JP6873682B2 - A method for manufacturing a rubber-based pressure-sensitive adhesive composition, a rubber-based pressure-sensitive adhesive layer, an optical film with a rubber-based pressure-sensitive adhesive layer, an optical member, an image display device, and a rubber-based pressure-sensitive adhesive layer. - Google Patents

Description

The present invention relates to a rubber-based pressure-sensitive adhesive composition and a rubber-based pressure-sensitive adhesive layer formed from the rubber-based pressure-sensitive adhesive composition. The present invention also relates to an optical film with a rubber-based pressure-sensitive adhesive layer provided on the optical film with the rubber-based pressure-sensitive adhesive layer, and an optical member including the rubber-based pressure-sensitive adhesive layered optical film. The present invention also relates to an image display device including the optical film with an adhesive layer and / or an optical member. Furthermore, the present invention relates to a method for producing a rubber-based pressure-sensitive adhesive layer.

In recent years, there has been a strong demand for weight reduction and thinning in image display devices such as liquid crystal display devices, and it is possible to reduce the weight and weight of various optical members such as polarizing films used in image display devices. It is requested.

For example, as a polarizing film, a single-sided protective polarizing film having a protective film on only one side of the polarizer is known. Although such a single-sided protective polarizing film can be made thinner and lighter, there is a problem that one side of the polarizing element is not protected by the protective film, so that it is easily deteriorated by moisture or the like. Further, even in the case of the double-sided protective polarizing film, when the protective film is thinned, the polarizer may be similarly deteriorated due to moisture or the like.

Further, since the organic EL panel mounted on the organic EL (Electroluminescence) display device is extremely sensitive to moisture and oxygen in the atmosphere, an optical film having a barrier layer or a barrier function is usually formed on the surface of the organic EL panel. It is provided, and it is required that the pressure-sensitive adhesive layer for laminating them does not allow moisture or the like to permeate (low moisture permeability).

As described above, various optical members used in the image display device are liable to be deteriorated by moisture or the like depending on the material thereof, and moisture or the like is transmitted through the adhesive layer for adhering the optical member to the adherend. It was required not to let it (low moisture permeability).

Examples of the material for forming such a low moisture permeability pressure-sensitive adhesive layer include an adhesive encapsulating composition containing a hydrogenated cyclic olefin polymer and a polyisobutylene resin (see, for example, Patent Document 1) and an unsaturated bond. A highly barrier adhesive composition containing a conjugated diene-based uncrosslinked rubber, a crosslinked rubber composition containing a hydrogen-extracting photopolymerization initiator (see, for example, Patent Document 2), and a butyl-based rubber containing a specific amount of isoprene (see Patent Document 2). For example, Patent Document 3) and the like are known.

Special Table 2009-524705 Japanese Unexamined Patent Publication No. 2010-180370 Special Table 2015-522664

It is described that the adhesives and the like of Patent Documents 1 to 3 have moisture barrier characteristics, gas barrier characteristics, and the like, but when the adhesive layer described in these documents is stored in a high temperature environment, it floats or peels off. In some cases, such a problem may occur. This is because Patent Document 1 does not study cross-linking of rubber-based resins, and Patent Documents 2 and 3 describe that cross-linking rubber, but cross-links rubber having an unsaturated bond. It is a cross-linking utilizing an unsaturated bond in rubber. In such cross-linking, if the number of unsaturated bonds is small, the cross-linking density is low and the durability is not improved, and if the number of unsaturated bonds is large, the remaining unsaturated bonds are deteriorated by sunlight or the like, resulting in yellowing or main chain breakage. It occurred and sometimes became a problem in practical use.

Therefore, the present invention has a rubber-based pressure-sensitive adhesive composition capable of forming a rubber-based pressure-sensitive adhesive layer having low moisture permeability and having high durability capable of suppressing the occurrence of problems such as floating and peeling even in a high-temperature environment. The purpose is to provide things. Further, the present invention includes an optical including a rubber-based pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, an optical film with a pressure-sensitive adhesive layer provided with the rubber-based pressure-sensitive adhesive layer, and an optical film with the rubber-based pressure-sensitive adhesive layer. The purpose is to provide a member. Another object of the present invention is to provide an image display device including one or more selected from the group consisting of the rubber-based pressure-sensitive adhesive layered optical film and the optical member. Another object of the present invention is to provide a method for producing the rubber-based pressure-sensitive adhesive layer.

As a result of diligent studies to solve the above problems, the present inventors have found the following rubber-based pressure-sensitive adhesive composition and have completed the present invention.

That is, the present invention relates to a rubber-based pressure-sensitive adhesive composition, which comprises polyisobutylene and a hydrogen-extracting photopolymerization initiator.

The rubber-based pressure-sensitive adhesive composition of the present invention preferably contains 20 parts by weight or less of the polyfunctional radical-polymerizable compound with respect to 100 parts by weight of the polyisobutylene.

The polyfunctional radically polymerizable compound is preferably a compound having at least two (meth) acryloyl groups.

The compound having at least two (meth) acryloyl groups is a bifunctional (meth) acrylate having two (meth) acryloyl groups and / or a trifunctional (meth) acrylate having three (meth) acryloyl groups. Is preferable.

The hydrogen abstraction type photopolymerization initiator is preferably a benzophenone compound.

The content of the hydrogen abstraction type photopolymerization initiator is preferably 0.001 to 10 parts by weight with respect to 100 parts by weight of the polyisobutylene.

The rubber-based pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive adhesive containing a terpene skeleton, a pressure-sensitive adhesive containing a rosin skeleton, and at least one pressure-imparting agent selected from the group consisting of hydrogenated products thereof. Is preferable.

The rubber-based pressure-sensitive adhesive composition of the present invention can be crosslinked by irradiation with active energy rays.

It is preferable that the active energy ray is ultraviolet rays.

A rubber-based pressure-sensitive adhesive layer having a thickness of 50 μm formed from the rubber-based pressure-sensitive adhesive composition, at 40 ° C., 92% R.I. H. The moisture permeability in the above is preferably 50 g / (m ² · day) or less.

The present invention also relates to a rubber-based pressure-sensitive adhesive layer, which is characterized by being formed from the rubber-based pressure-sensitive adhesive composition.

The present invention also relates to an optical film and an optical film with a rubber-based pressure-sensitive adhesive layer, which comprises the rubber-based pressure-sensitive adhesive layer provided on the optical film.

The optical film is preferably a polarizing film having a protective film on at least one side of the polarizer.

It is preferable that the polarizing film is a single-sided protective polarizing film having a protective film on only one side of the polarizer, and the rubber-based pressure-sensitive adhesive layer is laminated on the side that does not have the protective film of the polarizer.

It is preferable that the optical film is a brightness improving film.

