JP2018168232A - Adhesive sheet - Google Patents

Abstract

To provide an adhesive sheet that has a surface base material formed from a synthetic resin film and a peeling material using a paper material, which can effectively suppress occurrence of curl caused by heating even immediately after heating and after cooling, and has good fixability of a toner.SOLUTION: An adhesive sheet 1 has: a peeling material 10 which has a first clay coat layer 121 and a second clay coat layer 122 on both surfaces of a paper base material 11, has a peeling agent layer 13 on the first clay coat layer 121 and has a moisture-proof layer 14 on the second clay coat layer 122; an adhesive layer 20 on the peeling agent layer 13 of the peeling material 10; and a surface base material 30 formed from a synthetic resin film, in this order.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure-sensitive adhesive sheet, and more particularly to a pressure-sensitive adhesive sheet for a label which uses a synthetic resin film as a surface substrate and has a paper material as a release material for laser printer printing.

A general pressure-sensitive adhesive sheet for a label has a configuration in which a surface base material, a pressure-sensitive adhesive layer, and a release material are laminated in this order. As a general-purpose pressure-sensitive adhesive sheet for labels, a paper material is often used as a surface base material, but a synthetic resin film may be used as a surface base material in order to enhance the aesthetics and texture of the paper material. is there. Moreover, when using with the label for bottles used around the waters, such as a label for frozen foods, and a shampoo, a synthetic resin film is used as a surface base material in order to improve moisture resistance and water resistance.
Furthermore, since the synthetic resin film has a higher tensile strength than paper, it is used as a surface base material for labels that can be used without tearing even after repeated peeling and sticking, such as labels for wet tissues. Yes. In particular, various synthetic papers are used as the synthetic resin film when it is desired to give the surface base material a texture close to that of paper and to have the above properties.

By the way, the pressure-sensitive adhesive sheet for labels is used as a label by printing or printing various displays and information on the surface of the surface base material by various printing means. It is often desired that the pressure-sensitive adhesive sheet printing means using a synthetic resin film as a surface base material can be printed in the same manner as plain paper, and application to a laser printer is desired.
Moreover, the release material used for the pressure-sensitive adhesive sheet for general-purpose labels is discarded after use, and usually a release material using a paper material as a release substrate is used for cost reduction.

For example, in Patent Document 1, in a pressure-sensitive adhesive sheet in which a surface base material, a pressure-sensitive adhesive layer, and a release sheet are sequentially laminated, the surface base material has a synthetic resin film or synthetic paper as a support, and a pigment, There is disclosed a PPC page printer pressure-sensitive adhesive sheet having a coating layer containing an adhesive and a conductive agent, and adjusting the smoothness smoothness and the surface charge amount of the coating layer.
In the pressure-sensitive adhesive sheet described in Patent Document 1, a synthetic resin film or synthetic paper is used as a surface base material in order to improve water resistance.

Japanese Patent No. 3446234

However, when a pressure sensitive adhesive sheet using a synthetic resin film as a surface base material together with a release material having the paper material described above is printed with a laser printer, extremely large curls are generated.
In other words, the heat of the thermal transfer roll that passes when fixing the toner to the surface substrate causes the paper material of the release material to shrink due to drying, so that the positive curl (the surface substrate is outside the warped surface, the release sheet is inside) Occurs). Further, in the cooling process after passing through the thermal transfer roll, the paper material rapidly absorbs and expands, and the synthetic resin film undergoes thermal shrinkage, causing reverse curl (opposite to normal curl).
In this way, due to the difference in stretchability due to environmental changes between the paper material constituting the release material and the synthetic resin film constituting the surface base material, the dimensional difference between the two increases, and curling occurs. Conceivable.

Furthermore, the curling of the pressure-sensitive adhesive sheet that has undergone such a history is characterized in that it does not return to its original state even with a little humidity control.
Therefore, when using a synthetic resin film as a surface base material, in order to suppress the occurrence of curling after printing, the dimensional change of the surface base material and the thermal history is also at the same level in the release base material constituting the release material. Synthetic resin films such as synthetic paper are selected, and it is common to avoid the use of paper materials that differ in degree of dimensional change due to heat from the surface substrate.
However, since a release material using a synthetic resin film is expensive, an adhesive sheet that suppresses the occurrence of curling while using a release material using a paper material has been desired.

  In the pressure-sensitive adhesive sheet described in Patent Document 1, a synthetic resin film or synthetic paper is used as a surface base material. However, studies on curling suppression that may occur when a release material using a paper material is used. I have not been told.

  In the pressure-sensitive adhesive sheet having a surface substrate made of a synthetic resin film and a release material using a paper material, the present invention can effectively suppress the occurrence of curling due to heating immediately after heating and after cooling. An object of the present invention is to provide a pressure-sensitive adhesive sheet having good fixability.

