JP2020055896A - Photocurable resin composition and method for forming resin cured product - Google Patents

Abstract

To provide a photocurable resin composition capable of easily forming a resin cured product containing parts different in elastic modulus or hardness and a method for forming a resin cured product using the same.SOLUTION: There is provided a photocurable resin composition comprising (A) a photopolymerizable compound, (B-1) a first photopolymerization initiator and (B-2) a second photopolymerization initiator. The first photopolymerization initiator has an absorption coefficient at a wavelength of 405 nm of 7 mL/g cm or more and an absorption coefficient at a wavelength of 365 nm of 38 mL/g cm or more, the second photopolymerization initiator may have an absorption coefficient at a wavelength of 405 nm of 5 mL/g cm or less and an absorption coefficient at a wavelength of 365 nm of 38 mL/g cm or more, the first photopolymerization initiator has an absorption coefficient at a wavelength of 405 nm of 7 mL/g cm or more and an absorption coefficient at a wavelength of 313 nm of 150 mL/g cm or more, the second photopolymerization initiator may have an absorption coefficient at a wavelength of 405 nm of 5 mL/g cm or less and an absorption coefficient at a wavelength of 313 nm of 150 mL/g cm or more, the first photopolymerization initiator has an absorption coefficient at a wavelength of 365 nm of 60 mL/g cm or more and an absorption coefficient at a wavelength of 313 nm of 150 mL/g cm or more and the second photopolymerization initiator may have an absorption coefficient at a wavelength of 365 nm of 60 mL/g cm or less, which is one-fourth the first photopolymerization initiator and an absorption coefficient at a wavelength of 313 nm of 150 mL/g cm or more.SELECTED DRAWING: None

Description

  The present invention relates to a photocurable resin composition and a method for forming a cured resin.

  An image display device used for an information terminal such as a smart phone or a mobile terminal includes an image display unit (including a liquid crystal panel and a cover glass) having an image display surface, and a frame unit supporting the image display unit. I have.

  Conventionally, such an image display device is configured such that an image display portion and a frame portion are adhered and fixed with a pressure-sensitive adhesive tape, and a gap between the image display portion and the frame portion is made of resin when waterproofness or dustproofness is required. (For example, see Patent Document 1).

JP-A-2006-200636A

  By the way, in the above-mentioned image display device, the role of the sealing material is waterproofing for preventing moisture from entering the inside of the image display device and shock absorption for preventing damage to the image display portion. Sealing materials suitable for these purposes have different physical properties and different locations. For example, a sealing material suitable for waterproofing is a high-elasticity resin or a high-hardness resin, and is desirably provided on the surface side. A sealing material suitable for shock absorption is a low-elasticity resin or a low-hardness resin, and is internally provided. It is desirable to be provided. On the other hand, when sealing is performed using a plurality of resins, the manufacturing process becomes complicated, and thus it is desirable that the sealing be performed simply with one liquid.

  As described above, there is a demand for easily forming a cured resin containing portions having different elastic moduli or hardness from one resin composition.

  The present invention has been made in view of the above circumstances, a photocurable resin composition capable of easily forming a cured resin containing a portion having a different elastic modulus or hardness, and a cured resin using the same. It is an object to provide a forming method.

  The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a specific light irradiation was performed on a photocurable resin composition containing a polymerizable compound and at least two types of specific photopolymerization initiators. It was found that a resin cured product containing portions having different elastic modulus or hardness can be obtained by performing the above-mentioned curing to complete the present invention.

  The present invention comprises (A) a photopolymerizable compound, (B-1) a first photopolymerization initiator, and (B-2) a second photopolymerization initiator, and a first photopolymerization initiator. Has an extinction coefficient at a wavelength of 405 nm of 7 mL / g · cm or more, and an extinction coefficient at a wavelength of 365 nm of 38 mL / g · cm or more, and the second photopolymerization initiator has an extinction coefficient of 5 mL at a wavelength of 405 nm. / G · cm or less, and a first photocurable resin composition having an absorption coefficient at a wavelength of 365 nm of 38 mL / g · cm or more.

  According to the first photocurable resin composition of the present invention, light irradiation containing light having a wavelength of 405 nm and light irradiation containing light having a wavelength of 365 nm are performed, or light having a wavelength of 405 nm and light having a wavelength of 365 nm are emitted. By performing the included light irradiation, it is possible to easily form a cured resin including portions having different elastic modulus or hardness. That is, when the above-mentioned light irradiation is performed on the photocurable resin composition, light of 365 nm on the short wavelength side hardly reaches the deep part of the resin composition, and light of 405 nm on the long wavelength side is light on the short wavelength side. Sufficient illuminance can be easily obtained from the surface to the deep part of the resin composition as compared with light of 365 nm. Therefore, on the surface side of the photocurable resin composition, the reaction rate of the photopolymerizable compound is increased by consuming both the first photopolymerization initiator and the second photopolymerization initiator, and the high elastic modulus The first photopolymerization initiator is not consumed on the deep side, and the reaction rate of the photopolymerizable compound is suppressed by consuming the second photopolymerization initiator. The elastic modulus or the hardness can be reduced.

