JPWO2015190571A1 - UV curable resin composition for touch panel, laminating method and article using the same - Google Patents

Abstract

Provided is an ultraviolet curable resin composition for a touch panel, which can provide an optical member such as a display unit having good productivity and good adhesion, and is excellent in workability. The resin layer applied on a flat surface is characterized in that the outermost surface of the resin layer when irradiated with ultraviolet rays forms irregularities of 1 μm or more, and preferably comprises a rubber component (a) and a non-rubber component (b). A resin composition used for laminating at least two optical substrates, the monofunctional (meth) acrylate (A) having a fatty chain having 8 to 30 carbon atoms, a softening component (B), photopolymerization And a photopolymerization initiator (E).

Description

  The present invention relates to an ultraviolet curable resin composition for bonding at least two optical substrates and a method for producing an optical member using the same.

  In recent years, display devices that allow screen input by attaching 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 are widely used. In this touch panel, a glass plate or a resin film on which a transparent electrode is formed is bonded with a slight gap facing each other. If necessary, a transparent protection made of glass or resin is provided on the touch surface. It has a structure in which plates are bonded together.

  There is a technique using a double-sided pressure-sensitive adhesive sheet for bonding a glass plate or film on which a transparent electrode is formed in a touch panel and a transparent protective plate made of glass or resin, or for bonding a touch panel and a display body unit. However, when a double-sided pressure-sensitive adhesive sheet is used, 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 flexible ultraviolet curable resin composition has been proposed.

On the other hand, Patent Document 1 is known as a conventional technique regarding a bonding technique in which a touch panel and a display unit are bonded with an ultraviolet curable adhesive. However, it has not been known so far what type of resin is suitable for such a two-stage curing process.
Further, as a conventional technique, the technique of Patent Document 2 is also known as a similar bonding technique. However, it has not been known what kind of resin is suitable for the process of laminating the optical base material after the resin is cured.

International Publication No. 2009/054168 Pamphlet International Publication No. 2013/168532 Pamphlet

  It is an object of the present invention to provide an ultraviolet curable resin composition for a touch panel that has excellent productivity, can provide an optical member such as a display unit having good curability and adhesion, and is excellent in workability. .

The present inventors have completed the present invention as a result of intensive studies in order to solve the above problems. That is, the present invention relates to the following (1) to (18).
(1) An ultraviolet curable resin composition for a touch panel, wherein the resin layer applied on a flat surface has an unevenness of 1 μm or more on the outermost surface of the resin layer when irradiated with ultraviolet rays.
(2) A resin composition containing a rubber component (a) and a non-rubber component (b) and used to bond at least two optical substrates, and having a monofunctional chain having 8 to 30 carbon atoms The ultraviolet curable resin composition for a touch panel according to (1), comprising (meth) acrylate (A), a softening component (B), a photopolymerizable oligomer (C), and a photopolymerization initiator (E).
(3) A monofunctional (meth) acrylate (A) having an aliphatic chain having 8 to 30 carbon atoms is represented by the following formula (10):

(In the above formula, R represents H or CH ₃ , and R ₂ represents an alkyl group having 8 to 20 carbon atoms.)
It is the ultraviolet curable resin composition for touch panels as described in (2), wherein the monofunctional (meth) acrylate (A) having an aliphatic chain having 8 to 30 carbon atoms represented by the above formula (10) is: The ultraviolet curable resin composition for touchscreens which is 35 weight% or less in a resin composition.
(4) The photopolymerizable oligomer (C) is selected from the group consisting of urethane (meth) acrylate, polyisoprene or (meth) acrylate having a hydrogenated polyisoprene skeleton, polybutadiene or (meth) acrylate having a hydrogenated polybutadiene skeleton. (2) or (3), the ultraviolet curable resin composition for touch panels (5), wherein the photopolymerizable oligomer (C) is polypropylene / polybutadiene / water. The ultraviolet curable resin composition for a touch panel as described in (4), which is a urethane (meth) acrylate having at least one skeleton selected from the group consisting of hydrogenated polybutadiene / polyisoprene / hydrogenated polyisoprene (6) Further contains a photopolymerizable monomer (D) other than the component (A), and (D) The following formula (1)

(In the formula, R ₁ represents a hydrogen atom or CH ₃ , and n represents an integer of 1 to 3)
The ultraviolet curable resin composition for a touch panel according to any one of (2) to (5), which is represented by:
(7) The ultraviolet curable resin composition for a touch panel as described in (6), wherein the formula (1) is 4-hydroxybutyl acrylate.
(8) The softening component (B) includes any one of a hydroxyl group-containing polymer and a liquid terpene-based resin, or both of them, as described in any one of (2) to (7) UV curable resin composition for touch panels.
(9) The touch panel according to any one of (2) to (8), comprising 1 to 30% by weight of a monofunctional (meth) acrylate (A) having a branched chain and having a C8 to C30 fatty chain. UV curable resin composition.
(10) The photopolymerizable monomer (D) other than the component (A) is further contained, and the component (D) contains a photopolymerizable monomer having no hydroxyl group. The ultraviolet curable resin composition for touchscreens of description.
(11) The monofunctional (meth) acrylate (A) having a branched C8-C30 fatty chain contains isostearyl acrylate, any one of (1) to (10) The ultraviolet curable resin composition for touchscreens as described in an item.
(12) A method for producing an optical member in which at least two optical substrates having the following steps 1 and 2 are pasted together.
(Step 1) The ultraviolet curable resin composition for a touch panel according to any one of (1) to (11) is applied to at least one optical substrate to form an application layer, and the application Step of obtaining an optical substrate having a cured product layer by irradiating the layer with ultraviolet rays (Step 2) The other optical substrate is bonded to the cured product layer of the optical substrate obtained in Step 1, Or the process (13) of bonding the hardened | cured material layer of the other optical base material obtained by the process 1 The hardened | cured material layer obtained by the said process 1 exists in the optical base material side, and the optical base material side And the uncured part existing on the opposite side of the manufacturing method according to (12).
(14) After the said process 1-2, it has the following process 3 further, The manufacturing method as described in (13) characterized by the above-mentioned.
(Step 3) A step of irradiating the cured product layer having an uncured portion in the bonded optical substrate with ultraviolet rays to cure the cured product layer (15) The ultraviolet curable resin composition is irradiated in the step 1 (12) to (14), wherein the maximum illuminance in the range of 200 to 320 nm is 30 or less, where the maximum illuminance in the range of 320 to 450 nm is 100. The manufacturing method of the optical member of description.
(16) When the maximum illuminance in the range of 320 nm to 450 nm is 100, the maximum illuminance in the range of 200 to 320 nm is 10 or less when the ultraviolet ray irradiated to the ultraviolet curable resin composition in the step 1 is 100. (12) The manufacturing method of the optical member as described in any one of (14) characterized by the above-mentioned.
(17) A cured product obtained by irradiating the ultraviolet curable resin composition according to any one of (1) to (11) with active energy rays.
(18) A touch panel comprising the ultraviolet curable resin composition according to any one of (1) to (11).

It is process drawing which shows 1st Embodiment of the manufacturing method of this invention. It is process drawing which shows 2nd Embodiment of the manufacturing method of this invention. It is process drawing which shows 3rd Embodiment of the manufacturing method of this invention. It is process drawing which shows 4th Embodiment of the manufacturing method of this invention. It is the schematic of the optical member obtained by this invention. Hardened resin layer obtained by the method for measuring surface irregularities described in Examples

First, the ultraviolet curable resin composition of this invention is demonstrated. The phrase “can be added to an ultraviolet curable resin composition used for optics” means that an additive that lowers the transparency of the cured product to an extent that it cannot be used for optics is not included. In the present specification, “(meth) acrylate” means either one or both of methacrylate and acrylate. The same applies to “(meth) acrylic acid” and the like. “Acrylate” represents only acrylate and excludes methacrylate.
In the ultraviolet curable resin composition used in the present invention, when a cured sheet having a thickness after curing of 200 μm is prepared, the average transmittance of the sheet with light having a wavelength of 400 to 800 nm is: At least 90%.

The ultraviolet curable resin composition for a touch panel of the present invention is characterized in that the outermost surface of the resin layer when irradiated with ultraviolet rays has irregularities of 1 μm or more. Thus, having a certain level of irregularities on the outermost surface of the cured resin layer increases the surface area of the resin layer surface when bonded to an optical base material, so that a strong adhesion can be exerted. .
Here, the unevenness on the outermost surface is preferably 3 μm or more, and more preferably 5 μm or more. In addition, the width | variety of an unevenness | corrugation here is measured by the length of the bottom face of the arbitrary recessed part on a hardened | cured material layer, and the vertex of the arbitrary convex part on a hardened | cured material layer. The measurement method can be measured using a laser displacement meter or a microscope.
The density of the protrusions is preferably 0.5 or more, preferably 1 or more, per horizontal distance of 1000 μm. Also in the concave portion, the density is preferably 0.5 or more per horizontal distance of 1000 μm, and preferably one or more.
The curing of the resin layer is not particularly limited as long as it is irradiated with ultraviolet rays. However, the resin layer has the unevenness in a state where the curing rate is set to 10% or more, more preferably 30% or more, and particularly preferably 50% or more. It is preferable. Thus, by providing unevenness with a high curing rate, it is possible to achieve a high adhesion effect with a large surface area while reducing the risk of the resin layer being crushed when bonded to an optical substrate. Although an upper limit is not specifically limited, Preferably it is 90% or less, More preferably, it is 80% or less.
In addition, when cured at a curing rate of 30% to 90%, unevenness tends to be formed if left for several minutes. Therefore, when the curing rate is 30% to 90% and 30 seconds to 5 minutes after curing, the unevenness can be easily increased, and after 10 minutes, the unevenness can be further increased.

  In order to obtain such a resin composition that expresses unevenness, it can be achieved by containing two components having low compatibility. As a specific example, it can be expressed by using (a) a rubber component and (b) a non-rubber component in combination.

(A) As an example of the rubber component, (meth) acrylate having a rubber component skeleton is preferable. Specifically, (meth) acrylate having a urethane skeleton, (meth) acrylate having an isoprene skeleton, (meth) acrylate having a butadiene skeleton, (meth) acrylate having a styrene / butadiene skeleton, (meth) having a chloroprene skeleton Rubber-like skeletons such as acrylate, (meth) acrylate having an isoprene-butadiene skeleton, (meth) acrylate having a hydrogenated polybutadiene skeleton, (meth) acrylate having a hydrogenated terpene skeleton, and (meth) acrylate having a terpene skeleton It is mentioned to use the compound which has. Since such a component has a high solubility parameter, the above unevenness can be formed by using it together with a substance having a low solubility parameter. Although it does not specifically limit as a solubility parameter, It is preferable that it is 7.0-15.0 by SP value, It is more preferable that it is 8.5-15.0, It is 9.0-15.0 Is particularly preferred.

