TWI879767B - Adhesives and adhesive tapes - Google Patents

Abstract

The present invention provides an adhesive in which the decrease in adhesiveness when in contact with an oil or alcohol component is suppressed, and an adhesive tape containing the adhesive. The adhesive of the present invention is an adhesive that exhibits adhesiveness by compression bonding, and comprises an acrylic polymer having an acid functional group, and a crystalline resin having a melting point of 25°C or more. In one embodiment, the above-mentioned adhesive exhibits adhesiveness by heating. In one embodiment, the above-mentioned acrylic polymer having an acid functional group contains a structural unit a derived from an alkyl (meth)acrylate having a linear or branched alkyl group with a carbon number of 4 or more.

Description

Adhesives and adhesive tapes

The present invention relates to an adhesive and an adhesive tape.

Previously, adhesive tapes or double-sided tapes were used for surface protection, insulation protection, component bonding or fixing by sticking to various components. However, when used with human hands, secretions such as sebum or hand dirt, cosmetics or hair sprays, moisturizers, sunscreens, or oils contained in food are easily attached through the fingertips. Moreover, when used in a living environment, not only oils are easily attached, but also alcohol components such as ethanol contained in perfumes or sterilization sheets, disinfectant alcohol, etc. are also easily attached. In this form of use, if components such as oils or alcohols come into contact with the adhesive layer of the adhesive sheet, there is a risk of reduced adhesion, resulting in undesirable conditions such as bulges and peeling.

[Prior Art Literature] [Patent Literature]

Patent document 1: Japanese Patent Publication No. 2009-215355

Patent document 2: Japanese Patent Publication No. 2013-100485

Patent document 3: Japanese Patent Publication No. 2017-132911

This invention is made to solve the previous problems, and its purpose is to provide an adhesive tape that suppresses the decrease of adhesive force when it comes into contact with oil or alcohol components.

The adhesive of the present invention exhibits adhesiveness by compression bonding and comprises an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25°C or above.

In one embodiment, the adhesive exhibits adhesion by heating.

In one embodiment, the acrylic polymer having an acid functional group contains a structural unit a derived from an alkyl (meth)acrylate having a linear or branched alkyl group with 4 or more carbon atoms.

In one embodiment, the content ratio of the structural unit a is 50 parts by weight or more relative to 100 parts by weight of the acrylic polymer having an acid functional group.

In one embodiment, the crystalline resin is a polyolefin resin.

In one embodiment, the polyolefin resin is a maleic anhydride-modified polyolefin resin, a maleic acid-modified polyolefin resin, or an acrylic acid-modified polyolefin resin.

In one embodiment, the adhesive comprises C5 petroleum resin and/or C9 petroleum resin.

According to another aspect of the present invention, an adhesive tape is provided. The adhesive tape contains the above-mentioned adhesive.

In one embodiment, the adhesive tape has a substrate and an adhesive layer disposed on at least one side of the substrate, and the adhesive layer contains the adhesive.

In one embodiment, the substrate is formed by at least one selected from polyacrylate, polyurethane, polyimide, polyarylamide, polyamide, ethylene-vinyl alcohol copolymer, polyetherimide, polyvinylidene fluoride, polyester, polypropylene, polyethylene, and polyphenylene sulfide.

In one embodiment, the adhesive tape is provided with a peeling film on the side of the adhesive layer opposite to the substrate.

According to the present invention, an adhesive whose adhesive force is suppressed from decreasing when in contact with oil or alcohol components, and an adhesive tape containing the adhesive can be provided. In addition, the adhesive of the present invention exhibits excellent adhesion to both metallic adherends and non-metallic adherends. Furthermore, the adhesive of the present invention has excellent heat resistance and chemical resistance, and can exhibit excellent adhesion and bonding properties in various applications.

10: Base material

20: Adhesive layer

100: Adhesive tape

Figure 1 is a schematic cross-sectional view of an adhesive tape according to one embodiment of the present invention.

A. Adhesive

The adhesive of the present invention is an adhesive that exhibits adhesion by compression bonding, and comprises an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25°C or above. In the present invention, by using an acrylic polymer having an acid functional group and the above-mentioned crystalline resin in combination, an adhesive having excellent heat resistance and chemical resistance and suppressing the decrease in adhesion when in contact with oil or alcohol components can be obtained. In addition, if the adhesive of the present invention is used in a double-sided adhesive tape, it can be preferably used for bonding metal materials to metal materials, bonding non-metal materials to non-metal materials, and bonding metal materials to non-metal materials.

The above adhesive may be an adhesive that exhibits adhesion at room temperature (25°C), or an adhesive that exhibits adhesion by heating (e.g., 100°C to 200°C). An adhesive that exhibits adhesion by heating may exhibit adhesion when cooled to room temperature after heating.

A-1. Acrylic polymers with acid functional groups

Examples of acrylic polymers having acid functional groups include acrylic polymers containing one or more structural units derived from (meth) alkyl acrylates and structural units derived from monomers having acid functional groups.

In the above adhesive, the content ratio of the acrylic polymer with acid functional groups is preferably 7 to 95 parts by weight, more preferably 15 to 90 parts by weight, further preferably 20 to 85 parts by weight, and particularly preferably 40 to 85 parts by weight relative to 100 parts by weight of the solid content in the adhesive. The content of the acrylic polymer with acid functional groups can be set to an appropriate amount according to the required adhesion, etc. Furthermore, the above adhesive may contain acrylic polymers without acid functional groups in addition to acrylic polymers with acid functional groups, or may not contain acrylic polymers without acid functional groups.

The content ratio of the structural unit derived from the (meth) alkyl acrylate is preferably 50 to 99 parts by weight, more preferably 70 to 98 parts by weight, and further preferably 80 to 98 parts by weight relative to 100 parts by weight of the acrylic polymer having an acid functional group.