  In the pressure-sensitive adhesive sheet having a surface base material made of a synthetic resin film and a release material using a paper material, the present inventor has a clay coat layer on both sides of the paper material as the release material, and one clay coat layer It has been found that the above problem can be solved by having a release agent layer on the top and a moisture-proof layer on the other clay coat layer, and the present invention has been completed.

That is, the present invention provides the following [1] to [5].
[1] A paper material has a first clay coat layer and a second clay coat layer on both sides, a release agent layer on the first clay coat layer, and a moisture-proof layer on the second clay coat layer. A release material having,
A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer and a surface substrate made of a synthetic resin film in this order on the release agent layer of the release material.
[2] The basis weight P of the paper material is 30 to 300 g / m ² , and the total application amount C of the first clay coat layer and the second clay coat layer is 10 to 60 g / m ² . 1].
[3] Ratio [P / C] of the basis weight P (g / m ² ) of the paper material and the total coating amount C (g / m ² ) of the first clay coat layer and the second clay coat layer Is a pressure-sensitive adhesive sheet according to the above [1] or [2].
[4] In any one of the above [1] to [3], the surface resistivity measured from the surface side of the moisture-proof layer is 1.0 × 10 ^{9 to} 1.0 × 10 ¹³ Ω / □. The adhesive sheet as described.
[5] The pressure-sensitive adhesive sheet according to any one of [1] to [4], which is used for printing by a laser printer.

  The pressure-sensitive adhesive sheet of the present invention has a surface base material made of a synthetic resin film and a release material using a paper material, but curling due to heating is effectively suppressed immediately after heating and after cooling. In addition, the toner has good fixability.

It is a schematic cross section of an adhesive sheet which shows an example of the adhesive sheet of this invention.

[Configuration of the pressure-sensitive adhesive sheet of the present invention]
FIG. 1 is a schematic cross-sectional view of an adhesive sheet showing an example of the adhesive sheet of the present invention.
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer 20 and a surface substrate 30 in this order on a release agent layer 13 of a release material 10 like the pressure-sensitive adhesive sheet 1 shown in FIG.
And the release material which the adhesive sheet of this invention has has the 1st clay coat layer 121 and the 2nd clay coat layer 122 on both surfaces of the paper material 11, respectively, like the release material 10 shown in FIG. The release agent layer 13 is provided on the clay coat layer 121, and the moisture-proof layer 14 is provided on the second clay coat layer 122.

Note that in one embodiment of the present invention, as in the pressure-sensitive adhesive sheet 1 illustrated in FIG. 1, the above-described layers may be directly stacked, but an arbitrary layer may be provided between two layers.
For example, as a pressure-sensitive adhesive sheet of one embodiment of the present invention, a primer layer is provided between the pressure-sensitive adhesive layer 20 and the surface base material 30 in order to improve the interlayer adhesion between the pressure-sensitive adhesive layer 20 and the surface base material 30. It is good.
Further, a print receiving layer may be further provided on the surface 30a of the surface base material 30 opposite to the pressure-sensitive adhesive layer 20 in order to easily fix the toner during printing using a laser printer. .
Hereinafter, each layer of the release material, the pressure-sensitive adhesive layer, and the surface base material constituting the pressure-sensitive adhesive sheet of the present invention will be described.

[Release material]
The release material used in the pressure-sensitive adhesive sheet of the present invention has a first clay coat layer and a second clay coat layer on both sides of the paper material, and has a release agent layer on the first clay coat layer. The moisture barrier layer 14 is provided on the coat layer.

As described above, when a pressure-sensitive adhesive sheet having a surface base material made of a synthetic resin film and a release material using a paper material is printed with a laser printer, extremely large curls are generated.
In the pressure-sensitive adhesive sheet having a surface base material made of a synthetic resin film and a release material using a paper material, the present inventors have decided to provide two clay coat layers on both sides of the paper material as the release material. The present inventors have found that the pressure-sensitive adhesive sheet can be effectively suppressed from curling.
The release material having such a configuration can increase the rigidity of the release material due to the presence of clay contained in the clay coat layer. As a result, by using the release material, the release material side resists the stress caused by the dimensional difference between the surface base material and the release material, thereby delaying the curling speed of the pressure-sensitive adhesive sheet, during which stress relaxation proceeds. Thus, it is considered that the absolute amount of curl can be reduced.

The release material used in the present invention has a release agent layer on the first clay coat layer.
In the pressure-sensitive adhesive sheet of the present invention, the release agent layer is directly laminated with the pressure-sensitive adhesive layer, and when the pressure-sensitive adhesive sheet is used, it is peeled off between the release agent layer and the pressure-sensitive adhesive layer.

