JP2005232390A - Pressure sensitive adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive, capable of easily performing position-setting for pasting on a desired pasting position on the surface of a substrate to be pasted on pasting a tape, film, sheet, sticker, etc., having an adhesive function on the surface of the substrate to be pasted, also capable of correctively transferring to the desired pasted position as necessary, and capable of recognizing whether the corrective transfer to the desired pasting position is possible or not, and the adhesive is pasted or not by a sound generated from the adhesive, and performing the adhesive function after the completion of position setting. <P>SOLUTION: This pressure-sensitive adhesive 1 is provided by dispersing microcapsules 10 containing an aqueous adhesive 12 and releasing the included substance on being broken or crushed by adding outside force, and a water soluble substance 20 sealing high pressure gas 22 as a bubble state within a re-peelable adhesive 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive used for tapes, films, sheets, stickers and the like, and relates to a pressure-sensitive adhesive that changes from a temporarily fixed state to a permanently bonded state.

  Conventionally, when adhering to the surface of the substrate to be adhered in a tape, film, sheet, sticker or the like having an adhesive function, it is easy to align the surface of the substrate to be adhered to a desired adhesion site, and Moreover, the proposal which enables the correction movement to the said desired sticking site | part as needed was made | formed. Adhesives used for these tapes, films, sheets, stickers, etc. are difficult to adhere to the desired site on the surface of the substrate to be adhered, and the initial adhesive strength is large. The above proposal has been made to solve these problems because deformation, fracture, wrinkles, and the like occur.

  For example, Patent Document 1 proposes to microencapsulate an adhesive component in a non-adhesive shell. However, in this proposal, since the shell is not sticky, there is a problem that it is difficult to fix the shell to a desired sticking site and destroy the microcapsule.

  Patent Document 2 proposes a pressure-sensitive adhesive layer characterized in that the adhesive layer has small, fragile or collapsible non-adhesive protrusions that are uniformly distributed on at least one surface thereof. According to this proposal, non-adhesive hollow microballoons that are friable or collapsible, such as hollow microballoons or hollow glass microballoons of resins such as urea-formaldehyde resin, are attached to at least one of the adhesive layers. It was distributed uniformly on the surface to reduce the initial adhesive force, and the adhesive force of the adhesive layer was developed by rupturing or collapsing the hollow microballoons during pressure bonding to the adherend substrate. However, in this proposal, there is a problem in that it is difficult to confirm that the hollow microballoon has been ruptured or crushed when it is pressure-bonded to the substrate to be bonded. As a result, is it possible to correct the movement to the desired bonding site? There is a problem that it is difficult for the adhesive user to know whether the hollow balloon is ruptured or crushed when the pressure is applied, and in what state the hollow balloon is ruptured or crushed. It was. Therefore, when the user actually uses it, it has been necessary to confirm whether or not the correction movement to the desired sticking site is possible by actually performing the correction movement.

  On the other hand, Patent Document 3 and the like disclose a high-pressure gas-filled candy that is a hard candy composition encapsulating high-pressure carbon dioxide gas, and that can be eaten while being released with a pleasant sound when dissolved in the oral cavity. Yes. According to Patent Document 3 and the like, a method for introducing a high-pressure gas is known in the food field, but there is no technology that uses these techniques as an adhesive.

Japanese Patent Laid-Open No. 2-102280 Japanese Patent Publication No.44-3120 Japanese Patent Publication No.57-39151

  Therefore, when the present invention is bonded to the surface of the substrate to be bonded in a tape, film, sheet, sticker or the like having an adhesive function, the bonding position alignment to a desired bonding site on the surface of the substrate to be bonded is performed. In addition, it is possible to make correction movement to a desired application site as necessary, and to determine whether or not correction movement to a desired application site is possible and whether or not the application has been applied. It is an object of the present invention to provide a pressure-sensitive adhesive that can be recognized by a sound that is emitted and that performs an adhesive function after completion of alignment.

  Moreover, this invention makes it a subject to provide the pressure sensitive adhesive which can recognize by the sound emitted from an adhesive agent whether the correction movement to a desired sticking site | part is possible or not.

