JP2009121011A - Coated paper for pressure-sensitive adhesive sheet, pressure-bonded product using the same, and method for producing pressure-processed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive coated paper having a high blank glossiness, which is used in a post-glue method having printing / printing suitability in each method (offset, ink jet, electrophotography), and pressure bonding using the same. Products and methods for making crimped products.
An adhesive layer is provided on at least one surface of a coated paper after printing, and the adhesive layers can be bonded to each other by high pressure treatment, and can be peeled between the adhesive layers after bonding by a post-glue pressure bonding method. The coated paper has a base paper and at least one coating layer formed on at least one surface thereof and containing a pigment and a binder resin as main components. The coated paper has a surface smoothness of 1000 to 5000 seconds, an air permeability of 2000 to 10,000 seconds, a glossiness of 50% or more, a paper surface pH of 4.0 to 9.0, and a paper moisture content of 3 to 7 %.
[Selection figure] None

Description

  The present invention relates to a coated paper for a pressure-sensitive adhesive sheet, a crimped product using the same, and a method for producing a crimped product. Specifically, it is a post-glue method used in various postcard systems such as tri-fold or bi-fold postcards that have offset printability, inkjet recording properties, and electrophotographic printability, and further provided with an adhesive layer on the coated paper. The present invention relates to a pressure-sensitive adhesive sheet coated paper that can be used, a crimped article using the same, and a method for producing a crimped article.

  Along with the revision of the Postal Law, a postcard system having a confidential property by folding a sheet on which necessary information is recorded into two or three is put into practical use and has become widespread. The adhesive layer provided on the base sheet of the postcard having such confidentiality is not adhesive at room temperature and normal pressure, and exhibits adhesiveness by pressing the adhesive layers facing each other, and After bonding, a pressure-sensitive adhesive sheet having an adhesive layer that can be re-peeled (hereinafter also referred to as “confidential postcard paper” as a representative example) is used.

  There are two types of systems for creating confidential postcards, the first paste method and the second paste method. As described in Japanese Patent Application Laid-Open No. 7-276858 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2006-2023 (Patent Document 2), the leading adhesive method has an adhesive layer on the surface of a paper substrate. After printing on the existing pressure-sensitive adhesive sheet, it is crimped to make a confidential postcard. That is, since an adhesive layer (glue) is applied to the surface of the coated paper before printing, it is called “tip glue”. The main feature of the confidential postcards produced by the pre-glue method is that a silica-based pigment and a natural rubber-based adhesive are mainly used for the adhesive layer, so that the printed surface after peeling is mat-based.

  On the other hand, as described in Japanese Patent Application Laid-Open No. 2002-285106 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2006-207076 (Patent Document 4), an adhesive layer is applied after printing on coated paper. It is called “post glue” because it is processed into a postcard. The main feature of confidential postcards made with the post-glue method is the use of clear varnish for the adhesive layer, so the glossy surface of the coated paper is reflected and the printed surface after peeling is selected from matte to glossy. In recent years, the frequency of use has increased.

  On the other hand, in recent years, colorization, high speed, and high image quality of printers of various systems such as electrophotography and inkjet have been advanced. In particular, in the field of on-demand publications, it is relatively easy to handle variable information even with a small number of copies from one copy unit. Especially, the variable information section (individual addresses, items preferred by customers) The tendency to produce printed matter that has been produced by conventional printing methods with printers of various methods has become prominent.

Currently, coated paper used in the preparation of such post-glue confidential postcards is usually in the field of commercial printing (offset printing) as described in JP-A-6-158597 (Patent Document 5). It has been common to use what has been used. The coated paper is usually produced by applying a pigment having an average particle diameter of 2 μm or less using a various coater to 10 g / m ² or more per side of the base paper, and then smoothing the surface by calendering.

  Therefore, since these general coated papers are mainly intended for offset printing, on the other hand, the ink absorbency in the ink jet system is extremely low, and ink stains due to bleeding or poor drying occur and are difficult to use. is there. Further, even when printing with electrophotography, since the air permeability of the coated paper is high, blisters are generated in the toner image at the time of heat-fixing, which may be difficult to use.

  At present, there is no coated paper for pressure-sensitive adhesive sheets that is compatible with each printing / printing method (offset, inkjet, electrophotography) and has a high white paper gloss in the production of a postcard-type confidential postcard.

