JP6688839B2 - Adhesive sheet and laminate containing the adhesive sheet - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a pressure-sensitive adhesive sheet having excellent adhesiveness to the surface of an adherend on which oil is attached, and a laminate including the pressure-sensitive adhesive sheet.

  Since metals such as iron and copper easily generate rust, rust preventive oil is usually applied to the surfaces of these metals for the purpose of preventing oxidation due to contact with air. When processing metals, processing oils, cutting oils, machine oils, press oils, etc. are used, so industrial metals used for automobiles, home appliances, and building materials have such oils on their surfaces. Often contaminated.

  Further, in a wide range of industrial fields such as automobiles, home appliances, and building materials, various adhesive tapes and sheets are used when joining materials together and when attaching protective films, labels, etc. to materials. . However, these pressure-sensitive adhesive materials such as pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets cannot exhibit sufficient adhesive force when water, oil, dust, dust, etc. are adhered to the surface of the adherend. Therefore, it is necessary to remove water, oil, dust, dust, etc. on the surface of the adherend in advance.

  When the industrial metals as described above are contaminated with oil, a washing / degreasing step for removing the oil is usually required, which increases labor and costs due to an increase in the number of steps. Therefore, even if the metal surface is contaminated with oil, there is a demand for a tacky material that can be adhered without removing the oil.

  As such an adhesive material, for example, the adhesive sheets or adhesive tapes described in Patent Documents 1 to 3 are known.

Patent No. 3615774 Patent No. 3968836 JP, 2007-197629, A

  The pressure-sensitive adhesive sheets or pressure-sensitive adhesive tapes described in Patent Documents 1 to 3 can absorb the oil on the surface of the adherend, but the adhesive strength to the adherend after oil absorption cannot be said to be sufficiently high. Therefore, the adhesive material attached to the surface of the adherend may be peeled off in the use process.

  An object of the present invention is to provide a pressure-sensitive adhesive sheet having excellent adhesiveness to the surface of an adherend on which oil is attached, and a laminate including the pressure-sensitive adhesive sheet.

  The present inventor has conducted extensive studies in order to solve the above problems. As a result, by using a (meth) acrylic copolymer composed of a monomer component of a specific composition and a pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing a tackifier having a high softening point. The inventors have found that excellent adhesiveness can be exhibited even on the surface of an adherend on which oil is adhered, and have completed the present invention.

That is, the present invention is
(A) Alkyl group having 1 to 18 carbon atoms (meth) acrylic acid alkyl ester 60 to 99.5% by weight,
(B) 0.5 to 12% by weight of a functional group-containing unsaturated monomer,
(C) Solid content of a (meth) acrylic copolymer obtained by copolymerizing a monomer component containing 0 to 39.5% by weight of an unsaturated monomer copolymerizable with (A) and (B). A pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing 100 parts by weight and 10 to 50 parts by weight of a tackifier having a softening point of higher than 115 ° C., and attached to an adherend surface to which oil is attached. And a pressure-sensitive adhesive sheet.

  In the (meth) acrylic acid alkyl ester (A), the content of the (meth) acrylic acid alkyl ester having an alkyl group having 7 to 18 carbon atoms is preferably 25% by weight or more, and 40% by weight or more. Is more preferable.

  The functional group of the functional group-containing unsaturated monomer (B) is preferably a carboxyl group and / or a hydroxyl group.

The degree of swelling after immersing the (meth) acrylic copolymer in a mineral oil-based rust preventive oil having a kinematic viscosity of ² to 10 mm ² / s for 2 hours is preferably 150% or more.

  The tackifier is preferably a rosin-based tackifying resin.

  Also, the present invention comprises an adherend having oil adhered to the surface thereof, and the pressure-sensitive adhesive sheet, wherein the surface of the adherend having oil adhered thereto has a pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. To the laminated body.

  It is preferable that the adherend is a metal steel plate having oil on its surface.

  The pressure-sensitive adhesive sheet of the present invention comprises a (meth) acrylic copolymer composed of a monomer component having a specific composition and a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing a tackifier having a high softening point, A high adhesive force can be exhibited even on the surface of an adherend to which oil is attached. Therefore, the oil content of the adherend contaminated with the oil content can be wiped off lightly, or the adhesive sheet can be directly attached without wiping off.

It is sectional drawing which shows typically the schematic structure of the adhesive sheet which concerns on this Embodiment. (A)-(d) It is sectional drawing which shows typically the schematic structure of the laminated body which concerns on this Embodiment.

1. Adhesive Sheet Hereinafter, an embodiment for forming the adhesive sheet of the present invention will be described.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention contains 100 parts by weight of the solid content of the (meth) acrylic copolymer and 10 to 50 parts by weight of the tackifier having a softening point of more than 115 ° C. as the solid content. It is formed from things. The (meth) alkyl means alkyl and / or methacryl, and (meth) in the present specification has the same meaning.

  The (meth) acrylic copolymer is (A) 60 to 99.5% by weight of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms, and (B) a functional group-containing unsaturated monomer. The monomer component contains 0.5 to 12% by weight, (C) 0 to 39.5% by weight of an unsaturated monomer copolymerizable with the above (A) and (B).

  Examples of the (meth) acrylic acid alkyl ester (A) include compounds represented by the following general formula (1).

（式中、Ｒ^１は、水素原子又はメチル基を、Ｒ^２は、炭素数１〜１８の直鎖又は分岐のアルキル基を示す。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear or branched alkyl group having 1 to 18 carbon atoms.)

Examples of R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a neopentyl group, an isoamyl group, a hexyl group, and a heptyl group. , Octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. Is mentioned.

  Specific examples of the (meth) acrylic acid alkyl ester (A) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic. Butyl acid, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, ( Hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, (meth) acrylic Isononyl acid, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) ac Undecyl acetate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, (meth) acrylic Examples thereof include alkyl (meth) acrylates (linear or branched alkyl having 1 to 18 carbon atoms) such as acid octadecyl.

  The mixing ratio of the (meth) acrylic acid alkyl ester (A) is 60 to 99.5% by weight, and preferably 70 to 99% by weight, based on all the monomer components.

  Among the (meth) acrylic acid alkyl ester (A), the (A1) alkyl group has a carbon number of 1 to 6 (meth) acrylic acid alkyl ester and the (A2) alkyl group has a carbon number of 7 to 18 (meth). ) It is preferable to use in combination with alkyl acrylate. The carbon number of the (meth) acrylic acid alkyl ester (A1) is more preferably 1 to 4, and the carbon number of the (meth) acrylic acid alkyl ester (A2) is more preferably 7 to 12. .

  When the (meth) acrylic acid alkyl ester (A1) and (A2) are used in combination, the mixing ratio of the (meth) acrylic acid alkyl ester (A2) is 25% by weight or more in the (meth) acrylic acid alkyl ester (A). Is preferable, and more preferably 40% by weight or more. That is, the ratio (weight basis) of (A1) / (A2) is preferably 0/100 to 75/25, more preferably 0/100 to 60/40, and 10/90 to 40 /. More preferably, it is 60. The higher the blending ratio of the (meth) acrylic acid alkyl ester (A2), the quicker it is possible to absorb the oil on the adherend, so that high adhesiveness can be obtained quickly after attachment. Further, by using the (meth) acrylic acid alkyl ester (A1) in combination, oil absorption and cohesive force can be balanced.