It is preferred that the above-mentioned (meth)acrylic acid alkyl ester has a linear or branched alkyl group with a carbon number of 1 to 24 (more preferably 3 to 20, further preferably 4 to 12, and particularly preferably 4 to 8).

Examples of the above-mentioned (meth)acrylic acid alkyl esters include: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, eicosyl (meth)acrylate, etc.

In one embodiment, the acrylic polymer having an acid functional group contains a structural unit a derived from a (meth)acrylic acid alkyl ester having a linear or branched alkyl group with 4 or more carbon atoms (preferably 4 to 12, more preferably 4 to 8), and the content ratio of the structural unit a is 50 parts by weight or more (preferably 50 to 99 parts by weight, more preferably 70 to 98 parts by weight, and further preferably 80 to 98 parts by weight) relative to 100 parts by weight of the acrylic polymer having an acid functional group. If an acrylic polymer having an acid functional group and containing a specific amount of the structural unit a or more is used, an adhesive having excellent heat resistance and chemical resistance and whose adhesiveness reduction when in contact with oil or alcohol components is suppressed can be obtained.

In one embodiment, an alkyl (meth)acrylate having a branched alkyl group is used as the above-mentioned alkyl (meth)acrylate. If an alkyl (meth)acrylate having a branched alkyl group is used, an adhesive tape having excellent chemical resistance can be obtained. The carbon number of the above-mentioned branched alkyl group is preferably 4 or more, more preferably 4 to 12, and further preferably 4 to 8. An alkyl (meth)acrylate having a straight alkyl group and an alkyl (meth)acrylate having a branched alkyl group can also be used together. In addition, as the alkyl (meth)acrylate, an alkyl (meth)acrylate having a branched alkyl group can also be used alone.

In one embodiment, in the above-mentioned acrylic polymer having an acid functional group, the content ratio of the structural unit derived from the (meth)acrylic acid alkyl ester having a branched alkyl group relative to 100 parts by weight of the structural unit derived from the (meth)acrylic acid alkyl ester (i.e., the total amount of the (meth)acrylic acid alkyl ester having a linear alkyl group and the (meth)acrylic acid alkyl ester having a branched alkyl group is 100 parts by weight), preferably 50 parts by weight to 100 parts by weight, more preferably 70 parts by weight to 100 parts by weight, and further preferably 80 parts by weight to 100 parts by weight.

Examples of (meth)acrylic acid alkyl esters having a branched alkyl group include isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, and 2-methylbutyl (meth)acrylate. Among them, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, or isodecyl (meth)acrylate are preferred, and 2-ethylhexyl (meth)acrylate is more preferred. If 2-ethylhexyl (meth)acrylate is used, an adhesive having reduced adhesion when in contact with oil or alcohol components can be obtained.

Examples of acid functional groups possessed by acrylic polymers having acid functional groups include carboxyl groups, acid anhydride groups, phosphoric acid groups, and sulfonic acid groups. Therefore, examples of monomers having the above acid functional groups include carboxyl group-containing monomers, acid anhydride group-containing monomers, phosphoric acid group-containing monomers, and sulfonic acid group-containing monomers. Among them, carboxyl group-containing monomers are preferred. If carboxyl group-containing monomers are used, they have the following characteristics: they are easy to show adhesion to metal plates, and they are also easy to copolymerize with other acrylic monomers in terms of design and production. In addition, the polymer formed by copolymerization is easy to crosslink.

Examples of the above-mentioned carboxyl-containing monomers include: (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, succinic acid, fumaric acid, crotonic acid, etc. Among them, acrylic acid is preferred.

The content ratio of the structural unit derived from the monomer having an acid functional group is preferably 1.5 to 20 parts by weight, more preferably 1.8 to 15 parts by weight, and further preferably 2 to 10 parts by weight relative to 100 parts by weight of the acrylic polymer having an acid functional group.

、乙烯基吡

、乙烯基吡咯、乙烯基咪唑、乙烯基

唑、乙烯基

啉、N-乙烯基羧醯胺類、苯乙烯、α-甲基苯乙烯、N-乙烯基己內醯胺等乙烯系單體；丙烯腈、甲基丙烯腈等氰基丙烯酸酯單體；(甲基)丙烯酸縮水甘油酯等含有環氧基之丙烯酸系單體；聚乙二醇(甲基)丙烯酸酯、聚丙二醇(甲基)丙烯酸酯、甲氧基乙二醇(甲基)丙烯酸酯、甲氧基聚丙二醇(甲基)丙烯酸酯等二醇系丙烯酸酯單體；(甲基)丙烯酸四氫糠酯、氟(甲基)丙烯酸酯、聚矽氧(甲基)丙烯酸酯等具有雜環、鹵素原子、矽原子等之丙烯酸酯系單體；己二醇二(甲基)丙烯酸酯、(聚)乙二醇二(甲基)丙烯酸酯、(聚)丙二醇二(甲基)丙烯酸酯、新戊二醇二(甲基)丙烯酸酯、季戊四醇二(甲基)丙烯酸 酯、三羥甲基丙烷三(甲基)丙烯酸酯、季戊四醇三(甲基)丙烯酸酯、二季戊四醇六(甲基)丙烯酸酯、環氧丙烯酸酯、聚酯丙烯酸酯、丙烯酸胺基甲酸酯等多官能單體；異戊二烯、丁二烯、異丁烯等烯烴系單體；乙烯醚等乙烯醚系單體等。該等單體成分可單獨使用或組合2種以上使用。 The acrylic polymer having an acid functional group may also contain structural units derived from other monomers copolymerizable with the above-mentioned alkyl (meth)acrylate and/or monomer having an acid functional group, as required, for the purpose of improving cohesion, heat resistance, crosslinking, etc. Examples of such other monomers include: hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, methacrylic acid (4-hydroxyethyl) ester, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, methacrylic acid (4-hydroxyethyl) ester, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyethyl (meth)acrylate ... hydroxyl-containing monomers such as (methyl)acrylamide, N,N-dimethyl (methyl)acrylamide, N-butyl (methyl)acrylamide, N-hydroxymethyl (methyl)acrylamide, N-hydroxymethylpropane (methyl)acrylamide, and the like (N-substituted)amide monomers; (methyl)acrylamide alkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; (methyl)acrylamide alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; N-cyclohexyl cis-butylenediamide, N-isopropyl cis-butylenediamide, N-lauryl cis-butylenediamide, N-phenyl cis-1-butene diimide monomers; N-methyliconimide, N-ethyliconimide, N-butyliconimide, N-octyliconimide, N-2-ethylhexyliconimide, N-cyclohexyliconimide, N-lauryliconimide and other iconimide monomers; N-(meth)acryloyloxymethylene Succinimide monomers such as succinimide, N-(meth)acryl-6-oxyhexamethylenesuccinimide, and N-(meth)acryl-8-oxyoctamethylenesuccinimide; vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperidone,

