JP2009286962A - Tack paper - Google Patents

Abstract

[PROBLEMS] To improve initial adhesive strength and surface adhesive strength, whether it is stored for a long period of time in a high temperature and humidity environment, a normal temperature and normal humidity environment, whether it is used or not, even if it is used. Provided is a tack paper having a pressure-sensitive adhesive layer with a low degree of decrease.
SOLUTION: An acrylic resin, a crosslinking agent, an acidic resin are used as a water-based adhesive used for a tack paper in which a release paper is pasted through a pressure-sensitive adhesive layer formed by applying a water-based adhesive on a substrate. And a tackifier having an acid value of 10 KOHmg / g to 100 KOHmg / g mainly composed of a group-containing rosin resin. The content of the crosslinking agent in the pressure-sensitive adhesive is 0.30 to 1.2 parts by mass with respect to 100 parts by mass of the acrylic resin, and the content of the tackifier is 1 with respect to 100 parts by mass of the acrylic resin. From 0.0 part by mass to 1.7 parts by mass.
[Selection figure] None

Description

  The present invention relates to a tack paper in which adhesive properties such as adhesive strength do not deteriorate even when stored for a long period of time in a high temperature and high humidity environment using an acrylic resin, a specific tackifier, and a crosslinking agent.

  The tack paper is said to have a three-layer structure in which an adhesive layer is formed on the surface (or release paper surface) of a base material, and the release paper (or base material) is bonded to the adhesive layer. 2. Description of the Related Art Tack paper has been increasingly used as an adhesive for various articles as a physical distribution label or the like.

The tack paper as described above is required to have excellent heat resistance, weather resistance, water resistance, oil resistance and the like in addition to basic physical properties (basic adhesive properties) such as tack, adhesive strength, and cohesive strength. Examples of the pressure-sensitive adhesive satisfying such requirements include acrylic pressure-sensitive adhesives widely used in pressure-sensitive adhesive products such as pressure-sensitive adhesive labels, sheets, and tapes (Patent Document 1).
JP 2006-069956 A

  Even if it is a tack paper using an acrylic pressure-sensitive adhesive having a good basic adhesive property as a pressure-sensitive adhesive layer, the adhesion between the pressure-sensitive adhesive layer and the article is maintained after the tack paper is bonded to the adherend. The problem is that it cannot be peeled off and is easily peeled off. Therefore, in order to prevent the tack paper from being easily peeled off from the adherend after the tack paper is bonded to the adherend, the adhesive layer is required to further improve the initial adhesive strength and the initial surface adhesive strength. It has been.

  In addition, the tack paper has a certain period after being completed until it is used. Therefore, the tack paper is stored in a warehouse or the like until it is used after being manufactured, or the purchaser stores it in a predetermined place. For this reason, there is a need for a tack paper that does not decrease the adhesive strength and surface adhesive strength of the pressure-sensitive adhesive layer over time even if the tack paper is stored for a long time in a high-temperature and high-humidity environment. In addition, if the tack paper is once bonded to the adherend and left in a high-temperature and high-humidity environment at room temperature and humidity for a long period of time, the adhesive strength and the surface adhesive strength of the tack paper greatly decrease. It becomes a problem that it becomes easy to peel off. Therefore, there is a demand for tack paper that does not easily peel once attached to an adherend.

  The present invention has been made in order to solve the above-described problems, and its purpose is to increase the initial adhesive strength and initial surface adhesive strength of the adhesive layer of the tack paper, and whether it is used before or during use. It is another object of the present invention to provide a tack paper having a pressure-sensitive adhesive layer in which the degree of decrease in adhesive strength and surface adhesive strength is small even when stored and left for a long period of time in a high-temperature and high-humidity environment or a normal temperature and normal humidity environment.

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, the pressure-sensitive adhesive layer included in the tack paper includes an acrylic resin, a crosslinking agent, and a tackifier mainly composed of an acidic group-containing rosin resin, and the acid value of the tackifier is from 10 KOHmg / g to 100 KOHmg. / G, the content of the tackifier is 1.0 to 1.7 parts by mass with respect to 100 parts by mass of the acrylic resin, and the content of the crosslinking agent is 100 parts by mass of the acrylic resin. On the other hand, the present inventors have found that the above-mentioned problems can be solved if the amount is 0.30 parts by mass to 1.2 parts by mass, and the present invention has been completed. More specifically, the present invention provides the following.