  Methyl acrylate and butyl acrylate can be preferably used as the (meth) acrylic acid alkyl ester (A1), and 2-ethylhexyl acrylate can be preferably used as the (meth) acrylic acid alkyl ester (A2). You can

  The functional group-containing unsaturated monomer (B) has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and has a reactive functional group other than that. The monomer which it has can be mentioned. Further, a monomer containing a group having an unsaturated double bond in a reactive functional group such as a maleimide group or an itacone imide group can also be used. However, a silicon-containing group such as an alkoxysilyl group is not included in the reactive functional group in the present invention. Specifically, a carboxyl group-containing unsaturated monomer, a hydroxyl group-containing unsaturated monomer, an amide group-containing unsaturated monomer, an amino group-containing unsaturated monomer, a glycidyl group-containing unsaturated monomer, cyano Group-containing unsaturated monomers, maleimide group-containing monomers, itacone imide group-containing monomers, succinimide group-containing monomers, sulfonic acid group-containing unsaturated monomers, phosphoric acid group-containing unsaturated monomers, etc. Can be mentioned. Among these, a carboxyl group-containing unsaturated monomer is preferable because it has a high adhesive force to a polar adherend such as a metal.

  More specifically, for example, as the carboxyl group-containing unsaturated monomer, an unsaturated carboxylic acid such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, croton, cinnamic acid, for example, itaconic acid. Monomethyl, monobutyl itaconic acid, unsaturated dicarboxylic acid monoesters such as 2-acryloyloxyethyl phthalic acid, for example, 2-methacryloyloxyethyl trimellitic acid, unsaturated tricarboxylic acid monoesters such as 2-methacryloyloxyethyl pyromellitic acid, For example, carboxyethyl acrylate (β-carboxyethyl acrylate, etc.), carboxyalkyl acrylate such as carboxypentyl acrylate, acrylic acid dimer (trade name: Aronix M-5600, manufactured by Toagosei Chemical Industry Co., Ltd.), acrylic acid trimer, In example, itaconic anhydride, maleic anhydride, and unsaturated dicarboxylic acid anhydrides such as fumaric acid.

  Further, as the hydroxyl group-containing unsaturated monomer, for example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, etc., as the amide group-containing unsaturated monomer, for example, ( (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N Examples of amino group-containing unsaturated monomers such as -methylol (meth) acrylamide and N-methylolpropane (meth) acrylamide include aminoethyl (meth) acrylate and N, N-dimethylaminoethyl (meth) acrylate. , T-butylaminoethyl (meth) acrylate, etc., glycidyl group-containing unsaturated monomer As, for example, (meth) glycidyl acrylate, (meth) methyl glycidyl acrylate, as a cyano group-containing unsaturated monomer, for example, (meth) acrylonitrile, as a maleimide group-containing monomer, for example, , N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like, as the itacone imide group-containing monomer, for example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide. , N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide and the like, examples of the succinimide group-containing monomer include N- (meth) acryloyloxymethylenesuccinimide, N -(Meta) Examples of the unsaturated monomer containing a sulfonic acid group such as liloyl-6-oxyhexamethylenesuccinimide and N- (meth) acryloyl-8-oxyoctamethylenesuccinimide include styrenesulfonic acid, allylsulfonic acid, and 2- (meth ) Acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalenesulfonic acid, etc. -Hydroxyethyl acryloyl phosphate and the like can be mentioned. Further, functional monomers such as 2-methacryloyloxyethyl isocyanate, polyester acrylate, urethane acrylate and the like can also be mentioned.

  As the functional group-containing unsaturated monomer (B), the above-mentioned ones may be used alone or in combination of two or more. The mixing ratio of the functional group-containing unsaturated monomer (B) is 0.5 to 12% by weight, preferably 1 to 10% by weight, based on all the monomer components.

  The unsaturated monomer (C) is other than the (meth) acrylic acid alkyl ester (A) and the functional group-containing unsaturated monomer (B), and these (A), ( There is no particular limitation as long as it is copolymerizable with B). Specifically, for example, vinyl ester group-containing monomers such as vinyl acetate, for example, aromatic unsaturated monomers such as styrene and vinyltoluene, for example, (meth) acrylates such as cyclopentyl di (meth) acrylate and isobornyl (meth) acrylate. Acrylic acid cycloalkyl ester monomers such as N-vinylpyrrolidone, N- (1-methylvinyl) pyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N- Vinyl group-containing heterocyclic compounds such as vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, and (meth) acryloylmorpholine, for example, methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate. Containing alkoxy groups Unsaturated monomers, for example, olefinic monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene, for example, vinyl ether-based monomers such as vinyl ether, for example, halogen atom-containing unsaturated monomers such as vinyl chloride, and others, for example, (meth) Examples thereof include tetrahydrofurfuryl acrylate, a heterocycle such as fluorine (meth) acrylate, and an acrylate monomer containing a halogen atom.

  Further, the unsaturated monomer (C) may be a polyfunctional monomer. Here, the polyfunctional monomer refers to a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetraethylene glycol di (meth) acrylate. Such as (mono or poly) ethylene glycol di (meth) acrylate, or (mono or poly) propylene glycol di (meth) acrylate such as (mono or poly) alkylene glycol di (meth) acrylate Besides acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Examples thereof include tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and divinylbenzene.

  Furthermore, examples of the unsaturated monomer (C) include an alkoxysilyl group-containing vinyl monomer. Examples of the alkoxysilyl group-containing vinyl monomer include silicone (meth) acrylate monomers and silicone vinyl monomers.

  Examples of the silicone-based (meth) acrylate monomer include (meth) acryloyloxymethyl-trimethoxysilane, (meth) acryloyloxymethyl-triethoxysilane, 2- (meth) acryloyloxyethyl-trimethoxysilane, and 2- ( (Meth) acryloyloxyethyl-triethoxysilane, 3- (meth) acryloyloxypropyl-trimethoxysilane, 3- (meth) acryloyloxypropyl-triethoxysilane, 3- (meth) acryloyloxypropyl-tripropoxysilane, 3 (Meth) acryloyloxypropyl-triisopropoxysilane, (meth) acryloyloxypropyl-tributoxysilane and other (meth) acryloyloxyalkyl-trialkoxysilanes, for example, (meth) acryloyloxymethyl-methyl Dimethoxysilane, (meth) acryloyloxymethyl-methyldiethoxysilane, 2- (meth) acryloyloxyethyl-methyldimethoxysilane, 2- (meth) acryloyloxyethyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl -Methyldimethoxysilane, 3- (meth) acryloyloxypropyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl-methyldipropoxysilane, 3- (meth) acryloyloxypropyl-methyldiisopropoxysilane, 3- (Meth) acryloyloxypropyl-methyldibutoxysilane, 3- (meth) acryloyloxypropyl-ethyldimethoxysilane, 3- (meth) acryloyloxypropyl-ethyldiethoxysilane, 3- (meth) acryloyloxypropyl Ethyldipropoxysilane, 3- (meth) acryloyloxypropyl-ethyldiisopropoxysilane, 3- (meth) acryloyloxypropyl-ethyldibutoxysilane, 3- (meth) acryloyloxypropyl-propyldimethoxysilane, 3- ( Examples thereof include (meth) acryloyloxyalkyl-alkyldialkoxysilanes such as (meth) acryloyloxypropyl-propyldiethoxysilane, and corresponding (meth) acryloyloxyalkyl-dialkyl (mono) alkoxysilanes.