  As a result of intensive studies to solve the above problems, it was found that a water-soluble substance containing high-pressure gas in the form of bubbles dissolves in the water in the water-based adhesive and emits sound. Therefore, the water-based adhesive is encapsulated in the microcapsule, and the adhesive-encapsulated microcapsule and the water-soluble substance in which the high-pressure gas is encapsulated in the form of bubbles are dispersed in a releasable adhesive with low initial adhesiveness, In the state where pressure bonding is not performed, only the releasable adhesive works, so correction movement to the desired bonding site on the surface of the substrate to be bonded is possible. When the water-based adhesive is destroyed or crushed, the adhesive function is performed, and at the same time, the high-pressure gas-encapsulated water-soluble substance dissolves in the water in the water-based adhesive and emits a sound that can be corrected. We found that changes that could not be made at a certain time could be pressure-sensitive adhesives that can be recognized by sound, and completed the present invention.

  That is, the present application includes the following first and second pressure-sensitive adhesives. The first pressure-sensitive adhesive of the present invention is characterized by containing microcapsules encapsulating a water-based adhesive and a water-soluble substance containing high-pressure gas in the form of bubbles as essential components. The microcapsules are preferably those that can be broken or crushed by applying an external force to release the inclusions.

  When the first pressure-sensitive adhesive disperses the microcapsules encapsulating the water-based adhesive having a large initial adhesive force in a re-peelable adhesive, temporarily fixes it to the desired sticking site, and when correction movement is required It is possible to correct the movement of the sticking part, and also to allow permanent adhesion by the action of breaking or crushing the microcapsule, and whether the action of breaking or crushing the microcapsule is possible, that is, the sticking part can be corrected and moved. It is solved by recognizing whether or not it is possible by sound. In other words, in the state where external force such as shearing force is not applied (to the extent that it can be lightly bonded), only the adhesive with a small initial adhesiveness works, so correction movement such as reattachment is possible. Pressure sensitive adhesive that can recognize changes that cannot be re-attached by sound because the water-based adhesive performs a bonding function when it is crushed, and the water-soluble substance in the high-pressure gas dissolves in the water in the water-based adhesive and emits sound. It makes the agent possible. The microcapsule is attached without being destroyed by the transfer pressure when used for a transfer tape or the like, and is not destroyed even when the movement is corrected, but is adjusted to a strength that is destroyed when the pressure is applied.

  The second pressure-sensitive adhesive of the present invention essentially comprises at least microcapsules that can be broken or crushed by applying external force and release the inclusions, and a water-soluble substance that contains high-pressure gas in the form of bubbles. It is contained as a component. Because it contains a microcapsule that encloses water and a water-soluble substance in which high-pressure gas is contained in the form of bubbles, the water released from the microcapsule destroyed or crushed by an external force such as shearing force As the substance dissolves, the high-pressure gas can bounce and make a sound.

As described above, the effects of the present invention are as follows.
1) In the state where pressure bonding is not performed, since only the releasable adhesive works, correction movement to the desired bonding site on the surface of the substrate to be bonded is possible, and pressure is applied by applying an external force such as shearing force. The microcapsules are broken or crushed and the water-based adhesive is released to perform the adhesive function.

2) When the microcapsules are broken or crushed and the water-based adhesive is released, it performs an adhesive function, and at the same time, the high-pressure gas-encapsulated water-soluble substance dissolves in the water in the water-based adhesive and emits a sound that can be played. Changes that become impossible from the time when movement is possible can be recognized by sound.

3) It is possible to provide a pressure-sensitive adhesive in which a high-pressure gas-encapsulated water-soluble substance dissolves in water released from microcapsules destroyed or crushed by an external force, so that high-pressure gas can be repelled and sound can be generated.

