JP2007051222A - Adhesive sheet for removing solvent-containing substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet for removing solvent-containing substance, having a highly cohesive adhesive layer, excellent in solvent absorption amount, having excellent adhesion after solvent absorption, and excellent in performance of removing the solvent-containing substance. <P>SOLUTION: The adhesive sheet for removing solvent-containing substance comprises a substrate and an adhesive layer formed on at least one surface of the substrate, and the adhesive layer contains at least a foamed adhesive layer comprising a composition composed of (A) an acrylic polymer, (B) a foaming agent and (C) a crosslinking agent, wherein the foaming agent (B) is foamed and the foamed adhesive layer surface forms an adhesive surface. The foamed adhesive layer is preferably formed by foaming treatment after crosslinking treatment. The crosslinking agent (C) is preferably a metal chelate-based crosslinking agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solvent-containing material-removing pressure-sensitive adhesive sheet used for cleaning (removing) various solvent-containing materials such as pastes and inks, and in particular, manufacturing a phosphor layer incorporated in a plasma display panel ( For example, the present invention relates to a solvent-containing material-removing pressure-sensitive adhesive sheet that is used as a cleaning pressure-sensitive adhesive sheet for removing a solvent-containing material when manufactured by a screen printing method or a dispenser method.

  Solvent-containing materials such as semi-solid materials containing solvents such as paste and ink are widely used in the fields of printing, paints, adhesives and the like. However, if such a solvent-containing substance is excessively present at a predetermined site or is present at an unnecessary site, it contaminates machinery, equipment, hands, etc., impairs product quality, Various problems such as clogging in the mouth are likely to occur. For example, in screen printing, after a certain number of times of printing, paste (ink) on the screen printing plate turns back to contaminate the printed material, or bleeding occurs in the printed image, making accurate and beautiful printing impossible. It becomes a state.

  As a method for removing such a solvent-containing material, a method using an adhesive tape or a sheet is known (see Patent Documents 1 to 3).

  In addition, the optical film which has the adhesion layer containing an acrylic polymer and a polyfunctional metal chelate compound is known (refer patent document 4).

JP-A-6-23998 Japanese Patent No. 3573065 Japanese Patent Laid-Open No. 11-254656 Japanese Patent Laid-Open No. 2002-249752

  However, in the conventional adhesive sheet for removing solvent-containing material (adhesive tape or sheet used for washing or removing the solvent-containing material), the adhesive sheet for removing solvent-containing material having a foamed adhesive layer is sufficient. However, depending on the type of the solvent-containing material such as ink or paste, a problem may occur when cleaning or removing the solvent-containing material. This is presumably because the conventional adhesive sheet for removing a solvent-containing material having a foamed adhesive layer does not have a structure in which the foamed adhesive layer is crosslinked by a crosslinking agent.

  In addition, an adhesive tape or sheet having an adhesive layer containing an acrylic polymer and a polyfunctional metal chelate compound is known, as described in JP-A-2002-249752, and the like. Although attempts were made to wash or remove solvent-containing materials such as ink and paste using an adhesive tape or sheet, it was not possible to sufficiently remove solvent-containing materials such as ink and paste.

  Therefore, the object of the present invention is that the pressure-sensitive adhesive layer has a high cohesive force, and has an excellent solvent absorption, and further has a high adhesive force after solvent absorption and a solvent-containing content removal performance. The object is to provide an adhesive sheet for removing objects.

  As a result of intensive studies to achieve the above object, the present inventor used a solvent-containing material removal pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer composed of a specific composition as the solvent-containing material removal pressure-sensitive adhesive sheet. The layer can exhibit good cohesive strength and has excellent solvent absorption, and even after absorption of the solvent, can exhibit good adhesive strength, and removes solvent-containing materials with excellent removal performance. And it discovered that a cleaning target object can be washed effectively. The present invention has been completed based on these findings.

  That is, the present invention relates to a solvent-containing material-removing pressure-sensitive adhesive sheet having a base material and a pressure-sensitive adhesive layer formed on at least one surface of the base material, wherein the pressure-sensitive adhesive layer is (A) an acrylic polymer. And (B) a foamed pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing a foaming agent and (C) a crosslinking agent and having a foamed foaming agent (B). A pressure-sensitive adhesive sheet for removing a solvent-containing material, characterized in that the surface is an adhesive surface.

  The foamed pressure-sensitive adhesive layer is preferably formed by performing a foaming process after a crosslinking process.

  In the pressure-sensitive adhesive composition for forming the foamed pressure-sensitive adhesive layer of the solvent-containing material-removing pressure-sensitive adhesive sheet, the acrylic polymer (A) is an acrylic polymer having (meth) acrylic acid alkyl ester as a main monomer component. Polymers are suitable, thermally expandable microcapsules are suitable as the foaming agent (B), and metal chelate-based crosslinking agents are suitable as the crosslinking agent (C).

  The solvent-containing material removing pressure-sensitive adhesive sheet can be suitably used as a pressure-sensitive adhesive sheet for cleaning a screen printing plate.

  According to the pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention, the pressure-sensitive adhesive layer has a high cohesive force, excellent solvent absorption, and further has a pressure-sensitive adhesive force after absorption of the solvent. The removal performance of the solvent-containing material is excellent.

  Embodiments of the present invention will be described below in detail with reference to the drawings as necessary. In addition, the same code | symbol may be attached | subjected to the same member, a site | part, etc.

  The pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention has a base material and a pressure-sensitive adhesive layer formed on at least one surface of the base material, as shown in FIGS. And the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing (A) an acrylic polymer, (B) a foaming agent, and (C) a crosslinking agent, and the foaming agent (B) is foamed. The foaming adhesive layer which has at least is contained, and the said foaming adhesive layer surface is an adhesive surface. FIG. 1 is a schematic cross-sectional view showing an example of the adhesive sheet for removing a solvent-containing material of the present invention. 1A and 1B, 1a and 1b are respectively a pressure-sensitive adhesive sheet for removing a solvent-containing material, 2 is a base material, 3a and 3b are pressure-sensitive adhesive layers, and 3a1 is a foamed pressure-sensitive adhesive layer and 3b1. Is a foamed adhesive layer, and 3b2 is a non-foamed adhesive layer. The foaming pressure-sensitive adhesive layer 3a1 and the foaming pressure-sensitive adhesive layer 3b1 are formed of a pressure-sensitive adhesive composition containing (A) an acrylic polymer, (B) a foaming agent, and (C) a crosslinking agent, and the foaming agent (B ) Is a pressure-sensitive adhesive layer having a foamed structure. On the other hand, the non-foamed pressure-sensitive adhesive layer 3b2 is a pressure-sensitive adhesive layer that does not contain a foaming agent and has a structure that is not foamed. A solvent-containing material-removing pressure-sensitive adhesive sheet 1a shown in FIG. 1 (a) has a pressure-sensitive adhesive layer 3a composed of only a foamed pressure-sensitive adhesive layer 3a1 on one surface of a substrate 2. Moreover, the adhesive sheet 1b for solvent content removal shown by FIG.1 (b) is the adhesive layer 3b comprised by the one side of the base material 2 by the foaming adhesive layer 3b1 and the non-foaming adhesive layer 3b2. have. The pressure-sensitive adhesive layer 3b contains a foamed pressure-sensitive adhesive layer 3b1 and a non-foamed pressure-sensitive adhesive layer 3b2 in a form in which the surface of the foamed pressure-sensitive adhesive layer 3b1 is an adhesive surface.