  Examples of the silicone vinyl monomer include vinyltrialkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, and vinyltributoxysilane, and vinyls corresponding to these. Alkyldialkoxysilane and vinyldialkylalkoxysilane, for example, vinylmethyltrimethoxysilane, vinylmethyltriethoxysilane, β-vinylethyltrimethoxysilane, β-vinylethyltriethoxysilane, γ-vinylpropyltrimethoxysilane, γ. -Vinylalkyl such as vinylpropyltriethoxysilane, γ-vinylpropyltripropoxysilane, γ-vinylpropyltriisopropoxysilane and γ-vinylpropyltributoxysilane. Another trialkoxysilane, these correspond and (vinyl) alkyl dialkoxy silanes, and the like (vinyl alkyl) dialkyl (mono) alkoxysilanes.

  By using an alkoxysilyl group-containing vinyl monomer as the unsaturated monomer (C), an alkoxysilyl group is introduced into the polymer chain, and a cross-linking structure can be formed by a reaction between them, which is preferable.

  These unsaturated monomers (C) are appropriately used alone or in combination. The mixing ratio of the unsaturated monomer (C) is 0 to 39.5% by weight, and preferably 0 to 29% by weight, based on all the monomer components. When an alkoxysilyl group-containing vinyl monomer is used as the unsaturated monomer (C), its blending ratio is 0 to 39.5% by weight, and 0 to 10% by weight, based on all the monomer components. It is preferably 0 to 5% by weight, more preferably 0 to 1% by weight.

The swelling degree (oil absorption amount) of the (meth) acrylic copolymer used in the present invention is preferably 115% or more, more preferably 120% or more, further preferably 130% or more, It is particularly preferably 150% or more. The degree of swelling (oil absorption amount) can be measured by the method described in the examples of the present specification, and a kinematic viscosity of ² to 10 mm ² / s can be obtained by adding (meth) acrylic to a mineral oil-based rust preventive oil. It is defined as the degree of swelling after immersing the system copolymer for 2 hours. The higher the oil absorption amount, the faster the oil content on the surface of the adherend can be absorbed. Therefore, after the pressure-sensitive adhesive sheet is attached to the adherend on which the oil content adheres, high adhesiveness can be exhibited in a short time. When the degree of swelling (oil absorption) is less than the above range, the oil content adhering to the adherend cannot be completely removed, and a high adhesive force tends to be unable to be obtained.

  The oil absorption can be adjusted by, for example, the amount of copolymerization of the (meth) acrylic acid alkyl ester (A2) having an alkyl group having 7 to 18 carbon atoms.

  In order to prepare the (meth) acrylic copolymer of the present invention, the above-mentioned monomer components are polymerized by a known method such as solution polymerization, emulsion polymerization or bulk polymerization.

  In emulsion polymerization, for example, a polymerization initiator, an emulsifier, and, if necessary, a chain transfer agent, etc. are appropriately blended in water and polymerized together with the above-mentioned monomer components. More specifically, for example, a known emulsion polymerization method such as a batch charging method (batch polymerization method), a monomer dropping method, a monomer emulsion dropping method can be adopted. In the monomer dropping method, continuous dropping or divided dropping is appropriately selected. The reaction conditions and the like are appropriately selected, but the polymerization temperature is, for example, 20 to 100 ° C.

  The polymerization initiator is not particularly limited, and a polymerization initiator commonly used in emulsion polymerization is used. For example, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2, 2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2'-azobis (N, N Azo initiators such as'-dimethylene isobutylamidine) and 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, for example, persulfates such as potassium persulfate and ammonium persulfate Salt-based initiators such as benzoyl peroxide, t-butyl hydroperoxide, and peroxide-based initiators such as hydrogen peroxide, for example, substituted ethane-based compounds such as phenyl-substituted ethane. Initiator, for example, carbonyl-based initiators such as aromatic carbonyl compounds, for example, a combination of a persulfate and sodium hydrogen sulfite, and the like redox initiators such as a combination of a peroxide and sodium ascorbate.

  These polymerization initiators are appropriately used alone or in combination. The blending ratio of the polymerization initiator is appropriately selected, but is preferably 0.005 to 1 part by weight with respect to 100 parts by weight of all the monomer components.

  The emulsifier is not particularly limited, and an emulsifier usually used for emulsion polymerization is used. For example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkylphenyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene Examples thereof include anionic emulsifiers such as sodium alkylsulfosuccinate, and nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene polyoxypropylene block polymer.

  Further, radical-polymerizable (reactive) emulsifiers (for example, HS-10 (e.g., HS-10 (No. 10)) in which radical-polymerizable functional groups (reactive groups) such as propenyl groups and allyl ether groups are introduced into these anionic emulsifiers and nonionic emulsifiers. Ichikohyo Pharmaceutical Co., Ltd.)) and the like.

  These emulsifiers are appropriately used alone or in combination. Further, the mixing ratio of the emulsifier is preferably, for example, 0.2 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of all the monomer components.

  The chain transfer agent adjusts the molecular weight of the polymer, if necessary, and a chain transfer agent usually used for emulsion polymerization is used. Examples thereof include mercaptans such as 1-dodecanethiol, mercaptoacetic acid, 2-mercaptoethanol, 2-ethylhexyl thioglycolate, and 2,3-dimethylcapto-1-propanol. These chain transfer agents are appropriately used alone or in combination. Further, the blending ratio of the chain transfer agent is preferably, for example, 0.001 to 0.5 part by weight with respect to 100 parts by weight of all the monomer components.

  Further, when the (meth) acrylic copolymer is a water-dispersed (meth) acrylic copolymer, it is preferable to adjust the pH to 7 to 9 with ammonia water or the like from the viewpoint of stability. , PH 7-8 is more preferred.

  The pressure-sensitive adhesive composition used in the present invention contains 10 to 50 parts by weight of a tackifier having a softening point of higher than 115 ° C. based on 100 parts by weight of the solid content of the (meth) acrylic copolymer.

  As the tackifier, for example, one or two selected from various tackifier resins such as rosin-based resins, rosin-derivative resins, petroleum-based resins, terpene-based resins, phenol-based resins, ketone-based resins, acrylic oligomers, etc. The above can be used, and a rosin resin and a rosin derivative resin are particularly preferable.

  Since the tackifier used in the present invention has a high softening point of higher than 115 ° C, the adherend interface after supplying oil on the surface of the adherend can be strengthened. The softening point is preferably 120 ° C. or higher, more preferably 130 ° C. or higher, even more preferably 140 ° C. or higher, and particularly preferably 150 ° C. or higher.

