KR102403283B1 - Adhesive composition for optical film, adhesive layer, optical member and optical display - Google Patents

Abstract

<Problem> Even when used for a single-sided protective polarizing plate, it is possible to improve durability in harsh environments (high temperature, high humidity, thermal shock) while suppressing both warpage and dents, and furthermore, optical with excellent reworkability (processability) An adhesive for a film is provided.
<Solution> As an optical film adhesive containing (meth)acrylic acid ester copolymer (A), the (meth)acrylic acid ester copolymer (A) is (a1) (meth)acrylic acid alkyl ester monomer-derived structural unit 10 mass % or more and 95 mass % or less; (a2) 5 mass % or more and 90 mass % or less of structural units derived from the (meth)acrylic-acid alkyl ester monomer which has an alkoxyalkyl group or an alkoxyalkylene glycol group; (a3) More than 0% by mass and 20% by mass or less of structural units derived from a functional group-containing monomer that is a (meth)acrylic acid derivative monomer having one radically polymerizable functional group (provided that the above-mentioned (a1), (a2) and (a3) derived The total amount of structural units is 100% by mass; including, the glass transition temperature of the (meth)acrylic acid ester copolymer (A) is greater than -55 ° C. and -50 ° C. or less, and the weight average molecular weight is 700,000 or more and 2 million or less, Adhesive for optical film.

Description

Adhesive for optical film, pressure-sensitive adhesive layer, optical member and image display device {ADHESIVE COMPOSITION FOR OPTICAL FILM, ADHESIVE LAYER, OPTICAL MEMBER AND OPTICAL DISPLAY}

The present invention relates to an adhesive for an optical film. Further, the present invention relates to a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive for an optical film, an optical member using the pressure-sensitive adhesive layer, and an image display device using the optical member.

Currently, flat display panels such as a liquid crystal display panel (LCD) and a plasma display panel (PD) are mainly used as display panels. A laminate in which a plurality of films are laminated is usually bonded to the surface of a flat panel display panel. For example, in a LCD, an optical film such as a polarizing plate, a retardation plate, a viewing angle magnifying film and a luminance improving film is laminated on the surface of a liquid crystal panel usually. In addition, each layer constituting the flat-panel display panel may be bonded by a pressure-sensitive adhesive layer usually formed of various types of pressure-sensitive adhesive.

On the other hand, a cheaper and thinner polarizing plate is calculated|required in recent years. As one form, a single-sided protective polarizing plate (single-sided protective polarizing film) using only one protective film on one side of the polarizer is proposed for a conventional double-sided protective polarizing plate (double-sided protective polarizing film) in which protective films are bonded to each other on both sides of a polarizer. is becoming However, this single-sided protective polarizing plate is different from the conventional double-sided protective polarizing plate, and it is known that durability, particularly, heat durability or heat shock cycle test, greatly shrinks.

For this reason, the same durability as compared to the conventional double-sided protective polarizing plate is required for such a single-sided protective polarizing plate. For this reason, in addition to suppressing generation|occurrence|production of peeling or float, it is calculated|required to suppress the bubble which generate|occur|produces in the polarizing plate edge part (end part) by a polarizing plate shrink|contracting large at the time of a durability test.

In addition, although warpage of the panel tends to occur due to large shrinkage during the durability test, compatibility between suppression of such warpage and suppression of dents occurring in the pressure-sensitive adhesive layer is also required.

As an adhesive that can be used for a conventional double-sided protective polarizing plate, for example, in Patent Documents 1 to 4, a pressure-sensitive adhesive containing a copolymer having a glass transition temperature in the range of -47.4°C to -20°C is proposed. Moreover, in patent document 5 - patent document 7, the pressure-sensitive adhesive for polarizing plates containing the copolymer whose glass transition temperature is -55 degreeC or less is proposed.

[Prior art literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-084541

[Patent Document 2] Japanese Patent Laid-Open No. 2009-108113

[Patent Document 3] Japanese Patent Laid-Open No. 2009-280776

[Patent Document 4] Japanese Patent Laid-Open No. 2007-238853

[Patent Document 5] Japanese Patent Laid-Open No. 2004-224873

[Patent Document 6] Japanese Patent Laid-Open No. 2003-193013

[Patent Document 7] Japanese Patent Laid-Open No. 2003-193014

However, according to the examination of this inventor, it became clear that there exist the following problems. When the pressure-sensitive adhesive of Patent Documents 1 to 7 is used for a single-sided protective polarizing plate, durability in harsh environments (high temperature, high humidity, heat shock) It became clear that there existed a phenomenon that suppression of bubble and suppression of peeling of a polarizing plate) fell. Moreover, it turned out that there exists a problem that it is easy to generate|occur|produce warp and dent. In addition to this, it was also found that there was a problem that the reworkability (workability) was not sufficient.

The present invention has been made in view of the above circumstances. In other words, even when used in a single-sided protective polarizing plate, durability in harsh environments (high temperature, high humidity, thermal shock) (in particular, suppression of bubbles generated at the edge of the polarizing plate and suppression of peeling of the polarizing plate) It aims at providing the adhesive for optical films which can suppress both curvature and dent and is excellent also in rework property (processability).

MEANS TO SOLVE THE PROBLEM This inventor earnestly researched in order to solve the said subject. As a result, it was found that the above problems can be solved by an adhesive containing a (meth)acrylic acid ester copolymer having a specific structure, and the present invention has been completed.

In other words, the present invention is a pressure-sensitive adhesive for an optical film comprising a (meth)acrylic acid ester copolymer (A), wherein the (meth)acrylic acid ester copolymer (A) is (a1) a (meth)acrylic acid alkyl ester monomer-derived composition Units 10% by mass or more and 95% by mass or less; (a2) 5 mass % or more and 90 mass % or less of structural units derived from the (meth)acrylic-acid alkylester monomer which has an alkoxyalkyl group or an alkoxyalkylene glycol group; (a3) More than 0% by mass and not more than 20% by mass of structural units derived from a functional group-containing monomer that is a (meth)acrylic acid derivative monomer having one radically polymerizable functional group (provided that (a1), (a2) and (a3)-derived composition The total amount of units is 100% by mass), the glass transition temperature of the (meth)acrylic acid ester copolymer (A) exceeds -55°C and is -50°C or less, and the (meth)acrylic acid ester copolymer (A) ) is an adhesive for optical films having a weight average molecular weight of 700,000 or more and 2,000,000 or less.

According to the present invention, even when used in a single-sided protective polarizing plate, durability (in particular, suppression of bubbles generated at the edge of the polarizing plate and suppression of peeling of the polarizing plate) in harsh environments (high temperature, high humidity, thermal shock) can be improved. A pressure-sensitive adhesive for an optical film is provided. Furthermore, the adhesive for optical films which can suppress both curvature and dent and is excellent also in rework property (processability) is provided.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated.

[Adhesive for optical film]

The pressure-sensitive adhesive for an optical film of the present invention contains a (meth)acrylic acid ester copolymer (A), and the (meth)acrylic acid ester copolymer (A) is (a1) 10 mass of structural units derived from (meth)acrylic acid alkyl ester monomer % or more and 95 mass% or less; (a2) 5 mass % or more and 90 mass % or less of structural units derived from the (meth)acrylic-acid alkylester monomer which has an alkoxyalkyl group or an alkoxyalkylene glycol group; (a3) More than 0% by mass and not more than 20% by mass of structural units derived from a functional group-containing monomer that is a (meth)acrylic acid derivative monomer having one radically polymerizable functional group (provided that the total amount of (a1), (a2) and (a3) is 100% by mass), and the glass transition temperature of the (meth)acrylic acid ester copolymer (A) exceeds -55°C and is -50°C or less, and the weight of the (meth)acrylic acid ester copolymer (A) Average molecular weight is 700,000 or more and 2 million or less.

According to the adhesive for an optical film of the present invention having such a configuration, even when used in a single-sided protective polarizing plate, durability in harsh environments (high temperature, high humidity, thermal shock) (in particular, suppression of bubbles generated at the edge of the polarizing plate and suppression of peeling of a polarizing plate) can be improved. Furthermore, both warpage and dents can be suppressed, and reworkability (workability) is also excellent.

In recent years, a cheaper and thinner polarizing plate is calculated|required. As one aspect, the single-sided protective polarizing plate which used only one protective film on the single side|surface of a polarizer is proposed. In a single-sided protective polarizing plate, the suppression force of the shrinkage|contraction of the polarizer by a protective film becomes small. For this reason, the present inventor discovered that it was easy to generate|occur|produce the shrinkage|contraction by heating etc., and the problem that a bubble was easy to generate|occur|produce especially in the edge part of a polarizing plate occurred. Here, the present inventor earnestly examined so that this problem might be solved. As a result, a pressure-sensitive adhesive containing a (meth)acrylic acid ester copolymer (A) having a glass transition temperature lower than that of a conventional copolymer (more than -55°C and -50°C or less) and having a weight average molecular weight of 700,000 or more and 2 million or less It has been found that the above problem can be solved by using. By using the (meth)acrylic acid ester copolymer with a low glass transition temperature, it can track the polarizing plate contracted by heating etc., and can suppress generation|occurrence|production of a bubble in an edge part. For suppression of air bubbles at this edge portion, it is advantageous that the glass transition temperature of the (meth)acrylic acid ester copolymer is lower. However, when the glass transition temperature of a (meth)acrylic acid ester copolymer becomes low, durability will also fall and it will become impossible to suppress also a dent.

From there, by setting the weight average molecular weight of the (meth)acrylic acid ester copolymer (A) in a specific range (700,000 or more and 2 million or less), durability in harsh environments (high temperature, high humidity, thermal shock) (especially, It discovered that suppression of the bubble which generate|occur|produces in the edge part of a polarizing plate, and suppression of peeling of a polarizing plate) could be improved. Furthermore, it was discovered that both curvature and dent can be suppressed, and also the adhesive excellent in rework property (workability) can be obtained further.

On the other hand, the above mechanism is by guess and the present invention is not limited to the above mechanism in any way.

Hereinafter, each component which comprises the adhesive for optical films which concerns on this invention is demonstrated in order.

In addition, in this specification, "(meth)acrylic acid ester" is a generic term for acrylic acid ester and methacrylic acid ester. Compounds containing (meth), such as (meth)acrylamide, etc. are similarly a generic name of the compound which has "meta" in the name, and the compound which does not have "meta". In addition, "(meth)acrylic acid ester copolymer (A)" is also called only "copolymer (A)".

<(meth)acrylic acid ester copolymer (A)>

The pressure-sensitive adhesive for an optical film according to the present invention essentially includes the (meth)acrylic acid ester copolymer (A).

The weight average molecular weight (Ml) of the copolymer (A) according to the present invention by gel permeation chromatography (GPC) is 700,000 or more and 2 million or less. When a weight average molecular weight (Ml) is less than 700,000, dents generate|occur|produce and the durability in high temperature and the rework property after a heating fall. On the other hand, when it exceeds 2 million, warpage occurs.

The weight average molecular weight (Ml) by gel permeation chromatography (GPC) of the copolymer (A) is 900,000 or more and 2 million or less from the viewpoint of further improving durability in a harsh environment (high temperature, high humidity, thermal shock) it is preferable As for the said weight average molecular weight, it is more preferable that they are more than 1 million and 2 million or less. If it is a person skilled in the art, the weight average molecular weight (Ml) of the copolymer (A) of this invention can be easily controlled as follows. In other words, it can be easily controlled by appropriately adjusting reaction conditions such as the type and/or amount of the polymerization initiator used in the polymerization reaction described later, the reaction temperature, and the reaction time.

In addition, the weight average molecular weight (Ml) of a copolymer (A) can be measured by gel permeation chromatography (GPC). In detail, it can measure by the method shown in an Example.

In addition, the (meth)acrylic acid ester copolymer (A) according to the present invention has a glass transition temperature of greater than -55°C and -50°C or less. When a glass transition temperature is -55 degrees C or less, it becomes easy to generate|occur|produce a dent. On the other hand, when a glass transition temperature exceeds -50 degreeC, in a harsh environment (high temperature, high humidity, thermal shock), it becomes easy to generate|occur|produce a bubble at an edge part. It is preferable that it is -51 degreeC or less, and, as for the upper limit of the glass transition temperature of a copolymer (A), it is more preferable that it is -52 degreeC or less.

In addition, in the present specification, the glass transition temperature of the (meth)acrylic acid ester copolymer (A) is a theoretical value calculated by the formula of Ff from the glass transition temperature of the homopolymer of the monomer constituting the polymer and the content ratio thereof.

Equation of TF: 1/TV = (w1/TV1) + (w2/TV2)+... + (t/TV)

Tg: the glass transition temperature (K) of the polymer

TG1, TG2, ... TG: Glass transition temperature (K) of the homopolymer of each monomer

w1, w2, ... ｗｎ: weight fraction of each monomer

The theoretical value of the glass transition temperature required by the above formula of FHF is very consistent with the measured glass transition temperature required by differential scanning calorimetry (DSC), dynamic viscoelasticity, or the like.

The glass transition temperature of the copolymer (A) can be easily controlled by appropriately adjusting the type and content of the monomers (especially (a1) and (a2)) used, the weight average molecular weight of the copolymer (A), and the like.

As a structural unit constituting the copolymer (A) in the present invention,

(a1) 10% by mass or more and 95% by mass or less of structural units derived from an alkyl (meth)acrylic acid ester monomer (hereinafter, simply referred to as “component (a1)”);

(a2) 5 mass % or more and 90 mass % or less of structural units derived from the (meth)acrylic acid alkyl ester monomer (hereinafter also referred to simply as "component (a2)") having an alkoxyalkyl group or an alkoxyalkylene glycol group;

(a3) More than 0% by mass and not more than 20% by mass of structural units derived from a functional group-containing monomer (hereinafter simply referred to as “component (a3)”) which is a (meth)acrylic acid derivative monomer having one radically polymerizable functional group (provided that ( The total amount of a1), (a2) and (a3) is 100 mass %).

In the present specification, for example, as a raw material monomer used when copolymer X is obtained by copolymerization that "copolymer X includes a structural unit derived from _the monomer Y1 and _a structural unit derived from the monomer Y2" in the present specification, _the monomer Y1 and monomer Y ₂ .

Hereinafter, the structural unit derived from each monomer which can comprise the copolymer (A) which concerns on this invention is demonstrated in order.

[(a1) Structural unit derived from (meth)acrylic acid alkyl ester monomer]

The copolymer (A) according to the present invention includes (a1) a structural unit derived from an alkyl (meth)acrylate monomer. It is thought that this component (a1) has the significance of securing adhesiveness and securing basic characteristics by being included as a structural unit of the (meth)acrylic acid ester copolymer (A) according to the present invention.

In the present invention, the structure of the (meth)acrylic acid alkyl ester monomer is not particularly limited as long as an alkyl group is introduced into the ester moiety of the monomer. However, the (meth)acrylic acid alkyl ester monomer which has an alkoxyalkyl group or an alkoxyalkylene glycol group shall be classified as a component (a2).

Although carbon number in particular of the said alkyl group is not restrict|limited, 1 or more and 18 or less are preferable. Moreover, as for carbon number of an alkyl group, 2 or more and 18 or less are more preferable from a viewpoint of the compatibility at the time of using together with the glass transition temperature of a copolymer (A) and a crosslinking agent (B) mentioned later. 3 or more and 16 or less are further more preferable, and, as for this carbon number, 4 or more and 12 or less are especially preferable. Further, the alkyl group may be any of linear, branched or cyclic. It is preferable that it is linear or branched from a viewpoint of lowering|hanging the glass transition temperature of a copolymer (A). On the other hand, when the alkyl group is cyclic, carbon number is 3 or more.