, vinyl pyridine

, vinylpyrrole, vinylimidazole, vinyl

Azole, vinyl

Vinyl monomers such as phenoxyethylene, N-vinyl carboxylic acid amides, styrene, α-methylstyrene, and N-vinyl caprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; acrylic monomers containing epoxy groups such as glycidyl (meth)acrylate; glycol acrylate monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; heterocyclic, halogenated monomers such as tetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, and polysiloxane (meth)acrylate. atom, silicon atom, etc.; polyfunctional monomers such as 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, trihydroxymethylpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate; olefin monomers such as isoprene, butadiene, isobutylene; vinyl ether monomers such as vinyl ether, etc. These monomer components can be used alone or in combination of two or more.

The content ratio of the structural units derived from the above other monomers is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, and further preferably 5 parts by weight or less relative to 100 parts by weight of the acrylic polymer having an acid functional group.

The weight average molecular weight of the acrylic polymer having acid functional groups is preferably 300,000 to 2,000,000, and more preferably 500,000 to 1,500,000. The weight average molecular weight can be measured by GPC (Gel Permeation Chromatography) (solvent: THF (Tetrahydrofuran)).

A-2. Crystalline resin

As mentioned above, the adhesive of the present invention includes a crystalline resin. The so-called crystalline resin refers to a resin having a clear endothermic peak (half-value width within 15°C) in the differential calorimetry curve measured by a differential scanning calorimeter (DSC).

In the adhesive, the content ratio of the crystalline resin relative to 100 parts by weight of the solid content in the adhesive is preferably 3 parts by weight to 90 parts by weight, more preferably 10 parts by weight to 85 parts by weight, and further preferably 15 parts by weight to 80 parts by weight.

The melting point of the above-mentioned crystalline resin is above 25°C, more preferably above 40°C, further preferably 60°C~120°C, and particularly preferably 60°C~100°C. If it is within this range, a less sticky adhesive can be obtained. The melting point can be measured by differential scanning calorimetry (DSC).

The weight average molecular weight of the above-mentioned crystalline resin is preferably 50,000 to 1.5 million, and more preferably 70,000 to 1 million.

The crystallinity of the above-mentioned crystalline resin is preferably 10% or more, and more preferably 20% or more. The crystallinity can be measured by differential scanning calorimetry (DSC).

In one embodiment, the crystalline resin is a polyolefin resin. Examples of the polyolefin resin include ethylene homopolymers, ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, ethylene-1-heptene copolymers, ethylene-1-octene copolymers, ethylene-1-nonene copolymers, ethylene-1-decene copolymers, ethylene-1-undecene copolymers, ethylene-1-dodecene copolymers, ethylene-1-tridecene copolymers, ethylene-1-tetradecene copolymers, ethylene-1-pentadecene copolymers, ethylene-1 -Hexadecene copolymer, ethylene-1-heptadecene copolymer, ethylene-1-octadecene copolymer, ethylene-1-nonadecene copolymer, ethylene-1-eicosene copolymer and other ethylene-α-olefin copolymers; ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer and other ethylene-vinyl ester copolymers; ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer and other ethylene-unsaturated carboxylic acid alkyl ester copolymers; acrylic resins, etc.

In one embodiment, a crystalline polypropylene resin is used as the crystalline resin. The crystalline polypropylene resin may be a homopolymer or a copolymer obtained by copolymerizing propylene and a monomer copolymerizable with propylene. Examples of monomers copolymerizable with propylene include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, 3-methyl-1-pentene and other α-olefins. In the crystalline polypropylene resin, the content of structural units derived from propylene is preferably 60 mol% to 99 mol%, more preferably 65 mol% to 99 mol%, and further preferably 70 mol% to 99 mol%. In crystalline polypropylene resins, the content of structural units derived from α-olefins is preferably 1 mol% to 15 mol%, and more preferably 1 mol% to 10 mol%.

In one embodiment, a modified polyolefin resin is used as the crystalline resin. If a modified polyolefin resin is used, the phase separation between the crystalline resin and the acrylic polymer having an acid functional group is suppressed, the oozing out is less, and an adhesive having an adhesive layer with excellent transparency can be obtained. As the modified polyolefin resin, preferably, maleic anhydride-modified polyolefin resin, maleic acid-modified polyolefin resin, acrylic acid-modified polyolefin resin, etc. can be used. Specifically, the resins obtained by modifying the above-mentioned polyolefin resins with maleic anhydride, maleic acid or acrylic acid can be listed. Among them, maleic anhydride polyolefin resins are preferred, and maleic anhydride-modified propylene resins are more preferred. As a specific example of maleic anhydride-modified propylene resins, the resin obtained by modifying the above-mentioned crystalline polypropylene resins with maleic anhydride can be listed. The modification rate of the modified polyolefin resin is preferably 1% to 5% by weight, and more preferably 1.5% to 2% by weight.