  Thus, in the pressure-sensitive adhesive sheet for removing a solvent-containing material, the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing (A) an acrylic polymer, (B) a foaming agent, and (C) a cross-linking agent. ) Is used, and a pressure-sensitive adhesive layer containing at least a foamed pressure-sensitive adhesive layer in a form in which the surface is used as an adhesive surface is used. It is important that the foamed pressure-sensitive adhesive layer has a structure crosslinked with a crosslinking agent (C). Therefore, the pressure-sensitive adhesive sheet for removing the solvent-containing material can exhibit the excellent cohesive force of the pressure-sensitive adhesive layer, can absorb the solvent with an excellent solvent absorption amount, and is excellent even after absorption of the solvent. Adhesive strength can be exhibited, and the solvent-containing material removal performance (cleaning performance) is excellent.

[Base material]
In the pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention, the substrate is not particularly limited. For example, when it is desired to avoid mixing of dust and foreign matter, a polyolefin film such as a polyethylene film or a polypropylene film; a polyethylene terephthalate film or the like A plastic film such as a polyester film can be suitably used without the risk of generating paper dust. Note that paper or the like can also be used as the base material when used simply for cleaning the roll. For the purpose of removing the paste and ink on the uneven surface, a foam made of polyurethane, polyethylene, EPDM (ethylene-propylene-diene rubber) or the like can also be suitably used as the substrate. Furthermore, depending on the application, it is also possible to use a nonwoven fabric, cloth, metal foil, or the like as the base material.

  The plastic material constituting the plastic film is not particularly limited as long as it can be formed in a sheet form or a film form. For example, polyethylene, polypropylene, poly-1-butene , Poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl alcohol copolymer Polyolefins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc. Polyacrylates, polystyrene, polyamides such as polyamide 6, polyamide 6,6 and partially aromatic polyamides, polyvinyl chloride, polyvinylidene chloride, polycar Sulfonate and the like. A plastic material can be used individually or in combination of 2 or more types. The plastic substrate may have any of a stretched form and an unstretched form.

  The thickness of the substrate is not particularly limited and can be appropriately selected in consideration of strength, workability, and the like. For example, the thickness is 10 to 500 μm (preferably 12 to 300 μm, more preferably 15 to 100 μm). It can be selected appropriately. When the base material is a foam, the thickness of the base material is generally several mm to several tens mm.

  The substrate may have any form of a single layer or a multilayer. As the base material, depending on the type of base material, etc., if necessary, release agents (silicone release agents, fluorine release agents, long-chain alkyl release agents, fatty acid amide release agents, etc.), silica powder, etc. Mold release treatment; antifouling treatment; easy adhesion treatment such as acid treatment, alkali treatment, primer treatment, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment; antistatic agent (coating type antistatic agent, kneading type antistatic agent) , An antistatic treatment with a vapor deposition type antistatic agent, etc.) may be performed.

  In addition, the base material may contain additives such as an antioxidant, an anti-aging agent, an ultraviolet absorber, a plasticizer, a softener, a colorant, and a filler as necessary.

[Adhesive layer]
In the pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention, the pressure-sensitive adhesive layer contains at least a foamed pressure-sensitive adhesive layer in such a form that the surface is used as a pressure-sensitive adhesive surface. Accordingly, as the layer structure of the pressure-sensitive adhesive layer, for example, as shown in FIG. 1A or FIG. 1B, the layer structure of a single-layer structure formed by only the foamed pressure-sensitive adhesive layer, the foamed pressure-sensitive adhesive layer Is a two-layer structure formed on the non-foamed pressure-sensitive adhesive layer.

(Foamed adhesive layer)
The foamed pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing (A) an acrylic polymer, (B) a foaming agent, and (C) a crosslinking agent, and the foaming agent (B) is foamed. That is, the said foaming adhesive layer is an adhesive layer containing the foaming foaming agent (B). Accordingly, the foamed pressure-sensitive adhesive layer contains bubbles (closed cells, open cells, etc.). It is important that the foamed pressure-sensitive adhesive layer is crosslinked with the crosslinking agent (C) as described above.

  The acrylic polymer (A) is not particularly limited as long as it is an acrylic polymer containing an acrylic monomer as a monomer component, but an acrylic polymer having a (meth) acrylic acid alkyl ester as a main monomer component (monomer main component). A polymer can be suitably used. Examples of the alkyl (meth) acrylate as the main monomer component of the acrylic polymer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acryl N-undecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, n-pentadecyl (meth) acrylate, n-hexadecyl (meth) acrylate N-heptadecyl (meth) acrylate, n-octadecyl (meth) acrylate, n-nonadecyl (meth) acrylate, n-eicosyl (meth) acrylate, and the like. The (meth) acrylic acid alkyl ester can be used alone or in combination of two or more.

  In addition, the monomer component (copolymerizable monomer component) which can be copolymerized with the said (meth) acrylic-acid alkylester may be used as a monomer component for comprising an acrylic polymer. Examples of such copolymerizable monomer components include carboxyl group-containing monomers such as (meth) acrylic acid (acrylic acid, methacrylic acid), itaconic acid, maleic acid, fumaric acid, and crotonic acid, and those carboxyl group-containing monomers. Monomeric acid anhydrides (eg, monomeric acid group-containing monomers such as maleic anhydride and icotanic anhydride); 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid Hydroxyl group-containing monomers such as 4-hydroxybutyl; epoxy group-containing monomers such as glycidyl (meth) acrylate; amino group-containing monomers such as N, N-dimethylaminoethyl (meth) acrylate; (meth) acrylamide, N- Amide group-containing monomers such as methylol (meth) acrylamide; (meth) a Cyano group-containing monomers such as rilonitrile (acrylonitrile, methacrylonitrile); vinyl esters such as vinyl acetate and vinyl propionate; styrene monomers such as styrene, α-methylstyrene, vinyltoluene; methoxyethyl (meth) acrylate, (Meth) alkoxy group-containing monomers such as ethoxyethyl acrylate; olefin monomers such as ethylene, propylene, isoprene and butadiene; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; halogen atom-containing monomers such as vinyl chloride; (Meth) acrylic acid cycloalkyl ester such as cyclohexyl acrylate; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate and the like. Examples of the copolymerizable monomer include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, Polyfunctional monomers such as divinylbenzene, butyl di (meth) acrylate, and hexyl di (meth) acrylate can also be used.

  A copolymerizable monomer can be used individually or in combination of 2 or more types. As the copolymerizable monomer, a functional group-containing copolymerizable monomer having a functional group capable of reacting with the crosslinking agent (C) (carboxyl group, hydroxyl group, amino group, group having an amide bond, etc.) is preferably used. it can. Examples of such a functional group-containing copolymerizable monomer include a monomer having a hydroxyl group, an amino group, and an amide group (group having an amide bond) in addition to a carboxyl group-containing monomer or its anhydride. However, a carboxyl group-containing monomer (particularly acrylic acid or methacrylic acid) can be suitably used.

  Thus, in the acrylic polymer (A), it is important that the functional group-containing copolymerizable monomer is used together with the (meth) acrylic acid alkyl ester. The amount of (meth) acrylic acid alkyl ester and functional group-containing copolymerizable monomer used is not particularly limited, and is appropriately selected depending on the type of solvent-containing material to be removed (the type of solid and the type of solvent). can do. The ratio of the (meth) acrylic acid alkyl ester may be 50% by weight or more, preferably 80 to 99.5% by weight (more preferably 90 to 99% by weight), based on the total amount of the monomer components. Further, the ratio of the functional group-containing copolymerizable monomer may be less than 50% by weight, preferably 0.5 to 20% by weight (more preferably 1 to 10% by weight), based on the total amount of the monomer components. .

  The weight average molecular weight (Mw) of the acrylic polymer (A) is not particularly limited, and may be 300,000 to 2.5 million, for example.

  The acrylic polymer (A) can be suitably prepared by a radical polymerization method using a radical polymerization initiator. The radical polymerization initiator is not particularly limited, and can be appropriately selected from known radical polymerization initiators such as an azo radical polymerization initiator and a peroxide radical polymerization initiator. The reaction temperature for preparing the acrylic polymer (A) is usually 50 to 85 ° C., and the reaction time is usually 1 to 8 hours.

