JP2009209279A - Pressure-sensitive adhesive for optical member and optical member, and photo- and/or heat-crosslinking pressure-sensitive adhesive composition for optical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive for an optical member, the adhesive free from foaming or peeling between the pressure-sensitive adhesive layer and a glass substrate even in a high temperature environment or repeated environmental changes between a low temperature and a high temperature, and excellent in durability such that a light leakage phenomenon caused by shrinkage of an optical film can be suppressed. <P>SOLUTION: The pressure-sensitive adhesive for an optical member comprises a resin composition [I] containing a polyester resin (A) and an unsaturated group-containing compound (B), where the coposition is crosslinked by light and/or heat. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention is an optical film (polarizing film, retardation film, optical compensation film, brightness enhancement film, etc.) suitably used for image display devices such as liquid crystal display devices, organic EL display devices, and PDPs. Adhesive for optical member for bonding optical laminate covered with protective film such as cellulose acetate film and glass substrate of liquid crystal cell, and optical member provided with such adhesive layer, especially with adhesive layer The present invention relates to a pressure-sensitive adhesive composition for optical and / or heat-crosslinking optical members for forming a polarizing plate, and further, a pressure-sensitive adhesive for optical members.
More specifically, even under harsh environments, foaming and peeling do not occur between the pressure-sensitive adhesive layer and the glass substrate, and the light leakage phenomenon caused by the contraction of the optical film can be suppressed. The present invention relates to an excellent pressure-sensitive adhesive for optical members, an optical member, and a pressure-sensitive adhesive composition for optical members.

  Conventionally, a polarizing film, for example, a polarizing plate coated with a cellulose film, for example, a cellulose triacetate film, on both sides of a polarizing film, for example, a polyvinyl alcohol film having a polarizing property, is a liquid crystal component that is aligned between two glass plates. Lamination is carried out on the surface of the sandwiched liquid crystal cell to form a liquid crystal display panel, and this lamination to the liquid crystal cell surface is performed by contacting the cell surface with an adhesive layer provided on the polarizing plate surface, It is usually done by pressing.

With respect to the pressure-sensitive adhesive used for such polarizing plates and phase difference plates, in Patent Document 1, it is obtained by irradiating active energy rays to a pressure-sensitive adhesive material containing an acrylic copolymer, an active energy ray-curable compound, and a crosslinking agent. A pressure-sensitive adhesive exhibiting a high storage elastic modulus has been disclosed, and it has been proposed that it has excellent adhesion durability and excellent light leakage prevention properties even under conditions of high temperature and high humidity.
In Patent Document 1, an active energy ray-curable compound is used in combination with an acrylic resin and cured by active energy ray irradiation, whereby a pressure-sensitive adhesive having a high storage modulus, that is, a hard pressure-sensitive adhesive is used. ing.

JP 2006-235568 A

  However, the disclosed technique disclosed in Patent Document 1 is excellent in adhesiveness between the optical laminate and the glass substrate under high temperature and high humidity conditions, and does not cause foaming or peeling between the pressure-sensitive adhesive and the glass substrate. However, the suppression of the light leakage phenomenon caused by the shrinkage of the optical film was insufficient. In recent years, as the size of liquid crystal televisions and the like has further increased, the size of polarizing plates used has also increased, so suppression of the light leakage phenomenon has become a very important issue, and is becoming increasingly important. There is a need for a performance optical laminate.

  Therefore, in the present invention, under such a background, even in repeated high-temperature environments and low-temperature to high-temperature environmental changes, the optical laminate, particularly the adhesive property between the polarizing plate and the glass substrate is excellent, and the pressure-sensitive adhesive layer and glass Adhesive for optical members excellent in durability, such as foaming and peeling between the substrate and suppression of light leakage caused by contraction of polarizing film, and optical member with such an adhesive layer Is intended to provide.

  However, as a result of intensive studies in view of such circumstances, the present inventor has obtained a pressure-sensitive adhesive obtained by using a polyester resin instead of an acrylic resin that is widely used as a pressure-sensitive adhesive for optical members. However, it was found that it had excellent durability, particularly excellent light leakage suppression performance, and completed the present invention.

That is, the gist of the present invention is an optical system characterized in that the resin composition [I] containing the polyester resin (A) and the unsaturated group-containing compound (B) is crosslinked by light and / or heat. The present invention relates to a pressure-sensitive adhesive for members. In this invention, the optical member with an adhesive layer formed by laminating | stacking the said adhesive for optical members on an optical member is also provided.
Moreover, in this invention, the adhesive composition for optical members for forming the said adhesive for optical members is also provided.

  The pressure-sensitive adhesive for optical members of the present invention is excellent in adhesiveness between the optical laminate and the glass substrate even in a high-temperature environment and in the repetition of a low-temperature to high-temperature environment change, and between the pressure-sensitive adhesive and the glass substrate. In addition to foaming and peeling, the light leakage phenomenon caused by contraction of the optical film can be suppressed.

In the present invention, the greatest feature is to obtain a pressure-sensitive adhesive using a polyester resin instead of an acrylic resin.
In general, a pressure-sensitive adhesive mainly composed of a polyester-based resin has a very small molecular weight compared to a pressure-sensitive adhesive made of an acrylic resin (acrylic pressure-sensitive adhesive: usually about 500,000 to 1,000,000; (1 million or more for board use, polyester-based pressure-sensitive adhesive: about 5,000 to 100,000), and further, an acrylic resin capable of easily adjusting the functional group concentration by copolymerization composition and introducing a large number of functional groups into one polymer. In comparison, polyester resins usually have a diol component and a dicarboxylic acid component, so that they have a functional group at the end of the molecular chain, and it is difficult to introduce the functional group into the molecular chain, making it difficult to adjust the concentration of the functional group. There is a difficulty.
Therefore, when a polyester-based resin is used as an adhesive, because there are few reactive sites with the crosslinking agent, crosslinking by the crosslinking agent occurs, but there is a tendency for the molecular chain to be less entangled with less molecular branching, It was recognized that the gel fraction would not rise too high.
Therefore, even when an unsaturated compound is polymerized in a polyester resin as in Patent Document 1, physical interaction between the polymer and the main polyester resin (formation of a network by physical crosslinking) occurs. In the present invention, surprisingly, by using an adhesive mainly composed of a polyester resin, durability superior to an adhesive made of an acrylic resin, particularly light resistance, was surprisingly used in the present invention. It has been found that leakage can be obtained.

  In addition, in order to use an adhesive as a pressure-sensitive adhesive for optical members having excellent durability, particularly light leakage resistance, it is required to be a hard adhesive with a high storage elastic modulus. , Because tack is smaller and harder than acrylic adhesives, it is necessary for acrylic adhesives with large tacks, such as "Increased crosslinking density to increase hardness by curing together with unsaturated compounds" In general, it has been found that, even in a polyester-based resin, an excellent effect is exhibited by curing together with an unsaturated compound.

The present invention is described in detail below.
The present invention provides a pressure-sensitive adhesive composition for optical and / or heat-crosslinking optical members, comprising a resin composition [I] containing a polyester-based resin (A) and an unsaturated group-containing compound (B). Then, the present invention provides an optical member pressure-sensitive adhesive obtained by crosslinking the resin composition [I] with light and / or heat, and an optical member provided with the pressure-sensitive adhesive layer.

