JP3204803B2 - Pressure-sensitive recording sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to pressure-sensitive recording, and more particularly, to a single-type self-coloring type pressure-sensitive recording layer provided on a support, and an opaque cover sheet provided with a tint block printing for preventing see-through. Is a pressure-sensitive recording sheet that integrates
Non-transparent, copying, water-resistant, chemical-resistant, oil-resistant, abrasion-resistant and dust-inhibiting type recording sheet, especially excellent in color development and handling, re-adhesion prevention and information retention This is a pressure-sensitive recording sheet that has excellent performance and can be used as a recording sheet for labels, slips, correspondence, entertainment items, and clean rooms.

[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. As described above, 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.

[0003] Further, in the self-coloring type pressure-sensitive recording sheet, the pressure-sensitive recorded information is inevitably exposed to the public and has a high degree of publicity. I had to.

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 Application Laid-Open No. 52-149709) and a method in which a release layer is provided on these protective layers, or a method in which a soluble polymer solution is applied on a self-coloring type pressure-sensitive recording layer and dried to form a film. It has been known. However, in these methods, destruction of the microcapsules causes remarkable color fogging, or the microcapsules are covered with the resin, almost losing the original self-coloring pressure-sensitive recording properties, and decreasing both the color density and the color developing speed. Or, basically, it is assumed that the pressure-sensitive recording portion is exposed, so that the problem of non-disclosure of the recording cannot be solved.

An opaque cover sheet (destination display sheet) in which a thermoplastic resin coating layer is provided on a recording layer of a self-coloring type pressure-sensitive recording sheet, and a heat sealable adhesive is applied on the back surface.
(Japanese Utility Model Application Laid-Open No. 2-2173, Japanese Utility Model Application Laid-Open No. 3-116974).
However, if thermocompression bonding is performed so that it is completely integrated, color fogging of the pressure-sensitive recording layer is likely to occur and the commercial value will be lost, or a heat-sealable adhesive resin with adhesive strength much weaker than adhesive strength will be used. There was no other than using light pressure bonding and integrating by adhesive force. This type of pressure-sensitive recording sheet has a low confidentiality of the recording because the recording sheet can be easily re-attached, although the recording is concealed.
Furthermore, as long as the heat-sealable adhesive is used, even if the opaque cover sheet and the pressure-sensitive recording paper having a thermoplastic resin can be integrated, the opaque cover sheet is peeled off once to read the recorded content, and the opaque cover sheet is read. Are superimposed and heat-sealed at a temperature lower than the softening temperature of the thermoplastic resin and higher than the softening temperature of the heat-sealing adhesive (for example, at 30 ° C. to 150 ° C., even a household iron can be easily obtained). Temperature) easily reattached, and had a fatal problem of low confidentiality, which is the most important property of this product. A similar problem occurs when a hot melt type adhesive is used for bonding. Furthermore, when a heat-sealable adhesive is used, there is a problem in that the pen pressure is absorbed and dispersed due to its elasticity, and the pressure-sensitive coloring property may be reduced.

As a result of further study on a pressure-sensitive recording sheet in which an opaque cover sheet and a pressure-sensitive recording paper having a thermoplastic resin (polyolefin resin laminate layer) are integrated with an adhesive or a pressure-sensitive adhesive, as a result of actual examination, It was confirmed that the following problems might occur. That is, when the opaque cover sheet is peeled off, fog (peeling fog) due to poor peeling occurring in the pressure-sensitive recording layer,
Adhesive, adhesive, on the polyolefin resin laminate layer
There is a problem in that a part of the curable resin remains, and the polyolefin resin laminate layer floats from the pressure-sensitive recording surface due to peeling failure when the opaque cover sheet is peeled off. These troubles not only hinder the reading of the pressure-sensitive recording contents, but are also unfavorable in aesthetic appearance, and significantly impair the commercial value.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a self-coloring type pressure-sensitive recording sheet having an opaque cover sheet integrated therein, without sacrificing its original pressure-sensitive self-coloring property, by friction. No color fogging, completely non-disclosure of information if necessary, good adhesion of opaque covering sheet, and good releasability, and when opaque covering sheet is peeled off and information is disclosed even once Is to provide a pressure-sensitive recording sheet having a function that makes it clear that information is disclosed without re-adhering the opaque covering sheet, has no transparency, and has a sufficiently large recordable area on the surface. It is in. In actual use, it is to solve problems such as peeling fog, remaining of a curable resin layer, or floating of a laminate layer.

Further, the opaque coated sheet can be integrated with a pressure-sensitive recording layer without impairing the opacity of the opaque coated sheet.
When performing printing such as ink ribbon printing, flexographic printing, gravure printing, and thermal transfer printing, it is an object of the present invention to provide the pressure-sensitive recording sheet having good printability and color development. Further, the present invention provides a method for integrating an opaque covering sheet and a pressure-sensitive recording layer without causing color fogging or making the opaque covering sheet transparent in a manufacturing process, and without causing wrinkles or curls. It is in.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have reached the following invention. That is, in the pressure-sensitive recording sheet, the pressure-sensitive recording sheet was provided on one side of the support, and a color former or a developer, both or one of which was microencapsulated, were individually laminated or mixed and applied. A laminated recording sheet in which a pressure-sensitive recording layer, a polyolefin resin laminate layer, a curable resin layer, and an opaque covering sheet are sequentially provided, wherein the curable resin layer is a cross-linked resin having a three-dimensional network structure, A pressure-sensitive recording sheet is characterized in that it does not exhibit heat sealing properties in a temperature range below the melting point.

In the pressure-sensitive recording sheet of the present invention, the thickness of the polyolefin resin laminate layer is 10 to 40 μm, and the center line defined by JIS B 0601-1982 on the side of the polyolefin resin laminate layer which is in contact with the curable resin layer. The surface roughness is preferably 0.2 to 12 μm (cutoff value: 0.8 mm, measurement length: 5 mm).

In the pressure-sensitive recording sheet of the present invention, the opaque cover sheet may have an aqueous polymer intermediate layer on the side in contact with the curable resin layer.

In the pressure-sensitive recording sheet of the present invention, the opaque cover sheet is formed by coating a developer or a microcapsule thereof on one side not in contact with the curable resin layer. can do.

In the pressure-sensitive recording sheet of the present invention, the curable resin layer is a curable resin layer cured by one or more curing methods selected from heat curing, redox room temperature curing, ultraviolet curing, and electron beam curing. Is preferred.

Hereinafter, the present invention will be described in detail. In the pressure-sensitive recording sheet of the present invention, the resin forming the curable resin layer provided on the recording surface by the action of the polyolefin resin laminate layer does not seep into the pressure-sensitive recording layer, and a high color-forming density during pressure-sensitive recording is obtained. Obtained, the glossiness of the printed surface, excellent scratch resistance, excellent friction resistance, and because it is integrated with the opaque covering sheet, the pressure-sensitive recorded information can be handled without being disclosed and exposed to the outside, In addition, by peeling off the opaque cover sheet as necessary, the information pressure-recorded inside can be read. The curable resin layer is three-dimensionally cross-linked with a network, and therefore, by using a curable resin having no heat sealing property, the opaque cover sheet once peeled is not re-adhered by heating or pressurizing, and the confidentiality is perfect.

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 a microcapsule, a color former or an oil for dissolving a color former, or a developer, an adhesive 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.

