JPH07102500A - Adhesive sheet - Google Patents

Abstract

PURPOSE:To provide an adhesive sheet excellent in the non-impact printer suitability of thermally print-fixing style. CONSTITUTION:An adhesive sheet comprises the laminate of a surface substrate, an adhesive agent, a releasing agent, a primer, and a releasing substrate. The surface substrate and/or the releasing substrate have the maximum value/ minimum value ratio of the strengths of penetrated microwaves in a value of 1.0-1.3. The main components of the primer comprise a pigment and a copolymer obtained by emulsion-copolymerizing at least one kind of (meth)acrylates each having a hydroxyl group in the molecule with at least one kind of other vinylic monomers capable of being copolymerized with the (meth)acrylate esters.

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, and more particularly to a pressure-sensitive adhesive sheet which is suitable for a non-impact printer of a print heat fixing system.

[0002]

2. Description of the Related Art Adhesive sheets are used for labels, stickers, stickers, etc.
It is used after being processed into patches. The general structure of such a pressure-sensitive adhesive sheet is formed by laminating a surface base material, a pressure-sensitive adhesive, a release agent, an undercoating agent, and a release paper substrate.

Paper, film, metal foil, etc. are used for the surface substrate, and high-density base paper such as glassine paper, clay-coated paper, polyethylene laminated base paper, etc. for the release paper substrate such as silicone compound and fluorine compound. The one coated with a release agent is used. On the other hand, as an adhesive,
Various adhesives such as rubber type, acrylic type, vinyl ether type emulsion type, solvent type and solventless type are used.

Usually, the pressure-sensitive adhesive sheet is subjected to slitter cutting processing, guillotine cutting processing, die cutting processing, etc. according to the application, but at the processing stage, the adhesive adheres to the slitter cutting blade, guillotine cutting blade, die cutting processing blade, etc. Is a problem. The adhesion of this adhesive reduces the work efficiency during cutting, and if the adhesive adhered to the blade is transferred to the sheet, smooth feeding cannot be performed when printing on the sheet or when attaching labels. , Is a cause of a significant decrease in work efficiency.

On the other hand, as a method of printing or recording on such an adhesive sheet, the demand for an adhesive sheet for non-impact printers for output is rapidly increasing with the rise of computers in the information society in recent years.
Conventionally, glassine paper has been used as a release paper substrate for adhesive sheets for this application. However, when high-beating, high-density paper such as glassine paper is processed with a non-impact printer, it behaves too sensitively to heat, and the paper deforms during heat fixing of the toner, As a result, stacking failure in the automatic folding stacker due to the tilting generated after printing has been a problem. Further, there has been a problem that the adhesive label comes off from the release paper substrate at the transfer portion and the fixing portion due to the peeling force and the adhesive sticks out from the sheet edge portion due to the adhesive.

[0006]

SUMMARY OF THE INVENTION The present invention improves stacking (stacking state) defects due to skewed sheets in a non-impact printer of a print heating and fixing system, and processes such as cutting and printing of an adhesive sheet. Provided is a pressure-sensitive adhesive sheet which is improved in label dropout and pressure-sensitive adhesive protrusion.

[0007]

The present invention provides a pressure-sensitive adhesive sheet comprising a surface base material, a pressure-sensitive adhesive, a release agent, an undercoating agent, and a release paper base laminated, wherein the surface base material and / or the release paper base is (Meth) acrylic acid having a ratio between the maximum value and the minimum value of the transmitted microwave intensity of 1.0 to 1.3 measured by a microwave measuring instrument and having a hydroxyl group in the molecule as a main component of the undercoating agent. A pressure-sensitive adhesive sheet comprising a pigment obtained by emulsion-copolymerizing at least one ester and at least one other vinyl monomer copolymerizable therewith.

[0008]

In the present invention, it is important to use the one in which the orientation of the fiber itself is eliminated by randomly arranging the fibers in the base paper as the base of the surface base material and / or the release paper base. That is, in a print heat fixing type non-impact printer, when the paper is folded in the thickness direction, it is significantly inclined to the left and right, which is based on the fact that the size changes as a result of thermal relaxation of stress strain. It is believed that Therefore, in order to prevent tilting, by controlling the operating conditions in the drying step in which the wire part and the dryer are arranged during papermaking, the stress strain of the nonuniformly made pulp fibers is minimized. There is a need. For this purpose, a method of making the fiber orientation angle close to 0 ° or completely randomizing the fibers to eliminate the fiber orientation itself is conceivable. However, the present inventors are keenly aware of the latter method. I have been studying and researching repeatedly.

First, to measure the fiber orientation of paper, a thermal expansion method, a mechanical breaking strength method, an X-ray diffraction method, an ultrasonic method, a birefringence method, a polarized infrared absorption method, an NMR method, a polarized fluorescence method, Although there are dielectric measurement methods and the like, in the present invention, a microwave method is employed, which allows non-contact, non-destructive, quick and simple measurement of a sample.

Here, the microwave is from 300 MHz to
It refers to electromagnetic waves in the frequency range of 50 GHz, and this wave range corresponds to the region where dielectric relaxation based on the orientation polarization of local molecular motions such as micro Brownian motion of polymer chains and twist of the main chain is observed. The molecular orientation is to be evaluated from the dynamic anisotropy. The specific measurement method is to rotate the sample while irradiating it with microwave polarization perpendicular to the sample surface set in the cavity resonator system, and change the angle between the reference direction of the sample and the plane of microwave polarization to transmit microwaves. The angle dependence of strength is obtained.