  The polyester resin (A) used in the present invention may be any polyester resin used for pressure-sensitive adhesives. For example, a dicarboxylic acid component and a diol component are essential components, and a trivalent or higher polyvalent carboxylic acid is used as necessary. A known general polyester resin composed of an acid component and / or a trihydric or higher polyhydric alcohol component can be used.

Examples of the dicarboxylic acid component in the present invention include succinic acid, methyl succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, pimelic acid, decanedicarboxylic acid, octadecanedicarboxylic acid, 1,12-dodecanoic acid, 1,14. -Aliphatic acyclic dicarboxylic acid such as tetradecanoic acid, dimer acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanediacetic acid, 1, Aliphatic cyclic dicarboxylic acids such as 3-cyclohexanediacetic acid, 1,4-cyclohexanediacetic acid, fumaric acid, maleic acid, itaconic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, hexahydrophthalic acid, dimer acids, etc. Unsaturated dicarboxylic acid, terephthalic acid, isophthalic acid , Benzenedicarboxylic acids such as orthophthalic acid, aromatic dicarboxylic acids such as 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and 4,4'-biphenyldicarboxylic acid, and acid anhydrides and lower alkyl esters thereof These can be used alone or in combination of two or more.
Among these, it is preferable to use an aromatic dicarboxylic acid or an aliphatic acyclic dicarboxylic acid. In particular, it is possible to use both an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid from the viewpoint that both durability and flexibility can be achieved. Is more preferable, and it is particularly preferable to use isophthalic acid and sebacic acid in combination.

The diol component in the present invention is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexane. Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,18-octadecanediol, linear aliphatic diol such as 1,4-cyclohexanediol, neopentyl glycol, 2- Methyl-1,3-propanediol, 1-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2- Methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propane All, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3,5-trimethyl-1,3-pentane Diol, 2-methyl-1,6-hexanediol, 2-methyl-1,8-octanediol, 2-methyl-1,9-nonanediol, dimer diol, 4-methyl-1,7-heptanediol, 3 -Hydrocarbon group in the side chain such as methyl-1,6-hexanediol, 1-methyl-1,6-hexanediol, 4-methyl-1,9-nonanediol, 3-methyl-1,9-nonanediol These can be used alone or in combination of two or more.
Among these, it is preferable to use a linear aliphatic diol and an aliphatic diol having a hydrocarbon group in the side chain in terms of being able to control the glass transition temperature so as not to cause crystallization. At least one selected from ethylene glycol, 1,4-butanediol and 1,6-hexanediol as the diol, and neopentyl glycol, 2-butyl-2-ethyl- as the aliphatic diol having a hydrocarbon group in the side chain It is particularly preferable to use in combination with at least one selected from 1,3-propanediol.

  Furthermore, as the diol component, a commercially available polyester diol component, polyether diol component, polycaprolactone diol component, polycarbonate diol component, or the like can be used in order to easily obtain a polymer having a desired molecular weight. Specifically, as the polyester diol component, for example, ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,10-decanediol, Diol components such as octadecanediol, succinic acid, methyl succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, 1,14-tetradecanedioic acid, their acid anhydrides or lower alkyl esters In a single or mixed state with a dicarboxylic acid component such as Examples of the commercially available products include polyester diols obtained by water reaction. For example, trade names “Kuraray polyol P-510”, which is a polyester diol of 3-methyl-1,5-pentanediol and adipic acid, “ Kuraray polyol P-1010 "," Kuraray polyol P-2010 "," Kuraray polyol P-3010 "," Kuraray polyol P-5010 "[manufactured by Kuraray Co., Ltd.] and the like.

  Examples of the polyether diol component include polyethylene glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like, polypropylene glycol, polytetramethylene glycol, and a copolyether obtained by copolymerizing these, and are commercially available products. For example, trade names “Adeka Polyether P-400”, “Adeka Polyether P-1000”, “Adeka Polyether P-2000”, “Adeka Poly”, which are polyether diols obtained by adding propylene oxide to propylene glycol. Ether P-3000 ”[manufactured by Asahi Denka Kogyo Co., Ltd.].

  Examples of the polycaprolactone diol component include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and δ-valerolactone, and commercially available products include, for example, trade name “PLAXEL L205AL”. ”,“ Placcel L212AL ”,“ Placcel L220AL ”,“ Placcel L220PL ”,“ Placcel L230AL ”[above, manufactured by Daicel Chemical Industries, Ltd.], and the like.

  Examples of the polycarbonate diol component include carbonate diols such as propylene carbonate diol, hexamethylene carbonate diol, 3-methylpentene carbonate diol, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6- And polycarbonate diols obtained by dealcoholization reaction of polyhydric alcohols such as hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol and dialkyl carbonates such as diethylene carbonate and dimethyl carbonate. As commercial products, for example, trade names “PLACCEL CD205”, “PLACCEL CD210”, “PLACCEL CD220”, “PLACCEL CD205PL”, “P ACCEL CD210PL "," PLACCEL CD220PL "[or more, manufactured by Daicel Chemical Industries, Ltd.] and the like.

Examples of the trivalent or higher polyvalent carboxylic acid component in the present invention include aromatic polyvalent carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid, 1,2,4-butanetricarboxylic acid, 1,2, Examples include aliphatic polycarboxylic acids such as 5-hexanetricarboxylic acid 1,2,4-cyclohexanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, and acid anhydrides and lower alkyl esters thereof. These can be used alone or in combination of two or more.
Among these, from the viewpoint of appropriately controlling the degree of dispersion, it is preferable to use a trivalent carboxylic acid, in particular, it is preferable to use a trivalent aromatic carboxylic acid, and particularly to use trimetic acid.

Examples of the trihydric or higher polyhydric alcohol component in the present invention include, for example, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2 , 6-hexanetriol, pentaerythritol, dipentaerythritol, and the like, and these are used alone or in combination of two or more.
Among these, from the viewpoint of appropriately controlling the degree of dispersion, it is preferable to use a trivalent aliphatic alcohol, and it is particularly preferable to use trimethylolpropane.

  The polyester resin (A) used in the present invention uses the dicarboxylic acid component, the diol component, the trivalent or higher polyvalent carboxylic acid component and / or the trivalent or higher polyhydric alcohol component as a polycondensation component. And obtained by polycondensation by a known method in the presence of a catalyst.

In the polycondensation reaction, an esterification reaction is first performed and then a condensation reaction is performed.
In such esterification reaction, a catalyst is used. Specifically, titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate, antimony-based compounds such as antimony trioxide, germanium-based catalysts such as germanium oxide, zinc acetate, Examples thereof include manganese acetate and dibutyltin oxide, and one or more of these are used. Among these, antimony trioxide and tetrabutyl titanate are preferable from the viewpoint of high catalyst activity.

  The blending amount of the catalyst is preferably 1 to 10,000 ppm, more preferably 10 to 5000 ppm, and still more preferably 10 to 3000 ppm with respect to all copolymer components. If the blending amount is too small, the polymerization reaction tends not to proceed sufficiently. Conversely, if the blending amount is too large, there is no advantage such as shortening of the reaction time and a side reaction tends to occur.

  About the temperature at the time of esterification, 160-260 degreeC is preferable, 180-250 degreeC is more preferable, 200-250 degreeC is further more preferable. If the temperature is too low, the reaction tends not to proceed sufficiently. Conversely, if the temperature is too high, side reactions such as decomposition tend to occur. Moreover, a pressure is normally implemented under a normal pressure.