For example, examples of the coloring agent include triallylmethane compounds, diallylmethane compounds, xanthene compounds, thiazine compounds, spiropyran compounds,
Diphenylmethane dyes, spiro dyes, lactam dyes, fluoran dyes, and the like can be used, and are not particularly limited as long as they are generally used in pressure-sensitive recording materials or heat-sensitive recording materials. Specifically, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide,
3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,
2-dimethylindol-3-yl) phthalide, 3-
(P-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3,3-bis (1,2
-Dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (9-ethylcarbazole-
3-yl) -6-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -6-dimethylaminophthalide, 3-p-dimethylaminophenyl-
Triallylmethane dyes such as 3- (1-methylpyrrol-3-yl) -6-dimethylaminophthalide, 4,4 ′
-Bis-dimethylaminobenzhydrylbenzyl ether, N-halophenyl, leuko-olamine, N-2,
Diphenylmethane dyes such as 4,5-trichlorophenyl leuco-olamine, thiazine dyes such as benzoyl leucomethylene ble-, p-nitrobenzoyl leucomethylene ble-, 3-methyl-spiro-dinaphthopyran,
3-ethyl-spiro-dinaphthopyran, 3-phenyl-
Spiro dyes such as spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho (6'-methoxybenzo) spiropyran, 3-propyl-spiro-dibenzopyran, and rhodamine-B-anilinolactam; Lactam dyes such as rhodamine (p-nitroanilino) lactam, rhodamine (o-chloroanilino) lactam, 3-dimethylamino-7-methoxyfluoran, 3-diethylamino-6-methoxyfluoran, 3
-Diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluoran, 3- (N- Ethyl-p-toluidino) -7-methylfluoran, 3-diethylamino-7-N-acetyl-N-methylaminofluoran, 3-diethylamino-7-N-methylaminofluoran, 3-dimethylamino-7- Dibenzylaminofluoran, 3-diethylamino-7-methyl-N-
Benzylaminofluoran, 3-diethylamino-7-
N-chloroethyl-N-methylaminofluoran, 3-
Diethylamino-7-N-diethylaminofluoran,
3- (N-ethyl-p-toluidino) -6-methyl-7
-Phenylaminofluoran, 3- (N-ethyl-p-
Toluidino) -6-methyl-7- (p-toluidino) fluoran, 3-diethylamino-6-methyl-7-phenylaminofluoran, 3-diethylamino-7- (2
-Carbomethoxy-phenylamino) fluoran, 3-
(N-ethyl-N-iso-amylamino) -6-methyl-7-phenylaminofluoran, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-phenylaminofluoran, 3-piperidino -6-methyl-7
-Phenylaminofluoran, 3-pyrrolidino-6-methyl-7-phenylaminofluoran, 3-diethylamino-6-methyl-7-xylidinofluoran, 3-diethylamino-7- (o-chlorophenylamino) fluoran, 3-dibutylamino-7- (o-chlorophenylamino) fluoran, 3-pyrrolidino-6-methyl-
Fluorane dyes such as 7-p-butylphenylaminofluoran and the like.

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

Examples of the color developing agent include clays (for example, activated clay, acid clay, attapulgite, bentonite, colloidal silica, aluminum silicate, etc.) and organic acids (for example, aromatic carboxy compounds such as salicylic acid or metal salts thereof). , A mixture of an organic acid and a metal compound, an acidic polymer (for example, a phenol / formaldehyde resin, a salicylic acid resin, or a polyvalent metal salt thereof such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin, nickel, etc.) Etc. can be used. Electron-accepting substances are used in the same manner as the developer used for thermal recording, and in particular, phenol derivatives, aromatic carboxylic acid derivatives or metal compounds thereof, N, N'-diarylthiourea derivatives, and the like are used. You. Of these, particularly preferred are phenol derivatives, aromatic carboxylic acids and phenolic compounds thereof, and specifically, 1,1-bis (p-
(Hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) butane, 2,2-bis (p-hydroxyphenyl) hexane, bisphenolsulfone, bis ( 3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4'-isopropyloxydiphenylsulfone, 3,4-dihydroxy-4'-methyldiphenylsulfone, diphenol ether, benzyl p-hydroxybenzoate, p -Propyl hydroxybenzoate, p-tert-butylbenzoic acid, trichlorobenzoic acid, octyl 4-hydroxybenzoate, benzoic acid, terephthalic acid, 3-sec-butyl-4-hydroxybenzoic acid, 3-cyclohexyl-4-hydroxy benzoic acid,
3,5-dimethyl-4-hydroxybenzoic acid, salicylic acid, 3-isopropylsalicylic acid, 3-tert-butylsalicylic acid, 3-benzylsalicylic acid, 3- (α-methylbenzyl) salicylic acid, 3-chloro-5- (α- Methylbenzyl), 3,5-di-α-methylbenzylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3-phenyl-5- (α, α-dimethylbenzyl) salicylic acid, p
-Butyl hydroxybenzoate, 4-tert-butylphenol, 4-hydroxydiphenoxide, α-naphtho-
, Β-naphthol, 4-hydroxyacetopheno-
, 4-tert-catechol, 2,2'-dihydroxydiphenol, 2,2'-methylenebis (4-methyl-6
-Tert-isobutylphenol, 4,4'-isopropylidenebis (2-tert-butylphenol), 4,4 '
-Sec-butylidene diphenol, 4-phenylphenol, 4,4'-isopropylidene diphenol, 2,
2'-methylenebis (4-chlorophenol), hydroquinone, 4,4'-cyclohexylidenediphenol,
Examples thereof include phenolic compounds such as dimethyl 4-hydroxyphthalate, hydroquinone monobenzyl ether, novolak type phenol resin, and phenol polymer.

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 such as alkali salts of maleic anhydride copolymers, latex, polyacrylamide, styrene / maleic anhydride copolymers and latexes, and water-soluble compounds such as alkali salts of ethylene / maleic anhydride copolymers. Adhesive resin, polyvinyl acetate, polyurethane, polyacrylate, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, acrylonitrile / butadiene / acrylic acid copolymer, ethylene / Latexes such as a vinyl acetate copolymer are exemplified.

The pigment used in the pressure-sensitive recording layer, the polyolefin resin laminate layer, or the curable resin layer includes:
Diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide,
Examples include silicon oxide, aluminum hydroxide, and urea-formalin resin.

In order to further improve the sensitivity, N-hydroxymethylstearic acid amide may be used as a sensitizer.
Waxes such as stearic acid amide and palmitic acid amide; naphthol derivatives such as 2-benzyloxynaphthalene; biphenyl derivatives such as p-benzylbiphenyl and 4-allyloxybiphenyl; 1,2-bis (3-methylphenoxy) Polyether compounds such as ethane, 2,2'-bis (4-methoxyphenoxy) diethyl ether and bis (4-methoxyphenyl) ether. Carbonic acid or oxalic acid diester derivatives such as diphenyl carbonate, dibenzyl oxalate, and di (p-chlorobenzyl) oxalate can be added.

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 pressure-sensitive recording layer may be formed by a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, or 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, in order to obtain a high color density, calcium carbonate, talc, silica, clay, barium sulfate, magnesium carbonate, magnesium silicate, and the like are provided 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, polyvinyl toluene, styrene / divinyl benzene There is no problem in providing an anchor layer containing a fine organic pigment such as a polymer, polymethyl methacrylate, a urea / formaldehyde polymer, or polyethylene, or dispersing the polymer in the pressure-sensitive recording layer. In particular, in the case of the pressure-sensitive recording sheet of the present invention having a polyolefin resin laminate layer on the pressure-sensitive recording layer, the presence of such a pigment is preferable from the viewpoint of preventing a decrease in color development.

