WO2020218360A1

WO2020218360A1 - Adhesive tape

Info

Publication number: WO2020218360A1
Application number: PCT/JP2020/017369
Authority: WO
Inventors: 茂樹河邊
Original assignee: 日東電工株式会社
Priority date: 2019-04-26
Filing date: 2020-04-22
Publication date: 2020-10-29

Abstract

Provided are: an adhesive agent in which a reduction in adhesive strength is suppressed when the adhesive agent comes into contact with an oil component or an alcohol component; and an adhesive tape containing the adhesive agent. This adhesive tape includes a substrate and an adhesive layer disposed on at least one side of the substrate. The adhesive layer contains an adhesive agent that exhibits adhesive properties upon pressure bonding. The adhesive agent contains an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25°C or higher. The haze value of the adhesive tape is 20% or less.

Description

Adhesive tape

The present invention relates to an adhesive tape.

Conventionally, adhesive tapes and double-sided tapes have been used for surface protection, insulation protection, member joining or fixing due to their functions by sticking them to various members. However, in the case of applications that come into contact with human hands, secretions such as sebum and hand stains, chemicals such as cosmetics and hair styling products, moisturizing creams and sunscreens, and oils contained in foods and the like tend to adhere through the fingertips. Further, not only oil but also alcohol components such as ethanol contained in perfume, sterilization sheet, rubbing alcohol and the like are components that easily adhere to each other when used in a living environment. In such a usage pattern, when a component such as an oil component or an alcohol component comes into contact with the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, the adhesive strength may decrease and inconvenience such as floating may occur.

JP-A-2009-215355 Japanese Unexamined Patent Publication No. 2013-14985 JP-A-2017-132911

The present invention has been made to solve a conventional problem, and an object of the present invention is to provide an adhesive tape in which a decrease in adhesive strength when in contact with an oil component or an alcohol component is suppressed.

The adhesive tape of the present invention is an adhesive tape comprising a base material and a pressure-sensitive adhesive layer arranged on at least one side of the base material, and the pressure-sensitive adhesive layer contains a pressure-sensitive adhesive that exhibits adhesiveness by pressure bonding. The pressure-sensitive adhesive contains an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25 ° C. or higher, and the haze value of the pressure-sensitive adhesive tape is 20% or less.
In one embodiment, the adhesive tape develops adhesiveness by heating.
In one embodiment, the acrylic polymer having an acid functional group has a structural unit a derived from a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 4 or more carbon atoms. ..
In one embodiment, the content ratio of the structural unit a is 50 parts by weight or more with respect 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-based resin is a maleic anhydride-modified polyolefin-based resin, a maleic acid-modified polyolefin-based resin, or an acrylic-modified polyolefin-based resin.
In one embodiment, the pressure-sensitive adhesive comprises a C5-based petroleum resin and / or a C9-based petroleum resin.
In one embodiment, the substrate is selected from polyacrylate, polyurethane, polyimide, aramid, polyamide, ethylene / vinyl alcohol copolymer, polyetherimide, polyvinylidene fluoride, polyester, polypropylene, polyethylene, polyphenylene sulfide. It is formed from at least one kind.
In one embodiment, a release film is provided on the side of the pressure-sensitive adhesive layer opposite to the base material.
In one embodiment, the pressure-sensitive adhesive layers are arranged on both sides of the base material.

According to the present invention, it is possible to provide an adhesive tape in which a decrease in adhesive strength when in contact with an oil component or an alcohol component is suppressed. In addition, the adhesive tape of the present invention exhibits excellent adhesiveness to both metallic adherends and non-metallic adherends. Further, the adhesive tape of the present invention is excellent in heat resistance and chemical resistance, and can exhibit excellent adhesiveness and bondability in various applications. Further, the adhesive tape of the present invention is characterized in that the haze value is small and the haze value does not change much with time. Such an adhesive tape has advantages such as excellent visibility through the adhesive tape and easy positioning of the adhesive tape.

It is the schematic sectional drawing of the adhesive tape by one Embodiment of this invention.

<< Adhesive tape >>
FIG. 1 is a schematic cross-sectional view of an adhesive tape according to one embodiment of the present invention. The adhesive tape 100 includes a base material 10 and an adhesive layer 20 arranged on at least one side (both sides in the illustrated example) of the base material 10. Although not shown, the adhesive tape is a release film on the outside of the adhesive layer (that is, the surface of the adhesive layer opposite to the substrate) for the purpose of protecting the adhesive surface until it is used. May be provided.

The adhesive layer constituting the adhesive tape exhibits adhesiveness by being pressure-bonded. The adhesive tape (substantially the adhesive layer) may be an adhesive tape that exhibits adhesiveness at room temperature (25 ° C.), or may be an adhesive tape that exhibits adhesiveness by heating. An adhesive tape that develops adhesiveness by heating can exhibit adhesiveness in a state of being cooled to room temperature after heating.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer includes an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25 ° C. or higher. In the present invention, by using an acrylic polymer having an acid functional group in combination with the above crystalline resin, it is excellent in heat resistance and chemical resistance, and the adhesive strength is lowered when it comes into contact with an oil component or an alcohol component. A suppressed adhesive can be obtained. The adhesive tape obtained by using such an adhesive is suitably used for joining a metal material to a metal material, a non-metal material to a non-metal material, and a metal material to a non-metal material. obtain.

Further, in the present invention, by using an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25 ° C. or higher, light scattering is performed even though it is formed by mixing different materials in this way. It is possible to form an adhesive layer having less property and a small haze value. The adhesive tape obtained by using such an adhesive has advantages such as excellent sensor visibility through the adhesive tape and easy positioning of the adhesive tape.