FIG. 1 shows the angle dependence of the intensity of the transmitted microwave in a machine-made paper (USPB 64 g / m ² ). The transmitted microwave intensity is low in the machine direction and high in the width direction (the interaction between the microwave and the molecule is strong in the direction in which the molecules are oriented, so that the transmitted microwave intensity is low in the oriented direction). From this, it is possible to know the orientation angle (deviation from the molecular chain axis and the reference direction), the maximum value and the minimum value of the transmitted microwave intensity (index of anisotropy).

FIG. 2 actually shows the orientation pattern of the paper according to the invention. As a result of repeated studies on the relationship between the degree of tilt and the alignment pattern, the present inventors have found that there is a certain relationship between the tilt angle δ and the ratio between the maximum value and the minimum value of the transmitted microwave intensity. .

That is, when the ratio between the maximum value and the minimum value of the transmitted microwave intensity is in the range of 1.0 to 1.3, preferably 1.0 to 1.2, the oblique inclination angle in the heat fixing type printer is It was found that when the angle was 20 ° or less, there was almost no jamming and smooth printing was possible. By the way, when the ratio of the maximum value and the minimum value of the transmitted microwave intensity is larger than 1.3, the inclination becomes severe, and when the ratio is 1.0, the fibers are completely unoriented, but the actual machine In the case of paper, it has some fiber orientation,
It is impossible to set it to 1.0 or less.

On the other hand, since the fiber orientation pattern is determined by the papermaking conditions of the machine, it is necessary to properly operate the machine. Possible means include machine speed, ratio of fiber suspension (paper stock) jet inflow speed to wire speed (J / W ratio), wire shake, placement of homing boards and weir boards, optimization of dandy rolls, etc. Can include the adjustment of the drying conditions in the dryer process and the strength of the draw. It is possible to bring the ratio between the maximum value and the minimum value of the transmitted microwave intensity close to 1 by appropriately combining one or more of these conditions. However, it is necessary to make adjustments in consideration of harmony with other properties such as texture of paper. The optimum values of the machine speed and the J / W ratio and the like differ depending on the type of machine, and it is impossible to comprehensively quantify them.

The base paper which is the base of the surface base material and the release paper base constituting the pressure-sensitive adhesive sheet of the present invention is a chemical pulp such as softwood or hardwood such as KP, SP, AP method and the like as raw material pulp composition, and SCP, BCTMP, CTMP, CG
Mechanical pulp such as P, RGP, SGP, TMP, and D
The main component is waste paper pulp such as IP, and if necessary, non-wood pulp such as hemp pulp, synthetic pulp, various synthetic fibers, and glass fiber are appropriately combined.

As the filler added to the papermaking raw material, for example, talc, kaolin, clay, calcined kaolin,
Calcium carbonate, aluminum hydroxide, titanium dioxide,
Mineral fillers such as magnesium silicate, magnesium sulfate, aluminosilicate, silica and bentonite, polystyrene resin particles, urea formalin resin particles and heat-expandable micro hollow particles, or non-heat expandable micro hollow particles and other organic fillers Is added appropriately.

Further, as papermaking additives, sizing agents such as anion, cationic rosin-based size, petroleum-based size, alkylketene dimer-based size, alkenyl succinic anhydride size and stearic anhydride-based size, and anionic and cationic properties. , Nonionic or amphoteric polyacrylamide polymers, polyethyleneimine and its derivatives,
Polyamide, polyamine and its derivatives, polyethylene oxide, vegetable gum, polyvinyl alcohol, cationic latex, cationic urea formalin resin, melamine formalin resin, polyamide resin and other organic compounds retention aid, drainage improver, paper strength A strengthening agent is used, and further, a dye, a pH adjusting agent, a pitch control agent,
A slime control agent, a defoaming agent, etc. can be appropriately selected and used as necessary.

The papermaking using the above-mentioned papermaking raw materials is carried out under acidic or neutral conditions by a Fourdrinier paper machine, a twin wire paper machine, a fourdrinier paper machine, a round net paper machine, a Yankee paper machine or the like.

As the release sheet which is a constituent of the pressure-sensitive adhesive sheet of the present invention, a release paper substrate provided with an undercoating agent and a release agent applied thereon is used. In this case, the undercoating agent is an emulsion obtained by emulsion-copolymerizing at least one kind of (meth) acrylic acid ester having a hydroxyl group in the molecule and at least one kind of other vinyl-based monomer copolymerizable therewith. The main component is a pigment added to.

Examples of the (meth) acrylic acid ester having a hydroxyl group in the molecule constituting the above specific emulsion include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 2
-Hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate,
Glycerol mono (meth) acrylate and the like,
At least one of these can be used.

These (meth) acrylic acid esters having a hydroxyl group remarkably improve the adhesiveness with the silicone resin, and the amount used is about 0.5% by weight or more based on the total amount of the monomers. It is good to do, but especially 3
When it is set to about 20% by weight, the adhesiveness with the silicone resin is remarkably improved, and it can be applied to both high-temperature cross-linking type and low-temperature cross-linking type silicone resins, which is preferable.
However, if the amount of the (meth) acrylic acid ester having a hydroxyl group used is 30% by weight or more, the stability of the obtained emulsion decreases, which is not preferable.

Other vinyl monomers copolymerizable with the above-mentioned (meth) acrylic acid ester having a hydroxyl group include, for example, (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, monoalkyl maleic acid. ,
Monomers containing ethylenically unsaturated carboxylic acid such as monoalkyl fumaric acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate,
Octyl (meth) acrylate, (meth) acrylic acid-2
-Ethylhexyl, lauryl (meth) acrylate, stearyl (meth) acrylate, vinyl acetate, vinyl chloride,
Vinylidene chloride, (meth) acrylonitrile, styrene, ethylene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
Triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,3-
Butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, divinylbenzene, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) ) Acrylate, glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N,
N'-methylenebis (meth) acrylamide and the like can be mentioned, and one or more of these can be used in combination.