A curable resin that does not dissolve in the polyolefin resin is applied on the polyolefin resin laminate layer,
When fully cured, the solidified curable resin layer adheres to the polyolefin resin laminate layer with cohesive force or a light anchoring effect, but separates (peels) from the polyolefin resin laminate layer with some light force
it can. Even more surprisingly, once the opaque covering sheet is separated, if a curable resin that crosslinks and solidifies in three dimensions is used, the opaque covering sheet and the polyolefin resin laminate layer are heated, It does not adhere again as before by means such as pressurization or radiation irradiation, and has a high level of record keeping. Bonding itself is possible if the polyolefin resin laminate layer is thermally melted, that is, heated and pressed at a temperature equal to or higher than the melting point of the polyolefin resin, but in this case, the opaque cover sheet cannot be separated from the polyolefin resin laminate layer twice and opened. This makes it possible to suppress eavesdropping by a person other than the person himself and has complete secrecy.

Although it was unexpected at the beginning, the three-dimensionally solidified curable resin layer transmits the writing pressure almost without dispersing and absorbing, and is therefore the most important characteristic in pressure-sensitive recording. High color density and resolution can be obtained. Further, it has a characteristic that it has excellent gloss, scratch resistance, and friction resistance of the printed surface.

The polyolefin resin constituting the polyolefin resin laminate layer includes, for example, the following substances. As polyethylene, high-density polyethylene,
Low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, ultra-high-molecular-weight polyethylene, polypropylene such as isotactic, atactic, mixtures thereof, random copolymers or block copolymers with ethylene, and other polymethylpentenes ( TPX) or the like can be used alone or as a mixture.
However, in consideration of the adhesiveness to the curable resin layer, the peelability, and the anti-re-adhesion property, a polyolefin resin containing polyethylene, polypropylene, or polymethylpentene as a main component is preferable. The polyolefin resin laminate can be provided on the pressure-sensitive recording layer by a melt extrusion method of the above substances. As a pretreatment for the melt extrusion, any known treatment for improving the adhesiveness such as a corona treatment and a frame treatment may be performed on the pressure-sensitive recording layer. Further, for the purpose of improving the releasability from the cooling roll at the time of melt extrusion, or for the purpose of improving the releasability when peeling after being integrated with the opaque cover sheet, in these polyolefin resin laminate layers,
Alternatively, it is inevitable to mix a release agent such as a fluorine compound, a silicone compound or an organic metal salt, a lubricant, or the like into the laminate surface, or to fix the release agent or the lubricant by means such as heating or irradiation of radiation.

[0032]

As the polyolefin resin laminate layer, a common laminator such as a melt extrusion die, a T die, and a multilayer simultaneous extrusion die can be used. Also, a polyolefin resin laminate layer can be obtained by bonding a polyolefin resin film on the pressure-sensitive recording layer via a curable resin layer. Furthermore, the polyolefin resin laminate layer provided on the pressure-sensitive recording layer and the polyolefin resin laminate layer provided on the opaque cover sheet can be bonded together by laminating and heat sealing. It is not preferable for this application because it is generated.

In the polyolefin resin laminate layer of the present invention, by setting the thickness of the polyolefin resin laminate layer in the range of 10 to 40 μm, the gloss and scratch resistance of the printing surface can be improved without lowering the color developability of the pressure-sensitive recording layer. Not only improves the friction resistance, but also functions as a release layer for the curable resin layer. If the thickness of the polyolefin resin laminate layer is smaller than this range, the laminate layer will float from the pressure-sensitive recording layer when the opaque cover sheet is peeled off, making it difficult to read the record. If the thickness of the polyolefin resin laminate layer is larger than this range, not only does the recording density decrease in pressure-sensitive printing, but also curling occurs, which is not preferable as a recording sheet.

By setting the center line average roughness defined by JIS B 0601-1982 on the side of the polyolefin resin laminate layer which is in contact with the curable resin layer to 0.2 to 12 μm, even if the opaque coated sheet is peeled, the peeling fog is reduced. Since a pressure-sensitive recording layer having no resin layer and a laminated surface having no resin layer remaining can be obtained, a pressure-sensitive recording sheet that is easy to read the record and has a beautiful appearance can be obtained. When the center line average roughness of the surface of the polyolefin resin laminate layer is smaller than this range, the polyolefin resin laminate layer is likely to be blocked at the time of production, and may develop color in the step of peeling the polyolefin resin laminate layer from the cooling roll. Although the reason is not clear, even if the same curable resin layer is provided, the releasability is poor, and color may be formed when the opaque cover sheet is peeled off. If the center line average roughness of the surface of the polyolefin resin laminate layer is larger than this range, uniform pressurization is not performed during recording, and it becomes difficult to read the recorded contents. Also, part of the curable resin layer may remain on the polyolefin resin laminate layer,
It is not preferable from the viewpoint of reading the recorded contents and also from the viewpoint of beauty.

As the support and the opaque cover 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 a synthetic paper laminated on one or both sides of paper, laminated paper, metal foil, or a bonded product of metal foil and paper, vapor-deposited paper, opaque sheet with hologram treatment,
Products bonded to a 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, dyes, inks, toners and the like.

As the curable resin layer used in the present invention, a non-thermoplastic curable resin, particularly a resin crosslinkable in a three-dimensional network structure, is suitably used. Curable (ultraviolet curable and electron beam curable) resins can be used. For example, curable resins include DFK resin, unsaturated polyester resin, alkyd resin, epoxy resin, bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, novolak type epoxy resin, silicone resin, vinyl ester resin, furan resin, diallyl Phthalate resin, maleic acid resin, melamine resin, urea resin, guanamine resin, various acrylates and methacrylates, phenolic resins, xylene resins, urethane elastomers,
Resin such as polyurethane resin alone or solution,
It can be used in the form of an aqueous solution or emulsion. The method of setting, curing and curing these adhesive resins is heat drying,
Any method such as thermal polymerization, ultraviolet curing, and electron beam curing may be used. Even if a resin has a strong adhesiveness, by incorporating a release agent such as a silicone resin, the adhesiveness can be appropriately reduced to function as a curable resin for the present application. The important requirements of the curable resin are that the opaque cover sheet and the polyolefin resin laminate layer can be bonded to each other at the time of curing due to cohesive force and the like, and that the opaque cover sheet can be peeled off thereafter, and that the cross-linking is performed three-dimensionally. It has a structure and does not have effective thermoplasticity at a temperature below the temperature at which the polyolefin resin laminate layer melts, that is, does not have effective heat sealing properties after curing. Coloring or opacity of the curable resin with a pigment or dye can be any problem.

For the purpose of preventing blocking, increasing viscosity and increasing the amount of the resin, an organic or inorganic pigment can be contained in the resin forming the curable resin layer. For example, kaolin, calcined kaolin, talc, limestone, diatomaceous Examples include soil, calcium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, titanium oxide, barium carbonate, urea-formalin resin, and plastic beads such as styrene.

The amount of the curable resin layer to be applied is not limited, but it is desired that the curable resin layer be thinner in order to avoid a reduction in writing pressure as much as possible, preferably 0.5 to 30 g / m ^2.
Or less, more preferably in the range of 1.0 to 20 g / m ² or less. The method of applying the resin for forming the curable resin layer of the present invention includes gravure roll and transfer roll coater, bar coater, roll coater, air knife coater, U comma coater, AKKU coater, smoothing coater, microgravure coater, reverse roll Any coater such as a coater, four or five roll coater, blade coater, dip coater, rod coater, kiss coater, gate roll coater, squeeze coater, drop curtain coater, slide coater, and die coater may be used.

