JP4757344B2 - Bubble-containing viscoelastic composition and pressure-sensitive adhesive tape or sheet - Google Patents

Description

  The present invention relates to a bubble-containing viscoelastic composition having hollow microspheres, and more specifically, a viscoelastic composition that can be used as a pressure-sensitive adhesive layer or substrate having a cell structure and hollow microspheres, and The present invention relates to a pressure-sensitive adhesive tape or sheet using the viscoelastic composition.

  The pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer having a hollow microsphere or a cell structure as a pressure-sensitive adhesive tape or sheet has a cohesive strength, workability, and repulsion resistance when adhered to a curved surface or an uneven surface. It is often used in applications that require safety. As such a pressure-sensitive adhesive tape or sheet, one in which glass microbubbles are dispersed throughout the pressure-sensitive adhesive layer has been proposed (see Patent Document 1). However, glass microbubbles and pressure-sensitive adhesive are proposed. Since the adhesiveness between the polymers in the layer was high, there was no stress dispersibility with respect to the deformation of the pressure-sensitive adhesive tape, and the followability to the uneven surface and the adhesive strength were poor. In order to reduce the adhesion between the glass microbubbles and the polymer in the pressure-sensitive adhesive layer, a pressure-sensitive adhesive tape to which a fluorine-based surfactant or a silicon-based surfactant is added has been proposed (see Patent Document 2). Yes. However, sufficient adhesion cannot be obtained by simply adding a fluorine-based surfactant or a silicon-based surfactant.

Japanese Patent Publication No.57-17030 Japanese Unexamined Patent Publication No. 7-48549

  An object of the present invention is to provide a bubble-containing viscoelastic composition having hollow microspheres that is excellent in cohesive strength, resilience resistance, and adhesive strength. Another object of the present invention is to provide a pressure-sensitive adhesive tape or sheet excellent in cohesive strength, resilience resistance and processability, using the viscoelastic composition as a pressure-sensitive adhesive layer or a substrate.

  As a result of intensive studies to achieve the above object, the present inventors have determined that the use of a surfactant having a specific structure in the molecule allows the hollow microspheres and the polymer in the pressure-sensitive adhesive layer. Adhesiveness and friction between them are reduced, and high stress dispersibility is obtained, thereby realizing cohesive strength of the viscoelastic composition and good followability to the uneven surface at the same time, and excellent repulsion resistance and adhesive strength The inventors have found that a pressure-sensitive adhesive layer can be formed and completed the present invention.

That is, the present invention contains an acrylic polymer having 1 to 20 carbon atoms (meth) acrylic acid alkyl ester of 60% by weight or more based on the total amount of monomer components constituting the polymer, bubbles and hollow microspheres, and a viscoelastic composition comprising a surfactant, wherein the surfactant having an oxy- (C _2-3) alkylene group and a fluorinated hydrocarbon group in the molecule, a fluorine-based weight average molecular weight of 500 to less than 20000 A surfactant and a fluorosurfactant having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group in the molecule and having a weight average molecular weight of 20,000 to 100,000 are in a ratio of 7 to 30: 1 (weight ratio). It is a bubble-containing viscoelastic composition characterized by using together .

  The proportion of the fluorosurfactant is preferably 0.01 to 5 parts by weight (solid content) with respect to 100 parts by weight of the base polymer in the viscoelastic composition.

The hollow microsphere used in the bubble-containing viscoelastic composition of the present invention preferably has a specific gravity of 0.12 to 0.8 g / cm ³ , and a hollow glass balloon is preferred.

  As content of a hollow microsphere, it is preferable that it is 5-50 volume% with respect to the whole volume of the bubble-containing viscoelastic layer formed with the bubble-containing viscoelastic composition.

  The content of the bubbles mixed in the bubble-containing viscoelastic composition of the present invention is preferably 5 to 50% by volume with respect to the total volume of the bubble-containing viscoelastic composition.

  The bubble-containing viscoelastic composition of the present invention is preferably curable with an active energy ray.

  The bubble-containing viscoelastic composition of the present invention can be used as a pressure-sensitive adhesive layer or a substrate.

  The present invention is also a pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed of the bubble-containing viscoelastic composition. A pressure sensitive adhesive tape or sheet.

The present invention is also a pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer on at least one surface of a substrate, wherein the substrate is formed of the bubble-containing viscoelastic composition. A pressure-sensitive adhesive tape or sheet. In addition to the above-described invention, the present specification includes a viscoelastic composition containing bubbles and hollow microspheres and containing a surfactant, wherein the surfactant contains oxy-C _2- A bubble-containing viscoelastic composition characterized by being a fluorosurfactant having ₃ alkylene groups and fluorinated hydrocarbon groups is also described.

  According to the bubble-containing viscoelastic composition having hollow microspheres of the present invention, the pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer in the pressure-sensitive adhesive tape or sheet that simultaneously realizes the cohesive strength and the followability to the uneven surface, and has a good adhesive force. It is possible to form a substrate. Moreover, the pressure-sensitive adhesive tape or sheet produced using the bubble-containing viscoelastic composition can exhibit excellent processability, cohesive strength, and resilience resistance.

It is a schematic sectional drawing which shows partially the example of the pressure sensitive adhesive tape or sheet | seat of this invention. It is a schematic sectional drawing which shows partially the example of the pressure sensitive adhesive tape or sheet | seat of this invention. It is the schematic which shows the opening test in the evaluation method of the resilience resistance concerning an Example.

(Bubble-containing viscoelastic composition)
The bubble-containing viscoelastic composition of the present invention contains a fluorinated surfactant containing bubbles and hollow microspheres, and having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group in the molecule. Adhesion between the hollow microspheres and the polymer in the viscoelastic composition is reduced by using a fluorosurfactant having the structure in the molecule, stress dispersibility is exhibited, and followability to curved surfaces and uneven surfaces , Adhesion performance is improved.

  The amount of bubbles that can be mixed with the bubble-containing viscoelastic composition can be appropriately selected within a range that does not impair the adhesive properties and the like. Volume%, more preferably 12 to 30 volume%). When the amount of bubbles is less than 5% by volume, it is difficult to obtain stress relaxation properties, and the resilience resistance is often poor. On the other hand, if it exceeds 50% by volume, bubbles penetrating the sheet are formed, the adhesiveness is inferior, the bubble-containing viscoelastic composition layer becomes too soft, and the shearing force is often inferior.

  It is desirable that the bubbles mixed in the bubble-containing viscoelastic composition are basically closed-cell type bubbles, but closed-cell type bubbles and open-cell type bubbles may be mixed. .

  In addition, such bubbles usually have a spherical shape, but may have an irregular spherical shape. In the said bubble, it does not specifically limit as the average bubble diameter (diameter), For example, it can select from the range of 1-1000 micrometers (preferably 10-500 micrometers, More preferably, 30-300 micrometers).

