JP2002138256A - Pressure-sensitive adhesive sheet and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a pressure-sensitive adhesive sheet which does not cause curling with changes in the environment and is suited in use for plain paper and flat sheet printings by various types of printers. SOLUTION: The pressure-sensitive adhesive is obtained by laminating a release sheet on a pressure-sensitive adhesive layer provided on at least one sheet-like surface of a base, and the base with the sheet-like surfaces having the pressure-sensitive adhesive layer and the release sheet differ in the degree of shrinkage by temperature and relative humidity, and the both has a Gurley stiffness prescribed by JAPAN TAPPI No.40 in the range of 0.2-15 mN, respectively and, at the same time, when the pressure-sensitive adhesive sheet is left to stand at a relative humidity of 50% at 23 deg.C for 24 hours, and then left to stand for 72 hours by changing the relative humidity to 20%, the quantity of slip (|N|) in the CD direction of the release sheet and the base with the sheet-like surfaces having the pressure-sensitive adhesive layer and the length in the CD direction of the release sheet meet the formula: |N|/L×100 >=0.05%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive sheet using a film or paper as a surface substrate, and more particularly to a pressure-sensitive adhesive sheet which is free from curling and is suitable for paper passing and lithographic printing, and ink jet recording. The present invention relates to a pressure-sensitive adhesive sheet suitable for paper. The present invention also relates to a method for producing the pressure-sensitive adhesive sheet.

2. Description of the Related Art Conventionally, adhesive sheets have been used for labels, seals,
It is used for a wide range of applications such as commercial use, office use, and home use, such as stickers, patches, and overlamps. This pressure-sensitive adhesive sheet is generally formed by laminating a surface substrate, a pressure-sensitive adhesive, and a release sheet. As the pressure-sensitive adhesive, a solvent-based pressure-sensitive adhesive such as a rubber-based, acrylic, or vinyl ether-based pressure-sensitive adhesive, an emulsion-type pressure-sensitive adhesive, a hot-melt-type pressure-sensitive adhesive, or the like is used. High quality paper, kraft paper,
General papers such as art paper, coated paper, cast coated paper, etc., thermal recording media, thermal transfer image receiving sheets, recording sheets such as ink jet recording sheets, aluminum foil laminating paper, aluminum evaporated paper, resin impregnated paper, synthetic paper, etc. Special papers, films of PET, polypropylene, polyvinyl chloride and the like are used.

As a release sheet, polyethylene laminate paper, glassine paper, clay-coated paper, water-based resin-coated paper, or a polyester or olefin-based film is used as a release base paper, and a silicone compound or fluorine is provided on the side in contact with the adhesive. A release agent such as a compound is applied and used. Normally, when manufacturing an adhesive sheet, select the surface base material and the adhesive listed above according to the application, and use the combination of the surface base material, the adhesive and the release sheet to perform various printing methods and label sticking operations. Manufacture to be an excellent adhesive sheet. Therefore, in many cases, the pressure-sensitive adhesive sheet is formed by bonding two types of materials having different properties, such as a surface substrate and a release sheet. Such an adhesive sheet is apt to curl due to environmental changes. When the pressure-sensitive adhesive sheet is curled, for example, the suitability for paper passing with various printers and the workability such as a printing process and a label attaching operation are significantly reduced.

[0003] As a cause of such curling, two kinds of sheets made of different materials are laminated, so that the temperature,
Due to the bimetallic action caused by environmental changes such as humidity, or the change in tension in the lamination process between the surface substrate and the release substrate during processing of the adhesive sheet, the winding habit generated when winding after processing, or these phenomena Many are due to combined effects. Conventionally, in order to prevent such curling, a method of, for example, equalizing the characteristics of the materials to be bonded with respect to temperature, humidity, and the like has been adopted. Further, as a correction of curl due to a change in tension at the time of manufacturing, it has been proposed that the surface base material and the release base material are once peeled off and re-laminated as disclosed in Japanese Patent Publication No. 1-3268. Also, as disclosed in Japanese Patent No. 2999616, it has been proposed to select and use a material having a small difference in expansion and contraction ratio between a surface substrate and a release sheet due to environmental changes.
However, even with the above method, the curl due to the bimetal action caused by environmental changes such as temperature and humidity cannot be solved.

[0004] Even if the surface base material and the release base material are once peeled off and re-laminated, if the expansion and contraction ratios of the surface base material and the release base material in each environment are different, distortion between the surface base material and the release sheet of the pressure-sensitive adhesive sheet is caused. And curl occurs. Further, even if the pressure-sensitive adhesive sheet has a small dimensional difference between the surface substrate and the release sheet due to environmental changes, a slight dimensional difference causes curl. In addition, even if a surface substrate and a release sheet having a dimensional difference due to environmental changes of zero are selected and used, a stretching difference occurs due to the tension between the surface substrate and the release sheet in the operation during adhesive processing,
At present, curling cannot be completely controlled.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pressure-sensitive adhesive sheet which is suitable for paper-passing and flat-sheet printing by various printers which do not cause curl due to environmental changes. Another object of the present invention is to provide a method for efficiently producing the pressure-sensitive adhesive sheet.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, by causing a slip between the release surface of the release sheet and the surface of the pressure-sensitive adhesive layer, the present inventors have found that Even if a dimensional difference occurs between the surface substrate and the release substrate due to the change, a shift occurs between the surface substrate and the release sheet,
The present inventors have found that the dimensional difference can be reduced and curling due to environmental changes can be prevented, and the present invention has been completed.
That is, the present invention relates to a pressure-sensitive adhesive sheet obtained by laminating a release sheet on a pressure-sensitive adhesive layer provided on at least one surface of a sheet-like surface substrate, and the sheet-like surface substrate including the pressure-sensitive adhesive layer and the temperature of the release sheet. The expansion and contraction ratios due to humidity are different, and both JAPANTAPPI Nos. Gurley stiffness specified in 40 is in the range of 0.2 to 15 mN, respectively.
The adhesive sheet is treated at a relative humidity of 50% at a temperature of 23 ° C. for 24 hours.
After leaving for a period of time, the relative humidity was changed to 20%, and after leaving for 72 hours, the slip amount (| N |) of the release sheet and the surface substrate including the adhesive layer in the CD direction and the length of the release sheet in the CD direction A pressure-sensitive adhesive sheet characterized in that the pressure-sensitive adhesive sheet (L) satisfies the following formula (I). | N | /L×100≧0.05% (I) The present invention also provides a pressure-sensitive adhesive after providing a pressure-sensitive adhesive layer on a release sheet, and then laminating a sheet-like surface base material on the pressure-sensitive adhesive layer. Provided is a method for producing the pressure-sensitive adhesive sheet, wherein the pressure is applied to the pressure-sensitive adhesive sheet by bringing the surface of the sheet-shaped surface substrate on which the layer is not provided into contact with a roll.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As a sheet-like surface substrate used in the present invention, JAPAN TAPPI No. Gurley stiffness specified in 40 is 0.2 to 15 mN, preferably 1
１５15 mN is used. Here, JAPAN TA
PPI No. 40 is, for example, JAPAN TAPP
I Paper pulp test method. In particular,
As a support for the sheet-like surface base material, there are general papers such as high-quality paper, polyethylene laminated paper, kraft paper, art paper, coated paper, cast coated paper, etc., special papers such as resin-impregnated paper, synthetic paper, polyester (for example, Films and nonwoven fabrics such as PET), polyolefin (for example, polypropylene), and polyvinyl chloride, and a laminate thereof can be used. As the surface base material, these supports are used alone, or a thermosensitive recording medium having a recording layer formed on these supports, a thermal transfer image receiving sheet, a recording sheet such as an ink jet recording sheet, an aluminum vapor-deposited paper subjected to metal vapor deposition, Metallic vapor-deposited sheets such as aluminum vapor-deposited films, metal foil laminating paper (for example, aluminum foil laminating paper) can be used, and although not specified, an ink jet recording sheet having a recording layer that remarkably absorbs and escapes moisture due to a change in humidity. In such a case, the effect of the present invention is great. In the present invention, among these, the support of the surface substrate is JAPAN TAPPI No. Those having a high Gurley stiffness defined by 40 are preferred. It is more preferable to use a material having a low dimensional change speed due to a change in temperature and humidity. As such, it is preferable that the support of the surface substrate is a sheet in which resin layers are formed on both sides of pulp paper. For example, a double-sided polyethylene laminate in which polyethylene resin layers are formed on both sides of high-quality paper or the like can be used. Although the thickness of the surface substrate used in the present invention is arbitrary, it is preferably 50 to 190 μm, and more preferably 100 to 190 μm.

