JP5332315B2 - Optical laminate - Google Patents

Abstract

Disclosed is a resin film with adhesive, which is obtained by forming an adhesive layer on the surface of a resin film. The adhesive layer is excellent in durability and provided with high antistatic properties which hardly change over time. Specifically disclosed is a resin film with adhesive, which is obtained by forming an adhesive layer on at least one side of a resin film such as an optical film or a surface protection film. The adhesive layer is made from a composition containing 0.2-8 parts by weight of an ionic compound (B) having an organic cation, which is in a solid state at room temperature, per 100 parts by weight of an acrylic resin (A) mainly composed of a structural unit derived from a (meth)acrylate represented by the following formula (I). In the formula (I), R1 represents a hydrogen atom or a methyl group; and R2 represents an alkyl or aralkyl group having 1-14 carbon atoms which may be substituted by an alkoxy group having 1-10 carbon atoms.

Description

The present invention relates to an optical laminate for liquid crystal display using an optical film having an adhesive layer formed thereon. The optical film targeted by the present invention includes a polarizing film and / or a retardation film . The present specification also discloses a surface protective film that is bonded to a surface opposite to the pressure-sensitive adhesive layer of an optical film including a polarizing film and / or a retardation film and protects the surface until use .

  A polarizing film is mounted on a liquid crystal display device and is widely used. A transparent protective film is laminated on both sides of a polarizer, and an adhesive layer is formed on the surface of at least one protective film. It is distributed in the state where the release film is stuck to. Moreover, a retardation film is laminated on a polarizing film in which a protective film is bonded on both sides of the polarizer to form an elliptically polarizing film, and an adhesive layer / release film is stuck in this order on the retardation film side. Sometimes. Furthermore, an adhesive layer / release film may be stuck in this order on the surface of the retardation film. Prior to bonding to the liquid crystal cell, the release film is peeled off from these polarizing film, elliptical polarizing film, retardation film, etc., and bonded to the liquid crystal cell via the exposed adhesive layer. Such a polarizing film, an elliptically polarizing film, or a retardation film generates static electricity when the release film is peeled off and bonded to a liquid crystal cell.

  As one of the countermeasures, in Japanese Patent No. 3012860 (Patent Document 1), in a polarizing film in which a protective film is laminated on the surface of a polarizer film and an adhesive layer is provided on the surface of the protective film, It has been proposed to use an ion conductive composition composed of an electrolyte salt and an organopolysiloxane and a composition containing an acrylic copolymer. By using such a pressure-sensitive adhesive, although antistatic properties are exhibited, its performance is not necessarily sufficient, and it cannot be said that adhesion durability is sufficient.

Therefore, Japanese Patent Publication No. 2004-536940 (Patent Document 2) discloses that an organic salt-based antistatic agent is blended with a pressure-sensitive adhesive (adhesive) to impart antistatic properties to the adhesive. It is disclosed.
JP-A-2004-114665 (Patent Document 3) includes a salt composed of a quaternary ammonium cation having a total carbon number of 4 to 20 and a fluorine atom-containing anion in an adhesive, etc. It is described to give. Furthermore, JP 2006-307238 A (Patent Document 4) describes that an adhesive contains an ionic liquid that becomes liquid at room temperature (25 ° C.) to prevent charging. However, when the polarizing film coated with the adhesive is left for a long time, the antistatic property is still deteriorated due to a change with time. Since the distribution and storage period of a general polarizing film is about 6 months at the maximum from production, it is required to maintain antistatic performance until the customer uses it.

  Moreover, the optical film with an adhesive as described above is bonded to a liquid crystal cell on the adhesive layer side to form a liquid crystal display device. In this state, the optical film is placed under high temperature or high temperature and high humidity conditions, or heated. When cooling is repeated, foaming occurs in the pressure-sensitive adhesive layer with the dimensional change of the optical film, or floats or peels between the optical film and the pressure-sensitive adhesive layer, or between the pressure-sensitive adhesive layer and the liquid crystal cell glass. Therefore, it is also required to have excellent durability without causing such problems. In addition, when exposed to high temperatures, the distribution of residual stress acting on the optical film becomes non-uniform and stress concentration occurs on the outer periphery of the optical film, resulting in a phenomenon called whitening that causes the outer periphery to become whitish when displaying black. In some cases, color unevenness may occur, and suppression of such white spots and color unevenness is also required. Furthermore, when there is a deficiency when bonding an optical film with an adhesive to a liquid crystal cell, the optical film will be peeled off once and then a new film will be pasted again. A so-called rework property is also required in which the pressure-sensitive adhesive layer is peeled off along with the optical film, and the pressure-sensitive adhesive does not remain on the cell glass and no fogging occurs.

  On the other hand, a surface protective film is generally bonded to an optical film that is a protected body through an adhesive formed on one side thereof, and is used to prevent scratches or dirt generated during processing or transportation of the protected body. It is done. For example, an optical film such as a polarizing film or a retardation film for application to a liquid crystal display device is on the side opposite to the adhesive layer for bonding to the liquid crystal cell described above for the purpose of preventing scratches and dirt. The surface protective film is distributed in a state where the surface protective film is bonded to the surface. This surface protective film is peeled and removed after the optical film is bonded to the liquid crystal cell. When the surface film is peeled off, static electricity is generated, and when a voltage is applied to the liquid crystal cell with the static electricity remaining, the liquid crystal molecules The surface protective film is subjected to various antistatic treatments because of the problem that the orientation of the film is impaired or the panel is damaged.

Japanese Patent No. 3012860 (= Japanese Patent Laid-Open No. 6-313807) Japanese translation of PCT publication No. 2004-536940 (= WO 2003/011958) JP 2004-114665 A JP 2006-307238 A

An object of the present invention, with a high antistatic property is imparted, its antistatic property hardly varies with time, the optical film pressure-sensitive adhesive provided on the surface of the optical film pressure-sensitive adhesive layer excellent in durability, An object of the present invention is to provide an optical laminate for liquid crystal display which is laminated on a glass substrate on the pressure-sensitive adhesive layer side . As a result of diligent research to solve such problems, the present inventors formulated a specific ionic compound that becomes a solid at room temperature (25 ° C.) into an adhesive mainly composed of an acrylic resin. by providing the composition as an adhesive layer on the surface of the optical film, antistatic, optical film with excellent adhesive to aging and durability of antistatic property found that is obtained, reaching the present invention did.

That is, according to the present invention, with adhesive resin film ing adhesive layer is formed on one surface of the optical film, it is laminated to the glass substrate at the adhesive layer side, the adhesive layer, There is provided an optical laminate formed from a composition containing the following components (A) , (B) , (C) and (D) .

