JP3005103B2 - Pressure-sensitive recording sheet and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive recording sheet, and more particularly, to an aqueous polymer intermediate layer, a silicone resin layer, and an adhesive layer on a single self-coloring type pressure-sensitive recording layer provided on a support. Layer, a pressure-sensitive recording sheet having a releasable property consisting of an opaque cover sheet, non-exposure of recording, water resistance, chemical resistance,
A pressure-sensitive recording sheet that can be used as a recording sheet for labels, slips, correspondence, amusement products, and clean rooms as a recording sheet having oil resistance, scratch resistance, and dust generation suppression properties.

[0002]

2. Description of the Related Art The pressure-sensitive recording layer used in the present invention is a self-coloring pressure-sensitive recording type, which has been developed from a so-called carbonless copying paper. Also called paper. The composition consists of a step of applying a coating of microcapsules containing a colorless dye (hereinafter referred to as a color forming agent) to a support, and an electron-accepting material such as acid clay, a phenol resin, and an organic acidic substance on the coating. A production method by two-layer coating (including a method in which the order of application is reversed) consisting of two steps and a step of applying a substance (hereinafter referred to as a color developer), or the above two components, or any one of the components. Manufacturing method by microencapsulation, uniform mixing and one layer coating
No. 7-16096). In such a self-coloring pressure-sensitive recording sheet, since a color former and a developer are present in the vicinity, a printed image with a high color density is easily obtained, but unintentional unintended undesired due to friction during production or handling. There is a problem that coloring stains easily occur.

The self-coloring pressure-sensitive recording sheet is destined to satisfy both the practically necessary coloring performance and the suppression of unnecessary coloring stains under the conditions in which it is used. Efforts are being made to satisfy both conflicting properties of dirt. Further, such self-coloring pressure-sensitive recording sheets are often used for attaching continuous slips to luggage or as backing paper, and therefore, simultaneously have water resistance, oil resistance, stain resistance, recording properties, and the like. It was extremely difficult to meet these requirements simultaneously. Furthermore, in a continuous slip, if one of them is used for lamination, the lower paper must be release paper, so that it is often used in the lowermost layer of the slip, and the color density is necessarily low. Was something. In such a configuration, a release paper of the same area is necessary. For example, not only is the release paper discharged in the case of performing continuous label sticking remarkably obstructive work, but generally, release paper is generally used. However, there is a problem in disposal because it cannot be regenerated, and in use, there is a problem that the combined thickness of the pressure-sensitive paper and the release paper increases. further,
In the self-coloring type pressure-sensitive recording sheet, the information that is pressure-sensitively recorded is highly open and inevitably exposed to the public.
If you wanted to hide the information, you had to put it in a separate bag.

Heretofore, for example, a method of providing a laminate layer by a vacuum adhesion method on a recording layer of a self-coloring pressure-sensitive recording sheet (Japanese Patent Publication No. 49-10857), or a recording method having a plastic layer by a melt lamination method Sheets (Japanese Utility Model Laid-Open No. 52-149709) and examples of providing a release layer on these protective layers are known. However, in practice, when a protective layer is provided by melt lamination or lamination, unnecessary color stains can be prevented, but only an unsatisfactory one that sacrifices the most necessary coloring performance is obtained. The fact was that it had not been done. Further, since these methods basically assume that the pressure-sensitive recording portion is exposed, the problem of non-disclosure of recording cannot be solved.

As another method, a method in which a soluble polymer solution is applied on a self-coloring type pressure-sensitive recording layer and dried to form a coating film can form a thin protective layer.
Disruption of the microcapsules causes remarkable color fogging or the resin covers the microcapsules, almost losing the original self-coloring pressure-sensitive recording properties, and lowering both the color density and the color developing speed, which is not satisfactory. .