  The present invention will be described in detail below. The first pressure-sensitive adhesive of the present invention is essentially composed of a microcapsule encapsulating a water-based adhesive and a water-soluble substance containing high-pressure gas in the form of bubbles (hereinafter referred to as “high-pressure gas-encapsulated water-soluble substance”). Is included. The first pressure-sensitive adhesive can correct the movement of the application site, and by applying external force and pressing it, the microcapsule is destroyed or crushed, and the water-based adhesive is released to perform the adhesive function. Alternatively, the water-based adhesive released from the crushed microcapsules dissolves the high-pressure gas-enclosed water-soluble substance, so that the high-pressure gas repels and emits sound.

  In order to obtain the first pressure-sensitive adhesive, it is preferable to disperse a microcapsule encapsulating a water-based adhesive and a high-pressure gas-sealed water-soluble substance in a re-peelable pressure-sensitive adhesive. For dispersion, a dispersant or the like may be appropriately used. The compounding amount of the microcapsules in the pressure-sensitive adhesive is preferably 30 to 120 parts by weight, more preferably 40 to 90 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive. When the blending amount is less than 30 parts by weight, the adhesiveness is insufficient, and when it exceeds 120 parts by weight, it becomes difficult to disperse the microcapsules into the pressure-sensitive adhesive. Moreover, it is preferable to set it as 5-40 weight part with respect to 100 weight part of adhesives, More preferably, it is 10-35 weight part with respect to 100 weight part of adhesives. If it is less than 5 parts by weight, it is difficult to recognize by sound. If it exceeds 40 parts by weight, the adhesiveness after pressure bonding becomes insufficient.

  When the adhesive strength of the pressure-sensitive adhesive is high, correction movement to a desired sticking site cannot be performed when sticking to the surface of the sticking substrate. Accordingly, the adhesive strength of the adhesive is suitably in the range of 10 to 1000 g / 25 mm (SUS), more preferably 10 to 500 g / 25 mm (SUS), according to the test method of JIS Z 0237.

  In addition, if the water-soluble substance containing the high-pressure gas in the form of bubbles is dissolved when dispersed in the re-peelable pressure-sensitive adhesive, the present invention will not achieve its purpose. A non-aqueous pressure-sensitive adhesive that is incompatible with a water-soluble substance in which high-pressure gas is contained in the form of bubbles is suitable. Therefore, a commercially available pressure-sensitive adhesive can be used as the re-peelable pressure-sensitive adhesive if it is non-aqueous. Specific examples include, for example, rubber adhesives such as natural rubber and synthetic rubber, acrylic adhesives such as acrylic ester (co) polymers, vinyl acetate / acrylic ester copolymers, urethane adhesives, and silicone adhesives. An agent etc. can be mentioned. Among these non-aqueous pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferable.

  In order to achieve the object of the present invention, the high-pressure gas-sealed water-soluble substance must be dissolved in the aqueous adhesive contained in the microcapsule. In order to achieve the object of the present invention, the amount of water contained in the microcapsule is preferably not less than the same weight as the high-pressure gas-enclosed water-soluble substance, more preferably about 2 to 10 times. Is desirable. If the amount of water contained in the water-based adhesive is less than the same weight as the high-pressure gas-filled water-soluble material, it becomes difficult to dissolve the water-soluble material, while if it exceeds 10 times the amount, the substrate to be adhered is paper or the like. Will become wrinkles when bonded. From this point of view, the aqueous adhesive contained in the microcapsule is not limited in form and type as long as it contains a sufficient amount of water to dissolve the high-pressure gas-encapsulated water-soluble substance and has sufficient adhesive strength. Can be used. For example, an aqueous solution of an adhesive water-soluble polymer or an aqueous emulsion adhesive may be used. The microcapsules may contain additives such as surfactants and viscosity modifiers used during production.

  Here, examples of the water-soluble polymer include polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP). Examples of the water-based emulsion adhesive include vinyl acetate emulsion, vinyl acetate / acrylic emulsion, and acrylic emulsion. Among water-based adhesives, water-based emulsion type adhesives are preferably used because of their good adhesion.

