JP2011116940A - Pressure-sensitive adhesive composition, pressure-sensitive adhesive and optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition which does not need a seasoning time when converted into a pressure-sensitive adhesive, does not cause performance change of the pressure-sensitive adhesive even when exposed to a cruel environment for a long term, and does not cause functional change by suppressing expansion and contraction etc., of a base material etc., to which the pressure-sensitive adhesive is applied; and to provide the pressure-sensitive adhesive and an optical film. <P>SOLUTION: The pressure-sensitive adhesive composition includes (A) 100 pts.wt. of a (meth)acrylate polymer with a weight-average molecular weight of 200,000-2,500,000, (B1) 1-100 pts.wt. of a reactive (meth)acrylate polymer having a weight-average molecular weight of 30,000-1,500,000 and ethylenic double bonds in its side chains, (B2) 1-50 pts.wt. of a polyene compound having two or more ethylenic double bonds, and (C) 0.01-50 pts.wt. of a polythiol compound having two or more mercapto groups. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pressure-sensitive adhesive composition that can be cured using active energy rays, a pressure-sensitive adhesive composed of the pressure-sensitive adhesive composition, and an optical film having a layer of the pressure-sensitive adhesive (hereinafter referred to as “pressure-sensitive adhesive layer”). . In particular, a pressure-sensitive adhesive composition that has a performance equivalent to or better than that of a conventional pressure-sensitive adhesive and does not require a conventionally required seasoning period, a pressure-sensitive adhesive comprising the pressure-sensitive adhesive composition, and an optical film having the pressure-sensitive adhesive layer About.

The pressure-sensitive adhesive is usually used for various applications by forming a pressure-sensitive adhesive layer by applying a pressure-sensitive adhesive composition mainly composed of a polymer to various adherends and substrates and volatilizing a diluting solvent. ing.
However, when it is necessary to clear harsh conditions such as optical use and outdoor use, it is sufficient durability by simply laminating a pressure-sensitive adhesive composition mainly composed of a polymer to form a pressure-sensitive adhesive layer. There was a problem that it was difficult to obtain sex.

Therefore, a pressure-sensitive adhesive that improves cohesion by adding a crosslinking agent or a curing agent and can withstand severe conditions has been developed (for example, Patent Document 1).
That is, Patent Document 1 discloses an adhesive obtained by irradiating an adhesive material containing an acrylic copolymer and an acrylic copolymer having an active energy ray polymerizable group in a side chain with active energy rays. Has been.

However, in the case of the pressure-sensitive adhesive of Patent Document 1, acrylic copolymers having an active energy ray polymerizable group are directly bonded to the side chain, so that, for example, the cross-linked sites tend to be excessively dense. There was a problem that it was difficult to stably control the degree of crosslinking.
Therefore, the pressure-sensitive adhesive of Patent Document 1 needs to finely adjust the degree of cross-linking in the acrylic copolymer by using an isocyanate cross-linking agent and the like, and therefore requires a predetermined seasoning period.

  On the other hand, various compositions containing a polythiol compound are disclosed (for example, Patent Documents 2 to 5).

JP 2006-309114 A (Claims) JP-A-63-280739 (Claims) JP-A-6-306172 (Claims) JP 2004-35734 A (Claims) JP 2009-1655 A (Claims)

However, in Patent Documents 2 to 5, there are no examples in which various compositions containing a polythiol compound are applied to a pressure-sensitive adhesive, and the above-described problems of Patent Document 1 have not been solved.
Accordingly, the seasoning period when the pressure-sensitive adhesive composition is used as a pressure-sensitive adhesive is unnecessary, and further, even when exposed to a harsh environment for a long time, the performance of the pressure-sensitive adhesive itself does not change. There has been a demand for an adhesive that does not cause a functional change by suppressing expansion and contraction of the base material to which the adhesive is applied.
More specifically, for example, the polarizing plate can be bonded with good durability to an adherend such as a liquid crystal cell while the seasoning period of the pressure-sensitive adhesive is not required, and optical characteristics such as light leakage and haze value. In addition, a pressure-sensitive adhesive that can be easily peeled off from an adherend even after a predetermined period has elapsed (reworkability) has been demanded.

Thus, the inventors of the present invention made extensive efforts in view of the above circumstances, and (A) a (meth) acrylic acid ester polymer having a predetermined weight average molecular weight and (B1) a predetermined weight average molecular weight. Seasoning is performed by containing a reactive (meth) acrylic acid ester polymer or (B2) a predetermined polyene compound or (B1) and (B2) and (C) a predetermined polythiol compound in a predetermined ratio. The inventors have found that good pressure-sensitive adhesive properties can be obtained regardless of environmental changes, and have completed the present invention.
That is, the object of the present invention is to eliminate the need for a seasoning period when the pressure-sensitive adhesive composition is used as a pressure-sensitive adhesive, and to prevent the pressure-sensitive adhesive itself from changing its performance even when exposed to a harsh environment for a long time. Of course, it is to provide a pressure-sensitive adhesive composition, a pressure-sensitive adhesive and an optical film which do not cause a functional change by suppressing expansion and contraction of a base material to which the pressure-sensitive adhesive is applied.

According to the present invention, the following components (A), (B1), (C), or the following components (A), (B2), (C), or the following components (A), (B1), (B2) The pressure-sensitive adhesive composition characterized by containing the component (C) can be provided to solve the above-mentioned problems.
(A) The weight average molecular weight is 200,000-2,500,000 (meth) acrylic acid ester polymer 100 parts by weight (B1) The weight average molecular weight is 30,000-1,500,000, and has an ethylenic double bond in the side chain 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule Part (A) (meth) acrylic acid ester polymer having a predetermined weight average molecular weight, (B1) reactive (meth) acrylic acid ester polymer having a predetermined weight average molecular weight or (B2) a predetermined polyene compound, Alternatively, since (B1) and (B2) and (C) a predetermined polythiol compound are blended at a predetermined ratio, (B1) component or (B2) component (by irradiation with active energy rays) ( Hereinafter, the (B1) component and the (B2) component may be collectively referred to as the (B) component.) And the (C) component are allowed to efficiently carry out an ene-thiol reaction. You can.
As a result, adhesive properties such as desired adhesive strength and storage elastic modulus can be obtained only by photocrosslinking between the component (B) and the component (C) without separately performing thermal crosslinking with an isocyanate or the like.
Moreover, since the (meth) acrylic acid ester polymer as the component (A) has a predetermined weight average molecular weight, the durability of the pressure-sensitive adhesive obtained by photocuring can be effectively improved.
Therefore, the pressure-sensitive adhesive composition of the present invention does not require seasoning, but can effectively suppress the occurrence of light leakage even when exposed to environmental changes.
The ene-thiol reaction is a reaction in which a radical is generated on a mercapto group by irradiation with active energy rays, and the mercapto group is added to an ethylenic double bond by the radical.
In the present invention, as is clear from the provisions thereof, the component (B1) and the component (B2) may be contained independently of the component (A) and the component (C), respectively. Both may be included.
That is, in the definition of the present invention, the pressure-sensitive adhesive composition containing “the following (A), (B1), (C) component” means a pressure-sensitive adhesive composition not containing the (B2) component, The pressure-sensitive adhesive composition containing “A), (B2), and (C) component” means a pressure-sensitive adhesive composition not containing the component (B1).
Therefore, a pressure-sensitive adhesive composition containing “the following (A), (B1), (C) component” defined by the present invention, and a pressure-sensitive adhesive containing “the following (A), (B2), (C) component” The pressure-sensitive adhesive composition containing the composition and “the following (A), (B1), (B2), (C) component” does not have overlapping portions.

Further, in constituting the pressure-sensitive adhesive composition of the present invention, the (A) component is a (meth) acrylic acid ester having a value in the range of 1 to 20 carbon atoms of the alkyl group as a structural unit, And a monomer having at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, and an amide group, and the copolymerization ratio (by weight) of 99.9: 0.1-80 : A value within the range of 20 is preferable.
By comprising in this way, not only can durability of the adhesive obtained by photocuring be improved more effectively, but also adhesive such as desired adhesiveness and storage elastic modulus without performing thermal crosslinking. The characteristics can be obtained more effectively.

Further, in constituting the pressure-sensitive adhesive composition of the present invention, the component (B1) is a (meth) acrylic acid ester having a value in the range of 1 to 20 carbon atoms of the alkyl group as a structural unit, and a side chain. And a monomer having an ethylenic double bond, and the copolymerization ratio (by weight) is preferably set to a value in the range of 99: 1 to 50:50.
By comprising in this way, the durability of the pressure-sensitive adhesive obtained by photocuring can be further effectively improved, and the pressure-sensitive adhesive has a desired pressure-sensitive adhesive force and storage elastic modulus without performing thermal crosslinking. The characteristics can be obtained more effectively.
In addition, the monomer which has an ethylenic double bond in a side chain shall also include the monomer which will finally have an ethylenic double bond in a side chain after copolymerization.

In forming the pressure-sensitive adhesive composition of the present invention, a (meth) acryloyl group or (meth) acryloyloxy group in which an ethylenic double bond in the side chain of the component (B1) is introduced through an isocyanate group It is preferable that
By comprising in this way, the ene-thiol reaction between (B1) component and (C) component can be performed more effectively.

In constituting the pressure-sensitive adhesive composition of the present invention, the component (B2) is a reactive isocyanurate compound having two or more (meth) acryloyl groups or (meth) acryloyloxy groups in one molecule. Is preferred.
By comprising in this way, not only can durability of the adhesive obtained by photocuring be improved more effectively, but the ene-thiol reaction between the (B2) component and the (C) component can be further improved. This can be done effectively.