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pressure-sensitive recording sheet which does not sacrifice its original color developing property, reduces color fogging due to friction, and at the same time has a water resistance and oil resistance. Another object of the present invention is to provide a pressure-sensitive recording sheet which satisfies the requirements of, for example, contamination resistance and, if necessary, has the non-disclosure of information.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found the following method. That is, the present inventors have developed a pressure-sensitive recording layer and an aqueous polymer intermediate layer in which microcapsules containing at least one of a color former and a developer are individually laminated or mixed and applied. , A polydialkylcyclohexane molecular compound having at least one of an acryloyl group, a methacryloyl group, and an epoxy group introduced into a terminal or a side chain of the molecular main chain is a type of high energy ray composed of ultraviolet rays or electron beams. A pressure-sensitive recording sheet characterized by sequentially providing a silicone resin layer, an adhesive layer, and an opaque cover sheet cured as described above, and at least one of a color former and a developer on one surface of the support. Providing a pressure-sensitive recording layer for individually laminating or mixing and applying microcapsules, providing an intermediate layer for applying an aqueous polymer solution on the recording layer, A step of applying a silicone resin thereon, and providing a silicone resin layer for curing the silicone resin with one or more kinds of high energy rays composed of ultraviolet rays or electron beams, and applying an adhesive on the silicone resin layer or on one surface of an opaque covering sheet. The invention of a method for producing a pressure-sensitive recording sheet, characterized by producing a pressure-sensitive recording sheet by a step of providing an adhesive layer to be applied, and a step of integrating an opaque cover sheet and a silicone resin layer via the adhesive layer, was found. . Note that the silicone resin layer may contain an inorganic pigment.

In the pressure-sensitive recording sheet of the present invention, the silicone resin provided on the recording surface does not seep into the pressure-sensitive recording layer due to the action of the aqueous polymer intermediate layer, and has a surface releasability with a small amount of silicone resin. High color density can be obtained as it is. The silicone resin itself exhibits high water resistance as well as releasability from the adhesive layer, and the aqueous polymer intermediate layer exhibits high oil resistance. Further, when a label composed of an opaque cover sheet and an adhesive layer is used as a label, release paper is unnecessary, so that not only is there a cost advantage, but also unnecessary release of release paper is not required. Since the silicone resin layer also serves as an overcoat layer, the superposed thickness is reduced, and a high color density can be obtained during pressure-sensitive recording, and the printed surface has excellent gloss, scratch resistance, and friction resistance. Since the adhesive layer and the opaque covering sheet are provided on the release layer, the pressure-sensitive recorded information can be handled without being exposed and exposed to the outside. Pressure-sensitive information can be read.

The details of the present invention will be described below. As the support used in the pressure-sensitive recording sheet of the present invention, and as the opaque covering sheet, general papers such as glassine paper, woodfree paper, art paper, coated paper and cast paper can be used, and wood pulp, synthetic pulp, Raw materials usually used in papermaking, such as fillers, sizing agents, paper strength agents, dyes, etc., can be used as needed. Also, polyethylene,
Polypropylene, polyethylene terephthalate, plastic sheets such as polyamide, and synthetic paper or nonwoven fabric made of these synthetic fibers, or synthetic resin on one side of paper,
Alternatively, laminated paper, metal foil, or metal foil and paper, metallized paper, an opaque sheet subjected to hologram treatment, a laminated product of a synthetic resin film, mica paper, glass paper, and the like can also be used. These plastic sheets and synthetic resins can be made opaque with inorganic or organic pigments.

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, an oil for dissolving the color former, a color developer, an adhesive, a microcapsule protective agent, and 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.). Etc. can be used.

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

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

Examples of oils for dissolving the color former include aromatic synthetic oils such as diarylalkanes, alkylnaphthalenes, alkylated biphenyls and hydrogenated terphenyls, and aliphatic synthetic oils such as kerosene, naphtha, paraffin oil and chlorinated paraffin. Vegetable oils such as oil, cottonseed oil, soybean oil, and linseed oil can be used.

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

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

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

The pigment used in the pressure-sensitive recording layer, aqueous polymer intermediate layer, or silicone 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 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, 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.