  After the esterification reaction is performed, a condensation reaction is performed. The conditions at this time are such that the same amount of catalyst as in the above esterification is further added and the reaction temperature is preferably 220. It is preferable that the reaction system is gradually reduced in pressure to ˜260 ° C., more preferably 230 to 250 ° C., and the reaction is finally performed at 5 hPa or less. If the reaction temperature is too low, the reaction tends not to proceed sufficiently, while if it is too high, side reactions such as decomposition tend to occur.

  A polyester resin (A) can be obtained by performing the reaction according to the above method.

  The number average molecular weight of the polyester resin (A) is preferably 5000 or more, more preferably 10,000 to 100,000, and particularly preferably 15,000 to 80,000. If the number average molecular weight is too small, sufficient cohesive force as an adhesive cannot be obtained, and heat resistance and mechanical strength tend to decrease, and if it is too large, flexibility is lost, initial adhesiveness decreases, and acupressure level There is a tendency that sufficient adhesive force cannot be exhibited at a pressure of.

  The weight average molecular weight of the polyester resin (A) is preferably 10,000 or more, particularly preferably 20,000 or more, and further preferably 50,000 or more. If the weight average molecular weight is too small, sufficient cohesive force as a pressure-sensitive adhesive cannot be obtained, and heat resistance and mechanical strength tend to decrease. If it is too large, flexibility is lost, initial adhesiveness decreases, and finger pressure is reduced. There is a tendency that sufficient adhesive strength cannot be exhibited at a certain pressure.

The number average molecular weight and the weight average molecular weight are average molecular weights in terms of standard polystyrene molecular weight. High-performance liquid chromatography (manufactured by Nippon Waters Co., Ltd., “Waters 2695 (separation module)” and “Waters 2414 (detector)) )), Column: Shodex GPC KF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plates / piece, packing material: styrene-divinylbenzene Measured using three series of polymer and filler particle size: 10 μm).

  The degree of dispersion (average molecular weight / weight number average molecular weight) of the polyester resin (A) is preferably 2 or more, and more preferably 2.2 to 10. The upper limit is usually 20 or less. If the degree of dispersion is too low, sufficient heat resistance tends not to be exhibited. If the degree of dispersion is too high, gelation tends to occur and the adhesive strength tends to decrease.

  The degree of dispersion depends on the content of the trihydric or higher polyhydric alcohol component and / or trihydric or higher polyhydric carboxylic acid component for constituting the polyester resin (A), and the condensation reaction conditions (temperature, degree of vacuum, Stirring, reaction time, etc.).

  The glass transition temperature of the polyester resin (A) is preferably −10 ° C. or lower, and more preferably −20 ° C. or lower. The lower limit value of the glass transition temperature is usually preferably −80 ° C. or higher, more preferably −70 ° C. or higher. If the glass transition temperature is too high, the flexibility is lost, the initial tackiness is lowered, and there is a tendency that sufficient adhesive force cannot be exerted at a pressure of a finger pressure, and if it is too low, the mechanical strength and heat resistance tend to be lowered. is there.

  The polyester resin (A) is more preferably not crystallized, and even when crystallization occurs, the crystallization temperature is preferably 0 ° C. or less, particularly preferably −30 ° C. or less, and the crystallization temperature is high. If it is too much, the tack tends to disappear. The crystallization energy is also preferably as low as possible, preferably 35 J / g or less, particularly 20 J / g or less, more preferably 15 J / g or less. If the crystallization energy is too high, tack tends to disappear. .

  In the present invention, the polyester resin (A) contains a dicarboxylic acid component, a diol component containing a glycol having a hydrocarbon group in the side chain, a trivalent or higher polyhydric alcohol and / or a trivalent or higher polyvalent. A polycondensation of a polyvalent carboxylic acid and containing 0.1 to 5 mol% of a structural moiety derived from a trivalent or higher polyhydric alcohol and / or a trivalent or higher polyvalent carboxylic acid in the polyester resin Polyester resin (A ′) is preferable from the viewpoint of increasing durability.

  The dicarboxylic acid component in the polyester resin (A ′) preferably contains an aromatic dicarboxylic acid from the viewpoint of mechanical strength and heat resistance. In particular, an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid are used in combination. It is preferable to use it. As the aromatic dicarboxylic acid, benzidine dicarboxylic acids are preferably used, and terephthalic acid and isophthalic acid are particularly preferable.

  Such a structural site derived from an aromatic dicarboxylic acid is preferably contained in the polyester-based resin (A ′) in an amount of 5 to 35 mol%, and more preferably 10 to 30 mol%. If the content is too small, the heat resistance and mechanical strength tend to decrease. If the content is too large, the flexibility is lost, the initial tackiness decreases, and sufficient adhesive strength tends not to be exhibited at a pressure of about a finger pressure. There is.

In such a polyester-based resin (A ′), it is preferable that a structural part derived from glycol having a hydrocarbon group in the side chain is contained in the polyester-based resin (A ′) in an amount of 3 to 50 mol%, and more preferably 5 to 40. It is more preferable to contain mol%.
When the content is too small, crystallization occurs and tack tends to disappear. When the content is too large, it tends to be difficult to obtain a high molecular weight polyester resin.

Moreover, it is preferable that the structural site derived from a trivalent or higher polyvalent carboxylic acid component and / or a trivalent or higher polyhydric alcohol component is contained in the polyester resin (A ′) in an amount of 0.1 to 5 mol%. Furthermore, it is especially preferable to contain 0.1-2.5 mol%, and it is especially preferable to contain 0.2-2 mol%.
When the content is too small, the heat resistance tends to decrease, and when the content is too large, gelation occurs and the adhesive strength tends to decrease.

In obtaining such a polyester-based resin (A ′), it is preferable to add the aromatic dicarboxylic acid in an amount of 10 to 70 mol%, more preferably 20 to 60 mol%, based on the entire acid component.
If the amount of the aromatic dicarboxylic acid charged is too small, the heat resistance and mechanical strength tend to decrease, and if it is too large, the flexibility is lost and the initial tackiness decreases, and sufficient adhesive strength can be obtained with a pressure of about a finger pressure. There is a tendency to become unable to demonstrate.
The total acid component includes a trivalent or higher polyvalent carboxylic component when a trivalent or higher polyvalent carboxylic acid component is used.

Moreover, it is preferable to charge 5-100 mol% of glycol which has a hydrocarbon group in a side chain with respect to the whole polyhydric alcohol component, and it is still more preferable to charge 10-80 mol%. If the amount of glycol (b1) having a hydrocarbon group in the side chain is too small, crystallization occurs and tack tends to disappear.
The whole polyhydric alcohol component includes a trihydric or higher polyhydric alcohol component when a trihydric or higher polyhydric alcohol component is used.

  Furthermore, it is preferable to add 0.1 to 5 mol% of a trivalent or higher polyvalent carboxylic acid component and / or a trivalent or higher polyhydric alcohol component with respect to the total polycondensation component, and 0.2 to 2.5 More preferably, it is charged in mol%. If the amount charged is too small, the heat resistance tends to decrease, and if too large, gelation occurs and the adhesive strength tends to decrease.