  Examples of the tackifier having a softening point of higher than 115 ° C. include “Super Ester NS-120B (softening point: 120 ° C.)” and “Super Ester E-625 (softening point: 120 ° C.) manufactured by Arakawa Chemical Industry Co., Ltd. ) ”,“ Super Ester E-865NT (softening point: 160 ° C.) ”,“ Super Ester E-650NT (softening point: 160 ° C.) ”,“ Tamanor E-100 (softening point: 150 ° C.) ”,“ Tamanor E -200NT (softening point: 150 ° C) "," Pencel D-125 (softening point: 125 ° C) "," Pencel D-135 (softening point: 135 ° C) "," Pencel D-160 (softening point: 160 ° C) " ) ”,“ Hariester SK-508H (softening point: 130 ° C.) ”,“ Hariester SK-816E (softening point: 145 ° C.) ”manufactured by Harima Kasei Co., Ltd.,“ Hariester SK-822 ”. (Softening point: 170 ° C.) "," Hariester SK-323NS (softening point: 125 ° C.) "," Hariester AD-130 (softening point: 130 ° C.) "Although the like, but not limited to. Such tackifiers are appropriately used alone or in combination. By using a tackifier having a softening point of more than 115 ° C., when a pressure-sensitive adhesive sheet is attached to a surface contaminated with oil, the (meth) acrylic copolymer absorbs the oil and is adhered to and removed. Strengthens the body interface and obtains high adhesive strength.

  Further, a tackifier having a softening point of 115 ° C. or lower can be used together. Examples of such a tackifier include “Super Ester E-720 (softening point: 100 ° C.)”, “Super Ester NS-100H (softening point: 100 ° C.)” manufactured by Arakawa Chemical Industries, Ltd., “ Super Ester A-100 (softening point: 100 ° C.), Harima Chemicals Co., Ltd. “Hariester SK-90D-55 (softening point: 90 ° C.)”, “Hariester SK-218NS (softening point: 100 ° C.) ) ”,“ Hariester TF (softening point: 80 ° C.) ”,“ Hariester DS-90 (softening point: 90 ° C.) ”and the like, but are not limited thereto. Among tackifiers having a softening point of 115 ° C. or less, those which are liquid at room temperature are not preferable because the strength of the interface of the adherend is lowered even if the oil on the surface of the adherend is removed.

  Further, the acrylic oligomer is preferably a polymer containing a (meth) acrylate having a high glass transition temperature (Tg) as a constituent component and having a weight average molecular weight of 1,000 to 30,000. it can. The softening point of the acrylic oligomer can be appropriately set depending on the type of the monomer used, and may be 115 ° C. or lower even if it exceeds 115 ° C. In general, the softening point of an oligomer can be regarded as (glass transition temperature (° C) + 50 ° C of oligomer) ± 5 ° C (Takumi Okazaki, “Adhesion Technology” 20 (2), 13 (2000)). .

  Examples of the (meth) acrylate having a high Tg include dicyclopentanyl methacrylate (Tg of homopolymer: 175 ° C.), cyclohexyl methacrylate (Tg of homopolymer: 66 ° C.), isobornyl methacrylate (Tg of homopolymer). 173 ° C.), isobornyl acrylate (Tg of homopolymer: 97 ° C.), dicyclopentanyl acrylate (Tg of homopolymer: 120 ° C.), 1-adamantyl methacrylate (Tg of homopolymer: 250 ° C.), 1- Adamantyl acrylate (Tg of homopolymer: 153 ° C.), cyclohexyl acrylate (Tg of homopolymer: 15 ° C.), isobutyl methacrylate (Tg of homopolymer: 48 ° C.), methyl methacrylate (Tg of homopolymer: 105 ° C.), etc. Bets can be, they alone, or may be used in combination of two or more. Among these, a monomer having a homopolymer Tg of 0 ° C. or higher is preferable, a monomer having a homopolymer Tg of 50 ° C. or higher is more preferable, and a monomer having a homopolymer Tg of 100 ° C. or higher is further preferable. The weight average molecular weight of the acrylic oligomer is more preferably 1,500 to 20,000, further preferably 2,000 to 10,000.

  The “Tg of homopolymer” means the glass transition temperature of a homopolymer of the monomer, and the glass transition of a polymer formed by using only a certain monomer (sometimes referred to as “monomer X”) as a monomer component. It means temperature (Tg). Specifically, numerical values are given in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc, 1989). The glass transition temperature (Tg) of a homopolymer not described in the above literature refers to a value obtained by the following measuring method, for example.

(Method for measuring Tg of homopolymer)
In a reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube and a reflux cooling tube, 100 parts by weight of the monomer X, 0.2 parts by weight of 2,2'-azobisisobutyronitrile and 200 parts by weight of ethyl acetate as a polymerization solvent. And stirring for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature is raised to 63 ° C. and the reaction is carried out for 10 hours. Then, it is cooled to room temperature to obtain a homopolymer solution having a solid content concentration of 33% by weight. Next, this homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-shaped homopolymer) having a thickness of about 2 mm. About 1 to 2 mg of this test sample was weighed in an open cell made of aluminum, and using a temperature modulation DSC (trade name: Q-2000, manufactured by TA Instruments) under a nitrogen atmosphere of 50 mL / min. The Reversing Heat Flow (specific heat component) behavior of the homopolymer is obtained at a heating rate of 5 ° C./min. With reference to JIS-K-7121, the obtained Reversing Heat Flow has a straight line extending at the low temperature side and a high temperature side from the straight line that is equidistant to the vertical axis, and a stepwise change in the glass transition. The temperature at the point where the curve of the part intersects is defined as the glass transition temperature (Tg) when the homopolymer is used.

  The blending ratio of the tackifier having a softening point of higher than 115 ° C. is 10 to 50 parts by weight, and 12 to 45 parts by weight, based on the solid content of 100 parts by weight of the (meth) acrylic copolymer. Is preferable, and it is more preferable that it is 15 to 40 parts by weight. If the compounding ratio of the tackifier having a softening point of more than 115 ° C. is less than the above, a sufficiently high adhesive force may not be obtained after sticking to the adherend surface to which oil is adhered. Wearability tends to decrease.

  When a tackifier having a softening point of 115 ° C. or lower is used together, the total amount of the tackifier having a softening point of higher than 115 ° C. is 100 parts by weight of the solid content of the (meth) acrylic copolymer. On the other hand, it is preferably from 15 to 50 parts by weight, more preferably from 20 to 45 parts by weight, even more preferably from 25 to 40 parts by weight, based on the solid content.

  Further, the pressure-sensitive adhesive composition used in the present invention contains a polymer component other than the acrylic copolymer as an optional component in addition to the (meth) acrylic copolymer and the tackifier. You can As such a polymer component, a polymer having a property of rubber or elastomer is preferable, for example, ethylene-vinyl acetate copolymer, acrylic rubber, natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SBR), chloroprene rubber. (CR), butyl rubber (IIR), ethylene propylene rubber (EPM, EPDM), polyisobutylene, styrene-ethylene-butylene-styrene copolymer (SEBS), acrylonitrile-butadiene copolymer (NBR), styrene-butadiene-styrene. Examples thereof include block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), polyvinyl alkyl ethers (for example, polyvinyl isobutyl ether), and the like. One of these may be used alone, or two or more may be used in combination.