According to 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, 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 Providing an undercoat layer containing a finely divided organic pigment such as a polymer, polymethyl methacrylate, a urea / formaldehyde polymer, or polyethylene can be used without any problem.

An intermediate layer comprising an aqueous polymer can be provided between the pressure-sensitive recording layer and the silicone resin layer. The aqueous polymer mentioned here includes, for example, the following substances.

Examples of natural polymers and semi-synthetic polymers include modified starch compounds such as starch, oxidized starch, etherified starch, dialdehyde-modified starch, and esterified starch; alginic acid compounds such as sodium alginate and propylene glycol alginate; casein;
Examples include gelatin, pullulan, dextran, chitin, chitosan, gum latex, gum arabic, funori, natural gum, dextrin, modified cellulose compounds such as methylcellulose, ethylcellulose, hydroxycellulose, carboxymethylcellulose, and the like. Synthetic polymers include 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, and olefin-modified Modified polyvinyl alcohol compounds such as polyvinyl alcohol, nitrile-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, pyrrolidone-modified polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyacrylic acid, ammonium polyacrylate, sodium polyacrylate, etc. Polyacrylic acid compound, polyvinylpyrrolidone, polyethyleneimine, polyvinylether, polymaleic acid copolymer, polyacrylamide, Such as soluble alkyd resins. It is not an aqueous polymer in a strict sense, but styrene /
Use of an emulsion in which a synthetic polymer such as maleic anhydride copolymer, styrene / butadiene copolymer, butadiene / methacrylate copolymer, acrylonitrile / butadiene / acrylate latex is dispersed in water instead of the aqueous polymer solution. Can be. As an aqueous polymer,
The above-mentioned polymers can be used alone or as a mixture to form an aqueous solution, and if necessary, an antifoaming agent, a dispersant and the like can be used in combination.

The silicone resin release agent for forming the silicone resin layer used in the present invention may be a silicone resin (mainly polydimethylsiloxane) or a solution thereof.
It is an aqueous emulsion, preferably a silicone resin that is cured by heating, ultraviolet light or electron beam,
In addition, various silicone compounds having the same function, fluorine compounds, compounds containing a long-chain alkyl group, and the like can be used. The ultraviolet or electron beam curable silicone resin is a resin in which an acryloyl group or a methacryloyl group is introduced into a terminal or a side chain of a molecular main chain of a general silicone resin, and is a silicone-containing acrylate, a silicone-containing methacrylate or a derivative thereof. . Product names are FM0711, FM0721, FM0725, PS58
3 (above, Chisso Corporation), KP-600, X-62-
7100, X-62-7112, X-62-7140,
X-62-7144, X-62-7153, X-62-
7157, X-62-7158, KNS-5200, X
-62-7166, X-62-7168, X-62-7
177, X-62-7180, X-62-7181, X
-62-7192, X-62-7200, X-62-7
203, X-62-7205, X-62-7931 (above, Shin-Etsu Chemical Co., Ltd.), RC149, RC300, RC
450, RC802, RC710, RC720 (or more,
Goldschmidt), EBECRYL350, EB
ECRYL1360 (these are Daicel UCB Co., Ltd.) and the like. Further, acrylates or methacrylates containing a long-chain alkyl group and silicone-modified compounds thereof are also good ultraviolet or electron beam curable release agents. These can be used alone or in combination of two or more. In addition, these silicone resins have the purpose of increasing the surface strength of the silicone resin layer,
Or for the purpose of improving curability, a general ultraviolet curable resin as a curing aid, or an electron beam curable resin,
They can be mixed and used within a range that does not excessively affect the peel strength.