By using such a rubber component, the dielectric constant of the resin composition can be lowered.
Among them, by using a compound having a high solubility parameter, the compatibility with other components is reduced and the above unevenness is easily formed. Therefore, in the (meth) acrylate having a rubber component skeleton, A (meth) acrylate having a skeleton having a rubber component is preferred. Specifically, (meth) acrylate having a hydrogenated polybutadiene skeleton, (meth) acrylate having a hydrogenated polyisoprene skeleton, and (meth) acrylate having a hydrogenated terpene skeleton are preferable.
Furthermore, it is preferable to use urethane (meth) acrylate from the viewpoint of increasing the solubility parameter and reducing the compatibility with other components. Furthermore, from the viewpoint of further reducing compatibility, urethane (meth) acrylate having a hydrogenated polybutadiene skeleton, urethane (meth) acrylate having a hydrogenated polyisoprene skeleton, and urethane having a hydrogenated terpene skeleton as urethane (meth) acrylate. (Meth) acrylate is particularly preferred. Such urethane (meth) acrylate can be obtained by the method described later.

The ultraviolet curable resin composition for a touch panel of the present invention is a resin composition used for bonding at least two optical substrates, and is (b) a (meth) acrylate having no rubber component as a non-rubber component. If there is no particular limitation. For example, (b) non-rubber components include photopolymerizable oligomers and (meth) acrylate monomers described below. Especially, it is preferable to contain the monofunctional (meth) acrylate (A) which has a C8-C30 fatty chain. More preferably, it is 16-25. Thus, the long chain monofunctional (meth) acrylate decreases as the SP value becomes longer, so the difference in SP value from the rubber component increases, and the compatibility is lowered to form more irregularities. This is because it can be made easier. (B) The solubility parameter of the non-rubber component is preferably 3.0 to 8.5, more preferably 3.0 to 8.0.
Specific examples of the (meth) acrylate that can be used as the monofunctional (meth) acrylate (A) having a fatty chain having 8 to 30 carbon atoms include, for example, octyl (meth) acrylate, isooctyl (meth) acrylate, and decyl (meth). Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, isolauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cetyl (meth) acrylate, isocetyl (meth) acrylate, behenyl (meth) acrylate , Isobehenyl (meth) acrylate, and the like. Examples of commercially available products include isostearyl acrylate manufactured by Shin-Nakamura Chemical Co., Ltd .; light acrylate IS-A manufactured by Kyoeisha Chemical Co., Ltd., and the like.
Furthermore, by using a (meth) acrylate having a long-chain fatty chain, it functions as a mediator that enhances compatibility with the softening component (B) or the polymerizable oligomer (C), and is allowed to stand for a long time. In addition, it is possible to effectively prevent the insoluble component from being precipitated. Further, it is possible to obtain a resin composition having a low dielectric constant while ensuring flexibility.
Here, as the suitable (a) rubber component and (b) non-rubber component, it is preferable to use (b) a non-rubber component having an SP value lower than that of the (a) rubber component. The SP value of the rubber component (a) used in combination with the (b) non-rubber component having an SP value of 3.0 to 8.5 is preferably 7.0 to 15.0, It is more preferably 8.5 to 15.0, and particularly preferably 9.0 to 15.0. Further, the SP value of the rubber component (a) used in combination with the (b) non-rubber component having an SP value of 3.0 to 8.0 as the SP value is preferably 7.0 to 15.0, 8.5 to 15.0 is more preferable, and 9.0 to 15.0 is particularly preferable.

  As monofunctional (meth) acrylate (A) which has a C8-C30 fatty chain which the ultraviolet curable resin composition for touchscreens of this invention can contain, following formula (10)

(In the above formula, R represents H or CH ₃ , and R ₂ represents an alkyl group having 8 to 30 carbon atoms.)
It is preferable to use a monofunctional (meth) acrylate represented by: Here, the number of carbon atoms in _{R 2} is more preferably 10 to 20, particularly preferably 15 to 20.
By using the monofunctional (meth) acrylate of the above formula (10), unevenness can be easily formed, and flexibility and reactivity can be improved. Of these, isostearyl acrylate is more preferable from the viewpoints of low volatility, reactivity, and flexibility.
The monofunctional (meth) acrylate represented by the above formula (10) is preferably 35% by weight or less, more preferably 30% by weight or less, and more preferably 20% by weight or less in the ultraviolet curable resin composition for touch panel. It is particularly preferred that

Here, from the viewpoint of improving compatibility while ensuring transparency by avoiding white turbidity of the resin composition itself, MR represents the number of R ₂ alkyl groups in the above formula (10), and formula (1) described later. In the compound represented by the formula (1), it is preferable that a certain ratio is exhibited when the total number of carbon atoms excluding the acryloyl group is MC and the number of branched carbon chains is MB. Specifically, it is preferably a resin composition containing both compounds such that MR / (MC + MB) (hereinafter referred to as a special ratio) is 5.5 or less, and particularly preferably 5 or less. preferable. Further, from the viewpoint of making the whitening resistance particularly excellent, the resin composition contains both compounds having the low volatility / whitening resistance acrylate and the special ratio of 5.5 or less. It is preferably 5 or less.

In the present invention, from the viewpoint of facilitating the formation of irregularities by lowering compatibility, (meth) acrylate having a urethane skeleton, (meth) acrylate having a hydrogenated polybutadiene skeleton, and (meth) having a hydrogenated polyisoprene skeleton A combination of one or more (meth) acrylates selected from the group consisting of acrylates and (meth) acrylates having a hydrogenated terpene skeleton, and (meth) acrylates described in the above formula (10) is preferable.
In addition, from the viewpoint of facilitating the formation of unevenness, it comprises urethane (meth) acrylate having a hydrogenated polybutadiene skeleton, urethane (meth) acrylate having a hydrogenated polyisoprene skeleton, and urethane (meth) acrylate having a hydrogenated terpene skeleton. A combination of one or more (meth) acrylates selected from the group and the (meth) acrylate represented by the above formula (10), or a (meth) acrylate having a hydrogenated polybutadiene skeleton and a hydrogenated polyisoprene skeleton ( (Meth) acrylate, one or more (meth) acrylates selected from the group consisting of (meth) acrylates having a hydrogenated terpene skeleton, and (meth) acrylates in which R2 is an alkyl group of 15 or more in the above formula (10) A combination is more preferred.
In particular, from the viewpoint of facilitating the formation of irregularities, it comprises urethane (meth) acrylate having a hydrogenated polybutadiene skeleton, urethane (meth) acrylate having a hydrogenated polyisoprene skeleton, and urethane (meth) acrylate having a hydrogenated terpene skeleton. A combination of one or more (meth) acrylates selected from the group and (meth) acrylate in which R2 is an alkyl group of 15 or more in the above formula (10) is very preferable.
As a preferable combination of solubility parameters, (a) a rubber component having an SP value of 8.5 to 15.0 and (b) a non-rubber component having an SP value of 3.0 to 8.0 are preferable, and an SP value of 8 More preferred are (a) a rubber component of 5 to 15.0 and (b) a non-rubber component having an SP value of 3.0 to 7.5.

The content of the component (A) in the composition is usually 1 to 90% by weight, preferably about 1 to 80% by weight.
Here, the content is preferably 1 to 40% by weight or less, and more preferably 1 to 30% by weight or less. By being in this range, the compatibility with the softening component (B) and the photopolymerizable oligomer (C) described later is improved, and while providing flexibility, the function of suppressing the improvement of the dielectric constant is achieved, This is because precipitation / precipitation of insoluble components can be effectively prevented, and the resin composition can be prevented from being too low in polarity.

  In this invention, it is preferable to use the photopolymerizable monomer which does not have a hydroxyl group as the photopolymerizable monomer (D) mentioned later used together with (A) component. Thus, by using together the photopolymerizable monomer which does not have a hydroxyl group, it becomes possible to suppress that polarity is raised too much and to suppress polarity to a certain level. Furthermore, it is easy to obtain a resin composition that hardly contains moisture. As such a photopolymerizable monomer having no hydroxyl group, one obtained by removing a photopolymerizable monomer having a hydroxyl group from a photopolymerizable monomer (D) described later can be used.

The ultraviolet curable resin composition for a touch panel of the present invention preferably contains a softening component (B). The softening component (B) is not cross-linked by ultraviolet rays, and exists between the photopolymerizable oligomers or photopolymerizable monomers, thereby providing flexibility and reducing the shrinkage rate. Have. Moreover, it also has a function of improving adhesion by, for example, imparting stickiness.
As such a softening component (B), a polymer, oligomer, phthalate ester, phosphate ester, glycol ester, citrate ester, aliphatic dibasic acid ester compatible with the composition, Examples include fatty acid esters, epoxy plasticizers, castor oils, terpene resins, hydrogenated terpene resins, and liquid terpenes. Examples of the oligomer and polymer include polyisoprene skeleton, hydrogenated polyisoprene skeleton, polybutadiene skeleton, hydrogenated polybutadiene skeleton or xylene skeleton oligomer and polymer, esterified product thereof, adipic acid ester oligomer, polybutene and the like. be able to. From the viewpoint of transparency, hydrogenated terpene resins, hydrogenated polyisoprene, hydrogenated polybutadiene, polybutene, and liquid terpenes are preferable. Furthermore, from the viewpoint of adhesive strength and compatibility with other materials, hydrogenated terpene resins containing hydroxyl groups at the ends or side chains, hydrogenated polyisoprenes containing hydroxyl groups at the ends or side chains, hydroxyl groups terminated Alternatively, hydroxyl group-containing polymers such as hydrogenated polybutadiene contained in the side chain, and liquid terpene resins are particularly preferable.

  The weight ratio of the softening component in the ultraviolet curable resin composition can be used regardless of whether the softening component (B) is solid or liquid. The softening component is usually 5 to 70% by weight, preferably 10 to 10%. 60% by weight. Moreover, a solid softening component is 5 to 40 weight% normally, Preferably it is 10 to 35 weight%. The liquid softening component is usually 10 to 70% by weight, preferably 20 to 60% by weight.

  The ultraviolet curable resin composition of the present invention preferably contains a photopolymerizable oligomer (C). Although it does not specifically limit as a photopolymerizable oligomer (C) in the ultraviolet curable resin composition of this invention, The (meth) acrylate, polybutadiene, or hydrogenation which has urethane (meth) acrylate, polyisoprene, or hydrogenated polyisoprene frame | skeleton. It is preferable to use one selected from the group consisting of (meth) acrylates having a polybutadiene skeleton. Among them, urethane (meth) acrylate is preferable from the viewpoint of adhesive strength, and has at least one skeleton selected from the group consisting of polybutadiene / hydrogenated polybutadiene / polyisoprene / hydrogenated polyisoprene from the viewpoint of moisture resistance. Urethane (meth) acrylate is more preferable.

  The urethane (meth) acrylate is obtained by reacting a polyhydric alcohol, a polyisocyanate, and a hydroxyl group-containing (meth) acrylate.

