JPH04234473A - Pressure-sensitive adhesive sheet - Google Patents

Abstract

PURPOSE:To provide a pressure-sensitive adhesive sheet which is excellent in ink receptivity, capable of producing recorded images having clear outlines in recording on an ink jet printer, excellent in the storage stability of recorded images, and improved in the adaptability to writing and labeling. CONSTITUTION:A pressure-sensitive adhesive sheet formed by laminating at least a release agent layer, a pressure-sensitive adhesive layer and an ink jet recording paper on a release substrate and having a tensile strength of 5kg/cm<2> or more according to JISK-6301 of pressure-sensitive adhesives.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a pressure-sensitive adhesive sheet, and particularly relates to a pressure-sensitive adhesive sheet that has excellent recording suitability with water-based ink, that is, ink receptivity during recording, recorded image quality, and storage stability of recorded images, as well as improved writing characteristics and label suitability. The present invention relates to an adhesive sheet for inkjet recording.

0002

BACKGROUND OF THE INVENTION Adhesive sheets are used in a wide variety of applications, including commercial, office, and household uses, in the form of labels, stickers, stickers, patches, etc. That is, an adhesive sheet has an adhesive layer formed between a surface base material and a release base material, and paper, film, metal foil, etc. are used as the surface base material, and a release base material such as glassine paper is used as the release base material. High-density base paper, clay coated paper, polyethylene laminate base paper, etc. coated with a release agent such as a silicone compound or a fluorine compound are used. Further, as the adhesive forming the adhesive layer, various types of emulsion, solvent or solvent-free adhesives such as rubber-based, acrylic-based, and vinyl ether-based adhesives are used. Among these adhesive sheets, with the rise of computers in the information society, inkjet printers are being used in a wide variety of fields because they are low in noise, capable of high-speed recording, and can easily print in multiple colors. has been done.

Conventionally, efforts have been made to improve recording devices and ink compositions so that so-called plain paper, such as high-quality paper and coated paper, can be used as the surface base material of adhesive sheets for such uses. However, the reality is that a satisfactory product has not yet been obtained. Further, with the expansion of applications such as improved performance of recording devices such as higher speed recording and higher definition recording, and full color recording, more advanced characteristics are required for surface base materials. Specifically, for example, ink should be absorbed quickly without bleeding or staining, the horizontal diffusion of ink dots should be uniform and not unnecessarily large, and furthermore, the ink dots should be It is required that the density is high and clear, or that the recorded image does not discolor or fade due to the influence of light, oxygen in the air, etc. during storage.

[0004] In response to the above requirements, several proposals have been made in the past. For example, attempts have been made since the beginning of the development of inkjet recording paper to provide a coating layer (ink-receiving layer) mainly composed of a pigment with good ink absorption and a binder on a substrate. Silica-based pigments have generally been used (Japanese Patent Application Laid-open Nos. 52-9074, 55-51583, 56-148583,
No. 58-72495). In addition, a water-soluble polymer coating layer is used as the ink receiving layer (Japanese Patent Application Laid-Open No. 55-144172
No. 55-146786), and a proposal using a basic latex polymer (Japanese Patent Application Laid-open No. 57-36692) has also been made.

Furthermore, in order to improve poor water resistance, which is an inherent drawback of recording using water-based inks, a water-resistant agent is applied to the water-soluble polymer coating layer after inkjet recording. (Japanese Unexamined Patent Publication No. 55-150396, No. 56-58869), and a proposal to use specific pigments and resins that adsorb coloring components in water-based inks (Unexamined Japanese Patent Application No. 55-1989).
No. 5-144172) etc. have also been published.

[0006] Furthermore, water-based inks used for inkjet recording have become common, using water-soluble dyes such as acid dyes or direct dyes as coloring components; The porous silica that has been
Since it does not have the ability to adsorb these water-soluble dyes, the water resistance of recorded images is poor, and various attempts have been made to improve this. For example, use of porous basic pigments with excellent adsorption ability for water-soluble dyes having anionic groups as described above (JP-A-55-144172, JP-A-60-24558)
No. 8, No. 61-116579, No. 61-135785
) have also been attempted. In this case, although it has excellent storage suitability such as ink receptivity and water resistance, and the desired effects can be obtained, it is difficult in practical terms because the sharpness of the recorded image is significantly reduced.