  However, the inkjet recording method used here is not a method that can print photographic images etc. in full color as used in general homes, but mono-color printing for addressing and simple information printing etc. Is the main. For this reason, even if the ink absorptivity required for coated paper in this application is lower than that of coated paper as described in JP-A No. 2005-161723 (Patent Document 6), ink stains due to occurrence of bleeding or poor drying It can be used without generating.

Japanese Patent Laid-Open No. 7-276858 (second term) JP 2006-2023 A (1st term) JP 2002-285106 A (first item) JP 2006-207076 A (First Item) Japanese Patent Laid-Open No. 6-158597 (Section 1) Japanese Patent Laying-Open No. 2005-161723 (first item)

  The object of the present invention is to create a confidential postcard having printing / printing suitability in each system (offset, ink jet, electrophotography), stable peelability in the post-glue system, and a high blank paper gloss. The present invention provides a coated paper for a pressure-sensitive adhesive sheet, a crimped article using the same, and a method for producing a crimped article.

  The present invention includes the following modes.

(1) The pressure-sensitive adhesive sheet coated paper according to the present invention is provided with an adhesive layer on at least one surface of the coated paper after printing, and the adhesive layers can be bonded to each other by high pressure treatment. It is used as a pressure-bonded postcard paper in a post-glue pressure bonding method that can be peeled later between adhesive layers, and the coated paper is formed on a base paper and at least one surface thereof, and is mainly composed of a pigment and a binder resin. The coated paper has a surface smoothness of 1000 to 5000 seconds, an air permeability of 2000 to 10,000 seconds, a glossiness of 50% or more, and a paper surface pH of 4. 0 to 9.0 and the moisture content of the sheet is 3 to 7%.
(2) The coated paper for a pressure-sensitive adhesive sheet according to (1), wherein the Cobb water absorption at 20 seconds of the coated paper is 15 to 80 g / m ² .
(3) The coated paper for pressure-sensitive adhesive sheets according to (1) to (2), wherein the organic fine particle pigment is contained in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the total pigment in the outermost coating layer.
(4) The coated paper for a pressure-sensitive adhesive sheet according to (3), wherein the organic fine particle pigment is a hollow plastic pigment having a hollow structure with a hollow ratio of 30 to 80%.

(5) The pressure-bonded product according to the present invention is provided with an adhesive layer on at least one surface of the coated paper described in (1) to (4), and the adhesive layers are subjected to pressure-bonding. Further, it is characterized by being subjected to a high pressure treatment with a metal mirror surface roll.
(6) The crimped article according to (5), wherein the glossiness of the adhesive layer surface after peeling between the adhesive layers is 55% or more.

(7) In the method for producing a crimped product according to the present invention, an adhesive layer is provided on at least one surface of the coated paper described in (1) to (4), and the adhesive layer is subjected to the crimping process. And a high pressure treatment with a metal mirror roll.
(8) The method for producing a crimped product according to (7), wherein a surface temperature of the metal mirror surface roll is 15 to 80 ° C.

  According to the present invention, it is possible to create a confidential postcard having printing / printing suitability in each method (offset, ink jet, electrophotography), stable peeling property by a post-glue method, and having a high white paper gloss. A coated paper for a pressure-bonding sheet and a crimped product using the same are obtained.

The present invention will be described in detail below.
The pressure-sensitive adhesive sheet coated paper according to the present invention has a base paper and at least one coated layer formed on at least one surface thereof and containing a pigment and a binder resin as main components, The surface smoothness, air permeability, glossiness, and paper surface pH of the coated paper are within specific ranges.

  The smoothness of the coated paper surface is 1000 to 5000 seconds, preferably 2000 to 5000. When the smoothness is lower than 1000 seconds, when the adhesive layer is applied, a sufficient adhesion area cannot be ensured at the adhesion interface, and the adhesive strength is reduced, which may make it difficult to use as a confidential postcard. . On the other hand, when the smoothness is higher than 5000 seconds, when ink jet printing is performed, the ink absorbability is extremely deteriorated, resulting in ink bleeding and poor drying, and a satisfactory printed matter may not be obtained.