The adhesive strength at 25 ° C. when the adhesive layer of the adhesive tape of the present invention is attached to an aluminum plate is preferably 0.5 N / 10 mm or more, more preferably 0.8 N / 10 mm to 20 N / 10 mm. , More preferably 1N / 10mm to 10N / 10mm. In the present specification, the adhesive strength is the adhesive strength measured by a method according to JIS Z 0237: 2000, and the adhesive tape is attached to an aluminum plate by one reciprocation of a 2 kg roller and left at 25 ° C. for 30 minutes. After that, the adhesive tape is peeled off and measured under the conditions of a peeling angle of 180 ° and a peeling speed (tensile speed) of 300 mm / min. When the adhesive tape is an adhesive tape that develops adhesiveness by heating, it can be attached to the adhesive tape by an adhesive operation (for example, 130 ° C., 0.4 MPa, 5 minutes) at a temperature at which the adhesive tape exhibits adhesiveness. The adhesive strength measured after the aluminum plates are adhered and cooled to 25 ° C. corresponds to the above adhesive strength.

The haze value of the adhesive tape is 20% or less, preferably 18% or less, more preferably 10% or less, further preferably 8% or less, and particularly preferably 5% or less. The smaller the haze value of the adhesive tape is, the more preferable it is, but the lower limit value thereof is, for example, 1%. The haze value of the adhesive tape is the base material type, the structure of the acrylic polymer having an acid functional group (for example, monomer component, molecular weight), the structure of the crystalline resin, and the content of the acrylic polymer having an acid functional group and the crystalline resin. It can be adjusted by adjusting the ratio and the like.

The rate of change in the haze value of the adhesive tape when the adhesive tape is stored at an environmental temperature of 5 ° C. for 72 hours ((haze value after storage for 72 hours-initial haze value) / initial haze value) is preferably 20. % Or less, more preferably 16% or less, still more preferably 10% or less, and particularly preferably 8% or less. The smaller the rate of change is, the more preferable it is, but the lower limit thereof is, for example, 0.1%.

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

<Adhesive layer>
As described above, the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive containing an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25 ° C. or higher.

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

The haze value of the pressure-sensitive adhesive layer is preferably 20% or less, more preferably 18% or less, further preferably 10% or less, particularly preferably 8% or less, and most preferably 5% or less. Is. The smaller the haze value of the pressure-sensitive adhesive layer is, the more preferable it is, but the lower limit value thereof is, for example, 1%.

Rate of change in haze value of the adhesive layer constituting the adhesive tape when the adhesive tape is stored at an environmental temperature of 5 ° C. for 72 hours (((72 storage haze value-initial haze value) / initial haze value) Is preferably 20% or less, more preferably 16% or less, still more preferably 10% or less, and particularly preferably 8% or less. The smaller the rate of change is, the more preferable it is, but the lower limit thereof is, for example, 2%.

The probe tack value of the pressure-sensitive adhesive layer at 25 ° C. is preferably 500 g or less, more preferably 400 g or less, further preferably 340 g or less, and particularly preferably 10 g to 300 g. The method for measuring the probe tack value will be described later.

(Acrylic polymer with acid functional group)
Examples of the acrylic polymer having an acid functional group include an acrylic polymer containing a structural unit derived from one or more (meth) acrylic acid alkyl esters and a structural unit derived from a monomer having an acid functional group. Can be mentioned.

The content ratio of the acrylic polymer having an acid functional group in the pressure-sensitive adhesive is preferably 7 parts by weight to 95 parts by weight, more preferably 15 parts by weight or more, based on 100 parts by weight of the solid content in the pressure-sensitive adhesive. It is 90 parts by weight, more preferably 20 parts by weight to 85 parts by weight, and particularly preferably 40 parts by weight to 85 parts by weight. The content of the acrylic polymer having an acid functional group can be an appropriate amount depending on the adhesiveness and the like. The adhesive may contain an acrylic polymer having no acid functional group in addition to the acrylic polymer having an acid functional group, and may not contain an acrylic polymer having no acid functional group. You may.

The content ratio of the structural unit derived from the (meth) acrylic acid alkyl ester is preferably 50 parts by weight to 99 parts by weight, more preferably 70 parts by weight, based on 100 parts by weight of the acrylic polymer having an acid functional group. It is ~ 98 parts by weight, more preferably 80 parts by weight to 98 parts by weight.

Preferably, the (meth) acrylic acid alkyl ester is linear or branched with 1 to 24 carbon atoms (more preferably 3 to 20, even more preferably 4 to 12, particularly preferably 4 to 8). It has an alkyl group.

Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, butyl (meth) acrylic acid, pentyl (meth) acrylic acid, and (meth). ) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, eikosyl (meth) acrylate and the like.

In one embodiment, the acrylic polymer having an acid functional group has a linear or branched alkyl group having 4 or more carbon atoms (preferably 4 to 12, more preferably 4 to 8). It has a structural unit a derived from (meth) acrylic acid alkyl ester, and the content ratio of the structural unit a is 50 parts by weight or more (preferably 50 parts by weight) with respect to 100 parts by weight of the acrylic polymer having an acid functional group. ~ 99 parts by weight, more preferably 70 parts by weight to 98 parts by weight, still more preferably 80 parts by weight to 98 parts by weight). By using an acrylic polymer having an acid functional group containing the structural unit a in a predetermined amount or more, a pressure-sensitive adhesive having excellent heat resistance and chemical resistance and suppressing a decrease in adhesive strength when in contact with an oil or alcohol component. Can be obtained.

In one embodiment, as the (meth) acrylic acid alkyl ester, a (meth) acrylic acid alkyl ester having a branched alkyl group is used. By using a (meth) acrylic acid alkyl ester having a branched alkyl group, an adhesive tape having excellent chemical resistance can be obtained. The branched alkyl group preferably has 4 or more carbon atoms, more preferably 4 to 12 carbon atoms, and further preferably 4 to 8 carbon atoms. A (meth) acrylic acid alkyl ester having a linear alkyl group and a (meth) acrylic acid alkyl ester having a branched alkyl group may be used in combination. Further, as the (meth) acrylic acid alkyl ester, a (meth) acrylic acid alkyl ester having a branched alkyl group may be used alone.