  (1) A tack paper in which a release paper is pasted through an adhesive layer formed by applying an aqueous adhesive on a substrate, the aqueous adhesive comprising an acrylic resin, a crosslinking agent, A tackifier mainly composed of an acid group-containing rosin resin, and the acid value of the tackifier is from 10 KOHmg / g to 100 KOHmg / g, and the content of the tackifier is an acrylic resin. 1.0 to 1.7 parts by mass with respect to 100 parts by mass, and the content of the crosslinking agent is 0.30 to 1.2 parts by mass with respect to 100 parts by mass of the acrylic resin. A tuck paper.

(2) The pressure-sensitive adhesive force of the pressure-sensitive adhesive layer in a method based on JIS Z0237 is from 1,850 gf / 25 mm to 2,500 gf / 25 mm,
Tack paper according to the probe tack of the adhesive layer in a manner conforming to JIS Z0237 is at 250 kN / ^{m 2} from 130kN / ^{m 2} (1).

  In the present specification, the adhesive strength means the adhesive strength of the pressure-sensitive adhesive layer including the initial adhesive strength, and indicates all of the initial adhesive strength, the adhesive strength during storage, and the adhesive strength during use.

  In this specification, the probe tack may be expressed as surface adhesive force. The surface adhesive strength is the surface adhesive strength of the pressure-sensitive adhesive layer and refers to all of the initial surface adhesive strength, the surface adhesive strength during storage, and the surface adhesive strength during use.

  (3) The change rate of the adhesive strength of the pressure-sensitive adhesive layer after one month when left in an environment of 40 ° C. and 90% humidity for one month is the adhesive strength before leaving -20% to 20% with respect to the probe tack of the pressure-sensitive adhesive layer after one month when left in an environment of 40 ° C. and 90% humidity for one month, according to JIS Z0237. The tack paper according to (1) or (2), wherein the rate of change is -20% to 20% with respect to the probe tack before being left standing.

(4) it is peeled off the release paper, the adhesive layer, after the basis weight was attached to an adherend made of high quality paper from 64.0 g / ^{m 2} of 157.0 g / ^{m 2,} a tensile speed of 300 mm / The tack paper according to any one of (1) to (3), wherein the adherend is destroyed when peeled from the adherend at a peeling angle of 180 °.

  In the present invention, the pressure-sensitive adhesive layer of the tack paper includes an acrylic resin, a crosslinking agent, and a tackifier mainly composed of an acidic group-containing rosin resin, and the acid value of the tackifier is from 10 KOHmg / g to 100 KOHmg / g. The tackifier content is 1.0 to 1.7 parts by mass with respect to 100 parts by mass of the acrylic resin, and the content of the crosslinking agent is 100 parts by mass with respect to the acrylic resin. 0.30 parts by mass to 1.2 parts by mass. By using a tackifier having an acid value of 10 KOH mg / g to 100 KOH mg / g, high initial adhesive strength and high initial surface adhesive strength can be realized. Moreover, the initial stage adhesive force and initial stage adhesive force of an adhesive layer can be maintained for a long period of time by making content of the crosslinking agent in an adhesive layer into the said range. Accordingly, the pressure-sensitive adhesive layer of the tack paper of the present invention has high initial adhesive strength and initial surface adhesive strength, and can maintain these high adhesive strength and surface adhesive strength for a long period of time. Does not peel off easily from the adherend.

  Hereinafter, an embodiment of the present invention will be described in detail. However, the present invention is not limited to the following embodiment, and may be implemented with appropriate modifications within the scope of the object of the present invention. it can.

<Tack paper>
The tack paper of this invention has a base material, the adhesive layer formed in the base-material surface (or release paper surface), and the release paper (or base material) bonded together to the adhesive layer. The acid value of the tackifier contained in the pressure-sensitive adhesive layer is 10 KOHmg / g to 100 KOHmg / g, and the content of the tackifier is 1.0 part by mass to 1.7 parts by mass with respect to 100 parts by mass of the acrylic resin. It is a feature of the present invention that the content of the crosslinking agent in the pressure-sensitive adhesive layer is 0.30 parts by mass to 1.2 parts by mass with respect to 100 parts by mass of the acrylic resin. Hereinafter, the tack paper of the present invention will be described in the order of the pressure-sensitive adhesive layer, the substrate, and the release paper.