For curing the curable resin of the present invention, for example, the following initiators can be used depending on the type of curing reaction. That is, benzoyl peroxide, dicumyl peroxide,
Cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, acetylene peroxide, lauroyl peroxide, p-menthane hydroperoxide, di-t-butyl diperphthalate, t-butyl perbenzoate, t-butyl peracetate, 2,4-dichlorobenzoyl peroxide,
Methyl ethyl ketone peroxide, hydroxyheptyl peroxide, cyclohexanone peroxide, 2,5
-Dimethylhexane-2,5-dihydroperoxide,
Azobisisobutyronitrile and the like. Binary initiators (redox initiators) include Fenton's reagent and combinations thereof with different metal species or peroxy compounds, benzoyl peroxide / dimethylaniline, cumene hydroperoxide / Fe ²⁺ salt, persulfate / NaHSO ₃ , cumene Hydroperoxide / vanadium compounds, cerium salts / alcohols, etc. Hydroperoxide / tertiary amine / sulfimide, peroxide / triethylaluminum, triethylboron, diethylzinc, etc. as an anaerobic curing initiator. Examples of photoinitiators in the case of performing ultraviolet curing include acetophenones such as di and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyldimethyl ketal, tetramethylthiuram monosulfide, thioxanthones, and azo compounds. is there. The amount of the initiator used is usually in the range of 0.1 to 10% based on the curable resin. Further, a storage stabilizer such as hydroquinone or a polymerization inhibitor may be used in some cases.

The pressure-sensitive recording sheet of the present invention may be provided with a color former layer or a developer layer or a color former layer or a developer layer on the surface (opaque coated sheet side), recording surface, polyolefin resin laminate layer side or back surface (support side). Both, protective coating layer, adhesive layer,
A curable resin layer, a release layer, a printing layer, a toner receiving layer, an ink receiving layer, a thermosensitive recording layer, a writing layer, a magnetic recording layer, and the like can be provided alone or simultaneously. Printing and recording methods include writing with pencils and inks, impact printers, electrophotography, thermal transfer, ink ribbons, heat sensitivity, pressure sensitivity, inkjet, flexographic printing, offset printing, gravure printing, letterpress printing, intaglio printing, laser printing, and labeling. There is no restriction by the method such as matching. In particular, in the pressure recording method, it is possible to cause only the front surface or the back surface to develop color by controlling the pressing force. Further, the pressure-sensitive recording sheet of the present invention, other pressure-sensitive recording sheet,
It can be used as a series of copy sheets in combination with a back carbon copy sheet, an adhesive sheet, a print sheet, a transparent film, and the like. Some or all of the recording sheet of the present invention, such as die cutting, separation of some opaque covering sheet,
Processing of perforations, feed holes for printers, etc. does not matter at all.

In the pressure-sensitive recording sheet of the present invention, the concealed recorded content of the pressure-sensitive recording may be readable when viewed from the front or back. Naturally, such transparency can be prevented by increasing the thickness of the support or the opaque covering sheet, or by providing a tint block print for preventing the transparency on the front or back surface. When the copy-forgery-inhibited pattern printing is provided or when the copy-forgery-inhibited pattern printing is provided, other printing cannot be performed on the copy-forgery-inhibited pattern printing portion, the recording surface is drastically reduced, and the appearance is not good.

As a means for solving such a problem, in the pressure-sensitive recording sheet according to the present invention, character printing or tint block printing is performed on a support or a pressure-sensitive recording layer, a polyolefin resin laminate layer, or an opaque cover sheet to be used. Can be used. In particular, providing a tint block print for preventing see-through on one side of the opaque covering sheet that is in contact with the curable resin layer, on one side of the opaque covering sheet that is not in contact with the curable resin layer, or on one side of the support that is not in contact with the pressure-sensitive recording layer is transparent. High prevention effect. Above all, when a see-through tint block print is provided on one side of the opaque cover sheet which is in contact with the curable resin layer, the see-through tint block print is performed only on the inner surface, so that the confidentiality of information is high and the opaque cover is provided. Since it is not necessary to perform tint block printing on the front side (that is, the front side of the pressure-sensitive recording sheet of the present invention) and the back side, the recording density can be increased, and the tint block printing and the internal pressure-sensitive coloring layer are close to each other. Therefore, the effect of preventing see-through is high, and it is possible to record information (address, advertisement, etc.) that may be exposed to the outside, which is also preferable from the viewpoint of beauty. In the present invention, in order to improve the adhesiveness and wettability, surface treatment such as corona treatment, ozone treatment, and flame treatment on the pressure-sensitive recording layer, the polyolefin resin laminate layer, and the opaque covering sheet may not be performed. No problem.

In the pressure-sensitive recording sheet of the present invention, the opaque cover sheet is provided with a developer or its microcapsules on one side of the opaque cover sheet which is not in contact with the curable resin layer (so-called pressure-sensitive paper). Is also good. When pressure-sensitive paper having a color developer layer on the surface of an opaque cover sheet is used, if pressure-sensitive printing is performed by superimposing the color-forming agent or its capsule on pressure-sensitive upper paper, it can be printed on the surface of the lower paper. Pressure sensitive recording can be performed with high accuracy. If you want to develop the color only on the internal pressure-sensitive recording layer, use a printer with an ink ribbon removed, a metal letterpress, or a resin letterpress to perform blank printing or crusher printing without using an upper paper, or print on the developer layer. By applying the desensitizing ink, it is possible to suppress color development on pressure-sensitive paper.

When the polyolefin resin laminate layer on the pressure-sensitive recording layer and the lower paper or thermal paper of the pressure-sensitive recording paper are integrated with the curable resin as the opaque cover sheet, depending on the type of the curable resin, the opaque cover sheet may be used. Infiltration of the curable resin occurs, depending on the type of curable resin, the developer of the pressure-sensitive paper or thermal paper desensitizes and inhibits the color development of the opaque cover sheet, or depending on the type of curable resin In some cases, the opaque cover sheet becomes slightly transparent, and the internal coloring record to be hidden may be seen through. Such a trouble not only hinders the interpretation of the recorded contents, but is also unfavorable in appearance, and significantly impairs the commercial value. Furthermore, even in the case of high-quality paper in which the opaque covering sheet does not have pressure-sensitive copying properties, the opacity of the opaque covering sheet is impaired by the curable resin, causing a problem in that the opaque covering sheet becomes transparent and the internal record can be read through. There is.

Furthermore, depending on the type of the curable resin, the curable resin penetrates into the opaque cover sheet in a state of being overlapped with the opaque cover sheet, and does not contribute to the adhesion between the opaque cover sheet and the polyolefin resin laminate layer, or substantially does not contribute to the adhesion. A small amount of coating did not have a sufficient cohesive force due to a small amount of the curable resin, and a part of the curable resin remained on the polyolefin resin laminate layer, hindering recording properties and deteriorating the appearance after peeling off the opaque cover sheet. . When a curable resin is applied sufficiently for adhesion, there is also a problem that the suitability for pressure-sensitive printing tends to deteriorate.

As a result of studying a method for solving the above-mentioned problems, as a result of providing an aqueous polymer intermediate layer on the side of the opaque covering sheet in contact with the curable resin layer, the curable resin permeates the opaque covering sheet. To reduce its opacity, or to reach the pressure-sensitive coloring layer, heat-sensitive layer, printing layer, etc. provided on the opposite surface (surface) of the opaque coated sheet, causing color fogging or deteriorating ink acceptability. It has been found that there is an effect that troubles such as causing trouble can be prevented beforehand. Furthermore, it is considered that the provision of the aqueous polymer intermediate layer on the surface of the opaque covering sheet that is in contact with the curable resin suppresses the seepage of the curable resin into the opaque covering sheet. A pressure-sensitive recording sheet that not only has good color developability even in the case of paper or heat-sensitive paper, but also has good adhesion of the opaque cover sheet even with a small amount of curable resin applied, and good pressure-sensitive printing suitability. Was obtained.