A-3. Additives

The above-mentioned adhesive may contain any appropriate additives as needed. Examples of such additives include: crosslinking agents, adhesive agents, plasticizers (e.g., trimellitic acid ester plasticizers, pyromellitic acid ester plasticizers), pigments, dyes, fillers, anti-aging agents, conductive materials, ultraviolet absorbers, light stabilizers, stripping modifiers, softeners, surfactants, flame retardants, antioxidants, solvents, etc. In addition, the above-mentioned adhesive may also contain any appropriate solvents.

Any appropriate adhesive imparting agent can be used as the adhesive imparting agent. For example, an adhesive imparting resin can be used as the adhesive imparting agent. Specific examples of the adhesive-imparting resin include: rosin-based adhesive-imparting resins (e.g., unmodified rosin, modified rosin, rosin phenol-based resins, rosin ester-based resins, etc.), terpene-based adhesive-imparting resins (e.g., terpene-based resins, terpene phenol-based resins, styrene-modified terpene-based resins, aromatic-modified terpene-based resins, hydrogenated terpene-based resins), hydrocarbon-based adhesive-imparting resins (e.g., aliphatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aromatic hydrocarbon resins ( For example, styrene-based resins, xylene-based resins, etc.), aliphatic-aromatic petroleum resins, aliphatic-aliphatic cyclopentane-based petroleum resins, hydrogenated hydrocarbon resins, lavender-based resins, lavender-indene-based resins, etc.), phenol-based adhesive resins (for example, alkylphenol-based resins, xylene formaldehyde-based resins, soluble phenolic resins, phenolic varnishes, etc.), ketone-based adhesive resins, polyamide-based adhesive resins, epoxy-based adhesive resins, elastic system adhesive resins, etc.

In one embodiment, the adhesive uses C5 petroleum resin and/or C9 petroleum resin as an adhesive agent. If such adhesive agents are used, good adhesion to non-polar adherends such as polypropylene can be imparted.

The softening point of the above-mentioned adhesive agent is preferably 70℃~200℃, and more preferably 80℃~190℃. If it is within this range, an adhesive layer with appropriately adjusted storage elastic modulus and loss elastic modulus can be obtained.

The content ratio of the above-mentioned adhesive agent relative to the total weight of 100 parts by weight of the acrylic polymer having an acid functional group and the crystalline resin having a melting point of 25°C or above is preferably 5 parts by weight to 50 parts by weight, and more preferably 10 parts by weight to 40 parts by weight.

唑啉系交聯劑、氮丙啶系交聯劑、胺系交聯劑等。其中，較佳為異氰酸酯系交聯劑、環氧系交聯劑或金屬螯合物系交聯劑。 Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, and peroxide crosslinking agents. Examples of the crosslinking agent include urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents,

Oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, etc. Among them, isocyanate crosslinking agents, epoxy crosslinking agents or metal chelate crosslinking agents are preferred.

Specific examples of the above-mentioned isocyanate crosslinking agent include: low-order aliphatic polyisocyanates such as butyl diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentyl diisocyanate, cyclohexyl diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylyl diisocyanate; trihydroxymethylpropane/toluene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"), trihydroxymethylpropane/hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL”), isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry, trade name “Coronate HX”) and other isocyanate adducts. The content of isocyanate crosslinking agent can be set to any appropriate amount according to the required adhesion and elastic modulus. Relative to 100 parts by weight of the total amount of acrylic polymer with acid functional group and crystalline resin with melting point above 25°C, it is typically 0.1 parts by weight to 20 parts by weight, and preferably 0.5 parts by weight to 10 parts by weight.

Examples of the epoxy crosslinking agent include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-glycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 1600"), neopentyl glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 1500NP"), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 40E"), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 70P"), polyethylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name "Epiol E-400"), polypropylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name "Epiol P-200"), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, trade name "DENACOL EX-611"), glycerol polyglycidyl ether (manufactured by Nagase ChemteX, trade name "DENACOL EX-314"), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX, trade name "DENACOL EX-512”), sorbitan polyglycidyl ether, trihydroxymethylpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, tri(2-hydroxyethyl)isocyanuric acid triglycidyl ester, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, epoxy resins having more than 2 epoxy groups in the molecule, etc. The content of the epoxy crosslinking agent can be set to any appropriate amount according to the required adhesion and elastic modulus, and is typically 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, relative to 100 parts by weight of the total amount of the acrylic polymer having an acid functional group and the crystalline resin having a melting point of more than 25°C.

As metal chelate crosslinking agents, metal chelate compounds whose metal atoms are aluminum, zirconium, titanium, zinc, iron, tin, etc. can be used. Among them, aluminum chelate compounds or titanium chelate compounds are preferred.

Examples of the aluminum chelate compound include diisopropoxyaluminum monoacetate oleyl acetate, monoisopropoxyaluminum diacetate oleyl acetate, monoisopropoxyaluminum monooleate ethyl acetate, diisopropoxyaluminum monoacetate lauryl acetate, diisopropoxyaluminum monoacetate stearyl acetate, diisopropoxyaluminum monoacetate isostearyl acetate, monoisopropoxyaluminum mono-N-lauryl-β-aluminum hydroxide (a lanate) monoacetylacetate lauryl, tri(acetylacetone)aluminum, acetylacetone aluminum bis(acetylacetic acid ethyl ester), monoacetylacetone aluminum bis(acetylacetic acid isobutyl ester) chelate, monoacetylacetone aluminum bis(acetylacetic acid 2-ethylhexyl ester) chelate, monoacetylacetone aluminum bis(acetylacetic acid dodecyl ester) chelate, monoacetylacetone aluminum bis(acetylacetic acid oleyl ester) chelate, etc.

Examples of titanium chelate compounds include: titanium diisopropoxybis(acetylacetonate), titanium tetra-n-butyrate, titanium tetra(2-ethylhexanoate), titanium tetraacetylacetonate, titanium diisopropoxybis(ethylacetylacetonate), titanium octanediol, etc.

As other metal chelate compounds, there are: zirconium tetraacetylpyruvate, zirconium tributoxymonoacetylpyruvate, etc.