The proportion of these other copolymerizable monomers in the copolymer is adjusted in the range from 70 to 99.5% by weight.

That is, as the undercoating agent, 3 to 15% by weight of the above-mentioned (meth) acrylic acid ester having a hydroxyl group, 2 to 20% by weight of an ethylenically unsaturated carboxylic acid, and C _{4 to} C _{10 are used.}
(Meth) acrylic acid ester having alkyl group of 40
An emulsion obtained by copolymerizing 80% by weight to 2% to 40% by weight of another monomer such as (meth) acrylonitrile is preferably used. In addition, melamine, epoxy, isocyanate, and aziridine compounds can be used as a crosslinking agent in the undercoating agent, if necessary.

The above primer emulsion can be obtained by a conventional emulsion polymerization. This polymerization reaction is carried out in an aqueous medium, and the emulsifier is contained in the range of 2 to 6% by weight based on the total amount of the monomers. If the amount of the emulsifier used is less than 2% by weight, the stability of the obtained emulsion will be insufficient and the particle size of the polymer will be large. On the other hand, if it exceeds 6% by weight, the adhesion between the undercoating agent layer and the release agent layer deteriorates.

As the emulsifier, potassium oleate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate,
Sodium dialkyl sulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl allyl ether sulfate, ammonium polyoxyethylene dialkyl sulfate, ammonium polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl allyl Anionic surfactants such as ether phosphates, polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, poly (oxyethylene-oxypropylene) block copolymers, polyethylene glycol fatty acid esters, nonionics such as polyoxyethylene sorbitan fatty acid esters A system surfactant can be illustrated. Further, as a low molecular weight polymer compound having an emulsifying and dispersing ability, for example, polyvinyl alcohol and its modified products, polyacrylamide, polyethylene glycol derivatives, neutralized products of polycarboxylic acid copolymers, casein, etc., alone or in combination with the above emulsifiers Can be used.

The monomer concentration during polymerization is 30 to 7
About 0% by weight, preferably about 40 to 60% by weight is suitable. Further, as the polymerization initiator used in the polymerization,
For example, persulfates such as ammonium persulfate, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,2
4-dimethylvaleronitrile) and other azo compounds, hydrogen peroxide, benzoyl peroxide, lauroyl peroxide and other peroxides, ammonium persulfate or combinations thereof with reducing agents such as sodium sulfite and acidic sodium sulfite. So-called redox type polymerization initiators and the like can be mentioned. The amount of the above-mentioned polymerization initiator used is preferably about 0.2 to 2% by weight, and more preferably about 0.3 to 1% by weight, based on the total amount of the monomers used for the polymerization. The polymerization reaction is usually performed at about 60 to 100 ° C. for about 2 to 8 hours.

In the present invention, the glass transition temperature of the copolymer contained in the emulsion thus obtained is also important and is -30 to + 20 ° C, preferably -20 to +10.
Copolymers having a glass transition temperature of ° C are used selectively. When the glass transition temperature becomes lower than −30 ° C.,
If the tackiness of the coating becomes too strong, while it rises above 20 ° C., the resulting coating becomes too hard and becomes impractical.

The glass transition temperature Tg of the copolymer is
In the present invention, it is estimated based on the following general formula (Equation 1).

[0030]

[Equation 1]

Where Tg is the glass transition temperature of the copolymer, (Tg) i is the glass transition temperature of the homopolymer of the i-th monomer, and (W) i is the weight fraction of the i-th monomer.

It is necessary for the undercoating agent in the present invention to contain a pigment, and by providing an undercoating agent layer containing a pigment, blocking of the undercoating agent layer is controlled,
The coating stability during coating is also improved. As the pigment contained in the undercoating agent (layer), a usual inorganic or organic pigment can be used. Specifically, for example, oxides, hydroxides, sulfides, carbonates, sulfates or silicate compounds of various metals such as magnesium, calcium, zinc, barium, titanium, aluminum, antimony and lead, polystyrene, polyethylene, Solid polymer fine powder such as polyvinyl chloride can be used. Above all, blocking can be efficiently prevented by using an inorganic pigment such as kaolin, talc, silica, gypsum, barite powder, alumina white, gloss white, satin white, titanium oxide and calcium carbonate.

The amount of the pigment is preferably adjusted in the range of 50 to 150 parts by weight with respect to 100 parts by weight of the copolymer contained in the undercoating agent. Incidentally, if the amount is less than 50 parts by weight, the tackiness of the film becomes too strong, while if it exceeds 150 parts by weight, the solvent barrier property of the film becomes insufficient and appropriate peeling performance may not be obtained.

In the undercoating agent, cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and the like, dextrin, acid-treated starch, oxidized starch, cross-linked starch, starch are added to the extent that they do not impair the desired effects of the present invention. ester,
Various water-soluble natural polymers such as starch derivatives such as graft copolymer starch; polyhydric alcohols such as ethylene glycol, glycerin, trimethylolpropane and diethylene glycol, water-soluble polyalkylene glycols such as polyethylene glycol and polypropylene glycol Plasticizers; crosslinkers such as urea / formaldehyde resins, melamine / formaldehyde resins, polyamide / polyamine / epichlorohydrin resins, polyacrylamide resins, epoxy resins; further inorganic salts; fillers; defoamers; wetting agents; leveling agents; curing Agents; thickeners; film-forming aids and the like can be added as appropriate.

