JPH05254241A - Pressure-sensitive recording sheet and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] To manufacture a pressure-sensitive recording sheet in which recorded contents are hidden. [Structure] A pressure-sensitive recording layer, an acryloyl group or acrylamide coated on one side of a support, which is coated with microcapsules containing at least one of a color-developing agent and a color-developing agent, which are individually laminated or mixed. A pressure-sensitive recording sheet having an aqueous polymer intermediate layer containing a compound having a group, a silicone resin layer having an acryloyl group at the terminal or side chain, an adhesive layer, and an opaque coating sheet, or a method for producing the same. [Effect] Information can be recorded in the internal pressure-sensitive recording portion by applying pressure from the opaque coating sheet, and the opaque coating sheet can be used as a label that does not require release paper. The water-based polymer intermediate layer and the silicone resin layer improve oil resistance and water resistance, and improve the adhesion and adhesiveness between the water-based polymer intermediate layer and the silicone resin.

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, in which an aqueous polymer intermediate layer, a silicone resin layer, an adhesive layer are provided on a single-form self-coloring type pressure-sensitive recording layer provided on a support. Is a pressure-sensitive recording sheet having a layer and an opaque covering sheet, which has releasability, and has non-exposure of recording, water resistance, chemical resistance,
A pressure-sensitive recording sheet that can be used as a recording sheet of a type having oil resistance, scratch resistance, and dust generation suppressing ability, 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 so-called carbonless copying paper. Also called paper. Its composition is the process of applying a coating of microcapsules containing a colorless dye (hereinafter referred to as a color former) on a support, and the electron-accepting property of acid clay, phenol resin, organic acid substances, etc. on the coating. Conveniently the process of applying a substance (hereinafter referred to as a color developer), a manufacturing method by two-layer coating consisting of two steps (including one in which the coating order is reversed), the above two components, or any one component Manufacturing method by microencapsulation, uniform mixing, and single layer coating (Japanese Patent Publication No.
No. 7-16096) is known. In such a self-coloring pressure-sensitive recording sheet, since a color former and a color developer are present in the vicinity, it is easy to obtain a printed image with high color density, but unintentional and unintentional due to friction during manufacturing or handling. There is a problem that colored stains are likely to occur.

The self-coloring pressure-sensitive recording sheet is destined to satisfy both the practically required coloring performance and the suppression of unnecessary coloring stains under the conditions under which it is used. Efforts are being made to satisfy both conflicting properties of dirt. Further, such a self-coloring pressure-sensitive recording sheet is often used for sticking continuous slips to luggage or as a lower sheet, and therefore, water resistance, oil resistance, stain resistance, recordability, etc. are simultaneously achieved. It was extremely difficult to meet these requirements at the same time as required. Further, in a continuous slip, when one of them is used for pasting, the lower paper must be a release paper, so that it is often used in the lowest layer in the slip structure, and thus the color density is inevitably low. It was a thing. In such a configuration, release paper having the same area is required. For example, the release paper discharged when labels are continuously applied not only significantly disturbs the work, but also the release paper is generally used. However, there is a problem in that it cannot be recycled, and therefore there is a problem in that the thickness of the pressure sensitive paper and the release paper becomes thick when used. further,
In the self-coloring type pressure-sensitive recording sheet, the pressure-sensitive information is inevitably exposed to the public,
If you wanted to hide the information content, you had to put it in a separate bag.

Up to now, for example, a method of providing a laminating layer by a vacuum adhesion method on the recording layer of a self-coloring pressure-sensitive recording sheet (Japanese Patent Publication No. Sho 49-10857) or a recording having a plastic layer by a melt laminating method. Sheets (Japanese Utility Model Laid-Open No. 52-149709) and examples of providing a release layer on these protective layers are known. However, in reality, when a protective layer is provided by fusion lamination or laminating, unnecessary color stains can be prevented, but only unsatisfactory results are obtained at the expense of the originally required color development performance. It was the actual situation that was not 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 of coating a soluble polymer solution on a self-coloring type pressure-sensitive recording layer and drying it to form a coating film can form a thin protective layer,
When the microcapsules are destroyed, remarkable color fog is generated, or the microcapsules are covered with resin, and the original self-coloring pressure-sensitive recording property is almost lost, and both the color density and the color developing speed are reduced, which is not satisfactory. ..

