JP6391195B2 - UV curable resin composition, cured product and article - Google Patents

Description

  The present invention relates to an ultraviolet curable resin composition useful for bonding optically transparent members.

  In recent years, display devices that enable screen input by bonding a touch panel to a display screen of a display device such as a liquid crystal display, a plasma display, or an organic EL display have been widely used. In the display device, a glass plate or a resin film on which a transparent electrode is formed is laminated on the display screen so that the transparent electrode faces each other, and the touch surface of the touch panel is made of glass or It has a structure in which a transparent protective plate made of resin is laminated. Moreover, in the display apparatus which does not have a touch panel, it has the structure which laminated | stacked the transparent protective plate made from glass or resin on the display screen.

  Bonding of a glass or resin transparent protective plate on the touch surface of a glass plate or film on which a transparent electrode is formed, or bonding a transparent protective plate to a display device and its screen, or In addition, there is a technique of using a double-sided pressure-sensitive adhesive sheet for bonding a display device and a touch panel to the screen, but there is a problem that air bubbles easily enter. As a technique replacing the double-sided pressure-sensitive adhesive sheet, a technique of bonding with a photocurable resin composition has been proposed (Patent Documents 1 to 3).

  On the other hand, display devices are becoming thinner and larger screens. Therefore, for example, the transparent protective plate or the substrate of the touch panel, the glass plate for the display screen in the display device, or the resin transparent plate is becoming thinner. For this reason, when the photocurable resin composition is used for the lamination or bonding, there is a problem that the touch panel and the display screen are deformed due to the curing shrinkage of the fat composition. In addition, when both materials in the adherend are different such as glass / acrylic resin and glass / polycarbonate resin, there is a problem that the adhesive surface peels off in the moisture and heat resistance test due to the difference in thermal expansion and hygroscopicity of both materials. . In order to solve these problems, there has been a demand for a photocurable resin composition that suppresses shrinkage during curing and provides a cured product excellent in adhesion to a substrate and flexibility. However, when polyisoprene described in Patent Document 1 is used as a main component, it must be removed with an organic solvent such as heptane or hexane at the time of rework, resulting in a problem of poor reworkability. In addition, when an epoxy resin having a cycloalkane skeleton as described in Patent Document 2 is used, the flexibility is inferior, and even in a composition as described in Patent Document 3, yellowing during curing is caused. There are concerns. For this reason, none of Patent Documents 1 to 3 is satisfactory.

International Publication No. 2010/027041 JP 2010-248387 A Special table 2011-511851 gazette

  The present invention is an ultraviolet curable resin composition that is excellent in curability, has a small shrinkage at the time of curing, can provide an optically transparent adhesive that is excellent in transparency of a cured product, adhesiveness to a base material, and flexibility, and An object of the present invention is to provide an optical member obtained by using, for example, a touch panel or a display device, an electronic device incorporating them, and the like.

  As a result of intensive studies to solve the above problems, the present inventors have found an ultraviolet curable resin composition containing a compound having the structure of the following formula (1), a (meth) acrylate compound, and a photopolymerization initiator. The present inventors have found that the above-described problems can be achieved and have completed the present invention.

式中、ｎは０〜４０の整数、ｍは１０〜８０の整数、Ｒ^１およびＲ^２は、それぞれ同一であっても異なっていてもよく、炭素数１〜１８のアルキル基、炭素数２〜１８のアルケニル基、炭素数２〜１８のアルキニル基又は炭素数５〜１８のアリール基である。
（２） Ｒ^１およびＲ^２はそれぞれ独立に、炭素数１〜１０のアルキル基又は炭素数３〜１０のアルケニル基である上記（１）に記載の紫外線硬化型樹脂組成物。
（３）上記化合物（Ａ）が、ポリプロピレングリコールジアリルエーテル、ポリプロピレングリコールジメチルエーテル、ポリプロピレングリコールジブチルエーテル、ポリプロピレングリコールアリルブチルエーテル、ポリエチレングリコール−ポリプロピレングリコールジアリルエーテル、ポリエチレングリコール−ポリプロピレングリコールジブチルエーテル及びポリエチレングリコール−ポリプロピレングリコールアリルブチルエーテルからなる群から選ばれる少なくとも一つである上記（１）に記載の紫外線硬化型樹脂組成物。
（４）（メタ）アクリレート化合物（Ｂ）として、（メタ）アクリロイル基を１個有する（メタ）アクリレート化合物（Ｂ’）又は（メタ）アクリロイル基を２個有する（メタ）アクリレート化合物を含有する上記（１）〜（３）の何れか一項に記載の紫外線硬化型樹脂組成物。
（５）（メタ）アクリレート化合物（Ｂ）として、ウレタン（メタ）アクリレート（Ｄ）を含有する上記（１）〜（４）の何れか一項に記載の紫外線硬化型樹脂組成物。 That is, the present invention relates to the following (1) to (22).
(1) An ultraviolet curable resin composition containing a compound (A) having a structure represented by the following general formula (1), a (meth) acrylate compound (B) and a photopolymerization initiator (C),
Formula (1)

In the formula, n is an integer of 0 to 40, m is an integer of 10 to 80, and R ¹ and R ² may be the same or different, each having 1 to 18 carbon atoms, 2 carbon atoms An alkenyl group having 18 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, or an aryl group having 5 to 18 carbon atoms.
(2) The ultraviolet curable resin composition according to (1), wherein R ¹ and R ² are each independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 3 to 10 carbon atoms.
(3) The above compound (A) is polypropylene glycol diallyl ether, polypropylene glycol dimethyl ether, polypropylene glycol dibutyl ether, polypropylene glycol allyl butyl ether, polyethylene glycol-polypropylene glycol diallyl ether, polyethylene glycol-polypropylene glycol dibutyl ether, and polyethylene glycol-polypropylene glycol. The ultraviolet curable resin composition according to (1), which is at least one selected from the group consisting of allyl butyl ether.
(4) The (meth) acrylate compound (B), which contains a (meth) acrylate compound (B ′) having one (meth) acryloyl group or a (meth) acrylate compound having two (meth) acryloyl groups The ultraviolet curable resin composition according to any one of (1) to (3).
(5) The ultraviolet curable resin composition according to any one of (1) to (4) above, which contains urethane (meth) acrylate (D) as the (meth) acrylate compound (B).

(6) The above (1) to (5) containing the urethane (meth) acrylate (D) and the (meth) acrylate compound (B ′) having one (meth) acryloyl group as the (meth) acrylate compound (B). The ultraviolet curable resin composition as described in any one of 1).
(7) The content of the compound (A) is 10 to 60% by weight, the content of the photopolymerization initiator (C) is 0.2 to 5% by weight, and the balance is the (meth) acrylate compound (B) The ultraviolet curable resin composition according to any one of (1) to (6).
(8) As a (meth) acrylate compound (B ′) having one (meth) acryloyl group, an alkyl (meth) acrylate having 10 to 30 carbon atoms; a poly C2 to C4 alkylene glycol (meth) acrylate; a polypropylene oxide-modified nonyl At least one selected from the group consisting of phenyl (meth) acrylate; alkyl (meth) acrylate having 1 to 5 carbon atoms having a hydroxyl group; acryloylmorpholine; tetrahydrofurfuryl (meth) acrylate and dicyclopentenyloxyethyl (meth) acrylate The ultraviolet curable resin composition of Claim 6 containing this.
(9) As a (meth) acrylate compound (B ′) having one (meth) acryloyl group, lauryl (meth) acrylate, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, isostearyl (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isostearyl (meth) acrylate, 2-decyltetradecanyl (meth) acrylate The ultraviolet curable resin composition according to any one of (4) to (8), which contains at least one selected from the group consisting of:

(10) The compound (A) is polypropylene glycol diallyl ether, polypropylene glycol dimethyl ether, polypropylene glycol dibutyl ether, polypropylene glycol allyl butyl ether, polyethylene glycol-polypropylene glycol diallyl ether, polyethylene glycol-polypropylene glycol dibutyl ether, and polyethylene glycol-polypropylene glycol. Is at least one selected from the group consisting of allyl butyl ether,
As the (meth) acrylate compound (B ′) having one (meth) acryloyl group, lauryl (meth) acrylate, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meta) ) Acrylate, isostearyl (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isostearyl (meth) acrylate, 2-decyltetradecanyl (meth) acrylate Containing at least one selected from
The ultraviolet curable resin composition according to any one of (4) to (9) above.
(11) The above (meth) acrylate compound (B ′) having one (meth) acryloyl group and urethane (meth) acrylate (D), wherein m in the general formula (1) is an integer of 10 to 50 The ultraviolet curable resin composition according to any one of (1) to (10).
(12) The ultraviolet curing according to any one of the above (1) to (11), wherein the urethane (meth) acrylate (D) is a reaction product of a polyether polyol, a polyisocyanate, and a hydroxyl group-containing (meth) acrylate. Mold resin composition.