Although it does not restrict|limit especially as a related alkyl group, A methyl group, an ethyl group, a propyl group, isopropyl group, n-butyl group, a b-butyl group, t-butyl group, an isobutyl group, n-pentyl group, an isopentyl group, n- Hexyl group, 2-hexyl group, 3-hexyl group, cyclohexyl group, 1-methylcyclohexyl group, n-heptyl group, 2-heptyl group, t-heptyl group, isoheptyl group, t-heptyl group, n- Octyl group, isooctyl group, t-octyl group, 2-ethylhexyl group, nonyl group, isononyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, An octadecyl group, a cyclohexyl group, etc. are mentioned. In particular, a methyl group, n-butyl group, n-hexyl group, 2-ethylhexyl group, nonyl group and isononyl group are preferable from the viewpoint of securing adhesiveness and ensuring basic characteristics.

Therefore, specific examples of the (meth)acrylic acid alkyl ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, Isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hexyl (meth)acrylate , heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like. Among them, n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferable from the viewpoint of improving heat durability and adhesive force, particularly reworkability. In addition, component (a1) can be used individually or in mixture of 2 or more types. In addition, a commercially available product may be used for component (a1), and a synthetic substance may be used for it. As an example of a commercially available product, 2EP, BAA (above, the Nippon Shokubai Co., Ltd. make) etc. are mentioned.

The content of the structural unit derived from the component (a1) in the copolymer (A) according to the present invention (the compounding amount of the (meth)acrylic acid ester monomer as the raw material monomer) is the component (a1), the component (a2) and the component (a3) When the total amount of the structural unit derived from it is 100 mass %, they are 10 mass % or more and 95 mass % or less. When content of a component (a1) is less than 10 mass %, the ratio of components other than (a1) which occupies for a copolymer (A) increases. This makes it difficult to balance the suppression of air bubbles at the edge, adhesion, durability, and suppression of warpage and dents. On the other hand, when this content exceeds 95 mass %, it becomes difficult to provide cohesive force to an adhesive, and adhesiveness falls.

The content of the constituent units derived from component (a1) is preferably 13 mass% or more and 88 mass% or less when the total amount of constituent units derived from component (a1), component (a2) and component (a3) is 100 mass%. . As for this content, it is more preferable that they are 15 mass % or more and 80 mass % or less, and it is still more preferable that they are 50 mass % or more and 79 mass % or less.

[(a2) Structural unit derived from (meth)acrylic acid alkyl ester monomer having an alkoxyalkyl group or an alkoxyalkylene glycol group]

The (meth)acrylic acid ester copolymer (A) of this invention contains the structural unit derived from the (meth)acrylic acid alkyl ester monomer which has an alkoxyalkyl group or an alkoxyalkylene glycol group.

When the monomer constituting the (meth)acrylic acid ester copolymer (A) corresponds to both the component (a1) and the component (a2), it shall be classified as a component (a2).

The component (a2) is not particularly limited as long as it has an alkoxyalkyl group or alkoxyalkylene glycol group structure in the (meth)acrylic acid ester molecule. When such a component is contained in the adhesive of this invention, it is thought that it has the effect|action of improving adhesiveness and durability. Moreover, by including the structural unit derived from component (a2), it becomes easy to control a glass transition temperature within the range of this invention, and the bubble in an edge part can be suppressed.

In the alkoxyalkyl group or the alkoxyalkylene glycol group, the number of carbon atoms in the alkoxy moiety is not particularly limited. However, it is preferable that it is 1 or more and 20 or less from the viewpoint of a balance between the improvement of adhesiveness and improvement of durability, and even suppression of air bubbles at the edge portion. It is more preferable that it is 2 or more and 18 or less, and, as for this carbon number, it is still more preferable that they are 2 or more and 10 or less.

In addition, carbon number in particular of the alkyl part in an alkoxyalkyl group is not restrict|limited. However, it is preferable that it is 1 or more and 6 or less, and it is more preferable that it is 1 or more and 4 or less from a viewpoint for the balance of adhesive improvement and durability improvement, and also suppression of the bubble in an edge part.

The number of carbon atoms in the alkylene moiety in the alkoxyalkylene glycol group is not particularly limited. However, from a viewpoint for the balance of adhesive improvement and durability improvement, and also suppression of bubbles in an edge part, 1 or more and 4 or less are preferable, and, as for the carbon number, 1 or more and 3 or less are more preferable.

Component (a2) is preferably a compound represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁₁ is a hydrogen atom or a methyl group, and R ₁₂ is an alkoxyalkyl group or -(AO)nX.

Preferred alkoxyalkyl groups are those having an alkoxy group having 1 to 4 carbon atoms and an alkyl group having 1 to 4 carbon atoms, methoxymethyl group, ethoxymethyl group, methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, methoxypropyl group group, an ethoxypropyl group, a methoxybutyl group, an ethoxybutyl group, etc. are mentioned. As a more preferable alkoxyalkyl group, an ethoxymethyl group, an ethoxyethyl group, a propoxyethyl group, a butoxyethyl group, an ethoxypropyl group, an ethoxybutyl group, etc. are mentioned.

Said A is a C1-C4 alkylene group, and a methylene group, an ethylene group, a trimethylene group, a propylene group, or a butylene group is mentioned. Said n is 1 or more and 10 or less, Preferably it is 1 or more and 4 or less.

X is an alkyl group having 1 or more and 20 or less carbon atoms. The related alkyl group may be linear or branched. The carbon number is preferably 2 or more and 18 or less, and more preferably 2 or more and 10 or less. Examples of the relevant alkyl group may be the same as the alkyl group exemplified in the component (a1) above, but an ethyl group or a propyl group is particularly preferable.

Specific examples of the component (a2) include methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, ethoxyethyl (meth)acrylate, propoxyethyl (meth)acrylate, butoxyethyl (meth)acryl rate, methoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate; Ethoxy-diethylene glycol (meth) acrylate, ethoxy-triethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate, methoxy-diethylene glycol (meth) acrylate, propoxy -Diethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate (2-ethylhexyloxy-diethylene glycol (meth) acrylate ), methoxy-polyethylene glycol (meth)acrylate (n=4 or more and 10 or less), methoxy-dipropylene glycol (meth)acrylate, and the like.

Among these, ethoxymethyl (meth)acrylate, ethoxyethyl (meth)acrylate, propoxyethyl (meth) in particular from the same viewpoints as the balance of adhesion improvement and durability improvement, and suppression of air bubbles at the edge portion. Acrylate, butoxyethyl (meth)acrylate, ethoxy-diethylene glycol (meth)acrylate, and 2-ethylhexyl-diglycol (meth)acrylate are more preferable.

Component (a2) may be used alone or in mixture of two or more. In addition, a commercially available product may be used for component (a2), and a synthetic substance may be used for it. Examples of commercially available products include LIGHT ACRYLATE EFC-A, Light Acrylate EHDG-ATT (above, manufactured by Kyoeisha Chemical Co., Ltd.), VISCOAT #190 (Osaka) ) Organic Chemicals Co., Ltd.) and the like.

Content of the structural unit derived from component (a2) in copolymer (A) is 5 mass % or more 90 when the total amount of the structural unit derived from (a1), (a2), and (a3) component is 100 mass % mass% or less. When this content is less than 5 mass %, a glass transition temperature (Tg) becomes high and the bubble in an edge part generate|occur|produces. On the other hand, when it exceeds 90 mass %, there exists a tendency for Tg to become low too much, and peeling will generate|occur|produce or dent resistance will deteriorate greatly. (a2) It is preferable that they are 5 mass % or more and 85 mass % or less, 5 mass % or more and 50 mass % or less, and, as for content of the structural unit derived from a component, it is more preferable that they are 10 mass % or more and 40 mass % or less.

In one embodiment, component (a1) may be included in an excess of the total amount of constituent units derived from components (a1), (a2) and (a3) compared to component (a2).

[(a3) Structural unit derived from a functional group-containing monomer which is a (meth)acrylic acid derivative monomer having one radically polymerizable functional group]

In a preferred embodiment of the present invention, the (meth)acrylic acid ester copolymer (A) contains a structural unit derived from a functional group-containing monomer which is a (meth)acrylic acid derivative monomer having one radical polymerizable functional group.

Here, "(meth)acrylic acid derivative" refers to the compound which can obtain (meth)acrylic acid as a starting material. Preferably, it is (meth)acrylic acid ester or (meth)acrylamide.

In other words, the component (a3) is preferably a (meth)acrylic acid ester monomer or (meth)acrylamide monomer having a (meth)acryloyl group and at least one functional group other than a (meth)acryloyl group.

Although component (a3) is an optional component, by being included in the pressure-sensitive adhesive of the present invention in combination with the above components (a1) and (a2), the desired effect of the present invention can be realized more efficiently.

Component (a3) has high reactivity with the crosslinking agent (B). Therefore, it is thought that it has the meaning of improving the cohesiveness and heat resistance of an adhesive layer by being contained as a structural unit of the copolymer (A) which concerns on this invention. In addition, the crosslinking density of the pressure-sensitive adhesive layer is increased, the pressure-sensitive adhesive layer is hardened, and the amount of deformation of the pressure-sensitive adhesive layer is reduced during re-peelability. For this reason, adhesive force is inferior, preferable rework property can be acquired, peeling can also be suppressed also in durability, and generation|occurrence|production of curvature and a dent can be suppressed.

On the other hand, when the monomer constituting the (meth)acrylic acid ester copolymer (A) corresponds to both the component (a1) and the component (a3), it is said to be classified into the component (a3).

As a functional group contained in component (a3), when using a crosslinking agent (B), the functional group which reacts with a crosslinking agent is preferable. A hydroxyl group, an acyl group, or an epoxy group is preferable, and, as for this functional group, a hydroxyl group is more preferable. By including the copolymer (A) obtained using the monomer containing such a functional group in an adhesive, a copolymer (A) is crosslinked with a crosslinking agent (B), and it is thought that durability under high temperature improves. In other words, in a preferred embodiment of the present invention, (a3) a (meth)acrylic acid derivative monomer having one radically polymerizable functional group is a (meth)acrylic acid ester monomer or (meth)acrylic acid ester monomer having a hydroxyl group, an acyl group or an epoxy group. ) It is an acrylamide monomer, an adhesive for optical films. Furthermore, a more preferable aspect of this invention is an aspect in which a copolymer (A) has a hydroxyl group.

Hereinafter, the (meth)acrylic acid ester monomer and (meth)acrylamide monomer which have a hydroxyl group, an acyl group, or an epoxy group are demonstrated.

«(a3-1) (meth)acrylic acid ester monomer having a hydroxyl group, an acyl group, or an epoxy group»

The (meth)acrylic acid ester monomer (hereinafter also referred to as component (a3-1)) having a hydroxyl group, an acyl group or an epoxy group typically has a structure represented by the following formula (2).

[Formula 2]

In Formula 2,

R ₄ is a hydrogen atom or a methyl group,

R ₅ is a single bond or a divalent organic group,

R ₆ is a hydroxyl group, an acyl group, or an epoxy group.

Although carbon number in particular of an acyl group is not restrict|limited, Preferably it is 1 or more and 18 or less, More preferably, it is 1 or more and 6 or less. On the other hand, the acyl group shall include an acetoacetoxy group.

Although the said divalent organic group is not restrict|limited in particular, A C1-C10 alkylene group is preferable. Examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, ethylene group, trimethylene group, propylene group, butylene group, hexylene group, cyclohexylene group, heptylene group, octylene group, 2-ethylhexylene group, A nonylene group, a decylene group, etc. are mentioned.

Further, the alkylene group or the acyl group may have at least one alkyl group having 1 to 8 carbon atoms, a phenoxy alkyl group (the number of carbon atoms in the alkyl group: 1 to 8 carbon atoms), a phenyl group or a cyclohexyl group as a substituent.

Specific examples of the component (a3-1) include, for example, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, 2-acetoacetoxyethyl ( Meth) acrylate, 2-hydroxymethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 1,4-cyclohexanedi Methanol mono(meth)acrylate etc. are mentioned. Among these, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, and acetoacetoxyethyl (meth)acrylate are preferable from an adhesive viewpoint.

Component (a3-1) can be used individually or in mixture of 2 or more types. In addition, a commercially available product may be used for the component (a3-1), and a synthetic substance may be used for it. As an example of a commercial product, For example, 2HEA (above, Nippon Shokubai Co., Ltd. make), 4HPA (above, Nippon Kasei Co., Ltd. product), LIGHT ESTER HOP (N), Light Ester HPO-A (N), Light Acrylate HOP-A, Epoxy Ester M-600A (above, manufactured by Kyoeisha Chemical Co., Ltd.), CHP (above, Nippon Chemical Co., Ltd.) company), GMA (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and AFA (above, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and the like.

«(a3-2) (meth)acrylamide monomer having a hydroxyl group, an acyl group or an epoxy group»

The (meth)acrylamide monomer (hereinafter also referred to as component (a3-2)) having a hydroxyl group, an acyl group or an epoxy group typically has a structure represented by the following formula (3).

[Formula 3]

In Formula 3,

R ₇ is a hydrogen atom or a methyl group, R ₈ is a single bond or a divalent organic group, R ₉ is a hydroxy group, an acyl group or an epoxy group, and R ₁₀ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

As a divalent organic group, a C1-C10 alkylene group is preferable. Moreover, the alkylene group or acyl group may have at least 1 C1-C8 alkyl group, a phenyl group, or a cyclohexyl group as a substituent.

Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a bb-butyl group, a t-butyl group, an isobutyl group, an n-hexyl group, a 2-hexyl group, 3 -Hexyl group, cyclohexyl group, 1-methylcyclohexyl group, n-heptyl group, 2-heptyl group, 3-heptyl group, isoheptyl group, t-heptyl group, n-octyl group, isooctyl group, t- Octyl group, 2-ethylhexyl group, nonyl group, isononyl group, decyl group, etc. are mentioned.

Although the number of carbon atoms in the acyl group is not particularly limited, it is preferably 1 or more and 18 or less, and more preferably 1 or more and 6 or less. On the other hand, the acyl group is considered to include an acetoacetoxy group.

As a specific example of a component (a3-2), N-(2-hydroxyethyl) (meth)acrylamide, N-(2-hydroxypropyl) (meth)acrylamide, N-(2,2- Dimethyl-(beta)-hydroxyethyl) (meth)acrylamide, diacetone (meth)acrylamide, etc. are mentioned. Among these, the viewpoint of an adhesive improvement to N-(2-hydroxyethyl) (meth)acrylamide is preferable.

A component (a3-2) can be used individually or even if it mixes 2 or more types. In addition, a commercially available product may be used for the component (a3-2), and a synthetic substance may be used for it. As an example of a commercially available product, HRA (registered trademark) (manufactured by KJ Chemicals Co., Ltd.), DAA (manufactured by Nippon Kasei Co., Ltd.), etc. are mentioned.

In addition, a component (a3-1) and a component (a3-2) may be used independently, respectively, and may be used in combination. When a component (a3-1) and a component (a3-2) are used in combination, hydrophilicity can be ensured. Thereby, the glass transition temperature of a copolymer (A) can be lowered|hung, having favorable adhesiveness with respect to a polar base material.

The content of the structural unit derived from the component (a3) in the copolymer (A) is 0 mass% when the total amount of the structural unit derived from the component (a1), the component (a2), and the component (a3) is 100% by mass. It is excess 20 mass % or less. When this content exceeds 20 mass %, suppression of the bubble in an edge part, adhesiveness, durability, and suppression of curvature and a dent will deteriorate by the raise influence of a raise of a glass transition temperature and a crosslinking degree. The lower limit of this content becomes like this. Preferably it is 0.1 mass % or more, More preferably, it is 0.5 mass % or more. In addition, the upper limit of this content becomes like this. Preferably it is less than 15 mass %, More preferably, it is 10 mass % or less. Preferably, it may be included in an amount of more than 0 mass% and 5 mass% or less.

[(a4): Structural units derived from monomers other than components (a1) to (a3)]

The copolymer (A) according to the present invention is a monomer other than the components (a1) to (a3) copolymerizable with the aforementioned components (a1) to (a3) as an optional component (hereinafter only “component (a4)” Also referred to as )) derived constituent units may be included.