  The acrylic polymer (A) can be prepared by a known polymerization method (for example, a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, etc.), and particularly prepared by a solution polymerization method. Is preferred. As a solvent for preparing the acrylic polymer (A) by a solution polymerization method, a polar solvent such as ethyl acetate or toluene is generally used. In addition, the density | concentration of the monomer component in the solution at the time of preparing an acrylic polymer (A) with a solution polymerization method shall be 20 to 80 weight% normally.

  The foaming agent (B) (unfoamed foaming agent) is not particularly limited, and a known foaming agent can be used, but a heat-foaming foaming agent that foams by heating is preferable. Capsules (thermally expandable microspheres) can be preferably used. A foaming agent (B) can be used individually or in combination of 2 or more types. The thermally expandable microcapsule as the foaming agent (B) is not particularly limited as long as it has a function of causing a foaming phenomenon under a set heating condition. More specifically, as a thermally expandable microcapsule, a substance that easily vaporizes and expands when heated (for example, a volatile gas such as a low-boiling hydrocarbon such as isobutane, propane, or pentane) has an elastic shell. A microsphere (microcapsule) encapsulated in can be suitably used. The shell is often formed of a hot-melt material or a material that is destroyed by thermal expansion. Examples of the material forming the shell include, for example, vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone, methyl methacrylate-acrylonitrile copolymer, methyl methacrylate- Examples include acrylonitrile-methylolacrylamide copolymer. The thermally expandable microcapsule can be produced by a known or conventional method (for example, a coacervation method, an interfacial polymerization method, an insight polymerization method, or the like).

  In addition, as the thermally expandable microcapsule as the foaming agent (B), for example, a series of trade names “Matsumoto Microsphere” manufactured by Matsumoto Yushi Seiyaku Co., Ltd. (for example, trade name “Matsumoto Microsphere F30”, etc.) In addition, commercially available products such as trade names “051DU”, “053DU”, “551DU”, “551-20DU”, and “551-80DU” manufactured by EXPANSEL can be used.

  In the present invention, as the foaming agent (B), a foaming agent other than the thermally expandable microcapsule can also be used. As such a foaming agent, various foaming agents such as various inorganic foaming agents and organic foaming agents can be appropriately selected and used. Typical examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, various azides and the like. Representative examples of organic foaming agents include, for example, water; chlorofluorinated alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azobisisobutyronitrile, azodicarbonamide, and barium azodi. Azo compounds such as carboxylate; hydrazine compounds such as p-toluenesulfonyl hydrazide, diphenylsulfone-3,3'-disulfonyl hydrazide, 4,4'-oxybis (benzenesulfonyl hydrazide), allyl bis (sulfonyl hydrazide); p- Semicarbazide compounds such as toluylenesulfonyl semicarbazide and 4,4′-oxybis (benzenesulfonyl semicarbazide); Triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; N, N′-dinitrosopene Methylene terrorism Ramin, N, N'-dimethyl -N, N'N-nitroso compounds such as dinitrosoterephthalamide, and the like.

  The particle size (average particle size) of the foaming agent (B) (unfoamed foaming agent) can be appropriately selected according to the thickness of the foamed adhesive layer. The average particle diameter of the foaming agent (B) can be selected from the range of, for example, 100 μm or less (preferably 80 μm or less, more preferably 10 to 50 μm, particularly 10 to 30 μm).

  The foaming start temperature of the heat-foamable foaming agent (particularly the thermally expandable microcapsule) as the foaming agent (B) can be appropriately selected from the range of 80 ° C to 210 ° C, for example.

  In addition, although it does not restrict | limit especially as foaming or expansion | swelling magnification of a foaming agent (B) (especially thermally expansible microcapsule), For example, it is preferable that it is 2-30 times (especially 3-20 times). That is, as the foaming agent (B), it is preferable to use a foaming agent that can be expanded to a volume of 2 to 30 times (particularly 3 to 20 times) the volume before foaming (original volume). . If the expansion ratio of the foaming agent (B) is less than 2 times, the amount of solvent absorbed by the foamed adhesive layer is unfavorable. On the other hand, when the expansion ratio of the foaming agent (B) exceeds 30 times, the adhesive strength by the foamed adhesive layer is lowered, which is not preferable.

  The amount of the foaming agent (B) used can be appropriately set according to the expansion ratio of the foaming agent (B), the adhesive strength of the foaming adhesive layer, etc. For example, the amount of the adhesive in the foaming adhesive layer Acrylic polymer (A) as the base polymer: for example, selected from the range of 1 to 50 parts by weight (preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight) with respect to 100 parts by weight. it can. When the amount of the foaming agent (B) used is less than 1 part by weight relative to 100 parts by weight of the acrylic polymer (A), the amount of solvent absorbed by the foamed adhesive layer decreases, while 50 parts by weight is reduced. When it exceeds, the adhesive force by a foaming adhesive layer will fall.

  The crosslinking agent (C) is not particularly limited, and can be appropriately selected from known crosslinking agents. The crosslinking agent (C) may be either a water-soluble crosslinking agent or an oil-soluble crosslinking agent, and can be appropriately selected according to the type of the pressure-sensitive adhesive in the foamed pressure-sensitive adhesive layer. A crosslinking agent (C) can be used individually or in combination of 2 or more types. Specifically, examples of the crosslinking agent (C) include metal chelate crosslinking agents, isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, carbodiimide crosslinking agents, and active methylol crosslinking agents. Agent, active alkoxymethyl crosslinking agent, metal alkoxide crosslinking agent, metal salt crosslinking agent, peroxide crosslinking agent, melamine crosslinking agent, urea crosslinking agent, amino crosslinking agent, carboxylic acid or acid anhydride system Examples thereof include a crosslinking agent and a coupling agent-based crosslinking agent (such as a silane coupling agent).

  In the situation where the crosslinking reaction by the crosslinking agent (C) is not sufficiently progressed, if the pressure-sensitive adhesive layer is expanded to form a foamed pressure-sensitive adhesive layer, the cohesive force of the foamed pressure-sensitive adhesive layer may be impaired. As the agent (C), a crosslinking agent having a high crosslinking reaction rate can be suitably used. Thus, productivity of the adhesive sheet for solvent content removal can also be improved by using a crosslinking agent with a quick crosslinking reaction rate as a crosslinking agent (C). However, even if the crosslinking agent has a slow crosslinking reaction rate, the foamed pressure-sensitive adhesive layer is sufficiently aged to advance the crosslinking reaction before the pressure-sensitive adhesive layer is expanded to form the foamed pressure-sensitive adhesive layer. Therefore, it is possible to use a crosslinking agent having a slow crosslinking reaction rate.

  Thus, in this invention, since the crosslinking agent (C) is used in order to raise the cohesion force of a foaming adhesive layer, a foaming adhesive layer has the structure bridge | crosslinked by the crosslinking agent (C). It is important that Therefore, it is important that a functional group capable of reacting with the crosslinking agent (C) is introduced into the acrylic polymer (A).

