JP6778106B2 - Ultraviolet curable resin composition for touch panels, bonding method and articles using it - Google Patents

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, a display device capable of screen input by attaching a touch panel to the display screen of a display device such as a liquid crystal display, a plasma display, or an organic EL display has been widely used. In this touch panel, a glass plate or a resin film on which a transparent electrode is formed is bonded to face each other with a slight gap, and 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 of using a double-sided adhesive sheet for bonding a glass plate or film on which a transparent electrode is formed on a touch panel and a transparent protective plate made of glass or resin, or for bonding a touch panel and a display unit. However, there is a problem that air bubbles easily enter when the double-sided adhesive sheet is used. As an alternative technique to the double-sided adhesive sheet, a technique of bonding with a flexible ultraviolet curable resin composition has been proposed.

On the other hand, it is known that various photopolymerizable monomers are used as an ultraviolet curable resin composition for a touch panel used in a technique of adhering a touch panel and a display unit with an ultraviolet curable adhesive. For example, Patent Document 1 proposes the use of isobornyl acrylate, dicyclopentenyloxyethyl methacrylate, 2-hydroxybutyl methacrylate and the like. However, these photopolymerizable monomers are highly volatile, and under vacuum during the touch panel manufacturing process, the component ratio is changed due to the volatilization of these compounds over time during use, resulting in a constant value. There was a problem that the physical properties were not guaranteed.

On the other hand, Patent Document 2 describes that lauryl (meth) acrylate is used as the long-chain (meth) acrylate in the ultraviolet curable resin composition for a touch panel. However, long-chain (meth) acrylates that do not have such branched chains do not exhibit sufficient compatibility when used in combination with photopolymerizable oligomers and softening components, and are insoluble after being left for a long time. There is a risk that the components may precipitate, and it is also difficult to reduce the viscosity of the resin composition.

Japanese Patent No. 5470735 Japanese Patent No. 55363983

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain an optical member such as a display unit having good productivity, low volatility, low dielectric constant, good curability and adhesion, and a touch panel having excellent workability and storage stability. It is an object of the present invention to provide an ultraviolet curable resin composition for use.

The present inventors have completed the present invention as a result of diligent research to solve the above problems. That is, the present invention relates to the following (1) to (17).
(1) A resin composition used for bonding at least two optical substrates, which is a monofunctional (meth) acrylate (A) having a branched chain and a fat chain having 10 to 30 carbon atoms, and a softening component (a softening component). An ultraviolet curable resin composition for a touch panel, which comprises B), a photopolymerizable oligomer (C), and a photopolymerization initiator (E).
(2) The monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having a branched chain 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 (1).
(3) 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. The ultraviolet curable resin composition for a touch panel according to (1) or (2), which contains any one or more of them.
(4) 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 a touch panel according to (3).
(5) Further contains a photopolymerizable monomer (D) other than the component (A), and the component (D) is 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 (1) to (4), which is represented by.
(6) The ultraviolet curable resin composition for a touch panel according to (5), wherein the formula (1) is 4-hydroxybutyl acrylate.
(7) The item according to any one of (1) to (6), wherein the softening component (B) contains either one or both of a hydroxyl group-containing polymer and a liquid terpene resin. UV curable resin composition for touch panels.
(8) The touch panel according to any one of (1) to (7), which contains 1 to 30% by weight of a monofunctional (meth) acrylate (A) having a branched chain and having a fat chain having 10 to 30 carbon atoms. UV curable resin composition for.
(9) In any one of (1) to (7), which further contains a photopolymerizable monomer (D) other than the component (A), and the component (D) contains a photopolymerizable monomer having no hydroxyl group. The ultraviolet curable resin composition for a touch panel described.
(10) The item according to any one of (1) to (9), which contains isostearyl acrylate as the monofunctional (meth) acrylate (A) having a branched chain and having 10 to 30 carbon atoms. UV curable resin composition for touch panels.
(11) A method for manufacturing an optical member having at least two optical substrates attached to each other, which have the following steps 1 and 2.
(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 a coating layer, and the coating is applied. Step of obtaining an optical base material having a cured product layer by irradiating the layer with ultraviolet rays (step 2) Another optical base material is attached to the cured product layer of the optical base material obtained in step 1. Alternatively, a step of laminating the cured product layer of another optical substrate obtained in step 1 (12) The cured product layer obtained in step 1 is present on the optical substrate side and the cured portion on the optical substrate side. The production method according to (11), which has an uncured portion existing on the opposite side of the optics.
(13) The production method according to (12), further comprising the following step 3 after the steps 1 and 2.
(Step 3) A step of irradiating a cured product layer having an uncured portion in the bonded optical base material with ultraviolet rays to cure the cured product layer.
(14) 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 30 or less for the ultraviolet rays irradiated to the ultraviolet curable resin composition in the step 1. The method for manufacturing an optical member according to any one of (12) to (13).
(15) 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 for the ultraviolet rays irradiated to the ultraviolet curable resin composition in the step 1. The method for manufacturing an optical member according to any one of (12) to (13).
(16) A cured product obtained by irradiating the ultraviolet curable resin composition according to any one of (1) to (10) with active energy rays.
(17) A touch panel characterized by using the ultraviolet curable resin composition according to any one of (1) to (10).

It is a process drawing which shows 1st Embodiment of the manufacturing method of this invention. It is a process drawing which shows the 2nd Embodiment of the manufacturing method of this invention. It is a process drawing which shows the 3rd Embodiment of the manufacturing method of this invention. It is a process drawing which shows the 4th Embodiment of the manufacturing method of this invention. It is the schematic of the optical member obtained by this invention.

First, the ultraviolet curable resin composition of the present invention will be described. In addition, "can be added to the ultraviolet curable resin composition used for optics" means that the additive that reduces the transparency of the cured product to the extent that it cannot be used for optics is not included. In addition, in this specification, "(meth) acrylate" means either one or both of metal acrylate and acrylate. The same applies to "(meth) acrylic acid" and the like. Further, "acrylate" represents only acrylate, and metal acrylate is excluded.
When a cured product sheet having a thickness of 200 μm after curing is prepared from the ultraviolet curable resin composition used in the present invention, the preferable average transmittance of the sheet with light having a wavelength of 400 to 800 nm is determined. At least 90%.

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 a monofunctional (meth) having a branched chain and a fat chain having 10 to 30 carbon atoms. ) It is characterized by containing an acrylate (A). The number of carbon atoms is more preferably 16 to 25.
Specific examples of the (meth) acrylate that can be used as the monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having a branched chain include isolauryl (meth) acrylate and isostearyl (meth) acrylate. , Isocetyl (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 Kyoei Co., Ltd., and the like.
As described above, by using the (meth) acrylate having a long-chain fat chain having a branched chain, it functions as a mediator for enhancing the compatibility with the softening component (B) or the polymerizable oligomer (C). It is possible to effectively prevent insoluble components from precipitating even after being left for a long time. In addition, it is possible to obtain a resin composition having a low dielectric constant while ensuring flexibility.

The monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having a branched chain contained in the ultraviolet curable resin composition for a touch panel of the present invention has the following formula (10).

(In the above formula, R represents H or CH ₃ , R ₂ represents an alkyl group having 10 to 20 carbon atoms, and n represents an integer of 10 to 25.)
It is preferable to use a monofunctional (meth) acrylate represented by. Here, the carbon number of R ₂ is more preferably 15 to 20.
By using the monofunctional (meth) acrylate of the above formula (10), flexibility and reactivity can be improved. Further, among them, isostearyl (meth) acrylate is more preferable from the viewpoint of low volatility, reactivity, and flexibility.
Further, two or more kinds of monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having the branched chain may be mixed and used.

The ultraviolet curable resin composition for a touch panel of the present invention includes a monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having a branched chain and a (linear) carbon having no branched chain. It is preferable to use a monofunctional (meth) acrylate (F) having a fat chain of several 8 to 30 in combination. The following formula (11) can be used as the monofunctional (meth) acrylate (F) having a linear fat chain having 8 to 30 carbon atoms.

(In the above formula, R represents H or CH ₃ , R ₃ represents an alkyl group having 8 to 20 carbon atoms, and n represents an integer of 10 to 25.)
It is preferable to use a monofunctional (meth) acrylate represented by. Here, the carbon number of R ₃ is more preferably 15 to 20.
By using the monofunctional (meth) acrylate of the above formula (11), flexibility and reactivity can be improved. Further, among them, lauryl (meth) acrylate is more preferable from the viewpoint of low volatility, reactivity, and flexibility.

Here, from the viewpoint of improving compatibility while avoiding white turbidity of the resin composition itself and ensuring transparency, the alkyl groups of R ₂ to R ₃ of the above formula (10) and / or the above formula (11) In the compound represented by the formula (1) described later, it is preferable to show a constant ratio 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 preferable that the resin composition contains 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 the above-mentioned low volatilization and whitening-resistant acrylate and both compounds having the above-mentioned special ratio of 5.5 or less. It is preferable, and it is particularly preferable that it is 5 or less.

The content of the component (A) in the composition is usually about 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. Within this range, the compatibility with the softening component (B) and the photopolymerizable oligomer (C), which will be described later, is improved, and while giving flexibility, the function of suppressing the improvement of the dielectric constant is achieved. This is because the precipitation / precipitation of the insoluble component can be effectively prevented, and the polarity of the resin composition can be suppressed from becoming too low.