  It is appropriate that the blending ratio of the polymer component is usually 50 parts by weight or less (for example, 5 to 50 parts by weight) based on 100 parts by weight of the (meth) acrylic copolymer, based on the solid content. The blending ratio of such a polymer component may be 5 parts by weight or less, and the polymer component may not be substantially contained.

  Further, the pressure-sensitive adhesive composition used in the present invention may optionally contain a crosslinking agent depending on its purpose and use. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent. The cross-linking agent is not particularly limited, and an oil-soluble or water-soluble cross-linking agent is used. These cross-linking agents are appropriately used alone or in combination, and the mixing ratio thereof is preferably, for example, 10 parts by weight or less, and 0.1 to 10 parts by weight with respect to 100 parts by weight of all the monomer components. More preferably.

  Further, the pressure-sensitive adhesive includes a viscosity adjusting agent, and if necessary, a release adjusting agent, a plasticizer, a softening agent, a filler, a coloring agent (pigment, dye, etc.), an antiaging agent, a surfactant, a leveling agent, and a decoloring agent. Additives that are usually added to pressure-sensitive adhesives such as foaming agents may be added as appropriate. The mixing ratio of these additives is not particularly limited and can be appropriately selected.

  Further, the pressure-sensitive adhesive sheet of the present invention may include a base material in addition to the pressure-sensitive adhesive layer.

  Examples of the material for forming the base material include polyolefin films such as polyethylene, polypropylene and ethylene / propylene copolymers, polyester films such as polyethylene terephthalate, plastic films such as polyvinyl chloride, kraft paper and paper such as Japanese paper. Examples thereof include cloths such as cotton cloth, soft cloth, polyester non-woven cloth, woven cloth such as vinylon cloth and woven cloth, and metal foil.

  As the plastic films, both unstretched films and stretched (uniaxially stretched or biaxially stretched) films can be used. Further, the surface of the base material on which the pressure-sensitive adhesive layer is provided may be subjected to surface treatment such as application of an undercoat and corona discharge treatment.

  The pressure-sensitive adhesive layer can be obtained by applying the pressure-sensitive adhesive composition to a substrate using a known coating method and drying. To apply the pressure-sensitive adhesive composition to the substrate, it is not particularly limited, for example, gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, fountain die coater, closed. An edge die coater or the like is used.

  The thickness of the pressure-sensitive adhesive layer after drying is not particularly limited, but is preferably 500 μm or less, more preferably 5 to 200 μm, for example. Further, when a plurality of pressure-sensitive adhesive layers are present, the total thickness thereof may be within the above range. The drying temperature depends on the type of the base material, but is preferably 40 to 120 ° C, for example.

  The pressure-sensitive adhesive layer can also be transferred to a substrate after the pressure-sensitive adhesive composition is applied to a release sheet to form the pressure-sensitive adhesive layer.

  The pressure-sensitive adhesive sheet according to the present invention can have a cross-sectional structure schematically shown in FIGS. 1 (a) to 1 (c), for example.

  FIG. 1A shows an example of the constitution of a pressure-sensitive adhesive sheet with a base material of a single-sided pressure-sensitive adhesive type, and a pressure-sensitive adhesive layer 2 is provided on one surface of the base material 1. Such a pressure-sensitive adhesive sheet has, for example, a pressure-sensitive adhesive layer 2 as shown in FIG. 1A, with the surface of the base material 1 opposite to the surface on which the pressure-sensitive adhesive layer 2 is formed as a release surface. It can be formed in a roll shape by winding so that the peeled surface of the laminated base material 1 comes into contact with the pressure-sensitive adhesive layer 2 laminated on the base material 1.

  In the pressure-sensitive adhesive sheet shown in FIG. 1 (b), the pressure-sensitive adhesive layer 2 has a structure in which at least the pressure-sensitive adhesive layer side is a release surface, and the release sheet 3 protects the roll-shaped roll. It can also be formed.

  In the pressure-sensitive adhesive sheet shown in FIG. 1 (c), a pressure-sensitive adhesive layer 2 is provided on both surfaces of a substrate 1, and both of these pressure-sensitive adhesive layers 2 have a release surface on at least the pressure-sensitive adhesive layer side. Each has a structure protected by. The pressure-sensitive adhesive sheet shown in FIG. 1 (c) is, for example, formed by forming the pressure-sensitive adhesive layer 2 on the release sheet 3 in advance, applying the pressure-sensitive adhesive layer 2 to the front and back surfaces of the base material 1, and winding the roll to form a roll shape. Can be formed.

  In addition, in the pressure-sensitive adhesive sheet shown in FIG. 1C, the pressure-sensitive adhesive layers 2 are provided on both sides of the base material 1, but these pressure-sensitive adhesive layers 2 may be formed of pressure-sensitive adhesives having the same composition, or different. You may form with the adhesive of each composition.

2. Laminated Body Next, an embodiment for forming the laminated body of the present invention will be described.

  The layered product of the present invention comprises an adherend having oil adhering to the surface (referred to as a first adherend), and the pressure-sensitive adhesive sheet, and the surface of the adherend having oil adhering thereto. In addition, the adhesive layer of the adhesive sheet is attached. Further, if necessary, a second adherend can be provided on the side of the pressure-sensitive adhesive sheet opposite to the side on which the first adherend is attached.

  Materials for forming the first and second adherends include high-quality paper, vapor-deposited paper, polyethylene laminated paper, kraft paper, Japanese paper and other papers, polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride and other plastics. Examples thereof include films, foams such as urethane, polyester and butyl rubber, plastic plates such as polyethylene, polypropylene and acrylic, decorative plates, metal steel plates such as iron, copper and stainless steel. Oil is attached to the surface of the first adherend. Oil may be attached to the surface of the second adherend.

  The oil adhering to the surface of the adherend is not particularly limited, and includes rust preventive oil, processing oil, press oil, cutting oil, engine oil, gear oil, mineral oil such as grease, rapeseed oil, olive oil, canola oil, palm oil, etc. Examples include vegetable oils, animal oils such as lard and beef tallow, and sebum.

  The laminate according to the present invention can have, for example, a cross-sectional structure schematically shown in FIGS. 2 (a) to 2 (d).

  2 (a) and 2 (b) are examples of the laminated body configuration in the case where oil is not attached to the surface of the second adherend 5, and the adhesive sheet 7 of FIG. 2 (a) does not include a base material. The adhesive sheet 7 in FIG. 2B includes the base material 8. 2 (c) and 2 (d) are examples of a laminated body configuration in which oil is also attached to the surface of the second adherend 5, and the adhesive sheet 7 in FIG. 2 (c) includes a base material. The adhesive sheet 7 in FIG. 2 (d) includes the base material 8.

  2A to 2D, the laminated body has the second adherend 5, but the base material forming the pressure-sensitive adhesive sheet is the outermost layer in place of the second adherend 5. It may be a laminated body. Further, in the case of FIG. 2B, the adhesive layer has a plurality of layers, but the adhesive layer on the side in contact with the first adherend 5 may be the adhesive layer used in the present invention, and the second adherend may be used. The adhesive layer on the side in contact with the body 5 (or the substrate) may be the adhesive layer of the present invention, and a conventionally known layer made of an adhesive can be used without particular limitation.