（式中、Ｒ₁は水素原子又はメチル基を表し、Ｒ₂は、それぞれ炭素数１〜１０のアルコキシ基で置換されていてもよい炭素数１〜１４のアルキル基又はアラルキル基を表す）
で示される（メタ）アクリル酸エステルに由来する構造単位を主成分とし、極性官能基を有するモノマーに由来する構造単位を含むアクリル樹脂１００重量部、
（Ｂ）ピリジニウムカチオン及びイミダゾリウムカチオンから選ばれる有機カチオンを有し、室温において固体であるイオン性化合物 ０.２〜８重量部、
（Ｃ）架橋剤 ０.０１〜１０重量部、及び
（Ｄ）シラン系化合物 ０.０１〜１０重量部。 (A) The following formula (I)

(In the formula, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a C 1-14 alkyl group or an aralkyl group, each of which may be substituted with a C 1-10 alkoxy group)
100 parts by weight of an acrylic resin containing a structural unit derived from a monomer having a polar functional group, the structural unit derived from a (meth) acrylic acid ester represented by
(B) 0.2 to 8 parts by weight of an ionic compound having an organic cation selected from a pyridinium cation and an imidazolium cation and being solid at room temperature ,
(C) 0.01 to 10 parts by weight of a crosslinking agent, and
(D) Silane compound 0.01 to 10 parts by weight .

  As described above, in the present invention, the acrylic resin (A) constituting the pressure-sensitive adhesive imparts antistatic properties to the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive, and suppresses the change in antistatic properties over time. As an antistatic agent, it has been found that an ionic compound (B) which is solid at room temperature (25 ° C.) is particularly effective.

Optical film for forming such a pressure-sensitive adhesive layer, a polarizing film and / or including a retardation film.

In the present invention, the following adhesive optical film with the above, laminated to a glass substrate at the adhesive layer side, shall be the optical laminate for liquid crystal display.

The optical laminate of the present invention, that Do is assumed that a static-is effectively suppressed. Further, the optical film with an adhesive used for this purpose can maintain the initial antistatic performance even after being manufactured and stored for a long time.

The optical film with the adhesive, by laminating the glass substrate of the liquid crystal cell, providing an optical laminate for a liquid crystal display. In this optical laminate, the pressure-sensitive adhesive layer absorbs and relaxes stress caused by dimensional changes of the optical film and the glass substrate under wet heat conditions, so that local stress concentration is reduced and the pressure-sensitive adhesive layer floats on the glass substrate. And peeling are suppressed. In addition, since optical defects due to non-uniform stress distribution are prevented, white spots are suppressed. In addition, if there is any inconvenience after laminating the optical film with adhesive once on the glass substrate, even if the optical film is peeled off from the glass substrate together with the adhesive, adhesive residue or Clouding is less likely to occur, and it can be used again as a glass substrate, resulting in excellent reworkability.

The resin film with the pressure-sensitive adhesive provided with the above pressure-sensitive adhesive layer on the resin film can be bonded to the surface of the optical film and used as a surface protective film that protects the surface until use. Also in this case, it gives an excellent antistatic effect, for example, occurs when the surface protective film is peeled off after the optical film is bonded to the liquid crystal cell via the pressure-sensitive adhesive layer opposite to the surface protective film. Static electricity can be reduced.

Hereinafter, the present invention will be described in detail. The optical film pressure-sensitive adhesive used in the present invention, Ru der those pressure-sensitive adhesive layer is formed on one surface of the optical film. The adhesive layer is
(A) acrylic resin ,
(B) an ionic compound having an organic cation selected from a pyridinium cation and an imidazolium cation, and being solid at room temperature ,
(C) a crosslinking agent, and
(D) It is formed from a composition containing a silane compound . First, each component which comprises an adhesive composition is demonstrated.

[Acrylic resin (A)]
Acrylic resin used in the pressure-sensitive adhesive layer (A), the formula (I) represented by (meth) as a main component a structural unit derived from an acrylic acid ester, specifically, such ( In addition to structural units derived from (meth) acrylic acid esters, monomers having polar functional groups such as free carboxyl groups, hydroxyl groups, amino groups, and heterocyclic groups such as epoxy rings, preferably having polar functional groups (meth) Ru der those comprising structural units derived from acrylic acid-based compound. Here, (meth) acrylic acid means that either acrylic acid or methacrylic acid may be used, and “(meth)” in the case of (meth) acrylate or the like has the same meaning.

In the formula (I), which is the main structural unit of the acrylic resin (A), R ₁ is a hydrogen atom or a methyl group, and R ₂ is an alkyl group or aralkyl group having 1 to 14 carbon atoms, preferably an alkyl group. is there. In the alkyl group or aralkyl group represented by R ₂ , a hydrogen atom in each group may be substituted with an alkoxy group having 1 to 10 carbon atoms.

  Specific examples of the (meth) acrylic acid ester represented by the formula (I) include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, and lauryl acrylate, Linear alkyl acrylate ester; branched alkyl acrylate ester such as isobutyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-methacrylate Examples include linear alkyl methacrylates such as butyl, n-octyl methacrylate and lauryl methacrylate; branched alkyl esters such as isobutyl methacrylate, 2-ethylhexyl methacrylate and isooctyl methacrylate. Is done.

When R ₂ is an alkyl group substituted with an alkoxy group, that is, when R ₂ is an alkoxyalkyl group, the (meth) acrylic acid ester represented by the formula (I) is specifically acrylic acid. Examples include 2-methoxyethyl, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, ethoxymethyl methacrylate, and the like. Specific examples of the (meth) acrylic acid ester represented by the formula (I) when R ₂ is an aralkyl group include benzyl acrylate and benzyl methacrylate.

  These (meth) acrylic acid esters can be used alone or in combination with a plurality of different ones.

  Examples of the monomer having a polar functional group include monomers having a free carboxyl group such as acrylic acid, methacrylic acid, and β-carboxyethyl acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxy (meth) acrylate Monomers having a hydroxyl group such as propyl, 2- or 3-chloro-2-hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate; acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl Has a heterocyclic group such as (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, 2,5-dihydrofuran And a monomer having an amino group different from the heterocyclic ring, such as N, N-dimethylaminoethyl (meth) acrylate. These monomers having a polar functional group may be used singly or a plurality of different monomers may be used.

  Among these, it is preferable to use a monomer having a hydroxyl group as one of polar functional group-containing monomers constituting the acrylic resin (A). In addition to the monomer having a hydroxyl group, it is also effective to use a monomer having another polar functional group, for example, a monomer having a free carboxyl group.

  The acrylic resin (A) used for the pressure-sensitive adhesive layer is a structural unit derived from the (meth) acrylic acid ester represented by the formula (I), usually 60 to 99. 9 parts by weight, preferably 80 to 99.6 parts by weight, and the structural unit derived from the monomer having a polar functional group is usually 0.1 to 20 parts by weight, preferably 0.4. -10 parts by weight.