Regarding the method of coating or impregnating the undercoat liquid on the release paper substrate, various devices such as an air knife coater, a roll coater, a gravure coater, a bar coater, a blade coater, a rod blade coater and a size press coater can be used. Used as appropriate. The amount of coating or impregnation is adjusted to a dry weight of about 0.1 to 20 g / m ² , preferably about 1 to 10 g / m ² . In the release paper of the present invention, the release paper substrate has a basis weight of 30 to 3
Various fiber sheets having a thickness of about 00 g / m ² and a thickness of about 30 to 300 μm are used.

The release paper comprising the release paper substrate, the undercoat layer and the release agent layer used in the pressure-sensitive adhesive sheet of the present invention thus obtained has a pigment on an emulsion having a specific monomer composition and a glass transition temperature on the substrate. Since the added undercoating agent layer is formed, curling is particularly effectively prevented, and an adhesive paper excellent in paper-passability and copyability can be constructed.

A release paper is produced by forming a release agent layer on a substrate provided with this undercoating agent layer. The release paper obtained is a release agent layer surface and chloroprene rubber (Shore A hardness 65 ± 2 °). Coefficient of dynamic friction with (JIS-P-8147)
Is preferably 0.2 or more. Incidentally, if it is less than 0.2, the effect of preventing the adhesive from adhering to the processing blade or the cutting surface becomes poor, and there is a possibility that it may cause defective running of the paper in a non-impact printer.

Specific examples of the release agent having a dynamic friction coefficient of 0.2 or more include SD-7239, BY24-162 and L manufactured by Toray Dow Corning Silicone Co., Ltd.
TC-300B, LTC-350A, LTC-350
G, LTC-370G, BY14-403, BY14-
405, BY14-407, BY14-413, BY1
4-414, BY14-411, BY14-420, KS-845, KS-770, KNS manufactured by Shin-Etsu Chemical Co., Ltd.
-202A, KNS-305, KNS-316, KNS
-319, KNS-320, X-62-A232, X-
62-1233 etc. are mentioned.

Further, the peeling force is closely related to the labeling suitability in the non-impact printer of the print heating and fixing system, and in order to obtain good peeling performance, the tensile strength of the peeling agent conforms to JIS-K-6301 method. By the way, 30
It is preferably Kg / cm ² or more. By the way, 30Kg
If it is less than / cm ² , the pressure-sensitive adhesive label may fall off in the printer, which may cause defective running of the paper or jamming. The pressure-sensitive adhesive sheet of the present invention, by combining the surface substrate obtained as described above and the release paper, suppress stacking failure due to skewed paper in the print heat fixing system, and prevent the label from falling off. It is possible to prevent the adhesive from protruding.

There is no particular limitation on the method for forming the pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive on the release agent layer of the release paper according to a conventional method and drying it if necessary. It is formed, the surface base material is attached, and the humidity is adjusted to finish.

The pressure-sensitive adhesive can be obtained by polymerizing as follows. A seed polymer mainly composed of at least one ester group-containing monomer selected from the group of (meth) acrylic acid esters is polymerized. This seed polymer has a glass transition temperature [Tg] of 215 to 303K.
Polymers having By the way, if it is less than 215K, the cohesive force tends to remarkably decrease, and if it exceeds 303K, the adhesive force tends to decrease. The seed polymer is preferably produced by a known emulsion polymerization method (for example, primary charge polymerization method, monomer addition polymerization method, pre-emulsion addition polymerization method, etc.).

The average particle size of the seed polymer is 0.15
It is 0.35 μm, preferably 0.2 to 0.3 μm.
If it is less than 0.15 μm, an emulsion having a high viscosity and poor coating suitability is formed by the second-stage emulsion polymerization (seed polymerization), and if it is larger than 0.35 μm, tackification within the particles of the copolymer is generated. The distribution of the agent becomes irregular and the adhesive performance cannot be sufficiently improved.

As the seed polymer, it is desirable that the polymerization conversion rate of the monomer is 98% by weight or more (the amount of residual monomer is less than 2% by weight). In an emulsion having a low polymerization conversion rate (a large amount of residual monomer), the reaction system may become unstable in the second-stage emulsion polymerization described above, or coarse particles in which the tackifier is aggregated may be generated. This seed polymer is a (meth) acrylate ester such as methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, -t-butyl (meth) acrylate, cyclohexyl (meth) acrylate,
2-Ethylhexyl (meth) acrylate, Isononyl (meth) acrylate, Lauryl (meth) acrylate,
Main component is at least one selected from stearyl (meth) acrylate, ethylene, vinyl chloride, vinylidene chloride, ethylenically unsaturated carboxylic acid, crosslinkable monomer, (α-methyl) styrene, N-alkyl (meth) acrylamide. Copolymers of at least one copolymerizable monomer selected from, (meth) acrylonitrile are preferred. Examples of the ethylenically unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride, monoalkyl maleates having an alkyl group having 1 to 12 carbon atoms, and hydroxyethyl (propyl) monomerate. , Phthalic acid, monoalkyl (carbon number 1 to 12) esters of itaconic acid, and the like. Examples of the crosslinkable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxyethyl (meth) acrylate, polyethylene glycol or polypropylene glycol mono ( Hydroxyl group-containing monomer such as (meth) acrylate, epoxy group-containing monomer such as glycidyl (meth) acrylate, -CONH such as (meth) acrylamide, diacetone acrylamide
Examples include monomers having _two or methylol groups, divinylbenzene, divinylsilane, diallylphthalate, cyclopentadiene, methylenebisacrylamide, diallylmaleate, tetraallyloxyethane, and other monomers having two or more ethylenically unsaturated bonds. it can.