  The gas component contained in the bubbles (gas component forming bubbles; sometimes referred to as “bubble-forming gas”) is not particularly limited, and air, in addition to an inert gas such as nitrogen, carbon dioxide, and argon. Various gas components such as can be used. As the bubble forming gas, when a reaction such as a polymerization reaction is performed after mixing the bubble forming gas, it is important to use a gas that does not inhibit the reaction. As the bubble forming gas, nitrogen is preferable from the viewpoint of not inhibiting the reaction and from the viewpoint of cost.

(Hollow microsphere)
By using a hollow microsphere as one of the components of the bubble-containing viscoelastic composition of the present invention, for example, the shear adhesive force in the bubble-containing pressure-sensitive adhesive composition can be increased, and the workability can be improved. Can be improved. The hollow microspheres can be used alone or in combination of two or more.

  The hollow microspheres used in the present invention may be hollow inorganic microspheres or hollow organic microspheres. Specifically, as the hollow inorganic microspheres in the hollow microspheres, for example, glass hollow balloons such as hollow glass balloons; metal compound hollow balloons such as hollow alumina balloons; hollow ceramic balloons and the like Examples include porcelain hollow balloons. Examples of the hollow organic microspheres include resin hollow balloons such as hollow acrylic balloons and hollow vinylidene chloride balloons.

  Although it does not restrict | limit especially as a particle size (average particle diameter) of a hollow microsphere, For example, it can select from the range of 1-500 micrometers (preferably 5-200 micrometers, More preferably, 10-100 micrometers).

The specific gravity of the hollow microspheres is not particularly limited, for example, 0.1 to 0.8 g / cm ³ (preferably 0.12 / cm ³⁾ can be selected from the range of. If the specific gravity of the hollow microspheres is less than 0.1 g / cm ³ , when the hollow microspheres are mixed and mixed in the bubble-containing viscoelastic composition, the floating becomes large and difficult to disperse uniformly. On the other hand, if it is larger than 0.8 g / cm ³ , it becomes expensive and the cost becomes high.

  The amount of the hollow microspheres used is not particularly limited, and for example, 5 to 50% by volume (% by volume) with respect to the total volume of the bubble-containing viscoelastic layer formed from the bubble-containing viscoelastic composition, preferably It can be selected from a range of 10 to 50% by volume, more preferably 15 to 40% by volume. The effect of adding the hollow microspheres when the usage amount of the hollow microspheres is less than 5% by volume with respect to the total volume of the bubble-containing viscoelastic layer formed by the bubble-containing viscoelastic composition On the other hand, when the usage amount exceeds 50% by volume, for example, when the bubble-containing viscoelastic layer is a bubble-containing pressure-sensitive adhesive layer, the adhesive strength of the bubble-containing pressure-sensitive adhesive layer is reduced. .

(Fluorosurfactant)
As the fluorine-based surfactant, a fluorine-based surfactant having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group in the molecule is used. The oxy C _2-3 alkylene group is represented by the formula: —R—O— (R is a linear or branched alkylene group having 2 or 3 carbon atoms). By having an oxy C _2-3 alkylene group in the molecule, the degree of adhesion and frictional resistance between the hollow microspheres and the base polymer in the bubble-containing viscoelastic layer are reduced, and stress dispersibility is exhibited. Therefore, when the pressure-sensitive adhesive layer is formed using the bubble-containing viscoelastic composition of the present invention, high adhesiveness is obtained. By having a fluorinated hydrocarbon group, in addition to the effect of reducing the frictional resistance and the like, the effect of improving the bubble mixing property and bubble stability is also obtained. The fluorosurfactant is not particularly limited as long as it has an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group, but a nonionic surfactant is preferred from the viewpoint of dispersibility with respect to the base polymer. Further, the molecule may have any one kind of oxyethylene group (—CH ₂ CH ₂ O—), oxypropylene group [—CH ₂ CH (CH ₃ ) O—], etc., and two or more kinds. You may have. In addition, a fluorine-type surfactant can be used individually or in combination of 2 or more types.

The fluorinated hydrocarbon group is not particularly limited, but is preferably a perfluoro group, and the perfluoro group may be monovalent or divalent or higher. Further, the fluorinated hydrocarbon group may have a double bond or a triple bond, and may be a straight chain or a branched structure or a cyclic structure. It does not specifically limit as carbon number of a fluorinated hydrocarbon group, It is 1 or 2 or more, Preferably it is 3-30, More preferably, it is 4-20. One or two or more of these fluorinated hydrocarbon groups are introduced into the surfactant molecule. Examples of the oxy C _2-3 alkylene group include alcohols in which a hydrogen atom is bonded to a terminal oxygen atom, ethers bonded to other hydrocarbon groups, and esters bonded to other hydrocarbon groups via a carbonyl group. Form may be sufficient. Moreover, the form which has this structure in a part of cyclic structure, such as cyclic ethers and lactones, may be sufficient.

The structure of the fluorosurfactant is not particularly limited. For example, a copolymer containing a monomer having an oxy C _2-3 alkylene group and a monomer having a fluorinated hydrocarbon group as a monomer component is preferably used. Can be used. As such a copolymer, various structures such as a block copolymer and a graft copolymer are conceivable, and any of them is preferably used.

Examples of the block copolymer (copolymer having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group in the main chain) include polyoxyethylene perfluoroalkyl ether, polyoxyethylene perfluoroalkylate, polyoxyethylene Examples thereof include propylene perfluoroalkyl ether, polyoxyisopropylene perfluoroalkyl ether, polyoxyethylene sorbitan perfluoroalkylate, polyoxyethylene polyoxypropylene block copolymer perfluoroalkylate, and polyoxyethylene glycol perfluoroalkylate.

As a graft copolymer (a copolymer having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group in the side chain), at least a vinyl compound having a polyoxyalkylene group and a fluorinated hydrocarbon group as a monomer component A copolymer containing a vinyl-based compound having, particularly an acrylic copolymer, is preferably used. Examples of the vinyl compound having a polyoxyalkylene group include polyoxyalkylene (meth) acrylates such as polyoxyethylene (meth) acrylate, polyoxypropylene (meth) acrylate, and polyoxyethylene polyoxypropylene (meth) acrylate. Can be mentioned. Examples of vinyl compounds having a fluorinated hydrocarbon group include perfluoroalkyl (meth) acrylates such as perfluorobutyl (meth) acrylate, perfluoroisobutyl (meth) acrylate, and perfluoropentyl (meth) acrylate, fluorine And (meth) acrylic acid ester containing a fluorinated hydrocarbon.

  In addition to the above structure, the fluorosurfactant may have a structure such as an alicyclic hydrocarbon group or an aromatic hydrocarbon group in the molecule, as long as the dispersibility in the base polymer is not inhibited. You may have various functional groups, such as a carboxyl group, a sulfonic acid group, a cyano group, an amide group, an amino group. For example, when the fluorosurfactant is a vinyl copolymer, a monomer component copolymerizable with a vinyl compound having a polyoxyalkylene group and a vinyl compound having a fluorinated hydrocarbon group is used as the monomer component. May be. Such monomers can be used alone or in combination of two or more.