  The acrylic resin (A) used in the present invention may contain a structural unit derived from a monomer other than the (meth) acrylic acid ester of the formula (I) described above and a monomer having a polar functional group. Examples of these include structural units derived from (meth) acrylic acid esters having an alicyclic structure in the molecule, structural units derived from styrene monomers, structural units derived from vinyl monomers, and a plurality of structural units in the molecule. Examples include structural units derived from monomers having a (meth) acryloyl group.

  The alicyclic structure is a cycloparaffin structure having usually 5 or more carbon atoms, preferably about 5 to 7 carbon atoms. Specific examples of the acrylate ester having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methyl cyclohexyl acrylate, trimethyl cyclohexyl acrylate, tert-butyl acrylate Examples of methacrylic acid esters having an alicyclic structure include cyclohexyl, α-ethoxyacrylic acid cyclohexyl, cyclohexyl phenyl acrylate, etc. Specific examples of methacrylic acid esters having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, Such as cyclododecyl, methyl cyclohexyl methacrylate, trimethyl cyclohexyl methacrylate, tert-butyl cyclohexyl methacrylate, cyclohexyl phenyl methacrylate And so on.

  Examples of styrenic monomers include styrene, alkyl styrene such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, octyl styrene; Halogenated styrene such as styrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene; and nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene and the like.

  Examples of vinyl-based monomers include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate such as vinyl esters; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride and the like. Examples thereof include vinylidene halides; nitrogen-containing aromatic vinyls such as vinyl pyridine, vinyl pyrrolidone and vinyl carbazole; conjugated diene monomers such as butadiene, isoprene and chloroprene; and acrylonitrile and methacrylonitrile.

  Examples of monomers having a plurality of (meth) acryloyl groups in the molecule include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di ( 2 (meth) acryloyl groups in the molecule such as (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate And a monomer having three (meth) acryloyl groups in the molecule, such as trimethylolpropane tri (meth) acrylate.

  Monomers other than the (meth) acrylic acid ester of formula (I) and the monomer having a polar functional group can be used alone or in combination of two or more. In the acrylic resin (A) used for the pressure-sensitive adhesive, the structural unit derived from a monomer other than the (meth) acrylic acid ester of formula (I) and the monomer having a polar functional group is contained in 100 parts by weight of the non-volatile content of the resin. On the other hand, it is contained in an amount of usually 0 to 20 parts by weight, preferably 0 to 10 parts by weight.

  The active ingredient of the pressure-sensitive adhesive is an acrylic resin containing a structural unit derived from a monomer having a polar functional group, the main component of which is the structural unit derived from the (meth) acrylic acid ester represented by the formula (I). 2 or more types may be included. Further, the acrylic resin is mixed with an acrylic resin different from the acrylic resin, specifically, for example, an acrylic resin having a structural unit derived from the (meth) acrylic ester of the formula (I) and containing no polar functional group. It may be what you did. The acrylic resin containing a structural unit derived from a monomer having a polar functional group, the main component of which is a structural unit derived from the (meth) acrylic acid ester of the formula (I) is 60% by weight or more of the total acrylic resin, Is preferably 80% by weight or more.

  An acrylic resin containing a structural unit derived from a monomer having a polar functional group, the main component of which is a structural unit derived from the (meth) acrylic acid ester of formula (I), is a standard by gel permeation chromatography (GPC). The polystyrene equivalent weight average molecular weight (Mw) is preferably in the range of 1,000,000 to 2,000,000. If the weight average molecular weight in terms of standard polystyrene is 1,000,000 or more, the adhesiveness at high temperature and high humidity will improve, and the possibility of floating or peeling between the glass substrate and the adhesive layer will tend to decrease. In addition, it is preferable because reworkability tends to be improved. In addition, when the weight average molecular weight is 2,000,000 or less, even if the dimension of the optical film bonded to the pressure-sensitive adhesive layer changes, the pressure-sensitive adhesive layer changes following the dimensional change. This is preferable because there is no difference between the brightness of the peripheral portion and the brightness of the central portion, and white spots and color unevenness tend to be suppressed. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually in the range of about 2 to 10.

  This acrylic resin can be composed only of a relatively high molecular weight as described above, or can be composed of a mixture of an acrylic resin different from the acrylic resin in addition to the acrylic resin. Examples of the acrylic resin that can be used as a mixture include those having a structural unit derived from the (meth) acrylic acid ester represented by the formula (I) as a main component and having a weight average molecular weight in the range of 50,000 to 300,000. be able to.

  Acrylic resin (a mixture of both when two or more types are combined) is a solution prepared by dissolving it in ethyl acetate to a non-volatile content concentration of 20% by weight at 25 ° C., 20 Pa · s or less, and further 0.1-7 Pa. -It is preferable to show the viscosity of s. If the viscosity at this time is 20 Pa · s or less, the adhesiveness under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate and the pressure-sensitive adhesive layer tends to be reduced. Moreover, it is preferable because reworkability tends to be improved. Viscosity can be measured with a Brookfield viscometer.

  The acrylic resin constituting the pressure-sensitive adhesive layer can be produced by various known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. In the production of this acrylic resin, a polymerization initiator is usually used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by weight with respect to a total of 100 parts by weight of all monomers used in the production of the acrylic resin.

  As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like is used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone. Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis (2-methylpropio) Azo) compounds such as 2,2'-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide , Diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, tert-butyl peroxy Organic peroxides such as neodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate and hydrogen peroxide Can do. A redox initiator using a peroxide and a reducing agent in combination can also be used as the polymerization initiator.

As a method for producing the acrylic resin, the solution polymerization method is preferable among the methods shown above.
A specific example of the solution polymerization method will be described. A desired monomer and an organic solvent are mixed, and a thermal polymerization initiator is added under a nitrogen atmosphere, and is about 40 to 90 ° C, preferably about 60 to 80 ° C. And a method of stirring for about 3 to 10 hours. Moreover, in order to control reaction, you may add a monomer and a thermal-polymerization initiator continuously or intermittently during superposition | polymerization, or may be added in the state melt | dissolved in the organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ketones such as can be used.

[Ionic compound (B)]
In the present invention, in addition to the acrylic resin (A) as described above, an ionic compound (B) that is solid at room temperature (25 ° C.) is used as an antistatic agent. This ionic compound (B) has an organic cation. Such ionic compounds that are solid at room temperature may be referred to herein as ionic solids.

Cation components constituting the ionic compound (B), I organic cation der satisfies that it becomes an ionic solid, for example, imidazolium cation, pyridinium cation, an ammonium cation, sulfonium cation, a phosphonium cation Oh that is, when it is used in the pressure-sensitive adhesive layer of the optical film, from the viewpoint that it is difficult to charge when peeling off the release film provided thereon, used as organic cation is a pyridinium cation or an imidazolium cation in the present invention .