It is preferable to use the component (A) and the component (F) in combination, and in this case, the content of the component (A) is preferably equal to or higher than the content of the component (F). The weight ratio of the component (A): component (F) in the resin composition is preferably 9.9: 0.1 to 0.1: 9.9, preferably 9: 1 to 3: 7. More preferably, 9: 1 to 5: 5 is more preferable, and 9: 1 to 6: 4 is particularly preferable.

In the present invention, it is preferable to use a photopolymerizable monomer having no hydroxyl group as the photopolymerizable monomer (D) described later in combination with the component (A). As described above, by using the photopolymerizable monomer having no hydroxyl group in combination, it is possible to suppress the polarity from being excessively increased and to suppress the polarity to a certain degree. Further, this is because it becomes easy to obtain a resin composition that does not easily contain water. As such a photopolymerizable monomer having no hydroxyl group, one obtained by removing the photopolymerizable monomer having a hydroxyl group from the photopolymerizable monomer (D) described later can be used.

The ultraviolet curable resin composition for a touch panel of the present invention contains a softening component (B). The softening component (B) is not crosslinked by ultraviolet rays, but is present between the crosslinks of the photopolymerizable oligomer or the photopolymerizable monomer, thereby imparting flexibility and reducing the shrinkage rate. Have. It also has a function of improving adhesion by imparting stickiness.
Examples of such a softening component (B) include polymers, oligomers, phthalates, phosphate esters, glycol esters, citrate esters, aliphatic dibasic acid esters, and the like, which are compatible with the composition. Examples thereof include fatty acid esters, epoxy plasticizers, castor oils, terpene resins, hydrogenated terpene resins, and liquid terpenes. Examples of the above-mentioned oligomers and polymers include polyisoprene skeletons, hydrogenated polyisoprene skeletons, polybutadiene skeletons, hydrogenated polybutadiene skeletons or oligomers or polymers having a xylene skeleton and esterified products thereof, adipic acid ester-based oligomers, polybutene and the like. be able to. From the viewpoint of transparency, hydrogenated terpene resin, hydrogenated polyisoprene, hydrogenated polybutadiene, polybutene, and liquid terpene are preferable. Further, from the viewpoint of adhesive strength and compatibility with other materials, a hydrogenated terpene resin containing a hydroxyl group at the end or side chain, a hydrogenated polymer containing a hydroxyl group at the end or side chain, and a hydroxyl group at the end. Alternatively, a hydroxyl group-containing polymer such as hydrogenated polybutadiene or a liquid terpene resin contained in the side chain is particularly preferable.

As for the weight ratio of the softening component in the ultraviolet curable resin composition, the softening component (B) can be used in either solid or liquid form, and the softening component is usually 5 to 70% by weight, preferably 10 to 10% by weight. It is 60% by weight. The softening component of the solid is usually 5 to 40% by weight, preferably 10 to 35% by 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 contains a photopolymerizable oligomer (C). The photopolymerizable oligomer (C) in the ultraviolet curable resin composition of the present invention is not particularly limited, but is urethane (meth) acrylate, polyisoprene or hydrogenated (meth) acrylate having a polyisoprene skeleton, polybutadiene or hydrogenated. It is preferable to use any 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 further, from the viewpoint of moisture resistance, it has at least one skeleton selected from the group consisting of polybutadiene / hydrogenated polybutadiene / polyisoprene / hydrogenated polyisoprene. 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, 1,6-hexanediol, triols such as trimethylolpropane and pentaerythritol, tricyclodecanedimethylol and bis- [hydroxymethyl] -cyclohexane Alcohols, etc .; and polyester polyols obtained by the reaction of these polyhydric alcohols with polybasic acids (eg, succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride, etc.) , Caprolactone alcohol obtained by reaction of polyhydric alcohol with ε-caprolactone, polycarbonate polyol (for example, polycarbonate diol obtained by reaction of 1,6-hexanediol and diphenyl carbonate) or polyether polyol (for example, polyethylene glycol, polypropylene). Glycol, polytetramethylene glycol, ethylene oxide-modified bisphenol A, 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 has a weight average molecular weight from the viewpoint of transparency and flexibility. Propylene glycol having a value of 2000 or more, hydrogenated polybutadiene glycol, and hydrogenated polyisoprene glycol are particularly preferable. Hydrogenated polybutadiene glycol is preferable from the viewpoint 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 5,000 or less. In addition, two or more kinds of polyhydric alcohols may be used in combination 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. Of these, isophorone diisocyanate is preferable from the viewpoint of toughness.

Examples of the hydroxyl group-containing (meth) acrylate include hydroxyC2-C4 alkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate, and dimethylolcyclohexylmono (dimethylolcyclohexylmono). Hydroxycaprolactone (meth) acrylate, hydroxyl group-terminated polyalkylene glycol (meth) acrylate and the like can be used.

The reaction for obtaining the urethane (meth) acrylate is carried out, for example, as follows. That is, the polyhydric alcohol is mixed with an organic polyisocyanate per 1 equivalent of the hydroxyl group so that the isocyanate group is preferably 1.1 to 2.0 equivalents, more preferably 1.1 to 1.5 equivalents, 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 1 equivalent of the isocyanate group of the urethane oligomer, and reacted at 70 to 90 ° C. to obtain the desired urethane (meth). ) Acrylate can be obtained.

The weight average molecular weight of the urethane (meth) acrylate is preferably about 7,000 to 100,000, more preferably 1,000 to 60,000. If the weight average molecular weight is less than 7,000, the shrinkage becomes large, and if the weight average molecular weight is more than 100,000, the curability becomes poor.

In the ultraviolet curable resin composition of the present invention, one type or two or more types of urethane (meth) acrylate can be used in an arbitrary ratio. The weight ratio of the 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. (Meta) acrylates having a polyisoprene skeleton can be obtained as UC-203, UC102, UC-1 (manufactured by Kuraray). The (meth) acrylate having a polyisoprene skeleton preferably has a polystyrene-equivalent number average molecular weight of 1,000 to 50,000, and more preferably about 2,500 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 urethane (meth) acrylate, polyisoprene or (meth) acrylate having a hydrogenated polyisoprene skeleton, polybutadiene or (meth) acrylate having a hydrogenated polybutadiene skeleton (meth). Meta) Indicates acrylate.

The photopolymerizable monomer (D) contained in the ultraviolet curable resin composition of the present invention includes 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 is preferably used.
The composition ratio of the ultraviolet curable resin composition is preferably 1 to 20% by weight of the monofunctional acrylate represented by the above formula (1), 5 to 90% by weight of the photopolymerizable oligomer (C), and the formula. The photopolymerizable monomer (D) other than (1) is 5 to 90% by weight, the photopolymerization initiator (E) is 0.1 to 5% by weight, and other components are the balance.

Examples of the monofunctional acrylate (A) represented by the formula (1) in the ultraviolet curable resin composition of the present invention include 4-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, and 2-hydroxyethyl. Examples thereof include acrylate, and two or more of them may be used in combination if necessary. Here, in the above formula (1), when n is 2 or less (particularly when n is 1 or less), it is preferable that R ₁ is a methyl group. Further, when n is 3 or more, R ₁ is preferably a hydrogen atom. Further, in the above formula (1), a resin composition having a total carbon number of 2 or more is preferable because a resin composition having less volatility and less cloudiness can be obtained. Above all, from the viewpoint of adhesive strength and whitening resistance, the following formula (2)

(In the formula, n indicates an integer of 2 to 4)
The monofunctional acrylate represented by is preferable. Examples of the monofunctional acrylate represented by the formula (2) include 4-hydroxybutyl acrylate, 3-hydroxypropyl acrylate, and 2-hydroxyethyl acrylate. Further, 4-hydroxybutyl acrylate is particularly preferable from the viewpoint of low volatility. It is not preferable to use a metal acrylate-based resin because the curing rate tends to be slow and it takes time to cure when the resin composition is actually used.
Here, in the compound represented by the above formula (1), when the total number of carbon atoms excluding the acryloyl group is MC and the number of OH groups is MOH, and the number of branched chains of carbon is MB, MOH. / (MC + MB) is preferably 0.3 or less, particularly preferably 0.28 or less, and particularly preferably 0.25 or less. Within such a range, it is possible to suppress volatilization and white turbidity because the molecular weight becomes a certain degree, and it is possible to realize that it works advantageously to prevent whitening due to hydroxyl groups. The monofunctional acrylate represented by the formula (1) satisfying the above conditions is hereinafter referred to as a low volatilization / 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 further preferably 5.5 to 8% by weight. If the content of the component of formula (1) is less than 1%, the whitening resistance is lowered. On the other hand, if it is 20% by weight or more, air 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 to contain a methacrylate having a hydroxyl group in the ultraviolet curable resin composition because it adversely affects physical properties such as a decrease in the curing rate and whitening resistance. When a methacrylate having a hydroxyl group is contained, 10% by weight or less is preferable, and 5% by weight or less is particularly preferable.

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. Twenty-five alkyl (meth) acrylates, benzyl (meth) acrylates, tetrahydrofurfuryl (meth) acrylates, acryloylmorpholin, phenylglycidyl (meth) acrylates, tricyclodecane (meth) acrylates, dicyclopentenyl acrylates, dicyclopentenyloxyethyl (Meta) 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, dicyclopentadieneoxyethyl (meth) acrylate, etc. (meth) acrylate having a cyclic skeleton, alkyl (meth) acrylate having a hydroxyl group and having 5 to 7 carbon atoms, ethoxydiethylene glycol (meth) acrylate , Polyalkylene glycol (meth) acrylates, polypropylene oxide-modified nonylphenyl (meth) acrylates and other polyalkylene glycol (meth) acrylates, ethylene oxide-modified phenoxylated phosphate (meth) acrylates, ethylene oxide-modified butoxylated phosphate (meth) acrylates and ethylene oxide. Examples thereof include modified octyloxylated phosphoric acid (meth) acrylate and caprolactone-modified tetrafurfuryl (meth) acrylate.