As the pressure-sensitive adhesive of the present invention, a copolymer obtained by continuously applying the emulsion polymerization of the second stage by applying the emulsion of the copolymer produced by the emulsion polymerization of the first stage is used. Here, in the second-stage emulsion polymerization, the number of carbon atoms is 4-18.
Of (meth) acrylic acid alkyl ester having an alkyl group of, and at least one of functional group-containing monomer selected from ethylenically unsaturated carboxylic acid and crosslinkable monomer, or further vinyl ester, carbon number The emulsified monomer mixture obtained by adding a tackifier to at least one nonionic monomer selected from (meth) acrylates having 1 to 3 alkyl groups, (α-methyl) styrene and benzyl (meth) acrylate is added to the above. It is polymerized by adding it to the first stage seed polymer.

Examples of the tackifier used in the present invention include rosin resins such as raw rosin, hydrogenated rosin, hydrogenated rosin ester, disproportionated rosin ester and polymerized rosin ester, α-pinene resin, β- Pinene resin, dipentene-based resin, polyterpene-based resin such as terpene-phenol resin, Hiletz (Mitsui Petrochemical), Quinton (Nippon Zeon), Takkyroll (Sumitomo Chemical), Estecorets 1000 (Esso Chemical), etc. Aliphatic petroleum resin,
Aromatic petroleum resins such as Neopolymer S (Nippon Synthetic Resin), Petrosin (Mitsui Petrochemical), Petrite (Toyo Soda), Hiresin (Toho Petrochemical), Tac Ace (Mitsui Petrochemical), Esteco Pure monomer copolymerized petroleum resin such as Let's 200 (manufactured by Esso Chemical), alicyclic petroleum resin such as Alcon (manufactured by Arakawa Chemical), Estekollets (manufactured by Esso Chemical), polyamide based such as Tomeide (manufactured by Fuji Kasei) Epoxy resins such as resin, Epicoat (manufactured by Shell Chemical), Epomic (manufactured by Mitsui Petrochemical Epoxy), Epototo (manufactured by Toto Kasei), natural rubber, isoprene rubber,
Examples thereof include elastomers such as styrene-butadiene rubber, styrene-butadiene block copolymer, styrene-isoprene block copolymer, ethylene-isoprene-styrene block copolymer.

The pressure-sensitive adhesive of the present invention comprises the second stage polymer 300 and the first stage seed polymer 100 parts by weight.
A mixture of up to 3,000 parts by weight is used. Incidentally, when the amount is less than 300 parts by weight, no improvement in adhesive strength is observed, while when it exceeds 3,000 parts by weight, the emulsion polymerization stability and the stability of the produced emulsion are deteriorated, which is not preferable.

The adhesive forming the adhesive layer has a tensile strength (JIS-K-6301) of 0.5 to 2.0 kg.
/ Cm ² , and the elongation rate (JIS-K-6301) is 1,
It is preferably 500 to 3,000% because the adhesion of the adhesive to the cutting blade and the cut surface is further controlled when the adhesive sheet is cut into sheets.

[0048]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
In addition, "part" and "%" in an example respectively show "weight part" and "weight%" unless there is particular notice.

Example 1 [Surface substrate] Bleached softwood kraft pulp (NBKP) 30
Parts and 70 parts of bleached hardwood kraft pulp (LBKP) were added to a pulp mixture containing 1.3% of a sizing agent and 5% of a filler for each pulp to prepare a stock, and then rice was produced using a Fourdrinier machine. A high-quality paper having a basis weight of 64 g / m ² was made. The papermaking conditions at this time were a machine speed of 600 m / min, a pulp slurry outflow speed (jet speed: J) and a wire speed (W) ratio (J / W) of 1.015. Then, a paper having a machine take-up width of 3200 mm after papermaking was obtained. Next, in order to measure the transmitted microwave intensity of this paper, 38
It was cut into 8 sections with a width of 1 mm (Sample Nos. 1, No. 2, ... No. 8 were attached from the operating side of the paper machine). The eight types of samples cut in this way were measured for angular dependence of the intensity of transmitted microwaves with a molecular orientation meter (MOA-2001A) manufactured by Kanzaki Paper Co., Ltd., and the results are shown in Table 1. Further, the above high-quality paper having a width of 3200 mm was half-cut into a width of 1600 mm to obtain a base paper for a surface base material and a base paper for a release paper substrate.

[Release Paper] 2-Hydroxyethyl Methacrylate 20 g, Butyl Acrylate 240 g, Acrylonitrile 40 g, Acrylic Acid 20 g, Methyl Methacrylate 68 g, N-Methylolacrylamide 12 g, Alkyl Phenyl Ether Sulfate Emulsifier (manufactured by Sanyo Kasei Co., Ltd.) , Trade name "Eleminol ES-70") and ion-exchanged water 170 g to prepare an emulsified monomer mixed liquid (A).

Next, in a 2-liter four-necked flask equipped with a stirrer, a cooler, a dropping funnel, a nitrogen suction tube, and a thermometer, 240 g of ion-exchanged water and the same emulsifier 2 as above were used.
g and 0.8 g of potassium persulfate were charged, the temperature was raised to 70 ° C. while substituting with nitrogen, and then 1/6 of the emulsified monomer mixture liquid (A) was added dropwise. When the reaction rate reached 90%, the remaining emulsified monomer mixture liquid (A) was added dropwise over 2 hours for polymerization. After completion of dropping, the reaction was completed by aging at 70 ° C. for 2 hours. After completion of aging, the contents of the flask are placed at 40 ° C.
After cooling to room temperature, an aqueous sodium hydroxide solution was added to carry out a neutralization reaction, and after completion of the reaction, vigorous stirring was carried out to obtain an aqueous copolymer (a) used in the present invention. The glass transition temperature of the obtained copolymer is 4 ° C. The amount of emulsifier is 3.0%.