  As the crosslinking agent (C), a metal chelate crosslinking agent can be suitably used from the viewpoint of the crosslinking reaction rate and the like. The metal chelate-based crosslinking agent is a compound having polyfunctionality and having a polyvalent metal atom bonded to an organic compound (chelating agent) (such as a covalent bond or a coordinate bond). In the metal chelate-based crosslinking agent, examples of the polyvalent metal atom include group 2 elements of the periodic table such as magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba); scandium (Sc), yttrium ( Y), lanthanoid elements [lanthanum (La), cerium (Ce), etc.], periodic table group 3 elements such as actinoid elements [actinium (Ac), etc.]; periodic table group 4, such as titanium (Ti) and zirconium (Zr) Elements; Group 5 elements of the periodic table such as vanadium (V), niobium (Nb), tantalum (Ta); Group 6 elements of the periodic table such as chromium (Cr), molybdenum (Mo), tungsten (W); Manganese (Mn) Periodic table group 7 elements such as iron (Fe) periodic table group 8 elements; cobalt (Co) and other periodic table group 9 elements; nickel (Ni), palladium (Pd) Periodic table group 10 elements such as platinum (Pt); periodic table group 11 elements such as copper (Cu), silver (Ag) and gold (Au); periodic table group 12 elements such as zinc (Zn); aluminum (Al) And periodic table group 13 elements such as gallium (Ga) and indium (In); and periodic table group 14 elements such as tin (Sn) and lead (Pb). In the metal chelate-based crosslinking agent, polyvalent metal atoms can be used alone or in combination of two or more. As the polyvalent metal atom, aluminum, zirconium and titanium are preferable, and aluminum can be particularly preferably used.

  Accordingly, examples of the metal chelate crosslinking agent include an aluminum chelate crosslinking agent, a zirconium chelate crosslinking agent, a titanium chelate crosslinking agent, a chromium chelate crosslinking agent, a cobalt chelate crosslinking agent, a copper chelate crosslinking agent, and an iron chelate. Crosslinker, nickel chelate crosslinker, vanadium chelate crosslinker, zinc chelate crosslinker, indium chelate crosslinker, calcium chelate crosslinker, magnesium chelate crosslinker, manganese chelate crosslinker, yttrium chelate crosslinker Agents, cerium chelate crosslinking agents, strontium chelate crosslinking agents, barium chelate crosslinking agents, molybdenum chelate crosslinking agents, lanthanum chelate crosslinking agents, tin chelate crosslinking agents, etc., preferably aluminum chelate crosslinking agents Agent, zirco Umukireto based crosslinking agent, a titanium chelate crosslinking agent (more preferably an aluminum chelate crosslinking agent) is.

On the other hand, in the metal chelate-based crosslinking agent, the atom in the chelating agent that binds to the polyvalent metal atom is not particularly limited, but an oxygen atom is preferable. Therefore, examples of the chelating agent include ester compounds, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds. More specifically, examples of the chelating agent include β-dicarbonyl compounds [for example, acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 2,4-octane. Β-diketones such as dione, 3,5-octanedione, 2,4-nonanedione, 3,5-nonanedione, 5-methyl-2,4-hexanedione; methyl acetoacetate, ethyl acetoacetate, propylacetoacetate, Β-ketoesters such as isopropyl acetoacetate, butyl acetoacetate, isobutyl acetoacetate, s-butyl acetoacetate, t-butyl acetoacetate, 2-ethylhexyl acetoacetate, dodecyl acetoacetate (eg acetoacetic acid C _1-20 alkyl ester) ; Β-diesters such as diethyl malonate] and the like, and a hydroxyl group or amino group at the β-position. That carbonyl compounds (e.g., diacetone alcohol, diacetone amine, salicylaldehyde, methyl salicylate, N- methyl salicylamide, etc.) and the like. A chelating agent may be used independently and may be used in combination of multiple.

  Therefore, when the metal chelate crosslinking agent is, for example, an aluminum chelate crosslinking agent in which the polyvalent metal atom is aluminum, examples of the aluminum chelate crosslinking agent include aluminum tris (acetylacetonate) and aluminum tris (propionylacetonate). Aluminum tris (acyl acetonate) such as aluminum tris (ethyl acetoacetate), aluminum tris (acetoacetic acid alkyl ester) such as aluminum tris (t-butyl acetoacetate); Aluminum mono (acetylacetonate) bis (ethyl aceto) Acetate), aluminum mono (acetylacetonate) bis (isobutylacetoacetate), aluminum mono (acetylacetonate) bis (2-ethylhexylacetoacetate), aluminum Aluminum [(mono or bis) (acetylacetonate)] [(bis or mono) (acetoacetic acid alkyl ester)]; (acetylacetonate) aluminum diisopropylate such as nium mono (acetylacetonate) bis (dodecylacetoacetate) [(Mono or bis) (acyl acetonate)] aluminum [(di or mono) alcoholate]; (ethyl acetoacetate) aluminum diisopropylate, bis (ethyl acetoacetate), bis (acetylacetonate) aluminum monoisopropylate, etc. And [(mono or bis) (acetoacetic acid alkyl ester)] aluminum [(di or mono) alcoholate] such as aluminum monoisopropylate. As the aluminum chelate-based crosslinking agent, aluminum tris (acetylacetonate) and aluminum tris (ethyl acetoacetate) are preferable.

  Moreover, as a metal chelate type crosslinking agent (zirconium chelate type crosslinking agent, a titanium chelate type crosslinking agent, etc.) other than an aluminum chelate type crosslinking agent, what respond | corresponded to the aluminum chelate type crosslinking agent illustrated above, etc. are mentioned.

  In addition, when using crosslinking agents other than a metal chelate type crosslinking agent as a crosslinking agent (C), an isocyanate type crosslinking agent and an epoxy-type crosslinking agent can be used suitably. In addition, the metal chelate crosslinking agent may be used in combination with other crosslinking agents (such as isocyanate crosslinking agents and epoxy crosslinking agents). Examples of the isocyanate-based crosslinking agent include aliphatic polyisocyanates (for example, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, lysine diisocyanate, etc.), Alicyclic polyisocyanates (for example, cyclopentyl diisocyanate, cyclohexyl diisocyanate, isophorone diisocyanate, etc.), aromatic polyisocyanates (for example, 2,4-tolylene diisocyanate, 4,4′-diphenylmethane) Diisocyanates, etc.), araliphatic polyisocyanates (for example, xylylene-1,4-diisocyanate, etc.), aliphatic polyisocyanates exemplified above, alicyclic polyisocyanates, aromatic Double bodies of polyisocyanates, araliphatic polyisocyanates, Polymer, reaction product or polymer [for example, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane / hexamethylene diisocyanate trimer addition Products (trade name “Coronate HL” manufactured by Nippon Polyurethane Industry Co., Ltd.), isocyanurate of hexamethylene diisocyanate (trade name “Coronate HX” manufactured by Japan Polyurethane Industry Co., Ltd.), etc.], polyether polyisocyanate, polyester polyisocyanate Etc. Examples of the epoxy-based crosslinking agent include polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, glycerin diglycidyl ether, diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, N, N, N ′, N ′. -Tetraglycidyl-m-xylenediamine (trade name “TETRAD-X” manufactured by Mitsubishi Gas Chemical Co., Ltd.), 1,3-bis (N, N-glycidylaminomethyl) cyclohexane (trade name “TETRAD-C” Mitsubishi Gas, Inc.) Chemical Co., Ltd.), 1,6-hexanediol diglycidyl ether, and various epoxy resins.

  The amount used (solid content) of the crosslinking agent (C) (particularly metal chelate crosslinking agent such as aluminum chelate crosslinking agent) is cohesive force, heat resistance, flexibility, adhesiveness, acrylic polymer to be crosslinked (A ) And the use as a pressure-sensitive adhesive sheet for removing a solvent-containing material, and the like. For example, acrylic polymer (A): 0.01 to 6 parts by weight (preferably 100 parts by weight) Can be selected from the range of 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight.