  The above water-based emulsion type adhesive may be used in combination with two types of emulsions in order to adjust the adhesive strength. For example, the initial adhesive force can be increased by using an acrylic emulsion having a low Tg and a vinyl acetate emulsion having a strong adhesive force. Similarly, an adhesive water-soluble polymer such as polyvinyl pyrrolidone or polyvinyl alcohol can also be used as an adhesion aid. The main agent is at least one adhesive such as vinyl acetate emulsion or acrylic emulsion such as Aika Ivon series (Aika Industry Co., Ltd.), Nicazole series (Nippon Carbide Industry Co., Ltd.), Movinyl series (Clariant Polymer Co., Ltd.), etc. Seeds can be used.

  The adhesive strength of the water-based adhesive varies depending on the type of the substrate to be adhered, but the adhesive strength value according to the test method of JIS Z 0237 is preferably 1000 g / 25 mm (SUS) or more, more preferably 1500 to 2500 g / The range is 25 mm (SUS).

  The material of the wall material of the microcapsule is not compatible with the pressure-sensitive adhesive because the object of the present invention cannot be achieved if the microcapsule dissolves when dispersed in the removable adhesive (non-aqueous pressure-sensitive adhesive). A material that does not melt and that has little influence on the adhesive force even after the microcapsules are broken or crushed is desirable. Examples of the wall material include urethane resin, phenol formaldehyde resin, styrene resin, acrylic resin, vinyl acetate resin, epoxy resin, gelatin, and the like, and a crosslinking agent may be appropriately added.

  The size of the microcapsules is preferably 1 to 300 μm, particularly 5 to 100 μm. If the size of the microcapsule is less than 1 μm, it is difficult to break or crush, and if it exceeds 300 μm, it is difficult to disperse in the adhesive.

  A microcapsule containing an aqueous adhesive can be obtained by using a microcapsule preparation method such as an in-situ polymerization method, an interfacial polymerization method, a submerged curing method, a coacervation method, or a submerged drying method. . Among these preparation methods, the interfacial polymerization method and the submerged curing method are preferable in terms of the state and strength of the resulting microcapsule wall. In other words, there is little leakage of inclusions at the time of manufacture, the inclusion water does not volatilize over time, it is stable, it is stuck without being destroyed by transfer pressure, and it is not destroyed even when moving, but it is destroyed when crimping It is excellent in that it can maintain the strength.

  Here, interfacial polymerization is a method in which a substance to be encapsulated in microcapsules is dissolved or dispersed in a dispersed phase, and two or more kinds of microcapsule wall forming substances are supplied from the continuous phase side and the other from the dispersed phase side. In this method, a microcapsule wall is formed by reacting at the interface between both phases. In the liquid curing method, a polymer solution containing what is to be encapsulated in a microcapsule is dispersed in a continuous phase that is not compatible with the solution to form droplets, and the polymer is insolubilized with a curing agent or a crosslinking agent. A capsule wall.

  When the microcapsules used in the present invention are produced by the interfacial polymerization method, first, an aqueous adhesive is dissolved or dispersed in an aqueous phase, and this is dispersed in an oil phase containing a microcapsule wall-forming substance to form a W / O emulsion. The emulsion is dispersed in an aqueous phase of 1.5 to 20 times by weight (preferably 2.5 to 10 times by weight) to obtain a W / O / W type emulsion. It is preferable to add a curing agent that reacts with the forming substance to form the capsule wall and cure by reaction. The ratio of the water phase to the oil phase in the W / O emulsion is preferably water phase / oil phase = 10/90 to 70/30 (weight ratio), and 15/85 to 65/35 (weight ratio). More preferably. The reaction temperature is preferably from 0 ° C to 60 ° C. When the reaction temperature is less than 0 ° C, the reaction rate is slow, and when it exceeds 60 ° C, a dense capsule wall is hardly formed.