100 parts of the aqueous copolymer (a), 100 parts of wet heavy calcium carbonate (manufactured by Bihoku Co., Ltd., trade name "Hydrocurve K-9"), lubricant (manufactured by San Nopco,
1 part of product name "Nopcoat C-104", 0.6 part of antifoaming agent (manufactured by San Nopco Ltd., product name "Nopco 1407K"), a 45% concentration undercoat layer coating solution was prepared, and the above base paper for release paper substrate And dry weight of 5g / m with rod blade coater
^It was coated so as to be ^2, and dried to obtain a release paper substrate.

On the surface of the release paper substrate, a 9% toluene solution of a silicone release agent (trade name "KS-845" manufactured by Shin-Etsu Chemical Co., Ltd., dynamic friction coefficient 0.27, tensile strength 32 Kg / cm ² ) was dry coated. It was coated with a bar coater so that the amount of work was 1.0 g / m ^2, and dried to obtain release paper.

[Adhesive] First, a seed emulsion was prepared as follows. Vinyl acetate 30 parts, acrylic acid-
A monomer mixture of 68 parts of 2-ethylhexyl, 2 parts of acrylic acid and 0.3 part of N-methylol acrylamide was mixed with 1 part of sodium polyoxyethylene alkylphenyl ether sulfate, 1 part of sodium dodecylbenzenesulfonate.
2 parts, polyoxyethylene nonyl phenyl ether (H
LB (about 10) 1 part, sodium acetate 0.3 part, and ion-exchanged water 30 parts were added into an emulsifier aqueous solution and stirred to form a pre-emulsion.

In a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube, sodium dodecylbenzenesulfonate 0.2 was added.
Parts, polyoxyethylene nonyl phenyl ether (HL
B about 10) 1 part, sodium acetate 0.3 part, ion-exchanged water 30 parts of an emulsifier aqueous solution was charged, and the temperature of the liquid was raised to 75 ° C. while stirring with nitrogen gas, to obtain 5/100 of the pre-emulsion. Addition is carried out for 30 minutes for initial polymerization, and then the remaining amount is added dropwise over 4 hours at 75-80 ° C.
Polymerization was carried out while holding at. After completion of the dropping, the temperature was further maintained at 80 ° C. to carry out a late polymerization to obtain a seed emulsion. The seed emulsion obtained here has a solid content concentration of 50%,
Viscosity 100 cps, pH 3.0, average particle size 0.23μ
m, the glass transition temperature of the copolymer was -44 ° C.

Next, a copolymer emulsion containing a tackifier was prepared as follows. Monomer mixture of 30 parts of methyl acrylate, 58 parts of 2-ethylhexyl acrylate and 2 parts of acrylic acid (copolymer glass transition temperature is -45 ° C), tackifier (Arakawa Chemical Co., Ltd., trade name "Resin Super Ester A" -100 ") 10 parts of a mixed solution, 1 part of sodium polyoxyethylene alkylphenyl ether sulfate, 0.3 part of sodium dodecylbenzenesulfonate, 1 part of polyoxyethylene nonylphenyl ether (HLB about 10), and sodium acetate of 0. 4 copies,
30 parts of ion-exchanged water was added to an emulsifier aqueous solution and stirred to form a pre-emulsion.

Further, 20 parts of the seed emulsion and 18 parts of ion-exchanged water were charged into a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube, and the liquid temperature was raised to 75 ° C. while passing nitrogen gas while stirring. Hold and Pre-emulsion 1
32.7 parts, potassium persulfate 0.3 parts, ion-exchanged water 7
Part of the solution was added dropwise over 4 hours to carry out polymerization. The obtained copolymer emulsion has a solid content concentration of 65%, a viscosity of 400 cps, a pH of 3.5, and an average particle size of 0.45 μm.
Met. Then, this copolymer emulsion was neutralized with ammonia water (concentration 25%), and then a thickener (manufactured by Kao Corporation, trade name "Bissurf 1400") was added to adjust the viscosity to 5,000 cps to obtain an adhesive. It was

[Adhesive Sheet] The release agent layer surface of the release paper was coated with the above adhesive (tensile strength of 2.0 kg / cm ² / elongation of 1,500%) on a reverse roll coater to a dry coating amount of 17 g / m 2. ^The coating was applied so that it would be ^2, and then dried. Then, the surface base material was overlaid on the surface of the pressure-sensitive adhesive layer and bonded with a press roll to obtain a pressure-sensitive adhesive sheet.

On the other hand, the pressure-sensitive adhesive sheet thus obtained was cut into 4 sections with a width of 381 mm (No. 1, No. 2, ... No. 4 were sequentially marked from one end). Next, each of the 381 mm wide long paper samples is subjected to marginal punching, perforated at every 280 mm in the length direction (paper making direction), and folded at that portion (creased by a foam printing machine). , 381 mm x 280 mm (continuous) conversion approximately 100
Prepare a folded paper sample with a height of mm (equivalent to about 1000 sheets) and use a non-impact printer (trade name: MEL
Paper was passed through COM8270 / manufactured by Mitsubishi Electric Corp., and the tilt angle was measured. The obtained results are shown in Table 2.

[0060]

[Table 1]

[0061]

[Table 2]

In Table 1 and Table 2 above, R
Is the ratio of the maximum and minimum values of the transmitted microwave intensity, and the measurement by the molecular orientation meter consists of a cavity resonator system composed of a rectangular waveguide provided with a sample insertion part. The sheet sample surface was irradiated with microwave polarized waves in the vertical direction, the sheet was rotated around the normal axis of the sheet surface, and the transmitted microwave intensities at 360 points were detected and plotted every 1 degree.

Example 2 [Surface substrate] The same surface substrate as in Example 1 was prepared.

