sheet, in which an opaque coating sheet is provided on a single-form self-coloring pressure-sensitive recording layer provided on a support through a polyolefin laminate layer. It is a laminated type pressure-sensitive recording sheet having internal coloring property, and the opaque coating sheet has releasability, and has a non-exposure of recording, water resistance, chemical resistance, oil resistance, and scratch resistance. As a laminated pressure-sensitive recording sheet, it can be used as a recording sheet for slips, messages, entertainment items, clean rooms, etc., which has particularly 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, phenol resin, organic acid substances, etc. on the coating. Substance (hereinafter referred to as developer)
The manufacturing method by two-layer coating consisting of two steps (including the reverse coating order) and the above-mentioned 2
Ingredients, or any one of the ingredients is microencapsulated, mixed evenly, and applied in a single layer to prepare a coating (Japanese Patent Publication No.
No. 7-16096) is known. In such a self-coloring pressure-sensitive recording sheet, since a color former and a developer are present in the vicinity, it is easy to obtain a printed image with high color density, but unintentional and 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. In addition, the pressure-sensitive information recorded on the self-coloring pressure-sensitive recording sheet is inevitably exposed to the public, and if you want to hide the information content, you must put it in a separate bag. It was

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. 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 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. Further, a heat-sealable or thermoplastic resin coating layer is provided on the recording layer of the self-coloring 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-sealable adhesive, Method of integrating by hot pressing (Japanese Utility Model Laid-Open No. 2-2173, Japanese Utility Model Laid-Open No. 3-116974)
However, if it is hot pressed enough to be integrated, color fog in the pressure-sensitive recording layer will be lost and the commercial value will be lost, or if a resin with an adhesive strength much weaker than the adhesive strength is used, it will be adhered with a light press. There was no choice but to integrate by force. 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.

In order to avoid such a problem, a method of adhering a self-coloring pressure-sensitive recording sheet and an opaque coating sheet with a thermoplastic resin laminate layer (Japanese Patent Laid-Open No. 5-27817).
No. 5, JP-A-5-307362). According to this method, it is possible to make a system which has non-disclosure of recording, avoids coloration fogging of the pressure-sensitive recording layer at the time of manufacturing, and does not re-adhere after the opaque coating sheet is once peeled off. It had the problem shown in. That is, in such a structure, it is difficult to make a sufficient difference between the adhesive strength between the pressure sensitive recording layer / thermoplastic resin laminate layer and the adhesive strength between the thermoplastic resin laminate layer / opaque coating sheet, and the pressure sensitive recording layer / If the thermoplastic resin laminate layers are strongly adhered to each other, there is a phenomenon that the thermoplastic resin laminate layer / the opaque coating sheet is not peeled off or is hardly peeled off. As a factor for controlling the adhesive strength between the pressure-sensitive recording layer or the opaque coating sheet and the thermoplastic resin laminate layer, the thermoplastic resin species, the presence or absence of the additive compound in the thermoplastic resin and the additive species and the amount of additive, Presence or absence of surface treatment such as corona treatment or ozone treatment on the surface of pressure-sensitive recording sheet, opaque coating sheet or molten thermoplastic resin, surface treatment strength, preheating temperature of pressure-sensitive recording sheet or opaque coating sheet, or thermoplasticity during lamination Resin temperature, etc. are mentioned.

However, the self-coloring pressure-sensitive recording layer originally has poor adhesiveness to the thermoplastic resin laminate layer, probably because the adhesiveness to the microcapsules present on the surface is poor, and the thermoplastic resin species is not good. And its temperature, or control by preheating or surface treatment of the pressure-sensitive recording sheet or opaque coating sheet, the adhesive strength between the pressure-sensitive recording layer / thermoplastic resin laminate layer and the thermoplastic resin laminate layer /
It was difficult to make a sufficient difference in the adhesive strength between the opaque cover sheets. That is, when the peeling level between the thermoplastic resin laminate layer and the opaque coating sheet is controlled to a practical level, the adhesive force between the pressure-sensitive recording layer / thermoplastic resin laminate layer decreases, and, for example, when printing with an impact printer, the laminating float ( The laminate floats from the pressure-sensitive recording layer, and air bubbles enter in the middle). In addition, even if an additive such as a fatty acid amide, an antistatic agent, an anti-blocking agent, or an ultraviolet absorber is mixed in the thermoplastic resin to try to control the adhesive strength, the adhesive strength of the pressure-sensitive recording layer / thermoplastic laminate layer is improved. It is weak, the production stability of the laminate is poor depending on the additive, the melt extrusion die is contaminated, and resin boro (heat-deteriorated substances or aggregates of the laminate resin and additives) occurs in the laminate layer. There are problems that the surface property is deteriorated and unnecessary color is generated.