[0007] The support of the release sheet used in the present invention may be a commonly used base paper such as high-density base paper such as glassine paper, clay-coated paper, kraft paper or woodfree paper, for example, casein, dextrin, starch, Carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, (meth) acrylate A base material provided with a filler layer containing a natural or synthetic resin and a pigment as main components such as a copolymer, or a glass paper, a kraft paper or a high quality paper or the like, and a laminated plastic sheet of a synthetic resin such as polyethylene, or Polyole such as polypropylene Fin, polyester such as polyethylene terephthalate, polyamides, polyesteramides, polyimides, polyamide-imides, polyether,
Polyetherester, polycarbonate, polyphenylene sulfide, polystyrene, polyvinyl chloride, poly (meth) acrylate, and copolymers and mixtures of these, crosslinked films, and the like can be used.
As a release sheet, an emulsion type,
After applying a solvent-type or solvent-free type of release agent such as silicone resin or fluororesin so that the dry weight becomes about 0.05 to 3 g / m ² , the release agent layer is formed by heat curing, electron beam or ultraviolet curing. The formed one is appropriately used. Above all, JAPAN TAPPI of release sheet support
No. Gurley stiffness specified in 40 is 0.2-15m
N, preferably 1 to 15 mN. As such, it is preferable that the support constituting the release sheet is a sheet in which resin layers are formed on both sides of a paper support.

[0008] Specifically, a double-sided polyethylene laminate product in which polyethylene resin layers are formed on both sides of pulp paper can be mentioned. In addition, as an application device for applying the release agent,
Although not particularly limited, for example, a bar coater,
A direct gravure coater, offset gravure coater, air knife coater, multi-stage roll coater and the like are used as appropriate. In addition, a sample of 300 mm × 50 mm was prepared by using the adhesive sheet as the long side and the short side in the flow direction of the paper machine, and peeled at a peel angle of 180 ° in the flow direction under a test condition of a peeling speed of 0.3 m / min. Release sheet is preferably 0.90 to 7.8 N / m,
Further, it is preferably from 0.90 to 5.5 N / m, since slip between the pressure-sensitive adhesive layer and the release sheet is easily developed. The thickness of the release paper used in the present invention is arbitrary, but is 15 to 200 μm.
And more preferably 30 to 160 μm
It is. In the present invention, curling is prevented when the sheet-like surface base material including the pressure-sensitive adhesive layer and the release sheet have different expansion and contraction rates due to temperature and humidity.
%, The environment is changed to 23 ° C. and the relative humidity is 20% after standing for 24 hours, and the difference in the expansion and contraction ratio between the sheet-like surface base material including the pressure-sensitive adhesive layer and the release sheet after 24 hours is preferably 0.05 to 5.0%.
It is to prevent curling that occurs at 1.5%, more preferably 0.1 to 0.8%. In the present invention, it is preferable that one of the support constituting the surface substrate and the release sheet is a sheet in which resin layers are formed on both sides of a paper support, and the other is a film. Examples of such a combination include a substrate in which a recording layer is formed on one side and / or both sides of a support in which a pulp paper is laminated on both sides with a polyethylene resin, and a release sheet is a polyester film or an olefin-based material. What applied the release agent to the film is mentioned.

Further, the surface substrate is formed by forming a recording layer on one side and / or both sides of a polyester film or an olefin film, and the release sheet is formed on one side of a support obtained by laminating polyethylene resin on both sides of pulp paper. And / or a release agent applied to both surfaces. In addition, one of the surface base material or the release sheet has a large Gurley stiffness (for example, Gurley stiffness 1 to 15 mN) obtained by laminating a synthetic resin or the like on both sides of pulp paper.
The other substrate using a film or the like having almost no expansion and contraction ratio (for example, expansion and contraction ratio of 0 to 0.01) is preferable from the viewpoint of curling prevention. Specifically, Gurley stiffness obtained by laminating synthetic resin or the like to a thickness of 5 to 40 μm on both surfaces of a pulp paper having a basis weight of 50 to 150 g / m ² , respectively, has a Gurley stiffness of 1 to 15 mN, 0 to 0.01, a combination of a polyethylene terephthalate having a thickness of 15 to 200 μm or a polyolefin film, or a surface substrate having a stretch ratio of 0 to 0.01 and a polyethylene terephthalate or a polyolefin film having a thickness of 15 to 200 μm, Release sheet has a basis weight of 5
A combination in which synthetic resin and the like are laminated on both sides of a pulp paper of 0 to 150 g / m ² to a thickness of 5 to 40 μm, respectively, and a Gurley stiffness of 1 to 15 mN is preferable.

The adhesive used in the present invention includes, for example, acrylic acid, mainly (meth) acrylate,
Acrylic pressure-sensitive adhesives copolymerized with methacrylic acid, vinyl acetate, styrene, etc., and rubbers containing natural rubber, synthetic rubbers such as styrene-butadiene copolymers, styrene-isoprene copolymers as a main component and compounding a tackifier, etc. An adhesive is used. These adhesives can be used in the form of a solvent type, an aqueous emulsion type, a hot melt type, a liquid curable type and the like.
The composition and form are not particularly limited, but a resin comprising a (meth) acrylate copolymer as a main component is preferable as a resin constituting the pressure-sensitive adhesive layer.