As the component (a4), a known substance can be used as long as the effects of the present invention are not impaired. Specifically, For example, (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, fumaric acid anhydride, crotonic acid, itaconic acid, itaconic anhydride, myristoleic acid, palmitoleic acid, or a monomer having a carboxyl group such as oleic acid; Benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate, phenoxy (meth)acrylate, p-t-butylphenyl (meth)acrylate, phenoxyethyl (meth)acrylate , Phenoxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide modified nonyl phenol (meth)acrylate, ethylene oxide modified cresol (meth)acrylate, phenol ethylene oxide modified (meth) ) acrylate, 2-hydroxy-3-phenoxy propyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, cresyl (meth) acrylate, polystyryl (meth) monomers having a benzene ring such as acrylate; Hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth)acrylate, 2-naphthoxyethyl acrylate, 2-(4-methoxy-1-naphthoxy)ethyl (meth)acrylate, etc. a monomer having a naphthalene ring; monomers having a biphenyl ring such as biphenyl (meth)acrylate; having a phosphoric acid group such as 2-methacryloyloxyethyl diphenyl phosphate (meth)acrylate, trimethacryloyloxyethyl phosphate (meth)acrylate, triacryloyloxyethyl phosphate (meth)acrylate (meth) ) acrylic monomers; (meth)acrylic monomers having a sulfonic acid group such as sodium sulfopropyl (meth)acrylate, sodium 2-sulfoethyl (meth)acrylate, and sodium 2-acrylamide-2-methylpropane sulfonate; (meth)acrylic monomers having a urethane group such as urethane (meth)acrylate; (meth)acryl having an amino group, such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, N-t-butylaminoethyl (meth)acrylate, and (meth)acryloyloxyethyltrimethylammonium chloride monomer; vinyl monomers having a silane group, such as vinyl trimethoxysilane, vinyltriethoxysilane, vinyl tris(β-methoxyethyl)silane, vinyltriacetylsilane, and methacryloyloxypropyltrimethoxysilane; Styrene, chlorostyrene, α-methylstyrene, vinyltoluene, vinyl chloride, vinyl acetate, vinyl propionate, acrylonitrile, vinylpyridine, (meth)acryloylmorpholine, 2-(meth)acryloyloxy Ethyl phthalic acid etc. are mentioned.

The above-mentioned component (a4) may be used alone or in combination of two or more. Component (a4) is an olefin such as ethylene or propylene from the viewpoint that the reaction with the crosslinking agent (B) described later can be easily controlled, or that the molecular weight is difficult to increase when preparing the copolymer (A) according to the present invention. It is preferable not to contain a system monomer.

Content of the structural unit derived from component (a4) in a copolymer (A) is 0.01 mass part or more and 10 mass parts with respect to a total of 100 mass parts of the structural unit derived from component (a1), component (a2), and component (a3) It is preferable that it is less than part. More preferably, they are 0.1 mass part or more and 5 mass parts or less.

On the other hand, in the copolymer (A) according to the present invention, the glass transition temperature of the homopolymer among the components (a1) to (a4) is 50 ° C. or higher (meth) acrylic acid ester monomer (hereinafter only “component (a') It is preferable to (optionally) contain a structural unit derived from At 80 ° C. or higher, which is the heating durability test temperature, it softens, and the pressure-sensitive adhesive layer can have stress relaxation properties. Thereby, it is possible to suppress warpage. In addition, it has excellent polymerizability with the above-mentioned component (a1) and the like, It is excellent in that it can improve durability and adhesive force (especially rework property) and can suppress generation|occurrence|production of warp and dent.

<(meth)acrylic (co)polymer (F)>

In the pressure-sensitive adhesive for optical film according to the present invention, unlike the copolymer (A), the homopolymer contains a structural unit derived from a (meth)acrylic monomer having a glass transition temperature of 50° C. or higher, and at the same time a weight average than that of the copolymer (A). It is preferable to further include a (meth)acrylic (co)polymer (F) having a small molecular weight (Md) (hereinafter also referred to simply as "(co)polymer (F)"). The (co)polymer (F) contains structural units similar to those of the copolymer (A), but exists separately as an acrylic resin with a low molecular component, similarly to the high softening point resin (E) described later. Therefore, in the adhesive layer formed using the adhesive for optical films containing this (co)polymer (F), this (co)polymer (F) can move freely. It is excellent in that it becomes easy to provide stress relaxation property to an adhesive layer by this. Further, unlike the high softening point resin (E), the (co)polymer (F) has the same acrylic component as the copolymer (A), and therefore has good compatibility. Therefore, compared with the case where the pressure-sensitive adhesive layer contains the high softening point resin (E) (clouding can occur although little), it is excellent in that it becomes less cloudy (preferably it does not become cloudy). For this reason, by making the said (co)polymer (F) also have all the above-mentioned characteristics, the hardness of the adhesive layer at room temperature which requires dent resistance can be ensured. In addition, it is excellent in that it softens at 80 degreeC or more which is the test temperature of the heating durability which curvature occurs, and gives stress relaxation property to an adhesive layer, and it becomes possible to suppress curvature.

[Weight average molecular weight of (co)polymer (F)]

The weight average molecular weight (Ml) of the (co)polymer (F) is not particularly limited as long as the weight average molecular weight (Ml) is smaller than that of the copolymer (A), but it is preferably 500 or more and 100,000 or less. It is more preferable that they are 800 or more and 80,000 or less, and, as for this weight average molecular weight, it is still more preferable that they are 1,000 or more and 50,000 or less. The (co)polymer (F) having a molecular weight in the above range contains structural units similar to those of the copolymer (A), but exists separately as an acrylic resin of low molecular component. Therefore, in the adhesive layer formed using the adhesive for optical films containing (co)polymer (F), it becomes possible for this (co)polymer (F) to move freely. It is excellent in that it becomes easy to provide stress relaxation property to an adhesive layer by this. Moreover, since the (co)polymer (F) is the same acrylic component as the copolymer (A), compatibility is good, and since it becomes difficult to produce an adhesive layer cloudy (preferably it becomes not cloudy), it is preferable.

In the adhesive for optical films which concerns on this invention, in a copolymer (A), the said component (a') may be contained, and unlike a copolymer (A), the said (co)polymer (F) may be contained.

In order to efficiently exhibit the effects of components (a') and (co)polymer (F), component (a') may be a constituent of the copolymer (A), and unlike the copolymer (A), the (co) ) may exist as polymer (F). In other words, the component (a1) to (a4) and component (a') contained in the copolymer (A) may be copolymerized. In addition, the copolymer by multistage polymerization (A) and component (a') may be superposed|polymerized, and unlike copolymer (A), (co)polymer (F) may be blended.

In the present invention, the structure of the (meth)acrylic monomer that can be used as the above component (a') or can be used in the (co)polymer (F) is not particularly limited.

Specifically as the (meth)acrylic monomer constituting the (co)polymer (F), for example, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, acryl Ronitrile, (meth)acrylamide, N-methylol (meth)acrylamide, dimethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, diethyl (meth)acrylamide, dimethylaminopropyl (meth) Acrylamide, diacetone (meth)acrylamide, acryloylmorpholine, 2-methacryloyloxyethylphthalic acid, tetrahydrofurfuryl (meth)acrylate, methyl (meth)acrylate, dicyclopentenyloxyethyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl-2-nitropropyl (meth) acrylate, n-butyl (meth) Acrylate, isobutyl (meth)acrylate, b-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth)acrylate, 2,2-dimethylbutyl (meth)acrylate, n-hexyl (meth)acrylate, cetyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate (meth)acrylic acid (C1-20) alkyl esters such as acrylate, 4-methyl-2-propylpentyl (meth)acrylate, N-octadecyl (meth)acrylate, and further, for example, cycloalkyl (meth) acrylate (eg, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, etc.), aralkyl (meth) acrylate (eg, benzyl (meth) acrylate, etc.), Cyclic (meth)acrylate (eg, 2-isobornyl (meth)acrylate, 2-norbornylmethyl (meth)acrylate, 5-norbornen-2-yl-methyl (meth)acrylate , 3-methyl-2-norbornylmethyl (meth)acrylate, etc.), hydroxyl group-containing (meth)acrylic acid esters (eg, hydroxyethyl (meth)acrylate, 2-ha Hydroxypropyl (meth)acrylate, 2,3-dihydroxypropylmethyl-butyl (meth)acrylate, etc.), (meth)acrylic acid esters containing an alkoxy group or phenoxy group (2-methoxyethyl (meth)acryl rate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethylcarbitol (meth)acrylate, phenoxyethyl ( meth)acrylate), epoxy group-containing (meth)acrylic acid esters (eg, glycidyl (meth)acrylate, etc.), halogen-containing (meth)acrylic acid esters (eg, 2,2,2- Trifluoroethyl (meth)acrylate, 2,2,2-trifluoroethylethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoro pentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, etc.), alkylaminoalkyl (meth)acrylate (for example, dimethylaminoethyl (meth)acrylate etc.), etc. are mentioned. These (meth)acrylic monomers can be used individually or in mixture of 2 or more types.

As the (co)polymer (F), an acrylic oligomer or an acrylic polymer can also be used. Specific examples of the acrylic oligomer include, for example, "ARU (Arupon) (registered trademark)" manufactured by Dong-A Synthetic Co., Ltd., "ACT FLOW (registered trademark)" manufactured by Soken Chemical Co., Ltd., BFA. Commercial products, such as "JAPAN CO., LTD." "CLARITY (Kuraretti)" (registered trademark), are mentioned.

Specific examples of (meth)acrylic monomers having a glass transition temperature of 50° C. or higher of a homopolymer that can be used as the component (a′) or can be used in the (co)polymer (F) are shown below. On the other hand, the parentheses indicate the glass transition temperature of the homopolymer.

Specific examples include isobornyl acrylate (94°C), dicyclopentenyl acrylate (120°C), dicyclopentanyl acrylate (120°C), acrylonitrile (97°C), acrylamide (165°C) , N-methylolacrylamide (150°C), dimethylacrylamide (119°C), N-isopropylacrylamide (134°C), diethylacrylamide (81°C), dimethylaminopropylacrylamide (134°C), Diacetoneacrylamide (77°C), acryloylmorpholine (145°C), 2-methacryloyloxyethyl phthalic acid (55°C), methyl methacrylate (105°C), ethyl methacrylate (65°C) , t-butyl methacrylate (107°C), cyclohexyl methacrylate (66°C), tetrahydrofurfuryl methacrylate (60°C), benzyl methacrylate (54°C), isobornyl methacrylate ( 180 degreeC), dicyclopentenyloxyethyl methacrylate (50 degreeC), dicyclopentanyl methacrylate (175 degreeC), etc. are mentioned. These may be used alone or in mixture of two or more.

The preferable content of the component (a') in the copolymer (A) (the amount of the (meth)acryl monomer having a glass transition temperature of 50° C. or higher of a homopolymer as a raw material monomer) is as follows. From the viewpoint of showing more efficiently, with respect to 100 mass % of the total amount of the structural units constituting the copolymer (A), preferably more than 0 mass % and 20 mass % or less. The content is more preferably 0.1 mass % or more and 15 It is mass % or less, and particularly preferably 0.5 mass % or more and 10 mass % or less The content of component (a') is 20 mass % or less, from the viewpoints that coexistence of suppression of dent and warpage becomes easier.

Preferably content of the (co)polymer (F) which concerns on this invention is 20 mass % or less with respect to 100 mass % of the total amount of adhesives for optical films from a viewpoint which shows the effect of this invention more efficiently. This content becomes like this. More preferably, they are 0.1 mass % or more and 15 mass % or less, Especially preferably, they are 0.5 mass % or more and 10 mass % or less. When content of (co)polymer (F) is 20 mass % or less, the advantage of being easy to suppress simultaneously a dent and a curvature, etc. can be acquired.

The glass transition temperature of the homopolymer may be 50° C. or higher, but from the viewpoint of making it easier to balance the suppression of dents and warping, the glass transition temperature is preferably 50° C. or higher and 200° C. or lower, and 50° C. or higher. 150 degrees C or less is more preferable, and 60 degrees C or more and 120 degrees C or less are still more preferable. The glass transition temperature is a value measured by differential scanning calorimetry of the homopolymer (homopolymer).

The above-mentioned copolymers (A) and (co)polymers (F) may be used alone or in combination of two or more.

[Method for producing (meth)acrylic acid ester copolymer (A)]

Next, the manufacturing method of a copolymer (A) is demonstrated. In the present invention, the method for producing the copolymer (A) is not particularly limited. Specifically, a conventionally known method such as a solution polymerization method using a polymerization initiator, a bulk polymerization method, an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, a thin film polymerization method, and a spray polymerization method can be used. Examples of the polymerization control method include an adiabatic polymerization method, a temperature-controlled polymerization method, and an isothermal polymerization method. As the polymerization initiator, either a thermal polymerization initiator or a photoinitiator may be used. In addition to or in addition to the method of initiating polymerization with a polymerization initiator, a method of initiating polymerization by irradiating active energy rays such as radiation, electron beams or ultraviolet rays can also be used. Among them, the solution polymerization method using a thermal polymerization initiator or the bulk polymerization method using a photoinitiator is more preferable because the molecular weight can be easily controlled and impurities can be reduced.

In the solution polymerization method using a thermal polymerization initiator, a thermal polymerization initiator is added to the monomer solution used as a raw material of a copolymer (A), for example, the raw material monomer solution which consists of the said monomer, and a polymerization reaction is performed. More specifically, ethyl acetate, toluene, methyl ethyl ketone, acetone, etc. are used as the solvent, and preferably 0.01 parts by mass or more and 1 part by mass or less of the thermal polymerization initiator is added with respect to 100 parts by mass of the total amount of the raw material monomers. Then, the method of making it react in nitrogen atmosphere, for example at the reaction temperature of 40 degreeC or more and 90 degrees C or less, and the reaction time of 3 hours or more and 10 hours or less is mentioned.

As the thermal polymerization initiator, for example, 2,2'-azobisisobutyronitrile (AIPN), 2,2'-azobis(2-methylbutyronitrile), azobiscyanovaleric acid, 2,2'- Azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis(2-methylpropio nate), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis[N-(2-) propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis[2-(2-imidazolin-2-yl) )propyne]dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane]disulfate dihydrate, 2,2'-azobis(2-methylpropionamidi Gin) dihydrochloride, 2,2'-azobis [N-(2-carboxyethyl)-2-methylpropionamidine] hydrate, 2,2'-azobis [2-(2-imidazoline-2) -yl)propane, 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane)dihydrochloride, 2,2'-azobis[2-methyl-N-(2-) azo compounds such as hydroxyethyl) propionamide]; t-butylperoxypivalate, t-butylperoxybenzoate, t-butylperoxy-2-ethylhexanoate, di-t-butylperoxide, cumene hydroperoxide, benzoylperoxide, t-butyl organic peroxides such as hydroperoxide; and inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate and sodium persulfate. These thermal polymerization initiators can be used individually or in mixture of 2 or more types.

As a block polymerization method using a photoinitiator, a raw material monomer and a photoinitiator are added, for example, The method of irradiating an active energy ray with the reaction initiation temperature of 20 degreeC or more and 35 degrees C or less in nitrogen atmosphere is mentioned. At a stage in which the temperature in the reaction system has risen from the reaction initiation temperature by 5°C or more and 15°C or less, the reaction is stopped by introducing air into the reaction system or the like to obtain a copolymer (A).

Examples of the active energy ray usable by the bulk polymerization method include ultraviolet rays, laser rays, α rays, β rays, γ rays, X rays, and electron beams. In view of the advantages of controllability and handleability, price, and the like, ultraviolet rays can be preferably used. More preferably, ultraviolet rays with a wavelength of 200 nm or more and 400 nm or less can be used. Ultraviolet rays can be irradiated using light sources, such as a high pressure mercury lamp, a microwave excitation lamp, a chemical lamp, and a black light. The illuminance is preferably 3.2 mW/m ² or more and 5.6 mW/m ² or less.