The above-mentioned metal chelate crosslinking agents may be used alone or in combination of two or more.

The content of the metal chelate crosslinking agent can be set to any appropriate amount according to the required adhesion and elastic modulus. Relative to 100 parts by weight of the total amount of the acrylic polymer with acid functional groups and the crystalline resin with a melting point of 25°C or above, it is typically 0.01 to 10 parts by weight, preferably 0.03 to 7 parts by weight, and further preferably 0.05 to 5 parts by weight.

B. Adhesive tape

FIG1 is a schematic cross-sectional view of an adhesive tape of one embodiment of the present invention. The adhesive tape 100 has a substrate 10 and an adhesive layer 20 disposed on at least one side (two sides in the example shown) of the substrate 10. The adhesive layer 20 includes the adhesive described in the above-mentioned item A. Although not shown, the above-mentioned adhesive tape may also be provided with a peeling film on the outer side of the adhesive layer (i.e., the surface of the adhesive layer opposite to the substrate) in order to protect the adhesive surface before use.

The above-mentioned adhesive tape may be an adhesive tape that exhibits adhesion at room temperature (25°C), or an adhesive tape that exhibits adhesion by heating. The adhesive tape that exhibits adhesion by heating may exhibit adhesion after being cooled to room temperature after being heated.

When the adhesive layer of the adhesive tape of the present invention is attached to an aluminum plate, the adhesive force at 25°C is preferably 0.5N/10mm or more, more preferably 0.8N/10mm-20N/10mm, and further preferably 1N/10mm-10N/10mm. In this specification, the so-called adhesive force refers to the adhesive force measured by the method according to JIS Z 0237:2000, which is measured by attaching the adhesive tape to the adherend by one back and forth movement of a 2kg roller, leaving it at 25°C for 30 minutes, and then peeling the adhesive tape at a peeling angle of 180° and a peeling speed (tensile speed) of 300mm/min. Furthermore, in the case of an adhesive tape that exhibits adhesiveness by heating, the adhesive tape and the adherend are bonded by bonding at a temperature at which the adhesive tape exhibits adhesiveness (e.g., 130°C, 0.4MPa, 5 minutes), and the adhesive force measured after cooling to 25°C is equivalent to the above-mentioned adhesive force.

When the adhesive layer of the adhesive tape of the present invention is attached to an aluminum plate, the adhesive force at 25°C is preferably 0.3N/10mm or more, more preferably 0.5N/10mm~20N/10mm, and further preferably 1N/10mm~10N/10mm.

The thickness of the adhesive tape is preferably 5μm~200μm, more preferably 15μm~150μm, and further preferably 30μm~100μm.

B-1. Adhesive layer

The above adhesive layer includes the adhesive described in item A above.

The thickness of the adhesive layer is preferably 1μm~100μm, more preferably 3μm~80μm, and further preferably 5μm~50μm.

The probe viscosity value of the above adhesive layer at 25°C is preferably less than 500g, more preferably less than 400g, further preferably less than 340g, and particularly preferably 10g to 300g. The method for measuring the probe viscosity value is described below.

B-2. Base material

As the above-mentioned substrate, a resin film can be preferably used. Examples of the resin constituting the resin film include: polyacrylate, polyurethane, polyimide, polyarylamide, polyamide, ethylene-vinyl alcohol copolymer, polyetherimide, polyvinylidene fluoride, polyester, polypropylene, polyethylene, polyphenylene sulfide, etc. These resins can be used alone or in combination of two or more.

The thickness of the substrate is preferably 1μm~100μm, more preferably 5μm~70μm, and further preferably 15μm~50μm.

[Implementation example]

The present invention is specifically described below by way of examples, but the present invention is not limited to these examples. In addition, in the examples, "parts" and "%" are based on weight unless otherwise specified.

<<Single-sided adhesive tape>>

[Implementation Example 1]

Add 2-ethylhexyl acrylate/acrylic acid (95 parts by weight/5 parts by weight), 0.2 parts by weight of benzoyl peroxide as an initiator, and 120 parts by weight of ethyl acetate to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser. Introduce nitrogen while slowly stirring. Keep the liquid temperature in the flask at around 60°C. Perform a polymerization reaction for about 6 hours to obtain an acrylic copolymer (1) with a weight average molecular weight of 1.3 million.

25 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight 75,000, melting point 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 75 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (1) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying was 10 μm, thereby obtaining an adhesive tape (1).

[Example 2]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

25 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight 75,000, melting point 70°C) as a modified olefin resin, 30 parts by weight of a hydrogenated derivative of a C9 petroleum resin (Arakawa Chemical Industries, Ltd., trade name "Arkon P-125", hydrogenation rate: 95%, softening point: 125°C), and 2 parts by weight of an isocyanate crosslinking agent (Tosoh Corporation, trade name "Coronate L") were added to 75 parts by weight of an acrylic copolymer (1), and the mixture was diluted with toluene to prepare an adhesive (2) having a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30μm) in such a way that the thickness of the adhesive layer after drying was 10μm, to obtain an adhesive tape (2).

[Implementation Example 3]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

25 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight: 75,000, melting point: 90°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 75 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (3) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 12μm) in such a way that the thickness of the adhesive layer after drying was 20μm, to obtain an adhesive tape (3).

[Implementation Example 4]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

15 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight: 75,000, melting point: 90°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 85 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (4) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 12μm) in such a way that the thickness of the adhesive layer after drying was 5μm, to obtain an adhesive tape (4).

[Implementation Example 5]

A polyester film with a thickness of 50 μm (manufactured by TORAY, trade name "Lumirror") was used as the substrate, and the thickness of the adhesive layer was set to 20 μm. Otherwise, the adhesive tape (5) was prepared in the same manner as in Example 4.