(13) The (meth) acrylate compound (B) includes a urethane (meth) acrylate (D) and a (meth) acrylate compound (B ′) having one (meth) acryloyl group, and is based on the total amount of the composition The compound (A) is 1 to 60% by weight, the urethane (meth) acrylate (D) is 20 to 80% by weight, and the (meth) acrylate compound (B ′) having one (meth) acryloyl group is 10 to 70%. The ultraviolet curable resin composition according to any one of the above (1) to (12), containing 0.2% by weight to 5% by weight and a photopolymerization initiator (C).
(14) The total content of the (meth) acrylate compound (B ′) having one (meth) acryloyl group and the urethane (meth) acrylate (D) is at least 40% by weight based on the total amount of the resin composition. The ultraviolet curable resin composition as described in said (13).
(15) The ultraviolet curable resin composition according to any one of (1) to (14), wherein the curing shrinkage ratio is 3.0% or less.
(16) (i) The above compound (A) is polypropylene glycol diallyl ether, polypropylene glycol dimethyl ether, polypropylene glycol dibutyl ether, polypropylene glycol allyl butyl ether, polyethylene glycol-polypropylene glycol diallyl ether, polyethylene glycol-polypropylene glycol dibutyl ether, and polyethylene glycol. -At least one selected from the group consisting of polypropylene glycol allyl butyl ether,
(Ii) As a (meth) acrylate compound (B ′) having one (meth) acryloyl group, lauryl (meth) acrylate, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, isostearyl (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isostearyl (meth) acrylate, 2-decyltetradecanyl (meth) acrylate Containing at least one selected from the group consisting of:
(Iii) Urethane (meth) acrylate (D) is a reaction product of polyether polyol, polyisocyanate and hydroxyl group-containing (meth) acrylate,
The ultraviolet curable resin composition according to any one of (6) to (15) above.

(17) The ultraviolet curable resin composition according to any one of (6) to (16), wherein the urethane (meth) acrylate (D) has a weight average molecular weight of 7000 to 25000.
(18) the compound (A), the general formula (1) in ^{R 1} and ^{R 2} may each be the same or different, ^{R 1} and ^{R 2} are an alkyl group or carbon number of 1 to 10 carbon atoms It is a compound that is an alkenyl group of 3 to 10, urethane (meth) acrylate (D) is a reaction product of polyether polyol, polyisocyanate, and hydroxyl group-containing (meth) acrylate, and the weight average molecular weight of the reaction product is 7000 to 25000, including (meth) acrylate compound (B) having (meth) acrylate compound (B ′) having one urethane (meth) acrylate (D) and (meth) acryloyl group as (meth) acrylate compound (B), and composition 1 to 60% by weight of the above compound (A), 20 to 80% by weight of urethane (meth) acrylate (D), ) 10 to 70% by weight of (meth) acrylate compound (B ′) having one acryloyl group, 0.2 to 5% by weight of photopolymerization initiator (C), and (meth) acryloyl group The total content of (meth) acrylate compound (B ′) and urethane (meth) acrylate (D) having one is 40 to 90% by weight based on the total amount of the composition. The ultraviolet curable resin composition as described in any one of the above.
(19) An optical member in which at least two optical base materials are bonded by a cured product layer of the ultraviolet curable resin composition according to any one of (1) to (18).
(20) A cured product obtained by irradiating the ultraviolet curable resin composition according to any one of (1) to (18) with active energy rays.
(21) A touch panel in which at least two optical substrates are bonded by a cured product layer of the ultraviolet curable resin composition according to any one of (1) to (18).
(22) A protective optical group in which a protective optical substrate or a touch panel and a display device are bonded to each other by the cured product layer of the ultraviolet curable resin composition according to any one of (1) to (18) above. A display device having a material or a touch panel.

  INDUSTRIAL APPLICABILITY According to the present invention, an ultraviolet curable resin composition that can be used as an optically transparent adhesive having excellent curability, small shrinkage during curing, transparency of a cured product, adhesion to a substrate, and excellent flexibility. An optical member bonded with a cured product layer of the resin composition can be provided.

  The ultraviolet curable resin composition of the present invention (hereinafter referred to as the resin composition of the present invention or the composition of the present invention) includes a compound (A) having a structure represented by the general formula (1), a (meth) acrylate compound ( B) and a photopolymerization initiator (C) are contained.

式中、ｎは０〜４０の整数、ｍは１０〜８０の整数を示す。Ｒ^１およびＲ^２はそれぞれ同一であっても異なっていてもよい。Ｒ^１およびＲ^２は炭素数１〜１８のアルキル基、炭素数２〜１８のアルケニル基、炭素数２〜１８のアルキニル基、又は炭素数５〜１８のアリール基である。 The resin composition of the present invention contains a compound (A) having a structure represented by the following general formula (1).
Formula (1)

In the formula, n represents an integer of 0 to 40, and m represents an integer of 10 to 80. R ¹ and R ² may be the same or different. R ¹ and R ² are an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, or an aryl group having 5 to 18 carbon atoms.

In Formula (1), as one preferable embodiment, n can be 0, or n can be 5 to 40, more preferably 10 to 30. m is preferably 20 to 80, and more preferably 30 to 70. Here, m / (m + n) is preferably 0.2 to 1 and more preferably 0 from the viewpoint of imparting adhesion to the substrate and improving compatibility with urethane (meth) acrylate. .4 to 1.
R ¹ and R ² are preferably each independently an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms, more preferably an alkyl group or carbon having 1 to 10 carbon atoms. It is an alkenyl group of several 3 to 10. More preferably, R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 3 to 5 carbon atoms. In one most preferable embodiment, n is 5 to 40, m is 10 to 40, and one of R ¹ and R ² is a butyl group and the other is an allyl group, or n is 0, In this embodiment, m is 20 to 80, and R ¹ and R ² are each independently an alkyl group having 1 to 4 carbon atoms, preferably a methyl group.

The compound (A) having the structure represented by the general formula (1) can impart the flexibility of the adhesive. As a compound (A) which has a structure shown by General formula (1), if n is an integer of 0-40 and m is the range of 10-80, it can be used without a restriction | limiting.
Specific examples of the compound (A) include, for example, polypropylene glycol diallyl ether, polypropylene glycol dimethyl ether, polypropylene glycol dibutyl ether, polypropylene glycol allyl butyl ether, polyethylene glycol-polypropylene glycol diallyl ether, polyethylene glycol-polypropylene glycol dibutyl ether, polyethylene glycol. -Polypropylene glycol allyl butyl ether.

The compound (A) can also be easily obtained as a commercial product. For example, it can be obtained as polyethylene glycol-polypropylene glycol allyl butyl ether (Unisafe PKA-5015, PKA-5016, PKA-5017, manufactured by NOF Corporation) or polypropylene glycol diallyl ether (Unisafe PKA-5018, manufactured by NOF Corporation). In particular, polyethylene glycol-polypropylene glycol allyl butyl ether (PKA-5016, PKA-5017, manufactured by NOF Corporation) is preferable because of its excellent compatibility with urethane (meth) acrylate.
The number average molecular weight of this compound (A) is 100-10000 normally, 500-8000 are preferable, 1000-8000 are more preferable, 1500-5000 are especially preferable. If the number average molecular weight is too small, the flexibility and adhesiveness may be inferior. If it is too large, the compatibility may be inferior.

  The weight ratio of the compound (A) in the photocurable transparent adhesive composition of the present invention is preferably about 1% to 60% by weight, particularly preferably about 10% to 50% by weight. If the amount is too small, the flexibility is inferior, and if the amount is too large, the curability deteriorates.

The composition of the present invention contains a (meth) acrylate compound (B) (hereinafter also referred to as component (B)). Any (meth) acrylate compound can be used without particular limitation as long as it is a known compound.
As the (meth) acrylate compound (B), a (meth) acrylate compound having one or two (meth) acryloyl groups is preferable, and the component (B) is more preferably 100% by weight in these components.
In particular, as the component (B), a (meth) acrylate compound (B ′) having one (meth) acryloyl group described below (hereinafter also referred to as a component (B ′)) and a urethane (meth) acrylate (D) (hereinafter referred to as “component”) (Also referred to as component (D)) is preferred. Other polyfunctional (meth) acrylates can also be used. As a preferable embodiment, the total content of the component (B ′) and the component (D) is 50 to 100% by weight (hereinafter referred to as “%” unless otherwise specified) with respect to the total amount of the (meth) acrylate compound (B). Mean), more preferably 70 to 100%, still more preferably 90 to 100%. The balance is other (meth) acrylate compounds. Most preferred is the case where the component (B) is composed of both of the above (when the sum of the components is 100% of the component (B)).
In the present specification, “(meth) acrylate” means either one or both of methacrylate and acrylate.