  The present invention also includes (A) a photopolymerizable compound, (B-1) a first photopolymerization initiator, and (B-2) a second photopolymerization initiator, and comprises a first photopolymerization initiator. The agent has an extinction coefficient of 7 mL / g · cm or more at a wavelength of 405 nm and an extinction coefficient of 313 nm or more of 150 mL / g · cm, and the second photopolymerization initiator has an extinction coefficient of 405 nm. Provided is a second photocurable resin composition having an extinction coefficient of 5 mL / g · cm or less and a wavelength of 313 nm of 150 mL / g · cm or more.

  According to the second photocurable resin composition of the present invention, light irradiation containing light having a wavelength of 405 nm and light irradiation containing light having a wavelength of 313 nm are performed, or light having a wavelength of 405 nm and light having a wavelength of 313 nm are used. By carrying out light irradiation containing (1), it becomes possible to easily form a cured resin containing portions having different elastic modulus or hardness. The mechanism for controlling the elastic modulus or hardness is the same as that of the first photocurable resin composition.

  The present invention also includes (A) a photopolymerizable compound, (B-1) a first photopolymerization initiator, and (B-2) a second photopolymerization initiator, and comprises a first photopolymerization initiator. The agent has an extinction coefficient at a wavelength of 365 nm of 60 mL / g · cm or more, and an extinction coefficient of a wavelength of 313 nm is 150 mL / g · cm or more, and the second photopolymerization initiator has an extinction coefficient at a wavelength of 365 nm. A third photocurable resin composition having an extinction coefficient at a wavelength of 313 nm of not less than 60 mL / g · cm and not more than 1/4 of the first photopolymerization initiator and having an absorption coefficient of not less than 150 mL / g · cm; I will provide a.

  According to the third photocurable resin composition of the present invention, light irradiation containing light having a wavelength of 365 nm and light irradiation containing light having a wavelength of 313 nm are performed, or light having a wavelength of 365 nm and light having a wavelength of 313 nm are used. By carrying out light irradiation containing (1), it becomes possible to easily form a cured resin containing portions having different elastic modulus or hardness. The mechanism for controlling the elastic modulus or hardness is the same as that of the first photocurable resin composition.

In the first, second, and third photocurable resin compositions of the present invention, the content I of the first photopolymerization initiator from the viewpoint of increasing the difference in hardness between the surface and the deep part of the cured resin product. is preferably ₁ mass ratio _I 1 / _{I 2} between the content _{I 2} of the second photopolymerization initiator is 10 to 1/1000.

  The first, second and third photocurable resin compositions of the present invention may further contain (C) an ultraviolet absorber. In this case, it is easy to adjust the depth of the high elasticity portion or the high hardness portion. For example, when the blending amount of the ultraviolet absorber is increased, light hardly reaches a deep portion, and a high elasticity portion or a high hardness portion can be made shallower.

The first, second, and third photocurable resin compositions of the present invention may satisfy all of the following conditions (a), (b), and (c).
(A) When the conversion of the component (A) is 90 to 100%, the hardness is Shore D30 to D90.
(B) When the conversion of the component (A) is 80% or more and less than 90%, the hardness is Shore A20 to D30.
(C) When the conversion of the component (A) is less than 80%, the hardness is not more than Shore A20.

  According to such a photocurable resin composition, by adjusting the exposure amount in light irradiation, the surface side having the increased reaction rate has the physical properties of (a) above, and the deeper side having suppressed the reaction rate. In the above, a cured resin having the above physical properties (b) to (c) can be formed. The cured resin having such an elastic modulus or hardness can have both a high elasticity portion or a high hardness portion suitable for waterproofing and adhesion and a low elasticity portion or a low hardness portion suitable for shock absorption.

  The present invention can also provide the following methods (1) to (6) for forming a cured resin using the photocurable resin composition according to the present invention.

(1) a first exposure step of irradiating a light-irradiated body made of the first photocurable resin composition with a first light, and a photo-curable resin composition irradiated with the first light. A second exposure step of irradiating the second light, wherein the first light includes light having a wavelength of 405 nm and the second light includes light having a wavelength of 365 nm, or the first light includes light having a wavelength of 365 nm. The second light includes light having a wavelength of 405 nm.