Further, in the present invention, the rubber-based pressure-sensitive adhesive layer and a 92% R.D. H. The present invention relates to an optical member comprising a film having a moisture permeability of 1 g / (m ^{2 · day) or less.}

The present invention also relates to an image display device comprising the optical film with a rubber-based pressure-sensitive adhesive layer and at least one selected from the group consisting of the optical members.

Furthermore, the present invention relates to a method for producing a rubber-based pressure-sensitive adhesive layer, which is obtained by irradiating the rubber-based pressure-sensitive adhesive composition with active energy rays and cross-linking the composition.

Since the rubber-based pressure-sensitive adhesive composition of the present invention contains polyisobutylene containing no double bond in the main chain and a hydrogen-extracting photopolymerization initiator, a crosslinked structure is introduced by irradiating with active energy rays. To provide a rubber-based adhesive layer (having high durability) capable of suppressing the occurrence of defects (floating, peeling, etc.) even in a high temperature environment while maintaining low moisture permeability. Can be done.

Further, the present invention can provide an optical film with a rubber-based adhesive layer, an optical member, and an image display device having excellent optical reliability, which are excellent in durability in a high temperature environment and excellent in low moisture permeability. Furthermore, the present invention can provide a method for producing a rubber-based pressure-sensitive adhesive layer that exhibits the above-mentioned excellent effects.

It is sectional drawing which shows typically the polarizing film with an adhesive layer which is one Embodiment of this invention. It is sectional drawing which shows typically one Embodiment of the optical member of this invention. It is sectional drawing which shows typically one Embodiment of the optical member of this invention.

1. 1. Rubber-based Adhesive Composition The rubber-based pressure-sensitive adhesive composition of the present invention is characterized by containing polyisobutylene and a hydrogen-extracting photopolymerization initiator.

(1) Polyisobutylene The polyisobutylene (PIB) is a homopolymer of isobutylene, and for example, a commercially available product such as OPPANOL manufactured by BASF can be used. In the present invention, since polyisobutylene containing no double bond in the main chain is used, it has excellent weather resistance.

The weight average molecular weight (Mw) of the polyisobutylene is preferably 100,000 or more, more preferably 300,000 or more, further preferably 600,000 or more, and particularly preferably 700,000 or more. .. The upper limit of the weight average molecular weight is not particularly limited, but is preferably 5 million or less, more preferably 3 million or less, and even more preferably 2 million or less. By setting the weight average molecular weight of the polyisobutylene to 100,000 or more, a rubber-based pressure-sensitive adhesive composition having more excellent durability during high-temperature storage can be obtained.

The content of the polyisobutylene is not particularly limited, but is preferably 50% by weight or more, more preferably 60% by weight or more, based on the total solid content of the rubber-based pressure-sensitive adhesive composition. It is more preferably 70% by weight or more, further preferably 80% by weight or more, further preferably 85% by weight or more, and particularly preferably 90% by weight or more. The upper limit of the content of polyisobutylene is not particularly limited, and is preferably 99% by weight or less, and more preferably 98% by weight or less. It is preferable that polyisobutylene is contained in the above range because it is excellent in low moisture permeability.

Further, the rubber-based pressure-sensitive adhesive composition of the present invention may contain a polymer, an elastomer or the like other than the polyisobutylene. Specifically, copolymers of isobutylene and normal butylene, copolymers of isobutylene and isoprene (for example, butyl rubbers such as regular butyl rubber, chlorinated butyl rubber, brominated butyl rubber, partially cross-linked butyl rubber), and sulfides thereof. Isobutylene-based polymers such as substances and modified products (for example, those modified with functional groups such as hydroxyl group, carboxyl group, amino group, epoxy group); styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene -Sterene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-propylene-styrene block copolymer (separates of SEPS, SIS), styrene-ethylene-propylene block Styrene-based heat such as copolymers (SEP, hydrogenated styrene-isoprene block copolymer), styrene-isobutylene-styrene block copolymers (SIBS), styrene-based block copolymers such as styrene-butadiene rubber (SBR), etc. Plastic elastomers; butyl rubber (IIR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), EPR (binary ethylene-propylene rubber), EPT (ternary ethylene-propylene rubber), acrylic rubber, urethane rubber, Polyurethane-based thermoplastic elastomers; Polyester-based thermoplastic elastomers; Blend-based thermoplastic elastomers such as polymer blends of polypropylene and EPT (ternary ethylene-propylene rubber) can be mentioned. These can be added within a range that does not impair the effects of the present invention, but are preferably about 10 parts by weight or less with respect to 100 parts by weight of the polyisobutylene, and are not included from the viewpoint of durability. preferable.

(2) Hydrogen Extraction Type Photopolymerization Initiator A hydrogen extraction type photopolymerization initiator extracts hydrogen from the polyisobutylene and reacts with polyisobutylene without cleaving the initiator itself by irradiating it with active energy rays. You can make dots. By forming the reaction point, the cross-linking reaction of polyisobutylene can be started.

As the photopolymerization initiator, in addition to the hydrogen abstraction type photopolymerization initiator used in the present invention, a cleavage type photopolymerization initiator that cleaves and decomposes the photopolymerization initiator itself to generate radicals by irradiation with active energy rays is also used. Are known. However, when a cleaved photopolymerization initiator is used for the polyisobutylene used in the present invention, the main chain of polyisobutylene is cleaved by the photopolymerization initiator in which radicals are generated, and the polyisobutylene cannot be crosslinked. In the present invention, polyisobutylene can be crosslinked as described above by using a hydrogen abstraction type photopolymerization initiator.

Examples of the hydrogen abstraction type photopolymerization initiator include acetophenone, benzophenone, methyl-4-phenylbenzophenone o-benzoylbenzoate, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4,4'-dimethoxybenzophenone, 4,4. '-Dichlorobenzophenone, 4,4'-dimethylbenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, acrylicized benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, Benzophenone compounds such as 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone compounds such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone; 4, 4'-bis (dimethylamino)
1481850634851_0
, 4,4'-Diethylaminobenzophenone and other aminobenzophenone compounds; 10-butyl-2-chloroacrydone, 2-ethylanthraquinone, 9,10-phenanthrenquinone, camphorquinone and the like; acetnaphthone, 1-hydroxycyclohexyl Aromatic ketone compounds such as phenylketone; aromatic aldehydes such as terephthalaldehyde, and quinone-based aromatic compounds such as methylanthraquinone can be mentioned. These can be used alone or in combination of two or more. Among these, benzophenone compounds are preferable, and benzophenone is more preferable, from the viewpoint of reactivity.