  The pressure-sensitive adhesive sheet of the present invention can be lightly wiped off the oil content on the surface of the adherend to which the oil content is attached, or can be attached without wiping it off to form a laminate.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples and comparative examples. In the following description, "part" and "%" are based on weight unless otherwise specified.

Synthesis example 1 (synthesis of water-dispersed (meth) acrylic copolymer (A))
2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (polymerization initiator) was added to a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer (commercial product). Name: VA-057, manufactured by Wako Pure Chemical Industries, Ltd. 0.1 part and ion-exchanged water 50 parts were charged and stirred for 1 hour while introducing nitrogen gas. This was kept at 60 ° C., and 87 parts of 2-ethylhexyl acrylate, 13 parts of methyl acrylate, 1.25 parts of acrylic acid (AA), 0.75 part of methacrylic acid (MAA), 3-methacryloyloxypropyltrimethoxysilane ( Trade name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd., 0.02 part, t-dodecanethiol (chain transfer agent) 0.048 part, and polyoxyethylene sodium lauryl sulfate (emulsifier) 2 parts, and ion-exchanged water 35 What was added to a part and emulsified (namely, emulsion of a monomer raw material) was dripped over 3 hours, and after completion of the dropping, polymerization was continued at the same temperature for 3 hours. The liquid property was adjusted to pH 7.5 by adding 10% ammonium water to this, and the water dispersion type (meth) acrylic-type copolymer (A) was obtained.

Synthesis example 2 (synthesis of water-dispersed (meth) acrylic copolymer (B))
2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (polymerization initiator) was added to a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer (commercial product). Name: VA-057, manufactured by Wako Pure Chemical Industries, Ltd. 0.1 part and ion-exchanged water 50 parts were charged and stirred for 1 hour while introducing nitrogen gas. This is kept at 60 ° C., and 70 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, 3 parts of acrylic acid (AA), 3-methacryloyloxypropyltrimethoxysilane (trade name: KBM-503, Shin-Etsu Chemical Co., Ltd. )) 0.03 parts, dodecanethiol (chain transfer agent) 0.05 parts and sodium polyoxyethylene lauryl sulfate (emulsifier) 2 parts were added to 35 parts of ion-exchanged water and emulsified (that is, as a monomer raw material). (Emulsion) was added dropwise over 3 hours, and after completion of the addition, polymerization was continued for another 3 hours at the same temperature. To this, 10% ammonium water was added to adjust the liquidity to pH 7.5 to obtain a water dispersion type (meth) acrylic copolymer (B).

Synthesis example 3 (synthesis of water-dispersed (meth) acrylic copolymer (C))
2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (polymerization initiator) was added to a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer (commercial initiator). Name: VA-057, manufactured by Wako Pure Chemical Industries, Ltd. 0.1 part and ion-exchanged water 50 parts were charged and stirred for 1 hour while introducing nitrogen gas. This was kept at 60 ° C., where 90 parts of butyl acrylate, 10 parts of 2-ethylhexyl acrylate, 4 parts of acrylic acid (AA), 3-methacryloyloxypropyltrimethoxysilane (trade name: KBM-503, Shin-Etsu Chemical Co., Ltd. )) 0.07 part, dodecanethiol (chain transfer agent) 0.05 part, and polyoxyethylene lauryl sulfate sodium (emulsifier) 2 parts were added to 35 parts of ion-exchanged water and emulsified (that is, as a monomer raw material). (Emulsion) was added dropwise over 3 hours, and after completion of the addition, polymerization was continued for another 3 hours at the same temperature. To this, 10% ammonium water was added to adjust the liquidity to pH 7.5 to obtain a water dispersion type (meth) acrylic copolymer (C).

Synthesis Example 4 (Synthesis of (meth) acrylic copolymer solution (D))
In a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer, 100 parts of butyl acrylate (BA), 5 parts of acrylic acid (AA), 0.2 parts of BPO (benzoyl peroxide) (polymerization initiator), 150 parts of toluene was added, and the mixture was stirred for 1 hour while introducing nitrogen gas. Then, it superposed | polymerized at 63 degreeC for 7 hours, and obtained the acrylic-type copolymer solution (D).

Synthesis Example 5 (Synthesis of (meth) acrylic copolymer solution (E))
In a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer, 100 parts of butyl acrylate (BA), 5 parts of vinyl acetate, 0.1 part of hydroxyethyl acrylate (HEA), 3 parts of acrylic acid (AA), AIBN (2,2′-azobisisobutyronitrile) (polymerization initiator) (0.2 part) and toluene (150 parts) were added, and the mixture was stirred for 1 hour while introducing nitrogen gas. Then, it superposed | polymerized at 63 degreeC for 7 hours, and obtained the acrylic-type copolymer solution (E).

Synthesis Example 6 (Synthesis of (meth) acrylic copolymer solution (F))
70 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, 3 parts of acrylic acid (AA), 0.05 parts of 4-hydroxybutyl acrylate (4HBA) were placed in a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer. , AIBN (2,2′-azobisisobutyronitrile) (polymerization initiator), and 150 parts of toluene were added, and the mixture was stirred for 1 hour while introducing nitrogen gas. Then, it superposed | polymerized at 63 degreeC for 7 hours, and obtained the acrylic-type copolymer solution (F).

Synthesis Example 7 (Synthesis of (meth) acrylic copolymer solution (G))
In a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer, 100 parts of 2-ethylhexyl acrylate, 2 parts of acrylic acid (AA), 0.01 part of trimethylolpropane triacrylate (TMPTA), BPO (peroxidation). 0.2 part of benzoyl) (polymerization initiator) and 150 parts of toluene were added, and the mixture was stirred for 1 hour while introducing nitrogen gas. Then, it superposed | polymerized at 63 degreeC for 7 hours, and obtained the acrylic-type copolymer solution (G).

Example 1
A tackifier (trade name: super ester E-865NT, polymerized rosin ester, softening point: 160 ° C.) was added to 100 parts of the solid content of the water-dispersible (meth) acrylic copolymer (A) of Synthesis Example 1. Arakawa Chemical Industry Co., Ltd.) was mixed with 30 parts by solid content to prepare a water-dispersed pressure-sensitive adhesive composition.

  Subsequently, 0.7 part of a thickener (trade name: Aron B-500, manufactured by Toagosei Co., Ltd.) was added to 100 parts of the solid content of the prepared water-dispersed pressure-sensitive adhesive composition, and water was added. Thickening the dispersion-type pressure-sensitive adhesive composition, coating the thickened water-dispersion-type pressure-sensitive adhesive composition on a release sheet so that the thickness after drying is 60 μm, and drying this at 100 ° C. for 3 minutes. In this way, an adhesive sheet was produced. Further, another exactly the same pressure-sensitive adhesive sheet was produced by the same method.

  Each pressure-sensitive adhesive sheet was attached to both sides of a non-woven fabric substrate (trade name: SP base paper-14, manufactured by Daifuku Paper Co., Ltd.) to prepare a double-sided pressure-sensitive adhesive sheet.