  In the pressure-sensitive adhesive composition constituting the foamed pressure-sensitive adhesive layer, various known additives [e.g., tackifier, plasticizer, together with acrylic polymer (A), foaming agent (B) and cross-linking agent (C) , Softeners, fillers, colorants (such as pigments and dyes), anti-aging agents, antioxidants, UV absorbers, corrosion inhibitors, leveling agents, surface lubricants, polymerization inhibitors, silane coupling agents, antistatic Agents, surfactants, etc.] may be included. Examples of tackifiers include terpene resins (terpene resins, terpene phenol resins, aromatic modified terpene resins, hydrogenated terpene resins, etc.), petroleum resins (aliphatic, aromatic, alicyclic). Rosin resin (rosin, hydrogenated rosin ester, etc.), coumarone-indene resin, phenol resin, styrene resin and the like. Examples of the surfactant include anionic surfactants such as phosphate ester, sulfate ester, sulfonic acid and carboxylic acid; cationic surfactants such as amine salt and quaternary ammonium salt. Agents: Nonionic surfactants such as ester, ether, ester ether and alkanolamides; amphoteric surfactants such as carboxybetaine and glycine.

  The amount of these additives used is not particularly limited, and can be appropriately selected within a range that does not impair the adhesiveness or solvent absorbability of the foamed adhesive layer.

  The pressure-sensitive adhesive composition constituting the foamed pressure-sensitive adhesive layer may be any pressure-sensitive adhesive composition such as a solvent-based pressure-sensitive adhesive composition or an emulsion-based pressure-sensitive adhesive composition.

  As thickness of a foaming adhesive layer, it can select from the range of 10-1000 micrometers (preferably 20-500 micrometers, more preferably 50-300 micrometers), for example. The thickness of the unfoamed pressure-sensitive adhesive layer when forming the foamed pressure-sensitive adhesive layer (thickness of the unfoamed pressure-sensitive adhesive layer) is, for example, in the range of about 5 to 300 μm (preferably 10 to 50 μm). You can choose. The foamed pressure-sensitive adhesive layer may have either a single layer or multiple layers.

  As a manufacturing method of a foaming adhesive layer, especially if it is a method which can manufacture the foaming adhesive layer which is formed with the said adhesive composition and has the structure by which the foaming agent (B) was foamed, it is a method. Although it does not restrict | limit, in order to exhibit the outstanding cohesion force to a foaming adhesive layer, it is preferable to perform foaming of a foaming agent (B), after bridge | crosslinking an acrylic polymer (A) with a crosslinking agent (C). That is, the foamed pressure-sensitive adhesive layer can be formed by performing a crosslinking treatment and crosslinking with the crosslinking agent (C), and then performing a foaming treatment and foaming with the foaming agent (B). In this way, after the crosslinking reaction with the crosslinking agent (C) is advanced to a predetermined level, the foaming agent (B) is foamed so as to have a predetermined expansion ratio. A foamed pressure-sensitive adhesive layer can be formed.

  Therefore, as a manufacturing method of a foaming adhesive layer, the manufacturing method formed by giving a foaming process after giving a crosslinking process is preferable. Specifically, for example, a pressure-sensitive adhesive composition containing an acrylic polymer (A), a foaming agent (B), and a crosslinking agent (C) is applied on a predetermined surface (on a base material or a non-foamed pressure-sensitive adhesive layer). ), Dried and cured, and subjected to a crosslinking treatment for crosslinking with a crosslinking agent (C), followed by a foaming treatment for foaming with a foaming agent (B) by heat treatment, etc. An agent layer can be formed. It is important that the crosslinking with the crosslinking agent (C) proceeds to a predetermined level, and the degree of crosslinking of the crosslinking agent (C) can be controlled by the temperature and time during the crosslinking treatment. Moreover, in order to advance the bridge | crosslinking by a crosslinking agent (C) to a predetermined grade, you may perform aging. On the other hand, it is important that foaming with the foaming agent is performed so as to have a predetermined foaming ratio, and the foaming ratio of the foaming agent (B) can be controlled by the temperature and time during the foaming treatment.

(Non-foam adhesive layer)
The non-foaming pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer not containing a foaming agent, and is a known pressure-sensitive adhesive (for example, acrylic pressure-sensitive adhesive, rubber pressure-sensitive adhesive, silicone pressure-sensitive adhesive, vinyl alkyl ether pressure-sensitive adhesive, polyester). Based adhesives, polyamide adhesives, urethane adhesives, fluorine adhesives, etc.). The pressure-sensitive adhesive for forming the non-foamed pressure-sensitive adhesive layer can be used alone or in combination of two or more.

  As the pressure-sensitive adhesive for forming the non-foamed pressure-sensitive adhesive layer, an acrylic pressure-sensitive adhesive or a rubber pressure-sensitive adhesive (particularly an acrylic pressure-sensitive adhesive) can be suitably used. In addition, as an acrylic adhesive, the acrylic adhesive which uses the acrylic polymer which has (meth) acrylate as a monomer main component as a base polymer can be used suitably. Examples of such an acrylic pressure-sensitive adhesive include a pressure-sensitive adhesive composition obtained by removing the foaming agent (B) from the pressure-sensitive adhesive composition forming the foamed pressure-sensitive adhesive layer. Rubber-based adhesives include natural rubber, styrene-isoprene-styrene block copolymer (SIS block copolymer), styrene-butadiene-styrene block copolymer (SBS block copolymer), styrene-ethylene, Rubber-based pressure-sensitive adhesives based on rubber components such as butylene-styrene block copolymer (SEBS block copolymer), styrene-butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, silicone rubber, etc. Can be mentioned.

  The pressure-sensitive adhesive composition constituting the non-foamed pressure-sensitive adhesive layer may contain a crosslinking agent. Therefore, the non-foaming pressure-sensitive adhesive layer may have a configuration crosslinked by a crosslinking agent. As such a crosslinking agent, it can select from the crosslinking agent illustrated as a crosslinking agent (C) suitably, and can be used.

  Further, in the pressure-sensitive adhesive composition constituting the non-foamed pressure-sensitive adhesive layer, various known additives [e.g., tackifier, plasticizer, softening, as well as the pressure-sensitive adhesive composition constituting the foamed pressure-sensitive adhesive layer] Agent, filler, colorant (pigment, dye, etc.), anti-aging agent, antioxidant, UV absorber, corrosion inhibitor, leveling agent, surface lubricant, polymerization inhibitor, silane coupling agent, antistatic agent, Surfactant etc.] may be contained.

  The thickness of the non-foaming pressure-sensitive adhesive layer is not particularly limited, and can be selected from a range of 1 to 100 μm (preferably 1 to 50 μm), for example. The non-foaming pressure-sensitive adhesive layer may have any form of a single layer or multiple layers.

  The non-foamed pressure-sensitive adhesive layer can be formed using a known method for forming a pressure-sensitive adhesive layer. Specifically, a pressure-sensitive adhesive is applied on a predetermined surface of a substrate, dried and / or cured to form a non-foamed pressure-sensitive adhesive layer, or a pressure-sensitive adhesive is applied to a separator and non-foamed. After forming the foamed pressure-sensitive adhesive layer, the non-foamed pressure-sensitive adhesive layer is formed on at least one surface of the substrate by using a method of forming the non-foamed pressure-sensitive adhesive layer by transferring it onto a predetermined surface of the substrate. Can be formed.

  The pressure-sensitive adhesive layer (foamed pressure-sensitive adhesive layer or non-foamed pressure-sensitive adhesive layer) may be formed on the substrate via another layer as long as the effects of the present invention are not impaired.

[Solvent-containing adhesive sheet]
The pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention has a base material and a pressure-sensitive adhesive layer formed on at least one surface of the base material. That is, the solvent-containing material-removing pressure-sensitive adhesive sheet has a structure in which a pressure-sensitive adhesive layer is formed on one side of a base material (single-sided pressure-sensitive adhesive sheet with a base material) and a structure in which pressure-sensitive adhesive layers are formed on both sides of the base material. Any of an adhesive sheet (double-sided adhesive sheet with a base material) may be sufficient. The solvent-containing material-removing pressure-sensitive adhesive sheet of the present invention preferably has a structure in which a pressure-sensitive adhesive layer is formed on one side of the substrate.