  The air permeability of the coated paper is 2000 to 10,000 seconds, preferably 4000 to 10,000. When the air permeability is lower than 2000 seconds, when the adhesive layer is applied and adhered, the adhesive may permeate into the coated paper base material and may not exhibit sufficient adhesive force. Further, when the air permeability exceeds 10,000 seconds, the ink absorbability when printing by the ink jet method may be deteriorated.

  The glossiness of the coated paper is 50% or more, preferably 60% or more. When the gloss level is lower than 50%, it becomes a matte coated surface and does not become a glossy glossy coated surface, even after being subjected to a high pressure treatment at the time of pressure bonding, after peeling between the adhesive layers, It is difficult to make the adhesive layer surface 55% or more, which is a glossiness with glossiness.

  The paper surface pH of the coated paper surface is 4.0 to 9.0, preferably 6.0 to 9.0. When the pH of the paper surface is higher than 9.0, when the adhesive layer is applied, the alkali ion component or water-soluble salt present in the coated layer of the coated paper base material affects the adhesive layer and adheres. Since the strength is increased, the coated paper base material is destroyed at the time of peeling, and it may be difficult to use it as a confidential postcard. On the other hand, when the pH is lower than 4.0, there is a problem in terms of durability due to remarkable deterioration of the paper, or yellowing may occur over time. In order to achieve pH 4.0 to 9.0, chemicals such as pigments, binder resins and auxiliaries used in the coating layer are selected, and into the coating layer of impurities such as alkali metals derived from raw material chemicals. It is an effective means to avoid contamination.

Preferably Cobb water absorption of coated paper (JIS-P8140 described) is 15 to 80 g / ^{m 2} at 20 seconds, more preferably from 15 to 60 g / ^{m 2.} When the Cobb absorbency is less than 15 g / m ² , when ink-jet printing is performed, the ink absorbability deteriorates and ink bleeding or drying failure may occur, and a satisfactory printed matter may not be obtained. Moreover, when the Cobb absorbency is more than 80 g / m ² , the adhesive may permeate and sufficient adhesive strength may not be exhibited.

  About the pulp which comprises a base paper, there is no limitation in particular in the manufacturing method and kind. For example, chemical pulp such as KP, mechanical pulp such as SGP, RGP, BCTMP and CTMP, waste paper pulp such as deinked pulp, and non-wood pulp such as kenaf, bamboo, straw, hemp, etc. In addition, organic synthetic fibers such as polyamide fibers and polyester fibers, regenerated fibers such as rayon fibers and polynosic fibers, and inorganic fibers such as glass fibers, ceramic fibers, and carbon fibers can be mixed. In addition, it is preferable to use the pulp bleached without using chlorine, such as ECF pulp and TCF pulp, as the pulp used for the base paper.

  In addition, a filler may be blended in the base paper as necessary. As the filler, various pigments generally used for fine paper can be used, such as kaolin, calcined kaolin, calcium carbonate, calcium sulfate, barium sulfate, titanium dioxide, talc, zinc oxide, alumina, magnesium carbonate, magnesium oxide, Mineral pigments such as silica, white carbon, bentonite, zeolite, sericite and smectite, as well as fine hollow particles, solid particles and polystyrene resins, urea resins, melamine resins, acrylic resins and vinylidene chloride resins Examples thereof include organic pigments such as through-hole particles.

  In addition to the pulp fiber and filler, various anionic, nonionic, and cationic properties that have been used in the past are included in the stock when the base paper is made, as long as the desired effects of the present invention are not impaired. Alternatively, various additive agents for papermaking, such as amphoteric yield improvers, freeness improvers and internal sizing agents, can be appropriately selected and used as necessary. Furthermore, internal additives for papermaking such as dyes, fluorescent brighteners, pH adjusters, antifoaming agents, pitch control agents, slime control agents and the like can be added as necessary.

  There is no particular limitation on the paper making method of the base paper. For example, an acidic paper making method in which the paper making pH is around 4.5, an alkaline filler such as calcium carbonate is contained as a main component, and the paper making pH is from about 6 to about the paper making pH. All paper making methods such as the neutral paper making method with 9 weak alkalinity can be applied, and the paper machine also uses the long net paper machine, twin wire paper machine, round net paper machine, Yankee paper machine etc. as appropriate be able to.

