KR20150093120A - Uv-curable adhesive composition for optical use, cured layer thereof and optical member - Google Patents

Abstract

The present invention provides a UV-curable adhesive composition which can solve problems such as poor adhesion, bubble mixing, poor durability, etc. shown in a conventional adhesive used in a multi-layered optical member configured by binding a variety materials. The present invention uses the UV-curable adhesive composition for optical use, comprising: at least one among a multi-functional polyurethane(meth)acrylate (A) obtained by reacting a (meth)acrylate containing hydrogenated a polybutadiene polyol, an aliphatic polyisocyanate and an isocyanato group; a polyurethane (B1) obtained by reacting a hydrogenated polybutadiene polyol, and an aliphatic polyisocyanate; and a hydrogenated polybutadiene polyol (B2) [(B) is a combination of (B1) and (B2)]; a monofunctional (meth)acrylate (C) having an alkyl group having eight or more carbon atoms; and a photo-polymerization initiator (D) wherein a solvent content is less than 1 wt%, viscosity is 100 to 10,000mPa·s at 25°C, and a Gardner color number is 1 or less.

Description

TECHNICAL FIELD [0001] The present invention relates to an ultraviolet curable adhesive composition for optical use, a cured layer and an optical member,

The present invention relates to an ultraviolet curable adhesive composition for optical, a cured layer and an optical member. More particularly, the present invention relates to an optical adhesive composition, which is very suitable for bonding optical members and components in various optical devices, a cured layer made of the composition, and an optical member including the cured layer.

Optical adhesives used for bonding optical components and members in optical instruments and the like are required not only to have excellent adhesive strength but also to excel in various performances required for optical applications such as durability and visible light transmittance. For example, an adhesive used for a display panel or the like in an image display apparatus such as a liquid crystal display or an electronic paper is required to have high adhesion and durability in addition to light resistance and heat resistance. Particularly, when the adhesive itself is used as a light transmitting medium, it is required to have an adhesive force capable of withstanding vibration or impact, and a durability that does not lower the adhesive force due to moisture or light, even when used as a thin film, in addition to excellent visible light transmittance.

In recent years, there has been a growing demand for thinner and lighter optical members, so that the ratio of use of resin materials is increasing in place of conventional inorganic materials such as glass and metal as respective members constituting the display device. For this reason, in consideration of the heat resistance of such a resin member, development of an adhesive using the curing type (for example, photo-curing or low-temperature thermal curing) that does not require high temperature heating and having the above- .

Further, as an ultraviolet curable adhesive for optical use, for example, an energy ray curable liquid pressure sensitive adhesive composition comprising a specific urethane (meth) acrylate and a specific silicone oil has been disclosed (see Patent Document 1). However, the adhesive layer obtained from such a pressure-sensitive adhesive composition can not necessarily satisfy the above-mentioned demand characteristics, and there is room for improvement.

Japanese Patent Application Laid-Open No. 2013-64075

It is an object of the present invention to provide an ultraviolet curable adhesive composition capable of solving the problems (adhesion defects, bubble entanglement, durability defects, etc.) seen in conventional adhesives used for optical members having a multilayer structure formed by bonding various materials The purpose.

The present inventors have intensively studied the composition and composition of the adhesive in view of the above problems and found that the problems can be solved by an ultraviolet curable adhesive composition satisfying specific conditions, and thus the present invention has been accomplished.

That is, the present invention relates to a polyfunctional polyurethane (meth) acrylate (A) obtained by reacting a hydrogenated polybutadiene polyol, an aliphatic polyisocyanate and an isocyanato group-containing (meth) acrylate, a hydrogenated polybutadiene polyol, (B1) and a hydrogenated polybutadiene polyol (B2) (also, (B1) and (B2) are referred to as (B) hereinafter) obtained by reacting a polyisocyanate with a polyisocyanate (C) and a photopolymerization initiator (D), wherein the solvent content is less than 1 wt%, the viscosity at 25 DEG C is 100 to 10,000 mPa s, the Gardner color number is 1 or less And an ultraviolet curable adhesive composition for optical use.