[Adhesive]
The pressure-sensitive adhesive layer of the present invention is formed using a water-based pressure-sensitive adhesive containing an acrylic resin, a crosslinking agent, and a tackifier mainly composed of an acidic group-containing rosin resin.

  The acrylic resin used for this invention is not specifically limited, The conventionally well-known thing obtained by polymerizing the following acrylic monomer or methacrylic monomer ((meth) acrylic monomer) can be used.

  Acrylic monomers and methacrylic monomers are not particularly limited, but alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and octyl (meth) acrylate. Esters, (meth) acrylic acid cycloalkyl esters such as (meth) acrylic acid cyclohexyl, (meth) acrylic acid aryl esters such as (meth) acrylic acid phenyl and (meth) acrylic acid benzyl, (meth) acrylic acid 2-hydroxy Hydroxyl-containing monomers such as ethyl, epoxy group-containing monomers such as allyl glycidyl ether and (meth) acrylic acid glycidyl ether, fluorine-substituted (meth) acrylic acid alkyl esters, (meth) acrylonitrile, and vinyl such as styrene and methylstyrene Group containing Family compounds, vinyl acetate, and halogenated vinyl compounds. Among these, a hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate is particularly preferable. In addition, (meth) acrylic acid means both acrylic acid and methacrylic acid.

  The tackifier has an acid value of 10 KOHmg / g to 100 KOHmg / g, and the content of the tackifier is 1.0 part by mass to 1.7 parts by mass with respect to 100 parts by mass of the acrylic resin. It is characterized by mainly comprising a resin. By using a rosin-based resin containing an acidic group as a tackifier, an acid value is imparted to the pressure-sensitive adhesive layer, and by having polarity, adhesion with a polar adherend is improved. By improving the adhesion, the initial adhesive strength and the initial surface adhesive strength of the adhesive layer of the tack paper are improved.

  Examples of the tackifier that can be used in the present invention include modified rosins such as maleated rosin, fumarated rosin and acrylated rosin, stabilized rosin subjected to disproportionation / dimerization / hydrogenation, and the like. Examples include rosin resins such as those obtained by esterifying rosin with glycerin or pentaerythritol, xylene resins, terpene resins, terpene phenol resins, petroleum resins, coumarone indene resins, styrene resins, ethylene / vinyl acetate resins, and the like. Among these, modified rosin and rosin resin are particularly preferable. Examples of commercially available tackifiers that can be preferably used in the present invention include Harima Chemicals Co., Ltd., trade name “Harry Star SK-370N, acid value: 58 to 65 KOH mg / g”, and the like, since it contains almost no acidic group. Commercially available tackifiers that cannot be used in the present invention include those manufactured by Harima Kasei Co., Ltd., trade name “Harry Star SK-501NS, acid value: <10 KOH mg / g”, trade name “Harry Star SK-218NS, acid value: <10 KOH mg / g ”and the like.

  In the present invention, the acid value of the tackifier contained in the pressure-sensitive adhesive layer is 10 KOHmg / g to 100 KOHmg / g. When the acid value is in the above range, high initial adhesive strength and high initial surface adhesive strength can be realized.

  Content of the tackifier in an adhesive layer is 1.0 mass part to 1.7 mass parts with respect to 100 mass parts of acrylic resins. If the content of the tackifier is in the above range, the initial adhesive strength and initial surface adhesive strength of the adhesive layer are extremely high.

  By setting the content of the tackifier in the pressure-sensitive adhesive layer within the above range, the pressure-sensitive adhesive layer of the tack paper of the present invention can maintain very high adhesive strength and surface adhesive strength. As a result, the tack paper once bonded to the adherend can be prevented from peeling off from the adherend. The tack paper is bonded to the adherend, and then the adhesive layer is strong enough to cause material destruction of the adherend when the tack paper is peeled off from the adherend at a pulling speed of 300 mm / min and a peeling angle of 180 °. And adherend adhere to each other. Examples of the adherend include a paper base material that is not coated with resin coating for easy adhesion, PE resin impregnation, and the like, more specifically, a paper base such as Mitsubishi Paper Diaform N. Materials.

