JP6792382B2 - Rubber-based pressure-sensitive adhesive composition, rubber-based pressure-sensitive adhesive layer, pressure-sensitive film, optical film with rubber-based pressure-sensitive adhesive layer, optical member, and image display device - 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 and the rubber-based pressure-sensitive adhesive layer provided on the low-moisture-permeable film. The present invention also relates to an adhesive film containing the rubber-based adhesive layer. Furthermore, the present invention relates to an image display device including the optical film with an adhesive layer and / or an optical member.

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 polarizer 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 by 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 likely 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).

A rubber-based pressure-sensitive adhesive is known as a material for forming such a low-moisture-permeable pressure-sensitive adhesive layer. For example, an adhesive containing a hydrogenated cyclic olefin-based polymer and a polyisobutylene resin having a weight average molecular weight of 500,000 or more. A sex-encapsulating composition (see, for example, Patent Document 1), a polyisobutylene resin having a weight average molecular weight of 270,000 to 480,000, a polyisobutylene resin having a weight average molecular weight of 100,000 to 250,000, and hydrogen having a softening point of 90 to 135 ° C. Adhesive compositions containing chemical petroleum resins are known (see, for example, Patent Document 2).

Special Table 2009-524705 Japanese Patent No. 5416316

Although it is possible to reduce the moisture permeability of the pressure-sensitive adhesive layer by using a rubber-based pressure-sensitive adhesive, when peeling or foaming in a high-temperature environment is worse than that of acrylic pressure-sensitive adhesives used in conventional optical applications. was there. Such defects such as peeling and foaming are caused by insufficient cohesive force in the vicinity of the adhesive interface of the rubber-based pressure-sensitive adhesive layer. This lack of cohesive force near the adhesive interface is caused by the presence of many rubber-based polymers contained in the rubber-based pressure-sensitive adhesive with a small molecular weight and less entanglement near the interface of the pressure-sensitive adhesive layer, resulting in a layer with low cohesive force (fragile layer). It turned out that it was caused by.

In Patent Documents 1 and 2, although various problems are tried to be improved by adding an additive such as a tackifier to the rubber polymer, the rubber polymer itself, which is the cause in the first place, is not improved. Yes, it was not sufficient from the viewpoint of durability.

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. The present invention also provides a rubber-based pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, a pressure-sensitive adhesive film provided with the rubber-based pressure-sensitive adhesive layer, an optical film with a rubber-based pressure-sensitive adhesive layer, and an optical member. The purpose. Another object of the present invention is to provide an image display device including the optical film with a rubber-based pressure-sensitive adhesive layer and / or an optical member.

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 is a rubber-based pressure-sensitive adhesive composition containing a rubber-based base polymer.
The rubber-based base polymer contains an isobutylene-based polymer having a polydispersity (weight average molecular weight / number average molecular weight) of 4 or less.
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 present invention relates to a rubber-based pressure-sensitive adhesive composition, wherein the moisture permeability in the above is 50 g / (m ² · day) or less.

The rubber-based pressure-sensitive adhesive composition preferably contains a pressure-sensitive adhesive.

It is preferable that the tackifier is 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 softening point of the tackifier is preferably 90 ° C. or higher.

It is preferable that the rubber-based pressure-sensitive adhesive composition contains a hydrogen-extracting photopolymerization initiator.

The present invention 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 relates to a support made of a plastic base material and an adhesive film having the rubber-based pressure-sensitive adhesive layer on at least one surface of the support.

The present invention 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 on at least one surface of the optical film.

It is preferable that the optical film is 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, the polarizer, and the protective film are laminated in this order. Further, it is preferable that the optical film with a rubber-based pressure-sensitive adhesive layer further contains a retardation film, and the rubber-based pressure-sensitive adhesive layer, a retardation film, a polarizer, and a protective film are laminated in this order.

Further, the present invention has a temperature of 40 ° C. and 92% R. H. The present invention relates to a film having a moisture permeability of 1 g / (m ² · day) or less, and an optical member having the rubber-based pressure-sensitive adhesive layer on at least one surface of the film.

Furthermore, the present invention relates to an optical film with a rubber-based pressure-sensitive adhesive layer, or an image display device including at least one optical member.

The rubber-based pressure-sensitive adhesive composition of the present invention is defective even in a high-temperature environment while maintaining low moisture permeability by using a rubber-based polymer having a low molecular weight, that is, a polymer having a low polydispersity (Mw / Mn). It is possible to provide a rubber-based pressure-sensitive adhesive layer (having high durability) capable of suppressing the occurrence of floating, peeling, etc.).

Further, the present invention can provide an optical film with a rubber-based adhesive layer, an optical member, an adhesive film, 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. ..

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 the polarizing film with an adhesive layer which is one Embodiment of this invention.

1. 1. Rubber-based Adhesive Composition The rubber-based pressure-sensitive adhesive composition of the present invention contains a rubber-based base polymer.
The rubber-based base polymer contains an isobutylene-based polymer having a polydispersity (weight average molecular weight / number average molecular weight) of 4 or less.
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 50 g / (m ² · day) or less.