(2) a first exposure step of irradiating the light-irradiated body made of the second photocurable resin composition with first light, and a photocurable resin composition irradiated with the first light. A second exposure step of irradiating the second light, wherein the first light includes light having a wavelength of 405 nm and the second light includes light having a wavelength of 313 nm, or the first light includes light having a wavelength of 313 nm. The second light includes light having a wavelength of 405 nm.

(3) a first exposure step of irradiating the light-irradiated body made of the third photocurable resin composition with first light, and a photo-curable resin composition irradiated with the first light. A second exposure step of irradiating the second light, wherein the first light includes light having a wavelength of 365 nm and the second light includes light having a wavelength of 313 nm, or the first light includes light having a wavelength of 313 nm. The second light includes light having a wavelength of 365 nm.

(4) An exposure step of irradiating a light irradiation object made of the first photocurable resin composition with light is included, and the light includes light having a wavelength of 405 nm and light having a wavelength of 365 nm.

(5) An exposure step of irradiating the light-irradiated body made of the second photocurable resin composition with light is included, and the light includes light having a wavelength of 405 nm and light having a wavelength of 313 nm.

(6) An exposure step of irradiating a light-irradiated body made of the third photocurable resin composition with light is included, and the light includes light having a wavelength of 365 nm and light having a wavelength of 313 nm.

  In any of the above methods, it becomes possible to easily form a cured resin containing portions having different elastic modulus or hardness.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a photocurable resin composition capable of easily forming a cured resin including portions having different elastic moduli or hardness and a method for forming a cured resin using the same.

FIG. 1 is a view for explaining one embodiment of a method for forming a cured resin according to the present invention. FIG. 2 is a schematic cross-sectional view showing an image display device provided with a cured resin formed by the method for forming a cured resin of the present embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments. In this specification, “(meth) acrylic acid” means acrylic acid or methacrylic acid, and “(meth) acrylate” means acrylate or methacrylate corresponding thereto. “A or B” may include either one of A and B, and may include both.

  Further, in this specification, the term “layer” includes, when observed as a plan view, a structure partially formed in addition to a structure formed over the entire surface. In this specification, the term “step” is used not only for an independent step but also for the case where the intended action of the step is achieved even if it cannot be clearly distinguished from other steps. included. Further, the numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

  Further, in the present specification, the content of each component in the composition, if there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, the total of the plurality of substances present in the composition Means quantity. The exemplified materials may be used alone or in combination of two or more unless otherwise specified.

  In addition, in the numerical ranges described in stages in this specification, the upper limit or the lower limit of the numerical range of a certain stage may be replaced with the upper limit or the lower limit of the numerical range of another stage. Further, in the numerical ranges described in this specification, the upper limit or the lower limit of the numerical ranges may be replaced with the values shown in the embodiments.

<Photocurable resin composition>
The photocurable resin composition of the present embodiment contains (A) a photopolymerizable compound and (B) a photopolymerization initiator. The photocurable resin composition may contain (C) an ultraviolet absorber, (D) an antioxidant, (E) a chain transfer agent, (F) a plasticizer, and other additives as necessary. You may.

((A) Photopolymerizable compound)
Examples of the component (A) include compounds having a polymerizable unsaturated group. Examples of the polymerizable unsaturated group include a carbon-carbon double bond such as a vinyl group (ethenyl group), an ethynyl group, an allyl group, a (meth) acryloyl group, a (meth) acryloyloxy group, and a (meth) acryloylamino group. And a group having: As the component (A), one type can be used alone, or two or more types can be used in combination.

  In the present embodiment, the component (A) includes a (meth) acryloyl group-containing monomer (hereinafter, sometimes referred to as a (A-1) component) and a (meth) acryloyl group-containing oligomer (hereinafter, (A-2)). Component).

  As the component (A-1), a monofunctional, bifunctional, or trifunctional or higher monomer can be used.

  Examples of the monofunctional (meth) acryloyl group-containing monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, butoxyethyl ( (Meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl ( (Meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, Allyl (meth) acrylate, behenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) Acrylate, methoxy polyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, mono (2- (meth) acryloyloxyethyl) succinate, (meth) Aliphatic (meth) a such as a reaction product of acrylic acid and glycidyl ester (for example, “Kajura E-10” manufactured by Momentive Performance Materials, Inc.) Relates: cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, mono (2- (meth) Alicyclic (meth) acrylates such as) acryloyloxyethyl) tetrahydrophthalate and mono (2- (meth) acryloyloxyethyl) hexahydrophthalate.