Examples of the photopolymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethyl ketal, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-(4-isopropylphenyl)-2- Hydroxy-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-hydroxy-2-methyl-1-one acetophenones such as phenylpropan-1-one; benzophenones including benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin ethers such as benzoin propyl ether and benzoin ethyl ether; thioxanthone such as 4-isopropyl thioxanthone; 1-hydroxycyclohexylphenyl ketone, xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, etc. are mentioned. These photoinitiators can be used individually or in mixture of 2 or more types.

As the photopolymerization initiator, a commercially available product may be used. Examples of commercially available products include, for example, IRGACURE (registered trademark) 184, 819, 907, 651, 1700, 1800, 819, 369, 261, DAROCURE (registered trademark) TPO, 1173 (above, BFA Japan Co., Ltd.), ESACURE (registered trademark) KIP150, TTV (above;藥) made by a joint stock company) and the like.

Preferably the usage-amount of a photoinitiator is 0.0005 mass part or more and 1 mass part or less with respect to 100 mass parts of total amounts of a raw material monomer. The usage-amount becomes more preferably 0.002 mass part or more and 0.5 mass part or less.

In addition, in order to control the molecular weight of the copolymer (A), a chain transfer agent may be used. Examples of the chain transfer agent include, for example, methyl mercaptan, t-butyl mercaptan, decyl mercaptan, benzyl mercaptan, stearyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, mercaptoacetic acid, mercapto. Mercaptans, such as propionic acid and its ester, 2-ethylhexyl thioglycol, and thioglycolic acid octyl; alcohols such as methanol, ethanol, propanol, n-butanol, isopropanol, t-butanol, hexanol, benzyl alcohol, and allyl alcohol; halogenated hydrocarbons such as chloroethane, fluoroethane and trichloroethylene; carbonyls such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, acetaldehyde, propionaldehyde, n-butylaldehyde, furfural, and benzaldehyde; methyl-4-cyclohexene-1,2-dicarboxylic anhydride, α-methyl styrene, and the like. These chain transfer agents can be used individually or in mixture of 2 or more types.

On the other hand, the production method in the case of synthesizing the (co)polymer (F) is the same as the production method of the copolymer (A), except for changing the type and content of the monomer, the amount of the polymerization initiator used, and the like.

<Crosslinking agent (B)>

It is preferable that the adhesive for optical films of this invention contains a crosslinking agent (B). The crosslinking agent (B) reacts with the (meth)acrylic acid ester copolymer (A) to form a crosslinked structure. Therefore, in the adhesive for optical films, it can mainly contribute to adhesiveness (adhesiveness) and durability.

In the present invention, the crosslinking agent (B) preferably contains at least one selected from the group consisting of an isocyanate compound, a carbodiimide compound, an oxazoline compound, an epoxy compound, a polyfunctional (meth)acrylic acid ester monomer, and a peroxide. Below, these various crosslinking agents are demonstrated.

[isocyanate compound]

Specific examples of the isocyanate compound that can be used as the crosslinking agent (B) in the present invention include, for example, dimer acid diisocyanate, 2,4-toluene diisocyanate (2,4-TDT), 2,6-toluene diisocyanate (2, 6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDA), 1,4-phenylenediisocyanate , xylylene diisocyanate (XDS), tetramethylxylidene diisocyanate (TDX), toluidine diisocyanate (TDD), 1,5-naphthalene diisocyanate (L), such as aromatic diisocyanates; aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TDMD), lysine diisocyanate, and methyl norbornane diisocyanate (NHD); alicyclic diisocyanates such as transcyclohexane 1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDRA (hydrogenated XDA), and H12-MDI isocyanate; carbodiimide-modified diisocyanates of the above diisocyanates; Or these isocyanurate-modified diisocyanates, etc. are mentioned. An adduct of the isocyanate compound and a polyol compound such as trimethylolpropane, polytetramethylene ether glycol (PMTG), and polypropylene glycol (PG), and a biuret or isocyanurate form of these isocyanate compounds are also preferably used. can

A commercially available product may be used for these isocyanate compounds, and a synthetic substance may be used for it.

Commercially available products include, for example, CORONATE (registered trademark) L, Coronate (registered trademark) HL, Coronate (registered trademark) HX, Coronate (registered trademark) 2030, Coronate (registered trademark) 2031 (or above) , Toso Corporation), TAKANATE (registered trademark) D-102, Takenate (registered trademark) D-110N, Takenate (registered trademark) D-200, Takenate (registered trademark) D-202 ( Above, Mitsui Chemical Co., Ltd.), DURANATE (registered trademark) 24A-100, Duranate (registered trademark) TPA-100, Duranate (registered trademark) TPA-100, Duranate (registered trademark) ) P301-75E, Duranate (registered trademark) E402-90T, Duranate (registered trademark) E405-80T, Duranate (registered trademark) TS-100, Duranate (registered trademark) D-101, Duranate (registered trademark) ) D-201 (above, manufactured by Asahi Kasei Co., Ltd.), SMIDULE (registered trademark) N-75, N-3200, N-3300 (above, manufactured by Kovestro Urethane Co., Ltd.) , SANPRENE (registered trademark) P-6090 (PDT/MDD), Sanprene (registered trademark) P-663L (PDT/TDD), Sanprene (registered trademark) P-664 (DTD) ), Sanpren (registered trademark) P-665 (PDMT/TDD), Sanpren (registered trademark) P-667 (PDMT/TDD), Sanpren (registered trademark) P-868 (PDT), TD/T Sanpren (registered trademark) P-870 (PMG/HMDD), Sanpren (registered trademark) C-810” (PG/TDD) (above, manufactured by Sanyo Chemical Industry Co., Ltd.) can, but is not limited to these.

The isocyanate compound may be used in the form of an unblocked isocyanate compound.

In addition, it may be used in the form of a block isocyanate compound obtainable by reacting with a blocking agent that protects an isocyanate group. As such a block isocyanate compound, a commercially available product may be sufficient and a synthetic substance may be sufficient. As a commercial product of a block isocyanate compound, For example, Asahi Kasei Co., Ltd. DURANATE (trademark) MFM-B60X (block 1,6-hexamethylene diisocyanate), Duranate (trademark) MFM -K60X (block 1,6-hexamethylene diisocyanate), CORONATE (registered trademark) manufactured by Tosoh Corporation APA-M, 2503, 2507, 2513, 2515, MIRIONATE (registered trademark) MS-50, Mitsui Chemicals Co., Ltd. TAKANATE (registered trademark) B-830 (block toluene diisocyanate), B-815N (block 4,4'-methylenebis (cyclohexyl isocyanate)) , B-842N (block 1,3-bis (isocyanate methyl) cyclohexane), B-846N (block 1,3-bis (isocyanate methyl) cyclohexane), B-874N (block isophorone diisocyanate), B-882N (block 1,6-hexamethylene diisocyanate), D-C Co., Ltd. BAR KNOCK (registered trademark) D-500 (block toluene diisocyanate), D-550 (block 1,6-hexa Methylene diisocyanate), Daiichi Kogyo Pharmaceutical Co., Ltd. ELASTRON (registered trademark) BN-P17 (Block 4,4'-diphenylmethane diisocyanate), BN-04, BNM -08, BN-44, BN-45 (above, blocked urethane modified polyhydric isocyanate), etc. are mentioned. Among these, Duranate (trademark) MFM-K60X is preferable.

On the other hand, from the viewpoint of further improving the durability of the pressure-sensitive adhesive, the isocyanate compound is preferably used in the form of an isocyanate compound that is not blocked.

Moreover, it is preferable that the isocyanate compound which concerns on this invention has a number average molecular weight (Mn) of 900 or more and 10,000 or less. By including the isocyanate compound having such a number average molecular weight as the crosslinking agent (B), while suppressing the density of the crosslinked structure of the copolymer (A), a gentle crosslinking effect due to the long distance between the crosslinking points can be expressed. have. Thereby, coexistence of suppression of the bubble in an edge part, and suppression of peeling can be achieved more efficiently.

In other words, according to a more preferred embodiment of the present invention, the crosslinking agent (B) contains an isocyanate compound (however, a blocked isocyanate compound is excluded) having a number average molecular weight (Mn) of 900 or more and 10,000 or less.

From a viewpoint of exhibiting the effect of this invention further, it is more preferable that the number average molecular weights (Mn) of an isocyanate compound are 900 or more and 7,000 or less. As for the said number average molecular weight (Mn), it is more preferable that they are 1,000 or more and 5,000 or less. In addition, the number average molecular weight (Mn) of an isocyanate compound can be calculated|required by the method similar to the measuring method of the weight average molecular weight of the copolymer (A) shown in an Example.

[Carbodiimide Compound]

In the present invention, the carbodiimide compound that can be used as the crosslinking agent (B) is not particularly limited. To give one example, a high molecular weight polycarbodiimide produced by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst is used.

Examples of the diisocyanate used in the decarboxylation condensation reaction include 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, and 3,3'-dimethyl -4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-toluene diisocyanate, 2 and 6-toluene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tetramethylxylidene diisocyanate, and the like.

Moreover, as a carbodiimidation catalyst which can be used for the said decarboxylation condensation reaction, 1-phenyl-2-phosphorene-1-oxide, 3-methyl-2-phosphorene-1-oxide, 1- and phosphorene oxides such as ethyl-3-methyl-2-phosphorene-1-oxide, 1-ethyl-2-phosphorene-1-oxide, and 3-phosphoene isomers thereof.

As the high molecular weight polycarbodiimide, a commercially available product or a synthetic material may be used. As a commercial product, the CARBODILITE (trademark) series made by Nisshinbo Chemical Co., Ltd. is mentioned, for example. Among them, Carbodilite (registered trademark) V-01, V-03, V-05, V-07, and V-09 are preferred because of their excellent compatibility with organic solvents.

[Oxazoline Compound]

The oxazoline compound which can be used as a crosslinking agent (B) in this invention is not restrict|limited in particular.

However, an oxazoline group-containing acryl/styrene-based polymer comprising a main chain composed of an acrylic skeleton or a styrene skeleton and having an oxazoline group in the side chain of the main chain is preferable. Moreover, oxazoline group containing polymers, such as an oxazoline group containing acrylic polymer which contains the main chain which consists of acryl skeleton, and has an oxazoline group in the side chain of the main chain, are also preferable.

As an oxazoline group, 2-oxazoline group, 3-oxazoline group, 4-oxazoline group etc. are mentioned, for example, Especially, 2-oxazoline group is preferable.

Moreover, the said oxazoline group containing polymer may have a polyoxyalkylene group other than an oxazoline group.

Specific examples of the oxazoline group-containing polymer include EPOCROS (registered trademark) WS-300 manufactured by Nippon Shokubai Co., Ltd., EPOCROS (registered trademark) WS-500, and EPOCROS (registered trademark). ) Oxazoline group-containing acrylic polymers such as WS-700, oxazolines such as Epocross (registered trademark) K-1000 series and Epocross (registered trademark) K-2000 series manufactured by Nihon Shokubai Co., Ltd. and group-containing acryl/styrene-based polymers.

[epoxy compound]

The epoxy compound which can be used as a crosslinking agent (B) in this invention is not restrict|limited in particular, A well-known epoxy type crosslinking agent can be used suitably. As commercially available products of the epoxy compound, for example, Mitsubishi Gas Chemical Co., Ltd.'s "TELD (registered trademark)-C", "TELDRA (registered trademark)-X", liquid epoxy resins such as ADEKARESIN (registered trademark) PE series”, “ADEKARESIN (registered trademark) PE series”, and “CELLOXIDE (registered trademark)” manufactured by Daicel Corporation. These liquid epoxy resins are preferable at the point from which mixing operation at the time of manufacturing the adhesive for optical films becomes easy.

[Polyfunctional (meth)acrylic acid ester monomer]

The polyfunctional (meth)acrylic acid ester monomer is a (meth)acrylic acid ester monomer having a plurality of radically polymerizable functional groups. Such a compound can also be used as a crosslinking agent (B).

As a polyfunctional (meth)acrylic acid ester monomer, the polyfunctional monomer of a hydrocarbon type or hydrocarbon ether type is mentioned, for example. The hydrocarbon-based or hydrocarbon ether-based polyfunctional monomer is a compound obtained by (meth)acrylated hydroxyl group of a polyhydric alcohol having a hydrocarbon group or hydrocarbon ether group having 10 or more carbon atoms or a hydrocarbon ether group as a main skeleton. This compound is preferable from the viewpoint of improving the adhesiveness by crosslinking. Examples of the hydrocarbon group of the polyhydric alcohol include a straight-chain or branched-chain aliphatic hydrocarbon group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and a hydrocarbon group in which these hydrocarbon groups are combined. Examples of the hydrocarbon ether group include those obtained by etherification of the hydrocarbon group. Further, examples of the polyhydric alcohol having a hydrocarbon ether group as the main skeleton include compounds obtained by adding an alkylene oxide having 2 or more and 4 or less carbon atoms to the polyhydric alcohol (addition number of 1 or more and 30 or less). Furthermore, polyalkylene glycol (addition number of 1 or more and 30 or less) etc. which can be obtained by C2 or more and 4 or less alkylene oxide are mentioned.

Specific examples of the hydrocarbon-based bifunctional monomer include, for example, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. di(meth)acrylates of alkylene glycols such as acrylate and neopentyl glycol di(meth)acrylate; di(meth)acrylate of a diol compound having an alicyclic hydrocarbon group such as cyclohexanedimethanol di(meth)acrylate and tricyclodecanedimethanol di(meth)acrylate; The di(meth)acrylate of the diol compound which has aromatic hydrocarbon groups, such as bisphenol A di(meth)acrylate, etc. are mentioned.

In addition, as a specific example of a hydrocarbon ether type bifunctional monomer, for example, alkoxylated hexanediol di(meth)acrylate, alkoxylated cyclohexanedimethanol di(meth)acrylate, alkoxylated di(meth)acrylate, alkoxy A difunctional compound obtained by adding an alkylene oxide to an alkylene glycol or diol compound based on the above hydrocarbon-based bifunctional monomer such as neopentyl glycol di(meth)acrylate and alkoxylated bisphenol A di(meth)acrylate (meth)acrylate etc. are mentioned. In addition, specific examples of the hydrocarbon ether-based bifunctional monomer include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acryl. and di(meth)acrylates and dioxane glycol di(meth)acrylates of polyalkylene glycols such as rate, tripropylene glycol di(meth)acrylate, and dipropylene glycol di(meth)acrylate.

In addition, as a hydrocarbon type or hydrocarbon ether type trifunctional monomer or a tetrafunctional monomer, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glyceryl tri(meth)acryl tri(meth)acrylate or tetra(meth)acrylate of a tri or tetraol compound such as acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane tetra(meth)acrylate, or the tri or tetraol compound and tri(meth)acrylate or tetra(meth)acrylate of a compound to which alkylene oxide of is added.

Moreover, polyester poly(meth)acrylate, epoxy (meth)acrylate, etc. which have two or more (meth)acryloyl groups at the terminal as a monomer other than the said hydrocarbon type or hydrocarbon ether type are mentioned.

〔peroxide〕

The peroxide which can be used as a crosslinking agent (B) in this invention is not specifically limited, A well-known substance can be used. Moreover, as a peroxide, it is preferable that the half-life temperature for 1 minute is 80 degreeC or more and 160 degrees C or less in consideration of productivity and stability. It is more preferable that 1 minute half-life temperature is 80 degreeC or more and 140 degrees C or less. More preferably, they are 80 degreeC or more and 125 degrees C or less, Especially preferably, they are 90 degrees C or more and 125 degrees C or less. On the other hand, "half-life of peroxide" is an index indicating the decomposition rate of peroxide, and means the time until the residual amount of peroxide is halved. The decomposition temperature for obtaining a half-life at a certain time and the half-life time at a certain temperature are described in the manufacturer's catalog or the like. For example, it is described in the organic peroxide catalog ninth edition (May 2003) issued by Ilyu Co., Ltd.