(1) Rubber-based polymer The rubber-based base polymer used in the present invention is a polymer that exhibits rubber elasticity in a temperature range near room temperature, and is an isobutylene-based polymer having a polydispersity (weight average molecular weight / number average molecular weight) of 4 or less. including.

Examples of the isobutylene-based polymer include those containing isobutylene as a constituent monomer. The isobutylene-based polymer may be a homopolymer of isobutylene (polyisobutylene, PIB), or a copolymer containing isobutylene as a main monomer (that is, a copolymer in which isobutylene is copolymerized in a proportion of more than 50 mol%). You may. Examples of such copolymers include 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, and partially crosslinked butyl rubber). Examples thereof include these vulcanized products and modified products (for example, those modified with functional groups such as hydroxyl group, carboxyl group, amino group and epoxy group). Among these, polyisobutylene (PIB) is preferable because it does not contain a double bond in the main chain and has excellent weather resistance.

The degree of polydispersity of the isobutylene polymer can be calculated from the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the isobutylene polymer. In the present invention, the polydispersity (Mw / Mn) of the isobutylene polymer is 4 or less, preferably 3.5 or less, and more preferably 3 or less. The lower limit of the degree of polydispersity is not particularly limited and may be 1 or more. In the present invention, when the polydispersity of the isobutylene polymer is 4 or less, the durability of the rubber-based pressure-sensitive adhesive layer obtained from the rubber-based pressure-sensitive adhesive composition is improved. This is because the low molecular weight component is reduced in the rubber-based pressure-sensitive adhesive composition by using the isobutylene-based polymer having a polydispersity of 4 or less, and the rubber-based pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition has a reduced degree of low molecular weight. It is considered that this is because it is possible to suppress the formation of a fragile layer formed from a low molecular weight component.

As the isobutylene polymer having a polydispersity of 4 or less, for example, a commercially available product such as OPPANOL N series manufactured by BASF can be used. Specifically, OPPANOL N50 (Mw / Mn: 2) manufactured by BASF can be used. .3), OPPANOL N80 (Mw / Mn: 2.4), OPPANOL N100 (Mw / Mn: 2.9) and the like can be mentioned.

The weight average molecular weight (Mw) of the isobutylene polymer is preferably 500,000 or more, preferably 550,000 or more, more preferably 700,000 or more, and further preferably 1 million 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. It is preferable that the weight average molecular weight of the isobutylene polymer is 500,000 or more because the pressure-sensitive adhesive composition tends to have more excellent durability during high-temperature storage.

The number average molecular weight (Mn) of the isobutylene polymer is preferably 200,000 or more, more preferably 300,000 or more, and further preferably 400,000 or more. The upper limit of the number average molecular weight is not particularly limited, but is preferably 3 million or less, more preferably 1 million or less, and even more preferably 700,000 or less. It is preferable to set the number average molecular weight of the isobutylene polymer to 200,000 or more because the cohesive force of the polymer can be improved and problems such as peeling during high-temperature storage can be suppressed.

The content of the isobutylene polymer in the rubber-based polymer is preferably 60% by weight or more, more preferably 80% by weight or more, and more preferably 90% by weight or more in the rubber-based base polymer. More preferably, 100% by weight (that is, the rubber-based base polymer consists only of the isobutylene-based polymer having a polydispersity of 4 or less) is particularly preferable. Further, the upper limit value is not particularly limited, and may be, for example, 100% by weight or less.

Further, the rubber-based pressure-sensitive adhesive composition of the present invention may contain a rubber-based polymer other than the isobutylene-based polymer. Specifically, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene- Propylene-styrene block copolymer (hydrohydrate of SEPS, SIS), styrene-ethylene-propylene block copolymer (hydrogenate of SEP, styrene-isoprene block copolymer), styrene-isobutylene-styrene block copolymer Styrene-based thermoplastic elastomers such as styrene-based block copolymers such as coalescing (SIBS) and styrene-butadiene rubber (SBR); butyl rubber (IIR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), EPR (binary system) Ethylene-propylene rubber), EPT (ternary ethylene-propylene rubber), acrylic rubber, urethane rubber, polyurethane-based thermoplastic elastomer; polyester-based thermoplastic elastomer; polymer of polypropylene and EPT (ternary-based ethylene-propylene rubber) Examples thereof include blend-based thermoplastic elastomers such as blends. These can be added within a range that does not impair the effects of the present invention, but are preferably 40% by weight or less, more preferably 20% by weight or less, and 10% by weight in the rubber-based base polymer. The following is more preferable, and it is not necessary to include it (that is, 0% by weight).

The content of the rubber-based base polymer is not particularly limited, but is preferably 40% by weight or more, more preferably 50% 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, and particularly preferably 80% by weight or more. The upper limit of the content of the rubber-based base polymer is not particularly limited, and is preferably 100% by weight or less, and more preferably 90% by weight or less.

