TW201739862A - Adhesive sheet - Google Patents

Adhesive sheet Download PDF

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Publication number
TW201739862A
TW201739862A TW105141175A TW105141175A TW201739862A TW 201739862 A TW201739862 A TW 201739862A TW 105141175 A TW105141175 A TW 105141175A TW 105141175 A TW105141175 A TW 105141175A TW 201739862 A TW201739862 A TW 201739862A
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Taiwan
Prior art keywords
adhesive
adhesive sheet
weight
less
adhesive layer
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TW105141175A
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Chinese (zh)
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TWI719091B (en
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Yoshiko Kira
Kenta Jozuka
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Nitto Denko Corp
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/08—Homopolymers or copolymers of acrylic acid esters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/10—Homopolymers or copolymers of methacrylic acid esters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J193/00—Adhesives based on natural resins; Adhesives based on derivatives thereof
    • C09J193/04—Rosin
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/22—Plastics; Metallised plastics
    • C09J7/25—Plastics; Metallised plastics based on macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds
    • C09J7/255—Polyesters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/40—Adhesives in the form of films or foils characterised by release liners
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
    • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
    • C09J2301/122—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present only on one side of the carrier, e.g. single-sided adhesive tape
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
    • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
    • C09J2301/124—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
    • C09J2301/408—Additional features of adhesives in the form of films or foils characterized by the presence of essential components additives as essential feature of the adhesive layer

Abstract

Provided is an adhesive sheet which ensures less reduction in adhesiveness when coming into contact with oil components while leakage of adhesives is avoided. The adhesive sheet provided in the present invention includes an adhesive layer made of an adhesive containing an acrylic polymer as a base polymer. The surface free energy [gamma] of the adhesive layer is less than 40 mJ/m2, and infiltration rate of oleic acid per 1 g is greater than or equal to 1.5 g and less than or equal to 5.0 g.

Description

黏著片材Adhesive sheet

本發明係關於一種黏著片材。 本申請案係基於2016年1月28日提出申請之日本專利申請2016-014180而主張優先權，將其申請之全部內容作為參照併入本說明書中。The present invention relates to an adhesive sheet. Priority is claimed on Japanese Patent Application No. 2016-014180, filed Jan.

一般而言，黏著劑(亦稱為感壓接著劑。以下相同。)具有於室溫附近之溫度區域呈現柔軟之固體(黏彈性體)之狀態，藉由壓力而簡單地接著於被接著體之性質。活用此種性質，黏著劑例如以支持基材上具有黏著劑層之附基材之黏著片材之形態，以行動電話等其他行動裝置中之構件之接合或固定、保護等之目的而廣泛利用。作為關於用於可攜式電子機器之零件固定之雙面黏著帶的技術文獻，可列舉專利文獻1及2。 [先前技術文獻] [專利文獻] [專利文獻1]日本專利申請公開2009-215355號公報 [專利文獻2]日本專利申請公開2013-100485號公報In general, an adhesive (also referred to as a pressure-sensitive adhesive. The same applies hereinafter) has a state in which a soft solid (viscoelastic body) is present in a temperature region near room temperature, and is simply followed by a pressure by a pressure. Nature. In order to utilize such a property, the adhesive is widely used for the purpose of bonding or fixing, protecting, etc. of components in other mobile devices such as mobile phones, for example, in the form of an adhesive sheet supporting a substrate having an adhesive layer on a substrate. . Patent Documents 1 and 2 can be cited as technical documents relating to a double-sided adhesive tape for fixing a component of a portable electronic device. [Prior Art Document] [Patent Document 1] Japanese Patent Application Publication No. 2009-215355 (Patent Document 2) Japanese Patent Application Publication No. 2013-100485

[發明所欲解決之問題] 行動裝置可攜使用，因此容易附著皮脂或手垢等分泌物、化妝品或整發料、保濕乳霜、防曬霜等化學品、或者食品等所含之油分。尤其近年來顯著普及之觸控面板方式之行動裝置具備顯示部亦作為輸入部發揮功能之顯示部/輸入部，藉由使用者用指尖直接接觸該顯示部/輸入部之表面而操作，因此經由指尖而附著油分之機會較多。而且，所謂可佩戴設備之中，以接觸於皮膚之狀態穿著使用，於此種使用形態，暴露成塗抹於皮脂或皮膚之化學品等油分之機會較多。若於固定構件之黏著片材之黏著劑層接觸此種油分，則可能產生黏著力降低或黏著劑溢出等不良情況。 關於該方面，例如於專利文獻1中，對即便油分滲透，黏著劑亦難以軟化・膨潤，用於固定零件時黏著劑不溢出之雙面黏著片材進行研究。然而，於專利文獻1中，未考慮抑制起因於油分之接觸之黏著力降低。 本發明係鑒於該情況而成，其目的在於提供一種即便與油分接觸，黏著力之降低亦較少、且抑制黏著劑溢出之黏著片材。 [解決問題之技術手段] 根據本說明書，提供一種具備由以丙烯酸系聚合物作為基礎聚合物之黏著劑構成之黏著劑層的黏著片材。上述黏著劑層之表面自由能量γ未達40 mJ/m2 。而且，上述黏著劑層中，每1 g之油酸滲透量為1.5 g以上且5.0 g以下。 該構成之黏著片材由於黏著劑層之表面能量γ較低，故而有該黏著劑層對被接著體顯示良好之潤濕性之傾向。藉此，使黏著劑層與被接著體較佳密接，可抑制油分自黏著片材之外邊緣浸入至黏著劑層與被接著體之界面(接著界面)。而且，上述黏著劑層具有於下述油酸滲透量測定中，保持每1 g之1.5 g以上之油酸的能力。藉由顯示此種油分保持性，即便油分自黏著片材之外邊緣浸入至接著界面，該油分於黏著劑層之層內吸收(滲透)，可將接著界面保持為油分較少之狀態。如此，藉由設為抑制油分自黏著片材之外邊緣浸入至接著界面，且浸入之油分自接著界面容易吸收於黏著劑層之層內(塊體)之構成，可有效抑制因油分之接觸引起之黏著力降低。並且，藉由將黏著劑層每1 g之油酸滲透量限制為5.0 g以下，可防止黏著劑層過分吸收油分，黏著劑溢出之情況。 於較佳之一態樣之黏著片材中，上述黏著劑層之凝膠分率為30%以上且70%以下。藉由將凝膠分率設為上述範圍，有容易實現油酸滲透量在適當範圍之黏著劑層的傾向。 於較佳之其他一態樣中，上述黏著劑層係使用包含上述丙烯酸系聚合物及交聯劑之黏著劑組合物而形成。該態樣中存在可容易調整油酸滲透量(或進而凝膠分率)之優點。作為上述交聯劑，可較佳使用至少包含異氰酸酯系交聯劑之交聯劑。 此處所揭示之黏著片材可較佳以上述黏著劑層包含黏著賦予樹脂之態樣而實施。藉由於黏著劑層含有黏著賦予樹脂，可改善黏著劑層對被接著體之密接性，可更良好抑制油分自黏著片材之外邊緣浸入至接著界面。而且，藉由將上述黏著賦予樹脂之50重量%以上選自松香系黏著賦予樹脂以外之黏著賦予樹脂，有容易實現油酸滲透量及表面自由能量γ在適當範圍之黏著劑層之傾向。 於此處所揭示之黏著片材之一態樣中，構成上述丙烯酸系聚合物之單體成分包含多於50重量%之於酯末端具有碳原子數7以上且10以下(以下有時將此種碳原子數之範圍表記為「C7-10 」)之烷基的(甲基)丙烯酸烷基酯。若根據此處所揭示之技術，即便為如此以包含較多(甲基)丙烯酸C7-10 烷基酯之單體組成之丙烯酸系聚合物作為黏著劑層的基礎聚合物之構成，亦可實現較佳抑制起因於油分之黏著力降低及黏著劑溢出之黏著片材。 此處所揭示之黏著片材可較佳以構成上述丙烯酸系聚合物之單體成分包含多於5重量%之含羧基之單體之態樣而實施。若根據單體組成之丙烯酸系聚合物，可良好於黏著劑層之層內保持油酸等之油分。藉此，減少存在於接著界面之油分，可有效抑制因油分引起之黏著力降低。於包含較多(甲基)丙烯酸C7-10 烷基酯之單體組成之丙烯酸系聚合物中，使單體成分中之含羧基之單體之含量較多尤其有效。 此處所揭示之黏著片材可較佳以上述黏著劑層之厚度為25 μm以下之態樣而實施。如此黏著劑層之厚度相對較小之黏著片材中，該黏著片材之每單位面積之黏著劑量較少，因此將黏著劑層之油酸滲透量設為特定以上尤其有效。 較佳之一態樣之黏著片材構成為於基材之一個表面及另一表面具有上述黏著劑層之雙面黏著片材。雙面黏著片材係將黏著片材之一個表面及另一表面分別貼附於被接著體而使用，容易於與該等之被接著體之接著界面浸入油分。因此，應用此處所揭示之技術抑制起因於上述油分之黏著力降低特別有意義。 此處所揭示之黏著片材例如可較佳用於行動裝置中固定構件之用途。如上所述，行動裝置與油分接觸之機會較多，因此應用此處所揭示之技術而抑制因油分引起之黏著力降低及黏著劑之溢出特別有意義。[Problems to be Solved by the Invention] Since the mobile device can be used, it is easy to attach secretions such as sebum or hand scale, cosmetics or hair styling materials, moisturizing creams, sunscreens and the like, or oils contained in foods and the like. In particular, a touch panel type mobile device that has been widely used in recent years includes a display unit and an input unit that function as an input unit, and the user directly operates the surface of the display unit/input unit with a fingertip. There are many opportunities to attach oil to the fingertips. Further, among the wearable devices, they are worn in contact with the skin, and in such a use form, there are many opportunities for exposure to oils such as chemicals applied to sebum or skin. If the adhesive layer of the adhesive sheet of the fixing member contacts such an oil component, there may be a problem that the adhesive force is lowered or the adhesive is overflowed. In this regard, for example, in Patent Document 1, it is difficult to soften and swell the adhesive even when the oil is infiltrated, and the double-sided adhesive sheet in which the adhesive does not overflow when the component is fixed is investigated. However, in Patent Document 1, it is not considered to suppress the decrease in the adhesion force due to the contact of the oil component. The present invention has been made in view of the above circumstances, and it is an object of the invention to provide an adhesive sheet which has less adhesive strength reduction and which suppresses the overflow of an adhesive even when it comes into contact with an oil component. [Technical means for solving the problem] According to the present specification, an adhesive sheet comprising an adhesive layer composed of an adhesive of an acrylic polymer as a base polymer is provided. The surface free energy γ of the above adhesive layer is less than 40 mJ/m 2 . Further, in the above adhesive layer, the permeation amount per gram of oleic acid is 1.5 g or more and 5.0 g or less. Since the adhesive sheet of this structure has a low surface energy γ of the adhesive layer, the adhesive layer tends to exhibit good wettability to the adherend. Thereby, the adhesive layer and the adherend are preferably in close contact with each other, and it is possible to suppress the oil from entering the outer edge of the adhesive sheet from the outer edge of the adhesive sheet to the interface between the adhesive layer and the adherend (the interface). Further, the above-mentioned pressure-sensitive adhesive layer has an ability to maintain oleic acid of 1.5 g or more per 1 g in the measurement of the oleic acid permeation amount described below. By exhibiting such oil retaining property, even if the oil is immersed from the outer edge of the adhesive sheet to the subsequent interface, the oil is absorbed (permeated) in the layer of the adhesive layer, and the subsequent interface can be maintained in a state of less oil. In this way, by preventing the oil from immersing from the outer edge of the adhesive sheet to the subsequent interface, and the oil component which is immersed is easily absorbed into the layer (block) of the adhesive layer from the subsequent interface, the contact due to the oil can be effectively suppressed. The resulting adhesion is reduced. Further, by limiting the permeation amount of the oleic acid per 1 g of the adhesive layer to 5.0 g or less, it is possible to prevent the adhesive layer from excessively absorbing the oil and the adhesive from overflowing. In a preferred embodiment of the adhesive sheet, the adhesive layer has a gel fraction of 30% or more and 70% or less. By setting the gel fraction to the above range, it is easy to achieve an adhesive layer having an oleic acid penetration amount in an appropriate range. In still another preferred aspect, the adhesive layer is formed using an adhesive composition comprising the acrylic polymer and a crosslinking agent. There is an advantage in this aspect that the amount of oleic acid permeation (or gel fraction) can be easily adjusted. As the crosslinking agent, a crosslinking agent containing at least an isocyanate crosslinking agent can be preferably used. The adhesive sheet disclosed herein can be preferably applied in such a manner that the above-mentioned adhesive layer contains an adhesive-imparting resin. Since the adhesive layer contains the adhesion-imparting resin, the adhesion of the adhesive layer to the adherend can be improved, and the oil component can be more effectively inhibited from immersing into the subsequent interface from the outer edge of the adhesive sheet. In addition, 50% by weight or more of the adhesion-providing resin is selected from the group consisting of rosin-based adhesion-imparting resin, and it is easy to achieve an oleic acid penetration amount and a surface free energy γ in an appropriate range of the adhesive layer. In one aspect of the adhesive sheet disclosed herein, the monomer component constituting the acrylic polymer contains more than 50% by weight of the ester terminal and has 7 or more and 10 or less carbon atoms (hereinafter sometimes The alkyl (meth)acrylate having an alkyl group in the range of the number of carbon atoms is referred to as "C 7-10 "). According to the technique disclosed herein, even if the acrylic polymer comprising a monomer having a large amount of a C 7-10 alkyl (meth)acrylate is used as a base polymer of the adhesive layer, it can be realized. It is preferable to suppress the adhesive sheet which is caused by the decrease in the adhesion of the oil and the overflow of the adhesive. The adhesive sheet disclosed herein can be preferably subjected to a state in which the monomer component of the acrylic polymer contains more than 5% by weight of a carboxyl group-containing monomer. According to the acrylic polymer having a monomer composition, the oil component such as oleic acid can be maintained in the layer of the adhesive layer. Thereby, the oil component existing at the interface is reduced, and the adhesion due to the oil component can be effectively suppressed from being lowered. In the acrylic polymer containing a monomer composition of a large amount of C 7-10 alkyl (meth)acrylate, it is particularly effective to make the content of the carboxyl group-containing monomer in the monomer component large. The adhesive sheet disclosed herein can be preferably applied in such a manner that the thickness of the above-mentioned adhesive layer is 25 μm or less. In the adhesive sheet in which the thickness of the adhesive layer is relatively small, the adhesive sheet has a small amount of adhesion per unit area, and therefore it is particularly effective to set the oleic acid penetration amount of the adhesive layer to a specific value or more. Preferably, the adhesive sheet of one aspect is formed as a double-sided adhesive sheet having the above-mentioned adhesive layer on one surface and the other surface of the substrate. The double-sided adhesive sheet is used by attaching one surface and the other surface of the adhesive sheet to the adherend, and is easy to be immersed in the oil at the interface with the adherend. Therefore, it is particularly meaningful to use the techniques disclosed herein to suppress the reduction in adhesion resulting from the above oils. The adhesive sheet disclosed herein can be preferably used, for example, for the purpose of a fixing member in a mobile device. As described above, there are many opportunities for the mobile device to come into contact with the oil. Therefore, it is particularly meaningful to use the technique disclosed herein to suppress the decrease in adhesion due to oil and the overflow of the adhesive.