  On the other hand, in the ionic compound (B), the anion component serving as the counter ion of the cation component is not particularly limited as long as it satisfies that it becomes an ionic solid, and may be an inorganic anion, Organic anions may be used, and examples include the following.

Chloride anion [Cl ⁻ ],
Bromide anion [Br ⁻ ],
Iodide anion [I ⁻ ],
Tetrachloroaluminate anion [AlCl ₄ ⁻ ],
Heptachlorodialuminate anion [Al ₂ Cl ₇ ⁻ ],
Tetrafluoroborate anion [BF ₄ ⁻ ],
Hexafluorophosphate anion [PF ₆ ⁻ ],
Perchlorate anion [ClO ₄ ⁻ ],
Nitrate anion [NO ₃ ⁻ ],
Acetate anion [CH ₃ COO ⁻ ],
Trifluoroacetate anion [CF ₃ COO ⁻ ],
Methanesulfonate anion [CH ₃ SO ₃ ⁻ ],
Trifluoromethanesulfonate anion [CF ₃ SO ₃ ⁻ ],
p-toluenesulfonate anion [p-CH ₃ C ₆ H ₄ SO ₃ ⁻ ],
Bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ],
Tris (trifluoromethanesulfonyl) methanide anion [(CF ₃ SO ₂ ) ₃ C ⁻ ], hexafluoroarsenate anion [AsF ₆ ⁻ ],
Hexafluoroantimonate anion [SbF ₆ ⁻ ],
Hexafluoroniobate anion [NbF ₆ ⁻ ],
Hexafluorotantalate anion [TaF ₆ ⁻ ],
Dimethyl phosphinate anion [(CH ₃ ) ₂ POO ⁻ ],
(Poly) hydrofluorofluoride anion [F (HF) _n ⁻ ] (n is about 1 to 3), dicyanamide anion [(CN) ₂ N ⁻ ],
Thiocyan anion [SCN ⁻ ],
Perfluorobutanesulfonate anion [C ₄ F ₉ SO ₃ ⁻ ],
Bis (pentafluoroethanesulfonyl) imide anion [(C ₂ F ₅ SO ₂ ) ₂ N ⁻ ], perfluorobutanoate anion [C ₃ F ₇ COO ⁻ ],
(Trifluoromethanesulfonyl) (trifluoromethanecarbonyl) imide anion [(CF ₃ SO ₂ ) (CF ₃ CO) N ⁻ ] and the like.

  Among these, in particular, an anion component containing a fluorine atom is preferably used because it gives an ionic solid excellent in antistatic performance, and a hexafluorophosphate anion is particularly preferable.

Specific examples of the ion-solid can be appropriately selected from a combination of the aforementioned cation component and anion component. Specific examples of the compound that is a combination of a cation component and an anion component include the following.

N-hexylpyridinium hexafluorophosphate,
N-octylpyridinium hexafluorophosphate,
N-butyl-4-methylrupyridinium hexafluorophosphate,
N-butyl-N-methylpyrrolidinium hexafluorophosphate,
1-ethyl-3-methylimidazolium hexafluorophosphate,
1-ethyl-3-methylimidazolium p-toluenesulfonate,
Etc. 1-butyl-3-a-methylimidazolium methanesulfonate Natick bets.

  Such ionic solids can be used alone or in combination of two or more. Examples of ionic solids are not limited to the materials listed above.

  As described above, the ionic compound (B) that is solid at room temperature imparts antistatic properties to the pressure-sensitive adhesive layer formed from the composition containing the acrylic resin (A) and maintains various physical properties as a pressure-sensitive adhesive. It is effective in. In particular, compared with the case of using an ionic compound that is liquid at room temperature, the antistatic performance can be maintained for a long period of time. From the viewpoint of such antistatic long-term stability, the ionic compound (B) preferably has a melting point of 30 ° C. or higher, more preferably 35 ° C. or higher. On the other hand, when the melting point is too high, the compatibility with the acrylic resin (A) is deteriorated, so that it preferably has a melting point of 90 ° C. or lower, more preferably 80 ° C. or lower.

  The ionic compound (B) is contained in a proportion of 0.2 to 8 parts by weight with respect to 100 parts by weight of the nonvolatile content of the acrylic resin (A) (the total weight when two or more kinds are used). When the ionic compound (B) is contained in an amount of 0.2 part by weight or more with respect to 100 parts by weight of the nonvolatile content of the acrylic resin (A), the antistatic performance is improved, and the amount is preferably 8 parts by weight or less. It is preferable because durability is easy to maintain. The amount of the ionic compound (B) with respect to 100 parts by weight of the non-volatile content of the acrylic resin (A) can be in the range of 0.2 to 5 parts by weight, preferably 0.5 parts by weight or more, and 3 parts by weight. It is as follows.

[ Crosslinking agent ]
The above acrylic resin (A) and ionic compounds such as (B), to be et al, blended cross-linking agent (C) and the silane compound (D), the pressure-sensitive adhesive composition. The crosslinking agent (C) is a compound having in the molecule at least two functional groups capable of crosslinking with a structural unit derived from the polar functional group-containing monomer in the acrylic resin (A), specifically, Illustrative examples include isocyanate compounds, epoxy compounds, metal chelate compounds, and aziridine compounds.

  Isocyanate compounds are compounds having at least two isocyanato groups (-NCO) in the molecule, such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, Examples thereof include hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. In addition, adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and those obtained by converting isocyanate compounds into dimers, trimers, and the like can also be used as crosslinking agents for pressure-sensitive adhesives. Two or more isocyanate compounds can be mixed and used.

  The epoxy compound is a compound having at least two epoxy groups in the molecule, for example, bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether. 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N, N-diglycidylaniline, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis ( N, N'-diglycidylaminomethyl) cyclohexane and the like. Two or more types of epoxy compounds can be mixed and used.

  Examples of the metal chelate compound include compounds in which acetylacetone or ethyl acetoacetate is coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. Can be mentioned.

  An aziridine-based compound is a compound having at least two skeletons of a three-membered ring composed of one nitrogen atom and two carbon atoms, also called ethyleneimine, for example, diphenylmethane-4,4′-bis ( 1-aziridinecarboxamide), toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1- (2-methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene Examples include -1,6-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and the like.

  Among these crosslinking agents, isocyanate compounds, particularly xylylene diisocyanate, tolylene diisocyanate or hexamethylene diisocyanate, or adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and isocyanate compounds A dimer, a trimer or the like, a mixture of these isocyanate compounds, or the like is preferably used. Examples of suitable isocyanate compounds include tolylene diisocyanate, adducts obtained by reacting tolylene diisocyanate with polyols, tolylene diisocyanate dimers, and tolylene diisocyanate trimers, hexamethylene diisocyanate, and hexamethylene diisocyanate. Examples include adducts reacted with polyols, dimers of hexamethylene diisocyanate, and trimers of hexamethylene diisocyanate.