As the (meth) acrylate compound (B) contained in the resin composition of the present invention, a (meth) acrylate compound (B ′) having one (meth) acryloyl group is preferably used.
Specifically, isooctyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, cetyl (meth) acrylate, isomyristyl (meth) acrylate, tridecyl ( C5-C30 alkyl (meth) acrylate such as (meth) acrylate and 2-decyltetradecanyl (meth) acrylate, more preferably C10-30 alkyl (meth) acrylate; benzyl (meth) acrylate, tetrahydro Furfuryl (meth) acrylate, acryloylmorpholine, phenylglycidyl (meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl ) Acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 1-adamantyl methacrylate, dicyclopentadieneoxy (Meth) acrylate having a cyclic structure such as ethyl (meth) acrylate, preferably 3 to 10 membered ring containing 3 to 10 carbon atoms, and may contain either one or both of oxygen atom and nitrogen atom, Preferably (meth) acrylate having 3 to 10-membered aliphatic ring or benzyl group; alkyl having 1 to 5 carbon atoms having a hydroxyl group such as 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate ( Meta) Acrelay Polyalkylene glycols such as ethoxydiethylene glycol (meth) acrylate, 2-ethylhexyl diethylene glycol (meth) acrylate (also known as 2-ethylhexyl carbitol (meth) acrylate), polypropylene glycol (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate (Meth) acrylate or polyalkylene glycol modified nonylphenyl (meth) acrylate, preferably poly C2-C4 alkylene glycol (meth) acrylate or polypropylene oxide modified nonylphenyl (meth) acrylate; ethylene oxide modified phenoxylated phosphoric acid (meth) acrylate, Ethylene oxide modified butoxylated phosphoric acid (meth) acrylate and ethylene oxide Mention may be made of ethylene oxide-modified phenoxylation such as modified octyloxylated phosphoric acid (meth) acrylate or C3-C10 alkoxylated-phosphoric acid (meth) acrylate.

Preferred compounds as the component (B ′) include alkyl (meth) acrylates having 10 to 30 carbon atoms; poly C2 to C4 alkylene glycol (meth) acrylates; polypropylene oxide-modified nonylphenyl (meth) acrylates; -5 alkyl (meth) acrylates; acryloylmorpholine; tetrahydrofurfuryl (meth) acrylates and / or dicyclopentenyloxyethyl (meth) acrylates.
Among them, C10-30 alkyl (meth) acrylate, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate Polypropylene oxide-modified nonylphenyl (meth) acrylate (for example, propylene oxide 2 to 10 mol-modified nonylphenyl (meth) acrylate) is preferable. In particular, from the viewpoint of flexibility of the resin, alkyl (meth) acrylate having 10 to 30 carbon atoms, dicyclopentenyloxyethyl (meth) acrylate, polypropylene oxide-modified nonylphenyl (meth) acrylate (for example, 2 to 10 mol-modified propylene oxide) Nonylphenyl (meth) acrylate) and tetrahydrofurfuryl (meth) acrylate are preferred.
On the other hand, from the viewpoint of improving the adhesion to glass, a C1-C5 alkyl (meth) acrylate having a hydroxyl group and acryloylmorpholine are preferable, and acryloylmorpholine is particularly preferable.
It is more preferable when the component (B ′) is composed of the above-mentioned preferable compounds and is composed entirely (100%).
As the alkyl (meth) acrylate having 10 to 30 carbon atoms, a preferable compound is an alkyl (meth) acrylate having 12 to 25 carbon atoms. Specifically, the lauryl (meth) acrylate exemplified above is converted into 2-decyltetradecanyl ( Illustrative compounds up to (meth) acrylate, most preferably lauryl (meth) acrylate and 2-decyltetradecanyl (meth) acrylate.

The resin composition of the present invention can contain a polyfunctional (meth) acrylate compound as long as the characteristics of the present invention are not impaired. For example, tricyclodecane dimethylol di (meth) acrylate, dioxane glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, alkylene oxide modified bisphenol A type di (meth) acrylate , Trimethylol C2-C10 alkanes such as caprolactone-modified hydroxypivalic acid neopentyl glycol di (meth) acrylate and ethylene oxide-modified phosphoric acid di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethyloloctanetri (meth) acrylate Tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri ( Trimethylol C2-C10 alkane polyalkoxy tri (meth) acrylate such as acrylate, trimethylolpropane polyethoxypolypropoxy tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, pentaerythritol tri ( (Meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate and other alkylene oxide modified trimethylolpropane tri (meth) acrylate pentaerythritol polyethoxytetra (meth) acrylate, Pentaerythritol polypropoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrime Trimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.
In the present invention, it is preferable to use mono- or bifunctional (meth) acrylate in order to suppress curing shrinkage.
In order to further reduce the curing shrinkage, the resin composition of the present invention comprises the component (B ′) as the component (B) other than the urethane (meth) acrylate (D) and the component (B) other than the component (D). It contains at least 50% by weight, preferably at least 70% by weight, more preferably at least 80% by weight, still more preferably at least 90% by weight, and most preferably 100% by weight, based on the total amount of the components.

In the resin composition of this invention, these (B) components other than these urethane (meth) acrylate (D) can be used 1 type or in mixture of 2 or more types in arbitrary ratios. The weight ratio of the component (B) other than the urethane (meth) acrylate (D) in the photocurable transparent adhesive composition of the present invention is usually 5 to 70% by weight, preferably 5 to 50% by weight, more preferably. 10 to 40%.
In particular, it is preferable when the (meth) acrylate compound (B ′) having one (meth) acryloyl group has the above content.
If the content of the component (B) other than the urethane (meth) acrylate (D) is too low, curability is poor, and if it is too high, shrinkage increases.

  As the urethane (meth) acrylate (D) that can be contained in the composition of the present invention, any urethane (meth) acrylate can be used. Preferably, it is urethane (meth) acrylate obtained by making a polyhydric alcohol, polyisocyanate, and a hydroxyl group containing (meth) acrylate react. More preferred is a polyetherurethane (meth) acrylate having a polyether structure.

  Examples of the polyhydric alcohol used for the synthesis of urethane (meth) acrylate include neopentyl glycol, 3-methyl-1,5-pentanediol, ethylene glycol, propylene glycol, 1,4-butanediol, 1, C1-C10 alkylene glycol such as 6-hexanediol, triol such as trimethylolpropane and pentaerythritol, alcohol having a cyclic skeleton such as tricyclodecane dimethylol, bis- [hydroxymethyl] -cyclohexane, etc. Polyester polyols obtained by reaction of polyhydric alcohols with polybasic acids (eg succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride, etc.), polyhydric alcohols and ε- Cap Caprolactone alcohol obtained by reaction with lactone, polycarbonate polyol (for example, polycarbonate diol obtained by reaction of 1,6-hexanediol and diphenyl carbonate) or polyether polyol (for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, Ethylene oxide modified bisphenol A and the like). A polyether polyol is preferred from the viewpoint of the flexibility of the resin after curing. Polypropylene glycol is more preferred from the viewpoint of compatibility with the component (A), and polypropylene glycol having a molecular weight of 2000 or more is particularly preferred from the viewpoint of adhesion to the substrate.

Examples of the organic polyisocyanate include isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4′-diisocyanate, and dicyclopentanyl isocyanate.
From the viewpoint of transparency, isophorone diisocyanate or tolylene diisocyanate is preferable.

  Examples of the hydroxyl group-containing (meth) acrylate include hydroxy C2-C4 alkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylol cyclohexyl mono ( A (meth) acrylate, a hydroxycaprolactone (meth) acrylate, etc. can be used.

  The reaction is performed as follows, for example. That is, organic polyisocyanate is mixed with polyhydric alcohol per equivalent of hydroxyl group so that the isocyanate group is preferably 1.1 to 2.0 equivalent, more preferably 1.1 to 1.5 equivalent, and the reaction temperature Is preferably reacted at 70 to 90 ° C. to synthesize a urethane oligomer. Next, the hydroxy (meth) acrylate compound is mixed so that the hydroxyl group is preferably 1 to 1.5 equivalents per equivalent of isocyanate group of the urethane oligomer, and reacted at 70 to 90 ° C. to obtain the target urethane (meta ) Acrylate can be obtained.

  As a weight average molecular weight of a urethane (meth) acrylate (D), about 7000-25000 are preferable and 10000-20000 are more preferable. If the weight average molecular weight is too small, the shrinkage increases, and if the weight average molecular weight is too large, the curability becomes poor.