以下，說明本發明之較佳之實施形態。再者，本說明書中未特別談及之事項以外之情況，且實施本發明必須之情況，本領域技術人員可基於針對本說明書記載之發明之實施的教示及申請時之技術常識而理解。本發明可基於本說明書所揭示之內容及該領域之技術常識而實施。而且，以下之附圖中，有時對實現相同作用之構件・部位附上相同符號而說明，有時省略或簡化重複說明。而且，附圖所記載之實施形態係為了明確說明本發明而進行模式化，並不準確表示作為製品而實際提供之本發明之黏著片材的尺寸或比例尺。 本說明書中，所謂「黏著劑」如前所述，係指具有於室溫附近之溫度區域呈現柔軟之固體(黏彈性體)的狀態，藉由壓力簡單接著於被接著體之性質的材料。此處所謂之黏著劑，如「C. A. Dahlquist,「Adhesion: Fundamentals and Practice」, McLaren & Sons, (1966) P.143」所定義，一般而言，可為具有滿足複拉伸彈性模數E＊ (1Hz)＜107 dyne/cm2 之性質之材料(典型而言，於25℃下具有上述性質之材料)。 本說明書中，所謂「(甲基)丙烯醯基」意指包括丙烯醯基及甲基丙烯醯基。同樣，所謂「(甲基)丙烯酸酯」意指包括丙烯酸酯及甲基丙烯酸酯，所謂「(甲基)丙烯酸」意指包括丙烯酸及甲基丙烯酸。 於本說明書中，所謂「丙烯酸系聚合物」，係包含源自於1分子中具有至少一個(甲基)丙烯醯基之單體的單體單元之聚合物，作為構成該聚合物之單體單元，。以下，亦將於1分子中具有至少一個(甲基)丙烯醯基之單體稱為「丙烯酸系單體」。本說明書中之丙烯酸系聚合物定義為包含源自丙烯酸系單體之單體單元的聚合物。 此處所揭示之黏著片材具備由以丙烯酸系聚合物作為基礎聚合物之黏著劑構成之黏著劑層。此處，所謂基礎聚合物係指黏著劑層所含之橡膠狀聚合物(室溫附近之溫度區域顯示橡膠彈性之聚合物)的主要成分。而且，本說明書中，所謂「主要成分」於未特別記錄之情形時，係指超過50重量%而包含之成分。此處所揭示之黏著片材可為於基材(支持體)之單面或雙面具有上述黏著劑層之形態之附基材之黏著片材，可為上述黏著劑層保持於剝離襯墊之形態等無基材之黏著片材。此處所謂黏著片材之概念可包含稱為黏著帶、黏著標記、黏著膜等者。再者，此處所揭示之黏著片材可為輥狀，亦可為單片狀。或者可為進而加工成各種形狀之形態之黏著片材。 此處所揭示之黏著片材例如可為具有如圖1～圖6模式性所示之剖面構造者。其中圖1、圖2係雙面黏著型之附基材之黏著片材的構成例。圖1所示之黏著片材1具有黏著劑層21、22分別設置於基材10之各面(任一均為非剝離性)，該等黏著劑層由至少該黏著劑層側成為剝離面之剝離襯墊31、32分別保護之構成。圖2所示之黏著片材2具有於基材10之各面(任一均為非剝離性)分別設置黏著劑層21、22，該等中一個黏著劑層21由雙面成為剝離面之剝離襯墊31而保護之構成。該種黏著片材2可設為藉由捲繞該黏著片材，將另一黏著劑層22抵接於剝離襯墊31之背面，從而黏著劑層22亦由剝離襯墊31保護之構成。 圖3、圖4係無基材之雙面黏著片材之構成例。圖3所示之黏著片材3具有無基材之黏著劑層21之雙面21A、21B由至少該黏著劑層側成為剝離面之剝離襯墊31、32分別保護的構成。圖4所示之黏著片材4具有無基材之黏著劑層21之一個表面(黏著面)21A由雙面成為剝離面之剝離襯墊31保護的構成，若捲繞其，則可成為黏著劑層21之另一表面(黏著面)21B抵接於剝離襯墊31之背面，藉此其他面21B亦由剝離襯墊31保護之構成。 圖5、圖6係單面黏著型之附基材之黏著片材的構成例。圖5所示之黏著片材5具有於基材10之一面10A(非剝離性)設置黏著劑層21，其黏著劑層21之表面(黏著面)21A由至少該黏著劑層側成為剝離面之剝離襯墊31保護的構成。圖6所示之黏著片材6具有於基材10之一面10A(非剝離性)設置黏著劑層21之構成。基材10之另一面10B成為剝離面，若捲繞黏著片材6，則黏著劑層21抵接於該另一面10B，該黏著劑層之表面(黏著面)21B由基材之另一面10B保護。 ＜黏著劑層＞ 此處所揭示之黏著片材中，其特徵在於，上述黏著劑層之表面自由能量γ未達40 mJ/m2 ，且該黏著劑層之油酸滲透量為1.5 g/g以上且5.0 g/g以下。 (表面自由能量γ) 黏著劑層之表面自由能量γ係由下式：γ＝γd ＋γp ＋γh ；所表示之值。此處，上述式中之γd 、γp 及γh 分別表示表面自由能量之分散成分、極性成分及氫鍵結成分。黏著劑層之表面自由能量γ可使用水、二碘甲烷及1-溴萘作為探針液，根據各探針液之接觸角，依據北崎-畑式(日本接著協會志，Vol.8, N0.3, 1972, pp.131-141)而求出。接觸角之測定可使用市售之接觸角計而進行。作為接觸角計，可使用共和界面科學股份有限公司製造之製品名「CA-X」。測定係使用液滴法，由滴液1500 ms後之液滴形狀測定接觸角。下述實施例中亦採用同樣之方法。 若黏著劑層之表面自由能量γ降低，則有提高被接著體對該黏著劑層之潤濕性，黏著劑層與被接著體之界面(接著界面)之密接性提高之傾向。如此藉由提高接著界面之密接性，可抑制油分自黏著片材之外邊緣浸入至上述接著界面。 若以與被接著體之表面自由能量之關係，更降低黏著劑層之表面自由能量，則有對該被接著體之潤濕性更提高之傾向。因此，藉由更降低黏著劑層之表面自由能量γ，進而提高對特定之被接著體之密接性，而且，可更良好地密接於多種材質之被接著體。就該觀點而言，黏著劑層之表面自由能量γ較佳為大致35 mJ/m2 以下，更佳為大致30 mJ/m2 以下。於一態樣中，黏著劑層之表面自由能量γ可為27 mJ/m2 以下，亦可為25 mJ/m2 以下，進而可為20 mJ/m2 以下。黏著劑層之表面自由能量γ之下限並無特別限制，通常大致7 mJ/m2 以上，較佳為大致10 mJ/m2 以上。黏著劑層之表面自由能量γ例如可根據構成丙烯酸系聚合物之單體成分之組成(下述主單體及視需要使用之副單體之種類及使用量等)、黏著賦予樹脂之種類及使用量等而調整。 (油酸滲透量) 此處所揭示之技術中，黏著劑層之油酸滲透量係利用以下之方法而測定。 ［油酸滲透性評價］ 將測定對象之黏著劑層調製成於厚度10 μm～100 μm左右(例如50 μm)之聚對苯二甲酸乙二酯(PET)膜的非剝離面上具有厚度20 μm之上述黏著劑層的單面黏著片材之形態。例如，將上述黏著劑層於適當之剝離面上以無基材之形態製作，將其貼合於上述PET膜之非剝離面，藉此可調製上述單面黏著片材。將該單面黏著片材切割成縱25 mm、橫25 mm之正方形狀，而製作試驗片。 於不鏽鋼板(SUS304BA板)之表面，於該不鏽鋼板之中央部，利用油性筆描繪於90度之角度交叉之2條標線。於23℃、50%RH之環境下，於描繪上述標線之不鏽鋼板貼附上述試驗片之黏著面，製作測定樣品。此時試驗片係以該試驗片之縱橫之中心線與上述標線一致之方式進行位置對準而貼合。 將上述測定樣品於23℃、50%RH之環境下保持12小時。繼而，測定上述測定樣品之重量(浸漬前重量)後，將該測定樣品浸漬於油酸浴中，於40℃、90%RH之環境下保持2週。其後，將上述測定樣品自油酸浴提起，輕輕擦試附著於周圍之油酸，測定該測定樣品之重量(浸漬後重量)。根據所獲得之測定值，利用以下式： 油酸滲透量＝(浸漬後重量－浸漬前重量)/滲透前之黏著劑重量； 算出黏著劑層每1 g之油酸滲透量(g/g)。於下述之實施例中，亦採用同樣之評價方法。 油酸滲透量為1.5 g/g以上之黏著劑層顯示與油酸滲透量更少之黏著劑層相比更良好之油分保持性。藉此，即便油分自黏著片材之外邊緣浸入至接著界面，該油分被黏著劑層之層內(塊體)吸收，藉此可將接著界面保持為油分較少之狀態。藉此，可有效抑制因存在於接著界面之油分引起之黏著力之降低。而且，藉由自黏著片材之外邊緣浸入至接著界面之油分被黏著劑層之塊體吸收，可抑制上述油分沿著接著界面於貼附黏著片材之範圍的內側部進行的情況。即，可抑制油分自黏著片材之外邊緣的滲透距離。藉此，抑制油分自黏著片材之外邊緣至內側部之影響，可更良好維持作為黏著片材整體之黏著力。進而，藉由黏著劑層之塊體適度吸收油分，該黏著劑層軟化之結果，藉由上述黏著劑層之變形能量，可增強剝離強度。此亦有利地有助於抑制因油分引起之黏著力降低。如此，藉由設為抑制油分自黏著片材之外邊緣浸入至接著界面，且浸入之油分自接著界面容易被黏著劑層之塊體吸收之構成，可有效抑制因油分之接觸引起之黏著力降低。 就更發揮上述效果之觀點而言，黏著劑層之油酸滲透量較佳為大致1.6 g/g以上，更佳為大致1.8 g/g以上。此處所揭示之技術亦可較佳以黏著劑層之油酸滲透量大致2.0 g/g以上(進而大致2.5 g/g以上、例如大致3.0 g/g以上)之態樣而實施。黏著劑層之油酸滲透量之上限，就黏著劑層過分吸收油分，防止黏著劑溢出之情況之觀點而言，較為適當為大致5.0 g/g以下，較佳為大致4.5 g/g以下(例如大致4.0 g/g以下)。較佳之一態樣之黏著片材中，上述黏著劑層之油酸滲透量例如可為大致1.6 g/g以上且大致4.5 g/g以下，更佳為大致1.8 g/g以上且大致4.5 g/g以下。黏著劑層之油酸滲透量例如可根據構成丙烯酸系聚合物之單體成分之組成(下述主單體及視需要所使用之副單體之種類及使用量等)、丙烯酸系聚合物之分子量、交聯劑之種類及使用量、黏著賦予樹脂之種類及使用量等而調整。 亦可藉由上述油酸滲透性評價而進行黏著劑之溢出防止性之評價。具體而言，於上述油酸滲透性評價中，將上述測定樣品剛自油酸浴提起後，以目視測定黏著劑自上述PET膜之外邊緣之溢出距離(溢出寬度)。下述實施例中，亦採用同樣之評價方法。 於較佳之一態樣中，上述黏著劑之溢出寬度可為大致未達1.0 mm(較佳為大致0.5 mm以下、進而較佳為大致0.3 mm以下)。具備具有此種溢出防止性之黏著劑層之黏著片材較佳用於尋求限定之間隔下之接合的用途，例如於行動裝置中固定構件之用途。黏著劑之溢出寬度越小越佳，較為理想為大致0 mm。 而且，根據上述油酸滲透性評價，可測定油酸於黏著片材中之滲透距離。具體而言，將上述測定樣品自油酸浴提起，輕輕擦拭附著於周圍之油酸後，自上述PET膜之外邊緣朝向內側，測定上述不鏽鋼上之標線消失之長度，將其長度設為油酸之滲透距離。下述實施例中亦採用同樣之測定方法。 於較佳之一態樣中，上述油酸之滲透距離較為適當為大致0.5 mm以上，更佳為大致0.8 mm以上，進而較佳為大致1.0 mm以上。而且，上述油酸之滲透距離較佳為大致7.0 mm以下，更佳為大致5.0 mm以下，進而較佳為大致4.0 mm以下(例如大致1.0 mm以上且大致4.0 mm以下)。根據油酸之滲透距離在上述範圍之黏著劑層，有較佳實現此處所揭示之較佳之油酸滲透量的傾向。 (丙烯酸系聚合物) 構成上述黏著劑層之黏著劑包含丙烯酸系聚合物作為基礎聚合物。上述丙烯酸系聚合物較佳為包含(甲基)丙烯酸烷基酯作為主要單體，可進而包含該主單體及具有共聚合性之副單體的單體原料之聚合物。此處所謂主單體係指於上述單體原料中包含超過50重量%之成分。 作為(甲基)丙烯酸烷基酯，例如可較佳使用下述式(1)所表示之化合物。 CH2 =C(R1 )COOR2 (1) 此處，上述式(1)中之R1 為氫原子或甲基。而且，R2 為碳原子數1～20之鏈狀烷基(以下，有時將此種碳原子數之範圍表示為「C1-20 」)。就黏著劑之儲藏彈性模數等觀點而言，較佳為R2 為C1-14 之鏈狀烷基之(甲基)丙烯酸烷基酯，更佳為R2 為C1-10 之鏈狀烷基之(甲基)丙烯酸烷基酯，尤其較佳為R2 為丁基或2-乙基己基之(甲基)丙烯酸烷基酯。 作為R2 為C1-20 之鏈狀烷基之(甲基)丙烯酸烷基酯，例如可列舉：(甲基)丙烯酸甲酯、(甲基)丙烯酸乙酯、(甲基)丙烯酸丙酯、(甲基)丙烯酸異丙酯、(甲基)丙烯酸正丁酯、(甲基)丙烯酸異丁酯、(甲基)丙烯酸第二丁酯、(甲基)丙烯酸戊酯、(甲基)丙烯酸異戊酯、(甲基)丙烯酸己酯、(甲基)丙烯酸庚酯、(甲基)丙烯酸2-乙基己酯、(甲基)丙烯酸辛酯、(甲基)丙烯酸異辛酯、(甲基)丙烯酸壬酯、(甲基)丙烯酸異壬酯、(甲基)丙烯酸癸酯、(甲基)丙烯酸異癸酯、(甲基)丙烯酸十一烷基酯、(甲基)丙烯酸十二烷基酯、(甲基)丙烯酸十三烷基酯、(甲基)丙烯酸十四烷基酯、(甲基)丙烯酸十五烷基酯、(甲基)丙烯酸十六烷基酯、(甲基)丙烯酸十七烷基酯、(甲基)丙烯酸十八烷基酯、(甲基)丙烯酸十九烷基酯、(甲基)丙烯酸二十烷基酯等。該等(甲基)丙烯酸烷基酯可單獨使用1種，或亦可組合2種以上使用。作為尤其較佳之(甲基)丙烯酸烷基酯，可列舉：丙烯酸正丁酯(BA)及丙烯酸2-乙基己酯(2EHA)。 此處所揭示之技術可較佳以構成上述丙烯酸系聚合物之單體成分包含BA及2EHA之至少一者，該單體成分所含之(甲基)丙烯酸烷基酯中BA與2EHA之合計量占75重量%以上(通常為85重量%以上、例如90重量%以上、進而為95重量%以上)之態樣而實施。此處所揭示之技術例如可以上述單體成分所含之(甲基)丙烯酸烷基酯以BA單獨之態樣、2EHA單獨之態樣、包含BA及2EHA之態樣等而實施。 於上述單體成分包含BA及2EHA之情形時，BA與2EHA之重量比(BA/2EHA)並無特別限定，例如可為1/99以上且99/1以下。於較佳之一態樣中，BA/2EHA可為40/60以下(例如1/99以上且40/60以下)，可為20/80以下，可為10/90以下(例如1/99以上且10/90以下)。 此處所揭示之技術可較佳以構成上述丙烯酸系聚合物之單體成分包含多於50重量%之(甲基)丙烯酸C7-10 烷基酯之態樣而實施。如此以(甲基)丙烯酸C7-10 烷基酯作為主單體之丙烯酸系聚合物大致對於油之親和性較高。利用該對油之親和性之高度，將自黏著片材之外邊緣浸入至接著界面之油分適當吸收於黏著劑層之層內，藉此可有效抑制因接觸油分引起之黏著力降低。單體成分中所占之(甲基)丙烯酸C7-10 烷基酯之比率可為60重量%以上，亦可為70重量%以上(例如80重量%以上、進而為85重量%以上)。單體成分中所占之(甲基)丙烯酸C7-10 烷基酯之比率之上限並無特別限制，例如可未達98重量%。通常就容易兼具與其他特性之觀點而言，單體成分中所占之(甲基)丙烯酸C7-10 烷基酯的比率設為97重量%以下較為適當，較佳為95重量%以下(通常為未達95重量%，例如93重量%以下)。(甲基)丙烯酸C7-10 烷基酯可單獨使用1種，或將2種以上組合使用。作為(甲基)丙烯酸C7-10 烷基酯之較佳例，可列舉：2EHA、丙烯酸異辛酯、丙烯酸異壬酯等丙烯酸C7-10 烷基酯。其中，較佳為2EHA。 此處所揭示之技術亦可較佳以構成上述丙烯酸系聚合物之單體成分包含(甲基)丙烯酸C1-6 烷基酯多於50重量%之態樣而實施。如此以(甲基)丙烯酸C1-6 烷基酯作為主單體之丙烯酸系聚合物作為基礎聚合物之情形時，亦可例如將副單體之種類及使用量、交聯劑之種類及使用量、黏著賦予樹脂之種類及使用量等條件適當設定，藉此可獲得顯示此處所揭示之較佳之油酸滲透量的黏著劑層。單體成分所占之(甲基)丙烯酸C1-6 烷基酯之比率可為60重量%以上，70重量%以上(例如85重量%以上、進而為90重量%以上)。單體成分所占之(甲基)丙烯酸C1-6 烷基酯之比率之上限並無特別限制，例如可為99.5重量%以下。通常就兼具與其他特性之觀點而言，單體成分所占之上述(甲基)丙烯酸C1-6 烷基酯之比率設為99重量%以下較為適當，較佳為98重量%以下(例如97重量%以下)。(甲基)丙烯酸C1-6 烷基酯可單獨使用1種，或將2種以上組合使用。作為(甲基)丙烯酸C1-6 烷基酯之較佳例，可列舉BA。 作為主單體之(甲基)丙烯酸烷基酯及具有共聚合性之副單體有助於丙烯酸系聚合物導入交聯點，或提高丙烯酸系聚合物之凝聚力。作為副單體，例如可將如以下之含官能基之單體單獨使用1種，或將2種以上組合使用。 含羧基之單體：例如丙烯酸(AA)、甲基丙烯酸(MAA)、(甲基)丙烯酸羧基乙酯、丁烯酸、異丁烯酸等乙烯性不飽和單羧酸；順丁烯二酸、亞甲基丁二酸、甲基順丁烯二酸等乙烯性不飽和二羧酸及其酸酐(順丁烯二酸酐、亞甲基丁二酸酐等)。 含羥基之單體：例如(甲基)丙烯酸2-羥基乙酯、(甲基)丙烯酸2-羥基丙酯、(甲基)丙烯酸3-羥基丙酯、(甲基)丙烯酸4-羥基丁酯等(甲基)丙烯酸羥基烷基酯類；乙烯醇、烯丙醇等不飽和醇類；聚丙二醇單(甲基)丙烯酸酯。 含醯胺基之單體：例如(甲基)丙烯醯胺、N,N-二甲基(甲基)丙烯醯胺、N-丁基(甲基)丙烯醯胺、N-羥甲基(甲基)丙烯醯胺、N-羥甲基丙烷(甲基)丙烯醯胺、N-甲氧基甲基(甲基)丙烯醯胺、N-丁氧基甲基(甲基)丙烯醯胺。 含胺基之單體：例如(甲基)丙烯酸胺基乙酯、(甲基)丙烯酸N,N-二甲基胺基乙酯、(甲基)丙烯酸第三丁基胺基乙酯。 具有環氧基之單體：例如(甲基)丙烯酸縮水甘油酯、(甲基)丙烯酸甲基縮水甘油酯、烯丙基縮水甘油醚。 含氰基之單體：例如丙烯腈、甲基丙烯腈。 含酮基之單體：例如二丙酮(甲基)丙烯醯胺、二丙酮(甲基)丙烯酸酯、乙烯基甲基酮、乙烯基乙基酮、乙醯乙酸烯丙酯、乙醯乙酸乙烯酯。 具有含氮原子之環之單體：例如N-乙烯基-2-吡咯啶酮、N-甲基乙烯基吡咯啶酮、N-乙烯基吡啶、N-乙烯基哌啶酮、N-乙烯基嘧啶、N-乙烯基哌?? 、N-乙烯基吡?? 、N-乙烯基吡咯、N-乙烯基咪唑、N-乙烯基㗁唑、N-乙烯基??啉、N-乙烯基己內醯胺、N-(甲基)丙烯醯基??啉。 含烷氧基烯烷基之單體：例如3-(甲基)丙烯醯氧基丙基三甲氧基矽烷、3-(甲基)丙烯醯氧基丙基三乙氧基矽烷、3-(甲基)丙烯醯氧基丙基甲基二甲氧基矽烷、3-(甲基)丙烯醯氧基丙基甲基二乙氧基矽烷。 上述含官能基之單體可單獨使用1種，或將2種以上組合使用。上述含官能基之單體之中，就可較佳實現如上述之交聯點之導入或凝聚力之提高而言，可較佳使用含羧基之單體或含羥基之單體。作為含羧基之單體之較佳例，可列舉丙烯酸及甲基丙烯酸。該等可將任一種單獨使用或將2種組合使用。作為含羥基之單體，可列舉如丙烯酸2-羥基乙酯或(甲基)丙烯酸4-羥基丁酯等之類於碳原子數2～4左右之直鏈烷基的末端具有羥基之(甲基)丙烯酸羥基烷基酯。含羥基之單體可單獨使用1種，或將2種以上組合使用。可將含羧基之單體與含羥基之單體組合使用。 於構成丙烯酸系聚合物之單體成分含有含官能基之單體之情形時，該單體成分所占之含官能基之單體的比率並無特別限定。通常就此處所揭示之較佳之油酸滲透量中獲得適當之凝聚性之觀點而言，較佳為含官能基之單體之比率為0.1重量%以上且40重量%以下(例如為0.5重量%以上且30重量%以下、通常為1重量%以上且20重量%以下)左右。 於構成丙烯酸系聚合物之單體成分含有含羧基之單體之情形時，該單體成分所占之含羧基之單體的比率，就凝聚性等觀點而言，通常設為0.5重量%以上(較佳為1重量%以上、例如2重量%以上)、20重量%以下(較佳為18重量%以下、例如15重量%以下)較為適當。 此處所揭示之技術可較佳以上述單體成分含有含羧基之單體大致3重量%以上(較佳為大致5重量%以上)的態樣而實施。根據該單體組成之丙烯酸系聚合物，藉由該聚合物具有之羧基與油酸之相互作用，可將吸收之油酸良好保持於黏著劑層之層內(塊體)。藉此可將接著界面維持為油酸較少之狀態，有效抑制因油酸之滲透引起之黏著力降低。就該觀點而言，單體成分中之含羧基之單體的含量較佳為大致多於5重量%，亦可為大致7重量%以上，亦可為大致8重量%以上，進而可為大致9重量%以上。含羧基之單體之含量的上限並無特別限制，通常大致18重量%以下較為適當，可為大致15重量%以下(例如大致12重量%以下)。包含較多(甲基)丙烯酸C7-10 烷基酯之單體組成的丙烯酸系聚合物(例如，以(甲基)丙烯酸C7-10 烷基酯作為主單體之丙烯酸系聚合物)中，使單體成分中之含羧基之單體(例如AA)的含量較多尤其有效果。 於構成丙烯酸系聚合物之單體成分含有含羥基之單體之情形時，其含量通常為上述單體成分之大致0.001重量%以上且大致10重量%以下(例如大致0.01重量%以上且大致5重量%以下、較佳為大致0.02重量%以上且大致2重量%以下)較為適當。 作為構成丙烯酸系聚合物之單體成分，以提高該丙烯酸系聚合物之凝聚力等為目的，可使用上述副單體以外之其他共聚合成分。作為該共聚合成分之例，可列舉：乙酸乙烯酯、丙酸乙烯酯、月桂酸乙烯酯等乙烯酯系單體；苯乙烯、取代苯乙烯(α-甲基苯乙烯等)、乙烯基甲苯等芳香族乙烯基化合物；(甲基)丙烯酸環己酯、(甲基)丙烯酸環戊酯、(甲基)丙烯酸異基酯等(甲基)丙烯酸環烷基酯；(甲基)丙烯酸芳酯(例如(甲基)丙烯酸苯酯)、(甲基)丙烯酸芳氧基烷基酯(例如(甲基)丙烯酸苯氧基乙酯)、(甲基)丙烯酸芳基烷基酯(例如(甲基)丙烯酸苄酯)等含芳香族性環之(甲基)丙烯酸酯；乙烯、丙烯、異戊二烯、丁二烯、異丁烯等烯烴系單體；氯乙烯、偏二氯乙烯等含氯單體；2-(甲基)丙烯醯氧基乙基異氰酸酯等含異氰酸酯基之單體；(甲基)丙烯酸甲氧基乙酯、(甲基)丙烯酸乙氧基乙酯等含烷氧基之單體；甲基乙烯醚、乙基乙烯醚等乙烯醚系單體；1,6-己二醇二(甲基)丙烯酸酯、三羥甲基丙烷三(甲基)丙烯酸酯等於1分子中具有2個以上(例如3個以上)之聚合性官能基(例如(甲基)丙烯醯基)的多官能單體；等。 該其他共聚合成分之量只要根據目的及用途適當選擇即可，並無特別限定，通常較佳為設為單體成分之10重量%以下。例如，於使用乙烯酯系單體(例如乙酸乙烯酯)作為上述其他共聚合成分之情形時，其含量可設為單體成分之例如大致0.1重量%以上(通常大致0.5重量%以上)，而且，大致20重量%以下(通常大致10重量%以下)較為適當。 構成丙烯酸系聚合物之單體成分的組成以該丙烯酸系聚合物之玻璃轉移溫度(Tg)為大致-15℃以下(例如大致-70℃以上且-15℃以下)設計較為適當。此處，所謂丙烯酸系聚合物之Tg係指基於上述單體成分之組成，由Fox之式求出之Tg。所謂Fox之式，如以下所示，為共聚物之Tg與將構成該共聚物之單體分別均聚之均聚物的玻璃轉移溫度Tgi之關係式。 1/Tg＝Σ(Wi/Tgi) 再者，上述Fox之式中，Tg表示共聚物之玻璃轉移溫度(單元：K)、Wi表示該共聚物中之單體i之重量分率(重量基準之共聚合比率)、Tgi表示單體i之均聚物的玻璃轉移溫度(單元：K)。 作為算出Tg所使用之均聚物的玻璃轉移溫度，使用公知資料記載之值。例如，關於以下所列舉之單體，使用以下之值，作為該單體之均聚物的玻璃轉移溫度。 丙烯酸2-乙基己酯 -70℃ 丙烯酸正丁酯 -55℃ 丙烯酸乙酯 -22℃ 丙烯酸甲酯 8℃ 甲基丙烯酸甲酯 105℃ 丙烯酸2-羥基乙酯 -15℃ 丙烯酸4-羥基丁酯 -40℃ 乙酸乙烯酯 32℃ 苯乙烯 100℃ 丙烯酸 106℃ 甲基丙烯酸 228℃ 關於上述例示以外之單體的均聚物之玻璃轉移溫度，使用「Polymer Handbook」(第3版，John Wiley & Sons, Inc., 1989)中記載之數值。關於本文獻中記載有複數種之值的單體，採用最高值。 關於上述文獻中亦未記載有均聚物之玻璃轉移溫度的單體，設為使用藉由以下測定方法獲得之值者。 具體而言，於具備溫度計、攪拌機、氮導入管及回流冷卻管之反應器中投入單體100重量份、2,2'-偶氮雙異丁腈0.2重量份及作為聚合溶劑之乙酸乙酯200重量份，一面流通氮氣一面攪拌1小時。如此方式除去聚合物體系內之氧後，於63℃下升溫反應10小時。繼而，冷卻至室溫，獲得固形物成分濃度33重量%之均聚物溶液。繼而，將該均聚物溶液流延塗佈於剝離襯墊上，進行乾燥，製作厚度約2 mm之試驗樣品(片材狀之均聚物)。將該試驗樣品沖裁為直徑7.9 mm之圓盤狀，用平行板夾住，使用黏彈性試驗機(ARES，Rheometrics公司製造，機種名「ARES」)，一面施加頻率1 Hz之剪切應變，一面以5℃/分鐘之升溫速度於溫度區域-70℃～150℃內，藉由剪切模式測定黏彈性，並將相當於tanδ之峰頂溫度之溫度作為均聚物之Tg。 並無特別限定，但就對被接著體或基材膜之密接性之觀點而言，丙烯酸系聚合物之Tg有利為大致-25℃以下，較佳為大致-35℃以下，更佳為大致-40℃以下。而且，就黏著劑層之凝聚力之觀點而言，丙烯酸系聚合物之Tg通常為大致-75℃以上，較佳為大致-70℃以上。此處所揭示之技術可較佳以丙烯酸系聚合物之Tg為大致-65℃以上且大致-40℃以下(例如較佳為-65℃以上且大致-45℃以下)的態樣而實施。於較佳之一態樣中，丙烯酸系聚合物之Tg可為大致-65℃以上且大致-55℃以下。丙烯酸系聚合物之Tg可藉由適當改變單體組成(即，該聚合物合成所使用之單體之種類或使用量比)而調整。 獲得丙烯酸系聚合物之方法並無特別限定，可適當採用作為溶液聚合法、乳液聚合法、塊體聚合法、懸浮聚合法、光聚合法等丙烯酸系聚合物之合成方法而已知之各種聚合方法。例如可較佳採用溶液聚合法。作為進行溶液聚合時之單體供給方法，可適當採用將全單體原料一次供給之一次添加方式、連續供給(滴加)方式、分割供給(滴加)方式等。聚合溫度可根據使用之單體及溶劑之種類、聚合起始劑之種類等而適當選擇，例如可設為20℃～170℃左右(通常為40℃～140℃左右)。於較佳之一態樣中，可將聚合溫度設為大致75℃以下(更佳為大致65℃以下，例如大致45℃～65℃左右)。 溶液聚合所使用之溶劑(聚合溶劑)可適當選自先前公知之有機溶劑。例如，可使用選自甲苯、二甲苯等芳香族化合物類(例如芳香族烴類)；乙酸乙酯、乙酸丁酯等乙酸酯類；己烷、環己烷、甲基環己烷等脂肪族或脂環式烴類；1,2-二環乙烷等鹵化烷烴類；異丙醇等低級醇類(例如碳原子數1～4之一元醇類)；第三丁基甲醚等醚類；甲基乙基酮、丙酮等酮類；等中之任1種溶劑、或2種以上之混合溶劑。 聚合所使用之起始劑可根據聚合方法之種類，適當選自先前公知之聚合起始劑。例如可較佳使用2,2'-偶氮雙異丁腈(AIBN)等偶氮系聚合起始劑之1種或2種以上。作為聚合起始劑之其他較佳例，可列舉：過氧化苯甲醯(BPO)、過氧化氫等過氧化物系起始劑。作為其他聚合起始劑，可列舉：過硫酸鉀等過硫酸鹽；苯基取代乙烷等取代乙烷系起始劑；芳香族羰基化合物；過氧化物與還原劑之組合而成之氧化還原系起始劑；等。此種聚合起始劑可單獨使用1種，或將2種以上組合使用。聚合起始劑之使用量只要為通常之使用量即可，例如可相對於單體成分100重量份選自大致0.005～1重量份左右(通常大致0.01～1重量份左右)之範圍。 根據上述溶液聚合，獲得丙烯酸系聚合物溶解於有機溶劑之形態的聚合反應液。此處所揭示之技術中之黏著劑層可為由上述聚合反應液或對該反應液實施適當之後處理而獲得之包含丙烯酸系聚合物溶液的黏著劑組合物形成者。作為上述丙烯酸系聚合物溶液，可使用將上述聚合反應液視需要調製成適當黏度(濃度)者。或者，可使用利用溶液聚合以外之聚合方法(例如乳液聚合、光聚合、塊體聚合等)合成丙烯酸系聚合物，將該丙烯酸系聚合物溶解於有機溶劑而調製之丙烯酸系聚合物溶液。 丙烯酸系聚合物之重量平均分子量(Mw)並無特別限定，例如可為大致10×104 以上且500×104 以下。此處所謂Mw係指利用GPC(凝膠滲透層析法)獲得之標準聚苯乙烯換算之值。作為GPC裝置，例如可使用機種名「HLC-8320GPC」(管柱：TSK gel GMH-H(S)，東曹公司製造)。就黏著性能或耐油性之觀點而言，丙烯酸系聚合物之Mw較佳為大致30×104 以上且200×104 以下(更佳為大致45×104 以上且150×104 以下，例如大致65×104 以上且150×104 以下)的範圍。於較佳之一態樣中，丙烯酸系聚合物之Mw可為大致75×104 以上且大致140×104 以下(例如大致90×104 以上且大致140×104 以下)。 (交聯劑) 黏著劑層形成所使用之黏著劑組合物(較佳為溶劑型黏著劑組合物)較佳為含有交聯劑，作為任意成分。此處所揭示之技術之黏著劑層可以上述交聯劑以交聯反應後之形態、交聯反應前之形態、部分交聯反應之形態、該等之中間或複合形態等含有。上述交聯劑通常以專門之交聯反應後之形態包含於黏著劑層。 交聯劑之種類並無特別限制，可適當選自先前公知之交聯劑中。作為此種交聯劑，例如可列舉：異氰酸酯系交聯劑、環氧系交聯劑、㗁唑啉系交聯劑、氮丙啶系交聯劑、三聚氰胺系交聯劑、碳二醯亞胺系交聯劑、肼系交聯劑、胺系交聯劑、過氧化物系交聯劑、金屬螯合物系交聯劑、金屬烷氧化物系交聯劑、金屬鹽系交聯劑等。交聯劑可將1種單獨使用或將2種以上組合使用。使用之交聯劑之種類及量例如可以形成此處所揭示之顯示較佳之油酸滲透量的黏著劑層之方式而設定。作為此處所揭示之技術中可較佳使用之交聯劑，可例示異氰酸酯系交聯劑及環氧系交聯劑。 作為異氰酸酯系交聯劑，可較佳使用多官能異氰酸酯(係指每1分子具有平均2個以上之異氰酸酯基的化合物，包含具有異氰尿酸酯構造者)。異氰酸酯系交聯劑可單獨使用1種，或將2種以上組合使用。 作為多官能異氰酸酯之例，可列舉：脂肪族聚異氰酸酯類、脂環族聚異氰酸酯類、芳香族聚異氰酸酯類等。 作為脂肪族聚異氰酸酯類之具體例，可列舉：1,2-伸乙基二異氰酸酯；1,2-四亞甲基二異氰酸酯、1,3-四亞甲基二異氰酸酯、1,4-四亞甲基二異氰酸酯等四亞甲基二異氰酸酯；1,2-六亞甲基二異氰酸酯、1,3-六亞甲基二異氰酸酯、1,4-六亞甲基二異氰酸酯、1,5-六亞甲基二異氰酸酯、1,6-六亞甲基二異氰酸酯、2,5-六亞甲基二異氰酸酯等六亞甲基二異氰酸酯；2-甲基-1,5-戊烷二異氰酸酯、3-甲基-1,5-戊烷二異氰酸酯、離胺酸二異氰酸酯等。 作為脂環族聚異氰酸酯類之具體例，可列舉：異佛爾酮二異氰酸酯；1,2-環己基二異氰酸酯、1,3-環己基二異氰酸酯、1,4-環己基二異氰酸酯等環己基二異氰酸酯；1,2-環戊基二異氰酸酯、1,3-環戊基二異氰酸酯等環戊基二異氰酸酯；氫化苯二甲基二異氰酸酯、氫化甲伸苯基二異氰酸酯、氫化二苯基甲烷二異氰酸酯、氫化四甲基二甲伸苯基二異氰酸酯、4,4'-二環己基甲烷二異氰酸酯等。 作為芳香族聚異氰酸酯類之具體例，可列舉：2,4-甲伸苯基二異氰酸酯、2,6-甲伸苯基二異氰酸酯、4,4'-二苯基甲烷二異氰酸酯、2,4'-二苯基甲烷二異氰酸酯、2,2'-二苯基甲烷二異氰酸酯、4,4'-二苯醚二異氰酸酯、2-硝基二苯基-4,4'-二異氰酸酯、2,2'-二苯基丙烷-4,4'-二異氰酸酯、3,3'-二甲基二苯基甲烷-4,4'-二異氰酸酯、4,4'-二苯基丙烷二異氰酸酯、間苯二異氰酸酯、對苯二異氰酸酯、萘-1,4-二異氰酸酯、萘-1,5-二異氰酸酯、3,3'-二甲氧基二苯基-4,4'-二異氰酸酯、苯二甲基-1,4-二異氰酸酯、苯二甲基-1,3-二異氰酸酯等。 作為較佳之多官能異氰酸酯，可例示每1分子平均具有3個以上異氰酸酯基之多官能異氰酸酯。該3官能以上之異氰酸酯可為2官能或3官能以上之異氰酸酯的多聚物(例如2聚物或3聚物)、衍生物(例如多元醇與2分子以上之多官能異氰酸酯之加成反應生成物)、聚合物等。例如可列舉：二苯基甲烷二異氰酸酯之2聚物或3聚物、六亞甲基二異氰酸酯之異氰尿酸酯體(異氰尿酸酯構造之3聚物加成物)、三羥甲基丙烷與甲伸苯基二異氰酸酯之反應生成物、三羥甲基丙烷與六亞甲基二異氰酸酯之反應生成物、聚亞甲基聚苯基異氰酸酯、聚醚聚異氰酸酯、聚酯聚異氰酸酯等多官能異氰酸酯。作為該多官能異氰酸酯之市售品，可列舉：旭化成化學公司製造之商品名「多耐德TPA-100」、東曹公司製造之商品名「Coronate L」、東曹公司製造之商品名「Coronate HL」、東曹公司製造之商品名「Coronate HK」、東曹公司製造之商品名「Coronate HX」、東曹公司製造之商品名「Coronate 2096」等。 使用異氰酸酯系交聯劑之態樣中，其使用量並無特別限定。異氰酸酯系交聯劑之使用量例如相對於丙烯酸系聚合物100重量份，可設為大致0.5重量份以上且大致10重量份以下。就獲得此處所揭示之較佳之油酸滲透量的觀點而言，異氰酸酯系交聯劑相對於丙烯酸系聚合物100重量份之使用量通常設為大致1重量份以上較為適當，較佳為大致1.5重量份以上。而且，異氰酸酯系交聯劑相對於丙烯酸系聚合物100重量份之使用量通常設為大致8重量份以下較為適當，較佳為設為大致5重量份以下(例如大致未達4重量份)。 作為環氧系交聯劑，可無特別限制使用於1分子中具有2個以上環氧基之化合物。較佳為於1分子中具有3～5個環氧基之環氧系交聯劑。環氧系交聯劑可單獨使用1種或將2種以上組合使用。 並無特別限定，作為環氧系交聯劑之具體例，例如可列舉：N,N,N',N'-四縮水甘油基-間二甲苯二胺、1,3-雙(N,N-二縮水甘油基胺基甲基)環己烷、1,6-己二醇二縮水甘油醚、聚乙二醇二縮水甘油醚、聚甘油聚縮水甘油醚等。作為環氧系交聯劑之市售品，可列舉：三菱氣體化學公司製造之商品名「TETRAD-C」及商品名「TETRAD-X」、DIC公司製造之商品名「EPICLON CR-5L」、長瀨化成公司製造之商品名「DENACOL EX-512」、日產化學工業公司製造之商品名「TEPIC-G」等。 使用環氧系交聯劑之態樣中，其使用量並無特別限定。環氧系交聯劑之使用量例如相對於丙烯酸系聚合物100重量份，可設為超過0重量份且為大致1重量份以下(較佳為大致0.001～0.5重量份)。就較佳發揮凝聚力提高之效果之觀點而言，通常環氧系交聯劑之使用量相對於丙烯酸系聚合物100重量份設為大致0.002重量份以上較為適當，較佳為大致0.005重量份以上，更佳為大致0.008重量份以上。而且，就避免因過度交聯引起之油酸滲透量之不足的觀點而言，通常環氧系交聯劑之使用量相對於丙烯酸系聚合物100重量份大致0.2重量份以下較為適當，較佳為大致0.1重量份以下，更佳為大致未達0.05重量份。 此處所揭示之技術可較佳以至少使用異氰酸酯系交聯劑作為交聯劑之態樣而實施。該態樣之例中包含單獨使用異氰酸酯系交聯劑之態樣，及將異氰酸酯系交聯劑與其他交聯劑組合使用之態樣。於下述基材膜之至少一個表面具有黏著劑層之形態的黏著片材中，就提高對該基材膜之抓固性之觀點而言，使用異氰酸酯系交聯劑特別有意義。 作為與異氰酸酯系交聯劑組合使用之交聯劑的一較佳例，可列舉環氧系交聯劑。藉由將環氧系交聯劑與異氰酸酯系交聯劑組合使用，可較佳實現此處所揭示之較佳之油酸滲透量。而且，可確保對基材膜(支持基材)之密接性，並且進而提高黏著劑層之凝聚力。 於包含環氧系交聯劑與異氰酸酯系交聯劑之態樣中，環氧系交聯劑之含量與異氰酸酯系交聯劑之含量的關係並無特別限定。環氧系交聯劑之含量例如可設為異氰酸酯系交聯劑之含量的大致1/20以下。就更較佳兼具對被接著體及基材膜之密接性及凝聚力的觀點而言，環氧系交聯劑之含量設為異氰酸酯系交聯劑之含量的大致1/30以下較為適當，較佳為大致1/40以下(例如1/50以下)。而且，就較佳發揮因將環氧系交聯劑與異氰酸酯系交聯劑組合使用獲得之效果之觀點而言，通常，環氧系交聯劑之含量設為異氰酸酯系交聯劑之含量的大致1/1000以上，例如大致1/500以上較為適當。 (黏著賦予樹脂) 作為上述黏著賦予樹脂，可使用選自酚系黏著賦予樹脂、萜烯系黏著賦予樹脂、改性萜烯系黏著賦予樹脂、松香系黏著賦予樹脂、烴系黏著賦予樹脂、環氧系黏著賦予樹脂、聚醯胺系黏著賦予樹脂、彈性體系黏著賦予樹脂、酮系黏著賦予樹脂等公知之各種黏著賦予樹脂中之1種或2種以上。藉由使用黏著賦予樹脂，可改善黏著劑層對被接著體之密接性，有效抑制油分自黏著片材之外邊緣浸入至接著界面。例如，可縮短上述因油酸滲透性評價引起之油酸之滲透距離。所使用之黏著賦予樹脂之種類及量可以例如滿足形成此處所揭示之較佳之油酸滲透量及表面自由能量γ的黏著劑層之方式而設定。 酚系黏著賦予樹脂之例包含萜烯酚樹脂、氫化萜烯酚樹脂、烷基酚樹脂及松香酚樹脂。 所謂萜烯酚樹脂係指包含萜烯殘基及酚殘基之聚合物，概念為包含萜烯類與酚化合物之共聚物(萜烯-酚共聚物樹脂)、將萜烯類或其均聚物或共聚物進行酚改性而成者(酚改性萜烯樹脂)雙方的概念。作為構成此種萜烯酚樹脂之萜烯類之較佳例，可列舉：α-蒎烯、β-蒎烯、檸檬烯(包含d體、l體及d/l體(二戊烯))等單萜烯類。所謂氫化萜烯酚樹脂係指具有將此種萜烯酚樹脂氫化之構造的氫化萜烯酚樹脂。亦有時稱為氫化萜烯酚樹脂。 烷基酚樹脂係由烷基酚與甲醛獲得之樹脂(油性酚樹脂)。作為烷基酚樹脂之例，可列舉酚醛清漆型及可溶酚醛型者。 松香酚樹脂典型而言，係松香類或上述各種松香衍生物(包含松香酯類、不飽和脂肪酸改性松香類及不飽和脂肪酸改性松香酯類)之酚改性物。松香酚樹脂之例包含利用於松香類或上述各種松香衍生物以酸觸媒加成酚進行熱聚合之方法等而獲得之松香酚樹脂。 該等酚系黏著賦予樹脂之中，較佳為萜烯酚樹脂、氫化萜烯酚樹脂及烷基酚樹脂，更佳為萜烯酚樹脂及氫化萜烯酚樹脂，其中，較佳為萜烯酚樹脂。 萜烯系黏著賦予樹脂之例中包含α-蒎烯、β-蒎烯、d-檸檬烯、l-檸檬烯、二戊烯等萜烯類(例如單萜烯類)聚合物。可為1種萜烯類之均聚物，亦可為2種以上之萜烯類之共聚物。作為1種萜烯類之均聚物，可列舉：α-蒎烯聚合物、β-蒎烯聚合物、二戊烯聚合物等。 作為改性萜烯樹脂之例，可列舉將上述萜烯樹脂改性而成者。具體而言，可例示苯乙烯改性萜烯樹脂、氫化萜烯樹脂等。 此處所謂松香系黏著賦予樹脂之概念包含松香類及松香衍生物樹脂雙方。松香類之例包含膠松香、木松香、妥爾油松香等未改性松香(生松香)；將該等未改性松香藉由氫化、歧化、聚合等改性而獲得之改性松香(氫化松香、歧化松香、聚合松香、其他經化學修飾之松香等)；。 松香衍生物樹脂典型而言為如上述之松香類衍生物。此處所謂之松香系樹脂之概念包含未改性松香之衍生物及改性松香(包含氫化松香、歧化松香及聚合松香)的衍生物。例如可列舉：作為未改性松香與醇類之酯之未改性松香酯、或作為改性松香與醇類之酯之改性松香酯等松香酯類；例如將松香類利用不飽和脂肪酸改性之不飽和脂肪酸改性松香類；例如，將松香酯類利用不飽和脂肪酸改性之不飽和脂肪酸改性松香酯類；例如將松香類或如上述之各種松香衍生物(包含松香酯類、不飽和脂肪酸改性松香類及不飽和脂肪酸改性松香酯類)之羧基進行還原處理之松香醇類；例如松香類或上述各種松香衍生物之金屬鹽；等。作為松香酯類之具體例，可列舉：未改性松香或改性松香(氫化松香、歧化松香、聚合松香等)之甲酯、三乙二醇酯、甘油酯、季戊四醇酯等。 作為烴系黏著賦予樹脂之例，可列舉：脂肪族系烴樹脂、芳香族系烴樹脂、脂肪族系環狀烴樹脂、脂肪族・芳香族系石油樹脂(苯乙烯-烯烴系共聚物等)、脂肪族・脂環族系石油樹脂、氫化烴樹脂、薰草咔系樹脂、薰草咔茚系樹脂等各種烴系樹脂。 黏著賦予樹脂之軟化點並無特別限定。就提高凝聚力之觀點而言，於一態樣中，可較佳採用軟化點(軟化溫度)大致80℃以上(較佳為大致100℃以上)之黏著賦予樹脂。此處所揭示之技術可較佳以具有上述軟化點之黏著賦予樹脂於黏著劑層所含之黏著賦予樹脂整體中超過50重量%(更佳為超過70重量%，例如超過90重量%)的態樣而實施。例如，可較佳使用具有此種軟化點之酚系黏著賦予樹脂(萜烯酚樹脂等)。於較佳之一態樣中，可使用軟化點大致135℃以上(進而大致140℃以上)的萜烯酚樹脂。黏著賦予樹脂之軟化點之上限並無特別限制。就對被接著體或基材膜之密接性之觀點而言，於一態樣中，可較佳使用軟化點大致200℃以下(更佳為大致180℃以下)的黏著賦予樹脂。再者，黏著賦予樹脂之軟化點可基於JIS K2207規定之軟化點試驗方法(環球法)而測定。 使用黏著賦予樹脂之態樣中，該黏著賦予樹脂之含量並無特別限定。黏著賦予樹脂之含量例如相對於丙烯酸系聚合物100重量份，可為大致5重量份以上，亦可為大致8重量份以上(例如大致10重量份以上)。此處所揭示之技術亦可較佳以黏著賦予樹脂相對於丙烯酸系聚合物100重量份之含量大致15重量份以上(例如25重量份以上)之態樣而實施。黏著賦予樹脂之含量之上限並無特別限定。就與丙烯酸系聚合物之相溶性或初期接著性之觀點而言，於一態樣中，通常黏著賦予樹脂相對於丙烯酸系聚合物100重量份之含量設為大致70重量份以下較為適當，較佳為大致55重量份以下，更佳為大致45重量份以下(例如大致40重量份以下)。 使用黏著賦予樹脂之態樣中，黏著賦予樹脂之總量之50重量%以下較佳為選自松香系黏著賦予樹脂以外之黏著賦予樹脂中。松香系黏著賦予樹脂於黏著賦予樹脂之總量中所占之比率較佳為25重量%以下，更佳為10重量%以下(例如未達5重量%)。 而且，松香系黏著賦予樹脂之使用量相對於丙烯酸系聚合物100重量份，較佳為大致未達10重量份，更佳為未達5重量份。松香系黏著賦予樹脂之使用根據其種類及使用量，容易成為使油酸滲透量過度上升之主要原因。而且，存在藉由使用松香系黏著賦予樹脂亦使表面自由能量γ上升之傾向。藉由將松香系黏著賦予樹脂相對於丙烯酸系聚合物100重量份之使用量限制於未達10重量份，容易獲得油酸滲透量及表面自由能量γ在較佳範圍之黏著劑層。此處所揭示之技術亦可以黏著劑層實質上不包含松香系黏著賦予樹脂之態樣而實施。 作為較佳之一態樣，可列舉上述黏著賦予樹脂包含1種或2種以上之酚系黏著賦予樹脂(例如萜烯酚樹脂)的態樣。酚系黏著賦予樹脂例如存在與松香系黏著賦予樹脂相比，對油之親和性較低的傾向。因此，藉由使用酚系黏著賦予樹脂，可抑制油酸滲透量之過度上升，並且發揮改善黏著劑層對被接著體之密接性的效果(例如縮短滲透距離之效果)。此處所揭示之技術例如可以黏著賦予樹脂之總量大致25重量%以上(更佳為大致30重量%以上)為萜烯酚樹脂之態樣而實施。黏著賦予樹脂之總量之大致50重量%以上可為萜烯酚樹脂，大致80重量%以上(例如大致90重量%以上)可為萜烯酚樹脂。黏著賦予樹脂之實質全部(例如大致95重量%以上且100重量%以下，進而大致99重量%以上且100重量%以下)可為萜烯酚樹脂。酚系黏著賦予樹脂(例如萜烯酚樹脂)之含量相對於丙烯酸系聚合物100重量份，大致5重量份以上且大致45重量份以下(例如大致5重量份以上且大致40重量份以下)較為適當，較佳為大致8重量份以上且大致35重量份以下。 並無特別限定，作為此處所揭示之技術中之黏著賦予樹脂，可使用羥值未達30 mgKOH/g(例如未達20 mgKOH/g)之黏著賦予樹脂。以下有時將羥值未達30 mgKOH/g之黏著賦予樹脂稱為「低羥值樹脂」。低羥值樹脂之羥值可為大致15 mgKOH/g以下，亦可為大致10 mgKOH/g以下。低羥值樹脂之羥值之下限並無特別限定，實質上可為0 mgKOH/g。此種低羥值樹脂(例如萜烯酚樹脂)例如可較佳用於與將(甲基)丙烯酸C7-10 烷基酯作為主單體之丙烯酸系聚合物的組合，可良好發揮改善黏著劑層對被接著體之密接性的效果(例如縮短滲透距離之效果)。 並無特別限定，作為此處所揭示之技術中之黏著賦予樹脂，可使用羥值為30 mgKOH/g以上之黏著賦予樹脂。以下，有時將羥值為30 mgKOH/g以上之黏著賦予樹脂稱為「高羥值樹脂」。高羥值樹脂之羥值之上限並無特別限定。就與丙烯酸系聚合物之相溶性等觀點而言，高羥值樹脂之羥值通常大致200 mgKOH/g以下較為適當，較佳為大致180 mgKOH/g以下，更佳為大致160 mgKOH/g以下、進而較佳為大致140 mgKOH/g以下。包含此種高羥值樹脂(例如萜烯酚樹脂)之黏著賦予樹脂例如較佳用於與以(甲基)丙烯酸C1-6 烷基酯作為主單體之丙烯酸系聚合物的組合，可良好發揮改善黏著劑層對被接著體之密接性的效果(例如縮短滲透距離之效果)。 此處，作為上述羥值之值，可採用由JIS K0070：1992規定之電位差滴定法測定之值。具體之測定方法如以下所示。 ［羥值之測定方法］ 1.試劑 (1)作為乙醯化試劑，使用選取乙酸酐約12.5 g(約11.8 mL)，於其中添加吡啶，使總量為50 mL，充分攪拌而成者。或者使用選取乙酸酐約25 g(約23.5 mL)，於其中添加吡啶，使總量為100 mL，充分攪拌而成者。 (2)作為測定試劑，使用0.5 mol/L氫氧化鉀乙醇溶液。 (3)其他準備甲苯、吡啶、乙醇及蒸餾水。 2.操作 (1)於平底燒瓶精確稱量採取試樣約2 g，添加乙醯化試劑5 mL及吡啶10 mL，安裝空氣冷卻管。 (2)將上述燒瓶於100℃之浴中加熱70分鐘後，放置冷卻，自冷卻管之上部添加作為溶劑之甲苯35 mL並攪拌後，添加蒸餾水1 mL並攪拌，藉此將乙酸酐分解。為了完全分解，再次於浴中加熱10分鐘，進行放置冷卻。 (3)利用乙醇5 mL清洗冷卻管並取出。繼而，添加作為溶劑之吡啶50 mL並攪拌。 (4)使用全移液管25 mL，添加0.5 mol/L氫氧化鉀乙醇溶液。 (5)利用0.5 mol/L氫氧化鉀乙醇溶液進行電位差滴定。將所獲得之滴定曲線之反曲點設為終點。 (6)空試驗係不放入試樣而進行上述(1)～(5)。 3.計算 根據以下式算出羥值。 羥值(mgKOH/g)＝［(B－C)×f×28.05］/S＋D 此處， B：空試驗所使用之0.5 mol/L氫氧化鉀乙醇溶液之量(mL)、 C：試樣所使用之0.5 mol/L氫氧化鉀乙醇溶液之量(mL)、 f：0.5 mol/L氫氧化鉀乙醇溶液之因子、 S：試樣之重量(g)、 D：酸值、 28.05：氫氧化鉀之分子量56.11之1/2。 作為低羥值樹脂及高羥值樹脂，可使用上述各種黏著賦予樹脂中具有該羥值者。低羥值樹脂及高羥值樹脂可分別單獨使用1種或將2種以上組合使用。例如，作為低羥值樹脂，可較佳採用羥值未達30 mgKOH/g之酚系黏著賦予樹脂。而且，例如，作為高羥值樹脂，可較佳採用羥值為30 mgKOH/g以上之酚系黏著賦予樹脂。其中，較佳為萜烯酚樹脂。萜烯酚樹脂可根據酚之共聚合比率，將羥值任意控制，故而較佳。 (其他添加劑) 黏著劑組合物除上述各成分以外，可視需要包含調平劑、交聯助劑、塑化劑、軟化劑、抗靜電劑、抗老化劑、紫外線吸收劑、抗氧化劑、光穩定劑等黏著劑領域中通常之各種添加劑。關於此種各種添加劑，可利用常法使用先前公知者，尤其並非對本發明附特徵者，因此省略詳細之說明。 此處所揭示之黏著劑層可為由水系黏著劑組合物、溶劑型黏著劑組合物、熱熔型黏著劑組合物、活性能量線硬化型黏著劑組合物形成之黏著劑層。所謂水系黏著劑組合物係指於以水作為主成分之溶劑(水系溶劑)中包含黏著劑(黏著劑層形成成分)之形態的黏著劑組合物，典型而言，包含稱為水分散型黏著劑組合物(黏著劑之至少一部分分散於水中之形態的組合物)等者。而且，所謂溶劑型黏著劑組合物係指有機溶劑中包含黏著劑之形態的黏著劑組合物。此處所揭示之技術，就黏著特性等觀點而言，尤其可較佳以具備由溶劑型黏著劑組合物形成之黏著劑層的態樣而實施。 此處所揭示之黏著劑層可利用先前公知之方法而形成。例如，可採用於非剝離性基材直接賦予(典型而言為塗佈)黏著劑組合物並使其乾燥，藉此形成黏著劑層之方法(直接法)。而且，可採用於具有剝離性之表面(剝離面)賦予黏著劑組合物並使其乾燥，藉此於該表面上形成黏著劑層，將該黏著劑層轉印於非剝離性基材之方法(轉印法)。就生產性之觀點而言，較佳為轉印法。作為上述剝離面，可利用剝離襯墊之表面、或經剝離處理之基材背面等。再者，此處所揭示之黏著劑層典型而言為連續性形成，但並不限定於此種形態，例如可形成為點狀、條紋狀等規則性或無規圖案之黏著劑層。 黏著劑組合物之塗佈例如可使用凹版輥式塗佈機、模嘴塗佈機、棒式塗佈機等先前公知之塗佈機而進行。或者，可利用含浸或淋幕式塗佈法等而塗佈黏著劑組合物。 就促進交聯反應、提高製造效率等觀點而言，較佳為黏著劑組合物之乾燥係於加熱下進行。乾燥溫度例如可設為40～150℃左右，通常較佳為60～130℃左右。使黏著劑組合物乾燥後，進而，可以調整黏著劑層內的成分移行、交聯反應進行、緩和可存在於基材膜或黏著劑層內之變形等為目的，進行老化。 黏著劑層之厚度並無特別限制。就避免黏著片材過度增厚之觀點而言，黏著劑層之厚度通常大致100 μm以下較為適當，較佳為大致70 μm以下，更佳為大致50 μm以下，進而較佳為大致30 μm以下。較佳之一態樣之黏著片材中，黏著劑層之厚度大致25 μm以下(通常未達25 μm、較佳為大致22 μm以下、例如大致20 μm以下)。如此黏著劑層之厚度相對較小之黏著片材中，由於該黏著片材之單位面積之黏著劑量較少，故而將黏著劑層之油酸滲透量設為特定以上尤其有效果。黏著劑層之厚度之下限並無特別限制，就對被接著體之密接性之觀點而言，大致4 μm以上較為有利，較佳為大致6 μm以上、更佳為大致10 μm以上(例如大致15 μm以上)。 此處所揭示之技術例如可較佳以具備厚度大致10 μm以上且大致25 μm以下(較佳為大致15 μm以上且大致22 μm以下)之黏著劑層的黏著片材之形態而實施。較佳為於基材之雙面具有該厚度之黏著劑層的黏著片材。 (凝膠分率) 並無特別限定，但此處所揭示之黏著劑層之凝膠分率可以重量基準計，例如設為20%以上，通常設為30%以上較為適當，較佳為35%以上。藉由以適度之範圍提高黏著劑層之凝膠分率，有容易實現此處所揭示之適當之油酸滲透量的傾向。另一方面，若凝膠分率過高，則可能容易引起油酸滲透量不足。就該觀點而言，黏著劑層之凝膠分率較佳為90%以下，更佳為80%以下，進而較佳為70%以下(例如65%以下)。 此處所謂「黏著劑層之凝膠分率」係指利用如下方法而測定之值。該凝膠分率可以黏著劑層中乙酸乙酯不溶成分之重量比率而把握。 ［凝膠分率測定方法］ 將約0.1 g之黏著劑樣品(重量Wg1 )於平均孔徑0.2 μm之多孔質聚四氟乙烯膜(重量Wg2 )包成荷包狀，利用風箏線(重量Wg3 )紮住口。作為上述多孔質聚四氟乙烯(PTFE)膜，使用可自日東電工股份有限公司獲取之商品名「Nittoflon(註冊商標)NTF1122」(平均孔徑0.2 μm、氣孔率75%、厚度85 μm)或其相當品。將該包裹浸入至乙酸乙酯50 mL中，於室溫(典型而言為23℃)下保持7天時間，僅使黏著劑層中之溶膠成分溶出於上述膜外後，將上述包裹取出，拭去外表面附著之乙酸乙酯，使包裹於130℃下乾燥2小時，測定該包裹之重量(Wg4 )。黏著劑層之凝膠分率FG 係藉由將各值代入至以下式而求出。下述實施例中亦採用同樣之方法。 凝膠分率FG (%)＝［(Wg4 －Wg2 －Wg3 )/Wg1 ］×100 ＜基材＞ 於此處所揭示之黏著片材為單面黏著型或雙面黏著型附基材之黏著片材之形態的態樣中，作為支持(襯底)黏著劑層之基材，可使用樹脂膜、紙、布、橡膠片材、發泡體片材、金屬箔、該等之複合體等。作為樹脂膜之例，可列舉：聚乙烯(PE)、聚丙烯(PP)、乙烯・丙烯共聚物等聚烯烴製膜；聚對苯二甲酸乙二酯(PET)等聚酯膜；氯乙烯樹脂膜；乙酸乙烯酯樹脂膜；聚醯亞胺樹脂膜；聚醯胺樹脂膜；氟樹脂膜；塞璐芬等。作為紙之例，可列舉：日本紙、牛皮紙、玻璃紙、道林紙、合成紙、面漆紙等。作為布之例，可列舉：各種纖維狀物質之單獨或混紡等獲得之織布或不織布等。作為上述纖維狀物質，可例示：棉、人造短纖維、馬尼拉麻、紙漿、嫘縈、乙酸纖維、聚酯纖維、聚乙烯醇纖維、聚醯胺纖維、聚烯烴纖維等。作為橡膠片材之例，可列舉：天然橡膠片材、丁基橡膠片材等。作為發泡體片材之例，可列舉：發泡聚胺基甲酸酯片材、發泡聚氯戊二烯橡膠片材等。作為金屬箔之例，可列舉：鋁箔、銅箔等。 再者，此處所謂不織布，係主要指黏著帶及其他黏著片材之領域使用之黏著片材用不織布的概念，典型而言，係使用一般之抄紙機製作之不織布(亦有時稱為所謂「紙」)。而且，此處所謂之樹脂膜係典型而言非多孔質之樹脂片材，例如與不織布區別之(即，不包含不織布)概念。上述樹脂膜可為無延伸膜、一軸延伸膜、二軸延伸膜之任一者。而且，可於該基材之設置黏著劑層之面實施底塗劑之塗佈、電暈放電處理、電漿處理等表面處理。 此處所揭示之技術可較佳以於基材膜(支持體)之至少一個表面具有上述黏著劑層之形態的附基材之黏著片材的形態而實施。例如，可以於基材膜之一個表面及另一表面具有上述黏著劑層之附基材之雙面黏著片材的形態而實施。 作為基材膜，可較佳使用包含樹脂膜作為基礎膜者。上述基礎膜典型而言係獨立可維持形狀之(非依存性)構件。此處所揭示之技術中之基材膜可由此種基礎膜實質構成者。或者，上述基材膜除上述基礎膜外可包含輔助性之層。作為上述輔助性之層之例，可列舉設置於上述基礎膜之表面的底塗層、抗靜電層、著色層等。 上述樹脂膜係以樹脂材料作為主成分(該樹脂膜中包含超過50重量%之成分)之膜。作為樹脂膜之例，可列舉：聚乙烯(PE)、聚丙烯(PP)、乙烯・丙烯共聚物等聚烯烴系樹脂膜；聚對苯二甲酸乙二酯(PET)、聚對苯二甲酸丁二酯(PBT)、聚萘二甲酸乙二酯(PEN)等聚酯系樹脂膜；氯乙烯系樹脂膜；乙酸乙烯酯系樹脂膜；聚醯亞胺系樹脂膜；聚醯胺系樹脂膜；氟樹脂膜；塞璐芬；等。樹脂膜可為天然橡膠膜、丁基橡膠膜等橡膠系膜。其中，就操作性、加工性之觀點而言，較佳為聚酯膜，其中尤其較佳為PET膜。再者，本說明書中所謂「樹脂膜」，典型而言為非多孔質之片材且與所謂不織布或織布區別之概念(換言之，不織布或織布除外之概念)。 上述樹脂膜(例如PET膜)中可視需要調配填充劑(無機填充劑、有機填充劑等)、著色劑、分散劑(界面活性劑等)、抗老化劑、抗氧化劑、紫外線吸收劑、抗靜電劑、潤滑劑、塑化劑等各種添加劑。各種添加劑之調配比率通常為大致未達30重量%(例如大致未達20重量%、較佳為大致未達10重量%)左右。 上述樹脂膜可為具有單層構造，亦可為具有2層、3層或其以上之多層構造者。就形狀穩定性之觀點而言，樹脂膜較佳為單層構造。於多層構造之情形時，至少一層(較佳為全部層)較佳為具有上述樹脂(例如聚酯系樹脂)之連續構造之層。樹脂膜之製造方法只要適當採用先前公知之方法即可，並無特別限定。例如可適當採用擠出成形、膨脹成形、T壓鑄成形、砑光輥成形等先前公知之一般的膜成形方法。 此處所揭示之基材膜之厚度並無特別限定。就避免黏著片材過度增厚之觀點而言，基材膜之厚度例如可設為大致200 μm以下、較佳為大致150 μm以下、更佳為大致100 μm以下。根據黏著片材之使用目的或使用態樣，基材膜之厚度可為大致70 μm以下，可為大致50 μm以下，可為大致30 μm以下(例如大致25 μm以下)。於一態樣中，基材膜之厚度可為大致20 μm以下，可為大致15 μm以下，可為大致10 μm以下(例如大致5 μm以下)。藉由縮小基材膜之厚度，即便黏著片材之總厚度相同，亦可增大黏著劑層之厚度。此就提高與基材之密接性之觀點而言，可較為有利。基材膜之厚度之下限並無特別限制。就黏著片材之處理性(操作性)或加工性等觀點而言，基材膜之厚度通常為大致0.5 μm以上(例如1 μm以上)、較佳為大致2 μm以上、例如大致4 μm以上。於一態樣中，基材膜之厚度可為大致6 μm以上，可為大致8 μm以上，可為大致10 μm以上(例如超過10 μm)。 可於基材膜之表面實施電暈放電處理、電漿處理、紫外線照射處理、酸處理、鹼處理、底塗劑之塗佈等先前公知之表面處理。此種表面處理可為提高基材膜與黏著劑層之密接性、換言之黏著劑層與基材膜之抓固性的處理。 ＜剝離襯墊＞ 此處所揭示之技術中，可於黏著劑層形成、黏著片材製作、使用前之黏著片材之保存、流通、形狀加工等時，使用剝離襯墊。作為剝離襯墊，並無特別限定，例如可使用於樹脂膜或紙等襯墊基材之表面具有剝離處理層之剝離襯墊、或包含氟系聚合物(聚四氟乙烯等)或聚烯烴系樹脂(聚乙烯、聚丙烯等)之低接著性材料的剝離襯墊等。上述剝離處理層例如可為利用聚矽氧系、長鏈烷基系、氟系、硫化鉬等剝離處理劑對上述襯墊基材進行表面處理而形成者。 ＜黏著片材＞ 此處所揭示之黏著片材(不含剝離襯墊)之總厚度並無特別限定。黏著片材之總厚度例如可設為大致500 μm以下，通常大致350 μm以下較為適當，較佳為大致250 μm以下(例如大致200 μm以下)。此處所揭示之技術可以總厚度大致150 μm以下(更佳為大致100 μm以下、進而較佳為大致未達60μm、例如大致55μm以下)之黏著片材(典型而言為雙面黏著片材)之形態而實施。黏著片材之厚度之下限並無特別限定，通常大致10 μm以上較為適當，較佳為大致20 μm以上，更佳為大致30 μm以上。 根據此處所揭示之技術，可提供一種以下耐油黏著性評價中黏著力維持率超過50%之黏著片材。於較佳之一態樣之黏著片材中，上述黏著力維持率可為60%以上(例如65%以上)。黏著力維持率之上限並無特別限定，通常為150%以下，較佳為100%以下。 ［耐油黏著性評價］ 將黏著片材切割成寬度10 mm、長度100 mm之尺寸，調製試樣片。此處，於測定態樣之黏著片材為雙面黏著片材之情形時，於一個黏著面貼附厚度50 μm之PET膜襯底後，切割成上述尺寸。 於23℃、50%RH之環境下，將上述試樣片之黏著面壓接於不鏽鋼板(SUS304BA板)而製作測定樣品。上述壓接係藉由使2 kg之滾筒往返1次而進行。將上述測定樣品於23℃、50%RH之環境下放置30分鐘後，使用拉伸試驗機，根據JIS Z0237：2000，以拉伸速度150 mm/分鐘、剝離角度180度之條件，測定剝離強度(N/10 mm)。將該值設為浸漬前黏著力。 另一方面，將與上述同樣製作之測定樣品於23℃、50%RH之環境下放置30分鐘後，浸漬於油酸浴，於40℃、90%RH之環境下保持2週。其後，將上述測定樣品自油酸浴提起，輕輕拭去附著於周圍之油酸，於23℃、50%RH之環境下放置30分鐘後，以與上述浸漬前黏著力同樣之方式測定剝離強度(N/10 mm)。將該值設為浸漬後黏著力。 根據所獲得之測定值，利用以下式： 黏著力維持率(%)＝(浸漬後黏著力/浸漬前黏著力)×100； 而算出黏著力維持率。 再者，作為拉伸試驗機，例如可使用島津製造作所公司製造之「精密萬能試驗機 自動立體測繪儀AG-IS50N」。下述實施例中亦採用同樣之評價方法。 此處所揭示之黏著片材中，上述浸漬前黏著力並無特別限定。較佳之一態樣之黏著片材之浸漬前黏著力大致為3.0 N/10 mm以上。顯示此種浸漬前黏著力之黏著片材對被接著體之密接性較高，因此可成為防止油分自黏著片材之外邊緣浸入至接著界面之性能優異者。更佳為浸漬前黏著力大致5.0 N/10 mm以上(例如大致6.0 N/10 mm以上)之黏著片材。只要對被接著體之密接性越高則越佳，因此浸漬前黏著力之上限並無特別限制，通常大致30 N/10 mm以下(例如大致20 N/10 mm以下)較為適當。 並無特別限定，上述浸漬後黏著力就抑制黏著劑溢出之觀點而言，較佳為1.0 N/10 mm以上。上述浸漬後黏著力較佳為大致2.0 N/10 mm以上、更佳為大致3.0 N/10 mm以上、進而較佳為大致4.0 N/10 mm以上(例如大致5.0 N/10mm以上、進而大致6.0 N/10 mm以上)。顯示此種浸漬後黏著力之黏著片材例如較佳用於固定可接觸於油分之構件的用途等。 ＜用途＞ 此處所揭示之黏著片材即便與油分接觸，黏著力之降低亦較少且抑制黏著劑之溢出。活用此種特徵，上述黏著片材可較佳用於固定可與油分接觸之各種構件的用途。作為此種用途之代表例，可列舉於各種行動裝置(可攜式設備)中固定構件之用途。例如較佳用於可攜式電子機器中之構件之固定用途。上述可攜式電子機器之非限定例包含行動電話、智慧型手機、平板型電腦、筆記型電腦、各種可佩戴設備(例如，包含如手錶般佩戴於手腕之戴手腕型、夾子或掛繩等佩戴於身體之一部分的模組型、眼鏡型(單眼型或雙眼型。亦包含頭戴型)之眼睛防護型、於襯衫或襪子、帽子等例如以飾品之形態佩戴之衣服型、如耳機般之佩戴於耳之耳朵防護型等)、數位相機、數位攝錄影機、音響設備(隨身聽、IC記錄器等)、計算機(計算器等)、可攜遊戲設備、電子詞典、電子記事本、電子書籍、車載用資訊設備、可攜廣播、可攜電視、可攜印表機、可攜掃描儀、可攜數據機等。可攜式電子機器以外之行動裝置之非限定例包含機械式手錶或懷錶、手電筒、掌上鏡、月票夾等。再者，本說明書中所謂「可攜」僅能可攜並不充分，意指具有個人(標準成人)可相對容易裝運之程度的可攜性。 此處所揭示之黏著片材(典型而言為雙面黏著片材)可以加工成各種外形之接合材的形態用於固定構成行動裝置之構件。作為尤其較佳之用途，可列舉固定構成可攜式電子機器之構件的用途。其中，可較佳用於具有液晶顯示裝置之可攜式電子機器。例如，此種可攜式電子機器中較佳用於將顯示部(可為液晶顯示裝置之顯示部)或顯示部保護構件與筐體接合之用途等。 作為此種接合材之較佳之形態，可列舉具有寬度4.0 mm以下(例如2.0 mm以下、通常未達2.0 mm)之細幅部的形態。此處所揭示之黏著片材除耐油性外，凝聚力亦優異，因此即便用作包含此種細幅部之形狀(例如框狀)的接合材，亦可良好固定構件。於一態樣中，上述細幅部之寬度可為1.5 mm以下，亦可為1.0 mm以下，可為0.5 mm左右或其以下。細幅部之寬度之下限並無特別限制，就黏著片材之操作性之觀點而言，通常0.1 mm以上(例如0.2 mm以上)較為適當。 上述細幅部典型而言為線狀。此處所謂線狀係除直線狀、曲線狀、摺線狀(例如L字型)等外，包含框狀或圓狀等環狀、或該等之複合或中間形狀之概念。所謂上述環狀並不限定於由曲線構成者，如例如沿四角形之外周之形狀(框狀)或沿扇型之外周的形狀般，係包含一部分或全部形成為直線狀之環狀的概念。上述細幅部之長度並無特別限定。例如，上述細幅部之長度為10 mm以上(更佳為20 mm以上，例如30 mm以上)之形態中，可較佳發揮應用此處所揭示之技術的效果。 由本說明書揭示之事項包含以下者。 (1)一種黏著片材，其係具備由以丙烯酸系聚合物作為基礎聚合物之黏著劑構成之黏著劑層者，且 上述黏著劑層之表面自由能量γ大致未達40 mJ/m2 ，且油酸滲透量大致1.5 g以上且大致5.0 g以下。 (2)如上述(1)之黏著片材，其中上述黏著劑層之凝膠分率大致30%以上且大致70%以下。 (3)如上述(1)或(2)之黏著片材，其中上述黏著劑層係使用包含上述丙烯酸系聚合物及交聯劑之黏著劑組合物而形成。 (4)如上述(3)之黏著片材，其中上述交聯劑包含異氰酸酯系交聯劑。 (5)如上述(1)至(4)中任一項之黏著片材，其中上述黏著劑層包含黏著賦予樹脂，該黏著賦予樹脂之大致50重量%以上為松香系樹脂以外之黏著賦予樹脂。 (6)如上述(1)至(5)中任一項之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含大致多於50重量%之(甲基)丙烯酸烷基C7-10 酯。 (7)如上述(6)之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含大致多於5重量%之含羧基之單體。 (8)如上述(1)至(7)中任一項之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含大致70重量%以上之(甲基)丙烯酸C7-10 烷基酯、及大致7重量%以上且大致15重量%以下之含羧基之單體。 (9)如上述(8)之黏著片材，其中上述(甲基)丙烯酸C7-10 烷基酯係選自丙烯酸2-乙基己酯、丙烯酸異辛酯及丙烯酸異壬酯中之1種或2種以上，上述含羧基之單體為丙烯酸、甲基丙烯酸或該等之組合。 (10)如上述(6)至(9)中任一項之黏著片材，其中上述黏著劑層包含黏著賦予樹脂，該黏著賦予樹脂之大致50重量%以上為酚系黏著賦予樹脂(例如萜烯酚樹脂)。 (11)如上述(10)之黏著片材，其中上述酚系黏著賦予樹脂包含羥值大致未達30 mgKOH/g之萜烯酚樹脂。 (12)如上述(1)至(5)中任一項之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含大致多於50重量%之(甲基)丙烯酸C1-6 烷基酯。 (13)如上述(12)之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含大致多於3重量%之含羧基之單體。 (14)如上述(13)之黏著片材，其中上述(甲基)丙烯酸C1-6 烷基酯係選自丙烯酸正丁酯、丙烯酸乙酯及丙烯酸甲酯中之1種或2種以上，上述含羧基之單體為丙烯酸、甲基丙烯酸或該等之組合。 (15)如上述(12)至(14)中任一項之黏著片材，其中上述黏著劑層包含黏著賦予樹脂，該黏著賦予樹脂之大致50重量%以上為酚系黏著賦予樹脂(例如萜烯酚樹脂)。 (16)如上述(15)之黏著片材，其中上述酚系黏著賦予樹脂包含羥值大致30 mgKOH/g以上之萜烯酚樹脂。 (17)如上述(1)至(16)中任一項之黏著片材，其中上述黏著劑層係使用於有機溶劑中包含黏著劑之溶劑型黏著劑組合物而形成。 (18)如上述(17)之黏著片材，其中上述有機溶劑包含甲苯及乙酸乙酯之至少一者。 (19)如上述(1)至(18)中任一項之黏著片材，其中上述黏著劑層之厚度大致10 μm以上且25 μm以下。 (20)如上述(1)至(19)中任一項之黏著片材，其中以於基材之一個表面及另一個表面具有上述黏著劑層之雙面黏著片材而構成。 (21)如上述(20)之黏著片材，其中上述基材為單層構造之PET膜。 (22)如上述(1)至(21)中任一項之黏著片材，其用於行動裝置中構件之固定。 (23)一種行動裝置，其具有使用如上述(1)至(22)中任一項之黏著片材而固定之構件。 (24)如上述(23)之行動裝置，其中上述行動裝置為可佩戴設備(例如戴手腕型可佩戴設備)。 [實施例] 以下，說明與本發明有關之幾個實施例，但並非意指將本發明限定於該實施例。再者，以下之說明中「份」及「%」只要無特別說明，則為重量基準。 ＜丙烯酸系聚合物溶液之調製＞ (丙烯酸系聚合物A) 於具備攪拌機、溫度計、氮氣導入管、回流冷卻器及滴加漏斗之反應容器中添加作為單體成分之2EHA 90份及AA 10份、作為聚合溶劑之乙酸乙酯199份，一面導入氮氣一面攪拌2小時。以如此方式，將聚合體系內之氧除去後，添加作為聚合起始劑之0.2份之過氧化苯甲醯，於60℃下進行溶液聚合6小時，獲得丙烯酸系聚合物A之溶液。該丙烯酸系聚合物A之Mw約為120×104 。 (丙烯酸系聚合物B) 於具備攪拌機、溫度計、氮氣導入管、回流冷卻器及滴加漏斗之反應容器中添加作為單體成分之2EHA 100份、甲基丙烯酸甲酯(MMA)2份及AA 2份、作為聚合溶劑之甲苯190份，一面導入氮氣一面攪拌2小時。以如此方式，除去聚合體系內之氧後，添加作為聚合起始劑之0.3份之2,2'-偶氮雙異丁腈，於60℃下進行6小時溶液聚合，獲得丙烯酸系聚合物B之溶液。該丙烯酸系聚合物B之Mw約為100×104 。 (丙烯酸系聚合物C) 於具備攪拌機、溫度計、氮氣導入管、回流冷卻器及滴加漏斗之反應容器中添加作為單體成分之BA 95份及AA 5份、及作為聚合溶劑之乙酸乙酯233份，一面導入氮氣一面攪拌2小時。以如此方式，除去聚合體系內之氧後，添加作為聚合起始劑之0.2份之2,2'-偶氮雙異丁腈，於60℃下進行8小時溶液聚合，獲得丙烯酸系聚合物之溶液。該丙烯酸系聚合物之Mw約為70×104 。 ＜黏著劑組合物之製作＞ (例1) 於上述丙烯酸系聚合物A之溶液，相對於該溶液中所含丙烯酸系聚合物A之100份，添加2份(不揮發成分基準。以下相同)之異氰酸酯系交聯劑(商品名「Coronate L」，三羥甲基丙烷/甲伸苯基二異氰酸酯3聚物加成物之75%乙酸乙酯溶液，東曹公司製造；以下稱為「異氰酸酯系交聯劑A」)，進行攪拌混合，調製本例之黏著劑組合物。 (例2) 於上述丙烯酸系聚合物A之溶液，相對於該溶液所含之丙烯酸系聚合物A之100份，添加2份異氰酸酯系交聯劑A、0.01份環氧系交聯劑(商品名「TETRAD-C」、及1,3-雙(N,N-二縮水甘油基胺基甲基)環己烷，三菱瓦斯化學公司製造；以下稱為「環氧系交聯劑B」)，進行攪拌混合，調製本例之黏著劑組合物。 (例3) 於上述丙烯酸系聚合物A之溶液，相對於該溶液所含之丙烯酸系聚合物A之100部，添加2份異氰酸酯系交聯劑A、0.035份環氧系交聯劑B、及10份萜烯酚樹脂A(商品名「Tamanol 803L」，荒川化學工業公司製造，軟化點約145～160℃，羥值1～20 mgKOH/g)，進行攪拌混合，調製本例之黏著劑組合物。 (例4) 於上述丙烯酸系聚合物C之溶液，相對於該溶液所含之丙烯酸系聚合物C之100份，添加2份異氰酸酯系交聯劑A，進行攪拌混合，調製本例之黏著劑組合物。 (例5) 除相對於丙烯酸系聚合物C之100份，進而添加30份萜烯酚樹脂B(安原化學公司製造，商品名「YS Polystar第二145」，軟化點約145℃，羥值70～110mgKOH/g)以外，以與例4同樣之方式，調製本例之黏著劑組合物。 (例6) 除將相對於丙烯酸系聚合物C 100份之萜烯酚樹脂B之使用量變更為40份以外，以與例5同樣之方式，調製本例之黏著劑組合物。 (例7) 於上述丙烯酸系聚合物B之溶液，相對於該溶液所含之丙烯酸系聚合物B之100份，添加2份異氰酸酯系交聯劑A，進行攪拌混合，調製本例之黏著劑組合物。 (例8) 除將相對於丙烯酸系聚合物C 100份之異氰酸酯系交聯劑A的使用量變更為1份以外，以與例4同樣之方式，調製本例之黏著劑組合物。 (例9) 除相對於丙烯酸系聚合物C之100份，進而添加10份松香系黏著賦予樹脂A(商品名「Halitac SE10」，氫化松香甘油酯，哈利瑪化成公司製造，軟化點約80℃)以外，以與例4同樣之方式，調製本例之黏著劑組合物。 (例10) 於上述丙烯酸系聚合物C之溶液，相對於該溶液所含之丙烯酸系聚合物C之100份，添加2份異氰酸酯系交聯劑A、0.01份環氧系交聯劑B、20份松香系黏著賦予樹脂B(商品名「PENSEL D125」，荒川化學工業公司製造，聚合松香之季戊四醇酯，軟化點約125℃)，進行攪拌混合，調製本例之黏著劑組合物。 ＜黏著片材之製作＞ 作為剝離襯墊，準備2片單面成為經剝離處理之剝離面的聚酯製剝離膜(商品名「DIAFOIL MRF」，厚度38 μm，三菱聚酯公司製造)。於該等剝離襯墊之剝離面塗佈各例之黏著劑組合物，於100℃下使其乾燥2分鐘，形成厚度19 μm之黏著劑層。將上述2片剝離襯墊上形成之黏著劑層分別貼合於厚度12 μm之透明基材膜的第1面及第2面，製作總厚50 μm之雙面黏著片材。上述剝離襯墊直接殘留於黏著劑層上，用於保護黏著劑層之表面(接著面)。作為基材膜，使用東麗公司製造之PET膜(樹脂膜)，商品名「Lumirror」。以如此方式，製作分別對應於例1～10之黏著劑組合物的例1～10之雙面黏著片材。 ＜評價試驗＞ 將例1～10之雙面黏著片材於50℃、50%RH之環境下固化1日後，利用上述方法，求出表面自由能量γ、凝膠分率及黏著力維持率。 而且，於上述聚酯製剝離膜(商品名「DIAFOIL MRF」，厚度38 μm，三菱聚酯公司製造)之剝離面塗佈例1～10之黏著劑組合物，於120℃下使其乾燥2分鐘，於該剝離膜上形成厚度20 μm之黏著劑層(無基材黏著劑層)。將該黏著劑層貼合於厚度50 μm之PET膜(商品名「Lumirror」，東麗公司製造)，切割成縱25 mm、橫25 mm之正方形狀，製作試驗片。使用該試驗片，利用上述方法進行油酸滲透性評價，藉此求出油酸滲透量及滲透距離，評價黏著劑之溢出。 所獲得之結果示於表1、2。 [表1] [表2] 如表1、2所示，具備表面自由能量γ未達40 mJ/m2 ，且油酸滲透量為1.5g/g以上且5.0 g/g以下之範圍的黏著劑層之例1～6的黏著片材任一顯示良好之黏著力維持率，黏著劑之溢出亦較少。另一方面，油酸滲透量過少之例7、8及表面自由能量γ過高之例10中，黏著力維持率較低。油酸滲透量過多之例9中，黏著劑之溢出較大。 以上，詳細說明本發明之具體例，但該等僅為例示，並非限定申請專利範圍。申請專利範圍記載之技術包含將以上例示之具體例進行各種變形、變更者。Hereinafter, preferred embodiments of the present invention will be described. Further, in the case of the present invention, which is not specifically mentioned in the present specification, and the necessity of the present invention, those skilled in the art can understand the teachings of the invention described in the specification and the technical common sense at the time of application. The present invention can be implemented based on the contents disclosed in the present specification and the technical common sense in the field. In the following drawings, members and portions that perform the same functions are denoted by the same reference numerals, and overlapping descriptions may be omitted or simplified. Further, the embodiments described in the drawings are modeled to clearly illustrate the present invention, and do not accurately represent the size or scale of the adhesive sheet of the present invention actually provided as a product. In the present specification, the term "adhesive" as used herein refers to a material which has a soft solid (viscoelastic body) in a temperature region near room temperature and which is simply followed by the nature of the adherend by pressure. The so-called adhesive herein, as defined in "CA Dahlquist, "Adhesion: Fundamentals and Practice", McLaren & Sons, (1966) P.143", generally has a complex tensile modulus E. * (1Hz)<10 7 Dyne/cm 2 A material of the nature (typically a material having the above properties at 25 ° C). In the present specification, the term "(meth)acrylonitrile" means acryloyl group and methacryl fluorenyl group. Similarly, "(meth)acrylate" means acrylate and methacrylate, and "(meth)acrylic" means acrylic acid and methacrylic acid. In the present specification, the "acrylic polymer" is a polymer containing a monomer unit derived from a monomer having at least one (meth)acryl fluorenyl group in one molecule, as a monomer constituting the polymer. unit,. Hereinafter, a monomer having at least one (meth) acrylonitrile group in one molecule is also referred to as an "acrylic monomer". The acrylic polymer in the present specification is defined as a polymer containing a monomer unit derived from an acrylic monomer. The adhesive sheet disclosed herein has an adhesive layer composed of an adhesive having an acrylic polymer as a base polymer. Here, the term "base polymer" means a main component of a rubber-like polymer (a polymer region showing a rubber elasticity in a temperature region near room temperature) contained in the pressure-sensitive adhesive layer. In the present specification, the term "main component" means a component contained in an amount exceeding 50% by weight unless otherwise specified. The adhesive sheet disclosed herein may be an adhesive sheet attached to the substrate in the form of the above-mentioned adhesive layer on one or both sides of the substrate (support), and the adhesive layer may be held in the release liner. A non-substrate adhesive sheet such as a form. The term "adhesive sheet" as used herein may include an adhesive tape, an adhesive label, an adhesive film, and the like. Furthermore, the adhesive sheet disclosed herein may be in the form of a roll or a single piece. Alternatively, it may be an adhesive sheet which is further processed into various shapes. The adhesive sheet disclosed herein may be, for example, a cross-sectional structure having a pattern as schematically illustrated in FIGS. 1 to 6. 1 and 2 are structural examples of an adhesive sheet with a double-sided adhesive type attached to a substrate. The adhesive sheet 1 shown in Fig. 1 has adhesive layers 21 and 22 which are respectively disposed on the respective faces of the substrate 10 (any of which is non-releasable), and the adhesive layers are formed as a release surface by at least the adhesive layer side. The release liners 31 and 32 are respectively protected. The adhesive sheet 2 shown in Fig. 2 is provided with adhesive layers 21, 22 on each side of the substrate 10 (any of which is non-releasable), and one of the adhesive layers 21 is made of a double-sided peeling surface. The structure is protected by peeling off the liner 31. The adhesive sheet 2 can be formed by winding the adhesive sheet and abutting the other adhesive layer 22 against the back surface of the release liner 31, whereby the adhesive layer 22 is also protected by the release liner 31. 3 and 4 show a configuration example of a double-sided adhesive sheet having no substrate. The adhesive sheet 3 shown in Fig. 3 has a configuration in which the double-sided sheets 21A and 21B of the substrate-free adhesive layer 21 are respectively protected by the release liners 31 and 32 which are at least the adhesive layer side as the release surface. The adhesive sheet 4 shown in Fig. 4 has a structure in which one surface (adhesive surface) 21A of the adhesive-free layer 21 is protected by a release liner 31 which is a release surface on both sides, and if it is wound, it can be adhered. The other surface (adhesive surface) 21B of the agent layer 21 abuts against the back surface of the release liner 31, whereby the other surface 21B is also protected by the release liner 31. Fig. 5 and Fig. 6 show an example of the configuration of an adhesive sheet with a single-sided adhesive type attached to a substrate. The adhesive sheet 5 shown in Fig. 5 has an adhesive layer 21 provided on one surface 10A (non-releasable) of the substrate 10, and the surface (adhesive surface) 21A of the adhesive layer 21 is formed by at least the side of the adhesive layer. The structure of the release liner 31 is protected. The adhesive sheet 6 shown in Fig. 6 has a structure in which an adhesive layer 21 is provided on one surface 10A (non-releasable) of the substrate 10. The other surface 10B of the substrate 10 serves as a peeling surface. When the adhesive sheet 6 is wound, the adhesive layer 21 abuts against the other surface 10B, and the surface (adhesive surface) 21B of the adhesive layer is provided by the other surface 10B of the substrate. protection. <Adhesive layer> The adhesive sheet disclosed herein is characterized in that the surface free energy γ of the above adhesive layer is less than 40 mJ/m. 2 And the oleic acid permeation amount of the adhesive layer is 1.5 g/g or more and 5.0 g/g or less. (surface free energy γ) The surface free energy γ of the adhesive layer is of the following formula: γ = γ d +γ p +γ h ; the value expressed. Here, γ in the above formula d γ p And γ h The dispersion component, the polar component, and the hydrogen bonding component of the surface free energy are respectively indicated. The surface free energy γ of the adhesive layer can use water, diiodomethane and 1-bromonaphthalene as probe liquids, according to the contact angle of each probe liquid, according to the Kitasaki-畑 type (Japan Next Association, Vol.8, N0) .3, 1972, pp. 131-141). The measurement of the contact angle can be carried out using a commercially available contact angle meter. As the contact angle meter, the product name "CA-X" manufactured by Kyowa Interface Science Co., Ltd. can be used. The measurement method was carried out by using the droplet method, and the contact angle was measured from the shape of the droplet after the dropping of 1500 ms. The same method is also employed in the following examples. When the surface free energy γ of the adhesive layer is lowered, the wettability of the adherend layer to the adhesive layer is improved, and the adhesion between the adhesive layer and the interface (the interface) of the adherend tends to be improved. By increasing the adhesion of the subsequent interface, it is possible to suppress the oil from immersing into the above-mentioned interface from the outer edge of the adhesive sheet. If the surface free energy of the adhesive layer is further lowered in relation to the surface free energy of the adherend, the wettability of the adherend tends to be improved. Therefore, by further reducing the surface free energy γ of the adhesive layer, the adhesion to a specific adherend can be improved, and the adherend of a plurality of materials can be more closely adhered. From this point of view, the surface free energy γ of the adhesive layer is preferably approximately 35 mJ/m. 2 Below, more preferably about 30 mJ/m 2 the following. In one aspect, the surface free energy γ of the adhesive layer can be 27 mJ/m. 2 Below, it can also be 25 mJ/m 2 Hereinafter, it can be 20 mJ/m 2 the following. The lower limit of the surface free energy γ of the adhesive layer is not particularly limited, and is generally approximately 7 mJ/m. 2 Above, preferably about 10 mJ/m 2 the above. The surface free energy γ of the adhesive layer can be, for example, the composition of the monomer component constituting the acrylic polymer (the type of the main monomer and the sub-monomer used as needed, and the amount of use, etc.), the type of the adhesive-imparting resin, and Adjusted by the amount of use, etc. (Oleic Acid Penetration Amount) In the technique disclosed herein, the oleic acid permeation amount of the adhesive layer was measured by the following method. [Evaluation of oleic acid permeability] The adhesive layer to be measured is prepared to have a thickness of 20 on a non-peeling surface of a polyethylene terephthalate (PET) film having a thickness of about 10 μm to 100 μm (for example, 50 μm). The shape of the single-sided adhesive sheet of the above adhesive layer of μm. For example, the above-mentioned adhesive layer can be prepared by coating the non-peeling surface of the PET film on a suitable release surface in a form without a substrate, whereby the single-sided adhesive sheet can be prepared. The one-sided adhesive sheet was cut into a square shape of 25 mm in length and 25 mm in width to prepare a test piece. On the surface of the stainless steel plate (SUS304BA plate), at the center of the stainless steel plate, two marking lines intersecting at an angle of 90 degrees are drawn by an oil-based pen. The adhesive surface of the test piece was attached to a stainless steel plate on which the above-mentioned reticle was drawn in an environment of 23 ° C and 50% RH to prepare a measurement sample. At this time, the test piece was placed in such a manner that the center line of the longitudinal and lateral directions of the test piece was aligned with the above-mentioned line. The above measurement sample was kept in an environment of 23 ° C and 50% RH for 12 hours. Then, the weight of the measurement sample (weight before immersion) was measured, and the measurement sample was immersed in an oleic acid bath and kept in an environment of 40° C. and 90% RH for 2 weeks. Thereafter, the above-mentioned measurement sample was lifted from the oleic acid bath, and the surrounding oleic acid was lightly rubbed, and the weight of the measurement sample (weight after immersion) was measured. According to the obtained measured value, the following formula is used: oleic acid permeation amount = (weight after immersion - weight before immersion) / weight of the adhesive before permeation; calculation of oleic acid permeation amount per g of the adhesive layer (g/g) . In the examples below, the same evaluation method was also employed. The adhesive layer having an oleic acid penetration of 1.5 g/g or more showed better oil retention than the adhesive layer having less oleic acid penetration. Thereby, even if the oil is immersed from the outer edge of the adhesive sheet to the subsequent interface, the oil is absorbed by the layer (block) of the adhesive layer, whereby the subsequent interface can be maintained in a state of less oil. Thereby, the decrease in the adhesive force due to the oil component existing in the subsequent interface can be effectively suppressed. Further, the oil which is immersed in the outer edge of the adhesive sheet to the subsequent interface is absorbed by the block of the adhesive layer, and it is possible to suppress the above-mentioned oil component from proceeding along the inner surface of the range in which the adhesive sheet is adhered to the interface. That is, it is possible to suppress the penetration distance of the oil from the outer edge of the adhesive sheet. Thereby, the influence of the oil component from the outer edge to the inner side of the adhesive sheet is suppressed, and the adhesive force as the entire adhesive sheet can be more favorably maintained. Further, by appropriately absorbing the oil component by the block of the adhesive layer, the adhesive layer is softened, and the peeling strength can be enhanced by the deformation energy of the adhesive layer. This also advantageously helps to suppress the decrease in adhesion due to oil. In this way, by making it possible to suppress the oil from immersing into the subsequent interface from the outer edge of the adhesive sheet, and the immersed oil component is easily absorbed by the block of the adhesive layer from the subsequent interface, the adhesion due to the contact of the oil can be effectively suppressed. reduce. The oleic acid permeation amount of the adhesive layer is preferably about 1.6 g/g or more, and more preferably about 1.8 g/g or more, from the viewpoint of further exerting the above effects. The technique disclosed herein may preferably be carried out in such a manner that the oleic acid permeation amount of the adhesive layer is approximately 2.0 g/g or more (further, approximately 2.5 g/g or more, for example, approximately 3.0 g/g or more). The upper limit of the oleic acid penetration amount of the adhesive layer is preferably about 5.0 g/g or less, preferably about 4.5 g/g or less, from the viewpoint of excessive absorption of the oil by the adhesive layer and prevention of the overflow of the adhesive. For example, approximately 4.0 g/g or less). In a preferred aspect of the adhesive sheet, the oleic acid permeation amount of the adhesive layer may be, for example, approximately 1.6 g/g or more and approximately 4.5 g/g or less, more preferably approximately 1.8 g/g or more and approximately 4.5 g. /g below. The amount of oleic acid permeation of the adhesive layer can be, for example, based on the composition of the monomer component constituting the acrylic polymer (the following main monomer and the type and amount of the secondary monomer used as needed), and the acrylic polymer. The molecular weight, the type and amount of the crosslinking agent, the type and amount of the resin to be applied, and the amount of the resin to be used are adjusted. The evaluation of the overflow prevention property of the adhesive can also be carried out by the above evaluation of the oleic acid permeability. Specifically, in the above oleic acid permeability evaluation, immediately after the measurement sample was lifted from the oleic acid bath, the overflow distance (overflow width) of the adhesive from the outer edge of the PET film was visually measured. In the following examples, the same evaluation method was also employed. In a preferred aspect, the adhesive may have an overflow width of substantially less than 1.0 mm (preferably about 0.5 mm or less, and more preferably about 0.3 mm or less). An adhesive sheet having an adhesive layer having such an overflow prevention property is preferably used for the purpose of seeking bonding at a limited interval, for example, for use in a fixing member in a mobile device. The smaller the overflow width of the adhesive, the better, preferably about 0 mm. Further, according to the above oleic acid permeability evaluation, the penetration distance of oleic acid in the adhesive sheet can be measured. Specifically, the measurement sample is lifted from the oleic acid bath, and the oleic acid adhered to the periphery is gently wiped, and the length of the reticle on the stainless steel is measured from the outer edge of the PET film toward the inner side, and the length is set. It is the penetration distance of oleic acid. The same measurement method was also employed in the following examples. In a preferred embodiment, the permeation distance of the oleic acid is suitably about 0.5 mm or more, more preferably about 0.8 mm or more, and still more preferably about 1.0 mm or more. Further, the permeation distance of the oleic acid is preferably substantially 7.0 mm or less, more preferably approximately 5.0 mm or less, still more preferably approximately 4.0 mm or less (for example, approximately 1.0 mm or more and approximately 4.0 mm or less). The adhesive layer having a permeation distance of oleic acid in the above range has a tendency to better achieve the preferred oleic acid penetration amount disclosed herein. (Acrylic Polymer) The adhesive constituting the above adhesive layer contains an acrylic polymer as a base polymer. The acrylic polymer is preferably a polymer containing a (meth)acrylic acid alkyl ester as a main monomer and further comprising a monomer raw material of the main monomer and a copolymerizable sub-monomer. Here, the main single system means that more than 50% by weight of the components are contained in the above monomer raw material. As the alkyl (meth)acrylate, for example, a compound represented by the following formula (1) can be preferably used. CH 2 =C(R 1 )COOR 2 (1) Here, R in the above formula (1) 1 It is a hydrogen atom or a methyl group. And, R 2 It is a chain alkyl group having 1 to 20 carbon atoms (hereinafter, the range of such a carbon number may be expressed as "C" 1-20 "). From the viewpoint of the storage elastic modulus of the adhesive, etc., it is preferably R 2 For C 1-14 The alkyl (meth) acrylate of a chain alkyl group, more preferably R 2 For C 1-10 The alkyl (meth) acrylate of a chain alkyl group, particularly preferably R 2 It is an alkyl (meth)acrylate of butyl or 2-ethylhexyl. As R 2 For C 1-20 Examples of the alkyl (meth)acrylate of the chain alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and isopropyl (meth)acrylate. Ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, (methyl) Hexyl acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, Isodecyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, (A) Tridecyl acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, heptadecyl (meth) acrylate A base ester, octadecyl (meth)acrylate, a nonyl (meth)acrylate, an amyl (meth)acrylate, and the like. These alkyl (meth)acrylates may be used alone or in combination of two or more. As a particularly preferable (meth)acrylic acid alkyl ester, n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA) are mentioned. The technique disclosed herein preferably comprises at least one of BA and 2EHA as a monomer component constituting the acrylic polymer, and a total amount of BA and 2EHA in the alkyl (meth)acrylate contained in the monomer component. It is carried out in an amount of 75% by weight or more (usually 85% by weight or more, for example, 90% by weight or more, and further 95% by weight or more). The technique disclosed herein can be carried out, for example, by using an alkyl (meth)acrylate contained in the above monomer component in a state of BA alone, a state of 2EHA alone, a state including BA and 2EHA, and the like. When the monomer component contains BA and 2EHA, the weight ratio of BA to 2EHA (BA/2EHA) is not particularly limited, and may be, for example, 1/99 or more and 99/1 or less. In a preferred embodiment, the BA/2EHA may be 40/60 or less (for example, 1/99 or more and 40/60 or less), may be 20/80 or less, and may be 10/90 or less (for example, 1/99 or more and 10/90 or less). The technique disclosed herein preferably comprises more than 50% by weight of (meth)acrylic acid C as a monomer component constituting the above acrylic polymer. 7-10 It is carried out in the form of an alkyl ester. (meth)acrylic acid C 7-10 The acrylic polymer having an alkyl ester as a main monomer has a high affinity for oil. By utilizing the affinity of the oil, the oil which is immersed in the outer edge of the adhesive sheet to the subsequent interface is appropriately absorbed into the layer of the adhesive layer, whereby the adhesion due to contact with the oil can be effectively suppressed. (meth)acrylic acid C in the monomer component 7-10 The ratio of the alkyl ester may be 60% by weight or more, or may be 70% by weight or more (for example, 80% by weight or more, and further preferably 85% by weight or more). (meth)acrylic acid C in the monomer component 7-10 The upper limit of the ratio of the alkyl ester is not particularly limited and may be, for example, less than 98% by weight. It is usually easy to combine the (meth)acrylic acid C in the monomer component from the viewpoint of other characteristics. 7-10 The ratio of the alkyl ester is suitably 97% by weight or less, preferably 95% by weight or less (generally less than 95% by weight, for example, 93% by weight or less). (meth)acrylic acid C 7-10 The alkyl esters may be used alone or in combination of two or more. As (meth)acrylic acid C 7-10 Preferred examples of the alkyl ester include acrylic acid C such as 2EHA, isooctyl acrylate or isodecyl acrylate. 7-10 Alkyl ester. Among them, 2EHA is preferred. The technique disclosed herein may preferably further comprise (meth)acrylic acid C as a monomer component constituting the above acrylic polymer. 