The present invention also relates to an ultraviolet-curing adhesive layer for optical properties, which is obtained by ultraviolet curing the above-mentioned ultraviolet-curing adhesive composition for optical use.

Further, the present invention relates to an optical member comprising the above-mentioned ultraviolet-curing adhesive layer for optical.

INDUSTRIAL APPLICABILITY The present invention can be widely used as an ultraviolet curable adhesive for optical applications applied to a display panel of a multi-layer structure in a digital display device. For example, in the case of employing a touch panel, a transparent plate and a transparent plate on which a transparent electrode is formed in a capacitive touch panel or a case in which a transparent plate and an icon sheet In the case of bonding, the adhesive layer is excellent in coating property and can proceed the bonding operation without bubbles. Further, the adhesive layer obtained by ultraviolet curing has excellent durability without coloring and transparency, excellent visible light transmittance, Can be exercised.

The ultraviolet curable adhesive composition for optical use of the present invention (hereinafter referred to as " the composition ") of the present invention comprises the polyfunctional polyurethane (meth) acrylate (A)

(B1) and the hydrogenated polybutadiene polyol (B1) (hereinafter referred to as component (B1)) and the hydrogenated polybutadiene polyol (hereinafter referred to as component (B2) (Hereinafter referred to as " component "),

(C) (hereinafter, referred to as component (C)) having an alkyl group having a carbon number of 8 or more and a monofunctional (meth)

And a photopolymerization initiator (D) (hereinafter referred to as component (D)),

The solvent content is less than 1 wt%, the viscosity at 25 DEG C is 100 to 10,000 mPa s, and the Gardner color number is 1 or less.

In the present specification, the ultraviolet ray hardening layer obtained from the present composition is referred to as the present hardening layer, and the optical member including the present hardening layer is referred to as the present member.

If the content of the solvent in the above conditions exceeds 1% by weight, the resulting composition tends to foam when the composition is cured by ultraviolet rays, and bubbles are likely to be formed in the cured layer, which may deteriorate the value of the application member or the final product.

If the viscosity of the composition obtained in the above-mentioned conditions is outside the range of 100 to 10,000 mPa · s, the coating workability under normal temperature and normal pressure tends to be lowered.

If the color tone of the composition obtained in the above-mentioned conditions exceeds the Gardner color number of 1, the color tone and transparency of the obtained cured layer tend to be lowered, which may restrict application in optical applications.

(Meth) acrylate having an isocyanato group (hereinafter referred to as (meth) acrylate (hereinafter referred to as (meth) acrylate) having a hydrogenated polybutadiene polyol (hereinafter referred to as component (a1)), an aliphatic polyisocyanate (component (a3)).

The component (a1) is a polyol obtained by hydrogenating a polybutadiene polyol. By using the component (a1) which is a hydrogenation additive, the present composition and the present cured layer excellent in adhesive strength and durability can be obtained. The molecular weight of the component (a1) is not particularly limited, but is preferably 1,000 to 5,000 from the viewpoint of the adhesive strength. The iodine value of the component (a1) is not particularly limited, but it is usually 50 or less, preferably 25 or less in view of durability, and the hydroxyl value is usually in the range of 10 to 200 and preferably 20 to 100 in terms of adhesiveness . NISSO-PB GI-1000 "," NISSO-PB GI-2000 "," NISSO-PB GI-3000 ", and CRAY VALLEY (manufactured by Nippon Soda Co., Krasol HLBH-P2000 " and " Krasol HLBH-P3000 ".

Examples of the component (a2) include dicyclohexylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, etc., and their 2- to 6-mer compounds, and these may be used alone or in combination . By using the component (a2), the present cured layer having excellent adhesive strength and durability can be provided.

Examples of the component (a3) include 2-isocyanatoethyl (meth) acrylate and 1,1- (bishacryloyloxymethyl) ethyl isocyanate. These may be used alone or in combination .

The component (A) can be produced by reacting the component (a1) with the component (a2) to obtain a hydroxyl-terminated polyurethane, and then reacting the hydroxyl-terminated polyurethane with the component (a3). In the production of the component (A), a method in which the component (a1), the component (a2) and the component (a3) are subjected to a batch reaction can also be employed. However, electrons are employed in that the weight average molecular weight of the component .