The composition of the present invention may contain (a (meth) acrylate other than the (meth) acrylate having one (meth) acryloyl group in the molecule) as long as the characteristics of the present invention are not impaired. For example, trimethylolpropane 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. , Caprolactone-modified hydroxypivalate neopentyl glycol di (meth) acrylate and ethylene oxide-modified di (meth) acrylate phosphate, trimethylolpropane tri (meth) acrylate, trimethylol octantri (meth) acrylate and other trimethylol C2-C10 alkanes Trimethylol C2-C10 alkamppolyalkoxys such as trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, trimethylolpropane polyethoxypolypropoxytri (meth) acrylate Tri (meth) acrylate, Tris [(meth) acroyloxyethyl] isocyanurate, pentaerythritol tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) Alkylene oxide-modified trimethylolpropane tri (meth) acrylate such as acrylate Pentaerythritol polyethoxytetra (meth) acrylate, pentaerythritol polypropoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dimethylolpropane tetra (meth) acrylate , Dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like can be mentioned.
In the present invention, when used in combination, it is preferable to use a mono- or bifunctional (meth) acrylate in order to suppress curing shrinkage.

In the ultraviolet curable resin composition of the present invention, one kind or two or more kinds of these (meth) acrylate monomer components can be used in an arbitrary ratio. The weight ratio of the photopolymerizable monomer (D) other than the above 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. If it is less than 5% by weight, the curability becomes poor, and if it is more than 90% by weight, the shrinkage becomes large.

Further, in the present invention, the ratio (weight ratio) of the component of the above formula (1) to the component of the above 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 in the ultraviolet curable resin composition of the present invention as long as the characteristics of the present invention are not impaired. Epoxy (meth) acrylate has a function of improving curability, hardness of cured product, and curing speed. Further, as the epoxy (meth) acrylate, any one obtained by reacting a glycidyl ether type epoxy compound with (meth) acrylic acid can be used, but an epoxy (meth) acrylate which is preferably used is used. 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, and diglycidyl of hydrogenated bisphenol A or its alkylene oxide adduct. Diglycidyl ether of ether, hydrogenated bisphenol F or its alkylene oxide adduct, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, cyclohexane Examples thereof include dimethanol diglycidyl ether and polypropylene glycol diglycidyl ether.

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

The (meth) acrylic acid is reacted at a ratio of 0.9 to 1.5 mol, more preferably 0.95 to 1.1 mol, based on 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, tetraethylammonium chloride and the like. Further, for example, paramethoxyphenol, methylhydroquinone and the like can be used as a polymerization inhibitor in order to prevent polymerization during the reaction.

The 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 10000.
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 is, for example, 2,4,6-trimethylbenzoyldiphenylphosphenyl oxide, 2,4,6-trimethylbenzoylphenylethoxyphos. Finoxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphenyloxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphinoxide, 1-hydroxycyclohexylphenylketone ( Irgacure 184; manufactured by BASF, 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer (Esacure ONE; manufactured by Lamberti), 1- [4- (2-hydroxyethoxy) -phenyl ] -2-Hydroxy-2-methyl-1-propane-1-one (Irgacure 2959; manufactured by BASF), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl)- Benzyl] -Phenyl} -2-Methyl-Propane-1-one (Irgacure 127; manufactured by BASF), 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651; manufactured by BASF), 2-Hydroxy-2-methyl -1-Phenyl-Propane-1-one (Darocure 1173; manufactured by BASF), 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (Irgacure 907; manufactured by BASF), A mixture of oxy-phenyl-acetylic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetylid 2- [2-hydroxy-ethoxy] -ethyl ester (Irgacure) 754; manufactured by BASF), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-one, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, isopropyl Thioxanthone 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 having a value of / (g · cm) or less. By using such a photopolymerization initiator, it is possible to contribute to the improvement of the adhesive strength. When the molar extinction coefficient at 302 nm or 313 nm is 300 ml / (g · cm) or more, the curing at the time of curing in the following step 3 is sufficient. On the other hand, when the molar absorption coefficient at 365 nm is 100 ml / (g · cm) or less, excessive curing can be appropriately suppressed during curing in the following step 1, and adhesion can be improved.
Examples of such a photopolymerization initiator (E) include 1-hydroxycyclohexylphenyl ketone (Irgacure 184; manufactured by BASF) and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocure 1173). (Made by BASF), 1- [4- (2-Hydroxyethoxy) -phenyl-] -2-hydroxy-2-methyl-1-propane-1-one (Irgacure 2959; manufactured by BASF), Phenylglycylic acid Methyl ester (Darocure MBF; manufactured by BASF) and the like can be mentioned.

In the ultraviolet curable resin composition of the present invention, these photopolymerization initiators (E) can be used alone or in admixture of two or more at any ratio. 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. If it is more than 5% by weight, when a cured product layer having a cured portion and an uncured portion existing on the opposite side of the optical base material side is obtained, the uncured portion cannot be formed or the transparency of the resin cured product layer becomes poor. It may get worse.

The ultraviolet curable resin composition of the present invention may contain additives and the like described later as other components.

Further, amines and the like which can be a photopolymerization initiator can be used in combination with the above-mentioned photopolymerization initiator. Examples of amines that can be used include benzoic acid 2-dimethylaminoethyl ester, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester and the like. When a photopolymerization initiator such as amines is used, 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.

The ultraviolet curable resin composition of the present invention contains, if necessary, an antioxidant, an organic solvent, a silane coupling agent, a polymerization inhibitor, a leveling agent, an antistatic agent, a surface lubricant, an optical brightener, and a light stabilizer. Additives such as agents (eg, hindered amine compounds), fillers and the like may be added.

Specific examples of the antioxidant include 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-t-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 sulfoxide, dimethyl sulfoxide, tetrahydrofuran, dioxane, toluene, xylene and the like.

Specific examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 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-Chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane and other silane coupling agents; isopropyl (N-ethylaminoethylamino) titanate, isopropyltriisostearoyl titanate, titanium di (dioctylpyrophosphate) oxy Titanium-based coupling agents such as acetate, tetraisopropyldi (dioctylphosphite) titanate, neoalkoxytri (p-N- (β-aminoethyl) aminophenyl) titanate; Zr-acetylacetonate, Zr-methacrylate, Zr- Propionate, neoalkoxyzirconate, neoalkoxytris neodecanoyl zirconate, neoalkoxytris (dodecanoyl) benzenesulfonyl zirconate, neoalkoxytris (ethylenediaminoethyl) zirconate, neoalkoxytris (m-aminophenyl) zirconate, ammonium zirconium Examples thereof include zirconium such as carbonate, Al-acetylacetonate, Al-methacrylate and Al-propionate, and aluminum-based coupling agents.

Specific examples of the polymerization inhibitor include paramethoxyphenol, methylhydroquinone and the like.

Specific examples of the light stabilizer include 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 Adeca Co., Ltd., LA-82), Tetrax (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3 With 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] Mixed esterified product with undecane, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1-undecanoxy-2,2,6,6-tetramethylpiperidine-4-) Il) 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-tetramethylpiperidine, 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-hydroxy Phenyl] methyl] butylmalonate, bisdecanoate (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, reaction product of 1,1-dimethylethylhydroperoxide and octane , N, N', N ", N"'-Tetrax- (4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidine-4-yl) amino) -triazine -2-yl) -4,7-diazadecan-1,10-diamine, dibutylamine, 1,3,5-triadidine, N, N'-bis (2,2,6) , 6-Tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate, poly [[6- (1,1, 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-piperidinethanol, 2,2,4 , 4-Tetramethyl-20- (β-lauryloxycarbonyl) ethyl-7-oxa-3,20-diazadispiro [5.1.11.2] Heneikosan-21-one, β-alanine, N,-(2) , 2,6,6-Tetramethyl-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] heneikosan-21-one, 2,2,4,5-tetra Methyl-21-oxa-3,20-diazazicyclo- [5,1,11,2] -Heneicosan-20-propanoic acid dodecyl ester / tetradecyl ester, propandioic acid, [(4-methoxyphenyl) -methylene] -Bis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester, higher fatty acid ester of 2,2,6,6-tetramethyl-4-piperidinol, 1,3-benzenedicarboxyamide, N , N'-bis (2,2,6,6-tetramethyl-4-piperidinyl) and other hindered amine compounds, octabenzone and other benzophenone compounds, 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-tetrahydrophthalimide) -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-benzotriazole) A reaction product of -2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol, benzo such as 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol. Triazole compounds, benzoate compounds such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (4,6-diphenyl-1,3,5-triazine) Examples thereof include triazine compounds such as -2-yl) -5-[(hexyl) oxy] phenol, and hindered amine compounds are particularly preferable.

Specific examples of the filler include 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 and beads obtained by spheroidizing them.

When present in the compositions of the 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. It is 0.02 to 0.5% by weight.