Moisture permeability of the rubber-based pressure-sensitive adhesive layer having a thickness of 50μm formed from the rubber-based pressure-sensitive adhesive ^{composition, 50g / (m 2 · day} ) or less, preferably 30g ^/ (m 2 · day) or less, 20 g / ( m is more preferably ² · day) or less, more preferably 15g ^/ (m 2 · day) or less. 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 it can suppress deterioration due to the above. The moisture permeability was measured at 40 ° C. and 92% R.M. at a thickness of the rubber-based pressure-sensitive adhesive layer of 50 μm. 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.

(2) Adhesive-imparting agent A tackifier can be added to the rubber-based pressure-sensitive adhesive composition of the present invention. The tackifier may include a tackifier containing a terpene skeleton, a tackifier containing a rosin skeleton, and at least one tackifier selected from the group consisting of hydrogenated products thereof. 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 here include hydrides of terpene polymers, other modified terpene resins, and hydrogenated terpene phenolic 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. Specifically, gum rosin, wood rosin, 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 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. The detailed principle of this is unknown, but it is considered that the cyclohexanol skeleton has a better balance of compatibility with the isobutylene-based polymer, which is the base polymer, 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 additive 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 90 ° C. or higher, and more preferably about 100 ° C. or higher. It is preferable that the softening point of the tackifier is 90 ° 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 even more preferably 2000 or more. It is preferable that the weight average molecular weight of the tackifier is in the above range because the compatibility with the isobutylene polymer is good and problems such as whitening do not occur.

The amount of the tackifier added is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, and 20 parts by weight or less with respect to 100 parts by weight of the solid content of the rubber-based base polymer. It is more preferable to have. 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 aliphatic 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 may be used in an amount of about 30 parts by weight or less with respect to 100 parts by weight of the solid content of the rubber-based base polymer. it can.

(3) Hydrogen Extraction Type Photopolymerization Initiator A hydrogen extraction type photopolymerization initiator can be added to the rubber-based pressure-sensitive adhesive composition of the present invention. The hydrogen abstraction type photopolymerization initiator can extract hydrogen from an isobutylene polymer such as polyisobutylene without cleaving the initiator itself by irradiating it with active energy rays to create a reaction point in the polymer. It is a thing. By forming the reaction point, the cross-linking reaction of the polymer 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 isobutylene polymer used in the present invention, the main chain of the isobutylene polymer is cleaved by the photopolymerization initiator in which radicals are generated, and the isobutylene polymer cannot be crosslinked. .. In the present invention, the isobutylene polymer can be crosslinked as described above by using a hydrogen abstraction type photopolymerization initiator.

Examples of the hydrogen abstraction type photopolymerization initiator include acetphenone, 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, Aminobenzophenone compounds such as 4'-bis (dimethylamino) benzophenone, 4,4'-diethylaminobenzophenone; 10-butyl-2-chloroacrydone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphor Kinones and the like; aromatic ketone compounds such as acetonafton and 1-hydroxycyclohexylphenyl ketone; 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 rubber-based base polymer. It is preferably 0.01 to 10 parts by weight, and 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 crosslinking 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. ..

(4) 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 radical polymerizable compound functions as a cross-linking agent for isobutylene-based polymers.

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, esterified products of (meth) acrylic acid and polyhydric alcohol are preferable from the viewpoint of compatibility with isobutylene-based polymers, and bifunctional (meth) acrylates and (meth) acryloyl having two (meth) acryloyl groups are preferable. Trifunctional (meth) acrylates having three or more groups are more preferable, and tricyclodecanedimethanol di (meth) acrylate and trimethylolpropane tri (meth) acrylate are particularly preferable.

The content of the polyfunctional radical polymerizable compound is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, and 10 parts by weight or less with respect to 100 parts by weight of the rubber-based base polymer. Is even more preferable. The lower limit of the content of the polyfunctional radical 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 rubber-based base polymer, and is 0. It is more preferably 5 parts by weight or more, and further preferably 1 part by weight or more. When the content of the polyfunctional radical polymerizable compound is in 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.

(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 an amount of about 50 to 95% by weight, more preferably about 70 to 90% by weight, in the rubber-based pressure-sensitive adhesive composition. 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. 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.

The moisture permeability of the rubber-based pressure-sensitive adhesive layer of the present invention is as described above.

3. 3. Method for Producing Rubber Adhesive Layer The method for producing the rubber adhesive layer of the present invention is not particularly limited. For example, the rubber adhesive composition is applied to various supports or the like, and a solvent or the like is applied by heating and drying. By removing it, a rubber-based pressure-sensitive adhesive layer can be formed (manufacturing method 1). Further, when the rubber-based pressure-sensitive adhesive composition of the present invention contains the hydrogen-drawing type initiator, the rubber-based pressure-sensitive adhesive composition is irradiated with active energy rays to crosslink the isobutylene-based polymer. A rubber-based pressure-sensitive adhesive layer can be manufactured (manufacturing method 2). Hereinafter, each manufacturing method will be described.

(1) Manufacturing method 1
Various methods are used as the method for applying the 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.

The heating and drying temperature is preferably about 30 ° C. to 200 ° C., more preferably 40 ° C. to 180 ° C., and even more preferably 80 ° C. to 150 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained. 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.