The content of the hydrogen abstraction type photopolymerization initiator is preferably 0.001 to 10 parts by weight, more preferably 0.005 to 10 parts by weight, based on 100 parts by weight of the polyisobutylene. It is more preferably 0.01 to 10 parts by weight. It is preferable to include the hydrogen abstraction type photopolymerization initiator in the above range because the cross-linking reaction can proceed to the desired density.

Further, in the present invention, the cleavage type photopolymerization initiator may be used together with the hydrogen abstraction type photopolymerization initiator as long as the effect of the present invention is not impaired, but it is preferable not to use it for the above-mentioned reason. ..

(3) Polyfunctional Radical Polymerizable Compound The rubber-based pressure-sensitive adhesive composition of the present invention may further contain a polyfunctional radical polymerizable compound. In the present invention, the polyfunctional radically polymerizable compound functions as a cross-linking agent for polyisobutylene.

The polyfunctional radically polymerizable compound is a compound having at least two radically polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the polyfunctional radical polymerizable compound include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol. Di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) acrylate ) Acrylate, bisphenol A propylene oxide adduct Di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, dioxane glycol Di (meth) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, EO Examples of esterified products of (meth) acrylic acid and polyhydric alcohol such as modified diglycerin tetra (meth) acrylate, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene and the like can be mentioned. it can. These can be used alone or as a mixture of two or more. Among these, an esterified product of (meth) acrylic acid and a polyhydric alcohol is preferable from the viewpoint of compatibility with polyisobutylene, and a bifunctional (meth) acrylate having two (meth) acryloyl groups and a (meth) acryloyl group. A trifunctional (meth) acrylate having three or more of the above is more preferable, and tricyclodecanedimethanol di (meth) acrylate and trimethylolpropane tri (meth) acrylate are particularly preferable.

The content of the polyfunctional radically polymerizable compound is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, and further preferably 10 parts by weight or less with respect to 100 parts by weight of the polyisobutylene. preferable. The lower limit of the content of the polyfunctional radically polymerizable compound is not particularly limited, but is preferably 0.1 part by weight or more with respect to 100 parts by weight of the polyisobutylene, for example, 0.5 parts by weight. It is more preferably parts by weight or more, and even more preferably 1 part by weight or more. When the content of the polyfunctional radical polymerizable compound is within the above range, it is preferable from the viewpoint of the durability of the obtained rubber-based pressure-sensitive adhesive layer.

The molecular weight of the polyfunctional radically polymerizable compound is not particularly limited, but is preferably, for example, about 1000 or less, and more preferably about 500 or less.

(4) Adhesive Adhesive The rubber-based adhesive composition of the present invention is at least one selected from the group consisting of a tackifier containing a terpene skeleton, a tackifier containing a rosin skeleton, and a hydrogenated product thereof. A tackifier can be included. By including a tackifier in the rubber-based pressure-sensitive adhesive composition, a rubber-based pressure-sensitive adhesive layer having high adhesiveness to various adherends and having high durability even in a high temperature environment is formed. It is preferable because it can be used.

Examples of the tackifier containing the terpene skeleton include terpene polymers such as α-pinene polymer, β-pinene polymer, and dipentene polymer, and terpene polymers modified (phenolic modification, styrene modification, aromatics). Modified terpene resins (modified, hydrogenated modified, hydrocarbon modified, etc.) can be mentioned. Examples of the modified terpene resin include terpene phenol resin, styrene modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin (hydrogenated terpene resin) and the like. Examples of the hydrogenated terpene resin referred to here include hydrogenated terpene polymers, other modified terpene resins, and hydrogenated terpene phenol resins. Among these, a hydrogenated terpene phenol resin is preferable from the viewpoint of compatibility with the rubber-based pressure-sensitive adhesive composition and adhesive properties.

Examples of the tackifier containing the rosin skeleton include rosin resin, polymerized rosin resin, hydrogenated rosin resin, rosin ester resin, hydrogenated rosin ester resin, rosin phenol resin, and the like. Unmodified rosins (raw rosins) such as tall oil rosins, hydrogenated, disproportionated, polymerized, and other chemically modified modified rosins, and derivatives thereof can be used.

As the tackifier, for example, commercially available products such as Clearon series and Polystar series manufactured by Yasuhara Chemical Co., Ltd., Superester series, Pencel series and Pine Crystal series manufactured by Arakawa Chemical Industry Co., Ltd. can be used. it can.

When the tackifier is a hydrogenated agent, the hydrogenated product may be a partially hydrogenated partially hydrogenated product, and all the double bonds in the compound are completely hydrogenated. It may be a hydrogenated product. In the present invention, a completely hydrogenated additive is preferable from the viewpoint of adhesive properties, weather resistance and hue.

It is preferable that the tackifier contains a cyclohexanol skeleton from the viewpoint of tackiness. Although the detailed principle is unknown, it is considered that the cyclohexanol skeleton has a better balance of compatibility with the base polymer polyisobutylene than the phenol skeleton. As the tackifier containing a cyclohexanol skeleton, for example, a hydrogenated product such as a terpene phenol resin or a rosin phenol resin is preferable, and a completely hydrogenated agent such as a terpene phenol resin or a rosin phenol resin is more preferable.

The softening point (softening temperature) of the tackifier is not particularly limited, but is preferably, for example, about 80 ° C. or higher, and more preferably about 100 ° C. or higher. It is preferable that the softening point of the tackifier is 80 ° C. or higher because the tackifier can maintain its adhesive properties without softening even at a high temperature. The upper limit of the softening point of the tackifier is not particularly limited, but if the softening point becomes too high, the molecular weight becomes higher, the compatibility deteriorates, and problems such as whitening may occur. , 200 ° C. or lower, and preferably 180 ° C. or lower. The softening point of the tackifier resin referred to here is defined as a value measured by the softening point test method (ring ball method) specified in any of JIS K5902 and JIS K2207.

The weight average molecular weight (Mw) of the tackifier is not particularly limited, but is preferably 50,000 or less, preferably 30,000 or less, and more preferably 10,000 or less. It is more preferably 8000 or less, and particularly preferably 5000 or less. The lower limit of the weight average molecular weight of the tackifier is not particularly limited, but is preferably 500 or more, more preferably 1000 or more, and further preferably 2000 or more. When the weight average molecular weight of the tackifier is in the above range, the compatibility with polyisobutylene is good and problems such as whitening do not occur, which is preferable.

The amount of the tackifier added is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, and further preferably 20 parts by weight or less with respect to 100 parts by weight of the polyisobutylene. .. The lower limit of the amount of the tackifier added is not particularly limited, but is preferably 0.1 part by weight or more, more preferably 1 part by weight or more, and 5 parts by weight or more. Is even more preferable. It is preferable that the amount of the tackifier used is within the above range because the adhesive properties can be improved. Further, if the amount of the pressure-sensitive adhesive used exceeds the above range and is added in a large amount, the cohesive force of the pressure-sensitive adhesive tends to decrease, which is not preferable.