Examples of the copolymerizable monomer component include (meth) acrylic acid C _1-20 alkyl esters such as undecyl (meth) acrylate and dodecyl (meth) acrylate; alicyclic carbonization such as cyclopentyl (meth) acrylate. A (meth) acrylic acid ester having a hydrogen group; a (meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate is preferably used. In addition, carboxyl group-containing monomers such as maleic acid and crotonic acid; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; aromatic vinyl compounds such as styrene and vinyl toluene; olefins and dienes such as ethylene and butadiene Vinyl ethers such as vinyl alkyl ethers; amide group-containing monomers such as acrylamide; amino group-containing monomers such as (meth) acryloylmorpholine; glycidyl group-containing monomers such as methyl glycidyl (meth) acrylate; 2 -Isocyanate group-containing monomers such as methacryloyloxyethyl isocyanate. Furthermore, polyfunctional copolymerizable monomers (polyfunctional monomers) such as dipentaerythritol hexa (meth) acrylate and divinylbenzene may be used.

  The molecular weight of the fluorosurfactant is not particularly limited, but when the weight average molecular weight is less than 20000 (for example, 500 or more and less than 20000), the adhesion between the base polymer and the hollow microspheres in the viscoelastic composition Highly effective in reducing frictional resistance. Furthermore, when a fluorosurfactant having a weight average molecular weight of 20000 or more (for example, 20000 to 100000, preferably 22000 to 80000, more preferably 24000 to 60000) is used in combination, the mixing property of the bubbles and the stability of the mixed bubbles are increased. .

As a specific example of a fluorosurfactant having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group and having a weight average molecular weight of less than 20000, trade name “Futgent 251” (manufactured by Neos Co., Ltd.), product Name “FTX-218” (manufactured by Neos Co., Ltd.), trade name “Megafac F-477” (manufactured by Dainippon Ink & Chemicals, Inc.) ), Trade name “Surflon S-381” (manufactured by Sey Chemical Co., Ltd.), trade name “Surflon S-383” (manufactured by Sey Chemical Co., Ltd.), trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd.) Trade name “Surflon KH-20” (manufactured by Sey Chemical Co., Ltd.), trade name “Surflon KH-40” (manufactured by Sey Chemical Co., Ltd.), and the like. As a specific example of the fluorosurfactant having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group and having a weight average molecular weight of 20000 or more, a trade name “F-top EF-352” (manufactured by Gemco Co., Ltd.) ), Trade name “F-top EF-801” (manufactured by Gemco Co., Ltd.), trade name “Unidyne TG-656” (manufactured by Daikin Industries, Ltd.), and the like, and any of them can be suitably used in the present invention.

  The amount of use (solid content) of the fluorosurfactant is not particularly limited. For example, all the monomer components for forming the base polymer of the bubble-containing viscoelastic composition [particularly, a (meth) acrylic acid alkyl ester is used alone. Total monomer components for forming acrylic polymer as main component of monomer] 0.01 to 5 parts by weight (preferably 0.02 to 3 parts by weight, more preferably 0.03 parts by weight) with respect to 100 parts by weight ˜1 part by weight). If it is less than 0.01 part, the effect on the adhesive performance cannot be obtained, and if it exceeds 5 parts by weight, the adhesive performance is deteriorated.

(Base polymer)
The base polymer in the bubble-containing viscoelastic composition is not particularly limited. When the bubble-containing viscoelastic composition is a pressure-sensitive adhesive composition containing bubbles (bubble-containing pressure-sensitive adhesive composition), for example, a known pressure-sensitive adhesive (pressure-sensitive adhesive) (for example, acrylic pressure-sensitive adhesive) Adhesives, rubber pressure sensitive adhesives, vinyl alkyl ether pressure sensitive adhesives, silicone pressure sensitive adhesives, polyester pressure sensitive adhesives, polyamide pressure sensitive adhesives, urethane pressure sensitive adhesives, fluorine based feeling Pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, etc.) can be appropriately selected from base polymers. That is, the bubble-containing pressure-sensitive adhesive composition using the viscoelastic composition of the present invention includes an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a vinyl alkyl ether-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. Compositions using known pressure-sensitive adhesives such as adhesives, polyester-based pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, fluorine-based pressure-sensitive adhesives, and epoxy-based pressure-sensitive adhesives It may be.

  On the other hand, when the bubble-containing viscoelastic composition is a substrate containing bubbles, it can be appropriately selected from the same polymers as the base polymer in the bubble-containing pressure-sensitive adhesive composition.

A base polymer can be used individually or in combination of 2 or more types. As the base polymer, a base polymer in a known acrylic pressure-sensitive adhesive can be suitably used. Known acrylic pressure-sensitive adhesives usually contain an acrylic polymer [particularly an acrylic polymer containing (meth) acrylic acid ester as a monomer component] as a base polymer. In the acrylic polymer, a (meth) acrylic acid alkyl ester can be suitably used. Examples of the (meth) acrylic acid alkyl ester in the acrylic polymer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid. Butyl, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, (meth ) Heptyl acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, ( (Meth) isodecyl acrylate, undecyl (meth) acrylate, (Meth) acrylic acid dodecyl, (meth) acrylic acid tridecyl, (meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylic acid heptadecyl, (meth) acrylic acid octadecyl, (meta ) (Meth) acrylic acid C _1-20 alkyl ester such as nonadecyl acrylate and eicosyl (meth) acrylate [preferably (meth) acrylic acid C _2-14 alkyl ester, more preferably (meth) acrylic acid C _{2 -10} alkyl ester] and the like.

  Moreover, as (meth) acrylic acid esters other than (meth) acrylic acid alkyl ester, for example, it has an alicyclic hydrocarbon group such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, and isoboronyl (meth) acrylate ( And (meth) acrylic acid esters.

  In addition, since (meth) acrylic acid ester is used as a monomer main component of acrylic polymer, the ratio of (meth) acrylic acid ester [especially (meth) acrylic acid alkyl ester] is, for example, acrylic polymer. It is important that the amount is 60% by weight or more (preferably 80% by weight or more) with respect to the total amount of the monomer components for adjusting the amount.

  In the acrylic polymer, various copolymerizable monomers such as polar group-containing monomers and polyfunctional monomers may be used as monomer components. By using a copolymerizable monomer as the monomer component, for example, the adhesive force to the adherend can be improved, or the cohesive force of the adhesive (pressure-sensitive adhesive) can be increased. The copolymerizable monomers can be used alone or in combination of two or more.

  Examples of the polar group-containing monomer include carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, and anhydrides thereof (maleic anhydride and the like). Hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylate such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate; acrylamide, methacrylamide, N, N- Amide group-containing monomers such as dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; aminoethyl (meth) acrylate, (meta ) Dimethylaminoethyl acrylate, (meth) acrylic Amino group-containing monomers such as t-butylaminoethyl acid; glycidyl group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile Body: N-vinyl-2-pyrrolidone, (meth) acryloylmorpholine, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinyl Examples include heterocyclic-containing vinyl monomers such as oxazole. As the polar group-containing monomer, a carboxyl group-containing monomer such as acrylic acid or its anhydride is suitable.

