JP5258177B2 - Pressure-sensitive adhesive sheets for glass surface sticking and glass optical members - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive sheet for glass surface sticking and a glass optical member, and more specifically, even when directly attached to a glass surface, no discoloration or alteration occurs over time, and poor sticking. Pressure-sensitive adhesive sheets for application to glass surfaces, which can be easily peeled off from the glass surface during reworking, etc., and excellent in optical properties, and glass-made optics using the pressure-sensitive adhesive sheets for application to glass surfaces It relates to members.

In recent years, optical devices such as electronic displays have been widely used, and portions using pressure-sensitive adhesive sheets have been increasingly used in the configuration. For example, in a plasma display or the like, an optical filter containing glass is attached to a front plate, and at this time, a pressure-sensitive adhesive sheet (adhesive sheet) is directly attached to the glass (see Patent Document 1). Recently, a structure in which an optical filter is directly bonded to a plasma display panel has been put on the market.
JP 2003-268325 A

  However, optical filters and plasma display panels are often expensive, and when pressure-sensitive adhesive sheets are applied, poor bonding due to biting of foreign matter or bubbles (sticking failure) or failure in panel module lighting test When this occurs, there may be a case where a pressure-sensitive adhesive sheet is peeled off from the glass surface and is reapplied and reworked or repaired. However, if the adhesiveness between the pressure-sensitive adhesive sheets and the glass surface is too strong, the glass surface may be damaged at the time of peeling work, or the pressure-sensitive adhesive may remain on the glass surface. It becomes impossible to work, and it will be a big loss.

Accordingly, the object of the present invention is that even when directly applied to the glass surface, no discoloration or alteration occurs over time, and it can be easily peeled off from the glass surface during reworking and has excellent optical properties. Another object of the present invention is to provide a pressure-sensitive adhesive sheet for bonding a glass surface and a glass optical member using the pressure-sensitive adhesive sheet for bonding a glass surface.
Another object of the present invention is that the pressure-sensitive adhesive sheet for sticking to a glass surface having good transparency and the pressure-sensitive adhesive sheet for sticking to a glass surface are used, even under heating and humidification conditions. The object is to provide an optical member.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have determined that the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet has a specific acrylic monomer, a maleimide compound having a specific structure, and a specific copolymer. When formed with a pressure-sensitive adhesive composition based on a copolymer of a monomer mixture containing a polymerizable monomer at a specific ratio, over time, without causing discoloration or alteration on the glass surface, Further, the present inventors have found that when reworking or repairing due to a sticking failure or the like, the glass surface can be easily peeled off, and the optical characteristics are good even under high humidity heat. The present invention has been completed based on these findings.

（式（２）において、Ｒ³は炭素数１〜１４のアルキル基、３〜１２員環のシクロアルキル基、フェニル基、ナフチル基、ベンジル基及び２−フェニルエチル基から選択された炭化水素基（但し、前記炭化水素基は、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、ハロゲン原子及びニトロ基から選択された置換基を有していてもよい）を示す。）
（ｃ′）成分：カルボキシル基を含有しておらず、且つ（ａ）成分および（ｂ）成分と共重合が可能であり、（メタ）アクリル酸２−ヒドロキシエチル、（メタ）アクリル酸２−ヒドロキシプロピル、（メタ）アクリル酸３−ヒドロキシプロピル及び（メタ）アクリル酸４−ヒドロキシブチルから選択されたヒドロキシル基含有共重合性単量体、（メタ）アクリル酸グリシジルから選択されたエポキシ基含有共重合性単量体、酢酸ビニル及びプロピオン酸ビニルから選択されたビニルエステル系共重合性単量体から選ばれる少なくとも１つの単量体である他の単量体 That is, the present invention is a pressure-sensitive adhesive tape or sheet for directly sticking to a glass surface, and the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive tape or sheet comprises the following component (a) as a monomer: 84 to 94.6% by weight based on the total amount of the components, and the following component (b) is included at a rate of 5 to 15.6% by weight based on the total amount of the monomer components, and the following (c ′ ) Component in a proportion of 0.2 to 5% by weight with respect to the total amount of monomer components, and the content of the carboxyl group-containing copolymerizable monomer is 2% with respect to the total amount of monomer components. % Or less of a monomer mixture and a pressure-sensitive adhesive composition having a base polymer, and the adhesive strength of the pressure-sensitive adhesive layer is 1 to 7 (N / 20 mm) (vs. glass plate, temperature) : 23 ° C., humidity: 50% RH, peeling angle: 90 °, tensile speed: 300 m / Min; a pressure-sensitive adhesive tape or sheet bonded to a polyethylene terephthalate film having a thickness of 125 μm is bonded to a glass plate having a thickness of 1.3 mm, and then peeled off from the glass plate). A pressure-sensitive adhesive tape or sheet for application to a glass surface is provided.
(A) Component: Acrylic monomer represented by the following formula (1) CH ₂ = C (R ¹ ) COOR ² (1)
(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an s-butyl group, a t-butyl group, a pentyl group, an isoamyl group, Group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group or isodecyl group .)
(B) Component: Maleimide compound represented by the following formula (2)

(In the formula (2), R ³ is a hydrocarbon group selected from an alkyl group having 1 to 14 carbon atoms, a cycloalkyl group having 3 to 12 members, a phenyl group, a naphthyl group, a benzyl group and a 2-phenylethyl group. (However, the said hydrocarbon group may have a substituent selected from a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, and a nitro group) .
Component (c ′): does not contain a carboxyl group, and can be copolymerized with component (a) and component (b), (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2- A hydroxyl group-containing copolymerizable monomer selected from hydroxypropyl, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, an epoxy group-containing copolymer selected from glycidyl (meth) acrylate Another monomer that is at least one monomer selected from a polymerizable monomer, a vinyl ester copolymerizable monomer selected from vinyl acetate and vinyl propionate

The pressure-sensitive adhesive layer has a total light transmittance of 85% or more after heating and humidification treatment at 60 ° C. and 95% RH for 500 hours, and has a haze of 10% or less after the heating and humidification treatment. Further, it is preferable that the color difference (ΔE ^* ab) before and after the heating and humidification treatment is 0.5 or less.

Furthermore, the present invention is a structure in which a functional film is affixed to a glass surface, and the functional film is a glass surface using the pressure-sensitive adhesive tape or sheet for affixing a glass surface according to claim 1 or 2. Provided is a structure characterized in that it is affixed to. The structure is preferably a plasma display panel, a liquid crystal display device, or an organic EL display device.
In addition to the above-described invention, the present specification includes pressure-sensitive adhesive sheets for directly sticking to a glass surface, and the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheets includes the following (a): Ingredients are included in a proportion of 80 to 97.8% by weight with respect to the total amount of monomer components, and the following component (b) is included in a proportion of 2 to 19.8% by weight with respect to the total amount of monomer components. A monomer containing the following component (c) in a proportion of 0.2 to 5% by weight with respect to the total amount of the monomer components and substantially free of a carboxyl group-containing copolymerizable monomer. It is formed by the adhesive composition which uses the copolymer by a mixture as a base polymer, The adhesive strength of the said adhesive layer is 1-7 (N / 20mm) (to a glass plate, temperature: 23 degreeC, humidity: 50 % RH, peeling angle: 90 °, tensile speed: 300 mm / min; polyethylene having a thickness of 125 μm A pressure-sensitive adhesive sheet for application to a glass surface, wherein the pressure-sensitive adhesive sheets attached to a terephthalate film are attached to a glass plate having a thickness of 1.3 mm and then peeled off from the glass plate) The class is also explained.
(A) Component: Acrylic monomer represented by the formula (1)
(B) Component: Maleimide compound represented by the formula (2)
Component (c): other monomer that does not contain a carboxyl group and can be copolymerized with components (a) and (b)
The component (c ′) in the present invention is obtained by limiting the component (c) to a specific monomer.