[0007] On the other hand, even in these proposals, sufficient measures have not been taken to improve the performance of the device or to expand the range of applications, and further improvements have been made regarding ink receptivity, recorded image quality, and storage stability of recorded images. Further improvements are required. Furthermore, there have been problems with the adhesive label falling off from the release substrate due to the peeling force and the adhesive extruding from the edge of the sheet due to the adhesive.

[0008]

[Problems to be Solved by the Invention] The present invention provides excellent ink receptivity when recording with an inkjet printer, provides a clear recorded image with clear outlines, and also improves the storage stability and writability of the recorded image after recording. The present invention provides a pressure-sensitive adhesive sheet which is excellent in the properties of the present invention and has improved prevention of labels falling off and pressure-sensitive adhesive extrusion.

[0009]

[Means for Solving the Problems] The present invention provides an adhesive sheet formed by laminating at least layers of a release agent, an adhesive, and an inkjet recording paper on a release base, and the tensile strength of the adhesive based on JIS K-6301. Strength is 5Kg
/cm2 or more.

0010

[Operation] The present invention improves the quality of the recording paper by solving the conventional drawbacks of inkjet recording paper as described above, and further suppresses the falling off of the label or the extrusion of the adhesive during guillotine cutting, thereby improving the paper's performance. This invention relates to an adhesive sheet that uses inkjet recording paper as the top sheet and has improved paper suitability.

That is, in order to improve ink jet recording paper (top sheet), the present inventors provided a coating layer using a combination of porous basic pigment and porous silica on the surface of the base material of the recording paper. This improves the ink receptivity, the clarity of the recorded image, and the fluidity of the coating liquid for the coating layer, making it possible to form a uniform and stable coating layer, and as a result, improve the image contour. On the other hand, it is possible to obtain a clear recorded image of
For the first time, we have discovered that by specifying the tensile strength of adhesives and release agents, we can effectively solve problems such as their suitability for processing as adhesive sheets and problems such as adhesive extrusion and labels falling off during so-called cutting processing.

In the present invention, as the porous basic pigment used as one of the components of the ink-receiving layer, it is preferable to use a dry-granulated processed pigment as described below. That is, as a dry granulation method, for example,

[0013]
(1) A method using a hydrogel-forming substance such as aluminum hydroxide, alumina, silica, magnesium oxide, etc. as a raw material, drying such hydrogel to form a xerogel, and then crushing and classifying it for use;

(2) The raw materials used in (1) are granulated in a hydrogel state to an appropriate size of secondary or tertiary aggregates, and after drying, As disclosed in et.

(3) By producing urea-formalin resin, etc. in a suspension of fine particles such as colloidal silica and colloidal alumina, and adjusting the production conditions as disclosed in USP-3855172, etc., desired results can be obtained. A method in which microparticles are granulated to a secondary particle size and then dried and used, or if necessary, further fired and used as sintered particles;

(4) A basic pigment that has developed a porous crystal structure by reacting under predetermined conditions in the presence of various metal compounds containing aluminum, magnesium, zinc, calcium, silicon, etc. that constitute the pigment. A method of synthesizing, pulverizing and classifying if necessary
No. 79, No. 61-135785), etc.

These porous basic pigments produced using various known methods can be used as appropriate, and many porous basic pigments are commercially available. Therefore, in the present invention, among these porous basic pigments, those having excellent adsorption ability for water-soluble dyes having an anionic group such as so-called acid dyes or direct dyes are selectively used. It is. Whether or not a porous basic pigment has excellent adsorption ability for water-soluble dyes can be determined by the color density when a predetermined amount of porous pigment is added to a predetermined aqueous ink diluted with water. It can be carried out.

[0018] If the porous basic pigment does not have adsorption ability or has a weak adsorption ability for water-soluble dyes such as acid dyes or direct dyes in the water-based ink, the following method may be used. It is possible to impart adsorption ability.