  As a blending ratio of the acid component and the polyhydric alcohol component, the polyhydric alcohol component is preferably 1 to 2 equivalents, more preferably 1.2 to 1.7 equivalents per equivalent of the acid component. If the polyhydric alcohol component is too small, the acid value tends to be high and it tends to be difficult to increase the molecular weight, and if it is too large, the yield tends to decrease.

Furthermore, in the present invention, the polyester resin (A) is an unsaturated group-containing polyester resin into which an unsaturated group is introduced, which improves the cohesive strength of the resin, imparts durability, and suppresses light leakage. It is preferable in terms of contributing.
In that case, what is necessary is just to contain a polymerizable unsaturated group in the structure of the polyester-based resin, and preferably the one containing a polymerizable unsaturated group at the end of the main chain or the side chain of the polyester-based resin. preferable.
The polyester-based resin contains an aliphatic polyvalent carboxylic acid as an acid component and an aliphatic polyhydric alcohol as an alcohol component, and these are polycondensed. And unsaturated group containing polyester-type resin can be obtained by introduce | transducing an unsaturated group into the polyester-type resin by the method of following [1]-[4], for example.

[1] The hydroxyl group at the end of the main chain and / or the side chain of the polyester resin is reacted with the carboxyl group of the unsaturated group-containing carboxylic acid.
[2] The carboxyl group of the main chain end and / or side chain end of the polyester resin is reacted with the hydroxyl group of the unsaturated group-containing alcohol.
[3] After reacting the hydroxyl group and / or carboxyl group of the main chain end and / or side chain end of the polyester resin with a part of the isocyanate group of the polyisocyanate compound, the remaining isocyanate group and The carboxyl group of the saturated group-containing carboxylic acid or the hydroxyl group of the unsaturated group-containing alcohol is reacted.
[4] The isocyanate group of the isocyanate group-containing unsaturated compound having both an isocyanate group and an unsaturated group is reacted with the hydroxyl group and / or carboxyl group at the main chain end and / or side chain end of the polyester resin.
In addition, it is preferable that the unsaturated group of the unsaturated group-containing polyester resin (A) is a (meth) acryloyl group from the viewpoint of easy curing by ultraviolet rays.

Examples of the unsaturated group-containing compound (B) include urethane (meth) acrylate compounds and ethylenically unsaturated monomers having one or more ethylenically unsaturated groups in one molecule, such as monofunctional monomers, 2 A functional monomer, a trifunctional or higher monomer can be used.
Among these, it is preferable to use a urethane (meth) acrylate compound, and in order to further improve the adhesion to a substrate or an adherend, a highly polar urethane (meth) acrylate compound or ethylene having a polar site. It is preferable to use a polymerizable unsaturated monomer.
In order to increase the crosslinking density of the pressure-sensitive adhesive, it is also preferable to use a compound having three or more unsaturated groups.

  A urethane (meth) acrylate compound is a (meth) acrylate compound having a urethane bond in the molecule, a (meth) acrylic compound containing a hydroxyl group, a polyvalent isocyanate compound, and a polyol as necessary. Can be produced by reaction.

  Examples of the (meth) acrylic compound containing a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, 6-hydroxyhexyl (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, caprolactone modified 2-hydroxy Ethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, caprolactone modified pen Examples include erythritol tri (meth) acrylate, ethylene oxide-modified dipentaerythritol penta (meth) acrylate, ethylene oxide-modified pentaerythritol tri (meth) acrylate, etc. Among them, a hydroxyl group-containing (meth) acrylic group having three or more acryloyl groups A compound is preferably used. Moreover, these can be used 1 type or in combination of 2 or more types.

  The polyvalent isocyanate compound is not particularly limited, and examples thereof include aromatic, aliphatic, and alicyclic polyisocyanates, among which tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, Polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis (isocyanato) Methyl) cyclohexane, phenylene diisocyanate, lysine diisocyanate, lysine triisocyanate And polyisocyanates such as naphthalene diisocyanate or trimer compounds or multimeric compounds of these polyisocyanates, burette type polyisocyanates, water-dispersed polyisocyanates (for example, “Aquanate 100” manufactured by Nippon Polyurethane Industry Co., Ltd., ("Aquanate 110", "Aquanate 200", "Aquanate 210", etc.), or the reaction products of these polyisocyanates and polyols.

  Examples of such polyols include, but are not limited to, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, 1,6 -Hexanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, trimethylolethane, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, glycerin, polyglycerin, poly Polyhydric alcohols such as tetramethylene glycol; polyethylene oxide, poly Polyether polyol having at least one structure of propylene oxide, ethylene oxide / propylene oxide block or random copolymerization; the polyhydric alcohol or polyether polyol and maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itacone Examples include polyester polyols that are condensates of polybasic acids such as acids, adipic acid, and isophthalic acid; caprolactone-modified polyols such as caprolactone-modified polytetramethylene polyol; polyolefin-based polyols; polybutadiene-based polyols such as hydrogenated polybutadiene polyol, and the like. .

  Furthermore, as such polyols, for example, 2,2-bis (hydroxymethyl) butyric acid, tartaric acid, 2,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxyethyl) propionic acid, 2,2-bis (hydroxypropyl) propionic acid, dihydroxymethylacetic acid, bis (4-hydroxyphenyl) acetic acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid Also included are carboxyl group-containing polyols such as homogentisic acid, sulfonic acid group or sulfonate group-containing polyols such as sodium 1,4-butanediol sulfonate, and the like.

  When using the reaction product of polyisocyanate and polyol, for example, it may be used as a terminal isocyanate group-containing polyisocyanate obtained by reacting the polyol with the polyisocyanate. In the reaction between the polyisocyanate and the polyol, a metal catalyst such as dibutyltin dilaurate or an amine catalyst such as 1,8-diazabicyclo [5.4.0] undecene-7 is used for the purpose of promoting the reaction. Is also preferable.

  As a manufacturing method of the said urethane (meth) acrylate type compound, it does not restrict | limit in particular, For example, a hydroxyl-containing (meth) acrylic-type compound and a polyvalent isocyanate compound are mixed in inert gas atmosphere, Usually, 30-80 degreeC, The method of making it react for 2 to 10 hours is mentioned. In this reaction, it is preferable to use a urethanization catalyst such as tin octenoate, di-n-butyltin dilaurate, lead octylate, potassium octylate, potassium acetate, stannous octoate, or triethylenediamine.

  In addition, among the isocyanate groups of the raw polyvalent isocyanate, a urethane (meth) acrylate compound having an isocyanate group and an unsaturated bond in the molecule in which a part of the isocyanate group is left unreacted is used. It is also effective to create a crosslinking point with the resin (A) and increase the cohesive strength of the adhesive.

  The weight average molecular weight of the urethane (meth) acrylate compound is preferably 300 to 4000, more preferably 1000 to 3500, and particularly preferably 1200 to 3000. If the important average molecular weight is too small, the cohesive force tends to be insufficient after curing, and if it is too large, the viscosity becomes too high and the production tends to be difficult. The method for measuring the weight average molecular weight is the same as described above.

  The monofunctional monomer may be any monomer containing one ethylenically unsaturated group. For example, styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meta ) Acrylate, acrylonitrile, vinyl acetate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (Meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl ( ) Acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) ) Acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide Modified (meth) acrylate, nonylphenol propylene oxide modified (meth) acrylate, phthalic acid such as 2- (meth) acryloyloxy-2-hydroxypropyl phthalate Derivative half-ester (meth) acrylate, furfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethylacrylamide N-methylol (meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, 2- (meth) acryloyloxyethyl acid phosphate monoester, and the like.