  Examples of the microcapsule wall-forming substance contained in the oil phase include isocyanates, such as hexamethylene diisocyanate, metaphenylene diisocyanate, toluylene isocyanate, 2,4-tolylene diisocyanate, toluylene isocyanate and trimethylolpropane. Reaction products, isocyanate monomers such as 3,3-dimethyldiphenyl-4,4-diisocyanate, diphenylmethane-4,4-diisocyanate, triphenylmethane triisocyanate, naphthalene-1,5-diisocyanate, modified or derivatives of isocyanate, etc. What forms a polyurethane wall can be used. As the interfacial polymerization method, a polyamide capsule wall can be formed by using acid chloride, sebacoyl chloride, or terephthalic acid chloride, but polyurethane is more preferable in terms of capsule strength and hardness.

  The solvent used for the oil phase is preferably a non-aqueous solvent that is incompatible with water. If the reaction solvent remains in the capsule, the adhesive force after the capsule breakage does not appear, so the solvent is volatilized and collected after the capsule wall is formed. Therefore, it is preferable that the solvent has a low boiling point, and those having a boiling point of 35 ° C. to 90 ° C. are suitably used. Examples of such a solvent include hexane, isohexane, 3-methylpentane, neohexane, 2,3-dimethylbutane, cyclopentane, cyclohexane, chloroform, diethyl ether, ethyl acetate, and methyl ethyl ketone. These solvents may be used alone, or two or more kinds may be mixed and used in an arbitrary ratio.

  A surfactant and a viscosity modifier may be added when forming the W / O emulsion and / or the W / O / W emulsion. The addition amount of the surfactant is 1 to 50% by weight, preferably 5 to 30% by weight, based on the whole emulsion. The surfactant is preferably HLB 7 or less, more preferably HLB 4 or less. Examples of the surfactant include propylene glycol stearate such as propylene glycol monostearate, glyceryl fatty acid ester such as glyceryl monomyristate, glyceryl monostearate, glyceryl monooleate, and glyceryl monoisostearate, and tristearic acid. Examples include sorbitan fatty acid esters such as sorbitan, sorbitan sesquioleate and sorbitan trioleate, and polyoxyethylene sorbite fatty acid esters such as hexastearic acid POE (6) sorbit. These surfactants may be used alone or in combination of two or more at any ratio.

  Although the hardening | curing agent used for polyurethane wall formation is not specifically limited, Amin is mentioned as a representative example. The amine may be used in a ratio of amine group to NCO group of isocyanate in the range of 1: 1 to 1: 7, preferably 1: 2 to 1: 7. Examples of amines include stearylamine, oleylamine, dodecylamine, ethylenediamine, 1,3-propylenediamine, diethylenetriamine, triethylenetetramine, 1,6-hexamethylenediamine, and other aliphatic amines, xylenediamine, and N-aminopropylpimine. Examples thereof include amines having a cyclic structure such as verazine.

  After completion of the curing reaction, the solvent in the microcapsules is volatilized by heating at a temperature of 80 ° C. or lower, or by heating at a lower temperature under reduced pressure. After the solvent is volatilized, the microcapsule is separated from the solution and dried to obtain a microcapsule containing an aqueous adhesive.

  The high-pressure sealed water-soluble substance is obtained by enclosing a high-pressure gas such as carbon dioxide in a water-soluble substance in the form of bubbles, and is manufactured according to a method for manufacturing a high-pressure gas-filled candy or the like. Specifically, a water-soluble substance heated and melted is stored in a pressurized container, and then a gas for sealing is introduced into the container and pressurized, and at the same time, bubbles are formed in the molten water-soluble substance by heating and stirring. A method of containing and cooling and solidifying it (JP-A-52-44268), forming a high-pressure gas bubble in the water-soluble substance by heating and melting the water-soluble substance in the first pressure vessel and stirring. And this is poured into a second pressurized container and cooled and solidified (Japanese Patent Laid-Open Nos. 52-44269 and 53-6462). The water-soluble substance for enclosing high-pressure gas that can be used in the present invention is not particularly limited, and examples thereof include sugars such as sugar, glucose, lactose, and starch syrup.

  The size of the water-soluble substance in which the high-pressure gas is sealed in the form of bubbles is preferably 1 to 300 μm, particularly 5 to 100 μm. When the size of the high-pressure gas-encapsulated water-soluble substance is less than 1 μm, it cannot be encapsulated to such an extent that the high-pressure gas is repelled and sound is generated, whereas when it exceeds 300 μm, it is difficult to disperse in the adhesive.