In the resin composition of this invention, these (D) components can be used 1 type or in mixture of 2 or more types in arbitrary ratios. The weight ratio of the component (D) in the photocurable transparent adhesive composition of the present invention is usually 20 to 80% by weight, preferably 25 to 50% by weight.
In the resin composition of the present invention, the total content of the component (D) and the (meth) acrylate compound (B ′) having one (meth) acryloyl group is preferably based on the total amount of the resin composition. At least 40% by weight, more preferably at least 50% by weight.

The resin composition of the present invention can contain a (meth) acrylate oligomer having a polyisoprene or / and a polybutadiene skeleton as the (meth) acrylate compound (B). As the (meth) acrylate oligomer having a polyisoprene or / and a polybutadiene skeleton, any known one can be used without particular limitation.
As the (meth) acrylate oligomer having a polyisoprene or / and a polybutadiene skeleton, preferably (a) an isoprene polymer, a butadiene polymer or a copolymer thereof is synthesized first, and then these polymers are unsaturated. An oligomer obtained by reacting an acid anhydride and then reacting a hydroxy (meth) acrylate compound with a part or all of the obtained polymer, or (b) hydroxyl-terminated isoprene polymer, hydroxyl-terminated butadiene heavy An oligomer obtained by reacting an unsaturated carboxylic acid or a derivative thereof with a copolymer or a copolymer thereof can be used.

First, (a) an isoprene polymer, a butadiene polymer or a copolymer thereof is first synthesized, then an unsaturated acid anhydride is reacted with these polymers, and then a part of the obtained polymer or All the oligomers obtained by reacting a hydroxy (meth) acrylate compound will be described.
As the isoprene polymer or butadiene polymer, an isoprene polymer or butadiene polymer obtained by polymerizing one kind of isoprene or butadiene alone may be used, or a mixture of isoprene and butadiene is copolymerized. The isoprene-butadiene copolymer obtained by this may be used. Hereinafter, these are collectively referred to as oligomer polymer.

As a polymerization method, isoprene and / or butadiene is obtained by anionic polymerization using alkyllithium such as methyllithium, ethyllithium, s-butyllithium, n-butyllithium, pentyllithium, or sodium naphthalene complex as an initiator. It can also be produced by radical polymerization using a peroxide such as benzoyl peroxide or an azobisnitrile compound such as azobisisobutyronitrile as an initiator.
These polymerization reactions can be carried out by reacting at −100 ° C. to 200 ° C. for 0.5 to 100 hours in the presence of a solvent such as hexane, heptane, toluene and xylene.

The number average molecular weight of the polymer for oligomers used in the present invention is usually 2000 to 100,000, preferably 5000 to 50000, particularly preferably 20000 to 50000, from the viewpoint of imparting flexibility.
Next, an unsaturated acid anhydride is reacted with the polymer for oligomers obtained by the above method. In this reaction, for example, the polymer and the unsaturated acid anhydride are usually used in the presence of a solvent inert to the reaction, such as a solvent such as hexane, heptane, toluene, xylene or the like, or in the absence of a solvent. The reaction can be carried out for 0.5 to 100 hours.

As the unsaturated acid anhydride, for example, maleic anhydride, phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride and the like can be used.
The amount of the acid anhydride used is usually preferably in the range of 0.1 to 200 parts by weight, and in the range of 0.1 to 100 parts by weight, based on 100 parts by weight of the oligomer polymer. Is more preferable.
Addition by the reaction of an acid anhydride group to the polymer is usually in the range of 1 to 30 additions per molecule and 2 to 20 ranges by reacting under the above conditions. It is preferable that
Next, by reacting a part of or all of the acid anhydride groups introduced into the polymer with a hydroxy (meth) acrylate compound, a (meth) acrylate oligomer having a polyisoprene skeleton and a polybutadiene skeleton (meth) An (meth) acrylate oligomer having an acrylate oligomer or a polyisoprene-polybutadiene copolymer skeleton can be obtained.
The reaction is usually carried out in a solvent such as hexane or heptane or without solvent, and the hydroxy (meth) acrylate compound is mixed so that the hydroxyl group is preferably 1 to 1.5 equivalents, and 0.1 to 100 at 20 to 200 ° C. It can be obtained by reacting for hours.
Examples of the hydroxy (meth) acrylate compound include hydroxy C2-C4 alkyl (meth) acrylate such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and dimethylolcyclohexyl mono (meth) acrylate. Hydroxycaprolactone (meth) acrylate and the like can be used.

  Next, (b) a method for obtaining an oligomer obtained by reacting an unsaturated carboxylic acid or a derivative thereof with an isoprene polymer, butadiene polymer or copolymer thereof containing a hydroxy group will be described.

A (meth) acrylate oligomer having a polyisoprene skeleton by reacting an unsaturated carboxylic acid or a derivative thereof with a part or all of a hydroxyl-terminated isoprene polymer, hydroxyl-terminated butadiene polymer, or hydroxyl-terminated isoprene-butadiene copolymer. A (meth) acrylate oligomer having a polybutadiene skeleton or a (meth) acrylate oligomer having an isoprene-butadiene copolymer skeleton can be obtained.
The reaction can be usually obtained by reacting an unsaturated carboxylic acid or a derivative thereof at 20 to 200 ° C. for 0.1 to 100 hours in a solvent such as hexane or heptane or without a solvent.

  Examples of the unsaturated carboxylic acid or derivative thereof include acrylic acid, methacrylic acid, maleic acid, α-ethylacrylic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid and the like, In addition, derivatives of these acid halides, amides, imides, anhydrides, esters, and the like can be used.

  Specific examples of the compound thus obtained include UC-203 manufactured by Kuraray Co., Ltd. (maleic anhydride adduct of isoprene polymer and esterified oligomer of 2-hydroxyethyl methacrylate), NISSO-PB TE- manufactured by Nippon Soda Co., Ltd. 2000 (both end methacrylate-modified butadiene oligomer) and the like.

In the resin composition of the present invention, these polyisoprene and (meth) acrylate oligomers having a polybutadiene skeleton can be used alone or in admixture of two or more at any ratio. The weight ratio of the polyisoprene and the (meth) acrylate oligomer having a polybutadiene skeleton in the ultraviolet curable adhesive of the present invention is usually 5 to 90% by weight, preferably 20 to 80% by weight, more preferably 25 to 50% by weight. is there.
The (meth) acrylate oligomer may be used in combination with the urethane (meth) acrylate (D), and may be used instead of the urethane (meth) acrylate (D) in some cases.

  Although it does not specifically limit as a photoinitiator (C) contained in the composition of this invention, For example, 1-hydroxy cyclohexyl phenyl ketone {Irgacure (registered trademark, the following is the same) 184; made by BASF}, 2 -Hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer (Esacure ONE; manufactured by Lamberti), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl -1-propan-1-one (Irgacure 2959; manufactured by BASF), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl -Propan-1-one (Irgacure 127; manufactured by BASF), 2,2-dimethoxy-2-phenylacetophenone (I Gacure 651; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one {Darocur (registered trademark, hereinafter the same 1173; manufactured by BASF)}, 2-methyl-1- [4- (methylthio) Phenyl] -2-morpholinopropan-1-one (Irgacure 907; manufactured by BASF), oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl- A mixture of acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester (Irgacure 754; manufactured by BASF), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropyl Thioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4 -Trimethylpentylphosphine oxide, etc. From the transparency, 1-hydroxycyclohexyl phenyl ketone (Irgacure 184; manufactured by BASF), 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] Propanol oligomer (Esacure KIP-150; manufactured by Lambarty), phenylglucoxylic acid methyl ester (Darocur MBF; manufactured by BASF), oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy - ethoxy] - ethyl ester and oxy - phenyl - acetate tic acid 2- [2-hydroxy - ethoxy] - a mixture of ethyl ester (Irgacure 754; manufactured by BASF), is preferred. Further, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Speed Cure TPO; manufactured by LAMBSON) is preferable from the viewpoint of improving the adhesive internal curability.

In the resin composition of this invention, these (C) components can be used 1 type or 2 types or more mixed in arbitrary ratios. The weight ratio of the component (C) in the photocurable transparent adhesive composition of the present invention is usually 0.2 to 5% by weight, preferably 2 to 5% by weight.
Here, when only 2,4,6-trimethylbenzoyldiphenylphosphine oxide is used as a photopolymerization initiator in order to improve transparency, a preferred weight ratio in the photocurable transparent adhesive composition of the present invention Is usually 0.3 to 1.0% by weight, particularly preferably 0.3 to 0.8% by weight.