In one embodiment, in the 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 is the constitution derived from the (meth) acrylic acid alkyl ester. It is preferable with respect to 100 parts by weight of the unit (that is, 100 parts by weight of 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). It is 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 the (meth) acrylic acid alkyl ester having a branched alkyl group include isobutyl (meth) acrylic acid, sec-butyl (meth) acrylic acid, t-butyl (meth) acrylic acid, and 2-butyl (meth) acrylic acid. Examples thereof include ethylhexyl, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, 2-methylbutyl (meth) acrylate and the like. Of these, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate or isodecyl (meth) acrylate are preferable, and 2-ethylhexyl (meth) acrylate is more preferable. .. By using 2-ethylhexyl (meth) acrylate, it is possible to obtain a pressure-sensitive adhesive in which a decrease in adhesive strength when in contact with an oil component or an alcohol component is suppressed.

Examples of the acid functional group contained in the acrylic polymer having an acid functional group include a carboxyl group, an acid anhydride group, a phosphoric acid group, and a sulfonic acid group. Therefore, examples of the monomer having an acid functional group include a carboxyl group-containing monomer, an acid anhydride group-containing monomer, a phosphoric acid group-containing monomer, and a sulfonic acid group-containing monomer. Of these, a carboxyl group-containing monomer is preferable. If a carboxyl group-containing monomer is used, the adhesive force to the metal plate is easily developed, and in terms of design and production, it is easy to copolymerize with other acrylic monomers, and the polymer formed by the copolymerization is crosslinked. It has the characteristic of being easy.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Of these, acrylic acid is preferable.

The content ratio of the structural unit derived from the monomer having an acid functional group is preferably 1.5 parts by weight to 20 parts by weight, more preferably 1. parts by weight, based on 100 parts by weight of the acrylic polymer having an acid functional group. It is 8 parts by weight to 15 parts by weight, more preferably 2 parts by weight to 10 parts by weight.

The acrylic polymer having an acid functional group may be combined with the (meth) acrylic acid alkyl ester and / or a monomer having an acid functional group, if necessary, for the purpose of modifying the cohesiveness, heat resistance, crosslinkability and the like. It may contain structural units derived from other copolymerizable monomers. Such other monomers include, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, etc. Hydroxyl group-containing monomers such as hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methylmethacrylate; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (N-substituted) amide-based monomers such as (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; aminoethyl (meth) acrylate, N, N-dimethyl (meth) acrylate. Aminoalkyl-based (meth) acrylates such as aminoethyl and t-butylaminoethyl (meth) acrylate; alkoxyalkyl-based (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate. Monomer: Maleimide-based monomers such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide, N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide , N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide and other itaconimide-based monomers; N- (meth) acryloyloxymethylene succinimide, N- (meth) accurloyl-6-oxyhexamethylenesuccinimide, Succinimide-based monomers such as N- (meth) acryloyl-8-oxyoctamethylene succinimide; vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinyl Vinyl-based monomers such as pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholin, N-vinylcarboxylic acid amides, styrene, α-methyl styrene, N-vinyl caprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; (meth) Acrylic monomer containing epoxy group such as glycidyl acrylate; (meth) polyethylene glycol acrylate, (meth) acrylic Glycol-based acrylic ester monomers such as polypropylene glycol acetate, methoxyethylene glycol (meth) acrylate, and methoxypolypropylene glycol (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate. Acrylate-based monomers having a heterocycle such as, halogen atom, silicon atom, etc .; hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropanthry (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate Polyfunctional monomers such as; olefin-based monomers such as isoprene, butadiene, and isobutylene; vinyl ether-based monomers such as vinyl ether, and the like. These monomer components may be used alone or in combination of two or more.

The content ratio of the structural unit derived from the other monomer is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, still more preferably 10 parts by weight, based on 100 parts by weight of the acrylic polymer having an acid functional group. It is 5 parts by weight or less.

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

(Crystalline resin)
As described above, the pressure-sensitive adhesive of the present invention contains a crystalline resin. The crystalline resin refers to a resin having a clear endothermic peak (half width within 15 ° C.) in the differential calorimetry curve measured by a differential scanning calorimeter (DSC).

The content ratio of the crystalline resin in the pressure-sensitive adhesive is preferably 3 parts by weight to 90 parts by weight, more preferably 10 parts by weight to 85 parts by weight, based on 100 parts by weight of the solid content in the pressure-sensitive adhesive. More preferably, it is 15 to 80 parts by weight.

The melting point of the crystalline resin is 25 ° C. or higher, more preferably 40 ° C. or higher, further preferably 60 ° C. to 120 ° C., and particularly preferably 60 ° C. to 100 ° C. Within such a range, it is possible to obtain a pressure-sensitive adhesive which is excellent in heat resistance and chemical resistance and whose adhesive strength is suppressed from being lowered when it comes into contact with an oil component or an alcohol component. The melting point can be measured by differential scanning calorimetry (DSC).

The weight average molecular weight of the crystalline resin is preferably 50,000 to 1,500,000, more preferably 70,000 to 1,000,000.

The crystallinity of the crystalline resin is preferably 10% or more, more preferably 20% or more. Crystallinity can typically 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, and ethylene-. 1-Heptene copolymer, ethylene-1-octene copolymer, ethylene-1-nonene copolymer, ethylene-1-decene copolymer, ethylene-1-undecene copolymer, ethylene-1-dodecene Polymer, ethylene-1-tridecene copolymer, ethylene-1-tetradecene copolymer, ethylene-1-pentadecene copolymer, ethylene-1-hexadecene copolymer, ethylene-1-heptadecene copolymer, ethylene- Ethylene-α-olefin copolymers such as 1-octadecene copolymer, ethylene-1-nanodecene copolymer, ethylene-1-eicosene copolymer; ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer Ethylene-vinyl ester copolymers such as coalesced; ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer and the like-ethylene- An unsaturated carboxylic acid alkyl ester copolymer; a propylene-based resin and the like can be mentioned.

In one embodiment, a crystalline polypropylene-based resin is used as the crystalline resin. The crystalline polypropylene-based resin may be a homopolymer, or may be a copolymer obtained from propylene and a monomer copolymerizable with propylene. Examples of the monomer copolymerizable with propylene include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, 3-methyl-1-pentene and the like. Α-olefin and the like. In the crystalline polypropylene resin, the content ratio of the constituent unit 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%. Is. In the crystalline polypropylene resin, the content ratio of the constituent unit derived from α-olefin is preferably 1 mol% to 15 mol%, more preferably 1 mol% to 10 mol%.

