JP6609405B2 - Adhesive composition, adhesive layer, adhesive optical film, adhesive polarizing plate, and image display device - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer, an optical member, and an image display device.

  More specifically, the present invention is formed of a pressure-sensitive adhesive composition for an optical film such as a polarizing plate, which is excellent in reworkability for a thin image display device and excellent in durability in an adhesive state, and the composition. The present invention relates to an optical member such as an adhesive polarizing plate having an adhesive layer. Furthermore, the present invention also relates to an image display device such as a liquid crystal display device, an organic EL display device, and a PDP using the optical member.

  Optical members such as a polarizing plate having a polarizer and various optical films for improving display quality of a display are attached to a liquid crystal panel such as a liquid crystal display device via an adhesive. Moreover, since it has the merit that a drying process is not required for fixing an optical film, the adhesive is generally an optical member provided in advance as an adhesive layer on one side of the optical film. Yes.

  For example, in Patent Document 1, a pressure-sensitive adhesive composition containing an acrylic polymer and a polymer-type silane coupling agent having a siloxane skeleton in the main chain and an alkoxyl group, an epoxy group, a polyether group, etc. in the side chain (patent Reference 1), an adhesive composition containing an acrylic polymer and a silicone oligomer (see Patent Documents 2 to 4), or an adhesive composition containing an acrylic copolymer containing a carboxyl group and a silane coupling agent (patent Various pressure-sensitive adhesive compositions for optical films have been reported such as literatures 5 to 6).

  However, when the optical film is bonded to a liquid crystal display device or the like, for example, when the bonding position is wrong or a foreign object is caught in the bonding surface, or when the liquid crystal cell is reused, the optical film is used. It is peeled off from the liquid crystal display device or the like, and needs to be bonded again. In particular, in recent years, in addition to the manufacturing process of conventional liquid crystal display devices, the use of liquid crystal display devices such as thin liquid crystal panels using chemically etched glass has increased, and optical films have become thin and brittle. In contrast to such thin liquid crystal display devices and thin optical films, the use of conventional adhesives aimed only at durability would cause the thin liquid crystal display device and thin optical film to break or break. Came out. For this reason, as a necessary characteristic of the pressure-sensitive adhesive, re-peelability (also referred to as “reworkability”) that can easily peel off the optical film without any adhesive residue from the liquid crystal display device or the like is required in the peeling process. It is becoming.

  In addition, the adhesive also has durability in the adhesive state in which the adhesive does not suffer any problems such as peeling or floating due to the adhesive and the durability test by heating and humidification normally performed as an environmental promotion test. It is requested.

  Thus, the pressure-sensitive adhesive is required to satisfy both reworkability and durability.

JP 07-331206 A JP 2006-316256 A JP 2010-007044 A JP 2012-012537 A International Publication No. 2012/26456 JP 2008-176173 A

  However, in any of the pressure-sensitive adhesive compositions according to any of the patent documents, it has not been possible to achieve both reworkability and durability required for a particularly thin image display device and a thin optical member.

  Therefore, the present invention has been made in view of the above circumstances, and particularly in a pressure-sensitive adhesive composition that can also be used for a thin image display device and a thin optical member, reworkability that can be easily peeled off, and an adhesive state It aims at providing the means which can make the endurance with respect to the endurance test by heating, humidification, etc. in both.

  Another object of the present invention is to provide an adhesive layer formed from such an adhesive composition, an optical member such as an adhesive polarizing plate having the adhesive layer, and an image display device using the optical member. Is to provide.

  The present inventors have conducted intensive research to solve the above problems. As a result, it has been found that the above-mentioned problems can be solved by the pressure-sensitive adhesive composition having specific constituent components, and the present invention has been completed.

  That is, 100 parts by weight of the pressure-sensitive adhesive resin (A), 0.1 to 20 parts by weight of a silicone alkoxy oligomer (B) having an epoxy equivalent of 100 to 2000 g / mol and an alkoxyl group content of 5 to 60% by weight, And the pressure-sensitive adhesive resin (A) is an acrylic pressure-sensitive adhesive resin (A1), urethane pressure-sensitive adhesive resin (A2), and polyester-based pressure-sensitive adhesive resin (A3) obtained by polymerizing a monomer that does not contain a carboxyl group. The pressure-sensitive adhesive composition is one or more selected from the group consisting of:

  According to the present invention, particularly in a pressure-sensitive adhesive composition that can be used for a thin image display device and a thin optical member, reworkability that can be easily peeled, and durability test by heating and humidification in an adhesive state, etc. Both durability can be achieved.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

{Adhesive composition}
The pressure-sensitive adhesive composition of the present invention comprises 100 parts by weight of a pressure-sensitive adhesive resin (A), a silicone alkoxy oligomer (B) having an epoxy equivalent of 100 to 2000 g / mol and an alkoxyl group content of 5 to 60% by weight. 1-20 parts by weight, and the pressure-sensitive adhesive resin (A) is obtained by polymerizing a monomer that does not contain a carboxyl group, an acrylic pressure-sensitive adhesive resin (A1), a urethane-based pressure-sensitive adhesive resin (A2), and It is characterized in that it is one or more selected from the group consisting of polyester-based pressure-sensitive adhesive resins (A3). The pressure-sensitive adhesive composition of the present invention is excellent in reworkability and durability due to such specific constituent components.

  The mechanism that can solve the problem of the present invention is presumed as follows, but is not limited thereto.

  That is, when a carboxyl group is present in the side chain of the pressure-sensitive adhesive resin (A), the alkoxyl group of the silicone alkoxy oligomer (B) reacts with the carboxyl group, and a silanol group is present in the side chain of the silicone alkoxy oligomer (B). Generated. Thereby, since content of the alkoxyl group which contributes to rework property decreases, the rework property of an adhesive composition will fall. In addition, silanol groups are highly reactive. For example, when such a pressure-sensitive adhesive composition is used for a liquid crystal panel such as glass, the side chain silanol groups and glass of the silicone alkoxy oligomer (B) are used on the glass surface. A coupling reaction is likely to occur between the surface and the silanol group. Thereby, while the adhesive force with respect to the glass surface of the said adhesive composition is improved, it is possible that rework property will fall. In addition, there are many liquid crystal display devices having an IPS panes and the like that are weak to the acidity of carboxyl groups. Then, the direction which lowers content of a carboxyl group as much as possible was employ | adopted as adhesive resin (A) to be used by the present inventors' earnest research. Here, “the direction of decreasing the carboxyl group content as much as possible” means that even if a carboxyl group is present, it is present at the end of the pressure-sensitive adhesive resin (A), and preferably no carboxyl group is present at all. is there. For this reason, the present inventors may be an acrylic pressure-sensitive adhesive resin (A1) obtained by polymerizing a monomer not containing a carboxyl group as the pressure-sensitive adhesive resin (A), or a urethane-based pressure-sensitive adhesive resin (A2). ), Polyester pressure-sensitive adhesive resin (A3), or two or more selected from the group consisting of (A1) to (A3).

  Further, from the above findings, the present inventors have analyzed the reasons why Patent Documents 1 to 6 cannot achieve both reworkability and durability. This is because the acrylic pressure-sensitive adhesive resins used in Patent Documents 1 to 6 all use acrylic acid during production, that is, a monomer containing a carboxyl group is used, so that the reworkability is deteriorated. I thought it was possible.

  Hereinafter, each component of the pressure-sensitive adhesive composition of the present invention will be described in detail.

In the present specification, “(meth) acrylate” is a general term for acrylate and methacrylate. Similarly, a compound containing (meth) such as (meth) acrylic acid is a general term for a compound having “meta” in the name and a compound not having “meta”. For this reason,"(
“Meth) acryl” includes both acrylic and methacrylic. “(Meth) acrylate” includes both acrylate and methacrylate. “(Meth) acrylic acid” includes both acrylic acid and methacrylic acid.

<Adhesive resin (A)>
In the present invention, the pressure-sensitive adhesive resin (A) includes an acrylic pressure-sensitive adhesive resin (A1), a urethane-based pressure-sensitive adhesive resin (A2), and a polyester-based pressure-sensitive adhesive resin (A3) obtained by polymerizing a monomer that does not contain a carboxyl group. ) Is one or more selected from the group consisting of:

  The weight average molecular weight of the pressure-sensitive adhesive resin (A) used in the present invention is not particularly limited, but is preferably 20,000 to 2,500,000, and more preferably 300 to 2,500,000 in the case of acrylic. It is especially preferable that it is ˜2.2 million. In the case of a urethane type and a polyester type, it is more preferably 20,000 to 100,000, and particularly preferably 30000 to 60,000. When the weight average molecular weight is within the above range, durability can be improved. In addition, in this specification, a weight average molecular weight can be measured by the method shown in an Example.