Crosslinking agent (C), relative to the acrylic resin (A) 100 parts by weight of (total weight thereof in the case of using two or more), but is blended in an amount of 0.01 to 10 parts by weight, preferably 0.1 It mix | blends in the ratio of about 5 weight part. The amount of the crosslinking agent (C) relative to 100 parts by weight of the acrylic resin (A) is preferably 0.01 parts by weight or more because the durability of the pressure-sensitive adhesive layer tends to be improved, and is preferably 10 parts by weight or less. And, when the optical film with a pressure-sensitive adhesive is applied to a liquid crystal display device, white spots are not noticeable.

[Silane compounds]
The silane compound (D) is used for improving the adhesion between the pressure-sensitive adhesive layer and the glass substrate . Silane compound, it is preferably allowed to containing chromatic before acrylic resin to a crosslinking agent.

  Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Methoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane , 3-glycidoxypropyl triethoxysilane, 3-glycidoxypropyl dimethoxymethyl silane, such as 3-glycidoxypropyl ethoxy dimethyl silane. Two or more silane compounds may be used.

  The silane compound may be of a silicone oligomer type. When the silicone oligomer is shown in the form of (monomer) oligomer, for example, the following can be mentioned.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer,
3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer,
3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer,
A copolymer containing mercaptopropyl groups, such as a 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer;

Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer,
Mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer,
Mercaptomethyltriethoxysilane-tetramethoxysilane copolymer,
A copolymer containing a mercaptomethyl group, such as a mercaptomethyltriethoxysilane-tetraethoxysilane copolymer;

3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer,
3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer,
3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer,
3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer,
3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,
Copolymers containing methacryloyloxypropyl groups, such as 3-methacryloxyyl propylmethyldiethoxysilane-tetraethoxysilane copolymer;

3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer,
3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer,
3-acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer,
3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer,
3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,
A copolymer containing acryloyloxypropyl groups, such as 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;

Vinyltrimethoxysilane-tetramethoxysilane copolymer,
Vinyltrimethoxysilane-tetraethoxysilane copolymer,
Vinyltriethoxysilane-tetramethoxysilane copolymer,
Vinyltriethoxysilane-tetraethoxysilane copolymer,
Vinylmethyldimethoxysilane-tetramethoxysilane copolymer,
Vinylmethyldimethoxysilane-tetraethoxysilane copolymer,
Vinylmethyldiethoxysilane-tetramethoxysilane copolymer,
A vinyl group-containing copolymer, such as vinylmethyldiethoxysilane-tetraethoxysilane copolymer;

3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer,
3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer,
3-aminopropyltriethoxysilane-tetramethoxysilane copolymer,
3-aminopropyltriethoxysilane-tetraethoxysilane copolymer,
3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer,
Amino group-containing copolymers such as 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

These silane-based compounds are often liquids. The amount of the silane compound in the adhesive is a non-volatile content 100 parts by weight of the acrylic resin (A) with respect to (the total weight in the case of using two or more) are used in an amount of 0.01 to 10 parts by weight Is preferably used in a proportion of 0.05 to 5 parts by weight. When the amount of the silane compound relative to 100 parts by weight of the acrylic resin is 0.01 parts by weight or more, the adhesiveness between the pressure-sensitive adhesive layer and the glass substrate is improved. Moreover, it is preferable for the amount to be 10 parts by weight or less because the silane compound tends to be suppressed from bleeding out from the pressure-sensitive adhesive layer.

[Other components constituting the adhesive]
The pressure-sensitive adhesive described above may further contain a crosslinking catalyst, a weather resistance stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a resin other than the acrylic resin (A), and the like. It is also useful to blend a UV curable compound with the pressure-sensitive adhesive and to cure it by irradiating it with ultraviolet light after forming the pressure-sensitive adhesive layer to form a harder pressure-sensitive adhesive layer. Above all, if a crosslinking catalyst with the crosslinking agent in the pressure-sensitive adhesive, it is possible to prepare a pressure-sensitive adhesive layer in a short time aging, the optical film pressure-sensitive adhesive obtained, float between the optical film and the pressure-sensitive adhesive layer Occurrence of peeling or peeling or foaming in the pressure-sensitive adhesive layer can be suppressed, and reworkability can be further improved. Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin, and melamine resin. When an amine compound is added to the adhesive as a crosslinking catalyst, an isocyanate compound is suitable as the crosslinking agent.

  Each of these components constituting the pressure-sensitive adhesive is made into a pressure-sensitive adhesive composition in a state dissolved in a solvent, and is applied onto a suitable substrate and dried to form a pressure-sensitive adhesive layer.

In the optical film with viscosity adhesives, pressure-sensitive adhesive layer, it is preferred that the gel fraction is set to be in the range of 50 to 99 wt%. Here, the gel fraction is a value measured according to the following (I) to (IV).

(I) An adhesive layer having an area of about 8 cm × about 8 cm and a metal mesh made of SUS304 (with a weight of Wm) of about 10 cm × about 10 cm are bonded together.
(II) Weigh the bonded product obtained in (I) above, weigh it Ws, then fold it 4 times so as to wrap the adhesive layer and weigh it with a stapler (stapler). The weight is Wb.
(III) The mesh stapled in (II) above is placed in a glass container, and 60 ml of ethyl acetate is added and immersed, and then the glass container is stored at room temperature for 3 days.
(IV) The mesh is taken out from the glass container, dried at 120 ° C. for 24 hours, weighed, the weight is taken as Wa, and the gel fraction is calculated based on the following formula.

    Gel fraction (% by weight) = [{Wa− (Wb−Ws) −Wm} / (Ws−Wm)] × 100

  When the gel fraction of the pressure-sensitive adhesive layer is 50% by weight or more, the durability of the pressure-sensitive adhesive layer tends to improve, and when the gel fraction is 99% by weight or less, it is easy to manufacture. To preferred.

  In order to adjust the gel fraction of the pressure-sensitive adhesive layer to 50 to 99% by weight, it depends on the type of acrylic resin that is the active ingredient of the pressure-sensitive adhesive layer. Therefore, the gel fraction may be adjusted by the amount of the crosslinking agent. Specifically, the blending amount of the crosslinking agent with respect to 100 parts by weight of the non-volatile content of the acrylic resin constituting the pressure-sensitive adhesive layer (the total amount when two or more types are used) is in the range of about 0.01 to 10 parts by weight. What is necessary is just to select suitably according to the kind of acrylic resin. The gel fraction of the pressure-sensitive adhesive layer is more preferably 65% by weight or more, further 75% by weight or more, and 95% by weight or less.