Examples of the aqueous polymer that can be used in the aqueous polymer intermediate layer of the present invention include the following substances. As natural polymers and semi-synthetic polymers, modified starch compounds such as starch, oxidized starch, etherified starch, dialdehyde starch, esterified starch, alginic acid compounds such as sodium alginate, propylene glycol alginate, casein, gelatin, pullulan Dextran, chitin, chitosan, gum latex, gum arabic, funori, natural gum, dextrin, modified cellulose compounds such as methylcellulose, ethylcellulose, hydroxycellulose and carboxymethylcellulose. As synthetic polymers, fully or partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, esterified product of polyvinyl alcohol and polyvalent carboxylic acid,
Carboxy-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, olefin-modified polyvinyl alcohol, nitrile-modified polyvinyl alcohol,
Amide-modified polyvinyl alcohol, modified polyvinyl alcohol compounds such as pyrrolidone-modified polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyacrylic acid, ammonium polyacrylate,
Examples include polyacrylic acid compounds such as sodium polyacrylate, polyvinylpyrrolidone, polyethyleneimine, polyvinyl ether, polymaleic acid copolymer, polyacrylamide, and water-soluble alkyd resins. Further, an aqueous polymer solution is prepared as an emulsion in which a synthetic polymer such as styrene / maleic anhydride copolymer, styrene / butadiene copolymer, butadiene / methacrylate copolymer, acrylonitrile / butadiene / acrylate latex is dispersed in water. It can be used instead. Emulsified general curable resins can also be used as the aqueous polymer, and can be cured by irradiation with an electron beam after drying. As the aqueous polymer, the above-described polymers can be used alone or as a mixed aqueous solution, if necessary, in combination with an antifoaming agent, a dispersant, and the like.

The coating amount of the aqueous polymer intermediate layer is not limited, but is preferably in the range of 1 to 5 g / m ² . If the coating amount is smaller than this range, the aqueous polymer intermediate layer may be uneven, and if it is larger than this range, it does not contribute to the improvement of the releasability and the permeation prevention property.

[0050]

In the pressure-sensitive recording sheet of the present invention, the curable resin that does not dissolve the polyolefin resin is sufficiently cured or cross-linked in the polyolefin resin laminate layer on the pressure-sensitive recording layer. Although the resin layer is adhered to the polyolefin resin laminate layer by a cohesive force or a light anchor effect, it can be separated (peeled) from the polyolefin resin laminate layer by a light force. The polyolefin resin laminate layer and the three-dimensionally cross-linked and solidified curable resin layer transmit the writing pressure almost without dispersing and absorbing, so that a high color density can be obtained at the time of pressure-sensitive recording, and the gloss of the printing surface can be obtained. Excellent in scratch resistance and friction resistance,
In addition, since the curable resin layer and the opaque covering sheet are provided on the polyolefin resin laminate layer, the pressure-sensitive recorded information can be disclosed to the outside and handled without being exposed, and if necessary, the opaque covering sheet can be used. By peeling, the information pressure-recorded inside can be read.

Further, since the curable resin layer of the present invention is a cross-linked resin having a three-dimensional network structure, it does not originally have heat sealability (exhibition of plasticity by heating) after being cured and cross-linked once. Therefore, the information once disclosed after peeling off the opaque covering sheet has a feature that it cannot be adhered or concealed again by means such as heating, pressurizing, or radiation (anti-adhesion property).

By having an aqueous polymer intermediate layer on the surface of the opaque covering sheet on the side in contact with the curable resin, the opaque covering sheet does not penetrate into the opaque covering sheet even when the curable resin comes into contact with the opaque covering sheet. Since it does not become transparent, it has a high opacity, and even when the lower sheet of pressure-sensitive coloring paper is used as the opaque cover sheet, the developer and the curable resin do not come into contact with each other, and as a result, it shows a high color developing property .

The appropriate thickness of the polyolefin resin laminate layer improves the gloss, scratch resistance and friction resistance of the printed surface without deteriorating the color developability of the pressure-sensitive recording layer, and improves the floating of the laminate layer when the opaque coated sheet is peeled off. And curling. By setting the center line surface roughness of the side of the polyolefin resin laminate layer in contact with the curable resin layer in an appropriate range, there is no release fog even when the opaque cover sheet is peeled off, and the curable resin layer remains on the laminate layer Thus, a pressure-sensitive recording layer which is easy to read and easy to read can be obtained.

[0054]

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 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N90, basis weight 90 g /
m ² ) was used. Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 17 μm using a melt extrusion die as a polyolefin resin laminate layer. Using an air knife coater as an aqueous polymer intermediate layer on the back surface of pressure-sensitive paper lower paper (Mitsubishi Paper, Mitsubishi NCR Super, N50, basis weight 50 g / m ² ) which is an opaque covering sheet having a developer layer. A 5% solution of cationized starch was applied to a dry weight of 1.2 g / m ² and dried. The following curable resin was applied on the polyolefin resin laminate layer with an offset gravure coater so as to be 10 g / m ² ,
After pre-curing at a temperature of ° C, the resultant was superposed on the aqueous polymer intermediate layer of the lower paper, heat-cured and crosslinked again at a temperature of 130 ° C, integrated, and humidified to obtain a desired pressure-sensitive recording sheet. Curable resin 95 parts of ethylene oxide-modified isocyanuric acid triacrylate (manufactured by Toa Gosei Chemical Co., Aronix M315) 5 parts of cumene hydroperoxide

Example 2 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N90, basis weight 90 g /
m ² ) was used. A low-density polyethylene (density: 0.918 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 20 μm using a melt extrusion die as a polyolefin resin laminate layer. Fine paper (Mitsubishi Paper, diamond form 53 g / m ² ) was used as the opaque covering sheet. The following curable resin was applied on the polyolefin resin laminate layer with an offset gravure coater so as to have a weight of 5.0 g / m ² , preliminarily dried and precured at 100 ° C., superimposed on the opaque coating sheet, and heated at 120 ° C.
To obtain a desired pressure-sensitive recording sheet. Curable resin 80 parts of thermosetting urethane elastomer (Coronate 4090, manufactured by Nippon Polyurethane Industry) 20 parts of methylenebischloroorthoaniline

Example 3 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N90, basis weight 90 g /
m ² ) was used. Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 10 μm using a melt extrusion die as a polyolefin resin laminate layer. Using high quality paper (Mitsubishi Paper, diamond form 53 g / m ² ) as the opaque covering sheet,
As an aqueous polymer intermediate layer, 2.0 g / m ² of 5% gelatin was applied using a Meyer bar, and after setting, it was dried by heating. The following curable resin is applied on the polyolefin resin laminate layer with an offset gravure coater so as to have a solid content of 13 g / m ² , preliminarily cured at 100 ° C., superposed with the aqueous polymer intermediate layer, and heated at 110 ° C. Furthermore, heat curing was carried out to integrate and control the humidity to obtain a target pressure-sensitive recording sheet. Curable resin Butylated urea melamine resin (Mitsubishi Toatsu Chemicals, Uban 132) 95 parts Acrylic resin (Mitsui Toatsu Chemicals, Almatex 781-27) 95 parts Xylol 200 parts Butanol 50 parts

Example 4 As the pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N90, basis weight 90 g /
m ² ) was used. Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 18 μm using a melt extrusion die as a polyolefin resin laminate layer. Using high quality paper (Mitsubishi Paper, diamond form 53 g / m ² ) as the opaque covering sheet,
As an aqueous polymer intermediate layer, 2.0 g / m ² of 5% gelatin was applied using a Meyer bar, and after setting, it was dried by heating. The following curable resin is applied on the polyolefin resin laminate layer with an offset gravure coater so as to have a solid content of 13 g / m ² , preliminarily cured at 100 ° C., superposed with the aqueous polymer intermediate layer, and heated at 110 ° C. Furthermore, heat curing was carried out to integrate and control the humidity to obtain a target pressure-sensitive recording sheet. Curable resin Polyphenol type melamine resin (oiled shell epoxy 1031) 95 parts Diethyltriamine 20 parts Dicyandiamide 5 parts Xylol 200 parts Butanol 50 parts

