JP7460553B2 - surface protection film - Google Patents

Description

The present invention relates to a surface protection film.

In the manufacturing process of optical components and electronic components, a surface protection film is generally attached to the exposed surface to prevent scratches on the surface during processing, assembly, inspection, transportation, etc. Such a surface protection film is peeled off from an optical member or an electronic member when surface protection is no longer necessary (Patent Document 1).

A surface protection film is sometimes subjected to high-temperature and high-pressure treatment using an autoclave or the like in order to bond the surface protection film to an adherend by pressure. After performing such high temperature and high pressure treatment, it is necessary to return the temperature to normal temperature and pressure.

However, conventional surface protection films have a problem in that they tend to generate bubbles when subjected to high temperature and high pressure treatment after being attached to an adherend and then returned to normal temperature and pressure. In particular, surface protection films that are designed to have a hard adhesive for applications that require easy removability are difficult to avoid due to fine air bubbles (typically However, there is a problem in that bubbles with a diameter of approximately several millimeters are likely to occur.

Therefore, surface protection films that can solve such problems have been proposed (Patent Documents 2 and 3).

The surface protection film described in Patent Document 2 has a problem in that it is difficult to peel and cannot be applied to applications that require easy peelability.

The surface protection film for polarizing plates described in Patent Document 3 aims to prevent tunnel-shaped lifting, and also does not have a sufficient level of easy peelability.

In particular, when the surface protective film is used to adhere to an adherend whose surface has a water contact angle of a certain level or more, the above-mentioned problem of bubble generation is noticeable.

Japanese Patent Application Publication No. 2016-17109 Japanese Patent Application Laid-Open No. 11-961 JP 2007-304317 A

The objective of the present invention is to provide a surface protection film that has high adhesive strength and easy peelability, and that can suppress the generation of air bubbles even when attached to an adherend (preferably an adherend with a surface water contact angle of a certain level or more), subjected to high temperature and high pressure treatment in an autoclave or the like, and then returned to room temperature and pressure.

The surface protection film of the present invention is
A surface protection film comprising an adhesive layer and a base layer,
When the free induction decay signal obtained by pulsed NMR measurement of the adhesive layer is separated into two components by the nonlinear least squares method, the component with a short relaxation time is called a hard component (S), and the component with a long relaxation time is called a soft component (S). L), the spin-spin relaxation time T2 (L) of protons in the soft component (L) measured at 30 _° C, and the spin-spin relaxation time T2 of protons in the soft component (L) measured at 60°C. The ratio T2(L) ₆₀ /T2(L) ₃₀ of (L) ₆₀ is 2.15 to 3.05,
Shear adhesive strength is 10 N/cm ² or more,
High-speed peeling force is 0.8 N/25 mm or less.

In one embodiment, the adhesive layer has a thickness of 1 μm to 500 μm.

In one embodiment, the thickness of the base layer is 1 μm to 500 μm.

In one embodiment, the adhesive layer is composed of an adhesive formed from an adhesive composition, and the adhesive composition comprises a (meth)acrylic copolymer (A) and a polyfunctional alcohol (C ) and a crosslinking agent (D).

In one embodiment, the (meth)acrylic copolymer (A) comprises (a1 component) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms; It is formed by polymerization from a composition (a) containing (component) a (meth)acrylic acid ester having an OH group.

In one embodiment, the composition (a) contains (meth)acrylic acid.

In one embodiment, the polyfunctional alcohol (C) has 3 to 6 functional groups.

In one embodiment, the number average molecular weight of the polyfunctional alcohol (C) is 50 to 10,000.

In one embodiment, the pressure-sensitive adhesive composition comprises (b1) a (meth)acrylic copolymer (B) formed by polymerization from a composition (b) containing a (meth)acrylic acid alkyl ester in which the alkyl group of the alkyl ester moiety is an alicyclic hydrocarbon group.

In one embodiment, the composition (b) contains (b2 component) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester portion has 1 to 3 carbon atoms.

In one embodiment, the composition (b) comprises a mercaptan.

In one embodiment, the Tg of the (meth)acrylic copolymer (B) is 50°C to 250°C.

In one embodiment, the weight average molecular weight of the (meth)acrylic copolymer (B) is 1,000 to 30,000.

In one embodiment, the adhesive composition contains an ionic liquid.

In one embodiment, the surface protective film of the present invention generates 10 or fewer bubbles after high temperature and high pressure treatment.

In one embodiment, the surface protection film of the present invention is used to protect the surface of an adherend having a water contact angle of 60 degrees or more.

According to the present invention, it is possible to provide a surface protection film that has high adhesive strength and easy peelability, and that can suppress the generation of air bubbles even when it is attached to an adherend (preferably an adherend whose surface has a water contact angle of a certain level or more) and then subjected to high-temperature, high-pressure treatment in an autoclave or the like, and then returned to room temperature and pressure.

1 is a schematic cross-sectional view of one embodiment of a surface protection film of the present invention. FIG. 2 is a schematic cross-sectional view showing a method for producing a polarizing plate (A) to be used for an adherend (A). It is a schematic sectional view showing the manufacturing method of the polarizer used for adherend (C).

When the term "weight" appears in this specification, it may be read as "mass," which is the commonly used SI unit of weight.

In this specification, the expression "(meth)acrylic" means "acrylic and/or methacrylic", and the expression "(meth)acrylate" means "acrylate and/or methacrylate". ”, the expression “(meth)allyl” means “allyl and/or methallyl”, and the expression “(meth)acrolein” means “acrolein and/or methacrolein”. It means "Rain".

<<Surface protection film>>
The surface protection film of the present invention includes a pressure-sensitive adhesive layer and a substrate layer.

The surface protection film of the present invention may be provided with any other appropriate member as long as it has a pressure-sensitive adhesive layer and a base layer, as long as the effect of the present invention is not impaired. Typically, the surface protection film of the present invention is composed of a base layer and a pressure-sensitive adhesive layer.

Figure 1 is a schematic cross-sectional view of a surface protection film according to one embodiment of the present invention. In Figure 1, the surface protection film 10 comprises a base layer 1 and an adhesive layer 2. In Figure 1, the base layer 1 and the adhesive layer 2 are directly laminated together.

In FIG. 1, the surface of the adhesive layer 2 opposite the base layer 1 may be provided with any suitable release liner (not shown) for protection etc. until use. Release liners include, for example, release liners whose surfaces are treated with silicone, such as paper or plastic films, and those whose surfaces are treated with polyolefin resin. Examples include laminated release liners. Examples of the plastic film as a liner base material include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, Examples include polyurethane film and ethylene-vinyl acetate copolymer film. The plastic film used as the liner base material is preferably a polyethylene film.

The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, even more preferably 5 μm to 400 μm, particularly preferably 10 μm to 300 μm.

The thickness of the surface protection film of the present invention is preferably 10 μm to 500 μm, more preferably 15 μm to 400 μm, even more preferably 20 μm to 350 μm, particularly preferably 25 μm to 300 μm, and most preferably 30 μm to 30 μm. It is 250 μm.

The surface protection film of the present invention is cut to a size of 10 mm in width and 100 mm in length, and after peeling off the separator, it is attached to an adherend having a surface water contact angle of 60 degrees or more (for example, an unsaponified TAC polarizing plate (width 70 mm, length 100 mm, water contact angle = ^69.9 degrees) obtained in Production Example 5 described later) so that the adhesive (bonding) area of the exposed adhesive layer is 1 cm2, and after leaving it to stand for 30 minutes in an environment of 23°C x 50% RH, it is peeled in the shear direction at a peeling speed of 0.06 mm/min. The maximum load (N/ ^cm2 ) at this time is defined as the shear adhesive strength, and the shear adhesive strength measured under the above conditions is preferably 10 N/ ^cm2 or more, more preferably 10 N/ ^cm2 to 80 N/ ^cm2 , even more preferably 10 N/ ^cm2 to 50 N/ ^cm2 , particularly preferably 15 N/ ^cm2 to 45 N/ ^cm2 , and most preferably 20 N/ ^cm2 to 40 N/cm2. ^When the shear adhesive strength is within the above range, the surface protective film of the present invention can exhibit high adhesive strength.

The surface protection film of the present invention is prepared by cutting the surface protection film into a size of 25 mm in width and 100 mm in length, and then peeling off the separator. The obtained unsaponified TAC polarizing plate (width 70 mm, length 100 mm, water contact angle = 69.9 degrees) was pressed onto the surface with a hand roller, and then pressed at 0.25 MPa and 0.3 m/min. Laminate and prepare an evaluation sample. Peel off the separator on the polarizing plate side of the evaluation sample, press it onto a glass slide with a thickness of 1.3 mm, width of 65 mm, and length of 165 mm using a hand roller, and place it in an environment of 23°C x 50% RH. After leaving it for 30 minutes, one end of the surface protection film was peeled off using a universal tensile tester in an environment of 23°C x 50% RH at a pulling speed of 30 m/min and a peeling angle of 180°. The high-speed peeling force measured under the above conditions is preferably 10N/25mm or less, more preferably 0.01N/25mm to 10N/25mm, and even more preferably 0.01N. /25mm to 5N/25mm, particularly preferably 0.05N/25mm to 3N/25mm, most preferably 0.05N/25mm to 2N/25mm. If the high-speed peeling force is within the above range, the surface protection film of the present invention can exhibit high easy peelability.

The surface protective film of the present invention is prepared by cutting the surface protective film to a size of 65 mm in width and 90 mm in length, peeling off the separator, and then pressing the film with a hand roller onto the surface of an adherend having a water contact angle of 60 degrees or more on the surface (for example, an unsaponified TAC polarizing plate (width 70 mm, length 100 mm, water contact angle = 69.9 degrees) obtained in Production Example 5 described later), laminating the film under pressing conditions of 0.25 MPa and 0.3 m/min, and cutting the four sides from the surface protective film side with a cutter to a width of 50 mm and a length of 80 mm to obtain an evaluation sample. The separator on the polarizing plate side is The film is peeled off, pressed with a hand roller onto a slide glass having a thickness of 1.3 mm, a width of 65 mm, and a length of 165 mm, and then left in an environment of 23° C.×50% RH for 30 minutes, and then autoclaved for 40 minutes in an environment of 50° C. and 5 atm, and then returned to room temperature and normal pressure. The number of bubbles generated at the end of the polarizing plate immediately after the autoclaving is counted to obtain the number of bubbles generated (number of bubbles generated after high temperature and high pressure treatment), and the number of bubbles generated is preferably 10 or less, more preferably 8 or less, even more preferably 5 or less, particularly preferably 3 or less, and most preferably 0. As described above, the surface protective film of the present invention can suppress the generation of bubbles even if it is attached to an adherend, subjected to high temperature and high pressure treatment such as an autoclave, and then returned to room temperature and normal pressure.

The surface protective film of the present invention can be produced by any suitable method. Examples of such a production method include
(1) A method of applying a solution or a hot melt of a material for forming the adhesive layer onto a base layer,
(2) A method of applying a solution or a hot melt of a material for forming an adhesive layer onto a separator to form an adhesive layer, and then transferring the adhesive layer onto a base layer;
(3) A method of forming and coating a material for forming a pressure-sensitive adhesive layer on a base layer by extrusion;
(4) A method of extruding a substrate layer and a pressure-sensitive adhesive layer in two layers or multiple layers,
(5) A method of laminating a single layer of a pressure-sensitive adhesive layer on a substrate layer, or a method of laminating a double layer of a pressure-sensitive adhesive layer together with a laminate layer,
(6) A method of laminating a pressure-sensitive adhesive layer and a base layer-forming material such as a film or a laminate layer in a two-layer or multi-layer manner,
The above-mentioned manufacturing method can be used in accordance with any suitable manufacturing method.

Coating methods that can be used include, for example, the roll coater method, the comma coater method, the die coater method, the reverse coater method, the silk screen method, and the gravure coater method.

<Adhesive layer>
The adhesive layer is composed of an adhesive formed from an adhesive composition. The adhesive layer can be produced by any suitable production method. For example, the adhesive composition is applied onto a substrate layer, and heated or dried as necessary to form an adhesive layer on the substrate layer. For example, the adhesive composition of the present invention can be applied onto a substrate layer by roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, extrusion coating using a die coater, etc.

The thickness of the adhesive layer is preferably 1 μm to 500 μm, more preferably 2 μm to 300 μm, even more preferably 3 μm to 200 μm, particularly preferably 4 μm to 150 μm, and most preferably 5 μm to 100 μm.