  Examples of the coating layer pigment for coated paper include heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, structural kaolin, delaminated kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, and alumina. , Magnesium carbonate, magnesium oxide, silica, magnesium aluminosilicate, particulate calcium silicate, particulate magnesium carbonate, particulate light calcium carbonate, white carbon, satin white, bentonite, zeolite, sericite, smectite, etc. And polystyrene resin, styrene-acrylic copolymer resin, urea resin, melamine resin, acrylic resin, vinylidene chloride resin, benzoguanamine resin, and organic pigments made of these fine hollow particles and through-hole type organic materials. That. In the present invention, heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, structural kaolin, fine light calcium carbonate, white carbon, and satin white are preferably used, and one or more of these pigments are used. Combinations can be used as appropriate. In the present invention, it is effective to select neutral to acidic pigments such as kaolin, clay, silica, and titanium oxide in order to achieve pH 4.0 to 9.0. It is preferable to select from Amazon, manufactured by CADAM), calcined kaolin, and the like, since there are few impurities such as water-soluble salts and alkali ion components can be reduced.

  Here, an organic fine particle pigment is preferably blended in the outermost coating layer. It is preferable that the compounding quantity of an organic fine particle pigment is 1-50 mass parts in 100 mass parts of all the pigments. When the content is less than 1 part by mass, the gloss expression after the high pressure treatment at the time of pressure bonding may be insufficient. Moreover, when more than 50 mass parts, in order to maintain the coating-film intensity | strength of a coating layer, manufacturing cost becomes high by the increase in the amount of binders, etc.

  The organic fine particle pigment is preferably a hollow plastic pigment having a hollow structure and a hollow ratio of 30 to 80%. When the hollow ratio is lower than 30%, the gloss development effect after the high pressure treatment at the time of pressure bonding may be insufficient. On the other hand, when the hollow ratio exceeds 80%, the effect of developing the gloss after the high pressure treatment at the time of pressure bonding is saturated, and the production cost is increased, which is not preferable.

  The composition of the hollow organic fine particle pigment is not particularly limited, and examples thereof include styrene, ethylene, vinyl chloride, polyurethane, acrylic, vinyl acetate, polycarbonate, nylon, and copolymers thereof. Of these, styrene or a styrene-acrylic copolymer is preferable. The average particle size of the hollow plastic pigment is preferably 5 μm or less. If it exceeds 5 μm, the gloss development effect after the high pressure treatment at the time of pressure bonding may be insufficient. The resin used for the hollow plastic pigment preferably has a glass transition temperature (Tg) in the range of 50 to 120 ° C. When Tg is less than 50 ° C. or exceeds 120 ° C., the gloss development effect after the high pressure treatment at the time of pressure bonding may be insufficient. Specific examples of the hollow plastic pigment used in the present invention include AE851 (hollow rate = 55%, average particle size = 1.0 μm, Tg = 100 ° C.) and AE852 (hollow rate = 55%, average) manufactured by JSR. Particle diameter = 1.3 μm, Tg = 100 ° C.).

  Examples of the binder resin for the coating layer include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, diisobutylene-maleic anhydride copolymer salt, styrene-maleic anhydride copolymer salt, ethylene -Acrylic acid copolymer salt, styrene-acrylic acid copolymer salt, urea resin, melamine resin, amide resin, acrylic resin, polyurethane resin: styrene, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, Vinyl polymers and copolymers such as acrylamide, methacrylamide, and methyl vinyl ether: Synthetic rubber latex such as styrene-butadiene and methyl methacrylate-butadiene resins: Polyurethane resin, polyester resin, polyamid Resins, olefin - maleic acid resins, melamine resins, and the like. In the present invention, one or more of the binder resins can be used in appropriate combination.

  Various auxiliary agents such as surfactants, pH modifiers, viscosity modifiers, softeners, gloss imparting agents, waxes, dispersants, flow modifiers, stabilizers, antistatic agents, cross-linking agents, sizing agents, fluorescent agents At least one of a whitening agent, a colorant, an ultraviolet absorber, an antifoaming agent, a water-proofing agent, a plasticizer, a lubricant, a preservative, and a fragrance may be appropriately included as necessary. In particular, in the present invention, since it is desired to reduce the content of alkali ions or water-soluble salts in the coating layer, it is preferable to refrain from adding a pH adjuster or the like as much as possible. Moreover, in order to achieve pH 4-9, it is also an effective means to mix | blend cationic resins, such as an acrylic resin, a polyamine resin, a polyacrylamide resin, and a DADMAC resin.