The weight average molecular weight of the component (A) (in terms of polystyrene as determined by gel permeation chromatography) is not particularly limited, but from the viewpoint of the adhesiveness and durability of the present composition, the present cured layer, .

The average number of functional groups of the component (A) is not particularly limited, but is preferably 1.5 to 3.0, and more preferably 1.8 to 2.2 in view of the durability of the resulting cured layer. The average functional group number means the average number of (meth) acryloyl groups present in one molecule of the component (A).

The amount of the component (A) to be used is preferably 10 to 50% by weight, more preferably 25 to 35% by weight, based on 100 parts by weight of the composition. (A) is 10% by weight or more, the adhesion and durability of the present composition, the present cured layer can be improved, and the handling property of the composition can be improved by setting the ratio of the component (A) .

(B) is at least one of the components (B1) and (B2). (B1) is the same compound as the intermediate of the component (A), and the component (B2) corresponds to the component (a1).

The amount of the component (B) to be used is preferably 10 to 60% by weight, more preferably 25 to 35% by weight, based on 100 parts by weight of the composition. (B) is at least 10% by weight, the adhesion and durability of the present composition, the present cured layer can be improved, and the proportion of the component (B) is at most 60% .

Specific examples of the component (C) include, but are not limited to, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) (Meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (Meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, (Meth) acrylate having a cyclic structure such as adamantane (meth) acrylate, and the like.

In addition, it is also possible to use at least one monomer selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, The use of a monofunctional (meth) acrylate having an alkyl group of less than 8 carbon atoms such as t-butyl (meth) acrylate or n-pentyl (meth) acrylate deteriorates adhesiveness, odor and skin irritation of the obtained adhesive composition There is a tendency.

The amount of the component (C) to be used is preferably in the range of 15 to 74.9% by weight, more preferably in the range of 30 to 70% by weight, based on 100 parts by weight of the composition. The handling property of the composition can be improved by setting the proportion of the component (C) to 15% by weight or more, and by setting the proportion of the component (C) to 74.9% by weight or less, the curability of the composition can be improved.

(D) is a photopolymerization initiator which is decomposed by ultraviolet irradiation to generate radicals, various known ones can be used without particular limitation. Specific examples thereof include photopolymerization initiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds and oxime ester compounds, and photosensitizers such as amines and quinones. Methyl-1-phenyl-propan-1-one, 1, 2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl phenyl ketone, 2-methyl-1-propan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy- Methyl-1- (4-methylthiophenyl) -2 -morpholinopropan-1-one, 2 - (dimethylamino) -2 - [(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenylphosphine Oxide, bis (2,4,6-tri Methyl benzoyl) phenyl phosphine oxide, bis (η ⁵ -2, 4- cyclopentadiene-1-yl) -bis (2, 6-difluoro--3- (1H- pyrrol-1-yl) -phenyl ) Titanium, 1, 2-octanedione 1- [4- (phenylthio) -2- (o-benzoyloxime)], ethanone 1- [ 3-yl] -1- (o-acetyloxime), and the like may be used singly or two or more of them may be used in combination. Among these, 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide are very suitable because they can further improve the curability of the present composition.

The amount of the component (D) to be used is preferably 0.1 to 10% by weight, more preferably 0.2 to 5% by weight in 100 parts by weight of the composition. When the ratio of the component (D) is 0.1% by weight or more, unevenness of the curing polymerization by ultraviolet irradiation can be prevented. When the content is 10% by weight or less, the generation of odor attributable to decomposition products of the component (D) , And it is also possible to prevent the coloration of the cured layer.

The preparation of the composition is carried out by mixing the components (A) to (D) at a desired ratio. The mixing method and the order of addition of the respective components are not particularly limited.

In addition, various kinds of polyfunctional monomers and tackifiers can be added to the composition within the range that does not impair the effects of the present invention, if necessary.