The adhesive composition preferably includes:
(1) An adhesive composition containing a (meth)acrylic copolymer (A), a polyfunctional alcohol (C), and a crosslinking agent (D),
(2) an adhesive composition containing a polyol and a polyfunctional isocyanate;
At least one selected from the following is mentioned.

An acrylic adhesive can be obtained from the above (1), and a urethane adhesive can be obtained from the above (2).

The adhesive composition more preferably contains a (meth)acrylic copolymer (A), a polyfunctional alcohol (C) and a crosslinking agent (D).

The adhesive layer is preferably formed by causing the adhesive composition to undergo a characteristic crosslinking reaction. Specifically, from the results of various studies, it has been found that by containing the polyfunctional alcohol (C) in the adhesive composition, the polyfunctional alcohol (C) and the crosslinking agent (D) are combined, and a specific type of It is presumed that this imparts a characteristic highly crosslinked structure to the (meth)acrylic copolymer (A) obtained from the composition containing the essential monomer component. As a result, the adhesive layer has high adhesive strength and high easy releasability, and the surface protection film of the present invention having the adhesive layer is subjected to high temperature and high pressure treatment in an autoclave etc. after being attached to an adherend. It is presumed that even if the temperature and pressure are returned to normal temperature and pressure after that, the generation of bubbles can be suppressed.

Furthermore, when designing the adhesive layer (or the adhesive constituting it) of the surface protection film of the present invention to have the characteristic highly crosslinked structure as described above, it has been found that by incorporating a characteristic (meth)acrylic copolymer (B) as described below into the adhesive composition, the increase in adhesive strength over time can be effectively suppressed and better easy peelability can be achieved.

The fact that the adhesive layer has a highly crosslinked structure can be observed from several viewpoints. These viewpoints include, for example, relaxation times observed by pulsed NMR.

Since the reciprocal of the spin-spin relaxation time and the crosslinking density of the polymer (degree of restraint of molecular motion) show a positive linear correlation, the spin-spin relaxation time T2 is an index of the crosslinking density of the polymer component constituting the adhesive layer. It can be. Specifically, when pulsed NMR of a polymer is measured, spin-spin relaxation times T2 of one or more components (for example, 2 or 3) are obtained, and the magnitude of the spin-spin relaxation times T2 determines the size of the adhesive layer. Corresponds to high or low crosslinking density of polymer components. Regarding the method of dividing components according to the magnitude of the spin-spin relaxation time, the components are divided by the nonlinear square method, and if the analysis residue (offset) is less than 10%, it can be judged to be appropriate as a resolution. When separated into two components, the component with high crosslinking density is the S component, the component with low crosslinking density is the L component, and the respective spin-spin relaxation times are T2(S) and T2(L). The spin-spin relaxation time T2(S) of the polymer component S with high density may be small, and the pin-spin relaxation time T2(L) of the polymer component L with low crosslink density may be large.

When the free induction decay signal obtained by pulsed NMR measurement of the adhesive layer is separated into two components by the nonlinear least squares method, the component with a short relaxation time is called a hard component (S), and the component with a long relaxation time is called a soft component (L). ), the proton spin-spin relaxation time T2 (L) of the soft component (L) measured at ₃₀ °C, and the spin-spin relaxation time T2 (L) of the proton of the soft component (L) measured at 60°C. The ratio T2(L) ₆₀ /T2(L) ₃₀ of L) ₆₀ is preferably 1 or more, more preferably 1 to 5, even more preferably 1.5 to 4, particularly preferably 2 to 3.5, most preferably 2.15-3.

The T2(L) ₃₀ is preferably 500 μsec to 5000 μsec, more preferably 700 μsec to 4000 μsec, further preferably 800 μsec to 3000 μsec, particularly preferably 900 μsec to 2500 μsec, and most preferably 1000 μsec to 2300 μsec.

The T2(L) ₆₀ is preferably 500 μsec to 9000 μsec, more preferably 1000 μsec to 8000 μsec, further preferably 1500 μsec to 7000 μsec, particularly preferably 2000 μsec to 6500 μsec, and most preferably 2500 μsec to 6000 μsec.

The fact that the adhesive layer has a highly cross-linked structure may be reflected in the swelling degree. When the adhesive layer has a highly cross-linked structure, the swelling degree of the adhesive layer is preferably 250% or less, more preferably 80% to 250%, even more preferably 85% to 240%, particularly preferably 90% to 235%, and most preferably 95% to 230%.

The degree of swelling can be measured, for example, by the following method: About 0.1 g of the polymer after the crosslinking reaction is sampled, wrapped in a porous tetrafluoroethylene sheet (trade name "NTF1122", manufactured by Nitto Denko Corporation) having an average pore size of 0.2 μm, and then tied with string, and the weight at that time is measured and used as the weight before immersion (total weight of the polymer, tetrafluoroethylene sheet, and string), and the total weight of the tetrafluoroethylene sheet and string is also measured and used as the wrapping weight. Next, the above polymer is wrapped in a tetrafluoroethylene sheet and tied with string (referred to as the "sample"), placed in a 50 ml container filled with ethyl acetate and allowed to stand at 23°C for 7 days. Thereafter, the sample after immersion in ethyl acetate is removed from the container, the ethyl acetate adhering to the sample is thoroughly wiped off with a rag, and the weight is measured, which is the post-immersion weight. The sample is then transferred to an aluminum cup and dried in a dryer at 130°C for 2 hours. After the ethyl acetate is removed, the weight is measured and this weight is the post-drying weight. The swelling degree can then be calculated from the following formula:
Swelling degree (%) = (a-b) / (c-b) × 100 (1)
In the formula (1), a is the weight after immersion, b is the package weight, and c is the weight after drying.
Furthermore, when collecting the crosslinked polymer, it may be collected from the pressure-sensitive adhesive layer surface of the surface protection film, or it may be collected from a silicone separator or the like on which the same pressure-sensitive adhesive layer as that provided on the surface protection film has been separately applied and dried.

≪Adhesive composition≫
The adhesive composition contains a (meth)acrylic copolymer (A). The number of (meth)acrylic copolymers (A) may be one, or two or more.

The content of (meth)acrylic copolymer (A) in the adhesive composition is preferably 50% by weight to 99.9% by weight, more preferably 60% by weight to 99.5% by weight, even more preferably 70% by weight to 99% by weight, particularly preferably 80% by weight to 99% by weight, and most preferably 85% by weight to 99% by weight, in order to better express the effects of the present invention.

The adhesive composition contains a polyfunctional alcohol (C). The number of polyfunctional alcohols (C) may be one, or two or more.

The content of the polyfunctional alcohol (C) in the adhesive composition may be any appropriate content within the range that does not impair the effects of the present invention. In terms of being able to more effectively express the effects of the present invention, the content is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 7 parts by weight, even more preferably 0.1 to 5 parts by weight, and particularly preferably 0.2 to 3 parts by weight, relative to the solid content (100 parts by weight) of the (meth)acrylic copolymer (A).

The adhesive composition contains a crosslinking agent (D). The number of crosslinking agents (D) may be one, or two or more.

The content of the crosslinking agent (D) in the adhesive composition may be any suitable content within a range that does not impair the effects of the present invention. Such a content is preferably 0.01 part by weight based on the solid content (100 parts by weight) of the (meth)acrylic copolymer (A) in order to better express the effects of the present invention. -50 parts by weight, more preferably 0.01 parts by weight - 30 parts by weight, still more preferably 0.01 parts by weight - 20 parts by weight, particularly preferably 0.01 parts by weight - 10 parts by weight. be.

The adhesive composition contains a (meth)acrylic copolymer (A), a polyfunctional alcohol (C), and a crosslinking agent (D), and may contain any other appropriate components within a range that does not impair the effects of the present invention. Such other components may be only one type, or two or more types.

The adhesive composition may be prepared by blending its components by any suitable method.

<(Meth)acrylic copolymer (A)>
As the (meth)acrylic copolymer (A), any appropriate (meth)acrylic copolymer can be adopted as long as the effects of the present invention are not impaired.

The weight average molecular weight of the (meth)acrylic copolymer (A) is preferably 100,000 to 5,000,000, more preferably 200,000 to 4,000,000, even more preferably 250,000 to 3,500,000, and particularly preferably 300,000 to 3,000,000, in order to better express the effects of the present invention.

As the (meth)acrylic copolymer (A), in terms of being able to more effectively exert the effects of the present invention, it is preferable that the (meth)acrylic copolymer (A) is formed by polymerization from a composition (a) containing (a1 component) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester portion has 4 to 12 carbon atoms, and (a2 component) a (meth)acrylic acid ester having an OH group.

(A1 component) may be only one type, or may be two or more types. (A2 component) may be only one type, or may be two or more types.

Examples of the (meth)acrylic acid alkyl ester (a1 component) in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms include n-butyl (meth)acrylate, isobutyl (meth)acrylate, and (meth)acrylate. s-Butyl acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-(meth)acrylate Ethylhexyl, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate Examples include. Among these, 2-ethylhexyl (meth)acrylate is preferred, and 2-ethylhexyl acrylate (2EHA) is more preferred, since it can more effectively exhibit the effects of the present invention.

(meth)acrylic acid alkyl ester (component a1) in which the alkyl group in the alkyl ester portion has 4 to 12 carbon atoms based on the total amount (100% by weight) of the monomer components constituting the (meth)acrylic copolymer (A) The content ratio is preferably 50% to 99.9% by weight, more preferably 60% to 99.9% by weight, and even more preferably 70% by weight, in terms of further expressing the effects of the present invention. % to 99.9% by weight, particularly preferably 80% to 99.9% by weight, most preferably 85% to 99.9% by weight.

Examples of the (meth)acrylic acid ester having an OH group (component a2) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and the like. ) acrylic esters, etc. Among these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, and 2-hydroxybutyl (meth)acrylate is more preferred, in that they can better express the effects of the present invention. These include ethyl (HEA) and 4-hydroxybutyl acrylate (4HBA), particularly preferably 4-hydroxybutyl acrylate (4HBA).

The content ratio of the (meth)acrylic acid ester having an OH group (component a2) relative to the total amount (100% by weight) of the monomer components constituting the (meth)acrylic copolymer (A) is preferably 0.1% by weight to 50% by weight, more preferably 0.1% by weight to 40% by weight, even more preferably 0.2% by weight to 30% by weight, particularly preferably 0.5% by weight to 20% by weight, and most preferably 1% by weight to 10% by weight, in order to better express the effects of the present invention.

Composition (a) may contain copolymerizable monomers other than (component a1) and (component a2). The number of copolymerizable monomers may be one, or two or more.

Composition (a) may contain (meth)acrylic acid as a copolymerizable monomer. The (meth)acrylic acid may be at least one selected from the group consisting of acrylic acid and methacrylic acid, and acrylic acid is preferred in that it can further exert the effects of the present invention.

The content of (meth)acrylic acid relative to the total amount (100% by weight) of monomer components constituting the (meth)acrylic copolymer (A) is preferably 0% by weight to 10% by weight, more preferably 0% by weight to 8% by weight, even more preferably 0% by weight to 5% by weight, particularly preferably 0% by weight to 2% by weight, and most preferably 0% by weight to 1% by weight, in order to better exhibit the effects of the present invention.

Examples of copolymerizable monomers other than (meth)acrylic acid include itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and acid anhydrides thereof (for example, acid anhydrides such as maleic anhydride and itaconic anhydride). monomers containing carboxyl groups (excluding (meth)acrylic acid); (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl Amide group-containing monomers such as (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide; (meth)aminoethyl acrylate, dimethylaminoethyl (meth)acrylate, (meth)acrylic Amino group-containing monomers such as t-butylaminoethyl acid; Epoxy group-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl- Heterocycle-containing vinyl monomers such as 2-pyrrolidone, (meth)acryloylmorpholine, N-vinylpiperidone, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, vinyloxazole; sodium vinylsulfonate Sulfonic acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; phosphoric acid group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate; cyclopentyl ( (Meth)acrylic acid esters having alicyclic hydrocarbon groups such as meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentadienyl (meth)acrylate; phenyl (meth)acrylate, phenoxyethyl (meth)acrylic acid esters having aromatic hydrocarbon groups such as (meth)acrylate and benzyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene; ethylene, Examples include olefins and dienes such as butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ether; and vinyl chloride.

