JP2013170215A - Optical resin composition, method for producing image display by using the same and image display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical resin composition capable of sufficiently progressing its curing at a shielded part by exposure only to a light-transmissive part, even when the shielded part is installed on filling the resin composition into a space of a display for photo-curing, and a method for producing an image display, etc., by using the same.SOLUTION: While a resin composition is placed between transparent, opposingly placed substrate plates any of which has a shielded part, and the resin composition is cured to make a resin cured material, the photocurable type optical resin composition is characterized by using as the resin composition, a mixture containing (A) a urethane(meth)acrylate having ≥1 ethylenically unsaturated bond in its molecule, (B) a plasticizer, (C) a photopolymerization initiator, and (D) a thiol compound expressed by general formula (I), wherein component (A) comprises (A1) an urethane(meth)acrylate having a 1,000 to 5,000 weight-average molecular weight and expressed by general formula (II) and (A2) a urethane(meth)acrylate having a 7,000 to 30,000 weight-average molecular weight.

Description

  The present invention relates to an optical resin composition that is useful for preventing cracking of an image display device, relaxing stress and impact, and having excellent transparency, a method for producing an image display device using the composition, and a produced image. The present invention relates to a display device, and more particularly to an improvement in a method for curing an optical resin composition filled between substrates having a light shielding portion.

A liquid crystal display device is exemplified as a typical image display panel. A liquid crystal display device includes a liquid crystal cell in which liquid crystal is filled and sealed through a gap of about several microns between a glass substrate having a thickness of about 1 mm on which transparent electrodes, pixel patterns, etc. are formed, and both outer surfaces thereof. It is a thin and easily scratched display part made of an optical film such as a polarizing plate attached to the surface.
For this reason, in particular, for mobile phones, game machines, digital cameras, in-vehicle applications, etc., a liquid crystal display device having a structure in which a transparent front plate (protective panel) is provided with a certain space in front of the liquid crystal display device is generally used. Has been used.
Furthermore, in recent years, touch panels have been mounted on mobile phones, game machines, digital cameras, in-vehicle components, notebook computers, desktop computers, personal computer monitors, and the like. Such a display device has a laminated structure of a front plate, a touch panel, and a liquid crystal image display device, and air is interposed between the front plate and the touch panel, and between the touch panel and the liquid crystal image display device. These spaces cause light scattering, resulting in a decrease in contrast and brightness.
In addition, the current large liquid crystal display generally has an anti-glare (AG) treatment on the front polarizing plate surface of the liquid crystal panel to reduce reflection. In the case of this configuration, no special measures are taken with respect to shock absorption, and the entire panel and the structure as a set are provided with impact resistance.
The problem with this configuration is that the image looks blurred due to AG processing, the panel is bent when touching the surface, the image is distorted, and it is difficult to remove dirt due to AG processing, and it is easy to get scratched. As the size of the panel increases, the impact resistance of the panel may decrease, and a problem may occur in the impact resistance.
In view of this, it is conceivable that a front plate subjected to anti-reflection (AR) processing is placed in front of the liquid crystal panel to eliminate the disadvantages derived from AG processing.
However, when the space between the front plate and the liquid crystal panel is air, there may be a decrease in transmittance and a decrease in image quality due to double projection, and it has been proposed to fill the space with resin or the like (for example, Patent Documents). 1-4).
Glass cathode ray tubes (CRT) are determined to be non-scattering or not penetrated by an impact resistance test by dropping a steel ball according to UL standards or radio wave control methods for televisions and displays. Therefore, in order to satisfy this standard, it is necessary to design the CRT glass to be thick, and the weight of the CRT is increased.
Then, the method of laminating | stacking the synthetic resin protective film which has a self-restoration property on glass as a means to give scattering prevention property without making glass thick is proposed (for example, refer patent document 5).
However, this method is characterized by scattering prevention, but does not have a function of preventing glass from breaking.
On the other hand, the PDP, which is one of the flat panel displays (FPD), has a space of about 1 to 5 mm from the PDP to prevent cracking of the PDP, and a front plate such as a glass of about 3 mm in thickness on the front (viewing surface). Side). For this reason, as the PDP is increased in size, the area of the front plate is also increased, which increases the weight of the PDP.
Therefore, in order to prevent cracking of the display, it has been proposed to laminate a specific resin on the display surface or to laminate an optical filter on which the specific resin is laminated (for example, refer to Patent Documents 6 to 8). ).

However, the oil used in Patent Document 1 is difficult to seal in order to prevent leakage, and there is a possibility that the material used in the liquid crystal panel may be eroded, so that the oil leaks when the front plate is cracked. There's a problem.
Further, the unsaturated polyester of Patent Document 2 is easily colored yellow, and is not desirable for application to a display device.
The silicone of Patent Document 3 has a low adhesive force and requires a separate pressure-sensitive adhesive for fixing, and the process becomes complicated. Further, since the adhesive force with the pressure-sensitive adhesive is not so large, it peels off when an impact is applied. There is a problem that air bubbles enter.
The polymer of the acrylic monomer of Patent Document 4 has a low adhesive force and does not require a separate adhesive for small devices, but requires a separate adhesive to support the front panel of a large display, and the process It becomes complicated. In addition, since the raw material is composed only of the monomer, the viscosity is low, and the curing shrinkage is large, so that it is difficult to uniformly produce a large-area film.
Patent Document 5 is characterized by anti-scattering properties as described above, but does not have a function of preventing glass from breaking.
In Patent Documents 6 and 7, there is no particular consideration regarding the composition of the resin material to be used, and the means for expressing adhesiveness and transparency is unclear. In particular, in Patent Document 7, there is no consideration on the moisture resistance reliability of the resin, and the resin material having the composition specifically shown in the examples becomes cloudy in a short time moisture resistance test after being applied to a display.
Also in Patent Document 7, acrylic acid is used as a part of the resin specifically shown in the examples, and the resin becomes clouded in a long-time moisture resistance test, and the metal that is in contact during the moisture resistance test This causes the problem of corroding.
Further, in Patent Documents 6 and 7, it is considered that the examination is insufficient from the viewpoint of obtaining better shock absorption.
In Patent Document 7, the thickness of the impact-resistant layer using a resin is set to 0.2 to 1 mm, but there is no disclosure from the viewpoint of increasing the thickness to further improve the shock absorption.
In Patent Document 8, consideration is given to heat and humidity resistance, but the resin material composition described in this Patent Document cannot be expected to significantly improve impact resistance.
Moreover, the thickness of the resin layer in an Example is 1 mm, and it is thought that examination is inadequate from a viewpoint of obtaining the more outstanding impact absorbability.
In addition, as described in the example of Patent Document 8, if a soft resin after curing is used thickly, the surface hardness of the front filter is lowered, which may cause a problem in scratch resistance. Conceivable.