That is, the surface of the porous basic pigment is made cationic by using a polyvalent metal compound such as an aluminum alcoholate, an aluminum chelating agent, a water-soluble aluminum salt, or an aluminum soap, or a cationic silane cup is used. A method of imparting a cationic group to the surface of a porous basic pigment using a ring agent, a titanate coupling agent having a cationic group in the molecule, or a cationic surface treatment agent such as a reactive cationic resin. Accordingly, it is also possible to use the porous basic pigment by imparting dye adsorption ability to it. Specific methods for treating porous basic pigments using such treatment agents include, for example, spraying a treatment agent solution directly onto the porous pigment using a sprayer, and spraying the porous pigment in any solvent. Known methods can be used, such as dispersing the mixture in a liquid and bringing it into contact with a treatment agent. If necessary, solvent removal treatment,
It is used as a porous basic pigment after being subjected to drying treatment, heat treatment, etc.

In order for the porous basic pigment to exhibit sufficient ink receptivity, it is preferable that the pigment be porous and in the form of fine particles. Specifically, the specific surface area measured by the BET method (nitrogen method) is preferably 50 m2.
/g or more, and in the coating liquid for the ink receiving layer,
Dispersed particles having an average particle diameter of 0.5 to 15 μm (measured value at Coulter counter/AP=50 μm) are preferably used. In particular, the specific surface area is 1
00 to 500 m2/g, and the average particle size is 2 to 500 m2/g.
A 10 μm porous basic pigment is desirable because it effectively contributes to the efficient transfer of the aqueous ink medium to the substrate and the retention of the colored components. Incidentally, if the specific surface area is small, ink receptivity may be insufficient and bleeding or staining may occur.
Furthermore, if the average particle diameter is small, the sharpness of the recorded image may be lost, resulting in a dull recorded image. On the other hand, if the average particle diameter exceeds 15 μm, the ink dots may spread unevenly in the lateral direction, and the sharpness of the recorded image may be lost.

[0021] As the porous silica used in combination with the porous basic pigment, porous ones are selected from among the known silica pigments that do not have the above-mentioned dye adsorption ability in contrast to the porous basic pigment. Used selectively. In addition, in order to exhibit excellent ink receptivity and provide a recorded image with excellent clarity when used in combination with a porous basic pigment, the specific surface area in the BET method (nitrogen method) is preferably 200 m2 /
Porous silica having an average particle size of 0.5 to 15 μm (measured value at Coulter Counter/AP=50 μm) in the form of dispersed particles in the coating liquid for the ink receiving layer is preferred. In particular, the specific surface area is 250
~500 m2/g, and the average particle size is 2~10μ
Porous silica (m) is preferable because it improves ink receptivity and provides recorded images with excellent clarity when used in combination with a porous basic pigment. Incidentally, if the specific surface area is small, ink receptivity decreases and bleeding or staining occurs, which poses a practical problem. On the other hand, if the average particle diameter is too small, the sharpness of the recorded image may be lost, resulting in a dull recorded image. Note that if the average particle diameter exceeds 15 μm, there is a risk that the ink dots will spread unevenly in the lateral direction and the sharpness of the recorded image will deteriorate.

[0022] Furthermore, by increasing the pore radius (nitrogen method) of porous silica when measured by the BET method compared to the porous basic pigment used in combination, it is possible to improve the clarity of the image and improve the ink quality. It can also significantly improve acceptability, and its effects are remarkable. In this case, the porous silica contributes to water-based ink absorbability immediately after recording, and dye adsorption to the surface of the porous basic pigment occurs thereafter, resulting in excellent storage stability of the recorded image.

When the amount of porous silica used is 5 to 300 parts by weight based on 100 parts by weight of the porous basic pigment, its effect becomes more remarkable, and particularly excellent ink receptivity and clear color can be obtained. An inkjet recording paper to which a recorded image can be applied is obtained. If the amount of porous silica exceeds 300 parts by weight, the storage stability of the recorded image will be reduced, while if it is less than 5 parts by weight, the effect of improving sharpness will be insufficient.