As the copolymerizable monomer, polyfunctional monomers may also be employed. The polyfunctional monomer refers to a monomer having two or more ethylenically unsaturated groups in one molecule. As the ethylenically unsaturated group, any suitable ethylenically unsaturated group may be employed as long as the effects of the present invention are not impaired. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as a vinyl group, a propenyl group, an isopropenyl group, a vinyl ether group (vinyloxy group), and an allyl ether group (allyloxy group). Examples of polyfunctional monomers include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and neopentyl glycol. Di(meth)acrylate, Pentaerythritol di(meth)acrylate, Pentaerythritol tri(meth)acrylate, Dipentaerythritol hexa(meth)acrylate, Trimethylolpropane tri(meth)acrylate, Tetramethylolmethane tri(meth)acrylate, Allyl Examples include (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, and urethane acrylate. The number of such polyfunctional monomers may be one, or two or more.

As the copolymerizable monomer, (meth)acrylic acid alkoxyalkyl esters may also be used. Examples of (meth)acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. The (meth)acrylic acid alkoxyalkyl esters may be of one type or two or more types.

Composition (a) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include a polymerization initiator, a chain transfer agent, and a solvent. The content of these other components may be any appropriate content as long as the effects of the present invention are not impaired.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator (photoinitiator), or the like may be employed depending on the type of polymerization reaction. The number of polymerization initiators may be one, or two or more.

A thermal polymerization initiator may preferably be employed when obtaining an acrylic polymer by solution polymerization. Examples of such thermal polymerization initiators include azo polymerization initiators, peroxide polymerization initiators (e.g., dibenzoyl peroxide, tert-butyl permaleate, etc.), redox polymerization initiators, and the like. . Among these thermal polymerization initiators, the azo polymerization initiator disclosed in JP-A No. 2002-69411 is particularly preferred. Such an azo polymerization initiator is preferable in that decomposition products of the polymerization initiator are unlikely to remain in the acrylic polymer as a portion that causes generation of gas generated by heating (outgas). Examples of azo polymerization initiators include 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as AIBN) and 2,2'-azobis-2-methylbutyronitrile (hereinafter sometimes referred to as AMBN). ), dimethyl 2,2'-azobis(2-methylpropionate), and 4,4'-azobis-4-cyanovaleric acid. The amount of the azo polymerization initiator used is preferably 0.001 part by weight to 1 part by weight based on the total amount (100 parts by weight) of the monomer components constituting the (meth)acrylic copolymer (A), More preferably 0.005 parts by weight to 1 part by weight, still more preferably 0.005 parts by weight to 0.8 parts by weight, particularly preferably 0.01 parts by weight to 0.8 parts by weight, and most preferably 0.005 parts by weight to 0.8 parts by weight. Preferably it is 0.01 part by weight to 0.7 part by weight.

The photopolymerization initiator may be preferably used when obtaining the (meth)acrylic copolymer (A) by active energy ray polymerization. Examples of the photopolymerization initiator include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators.

Examples of benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether. Examples of acetophenone-based photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4-(t-butyl)dichloroacetophenone. Examples of α-ketol-based photopolymerization initiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. Examples of aromatic sulfonyl chloride-based photopolymerization initiators include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of benzoin-based photopolymerization initiators include benzoin. Examples of benzyl-based photopolymerization initiators include benzyl. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include benzyl dimethyl ketal. Examples of thioxanthone-based photopolymerization initiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

The amount of photopolymerization initiator used is preferably 0.001 to 10 parts by weight, more preferably 0.005 to 8 parts by weight, even more preferably 0.01 to 5 parts by weight, particularly preferably 0.02 to 5 parts by weight, and most preferably 0.05 to 3 parts by weight, relative to the total amount (100 parts by weight) of the monomer components constituting the (meth)acrylic copolymer (A).

Methods for obtaining the (meth)acrylic copolymer (A) include, for example, solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and other synthetic methods for (meth)acrylic copolymers. Various known polymerization methods can be employed as appropriate.

<Polyfunctional Alcohol (C)>
As the polyfunctional alcohol (C), any appropriate polyfunctional alcohol can be adopted as long as it does not impair the effects of the present invention.

The number of functional groups of the polyfunctional alcohol (C) is preferably 2 or more, more preferably 3 to 6, still more preferably 3 to 5, and especially Preferably it is 3 to 4, most preferably 3.

Examples of the polyfunctional alcohol (C) include polyether polyols and polyester polyols.

Examples of polyether polyols include polypropylene glycol (bifunctional), diol (bifunctional) made by adding propylene oxide to bisphenol A, triol (trifunctional) made by adding propylene oxide to glycerin, and propylene oxide added to trimethylolpropane. (trifunctional), tetraol (tetrafunctional), which has propylene oxide added to the active hydrogen of ethylenediamine, polyol (polyfunctional), which has propylene oxide added to sorbitol or sucrose, and propylene oxide and glycerin. Triol (trifunctional) which is a triol to which ethylene oxide is added and whose terminal is blocked by ethylene oxide, Tetraol which is a triol which is the addition of propylene oxide and ethylene oxide to the active hydrogen of ethylenediamine and whose terminal is blocked by ethylene oxide. polypropylene polyethylene glycol (bifunctional), which is polypropylene polyethylene glycol whose ends are blocked with ethylene oxide, and diol in which propylene oxide and ethylene oxide are added to bisphenol A, whose ends are blocked with ethylene oxide. diol (bifunctional), triol (trifunctional) made by adding ethylene oxide to trimethylolpropane, polypropylene polyethylene glycol (bifunctional) made by adding ethylene oxide and propylene oxide randomly to polypropylene polyethylene glycol, propylene oxide and glycerin Examples include a triol to which ethylene oxide is added, which is a triol to which ethylene oxide and propylene oxide are randomly added (trifunctional), and a flame-retardant polyol (bifunctional).

Commercially available polyether polyols include, for example, ADEKA Polyol manufactured by ADEKA Co., Ltd. (for example, P series, BPX series, G series, T series, EDP series, SP series, SC series, R series, RD series, AM series, BM series, CM series, EM series, GM series, PR series, GR series, flame retardant polyols, etc.), polyols of Sanyo Chemical Industries, Ltd. (for example, Sannix GP series, Sannix PP series, Sannix TP-400 series) , Sunnix SP-750 series, Sunnix PL-2100/PP series, SunEstar series, Primepole series, Newport series, Melpole series, PEG series, Macrogol series, etc.).

As the polyether polyol, in terms of the effect of the present invention being more effectively exhibited, a triol (trifunctional) in which propylene oxide is added to glycerin, a triol (trifunctional) in which propylene oxide is added to trimethylolpropane, a triol (trifunctional) in which propylene oxide and ethylene oxide are added to glycerin, the terminals of which are blocked with ethylene oxide, a triol (trifunctional) in which ethylene oxide is added to trimethylolpropane, a triol (trifunctional) in which propylene oxide and ethylene oxide are added to glycerin, the terminals of which are blocked with ethylene oxide, and a triol (trifunctional) in which propylene oxide and ethylene oxide are added to glycerin. and a triol (trifunctional) in which pyrene oxide is added randomly to glycerin, more preferably a triol (trifunctional) in which propylene oxide is added to glycerin, a triol (trifunctional) in which propylene oxide and ethylene oxide are added to glycerin and the ends are blocked with ethylene oxide, and a triol (trifunctional) in which propylene oxide and ethylene oxide are added to glycerin and the ethylene oxide and propylene oxide are added randomly, and even more preferably a triol (trifunctional) in which propylene oxide is added to glycerin.

Examples of the polyester polyol include polyester polyols obtained by reacting an acid component and a glycol component. Examples of the acid component include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, and trimellitic acid. Examples of glycol components include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, Examples include polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, and polyol components such as glycerin, trimethylolpropane, and pentaerythritol. Other examples of the polyester polyol (a1) include polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

Commercially available examples of polyester polyols include ADEKA New Ace from ADEKA Corporation (e.g., F18-62, F7-67, Y9-10, Y4-5, Y52-13, Y52-21, V14-90, YG-108, F1212-29, #50, Y65-55, YT-101, YT-651, NS-2400, etc.).

The number average molecular weight of the polyfunctional alcohol (C) is preferably 50 to 10,000, more preferably 60 to 5,000, and still more preferably 70 to 2,500, in that the effects of the present invention can be more fully expressed. Particularly preferably 75 to 2,000, most preferably 80 to 1,000.

<Crosslinking Agent (D)>
As the crosslinking agent (D), any appropriate crosslinking agent can be adopted as long as it does not impair the effects of the present invention.

Examples of the crosslinking agent (D) include polyfunctional isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, and metal chelate crosslinking agents. , metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, and the like. Among these, at least one type selected from the group consisting of polyfunctional isocyanate crosslinking agents and epoxy crosslinking agents is preferable in that it can better express the effects of the present invention.

Examples of polyfunctional isocyanate crosslinking agents include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylene diisocyanate; and aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of polyfunctional isocyanate crosslinking agents include commercially available products such as trimethylolpropane/tolylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate L"), trimethylolpropane/hexamethylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate HL"), product name "Coronate HX" (manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane/xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, Inc., product name "Takenate 110N"), and product name "Takenate 600" (manufactured by Mitsui Chemicals, Inc.).

Examples of epoxy crosslinking agents (multifunctional epoxy compounds) include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, and ethylene glycol diglycidyl ether. Examples of the epoxy crosslinking agent include diglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of the epoxy crosslinking agent include commercially available products such as "Tetrad C" (manufactured by Mitsubishi Gas Chemical Company, Inc.).

<(meth)acrylic copolymer (B)>
The adhesive composition is a composition (b1 component) containing a (meth)acrylic acid alkyl ester in which the alkyl group of the alkyl ester moiety is an alicyclic hydrocarbon group, in that the effects of the present invention can be further expressed. ) may also contain a (meth)acrylic copolymer (B) formed by polymerization. The number of (meth)acrylic copolymers (B) may be one, or two or more.

The content of the (meth)acrylic copolymer (B) in the adhesive composition may be any appropriate content within a range that does not impair the effects of the present invention. Such a content is preferably 0.01 part by weight based on the solid content (100 parts by weight) of the (meth)acrylic copolymer (A) in order to better express the effects of the present invention. -30 parts by weight, more preferably 0.01 parts by weight - 20 parts by weight, still more preferably 0.01 parts by weight - 10 parts by weight, particularly preferably 0.01 parts by weight - 5 parts by weight. be.

The (meth)acrylic copolymer (B) is formed by polymerization from a composition (b) containing a (meth)acrylic acid alkyl ester in which the alkyl group of the alkyl ester portion (b1 component) is an alicyclic hydrocarbon group. be done.

(B1 component) may be only one type or two or more types.

Examples of (meth)acrylic acid alkyl esters (component b1) in which the alkyl group of the alkyl ester moiety is an alicyclic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, Examples include cyclopentadienyl (meth)acrylate, and dicyclopentadienyl (meth)acrylate is preferred, and dicyclopentadienyl methacrylate is more preferred since the effects of the present invention can be more fully expressed. It is.

The content of (meth)acrylic acid alkyl ester (b1 component) in which the alkyl group of the alkyl ester portion is an alicyclic hydrocarbon group relative to the total amount (100% by weight) of the monomer components constituting the (meth)acrylic copolymer (B) is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 20% by weight or more, particularly preferably 30% by weight or more, and most preferably 30 to 99.9% by weight, in order to better express the effects of the present invention.

The composition (b) contains a copolymerizable monomer other than the component (b1). The copolymerizable monomer may be one type or two or more types.

In order to further exert the effects of the present invention, it is preferable that composition (b) contains, as a copolymerizable monomer, a (meth)acrylic acid alkyl ester (component b2) in which the alkyl group in the alkyl ester portion has 1 to 3 carbon atoms.

Examples of (meth)acrylic acid alkyl esters (component b2) in which the alkyl group in the alkyl ester portion has 1 to 3 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. In terms of being able to further exert the effects of the present invention, the (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester portion has 1 to 3 carbon atoms is preferably methyl (meth)acrylate, and more preferably methyl methacrylate.