JP 05-011239 A Japanese Patent Laid-Open No. 03-204616 Japanese Patent Laid-Open No. 06-059253 JP 2004-125868 A Japanese Patent Laid-Open No. 06-333515 JP 2004-058376 A JP 2005-107199 A JP 2004-263084 A

By the way, in the above-described image display device such as a liquid crystal display device, a frame-shaped light shielding portion having a predetermined width is provided along the outer peripheral edge of the protective panel for the purpose of improving the contrast of the display image. Has been done.
The light-shielding part also has a function of blocking unnecessary light around the liquid crystal display panel, and also has a role of preventing deterioration in display quality due to light leakage.
However, when the light shielding portion is provided on the protective panel, there is a problem that sufficient light does not reach the resin filled between the image display panel and the protective panel, which hinders curing. For example, when a protective panel is placed on an image display unit in which a liquid crystal display panel is incorporated in a frame, a photocurable resin composition is filled between the protective panels, and curing is attempted by light irradiation, the light-shielding portion is exposed to light. Irradiation may be hindered, and in particular, there is a possibility that curing of the resin composition around the light-shielding portion will not sufficiently proceed.
If the resin composition is not sufficiently cured, the quality of the image display device will be greatly impaired, which will be a major factor in reducing the reliability.
On the other hand, the ene / thiol curing reaction using an ene compound and a thiol compound is not highly inhibited by air and is extremely reactive. The thiol compound also acts as a chain transfer agent during the radical polymerization reaction. The chain transfer agent means a compound that moves the active site of the reaction by a chain transfer reaction. However, when the concentration of the unsaturated double bond of the ene / thiol-cured ene compound is low, there is a problem that the resin component bleeds out in the accelerated reliability test at high temperature and high humidity.
The present invention provides a resin composition in a liquid display space (between a protective plate and a liquid crystal display device, between a protective plate and a touch panel, and between a touch panel and a liquid crystal display device) that is easy to handle at room temperature. In the manufacturing process of the image display device to be cured after filling, even in the case of a substrate provided with a light shielding part, a heat treatment or the like is not required, and the light shielding part is sufficiently cured only by exposure to the light transmitting part. It is a first object of the present invention to provide an optical resin composition that is excellent in stability and does not bleed out even when the ene / thiol cured product is at high temperature and high humidity.
It is a second object of the present invention to provide an image display device that has impact resistance, can produce a clear and high-contrast image without a double image, and a method for manufacturing the same.

  The photocurable optical resin composition according to the present invention includes a resin composition interposed between transparent substrates each having a light-shielding portion disposed opposite to each other, and the resin composition is cured to obtain a resin cured product. In this case, as the photocurable optical resin composition, (A) urethane (meth) acrylate having one or more ethylenically unsaturated bonds in the molecule, (B) plasticizer, (C) initiation of photopolymerization Agent, (D) a thiol compound represented by the following general formula (I), (A) component (A1) represented by the following general formula (II) having a weight average molecular weight of 1,000 to 5,000 And (A2) a mixture of urethane (meth) acrylates having a weight average molecular weight of 7,000 to 30,000.

（一般式（Ｉ）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子又は炭素数１〜５のアルキル基を示し、ｌは１〜６の整数を示し、Ａ^１はｌ価の有機機であり、ｍは０〜３の整数を示す。）

(In the general formula (I), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, 1 represents an integer of 1 to 6, and A ¹ represents a l-valent organic compound. And m represents an integer of 0 to 3.)

（一般式（ＩＩ）中、Ａ^２は重量平均分子量が５，０００以下のｎ価の有機基又は両末端がイソシアネート基を有するウレタンオリゴマー、Ａ^３は水素原子又は炭素数１〜５のアルキル基を示し、ｎは１又は２の整数を示す。）
これにより、光の当たらない遮光部分も硬化が可能となる。
（Ａ）成分に２種類以上の（メタ）アクリロイル基を有するウレタンオリゴマーを用いることにより、硬化性、密着性及び伸び率をより優れたものにすることができる。
また、前記光学用樹脂組成物は、（Ａ）成分の合計１００質量部に対し、（Ａ１）成分を２０〜６０質量部含むと好ましい。さらに、前記光学用樹脂組成物は、実質的に有機溶媒を含有せず、２５℃における粘度が５００〜５０００ｍＰａ・ｓであると好ましい。これにより、ブリードアウトを抑制でき、且つ、耐湿熱信頼性をより優れたものにすることができる。
また、前記光学用樹脂組成物は、（Ｂ）成分の可塑剤が、重量平均分子量１，０００〜２０，０００のポリオールであることがブリードアウトを抑制できる観点から好ましい。これにより、遮光部の硬化幅をより優れたものにすることができる。

(In the general formula (II), A ² is a urethane oligomer, A ³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms having a weight average molecular weight of 5,000 or less of n-valent organic group or both ends isocyanate groups And n represents an integer of 1 or 2.)
Thereby, the light-shielding part which does not receive light can also be hardened.
By using a urethane oligomer having two or more types of (meth) acryloyl groups as the component (A), the curability, adhesion and elongation can be further improved.
Moreover, it is preferable that the said optical resin composition contains 20-60 mass parts of (A1) components with respect to 100 mass parts of total of (A) component. Furthermore, it is preferable that the optical resin composition contains substantially no organic solvent and has a viscosity at 25 ° C. of 500 to 5000 mPa · s. Thereby, bleed-out can be suppressed and moisture-heat reliability can be further improved.
In the optical resin composition, the plasticizer of the component (B) is preferably a polyol having a weight average molecular weight of 1,000 to 20,000 from the viewpoint of suppressing bleed out. Thereby, the hardening width | variety of the light-shielding part can be made more excellent.