  Examples of the bifunctional (meth) acryloyl group-containing monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol. Di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethoxy Polypropylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acryle G, neopentyl glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3 -Propanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, glycerin di (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, Aliphatic (meth) acrylates such as ethoxylated 2-methyl-1,3-propanediol di (meth) acrylate; cyclohexane dimethanol (meth) acrylate, ethoxylated cyclohexane dimethanol (meth) acrylate, and propoxylated cyclohexane dimethanol ( Meta) ac Rate, ethoxylated propoxylated cyclohexanedimethanol (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, ethoxylated tricyclodecanedimethanol (meth) acrylate, propoxylated tricyclodecanedimethanol (meth) acrylate, ethoxylated Propoxylated tricyclodecane dimethanol (meth) acrylate, ethoxylated hydrogenated bisphenol A di (meth) acrylate, propoxylated hydrogenated bisphenol A di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol A di (meth) acrylate, Ethoxylated hydrogenated bisphenol F di (meth) acrylate, propoxylated hydrogenated bisphenol F di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol F di (meth) acryl And alicyclic (meth) acrylates such as acrylate.

  Examples of trifunctional or higher-functional (meth) acryloyl group-containing monomers include, for example, trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and ethoxylated propoxy. Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated propoxylated pentaerythritol tri (meth) acrylate, Pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol Tiger (meth) acrylate, ethoxylated propoxylated pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) aliphatic acrylates such as (meth) acrylate.

  As the component (A-1), a (meth) acrylamide-based monomer can be used.

  (Meth) acrylamide-based monomers include (meth) acrylamide, methyl (meth) acrylamide, dimethyl (meth) acrylamide, ethyl (meth) acrylamide, diethyl (meth) acrylamide, n-propyl (meth) acrylamide, and di-n- Propyl (meth) acrylamide, isopropyl (meth) acrylamide, diisopropyl (meth) acrylamide, n-butyl (meth) acrylamide, di-n-butyl (meth) acrylamide, isobutyl (meth) acrylamide, diisobutyl (meth) acrylamide, tert- Butyl (meth) acrylamide, di-tert-butyl (meth) acrylamide, n-pentyl (meth) acrylamide, di-n-pentyl (meth) acrylamide, n-hexyl (meth) acrylamide Ruamido, di -n- hexyl (meth) acrylamide, cyclohexyl (meth) acrylamide, dicyclohexyl (meth) acrylamide, (meth) acryloyl morpholine.

  Examples of the component (A-2) include a (meth) acrylate compound having a urethane bond, a (meth) acrylate compound having an ester bond, and a (meth) acrylate compound having an ether bond.

  The (meth) acrylate compound having a urethane bond can have at least one (meth) acryloyl group or (meth) acryloyloxy group.

  Examples of the (meth) acrylate compound having a urethane bond include a (meth) acrylic acid-based monomer having an OH group at the β-position and isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1,6- Reaction product with diisocyanate compound such as hexamethylene diisocyanate, 2-isocyanatoethyl acrylate, reaction product of 2-isocyanatoethyl methacrylate with polyalcohol such as polycarbonate diol, tris ((meth) acryloxytetraethylene glycol isocyanate) Hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, PO-modified urethane di (meth) acrylate, EO and PO-modified urethane di (meth) acrylate, polybutadiene-modified urethane Nji (meth) acrylate and carboxyl group-containing urethane (meth) acrylate. Urethane oligomers are also preferably used as the (meth) acrylate compound having a urethane bond.

  Examples of the (meth) acrylate compound having an ester bond include a (meth) acrylate having a polymer skeleton obtained by dehydration-condensation of a polycarboxylic acid (dicarboxylic acid) and a polyalcohol (diol), and a modified polybutadiene (meth) Acrylate, polyisoprene-modified (meth) acrylate, or the like can be used.

  As the (meth) acrylate compound having an ether bond, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, or the like can be used.

  The weight average molecular weight of the component (A-2) is preferably 300 or more, more preferably 400 or more, and still more preferably 500 or more, from the viewpoint of filling properties and shape retention in a liquid state. Further, the weight average molecular weight of the component (A-2) is preferably 1,000,000 or less, more preferably 750,000 or less, and still more preferably 500000 or less, from the viewpoint of reducing the stringiness at the time of coating film formation. The weight average molecular weight is measured by gel permeation chromatography (GPC), and a value converted into standard polystyrene is used.

  Commercially available products include, for example, TE-2000 (product name, manufactured by Nippon Soda Co., Ltd.), EBECRYL220, EBECRYL600, EBECRYL3700, EBECRYL3703 (product name, manufactured by Daicel Ornics Co., Ltd.).

  The component (A) may contain a polymerizable compound other than the components (A-1) and (A-2). Examples of the polymerizable compound include a compound having a cyclic ether and a compound having an unsaturated bond other than (meth) acrylate. Examples of the cyclic ether include an epoxy group, a glycidyl group, an oxetane group, and the like. Examples of the compound having an unsaturated bond other than (meth) acrylate include an allyl ether, an allyl group, and a vinyl group.