The rubber-based pressure-sensitive adhesives include, for example, natural rubber, isoprene rubber, styrene-butadiene copolymer, styrene-
It is prepared by blending the following various additives with elastomers such as isoprene copolymer, butyl rubber, styrene / ethylene / butylene / styrene copolymer, and polyisobutylene. Natural resin such as rosin to impart tackiness,
Modified rosin, rosin and modified rosin derivatives, polyterpene resin, terpene modified substance, aliphatic hydrocarbon resin, cyclopentadiene resin, aromatic petroleum resin, phenol resin, alkyl-phenol-acetylene resin, cumarone- Indene resin, vinyl toluene-α-
Tackifiers such as methylstyrene copolymers and various plasticizers, softeners such as oils, crosslinking agents for cohesiveness control, anti-aging agents for preventing deterioration, ultraviolet absorbers, stabilizers, Other fillers, pigments, colorants, antistatic agents, and the like can be added as needed. These may be used in combination of two or more as necessary.

The acrylic pressure-sensitive adhesive is obtained by copolymerizing (meth) acrylic acid ester or another copolymerizable vinyl monomer. (Meth) acrylic acid esters are (a) alkyl group, (b) alkoxyl group, (c) phenyl group, (d)
Benzyl group, (e) ethylene oxide group, (f) tetrahydrofurfuryl group, (g) amide group, (h) carboxyl group,
and those having (i) a hydroxyl group, (j) a phosphate group, (k) a sulfonic acid group, (l) an amino group, and (m) an epoxy group. (A) Examples of the (meth) acrylate having an alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and butyl (meth) acrylate. Acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isoamyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, isobutyl ( (Meth) acrylate and the like. Among them, those having a higher alkyl group contribute to the improvement of the adhesiveness, and among them, 2-ethylhexyl acrylate and butyl acrylate are preferably used. Further, those having a lower alkyl group contribute to improvement in cohesiveness. (B) As those having an alkoxyl group, methoxyethyl (meth) acrylate, ethoxyethyl (meth)
Acrylate, butoxyethyl (meth) acrylate,
Phenoxyethyl (meth) acrylate and the like. (C) Examples of those having a phenyl group include phenyl (meth) acrylate, p-tert-butylphenyl (meth) acrylate, o-biphenyl (meth) acrylate and the like. (D) Examples of those having a benzyl group include benzyl (meth) acrylate. (E) Examples of those having a tetrahydrofurfuryl group include tetrahydrofurfuryl (meth) acrylate.

(F) As those having an ethylene oxide group, diethylene glycol (meth) acrylate,
Methoxydiethylene glycol (meth) acrylate,
Examples include methoxypolyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, and phenoxypolyethylene glycol (meth) acrylate. (G) Those having an amide group include (meth) acrylamide, N-methylol (meth) acrylamide, N
-Methoxymethyl (meth) acrylamide, N, N'-
Methylene bis (meth) acrylamide and the like can be mentioned.
Examples of the functional group-containing monomer include (h) acrylic acid, methacrylic acid, itaconic acid, 2-methacryloyloxysuccinic acid, 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, -Methacryloyloxyethyl hexahydrophthalic acid. (I) Examples of those having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-chloro-2-hydroxyethyl (meth) acrylate. And the like.

(J) As those having a phosphate group, 2
-Methacryloyloxyethyl diphenyl phosphate (meth) acrylate, trimethacryloyloxyethyl phosphate (meth) acrylate, triacryloyloxyethyl phosphate (meth) acrylate and the like. (K) Examples of those having a sulfonic acid group include sodium sulfopropyl (meth) acrylate, sodium 2-sulfoethyl (meth) acrylate, sodium 2-acrylamido-2-methylpropanesulfonate, and 3-allyloxy-2-hydroxypropanesulfone. Acid sodium and the like.

(L) Examples of those having an amino group include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate, and methacryloyloxyethyltrimethylammonium chloride (meth). Acrylate and the like. (M) Examples of those having an epoxy group include glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate. (N) Other copolymerizable vinyl monomers include:
Vinyl acetate, fatty acid vinyl such as vinyl propionate, styrene, maleic acid, fumaric acid, vinyl sulfonic acid,
Styrenesulfonic acid and the like can be exemplified.

Further, in order to adjust adhesiveness and cohesiveness, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1, 3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) Polyfunctional monomers such as acrylate, N, N'-methylenebisacrylamide and divinylbenzene can be copolymerized. These acrylic resins are polymerized by an arbitrary method such as an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, a bulk polymerization method, or the like, and preferably, an emulsion polymerization method or a solution polymerization method is used.

Furthermore, various additives similar to the rubber-based pressure-sensitive adhesives, for example, natural resins such as rosin, modified rosin, derivatives of rosin and modified rosins, polyterpene-based resins, modified terpene, aliphatic-based resins for improving the adhesive properties Hydrocarbon resin, cyclopentadiene resin, aromatic petroleum resin, phenol resin, alkyl-phenol-acetylene resin,
Coumarone-indene resin, tackifiers including vinyl toluene-α-methylstyrene copolymer, etc., various plasticizers, softeners such as oils, crosslinking agents for adjusting cohesiveness, for improving coatability Thickeners, wetting agents, antioxidants for preventing deterioration, stabilizers, ultraviolet absorbers, other fillers, pigments, coloring agents, antistatic agents, and the like can be added to the acrylic resin as required. These may be used in combination of two or more as necessary.

Examples of the crosslinking agent include (a) an epoxy compound,
(B) aziridine type, (c) isocyanate type, (d)
There are metal types, and (a) epoxy type includes sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl-tris (2-hydroxyethyl) isocyanurate, glycerol Polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol-S-diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol di Glycidyl ether, propylene glycol diglycidyl ether, diglycidyl adipate, - phthalic acid diglycidyl ether can be exemplified. (B) Examples of aziridine-based compounds include: (C) As the isocyanate-based, toluylene diisocyanate, 2,4-toluylene diisocyanate dimer, naphthylene-1,5-diisocyanate, o-
Toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate,
Hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and polyisocyanate prepolymer can be exemplified. (D) As a metal system, M
metal oxides containing g ²⁺ , Ca ²⁺ , Zn ²⁺ , Al ³⁺ ,
Examples thereof include metal salts and metal chelate compounds. In the present invention, the pressure-sensitive adhesive preferably contains a (meth) acrylate copolymer as a main component. The pressure-sensitive adhesive sheet of the present invention is obtained by providing a pressure-sensitive adhesive layer on at least one surface of a sheet-shaped surface substrate, and laminating a release sheet thereon. here,
An adhesive sheet having a pressure-sensitive adhesive layer formed on one surface of a sheet surface substrate and having a recording layer on the opposite surface of the surface substrate is preferable, and the recording layer is preferably an inkjet recording layer.