  According to the pressure-sensitive adhesive sheets for glass surface sticking of the present invention, even if directly attached to the glass surface, no discoloration or alteration occurs over time, and it can be easily peeled off from the glass surface during rework. And has excellent optical properties. Further, transparency is good even under heating and humidification conditions.

（式（２）において、Ｒ³は水素原子又は１価の有機基を示す。）
（ｃ）成分：カルボキシル基を含有しておらず、且つ（ａ）成分および（ｂ）成分と共重合が可能な他の単量体 In the pressure-sensitive adhesive sheet for sticking to a glass surface of the present invention, the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet contains the following component (a) in an amount of 80 to 97.8 wt. The following component (b) is included at a ratio of 2 to 19.8% by weight based on the total amount of monomer components, and the following component (c) is included based on the total amount of monomer components: It is formed by a pressure-sensitive adhesive composition comprising a copolymer of a monomer mixture containing 0.2 to 5% by weight of a monomer mixture substantially free of a carboxyl group-containing copolymerizable monomer. The adhesive strength of the pressure-sensitive adhesive layer is 1 to 7 (N / 20 mm) (to glass plate, temperature: 23 ° C., humidity: 50% RH, peeling angle: 90 °, tensile speed: 300 mm / min; thickness Pressure-sensitive adhesive bonded to a 125 μm polyethylene terephthalate film The sheets are attached to a glass plate having a thickness of 1.3 mm and then peeled off from the glass plate).
(A) Component: Acrylic monomer represented by the following formula (1) CH ₂ = C (R ¹ ) COOR ² (1)
(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 2 to 14 carbon atoms.)
(B) Component: Maleimide compound represented by the following formula (2)

(In Formula (2), R ³ represents a hydrogen atom or a monovalent organic group.)
Component (c): other monomer that does not contain a carboxyl group and can be copolymerized with components (a) and (b)

  As described above, the pressure-sensitive adhesive sheets for glass surface sticking of the present invention include a specific acrylic as a monomer main component in the monomer component constituting the base polymer of the pressure-sensitive adhesive layer forming the pressure-sensitive adhesive layer. And a monomeric compound [(b) component] having a specific structure as a copolymerizable monomer component for the acrylic monomer and a specific copolymer. Since it contains a polymerizable monomer [component (c)] and does not substantially contain a carboxyl group-containing monomer (preferably an acidic group-containing copolymerizable monomer), the glass surface When affixed to, the glass surface is not discolored or altered, and the optical properties of the adherend are not impaired. In addition, when performing rework work due to poor adhesion due to entrapment of foreign matter or bubbles when pasting to the glass surface, or when performing repair work due to problems in performance confirmation tests such as panel module lighting tests, It can be easily peeled from the glass surface without causing the adhesive component to remain or damage the glass surface. Furthermore, the optical characteristics can also be made good, and in particular, the transparency can be made good even under high humidity heat. Of course, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is the acrylic monomer [(a) component], the maleimide compound [(b) component] and the copolymerizable monomer [(c) component]. Since it has a specific amount of the corresponding structural unit, it can exhibit excellent adhesive properties and the like.

  In the present invention, the monomer mixture in the copolymer as the base polymer according to the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer includes a carboxyl group-containing copolymerizable monomer (more preferably an acidic group). It is important that the copolymerizable monomer is not substantially contained. When the carboxyl group-containing copolymerizable monomer is substantially contained in the copolymer (acrylic copolymer) as the base polymer, it has adequate adhesion to the glass surface and adhesive residue when re-peeling The problem that preventability will fall remarkably arises and the removability of the pressure-sensitive adhesive sheets for glass surface sticking will fall. “Containing substantially no carboxyl group-containing copolymerizable monomer” means that the pressure-sensitive adhesive sheet for glass surface sticking can be used as long as it can maintain excellent removability. It means that a polymerizable monomer may be contained. Specifically, in the monomer mixture in the copolymer as the base polymer, the content of the carboxyl group-containing copolymerizable monomer is, for example, 2% by weight or less based on the total amount of the monomer components ( 0 to 2% by weight), preferably 1% by weight or less (particularly 0.5% by weight or less). Thus, when the ratio of the carboxyl group-containing copolymerizable monomer is 2% by weight or less based on the total amount of the monomer components, the removability of the pressure-sensitive adhesive sheets for glass surface sticking is excellent. The pressure-sensitive adhesive sheets for sticking to a glass surface can be easily peeled off from the glass surface without leaving an adhesive component on the glass surface and without damaging the glass surface.

  Examples of the carboxyl group-containing copolymerizable monomer include (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acidic group-containing copolymerizable monomer other than the carboxyl group-containing copolymerizable monomer include, for example, anhydrides of carboxyl group-containing copolymerizable monomers such as maleic anhydride and icotanic anhydride; styrene Contains sulfonic acid groups such as sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid Copolymerizable monomer; phosphate group-containing copolymerizable monomer such as 2-hydroxyethylacryloyl phosphate;

[(A) component]
The component (a) is an acrylic monomer represented by the formula (1) (sometimes referred to as “acrylic monomer (a)”). In the formula (1), examples of the alkyl group having 2 to 14 carbon atoms according to R ² include an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, a t-butyl group, Examples include pentyl group, isoamyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, dodecyl group, tridecyl group and tetradecyl group. . When the carbon number of R ² is less than 2, the glass transition temperature (Tg) of the resulting copolymer is increased, thereby reducing the wettability as a pressure-sensitive adhesive (pressure-sensitive adhesive) and initial adhesiveness. (Tackiness) deteriorates. Further, the number of carbon atoms of R ² exceeds 14, undesirably the adhesive strength of the pressure-sensitive adhesive is poor.

  Specifically, as the acrylic monomer (a), for example, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic Isobutyl acid, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, ( Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, Undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Meth) including tetradecyl acrylate.

  As the acrylic monomer (a), ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic 2-ethylhexyl acid, isooctyl (meth) acrylate, isononyl (meth) acrylate, and isodecyl (meth) acrylate can be preferably used.

  In addition, an acryl-type monomer (a) can be used individually or in combination of 2 or more types.

  The acrylic monomer (a) is 80 to 97.8% by weight (preferably 82%) based on the total amount of monomer components in the copolymer as the base polymer of the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer. -96.7% by weight, more preferably 84-94.6% by weight). When the proportion of the acrylic monomer (a) is less than 80% by weight relative to the total amount of the monomer components, the glass transition temperature (Tg) of the resulting copolymer is increased, and the pressure-sensitive adhesive Performance decreases. On the other hand, when the proportion of the acrylic monomer (a) exceeds 97.8% by weight with respect to the total amount of the monomer components, the proportion (absolute amount) of the component (b) is lowered to form. The adhesive performance of the pressure-sensitive adhesive layer is reduced.