  Although it does not specifically limit as a viscosity of adhesive resin (A) used for this invention, It is preferable that it is 100-100000 mPa * s, It is more preferable that it is 300-50000 mPa * s, It is 500-30000 mPa * s. It is particularly preferred. If the viscosity is within the above range, the coated surface can be made smooth, and the uniformity of the film thickness of the coated surface can be easily obtained.

  In the present invention, the pressure-sensitive adhesive resin (A) preferably contains a hydroxyl group from the viewpoint of improving durability. In particular, when used in combination with a crosslinking agent as an isocyanate compound, which will be described later, a hydroxyl group and an isocyanate compound are crosslinked to form a network, and the durability can be further improved.

[Acrylic adhesive resin (A1)]
The acrylic pressure-sensitive adhesive resin (A1) according to the present invention is not particularly limited as long as it is a monomer that does not contain a carboxyl group, and can be produced using a known one. Specifically, it can be produced by polymerizing a (meth) acrylic monomer constituting the main skeleton and a monomer providing a side chain.

(Monomer constituting the main chain)
Examples of the (meth) acrylic monomer used in the production of the acrylic pressure-sensitive adhesive resin (A1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and iso- Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, iso-nonyl (meth) acrylate, And alkyl (meth) acrylate such as cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. In addition to these, (meth) acrylates having an aromatic group and a heterocyclic ring described in paragraphs “0036” to “0037” of JP2010-275524A are also used. These may be used alone or in combination of two or more.

  Among these, acrylic (meth) acrylates having an average carbon number of 3 to 9 are preferably used from the viewpoint of heat durability and wet heat durability.

(Monomer providing side chain)
Monomers that provide side chains used in the production of the acrylic pressure-sensitive adhesive resin (A1) include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 1,6-hexanediol mono (meth). Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethanedi (meth) acrylate, 2-hydroxypropyl (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, N-2-hydroxye (Meth) acrylamide, cyclohexanedimethanol monoacrylate and the like, and further obtained by addition reaction of glycidyl group-containing compounds such as alkyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) acrylate and (meth) acrylic acid. And vinyl compounds such as vinyl pyridine or styrene. These may be used alone or in combination of two or more.

  Among these, from the viewpoint of imparting a hydroxyl group to the pressure-sensitive adhesive resin (A), those having at least one hydroxyl group are preferred, particularly 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, N-2-hydroxyethyl (meth) acrylamide and cyclohexanedimethanol monoacrylate are preferable, and 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and N-2-hydroxyethyl (meth) acrylamide are more preferable. .

(Manufacture of acrylic adhesive resin (A1))
The method for producing the acrylic pressure-sensitive adhesive resin (A1) is not particularly limited, and is a solution polymerization method using a polymerization initiator, an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, a thin film polymerization method, a spraying method. A conventionally known method such as a polymerization method can be used. Examples of the polymerization control method include adiabatic polymerization, temperature controlled polymerization, and isothermal polymerization. In addition to the method of initiating polymerization with a polymerization initiator, a method of initiating polymerization by irradiating with radiation, electron beam, ultraviolet rays or the like can also be employed. Among these, the solution polymerization method using a polymerization initiator is preferable because the molecular weight can be easily adjusted and impurities can be reduced. For example, ethyl acetate, toluene, methyl ethyl ketone or the like is used as a solvent, and the polymerization initiator is preferably 0.01 with respect to 100 parts by weight of the total amount of raw material monomers (monomers constituting the main chain and monomers providing side chains). -0.50 weight part is added, and it is obtained by making it react at a reaction temperature of 60-90 degreeC, for example for 3 to 10 hours in nitrogen atmosphere.

  Examples of the polymerization initiator include azo compounds such as 2,2-azobisisobutyronitrile (AIBN), 2,2′-azobis (2-methylbutyronitrile), azobiscyanovaleric acid; Organics such as oxypivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, tert-butyl hydroperoxide Peroxides: inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. These may be used alone or in combination of two or more.

  When the acrylic pressure-sensitive adhesive resin (A1) is produced, the amount of the monomer that constitutes the main chain and the amount of the monomer that provides the side chain has a balance with each type, but the monomer constituting the main chain: side The weight ratio of monomers providing the chain is preferably 99.99: 0.01 to 80:20, and more preferably 99.9: 0.1 to 90:10.

[Urethane adhesive resin (A2)]
The urethane-based pressure-sensitive adhesive resin (A2) according to the present invention can be produced by reacting a polyester polyol and / or a polyether polyol with an isocyanate compound.

(Polyester polyol)
It does not specifically limit as polyester polyol used for manufacture of urethane type adhesive resin (A2), A well-known polyester polyol is used. For example, it can be synthesized from an acid component such as polycarboxylic acid and a glycol component or a polyol component. Examples of acid components include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, trimellitic acid, and the like, and glycol components include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, and 1,6-hexane glycol. , 3-methyl-1,5-pentanediol, 3,3′-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol and the like. Examples of the polyol component include glycerin, trimethylolpropane, pentaerythritol and the like. Other examples include polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly (β-methyl-γ-valerolactone), and polyvalerolactone.

  Among the polyester polyols synthesized above, it is preferable to use a bifunctional or trifunctional polyester polyol from the viewpoint of obtaining good adhesiveness.

  Further, the number average molecular weight of the polyester polyol is not particularly limited, and those having a low molecular weight to a high molecular weight can be used. Among them, although there is a balance with the functional number of the polyesterol polyol, a polyester polyol having a number average molecular weight of 1,000 to 5,000 is preferable, and a polyester polyol having a number average molecular weight of 1,000 to 3,500 is more preferable. . By using the one having a number average molecular weight of 1,000 or more, the reactivity does not become too high and gelation becomes difficult. Moreover, by using the one having a number average molecular weight of 5,000 or less, the reactivity is not lowered, and further, the cohesive force of the urethane-based pressure-sensitive adhesive resin (A2) itself is hardly reduced.

  In addition, if necessary, some glycols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, pentaerythritol, ethylenediamine, N-aminoethylethanolamine, Polyhydric amines such as isophoronediamine and xylylenediamine can be used in combination.

(Polyether polyol)
It does not specifically limit as polyether polyol used for manufacture of urethane type adhesive resin (A2), For example, the polyalkylene glycol (molecular weight about 100-5500) addition product of a polyhydric alcohol is used preferably. Examples of the polyhydric alcohol include aliphatic dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butylene glycol (tetramethylene glycol) and neopentane glycol; glycerin, trioxyisobutane and 1,2,3-butane. Triol, 1,2,3-pentanetriol, 2-methyl-1,2,3-propanetriol, 2-methyl-2,3,4-butanetriol, 2-ethyl-1,2,3-butanetriol, 2,3,4-pentanetriol, 2,3,4-hexanetriol, 4-propyl-3,4,5-heptanetriol, 2,4-dimethyl-2,3,4-pentanetriol, pentamethylglycerin, Pentaglycerin, 1,2,4-butanetriol, 1,2,4-pentanetriol, Trihydric alcohols such as limethylolpropane; erythritol, pentaerythritol, 1,2,3,4-pentanetetrol, 2,3,4,5-hexanetetrol, 1,2,3,5-pentanetetrol , Tetrahydric alcohols such as 1,3,4,5-hexanetetrol; pentavalent alcohols such as adnit, arabit and xylit; hexavalent alcohols such as sorbit, mannitol and exit. Among these, divalent to tetravalent alcohols are preferable, and propylene glycol, 1,4-butylene glycol, and glycerin are more preferably used.

  Among the above-mentioned polyether polyols, it is preferable from the viewpoint of reactivity control to use a bifunctional or trifunctional polyether polyol.

  Further, the number average molecular weight of the polyether polyol is not particularly limited, and those having a low molecular weight to a high molecular weight can be used. Among them, although there is a balance with the functional number of the polyether polyol, a polyether polyol having a number average molecular weight of 1,000 to 5,000 is preferable, and a polyether polyol having a number average molecular weight of 1,000 to 3,500 is preferable. More preferred. By using the one having a number average molecular weight of 1,000 or more, the reactivity does not become too high and gelation becomes difficult. Moreover, by using the one having a number average molecular weight of 5,000 or less, the reactivity is not lowered, and further, the cohesive force of the urethane-based pressure-sensitive adhesive resin (A2) itself is hardly reduced.