  Furthermore, as other components other than the above (A), (B) and (C), if necessary, amines which can serve as photopolymerization initiation assistants can be used in combination with the above photopolymerization initiator. Examples of amines that can be used include benzoic acid 2-dimethylaminoethyl ester, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, and p-dimethylaminobenzoic acid isoamyl ester. When using a photopolymerization initiation assistant such as the amines, the content in the adhesive resin composition of the present invention is usually 0 to 5% by weight, and when added, 0.005 to 5% by weight, preferably 0. 0.01 to 3% by weight.

Moreover, an oxetane compound can be contained as needed as other components. The oxetane compound that can be used is not particularly limited as long as it is known.
Specific examples of the oxetane compound include, for example, 4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 4-bis [(3-methyl-3-oxetanylmethoxy) methyl] benzene, 3-methyl- 3-glycidyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-methyl-3-hydroxymethyloxetane, di (1-ethyl (3-oxetanyl)) methyl ether, 3-ethyl-3- (phenoxymethyl) oxetane , 3- (cyclohexyloxy) methyl-3-ethyloxetane, xylylenebisoxetane, phenol novolac oxetane and the like. It is not limited to these as long as it is a commonly used oxetane compound. These may be used alone or in combination of two or more.

  In the ultraviolet curable adhesive of the present invention, these oxetane compounds can be used alone or in admixture of two or more at any ratio. The weight ratio of the oxetane compound in the photocurable adhesive composition of the present invention is usually 0 to 70% by weight, and when added, it is 5 to 70% by weight, preferably 5 to 50% by weight.

  Moreover, an epoxy (meth) acrylate can be used for the composition of this invention as an other component in the range which does not impair the characteristic of this invention. Epoxy (meth) acrylate has a function of improving curability and improving the hardness and curing speed of a cured product. Any epoxy (meth) acrylate can be used as long as it is obtained by reacting a glycidyl ether type epoxy compound with (meth) acrylic acid, and preferably used epoxy (meth) acrylate. Examples of the glycidyl ether type epoxy compound to be obtained include diglycidyl ether of bisphenol A or its alkylene oxide adduct, diglycidyl ether of bisphenol F or its alkylene oxide adduct, diglycidyl of hydrogenated bisphenol A or its alkylene oxide adduct. Diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether of ether, hydrogenated bisphenol F or its alkylene oxide adduct Neopentyl glycol diglycidyl ether, butanediol diglycidyl ether hexanediol diglycidyl ether to, cyclohexanedimethanol diglycidyl ether, and polypropylene glycol diglycidyl ether.

  Epoxy (meth) acrylate is obtained by reacting these glycidyl ether type epoxy compounds with (meth) acrylic acid under the following conditions.

  (Meth) acrylic acid is reacted at a ratio of 0.9 to 1.5 mol, more preferably 0.95 to 1.1 mol, per 1 equivalent of the epoxy group of the glycidyl ether type epoxy compound. The reaction temperature is preferably 80 to 120 ° C., and the reaction time is about 10 to 35 hours. In order to accelerate the reaction, it is preferable to use a catalyst such as triphenylphosphine, TAP, triethanolamine, or tetraethylammonium chloride. Further, in order to prevent polymerization during the reaction, for example, paramethoxyphenol, methylhydroquinone or the like can be used as a polymerization inhibitor.

An epoxy (meth) acrylate that can be suitably used in the present invention is a bisphenol A type epoxy (meth) acrylate obtained from a bisphenol A type epoxy compound. In the present invention, the weight average molecular weight of the epoxy (meth) acrylate (G) is preferably 500 to 10,000.
In the resin composition of this invention, these epoxy (meth) acrylate can be used 1 type or in mixture of 2 or more types by arbitrary ratios. The weight ratio of the epoxy (meth) acrylate in the photocurable transparent adhesive composition of the present invention is usually 0 to 90% by weight, and when added, it is 5 to 90% by weight, preferably 10 to 85% by weight.

In the resin composition of the present invention, as necessary, a softening component can be used as the other component. Specific examples of the softening component that can be used include polyisoprene, (meth) acrylate oligomer having a polybutadiene skeleton or esterified product thereof, polymer, oligomer, phthalate ester, phosphate ester, glycol ester, aliphatic dibasic Examples thereof include acid esters, fatty acid esters, citrate esters, epoxy plasticizers, castor oils, and terpene hydrogenated resins. Examples of oligomers and polymers include polyisoprene-based, polybutadiene-based, and xylene-based oligomers or polymers.
The weight ratio of the softening component in the photocurable transparent adhesive composition is usually 10 to 80% by weight, preferably 10 to 70% by weight.

  A (meth) acrylic polymer can be used as the softening component.

Examples of the (meth) acrylic polymer include a polymer obtained by polymerizing an acrylic or methacrylic monomer as a raw material, or a copolymer of the polymerizable monomer other than the monomer and the monomer, solution polymerization, suspension polymerization. It can be produced by a usual method such as bulk polymerization.
As a particularly preferred production method, it is preferred to carry out production by continuously performing radical polymerization at a high temperature. Specifically, it is manufactured by the following process. First, a small amount of a polymerization initiator and a small amount of solvent are mixed with an acrylic or methacrylic monomer. And it is made to react under high pressure for 10 minutes or more at the temperature of 150 degreeC or more. Then, it can isolate | separate into the (meth) acrylic polymer obtained by reacting with an unreacted component with a separator, and can obtain.
Here, if a polymerization initiator is mixed, the storage stability may be poor. Therefore, the reaction is performed while distilling off the solvent, or the (meth) acrylic polymer is separated and then the solvent is distilled off. It is preferable to do.

  Examples of acrylic or methacrylic monomers used as raw materials for (meth) acrylic polymers include (meth) acrylic acid, α-ethylacrylic acid; methyl (meth) acrylate, n-propyl (meth) acrylate, and isopropyl (meth). Acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, 1,3-dimethylbutyl (meth) acrylate, hexyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 3-ethoxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) Examples include ester (meth) acrylates such as acrylate, hydroxybutyl (meth) acrylate, α- (hydroxymethyl) ethyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and phenylethyl (meth) acrylate. 1 type, or 2 or more types of these can be used.

  As the other polymerizable monomer that may be copolymerized, a known compound having an unsaturated double bond can be used. For example, styrene, 3-nitrostyrene, 4-methoxystyrene; α-methylstyrene, β -Alkyl styrenes such as methylstyrene, 2,4-dimethylstyrene, vinyltoluene, α-ethylstyrene, α-butylstyrene, α-hexylstyrene; 4-chlorostyrene, 3-chlorostyrene, 3-bromostyrene, etc. Halogenated styrenes: Carboxyl having unsaturated double bonds such as crotonic acid, α-methylcrotonic acid, α-ethylcrotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid Examples include acids.

  Among these, methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (as an acrylic or methacrylic monomer from the viewpoint of solubility in other components of the composition and adhesiveness of the cured product C1-C10 alkyl (meth) acrylate having a hydroxyl group such as C1-C10 alkyl (meth) acrylate such as (meth) acrylate and octyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and hydroxybutyl (meth) acrylate is preferable. As other polymerizable monomer, styrene or the like is preferable.

  In the present invention, the weight average molecular weight of the (meth) acrylic polymer is 1500 to 30000, preferably 3000 to 20000, and particularly preferably 5000 to 15000. When the weight average molecular weight is too small, the adhesiveness of the cured product tends to be inferior. On the other hand, when the weight average molecular weight is too large, it is difficult to dissolve in other monomers or it becomes cloudy.

  The (meth) acrylic polymer can also be easily obtained as a commercial product. For example, “ARUFON series” manufactured by Toagosei Co., Ltd. can be mentioned, and can be obtained as UP-1170 and UH-2190.

  The weight ratio of the (meth) acrylic polymer in the photocurable adhesive composition of the present invention is usually 20% to 95% by weight, preferably 50% to 95% by weight, and about 70% to 95% by weight. Is more preferable, and 70 to 90% by weight is particularly preferable.

  The resin composition of the present invention further includes, as necessary, other components such as an antioxidant, an organic solvent, a silane coupling agent, a polymerization inhibitor, a leveling agent, an antistatic agent, a surface lubricant, and a fluorescent whitening agent. You may add additives, such as an agent, a light stabilizer (for example, hindered amine compound etc.), and a filler.

  Specific examples of the antioxidant include, for example, BHT, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine , Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3-t -Butyl-5-methyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N N-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl-O-cresol, Isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], dibutylhydroxytoluene and the like.

  Specific examples of the organic solvent include alcohols such as methanol, ethanol and isopropyl alcohol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, toluene, xylene and the like.