In addition, there is a problem that the peelability in the width direction of the web is large when the melt extrusion die is used to produce a wide width. The releasability depends on the laminating temperature and the press pressure. The higher the laminating temperature, the more
Larger pressing pressure tends to cause heavy peeling. At the time of melt extrusion lamination, it is impossible to completely avoid the resin temperature unevenness due to the temperature unevenness of the die and the like, and the unevenness of the press pressure depending on the location, and since these unevenness appear as fluctuations in peelability, it is preferable. Absent.

Further, although it is considered that the unevenness of the fibers constituting the opaque coating sheet is considered to be an influence, the peeling property when peeling the opaque coating sheet is likely to vary, and a local strong adhesion site is recognized. The pressure-sensitive recording layer may develop color, which is not preferable as a recording sheet. When the press pressure at the time of laminating a thermoplastic resin is decreased to avoid such microscopic excessive adhesion, the adhesion itself of the opaque covering sheet deteriorates, and the natural peeling of the opaque covering sheet or the laminate layer at the time of peeling the opaque releasing sheet There is a problem that it causes a fatal defect as a product such as peeling.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a laminated pressure-sensitive recording sheet having an opaque coating sheet, without sacrificing its original color developability, and a pressure-sensitive recording layer and a thermoplastic resin. Adhesion of the ethylene polymer laminate layer used as is good, the difference in adhesive strength between the pressure-sensitive recording layer / ethylene polymer laminate layer and the ethylene polymer laminate layer / opaque cover sheet is sufficiently large, and the opaque cover sheet is produced. It shows stable peeling properties even with slight changes in the laminating conditions at the time, there is no unnecessary color development at the time of peeling due to the presence of microscopic excessive adhesion sites, and there is no disclosure of information. The opaque coated sheet has a confidentiality property that prevents re-adhesion, and the ethylene polymer laminate layer has good adhesiveness during actual use, and it is a laminated type that can prevent recording alteration and contamination. To provide a pressure recording sheet. The ethylene polymer in the present invention means a generic term for polyethylene and a copolymer of ethylene and α-olefin.

[0010]

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, which are obtained 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 or coated. A pressure-sensitive recording sheet integrated with a laminate layer, which is an invention of a laminated pressure-sensitive recording sheet comprising an ethylene polymer laminate layer containing an antioxidant.

The details of the present invention will be described below. In the laminated pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording sheet and the opaque coating sheet can be integrated when melt-extruding the ethylene polymer laminate layer, and the adhesive strength (peel strength) of the ethylene polymer laminate layer By changing the pressure sensitive recording sheet side and the opaque coating sheet side, the opaque coating sheet having relatively weak adhesive strength with the ethylene polymer laminate layer can be peeled off.

The antioxidant used in the present invention is a phenol type (which works as a radical chain inhibitor), a phosphorus type, or a sulfur type (which works as a peroxide decomposing agent) generally used as an antioxidant for plastics. Of antioxidants. Generally, the antioxidant is used for preventing the deterioration of the quality of the plastic due to the oxidative deterioration mainly caused by oxygen in the air, but the antioxidant is added to the ethylene polymer laminate layer in the present invention. Unexpectedly, it has been found that the inclusion of the above makes it possible to obtain a stable peeling quality by reducing the fluctuation of the peeling property due to the fluctuation of the resin temperature and the press pressure in the web width direction during the lamination. . The antioxidant used in the present invention is not particularly limited as long as it is usually used as an antioxidant for plastics, and examples thereof include the following substances.

As a monophenol antioxidant, 2,
6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5-
Di-tert-butyl-4-hydroxyphenyl) propionate, etc.

As a bisphenol antioxidant, 2,
2'-methylenebis (4-methyl-6-tert-butylphenol, 2,2'-methylenebis (4-ethyl-
6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol),
4,4'-butylidene bis (3-methyl-6-tert
-Butylphenol), 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10- Tetraoxaspiro [5,5]
Undecane, etc.

As a polymeric phenolic antioxidant,
1,1,3-tris (2-methyl-4-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5
-Trimethyl-2,4,6-tris (3,5-di-te
rt-Butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-ter)
t-butyl-4'-hydroxyphenyl) propionate] methane, [3,3 '-(4'-hydroxy-3'-
tert-Butylphenyl) butyric acid] glycol ester, 1,3,5-tris (3 ′, 5′-di-tert-butyl-4′-hydroxybenzyl) -S
-Triazine-2,4,6- (1H, 3H, 5H) trione, tocopherol, etc.