(Isocyanate compounds)
It does not specifically limit as an isocyanate type compound used for manufacture of urethane type adhesive resin (A2), For example, well-known aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, alicyclic polyisocyanate, etc. are mentioned. Can be mentioned. Aromatic polyisocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate Isocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanatebenzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 "- Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and pentamethylene diisocyanate. Nate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, etc. As aromatic aliphatic polyisocyanate Is ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diene Examples include isocyanate, 1,3-tetramethylxylylene diisocyanate, etc. Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentanediiso. Cyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 1,4-bis (Isocyanatemethyl) cyclohexane, 1,4-bis (isocyanatemethyl) cyclohexane and the like can be mentioned.

  Among the above-mentioned isocyanate compounds, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate) and the like are preferable.

(Manufacture of urethane adhesive resin (A2))
As described above, the urethane pressure-sensitive adhesive resin (A2) according to the present invention can be produced by reacting a polyester polyol and / or a polyether polyol with an isocyanate compound. Preferably, the polyester polyol and the polyether polyol are produced by reacting an isocyanate compound.

  When the polyester polyol and the polyether polyol are used in combination as the polyol, the molar ratio of the polyester polyol to the polyether polyol (polyester polyol: polyether polyol) is preferably 10:90 to 90:10, and 30:70 More preferably, it is ˜70: 30.

  The amount of the isocyanate compound used is preferably 1 to 30 parts by weight with respect to 100 parts by weight of the total amount of polyols used (when the polyester polyol and polyether polyol are used in combination). More preferably, it is -20 weight part. If it is such a range, an isocyanate type compound can react substantially completely, and a hydroxyl group can remain in the molecule | numerator of urethane type adhesive resin. This hydroxyl group forms a network with an isocyanate-based crosslinking agent described later, and durability can be improved.

  A known catalyst is used when producing the urethane-based pressure-sensitive adhesive resin (A2). Examples thereof include organometallic compounds such as tertiary amine compounds, tin compounds, and non-tin compounds.

  Examples of the tertiary amine compound include triethylamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU), and the like.

  Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, Examples include triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate.

  Examples of non-tin compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate and butoxytitanium trichloride, lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate and lead naphthenate, 2- Examples include iron series such as iron ethylhexanoate and iron acetylacetonate, cobalt series such as cobalt benzoate and cobalt 2-ethylhexanoate, zinc series such as zinc naphthenate and zinc 2-ethylhexanoate, and zirconium naphthenate. It is done.

  These catalysts may be used independently and may use 2 or more types together. Moreover, when using together polyester polyol and polyether polyol as a polyol, it is preferable to use 2 or more types together from a single catalyst by the difference in the reactivity. The combination of the two or more types of catalysts is not particularly limited, and tertiary amine / organic metal type, tin type / non-tin type, non-tin type / non-tin type, etc. are used, preferably non-tin type / It is a non-tin type, and a combination of lead 2-ethylhexanoate and lead naphthenate is more preferable. The compounding ratio is 2 parts by weight of lead 2-ethylhexanoate / lead naphthenate <1, preferably 0.2 to 0.8.

  It is preferable that the usage-amount of a catalyst is 0.01-1.0 weight part with respect to 100 weight part of total amounts of the polyol and isocyanate type compound to be used.

  It does not specifically limit as a solvent at the time of manufacturing urethane type adhesive resin (A2), A well-known thing is used. For example, methyl ethyl ketone, ethyl acetate, toluene, xylene, acetone and the like can be mentioned. Further, it is not necessary to add a solvent depending on the type of polyol or isocyanate compound used.

  As reaction temperature for manufacturing urethane type adhesive resin (A2), it is preferable that it is 100 degrees C or less, and it is more preferable that it is 85 to 95 degreeC. If it is such a temperature range, it will become easy to control reaction rate and a crosslinked structure, and it will become easy to obtain urethane type adhesive resin (A2) which has a predetermined molecular weight and chemical structure.

  Moreover, it does not specifically limit as reaction time, For example, it is preferable to make it react until a residual isocyanate group disappears with an infrared spectrophotometer (IR).

[Polyester adhesive resin (A3)]
The polyester-based pressure-sensitive adhesive resin (A3) according to the present invention can be produced by an esterification reaction using a polyol component and a carboxylic acid component.

  It does not specifically limit as a polyol component used for manufacture of a polyester-type adhesive resin (A3), A well-known thing is used. For example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, Linear aliphatic diols such as 1,10-decanediol; neopentyl glycol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl- 1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl- 1,5-pentanediol, 1,3,5-trimethyl-1,3-pentanediol, 2-methyl-1,6-hexanediol How and aliphatic diol having a hydrocarbon group side chains and the like, may be used one or more of them. Among these, from the point that the initial adhesiveness, mechanical strength, and heat resistance can be balanced, a straight chain aliphatic diol having 2 to 6 carbon atoms, particularly 1,4-butanediol, 1,6-hexanediol, Ethylene glycol or an aliphatic diol having a hydrocarbon group side chain having 1 to 4 carbon atoms, particularly neopentyl glycol is preferred.

  Moreover, you may contain a small amount of polyether diol and a trihydric or more polyhydric alcohol as needed. As examples of such polyether diols and trihydric or higher polyhydric alcohols, for example, those described in paragraphs “0039” to “0040” of JP-A-2007-45913 can be appropriately employed.

  It does not specifically limit as a carboxylic acid component used for manufacture of a polyester-type adhesive resin (A3), A well-known thing is used. For example, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, aromatic dicarboxylic acids such as p-oxybenzoic acid, succinic acid, glutaric acid, adipic acid, azelaic acid Saturated dicarboxylic acids such as aliphatic dicarboxylic acids such as sebacic acid, decanedicarboxylic acid and octadecanedicarboxylic acid; fumaric acid, maleic acid, itaconic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, hexahydrophthalic acid, dimer acids, etc. Unsaturated dicarboxylic acid etc. are mention | raise | lifted and these can use 1 type (s) or 2 or more types. If necessary, a small amount of trivalent or higher carboxylic acid such as trimellitic acid, trimesic acid, pyromellitic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid may be contained. Among these, aromatic dicarboxylic acid, especially terephthalic acid, isophthalic acid, and carbon number of 6 to 12 (including carbon of carboxyl group) from the point that the initial adhesiveness, mechanical strength, and heat resistance can be balanced. Aliphatic dicarboxylic acids, particularly sebacic acid, are preferred.

(Production of polyester adhesive resin (A3))
The amount of the polyol component and the carboxylic acid component used in the production of the polyester-based pressure-sensitive adhesive resin (A3) has a balance with each type, but the polyol component is mainly 1 equivalent or more per equivalent of the carboxylic acid component. It is preferable to use at 1.2 equivalents or more. Moreover, as a minimum, it is preferable to use 2 equivalent of a polyol component per equivalent of the carboxylic acid component.

  Within such a range, the carboxylic acid component in the polyester-based pressure-sensitive adhesive resin (A3) can react almost completely, so that reworkability can be secured and hydroxyl in the polyester-based pressure-sensitive adhesive resin (A3). Since the group can remain, durability can also be improved.

  A known catalyst is used when producing the polyester-based pressure-sensitive adhesive resin (A3). For example, titanium-based catalysts such as tetraisopropyl titanate and tetra-n-butyl titanate, antimony-based compounds such as antimony trioxide, germanium-based catalysts such as germanium oxide, zinc acetate, manganese acetate, and dibutyltin oxide can be used. These 1 type or 2 types or more are used.

  It is preferable that the usage-amount of a catalyst is 0.01-1.0 weight part with respect to 100 weight part of all the copolymerization components (total amount of a polyol and carboxylic acid). If it is such a range, ester reaction can fully advance, reaction time can be shortened, and side reaction becomes difficult to occur.

  It does not specifically limit as a solvent at the time of manufacturing a polyester-type adhesive resin (A3), A well-known thing is used. For example, methyl ethyl ketone, ethyl acetate, toluene, xylene, acetone and the like can be mentioned. In addition, the solvent may not be added depending on the type of polyol or carboxylic acid used, and may be added only for concentration adjustment after the reaction.

  The reaction temperature for producing the polyester-based pressure-sensitive adhesive resin (A3) is usually 100 to 400 ° C, more preferably 120 to 300 ° C, and particularly preferably 150 to 280 ° C.