The porous basic pigment and porous silica selected in this way are prepared as a coating liquid by dispersing and mixing them in various media, but they can be prepared by dispersing and mixing them in a hydrophilic medium, which is generally done. In this case, it is preferable to use a nitrogen-containing water-soluble resin as the protective colloid agent, since this improves fluidity and provides a coating liquid with excellent coating stability.

Examples of these nitrogen-containing water-soluble resins include proteins such as gelatin, albumin, casein and soybean protein, polysaccharides such as chitosan and cationically modified starch, natural and semi-synthetic polymer compounds such as polyvinylpyrrolidone, and polyvinylpyrrolidone. , polyacrylamide, addition-polymerizable synthetic polymer compounds such as water-soluble polymers or copolymers containing cationic groups, polyethyleneimine resins, polyamine resins, polyamide resins, polyamide epichlorohydrin resins, polyamine epichlorohydrin resins, etc. Various condensation type synthetic polymer compounds such as resins, polyamide polyamine epichlorohydrin resins, dicyandiamide resins, ionene type resins, etc. are known, and can be appropriately selected and used.

It should be noted that, as long as the effects of the present invention are not impaired, further suitability such as imparting writability, imparting suitability to equipment, controlling ink absorption, controlling appearance of recording paper, controlling suitability for paint, controlling physical properties of paint, or controlling drying properties may be added. For application, pigments, binders, various auxiliary agents, etc. are added as appropriate to form a coating liquid for the ink-receiving layer, which is then applied and dried onto various substrates to obtain inkjet recording paper.

Examples of the above pigments include calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium oxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, and Inorganic pigments such as regular silica, aluminum hydroxide, alumina, lithopone, organic or organic/inorganic composite pigments such as styrene plastic pigments, acrylic plastic pigments, microcapsule pigments, urea resin pigments, melamine resin pigments, etc. , pigments known in the general pigment coating field for coated paper are used as appropriate.

Examples of binders include oxidized starch, etherified starch, carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, natural or semi-synthetic polymers such as soybean protein, polyvinyl alcohol and its derivatives, polyethyleneimine resins, Polyvinylpyrrolidone resin, poly(meth)acrylic acid or its copolymer, maleic anhydride copolymer, acrylamide resin, (meth)acrylic acid ester resin, polyamide resin, polyurethane resin, (unsaturated) polyester Synthetic water-soluble or solvent-soluble resins such as polyvinyl butyral resin, alkyd resin, epoxy resin, epichlorohydrin resin, urea resin, melamine resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, etc. Conjugated diene polymer latexes, acrylic polymer latexes such as polymers or copolymers of acrylic acid esters and methacrylic acid esters, vinyl polymer latexes such as ethylene-vinyl acetate copolymers, or these. Examples of resins known in the technical field include functional group-containing modified polymer latexes, which are obtained by adding anionic groups and/or cationic groups to various polymers, and can be used alone or in combination as appropriate. . The amount of these binders to be used can be arbitrarily determined by taking into consideration the recording suitability of the desired recording medium, suitability for use, suitability for coating of the coating liquid (for ink receiving layer), etc., but in general, , 1 to 200% by weight, preferably 5 to 50% by weight.

Furthermore, pigment dispersants, thickeners,
Flowability improvers, antifoaming agents, foam inhibitors, foaming agents, mold release agents, penetrating agents, wetting agents, thermal gelling agents, lubricants, dyes, pigments, fluorescent dyes, and ultraviolet rays for color adjustment such as blue tinting. Various auxiliary agents known in the technical field, such as absorbents, antioxidants, quenchers, preservatives, antifungal agents, antistatic agents, water-resistant agents for binders, and crosslinking agents, are added to form the ink-receiving layer. It is prepared as a coating liquid for use. If the coating liquid containing the various components mentioned above does not become a uniform dispersion due to coagulation, etc., create two or more separate coating liquids and apply the coating two or more times to obtain the desired ink. A receiving layer can also be obtained.