  The second pressure-sensitive adhesive of the present invention comprises a microcapsule that can be broken or crushed by applying external force and containing at least water, and a high-pressure gas used in the first pressure-sensitive adhesive. And a water-soluble substance encapsulated in the form of an essential component. The microcapsule is a microcapsule encapsulating the aqueous adhesive described above, in which water is encapsulated in the wall material instead of the aqueous adhesive, and is produced according to the method for producing the microencapsulated adhesive described above. be able to. In order to achieve the object of the present invention, the amount of water contained in the microcapsule is preferably not less than the same weight as the high-pressure gas-enclosed water-soluble substance, more preferably about 2 to 10 times. Is desirable. If the amount of water contained in the water-based adhesive is less than the same weight as the high-pressure gas-filled water-soluble material, it becomes difficult to dissolve the water-soluble material, while if it exceeds 10 times the amount, the substrate to be adhered is paper or the like. Will become wrinkles when bonded.

  FIG. 1 is a schematic cross-sectional view showing the working mechanism of the pressure-sensitive adhesive of the present invention. FIG. 1 schematically shows an embodiment of the present invention, and the present invention is not limited to this embodiment. In FIG. 1, 1 is a pressure-sensitive adhesive, and 2 is an adherend substrate such as paper or plastic. 10 is a water-based adhesive-encapsulated microcapsule, 11 is a wall material, 12 is an adhesive (polymer), 13 is water, 20 is a high-pressure gas-filled water-soluble substance, 21 is a water-soluble substance, 22 is a high-pressure gas, and 30 is re-peeling It is a possible adhesive.

  In FIG. 1A, an aqueous adhesive-encapsulated microcapsule 10 and a high-pressure gas-sealed water-soluble substance 20 are dispersed in an adhesive 30. When an external force such as a shearing force is applied, the microcapsule 10 is broken or crushed (FIG. 1B), the water 13 contained in the microcapsule is released, and the high-pressure gas-filled water-soluble substance 21 is removed. Dissolve (FIG. 1 (c)). Next, the water-soluble substance 21 dissolves and the high-pressure gas 22 repels and emits sound. At the same time, the adhesive 12 is mixed in the pressure-sensitive adhesive 30 and thus has a strong adhesive force (FIG. 1). (D)).

  The pressure-sensitive adhesive of the present invention can be used for applications in which a pressure-sensitive adhesive is used, such as a tape, a film, a sheet, and a sticker.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only the following Examples. In each example, parts and percentages are by weight unless otherwise specified.

Production Example 1 (Preparation of water-based adhesive-encapsulated microcapsules)
In 30.0 parts of a mixed solvent of ethyl acetate and cyclopentane, 7.0 parts of a reaction product of 75 parts of toluylene isocyanate and trimethylolpropane dispersed in 100 parts of ethyl acetate was dissolved, and Span 80 was added to 3.0 parts. The part was melted. A solution obtained by adding 3.0 parts of a 5% aqueous solution of polyvinyl alcohol to 9.0 parts of an aqueous emulsion pressure-sensitive adhesive Nicazole TS2002 (manufactured by Nippon Carbide Industries Co., Ltd., acrylic resin emulsion; solid content 60%) at 3000 rpm, 5 Dispersion was carried out using a minute disper to prepare dispersion A (W / O type). Separately, an aqueous solution B was prepared by adding 150 parts of water to 150 parts of a 5% aqueous solution of polyvinyl alcohol. Dispersion A was added to this aqueous solution B and dispersed at 3000 rpm for 5 minutes to obtain dispersion C (W / O / W type). A solution obtained by dissolving 4.97 g of 1,6-hexanediamine in 10 g of water was added to Dispersion C, and the mixture was heated at 55 ° C. for 2 hr with gentle stirring, and further heated at 80 ° C. for 1 hr. The product was filtered, and water-based adhesive-encapsulated microcapsules (average particle size 25 μm) were taken out.