  When producing the polyester-based pressure-sensitive adhesive resin (A3), it is preferable to gradually reduce the pressure of the reaction system from normal pressure, for example, in a reaction system of 10 to 1000 Pa. The decompression may be performed in several stages over time.

  In addition, the reaction time is not particularly limited, and may be appropriately set depending on the types of polyols and carboxylic acids used according to a conventional method, conditions for reduced pressure, and the like. For example, it is preferably 0.5 to 20 hours, and more preferably 1 to 10 hours.

<Silicone alkoxy oligomer (B)>
The silicone alkoxy oligomer is a relatively low molecular weight silicone resin having a main chain of polyorganosiloxane and a molecular terminal or side chain blocked with an alkoxysilyl group.

  The epoxy equivalent in the silicone alkoxy oligomer (B) is 100 to 2000 g / mol, preferably 200 to 1500 g / mol, and more preferably 250 to 1200 g / mol. In the present invention, when the acrylic pressure-sensitive adhesive resin (A1) is used as the pressure-sensitive adhesive resin (A), if the epoxy equivalent is less than 100 g / mol, durability can be improved, but reworkability cannot be improved. . On the other hand, it has been found that when the epoxy equivalent is more than 2000 g / mol, the reworkability of the pressure-sensitive adhesive composition can be improved, but the durability is adversely affected. The silicone alkoxy oligomer (B) used in combination with the silicone alkoxy oligomer (B) using the urethane pressure sensitive adhesive resin (A2) or the polyester pressure sensitive adhesive resin (A3) as the pressure sensitive adhesive resin (A) is an epoxy. The equivalent is not particularly limited, and those in the above range are also preferably employed.

  The silicone alkoxy oligomer (B) according to the present invention preferably has one or more selected from methyl, phenyl, epoxy, mercapto, amino, methacryl and acryl as the organic substituent, and one or more selected from methyl and epoxy. It is more preferable to have. Moreover, what has methoxy and / or ethoxy as an alkoxyl group is preferable.

  In addition, content of the alkoxyl group in the silicone alkoxy oligomer (B) based on this invention is 5 to 60 weight%, Preferably it is 10 to 55 weight%, More preferably, it is 15 to 50 weight%. In the present invention, when the acrylic pressure-sensitive adhesive resin (A1) is used as the pressure-sensitive adhesive resin (A), the reworkability of the pressure-sensitive adhesive composition can be improved when the alkoxyl group content is less than 5% by weight. However, it has been found that if the content of the alkoxyl group exceeds 60% by weight, the durability can be improved but the reworkability cannot be improved. The silicone alkoxy oligomer (B) used in combination with the silicone alkoxy oligomer (B) using the urethane pressure sensitive adhesive resin (A2) or the polyester pressure sensitive adhesive resin (A3) as the pressure sensitive adhesive resin (A) is alkoxyl. It does not specifically limit about group content, The thing of the said range is employ | adopted preferably.

  In the present invention, the silicone alkoxy oligomer (B) can be used as a synthetic product or a commercially available product as long as the epoxy equivalent and the alkoxyl group content satisfy the above ranges.

  In the present invention, a silicone alkoxy oligomer (B) is produced by hydrolyzing a silane coupling agent having both an epoxy group and an alkoxyl group and an alkoxysilane in the presence of an acid and the like, and further causing a condensation reaction. It is preferable.

  It does not specifically limit as a silane coupling agent which has both the epoxy group used for manufacture of a silicone alkoxy oligomer (B), and an alkoxyl group, For example, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 -Glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, etc. are mentioned.

  The alkoxysilane used for the production of the silicone alkoxy oligomer (B) is not particularly limited. For example, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxy. Silane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis (trimethoxysilyl) hexane, and tri Examples include fluoropropyltrimethoxysilane.

  In producing the silicone alkoxy oligomer (B), in order for the epoxy equivalent and the alkoxyl group content to satisfy the above-mentioned ranges, a combination of a silane coupling agent having both an epoxy group and an alkoxyl group and an alkoxysilane This can be achieved by appropriately adjusting the ratio (for example, molar ratio) and the like.

  Moreover, when manufacturing a silicone alkoxy oligomer (B), well-known solvents, such as methanol or ethanol, can be employ | adopted suitably, for example.

  It does not specifically limit as reaction temperature for manufacturing a silicone alkoxy oligomer (B), It can adjust with the raw material to be used, for example, can be performed under room temperature. In addition, the reaction time can be adjusted depending on the raw material used, and can be performed, for example, in 0.5 to 5 hours.

  It does not specifically limit as a commercial item of the silicone alkoxy oligomer (B) used for this invention, For example, X-41-1053 (epoxy equivalent 830 g / mol; alkoxyl group content 50 weight% by Shin-Etsu Chemical Co., Ltd.) ), X-41-1059A (epoxy equivalent 350 g / mol; alkoxyl group content 42% by weight), X-41-1056 (epoxy equivalent 280 g / mol; alkoxyl group content 27% by weight), and the like.

  The number average molecular weight of the silicone alkoxy oligomer (B) according to the present invention is preferably 200 to 50000, more preferably 300 to 10000, more preferably 500 to 500, from the viewpoint of achieving both durability and reworkability. It is particularly preferably 5000. In addition, in this specification, a number average molecular weight can be measured by the method shown in an Example.

  In the pressure-sensitive adhesive composition of the present invention, the addition amount of the silicone alkoxy oligomer (B) is 0.1 to 20 parts by weight, preferably 0.3 with respect to 100 parts by weight of the pressure-sensitive adhesive resin (A) described above. -10 parts by weight, more preferably 0.5-5 parts by weight. If the amount added is less than 0.1 parts by weight, reworkability cannot be ensured. On the other hand, when the addition amount is more than 20 parts by weight, when the pressure-sensitive adhesive composition is used for a polarizing plate or the like, the humidification durability is deteriorated, so that the degree of polarization is lowered.

<Crosslinking agent (C)>
In addition to the acrylic adhesive resin (A1) and the silicone alkoxy oligomer (B) described above, the pressure-sensitive adhesive composition of the present invention preferably further contains a crosslinking agent (C) from the viewpoint of improving durability.

  In this invention, it is preferable that the addition amount in the case of containing a crosslinking agent (C) is 0.001-30 weight part with respect to 100 weight part of adhesive resin (A), 0.01-20 weight Part is more preferable, and 0.05 to 10 parts by weight is particularly preferable. If it is such a range, durability can be improved.

  The crosslinking agent (C) used in the present invention is not particularly limited, and may be an isocyanate compound, a peroxide, a carbodiimide compound, a titanium coupling agent, a zirconium compound, or a metal aluminum chelate. Among these, from the viewpoint of improving durability, at least one selected from an isocyanate compound and a peroxide is preferable.

[Isocyanate compounds]
The isocyanate compound that is suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include triallyl isocyanate, dimer acid diisocyanate, 2,4-tolylene diisocyanate (2,4-TDI), and 2,6-tril. Range isocyanate (2,6-TDI), 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI), 1,4-phenylene diisocyanate, xylylene Aromatic diisocyanates such as diisocyanate (XDI), tetramethylxylidene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI); hexamethylene diisocyanate (HDI), trimethylhexene Aliphatic diisocyanates such as samethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate methyl (NBDI); transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI), H12 -Cycloaliphatic diisocyanates such as MDI (hydrogenated MDI); carbodiimide-modified diisocyanates of the above diisocyanates; or these isocyanurate-modified diisocyanates. These can be used alone or in combination. Moreover, you may use together with the peroxide mentioned later.

  Adducts of the above isocyanate compounds and polyol compounds such as trimethylolpropane, biurets and isocyanurates of these isocyanate compounds can also be suitably used.