The ultraviolet curable resin composition of the present invention can be obtained by mixing and dissolving each of the above-mentioned components at room temperature to 80 ° C., and if necessary, impurities may be removed by an operation such as filtration. In consideration of coatability, the adhesive resin composition of the present invention preferably has a compounding ratio of components appropriately adjusted so that the viscosity at 25 ° C. is in the range of 300 to 40,000 mPa · s.

Next, a preferable form of the manufacturing process of the optical member using the ultraviolet curable resin composition of the present invention will be described.
In the method for manufacturing 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 (step 2), (step 3) can be omitted.
(Step 1) The ultraviolet curable resin composition is applied to at least one optical base material to form a coating layer, and the coating layer is irradiated with ultraviolet rays to form an optical group in the coating layer. The cured portion (hereinafter referred to as "cured portion of the cured product layer" or simply "cured portion") existing on the material side (lower side of the coating layer) and the side opposite to the optical base material side (upper side of the coating layer). A step of obtaining an optical base material having a cured product layer having an uncured portion (hereinafter, referred to as "uncured portion of the cured product layer" or simply "uncured portion") existing on the atmospheric side). In step 1, the curing rate of the coated layer after irradiation with ultraviolet rays is not particularly limited, and an uncured portion exists on the surface opposite to the optical substrate side (upper side of the coated layer, usually on the atmospheric side). All you have to do is. After irradiating with ultraviolet rays, if the side opposite to the optical base material side (upper side of the coating layer, usually the atmospheric side) is touched with a finger and a liquid component adheres to the finger, it can be determined that the uncured portion is present.
(Step 2) Another optical base material is attached to the uncured portion of the cured product layer of the optical base material obtained in step 1, or the other optical base material obtained in step 1 is cured. The process of laminating the uncured parts of the material layer.
(Step 3) A step of irradiating a cured product layer having an uncured portion in a bonded optical base material with ultraviolet rays through an optical base material having a light-shielding portion to cure the cured product layer.
Hereinafter, specific embodiments of the method for manufacturing an optical member of the present invention via steps 1 to 3 will be described 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 to at least one substrate in a liquid resin state, and to the other substrate in a liquid state. When it is bonded with a resin state or a state having an uncured part and then cured by ultraviolet rays, it has a particularly excellent adhesive effect and can prevent the intervention of air, so it is particularly recommended to use it in such a case. preferable.

(First Embodiment)
FIG. 1 is a process diagram showing a first embodiment of a manufacturing 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 laminating the liquid crystal display unit 1 and the transparent substrate 2.
The liquid crystal display unit 1 is a unit in which a liquid crystal material is sealed between a pair of substrates on which electrodes are formed, and is provided with a polarizing plate, a driving circuit, a signal input cable, and a backlight unit.
The transparent substrate 2 is a transparent substrate such as a glass plate, a polymethylmethacrylate (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 a hard coat treatment or an antireflection treatment on one or both sides.
Here, as the transparent substrate 2, a 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 attaching a tape, applying a paint, printing, or the like. In the present invention, the present invention can be applied to those having no light-shielding portion 4, but in the following description of the first to third embodiments, the case where the light-shielding portion 4 is provided will be described as a specific example. When the light-shielding portion 4 is not provided, the "transparent substrate having the light-shielding portion" can be read as "transparent substrate", and it can be considered as an example of the case where the light-shielding portion is not provided as it is.

(Step 1)
First, as shown in FIG. 1A, the ultraviolet curable resin composition is applied to the surface of the display surface of the liquid crystal display unit 1 and the surface of the transparent substrate 2 having the light-shielding portion where the light-shielding portion is formed. Examples of the coating method include a slit coater, a roll coater, a spin coater, a screen printing method and the like. Here, the ultraviolet curable resin composition applied to the surfaces 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, the film thickness of the cured product layer of the ultraviolet curable resin existing on the surface of the transparent substrate 2 having a light-shielding portion depends on the film thickness, but is usually ultraviolet curable existing on the surface of the liquid crystal display unit 1. It is preferable that the film thickness is about the same as or thicker than the film thickness of the cured product layer of the mold resin. This is to minimize the portion remaining uncured even after irradiation with ultraviolet rays in the step 3 described later, thereby eliminating the risk of curing failure.

The UV-curable resin composition layer 5 after coating is irradiated with UV light 8, and a cured portion existing on the lower side of the coating layer (the liquid crystal display unit side or the transparent substrate side when viewed from the UV-curable resin composition) (in the figure). Curing with uncured parts (not shown in the figure) that exist on the upper side of the coating layer (opposite to the liquid crystal display unit side or the side opposite to the transparent substrate side) (atmosphere side when performed in the atmosphere) Obtain the material layer 6. The irradiation amount is preferably 5 to 2000 mJ / cm ² , and particularly preferably 10 to 1000 mJ / cm ² . If the irradiation amount is too small, the degree of curing of the resin of the finally bonded optical member may be insufficient, and if the irradiation amount is too large, the uncured component is reduced, and the liquid crystal display unit 1 and the light-shielding portion are separated. There is a risk that the transparent substrate 2 to be held will be poorly bonded.
In the present invention, "uncured" means a state of fluidity in an environment of 25 ° C. If the resin composition layer is touched with a finger after irradiation with ultraviolet rays and a liquid component adheres to the finger, it is determined that the resin composition layer has an uncured portion.
For curing by irradiating ultraviolet to near-ultraviolet rays, any light source may be used as long as the lamp irradiates ultraviolet to near-ultraviolet rays. For example, low pressure, high pressure or ultra high pressure mercury lamps, metal halide lamps, (pulse) xenon lamps, electrodeless lamps and the like can be mentioned.
In step 1 of the present invention, the wavelength of the ultraviolet rays 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 in 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 the maximum illuminance (illuminance ratio) in the range of 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior. This is because when the illuminance at a low wavelength is high, the UV-curable resin composition is excessively cured during curing in step 1, and the contribution to adhesion during curing in UV irradiation in step 3 is reduced. It is thought that this is because it ends up.
Here, as a method of irradiating ultraviolet rays so as to have the above illuminance ratio, for example, as a lamp for irradiating ultraviolet to near-ultraviolet rays, a method of applying a lamp satisfying the illuminance ratio, or the lamp itself has the illuminance. Even when the above conditions are 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 during irradiation in step 1. It is possible to irradiate at a ratio. The base material for adjusting the illuminance ratio of ultraviolet rays is not particularly limited, and examples thereof include a glass plate subjected to a short-wave ultraviolet ray cut treatment, soda-lime glass, and a PET film. It should be noted that a damping plate or the like in which the surface of quartz glass or the like is subjected to unevenness treatment is not very effective. Since these materials scatter light and reduce the illuminance, they are not suitable for selectively reducing the illuminance of short wavelengths of 320 nm or less.
In step 1, the irradiation of ultraviolet rays is usually performed in the air on the upper surface on the coating side (the side opposite to the liquid crystal display unit side or the side opposite to the transparent substrate side when viewed from the ultraviolet curable resin composition) (normal atmospheric surface). ) Is preferable. Further, after creating a vacuum, irradiation with ultraviolet rays may be performed while spraying a curing inhibitory gas on the upper surface of the coating layer. When the resin composition is cured in the air, the side opposite to the liquid crystal display unit side or the side opposite to the transparent substrate side is the atmosphere side. If 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 an environment of a gas such as nitrogen that does not cause curing inhibition.
On the other hand, when step 3 is omitted, it is preferable to perform curing in vacuum or while spraying a gas (for example, nitrogen) that promotes curing. As a result, even if step 3 is omitted, sufficient adhesion can be performed.

By spraying oxygen or ozone on the surface of the ultraviolet curable resin layer (coating layer) at the time of ultraviolet irradiation, the state of the uncured portion and the film thickness of the uncured portion can be adjusted.
That is, by spraying oxygen or ozone 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 can be secured. The film thickness can be increased.

(Step 2)
Next, as shown in FIG. 1B, the liquid crystal display unit 1 and the transparent substrate 2 having the light-shielding portion are bonded together so that the uncured portions face each other. The bonding can be performed in the air or in a vacuum.
Here, in order to prevent bubbles from being generated during bonding, it is preferable to bond in vacuum.
As described above, when a cured product of the 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 and then bonded, an improvement in adhesive strength can be expected.
The bonding can be performed by pressurization, pressing, or the like.

(Step 3)
Next, as shown in FIG. 1C, 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, and is ultraviolet-curable. 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 rays may be any light source as long as it is a lamp that irradiates ultraviolet to near-ultraviolet rays. For example, low pressure, high pressure or ultra high pressure mercury lamps, metal halide lamps, (pulse) xenon lamps, electrodeless lamps and the like can be mentioned.
In this way, the 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 following modified second embodiment. Since the details of each step are the same as those of the first embodiment described above, the same parts will not be described.

(Step 1)
First, as shown in FIG. 2A, the ultraviolet curable composition is applied to the surface of the transparent substrate 2 having the light-shielding portion on which the light-shielding portion 4 is formed, and then the obtained coating layer (ultraviolet-curable type) is applied. By irradiating the resin composition layer 5) with ultraviolet rays 8, the cured portion existing on the lower side of the coating layer (the transparent substrate side when viewed from the ultraviolet curable resin composition) and the upper side of the coating layer (opposite to the transparent substrate side). A cured product layer 6 having an uncured portion existing on 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 rays 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 in the range of 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 in the range of 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior.