As a sulfur type antioxidant, dilauryl 3,
3'-thiodipropionate, dimyristyl 3,3'-
Thiodipropionate, distearyl 3,3′-thiodipropionate, etc.

Triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, 4,4'-butylidene-bis (3-methyl-6-tert-butylphenylditridecyl) phosphite as phosphorus antioxidants , Cyclic neopentanetetraylbis (octadecylphosphite), tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10- Phosphaphenanthrene-10-oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-
10-phosphaphenanthrene-10-oxide, 1
0- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-
Phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-tert)
-Butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-butyl-4-4
Methylphenyl) phosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) octylphosphite, and the like.

These may be used alone or in combination of two or more, but for ethylene polymers, especially monophenol type, bisphenol type and polymer type phenol type antioxidants are used. Is common.

The concentration of the antioxidant added to the ethylene polymer laminate layer varies depending on the type of the ethylene polymer resin and the antioxidant used, but it is 50 to 5000 pp.
It is preferably in the range of m. When the amount is less than this, the peelability of the opaque coated sheet becomes unstable along with the variation of the laminating conditions at the time of production, and when the amount is more than this, the adhesiveness between the ethylene polymer laminate layer and the pressure sensitive recording layer becomes weak.

The ethylene polymer constituting the ethylene polymer laminate layer in the present invention refers to polyethylene and ethylene / α-olefin copolymers, and examples thereof include the following substances. High-density polyethylene, low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, ethylene / propylene or 4-methylpentene-1 random copolymer or block copolymer, and the like. These can be used alone or as a mixture. The mixing method is not particularly limited, and any method can be used. For example, extruder for kneader, heating kneading roll, Banbury mixer, a predetermined amount of ethylene polymer resin and antioxidant using a kneader, and if necessary various additives (pigment, release agent, lubricant, (A dispersant, a neutralizing agent, etc.) are added and melt-mixed, and then the mixture is pulverized and pelletized, or a method in which a so-called simple blend is directly put into an extruder to perform extrusion coating,
Etc. can be used.

The laminate layer may be an ethylene polymer laminate layer alone, or may be two or more layers by coextrusion lamination. In the case of two or more layers, the layer in contact with the opaque cover sheet needs to be an ethylene polymer laminate layer containing an antioxidant, but the laminate layer on the side in contact with the pressure-sensitive recording layer is made of any thermoplastic material. A resin may be used, and it does not matter whether or not an antioxidant is used. Hereinafter, a laminate layer made of only an ethylene polymer and two or more thermoplastic resin laminate layers containing an ethylene polymer laminate layer will be simply referred to as a laminate or a laminate layer unless otherwise specified.

By setting the thickness of the laminate layer to be in the range of 8 to 50 μm, preferably 10 to 30 μm, the gloss, scratch resistance and abrasion resistance of the printed surface can be achieved without lowering the color developability of the pressure sensitive recording layer from the practical level. Not only to improve the film quality, but also to function as a release layer that is released from the opaque coating sheet. When the thickness of the laminate layer is thinner than this range, when the opaque coating sheet is peeled off, the laminate layer is lifted such that the laminate layer is peeled off from the pressure-sensitive recording layer, or the background fog of the pressure-sensitive recording layer occurs, It may be difficult to read the records. If the thickness of the laminate layer is thicker than this range, not only the cost is disadvantageous, but also curl control is difficult and 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 by laminating, a general laminator such as a melt extrusion die, a T die, and a multi-layer simultaneous extrusion die can be used. As a pretreatment for melt extrusion, what is necessary is to perform known surface treatment for improving adhesion such as corona treatment, flame treatment, ozone treatment, ultraviolet irradiation treatment, electron beam irradiation treatment on the pressure-sensitive recording layer or the opaque coating sheet. It doesn't matter. 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.

By coating at least one of the aqueous polymer and the sizing agent on the side of the opaque cover sheet which is in contact with the laminate layer, the releasability of the opaque cover sheet becomes more uniform and stable. When using a sizing agent, there is a method of applying it to the opaque coating sheet depending on the internal size or surface size, but in order to reduce peeling unevenness in the web width direction, apply a sufficient amount of sizing agent easily. The coating method that can be used is most preferable.