The pressure-sensitive adhesive sheet of the present invention has a sheet-like surface substrate and a release sheet, JAPAN TAPPI No. Gurley stiffness specified in 40 is in the range of 0.2 to 15 mN, respectively, and (i) the peeling force (irrespective of the flow direction) when peeling the release paper from the surface substrate is reduced. (Preferably, a release agent and / or an adhesive is selected so that the release force is 0.9 to 7.8 N / m, more preferably 0.9 to 5.5 N / m), (ii) an adhesive sheet At the time of manufacturing, apply a strong stress to the adhesive sheet surface, (iii) above (i)
After leaving the pressure-sensitive adhesive sheet at a relative humidity of 50% and a temperature of 23 ° C. for 24 hours, for example, by employing both (ii) and (ii),
When the relative humidity was changed to 20% and left for 72 hours, the slip amount (| N |) of the release sheet and the surface substrate including the pressure-sensitive adhesive layer in the CD direction (| N |) and the release sheet CD direction length (L) were determined. Formula (I) can be satisfied. | N | /L×100≧0.05% (I) Preferably, the value of formula (I) is at least 0.1%, and the upper limit is preferably 1.6%. More preferably 0.1 to
0.5%. More preferably, a relative humidity of 50%,
After leaving at a temperature of 23 ° C. for 24 hours, when the relative humidity was changed to 20% and left for 24 hours, the amount of slip (| N |) of the release sheet and the surface substrate including the adhesive layer in the CD direction (| N |) And the length (L) of the release sheet in the CD direction preferably satisfies the formula (I). In this way, the faster the saturation time of the slip,
The dimensional difference between the sheet-like surface base material and the release sheet due to temperature and humidity can be quickly reduced, and curling can be prevented well.

As a method of constructing the pressure-sensitive adhesive sheet of the present invention, a pressure-sensitive adhesive is applied on the surface of the release layer of the release sheet, and if necessary, dried to form a pressure-sensitive adhesive layer. There is a method in which a pressure-sensitive adhesive is applied by laminating or applying a pressure-sensitive adhesive to the back surface of the surface substrate, and then dried if necessary to form a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is bonded to the surface of the release layer of the release sheet to finish. Among these, the pressure-sensitive adhesive layer is provided on the release sheet, and then the sheet-like surface base material is laminated on the pressure-sensitive adhesive layer, and then the sheet-like surface base material surface on which the pressure-sensitive adhesive layer is not provided is brought into contact with a roll. Preferred is a method including applying stress to the pressure-sensitive adhesive sheet. In particular, it is preferable that the finished pressure-sensitive adhesive sheet is applied alone or in combination with a device such as a decurler or a roll machine such as a cutting machine to apply a strong external force with a high tension. That is, the roll diameter is 20 mm or less (preferably,
With a roll having a roll diameter of 5 to 15 mm, the holding angle between the roll and the adhesive sheet (the angle connecting each contact point of the adhesive sheet and the roll and the center of the roll) is 90 to 180 ° (more preferably 120 to 180 °), It is preferable to apply a sufficient external force (stress) to the pressure-sensitive adhesive layer. In particular, it is preferable to apply stress to the adhesive sheet using a decurler. Further, the surface substrate is a sheet in which resin layers are formed on both sides of a paper support, and the support constituting the release sheet is a film, or the surface substrate is a film, and the support constituting the release sheet is a film. The effect of the present invention is great when the body is a sheet in which resin layers are formed on both sides of a paper support.

As a device for applying the pressure-sensitive adhesive, for example, a reverse roll coater, knife coater, bar coater, slot die coater, air knife coater, reverse gravure coater, vario gravure coater and the like are appropriately used. The coating amount of the pressure-sensitive adhesive is adjusted in the range of 5 to 70 g / m ^{2 on} a dry weight basis. By the way, 5g /
If it is less than m ² , the adhesive performance of the resulting pressure-sensitive adhesive sheet will be insufficient, while if it exceeds 70 g / m ² , the pressure-sensitive adhesive may overflow or cause cohesive failure at the time of peeling.
More preferably, it is 20 to 60 g / m ² . 60 g / m ²
No improvement is observed in the adhesive strength after sticking even if it exceeds.

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" indicate "parts by weight of solid content" and "% by weight of solid content", respectively, unless otherwise specified.

Example 1 (Production of surface base material) Freeness is 250 ml · CSF
(Canada Standard Freeness, same hereafter) LBKP 80%
And NBKP 20% were mixed to prepare a pulp slurry having a concentration of 0.5%. In this pulp slurry, cationized starch 2.0%, alkyl ketene dimer 0.4%, anionized polyacrylamide resin 0.
1% and 0.7% of a polyamide polyamine epichlorohydrin resin were added, and sufficiently dispersed by stirring. Also,
After dispersion, the pH was adjusted to 7.5 with sodium hydroxide.

The pulp slurry prepared as above is paper-made by a fourdrinier machine, passed through a drier, a size press, and a machine calender, and has a basis weight of 140 g / m ² , a tightness of 1.0 g / m ³ and a water content of 8.0%. A pulp paper substrate was produced. The size press liquid used in the size press step was prepared by mixing carboxy-modified polyvinyl alcohol and sodium chloride at a weight ratio of 2: 1 and applying the mixture to both sides of paper at 1.2 g / m ^2. Pulp paper was prepared.

The pulp paper thus obtained was subjected to a corona discharge treatment on both sides, and the following polyolefin resin composition (1) obtained by mixing and dispersing the mixture with a Banbury mixer was applied to the felt side of the pulp paper in an amount of application. 22 g / m ^2, and (2) the resin composition for the back surface is applied to the wire surface side at 22 g / m ² by a melt extruder having a T-type die, and the surface is mirror-finished. And cooled and solidified with a cooling roll having a thickness of 130 μm to produce a sheet-like support having a thickness of 130 μm.

Next, an ink receiving layer having the following composition (3) was coated on the surface of the obtained sheet-like support with a bar coater at a coating amount of 15%.
g / cm ² to obtain a surface substrate for inkjet recording.