(Step 2)
Next, as shown in FIG. 2B, the transparent substrate 2 having the liquid crystal display unit 1 and the light-shielding portion is formed so that 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 them together. The bonding can be performed in the air or in a vacuum.

(Step 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 to cure the ultraviolet rays. 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 manufacturing an optical member using the ultraviolet curable resin composition of the present invention. Since the details of each step are the same as those of the first embodiment described above, the same parts will not be described.
The same members as the constituent members in the above-described first embodiment are designated by the same reference numerals in the drawings, and the description thereof will not be repeated here.

(Step 1)
First, as shown in FIG. 3A, the ultraviolet curable composition was applied to the surface of the liquid crystal display unit 1. After that, the ultraviolet curable resin composition layer 5 is irradiated with ultraviolet rays 8, and the cured portion existing on the lower side 8 of the coating layer 8 (the transparent substrate side when viewed from the ultraviolet curable resin composition) and the upper side (the upper side of the coating layer) ( A cured product layer 6 having an uncured portion existing on the side opposite to the transparent substrate side is obtained.
At this time, the wavelength of the ultraviolet rays 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 in the range of 200 to 320 nm is preferably 30 or less, particularly. 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, and the maximum illuminance in the range of 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member is inferior.

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

(Step 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 to cure the ultraviolet rays. 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. Since the details of each step are the same as those of the first embodiment described above, the same parts will not be described. Although the fourth embodiment has been described based on the second embodiment in which the step 3 is omitted, the omission can also be performed in the first to third embodiments described above.

(Step 1)
First, as shown in FIG. 4A, the ultraviolet curable composition is applied to the surface of the transparent substrate 2 having the light-shielding portion on which the light-shielding portion 4 is formed, and then the obtained coating layer (ultraviolet-curable type) is applied. By irradiating the resin composition layer 5) with ultraviolet rays 8, the cured portion existing on the lower side of the coating layer (the transparent substrate side when viewed from the ultraviolet curable resin composition) and the upper side of the coating layer (opposite to the transparent substrate side). A cured product layer 6 having an uncured portion existing on 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 rays 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 in the range of 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 in the range of 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior.

(Step 2)
Next, as shown in FIG. 4B, the transparent substrate 2 having the liquid crystal display unit 1 and the light-shielding portion is formed so that 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 them together. The bonding can be performed in the air or in a vacuum.

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

Each of the above embodiments describes some of the embodiments of the method for manufacturing an optical member of the present invention with one specific optical base material. In each embodiment, a liquid crystal display unit and a transparent substrate having a light-shielding portion have been described, but in the manufacturing method of the present invention, various members described later can be used as an optical substrate instead of the liquid crystal display unit. As the transparent substrate, various members described later can be used as the optical substrate.
Not only that, as an optical base material such as a liquid crystal display unit and a transparent substrate, a film bonded to these various members with another optical base material layer (for example, a cured product layer of an ultraviolet curable resin composition). Alternatively, another optical substrate layer laminated) may be used.
Further, the method for applying the ultraviolet curable resin composition, the film thickness of the cured resin, the irradiation amount and the light source at the time of ultraviolet irradiation, and oxygen on the surface of the ultraviolet curable resin layer described in the section of the first embodiment. Alternatively, the 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 of the production methods included in the present invention.

Specific embodiments of the optical members that can be manufactured in the first to third embodiments, including the liquid crystal display unit, are shown below.
(I) At least one optical substrate having a light-shielding portion selected from the group consisting of a transparent glass substrate having a light-shielding portion, a transparent resin substrate having a light-shielding portion, and a glass substrate having a light-shielding portion and a transparent electrode formed therein. It is an optical base material, and the optical base material to be bonded to the optical base material 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, and the obtained optical member provides the light-shielding portion. A mode in which the display unit has an optical substrate.
(Ii) One optical base material is a protective base material having a light-shielding portion, and the other optical base material to be bonded to the protective base material is a touch panel or a display unit having a touch panel, and at least two optical base materials are bonded together. An embodiment 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 one of the surface provided with the light-shielding portion of the protective base material having the light-shielding portion, the touch surface of the touch panel, or both. It is preferable to apply.
(Iii) One optical base material is an optical base material having a light-shielding portion, the other optical base material to be bonded to the optical base material is a display unit, and an optical member to which at least two optical base materials are bonded is An embodiment of a display unit having an optical base material having a light-shielding portion.
In this case, in the step 1, the ultraviolet curable resin is applied to either one or both of the surface of the optical base material having the light-shielding portion provided with the light-shielding portion and the display surface of the display unit. It is preferable to apply the composition.
Specific examples of the optical base material having a light-shielding portion include a protective plate for a display screen having a light-shielding portion, a touch panel provided with a protective base material having a light-shielding portion, and the like.
The surface of the optical base material having a light-shielding portion on the side where the light-shielding portion is provided means, for example, when the optical base material having the light-shielding portion is a protective plate for a display screen having a light-shielding portion, the light-shielding portion of the protective plate is shielded. This is the side surface on which the portion is provided. Further, when the optical base material having a light-shielding portion is a touch panel having a protective base material having a light-shielding portion, the surface of the protective base material having the light-shielding portion is bonded to the touch surface of the touch panel. The surface of the optical base material having the light-shielding portion on the side where the light-shielding portion is provided means the base material surface of the touch panel opposite to the touch surface of the touch panel.
The light-shielding portion of the optical base material having the light-shielding portion may be located at any position of the optical base material, but is usually formed in a frame shape around the transparent plate-shaped or sheet-shaped optical base material, and its width is wide. , 0.5 mm to 10 mm, preferably about 1 to 8 mm, and more preferably about 2 to 8 mm.

The ultraviolet curable resin composition of the present invention manufactures an optical member by adhering at least two optical substrates by the above (step 1) to (step 2) and, if necessary, (step 3). Can be used for the method of
The curing shrinkage rate 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. This makes it possible to reduce the internal stress accumulated in the cured resin composition when the ultraviolet curable resin composition is cured, and at the interface between the base material and the layer made of the cured product of the ultraviolet curable resin composition. It is possible to effectively prevent the formation of distortion.
Further, when the base material such as glass is thin, when the curing shrinkage rate is large, the warp at the time of curing becomes large, which has a great adverse effect on the display performance. Therefore, the curing shrinkage rate is also small from this viewpoint. Is preferable.

The transmittance of the cured product of the ultraviolet curable resin composition of the present invention at 400 nm to 800 nm is preferably 90% or more. This is because when the transmittance is less than 90%, it is difficult for light to pass through and the visibility is lowered when used in a display device.
Further, if the transmittance of the cured product at 400 to 450 nm is high, the visibility can be further improved. Therefore, 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 manufacturing an optical member by laminating a plurality of optical substrates by the above (steps 1) to (step 3).
Examples of the optical base material used in the method for manufacturing 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 base material" means both an optical base material having no light-shielding portion on the surface and an optical base material having a light-shielding portion on the surface. In the method for manufacturing an optical member of the present invention, at least one of a plurality of optical base materials preferably used is an optical base material having a light-shielding portion.
The position of the light-shielding portion on the optical substrate having the light-shielding portion is not particularly limited. In 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 around the peripheral portion of the optical substrate. In some cases. The light-shielding portion on the optical substrate can be formed by attaching a tape, applying a paint, printing, or the like.

Various materials can be used as the material of the optical base material used in the present invention. Specific examples thereof include PET, PC, PMMA, a composite of PC and PMMA, and resins such as glass, COC, COP, and plastic (acrylic resin, etc.). The optical base material used in the present invention, for example, a transparent plate or sheet, is a sheet or transparent plate in which a plurality of films or sheets such as a polarizing plate are laminated, a non-laminated sheet or transparent plate, and a transparent material made of inorganic glass. Plates (inorganic glass plates and processed products thereof, such as lenses, prisms, ITO glass) and the like can be used.
The optical base material used in the present invention is a laminate composed of a plurality of functional plates or sheets such as a touch panel (touch panel input sensor) or the following display unit in addition to the above-mentioned polarizing plate (hereinafter, "functional laminate"). Also called "body").

Examples of the sheet that can be used as the optical base material 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 manufacturing the optical member of the present invention include a decorative plate and a protective plate. As the material of these sheets or plates, those listed as the materials of transparent plates can be applied.
Examples of the touch panel surface material 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 the plate-shaped or sheet-shaped optical base material 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, and more preferably about 50 μm to 3 mm. 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 a cured product of the ultraviolet curable resin composition of the present invention. Examples of the optical members bonded together in.
Further, in the manufacturing method of the present invention, a display unit such as a liquid crystal display device is used as one of the optical base materials, and an optical functional material is used as another optical base material. Hereinafter, it is also referred to as a display panel). Examples of the display unit include display devices such as LCDs, EL displays, EL illuminations, electronic papers, and plasma displays in which a polarizing plate is attached to glass. Further, examples of the optical functional material include an acrylic plate, a PC plate, a PET plate, a transparent plastic plate such as a PEN plate, tempered glass, and a touch panel input sensor.

When used as an adhesive for bonding optical substrates, when the refractive index of the cured product is 1.45 to 1.55 for improving visibility, the visibility of the displayed image is further improved, which is preferable.
Within the range of the refractive index, the difference in the refractive index from the base material used as the optical base material can be reduced, and diffused reflection of light can be suppressed to reduce the light loss.