In one embodiment, a modified polyolefin resin is used as the crystalline resin. When the modified polyolefin resin is used, the phase separation between the crystalline resin and the acrylic polymer having an acid functional group is suppressed, and a pressure-sensitive adhesive layer having less bleeding and excellent transparency can be formed. As the modified polyolefin-based resin, maleic anhydride-modified polyolefin-based resin, maleic acid-modified polyolefin-based resin, acrylic-modified polyolefin-based resin and the like can be preferably used. Specific examples thereof include resins obtained by modifying the above-mentioned polyolefin resin with maleic anhydride, maleic acid or acrylic. Of these, a maleic anhydride polyolefin resin is preferable, and a maleic anhydride modified propylene resin is more preferable. Specific examples of the maleic anhydride-modified propylene resin include a resin obtained by modifying the crystalline polypropylene resin with maleic anhydride. The modification rate of the modified polyolefin resin is preferably 1% by weight to 5% by weight, more preferably 1.5% by weight to 2% by weight.

(Additive)
The pressure-sensitive adhesive may optionally contain any suitable additive. Examples of the additive include a cross-linking agent, a tackifier, a plasticizer (for example, a trimellitic acid ester-based plasticizer, a pyromellitic acid ester-based plasticizer), a pigment, a dye, a filler, an antiaging agent, and a conductive material. , Ultraviolet absorbers, light stabilizers, release modifiers, softeners, surfactants, flame retardants, antioxidants, solvents and the like. In addition, the pressure-sensitive adhesive may contain any suitable solvent.

As the tackifier, any suitable tackifier is used. As the tackifier, for example, a tackifier resin is used. Specific examples of the tackifier resin include rosin-based tackifier resins (eg, unmodified rosin, modified rosin, rosinphenol-based resins, rosin ester-based resins, etc.) and terpene-based tackifier resins (eg, terpene-based resins, terpenphenols). Rosin, styrene-modified terpene resin, aromatic-modified terpene resin, hydrogenated terpene resin), hydrocarbon-based tackifier resin (for example, aliphatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin, aromatic resin) Hydrocarbon resins (for example, styrene resins, xylene resins, etc.), aliphatic / aromatic petroleum resins, aliphatic / alicyclic petroleum resins, hydrogenated hydrocarbon resins, kumaron resins, kumaron inden resins , Etc.), phenol-based tackifier resins (eg, alkylphenol-based resins, xyleneformaldehyde-based resins, resoles, novolak, etc.), ketone-based tackifier resins, polyamide-based tackifier resins, epoxy-based tackifier resins, elastomeric tackifier resins, etc. Can be mentioned.

In one embodiment, as the pressure-sensitive adhesive, a C5-based petroleum resin and / or a C9-based petroleum resin is used as the tackifier. By using these tackifiers, a pressure-sensitive adhesive having excellent sebum resistance and alcohol resistance can be obtained.

The softening point of the tackifier is preferably 70 ° C. to 200 ° C., more preferably 80 ° C. to 190 ° C. Within such a range, a pressure-sensitive adhesive layer in which the storage elastic modulus and the loss elastic modulus are appropriately adjusted can be obtained.

The content ratio of the tackifier is preferably 5 parts by weight to 50 parts by weight with respect 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 25 ° C. or higher. , More preferably 10 to 40 parts by weight.

Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, melamine-based cross-linking agents, peroxide-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, metal chelate-based cross-linking agents, and metals. Examples thereof include salt-based cross-linking agents, carbodiimide-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, and amine-based cross-linking agents. Of these, an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, or a metal chelate-based cross-linking agent is preferable.

Specific examples of the isocyanate-based cross-linking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; 2,4- Aromatic isocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"), tri Methylolpropane / hexamethylene diisocyanate trimeric adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL"), isocyanurate of hexamethylene diisocyanate (manufactured by Japan Polyurethane Industry Co., Ltd., trade name "Coronate HX"), etc. Isocyanate adduct; etc. The content of the isocyanate-based cross-linking agent can be set to an arbitrary appropriate amount according to the desired adhesive strength and elastic modulus, and the acrylic polymer having an acid functional group and the crystalline resin having a melting point of 25 ° C. or higher are used. It is typically 0.1 parts by weight to 20 parts by weight, more preferably 0.5 parts by weight to 10 parts by weight, based on 100 parts by weight of the total amount.

Examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylene diamine, diglycidyl aniline, and 1,3-bis (N, N-glycidyl aminomethyl) cyclohexane (Mitsubishi Gas). Chemical Co., Ltd., trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (Kyoeisha Chemical Co., Ltd., trade name "Epolite 1600"), neopentyl glycol diglycidyl ether (Kyoeisha Chemical Co., Ltd., trade name " Epolite 1500NP "), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolite 40E "), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolite 70P "), polyethylene glycol diglycidyl ether (Japan Oil and fat company, product name "Epiol E-400"), polypropylene glycol diglycidyl ether (Japan Oil and Fat Co., product name "Epiol P-200"), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product 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, product name" Denacol EX " -512 "), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipate diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcin diglycidyl ether, bisphenol Examples thereof include -S-diglycidyl ether and epoxy resins having two or more epoxy groups in the molecule. The content of the epoxy-based cross-linking agent can be set to an arbitrary appropriate amount according to the desired adhesive strength and elastic modulus, and the acrylic polymer having an acid functional group and the crystalline resin having a melting point of 25 ° C. or higher are used. It is typically 0.01 parts by weight to 10 parts by weight, more preferably 0.03 parts by weight to 5 parts by weight, based on 100 parts by weight of the total amount.

As the metal chelate-based cross-linking agent, for example, a metal chelate compound in which the metal atom is aluminum, zirconium, titanium, zinc, iron, tin or the like can be used. Of these, an aluminum chelate compound or a titanium chelate compound portion is preferable.