  The amount of the polar group-containing monomer used is 30% by weight or less (for example, 1 to 30% by weight), preferably 3 to 20% by weight, based on the total amount of monomer components for adjusting the acrylic polymer. . When the usage amount of the polar group-containing monomer exceeds 30% by weight, for example, the cohesive force of the acrylic pressure-sensitive adhesive becomes too high, and the pressure-sensitive adhesiveness may be lowered. In addition, when the amount of the polar group-containing monomer used is too small (for example, less than 1% by weight based on the total amount of monomer components for preparing the acrylic polymer), the cohesive strength of the acrylic pressure-sensitive adhesive decreases. However, a high shear force cannot be obtained.

  Examples of the polyfunctional monomer include hexanediol (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, allyl (meth) acrylate, vinyl (Meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, dibutyl (meth) acrylate, hexidyl (meth) acrylate, etc. And the like.

  The amount of the polyfunctional monomer used is 2% by weight or less (for example, 0.01 to 2% by weight), preferably 0.02 to less than the total amount of monomer components for adjusting the acrylic polymer. 1% by weight. If the amount of the polyfunctional monomer used exceeds 2% by weight based on the total amount of monomer components for adjusting the acrylic polymer, for example, the cohesive force of the acrylic pressure sensitive adhesive becomes too high, and pressure sensitive adhesiveness May decrease. Moreover, when there is too little usage-amount of a polyfunctional monomer (for example, it is less than 0.01 weight% with respect to the monomer component whole quantity for adjusting adjustment of an acrylic polymer), for example, acrylic pressure sensitivity The cohesive strength of the adhesive is reduced.

  Examples of copolymerizable monomers other than polar group-containing monomers and polyfunctional monomers include vinyl esters such as vinyl acetate and vinyl propionate, aromatic vinyl compounds such as styrene vinyl toluene, Olefins or dienes such as ethylene, butadiene, isoprene and isobutylene; vinyl ethers such as vinyl alkyl ether; alkoxyalkyl (meth) acrylates such as vinyl chloride, methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate Monomer; Monomer including sulfonic acid group such as sodium vinyl sulfonate; Phosphoric group-containing monomer such as 2-hydroxyethylacryloyl phosphate; Imido group-containing monomer such as cyclohexylmaleimide and isopropylmaleimide; 2-methacryloyl Oxyethyl Isocyanate group-containing monomers such as cyanate; fluorine-containing (meth) acrylate, and silicon atom-containing (meth) acrylate.

(Polymerization initiator)
In the present invention, when the acrylic polymer is prepared as the base polymer (that is, a layer made of a bubble-containing viscoelastic composition such as a bubble-containing pressure-sensitive adhesive layer or a bubble-containing substrate (referred to as a “bubble-containing viscoelastic layer”). In the formation of the above, a curing reaction by heat or active energy rays using a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) can be used. The elastic composition may contain a polymerization initiator such as a thermal polymerization initiator, a photopolymerization initiator, etc. Therefore, the bubble-containing viscoelastic composition can be cured by heat or energy rays. If a polymerization initiator (thermal polymerization initiator, photopolymerization initiator, etc.) is included, curing with heat or active energy rays becomes possible. By forming the sexual composition (such as a bubble-containing pressure-sensitive adhesive layer or bubble-containing substrate), air bubbles can be easily formed a bubble-containing viscoelastic layer having a stable contained in structure.

As such a polymerization initiator, a photopolymerization initiator can be suitably used because of the advantage that the polymerization time can be shortened. That is, it is preferable to form a bubble-containing pressure-sensitive adhesive layer having a stable cell structure using polymerization using active energy rays.
In addition, a polymerization initiator can be used individually or in combination of 2 or more types.

  The polymerization initiator is not particularly limited, and for example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactivity An oxime photopolymerization initiator, a benzoin photopolymerization initiator, a benzyl photopolymerization initiator, a benzophenone photopolymerization initiator, a ketal photopolymerization initiator, a thioxanthone photopolymerization initiator, or the like can be used.

  Specifically, examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane- Examples include 1-one and anisole methyl ether. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4- (t-butyl). Examples include dichloroacetophenone. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one. . Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.

  The benzoin photopolymerization initiator includes, for example, benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinyl benzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

  The amount of the photopolymerization initiator used is not particularly limited. For example, all the monomer components for forming the base polymer in the bubble-containing pressure-sensitive adhesive composition [particularly, (meth) acrylic acid ester is used as the monomer. The total monomer components for forming the acrylic polymer as the main component] can be selected from the range of 0.01 to 5 parts by weight (preferably 0.05 to 3 parts by weight) with respect to 100 parts by weight.

  In activating the photopolymerization initiator, it is important to irradiate the bubble-containing viscoelastic composition with an active energy ray. Examples of such active energy rays include ionizing radiation such as α rays, β rays, γ rays, neutron rays, electron rays, and ultraviolet rays, and ultraviolet rays are particularly preferable. The irradiation energy of the active energy beam, the irradiation time, etc. are not particularly limited as long as the photopolymerization initiator can be activated to cause the reaction of the monomer component.

  Examples of the thermal polymerization initiator include azo polymerization initiators [for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2 ′. -Azobis (2-methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'- Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N ' -Dimethyleneisobutylamidine) dihydrochloride, etc.], peroxide polymerization initiators (eg, dibenzoyl peroxide, t-butylpermaleate, etc.) And redox polymerization initiators. The amount of the thermal polymerization initiator used is not particularly limited as long as it can be conventionally used as a polymerization initiator.

(Other ingredients)
In addition to the above components (fluorine-based surfactant, base polymer, hollow microsphere, polymerization initiator, etc.), the bubble-containing viscoelastic composition of the present invention, depending on the use of the bubble-containing viscoelastic composition, Appropriate additives may be included. For example, when the bubble-containing viscoelastic composition is a bubble-containing pressure-sensitive adhesive layer, a crosslinking agent (for example, polyisocyanate) is used depending on the type of the pressure-sensitive adhesive for forming the bubble-containing pressure-sensitive adhesive layer. Solid crosslinkers, silicone crosslinkers, epoxy crosslinkers, alkyl etherified melamine crosslinkers, etc.) and tackifiers (for example, rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenol resins, etc.) Appropriate additives such as plasticizers, fillers, anti-aging agents, and colorants (pigments, dyes, etc.). For example, when a bubble-containing viscoelastic layer is formed using a photopolymerization initiator, a pigment (colored pigment) that does not inhibit photopolymerization can be used to color the bubble-containing viscoelastic layer. When black is desired as the coloring of the bubble-containing viscoelastic layer, for example, carbon black can be used. The amount of carbon black used as the coloring pigment is, for example, all monomers for forming the base polymer in the bubble-containing viscoelastic composition [especially (meth) acrylic from the viewpoint of not inhibiting the degree of coloring and the photopolymerization reaction. All monomer components for forming acrylic polymer having acid ester as monomer] 0.15 parts by weight or less (for example, 0.001 to 0.15 parts by weight), preferably 0.02 to 100 parts by weight It is desirable to select from the range of 0.1 parts by weight.