  Examples of the ethylenically unsaturated monomer include a Michael adduct of acrylic acid or 2-acryloyloxyethyldicarboxylic acid monoester in addition to the above. Examples of the Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, and acrylic acid. Examples include trimers, methacrylic acid trimers, acrylic acid tetramers, and methacrylic acid tetramers. Examples of 2-acryloyloxyethyl dicarboxylic acid monoester which is a carboxylic acid having a specific substituent include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylate is also mentioned.

  The bifunctional monomer may be any monomer containing two ethylenically unsaturated groups. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol Di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide Modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate 1,6-hexanediol ethylene oxide modified di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) Examples include acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, and 2- (meth) acryloyloxyethyl acid phosphate diester.

  The tri- or higher functional monomer may be any monomer containing three or more ethylenically unsaturated groups. For example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin Polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate, ethylene oxide modified dipentaerythritol pen (Meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, ethylene oxide modified pentaerythritol tetra (meth) acrylate, succinic acid modified pentaerythritol tri (meth) acrylate, etc. Is mentioned.

  These urethane (meth) acrylate compounds and ethylenically unsaturated monomers constituting the unsaturated group-containing compound (B) may be used alone or in combination of two or more.

  As content of an unsaturated group containing compound (B), 5-100 weight part is preferable with respect to 100 weight part of polyester-type resin (A), More preferably, it is 6-50 weight part, More preferably, it is 8-40 weight. Part. If the content is too large, the adhesive strength tends to be too low and sticking to the adherend tends to be difficult. If the content is too small, the crosslinking density tends to decrease and the light leakage suppression property tends to be reduced.

  In addition, it is preferable that resin composition [I] in this invention has a polyester-type resin (A) and an unsaturated group containing compound (B) as a main component, and a main component is resin composition [I] ] The total amount of the polyester resin (A) and the unsaturated group-containing compound (B) is usually 50% by weight or more, preferably 60% by weight or more, and more preferably 70% by weight or more based on the total amount. That means.

  In the present invention, the resin composition [I] containing the polyester-based resin (A) and the unsaturated group-containing compound (B) is crosslinked by light and / or heat, and becomes a pressure-sensitive adhesive. .

  As for the crosslinking method, there are (1) a method of crosslinking by light and / or heat and (2) a method of crosslinking by a crosslinking agent. In the present invention, (1) crosslinking by light and / or heat. In addition, it is preferable to use (2) cross-linking with a cross-linking agent in combination because the cross-linking density of the pressure-sensitive adhesive is increased, the cohesive force is increased, and light leakage suppression and durability can be balanced.

First, (1) a method of crosslinking by light and / or heat will be described.
In the case of crosslinking by light and / or heat, the resin composition [I] further contains a polymerization initiator (C) in addition to the polyester resin (A) and the unsaturated group-containing compound (B). Is preferred. In the case of such cross-linking, the unsaturated group-containing compound (B) is polymerized (polymerized) with light and / or heat to carry out cross-linking (physical cross-linking) with the polyester resin (A). When the polyester resin (A) is an unsaturated group-containing polyester resin, the unsaturated group-containing polyester resin (B) is not limited to polymerization of the unsaturated group-containing compound (B) by light and / or heat. Polymerization of A) with the unsaturated group-containing compound (B) will be considered.

  The polymerization initiator (C) is not particularly limited, and various polymerization initiators such as a photopolymerization initiator (C1) and a thermal polymerization initiator (C2) can be used. Use of the photopolymerization initiator (C1) is preferable in that it can be cured by irradiation with active energy rays such as ultraviolet rays for a very short time.

  In addition, when the photopolymerization initiator (C1) is used, the resin composition [I] is crosslinked by irradiation with active energy rays, and when the thermal polymerization initiator is used, the resin composition [I] is crosslinked by heat. However, it is also preferable to use both in combination as necessary.

  Examples of the photopolymerization initiator (C1) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4- Acetophenones such as morpholinophenyl) butanone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl Ether etc. Zoins; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium Benzophenones such as chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy ) − Thioxanthones such as 2,4-dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl -Acyl phosphine oxides such as pentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; In addition, as for these photoinitiators (C1), only 1 type may be used independently and 2 or more types may be used together.

  These auxiliary agents include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid. Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone Etc. can be used in combination.

  Among these, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoyl isopropyl ether, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1- It is preferable to use phenylpropan-1-one.

  Examples of the thermal polymerization initiator (C2) include methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetate peroxide, 1,1-bis (t-hexylperoxy). −3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1 -Bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (T-Butylperoxy) butane, 2,2-bis (4,4- -T-butylperoxycyclohexyl) propane, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t- Butyl cumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide Oxide, octanoyl peroxide Id, lauroyl peroxide, stearoyl peroxide, succinic acid peroxide, m-toluoyl benzoyl peroxide, benzoyl peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butyl) (Cyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethoxyhexyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-s-butyl peroxydicarbonate, Di (3-methyl-3-methoxybutyl) peroxydicarbonate, α, α′-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethyl Rubutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypi Valate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) ) Hexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-hexyl Peroxyisopropyl monocarbonate, t-butyl peroxyisobutyrate, t-butyl Tilperoxymalate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropylmonocarbonate, t-butylperoxy-2-ethylhexyl Monocarbonate, t-butylperoxyacetate, t-butylperoxy-m-toluylbenzoate, t-butylperoxybenzoate, bis (t-butylperoxy) isophthalate, 2,5-dimethyl-2,5-bis (M-toluylperoxy) hexane, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyallyl monocarbonate, t-butyltrimethylsilyl peroxide, 3,3 ′, 4,4′-tetra (t-bu Organic peroxide initiators such as tilperoxycarbonyl) benzophenone and 2,3-dimethyl-2,3-diphenylbutane; 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 1-[(1 -Cyano-1-methylethyl) azo] formamide, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobisiso Butyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2,2′-azobis (2-methyl-N-phenylpropylene) Onamidine) dihydrochloride, 2,2′-azobis [N- (4-chlorophenyl) -2-methylpropionamidine] dihydride chloride 2,2′-azobis [N- (4-hydrophenyl) -2-methylpropionamidine] dihydrochloride, 2,2′-azobis [2-methyl-N- (phenylmethyl) propionamidine] dihydrochloride, 2, , 2′-azobis [2-methyl-N- (2-propenyl) propionamidine] dihydrochloride, 2,2′-azobis [N- (2-hydroxyethyl) -2-methylpropionamidine] dihydrochloride, 2, 2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2, 2′-azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (5-hydroxy-3,4,5, 6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane] dihydrochloride, 2,2 ′ -Azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis [2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide], 2,2′-azobis [2-methyl-N- [1,1-bis (hydroxymethyl) ethyl] propionamide], 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propyl Lopionamide], 2,2′-azobis (2-methylpropionamide), 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane), dimethyl- Initiation of azo compounds such as 2,2-azobis (2-methylpropionate), 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis [2- (hydroxymethyl) propionitrile] Agents; and the like. In addition, only 1 type may be used independently for these thermal polymerization initiators, and 2 or more types may be used together.