  In addition, the surface (adhesive surface) of the adhesive layer may be protected by a separator (release liner). The separator is not particularly limited and can be appropriately selected from known separators. As the separator, a substrate having a release treatment layer with a release treatment agent on at least one surface can be suitably used, and a fluorine-based polymer (for example, 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 substrate made of a resin or the like can also be used.

  When the separator has a configuration in which a release treatment layer is formed on at least one surface of the base material, the base material of the separator may be papers, cloths, etc. From the viewpoint of superiority, a plastic sheet or films can be preferably used. The plastic sheet or film as the substrate of the separator is not particularly limited, and for example, a polyethylene sheet or film, a polypropylene sheet or film, a polybutene sheet or film, a polybutadiene sheet or film, a polymethylpentene sheet or film, polychlorinated Examples thereof include a vinyl sheet or film, a polyvinyl chloride copolymer sheet or film, a polyethylene terephthalate sheet or film, a polybutylene terephthalate sheet or film, a polyurethane sheet or film, and an ethylene-vinyl acetate copolymer sheet or film. The thickness of the base material of the separator is usually 5 to 200 μm (preferably 10 to 100 μm).

  Further, as a release treatment agent for forming a release treatment layer, a known or commonly used release treatment agent (silicone release treatment agent, fluorine release treatment agent, long chain alkyl release treatment agent, fatty acid amide release treatment agent, Silica powder etc. can be used.

  The pressure-sensitive adhesive sheet for removing a solvent-containing material may have other layers (for example, an intermediate layer, an undercoat layer, etc.) as long as the effects of the present invention are not impaired. Such a layer such as an undercoat layer or an intermediate layer can be formed between the substrate and the pressure-sensitive adhesive layer. Further, as described above, the solvent-containing material-removing pressure-sensitive adhesive sheet may have a printed layer. The printing layer can be formed between the substrate and the pressure-sensitive adhesive layer.

  In addition, when the pressure-sensitive adhesive sheet for removing a solvent-containing material has a configuration in which a pressure-sensitive adhesive layer is formed on one side of the base material, the back surface of the base material (on the opposite side to the surface on which the pressure-sensitive adhesive layer is formed) The back surface treatment layer may be formed on the surface. Such a back surface treatment layer is a known or commonly used back surface treatment agent (for example, silicone release agent, fluorine release agent, long-chain alkyl release agent, fatty acid amide release agent, silica powder, etc.). Can be formed.

  In this invention, the adhesive sheet for solvent content removal may be formed in the form wound by roll shape, and may be formed in the form by which the sheet | seat was laminated | stacked. That is, the adhesive sheet for removing a solvent-containing material of the present invention can have a form such as a sheet form or a tape form. In addition, when the pressure-sensitive adhesive sheet for solvent-containing material removal has a form wound in a roll shape, for example, the state in which the pressure-sensitive adhesive layer is protected by a release treatment layer formed on the back side of the separator or substrate By winding in a roll shape, a pressure-sensitive adhesive sheet for removing a solvent-containing material in a form wound in a roll shape can be produced.

  The pressure-sensitive adhesive sheet for removing the solvent-containing material forms a pressure-sensitive adhesive layer on at least one surface of the base material using a known or conventional method such as a coating method according to the layer structure and the like. It can be produced by forming an undercoat layer, a back treatment layer or the like on a predetermined surface. The method of applying the pressure-sensitive adhesive composition in forming the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include a roll coating method, a gravure coating method, a reverse coating method, a roll brush method, a spray coating method, and an air knife coating. The method of law etc. are mentioned.

  As described above, the pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention has a structure in which the pressure-sensitive adhesive layer is formed by a pressure-sensitive adhesive composition containing a crosslinking agent (C) (that is, crosslinked by the crosslinking agent (C)). The foamed pressure-sensitive adhesive layer having the structure) is contained at least in a form used as an adhesive surface, and thus an excellent cohesive force can be exhibited. The foamed pressure-sensitive adhesive layer has a structure formed of a pressure-sensitive adhesive composition containing (A) an acrylic polymer, (B) a foaming agent, and (C) a crosslinking agent, and the foaming agent (B) is foamed. Since it has such a configuration, the solvent absorption is excellent, and an excellent adhesive force can be exhibited even after solvent absorption. Therefore, the solvent-containing material removal pressure-sensitive adhesive sheet having such a pressure-sensitive adhesive layer is excellent in the solvent-containing material removal performance (cleaning performance).

[Solvent-containing material]
In the present invention, the solvent-containing material to be removed is not particularly limited, and examples thereof include semi-solid materials that contain a solvent and are in a wet state, such as pastes, inks, glues, adhesives, and paints. Specifically, examples of the solvent-containing material include paste (ink) used for screen printing and ink attached to rolls of a printing machine such as an offset printing machine.

  The adhesive sheet for solvent-containing material removal absorbs the solvent contained in the paste attached to the back side of the screen plate or the ink attached to the rolls, for example, by sticking it to the back side of the screen plate or rolls. Thus, the paste or the like can be solidified. Accordingly, the pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention is, for example, a paste (ink) that is turned around on the back side of a screen printing plate, an ink attached to a roll of a printing press such as offset printing, or an ink jet of an inkjet printer. It is suitable for removing ink stains near the mouth. That is, the pressure-sensitive adhesive sheet for removing a solvent-containing material of the present invention can be suitably used as a pressure-sensitive adhesive sheet for cleaning a screen printing plate.

  Examples of the solvent contained in the solvent-containing material such as paste and ink include aliphatic hydrocarbons such as hexane, heptane, and mineral spirit; alicyclic hydrocarbons such as cyclohexane; toluene, xylene, solvent naphtha, tetralin, and dipentene. Aromatic alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, s-butyl alcohol, cyclohexyl alcohol, 2-methylcyclohexyl alcohol, tridecyl alcohol, etc .; methyl acetate, ethyl acetate, acetic acid Esters such as isopropyl and butyl acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, diacetone alcohol, isophorone, etc. Ketones; glycols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol; glycol ethers such as butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether; butyl cellosolve acetate, Examples include glycol ether esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate; water and the like. In the case of screen printing ink, a medium boiling solvent (boiling point: about 120 to 230 ° C.) and a high boiling point solvent (boiling point: about 230 to 320 ° C.) are often used. For example, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether (For example, diethylene glycol monobutyl ether acetate / diethylene glycol monobutyl ether [9/1 (weight ratio)]) and the like.

  In the present invention, the adhesive sheet for removing the solvent-containing material is bonded to the back surface of the screen printing plate in a form in which the surface of the pressure-sensitive adhesive layer is in contact, and then peeled off to adhere to the back surface of the screen printing plate. The screen printing plate can be cleaned by removing the solvent-containing material.

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

(Acrylic polymer preparation example 1)
In a reaction vessel equipped with a cooling tube, a nitrogen introducing tube, a thermometer, a dropping funnel, and a stirring device, 2,2′-azobisisobutyronitrile as a polymerization initiator: 0.2 part by weight, and ethyl acetate as a solvent: 100 100 parts by weight of n-butyl acrylate and 5 parts by weight of acrylic acid were added as weight parts and monomer components, and nitrogen reflux was performed at room temperature for 1 hour. Thereafter, the temperature of the monomer composition solution containing the monomer component in the reaction vessel was raised to 60 ° C., and polymerization was performed in a nitrogen stream for 5.5 hours to obtain a solution containing an acrylic polymer.