Examples of the aluminum chelate compound include diisopropoxyaluminum monooleylacetate, monoisopropoxyaluminum bisoleylacetate, monoisopropoxyaluminum monooleate monoethylacetate, diisopropoxyaluminum monolaurylacetate, and diisopropoxy. Aluminum Monostearyl Acetate, Diisopropoxy Aluminum Monoisostearyl Acetate, Monoisopropoxy Aluminum Mono-N-Lauroyl-β-Alanate Monolauryl Acetate, Aluminum Tris (Acetylacetone), Acetylacetonate Aluminum Bis (Ethyl) Acetylacetone), monoacetylacetone aluminum bis (isobutylacetate) chelate, monoacetylacetone aluminum bis (2-ethylhexylacetate) chelate, monoacetylacetone aluminum bis (dodecylacetacetate) chelate, monoacetylacetone aluminum Examples include bis (oleylacetoneacetate) chelate.

Examples of the titanium chelate compound include titanium diisopropoxybis (acetylacetoneate), titaniumtetra-n-butyrate, titaniumtetra-2-ethylhexanonate, titaniumtetraacetylacetoneate, and titaniumdiisopropoxybis (ethylacetate). Acetate), titanium octylene glycolate and the like.

Examples of other metal chelate compounds include zirconium tetraacetylacetonate and zirconium tributoxymonoacetylacetoneate.

The above-mentioned metal chelate-based cross-linking agent may be used alone or in combination of two or more.

The content of the metal chelate-based cross-linking agent can be set to an arbitrary appropriate amount according to the desired adhesive strength and elasticity, and is crystalline with an acrylic polymer having an acid functional group and having a melting point of 25 ° C. or higher. It is typically 0.01 to 10 parts by weight, more preferably 0.03 to 7 parts by weight, still more preferably 0.05 parts by weight, based on 100 parts by weight of the total amount with the resin. Parts to 5 parts by weight.

<Base material>
A resin film is preferably used as the base material. Examples of the resin constituting the resin film include polyacrylate, polyurethane, polyimide, aramid, polyamide, ethylene / vinyl alcohol copolymer, polyetherimide, polyvinylidene fluoride, polyester, polypropylene, polyethylene, polyphenylene sulfide and the like. .. These resins may be used alone or in combination of two or more.

The thickness of the base material is preferably 1 μm to 100 μm, more preferably 10 μm to 70 μm, and further preferably 15 μm to 50 μm.

The haze value of the base material is preferably 20% or less, more preferably 18% or less, further preferably 10% or less, particularly preferably 8% or less, and most preferably 5% or less. is there. The smaller the haze value of the base material, the more preferable, but the lower limit value thereof is, for example, 1%.

Rate of change in haze value of the base material constituting the adhesive tape when the adhesive tape is stored at an environmental temperature of 5 ° C. for 72 hours ((haze value after storage for 72 hours-initial haze value) / initial haze value) Is preferably 20% or less, more preferably 16% or less, still more preferably 10% or less, and particularly preferably 8% or less. The smaller the rate of change is, the more preferable it is, but the lower limit thereof is, for example, 2%, preferably 0.1%.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The evaluation method in the examples is as follows. Further, in the examples, unless otherwise specified, "parts" and "%" are based on weight.

<< Single-sided adhesive tape >>
[Example 1]
2-Ethylhexyl acrylate / acrylic acid (95 parts by weight / 5 parts by weight) in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas introduction tube, and cooler, 0.2 part by weight of benzoyl peroxide as an initiator , 120 parts by weight of ethyl acetate was charged, nitrogen gas was introduced while gently stirring, and the polymerization reaction was carried out for about 6 hours while keeping the liquid temperature in the flask at around 60 ° C., and the acrylic acid-based common weight having a weight average molecular weight of 1.3 million was carried out. The coalescence (1) was obtained.
Acrylic copolymer (1) With respect to 75 parts by weight, as a modified olefin resin, a maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyo Tuck PMA-L", weight average molecular weight 7. Add 25 parts by weight of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L") and dilute with toluene to prepare a pressure-sensitive adhesive (1) having a solid content of 15%. did.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , Adhesive tape (1) was obtained.

[Example 2]
An adhesive (2) was obtained in the same manner as in Example 1 except that the amount of the isocyanate-based cross-linking agent (manufactured by Tosoh Corporation, trade name “Coronate L”) was 3 parts by weight.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , Adhesive tape (2) was obtained.

[Example 3]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Acrylic copolymer (1) 75 parts by weight, as a modified olefin resin, maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyo Tuck PMA-L", weight average molecular weight 7 .50,000, melting point 70 ° C) 25 parts by weight, hydrogenated derivative of C9 petroleum resin (manufactured by Arakawa Chemical Industry Co., Ltd., trade name "Arcon P-125", hydrogenation rate: 95%, softening point: 125 ° C) 30 A pressure-sensitive adhesive (3) having a solid content of 15% was prepared by adding 2 parts by weight and 2 parts by weight of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name “Coronate L”) and diluting with toluene.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , Adhesive tape (3) was obtained.

[Example 4]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight: 7) as a modified olefin resin with respect to 75 parts by weight of the acrylic copolymer (1). .50,000, melting point: 90 ° C.) 25 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (4) Was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 12 μm) so that the thickness of the adhesive layer after drying is 20 μm. , Adhesive tape (4) was obtained.

[Example 5]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight: 7) as a modified olefin resin with respect to 85 parts by weight of the acrylic copolymer (1). .50,000, melting point: 90 ° C.) 15 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (5) Was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 12 μm) so that the thickness of the adhesive layer after drying is 5 μm. , An adhesive tape (5) was obtained.

[Example 6]
As a base material, a polyester film having a thickness of 50 μm (manufactured by Toray Industries, Inc., trade name “Lumilar”) was used, and the adhesive tape (6) was the same as in Example 4 except that the thickness of the adhesive layer was 20 μm. Was produced.