  Commercial products of the compound having a cyclic ether include, for example, CEL-8000, CEL-2021P (product names, manufactured by Daicel Co., Ltd.) and OXBP (product names, manufactured by Toagosei Co., Ltd.). Examples of commercially available compounds having an unsaturated bond include, for example, TAIC (manufactured by Mitsubishi Chemical Corporation, product name), G-1000 (manufactured by Nippon Soda Co., Ltd., product name), EHVE, HBVE, DEGV, EHVE (all, Maruzen Petrochemical Co., Ltd., product name), Crossmer U01 (Nippon Carbide Industry Co., Ltd., product name) and the like.

  In the present embodiment, it is preferable to use a combination of the component (A-1) and the component (A-2).

  The total content of the component (A-1) and the component (A-2) in the photocurable resin composition is such that the non-polymerizable component does not bleed out, and the surface and the deep portion of the cured resin material. From the viewpoint of facilitating the design that causes a difference in hardness with the above, the amount is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more based on the total mass of the photocurable resin composition. . Further, the total content of the components (A-1) and (A-2) is determined based on the total stability of the photocurable resin composition from the viewpoint of improving stability in a reliability test and improving curability in a light-shielding portion. It is preferably 99% by mass or less, more preferably 97% by mass or less, even more preferably 95% by mass or less based on the mass.

  As the component (B), a known photopolymerization initiator can be used. The photopolymerization initiator can be appropriately selected according to the extinction coefficient for the irradiation light. For example, commercially available photopolymerization initiators having an extinction coefficient (mL / g · cm in MEOH) shown in the following table (Omnirad series and Omnicat series manufactured by IGM Resins, Irgacure series manufactured by BASF, CPI manufactured by San Apro) Series) can be used.

  The photocurable resin composition of the present embodiment has, as a component (B), (B-1) a first sensitivity having a sensitivity to light having a wavelength of Xnm and a sensitivity having a sensitivity to light having a wavelength of Ynm that is shorter than the wavelength Xnm. A photopolymerization initiator, (B-2) having substantially no sensitivity to light of wavelength Xnm or having an extinction coefficient of 1/4 or less of the first photopolymerization initiator, And a second photopolymerization initiator having sensitivity to light. As the component (B-1) and the component (B-2), one type can be used alone, or two or more types can be used in combination.

  Examples of the values of Xnm and Ynm include combinations of (I) 405 nm and 365 nm, (II) 405 nm and 313 nm, and (III) 365 nm and 313 nm.

  In the case of the component (B-1) and the component (B-2), the first photopolymerization initiator has an absorption coefficient at a wavelength of 405 nm of 7 mL / g · cm or more and a wavelength of 365 nm. The extinction coefficient is at least 38 mL / g · cm, and the second photopolymerization initiator has an extinction coefficient at a wavelength of 405 nm of at most 5 mL / g · cm and an extinction coefficient at a wavelength of 365 nm of at least 38 mL / g · cm. Can be used.

  In this case, as the first photopolymerization initiator, Omnirad 127, 369, 369E, 379, 379EG, 819, TPOG, and 784, and Irgacure OXE01 can be used, and as the second photopolymerization initiator, For example, Omnirad 651, 184, 1173, 500, 2959, 754, MBF, and 907, Irgacure OXE02, CPI-210S, and CPI-300 can be used.

  In the case of (II), the first photopolymerization initiator has an absorption coefficient at a wavelength of 405 nm of 7 mL / g · cm or more, and an absorption coefficient at a wavelength of 313 nm of 150 mL / g · cm or more. As the photopolymerization initiator, those having an absorption coefficient at a wavelength of 405 nm of 5 mL / g · cm or less and an absorption coefficient at a wavelength of 313 nm of 150 mL / g · cm or more can be used.

  In this case, Omnirad 127, 369, 369E, 379, 379EG, 819, TPO G, 784, Irgacure OXE01, CPI-400 can be used as the first photopolymerization initiator, and the second photopolymerization initiator can be used. For example, Omnirad 651, 184, 1173, 500, 2959, 754, MBF, 907, Irgacure OXE02, Omnicat 250, CPI-210S, and CPI-300 can be used.

  In the case of (III), the first photopolymerization initiator has an absorption coefficient at a wavelength of 365 nm of 60 mL / g · cm or more, and an absorption coefficient of a wavelength of 313 nm of 150 mL / g · cm or more. The photopolymerization initiator has an extinction coefficient at a wavelength of 365 nm of 60 mL / g · cm or less and １ ／ or less of the first photopolymerization initiator, and an extinction coefficient of a wavelength of 313 nm of 150 mL / g · cm or more. Some can be used.