Typical examples of the radiation-curable resin used in the present invention include: (1) polyester acrylate and polyester methacrylate, for example, Aronix M-5300, Aronix M-
5400, Aronix M-5500, Aronix M
-5600, Aronix M-5700, Aronix M-6100, Aronix M-6200, Aronix M-6300, Aronix M-6500, Aronix M-7100, Aronix M-8030, Aronix M-8060, Aronix M-8100 (or more, Toa Gosei Chemical Industry Co., Ltd.), Viscort 70
0, Viscoat 3700 (trade name of Osaka Organic Chemical Industry Co., Ltd.), Kayarad HX-220, and Kayarad HX-620 (trade name of Nippon Kayaku Co., Ltd.).

(2) Urethane acrylate, urethane methacrylate, for example, Aronix M-1100, Aronix M-
1200, Aronix M-1210, Aronix M
-1250, Aronix M-1260, Aronix M-1300, Aronix M-1310 (all trade names of Toagosei Chemical Industry Co., Ltd.), Biscoat 812, Biscoat 823, Biscoat 823 (all products of Osaka Organic Chemical Industry Co., Ltd.) Name), NK ester, U-108-A,
NK ester and U-4HA (all trade names of Shin-Nakamura Chemical Co., Ltd.).

(3) Monofunctional acrylate, monofunctional methacrylate, vinylpyrrolidone, acryloyl compound, acrylamide compound For example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate,
Cyclohexyl methacrylate, acryloyl morpholine, benzyl acrylate, glycidyl methacrylate, N, N-dimethylaminoethyl acrylate, N,
N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, butoxyethyl acrylate, vinylpyrrolidone, acrylamide ether compounds and the like. Ethylene oxide-modified phenoxylated phosphoric acid acrylate Ethylene oxide-modified butoxylated phosphoric acid acrylate, as well as Alonix M-101 and Aronix M-
102, Aronix M-111, Aronix M-1
13, Aronix M-114, Aronix M-11
7, Aronix M-152, Aronix M-154
And the like.

(4) Polyfunctional acrylate, polyfunctional methacrylate, for example, 1,6-hexanediol diacrylate,
1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, pentaerythritol diacrylate, dipentaerythritol hexaacrylate, Isocyanuric acid diacrylate, pentaerythritol triacrylate, isocyanuric acid triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene oxide-modified pentaerythritol tetraacrylate, propylene oxide-modified pentaerythritol tetraacrylate, propylene Oxide modified dipentaerythritol polyacrylate, ethylene oxide-modified dipentaerythritol polyacrylate, such acrylate esters of pentaerythritol acrylate adduct. Speaking of trade names of Toa Gosei Chemical Industry Co., Ltd., Aronix M-210, Aronix M-215, Aronix M-220, Aronix M-230, Aronix M-233, Aronix M-240, Aronix M-245, Aronix M -305, Aronix M
-309, Aronix M-310, Aronix M-
315, Aronix M-320, Aronix M-3
25, Aronix M-330, Aronix M-40
0, Aronix M-450, TO-458, TO-7
47, TO-755, THIC. TA2 and the like. These can be used alone or in combination of two or more.

The photoinitiators used in the present invention, particularly when using the ultraviolet curing method, include acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyldimethyl ketal, There are methylthiuram monosulfide, thioxanthones, azo compounds, and the like, which are selected from the viewpoint of the type of polymerization reaction of the radiation-curable resin, stability, and suitability for an ultraviolet irradiation device. The amount of the photoinitiator to be used is usually O.O. It is in the range of 1-5%. A storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

In order to prevent blocking, an organic or inorganic pigment can be added to the resin forming the silicone resin layer. For example, kaolin, calcined kaolin, talc, limestone, diatomaceous earth, calcium carbonate, water Examples include aluminum oxide, magnesium hydroxide, magnesium carbonate, titanium oxide, barium carbonate, urea-formalin resin, and plastic beads such as styrene.