[Example 7]
2-Ethylhexyl acrylate / acrylic acid (90 parts by weight / 10 parts by weight) in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas introduction tube, and cooler, 0.2 part by weight of benzoyl peroxide as an initiator , 120 parts by weight of ethyl acetate was charged, nitrogen gas was introduced while gently stirring, and the polymerization reaction was carried out for about 6 hours while keeping the liquid temperature in the flask at around 60 ° C., and the weight average molecular weight was 1.2 million acrylic acid-based common weight. The coalescence (2) was obtained.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 85 parts by weight of the acrylic copolymer (2). .50,000, melting point: 70 ° C.) 15 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (6) Was prepared.
The obtained adhesive is applied onto a base material (polyimide film, manufactured by Toray Industries, Inc., trade name "Kapton 100H", thickness: 25 μm) so that the thickness of the adhesive layer after drying is 10 μm. , An adhesive tape (7) was obtained.

[Example 8]
An adhesive tape (8) was used as a base material in the same manner as in Example 7 except that a polyester film having a thickness of 50 μm (manufactured by Toray Industries, Inc., trade name “Lumilar”) was used and the thickness of the adhesive layer was 50 μm. Was produced.

[Example 9]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-Lz", weight average molecular weight: 10) as a modified olefin resin with respect to 75 parts by weight of the acrylic copolymer (1). Add 25 parts by weight of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L") and dilute with toluene to prepare an adhesive (7) with a solid content of 15%. did.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , An adhesive tape (9) was obtained.

[Example 10]
2-Ethylhexyl acrylate / acrylic acid (100 parts by weight / 2 parts by weight) in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas introduction tube, and cooler, 0.2 part by weight of benzoyl peroxide as an initiator , 230 parts by weight of ethyl acetate was charged, nitrogen gas was introduced while gently stirring, and the polymerization reaction was carried out for about 6 hours while keeping the liquid temperature in the flask at around 60 ° C., and the weight average molecular weight of acrylic acid was 650,000. The coalescence (3) was obtained.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 70 parts by weight of the acrylic copolymer (3). .50,000, melting point: 70 ° C.) 30 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (8) Was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , An adhesive tape (10) was obtained.

[Example 11]
N-butyl acrylate / ethyl acrylate / acrylic acid (70 parts by weight / 25 parts by weight / 5 parts by weight) as an initiator in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. 0.2 parts by weight of benzoyl peroxide and 120 parts by weight of ethyl acetate were charged, nitrogen gas was introduced while gently stirring, the liquid temperature in the flask was maintained at around 60 ° C., and the polymerization reaction was carried out for about 6 hours, and the weight average was obtained. An acrylic copolymer (4) having a molecular weight of 700,000 was obtained.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 85 parts by weight of the acrylic copolymer (4). .50,000, melting point: 70 ° C.) 15 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (9) Was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , An adhesive tape (11) was obtained.

[Example 12]
N-butyl / acrylic acid (95 parts by weight / 5 parts by weight) acrylate in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas introduction tube, and cooler, 2,2'-azobisiso as an initiator 0.2 parts by weight of butyronitrile and 233 parts by weight of ethyl acetate were charged, nitrogen gas was introduced while gently stirring, the liquid temperature in the flask was maintained at around 60 ° C., and the polymerization reaction was carried out for about 6 hours, and the weight average was obtained. An acrylic copolymer (5) having a molecular weight of 700,000 was obtained.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 85 parts by weight of the acrylic copolymer (5). .50,000, melting point: 70 ° C.) 15 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (10) Was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 15 μm. , An adhesive tape (12) was obtained.

[Example 13]
An acrylic copolymer (2) was obtained in the same manner as in Example 7.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 25 parts by weight of the acrylic copolymer (2). Add 75 parts by weight of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), dilute with toluene, and add a pressure-sensitive adhesive (11) having a solid content of 15%. Prepared.
The obtained adhesive is applied onto a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 12 μm) so that the thickness of the adhesive layer after drying is 3 μm. An adhesive tape (13) was obtained.

[Example 14]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 25 parts by weight of the acrylic copolymer (1). Add 75 parts by weight of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), dilute with toluene, and add a pressure-sensitive adhesive (12) having a solid content of 15%. Prepared.
The obtained adhesive is applied onto a base material (polyester film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness: 50 μm) so that the thickness of the adhesive layer after drying is 25 μm, and the adhesive is adhered. A tape (14) was obtained.

[Example 15]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotac PMA-T", weight average molecular weight: 7) as a modified olefin resin with respect to 15 parts by weight of the acrylic copolymer (1). .50,000, melting point: 90 ° C.) 85 parts by weight, 2 parts by weight of isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), diluted with toluene, adhesive with a solid content of 15% (13) Was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , An adhesive tape (15) was obtained.

[Example 16]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-L", weight average molecular weight 7) as a modified olefin resin with respect to 85 parts by weight of the acrylic copolymer (1). Add 15 parts by weight of an aluminum chelate-based cross-linking agent (trade name "Aluminum Chelate A", manufactured by Kawaken Fine Chemicals Co., Ltd.), dilute with toluene, and have a solid content of 15 parts. %% Adhesive (14) was prepared.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 20 μm. , An adhesive tape (16) was obtained.

[Example 17]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-L", weight average molecular weight 7) as a modified olefin resin with respect to 15 parts by weight of the acrylic copolymer (1). Add 85 parts by weight of an aluminum chelate-based cross-linking agent (trade name "Aluminum Chelate A", manufactured by Kawaken Fine Chemicals Co., Ltd.), dilute with toluene, and have a solid content of 15 parts. %% Adhesive (15) was prepared.
The obtained adhesive is applied onto a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 5 μm. , An adhesive tape (17) was obtained.

[Example 18]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-T", weight average molecular weight 7) as a modified olefin resin with respect to 25 parts by weight of the acrylic copolymer (1). .50,000, 75 parts by weight of melting point 90 ° C., 0.1 part by weight of epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemicals, trade name "Tetrad C"", diluted with toluene, adhesive with a solid content of 15% ( 16) was prepared.
The obtained adhesive is applied onto a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 5 μm. , An adhesive tape (18) was obtained.