Preferred embodiments of the optical member obtained by the production method of the present invention include the following (i) to (vii).
(I) An optical member in which an optical base material having a light-shielding portion and the functional laminate are bonded together using a cured product of the ultraviolet curable resin composition of the present invention.
(Ii) An optical base selected from the group consisting of a transparent glass substrate having a light-shielding portion, a transparent resin substrate having a light-shielding portion, and a glass substrate on which a light-shielding object and a transparent electrode are formed. The optical member according to (i) above, which is a material and the functional laminate is a display unit or a touch panel.
(Iii) The optical member according to (ii) above, 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 base material having a light-shielding portion is bonded to the surface of the touch panel on the touch surface side using a cured product of the ultraviolet curable resin composition of the present invention. ).
(V) A display panel in which a plate-shaped or sheet-shaped optical base material having a light-shielding portion is bonded to a display screen of a display unit using a 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 base material having a light-shielding portion is a protective base material or a touch panel for protecting the display screen of the display body unit.
(Vi) In any one of (i) to (vi) above, the ultraviolet curable resin composition is the ultraviolet curable resin composition according to any one of (1) to (10) above. The optical member, touch panel or display panel described.

By using the ultraviolet curable resin composition of the present invention and laminating a plurality of optical substrates selected from the above optical substrates by the methods described in (Step 1) to (Step 3) above, the present invention 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 facing surfaces of the two optical substrates to be bonded via the cured product layer, or may be applied to both surfaces. good.
For example, in the case of the optical member according to (ii) above, wherein the functional laminate is a touch panel or a display unit, in step 1, one surface of the protective base material having a light-shielding portion, preferably the light-shielding portion, is used. 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.
Further, in the case of the optical member (vi) described above in which a protective base material or a touch panel for protecting the display screen of the display body unit is attached to the display body unit, a light-shielding portion of the protective base material is provided in step 1. The resin composition may be applied to only one of the surface or the base material surface opposite to the touch surface of the touch panel and the display surface of the display unit, or may be applied to both of them.

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

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Synthesis example 1
GI-2000 (iodine value: 12.2, hydroxyl value: 46.8 mg, KOH) manufactured by Nippon Soda Co., Ltd. as a hydrogenated polybutadiene polyol compound in a reactor equipped with a reflux cooler, a stirrer, a thermometer, and a temperature controller. / G) is 569.73 g (0.24 mol), and as a diol compound, Excelol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg, KOH / g) manufactured by Asahi Glass Co., Ltd. is 7.50 g (0.0024 mol), polymerizable. Add 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 and stir until uniform, and set the internal temperature to 50 ° C. did. Subsequently, 80.03 g (0.36 mol) of isophorone diisocyanate was added as a polyisocyanate compound, and the reaction was carried out 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. was used as the (meth) acrylate compound having at least one hydroxyl group, and 0 tin octylate was used as the urethanization reaction catalyst. .20 g was added and reacted at 80 ° C., and the end point of the reaction was when the NCO content was 0.1% or less to obtain a polyurethane compound (E-1).

Synthesis example 2
GI-2000 (iodine value: 12.2, hydroxyl value: 46.8 mg, KOH) manufactured by Nippon Soda Co., Ltd. as a hydrogenated polybutadiene polyol compound in a reactor equipped with a reflux cooler, a stirrer, a thermometer, and a temperature controller. / G) is 545.99 g (0.23 mol), Asahi Glass Co., Ltd. Excelol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg, KOH / g) is 7.19 g (0.0023 mol) as a diol compound, and is polymerizable. Add 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 and stir until uniform, and set the internal temperature to 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. as a (meth) acrylate compound having at least one hydroxyl group, and 0 tin octylate as a urethanization reaction catalyst. .20 g was added and reacted at 80 ° C., and the end point of the reaction was when the NCO content was 0.1% or less to obtain a polyurethane compound (E-2).

Synthesis example 3
KRASOL HLBH-P 2000 (iodine value: 13.5, hydroxyl value: 0.89 meq / g) manufactured by CRAY VALLEY as a hydrogenated polybutadiene polyol compound in a reactor equipped with a reflux cooler, a stirrer, a thermometer, and a temperature controller. 511.69 g (0.23 mol), 7.19 g (0.0023 mol) of Excelol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg · KOH / g) manufactured by Asahi Glass Co., Ltd. as a diol compound, new as a 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. as a (meth) acrylate compound having at least one hydroxyl group, and 0 tin octylate as a urethanization reaction catalyst. .20 g was added and reacted at 80 ° C., and a polyurethane compound (E-3) was obtained when the NCO content was 0.1% or less as the end point of the reaction.

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 Blemmer LA (lauryl acrylate) manufactured by Nichiyu Co., Ltd., 18 parts by mass of Clearon M-105 (aromatically modified hydrogenated terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nikko Nisseki Energy Co., Ltd., GI-2000 manufactured by Nippon Soda Co., Ltd. (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) 0.5 parts by mass of ketone), 0.05 parts by mass of PBD (2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole manufactured by Wako Pure Chemical Industries, Ltd. Was heated to 70 ° C. and mixed to obtain the resin composition of the present invention. The viscosity of this resin 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 Blemmer LA (lauryl acrylate) manufactured by Nichiyu Co., Ltd., 18 parts by mass of Clearon M-105 (aromatically modified hydrogenated terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nikko Nisseki Energy Co., Ltd., GI-2000 manufactured by Nippon Soda Co., Ltd. (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) 0.5 parts by mass of ketone), 0.05 parts by mass of PBD (2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole manufactured by Wako Pure Chemical Industries, Ltd. Was heated to 70 ° C. and mixed to obtain the resin composition of the present invention. The viscosity of this resin 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 Blemmer LA (lauryl acrylate) manufactured by Nichiyu Co., Ltd., 18 parts by mass of Clearon M-105 (aromatically modified hydrogenated terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nikko Nisseki Energy Co., Ltd., GI-2000 manufactured by Nippon Soda Co., Ltd. (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) 0.5 parts by mass of ketone), 0.05 parts by mass of PBD (2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole manufactured by Wako Pure Chemical Industries, Ltd. Was heated to 70 ° C. and mixed to obtain the resin composition of the present invention. The viscosity of this resin composition was 5500 mPa · s.

Examples 1 to 3 are shown in Table 1, and the following evaluations were performed.

(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 refractive index meter (DR-M2: manufactured by Atago Co., Ltd.).

(Curing shrinkage rate)
Two 1 mm thick slide glasses coated with a fluorine-based mold release agent were prepared, and the obtained UV-curable adhesive composition was applied to one of the slide glass coated with the mold release agent so that the film thickness was 200 μm. did. After that, two slide glasses were attached so that the release agent-coated surfaces faced each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light intensity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless). Then, the two slide glasses were peeled off to prepare a cured product for measuring the specific gravity of the film. The specific gravity (DS) of the cured product was measured according to the JIS K7112 B method. Further, the liquid specific gravity (DL) of the resin composition was measured at 25 ° C. When the curing shrinkage rate was calculated from the measurement results of DS and DL from the following formula, it was less than 2.5%.
Curing shrinkage rate (%) = (DS-DL) ÷ DS × 100

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

(Transmittance)
Two slide glasses having a thickness of 1 mm were prepared, and one of them was coated with the obtained ultraviolet curable adhesive composition so that the film thickness after curing was 200 μm. After that, two slide glasses were pasted together. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light intensity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless) to prepare a cured product for transmittance measurement. Regarding the transparency of the obtained cured product, the transmittance in the wavelength regions of 400 to 800 nm and 400 to 450 nm was measured using a spectrophotometer (U-3310, Hitachi High-Technologies Corporation). As a result, the transmittance at 400 to 800 nm was 90% or more, and the transmittance at 400 to 450 nm was 90% or more.

(Heat resistant, moisture resistant adhesive)
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 in which a polarizing film is attached to one side, and the ultraviolet curable adhesive composition obtained on one side has a film thickness of 200 μm. After coating so as to be, the other was bonded to the coated surface. The resin composition was irradiated with ultraviolet rays having an integrated light intensity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less), and the resin composition was cured to prepare a sample for adhesiveness evaluation. Using this, a heat resistance test at 85 ° C. and a moisture resistance test at 60 ° C. 90% RH were performed, and the mixture was left for 100 hours. In the evaluation sample, peeling of the cured resin product from the glass or polarizing film was visually confirmed, 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 Blemmer LA (lauryl acrylate) manufactured by Nichiyu Co., Ltd., 18 parts by mass of Clearon M-105 (aromatically modified hydrogenated terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nikko Nisseki Energy Co., Ltd., GI-2000 manufactured by Nippon Soda Co., Ltd. (1,2-Hydrogenated polybutadiene glycol) 20 parts by mass, Osaka Organic Chemical Industry Co., 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) and 0.5 parts by mass of IRGACURE184 (1-hydroxycyclohexylphenylketone) manufactured by BASF were heated and mixed at 70 ° C. to obtain the 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 Blemmer LA (lauryl acrylate) manufactured by Nichiyu Co., Ltd., 18 parts by mass of Clearon M-105 (aromatically modified hydrogenated terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nikko Nisseki Energy Co., Ltd., GI-2000 manufactured by Nippon Soda Co., Ltd. (1,2-Hydrogenated polybutadiene glycol) 20 parts by mass, Osaka Organic Chemical Industry Co., 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) and 0.5 parts by mass of IRGACURE184 (1-hydroxycyclohexylphenylketone) manufactured by BASF were heated and mixed at 70 ° C. to obtain the 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 Blemmer LA (lauryl acrylate) manufactured by Nichiyu Co., Ltd., 18 parts by mass of Clearon M-105 (aromatic modified hydrogenated terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 10 parts by mass of LV-100 (polybutene) manufactured by JX Nikko Nisseki Energy Co., Ltd., T-5652 manufactured by Asahi Kasei Chemicals Co., Ltd. (Polycarbonate polyol) 20 parts by mass, 4-HBA (4-hydroxybutyl acrylate) manufactured by Osaka Organic Chemical Industry Co., Ltd., 3 parts by mass, Speed Cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) manufactured by LAMBSON. 0.5 parts by mass and 0.5 parts by mass of IRGACURE184 (1-hydroxycyclohexylphenyl ketone) manufactured by BASF were heated to 70 ° C. and mixed to obtain the resin composition of the present invention.