In addition, in the method for manufacturing an image display device according to the present invention, an image display unit having an image display unit and a protective panel are disposed to face each other, and the optical resin composition is interposed therebetween, thereby the optical resin composition. A method of manufacturing an image display device for curing an object, wherein the protective panel has a light shielding portion formed along an outer peripheral edge, and at least with respect to the optical resin composition between the image display unit and the protective panel Light irradiation is performed from the outer side surface side.
The image display device according to the present invention is manufactured by the method for manufacturing the image display device.

According to the present invention, the liquid is easy to handle at room temperature and is optically used in the space of the display device (between the protective panel and the liquid crystal display unit, between the protective panel and the touch panel, and between the touch panel and the liquid crystal display unit). In the manufacturing process of an image display device that is photocured after filling with the resin composition, even when there is a portion provided with a light-shielding portion, curing can be sufficiently advanced, excellent in heat and humidity resistance, and bleeding out. An optical resin composition that does not occur can be provided.
In addition, according to the present invention, it is possible to provide an image display device that has impact resistance, can produce a clear and high-contrast image without double image.

Hereinafter, the optical resin composition according to the present invention, the method for producing an image display device using the same, and the image display device will be described in detail by embodiments. In addition, this invention is not limited by this embodiment.
In this specification, “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto. Similarly, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, and “(meth) acryloyl” means “acryloyl” and corresponding “methacryloyl”.
The optical resin composition according to the present invention comprises (A) a urethane (meth) acrylate having one or more ethylenically unsaturated bonds in the molecule, (B) a plasticizer, (C) a photopolymerization initiator, (D) A compound represented by the following general formula (II) having a thiol compound represented by the following general formula (I), the component (A) having (A1) a weight average molecular weight of 1,000 to 5,000, and (A2) It consists of a mixture with urethane (meth) acrylate whose weight average molecular weight is 7,000-30,000.

（一般式（Ｉ）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子又は炭素数１〜５のアルキル基を示し、ｌは１〜６の整数を示し、Ａ^１はｌ価の有機機であり、ｍは０〜３の整数を示す。）

(In the general formula (I), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, 1 represents an integer of 1 to 6, and A ¹ represents a l-valent organic compound. And m represents an integer of 0 to 3.)

Hereinafter, each component will be described.
<(A) component: urethane (meth) acrylate having at least one ethylenically unsaturated bond in the molecule>
As a urethane (meth) acrylate having one or more ethylenically unsaturated bonds in the molecule, for example, a compound obtained by reacting (a1) a diol compound and (a2) a compound having an isocyanate group (hereinafter referred to as “a”) And (a3) a monohydroxy (meth) acrylate, or (a4) a monocarboxylic acid having a (meth) acryloyl group, or a monoisocyanate compound having a (meth) acryloyl group. It can be obtained by reacting.
(A1) Examples of the diol compound include polyolefin diols such as polyethylene glycol, polypropylene glycol, polybutadiene diol, polyisoprene diol, hydrogenated polybutadiene diol, hydrogenated polyisoprene diol, polyether diol, polyester diol, polycaprolactone diol, and silicone. Diol etc. are mentioned. Among these, polyolefin diol is particularly preferable from the viewpoints of curability and adhesion.
Examples of the compound (a2) having an isocyanate group include diisocyanate compounds represented by the following general formula (III).
OCN-X-NCO (III)
[In general formula (III), X represents a divalent organic group. ]
Examples of the divalent organic group represented by X in the general formula (III) include, for example, an alkylene group having 1 to 20 carbon atoms, an unsubstituted group, or a lower alkyl group having 1 to 5 carbon atoms such as a methyl group. And arylene groups such as a phenylene group and a naphthylene group. The number of carbon atoms of the alkylene group is more preferably 1-18. The divalent organic group represented by X has an aromatic ring such as a phenylene group, a xylylene group, a naphthylene group, a diphenylmethane-4,4′-diyl group, a diphenylsulfone-4,4′-diyl group. Groups are preferred. A hydrogenated diphenylmethane-4,4′-diyl group is also preferred.
Examples of the diisocyanates represented by the general formula (III) include diphenylmethane-2,4′-diisocyanate; 3,2′-, 3,3′-, 4,2′-, 4,3 ′. -, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate;3,2'-,3,3'-, 4,2 '-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate;3,2'-, 3, 3'-, 4,2'-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate; diphenylmethane -4,4'-diisocyanate;diphenylmethane-3,3'-diisocyanate;diphenylmethane-3,4'- Diphenylmethane diisocyanate compounds such as isocyanate and hydrogenated products thereof; diphenyl ether-4,4′-diisocyanate; benzophenone-4,4′-diisocyanate; diphenylsulfone-4,4′-diisocyanate; tolylene-2,4-diisocyanate; tolylene 2,6-diisocyanate; m-xylylene diisocyanate; p-xylylene diisocyanate; 1,5-naphthalene diisocyanate; 4,4 '-[2,2bis (4-phenoxyphenyl) propane] diisocyanate; tolylene diisocyanate; Hexamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; isophorone diisocyanate; 4,4'-dicyclohexylmethane diisocyanate; transcyclo Hexane-1,4-diisocyanate; hydrogenated m- xylylene diisocyanate, aliphatic or alicyclic isocyanates such lysine diisocyanate. Like these diisocyanates, it is preferable to use an aliphatic diisocyanate compound in which X in the general formula (III) is a group having an aliphatic group. These can be used alone or in combination of two or more. In addition, as a compound which has an isocyanate group, you may use trifunctional or more polyisocyanate with the diisocyanate represented by general formula (III).
The diisocyanates represented by the general formula (III) may be those stabilized with a blocking agent necessary for avoiding changes over time. Examples of the blocking agent include hydroxy acrylate, alcohol typified by methanol, phenol, oxime and the like, but there is no particular limitation.