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 released from a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, silica powder, or the like, as well as antifouling treatment, coating type, kneading type, or vapor deposition. Antistatic treatment such as mold can also be performed. 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 of the rubber-based pressure-sensitive adhesive layer of the present invention is as described above.

(2) Manufacturing method 2
Irradiation of the active energy rays is usually performed by applying the rubber-based pressure-sensitive adhesive composition to various supports or 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 the active energy ray.

Examples of the method for applying the rubber-based pressure-sensitive adhesive composition include the same method as in the production method 1.

When the coating layer of the rubber-based pressure-sensitive adhesive composition is irradiated with active energy rays, 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.

Examples of the support include those described above.

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

4. Adhesive film The adhesive film of the present invention is characterized by having a support made of a plastic base material and the rubber-based pressure-sensitive adhesive layer on at least one side of the support.

As a method of forming the rubber-based pressure-sensitive adhesive layer on the support, the rubber-based pressure-sensitive adhesive composition is applied on the support and the solvent or the like is removed by heating and drying, or an active energy ray is applied. By irradiating, a rubber-based pressure-sensitive adhesive layer can be formed on the support.

The rubber-based pressure-sensitive adhesive composition, the rubber-based pressure-sensitive adhesive layer, and a method for producing the same are as described above.

The plastic base material is not particularly limited as long as it can be formed in the form of a sheet or a film, and for example, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and ethylene. -Polyester films such as propylene copolymers, ethylene / 1-butene copolymers, ethylene / vinyl acetate copolymers, ethylene / ethyl acrylate copolymers, ethylene / vinyl alcohol copolymers, polyethylene terephthalates, polyethylene naphthalates, Examples thereof include polyester films such as polybutylene terephthalate, polyacrylate films, polystyrene films, nylon 6, nylons 6 and 6, polyamide films such as partially aromatic polyamides, polyvinyl chloride films, polyvinylidene chloride films and polycarbonate films.

The thickness of the film is usually about 5 to 200 μm, preferably about 10 to 100 μm.

For the plastic base material, if necessary, a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, mold release with silica powder, antifouling treatment, acid treatment, alkali treatment, primer treatment, etc. It is also possible to perform easy-adhesion treatment such as corona treatment, plasma treatment and ultraviolet treatment, and antistatic treatment such as coating type, kneading type and vapor deposition type.

The adhesive film of the present invention can be used as various surface protective sheets, and can also be used as a removable sheet with less contamination. By using such a removable sheet for an antireflection film, antireflection glass, etc. that are easily contaminated, it can be suitably used as a releasable sheet with extremely little contamination. Further, it can be more preferably used by further cross-linking with a rubber-based base polymer having a small degree of polydispersity.

5. 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 on the optical film and the solvent or the like is removed by heating and drying, or an active energy ray is applied. By irradiating, a rubber-based pressure-sensitive adhesive layer can be formed on the optical film. Further, as described above, it is also possible to form a rubber-based pressure-sensitive adhesive layer on a support or the like and transfer the rubber-based pressure-sensitive adhesive layer 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.

The rubber-based pressure-sensitive adhesive composition, the rubber-based pressure-sensitive adhesive layer, and a method for producing the same are as described above.

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 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. As the polarizer, for example, a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymerization system partially saponified film, and a bicolor property of iodine or a bicolor dye are used. Examples thereof include a uniaxially stretched film 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 unevenness in thickness, is excellent in visibility, is excellent in durability because there is little dimensional change, and can be made thinner as a polarizing film.

Typical examples of the thin polarizing element include JP-A-51-069644 and JP-A-2000-338329, International Publication No. 2010/100917, 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, and thus International Publication No. 2010/100917 pamphlet. 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-2014-509328 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 polycarbonate polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, and sulfone 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 surfaces, 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 and an electron beam curable adhesive. 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 polarizing film 1 with an adhesive layer of the present invention has the rubber-based adhesive. It is preferable that the agent layer 3 is formed on the side of the polarizer 4 that does not have the protective film 5 (that is, the side of the polarizer 4) (that is, the rubber-based pressure-sensitive adhesive layer 3, the polarizer 4, and the protective film 5). However, it is preferable that they are laminated in this order). 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 water 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.

Further, a retardation film can be further used for the polarizing film with the pressure-sensitive adhesive layer. For example, when a single-sided protective polarizing film is used as the polarizing film, as shown in FIG. 2, the rubber-based pressure-sensitive adhesive layer 3 It is preferable to laminate the retardation film 6, the polarizer 4, and the protective film 5 in this order.

The retardation film is preferably a film that can function as a λ / 4 plate. The in-plane retardation Re (550) of such a retardation film measured with light having a wavelength of 550 nm at 23 ° C. is preferably 100 to 180 nm, more preferably 110 to 170 nm, and 120 to 160 nm. It is more preferably 135 to 155 nm, and particularly preferably 135 to 155 nm. The in-plane phase difference Re is determined by Re = (nx−ny) × d (d: film thickness (nm)). The retardation film capable of functioning as the λ / 4 plate can be laminated so that its slow phase axis is oblique to the absorption axis of the polarizer (for example, 45 ° direction).