[Resin film with adhesive]
On the front surface of dendritic fat film, provided with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition as described above, Ru is an adhesive with a resin film. Tree fat film, as long as an optical film comprising a film selected from the polarizing film and phase difference film, the optical film pressure-sensitive adhesive used in the present invention. On the other hand, the resin film with the adhesive is bonded to such an optical film is a object to be protected, ing also the surface protective film to be used for the purpose of protecting the surface from scratches and dirt.

  A polarizing film is an optical film having a function of emitting polarized light with respect to incident light such as natural light. The polarizing film absorbs linearly polarized light having a vibration surface in a certain direction and reflects linearly polarized film having a property of transmitting linearly polarized light having a vibration surface orthogonal to the vibration surface, and reflects linearly polarized light having a vibration surface in a certain direction, There are a polarizing separation film having a property of transmitting linearly polarized light having a vibration plane orthogonal to the polarizing film, an elliptically polarizing film in which a polarizing film and a retardation film described later are laminated. As a suitable specific example of a polarizing film, particularly a linear polarizing film (sometimes called a polarizer or a polarizer film), a dichroic dye such as iodine or a dichroic dye is added to a uniaxially stretched polyvinyl alcohol resin film. Are adsorbed and oriented.

  The retardation film is an optical film exhibiting optical anisotropy, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, cyclic polyolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride. / Stretched film obtained by stretching polymer film made of polymethyl methacrylate, liquid crystal polyester, acetyl cellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc. by about 1.0 to 6 times It is done. Among them, a polymer film obtained by uniaxially or biaxially stretching a polycarbonate film or a cyclic polyolefin film is preferable. Although there exist what is called a uniaxial phase difference film, a wide viewing angle phase difference film, a low photoelasticity phase difference film, etc., it is applicable to all.

  Moreover, the film which expressed optical anisotropy by application | coating and orientation of a liquid crystalline compound, and the film which expressed optical anisotropy by application | coating of an inorganic layered compound can also be used as retardation film. Such retardation films include what are called temperature-compensated retardation films, and films with a twisted orientation of rod-like liquid crystals sold under the trade name “LC film” by Nippon Oil Corporation. Also, a film with a tilted orientation of a rod-shaped liquid crystal sold under the trade name “NH film” by Nippon Oil Corporation, and a disk-shaped liquid crystal sold under the trade name “WV film” by FUJIFILM Corporation. Is a film with a tilt orientation, a fully biaxially oriented film sold under the trade name “VAC film” by Sumitomo Chemical Co., Ltd., and also sold under the trade name “new VAC film” by Sumitomo Chemical Co., Ltd. There are biaxially oriented films.

  Further, those obtained by attaching a protective film to these optical films can also be used as the optical film. As the protective film, a transparent resin film is used, and as the transparent resin, for example, an acetyl cellulose resin typified by triacetyl cellulose or diacetyl cellulose, a methacrylic resin typified by polymethyl methacrylate, a polyester resin, or a polyolefin Resin, polycarbonate resin, polyether ether ketone resin, polysulfone resin and the like. The resin constituting the protective film may contain an ultraviolet absorber such as a salicylic acid ester compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyanoacrylate compound, or a nickel complex salt compound. As the protective film, an acetyl cellulose resin film such as a triacetyl cellulose film is preferably used.

  Among the optical films described above, the linearly polarizing film is used in a state where a protective film is attached to one or both sides of a polarizer constituting the polarizer, for example, a polarizer film made of a polyvinyl alcohol-based resin. There are many. Moreover, although the above-mentioned elliptically polarizing film is a laminate of a linearly polarizing film and a retardation film, the polarizing film may also be in a state where a protective film is attached to one or both sides of the polarizer film. Many. When the pressure-sensitive adhesive layer according to the present invention is formed on such an elliptically polarizing film, the pressure-sensitive adhesive layer is usually formed on the retardation film side.

  A surface protective film is a film used for the purpose of protecting the surface of an optical film or the like, which is an object to be protected, from scratches and dirt. For example, a polarizing film, retardation film, light used for the production of liquid crystal display devices Various optical films such as a diffusion sheet and a reflective sheet are circulated in a state where a surface protective film is bonded to the surface (the surface on the opposite side of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive layer is provided on one side), and the liquid crystal Usually, the surface protective film is peeled off after being attached to a cell or the like. Examples of the base material of the surface protective film include polyolefin resins such as polyethylene, polypropylene, and polymethylpentene, fluorinated polyolefin resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyfluorinated ethylene, polyethylene naphthalate, polyethylene terephthalate, Polyester resin such as polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer, polyamide such as nylon 6, nylon 6,6, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, Ethylene-vinyl alcohol copolymer, vinyl alcohol, vinyl polymer such as vinylon, cellulose triacetate, cellulose diacetate, cellulosic resin such as cellophane, polymethyl methacrylate, Ethyl Li methacrylate, polyethyl acrylate, polybutyl acrylate such acrylic resins, other, polystyrene, polycarbonate, polyarylate, polyimide and the like.

In viscous adhesive with a resin film, in its pressure-sensitive adhesive layer surface, a release film is adhered, preferably temporarily attached protected until use. The release film used here is, for example, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, and the like, and the bonding surface with the pressure-sensitive adhesive layer of the substrate is separated by a silicone treatment. It can be one that has undergone mold processing.

  The resin film with an adhesive is formed by, for example, applying the adhesive composition described above on the release film as described above to form an adhesive layer, and further laminating the resin film on the obtained adhesive layer. It can be produced by a method, a method in which a pressure-sensitive adhesive composition is applied on a resin film to form a pressure-sensitive adhesive layer, a release film is bonded to the surface of the pressure-sensitive adhesive to protect it, and a resin film with a pressure-sensitive adhesive is obtained.

  The thickness of the pressure-sensitive adhesive layer is not particularly limited, but it is usually preferably 30 μm or less, more preferably 10 μm or more, and further preferably 10 to 20 μm. When the thickness of the pressure-sensitive adhesive layer is 30 μm or less, the adhesiveness under high temperature and high humidity is improved, and there is a tendency that the possibility of floating or peeling between the glass substrate and the pressure-sensitive adhesive layer is reduced. It is preferable because reworkability tends to improve, and if the thickness is 10 μm or more, even if the dimension of the optical film bonded thereto changes, the adhesive layer follows the change in dimension and fluctuates. Therefore, it is preferable because there is no difference between the brightness of the peripheral edge of the liquid crystal cell and the brightness of the center, and white spots and color unevenness tend to be suppressed. Conventionally, in general, the thickness of the pressure-sensitive adhesive layer adhered to the liquid crystal cell glass has been 25 μm as a standard. However, in the present invention, even if the thickness is 20 μm or less, sufficient performance as the pressure-sensitive adhesive layer is exhibited. To do.