Specific examples of the multifunctional monomer include 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9- Di (meth) acrylate having an alicyclic structure such as cyclohexanedimethanol di (meth) acrylate and tricyclodecanediyl (meth) acrylate, and the like; Di (meth) acrylate having an aromatic structure such as bisphenol A ethylene oxide modified di (meth) acrylate and bisphenol F ethylene oxide modified di (meth) acrylate, trimethylolpropane tri (meth) acrylate, isocyanuric acid Ethylene oxide modified tri (meth) acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate Agent, may be mentioned dipentaerythritol hexaacrylate, etc. of a trifunctional or more polyfunctional (meth) acrylate.

Specific examples of the tackifier include petroleum resin, phenol resin, xylene resin, coumarone resin, rosin resin, terpene resin, hydrogenated petroleum resin, hydrogenated rosin resin, hydrogen terpene resin and the like. Among them, the color tone is preferably 1 or less of the Gardner color number. For example, a hydrogenated petroleum resin or a hydrogenated rosin resin having a color tone of Gardner color 1 or less can be cited. These hydrogenated resins generally have a Gardner color number of 1 or less and are excellent in transparency. Therefore, the hydrogenated resin can improve the transparency of the present composition and the present cured layer, has little polymerization inhibition during ultraviolet curing, Is advantageous. The softening point and the aniline point (based on JIS K 2256) of these tackifiers are not particularly limited, but considering the transparency of the resulting composition, compatibility with other components in the composition, and the like, Deg.] To 120 [deg.] C, and the aniline point is preferably about 50 to 100 [deg.] C. Examples of a commercially available tackifier having the above-mentioned hue, softening point and aniline point include ARKON M-90, M-100, M-115 manufactured by Arakawa Chemical Industry Co., Ltd., Mab S-100, Escorez 5690 manufactured by Exxon Mobil Corp., Rigalite 5100 manufactured by Eastman Chemical Co., Ltd., and the like.

In addition, various additives can be contained in the composition insofar as the effects of the present invention are not impaired, if necessary. Additives such as a surface modifier, a surfactant, an ultraviolet absorber, an antioxidant, an inorganic filler, a silane coupling agent, a colloidal silica, a defoaming agent, a wetting agent, a rust inhibitor, Can be contained.

The composition of the present invention can be applied to a variety of optical devices such as a display panel and a bright plate or an icon sheet, a transparent substrate in which a transparent electrode is formed on a touch panel and a transparent plate, And the like. Examples of the material of the member include polyethylene terephthalate, polycarbonate, glass, acrylic resin and the like. As the display member, a display device such as a liquid crystal display in which a polarizing plate is attached to a glass, an EL display EL illumination, an electronic paper or a plasma display can be given. As the optically functional material, an acrylic plate (which may be subjected to one-side or both-side hard coat treatment or antireflection coating treatment) for the purpose of improving visibility and preventing breakage of the display element from external impact, polycarbonate plate, polyethylene terephthalate plate, polyethylene naphthalate A transparent plastic plate such as a plate, a tempered glass (may have a scattering prevention film attached thereto), and a touch panel input sensor.

Examples of ultraviolet light sources used for curing the composition include ultraviolet irradiation devices having a xenon lamp, a high-pressure mercury lamp, and a metal halide lamp. The light amount, the light source, the conveying speed, and other conditions may be suitably adjusted, the light amount is usually about 80 to 160 W / cm, and the conveying speed is usually about 5 to 50 m / min.

The thickness of the present cured layer is not particularly limited, but is usually about 10 to 1000 mu m, preferably 25 to 500 mu m. By setting the thickness of the thick film in this range, it is possible to improve the impact resistance of the optical member and the module, and to absorb the printing step difference on the surface, so that it can be used as the protective film on the front face.

Example

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples. In the examples, "% " and " part " mean "% by weight "

≪ Synthesis of component (A) >

Synthetic example  One

Synthesis of Component (A-1)