[Component (b)]
The component (b) is a maleimide compound represented by the formula (2) (sometimes referred to as “maleimide compound (b)”). In the above formula (2), the monovalent organic group related to R ³ is not particularly limited as long as it does not impair the polymerizability, adhesive properties, etc. For example, the hydrocarbon which may have a substituent Group and the like. Hydrocarbon groups include, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2- Alkyl groups such as ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group (lauryl group), tridecyl group, tetradecyl group (for example, alkyl groups having 1 to 14 carbon atoms); cyclopentyl group, cyclohexyl group, etc. A cycloalkyl group (for example, a 3- to 12-membered cycloalkyl group); an aryl group such as a phenyl group or a naphthyl group; an aralkyl group such as a benzyl group or a 2-phenylethyl group; Examples of the substituent include an alkyl group such as a methyl group (for example, an alkyl group having 1 to 4 carbon atoms), an alkoxy group such as a methoxy group (for example, an alkoxy group having 1 to 4 carbon atoms), A halogen atom such as a chlorine atom, a nitro group and the like can be mentioned. Representative examples of the hydrocarbon group having a substituent include 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2-methoxyphenyl group, 3-methoxyphenyl group, 4-methoxyphenyl group, Examples include 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2-nitrophenyl group, 3-nitrophenyl group, 4-nitrophenyl group.

In addition, it is preferable that the monovalent organic group of R ³ does not contain a carboxyl group (particularly an acidic group). Examples of acidic groups other than carboxyl groups include sulfonic acid groups and phosphoric acid groups.

  Specifically, as the maleimide compound (b), for example, maleimide; N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N- s-Butylmaleimide, Nt-butylmaleimide, N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N- (2-ethylhexyl) maleimide, N-nonylmaleimide, N-decylmaleimide N-alkylmaleimides such as N-undecylmaleimide, N-laurylmaleimide, N-tridecylmaleimide and N-tetradecylmaleimide; N-cycloalkylmaleimides such as N-cyclopentylmaleimide and N-cyclohexylmaleimide; N- Various substituents (for example, alkyl groups, alkoxy groups, halogen atoms, nitro groups, etc.) on hydrocarbon groups (alkyl groups, cycloalkyl groups, aryl groups, etc.) in N-arylmaleimides such as enylmaleimides and these maleimide compounds ) Substituted maleimide compounds and the like.

  In addition, a maleimide type compound (b) can be used individually or in combination of 2 or more types.

  The maleimide compound (b) is 2 to 19.8% by weight (preferably 3 to 17%) based on the total amount of monomer components in the copolymer as the base polymer of the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer. 0.7 wt%, more preferably 5 to 15.6 wt%). When the proportion of the maleimide compound (b) is less than 2% by weight with respect to the total amount of the monomer components, the adhesive performance of the pressure-sensitive adhesive layer to be formed is deteriorated, whereas when it exceeds 19.8% by weight, Problems arise in peelability during rework.

[Component (c)]
The component (c) does not contain a carboxyl group and can be copolymerized with the components (a) and (b) (referred to as “copolymerizable monomer (c)”). May be). By using the copolymerizable monomer (c), various properties of the pressure-sensitive adhesive, the structure of the copolymer, and the like can be controlled. For example, when a copolymerizable monomer having a functional group (polar group such as hydroxyl group) other than a carboxyl group (particularly an acidic group) is used as the copolymerizable monomer (c), a copolymer (acrylic) is used. Crosslinks can be generated in the polymer). In addition, a copolymerizable monomer (c) can be used individually or in combination of 2 or more types.

  The copolymerizable monomer (c) does not contain a carboxyl group (more preferably does not contain an acidic group), and includes an acrylic monomer (a) and a maleimide compound (b). The copolymer is not particularly limited as long as it is a copolymerizable monomer. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) 4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, glycerin dimethacrylate, (meth) acrylic acid Copolymerizability of hydroxyl group such as polyethylene glycol and polypropylene glycol (meth) acrylate Mer; epoxy group-containing copolymerizable monomer such as glycidyl (meth) acrylate; methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, (meth) acrylic Alkoxy group-containing copolymerizable monomers such as acid methoxypolypropylene glycol; (meth) acrylamide, N-substituted (meth) acrylamide (for example, N-ethyl (meth) acrylamide, Nn-butyl (meth) acrylamide, etc.) N-alkyl (meth) acrylamide; N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, -N, N-dialkyl (meth) acrylamides such as di (t-butyl) (meth) acrylamide; hydroxyls such as N-methylol (meth) acrylamide, N-ethylol (meth) acrylamide, N-methylolpropane (meth) acrylamide Group-containing (meth) acrylamide, etc.), amide group-containing copolymerizable monomers such as N-vinylcarboxylic acid amides; N-vinylpyrrolidone, N-vinylpyridine, N-vinylmorpholine, N- (meth) acryloylmorpholine N-vinyl nitrogen-containing heterocyclic compounds such as N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-2-ethylhexylitaconimide, N-lauryl itaconimide, N-cyclohexyl leuconconimide Itaconimide monomer; (meth) a Amino group-containing copolymerizable monomers such as aminoethyl acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate; cyano groups such as (meth) acrylonitrile -Containing copolymerizable monomers; styrene-based copolymerizable monomers such as styrene and α-methylstyrene; α-olefin-based copolymerizable monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; 2-methacryloyl Isocyanate group-containing copolymerizable monomers such as oxyethyl isocyanate; vinyl ester copolymerizable monomers such as vinyl acetate and vinyl propionate; vinyl ether copolymerizable monomers such as vinyl ether; (meth) acrylic acid Heterocycle-containing (meth) acrylic acid esters such as tetrahydrofurfuryl; Fluorine (meth) acrylate A halogen atom-containing copolymerizable monomer such as a salt; a silicon atom-containing copolymerizable monomer such as silicone (meth) acrylate; a methyl (meth) acrylate or an alkyl group having a carbon number of 15 or more ( (Meth) acrylic acid alkyl ester; (meth) acrylic acid ester having an alicyclic hydrocarbon group such as (meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid bornyl, (meth) acrylic acid isobornyl (Meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate; ethylene glycol di ( (Meth) acrylate, diethylene glycol di (meth) acrylate, Liethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hexanediol Di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinyl Examples thereof include polyfunctional monomers such as benzene, butyl di (meth) acrylate, and hexyl di (meth) acrylate.

  As the copolymerizable monomer (c), a hydroxyl group-containing copolymerizable monomer, an epoxy group-containing copolymerizable monomer, and a vinyl ester copolymerizable monomer can be preferably used. Hydroxyl group-containing copolymerizable monomers [especially 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate] are preferred. By using a hydroxyl group-containing copolymerizable monomer [particularly, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate] as the copolymerizable monomer (c), the glass surface The pressure-sensitive adhesive sheets for sticking can more effectively exhibit appropriate adhesiveness to the glass surface.

  The copolymerizable monomer (c) is 0.2 to 5% by weight (preferably with respect to the total amount of monomer components in the copolymer as the base polymer of the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer). 0.3 to 3% by weight, more preferably 0.4 to 2.5% by weight). When the proportion of the copolymerizable monomer (c) is less than 0.2% by weight based on the total amount of the monomer components, it is difficult to form an appropriate crosslinked structure for the purpose of maintaining the shape of the pressure-sensitive adhesive layer. . On the other hand, when the ratio of the copolymerizable monomer (c) exceeds 5% by weight based on the total amount of the monomer components, it is difficult for the resulting copolymer to effectively exhibit the performance as an acrylic polymer. In addition, it becomes difficult to balance the characteristics as a pressure-sensitive adhesive.