The content of (meth)acrylic acid alkyl ester (component b2) in which the alkyl group in the alkyl ester portion has 1 to 3 carbon atoms relative to the total amount (100% by weight) of the monomer components constituting the (meth)acrylic copolymer (B) is preferably 10% by weight to 90% by weight, more preferably 15% by weight to 85% by weight, even more preferably 20% by weight to 80% by weight, particularly preferably 25% by weight to 75% by weight, and most preferably 30% by weight to 70% by weight, in order to better exhibit the effects of the present invention.

Examples of copolymerizable monomers other than (meth)acrylic acid alkyl ester (component b2) in which the alkyl group in the alkyl ester moiety has 1 to 3 carbon atoms include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, Carboxyl group-containing monomers such as acid, crotonic acid, isocrotonic acid, and their acid anhydrides (for example, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride); (meth)hydroxyethyl acrylate, (meth)acrylate (Meth)acrylic acid esters having an OH group such as hydroxypropyl acrylate and hydroxybutyl (meth)acrylate; (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-methylol (meth)acrylamide, N- Amide group-containing monomers such as methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide; aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, (meth)acrylate; ) Amino group-containing monomers such as t-butylaminoethyl acrylate; Epoxy group-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N- Heterocycle-containing vinyl monomers such as vinyl-2-pyrrolidone, (meth)acryloylmorpholine, N-vinylpiperidone, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, vinyloxazole; vinyl sulfone Sulfonic acid group-containing monomers such as sodium acid; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate; (meth)acrylic acid esters having alicyclic hydrocarbon groups such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentadienyl (meth)acrylate; phenyl (meth)acrylate; (meth)acrylic acid esters having an aromatic hydrocarbon group such as phenoxyethyl (meth)acrylate and benzyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene; Examples include olefins and dienes such as ethylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ether; and vinyl chloride.

As the copolymerizable monomer, polyfunctional monomers may also be employed. The polyfunctional monomer refers to a monomer having two or more ethylenically unsaturated groups in one molecule. As the ethylenically unsaturated group, any suitable ethylenically unsaturated group may be employed as long as the effects of the present invention are not impaired. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as a vinyl group, a propenyl group, an isopropenyl group, a vinyl ether group (vinyloxy group), and an allyl ether group (allyloxy group). Examples of polyfunctional monomers include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and neopentyl glycol. Di(meth)acrylate, Pentaerythritol di(meth)acrylate, Pentaerythritol tri(meth)acrylate, Dipentaerythritol hexa(meth)acrylate, Trimethylolpropane tri(meth)acrylate, Tetramethylolmethane tri(meth)acrylate, Allyl Examples include (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, and urethane acrylate. The number of such polyfunctional monomers may be one, or two or more.

As the copolymerizable monomer, (meth)acrylic acid alkoxyalkyl esters may also be used. Examples of (meth)acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. The (meth)acrylic acid alkoxyalkyl esters may be of one type or two or more types.

Composition (b) preferably contains a mercaptan as a chain transfer agent, in that the effects of the present invention can be more effectively achieved. Examples of mercaptans include alkyl thioglycolates, such as methyl thioglycolate and ethyl thioglycolate.

The content of the chain transfer agent in the composition (b) may be any appropriate content within a range that does not impair the effects of the present invention. Such a content is preferably 0.000% based on the total amount (100 parts by weight) of the monomer components constituting the (meth)acrylic copolymer (B), in order to further enhance the effects of the present invention. 01 parts by weight to 25 parts by weight, more preferably 0.02 parts to 20 parts by weight, still more preferably 0.05 parts to 15 parts by weight, particularly preferably 0.1 parts by weight to 15 parts by weight. Parts by weight.

The Tg of the (meth)acrylic copolymer (B) is preferably 50°C to 250°C, more preferably 70°C to 230°C, even more preferably 80°C to 220°C, particularly preferably 90°C to 210°C, and most preferably 100°C to 200°C, in order to better express the effects of the present invention.

The Tg of the (meth)acrylic copolymer (B) is the Tg of the homopolymer of each monomer constituting the (meth)acrylic copolymer (B) and the weight fraction of the monomer ( A value determined from the Fox formula based on the weight-based copolymerization ratio. The Fox equation, as shown below, is a relational equation between Tg of a copolymer and the glass transition temperature Tgi of a homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer.
1/Tg=Σ(Wi/Tgi)

In the above Fox equation, Tg is the glass transition temperature of the copolymer (unit: K), Wi is the weight fraction of monomer i in the copolymer (copolymerization ratio on a weight basis), and Tgi is the homopolymer of monomer i. represents the glass transition temperature (unit: K) of As the Tg of the homopolymer, the value described in publicly known materials shall be adopted.

As the Tg of the homopolymer, for example, the following values can be specifically used:
Dicyclopentadienyl methacrylate 175℃
Methyl methacrylate 105℃

For the Tg of homopolymers other than those exemplified above, the values described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be used. If multiple numerical values are listed in the above "Polymer Handbook", the conventional value is used. For monomers not listed in the above "Polymer Handbook", the catalog values of monomer manufacturing companies are used. For the Tg of a homopolymer of a monomer that is not listed in the above-mentioned "Polymer Handbook" and for which the catalog value of the monomer manufacturing company is not provided, the value obtained by the measurement method described in JP-A No. 2007-51271 shall be used. do.

The weight average molecular weight of the (meth)acrylic copolymer (B) is preferably 1,000 to 30,000, more preferably 1,250 to 25,000, even more preferably 1,500 to 20,000, particularly preferably 2,000 to 15,000, and most preferably 2,000 to 10,000, in order to better express the effects of the present invention.

Composition (b) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include a polymerization initiator, a chain transfer agent, and a solvent. The content of these other components may be any appropriate content as long as the effects of the present invention are not impaired. For details of these, the explanation in the section on (meth)acrylic copolymer (A) may be used.

Examples of methods for obtaining the (meth)acrylic copolymer (B) include solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and other synthetic methods for (meth)acrylic copolymers. Various known polymerization methods can be employed as appropriate.

<Ionic liquid>
The adhesive composition may contain an ionic liquid. By including the ionic liquid in the adhesive composition, it is possible to provide an adhesive composition with excellent antistatic properties. The number of such ionic liquids may be one, or two or more.

In the present invention, ionic liquid means a molten salt (ionic compound) that is liquid at 25°C.

The ionic liquid is preferably an ionic liquid containing a fluoroorganic anion. The ionic liquid containing a fluoroorganic anion is preferably an ionic liquid composed of a fluoroorganic anion and an onium cation. By employing an ionic liquid composed of a fluoroorganic anion and an onium cation as the ionic liquid, it is possible to provide a pressure-sensitive adhesive composition with extremely excellent antistatic properties.

As the onium cation that can constitute the ionic liquid, any suitable onium cation may be employed as long as the effects of the present invention are not impaired. Such onium cations are preferably at least one selected from nitrogen-containing onium cations, sulfur-containing onium cations, and phosphorus-containing onium cations. By selecting these onium cations, it is possible to provide a pressure-sensitive adhesive composition with extremely excellent antistatic properties.

The onium cation capable of constituting the ionic liquid is preferably at least one selected from the cations having structures represented by the general formulas (1) to (5).

In the general formula (1), Ra represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a heteroatom, and Rb and Rc are the same or different and are hydrogen or a carbon group having 1 to 16 carbon atoms. It represents a hydrogen group and may contain a hetero atom. However, if the nitrogen atom contains a double bond, Rc is absent.

In general formula (2), Rd represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Re, Rf, and Rg are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms and may contain a heteroatom.

In general formula (3), Rh represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Ri, Rj, and Rk are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms and may contain a heteroatom.

In the general formula (4), Z represents a nitrogen atom, a sulfur atom, or a phosphorus atom, and Rl, Rm, Rn, and Ro are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms, and a hetero May contain atoms. However, when Z is a sulfur atom, Ro is not present.

In general formula (5), X represents a Li atom, a Na atom, or a K atom.

Examples of cations represented by general formula (1) include pyridinium cations, pyrrolidinium cations, piperidinium cations, cations having a pyrroline skeleton, and cations having a pyrrole skeleton.

Specific examples of the cation represented by general formula (1) include 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, and 1-butylpyridinium cation. -3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, Pyridinium cations such as 1,1-dimethylpyrrolidinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-Methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1 -Ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium cation, 1 , 1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation; 1-propylpiperidinium cation, 1-pentylpyrrolidinium cation; Peridinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation Cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation , 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-propyl-1-butylpiperidinium cation, Piperidinium cations such as 1,1-dimethylpiperidinium cation, 1,1-dipropylpiperidinium cation, 1,1-dibutylpiperidinium cation; 2-methyl-1-pyrroline cation; 1-ethyl- Examples include 2-phenylindole cation; 1,2-dimethylindole cation; 1-ethylcarbazole cation; and the like.

Among these, in terms of the ability to further manifest the effects of the present invention, preferred are pyridinium cations such as 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, and 1-octyl-4-methylpyridinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1-methylpyridinium cation, and 1-ethyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium cation pyrrolidinium cations such as 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pent ...pentylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl- piperidinium cations such as 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, and 1-propyl-1-butylpiperidinium cation; and more preferably, the 1-hexylpyridinium cation, the 1-ethyl-3-methylpyridinium cation, the 1-butyl-3-methylpyridinium cation, the 1-octyl-4-methylpyridinium cation, the 1-methyl-1-propylpyrrolidinium cation, and the 1-methyl-1-propylpiperidinium cation.

Examples of cations represented by general formula (2) include imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, etc.

Specific examples of the cation represented by general formula (2) include 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl -3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation ion, 1-tetradecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazo imidazolium cations such as lithium cation, 1-hexyl-2,3-dimethylimidazolium cation; 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl- 1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl- Tetrahydropyrimidinium cations such as 1,4,5,6-tetrahydropyrimidinium cation; 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation; cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl- Dihydropyrimidinium cations such as 1,4-dihydropyrimidinium cation and 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation; and the like.

Among these, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1 -Butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3- Imidazolium cations such as methylimidazolium cation and 1-tetradecyl-3-methylimidazolium cation, more preferably 1-ethyl-3-methylimidazolium cation and 1-hexyl-3-methylimidazolium cation. be.

Examples of the cation represented by the general formula (3) include pyrazolium cations and pyrazolinium cations.

Specific examples of the cation represented by general formula (3) include 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl- Pyrazolium cations such as 2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2,3,5-trimethylpyrazolium cation; pyra such as 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1-propyl-2,3,5-trimethylpyrazolinium cation, 1-butyl-2,3,5-trimethylpyrazolinium cation, etc. Examples include zolinium cation; and the like.

Examples of the cation represented by general formula (4) include tetraalkylammonium cations, trialkylsulfonium cations, tetraalkylphosphonium cations, and some of the above alkyl groups substituted with alkenyl groups, alkoxyl groups, and even epoxy groups. Examples include things that have been done.

Specific examples of the cation represented by general formula (4) include tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, and triethylmethylammonium cation. Cation, tributylethylammonium cation, trimethylpropylammonium cation, trimethyldecylammonium cation, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium cation, glycidyltrimethylammonium cation, trimethylsulfonium cation, triethylsulfonium cation , tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethyl Examples include methylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, diallyldimethylammonium cation, and the like.

Among these, in terms of the ability to more effectively exhibit the effects of the present invention, asymmetric tetraalkylammonium cations, trialkylsulfonium cations, and tetraalkylphosphonium cations such as triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, and trimethyldecylphosphonium cation, as well as N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, and the like are preferred. N,N-dimethyl-N-ethyl-N-propyl ammonium cation, N,N-dimethyl-N-ethyl-N-butyl ammonium cation, N,N-dimethyl-N-ethyl-N-pentyl ammonium cation, N,N-dimethyl-N-ethyl-N-hexyl ammonium cation, N,N-dimethyl-N-ethyl-N-heptyl ammonium cation, N,N-dimethyl-N-ethyl-N-nonyl ammonium cation, N,N-dimethyl-N,N-dipropyl ammonium cation, N,N-diethyl-N-propyl-N-butyl ammonium cation, N,N-dimethyl-N-propyl-N-pentyl ammonium cation, N,N-dimethyl-N-propyl-N-hexyl ammonium cation ammonium cation, N,N-dimethyl-N-propyl-N-heptyl ammonium cation, N,N-dimethyl-N-butyl-N-hexyl ammonium cation, N,N-diethyl-N-butyl-N-heptyl ammonium cation, N,N-dimethyl-N-pentyl-N-hexyl ammonium cation, N,N-dimethyl-N,N-dihexyl ammonium cation, trimethylheptyl ammonium cation, N,N-diethyl-N-methyl-N-propyl ammonium cation, N,N-diethyl-N-methyl-N-pentyl ammonium cation, N,N-diethyl-N-methyl-N-heptyl ammonium cation, N,N-diethyl-N-propyl-N-pentyl ammonium cation, triethylpropyl ammonium cation Examples of ammonium cations include N,N-dipropyl-N-methyl-N-ethylammonium cation, N,N-dipropyl-N-methyl-N-pentylammonium cation, N,N-dipropyl-N-butyl-N-hexylammonium cation, N,N-dipropyl-N,N-dihexylammonium cation, N,N-dibutyl-N-methyl-N-pentylammonium cation, N,N-dibutyl-N-methyl-N-hexylammonium cation, trioctylmethylammonium cation, and N-methyl-N-ethyl-N-propyl-N-pentylammonium cation, and more preferably the trimethylpropylammonium cation.