The coating amount of the silicone resin layer and the coating amount of the aqueous polymer intermediate layer are not limited, but are preferably thinner in order to avoid a drop in writing pressure, preferably from 0.2 to 10 g. / M ² or less, more preferably 0.
It is within the range of 5 to ³ g / m ² or less. Examples of the method of applying the resin for forming the silicone resin layer and the intermediate layer of the present invention include a gravure roll and a transfer roll coater, a bar coater, a roll coater, an air knife coater, a U comma coater, an AKKU coater, a smoothing coater, a microgravure coater, Air knife coater, reverse roll coater, 4 or 5 roll coater, blade coater, dip coater,
Any coater such as a bar coater, a rod coater, a kiss coater, a gate roll coater, a squeeze coater, a falling curtain coater, a slide coater, and a die coater may be used.

Examples of the adhesive used in the present invention include acrylic resin, natural and synthetic rubber, styrene / butadiene copolymer, polyvinyl acetate, vinyl acetate / ethylene copolymer, starch, silicone-based compound, glue, casein, Resins such as polyvinyl alcohol, polyurethane, and polyurethane can be used alone or in the form of a solution, an aqueous solution, or an emulsion. As a method for setting these adhesives, any method such as heat drying, hot melt, ultraviolet curing, and electron beam curing may be used. In addition, depending on the amount of the adhesive applied, the drying / curing method, or the type, after preparing the pressure-sensitive recording sheet of the present invention, the opaque cover sheet and the adhesive layer may be peeled off and attached to another substance such as a label. Alternatively, a function of preventing adhesion (against re-adhesion) even if an attempt is made to adhere again to the silicone resin layer once peeled off can be imparted.

In the pressure-sensitive recording sheet according to the present invention,
Character printing or tint block printing can be used on these supports or on a pressure-sensitive recording layer, an aqueous polymer intermediate layer, a cured silicone resin layer, or an opaque cover sheet. Further, in the present invention, in order to improve the adhesiveness and the wettability, the surface may be subjected to a surface treatment such as a corona treatment.

The pressure-sensitive recording sheet of the present invention has a color former layer or a developer layer, a protective coating layer, an adhesive layer, a release layer, a printing layer, a toner receiving layer, and an ink receiving layer on the surface or the back surface. ,
The heat-sensitive recording layer, the writing layer, the magnetic recording layer and the like can be provided alone or simultaneously. The pressure-sensitive recording sheet of the present invention can be used as a series of copy sheets in combination with other pressure-sensitive recording sheets, back carbon copy sheets, adhesive sheets, printing sheets, transparent films, and the like.

As the ultraviolet irradiation device used in the present invention,
For example, there are a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and the like, and an ozone-less type that generates less ozone. Generally, a plurality of lamps having an output of 30 w / cm or more are used in parallel.

The electron beam irradiation used in the present invention is performed by using an electron beam accelerator having an acceleration voltage of 100 to 1000 KV, more preferably 100 to 300 KV, in view of transmission power and curing power.
It is preferable that the absorbed dose in one pass be 0.5 to 20 Mrad. If the acceleration voltage or the amount of electron beam irradiation is lower than this range, the electron beam transmission power is too low to perform sufficient curing, and if it is higher than this range, not only does the energy efficiency deteriorate, but also the resin, Undesirable effects on quality such as decomposition of additives and reduction in strength of base paper appear.

The electron beam accelerator may be, for example, any of an electron curtain system, a scanning type, a double scanning type and the like. In the electron beam irradiation step, the overcoat layer can be cured while a surface shape thereof is transferred by closely attaching a synthetic resin film, a metal foil, a metal drum, or the like to the overcoat layer.

When irradiating with an electron beam, if the oxygen concentration is high, the curing of the electron beam-curable resin is hindered.
Replace with an inert gas such as helium or carbon dioxide and reduce the oxygen concentration to 600 ppm or less, preferably 400 ppm.
The irradiation is preferably performed in an atmosphere controlled as follows.