  In this case, as the first photopolymerization initiator, Omnirad 651, 184, 1173, 500, 127, 907, 369, 369E, 379, 379EG, 819, TPOG, Irgacure OXE01, OXE02, CPI-210S, CPI- 300 and CPI-400 can be used, and as the second photopolymerization initiator, Omnirad 2959, 754, MBF, Omnicat 250, acetophenone, and benzophenone can be used.

  The total content of the component (B) is 0.5 parts by mass with respect to 100 parts by mass of the component (A) in view of reducing the influence of oxygen inhibition and promoting the curing of the surface of the cured resin. It is preferably at least 2 parts by mass, more preferably at least 4 parts by mass. The content of the component (B) is 15 parts by mass with respect to 100 parts by mass of the component (A) in total from the viewpoint of improving the toughness of the photocurable resin composition after curing and preventing bleeding of low molecules. Is preferably not more than 10 parts by mass, more preferably not more than 7 parts by mass.

From the viewpoint of increasing the elasticity or hardness of the surface and easily reducing the elasticity or hardness of the deep part, the content I ₁ of the _first photopolymerization initiator in the photocurable resin composition and the second photopolymerization start The mass ratio I ₁ / I ₂ to the content I _{2 of the} agent is preferably 10 to 1/1000, more preferably 1 to 1/100, and 1/10 to 1/30. More preferred.

  As for the content of the component (B-1) and the component (B-2) in the photocurable resin composition, the elastic modulus or the hardness at the surface and the deep portion of the light-irradiated body made of the photocurable resin composition is preferably in a range. Can be set appropriately so that

  In this specification, the elastic modulus is measured by a method based on the test standard JIS K 7244 (ISO 6721), and the hardness is measured by a method based on JIS K 6253.

  Regarding the hardness of the surface, a resin having a thickness of 500 μm obtained by peeling the release PET after curing the resin at a wavelength of Ynm with a resin composition and a spacer of 500 μm sandwiched between the release surfaces of the two release PETs. An 80 mm × 80 mm × 7 mm block obtained by laminating a cured product of the composition can be used for measurement. For the hardness of the deep part, the resin composition was poured into a dam of 80 mm x 80 mm x 7 mm formed on a glass plate, cured at a wavelength of X nm, and then a block of 80 mm x 80 mm x 7 mm obtained by removing the dam was measured. Can be used. Alternatively, the measuring method in the example described later may be adopted.

  Examples of the component (C) include a cyanoacrylate-based, dihydroxybenzophenone-based, benzotriazole-based, triazine-based, benzophenone-based, and benzoate-based ultraviolet absorber. These UV absorbers include Adekastab LA-32, Adekastab LA-38, Adekastab LA-36, Adekastab LA-34, Adekastab LA-31, Adekastab 1413, Adekastab LA-51, Adekastab LA-46, Adekastab LA-F70 ( Abineul 400, Uvinul M-40, Uvinul MS-40, Uvinul N-35, Uvinul N-539, Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 460 And commercially available ultraviolet absorbers such as Tinuvin 479 and Tinuvin 1577 (product names, manufactured by BASF). By blending the ultraviolet absorber, the depth of the high elasticity portion or the high hardness portion can be adjusted. For example, when the blending amount of the ultraviolet absorber is increased, light hardly reaches a deep portion, and a high elasticity portion or a high hardness portion can be made shallower. From such a viewpoint, the component (C) has an absorption coefficient at a wavelength Xnm of 5 ml / g · cm or less and has substantially no absorption capacity, and an absorption coefficient at a wavelength Ynm of 38 ml / g · cm or more. Is desirable.

  As the component (D), for example, a commercially available antioxidant such as IRGANOX1010, IRGANOX1035, or IRGANOX1520 (product name, manufactured by BASF) can be used. By blending the antioxidant, it is possible to suppress the unreacted component (A) remaining in the deep part from being cured by heat and increasing the elastic modulus or hardness.

  As the component (E), for example, a known chain transfer agent such as a thiol compound can be used. By blending the curing accelerator, it is possible to promote curing of a deep part where light does not easily reach, for example, when the gap between the housing and the image display unit is narrow.

  Examples of the thiol compound include TMMP, TEMPIC, PEMP, EGMP-4, DPMP (product name, manufactured by SC Organic Chemical Co., Ltd.), Karenz MT-PE1, Karenz MT-BD1, Karenz MT-NR1 (above, manufactured by Showa Denko) , And product names) can be used.