The blending ratio when the (a1) diol compound and the diisocyanate represented by the general formula (III) are reacted is the number average molecular weight of the urethane oligomer to be produced and the terminal of the urethane oligomer to be produced is a hydroxyl group. Or an isocyanate group.
When the end of the urethane oligomer is an isocyanate group, the ratio of the number of isocyanate groups to the number of hydroxyl groups (number of isocyanate groups / number of hydroxyl groups) is preferably adjusted to be 1.01 or more, from the viewpoint of increasing the number average molecular weight. Is preferably adjusted to less than 2. By setting such a ratio, a urethane oligomer having an isocyanate group at the end can be obtained. Examples of the compound for introducing the (meth) acryloyl skeleton include (a3) monohydroxy (meth) acrylate compound.

  Examples of the (a3) monohydroxy (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 1,4-cyclohexanedimethanol. Mono (meth) acrylate, caprolactone or alkylene oxide adduct of each of the above (meth) acrylates, glycerin di (meth) acrylate, trimethylol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) Examples include acrylate, ditrimethylolpropane tri (meth) acrylate, and 2-acryloxyethanol. These monohydroxy compounds can be used alone or in combination of two or more.

On the other hand, when the terminal of the urethane oligomer is a hydroxyl group, it is preferable to adjust the blending ratio so that the ratio between the number of hydroxyl groups and the number of isocyanate groups (number of hydroxyl groups / isocyanate groups) is 1.01 or more. From the viewpoint of increasing, it is preferable to adjust to less than 2.
When the terminal of the urethane oligomer is a hydroxyl group, monocarboxylic acids having a (meth) acryloyl group such as (meth) acrylic acid, monoisocyanate compounds having a (meth) acryloyl group such as 2-isocyanatoethyl (meth) acrylate, etc. A urethane oligomer having two (meth) acryloyl groups can be obtained by reacting a compound capable of reacting with a hydroxyl group with a hydroxyl group at the terminal of the urethane oligomer.

In the present invention, the weight average molecular weight of the urethane (meth) acrylate as the component (A) is 1,000 to 30,000 from the viewpoints of curability, flexibility, workability, and wet heat resistance. Preferably, it is 2,000 to 25,000, more preferably 3,000 to 20,000.
In the present specification, the weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC) and converted to values using a standard polystyrene calibration curve. The number average molecular weight, weight average molecular weight, and molecular weight distribution (dispersion degree) are defined as follows.
(A) Number average molecular weight (Mn)
Mn = Σ (N _i M _i ) / ΣNi = ΣX _i M _i
(X _i = Mole fraction of molecules with molecular weight M _i = N _i / ΣN _i )
(B) Weight average molecular weight (Mw)
Mw = Σ (N _i M _i ² ) / ΣN _i M _i = ΣW _i M _i
(W _i = weight fraction of molecules of molecular weight M _i = N _i M _i / ΣN _i M _i )
(C) Molecular weight distribution (dispersion degree)
Dispersity = Mw / Mn

  In the optical resin composition of the present invention, the component (A) includes (A1) a compound represented by the following general formula (II) having a weight average molecular weight of 1,000 to 5,000, and (A2) a weight average. It consists of a mixture with urethane (meth) acrylate having a molecular weight of 7,000 to 30,000.

（一般式（ＩＩ）中、Ａ^２は重量平均分子量が５，０００以下のｎ価の有機基又は両末端がイソシアネート基を有するウレタンオリゴマー、Ａ^３は水素原子又は炭素数１〜５のアルキル基を示し、ｎは１又は２の整数を示す。）
一般式（ＩＩ）中のＡ^２は、重量平均分子量が５，０００以下のｎ価の有機基又は両末端がイソシアネート基を有するウレタンオリゴマーであり、重量平均分子量が、１，０００〜５，０００であるため、重量平均分子量が５，０００以下としている。上記の（ａ１）ジオール化合物と、（ａ２）イソシアネート基を有する化合物とを反応させて得られた化合物で、末端にイソシアネート基を有し、このイソシアネート基を除いたものに相当する。

(In the general formula (II), A ² is a urethane oligomer, A ³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms having a weight average molecular weight of 5,000 or less of n-valent organic group or both ends isocyanate groups And n represents an integer of 1 or 2.)
A ² in the general formula (II) is an n-valent organic group having a weight average molecular weight of 5,000 or less or a urethane oligomer having both ends having an isocyanate group, and the weight average molecular weight is 1,000 to 5,000. Therefore, the weight average molecular weight is set to 5,000 or less. This is a compound obtained by reacting the above (a1) diol compound and (a2) a compound having an isocyanate group, and corresponds to a compound having an isocyanate group at the terminal and excluding this isocyanate group.

In the present invention, (A) the content of urethane (meth) acrylate having one or more, preferably two or more ethylenically unsaturated bonds in the molecule is selected from the viewpoints of curability, adhesion and cure shrinkage ratio. 25-90 mass parts is preferable with respect to 100 mass parts of total amounts of A) component and (B) component, It is more preferable that it is 30-80 mass parts, It is especially preferable that it is 40-70 mass parts.
Moreover, as for (A1) component among (A) component, from a viewpoint of viscosity and heat-and-moisture heat reliability, (A1) component is 5-80 mass parts with respect to a total of 100 mass parts of (A) component. 10 to 70 parts by mass is more preferable, and 20 to 60 parts by mass is particularly preferable.