  In the active energy ray irradiation, in addition to rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, electromagnetic waves such as X rays and γ rays, electron beams, proton rays, neutron rays, etc. can be used. Curing by ultraviolet irradiation is advantageous from the standpoint of availability of the device and price. In addition, when performing electron beam irradiation, it can harden | cure without using a photoinitiator (C1).

As a light source for such ultraviolet irradiation, a high pressure mercury lamp, an electrodeless lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, or the like is used. In the case of a high-pressure mercury lamp, for example, it is performed under conditions of 5 to 3000 mJ / cm ² , preferably 10 to 1000 mJ / cm ² . In the case of an electrodeless lamp, it is performed under the conditions of, for example, ^{2 to} 1500 mJ / cm ² , preferably 5 to 500 mJ / cm ² . The irradiation time varies depending on the type of light source, the distance between the light source and the coating surface, the coating thickness, and other conditions, but it may be usually from several seconds to several tens of seconds, and in some cases, may be a fraction of a second. In the case of electron beam irradiation, for example, an electron beam having an energy in the range of 50 to 1000 Kev is used, and the irradiation amount is preferably 2 to 50 Mrad.

  Moreover, when using a thermal-polymerization initiator (C2) as a polymerization initiator (C), a crosslinking reaction is started and advanced by heating.

  About content of said polymerization initiator (C), 0.01-10 weight part with respect to 100 weight part of polyester-type resin (A), Especially 0.1-7 weight part, Furthermore, 0.3 It is preferably ~ 3 parts by weight. If the content is too small, the curability tends to be poor and the physical properties tend to become unstable, and if it is too much, no further effect tends to be obtained.

  When performing the above crosslinking, either photocrosslinking or thermal crosslinking may be used, but photocrosslinking and thermal crosslinking may be used in combination as necessary.

Next, (2) a method of crosslinking with a crosslinking agent will be described.
In the case of crosslinking with a crosslinking agent, the resin composition [I] contains a crosslinking agent (D) in addition to the polyester resin (A) and the unsaturated group-containing compound (B). Crosslinking (chemical crosslinking) is carried out by reacting such a crosslinking agent with a functional group of the polyester resin (A).

The crosslinking agent (D) may be any compound having a functional group that reacts with the functional group contained in the polyester resin (A). For example, bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene Glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, di Epoxy compounds such as glycerol polyglycidyl ether, tetramethylolmethane-tri-β-aziridinylpropionate, trimethylo Rupropane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), N, N′-hexamethylene-1,6-bis (1- Aziridine compounds such as aziridinecarboxamide), melamine compounds such as hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaptoxymethylmelamine, hexapentyloxymethylmelamine, hexahexyloxymethylmelamine, melamine resin For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, hexamethylene diisocyanate, di Phenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and their polyisocyanate compounds and tri Adducts with polyol compounds such as methylolpropane, isocyanate compounds such as bullets and isocyanurates of these polyisocyanate compounds, glyoxal, malondialdehyde, succindialdehyde, maleindialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, Aldehyde compounds such as benzaldehyde, hexamethylenediamine, triethyldiamine, polyethyleneimine, Axamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resins, amine compounds such as polyamide, aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, panadium, chromium, zirconium, etc. Examples include metal chelate compounds such as multi-metallic acetylacetone and acetoacetyl ester coordination compounds. Among them, isocyanate compounds are preferred in terms of improving adhesion to the base material and reactivity with the base polymer. Used.
Moreover, these crosslinking agents (D) may be used independently and may be used together 2 or more types.

  The content of the crosslinking agent (D) can be appropriately selected depending on the amount of the functional group contained in the polyester resin (A), the molecular weight of the polyester resin (A), and the purpose of use. Usually, the polyester resin (A ) 100 to 15 parts by weight, preferably 0.1 to 15 parts by weight, more preferably 0.2 to 12 parts by weight, and particularly preferably 1.5 to 10 parts by weight.

  When the amount of the crosslinking agent (D) is too small, the cohesive force tends to be insufficient and sufficient durability tends not to be obtained. When the amount is too large, the flexibility and adhesive strength are lowered, the durability is deteriorated, and peeling occurs. Since it becomes easy, there exists a tendency for bonding with an optical film to become difficult.

  When the crosslinking agent (D) is used, the cohesive force of the pressure-sensitive adhesive layer is increased, the durability performance tends to be good, and the adhesion with the substrate tends to be improved, Even when the cross-linking agent (D) is not used, aging (curing period) after the adhesive processing is not necessary, which is economically advantageous.

  In the present invention, it is preferable that the resin composition [I] forming the pressure-sensitive adhesive layer further contains a silane coupling agent (E) in terms of improving the adhesion to the optical laminate. About content of a silane coupling agent (E), 0.001-10 weight part with respect to 100 weight part of polyester-type resin (A), Especially 0.01-1 weight part, Furthermore, 0.03- It is preferable that it is 0.8 weight part. If the content is too small, the addition effect tends not to be obtained. If the content is too large, the compatibility with the polyester-based resin (A) is poor and the adhesive force and cohesive force tend not to be obtained.

  Examples of the silane coupling agent (E) include epoxy silane, acrylic silane, mercapto silane, hydroxyl group silane, carboxyl group silane, amino group silane, amide group silane, and isocyanate group silane. These may be used singly or in combination of two or more. Among these, epoxy silane compounds and mercapto silanes are preferably used. Further, by using an epoxy-based silane compound and a mercapto-based silane in combination, it is possible to improve wet heat durability and suppress an increase in adhesive strength.

  Specific examples of such epoxy silanes include, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycidoxypropylmethyl. Dimethoxysilane, methyltri (glycidyl) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. Among them, γ-glycid is preferable. Xylpropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane.

  Specific examples of such mercapto silanes include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyldimethoxymethylsilane, and the like.

  In the present invention, it is also preferable that the resin composition [I] forming the pressure-sensitive adhesive layer further contains an antistatic agent (F) in order to improve the antistatic performance of the obtained pressure-sensitive adhesive. Examples of the antistatic agent (F) include cationic antistatic agents of quaternary ammonium salts such as tetraalkylammonium sulfonates, aliphatic sulfonates, higher alcohol sulfate esters, higher alcohol alkylene oxide adduct sulfuric acid. Anionic antistatic agents such as ester salts, higher alcohol phosphate esters, higher alcohol alcohol alkylene oxide adduct phosphate esters, alkali metal salts of organic or inorganic acids such as lithium perchlorate and lithium chloride, alkaline earths Metal salts, higher alcohol alkylene oxide adducts, polyalkylene glycol fatty acid esters and the like.

  In the resin composition [I] forming the pressure-sensitive adhesive layer in the present invention, acrylic pressure-sensitive adhesives, other pressure-sensitive adhesives, urethane resins, rosins, rosin esters, hydrogenated rosins are further included within the range not impairing the effects of the present invention. Coloring by tackifiers such as esters, phenol resins, aromatic modified terpene resins, aliphatic petroleum resins, alicyclic petroleum resins, styrene resins, xylene resins, known additives, and ultraviolet or radiation irradiation Alternatively, a compound that causes discoloration can be added.

Thus, in the present invention, an adhesive for optical members obtained by crosslinking the above resin composition [I] with light and / or heat is obtained, and such an adhesive is placed on the optical member (optical laminate). By providing, an optical member with an adhesive layer can be obtained.
The optical member with the pressure-sensitive adhesive layer is preferably further provided with a release sheet on the surface opposite to the optical member of the pressure-sensitive adhesive layer.