[0039]

In the pressure-sensitive recording sheet, the silicone resin does not seep into the pressure-sensitive recording layer due to the function of the aqueous polymer intermediate layer, and a high color density can be obtained while maintaining surface releasability. In addition, since a release paper is unnecessary, there is a cost advantage. Since the silicone resin layer also functions as an overcoat layer, the thickness of the superposed layer is reduced, so that a color can be formed at a good recording density during pressure-sensitive recording, and gloss and water resistance can be obtained. It has excellent adhesiveness, chemical resistance, and scratch resistance, and has an adhesive layer and a coating layer on a release layer, so that pressure-sensitive information can be handled without being disclosed or exposed to the outside.

[0040]

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.

Preliminary Operation (Preparation of Self-Coloring Pressure-Sensitive Recording Layer) A microcapsule containing a color former used for the pressure-sensitive recording layer was prepared as follows. First, 10 parts of crystal violet lactone was heated and dissolved in 90 parts of Hisol SAS N-296 (manufactured by Nippon Petrochemical Co., Ltd.) to obtain an internal phase oil. Melamine 10 parts and 37%
25 parts of formalin were heated together with 100 parts of water at pH 8 to obtain a melamine-formalin initial polycondensate. Next, the internal phase oil was emulsified in 150 parts of a 5% aqueous solution of styrene / maleic anhydride copolymer, and the above-mentioned melamine-formalin polycondensate was added to this emulsion, and the liquid temperature was raised to 70 ° C.
After holding for a time, a microcapsule dispersion liquid containing a coloring agent having a melamine-formalin resin film was obtained. The average particle size of the obtained microcapsules was about 6 μm.

A coating for the self-coloring pressure-sensitive recording layer was prepared according to the following formulation. The unit is parts by dry weight. Microcapsules containing a color former 110 parts Developer (PR26298 manufactured by Sumitomo Durez Co., Ltd.) 60 parts Starch particles 280 parts Kaolin clay 70 parts Oxidized starch 100 parts

The self-coloring pressure-sensitive recording sheet was produced as follows. That is, a self-coloring pressure-sensitive recording layer having the above composition was applied to a high-quality paper having a basis weight of 40 g / m ^{2 so} that the coating amount was 8 g / m ² , to obtain a self-coloring pressure-sensitive recording sheet.

Example 1 A 7% mixture of formaldehyde as a hardener and an air knife coater as an aqueous polymer intermediate layer was formed on the recording surface of the self-coloring pressure-sensitive recording sheet prepared in the preliminary operation.
A gelatin solution was applied and dried and hardened after setting. An ultraviolet-curable silicone resin (KNS5300, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied thereon with a reverse roll coater to a concentration of 0.6 g / m ² , and an ultraviolet irradiation device (Rapid, manufactured by USHIO INC.) Cure). Further, as an adhesive, an adhesive resin IRR84 of Rad Cure Specialties (5.
(Including Irgacure 651% by weight) with an offset gravure coater so as to be 10 g / m ^2, and cured by irradiation with ultraviolet rays.
A target pressure-sensitive recording sheet was obtained by superimposing 0 g / m ² of cast-coated paper.

Example 2 On the recording surface of the self-coloring pressure-sensitive recording sheet prepared in the preliminary operation, 20% by weight of calcium carbonate (made of Shiraishi calcium, Whiten SB) was used as an aqueous polymer intermediate layer using an air knife coater. The mixed 10% polyvinyl alcohol solution was applied and dried. An electron beam-curable silicone resin (trade name: X-62-71, manufactured by Shin-Etsu Chemical Co., Ltd.)
92) with a 5-roll roll coater at 0.6 g / m ²
And introduced into an electron beam irradiator (Nissin High Voltage, Curetron) to apply an electron beam accelerating voltage of 20
It was cured by electron beam irradiation at 0 kV and an absorbed dose of 3 Mrad. Furthermore, a pressure sensitive adhesive (Toyo Ink, BPS8170)
Was applied with a comma coater so as to be 10 g / m ^2, and dried, and a high-quality paper having a basis weight of 40 g / m ² was overlaid as an opaque covering sheet to obtain a target pressure-sensitive recording sheet.