  In the present invention, in order to allow bubbles to be stably mixed and present in the bubble-containing viscoelastic composition, the bubbles are preferably blended and mixed as the last component in the bubble-containing viscoelastic composition. A bubble-containing viscoelastic composition (which may be referred to as a “bubble-containing viscoelastic precursor”; for example, when the bubble-containing viscoelastic composition is a bubble-containing pressure-sensitive adhesive composition) It is preferable to increase the viscosity of the agent precursor. The viscosity of the bubble-containing viscoelastic precursor (such as a pressure-sensitive adhesive precursor) is not particularly limited as long as it is a viscosity capable of stably holding the mixed bubbles. Using the gauge, rotor: No. The viscosity measured under the conditions of 5 rotors, rotation speed: 10 rpm, and measurement temperature: 30 ° C. is preferably 5 to 50 Pa · s (preferably 10 to 40 Pa · s). When the viscosity of the bubble-containing viscoelastic precursor (BH viscometer, No. 5 rotor, 10 rpm, 30 ° C.) is less than 5 Pa · s, the viscosity is too low, and the mixed bubbles immediately coalesce. On the other hand, if it exceeds 50 Pa · s, it is difficult to form a bubble-containing viscoelastic layer because the viscosity is too high.

  The viscosity of the bubble-containing viscoelastic precursor is determined by, for example, a method of blending various polymer components such as acrylic rubber and a thickening additive, and a monomer component for forming a base polymer [for example, for forming an acrylic polymer. The monomer component such as (meth) acrylic acid ester] can be partially polymerized. Specifically, for example, a monomer component for forming a base polymer [for example, a monomer component such as (meth) acrylic acid ester for forming an acrylic polymer, etc.] and a polymerization initiator (for example, photopolymerization initiation) To prepare a composition (syrup) in which only a part of the monomer components are polymerized by preparing a monomer mixture by carrying out a polymerization reaction according to the type of the polymerization initiator. After that, a foam-containing viscosity having an appropriate viscosity capable of stably containing bubbles by blending the syrup with a fluorosurfactant, hollow microspheres, and various additives as required. Elastic precursors can be prepared. And the bubble containing viscoelastic composition which contains the bubble stably can be obtained by introduce | transducing and mixing a bubble to this bubble containing viscoelastic precursor. In preparing the syrup, a fluorosurfactant and hollow microspheres may be appropriately blended in advance during monomer mixing.

  The method for mixing bubbles is not particularly limited, and a known bubble mixing method can be used. For example, as an example of the device, a stator having a large number of fine teeth on a disk having a through hole in the center and a stator having teeth are opposed to each other, and the same fine teeth as the stator are on the disk. And a device having a rotor with a mark. A gas component (bubble forming gas) for forming bubbles through the through-hole while introducing a bubble-containing viscoelastic precursor between the teeth on the stator and the teeth on the rotor in this apparatus and rotating the rotor at a high speed. By introducing into the bubble-containing viscoelastic precursor, a bubble-containing viscoelastic composition in which the bubble-forming gas is finely dispersed and mixed in the bubble-containing viscoelastic precursor can be obtained.

  In order to suppress or prevent the coalescence of the bubbles, it is preferable to continuously perform the steps from the mixing of the bubbles to the formation of the bubble-containing viscoelastic layer as a series of steps. That is, after preparing a bubble-containing viscoelastic composition by mixing bubbles as described above, subsequently, using the bubble-containing viscoelastic composition, a known pressure-sensitive adhesive layer forming method is used. It is preferable to form a bubble-containing viscoelastic layer.

(Pressure-sensitive adhesive tape or sheet)
The pressure-sensitive adhesive tape or sheet of the present invention has a bubble-containing pressure-sensitive adhesive layer and / or a bubble-containing substrate formed from the bubble-containing viscoelastic composition. Such a pressure-sensitive adhesive tape or sheet may have a form of a double-sided pressure-sensitive adhesive tape or sheet in which both surfaces are adhesive surfaces (adhesive surface), and only one surface is an adhesive surface. It may have the form of a pressure sensitive adhesive tape or sheet. Specifically, as the pressure-sensitive adhesive tape or sheet, when the bubble-containing viscoelastic layer formed of the bubble-containing viscoelastic composition is a bubble-containing pressure-sensitive adhesive layer, for example, FIG. 1 (a) or (b (1) It has a bubble-containing pressure-sensitive adhesive layer having a structure in which a bubble-containing adhesive layer is formed on at least one surface of the substrate and an adhesive surface is formed on both sides of the substrate. Double-sided pressure-sensitive adhesive tape or sheet with a base material (double-sided pressure-sensitive adhesive tape or sheet with a base material having a bubble-containing pressure-sensitive adhesive layer), as shown in FIG. 1 (c), (2) one side of the base material A pressure-sensitive adhesive tape or sheet with a substrate having a bubble-containing pressure-sensitive adhesive layer having a structure in which a bubble-containing pressure-sensitive adhesive layer is formed (a single-sided pressure-sensitive adhesive tape or sheet with a substrate having a bubble-containing pressure-sensitive adhesive layer) ), As shown in FIG. 3) Substrate-less double-sided pressure-sensitive adhesive tape or sheet having a bubble-containing pressure-sensitive adhesive layer configured only from a bubble-containing pressure-sensitive adhesive layer (base-less double-sided feeling having a bubble-containing pressure-sensitive adhesive layer) Pressure adhesive tape or sheet).

  FIG. 1 is a schematic sectional view partially showing an example of the pressure-sensitive adhesive tape or sheet of the present invention. In FIG. 1, 1, 11, 12, and 13 are pressure-sensitive adhesive tapes or sheets each having a bubble-containing pressure-sensitive adhesive layer, 2 is a bubble-containing pressure-sensitive adhesive layer, and 3 is a substrate (bubble-free group). Material), 4 is a pressure-sensitive adhesive layer (bubble-free pressure-sensitive adhesive layer), and the pressure-sensitive adhesive tape or sheet having the bubble-containing pressure-sensitive adhesive layer shown in FIG. It has the structure by which the bubble-containing pressure-sensitive adhesive layer 2 was formed on both surfaces of the containing base material 3. In the pressure-sensitive adhesive tape or sheet 11 having the bubble-containing pressure-sensitive adhesive layer shown in FIG. 1B, the bubble-containing pressure-sensitive adhesive layer 2 is formed on one side of the bubble-free substrate 3 and the other. This has a structure in which a bubble-free pressure-sensitive adhesive layer 4 is formed on the surface. The pressure-sensitive adhesive tape or sheet 12 having the bubble-containing pressure-sensitive adhesive layer shown in FIG. 1C has a configuration in which the bubble-containing pressure-sensitive adhesive layer 2 is formed on one side of the bubble-free substrate 3. is doing. The pressure-sensitive adhesive tape or sheet 13 having a bubble-containing pressure-sensitive adhesive layer shown in FIG. 1 (d) has a configuration formed only by the bubble-containing pressure-sensitive adhesive layer 2.