Further, the retardation film typically has a refractive index ellipsoid of nx> ny = nz or nx> ny> nz. Here, nx is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and ny is the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advancing axis direction). It is a refractive index, and nz is a refractive index in the thickness direction. Further, in the present specification, ny = nz includes not only exactly equal cases but also substantially equal cases.

The Nz coefficient of the retardation film is, for example, preferably 0.9 to 2, more preferably 1 to 1.5, and even more preferably 1 to 1.3. Here, the Nz coefficient is obtained by Nz = Rth / Re. The Rth is a phase difference in the thickness direction, and is determined by Rth = (nx−nz) × d (d: film thickness (nm)).

As the retardation film, a known retardation film can be used, and a retardation film using a polymer or a liquid crystal compound having an inverse wavelength dispersion characteristic, or a λ / 2 plate and a λ / 4 plate laminated. A retardation film is preferably used. By using these retardation films, circularly polarized light can be obtained over a wide wavelength range, and excellent color can be realized.

As a material for forming a retardation film in which a λ / 2 plate and a λ / 4 plate are laminated, either a polymer or a liquid crystal compound can be used, but a liquid crystal compound is preferable from the viewpoint of thinning.

Further, in the present invention, a second retardation film having a refractive index characteristic of nz> nz ≧ ny can be used together with the retardation film (sometimes referred to as a first retardation film). By providing such a second retardation film, the function of the λ / 4 plate (first retardation film) can be sufficiently maintained even for light incident from an oblique direction, and as a result, it is very much. It is possible to realize an excellent oblique reflection hue. The retardation Rth (550) in the thickness direction of the second retardation film is preferably −260 nm to −10 nm, more preferably −200 nm to −20 nm, further preferably −180 nm to −30 nm, and −180 nm to −180 nm. -60 nm is particularly preferable.

In one embodiment, the second retardation film exhibits a relationship of refractive index nx = ny. Here, "nx = ny" includes not only the case where nx and ny are exactly equal, but also the case where nx and ny are substantially equal. Specifically, it means that Re (550) is less than 10 nm. In another embodiment, the second retardation film exhibits a relationship of refractive index nx> ny. In this case, the in-plane retardation Re (550) of the second retardation film is preferably 10 nm to 150 nm, more preferably 10 nm to 80 nm. Preferably, the second retardation film exhibits a relationship in which its refractive index is nx> ny. By using such a retardation film, the geometrical deviation of the slow axis of the first retardation film when viewed from an oblique direction can be suitably compensated, and the antireflection function in the oblique direction is significantly enhanced. Because it can be improved. As described above, when nx and ny are substantially equal to each other and when nx> ny, a slow phase axis may appear in the second retardation film. In this case, the slow axis of the second retardation film may be laminated so as to be parallel or orthogonal to the absorption axis of the polarizer.

The second retardation film can be made of any suitable material. A liquid crystal layer fixed in a homeotropic orientation is preferable. The liquid crystal material (liquid crystal compound) that can be homeotropically oriented may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the liquid crystal layer include the liquid crystal compounds and the methods for forming the liquid crystal compounds described in [0020] to [0042] of JP-A-2002-333642. In this case, the thickness is preferably 0.1 μm to 5 μm, more preferably 0.2 μm to 3 μm. Since the liquid crystal layer has an extremely thin thickness and desired optical characteristics can be obtained, it is possible to realize a significant reduction in the thickness of the circularly polarizing plate.

As another preferable specific example, the second retardation film may be a retardation film formed of the fumaric acid diester resin described in JP2012-32784A. In this case, the thickness is preferably 5 μm to 50 μm, more preferably 10 μm to 35 μm. Since the retardation film formed of the fumaric acid diester resin has a wavelength dispersion characteristic close to flat dispersion, it has an advantage that the hue change is small.

Examples of the optical film other than the polarizing plate film include a reflector, an antitransmissive plate, a retardation film other than the retardation film (including a wavelength plate such as 1/2 or 1/4), and a viewing angle compensation film. Examples thereof include an optical layer that may be used for forming a liquid crystal display device such as a brightness improving film. 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.

6. Optical member The optical member of the present invention has a temperature of 40 ° C. and 92% R. H. The film has a moisture permeability of 1 g / (m ² · day) or less, and the rubber-based pressure-sensitive adhesive layer is provided on at least one side of the film.

The method for forming the rubber-based pressure-sensitive adhesive layer on the film, the rubber-based pressure-sensitive adhesive composition, and the rubber-based pressure-sensitive adhesive layer are as described above.

40 ° C., 92% R. 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.