The coating amount of the aqueous polymer or sizing agent varies depending on the smoothness and air permeability of the opaque coating sheet to be used, and the type, thickness and processing conditions of the ethylene polymer laminate layer, but it is 2 to dry weight. It is preferably in the range of 10 g / m ² . If it is less than this range, the opaque coating sheet is not sufficiently covered with the aqueous polymer or sizing agent, and if it is more than this range, the recording density is lowered when pressure-sensitive printing is performed, which is not preferable as a recording sheet.

The aqueous polymer referred to herein is a water-soluble polymer or a water-dispersible polymer (latex, emulsion, etc.).
However, the present invention is not limited to these.

As the water-soluble polymer, starches (starch, oxidized starch, esterified starch, phosphate esterified starch, hydroxyethylated starch, acetylated starch, cationized starch, dextrin, etc.), natural polymeric polysaccharides (Agar, xanthan gum, pullulan, chitosan, star gum, guar gum, gum arabic, tragacanth gum, alginic acid derivative, etc.), casein, gelatin, (modified) polyvinyl alcohol (completely saponified, partially saponified, esterified, carboxy modified, cation modified, cation modified, Acetoacetyl-modified, sulfonic acid-modified, amide-modified, nitrile-modified, various other modified polyvinyl alcohol, etc.), polyvinyl ethers (polyvinyl methyl ether, etc.), polyvinyl pyrrolidone, acrylic polymer (polyacrylic acid, Liacrylamide, polyacrylic acid esters, polyacrylic acid salts, etc.), cellulosic polymers (methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, etc.), polyacryloylmorpholine, polyethylene glycol, polyethylene glycol diamine, water-soluble epoxy compounds, water-soluble Alkali of polyester, polyethyleneimine, polyallylamine, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, isobutylene / maleic anhydride copolymer, styrene / maleic anhydride copolymer Salts, alkali salts of ethylene / maleic anhydride copolymers, styrene / acrylic acid copolymers, etc.

As the water-dispersible polymer, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, ethylene / vinyl acetate copolymer, vinyl acetate / acrylic acid (ester) Latex type polymers such as copolymers, acrylonitrile / butadiene / acrylic acid copolymers, polyethylene, polyvinyl acetate, polyurethane, vinylidene chloride,
Polychloroprene, organopolysiloxane emulsion, etc.

Any sizing agent may be used as long as it is commonly used, for example, alkyl ketene dimer sizing agent, alkenyl succinic acid sizing agent, olefin sizing agent, styrene sizing agent, acrylic sizing agent. , Styrene / acrylic sizing agent, styrene /
Maleic acid-based sizing agent, olefin / styrene-based sizing agent, diisobutylene / maleic anhydride-based sizing agent, starch-based sizing agent, rosin-based sizing agent, wax-based sizing agent, higher fatty acid-based sizing agent, silicone Examples include, but are not limited to, system sizing agents.

These aqueous polymers or sizing agents may be used alone or in combination of two or more. Also, if necessary, pigments, defoaming agents, surfactants, p
There is no problem in properly blending an H modifier, a lubricant, an antistatic agent, an anti-curl agent, and the like.

The adhesive strength between the ethylene polymer laminate layer and the pressure-sensitive recording layer is preferably an adhesive strength (peel strength) of 100 gf / 15 mm or more in a 180 degree peel test in a Tensilon universal tensile tester. If the adhesive strength of the ethylene polymer laminate layer is at least this value, the pressure-sensitive recording layer will develop color even if the ethylene polymer laminate layer is forcibly peeled off, so that the adhesive strength is sufficient.

If the adhesive strength between the pressure sensitive recording layer and the ethylene polymer laminate layer is less than this value, the following problems may occur. In principle, the adhesive strength between the opaque coating sheet and the ethylene polymer laminate layer is less than the adhesive strength between the ethylene polymer laminate layer and the pressure-sensitive recording layer, but the opaque cover sheet can be peeled off, but the adhesive strength is too high. If they are too close to each other, the ethylene polymer laminate layer may float (partially peel off) from the pressure-sensitive recording layer, the pressure-sensitive recording layer may develop color when the opaque coating sheet is peeled off, or Depending on the thickness, the opaque cover sheet may be broken when peeled off.

The adhesive strength between the ethylene polymer laminate layer and the opaque cover sheet varies depending on the thickness and type of the opaque cover sheet, the thickness of the ethylene polymer laminate layer, or the color developability of the pressure-sensitive recording layer. But,
It is preferable that the adhesive strength (peeling strength) is smaller than 80 gf / 15 mm in a 180 degree peeling test in a Tensilon universal tensile tester.