In the coated paper for a pressure-sensitive adhesive sheet of the present invention, the coating amount of the coating layer provided on the base paper is preferably 6 to ²⁰ g / m ² . When the coating amount is less than 6 g / m ^2, the unevenness on the surface of the base paper cannot be sufficiently covered, and the smoothness may not be optimized. On the other hand, when the amount is more than 20 g / m ² , the operability is lowered, for example, the drying property at the time of coating is deteriorated, and the production cost may be increased.

  As a coating method for forming a coating layer, generally, a conventional coating apparatus such as a blade coater, an air knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, a slot die coater, a gravure coater, a channel is used. Coating apparatuses such as a plex coater, a brush coater, a two roll, a metering blade type size press coater, a bill blade coater, a short dwell coater, and a gate roll coater can be appropriately used.

  When the smoothing process is performed on the coated base material provided with the coating layer, it is performed using a smoothing apparatus such as a normal super calendar, gloss calendar, soft calendar, or the like. The smoothing process may be appropriately performed on-machine or off-machine, and the form of the pressure device, the number of pressure nips, heating, and the like are appropriately adjusted according to a normal smoothing device. A commercially available paper in which a coating layer made of a pigment and an adhesive is previously provided on the surface of the base paper can also be used.

  The paper moisture content at the time of post-glue crimping affects the adhesive force immediately after the crimping process. When the paper moisture content is low, the adhesive strength decreases, and when the paper moisture content increases, the adhesive strength increases. In particular, the paper printed by the dry electrophotographic method is subjected to toner fixing processing with a heat roll, so that the water content of the paper after printing may be low. For this reason, when the post-glue pressure bonding process is performed, the pressure bonding straightness and sufficient adhesive force cannot be obtained, and peeling occurs at the time of transportation or the like, causing trouble. Furthermore, since the amount of paper moisture is low, static electricity is likely to be generated, which may cause troubles during transportation and paper alignment.

  That is, after printing and printing with each method (offset, inkjet, electrophotography) using the pressure-sensitive adhesive sheet coated paper of the present invention, the paper moisture content when post-glue crimping is 3 to 7%. Is preferable, and 4 to 6% is more preferable. If the moisture content of the paper is less than 3%, sufficient adhesive force cannot be obtained immediately after the post-glue crimping process, making it difficult to use as a post-crimp postcard, and the post-glue crimped product tends to generate static electricity. There is also a risk of causing trouble in the system. On the other hand, if the water content of the paper exceeds 7%, the adhesive strength after the post-glue pressure-bonding process becomes too large, so that it may not be possible to peel again.

  It is desirable to use a metal mirror roll for the high pressure treatment at the time of pressure bonding when producing a confidential postcard by the post-glue method, and the roll temperature is preferably 15 to 80 ° C, more preferably 20 to 60 ° C. . When the roll temperature is less than 15 ° C., it is difficult to develop sufficient adhesive force, and glossiness on the surface of the adhesive layer after peeling of the crimped product may be insufficient. On the other hand, when the roll temperature exceeds 80 ° C., the adhesive melts, and the adhesive strength becomes too large, so that it may not be possible to peel again.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, “parts” and “%” are parts by mass and mass% unless otherwise specified.

Example 1
[Manufacture of base paper]
LBKP (CSF freeness 550 ml) in 100 parts by weight of pulp slurry, 0.2 parts by weight of polyacrylamide resin (trade name: PS194-7, manufactured by Arakawa Chemical Industries) as a paper strength agent, polyamide as a wet paper strength enhancer Epichlorohydrin resin (trade name: WS570, manufactured by Seiko PMC Co., Ltd.) 0.2 parts by mass and sulfuric acid band 1 part by mass were added, and these mixtures were diluted with white water to have a pH of 5.3 and a solid content concentration of 1.1%. A stock was prepared. This stock is subjected to a long paper machine to make a paper, and the obtained wet paper is supplied with a size press liquid containing oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) at a concentration of 6%. The coating weight is 2 g / m ² by dry mass, dried, and further smoothed using a machine calendar so that the smoothness is 50 seconds. The basis weight is 83 g / m. ^Two base papers were produced.