1-6 The alkyl ester is carried out in an amount of more than 50% by weight. (meth)acrylic acid C 1-6 When the alkyl ester is used as the base polymer, the acrylic polymer may be used as a base polymer, for example, the type and amount of the secondary monomer, the type and amount of the crosslinking agent, and the type and amount of the resin to be adhered to. The conditions are appropriately set, whereby an adhesive layer exhibiting the preferred oleic acid penetration amount disclosed herein can be obtained. (meth)acrylic acid C 1-6 The ratio of the alkyl ester may be 60% by weight or more and 70% by weight or more (for example, 85% by weight or more, and further 90% by weight or more). (meth)acrylic acid C 1-6 The upper limit of the ratio of the alkyl ester is not particularly limited and may be, for example, 99.5% by weight or less. Usually, in terms of other characteristics, the monomer component accounts for the above (meth)acrylic acid C. 1-6 The ratio of the alkyl ester is suitably 99% by weight or less, preferably 98% by weight or less (for example, 97% by weight or less). (meth)acrylic acid C 1-6 The alkyl esters may be used alone or in combination of two or more. As (meth)acrylic acid C 1-6 A preferred example of the alkyl ester is BA. The (meth)acrylic acid alkyl ester as the main monomer and the copolymerizable secondary monomer contribute to introduction of the acrylic polymer into the crosslinking point or increase the cohesive force of the acrylic polymer. For example, one type of the functional group-containing monomer may be used alone or two or more types may be used in combination. a monomer having a carboxyl group: an ethylenically unsaturated monocarboxylic acid such as acrylic acid (AA), methacrylic acid (MAA), carboxyethyl (meth)acrylate, crotonic acid or methacrylic acid; maleic acid, arylene An ethylenically unsaturated dicarboxylic acid such as methyl succinic acid or methyl maleic acid or an acid anhydride thereof (maleic anhydride, methylene succinic anhydride, etc.). Hydroxyl-containing monomers: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate Hydroxyalkyl (meth) acrylates; unsaturated alcohols such as vinyl alcohol and allyl alcohol; polypropylene glycol mono (meth) acrylate. Amidino group-containing monomer: for example, (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hydroxymethyl ( Methyl) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide . Amino group-containing monomer: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate. Monomer having an epoxy group: for example, glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, allyl glycidyl ether. A cyano group-containing monomer: for example, acrylonitrile or methacrylonitrile. Ketone-containing monomers: for example, diacetone (meth) acrylamide, diacetone (meth) acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetate, acetonitrile ester. a monomer having a ring containing a nitrogen atom: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinyl Pyrimidine, N-vinylpipe ?? N-vinylpyrene ?? N-vinylpyrrole, N-vinylimidazole, N-vinylcarbazole, N-vinylmorpholine, N-vinylcaprolactam, N-(methyl)acrylonitrile. Alkoxyalkylene-containing monomers: for example, 3-(meth)acryloxypropyltrimethoxydecane, 3-(meth)acryloxypropyltriethoxydecane, 3-( Methyl) propylene methoxy propyl methyl dimethoxy decane, 3-(methyl) propylene methoxy propyl methyl diethoxy decane. The functional group-containing monomer may be used alone or in combination of two or more. Among the above-mentioned functional group-containing monomers, it is preferred to use a carboxyl group-containing monomer or a hydroxyl group-containing monomer in order to achieve the introduction of the crosslinking point or the improvement of the cohesive force as described above. Preferable examples of the carboxyl group-containing monomer include acrylic acid and methacrylic acid. Any of these may be used alone or in combination of two. Examples of the hydroxyl group-containing monomer include a hydroxyl group at the terminal of a linear alkyl group having about 2 to 4 carbon atoms such as 2-hydroxyethyl acrylate or 4-hydroxybutyl (meth)acrylate (A). Base) hydroxyalkyl acrylate. The hydroxyl group-containing monomer may be used alone or in combination of two or more. The carboxyl group-containing monomer can be used in combination with a hydroxyl group-containing monomer. When the monomer component constituting the acrylic polymer contains a functional group-containing monomer, the ratio of the functional group-containing monomer to the monomer component is not particularly limited. From the viewpoint of obtaining appropriate cohesiveness in the preferred oleic acid penetration amount disclosed herein, the ratio of the functional group-containing monomer is preferably 0.1% by weight or more and 40% by weight or less (for example, 0.5% by weight or more). Further, it is about 30% by weight or less, usually about 1% by weight or more and 20% by weight or less. When the monomer component constituting the acrylic polymer contains a monomer having a carboxyl group, the ratio of the carboxyl group-containing monomer to the monomer component is usually 0.5% by weight or more from the viewpoint of cohesiveness and the like. (1% by weight or more, for example, 2% by weight or more), 20% by weight or less (preferably 18% by weight or less, for example, 15% by weight or less) is preferable. The technique disclosed herein is preferably carried out in such a manner that the monomer component contains a carboxyl group-containing monomer in an amount of approximately 3% by weight or more (preferably approximately 5% by weight or more). According to the acrylic polymer having the monomer composition, the absorbed oleic acid can be well retained in the layer of the adhesive layer (block) by the interaction of the carboxyl group and the oleic acid of the polymer. Thereby, the subsequent interface can be maintained in a state in which oleic acid is less, and the adhesion due to penetration of oleic acid is effectively suppressed. In this regard, the content of the carboxyl group-containing monomer in the monomer component is preferably substantially more than 5% by weight, may be approximately 7% by weight or more, or may be approximately 8% by weight or more, and may be substantially 9% by weight or more. The upper limit of the content of the carboxyl group-containing monomer is not particularly limited, but is usually approximately 18% by weight or less, and may be approximately 15% by weight or less (for example, approximately 12% by weight or less). Contains more (meth)acrylic acid C 7-10 An acrylic polymer composed of a monomer of an alkyl ester (for example, (meth)acrylic acid C 7-10 In the acrylic polymer having an alkyl ester as a main monomer, it is particularly effective to make the content of the carboxyl group-containing monomer (for example, AA) in the monomer component large. When the monomer component constituting the acrylic polymer contains a hydroxyl group-containing monomer, the content thereof is usually about 0.001% by weight or more and approximately 10% by weight or less (for example, approximately 0.01% by weight or more and substantially 5%) of the monomer component. The weight % or less, preferably about 0.02% by weight or more and substantially 2% by weight or less is suitable. As the monomer component constituting the acrylic polymer, other copolymerized components other than the above-mentioned secondary monomer can be used for the purpose of improving the cohesive force of the acrylic polymer. Examples of the copolymerization component include vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate; styrene, substituted styrene (α-methylstyrene, etc.), and vinyl toluene. Equivalent aromatic vinyl compound; cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, (meth)acrylic acid a cycloalkyl (meth)acrylate such as a lactide; an aryl (meth)acrylate (for example, phenyl (meth)acrylate), an aryloxyalkyl (meth)acrylate (for example, benzene (meth)acrylate) (meth) acrylate containing an aromatic ring such as oxyethyl ester) or an arylalkyl (meth) acrylate (for example, benzyl (meth) acrylate); ethylene, propylene, isoprene, butyl An olefin monomer such as a diene or an isobutylene; a chlorine-containing monomer such as vinyl chloride or vinylidene chloride; an isocyanate group-containing monomer such as 2-(meth)acryloxyethyl isocyanate; or (meth)acrylic acid An alkoxy group-containing monomer such as oxyethyl ester or ethoxyethyl (meth)acrylate; a vinyl ether monomer such as methyl vinyl ether or ethyl vinyl ether; and 1,6-hexanediol di(a) A acrylate or trimethylolpropane tri(meth) acrylate is equivalent to a polyfunctional single having two or more (for example, three or more) polymerizable functional groups (for example, (meth) acrylonitrile) in one molecule. Body; etc. The amount of the other copolymerization component is not particularly limited as long as it is appropriately selected according to the purpose and use, and is usually preferably 10% by weight or less based on the monomer component. For example, when a vinyl ester monomer (for example, vinyl acetate) is used as the other copolymerization component, the content thereof may be, for example, approximately 0.1% by weight or more (generally substantially 0.5% by weight or more) of the monomer component, and It is suitably 20% by weight or less (usually approximately 10% by weight or less). The composition of the monomer component constituting the acrylic polymer is preferably designed such that the glass transition temperature (Tg) of the acrylic polymer is approximately -15 ° C or lower (for example, approximately -70 ° C or higher and -15 ° C or lower). Here, the Tg of the acrylic polymer means a Tg obtained by the formula of Fox based on the composition of the above monomer component. The formula of Fox is a relationship between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer which is homopolymerized separately for the monomers constituting the copolymer, as shown below. 1/Tg=Σ(Wi/Tgi) Further, in the above formula of Fox, Tg represents the glass transition temperature (unit: K) of the copolymer, and Wi represents the weight fraction of the monomer i in the copolymer (weight basis) The copolymerization ratio), Tgi represents the glass transition temperature (unit: K) of the homopolymer of monomer i. As the glass transition temperature at which the homopolymer used for Tg is calculated, the values described in the publicly known data are used. For example, regarding the monomers listed below, the following values are used as the glass transition temperature of the homopolymer of the monomer. 2-ethylhexyl acrylate-70°C n-butyl acrylate-55°C ethyl acrylate-22°C methyl acrylate 8°C methyl methacrylate 105°C 2-hydroxyethyl acrylate-15°C 4-hydroxybutyl acrylate -40°C Vinyl acetate 32°C Styrene 100°C Acrylic acid 106°C Methacrylic acid 228°C For the glass transition temperature of the homopolymer of the monomer other than the above, use “Polymer Handbook” (3rd edition, John Wiley & Sons) , Inc., 1989). The highest value is used for the monomer in which a plurality of values are described in the literature. The monomer having a glass transition temperature of a homopolymer is not described in the above literature, and the value obtained by the following measurement method is used. Specifically, 100 parts by weight of a monomer, 0.2 parts by weight of 2,2'-azobisisobutyronitrile, and ethyl acetate as a polymerization solvent are placed in a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a reflux cooling tube. 200 parts by weight, and the mixture was stirred for 1 hour while flowing nitrogen gas. After removing oxygen in the polymer system in this manner, the temperature was raised at 63 ° C for 10 hours. Then, the mixture was cooled to room temperature to obtain a homopolymer solution having a solid content concentration of 33% by weight. Then, the homopolymer solution was cast-coated on a release liner and dried to prepare a test sample (a sheet-like homopolymer) having a thickness of about 2 mm. The test sample was punched out into a disk shape of 7.9 mm in diameter, clamped with a parallel plate, and a shear strain of a frequency of 1 Hz was applied using a viscoelasticity tester (ARES, manufactured by Rheometrics, model name "ARES"). The viscoelasticity was measured by a shear mode in a temperature range of -70 ° C to 150 ° C at a temperature elevation rate of 5 ° C / min, and the temperature corresponding to the peak top temperature of tan δ was taken as the Tg of the homopolymer. The Tg of the acrylic polymer is preferably about -25 ° C or less, preferably about -35 ° C or less, more preferably substantially from the viewpoint of adhesion to the adherend or the base film. -40 ° C or less. Further, from the viewpoint of the cohesive force of the adhesive layer, the Tg of the acrylic polymer is usually about -75 ° C or higher, preferably about -70 ° C or higher. The technique disclosed herein is preferably carried out in such a manner that the Tg of the acrylic polymer is approximately -65 ° C or more and approximately -40 ° C or less (for example, preferably -65 ° C or more and approximately -45 ° C or less). In a preferred embodiment, the Tg of the acrylic polymer may be approximately -65 ° C or higher and approximately -55 ° C or lower. The Tg of the acrylic polymer can be adjusted by appropriately changing the monomer composition (i.e., the kind or amount ratio of the monomers used in the synthesis of the polymer). The method for obtaining the acrylic polymer is not particularly limited, and various polymerization methods known as a method for synthesizing an acrylic polymer such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or a photopolymerization method can be suitably employed. For example, a solution polymerization method can be preferably employed. As a monomer supply method at the time of solution polymerization, a one-time addition method, a continuous supply (dropwise) method, a divided supply (drop) method, and the like, in which all of the monomer raw materials are supplied once can be suitably used. The polymerization temperature can be appropriately selected depending on the type of the monomer and the solvent to be used, the type of the polymerization initiator, and the like, and can be, for example, about 20 to 170 ° C (generally about 40 to 140 ° C). In a preferred embodiment, the polymerization temperature can be set to approximately 75 ° C or lower (more preferably approximately 65 ° C or lower, for example, approximately 45 ° C to 65 ° C). The solvent (polymerization solvent) used for the solution polymerization can be appropriately selected from previously known organic solvents. For example, an aromatic compound (for example, an aromatic hydrocarbon) such as toluene or xylene; an acetate such as ethyl acetate or butyl acetate; or an aliphatic group such as hexane, cyclohexane or methylcyclohexane can be used. Or an alicyclic hydrocarbon; a halogenated alkane such as 1,2-dicycloethane; a lower alcohol such as isopropyl alcohol (for example, a monohydric alcohol having 1 to 4 carbon atoms); an ether such as a third butyl methyl ether; A ketone such as a ketene or an acetone; or a solvent of any one or more, or a mixed solvent of two or more. The initiator to be used for the polymerization may be appropriately selected from previously known polymerization initiators depending on the kind of the polymerization method. For example, one type or two or more types of azo polymerization initiators such as 2,2'-azobisisobutyronitrile (AIBN) can be preferably used. Other preferred examples of the polymerization initiator include a peroxide-based initiator such as benzamidine peroxide (BPO) or hydrogen peroxide. Examples of the other polymerization initiator include persulfate such as potassium persulfate; substituted ethane-based initiators such as phenyl-substituted ethane; aromatic carbonyl compounds; and redox in combination with a reducing agent. Is the initiator; and so on. These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator to be used may be a normal amount, and may be, for example, about 0.005 to 1 part by weight (generally about 0.01 to 1 part by weight) in terms of 100 parts by weight of the monomer component. According to the solution polymerization described above, a polymerization reaction solution in which the acrylic polymer is dissolved in an organic solvent is obtained. The adhesive layer in the technique disclosed herein may be an adhesive composition comprising an acrylic polymer solution obtained by the above polymerization reaction solution or a suitable post treatment of the reaction liquid. As the acrylic polymer solution, those obtained by mixing the above-mentioned polymerization reaction liquid to an appropriate viscosity (concentration) can be used. Alternatively, an acrylic polymer solution prepared by dissolving an acrylic polymer by a polymerization method other than solution polymerization (for example, emulsion polymerization, photopolymerization, bulk polymerization, or the like) and dissolving the acrylic polymer in an organic solvent can be used. The weight average molecular weight (Mw) of the acrylic polymer is not particularly limited, and may be, for example, approximately 10×10. 4 Above and 500×10 4 the following. Here, Mw means a value in terms of standard polystyrene obtained by GPC (gel permeation chromatography). As the GPC device, for example, the model name "HLC-8320GPC" (column: TSK gel GMH-H (S), manufactured by Tosoh Corporation) can be used. The Mw of the acrylic polymer is preferably approximately 30 × 10 from the viewpoint of adhesive properties or oil resistance. 4 Above and 200×10 4 Below (more preferably roughly 45×10 4 Above and 150×10 4 Hereinafter, for example, approximately 65×10 4 Above and 150×10 4 The scope of the following). In a preferred aspect, the Mw of the acrylic polymer can be approximately 75×10. 4 Above and roughly 140×10 4 Following (for example, roughly 90×10 4 Above and roughly 140×10 4 the following). (Crosslinking Agent) The adhesive composition (preferably, the solvent-based adhesive composition) used for forming the adhesive layer preferably contains a crosslinking agent as an optional component. The adhesive layer of the technique disclosed herein may be contained in the form of the crosslinking agent after the crosslinking reaction, the form before the crosslinking reaction, the form of the partial crosslinking reaction, the intermediate or composite form, and the like. The above crosslinking agent is usually contained in the adhesive layer in the form of a specific crosslinking reaction. The kind of the crosslinking agent is not particularly limited, and may be appropriately selected from previously known crosslinking agents. Examples of such a crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, a melamine crosslinking agent, and a carbon dioxide. An amine crosslinking agent, an oxime crosslinking agent, an amine crosslinking agent, a peroxide crosslinking agent, a metal chelate crosslinking agent, a metal alkoxide crosslinking agent, and a metal salt crosslinking agent Wait. One type of the crosslinking agent may be used alone or two or more types may be used in combination. The type and amount of the crosslinking agent to be used can be set, for example, in such a manner as to form an adhesive layer which exhibits a preferred oleic acid penetration amount as disclosed herein. As the crosslinking agent which can be preferably used in the technique disclosed herein, an isocyanate crosslinking agent and an epoxy crosslinking agent can be exemplified. As the isocyanate crosslinking agent, a polyfunctional isocyanate (a compound having an average of two or more isocyanate groups per molecule, and a structure having an isocyanurate structure) can be preferably used. The isocyanate-based crosslinking agent may be used alone or in combination of two or more. Examples of the polyfunctional isocyanate include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. Specific examples of the aliphatic polyisocyanate include 1,2-ethylidene diisocyanate, 1,2-tetramethylene diisocyanate, 1,3-tetramethylene diisocyanate, and 1,4-four. Tetramethylene diisocyanate such as methylene diisocyanate; 1,2-hexamethylene diisocyanate, 1,3-hexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 1,5- Hexamethylene diisocyanate, hexamethylene diisocyanate such as hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate or 2,5-hexamethylene diisocyanate; 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, quaternary acid diisocyanate, and the like. Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate; cyclohexyl group such as 1,2-cyclohexyl diisocyanate, 1,3-cyclohexyl diisocyanate, and 1,4-cyclohexyl diisocyanate; Diisocyanate; cyclopentyl diisocyanate such as 1,2-cyclopentyl diisocyanate or 1,3-cyclopentyl diisocyanate; hydrogenated dimethyl diisocyanate, hydrogenated methyl phenyl diisocyanate, hydrogenated diphenylmethane Diisocyanate, hydrogenated tetramethyldimethylphenylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and the like. Specific examples of the aromatic polyisocyanate include 2,4-methylphenylene diisocyanate, 2,6-methylphenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 2,4. '-Diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2, 2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, Benzene diisocyanate, p-phenylene diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, benzene Methyl-1,4-diisocyanate, benzodimethyl-1,3-diisocyanate, and the like. A polyfunctional isocyanate having an average of three or more isocyanate groups per molecule is exemplified as a preferred polyfunctional isocyanate. The trifunctional or higher isocyanate may be a bifunctional or trifunctional or higher isocyanate polymer (for example, a 2 or a 3 polymer), a derivative (for example, a polyhydric alcohol is added to a polyfunctional isocyanate of 2 or more molecules to form an addition reaction. (product), polymer, etc. For example, a dimer or a trimer of diphenylmethane diisocyanate, an isocyanurate body of hexamethylene diisocyanate (trimer adduct of isocyanurate structure), and trihydroxyl Reaction product of methyl propane with methylphenyl diisocyanate, reaction product of trimethylolpropane and hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, polyether polyisocyanate, polyester polyisocyanate Is a polyfunctional isocyanate. As a commercial item of the polyfunctional isocyanate, the product name "Dorna TPA-100" manufactured by Asahi Kasei Chemical Co., Ltd., the trade name "Coronate L" manufactured by Tosoh Corporation, and the trade name "Coronate" manufactured by Tosoh Corporation are mentioned. HL", the product name "Coronate HK" manufactured by Tosoh Corporation, the trade name "Coronate HX" manufactured by Tosoh Corporation, and the trade name "Coronate 2096" manufactured by Tosoh Corporation. In the aspect in which the isocyanate crosslinking agent is used, the amount thereof to be used is not particularly limited. The amount of the isocyanate-based crosslinking agent to be used is, for example, approximately 0.5 part by weight or more and approximately 10 parts by weight or less based on 100 parts by weight of the acrylic polymer. The amount of the isocyanate crosslinking agent to be used in an amount of preferably 100 parts by weight or more based on 100 parts by weight of the acrylic polymer is preferably about 1 part by weight or more, and preferably about 1.5. More than the weight. In addition, the amount of the isocyanate-based crosslinking agent to be used is preferably substantially 8 parts by weight or less based on 100 parts by weight of the acrylic polymer, and is preferably substantially 5 parts by weight or less (for example, substantially less than 4 parts by weight). The epoxy-based crosslinking agent can be used without any particular limitation in a compound having two or more epoxy groups in one molecule. An epoxy-based crosslinking agent having 3 to 5 epoxy groups in one molecule is preferred. The epoxy-based crosslinking agent may be used alone or in combination of two or more. The specific examples of the epoxy-based crosslinking agent include, for example, N,N,N',N'-tetraglycidyl-m-xylylenediamine, and 1,3-bis(N,N). - diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, and the like. As a commercial item of the epoxy-based crosslinking agent, the product name "TETRAD-C" manufactured by Mitsubishi Gas Chemical Co., Ltd. and the trade name "TETRAD-X", and the trade name "EPICLON CR-5L" manufactured by DIC Corporation, The product name "DENACOL EX-512" manufactured by Nagase Chemical Co., Ltd., and the trade name "TEPIC-G" manufactured by Nissan Chemical Industries Co., Ltd. In the aspect in which the epoxy-based crosslinking agent is used, the amount thereof to be used is not particularly limited. The amount of the epoxy-based crosslinking agent to be used is, for example, more than 0 part by weight and substantially 1 part by weight or less (preferably about 0.001 to 0.5 part by weight) based on 100 parts by weight of the acrylic polymer. In view of the effect of improving the cohesive strength, the amount of the epoxy-based crosslinking agent to be used is preferably 0.002 parts by weight or more, more preferably about 0.005 parts by weight or more, based on 100 parts by weight of the acrylic polymer. More preferably, it is about 0.008 parts by weight or more. In addition, the amount of the epoxy-based crosslinking agent to be used is preferably 0.2 parts by weight or less based on 100 parts by weight of the acrylic polymer, and is preferably used. It is approximately 0.1 parts by weight or less, more preferably approximately 0.05 parts by weight or less. The technique disclosed herein can be preferably carried out using at least an isocyanate crosslinking agent as a crosslinking agent. Examples of such an aspect include a state in which an isocyanate-based crosslinking agent is used alone, and an aspect in which an isocyanate-based crosslinking agent is used in combination with another crosslinking agent. In the adhesive sheet having the adhesive layer on at least one surface of the base film described below, it is particularly useful to use an isocyanate crosslinking agent from the viewpoint of improving the grip property of the base film. A preferred example of the crosslinking agent used in combination with the isocyanate crosslinking agent is an epoxy crosslinking agent. The preferred oleic acid penetration amount disclosed herein can be preferably achieved by using an epoxy crosslinking agent in combination with an isocyanate crosslinking agent. Moreover, the adhesion to the base film (supporting substrate) can be ensured, and the cohesive force of the adhesive layer can be further improved. In the aspect including the epoxy-based crosslinking agent and the isocyanate-based crosslinking agent, the relationship between the content of the epoxy-based crosslinking agent and the content of the isocyanate-based crosslinking agent is not particularly limited. The content of the epoxy-based crosslinking agent can be, for example, approximately 1/20 or less of the content of the isocyanate crosslinking agent. It is more preferable that the content of the epoxy-based crosslinking agent is approximately 1/30 or less of the content of the isocyanate-based crosslinking agent, from the viewpoint of the adhesion to the adherend and the base film and the cohesive force. It is preferably about 1/40 or less (for example, 1/50 or less). In addition, from the viewpoint of the effect obtained by using an epoxy-based crosslinking agent in combination with an isocyanate-based crosslinking agent, the content of the epoxy-based crosslinking agent is usually set to be the content of the isocyanate-based crosslinking agent. Approximately 1/1000 or more, for example, approximately 1/500 or more is suitable. (Adhesive-imparting resin) The phenol-based adhesion-imparting resin, the terpene-based adhesion-imparting resin, the modified terpene-based adhesion-imparting resin, the rosin-based adhesion-imparting resin, the hydrocarbon-based adhesion-imparting resin, and the ring can be used. One or two or more kinds of various kinds of known adhesion-imparting resins, such as an oxygen-based adhesion-imparting resin, a polyimide-based adhesion-imparting resin, an elastic-system adhesion-imparting resin, and a ketone-based adhesion-imparting resin. By using the adhesive-imparting resin, the adhesion of the adhesive layer to the adherend can be improved, and the oil can be effectively prevented from infiltrating into the subsequent interface from the outer edge of the adhesive sheet. For example, the above-described penetration distance of oleic acid due to the evaluation of oleic