The variation in peel strength between the opaque coating sheet and the ethylene polymer laminate layer in the web width direction is 30 gf / 15 mm in difference between the maximum peel strength and the minimum peel strength in order to provide uniform quality. It is preferably within the range, and more preferably within the range of 20 gf / 15 mm. When it exceeds this range, when the opaque coating sheet is actually peeled off, the difference in peeling feeling depending on the sample becomes remarkable, and quality control in manufacturing becomes difficult.

As the support and the opaque coated 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, and wood pulp, synthetic pulp, filler and sizing agent can be used. Raw materials commonly used in papermaking, such as a paper-strengthening agent and a dye, can be used as necessary. Also, plastic sheets such as polyethylene, polypropylene, polyethylene terephthalate, polyamide, polyvinyl chloride, polyvinylidene chloride, and polymethylpentene, and synthetic paper or non-woven fabric made of these synthetic fibers, or a laminate in which synthetic resin is laminated on one side It is also possible to use paper, metal foil, or a laminated product of a metal foil and paper, a vapor-deposited paper, a hologram-treated opaque sheet, a laminated product with a synthetic resin film, mica paper, glass paper, or the like. These supports can be made opaque with inorganic or organic pigments, inks, toners and the like.

In the method of the present invention, the base paper mainly composed of natural pulp (including waste paper pulp), which is advantageously used as a support and an opaque coated sheet, includes starch, starch derivative (cationized starch, phosphate esterification). Starch, oxidized starch, etc.), polyvinyl alcohol, polyvinyl alcohol derivatives (fully saponified, partially saponified,
Carboxy-modified, cation-modified, other various modified polyvinyl alcohol), polyacrylamide, gelatin (alkali-treated, acid-treated, various modified gelatin), various polymer compounds such as star gum and alginic acid derivative and other natural polymer polysaccharides, dry paper Strength enhancer, wet paper strength enhancer, stabilizer, pigment, dye, antioxidant, optical brightener, various latex, inorganic electrolyte (sodium chloride, sodium sulfate, sodium phosphate, calcium chloride, lithium chloride, magnesium chloride) , Magnesium sulfate, barium chloride, etc.), a pH adjusting agent, a fixing agent such as a sulfuric acid band or aluminum chloride, a filler such as calcium carbonate, kaolin, talc, clay, etc., and an additive such as an organic conductive agent may be appropriately combined. it can.

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 microcapsulation method, a microcapsule wall material, 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. As the microencapsulation method, a coacervation method (US Pat. No. 2,800,458 etc.),
An interfacial polymerization method (Japanese Patent Publication No. 47-1763 etc.), an in situ polymerization method (Japanese Patent Application Laid-Open No. 51-9079 etc.) and the like can be used.

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

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 a pressure-sensitive recording material or a heat-sensitive recording material.

As the oil for dissolving the color former, aromatic synthetic oils such as diarylalkane type, alkylnaphthalene type, alkylated biphenyl and hydrogenated terphenyl, and aliphatic synthetic oils such as kerosene, naphtha, paraffin oil and chlorinated paraffin are used. Oils, cottonseed oil, soybean oil, vegetable oils such as linseed 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, 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 / Water-soluble synthetic polymer such as methacrylic acid terpolymer, alkali salt of styrene / maleic anhydride copolymer, latex, polyacrylamide, styrene / maleic anhydride copolymer Compounds and latexes, water-soluble polymers such as alkali salts of ethylene / maleic anhydride copolymers, polyvinyl acetate, polyurethane, polyacrylic acid esters, styrene / butadiene copolymers, acrylonitrile / butadiene copolymers, acrylics Examples thereof include latex such as methyl acid / butadiene copolymer, acrylonitrile / butadiene / acrylic acid copolymer, ethylene / vinyl acetate copolymer and the like.

Pigments used in the pressure-sensitive recording layer or the ethylene polymer 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, UV absorbers such as benzotriazole
Furthermore, a surfactant, a fluorescent dye, etc. are added as needed.

In the laminated pressure-sensitive recording sheet of the present invention,
As a method for forming a pressure-sensitive recording layer on a support, and a method for coating an opaque coating sheet with an aqueous polymer or a sizing agent,
Blade coater, air knife coater, gravure coater, micro gravure coater, roll coater, bar coater, falling curtain coater, rod coater,
A coating method using a known coater such as a die coater, a comma coater and a lip coater is possible. 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 the constitution of the present invention, in order to obtain a high color density, calcium carbonate, talc, silica, clay, barium sulfate, magnesium carbonate, magnesium silicate, between the support and the pressure-sensitive recording layer, 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,
It suffices to provide an undercoat layer containing fine organic pigments such as polyvinyltoluene, styrene / divinylbenzene copolymer, polymethylmethacrylate, urea / formaldehyde polymer and polyethylene.