[Adjustment of coating liquid-1]
Kaolin (trade name: Amazon Plus SD, manufactured by CADAM) 60 parts by weight and light calcium carbonate (trade name: Tama Pearl TP-121, manufactured by Okutama Kogyo Co., Ltd.) 40 parts by weight, sodium polyacrylate (trade name: product name) Aron T-50 (manufactured by Toagosei Co., Ltd.) was added in an amount of 0.1 part by mass, and the mixture was dispersed in water using a Coreless disperser to prepare a pigment slurry. To this pigment slurry, 3 parts by mass of oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) and 10 parts by mass of SBR latex (trade name: Smartex PA-5703C, manufactured by Nippon A & L Co., Ltd.) were added and stirred. In addition, a coating solution having a solid content concentration of 60% was prepared.

[Preparation of coated paper]
The obtained coating liquid-1 was applied to both sides of the base paper using a blade coater so that the dry coating amount per side was 12 g / m ^2, and the glossiness and surface smoothness of the coating layer Then, the super calender treatment was performed so that the air permeability was a value shown in Table 1, and a coated paper having a basis weight of 107 g / m ² was obtained. The obtained coated paper was left in an environment of 23 ° C. and 50% RH to sufficiently adjust the humidity.

[Evaluation methods]
[Glossiness measurement method]
The gloss of the coated paper obtained was measured with a gloss meter (described in JIS-Z8741) at an incident angle of 75 degrees. The measurement results are shown in Table 1.

[Measurement method of smoothness and air permeability]
The obtained coated paper was measured with a Oken type air permeability smoothness measuring machine. The measurement results are shown in Table 1.

[Method of measuring pH of paper surface]
The obtained coated paper was measured with a PH meter for measuring the paper surface (model: MPC, manufactured by Kyoritsu Riken). The measurement results are shown in Table 1.

[Measurement of Cobb water absorption]
The Cobb water absorption (described in JIS-P8140) of the coated paper obtained was measured at a measurement time of 20 seconds. The measurement results are shown in Table 1.

[Evaluation of offset printability]
The obtained coated paper was tested with a RI printing tester (model: RI-1, manufactured by Ishikawajima Industrial Machinery Co., Ltd.) and tested ink (trade name: Printing Ink Paper Test SD50 Red B T = 13, manufactured by T & K TOKA) Was printed by rotating the color cylinder with 0.5 g / metal roll. The surface state of the printed material was visually observed, and the surface was broken (paper mess) was evaluated on a five-point scale. The evaluation results are shown in Table 1.
5 points: The paper surface is not torn as in general coated paper (paper is not blurred) 4 points: Slightly disturbed on the paper surface (no paper is blurred), but good level 3 points: slightly paper Although the surface is torn (paper is blurred), there is no practical problem level 2 points: The paper surface is torn (paper is blurred) practically problematic level 1 point: The paper surface is torn all over Yes (I'm out of paper)

[Evaluation of ink-jet ink absorbency]
The obtained coated paper is printed in black and white with a commercially available inkjet printer (model: PM-800C, manufactured by Epson Corporation), and a high quality paper is applied to the printing portion immediately after that, and the ink transfer is evaluated on a five-point scale. To a practical level. The evaluation results are shown in Table 1.
5 points: Ink does not transfer to fine paper at all 4 points: Ink moves slightly to high quality paper, but practically good level 3 points: Ink moves slightly to fine paper, but there is no practical problem 2 points : There is ink transfer on high-quality paper, which is a practical problem 1 point: A lot of ink moves on high-quality paper

[Evaluation of electrophotographic printability]
The obtained coated paper was printed with a commercially available dry electrophotographic printer (model: Color ImageRUNNER iRC5185N, manufactured by Canon Inc.), and the image state immediately after was visually evaluated. The evaluation results are shown in Table 1.
○: The image is printed without any problem.
Δ: Slight toner transfer failure, blistering, etc. occur, but there is no practical problem.
X: Toner transfer failure, blistering, etc. occur, and there is a problem in image formation.