  Examples of the polyhydric alcohol include polybutadiene glycol, hydrogenated polybutadiene glycol, polyisoprene glycol, hydrogenated polyisoprene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, ethylene glycol, propylene glycol, 1,4 -Cyclic skeletons such as alkylene glycols having 1 to 10 carbon atoms such as butanediol and 1,6-hexanediol, triols such as trimethylolpropane and pentaerythritol, tricyclodecanedimethylol, and bis- [hydroxymethyl] -cyclohexane Alcohols, and the like; and polybasic acids such as succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride, etc. Polyester polyol obtained by reaction, caprolactone alcohol obtained by reaction of polyhydric alcohol and ε-caprolactone, polycarbonate polyol (for example, polycarbonate diol obtained by reaction of 1,6-hexanediol and diphenyl carbonate, etc.) or polyether polyol (For example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-modified bisphenol A, etc.) and the like. From the viewpoint of adhesive strength and moisture resistance, the polyhydric alcohol is preferably propylene glycol, polybutadiene glycol, hydrogenated polybutadiene glycol, polyisoprene glycol, or hydrogenated polyisoprene glycol, and weight average molecular weight from the viewpoint of transparency and flexibility. Is particularly preferably propylene glycol having a viscosity of 2000 or more, hydrogenated polybutadiene glycol, or hydrogenated polyisoprene glycol. Hydrogenated polybutadiene glycol is preferred from the viewpoints of discoloration such as heat-resistant coloring and compatibility. The upper limit of the weight average molecular weight at this time is not particularly limited, but is preferably 10,000 or less, and more preferably 5000 or less. Moreover, you may use together 2 or more types of polyhydric alcohol as needed.

  Examples of the organic polyisocyanate include isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, dicyclopentanyl isocyanate, and the like. Among these, isophorone diisocyanate is preferable from the viewpoint of toughness.

  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, a hydroxyl group terminal polyalkylene glycol (meth) acrylate, etc. can be used.

  Reaction for obtaining the said urethane (meth) acrylate 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 the said urethane (meth) acrylate, about 7000-100000 are preferable and 10000-60000 are more preferable. When the weight average molecular weight is less than 7000, shrinkage increases, and when the weight average molecular weight is greater than 100,000, curability is poor.

  In the ultraviolet curable resin composition of this invention, urethane (meth) acrylate can be used 1 type or in mixture of 2 or more types by arbitrary ratios. The weight ratio of urethane (meth) acrylate in the photocurable resin composition of the present invention is usually 5 to 90% by weight, preferably 10 to 50% by weight.

The (meth) acrylate having the polyisoprene skeleton has a (meth) acryloyl group at the terminal or side chain of the polyisoprene molecule. (Meth) acrylate having a polyisoprene skeleton can be obtained as UC-203, UC102, or UC-1 (manufactured by Kuraray Co., Ltd.). The (meth) acrylate having a polyisoprene skeleton preferably has a polystyrene-equivalent number average molecular weight of 1,000 to 50,000, more preferably about 25,000 to 45,000.
The weight ratio of the (meth) acrylate having a polyisoprene skeleton in the photocurable resin composition of the present invention is usually 5 to 90% by weight, preferably 10 to 50% by weight.

  The ultraviolet curable resin composition of the present invention contains a photopolymerizable monomer (D). As the photopolymerizable monomer (D), a (meth) acrylate having one (meth) acryloyl group in the molecule can be preferably used. Here, the photopolymerizable monomer (D) excludes (meth) acrylate having urethane (meth) acrylate, polyisoprene or hydrogenated polyisoprene skeleton, (meth) acrylate having polybutadiene or hydrogenated polybutadiene skeleton ( (Meth) acrylate is shown.

  As a photopolymerizable monomer (D) contained in the ultraviolet curable resin composition of the present invention, the following formula (1)

(In the formula, R ₁ represents a hydrogen atom or CH ₃ , and n represents an integer of 1 to 3)
The monofunctional acrylate represented by these can be used conveniently.
As the composition ratio of the ultraviolet curable resin composition, the monofunctional acrylate represented by the above formula (1) is preferably 1 to 20% by weight, the photopolymerizable oligomer (C) is 5 to 90% by weight, and the formula Photopolymerizable monomer (D) other than (1) is 5 to 90% by weight, photopolymerization initiator (E) is 0.1 to 5% by weight, and other components are the balance.

The monofunctional acrylate (A) represented by the formula (1) in the ultraviolet curable resin composition of the present invention includes 4-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl. An acrylate etc. are mentioned, You may use 2 or more types together as needed. Here, in the formula (1), when n is 2 or less (particularly when n is 1 or less), R ₁ is preferably a methyl group. When n is 3 or more, R ₁ is preferably a hydrogen atom. In the formula (1), a total carbon number of 2 or more is preferable because a resin composition with low volatility and low cloudiness can be obtained. Above all, from the viewpoint of adhesive strength and whitening resistance, the following formula (2)

(In the formula, n represents an integer of 2 to 4)
The monofunctional acrylate represented by these is preferable. Examples of the monofunctional acrylate represented by the formula (2) include 4-hydroxybutyl acrylate, 3-hydroxypropyl acrylate, and 2-hydroxyethyl acrylate. Furthermore, 4-hydroxybutyl acrylate is particularly preferable from the viewpoint of low volatility. When a methacrylate resin is used, the curing rate tends to be slow, and when the resin composition is actually used, it takes time to cure, which is not preferable.
Here, in the compound represented by the formula (1), when the total carbon number excluding the acryloyl group is MC, the number of OH groups is MOH, and the number of carbon branch chains is MB, the MOH / (MC + MB) is preferably 0.3 or less, particularly preferably 0.28 or less, and particularly preferably 0.25 or less. By being in such a range, since it becomes high molecular weight to a certain extent, it can suppress volatilization and white turbidity, and it can be realized that it works advantageously to prevent whitening prevention by hydroxyl groups. Hereinafter, the monofunctional acrylate represented by the formula (1) that satisfies the condition is referred to as a low volatility / whitening-resistant acrylate.

The content of the photopolymerizable monomer represented by the formula (1) is preferably 1 to 20% by weight, more preferably 2 to 10% by weight, and particularly preferably 5.5 to 8% by weight. When the content of the component of formula (1) is less than 1%, the whitening resistance is lowered. On the other hand, when the content is 20% by weight or more, bubbles may easily enter during bonding, or the compatibility with other components may deteriorate and the liquid may become cloudy.
In the present invention, it is not preferable that the ultraviolet curable resin composition contains a hydroxyl group-containing methacrylate because some of the properties such as a decrease in the curing rate and whitening resistance are adversely affected. When the methacrylate having a hydroxyl group is contained, the content is preferably 10% by weight or less, particularly preferably 5% by weight or less.

  Specific examples of the (meth) acrylate having one (meth) acryloyl group in the molecule other than the photopolymerizable monomer represented by the formula (1) include isooctyl (meth) acrylate and isoamyl (meth) acrylate. , Lauryl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, cetyl (meth) acrylate, isomyristyl (meth) acrylate, isostearyl (meth) acrylate, tridecyl (meth) acrylate, etc. 25 alkyl (meth) acrylates, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acryloylmorpholine, phenylglycidyl (meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl acetate Rate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 1-adamantyl methacrylate, polypropylene oxide-modified nonylphenyl (meth) acrylate, (meth) acrylate having a cyclic skeleton such as dicyclopentadieneoxyethyl (meth) acrylate, and alkyl (meth) acrylate having 5 to 7 carbon atoms having a hydroxyl group , Ethoxydiethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, etc. Lucylene glycol (meth) acrylate, ethylene oxide modified phenoxylated phosphoric acid (meth) acrylate, ethylene oxide modified butoxylated phosphoric acid (meth) acrylate and ethylene oxide modified octyloxylated phosphoric acid (meth) acrylate, caprolactone modified tetrafurfuryl (meth) An acrylate etc. can be mentioned.

The composition of the present invention can contain (a (meth) acrylate other than a (meth) acrylate having one (meth) acryloyl group in the molecule) 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 this invention, when using together, in order to suppress cure shrinkage, it is preferable to use mono- or bifunctional (meth) acrylate.

  In the ultraviolet curable resin composition of this invention, these (meth) acrylate monomer components can be used 1 type or in mixture of 2 or more types by arbitrary ratios. The weight ratio of the photopolymerizable monomer (D) other than the formula (1) in the photocurable transparent resin composition of the present invention is usually 5 to 90% by weight, preferably 10 to 50% by weight. When it is less than 5% by weight, the curability is poor, and when it is more than 90% by weight, shrinkage increases.

  In the present invention, the ratio (weight ratio) of the component of formula (1) to the component of formula (10) is preferably in the range of 1: 2 to 1:25, particularly in the range of 1: 3 to 1:15. preferable.

  Epoxy (meth) acrylate can be used for the ultraviolet curable resin composition of this invention 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. The weight average molecular weight of the epoxy (meth) acrylate is preferably 500 to 10,000.
The weight ratio of the epoxy (meth) acrylate in the ultraviolet curable resin composition of the present invention is usually 1 to 80% by weight, preferably 5 to 30% by weight.

  The photopolymerization initiator (E) contained in the composition of the present invention is not particularly limited, and examples thereof include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2,4,6-trimethylbenzoylphenylethoxyphosphine. Fin oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone ( Irgacure 184; manufactured by BASF), 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer (Esacure ONE; manufactured by Lambarti), 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 (Irgacure 651; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocur 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-acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester mixture (Irgacure 754; manufactured by BASF), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2 -Chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone and the like can be mentioned.

In the present invention, in the photopolymerization initiator (E), the molar extinction coefficient at 302 nm or 313 nm measured in acetonitrile or methanol is 300 ml / (g · cm) or more, and the molar extinction coefficient at 365 nm is 100 ml. It is preferable to use a photopolymerization initiator that is not more than / (g · cm). By using such a photopolymerization initiator, it is possible to contribute to an improvement in adhesive strength. When the molar extinction coefficient at 302 nm or 313 nm is 300 ml / (g · cm) or more, curing at the time of curing in the following step 3 is sufficient. On the other hand, when the molar extinction coefficient at 365 nm is 100 ml / (g · cm) or less, excessive curing can be appropriately suppressed at the time of curing in the following step 1, and adhesion can be improved.
Examples of such a photopolymerization initiator (E) include 1-hydroxycyclohexyl phenyl ketone (Irgacure 184; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocur 1173). Manufactured by BASF), 1- [4- (2-hydroxyethoxy) -phenyl-]-2-hydroxy-2-methyl-1-propan-1-one (Irgacure 2959; manufactured by BASF), phenylglyoxylic acid And methyl ester (Darocur MBF; manufactured by BASF).

  In the ultraviolet curable resin composition of this invention, these photoinitiators (E) can be used 1 type or in mixture of 2 or more types by arbitrary ratios. The weight ratio of the photopolymerization initiator (E) in the photocurable resin composition of the present invention is usually 0.2 to 5% by weight, preferably 0.3 to 3% by weight. When it is more than 5% by weight, when obtaining a cured product layer having a cured part and an uncured part on the side opposite to the optical substrate side, the uncured part cannot be formed or the transparency of the resin cured product layer is low. There is a risk of getting worse.

  The ultraviolet curable resin composition of this invention can contain the additive etc. which are mentioned later as another component.

  Furthermore, amines that can serve as photopolymerization initiation assistants can be used in combination with the 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 0.005 to 5% by weight, preferably 0.01 to 3% by weight.

  In the ultraviolet curable resin composition of the present invention, an antioxidant, an organic solvent, a silane coupling agent, a polymerization inhibitor, a leveling agent, an antistatic agent, a surface lubricant, a fluorescent whitening agent, and a light stabilizer are optionally added. You may add additives, such as an agent (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-benzotriazole-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.

  When present in the composition of various additives, the weight ratio of the various additives in the photocurable transparent resin composition is 0.01 to 3% by weight, preferably 0.01 to 1% by weight, more preferably 0.02 to 0.5% by weight.