The weight average molecular weight of the acrylic polymer was 500,000. The weight average molecular weight of the acrylic polymer is a value measured under the following measurement conditions by standard polystyrene conversion of gel permeation chromatography (GPC method).
Measurement conditions for GPC method GPC measurement device: trade name “HLC-8120GPC” (manufactured by Tosoh Corporation)
Column: 7.8 mmI. D. × 300mm
・ Flow rate (flow rate): 0.5 ml / min
・ Eluent: Tetrahydrofuran (THF)
Sample concentration: 1.0 g / l (tetrahydrofuran solution)
Sample injection volume: 100 μl
Column temperature (measurement temperature): 40 ° C

Example 1
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight, trade name “aluminum chelate A (W)” (manufactured by Kawaken Fine Chemicals; aluminum tris (acetylacetonate); 0.5 parts by weight, trade name “Matsumoto Microsphere F30” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd .; referred to as “foaming agent A” in Table 1): 5 parts by weight Then, a pressure-sensitive adhesive composition containing a foaming agent and a metal chelate-based crosslinking agent is prepared, and the pressure-sensitive adhesive composition is dried on one side of a polyethylene terephthalate substrate (thickness: 38 μm). After applying (unfoamed pressure-sensitive adhesive layer) to 40 μm, drying and curing to form an unfoamed pressure-sensitive adhesive layer, immediately after that, from the polyethylene terephthalate substrate side Under the conditions of 120 ° C. × 10 seconds, heat was applied and foamed to form a foamed pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet having a foamed pressure-sensitive adhesive layer was produced.

(Example 2)
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight, trade name “Coronate L” (manufactured by Nippon Polyurethane Industry Co., Ltd .; isocyanate crosslinking agent; referred to as “crosslinking agent B” in Table 1) ): 10 parts by weight was added to prepare an adhesive composition containing an isocyanate-based crosslinking agent, and the adhesive composition was dried on one side of a polyethylene terephthalate substrate (thickness: 38 μm). It apply | coated so that latter thickness might be set to 5 micrometers, it was made to dry and harden | cure, and the non-foaming adhesive layer was formed.

  Moreover, the product name “aluminum chelate A (W)” (manufactured by Kawaken Fine Chemical Co., Ltd .; “crosslinking agent A” in Table 1) with respect to 100 parts by weight of the acrylic polymer obtained in Preparation Example 1 of the acrylic polymer. : 0.5 parts by weight, trade name “Matsumoto Microsphere F30” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd .; “Foaming agent A” in Table 1): 5 parts by weight added, foaming agent and metal chelate crosslinking agent The pressure-sensitive adhesive composition was prepared on the non-foamed pressure-sensitive adhesive layer formed on one side of the polyethylene terephthalate substrate, and the thickness after drying (unfoamed pressure-sensitive adhesive layer) was prepared. The thickness of the agent layer) was applied to 35 μm, dried and cured to form an unfoamed adhesive layer, and immediately after that, from the polyethylene terephthalate substrate side, 120 ° C. × 10 seconds. Under certain conditions, heat is applied to foam The foamed pressure-sensitive adhesive layer was formed to produce a pressure-sensitive adhesive sheet having the foamed pressure-sensitive adhesive layer.

(Example 3)
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight of the trade name “Aluminum Chelate A (W)” (manufactured by Kawaken Fine Chemical Co., Ltd .; “Crosslinking agent A” in Table 1): 0 .5 parts by weight, trade name “Matsumoto Microsphere F30” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd .; “foaming agent A” in Table 1): 10 parts by weight added, containing foaming agent and metal chelate crosslinking agent The pressure-sensitive adhesive composition is prepared, and the pressure-sensitive adhesive composition is dried on one side of a polyethylene terephthalate base material (thickness: 38 μm) (the thickness of the pressure-sensitive adhesive layer in an unfoamed state). Was applied to a thickness of 40 μm, dried and cured to form an unfoamed pressure-sensitive adhesive layer, and immediately thereafter, heat was applied from the polyethylene terephthalate substrate side under the conditions of 120 ° C. × 10 seconds. Foam and stick To form a layer, to prepare a pressure-sensitive adhesive sheet having a foamed pressure-sensitive adhesive layer.

Example 4
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight of the trade name “Aluminum Chelate A (W)” (manufactured by Kawaken Fine Chemical Co., Ltd .; “Crosslinking agent A” in Table 1): 0 .5 parts by weight, terpene phenol tackifier (trade name “Sumilite Resin PR12603N” manufactured by Sumitomo Bakelite Co., Ltd.): 10 parts by weight, phosphate ester surfactant (trade name “Ply Wharf A219B”, Daiichi Kogyo Seiyaku Co., Ltd. 1 part by weight, trade name “Matsumoto Microsphere F30” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd .; “foaming agent A” in Table 1): 5 parts by weight added, foaming agent and metal chelate crosslinking A pressure-sensitive adhesive composition containing an adhesive was prepared, and the pressure-sensitive adhesive composition was dried on one side of a polyethylene terephthalate substrate (thickness: 38 μm) after drying (unfoamed). The thickness of the pressure-sensitive adhesive layer is 40 μm, dried and cured to form an unfoamed pressure-sensitive adhesive layer, and immediately after that, from the polyethylene terephthalate substrate side, 120 ° C. × Under the condition of 10 seconds, heat was applied and foamed to form a foamed pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet having a foamed pressure-sensitive adhesive layer was produced.

(Example 5)
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight of trade name “Coronate L” (manufactured by Nippon Polyurethane Industry Co., Ltd .; isocyanate-based crosslinking agent; “Crosslinking agent B” in Table 1): 5 parts by weight, trade name “Matsumoto Microsphere F30” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd .; “Foaming Agent A” in Table 1): 5 parts by weight are added to contain a foaming agent and an isocyanate-based crosslinking agent. A pressure-sensitive adhesive composition is prepared, and the pressure-sensitive adhesive composition is dried on one side of a polyethylene terephthalate substrate (thickness: 38 μm), and the thickness after drying (thickness of the unfoamed pressure-sensitive adhesive layer) is 40 μm. And then dried and cured to form an unfoamed pressure-sensitive adhesive layer, and after aging at 50 ° C. for 24 hours, from the polyethylene terephthalate substrate side, 120 ° C. × 10 seconds. In conditions, by foaming by the addition of heat to form a foamed pressure-sensitive adhesive layer, to prepare a pressure-sensitive adhesive sheet having a foamed pressure-sensitive adhesive layer.

(Comparative Example 1)
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight of the trade name “Aluminum Chelate A (W)” (manufactured by Kawaken Fine Chemical Co., Ltd .; “Crosslinking agent A” in Table 1): 3 Part by weight is added to prepare a pressure-sensitive adhesive composition containing a metal chelate crosslinking agent, and the pressure-sensitive adhesive composition is dried on one side of a polyethylene terephthalate substrate (thickness: 38 μm). It was applied to a thickness of 40 μm, dried and cured to form an adhesive layer, and an adhesive sheet having a non-foamed adhesive layer was produced.

(Comparative Example 2)
Trade name “Matsumoto Microsphere F30” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd .; “Foaming agent A” in Table 1): 5 with respect to 100 parts by weight of the acrylic polymer obtained in Preparation Example 1 of acrylic polymer By adding parts by weight, a pressure-sensitive adhesive composition containing a foaming agent was prepared, and the pressure-sensitive adhesive composition was dried on one side of a polyethylene terephthalate substrate (thickness: 38 μm) after drying ( (Unfoamed pressure-sensitive adhesive layer thickness) was applied to 40 μm and dried to form an unfoamed pressure-sensitive adhesive layer. Immediately thereafter, from the base material side made of polyethylene terephthalate, 120 ° C. × Under the condition of 10 seconds, heat was applied and foamed to form a foamed pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet having a foamed pressure-sensitive adhesive layer was produced.

(Evaluation)
About each adhesive sheet (adhesive sheet for solvent-containing material removal) obtained in Examples 1 to 5 and Comparative Examples 1 and 2, the thickness of the adhesive layer, adhesive force, solvent absorption, adhesive force after solvent absorption, The removability of the solvent-containing material and the cohesiveness of the pressure-sensitive adhesive layer were measured or evaluated by the following measurement method or evaluation method. Moreover, comprehensive evaluation was performed by these evaluations. The results are shown in Table 1.