[Copolymer by monomer mixture]
The copolymer as the base polymer in the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer is the monomer component [acrylic monomer (a), maleimide compound (b), copolymerizable monomer. (C)] is an acrylic copolymer obtained by polymerization (copolymerization) of a monomer mixture containing a predetermined ratio. The acrylic copolymer as the base polymer can be used alone or in combination of two or more.

  As a polymerization method for obtaining an acrylic copolymer, for example, a polymerization method (solution) performed using a polymerization initiator such as an azo compound (azo initiator) or a peroxide (peroxide initiator) Polymerization methods, emulsion polymerization methods, bulk polymerization methods, etc.), polymerization methods carried out by irradiating light or radiation using a photoinitiator, etc., and polymerization methods carried out using an azo initiator are suitable. is there. In the polymerization initiator, examples of the azo initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2 -Methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-dimethyleneisobutyl) Amidine) dihydrochloride and the like. Examples of the peroxide initiator include dibenzoyl peroxide and tert-butyl permaleate. Furthermore, as photoinitiators, for example, acetophenone-based initiators such as 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, methoxyacetophenone, etc. Benzoin ether initiators such as benzoin ethyl ether; ketal initiators such as benzyldimethyl ketal; halogenated ketones; acyl phosphinoxides; acyl phosphonates.

  The amount of the polymerization initiator used is not particularly limited, and is, for example, about 0.01 to 2 parts by weight (preferably 0.02 to 1 part by weight) with respect to 100 parts by weight of the total amount of monomer components.

  In the present invention, the acrylic copolymer obtained by polymerization using the monomer mixture may be used after being dried as it is, or it may be used after being cured by crosslinking the acrylic copolymer. Also good. By crosslinking the acrylic copolymer, good results can be obtained in durability such as heat resistance in addition to the peelability and adhesiveness of the release liner. The crosslinking method of the acrylic copolymer is not particularly limited, and any crosslinking method can be used, but a method using a so-called crosslinking agent is desirable. The acrylic copolymer can be crosslinked during or after the formation of the pressure-sensitive adhesive layer.

  As the crosslinking agent, conventionally known ones can be used, but isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, and melamine compounds are preferable, and isocyanate compounds are particularly preferable. A crosslinking agent can be used individually or in mixture of 2 or more types. Examples of the isocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, diphenylmethane diisocyanate double product, reaction product of trimethylolpropane and tolylene diisocyanate, trimethylolpropane and hexaxylene. A reaction product with methylene diisocyanate, polyether polyisocyanate, polyester polyisocyanate and the like can be mentioned. In addition, the usage-amount of crosslinking agents, such as an isocyanate type compound, is about 0.01-20 weight part (preferably 0.05-15 weight part) with respect to 100 weight part of acrylic copolymers, for example.

The weight average molecular weight of the acrylic copolymer is not particularly limited, but is preferably 200,000 to 2,000,000, and particularly preferably 500,000 to 2,000,000 (particularly 700,000 to 1,500,000). In addition, the weight average molecular weight of an acryl-type copolymer is the value measured on the following measurement conditions by standard polystyrene conversion of the gel permeation chromatography method (GPC method).
Measurement conditions for GPC method GPC measurement device: trade name “HLC-8120GPC” (manufactured by Tosoh Corporation)
Column: Trade name “TSKgelSuperHM-H / H4000 / H3000 / H2000” (manufactured by Tosoh Corporation)
・ Eluent: Tetrahydrofuran (THF)
Sample concentration: 0.2% by weight (tetrahydrofuran solution)
Sample injection volume: 10 μl
・ Flow rate (flow velocity): 0.6 mL / min
Column temperature (measurement temperature): 40 ° C
・ Detector: Differential refractometer (RI)

[Adhesive composition]
The pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer has, as a base polymer, the monomer component [acrylic monomer (a), maleimide compound (b), copolymerizable monomer (c)]. Is contained in a predetermined proportion of an acrylic copolymer obtained by polymerization (copolymerization) of a monomer mixture. Various additives may be added to the pressure-sensitive adhesive composition as necessary. Examples of such additives include known or commonly used tackifying resins (for example, rosin resins, terpene resins, petroleum resins, coumarone / indene resins, styrene resins, etc.), fillers, colorants (pigment and Dyes, etc.), various known additives such as antioxidants, ultraviolet absorbers, and surfactants. The amount of these additives used may be a normal amount applied to the pressure-sensitive adhesive.

  The pressure-sensitive adhesive composition can take any form during the preparation process, but is preferably used in the form of a solvent system, an emulsion system, a hot melt system, a photopolymerization system, etc. from the viewpoint of handleability. An adhesive composition can be used individually or in combination of 2 or more types.

[Pressure-sensitive adhesive sheets for glass surface application]
The pressure-sensitive adhesive sheet for glass surface sticking of the present invention has a pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition (sometimes referred to as “glass surface sticking pressure-sensitive adhesive layer”). The pressure-sensitive adhesive layer for glass surface sticking may have either a single layer or a laminate. Although it does not restrict | limit especially as a thickness of the adhesive layer for glass surface sticking, 5-70 micrometers is preferable and especially 10-50 micrometers is suitable. When the thickness of the pressure-sensitive adhesive layer for glass surface sticking is less than 5 μm, the adhesion to the glass surface becomes poor, and when it exceeds 70 μm, the light transmittance loss due to the thickness of the pressure-sensitive adhesive layer for glass surface sticking itself is large. Therefore, it is not preferable.

  In addition, the formation method in particular of the adhesive layer for glass surface sticking is not restrict | limited. For example, the pressure-sensitive adhesive composition can be applied to a predetermined surface (for example, a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, etc.). The adhesive layer for sticking to the glass surface can be formed by applying to a release surface of the release liner or the surface of the substrate.

  In the present invention, the pressure-sensitive adhesive layer for glass surface sticking is 1 to 7 (N / 20 mm) (to glass plate, temperature: 23 ° C., humidity: 50% RH, peeling angle: 90 °, tensile speed: 300 mm / min; It is important that the pressure-sensitive adhesive sheets bonded to a polyethylene terephthalate film having a thickness of 125 μm are bonded to a glass plate having a thickness of 1.3 mm and then peeled off from the glass plate). It is. Thus, since the adhesive strength of the pressure-sensitive adhesive layer for glass surface application is within the above range, the pressure-sensitive adhesive sheets for glass surface application of the present invention can be easily peeled off from the glass surface to which the glass surface is applied during rework. Can be made. Therefore, the pressure-sensitive adhesive sheets for glass surface sticking are used as re-peelable pressure-sensitive adhesive sheets for glass face sticking.