[Comparative Example 1]
As a modified olefin resin, 100 parts by weight of a 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.) is used with toluene. A pressure-sensitive adhesive (C1) having a solid content of 15% was prepared by dissolving.
The obtained adhesive is coated on a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. , An adhesive tape (C1) was obtained.

[Comparative Example 2]
2-Ethylhexyl acrylate / 2-hydroxyethyl acrylate (100 parts by weight / 4 parts by weight) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 2,2'as an initiator -Add 0.2 parts by weight of azobisisobutyronitrile and 233 parts by weight of ethyl acetate, introduce nitrogen gas with gentle stirring, keep the liquid temperature in the flask at around 60 ° C, and carry out the polymerization reaction for about 6 hours. This was carried out to obtain an acrylic copolymer (6) having a weight average molecular weight of 550,000.
Maleic anhydride-modified propylene-butene copolymer resin (manufactured by Toyo Boseki Co., Ltd., trade name "Toyotack PMA-L", weight average molecular weight: 7) as a modified olefin resin with respect to 85 parts by weight of the acrylic copolymer (6). Add 15 parts by weight of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L"), dilute with toluene, and add a pressure-sensitive adhesive (C2) having a solid content of 15%. Prepared.
The obtained adhesive is applied onto a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness 30 μm) so that the thickness of the adhesive layer after drying is 10 μm. An adhesive tape (C2) was obtained.

[Comparative Example 3]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
Acrylic copolymer (1) 25 parts by weight of polyisobutylene resin (manufactured by BASF, trade name "OPPANOL 12SFN", weight average molecular weight: 51,000), isocyanate-based crosslinked as an olefin resin with respect to 75 parts by weight of the acrylic copolymer (1). Two parts by weight of an agent (manufactured by Toso Co., Ltd., trade name "Coronate L") was added and diluted with toluene to prepare a pressure-sensitive adhesive (C3) having a solid content of 15%.
The obtained adhesive is applied onto a base material (polyester film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness: 50 μm) so that the thickness of the adhesive layer after drying is 20 μm. An adhesive tape (C3) was obtained.

[Comparative Example 4]
An adhesive tape (C4) was used as a base material in the same manner as in Comparative Example 3 except that a polypropylene film having a thickness of 30 μm (manufactured by Toray Industries, Inc., trade name “Trefan”) was used and the thickness of the adhesive layer was 10 μm. ) Was prepared.

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

(1) Adhesive strength (against aluminum plate)
A test piece was obtained by adhering the adhesive tapes obtained in Examples and Comparative Examples to the surface of an aluminum plate under the following conditions. Since the adhesive tapes of Example 13, Example 14, Example 15, Example 17, Example 18, and Comparative Example 1 are thermocompression-bonded adhesive tapes, they are pressure-bonded only by heating (130 ° C.). Adhesive tapes other than the above were pressure-bonded at room temperature (25 ° C) and heating (130 ° C), respectively.
For the obtained test piece, use a precision universal testing machine (trade name "Autograph AG-I", manufactured by Shimadzu Corporation) to apply the force (N / 10 mm) required to peel the adhesive tape from the aluminum plate surface. The adhesive strength of the adhesive tape was measured under the following conditions.
(Crimping conditions)
Room temperature crimping: 2kg roller crimping with one reciprocation.
Warm crimping: Crimping at 0.4 MPa x 5 minutes with the surface temperature of the laminating device set to 130 ° C.
(Peeling condition)
Temperature: Normal temperature (25 ° C)
Peeling speed: 300 mm / min
Peeling angle: 180 °

(2) Adhesive strength (against polypropylene plate)
The adhesive strength of the adhesive tape was measured in the same manner as in the above evaluation (1) except that the aluminum plate was replaced with the polypropylene plate.

(3) Oil resistance Specimens were obtained in the same manner as in (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 floating and peeling of the adhesive tape was visually confirmed. Further, the test piece from which the adhesive tape did not peel off was allowed to stand for 30 minutes in an environment of 23 ° C. and 50% RH after wiping off oleic acid. Then, the adhesive strength of the adhesive tape (adhesive strength after immersion in oleic acid) was measured by the same method as in (1) above. Oleic acid was adopted as a pseudo sebum.

(4) Alcohol resistance Specimens were obtained in the same manner as in (1) and (2) above.
The obtained test piece was immersed in ethanol at 60 ° C. diluted to 75% by weight with distilled water for 72 hours, and the presence or absence of floating and peeling of the adhesive tape was visually confirmed. Further, the test piece from which the adhesive tape did not peel off was allowed to stand for 30 minutes in an environment of 23 ° C. and 50% RH after wiping off oleic acid. Then, the adhesive strength of the adhesive tape (adhesive strength after immersion in ethanol) was measured by the same method as in (1) above. Ethanol was adopted as a pseudo-rubbing alcohol.

(5) Haze value The haze value of the adhesive tape was measured by using a haze meter (model number: HM-150, manufactured by Murakami Color Research Institute) by injecting incident light from the surface side of the adhesive layer.
Further, the adhesive tape was stored in an environment of 5 ° C. for 72 hours, and the rate of change in the haze value ((haze value after storage for 72 hours-initial haze value) / initial haze value) was determined.

(6) Holding Force Test A test piece (crimping area: 10 mm × 20 mm) was obtained by adhering the adhesive tapes obtained in Examples and Comparative Examples to a SUS304BA plate under the following conditions. Since the adhesive tapes of Example 13, Example 14, Example 15, Example 17, Example 18, and Comparative Example 1 are thermocompression-bonded adhesive tapes, they are pressure-bonded by heating (130 ° C.), and other than that. The adhesive tape was pressure-bonded at room temperature (25 ° C.) and heating (130 ° C.), respectively. An adhesive tape using a polypropylene film as a base material was lined with a PET adhesive tape (manufactured by Nitto Denko KK, trade name "No. 315") to prepare a test piece.
(Crimping conditions)
Room temperature crimping: 2kg roller crimping with one reciprocation.
Warm crimping: Crimping at 0.4 MPa x 5 minutes with the surface temperature of the laminating device set to 130 ° C.
The test piece prepared as described above was erected in the vertical direction, a load of 500 g was applied downward under an environmental temperature of 130 ° C., and the holding power was evaluated from the amount of displacement of the adhesive tape after 1 hour. In Table 1, the amount of deviation is shown.