<(B) component: Plasticizer>
As the plasticizer of the component (B) in the present invention, for example, a polyester plasticizer of a dibasic acid and a polyhydric alcohol; a molecular chain of an acrylic acid alkyl ester monomer unit and / or a methacrylic acid alkyl ester monomer Acrylic plasticizer that is liquid from unit; Polyether plasticizer such as polypropylene glycol and its derivatives; Urethane plasticizer obtained from polyalkylene glycol and diisocyanate; Polystyrene plastic such as poly-α-methylstyrene and polystyrene Agents and the like.
Specifically, PPG3000 (trade name: Actol P-23; polyether polyol having a molecular weight of about 3000 manufactured by Mitsui Takeda Chemical Co., Ltd.), Exenol 5030 (polyether having a number average molecular weight of about 5100 manufactured by Asahi Glass Co., Ltd.) Polyol), Exenol 823 (a polyether triol having a number average molecular weight of about 5000 manufactured by Asahi Glass Co., Ltd.), an oxypropylene polymer having both ends of an allyl ether group, Mn = 5200, Mw / Mn = 1.6, and an acrylic resin ARUFON UP series (trade name, manufactured by Toa Gosei Co., Ltd.) which is a plasticizer is exemplified.

The weight average molecular weight of the (B) plasticizer used in the present invention is preferably 1,000 to 20,000, more preferably 2,000 to 15,000, from the viewpoint of suppressing bleeding out. It is especially preferable that it is 3,000-10,000.
In addition, the (B) plasticizer used in the present invention has a polyether skeleton such as a polyether polyol or a urethane-based plasticizer obtained from a polyalkylene glycol and diisocyanate from the viewpoint of further improving the curability of the light-shielding portion. A plasticizer having a polyether skeleton in which one terminal or both terminals are hydroxyl groups is particularly preferable.
Furthermore, as the plasticizer of the present invention, those having one (meth) acryloyl group in the molecule can be used as the plasticizer.
The content of the (B) plasticizer in the present invention is 10 to 60 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoints of curability, adhesion, and curing shrinkage. Preferably, it is 20 to 55 parts by mass, and particularly preferably 30 to 50 parts by mass.

<(C) component: photopolymerization initiator>
Examples of the photopolymerization initiator used in the present invention include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N-tetraethyl-4,4′-diaminobenzophenone, 4- Methoxy-4'-dimethylaminobenzophenone, α-hydroxyisobutylphenone, 2-ethylanthraquinone, t-butylanthraquinone, 1,4-dimethylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2- Methyl anthraquinone, 1,2-benzoanthraquinone, 2-phenylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy Aromatic ketone compounds such as -1,2-diphenylethane-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzoin methyl ether Benzoin ether compounds such as benzoin ethyl ether, benzoin isobutyl ether, benzoin phenyl ether, benzyl, 2,2-diethoxyacetophenone, benzyldimethyl ketal, ester compound of β- (acridin-9-yl) acrylic acid, 9-phenyl Acridine compounds such as acridine, 9-pyridylacridine, 1,7-diacridinoheptane, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5- Di (m-metoki Phenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p- Methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) 5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole Dimer, 2,4,5-triarylimidazole dimer such as 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer, 2-benzyl-2-dimethylamino-1- ( 4-Morpholinophenyl) -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propane, bis (2,4 , 6-trimethylbenzoyl) -phenylphosphine oxide, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone) and the like.

In particular, those that do not color the optical resin composition include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 1- [4- (2-hydroxyethoxy). ) -Phenyl] -2-hydroxy-2-methyl-1-propan-1-one, etc., α-hydroxyalkylphenone compounds, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2 , 6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, oligo (2-hydroxy-2- Methyl-1- (4- (1-methylvinyl) phenyl) propanone And a combination thereof are preferred.
In order to produce particularly thick sheets, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine A photopolymerization initiator containing an acyl phosphine oxide compound such as oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is preferable.
In order to reduce the odor of the sheet, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone) is preferable. A plurality of these photopolymerization initiators may be used in combination.
The content of the (C) photopolymerization initiator used in the present invention is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoint of curability. More preferably, it is 8-7 mass parts, and it is especially preferable that it is 1-4 mass parts.

<(D) Component: Thiol Compound Represented by General Formula (I)>
The component (D) in the present invention is not particularly limited as long as it is a compound represented by the general formula (I). However, from the viewpoint of the stability of the optical resin composition, m = 1 and R ¹ is A secondary thiol compound represented by the following general formula (IV), which is a methyl group and R ² is a hydrogen atom, is preferable.

（一般式（ＩＶ）中、Ａはｎ価の有機基を示し、ｎは１〜６の整数を示す。）
このような化合物としては、例えば、１，４−ビス（３−メルカプトブチリルオキシ）ブタン、１，３，５−トリス（３−メルカプトブチルオキシエチル）−１，３，５−トリアジン−２，４，６（１Ｈ，３Ｈ，５Ｈ）−トリオン、ペンタエリスリトールテトラキス（３−メルカプトブチレート)、トリス−［（３−メルカプトプロピオニルオキシ）−エチル］−イソシアヌレート、トリメチロールプロパントリス（３−メルカプトプロピオネート)、ペンタエリスリトールテトラキス（３−メルカプトプロピオネート）、ジペンタエリスリトールヘキサキス（３−メルカプトプロピオネート)等が挙げられる。これらの化合物のうち、安定性の観点から２級チオールである１，４−ビス（３−メルカプトブチリルオキシ）ブタン、１，３，５−トリス（３−メルカプトブチルオキシエチル）−１，３，５−トリアジン−２，４，６（１Ｈ，３Ｈ，５Ｈ）−トリオン、ペンタエリスリトールテトラキス（３−メルカプトブチレート)が好ましい。これらの化合物はカレンズＭＴシリーズとして、昭和電工株式会社から入手可能である。これらの化合物は、１種を単独で又は２種以上を組み合わせて用いることができる。

(In General Formula (IV), A represents an n-valent organic group, and n represents an integer of 1 to 6.)
Examples of such compounds include 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2, 4,6 (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate), tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, trimethylolpropane tris (3-mercaptopro Pionate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), and the like. Of these compounds, 1,4-bis (3-mercaptobutyryloxy) butane and 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3 which are secondary thiols from the viewpoint of stability , 5-triazine-2,4,6 (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate) are preferred. These compounds are available from Showa Denko KK as Karenz MT series. These compounds can be used individually by 1 type or in combination of 2 or more types.