  The ultraviolet curable resin composition of the present invention can be obtained by mixing and dissolving the aforementioned components at room temperature to 80 ° C., and if necessary, impurities may be removed by an operation such as filtration. In the adhesive resin composition of the present invention, it is preferable to appropriately adjust the compounding ratio of components so that the viscosity at 25 ° C. is in the range of 300 to 40,000 mPa · s in view of applicability.

Next, the preferable form of the manufacturing process of the optical member using the ultraviolet curable resin composition of this invention is demonstrated.
In the method for producing an optical member of the present invention, it is preferable that at least two optical substrates are bonded together by the following (Step 1) to (Step 3). If it is determined that sufficient adhesive strength can be secured at the stage of (Process 2), (Process 3) can be omitted.
(Step 1) By applying the ultraviolet curable resin composition to at least one optical substrate to form a coating layer, and irradiating the coating layer with ultraviolet rays, an optical group in the coating layer is formed. A cured portion (hereinafter referred to as “cured portion of the cured product layer” or simply “cured portion”) present on the material side (lower side of the coating layer) and the side opposite to the optical substrate side (upper side of the coating layer) Step of obtaining an optical substrate having a cured product layer having an uncured portion (hereinafter, referred to as “uncured portion of the cured product layer” or simply “uncured portion”) present on the atmosphere side. In Step 1, there is no particular limitation on the curing rate of the coating layer after ultraviolet irradiation, and there is an uncured portion on the surface opposite to the optical substrate side (the upper side of the coating layer, usually the air side). All you have to do is After irradiation with ultraviolet rays, when the opposite side (the upper side of the coating layer, usually the atmosphere side) of the optical substrate is touched with a finger and a liquid component adheres to the finger, it can be determined that it has an uncured portion.
(Step 2) Another optical substrate is bonded to the uncured portion of the cured product layer of the optical substrate obtained in Step 1, or the other optical substrate obtained in Step 1 is cured. The process of bonding the uncured part of the material layer.
(Process 3) The process of irradiating an ultraviolet-ray through the optical base material which has a light-shielding part to the hardened | cured material layer which has the unhardened part in the bonded optical base material, and hardening this hardened | cured material layer.
A specific embodiment of the optical member manufacturing method of the present invention that goes through steps 1 to 3 will be described below with reference to the drawings, taking as an example the bonding of a liquid crystal display unit and a transparent substrate having a light shielding portion. To do.
Here, when the two or more substrates are bonded together, the ultraviolet curable resin composition of the present invention is applied in a liquid resin state to at least one substrate and is liquid to the other substrate. In the case of being cured by ultraviolet rays after being bonded together in a resin state or a state having an uncured portion, particularly excellent adhesive effect can be obtained and air can be prevented, so that it is particularly useful in such a case. preferable.

(First embodiment)
FIG. 1 is a process diagram showing a first embodiment of a production process of an optical member using the ultraviolet curable resin composition of the present invention.
This method is a method of obtaining an optical member by bonding the liquid crystal display unit 1 and the transparent substrate 2 together.
The liquid crystal display unit 1 is a liquid crystal display unit in which a liquid crystal material is sealed between a pair of substrates on which electrodes are formed, and a polarizing plate, a driving circuit, a signal input cable, and a backlight unit are provided.
The transparent substrate 2 is a transparent substrate such as a glass plate, a polymethyl methacrylate (PMMA) plate, a polycarbonate (PC) plate, an alicyclic polyolefin polymer (COP) plate, an acrylic resin, or polyethylene terephthalate. The transparent substrate may be subjected to hard coat treatment or antireflection treatment on one side or both sides.
Here, the transparent substrate 2 having a black frame-shaped light-shielding portion 4 on the surface of the transparent substrate can be preferably used, and the light-shielding portion 4 is formed by applying a tape, applying a paint, printing, or the like. In the present invention, the present invention can also be applied to a device that does not have the light shielding portion 4. However, in the following description of the first to third embodiments, a case where the light shielding portion 4 is provided will be described as a specific example. In the case where the light-shielding portion 4 is not provided, “transparent substrate having a light-shielding portion” can be read as “transparent substrate”, and can be considered as an example in which the light-shielding portion is not provided as it is.

(Process 1)
First, as shown to Fig.1 (a), an ultraviolet curable resin composition is apply | coated to the surface of the surface in which the light-shielding part of the transparent substrate 2 which has the display surface of the liquid crystal display unit 1 and a light-shielding part is formed. Examples of the coating method include a slit coater, a roll coater, a spin coater, and a screen printing method. Here, the ultraviolet curable resin composition applied to the surface of the liquid crystal display unit 1 and the transparent substrate 2 having the light shielding portion may be the same, or different ultraviolet curable resin compositions may be used. Usually, it is preferable that both are the same ultraviolet curable resin composition. Here, when the light shielding layer is provided on the transparent substrate 2, it is preferable that the resin composition reaches the light shielding layer by filling the difference in height between the substrate and the light shielding layer.
The film thickness of the cured product of each ultraviolet curable resin is adjusted so that the cured resin layer 7 after bonding is 50 to 500 μm, preferably 50 to 350 μm, and more preferably 100 to 350 μm. Here, although the film thickness of the cured layer of the ultraviolet curable resin existing on the surface of the transparent substrate 2 having the light-shielding portion depends on the film thickness, the ultraviolet curable resin usually existing on the surface of the liquid crystal display unit 1 is used. It is preferable that the thickness is equal to or thicker than the thickness of the cured product layer of the mold resin. This is to minimize the portion that remains uncured even after irradiation with ultraviolet rays in Step 3 described later, thereby eliminating the risk of curing failure.

The ultraviolet curable resin composition layer 5 after application is irradiated with ultraviolet rays 8 and a cured portion (in the drawing, the liquid crystal display unit side or the transparent substrate side as viewed from the ultraviolet curable resin composition) is present (in the figure). Curing with uncured parts (not shown in the figure) present on the upper side of the coating layer (on the opposite side of the liquid crystal display unit side or on the opposite side of the transparent substrate side) (on the atmospheric side when performed in the atmosphere) A physical layer 6 is obtained. The irradiation amount is preferably 5 to 2000 mJ / cm ² , and particularly preferably 10 to 1000 mJ / cm ² . If the amount of irradiation is too small, the degree of cure of the resin of the optical member that is finally bonded may be insufficient. If the amount of irradiation is too large, the amount of uncured components decreases, and the liquid crystal display unit 1 and the light-shielding portion There is a possibility that the bonding of the transparent substrate 2 will be defective.
In the present invention, “uncured” refers to a fluid state in a 25 ° C. environment. In addition, when the resin composition layer is touched with a finger after ultraviolet irradiation and a liquid component adheres to the finger, it is determined to have an uncured portion.
For curing by ultraviolet irradiation from ultraviolet to near ultraviolet, 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.
In step 1 of the present invention, the wavelength of the ultraviolet ray irradiated to the ultraviolet curable resin composition is not particularly limited, but when the maximum illuminance in the range of 320 nm to 450 nm is 100, the ratio of the maximum illuminance at 200 to 320 nm. The (illuminance ratio) is preferably 30 or less, and particularly preferably the illuminance at 200 to 320 nm is 10 or less.
When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the ratio of maximum illuminance (illuminance ratio) in 200 to 320 nm is higher than 30, the adhesive strength of the optical member finally obtained will be inferior. This is because if the illuminance at a low wavelength is high, the curing of the ultraviolet curable resin composition proceeds excessively at the time of curing in the step 1, and the contribution to the adhesion at the time of curing in the ultraviolet irradiation in the step 3 is reduced. This is thought to be due to this.
Here, the method of irradiating ultraviolet rays so as to achieve the above illuminance ratio is, for example, a method of applying a lamp satisfying the illuminance ratio as a lamp that irradiates ultraviolet to near-ultraviolet rays, or the lamp itself has the illuminance. Even if the above condition is not satisfied, such illuminance can be obtained by using a base material (for example, a short wave ultraviolet cut filter, a glass plate, a film, etc.) that cuts short wavelength ultraviolet rays at the time of irradiation in step 1. Irradiation at a ratio is possible. Although it does not specifically limit as a base material which adjusts the illumination intensity ratio of an ultraviolet-ray, For example, the glass plate, soda-lime glass, PET film etc. which were given the short wave ultraviolet-ray cut process are mentioned. Incidentally, an attenuation plate or the like in which the surface of the quartz glass or the like has been subjected to uneven treatment is not very effective. Since these scatter the light and reduce the illuminance, they are not suitable for selectively reducing the illuminance at a short wavelength of 320 nm or less.
In step 1, irradiation with ultraviolet rays is usually carried out in the air at the upper surface on the coating side (on the opposite side of the liquid crystal display unit side or on the transparent substrate side as seen from the ultraviolet curable resin composition) (normal atmospheric surface) ). Further, ultraviolet irradiation may be performed while spraying a curing-inhibiting gas on the upper surface of the coating layer after evacuation. When the resin composition is cured in the atmosphere, the side opposite to the liquid crystal display unit side or the side opposite to the transparent substrate side is the atmosphere side. In addition, when it is desired to improve the tackiness of the surface of the coating layer formed in step 1, ultraviolet rays may be irradiated in a vacuum environment or in a gas environment that does not cause hardening inhibition such as nitrogen.
On the other hand, when step 3 is omitted, curing can be suitably performed in a vacuum or while spraying a gas (for example, nitrogen) that promotes curing. Thereby, even if the step 3 is omitted, sufficient adhesion can be performed.

The state of the uncured portion and the film thickness of the uncured portion can be adjusted by spraying oxygen or ozone onto the surface of the ultraviolet curable resin layer (coating layer) during the ultraviolet irradiation.
That is, when oxygen or ozone is sprayed on the surface of the coating layer, oxygen inhibition of curing of the ultraviolet curable resin composition occurs on the surface, so that the uncured portion of the surface can be ensured or the uncured portion The film thickness can be increased.

(Process 2)
Next, as shown in FIG. 1B, the liquid crystal display unit 1 and the transparent substrate 2 having a light shielding portion are bonded together so that the uncured portions face each other. Bonding can be performed either in air or in vacuum.
Here, in order to prevent bubbles from being generated during bonding, it is preferable to perform bonding in a vacuum.
As described above, when a cured product of an ultraviolet curable resin having a cured portion and an uncured portion is obtained on each of the liquid crystal display unit and the transparent substrate, the adhesion can be improved.
Bonding can be performed by pressing, pressing, or the like.

(Process 3)
Next, as shown in FIG.1 (c), the optical member obtained by bonding the transparent substrate 2 and the liquid crystal display unit 1 is irradiated with the ultraviolet-ray 8 from the transparent substrate 2 side which has a light-shielding part, and ultraviolet curable type The resin composition (coating layer) is cured.
The dose of ultraviolet rays about 100~4000mJ / cm ² is preferably in accumulated light amount, particularly preferably about 200~3000mJ / cm ^2. The light source used for curing by irradiation with ultraviolet to near ultraviolet light may be any light source as long as it is a lamp that emits ultraviolet to near ultraviolet light. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, or electrodeless lamp can be used.
In this way, an optical member as shown in FIG. 5 can be obtained.

(Second Embodiment)
In addition to the first embodiment, the optical member of the present invention may be manufactured by the second modified embodiment described below. Note that the details in each step are the same as those in the first embodiment, and therefore, the description of the same parts is omitted.