[Release Paper] The aqueous copolymer (a) used in Example 1 was manufactured by Chuo Rika Co., Ltd. under the trade name of “Ricabond ET-8”.
4 ”: (glass transition temperature −11 ° C.) and the coating dry weight of the undercoating agent was changed to 4.5 g / m ² Example 1
A release paper substrate was obtained in the same manner as in. The silicone release agent manufactured by Toray Dow Corning Silicone Co., Ltd. under the trade name "B
Y24-162 "(Dynamic friction coefficient 0.32 / tensile strength 4
0 kg / cm ²⁾ and then, except that the dry coating amount was 1.1 g / m ² was release paper in the same manner as in Example 1. A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that this release paper was used.

Example 3 To a pulp blend consisting of 10 parts of bleached softwood kraft pulp (NBKP) and 90 parts of bleached hardwood kraft pulp (LBKP), 1.5% of sizing agent and 8% of filler per pulp were added, respectively. After the material was prepared, a fine paper of 60 g / m ² was produced using a Fourdrinier machine. The papermaking conditions at this time were a machine speed of 590 m / min and a J / W ratio of 1.010.
Met. And the machine width after papermaking is 3200mm
Got the paper. Next, in the same manner as in Example 1, the angle dependence of the transmitted microwave intensity of each paper sample was measured. The results obtained are shown in Table 3.

Further, the above high-quality paper was half-cut to a width of 1600 mm to prepare a base paper for a surface base material and a base paper for a release paper substrate, a pressure-sensitive adhesive sheet was produced in the same manner as in Example 1, and the obtained pressure-sensitive adhesive sheet was passed. The suitability was evaluated and the results are shown in Table 4.

[0067]

[Table 3]

[0068]

[Table 4]

Example 4 [Surface substrate] 240 ml of freeness using newsprint as a raw material
Regenerated pulp of (CSF) was beaten with a double disc refiner to obtain a freeness of 100 ml (CSF).
10 parts of this recycled pulp and 500m freeness
70 parts of LBKP and NBKP beaten to be 1
To the pulp slurry obtained by blending 20 parts, talc was added so that the paper ash content was 6%, and rosin size was added as a sizing agent to 1.4% of the dry pulp. / M ² of base paper was produced. The machine conditions at this time were a machine speed of 400 m / min and a J / W ratio of 1.020. After the papermaking, a high quality paper having a take width of 1600 mm was obtained. Next, this paper was cut into four sections with a width of 381 mm in the width direction, and the angle dependence of the intensity of transmitted microwaves was measured in the same manner as in Example 1, and the results are shown in Table 5.

[0070]

[Table 5]

[Release Paper] A release paper substrate was obtained in the same manner as in Example 1. Then, the silicone release agent was made by Toray Dow Corning Silicone Co., Ltd .: trade name "LTC-350A" (dynamic friction coefficient 0.21 / tensile strength 18 kg / cm ² ),
Same as Example 1 except that the dry coating amount was 1.0 g / m ² .

[Adhesive Sheet] Acrylic adhesive (manufactured by Kanebo NSC, trade name “Durotac AQ-432T”, tensile strength 1.5 kg / c on the release agent layer surface of the release paper.
m ² / elongation rate of 2,500%) was applied with a slot die coater so that the dry coating amount was 14 g / m ² and dried. Then, the surface base material was overlaid on the surface of the pressure-sensitive adhesive layer and bonded with a press roll to obtain a pressure-sensitive adhesive sheet.

Using this pressure-sensitive adhesive sheet, suitability for passing through a printer was evaluated, and the obtained results are shown in Table 6.

[0074]

[Table 6]

Comparative Example 1 A pulp slurry consisting of 28 parts of bleached softwood kraft pulp (NBKP) and 72 parts of bleached hardwood kraft pulp (LBKP) was added with 0.8% sizing agent and 7% filler per pulp. After the material was prepared, a fine-grained paper of 64 g / m ² was produced using a Fourdrinier machine. The papermaking conditions at this time were a papermaking speed of 600 m / min and a J / W ratio of 1.025. Then, a base paper having a machine take-up width of 3200 mm was obtained after the papermaking. Next, this paper was cut in the same manner as in Example 1 and the angle dependence of the intensity of transmitted microwaves was measured. The obtained results are shown in Table 7.

A pressure-sensitive adhesive sheet was manufactured in the same manner as in Example 1 using the above-mentioned base paper, and a non-impact printer (trade name: MELCOM82) was manufactured using this pressure-sensitive adhesive sheet.
70 / Mitsubishi Electric Co., Ltd.) Paper passing suitability was evaluated. The results obtained at that time are shown in Table 8.

[0077]

[Table 7]

[0078]

[Table 8]

Example 5 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the high-quality paper of Comparative Example 1 having a basis weight of 64 g / m ² was used as the surface substrate, and the non-impact printer paper-passability was evaluated. evaluated.
The results obtained at that time are shown in Table 9.

[0080]

[Table 9]

Example 6 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the high-quality paper of Comparative Example 1 having a basis weight of 64 g / m ² was used as the release paper substrate, and the non-impact printer paper-passability was evaluated. evaluated. The results obtained at that time are shown in Table 10.

[0082]

[Table 10]

Example 7 In the same manner as in Example 2, a surface base material and a base paper for a release paper substrate were obtained. Further, a release paper substrate was obtained in the same manner as in Example 2. Then, a silicone release agent manufactured by Toray Dow Corning Co., Ltd., trade name "SD-7239" (dynamic friction coefficient 0.25 /
Tensile strength of 23 kg / cm ² ) and dry coating amount of 1.0
A release paper was obtained in the same manner as in Example 2 except that the release paper was set to g / m ² .