Further, a tackifier other than the tackifier containing the terpene skeleton and the tackifier containing the rosin skeleton can be added to the rubber-based pressure-sensitive adhesive composition of the present invention. Examples of the tackifier include petroleum resin-based tackifiers. Examples of the petroleum-based tackifier include aromatic petroleum resins, aliphatic petroleum resins, alicyclic petroleum resins (aliphatic cyclic petroleum resins), aliphatic / aromatic petroleum resins, and aliphatic / fats. Examples thereof include an aromatic petroleum resin, a hydrogenated petroleum resin, a kumaron resin, and a kumaron inden resin.

The petroleum resin-based tackifier can be used within a range that does not impair the effects of the present invention, and for example, it can be used in an amount of about 30 parts by weight or less with respect to 100 parts by weight of the polyisobutylene.

(5) Other Additives An organic solvent can be added as a diluent to the rubber-based pressure-sensitive adhesive composition. The diluent is not particularly limited, and examples thereof include toluene, xylene, n-heptane, dimethyl ether, and the like, and these may be used alone or in combination of two or more. it can. Of these, toluene is preferred.

The amount of the diluent added is not particularly limited, but it is preferably added in the rubber-based pressure-sensitive adhesive composition in an amount of about 50 to 95% by weight, more preferably about 70 to 90% by weight. When the amount of the diluent added is within the above range, it is preferable from the viewpoint of coatability to the support or the like.

Additives other than the above can be added to the rubber-based pressure-sensitive adhesive composition of the present invention as long as the effects of the present invention are not impaired. Specific examples of the additive include a softening agent, a cross-linking agent (for example, a polyisocyanate, an epoxy compound, an alkyl etherified melamine compound, etc.), a filler, an antiaging agent, an ultraviolet absorber, and the like. The type, combination, addition amount, and the like of the additives added to the rubber-based pressure-sensitive adhesive composition can be appropriately set according to the purpose. The content (total amount) of the additive in the rubber-based pressure-sensitive adhesive composition is preferably 30% by weight or less, more preferably 20% by weight or less, and further preferably 10% by weight or less.

2. Rubber-based pressure-sensitive adhesive layer The rubber-based pressure-sensitive adhesive layer of the present invention is characterized by being formed from the rubber-based pressure-sensitive adhesive composition. The method for producing the rubber-based pressure-sensitive adhesive layer of the present invention will be described later.

The thickness of the rubber-based pressure-sensitive adhesive layer of the present invention is not particularly limited and can be appropriately set according to the intended use, but is preferably 250 μm or less, more preferably 100 μm or less. It is more preferably 50 μm or less. The lower limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, but from the viewpoint of durability, it is preferably 1 μm or more, and more preferably 5 μm or more.

Moisture permeability of rubber SL adhesive layer of the present invention is not particularly limited, is preferably 50g ^/ (m 2 · day) or ^{less, 30g / (m 2 · day} ) , more preferably less , 20 g / (m ² · day) or less is more preferable, and 15 g / (m ² · day) or less is particularly preferable. The lower limit of the moisture permeation is not particularly limited, but ideally, it is preferable that water vapor is not permeated at all (that is, 0 g / (m ² · day)). When the moisture permeability of the rubber-based pressure-sensitive adhesive layer is within the above range, it is possible to suppress the transfer of water to the optical film when the pressure-sensitive adhesive layer is applied to an optical film such as a polarizing film, and the water content of the optical film can be suppressed. It is preferable because deterioration due to the above can be suppressed. The moisture permeability was measured at 40 ° C. and 92% R.I. H. It is the water vapor transmittance (moisture permeability) under the conditions, and the measuring method thereof can be measured by the method described in Examples.

The gel fraction of the pressure-sensitive adhesive layer of the present invention is not particularly limited, but is preferably about 10 to 98%, more preferably about 25 to 98%, further preferably about 45 to 90%, and 60 to 90%. It is particularly preferably about 85%. When the gel fraction is within the above range, both durability and adhesive strength can be achieved, which is preferable. The gel fraction can be measured by the method described in Examples.

3. 3. Method for Producing Rubber Adhesive Layer The method for producing a rubber adhesive layer of the present invention is characterized by comprising a step of irradiating the rubber adhesive composition with active energy rays to crosslink the polyisobutylene. And.

Irradiation of the active energy rays is usually performed by applying the rubber-based pressure-sensitive adhesive composition to various supports and the like, and irradiating the obtained coating layer. Further, the irradiation of the active energy rays may be performed directly on the coating layer (without bonding other members or the like), and irradiation is performed after various members such as an optical film such as a separator or glass are bonded to the coating layer. You may. When irradiating after bonding to the optical film or various members, active energy rays may be irradiated through the optical film or various members, and the optical film or various members are peeled off from the peeled surface. You may irradiate with active energy rays.

Various methods are used as the method for applying the rubber-based pressure-sensitive adhesive composition. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples include a method such as an extrusion coating method.

In the production method of the present invention, the coating layer of the rubber-based pressure-sensitive adhesive composition is irradiated with active energy rays. However, when the rubber-based pressure-sensitive adhesive composition contains an organic solvent as a diluent, After coating and before irradiation with active energy rays, it is preferable to remove the solvent and the like by heating and drying.

The heating and drying temperature is not particularly limited, but is preferably about 30 ° C. to 90 ° C., more preferably about 60 ° C. to 80 ° C. from the viewpoint of reducing the residual solvent. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably about 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 1 minute to 8 minutes.

Examples of the active energy ray include visible light, ultraviolet light, electron beam, and the like, and among these, ultraviolet light is preferable.

The irradiation conditions of ultraviolet rays are not particularly limited and can be set to arbitrary appropriate conditions according to the composition of the rubber-based pressure-sensitive adhesive composition to be crosslinked. For example, the integrated irradiation light amount is 100 mJ / cm ^2. ~ 2000 mJ / cm ² is preferable.

As the support, for example, a peeled sheet (separator) can be used.

Examples of the constituent material of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film, porous materials such as paper, cloth, and non-woven fabric, nets, foam sheets, metal foils, and laminates thereof. An appropriate thin leaf body or the like can be mentioned, but a plastic film is preferably used from the viewpoint of excellent surface smoothness.

Examples of the plastic film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene. -Vinyl acetate copolymer film and the like can be mentioned.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. If necessary, the separator may be subjected to a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, a mold release agent such as silica powder, an antifouling treatment, a coating type, a kneading type, and a vapor deposition. It is also possible to perform antistatic treatment on the mold and the like. In particular, the peelability from the pressure-sensitive adhesive layer can be further enhanced by appropriately performing a peeling treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the separator.