acid permeability can be shortened. The type and amount of the adhesion-imparting resin to be used can be set, for example, in such a manner as to form an adhesive layer having a preferred oleic acid penetration amount and surface free energy γ disclosed herein. Examples of the phenolic adhesion-imparting resin include a terpene phenol resin, a hydrogenated terpene phenol resin, an alkylphenol resin, and a rosin phenol resin. The terpene phenol resin refers to a polymer containing a terpene residue and a phenol residue, and the concept is a copolymer containing a terpene and a phenol compound (terpene-phenol copolymer resin), or a terpene or a homopolymer thereof. The concept of both phenol-modified (phenol-modified terpene resin) by the substance or copolymer. Preferable examples of the terpene constituting the terpene phenol resin include α-pinene, β-pinene, and limonene (including d-form, l-form, and d/l (dipentene)). Monoterpenes. The hydrogenated terpene phenol resin refers to a hydrogenated terpene phenol resin having a structure in which such a terpene phenol resin is hydrogenated. It is also sometimes referred to as a hydrogenated terpene phenol resin. The alkylphenol resin is a resin (oily phenol resin) obtained from an alkylphenol and formaldehyde. Examples of the alkylphenol resin include a novolak type and a novolac type. The rosin phenol resin is typically a phenolic modified product of rosin or various rosin derivatives (including rosin esters, unsaturated fatty acid-modified rosins, and unsaturated fatty acid-modified rosin esters). Examples of the rosin phenol resin include rosin phenol resins obtained by a method of thermally polymerizing rosin or the above various rosin derivatives by acid catalyst addition phenol. Among the phenol-based adhesion-imparting resins, a terpene phenol resin, a hydrogenated terpene phenol resin, and an alkylphenol resin are preferred, and a terpene phenol resin and a hydrogenated terpene phenol resin are more preferred. Among them, terpene is preferred. Phenolic resin. Examples of the terpene-based adhesion-imparting resin include terpene-based (for example, monoterpene) polymers such as α-pinene, β-pinene, d-limonene, l-limonene, and dipentene. It may be a homopolymer of one terpene or a copolymer of two or more terpenes. Examples of the homopolymer of one terpene include an α-pinene polymer, a β-pinene polymer, and a dipentene polymer. Examples of the modified terpene resin include those obtained by modifying the above terpene resin. Specifically, a styrene-modified terpene resin, a hydrogenated terpene resin, or the like can be exemplified. The concept of the rosin-based adhesion-imparting resin herein includes both rosin-based and rosin-derived resins. Examples of the rosin include unmodified rosin (raw rosin) such as gum rosin, wood rosin, tall oil rosin, and modified rosin obtained by hydrogenation, disproportionation, polymerization, etc. of the unmodified rosin (hydrogenated) Rosin, disproportionated rosin, polymerized rosin, other chemically modified rosin, etc.); The rosin derivative resin is typically a rosin derivative as described above. The concept of the rosin-based resin herein includes a derivative of an unmodified rosin and a derivative of a modified rosin (including hydrogenated rosin, disproportionated rosin, and polymerized rosin). For example, an unmodified rosin ester which is an ester of an unmodified rosin and an alcohol, or a rosin ester which is a modified rosin ester which is an ester of a modified rosin and an alcohol; for example, a rosin is modified by using an unsaturated fatty acid. Sexually unsaturated fatty acid-modified rosins; for example, rosin esters modified with unsaturated fatty acids modified unsaturated fatty acids; for example, rosins or various rosin derivatives as described above (including rosin esters, A rosin alcohol which is subjected to reduction treatment of a carboxyl group of an unsaturated fatty acid-modified rosin and an unsaturated fatty acid-modified rosin ester; for example, a rosin or a metal salt of the above various rosin derivatives; and the like. Specific examples of the rosin esters include methyl esters, triethylene glycol esters, glycerin esters, and pentaerythritol esters of unmodified rosin or modified rosin (hydrogenated rosin, disproportionated rosin, and polymerized rosin). Examples of the hydrocarbon-based adhesion-providing resin include an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, an aliphatic cyclic hydrocarbon resin, and an aliphatic/aromatic petroleum resin (styrene-olefin copolymer). Various aliphatic resins such as aliphatic and alicyclic petroleum resins, hydrogenated hydrocarbon resins, scented scented resins, and scented scented resins. The softening point of the adhesive imparting resin is not particularly limited. From the viewpoint of improving the cohesive force, in one aspect, an adhesion-imparting resin having a softening point (softening temperature) of approximately 80 ° C or more (preferably substantially 100 ° C or more) can be preferably used. The technique disclosed herein preferably has a state in which the adhesion imparting resin having the softening point has more than 50% by weight (more preferably more than 70% by weight, for example, more than 90% by weight) in the entire adhesive-imparting resin contained in the adhesive layer. Implement as such. For example, a phenol-based adhesion-imparting resin (such as a terpene phenol resin) having such a softening point can be preferably used. In a preferred embodiment, a terpene phenol resin having a softening point of approximately 135 ° C or higher (and further approximately 140 ° C or higher) can be used. The upper limit of the softening point of the adhesion imparting resin is not particularly limited. From the viewpoint of the adhesion to the adherend or the base film, in one aspect, an adhesive-imparting resin having a softening point of approximately 200 ° C or less (more preferably approximately 180 ° C or less) can be preferably used. Further, the softening point of the adhesion-imparting resin can be measured based on the softening point test method (ring and ball method) prescribed in JIS K2207. In the aspect in which the resin is applied by adhesion, the content of the adhesion-imparting resin is not particularly limited. The content of the adhesion-imparting resin may be, for example, about 5 parts by weight or more, or about 8 parts by weight or more (for example, approximately 10 parts by weight or more) based on 100 parts by weight of the acrylic polymer. The technique disclosed herein can also be preferably carried out in such a manner that the content of the adhesive-imparting resin is approximately 15 parts by weight or more (for example, 25 parts by weight or more) based on 100 parts by weight of the acrylic polymer. The upper limit of the content of the adhesion-imparting resin is not particularly limited. From the viewpoint of the compatibility with the acrylic polymer or the initial adhesion property, in one aspect, the content of the adhesion-imparting resin to 100 parts by weight of the acrylic polymer is preferably substantially 70 parts by weight or less. It is preferably about 55 parts by weight or less, more preferably about 45 parts by weight or less (for example, about 40 parts by weight or less). In the aspect of using the adhesive-imparting resin, 50% by weight or less of the total amount of the adhesive-imparting resin is preferably selected from the adhesive-imparting resins other than the rosin-based adhesive-imparting resin. The ratio of the rosin-based adhesion-imparting resin to the total amount of the adhesion-imparting resin is preferably 25% by weight or less, more preferably 10% by weight or less (for example, less than 5% by weight). Further, the amount of the rosin-based adhesion-imparting resin to be used is preferably less than 10 parts by weight, more preferably less than 5 parts by weight, based on 100 parts by weight of the acrylic polymer. The use of the rosin-based adhesive-imparting resin is likely to cause an excessive increase in the amount of oleic acid permeation depending on the type and amount of use. Further, there is a tendency that the surface free energy γ is increased by using a rosin-based adhesion-imparting resin. By limiting the amount of the rosin-based adhesion-imparting resin to 100 parts by weight relative to the acrylic polymer to less than 10 parts by weight, it is easy to obtain an adhesive layer having a oleic acid penetration amount and a surface free energy γ in a preferred range. The technique disclosed herein can also be carried out in such a manner that the adhesive layer does not substantially contain the rosin-based adhesive imparting resin. In a preferred embodiment, the adhesion-imparting resin contains one or two or more kinds of phenol-based adhesion-imparting resins (for example, terpene phenol resins). The phenolic adhesion-imparting resin tends to have a lower affinity for oil than the rosin-based adhesion-imparting resin. Therefore, by using the phenol-based adhesion-imparting resin, it is possible to suppress an excessive increase in the amount of oleic acid permeation and to improve the adhesion of the adhesive layer to the adherend (for example, the effect of shortening the penetration distance). The technique disclosed herein can be carried out, for example, in a state in which the total amount of the resin to be applied is approximately 25% by weight or more (more preferably approximately 30% by weight or more) as the terpene phenol resin. About 50% by weight or more of the total amount of the adhesion-imparting resin may be a terpene phenol resin, and about 80% by weight or more (for example, approximately 90% by weight or more) may be a terpene phenol resin. The entire amount of the adhesion-imparting resin (for example, approximately 95% by weight or more and 100% by weight or less, and further preferably approximately 99% by weight or more and 100% by weight or less) may be a terpene phenol resin. The content of the phenol-based adhesion-imparting resin (for example, terpene phenol resin) is approximately 5 parts by weight or more and approximately 45 parts by weight or less (for example, approximately 5 parts by weight or more and approximately 40 parts by weight or less) based on 100 parts by weight of the acrylic polymer. Suitably, it is preferably about 8 parts by weight or more and about 35 parts by weight or less. It is not particularly limited, and as the adhesion-imparting resin in the technique disclosed herein, an adhesion-imparting resin having a hydroxyl value of less than 30 mgKOH/g (for example, less than 20 mgKOH/g) can be used. Hereinafter, an adhesion-imparting resin having a hydroxyl value of less than 30 mgKOH/g is sometimes referred to as a "low hydroxyl value resin". The hydroxyl value of the low hydroxyl value resin may be approximately 15 mgKOH/g or less, or may be approximately 10 mgKOH/g or less. The lower limit of the hydroxyl value of the low hydroxyl value resin is not particularly limited and may be substantially 0 mgKOH/g. Such a low hydroxyl value resin (for example, a terpene phenol resin) can be preferably used, for example, with (meth)acrylic acid C. 7-10 The combination of the acrylic polymer which is an alkyl ester as a main monomer can exhibit the effect of improving the adhesion of the adhesive layer to the adherend (for example, the effect of shortening the penetration distance). It is not particularly limited, and as the adhesion-imparting resin in the technique disclosed herein, an adhesion-imparting resin having a hydroxyl value of 30 mgKOH/g or more can be used. Hereinafter, an adhesive-imparting resin having a hydroxyl value of 30 mgKOH/g or more is referred to as a "high hydroxyl value resin". The upper limit of the hydroxyl value of the high hydroxyl value resin is not particularly limited. The hydroxyl value of the high hydroxyl value resin is usually approximately 200 mgKOH/g or less from the viewpoint of compatibility with the acrylic polymer, etc., and is preferably approximately 180 mgKOH/g or less, more preferably approximately 160 mgKOH/g or less. Further, it is preferably about 140 mgKOH/g or less. An adhesion-imparting resin containing such a high hydroxyl value resin (for example, a terpene phenol resin) is preferably used, for example, with (meth)acrylic acid C. 1-6 The combination of the acrylic polymer which is an alkyl ester as a main monomer can exhibit the effect of improving the adhesion of the adhesive layer to the adherend (for example, the effect of shortening the penetration distance). Here, as the value of the above hydroxyl value, a value measured by a potentiometric titration method prescribed in JIS K0070:1992 can be employed. The specific measurement method is as follows. [Method for Measuring Hydroxyl Value] 1. Reagent (1) As an acetamidine reagent, about 12.5 g (about 11.8 mL) of acetic anhydride was used, and pyridine was added thereto to make the total amount 50 mL, which was sufficiently stirred. Alternatively, about 25 g (about 23.5 mL) of acetic anhydride is used, and pyridine is added thereto to make the total amount 100 mL, which is sufficiently stirred. (2) As a measuring reagent, a 0.5 mol/L potassium hydroxide ethanol solution was used. (3) Other preparations of toluene, pyridine, ethanol and distilled water. 2. Operation (1) Accurately weigh approximately 2 g of the sample in a flat-bottomed flask, add 5 mL of acetamidine reagent and 10 mL of pyridine, and install an air cooling tube. (2) The flask was heated in a bath at 100 ° C for 70 minutes, left to cool, and 35 mL of toluene as a solvent was added from the upper portion of the cooling tube and stirred, and then 1 mL of distilled water was added thereto and stirred to decompose acetic anhydride. In order to completely decompose, it was heated again in the bath for 10 minutes, and left to stand for cooling. (3) Clean the cooling tube with 5 mL of ethanol and take it out. Then, 50 mL of pyridine as a solvent was added and stirred. (4) Using a full pipette 25 mL, add 0.5 mol/L potassium hydroxide ethanol solution. (5) Potentiometric titration was performed using a 0.5 mol/L potassium hydroxide ethanol solution. The inflection point of the obtained titration curve is set as the end point. (6) In the empty test, the above (1) to (5) were carried out without placing a sample. 3. Calculation The hydroxyl value was calculated according to the following formula. Hydroxyl value (mgKOH/g) = [(B-C) × f × 28.05] / S + D Here, B: amount of 0.5 mol / L potassium hydroxide ethanol solution used in the empty test (mL), C: sample The amount of 0.5 mol/L potassium hydroxide ethanol solution used (mL), f: 0.5 mol/L potassium hydroxide ethanol solution factor, S: sample weight (g), D: acid value, 28.05: hydrogen The molecular weight of potassium oxide is 1/2 of 56.11. As the low hydroxyl value resin and the high hydroxyl value resin, those having any of the above-mentioned various adhesion-imparting resins can be used. The low-hydroxyl resin and the high-hydroxyl resin may be used alone or in combination of two or more. For example, as the low hydroxyl value resin, a phenol-based adhesion-imparting resin having a hydroxyl value of less than 30 mgKOH/g can be preferably used. Further, for example, as the high hydroxyl value resin, a phenol-based adhesion-imparting resin having a hydroxyl value of 30 mgKOH/g or more can be preferably used. Among them, a terpene phenol resin is preferred. The terpene phenol resin is preferably controlled by arbitrarily controlling the hydroxyl value according to the copolymerization ratio of phenol. (Other Additives) In addition to the above components, the adhesive composition may optionally contain a leveling agent, a crosslinking assistant, a plasticizer, a softener, an antistatic agent, an antiaging agent, an ultraviolet absorber, an antioxidant, and a light stabilizer. Various additives commonly used in the field of adhesives such as agents. Regarding such various additives, those conventionally known to those skilled in the art can be used, and in particular, the features of the present invention are not particularly limited. The adhesive layer disclosed herein may be an adhesive layer formed of a water-based adhesive composition, a solvent-based adhesive composition, a hot-melt adhesive composition, and an active energy ray-curable adhesive composition. The water-based adhesive composition refers to an adhesive composition in the form of an adhesive (adhesive layer-forming component) in a solvent (aqueous solvent) containing water as a main component, and typically includes a water-dispersed adhesive. A composition (a composition in which at least a part of an adhesive is dispersed in water) or the like. Further, the solvent-based adhesive composition refers to an adhesive composition containing an adhesive in an organic solvent. The technique disclosed herein is particularly preferably carried out in the form of an adhesive layer formed of a solvent-based adhesive composition from the viewpoint of adhesion characteristics and the like. The adhesive layer disclosed herein can be formed using previously known methods. For example, a method in which an adhesive composition is directly imparted (typically applied) to a non-releasable substrate and dried to thereby form an adhesive layer (direct method) can be employed. Further, a method in which an adhesive composition is applied to a surface having a peeling property (release surface) and dried to form an adhesive layer on the surface, and the adhesive layer is transferred to a non-releasable substrate (Transfer method). From the viewpoint of productivity, a transfer method is preferred. As the peeling surface, the surface of the release liner or the back surface of the substrate subjected to the release treatment can be used. Further, the adhesive layer disclosed herein is typically formed continuously, but is not limited to such a form, and may be formed, for example, as an adhesive layer having a regular or random pattern such as a dot shape or a striped shape. The application of the adhesive composition can be carried out, for example, by a conventionally known coater such as a gravure roll coater, a die coater, or a bar coater. Alternatively, the adhesive composition may be applied by an impregnation or curtain coating method or the like. From the viewpoint of promoting the crosslinking reaction and improving the production efficiency, it is preferred that the drying of the adhesive composition is carried out under heating. The drying temperature can be, for example, about 40 to 150 ° C, and usually about 60 to 130 ° C. After the adhesive composition is dried, it is possible to adjust the component migration in the adhesive layer, to carry out the crosslinking reaction, to relax the deformation which may be present in the base film or the adhesive layer, and to perform aging. The thickness of the adhesive layer is not particularly limited. The thickness of the adhesive layer is usually about 100 μm or less from the viewpoint of avoiding excessive thickening of the adhesive sheet, and is preferably about 70 μm or less, more preferably about 50 μm or less, and still more preferably about 30 μm or less. . In a preferred embodiment of the adhesive sheet, the thickness of the adhesive layer is approximately 25 μm or less (usually less than 25 μm, preferably approximately 22 μm or less, for example, approximately 20 μm or less). In the adhesive sheet having such a relatively small thickness of the adhesive layer, since the adhesive amount per unit area of the adhesive sheet is small, it is particularly effective to set the oleic acid permeation amount of the adhesive layer to a specific value or more. The lower limit of the thickness of the adhesive layer is not particularly limited, and is preferably about 4 μm or more from the viewpoint of the adhesion of the adherend, and is preferably about 6 μm or more, more preferably about 10 μm or more (for example, roughly 15 μm or more). The technique disclosed herein can be preferably carried out, for example, in the form of an adhesive sheet having an adhesive layer having a thickness of approximately 10 μm or more and approximately 25 μm or less (preferably approximately 15 μm or more and approximately 22 μm or less). An adhesive sheet having an adhesive layer of this thickness on both sides of the substrate is preferred. (gel fraction) is not particularly limited, but the gel fraction of the adhesive layer disclosed herein may be, for example, 20% or more by weight, and usually 30% or more, preferably 35%. the above. By increasing the gel fraction of the adhesive layer in a moderate range, it is easy to achieve the appropriate oleic acid penetration amount disclosed herein. On the other hand, if the gel fraction is too high, it may easily cause insufficient oleic acid penetration. From this point of view, the gel fraction of the adhesive layer is preferably 90% or less, more preferably 80% or less, still more preferably 70% or less (for example, 65% or less). Here, the "gel fraction of the adhesive layer" means a value measured by the following method. The gel fraction can be grasped by the weight ratio of the ethyl acetate-insoluble component in the adhesive layer. [Method for measuring gel fraction] About 0.1 g of the adhesive sample (weight Wg) 1 ) Porous polytetrafluoroethylene film with an average pore diameter of 0.2 μm (weight Wg) 2 ) packaged into a purse, using a kite line (weight Wg) 3 ) tie the mouth. As the porous polytetrafluoroethylene (PTFE) film, a product name "Nittoflon (registered trademark) NTF1122" (having an average pore diameter of 0.2 μm, a porosity of 75%, and a thickness of 85 μm) which can be obtained from Nitto Denko Corporation or Quite a product. The package was immersed in 50 mL of ethyl acetate, and kept at room temperature (typically 23 ° C) for 7 days. After the sol component in the adhesive layer was dissolved outside the film, the package was taken out. The ethyl acetate adhered to the outer surface was wiped off, and the package was dried at 130 ° C for 2 hours, and the weight of the package was measured (Wg 4 ). Gel fraction of adhesive layer F G This is obtained by substituting each value into the following equation. The same method is also employed in the following examples. Gel fraction F G (%)=[(Wg 4 -Wg 2 -Wg 3 )/Wg 1 ]×100 <Substrate> In the aspect in which the adhesive sheet disclosed herein is in the form of a single-sided adhesive type or a double-sided adhesive type adhesive-attached sheet, it serves as a base for supporting the (substrate) adhesive layer. As the material, a resin film, paper, cloth, rubber sheet, foam sheet, metal foil, a composite of these, or the like can be used. Examples of the resin film include polyolefin films such as polyethylene (PE), polypropylene (PP), and ethylene/propylene copolymer; polyester films such as polyethylene terephthalate (PET); and vinyl chloride. Resin film; vinyl acetate resin film; polyimine resin film; polyamine resin film; fluororesin film; Examples of the paper include Japanese paper, kraft paper, cellophane, Daolin paper, synthetic paper, and topcoat paper. Examples of the cloth include a woven fabric or a non-woven fabric obtained by separately or blending various fibrous materials. Examples of the fibrous material include cotton, staple fiber, manila hemp, pulp, enamel, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, and polyolefin fiber. Examples of the rubber sheet include a natural rubber sheet and a butyl rubber sheet. Examples of the foam sheet include a foamed polyurethane sheet, a foamed polychloroprene rubber sheet, and the like. Examples of the metal foil include aluminum foil, copper foil, and the like. In addition, the term "non-woven fabric" as used herein mainly refers to the concept of non-woven fabric for adhesive sheets used in the field of adhesive tapes and other adhesive sheets, and is typically a non-woven fabric produced by a general paper machine (also sometimes referred to as a so-called nonwoven fabric). "paper"). Further, the resin film referred to herein is typically a non-porous resin sheet, for example, which is different from the non-woven fabric (that is, does not contain a nonwoven fabric). The resin film may be any one of a non-stretched film, a one-axis stretched film, and a biaxially stretched film. Further, surface treatment such as coating of a primer, corona discharge treatment, or plasma treatment may be performed on the surface of the substrate on which the pressure-sensitive adhesive layer is provided. The technique disclosed herein can be preferably carried out in the form of an adhesive sheet with a base material in which at least one surface of the base film (support) has the above-mentioned adhesive layer. For example, it can be implemented in the form of the double-sided adhesive sheet which has the base material of the said adhesive layer on one surface and the other surface of a base film. As the base film, a resin film as a base film can be preferably used. The base film described above is typically a separate (non-dependent) member that maintains shape. The substrate film in the techniques disclosed herein can be substantially constructed from such a base film. Alternatively, the base film may include an auxiliary layer in addition to the base film. Examples of the auxiliary layer include an undercoat layer, an antistatic layer, a colored layer, and the like provided on the surface of the base film. The resin film is a film containing a resin material as a main component (the resin film contains more than 50% by weight of a component). Examples of the resin film include polyolefin resin films such as polyethylene (PE), polypropylene (PP), and ethylene/propylene copolymer; polyethylene terephthalate (PET) and polyterephthalic acid. Polyester resin film such as butadiene diester (PBT) or polyethylene naphthalate (PEN); vinyl chloride resin film; vinyl acetate resin film; polyimine resin film; polyamine resin Film; fluororesin film; cefofen; The resin film may be a rubber film such as a natural rubber film or a butyl rubber film. Among them, a polyester film is preferable from the viewpoint of workability and workability, and among them, a PET film is particularly preferable. In addition, the "resin film" in this specification is typically a non-porous sheet and is different from the concept of a non-woven fabric or a woven fabric (in other words, a concept other than a nonwoven fabric or a woven fabric). In the above resin film (for example, PET film), a filler (inorganic filler, organic filler, etc.), a colorant, a dispersant (surfactant, etc.), an anti-aging agent, an antioxidant, an ultraviolet absorber, and an antistatic may be formulated as needed. Various additives such as agents, lubricants, plasticizers. The blending ratio of the various additives is usually about 30% by weight (e.g., substantially less than 20% by weight, preferably about 10% by weight or less). The resin film may have a single layer structure or a multilayer structure having two layers, three layers or more. The resin film is preferably a single layer structure from the viewpoint of shape stability. In the case of a multilayer structure, at least one layer (preferably all layers) is preferably a layer having a continuous structure of the above-mentioned resin (for example, a polyester resin). The method for producing the resin film is not particularly limited as long as a conventionally known method is appropriately employed. For example, a conventionally known general film forming method such as extrusion molding, expansion molding, T die casting, or calender roll molding can be suitably employed. The thickness of the base film disclosed herein is not particularly limited. The thickness of the base film can be, for example, approximately 200 μm or less, preferably approximately 150 μm or less, and more preferably approximately 100 μm or less from the viewpoint of avoiding excessive thickening of the adhesive sheet. The thickness of the base film may be approximately 70 μm or less, may be approximately 50 μm or less, or may be approximately 30 μm or less (for example, approximately 25 μm or less), depending on the purpose of use or the use of the adhesive sheet. In one aspect, the thickness of the base film may be approximately 20 μm or less, may be approximately 15 μm or less, and may be approximately 10 μm or less (for example, approximately 5 μm or less). By reducing the thickness of the base film, the thickness of the adhesive layer can be increased even if the total thickness of the adhesive sheet is the same. This is advantageous in terms of improving the adhesion to the substrate. The lower limit of the thickness of the base film is not particularly limited. The thickness of the base film is usually approximately 0.5 μm or more (for example, 1 μm or more), preferably approximately 2 μm or more, for example, approximately 4 μm or more, from the viewpoints of rationality (operability) or workability of the adhesive sheet. . In one aspect, the thickness of the substrate film may be approximately 6 μm or more, may be approximately 8 μm or more, and may be approximately 10 μm or more (for example, more than 10 μm). A conventionally known surface treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, or application of a primer can be applied to the surface of the base film. Such a surface treatment can be a treatment for improving the adhesion between the base film and the adhesive layer, in other words, the adhesiveness of the adhesive layer and the substrate film. <Release liner> In the technique disclosed herein, a release liner can be used in the formation of an adhesive layer, the production of an adhesive sheet, the storage, distribution, and shape processing of an adhesive sheet before use. The release liner is not particularly limited, and for example, a release liner having a release treatment layer on the surface of a liner substrate such as a resin film or paper, or a fluorine-based polymer (such as polytetrafluoroethylene) or a polyolefin may be used. A release liner of a low-adhesive material such as a resin (polyethylene or polypropylene). The release treatment layer may be formed by, for example, surface-treating the liner substrate with a release treatment agent such as polyfluorene-based, long-chain alkyl, fluorine or molybdenum sulfide. <Adhesive Sheet> The total thickness of the adhesive sheet (excluding the release liner) disclosed herein is not particularly limited. The total thickness of the adhesive sheet can be, for example, approximately 500 μm or less, and is usually preferably approximately 350 μm or less, and is preferably approximately 250 μm or less (for example, approximately 200 μm or less). The technique disclosed herein may be an adhesive sheet (typically a double-sided adhesive sheet) having a total thickness of approximately 150 μm or less (more preferably approximately 100 μm or less, further preferably approximately less than 60 μm, for example, approximately 55 μm or less). It is implemented in the form. The lower limit of the thickness of the adhesive sheet is not particularly limited, but is usually about 10 μm or more, preferably about 20 μm or more, and more preferably about 30 μm or more. According to the technique disclosed herein, it is possible to provide an adhesive sheet in which the adhesion maintaining ratio exceeds 50% in the following evaluation of oil resistance. In an adhesive sheet which is preferably one aspect, the adhesion maintaining ratio may be 60% or more (for example, 65% or more). The upper limit of the adhesion maintaining ratio is not particularly limited, and is usually 150% or less, preferably 100% or less. [Evaluation of oil resistance] The adhesive sheet was cut into a size of 10 mm in width and 100 mm in length to prepare a sample piece. Here, in the case where the adhesive sheet of the measurement state is a double-sided adhesive sheet, a PET film substrate having a thickness of 50 μm is attached to one adhesive surface, and then cut into the above size. The measurement surface was prepared by pressure-bonding the adhesive surface of the sample piece to a stainless steel plate (SUS304BA plate) in an environment of 23 ° C and 50% RH. The above crimping is performed by reciprocating the 2 kg drum once. After the measurement sample was allowed to stand in an environment of 23° C. and 50% RH for 30 minutes, the peel strength was measured by a tensile tester according to JIS Z0237:2000 at a tensile speed of 150 mm/min and a peeling angle of 180 degrees. (N/10 mm). This value is set as the adhesion before impregnation. On the other hand, the measurement sample prepared in the same manner as above was allowed to stand in an environment of 23° C. and 50% RH for 30 minutes, and then immersed in an oleic acid bath and kept in an environment of 40° C. and 90% RH for 2 weeks. Thereafter, the above-mentioned measurement sample was lifted from the oleic acid bath, and the oleic acid adhered to the surroundings was gently wiped off, and allowed to stand in an environment of 23° C. and 50% RH for 30 minutes, and then measured in the same manner as the pre-impregnation adhesion. Peel strength (N/10 mm). This value is set as the adhesion after immersion. From the measured values obtained, the following formula was used: Adhesion retention ratio (%) = (adhesion after immersion/adhesion before immersion) × 100; and the adhesion retention ratio was calculated. In addition, as the tensile tester, for example, the "precision universal testing machine autostereoscopic plotter AG-IS50N" manufactured by Shimadzu Corporation can be used. The same evaluation method was also employed in the following examples. In the adhesive sheet disclosed herein, the adhesion before the immersion is not particularly limited. Preferably, the adhesive sheet of the adhesive sheet has a pre-impregnation adhesion of approximately 3.0 N/10 mm or more. The adhesive sheet exhibiting such an adhesive force before immersion has a high adhesiveness to the adherend, and therefore can be excellent in preventing the oil from immersing from the outer edge of the adhesive sheet to the subsequent interface. More preferably, it is an adhesive sheet having an adhesive force of approximately 5.0 N/10 mm or more (for example, approximately 6.0 N/10 mm or more) before impregnation. The higher the adhesion to the adherend, the better. Therefore, the upper limit of the adhesive force before the immersion is not particularly limited, and is usually approximately 30 N/10 mm or less (for example, approximately 20 N/10 mm or less). It is not particularly limited, and the adhesion after the immersion is preferably 1.0 N/10 mm or more from the viewpoint of suppressing the overflow of the adhesive. The adhesion after the immersion is preferably approximately 2.0 N/10 mm or more, more preferably approximately 3.0 N/10 mm or more, still more preferably approximately 4.0 N/10 mm or more (for example, approximately 5.0 N/10 mm or more, and further approximately 6.0). N/10 mm or more). The adhesive sheet showing such adhesion after immersion is preferably used, for example, for fixing a member which can be contacted with an oil component. <Use> The adhesive sheet disclosed herein has less adhesive strength and inhibits the overflow of the adhesive even if it is in contact with the oil. With such a feature, the above adhesive sheet can be preferably used for fixing various members which are in contact with oil. As a representative example of such use, the use of a fixing member in various mobile devices (portable devices) can be cited. For example, it is preferably used for the fixed use of components in portable electronic machines. Non-limiting examples of the portable electronic device include a mobile phone, a smart phone, a tablet computer, a notebook computer, and various wearable devices (for example, a wrist-worn wristband, a clip or a lanyard, such as a wristwatch. An eye protection type that is worn on one part of the body, a single-eye type or a double-eye type (including a head-mounted type), a shirt type, a sock, a hat, etc., for example, a type of clothing worn in the form of a jewelry, such as a headphone. Generally worn on the ear ear protection, etc.), digital camera, digital video camera, audio equipment (walkman, IC recorder, etc.), computer (calculator, etc.), portable game device, electronic dictionary, electronic note This, e-books, in-vehicle information equipment, portable radio, portable TV, portable printer, portable scanner, portable data machine, etc. Non-limiting examples of mobile devices other than portable electronic devices include mechanical watches or pocket watches, flashlights, handheld mirrors, monthly ticket holders, and the like. Furthermore, the term "portable" as used in this specification is merely portable and insufficient, meaning that it has the portability of a person (standard adult) that is relatively easy to ship. The adhesive sheet (typically a double-sided adhesive sheet) disclosed herein can be processed into a form of a joint material of various shapes for fixing a member constituting a mobile device. As a particularly preferable use, the use of a member constituting a portable electronic device can be cited. Among them, it can be preferably used in a portable electronic device having a liquid crystal display device. For example, such a portable electronic device is preferably used for a display unit (which may be a display portion of a liquid crystal display device) or a display portion protection member for bonding to a casing. A preferred embodiment of such a bonding material is a form having a narrow portion having a width of 4.0 mm or less (for example, 2.0 mm or less, usually less than 2.0 mm). The adhesive sheet disclosed herein is excellent in cohesive strength in addition to oil resistance. Therefore, even if it is used as a joint material having a shape (for example, a frame shape) including such a thin portion, the member can be well fixed. In one aspect, the width of the thin portion may be 1.5 mm or less, may be 1.0 mm or less, and may be about 0.5 mm or less. The lower limit of the width of the thin portion is not particularly limited, and is usually 0.1 mm or more (for example, 0.2 mm or more) from the viewpoint of the workability of the adhesive sheet. The above-mentioned thin portion is typically linear. Here, the linear shape includes a ring shape such as a frame shape or a circular shape, or a combination of these or a combination of intermediate shapes, in addition to a linear shape, a curved shape, and a polygonal line shape (for example, an L shape). The above-described annular shape is not limited to a shape composed of a curved line, and for example, a shape along the outer circumference of the square shape (frame shape) or a shape along the outer circumference of the fan shape, and includes a concept in which a part or all of the ring shape is formed in a straight line shape. The length of the above-mentioned thin portion is not particularly limited. For example, in the form in which the length of the thin portion is 10 mm or more (more preferably 20 mm or more, for example, 30 mm or more), the effect of applying the technique disclosed herein can be preferably exerted. The matters disclosed in this specification include the following. (1) An adhesive sheet comprising an adhesive layer composed of an adhesive of an acrylic polymer as a base polymer, and a surface free energy γ of the above adhesive layer is substantially less than 40 mJ/m 2 And the oleic acid permeation amount is approximately 1.5 g or more and approximately 5.0 g or less. (2) The adhesive sheet according to (1) above, wherein the adhesive layer has a gel fraction of approximately 30% or more and substantially 70% or less. (3) The adhesive sheet according to the above (1) or (2), wherein the adhesive layer is formed using an adhesive composition comprising the acrylic polymer and a crosslinking agent. (4) The adhesive sheet according to (3) above, wherein the crosslinking agent comprises an isocyanate crosslinking agent. (5) The adhesive sheet according to any one of the above-mentioned (1), wherein the adhesive layer contains an adhesive-imparting resin, and the adhesive-imparting resin is substantially 50% by weight or more of an adhesive-imparting resin other than the rosin-based resin. . (6) The adhesive sheet according to any one of the above (1) to (5) wherein the monomer component constituting the acrylic polymer contains substantially more than 50% by weight of the alkyl (meth)acrylate C 7-10 ester. (7) The adhesive sheet according to the above (6), wherein the monomer component constituting the acrylic polymer contains substantially more than 5% by weight of a carboxyl group-containing monomer. (8) The adhesive sheet according to any one of the above (1) to (7) wherein the monomer component constituting the acrylic polymer contains substantially 70% by weight or more of (meth)acrylic acid C 7-10 An alkyl ester and a carboxyl group-containing monomer of approximately 7% by weight or more and approximately 15% by weight or less. (9) The adhesive sheet according to (8) above, wherein the above (meth)acrylic acid C 7-10 The alkyl ester is one or more selected from the group consisting of 2-ethylhexyl acrylate, isooctyl acrylate and isodecyl acrylate. The carboxyl group-containing monomer is acrylic acid, methacrylic acid or a combination thereof. The adhesive sheet according to any one of the above-mentioned (6), wherein the adhesive layer contains an adhesive-imparting resin, and substantially 50% by weight or more of the adhesive-imparting resin is a phenol-based adhesive-providing resin (for example, ruthenium). Enphenol resin). (11) The adhesive sheet according to the above (10), wherein the phenol-based adhesion-imparting resin contains a terpene phenol resin having a hydroxyl value of substantially less than 30 mgKOH/g. (12) The adhesive sheet according to any one of the above (1) to (5) wherein the monomer component constituting the acrylic polymer contains substantially more than 50% by weight of (meth)acrylic acid C 1-6 Alkyl ester. (13) The adhesive sheet according to the above (12), wherein the monomer component constituting the acrylic polymer contains substantially more than 3% by weight of a carboxyl group-containing monomer. (14) The adhesive sheet according to (13) above, wherein the above (meth)acrylic acid C 1-6 The alkyl ester is one or more selected from the group consisting of n-butyl acrylate, ethyl acrylate and methyl acrylate, and the carboxyl group-containing monomer is acrylic acid, methacrylic acid or a combination thereof. The adhesive sheet according to any one of the above-mentioned (12), wherein the adhesive layer contains an adhesive-imparting resin, and substantially 50% by weight or more of the adhesive-imparting resin is a phenol-based adhesive-providing resin (for example, ruthenium). Enphenol resin). (16) The adhesive sheet according to the above (15), wherein the phenolic adhesion-imparting resin contains a terpene phenol resin having a hydroxyl value of approximately 30 mgKOH/g or more. The adhesive sheet according to any one of the above (1) to (16) wherein the adhesive layer is formed by using a solvent-based adhesive composition containing an adhesive in an organic solvent. (18) The adhesive sheet according to (17) above, wherein the organic solvent comprises at least one of toluene and ethyl acetate. The adhesive sheet according to any one of the above (1), wherein the thickness of the adhesive layer is approximately 10 μm or more and 25 μm or less. (20) The adhesive sheet according to any one of the above (1) to (19), wherein the adhesive sheet of the adhesive layer is provided on one surface and the other surface of the substrate. (21) The adhesive sheet according to (20) above, wherein the substrate is a PET film having a single layer structure. (22) The adhesive sheet according to any one of the above (1) to (21), which is used for fixing the member in the mobile device. (23) A moving device having a member fixed by using the adhesive sheet according to any one of the above (1) to (22). (24) The mobile device according to (23) above, wherein the mobile device is a wearable device (for example, a wrist-worn wearable device). [Examples] Hereinafter, several examples of the present invention are described, but the present invention is not limited to the examples. In the following description, "parts" and "%" are based on weight unless otherwise specified. <Preparation of Acrylic Polymer Solution> (Acrylic Polymer A) 90 parts of 2EHA and 10 parts of AA as a monomer component were added to a reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux condenser, and a dropping funnel. 199 parts of ethyl acetate as a polymerization solvent was stirred for 2 hours while introducing nitrogen gas. In this manner, after removing oxygen in the polymerization system, 0.2 part of benzoyl peroxide as a polymerization initiator was added, and solution polymerization was carried out at 60 ° C for 6 hours to obtain a solution of the acrylic polymer A. The acrylic polymer A has a Mw of about 120×10 4 . (Acrylic Polymer B) 100 parts of 2EHA, 2 parts of methyl methacrylate (MMA), and AA were added as a monomer component to a reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux condenser, and a dropping funnel. Two parts of 190 parts of toluene as a polymerization solvent were stirred for 2 hours while introducing nitrogen gas. In this manner, after removing oxygen in the polymerization system, 0.3 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was added, and solution polymerization was carried out at 60 ° C for 6 hours to obtain an acrylic polymer B. Solution. The acrylic polymer B has a Mw of about 100×10 4 . (Acrylic Polymer C) In a reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux condenser, and a dropping funnel, BA 95 parts and AA 5 parts as a monomer component, and ethyl acetate as a polymerization solvent are added. 233 parts were stirred while introducing nitrogen gas for 2 hours. In this manner, after removing oxygen in the polymerization system, 0.2 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was added, and solution polymerization was carried out at 60 ° C for 8 hours to obtain an acrylic polymer. Solution. The acrylic polymer has a Mw of about 70×10 4 . <Preparation of the adhesive composition> (Example 1) The solution of the acrylic polymer A was added in two parts to 100 parts of the acrylic polymer A contained in the solution (nonvolatile content basis. The same applies hereinafter) Isocyanate-based cross-linking agent (trade name "Coronate L", a 75% ethyl acetate solution of trimethylolpropane/methylphenylene diisocyanate 3-mer adduct, manufactured by Tosoh Corporation; hereinafter referred to as "isocyanate" The crosslinking agent A") was stirred and mixed to prepare an adhesive composition of this example. (Example 2) In the solution of the acrylic polymer A, 2 parts of an isocyanate crosslinking agent A and 0.01 part of an epoxy crosslinking agent are added to 100 parts of the acrylic polymer A contained in the solution. "TETRAD-C" and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, manufactured by Mitsubishi Gas Chemical Co., Ltd.; hereinafter referred to as "epoxy crosslinking agent B") The mixture of the adhesives of this example was prepared by stirring and mixing. (Example 3) The solution of the acrylic polymer A was added with 2 parts of an isocyanate type crosslinking agent A and 0.035 part of the epoxy type crosslinking agent B with respect to 100 parts of the acrylic polymer A contained in the solution. And 10 parts of terpene phenol resin A (trade name "Tamanol 803L", manufactured by Arakawa Chemical Industry Co., Ltd., softening point about 145-160 ° C, hydroxyl value 1-20 mg KOH / g), stirring and mixing to prepare the adhesive of this example combination. (Example 4) In the solution of the acrylic polymer C, 2 parts of the isocyanate crosslinking agent A is added to 100 parts of the acrylic polymer C contained in the solution, and the mixture is stirred and mixed to prepare the adhesive of the present example. combination. (Example 5) In addition to 100 parts of the acrylic polymer C, 30 parts of terpene phenol resin B (manufactured by Anwar Chemical Co., Ltd., trade name "YS Polystar 2145"), a softening point of about 145 ° C, and a hydroxyl value of 70 were further added. The adhesive composition of this example was prepared in the same manner as in Example 4 except for -110 mgKOH/g. (Example 6) The adhesive composition of this example was prepared in the same manner as in Example 5 except that the amount of the terpene phenol resin B used in 100 parts of the acrylic polymer C was changed to 40 parts. (Example 7) In the solution of the acrylic polymer B, 2 parts of the isocyanate crosslinking agent A was added to 100 parts of the acrylic polymer B contained in the solution, and the mixture was stirred and mixed to prepare the adhesive of the present example. combination. (Example 8) The adhesive composition of this example was prepared in the same manner as in Example 4 except that the amount of the isocyanate crosslinking agent A used in 100 parts of the acrylic polymer C was changed to 1 part. (Example 9) In addition to 100 parts of the acrylic polymer C, 10 parts of rosin-based adhesion-providing resin A (trade name "Halitac SE10", hydrogenated rosin glyceride, manufactured by Halima Chemical Co., Ltd., softening point of about 80) was further added. The adhesive composition of this example was prepared in the same manner as in Example 4 except for °C. (Example 10) The solution of the acrylic polymer C is added with 2 parts of an isocyanate type crosslinking agent A and 0.01 part of an epoxy type crosslinking agent B with respect to 100 parts of the acrylic polymer C contained in the solution. 20 parts of rosin-based adhesive resin B (trade name "PENSEL D125", manufactured by Arakawa Chemical Industries Co., Ltd., polymerized rosin pentaerythritol ester, softening point of about 125 ° C) was stirred and mixed to prepare an adhesive composition of this example. <Preparation of Adhesive Sheet> As a release liner, two release films (trade name "DIAFOIL MRF", thickness: 38 μm, manufactured by Mitsubishi Polyester Co., Ltd.) having a single release surface of a release-treated release surface were prepared. Each of the adhesive compositions of the examples was applied to the release faces of the release liners, and dried at 100 ° C for 2 minutes to form an adhesive layer having a thickness of 19 μm. The adhesive layers formed on the two release liners were bonded to the first surface and the second surface of a transparent base film having a thickness of 12 μm to form a double-sided adhesive sheet having a total thickness of 50 μm. The release liner is directly left on the adhesive layer for protecting the surface (adhesive surface) of the adhesive layer. As the base film, a PET film (resin film) manufactured by Toray Industries, Inc., trade name "Lumirror" was used. In this manner, the double-sided adhesive sheets of Examples 1 to 10 corresponding to the adhesive compositions of Examples 1 to 10, respectively, were produced. <Evaluation Test> After the double-sided adhesive sheets of Examples 1 to 10 were cured in an environment of 50° C. and 50% RH for one day, the surface free energy γ, the gel fraction, and the adhesion maintaining ratio were determined by the above method. Further, the adhesive composition of Examples 1 to 10 was applied to the release surface of the polyester release film (trade name "DIAFOIL MRF", thickness: 38 μm, manufactured by Mitsubishi Polyester Co., Ltd.) at 120 ° C. In a minute, an adhesive layer (no substrate adhesive layer) having a thickness of 20 μm was formed on the release film. This adhesive layer was bonded to a PET film (trade name "Lumirror", manufactured by Toray Industries, Inc.) having a thickness of 50 μm, and cut into a square shape of 25 mm in length and 25 mm in width to prepare a test piece. Using this test piece, the oleic acid permeability evaluation was performed by the above method, thereby obtaining the oleic acid permeation amount and the penetration distance, and evaluating the overflow of the adhesive. The results obtained are shown in Tables 1 and 2. [Table 1] [Table 2] As shown in Tables 1 and 2, the surface free energy γ is less than 40 mJ/m. 2 And the adhesive sheets of Examples 1 to 6 in which the oleic acid permeation amount is in the range of 1.5 g/g or more and 5.0 g/g or less, exhibiting a good adhesive retention rate, and the adhesive overflow is less. . On the other hand, in Examples 10 and 8 in which the amount of oleic acid permeation was too small and Example 10 in which the surface free energy γ was too high, the adhesion retention rate was low. In Example 9 in which the oleic acid permeation amount was excessive, the overflow of the adhesive was large. The specific examples of the present invention have been described in detail above, but these are merely illustrative and are not intended to limit the scope of the application. The technology described in the patent application scope includes various modifications and changes to the specific examples described above.