  Specific examples of the silane coupling agent include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy) (Cyclohexyl) ethyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, γ-mercapropropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3 -Aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane 3 Silane coupling agents such as chloropropylmethyldimethoxysilane and 3-chloropropyltrimethoxysilane; isopropyl (N-ethylaminoethylamino) titanate, isopropyl triisostearoyl titanate, titanium di (dioctyl pyrophosphate) oxyacetate, tetra Titanium coupling agents such as isopropyldi (dioctylphosphite) titanate and neoalkoxytri (pN- (β-aminoethyl) aminophenyl) titanate; Zr-acetylacetonate, Zr-methacrylate, Zr-propionate, neo Alkoxy zirconate, neoalkoxy trisneodecanoyl zirconate, neoalkoxy tris (dodecanoyl) benzenesulfonyl zirconate, neoalkoxy tris ( Chi range aminoethyl) zirconate, neoalkoxy tris (m-aminophenyl) zirconate, ammonium zirconium carbonate, Al- acetylacetonate, Al- methacrylate, zirconium or the like Al- propionate, or aluminum coupling agent, and the like.

  Specific examples of the polymerization inhibitor include paramethoxyphenol and methylhydroquinone.

  Specific examples of the light stabilizer include, for example, 1,2,2,6,6-pentamethyl-4-piperidyl alcohol, 2,2,6,6-tetramethyl-4-piperidyl alcohol, 1,2,2, 6,6-pentamethyl-4-piperidyl (meth) acrylate (manufactured by ADEKA Corporation, LA-82), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3 4-butanetetracarboxylate, tetrakis (2,2,6,6-totramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] Undeka Esterified product with bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1-undecanoxy-2,2,6,6-tetramethylpiperidin-4-yl) ) Carbonate, 2,2,6,6, -tetramethyl-4-piperidyl methacrylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6) -Pentamethyl-4-piperidyl) sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpi Lysine, 1,2,2,6,6-pentamethyl-4-piperidinyl-methacrylate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [[3,5-bis (1,1 -Dimethylethyl) -4-hydroxyphenyl] methyl] butylmalonate, decanedioic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl Reaction product of hydroperoxide and octane, N, N ′, N ″, N ″ ′-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidine- 4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, dibutylamine, 1,3,5-triazine, N, N′-bis (2,2,6, 6-te A polycondensate of tramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [[6- (1,1,3, 3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6 , 6-tetramethyl-4-piperidyl) imino]], a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 2,2,4,4-tetra Methyl-20- (β-lauryloxycarbonyl) ethyl-7-oxa-3,20-diazadispiro [5 · 1 · 11 · 2] heneicosan-21-one, β-alanine, N,-(2,2,6 , 6-Tetra Methyl-4-piperidinyl) -dodecyl ester / tetradecyl ester, N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione, 2, 2,4,4-tetramethyl-7-oxa-3,20-diazadispiro [5,1,11,2] heneicosan-21-one, 2,2,4,4-tetramethyl-21-oxa-3, 20-diazadicyclo- [5,1,11,2] -heneicosane-20-propanoic acid dodecyl ester / tetradecyl ester, propanedioic acid, [(4-methoxyphenyl) -methylene] -bis (1,2,2 , 6,6-pentamethyl-4-piperidinyl) ester, a higher fatty acid ester of 2,2,6,6-tetramethyl-4-piperidinol, 1,3- Hindered amines such as benzenedicarboxamide, N, N′-bis (2,2,6,6-tetramethyl-4-piperidinyl), benzophenone compounds such as octabenzone, 2- (2H-benzotriazol-2-yl) ) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- [2-hydroxy-3- (3,4,5, 6-tetrahydrophthalimido-methyl) -5-methylphenyl] benzotriazole, 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3, 5-di-tert-pentylphenyl) benzotriazole, methyl 3- (3- (2H-benzotriazol-2-yl) ) -5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol reaction product, benzotriazole compounds such as 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol, Benzoate series such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (4,6-diphenyl-1,3,5-triazin-2-yl ) -5-[(hexyl) oxy] phenol and other triazine compounds, and the like, particularly preferably hindered amine compounds.

  Specific examples of the filler include, for example, crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc and the like. Examples thereof include powder or beads obtained by spheroidizing these.

  Since various additives are optional components, they may usually be zero. When various additives are present in the composition, the weight ratio of the various additives in the photocurable transparent adhesive composition is 0.01 to 3% by weight, preferably 0.01 to 1% by weight, and more preferably. Is 0.02 to 0.5% by weight.

The resin composition of the present invention is preferably combined with a component having a propylene skeleton in order to improve compatibility and adhesion.
Specifically, in the general formula (1), a resin composition containing urethane (meth) acrylate obtained from polypropylene glycol, a compound having a value of m / (value of m + n value) of 0.4 to 1.0. A thing can be used conveniently.

  The resin composition of the present invention can be obtained by mixing and dissolving the above-described components at room temperature to 80 ° C. If necessary, impurities may be removed by an operation such as filtration. In the adhesive resin composition of the present invention, considering the applicability, it is preferable to appropriately adjust the compounding ratio of the components so that the viscosity at 25 ° C. is in the range of 300 to 15000 mPa · s.

The curing shrinkage of the resin composition of the present invention is preferably 3.0% or less, and particularly preferably 2.0% or less. Thereby, when the ultraviolet curable resin composition is cured, the internal stress accumulated in the cured resin can be reduced, and the interface between the base material and the layer made of the cured product of the ultraviolet curable resin composition can be reduced. It is possible to effectively prevent the distortion.
In addition, when the base material such as glass is thin, the warping at the time of curing becomes large when the curing shrinkage rate is large. Is preferred.

It is preferable that the average transmittance | permeability in 400 nm-800 nm of the hardened | cured material (thickness 200 micrometers) of the resin composition of this invention is 90% or more. This is because if the transmittance is too low, light is difficult to transmit, and the visibility decreases when used in a display device.
Moreover, since the improvement of visibility can be expected further when the transmittance at 400 to 450 nm of the cured product is high, the transmittance at 400 to 450 nm is preferably 90% or more. The higher the transmittance, the better. The upper limit is good up to 100%. Actually, it is 99% or less.

The resin composition of the present invention contains a compound having a structure represented by the general formula (1), a urethane (meth) acrylate, and a (meth) acrylate having one (meth) acryloyl group. Excellent.
Usually, in order to rework, after heating the bonded base material, the base material and the adhesive layer are peeled off by cutting the adhesive layer using a wire. In this case, a solvent is used to facilitate peeling. However, in the present invention, since the components of the composition are excellent in peeling properties, peeling is easily performed even if an alcohol such as isopropyl alcohol is used as the solvent. be able to.

Below, the preferable aspect of the resin composition of this invention is illustrated.
(I) In the ultraviolet curable resin composition containing the compound (A) of the formula (1), the (meth) acrylate compound (B) and the photopolymerization initiator (C), the compound (A) of the formula (1) An ultraviolet curable resin composition having a molecular weight of 100 to 10,000.
(Ii) The ultraviolet curable resin composition according to the above (i), wherein the molecular weight of the compound (A) of the formula (1) is 500 to 8000.
(Iii) The ultraviolet curable resin composition according to the above (i), wherein the molecular weight of the compound (A) of the formula (1) is 1000 to 8000.
(Iv) The above (i) ultraviolet curable resin composition, wherein the molecular weight of the compound (A) of the formula (1) is 1500 to 5000.
(V) R ¹ and R ² in the compound (A) of the formula (1) are each independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 3 to 10 carbon atoms (i) to (iv) The ultraviolet curable resin composition as described in any one of these.
(Vi) The ultraviolet curable resin composition according to (v), wherein R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 3 to 5 carbon atoms.
(Vii) The ultraviolet curable resin composition according to any one of (i) to (vi), wherein m / (m + n) is 0.2 to 1.
(Viii) The ultraviolet curable resin composition according to (vii), wherein m / (m + n) is 0.4 to 1.
(Ix) n is 5 to 40, m is 10 to 40, and one of R ¹ and R ² is a butyl group and the other is an allyl group, or n is 0 and m is 20 to 20 80. The ultraviolet curable resin composition according to (vi) above, wherein R ¹ and R ² are each independently an alkyl group having 1 to 4 carbon atoms, preferably a methyl group.