In constituting the pressure-sensitive adhesive composition of the present invention, the component (C) is 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate), tris (3-mercaptopropionyloxyethyl) isocyanurate, trimethylolpropane tris3-mercaptopropionate, pentaerythritol tetrakis3-mercapto It is preferably at least one selected from the group consisting of propionate and dipentaerythritol hexa3-mercaptopropionate.
By comprising in this way, the ene-thiol reaction between (B) component and (C) component can be performed still more efficiently.

Moreover, in comprising the adhesive composition of this invention, while further containing a silane coupling agent as (D) component, content of the said (D) component is with respect to 100 weight part of (A) component. The value is preferably in the range of 0.001 to 10 parts by weight.
By comprising in this way, the adhesiveness of a polarizing plate and a liquid crystal cell can be improved effectively.

Further, in constituting the pressure-sensitive adhesive composition of the present invention, as the component (E), a photopolymerization initiator is further contained, and the content of the component (E) is set to 100 parts by weight of the component (A). The value is preferably less than 10 parts by weight.
By comprising in this way, photocuring speed can be improved, without inhibiting the ene-thiol reaction between (B) component and (C) component too much.

Another embodiment of the present invention is a pressure-sensitive adhesive obtained by curing a pressure-sensitive adhesive composition, and is formed through the following steps (1) to (3).
(1) The following (A), (B1), (C) component, or the following (A), (B2), (C) component, or the following (A), (B1), (B2), (C ) A step of preparing a pressure-sensitive adhesive composition containing the component (A) 100 parts by weight of a (meth) acrylic acid ester polymer having a weight average molecular weight of 200,000 to 2.5 million (B1) having a weight average molecular weight 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer having an ethylenic double bond in the side chain, which is 30,000 to 1,500,000,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule Part (2) Step of applying the pressure-sensitive adhesive composition to the release film (3) Step of irradiating the active energy ray at an irradiation dose in the range of 50 to 1000 mJ / cm ² Thus, while no seasoning is required, a pressure-sensitive adhesive that can effectively suppress the occurrence of light leakage while maintaining durability even when exposed to environmental changes is stably obtained on the release film. be able to.
Therefore, an adhesive can be efficiently laminated on an optical film such as a polarizing plate.
The irradiation amount may be referred to as a light amount.
In the following description, curing with active energy rays may be abbreviated as “photocuring”, which is a concept included therein.

Moreover, when comprising the adhesive of this invention, it is preferable to make the storage elastic modulus G 'in 23 degreeC into the value within the range of 0.01-0.8 MPa.
By comprising in this way, generation | occurrence | production of light leakage can be suppressed more effectively even if it is a case where it is a case where it is exposed to an environmental change.

Moreover, another aspect of the present invention is an optical film comprising a pressure-sensitive adhesive layer containing the above-mentioned pressure-sensitive adhesive on a film substrate, and the thickness of the pressure-sensitive adhesive layer is in the range of 1 to 100 μm. It is an optical film characterized by having a value.
That is, by comprising in this way, desired adhesive properties, such as adhesive force and storage elastic modulus, can be exhibited more stably.

In constituting the optical film of the present invention, the film substrate is preferably a polarizing plate.
Even if it is a case where it comprises in this way, generation | occurrence | production of light leakage can be suppressed effectively.

Fig.1 (a)-(e) is the schematic provided in order to demonstrate the usage method, such as an adhesive composition, and the manufacturing method of an optical film. FIG. 2 is a diagram for explaining an evaluation method of light leakage. FIG. 3 is a diagram for explaining the light leakage in the first embodiment. FIG. 4 is a diagram provided for explaining the light leakage in the comparative example 5.

[First embodiment]
In the first embodiment of the present invention, the following components (A), (B1), (C), or the following components (A), (B2), (C), or the following components (A), (B1) , (B2), (C) component is contained, It is an adhesive composition characterized by the above-mentioned.
(A) The weight average molecular weight is 200,000-2,500,000 (meth) acrylic acid ester polymer 100 parts by weight (B1) The weight average molecular weight is 30,000-1,500,000, and has an ethylenic double bond in the side chain 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule Part That is, it is the pressure-sensitive adhesive composition 1 used in the embodiment exemplified in FIGS.
Hereinafter, a first embodiment of the present invention will be specifically described with reference to the drawings as appropriate.

1. (A) Component (1) Type The component (A) is a (meth) acrylic acid ester polymer, which is a so-called acrylic polymer.
Moreover, as a difference from the component (B1) described later, the component (A) has a feature that it does not have an ethylenic double bond in the side chain and is non-reactive with respect to radicals.
Therefore, since the component (A) is not subjected to photocrosslinking, it contributes to improvement in adhesive properties and durability.
In the present invention, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester.

The (meth) acrylic acid ester as the constituent unit of the component (A) is not particularly limited, and conventionally known ones can be appropriately used.
For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate and (meth) acrylic acid It is preferably derived from at least one such as stearyl.

Moreover, it is also preferable to use the monomer which has a functional group in a molecule | numerator as a monomer which comprises (A) component.
For example, the functional group preferably contains at least one of a hydroxyl group, a carboxyl group, an amino group, and an amide group. Specific examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (Meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 2-hydroxybutyl, (meth) acrylic acid 3-hydroxybutyl, (meth) acrylic acid 4-hydroxybutyl; Acrylamides such as acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, Monomethyl (meth) acrylate Monoalkylaminoalkyl (meth) acrylates such as minopropyl and monoethylaminopropyl (meth) acrylate; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid, etc. Can be mentioned.

Moreover, (A) component has (meth) acrylic acid ester (a1) whose carbon number of an alkyl group is a value within the range of 1-20 as a structural unit, a hydroxyl group, a carboxyl group, an amino group, and in a molecule | numerator. A monomer (a2) having at least one selected from the group consisting of amide groups, and the copolymerization ratio (a1: a2) (weight basis) of 99.9: 0.1-80: A value within the range of 20 is preferred.
This is because the component (A) is configured in this way, whereby the durability of the pressure-sensitive adhesive obtained by photocuring can be improved more effectively, and the desired pressure-sensitive adhesive can be obtained without thermal crosslinking. This is because adhesive properties such as force and storage modulus can be obtained more effectively.

That is, when the carbon number of the alkyl group in the (meth) acrylic acid ester is larger than 20, the storage elastic modulus becomes excessively low and the durability may be insufficient. On the other hand, if the carbon number of the alkyl group is excessively small, the storage elastic modulus becomes excessively large and the durability may be insufficient.
Therefore, the carbon number of the alkyl group in the (meth) acrylic acid ester is more preferably a value within the range of 2-18, and even more preferably a value within the range of 3-12.

Further, when the copolymerization ratio (a1: a2) exceeds 99.9: 0.1, the compatibility with other components decreases, and the interaction with an auxiliary agent such as a silane coupling agent. This is because the strength may be weakened and the durability may be easily lowered. On the other hand, when the copolymerization ratio (a1: a2) is less than 80:20, the compatibility with other components is lowered, and the optical physical properties and durability are likely to be lowered.
From such a viewpoint, the alkyl group has a (meth) acrylic acid ester (a1) having a value in the range of 1 to 20 carbon atoms and a group consisting of a hydroxyl group, a carboxyl group, an amino group, and an amide group in the molecule. More preferably, the copolymerization ratio (a1: a2) (by weight) of the monomer (a2) having at least one selected monomer is set to a value within the range of 99: 1 to 90:10, 98 More preferably, the value is within the range of 5: 1.5 to 95: 5.
In addition, the (meth) acrylic acid ester whose carbon number of the alkyl group is in the range of 1 to 20 is, for example, a hydroxyl group, a carboxyl group, an amino group and (Meth) acrylic acid ester having no amide group is meant.
Moreover, the copolymerization ratio mentioned above shows the theoretical value computed from the preparation amount of the monomer which is each structural unit.
Further, the form of copolymerization is not particularly limited, and any of random, block, and graft copolymers may be used.

(2) Weight average molecular weight (A) Let the weight average molecular weight of a component be the value within the range of 200,000-2,500,000.
The reason for this is that when the weight average molecular weight of the component (A) is less than 200,000, the durability when exposed to environmental changes becomes insufficient, and the occurrence of light leakage is effectively suppressed. This may be difficult. On the other hand, when the weight average molecular weight of the component (A) exceeds 2.5 million, the viscosity of the pressure-sensitive adhesive composition becomes too high, and the processability may be impaired.
Therefore, the weight average molecular weight of the component (A) is preferably set to a value in the range of 500,000 to 2,200,000, and more preferably set to a value in the range of 1,000,000 to 2,000,000.
In addition, this weight average molecular weight can be measured by the gel permeation chromatography (GPC) method by polystyrene conversion.
In addition, (A) component may be used individually by 1 type, and may use together 2 or more types from which a monomer component and molecular weight differ.

2. Component (B) Component (B) is a predetermined reactive (meth) acrylic acid ester polymer as component (B1), or a predetermined polyene compound as component (B2), or (B1) component and (B2) ) A combination of ingredients.
Hereinafter, the component (B1) and the component (B2) will be described.

(1) (B1) component (1) -1 type (B1) component is a reactive (meth) acrylic acid ester polymer having an ethylenic double bond in the side chain, and is a so-called reactive acrylic polymer. .
The component (B1) is subjected to photocrosslinking by an ene-thiol reaction with the component (C), and contributes to improving durability by increasing the cohesive force of the pressure-sensitive adhesive.