Example 2
As the tackifier of Example 1, 20 parts of KE-802 (trade name, polymerized rosin ester, softening point: 170 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) in solid content, Super Ester NS-100H (trade name, A water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the rosin ester, softening point: 100 ° C., manufactured by Arakawa Chemical Industry Co., Ltd. was changed to 10 parts in terms of solid content. A double-sided PSA sheet was prepared.

Example 3
The tackifier of Example 1 was the same as Example 1 except that Tamanor E-200NT (trade name, rosin phenol, softening point: 150 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) was changed to 30 parts by solid content. A water-dispersed PSA composition was prepared in the same manner, and then a double-sided PSA sheet was produced.

Example 4
The tackifier of Example 1 was changed to Super Ester E-625NT (trade name, polymerized rosin ester, softening point: 120 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) with a solid content of 30 parts except that the tackifier was changed to 30 parts. A water-dispersed PSA composition was prepared in the same manner as in 1, and subsequently a PSA sheet was prepared.

Example 5
The tackifier of Example 1 was the same as Example 1 except that Super Ester NS-120B (trade name, rosin ester, softening point: 120 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) was changed to 30 parts by solid content. A water-dispersed PSA composition was prepared in the same manner, and subsequently a PSA sheet was prepared.

Example 6
Pencel D-160 (trade name, polymerized rosin ester, softening point: 160 ° C., Arakawa Chemical Co., Ltd.) was used as a tackifier to 100 parts of the solid content of the (meth) acrylic copolymer solution (G) of Synthesis Example 7. 30 parts of Kogyo Co., Ltd. was mixed, and further 0.05 parts of an epoxy-based cross-linking agent (trade name: TETRAD-C, Mitsubishi Gas Chemical Co., Inc.) was mixed to prepare an adhesive composition solution. .

  The prepared pressure-sensitive adhesive composition solution was coated on a release sheet so that the thickness after drying was 60 μm, and this was dried at 100 ° C. for 3 minutes to prepare a pressure-sensitive adhesive sheet. Further, another exactly the same pressure-sensitive adhesive sheet was produced by the same method.

  Each pressure-sensitive adhesive sheet was attached to both sides of a non-woven fabric substrate (trade name: SP base paper-14, manufactured by Daifuku Paper Co., Ltd.) to prepare a double-sided pressure-sensitive adhesive sheet.

Example 7
In the preparation of the water-dispersed pressure-sensitive adhesive composition of Example 1, the water-dispersed (meth) acrylic copolymer (A) of Synthesis Example 1 was replaced with the water-dispersed (meth) acrylic copolymer of Synthesis Example 2. The same method as in Example 1 except that (B) was used and the tackifier was changed to Tamanor E-200NT (trade name, rosin phenol, softening point: 150 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.). To prepare a water-dispersed pressure-sensitive adhesive composition, and subsequently to produce a pressure-sensitive adhesive sheet.

Example 8
Pencel D-125 (trade name, polymerized rosin ester, softening point: 125 ° C., Arakawa Chemical Industry Co., Ltd. as a tackifier, based on 100 parts of solid content of the (meth) acrylic copolymer solution (F) of Synthesis Example 6 (Manufactured by K.K.) and 30 parts by weight of an isocyanate crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) were mixed to prepare a pressure-sensitive adhesive composition solution.

  The prepared pressure-sensitive adhesive composition solution was coated on a release sheet so that the thickness after drying was 60 μm, and this was dried at 100 ° C. for 3 minutes to prepare a pressure-sensitive adhesive sheet. Further, another exactly the same pressure-sensitive adhesive sheet was produced by the same method.

  Each pressure-sensitive adhesive sheet was attached to both sides of a non-woven fabric substrate (trade name: SP base paper-14, manufactured by Daifuku Paper Co., Ltd.) to prepare a double-sided pressure-sensitive adhesive sheet.

Example 9
In the preparation of the water-dispersed pressure-sensitive adhesive composition of Example 1, the water-dispersed (meth) acrylic copolymer (A) of Synthesis Example 1 was replaced with the water-dispersed (meth) acrylic copolymer of Synthesis Example 3. The same method as in Example 1 except that (C) was used and the tackifier was Tamanor E-200NT (trade name, rosin phenol, softening point: 150 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.). To prepare a water-dispersed pressure-sensitive adhesive composition, and subsequently to produce a pressure-sensitive adhesive sheet.

Comparative Example 1
In the preparation of the water-dispersed pressure-sensitive adhesive composition of Example 1, no tackifier (trade name: super ester E-865NT, polymerized rosin ester, softening point: 160 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) was added. A water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive sheet was subsequently prepared.

Comparative example 2
In the preparation of the water-dispersed pressure-sensitive adhesive composition of Example 7, a tackifier (trade name: Tamanor E-200NT, rosin phenol, softening point: 150 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) was not added. A water-dispersed PSA composition was prepared in the same manner as in Example 7, and subsequently a PSA sheet was prepared.

Comparative Example 3
In the preparation of the water-dispersed PSA composition of Example 9, except that no tackifier (trade name: Tamanol E-200NT, rosin phenol, softening point: 150 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) was added. In the same manner as in Example 9, a water-dispersed pressure-sensitive adhesive composition was prepared, and subsequently a pressure-sensitive adhesive sheet was produced.

Comparative Example 4
The tackifier of Example 1 was changed to Super Ester NS-100H (trade name, rosin phenol, softening point: 100 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) at 30 parts in solid content, except that the tackifier was changed to 30 parts. A water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in 1. and subsequently, a pressure-sensitive adhesive sheet was produced.

Comparative Example 5
Except that the tackifier of Example 1 was changed to 30 parts in terms of solid content, Knit Resin Kumaron WS-100G (trade name, coumarone resin, softening point: 100 ° C., manufactured by Nikkei Chemical Co., Ltd.) was changed to 30 parts. A water-dispersed PSA composition was prepared in the same manner as in 1, and subsequently a PSA sheet was prepared.

Comparative Example 6
The same as in Example 1 except that the tackifier of Example 1 was changed to 30 parts by weight of Nanolet R-1050 (trade name, terpene resin, softening point: 105 ° C, Yasuhara Chemical Co., Ltd.) in terms of solid content. A water-dispersed PSA composition was prepared by the method, and then a PSA sheet was prepared.

Comparative Example 7
As the tackifier of Example 1, the same as in Example 1 except that Hariestar SN501NS (trade name, rosin resin, balsam (liquid), manufactured by Harima Kasei Co., Ltd.) was changed to 30 parts in terms of solid content. A water-dispersed pressure-sensitive adhesive composition was prepared by the method of 1 above, and then a pressure-sensitive adhesive sheet was prepared.

Comparative Example 8
Tackifier of Example 3 (trade name: Tamanor E-200NT, rosin phenol, softening point: 150 ° C, manufactured by Arakawa Chemical Industry Co., Ltd.), except that the solid content was changed from 30 parts to 10 parts. A water-dispersed PSA composition was prepared in the same manner as in Example 3, and subsequently a PSA sheet was prepared.

Comparative Example 9
To 100 parts of the solid content of the (meth) acrylic copolymer solution (D) of Synthesis Example 4, 2 parts of a solid content of a crosslinking agent (product: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) was blended. A pressure-sensitive adhesive composition solution was prepared.