Examples of such peroxides include, for example, diisopropyl peroxydicarbonate (1 minute half-life temperature of 88.3°C, hereinafter, the temperature in parentheses indicates the 1-minute half-life temperature), di(2-ethylhexyl)peroxydicarbonate (90.6°C), Bis(4-t-butylcyclohexyl)peroxydicarbonate (92.1°C), di-sec-butylperoxydicarbonate (92.4°C), t-butylperoxyneodecanoate (103.5°C), t-hexylperoxy Pivalate (109.1°C), t-butylperoxypivalate (110.3°C), dilauroyl peroxide (116.4°C), bis-n-octanoyl peroxide (117.4°C), 1,1,3,3 -tetramethylbutylperoxy-2-ethylhexanoate (124.3 ℃), di (4-methylbenzoyl) peroxide (128.2 ℃), dibenzoyl peroxide (benzoyl peroxide) (130.0 ℃), dibenzoyl peroxide a mixture of benzoyl m-methylbenzoyl peroxide and m-toluyl peroxide (131.1° C.), t-butylperoxybutyrate (136.1° C.), and the like. Among them, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, and t-butylperoxyneodecanoate can be preferably used. These may be used alone, but it is also preferable to use two or more in combination from the viewpoint of controlling the reactivity. As an example of using 2 or more types together, the combination of di(4-t- butylcyclohexyl)peroxydicarbonate and dilauroyl peroxide is preferable.

As the peroxide, a commercially available product or a synthetic product may be used. Commercially available products include, for example, Ilyu Co., Ltd. brand names: "PAROIL (registered trademark, hereinafter the same) IB" (85.1°C), "PARK MILL (registered trademark, hereinafter the same) ND" (94.0) ℃), 「Paroyl NPD」 (94.0℃), 「Faroyl IPA」 (88.3℃), 「Paroyl SPB」 (92.4℃), 「PEROCTA (registered trademark, hereinafter the same) ND」 (92.4℃) ℃), 「Paroyl TPD」 (92.1°C), 「Faroyl OPD」 (90.6°C), 「PERHEXYL (registered trademark, hereinafter the same) ND」 (100.9°C), “PERBUTYL (PERBUTYL) ( Registered trademark, hereinafter the same) ND” (103.5°C), “Perbutyl NHP” (104.6°C), “Perhexyl PV” (109.1°C), “Perbutyl PV” (110.3°C), “Pharoyl 355” (112.6 ℃), 「Paroyl L」 (116.4℃), 「Perota O」 (124.3℃), 「Paroyl SIA」 (131.8℃), 「PERHEXA (registered trademark, hereinafter the same) 25O」 (118.8 ℃), 「Perhexyl O」 (132.6℃), 「NYPER (registered trademark, hereinafter the same) PBM」 (128.2℃), 「Perbutyl O」 (134.0℃), 「Nypar BMT」 (131.1 ℃), 「Naipa BMT」 (130.0℃), 「Naipa BMT-K40」 (131.1℃), 「Naipa BMT-M」 (131.1℃), 「Perhexa MMC」 (142.1℃), 「Perhexa TDM” (147.1°C), “Pahexa HCP” (149.2°C), “Perhexa C” (153.8°C), “PERTETRA (registered trademark, hereinafter the same) A” (153.8°C), “Perhexyl I” (155.0℃), “Perbutyl L” (159.4℃), “Perbutyl I” (158.8℃), “Perhexa 25Z” (158.2℃), “Perbutyl A” (159.9℃), “Perhexa 22" (159.9 degreeC) etc. are mentioned.

In this invention, a crosslinking agent (B) may be used individually by 1 type, and may be used in combination of 2 or more type. When combining 2 or more types, you may combine 2 or more types (for example, 2 types of isocyanate compounds) of the crosslinking agent of the same series. You may combine 1 or more types of crosslinking agents of different types, respectively (for example, 1 type of isocyanate compound and 1 type of peroxide).

Although content in particular of a crosslinking agent (B) is not restrict|limited in the adhesive for optical films of this invention, It is preferable that they are 0.001 mass parts or more and 20 mass parts or less with respect to 100 mass parts of copolymers (A). As for this content, it is more preferable that they are 0.01 mass part or more and 10 mass parts or less, It is still more preferable that they are 0.03 mass parts or more and 5 mass parts or less. Especially preferably, they are 0.05 mass part or more and 3 mass parts or less. When content of a crosslinking agent (B) is 0.001 mass part or more, it is preferable from a viewpoint that foaming can be suppressed at the time of heat durability. Moreover, it is preferable from a viewpoint that generation|occurrence|production of a dent can be suppressed. On the other hand, if content is 20 mass parts or less, a crosslinked structure does not become dense, but it is preferable from a viewpoint that durability can be ensured also in a harsh environment.

<Silane coupling agent (C)>

It is preferable that the adhesive for optical films of this invention further contains a silane coupling agent. A silane coupling agent (C) can contribute mainly to the improvement of durability in the adhesive for optical films, and the adhesive improvement with glass in the case where a to-be-adhered body is glass. In addition, in this specification, "silane coupling agent" means a silane compound which does not have a siloxane bond (Sio-O-Sb bond), and has two or more reactive groups in a molecule|numerator.

Although the silane coupling agent (C) in particular in this invention is not restrict|limited, Specifically, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxy propyl triethoxysilane, methyl trimethoxysilane, dimethyl dime Toxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane, n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxy Silane, phenyltrimethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropyltriethoxy silane, γ-acryloyloxypropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ -Chloropropyl trimethoxysilane, (gamma)-mercaptopropyl trimethoxysilane, (gamma)-mercaptopropylmethyldimethoxysilane, etc. are mentioned. In addition, a silane coupling agent having a functional group such as an epoxy group (glycidoxy group), an amino group, a mercapto group, and a (meth)acryloyl group, and a silane coupling agent containing a functional group having reactivity with these functional groups are mentioned. Moreover, the compound which has a hydrolysable silyl group obtained by making another coupling agent, polyisocyanate, etc. react in arbitrary ratios with respect to each functional group can also be used.

A commercially available product may be used for the said silane coupling agent (E), and a synthetic product may be used for it. As a commercially available product of the silane coupling agent (E), for example, KBM-303, KBM-403, KBM-402, MBM-403, MBM-502, M-5103, MBM-503, MBM-503. , KBM-803, KBM-846, KBM-9007 (above, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) and the like.

The silane coupling agent (C) may be used alone or in combination of two or more.

Content in particular of a silane coupling agent (C) in case the adhesive for optical films of this invention contains a silane coupling agent (C) is not restrict|limited. However, it is preferable that they are 0.001 mass part or more and 10 mass parts or less with respect to 100 mass parts of copolymers (A). As for this content, it is more preferable that they are 0.001 mass part or more and 5 mass parts or less, It is still more preferable that they are 0.01 mass part or more and 3 mass parts or less. It is preferable from a viewpoint that the effect with respect to durability can be expressed that content is 0.001 mass part or more even if it sets in a harsh environment. On the other hand, if content is 10 mass parts or less, it is preferable from a viewpoint that the deterioration of the thermal foam derived from a low molecular-weight compound will disappear.

<Silicate oligomer (D)>

The pressure-sensitive adhesive for an optical film of the present invention preferably further comprises a silicate oligomer (D). The silicate oligomer (D) can mainly contribute to the improvement of rework property in the adhesive for optical films.

The silicate oligomer (D) according to the present invention has a structure represented by the following formula (4)

[Formula 4]

In Formula 4, R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 or more and 20 or less carbon atoms, or a phenyl group. n is an integer of 1 or more and 100 or less, and it is preferable that it is an integer of 2 or more and 100 or less. The related alkyl group and phenyl group may be substituted and may not be substituted. In addition, a linear structure may be sufficient as an alkyl group, and a branched structure may be sufficient as it.

In the present invention, a methylsilicate oligomer in which all of R ¹ , R ² , X ¹ , and X ² in the general formula (4) are methyl groups is preferable from the viewpoint of compatibility of durability and reworkability. On the other hand, the silicate oligomer (D) may be used alone or in mixture of two or more.

In the present invention, the weight average molecular weight of the silicate oligomer (D) is not particularly limited. However, Preferably they are 300 or more and 30000 or less, More preferably, they are 500 or more and 25000 or less, More preferably, they are 600 or more and 5000 or less, Especially preferably, they are 600 or more and 5000 or less. It is preferable from a viewpoint of being easy to ensure rework property as a weight average molecular weight is 300 or more. On the other hand, if it is 30000 or less, it is preferable from a viewpoint of being easy to ensure durability. In addition, the weight average molecular weight of a silicate oligomer (D) can be measured by the method similar to the measuring method of the weight average molecular weight of the copolymer (A) shown in an Example.

When the pressure-sensitive adhesive for an optical film of the present invention contains the silicate oligomer (D), the content of the silicate oligomer (D) is not particularly limited. However, it is preferable that they are 0.01 mass part or more and 50 mass parts or less with respect to 100 mass parts of copolymer (A). As for this content, it is more preferable that they are 0.3 mass parts or more and 10 mass parts or less, and it is still more preferable that they are 0.5 mass parts or more and 5 mass parts or less. When content is 0.01 mass part or more, it is preferable at the point which the effect with respect to durability is expressed even if it sets in a harsh environment. On the other hand, when content is 50 mass parts or less, it is preferable at the point which becomes easy to make rework property and durability compatible.

<High softening point resin (E)>

It is preferable that the adhesive for optical films of the present invention further contains a high softening point resin (E) having a softening point of 60° C. or more and 200° C. or less (hereinafter, also simply referred to as “high softening point resin (E)”). By adding the high softening point resin (E), it is possible to provide an adhesive having a characteristic of being hard to some extent at room temperature and softening (softening) at a high temperature. By adding the high softening point resin (E) to have the corresponding properties, it is possible to harden at room temperature and effectively suppress the occurrence of dents. Moreover, since it softens at high temperature, it is set in a high-temperature (for example, 85 degreeC) environment, it can have stress relaxation property, and it is preferable at the point which can suppress generation|occurrence|production of curvature effectively.

The high softening point resin (E) that can be used in the present invention is preferably a resin having a softening point of 60°C or more and 200°C or less from the viewpoint of being able to effectively exhibit the above-described effects. Therefore, conventionally known materials can be used. Specific examples thereof include, for example, aliphatic petroleum resins, alicyclic hydrocarbon resins, aromatic petroleum resins, fully hydrogenated aliphatic petroleum resins, fully hydrogenated alicyclic hydrocarbon resins, fully hydrogenated aromatic petroleum resins, and partially hydrogenated aliphatic petroleum resins. , partially hydrogenated alicyclic hydrocarbon resins, partially hydrogenated aromatic petroleum resins, etc. petroleum resins, aromatic hydrocarbon resins, aliphatic saturated hydrocarbon resins, terpene resins, terpene phenol resins, hydrogenated terpene resins, coumarone-indene resins, rosin acid, polymerization Rosin-based resins (also referred to as rosins or rosin derivatives) such as rosin acid and rosin ester-based resins (rosin acid esters), epoxy resins, phenol resins, oil (oil) soluble phenol resins, or modified resins thereof, etc. are preferably used. can be heard These high softening point resin (E) may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, from a viewpoint that compatibility with a copolymer (A) is favorable, an alicyclic hydrocarbon resin, a terpene phenol resin, and a terpene resin are more preferable. In addition, the high softening point resin (E) is more preferably a rosin ester-based resin from the viewpoint that compatibility with other components of the pressure-sensitive adhesive is very good and transparency can be easily obtained when applied to an optical film.

As the high softening point resin (E), a synthetic product may be used or a commercially available product may be used.

Examples of commercially available products of rosin ester-based resins include, for example, PIINECRYSTAL (registered trademark, the same) KRS-85 (softening point 80-87° C., the temperature in parentheses below indicates the softening point), Fine Crystal K-612 (80-90℃), Fine Crystal K-614 (84-94 degrees), Fine Crystal KE-100 (95-105℃), Fine Crystal KE-311 (90-100℃), Fine Crystal P-590 (90 -100℃), Fine Crystal KE-359 (94-104℃), Fine Crystal KE-604 (124-134℃), Fine Crystal KY-120 (110-130℃), Fine Crystal KY-140 (130-150) ℃), Fine Crystal KS-614 (84-94℃), Fine Crystal D-6011 (84-99℃), Fine Crystal KS-50M (145-160℃) (Above, Arakawa Chemical Industry Co., Ltd.) company) and the like. These are light pale color rosins, and are preferably used in optical applications requiring transparency.

In addition, as other examples of commercial products of rosin ester-based resins, Super ESTER A-75 (70-80° C.), Super Ester A-100 (95-105° C.), Super Ester A-115 (108-120° C.) ), Super Ester A-125 (120-130℃), TAMANOL (registered trademark, hereinafter the same) 460 (182-192℃) (above, manufactured by Arakawa Chemical Industry Co., Ltd.), etc. can be heard

Examples of commercial products of alicyclic hydrocarbon resins include, for example, ARCON (registered trademark, hereinafter the same) P-90 (85-95° C.), ARCON P-100 (95-105° C.), and ARCON (registered trademark). P-115(110-120℃), ARCON P-125(120-130℃), ARCON P-140(135-145℃), ARCON M-90(85-95℃), ARCON M-100(95- 105°C), Arcon M-115 (110-120°C), and Arcon M-135 (130-140°C) (all manufactured by Arakawa Chemical Industries, Ltd.) and the like.

As an example of a commercial product of a terpene phenol resin, For example, TAMANOL 803L (145-160 degreeC), Tamanol 901 (125-135 degreeC) (above, Arakawa Chemical Industry Co., Ltd. make), POLYSTER (registered trademark, hereinafter the same) U130 (125-135℃), YS Polystar U115 (110-120℃), YS Polystar T160 (155-165℃), YS Polystar T145 (140- 150℃), YS FORISTA T130 (125-135℃), YS FORISTA T115 (110-120℃), YS FORISTA T100 (95-105℃), YS FORISTA T80 (75-85℃), YPS Star S145 (140-150℃), YS Forister G150 (145-155℃), YS Forister G125 (120-130℃), YS Forister N125 (120-130℃), YS Forister K125 (120-130) deg.

Examples of commercially available terpene resins include, for example, SOS resin (RESIN) (registered trademark, hereinafter the same) PX1250 (120-130°C), SOS resin P1150 (110-120°C), SOS resin PX1000 (95-105°C) , X-resin PX800(75-85℃), X-resin PX1150N (110-120℃), SOS-resin O125(120-130℃), SOS-resin TOS105(110-120℃) , and X-resin T-85 (80-90°C) (above, manufactured by Yasuhara Chemical Co., Ltd.); and the like.

When the high softening point resin (E) is added to the pressure-sensitive adhesive for an optical film of the present invention, the amount of the high softening point resin (E) added is not particularly limited. However, it is preferable that they are 0.1 mass part or more and 30 mass parts or less with respect to 100 mass parts of copolymer (A). It is more preferable that they are 0.5 mass part or more and 25 mass parts or less, and, as for this addition amount, it is still more preferable that they are 1 mass part or more and 20 mass parts or less. It is preferable from a viewpoint that the effect of softening comes out at the time of a durability test that content is 0.1 mass part or more. Moreover, it is preferable from a viewpoint that generation|occurrence|production of curvature can be suppressed. On the other hand, if content is 30 mass parts or less, it is preferable from a viewpoint that durability deterioration by a low molecular weight substance can be suppressed. Moreover, it is preferable from a viewpoint that durability can be ensured also in harsh environments, such as being able to suppress effectively the fall of the flexibility of an adhesive even in a low temperature range, such as -25 degreeC or less.

The softening point of the high softening point resin (E) is preferably 60°C or more and 200°C or less. From a viewpoint of the improvement of adhesiveness, durability, and rework property, and suppression of generation|occurrence|production of a curvature and a dent, 70 degreeC or more and 150 degrees C or less are more preferable. The softening point is more preferably 80°C or more and 140°C or less, and particularly preferably 85°C or more and 130°C or less. In addition, in this invention, the said softening point shall use the value measured by the method described in IAS K6863 (1994).

<Other additional ingredients>

The pressure-sensitive adhesive for optical film of the present invention is known as a solvent, crosslinking accelerator, anti-aging agent, filler, colorant (pigment or dye, etc.), ultraviolet absorber, antioxidant, chain transfer agent, plasticizer, softener, surfactant, antistatic agent, etc., if necessary. You may contain the additive component (other additive component) within the range which does not impair the effect of this invention.