Moreover, (B1) component can be obtained as follows.
That is, first, a copolymer of (meth) acrylic acid ester and a monomer having a functional group such as a hydroxyl group or a carboxyl group in the molecule is prepared.
Next, a compound having an ethylenic double bond and an isocyanate group, an epoxy group, or the like in the molecule is prepared, and a hydroxyl group, a carboxyl group, or the like of the prepared copolymer is provided via the isocyanate group or the epoxy group. (B1) component can be obtained by carrying out addition reaction with respect to the substituent of.
Further, the ratio of the addition reaction is preferably set to a value within the range of 50 to 100 mol% of the monomer constituting the copolymer and having a functional group such as a hydroxyl group or a carboxyl group in the molecule. It is more preferable to set it as the value within the range of -95 mol%, and it is further more preferable that it is the value within the range of 70-90 mol%.
In addition, when the substituent in the copolymer is a carboxyl group, an isocyanate group or an epoxy group, and when the substituent in the copolymer is a hydroxyl group, the isocyanate group, and the substituent in the copolymer is an amino group or a substituted amino group. In the case of a group, it is preferable to carry out an addition reaction of a compound having an ethylenic double bond in the molecule through an isocyanate group.
The (meth) acrylic acid ester and the monomer having a functional group in the molecule can be the same as those in the component (A).

In addition, the component (B1) includes, as a structural unit, a (meth) acrylic acid ester (b1) whose alkyl group has a value in the range of 1 to 20 carbon atoms and a single unit having an ethylenic double bond in the side chain. It is preferable that the copolymer (b1: b2) (weight basis) is a value within the range of 99: 1 to 50:50.
The reason for this is that the (B1) component is constituted in this way, whereby the durability of the pressure-sensitive adhesive obtained by photocuring can be further effectively improved, and the desired pressure-sensitive adhesive can be obtained without performing thermal crosslinking. This is because the pressure-sensitive adhesive properties such as property and storage elastic modulus can be obtained more effectively.
In addition, the monomer which has an ethylenic double bond in a side chain shall also include the monomer which will finally have an ethylenic double bond in a side chain after copolymerization.

That is, when the carbon number of the alkyl group in the (meth) acrylic acid ester is larger than 20, the storage elastic modulus becomes excessively small and durability may be insufficient. On the other hand, if the carbon number of the alkyl group is excessively small, the storage elastic modulus becomes excessively large and the durability may be insufficient.
Therefore, the carbon number of the alkyl group in the (meth) acrylic acid ester is more preferably a value within the range of 2-18, and even more preferably a value within the range of 3-12.

Further, when the copolymerization ratio (b1: b2) exceeds 99: 1, the ene-thiol bond between the component (B1) and the component (C) becomes excessively small, and sufficient durability and desired This is because it may be difficult to obtain adhesive properties. On the other hand, when the copolymerization ratio (b1: b2) is less than 50:50, the number of ene-thiol bonds between the (B1) component and the (C) component is excessively increased to obtain desired pressure-sensitive adhesive properties. This may be difficult.
Therefore, copolymerization of (meth) acrylic acid ester (b1) having an alkyl group with a carbon number in the range of 1 to 20 and a monomer (b2) having an ethylenic double bond in the side chain. The ratio (b1: b2) (weight basis) is more preferably set to a value within the range of 95: 5 to 60:40, and further preferably set to a value within the range of 90:10 to 70:30.
In addition, the copolymerization ratio mentioned above shows the theoretical value calculated from the preparation amount.
More specifically, the amount of the monomer having an ethylenic double bond in the side chain is determined by the amount charged when the ethylenic double bond is added to the monomer having a substituent, and (meta ) Theoretical value calculated from the charged amount when copolymerizing an acrylate ester and a monomer having an ethylenic double bond in the side chain.

Moreover, it is preferable that the ethylenic double bond in the side chain of (B1) component is the (meth) acryloyl group or (meth) acryloyloxy group introduce | transduced via the isocyanate group.
This is because the ene-thiol reaction between the component (B1) and the component (C) can be performed more effectively by configuring in this way.
That is, if it is a (meth) acryloyl group or a (meth) acryloyloxy group, since it has moderate reactivity, the ene-thiol reaction mentioned above can be advanced efficiently.
More specifically, acryloyloxyethyl isocyanate, acryloyloxypropyl isocyanate, methacryloyloxyethyl isocyanate, methacryloyloxypropyl isocyanate, and the like are preferably added to the hydroxyl group of the copolymer prepared in advance. .
In addition, it is preferable to perform this addition reaction for about 6 to 48 hours at the temperature of 25-60 degreeC, for example.
If necessary, it is also preferable to use an organic tin compound such as dibutyltin dilaurate, a substituted amine compound, or the like as a catalyst.

(1) -2 Weight average molecular weight The weight average molecular weight of the component (B1) is set to a value within the range of 30,000 to 1,500,000.
The reason for this is that when the weight average molecular weight of the component (B1) is less than 30,000, the durability when exposed to environmental changes becomes insufficient, and the occurrence of light leakage is effectively suppressed. This may be difficult. On the other hand, when the weight average molecular weight of the component (B1) exceeds 1.5 million, it may be difficult to obtain desired adhesive properties such as adhesive strength and storage elastic modulus without performing thermal crosslinking. Because there is.
Therefore, the weight average molecular weight of the component (B1) is preferably set to a value in the range of 100,000 to 1,200,000, and more preferably set to a value in the range of 300,000 to 1,000,000.
In addition, this weight average molecular weight can be measured by the gel permeation chromatography (GPC) method by polystyrene conversion.

(1) -3 Content The content of the component (B1) is set to a value within the range of 1 to 100 parts by weight with respect to 100 parts by weight of the component (A).
The reason for this is that when the content of the component (B1) is less than 1 part by weight, the ene-thiol reaction between the component (B1) and the component (C) becomes insufficient, and the cohesive force decreases. It is because it may become easy. On the other hand, when the content of the component (B1) exceeds 100 parts by weight, the ene-thiol reaction between the component (B1) and the component (C) becomes excessive, and adhesiveness and durability are reduced. It is because it may become easy to do.
Therefore, it is more preferable to set the content of the component (B1) to a value within the range of 2 to 70 parts by weight with respect to 100 parts by weight of the component (A), and a value within the range of 3 to 50 parts by weight. More preferably.
In addition, (B1) component may be used individually by 1 type, and may use together 2 or more types from which a monomer component, molecular weight, etc. differ.

(2) (B2) Component (2) -1 Types The (B2) component is a polyene compound having two or more ethylenic double bonds in one molecule, and is a so-called polyene compound.
The component (B2) is subjected to photocrosslinking by an ene-thiol reaction with the component (C), and contributes to improving durability by increasing the cohesive force of the pressure-sensitive adhesive.
In addition, although the component (B1) is also a compound having the component (B2) in that it is a compound having two or more ethylenic double bonds in one molecule, the component (B2) is a monomer or an oligomer. On the other hand, the difference is that the component (B1) is a polymer.
More specifically, the component (B2) is a polyene compound having a molecular weight of less than 30,000.

  In addition, the component (B2) is not particularly limited except the contents described above, but from the viewpoint of compatibility and reactivity with other components, a (meth) acryloyl group or a (meth) acryloyloxy group is used. Preferably, it is a monomer or oligomer polyfunctional (meth) acrylate compound.

Moreover, as a polyfunctional (meth) acrylate compound which is a monomer, a molecular weight less than 1000 is used suitably.
Examples of such compounds include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) phosphate ) Bifunctional types such as acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate; trimethylolpropane tri (meth) acrylate, dipentaerythritol Li (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, bis (acrylic) (Roxyethyl) hydroxyethyl isocyanurate, isocyanuric acid ethylene oxide modified diacrylate, isocyanuric acid ethylene oxide modified triacrylate, ε-caprolactone modified tris (acryloxyethyl) isocyanurate, etc .; diglycerin tetra (meth) acrylate, Tetrafunctional type such as pentaerythritol tetra (meth) acrylate; propionic acid modified dipentaerythritol penta (meth) acrylate Any pentafunctional type; hexafunctional types such as dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, and the like.

In particular, the skeleton structure preferably has a cyclic structure.
Examples of such polyfunctional (meth) acrylate monomers include di (acryloxyethyl) isocyanurate, tris (acryloxyethyl) isocyanurate, bis (acryloxyethyl) hydroxyethyl isocyanurate, isocyanuric acid ethylene oxide modification. Those having isocyanurate structures such as diacrylate, isocyanuric acid ethylene oxide modified triacrylate, ε-caprolactone modified tris (acryloxyethyl) isocyanurate, dimethylol dicyclopentane diacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate , Tricyclodecane dimethanol acrylate, neopentyl glycol modified trimethylolpropane diacrylate, adamantane diacrylate, etc. It is.
In particular, in the case of a compound having an isocyanurate structure, the crosslinking density in the photocrosslinking of the component (B2) and the component (C) can be adjusted to a more suitable range, and the durability of the pressure-sensitive adhesive obtained by photocuring Can be improved more effectively, and further, the compatibility of the component (B2) with the component (A) can be further improved to obtain more excellent transparency, which is preferable.
Among them, those having a trifunctional type and an isocyanurate structure are more preferable because they have little influence on optical properties and exhibit excellent effects in improving durability and adhesion to an adherend.
In the present invention, these polyfunctional (meth) acrylate monomers may be used alone or in combination of two or more.