910 parts of a hydrogenated polybutadiene polyol having a weight average molecular weight of 4,000 (NISSO-PB GI-3000, manufactured by Nippon Soda Co., Ltd.), 81 parts of isophorone diisocyanate and 81 parts of tin octylate , And the mixture was heated to 80 ° C. and maintained at that temperature for 2 hours. NCO measurement confirmed completion of the reaction to obtain a hydroxyl-terminated urethane oligomer as an intermediate. Next, 19 parts of 2-isocyanatoethyl methacrylate was added, the mixture was kept at 80 占 폚 for 2 hours, and the completion of the reaction was confirmed by NCO measurement to obtain a polyurethane methacrylate oligomer having a weight average molecular weight of 36,000 and an average number of functional groups of 2.0 Hereinafter referred to as (A-1) component). The weight average molecular weight was measured in terms of polystyrene by gel permeation chromatography, and the measurement conditions were as follows (measuring apparatus main body (product name: HLC-8220 GPC, manufactured by Tosoh Corporation), column (product name: TSKGel G1000H ", " TSKGel G2000H ", manufactured by Tosoh Corporation) and developing solvent (tetrahydrofuran)]. (Hereinafter the same)

Synthetic example  2

(A-2) Synthesis of components

925 parts of the same hydrogenated polybutadiene polyol as used in Synthesis Example 1, 51 parts of isophorone diisocyanate and 0.2 part of tin octylate were added to the same reaction apparatus as in Synthesis Example 1, and the temperature was raised to 80 DEG C and maintained at that temperature for 2 hours. To confirm completion of the reaction to obtain a hydroxyl-terminated urethane oligomer as an intermediate. Next, 24 parts of 2-isocyanatoethyl methacrylate was added, the mixture was kept at 80 占 폚 for 2 hours, and the completion of the reaction was confirmed by NCO measurement to obtain a polyurethane methacrylate oligomer having a weight average molecular weight of 21,000 and an average number of functional groups of 2.0 Hereinafter referred to as (A-2) component).

Synthetic example  3

(A-3) Synthesis of components

917 parts of the same hydrogenated polybutadiene polyol as used in Synthesis Example 1, 67 parts of dicyclohexylmethane-4, 4'-diisocyanate and 0.2 part of tin octylate were added to the same reactor as in Synthesis Example 1, And the mixture was kept warm for 2 hours. After completion of the reaction was confirmed by NCO measurement to obtain a hydroxyl-terminated urethane oligomer as an intermediate. Next, 16 parts of 2-isocyanatoethyl methacrylate was added, the mixture was kept at 80 占 폚 for 2 hours, and the completion of the reaction was confirmed by NCO measurement to obtain a polyurethane methacrylate oligomer having a weight average molecular weight of 21,000 and an average number of functional groups of 2.0 Hereinafter referred to as (A-3) component).

compare Synthetic example  One

Synthesis of Component (E-1)

955 parts of polypropylene glycol having a weight average molecular weight of 4,000 (trade name: PREMINOL 5001F, manufactured by Asahi Glass Co., Ltd.), 34 parts of isophorone diisocyanate and 0.2 parts of tin octylate were added to the same reactor as in Synthesis Example 1, And kept at that temperature for 2 hours. After confirming the completion of the reaction by NCO measurement, the hydroxyl group-terminated urethane oligomer as an intermediate was obtained. Next, 19 parts of 2-isocyanatoethyl methacrylate was added, the mixture was kept at 80 占 폚 for 2 hours, and the completion of the reaction was confirmed by NCO measurement to obtain a polyurethane methacrylate oligomer having a weight average molecular weight of 36,000 and an average number of functional groups of 2.0 Hereinafter referred to as (E-1) component).

≪ Synthesis of Component (B) >

Synthetic example  4

Synthesis of Component (B-1)

964 parts of the same hydrogenated polybutadiene polyol as used in Synthesis Example 1, 36 parts of isophorone diisocyanate, and 0.2 part of tin octylate were added to the same reaction apparatus as in Synthesis Example 1, and the temperature was raised to 80 DEG C and maintained at that temperature for 2 hours. To obtain a polyurethane having a weight average molecular weight of 9,900 (hereinafter referred to as (B-1) component).