Note that the release material used in one embodiment of the present invention may have a sealing layer between the first clay coat layer and the release material layer.
However, when the release agent layer is formed by applying a release agent on the first clay coat layer, the first clay coat layer serves as a sealing layer for preventing the release agent from penetrating into the paper material. Also bears.
For this reason, the release material used in one embodiment of the present invention has a configuration in which the release agent layer is directly laminated on the first clay coat layer because the need for providing the sealing layer is low.

Furthermore, the release material used in the present invention has a moisture-proof layer on the second clay coat layer.
When the pressure-sensitive adhesive sheet of the present invention is printed with a laser printer, the thermal transfer roll comes into contact with the moisture-proof layer 14 side of the pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive sheet is heated.
In the cooling process from a high temperature state immediately after printing, the release material side having a paper material easily absorbs water vapor compared to the surface base material side made of a synthetic resin film. This is due to the difference in the material that the paper material is easier to absorb water vapor than the synthetic resin film. As a result, the release material side with the paper material rapidly absorbs moisture and expands, and heat shrinkage of the synthetic resin film on the surface base material side occurs, and a new dimensional difference occurs between the release material side and the surface base material side, There may be a problem that curling occurs after cooling.

  In contrast, in the pressure-sensitive adhesive sheet of the present invention, by providing a moisture-proof layer on the release material side having a paper material, in the cooling process from a high temperature state immediately after printing, the moisture absorption rate of water vapor is suppressed, and the release material side and The dimensional difference with the surface base material side is suppressed. As a result, even after the printed pressure-sensitive adhesive sheet is allowed to stand for a while and then cooled, the occurrence of curling can be effectively suppressed as in the state immediately after printing.

The release material of the pressure-sensitive adhesive sheet of the present invention has a paper material, a first clay coat layer and a second clay coat layer that sandwich the paper material, and a moisture-proof layer on the second clay coat layer. And since it is not the structure which consists only of insulating materials like a synthetic resin film, it is easy to adjust surface resistivity low. As a result, charging on the surface base material side can also be suppressed, so that toner fixing properties can be improved.
In the case of a release material using synthetic paper, it is necessary to provide an antistatic layer in order to improve the toner fixability. On the other hand, the release material used in the present invention may be provided with an antistatic layer, but from the above viewpoint, the necessity of providing an antistatic layer is low.

In the pressure-sensitive adhesive sheet of one embodiment of the present invention, the surface resistivity measured from the surface side of the moisture-proof layer is preferably 1.0 × 10 ^{9 to} 1.0 × 10 ¹³ Ω / □.
When the surface resistivity is 1.0 × 10 ⁹ Ω / □ or more, toner fixability is good.
On the other hand, if the surface resistivity is 1.0 × 10 ¹³ Ω / □ or less, toner scattering can be prevented.

In the pressure-sensitive adhesive sheet of one embodiment of the present invention, the volume resistivity measured from the surface side of the moisture-proof layer is preferably 1.0 × 10 ^{10 to} 1.0 × 10 ¹⁴ Ω · cm.
In this specification, the surface resistivity and the volume resistivity mean values measured based on the four-terminal method defined in JIS K7194.

<Paper>
The paper material of the release material used in the present invention is mainly formed from plant fibers (pulp), and is distinguished from synthetic paper in that respect.
Examples of the paper fiber constituting the paper material include wood pulp such as NBKP and LBKP, non-wood pulp such as straw, bamboo, kenaf, bagasse and linter, and recycled pulp such as waste paper and DIP.

Note that the paper material used in one embodiment of the present invention may contain an internal filler or an internal chemical.
Examples of the internal filler include internal fillers such as inorganic fillers used in general paper production such as calcium carbonate, titanium dioxide, aluminum hydroxide, silica, talc, and clay.
These internal additives may be used alone or in combination of two or more.

  Examples of the internally added chemicals include sizing agents such as rosin size, emulsion rosin, and AKD (alkyl ketene dimer); fixing agents such as sulfate band and polyethyleneimine; paper strength agents such as acrylic amide and cationized starch; melamine, epi Wet paper strength agents such as chlorohydrin; dyes; and the like.

The paper material used in one embodiment of the present invention can be prepared by mixing these paper fibers, internal fillers, and internal chemicals with a long net paper machine, a circular paper machine, or the like.
Note that examples of the paper material used in one embodiment of the present invention include high-quality paper, craft paper, and glassine paper.
The paper material may be a single layer or a laminate of two or more.

The basis weight of the paper material is appropriately set according to the use, but is preferably 30 to 300 g / m ² , more preferably 40 to 200 g / m ² , and still more preferably 50 to 150 g / m ² .
Moreover, as thickness as a raw material of paper material, Preferably it is 5-1000 micrometers, More preferably, it is 10-500 micrometers, More preferably, it is 12-250 micrometers, More preferably, it is 15-150 micrometers.