<solvent>

The adhesive for optical films of this invention may contain a solvent. By including a solvent, the effect of the significant improvement of productivity at the time of apply|coating can be acquired. Although it does not restrict|limit especially as a solvent, Esters, such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; Organic solvents, such as ketones, such as methyl ethyl ketone, methyl isobutyl ketone, and acetone, are mentioned. These solvents can be used individually or in mixture of 2 or more types.

<Manufacturing method of adhesive for optical film>

When the adhesive for optical films according to the present invention contains components other than the copolymer (A) and the copolymer (A), it can be produced by mixing each component. Meanwhile, the mixing order or mixing temperature of each component is not particularly limited, and may be appropriately adjusted by those skilled in the art.

[purpose]

The adhesive for an optical film of the present invention described above is suitable for various uses. For example, it can be preferably used for optical members such as an optical film, and in particular, can be preferably used for a thin pressure-sensitive adhesive optical film used in recent large-scale liquid crystal panels. Examples of such an optical film include an optical compensation film such as a polarizing plate, a retardation plate for preventing coloring, a viewing angle magnifying film for improving the viewing angle of a liquid crystal monitor, a luminance enhancing film for increasing the contrast of a display, and those laminated thereon can

In the present invention, the form of the pressure-sensitive adhesive layer formed by the above-described pressure-sensitive adhesive for an optical film, the form of the optical member in which the pressure-sensitive adhesive layer is formed on an optical film, etc., the optical film is a polarizing plate, or the optical member is a liquid crystal display device, organic It also provides a form applied to an image display device such as an LED display device, a flat panel display (PDP), a micro LED display, a curved display device, or a flexible display device. Hereinafter, each is demonstrated.

<Adhesive layer>

According to one aspect of the present invention, the pressure-sensitive adhesive layer for optical films formed from the above-described pressure-sensitive adhesive for optical films of the present invention is provided.

A person skilled in the art can set the thickness (film thickness after drying) of the adhesive layer of this invention suitably according to the use. The thickness is preferably 1 µm or more and 200 µm or less, and more preferably 3 µm or more and 75 µm or less. More preferably, they are 5 micrometers or more and 40 micrometers or less, Especially preferably, they are 7 micrometers or more and 35 micrometers or less, Most preferably, they are 10 micrometers or more and 30 micrometers or less. The thickness is preferably within the above range from the viewpoint that a good balance between durability and adhesive properties is obtained.

Although the gel fraction in particular immediately after drying of the adhesive layer of this invention is not restrict|limited, From a viewpoint of performing a punching process or a slit process, it is preferable that it is 95 % or less. Moreover, it is preferable that it is 40 % or more from a viewpoint of not requiring an aging process because there is no concern about the dent, curvature, and durability in the adhesive layer immediately after drying. As for this gel fraction, it is more preferable that it is 65 % or more. The gel fraction can be adjusted by controlling the amount of crosslinking agent or the amount of peroxide.

In the pressure-sensitive adhesive layer of the present invention, the difference between the initial adhesive force and the adhesive force after heating at 50° C. for 48 hours (adhesion after heating) may be 2.0N/25mm or less, specifically 0N/25mm to 2.0N/25mm. Within the above range, it is possible to ensure reworkability after long-term stationary and ensure heating durability. The initial adhesive force of the pressure-sensitive adhesive layer of the present invention may be 3.5N/25mm or less, for example, 0.1 to 3.5N/25mm, and the adhesive force after heating is 5.0N/25mm or less, for example 0.1 to 5.0N/25mm. The initial adhesive force and the adhesive force after heating may be measured by the method measured in the following experimental examples.

[Method for producing pressure-sensitive adhesive layer]

According to another aspect of the present invention, there is also provided a method for producing a pressure-sensitive adhesive layer for an optical film, which includes applying the above-described pressure-sensitive adhesive for an optical film of the present invention on a release sheet subjected to a peeling treatment, and then heat-treating it for crosslinking reaction.

When using an adhesive for an optical film, you may apply|coat an adhesive directly on an optical film, and may form an adhesive layer. However, it is preferable to apply the pressure-sensitive adhesive on a film having releasability to form a pressure-sensitive adhesive layer, and then transfer it to various optical films for use. Moreover, the film which has releasability with an adhesive layer manufactured in this way can also be wound together in a manufacturing process and it can be made into roll shape. If necessary, it can be cut or processed, and when adhering to various optical films, liquid crystal panels, etc., the film having the releasability can be removed and used. In addition, the film having releasability until the pressure-sensitive adhesive layer is put to practical use may also serve to protect the pressure-sensitive adhesive layer. In this specification, the film which has such a release property is also called a release sheet (separator).

As a constituent material of the release sheet, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, polyester film, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foil, laminates thereof, etc. and suitable thin leaflets of Since it is excellent in surface smoothness, a plastic film can be used preferably.

Moreover, the thickness of a release sheet is 5 micrometers or more and 200 micrometers or less normally, Preferably they are about 5 micrometers or more and 100 micrometers or less.

If necessary, the release sheet includes a silicone-based, fluorine-based, long-chain alkyl- or fatty acid amide-based release agent, a release treatment and antifouling treatment with silica powder, etc. Further processing can be performed. In particular, from the viewpoint of improving the peelability of the pressure-sensitive adhesive layer, it is preferable to perform peeling treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the release sheet.

In this invention, it does not restrict|limit especially as a coating method at the time of apply|coating the adhesive for optical films of this invention on the release sheet which carried out the peeling process, Various well-known methods can be used. For example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, extrusion coating method using a die coater, etc. and the like.

In the manufacturing method of the adhesive layer of this invention, the process of heat-processing after apply|coating the adhesive for optical films mentioned above on a release sheet is performed. The related heat treatment process not only dries and removes the solvent in the coating film obtained by application|coating, but also performs the objective of crosslinking reaction the adhesive for optical films mentioned above. The temperature of the heat treatment is preferably 40°C or more and 150°C or less, more preferably 50°C or more and 130°C or less, and still more preferably 80°C or more and 120°C or less. By making the temperature of heat processing into the said range, the adhesive layer which has outstanding adhesive properties can be obtained.

Moreover, although the time of heat processing can be set suitably, Preferably it is 5 second or more and 20 minutes or less, More preferably, it is 5 second or more and 10 minutes or less, More preferably, it is 10 second or more and 5 minutes or less.

In addition, it does not restrict|limit especially as a means of heat processing, Various well-known methods can be used. For example, a parallel drying method in which hot air is blown in the conveying direction of the film in the same direction up and down, a counter drying method in which hot air is blown in the conveying direction of the film in different vertical directions, hot air directly from the top and bottom of the film and methods such as a float drying method for blowing air.

[Optical member]

According to one aspect of this invention, the optical member which has the adhesive layer for optical films mentioned above and the 1st optical film formed in one side of this adhesive layer is provided.

In addition, the optical member of the present invention may further have a glass or a second optical film on the surface opposite to the surface on which the first optical film is formed of the pressure-sensitive adhesive layer of the present invention. Here, the "first optical film" and the "second optical film" may be films having the same structure (material, function, etc.) or films having different structures (material, function, etc.). Moreover, in this invention, the aspect in which the 1st optical film (or 2nd optical film) is a polarizing plate is also provided.

In the present invention, the pressure-sensitive adhesive described above may be applied directly to one or both surfaces of the optical film to form an adhesive layer. However, it is preferable to use by forming an adhesive layer in advance on a separator etc. for the above-mentioned reason, and transferring this to one side or both surfaces of an optical film. In addition, before the transfer, the surface of the optical film may be subjected to a basic treatment such as formation of an easily adhesive treatment layer or formation of an antistatic layer depending on the material thereof. Moreover, you may perform an easily bonding process also in the surface of an adhesive layer. It is preferable to have an easily bonding process layer between an optical film and the adhesive layer for optical films of this invention from a viewpoint of strongly adhering an optical film and an adhesive layer.

<Easily Adhesive Process Layer (Easily Adhesive Layer)>

It is preferable that the optical member of this invention further has an easily bonding process layer of at least 1 layer between the said 1st optical film and the said adhesive layer for optical films.

Moreover, as a more preferable aspect, the said easily adhesion process layer has a 1st easily adhesion process layer and a 2nd easily adhesion process layer. And as for the said optical member, the 1st optical film, the 1st easily adhesion process layer, the 2nd easily adhesion process layer, and the adhesive layer for optical films are laminated|stacked in this order. Thus, in an optical member, the structure which has both a 1st and 2nd easily bonding process layer is preferable from a viewpoint of making an optical film and an adhesive layer adhere|attach more strongly.

As an easily bonding process layer, what processes the surface of the member which contacts an adhesive layer, such as a corona treatment and a plasma treatment, may be sufficient. Alternatively, another member such as a primer layer may be formed on the surface of the member in contact with the pressure-sensitive adhesive layer.

The material constituting the primer layer preferably has good adhesion to the member in contact with the primer layer and forms a film excellent in cohesive force. For example, various polymers, metal oxide sols, silica sols, etc. can be used, and among them, polymers can be preferably used. The primer layer may have an antistatic function.

Examples of the polymer constituting the primer layer include an oxazoline group-containing polymer, a polyurethane resin, a polyester resin, and a polymer containing an amino group in its molecule. Among these, a polyurethane resin and an oxazoline group-containing polymer can be used more preferably.

As the oxazoline group-containing polymer, a commercially available product can be used. Examples include, but are not limited to, the EPOCROS (registered trademark) series (eg, EPOCROS (registered trademark) W700) manufactured by Nippon Shokubai Co., Ltd. . In addition, for polyurethane resins, polyester resins, polymers containing an amino group in a molecule, etc., the substances disclosed in paragraphs "0107" to "0113" of Japanese Patent Application Laid-Open No. 2011-105918 can be suitably used.

It is preferable that they are 10 nm or more and 5000 nm or less, and, as for the thickness of a primer layer, it is more preferable that they are 50 nm or more and 500 nm or less. An optical characteristic can be maintained, exhibiting sufficient intensity|strength and adhesiveness within the said range.

The formation method of a primer layer is not specifically limited, For example, the method of apply|coating the raw material (prime material) of a primer layer using coating methods, such as a coating method, a dipping method, a spray method, and drying is mentioned.

<Optical Film>

In the present invention, as the optical film (the first optical film or the second optical film), an optical compensation film such as a polarizing plate, a retardation plate as anti-coloration, a viewing angle magnifying film for improving the viewing angle of a liquid crystal monitor, and the contrast of the display The brightness improving film for raising it, the laminated body etc. by which these are laminated|stacked on it are mentioned. However, it is not limited to these. Preferably the optical film (the first optical film or the second optical film) is a polarizing plate. Hereinafter, a polarizing plate is demonstrated.

[Polarizer]

A polarizing plate suitable as an optical film in the present invention can be manufactured by bonding a protective film and a polarizer to each other using an adhesive by a conventionally known method, and curing by heat drying or UV rays, electron beams, or the like. The applied adhesive forms an adhesive layer by drying or curing with ultraviolet rays, electron beams, or the like to express adhesiveness.

There is no restriction|limiting in particular as a polarizer, A conventionally well-known product can be used. For example, by adsorbing a dichroic material such as oxo or a dichroic dye to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formylated polyvinyl alcohol-based film, or an ethylene/vinyl acetate copolymer-based partially saponified film, uniaxial and polyene-based oriented films such as the stretched product, a dehydration treatment product of polyvinyl alcohol, and a dehydrochloric acid treatment product of polyvinyl chloride.

Among these, a polarizer produced by dyeing a polyvinyl alcohol film having an average degree of polymerization of 2000 or more and 2800 or less and a saponification degree of 90 mol% or more and 100 mol% or less with oxo and uniaxially stretched 3 times or more and 8 times or less is particularly preferable. More specifically, such a polarizer can be obtained by immersing a polyvinyl alcohol film in the aqueous solution of oxo, dyeing, and extending|stretching, for example.

As a method of immersing in the aqueous solution of oxo, it is preferable to immerse in the aqueous solution containing 0.1 mass % or more and 10 mass % or less of oxo and/or potassium iodide, for example. Moreover, you may immerse in aqueous solutions, such as 50 degreeC or more and 70 degrees C or less boric acid, potassium iodide, as needed, and you may immerse in 25 degreeC or more and 35 degrees C or less water for washing|cleaning and stain|dye stain prevention. The stretching may be performed after dyeing with iodine, or stretching while dyeing, or dyeing with oxo after stretching. After dyeing and extending|stretching, you may wash with water as needed, and you may dry it for about 1 minute or more and 10 minutes or less at 35 degreeC or more and 55 degrees C or less. Various of these polarizers may be obtained as a commercial product.

In addition, the thickness in particular of a polarizer is although it does not restrict|limit, Generally, they are 3 micrometers or more and 80 micrometers or less.

In this invention, the polarizing plate in which the single side|surface or both surfaces were protected as an optical film from a viewpoint that higher durability is calculated|required as an optical film is preferable. More preferably, it is a polarizing plate (single side protection polarizing plate) in which one side was protected. It does not restrict|limit especially as a method of protection, A well-known method, such as bonding a protective film to each other, can be used suitably.

As a protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is preferable. For example, acrylic resin, cellulose resin such as triacetyl cellulose, polyester resin such as polyethylene terephthalate or polyethylene naphthalate, polyethersulfone resin, polysulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin (meth)acrylic resins such as resins and polymethyl methacrylate, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, epoxy resins, and mixtures thereof. .

Meanwhile, a transparent protective film may be bonded to one side of the polarizer by an adhesive. However, on the other side, as the transparent protective film or protective layer, a thermosetting resin or ultraviolet curable resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone can be used.

The thickness in particular of a polarizing plate is not restrict|limited, Although generally 20 micrometers or more and 200 micrometers or less, it is preferable that it is 100 micrometers or less from a viewpoint of thickness reduction. Such a thin polarizing plate is preferable from a viewpoint of expressing the effect of the adhesive of this invention more notably.

The manufacturing method of a polarizing plate is not specifically limited, For example, after apply|coating an adhesive agent, the method of mutually bonding a polarizer and a protective film with a roll laminator etc. is mentioned. After bonding to each other, it may be appropriately dried or cured by ultraviolet rays, electron beams, or the like. In addition, when apply|coating an adhesive agent, you may apply|coat to either a protective film and a polarizer, and you may apply|coat to both. It is preferable to apply an adhesive agent so that the thickness of the adhesive layer after drying will be 10 nm or more and 10 micrometers or less. Moreover, it does not specifically limit as an adhesive agent, According to the material of a polarizer, it can employ|adopt suitably as a well-known substance. For example, when a polyvinyl alcohol-based film is used as the polarizer, an acryl-based, epoxy-based, or acrylic-epoxy-based adhesive may be used as the polyvinyl alcohol-based adhesive or UV-curable adhesive. The thickness of the adhesive layer is preferably 10 nm or more and 200 nm or less in the polyvinyl alcohol-based adhesive to obtain a uniform in-plane thickness and sufficient adhesive strength. In an ultraviolet curing adhesive, it is preferable that they are 0.2 micrometer or more and 10 micrometers or less.

In the present invention, a pressure-sensitive adhesive polarizing plate having a pressure-sensitive adhesive layer may also be provided. Meanwhile, the configuration and manufacturing method of the pressure-sensitive adhesive polarizing plate are the same as in the case of the above-described optical film having the pressure-sensitive adhesive layer, and thus a description thereof will be omitted.

[Image display device]

The present invention also provides an image display device using at least one of the above-described optical members.

It does not specifically limit as an image display apparatus, For example, a liquid crystal display device, an organic LED display, a flat panel display (PD), a micro LED display, etc. are mentioned. In addition, from a viewpoint of expressing the effect of the adhesive for optical films of this invention more remarkably, especially a thin image display apparatus is applied preferably.

<Example>

The present invention will be described in more detail using the following examples and comparative examples, but the technical scope of the present invention is not limited to the following examples.