Examples 4 to 6 are shown in Table 2, and the following evaluations were performed.

(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 refractive index meter (DR-M2: manufactured by Atago Co., Ltd.).

(Curing shrinkage rate)
Two 1 mm thick slide glasses coated with a fluorine-based mold release agent were prepared, and the obtained ultraviolet curable resin composition was coated on one of the mold release agent coated surfaces so that the film thickness was 200 μm. .. After that, two slide glasses were attached so that the release agent-coated surfaces faced each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light intensity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless). Then, the two slide glasses were peeled off to prepare a cured product for measuring the film specific gravity. The specific gravity (DS) of the cured product was measured according to the JIS K7112 B method. Further, the liquid specific gravity (DL) of the resin composition was measured at 25 ° C. From the measurement results of DS and DL, the curing shrinkage rate was calculated from the following formula.
Curing shrinkage rate (%) = (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. Then, the two PET films were laminated so that the release surfaces faced each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light amount of 3000 mJ / cm ^{2 through} a PET film with a high-pressure mercury lamp (80 W / cm, ozoneless). Then, the two PET films were peeled off to prepare a cured product for measuring the rigidity. The rigidity was measured by ARES (manufactured by TA Instruments).

(Transmittance)
Two slide glasses having a thickness of 1 mm were prepared, and one of them was coated with the obtained ultraviolet curable resin composition so that the film thickness after curing was 200 μm. After that, two slide glasses were pasted together. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light intensity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless) to prepare a cured product for transmittance measurement. Regarding the transparency of the obtained cured product, the transmittance in the wavelength regions of 400 to 800 nm and 400 to 450 nm was measured using a spectrophotometer (U-3310, Hitachi High-Technologies Corporation). As a result, the transmittance at 400 to 800 nm was 90% or more, and the transmittance at 400 to 450 nm was 90% or more.

(Heat resistant, moisture resistant adhesive)
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 in which a polarizing film is attached to one side, and the ultraviolet curable resin composition obtained on one side has a film thickness of 200 μm. After coating as described above, the other was bonded to the coated surface. The resin composition was irradiated with ultraviolet rays having an integrated light intensity of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less), and the resin composition was cured to prepare a sample for adhesiveness evaluation. Using this, a heat resistance test at 85 ° C. and a moisture resistance test at 60 ° C. 90% RH were performed, and the mixture was left for 100 hours. In the evaluation sample, peeling of the cured resin product from the glass or polarizing film was visually confirmed, but there was no peeling.

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

(Whitening resistance)
Two 1 mm-thick slide glasses were prepared, coated on one slide glass so that the film thickness of Examples 4 to 6 was 200 μm, and the other slide glass was attached to the coated surface. Then, the composition was irradiated with ultraviolet rays having an integrated light intensity of 4000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, with an ozoneless / IR cut filter). After putting the obtained test piece in an environment of 80 ° C. and 85% RH for 48 hours, the state of the film 15 minutes after being taken out to the environment of 25 ° C. and 45% RH and the state of the cured film 3 hours after being taken out are shown. It was confirmed visually.
A slide glass having a thickness of 1 mm was coated so that the film thickness of Examples 4 to 6 was 200 μm, and a release PET film was attached to the coated surface. Then, the composition was irradiated with ultraviolet rays having an integrated light intensity of 4000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, equipped with an ozoneless / IR cut filter) through the peeled PET film. After putting the obtained conjugate in an environment of 80 ° C. and 85% RH for 48 hours, the state of the membrane 15 minutes after being taken out to the environment of 25 ° C. and 45% RH and the state of the cured film 3 hours after being taken out are shown. It was confirmed visually. As a result of evaluation, all the compositions of Examples 4 to 6 were ◯.

〇: No whitening of the film Δ: Whitening after 15 minutes, but not whitening after 3 hours ×: Whitening after 15 minutes and whitening after 3 hours

(Adhesive strength 1)
After laminating a PET film and a glass plate having a thickness of 1 mm so that the cured film thickness of Examples 1 to 6 is 200 μm, a high-pressure mercury lamp (80 W / cm, with an ozoneless / IR cut filter) is passed through the PET film. The composition was irradiated with ultraviolet rays having an integrated light amount of 4000 mJ / cm ² . Adhesion was measured using the obtained bonded body by a method conforming to JISZ0237. It is necessary to fix the joint of the PET film and the glass plate with a thickness of 1 mm horizontally so that the PET film is on the upper surface, and to peel it off vertically (90 ° upward) from the edge of the PET film. The force was measured. Both the evaluation result and the judgment result were ○.

〇: Adhesive strength 6.0 N / cm or more Δ: Adhesive strength 1.5 N / cm or more and less than 6.0 N / cm ×: Adhesive strength less than 1.5 N / cm

(Curing rate)
Two 1 mm thick slide glasses were prepared, coated so that the film thickness of Examples 1 to 6 was 200 μm, and the other slide glass was attached to the coated surface. Then, the composition was irradiated with ultraviolet rays having an integrated light intensity of 100 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, equipped with an ozoneless / IR cut filter). Then, the slide glass was peeled off and the state of the composition was confirmed. The evaluation results were all ○.

〇: No fluidity ×: Insufficient curing and fluidity

(Adhesive strength 2) A glass joint was obtained according to the following experimental example.
Experimental Example 1: Two glass plates having a size of 2 cm in width × 3.5 cm in length × 1 mm in thickness are prepared, and the composition C is placed in the center of one of the glass plates so as to form a circle having a thickness of 200 μm and a diameter of 1 cm. Was applied to. After that, an electrodeless ultraviolet lamp (D valve manufactured by Heleus Noble Light Fusion Ubuy) was used for the obtained coating layer, and the integrated light amount was 100 mJ from the atmosphere side through an ultraviolet cut filter that blocks wavelengths of 320 nm or less. By irradiating with ultraviolet rays of / cm ² , a cured product layer having a cured portion existing on the lower side (glass plate side) of the coating layer and an uncured portion existing on the upper side (atmosphere side) of the coating layer was formed. At this time, the ratio of the maximum illuminance in the range of 200 to 320 nm was 3 for the ultraviolet rays irradiated to Examples 1 to 6 when the maximum illuminance in the range of 320 nm to 450 nm was 100. Furthermore, 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 at 90 ° C.), and the integrated light amount is 2000 mJ / through the glass of the bonded side. The cured resin layer was cured by irradiating with ultraviolet rays of cm ² , and a bonded body was obtained.
Experimental Example 2: Exists on the lower side (glass plate side) of the coating layer in the same manner as in Experimental Example 1 except that the ultraviolet cut filter that blocks wavelengths of 320 nm or less is changed to a glass plate having a thickness of 0.5 mm. A cured product layer having a cured portion and an uncured portion existing on the upper side (atmosphere side) of the coating layer was formed. The ultraviolet rays irradiated to Examples 1 to 6 at this time had a maximum illuminance ratio of 21 in the range of 200 to 320 nm, where the maximum illuminance in the range of 320 nm to 450 nm was 100. Furthermore, 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 at 90 ° C.), and the integrated light amount is 2000 mJ / through the glass of the bonded side. The cured resin layer was cured by irradiating with ultraviolet rays of cm ² , and a bonded body was obtained.
Experimental Example 3: A cured portion existing on the lower side (glass plate side) of the coating layer and the upper side of the coating layer in the same manner as in Experimental Example 1 except that an ultraviolet cut filter that blocks wavelengths of 320 nm or less was not used. A cured product layer having an uncured portion existing on the (atmosphere side) was formed. At this time, the ratio of the maximum illuminance in the range of 200 to 320 nm was 45 for the ultraviolet rays irradiated to the composition C, assuming that the maximum illuminance in the range of 320 nm to 450 nm was 100. Furthermore, 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 at 90 ° C.), and the integrated light amount is 2000 mJ / through the glass of the bonded side. The cured resin layer was cured by irradiating with ultraviolet rays of cm ² , and a bonded body was obtained.
Experimental Example 4: Using an applicator, the composition C was applied on a 100 mm × 100 mm thick 100 μm peeling PET film so as to have a thickness of 200 μm, and then covered with a 25 μm thick peeling PET film. It was. Next, the composition C was cured by irradiating ultraviolet rays with an integrated light amount of 2000 mJ / cm ² using an electrodeless ultraviolet lamp (D valve manufactured by Heleus Noble Light Fusion Ubuy) to have a thickness of 200 μm. A transparent adhesive sheet was obtained. Then, the adhesive sheet was cut into a circle having a diameter of 1 cm, and then the peeling PET film having a thickness of 100 μm was peeled off. Next, the transparent adhesive sheet from which the peeled PET film was peeled off was attached to the center of a glass plate having a width of 2 cm, a length of 3.5 cm, and a thickness of 1 mm by reciprocating a rubber roller having a mass of 1 kg and a width of 20 mm once. .. Then, a peeling PET film having a thickness of 25μ is peeled off, and a glass plate having a size of 2 cm in width × 3.5 cm in length × 1 mm in thickness is attached to a transparent adhesive sheet in a cross shape (direction intersecting at 90 ° C.) to form a bonded body. Got

One glass plate of the bonded product obtained in Experimental Examples 1 to 4 was fixed, and the other glass plate was peeled off in the vertical upward direction, and the state of the cured film after peeling was visually confirmed. The evaluation results were all ○. The cohesive peeling means that the cured resin product itself is cut, not the interface between the substrate and the cured resin product, and the interface peeling means that the interface between the substrate and the cured resin product is peeled off.