  The content of the thiol compound represented by the general formula (I) as the component (D) in the present invention is 100 in terms of the total amount of the component (A) and the component (B) from the viewpoint of the curability of the light-shielding part and the wet heat resistance. 1-30 mass parts is preferable with respect to a mass part, It is more preferable that it is 2-25 mass parts, It is especially preferable that it is 3-10 mass parts.

A stabilizer and the like can be arbitrarily added to the optical resin composition of the present invention as necessary. The stabilizer is added for the purpose of improving the stability of the optical resin composition, and examples thereof include triphenyl phosphite.
Moreover, in this invention, it is preferable that an organic solvent is not included substantially from a viewpoint of heat-and-moisture resistance reliability and suppressing the bubble generation in hardened | cured material.
“Substantially” means that the organic resin is present in a trace amount (1% by mass or less) in the optical resin composition to such an extent that the post-curing properties of the optical resin composition of the present invention are not significantly deteriorated. It means that it may be good, but preferably it is not contained.

  The viscosity (25 ° C.) of the optical resin composition of the present invention is preferably 500 to 5,000 mPa · s, and preferably 2,000 to 4,000 mPa · s from the viewpoint of bleeding out and workability. Is more preferable. The viscosity is a value measured using an E-type viscometer (for example, RE-80L manufactured by Toki Sangyo Co., Ltd.).

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.
First, an example of producing an optical resin composition that can be used in an image display device to which the present invention is applied will be described below.

[Synthesis Example 1 (Synthesis of polyurethane acrylate)]
185 parts by mass of polypropylene glycol (molecular weight 3,000) in a reaction vessel equipped with a condenser, thermometer, stirrer, dropping funnel and air injection tube, 0.5 parts by mass of p-methoxyphenol as a polymerization inhibitor and dibutyl as a catalyst Take 0.05 parts by mass of tin dilaurate, raise the temperature to 70 ° C. while flowing air, and then stir at 70 to 75 ° C., 2-isocyanatoethyl methacrylate (Karenz MOI: trade name of Showa Denko KK) 19.2 mass Part was uniformly dropped over 2 hours to carry out the reaction.
When the reaction was allowed to proceed for 5 hours after completion of the dropping, the reaction was terminated by confirming that the isocyanate had disappeared as a result of IR measurement. Polyurethane methacrylate having a polymerizable unsaturated bond at both ends of polypropylene glycol (weight average molecular weight 3 , 300).

[Synthesis Example 2 (Synthesis of polyurethane acrylate)]
195 parts by mass of polypropylene glycol (molecular weight 3,000) in a reaction vessel equipped with a condenser, thermometer, stirrer, dropping funnel and air injection tube, 0.5 parts by mass of p-methoxyphenol as a polymerization inhibitor and dibutyl as a catalyst Take 0.05 parts by mass of tin dilaurate, raise the temperature to 70 ° C. while flowing air, and then stir at 70 to 75 ° C., 2-isocyanatoethyl methacrylate (Karenz MOI: Showa Denko Co., Ltd., trade name) 10.1 weight Part was uniformly dropped over 2 hours to carry out the reaction.
When the reaction was allowed to proceed for 5 hours after completion of the dropping, the reaction was terminated by confirming that the isocyanate had disappeared as a result of IR measurement. Polyurethane methacrylate having a polymerizable unsaturated bond at both ends of polypropylene glycol (weight average molecular weight 3 , 100).

[Synthesis Example 3 (Synthesis of polyurethane acrylate)]
180 parts by mass of polypropylene glycol (molecular weight 2,000), unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone (Placcel FA-2D: Daicel) in a reaction vessel equipped with a cooling tube, thermometer, stirring device, dropping funnel and air injection tube Chemical Industry Co., Ltd. trade name) 2.33 parts by mass, 0.5 parts by mass of p-methoxyphenol as a polymerization inhibitor and 0.05 parts by mass of dibutyltin dilaurate as a catalyst, and after raising the temperature to 70 ° C. while flowing air While stirring at 70 to 75 ° C., 22.2 parts by mass of trimethylhexamethylene diisocyanate was uniformly added dropwise over 2 hours to carry out the reaction.
When the reaction was completed for 5 hours after completion of the dropwise addition, the reaction was terminated by confirming that the isocyanate had disappeared as a result of IR measurement. Polypropylene glycol and trimethylhexamethylene diisocyanate were used as repeating units and polymerized at both ends. A polyurethane acrylate having a polymerizable unsaturated bond (weight average molecular weight 10,000) was obtained.

[Synthesis Example 4 (Synthesis of polyurethane acrylate)]
180 parts by mass of polypropylene glycol (molecular weight 2,000), unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone (Placcel FA-2D: Daicel) in a reaction vessel equipped with a cooling tube, thermometer, stirring device, dropping funnel and air injection tube Chemical Industry Co., Ltd. trade name) 2.33 parts by mass, 0.5 parts by mass of p-methoxyphenol as a polymerization inhibitor and 0.05 parts by mass of dibutyltin dilaurate as a catalyst, and after raising the temperature to 70 ° C. while flowing air While stirring at 70 to 75 ° C., 22.2 parts by mass of trimethylhexamethylene diisocyanate was uniformly added dropwise over 2 hours to carry out the reaction.
When the reaction was completed for 5 hours after completion of the dropwise addition, the reaction was terminated after confirming that the isocyanate had disappeared as a result of IR measurement. Polypropylene glycol and trimethylhexamethylene diisocyanate were used as repeating units and the terminal was polymerizable. A polyurethane acrylate having an unsaturated bond and a hydroxyl group (weight average molecular weight 10,000) was obtained.