Examples of the polyfunctional (meth) acrylate compound that is an oligomer include polyester acrylates having a weight average molecular weight of 20,000 or less, epoxy acrylates, urethane acrylates, polyether acrylates, polybutadiene acrylates, and silicone acrylates. It is done.
Here, as the polyester acrylate oligomer, for example, by esterifying the hydroxyl group of a polyester oligomer having a hydroxyl group at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, or It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid.
The epoxy acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. A carboxyl-modified epoxy acrylate oligomer obtained by partially modifying this epoxy acrylate oligomer with a dibasic carboxylic acid anhydride can also be used.
The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol with polyisocyanate with (meth) acrylic acid. It can be obtained by esterifying the hydroxyl group of ether polyol with (meth) acrylic acid.
Moreover, the weight average molecular weight of the acrylate oligomer described above is a value in terms of standard polystyrene measured by GPC method, and is preferably 20,000 or less, more preferably 1000 to 10,000, and still more preferably 3,000 to 5, 000 is selected.
In addition, these oligomers may be used individually by 1 type, and may be used in combination of 2 or more type.

  Further, the component (B2) may be other than the polyfunctional (meth) acrylate compound described above, and examples thereof include a polyfunctional (meth) allyl compound and a polyfunctional vinyl compound.

  For example, polyfunctional (meth) allyl compounds include o-, m- or p-di (meth) allyl phthalate, trimethylolpropane di (meth) allyl ether, pentaerythritol tri (meth) allyl ether, tri (meth). Examples include allyl isocyanurate, di (meth) allyl bisphenol A, and di (meth) allyl bisphenol.

  Examples of the polyfunctional vinyl compound include vinyl ethers such as triethylene glycol divinyl ether, cyclohexane dimethanol divinyl ether, and cyclohexanediol divinyl ether, and divinylbenzene.

(2) -2 Content In addition, the content of the component (B2) is set to a value in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the component (A).
The reason for this is that when the content of the component (B2) is less than 1 part by weight, the ene-thiol bond between the component (B2) and the component (C) is excessively decreased and exposed to environmental changes. This is because it may be difficult to obtain durability in some cases. On the other hand, when the content of the component (B2) exceeds 50 parts by weight, the ene-thiol bond between the component (B2) and the component (C) becomes excessive, and the desired content can be obtained without performing thermal crosslinking. This is because it may be difficult to obtain adhesive properties such as adhesive strength and storage elastic modulus.
From such a viewpoint, the content of the component (B2) is more preferably set to a value within the range of 2 to 40 parts by weight with respect to 100 parts by weight of the component (A), and the range of 3 to 30 parts by weight. More preferably, the value is within the range.

When the component (B2) is used in combination with the component (B1), the content of the component (B2) is in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the component (A). It is preferable to use a value.
This is because when the component (B2) is used in combination with the component (B1), if the content of the component (B2) is less than 1 part by weight, the crosslinking reaction does not proceed sufficiently, and the cohesive force This is because there is a case that becomes insufficient. On the other hand, when the content of the component (B2) exceeds 50 parts by weight, the crosslinking reaction proceeds excessively, and the adhesive properties and durability may be lowered.
Therefore, when the component (B2) is used in combination with the component (B1), the content of the component (B2) is in the range of 2 to 40 parts by weight with respect to 100 parts by weight of the component (A). More preferably, the value is more preferably in the range of 3 to 30 parts by weight.

3. (C) Component (1) Type The component (C) is a polythiol compound having two or more mercapto groups in one molecule.
The component (C) is subjected to photocrosslinking by an ene-thiol reaction with the component (B), and contributes to improving durability by increasing the cohesive force of the pressure-sensitive adhesive.

  Further, the component (C) is not particularly limited, and for example, diglycol dimercaptan, triglycol dimercaptan, tetraglycol dimercaptan, thiodiglycol dimercaptan, thiotriglycol dimercaptan, thiotetraglycol dimercaptan , Tris (mercaptopropyl) isocyanurate, ethanedithiol, propanedithiol, hexamethylenedithiol, decamethylenedithiol, tolylene-2,4-dithiol, xylylenedithiol, trimethylolpropane tris-β-mercaptopropionate, o-, m-, p-xylenedithiol, ethylene glycol bisthioglycolate, butanediol bisthioglycolate, hexanediol bisthioglycolate, ethylene glycol bis Opropionate, butanediol bisthiopropionate, trimethylolpropane tristhiopropionate, pentane erythritol tetrakisthiopropionate, trihydroxyethyl triisocyanuric acid tristhiopropionate, tris [(3-mercaptopropionyloxy) ethyl ] Isocyanurate, pentaerythritol tetrakis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), dipentaerythritol hexa (3-mercaptopropionate), diethylene glycol bis (3-mercaptopropionate) Nate), 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazi -2,4,6 (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate) and the like.

Moreover, among the above-mentioned, especially 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate), tris (3-mercaptopropionyloxy) ethyl isocyanurate, trimethylolpropane tris3-mercaptopropionate, pentaerythritol tetrakis 3-mercaptopropionate and dipentaerythritol hexa3-mercaptopropio It is preferably at least one selected from the group consisting of nates.
This is because, with these polythiol compounds, the ene-thiol reaction between the (B) component and the (C) component can be more effectively performed.
That is, it has three or more reactive groups containing a thiol group and exhibits appropriate reactivity.

(2) Content Further, the content of the component (C) is set to a value within the range of 0.01 to 50 parts by weight with respect to 100 parts by weight of the component (A).
The reason for this is that when the content of the component (C) is less than 0.01 parts by weight, the ene-thiol bond between the component (B) and the component (C) is excessively reduced, resulting in an environmental change. This is because it may be difficult to obtain durability when exposed. On the other hand, when the content of the component (C) exceeds 50 parts by weight, the ene-thiol bond between the component (B) and the component (C) becomes excessive and desired without performing thermal crosslinking. This is because it may be difficult to obtain adhesive properties such as adhesive strength and storage modulus.
Therefore, it is more preferable to set the content of the component (C) to a value within the range of 0.05 to 40 parts by weight with respect to 100 parts by weight of the component (A), and a range of 0.1 to 30 parts by weight. More preferably, the value is within the range.

4). (D) Type of component (1) Furthermore, it is also preferable to contain a so-called silane coupling agent as component (D).
Such component (D) contributes to effectively improving the adhesion between an object made of glass such as a liquid crystal cell and an optical film such as a polarizing plate.
In addition, the component (D) is an organosilicon compound having at least one alkoxysilyl group in the molecule, has good compatibility with the pressure-sensitive adhesive composition, and has light transmittance. Is preferred.

  More specifically, vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, etc. are used. It is preferable.

(2) Content Moreover, it is preferable to make content of (D) component into the value within the range of 0.001-10 weight part with respect to 100 weight part of (A) component.
This is because, when the content of the component (D) is less than 0.001 part by weight, it is difficult to sufficiently exert the effect of improving the adhesion between the polarizing plate and the liquid crystal cell. This is because there is a case of becoming. On the other hand, when the content of the component (D) exceeds 10 parts by weight, the tackiness and durability may be lowered.
From such a viewpoint, the content of the component (D) is more preferably set to a value within the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the component (A). More preferably, the value is within the range of parts by weight.

5). Photopolymerization initiator (1) type Furthermore, it is also preferable to contain a so-called photopolymerization initiator as the component (E).
This (E) component contributes to improving the photocuring speed.
Examples of the component (E) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2- Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) Phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-die Tylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo [2-hydroxy-2-methyl-1 [4- (1-methylvinyl) phenyl] propanone], 2 4,6-trimethylbenzoyl-diphenyl-phosphine oxide or the like is preferably used.

(2) Content Moreover, it is preferable to make content of (E) component into a value less than 10 weight part with respect to 100 weight part of (A) component.
The reason for this is that when the content of the component (E) is a value of 10 parts by weight or more, the ene-thiol reaction between the component (B) and the component (C) is excessively inhibited and exposed to environmental changes. This is because it may be difficult to obtain durability and predetermined adhesive properties in some cases. On the other hand, when the content of the component (E) is excessively reduced, it is difficult to obtain the effect of improving the photocuring rate.
Accordingly, the content of the component (E) is more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the component (A), and the range of 0.3 to 2 parts by weight. More preferably, the value is within the range.
As shown in the examples, it has been confirmed that even when the component (E) is not contained at all, it is possible to sufficiently obtain durability and predetermined adhesive properties when exposed to environmental changes.
Therefore, from the viewpoint of suppressing the inhibition of the ene-thiol reaction, it is also preferable not to contain the component (E) at all.

6). Antistatic agent Moreover, it is also preferable that the adhesive composition of this invention contains an antistatic agent.
The reason for this is that, by including an antistatic agent, static electricity is generated when it is necessary to peel a polarizing plate with a pressure-sensitive adhesive layer, etc., onto an adherend, such as a liquid crystal cell, and then peel off due to a sticking error, etc. It is because it can suppress effectively.
As a result, it is possible to stably prevent dust from being easily attached to the surface of the polarizing plate, the liquid crystal alignment is easily disturbed, and the electrostatic breakdown of the peripheral circuit element is easily caused. This is because it can.

(1) Type As the type of the antistatic agent, it is preferable to use potassium / fluorine-containing sulfonylimide salt and / or lithium / fluorine-containing sulfonylimide salt.
This is because these compounds can effectively exhibit excellent antistatic properties over a long period of time.
In particular, even when exposed to a high temperature environment for a long time, bleed from the pressure-sensitive adhesive layer obtained after photocuring can be suppressed, and effective prevention of adhesive strength and durability deterioration in a specified environment is also possible. This is because it can be done.
Further, preferred examples of the potassium / fluorine-containing sulfonylimide salt include potassium bis (fluorosulfonyl) imide, potassium bis (trifluoromethylsulfonyl) imide, potassium bis (pentafluoroethylsulfonyl) imide and the like.
Further, preferred examples of the lithium / fluorine-containing sulfonylimide salt include lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethylsulfonyl) imide, lithium bis (pentafluoroethylsulfonyl) imide, and the like.