The present applicants have previously developed a pressure-sensitive recording sheet that reduces color fog caused by friction and, at the same time, satisfies water resistance, oil resistance, stain resistance, and the like, and, if necessary, does not disclose information. In order to obtain the above, a pressure-sensitive recording sheet having a structure in which a silicone layer coating is provided via an aqueous polymer intermediate layer was proposed. There is a problem that the adhesion and the adhesiveness of the layer may not be sufficient, the silicone layer alone may fall off (lab-off), or the peeled opaque coating sheet may have reduced adhesiveness.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to reduce the color fog caused by friction in a pressure-sensitive recording sheet without sacrificing its original color developability, and at the same time, it is resistant to water and oil. To provide a pressure-sensitive recording sheet that satisfies the requirements of stain resistance, stain resistance, and the like, and, if necessary, does not disclose information, and has excellent adhesion and adhesion of the silicone release layer to the support. It is in.

[0008]

The inventors of the present invention have made the following inventions as a result of earnest research for solving the above-mentioned problems. That is, microcapsules containing at least one of a color former and a color developer are individually laminated or mixed and applied, and a pressure-sensitive recording layer, an aqueous polymer intermediate layer, a silicone resin layer, an adhesive layer A pressure-sensitive recording sheet, which comprises a layer and an opaque coating sheet in that order, wherein the aqueous polymer intermediate layer contains a compound having an acryloyl group or an acrylamide group, and the silicone resin layer contains polydialkylsiloxane molecules. Invention of a pressure-sensitive recording sheet obtained by curing a silicone compound having an acryloyl group introduced at the terminal or side chain of the main chain with at least one kind of high-energy rays consisting of ultraviolet rays or electron beams, or a method for producing the same Is. The compound having an acryloyl group or an acrylamide group used in the present invention is preferably water-soluble or water-dispersible. The silicone resin used in the present invention is preferably a silicone resin having at least one functional group selected from an acryloyl group, a methacryloyl group and an epoxy group introduced at the terminal or side chain of the molecular main chain of polydialkylsiloxane. Alternatively, an inorganic pigment may be included.

In the pressure-sensitive recording sheet of the present invention, the silicone resin provided on the recording surface does not soak 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. As it is, a high color density can be obtained. The silicone resin itself exhibits not only releasability from the adhesive layer but also high water resistance, and the aqueous polymer intermediate layer exhibits high oil resistance. The compound having an acryloyl group or an acrylamide group contained in the aqueous polymer intermediate layer binds to the silicone resin in the step of curing the silicone resin to improve the adhesion and the adhesiveness between the aqueous polymer intermediate layer and the silicone resin layer. Improves and prevents the silicone resin layer from falling off from the support (rub-off), and prevents a decrease in the adhesive force due to the transfer of the silicone layer to the adhesive layer.
Further, when a label comprising an opaque coating sheet and an adhesive layer is used, release paper is not required, which is not only cost-effective but also unnecessary discharge of release paper. Since the silicone resin layer also serves as an overcoat layer, the thickness of the layers laminated becomes thin, high color density can be obtained during pressure-sensitive recording, and the gloss, scratch resistance, and abrasion resistance of the printed surface are excellent. Since it has an adhesive layer and an opaque coating sheet on the release layer, the pressure-sensitive recorded information can be handled without being exposed or exposed to the outside, and by peeling the opaque coating sheet as necessary, the internal You can read the information pressure-sensitively recorded.

The details of the present invention will be described below. The present invention is characterized in that an intermediate layer made of an aqueous polymer containing a compound having an acryloyl group or an acrylamide group is provided between the pressure-sensitive recording layer and the silicone resin layer. Examples of the aqueous polymer mentioned here include the following substances.