  As the component (F), for example, acrylic oligomer, urethane oligomer, polyester oligomer, polyether oligomer, (hydrogenated) polyisoprene, hydroxyl group-containing (hydrogenated) polyisoprene, (hydrogenated) polybutadiene, and hydroxyl group-containing (hydrogenated) It is possible to use a known plasticizer such as a rubber polymer such as polybutadiene and polybutene, a phthalate ester, a polyvalent carboxylate ester, an alkyl benzoate, a phosphate ester, a trimellitate ester, a terpene resin and a rosin ester resin. it can.

  The photocurable resin composition of the present embodiment may contain various additives as necessary. As additives, for example, adhesion improvers such as coupling agents, polymerization inhibitors, light stabilizers, defoamers, fillers, chain transfer agents, thixotropic agents, flame retardants, release agents, surfactants, lubricants And an antistatic agent. Known additives can be used as these additives.

  From the viewpoint of filling properties, the photocurable resin composition of the present embodiment preferably has a viscosity at the time of filling of 4 to 20 Pa · s. With such a viscosity, it is easy to fill the gap by capillary action. The photocurable resin composition of the present embodiment may have a viscosity at 25 ° C. of 4 to 20 Pa · s. The viscosity of the photocurable resin composition can be measured using a single cylindrical rotational viscometer (B-type viscometer). As a single cylindrical rotational viscometer, "TVB-10 type viscometer" manufactured by Toki Sangyo Co., Ltd. can be mentioned.

  The viscosity of the photocurable resin composition can be adjusted, for example, by changing the content of each component. When it is desired to increase the viscosity, the content of the component (A-1) may be reduced and the content of the component (A-2) may be increased. On the other hand, when it is desired to lower the viscosity, the content of the component (A-2) may be reduced and the content of the component (A-1) may be increased.

The photocurable resin composition of the present embodiment preferably satisfies the following conditions.
(A) When the conversion of the component (A) is 90 to 100%, the hardness is Shore D30 to D90.
(B) When the conversion of the component (A) is 80% or more and less than 90%, the hardness is Shore A20 to D30.
(C) When the conversion of the component (A) is less than 80%, the hardness is not more than Shore A20.
In addition, the reaction rate was determined based on the absorption peak height (X) of 820 to 800 cm ⁻¹ from the baseline in the FR-IR measurement chart of the resin composition layer before ultraviolet irradiation, and the FR of the resin composition layer after ultraviolet irradiation. It can be calculated by substituting the absorption peak height (Y) at 820 to 800 cm ^-1 from the baseline in the IR measurement chart into the following equation (1).
Reaction rate (%) = {(XY) / X} × 100
UV and dose irradiation is, 8000 MW / cm ² at 405nm of LED, or ^{160000mJ / cm 2, 5000mW / cm} 2 at 365nm of LED, or ^{100000mJ / cm 2, 300mW / cm} 2 in a metal halide lamp, or 6000 mJ / cm ^Let it be ² .
The condition (a) can correspond to the hardness at the surface of the cured product, and the condition (c) can correspond to the hardness at the deep portion of the cured product.

  The above physical properties can be adjusted by, for example, the components (A), (B), (C), (D), (E) and (F).

  According to the photocurable resin composition of the present embodiment, it is possible to easily form a cured resin containing portions having different elastic modulus or hardness, for example, by specific light irradiation, a high elasticity is applied to the light irradiation surface side. It becomes easy to form a resin cured product having a low elasticity portion or a low hardness portion on the deep portion side or the high hardness portion.

  The photocurable resin composition of the present embodiment can be used, for example, to form a sealing portion that seals between a housing and an image display unit in an image display device described later. Other uses of the photocurable resin composition of the present embodiment can be used to form a shock absorbing material, a sealing material, and a coating material.

<Method of forming cured resin>
The method for forming a cured resin according to the present embodiment includes a first exposure step of irradiating a light-irradiated body made of the photocurable resin composition according to the present embodiment with a first light; And a second exposure step of irradiating the photocurable resin composition irradiated with the second light.

In the present embodiment, the following steps may be provided instead of the first exposure step and the second exposure step.
(I) Third exposure step of irradiating the light-irradiated body made of the photocurable resin composition according to the present embodiment with third light (ii) Photocurable resin composition according to the present embodiment Exposure step of irradiating a light-irradiated body comprising a first light and a second light

  When the light-irradiated body is made of the photocurable resin composition containing the component (B-1) and the component (B-2) of the above (I), the first light contains light having a wavelength of 405 nm and The second light includes light with a wavelength of 365 nm, or the first light includes light with a wavelength of 365 nm and the second light includes light with a wavelength of 405 nm, or the third light includes light and a wavelength of 405 nm. 365 nm light can be included.

  When the light-irradiated body is made of a photocurable resin composition containing the component (B-1) and the component (B-2) of the above (II), the first light contains light having a wavelength of 405 nm, and The second light includes light with a wavelength of 365 nm, or the first light includes light with a wavelength of 405 nm and the second light includes light with a wavelength of 313 nm, or the third light includes light and a wavelength of 405 nm. 313 nm light can be included.