7. 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, a colored laminate was produced by dyeing the stretched 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 30 μm-thick polyvinyl alcohol film was stretched up to 3 times between rolls having different speed ratios while dyeing in an iodine solution at 30 ° C. and a 0.3% concentration for 1 minute. 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. One side of the polarizer is hard-coded and the other side is saponified with a 25 μm-thick triacetyl cellulose film, and the other side of the polarizer is a 13 μm cycloolefin resin film, polyvinyl alcohol. Both protective polarizing films (polarizing film (2)) were produced by laminating with a system adhesive. 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 (Preparation of First Phase Difference Film)
37.5 parts by mass of isosorbide (ISB), 91.5 parts by mass of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (BHEPF), 8.4 parts by mass of polyethylene glycol (PEG) having an average molecular weight of 400. , 105.7 parts by mass of diphenyl carbonate (DPC) and 0.594 parts by mass of cesium carbonate (0.2% by mass aqueous solution) as a catalyst were put into the reaction vessel, and the first stage of the reaction was carried out under a nitrogen atmosphere. As a second step, the heat medium temperature of the reaction vessel was set to 150 ° C., and the raw materials were dissolved with stirring as necessary (about 15 minutes).

Next, the pressure inside the reaction vessel was changed from normal pressure to 13.3 kPa, and the heat medium temperature of the reaction vessel was raised to 190 ° C. in 1 hour, and the generated phenol was extracted from the reaction vessel. After maintaining the temperature inside the reaction vessel at 190 ° C. for 15 minutes, as the second step, the pressure inside the reaction vessel was set to 6.67 kPa, and the heat medium temperature of the reaction vessel was raised to 230 ° C. in 15 minutes. The generated phenol was extracted from the reaction vessel. Since the stirring torque of the stirrer increased, the temperature was raised to 250 ° C. in 8 minutes, and the pressure in the reaction vessel was reduced to 0.200 kPa or less in order to remove the generated phenol. After reaching the predetermined stirring torque, the reaction is terminated, the produced reaction product is extruded into water, and then pelletized, and BHEPF / ISB / PEG = 42.9 mol% / 52.8 mol% / 4.3. A polycarbonate resin A containing a structural unit derived from a dihydroxy compound in a molar% ratio was obtained. The glass transition temperature of the obtained polycarbonate resin A was 126 ° C., and the reducing viscosity was 0.372 dL / g. After vacuum-drying the obtained polycarbonate resin A at 80 ° C. for 5 hours, a single-screw extruder (screw diameter: 25 mm, cylinder set temperature: 220 ° C., manufactured by Isuzu Kakohki Co., Ltd.), T-die (width: 300 mm, A polycarbonate resin film having a length of 3 m, a width of 300 mm, and a thickness of 120 μm was produced using a film forming apparatus equipped with a set temperature (set temperature: 220 ° C.), a chill roll (set temperature: 120 to 130 ° C.), and a winder. The water absorption rate of the obtained polycarbonate resin film was 1.2%.

The obtained polycarbonate resin film was cut into a length of 300 mm and a width of 300 mm, and subjected to longitudinal stretching at a temperature of 136 ° C. and a magnification of 2 times using a lab stretcher KARO IV (manufactured by Bruckner) to obtain a retardation film. .. The obtained retardation film has a Re (550) of 141 nm and a Rth (550) of 141 nm (nx: 1.5969, ny: 1.5942, nz: 1.5942), and has a refractive index of nx> ny = nz. The characteristics were shown. The Re (450) / Re (550) of the obtained retardation film was 0.89 (furthermore, the retardation variation by the environmental test was 5 nm).

Production Example 4 (Preparation of a second retardation layer (second retardation film))
20 parts by weight of the side chain type liquid crystal polymer represented by the following chemical formula (I) (numbers 65 and 35 in the formula represent mol% of the monomer unit and are conveniently represented by a block polymer, weight average molecular weight: 5000). , 80 parts by weight of a polymerizable liquid crystal (trade name: Palocolor LC242, manufactured by BASF) showing a nematic liquid crystal phase and 5 parts by weight of a photopolymerization initiator (trade name: Irgacure 907, manufactured by Ciba Speciality Chemicals) by 200 weight by cyclopentanone. A liquid crystal coating solution was prepared by dissolving in the part. Then, the liquid crystal is formed by applying the coating liquid to a base film (norbornene resin film, trade name: Zeonex, manufactured by Nippon Zeon Corporation) with a bar coater, and then heating and drying at 80 ° C. for 4 minutes. Oriented. By irradiating the liquid crystal layer with ultraviolet rays and curing the liquid crystal layer, a liquid crystal solidified layer (thickness: 0.58 μm) to be a second retardation layer was formed on the base material. Re (550) of this layer is 0 nm, Rth (550) is -71 nm (nx: 1.5326, ny: 1.5326, nz: 1.6550), and exhibits a refractive index characteristic of nz> nx = ny. It was.

Production Example 5 (Production of retardation film A)
After adhering the second retardation layer (liquid crystal solidifying layer) obtained in Production Example 4 to the first retardation film obtained in Production Example 3 via an acrylic adhesive, the above-mentioned base material. The film was removed to obtain a laminate (phase difference film A) in which the liquid crystal solidified layer was transferred to the first retardation film. The obtained retardation film A was composed of a first retardation film / an acrylic pressure-sensitive adhesive layer / a second retardation layer. The Re (550) of the obtained retardation film A was 141 nm, and the Rth (550) was 70 nm.