These ink-receiving layer coating liquids can be applied to a bar coater, air knife coater, blade coater, rod blade coater, roll coater, brush coater, curtain coater, gravure coater, etc. using a conventional method.
Coating is done using various known coating methods such as cast coaters and spray equipment, but the coating amount does not need to be unnecessarily large as long as it satisfies recording suitability such as ink receptivity and preservability. , 1 to 30 g/m2, preferably 2 to 8 g/m2. The inkjet recording paper thus obtained can be used as is, but if necessary, it may be passed through a pressurized and/or heated roll nip of a super calender, gloss calender, etc. to smooth the surface by a conventional method. You can also.

In the present invention, materials having flatness such as paper, cloth, cellophane, plastic film, metal plate, wood plate, glass plate, etc. are used as the base material of the ink jet recording paper. In particular, paper has excellent water absorption properties because the base material itself has a porous structure, and when an ink receiving layer according to the present invention is formed, it is possible to provide inkjet recording paper with excellent recording suitability with a smaller coating amount. It is most preferably used because it is excellent in , and economic efficiency. In addition,
In order to improve the applicability of the coating liquid for the ink-receiving layer onto the substrate, common surface treatments such as corona discharge treatment, plasma treatment, chemical cleaning treatment, etc., and resin treatments such as gelatin, nitrocellulose, and polyester are used. It is also possible to use known anchor coat layers, such as layers and/or layers treated with auxiliary agents such as colloidal silica, metal coupling agents, and isocyanates. In addition, if necessary, surface treatments such as antistatic treatment and writing suitability (printability) imparting treatment may be performed on the front and/or back surfaces of the base material, or ultraviolet absorbers, It is also possible to further improve the storage stability of recorded images by incorporating auxiliary agents such as antioxidants.

Among the above-mentioned base materials, paper is generally made mainly of wood pulp, but various fibrous substances such as synthetic fibers, synthetic pulp, and inorganic fibers are also used as necessary, and rosin is used as an additive. , alkyl ketene dimers, sizing agents such as alkenyl succinic acid, fixing agents such as sulfate band, cationic polymer electrolytes, clay, talc,
Calcium carbonate, calcined kaolin, aluminum oxide, aluminum hydroxide, titanium oxide, amorphous silica, urea
Fillers represented by formalin resin particles, paper strength enhancers represented by polyacrylamide polymers, starch, etc.
Wet paper strength agents represented by melamine resin, urea resin, polyamide-polyamine-epichlorohydrin resin, etc.
In addition, various auxiliary agents such as filtering agents, dyes for color tone adjustment such as bluing, pigments, fluorescent dyes, etc. are appropriately selected and internally added, and the paper is made using various paper machines according to conventional methods, and if necessary, After surface size press coating with an aqueous liquid consisting of starch, polyvinyl alcohol, gelatin, filler, etc., it is manufactured through conventional treatment steps such as smoothing treatment using a machine calender or the like.

[0033] These papers also vary in pulp composition, beating conditions, fillers, paper strength enhancers, internal sizing agents, pH adjusters, surface sizing agents, surface treatment agents, etc., and the types and amounts of various auxiliary agents added. The suitability of the base material as an inkjet recording paper is controlled and used by appropriately selecting and adjusting operating conditions such as drying conditions and pressurizing conditions to suit each paper machine.

Clay coated paper, glassine paper size-pressed with polyvinyl alcohol, starch, etc. are used as the release base, but when the release base is based on base paper, an undercoat layer is used to prevent penetration of the release agent. The main component of such an undercoat layer is, for example, a polyolefin resin such as polyethylene or polypropylene, or an emulsifier having a molecular weight of 1,000 to 10,000 and containing 2 to 10% by weight and a glass transition temperature of -60 to 0°C. Polymers such as water-dispersible acrylic ester copolymer resins are used. If necessary, the primer layer contains a cellulose derivative,
Various water-soluble natural polymers such as starch derivatives, synthetic polymers such as polyvinyl alcohol, antifoaming agents, penetrating agents, wetting agents, anti-blocking lubricants, leveling agents, curing agents, thickening agents, film formation. Auxiliary agents, antistatic agents, water-soluble plasticizers, etc. can also be included.

[0035] Furthermore, the adhesive force between the surface substrate and the release substrate is closely related to the suitability for paper passing in an inkjet recording type printer, and in order to obtain good release performance, it is necessary to Tensile strength is 30
It is preferable that it is Kg/cm2 or more. By the way, 3
If it is less than 0 kg/cm2, the adhesive label is likely to fall off inside the printer, causing poor paper running.