With viscous adhesive resin film, after an optical laminate stuck to the glass substrate, if there is some disadvantage to peel the resin film from the glass substrate, the adhesive layer is peeled off along with the resin film Since the surface of the glass substrate that has been in contact with the pressure-sensitive adhesive layer hardly causes fogging or adhesive residue, it is easy to re-attach the resin film with the pressure-sensitive adhesive again to the glass substrate after peeling. That is, it is excellent in so-called reworkability.

[Optical laminate]
The optical film pressure-sensitive adhesive described above is laminated on a glass substrate with an adhesive layer of that, Ru is an optical stack. In order to laminate an optical film with an adhesive on a glass substrate to form an optical laminate, for example, the release film is peeled off from the optical film with an adhesive obtained as described above, and the exposed adhesive layer is removed from the surface of the glass substrate. You just have to stick together. Here, as a glass substrate, the glass substrate of a liquid crystal cell, the glass for glare-proof, the glass for sunglasses etc. can be mentioned, for example. Above all, an optical film with adhesive (upper polarizing film) is laminated on the glass substrate on the front side (viewing side) of the liquid crystal cell, and another optical film with adhesive (lower polarizing film) on the glass substrate on the rear side of the liquid crystal cell. The optical laminate formed by laminating is preferable because it can be used as a liquid crystal display device. Examples of the material for the glass substrate include soda lime glass, low alkali glass, and non-alkali glass.

  The optical layered body of the present invention can be used as a liquid crystal cell of a liquid crystal display device. The liquid crystal display device formed from the optical laminate of the present invention includes, for example, a notebook type, a desktop type, a liquid crystal display for personal computers including a PDA (Personal Digital Assistance), a television, an in-vehicle display, an electronic dictionary, and a digital camera. It can be used for digital video cameras, electronic desk calculators, watches, etc.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited by these examples. In the examples, “parts” and “%” representing the amount used or content are based on weight unless otherwise specified.

In the following examples, the non-volatile content is a value measured by a method according to JIS K 5407. Specifically, the adhesive solution was taken in a petri dish at an arbitrary weight, and the residual non-volatile content after drying for 2 hours at 115 ° C. in an explosion-proof oven was expressed as a percentage of the weight of the solution first measured. It is. The weight average molecular weight is measured by placing two “TSK gel GMH _HR- H (S)” manufactured by Tosoh Corporation as a column in series on a GPC device and using tetrahydrofuran as the eluent. Standard polystyrene conversion was performed under the conditions of a concentration of 5 mg / ml, a sample introduction amount of 100 μl, a temperature of 40 ° C., and a flow rate of 1 ml / min.

  First, an example of producing an acrylic resin is shown.

[Polymerization Example 1]
In a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer, 81.8 parts of ethyl acetate, 98.6 parts of butyl acrylate, 1.0 part of 2-hydroxyethyl acrylate, and 0.4 parts of acrylic acid The internal temperature was increased to 55 ° C. while the air in the apparatus was replaced with nitrogen gas and oxygen-free. Thereafter, a total amount of a solution prepared by dissolving 0.14 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. One hour after the addition of the initiator, an internal temperature of 54 to 56 was added while continuously adding ethyl acetate into the reaction vessel at an addition rate of 17.3 parts / hr so that the concentration of the acrylic resin excluding the monomer was 35%. The mixture was kept at 12 ° C. for 12 hours, and finally ethyl acetate was added to adjust the concentration of the acrylic resin to 20%. The obtained acrylic resin had a polystyrene equivalent weight average molecular weight Mw of 1,230,000 and Mw / Mn of 3.9 by GPC. This is designated as acrylic resin A1. The structural unit derived from 2-hydroxyethyl acrylate which is a hydroxyl group-containing monomer in the acrylic resin A1 is 1%, and the structural unit derived from acrylic acid which is a carboxyl group-containing monomer is 0.4%. It is.

[Polymerization Example 2]
The monomer composition was changed to 81.8 parts ethyl acetate, 78.6 parts butyl acrylate, 20.0 parts methyl acrylate, 1.0 part 2-hydroxyethyl acrylate, and 0.4 part acrylic acid. Except for the above, an acrylic resin was produced in the same manner as in Polymerization Example 1. The obtained acrylic resin had a polystyrene equivalent weight average molecular weight Mw of 1,648,000 and Mw / Mn of 4.1 by GPC. This is designated as acrylic resin A2. In the acrylic resin A2, the proportion of structural units derived from 2-hydroxyethyl acrylate, which is a hydroxyl group-containing monomer, is 1%, and the proportion of structural units derived from acrylic acid, which is a carboxyl group-containing monomer, is 0.4. %.

  Next, examples and comparative examples in which pressure-sensitive adhesives were prepared using the acrylic resin produced above and applied to optical films are shown. In the following examples, the following were used as ionic compounds. The symbol of each compound is given for later reference, and the compounds called ionic solid 1 to ionic solid 5 are solid at room temperature of 25 ° C. and are called ionic liquid 1. The compound was liquid at room temperature of 25 ° C.

Ionic solid 1: N-butyl-4-methylpyridinium hexafluorophosphate (having the structure of the following formula, melting point 48 ° C.)

Ionic solid 2: N-hexylpyridinium hexafluorophosphate (having the structure of the following formula, melting point: 45 ° C.)

Ionic solid 3: N-octyl-4-methylpyridinium hexafluorophosphate (having the structure of the following formula, melting point: 44 ° C.)

Ionic solid 4: 1-methyl-3-ethylimidazolium hexafluorophosphate (having the structure of the following formula, melting point 62 ° C.)

Ionic solid 5: Tetrabutylammonium hexafluorophosphate (having the structure of the following formula, melting point 78 ° C.)

Ionic liquid 1: N-hexyl-4-methylpyridinium hexafluorophosphate (having the structure of the following formula, melting point: 18 ° C.)

  Moreover, the following were used as a crosslinking agent and a silane compound (all are brand names).

<Crosslinking agent>
Takenate D160N: Ethyl acetate solution of trimethylolpropane adduct of hexamethylene diisocyanate (solid content concentration 75%), obtained from Mitsui Chemicals Polyurethanes.
Coronate L: Ethylene acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75%), obtained from Nippon Polyurethane Co., Ltd.

<Silane compounds>
KBE-402: Glycidoxypropyldiethoxymethylsilane (liquid), obtained from Shin-Etsu Chemical Co., Ltd.
KBM-403: Glycidoxypropyltrimethoxysilane (liquid), obtained from Shin-Etsu Chemical Co., Ltd.

[Examples 1-4, Example 5 (reference) and Comparative Examples 1-3]
(A) Manufacture of pressure-sensitive adhesive For 100 parts of the solid content of the acrylic resin A1 obtained in Polymerization Example 1, 0.8 parts of the cross-linking agent “Takenate D160N” was obtained in a solid content and 0.8 parts of the silane compound “KBE-402”. 5 parts and the ionic compounds shown in Table 1 were mixed in the amounts shown therein, and ethyl acetate was further added so that the solid concentration was 13% to obtain a pressure-sensitive adhesive composition.