<< Double-sided adhesive tape >>
[Example 19]
The adhesive (1) was obtained in the same manner as in Example 1.
The obtained adhesive is applied onto a release film (silicone-treated release film, manufactured by Toray Industries, Inc., trade name "therapy", thickness: 38 μm) so that the thickness of the adhesive layer after drying is 10 μm. Worked.
The adhesive layer with the release film obtained as described above is bonded to both sides of the base material (polyester film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness 38 μm), and double-sided adhesive tape (19). ) Was obtained.

[Example 20]
An adhesive (12) was obtained in the same manner as in Example 14.
The obtained adhesive (12) was applied to one surface of a base material (polyimide film, manufactured by Toray DuPont, trade name "Kapton 100H", thickness 25 μm), and the thickness of the adhesive layer after drying was 5 μm. I painted it so that it would be.
Then, the adhesive (1) was obtained in the same manner as in Example 1.
The obtained adhesive (1) is placed on a release film (silicone-treated release film, manufactured by Toray Industries, Inc., trade name "therapy", thickness: 38 μm) so that the thickness of the adhesive layer after drying is 10 μm. And painted.
The pressure-sensitive adhesive layer with the release film obtained as described above was bonded to the other surface of the base material to obtain a double-sided pressure-sensitive adhesive tape (20).

[Example 21]
The pressure-sensitive adhesive (15) was prepared in the same manner as in Example 17.
The obtained adhesive (15) is applied to one surface of a base material (polypropylene film, manufactured by Toray Industries, Inc., trade name "Trefan", thickness: 30 μm), and the thickness of the adhesive layer after drying is 5 μm. I painted it like this.
Then, the pressure-sensitive adhesive compounding liquid (1) was obtained in the same manner as in Example 1.
The obtained adhesive compounding solution (1) is placed on a release film (silicone-treated release film, manufactured by Toray Industries, Inc., trade name "Therapeu", thickness: 38 μm), and the thickness of the adhesive layer after drying is 10 μm. It was painted as follows.
The pressure-sensitive adhesive layer with the release film obtained as described above was bonded to the other surface of the base material to obtain a double-sided pressure-sensitive adhesive tape (21).

[Comparative Example 5]
An acrylic copolymer (1) was obtained in the same manner as in Example 1.
To 100 parts by weight of the acrylic copolymer (1), 2 parts by weight of an isocyanate-based cross-linking agent (manufactured by Tosoh Corporation, trade name "Coronate L") is added, diluted with toluene, and a pressure-sensitive adhesive having a solid content of 15% ( C5) was prepared.
The obtained adhesive is applied on a release film (silicone-treated release film, manufactured by Toray Industries, Inc., trade name "therapy", thickness: 38 μm) so that the thickness of the adhesive layer after drying is 10 μm. did.
The adhesive layer with the release film obtained as described above is bonded to both sides of the base material (polyester film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness 38 μm), and double-sided adhesive tape (C5). ) Was obtained.

<Evaluation>
The obtained double-sided adhesive tape was subjected to the above (5) and the following evaluations. The results are shown in Table 2.

(7) Oil resistance evaluation A polypropylene plate is placed on one side of the double-sided adhesive tape, an aluminum plate is placed on the other side, and the bonding device surface temperature is set to 130 ° C. at 0.4 MPa x 5 minutes. A test piece was prepared by crimping. In the double-sided adhesive tapes of Examples 20 and 21, a polypropylene plate was arranged on the side of the adhesive layer formed from the adhesives (12) and (15).
The obtained test piece was immersed in oleic acid at 60 ° C. for 72 hours, and the presence or absence of floating and peeling of the adhesive tape was visually confirmed.

(8) Alcohol resistance evaluation A test piece was prepared in the same manner as in the above evaluation (7).
The obtained test piece was immersed in ethanol at 60 ° C. diluted to 75% by weight with distilled water for 72 hours, and the presence or absence of floating and peeling of the adhesive tape was visually confirmed.

10 Base material 20 Adhesive layer 100 Adhesive tape

Claims

An adhesive tape comprising a base material and an adhesive layer arranged on at least one side of the base material.
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive that develops adhesiveness by pressure bonding.
The pressure-sensitive adhesive contains an acrylic polymer having an acid functional group and a crystalline resin having a melting point of 25 ° C. or higher.
The haze value of the adhesive tape is 20% or less.
Adhesive tape.
The adhesive tape according to claim 1, which develops adhesiveness by heating.
According to claim 1 or 2, the acrylic polymer having an acid functional group has a structural unit a derived from a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 4 or more carbon atoms. The listed adhesive tape.
The adhesive tape according to claim 3, wherein the content ratio of the structural unit a is 50 parts by weight or more with respect to 100 parts by weight of the acrylic polymer having an acid functional group.
The adhesive tape according to any one of claims 1 to 4, wherein the crystalline resin is a polyolefin resin.
The adhesive tape according to claim 5, wherein the polyolefin-based resin is a maleic anhydride-modified polyolefin-based resin, a maleic acid-modified polyolefin-based resin, or an acrylic-modified polyolefin-based resin.
The adhesive tape according to any one of claims 1 to 6, wherein the adhesive contains a C5 petroleum resin and / or a C9 petroleum resin.
The substrate is formed from at least one selected from polyacrylate, polyurethane, polyimide, aramid, polyamide, ethylene / vinyl alcohol copolymer, polyetherimide, polyvinylidene fluoride, polyester, polypropylene, polyethylene and polyphenylene sulfide. , The adhesive tape according to any one of claims 1 to 7.
The adhesive tape according to any one of claims 1 to 8, wherein a release film is provided on the side of the adhesive layer opposite to the base material.
The adhesive tape according to any one of claims 1 to 9, wherein the pressure-sensitive adhesive layers are arranged on both sides of the base material.