  Moreover, an isocyanate type compound may be synthesize | combined and a commercial item may be used. Examples of commercially available components (D) include Coronate (registered trademark) L, Coronate (registered trademark) HL, Coronate (registered trademark) HX, Coronate (registered trademark) 2030, Coronate (registered trademark) 2031 (and above, Japan). Polyurethane Industry Co., Ltd.), Takenate (registered trademark) D-102, Takenate (registered trademark) D-110N, Takenate (registered trademark) D-200, Takenate (registered trademark) D-202 (above, manufactured by Mitsui Chemicals, Inc.) ), Duranate (registered trademark) 24A-100, Duranate (registered trademark) TPA-100, Duranate (registered trademark) TKA-100, Duranate (registered trademark) P301-75E, Duranate (registered trademark) E402-90T, Duranate (registered) Trademark) E405-80T, Duranate (registered trademark) TSE- 00, Duranate (registered trademark) D-101, Duranate (registered trademark) D-201 (above, manufactured by Asahi Kasei Chemicals Corporation), Sumijoule (registered trademark) N-75, N-3200, N-3300 (above, residence) Bayer Urethane Co., Ltd.). Among these, Coronate (registered trademark) L, Coronate (registered trademark) HL, Coronate (registered trademark) HX, Takenate (registered trademark) D110N, Duranate (registered trademark) 24A-100, Duranate (registered trademark) TPA-100 Coronate (registered trademark) L, Coronate (registered trademark) HX, and Duranate (registered trademark) 24A-100 are more preferable.

  Moreover, in this invention, when using an isocyanate type compound as a crosslinking agent (C), it is preferable that the adhesive resin (A) used for this invention mentioned above contains a hydroxyl group. This is because the hydroxyl group and the isocyanate compound form a network, and the durability of the pressure-sensitive adhesive composition of the present invention can be improved.

[Peroxide]
As the peroxide suitably used as the crosslinking agent (C), any peroxide can be used as long as it can generate a radical by heating to achieve crosslinking of the pressure-sensitive adhesive composition, but considering workability and stability. It is preferable to use a peroxide having a one-minute half-life temperature of preferably 80 ° C to 160 ° C, more preferably 90 ° C to 140 ° C. The half-life of the peroxide is an index representing the decomposition rate of the peroxide, and is the time for which the amount of peroxide decomposition is halved. The decomposition temperature for obtaining the half-life at an arbitrary time In addition, the half-life time at an arbitrary temperature is described in the manufacturer catalog and the like, for example, in the organic peroxide catalog 9th edition (May 2003) published by Nippon Oil & Fats Co., Ltd.

  Examples of such peroxides include bis (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature 90.6 ° C), bis (4-t-butylcyclohexyl) peroxydicarbonate (92.1 ° C). ), Bis-sec-butyl peroxydicarbonate (92.4 ° C.), t-butyl peroxyneodecanoate (103.5 ° C.), t-hexyl peroxypivalate, (109.1 ° C.) ), T-butyl peroxypivalate (110.3 ° C.), dilauroyl peroxide (116.4 ° C.), bis-n-octanoyl peroxide (117.4 ° C.), 1,1,3 , 3-tetramethylbutylperoxy-2-ethylhexanoate (124.3 ° C.), bis (4-methylbenzoyl) peroxide (128.2 ° C.), dibenzoy Peroxide (130.0 ° C.) and t-butyl peroxybutyrate (136.1 ° C.), and the like, and bis (4-t-butylcyclohexyl) peroxydicarbonate and dilauroyl parper having excellent crosslinking reaction efficiency. Oxides and dibenzoyl peroxide are preferably used. In particular, bis (4-t-butylcyclohexyl) peroxydicarbonate is preferred from the viewpoint of the decomposition temperature. One or more of these can be used. Moreover, you may use together with the above-mentioned isocyanate type compound.

[Carbodiimide compound]
The carbodiimide compound suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include those described in paragraphs “0039” to “0046” of JP2012-246444 or those appropriately modified. It is done.

[Titanium coupling agent]
The titanium coupling agent suitably used as the crosslinking agent (C) is not particularly limited. For example, the titanium coupling agent is not particularly limited. For example, those described in paragraph “0072” of JP-A-2014-085616 or those appropriately selected The modified one is mentioned.

[Zirconium compound]
The zirconium compound suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include those described in paragraph “0073” of JP-A-2014-085616 or those appropriately modified.

[Metal aluminum chelate]
The metal aluminum chelate suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include those described in paragraph “0058” of JP 2012-229373 A or those appropriately modified.

<Silane coupling agent (D)>
The pressure-sensitive adhesive composition of the present invention can further contain a silane coupling agent (D) from the viewpoint of improving durability.

  The silane coupling agent (D) refers to one having no siloxane bond and having two or more different reactive groups in the molecule, and should be distinguished from the silicone alkoxy oligomer (B) according to the present invention. It is.

  The silane coupling agent (D) used in the present invention is not particularly limited. For example, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane. N-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, Vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, γ-glycidoxy Propyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxy Silane, γ-acryloxypropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- ( Aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ- Me Mercaptopropyltrimethoxysilane, .gamma.-mercaptopropyl methyl dimethoxy silane, bis - (3- [triethoxysilyl] propyl) tetrasulfide, .gamma. isocyanatepropyltriethoxysilane and the like. Further, a silane coupling agent having a functional group such as an epoxy group (glycidoxy group), an amino group, a mercapto group, or a (meth) acryloyl group, and a functional group having reactivity with these functional groups. A compound having a hydrolyzable silyl group obtained by reacting an agent, another coupling agent, polyisocyanate and the like with each functional group in an arbitrary ratio can also be used.

  The silane coupling agent may be synthesized or a commercially available product may be used. Examples of commercially available silane coupling agents include KBM-303, KBM-403, KBE-402, KBE-403, KBE-502, KBE-503, KBM-5103, KBM-573, KBM-802, KBM- 803, KBE-846, KBE-9007 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

  The said silane coupling agent may be used independently and may be used in combination of 2 or more type.

  In the present invention, the amount added when the silane coupling agent (D) is contained is more preferably 0.0001 to 10 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin (A), and 0.001 It is more preferably ˜5 parts by weight, and particularly preferably 0.01 to 3 parts by weight. If it is such a range, durability can be improved.

{Usage}
The above-mentioned pressure-sensitive adhesive composition of the present invention is suitable for various uses. For example, it is preferably used for an optical member such as an optical film. In particular, it is preferably used for optical films that have become thin and brittle recently. As such an optical film, a polarizing plate, a retardation plate for preventing coloring, an optical compensation film such as a viewing angle expansion film for improving the viewing angle of a liquid crystal display, a brightness enhancement film for increasing the contrast of the display, Furthermore, what laminated | stacked these is mentioned.

  In the present invention, the form of the pressure-sensitive adhesive layer formed from the above-mentioned pressure-sensitive adhesive composition, the form of the optical member in which the pressure-sensitive adhesive layer is formed on an optical film, and the like, the optical member is a pressure-sensitive adhesive optical film or pressure-sensitive adhesive A form that is a type polarizing plate, a form in which the optical member is applied to a liquid crystal display device, an organic EL display device, a plasma display (image display device such as PDP), and the like can be provided.

<Adhesive layer>
The present invention provides a pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition of the present invention.

  In this invention, an adhesive layer can be formed by apply | coating the adhesive composition of this invention to a base material etc., and drying and removing a solvent etc. In applying the pressure-sensitive adhesive composition, one or more solvents may be added as appropriate.

  In addition, the separator mentioned later can be used as a base material of an adhesive layer.

  The application method is not particularly limited, and various known methods are used. For example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, extrusion coat method by die coater, etc. A method is mentioned.

  As a method for drying the solvent present in the pressure-sensitive adhesive composition, an appropriate method can be adopted depending on the purpose. Preferably, a method of heating and drying the coating film is used. The heat drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained.

  The drying time can be set as appropriate. The time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

  The thickness (dry film thickness) of the pressure-sensitive adhesive layer of the present invention is not particularly limited and can be appropriately set depending on the intended use. For example, when used for an optical film, the thickness is preferably 1 to 100 μm, more preferably 5 to 50 μm, and particularly preferably 10 to 30 μm.

  Moreover, when the adhesive layer which concerns on this invention is exposed, an adhesive layer can be protected with the sheet | seat (separator) etc. which were peel-processed until it was used practically.

  Examples of the constituent material of the separator include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Although a thin leaf body etc. can be mentioned, a plastic film is used suitably from the point which is excellent in surface smoothness.

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

  For separators, silicone, fluorine, long-chain alkyl or fatty acid amide release agents, release treatment with silica powder and antifouling treatment, coating type, kneading type, vapor deposition, as required An antistatic treatment such as a mold can be performed. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.

<Adhesive optical film>
The present invention also provides an optical member in which the pressure-sensitive adhesive layer of the present invention is formed on at least one side of the optical film. Here, an example of the optical member is an adhesive optical film. The “adhesive optical film” is an optical film having the adhesive layer of the present invention. Moreover, since the optical film includes the form of a polarizing plate, the adhesive optical film according to the present invention includes the form of an adhesive polarizing plate.