(2) Content Further, the content of the antistatic agent is set to a value in the range of 0.05 to 15 parts by weight with respect to 100 parts by weight of the (meth) acrylic acid ester polymer as the component (A). It is preferable.
The reason for this is that when the content of the antistatic agent is less than 0.05 parts by weight, the antistatic property is not sufficiently imparted to the pressure sensitive adhesive obtained by photocuring the pressure sensitive adhesive composition. This is because it may be difficult to stably suppress the occurrence. On the other hand, when the content of the antistatic agent exceeds 15 parts by weight, the adhesive strength in the pressure-sensitive adhesive obtained by photocuring the pressure-sensitive adhesive composition and the durability under predetermined conditions may be excessively reduced. Because.
Therefore, the content of the antistatic agent is more preferably set to a value within the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic acid ester polymer as the component (A). More preferably, the value is in the range of 2 to 4 parts by weight.

(3) Dispersion aid Further, in order to improve the dispersibility of the antistatic agent in the pressure-sensitive adhesive composition and the pressure-sensitive adhesive obtained by curing it, it is preferable to further add a dispersion aid.
In addition, as the dispersion aid, polyoxyethylene glycol-polyoxypropylene glycol block copolymer or the like can be used, but it is preferable to use alkylene glycol dialkyl ether.
The reason for this is that if it is an alkylene glycol dialkyl ether, the antistatic property such as potassium (or lithium) / fluorine-containing sulfonylimide salt can be effectively improved, and the dispersion aid itself is an optical pressure-sensitive adhesive. This is because bleeding can also be effectively suppressed.

Specific examples of the alkylene glycol dialkyl ether include octaethylene glycol butyl ether, octaethylene glycol diethyl ether, octaethylene glycol dimethyl ether, hexaethylene glycol dibutyl ether, hexaethylene glycol diethyl ether, hexaethylene glycol dimethyl ether, tetraethylene glycol dibutyl ether. , Tetraethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dimethyl ether, etc., or a combination thereof.
Of these, tetraethylene glycol diethyl ether and tetraethylene glycol dimethyl ether are particularly preferable.
In addition, as an addition ratio, it is preferable to make the addition ratio (molar ratio) of an antistatic agent and alkylene glycol dialkyl ether into the ratio in the range of 30: 70-70: 30, and 40: 60-60: A ratio in the range of 40 is more preferable, and a ratio in the range of 45:55 to 55:45 is more preferable.

7). Additives As additives, it is also preferable to contain tackifiers, antioxidants, ultraviolet absorbers, near infrared absorbers, light stabilizers, softeners, fillers and the like.
In that case, although depending on the type of the additive, the content is preferably set to a value in the range of 0.1 to 20 parts by weight with respect to 100 parts by weight of the component (A).
In addition, since the adhesive composition of this invention can exhibit sufficient performance only by photocrosslinking, addition of a thermal crosslinking agent is unnecessary.
Therefore, the present invention does not require a seasoning period.

[Second Embodiment]
2nd Embodiment of this invention is an adhesive, Comprising: It is an adhesive formed through the following process (1)-(3).
(1) The following (A), (B1), (C) component, or the following (A), (B2), (C) component, or the following (A), (B1), (B2), (C ) A step of preparing a pressure-sensitive adhesive composition containing the component (A) 100 parts by weight of a (meth) acrylic acid ester polymer having a weight average molecular weight of 200,000 to 2.5 million (B1) having a weight average molecular weight 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer having an ethylenic double bond in the side chain, which is 30,000 to 1,500,000,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule Part (2) Step of applying the pressure-sensitive adhesive composition to the release film (3) Step of irradiating active energy rays at an irradiation dose in the range of 50 to 1000 mJ / cm ² Hereinafter, the second of the present invention Embodiments will be specifically described with reference to the drawings as appropriate.

1. Step (1) (Preparation step of pressure-sensitive adhesive composition)
Step (1) is the following (A), (B1), (C) component, or the following (A), (B2), (C) component, or the following (A), (B1), (B2) (C) It is the process of preparing the adhesive composition characterized by containing a component.
(A) 100 parts by weight of (meth) acrylic acid ester polymer having a weight average molecular weight of 200,000 to 2,500,000 (B1) having a weight average molecular weight of 30,000 to 1,500,000 and having an ethylenic double bond in the side chain 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule That is, the pressure-sensitive adhesive composition having such a composition does not require seasoning when cured, but can effectively suppress the occurrence of light leakage even when exposed to environmental changes. It is because it can be obtained.
In addition, about the specific content of this adhesive composition, since it demonstrated in 1st Embodiment, it abbreviate | omits.

2. Step (2) (Applying step of pressure-sensitive adhesive composition)
Step (2) is a step of applying the pressure-sensitive adhesive composition 1 to the release film 2 as shown in FIG.
As such a release film, for example, a release layer such as a silicone resin is applied to a polyester film such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate, or a polyolefin film such as polypropylene or polyethylene to provide a release layer. Things.
In addition, it is preferable that the thickness of this peeling film shall be the value within the range of 20-150 micrometers normally.

Moreover, as a method of applying the pressure-sensitive adhesive composition on the release film, for example, using a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, etc., if necessary, It is preferable to dry after apply | coating the adhesive composition which added the solvent, and forming a coating film.
At this time, the thickness of the coating film of the pressure-sensitive adhesive composition is preferably set to a value in the range of 1 to 100 μm during drying.
Moreover, as drying conditions, it is preferable to set it as the range for 10 seconds-10 minutes normally at 50-150 degreeC.
The solvent is preferably, for example, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, ethyl isobutyl ketone, methyl alcohol, ethyl alcohol, isopropyl alcohol, etc., and the concentration of the pressure-sensitive adhesive composition when the solvent is added is A value in the range of 5 to 30% by weight is preferred.

Moreover, as shown in FIG.1 (b), after apply | coating the adhesive composition 1 with respect to the peeling film 2 and making it dry, the film base material 101 can be laminated | stacked on the adhesive composition 1. FIG. preferable.
This is because, in such a laminated state, the pressure-sensitive adhesive composition can be photo-cured to proceed with photo-curing without being affected by oxygen in the air and to stably produce a film with a pressure-sensitive adhesive layer. Because.

Moreover, as shown in FIG.1 (e), after apply | coating the adhesive composition 1 with respect to the peeling film 2 and making it dry, another peeling film 2 from which peeling force differs is further used as the adhesive composition 1. It is preferable to laminate them on top.
Such an embodiment is not only required when the pressure-sensitive adhesive is to be transported alone, for example, because the production of the pressure-sensitive adhesive and the use of the pressure-sensitive adhesive are performed at different locations. It is also preferable from the point that photocuring can proceed without being influenced by oxygen in the inside.
In addition, by providing a predetermined difference in the peeling force between the two peeling films, it is possible to prevent the adhesive from partially following when the peeling film having the lower peeling force is peeled off. Is also preferable.

3. Process (3) (light irradiation process with respect to adhesive composition)
In the step (3), as shown in FIG. 1 (c), the active energy ray is irradiated at an irradiation dose in the range of 50 to 1000 mJ / cm ² and applied to the release film 2. In this process, 1 is photocured to form an adhesive 10.
Examples of such active energy rays include ultraviolet rays and electron beams.
Further, ultraviolet rays can be obtained with a high-pressure mercury lamp, electrodeless lamp, xenon lamp or the like, and electron rays can be obtained with an electron beam accelerator or the like.

Although characterized by an active energy ray at dose in the range of 50~1000mJ / cm ^2, this is because, when the irradiation amount of the active energy ray is below 50 mJ / cm ^2, It is difficult to sufficiently perform the ene-thiol reaction between the component (B) and the component (C), and it is difficult to obtain durability and desired adhesive properties when exposed to environmental changes. This is because there may be cases. On the other hand, when the irradiation amount of the active energy ray becomes a value exceeding 1000 mJ / cm ² , there is a risk of destroying the adhesive or the substrate.
Therefore, it is more preferable to irradiate the adhesive composition with an active energy ray at an irradiation dose in the range of 100 to 700 mJ / cm ² , and further to irradiate with an irradiation dose of 120 to 500 mJ / cm ^2. preferable.
Moreover, it is preferable to perform irradiation of an active energy ray from the peeling film 2 side, as shown in FIG.1 (c).
This is because, without damaging the optical films such as polarizing plates, because the efficient irradiation can be performed.

4). Adhesive Properties (1) Storage Elastic Modulus Further, it is preferable that the storage elastic modulus G ′ of the adhesive at 23 ° C. is set to a value within the range of 0.01 to 0.8 MPa.
The reason for this is that by setting the storage elastic modulus G ′ within such a range, the occurrence of light leakage can be more effectively suppressed even when exposed to environmental changes.
That is, when the storage elastic modulus G ′ is less than 0.01 MPa, it may be difficult to sufficiently suppress the occurrence of light leakage when exposed to environmental changes. On the other hand, when the storage elastic modulus G ′ is a value exceeding 0.8 MPa, it may be difficult to obtain a desired adhesive force or the like.
Accordingly, the storage elastic modulus G ′ at 23 ° C. is more preferably set to a value within the range of 0.05 to 0.75 MPa, and further preferably set to a value within the range of 0.1 to 0.7 MPa.
In addition, about the measuring method of storage elastic modulus G ', it describes in an Example.

(2) Adhesive strength Moreover, it is preferable to make the adhesive strength of an adhesive into the value within the range of 0.1-50 N / 25mm.
The reason for this is that if the adhesive strength is less than 0.1 N / 25 mm, it may be difficult to sufficiently suppress the occurrence of light leakage when exposed to environmental changes. On the other hand, when the adhesive strength exceeds 50 N / 25 mm, the reworkability may be excessively lowered.
Accordingly, the adhesive strength of the adhesive is more preferably set to a value within the range of 0.5 to 40 N / 25 mm, and further preferably set to a value within the range of 1 to 30 N / 25 mm.
In addition, about the measuring method of adhesive force, it describes in an Example.