<First clay coat layer, second clay coat layer>
The clay coat composition for forming the first clay coat layer and the second clay coat layer (hereinafter collectively referred to as “clay coat layer”) of the release material used in the present invention is a composition containing clay and a binder resin. Preferably there is.

The clay contained in the clay coating composition can be used as long as it is generally called clay or clay. For example, kaolin, talc, bentonite, smectite, vermiculite, mica, chlorite, kibushi clay, Examples include gyrome clay and halloysite.
These clays may be used alone or in combination of two or more.

  The clay content in the clay coat composition is preferably based on the total solid content (100% by mass) of the clay coat composition from the viewpoint of a pressure-sensitive adhesive sheet that can more effectively suppress curling. It is 40-95 mass%, More preferably, it is 60-90 mass%, More preferably, it is 70-85 mass%.

Examples of the binder resin contained in the clay coat composition include styrene-butadiene copolymer, ethylene-vinyl chloride copolymer, methyl methacrylate-butadiene copolymer, ethylene-vinyl acetate copolymer, (meth) acrylic acid. Emulsions of copolymers such as ester copolymers; water-soluble resins such as casein, dextrin, starch, oxidized starch, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, and polyvinyl alcohol.
These binder resins may be used alone or in combination of two or more.

  In one embodiment of the present invention, the binder resin preferably includes both a styrene-butadiene copolymer emulsion and a water-soluble resin, from the viewpoint of providing a pressure-sensitive adhesive sheet that can more effectively suppress curling. -It is more preferable that both a butadiene copolymer emulsion and polyvinyl alcohol are included.

  The content of the binder resin in the clay coat composition is preferably 5 to 60% by mass, more preferably 10 to 40% by mass, and still more preferably based on the total solid content (100% by mass) of the clay coat composition. Is 15-30 mass%.

The clay coat composition may contain other additives in addition to the clay and the binder resin.
Examples of other additives include pigments, pigment dispersants, antifoaming agents, antifoaming agents, viscosity modifiers, lubricants, water resistance agents, water retention agents, and coloring materials.

  Moreover, it is preferable to superimpose the coating surface which apply | coated the said layer on either one layer or both layers of a 1st clay coat layer and a 2nd clay coat layer, and to make the surface smooth. By carrying out the super calendar process, the paper material becomes closer, and the effect of sealing and the effect of rigidity are improved.

In one aspect of the present invention, the coating amount of the first clay coat layer, preferably 3 g / ^{m 2} or more, more preferably 5 to 30 g / ^{m 2,} more preferably from 10 to 25 g / ^{m 2.}

In one aspect of the present invention, the coating amount of the second clay coat layer, preferably 3 g / ^{m 2} or more, more preferably 5 to 30 g / ^{m 2,} more preferably from 10 to 25 g / ^{m 2.}

In the release material used in one embodiment of the present invention, when the basis weight of the paper material is in the range of 30 to 300 g / m ² , the total application amount of the first clay coat layer and the second clay coat layer is the occurrence of curling. From the viewpoint of making the pressure-sensitive adhesive sheet capable of effectively suppressing the above, it is preferably 10 to 60 g / m ² , more preferably 20 to 50 g / m ² , and still more preferably 25 to 40 g / m ² .

Furthermore, in the release material used in one aspect of the present invention, the first clay coat layer with respect to the basis weight P (g / m ² ) of the paper material from the viewpoint of forming a pressure-sensitive adhesive sheet that can more effectively suppress the occurrence of curling. And the ratio [C / P] of the total coating amount C (g / m ² ) of the second clay coat layer is preferably 0.2 to 0.7, more preferably 0.25 to 0.6, and still more preferably. 0.3 to 0.5.

<Release layer>
The release agent layer of the release material used in the present invention can be formed from a release agent composition containing a release component on the first clay coat layer.
Examples of the peelable component contained in the release agent composition that is a material for forming the release agent layer include alkyd resins, silicone resins, fluorine resins, unsaturated polyester resins, polyolefin resins, and waxes. It is done.
These peelable components may be used alone or in combination of two or more.
Among the releasable components contained in these release agent compositions, a silicone-based resin is preferable from the viewpoint of forming a heat-resistant release agent layer.

  The thickness of the release agent layer is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and still more preferably 0.1 to 2 μm, from the viewpoints of releasability and coating curability.