[Family postcard preparation and peeling evaluation]
3 g / m ² (solid content) of UV curable pressure bonding varnish (Dicure Acrylic UV-1451, manufactured by DIC) was applied to the resulting coated paper with a Mayer bar and irradiated with a high pressure mercury lamp 80 W / cm. Then, an adhesive layer was formed. After that, the adhesive layer is folded in half so as to face each other and cut into a postcard size, and a dry sealer (type: 6860, manufactured by Toppan Foams) is used to pass a press roll set at a roll interval of 180 μm. Crimped to make a confidential postcard. The obtained confidential postcard was cut to a width of 100 mm, and the adhesive force (peeling force) immediately after press bonding was evaluated by T-shaped peeling (peeling speed 300 mm / min). The evaluation results are shown in Table 1.
Measured value 100 to 300 gf: Practical level measured value with sufficient peeling force 301 gf or more: Peeling force is too strong, and the coated paper substrate may be destroyed when the confidential postcard is peeled again.
Measured value less than 100 gf: The peel force is too weak, and there is a possibility that the confidential postcard may be peeled off during delivery.

(Example 2)
[Adjustment of coating liquid-2]
Kaolin (trade name: Amazon Plus SD, manufactured by CADAM) 55 parts by mass, light calcium carbonate (trade name: Tama Pearl TP-121, manufactured by Okutama Kogyo Co., Ltd.), 40 parts by mass, hollow plastic pigment (trade name: AE852, manufactured by JSR) ) 5 parts by mass was added and dispersed in water using a coreless disperser to prepare a pigment slurry. To this pigment slurry, 3 parts by mass of oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) and 10 parts by mass of SBR latex (trade name: Smartex PA-5703C, manufactured by Nippon A & L Co., Ltd.) were added and stirred. In addition, a coating solution having a solid content concentration of 60% was prepared.

[Preparation of coated paper]
The obtained coating liquid-2 was applied to both sides of the base paper using a blade coater so that the dry coating amount per side was 12 g / m ^2, and the glossiness and surface smoothness of the coating layer Then, the super calender treatment was performed so that the air permeability was a value shown in Table 1, and a coated paper having a basis weight of 107 g / m ² was obtained. The obtained coated paper was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Example 3)
[Adjustment of coating liquid-3]
Light calcium carbonate (trade name: Coral Bright, manufactured by Yabashi Kogyo Co., Ltd.) and 100 parts by weight of oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) and SBR latex (trade name: Smartex PA-5703C, Japan) (A & L Co.) 10 parts by mass was added and stirred, and water was further added to prepare a coating solution having a solid content concentration of 60%.

[Preparation of coated paper]
The obtained coating liquid-3 was applied to both sides of the base paper using a blade coater so that the dry coating amount per side was 10 g / m ^2, and then the coating liquid-2 was obtained. The coated paper was coated on both sides using a blade coater so that the dry coating amount per side was 7 g / m ^2, and the glossiness, surface smoothness and air permeability of the coating layer are shown in Table 1. Super calendering was performed to obtain a value, and a coated paper having a basis weight of 117 g / m ² and two layers on both sides was obtained. The obtained coated paper was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 1)
[Adjustment of coating liquid-4]
60 parts by weight of kaolin (trade name: Amazon Plus SD, manufactured by CADAM) and 40 parts by weight of light calcium carbonate (trade name: Tama Pearl TP-121, manufactured by Okutama Kogyo Co., Ltd.) are added, and the pigment is dispersed in water using a coreless disperser. The slurry was adjusted. To this pigment slurry, 3 parts by mass of oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) and 10 parts by mass of SBR latex (trade name: Smartex PA-5703C, manufactured by Japan A & L), 3 parts by mass of caustic soda as a pH adjuster Part was added and stirred, and water was further added to prepare a coating solution having a solid concentration of 60%.

[Preparation of coated paper]
The obtained coating liquid-4 was applied to both sides of the base paper using a blade coater so that the dry coating amount per side was 12 g / m ^2, and the glossiness and surface smoothness of the coating layer Then, the super calender treatment was performed so that the air permeability was a value shown in Table 1, and a coated paper having a basis weight of 107 g / m ² was obtained. The obtained coated paper was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 2)
[Preparation of coated paper]
The coating liquid-2 was applied to both sides of the base paper using a blade coater so that the dry coating amount per side was 12 g / m ^2, and the glossiness, surface smoothness, air permeability of the coating layer was applied. Super calendering was performed so that the degree became the value shown in Table 1, and coated paper having a basis weight of 107 g / m ² was obtained. The obtained coated paper was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 3)
The coated paper having a basis weight of 107 g / m ² obtained in Example 1 was evaluated in the same manner as in Example 1, and the results are shown in Table 1. However, the coated paper used to produce the confidential postcard was dried in a 100 ° C. oven for 20 seconds and the paper moisture content was 2.5%.