The method for producing the optical member with the pressure-sensitive adhesive layer is not particularly limited. (1) A method of further bonding a release sheet after applying and drying the resin composition [I] on the optical member. Or (2) The resin composition [I] is applied on the release sheet, dried, and then manufactured by a method of laminating the optical member. The resin composition on the release sheet of (2) The production method of applying [I] is preferable in that the possibility that the substrate is deteriorated by the diluting solvent is low.
In practical use, the release sheet is peeled off and used, and the release sheet is preferably a silicon-based release sheet.

  When the resin composition [I] is crosslinked by light and / or heat, (1) the resin composition [I] is applied on the optical member and dried, and then a release sheet is bonded. , A method of irradiating with active energy rays and / or heat treatment, (2) applying and drying the resin composition [I] on a release sheet, and then bonding an optical member, irradiating with active energy rays and / or heating. (3) A method of applying a resin composition [I] on an optical member, drying it, further irradiating it with active energy rays and / or heat-treatment, and then bonding a release sheet, (4) Release The resin composition [I] can be applied on a sheet, dried, and further irradiated with active energy rays and / or heat-treated, and then manufactured by a method of bonding an optical member.

  In addition, when using together with bridge | crosslinking by light and / or heat, and bridge | crosslinking by a crosslinking agent, (1) The method of bridge | crosslinking which performs the process by light and / or heat immediately after application | coating drying of resin composition [I], 2) After applying and drying the resin composition [I], after performing a certain curing period, performing crosslinking with a crosslinking agent, then performing treatment with light and / or heat to further perform crosslinking. However, the method (1) in which treatment with light and / or heat is performed after coating and drying is preferable from the viewpoint of economy and simplicity.

  In the above application, it is preferably applied after diluting with a solvent, and the dilution concentration is preferably 10 to 70% by weight, particularly preferably 15 to 60% by weight, and further preferably 25 to 50%. Such a solvent is not particularly limited as long as it dissolves the resin composition [I]. For example, ester solvents such as methyl acetate, ethyl acetate, methyl acetoacetate, and ethyl acetoacetate, acetone, methyl ethyl ketone, A ketone solvent such as methyl isobutyl ketone and an aromatic solvent such as toluene and xylene can be used. Among these, ethyl acetate and methyl ethyl ketone are preferably used from the viewpoints of solubility, drying property, price, and the like.

  The gel fraction of the pressure-sensitive adhesive layer produced by the above method is preferably 50% or more from the viewpoint of durability performance, particularly light leakage suppression performance, and particularly preferably 50% to 90%. When the gel fraction is too low, durability due to insufficient cohesive force, particularly suppression of light leakage tends to decrease. The upper limit of the normal gel fraction is 100%.

In addition, the said gel fraction becomes a standard of a crosslinking degree, and is computed with the following method.
That is, an adhesive sheet (not provided with a separator) obtained as described below is wrapped in a 200 mesh SUS wire mesh, immersed in toluene at 23 ° C. for 24 hours, and the insoluble adhesive component remaining in the wire mesh The weight percentage is taken as the gel fraction. However, the weight of the substrate is subtracted.

  The thickness of the pressure-sensitive adhesive layer to be obtained is not particularly limited, but is preferably 5 to 150 μm, particularly 8 to 80 μm, and more preferably 10 to 30 μm. If the thickness is too thin, the adhesive physical properties tend to be difficult to stabilize, and if it is too thick, adhesive residue tends to occur.

  The optical member with the pressure-sensitive adhesive layer obtained in the present invention is directly or has a release sheet, and after peeling off the release sheet, the surface of the pressure-sensitive adhesive layer is bonded to a glass substrate and used for, for example, a liquid crystal display board. It is.

  The optical member in the present invention is not particularly limited, and an optical film suitably used for an image display device such as a liquid crystal display device, an organic EL display device, or a PDP, such as a polarizing plate, a retardation plate, or an elliptical polarizing plate. , An optical compensation film, a brightness enhancement film, and those in which these are laminated, and the like. Among them, a polarizing plate is particularly effective in the present invention.

  The polarizing plate used in the present invention is usually obtained by laminating a cellulose triacetate film as a protective film on both sides of a polarizing film, and the polarizing film has an average polymerization degree of 1,500 to 10,000, saponification. A uniaxially stretched film dyed with an aqueous solution of iodine-potassium iodide or a dichroic dye (2 to 10 times, preferably 3 A draw ratio of about 7 times) is used.

  Polyvinyl alcohol resins are usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but small amounts of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins, vinyl ethers, A component copolymerizable with vinyl acetate, such as a saturated sulfonate, may be contained. Moreover, what is called polyvinyl acetal resin and polyvinyl alcohol derivatives, such as polybutyral resin, polyvinyl formal resin, etc. which reacted polyvinyl alcohol with aldehydes in presence of an acid is mentioned.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis unless otherwise specified.

[Production of polyester resin (A-1)]
In a four-necked separable flask equipped with a thermometer, a stirrer, a distillation tube and a condenser, neopentyl glycol 108.4 g (0.9 mol), 1,4-butanediol 52 g (0.5 mol), 1, 6-hexanediol 12 g (0.087 mol), trimethylolpropane 2.0 g (0.013 mol), isophthalic acid 38.4 g (0.2 mol), sebacic acid 187.2 g (0.8 mol) and tetra 0.18 g of butyl titanate is charged and heated at 150 to 260 ° C. for 210 minutes to carry out an esterification reaction, then the pressure of the reaction system is gradually decreased to 133 Pa after 30 minutes, and further reacted for 270 minutes while continuing to reduce the pressure. It was. The obtained polyester resin has a weight average molecular weight of 75,000, a number average molecular weight of 30000, a dispersity of 2.5, a hydroxyl value of 5.0 KOHmg / g, an acid value of 0.4 KOHmg / g, and a glass transition temperature of −49 ° C. However, it was not crystallized.

The measuring method of each physical property is as follows <weight average molecular weight, number average molecular weight>
The weight average molecular weight and the number average molecular weight are average molecular weights in terms of standard polystyrene molecular weight, and are used in high performance liquid chromatography (manufactured by Nippon Waters Co., Ltd., “Waters 2695 (Separation Module)” and “Waters 2414 (Detector)”). Column: Shodex GPC KF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plates / pack, filler material: styrene-divinylbenzene copolymer, The particle size was measured by using three filler particles having a particle diameter of 10 μm.

<Dispersity>
It was calculated from the weight average molecular weight and the number average molecular weight.

<Glass transition temperature>
The test piece is heated and cooled from room temperature at a rate of 10 ° C./min, the calorific value is measured with a differential scanning calorimeter, two extension lines are drawn on the endothermic curve or exothermic curve, and 1 between the extension lines. The temperature at the intersection of the / 2 line and the endothermic curve or exothermic curve was taken as the glass transition temperature.

[Acrylic resin (A)]
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 1 part of 2-hydroxyethyl acrylate (a1), 98.5 parts of butyl acrylate (a2), acrylic acid ( a3) 0.5 part, 85 parts of ethyl acetate and 45 parts of acetone were added, and after heating to reflux, 0.03 part of azobisisobutyronitrile (AIBN) was added as a polymerization initiator, and the mixture was refluxed at ethyl acetate for 3 hours. After the reaction, the reaction mixture was diluted with ethyl acetate, and the acrylic resin (a) solution (weight average molecular weight (Mw) 1,650,000, dispersity (Mw / Mn) 3.4, glass transition temperature -53 ° C., solid content 18%, A viscosity of 8000 mPa · s (25 ° C.)) was obtained.