  Adhesive strength of adhesive layer for glass surface sticking (to glass plate, temperature: 23 ° C., humidity: 50% RH, peeling angle: 90 °, tensile speed: 300 mm / min; bonded to a polyethylene terephthalate film with a thickness of 125 μm The pressure-sensitive adhesive sheets are attached to a glass plate having a thickness of 1.3 mm and then peeled off from the glass plate), so long as it is 1 to 7 (N / 20 mm). ~ 6 (N / 20 mm). If the adhesive strength of the pressure-sensitive adhesive layer for glass surface sticking is less than 1 (N / 20 mm), it may be peeled undesirably due to mild vibration or impact, making it difficult to obtain good results. On the other hand, if the adhesive strength of the pressure-sensitive adhesive layer for sticking to the glass surface exceeds 7 (N / 20 mm), it becomes difficult to perform the peeling work during reworking, and the glass surface that is the surface of the adherend (attachment surface) It becomes easy to cause troubles, such as damaging the member to be included or the pressure-sensitive adhesive remaining on the glass surface.

  In the present invention, the adhesive strength of the pressure-sensitive adhesive layer for attaching a glass surface is a glass plate having a thickness of 1.3 mm as an adherend (“Slide glass white edge polish” manufactured by Matsunami Glass Industry Co., Ltd .; thickness 1.3 mm). The pressure-sensitive adhesive sheet for glass surface application is bonded to a polyethylene terephthalate film having a thickness of 125 μm in such a manner that the surface opposite to the adhesive layer for glass surface application is in contact with the polyethylene terephthalate film. After fixing the pressure-sensitive adhesive sheet for glass surface application to the film, the pressure-sensitive adhesive sheet for glass surface application contacts the glass plate as the adherend, and the adhesive layer for glass surface application contacts the surface of the glass plate. And left in an atmosphere of temperature: 23 ° C. and humidity: 50% RH for 48 hours, and then an atmosphere of temperature: 23 ° C. and humidity: 50% RH Under pressure, the peeling angle: 90 °, the tensile speed: 300 mm / min. The pressure-sensitive adhesive sheets for glass surface pasting bonded to the polyethylene terephthalate film with a thickness of 125 μm were peeled off from the glass plate, and this peeling It is obtained by measuring the stress at the time, reading the stress value at four points at intervals of 20 mm, calculating the average value of the stress at the four points, and setting the average value of the stress as the peel strength (N / 20 mm). Defined as

  As a pressure sensitive adhesive sheet for glass surface sticking, the structure will not be restrict | limited especially if it has the said adhesive layer for glass face sticking. Specifically, examples of the pressure-sensitive adhesive sheets for glass surface sticking include (1) base material-less double-sided pressure-sensitive adhesive sheets having a configuration formed only from a pressure-sensitive adhesive layer for glass face sticking, (2) base A double-sided pressure-sensitive adhesive sheet with a substrate having a structure in which a pressure-sensitive adhesive layer for glass surface sticking is formed on at least one surface of the material and an adhesive surface is formed on both surfaces of the substrate; (3) one of the substrates Examples thereof include a pressure-sensitive adhesive sheet with a substrate having a structure in which a pressure-sensitive adhesive layer for attaching a glass surface is formed on the surface.

  In addition, when the pressure sensitive adhesive sheet for glass surface sticking is a double-sided pressure sensitive adhesive sheet with a base material, the pressure sensitive adhesive layer (pressure sensitive adhesive layer) formed on both surfaces of the base material is a pressure sensitive adhesive layer for glass surface sticking. The pressure-sensitive adhesive layer formed on one surface of the substrate may be a pressure-sensitive adhesive layer for bonding to the glass surface, and the pressure-sensitive adhesive layer formed on the other surface of the substrate may be bonded to the glass surface. It may be a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer (sometimes referred to as “a non-glass-faced pressure-sensitive adhesive layer”). When the pressure sensitive adhesive sheet for glass surface sticking has a non-glass surface sticking pressure-sensitive adhesive layer, it is important that the non-glass surface sticking pressure-sensitive adhesive layer is not used for the glass surface.

  Moreover, the pressure sensitive adhesive sheets for glass surface sticking may be formed in the form wound by roll shape, and may be formed in the form by which the sheet | seat was laminated | stacked. That is, the pressure-sensitive adhesive sheets for sticking to a glass surface of the present invention can have forms such as a sheet form and a tape form. Accordingly, the pressure-sensitive adhesive sheets for glass surface application include pressure-sensitive adhesive tapes or pressure-sensitive adhesive sheets (pressure-sensitive adhesive tapes or sheets). In addition, when the pressure sensitive adhesive sheet for glass surface sticking has the form wound by roll shape (when it is a pressure sensitive adhesive tape), for example, pressure sensitive adhesives, such as an adhesive layer for glass face sticking It can be produced by winding the agent layer in a roll shape in a state protected by a release liner (separator) or a release treatment layer formed on the back side of the substrate.

  The pressure-sensitive adhesive sheets for glass surface sticking of the present invention are the pressure-sensitive adhesive sheets for glass surface sticking of the above constitution (1), that is, the substrate-less double-sided structure having a configuration formed only from the pressure-sensitive adhesive layer for glass surface sticking. Pressure sensitive adhesive sheets are preferred. Such substrate-less double-sided pressure-sensitive adhesive sheets preferably have a form in which a pressure-sensitive adhesive layer for glass surface sticking is formed on a release liner.

  The release liner is not particularly limited as long as it is used as an adhesive tape or a release liner for a sheet, and a known release liner can be used. The release liner may be a release surface on both sides, or only one of the surfaces may be a release surface. Therefore, the pressure-sensitive adhesive sheets for glass surface sticking are roll-shaped in which a release liner having both surfaces peeled is laminated on one side of the glass surface sticking pressure-sensitive adhesive layer and wound into a roll shape. Or by using two release liners with one side being a release surface, each release liner is laminated on each side of the adhesive layer for glass surface application, and further required Depending on, it may be formed in the form of a sheet wound in a roll shape or a roll shape.

  Specific examples of the release liner include, for example, a release treatment agent layer made of a release treatment agent, a release liner base material (for example, paper such as Japanese paper, western paper, glassine paper; fibrous materials such as nonwoven fabric and cloth) Base material by: linear low density polyethylene film, low density polyethylene film, high density polyethylene film, polypropylene film, poly-4-methyl-1-pentene film, polyamide film, polyester film, polystyrene film, polyvinyl chloride film, etc. Release liners formed on the surface of plastic films, metal-deposited plastic films, etc., and plastic films with high peelability per se [eg, polyethylene (linear low density polyethylene, etc.), polypropylene, ethylene-propylene copolymer Ethylene-α In addition to olefin copolymers (block copolymers or random copolymers), release films made of polyolefin resins made of a mixture of these, polyolefin-based films; Teflon (registered trademark) films, etc.], high-peelable plastics Film materials (for example, polyolefin resins such as polyethylene-polypropylene, ethylene-α-olefin copolymers such as ethylene-propylene copolymer, Teflon, etc.), various substrates (for example, metal foil, plastic film, For example, a release liner obtained by laminating or coating paper or the like.

  The release treatment agent is not particularly limited, and examples thereof include known release treatment agents such as silicone release treatment agents, fluorine release treatment agents, and long-chain alkyl release treatment agents. These release treatment agents can be used alone or in combination. In addition, when both surfaces of the release liner are formed of a release treatment agent, the release treatment agents for forming both release surfaces may be the same or different.