The laminated pressure-sensitive recording sheet of the present invention is
The pressure-sensitive recording surface, the thermoplastic resin laminate surface, the surface of the opaque coating sheet, or the back surface of the laminated pressure-sensitive recording sheet, a color-developing layer or a developer layer or both for pressure-sensitive recording, a protective coating layer, Release layer, printing layer, tint block printing layer, toner receiving layer, ink receiving layer for ink jet recording, thermal recording layer,
The writing layer, the magnetic recording layer and the like can be provided alone or simultaneously. Further, the laminated 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 copying sheets, adhesive sheets, printing sheets, quality papers, transparent films 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, separation of a part of the opaque coating sheet, processing of perforations and printer feed holes.

[0050]

In the laminated pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque coating sheet are integrated by the laminate layer, and the pressure-sensitive recording layer and the laminate layer are firmly adhered, but the opaque coating sheet. Is relatively weakly adhered, and the opaque cover sheet can be separated (peeled) from the support having the laminate layer and the pressure-sensitive recording layer with a relatively light force.
By using an ethylene polymer containing an antioxidant as the resin forming the laminate layer, the variation in peelability due to the fluctuation of the resin temperature during lamination is reduced,
Stable peeling quality can be obtained. A more uniform peel quality can be obtained by using a combination of an opaque coating sheet coated with an aqueous polymer or a sizing agent on the side in contact with the ethylene polymer laminate layer. When the opaque coating sheet is once separated from the ethylene polymer laminate layer, the ethylene polymer laminate layer is already cooled and solidified, so that it is not easily re-bonded. High color density can be obtained during pressure-sensitive recording, gloss on the printed surface, scratch resistance,
It has excellent abrasion resistance, and because it has an opaque coating sheet, it can handle the information that was pressure-sensitive recorded without exposing it to the outside and exposing it. You can read the pressure-sensitive information. Further, for the reason described above, the information once disclosed has a characteristic that it cannot be hidden again (anti-redeposition property).

[0051]

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 stated, the value indicating the coating amount is the coating amount after drying.

Example 1 As the pressure-sensitive recording paper, a commercially available high-sensitivity self-coloring pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diaself, MCD N130, basis weight 130 g / m ² ) was used. Further, as the opaque coating sheet, woodfree paper having a basis weight of 64 g / m ² was used. 800p using melt extrusion die as ethylene polymer laminate layer
14 g / low density polyethylene containing pm tetrakis- [methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane.
It was melt-extruded at a press linear pressure of 40 kg / cm so that the pressure was m ^2, and the pressure-sensitive recording layer and the opaque coating sheet were attached to each other to obtain an intended laminated pressure-sensitive recording sheet.

Example 2 Example 2 except that 46 ppm of 2,6-di-tert-butyl-p-cresol was used as the antioxidant (although this is less than the preferable content, the effect is small). A laminated pressure-sensitive recording sheet was prepared in the same manner as in Example 1.

Example 3 As an antioxidant, 54 ppm of 2,6-di-tert was used.
A target laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that -butyl-p-cresol was used.

Example 4 250 ppm of 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-hydroxy-5-by using a melt extrusion die as an ethylene polymer laminate layer Methylphenyl) propionyloxy] ethyl]
A 7/3 mixture of low-density polyethylene / high-density polyethylene containing 2,4,8,10-tetraoxaspiro [5,5] undecane was pressed at a line pressure of 40 g to a pressure of 15 g / m ^2.
A target laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that melt extrusion was performed at kg / cm.

Example 5 As an ethylene polymer laminate layer, using a melt extrusion die, polypropylene containing 4700 ppm of 2,6-di-tert-butyl-p-cresol was pressed at a linear pressure of 40 kg / m ² so as to have a pressure of 15 g / m ^2. A laminated pressure-sensitive recording sheet of interest was obtained in the same manner as in Example 1 except that melt extrusion was performed in cm.

Example 6 The concentration of 2,6-di-tert-butyl-p-cresol was changed from 4700 ppm to 5200 ppm (since this is more than the preferred content, an ethylene polymer laminate layer for the pressure sensitive recording layer). Except that the adhesion is slightly deteriorated), and an intended laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 5.