(Process 1)
First, as shown to Fig.2 (a), after apply | coating an ultraviolet curable composition to the surface in which the light-shielding part 4 was formed on the transparent substrate 2 which has a light-shielding part, the obtained coating layer (ultraviolet curable type) was obtained. The resin composition layer 5) is irradiated with ultraviolet rays 8, and the cured portion present on the lower side of the coating layer (on the transparent substrate side as viewed from the ultraviolet curable resin composition) and the upper side of the coating layer (opposite of the transparent substrate side) The hardened | cured material layer 6 which has the unhardened part which exists in the side) is obtained. Here, when the light shielding layer is provided on the transparent substrate 2, it is preferable that the resin composition reaches the light shielding layer by filling the difference in height between the substrate and the light shielding layer.
At this time, the wavelength of the ultraviolet ray irradiated to the ultraviolet curable resin composition is not particularly limited, but when the maximum illuminance in the range of 320 nm to 450 nm is 100, the ratio of the maximum illuminance at 200 to 320 nm is preferably 30 or less. Particularly preferably, the illuminance at 200 to 320 nm is 10 or less. When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the ratio of the maximum illuminance at 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior.

(Process 2)
Next, as shown in FIG. 2B, a transparent substrate 2 having a liquid crystal display unit 1 and a light shielding portion in a form in which the uncured portion of the obtained cured product layer 6 and the display surface of the liquid crystal display unit 1 face each other. Paste. Bonding can be performed either in air or in vacuum.

(Process 3)
Next, as shown in FIG. 2C, the optical member obtained by laminating the transparent substrate 2 and the liquid crystal display unit 1 is irradiated with ultraviolet rays 8 from the transparent substrate 2 side having a light-shielding portion, so that an ultraviolet curable type is obtained. The cured product layer 6 having an uncured portion of the resin composition is cured.

  In this way, the optical member shown in FIG. 5 can be obtained.

(Third embodiment)
FIG. 3 is a process diagram showing a third embodiment of a method for producing an optical member using the ultraviolet curable resin composition of the present invention. Note that the details in each step are the same as those in the first embodiment, and therefore, the description of the same parts is omitted.
In addition, the same code | symbol is attached | subjected in the figure about the same member as the structural member in 1st Embodiment mentioned above, and the description is not repeated here.

(Process 1)
First, as shown in FIG. 3A, the ultraviolet curable composition was applied to the surface of the liquid crystal display unit 1. Thereafter, the ultraviolet curable resin composition layer 5 is irradiated with ultraviolet rays 8, and the lower side 8 of the coating layer 8 and the cured portion present on the transparent substrate side as viewed from the ultraviolet curable resin composition, and the upper side of the coating layer ( A cured product layer 6 having an uncured portion present on the side opposite to the transparent substrate side is obtained.
At this time, the wavelength of the ultraviolet ray irradiated to the ultraviolet curable resin composition is not particularly limited, but when the maximum illuminance in the range of 320 nm to 450 nm is 100, the maximum illuminance at 200 to 320 nm is preferably 30 or less. The illuminance at 200 to 320 nm is preferably 10 or less. When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the maximum illuminance at 200 to 320 nm is higher than 30, the adhesive strength of the optical member finally obtained is inferior.

(Process 2)
Next, as shown in FIG. 3B, the liquid crystal display unit 1 is formed such that the uncured portion of the obtained cured product layer 6 and the surface on which the light shielding portion on the transparent substrate 2 having the light shielding portion is formed face each other. And a transparent substrate 2 having a light shielding portion are bonded together. Bonding can be performed either in air or in vacuum.

(Process 3)
Next, as shown in FIG. 3C, the optical member obtained by laminating the transparent substrate 2 and the liquid crystal display unit 1 is irradiated with ultraviolet rays 8 from the transparent substrate 2 side having a light-shielding portion, thereby ultraviolet curing type. The cured product layer 6 having an uncured portion of the resin composition is cured.

  In this way, the optical member shown in FIG. 5 can be obtained.

(Fourth embodiment)
In addition to the first embodiment, the optical member of the present invention may be manufactured by the following modified fourth embodiment. Note that the details in each step are the same as those in the first embodiment, and therefore, the description of the same parts is omitted. The fourth embodiment is described based on the second embodiment in which the step 3 is omitted, but the omission can be performed in the first to third embodiments.

(Process 1)
First, as shown to Fig.4 (a), after apply | coating an ultraviolet curable composition to the surface in which the light-shielding part 4 was formed on the transparent substrate 2 which has a light-shielding part, the obtained coating layer (ultraviolet curable type) was obtained. The resin composition layer 5) is irradiated with ultraviolet rays 8, and the cured portion present on the lower side of the coating layer (on the transparent substrate side as viewed from the ultraviolet curable resin composition) and the upper side of the coating layer (opposite of the transparent substrate side) The hardened | cured material layer 6 which has the unhardened part which exists in the side) is obtained. Here, when the light shielding layer is provided on the transparent substrate 2, it is preferable that the resin composition reaches the light shielding layer by filling the difference in height between the substrate and the light shielding layer.
At this time, the wavelength of the ultraviolet ray irradiated to the ultraviolet curable resin composition is not particularly limited, but when the maximum illuminance in the range of 320 nm to 450 nm is 100, the ratio of the maximum illuminance at 200 to 320 nm is preferably 30 or less. Particularly preferably, the illuminance at 200 to 320 nm is 10 or less. When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the ratio of the maximum illuminance at 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior.

(Process 2)
Next, as shown in FIG. 4B, the transparent substrate 2 having the liquid crystal display unit 1 and the light-shielding portion in a form in which the uncured portion of the obtained cured product layer 6 and the display surface of the liquid crystal display unit 1 face each other. Paste. Bonding can be performed either in air or in vacuum.

  In this way, the optical member shown in FIG. 5 can be obtained.

In each of the above embodiments, some of the embodiments of the method for producing an optical member of the present invention are described with one specific optical base material. In each embodiment, a liquid crystal display unit and a transparent substrate having a light shielding portion are used. However, in the manufacturing method of the present invention, various members described later as the optical base material can be used instead of the liquid crystal display unit, and various members described later as the optical base material are also used for the transparent substrate. be able to.
In addition, as an optical substrate such as a liquid crystal display unit and a transparent substrate, these various members are further bonded to another optical substrate layer (for example, a film bonded with a cured layer of an ultraviolet curable resin composition). Or what laminated | stacked the other optical base material layer) may be used.
Furthermore, the coating method of the ultraviolet curable resin composition described in the section of the first embodiment, the film thickness of the cured resin, the irradiation amount and light source at the time of ultraviolet irradiation, and oxygen on the surface of the ultraviolet curable resin layer In addition, any method for adjusting the film thickness of the uncured portion by spraying nitrogen or ozone is not applied only to the above-described embodiment, but can be applied to any manufacturing method included in the present invention.

Specific modes of the optical members that can be manufactured in the first to third embodiments including the liquid crystal display unit will be described below.
(I) At least one selected from the group consisting of an optical substrate having a light-shielding portion, a transparent glass substrate having a light-shielding portion, a transparent resin substrate having a light-shielding portion, and a glass substrate on which the light-shielding portion and the transparent electrode are formed. The optical base material is an optical base material, and the optical base material bonded thereto is at least one display unit selected from the group consisting of a liquid crystal display unit, a plasma display unit, and an organic EL unit. The aspect which is a display body unit which has an optical base material to have.
(Ii) One optical base material is a protective base material having a light-shielding part, and another optical base material bonded to it is a touch panel or a display unit having a touch panel, and at least two optical base materials are bonded. A mode in which the optical member is a touch panel having a protective base material having a light-shielding portion or a display unit having the same.
In this case, in Step 1, the ultraviolet curable resin composition is applied to either the surface of the protective base material having the light shielding portion, the touch surface of the touch panel, or both of them. It is preferable to apply.
(Iii) One optical substrate is an optical substrate having a light-shielding portion, the other optical substrate bonded to it is a display unit, and an optical member having at least two optical substrates bonded thereto The aspect which is a display body unit which has an optical base material which has a light-shielding part.
In this case, in the step 1, the ultraviolet curable resin is applied to either the surface of the optical substrate having the light shielding portion on the side where the light shielding portion is provided, the display surface of the display unit, or both of them. It is preferable to apply the composition.
Specific examples of the optical substrate having a light shielding part include a display screen protective plate having a light shielding part, or a touch panel provided with a protective substrate having a light shielding part.
For example, when the optical substrate having the light-shielding portion is a protective plate for a display screen having the light-shielding portion, the surface of the optical substrate having the light-shielding portion is provided on the side on which the light-shielding portion is provided. It is the surface on the side where the part is provided. In addition, when the optical substrate having the light shielding portion is a touch panel having a protective substrate having the light shielding portion, the surface having the light shielding portion of the protective substrate having the light shielding portion is bonded to the touch surface of the touch panel. The surface of the optical substrate having the light shielding portion on the side where the light shielding portion is provided means the substrate surface of the touch panel opposite to the touch surface of the touch panel.
The light-shielding part of the optical base material having the light-shielding part may be at any position of the optical base material, but is usually created in a frame shape around the optical base material in the form of a transparent plate or sheet, and its width is The thickness is about 0.5 mm to 10 mm, preferably about 1 to 8 mm, more preferably about 2 to 8 mm.

The ultraviolet curable resin composition of the present invention produces an optical member by bonding at least two optical base materials by the above (Step 1) to (Step 2) and, if necessary, (Step 3). Can be used in the way.
The curing shrinkage of the cured product of the ultraviolet curable resin composition of the present invention is preferably 4.0% or less, and particularly preferably 3.0% 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 substrate such as glass is thin, when the curing shrinkage rate is large, since the warpage during curing becomes large, the display performance is greatly adversely affected. Is preferred.

It is preferable that the transmittance | permeability in 400 nm-800 nm of the hardened | cured material of the ultraviolet curable resin composition of this invention is 90% or more. This is because when the transmittance is less than 90%, it is difficult for light to pass therethrough and the visibility is lowered 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 ultraviolet curable resin composition of the present invention can be suitably used as an adhesive for producing an optical member by laminating a plurality of optical substrates by the above (Step 1) to (Step 3).
Examples of the optical substrate used in the method for producing an optical member of the present invention include a transparent plate, a sheet, a touch panel, and a display unit.
In the present invention, the “optical substrate” means both an optical substrate having no light shielding part on the surface and an optical substrate having a light shielding part on the surface. In the method for producing an optical member of the present invention, preferably, at least one of a plurality of optical base materials used is an optical base material having a light shielding portion.
The position of the light shielding part in the optical substrate having the light shielding part is not particularly limited. As a preferred embodiment, a band-shaped light-shielding portion having a width of 0.05 to 20 mm, preferably about 0.05 to 10 mm, more preferably about 0.1 to 6 mm is formed on the periphery of the optical substrate. Is the case. The light-shielding portion on the optical substrate can be formed by attaching a tape, applying a coating or printing.