The thickness and moisture permeability of the rubber-based pressure-sensitive adhesive layer obtained by the production method of the present invention are as described above.

4. Optical film with pressure-sensitive adhesive layer The optical film with a rubber-based pressure-sensitive adhesive layer of the present invention is characterized by having an optical film and the rubber-based pressure-sensitive adhesive layer provided on the optical film.

As a method of forming the rubber-based pressure-sensitive adhesive layer on the optical film, the rubber-based pressure-sensitive adhesive composition is applied onto the optical film and irradiated with active energy rays to form the rubber-based pressure-sensitive adhesive layer on the optical film. Can be formed on top. Further, as described above, a rubber-based pressure-sensitive adhesive layer may be formed on a support or the like, and the rubber-based pressure-sensitive adhesive layer may be transferred onto an optical film to form an optical film with a rubber-based pressure-sensitive adhesive layer. In this case, the peeled sheet used in producing the optical film with the rubber-based pressure-sensitive adhesive layer can be used as it is as a separator for the optical film with the rubber-based pressure-sensitive adhesive layer, and the process can be simplified.

As the optical film, a film used for forming various image display devices such as a liquid crystal display device is used, and the type thereof is not particularly limited. For example, an optical film includes a polarizing film. As the polarizing film, a polarizing film having a protective film on one side or both sides of the polarizer is generally used, but in the present invention, a single-sided protective polarizing film is preferable from the viewpoint of thinning.

The polarizer is not particularly limited, and various polarizers can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene-vinyl acetate copolymerization system partially saponified film, and a bicolor property of iodine or a bicolor dye. Examples thereof include a uniaxially stretched film obtained by adsorbing a substance, a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrogenated product of polyvinyl chloride. Among these, a polarizer made of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it 3 to 7 times its original length. If necessary, it can be immersed in an aqueous solution of potassium iodide or the like, which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. In addition to being able to clean the surface of the polyvinyl alcohol film and blocking inhibitors by washing the polyvinyl alcohol film with water, it also has the effect of preventing non-uniformity such as uneven dyeing by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and then dyeing with iodine. It can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

Further, from the viewpoint of thinning, it is preferable to use a thin polarizing element having a thickness of 10 μm or less. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. It is preferable that such a thin polarizing element has less uneven thickness, excellent visibility, excellent durability because there is little dimensional change, and the thickness of the polarizing film can be reduced.

Typical examples of the thin polarizing element include JP-A-51-069644 and JP-A-2000-338329, International Publication No. 2010/100917 Pamphlet, and JP-A-2014-59328 and JP-A-2014-59328. Examples thereof include the thin polarizing film described in Japanese Patent Application Laid-Open No. 2012-73563. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as PVA-based resin) layer and a resin base material for stretching in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without any trouble such as breakage due to stretching because it is supported by the stretching resin base material.

The thin polarizing film can be stretched at a high magnification and the polarization performance can be improved even in a manufacturing method including a step of stretching in a laminated state and a step of dyeing. Alternatively, those obtained by a production method including a step of stretching in an aqueous boric acid solution as described in JP-A-2014-509328 and JP-A-2012-073563 are preferable, and in particular, JP-A-2014-059328 and JP-A-2014-059328. It is preferably obtained by a production method including a step of auxiliary stretching in the air before stretching in an aqueous boric acid solution described in JP2012-073563.

As the material for forming the protective film provided on one side or both sides of the polarizer, those having excellent transparency, mechanical strength, thermal stability, moisture blocking property, isotropic property and the like are preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples thereof include based polymers and polystyrene polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, polyolefin-based polymers such as ethylene / propylene copolymers, vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamide, imide-based polymers, and sulfone-based polymers. , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer, epoxy polymer, or Blends of the polymers and the like are also mentioned as examples of polymers forming the protective film. The protective film can also be formed as a cured layer of a thermosetting type or ultraviolet curable type resin such as acrylic type, urethane type, acrylic urethane type, epoxy type and silicone type. When protective films are provided on both sides of the polarizer, protective films made of the same polymer material may be used on the front and back sides thereof, or protective films made of different polymer materials may be used.

The thickness of the protective film can be appropriately determined, but is generally about 1 to 500 μm in terms of workability such as strength and handleability, and thin film property.

The polarizer and the protective film are usually in close contact with each other via an aqueous adhesive or the like. Examples of the water-based adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, water-based polyurethanes, and water-based polyesters. In addition to the above, examples of the adhesive between the polarizer and the protective film include an ultraviolet curable adhesive, an electron beam curable adhesive, and the like. The electron beam curable polarizing film adhesive exhibits suitable adhesiveness to the above-mentioned various protective films. Further, the adhesive used in the present invention may contain a metal compound filler.

The surface of the protective film to which the polarizer is not adhered may be subjected to a hard coat layer, antireflection treatment, anti-sticking treatment, or treatment for the purpose of diffusion or anti-glare.

For example, as shown in FIG. 1, when the polarizing film 2 is a single-sided protective polarizing film having the protective film 5 on only one side of the polarizer 4, the pressure-sensitive adhesive layer 3 has the protective film 5 of the polarizer 4. It is preferable that the film is formed on the non-side (that is, the side of the polarizer 4). In this case, the polarizer 4 and the pressure-sensitive adhesive layer 3 do not necessarily have to be in contact with each other, but from the viewpoint that the effects of the present invention can be remarkably exhibited, they are preferably in contact with each other. With such a configuration, it is possible to suppress the transfer of moisture and the like to the polarizing element, and it is possible to suppress the deterioration of the polarizer of the single-sided protective polarizing film.

Examples of optical films other than the polarizing plate film include a reflecting plate, an antitransmissive plate, a retardation plate (including a wave plate such as 1/2 and 1/4), a viewing angle compensation film, a brightness improving film, and the like. Examples thereof include an optical layer that may be used for forming a liquid crystal display device or the like. Among these, the brightness improving film can be preferably used as the optical film. These can be used alone as an optical film, or can be laminated on the polarizing film for practical use and used as one layer or two or more layers.

Further, the adhesive layer can be formed after forming an anchor layer or a transparent resin layer on the surface of the optical film or the polarizer, or performing various easy-adhesion treatments such as corona treatment and plasma treatment. Further, the surface of the pressure-sensitive adhesive layer may be subjected to an easy-adhesion treatment.

5. Optical member The optical member of the present invention includes the optical film with an adhesive layer, an optical member containing a brightness improving film (hereinafter referred to as "first optical member"), the adhesive layer, and 40 ° C., 92% R. .. H. An optical member containing a film having a moisture permeability of 1 g / (m ² · day) or less (hereinafter, referred to as “second optical member”) can be mentioned.