Example 3 A 4% polyethylene glycol solution as an aqueous polymer intermediate layer was applied to the recording surface of the self-coloring pressure-sensitive recording sheet prepared in the preliminary operation using an air knife coater and dried by heating. A silicone resin emulsion (trade name: KM763, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied thereon with a blade coater to a dry weight of 0.6 g / m ^2, and dried by heating.
Further, a urethane acrylate resin (Aronix M1 manufactured by Toa Gosei Chemical Industry Co., Ltd.)
A 7: 3 mixed resin of 210 and M115) is applied by a comma coater so as to be 10 g / m ^2, and a coated paper having a basis weight of 60 g / m ² is overlapped as an opaque covering sheet. High voltage, Curetron)
And cured by irradiation with an electron beam at an electron beam acceleration voltage of 200 kV and an absorbed dose of 3 Mrad to obtain a target pressure-sensitive recording sheet.

Comparative Example 1 The self-coloring pressure-sensitive recording sheet obtained by the preliminary operation was used for evaluation without providing a silicone resin layer.

COMPARATIVE EXAMPLE 2 A thermosetting silicone resin solution (trade name KL, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the self-coloring pressure-sensitive recording sheet obtained by the preliminary operation.
-838) and a low-temperature curable platinum catalyst (CATPL-
8) 1% is mixed, and the solid content is 0.6 g with a gravure roll.
/ M ² and heat-cured with a hot air circulating dryer at 100 ° C. Further, an adhesive (BPS8170, manufactured by Toyo Ink Co., Ltd.) was further applied thereon with a comma coater at 10 g / m ^2.
And coated as an opaque covering sheet with a basis weight of 40
g / m ² of high quality paper was overlaid to obtain the desired pressure-sensitive recording sheet.

Comparative Example 3 On the recording surface of the pressure-sensitive recording sheet prepared in the preliminary operation,
Using a polyethylene melt laminator, low density polyethylene (density 0.918 g / cm ³ , melt index 7) is laminated at the minimum coating thickness (approximately 7 μm) that can be produced continuously, and a thermosetting silicone 1% of a low-temperature curable platinum catalyst (trade name CAT PL-8) is mixed with a resin (trade name: KL-838, manufactured by Shin-Etsu Chemical Co., Ltd.), and coated with a gravure roll so as to have a solid content of 0.6 g / m ^2. , Thermosetting with a hot air circulating dryer at 60 ° C, and an adhesive (BPS8170, manufactured by Toyo Ink)
Is applied with a comma coater so as to be 10 g / m ² ,
A high-quality paper having a basis weight of 40 g / m ² was overlapped as an opaque covering sheet to obtain a target pressure-sensitive recording sheet.

Tests: Examples 1-3 and Comparative Examples 1-3
Of the pressure-sensitive recording sheet obtained in Example 2 were evaluated for color density, color developing speed, printability, friction resistance, oil resistance, and water resistance. Table 1 shows the results.

[Coloring Density] The coloring density of each pressure-sensitive recording sheet is determined by applying a constant weight from above the opaque covering sheet, and then peeling off the opaque covering sheet to expose the color printing surface. It was measured with a meter. Based on the color density of the self-coloring type pressure-sensitive recording sheet prepared in the preliminary operation, relative values of 90% or more were excellent, relative values of 70% or more and less than 90% were inferior, and values of less than 70% were inferior.

[Coloring speed] The coloring speed was determined by giving superiority or inferiority depending on the coloring condition at the time of the above color density test. When the opaque cover sheet was immediately peeled off after the pressurization, the case where the record was sufficiently legible was regarded as excellent, and the case where it took more than 2 minutes to read it was regarded as poor.

[Friction Resistance] The rub resistance was determined by rubbing the surface of the opaque coated sheet of each pressure-sensitive recording sheet lightly with steel wool, peeling the opaque coated sheet, and determining the coloring of the recording surface. The case where there was no obstacle due to friction at all on the recording surface was excellent, the case where coloring due to a few lines of friction was recognized, and the case where there was an obstacle due to friction enough to hinder reading or the case where the record could not be read was inferior.