Production Example 6 (Production of single-sided protective polarizing film with retardation film)
The retardation film A obtained in Production Example 5 is placed on the polarizing film (polarizer) side of the one-side protective polarizing film (polarizing film (1)) obtained in Production Example 1 via a polyvinyl alcohol-based adhesive. The retardation film of No. 1 was bonded. Here, the retardation axis of the retardation film A is attached so as to be 45 ° counterclockwise with respect to the absorption axis of the polarizer, and the single-sided protective polarizing film with the retardation film (polarizing film (3)) is formed. Made. The composition of the polarizing film (3) was a protective film / adhesive layer / polarizer / adhesive layer / retardation film A.

Example 1
(Preparation of rubber-based composition)
Adjust the toluene solution (solid content: 13% by weight) of polyisobutylene (trade name: OPPANOL N50, Mw: 560,000, Mn: 240,000, Mw / Mn: 2.3, manufactured by BASF) to make it rubber-based. A pressure-sensitive adhesive composition (solution) was prepared.

(Formation of rubber adhesive sheet)
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 Plastics 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 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 Plastics Co., Ltd.) having a thickness of 38 μm obtained by peeling one side of the adhesive sheet with silicone is in contact with the peeled surface and the adhesive layer. It was pasted together. The polyester film coated on both sides of the pressure-sensitive adhesive layer functions as a release liner (separator).

Examples 2 and 3
A rubber-based pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the polyisobutylene (OPPANOL N50) used in Example 1 was changed to the polyisobutylene shown in Table 1.

Example 4
(Preparation of rubber-based composition)
100 parts by weight of polyisobutylene (trade name: OPPANOL N50, Mw: 560,000, Mn: 240,000, Mw / Mn: 2.3, manufactured by BASF) and completely hydrogenated terpene phenol (softened) as a tackifier. A toluene solution (adhesive solution) containing 10 parts by weight of (completely hydrogenated terpene phenol) having a point: 135 ° C. and a hydroxyl value: 160 was adjusted so that the solid content was 13% by weight, and the pressure-sensitive adhesive composition (solution) was adjusted. ) Was prepared.

Using the obtained rubber-based pressure-sensitive adhesive composition, a rubber-based pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the film thickness was set to 25 μm.

Examples 5-7
A rubber-based pressure-sensitive adhesive sheet was produced in the same manner as in Example 4 except that the type of polyisobutylene, the amount of completely hydrogenated terpene phenol added, and the film thickness were changed as shown in Table 1.

Example 8
(Preparation of rubber-based composition)
100 parts by weight of polyisobutylene (trade name: OPPANOL N80, Mw: 1,050,000, Mn: 440,000, Mw / Mn: 2.4, manufactured by BASF) and fully hydrogenated terpene phenol as a tackifier. (Softening point: 135 ° C., hydroxyl value: 160, completely hydrogenated terpenephenol) 5 parts by weight, tricyclodecanedimethanol diacrylate as a polyfunctional radically polymerizable compound (trade name: NK ester A-DCP, bifunctional) Acrylate, molecular weight: 304, 5 parts by weight of Shin-Nakamura Chemical Industry Co., Ltd., and 1 part of benzophenon (manufactured by Wako Pure Chemical Industries, Ltd.), which is a hydrogen abstraction type photopolymerization initiator, in a toluene solution (adhesive solution). ) Was adjusted so that the solid content was 13% 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 Plastics Co., Ltd.) having a thickness of 38 μm in which one side is peeled 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 Plastics 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 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).

Irradiation with ultraviolet rays at room temperature gave a rubber-based pressure-sensitive adhesive sheet composed of a separator / rubber-based pressure-sensitive adhesive layer / separator. The ultraviolet irradiation had a light intensity of 1000 mJ / cm ² in the UVA region.

Examples 9-13
A rubber-based pressure-sensitive adhesive sheet was produced in the same manner as in Example 8 except that the compositions shown in Table 1 were adopted.

Comparative Examples 1-3
A rubber-based pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the compositions were shown in Table 1.

Comparative Example 4
(Making acrylic adhesive sheet)
In a separable flask equipped with a thermometer, a stirrer, 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.

The obtained acrylic pressure-sensitive adhesive composition is applied to a peel-treated surface of a polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 38 μm in which one side is peeled with silicone to form a coating layer. did. 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>
One of the release liners of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples was peeled off to expose the pressure-sensitive adhesive surface, and the pressure-sensitive adhesive surface was attached to the polarizing element of the polarizing film (1) obtained in Production Example 1. .. Then, the other release liner was peeled off to obtain a measurement sample 1 (single protective polarizing film).

Further, one of the release liners of the adhesive sheets obtained in Examples and Comparative Examples is peeled off to expose the adhesive surface, and the adhesive sheet is bonded to the cycloolefin resin film of the polarizing film (2) by the adhesive surface. It was. Then, the other release liner was peeled off to obtain a measurement sample 2 (both protective polarizing films).

Further, one of the release liners of the adhesive sheets obtained in Examples and Comparative Examples was peeled off to expose the adhesive surface, and the adhesive sheet was attached to the retardation film A of the polarizing film (3) by the adhesive surface. .. Then, the other release liner was peeled off to obtain a measurement sample 3 (single protective polarizing film with a retardation film).