  Various materials can be used as the material of the optical substrate used in the present invention. Specifically, resins such as PET, PC, PMMA, a composite of PC and PMMA, glass, COC, COP, plastic (such as acrylic resin), and the like can be given. As an optical substrate used in the present invention, for example, a transparent plate or sheet, a sheet or transparent plate obtained by laminating a plurality of films or sheets such as polarizing plates, a non-laminated sheet or transparent plate, and a transparent made from inorganic glass Plates (inorganic glass plates and processed products thereof, such as lenses, prisms, ITO glass) and the like can be used. The optical substrate used in the present invention is a laminate composed of a plurality of functional plates or sheets (hereinafter referred to as “functional laminate”) such as a touch panel (touch panel input sensor) or the following display unit in addition to the polarizing plate described above. Also called "body").

Examples of the sheet that can be used as the optical substrate used in the present invention include an icon sheet, a decorative sheet, and a protective sheet. Examples of the plate (transparent plate) that can be used in the method for producing an optical member of the present invention include a decorative plate and a protective plate. As materials for these sheets or plates, those listed as materials for transparent plates can be applied.
Examples of the material of the touch panel surface that can be used as the optical substrate used in the present invention include glass, PET, PC, PMMA, a composite of PC and PMMA, COC, and COP.
The thickness of a plate-like or sheet-like optical substrate such as a transparent plate or a sheet is not particularly limited, and is usually about 5 μm to 5 cm, preferably about 10 μm to 10 mm, more preferably about 50 μm to 3 mm. Is the thickness.

As a preferable optical member obtained by the production method of the present invention, a plate-shaped or sheet-shaped transparent optical base material having a light-shielding portion and the functional laminate are cured products of the ultraviolet curable resin composition of the present invention. The optical member bonded together can be mentioned.
Further, in the manufacturing method of the present invention, a display unit with an optical functional material (by using a display unit such as a liquid crystal display device as one of optical substrates and an optical functional material as another optical substrate ( Hereinafter, it is also referred to as a display panel). Examples of the display unit include display devices such as LCD, EL display, EL illumination, electronic paper, and plasma display in which a polarizing plate is attached to glass. Further, 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 panel input sensors.

When it is used as an adhesive that bonds an optical substrate, it is preferable that the refractive index of the cured product is 1.45 to 1.55 in order to improve the visibility because the visibility of the display image is further improved.
Within the range of the refractive index, the difference in refractive index from the base material used as the optical base material can be reduced, and the light loss can be reduced by suppressing the irregular reflection of light.

Preferred embodiments of the optical member obtained by the production method of the present invention include the following (i) to (vii).
(I) The optical member which bonded together the optical base material which has a light-shielding part, and the said functional laminated body using the hardened | cured material of the ultraviolet curable resin composition of this invention.
(Ii) An optical base selected from the group consisting of a transparent glass substrate having a light shielding part, a transparent resin substrate having a light shielding part, and a glass substrate on which a light shielding material and a transparent electrode are formed, as the optical base material having the light shielding part. The optical member according to (i), which is a material and the functional laminate is a display unit or a touch panel.
(Iii) The optical member according to (ii), wherein the display unit is any one of a liquid crystal display unit, a plasma display unit, and an organic EL display unit.
(Iv) A touch panel (or touch panel input sensor) in which a plate-shaped or sheet-shaped optical substrate having a light-shielding portion is bonded to the surface on the touch surface side of the touch panel using the cured product of the ultraviolet curable resin composition of the present invention. ).
(V) A display panel in which a plate-like or sheet-like optical substrate having a light-shielding portion is bonded onto the display screen of the display unit using the cured product of the ultraviolet curable resin composition of the present invention.
(Vi) The display panel according to (v) above, wherein the plate-shaped or sheet-shaped optical substrate having a light-shielding portion is a protective substrate or a touch panel for protecting the display screen of the display unit.
(Vii) The ultraviolet curable resin composition according to any one of (i) to (vi), wherein the ultraviolet curable resin composition is the ultraviolet curable resin composition according to any one of (1) to (11). The optical member, touch panel or display panel described.

By using the ultraviolet curable resin composition of the present invention, a plurality of optical base materials selected from the above optical base materials are bonded together by the method described in (Step 1) to (Step 3). The optical member of the invention is obtained. In the step 1, the ultraviolet curable resin composition may be applied to only one of the surfaces facing each other through the cured product layer in the two optical substrates to be bonded, or may be applied to both surfaces. good.
For example, in the case of the optical member according to the above (ii) in which the functional laminate is a touch panel or a display unit, in Step 1, any one surface of the protective base material having a light shielding part, preferably the light shielding part is provided. The resin composition may be applied to only one of the provided surface and the touch surface of the touch panel or the display surface of the display unit, or may be applied to both of them.
In the case of the optical member of (vi) described above in which a protective base material or a touch panel for protecting the display screen of the display body unit is bonded to the display body unit, in Step 1, a light shielding portion of the protective base material is provided. The resin composition may be applied to only one of the substrate surface opposite to the surface or the touch surface of the touch panel and the display surface of the display unit, or to both of them.

  The optical member including the display unit knit obtained by the manufacturing method of the present invention and the optical base material having the light shielding portion can be incorporated into an electronic device such as a television, a small game machine, a mobile phone, and a personal computer.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Synthesis example 1
GI-2000 manufactured by Nippon Soda Co., Ltd. (iodine value: 12.2, hydroxyl value: 46.8 mg · KOH) as a hydrogenated polybutadiene polyol compound was added to a reactor equipped with a reflux condenser, a stirrer, a thermometer, and a temperature controller. / G) is 569.73 g (0.24 mol), 7.50 g (0.0024 mol) of Exenol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg · KOH / g) manufactured by Asahi Glass Co., Ltd. as a diol compound is polymerizable. 171.49 g of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd. as a compound and 0.41 g of 4-methoxyphenol as a polymerization inhibitor were added and stirred until uniform, and the internal temperature was 50 ° C. did. Subsequently, 80.03 g (0.36 mol) of isophorone diisocyanate was added as a polyisocyanate compound and reacted at 80 ° C. until the target NCO content was reached. Next, 28.70 g (0.247 mol) of 2-hydroxyethyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd. is used as the (meth) acrylate compound having at least one hydroxyl group, and 0 octylate tin is used as the urethanization reaction catalyst. .20 g was added and reacted at 80 ° C., and the point where the NCO content was 0.1% or less was set as the end point of the reaction, to obtain a polyurethane compound (E-1).

Synthesis example 2
GI-2000 manufactured by Nippon Soda Co., Ltd. (iodine value: 12.2, hydroxyl value: 46.8 mg · KOH) as a hydrogenated polybutadiene polyol compound was added to a reactor equipped with a reflux condenser, a stirrer, a thermometer, and a temperature controller. / G) is 545.99 g (0.23 mol), 7.19 g (0.0023 mol) of Exenol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg · KOH / g) manufactured by Asahi Glass Co., Ltd. as a diol compound is polymerizable. 208.51 g of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd. as a compound and 0.37 g of 4-methoxyphenol as a polymerization inhibitor were added and stirred until uniform, and the internal temperature was 50 ° C. did. Subsequently, 61.35 g (0.28 mol) of isophorone diisocyanate was added as a polyisocyanate compound and reacted at 80 ° C. until the target NCO content was reached. Next, 11.00 g (0.095 mol) of 2-hydroxyethyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd. is used as the (meth) acrylate compound having at least one hydroxyl group, and 0 octylate is used as the urethanization reaction catalyst. .20 g was added and reacted at 80 ° C., and the point where the NCO content became 0.1% or less was set as the end point of the reaction to obtain a polyurethane compound (E-2).

Synthesis example 3
In a reactor equipped with a reflux condenser, a stirrer, a thermometer, and a temperature control device, as a hydrogenated polybutadiene polyol compound, KRASOL HLBH-P 2000 (iodine value: 13.5, hydroxyl value: 0.89 meq / g) manufactured by CRAY VALEY 511.69 g (0.23 mol), 7.19 g (0.0023 mol) of Exenol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg · KOH / g) manufactured by Asahi Glass Co., Ltd. as a diol compound, and a new polymerizable compound 197.08 g of S-1800A (isostearyl acrylate) manufactured by Nakamura Chemical Co., Ltd. and 0.36 g of 4-methoxyphenol as a polymerization inhibitor were added and stirred until uniform, and the internal temperature was adjusted to 50 ° C. Subsequently, 61.35 g (0.28 mol) of isophorone diisocyanate was added as a polyisocyanate compound and reacted at 80 ° C. until the target NCO content was reached. Next, 11.00 g (0.095 mol) of 2-hydroxyethyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd. is used as the (meth) acrylate compound having at least one hydroxyl group, and 0 octylate is used as the urethanization reaction catalyst. .20 g was added and reacted at 80 ° C., and the point where the NCO content became 0.1% or less was set as the end point of the reaction to obtain a polyurethane compound (E-3).

Example 1
20 parts by mass of the polyurethane compound (E-1) of Synthesis Example 1, 22 parts by mass of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., 10 parts by mass of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, Yashara Chemical Co., Ltd. Clearon M-105 (aromatically modified hydrogenated terpene resin) 18 parts by mass, JX Nippon Oil & Energy Corporation LV-100 (polybutene) 10 parts by mass, Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 20 parts by mass, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 0.5 parts by mass, BASF IRGACURE184 (1-hydroxycyclohexylphenyl) Ketone) 0.5 parts by mass, PBD (2- (4-Bifeni) manufactured by Wako Pure Chemical Industries, Ltd. Lu) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (0.05 parts by mass) was heated to 70 ° C. and mixed to obtain a resin composition of the present invention. The viscosity of the composition was 3200 mPa · s.

Example 2
20 parts by mass of the polyurethane compound (E-2) of Synthesis Example 2, 22 parts by mass of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., 10 parts by mass of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, Yashara Chemical Co., Ltd. Clearon M-105 (aromatically modified hydrogenated terpene resin) 18 parts by mass, JX Nippon Oil & Energy Corporation LV-100 (polybutene) 10 parts by mass, Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 20 parts by mass, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 0.5 parts by mass, BASF IRGACURE184 (1-hydroxycyclohexylphenyl) Ketone) 0.5 parts by mass, PBD (2- (4-Bifeni) manufactured by Wako Pure Chemical Industries, Ltd. Lu) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (0.05 parts by mass) was heated to 70 ° C. and mixed to obtain a resin composition of the present invention. The viscosity of the composition was 5000 mPa · s.

Example 3
20 parts by mass of the polyurethane compound (E-3) of Synthesis Example 3, 22 parts by mass of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., 10 parts by mass of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, Yashara Chemical Co., Ltd. Clearon M-105 (aromatically modified hydrogenated terpene resin) 18 parts by mass, JX Nippon Oil & Energy Corporation LV-100 (polybutene) 10 parts by mass, Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 20 parts by mass, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 0.5 parts by mass, BASF IRGACURE184 (1-hydroxycyclohexylphenyl) Ketone) 0.5 parts by mass, PBD (2- (4-Bifeni) manufactured by Wako Pure Chemical Industries, Ltd. Lu) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (0.05 parts by mass) was heated to 70 ° C. and mixed to obtain a resin composition of the present invention. The viscosity of the composition was 5500 mPa · s.

  Examples 1 to 3 are shown in Table 1 and evaluated as follows.

(viscosity)
It measured at 25 degreeC using the E-type viscosity meter (TV-200: Toki Sangyo Co., Ltd. product).

(Refractive index)
The refractive index (25 ° C.) of the resin was measured with an Abbe refractometer (DR-M2: manufactured by Atago Co., Ltd.).