[0036] A method for forming an adhesive sheet is, for example, by coating a release sheet with a solvent-based adhesive, an emulsion-type adhesive, a hot-melt adhesive, etc., and drying as necessary to form an adhesive layer. is formed, a surface base material is laminated, and the humidity is controlled and finished. In the present invention, the tensile strength of the adhesive forming the adhesive layer is JIS K63.
It is necessary that the measured value based on 01 is 5Kg/cm2 or more. By the way, the tensile strength of the adhesive is 5kg.
/cm2, when the adhesive sheet is die-cut or sheet-cut on a printing machine, the adhesive adheres significantly to the cutting blade and cutting surface, causing poor paper running.

[0037]

[Examples] The present invention will be explained in more detail with reference to Examples below, but it is of course not limited to these Examples. In addition, unless otherwise specified, the coating amount, number of parts, and mixing ratio in the examples are all expressed in weight solid content.

Example 1 Aluminum sulfate aqueous solution (8.0 as Al2O3
%) was diluted in 7 liters of water and heated to 95° C. with stirring in a 20 liter container. A 1 liter solution prepared by dissolving 320 g of sodium hydroxide in water was added to this solution, and the mixture was aged for 1 hour with stirring to produce a seed alumina hydrogel slurry. Next, this slurry was added to an aluminum sulfate aqueous solution (A
Add 400 g of 8.0% as l2O3 and adjust the pH.
After holding for 5 minutes at 4.5, sodium hydroxide 2
393 milliliters of a 90 g/liter aqueous solution was added to adjust the pH to 11 and hold for 10 minutes. After repeating the same pH change operation five times, the mixture was filtered, washed, and dried. Next, after dry pulverizing and baking at 450 °C for 8 hours,
A porous basic pigment was obtained by classification (specific surface area: 300 m2/g, pore radius: 37.5 Å, average particle diameter: 4.8 μm).

75 parts of the porous basic pigment thus obtained were mixed with commercially available porous silica (Syroid 244, manufactured by Fuji Davison Co., Ltd., specific surface area 300 m2/g, pore radius 105 Å, average particle diameter 1.8 μm) 25 Part and nitrogen-containing water-soluble resin (Sumirezu Resin 1001:
Polyvinyl alcohol (PVA-110: Kuraray Co., Ltd.) was dispersed and mixed in 500 parts of a 1% aqueous solution of Sumitomo Chemical Co., Ltd. (manufactured by Sumitomo Chemical Co., Ltd.) using a Coles disperser, and then polyvinyl alcohol (PVA-110: Kuraray Co., Ltd.) was added as a binder.
A coating solution for forming an ink-receiving layer was prepared by adding 350 parts of a 10% aqueous solution of 100% (manufactured by JP, Ltd.) and further adding a fluorescent dye and an antifoaming agent. This coating liquid was applied on a base material made of acidic paper with a basis weight of 84 g/m2 and a Steckigt sizing degree of 2 seconds to a thickness of 4.5 g/m2, and then dried, followed by super calender treatment. An inkjet recording paper was obtained.

On the other hand, a butyl acrylate-acrylonitrile-acrylic acid ternary copolymer containing 2% of an emulsifier with a molecular weight of 2500 [trade name: RIKABOND ET-L-924]
-1 (glass transition temperature = -14℃) / Chuo Rika Kogyo (
Co., Ltd.] 100 parts and 2% emulsifier with a molecular weight of 2500.
Quaternary copolymer of butyl acrylate, acrylonitrile, methyl methacrylate, and acrylic acid containing [trade name: RIKABOND ET-L-924-2 (glass transition temperature = 4
8℃)/manufactured by Chuo Rika Kogyo Co., Ltd.] to an aqueous copolymer mixed with 20 parts, 10 parts of polyvinyl alcohol, 1 part of glycerin, 2 parts of colloidal silica, and 0.1 part of an antifoaming agent were added. A 40% aqueous treatment solution for the undercoat layer was prepared.