As natural 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 and propylene glycol alginate, casein,
Examples thereof include modified cellulose compounds such as gelatin, pullulan, dextran, chitin, chitosan, gum lattex, gum arabic, funori, natural gum, dextrin, methylcellulose, ethylcellulose, hydroxycellulose and carboxymethylcellulose. As the synthetic polymer, completely saponified or partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, esterification products of polyvinyl alcohol and polyvalent carboxylic acid, carboxy modified polyvinyl alcohol, sulfonic acid modified polyvinyl alcohol, olefin modified Modified polyvinyl alcohol compounds such as polyvinyl alcohol, nitrile modified polyvinyl alcohol, amide modified polyvinyl alcohol, pyrrolidone modified polyvinyl alcohol, polyethylene glycol, polyacrylic acid amide, polyacrylic acid, ammonium polyacrylate, sodium polyacrylate, etc. Polyacrylic acid compound, polyvinylpyrrolidone, polyethyleneimine, polyvinyl ether, polymaleic acid copolymer, polyacrylamide, Such as soluble alkyd resins. In addition, styrene /
Use an emulsion in which synthetic polymers such as maleic anhydride copolymer, styrene / butadiene copolymer, butadiene / methacrylate copolymer, acrylonitrile / butadiene / acrylic acid latex, etc. are dispersed in water instead of the aqueous polymer solution. You can As an aqueous polymer,
The above polymers may be used alone or as a mixture to form an aqueous solution, and if necessary, a defoaming agent, a dispersant and the like may be used in combination.

Typical examples of the compound having an acryloyl group contained in the aqueous polymer layer are shown below.

(1) Polyester acrylate For example, Aronix M-5300, Aronix M-
5400, Aronix M-5500, Aronix M
-5600, Aronix M-5700, Aronix M-6100, Aronix M-6300, Aronix M-6500, Aronix M-7100, Aronix M-8030, Aronix M-8060, Aronix M-8100 (above, Toa Gosei Chemical Industry ( Co., Ltd.), VISCOAT 700, VISCOAT 3700 (above, Osaka Organic Chemical Industry Co., Ltd. product name), Kayarad HX
-220, Kayarad HX-620 (above, trade name of Nippon Kayaku Co., Ltd.), emulsions thereof, and the like.

(2) Urethane Acrylate For example, Aronix M-1100, Aronix M-
1200, Aronix M-1210, Aronix M
-1250, Aronix M-1260, Aronix M-1300, Aronix M-1310 (above, product name of Toa Gosei Chemical Industry Co., Ltd.), Viscoat 812, Viscoat 823, Viscoat 823 (above, product of Osaka Organic Chemical Industry Co., Ltd.) Name), NK ester, U-108-A,
Examples thereof include NK ester, U-4HA (above, trade name of Shin-Nakamura Chemical Co., Ltd.), and emulsions thereof.

(3) Monofunctional acrylate, vinylpyrrolidone, acryloyl compound, acrylamide compound For example, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-
Hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, acryloylmorpholine, benzyl acrylate, N, N-dimethylaminoethyl acrylate, butoxyethyl acrylate, vinylpyrrolidone, acrylamide ether compounds and the like. Ethylene oxide-modified phenoxyphosphoric acid acrylate, ethylene oxide-modified butoxylated phosphoric acid acrylate, and other product names of Toagosei Kagaku Kogyo Co., Ltd. are Aronix M-101, Aronix M-102, Aronix M-111, Aronix M-. 113, Aronix M-114, Aronix M-117, Aronix M-152, Aronix M-154, and BR-170, M-580, TP-1124 or emulsions thereof in the trade name of Material Science. Be done.

(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. The product names of Toagosei Chemical Industry Co., Ltd. are 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, emulsions of these and the like can be mentioned.

These may be used alone or as a mixture of two or more. Further, it is more preferably water-soluble or water-dispersible.

The silicone resin release agent for forming the silicone resin layer used in the present invention is a silicone resin (mainly polydimethylsiloxane) or a solution thereof.
An aqueous emulsion, preferably a silicone resin that is cured by heating, ultraviolet rays or electron beams,
Besides, 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 at the terminal or side chain of the molecular main chain of a general silicone resin, and is a silicone-containing acrylate, a silicone-containing methacrylate or a derivative thereof. .. The product names are FM0711, FM0721, FM0725, PS58
3 (above, Chisso Corporation), KP-600, X-62-
7100, X-62-7112, X-62-7140,
X-62-1144, X-62-1153, X-62-
7157, X-62-1158, KNS-5200, X
-62-7166, X-62-7168, X-62-7
177, X-62-7180, X-62-7181,
X-62-1192, X-62-1200, X-62-
7203, X-62-7205, X-62-7931
(Above, Shin-Etsu Chemical Co., Ltd.), RC149, RC300,
RC450, RC802, RC710, RC720 (above, Goldschmidt company), EBECRYL350,
EBECRYL1360 (above, Daicel UCB
Ltd.) and the like. Furthermore, acrylates or methacrylates containing long-chain alkyl groups and their silicone-modified compounds are also good ultraviolet or electron beam curable release agents. These can be used alone or in combination of two or more. For the purpose of increasing the surface strength of the silicone resin layer or improving the curability of these silicone resins, a general ultraviolet curable resin or electron beam curable resin may be used as a curing aid to improve the peel strength. It can be used by mixing within a range that does not exert an excessive influence on.