(Curing shrinkage)
Prepare two glass slides with a thickness of 1 mm coated with a fluorine-based release agent, and apply the resulting UV-curable adhesive composition to one of the release agent application surfaces so that the film thickness is 200 μm. did. Thereafter, the two slide glasses were bonded so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light quantity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two slide glasses were peeled off to produce a cured product for measuring the film specific gravity. Based on JIS K7112 B method, specific gravity (DS) of hardened | cured material was measured. Moreover, the liquid specific gravity (DL) of the resin composition was measured at 25 degreeC. From the measurement results of DS and DL, the cure shrinkage rate was calculated from the following formula and found to be less than 2.5%.
Curing shrinkage (%) = (DS−DL) ÷ DS × 100

(Rigidity)
Two release-treated PET films were prepared, and the obtained ultraviolet curable adhesive composition was applied to one of the release surfaces so that the film thickness was 200 μm. Thereafter, the two PET films were bonded together such that the release surfaces face each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light quantity of 3000 mJ / cm ^{2 through} a PET film with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two PET films were peeled off to prepare a cured product for measuring the rigidity. The rigidity was measured with ARES (manufactured by TA Instruments).

(Transmittance)
Two slide glasses having a thickness of 1 mm were prepared, and the obtained ultraviolet curable adhesive composition was applied to one of them so that the film thickness after curing was 200 μm. Then, two slide glasses were bonded together. The resin composition was cured by irradiating ultraviolet rays with an integrated light amount of 3000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, ozone-less) through the glass to prepare a cured product for measuring transmittance. About the transparency of the obtained hardened | cured material, the transmittance | permeability in the wavelength range of 400-800 nm and 400-450 nm was measured using the spectrophotometer (U-3310, Hitachi High-Technologies Corporation). As a result, the transmittance of 400 to 800 nm was 90% or more, and the transmittance of 400 to 450 nm was 90% or more.

(Heat and moisture resistant adhesion)
A 1 mm thick glass slide and a 1 mm thick glass plate, or a 1 mm thick glass plate with a polarizing film pasted on one side are prepared, and the obtained UV curable adhesive composition has a film thickness of 200 μm. Then, the other was bonded to the coated surface. Through the glass, the resin composition was irradiated with ultraviolet rays having an integrated light amount of 3000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, ozone-less), and the resin composition was cured to prepare a sample for evaluating adhesiveness. Using this, a heat resistance test at 85 ° C. and a humidity resistance test at 60 ° C. and 90% RH were conducted and left for 100 hours. In the sample for evaluation, peeling of the cured resin from the glass or polarizing film was confirmed visually, but there was no peeling.

Example 4
20 parts by mass of the polyurethane compound (E-1) of Synthesis Example 1, 19 parts by mass of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., 10 parts by mass of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, Yashara Chemical Co., Ltd. Clearon M-105 (aromatically modified hydrogenated terpene resin) 18 parts by mass, JX Nippon Oil & Energy Corporation LV-100 (polybutene) 10 parts by mass, Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 20 parts by mass, Osaka Organic Chemical Industries, Ltd. 4-HBA (4-hydroxybutyl acrylate) 3 parts by mass, LAMBSON speed cure TPO (2,4,6-trimethyl) 0.5 parts by mass of benzoyldiphenylphosphine oxide) IRGACURE184 (1-hydroxycyclo) manufactured by BASF Hexylphenylketone) 0.5 parts by mass was heated to 70 ° C. and mixed to obtain a resin composition of the present invention.

Example 5
20 parts by mass of the polyurethane compound (E-2) of Synthesis Example 2, 19 parts by mass of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., 10 parts by mass of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, Yashara Chemical Co., Ltd. Clearon M-105 (aromatically modified hydrogenated terpene resin) 18 parts by mass, JX Nippon Oil & Energy Corporation LV-100 (polybutene) 10 parts by mass, Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 20 parts by mass, Osaka Organic Chemical Industries, Ltd. 4-HBA (4-hydroxybutyl acrylate) 3 parts by mass, LAMBSON speed cure TPO (2,4,6-trimethyl) 0.5 parts by mass of benzoyldiphenylphosphine oxide) IRGACURE184 (1-hydroxycyclo) manufactured by BASF Hexylphenylketone) 0.5 parts by mass was heated to 70 ° C. and mixed to obtain a resin composition of the present invention.

Example 6
20 parts by mass of the polyurethane compound (E-3) of Synthesis Example 3, 19 parts by mass of S-1800A (isostearyl acrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., 10 parts by mass of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, 18 parts by mass of Clearon M-105 (aromatically modified hydrogenated terpene resin) manufactured by Yashara Chemicals Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nippon Oil & Energy Corporation, T-5562 manufactured by Asahi Kasei Chemicals Corporation (Polycarbonate polyol) 20 parts by mass, Osaka Organic Chemical Co., Ltd. 4-HBA (4-hydroxybutyl acrylate) 3 parts by mass, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 0.5 parts by mass, IRSFACURE184 (1-hydroxycyclohexyl) manufactured by BASF Ruphenylketone) 0.5 parts by mass was heated to 70 ° C. and mixed to obtain a resin composition of the present invention.

  Examples 4 to 6 are shown in Table 2 and evaluated as follows.

(Viscosity) It was measured at 25 ° C. using an E-type viscometer (TV-200: manufactured by Toki Sangyo Co., Ltd.).

(Refractive index)
The refractive index (25 ° C.) of the resin was measured with an Abbe refractometer (DR-M2: manufactured by Atago Co., Ltd.).

(Curing shrinkage)
Two glass slides having a thickness of 1 mm coated with a fluorine-based release agent were prepared, and the obtained ultraviolet curable resin composition was applied to one of the release agent application surfaces so that the film thickness was 200 μm. . Thereafter, the two slide glasses were bonded so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light quantity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two slide glasses were peeled off to produce a cured product for measuring the film specific gravity. Based on JIS K7112 B method, specific gravity (DS) of hardened | cured material was measured. Moreover, the liquid specific gravity (DL) of the resin composition was measured at 25 degreeC. From the measurement results of DS and DL, the cure shrinkage rate was calculated from the following formula.
Curing shrinkage (%) = (DS−DL) ÷ DS × 100

(Rigidity)
Two release-treated PET films were prepared, and the obtained ultraviolet curable resin composition was applied to one of the release surfaces so that the film thickness was 200 μm. Thereafter, the two PET films were bonded together such that the release surfaces face each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light quantity of 3000 mJ / cm ^{2 through} a PET film with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two PET films were peeled off to prepare a cured product for measuring the rigidity. The rigidity was measured with ARES (manufactured by TA Instruments).

(Transmittance)
Two slide glasses having a thickness of 1 mm were prepared, and the obtained ultraviolet curable resin composition was applied to one of them so that the film thickness after curing was 200 μm. Then, two slide glasses were bonded together. The resin composition was cured by irradiating ultraviolet rays with an integrated light amount of 3000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, ozone-less) through the glass to prepare a cured product for measuring transmittance. About the transparency of the obtained hardened | cured material, the transmittance | permeability in the wavelength range of 400-800 nm and 400-450 nm was measured using the spectrophotometer (U-3310, Hitachi High-Technologies Corporation). As a result, the transmittance of 400 to 800 nm was 90% or more, and the transmittance of 400 to 450 nm was 90% or more.

(Heat and moisture resistant adhesion)
Prepare a slide glass with a thickness of 1 mm and a glass plate with a thickness of 1 mm, or a glass plate with a thickness of 1 mm with a polarizing film pasted on one side, and the obtained UV curable resin composition has a film thickness of 200 μm. Then, the other was bonded to the coated surface. Through the glass, the resin composition was irradiated with ultraviolet rays having an integrated light amount of 3000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, ozone-less), and the resin composition was cured to prepare a sample for evaluating adhesiveness. Using this, a heat resistance test at 85 ° C. and a humidity resistance test at 60 ° C. and 90% RH were conducted and left for 100 hours. In the sample for evaluation, peeling of the cured resin from the glass or polarizing film was confirmed visually, but there was no peeling.

  The following evaluation was performed using the obtained resin compositions of Examples 1 to 6 of the present invention.

(Whitening resistance)
Two slide glasses having a thickness of 1 mm were prepared, applied to one slide glass so that the film thickness of Examples 4 to 6 was 200 μm, and the other slide glass was bonded to the application surface. Thereafter, the composition was irradiated with ultraviolet rays having a cumulative light amount of 4000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, with an ozone-less / IR cut filter). The obtained test piece was placed in an environment of 80 ° C. and 85% RH for 48 hours, and then the state of the film 15 minutes after removal into the 25 ° C. and 45% RH environment, and the state of the cured film 3 hours after removal. It was confirmed visually.
It apply | coated so that the film thickness of Examples 4-6 might be set to 200 micrometers on the slide glass of thickness 1mm, and peeling PET film was bonded together on the application surface. Thereafter, the composition was irradiated with ultraviolet rays having an integrated light amount of 4000 mJ / cm ^{2 through} a peeled PET film with a high-pressure mercury lamp (80 W / cm, with ozone-less / IR cut filter). The obtained joined body was put in an environment of 80 ° C. and 85% RH for 48 hours, and then the state of the film 15 minutes after being taken out in the environment of 25 ° C. and 45% RH, and the state of the cured film 3 hours after being taken out. It was confirmed visually. As a result of evaluation, the compositions of Examples 4 to 6 were all “good”.
◯: No whitening of the film Δ: Whitening after 15 minutes but no whitening after 3 hours ×: Whitening after 15 minutes and also whitening after 3 hours

(Curing speed)
Two slide glasses having a thickness of 1 mm were prepared and applied such that the film thicknesses of Examples 1 to 6 were 200 μm, and the other slide glass was bonded to the application surface. Thereafter, the composition was irradiated with ultraviolet rays with an integrated light amount of 100 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, with ozone-less / IR cut filter). Thereafter, the slide glass was peeled off, and the state of the composition was confirmed. The evaluation results were all good.
○: No fluidity ×: Insufficient curing and fluidity

(Adhesive strength)
A glass joined body was obtained according to the following experimental example.
(Experimental Example 1) Two glass plates having a size of width 2 cm × length 3.5 cm × thickness 1 mm were prepared, and the compositions of Examples 1 to 6 were 250 μm in thickness and 6 mm in diameter at the center of one of the glass plates. It was applied to make a circle. Thereafter, an electrodeless ultraviolet lamp (D-bulb manufactured by Heraeus Noblelight Fusion Ubuy Co., Ltd.) is used for the obtained coating layer, and the accumulated light quantity is 100 mJ from the atmosphere through an ultraviolet cut filter that blocks a wavelength of 320 nm or less. / Cm ² of ultraviolet rays was irradiated to form a cured product layer having a cured portion present on the lower side (glass plate side) of the coating layer and an uncured portion present on the upper side (atmosphere side) of the coating layer. In addition, the ratio of the maximum illuminance in the range of 200 to 320 nm was 3 when the maximum illuminance in the range of 320 to 450 nm was 100 for the ultraviolet rays irradiated to Examples 1 to 6 at this time. Further, the uncured portion existing on the upper side (atmosphere side) of the coating layer and the other glass plate are bonded in a cross shape (direction intersecting 90 °), and the accumulated light amount is 2000 mJ / day through the bonded glass. The cured resin layer was cured by irradiating cm ² ultraviolet rays to obtain a joined body.
(Experimental example 2) Two glass plates having a size of width 2 cm × length 3.5 cm × thickness 1 mm were prepared, and the compositions of Examples 1 to 6 were dropped into the center of one of the glass plates, and the diameter was 6 mm. It adjusted so that it might become a thickness of 250 micrometers in a circle. Thereafter, the dropped glass and the other glass plate are bonded together in a cross shape (in a direction crossing 90 °), and the cured resin layer is formed by irradiating the bonded glass with ultraviolet light having an accumulated light amount of 2000 mJ / cm ^2. Was cured to obtain a joined body.