Production Example 2 (Preparation of water-based adhesive-encapsulated microcapsules)
A solution obtained by dispersing 6.0 parts of PVP 20% aqueous solution, aqueous adhesive Nicazole TS1537 (manufactured by Nippon Carbide Industries Co., Ltd., acrylic resin emulsion; solid content 55%), 0.02 parts of Tween 20 with chloroform Disperse in 30.0 parts of a mixed solvent of isohexane, 3.0 parts of dimethicone copolyol and 6.5 parts of a two-component polyisocyanate resin (Takenate D-103H) to obtain dispersion D (W / O type) ). Dispersion D was dispersed in 300.0 g of water in which 2.0 parts of a viscosity modifier was dissolved to prepare a dispersion (W / O / W type). To the dispersion, 2.49 parts of 1,6-hexanediamine was added, and the dispersion was heated to 65 ° C. and stirred for 3 hours, followed by filtration, and the resulting microcapsules (average particle size 50 μm) were taken out.

Production Example 3 (Preparation of water-containing microcapsules)
Glycerol in 9.0 parts of water was dissolved in 7.0 parts of polyurethane resin Vernock D-990 (Dainippon Ink & Chemicals, Inc.) and 2.5 parts of Span 85 in 30.0 parts of a mixed solvent of ethyl acetate and isohexane. What added 3.0 parts was disperse | distributed with the dissolver. This dispersion was added to a solution of 8.0 g of CMC dissolved in 400 g of water, stirred, and 10 g of a 10% NaOH aqueous solution was added little by little. The dispersion was stirred for 2 hours while being heated to 65 ° C., further heated to 80 ° C., and stirring was continued for 30 minutes. The product was filtered, and water-encapsulated microcapsules (average particle size 40 μm) were taken out.

(Preparation of pressure-sensitive adhesive)
Two parts of the crosslinking agent CK-101 was added to 200 parts of the non-aqueous acrylic pressure-sensitive adhesive Nisset KP-1420 (manufactured by Nippon Carbide Industries Co., Ltd.), 100 parts of the aqueous adhesive-encapsulated microcapsules obtained in Production Example 2, and carbon dioxide high pressure A pressure-sensitive adhesive was prepared by stirring and dispersing 15 parts of a water-soluble substance powder (particle size: about 90 μm) mainly composed of saccharide containing gas in a bubble form.

  The pressure-sensitive adhesive was coated on release paper so that the thickness after drying was 100 μm and processed into a tape shape. This pressure-sensitive adhesive tape was transferred to a high quality paper, and the high quality paper was attached to confirm the effect. As a result, as shown in Table 1 below, the initial adhesive force was sufficiently small and the movement on the adherend was sufficiently possible. However, when sound was generated from the pressure-sensitive adhesive tape by pressure bonding, It became possible to recognize the change from the time when this correction movement was possible to the time when it was impossible to recognize by sound. Moreover, the movement of the sticking part cannot be corrected, and when trying to move forcibly, the quality paper is destroyed.

(Preparation of pressure-sensitive adhesive)
Two parts of the crosslinking agent CK-101 were added to 200 parts of the non-aqueous acrylic pressure-sensitive adhesive Nisset KP-1420 (manufactured by Nippon Carbide Industries Co., Ltd.), 100 parts of the aqueous adhesive-encapsulated microcapsules obtained in Production Example 1, and carbon dioxide high pressure A pressure-sensitive adhesive was prepared by stirring and dispersing 15 parts of a water-soluble substance powder (particle size: about 90 μm) mainly composed of saccharide containing gas in a bubble form.

  The pressure-sensitive adhesive was coated on release paper so that the thickness after drying was 100 μm and processed into a tape shape. This pressure-sensitive adhesive tape was transferred to a high quality paper, and the high quality paper was attached to confirm the effect. As a result, as shown in Table 1 below, the initial adhesive force was sufficiently small and the movement on the adherend was sufficiently possible. However, when sound was generated from the pressure-sensitive adhesive tape by pressure bonding, It became possible to recognize the change from the time when this correction movement was possible to the time when it was impossible to recognize by sound. Moreover, the movement of the sticking part cannot be corrected, and when trying to move forcibly, the quality paper is destroyed.