For the purpose of preventing blocking, organic or inorganic pigments can be contained in the resin forming these silicone resin layers. For example, kaolin, calcined kaolin, talc, wax, diatomaceous earth, calcium carbonate, water. Examples thereof 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 for the purpose of avoiding a decrease in writing pressure, and preferably 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 for applying the resin forming the silicone resin layer and the intermediate layer of the present invention include a gravure roll and transfer roll coater, a bar coater, a roll coater, an air knife coater, a U comma coater, an AKKU coater, a smoothing coater, and a micro gravure 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 or a die coater may be used.

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, benzyl dimethyl ketal and tetra. There are methyl thiuram monosulfides, thioxanthones, azo compounds and the like, which are selected from the viewpoints of the type of polymerization reaction of the radiation curable resin, stability, suitability with an ultraviolet irradiation device, and the like. The amount of the photoinitiator used is usually 0. It is in the range of 1 to 5%. In addition, a storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

The ultraviolet irradiation device used in the present invention is as follows:
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 there is an ozoneless 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 has an accelerating voltage of 100 to 1000 KV, more preferably an electron beam accelerator of 100 to 300 KV, in terms of penetrating power and curing power.
It is preferable that the absorbed dose in one pass is 0.5 to 20 Mrad. If the accelerating voltage or the electron beam irradiation dose is lower than this range, the electron beam penetrating power is too low to perform sufficient curing, and if it is higher than this range, not only the energy efficiency deteriorates, but also the resin, There are unfavorable effects on quality such as decomposition of additives and reduction of strength of base paper.

The electron beam accelerator may be, for example, an electro curtain system, a scanning type, a double scanning type or the like. Further, in the electron beam irradiation step, the synthetic resin film, metal foil, metal drum or the like may be brought into close contact with the overcoat layer to cure the overcoat layer while transferring the surface shape thereof.

During electron beam irradiation, if the oxygen concentration is high, the curing of the electron beam curable resin is hindered, so nitrogen,
Oxygen concentration is less than 600ppm, preferably 400ppm by replacing with inert gas such as helium and carbon dioxide.
Irradiation is preferably performed in an atmosphere suppressed below.

As the support and the opaque coating sheet used in the pressure-sensitive recording sheet of the present invention, general paper such as glassine paper, high-quality paper, art paper, coated paper, cast paper and the like can be used, wood pulp, Raw materials commonly used in papermaking, such as synthetic pulp, fillers, sizing agents, paper strengthening agents, and dyes, can be used as necessary.
In addition, plastic sheets such as polyethylene, polypropylene, polyethylene terephthalate, and polyamide, and synthetic paper or non-woven fabric made of these synthetic fibers, or a laminated paper, a metal foil, or a metal foil laminated with a synthetic resin on one side or both sides It is also possible to use paper, vapor-deposited paper, an opaque sheet that has been subjected to a hologram treatment, a laminated product with a synthetic resin film, mica paper, glass paper and the like. 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 any conventionally known one can be used. For example, a method of microencapsulation, a wall material of the microcapsule, a color former, an oil 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 (US Pat. No. 2,800,458), an interfacial polymerization method (Japanese Patent Publication No. 47-1763, etc.), an in situ polymerization method (Japanese Patent Publication No. 51-9079, etc.). Etc. can be used.

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

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

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

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

Pigments used in the pressure-sensitive recording layer, the aqueous polymer intermediate layer, or the silicone resin layer include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, Examples thereof include silicon oxide, aluminum hydroxide, urea-formalin resin and the like.