  The crosslinking agent contained in the pressure-sensitive adhesive used in the present invention is not particularly limited, and a conventionally known crosslinking agent can be used. Examples of conventionally known crosslinking agents include carbodiimide crosslinking agents, epoxy crosslinking agents, isocyanate crosslinking agents, oxazoline compounds, metal chelate compounds, metal alkoxides, amine compounds, and the like. Among these, a carbodiimide type crosslinking agent and an epoxy type crosslinking agent are preferable. In particular, carbodiimide-based crosslinking agents are preferable because of their excellent reactivity with active hydrogen groups.

  By including a cross-linking agent, the adhesive strength and surface adhesive strength of the adhesive layer can be determined from the initial adhesive strength and initial surface adhesive strength even when stored and left for a long period of time in a high temperature and high humidity environment. The degree of decrease is small, and the above-mentioned high initial adhesive force and initial surface adhesive force can be maintained for a long time.

  “In a high temperature and high humidity environment” means an environment where the temperature exceeds 35 ° C. and the humidity exceeds 85%. “Under normal temperature and humidity” refers to an environment where the temperature is in the range of 5 ° C. to 35 ° C. and the humidity is in the range of 45% to 85%.

As the carbodiimide crosslinking agent, a compound having two or more carbodiimide groups can be used and is not particularly limited. In addition, a carbodiimide group shows the group (-N = C = NH, -N = C = N-) by which one or two hydrogen atoms were extracted from carbodiimide (HN = C = NH). For example, a compound represented by R ¹ —N═C═N—R ² —N═C═N—R ³ (R ¹ , R ² , and R ³ all represent a hydrocarbon group) is exemplified. . In addition to the carbodiimide group, a polymer having a portion excellent in affinity with water, such as an ethylene oxide (—CH ₂ —CH ₂ —O—) portion, can be used particularly preferably. Examples of commercially available polymers having a carbodiimide group (polycarbodiimide) that can be used as a carbodiimide crosslinking agent in the present invention include, for example, Nisshinbo Co., Ltd., trade names “Carbodilite V-02”, “Carbodilite V-02-L2”, “Carbodilite V-04”, “Carbodilite E-01”, “Carbodilite E-02”, “Carbodilite E-03” and the like. A carbodiimide crosslinking agent can be used 1 type or in combination of 2 or more types.

  The compounding quantity of a crosslinking agent is 0.30 mass part to 1.2 mass parts with respect to 100 mass parts of acrylic resins. Preferably it is 0.5 mass part to 1.0 mass part. Generally, if the amount of the crosslinking agent is too small, the cohesive force of the pressure-sensitive adhesive layer is lowered, and cohesive failure is likely to occur. Moreover, when there is too much quantity of a crosslinking agent, since bridge | crosslinking advances excessively and wettability will fall, adhesive force will fall and it is unpreferable. Moreover, the adhesive layer can maintain high initial adhesive force and high initial surface adhesive force by making the compounding quantity of a crosslinking agent into the said range. The tack paper of the present invention includes a pressure-sensitive adhesive layer having high adhesive strength and surface adhesive strength even after storage and standing for a long period of time, so that the tack paper once pasted is not peeled off from the adherend.

  In particular, due to the synergistic effect of the cross-linking agent content in the pressure-sensitive adhesive layer within the above range and the tackifier having an acid value of 10 KOHmg / g to 100 KOHmg / g, the initial adhesive strength and surface adhesive strength are In addition, the effect of maintaining the initial adhesive strength and surface adhesive strength of the pressure-sensitive adhesive layer is enhanced.

  In particular, the pressure-sensitive adhesive used in the present invention is a water-based pressure-sensitive adhesive. Therefore, it is necessary to emulsify when components contained in an adhesive such as an acrylic resin, a crosslinking agent, and a tackifier are not dispersed in water. In the emulsification, a conventionally known emulsifier can be used, and the emulsification method is not particularly limited, and any of the known emulsification methods such as a high pressure emulsification method, an inversion emulsification method, an ultrasonic emulsification method, and a solvent emulsification method. A method may be adopted.

  You may further mix | blend another component with the adhesive of this invention as needed. Examples of other components that can be blended include various conventionally known additives such as plasticizers, softeners, fillers, colorants (pigments, dyes, etc.), antioxidants, and antioxidants.