1、2、3、4、5、6‧‧‧黏著片材
10‧‧‧基材
21、22‧‧‧黏著劑層
31、32‧‧‧剝離襯墊1, 2, 3, 4, 5, 6‧‧ ‧ adhesive sheets
10‧‧‧Substrate
21, 22‧‧‧ adhesive layer
31, 32‧‧‧ peeling liner

圖1係模式性表示黏著片材之一構成例之剖面圖。 圖2係模式性表示黏著片材之其他構成例之剖面圖。 圖3係模式性表示黏著片材之其他構成例之剖面圖。 圖4係模式性表示黏著片材之其他構成例之剖面圖。 圖5係模式性表示黏著片材之其他構成例之剖面圖。 圖6係模式性表示黏著片材之其他構成例之剖面圖。Fig. 1 is a cross-sectional view schematically showing a configuration example of an adhesive sheet. Fig. 2 is a cross-sectional view schematically showing another configuration example of the adhesive sheet. Fig. 3 is a cross-sectional view schematically showing another configuration example of the adhesive sheet. Fig. 4 is a cross-sectional view schematically showing another configuration example of the adhesive sheet. Fig. 5 is a cross-sectional view schematically showing another configuration example of the adhesive sheet. Fig. 6 is a cross-sectional view schematically showing another configuration example of the adhesive sheet.