The obtained measurement samples 1 to 3 were attached to glass plates, respectively, and the state after being charged in an environment of 85 ° C. for 500 hours was observed visually or using a magnifying glass (20 times). Evaluation was made according to the following evaluation criteria.
⊚: No defects (foaming, peeling, etc.) occurred even after checking with a magnifying glass.
〇: No defects could be visually confirmed, but when confirmed with a magnifying glass, there were some defects to the extent that there was no problem in use.
X: A defect was visually confirmed.

<Glue misalignment>
The measurement samples 1 to 3 obtained in the durability test were put into an environment of 85 ° C. for 500 hours, and the state of the end portion was observed using a magnifying glass (20 times). Evaluation was made according to the following evaluation criteria.
⊚: The occurrence of glue misalignment could not be visually confirmed, but when it was confirmed with a magnifying glass, some glue misalignment occurred to the extent that there was no problem in use.
◯: Glue misalignment within the range where no problem occurred could be visually confirmed.
X: A defect was confirmed due to a deviation between the polarizing plate end and the glue end.

<Humidity permeability>
One of the release liners of the adhesive sheets obtained in Examples and Comparative Examples was peeled off to expose the adhesive surface, and the adhesive sheet was made into a triacetyl cellulose film (TAC film, thickness 25 μm, Konica Minolta Co., Ltd.) by the adhesive surface. Made). 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 N50: Polyisobutylene (Mw: 560,000, Mn: 240,000, Mw / Mn: 2.3, manufactured by BASF)
OPPANOL N80: Polyisobutylene (Mw: 1,050,000, Mn: 440,000, Mw / Mn: 2.4, manufactured by BASF)
OPPANOL N100: Polyisobutylene (Mw: 1,550,000, Mn: 530,000, Mw / Mn: 2.9, manufactured by BASF)
OPPANOL B50: Polyisobutylene (Mw: 535,000, Mn: 111,458, Mw / Mn: 4.8, manufactured by BASF)
OPPANOL B80: Polyisobutylene (Mw: 1,150,000, Mn: 239,583, Mw / Mn: 4.8, manufactured by BASF)
OPPANOL B100: Polyisobutylene (Mw: 1,680,000, Mn: 365,217, Mw / Mn: 4.6, manufactured by BASF)
<Other polymers>
Acrylic resin: Acrylic pressure-sensitive adhesive composition obtained in Comparative Example 4 <Adhesive-imparting agent>
Completely hydrogenated terpene phenol: Completely hydrogenated terpene phenol having a softening point of 160 ° C. and a hydroxyl value of 60 <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.)
<Photopolymerization initiator>
Benzophenone: Hydrogen abstraction photopolymerization initiator

1 Polarizing film with adhesive layer 2 Polarizing film 3 Rubber adhesive layer 4 Polarizer 5 Protective film 6 Phase difference film

Claims (13)

A rubber-based pressure-sensitive adhesive composition containing a rubber-based base polymer.
The rubber-based base polymer contains an isobutylene-based polymer having a weight average molecular weight of 1 million or more and a polydispersity (weight average molecular weight / number average molecular weight) of 3 or less .
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 50 g / (m ² · day) or less. The rubber-based pressure-sensitive adhesive composition according to claim 1, which comprises a pressure-sensitive adhesive. The claim is characterized in that the tackifier is 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. Item 2. The rubber-based pressure-sensitive adhesive composition according to Item 2. The rubber-based pressure-sensitive adhesive composition according to claim 2 or 3, wherein the softening point of the pressure-sensitive adhesive is 90 ° C. or higher. The rubber-based pressure-sensitive adhesive composition according to any one of claims 1 to 4, which comprises a hydrogen-extracting photopolymerization initiator. A rubber-based pressure-sensitive adhesive layer formed from the rubber-based pressure-sensitive adhesive composition according to any one of claims 1 to 5. A pressure-sensitive adhesive film comprising a support made of a plastic base material and the rubber-based pressure-sensitive adhesive layer according to claim 6 on at least one surface of the support. An optical film with a rubber-based pressure-sensitive adhesive layer, which comprises the rubber-based pressure-sensitive adhesive layer according to claim 6 on at least one surface of the optical film and the optical film. The optical film with a rubber-based pressure-sensitive adhesive layer according to claim 8, 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.
The optical film with a rubber-based pressure-sensitive adhesive layer according to claim 9, wherein the rubber-based pressure-sensitive adhesive layer, a polarizing element, and a protective film are laminated in this order. The optical film with a rubber-based pressure-sensitive adhesive layer further contains a retardation film.
The optical film with a rubber-based pressure-sensitive adhesive layer according to claim 10, wherein the rubber-based pressure-sensitive adhesive layer, a retardation film, a polarizer, and a protective film are laminated in this order. 40 ° C., 92% R. H. A film having a moisture permeability of 1 g / (m ² · day) or less, and an optical member having the rubber-based pressure-sensitive adhesive layer according to claim 6 on at least one side of the film. An image display device comprising at least one optical film with a rubber-based pressure-sensitive adhesive layer according to any one of claims 8 to 11 or at least one optical member according to claim 12.

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