(1) Polyolefin composition Linear low-density polyethylene resin (density 0.926 g / c
m ³ , melt index 20 g / 10 min) 35 parts by weight, low density polyethylene resin (density 0.919 g / cm)
³ , melt index 2 g / 10 min) 50 parts by weight, anatase type titanium dioxide (trade name: A-20, manufactured by Ishihara Sangyo Co., Ltd.) 15 parts by weight, zinc stearate 0.1 part by weight, antioxidant (trade name: 0.03 parts by weight of Irganox 101 (manufactured by Ciba Geigy), ultramarine (trade name: Aoguchi ultramarine N)
o. 2000, manufactured by Daiichi Kasei Co., Ltd.) 0.09 parts by weight, optical brightener (trade name: UVITEX OB, manufactured by Ciba Geigy) 0.3 parts by weight

(2) Backside resin composition High density polyethylene resin (density 0.954 g / cm^Three,
Melt index 20g / 10min) 65 parts by weight, low density
Degree polyethylene resin (density 0.924g / cm ^Three, Mel
Index 4 g / 10 min) 35 parts by weight

(3) Composition of ink receiving layer Acid-treated gelatin (pig skin gelatin, jelly strength 200 Bl
oom) 100 parts by weight, polydiallyldimethylammonium chloride (trade name: PAS-
H, manufactured by Nitto Boseki Co., Ltd.), 10 parts by weight, zirconyl ammonium carbonate (trademark: Zircosol AC-7) as a crosslinking agent,
2 parts by weight of Daiichi Kagaku Kagaku Kogyo Co., Ltd., 0.001 parts by weight of polyoxyethylene polyoxypropylene condensate (trade name: Adecapluronic L-64, manufactured by Asahi Denka Kogyo KK)

(Preparation of Release Sheet) A 38 μm thick polyethylene terephthalate film (support) was coated on one side with a thermosetting toluene-diluted release agent (trade name: KS-845, manufactured by Shin-Etsu Chemical Co., Ltd., 100% by weight) Product name: PL-
56, 2 copies made by Shin-Etsu Chemical Co., Ltd., trade name: SD-720
0, a 0.5% mixture of Dow Corning Toray Co.) was applied to a bar coater at a concentration of 0.2 g / m ² and dried to obtain a release sheet.

(Preparation of adhesive) After charging 100 parts of ethyl acetate and 0.3 part of azobisisobutylnitrile into a reactor equipped with a stirrer, a cooling pipe, a dropping funnel and a nitrogen introducing pipe, the temperature in the system was reduced to about The temperature was raised to 80 ° C. Then, 85 parts of butyl acrylate, 8 parts of 2-ethylhexyl acrylate, 6.7 parts of vinyl acetate,
From a dropping funnel charged with a mixed solution consisting of 0.3 parts of hydroxyethyl methacrylate, the mixed solution was dropped into the system in about 3 hours under a nitrogen stream, and further kept at the same temperature for 1 hour to carry out the polymerization reaction. The reaction was completed, and an acrylic polymer having a solid content of 50% was obtained at a yield of 99%.

To 100 parts of this acrylic polymer, 2 parts of a polyisocyanate-based crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) was added, and an adhesive (coating liquid) was added.
Finished.

The pressure-sensitive adhesive prepared as described above was applied to the obtained release sheet with a reverse roll coater so that the pressure-sensitive adhesive became 20 g / m ² and dried, and the surface substrate prepared as described above was bonded. An adhesive sheet was obtained.

The obtained pressure-sensitive adhesive sheet is rolled with a roll having a diameter of 12 mm, and the holding angle of the pressure-sensitive adhesive sheet (the angle connecting the contact points of the pressure-sensitive adhesive sheet and the roll to the center of the roll) is set to 180 °, and a constant external force is applied to the pressure-sensitive adhesive layer. And then cut to A4 size
A 4-sheet cut product was obtained. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TA
PPI paper pulp test method No. It measured according to the test method prescribed | regulated to 40-83. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 2.5 mN, and the Gurley stiffness of the release sheet was 0.23 mN. After leaving the surface substrate including the pressure-sensitive adhesive layer and the release sheet at 23 ° C. and a relative humidity of 50% for 24 hours, the environment was changed to 23 ° C. and a relative humidity of 20%,
After 24 hours, the difference in the expansion and contraction ratio between the surface substrate and the release sheet was measured. The difference in expansion and contraction ratio between the surface substrate including the pressure-sensitive adhesive layer and the release sheet was 0.30%.

Example 2 An adhesive sheet and an A4 sheet cut product were obtained in the same manner as in Example 1 except that the following adhesive was used. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. 40-8
It measured by the test method prescribed in 3. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 2.4 mN, and the Gurley stiffness of the release sheet was 0.23 mN (the difference in stretch ratio was 0.32%). (Preparation of adhesive) 70 parts of water, 0.2 part of ammonium persulfate as a polymerization initiator and 1 part of sodium dodecylbenzenesulfonate were charged into an autoclave equipped with a stirrer, a temperature controller and a reflux condenser, and 70 The temperature was raised to ° C.
Subsequently, 100 parts of a monomer mixture consisting of 1 part of acrylic acid, 95 parts of 2-ethylhexyl acrylate and 4 parts of methyl methacrylate, 0.05 part of n-butyl mercaptan as a molecular weight regulator, 60 parts of water, and dodecylbenzene sulfonic acid as an emulsifier After adding 0.5 part of sodium, the mixture was stirred and emulsified to prepare a pre-emulsion.

This pre-emulsion was stirred at 80 ° C. while being continuously added to the autoclave over a period of 8 hours to carry out emulsion polymerization. Thereafter, stirring was further continued at 80 ° C. for 2 hours to complete the copolymer. Mix, solids 50
% Of an acrylic polymer was obtained with a yield of 99%.

The acrylic polymer 10 obtained by the above method
To 0 part, a polyglycidyl compound (trade name: Denacol EX-421, manufactured by Nagase Kasei Kogyo Co., Ltd.) was added in an amount of 0.1 part.
5 parts, and 100 parts by weight of the solid content of the adhesive, a temper phenol resin (trade name: Tamanol E-1)
00, manufactured by Arakawa Chemical Industry Co., Ltd., solid content concentration = 52.9
%) Was added to finish the adhesive.

Example 3 An adhesive sheet and an A4 sheet cut product were obtained in the same manner as in Example 1 except that the following adhesive was used. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. 40-8
It measured by the test method prescribed in 3. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 2.4 mN, and the Gurley stiffness of the release sheet was 0.23 mN (the difference in stretch ratio was 0.29%).

(Production of pressure-sensitive adhesive) A monomer mixture of 90 parts of 2-ethylhexyl acrylate, 6.5 parts of vinyl acetate, 3 parts of methyl methacrylate, and 0.5 part of acrylic acid was added to
A pre-emulsion was prepared by adding and stirring an emulsifier aqueous solution containing 1.0 part of a nonionic surfactant and 30 parts of ion-exchanged water. An emulsifier aqueous solution containing 1.0 part of an anionic surfactant, 0.3 part of ammonium persulfate, 0.3 part of sodium acetate, and 30 parts of ion-exchanged water was charged into a reaction vessel equipped with a stirrer, a thermometer, and a cooling pipe. The temperature of the solution was increased to 75 ° C. while stirring with passing nitrogen gas, 5/100 of the pre-emulsion was added, and the initial polymerization was carried out for 30 minutes. The polymerization was carried out while maintaining the temperature at ° C. After the completion of the dropwise addition, the mixture was kept at 80 ° C. to carry out late-stage polymerization to obtain a copolymer emulsion.
To 100 parts of the obtained pressure-sensitive adhesive, 10 parts of an emulsion type rosin-based tackifier having a resin softening point of 160 ° C. (trade name: Superester E-650, manufactured by Arakawa Chemical Co., Ltd.) was blended, and an alkali thickening type thickener was added. After mixing the wetting agent, the viscosity was neutralized with ammonia water (concentration 25%) 5000 mpa
s to obtain an adhesive.