  The manufacturing method of the water-based adhesive for forming the adhesive layer of this invention is not specifically limited, The adhesive used for this invention can be manufactured by a conventionally well-known method. For example, it can manufacture by throwing each component into a container and mixing it uniformly.

<Base material>
The base material used for this invention is not specifically limited, A conventionally well-known thing can be used. Examples of conventionally known base materials include papers and resin films.

  Furthermore, examples of the paper include cast-coated paper, art paper, coated paper, and high-quality paper. Examples of the resin film include various polymer films such as polypropylene, polyethylene, polyethylene terephthalate, and polyvinyl chloride. Also, vapor-deposited paper, synthetic paper, cloth, nonwoven fabric, metal foil, and the like can be used. These may be used in a single layer or may be used in a stacked manner. Among these, high-quality paper is preferable.

  In order to improve the adhesion to the pressure-sensitive adhesive layer on the surface of the substrate, it is preferable to perform an easy adhesion treatment. This is because if the substrate is peeled off from the pressure-sensitive adhesive layer, it cannot be preferably used as tack paper.

  The manufacturing method of a base material is not specifically limited, It can manufacture by a conventionally well-known general method. For example, it can be manufactured by melting a resin as a material with an extruder, extruding and cooling.

<Release paper>
The release paper that can be used in the present invention is not particularly limited, and conventionally known release papers can be used. Conventionally known release papers include high-grade base papers such as glassine paper, base papers such as clay-coated paper, kraft paper or fine paper, such as casein, dextrin, starch, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, Styrene-butadiene copolymer, ethylene-vinyl chloride copolymer, methyl methacrylate-butadiene copolymer, ethylene-vinyl acetate copolymer, (meth) acrylic acid ester copolymer natural or synthetic resin alone or kaolin , Clay, calcium carbonate, calcined clay (calcined kaolin), base material provided with a sealing layer used in combination with inorganic pigments such as titanium oxide and silica, and organic pigments such as plastic pigment, kraft paper or high quality paper, etc. Laminated synthetic resin To the Porirami paper or the like, after coating a solvent type or solventless type silicone resin or a fluorine resin or the like, obtained by forming a release agent layer by heat curing or electron beam or ultraviolet curing or the like can suitably be used. The apparatus for applying the release agent is not particularly limited. For example, a bar coater, a direct gravure coater, an offset gravure coater, a flexo coater, an air knife coater, a multi-stage roll coater, etc. are appropriately used. .

<Tack paper manufacturing method>
First, an adhesive is applied to the substrate, and an adhesive layer is formed on the surface of the substrate.

  The method for applying the pressure-sensitive adhesive is not particularly limited, and a conventionally known coating method can be used. Specifically, roll coating method, gravure coating method, micro gravure coating method, reverse coating method, roll brush method, spray coating method, air knife coating method, impregnation method, curtain coating method, die coating method, doctor blade The coat which mentions a method, a comma coat method, etc. can be performed. Examples of the method for drying the applied pressure-sensitive adhesive layer include a hot air drying method and an infrared drying method.

The coating amount at the time of applying the adhesive is not particularly limited, the coating amount of the adhesive is preferably from 5 g / m ² is 30 g / m ^2. If the pressure-sensitive adhesive layer is too thin, the initial pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer is lowered, which is not preferable. On the other hand, if the pressure-sensitive adhesive layer is too thick, the initial pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer becomes so high that it is difficult to use it as tack paper. Since the tack paper of the present invention is stable at a high value of the adhesive strength and surface adhesive strength of the adhesive layer, the adhesive layer can be made thin.

  The adhesive strength of the formed pressure-sensitive adhesive layer is not particularly limited and can be appropriately changed according to the article to be attached. However, in order to make a tack paper that is not easily peeled off after being attached to an adherend, the adhesive strength of the adhesive layer is preferably 1,500 gf / 25 mm to 2,500 gf / 25 mm, more preferably 1 , 850 gf / 25 mm to 2,500 gf / 25 mm.

The surface adhesive force of the formed pressure-sensitive adhesive layer is not particularly limited, and can be appropriately changed according to the article to which the tack paper is to be attached in the same manner as the adhesive force. However, in order to obtain a tack paper that does not easily peel off after being applied to an adherend, the surface adhesive strength of the pressure-sensitive adhesive layer is preferably 100 kN / m ² to 250 kN / m ² , more preferably 130 kN / m ^2. m ² to 250 kN / m ² .