Example 5 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 17 μm using a melt extrusion die as a polyolefin resin laminate layer. The following curable resin is applied on the polyolefin resin laminate layer with an offset gravure coater so as to be 8 g / m ^2, and precured by UV irradiation (Ushio Electric, 120 w / cm, 2
And pressure-sensitive paper having a color developer layer on the pre-cured curable resin and the non-coated surface of pressure-sensitive paper under paper (Mitsubishi Paper, Mitsubishi NCR Super, N40, basis weight 40 g / m ² ) They were superposed, heat-cured at 100 ° C. and integrated to obtain the desired pressure-sensitive recording sheet. Curable resin Trimethylolpropane triacrylate 92 parts Irgacure 651 (manufactured by Ciba Geigy) 4 parts Benzoyl peroxide 4 parts

Example 6 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polyethylene (density: 0.918 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 17 μm using a melt extrusion die as a polyolefin resin laminate layer. The following curable resin is applied on the polyolefin resin laminate layer with an offset gravure coater so as to have a concentration of 12 g / m ^2, and after pre-drying, a pressure-sensitive paper having a developer layer on the curable resin layer is obtained. Lower paper (Mitsubishi Paper, Mitsubishi NCR Super lower, N40,
The non-coated surfaces having a basis weight of 40 g / m ² ) were overlapped, redox cured at room temperature at 40 ° C. and integrated to obtain a target pressure-sensitive recording sheet. Curable resin Dipentaerythritol hexaacrylate 75 parts N-vinyl-2-pyrrolidone 20 parts Benzoyl peroxide / dimethylaniline 5 parts

Example 7 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 18 μm using a melt extrusion die as a polyolefin resin laminate layer. The following curable resin is applied on the polyolefin resin laminate layer with an offset gravure coater so as to be 8 g / m ^2, and precured by UV irradiation (Ushio Electric, 120 w / cm, 2
And pressure-sensitive paper having a color developer layer on the pre-cured curable resin, and the uncoated surface of pressure-sensitive paper lower paper (manufactured by Mitsubishi Paper Mills, under Mitsubishi NCR Super, N50, basis weight 50 g / m ² ) The superposed and nitrogen-substituted electron beam irradiation device (Electron Curtain, manufactured by Energy Science Co., Ltd.) is introduced and irradiated with an electron beam at an electron beam acceleration voltage of 200 kV so that the absorbed dose becomes 3 Mrad to cure the curable resin. To obtain the desired pressure-sensitive recording sheet. Curable resin Pentaerythritol tetraacrylate 50 parts Ethylene oxide-modified noniphenol acrylate 46 parts Benzyl dimethyl ketal 4 parts

Comparative Example 1 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polyethylene (density: 0.918 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 17 μm using a melt extrusion die as a polyolefin resin laminate layer. Under paper of pressure-sensitive paper having a color developer layer as an opaque cover sheet (Mitsubishi Paper, Mitsubishi NCR
Polyethylene as a polyolefin resin (density: 0.1 g / m ² ) on the non-coated surface under supermarket, N50, basis weight 50 g / m ² .
918 g / cc) was laminated to 17 μm. The two pressure-sensitive recording sheets were heated at 100 ° C. until the two polyolefin resin laminate layers were stacked and pressed together to obtain a desired pressure-sensitive recording sheet.

Comparative Example 2 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 17 μm using a melt extrusion die as a polyolefin resin laminate layer. Fine paper (Mitsubishi Paper, 53 g / m ² diamond form) as an opaque cover sheet and polypropylene (density: 0.9 as a polyolefin resin)
(00 g / cc) was laminated to a thickness of 17 μm. Both polyolefin resin laminate layers were heated at 120 ° C. until they were integrated while being overlapped and pressed to obtain the desired pressure-sensitive recording sheet.

Comparative Example 3 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 17 μm using a melt extrusion die as a polyolefin resin laminate layer. 12 g of an acrylic adhesive resin (manufactured by Konishi, Bond CE753) on the laminate layer
m ² , and dried under pressure-sensitive paper having a developer layer as an opaque covering sheet (M50, manufactured by Mitsubishi Paper Mills, under Mitsubishi NCR Super, N50, basis weight 50 g / m ² ). The coated surface was overlaid on the adhesive surface, cured for 2 days and integrated to obtain the desired pressure-sensitive recording sheet.

Tests: Examples 1 to 7 and Comparative Examples 1 to 3
In the pressure-sensitive recording sheet obtained in (1), the lower sheet or the opaque cover sheet was not peeled off by printing, cutting, mailing, etc., and was sufficiently integrated. A sheet of commercially available pressure-sensitive recording paper was superimposed on the pressure-sensitive recording sheet, and the color form, printability, and recording exposure were evaluated as a copy slip. Table 1 shows the results.

[Lower Paper Color Test] When the lower paper is used, the color density of the lower paper of the pressure-sensitive recording sheet is recorded and printed by an impact printer equipped with an ink ribbon from above the upper paper. The paper was separated and the color development of the lower paper was measured. The color density was measured with a Macbeth reflection densitometer, and expressed as a relative value based on the color density of the lower sheet when the upper sheet and the lower sheet were simply overlapped and printed similarly.
If it is 90% or more, it is enough as a record.

[Internal color development test] The internal color density of each pressure-sensitive recording sheet was recorded and printed by an impact printer equipped with an ink ribbon from above the upper paper.
Thereafter, the lower paper or the opaque covering sheet was peeled off, and the internal color development was measured from above the polyolefin resin laminate layer. The color density is measured with a Macbeth reflection densitometer, and based on the color density of the self-coloring type pressure-sensitive recording paper before lamination,
Expressed as a relative value. 90% or more is sufficient for deciphering the record.

[Releasability] When the lower paper or the opaque covering sheet of each of the pressure-sensitive recording sheets is peeled off from the polyolefin resin laminate layer by hand, the lower paper or the opaque covering sheet can be peeled without being damaged. The releasability was excellent, and one in which a part of the paper layer was broken and remained on the polyolefin resin laminate layer was judged to be inferior in releasability.

[Background color development] The background color development on the internal pressure-sensitive recording surface of each of the pressure-sensitive recording sheets when the opaque cover sheet or the underlying paper was peeled off by hand was measured with a Macbeth densitometer. Based on the color density of the background at the stage where the polyolefin resin laminate layer was provided, comparable ones were excellent, slightly inferior but those that would not interfere with the determination of the recorded contents, Those with severe color development were evaluated as inferior.

[Secondness] A record printed by a printer by peeling off the opaque covering sheet of the obtained pressure-sensitive recording sheet is disclosed, and the opaque covering sheet is thermocompressed again (provided that the polyolefin resin layer is polypropylene). At a temperature of 152 ° C, which is 3 ° C lower than its melting point, 105 ° C which is 3 ° C lower than its melting point in the case of polyethylene or a mixed resin of polyethylene and polypropylene, and 210 ° C which is 25 ° C lower than its melting point in the case of polymethylpentene. heating)
Then, those that were re-adhered were inferior, and those that were not re-adhered were excellent.

[0071]

[Table 1]

Example 8 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 10 μm using a melt extrusion die as a polyolefin resin laminate layer. The cooling roll at the time of lamination was a mirror-finished roll used when preparing a support for glossy photographic printing paper, and the center line average roughness of the obtained polyolefin resin laminate layer was 0.2 μm. An alkyd resin (D6 manufactured by Hitachi Chemical Co., Ltd.)
34S, containing a methanol solution of p-toluenesulfonic acid as an initiator) with an offset gravure coater so as to have a concentration of 5 g / m ² , preliminarily drying by heating, and having a printed portion thereon as an opaque covering sheet. Basis weight 5
The cast coated paper of 0 g / m ² was overlaid, dried by heating and cured and crosslinked to obtain the desired pressure-sensitive recording sheet.