As the fluoroorganic anion that can constitute the ionic liquid, any appropriate fluoroorganic anion can be used as long as it does not impair the effects of the present invention. Such a fluoroorganic anion may be completely fluorinated (perfluorinated) or may be partially fluorinated.

Such fluoroorganic anions include, for example, fluorinated arylsulfonates, perfluoroalkanesulfonates, bis(fluorosulfonyl)imides, bis(perfluoroalkanesulfonyl)imides, cyanoperfluoroalkanesulfonylamides, bis(cyano) Perfluoroalkanesulfonyl methide, cyano-bis-(perfluoroalkanesulfonyl)methide, tris(perfluoroalkanesulfonyl)methide, trifluoroacetate, perfluoroalkylate, tris(perfluoroalkanesulfonyl)methide, (perfluoroalkane) sulfonyl) trifluoroacetamide and the like.

Among these fluoroorganic anions, perfluoroalkylsulfonate, bis(fluorosulfonyl)imide, and bis(perfluoroalkanesulfonyl)imide are more preferred, and more specifically, for example, trifluoromethanesulfonate, pentafluoroethane These are sulfonate, heptafluoropropane sulfonate, nonafluorobutane sulfonate, bis(fluorosulfonyl)imide, and bis(trifluoromethanesulfonyl)imide.

Specific examples of the ionic liquid may be appropriately selected from the combinations of the above-mentioned cation components and the above-mentioned anion components. Specific examples of such ionic liquids include, for example, 1-hexylpyridinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylpyridinium trifluoromethanesulfonate, 1-ethyl-3-methylpyridinium pentafluoroethanesulfonate, 1-ethyl-3-methylpyridinium heptafluoropropanesulfonate, 1-ethyl-3-methylpyridinium nonafluorobutanesulfonate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, and 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonate). 1-butyl-3-methylpyridinium bis(pentafluoroethanesulfonyl)imide, 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1,1-dimethylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-ethylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide, 1-methyl-1 -butylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-pentylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-hexylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-heptylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-pentylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-hexylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-heptylpyrrolidinium bis(trifluoromethanesulfonyl)imide ) imide, 1,1-dipropylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-propyl-1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1,1-dibutylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-pentylpiperidinium bis(trifluoromethanesulfonyl)imide, 1,1-dimethylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-ethylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(fluorosulfonyl)imide, 1-methyl-1-butyl Piperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-pentylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-hexylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-heptylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-butylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-pentylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-hexylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-1-heptylpiperidinium bis(trifluoromethanesulfonyl)imide , 1,1-dipropylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-propyl-1-butylpiperidinium bis(trifluoromethanesulfonyl)imide, 1,1-dibutylpiperidinium bis(trifluoromethanesulfonyl)imide, 1,1-dimethylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-ethylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-butylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-pentylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-hexylpyrrolidinium bis(pentafluoroethanesulfonyl)imide nyl)imide, 1-methyl-1-heptylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-propylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-butylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-pentylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-hexylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-heptylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1,1-dipropylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1-propyl-1-butylpyrrolidinium bis(pentafluoroethanesulfonyl)imide, 1,1-dibutylpyrrolidinium bi bis(pentafluoroethanesulfonyl)imide, 1-propylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-pentylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1,1-dimethylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-ethylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-butylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-pentylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-hexylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-methyl-1-heptylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-propylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-butylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-pentylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-hexylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-1-heptylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1,1-dipropylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1-propyl-1-butylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1,1-dibutylpiperidinium bis(pentafluoroethanesulfonyl)imide, 1- Ethyl-3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium heptafluoropropanesulfonate, 1-ethyl-3-methylimidazolium nonafluorobutanesulfonate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-3-methylimidazolium tris(trifluoromethanesulfonyl)methide, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl- 3-Methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium perfluorobutanesulfonate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-2,3,5-trimethylpyrazolium bis(trifluoromethanesulfonyl)imide, 1-propyl-2,3,5-trimethylpyrazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-2,3,5-trimethylpyrazolium bis(trifluoromethanesulfonyl)imide ammonium bis(trifluoromethanesulfonyl)imide, 1-ethyl-2,3,5-trimethylpyrazolium bis(pentafluoroethanesulfonyl)imide, 1-propyl-2,3,5-trimethylpyrazolium bis(pentafluoroethanesulfonyl)imide, 1-butyl-2,3,5-trimethylpyrazolium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-2,3,5-trimethylpyrazolium(trifluoromethanesulfonyl)trifluoroacetamide, 1-propyl-2,3,5-trimethylpyrazolium(trifluoromethanesulfonyl)trifluoroacetamide, 1-butyl-2,3,5-trimethylpyrazolium(trifluoromethanesulfonyl)trifluoroacetamide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-heptylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-nonylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N,N-dipropylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-propyl propyl-N-butylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-propyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-propyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-propyl-N-heptylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-butyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-butyl-N-heptylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-pentyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N,N-dihexylammonium bis(trifluoromethanesulfonyl)imide, ammonium bis(trifluoromethanesulfonyl)imide, trimethylheptylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N,N-heptylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-propyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, triethylpropylammonium bis(trifluoromethanesulfonyl)imide, triethylpentylammonium bis(trifluoromethanesulfonyl)imide, triethylheptylammonium bis(tri fluoromethanesulfonyl)imide, N,N-dipropyl-N-methyl-N-ethylammonium bis(trifluoromethanesulfonyl)imide, N,N-dipropyl-N-methyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-dipropyl-N-butyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dipropyl-N,N-dihexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dibutyl-N-methyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-dibutyl-N-methyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide, N-methyl-N- Ethyl-N-propyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, 1-butylpyridinium (trifluoromethanesulfonyl)trifluoroacetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl)trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl)trifluoroacetamide, tetrahexylammonium bis(trifluoromethanesulfonyl)imide, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis(trifluoromethanesulfonyl)imide, diallyldimethylammonium bis(pentafluoroethanesulfonyl)imide, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium trifluoro Examples of such compounds include methanesulfonate, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(pentafluoroethanesulfonyl)imide, glycidyl trimethylammonium trifluoromethanesulfonate, glycidyl trimethylammonium bis(trifluoromethanesulfonyl)imide, glycidyl trimethylammonium bis(pentafluoroethanesulfonyl)imide, diallyldimethylammonium bis(trifluoromethanesulfonyl)imide, diallyldimethylbis(pentafluoroethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and lithium bis(fluorosulfonyl)imide.

Among these ionic liquids, more preferred are 1-hexylpyridinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylpyridinium trifluoromethanesulfonate, 1-ethyl-3-methylpyridinium pentafluoroethanesulfonate, 1-ethyl-3-methylpyridinium heptafluoropropanesulfonate, 1-ethyl-3-methylpyridinium nonafluorobutanesulfonate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(furansulfonyl)imide, fluorosulfonyl)imide, 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium heptafluoropropanesulfonate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-hexyl-3-methylimidazolium bis(fluorosulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and lithium bis(fluorosulfonyl)imide.

Ionic liquids may be commercially available, or may be synthesized as described below. There are no particular limitations on the method for synthesizing ionic liquids as long as the desired ionic liquid is obtained; however, generally, the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method are used, as described in the literature "Ionic Liquids - The Frontline and Future of Development" (published by CMC Publishing Co., Ltd.).

Synthesis methods for the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method are shown below using nitrogen-containing onium salts as an example, but other sulfur-containing onium salts and phosphorus-containing onium salts are also applicable. Other ionic liquids can also be obtained by the same method.

The halide method is carried out by the reactions shown in reaction formulas (1) to (3). First, a tertiary amine is reacted with an alkyl halide to obtain a halide (reaction formula (1); chlorine, bromine, or iodine are used as the halogen).

The resulting halide is reacted with an acid (HA) having the anion structure (A ⁻ ) of the desired ionic liquid or a salt (MA, where M is a cation that forms a salt with the desired anion, such as ammonium, lithium, sodium or potassium) to obtain the desired ionic liquid (R ₄ NA).

The hydroxide method is a method carried out by reactions as shown in reaction formulas (4) to (8). First, halide (R ₄ NX) is electrolyzed by ion exchange membrane method (reaction formula (4)), OH type ion exchange resin method (reaction formula (5)), or reaction with silver oxide (Ag ₂ O) (reaction formula ( 6)) to obtain hydroxide (R ₄ NOH) (chlorine, bromine, and iodine are used as halogens).

The resulting hydroxide is subjected to the reactions of formulas (7) and (8) in the same manner as in the above halogenation method to obtain the desired ionic liquid (R ₄ NA).

The acid ester method is a method carried out by reactions as shown in reaction formulas (9) to (11). First, a tertiary amine (R ₃ N) is reacted with an acid ester to obtain an acid ester (reaction formula (9). esters and esters of organic acids such as methanesulfonic acid, methylphosphonic acid, and formic acid).

The desired ionic liquid (R ₄ NA) can be obtained by using the reaction formulas (10) to (11) on the obtained acid ester product in the same manner as in the halogenation method described above. Moreover, an ionic liquid can also be obtained directly by using methyl trifluoromethanesulfonate, methyl trifluoroacetate, or the like as an acid ester.

The neutralization method is a method performed by a reaction as shown in reaction formula (12). Reacting a tertiary amine with an organic acid such as CF ₃ COOH, CF ₃ SO ₃ H, (CF ₃ SO ₂ ) ₂ NH, (CF ₃ SO ₂ ) ₃ CH, (C ₂ F ₅ SO ₂ ) ₂ NH, etc. This can be obtained by

In the above reaction formulas (1) to (12), R represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a heteroatom.

The content of the ionic liquid in the adhesive composition may be any appropriate content within the range that does not impair the effects of the present invention. In terms of the effect of the present invention being more pronounced, the content is preferably 0.001 to 50 parts by weight, more preferably 0.01 to 40 parts by weight, even more preferably 0.01 to 30 parts by weight, particularly preferably 0.01 to 20 parts by weight, and most preferably 0.01 to 10 parts by weight, relative to the solid content (100 parts by weight) of the (meth)acrylic copolymer (A). By adjusting the amount of the ionic liquid to be blended within the above range, an adhesive composition with extremely excellent antistatic properties can be provided. If the amount of the ionic liquid is less than 0.01 parts by weight, sufficient antistatic properties may not be obtained. If the amount of the ionic liquid is more than 50 parts by weight, contamination of the adherend may increase.

<Modified silicone oil>
The pressure-sensitive adhesive composition may contain modified silicone oil. When the pressure-sensitive adhesive composition contains modified silicone oil, the antistatic effect can be more effectively exhibited. In particular, when the pressure-sensitive adhesive composition contains modified silicone oil and an ionic liquid, the antistatic effect can be more effectively exhibited.

The content of the modified silicone oil in the adhesive composition may be any suitable content within a range that does not impair the effects of the present invention. Such a content is preferably 0.001 parts by weight based on the solid content (100 parts by weight) of the (meth)acrylic copolymer (A), in order to better express the effects of the present invention. -50 parts by weight, more preferably 0.005 parts by weight - 40 parts by weight, still more preferably 0.007 parts by weight - 30 parts by weight, particularly preferably 0.008 parts by weight - 20 parts by weight. The amount is most preferably 0.01 parts by weight to 10 parts by weight. By adjusting the content of the modified silicone oil within the above range, the antistatic properties can be more effectively exhibited.