  In addition, when the pressure sensitive adhesive sheet for glass surface sticking has a base material [that is, the double-sided pressure sensitive adhesive sheet with a base material of the above-mentioned composition (2), or with a base material of the above-mentioned composition (3) In the case of pressure-sensitive adhesive sheets], as the substrate, for example, a paper-based substrate such as paper; a fiber-based substrate such as cloth, nonwoven fabric or net; a metal-based substrate such as metal foil or metal plate; plastic Plastic base materials such as films and sheets; Rubber base materials such as rubber sheets; Foams such as foam sheets and laminates thereof (particularly laminates of plastic base materials and other base materials; A suitable thin leaf body such as a laminate of plastic films (or sheets) can be used. As the substrate, a plastic substrate such as a plastic film or sheet can be suitably used. As a material in such a plastic film or sheet, for example, an α-olefin such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) or the like is used as a monomer component. Olefin resin: Polyester resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); polyvinyl chloride (PVC); vinyl acetate resin; polyphenylene sulfide (PPS); polyamide (Nylon), amide resins such as wholly aromatic polyamide (aramid); styrene resins such as polystyrene; polyimide resins; polyether ether ketone (PEEK). These materials can be used alone or in combination of two or more.

  In addition, it is desirable to use what has the outstanding transparency as a base material.

  Although the thickness of a base material is 1-1000 micrometers (preferably 1-500 micrometers, more preferably 3-300 micrometers), for example, it is not limited to these. In addition, the base material may have a single layer form or may have a laminated form.

  In order to improve the adhesion of the surface of the base material to the adhesive layer for sticking to the glass surface, etc., conventional surface treatments such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation treatment, etc. These may be subjected to an oxidation treatment or the like by a chemical or physical method, or may be subjected to a coating treatment with an undercoat agent or a release agent.

  Moreover, when the pressure-sensitive adhesive sheet for glass surface sticking has a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer for glass face sticking [that is, the double-sided pressure-sensitive adhesive sheet with a base material of the configuration (2)] In the case where a pressure-sensitive adhesive layer for non-glass surface sticking is used], the pressure-sensitive adhesive layer for non-glass surface sticking is a known pressure-sensitive adhesive (for example, other acrylic pressure-sensitive adhesives, rubber-based feelings). Pressure-sensitive adhesive, vinyl alkyl ether-based pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, polyester-based pressure-sensitive adhesive, polyamide-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, fluorine-based pressure-sensitive adhesive, epoxy-based It can be formed using a known pressure-sensitive adhesive layer forming method using a pressure-sensitive adhesive or the like. Further, the thickness of the non-glass surface sticking pressure-sensitive adhesive layer is not particularly limited, and can be appropriately selected according to the purpose and the method of use.

In addition, the pressure-sensitive adhesive sheets for sticking to a glass surface of the present invention maintain high transparency even when exposed to high temperature and / or high humidity during pretreatment, various manufacturing process stages, product use, etc. Can do. Specifically, as the pressure-sensitive adhesive layer for glass surface application in the pressure-sensitive adhesive sheet for glass surface application, the total light transmittance before and after the heating and humidification treatment at 60 ° C. and 95% RH for 500 hours is The haze is 85% or more both before and after the humidification treatment, and the haze is 10% or less both before and after the heat humidification treatment. Further, the color difference (ΔE ^* ab) before and after the heat humidification treatment is 0.5. It can have the following characteristics: If the pressure-sensitive adhesive layer for glass surface sticking has such characteristics, even if it receives a heat history due to high heat and / or a humidity history due to high humidity, it can effectively retain excellent optical properties. . Specifically, the pressure-sensitive adhesive layer for sticking to the glass surface has the characteristics that even when exposed to high temperatures and high humidity, it maintains yellowness without transparency (maintains) and has little change in hue. It can be demonstrated.

  Specifically, the pressure-sensitive adhesive layer for glass surface sticking has a total light transmittance of 85% or more both at 60 ° C. and 95% RH for 500 hours before the heating and humidifying treatment and after the heating and humidifying treatment ( Preferably 90% or more).

  The adhesive layer for sticking to the glass surface has a haze of 10% or less (preferably 5% or less) both before and after the heating and humidifying treatment at 60 ° C. and 95% RH for 500 hours. It can have the following characteristics.

Further, the pressure-sensitive adhesive layer for glass surface sticking has a color difference (ΔE ^* ab) of 0.5 or less (0 to 0) before and after the heating and humidification treatment at 60 ° C. and 95% RH for 500 hours. 0.5) [preferably 0.3 or less (0 to 0.3)]. That the color difference (ΔE ^* ab) is 0.5 or less means that the color change is at a slightly different level.

In the present invention, the total light transmittance, haze, and color difference (ΔE ^* ab) of the pressure-sensitive adhesive layer for glass surface sticking are values measured by the following measuring methods.
(Measurement method of total light transmittance and haze)
A 25 μm thick adhesive layer for glass surface application (area: 40 mm × 40 mm) is formed, and a slide glass (“Slide glass white edge polish” manufactured by Matsunami Glass Industrial Co., Ltd.) is formed on one side of the adhesive layer for glass surface application. A sample having a thickness of 1.3 mm) (that is, a layer having a glass / glass surface adhesive layer) is used as an evaluation sample. Measure the total light transmittance (%) and haze (%) of the sample for evaluation according to JIS K7361 and JIS K7136 using a turbidimeter (device name “Hazemeter HM-150” manufactured by Murakami Color Research Laboratory). (Before heating and humidification treatment) Thereafter, the sample for evaluation is heated and humidified at 60 ° C. and 95% RH for 500 hours, and then the total light transmittance (%) and haze (%) of the sample for evaluation are measured in the same manner as described above. .

(Measurement method of color difference (ΔE ^* ab))
For an evaluation sample similar to the evaluation sample (evaluation sample before the heat treatment) prepared by the above-described total light transmittance / haze measurement method, an integrating sphere type spectral transmittance measuring device (device name “DOT-3C” Murakami) Using the Color Technology Laboratory), the X, Y, and Z values of the XYZ color system specified in JIS Z8701 are converted to CIE L ^* a ^* b ^* color system specified in JIS Z8729. L ^* , a ^* , and b ^{* obtained} are measured (C light source, 2 ° field of view, wavelength: 390 nm to 730 nm) (before heating and humidification treatment). Thereafter, the sample for evaluation was heated and humidified at 60 ° C. and 95% RH for 500 hours, and in the same manner as described above, the sample for evaluation after the heat and humidified treatment at 60 ° C. and 95% RH for 500 hours was obtained. L ^* , a ^* , b ^* are measured.
From the obtained values of L ^* , a ^* , and b ^* , the color difference (ΔE ^* ab) before and after the heat and humidification treatment is calculated using the following equation.
ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2
(Here, [Delta] L ^* is .Δb means the difference between before and after the L ^* values of the heating humidification .Derutaei ^* is that means the difference before and after a ^* values of the heating humidification ^* heating (This means the difference in b ^* values before and after humidification.)

  Since the pressure-sensitive adhesive sheets for glass surface sticking of the present invention have the above-described configuration, even when directly attached to the glass surface, no discoloration or alteration occurs over time, and excellent adhesive properties and Can be affixed to the glass surface with optical properties. Therefore, it can be suitably used as a pressure-sensitive adhesive sheet for directly sticking to a glass surface in an adherend having a glass surface. In addition, what is necessary is just to bond at least partially (partially or entirely) directly to a glass surface, when bonding the pressure-sensitive adhesive sheet for glass surface bonding to a glass surface.