Example 4 An adhesive sheet and an A4 sheet were cut in the same manner as in Example 1 except that a polyester-based synthetic paper 50 μm (trade name: Crisper G2311, manufactured by Toyobo Co., Ltd.) and the following release sheet were used as the surface substrate. Product was obtained. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. 40-8
It measured by the test method prescribed in 3. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 1.1 mN, and the Gurley stiffness of the release sheet was 4.6 mN.
0.33%. ).

(Preparation of Release Sheet) Freeness is 500
After making a high quality paper of 110 g / m ² in U.S. m. with 80% of LBKP and 20% of NBKP of ml · CSF, polyethylene was laminated on one side thereof to a thickness of 20 μm by a film extruder to obtain a single-sided polyethylene laminated release paper base paper.

A heat-curable solventless release agent (addition reaction type release agent: trade name "KNS-320" 1) is applied to the polyethylene-laminated surface of the obtained single-sided polyethylene-laminated release paper base paper.
Platinum catalyst agent: trade name “PL-56” for 2 parts
Part of the mixture added, manufactured by Shin-Etsu Chemical Co., Ltd.) using an offset gravure coater so as to have a concentration of 0.5 g / m ² , cured with hot air, and gravure on the surface opposite to the surface on which the thermosetting solventless release agent was applied. The paper was humidified by a coater so that the moisture content of the base paper became 7.5% to obtain a single-sided polyethylene laminate release sheet. Further, polyethylene was laminated to a thickness of 20 μm on the surface opposite to the surface on which the thermosetting solvent-free release agent was applied, using a film extruder to obtain a release sheet.

Example 5 (Preparation of surface base material) NBKP 25% with a freeness of 550 ml / CSF and L with a freeness of 560 ml / CSF
Kaolin was added to a pulp slurry containing 75% BKP so that the paper ash content was 5.0%, and a rosin size as a sizing agent was 1.5% based on the absolutely dried pulp, and a 2.0% sulfate band was added. Was added. This pulp slurry was paper-made by a fourdrinier multi-cylinder cylinder dryer paper machine and processed by a 4-stage super calender to obtain a support of 85 g / m ² .

On the surface of the support obtained in the production of the support,
(4) 55 parts, (5) 115 parts, (6) 80 parts, 10%
A coating liquid obtained by mixing and stirring 80 parts of an aqueous polyvinyl alcohol solution and 35 parts of calcium carbonate was coated and dried so that the coating amount after drying was 6 g / m ² , to obtain a recording layer. On this recording layer, the coated amount of (7) after drying was 5 g / m.
After coating and drying so that ² to obtain a heat-sensitive recording surface substrate subjected to calendering treatment. (4) 3- (N-ethyl-N-isoamyl) amino-6
-Methyl-7-phenylaminofluoran 10 parts, 5%
A composition comprising 5 parts of an aqueous methylcellulose solution and 40 parts of water was pulverized by a sand mill until the average particle diameter became 3 μm. (5) 30 parts of 4-hydroxy-4'-isopropoxydiphenyl sulfone, 5 parts of a 5% aqueous methylcellulose solution,
And 80 parts of water were pulverized by a sand mill until the average particle diameter became 3 μm. (6) 1,2-di (3-methylphenoxy) ethane 20
Of a 5% aqueous solution of methylcellulose and 55 parts of water were pulverized by a sand mill until the average particle diameter became 3 μm. (7) 200 parts of 10% acetoacetyl group-modified polyvinyl alcohol aqueous solution, kaolin (trade names: UW-90, E
MC) 100 parts, 30% zinc cetearate dispersion 3
A composition comprising 0 parts and 100 parts of water was mixed and stirred to obtain a coating liquid.

(Production of adhesive) A monomer mixture of 91 parts of 2-ethylhexyl acrylate, 5.5 parts of vinyl acetate, 3 parts of methyl methacrylate, and 0.5 part of acrylic acid was added to
A pre-emulsion was prepared by adding and stirring an emulsifier aqueous solution containing 1.0 part of a nonionic surfactant and 30 parts of ion-exchanged water. An emulsifier aqueous solution containing 1.0 part of an anionic surfactant, 0.3 part of ammonium persulfate, 0.3 part of sodium acetate, and 30 parts of ion-exchanged water was charged into a reaction vessel equipped with a stirrer, a thermometer, and a cooling pipe. The temperature of the solution was increased to 75 ° C. while stirring with passing nitrogen gas, 5/100 of the pre-emulsion was added, and the initial polymerization was carried out for 30 minutes. The polymerization was carried out while maintaining the temperature at ° C. After the completion of the dropwise addition, the mixture was kept at 80 ° C. to carry out late-stage polymerization to obtain a copolymer emulsion.
To 100 parts of the obtained pressure-sensitive adhesive, 10 parts of an emulsion type rosin-based tackifier having a resin softening point of 160 ° C. (trade name: Superester E-650, manufactured by Arakawa Chemical Co., Ltd.) was blended, and an alkali thickening type thickener was added. After mixing the wetting agent, the viscosity was neutralized with ammonia water (concentration 25%) 5000 mpa
s to obtain an adhesive.

[0045] (Peeling Preparation of Sheet) basis weight 63 g / thermosetting one side of glassine paper m ² toluene diluted peelable silicone (trade name: SRX345, manufactured by Dow Corning Toray Co., relative to 100 wt%, trade name : SRX212, manufactured by Dow Corning Toray Co., Ltd., a mixture obtained by adding 0.6 parts) A 7% solution was applied by a bar coater to 0.8 g / m ² ,
After drying, a release sheet was obtained.

The pressure-sensitive adhesive prepared as described above was applied to the obtained release sheet with a reverse roll coater so as to have a weight of 20 g / m ² , dried, and then the surface base material prepared as described above was laminated. An adhesive sheet was obtained. The obtained pressure-sensitive adhesive sheet was cut in the same manner as in Example 1 after applying a constant external force to the pressure-sensitive adhesive layer to obtain an A4 sheet cut product. Also,
Removing the release sheet from the obtained A4 sheet cut product,
The Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J. Mol. TAPPI paper pulp test method No. 4
It was measured by the test method specified in 0-83. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 1.5 mN, and the Gurley stiffness of the release sheet was 1.2 mN (difference in expansion and contraction was 0.17%).