(X) The above compound (A) is polypropylene glycol diallyl ether, polypropylene glycol dimethyl ether, polypropylene glycol dibutyl ether, polypropylene glycol allyl butyl ether, polyethylene glycol-polypropylene glycol diallyl ether, polyethylene glycol-polypropylene glycol dibutyl ether, and polyethylene glycol-polypropylene glycol. The ultraviolet curable resin composition according to (vi), which is at least one selected from the group consisting of allyl butyl ether.
(Xi) The above (i) to (x) containing (meth) acrylate compound (B ′) having one urethane (meth) acrylate (D) and one (meth) acryloyl group as (meth) acrylate compound (B). The ultraviolet curable resin composition as described in any one of 1).
(Xii) The ultraviolet curable resin composition according to the above (xi), wherein the urethane (meth) acrylate (D) has a weight average molecular weight of 7000 to 25000.
(Xiii) The ultraviolet curable resin composition according to the above (xi), wherein the urethane (meth) acrylate (D) has a weight average molecular weight of 10,000 to 20,000.
(Xiv) The ultraviolet curing according to any one of (xi) to (xiii) above, wherein the urethane (meth) acrylate (D) is a reaction product of a polyether polyol, a polyisocyanate, and a hydroxyl group-containing (meth) acrylate. Mold resin composition.
(Xv) Alkyl (meth) acrylate having 10 to 30 carbon atoms as (meth) acrylate compound (B ′) having one (meth) acryloyl group; Poly C2 to C4 alkylene glycol (meth) acrylate; Polypropylene oxide-modified nonylphenyl (Meth) acrylate; an alkyl (meth) acrylate having 1 to 5 carbon atoms having a hydroxyl group; acryloylmorpholine; at least one selected from the group consisting of tetrahydrofurfuryl (meth) acrylate and dicyclopentenyloxyethyl (meth) acrylate The ultraviolet curable resin composition according to any one of (xi) to (xiv) above.

(Xvi) As a (meth) acrylate compound (B ′) having one (meth) acryloyl group, lauryl (meth) acrylate, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, isostearyl (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isostearyl (meth) acrylate, 2-decyltetradecanyl (meth) acrylate The ultraviolet curable resin composition according to the above (xv), which contains at least one selected from the group consisting of:
(Xvii) The content of the compound (A) is 10 to 60% by weight, the content of the photopolymerization initiator (C) is 0.2 to 5% by weight, and the balance is the (meth) acrylate compound (B) The ultraviolet curable resin composition according to any one of (xi) to (xiv).
(Xviii) The total content of the (meth) acrylate compound (B ′) having one urethane (meth) acrylate (D) and one (meth) acryloyl group is 50 to the total amount of the (meth) acrylate compound (B). The ultraviolet curable resin composition according to (xvii), which is 100% by weight.
(Xix) The ultraviolet curable resin composition according to the above (xviii), wherein the total content of the component (D) and the component (B ′) is 90 to 100% by weight with respect to the total amount of the component (B).
(Xx) The ultraviolet curable resin composition according to any one of (i) to (xix), which has a curing shrinkage rate of 3% or less.
(Xxi) The ultraviolet curable resin composition according to the above (xx), which has a curing shrinkage rate of 2% or less.
(Xxii) The ultraviolet curable resin composition according to any one of (i) to (xxi), wherein an average transmittance at 400 to 800 nm of a cured product having a thickness of 200 μm is at least 90%.
(Xxiii) The ultraviolet curable resin composition according to any one of (i) to (xxii), wherein an average transmittance at 400 to 450 nm of a cured product having a thickness of 200 μm is at least 90%.

The resin composition of the present invention is applied to one substrate using a coating device such as a slit coater, roll coater, spin coater, or screen printing method so that the thickness of the applied resin is 10 to 300 μm. And the other base material is bonded together, and it can be made to adhere by irradiating and curing, for example, ultraviolet to near ultraviolet (wavelength of 200 to 400 nm) as an active energy ray from the transparent base material side. Irradiation dose is preferably from about 100~4000mJ / cm ^2, particularly preferably about 200~3000mJ / cm ^2. For curing by irradiation with ultraviolet to near ultraviolet rays, any light source may be used as long as it is a lamp that irradiates ultraviolet to near ultraviolet rays. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, or electrodeless lamp can be used.

The resin composition of the present invention can be suitably used for bonding two or more optical substrates. And the optical member of this invention can be obtained by bonding together the above-mentioned at least 2 optical base material. In more detail, after bonding at least two optical substrates using the resin composition of the present invention, the ultraviolet curable resin composition layer sandwiched between the two optical substrates is irradiated with ultraviolet rays. By doing this, the optical composition of the present invention can be obtained by curing the resin composition layer to obtain a cured product layer.
The optical substrate is bonded, for example, by applying the resin composition of the present invention to the bonded surface of one optical substrate, or the present invention on both bonded surfaces of two optical substrates to be bonded. The resin composition may be applied and bonded together so that the application layer of the resin composition of the present invention is sandwiched between the bonding surfaces of the two optical substrates.
The optical substrate is not particularly limited, but a plate-like or sheet-like optical substrate is preferable. Examples of the plate-like or sheet-like optical substrate include plates, sheets, display bodies (or display body units), touch panels (or touch panel units) including the following transparent plates, and the like.

One preferred optical member of the present invention is a touch panel having a protective optical substrate.
For example, in the touch panel, two glass or resin-made transparent sheet-like or transparent plate-like optical base materials having transparent electrodes such as ITO films for electrodes on one surface, the transparent electrode surfaces face each other, A small gap is opened and it is pasted with an adhesive. One optical substrate is a substrate, and the other optical substrate is an optical substrate for a touch surface. Furthermore, if necessary, the protective sheet (or board), the icon sheet (or board), or the decorative sheet (or board) is protected on the surface on the touch surface side of the optical substrate for the touch surface with an adhesive. It has a structure in which an optical substrate is bonded with an adhesive. The touch panel as an optical member of the present invention is a touch panel obtained by using the resin composition of the present invention as an adhesive in the touch panel having the structure as an adhesive at at least one place. Therefore, this touch panel is one in which at least two optical substrates are bonded with the cured product layer of the resin composition of the present invention.
Examples of the touch panel according to a preferred embodiment of the present invention include a touch panel having a protective optical substrate adhered on the touch surface of the touch panel and a cured product layer of the resin composition of the present invention.
Another preferred embodiment is a display device with a touch panel in which a touch panel having a protective optical substrate is bonded to the display surface with a cured layer of the resin composition of the present invention.
Further, as another preferred optical member of the present invention, a display device for image display including an optical member in which at least two of the above optical substrates are bonded with a cured layer of the resin composition of the present invention. Can be mentioned. As a typical example, a display device in which a protective optical substrate or a touch panel is bonded to the surface of an image display screen with a cured product layer of the resin composition of the present invention can be exemplified. In such a case, both the touch panel before the bonding and the display body are included in the optical base material in the present invention.

Moreover, the resin composition of this invention can be conveniently used as an adhesive agent which bonds a some transparent plate or sheet | seat in a touch panel.
As the transparent plate or sheet, a transparent plate or sheet using various materials can be used.
Specifically, polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), composite of PC and PMMA, glass, cycloolefin copolymer (COC), cycloolefin polymer (COP), triacetyl A transparent plate or sheet made from a resin (plastic) such as cellulose (TAC) or acrylic resin, a functional transparent laminated plate or sheet such as a polarizing plate obtained by laminating a plurality thereof, and a transparent plate made from inorganic glass {Inorganic glass plates and processed products thereof (for example, lenses, prisms, ITO glass)} and the like can be used.
Further, in the present invention, the plate-like or sheet-like optical base material includes the above-described functional transparent laminated plate or sheet such as a transparent plate or sheet or a polarizing plate, a touch panel, a liquid crystal display plate, or an LED. A laminate of a plurality of functional plates or sheets (hereinafter also referred to as a functional laminate) such as a display body is included.
In the present invention, the plate-like or sheet-like optical substrate described above is preferable.

The resin composition of the present invention can also be used as an adhesive for bonding a touch panel and a sheet or plate.
Here, examples of the sheet include an icon sheet, a decorative sheet, and a protective sheet, and examples of the plate include a decorative board and a protective plate. And as a material of a sheet | seat thru | or board, what was enumerated as a material of a transparent board is applicable. Examples of the material for the touch panel surface include glass, PET, PC, PMMA, a composite of PC and PMMA, COC, and COP.

  The resin composition of the present invention can also be suitably used for bonding an optical functional material to the display surface of a display device. As a display apparatus body, display apparatuses, such as LCD which stuck the polarizing plate on glass, EL display, EL illumination, electronic paper, a plasma display, are mentioned. In addition, examples of the optical functional material include transparent plastic plates such as acrylic plates, PC plates, PET plates, and PEN plates, tempered glass, and touch panels.

When used as an adhesive that bonds a transparent plate, the refractive index of the cured product is preferably 1.45 to 1.55 for improved visibility.
Within the range of the refractive index, the difference in refractive index from the base material used as the transparent plate can be reduced, and light loss can be reduced by suppressing light irregular reflection.