(3) Seasoning-less property Further, the storage elastic modulus G ′ (23 ° C.) after 1 day from the production of the pressure-sensitive adhesive (after irradiation with active energy rays) is the storage elastic modulus G ′ (23 ° C. after 7 days from the production). C.) is preferably 70% or more.
This is because when the rate of change is less than 70%, it is determined that a seasoning period for stabilizing the pressure-sensitive adhesive characteristics is necessary because the change in the pressure-sensitive adhesive characteristics over time is large. .
For the same reason, the difference between the adhesive strength after 1 day from the production and the adhesive strength after 7 days from the production is preferably less than 5 N / 25 mm, and preferably less than 3 N / 25 mm. More preferably, the value is more preferably 0 to less than 2 N / 25 mm.

[Third embodiment]
3rd Embodiment of this invention is an optical film formed by providing the adhesive layer containing the adhesive which is 2nd Embodiment on a film base material, Comprising: The thickness of an adhesive layer is 1-100 micrometers. It is an optical film characterized by setting it as the value within the range.
Hereinafter, a third embodiment of the present invention will be specifically described with reference to FIG.

1. Film substrate The film substrate 101 in the optical film 100 of the present invention is not particularly limited as long as it is used for an optical film.
Examples thereof include optical films used for liquid crystal displays, such as polarizing plates, polarizing layer protective films, viewing angle widening films, antiglare films, and retardation plates.
In particular, the optical film of the present invention can effectively suppress the occurrence of light leakage even when the film substrate is a polarizing plate.
Examples of the material for the film substrate include polyvinyl alcohol, polyethylene terephthalate, triacetyl cellulose, polycarbonate, liquid crystal polymer, cycloolefin, polyimide, polyamide, polyamideimide, polyphenylene ether, polyether ketone, polyether ether ketone, poly Examples include sulfone, polyether sulfone, polyphenylene sulfide, polyarylate, acrylic resin, alicyclic structure-containing polymer, and aromatic polymer.
Further, since the pressure-sensitive adhesive in the present invention can adhere to a polarizer or the like with high durability, the polarizer itself produced by stretching an iodine-containing polyvinyl alcohol resin that is a raw material of the polarizing plate is also the optical film of the present invention. 100 can be the film substrate 101.
The same applies to a polarizer in which one side of the polarizer is covered with a protective film such as triacetylcellulose or polyethylene terephthalate.

Moreover, there is no restriction | limiting in particular as the thickness of a film base material, However, Usually, it is preferable to set it as the value within the range of 1-1000 micrometers.
This is because when the thickness of the base material is less than 1 μm, the mechanical strength and handleability may be excessively reduced or it may be difficult to form a uniform thickness. On the other hand, when the thickness of the base material exceeds 1000 μm, the handleability may be excessively lowered or may be economically disadvantageous.
Accordingly, the thickness of the film substrate is more preferably set to a value within the range of 5 to 500 μm, and further preferably set to a value within the range of 10 to 200 μm.

Moreover, it is also preferable that the film base material 101 is surface-treated.
Examples of such surface treatment include primer treatment, corona treatment, flame treatment and the like, and primer treatment is particularly preferable.
This is because the adhesion of the pressure-sensitive adhesive layer to the substrate film can be further improved by using the substrate on which such a primer layer is formed.
In addition, as a material constituting such a primer layer, cellulose ester (for example, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose nitrate, and combinations thereof), polyacryl, polyurethane, polyvinyl alcohol , Polyvinyl ester, polyvinyl acetal, polyvinyl ether, polyvinyl ketone, polyvinyl carbazole, polyvinyl butyral, and combinations thereof.
Also, the thickness of the primer layer is not particularly limited, but it is usually preferable to set the value within a range of 0.05 μm to 10 μm.

2. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer 10 in the optical film 100 of the present invention is a pressure-sensitive adhesive layer made of the specific pressure-sensitive adhesive described in the second embodiment.
Since the specific content of the pressure-sensitive adhesive has already been described in the first and second embodiments, a description thereof will be omitted.

Moreover, the thickness of the adhesive layer 10 is set to a value within the range of 1 to 100 μm.
This is because, by setting the thickness of the pressure-sensitive adhesive layer in such a range, the pressure-sensitive adhesive properties such as desired adhesive strength and storage elastic modulus can be more stably exhibited.
That is, when the thickness is less than 1 μm, it is difficult to express a desired adhesive force, and problems such as floating and peeling may easily occur. On the other hand, when the thickness exceeds 100 μm, problems such as adherend contamination and adhesive residue may easily occur.
Therefore, the thickness of the pressure-sensitive adhesive layer is more preferably set to a value within the range of 5 to 70 μm, and further preferably set to a value within the range of 10 to 50 μm.

Moreover, as a lamination | stacking method of the adhesive layer with respect to an optical film base material, as shown to Fig.1 (a)-(c), the adhesive composition layer 1 was laminated | stacked with respect to the optical film base material 101 from the beginning. It is preferable to leave it in a state and photocure it on it.
Moreover, as shown in FIG.1 (e), when the peeling film 2 is laminated | stacked with respect to both surfaces of the adhesive layer 10, the peeling film 2 with the smaller peeling force is peeled, and an adhesive layer You may laminate | stack by exposing 10 exposed surfaces with respect to the optical film base material 101. FIG.
In addition, as a method of bonding the obtained optical film to a to-be-adhered body, as shown to FIG.1 (c)-(d), first, the peeling film 2 currently laminated | stacked on the adhesive layer 10 is peeled, Next, it is preferable to bond the exposed surface of the pressure-sensitive adhesive layer 10 by bonding to the adherend 200.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Examples 1-14 and Comparative Examples 1-5]
1. Preparation Step of Adhesive Composition As shown in Table 1, predetermined (A) to (F) components were mixed at a predetermined ratio to prepare an adhesive composition.
The contents of the components (A) to (F) in Table 1 are shown below.

-(A) component (I) BA / AA = 95/5 Mw = 1.5 million Polymerize 95 parts by weight of butyl acrylate (BA) and 5 parts by weight of acrylic acid (AA) according to a conventional method to obtain a weight average molecular weight. 1.5 million (meth) acrylic acid ester copolymers were obtained.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.
Only Comparative Example 1 with Mw = 100,000 was used.

-(A) component (II) BA / HEA = 98.5 / 1.5 Mw = 1.5 million 98.5 parts by weight of butyl acrylate (BA) and 1.5 parts by weight of 2-hydroxyethyl acrylate (HEA) And (meth) acrylic acid ester polymer having a weight average molecular weight of 1,500,000 was obtained.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.

(B1) Component (III) BA / HEA = 85/15 (methacryloyl group added to 80 mol% of HEA amount) Mw = 800,000 85 parts by weight of butyl acrylate (BA) and 2-hydroxyethyl acrylate ( (HEA) 15 parts by weight were polymerized according to a conventional method to obtain a (meth) acrylic acid ester polymer.
Subsequently, 4.8 parts by weight (2-hydroxyethyl acrylate unit) of methacryloyloxyethyl isocyanate with respect to 100 parts by weight of the ethyl acetate solution (solid content concentration: 30% by weight) of the obtained (meth) acrylic acid ester polymer 80 equivalents to 100 equivalents).
Furthermore, 0.01 part by weight of dibutyltin dilaurate was added as a catalyst and subjected to an addition reaction at 25 ° C. for 24 hours to obtain a solution of a reactive (meth) acrylate polymer having a weight average molecular weight of 800,000.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.

(B1) component (IV) BA / HEA = 80/20 (methacryloyl group added to 80 mol% of HEA amount) Mw = 800,000 butyl acrylate (BA) 80 parts by weight and 2-hydroxyethyl acrylate ( (HEA) 20 parts by weight were polymerized according to a conventional method to obtain a (meth) acrylic acid ester polymer.
Next, 6.4 parts by weight of methacryloyloxyethyl isocyanate (2-hydroxyethyl acrylate unit) with respect to 100 parts by weight of the ethyl acetate solution (solid content concentration 30% by weight) of the obtained (meth) acrylic acid ester polymer 80 equivalents to 100 equivalents).
Furthermore, 0.01 part by weight of dibutyltin dilaurate was added as a catalyst and subjected to an addition reaction at 25 ° C. for 24 hours to obtain a solution of a reactive (meth) acrylate polymer having a weight average molecular weight of 800,000.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.

-(C) component (V)
1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (manufactured by Showa Denko KK, Karenz MT NR1)

-(C) component (VI)
Pentaerythritol tetrakis (3-mercaptobutyrate)
(Showa Denko Co., Ltd., Karenz MT PE1)

-(D) component (VII)
3-Glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM403)

-(D) component (VIII)
3-Acryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM5103)

-(E) component benzophenone / 1-hydroxycyclohexyl phenyl ketone = 1: 1 (weight) mixture (Ciba Specialty Chemicals Co., Ltd., Irgacure 500)

-(F) component (IX)
Trimethylolpropane modified tolylene diisocyanate (isocyanate crosslinking agent)
(Nippon Polyurethane Co., Ltd., Coronate L)

・ (F) Component (X)
Trimethylolpropane modified xylylene diisocyanate (isocyanate crosslinking agent)
(Mitsui Chemicals Polyurethanes, Takenate D110N)

The weight average molecular weight of the (meth) acrylic acid ester polymer and the reactive (meth) acrylic acid ester polymer having an ethylenic double bond in the side chain is determined by gel permeation chromatography (hereinafter abbreviated as GPC method). Measured).
That is, first, a calibration curve was prepared using polystyrene.
Then, (meth) concentration of the measurement object such as an acrylic acid ester copolymer is prepared 1 weight percent of tetrahydrofuran (THF) solution, manufactured by Tosoh Corporation, GEL PER MEATION CHROMATOGRAPH HLC-8020 (TSK GEL GMH XL, The weight average molecular weight was measured using a TSK _GEL GMH _XL and a TSK _GEL G2000 _HXL triple column) under the conditions of 40 ° C., THF solvent and 1 ml / min.
A TSK GUARD COLUMN manufactured by Tosoh Corporation was used as the guard column.