<Dampproof layer>
The moisture-proof layer of the release material used in the present invention is preferably formed from a moisture-proof layer-forming composition containing a water-dispersed resin that functions as a moisture-proof agent.
Examples of the water dispersible resin include polyolefin resins (polyethylene, polypropylene, etc.), vinyl chloride resins, styrene resins, styrene-butadiene copolymers, acrylonitrile-styrene copolymers, acrylonitrile-butadiene copolymers, ABS resins, AAS resin, AES resin, vinylidene chloride resin, polyurethane resin, poly-4-methylpentene-1 resin, polybutene-1 resin, vinylidene fluoride resin, vinyl fluoride resin, fluorine resin, polycarbonate resin, polyamide resin, acetal resin, Polyphenylene oxide resin, polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polyphenylene sulfide resin, polyimide resin, polysulfone resin, polyethersulfone resin, aromatic polyester Ether resins, polyarylate resins, and the like modified products and the like, it is preferred that these resins are emulsion.
These water-dispersible resins may be used alone or in combination of two or more.

  Among these, the water-dispersible resin used in one embodiment of the present invention is preferably an emulsion of a resin selected from a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, and vinylidene chloride.

  In addition to the above water-dispersed resin, the moisture-proof layer-forming composition includes wax components such as paraffin wax and polyethylene wax; starch; oxidized starch, etherified starch, dialdehyde starch, esterified starch, etc. Modified starch; polyvinyl alcohol or the like.

From the viewpoint of forming a moisture-proof layer with improved moisture resistance, the moisture-proof layer-forming composition may further contain an inorganic pigment.
Examples of the inorganic pigment include calcium carbonate, magnesium carbonate, silicon dioxide, titanium dioxide, zinc oxide, aluminum oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, zinc sulfate, kaolin, talc, calcined kaolin, Examples include lithopone and satin white.
These inorganic pigments may be used alone or in combination of two or more.

In the pressure-sensitive adhesive sheet of one embodiment of the present invention, the moisture-proof layer forming composition may further contain a thermosetting resin from the viewpoint of forming a moisture-proof layer with improved film strength and heat resistance.
Examples of the thermosetting resin include amino resins such as melamine resins, polyvalent epoxy resins, aldehyde resins, polyvalent isocyanate resins, and phenol resins.
These thermosetting resins may be used alone or in combination of two or more.

The coating amount of the moisture-proof layer is preferably 1 to 10 g / ^{m 2,} more preferably 2 to 8 g / ^{m 2,} more preferably from 3 to 6 g / ^{m 2.}

Moreover, since the moisture-proof layer is formed from the composition containing the above-mentioned water-dispersed resin, blocking may occur when it becomes wet.
For this reason, the release material used in one embodiment of the present invention may be provided with an anti-blocking layer on the surface of the moisture-proof layer opposite to the second clay coat layer.
Examples of the material for forming the anti-blocking layer include styrene acrylic resin.

(Adhesive layer)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention can be formed from a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive resin.
The pressure-sensitive adhesive resin is appropriately selected depending on the application. For example, acrylic resin, urethane resin, rubber resin, olefin resin, silicone resin, and these resins have a polymerizable functional group. Examples include energy ray curable resins.
These adhesive resins may be used independently and may use 2 or more types together.

Moreover, the pressure-sensitive adhesive composition that is a material for forming the pressure-sensitive adhesive layer may contain an additive for pressure-sensitive adhesives depending on the type of pressure-sensitive resin and the application of the pressure-sensitive adhesive sheet.
Examples of the adhesive additive include a crosslinking agent, a tackifier, a filler, an antioxidant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, a colorant, a flame retardant, a thickener, and an antistatic agent. , Polymerization initiators, curing aids and the like.

  The thickness of the pressure-sensitive adhesive layer is appropriately set according to the use, but is preferably 1 to 100 μm, more preferably 5 to 80 μm, and still more preferably 10 to 60 μm.

[Surface substrate]
The surface substrate of the pressure-sensitive adhesive sheet of the present invention may be a synthetic resin film, and is preferably synthetic paper.

The synthetic paper is composed of synthetic fibers made of resin such as polypropylene, polystyrene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, and polyamide. And the like.
In addition, as the synthetic paper used in the present invention, a commercially available product may be used. For example, “Crisper (registered trademark)” (manufactured by Toyobo Co., Ltd., void-containing polyester synthetic paper), “YUPO (registered trademark)” (Manufactured by Yupo Corporation, void-containing polypropylene synthetic paper), “Laser Peach” (manufactured by Nisshinbo Paper Products Co., Ltd., polyester synthetic paper) and the like.
Among these, polyester-based synthetic paper is more preferable as the surface substrate.

  Examples of the resin constituting the synthetic resin film other than the synthetic paper used for the surface substrate include polyolefin resins such as polyethylene and polypropylene; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene -Vinyl resin such as vinyl alcohol copolymer; Polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; Polystyrene; Acrylonitrile-butadiene-styrene copolymer; Cellulose triacetate; Polycarbonate; Polyurethane, Acrylic modified polyurethane Such as urethane resin; polymethylpentene; polysulfone; polyetheretherketone; polyethersulfone; polyphenylene sulfide; polyetherimide, polyi Polyamide resin; polyimide-based resin such as de like fluorine resin or the like; acrylic resin.