  The adherend to which the pressure-sensitive adhesive sheet for sticking a glass surface is bonded (sometimes referred to as a “glass surface-containing adherend”) is not particularly limited as long as it has at least a glass surface. In such a glass surface-containing adherend, the portion where the glass surface is formed is not particularly limited as long as it is a portion where the pressure-sensitive adhesive sheet for glass surface sticking can be directly attached, and the outer surface. It may also be an inner surface or the like. When a plurality of glass surfaces are formed on one glass surface-containing adherend, the plurality of glass surfaces may be surfaces formed of the same glass material or formed of different glass materials. It may be a surface.

  The glass surface of the glass surface-containing adherend may be the surface of a glass surface-containing adherend formed of a glass material, or on the surface of a base material (or structure) formed of various materials. The formed glass layer surface may be sufficient. In any case, the glass surface may be a surface made of a glass material. The said glass layer can be formed in the predetermined site | part of the surface of the base material (or structure) comprised with various materials. Note that the glass surface may be formed uniformly in a layered shape, or may be partially formed in a pattern shape by etching, printing, or the like.

  It does not restrict | limit especially as thickness of a glass layer, According to the kind of glass surface containing adherend, it can select suitably, For example, it can select suitably from the range of 0.2-5 mm.

It does not restrict | limit especially as a glass material for forming a glass surface, It can select suitably from well-known glass materials. The glass material usually contains one or more inorganic oxides. The inorganic oxide is not particularly limited as long as it is an oxide containing an inorganic element such as a metal element or an inorganic nonmetallic element. For example, SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , Li ₂ O, Na ₂ O, K ₂ O, MgO, CaO, SrO, BaO, ZnO, TiO ₂ , ZrO ₂ , PbO, P ₂ O ₅ , Y ₂ O ₃ , Nb ₂ O ₅ , Ta ₂ O ₅ , lanthanoid series Metal oxide (La ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ etc.), Sb ₂ O ₃ , As ₂ O ₅ , TeO ₂ , Cu ₂ O, Fe ₂ O ₃ , FeO, CoO, NiO, Cr ₂ O ₃ , SnO ₂ , Bi ₂ O _{3 and the} like. Further, the glass material may contain SO ₃ , fluorine atoms or the like as necessary.

  The glass surface to which the pressure-sensitive adhesive sheets for glass surface application are directly attached may be the surface of glass (glass that has not been surface-treated), or the surface of glass that has been subjected to various surface treatments ( It may also be a surface that has been subjected to a surface treatment. Such glass is not particularly limited, and examples thereof include float plate glass and surface-coated plate glass.

  Examples of the glass surface-containing adherend include various members for constituting an optical product having a glass layer. Examples of the optical product include optical devices such as various display devices such as a plasma display panel, a liquid crystal display device, and an organic EL display device. Moreover, a glass substrate etc. are illustrated as a member.

  The pressure-sensitive adhesive sheets for glass surface sticking of the present invention are, for example, when bonding various functional films and sheets such as antireflection films and electromagnetic wave shielding sheets to various structures having a glass surface such as a glass substrate. It can be preferably used. Examples of such a structure include various display devices such as a plasma display panel, a liquid crystal display device, and an organic EL display device. In addition, from the above viewpoint, double-sided pressure-sensitive adhesive sheets (particularly, base-less double-sided pressure-sensitive adhesive sheets) are used as pressure-sensitive adhesive sheets for glass surface sticking. It is preferable.

[Structure]
The structure of the present invention is a structure in which a functional film is attached to a glass surface, and the functional film is attached to the glass surface using the pressure-sensitive adhesive sheet for glass surface application. It is characterized by. Examples of the functional film include an antireflection film and an electromagnetic wave shielding film as described above. A functional film may be used independently and may be used in combination of 2 or more type. Moreover, in this structure, the pressure sensitive adhesive sheets for glass surface sticking may be used independently, and 2 or more types may be used in combination. Specifically, examples of such a structure include various display devices such as a plasma display panel, a liquid crystal display device, and an organic EL display device as described above.

  Examples of the present invention will be described below in more detail. However, the present invention is not limited to these examples.

Example 1
In a reaction vessel equipped with a cooling tube, a nitrogen introducing tube, a thermometer, a dropping funnel, and a stirring device, 2,2′-azobisisobutyronitrile as a polymerization initiator: 0.2 part by weight, and ethyl acetate as a solvent: 150 As parts by weight and monomer components, 85 parts by weight of n-butyl acrylate, 15 parts by weight of N-cyclohexylmaleimide, and 1 part by weight of 2-hydroxyethyl acrylate were added, and nitrogen reflux was performed at room temperature for 1 hour. Thereafter, the temperature of the monomer composition solution containing the monomer component in the reaction vessel was raised to 60 ° C., and polymerization was carried out in a nitrogen stream for 5 hours to obtain an acrylic copolymer solution. In this acrylic copolymer solution, trimethylolpropane / tolylene diisocyanate adduct (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) is used as a crosslinking agent with respect to 100 parts by weight of the acrylic copolymer. 2 parts by weight (solid content) was added to obtain a pressure-sensitive adhesive composition (sometimes referred to as “pressure-sensitive adhesive A”).

  Further, the pressure-sensitive adhesive A was applied onto a release surface of a polyethylene terephthalate film (release liner; thickness 50 μm) that had been subjected to release treatment with a silicone release agent using an applicator, and dried at 130 ° C. for 3 minutes. Thus, an adhesive layer having a thickness of 25 μm was formed. On this pressure-sensitive adhesive layer, a polyethylene terephthalate film (release liner; thickness 38 μm) that had been subjected to a release treatment with a silicone-based release agent was bonded to obtain an adhesive sheet.

(Example 2)
As shown in Table 1, Example 1 except that n-butyl acrylate: 90 parts by weight, N-cyclohexylmaleimide: 10 parts by weight, and 2-hydroxyethyl acrylate: 1 part by weight were used as monomer components. In the same manner, a pressure-sensitive adhesive composition (sometimes referred to as “pressure-sensitive adhesive B”) was prepared. A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that this pressure-sensitive adhesive B was used.

(Comparative Example 1)
As shown in Table 1, a pressure-sensitive adhesive composition (“adhesive”) was used in the same manner as in Example 1 except that n-butyl acrylate: 95 parts by weight and acrylic acid: 5 parts by weight were used as monomer components. (Sometimes referred to as "agent C"). A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that this pressure-sensitive adhesive C was used.

(Comparative Example 2)
As shown in Table 1, Example 1 except that n-butyl acrylate: 80 parts by weight, N-cyclohexylmaleimide: 20 parts by weight, and 2-hydroxyethyl acrylate: 1 part by weight were used as monomer components. In the same manner, a pressure-sensitive adhesive composition (sometimes referred to as “pressure-sensitive adhesive D”) was prepared. A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that this pressure-sensitive adhesive D was used.

(Evaluation)
About the adhesive sheet produced in Examples 1 and 2 and Comparative Examples 1 and 2, the following adhesive strength measurement method, total light transmittance and haze measurement method, color difference measurement method, adhesive strength, adhesive residue prevention, Transparency (total light transmittance, haze, color difference) was evaluated. The evaluation results are shown in Table 1.