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

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

Further, 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 in 1) can be added as needed.

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, 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, polyvinyltoluene, styrene / divinylbenzene There is no problem in providing an undercoat layer containing fine organic pigments such as polymers, polymethylmethacrylate, urea / formaldehyde polymers, and polyethylene.

The adhesive used in the present invention includes acrylic resins, natural and synthetic rubbers, styrene / butadiene copolymers, polyvinyl acetate, vinyl acetate / ethylene copolymers, starches, silicone compounds, glue, casein, Resins such as polyvinyl alcohol, polyurethane and polyurethane can be used alone or in the form of solution, aqueous solution or emulsion. As a method of setting these pressure-sensitive adhesives, any method such as heat drying, hot melt, ultraviolet curing, electron beam curing may be used. In addition, after the pressure-sensitive recording sheet of the present invention is prepared, the opaque coating sheet and the pressure-sensitive adhesive layer are peeled off, and the pressure-sensitive adhesive sheet is adhered to another substance like a label depending on the amount of the pressure-sensitive adhesive applied, the drying / curing method or the type. Alternatively, a function of not adhering (re-adhesion prevention) to the silicone resin layer once peeled can be imparted.

In the pressure-sensitive recording sheet according to the present invention,
The support, the pressure-sensitive recording layer, the aqueous polymer intermediate layer, the cured silicone resin layer, or the opaque coating sheet can be used by printing characters or a tint block. In the present invention, in order to improve the adhesiveness and wettability, the surface may be subjected to surface treatment such as corona treatment.

The pressure-sensitive recording sheet of the present invention has, on the front surface or the back surface thereof, 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. ,
A heat-sensitive recording layer, a writing layer, a magnetic recording layer and the like can be provided alone or simultaneously. Further, the pressure-sensitive recording sheet of the present invention can be used as a series of copy sheets in combination with other pressure-sensitive recording sheets, back carbon copying sheets, adhesive sheets, printing sheets, transparent films and the like.

[0042]

In this pressure-sensitive recording sheet, the silicone resin does not soak into the pressure-sensitive recording layer due to the action of the aqueous polymer intermediate layer, and a high color density can be obtained with surface releasability. Further, when the silicone resin layer is cured, a compound having an acryloyl group or an acrylamide group contained in the aqueous polymer intermediate layer and a silicone resin terminal or side chain acryloyl group are chemically bonded to each other. , Improves the adhesion and adhesion between the aqueous polymer intermediate layer and the silicone resin layer, prevents the silicone resin layer from falling off from the support (lab-off), and reduces the adhesive strength due to the transfer of the silicone layer to the adhesive layer. Can be prevented. Furthermore, there is no cost for release paper, and the silicone resin layer also serves as an overcoat layer, so the thickness of the layer is thin and the color can be developed at a good recording density during pressure-sensitive recording. Since it has excellent properties, chemical resistance, and scratch resistance, and has an adhesive layer and a coating layer on the release layer, it is possible to handle information that has been pressure-sensitive recorded to the outside without exposing or exposing it.

[0043]

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 by weight. Also,
Unless otherwise stated, the value indicating the smear amount is the smear amount after drying.

Preliminary Operation (Preparation of Self-Coloring Pressure-Sensitive Recording Layer) Microcapsules containing a color-forming agent used in the pressure-sensitive recording layer were 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 was heated together with 100 parts of water to obtain a melamine-formalin initial polycondensate. Then, the internal phase oil was added to a 5% aqueous solution of styrene / maleic anhydride copolymer 150.
Emulsified into a part, and the above melamine-formalin polycondensation product is added to this emulsion and the liquid temperature is kept at 70 ° C. for 2 hours to obtain a microcapsule dispersion liquid containing a color former having a melamine-formalin resin film. Got The average particle size of the obtained microcapsules was about 6 μm.

The coating material for the self-coloring pressure-sensitive recording layer was prepared by the following formulation. The unit is dry parts by weight. Microcapsules containing 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 prepared as follows. That is, a self-coloring pressure-sensitive recording sheet was obtained by coating a self-coloring pressure-sensitive recording layer having the above composition on a wood free paper having a basis weight of 40 g / m ^{2 so} that the coating amount was 8 g / m ² .