2. Next, on the release layer of a release film made of polyethylene terephthalate having a thickness of 38 μm as a release film (SP-PET3811, manufactured by Lintec Corporation), the thickness after drying is 25 μm. It was applied with a knife coater.
Next, after drying at 90 ° C. for 1 minute to form a pressure-sensitive adhesive composition layer, the surface of the obtained pressure-sensitive adhesive composition layer on the side without the release film is directly thickened as an optical film substrate. It laminated | stacked by making it closely_contact | adhere with respect to a 180-micrometer polyvinyl-alcohol-type polarizing plate (Sumitomo Chemical Co., Ltd. product), and obtained the structure which consists of a polarizing plate / adhesive composition layer / release film.

3. Light Irradiation Step Next, ultraviolet light (UV) is irradiated from the release film side of the structure under the following conditions, the pressure-sensitive adhesive composition layer is used as a pressure-sensitive adhesive layer, and a polarizing plate with a pressure-sensitive adhesive layer as an optical film is obtained. Obtained.
At this time, the thickness of the pressure-sensitive adhesive layer was 25 μm.
Lamp: manufactured by Fusion Co., Ltd., electrodeless lamp H-bulb light usage: 600 mJ / cm ²
Illuminance: 150 mW / cm ²
In addition, the light quantity and illuminance of the ultraviolet rays were measured using UVPF-36 manufactured by Eye Graphics Co., Ltd.

4). Evaluation (1) Evaluation of seasoning-less property (1) -1 Evaluation of storage elastic modulus Adhesive after 1 day and 7 days after production (more specifically, after irradiation with active energy rays, the same applies hereinafter) The storage elastic modulus G ′ at 23 ° C. of the layer was measured.
That is, the exposed surface on the pressure-sensitive adhesive composition layer side of the composition composed of the pressure-sensitive adhesive composition layer / release film substrate obtained in the above-described pressure-sensitive adhesive composition coating step is separated from the polarizing plate instead of the polarizing plate. It laminated | stacked on the film (the Lintec Co., Ltd. make, SP-PET3801).
Subsequently, light was irradiated on the conditions similar to the light irradiation process mentioned above, and the adhesive layer pinched | interposed into two peeling films was obtained.
Next, the storage elastic modulus G ′ at 23 ° C. after 1 day and 7 days after production in the obtained pressure-sensitive adhesive layer was measured according to JIS K7244-6.
That is, a plurality of 25 μm thick adhesives 1 day and 7 days after photocuring were laminated to prepare a columnar test piece having a diameter of 8 mm × 3 mm.
Subsequently, the storage elastic modulus G ′ of the test piece obtained under the following conditions was measured using a torsional shear method. The obtained results are shown in Table 2.
Measuring device: Rheometric Co., Ltd., automatic viscoelasticity measuring device DYNAMIC ANALYZER RDAII
Frequency: 1Hz
Temperature: 23 ° C

(1) -2 Evaluation of adhesive strength The adhesive strength of the adhesive layer was measured 1 day and 7 days after production.
That is, an optical film for measuring adhesive force was manufactured in the same manner as the polarizing plate with the pressure-sensitive adhesive layer described above except that a polyethylene terephthalate film (manufactured by Toray Industries, Inc., Lumirror U426) was used instead of the polarizing plate.
Next, samples 25 mm wide and 100 mm long were cut out from the optical films 1 day and 7 days after production, respectively, and the release film was peeled off and pasted on alkali-free glass (Corning Corp., 1737), and then autoclaved. (Kurihara Seisakusho Co., Ltd.) was pressurized under the conditions of 0.5 MPa, 50 ° C., and 20 minutes.
Next, after being left for 24 hours in an environment of 23 ° C. and 50% RH, using a tensile tester (Orientec Co., Ltd., Tensilon), the adhesive strength was adjusted under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °. It was measured. The obtained results are shown in Table 2.

(2) Durability Evaluation (2) -1 Evaluation of Floating, Peeling, etc. About the obtained polarizing plate with the pressure-sensitive adhesive layer, floating, peeling, etc. of the polarizing plate with the pressure-sensitive adhesive layer under durability conditions were evaluated.
That is, after adjusting the obtained polarizing plate with an adhesive layer to a size of 233 mm × 309 mm with a cutting device (manufactured by Sugano Seiki Co., Ltd., Super Cutter PN1-600), the release film was peeled off to remove alkali-free glass ( It was bonded to Corning Co., Ltd., 1737).
Subsequently, it pressurized in 0.5 MPa, 50 degreeC, and the conditions for 20 minutes in the autoclave (made by Kurihara Seisakusho). After that, it was put in an environment of 60 ° C / relative humidity 90% RH and 80 ° C / dry, and 200 hours later, it was observed using a 10 magnification loupe, and durability was evaluated according to the following criteria. did. The obtained results are shown in Table 2.
In Comparative Examples 3 to 5, evaluation was performed using the polarizing plate with the pressure-sensitive adhesive layer 7 days after production, and otherwise, evaluation was performed using the polarizing plate with the pressure-sensitive adhesive layer 1 day after production.
A: There are no defects on the four sides 0.3 mm or more from the outer peripheral edge.
◯: There are no defects on the four sides 0.6 mm or more from the outer peripheral edge.
X: One of the four sides has an abnormal appearance defect of an adhesive of 0.1 mm or more such as floating, peeling, foaming, or streaking from the outer peripheral edge to 0.6 mm or more.

(2) -2 Evaluation of light leakage About the obtained polarizing plate with an adhesive layer, the light leakage in durability conditions was evaluated.
That is, after adjusting the obtained polarizing plate with an adhesive layer to a size of 233 mm × 309 mm with a cutting device (manufactured by Sugano Seiki Co., Ltd., Super Cutter PN1-600), the release film was peeled off to remove alkali-free glass ( It was bonded to Corning Co., Ltd., 1737).
Subsequently, it pressurized in 0.5 MPa, 50 degreeC, and the conditions for 20 minutes in the autoclave (made by Kurihara Seisakusho). In addition, the above-mentioned bonding was performed so that the polarization axis of a polarizing plate might be in a crossed Nicol state on the front and back of non-alkali glass.
Next, after leaving at 80 ° C. for 200 hours in this state, it was left for 2 hours in an environment of 23 ° C. and 50% relative humidity, and light leakage was evaluated by the following method.
That is, by using MCPD-2000 manufactured by Otsuka Electronics Co., Ltd., the brightness of each region shown in FIG. It was evaluated. The results obtained are shown in Table 2.
Note that the smaller the value of ΔL *, the smaller the light leakage.
ΔL * = [(b + c + d + e) / 4] −a
(Where a, b, c, d, and e are the lightnesses at predetermined measurement points (one central portion of each region) in the A region, B region, C region, D region, and E region, respectively. )
A: The value of ΔL * is less than 2.
○: The value of ΔL * is a value of 2 to 3 or less.
X: The value of ΔL * exceeds 3.
3 and 4 show photographs of light leakage in each of Example 1 and Comparative Example 5 after being left for 2 hours in an environment of 23 ° C. and 50% relative humidity after being left at 80 ° C. for 200 hours.

(3) Evaluation of haze value The haze value of the pressure-sensitive adhesive layer was evaluated.
That is, the pressure-sensitive adhesive composition was applied on the release layer of the first release film (SP-PET3811, manufactured by Lintec Corporation) with a knife type coater so that the thickness after drying was 25 μm. .
Next, a drying treatment was performed at 90 ° C. for 1 minute to form an adhesive composition layer.
Next, a lightly peelable second release film (Lintech Co., Ltd., SP-PET3801) was bonded to the exposed surface side of the obtained pressure-sensitive adhesive composition layer rather than the first release film.
Subsequently, ultraviolet rays were irradiated under the same irradiation conditions as in the light irradiation step described above, and the pressure-sensitive adhesive composition layer was photocured to obtain a pressure-sensitive adhesive layer.
Subsequently, after peeling off the 2nd peeling film and bonding the obtained adhesive layer to soda-lime glass, the 1st peeling film was peeled off and it was set as the measurement sample.
And about the obtained measurement sample, the haze value was measured using the integrating sphere type light transmittance measuring apparatus, based on JISK7105. The obtained results are shown in Table 2.

(4) Evaluation of reworkability About the obtained polarizing plate with an adhesive layer, reworkability was evaluated.
That is, a 25 mm wide, 100 mm long sample was cut out from the polarizing plate with the pressure-sensitive adhesive layer after 1 day from the production, and then the release film was peeled off and pasted on alkali-free glass (Corning Co., Ltd., 1737). The mixture was heated in an autoclave (manufactured by Kurihara Seisakusho Co., Ltd.) under the conditions of 0.5 MPa, 50 ° C., and 20 minutes.
Next, after being left for 7 days in an environment of 23 ° C. and 50% RH, using a tensile tester (Orientec Co., Ltd., Tensilon), the adhesive strength was adjusted under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °. The reworkability was evaluated according to the following criteria. The obtained results are shown in Table 2.
○: The adhesive strength after 7 days from bonding is a value of less than 25 N / 25 mm.
X: The adhesive strength after 7 days from pasting is a value of 25 N / 25 mm or more.