  When the pressure-sensitive adhesive tape or sheet having the bubble-containing adhesive layer is a double-sided pressure-sensitive adhesive tape or sheet with a substrate as shown in FIGS. 1 (a) and (b), in FIG. As shown, the pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) formed on both sides of the substrate may be a bubble-containing pressure-sensitive adhesive layer, and as shown in FIG. The pressure-sensitive adhesive layer formed on one surface of the substrate may be a pressure-sensitive adhesive layer that does not contain bubbles (sometimes referred to as a “bubble-free pressure-sensitive adhesive layer”). . Moreover, as shown in FIGS. 1A to 1C, (1) a pressure-sensitive adhesive layer is formed on at least one surface of a bubble-containing substrate, and an adhesive surface is formed on both sides of the substrate. As shown in FIG. 2 (b), a double-sided pressure-sensitive adhesive tape or sheet with a base material having a bubble-containing base material having a structure as described above (2) ) A pressure-sensitive adhesive tape or sheet with a substrate having a bubble-containing substrate having a structure in which a pressure-sensitive adhesive layer is formed on one side of the bubble-containing substrate (single-sided adhesive tape with a substrate having a bubble-containing substrate or Sheet).

  FIG. 2 is a schematic sectional view partially showing an example of the pressure-sensitive adhesive tape or sheet of the present invention. In FIG. 2, 14 and 15 are pressure-sensitive adhesive tapes or sheets each having a bubble-containing substrate, 5 is a bubble-containing substrate, and 6 is a pressure-sensitive adhesive layer. The pressure-sensitive adhesive tape or sheet 14 having a bubble-containing substrate shown in FIG. 2A has a configuration in which the pressure-sensitive adhesive layer 6 is formed on both surfaces of the bubble-containing substrate 5. The pressure-sensitive adhesive tape or sheet 15 having a bubble-containing substrate shown in FIG. 2B has a configuration in which a pressure-sensitive adhesive layer 6 is formed on one side of the bubble-containing substrate 5.

  In the pressure-sensitive adhesive tape or sheet having the bubble-containing substrate shown in FIGS. 2A and 2B, the pressure-sensitive adhesive layer is a bubble-containing pressure-sensitive adhesive formed by a bubble-containing viscoelastic composition. It may be an agent layer or a bubble-free pressure-sensitive adhesive layer. Moreover, in the double-sided pressure-sensitive adhesive tape or sheet with a base material having a bubble-containing base material, the two pressure-sensitive adhesive layers may be the same pressure-sensitive adhesive layer or different pressure-sensitive adhesive layers. Good. That is, the double-sided pressure-sensitive adhesive tape or sheet with a base material having a bubble-containing base has a structure in which the pressure-sensitive adhesive layer on both sides is a bubble-containing pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer on one side is a bubble. The pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer on the other side, and the pressure-sensitive adhesive layer on both sides is a bubble-free pressure-sensitive adhesive layer. Any one of the configurations may be included.

  Moreover, the pressure-sensitive adhesive tape or sheet may be formed in a form wound in a roll shape, or may be formed in a form in which sheets are laminated. That is, the pressure-sensitive adhesive tape or sheet of the present invention can have a form such as a sheet form or a tape form. When the pressure-sensitive adhesive tape or sheet is wound into a roll shape, for example, a pressure-sensitive adhesive layer such as a bubble-containing pressure-sensitive adhesive layer is formed on the back side of the separator or substrate. It can produce by winding in a roll shape in the state protected by the made peeling process layer.

(Bubble-containing viscoelastic layer)
A bubble-containing viscoelastic layer (a bubble-containing pressure-sensitive adhesive layer or a bubble-containing substrate) formed of a bubble-containing viscoelastic composition is a known pressure-sensitive property using a bubble-containing viscoelastic composition as described above. It can form using the formation method of an adhesive bond layer or a bubble containing base material. For example, a bubble-containing viscoelastic layer such as a bubble-containing pressure-sensitive adhesive layer or a bubble-containing substrate is obtained by applying a bubble-containing viscoelastic composition on a predetermined surface and performing drying or curing as necessary. Can be formed. In addition, when forming the bubble-containing viscoelastic layer, it is preferable to cure by heating or irradiation with active energy rays as described above. That is, using a bubble-containing viscoelastic composition containing a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator, the bubble-containing viscoelastic composition is applied on a predetermined surface, and then heated or activated. A bubble-containing viscoelastic layer such as a bubble-containing pressure-sensitive adhesive layer or a bubble-containing substrate can be suitably formed by irradiating with energy rays and curing in a state where the bubbles are stably held.

  The thickness of the bubble-containing viscoelastic layer (the bubble-containing viscoelastic adhesive layer or the bubble-containing substrate) is not particularly limited, and is, for example, in the range of 200 to 5000 μm (preferably 300 to 4000 μm, more preferably 400 to 3000 μm). You can choose from. When the thickness of the bubble-containing viscoelastic layer is smaller than 200 μm, the cushioning property is lowered, and the adhesion to a curved surface or an uneven surface is lowered. When the thickness is larger than 5000 μm, it is difficult to obtain a layer or sheet having a uniform thickness. .

  The bubble-containing viscoelastic layer may have either a single layer or multiple layers.

(Base material)
In the pressure-sensitive adhesive tape or sheet having a bubble-containing pressure-sensitive adhesive layer, when the substrate is a bubble-free substrate, examples of the substrate include paper-based substrates such as paper; cloth, unemployed cloth, Fiber base materials such as nets; metal base materials such as metal foils and metal plates; plastic base materials such as plastic films and sheets; rubber base materials such as rubber sheets; foams such as foam sheets and the like An appropriate thin leaf body such as a laminate (particularly, a laminate of a plastic substrate and another substrate or a laminate of plastic films (or sheets)) can be used. As a material in such a plastic film or sheet, for example, an α-olefin such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) or the like is used as a monomer component. Olefin resins: Polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); Polyvinyl chloride (PVC); Vinyl acetate resin; Polyphenylene sulfide (PPS) Amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyimide resins; polyether ether ketone (PEEK) and the like. These materials can be used alone or in combination of two or more.

  In addition, when a plastic-type base material is used as a base material, you may control deformability, such as elongation rate, by an extending | stretching process. As a base material. When the bubble-containing pressure-sensitive adhesive layer is formed by curing with an active energy beam, it is preferable to use one that does not inhibit the transmission of the active energy beam.

  The thickness of the substrate can be appropriately selected according to the strength, flexibility, purpose of use, and the like. For example, it is generally 1000 μm or less (for example, 1 to 1000 μm), preferably 1 to 500 μm, more preferably 3 to 300 μm. However, it is not limited to these. In addition, the base material may have a single layer form or may have a laminated form.