As the modified silicone oil, any suitable modified silicone oil may be employed as long as the effects of the present invention are not impaired. Examples of such modified silicone oil include modified silicone oil available from Shin-Etsu Chemical Co., Ltd.

The modified silicone oil is preferably a polyether modified silicone oil. By employing polyether-modified silicone oil, antistatic properties can be more effectively exhibited.

Examples of the polyether-modified silicone oil include side chain type polyether-modified silicone oil, double-end type polyether-modified silicone oil, and the like. Among these, polyether-modified silicone oil having both ends is preferable because it can sufficiently exhibit the antistatic property effect even more effectively.

<Other components that may be included in the adhesive composition>
The pressure-sensitive adhesive composition may contain any other appropriate components within a range that does not impair the effects of the present invention. Examples of such other components include other polymer components, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), and anti-aging agents. , inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foils, ultraviolet absorbers, antioxidants, light stabilizers, chain transfer agents, plasticizers, softeners, surfactants , antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc.

<Base layer>
The base layer may be a single layer or may be two or more layers. The base layer may be a stretched layer.

The thickness of the substrate layer is preferably 1 μm to 500 μm, more preferably 5 μm to 400 μm, even more preferably 10 μm to 300 μm, and particularly preferably 15 μm to 200 μm.

For the side of the base layer to which no adhesive layer is attached, for example, fatty acid amide, polyethyleneimine, long-chain alkyl additives are added to the base layer for the purpose of forming a wound body that is easy to unwind. A coating layer made of any appropriate release agent such as a silicone-based, long-chain alkyl-based, or fluorine-based release agent may be provided.

As the material for the substrate layer, any appropriate material may be adopted depending on the application. Examples include plastic, paper, metal film, nonwoven fabric, etc. Plastic is preferable. That is, the substrate layer is preferably a plastic film. The substrate layer may be made of one type of material, or may be made of two or more types of materials. For example, it may be made of two or more types of plastic.

Examples of the plastics include polyester resins, polyamide resins, polyolefin resins, and the like. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of the polyolefin resin include homopolymers of olefin monomers and copolymers of olefin monomers. Specific examples of polyolefin resins include, for example, homopolypropylene; block, random, and graft type propylene copolymers containing ethylene as a copolymerization component; reactor TPO; low density, high density, and linear Ethylene-based polymers with low density and ultra-low density; ethylene/propylene copolymer, ethylene/vinyl acetate copolymer, ethylene/methyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/acrylic acid Examples include ethylene copolymers such as butyl copolymers, ethylene/methacrylic acid copolymers, and ethylene/methyl methacrylate copolymers.

The substrate layer may contain any suitable additive as necessary. Examples of additives that may be contained in the substrate layer include antioxidants, UV absorbers, light stabilizers, antistatic agents, fillers, and pigments. The type, number, and amount of additives that may be contained in the substrate layer may be appropriately set depending on the purpose. In particular, when the material of the substrate layer is plastic, it is preferable to contain some of the above additives for the purpose of preventing deterioration, etc. From the viewpoint of improving weather resistance, etc., particularly preferred additives include antioxidants, UV absorbers, light stabilizers, and fillers.

Any suitable antioxidant may be used as the antioxidant. Examples of such antioxidants include phenol-based antioxidants, phosphorus-based processing heat stabilizers, lactone-based processing heat stabilizers, sulfur-based heat stabilizers, and phenol-phosphorus-based antioxidants. The content of the antioxidant is preferably 1% by weight or less, more preferably 0.5% by weight or less, and even more preferably 0.01% by weight to 0.2% by weight, based on the base resin of the substrate layer (when the substrate layer is a blend, the blend is the base resin).

Any suitable ultraviolet absorber can be employed as the ultraviolet absorber. Examples of such UV absorbers include benzotriazole UV absorbers, triazine UV absorbers, and benzophenone UV absorbers. The content of the ultraviolet absorber is preferably 2% by weight or less, based on the base resin forming the base layer (if the base layer is a blend, the blend is the base resin), and more It is preferably 1% by weight or less, more preferably 0.01% to 0.5% by weight.

Any suitable light stabilizer may be employed as the light stabilizer. Examples of such light stabilizers include hindered amine light stabilizers and benzoate light stabilizers. The content of the light stabilizer is preferably 2% by weight or less, based on the base resin forming the base layer (if the base layer is a blend, the blend is the base resin), and more preferably It is preferably 1% by weight or less, more preferably 0.01% to 0.5% by weight.

Any suitable filler can be used as the filler. Examples of such fillers include inorganic fillers. Specific examples of the inorganic filler include carbon black, titanium oxide, zinc oxide, and the like. The content of the filler is preferably 20% by weight or less, more preferably 20% by weight or less, based on the base resin forming the base layer (if the base layer is a blend, the blend is the base resin). is 10% by weight or less, more preferably 0.01% by weight to 10% by weight.

Furthermore, as additives, preferred for the purpose of imparting antistatic properties are inorganic, low molecular weight and high molecular weight antistatic agents such as surfactants, inorganic salts, polyhydric alcohols, metal compounds and carbon. In particular, high molecular weight antistatic agents and carbon are preferred from the viewpoints of preventing contamination and maintaining adhesion.

<<Applications>>
The surface protection film of the present invention has high adhesive strength and easy peelability, and can suppress the generation of bubbles even when it is subjected to high temperature and high pressure treatment in an autoclave or the like after being attached to an adherend and then returned to room temperature and normal pressure. Therefore, it can be suitably used for protecting the surface of an adherend that requires the above-mentioned properties for the surface protection film.

Such an adherend preferably includes an adherend whose surface has a water contact angle of 60 degrees or more. The water contact angle of the surface of such an adherend is preferably 65 degrees or more, more preferably 70 degrees or more, still more preferably 75 degrees or more, and particularly preferably 80 degrees or more. For adherends whose surface has a water contact angle within the above range, after pasting a conventional surface protection film, high temperature and high pressure treatment in an autoclave etc. is performed, and then the temperature is returned to normal temperature and pressure to prevent the formation of bubbles. Easy to occur. When the surface protection film of the present invention is used, even if it is applied to an adherend whose surface has a water contact angle within the above range, subjected to high temperature and high pressure treatment in an autoclave, etc., and then returned to normal temperature and pressure, The generation of bubbles can be suppressed.

Examples of such substrates include unsaponified TAC (triacetyl cellulose) film, and barrier films that can be used in devices such as organic electroluminescence displays and OLEDs.

The present invention will be explained in detail below with reference to examples, but the present invention is not limited to these examples in any way. The test and evaluation methods used in the examples are as follows. Note that "parts" means "parts by weight" unless otherwise specified, and "%" means "% by weight" unless otherwise specified.

<Measurement of weight average molecular weight>
The weight average molecular weight was measured by gel permeation chromatography (GPC). Specifically, the GPC measurement device was a product name "HLC-8120GPC" (manufactured by Tosoh Corporation) under the following conditions, and the weight average molecular weight was calculated based on the standard polystyrene equivalent value.
(Molecular weight measurement conditions)
Sample concentration: 0.2% by weight (tetrahydrofuran solution)
Sample injection volume: 10 μL
Column: Product name "TSKguard column Super HZ-H (1 column) + TSKgel Super HZM-H (2 columns)" (manufactured by Tosoh Corporation)
Reference column: Product name "TSKgel Super H-RC (1 piece)" (manufactured by Tosoh Corporation)
Eluent: tetrahydrofuran (THF)
Flow rate: 0.6 mL / min
Detector: differential refractometer (RI)
Column temperature (measurement temperature): 40°C

<Pulse NMR measurement of adhesive layer>
Pulse NMR measurements were performed using the CPMG method. Specifically, the measurement was carried out under the following conditions using a pulse NMR measuring device with the trade name "TD-NMR the minispec mq20" (manufactured by Brukar).
(Relaxation time measurement conditions)
・Measurement method: CPMG method ・90° pulse width: 2.1 μs
・Repetition time: 1 second ・Number of integration: 64 times ・Measurement temperature: 30℃, 60℃
・Analysis method: Nonlinear least squares method

<Measurement of shear adhesive strength>
After cutting the surface protection film into a size of 10 mm in width and 100 mm in length and peeling off the separator, cut the unkenned film obtained in Production Example 5 described below so that the adhesive (adhesion) area of the exposed adhesive layer is 1 cm ^2. It was pasted on a chemical TAC polarizing plate (width 70 mm, length 100 mm, water contact angle = 69.9 degrees), left to stand for 30 minutes in an environment of 23°C x 50% RH, and then peeled at a peeling rate of 0.06 mm/min. The film was peeled in the shear direction, and the maximum load (N/cm ² ) at that time was taken as the shear adhesive strength.

<Measurement of high-speed peel force>
The surface protective film was cut to a size of 25 mm wide and 100 mm long, and the separator was peeled off. The surface of the unsaponified TAC polarizing plate (width 70 mm, length 100 mm, water contact angle = 69.9 degrees) obtained in Production Example 5 described later was pressed with a hand roller, and then laminated under pressure conditions of 0.25 MPa and 0.3 m/min to prepare an evaluation sample. Next, the separator on the polarizing plate side of the evaluation sample was peeled off, and the sample was pressed with a hand roller onto a slide glass having a thickness of 1.3 mm, a width of 65 mm, and a length of 165 mm. After leaving the sample in an environment of 23 ° C. x 50% RH for 30 minutes, the adhesive strength was measured when one end of the surface protective film was peeled off at a tensile speed of 30 m/min and a peel angle of 180 ° using a universal tensile tester. The measurement was performed in an environment of 23 ° C. x 50% RH.

<Measurement of the number of bubbles generated after high temperature and high pressure treatment>
The surface protection film was cut into a size of 65 mm in width and 90 mm in length, and after peeling off the separator, it was pressed onto the surface of an adherend (70 mm in width and 100 mm in length) with a hand roller, and then heated at 0.25 MPa and 0.2 mm. It was laminated under a pressure bonding condition of 3 m/min, and the four sides were cut from the surface protection film side using a cutting machine so as to have a width of 50 mm and a length of 80 mm, and this was used as an evaluation sample. Peel off the separator on the polarizing plate side, press it onto a slide glass with a thickness of 1.3 mm, width of 65 mm, and length of 165 mm using a hand roller, leave it in an environment of 23 ° C. After performing autoclave treatment for 40 minutes in an environment of
As the adherend, the following one prepared in the manufacturing example described below was used.
Adherent (A): Unsaponified TAC polarizing plate with adhesive layer (water contact angle = 69.9 degrees)
Adherent (B): Anti-glare treated polarizing plate with adhesive layer (water contact angle = 88.4 degrees)
Adherent (C): Saponified TAC polarizing plate with adhesive layer (water contact angle = 53.1 degrees)

<Measurement of Water Contact Angle>
Using DM-501 manufactured by Kyowa Interface Science Co., Ltd., 2 μL of ion-exchanged water was dropped with a syringe, and the waiting time from the drop to the measurement was set to 1000 ms. The water contact angle was measured at five points in the width direction at any multiple points on the adherend, and the average value was taken as the water contact angle of the adherend.

<Measurement of swelling degree>
The swelling degree was measured by the following method: About 0.1 g of the polymer after the crosslinking reaction was sampled, wrapped in a porous tetrafluoroethylene sheet (trade name "NTF1122", manufactured by Nitto Denko Corporation) having an average pore size of 0.2 μm, and then tied with string, and the weight at that time was measured and used as the weight before immersion (total weight of the polymer, tetrafluoroethylene sheet, and string). Meanwhile, the total weight of the tetrafluoroethylene sheet and string was also measured and used as the wrapping weight. Next, the above polymer was wrapped in a tetrafluoroethylene sheet and tied with string (referred to as a "sample"), which was placed in a 50 ml container filled with ethyl acetate and left to stand at 23°C for 7 days. Thereafter, the sample after immersion in ethyl acetate was taken out of the container, the ethyl acetate adhering to the sample was thoroughly wiped off with a rag, and the weight was measured, which was recorded as the post-immersion weight. The sample was then transferred to an aluminum cup and dried in a dryer at 130°C for 2 hours. After removing the ethyl acetate, the weight was measured and recorded as the post-drying weight. The swelling degree was calculated from the following formula.
Swelling degree (%) = (a-b) / (c-b) × 100 (1)
In the formula (1), a is the weight after immersion, b is the package weight, and c is the weight after drying.
Furthermore, when collecting the crosslinked polymer, it may be collected from the pressure-sensitive adhesive layer surface of the surface protection film, or it may be collected from a silicone separator or the like on which the same pressure-sensitive adhesive layer as that provided on the surface protection film has been separately applied and dried.