  Next, the base material on which the pressure-sensitive adhesive layer is formed and the release paper are bonded together. The method of bonding is not particularly limited, but Roll to Roll is preferable from the viewpoint of increasing production efficiency.

<Physical properties of tack paper>
The tack paper of the present invention has a high initial adhesive strength, an initial surface adhesive strength of the adhesive layer, even if it is stored and left for a long time in a high temperature and high humidity environment, a normal temperature and normal humidity environment, etc.・ The degree of decrease in surface adhesive strength is small, and the adhesive strength and surface adhesive strength of the adhesive layer after long-term storage and storage are stable with little change from the initial adhesive strength and initial surface adhesive strength. Features.

  In particular, the change rate of the adhesive strength and the surface adhesive strength when left at 40 ° C. and a humidity of 90% is preferably −20% to 20% relative to that before being left.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Material>
Acrylic resin: manufactured by Toyo Ink Manufacturing Co., Ltd., trade name “Olivein BPW6111”
Carbodiimide type crosslinking agent: Nisshinbo Co., Ltd., trade name “Carbodilite E-03A”
Epoxy crosslinking agent: Sakamoto Yakuhin Kogyo Co., Ltd., trade name “SR-2EG” dissolved product tackifier 1: Harima Kasei Co., Ltd., trade name “Hari Star SK-370N” (acid value: 58 to 65 KOH mg / g)
Tackifier 2: manufactured by Harima Kasei Co., Ltd., trade name “Harry Star SK-501NS” (acid value: <10 KOH mg / g)

<Manufacture of tack paper>
Implemented by dispersing the materials shown in Tables 1, 3, 5, 7, and 9 in water at a ratio shown in Tables 1, 3, 5, 7, and 9 so that the solid content is 60% and mixing them uniformly. The aqueous adhesives of Examples and Comparative Examples were obtained.

Using a paper separator (trade name “EN64 Shiro P”, manufactured by Lintec Co., Ltd.) as the release paper, the adhesive coating amount after solvent evaporation of the adhesives of Examples and Comparative Examples on the surface of the paper separator was 15 g / m. ^The coating was carried out using an applicator so as to be ² .

  Using high-quality paper (made by Oji Paper Co., Ltd., trade name “OKH <55>”) as a base material, it was bonded to the adhesive layer formed on the paper separator and stored at room temperature for 1 day. And the tack paper of the comparative example was manufactured.

<Evaluation 1>
Immediately after production, after storage for 1 week at room temperature, after storage for 1 month at room temperature (temperature 23 ° C., humidity 50%), the tack papers of Examples and Comparative Examples were cut to a width of 25 mm, the paper separator was peeled off, and JIS Z0237 standard The pressure-sensitive adhesive layer was laminated to SUS304 with a 2 kg roller under the conditions based on the above. Immediately after lamination, the peel strength was measured with a tensile tester (trade name “RTF-1150-H” manufactured by A & D) (tensile condition: speed 300 mm / min, peel angle 180 °). The measurement results are shown in Tables 2, 4, 6, 8, and 10.

  The peel strength was measured in the same manner as described above for the tack papers of Examples and Comparative Examples stored immediately after production and one month after production at 40 ° C. and 90% humidity. The measurement results are shown in Tables 2, 4, 6, 8, and 10.

<Evaluation 2>
Immediately after the production, the surface adhesive strength of the pressure-sensitive adhesive layers of the tack paper of Examples and Comparative Examples stored at room temperature for one month after the production was measured using TAC-II (manufactured by Reska Co.) under the conditions conforming to the standard of JIS Z0237. The measurement conditions are shown below. The measurement results are shown in Tables 2, 4, 6, 8, and 10.
<Measurement conditions>
Probe material: Stainless steel Diameter of probe bottom: 5 mm
Approach speed: 30 mm / min Applied pressure: 10 gf
Pressurization time: 2 seconds Pulling speed: 120 mm / min

  The surface adhesive strength was measured in the same manner as described above for the tack paper of Examples and Comparative Examples stored at 40 ° C. and 90% humidity for 1 month after production. The measurement results are shown in Tables 2, 4, 6, 8, and 10.