(Preparation of pressure-sensitive adhesive)
1.5 parts of the crosslinking agent CK-103 was added to 200 parts of the non-aqueous acrylic pressure-sensitive adhesive Nisset KP-1410 (manufactured by Nippon Carbide Industries Co., Ltd.), 100 parts of water-encapsulated microcapsules obtained in Production Example 3, and carbon dioxide high-pressure gas 15 parts of a water-soluble substance powder (particle size: about 90 μm) mainly composed of saccharide encapsulated in bubbles was stirred and dispersed to obtain a pressure-sensitive adhesive.

  The pressure-sensitive adhesive was coated on release paper so that the thickness after drying was 80 μm, and processed into a tape shape. This pressure-sensitive adhesive tape was transferred to a high quality paper, and the high quality paper was attached to confirm the effect. As a result, it is possible to move on the adherend as shown in Table 1 below, and when sound is generated from the pressure-sensitive adhesive tape by pressure bonding, the adhesive force is slightly increased. It was possible to recognize the change to an impossible time by sound. Moreover, when it tried to move a sticking site | part, the adhesive surface remained in the paper surface.

(Comparative Example 1)
200 parts of non-aqueous acrylic adhesive NISSETSU PE-115E (manufactured by Nippon Carbide Industries Co., Ltd.), 2 parts of cross-linking agent CK-101 added and stirred, coated on release paper so that the thickness after drying is 50 μm And processed into a tape shape. About this pressure-sensitive adhesive tape, the tape was transferred to a high-quality paper, and the high-quality paper was bonded together to test its effect. As a result, as shown in Table 1 below, the initial adhesive force was large, the movement on the adherend was not possible at all, and the correction movement of the sticking site was impossible.

(Comparative Example 2)
Add 200 parts of the cross-linking agent CK-103 to 200 parts of the non-aqueous acrylic adhesive Nisset KP-1410 (manufactured by Nippon Carbide Industries Co., Ltd.) and stir it on the release paper so that the thickness after drying becomes 100 μm. Coated and processed into a tape. About this pressure-sensitive adhesive tape, the tape was transferred to a high-quality paper, and the high-quality paper was bonded together to test its effect. As a result, as shown in Table 1 below, the initial adhesive force is small, and movement on the adherend is possible, but it is still possible to be peeled after pressure bonding, and the high-quality paper is completely adhered. Was impossible.

The evaluation criteria for the pressure sensitive adhesive shown in Table 1 were as follows. In addition, the numerical value in the parenthesis in the table is a value of adhesive strength (unit: g / 25 mm (SUS)) according to the test method of JIS Z 0237.
(1) Adhesive state before crimping ○: Removable and can move without leaving glue on the paper surface ×: Initial adhesive force is large and cannot be removed again (2) Adhesive state after crimping ○: Unreleasable, unreasonably Strong adhesion that destroys the paper when attempting to move ×: state that peels off without adhesion

It is a cross-sectional schematic diagram which shows one Embodiment of the pressure sensitive adhesive of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure sensitive adhesive 2 Substrate to be bonded 10 Water-based adhesive inclusion microcapsule 11 Wall material 12 Water-based adhesive 13 Water 20 High-pressure gas-enclosed water-soluble substance 21 Water-soluble substance 22 High-pressure gas (carbon dioxide)
30 Removable adhesive

Claims (3)

A pressure-sensitive adhesive comprising, as essential components, a microcapsule encapsulating a water-based adhesive and a water-soluble substance in which high-pressure gas is encapsulated in the form of bubbles. The pressure-sensitive adhesive according to claim 1, wherein the microcapsules can be broken or crushed by applying external force to release inclusions. A pressure-sensitive adhesive comprising, as essential components, a microcapsule that can be broken or crushed by applying external force and containing water, and a water-soluble substance containing high-pressure gas in the form of bubbles. Agent.

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