The synthetic resin film may further contain various additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, and a colorant.
Further, the surface base material may be a single layer or a multilayer in which two or more layers are laminated.

The surface base material used in one embodiment of the present invention is a surface treatment by an oxidation method, a concavo-convex method, or the like with respect to the surface of the synthetic resin film constituting the surface base material from the viewpoint of improving the adhesion with the pressure-sensitive adhesive layer. Alternatively, a primer layer may be provided.
Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), hot air treatment, ozone and ultraviolet irradiation treatment.
Examples of the unevenness method include a sand blast method and a solvent treatment method.

  The thickness of the surface substrate is appropriately set depending on the application, but is preferably 5 to 1000 μm, more preferably 10 to 700 μm, still more preferably 20 to 500 μm, and still more preferably 30 to 300 μm.

  In the pressure-sensitive adhesive sheet of one embodiment of the present invention, the surface of the surface base material on the side opposite to the pressure-sensitive adhesive layer is used from the viewpoint of good fixation of toner, ink, etc. during printing using a laser printer or the like. Furthermore, you may have a printing receptive layer.

[Method for producing adhesive sheet]
There is no restriction | limiting in particular as a method of manufacturing the adhesive sheet of this invention, For example, the method which has following process (1)-(5) is mentioned.
Step (1): A step of forming a first clay coat layer on one side of the paper material.
Step (2): A step of forming a release agent layer on the first clay coat layer.
Step (3): A step of forming a second clay coat layer on the other side of the paper material.
Step (4): A step of forming a moisture-proof layer on the second clay coat layer.
Step (5): A step of forming a pressure-sensitive adhesive layer on the release agent layer and laminating a surface base material on the exposed surface of the pressure-sensitive adhesive layer.

In said manufacturing method, although the order of process (1)-(5) is not ask | required, after producing a peeling material through process (1)-(4), it is preferable to pass through process (5).
In addition, in said aspect, the order of process (1)-(4) which produces a peeling material does not ask | require.

For example, after the step (1), the step (3) is performed, and the first clay coat layer and the second clay coat layer are simultaneously formed on both surfaces of the paper material, and then the steps (2) and (4) may be performed. .
Steps (1) and (3) may be performed simultaneously in one step, and the first clay coat layer and the second clay coat layer may be simultaneously formed on both sides of the paper material.
Similarly, the steps (2) and (4) may be performed simultaneously in one step to form the release agent layer and the moisture-proof layer at the same time.

As a formation method of each layer in each process, it can form by apply | coating the composition which is the formation material of each layer, forming a coating film, and drying the said coating film.
In addition to the components contained in each layer, the composition may be in the form of a solution by adding a solvent as necessary from the viewpoint of improving coatability.

  As the coating method, known methods can be applied, and examples thereof include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.

[Characteristics of adhesive sheet]
The pressure-sensitive adhesive sheet of the present invention is suitable for uses involving heating as described above, but is particularly preferably used for printing with a laser printer.
That is, the pressure-sensitive adhesive sheet of the present invention can effectively suppress the occurrence of curling even after printing by a laser printer, or immediately after printing and after leaving and cooling. Further, since the surface resistivity on the release material side is adjusted to be low and the generation of static electricity can be suppressed, the fixing property of the toner on the surface base material side which is the printing surface is also improved.

  The present invention will be specifically described with reference to the following examples, but the present invention is not limited to the following examples.

The material for forming each layer used in the following examples and comparative examples is as follows.
<Paper>
High-quality paper (manufactured by Nippon Paper Industries Co., Ltd., product name “Joshitsu AB-EC85G”), basis weight = 85 g / m ² , thickness as raw material = 134 μm.
<Surface base material>
Polyester synthetic paper (product name “Crisper (registered trademark) 7911” manufactured by Toyobo Co., Ltd.), thickness = 50 μm.

<Release composition>
To 100 parts by mass of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name “KS-847”), 1 part by mass of a platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., product name “PL-50T”) is added, and toluene is added. A composition prepared by diluting with a solid content concentration of 10% by mass.
<Clay coat composition (formation material of the first clay coat layer and the second clay coat layer)>
As a clay component, kaolin clay second grade (product name "Case S" manufactured by Imeris Mineral Japan Co., Ltd.), 80 parts by mass (in terms of solid content, hereinafter the same), styrene-butadiene copolymer (Nippon A & L Co., Ltd.) as a binder resin component Manufactured, product name “Smarter SN-307R”) 9 parts by mass, oxidized starch (manufactured by Nippon Starch Co., Ltd., product name “Sanasu 350”), and polyvinyl alcohol (manufactured by Kuraray Co., Ltd. Kuraray Poval PVA-117 ") 2 parts by weight, and further diluted with water to a solid content concentration of 36% by weight.
<Composition for moisture-proof layer formation>
A composition containing a vinylidene chloride resin (product name “Saran Latex L-411A” manufactured by Asahi Kasei Corporation).
<Composition for blocking prevention layer formation>
A composition containing a styrene acrylic resin (product name “Bonlon S-1318NF” manufactured by Mitsui Chemicals, Inc.).