1‧‧‧黏著片材 1‧‧‧Adhesive sheet

10‧‧‧基材 10‧‧‧Substrate

21、22‧‧‧黏著劑層 21, 22‧‧‧ adhesive layer

31、32‧‧‧剝離襯墊 31, 32‧‧‧ peeling liner

Claims (18)

一種黏著片材，其係具備由以丙烯酸系聚合物作為基礎聚合物之黏著劑構成之黏著劑層者， 上述黏著劑層之表面自由能量γ為未達40 mJ/m2 ，且每1 g之油酸滲透量為1.5 g以上且5.0 g以下。An adhesive sheet having an adhesive layer composed of an adhesive of an acrylic polymer as a base polymer, wherein the surface free energy γ of the adhesive layer is less than 40 mJ/m 2 and per 1 g The oleic acid permeation amount is 1.5 g or more and 5.0 g or less. 如請求項1之黏著片材，其中上述黏著劑層之凝膠分率為30%以上且70%以下。The adhesive sheet according to claim 1, wherein the adhesive layer has a gel fraction of 30% or more and 70% or less. 如請求項1或2之黏著片材，其中上述黏著劑層係使用包含上述丙烯酸系聚合物及交聯劑之黏著劑組合物而形成。The adhesive sheet according to claim 1 or 2, wherein the adhesive layer is formed using an adhesive composition comprising the acrylic polymer and a crosslinking agent. 如請求項3之黏著片材，其中上述交聯劑包含異氰酸酯系交聯劑。The adhesive sheet of claim 3, wherein the crosslinking agent comprises an isocyanate crosslinking agent. 如請求項1至4中任一項之黏著片材，其中上述黏著劑層包含黏著賦予樹脂， 上述黏著賦予樹脂之50重量%以上為松香系黏著賦予樹脂以外之黏著賦予樹脂。The adhesive sheet according to any one of claims 1 to 4, wherein the adhesive layer contains an adhesive-imparting resin, and 50% by weight or more of the adhesive-imparting resin is an adhesive-imparting resin other than the rosin-based adhesive-imparting resin. 如請求項1至5中任一項之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含多於50重量%之於酯末端具有碳原子數7以上且10以下之烷基的(甲基)丙烯酸烷基酯。The adhesive sheet according to any one of claims 1 to 5, wherein the monomer component constituting the acrylic polymer contains more than 50% by weight of an alkyl group having a carbon number of 7 or more and 10 or less at the ester terminal ( Alkyl methacrylate. 如請求項1至6中任一項之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含多於5重量%之含羧基之單體。The adhesive sheet according to any one of claims 1 to 6, wherein the monomer component constituting the above acrylic polymer contains more than 5% by weight of a carboxyl group-containing monomer. 如請求項1至7中任一項之黏著片材，其中 構成上述丙烯酸系聚合物之單體成分包含： 70重量%以上的於酯末端具有碳原子數7以上且10以下之烷基之(甲基)丙烯酸烷基酯、及 7重量%以上且15重量%以下的含羧基之單體。The adhesive sheet according to any one of claims 1 to 7, wherein the monomer component constituting the acrylic polymer comprises: 70% by weight or more of an alkyl group having 7 or more and 10 or less carbon atoms at the ester terminal ( A methyl methacrylate, and a carboxyl group-containing monomer of 7% by weight or more and 15% by weight or less. 如請求項8之黏著片材，其中上述於酯末端具有碳原子數7以上且10以下之烷基的(甲基)丙烯酸烷基酯包含選自由丙烯酸2-乙基己酯、丙烯酸異辛酯及丙烯酸異壬酯所組成之群中之1種或2種以上， 上述含羧基之單體為丙烯酸、甲基丙烯酸或該等之組合。The adhesive sheet according to claim 8, wherein the alkyl (meth)acrylate having an alkyl group having 7 or more and 10 or less carbon atoms at the ester terminal is selected from the group consisting of 2-ethylhexyl acrylate and isooctyl acrylate. And one or more of the group consisting of isodecyl acrylate, and the carboxyl group-containing monomer is acrylic acid, methacrylic acid or a combination thereof. 如請求項6至9中任一項之黏著片材，其中上述黏著劑層包含黏著賦予樹脂，該黏著賦予樹脂之50重量%以上為酚系黏著賦予樹脂。The adhesive sheet according to any one of claims 6 to 9, wherein the adhesive layer contains an adhesive-imparting resin, and 50% by weight or more of the adhesive-imparting resin is a phenol-based adhesive-imparting resin. 如請求項10之黏著片材，其中上述酚系黏著賦予樹脂包含羥值未達30 mgKOH/g之萜烯酚樹脂。The adhesive sheet of claim 10, wherein the phenolic adhesion-imparting resin comprises a terpene phenol resin having a hydroxyl value of less than 30 mgKOH/g. 如請求項1至5中任一項之黏著片材，其中構成上述丙烯酸系聚合物之單體成分包含多於50重量%之於酯末端具有碳原子數1以上且6以下之烷基的(甲基)丙烯酸烷基酯。The adhesive sheet according to any one of claims 1 to 5, wherein the monomer component constituting the acrylic polymer contains more than 50% by weight of an alkyl group having 1 or more and 6 or less carbon atoms at the ester terminal ( Alkyl methacrylate. 如請求項12之黏著片材，其中上述於酯末端具有碳原子數1以上且6以下之烷基的(甲基)丙烯酸烷基酯包含選自由丙烯酸正丁酯、丙烯酸乙酯及丙烯酸甲酯所組成之群中之1種或2種以上。The adhesive sheet of claim 12, wherein the alkyl (meth)acrylate having an alkyl group having 1 or more and 6 or less carbon atoms at the ester terminal is selected from the group consisting of n-butyl acrylate, ethyl acrylate and methyl acrylate. One or more of the group consisting of. 如請求項12或13之黏著片材，其中上述黏著劑層包含黏著賦予樹脂，該黏著賦予樹脂之50重量%以上為酚系黏著賦予樹脂。The adhesive sheet according to claim 12 or 13, wherein the adhesive layer contains an adhesive-imparting resin, and 50% by weight or more of the adhesive-imparting resin is a phenol-based adhesive-imparting resin. 如請求項14之黏著片材，其中上述酚系黏著賦予樹脂包含羥值為30 mgKOH/g以上之萜烯酚樹脂。The adhesive sheet according to claim 14, wherein the phenolic adhesion-imparting resin contains a terpene phenol resin having a hydroxyl value of 30 mgKOH/g or more. 如請求項1至15中任一項之黏著片材，其中上述黏著劑層之厚度為25 μm以下。The adhesive sheet according to any one of claims 1 to 15, wherein the thickness of the adhesive layer is 25 μm or less. 如請求項1至16中任一項之黏著片材，其以於基材之一個表面及另一表面具有上述黏著劑層之雙面黏著片材而構成。The adhesive sheet according to any one of claims 1 to 16, which is constituted by a double-sided adhesive sheet having the above-mentioned adhesive layer on one surface and the other surface of the substrate. 如請求項1至17中任一項之黏著片材，其於行動裝置中用於構件之固定。The adhesive sheet according to any one of claims 1 to 17, which is used for fixing the member in the mobile device.
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