[Production of unsaturated group-containing compound (B-1)]
In a four-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 19.2 parts of isophorone diisocyanate (IPDI), 0.05 part of di-t-butylhydroxyphenol, dibutyltin dilaurate 0.02 part was charged, and at 50 ° C. or less, 80.8 parts of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Kyoeisha Chemical Co., Ltd., Light Acrylate PE-3A, hydroxyl value 120 mgKOH / g) at 70 ° C. The reaction was continued to obtain an unsaturated group-containing compound (B-1). The weight average molecular weight of the unsaturated group-containing compound (B-1) was 3,500.

[Production of unsaturated group-containing compound (B-2)]
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 6.6 parts of isophorone diisocyanate (IPDI), 93.4 parts of dipentaerythritol pentaacrylate, di-t- 0.03 part of butylhydroxyphenol and 0.02 part of dibutyltin dilaurate were charged, and the reaction was continued at 50 ° C. to obtain an unsaturated group-containing compound (B-2). The weight average molecular weight of the unsaturated group-containing compound (B-2) was 1500.

[Crosslinking agent (C)]
The following were prepared as a crosslinking agent (C-1).
-50% butyl acetate solution of tolylene diisocyanate trimer (manufactured by Nippon Polyurethane, “Coronate 2030”)

[Polymerization initiator (D)]
The following were prepared as the photopolymerization initiator (D-1).
A mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone in a mass ratio of 1: 1 (Ciba Specialty Chemicals, “Irgacure 500”)

[Silane coupling agent (E)]
The following were prepared as a silane coupling agent (E-1).
γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., “KBM403”)

Example 1
A resin composition [I] solution (diluted with ethyl acetate to a viscosity of 1000 to 10000 mPa · s / 25 ° C.) was prepared with the composition shown in Table 1. The obtained resin composition [I] solution was applied to a polyester release sheet so that the thickness after drying was 25 μm, dried at 90 ° C. for 3 minutes, and then the resin composition [I] layer side was formed. Transfer onto a polarizing plate (thickness: 190 μm), and perform ultraviolet irradiation at 600 mW / cm ² and 240 mJ / cm ² with an electrodeless lamp [LH6UV lamp H bulb (effective irradiation width 150 mm × 1 row)] manufactured by Fusion, 23 ° C., 65% R.D. H. The film was aged for 14 days to obtain a polarizing plate with an adhesive layer.

  The polarizing plate was laminated with a cellulose triacetate film having a thickness of 80 μm on both sides of a 30 μm-thick polyvinyl alcohol polarizing film (average polymerization degree 1700, average saponification degree 99 mol%, iodine staining, 4-fold stretching). A polarizing plate (inclined in the direction of the stretching axis of the polyvinyl alcohol polarizing film by 45 degrees and cut into 100 mm × 100 mm) was used.

  Moreover, the sample for gel fraction measurement was obtained by the method similar to the above using the polyethylene terephthalate film (thickness 38 micrometers) instead of the polarizing plate.

<Gel fraction>
After cutting the obtained sample to 40 × 40 mm, the release sheet is peeled off and the pressure-sensitive adhesive layer side is bonded to a 50 × 100 mm SUS mesh sheet (200 mesh), and then to the longitudinal direction of the SUS mesh sheet. The sample was wrapped from the center and wrapped in a sample, and then the gel fraction was measured by the change in weight when immersed in a sealed container containing 250 g of toluene.

Examples 2-7 and Comparative Examples 1 and 2
The same operation as in Example 1 was performed with the blending composition shown in Table 1 to obtain a polarizing plate with an adhesive layer.

  Next, the release sheet of the obtained polarizing plate with the pressure-sensitive adhesive layer is peeled off, and the pressure-sensitive adhesive layer side is pressed against a non-alkali glass plate (Corning Corporation, “Corning 1737”) to obtain the polarizing plate and the glass plate. Then, autoclaving (50 ° C., 0.5 MPa, 20 minutes) was performed, and thereafter, foaming, peeling, and light leakage phenomenon were evaluated in the following durability test. The evaluation criteria are as follows. The evaluation results are shown in Table 2.

〔An endurance test〕
(1) Heat resistance test 80 ° C., 100 hour durability test (2) Heat cycle test Over 100 hours, repeated durability test switching between −40 ° C. and 85 ° C. every 30 minutes

〔Evaluation criteria〕
(Foam)
○ ... No foaming △ ... Slight foaming is observed × ... Many foaming is observed (peeling)
○ ・ ・ ・ No peeling or peeling less than 0.5mm, or generation of ukiato △ ・ ・ ・ Peeling less than 1mm or generation of ukiato × ・ ・ ・ Peeling of 1mm or more, or generation of ukiato (light leakage)
○ ・ ・ ・ No or almost no light leakage △ ・ ・ ・ Slight leakage occurred × ・ ・ ・ Large light leakage on 4 sides

From the above results, in Examples 1 to 6 containing the polyester-based resin (A) and the unsaturated group-containing compound (B), all of them are excellent in light leakage resistance, but a comparative example using an acrylic resin. 1 indicates that the light leakage resistance is insufficient.
Moreover, it turns out that durability is clearly inferior in the adhesive of the comparative example 2 which does not use unsaturated resin together using only a polyester-type resin, and it is difficult to use it for an optical member use.
From the above, the polyester-based pressure-sensitive adhesive of the present invention is very useful as a pressure-sensitive adhesive for optical members.

  The pressure-sensitive adhesive for optical members of the present invention is excellent in adhesiveness between the optical laminate and the glass substrate even under repeated high-temperature environments and low-temperature to high-temperature environmental changes, and foams between the pressure-sensitive adhesive layer and the glass substrate. In addition, since the light leakage phenomenon caused by the contraction of the optical film can be suppressed, a liquid crystal display panel having excellent durability can be obtained, which is very useful.

Claims (8)

  A pressure-sensitive adhesive for optical members, wherein the resin composition [I] containing the polyester resin (A) and the unsaturated group-containing compound (B) is crosslinked by light and / or heat.   The pressure-sensitive adhesive for optical members according to claim 1, wherein the unsaturated group-containing compound (B) is a compound having 3 or more unsaturated groups.   The pressure-sensitive adhesive for optical members according to claim 1 or 2, wherein the resin composition [I] contains a polymerization initiator (C).   The pressure-sensitive adhesive for optical members according to any one of claims 1 to 3, wherein the resin composition [I] further contains a crosslinking agent (D) and is crosslinked by the crosslinking agent.   An optical member is a polarizing plate, The adhesive for optical members in any one of Claims 1-4 characterized by the above-mentioned.   An optical member with an adhesive layer, wherein the adhesive for optical members according to claim 1 is laminated on an optical member.   A pressure-sensitive adhesive composition for optical and / or heat-crosslinking optical members, comprising a resin composition [I] containing a polyester resin (A) and an unsaturated group-containing compound (B).   The pressure-sensitive adhesive composition for optical and / or heat-crosslinking optical members according to claim 7, wherein the unsaturated group-containing compound (B) is a compound having 3 or more unsaturated groups.