Synthetic example  5

Synthesis of Component (B-2)

942 parts of the same hydrogenated polybutadiene polyol as used in Synthesis Example 1, 58 parts of isophorone diisocyanate, and 0.2 part of tin octylate were added to the same reactor as in Synthesis Example 1, and the mixture was heated to 80 DEG C and maintained at this temperature for 2 hours. To obtain a polyurethane having a weight average molecular weight of 34,000 (hereinafter referred to as (B-2) component).

compare Synthetic example  2

Synthesis of Component (E-2)

955 parts of the same polypropylene glycol, 34 parts of isophorone diisocyanate and 0.2 part of tin octylate as used in Comparative Synthesis Example 1 were added to the same reactor as in Synthesis Example 1, and the mixture was heated to 80 DEG C and maintained at this temperature for 2 hours. (Hereinafter referred to as (E-2) component) having a weight average molecular weight of 34,000 was obtained.

≪ Preparation of adhesive composition >

Example  One

27 parts of a hydrogenated polybutadiene polyol (trade name: NISSO-PB GI-1000, manufactured by Nippon Soda Co., Ltd., hereinafter referred to as component (B-3)) as a component (B) , 10 parts of isobornyl acrylate (trade name: IBXA, hereinafter referred to as component (C-1)), 2 parts of ethylhexyl acrylate (manufactured by Mitsubishi Chemical Corporation, Manufactured by BASF Japan Co., Ltd .; trade name: Irgacure 184 (trade name, manufactured by BASF Japan)) as a component (D) , Hereinafter referred to as component (D-1)) were all blended in pure form to prepare an adhesive composition (see Table 1). The Gardner color number, viscosity, solvent content and compatibility of the composition were evaluated, and the results are shown in Table 2 (the same shall apply hereinafter).

Example  2 to 7

An adhesive composition was prepared in the same manner as in Example 1 except that the kinds of the components were changed as shown in Table 1.

Comparative Example  One

Except that 57 parts of the component (A-1) and 10 parts of the component (C-1), 30 parts of the component (C-2) and 3 parts of the component (D-1) An adhesive composition was prepared in the same manner as in Example 1 (see Table 1, the same applies hereinafter).

Comparative Example  2

Except that 57 parts of the component (A-2) and 30 parts of the component (C-2) and 3 parts of the component (D-1) To prepare an adhesive composition.

Comparative Example  3

57 parts of the component (B-1), 10 parts of the component (C-1), 30 parts of the component (C-2) and 3 parts of the component (D-1) To prepare an adhesive composition.

Comparative Example  4

57 parts of the component (B-2), 10 parts of the component (C-1), 30 parts of the component (C-2) and 3 parts of the component (D-1) To prepare an adhesive composition.

Comparative Example  5

57 parts of the component (B-3), 10 parts of the component (C-1), 30 parts of the component (C-2) and 3 parts of the component (D-1) To prepare an adhesive composition.

Comparative Example  6

(Butyl acrylate, hereinafter referred to as (F-1) component) manufactured by Mitsubishi Chemical Corporation) was used in place of 30 parts of the component (A-1), 27 parts of the component (B- And (D-1) were all blended in terms of pure fractions to prepare an adhesive composition.

Comparative Example  7

Except that 30 parts of the component (E-1), 27 parts of the component (E-2), 10 parts of the component (C-1), 30 parts of the component (C- -1) component were all blended in terms of pure fractions to prepare an adhesive composition.

(B-3): hydrogenated polybutadiene polyol

        (Trade name: NISSO-PB GI-1000, manufactured by Japan Soda Co., Ltd.)

(B-4): hydrogenated polybutadiene polyol

        (Trade name: NISSO-PB GI-3000, manufactured by Japan Soda Co., Ltd.)

(C-1): isobornyl acrylate (trade name: IBXA, manufactured by Osaka Organic Chemical Industry Co., Ltd.)

(C-2): 2-ethylhexyl acrylate (manufactured by Mitsubishi Chemical Corporation, trade name "2-ethylhexyl acrylate")

(C-3): dicyclopentenyloxyethyl acrylate (manufactured by Hitachi Chemical Co., Ltd., trade name: Pankril FA512AS)

(D-1): 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by BASF Japan)

(F-1): butyl acrylate (manufactured by Mitsubishi Chemical Corporation, trade name "butyl acrylate")

<Gardner color number>

The Gardner color number was measured according to JIS K5600.

<Viscosity>

The viscosity (mPa s) was measured by an E-type viscometer (TVE-10, manufactured by TOKI INDUSTRY CO., LTD.) At 25 캜 for 5 minutes.