(Adhesive strength measurement method)
The release liner on one side of the pressure-sensitive adhesive sheet is peeled off, bonded to a polyethylene terephthalate film (thickness: 125 μm ), cut into a width of 20 mm and a length of 100 mm, and then the release liner on the other side is peeled off to obtain a thickness of 1 It was bonded to a 3 mm glass plate (“Slide glass white edge polish” manufactured by Matsunami Glass Industrial Co., Ltd .; thickness 1.3 mm). Forty-eight hours after attaching to the glass plate, the 90 ° peel adhesive strength was measured. In addition, the measurement conditions of 90 ° peel adhesive strength were peeling angle: 90 °, tensile speed: 300 mm / min, temperature: 23 ° C., humidity: 50% RH, which were bonded to a polyethylene terephthalate film from a glass plate. The 90 ° peel adhesive strength was measured by peeling the adhesive sheet.

Moreover, the glass surface after peeling was observed visually, the presence or absence of the adhesion component remaining on the glass surface (adhesive residue) was confirmed, and the adhesive residue preventing property was evaluated according to the following evaluation criteria.
Evaluation criteria for adhesive residue prevention ○: No adhesive component remains on the glass surface after peeling (no adhesive residue)
X: Adhesive component remains on the glass surface after peeling (with adhesive residue)

(Measurement method of total light transmittance and haze)
Cut the adhesive sheet into 40mm x 40mm, peel off the release liner on one side, and paste it on a slide glass ("Slide glass white edge polish" manufactured by Matsunami Glass Industrial Co., Ltd .; thickness 1.3mm) and heat An evaluation sample for pretreatment for measurement without performing humidification treatment was prepared. Thereafter, the release liner on the other side was removed, and the total light transmittance (% ) And haze (%).

  Also, the adhesive sheet is cut into 40 mm × 40 mm, the release liner on one side is peeled off, and bonded to a slide glass (“Slide glass white edge polish” manufactured by Matsunami Glass Industry Co., Ltd .; thickness 1.3 mm). Then, an evaluation sample for after heating and humidification treatment for measurement after heating and humidification treatment was prepared. After storing the evaluation sample for after heating and humidification treatment in an atmosphere of 60 ° C. × 95% RH for 500 hours, the release liner on the other side of the evaluation sample for after heating and humidification treatment was removed, and a turbidimeter (device name “haze meter”) was used. The total light transmittance (%) and haze (%) were measured according to JIS K7361 and JIS K7136 using HM-150 (Murakami Color Research Laboratory).

  In addition, each evaluation sample of the evaluation sample for pre-treatment and the evaluation sample for post-heat-humidification treatment has a layer configuration of a slide glass / adhesive layer, and the measured total light transmittance (%) and haze (% ) Includes the total light transmittance (%) and haze (%) of the slide glass.

(Measurement method of color difference)
A pre-treatment evaluation sample for measuring the pressure-sensitive adhesive sheet without performing the heating and humidifying treatment was prepared in the same manner as the method for measuring the total light transmittance and haze. Thereafter, the release liner on the other side is removed, and X of the XYZ color system defined in JIS Z8701 is measured using an integrating sphere type spectral transmittance measuring device (device name “DOT-3C” manufactured by Murakami Color Research Laboratory). L ^* , a ^* , b ^* obtained by converting to the CIE L ^* a ^* b ^* color system defined in JIS Z8729 was measured from the values of Y, Z, Y (C light source, 2 ° field of view, wavelength : 390 nm to 730 nm).

Moreover, the evaluation sample for after-heat-humidification processes for measuring after performing a heat-humidification process was produced for the adhesive sheet like the said total light transmittance and the measuring method of haze. After storing the evaluation sample for after heating and humidification treatment for 500 hours in an atmosphere of 60 ° C. × 95% RH, the release liner on the other side of the evaluation sample for after heating and humidification treatment is removed, and the same as the evaluation sample for before treatment. , L ^* , a ^* , b ^* were measured.

From the obtained L ^* , a ^* , and b ^* values, the color difference (ΔE ^* ab) before and after the heat and humidification treatment was calculated using the following equation.
ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2
(Here, [Delta] L ^* is .Δb means the difference between before and after the L ^* values of the heating humidification .Derutaei ^* is that means the difference before and after a ^* values of the heating humidification ^* heating (This means the difference in b ^* values before and after humidification.)

  As is clear from Table 1, the pressure-sensitive adhesive sheets according to Examples 1 and 2 can be easily peeled without causing adhesive residue on the glass surface, and can exhibit appropriate reworkability. It was confirmed that the optical characteristics were good. In contrast, the pressure-sensitive adhesive sheets according to Comparative Examples 1 and 2 have no adhesive residue on the glass surface, strong adhesive strength, and no appropriate rework properties, so that satisfactory results are not obtained.

Claims (4)

A pressure-sensitive adhesive tape or sheet for directly attaching to a glass surface, wherein the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive tape or sheet comprises the following component (a) with respect to the total amount of monomer components: 84 -94.6% by weight, the following component (b) is included in a proportion of 5 to 15.6% by weight based on the total amount of the monomer components, and the following component (c ′) A single amount which is contained in a proportion of 0.2 to 5% by weight with respect to the total amount of the body component and whose content of the carboxyl group-containing copolymerizable monomer is 2% by weight or less with respect to the total amount of the monomer component The adhesive strength of the pressure-sensitive adhesive layer is 1 to 7 (N / 20 mm) (to glass plate, temperature: 23 ° C., humidity: 50% RH, peeling angle: 90 °, tensile speed: 300 mm / min; thickness 125 μm A pressure-sensitive adhesive tape or sheet bonded to a polyethylene terephthalate film is attached to a glass plate having a thickness of 1.3 mm and then peeled off from the glass plate). Adhesive tape or sheet.
(A) Component: Acrylic monomer represented by the following formula (1) CH ₂ = C (R ¹ ) COOR ² (1)
(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an s-butyl group, a t-butyl group, a pentyl group, an isoamyl group, Group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group or isodecyl group .)
(B) Component: Maleimide compound represented by the following formula (2)

(In the formula (2), R ³ is a hydrocarbon group selected from an alkyl group having 1 to 14 carbon atoms, a cycloalkyl group having 3 to 12 members, a phenyl group, a naphthyl group, a benzyl group and a 2-phenylethyl group. (However, the said hydrocarbon group may have a substituent selected from a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, and a nitro group) .
Component (c ′): does not contain a carboxyl group, and can be copolymerized with component (a) and component (b), (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2- A hydroxyl group-containing copolymerizable monomer selected from hydroxypropyl, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, an epoxy group-containing copolymer selected from glycidyl (meth) acrylate Another monomer that is at least one monomer selected from a polymerizable monomer, a vinyl ester copolymerizable monomer selected from vinyl acetate and vinyl propionate The pressure-sensitive adhesive layer has a total light transmittance of 85% or more after heating and humidifying treatment at 60 ° C. and 95% RH for 500 hours, and haze is 10% or less after the heating and humidifying treatment. Furthermore, the pressure-sensitive adhesive tape or sheet for glass surface sticking of Claim 1 whose color difference ((DELTA) E ^* ab) before and behind the said heating and humidification process is 0.5 or less.   It is a structure in which a functional film is affixed to the glass surface, and the functional film is affixed to the glass surface using the pressure-sensitive adhesive tape or sheet for affixing a glass surface according to claim 1 or 2. A structure characterized by   The structure according to claim 3, wherein the structure is any one of a plasma display panel, a liquid crystal display device, and an organic EL display device.