[Adhesive Sheet] In Example 1, the tackifier was manufactured by Yasuhara Yushi Co., Ltd. under the trade name “YS Resin TO-10”.
A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that "5" was used.
Above release paper and above adhesive (tensile strength 1.8kg / c
m ² / elongation of 2,500%) is coated with a reverse roll coater so that the dry coating amount is 15 g / m ^2, and dried, and the above-mentioned surface base material is overlaid on the pressure-sensitive adhesive layer surface with a press roll. It stuck together and obtained the adhesive sheet.

Example 8 A surface base material and a base paper for a release paper substrate were obtained in the same manner as in Example 1. [Release Paper] A release paper substrate was obtained in the same manner as in Example 2 using the above base paper. Next, the silicone release agent was manufactured by Toray Dow Corning Co., Ltd. under the trade name of "LTC-350A" (dynamic friction coefficient 0.21 / tensile strength 18 kg / cm ² ), and the dry coating amount was 1.0 g / m ^2. The same procedure as in Example 2 was carried out except that coating and drying were performed.

[Adhesive Sheet] An acrylic adhesive (Kurobo NSC Co., trade name “Durotac AQ-432T” (tensile strength 1.5 kg /
(cm ² / elongation of 2,500%) was applied and dried with a slot die coater so that the dry coating amount was 14 g / m ² . Then, the surface base material was overlaid on the surface of the pressure-sensitive adhesive layer and bonded with a press roll to obtain a pressure-sensitive adhesive sheet.

Comparative Example 2 In Example 2, an acrylic pressure-sensitive adhesive (trade name "Acronal YJ8655-DB" manufactured by Mitsubishi Yuka Birdiche Co., Ltd. (tensile strength 2.1 kg / c) was applied to the release agent layer surface of the release paper.
m ² and elongation 3,200%) were coated with a reverse roll coater so that the dry coating amount was 20 g / m ² and dried. Next, the same surface base material as in Example 2 was placed on the surface of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive sheet was bonded to the pressure-sensitive adhesive sheet by a press roll.

The 10 types of pressure-sensitive adhesive sheets thus obtained were evaluated as follows, and the results are shown in Table 11.

[Adhesive strength] The adhesive strength of the surface of the pressure-sensitive adhesive to the stainless steel plate is 20 in accordance with JIS-Z-1528.
2k adhesive sheet on stainless steel plate at room temperature of 60 RH
When the tape was peeled off at an angle of 180 ° with an Instron type tensile tester at a pulling speed of 300 mm / min, the load (g / 25)
mm) is measured.

[Cutability] A pressure-sensitive adhesive sheet having a length of 20 cm:
The width is 15 cm, 100 sheets are piled up, and after cutting continuously 20 times in the width direction with a guillotine tester (Rokugo Seisakusho, trade name "CM-450"), the amount of the adhesive attached to the guillotine blade (mg) Was measured.

[0091]

[Table 11]

[0092]

As is apparent from Tables 2, 4, 6, 8, 10, and 11, the pressure-sensitive adhesive sheets obtained in the examples of the present invention were used in the printing heat fixing type non-impact printer. The pressure-sensitive adhesive sheet was excellent in sheet-passing suitability in a recording device, in which no inclination occurred, and the protrusion of the pressure-sensitive adhesive in guillotine cutting was suppressed.

[Brief description of drawings]

FIG. 1 is an example showing a measurement result of a mechanical paper by a molecular orientation meter.

FIG. 2 is an example of measurement by a molecular orientation meter of high-quality paper according to the present invention.

FIG. 3 shows the definition of oblique tilt angle.

[Explanation of symbols]

 A: Machine direction B: Fiber main axis C: Transmitted microwave intensity D: Orientation angle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 27/20 A 8413-4F 27/28 101 8413-4F C09J 7/02 7/04 D21H 19 / 20 G09F 3/10 A 7323-5G C 7323-5G

Claims (5)

[Claims] 1. A pressure-sensitive adhesive sheet comprising a surface base material, a pressure-sensitive adhesive, a release agent, an undercoating agent, and a release paper substrate laminated together, and the surface base material and / or the release paper substrate is measured by a microwave measuring instrument. The ratio of the maximum value and the minimum value of the transmitted microwave intensity is 1.0 to 1.3, and the main component of the primer is
A copolymer and a pigment obtained by emulsion-copolymerizing at least one kind of (meth) acrylic acid ester having a hydroxyl group in the molecule and at least one kind of other vinyl-based monomer copolymerizable therewith. Adhesive sheet to be. 2. The adhesive has an average particle size of 0.15 to 0.15.
To an emulsion of 100 parts by weight of a seed polymer having 0.35 μm (meth) acrylic acid ester as a main component,
300 to 3,000 parts by weight (in terms of solid content) of a pre-emulsion composed of a monomer mixture containing a (meth) acrylic acid ester as a main component, a tackifier, an emulsifier, and water.
The pressure-sensitive adhesive sheet according to claim 1, which is a pressure-sensitive adhesive obtained by sequentially adding and emulsion-copolymerizing. 3. The adhesive has a tensile strength of 0.5 to 2.0 kg /
The pressure-sensitive adhesive sheet according to claim 1 or ² , having a cm ² and an elongation of 1,500 to 3,000%. 4. A dynamic friction coefficient (JIS-P-814) with a chloroprene rubber having a Shore A hardness of 65 ± 2 ° on the surface of a release agent.
The pressure-sensitive adhesive sheet according to claim 1, wherein 7) is 0.2 or more. 5. The pressure-sensitive adhesive sheet according to claim 1, wherein the release agent has a tensile strength of 30 kg / cm ² or more.