(B) Production of resin film with pressure-sensitive adhesive Each of the above pressure-sensitive adhesive compositions was subjected to release treatment of a polyethylene terephthalate film (trade name “PET 3811”, obtained from Lintec Co., Ltd .; called a separator) subjected to release treatment. It applied to the surface using an applicator so that the thickness after drying would be 15 μm, and dried at 90 ° C. for 1 minute to obtain a sheet-like pressure-sensitive adhesive. Next, on one side of a polarizing film having a three-layer structure in which both sides of a polyvinyl alcohol polarizer to which iodine is adsorbed and oriented are sandwiched between protective films made of triacetyl cellulose, a surface opposite to the separator of the sheet-like adhesive obtained above ( The pressure-sensitive adhesive surface) was pasted with a laminator and then cured for 7 days under conditions of a temperature of 23 ° C. and a relative humidity of 65% to obtain a polarizing film with a pressure-sensitive adhesive. For each pressure-sensitive adhesive layer after curing, the gel fraction was measured by the method described above, and the results are shown in Table 2.

(C) Evaluation of antistatic property of resin film with adhesive When the separator of the obtained polarizing film with adhesive is peeled off, the surface resistance value of the adhesive is measured by a surface resistivity measuring device [“Mitsubishi Chemical Co., Ltd. Measured with Hirest-up MCP-HT450 "(trade name)] to evaluate antistatic properties. If the surface resistance value is on the order of 10 ¹¹ Ω / □ or less, good antistatic properties can be obtained. The antistatic property was evaluated immediately after the curing of the polarizing film with an adhesive was completed. In addition, in order to see the change over time when stored for a long period of time, after the cured polarizing film with adhesive was stored in an oven at a temperature of 60 ° C. and a relative humidity of 70% for 6 days, the separator was peeled off in the same manner as above. The surface resistance value of the adhesive was measured. Here, storing for 6 days at a temperature of 60 ° C. and a relative humidity of 70% has almost the same effect as storing for 6 months at room temperature. The results are summarized in Table 2.

(D) Production and Evaluation of Optical Laminate After separating the separator from the polarizing film with adhesive produced in (b) above, the adhesive surface was placed on a glass substrate for liquid crystal cells [“1737” (trade name, manufactured by Corning) )] Was pasted on one side to produce an optical laminate. The optical laminate was subjected to a heat resistance test stored for 300 hours under a dry condition at a temperature of 80 ° C., a moisture heat resistance test stored for 300 hours at a temperature of 60 ° C. and a relative humidity of 90%, and 70 ° C. In the case of performing a heat shock resistance test in which the process of lowering the temperature to -30 ° C. from the state of heating to 70 ° C. and then raising the temperature to 70 ° C. as one cycle (one hour) is repeated 100 cycles, the post-test optics The laminate was visually observed.
The results were classified according to the following criteria and summarized in Table 2.

<Evaluation Criteria for Durability against Heat, Wet Heat and Heat Shock (referred to as “HS” in Table 2)> A: No change in appearance such as floating, peeling or foaming is observed.
○: Almost no change in appearance such as floating, peeling or foaming.
Δ: Appearance changes such as floating, peeling and foaming are slightly noticeable.
X: Remarkable changes in appearance such as floating, peeling, foaming, etc.

[Example 6]
For 100 parts of the solid content of the acrylic resin A2 obtained in Polymerization Example 2, 0.5 part of the cross-linking agent “Coronate L”, 0.5 part of the silane compound “KBM-403”, and ionicity 7.5 parts of solid 3 was mixed, and ethyl acetate was further added so that the solid content concentration was 13% to obtain a pressure-sensitive adhesive composition. Using this pressure-sensitive adhesive composition, the same evaluation as in Examples 1 to 5 was performed, and the results are summarized in Table 2.

  As can be seen from Tables 1 and 2, Examples 1 to 5 in which 1 part of the ionic solid defined in the present invention is blended with 100 parts of the acrylic resin to form a pressure-sensitive adhesive, and 7.5 of the ionic solid. In Example 6, in which a part of the pressure-sensitive adhesive was composed, the same antistatic property was exhibited at the initial stage of production as compared with Comparative Example 1 in which the ionic liquid was blended, and the antistatic property was substantially changed even after a long period of time. Moreover, almost satisfactory results were obtained in heat resistance, heat and humidity resistance, and heat shock resistance.

  On the other hand, Comparative Example 1 in which N-hexyl-4-methylpyridinium hexafluorophosphate (ionic liquid 1), which is liquid at 25 ° C., was used to form a pressure-sensitive adhesive, had good antistatic properties at the initial production stage. However, when stored for 6 days at a temperature of 60 ° C. and a relative humidity of 70%, which is a warming acceleration test, the surface resistance value after separation of the separator is 10 times or more compared to the initial value. There was a tendency for antistatic properties to decline. On the other hand, the same ionic solid 3 was blended, but from the results of Example 3, Comparative Example 2 and Comparative Example 3 in which the amount was changed, the blending amount of the ionic solid with respect to 100 parts of acrylic resin was 0.1 part. The effect of imparting antistatic properties was insufficient, and when the amount was 10 parts, durability was insufficient.

The optical laminate of the present invention is suitably used in a liquid crystal display device.

Claims (5)

Polarizing film and the pressure-sensitive adhesive optical film with the pressure-sensitive adhesive layer formed on one surface of the optical film selected from a phase difference film is an optical laminate formed by stacking a glass substrate at the adhesive layer side, The pressure-sensitive adhesive layer
(A) The following formula (I)

(In the formula, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a C 1-14 alkyl group or an aralkyl group, each of which may be substituted with a C 1-10 alkoxy group)
100 parts by weight of an acrylic resin containing a structural unit derived from a monomer having a polar functional group, the structural unit derived from a (meth) acrylic acid ester represented by
(B) 0.2 to 8 parts by weight of an ionic compound having an organic cation selected from a pyridinium cation and an imidazolium cation and being solid at room temperature ,
(C) 0.01 to 10 parts by weight of a crosslinking agent, and
(D) An optical laminate characterized by being formed from a composition containing 0.01 to 10 parts by weight of a silane compound . 2. The optical laminate according to claim 1, wherein the ionic compound (B) is present at a ratio of 0.2 to 3 parts by weight with respect to 100 parts by weight of the acrylic resin (A). The optical layered product according to claim 1 or 2, wherein the ionic compound (B) has an anion component containing a fluorine atom . The optical laminate according to claim 3 , wherein the anion component is a hexafluorophosphate anion . The optical layered product according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has a gel fraction in the range of 50 to 99% by weight .