One glass plate of the joined body obtained above was fixed, and the other glass plate was peeled off vertically upward to confirm the adhesive strength. The adhesive strength was as shown in Table 3 below.

  From the above results, the ultraviolet curable resin composition and the production method of the present invention have good curability, high whitening resistance, strong adhesion to the base material, and are directly applied to the base material to be bonded. Then, it can be seen that it has a high adhesive force even when it is cured by irradiating ultraviolet rays and the other substrate is bonded. It was also confirmed that there was an effect of increasing the adhesive strength by forming irregularities on the surface.

  Furthermore, the following evaluation was performed using Examples 1-6 of the obtained this invention.

(Curing shrinkage)
Two slide glasses having a thickness of 1 mm coated with a fluorine-based release agent were prepared, and the composition was applied to one of the release agent application surfaces so that the film thickness was 200 μm. That word, two slide glasses were bonded together so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an accumulated light amount of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two slide glasses were peeled off to produce a cured product for measuring the film specific gravity. Based on JIS K7112 B method, specific gravity (DS) of hardened | cured material was measured. Moreover, the liquid specific gravity (DL) of the resin composition was measured at 25 degreeC. From the measurement results of DS and DL, the cure shrinkage percentage was calculated from the following formula and was less than 3.0%.
Curing shrinkage (%) = (DS−DL) ÷ DS × 100

(Heat and moisture resistant adhesion)
A slide glass with a thickness of 0.8 mm and an acrylic plate with a thickness of 0.8 mm were prepared, and after applying the composition obtained on one side so that the film thickness was 200 μm, the other was bonded to the application surface. . Through the glass, the resin composition was irradiated with ultraviolet rays having an integrated light quantity of 2000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, ozone-less), and the resin composition was cured to prepare a sample for evaluating adhesiveness. This was left to stand at 85 ° C. and 85% RH for 250 hours. In the sample for evaluation, peeling of the slide glass or the acrylic plate from the cured resin was visually confirmed, but there was no peeling.

(Flexibility)
The obtained composition was fully cured, and the durometer E hardness was measured using a durometer hardness meter (type E) by a method based on JIS K7215 to evaluate the flexibility. More specifically, the ultraviolet curable resin composition was poured into a cylindrical mold so that the film thickness was 1 cm, and the resin composition was sufficiently cured by irradiation with ultraviolet rays. The hardness of the obtained cured product was measured with a durometer hardness meter (type E). As a result, the measured value was less than 10, and the flexibility was excellent.

(transparency)
Prepare two glass slides with a thickness of 1 mm coated with a fluorine-based mold release agent, and apply the resulting composition to one of the mold release agent coating surfaces so that the film thickness after curing is 200 μm. did. Thereafter, the two slide glasses were bonded so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating ultraviolet rays with an integrated light quantity of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two slide glasses were peeled off to produce a cured product for measuring transparency. About the transparency of the obtained hardened | cured material, the transmittance | permeability in the wavelength range of 400-800 nm and 400-450 nm was measured using the spectrophotometer (U-3310, Hitachi High-Technologies Corporation). As a result, the transmittance of 400 to 800 nm was 90% or more, and the transmittance of 400 to 450 nm was 90% or more.

(Curability of the resin under the shading part)
The composition is applied to each substrate on the display surface of the liquid crystal display unit having an area of 3.5 inches and the surface on which the light-shielding portion on the transparent substrate having the light-shielding portion (width 5 mm) is formed on the outer periphery. It applied so that it might become. Next, an electrodeless ultraviolet lamp (D bulb, manufactured by Heraeus Noblelight Fusion Ubuy Co., Ltd.) was used for the obtained coating layer, and the accumulated light quantity from the atmosphere side was 100 mJ / A cured product layer having a cured portion and an uncured portion existing on the atmosphere side was formed by performing ultraviolet irradiation of cm ² . In this case, the ratio of the maximum illuminance in the range of 200 to 320 nm was 3 when the maximum illuminance in the range of 320 to 450 nm was 100.
Thereafter, a liquid crystal display unit and a transparent substrate having a light-shielding portion were bonded together with the uncured portions facing each other. Finally, the resin cured product layer is cured by irradiating UV light with an integrated light amount of 2000 mJ / cm ² from the glass substrate side having the light shielding portion with an ultra-high pressure mercury lamp (TOSCURE752, manufactured by Harrison Toshiba Lighting Co., Ltd.). Produced. The transparent substrate was removed from the obtained optical member, and the cured resin layer of the light shielding part was washed away with heptane, and then the cured state was confirmed. There was no evidence that the uncured resin composition was removed, and the resin in the light shielding portion was sufficiently cured.

(Measurement method of surface irregularities)
The resin composition was applied to glass having a thickness of 1 mm so that the film thickness was 250 μm. Thereafter, an electrodeless ultraviolet lamp (D-bulb manufactured by Heraeus Noblelight Fusion Ubuy Co., Ltd.) is used for the obtained coating layer, and the accumulated light quantity is 100 mJ from the atmosphere through an ultraviolet cut filter that blocks a wavelength of 320 nm or less. After irradiating with UV light of / cm ² and allowing to stand for 10 minutes, the surface condition was confirmed using a laser displacement meter LK series manufactured by Keyence Corporation. Unevenness was confirmed in all samples.

Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
In addition, the present application includes a Japanese patent application (2014-120621) filed on June 11, 2014, a Japanese patent application (2015-114861) filed on June 5, 2015, and June 5, 2015. Based on the Japanese patent application (2015-115105) filed on date and the Japanese patent application (2015-116938) filed on June 9, 2015, the entirety of which is incorporated by reference. Also, all references cited herein are incorporated as a whole.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display unit, 2 Transparent substrate which has light-shielding part, 3 Transparent substrate, 4 Light-shielding part, 5 Ultraviolet curable resin composition (ultraviolet curable resin composition), 6 Hardened | cured material layer which has an uncured part, 7 Resin hardening Material layer, 8 UV

Claims (18)

  A resin composition characterized in that the resin layer applied on a flat surface forms irregularities having an outermost surface of the resin layer of 1 μm or more when irradiated with ultraviolet rays.   A resin composition containing a rubber component (a) and a non-rubber component (b) and used to bond at least two optical substrates, and having a fatty chain having 8 to 30 carbon atoms (meth) The ultraviolet curable resin composition for a touch panel according to claim 1, comprising an acrylate (A), a softening component (B), a photopolymerizable oligomer (C), and a photopolymerization initiator (E). A monofunctional (meth) acrylate (A) having a fatty chain having 8 to 30 carbon atoms is represented by the following formula (10):

(In the above formula, R represents H or CH ₃ , and R ₂ represents an alkyl group having 10 to 20 carbon atoms.)
The ultraviolet curable resin composition for a touch panel according to claim 2, wherein the monofunctional (meth) acrylate (A) having a fatty chain having 8 to 30 carbon atoms represented by the formula (10) is: The ultraviolet curable resin composition for touchscreens which is 35 weight% or less in a resin composition.   The photopolymerizable oligomer (C) is selected from the group consisting of urethane (meth) acrylate, polyisoprene or (meth) acrylate having a hydrogenated polyisoprene skeleton, polybutadiene or (meth) acrylate having a hydrogenated polybutadiene skeleton One or more types are contained, The ultraviolet curable resin composition for touchscreens of Claim 2 or 3 characterized by the above-mentioned.   The photopolymerizable oligomer (C) is a urethane (meth) acrylate having at least one skeleton selected from the group consisting of polypropylene / polybutadiene / hydrogenated polybutadiene / polyisoprene / hydrogenated polyisoprene. The ultraviolet curable resin composition for touchscreens of Claim 4. Furthermore, it contains a photopolymerizable monomer (D) other than the component (A), and the component (D) is represented by the following formula (1):

(In the formula, R ₁ represents a hydrogen atom or CH ₃ , and n represents an integer of 1 to 3)
It is represented by these. The ultraviolet curable resin composition for touchscreens as described in any one of Claims 2-5 characterized by the above-mentioned.   The said Formula (1) is 4-hydroxybutyl acrylate, The ultraviolet curable resin composition for touchscreens of Claim 6 characterized by the above-mentioned.   The ultraviolet curable resin for touch panel according to any one of claims 2 to 7, wherein the softening component (B) includes one or both of a hydroxyl group-containing polymer and a liquid terpene resin. Resin composition.   The ultraviolet curable resin for touch panels as described in any one of Claims 2-8 containing 1-30 weight% of monofunctional (meth) acrylate (A) which has a C10-C30 fatty chain which has a branched chain. Composition.   Furthermore, the photopolymerizable monomer (D) other than (A) component is contained, and this (D) component contains the photopolymerizable monomer which does not have a hydroxyl group, The ultraviolet-ray for touchscreens as described in any one of Claims 2-8 A curable resin composition.   The monofunctional (meth) acrylate (A) having a fatty chain having 8 to 30 carbon atoms contains isostearyl acrylate, and the ultraviolet curable type for touch panel according to any one of claims 1 to 10, Resin composition. The manufacturing method of the optical member by which the at least 2 optical base material which has the following processes 1-2 was pasted.
(Step 1) The ultraviolet curable resin composition for a touch panel according to any one of claims 1 to 11 is applied to at least one optical substrate to form an application layer, and the application layer is applied to the application layer. Step of obtaining an optical substrate having a cured product layer by irradiating with ultraviolet rays (Step 2) The other optical substrate is bonded to the cured product layer of the optical substrate obtained in Step 1, or The process of bonding the hardened | cured material layer of the other optical base material obtained by the process 1   13. The production according to claim 12, wherein the cured product layer obtained in Step 1 has a cured portion present on the optical substrate side and an uncured portion present on the opposite side to the optical substrate side. Method. The manufacturing method according to claim 13, further comprising the following step 3 after the steps 1 and 2.
(Step 3) A step of irradiating the cured product layer having an uncured portion in the bonded optical substrate with ultraviolet rays to cure the cured product layer.   The maximum illuminance in the range of 200 to 320 nm is 30 or less when the maximum illuminance in the range of 320 nm to 450 nm is 100, which is the ultraviolet ray irradiated to the ultraviolet curable resin composition in the step 1. The manufacturing method of the optical member as described in any one of Claims 12-14.   The maximum illuminance in the range of 200 to 320 nm is 10 or less when the maximum illuminance in the range of 320 nm to 450 nm is 100 as the ultraviolet ray irradiated to the ultraviolet curable resin composition in the step 1. The manufacturing method of the optical member as described in any one of Claims 12-14.   Hardened | cured material obtained by irradiating an active energy ray to the ultraviolet curable resin composition as described in any one of Claims 1-11.   A touch panel comprising the ultraviolet curable resin composition according to any one of claims 1 to 11.

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