(Comparative Example 4)
[Preparation of coated paper]
The coated paper having a basis weight of 107 g / m ² obtained in Example 1 was evaluated in the same manner as in Example 1, and the results are shown in Table 1. However, the coated paper at the time of preparation of the confidential postcard was left for 1 day in an environment of 50 ° C. and 90% RH, and the paper moisture content was set to 8.5%.

(Comparative Example 5)
The coated paper having a basis weight of 107 g / m ² obtained in Example 2 was evaluated in the same manner as in Example 1, and the results are shown in Table 1. However, the coated paper used to produce the confidential postcard was dried in a 100 ° C. oven for 20 seconds and the paper moisture content was 2.5%.

(Comparative Example 6)
[Preparation of coated paper]
The coated paper having a basis weight of 107 g / m ² obtained in Example 2 was evaluated in the same manner as in Example 1, and the results are shown in Table 1. However, the coated paper at the time of preparation of the confidential postcard was left for 1 day in an environment of 50 ° C. and 90% RH, and the paper moisture content was set to 8.5%.

  As Table 1 clearly shows, the coated paper for pressure-sensitive adhesive sheet according to the present invention has high gloss of white paper, predetermined smoothness, air permeability, and paper surface pH. It is suitable for offset, ink jet, electrophotographic) systems, and can exhibit a peeling force suitable for producing postcard-type confidential postcards (Examples 1 to 3). However, if any of the glossiness, smoothness, air permeability, paper surface pH, and paper moisture content of the present invention is out of the range, it does not have any suitability for each printing / printing method, or the post glue The peeling force suitable for producing the confidential postcard of the system cannot be expressed (Comparative Examples 1 to 6).

  The present invention is a pressure-sensitive adhesive sheet coated paper that can be printed by each printing / printing method (offset, ink jet, electrophotography) and has a high white paper gloss, and a postcard method for producing a confidential postcard using the same. Is obtained, and is extremely useful in practice.

Claims (8)

  An adhesive layer is provided on at least one surface of the coated paper surface after printing, and the adhesive layers can be bonded to each other by a high pressure treatment, and can be peeled between the adhesive layers after bonding. In the coated paper for a pressure-sensitive adhesive sheet used as the above, the coated paper has a base paper and at least one coating layer formed on at least one surface thereof and containing a pigment and a binder resin as main components. The coated paper has a surface smoothness of 1000 to 5000 seconds, an air permeability of 2000 to 10000 seconds, a glossiness of 50% or more, a paper surface pH of 4.0 to 9.0, and a paper moisture content of 3. Coated paper for pressure-sensitive adhesive sheet, characterized in that it is -7%. The coated paper, pressure sensitive coated paper sheet of claim 1, wherein Cobb water absorption is 15 to 80 g / m ² at 20 seconds.   The coated paper for pressure-sensitive adhesive sheets according to claim 1, wherein the organic fine particle pigment is contained in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the total pigment in the outermost coating layer.   The coated paper for pressure-sensitive adhesive sheets according to claim 3, wherein the organic fine particle pigment is a hollow plastic pigment having a hollow structure having a hollow ratio of 30 to 80%.   An adhesive layer is provided on at least one surface of the coated paper according to any one of claims 1 to 4, and the adhesive layers are subjected to high pressure treatment with a metal mirror roll during the crimping process. Processed goods.   The pressure-bonded article according to claim 5, wherein the glossiness of the surface of the adhesive layer after peeling between the adhesive layers is 55% or more.   An adhesive layer is provided on at least one surface of the coated paper according to claim 1, and a pressure-bonded product is subjected to high pressure treatment with a metal mirror roll when the adhesive layers are crimped together. Manufacturing method.   The method for producing a crimped product according to claim 7, wherein a surface temperature of the metal mirror surface roll is 15 to 80 ° C.