The first optical member is formed by further laminating a brightness improving film via an adhesive layer of the optical film with an adhesive layer. The optical film with an adhesive layer in the first optical member is preferably a polarizing film with an adhesive layer. For example, as shown in FIG. 2, an optical member 10 having a polarizing film 2, an adhesive layer 3, and a brightness improving film 6 can be mentioned. Further, such an optical member 10 may have another layer. For example, as shown in FIG. 3, the pressure-sensitive adhesive layer is on the side of the brightness improving film 6 that does not have the pressure-sensitive adhesive layer 3. The prism sheets 7 can be further laminated via (not shown) or the like. The prism sheet 7 typically has a substrate and a prism portion. Further, in FIGS. 2 and 3, a single-sided protective polarizing film is shown as in FIG. 1, but a double-sided protective polarizing film may be used. Such an optical member is preferably used as a polarizing plate on the backlight side of the liquid crystal display device.

Further, as the brightness improving film 6, a reflective polarizing plate can be mentioned. The reflective polarizing plate is a linearly polarized light separation type polarizing plate. Typical examples are a grid-type polarizing plate, a multilayer thin film laminated polarizing plate made of two or more materials having different refractive indexes, a vapor-deposited multilayer thin film having different refractive indexes, and a birefringent layer multilayer thin film made of two or more kinds of materials having different refractive indexes. Laminates, stretched two or more resin laminates using two or more resins with different refractive indexes, and polarizing plates that separate linearly polarized light by reflecting / transmitting it in the orthogonal axial direction (linearly polarized light separation). Type reflective polarizing plate). Among these, a linearly polarized light separation type reflective polarizing plate is preferably used. As such a reflective polarizing plate, for example, those commercially available under the trade name "D-BEF" manufactured by 3M Ltd. or the trade name "Nipox APCF" manufactured by Nitto Denko KK can be used.

Further, 40 ° C., 92% R.I. H. Examples of the film having a moisture permeability of 1 g / m ² · day or less include a barrier layer used for an organic EL element and the like. Examples of the barrier layer used for the organic EL element include polymers such as polyethylene trifluoride, polyethylene trifluoride chloride (PCTFE), polyimide, polycarbonate, polyethylene terephthalate, alicyclic polyolefin, and ethylene-vinyl alcohol copolymer. Examples thereof include a layer, a laminate thereof, and a polymer layer coated with an inorganic thin film such as silicon oxide, silicon nitride, aluminum oxide, and diamond-like carbon by using a film forming method such as sputtering. An optical member having such a low moisture permeability film can be suitably used for an organic EL device, and specifically, can be used as a sealing member for an organic EL element.

6. Image Display Device The image display device of the present invention is characterized by including one or more selected from the group consisting of the polarizing film with an adhesive layer and the optical member. Examples of the image display device include a liquid crystal display device, an organic EL display device, and the like.

The image display device of the present invention may include an optical film or an optical member with an adhesive layer of the present invention, and other configurations may be the same as those of the conventional image display device.

Since the image display device of the present invention includes the optical film or optical member with an adhesive layer, it has high optical reliability.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In addition, each part and% in each example is based on weight.

Production Example 1 (Production of polarizing film (1))
In order to prepare a thin polarizing film, first, a laminate in which a 9 μm-thick polyvinyl alcohol (PVA) layer is formed on an amorphous polyethylene terephthalate (PET) substrate is stretched by aerial auxiliary stretching at a stretching temperature of 130 ° C. Was generated. Next, the stretched laminate was dyed to produce a colored laminate, and the colored laminate was further stretched with boric acid water at a stretching temperature of 65 ° C. to obtain a total stretching ratio of 5.94 times with an amorphous PET substrate. An optical film laminate containing a 4 μm-thick PVA layer stretched integrally was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such two-step stretching are highly oriented, and the iodine adsorbed by staining is highly oriented in one direction as a polyiodine ion complex. An optical film laminate containing a PVA layer having a thickness of 5 μm, which constitutes a high-performance polarizing film (polarizer), was produced.

Protecting the surface of the polarizing film (polarizer, thickness: 5 μm) of the optical film laminate related to the polarizer while applying a polyvinyl alcohol-based adhesive so that the thickness of the adhesive layer is 0.1 μm. A film (a (meth) acrylic resin film having a lactone ring structure having a thickness of 20 μm and subjected to corona treatment) was attached, and then dried at 50 ° C. for 5 minutes. Next, the amorphous PET substrate was peeled off to prepare a single-protective polarizing film (polarizing film (1)) using a thin polarizing element.

Production Example 2 (Production of polarizing film (2))
A polyvinyl alcohol film having a thickness of 30 μm was dyed between rolls having different speed ratios in an iodine solution at 30 ° C. and a concentration of 0.3% for 1 minute, and stretched up to 3 times. Then, the total stretching ratio was stretched to 6 times while being immersed in an aqueous solution containing boric acid having a concentration of 4% and potassium iodide having a concentration of 10% at 60 ° C. for 0.5 minutes. Then, it was washed by immersing it in an aqueous solution containing potassium iodide having a concentration of 1.5% at 30 ° C. for 10 seconds, and then dried at 50 ° C. for 4 minutes to obtain a polarizer having a thickness of 12 μm. A 25 μm-thick triacetyl cellulose film that has been hard-coded on one side is applied to one side of the polarizer, and a 13 μm cycloolefin-based resin film is applied to the opposite surface of the polarizer. Both protective polarizing films (polarizing film (2)) were prepared by laminating with a polyvinyl alcohol-based adhesive (thickness of adhesive layer: 0.1 μm). The composition of the polarizing film (2) was a hard coat / triacetyl cellulose film / adhesive layer / polarizer / adhesive layer / cycloolefin resin film.

Production Example 3 (Production of polarizing film (3))
In a separable flask equipped with a thermometer, agitator, a reflux cooling tube and a nitrogen gas introduction tube, 99 parts by weight of butyl acrylate (BA) and 1 part by weight of 4-hydroxybutyl acrylate (4HBA) as a monomer component, as a polymerization initiator. , 0.2 part by weight of azobisisobutyronitrile and ethyl acetate as a polymerization solvent were added so that the solid content was 20%, and then nitrogen gas was flowed and nitrogen substitution was carried out for about 1 hour with stirring. Then, the flask was heated to 60 ° C. and reacted for 7 hours to obtain an acrylic polymer having a weight average molecular weight (Mw) of 1.1 million. To the acrylic polymer solution (solid content 100 parts by weight), 0.8 parts by weight of trimethylolpropane tolylene diisocyanate (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) as an isocyanate-based cross-linking agent, a silane coupling agent (Product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.1 part by weight was added to prepare an acrylic pressure-sensitive adhesive composition (A).