&Lt; Solvent content rate &gt;

The solvent content was measured using a gas chromatographic apparatus under the following conditions.

(Analyzer)

GC: Agilent 6850 (manufactured by Agilent Technologies, Inc.)

(GC measurement conditions)

GC column: HP-1 (manufactured by Agilent Technologies, Inc.)

Column temperature: 50 占 폚 (10 min)? 10 占 폚 / min? 300 占 폚 (10 min)

Column flow rate: 2.0 ml / min

Carrier gas: Helium

Injection method: Split (50: 1)

Detection temperature: 300 ° C

<Compatibility>

The compatibility was evaluated by observing the obtained adhesive composition by the following criteria.

○: uniformly completely transparent

X: Confirmation of whitening, sediment, insoluble material or liquid phase separation

&Lt; Preparation of test piece &

A composition according to Example 1 was cured by attaching the composition according to Example 1 to a thickness of 100 mu m between a glass plate having a thickness of 0.7 mm and a glass plate having a thickness of 0.7 mm and passing under a metal halide lamp (1000 mJ / cm ² ) three times to prepare a test piece . Test pieces were similarly prepared for the compositions of Examples 2 to 7 and Comparative Examples 1 to 7.

[Various Evaluation of Adhesive Layer]

Evaluation example  1 to 7, comparison Evaluation example  1 to 7

The following tests were carried out using the above test pieces.

<Haze value, transmittance>

The haze value and transmittance of the test piece were measured in accordance with JIS K 5600 using a color haze meter (manufactured by Murakami Color Research Laboratory). The results are shown in Table 3. Each haze value is a value including the haze value of the base glass.

<Heat resistance test>

In the heat resistance test, the test piece was allowed to stand for 500 hours in a constant-temperature and constant-humidity chamber at a temperature of 85 DEG C, and then the haze value and the transmittance were measured in the same manner as described above. The results are shown in Table 3. Each haze value is a value including the haze value of the base glass.

The durability was evaluated according to the following criteria.

○: No peeling, No leakage of adhesive layer, No bubble and breakage

×: peeling, adhesion layer leaching, bubble and breakage

&Lt; Heat and humidity test &

In the wet heat resistance test, the test piece was allowed to stand for 500 hours in a constant temperature and humidity chamber at a temperature of 85 DEG C and a humidity of 85%, and then the haze value and the transmittance were measured in the same manner as described above. The results are shown in Table 4. Each haze value is a value including the haze value of the base glass.

The durability was evaluated according to the following criteria.

○: No peeling, No leakage of adhesive layer, No bubble and breakage

×: peeling, adhesion layer leaching, bubble and breakage

Claims (6)

A polyfunctional polyurethane (meth) acrylate (A) obtained by reacting a (meth) acrylate having a hydrogenated polybutadiene polyol, an aliphatic polyisocyanate and an isocyanato group,
(B1) obtained by reacting a hydrogenated polybutadiene polyol and an aliphatic polyisocyanate, and a hydrogenated polybutadiene polyol (B2) [(B1) and (B2) and,
(C) a monofunctional (meth) acrylate having an alkyl group having a carbon number of 8 or more,
And a photopolymerization initiator (D)
And a solvent content of less than 1% by weight, a viscosity at 25 占 폚 of 100 to 10,000 mPa 占 퐏, and a Gardner color number of 1 or less. The method according to claim 1,
Wherein the component (A) has a weight average molecular weight (polystyrene equivalent value determined by gel permeation chromatography) of 10,000 to 100,000. 3. The method according to claim 1 or 2,
Wherein the average functional group number of the component (A) is 1.5 to 3.0. 4. The method according to any one of claims 1 to 3,
Each of the components (A), (B), (C) and (D) in an amount of 10 to 50 wt%, 5 to 30 wt%, 5 to 74.9 wt%, and 0.1 to 10 wt% By weight based on the total weight of the composition. An ultraviolet curing adhesive layer for optical use characterized by being obtained by ultraviolet curing the optical ultraviolet curable adhesive composition according to any one of claims 1 to 4. An optical member comprising the optical ultraviolet curing adhesive layer according to claim 5.