  Subsequently, the prepared pressure-sensitive adhesive composition solution was coated on a release sheet so that the thickness after drying was 60 μm, and this was dried at 100 ° C. for 3 minutes to prepare a pressure-sensitive adhesive sheet. Further, another exactly the same pressure-sensitive adhesive sheet was produced by the same method.

  Each pressure-sensitive adhesive sheet was attached to both sides of a non-woven fabric substrate (trade name: SP base paper-14, manufactured by Daifuku Paper Co., Ltd.) to prepare a double-sided pressure-sensitive adhesive sheet.

Comparative Example 10
In the preparation of the pressure-sensitive adhesive composition solution of Comparative Example 9, the (meth) acrylic copolymer solution (D) of Synthesis Example 4 was changed to the (meth) acrylic copolymer solution (E) of Synthesis Example 5. A double-sided pressure-sensitive adhesive sheet was produced in the same manner as in Comparative Example 9 except for the above.

Comparative Example 11
In the preparation of the pressure-sensitive adhesive composition solution of Comparative Example 9, the (meth) acrylic copolymer solution (D) of Synthesis Example 4 was changed to the (meth) acrylic copolymer solution (F) of Synthesis Example 6. A double-sided pressure-sensitive adhesive sheet was produced in the same manner as in Comparative Example 9 except for the above.

Comparative Example 12
In the preparation of the pressure-sensitive adhesive composition solution of Comparative Example 9, the (meth) acrylic copolymer solution (D) of Synthesis Example 4 was changed to the (meth) acrylic copolymer solution (G) of Synthesis Example 7. A double-sided pressure-sensitive adhesive sheet was produced in the same manner as in Comparative Example 9 except for the above.

<Evaluation>
The evaluation was performed by the following evaluation method.

(1) Swelling degree (oil absorption)
The water-dispersed pressure-sensitive adhesive composition or pressure-sensitive adhesive composition solution obtained in each of the examples and each of the comparative examples was peeled off with a release sheet (trade name: Diamond foil MRF-38, Mitsubishi resin) so that the thickness after drying was 150 μm. Co., Ltd.) and dried at 100 ° C. for 3 minutes to prepare an adhesive sheet. The release sheet of the obtained pressure-sensitive adhesive sheet was peeled off, five sheets were laminated, and then cut into a size of 20 × 20 mm as an evaluation sample, and the weight Wa (g) was measured.

Into an aluminum cup, 1.5 g of rust preventive oil (trade name: Preton R-303PX2, liquid kinematic viscosity: 5.0 mm ² / s, manufactured by Sugimura Chemical Co., Ltd.) was weighed, and the evaluation sample was immersed therein. Two hours after the immersion, excess oil was wiped off, and the weight Wb (g) of the evaluation sample was measured. The degree of swelling (oil absorption) after immersion in oil was calculated based on the following formula.

        Swelling degree (oil absorption) (%) = (Wb-Wa) / Wa × 100

(2) SUS adhesive strength One release sheet of the pressure-sensitive adhesive sheet obtained in each Example and each Comparative Example was peeled off, and a polyethylene terephthalate substrate having a thickness of 25 μm (trade name: Lumirror S-10, manufactured by Toray Industries, Inc.) was used. Pasted together. This was cut into a size of 20 × 100 mm and used as an evaluation sample. This was attached to a SUS304BA plate as an adherend at 25 ° C., and a 2 kg roller was reciprocated once for pressure bonding. Then, it was left at 25 ° C. for 30 minutes, a peeling test was carried out at a peeling angle of 180 ° and a peeling speed of 300 mm / min, and the adhesive force (unit: N / 20 mm) was measured.

(3) Oil surface adhesive strength One release sheet of the pressure-sensitive adhesive sheet obtained in each Example and each Comparative Example was peeled off, and a polyethylene terephthalate substrate (trade name: Lumirror S-10, manufactured by Toray Industries, Inc.) having a thickness of 25 μm was peeled off. Pasted together. This was cut into a size of 20 × 100 mm and used as an evaluation sample.

The evaluation sample was attached to a SUS304BA plate uniformly coated with 5 g / m ² of rust preventive oil (trade name: Preton R-303PX2, manufactured by Sugimura Chemical Co., Ltd.), and a 2 kg roller was reciprocated once to make a pressure bond. Then, it was left at 25 ° C. for 30 minutes, 2 hours, and 24 hours, and a peeling test was performed at a peeling angle of 180 ° and a peeling speed of 300 mm / min to measure the adhesive force (unit: N / 20 mm).

  It can be seen that the pressure-sensitive adhesive sheet according to the present invention exhibits excellent adhesiveness to the surface of the adherend on which oil is attached.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

  The pressure-sensitive adhesive sheet of the present invention can exhibit high pressure-sensitive adhesive force to the surface of an adherend on which oil is adhered, and thus can be suitably used in a wide range of industrial fields such as automobiles, home appliances, and building materials.

DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive layer 3 Release sheet 4 1st adherend 5 2nd adherend 6 Oil component 7 Adhesive sheet 8 Base material

Claims (7)

(A) Alkyl group having 1 to 18 carbon atoms (meth) acrylic acid alkyl ester 60 to 99.5% by weight,
(B) 0.5 to 12% by weight of a functional group-containing unsaturated monomer having a carboxyl group and / or a hydroxyl group,
(C) 0 to 39.5% by weight of an unsaturated monomer copolymerizable with the above (A) and (B)
100 parts by weight of solid content of a water dispersion type (meth) acrylic copolymer obtained by copolymerizing a monomer component containing
12 to 50 parts by weight of a tackifier having a softening point of more than 115 ° C.,
The tackifier is a rosin resin and / or a rosin derivative resin,
Including a pressure-sensitive adhesive layer formed from a water-dispersed pressure-sensitive adhesive composition containing
A pressure-sensitive adhesive sheet, which is applied to the surface of an adherend on which one or more kinds of oil components selected from mineral oil, vegetable oil, and animal oil are adhered.   The water-dispersed (meth) acrylic copolymer is a water-dispersed (meth) acrylic copolymer having a pH of 7 to 9, which is obtained by copolymerizing the monomer components in water. The pressure sensitive adhesive sheet according to claim 1.   The content of the (meth) acrylic acid alkyl ester having an alkyl group having 7 to 18 carbon atoms in the (meth) acrylic acid alkyl ester (A) is 25% by weight or more. The pressure-sensitive adhesive sheet according to 2.   The content of the (meth) acrylic acid alkyl ester having an alkyl group having 7 to 18 carbon atoms in the (meth) acrylic acid alkyl ester (A) is 40% by weight or more. The pressure-sensitive adhesive sheet according to any one of 3 above. The swelling degree after immersing the (meth) acrylic copolymer in a mineral oil-based rust preventive oil having a kinematic viscosity of ² to 10 mm ² / s for 2 hours is 150% or more. The pressure sensitive adhesive sheet according to any one of claims 1 to 4. An adherend to which the oil content is attached on the surface, and the pressure-sensitive adhesive sheet according to any one of claims 1 to 5 ,
A laminate, wherein the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is attached to the surface of the adherend on which the oil component is attached. The laminate according to claim 6 , wherein the adherend is a metal steel plate having the oil content adhered to the surface thereof.

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