〇: Coagulation peeling only Δ: Coagulation peeling part and interfacial peeling part occurred at the same time ×: Interfacial peeling only

From the above results, the ultraviolet curable resin composition and the manufacturing method of the present invention have good curability, high whitening resistance, strong adhesive force to the base material, and are directly applied to the base material to be bonded. After that, it is hardened by irradiating with ultraviolet rays, and it can be seen that it has high adhesive strength even when the other base material is bonded.

Further, the following evaluations were carried out using the obtained Examples 1 to 6 of the present invention.

(Curing shrinkage rate)
Two 1 mm thick slide glasses coated with a fluorine-based mold release agent were prepared, and the composition was applied to one of the slide glass coated with the mold release agent so that the film thickness was 200 μm. After that, two slide glasses were attached so that the release agent-coated surfaces faced each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light intensity of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless). Then, the two slide glasses were peeled off to prepare a cured product for measuring the specific gravity of the film. The specific gravity (DS) of the cured product was measured according to the JIS K7112 B method. Further, the liquid specific gravity (DL) of the resin composition was measured at 25 ° C. When the curing shrinkage rate was calculated from the measurement results of DS and DL from the following formula, it was less than 3.0%.
Curing shrinkage rate (%) = (DS-DL) ÷ DS × 100

(Heat resistant, moisture resistant adhesive)
A slide glass having a thickness of 0.8 mm and an acrylic plate having a thickness of 0.8 mm were prepared, and the composition obtained on one of them was applied so as to have a film thickness of 200 μm, and then the other was bonded to the coated surface. .. The resin composition was irradiated with ultraviolet rays having an integrated light intensity of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless), and the resin composition was cured to prepare a sample for adhesiveness evaluation. This was left to stand for 250 hours in an environment of 85 ° C. and 85% RH. In the evaluation sample, peeling of the slide glass or acrylic plate from the cured resin product was visually confirmed, but there was no peeling.

(Flexibility)
The obtained composition was sufficiently cured, and the durometer E hardness was measured using a durometer hardness tester (type E) by a method conforming to JIS K7215, and the flexibility was evaluated. More specifically, the ultraviolet curable resin composition was poured into a columnar mold so as to have a film thickness of 1 cm, and the resin composition was sufficiently cured by irradiating with ultraviolet rays. The hardness of the obtained cured product was measured with a durometer hardness tester (type E). As a result, the measured value was less than 10, and the flexibility was excellent.

(transparency)
Two 1 mm thick slide glasses coated with a fluorine-based mold release agent were prepared, and the obtained composition was applied to one of the slide glass coated with the mold release agent so that the film thickness after curing was 200 μm. did. After that, two slide glasses were attached so that the release agent-coated surfaces faced each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an integrated light intensity of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozoneless). Then, the two slide glasses were peeled off to prepare a cured product for measuring transparency. Regarding the transparency of the obtained cured product, the transmittance in the wavelength regions of 400 to 800 nm and 400 to 450 nm was measured using a spectrophotometer (U-3310, Hitachi High-Technologies Corporation). As a result, the transmittance at 400 to 800 nm was 90% or more, and the transmittance at 400 to 450 nm was 90% or more.

(Curability of resin under light-shielding part)
The composition is applied to 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 is formed on the transparent substrate having the light-shielding portion (width 5 mm) on the outer peripheral portion, and the film thickness is 125 μm on each substrate. It was applied so as to be. Then, an electrodeless ultraviolet lamp (D valve manufactured by Heleus Noble Light Fusion Ubuy) was used for the obtained coating layer, and the integrated light amount was 100 mJ / from the atmosphere side through an ultraviolet cut filter that blocks wavelengths of 320 nm or less. Ultraviolet irradiation of cm ² was performed to form a cured product layer having a cured portion and an uncured portion existing on the atmospheric side. At this time, the ratio of the maximum illuminance in the range of 200 to 320 nm was 3 for the ultraviolet rays irradiated to the composition, assuming that the maximum illuminance in the range of 320 nm to 450 nm was 100.
After that, the liquid crystal display unit and the transparent substrate having the light-shielding portion were laminated so that the uncured portions faced each other. Finally, with an ultra-high pressure mercury lamp (TOSCURE752, manufactured by Harison Toshiba Lighting Corp.), the cured resin layer is cured by irradiating ultraviolet rays with an integrated light amount of 2000 mJ / cm ² from the glass substrate side having a light-shielding portion to cure the optical member. Made. The transparent substrate was removed from the obtained optical member, and the cured resin layer of the light-shielding portion 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.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications and modifications can be made without departing from the spirit and scope of the invention.
This application is based on the Japanese patent application (2014-120621) filed on June 11, 2014 and the Japanese patent application (2015-114861) filed on June 5, 2015. The whole is incorporated by citation. Also, all references cited here are taken in as a whole.

1 Liquid crystal display unit, 2 Transparent substrate with light-shielding part, 3 Transparent substrate, 4 Light-shielding part, 5 Ultraviolet curable resin composition (ultraviolet curable resin composition), 6 Cured material layer with uncured part, 7 Resin curing Material layer, 8 UV

Claims (13)

A resin composition used for bonding at least two optical substrates, a monofunctional (meth) acrylate (A) having a branched chain and a fat chain having 10 to 30 carbon atoms, a softening component (B), and the like. photopolymerizable oligomer (C), photopolymerization initiator (E) seen including,
Further, an ultraviolet curable resin composition for a touch panel containing a photopolymerizable monomer (D) other than the component (A).
The component (C) contains urethane (meth) acrylate having a weight average molecular weight of 1000 to 60,000 obtained by reacting hydrogenated polybutadiene polyol, polyisocyanate and hydroxyl group-containing (meth) acrylate.
The component (D) is 4-hydroxybutyl acrylate.
As a monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having a branched chain, 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.)
Contains the ingredients indicated by
4-Hydroxybutyl acrylate: An ultraviolet curable resin composition for a touch panel, wherein the ratio (weight ratio) of the components of the above formula (10) is 1: 3 to 1:25 . The photopolymerizable oligomer (C) is further selected from the group consisting of a (meth) acrylate having a polyisoprene or a hydrogenated polyisoprene skeleton, a polybutadiene, or a (meth) acrylate having a hydrogenated polybutadiene skeleton. The ultraviolet curable resin composition for a touch panel according to claim 1, wherein the resin composition contains. The ultraviolet curable resin composition for a touch panel according to claim 1 or 2 , wherein the softening component (B) contains either one or both of a hydroxyl group-containing polymer and a liquid terpene resin. The ultraviolet curable resin for a touch panel according to any one of claims 1 to 3 , which contains 1 to 30% by weight of a monofunctional (meth) acrylate (A) having a fat chain having 10 to 30 carbon atoms having a branched chain. Composition. Further 'comprises, the (D (A) other than the component photopolymerizable monomer (D)' touch panel according to any one of claim 1 to 4) component contains no photopolymerizable monomer hydroxyl UV curable resin composition for. The ultraviolet curable type for a touch panel according to any one of claims 1 to 5 , wherein the monofunctional (meth) acrylate (A) having a branched chain and having 10 to 30 carbon atoms contains isostearyl acrylate. Resin composition. A method for manufacturing an optical member in which at least two optical substrates having the following steps 1 and 2 are attached to each other.
(Step 1) The ultraviolet curable resin composition for a touch panel according to any one of claims 1 to 6 is applied to at least one optical substrate to form a coating layer, and the coating layer is coated. Step of obtaining an optical base material having a cured product layer by irradiating with ultraviolet rays (step 2) Another optical base material is attached to the cured product layer of the optical base material obtained in step 1 or is used. A step of laminating a cured product layer of another optical base material obtained in step 1. The production according to claim 7 , wherein the cured product layer obtained in the step 1 has a cured portion existing on the optical base material side and an uncured portion existing on the side opposite to the optical base material side. Method. The manufacturing method according to claim 8 , further comprising the following step 3 after the steps 1 and 2.
(Step 3) A step of irradiating a cured product layer having an uncured portion in the bonded optical base material with ultraviolet rays to cure the cured product layer. The ultraviolet rays irradiated to the ultraviolet curable resin composition in the step 1 are characterized in that 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. The method for manufacturing an optical member according to any one of claims 7 to 9 . The ultraviolet rays irradiated to the ultraviolet curable resin composition in the step 1 are characterized in that 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. The method for manufacturing an optical member according to any one of claims 7 to 9 . A cured product obtained by irradiating the ultraviolet curable resin composition according to any one of claims 1 to 6 with active energy rays. A touch panel comprising the ultraviolet curable resin composition according to any one of claims 1 to 6 .