[Synthesis Example 5 (Synthesis of polyurethane)]
185 parts by mass of polypropylene glycol (molecular weight 2,000) in a reaction vessel equipped with a cooling tube, a thermometer, a stirrer, a dropping funnel and an air injection tube, 0.5 parts by mass of p-methoxyphenol as a polymerization inhibitor and dibutyl as a catalyst Take 0.05 parts by weight of tin dilaurate, raise the temperature to 70 ° C. while flowing air, and then uniformly drop 4.9 parts by weight of trimethylhexamethylene diisocyanate over 2 hours while stirring at 70 to 75 ° C. Went.
When the reaction was completed for 5 hours after completion of the dropwise addition, the reaction was terminated by confirming that the isocyanate had disappeared as a result of IR measurement, and had polypropylene glycol and trimethylhexamethylene diisocyanate as repeating units, and a hydroxyl group at the end. Polyurethane having a weight average molecular weight of 10,000 was obtained.

Example 1
As component (A), 32 parts by mass of polyurethane acrylate obtained in Synthesis Example 1, 32 parts by mass of polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of polyurethane obtained in Synthesis Example 5 as Component (B), (C) Component As a diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (photopolymerization initiator) (product name: SPEDDCURE TPO) manufactured by LAMBSON, 1.0 part by mass, (D) as a component, pentaerythritol tetrakis (3- Mercaptobutyrate) (secondary thiol) (made by Showa Denko KK, trade name Karenz MT PE1), 15 parts by mass, was weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 1.

(Example 2)
3.5 parts by mass of polyurethane acrylate obtained in Synthesis Example 1, 60.5 parts by mass of polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) ) Phosphine oxide (photopolymerization initiator) (manufactured by LAMBSON, trade name SPEEDCURE TPO) 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (manufactured by Showa Denko KK, trade name) Karenz MT PE1) 15 parts by mass were weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 1.

(Example 3)
57 parts by mass of the polyurethane acrylate obtained in Synthesis Example 1, 7.0 parts by mass of the polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of the polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) phos Fin oxide (photopolymerization initiator) (LAMBSON, trade name SPEDCURE TPO) 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (Showa Denko K.K., trade name Karenz MT PE1) 15 parts by mass was weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 1.

Example 4
32 parts by mass of polyurethane acrylate obtained in Synthesis Example 2, 32 parts by mass of polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (Photoinitiator) (LAMBSON, trade name SPEDDCURE TPO) 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (Showa Denko Co., trade name Karenz MT PE1) 15 parts by mass was weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 1.

(Example 5)
32 parts by mass of polyurethane acrylate obtained in Synthesis Example 1, 32 parts by mass of polyurethane acrylate obtained in Synthesis Example 4, 20 parts by mass of polyurethane obtained in Synthesis Example 5, and diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (Photoinitiator) (LAMBSON, trade name SPEDDCURE TPO) 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (Showa Denko Co., trade name Karenz MT PE1) 15.0 parts by mass were weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 1.

(Example 6)
32 parts by mass of polyurethane acrylate obtained in Synthesis Example 1, 32 parts by mass of polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (Photopolymerization initiator) (LAMBSON, trade name SPEDDCURE TPO) 1.0 part by mass, 1,4-bis (3-mercaptobutyryloxy) butane (secondary thiol) (Showa Denko Co., Ltd., trade name) Karenz MT BD1) 15 parts by mass was weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 2.

(Example 7)
3.5 parts by mass of polyurethane acrylate obtained in Synthesis Example 1, 60.5 parts by mass of polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) ) Phosphine oxide (photopolymerization initiator) (manufactured by LAMBSON, trade name SPEDDCURE TPO) 1.0 part by mass, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine- 2,4,6 (1H, 3H, 5H) -trione (secondary thiol) (made by Showa Denko KK, trade name Karenz MT NR1) 15 parts by weight, weighed and mixed, and optical resin composition Adjusted. The evaluation results of this resin composition are shown in Table 2.

(Example 8)
57.0 parts by mass of the polyurethane acrylate obtained in Synthesis Example 1, 7.0 parts by mass of the polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of the polyurethane obtained in Synthesis Example 5, 1-hydroxy-cyclohexyl-phenyl-ketone (light Polymerization initiator) (BASF, trade name Irgacure 184) 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (Showa Denko Co., trade name Karenz MT PE1) 15 mass The optical resin composition was prepared by weighing and mixing with stirring. The evaluation results of this resin composition are shown in Table 2.

Example 9
32 parts by mass of polyurethane acrylate obtained in Synthesis Example 2, 32 parts by mass of polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of polyether polyol (trade name Exenol 823, manufactured by Asahi Glass Co., Ltd.), diphenyl- (2,4,6 -Trimethylbenzoyl) phosphine oxide (photopolymerization initiator) (product of LAMBSON, trade name SPEEDCURE TPO) 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (manufactured by Showa Denko KK) , 15 parts by mass of trade name Karenz MT PE1), weighed and mixed to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 2.

(Example 10)
32 parts by mass of the polyurethane acrylate obtained in Synthesis Example 1, 32 parts by mass of the polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of a non-functional acrylic polymer (trade name ARUFON UP-1000, manufactured by Toagosei Co., Ltd.), diphenyl- (2 , 4,6-trimethylbenzoyl) phosphine oxide (photopolymerization initiator) (product name: SPEDDCURE TPO) manufactured by LAMBSON, 1.0 part by mass, pentaerythritol tetrakis (3-mercaptobutyrate) (secondary thiol) (Showa) An optical resin composition was prepared by weighing 15 parts by mass of Denko Co., Ltd., trade name Karenz MT PE1), and stirring and mixing them. The evaluation results of this resin composition are shown in Table 2.

(Comparative Example 1)
64 parts by mass of the polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of the polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (photopolymerization initiator) (manufactured by LAMBSON, product) Name SPEDCURE TPO) 1.0 part by mass, 1,4-bis (3-mercaptobutyryloxy) butane (secondary thiol) (made by Showa Denko KK, trade name Karenz MT PE1) 15 parts by mass are weighed and stirred. The optical resin composition was prepared by mixing. The evaluation results of this resin composition are shown in Table 3.