Example 1 An aqueous polymer intermediate layer containing an acryloyl group was coated on the recording surface of a self-coloring pressure-sensitive recording sheet prepared in a preliminary operation using an air knife coater according to the following formulation,
It was prepared by drying after setting. Formaldehyde 1 part Gelatin 7 parts UV-curable emulsion (GX-8434B manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 10 parts Water 82 parts After drying, reverse 5 UV-curable silicone resins (Shin-Etsu Chemical Co., Ltd., trade name KNS5300) A roll coater applied 0.6 g / m ² and the coating was performed with an ultraviolet irradiation device (Rapid Cure, manufactured by USHIO INC.). Further thereon, 10 g / m of an adhesive resin IRR84 (containing 5% by weight of Irgacure 651 as a reaction initiator) manufactured by Rad Cure Specialties Co., Ltd. as an adhesive agent.
Apply with an offset gravure coater to be ² ,
After curing by irradiation with ultraviolet rays, cast coated paper having a basis weight of 50 g / m ² was superposed as an opaque coating sheet to obtain a target pressure-sensitive recording sheet.

Example 2 An aqueous polymer intermediate layer having an acrylamide group was coated on the recording surface of a self-coloring pressure-sensitive recording sheet prepared in a preliminary operation using an air knife coater according to the following formulation,
It was made by drying. Calcium carbonate (manufactured by Shiraishi Calcium, Whiten SB) 5 parts 10% polyvinyl alcohol solution 20 parts Electron beam curable monomer (BR170 manufactured by Material Science Co., Ltd.) 5 parts Water 70 parts After drying, electron beam curable silicone resin ( Shin-Etsu Chemical Co., Ltd., trade name X-62-7192) was coated on 5 rolls with a reverse roll coater to 0.6 g / m ² and introduced into an electron beam irradiation device (Nisshin High Voltage, Curetron). Then, an electron beam accelerating voltage of 200 kV and an absorbed dose of 3 Mrad were applied to cure the electron beam. Furthermore, an adhesive (BPS8170, manufactured by Toyo Ink Co., Ltd.) on top of it was applied with a comma coater at 10 g /
m ² and so as coated and dried to obtain the desired pressure-sensitive recording sheet by superimposing high-quality paper having a basis weight 40 g / m ² as an opaque cover sheet.

Example 3 A self-color-developing pressure-sensitive recording sheet prepared in a preliminary operation was coated with an aqueous polymer intermediate layer according to the following formulation using an air knife coater and dried. 48% styrene / butadiene copolymer latex 10 parts Electron beam curable emulsion (DARR UCB Co., Ltd. IRR114) 10 parts Water 80 parts After drying, silicone resin emulsion (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KM763) with a blade coater. It was applied so as to have a dry weight of 0.6 g / m ^2, and dried by heating. Acrylic emulsion type adhesive, Bond C
E753 (manufactured by Konishi Co., Ltd.) in a dry solid content of 10 g /
After coating so as to be m ² , it is dried, and then coated paper having a basis weight of 60 g / m ² is superposed as an opaque coating sheet,
After curing for 2 days, a target pressure-sensitive recording sheet was obtained.

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

Comparative Example 2 A pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that the ultraviolet curable emulsion was not mixed in the aqueous polymer intermediate layer.

Comparative Example 3 A thermosetting silicone resin solution (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KL) was applied to a self-coloring pressure-sensitive recording sheet obtained in a preliminary operation.
-838) is a low temperature curing platinum catalyst (trade name CATPL-
8%) was mixed with 1% and the solid content was 0.6 g with a gravure roll.
/ M ² and then heat-cured with a hot air circulation dryer at 100 ° C. Furthermore, an adhesive (manufactured by Toyo Ink, BPS8170) was applied on top of it with a comma coater at 10 g / m ²
So that the opaque coating sheet has a basis weight of 40
A target pressure-sensitive recording sheet was obtained by superimposing g / m ² of high-quality paper.