Example 7 Low density polyethylene containing no antioxidant (density: 0.918 g / cc, MFR: 1 on the self-coloring pressure-sensitive recording paper side.
2g / 10 minutes), but also 800 on the opaque coated sheet side
A laminate was produced in the same manner as in Example 1 except that a random copolymer of ethylene / propylene containing ppm of butylated hydroxyanisole was laminated using a multi-layer coextrusion die (lamination weight: 18 g / m ² ). An intended laminated pressure-sensitive recording sheet was obtained.

Example 8 A polyvinyl alcohol aqueous solution was previously applied on the side of the opaque coating sheet that was in contact with the ethylene polymer laminate layer at a coating amount of 3 g /
A target laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 1, except that the coating and drying were performed so that the m ² was obtained.

Example 9 A styrene-acrylic sizing agent (Polymaron 1308, manufactured by Arakawa Chemical Industry Co., Ltd.) was previously coated on the side of the opaque coating sheet that was in contact with the ethylene polymer laminate layer so that the coating amount was 2 g / m ^2. A target laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that the layer was processed and dried.

Example 10 Example 7 was repeated, except that an aqueous solution of hydroxyethyl cellulose was previously coated on the side of the opaque coating sheet that was in contact with the ethylene polymer laminate layer so that the coating amount was 3 g / m ^{2, and} was dried. A target laminated pressure-sensitive recording sheet was obtained in the same manner.

Example 11 An alkylketene dimer sizing agent (Japan P
MC sizing agent, surface sizing agent SS-362) coated amount 2g / m ²
A laminated pressure-sensitive recording sheet of interest was obtained in the same manner as in Example 7 except that the coating and drying were performed so that the above composition was used.

Comparative Example 1 A laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that low density polyethylene containing no antioxidant was laminated.

Comparative Example 2 A laminated pressure-sensitive recording sheet was obtained in the same manner as in Comparative Example 1 except that the melt extrusion was carried out at a press linear pressure of 20 kg / cm.

Comparative Example 3 A laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 7 except that the random copolymer of ethylene / propylene containing no antioxidant was laminated.

Comparative Example 4 800 pp was used instead of the antioxidant in Example 1.
A laminated pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that m erucic acid amide was used.

Test: Examples 1-11 and Comparative Examples 1-4
Of the laminated type pressure-sensitive recording sheet obtained in 1., the peelability, the variation of the peelability in the web width direction, the adhesiveness of the ethylene polymer laminate to the pressure-sensitive recording layer, and the presence or absence of a lami float during printer printing. An evaluation was made. The respective results are shown in Table 1 below.

[Color Development] The color development density of each laminated pressure-sensitive recording sheet was printed by applying a constant weight from the opaque coating side with an impact printer, and then the opaque coating sheet was peeled off to expose the color printed surface. The color density was measured with a Macbeth RD919 reflection densitometer. When the opaque coating sheet could not be peeled off, the measurement was impossible.

[Peelability / Variation of Peelability] When peeling the opaque coating sheet of each laminated pressure-sensitive recording sheet from the ethylene polymer laminate layer, 180 ° peel strength (sample width) using a Tensilon universal testing machine 15 mm). The average value of the peel strength of the samples sampled from 10 positions in the web width (1200 mm) direction was taken as the measured value of the peel property. When the opaque cover sheet could not be peeled off or the opaque cover sheet was broken during peeling, it was determined to be unmeasurable (described as impossible in Table 1). Peel strength is 1
It is preferably in the range of 0 gf / 15 mm or more and less than 80 gf / 15 mm. In addition, the difference between the maximum peel strength and the minimum peel strength of the 10 samples was shown as an index of the variation in the peelability. Maximum / minimum peel strength difference is 30gf / 1
If it exceeds 5 mm, there is a large variation, preferably 20 g.
It is f / 15 mm or less.

[Production stability of laminate] 20000 m
The ethylene polymer laminating process was continuously performed, and the total number of defects (the smaller the number of defects, the better, 5 or more defects per 20,000 m) detected as resin boro or color stain was counted.

[Background color development at the time of peeling] The presence or absence of unnecessary color-developing stains on the self-coloring pressure-sensitive recording paper at the time of peeling the opaque coating sheet was judged. When the opaque coating sheet could not be peeled off, it was determined to be undecidable (described as impossible in Table 1).

[Laminated Adhesiveness] When the opaque coating sheet is peeled off from the laminated pressure-sensitive recording sheet and cellophane tape is attached to the exposed ethylene polymer laminate surface and gently peeled off, the ethylene polymer laminate layer is pressure-sensitive. Those that were not released from the recording layer at all were excellent, and the release area was less than 5% of the cellophane tape attachment area.
The case of 10% or more and less than 30% was judged as poor, and the case of 30% or more and the case where liberation occurred at the time of peeling the opaque coated sheet were judged as unacceptable. When the opaque coating sheet could not be peeled off, it was determined to be undecidable (described as impossible in Table 1).