(Comparative Example 2)
64 parts by mass of the polyurethane acrylate obtained in Synthesis Example 1, 20 parts by mass of the polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (photopolymerization initiator) (manufactured by LAMBSON, product) Name SPEDCURE TPO) 1.0 part by mass, 1,4-bis (3-mercaptobutyryloxy) butane (secondary thiol) (made by Showa Denko KK, trade name Karenz MT PE1) 15 parts by mass are weighed and stirred. The optical resin composition was prepared by mixing. The evaluation results of this resin composition are shown in Table 3.

(Comparative Example 3)
39.5 parts by mass of the polyurethane acrylate obtained in Synthesis Example 1, 39.5 parts by mass of the polyurethane acrylate obtained in Synthesis Example 3, 20 parts by mass of the polyurethane obtained in Synthesis Example 5, diphenyl- (2,4,6-trimethylbenzoyl) ) 1.0 part by mass of phosphine oxide (photopolymerization initiator) (manufactured by LAMBSON, trade name SPEEDCURE TPO) was weighed and mixed by stirring to prepare an optical resin composition. The evaluation results of this resin composition are shown in Table 3.

(viscosity)
The viscosity at 25 ° C. of the optical resin composition was measured using an E-type viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.). At this time, when the viscosity was 500 to 5,000 mPa · s, the wet spreadability was good and good (◯), and the other cases were evaluated as bad (×).
(Bleed-out / moisture heat resistance reliability)
The prepared optical resin composition is dropped onto a 2-inch glass substrate, another glass substrate is bonded through a 175 μm spacer, and ultraviolet rays are irradiated at 2,000 mJ / cm ² using an ultraviolet irradiation device. A test piece was obtained. At this time, a light shielding part having a width of 10 mm was formed on the outer periphery of the glass substrate on the ultraviolet irradiation side. When this substrate was put into a test bath of 85 ° C. and 85% RH for 500 hours and there was no change, the wet heat resistance was good (◯), and a bleed-out in which the resin composition protruded from between the substrates was observed. The case was evaluated as (x) because the wet heat resistance was insufficient.
(Curable)
The optical resin composition was dropped onto a glass substrate, a PET film was bonded so as to have a film thickness of 175 μm, and ultraviolet rays were irradiated at 2,000 mJ / cm ² using an ultraviolet irradiation device to prepare a transparent sheet. At this time, a light shielding part having a width of 60 mm was formed on the outer periphery of the PET film on the ultraviolet irradiation side. The curability of the obtained cured product was evaluated with a finger, and a film having excellent retention characteristics was evaluated as (◯), and a film that could not be formed was evaluated as (×). Moreover, about the light shielding part, the width | variety whose curability is ((circle)) similarly to the said evaluation was evaluated with a caliper. The larger the curing width, the better the characteristics.
(Curing shrinkage)
An optical resin composition is dropped on a PET film, and another PET film is bonded so as to have a film thickness of 175 μm, and an ultraviolet resin is irradiated to 2,000 mJ / cm ² for an optical resin composition. A transparent sheet having a cured product was prepared. The specific gravity of the transparent sheet and the optical resin composition before curing was measured using an electronic hydrometer (Alpha Mirage SD-200L), and the curing shrinkage was calculated from the following equation.
Curing shrinkage (%) = {(transparent sheet specific gravity−resin composition specific gravity) / transparent sheet specific gravity} × 100
At this time, when the cure shrinkage rate was 2.0% or less, the cure shrinkage amount was small and good (◯), and when it exceeded 2.0%, the cure shrinkage amount was large (x).
The test results of each example and comparative example are summarized in Table 1.

  From Table 1, when the optical resin composition (Examples 1 to 10) according to the present invention using two types of urethane (meth) acrylates having different weight average molecular weights is used, the optical resin composition outside the scope of the present invention is used. It can be seen that curing proceeds sufficiently even in the case of filling between the substrates having the light-shielding portions, as compared with the case (Comparative Examples 1 to 3). Moreover, it confirmed that there was no problem also in the viscosity stability of the hardened | cured material obtained at this time, a heat-and-moisture reliability test, an optical characteristic, a cure shrinkage rate, adhesiveness, and elongation rate. In Comparative Examples 1 and 2 using one type of urethane (meth) acrylate for the examples of the present invention, the generation of bleeding out and the curing shrinkage rate are large, and the comparison without using the thiol compound of component (D) In Example 3, it does not harden at the light shielding part.

Claims (5)

When a resin composition is interposed between transparent substrates having light-shielding portions on either side, and the resin composition is cured to form a cured resin, the resin composition is (A) intramolecular Including a urethane (meth) acrylate having one or more ethylenically unsaturated bonds, (B) a plasticizer, (C) a photopolymerization initiator, (D) a thiol compound represented by the following general formula (I), The component (A) is (A1) a compound represented by the following general formula (II) having a weight average molecular weight of 1,000 to 5,000, and (A2) a weight average molecular weight of 7,000 to 30,000. A photocurable optical resin composition characterized by using a mixture of a urethane (meth) acrylate.

(In the general formula (I), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, 1 represents an integer of 1 to 6, and A ¹ represents a l-valent organic compound. And m represents an integer of 0 to 3.)

(In the general formula (II), A ² is a urethane oligomer, A ³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms having a weight average molecular weight of 5,000 or less of n-valent organic group or both ends isocyanate groups And n represents an integer of 1 or 2.)   The optical resin composition according to claim 2, comprising 20 to 60 parts by mass of the component (A1) with respect to 100 parts by mass of the total of the component (A).   The optical resin composition according to claim 1 or 2, which contains substantially no organic solvent and has a viscosity at 25 ° C of 500 to 5000 mPa · s.   An image display unit having an image display unit and a protective panel are disposed to face each other, and the optical resin composition according to any one of claims 1 to 3 is interposed therebetween, and the optical resin composition is disposed. A method of manufacturing an image display device to be cured, wherein the protective panel has a light shielding portion formed along an outer peripheral edge, and at least outward from the optical resin composition between the image display unit and the protective panel. A method for manufacturing an image display device that performs light irradiation from a side surface.   An image display device manufactured by the method for manufacturing an image display device according to claim 4.