  In the present invention, the above-mentioned pressure-sensitive adhesive composition may be used by directly applying to one side or both sides of an optical film to form a pressure-sensitive adhesive layer. It may be used by forming and transferring it to one or both sides of the optical film. Further, before the transfer, the surface of the optical film may be subjected to a ground treatment such as corona treatment, plasma treatment or formation of an easy adhesion layer, or an antistatic layer, depending on the material. Moreover, you may perform an easily bonding process also on the surface of an adhesive layer. From the viewpoint of firmly bonding the optical film and the pressure-sensitive adhesive layer, it is preferable to have an easy-adhesion layer between the optical film and the pressure-sensitive adhesive layer for optical films of the present invention.

(Easily adhesive layer)
In the present invention, the material for forming the easy-adhesion layer is a material that exhibits good adhesion to both the pressure-sensitive adhesive layer and the optical film (for example, a transparent protective film for a polarizing plate) and forms a film having excellent cohesive strength. preferable. For example, various polymers, metal oxide sols, silica sols and the like are used, and polymers are particularly preferably used.

  Examples of the polymers suitably used in the present invention include oxazoline group-containing polymers, polyurethane resins, polyester resins, and polymers containing amino groups in the molecule. Among these, an oxazoline group-containing polymer is more preferably used.

  As such an oxazoline group-containing polymer, a general commercial product is used, and examples thereof include, but are not limited to, EPOCROSS series (for example, EPOCROSS WS700) manufactured by Nippon Shokubai Co., Ltd. In addition, as for polyurethane resins, polyester resins, polymers containing amino groups in the molecule, those disclosed in paragraphs “0107” to “0113” of JP2011-105918A can be appropriately employed. .

  In the present invention, on the optical film, a primer for forming an easy adhesion layer may be applied and dried using a coating method such as a coating method, a dipping method, or a spray method to form an easy adhesion layer. it can.

  As a thickness (dry film thickness) of an easily bonding layer, it is about 10-5000 nm, Preferably it is 50-500 nm. If it is such a range, it has the property as a bulk, and it can also maintain an optical characteristic, showing sufficient intensity | strength and sufficient adhesiveness.

  The optical film used for the pressure-sensitive adhesive optical film of the present invention is not particularly limited, and examples thereof include those used for forming an image display device such as a liquid crystal display device, but the type is not particularly limited. For example, a polarizing plate, a phase difference plate, an optical compensation film, a brightness enhancement film, and those in which these are laminated can be used.

  Below, the case where the optical film which concerns on this invention is a polarizing plate is demonstrated as an example.

(Polarizer)
In the present invention, a polarizing plate suitable as an optical film is produced by pasting a protective film and a polarizer together with an adhesive by using a conventionally known method and curing by heat drying or ultraviolet rays, an electron beam, or the like. obtain. The applied adhesive exhibits adhesiveness by drying or curing with ultraviolet rays, electron beams or the like, and constitutes an adhesive layer.

  There is no restriction | limiting in particular as a polarizer, A conventionally well-known thing can be used. For example, dichroic materials such as iodine and dichroic dyes are adsorbed on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. And polyene-based oriented films such as a uniaxially stretched product, a polyvinyl alcohol dehydrated product and a polyvinyl chloride dehydrochlorinated product.

  Among these, a polarizer produced by dyeing a polyvinyl alcohol film having an average polymerization degree of 2000 to 2800 and a saponification degree of 90 to 100 mol% with iodine and uniaxially stretching 3 to 8 times is particularly preferable. More specifically, such a polarizer is obtained by, for example, immersing and stretching a polyvinyl alcohol film by immersing it in an aqueous solution of iodine.

  As an aqueous solution of iodine, for example, it is preferably immersed in an aqueous solution containing 0.1 to 1.0% by weight of iodine and / or potassium iodide. Moreover, you may immerse in aqueous solutions, such as 50-70 degreeC boric acid and potassium iodide, as needed, and you may immerse in 25-35 degreeC water for washing | cleaning and dyeing | staining unevenness prevention. Stretching may be performed after dyeing with iodine, may be stretched while dyeing, or may be dyed with iodine after stretching. After dyeing and stretching, it may be washed with water and dried at 35 to 55 ° C. for about 1 to 10 minutes. A wide variety of such polarizers are commercially available.

  The thickness of the polarizer is not particularly limited, but is generally 5 to 80 μm.

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

  A transparent protective film is bonded to one side of the polarizer with an adhesive. On the other side, a (meth) acrylic, urethane-based, acrylic-urethane-based, epoxy-based transparent protective film or protective layer Further, a silicone-based thermosetting resin or an ultraviolet curable resin can be used.

  Although the thickness of a polarizing plate is not specifically limited, Generally, it is 20-200 micrometers. In the present invention, from the viewpoint of thinning, it is preferably 100 μm or less, more preferably 75 μm or less, and particularly preferably 50 μm or less. Such a thin polarizing plate is preferable from the viewpoint of more remarkably expressing the effect of the pressure-sensitive adhesive composition of the present invention.

  The manufacturing method of a polarizing plate is not specifically limited, For example, after apply | coating an adhesive agent, it can carry out by bonding together a polarizer and a protective film with a roll laminator etc. After bonding, a curing step may be performed as appropriate by drying or ultraviolet rays, an electron beam or the like. Moreover, when apply | coating an adhesive agent, you may apply | coat to any of a protective film and a polarizer, and may apply | coat to both. The adhesive is preferably applied so that the thickness of the adhesive layer after drying is 10 to 300 nm. Moreover, it does not specifically limit as an adhesive agent, According to the material of a polarizer, it can employ | adopt suitably from well-known things. For example, when a polyvinyl alcohol film is used as the polarizer, an acrylic, epoxy, or acryl-epoxy system can be used as the polyvinyl alcohol adhesive or the ultraviolet curable adhesive. The thickness of the adhesive layer is 10 to 200 nm for the polyvinyl alcohol-based adhesive and 0.2 to 10 μm for the ultraviolet curable adhesive because it can obtain a uniform in-plane thickness and sufficient adhesive strength. It is preferable.

  In the present invention, an adhesive polarizing plate in which an adhesive layer is formed can also be provided. In addition, since it is the same as that of the case of the adhesive optical film mentioned above about the structure, manufacture, etc. of an adhesive polarizing plate, description is abbreviate | omitted here.

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

  The image display device is not particularly limited, and examples thereof include a liquid crystal display device, an organic EL display device, a plasma display (PDP), and the like. In addition, a thin image display device is preferably applied from the viewpoint of more remarkably expressing the effect of the pressure-sensitive adhesive composition of the present invention.

  The present invention will be described in further detail with reference to the following examples and comparative examples, but the technical scope of the present invention is not limited only to the following examples.

  Further, in the following operations, unless otherwise specified, measurements such as operations and physical properties are performed under conditions of 23 ° C. and 55% RH (relative humidity).

[Preparation of Production Example 1 Adhesive Resin (A1-1)]
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and cooler, 99 parts by weight of n-butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) ) 1 part by weight, and 2,5′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) 0.15 part by weight as a polymerization initiator were charged together with 100 parts by weight of ethyl acetate and gently stirred. Nitrogen gas was introduced. After substituting with nitrogen gas, the liquid temperature in the flask was controlled at around 55 ° C. and a polymerization reaction was carried out for 5 hours to prepare an acrylic pressure-sensitive adhesive resin (A1-1) solution having a solid content of 15% (w / w). .

  The obtained acrylic pressure-sensitive adhesive resin (A1-1) had a weight average molecular weight of 2.1 million and a viscosity of 8000 mPa · s.

[Preparation of Production Examples 2-4 Adhesive Resin (A1-2), (A1-3), (A1-4)]
Except having changed the kind or ratio of the monomer which forms acrylic adhesive resin as shown in Table 1, operation similar to manufacture example 1 is performed, and solid content is 15% (w / w) in all. Adhesive resin (A1-2) to (A1-4) solutions were prepared.

  All of the obtained pressure-sensitive adhesive resins (A1-2) to (A1-4) had a weight average molecular weight of 2.1 million and a viscosity of 8000 mPa · s.