Example 6 An adhesive sheet and an A4 sheet cut product were obtained in the same manner as in Example 1 except that the following surface substrate and release sheet were used. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. It measured by the test method prescribed | regulated to 40-83. Gurley stiffness of the surface substrate including the adhesive layer is 1.3 m
N, and the Gurley stiffness of the release sheet was 4.6 mN (the difference in expansion and contraction ratio was 0.42%).

(Preparation of Surface Substrate) As a support, a base paper having a basis weight of 77 g / m ² was made from a high-whiteness wood pulp as a raw material, and a coating liquid for an ink receiving layer having the following composition was dried. Was applied to be 15 g / m ² and dried to obtain a surface substrate for inkjet recording.

(Blending of ink receiving layer) Cationic resin: 65 parts of diallyldimethyl quaternary ammonium hydrochloride aqueous solution (trade name: Unisense CP101, average molecular weight: 20,000, manufactured by Senka Co., Ltd.) Ink absorbing pigment: amorphous silica (product Name: Fine Seal X-45, manufactured by Tokuyama Corporation 100 parts, Binder: Polyvinyl alcohol (trade name: PVA10)
5, Kuraray Co., Ltd.) 200% aqueous solution with 10% solid content

(Preparation of release sheet) Freeness is 500
After making a high quality paper of 110 g / m ² in U.S. m. with 80% of LBKP and 20% of NBKP of ml · CSF, polyethylene was laminated on one side thereof to a thickness of 20 μm by a film extruder to obtain a single-sided polyethylene laminated release paper base paper.

A heat-curable solventless release agent (addition reaction type release agent: trade name "KNS-320" 1) is applied to the polyethylene-laminated surface of the obtained single-sided polyethylene-laminated release paper base paper.
Platinum catalyst agent: trade name “PL-56” for 2 parts
Part of the mixture added, manufactured by Shin-Etsu Chemical Co., Ltd.) using an offset gravure coater so as to have a concentration of 0.5 g / m ² , cured with hot air, and gravure on the surface opposite to the surface on which the thermosetting solventless release agent was applied. The paper was humidified with a coater so that the moisture content of the base paper became 7.5% to obtain a single-sided polyethylene laminate release paper. Further, polyethylene was laminated to a thickness of 20 μm on the surface opposite to the surface on which the thermosetting solvent-free release agent was applied, using a film extruder to obtain a release sheet.

Example 7 An adhesive sheet and an A4 sheet cut product were obtained in the same manner as in Example 1 except that the following surface substrate was used. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. 40-
It was measured by the test method specified in No. 83. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 1.7 mN, and the Gurley stiffness of the release sheet was 0.23 mN (the difference in stretch ratio was 0.30%).

(Preparation of surface substrate) Freeness is 480 m
1 part of LBKP 100% pulp slurry, 20 parts of talc as filler, 1.5 parts of rosin emulsion sizing agent,
Two parts of a sulfuric acid band were added, and the mixture was diluted with white water to prepare a stock having a pH of 5.3 and a solid content of 1.1%. The stock is paper-made using a fourdrinier paper machine, and then an oxidized starch having a solid content of 8% (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) is applied at a dry weight of 4.0 g / m ^2. It was applied by a size press device, dried, and smoothed with a machine calender at a smoothness of 80 seconds / 10 ml to obtain a surface substrate for electrophotography with a rice tsubo of 98 g / m ² .

Example 8 An adhesive sheet and an A4 sheet cut product were obtained in the same manner as in Example 1 except that the following surface substrate and release sheet were used. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. It measured by the test method prescribed | regulated to 40-83. The Gurley stiffness of the surface substrate including the adhesive layer is 0.9 m
N, and the Gurley stiffness of the release sheet was 0.9 mN (the difference in expansion and contraction was 0.25%).

(Preparation of Surface Substrate) As a support, a base paper having a basis weight of 40 g / m ² was made from a high-whiteness wood pulp as a raw material, and a coating liquid for an ink receiving layer having the following composition was dried. Was applied to be 15 g / m ² and dried to obtain a surface substrate for inkjet recording.

(Blending of ink receiving layer) Cationic resin: 65 parts of diallyldimethyl quaternary ammonium hydrochloride aqueous solution (trade name: Unisense CP101, average molecular weight: 20,000, manufactured by Senka Co., Ltd.) Ink absorbing pigment: amorphous silica (product Name: Fine Seal X-45, manufactured by Tokuyama Co., Ltd. 100 parts Binder: polyvinyl alcohol (trade name: PVA10)
5, Kuraray Co., Ltd.) 200% aqueous solution with 10% solid content

(Preparation of Release Sheet) The coating liquid was prepared by preparing an undercoat layer having the following composition and was coated on a fine base paper having a basis weight of 40 g / m ² to a dry weight of 5 g / m ^2. A release base paper having a water content of 5% after coating and drying with a coater was obtained. Component weight Kaolin (trade name: HT clay, manufactured by Engelhard) 100 parts Acrylic copolymer (trade name: Iodozol MR-96, manufactured by Kanebo NSC, glass transition temperature -15 ° C, ionicity: nonionic) 25 Part Polyvinyl alcohol (trade name: PVA203, manufactured by Kuraray) 120 parts Oxidized modified starch (trade name: Oji Ace A, manufactured by Oji Constarch) 25 parts Ammonium stearate (trade name: Nopco DC-100-A, manufactured by San Nopco) 2 parts A thermosetting toluene-diluted light release silicone (trade name: SRX345, manufactured by Dow Corning Toray Co., Ltd., 100% by weight; trade name: SRX212, manufactured by Dow Corning Toray Co., Ltd .; 0.6%) part added mixture) 7% solution coating with a bar coater to a dry weight is 0.9 g / m ² and dried to peel Sea It was obtained.

Example 9 An adhesive sheet and an A4 sheet cut product were obtained in the same manner as in Example 1 except that the following adhesive was used. Further, the release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J.I. TAPPI paper pulp test method No. 40-8
It measured by the test method prescribed in 3. The Gurley stiffness of the surface base material including the pressure-sensitive adhesive layer was 2.30 mN, and the Gurley stiffness of the release sheet was 0.23 mN (the difference in stretch ratio was 0.30%).

[Production of Adhesive] 100 parts of ethyl acetate was charged into a reactor equipped with a stirrer, a cooling pipe, a dropping funnel and a nitrogen introducing pipe, and then the temperature was raised until the temperature in the system reached about 80 ° C. Then, from a dropping funnel in which a mixed solution consisting of 97 parts of 2-ethylhexyl acrylate and 3 parts of carboxylic acid was previously charged, the mixed solution was dropped into the system in about 3 hours under a nitrogen stream, and further added for 1 hour. The polymerization reaction was completed while maintaining the temperature, and an acrylic polymer having a solid content of 50% was obtained at a yield of 99%.

To 100 parts of this acrylic polymer, 3 parts of a polyisocyanate crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) was added, and an adhesive (coating liquid) was added.
Finished.

Comparative Example 1 An A4 sheet cut product was obtained in the same manner as in Example 3 except that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet was cut into A4 size without applying any external force.