In addition, in the following operation, unless otherwise stated, operation and measurement of physical properties etc. were made into the conditions of 23 degreeC and 55% HH relative humidity.

(Measurement of weight average molecular weight (Ml) of (meth)acrylic acid ester copolymer (A))

The weight average molecular weight of each (meth)acrylic acid ester copolymer (A) prepared in the following Preparation Example was measured by gel permeation chromatography (GPC) (see below for measurement conditions):

・Analysis device: Tosoh Co., Ltd. product, HLC-8120GPPC

· Column: G7000HXL+GMTHXL+GMTHXL, made by Tosoh Co., Ltd.

·Column size: each 7.8 mm φ × 30 cm total 90 cm

·Column temperature: 40℃

Flow rate: 0.8ml/mｉｎ

・Injection amount: 100μl

·Eluent: tetrahydrofuran

・Detector: Differential Refractometer (RI)

·Standard sample: polystyrene.

(Measurement of weight average molecular weight (Ml) of silicate oligomer (F))

In addition, the weight average molecular weight of the silicate oligomer (F) used in the following examples was measured by gel permeation chromatography (GPC) (refer to the following for measurement conditions):

・Analysis device: Tosoh Co., Ltd. product, HLC-8120GPPC

·Column: ＴＳＫｇｅｌ ＳｕｐｅｒＨＺM-H/HＺ4000/HＺ2000

·Column size: 6.0mm I. D. × 150mm

·Column temperature: 40℃

Flow rate: 0.6ml/mｉｎ

・Injection amount: 20μl

·Eluent: tetrahydrofuran

・Detector: Differential Refractometer (RI)

·Standard sample: polystyrene.

(Calculation of glass transition temperature (Tg) of (meth)acrylic acid ester copolymer (A))

The glass transition temperature of the (meth)acrylic acid ester copolymer (A) was calculated from the glass transition temperature of the homopolymer of the monomer constituting the polymer and the content thereof, by the following formula:

Equation of TF: 1/TV= (w1/TV1)+ (w2/TV2)+...+ (t/TV)

Tg: the glass transition temperature (K) of the polymer

TG1, TG2, ... TG: Glass transition temperature (K) of the homopolymer of each monomer

w1, w2, ... d: weight fraction of each monomer.

(Manufacture of single-sided protection polarizing plate)

Between rolls with different speed ratios, the 45-micrometer-thick polyvinyl alcohol film was extended|stretched up to 3 times, dyeing|staining for 1 minute in 30 degreeC and 0.3 mass % density|concentration oxo solution. Then, the film extended|stretched to 3 times was extended|stretched until the total draw ratio became 6 times, immersing for 0.5 minute in the aqueous solution containing 60 degreeC, 4 mass % concentration of boric acid, and 10 mass % concentration potassium iodide. Next, after washing|cleaning the film extended|stretched to 6 times by immersing for 10 second in 30 degreeC and the aqueous solution containing 1.5 mass % concentration of potassium iodide, it dried at 50 degreeC for 4 minutes, and obtained the polarizer. On one side of the polarizer, a uniaxially stretched PTV film (COSMOSHINE (registered trademark) super-birefringent type (SFT) film) having a thickness of 80 μm is bonded to each other with a polyvinyl alcohol-based adhesive, and a total A single-sided protection thin polarizing plate (also referred to simply as a single-sided protection polarizing plate) having a thickness of 98 µm was manufactured.

[Production Example 1: Preparation of solution of (meth)acrylic acid ester copolymer (A1)]

50 parts by mass of n-butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 2-ethylhexyl acrylate (Osaka Organic Chemical) in a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler 29 parts by mass (manufactured by Kogyo Co., Ltd.), 2-methoxyethyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 2-ethylhexyl-diglycol acrylate (Kyoeisha Chemical) (manufactured by 共榮社) 10 parts by mass, 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Co., Ltd.) 1 part by mass and 2,2'-azobis as a polymerization initiator 0.1 mass parts of isobutyronitrile (made by Fujifilm Wako Pure Chemical Industries, Ltd.) was inject|poured with 100 mass parts of ethyl acetate, and nitrogen gas was introduce|transduced, stirring gently. After nitrogen gas replacement, the temperature of the liquid in the flask was raised until ethyl acetate was refluxed, polymerization was performed for 5 hours, and a solution of (meth)acrylic acid ester copolymer (A1) with a weight average molecular weight (Md) of 1.25 million Manufactured.

[Production Examples 2 to 15: Preparation of solutions of (meth)acrylic acid ester copolymers (A2) to (A15)]

The same operation as in Production Example 1 was performed except that the type and composition ratio of each monomer forming the (meth)acrylic acid ester copolymer was changed as shown in Table 1 below, and the amount and reaction time of the polymerization initiator were appropriately changed. , to prepare solutions of (meth)acrylic acid ester copolymers (A2) to (A15). Table 1 also shows the glass transition temperature (Tg) and weight average molecular weight (Mg) of the (meth)acrylic acid ester copolymers (A1) to (A15). On the other hand, a blank in Table 1 means that the monomer is not used.

polymer number Monomer composition (parts by mass) AIBN
(parts by mass) Tg
(℃) Mw x 10 ⁴ (a1)
BA (a1)
2EHA (a2)
MEA (a2)
EC-A (a2)
EHDG-AT (a3)
4HBA (a3)
HEAA (a3)
AAEM (a4)
AA Preparation Example 1 A1 50 29 10 10 One 0.1 -50.7 125 Preparation Example 2 A2 50 29 20 One 0.1 -53.2 125 Preparation 3 A3 50 29 20 One 0.1 -52.5 125 Preparation 4 A4 29 50 10 10 One 0.1 -53.1 125 Production Example 5 A5 29 50 20 One 0.1 -54.6 125 Preparation 6 A6 50 29 20 One 0.1 -51.9 125 Preparation 7 A7 50 28 20 One One 0.1 -52.0 125 Preparation 8 A8 50 29 20 One 0.3 -52.5 80 Preparation 9 A9 50 29 20 One 0.05 -52.5 170 Production Example 10 A10 30 49 20 One 0.1 -50.9 125 Preparation 11 A11 50 49 One 0.1 -49.9 125 Preparation 12 A12 50 29 20 One 0.01 -52.5 250 Production Example 13 A13 50 29 20 One 0.8 -52.5 50 Preparation 14 A14 99.4 0.1 0.5 0.1 -44.5 130 Production Example 15 A15 30 69 One 0.1 -60.5 125

Note) BA: n-butyl acrylate (manufactured by Nippon Shokubai Co., Ltd., homopolymer Tg: -45°C)

2EHA: 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd., homopolymer Tg: -68°C)

MEA: 2-methoxyethyl acrylate (manufactured by Nippon Shokubai Co., Ltd., Tg of homopolymer: -50°C)

EC-A: ethoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., homopolymer Tg: -70°C)

EHDG-AT: 2-ethylhexyldiglycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., homopolymer Tg: -67°C)

4HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., homopolymer Tg: -32°C)

HEAA: hydroxyethyl acrylamide (manufactured by KK Chemicals, Tg of homopolymer: 98°C)

AA: acrylic acid (manufactured by Nippon Shokubai Co., Ltd., homopolymer Tg: 106°C)

AAEM: 2-acetoacetoxyethyl methacrylate (manufactured by Nippon Synthetic Chemical Co., Ltd., homopolymer Tg: 9°C)

<Example 1>

[Preparation of adhesive for optical film]

Takenate (B) as a crosslinking agent (B) with respect to 100 parts by mass of the solid content of the (meth)acrylic acid ester copolymer (A1) solution obtained in Production Example 1 (that is, 100 parts by mass of the (meth)acrylic acid ester copolymer (A1)) TAKANATE) (registered trademark) D-110N (75 wt% ethyl acetate solution of trimethylolpropane adduct of xylene diisocyanate, the number of isocyanate groups in 1 molecule: 3, manufactured by Mitsui Chemicals Co., Ltd.) 0.1 parts by mass ( In terms of active ingredient), and as a silane coupling agent (C), KBM-403 (3-glycidoxypropyl trimethoxysilane, manufactured by Shinyetsu Chemical Industry Co., Ltd.) 0.1 parts by mass of mixing with stirring, the optical film The adhesive (solid content 25 mass %) for this was manufactured.

[Formation of the pressure-sensitive adhesive layer]

The thickness of the pressure-sensitive adhesive layer after drying on one side of a 38 μm thick polyethylene terephthalate (PTV) film (manufactured by Mitsubishi Chemical Co., Ltd., MMF38, without oligomer prevention layer) to which the pressure-sensitive adhesive for optical film obtained above was silicone-treated It applied so that it might become 25 micrometers. Then, it heat-processed at 110 degreeC for 4 minutes, and the adhesive layer of Example 1 was formed. In addition, heat processing was performed by the method of the float drying system which blows hot air directly from the top and bottom of the film.

[Production of optical member (single-sided protective polarizing plate with adhesive layer)]

The corona treatment was carried out to the polarizer side which forms the adhesive layer of said single-sided protection polarizing plate with the amount of corona discharge 80 [W·mg/m ² ]. Next, on the surface of the polarizer to which this corona treatment was carried out, the pressure-sensitive adhesive layer formed on the PTV film subjected to the above-mentioned silicone treatment was transferred, and an optical member (single-sided protective polarizing plate with an adhesive layer) was produced.

<Examples 2 to 19 and Comparative Examples 1 to 5>

As shown in Table 2 and Table 3 below, (meth)acrylic acid ester copolymer (A), crosslinking agent (B), silane coupling agent (C), silicate oligomer (D), high softening point constituting the adhesive for optical film In the same manner as in Example 1 except that the type and amount (compounding amount) of the resin (E) and (meth)acrylic (co)polymer (F) were changed, Examples 2 to 19 and Comparative Examples 1 to 5 were performed. An optical member (single-sided protective polarizing plate with an adhesive layer) was produced.

copolymer
(A) crosslinking agent 1
(B) Crosslinking agent 2
(B) Silane coupling agent
(C) type type addition amount
(parts by mass) type addition amount
(parts by mass) type addition amount
(parts by mass) Example 1 A1 D-110N 0.1 - - KBM-403 0.1 Example 2 A1 D-110N 0.1 P-6090 0.2 KBM-403 0.1 Example 3 A1 D-110N 0.1 TCP 0.3 KBM-403 0.1 Example 4 A1 D-110N 0.1 TCP 0.3 KBM-403 0.1 Example 5 A1 D-110N 0.1 TCP 0.3 - - Example 6 A1 D-110N 0.1 TCP 0.3 KBM-403 0.1 Example 7 A1 D-110N 0.1 TCP 0.3 KBM-403 0.1 Example 8 A1 D-110N 0.1 TCP 0.3 KBM-403 0.1 Example 9 A1 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 10 A1 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 11 A2 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 12 A3 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 13 A4 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 14 A5 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 15 A6 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 16 A7 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 17 A8 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 18 A9 D-110N 0.1 TCP 0.3 KBE-403 0.1 Example 19 A10 D-110N 0.1 TCP 0.3 KBE-403 0.1 Comparative Example 1 A11 D-110N 0.1 - - KBM-403 0.1 Comparative Example 2 A12 D-110N 0.1 - - KBM-403 0.1 Comparative Example 3 A13 D-110N 0.1 - - KBM-403 0.1 Comparative Example 4 A14 D-110N 0.1 - - KBM-403 0.1 Comparative Example 5 A15 D-110N 0.1 - - KBM-403 0.1

silicate oligomer (D) High Softening Point Resin (E) (meth)acrylic (co)polymer (F) type addition amount
(parts by mass) Mw type addition amount
(parts by mass) type addition amount
(parts by mass) Example 1 - - - - - - - Example 2 - - - - - - - Example 3 - - - - - - - Example 4 Methylsilicate 53A 5 900 - - - - Example 5 Methylsilicate 53A 5 900 - - - - Example 6 - - - KE-100 5 - - Example 7 - - - KE-100 20 - - Example 8 - - - A-75 5 - - Example 9 - - - Tamanol 460 2.5 - - Example 10 - - - - - UH-2170 5 Example 11 - - - - - - - Example 12 - - - - - - - Example 13 - - - - - - - Example 14 - - - - - - - Example 15 - - - - - - - Example 16 - - - - - - - Example 17 - - - - - - - Example 18 - - - - - - - Example 19 - - - - - - - Comparative Example 1 - - - - - - - Comparative Example 2 - - - - - - - Comparative Example 3 - - - - - - - Comparative Example 4 - - - - - - - Comparative Example 5 - - - - - - -

In Table 2 and Table 3,

1. The addition amount (unit: mass part) of (B), (C), (D), (E) and (F) component means the addition amount when copolymer (A) is 100 mass parts

2. "-" in the table means that the relevant component is not mix|blended.

3. "D-110N": Mitsui Chemicals Co., Ltd. product (TAKANATE (registered trademark) D-110N, 75 wt% ethyl acetate solution of the trimethylolpropane adduct of xylene diisocyanate, 1 molecule The number of isocyanate groups in: 3).

4. "P-6090": Sanyo Chemical Industry Co., Ltd. product (SANPRENE (registered trademark) P-6090, both reacted with polytetramethylene ether glycol and diphenylmethane diisocyanate) It is a prepolymer which has an isocyanate group at the terminal, NCO%: 7.6%).

5. "TVP": A product (Paroyl (registered trademark) TPD, bis(4-t-butylcyclohexyl)peroxydicarbonate) manufactured by Ilyu Co., Ltd.

6. 「KBM-403」: It is a product (3-glycidoxypropyltrimethoxysilane) of Shinyetsu Chemical Industry Co., Ltd.

7. 「KBM-403」: It is a product of Shinyetsu Chemical Industry Co., Ltd. (3-glycidoxypropyltriethoxysilane).

8. “Methyl silicate 53A”: a product (trade name: methyl silicate 53A) manufactured by Gorukoto Co., Ltd.

9. 「KE-100」: A product made by Arakawa Chemical Industry Co., Ltd. (PINECRYSTAL KE-100, softening point 95-105℃ (circular ball method), light pale rosin derivative).

10. 「A-75」: It is a product made by Arakawa Chemical Industry Co., Ltd. (SUPER ESTER A-75, softening point 70-80℃ (circular ball method), special rosin ester).

11. 「TAMANOL 460」: A product made by Arakawa Chemical Industry Co., Ltd. (softening point 182-192℃ (round ball method), rosin-modified phenolic resin).

12. 「U-2170」: Product made by Dong-A Synthesis Co., Ltd. (ARUON (registered trademark) UH-2170, solvent-free styrene acrylic polymer, weight average molecular weight (Mg) 14,000, glass transition temperature (Tg) 60°C).

[evaluation]

The following evaluations were made for the adhesive for optical films prepared in Examples 1 to 19 and Comparative Examples 1 to 5, and a single-sided protective polarizing plate (sample) with an adhesive layer as an optical member.