Comparative Example 4 On the recording surface of the pressure-sensitive recording sheet prepared in the preliminary operation,
Using a polyethylene melt laminator, a low-density polyethylene (density 0.918 g / cm ³ , melt index 7) is laminated at the lowest coating thickness (about 7 μm) that can be continuously produced, and a thermosetting silicone is laminated thereon. A resin (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KL-838) was mixed with 1% of a low temperature-curable platinum catalyst (trade name CAT PL-8) and coated with a gravure roll so that the solid content was 0.6 g / m ^2. , Heat-cured in a hot air circulation dryer at 60 ° C, and then adhesive (Toyo Ink, BPS8170)
Is applied with a comma coater to 10 g / m ^2, and
A target pressure-sensitive recording sheet was obtained by stacking 40 g / m ² basis weight high-quality paper as an opaque coating sheet.

[Test] Examples 1 to 3 and Comparative Examples 1 to 4
The color-developing density, rub-off, printability, and exposure of the pressure-sensitive recording sheet obtained in 1. were evaluated. The respective results are shown in Table 1.

[Coloring Density] The coloring density of each pressure-sensitive recording sheet is determined by applying a constant weight from the top of the opaque covering sheet, and then peeling off the opaque covering sheet to expose the color printed surface, and the coloring density is determined by the Macbeth reflection density. 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, 90% or more in relative value was excellent, 70% or more and less than 90% was average, and less than 70% was inferior.

[Lub-off] The rub-off was judged by rubbing the silicone release layer of the pressure-sensitive recording sheet at the stage where the respective silicone release layers were provided with a finger and rubbing the silicone release layer with superiority or inferiority. The case where no dropout was observed was rated as excellent, and the case where it was observed was rated as poor. However, Comparative Example 1
Since no silicone release layer is provided, is not evaluated.

[Residual Adhesion Rate] The residual adhesion rate was determined by the method described below. The pressure-sensitive recording sheet before the provision of each pressure-sensitive adhesive layer was allowed to stand for 24 hours in a thermo-hygrostat at 20 ° C. and a relative humidity of 65%, and then pressure-sensitive adhesive sheet (knit tape No. 31B was used with a pressure roller of 2000 g). , Nitto Denko Co., Ltd., and pressure was applied for 24 hours under the conditions of 20 ° C., relative humidity of 65%, and pressure of 0.1 kg / cm ² . After peeling the adhesive sheet from the pressure-sensitive recording sheet, attach it to a 1.5 mm thick stainless steel plate with a well-polished surface and weigh 2
Pressure bonded with a pressure roller of 000g, 20 ℃, relative humidity 65
% In a thermo-hygrostat for 1 hour and then continuously peeled off with a Tensilon universal testing machine at a peeling angle of 180 ° and a peeling speed of 30 cm / min. It is determined as the peel strength A of the adhesive sheet. Next, a pressure-sensitive adhesive sheet was attached to a 1.5 mm thick stainless steel plate with a well-polished surface, and the temperature was 20 ° C., the relative humidity was 65%, and the pressure was 0.1.
Pressure was applied for 24 hours under the condition of kg / cm ² . After returning to normal pressure, press it with a pressure roller with a weight of 2000g,
After leaving for 1 hour in a thermo-hygrostat at ℃ and relative humidity of 65%, peeling angle 180 °, peeling speed 30c with Tensilon universal testing machine
The load when continuously peeled under the condition of m / min is determined as the peel strength B of the pressure-sensitive recording sheet which is not in contact with the pressure-sensitive recording sheet. The residual adhesion rate R (%) is R (%) = (A / B) × 1
00, less than 80% inferior, 80% to 90%
Less than was shown as average, and 90% or more was shown as excellent.

[Oil resistance and water resistance] Oil resistance and water resistance were measured by dropping one drop of xylene or water on the recording surface in a state where the opaque coating sheet of each pressure-sensitive recording sheet was peeled off. It was judged by the time it took to penetrate to the back side.

[Printability] When a dot impact printer not equipped with an ink ribbon is used to print twice on an opaque coating sheet, the colored characters can be clearly printed without breaks. When there was a break, it was considered inferior.

[Exposure] In the test of the printability, the case where the record printed by the printer could not be read as it was was judged as excellent, and the case where it could be read was judged as poor.