(Method for measuring the thickness of the adhesive layer)
Using the 1/1000 dial gauge, the thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained in each example and each comparative example was measured.

(Measurement method of adhesive strength)
After the pressure-sensitive adhesive sheets obtained in each Example and each Comparative Example were allowed to stand under the conditions of 23 ° C. × 48 hours, the temperature was 23 ° C. plus or minus 2 ° C. and the relative humidity was 50% plus as a pre-measurement process. Leave in an atmosphere of minus 5% for 24 hours. The pressure-sensitive adhesive sheet cut to a size of 25 mm × 150 mm is reciprocally bonded to the following adherend by one reciprocation at a speed of 5 mm per second with the following pressure bonding apparatus. After 30 minutes have passed since the pressure bonding, the maximum stress was measured by measuring the stress when the adhesive sheet was peeled off from the adherend using a tensile tester at a tensile speed of 300 mm / min and a peeling angle of 180 °. The value (maximum value excluding the peak top in the initial measurement) was read, and the adhesive strength (N / 25 mm) was measured with the maximum value of the stress as the adhesive strength (N / 25 mm).
-Crimping device: The crimping device is an automatic type or manual type, and has a structure in which only the weight of the roller is applied to the test piece (sample) when the test piece is crimped. The roller is coated with a rubber layer having a thickness of about 6 mm and a spring hardness (Hs) of 80 plus or minus 5 [width: about 45 mm, diameter (including the rubber layer): about 95 mm, mass: 2000 plus or minus 20 g] It is.
Adherent: SUS430BA [Washed by the following cleaning method. Cleaning method: Wipe the surface of the adherend with a cloth soaked in toluene (gauze, tissue paper, exposed cloth, etc.). Wipe well until dry with a new cloth. Rinse repeatedly three or more times until it is seen to be clean. ]
Measurement environment: temperature is 23 ° C. plus or minus 2 ° C., and relative humidity is 50% plus or minus 5%.

(Measurement method of solvent absorption)
The pressure-sensitive adhesive sheet obtained in each example and each comparative example was cut into a size of 20 × 50 mm, and the weight was measured. The pressure-sensitive adhesive sheet was measured in advance using diethylene glycol monobutyl ether acetate / diethylene glycol as a screen printing solvent. Immerse it in a mixed solvent of monobutyl ether [9/1 (weight ratio)] for 1 second, immediately wipe off the solvent attached to the surface of the adhesive sheet with a waste cloth, and measure the weight again. The increase in weight (g / m ² ) was calculated. The measurement environment is 23 ° C. × 50% RH.

(Measurement method of adhesive strength after solvent absorption)
A mixed solvent of diethylene glycol monobutyl ether acetate / diethylene glycol monobutyl ether [9/1 (weight ratio)], which is a solvent for screen printing, was applied to a polyethylene terephthalate film with a wire bar at a rate of 5 g / m ^2. And the adhesive sheet obtained by cutting the adhesive sheet obtained by each comparative example into a size of 25 × 50 mm was bonded, and the adhesive layer of the adhesive sheet was allowed to absorb 5 g / m ^{2 of the} mixed solvent, The adhesive strength (N / 25 mm) was measured in the same manner as the method for measuring the adhesive strength.

(Evaluation method for removal of solvent-containing materials)
Using the fixed number of times, on the back side of the screen plate on which the paste is turned, perform the operation of uniformly sticking and removing the adhesive sheet obtained in each example and each comparative example, cleaning the screen plate, The removal property (cleanability) of the solvent-containing material was evaluated as “◯” when the paste could be removed, and “x” when the paste could not be removed due to cohesive failure.

(Method for evaluating cohesiveness of adhesive layer)
Acrylic polymer obtained in Preparation Example 1 of acrylic polymer: 100 parts by weight, phenolic tackifier (trade name “Sumilite Resin PR12603N” manufactured by Sumitomo Bakelite Co., Ltd.): 50 parts by weight, trade name “ Coronate L "(manufactured by Nippon Polyurethane Industry Co., Ltd .; isocyanate-based crosslinking agent): 2 parts by weight were added to prepare a pressure-sensitive adhesive composition containing an isocyanate-based crosslinking agent, and the pressure-sensitive adhesive composition was converted into polyethylene terephthalate. A pressure-sensitive adhesive sheet (“for cohesiveness evaluation”) having a non-foamed pressure-sensitive adhesive layer is formed on one side of a substrate made by coating so that the thickness after drying is 60 μm, dried and cured. In some cases, it is referred to as an “adhesive sheet”.

  On the non-foaming pressure-sensitive adhesive layer of the cohesiveness evaluation pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet obtained in each example and each comparative example is the surface of the non-foaming pressure-sensitive adhesive layer of the cohesiveness evaluation pressure-sensitive adhesive sheet and each example. And in the form in which the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained by each comparative example is in contact, it is pasted by a method of reciprocating twice using a 2 kg roller, the temperature is 23 ° C. plus or minus 2 ° C., and the relative humidity is After being left in an atmosphere of 50% plus or minus 5% for 30 minutes, the tensile tester was used to obtain each example and each comparative example at a tensile speed of 30 m / min and a peeling angle of 180 °. The pressure-sensitive adhesive sheet was peeled off from the pressure-sensitive adhesive sheet for cohesiveness evaluation. At this time, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained in each example and each comparative example was not broken, and each example and each Obtained by comparative example All PSA sheet which was broken by the pressure-sensitive adhesive layer as "×", was evaluated cohesiveness of the pressure-sensitive adhesive layer.

  From Table 1, the adhesive sheet for removing a solvent-containing material according to the example, the adhesive strength of the adhesive layer in a state before absorbing the solvent is an appropriate size, and the solvent absorption is excellent, Furthermore, it was confirmed that the adhesive strength after solvent absorption was high, the solvent-containing material removal performance was excellent, and the cohesive strength of the adhesive layer was high.

It is a schematic sectional drawing which shows the example of the adhesive sheet for solvent containing material removal of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Adhesive sheet for solvent-containing material removal 1b Adhesive sheet for solvent-containing material removal 2 Base material 3a Adhesive layer 3b Adhesive layer 3a1 Foamed adhesive layer 3b1 Foamed adhesive layer 3b2 Non-foamed adhesive layer

Claims (6)

A solvent-containing material-removing pressure-sensitive adhesive sheet comprising a base material and a pressure-sensitive adhesive layer formed on at least one surface of the base material, wherein the pressure-sensitive adhesive layer comprises (A) an acrylic polymer and (B) a foaming agent. And (C) at least a foamed pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing a cross-linking agent and having a structure in which the foaming agent (B) is foamed, and the surface of the foamed pressure-sensitive adhesive layer becomes a pressure-sensitive adhesive surface. A pressure-sensitive adhesive sheet for removing a solvent-containing material. The pressure-sensitive adhesive sheet for removing a solvent-containing material according to claim 1, wherein the foamed pressure-sensitive adhesive layer is formed by being subjected to a foaming treatment after being subjected to a crosslinking treatment. The pressure-sensitive adhesive sheet for removing a solvent-containing material according to claim 1 or 2, wherein the acrylic polymer (A) is an acrylic polymer having (meth) acrylic acid alkyl ester as a main monomer component. The pressure-sensitive adhesive sheet for removing a solvent-containing material according to any one of claims 1 to 3, wherein the foaming agent (B) is a thermally expandable microcapsule. The pressure-sensitive adhesive sheet for removing a solvent-containing material according to any one of claims 1 to 4, wherein the crosslinking agent (C) is a metal chelate-based crosslinking agent. The pressure-sensitive adhesive sheet for removing a solvent-containing material according to any one of claims 1 to 5, which is used as a pressure-sensitive adhesive sheet for cleaning a screen printing plate.

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