Example 1
(1) Production of release material On both sides of the paper material, using a double-side coater, the clay coat composition was applied to form a coating film, and both coating films were dried at 150 ° C. for 20 seconds, In both cases, a first clay coat layer and a second clay coat layer having a coating amount of 16 g / m ² were formed. Subsequently, the obtained sheet was subjected to a supercalender treatment by passing through a metal multi-stage roll to prepare a double-sided clay-coated paper having a layer thickness of 130 μm.
Next, the release agent composition was applied onto the first clay coat layer to form a coating film, and the coating film was dried at 150 ° C. for 20 seconds to form a release agent layer having a thickness of 1 μm.
Further, the moisture proof layer forming composition is applied onto the second clay coat layer to form a coating film, and the coating film is dried at 100 ° C. for 1 minute to form a moisture proof layer with a coating amount of 4 g / m ^2. Formed. Subsequently, the anti-blocking layer forming composition is applied onto the moisture-proof layer to form a coating film, and the coating film is dried at 100 ° C. for 30 seconds, so that the coating amount is 1 g / m ^2. To form a release material (1).
(2) Production of pressure-sensitive adhesive sheet On the release agent layer of the produced release material (1), an acrylic pressure-sensitive adhesive (manufactured by Lintec Corporation, product name “PAT1”) is applied to form a coating film. It dried at 100 degreeC for 1 minute, and formed the 20-micrometer-thick adhesive layer. And said surface base material was laminated | stacked on the surface of the said adhesive layer, and adhesive sheet (I) was obtained.

Comparative Example 1
A release material (2) was produced in the same manner as in Example 1 except that the moisture-proof layer and the anti-blocking layer were not formed.
And the adhesive sheet (II) was obtained like Example 1 using the peeling material (2).

Comparative Example 2
A release material (3) was prepared in the same manner as in Example 1 except that a moisture proof layer and then a blocking prevention layer were formed on one side of the paper material without forming the second clay coat layer.
And the adhesive sheet (III) was obtained like Example 1 using the peeling material (3).

Comparative Example 3
As the release material (4), using a polyester synthetic paper (product name “Chrisper K7245”, thickness 50 μm, manufactured by Toyobo Co., Ltd.) having a release agent layer on one side and an antistatic layer on the opposite side, In the same manner as in Example 1, an adhesive sheet (IV) was obtained.

Comparative Example 4
A release material (5) was obtained in the same manner as in Example 1 except that the second clay coat layer, the moisture-proof layer, and the anti-blocking layer were not formed.
And the adhesive sheet (V) was obtained like Example 1 using the peeling material (5).

Comparative Example 5
A release sheet (VI) is obtained in the same manner as in Example 1 using a release material (product name “8E”, manufactured by Lintec Corporation) made of single-sided laminated paper having a release agent layer as the release material (6). It was.

Comparative Example 6
On the surface opposite to the release agent layer of the release material (6), the above moisture-proof layer forming composition is applied to form a coating film. The coating film is dried at 100 ° C. for 1 minute, and the coating amount is 4 g / m. ^Two moisture barrier layers were formed. Subsequently, the anti-blocking layer forming composition is applied onto the moisture-proof layer to form a coating film, and the coating film is dried at 100 ° C. for 30 seconds, so that the coating amount is 1 g / m ^2. To form a release material (7).
And adhesive sheet (VII) was obtained like Example 1 using the peeling material (7).

Comparative Example 7
As a release material (8), using a release material having a release agent layer on one surface of glassine paper (product name “7K white” manufactured by Lintec Corporation), in the same manner as in Example 1, an adhesive sheet ( VIII) was obtained.

Comparative Example 8
On the surface opposite to the release agent layer of the release material (8), the above moisture-proof layer-forming composition is applied to form a coating film, and the coating film is dried at 100 ° C. for 1 minute. A moisture-proof layer of m ² was formed. Subsequently, the anti-blocking layer forming composition is applied onto the moisture-proof layer to form a coating film, and the coating film is dried at 100 ° C. for 30 seconds, so that the coating amount is 1 g / m ^2. To form a release material (9).
And adhesive sheet (IX) was obtained like Example 1 using the peeling material (9).

Table 1 summarizes the structures of the release materials (1) to (9) included in the pressure-sensitive adhesive sheets (I) to (IX) produced as described above.
Moreover, the following evaluation and measurement were performed about adhesive sheet (I)-(IX). These results are shown in Table 2.