  In order to improve the adhesion of the surface of the base material with the bubble-containing pressure-sensitive adhesive layer, etc., conventional surface treatments such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation treatment, etc. These may be subjected to an oxidation treatment or the like by a chemical or physical method, or may be subjected to a coating treatment with an undercoat agent or a release agent.

(Bubble-free pressure-sensitive adhesive layer)
In the pressure-sensitive adhesive tape or sheet having a bubble-containing pressure-sensitive adhesive layer and / or a bubble-containing substrate, the pressure-sensitive adhesive layer has a non-bubble-containing pressure-sensitive adhesive layer (for example, a bubble-containing pressure-sensitive adhesive layer). The pressure-sensitive adhesive tape or sheet having an adhesive layer is a double-sided pressure-sensitive adhesive tape or sheet with a substrate, a bubble-containing pressure-sensitive adhesive layer is formed on one surface of the substrate, and bubbles are formed on the other surface of the substrate In the case where a non-containing pressure-sensitive adhesive layer is formed), the bubble-free pressure-sensitive adhesive layer is a known pressure-sensitive adhesive (for example, acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, vinyl Alkyl ether pressure sensitive adhesive, silicone pressure sensitive adhesive, polyester pressure sensitive adhesive, polyamide pressure sensitive adhesive, urethane pressure sensitive adhesive, fluorine pressure sensitive adhesive, epoxy pressure sensitive adhesive The thickness of the non-bubble-containing pressure-sensitive adhesive layer is not particularly limited, and the purpose, usage, etc. It can be selected as appropriate according to the conditions.

(Separator)
In the present invention, a separator (release liner) is used to protect the adhesive surface (adhesive surface) of a pressure-sensitive adhesive layer such as a bubble-containing pressure-sensitive adhesive layer or a bubble-free pressure-sensitive adhesive layer. Also good. That is, the separator does not necessarily have to be provided. The separator is peeled off when the adhesive surface protected by the separator is used (that is, when the adherend is attached to the pressure-sensitive adhesive layer protected by the separator).

  A conventional release paper or the like can be used as such a separator. Specifically, as the separator, for example, in addition to a substrate having a release treatment layer with a release treatment agent on at least one surface, a fluorine-based polymer (eg, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride) , Low-adhesive substrates made of polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc., and nonpolar polymers (for example, olefins such as polyethylene and polypropylene) A low-adhesive base material made of a resin or the like can be used. The separator can also be used as a base material for supporting the bubble-containing pressure-sensitive adhesive layer.

  As the separator, for example, a separator having a release treatment layer formed on at least one surface of a release liner substrate can be suitably used. Examples of such release liner substrates include polyester films (polyethylene terephthalate films, etc.), olefin resin films (polyethylene films, polypropylene films, etc.), polyvinyl chloride films, polyimide films, polyamide films (nylon films), rayon films. In addition to plastic base film (synthetic resin film) and papers (quality paper, Japanese paper, kraft paper, glassine paper, synthetic paper, topcoat paper, etc.), etc. (2-3 layer composite) etc. are mentioned.

  On the other hand, the release treatment agent constituting the release treatment layer is not particularly limited, and for example, a silicone release treatment agent, a fluorine release treatment agent, a long-chain alkyl release treatment agent, or the like can be used. The release treatment agents can be used alone or in combination of two or more.

  In addition, the thickness of a separator, a formation method, etc. are not restrict | limited in particular.

  The pressure-sensitive adhesive sheet or tape of the present invention has a low frictional resistance between the hollow microsphere and the base polymer in the viscoelastic composition, and has a high stress dispersibility, such as a pressure-sensitive adhesive layer or a bubble-containing substrate. Since it has a containing viscoelastic layer, it can exhibit good adhesion to curved surfaces and uneven surfaces, and can exhibit excellent resilience resistance. Therefore, the pressure-sensitive adhesive tape or sheet is preferably used as a pressure-sensitive adhesive tape or sheet to be applied to a curved surface or an uneven surface, or a pressure-sensitive adhesive tape or sheet used in applications that require repulsion resistance. it can.

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

(Example 1 : Reference example )
As a monomer component, 90 parts by weight of 2-ethylhexyl acrylate and 10 parts by weight of acrylic acid were mixed, and as a photopolymerization initiator, trade name “Irgacure 651” (manufactured by Ciba Specialty Chemical Co.) 0. After blending 05 parts by weight and 0.05 part by weight of the trade name “Irgacure 184” (manufactured by Ciba Specialty Chemicals), the viscosity (BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) is Ultraviolet rays were irradiated to about 15 Pa · s to prepare a partially polymerized composition (syrup). To this syrup, 0.1 part by weight of 1,6-hexanediol diacrylate was added. Furthermore, as a hollow glass balloon, a trade name “Cell Star Z-27” (manufactured by Tokai Kogyo Co., Ltd.) was added at a rate of 30% by volume with respect to the total volume of syrup. Furthermore, as a fluorosurfactant, a trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; an acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 1 part by weight was added to prepare a pressure sensitive adhesive precursor. The volume of the hollow glass balloon in the pressure sensitive adhesive precursor is about 23% by volume with respect to the total volume of the pressure sensitive adhesive precursor. The pressure-sensitive adhesive precursor is opposed to a stator having a large number of fine teeth and a stator having teeth on a disk having a through hole in the center, and the same fineness as that of the stator on the disk. Nitrogen was introduced and air bubbles were mixed using a device equipped with a rotor with teeth. The amount of bubbles mixed was introduced to be about 15% by volume with respect to the total volume of the discharged liquid, and a bubble mixed pressure-sensitive adhesive composition was obtained.

The bubble mixed pressure-sensitive adhesive composition is guided to a wet lami roll coater with a tube having a diameter of 19 mm and a length of about 1.5 m, and the release treatment surface of the polyethylene terephthalate base material subjected to the release treatment on one side. In the meantime, the bubble-mixing pressure-sensitive adhesive was applied so that the thickness after drying and curing was 1.0 mm. That is, the bubble mixed pressure-sensitive adhesive is sandwiched between polyethylene terephthalate substrates. Next, ultraviolet rays having an illuminance of about 5 mW / cm ² were irradiated from both sides for 3 minutes to cure the bubble mixed pressure sensitive adhesive, and a pressure sensitive adhesive sheet having a pressure sensitive adhesive by the bubble mixed pressure sensitive adhesive was produced.

(Example 2 : Reference example )
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; an acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) as a fluorosurfactant 0.1 Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except for the addition.

(Example 3)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except for the addition.

Example 4
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 1.5 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except for the addition.

(Example 5)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 3.0 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except for the addition.

(Example 6)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight Addition and pressure sensitive adhesion with the same formulation as Example 1 except that the product name “Cell Star Z-27” (manufactured by Tokai Kogyo Co., Ltd.) is added as a hollow glass balloon at a rate of 10% by volume with respect to the total volume of syrup A sheet was produced.

(Example 7)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight Addition and pressure sensitive adhesive with the same formulation as in Example 1 except that the product name “Cell Star Z-27” (manufactured by Tokai Kogyo Co., Ltd.) is added as a hollow glass balloon at a ratio of 20% by volume with respect to the total volume of syrup. A sheet was produced.