The release sheet was removed from the obtained A4 sheet cut product, and the Gurley stiffness of the surface substrate including the removed release sheet and the pressure-sensitive adhesive layer was determined according to J. Org. TAPPI paper pulp test method No. It measured by the test method prescribed | regulated to 40-83. Gurley stiffness of the surface base material including the adhesive layer is 2.5 m
N, and the Gurley stiffness of the release sheet was 0.23 mN (the difference in expansion and contraction was 0.29%).

[Evaluation] [Measurement of the amount of slip (| N |) in the CD direction between the surface substrate including the pressure-sensitive adhesive layer and the release sheet and the length (L) of the release sheet in the CD direction, FIG. 9, the A4 sheet cut product obtained in Comparative Example 1 was allowed to stand for 24 hours in an environment of 23 ° C./50% RH, and then the end surface dimensional difference (A ₀ ) between the surface substrate and the release sheet in the CD direction and the release Sheet CD length (L), 2
After changing to an environment of 3 ° C./20% RH, C after 24 hours
The difference in the end face size between the surface base material and the release sheet in the D direction (A ₂₄ ) and the difference in end face size between the surface base material and the release sheet in the CD direction after 72 hours (A ₇₂ ) were measured. Amount of slip between the surface substrate including the layer and the release sheet in the CD direction (|
N |) and the ratio (| N |
/ L × 100) was calculated.

(23 ° C./20% RH / after 24 hours) | N ₂₄ | / L × 100 In the formula, N ₂₄ = A ₂₄ −A ₀ : sliding amount between the pressure-sensitive adhesive layer and the release sheet, (mm) L: Release sheet length (mm)

(23 ° C./20% RH / after 72 hours) | N ₇₂ | / L × 100 In the formula, N ₇₂ = A ₇₂ −A ₀ : sliding amount between the pressure-sensitive adhesive layer and the release sheet, (mm) L: Release sheet length (mm)

[Curl by Environmental Change] Examples 1 to 9,
The A4 sheet cut product obtained in Comparative Example 1 was heated at 23 ° C./50
After standing for 24 hours in an environment of% RH, 23 ° C / 20% RH
Was allowed to stand for 24 hours, and the degree of curl was evaluated according to the following criteria. (Evaluation method and evaluation criteria of curl) A4 size sample was placed on a flat sample table with the curled side on top, and how much the four corners of the sample floated from the sample table was measured and averaged. And evaluated according to the following criteria. ◎: 10 mm or less ：: More than 10 mm, 25 mm or less △: More than 25 mm, 40 mm or less ×: More than 40 mm

[0067]

[Table 1]

As is clear from the results shown in Table 1, after leaving the relative humidity at 50% for 24 hours, and then changing the relative humidity to 20%, the adhesive layer and the release sheet were left within 72 hours. When the slip occurs at the boundary between the pressure-sensitive adhesive layer and the release sheet, even if a dimensional difference occurs between the surface substrate and the release sheet due to an environmental change, the dimensional difference is alleviated due to the displacement between the pressure-sensitive adhesive layer and the release sheet. On the other hand, when no slippage occurs at the boundary between the pressure-sensitive adhesive layer and the release sheet within 72 hours as in Comparative Example 1, the dimensional difference between the surface base material and the release sheet due to an environmental change is determined by the pressure-sensitive adhesive layer and the release sheet. Curling occurs because it cannot be alleviated by the gap between them.

[0069]

According to the present invention, there is provided a pressure-sensitive adhesive sheet excellent in printer suitability, printing and recording suitability in which curling does not occur due to a bimetal effect of a surface substrate and a release sheet which frequently occur due to environmental changes and the like.

[Brief description of the drawings]

FIG. 1 shows a pressure-sensitive adhesive sheet at 50% relative humidity and a temperature of 23 ° C.
After leaving for 4 hours (a), changing the relative humidity to 20%, and leaving for 24 or 72 hours (b), sliding in the CD direction of the surface substrate including the release sheet and the adhesive layer in the CD direction. The measurement points of the amount (| N |) and the length (L) of the release sheet in the CD direction are shown.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tsuyoshi Yoshida 27-27, Hirade Industrial Park, Utsunomiya-shi, Tochigi F-term (reference) in Oji Paper Co., Ltd. DB03 FA01

Claims (9)

[Claims] A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer provided on at least one surface of a sheet-like surface substrate and a release sheet laminated thereon, wherein the sheet-like surface substrate containing the pressure-sensitive adhesive layer and the temperature and humidity of the release sheet And the J ratio of both
APAN TAPPI No. The Gurley stiffness specified at 40 is in the range of 0.2 to 15 mN, and the adhesive sheet is allowed to stand at 50% relative humidity and 23 ° C. for 24 hours, and then the relative humidity is changed to 20% for 72 hours. When left, the C of the surface substrate containing the release sheet and the pressure-sensitive adhesive layer
A pressure-sensitive adhesive sheet characterized in that the amount of slip (| N |) in the D direction and the length (L) of the release sheet in the CD direction satisfy the following formula (I). | N | /L×100≧0.05% (I) 2. The CD of the surface substrate including the release sheet and the pressure-sensitive adhesive layer when left for 24 hours at a relative humidity of 50% and a temperature of 23 ° C. for 24 hours, and then changed to a relative humidity of 20% for 24 hours. 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the slip amount in the direction (| N |) and the length (L) of the release sheet in the CD direction satisfy the following expression (I). 3. | N | /L×100≧0.05% (I) 3. The paper substrate according to claim 1, wherein one of the surface substrate and the support constituting the release sheet is a sheet in which resin layers are formed on both sides of a paper support, and the other is a film.
Or the pressure-sensitive adhesive sheet according to 2. 4. An adhesive layer is formed on one surface of a surface substrate,
The pressure-sensitive adhesive sheet according to claim 1, further comprising a recording layer on a surface opposite to the surface substrate. 5. The pressure-sensitive adhesive sheet according to claim 4, wherein the recording layer is an ink jet recording layer. 6. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive comprises a (meth) acrylate copolymer as a main component. 7. A pressure-sensitive adhesive layer is provided on a release sheet, and then a sheet-like surface substrate is laminated on the pressure-sensitive adhesive layer. Then, the surface of the sheet-like surface substrate on which the pressure-sensitive adhesive layer is not provided is rolled. The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein a stress is applied to the pressure-sensitive adhesive sheet by contacting the pressure-sensitive adhesive sheet. 8. The method according to claim 7, wherein the pressure-sensitive adhesive sheet is stressed using a decurler. 9. At least one of the rolls to be stressed has a roll diameter of 20 mm or less, and the angle connecting the two points of contact between the adhesive sheet and the roll and the center of the roll is 90-1.
The method according to claim 7 or 8, wherein a stress is applied to the pressure-sensitive adhesive sheet at 80 ° C.