<Evaluation 3>
Immediately after the production of the tack papers of Examples and Comparative Examples, after storage for 1 month in a normal temperature and normal humidity environment and in a high temperature and high humidity environment, the adherend (“Diaform N” manufactured by Mitsubishi Paper Industries Co., Ltd.) The peel mode of the adherend was observed when the tack paper immediately after pasting was peeled from the fine paper at a pulling speed of 300 mm / min and a peel angle of 180 °. The observation results are shown in Tables 2, 4, 6, 8, and 10.

  As apparent from Tables 1 to 4, if the content of the crosslinking agent in the pressure-sensitive adhesive layer is 0.30 parts by mass to 1.2 parts by mass with respect to 100 parts by mass of the acrylic resin, (Even when stored at 40 ° C and humidity of 90%) at room temperature and humidity for a month, the initial adhesive strength and initial surface adhesive strength of the adhesive layer are low, and the initial high adhesive strength and surface adhesive strength are low. Was confirmed to be maintained.

  As is apparent from Tables 5 to 8, if the acid value of the tackifier contained in the pressure-sensitive adhesive layer is in the range of 10 KOHmg / g to 100 KOHmg / g, the initial pressure-sensitive adhesive strength and initial surface pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer are high. It was confirmed.

  As is clear from the results of Tables 9 and 10, if the content of the tackifier is 1.0 part by mass to 1.7 parts by mass with respect to 100 parts by mass of the acrylic resin, under a high temperature and high humidity environment (40 Even if it is stored for 1 month in a room temperature and humidity environment, the initial adhesive strength of the adhesive layer and the initial surface adhesive strength are less reduced, and the initial high adhesive strength and surface adhesive strength are maintained. Confirmed to do.

From the above results, it was confirmed that the tack paper of the present invention showed extremely high values such that the initial adhesive strength of the adhesive layer was 1,850 gf / 25 mm or more and the initial surface adhesive strength was 130 kN / m ² or more. And even if it is stored for 1 month in high temperature and high humidity environment (40 ° C humidity 90%) and normal temperature and humidity environment, the change from initial adhesive strength and initial surface adhesive strength is in the range of -20% to + 20%. It was confirmed that the effects of stabilizing adhesive strength and surface adhesive strength were extremely high. Such tack paper showing high adhesive strength and high surface adhesive strength should be peeled off immediately after being attached to high-quality paper, peeled off after storage in a normal temperature and humidity environment, or peeled off after storage in a hot and humid environment. In any case, it was confirmed that the quality paper material was destroyed, and it was confirmed that the tack paper of the above example was not easily peeled off once applied.

Claims (4)

A tack paper in which a release paper is pasted through an adhesive layer formed by applying a water-based adhesive on a substrate,
The aqueous adhesive includes an acrylic resin, a crosslinking agent, and a tackifier mainly composed of an acidic group-containing rosin resin,
The tackifier has an acid value of 10 KOHmg / g to 100 KOHmg / g,
The content of the tackifier is 1.0 part by mass to 1.7 parts by mass with respect to 100 parts by mass of the acrylic resin.
The tack paper has a cross-linking agent content of 0.30 to 1.2 parts by mass with respect to 100 parts by mass of the acrylic resin. The pressure-sensitive adhesive force of the pressure-sensitive adhesive layer in a method according to JIS Z0237 is from 1,850 gf / 25 mm to 2,500 gf / 25 mm,
The tack paper according to claim 1, wherein a probe tack of the pressure-sensitive adhesive layer in a method according to JIS Z0237 is 130 kN / m ² to 250 kN / m ² . The change rate of the adhesive strength of the pressure-sensitive adhesive layer after one month when it was left in an environment of 40 ° C. and 90% humidity for one month was compared with the adhesive strength before leaving. -20% to 20%,
When the adhesive layer is left to stand for one month in an environment of 40 ° C. and humidity of 90%, the change rate of the probe tack in the method according to JIS Z0237 of the pressure-sensitive adhesive layer after one month is The tack paper according to claim 1 or 2, which is -20% to 20%. The peeling the release paper, the adhesive layer, after the basis weight was attached from 64.0 g / ^{m 2} to an adherend made of wood free paper of 157.0 g / ^{m 2,} rate 300 mm / min tensile, peel The tack paper according to any one of claims 1 to 3, wherein the adherend is destroyed when peeled from the adherend at an angle of 180 °.