[Implementation Example 6]

Add 2-ethylhexyl acrylate/acrylic acid (90 parts by weight/10 parts by weight), 0.2 parts by weight of benzoyl peroxide as an initiator, and 120 parts by weight of ethyl acetate to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser. Introduce nitrogen while slowly stirring. Keep the liquid temperature in the flask at around 60°C. Perform a polymerization reaction for about 6 hours to obtain an acrylic copolymer (2) with a weight average molecular weight of 1.2 million.

15 parts by weight of propylene-butene copolymer modified with maleic anhydride (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point: 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 85 parts by weight of acrylic copolymer (2) as a modified olefin resin, and diluted with toluene to prepare an adhesive (5) having a solid content of 15%.

The obtained adhesive was applied onto a substrate (polyimide film, manufactured by TORAY, trade name "Kapton 100H", thickness: 25 μm) in such a way that the thickness of the adhesive layer after drying was 10 μm, thereby obtaining an adhesive tape (6).

[Implementation Example 7]

A polyester film with a thickness of 50 μm (manufactured by TORAY, trade name "Lumirror") was used as the substrate, and the thickness of the adhesive layer was set to 50 μm. Otherwise, the adhesive tape (7) was prepared in the same manner as in Example 6.

[Implementation Example 8]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

25 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-Lz", weight average molecular weight: 100,000, melting point: 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 75 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (6) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying became 10 μm, thereby obtaining an adhesive tape (8).

[Implementation Example 9]

Add 2-ethylhexyl acrylate/acrylic acid (100 parts by weight/2 parts by weight), 0.2 parts by weight of benzoyl peroxide as an initiator, and 230 parts by weight of ethyl acetate to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser. Introduce nitrogen while slowly stirring. Keep the liquid temperature in the flask at around 60°C. Perform a polymerization reaction for about 6 hours to obtain an acrylic copolymer (3) with a weight average molecular weight of 650,000.

30 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point: 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 70 parts by weight of acrylic copolymer (3), and diluted with toluene to prepare an adhesive (7) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying became 10 μm, thereby obtaining an adhesive tape (9).

[Example 10]

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, add n-butyl acrylate/ethyl acrylate/acrylic acid (70 parts by weight/25 parts by weight/5 parts by weight), 0.2 parts by weight of benzoyl peroxide as an initiator, and 120 parts by weight of ethyl acetate. While slowly stirring, introduce nitrogen. Keep the liquid temperature in the flask at around 60°C and carry out a polymerization reaction for about 6 hours to obtain an acrylic copolymer (4) with a weight average molecular weight of 700,000.

15 parts by weight of propylene-butene copolymer modified with maleic anhydride (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point: 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 85 parts by weight of acrylic copolymer (4), and diluted with toluene to prepare an adhesive (8) having a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying became 10 μm, thereby obtaining an adhesive tape (10).

[Implementation Example 11]

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, add n-butyl acrylate/acrylic acid (95 parts by weight/5 parts by weight), 0.2 parts by weight of 2,2'-azobisisobutyronitrile as an initiator, and 233 parts by weight of ethyl acetate. While slowly stirring, introduce nitrogen. Keep the liquid temperature in the flask at around 60°C and carry out a polymerization reaction for about 6 hours to obtain an acrylic copolymer (5) with a weight average molecular weight of 700,000.

15 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point: 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 85 parts by weight of acrylic copolymer (5), and diluted with toluene to prepare an adhesive (9) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying was 15 μm, thereby obtaining an adhesive tape (11).

[Implementation Example 12]

Acrylic copolymer (2) was obtained in the same manner as in Example 6.

75 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 25 parts by weight of acrylic copolymer (2), and diluted with toluene to prepare an adhesive (10) with a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 12μm) in such a way that the thickness of the adhesive layer after drying became 3μm, thereby obtaining an adhesive tape (12).

[Implementation Example 13]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

75 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 25 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (11) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polyester film, manufactured by TORAY, trade name "Lumirror", thickness: 50 μm) in such a way that the thickness of the adhesive layer after drying was 25 μm, thereby obtaining an adhesive tape (13).

[Example 14]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

85 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight: 75,000, melting point: 90°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 15 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (12) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying became 10 μm, thereby obtaining an adhesive tape (14).

[Implementation Example 15]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

15 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight 75,000, melting point 70°C) and 0.5 parts by weight of aluminum chelate crosslinking agent (trade name "ALUMI-CHELATE A", manufactured by Kawaken Fine Chemicals Co., Ltd.) were added to 85 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (13) having a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying was 20 μm, thereby obtaining an adhesive tape (15).

[Implementation Example 16]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

85 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight 75,000, melting point 70°C) and 0.2 parts by weight of aluminum chelate crosslinking agent (trade name "ALUMI-CHELATE A", manufactured by Kawaken Fine Chemicals Co., Ltd.) were added to 15 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (14) having a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying was 5 μm, thereby obtaining an adhesive tape (16).

[Implementation Example 17]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

75 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight 75,000, melting point 90°C) and 0.1 parts by weight of epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrad C") were added to 25 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (15) with a solid content of 15%.

The obtained adhesive was applied onto a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying became 5 μm, thereby obtaining an adhesive tape (17).

[Comparison Example 1]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

To 100 parts by weight of the acrylic copolymer (1), 18 parts by weight of a modified rosin resin (manufactured by Harima Chemicals, trade name "Hariester KT-3") and 2 parts by weight of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "Coronate L") were added, and diluted with toluene to prepare an adhesive (C1) with a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30μm) in such a way that the thickness of the adhesive layer after drying was 10μm, and an adhesive tape (C1) was obtained.

[Comparison Example 2]

Acrylic copolymer (1) was obtained in the same manner as in Example 1.

0.5 parts by weight of epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrad C") was added to 100 parts by weight of acrylic copolymer (1), and diluted with toluene to prepare an adhesive (C2) with a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30μm) in such a way that the thickness of the adhesive layer after drying was 10μm, and an adhesive tape (C2) was obtained.