[Preparation of Production Example 5 Adhesive Resin (A2)]
51. Polyester polyol P-1010 (bifunctional polyester polyol, OH number 112, molecular weight 1,000, manufactured by Kuraray Co., Ltd.) in a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel 9 parts by weight, Adeka polyether G-1500 (trifunctional polyether polyol, trifunctional, OH number 109, number average molecular weight 1,500, manufactured by ADEKA Corp.) 32.2 parts by weight, isophorone diisocyanate (manufactured by Sumitomo Bayer Co., Ltd.) ) 15.9 parts by weight, 66.7 parts by weight of toluene, 0.03 part by weight of iron 2-ethylhexanoate and 0.04 part by weight of lead naphthenate as a catalyst, and gradually heated to 90 ° C. 4 Time reaction was performed. Using infrared spectrophotometer (IR), check the residual isocyanate group near 2260 cm ^-1, the 2260 cm ^-1 to terminate the reaction when I disappeared peak around cooling, solids 60% (w / w ), A colorless and transparent urethane-based pressure-sensitive adhesive resin (A2) solution having a viscosity of 3,000 mPa · s was prepared.

  The resulting urethane-based pressure-sensitive adhesive resin (A2) had a number average molecular weight of 15,000, a weight average molecular weight of 50,000, and an acid value of 0.5 KOH mg / g.

[Preparation of Production Example 6 Adhesive Resin (A3)]
In a four-necked separable flask equipped with a thermometer, stirrer, distillation tube, and condenser, ethylene glycol 11.7 parts by weight, neopentyl glycol 18.6 parts by weight, isophthalic acid 11.8 parts by weight, sebacic acid 57. 9 parts by weight and 0.15 part by weight of tetra-n-butyl titanate as a catalyst were added, heated at 150 to 270 ° C. for 150 minutes to carry out an esterification reaction, and then the pressure of the reaction system was gradually reduced and 30 minutes later The reaction was carried out for 180 minutes while maintaining the pressure at 133 Pa. Dilution with ethyl acetate gave a polyester-based pressure-sensitive adhesive resin (A3) solution of pressure-sensitive adhesive resin (A3) having a solid content of 60% (w / w) and a viscosity of 3,000 mPa · s.

  The resulting polyester-based pressure-sensitive adhesive resin (A3) had a number average molecular weight of 13,000, a weight average molecular weight of 38,000, and an acid value of 0.3 KOH mg / g.

[Preparation of Production Example 7 Silicone Alkoxy Oligomer (B1)]
440 parts by weight (2 moles) of 3-glycidoxypropylmethyldimethoxysilane, 272 parts by weight of methyltrimethoxysilane (2 moles), 70 parts by weight of methanol, and 26.8 parts by weight of acetic acid were equipped with a thermometer and a water-cooled condenser. In a 1 L separable flask, the mixture was stirred at room temperature. Into this, 49.5 parts by weight (2.8 mol) of ion-exchanged water was added and stirred at room temperature for 2 hours. Thereafter, the solvent is distilled off at normal pressure until the temperature of the reaction solution reaches 110 ° C., whereby a colorless transparent silicone alkoxy oligomer (B1) having a solid content of 98.0% (w / w) and a viscosity of 250 mPa · s is obtained. A liquid was obtained.

  The resulting silicone alkoxy oligomer (B1) had a polystyrene-equivalent number average molecular weight of 15000, an epoxy equivalent of 350 g / mol, and an alkoxyl group content of 17% by weight.

[Production Example 8 Preparation of Silicone Alkoxy Oligomer (B2)]
3-glycidoxypropylmethyldimethoxysilane 62.8 parts by weight (0.285 moles), methyltrimethoxysilane 505.2 parts by weight (3.715 moles), methanol 270 parts by weight, and acetic acid 26.8 parts by weight. Into a 1 L separable flask equipped with a thermometer and a water-cooled condenser, the mixture was stirred at room temperature. Into this, 49.5 parts by weight (2.8 mol) of ion-exchanged water was added. Stir at room temperature for 2 hours. Thereafter, the solvent is distilled off at normal pressure until the reaction solution temperature reaches 110 ° C., whereby a colorless transparent silicone alkoxy oligomer (B2) liquid having a solid content of 98.5% (w / w) and a viscosity of 300 mPa · s is obtained. Got.

  The resulting silicone alkoxy oligomer (B2) had a polystyrene-equivalent number average molecular weight of 1000, an epoxy equivalent of 3200 g / mol, and an alkoxyl group content of 42% by weight.

[Production Example 9 Preparation of Silicone Alkoxy Oligomer (B3)]
3-glycidoxypropylmethyldimethoxysilane 817.3 parts by weight (3.715 moles), methyltrimethoxysilane 36 parts by weight (0.285 moles), methanol 270 parts by weight, and acetic acid 26.8 parts by weight The flask was placed in a 1 L separable flask equipped with a meter and a water-cooled condenser and stirred at room temperature. Into this, 49.5 parts by weight (2.8 mol) of ion-exchanged water was added and stirred at room temperature for 2 hours. Thereafter, the solvent is distilled off at normal pressure until the reaction solution temperature reaches 110 ° C., thereby obtaining a colorless and transparent silicone alkoxy oligomer (B3) liquid having a solid content of 98.2% (w / w) and a viscosity of 270 mPa · s. Obtained.

  The obtained silicone alkoxy oligomer (B3) had a polystyrene-equivalent number average molecular weight of 1000, an epoxy equivalent of 230 g / mol, and an alkoxyl group content of 2% by weight.

  The weight average molecular weight, number average molecular weight, epoxy equivalent, alkoxyl group content, viscosity and the like in the above production examples were measured by the following methods.

(Measurement of weight average molecular weight (Mw))
It was measured by GPC (gel permeation chromatography).
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation, G7000H _XL + GMH _XL + GMH _XL
・ Column size: 7.8mmφ × 30cm each 90cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8ml / min
・ Injection volume: 100 μl
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
Standard sample: polystyrene (measurement of number average molecular weight (Mn))
It was measured by GPC (gel permeation chromatography).
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: TSKgel, SuperHZM-H / HZ4000 / HZ2000
Column size: 6.0 mmI. D. × 150mm
-Column temperature: 40 ° C
・ Flow rate: 0.6ml / min
・ Injection volume: 20 μl
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
-Standard sample: Polystyrene (Measurement of epoxy equivalent)
The epoxy equivalent was measured according to JIS K7236 (2004) test method.

(Measurement of alkoxyl group content)
The alkoxyl group content was determined by separating and quantifying alkoxyl groups by gas chromatography (Analytical Chemistry 17 (9), 1102-1107, 1968).

(viscosity)
The viscosity was measured with a Brookfield viscometer DVII + Pro (spindle No. 63, rotation speed 12 rpm) after the temperature of the polymer solution in a glass bottle was adjusted to 25 ° C.

<Example 1>
(Preparation of pressure-sensitive adhesive composition)
X-41 manufactured by Shin-Etsu Chemical Co., Ltd. as a silicone alkoxy oligomer (B) with respect to the solid content 100% (w / w) of the adhesive resin (A1-1) solution obtained in Production Example 1 above. -1053 (epoxy equivalent 830 g / mol) 1 part by weight, isocyanate crosslinking agent Takenate D110N (75% by weight ethyl acetate solution of trimethylolpropane adduct of xylylene diisocyanate, number of isocyanate groups in one molecule: 3, made by Mitsui Chemicals, Inc. ) 0.1 part by weight and a silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyl trimethoxysilane) 0.1 part by weight, an acrylic pressure-sensitive adhesive A solution of the composition (solid content 15% (w / w)) was prepared.

(Formation of adhesive layer)
After drying the solution of the acrylic pressure-sensitive adhesive composition obtained above on one side of a 38 μm-thick polyethylene terephthalate (PET) film (MRF38, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) subjected to silicone treatment The pressure-sensitive adhesive layer was applied to a thickness of 20 μm and dried at 100 ° C. for 2 minutes to form a pressure-sensitive adhesive layer.

[Preparation of polarizing plate with adhesive layer]
(Production of thin polarizing plate)
A polyvinyl alcohol film having a thickness of 20 μm was stretched up to 3 times while being dyed in an iodine solution having a concentration of 0.3% by weight at 30 ° C. between rolls having different speed ratios. Thereafter, the total draw ratio was stretched up to 6 times while being immersed in an aqueous solution containing boric acid at 4% by weight at 60 ° C. and 10% by weight potassium iodide for 0.5 minutes. Next, after washing by immersing in an aqueous solution containing potassium iodide at 30 ° C. and 1.5 wt% concentration for 10 seconds, drying was performed at 50 ° C. for 4 minutes to obtain a polarizer. An acrylic film (lactone-modified acrylic resin film) having a thickness of 20 μm was bonded to one surface of the polarizer with a polyvinyl alcohol-based adhesive to produce a single-protection thin polarizing plate having a total thickness of 27 μm.