[Oil resistance and water resistance] Oil resistance and water resistance were measured by dropping one drop of xylene or water on the recording surface with the opaque cover sheet of each pressure-sensitive recording sheet peeled off. Judgment was made based on the time of seepage to the back side.

[Printability] When printed from the top of an opaque cover sheet using a dot impact printer without an ink ribbon attached, excellent results are obtained when the printed characters are clearly printed without any cuts, and the printed characters are cut. The case was inferior.

[Exposure] In the printability test, a record printed by a printer was evaluated as excellent when it could not be read as it was, and poor when it could be read.

[0057]

[Table 1]

Evaluation: The pressure-sensitive recording sheets obtained in Examples 1 to 3 did not generate color fogging due to friction and were water resistant compared to the self-coloring pressure-sensitive recording sheet (Comparative Example 1). , Oil resistance, printability, color density,
The color development speed was comparable to that of the self-coloring pressure-sensitive recording sheet, and the content of the pressure-sensitive recording could be hidden by the opaque covering sheet. The opaque covering sheet had good peelability and could be used as a label if necessary.

On the other hand, as a comparison, when no aqueous polymer intermediate layer obtained in Comparative Examples 2 and 3 was used, or when a polyolefin laminate intermediate layer was used, color development was hindered and printability was poor. There was an obstacle that was bad. In the case of the self-coloring pressure-sensitive recording sheet having no opaque covering sheet (Comparative Example 1), it is obvious that not only are there problems in water resistance, oil resistance, and abrasion resistance, but there is no concealment of the recording. .

[0060]

According to the pressure-sensitive recording sheet of the present invention, the silicone resin provided on the recording surface does not seep into the pressure-sensitive recording layer due to the function of the aqueous polymer intermediate layer, and the surface releasability is reduced by a small amount of silicone resin. High color density can be obtained while maintaining the color density. The silicone resin itself exhibits high water resistance, and the aqueous polymer intermediate layer exhibits high oil resistance. Further, since a release paper is unnecessary, not only is there a cost merit when used as a label, but also there is no need to discharge unnecessary release paper. Since the silicone resin layer also serves as an overcoat layer, the thickness of the superposed layers is reduced,
Colors can be formed at a good recording density during pressure-sensitive recording, and the printed surface has excellent gloss, scratch resistance, and friction resistance. Can be handled without being exposed to the public, and the opaque covering sheet can be peeled off as necessary to read the pressure-sensitive recorded information. As described above, the present invention is for continuous slips, pasting slips, labels,
It is of great industrial significance, and can be used for many purposes such as correspondence such as postcards, recording, and dust-free recording paper.

Claims (2)

(57) [Claims] 1. A pressure-sensitive recording layer in which microcapsules containing at least one of a color former and a developer are individually laminated or mixed and applied on one side of a support, A high molecular energy layer consisting of an ultraviolet ray or an electron beam of a silicone compound in which at least one of an acryloyl group, a methacryloyl group, and an epoxy group is introduced into the molecular intermediate layer or the terminal or side chain of the molecular main chain of polydialkylcyclohexane. A pressure-sensitive recording sheet comprising a silicone resin layer, an adhesive layer, and an opaque coating sheet cured by at least one of the following. 2. A step of providing, on one surface of a support, microcapsules containing at least one of a color former and a developer alone, respectively, or providing a pressure-sensitive recording layer to be mixed and applied. Providing an intermediate layer for applying an aqueous polymer solution on the recording layer, applying a silicone resin on the intermediate layer, and curing the silicone resin with at least one kind of high energy ray composed of ultraviolet rays or electron beams Providing a pressure-sensitive adhesive layer on the silicone resin layer or on one side of the opaque cover sheet,
A method for producing a pressure-sensitive recording sheet, comprising producing a pressure-sensitive recording sheet by a step of integrating an opaque cover sheet and a silicone resin layer via an adhesive layer.