[Examples 15 to 28 and Comparative Examples 6 to 7]
1. Preparation of pressure-sensitive adhesive composition As shown in Table 3, predetermined (A) to (E) components were mixed at a predetermined ratio to prepare a pressure-sensitive adhesive composition.
The contents of the components (A) to (E) in Table 1 are shown below.

-(A) component (I) BA / AA = 95/5 Mw = 1.5 million Polymerize 95 parts by weight of butyl acrylate (BA) and 5 parts by weight of acrylic acid (AA) according to a conventional method to obtain a weight average molecular weight. 1.5 million (meth) acrylic acid ester polymers were obtained.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.
Only Comparative Example 6 with Mw = 100,000 was used.

-(A) component (II) BA / HEA = 98.5 / 1.5 Mw = 1.5 million 98.5 parts by weight of butyl acrylate (BA) and 1.5 parts by weight of 2-hydroxyethyl acrylate (HEA) And (meth) acrylic acid ester polymer having a weight average molecular weight of 1,500,000 was obtained.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.

・ (B2) Component (III)
Tris (acryloxyethyl) isocyanurate (Aronix M-315, manufactured by Toagosei Co., Ltd.)

-(B2) component (IV)
Trimethylolpropane triacrylate (manufactured by Toa Gosei Co., Ltd., Aronix M-309)

-(C) component (V)
1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (manufactured by Showa Denko KK, Karenz MT NR1)

-(C) component (VI)
Pentaerythritol tetrakis (3-mercaptobutyrate)
(Showa Denko Co., Ltd., Karenz MT PE1)

(B1) component (VII) BA / HEA = 85/15 (methacryloyl group added to 80 mol% of HEA amount) Mw = 800,000 butyl acrylate (BA) 85 parts by weight and 2-hydroxyethyl acrylate ( (HEA) 15 parts by weight were polymerized according to a conventional method to obtain a (meth) acrylic acid ester polymer.
Subsequently, 4.8 parts by weight (2-hydroxyethyl acrylate unit) of methacryloyloxyethyl isocyanate with respect to 100 parts by weight of the ethyl acetate solution (solid content concentration: 30% by weight) of the obtained (meth) acrylic acid ester polymer 80 equivalents to 100 equivalents).
Furthermore, 0.01 part by weight of dibutyltin dilaurate was added as a catalyst, followed by addition reaction at 25 ° C. for 24 hours, to obtain a solution of a reactive (meth) acrylate polymer having a weight average molecular weight of 800,000.
When preparing the pressure-sensitive adhesive composition, an 18% by weight ethyl acetate solution was used.

-(E) component (VIII)
Benzophenone / 1-hydroxycyclohexyl phenyl ketone = 1: 1 (weight) mixture (manufactured by Ciba Specialty Chemicals, Inc., Irgacure 500)

-(D) component (IX)
3-Glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM403)

-(D) component (X)
3-Acryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM5103)

The weight average molecular weight of the (meth) acrylic acid ester polymer and the reactive (meth) acrylic acid ester polymer having an ethylenic double bond in the side chain is determined by gel permeation chromatography (hereinafter abbreviated as GPC method). Measured).
That is, first, a calibration curve was prepared using polystyrene. Hereinafter, the weight average molecular weight (Mw) is expressed in terms of polystyrene.
Then, (meth) concentration of the measurement object such as an acrylic acid ester copolymer is prepared 1 weight percent of tetrahydrofuran (THF) solution, manufactured by Tosoh Corporation, GEL PER MEATION CHROMATOGRAPH HLC-8020 (TSK GEL GMH XL, The weight average molecular weight was measured using a TSK _GEL GMH _XL and a TSK _GEL G2000 _HXL triple column) under the conditions of 40 ° C., THF solvent and 1 ml / min.
A TSK GUARD COLUMN manufactured by Tosoh Corporation was used as the guard column.

2. Adhesive Composition Application Step and Light Irradiation Step Subsequently, in the same manner as in Example 1, the adhesive composition application step and the light irradiation step were performed to obtain a polarizing plate with an adhesive layer as an optical film.
At this time, the thickness of the pressure-sensitive adhesive layer was 25 μm.

3. Evaluation As in Example 1, evaluation of seasoning-less property (evaluation of storage elastic modulus and evaluation of adhesive strength), evaluation of durability (evaluation of floating, peeling, etc. and evaluation of light leakage), haze value, and reworkability Was evaluated. Table 4 shows the obtained results.
In Examples 15 to 28 and Comparative Examples 6 to 7, the evaluation criteria for reworkability were evaluated as the following contents.
(Evaluation criteria for reworkability)
○: The adhesive strength after 7 days from bonding is a value of less than 35 N / 25 mm.
X: The adhesive strength after 7 days from bonding is a value of 35 N / 25 mm or more.

As detailed above, according to the present invention, (A) a (meth) acrylic acid ester polymer having a predetermined weight average molecular weight and (B1) a reactive (meth) acrylic acid ester weight having a predetermined weight average molecular weight. Combined or (B2) predetermined polyene compound, or (B1) and (B2), and (C) predetermined polythiol compound are blended at a predetermined ratio, so that it is good regardless of environmental changes without seasoning Adhesive properties can be obtained.
As a result, the seasoning period when the pressure-sensitive adhesive composition is used as a pressure-sensitive adhesive is unnecessary, and even when exposed to a harsh environment for a long period of time, it does not cause a change in performance of the pressure-sensitive adhesive itself. By suppressing expansion and contraction of the substrate to which the pressure-sensitive adhesive is applied, a pressure-sensitive adhesive composition that does not cause a functional change can be obtained.
Therefore, the pressure-sensitive adhesive composition of the present invention is expected to contribute significantly to the improvement in quality and cost of optical films such as liquid crystal display devices, plasma display devices, organic electroluminescence devices, and inorganic electroluminescence devices. The

1: adhesive composition (layer), 2: release film, 10: adhesive (layer), 100: optical film, 101: optical film substrate, 200: adherend

Claims (12)

The following (A), (B1), (C) component, or the following (A), (B2), (C) component, or the following (A), (B1), (B2), (C) component A pressure-sensitive adhesive composition containing the pressure-sensitive adhesive composition.
(A) The weight average molecular weight is 200,000-2,500,000 (meth) acrylic acid ester polymer 100 parts by weight (B1) The weight average molecular weight is 30,000-1,500,000, and has an ethylenic double bond in the side chain 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule Part   The component (A) comprises (meth) acrylic acid ester having a value in the range of 1 to 20 carbon atoms of the alkyl group as a structural unit, and a hydroxyl group, carboxyl group, amino group and amide group in the molecule. A monomer having at least one selected from the group, and a copolymerization ratio (by weight) of the monomer within a range of 99.9: 0.1 to 80:20 The pressure-sensitive adhesive composition according to claim 1.   The component (B1) is, as a structural unit, a (meth) acrylic acid ester having an alkyl group with a carbon number in the range of 1 to 20, a monomer having an ethylenic double bond in the side chain, The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the copolymerization ratio (by weight) is a value in the range of 99: 1 to 50:50.   The ethylenic double bond in the side chain of the component (B1) is a (meth) acryloyl group or a (meth) acryloyloxy group introduced via an isocyanate group. The pressure-sensitive adhesive composition according to any one of the above.   The component (B2) is a reactive isocyanurate compound having two or more (meth) acryloyl groups or (meth) acryloyloxy groups in one molecule. The pressure-sensitive adhesive composition according to one item.   The component (C) is 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate), tris (3-mercaptopropionyloxyethyl) isocyanurate, trimethylolpropane tris3-mercaptopropionate, pentaerythritol tetrakis 3-mercaptopropionate and dipentaerythritol hexa3-mercaptopropio The pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive composition is at least one selected from the group consisting of nates.   (D) The component further contains a silane coupling agent, and the content of the component (D) is a value within the range of 0.001 to 10 parts by weight with respect to 100 parts by weight of the component (A). The pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein   The component (E) further contains a photopolymerization initiator, and the content of the component (E) is set to a value of less than 10 parts by weight with respect to 100 parts by weight of the component (A). The pressure-sensitive adhesive composition according to any one of claims 1 to 7. A pressure-sensitive adhesive obtained by curing a pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive is formed through the following steps (1) to (3).
(1) The following (A), (B1), (C) component, or the following (A), (B2), (C) component, or the following (A), (B1), (B2), (C ) A step of preparing a pressure-sensitive adhesive composition containing the component (A) 100 parts by weight of a (meth) acrylic acid ester polymer having a weight average molecular weight of 200,000 to 2.5 million (B1) having a weight average molecular weight 1 to 100 parts by weight of a reactive (meth) acrylic acid ester polymer having an ethylenic double bond in the side chain, which is 30,000 to 1,500,000,
(B2) 1 to 50 parts by weight of a polyene compound having two or more ethylenic double bonds in one molecule (C) 0.01 to 50 weights of a polythiol compound having two or more mercapto groups in one molecule Part (2) The step of applying the pressure-sensitive adhesive composition to the release film (3) The step of irradiating the active energy ray at a dose in the range of 50 to 1000 mJ / cm ²   The pressure-sensitive adhesive according to claim 9, wherein the storage elastic modulus G 'at 23 ° C is set to a value within a range of 0.01 to 0.8 MPa.   An optical film comprising a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive according to claim 9 on a film substrate, wherein the thickness of the pressure-sensitive adhesive layer is set to a value in the range of 1 to 100 μm. An optical film.   The optical film according to claim 11, wherein the film substrate is a polarizing plate.