(Example 8)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight Addition and pressure sensitive adhesion with the same formulation as Example 1 except that the product name “Cell Star Z-27” (manufactured by Tokai Kogyo Co., Ltd.) was added as a hollow glass balloon at a ratio of 40% by volume with respect to the total volume of syrup. A sheet was produced.

Example 9
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the amount of bubbles added was about 8% by volume with respect to the total volume of the discharged liquid.

(Example 10)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the amount of bubbles added was about 35% by volume with respect to the total volume of the discharged liquid.

(Comparative Example 1)
Instead of the product name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd.), the product name “Surflon SC-101” (manufactured by Sey Chemical Co., Ltd .; an acrylic copolymer containing no oxy C _2-3 alkylene group in the molecule) A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that 1.0 part by weight of a polymer, M _W = 6000) was added.

(Comparative Example 2)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the fluorosurfactant was not added. Since the surfactant was not added, the stability of the bubbles was poor and the coalescence of the bubbles occurred, and many holes penetrating the sheet were seen.

(Comparative Example 3)
Trade name “Surflon S-393” (manufactured by Sey Chemical Co., Ltd .; acrylic copolymer having a polyoxyethylene group and a fluorinated hydrocarbon group in the side chain, M _W = 8300) 0.7 as a fluorosurfactant Part by weight, trade name “Unidyne TG656” (manufactured by Daikin Industries, Ltd .; acrylic copolymer having polyoxyethylene polyoxypropylene group and fluorinated hydrocarbon group in the side chain, M _W = 46000) 0.1 part by weight A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that a hollow glass balloon was added.

(Test evaluation)
The following tests were conducted on the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples. The test results are shown in Table 1.

(Adhesive strength)
The obtained pressure-sensitive adhesive sheet was cut into a width of 25 mm and a length of 100 mm. The release liner made of polyethylene terephthalate on one side of the obtained sample piece was peeled off, and a 50 μm thick polyethylene terephthalate base material not subjected to release treatment was bonded thereto. The surface of the SUS plate polished with abrasive paper having a particle size of 280 was wiped off with toluene, and the sample was attached to the sample by pressing a roller weighing 5 kg in one way. After standing at 23 ° C. for 30 minutes, the force required for peeling was measured in an atmosphere of 23 ° C. and 65% RH (180 ° peel, tensile speed 50 mm / min).

(Shearing force)
The pressure sensitive adhesive sheet was cut into a 25 mm × 25 mm shape. The surface of the SUS plate was polished with abrasive paper having a particle size of 280 and the surface was wiped off with toluene. The release liner on one side of the sample that had been cut off was peeled off, and the sample was affixed to a SUS plate by pressing a roller weighing 5 kg in one way. Next, the other release liner was peeled off, and the sample was pasted by pressing the SUS plate with a 5 kg weight roller in one way to obtain a test piece. The test piece was allowed to stand at 23 ° C. for 30 minutes, and then the force required to peel in the shear direction in an atmosphere of 23 ° C. and 65% RH was measured (tensile speed: 50 mm / min).

(Open mouth test)
Samples were produced as follows. A pressure sensitive adhesive sheet (10 mm × 50 mm) was pressure-bonded to a geralumin plate (15 mm × 75 mm) with a 5 kg roller. After standing at room temperature for 24 hours, the surface was polished with abrasive paper with a grain size of No. 280, a SUS plate wiped off with toluene was pressed in one way with a 5 kg roller, and a test piece consisting of three layers of geralumin plate-pressure sensitive adhesive sheet-SUS plate was obtained. Produced. After leaving the test piece at room temperature for 24 hours, as shown in FIG. 3, the end of the sample was forcibly pushed open by 1.5 mm and left in a constant temperature water bath adjusted to a temperature of 40 ± 2 ° C. for 100 hours. The presence or absence of peeling was confirmed. Those that could not be peeled were marked with “○”, and those that were peeled off were marked with “×”.

DESCRIPTION OF SYMBOLS 1 Pressure sensitive adhesive tape or sheet | seat which has a bubble containing pressure sensitive adhesive layer 11 Pressure sensitive adhesive tape or sheet | seat which has a bubble containing pressure sensitive adhesive layer 12 Pressure sensitive adhesive tape or sheet which has a bubble containing pressure sensitive adhesive layer 13 Bubbles 14 Pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer 14 Pressure-sensitive adhesive tape or sheet having a cell-containing material 15 Pressure-sensitive adhesive tape or sheet having a cell-containing material 2 Cell-containing pressure-sensitive adhesive layer 3 Base material ( Non-bubble-containing substrate)
4 Pressure-sensitive adhesive layer (bubble-free pressure-sensitive adhesive layer)
5 Bubble-containing base material 6 Pressure-sensitive adhesive layer 7a Pressure-sensitive adhesive layer 7b Adherent on the upper surface side (duralumin plate)
7c Lower surface adherend (SUS plate)
7d Spacer 7e Screw hole 7f Screw

Claims (11)

The C1-C20 (meth) acrylic acid alkyl ester contains an acrylic polymer that is 60% by weight or more based on the total amount of monomer components constituting the polymer, bubbles, hollow microspheres, and a surfactant. a viscoelastic composition as the surface active agent, having an oxy- (C _2-3) alkylene group and a fluorinated hydrocarbon group in the molecule, and the weight average molecular weight of 500 to less than 20000 fluorosurfactants, molecular A fluorinated surfactant having an oxy C _2-3 alkylene group and a fluorinated hydrocarbon group and having a weight average molecular weight of 20,000 to 100,000 is used in a ratio of 7 to 30: 1 (weight ratio). A bubble-containing viscoelastic composition.   The bubble-containing viscoelastic composition according to claim 1, wherein the ratio of the fluorosurfactant is 0.01 to 5 parts by weight (solid content) with respect to 100 parts by weight of the base polymer in the viscoelastic composition.   The specific gravity of the hollow microsphere is 0.12 to 0.8 g / cm ^Three The bubble-containing viscoelastic composition according to claim 1 or 2. The bubble-containing viscoelastic composition according to any one of claims 1 to 3, wherein the hollow microsphere is a hollow glass balloon. Hollow microspheres bubble-containing viscoelastic composition according to any one of the content is 5 to 50 vol% claims 1-4 in. Bubble-containing viscoelastic composition according to any one of claims 1 to 5 the content of bubbles is 5-50% by volume. Bubble-containing viscoelastic composition according to any one of claim 1 to 6 by active energy rays are possible cure. Bubble-containing viscoelastic composition according to any one of claim 1 to 7, used as a pressure-sensitive adhesive layer. Bubble-containing organic viscoelastic composition according to any one of claim 1 to 7, used as a substrate. A pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed from the bubble-containing viscoelastic composition according to claim 8 . A pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer on at least one surface of the substrate, wherein the substrate is formed of the bubble-containing viscoelastic composition according to claim 9. Adhesive tape or sheet.

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