[Production Example 1]: Production of acrylic copolymer (1) Into a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 100 parts by weight of 2-ethylhexyl acrylate (2EHA) (manufactured by Nippon Shokubai Co., Ltd.), 10 parts by weight of 4-hydroxybutyl acrylate (4HBA) (manufactured by Nippon Kasei Co., Ltd.), 0.02 parts by weight of acrylic acid (AA) (manufactured by Nippon Shokubai Co., Ltd.), 0.02 parts by weight of 2,2'-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 180 parts by weight of ethyl acetate were charged, and nitrogen gas was introduced while gently stirring. The liquid temperature in the flask was kept at around 65°C, and a polymerization reaction was carried out for 6 hours to prepare a solution of acrylic copolymer (1) having a weight average molecular weight of 540,000 (solid content: 35% by weight).

[Production Example 2]: Production of acrylic copolymer (2) 2-ethylhexyl acrylate (2EHA) (manufactured by Nippon Shokubai Co., Ltd.) was placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a condenser. ): 100 parts by weight, 2-hydroxyethyl acrylate (HEA) (manufactured by Toagosei Co., Ltd.): 4 parts by weight, 2,2'-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator: 0 02 parts by weight of ethyl acetate and 180 parts by weight of ethyl acetate were introduced, nitrogen gas was introduced while stirring gently, and the polymerization reaction was carried out for 6 hours while maintaining the liquid temperature in the flask at around 65°C. A solution (solid content: 35% by weight) of acrylic copolymer (2) was prepared.

[Production Example 3]: Production of methacrylic copolymer (3) Into a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 100 parts by weight of toluene, 60 parts by weight of dicyclopentadienyl methacrylate (DCPMA) (product name: FA-513M, manufactured by Hitachi Chemical Co., Ltd.), 40 parts by weight of methyl methacrylate (MMA) (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 3.5 parts by weight of methyl thioglycolate as a chain transfer agent were added. Then, after stirring for 1 hour under a nitrogen atmosphere at 70 ° C., 0.2 parts by weight of 2,2'-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) was added as a polymerization initiator, and the mixture was reacted at 70 ° C. for 2 hours, followed by reacting at 80 ° C. for 4 hours, and then reacting at 90 ° C. for 1 hour to prepare a solution (solid content: 60% by weight) of methacrylic copolymer (3) with a weight average molecular weight of 4400 and Tg = 144 ° C. (calculated from Fox's formula).

[Production Example 4]: Production of acrylic adhesive composition (P1) for forming adhesive for polarizing plate (production of solution of acrylic polymer (A1))
Butyl acrylate (BA): 94.9 parts by weight, acrylic acid (AA): 5 parts by weight, hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas introduction tube, and condenser. : A monomer mixture containing 0.1 part by weight was charged. Furthermore, 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added together with ethyl acetate to 100 parts by weight of the monomer mixture, and nitrogen gas was added while stirring gently. After introducing the flask and purging it with nitrogen, the temperature of the liquid in the flask was maintained at around 55° C. and a polymerization reaction was carried out for 7 hours. Thereafter, ethyl acetate was added to the obtained reaction solution to prepare a solution of an acrylic polymer (A1) having a weight average molecular weight of 2 million, which was adjusted to a solid content concentration of 20%.
(Acrylic adhesive composition (P1))
Isocyanate crosslinking agent (trade name: Coronate L, Rimethylolpropane/tolylene diisocyanate, manufactured by Nippon Polyurethane Kogyo Co., Ltd.): 0.6 with respect to 100 parts by weight of the solid content of the obtained acrylic polymer (A1) solution. and 0.1 part by weight of a silane coupling agent (trade name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd.) to prepare an acrylic adhesive composition (P1).

[Production Example 5]: Production of adherend (A) (preparation of polarizer)
A polyvinyl alcohol film with a thickness of 75 μm (manufactured by Kuraray Co., Ltd.: VF-PS7500, width 1000 mm) was stretched to a stretching ratio of 2.5 times while immersed in pure water at 30°C for 60 seconds. Dyeing for 45 seconds in an iodine aqueous solution (weight ratio: pure water/iodine (I)/potassium iodide (KI) = 100/0.01/1), and a stretching ratio of 5.8 in a 4% by weight boric acid aqueous solution. The film was stretched to double its size, immersed in pure water for 10 seconds, and then dried at 60° C. for 5 minutes while maintaining the tension of the film to obtain a polarizer. The thickness of this polarizer was 25 μm, and the moisture content was 15% by weight.
(Production of transparent protective film with adhesive layer)
100 parts by weight of PVA resin (Gohsenol, manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) and 35 parts by weight of crosslinking agent (Watersol, manufactured by Dainippon Ink Chemical Industry Co., Ltd.) were dissolved in 3760 parts by weight of pure water. Adjust the adhesive. This adhesive was applied using a slot die to one side of a 60 μm thick triacetyl cellulose (TAC) film (manufactured by Fujifilm: TD-60UL), and dried at 85°C for 1 minute to form a 0.1 μm thick adhesive. A TAC film with an adhesive layer and an adhesive layer was obtained.
(Preparation of polarizing plate (A))
A polarizing plate (A) was produced by the method shown in FIG. The above polarizer was used as the polarizer, and the above unsaponified TAC film with an adhesive layer was used as the first transparent protective film B1. For the second transparent protective film B2, an acrylic film with an adhesive layer was used. It was prepared in the same manner as the TAC film. As shown in FIG. 2, the TAC film with an adhesive layer (first transparent protective film B1) is placed on the first roll R1, and the acrylic film with an adhesive layer (second transparent protective film B2) is placed on the second roll. It was transported from the R2 side. Iron rolls with a diameter of 200 mm were used as the first roll R1 and the second roll R2. The transport speed of each film was 20 m/min. Note that the obtained polarizing plate (A) was dried at 80° C. for 2 minutes after bonding.
(Manufacture of adherend (A))
The acrylic adhesive composition (P1) obtained in Production Example 4 was uniformly coated with a fountain coater on the surface of a 38 μm thick polyethylene terephthalate film (separator) treated with a silicone release agent, and heated at 155°C. A pressure-sensitive adhesive layer having a thickness of 20 μm was prepared by drying for 2 minutes in an air circulating constant temperature oven. Next, the second transparent protective film surface of the above polarizing plate (A) is corona-treated, and a separator on which an adhesive layer is formed is bonded to the corona-treated surface, and the adhesive layer as the adherend (A) is A layered unsaponified TAC polarizing plate was produced. The produced unsaponified TAC polarizing plate with an adhesive layer had a water contact angle of 69.9 degrees.

[Production Example 6]: Production of Adherend (B) (Preparation of Aqueous Adhesive Solution)
100 parts by weight of an acetoacetyl group-containing polyvinyl alcohol resin (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, degree of acetoacetyl group modification: 5 mol%) and 50 parts by weight of methylol melamine were dissolved in pure water at 30°C to prepare an aqueous solution adjusted to a solids concentration of 3.7% by weight. To 100 parts by weight of this aqueous solution, 18 parts by weight of an aqueous alumina colloid solution (average particle size: 15 nm, solids concentration: 10% by weight, positive charge) was added to prepare an aqueous adhesive solution. The viscosity of the aqueous adhesive solution was 9.6 mPa·s, and the pH was in the range of 4 to 4.5.
(Preparation of Surface-Treated Polarizing Plate)
To an ultraviolet-curable resin composition consisting of 100 parts by weight of an ultraviolet-curable urethane acrylate monomer and 3 parts by weight of a benzophenone-based photopolymerization initiator, 15 parts by weight of silica particles having an average particle size of 0.5 μm and 10 parts by weight of silica particles having an average particle size of 1.4 μm were added to obtain a resin mixture. A viscosity adjusting solvent was further added to the obtained resin mixture to make the solid content concentration 50% by weight, and then mixed with a high-speed stirrer. The obtained mixture was applied to the first transparent protective film B1 (TAC film) side of the polarizing plate (A) produced in Production Example 5 with a bar coater, and after the solvent was evaporated, it was irradiated with ultraviolet light and cured to obtain an anti-glare treated polarizing plate (B) consisting of an ultraviolet-cured resin film having a thickness of 7 μm with a surface fine uneven structure.
(Production of Adherend (B))
Except for using the anti-glare treated polarizing plate (B) instead of the polarizing plate (A), the same procedure as in Production Example 5 was carried out to obtain an anti-glare treated polarizing plate with a pressure-sensitive adhesive layer as the adherend (B). The water contact angle of the produced anti-glare treated polarizing plate with a pressure-sensitive adhesive layer was 88.4 degrees.

[Production Example 7]: Production of adherend (C) A 60 μm thick polyvinyl alcohol film (average degree of polymerization 2400, manufactured by Kuraray Co., Ltd. VF-PE-A #6000) was used as the original film. The polyvinyl alcohol film was subjected to the following steps in the following order.
(swelling process)
The swelling step was carried out by two swelling baths of the embodiment shown in FIG. Pure water was used as the treatment liquid in each swelling bath. As the guide roll 13 installed in the first-stage swelling bath in FIG. 3, an expander roll with a radius of curvature of 2000 mm was used. The expander roll was placed at a position of 80% of the length of the polyvinyl alcohol film immersed in the treatment liquid (dotted line length between p1 and p2 in FIG. 3). Note that flat rolls were used as other guide rolls.
<1st stage>
The polyvinyl alcohol film was transferred to a one-stage swelling bath, immersed in pure water adjusted to 40° for 60 seconds, and uniaxially stretched to a stretching ratio of 1.80 times while swelling.
<2nd stage>
Subsequently, the polyvinyl alcohol film subjected to the first-stage swelling process is transported to a second-stage swelling bath, and immersed in pure water adjusted to 30°C for 60 seconds, and while being swollen, a stretching ratio of 1. 10 (total stretching ratio 1.98 times).
(dying process)
As the treatment liquid for the dyeing bath, an iodine dyeing solution containing iodine:potassium iodide (weight ratio=0.5:8) with a concentration of 0.3% by weight was used. The polyvinyl alcohol film subjected to the swelling treatment was transported to a dyeing bath, and immersed in the iodine dyeing solution adjusted to 30° C. for 60 seconds while being uniaxially stretched and dyed at a total stretching ratio of 3 times the original length. .
(Crosslinking process)
As the treatment liquid for the crosslinking bath, an aqueous boric acid solution containing 3% by weight of boric acid and 3% by weight of potassium iodide was used. The treated polyvinyl alcohol film was transferred to a crosslinking bath, and uniaxially stretched to a total extension ratio of 4 times the original length while being immersed in the boric acid aqueous solution adjusted to 30° C. for 19 seconds.
(Stretching process)
As the treatment liquid for the stretching bath, an aqueous boric acid solution containing 4% by weight of boric acid and 5% by weight of potassium iodide was used. The above-treated polyvinyl alcohol film was transported to a stretching bath, and uniaxially stretched to a total stretching ratio of 6 times the original length while being immersed in a boric acid aqueous solution adjusted to 60° C. for 13 seconds.
(Washing process)
As the treatment liquid for the cleaning bath, an aqueous solution containing 3% by weight of potassium iodide was used. The treated polyvinyl alcohol film was transferred to a cleaning bath and immersed in the aqueous solution adjusted to 30° C. for 10 seconds.
(drying process)
Next, the treated polyvinyl alcohol film was dried in an oven at 60° C. for 4 minutes to obtain a polarizer.
(Manufacture of adherend (C))
A saponified triacetyl cellulose film with a thickness of 80 μm was laminated on both sides of the polarizer obtained above via an adhesive consisting of a 5% by weight fully saponified polyvinyl alcohol aqueous solution, and then rolled After being brought into close contact with each other, it was dried at 70° C. for 4 minutes. Thereafter, the same procedure as in Production Example 5 was carried out except that the saponified TAC polarizing plate (C) was used instead of the polarizing plate (A), and the saponified TAC polarizing plate with the adhesive layer was used as the adherend (C). Obtained. The produced saponified TAC polarizing plate with an adhesive layer had a water contact angle of 53.1 degrees.