[0061]

[Table 1]

[Evaluation] The pressure-sensitive recording sheets obtained in Examples 1 to 3 were free from color fog due to rubbing and color density as compared with the self-coloring pressure-sensitive recording sheet (Comparative Example 1). The printability 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 coating sheet. The opaque coated sheet had good peelability and could be used as a label if necessary. Also, the adhesion between the silicone release layer and the aqueous polymer intermediate layer,
It had excellent adhesiveness and did not cause rub-off of the silicone release layer.

On the other hand, as a comparison, the pressure-sensitive recording sheet obtained in Comparative Example 2 containing no acryloyl group-containing compound in the aqueous polymer intermediate layer had insufficient rub-off properties and residual adhesiveness. It was

Further, as a comparison, when the aqueous polymer intermediate layer obtained in Comparative Examples 3 and 4 is not used or when the polyolefin laminate intermediate layer is used, color development is impaired and printability is poor. There was an obstacle. In the case of the self-coloring pressure-sensitive recording sheet having no opaque coating sheet (Comparative Example 1), it is obvious that not only there are problems in water resistance, oil resistance and abrasion resistance but also there is no hiding of recording. ..

[0065]

In the pressure-sensitive recording sheet of the present invention, the silicone resin provided on the recording surface does not soak into the pressure-sensitive recording layer due to the action of the aqueous polymer intermediate layer, and the surface releasability is improved by a small amount of silicone resin. It is possible to obtain a high color density as it is. The silicone resin itself exhibits high water resistance, and the aqueous polymer intermediate layer exhibits high oil resistance. Further, since the release paper is unnecessary, not only is there a cost advantage when used as a label, but it is not necessary to discharge the release paper unnecessarily. Since the silicone resin layer also functions as an overcoat layer, the layered thickness becomes thin,
Color can be developed at a good recording density during pressure-sensitive recording, the gloss and scratch resistance of the printed surface are excellent, and the pressure-sensitive information is disclosed and exposed to the outside due to the adhesive layer and opaque coating sheet on the release layer. The pressure-sensitive recorded information can be read by peeling off the opaque cover sheet if necessary. Further, since the adhesiveness and the adhesiveness between the aqueous polymer intermediate layer containing an acryloyl group or acrylamide group provided on the support and the silicone resin layer are excellent, uniform peelability and adhesiveness are maintained for a long period of time, and opaque. It is possible to prevent peeling of the silicone resin layer when the covering sheet is peeled off and reduction of the adhesive force due to migration of silicone to the adhesive layer. As described above, the present invention is of great practical significance because it can be used for many purposes such as continuous slips, pasting slips, labels, postcards and other correspondence, recording, dust-free recording paper, and the like.

Claims (4)

[Claims] 1. A pressure-sensitive recording layer in which microcapsules containing at least one of a color former and a developer are individually laminated on one surface of a support, or mixed to form a coating, and a water-based recording layer. In a pressure-sensitive recording sheet in which a molecular intermediate layer, a silicone resin layer, an adhesive layer, and an opaque coating sheet are sequentially provided,
The aqueous polymer intermediate layer contains a compound having an acryloyl group or an acrylamide group, and the silicone resin layer is a silicone compound in which an acryloyl group is introduced at the terminal or side chain of the molecular main chain of polydialkylsiloxane. And pressure sensitive recording sheet. 2. The pressure-sensitive recording sheet according to claim 1, wherein the compound having an acryloyl group or an acrylamide group contained in the aqueous polymer intermediate layer is a water-soluble or water-dispersible emulsion. 3. A step of providing a pressure-sensitive recording layer on one surface of a support, wherein microcapsules containing at least one of a color former and a color developer are individually laminated, or mixed and applied. A step of forming an intermediate layer by applying an aqueous polymer solution containing a compound having an acryloyl group or an acrylamide group on the layer, a step of applying a silicone resin on the intermediate layer to form a silicone resin layer, on the silicone resin layer or A pressure-sensitive recording sheet characterized by producing a pressure-sensitive recording sheet by applying an adhesive to one surface of an opaque coating sheet to form an adhesive layer, and integrating the opaque coating sheet and the silicone resin layer via the adhesive layer. Recording sheet manufacturing method. 4. The step of providing a silicone resin layer, wherein the compound having an acryloyl group and the silicone resin are cured with at least one of high energy rays composed of ultraviolet rays or electron rays. Method of manufacturing pressure sensitive recording sheet.