The obtained pressure-sensitive adhesive composition (solution) is applied to the peel-treated surface of a polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm in which one side is peeled with silicone to form a coating layer. Formed. Next, the coating layer was dried at 155 ° C. for 3 minutes to form an acrylic pressure-sensitive adhesive layer (A) having a thickness of 20 μm, and a pressure-sensitive adhesive sheet composed of a polyester film / acrylic pressure-sensitive adhesive layer (A) was prepared.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is attached to the protective film of the polarizing film (1) obtained in Production Example 1 (a (meth) acrylic resin film having a lactone ring structure with a thickness of 20 μm and subjected to corona treatment). Together, a polarizing film (3) having the composition of a polyester film (separator) / acrylic pressure-sensitive adhesive layer (A) / protective film / adhesive layer / polarizer was obtained.

Example 1
(Preparation of rubber-based composition)
100 parts by weight of polyisobutylene (trade name: OPPANOL B80, Mw: about 750,000, manufactured by BASF) and tricyclodecanedimethanol diacrylate (trade name: NK ester A-DCP, 2) as a polyfunctional radically polymerizable compound. A toluene solution containing 5 parts by weight of functional acrylate, molecular weight: 304, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., and 0.5 part of benzophenone (manufactured by Wako Pure Chemical Industries, Ltd.), which is a hydrogen abstraction type photopolymerization initiator. The pressure-sensitive adhesive solution) was adjusted so that the solid content was 15% by weight, and a rubber-based pressure-sensitive adhesive composition (solution) was prepared.

(Formation of rubber adhesive sheet)
The obtained rubber-based pressure-sensitive adhesive composition (solution) is applied to the peel-treated surface of a polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm in which one side is peel-treated with silicone. A layer was formed. Next, the coating layer was dried at 80 ° C. for 3 minutes to form a rubber-based pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet having a thickness of 50 μm was prepared. Further, on the adhesive surface of the adhesive sheet, a polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm obtained by peeling one side of the adhesive sheet with silicone is applied to the peeled surface and the rubber-based adhesive. The layers were bonded so that they touched each other. The polyester film coated on both sides of the rubber-based pressure-sensitive adhesive layer functions as a release liner (separator).

One of the separators was peeled off, and the side from which the separator was peeled off was irradiated with ultraviolet rays at room temperature to obtain a rubber-based pressure-sensitive adhesive sheet composed of a rubber-based pressure-sensitive adhesive layer / separator. The ultraviolet irradiation had a light intensity of 1000 mJ / cm ² in the UVA region.

Examples 2 to 22, Comparative Examples 1 to 5, 5
A rubber-based pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the composition and film thickness were set to those shown in Table 1.

Comparative Example 4
(Making acrylic adhesive sheet)
The acrylic pressure-sensitive adhesive composition (A) produced in Production Example 3 is applied to the peel-treated surface of a polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm in which one side is peel-treated with silicone. To form a coating layer. Next, the coating layer was dried at 120 ° C. for 3 minutes to form an adhesive layer, and a pressure-sensitive adhesive sheet having a thickness of 50 μm was prepared. Further, on the adhesive surface of the adhesive sheet, a polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm obtained by peeling one side with silicone is in contact with the peeled surface and the adhesive layer. To obtain an acrylic adhesive sheet. The polyester film coated on both sides of the pressure-sensitive adhesive layer functions as a release liner (separator).

The pressure-sensitive adhesive compositions and pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were evaluated as follows. The evaluation results are shown in Table 1.

<Durability 1 (Polarizing film (1))>
The polarizing film (1) obtained in Production Example 1 and the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples are laminated so that the polarizer of the polarizing film (1) and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet are in contact with each other. A polarizing film with an adhesive layer was obtained. The release liner of the pressure-sensitive adhesive layer was left as a separator. The composition of the obtained polarizing film with an adhesive layer was a protective film / adhesive layer / polarizer / adhesive layer / separator.

The separator of the obtained polarizing film with an adhesive layer is peeled off, the test piece is attached to a glass plate, and the state after being put into an environment of 95 ° C. for 500 hours is observed visually or using a loupe (20 times). did. Evaluation was made according to the following evaluation criteria.
⊚: No defects (foaming, peeling, etc.) occurred even when checked with a loupe.
〇: No defects could be visually confirmed, but when confirmed with a loupe, there were some defects to the extent that there was no problem in use.
X: A defect was visually confirmed.

<Durability 2 (Polarizing film (2))>
The polarizing film (2) obtained in Production Example 2 and the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples are brought into contact with the cycloolefin resin film of the polarizing film (2) and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, respectively. A polarizing film with an adhesive layer was obtained by laminating in this manner. The release liner of the pressure-sensitive adhesive layer was left as a separator. The composition of the obtained polarizing film with an adhesive layer was a hard coat / a triacetyl cellulose film / an adhesive layer / a polarizer / an adhesive layer / a cycloolefin resin film / an adhesive layer / a separator.

The separator of the obtained polarizing film with an adhesive layer is peeled off, the test piece is attached to a glass plate, and the state after being put into an environment of 95 ° C. for 500 hours is observed visually or using a loupe (20 times). did. <Durability 1> Evaluation was made according to the same evaluation criteria as in the test.

<Durability 3 (Polarizing film (3))>
A 20 μm linearly polarized light separation film (trade name: D-BEF, manufactured by 3M) was bonded to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples to prepare a brightness-improving film with a pressure-sensitive adhesive layer.

The brightening film with an adhesive layer and the polarizing film (3) obtained in Production Example 3 are obtained from the pressure-sensitive adhesive layer of the brightness improving film with an adhesive layer and the polarizing film (3) obtained in Production Example 3. A polarizing film with an adhesive layer was obtained by laminating so that the polarizers were in contact with each other. The release liner of the pressure-sensitive adhesive layer was left as a separator. The composition of the obtained polarizing film with an adhesive layer is as follows: polyester film (separator) / acrylic pressure-sensitive adhesive layer (A) / protective film / adhesive layer / polarizer / examples, and the pressure-sensitive adhesive layer obtained in Comparative Examples. / It was a brightness-improving film.

The separator of the obtained polarizing film with an adhesive layer is peeled off, the test piece is attached to a glass plate, and the state after being put into an environment of 95 ° C. for 500 hours is observed visually or using a loupe (20 times). did. <Durability 1> Evaluation was made according to the same evaluation criteria as in the test.

In the <Durability 1> and <Durability 2> tests, the polarizing film was laminated on the adherend (glass plate) of the durability test via the adhesive layers obtained in Examples and Comparative Examples, respectively. However, in the <Durability 3> test, the adherend (glass plate) of the durability test and the polarizing film were laminated via the acrylic adhesive layer (A) obtained in Production Example 3. ..