Example 1: Production of adhesive composition (1) and surface protective film (1) The solution of the acrylic copolymer (1) obtained in Production Example 1 was diluted with ethyl acetate to 10% with 2 parts by weight (0.2 parts by weight in terms of solid content) of a solution of an oxyalkylene chain-containing organosiloxane (KF-353, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silicone component, 0.15 parts by weight of lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2 _{) 2} :LiTFSI, manufactured by Tokyo Chemical Industry Co., Ltd.) as an alkali metal salt (ionic compound) as an antistatic agent, 3.4 parts by weight of an isocyanate-based crosslinking agent (product name " _Coronate HX", manufactured by Tosoh Corporation), 0.006 parts of Nursem ferric as a crosslinking catalyst, 0.01 parts of Envirizer OL-1 (manufactured by Tokyo Fine Chemical Co., Ltd.), and the methacrylic copolymer ( 3) obtained in Production Example 3 were added to the solution, based on 100 parts by weight of the solid content. 0.2 parts by weight of a solution of acrylic copolymer (1) in terms of solid content was added thereto, and further, 1 part by weight of a polyoxyalkylene glycol compound (SANNICS GP-250, manufactured by Sanyo Chemical Industries, Ltd.) was added thereto for 100 parts by weight of the solid content of the solution of acrylic copolymer (1) obtained in Production Example 1. The mixture was diluted with toluene to a total solid content of 20% by weight, and stirred with a disper to obtain a pressure-sensitive adhesive composition (1).
The obtained adhesive composition (1) was applied to a polyester resin substrate "Lumirror S10" (thickness 38 μm, manufactured by Toray Industries, Inc.) using a fountain roll so that the thickness after drying would be 10 μm, and the coating was cured and dried under conditions of a drying temperature of 130° C. and a drying time of 20 seconds. In this manner, an adhesive layer was produced on the substrate. Next, the silicone-treated surface of a 19 μm thick polyester resin substrate, one side of which had been silicone-treated, was bonded to the surface of the adhesive layer to obtain a surface protection film (1).
The results are shown in Table 1.

[Example 2]: Production of adhesive composition (2) and surface protective film (2) The same procedure as in Example 1 was carried out, except that the amount of Coronate HX was changed to 8.1 parts by weight in terms of solid content, and the amount of GP250 was changed to 3 parts by weight, to obtain an adhesive composition (2) and a surface protective film (2).
The results are shown in Table 1.

[Example 3]: Production of adhesive composition (3) and surface protection film (3) The same procedure as in Example 1 was carried out, except that the amount of Coronate HX was changed to 12.8 parts by weight in terms of solid content, and the amount of GP250 was changed to 5 parts by weight, to obtain an adhesive composition (3) and a surface protection film (3).
The results are shown in Table 1.

[Example 4]: Production of adhesive composition (4) and surface protection film (4) The same procedure as in Example 1 was carried out, except that the amount of Coronate HX was changed to 1.7 parts by weight in terms of solid content, and GP250 was changed to 1 part by weight of GP600 (manufactured by Sanyo Chemical Industries, Ltd., polyoxypropylene glyceryl ether, Mn = 600), to obtain an adhesive composition (4) and a surface protection film (4).
The results are shown in Table 1.

[Example 5]: Production of adhesive composition (5) and surface protection film (5) The amount of Coronate HX was changed to 1.6 parts by weight in terms of solid content, and GP250 was changed to GP1000 (manufactured by Sanyo Chemical Co., Ltd., Polyoxypropylene glyceryl ether (Mn=1000): The same procedure as in Example 1 was performed except that the amount was changed to 1 part by weight, to obtain an adhesive composition (5) and a surface protection film (5).
The results are shown in Table 1.

[Example 6]: Production of adhesive composition (6) and surface protection film (6) The amount of Coronate HX was changed to 3.6 parts by weight in terms of solid content, and GP250 was replaced with Adeka Polyether EDP-300 (stock). Manufactured by ADEKA company, N,N,N',N',-tetrakis(2-hydroxypropyl)ethylenediamine, Mn=300): 1 part by weight, and Nathem zinc was used instead of Enbilizer OL-1 as a crosslinking catalyst. (Manufactured by Nihon Kagaku Sangyo Co., Ltd., zinc acetylacetone monohydrate) The same procedure as in Example 1 was carried out except that the amount was changed to 0.01 part by weight, and the adhesive composition (6) and surface protection film (6) were Obtained.
The results are shown in Table 1.

[Example 7]: Production of adhesive composition (7) and surface protective film (7) As the polyol (A), Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three OH groups, 85 parts by weight, Sannix GP-3000 (manufactured by Sanyo Chemical Industries Co., Ltd., Mn = 3000), which is a polyol having three OH groups, 13 parts by weight, Sannix GP-1000 (manufactured by Sanyo Chemical Industries Co., Ltd., Mn = 1000), which is a polyol having three OH groups, 2 parts by weight were used, and as the polyfunctional isocyanate compound (B), Coronate HX (Nippon Polyurethane Industry Co., Ltd.), which is a polyfunctional alicyclic isocyanate compound, was used. 0.04 parts by weight of a catalyst (manufactured by Nippon Chemical Industries Co., Ltd., trade name: Narsem ferric): 210 parts by weight of ethyl acetate as a dilution solvent was mixed and stirred with a disperser to obtain an adhesive composition (7).
The obtained adhesive composition (7) was applied to a polyester resin substrate "Lumirror S10" (thickness 38 μm, Toray Industries, Inc.) using a fountain roll so that the thickness after drying would be 10 μm, and the substrate was cured and dried under conditions of a drying temperature of 130° C. and a drying time of 2 minutes. In this manner, an adhesive layer was produced on the substrate. Next, the silicone-treated surface of a 19 μm thick polyester resin substrate, one side of which had been silicone-treated, was bonded to the surface of the adhesive layer to obtain a surface protection film (7). The results are shown in Table 1.

[Comparative Example 1]: Production of adhesive composition (C1) and surface protection film (C1) The solution of the acrylic copolymer (1) obtained in Production Example 1 was diluted to 20% by weight with ethyl acetate, A solution in which 500 parts by weight of this solution (solid content: 100 parts by weight) was diluted with ethyl acetate to 10% by weight of an organosiloxane having an oxyalkylene chain (KF-353, manufactured by Shin-Etsu Chemical Co., Ltd.), which is a silicone component: 2 weight parts (0.2 parts by weight in terms of solid content), lithium bis(trifluoromethanesulfonyl)imide (LiN(CF ₃ SO ₂ ) ₂ :LiTFSI, Tokyo Chemical Industry Co., Ltd.) as an alkali metal salt (ionic compound) as an antistatic agent. ): 0.15 parts by weight, 3.5 parts by weight of an isocyanate-based crosslinking agent (trade name "Coronate HX", manufactured by Tosoh Corporation), Enbilizer OL-1 (manufactured by Tokyo Fine Chemical Co., Ltd.) as a crosslinking catalyst. 0.02 parts by weight, 0.5 parts by weight of the solution of methacrylic copolymer (2) obtained in Production Example 2 was added as solid content, and diluted with toluene so that the total solid content was 20% by weight. The mixture was stirred with a disper to obtain an adhesive composition (C1).
The obtained adhesive composition (C1) was applied to a base material "Lumirror S10" (thickness 38 μm, manufactured by Toray Industries, Inc.) made of polyester resin using a fountain roll so that the thickness after drying was 15 μm, and the drying temperature was 130 μm. Cure and drying for 20 seconds. In this way, an adhesive layer was produced on the base material. Next, the silicone-treated surface of a base material made of a polyester resin having a thickness of 19 μm and having undergone silicone treatment on one side was laminated to the surface of the adhesive layer to obtain a surface protection film (C1).
The results are shown in Table 1.

Comparative Example 2: Preparation of adhesive composition (C2) and surface protective film (C2) The solution of the acrylic copolymer (2) obtained in Preparation Example 2 was diluted to 20% by weight with ethyl acetate, and 100 parts by weight of this solution was diluted with ethyl acetate to 10% by weight with organosiloxane (trade name: KF6004, manufactured by Shin-Etsu Chemical Co., Ltd.) having a polyoxyalkylene chain in the main chain: 0.8 parts by weight, ethyl acetate to 10% by weight with lithium bis(trifluoromethanesulfonyl)imide (manufactured by Tokyo Chemical Industry Co., Ltd.): 0.2 parts by weight, isocyanate-based crosslinking agent (trade name: Coronate L, manufactured by Tosoh Corporation, 75% by weight): 0.8 parts by weight, and Envirizer OL-1 (manufactured by Tokyo Fine Chemical Co., Ltd.): 0.02 parts by weight as a crosslinking catalyst, diluted with toluene so that the total solid content was 20% by weight, and stirred with a disperser to obtain an adhesive composition (C2).
The obtained adhesive composition (C2) was applied to a polyester resin substrate "Lumirror S10" (thickness 38 μm, manufactured by Toray Industries, Inc.) using a fountain roll so that the thickness after drying would be 10 μm, and the coating was cured and dried under conditions of a drying temperature of 130° C. and a drying time of 20 seconds. In this manner, an adhesive layer was produced on the substrate. Next, the silicone-treated surface of a 19 μm thick polyester resin substrate, one side of which had been silicone-treated, was bonded to the surface of the adhesive layer to obtain a surface protection film (C2).
The results are shown in Table 1.

The surface protection film of the present invention can be used for any suitable application. Preferably, the surface protection film of the present invention is used in the fields of optical components and electronic components.

1 Base material layer 2 Adhesive layer 10 Surface protection film A Polarizer B1 First transparent protective film B2 Second transparent protective film R1 First roll R2 Second roll M Angle changing means

Claims (15)

A surface protection film comprising a pressure-sensitive adhesive layer and a base layer,
the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition containing a (meth)acrylic copolymer (A), a polyfunctional alcohol (C) and a crosslinking agent (D);
when a free induction decay signal obtained by pulse NMR measurement of the pressure-sensitive adhesive layer is separated into two components by a nonlinear least squares method, the component having a short relaxation time is a hard component (S) and the component having a long relaxation time is a soft component (L), the ratio T2(L)/T2(L) of the spin-spin relaxation time T2(L) of the proton of the soft component (L) measured at ₃₀ °C to the spin-spin relaxation time T2(L) of the proton of the soft component (L) measured at ₆₀ ° _C is _2.15 to 3.05,
The shear adhesive strength is 10 N/ ^cm2 or more,
The high-speed peel strength is 0.8 N/25 mm or less.
Surface protection film. The surface protection film according to claim 1, wherein the adhesive layer has a thickness of 1 μm to 500 μm. The surface protection film according to claim 1 or 2, wherein the base layer has a thickness of 1 μm to 500 μm. The (meth)acrylic copolymer (A) has (a1 component) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms, (a2 component) an OH group ( The surface protection film according to any one of claims 1 to 3 , which is formed by polymerization from a composition (a) containing a meth)acrylic acid ester. The surface protection film according to claim 4 , wherein the composition (a) contains (meth)acrylic acid. The surface protection film according to any one of claims 1 to 5 , wherein the polyfunctional alcohol (C) has 3 to 6 functional groups. The surface protection film according to any one of claims 1 to 6 , wherein the polyfunctional alcohol (C) has a number average molecular weight of 50 to 10,000. The adhesive composition is a (meth)acrylic acid formed by polymerization from a composition (b) containing a (meth)acrylic acid alkyl ester in which the alkyl group of the alkyl ester portion (b1 component) is an alicyclic hydrocarbon group. The surface protection film according to any one of claims 1 to 7 , comprising the copolymer (B). 9. The surface protective film according to claim 8 , wherein the composition (b) comprises (component b2) a (meth)acrylic acid alkyl ester having an alkyl group of an alkyl ester moiety having 1 to 3 carbon atoms. The surface protective film according to claim 8 or 9 , wherein the composition (b) comprises a mercaptan. The surface protective film according to any one of claims 8 to 10 , wherein the (meth)acrylic copolymer (B) has a Tg of 50°C to 250°C. The surface protective film according to any one of claims 8 to 11 , wherein the (meth)acrylic copolymer (B) has a weight average molecular weight of 1,000 to 30,000. The surface protection film according to any one of claims 1 to 12 , wherein the adhesive composition contains an ionic liquid. 14. The surface protective film according to claim 1, which generates 10 or less bubbles after high-temperature and high-pressure treatment. The surface protective film according to claim 14 , which is used to protect the surface of an adherend having a water contact angle of 60 degrees or more.

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