[Comparison Example 3]

Acrylic copolymer (5) was obtained in the same manner as in Example 11.

To 100 parts by weight of the acrylic copolymer (5), 30 parts by weight of a terpene phenol resin (manufactured by Yasuhara Chemical Co., Ltd., trade name "YS Polystar S-145", softening point: about 145°C), 2 parts by weight of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "Coronate L"), and 0.03 parts by weight of an epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrad C") were added, and diluted with toluene to prepare an adhesive (C3) having a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30μm) in such a way that the thickness of the adhesive layer after drying was 10μm, and an adhesive tape (C3) was obtained.

[Comparison Example 4]

Add 2-ethylhexyl acrylate/2-hydroxyethyl acrylate (100 parts by weight/4 parts by weight), 0.2 parts by weight of 2,2'-azobisisobutyronitrile as an initiator, and 233 parts by weight of ethyl acetate to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser. Introduce nitrogen while slowly stirring. Keep the liquid temperature in the flask at around 60°C. Perform a polymerization reaction for about 6 hours to obtain an acrylic copolymer (6) with a weight average molecular weight of 550,000.

15 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 85 parts by weight of acrylic copolymer (6) as a modified olefin resin, and diluted with toluene to prepare an adhesive (C4) with a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness 30μm) in such a way that the thickness of the adhesive layer after drying became 10μm, and an adhesive tape (C4) was obtained.

[Comparison Example 5]

Acrylic copolymer (6) was obtained in the same manner as in Comparative Example 4.

75 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 7.5, melting point 70°C) and 2 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Co., Ltd., trade name "Coronate L") were added to 25 parts by weight of acrylic copolymer (6), and diluted with toluene to prepare an adhesive (C5) with a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness 30μm) in such a way that the thickness of the adhesive layer after drying became 10μm, and an adhesive tape (C5) was obtained.

[Comparison Example 6]

100 parts by weight of maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyobo Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 75,000, melting point: 70°C) as a modified olefin resin was dissolved in toluene to prepare an adhesive (C6) with a solid content of 15%.

The obtained adhesive was applied to a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30μm) in such a way that the thickness of the adhesive layer after drying became 10μm, and an adhesive tape (C6) was obtained.

<Evaluation>

The obtained single-sided adhesive tape was subjected to the following evaluation. The results are shown in Table 1 and Table 2.

(1) Adhesion (to aluminum plate)

The adhesive tapes obtained in the examples and comparative examples were attached to the surface of the aluminum plate under the following conditions to obtain the test body. Furthermore, the adhesive tapes of Example 12, Example 13, Example 14, Example 16, Example 17, Comparative Example 5 and Comparative Example 6 are heat-bonding adhesive tapes, so they are only pressed at heating (130°C), and the other adhesive tapes are pressed at room temperature (25°C) and heating (130°C).

For the obtained test piece, a precision universal testing machine (trade name "Autograph AG-I", manufactured by Shimadzu Corporation) was used to measure the force (N/10mm) required to peel the adhesive tape from the aluminum plate surface under the following conditions, which was taken as the adhesive force of the adhesive tape.

(Compression fitting conditions)

Normal temperature crimping: crimp with a 2kg roller, back and forth once.

Heating and pressing: Pressing is performed at 0.4MPa for 5 minutes at a setting of 130℃ on the surface temperature of the bonding device.

(Separation conditions)

Temperature: Normal temperature (25℃)

Peeling speed: 300mm/min

Peeling angle: 180°

(2) Adhesion (to polypropylene board)

The adhesive force of the adhesive tape was measured in the same manner as in the above evaluation (1), except that the aluminum plate was replaced with a polypropylene plate.

(3) Oil resistance

Obtain the test subjects in the same manner as (1) and (2) above.

The obtained test piece was immersed in oleic acid at 60°C for 72 hours, and the presence or absence of bulging and peeling of the adhesive tape was visually confirmed. Furthermore, for the test piece whose adhesive tape was not peeled off, the oleic acid was wiped off and then left to stand for 30 minutes in an environment of 23°C and 50% RH. Thereafter, the adhesive force of the adhesive tape (adhesion after immersion in oleic acid) was measured by the same method as (1) above. In addition, oleic acid was used as a simulated sebum.

(4) Alcohol resistance

Obtain the test subjects in the same manner as (1) and (2) above.

The obtained test body was immersed in 60°C ethanol diluted with distilled water to 75% by weight for 72 hours, and the presence or absence of bulging and peeling of the adhesive tape was visually confirmed. Furthermore, for the test body whose adhesive tape was not peeled off, after wiping off the oleic acid, it was left to stand for 30 minutes in an environment of 23°C and 50% RH. Thereafter, the adhesion of the adhesive tape (adhesion after ethanol immersion) was measured by the same method as above (1). In addition, ethanol was used as the alcohol for simulating disinfection.

(5) Fog value

Using a mist meter (model: HM-150, manufactured by Murakami Color Laboratory), incident light is irradiated from the adhesive layer side to measure the mist value of the adhesive tape.

(6) Holding force test

The adhesive tapes obtained in the examples and comparative examples were attached to SUS304BA plates under the following conditions to obtain test bodies (pressed area: 10 mm × 20 mm). Furthermore, the adhesive tapes of Examples 12, 13, 14, 16, 17, Comparative Examples 5 and 6 were heat-bonded adhesive tapes, so they were pressed at a temperature of 130°C. The other adhesive tapes were pressed at room temperature (25°C) and at a temperature of 130°C. In addition, the test body was prepared by backing the adhesive tapes using polypropylene film as the substrate with a PET adhesive tape (manufactured by Nitto Denko Corporation, trade name "No.315") as the backing.

(Compression fitting conditions)

Normal temperature crimping: crimp with a 2kg roller, back and forth once.

Heating and pressing: Pressing is performed at 0.4MPa for 5 minutes at a setting of 130℃ on the surface temperature of the bonding device.