[Presence or absence of lami floating during printer printing]
During the "color development" test, the presence or absence of lami-lifting (partial peeling) of the ethylene polymer laminate layer from the pressure-sensitive recording layer was visually judged. When the opaque coating sheet could not be peeled off, it was determined to be undecidable (described as impossible in Table 1).

[0074]

[Table 1]

Evaluation: The laminated pressure-sensitive recording sheets obtained in Examples 1 to 11 had no problem in production stability in the laminating step, and the laminate layer adhered sufficiently to the pressure-sensitive recording layer and was opaque when peeled. Only the covering sheet peeled off cleanly, and the opaque covering sheet had a uniform and good peeling property, and the variation in peeling property in the web width direction was small. However, in the case where the content of the antioxidant is less than 50 ppm (Example 2), the variation of the peelability is slightly larger than that of the other Examples and exceeds 20 gf / 15 mm, which is at a usable level. , Not a very good level.
When it exceeded 5000 ppm (Example 6), the adhesiveness between the pressure-sensitive recording layer and the ethylene polymer laminate layer was slightly lower than that in the other Examples (evaluation: acceptable). All of the pressure-sensitive recording layers have good color development, have no fog on the background when the opaque coating sheet is peeled off, and do not cause laminating during printing, and have a confidentiality property that they do not re-adhere once the information is peeled off. Met.

On the other hand, the laminated pressure-sensitive recording sheet obtained in Comparative Example 1 cannot be put to practical use because it adheres to the ethylene polymer laminate layer to such an extent that the opaque coating sheet is difficult to peel off. It was Further, the laminated pressure-sensitive recording sheet obtained in Comparative Example 2 is one in which the opaque coating sheet can be peeled by lowering the pressing pressure at the time of lamination, but the ethylene polymer laminate layer is pressure-sensitive recording at the time of peeling. It was peeled off from the layer, unnecessary coloration was observed at the time of peeling, and the variation in peelability was large. In Comparative Example 3, by applying the co-extrusion laminating method, the adhesiveness between the pressure-sensitive recording layer and the laminating layer and unnecessary color development at the time of peeling were improved,
Variations in peeling were unavoidable, and laminating float during printing was also observed. In Comparative Example 4, instead of the antioxidant,
Although erucic acid amide was used as an additive, resin boro formation occurred and the production stability of the laminate was poor.

[0077]

In the laminated pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer and the opaque coating sheet are integrated by the laminating layer, and there is no problem in the production stability of the melt extrusion laminate, and the opaque coating sheet is relatively It can be separated (peeled) from the support having the laminate layer and the pressure-sensitive recording layer with a light force. Peel strength has little variation in the width direction of the web,
Since it is possible to eliminate the part that adheres excessively in terms of microscopicity, uniform and stable releasability can be obtained without unnecessary background coloration at the time of peeling. Furthermore, the pressure-sensitive recorded information is disclosed to the outside,
It can be handled without being exposed, and by peeling off the opaque cover sheet if necessary, the information pressure-sensitively recorded inside can be read.
It has a feature that it cannot be hidden again (prevention of re-adhesion),
For continuous slips, pasted slips, labels, correspondence such as postcards,
It is of great practical significance because it can be used for many purposes such as recording and dust-free recording paper.

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Claims (4)

[Claims] 1. A pressure-sensitive recording layer in which a color-forming agent or a color-developing agent, both or one of which is microencapsulated, is individually laminated or mixed on one surface of a support, and an opaque coating sheet. The laminated pressure-sensitive recording sheet is characterized by being integrated with an ethylene polymer laminate layer containing an antioxidant. 2. A pressure-sensitive recording layer in which a color-developing agent or a color-developing agent, both or one of which is microencapsulated, is individually laminated or mixed on one surface of a support, and an opaque coating sheet. Are laminated via at least two thermoplastic resin laminate layers, and the thermoplastic resin laminate layer on the side in contact with the opaque coating sheet is made of an ethylene polymer containing an antioxidant. Pressure recording sheet. 3. The laminated pressure-sensitive recording sheet according to claim 1, wherein the content of the antioxidant in the ethylene polymer laminate layer is 50 to 5000 ppm. 4. The opaque coating sheet is formed by coating at least one of an aqueous polymer and a sizing agent on the side in contact with the ethylene polymer laminate layer.
The laminated pressure-sensitive recording sheet according to claim 2 or 3.