<Gel fraction>
And kite string, tetrafluoroethylene resin porous membrane with a pore size of 0.2 [mu] m: previously measures the total weight of the (trade name NITOFLON NTF1122, Nitto Denko Co., Ltd.) _(W a (mg)). From the obtained pressure-sensitive adhesive sheet, a pressure-sensitive adhesive layer was approximately 1g harvested, wrapped in purse-like to the porous membrane, after tied mouth with a kite string, to determine the weight of the parcel _(W b (mg)). The packet was placed in a 50 mL screw bottle and the screw bottle was filled with toluene. After standing at room temperature for 7 days, the then dried for 2 hours at 130 ° C. Remove the wrap, measured該包Mino weight _(W c (mg)), were determined gel fraction by the following equation.
Gel fraction (%) = (W _c- W _a ) / (W _b- W _a ) x 100

<Humidity permeability>
Using the pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples, a pressure-sensitive adhesive sheet having a thickness of the pressure-sensitive adhesive layer of 50 μm was formed according to the method described in Examples. One of the release liners of the pressure-sensitive adhesive sheet was peeled off to expose the pressure-sensitive adhesive surface, and the pressure-sensitive adhesive sheet was attached to a triacetyl cellulose film (TAC film, thickness: 25 μm, manufactured by Konica Minolta Co., Ltd.) by the pressure-sensitive adhesive surface. Then, the other release liner was peeled off to obtain a measurement sample.
Next, using this measurement sample, the moisture permeability (water vapor permeability) was measured by the moisture permeability test method (cup method, according to JIS Z 0208) under the following conditions.
Measurement temperature: 40 ° C
Relative humidity: 92%
Measurement time: 24 hours A constant temperature and humidity chamber was used for the measurement.

The notation in Table 1 is as follows.
<Polyisobutylene>
OPPANOL B80: Polyisobutylene (Mw: Approximately 750,000, manufactured by BASF)
OPPANOL B100: Polyisobutylene (Mw: Approximately 1.68 million, manufactured by BASF)
<Other polymers>
Acrylic resin: Acrylic pressure-sensitive adhesive composition obtained in Comparative Example 4 <Adhesive-imparting agent>
Completely hydrogenated terpene phenol (A): Completely hydrogenated terpene phenol with a softening point of 135 ° C. and a hydroxyl value of 160 Completely hydrogenated terpene phenol (B): Completely hydrogenated with a softening point of 160 ° C. and a hydroxyl value of 60 Terpene phenol <polyfunctional radically polymerizable compound>
A-DCP: Tricyclodecanedimethanol diacrylate (trade name: NK ester A-DCP, bifunctional acrylate, molecular weight: 304, manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
DCP: Tricyclodecanedimethanol dimethacrylate (trade name: NK ester DCP, bifunctional methacrylate, molecular weight: 332, manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
A-TMPTA: Trimethylolpropane triacrylate (trade name: NK ester A-TMPT, trifunctional acrylate, molecular weight: 296, manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
<Photopolymerization initiator>
Benzophenone: Hydrogen abstraction type photoinitiator Irgacure 184: Cleavage type photoinitiator, 1-hydroxycyclohexylphenyl ketone (manufactured by BASF)

1 Polarizing film with adhesive layer 2 Polarizing film 3 Adhesive layer 4 Polarizer 5 Protective film 6 Brightness improving film 7 Prism sheet 10 Optical member

Claims (17)

Polyisobutylene, hydrogen drawing type photopolymerization initiator, and a rubber-based pressure-sensitive adhesive composition containing a polyfunctional radically polymerizable compound,
A rubber-based pressure-sensitive adhesive layer having a thickness of 50 μm formed from the rubber-based pressure-sensitive adhesive composition, at 40 ° C., 92% R.I. H. A rubber-based pressure-sensitive adhesive composition having a moisture permeability of 20 g / (m ² · day) or less. The rubber-based pressure-sensitive adhesive composition according to claim 1, wherein the polyfunctional radical-polymerizable compound is contained in an amount of 20 parts by weight or less based on 100 parts by weight of the polyisobutylene. The rubber-based pressure-sensitive adhesive composition according to claim 2, wherein the polyfunctional radical-polymerizable compound is a compound having at least two (meth) acryloyl groups. The compound having at least two (meth) acryloyl groups is a bifunctional (meth) acrylate having two (meth) acryloyl groups and / or a trifunctional (meth) acrylate having three (meth) acryloyl groups. The rubber-based pressure-sensitive adhesive composition according to claim 3. The rubber-based pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the hydrogen-extracting photopolymerization initiator is a benzophenone-based compound. The rubber system according to any one of claims 1 to 5, wherein the content of the hydrogen abstraction type photopolymerization initiator is 0.001 to 10 parts by weight with respect to 100 parts by weight of the polyisobutylene. Adhesive composition. Any of claims 1 to 6, which comprises at least one tackifier selected from the group consisting of a tackifier containing a terpene skeleton, a tackifier containing a rosin skeleton, and a hydrogenated product thereof. The rubber-based pressure-sensitive adhesive composition described in Crab. The rubber-based pressure-sensitive adhesive composition according to any one of claims 1 to 7, wherein the rubber-based pressure-sensitive adhesive composition is crosslinked by irradiation with active energy rays. The rubber-based pressure-sensitive adhesive composition according to claim 8, wherein the active energy ray is ultraviolet rays. A rubber-based pressure-sensitive adhesive layer formed from the rubber-based pressure-sensitive adhesive composition according to any one of claims 1 to 9. An optical film with a rubber-based pressure-sensitive adhesive layer, which comprises the optical film and the rubber-based pressure-sensitive adhesive layer according to claim 10 provided on the optical film. The optical film with an adhesive layer according to claim 11 , wherein the optical film is a polarizing film having a protective film on at least one side of the polarizer. The polarizing film is a single-sided protective polarizing film having a protective film on only one side of the polarizer, and the rubber-based pressure-sensitive adhesive layer is laminated on the side that does not have the protective film of the polarizer. The optical film with a rubber-based pressure-sensitive adhesive layer according to claim 12. The optical film with a rubber-based pressure-sensitive adhesive layer according to claim 11 , wherein the optical film is a brightness-improving film. The rubber-based pressure-sensitive adhesive layer according to claim 10, and at 40 ° C., 92% R.I. H. An optical member comprising a film having a moisture permeability of 1 g / (m ^{2 · day) or less.} An image display device comprising the optical film with a rubber-based pressure-sensitive adhesive layer according to any one of claims 11 to 14 and at least one selected from the group consisting of the optical member according to claim 16. A method for producing a rubber-based pressure-sensitive adhesive layer, which comprises a step of irradiating the rubber-based pressure-sensitive adhesive composition according to any one of claims 1 to 9 with active energy rays to crosslink the polyisobutylene.

Images