(Preparation of polarizing plate with adhesive layer)
Corona treatment was performed with a corona discharge of 80 [W · min / m ² ] on the polarizer side of the thin polarizing plate obtained above. Subsequently, the PET film which gave the silicone process in which the adhesive layer obtained above was formed was transcribe | transferred to the said polarizer side, and the polarizing plate with an adhesive layer was produced.

<Examples 2-8 and 10-11>
As shown in Table 2, the type of adhesive resin (A) and its addition amount, the type and addition amount of silicone alkoxy oligomer (B), the types of crosslinking agents (C-1) and (C-2) and their Except that the amount added (or not added), and the type of silane coupling (D) and the amount added (or not added) were changed, the same procedure as in Example 1 was followed for each example. A polarizing plate with an adhesive layer was prepared.

  X-41-1056 and X-41-1059A are manufactured by Shin-Etsu Chemical Co., Ltd., and Parroyl TCP is manufactured by Nippon Oil & Fats Co., Ltd.

<Example 9>
As shown in Table 2, the type of adhesive resin (A) and its addition amount, the type and addition amount of silicone alkoxy oligomer (B), the types of crosslinking agents (C-1) and (C-2) and their A thin polarizing plate was produced in the same manner as in Example 1 except that the amount added (or not added), the type of silane coupling (D) and the amount added (or not added) were changed.

  Next, an undercoat was applied to the polarizer side of the thin polarizing plate obtained above with a wire bar to form an easy adhesion layer (thickness 50 nm). As a primer, a solution containing an oxazoline-based polymer (manufactured by Nippon Shokubai Co., Ltd., trade name “Epocross WS-700”) is diluted with a mixed solution of water and isopropyl alcohol, and the solid content concentration is 0.6% ( What was prepared so that it might become w / w) was used.

  Then, the adhesive layer of the PET film which gave the silicone process in which the adhesive layer obtained above was formed was bonded together to the easily bonding layer side, and the adhesive type polarizing film for Example 8 was produced.

<Comparative Examples 1-20>
As shown in Table 2, the type of adhesive resin (A) and the amount thereof added, the type and amount of silicone alkoxy oligomer (B) added (or not added), the crosslinking agents (C-1) and (C-2) ) And the amount added (or not added), and the type of silane coupling (D) and the amount added (or not added) were changed in the same manner as in Example 1, except that The polarizing plate with the adhesive layer corresponding to a comparative example was produced.

<Evaluation>
The following evaluation was performed with respect to the polarizing plate (sample) with each adhesive layer produced by said Example and comparative example. Each evaluation result is shown in Table 3.

〔durability〕
Each sample was 37 inches in size, and was attached to a non-alkali glass (Corning Corp., Eagle XG) having a thickness of 0.7 mm using a laminator. Subsequently, the sample was autoclaved at 50 ° C. and 0.5 MPa for 15 minutes to completely adhere the sample to the acrylic-free glass.

For samples that have undergone such treatment,
(1) After each treatment at 85 ° C. for 500 hours (heating test),
(2) After treatment for 500 hours in an atmosphere of 60 ° C./95% RH (humidification test),
(3) An environment of 85 ° C. and −40 ° C. is performed for 1 hour each, and this is defined as one cycle, after a total of 300 cycles (heat shock (HS) test),
The appearance between the polarizing plate and the glass was visually evaluated based on the following criteria.
A: No change in appearance such as foaming, peeling, or no floating;
○: Slightly peeled off or foamed at the end, but no problem in practical use;
Δ: There is peeling or foaming at the end, but there is no practical problem unless it is a special use;
X: Remarkably peeled off at the end, causing practical problems.

[Reworkability]
Each sample was cut into a width of 25 mm and a length of 100 mm and attached to a non-alkali glass plate (Corning Corp., Eagle XG) having a thickness of 0.7 mm using a laminator.

  Subsequently, it was autoclaved at 50 ° C. and 5 atm for 15 minutes for complete adhesion (initial). Thereafter, a heat treatment was performed for 48 hours under dry conditions at 50 ° C. (after heating). The adhesive strength of each sample was measured as follows.

  The adhesive strength was determined by using a tensile tester (Orientec Tensilon Universal Material Tester STA-1150) at 23 ° C. and 50% relative humidity at a peeling angle of 180 ° and a peeling speed of 300 mm / min. In accordance with the method of JIS Z0237 pressure-sensitive adhesive tape and pressure-sensitive adhesive sheet test, the adhesive strength (N / 25 mm) at the time of peeling was measured.

Moreover, about the same sample (however, it cut | judged in length 420mm x width 320mm) about the object which measured the said adhesive force, the sample was peeled from the non-alkali glass plate by human hand, and real rework property was evaluated on the following reference | standard. The evaluation of the actual reworkability was made by three steps according to the above procedure, and repeated three times.
(Double-circle): All three sheets were peelable satisfactorily without adhesive residue and film breakage;
○: A part of the three films was broken, but was peeled off by peeling again;
Δ: All three films were broken, but were peeled off by peeling again;
X: Adhesive residue was generated on all three sheets, or the film was broken and could not be removed even if it was peeled many times.

  As described above, the reworkability of each sample was determined by integrating the results of adhesive strength and actual reworkability.

〔optical properties〕
The central part of each sample bonded to the alkali-free glass after durability evaluation and after treatment at 60 ° C. and 95% RH for 500 hours is an integrating sphere type transmittance measuring machine (manufactured by Murakami Color Research Laboratory: DOT-3C). Using this, the single transmittance (%) Ts was measured, and the reduction (%) in transmittance from the durability evaluation before (initial) after the treatment at 60 ° C. and 95% RH for 500 hours was evaluated as an optical characteristic.

  As is clear from Table 3 above, the thin polarizing plates with adhesive layer using the adhesive composition of the present invention (Examples 1 to 11) can be easily peeled off and bonded. It was found to be excellent in durability against endurance tests by heating and humidification in the state. Furthermore, in any of the polarizing plates with pressure-sensitive adhesive layers (Examples 1 to 11) using the pressure-sensitive adhesive composition of the present invention, transmission from before (initial) durability evaluation after treatment at 60 ° C. and 95% RH for 500 hours. It was found that the amount of decrease in the rate was small, that is, the optical characteristics were excellent.

Claims (10)

100 parts by weight of an adhesive resin (A),
0.5-20 parts by weight of a silicone alkoxy oligomer (B) having an epoxy equivalent of 100-2000 g / mol and an alkoxyl group content of 5-60% by weight;
The pressure-sensitive adhesive resin (A) comprises an acrylic pressure-sensitive adhesive resin (A1), a urethane-based pressure-sensitive adhesive resin (A2), and a polyester-based pressure-sensitive adhesive resin (A3) obtained by polymerizing a monomer that does not contain a carboxyl group. Ri least one der selected from the group,
The crosslinking agent (C) is contained in an amount of 0.01 to 20 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin (A).
The pressure-sensitive adhesive composition , wherein the crosslinking agent (C) is at least one selected from an isocyanate compound and a peroxide .   The pressure-sensitive adhesive composition according to claim 1, wherein the number average molecular weight of the silicone alkoxy oligomer (B) is 300 to 10,000. The pressure-sensitive adhesive composition according to claim 1 or 2 , wherein the pressure-sensitive adhesive resin (A) contains a hydroxyl group. The pressure-sensitive adhesive composition according to any one of claims 1 to 3 , further comprising 0.001 to 5 parts by weight of a silane coupling agent (D) with respect to 100 parts by weight of the pressure-sensitive adhesive resin (A). Stuff. The pressure-sensitive adhesive composition according to any one of claims 1 to 4 , wherein the pressure-sensitive adhesive resin (A) has a weight average molecular weight of 20,000 to 2.5 million. The adhesive layer formed by the adhesive composition of any one of Claims 1-5 . An optical member comprising the pressure-sensitive adhesive layer according to claim 6 formed on at least one side of the optical film. The optical member of Claim 7 which has an easily bonding layer between the said optical film and the said adhesive layer. The optical film is a polarizing plate;
The optical member according to claim 7 or 8 , wherein the polarizing plate has a thickness of 100 µm or less. An image display device using at least one optical member according to any one of claims 7 to 9 .