The test body made in the above manner was placed in the vertical direction of the lead, and a load of 500g was applied in the downward direction at an ambient temperature of 130°C. The holding force was evaluated by the deflection of the adhesive tape after 1 hour. In addition, the deflection is recorded in Table 1.

<<Double-sided adhesive tape>>

[Implementation Example 18]

Adhesive (1) is obtained in the same manner as in Example 1.

The obtained adhesive was applied onto a release film (a release film treated with polysilicone, manufactured by TORAY, trade name "Cerapeel", thickness: 38μm) in such a way that the thickness of the adhesive layer after drying was 10μm.

The adhesive layer with release film obtained in the above manner was adhered to both sides of a substrate (polyester film, manufactured by TORAY, trade name "Lumirror", thickness 38μm) to obtain a double-sided adhesive tape (18).

[Implementation Example 19]

The adhesive (11) is obtained in the same manner as in Example 13.

The obtained adhesive (11) is applied to one side of a substrate (polyimide film, manufactured by TORAY-DUPONT, trade name "Kapton 100H", thickness 25μm) in such a way that the thickness of the adhesive layer after drying becomes 5μm.

Then, the adhesive (1) is obtained in the same manner as in Example 1.

The obtained adhesive (1) was coated on a release film (a release film treated with polysilicone, manufactured by TORAY, trade name "Cerapeel", thickness: 38μm) in such a way that the thickness of the adhesive layer after drying became 10μm.

The adhesive layer with the release film obtained in the above manner is adhered to the other side of the above substrate to obtain a double-sided adhesive tape (19).

[Example 20]

The adhesive (14) is obtained in the same manner as in Example 16.

The obtained adhesive (14) was applied to one side of a substrate (polypropylene film, manufactured by TORAY, trade name "Torayfan", thickness: 30 μm) in such a way that the thickness of the adhesive layer after drying became 5 μm.

Then, the adhesive (1) is obtained in the same manner as in Example 1.

The obtained adhesive formulation (1) was applied onto a release film (a release film treated with polysilicone, manufactured by TORAY, trade name "Cerapeel", thickness: 38μm) in such a way that the thickness of the adhesive layer after drying became 10μm.

The adhesive layer with the release film obtained in the above manner is adhered to the other side of the above substrate to obtain a double-sided adhesive tape (20).

[Comparison Example 7]

Adhesive (15) was obtained in the same manner as in Comparative Example 1.

The obtained adhesive was applied onto a release film (a release film treated with polysilicone, manufactured by TORAY, trade name "Cerapeel", thickness: 38μm) in such a way that the thickness of the adhesive layer after drying was 10μm.

The adhesive layer with release film obtained in the above manner was attached to both sides of a substrate (polyester film, manufactured by TORAY, trade name "Lumirror", thickness 38μm) to obtain a double-sided adhesive tape (C7).

<Evaluation>

The obtained double-sided adhesive tape was subjected to the following evaluation. The results are shown in Table 3.

(7) Oil resistance evaluation

A polypropylene plate was placed on one side of a double-sided adhesive tape and an aluminum plate was placed on the other side, and the two were pressed at 0.4 MPa for 5 minutes at a setting of 130°C on the surface temperature of the bonding device to prepare a test piece. In addition, regarding the double-sided adhesive tapes of Examples 19 and 20, a polypropylene plate was placed on the side of the adhesive layer formed by the adhesives (11) and (14).

The obtained test piece was immersed in oleic acid at 60°C for 72 hours, and the presence of bulge and peeling of the adhesive tape was visually confirmed.

(8) Alcohol resistance evaluation

Prepare the test piece in the same way as in the above evaluation (7).

The obtained test piece was immersed in 60°C ethanol diluted to 75% by weight with distilled water for 72 hours, and the presence or absence of bulging and peeling of the adhesive tape was visually confirmed.

10: Base material

20: Adhesive layer

100: Adhesive tape

Claims (9)

An adhesive exhibits adhesiveness by compression bonding, and comprises an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25° C. or higher, wherein the acrylic polymer having an acid functional group comprises a structural unit derived from a monomer having an acid functional group, and the content ratio of the structural unit derived from the monomer having an acid functional group is 1.5 parts by weight to 20 parts by weight relative to 100 parts by weight of the acrylic polymer having an acid functional group. Contains structural units derived from (meth) alkyl acrylates having branched alkyl groups, and the content ratio of the structural units derived from (meth) alkyl acrylates having branched alkyl groups is 50 to 100 parts by weight relative to 100 parts by weight of the structural units derived from (meth) alkyl acrylates in the acrylic polymer having acid functional groups, and the above-mentioned crystalline resin is a maleic anhydride-modified polyolefin resin, a maleic acid-modified polyolefin resin, or an acrylic acid-modified polyolefin resin. The adhesive of claim 1 exhibits adhesion by heating. As in the adhesive of claim 1 or 2, the acrylic polymer having an acid functional group contains a structural unit a derived from an alkyl (meth)acrylate having a linear or branched alkyl group with 4 or more carbon atoms. As in the adhesive of claim 3, the content ratio of the structural unit a is 50 parts by weight or more relative to 100 parts by weight of the acrylic polymer having an acid functional group. The adhesive of claim 1 or 2 contains C5 petroleum resin and/or C9 petroleum resin. An adhesive tape comprising an adhesive as claimed in any one of claims 1 to 5. The adhesive tape of claim 6 comprises a substrate and an adhesive layer disposed on at least one side of the substrate, and the adhesive layer comprises an adhesive as in any one of claims 1 to 5. As in claim 7, the adhesive tape, wherein the substrate is formed by at least one selected from polyacrylate, polyurethane, polyimide, polyarylamide, polyamide, ethylene-vinyl alcohol copolymer, polyetherimide, polyvinylidene fluoride, polyester, polypropylene, polyethylene, polyphenylene sulfide. The adhesive tape of claim 7 or 8 has a peeling film disposed on the side of the adhesive layer opposite to the substrate.