Example 9 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). On a pressure-sensitive recording surface, a mixed polyolefin resin composed of 10 parts of low-density polyethylene (density: 0.918 g / cc) and 90 parts of polypropylene (density: 0.900 g / cc) was used as a polyolefin resin laminate layer by using a melt extrusion die. Lamination was performed so that the thickness became 20 μm. The cooling roll at the time of lamination was a semi-mat roll used when preparing a support for semi-matte photographic printing paper, and the center line average roughness of the obtained polyolefin resin laminate layer was 2 μm. A trifunctional acrylate (available from Toagosei Chemical Industry Co., Ltd., an equivalent mixture of Aronix M310 and M320, containing 5% of benzyldimethyl ketal as a photoinitiator) as a curable resin thereon is offset gravure so as to have a concentration of 5 g / m ^2. After applying with a coater and pre-irradiating with an ultraviolet irradiation device, the grammage is 1
A 5 g / m ² tracing paper was superimposed and further irradiated with ultraviolet rays to cure and crosslink the curable resin, and then a woven pattern was printed on the tracing paper to make it opaque to obtain a desired pressure-sensitive recording sheet.

Example 10 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). 70 parts of low-density polyethylene (density: 0.918 g / cc) and 30 parts of high-density polyethylene (density: 0.965 g / cc) using a melt extrusion die as a polyolefin resin laminate layer on the pressure-sensitive recording surface.
The mixed olefin resin consisting of parts was laminated so as to have a thickness of 40 μm. The cooling roll at the time of lamination was a silk roll used for preparing a support for photographic printing paper on a silk surface, and the center line average roughness of the obtained polyolefin resin laminate layer was 8 μm. An alkyd resin solution (Merane 4 manufactured by Hitachi Chemical Co., Ltd.)
6D, a solvent butanol / xylene / methanol mixed solvent containing a methanol solution of p-toluenesulfonic acid as a reaction initiator) is applied by an offset gravure coater to a dry coating amount of 8 g / m ^2, and dried at 70 ° C. for 5 minutes. Thereafter, high-quality paper having a printed portion and a basis weight of 50 g / m ² was overlaid, cured for 24 hours and bonded to obtain a desired pressure-sensitive recording sheet.

Example 11 A commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100) was used as the pressure-sensitive recording paper.
g / m ² ). Polymethylpentene (TPX, Mitsui Petrochemical Co., Ltd.) was 40 μm on the pressure-sensitive recording surface using a melt extrusion die as a polyolefin resin laminate layer.
Were laminated. The cooling roll at the time of lamination was a gravure mat roll, and the center line average roughness of the obtained polyolefin resin laminate layer was 12 μm
Met. Equivalent amounts of a melamine resin (Mitsubishi Toatsu Chemicals, Uban 21R, mixed solvent of xylol / butanol) and an acrylic resin (Mitsui Toatsu Chemicals, Armatex D-152, mixed solvent of xylol / butanol) as the curable resin The mixture was applied with an offset gravure coater to a dry application amount of 10 g / m ² ,
After drying for minutes, a finely coated paper having a printed portion and a basis weight of 30 g / m ² was overlaid and heated at 100 ° C. to obtain a desired pressure-sensitive recording sheet.

Comparative Example 4 A pressure-sensitive recording sheet was obtained in the same manner as in Example 8 except that the center line average roughness was changed to 0.1 μm.

Comparative Example 5 A pressure-sensitive recording sheet was obtained in the same manner as in Example 9 except that the thickness of the polyolefin resin laminate layer was changed to 8 μm.

Comparative Example 6 A pressure-sensitive recording sheet was obtained in the same manner as in Example 10 except that the thickness of the polyolefin resin laminate layer was changed to 50 μm. This pressure-sensitive recording sheet was severely curled and developed color when printing was performed by a printer.

Comparative Example 7 A pressure-sensitive recording sheet was obtained in the same manner as in Example 11, except that the center line average roughness was changed to 14 μm.

Comparative Example 8 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 15 μm using a melt extrusion die as a polyolefin resin laminate layer. The cooling roll at the time of lamination was a mirror-finished roll used when preparing a support for glossy photographic printing paper, and the center line average roughness of the obtained polyolefin resin laminate layer was 0.2 μm. A polyolefin-based hot melt adhesive (Hamatite M470, manufactured by Yokohama Rubber Co., Ltd.) is applied to the back surface of a 50 g / m ² basis weight cast-coated paper having a printed portion as an opaque cover sheet, and a polyolefin resin laminate layer and a hot melt adhesive layer are applied. Were brought into contact with each other and subjected to a heat press to obtain a desired pressure-sensitive recording sheet.

Comparative Example 9 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 15 μm using a melt extrusion die as a polyolefin resin laminate layer. The center line average roughness of the obtained polyolefin resin laminate layer was 1.2 μm. On the polyolefin resin laminate layer, an ethylene-vinyl acetate copolymer heat-sealing adhesive (manufactured by Nogawa Chemical Co., Ltd., D
A946) is applied at a dry weight of 15 g / m ² and dried with hot air to obtain a basis weight of 50 having a printed portion as an opaque covering sheet.
g / m ² of the cast coated paper was overlaid and integrated to obtain the desired pressure-sensitive recording sheet.

Comparative Example 10 As a pressure-sensitive recording paper, a commercially available self-coloring type pressure-sensitive recording paper (manufactured by Mitsubishi Paper Mills, Diamond Self, Super N100, basis weight 100)
g / m ² ). Polypropylene (density: 0.900 g / cc) was laminated on the pressure-sensitive recording surface to a thickness of 15 μm using a melt extrusion die as a polyolefin resin laminate layer. The center line average roughness of the obtained polyolefin resin laminate layer was 1.2 μm. An adhesive emulsion resin (manufactured by Konishi Co., Bond 720) on a polyolefin resin laminate layer in a dry weight of 1
5 g / m ^{2 was} applied and dried with hot air, and a 50 g / m ² basis weight cast-coated paper having a printed portion as an opaque covering sheet was overlaid and integrated to obtain a target pressure-sensitive recording sheet.

Tests: Examples 8 to 11 and Comparative Examples 4 to
The pressure-sensitive recording sheet obtained in Example No. 10 was evaluated for color development, peel fog, curable resin layer residue, laminate layer floating, information recording exposure, and information recording confidentiality.
Table 2 shows the results.

[Coloring property] The coloring density of each pressure-sensitive recording sheet was determined by printing with a constant weight on the opaque coated sheet by an impact printer, and then peeling off the opaque coated sheet to expose the color printing surface. 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 90% or more were evaluated as excellent, 70% or more and less than 90%, and inferior values of less than 70%.

[Release fog] When the opaque cover sheet of the obtained pressure-sensitive recording sheet was peeled off by hand, the fog on the background of the pressure-sensitive recording layer was visually observed, and there was no color development on the background. The samples were evaluated as excellent, and those with slight background fogging but having no problem in reading the record were rated as good, and those with background fogging to some extent in the reading of the record were rated as poor.

[Residual Resin] Residual resin layer remains when the opaque cover sheet of the obtained pressure-sensitive recording sheet is peeled off by hand.
In the case where a part of the curable resin (in the case of the comparative example, an adhesive resin) was left on the polyolefin resin laminate layer, it was determined to be inferior, and in the case where no resin layer was left at all, it was determined to be excellent.