[0041] This aqueous treatment liquid for undercoat layer has a basis weight of 49 g/
m2 and 65 μm thick high-quality paper was coated and dried using a rod blade coater so that the dry coating amount was 4 g/m2 to obtain a release substrate having an undercoat layer.

Next, a silicone release agent (trade name: BY24-162, tensile strength 40 kg/
cm2 / Toray Dow Corning Silicone Co., Ltd.
9% toluene solution (manufactured by Co., Ltd.) with a dry coating amount of 1 g/m2
A release sheet was obtained by coating with a bar coater and drying to obtain the following.

[0043] Apply an acrylic emulsion adhesive (trade name: Olivine B) to the release agent layer surface of the release sheet obtained above.
PW-5082-2: Tensile strength 8.0Kg/cm2
/ manufactured by Toyo Ink Manufacturing Co., Ltd.) was coated and dried using a reverse roll coater so that the dry coating amount was 15 g/m2. Next, the inkjet recording paper was layered on this adhesive layer and bonded together using a press roll to obtain an adhesive sheet.

[0044] Cut this adhesive sheet into A4 size and use an inkjet recording type word processor printer (product name;
Printed with Canoward α-50/manufactured by Canon Co., Ltd.
The results obtained are shown in Table 1.

Example 2 A porous basic pigment was obtained in exactly the same manner as in Example 1 except that the pH varying operation was performed 10 times instead of 5 times (specific surface area 350 m2/g: pore radius 76 Å). , average particle size 5.2 μm).

60 parts of the obtained porous basic pigment was mixed with commercially available porous silica (Syroid 404, manufactured by Fuji Davison Co., Ltd., specific surface area 300 m2 /g: pore radius 85
Å, average particle size 5.2 μm) and 400 parts of a 2% aqueous solution of nitrogen-containing water-soluble resin (Epinox P-800, manufactured by DIC Hercules Corporation) using a Coles disperser. , polyvinyl alcohol (PVA-117/PVA-205) as a binder.
A mixture of equal amounts of: 10% aqueous solution of Kuraray Co., Ltd. 4
00 copies were added, and the following procedure was carried out in the same manner as in Example 1 to obtain inkjet recording paper (coating amount: 8 g/m2).

[0047] A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 using the above surface base material, and printed using an inkjet type word processor printer. The results obtained are shown in Table 1.

Example 3 67 parts of a commercially available porous basic pigment (fine powder alumina A-5, manufactured by Mizusawa Chemical Industry Co., Ltd./specific surface area 306 m2/g, pore radius 60 Å, average particle diameter 4.4 μm) was added. Porous silica (Mizukasil P78D: manufactured by Mizusawa Chemical Industry Co., Ltd./
33 parts (specific surface area: 350 m2/g, pore radius: 90 Å, average particle size: 7.6 μm) were dispersed and mixed in 500 parts of a 1% aqueous solution of a nitrogen-containing water-soluble resin (Chemistat 7300, manufactured by Sanyo Chemical Co., Ltd.). Then, after adding the fluorescent dye and the antifoaming agent, it was washed three times using a vertical sand mill filled with spherical glass beads (bead diameter 2 mm; filling rate 60%) at a flow rate with an average residence time of 0.5 minutes. The liquid was passed through the tube.

Next, silyl-modified polyvinyl alcohol (R-1130
: 200 parts of a 10% aqueous solution (manufactured by Kuraray Co., Ltd.) was added to prepare a coating liquid for forming an ink receiving layer. Basis weight 68g/m2
After coating and drying the mixture to a dry weight of 3.5 g/m2 on a base material made of neutral paper with a Steckigt size of 9 seconds, supercalender treatment was performed to obtain inkjet recording paper.

A 9% toluene solution of a silicone release agent (trade name: KS-845, tensile strength 30 Kg/cm2, manufactured by Shin-Etsu Chemical Co., Ltd.) was dried and applied on the undercoat layer of the same release base as in Example 1. A release sheet was obtained by coating with a bar coater and drying so that the coating amount was 1 g/m2.