(1) Evaluation method for curling suppression effect of pressure-sensitive adhesive sheet The prepared pressure-sensitive adhesive sheet was A4 size, and color printed using a laser printer (product name “LBP-9600” manufactured by Canon Inc.).
Then, within 30 seconds immediately after printing (immediately after printing), after 2 minutes have elapsed after printing (after air cooling), and after standing for 24 hours in an environment of 23 ° C. and 50% RH (relative humidity) (after humidity control) The warped surface side of the adhesive sheet was left on a flat table, the height of the adhesive sheet from the four corner tables was measured, and the maximum curl height was determined. In addition, the maximum value of the curl height described in Table 1 is the maximum value when the curled state is a regular curl (a surface base material is a curled surface outside and a release material is a curled surface inside). In the case of reverse curl (a curl in which the surface base material is inside the warped surface and the release material is outside the warped surface), the sign of the maximum value is marked as negative.
Moreover, based on the maximum value of the curl height (maximum absolute value), the curl suppression effect was evaluated according to the following criteria.
(Curl evaluation immediately after printing and after air cooling)
-5: The maximum value of the curl height (the absolute value of the numerical values in Table 1) is 0 mm or more and less than 15 mm.
-4: The maximum value of the curl height (the absolute value of the values in Table 1) is 15 mm or more and less than 30 mm.
-3: The maximum value of the curl height (the absolute value of the numerical values in Table 1) is 30 mm or more and less than 50 mm.
-2: The maximum value of the curl height (the absolute value of the numerical values in Table 1) is 50 mm or more and less than 70 mm.
1: The maximum value of curl height (the absolute value of the numerical values in Table 1) is 70 mm or more.
(Curl evaluation after humidity control)
* 5: The maximum value of the curl height (the absolute value of the values in Table 1) is 0 mm or more and less than 5 mm.
-4: The maximum value of the curl height (the absolute value of the values in Table 1) is 5 mm or more and less than 10 mm.
* 3: The maximum value of the curl height (the absolute value of the numerical values in Table 1) is 10 mm or more and less than 20 mm.
-2: The maximum value of the curl height (the absolute value of the numerical values in Table 1) is 20 mm or more and less than 30 mm.
1: The maximum value of curl height (the absolute value of the numerical values in Table 1) is 30 mm or more.

(2) Surface resistivity, volume resistivity Each adhesive sheet using a resistivity meter “Loresta GP MCP-T600” (product name, manufactured by Mitsubishi Chemical Corporation) based on the four-terminal method defined in JIS K7194 The surface resistivity and volume resistivity were measured from the release material side.

(3) Evaluation method of printability of pressure-sensitive adhesive sheet A predetermined standard image was color-printed on the produced pressure-sensitive adhesive sheet using a laser printer (manufactured by Canon Inc., product name “LBP-9600”).
If the toner scatters immediately after printing and the image is blurred, it is evaluated as “x”, and the toner is fixed on the surface substrate without any problem, and the reference image is obtained as “◯”. evaluated.

  From Table 2, the pressure-sensitive adhesive sheet (I) prepared in Example 1 was compared with the pressure-sensitive adhesive sheets (II) to (IX) prepared in Comparative Examples 1 to 8 immediately after printing, after air cooling, and after humidity conditioning. As a result, an excellent curling suppression effect was exhibited. Further, the pressure-sensitive adhesive sheet (I) had good printability and excellent toner fixability.

DESCRIPTION OF SYMBOLS 1 Adhesive sheet 10 Release material 11 Paper material 121 1st clay coat layer 122 2nd clay coat layer 13 Release agent layer 14 Moisture-proof layer 20 Adhesive layer 30 Surface base material 30a Surface

Claims (5)

A release material having a first clay coat layer and a second clay coat layer on both sides of the paper material, a release agent layer on the first clay coat layer, and a moisture-proof layer on the second clay coat layer When,
A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer and a surface substrate made of a synthetic resin film in this order on the release agent layer of the release material. ^2. The pressure-sensitive adhesive according to claim 1, wherein a basis weight of the paper material is 30 to 300 g / m ² , and a total coating amount of the first clay coat layer and the second clay coat layer is 10 to 60 g / m ^2. Sheet. The ratio [C / P] of the total application amount C (g / m ² ) of the first clay coat layer and the second clay coat layer to the basis weight P (g / m ² ) of the paper material is 0. The pressure-sensitive adhesive sheet according to claim 1 or 2, which is 2 to 0.7. The adhesive sheet as described in any one of Claims 1-3 whose surface resistivity measured from the surface side of the said moisture-proof layer is 1.0 * 10 < ⁹ > -1.0 * 10 < ¹³ > ohm / square.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, which is used for printing with a laser printer.