[Floating Laminate Layer] The floating of the laminate layer is determined by determining whether a part of the polyolefin resin laminate layer is peeled off from the pressure-sensitive recording layer when the opaque cover sheet of the obtained pressure-sensitive recording sheet is peeled off by hand. It was confirmed that the laminate was not peeled off from the pressure-sensitive recording layer at all, and the laminate was peeled to a certain degree that did not hinder the reading of the record. Was regarded as inferior.

[Exposure] When the record printed on the opaque cover sheet by the dot impact printer with the ink ribbon removed was not read as it is, it was regarded as excellent, and when it was readable, it was regarded as poor.

[Secondness] A record in which the opaque cover sheet of the obtained pressure-sensitive recording sheet was peeled off and printed by a printer was disclosed, and the opaque cover sheet was again heat-pressed (provided that the polyolefin resin layer was polypropylene). At a temperature of 152 ° C, which is 3 ° C lower than its melting point, 105 ° C which is 3 ° C lower than its melting point in the case of polyethylene or a mixed resin of polyethylene and polypropylene, and 210 ° C which is 25 ° C lower than its melting point in the case of polymethylpentene. heating)
Then, those that were re-adhered were inferior, and those that were not re-adhered were excellent.

[Adhesiveness] In each sample, in the printability test, the opaque coated sheet was excellent in the case where it was adhered without peeling in the degree of handling during printing, and the sample in which the adhesive strength was small such as displacement during printing. In addition, samples that were peeled and not adhered to the extent that the samples were cut were regarded as inferior.

[0091]

[Table 2]

Evaluation: The pressure-sensitive recording sheet obtained in the examples has good color developability of the lower sheet even when the lower sheet of pressure-sensitive paper is used as the opaque cover sheet, and peels off the opaque cover sheet. The opaque cover sheet is peeled off without any background fogging, no hardening resin layer remains on the polyolefin resin laminate layer, and no part of the polyolefin resin laminate layer peels off from the pressure-sensitive recording layer. In this case, the internal recording property was good, and the peeling property was not a problem. The pressure-sensitive recording sheet obtained in the examples uses a curable resin that cross-links and cures in a three-dimensional network, and such a resin does not exhibit heat sealability at a temperature equal to or lower than the melting point of the polyolefin resin. When the opaque covering sheet was peeled off, the cured curable resin did not adhere again to the polyolefin resin laminate layer. For this reason, the content of the pressure-sensitive recording is concealed by the opaque cover sheet, and the opaque cover sheet has a good peeling property, and has good confidential properties that it does not adhere again once it is peeled off and information is disclosed. Was something.

On the other hand, in the pressure-sensitive recording sheet prepared in the comparative example, the pressure at the time of the heat press caused the background color development to be sufficient for discrimination of the internal recording. Further, in the case of an adhesive resin which is not a curable resin, it is considered that the adhesive resin component is bleeding out. However, when the lower sheet of pressure-sensitive paper is used as the opaque cover sheet, the color development is not good. In addition, when the polyolefin resin laminate layer is thin or thick, the laminate layer floats or the color develops poorly. In addition, when the center line average roughness of the polyolefin resin laminate layer is too small, peeling fog occurs. When the center line average roughness is too large, the curable resin layer remains to cause difficulty in viewing and poor printability. In addition, in the case of bonding between thermoplastic resins, coloring by pressing occurs, or re-bonding is possible to the same degree as the original bonding, and the confidentiality is poor. When an adhesive resin, a hot-melt resin, a heat-sealing resin or the like which does not have a three-dimensionally crosslinked structure is used in place of the curable resin, re-adhesion by heating or pressurization was also possible, and the confidentiality was poor.

[0094]

According to the pressure-sensitive recording sheet of the present invention, the apparent adhesion between the opaque cover sheet and the polyolefin resin laminate layer can be achieved by curing the curable resin, and the surface releasability of the polyolefin resin laminate layer can be improved. The opaque covering sheet can be peeled off by utilizing this. The solidified curable resin layer adheres to the polyolefin resin laminate layer with cohesive force or a light anchor effect, but can be separated from the polyolefin resin laminate layer with a light force, and the curable resin layer is cross-linked for the purpose of three-dimensional netting . Since it is cured, it does not exhibit thermoplasticity and does not adhere again to the polyolefin resin laminate layer, and is excellent in confidentiality of information. Since the polyolefin resin laminate layer and the solidified curable resin layer transmit the pen pressure with little absorption, a high color density can be obtained during pressure-sensitive recording, and the gloss, scratch resistance, and friction resistance of the printed surface can be obtained. It has excellent curability, and has a curable resin layer and an opaque cover sheet on the polyolefin resin laminate layer, so that pressure-sensitive recorded information can be handled without being exposed and exposed to the outside. By peeling off the covering sheet, the information pressure-recorded inside can be read. The appropriate thickness of the polyolefin resin laminate layer improves the gloss, scratch resistance and friction resistance of the printed surface without deteriorating the color developability of the pressure-sensitive recording layer, suppresses the floating of the laminate layer, and suppresses the occurrence of curling. . By removing the opaque covering sheet by setting the center line surface roughness of the side of the polyolefin resin laminate layer in contact with the curable resin layer in an appropriate range, there is no peeling fog even when the opaque covering sheet is peeled off, and there is no curable resin layer residue. A pressure-sensitive recording layer that is easy to read and has a beautiful appearance can be obtained. The pressure-sensitive recording sheet of the present invention is a pressure-sensitive recording sheet having excellent coloring properties on the surface (lower sheet) of the pressure-sensitive recording sheet and capable of concealing printed contents, such as recording and communication when the contents are to be concealed. Is effective. As described above, the present invention is of great practical significance because it can be used for many purposes such as continuous slips, pasted slips, correspondence such as labels and postcards, recording, and dust-free recording paper.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a pressure-sensitive recording sheet showing an embodiment having an aqueous polymer intermediate layer of the present invention.

FIG. 3 is a cross-sectional view of a pressure-sensitive recording sheet showing an embodiment in which the opaque cover sheet of the present invention has a color developer layer.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41M 5/124

Claims (5)

(57) [Claims] In a pressure-sensitive recording sheet, the pressure-sensitive recording sheet is formed by laminating or mixing a color former or a developer, both or one of which is microencapsulated, on one side of a support, respectively. A laminated recording sheet in which a coated pressure-sensitive recording layer, a polyolefin resin laminate layer, a curable resin layer, and an opaque cover sheet are sequentially provided.
A pressure-sensitive recording sheet, which is a crosslinked resin having a three-dimensional network structure and does not exhibit heat sealability in a temperature range equal to or lower than the melting point of the polyolefin resin. 2. The JIS B of the polyolefin resin laminate layer having a thickness of 10 to 40 μm and the side of the polyolefin resin laminate layer in contact with the curable resin layer.
0601-1982, the center line surface roughness is
2. The pressure-sensitive recording sheet according to claim 1, wherein the thickness is 0.2 to 12 [mu] m (cutoff value: 0.8 mm, measurement length: 5 mm). 3. The pressure-sensitive recording sheet according to claim 1, wherein the opaque cover sheet has an aqueous polymer intermediate layer on the side in contact with the curable resin layer. 4. A so-called pressure-sensitive paper lower sheet in which a color developer or a microcapsule thereof is coated on one side of the opaque covering sheet which is not in contact with the curable resin layer, is a opaque covering sheet. The pressure-sensitive recording sheet according to claim 1. 5. The curable resin layer according to claim 1, wherein the curable resin layer is a curable resin layer cured by one or more curing methods selected from the group consisting of heat curing, redox room temperature curing, ultraviolet curing, and electron beam curing. Item 2. The pressure-sensitive recording sheet according to Item 1.