[0051] Acrylic emulsion adhesive (trade name: NICAZOL TS-1369: tensile strength 5.5 Kg/cm2) was applied to the release agent side of the release sheet thus obtained.
/manufactured by Nippon Carbide Co., Ltd.) with a dry weight of 17 g/m
The adhesive layer was coated with a knife coater and dried to obtain a pressure-sensitive adhesive layer of 2. Next, the inkjet recording paper was layered on this adhesive layer and bonded together with a press roll to obtain an adhesive sheet. The adhesive sheet thus obtained was printed using an inkjet word processor printer, and the results are shown in Table 1.

Example 4 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that 30 parts of porous basic pigment and 70 parts of porous silica were used. The obtained adhesive sheet was printed using an inkjet type word processor printer, and the results are shown in Table 1.

Comparative Example 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that 100 parts of porous basic pigment was used instead of porous silica. The adhesive sheet thus obtained was printed using an inkjet word processor printer, and the results are shown in Table 1.

Comparative Example 2 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the porous basic pigment was not used and the amount of porous silica was 100 parts. The adhesive sheet thus obtained was printed using an inkjet word processor printer, and the results are shown in Table 1.

Comparative Example 3 SRX-211 (trade name/tensile strength 1
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that 5 kg/cm2/manufactured by Toray Dow Corning Silicone Co., Ltd. was used. However, the peeling force of the adhesive label was too small, causing the label to fall off inside the word processor printer.

Comparative Example 4 In Example 1, the adhesive was an acrylic emulsion adhesive (trade name: NICAZOL L-122: tensile strength
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the pressure was 2.5 Kg/cm2/manufactured by Nippon Carbide Co., Ltd.). However, when die-cutting and sheet-cutting this adhesive sheet, the adhesive adhered to the cutting blade and cut surface, causing roll stains in the non-impact printer.

(Evaluation method of adhesive sheet) The inkjet recording suitability was evaluated using a word processor printer (made by Canon Co., Ltd.).
Various test patterns were printed using Canoward α-50) for evaluation.

Ink receptivity: The dry state of the printed (solid) area was visually observed, and 2 seconds after printing, the paper was brought into contact with a paper pressure roll to check for stains. Recorded image quality: Sharpness was determined visually. Light resistance: The recorded matter was pasted on the wall of an office, and the change in color tone was visually judged after leaving it under room light for one year. Water resistance of recorded image: Changes in the recorded image after the recorded matter was immersed in running water for 5 minutes were visually determined. Writing aptitude: When handwriting with a pencil (HB),
The presence or absence (degree) of shedding of the coated surface of the ink-receiving layer was compared. Paper feeding suitability: We looked at the degree of jamming when running on a word processor printer. Adhesive suitability: After printing, it was pasted on an envelope and the adhesive strength was evaluated.

(Evaluation criteria) A...Excellent B...Good C...Poor D...Significantly inferior

Table 1 shows the evaluation results of the four inkjet recording pressure-sensitive adhesive sheets of Examples to Comparative Examples.

[0061]

[Table 1]

[0062]

Effects of the Invention The adhesive sheet of the present invention has excellent ink receptivity during recording, recorded image quality, storage stability of recorded images after recording, writing suitability, etc., and has excellent properties such as ease of label falling off (adhesive strength) and adhesiveness during guillotine cutting. It was an adhesive sheet for inkjet recording that suppressed extrusion of the agent and had excellent paper passing properties.

Claims (4)

[Claims] Claims: 1. A pressure-sensitive adhesive sheet comprising a release substrate laminated with at least layers comprising a release agent, an adhesive, and an inkjet recording paper, wherein the pressure-sensitive adhesive has a tensile strength of 5 kg/cm2 or more based on JIS K-6301. An adhesive sheet characterized by: 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the release agent has a tensile strength of 30 kg/cm2 or more based on JIS K-6301. 3. The pressure-sensitive adhesive sheet according to claim 1, wherein the inkjet recording paper has a coating layer containing a combination of porous basic pigment and porous silica on the surface of the base material. [Claim 4] The specific surface area of porous silica is 200 m2.
4. The pressure-sensitive adhesive sheet according to claim 3, wherein the pore radius is greater than /g and the pore radius is larger than the pore radius of the porous basic pigment.