<Bubble at the edge>

The optical member (a single-sided protective polarizing plate with an adhesive layer) produced in Examples 1 to 19 and Comparative Examples 1 to 5 was cut into a 37-inch size and referred to as a sample, and alkali-free glass (Eagle, manufactured by Corning, Inc., EAGLE) having a thickness of 0.7 mm ) was joined to XG) using a laminator. Then, it autoclaved for 15 minutes at 50 degreeC, 0.5 Mp, and the said sample was made to closely_contact|adhere to alkali-free glass completely. The samples subjected to the treatment were subjected to the durability tests of the following (1) to (2), respectively, and after each test, the appearance between the polarizing plate and the glass was visually evaluated on the basis of the following criteria. In this evaluation, bubbles generated within 1 mm of the edges of both sides of the polarizing plate in the stretching direction were observed:

(1) Treated at 85°C for 500 hours (heating test)

(2) After leaving in an environment of 85°C for 30 minutes, leaving it to stand for 30 minutes in an environment of -40°C was regarded as 1 cycle (1 hour), and a total of 300 cycles (300 hours) were treated (thermal shock) (HS) test. ).

visual evaluation

(double-circle): There is no bubble newly generated in the edge part at all

○: Although there is a slight amount of bubbles generated at the edge, there is no problem in practical use

(triangle|delta): Although there is a bubble in the edge part, unless it is a special use, there is no problem practically

x: There are a remarkable number of bubbles in the edge part, and there is a problem practically

<Bending>

The optical member (a single-sided protective polarizing plate with an adhesive layer) produced in Examples 1 to 19 and Comparative Examples 1 to 5 was cut to a size of 100 mm in length × 50 mm in width, and was referred to as a sample. This sample was joined to the alkali-free glass (the Corning company make, EAGLE XG) of length 75 mm x width 150 mm x thickness 0.5 mm using a laminator. Then, the autoclave process was carried out for 15 minutes at 50 degreeC, 0.5 Mp, and the said sample was made to closely_contact|adhere to alkali-free glass completely. The samples subjected to the treatment were further subjected to heat treatment at 85° C. for 100 hours, respectively. After that, after leaving it for 1 hour under the conditions of 25℃ and 55% RH, place it on a horizontal plane so that the convex side of the warp is down, and the distance from the longest point on the horizontal plane among the four corner points (mm) ) was measured. The evaluation criteria are as follows:

-Evaluation standard-

◎: Deflection amount 0mm or more and less than 0.5mm

○: Deflection 0.5mm or more and less than 1.0mm

△: Deflection amount 1.0 mm or more and less than 1.5 mm

x: 1.5 mm or more of curvature amount.

<Taeun>

Immediately after application (immediately after transferring the PTV film with an adhesive layer; within 10 minutes after transfer) produced in Examples 1 to 19 and Comparative Examples 1 to 5, the optical member (one-sided protective polarizing plate with an adhesive layer) was 100 mm long × It was cut to a size of 100 mm in width to prepare a total of 300 test pieces (samples). These test pieces were stacked with the PTV film (protective film) surface (the protective film surface on the side in which the adhesive layer is not formed) of the polarizing plate facing up. A load of 1 kg was applied from the top, and it was left to stand for 1 day under the conditions of 23 degreeC and 50% RH of relative humidity, and the generation depth of a dent was evaluated with the laser microscope (VV-X120) manufactured by Giens Corporation. The evaluation criteria are as follows:

-Evaluation standard-

(double-circle): Depth of dent 0μm or more and less than 1μm

○: 1 μm or more and less than 3 μm in depth of the dent

△: The depth of the dent is 3 μm or more and less than 5 μm

x: depth of 5 micrometers or more of dents.

<Durability>

The optical member (one-sided protective polarizing plate with an adhesive layer) produced in Examples 1 to 19 and Comparative Examples 1 to 5 was cut to a size of 37 inches and referred to as a sample, and alkali-free glass (Corning Corporation, Eagle (Eagle) having a thickness of 0.7 mm EAGLE) and XG) were joined using a laminator. Then, the autoclave process was carried out for 15 minutes at 50 degreeC, 0.5 Mp, and the said sample was made to closely_contact|adhere to alkali-free glass completely. The samples subjected to the treatment were respectively subjected to the durability tests of the following (1) to (3), and after each test, the appearance between the polarizing plate and the glass was visually evaluated on the basis of the following criteria. In this evaluation, the entire polarizing plate was visually observed:

(1) Treated at 85°C for 500 hours (heating test)

(2) Treated for 500 hours in an atmosphere of 60°C/95% relative humidity RH (humidification test)

(3) After leaving in an environment of 85°C for 30 minutes, leaving it to stand in an environment of -40°C for 30 minutes was referred to as 1 cycle (1 hour), and a total of 300 cycles (300 hours) was treated (thermal shock (H S) test).

visual evaluation

(double-circle): There is no change in appearance, such as foaming, peeling, and a float.

0: Although there is some peeling or foaming at the edge, there is no practical problem

△: There is peeling or foaming at the edge, but there is no practical problem unless it is for a special purpose

x: There is remarkable peeling in the edge part, and there is a problem practically

<Rework Castle>

The optical members produced in Examples 1 to 19 and Comparative Examples 1 to 5 were cut to a width of 25 mm × a length of 100 mm as Sample 1, and what was cut to a length of 420 mm × width 320 mm was called Sample 2 (three sheets produced). Each of these samples 1 and 2 was affixed on an alkali-free glass plate (made by Corning Corporation, EAGLE XG) having a thickness of 0.7 mm using a laminator. Then, it was autoclaved for 15 minutes at 50 degreeC and 506.5 pa (5 a pm), and it adhered completely (initial stage). Then, it heat-processed on 50 degreeC drying conditions for 48 hours (after heating).

The initial adhesive force of Sample 1 and the adhesive force after heating were measured. Adhesive strength was measured in a tensile tester (Orientec Co., Ltd., Tenshiron universal material tester, STV-1150) under conditions of 23 ° C and 50% RH at a peel angle of 180 °, and a peel rate of 300 mm/mH at a peeling angle of JOS Z0237 (2009). It calculated|required by measuring the adhesive force (N/25mm) at the time of peeling Sample 1 according to the method of an adhesive tape and an adhesive sheet test.

In addition, about the said sample 2 (3 sheets), the sample was peeled from an alkali-free-glass plate by human hand, and the rework property was evaluated based on the following reference|standard (actual rework property):

Evaluation standard

◎: All three sheets can be peeled off well without adhesive residue or film breakage

0: Although the film fractured|ruptured in some of 3 sheets, it peeled off again by peeling.

(triangle|delta): Although the film fractured|ruptured in all three sheets, it peeled off again by peeling.

×: The adhesive residue was generated in all three sheets, or the film was not peeled off even after being peeled off several times.

Each evaluation result is shown in Table 4 below.

edge
bubble warp tahin durability rework castle Early after heating 85℃
500hr HS 300 cycles 85℃
500hr 60℃95%RH
500hr HS 300 cycles adhesion
(N/25mm) real
rework castle adhesion
(N/25mm) real
rework castle Example 1 ◎ ◎ ○ △ ◎ ◎ ◎ 1.8 ◎ 2.5 ◎ Example 2 ○ ○ ○ ○ ◎ ○ ◎ 1.2 ◎ 2.0 ◎ Example 3 ◎ ◎ ◎ ○ ◎ ○ ◎ 1.3 ◎ 1.5 ◎ Example 4 ◎ ◎ ◎ ○ ◎ ◎ ◎ 2.3 ◎ 2.8 ◎ Example 5 ◎ ◎ ◎ ○ ◎ ◎ ◎ 2.1 ◎ 2.6 ◎ Example 6 ◎ ◎ ◎ ○ ◎ ◎ ◎ 2.0 ◎ 2.8 ◎ Example 7 ◎ ◎ ◎ ◎ ◎ ◎ ◎ 2.5 ◎ 3.0 ◎ Example 8 ◎ ◎ ◎ ◎ ○ ◎ ○ 3.1 ○ 3.5 ○ Example 9 ◎ ◎ ◎ ◎ ○ ◎ ○ 2.8 ◎ 3.3 ○ Example 10 ◎ ◎ ◎ ○ ◎ ◎ ◎ 2.5 ◎ 3.2 ○ Example 11 ◎ ◎ ◎ ○ ○ ◎ ◎ 1.4 ◎ 1.4 ◎ Example 12 ◎ ◎ ◎ ○ ◎ ◎ ◎ 1.3 ◎ 1.5 ◎ Example 13 ◎ ◎ ◎ ○ ◎ ◎ ◎ 1.5 ◎ 1.5 ◎ Example 14 ◎ ◎ ○ ○ ◎ ◎ ◎ 1.2 ◎ 1.2 ◎ Example 15 ◎ ◎ ◎ ○ ◎ ◎ ◎ 1.3 ◎ 1.3 ◎ Example 16 ◎ ◎ ◎ ○ ◎ ◎ ◎ 1.4 ◎ 1.4 ◎ Example 17 ○ ◎ ◎ △ ○ ◎ ◎ 2.5 ◎ 4.2 △ Example 18 ◎ ◎ ○ ◎ ◎ ◎ ◎ 1.6 ◎ 2.6 ◎ Example 19 ○ ◎ ○ △ △ ○ ○ 3.5 ○ 4.8 △ Comparative Example 1 - - ⅹ Peel ○ ⅹ ◎ ⅹ 4.2 △ 6.5 ⅹ Comparative Example 2 - - - - - - - - - - Comparative Example 3 - - ⅹ Peel ⅹ ⅹ ◎ ⅹ 3.5 ○ 6.3 ⅹ Comparative Example 4 ⅹ ⅹ ○ ○ ◎ ◎ ◎ 3.4 ○ 4.5 △ Comparative Example 5 ◎ ◎ ◎ ⅹ ○ ◎ △ 0.9 ◎ 1.2 ◎

As is clear from Table 4 above, the single-sided protective polarizing plate with an adhesive layer produced using the adhesive for optical films of Examples 1 to 19 is durable (especially in a harsh environment (high temperature, high humidity, thermal shock)) , suppression of bubbles generated at the edge of the polarizing plate and suppression of peeling of the polarizing plate) were improved. Moreover, it turned out that both curvature and a dent can be suppressed, and also it was excellent also in rework property (workability).

On the other hand, in the one-sided protective polarizing plate with an adhesive layer of Comparative Example 1 and Comparative Example 3, peeling of the polarizing plate occurred in the warpage test, and it was not possible to evaluate the bubble at the edge. As for the adhesive of the comparative example 2, Ml of a copolymer (A) was too high, a gel generate|occur|produced, and the sample for evaluation was not able to be produced. In the single-sided protective polarizing plate with a pressure-sensitive adhesive layer of Comparative Example 4, bubbles at the edge were deteriorated, and the single-sided protective polarizing plate with a pressure-sensitive adhesive layer of Comparative Example 5 could not suppress dents.

Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (28)

As an optical film adhesive containing (meth)acrylic acid ester copolymer (A),
The (meth)acrylic acid ester copolymer (A)
(a1) 10 mass % or more and 95 mass % or less of structural units derived from (meth)acrylic-acid alkylester monomer;
(a2) 5 mass % or more and 90 mass % or less of structural units derived from the (meth)acrylic-acid alkyl ester monomer which has an alkoxyalkylene glycol group;
(a3) More than 0% by mass and less than 5% by mass of structural units derived from a functional group-containing monomer that is a (meth)acrylic acid derivative monomer having one radically polymerizable functional group (provided that the above (a1), (a2) and (a3) derived The total amount of structural units includes 100 mass %),
The (meth)acrylic acid ester copolymer (A) has a glass transition temperature of more than -55°C and -50°C or less, and a weight average molecular weight of 700,000 or more and 2 million or less,
The (meth)acrylic acid alkyl ester monomer having the alkoxyalkylene glycol group is a compound represented by the following formula (1), the pressure-sensitive adhesive for an optical film:
[Formula 1]

In Formula 1, R ₁₁ is a hydrogen atom or a methyl group, R ₁₂ is -(AO)nX,
A is an alkylene group having 1 or more and 4 or less, n is 1 or more and 10 or less, and X is an alkyl group having 1 or more and 20 or less.
The method according to claim 1, wherein the (meth)acrylic acid ester copolymer (A) further comprises a structural unit derived from a monomer (a4) other than (a1), (a2), and (a3),
Content of the structural unit derived from the said monomer (a4) is 0.01 mass part or more and 10 mass parts or less with respect to a total of 100 mass parts of the structural unit derived from said (a1), said (a2), and said (a3), The adhesive for optical films .
The adhesive for optical films of Claim 1 or 2 whose weight average molecular weight of the said (meth)acrylic acid ester copolymer (A) is more than 1 million and 1.5 million or less.
The adhesive for optical films of Claim 1 or 2 whose carbon number of the alkoxy group which the (meth)acrylic-acid alkylester monomer which has the said (a2) alkoxyalkylene glycol group has is 2 or more and 18 or less.
The (meth)acrylic acid ester monomer or The (meth)acrylamide monomer, the adhesive for optical films.
The adhesive for optical films of Claim 1 or 2 whose carbon number of the alkyl group which the said (a1) (meth)acrylic-acid alkylester monomer has is 1 or more and 18 or less.
The adhesive for optical films of Claim 1 or 2 whose content of the structural unit derived from the said (a1) (meth)acrylic-acid alkylester monomer is 15 mass % or more and 80 mass % or less.
The adhesive for optical films of Claim 1 or 2 in which the said (meth)acrylic acid ester copolymer (A) contains a hydroxyl group.
The pressure-sensitive adhesive for an optical film according to claim 1 or 2, further comprising a crosslinking agent (B).
The pressure-sensitive adhesive for an optical film according to claim 9, wherein the crosslinking agent (B) is included in an amount of 0.001 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic acid ester copolymer (A).
10. The optical film adhesive according to claim 9, wherein the crosslinking agent (B) is at least one selected from the group consisting of an isocyanate compound, a carbodiimide compound, an oxazoline compound, an epoxy compound, a polyfunctional acrylic acid ester monomer, and a peroxide.
The adhesive for optical film of Claim 1 or 2 which further contains 0.001 mass part or more and 5 mass parts or less of a silane coupling agent (C) with respect to 100 mass parts of said (meth)acrylic acid ester copolymer (A). .
The pressure-sensitive adhesive for an optical film according to claim 1 or 2, further comprising a silicate oligomer (D) represented by the following formula (4).
[Formula 4]

In Formula 4,
R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group;
X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 or more and 20 or less carbon atoms, or a phenyl group;
n is an integer of 1 or more and 100 or less.
The pressure-sensitive adhesive for an optical film according to claim 13, wherein the silicate oligomer (D) comprises a methylsilicate oligomer.
The pressure-sensitive adhesive for an optical film according to claim 13, wherein the silicate oligomer (D) has a weight average molecular weight of 300 or more and 30000 or less.
The pressure-sensitive adhesive for an optical film according to claim 9, wherein the crosslinking agent (B) contains an isocyanate compound having a number average molecular weight of 900 or more and 10,000 or less (however, block isocyanate compounds are excluded).
The pressure-sensitive adhesive for an optical film according to claim 1 or 2, further comprising a high softening point resin (E).
The pressure-sensitive adhesive for an optical film according to claim 17, wherein the high softening point resin (E) is a rosin ester-based resin.
The homopolymer of claim 1 or 2, wherein the homopolymer contains a structural unit derived from a (meth)acrylic monomer having a glass transition temperature of 50° C. or higher, and has a weight average molecular weight (Ml) higher than that of the (meth)acrylic acid ester copolymer (A). ) The small (meth)acrylic (co)polymer (F) further comprising, the pressure-sensitive adhesive for an optical film.
The pressure-sensitive adhesive for an optical film according to claim 19, wherein the (meth)acrylic (co)polymer (F) has a weight average molecular weight (Ml) of 500 or more and 100,000 or less.
A pressure-sensitive adhesive layer for an optical film, formed of the pressure-sensitive adhesive for an optical film of claim 1 or 2.
The pressure-sensitive adhesive layer for an optical film of claim 21 and
The optical member which has a 1st optical film laminated|stacked on one side of the said adhesive layer.
The optical member according to claim 22, further comprising a glass or a second optical film on a surface opposite to a surface on which the first optical film of the pressure-sensitive adhesive layer is laminated.
The optical member according to claim 22, further comprising at least one adhesive treatment layer between the first optical film and the pressure-sensitive adhesive layer for an optical film.
25. The method according to claim 24, wherein said adhesion treatment layer has a first tooth adhesion treatment layer and a second tooth adhesion treatment layer, and the optical member comprises: the first optical film, the first tooth adhesion treatment layer; An optical member wherein the second adhesive treatment layer and the pressure-sensitive adhesive layer for an optical film were laminated in this order.
An image display apparatus having at least one optical member according to claim 22.
A method for producing a pressure-sensitive adhesive layer for an optical film, comprising coating the pressure-sensitive adhesive for an optical film according to claim 1 or 2 on a release sheet subjected to a peeling treatment, and heat-treating it for crosslinking reaction.
The manufacturing method of the adhesive layer for optical films of Claim 27 whose temperature of the said heat processing is 80 degreeC or more and 120 degrees C or less.