In addition, an electronic device incorporating a display device having an optical base (for example, an optical functional material) laminated with the resin composition of the present invention, such as a television, a small game machine, a mobile phone, a personal computer, etc. is also an optical member of the present invention. include.
Preferred embodiments of the optical member of the present invention are shown below.
(I) An optical member in which at least two optical substrates are pasted together by the cured product layer of the ultraviolet curable resin composition according to any one of (i) to (xxiii) of the present invention.
(II) The optical member according to (I), wherein the optical base material to be bonded is a plate-like or sheet-like optical base material.
(III) One plate-like or sheet-like optical substrate to be bonded is a protective optical substrate, the other plate-like or sheet-like optical substrate is a touch panel, and the obtained optical member is a protective optical substrate. The optical member according to (II) above, which is a touch panel having a substrate.
(IV) One optical base material is a protective optical base material or a touch panel, the other optical base material is a display device, and the obtained optical member is pasted on the display screen of the display device with the cured product layer. A display device having a protected optical substrate or touch panel.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Hereinafter, Examples 2 to 11 are read as Reference Examples 1 to 10.

Examples 1 to 11 and Comparative Example 1
Each raw material compound was mixed so that it might become a composition shown in following Table 1, and each ultraviolet curable resin composition which consists of a uniform composition was prepared, and this invention and the resin composition for a comparison were obtained.

In addition, each component shown with the abbreviation in Table 1 is as follows.
Unisafe PKA-5016 (trade name): polyethylene glycol-polypropylene glycol allyl butyl ether (a compound in which R ₁ is allyl, R ₂ is butyl, n = 15, m = 15, and number average molecular weight 1600 in the general formula (1)) Unisafe PKA-5017 (trade name) manufactured by NOF CORPORATION: Polyethylene glycol-polypropylene glycol allyl butyl ether (in general formula (1), R ₁ is allyl, R ₂ is butyl, n = 23, m = 23, number average Compound having a molecular weight of 2500, PPG2000-DME manufactured by NOF Corporation: Polypropylene glycol dimethyl ether (in the general formula (1), R ₁ is methyl, R ₂ is methyl, n = 0, m = 34, number average molecular weight 2000) Some compound)
PPG4000-DME: Polypropylene glycol dimethyl ether (in the general formula (1), R ₁ is methyl, R ₂ is methyl, n = 0, m = 68, number average molecular weight 4000)
UA-1: A reaction product of polypropylene glycol (molecular weight 3000), isophorone diisocyanate, and 2-hydroxyethyl acrylate in a molar ratio of 1: 1.3: 2.
ACMO: acryloylmorpholine, Kojin Co., Ltd. 4-HBA: 4-hydroxybutyl acrylate, Osaka Organic Chemical Industries, Ltd. LA: lauryl acrylate, Osaka Organic Chemical Industries, Ltd. FA-512AS: dicyclopentenyloxyethyl acrylate, Hitachi Chemical Industries, Ltd. THFA: Tetrahydrofurfuryl acrylate, Osaka Organic Chemical Industries, Ltd. M-117: Propylene oxide 2.5 mol modified nonylphenyl acrylate, Toa Gosei Co., Ltd. NP-5P: Propylene oxide 5 mol modified nonyl Phenyl acrylate, Daiichi Kogyo Seiyaku Co., Ltd. S-1800A: Isostearyl acrylate, Shin-Nakamura Chemical Co., Ltd. DTD-A: 2-decyltetradecanyl acrylate, Kyoeisha Chemical Co., Ltd. Irgakyu -184 (trade name): 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF KIP-150 (trade name): 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer, manufactured by Lamberti Speed cure TPO (trade name): 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Z-6062 (product number) manufactured by LAMBSON: 3-mercaptopropyltrimethoxysilane, manufactured by Toray Dow Corning

The following evaluation was performed using the obtained resin composition of the present invention.
Curability:
Two slide glasses having a thickness of 1 mm were bonded so that the film thickness of the obtained resin composition was 200 μm. The resin composition sandwiched between slide glasses was irradiated with 2000 mJ / cm ² of ultraviolet light through a glass with a high-pressure mercury lamp (80 W / cm, ozone-less) to cure the resin composition, and the cured state was confirmed.
○ ・ ・ ・ Completely cured △ ・ ・ ・ Semi-cured state × ・ ・ ・ Uncured

Curing shrinkage:
Two 1 mm-thick slide glasses coated with a fluorine-based mold release agent were bonded to each other so that the obtained resin composition had a thickness of 200 μm. The resin composition sandwiched between the slide glasses was irradiated with ultraviolet light of 2000 mJ / cm ^{2 with} a high-pressure mercury lamp (80 W / cm, ozone-less) through the glass and cured to prepare a cured product for measuring the film specific gravity. This was measured based on JIS K7112 B method, and the specific gravity (DS) of the cured product was measured. Moreover, liquid specific gravity (DL) of the resin composition was measured at 25 degreeC, and the cure shrinkage rate was computed from following Formula.
Curing shrinkage (%) = (DS−DL) ÷ DS × 100
◎ ・ ・ ・ less than 2.0% ○ ・ ・ ・ 2.0% or more, less than 3.0% × ... 3.0% or more

Adhesiveness:
A slide glass having a thickness of 0.8 mm and an acrylic plate having a thickness of 0.8 mm were bonded so that the film thickness of the obtained ultraviolet curable resin composition became 200 μm. The resin composition sandwiched between the slide glasses was irradiated with 2000 mJ / cm ² of ultraviolet light through a glass with a high-pressure mercury lamp (80 W / cm, ozone-less) to prepare a sample for evaluation. This was left for 250 hours in an environment of 85 ° C. and 85% RH, and peeling was confirmed visually.
○ ・ ・ ・ No peeling × ・ ・ ・ Peeling

Flexibility:
The obtained ultraviolet curable resin composition was fully cured, the durometer E hardness was measured according to JIS K7215, and the flexibility was evaluated.
◎ ... less than 10 ○ ... 10 or more, less than 20 × ... 20 or more

transparency:
Two slide glasses having a thickness of 1 mm coated with a fluorine-based release agent were bonded so that the thickness of the cured layer of the obtained ultraviolet curable resin composition was 200 μm. The resin composition sandwiched between the slide glasses was irradiated with ultraviolet rays of 2000 mJ / cm ^{2 with} a high-pressure mercury lamp (80 W / cm, ozone-less) through the glass to prepare a cured product for measuring transparency. Transparency measured the transmittance | permeability of 400-800 nm and 400-450 nm using the spectrophotometer (U-3310, Hitachi High-Technologies Corporation).
◎ ... Transmittance 90% or more of 400 to 800 nm and 90% of 400 to 450 nm
○: The transmittance of 400 to 800 nm is 90% or more and the transmittance of 400 to 450 nm is 88 to 90%.
×: Transmittance of 400 to 800 nm is less than 90%

From the results shown in Table 1, Examples 1 to 11 of the present invention containing a polyether compound (( A ) component) and a (meth) acrylate compound (( B ) component) having a structure represented by the general formula (1). It was confirmed that the resin composition is excellent in curability, has a small shrinkage at the time of curing, and can obtain an optical transparent adhesive excellent in transparency of the cured product, adhesion to the substrate and flexibility.

Claims (9)

Compound (A) having the structure represented by the following general formula (1), UV curable type for touch panel containing 4-hydroxybutyl (meth) acrylate and photopolymerization initiator (C) as (meth) acrylate compound (B) Resin composition.

(In the formula, n is an integer of 0 to 40, m is an integer of 10 to 80, R ¹ and R ² may be the same as or different from each other, an alkyl group having 1 to 18 carbon atoms, A alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, or an aryl group having 5 to 18 carbon atoms.) The ultraviolet curable resin composition for touchscreens of Claim 1 containing a softening agent. The ultraviolet curable resin composition for touchscreens of Claim 1 or Claim 2 containing a (meth) acrylate oligomer. The ultraviolet curable resin composition for touchscreens of Claim 3 containing the (meth) acrylate oligomer which has polyisoprene or / and a polybutadiene frame | skeleton, or urethane (meth) acrylate (D) as a (meth) acrylate oligomer. The content of the compound (A) is 10 to 60% by weight, the content of the photopolymerization initiator (C) is 0.2 to 5% by weight, and the balance is the (meth) acrylate compound (B). The ultraviolet curable resin composition for touchscreens as described in any one of 4. The touch panel with which at least 2 optical base material was adhere | attached with the hardened | cured material layer of the ultraviolet curable resin composition for touchscreens as described in any one of Claims 1-5. Hardened | cured material obtained by irradiating an active energy ray to the ultraviolet curable resin composition for touchscreens as described in any one of Claims 1-5. A touch panel in which at least two optical substrates are bonded by a cured product layer of the ultraviolet curable resin composition for a touch panel according to claim 7. A display device having a protective optical substrate or a touch panel, wherein the protective optical substrate or the touch panel and the display device are bonded by the cured product layer of the ultraviolet curable resin composition for a touch panel according to claim 7.