  When the light-irradiated body is made of the photocurable resin composition containing the component (B-1) and the component (B-2) of the above (III), the first light contains light having a wavelength of 365 nm, and The second light includes light having a wavelength of 313 nm, or the first light includes light having a wavelength of 313 nm and the second light includes light having a wavelength of 365 nm, or the third light includes light and a wavelength of 365 nm. 313 nm light can be included.

  According to the method for forming a cured resin of the present embodiment, it is possible to increase the elastic modulus or hardness of the cured resin and lower the elastic modulus or hardness. In other words, long-wavelength exposure easily obtains sufficient illuminance from the surface to the deep part of the resin, short-wavelength exposure does not easily reach the deep part of the resin, and sufficient illuminance is easily obtained only on the surface side. On the surface side of the irradiation body, both the first photopolymerization initiator and the second photopolymerization initiator are consumed by the first exposure step, the second exposure step, or the fourth exposure step. The reaction rate of the photopolymerizable compound is increased, and a higher elastic modulus or a higher hardness can be achieved, and the deep side of the filled photocurable resin composition is subjected to the first exposure step and the second exposure step. Or even by the fourth exposure step, the first photopolymerization initiator is not consumed or is hardly consumed, and the reaction rate of the photopolymerizable compound can be suppressed by consuming the second photopolymerization initiator, Low elastic modulus or low hardness can be achieved.

  In the third exposure step, the same effect as described above can be obtained by including the long wavelength light and the short wavelength light in the third light.

  The light source used for light irradiation is not particularly limited, and examples thereof include an LED lamp, a mercury lamp (low pressure, high pressure, ultra high pressure, etc.), a metal halide lamp, an excimer lamp, a xenon lamp, and the like. Lamps, metal halide lamps and the like.

  The exposure amount can be appropriately adjusted so that a predetermined reaction rate is obtained in the light-irradiated body.

  The light-irradiated body can be appropriately provided by a known method depending on a place where the cured resin is formed. For example, when a light-irradiated body is provided on the surface of a substrate, the photocurable resin composition of the present embodiment may be formed by stencil printing, dispenser, screen printing, transfer printing, offset printing, jet printing, a jet dispenser, and a needle dispenser. , Comma coater, slit coater, die coater, gravure coater, slit coat, letterpress printing, intaglio printing, gravure printing, soft lithography, bar coat, applicator, particle deposition method, spray coater, spin coater, dip coater, electrodeposition coating etc. Can be applied to the surface of the substrate and dried. When the light-irradiated body is provided in the gap between the members, the photocurable resin composition of the present embodiment may be directly filled with an air-type dispenser, a mechanical dispenser, a jet dispenser, or the like, using a capillary phenomenon. The space between the members can be filled by the filling means.

  Next, an example in which the cured resin according to the present embodiment is formed as a sealing material will be described.

The method for forming a cured resin according to the present embodiment includes a housing, an image display unit housed in the housing, and a sealing unit that seals at least a part between the housing and the image display unit. This is a method for forming a resin cured product as a sealing portion in an image display device provided with the method, and includes the following steps.
(S1) A filling step of filling the photocurable resin composition between the image display unit housed in the casing and the casing (S2) Irradiating the filled photocurable resin composition with the first light. First exposure step (S3) of exposing the photocurable resin composition irradiated with the first light to the second exposure step

  FIG. 1 is a diagram for explaining a method for forming a cured resin according to the present embodiment. FIGS. 1A and 1B show the above step (S1), in which a photo-curable resin composition 50 is filled between the image display unit 10 and the housing 20 housed in the housing 20. Filled with 60. The image display unit 10 includes a liquid crystal module 1, a cover glass 3, and an OCA 2 that adheres them, and is fixed to the housing 20 by a pressure-sensitive adhesive layer 30.

  FIGS. 1C and 1D show the above steps (S2) and (S3), respectively. In the step (S2), the first light L1 is irradiated on the light-irradiated body 50 made of the filled photocurable resin composition. In the step (S3), the light-irradiated body irradiated with the first light is irradiated. 50 is irradiated with the second light L2.

The method for forming a cured resin product of the present embodiment may include the following steps instead of the steps (S2) and (S3).
(S4) Third exposure step of irradiating the light-irradiated body with third light (S5) Fourth exposure step of irradiating the light-irradiated body with first light and second light

  FIG. 2 is a schematic cross-sectional view showing an image display device provided with a cured resin formed by the method for forming a cured resin of the present embodiment. After the above steps, as shown in FIG. 2, a high elasticity portion (or high hardness portion) 72 and a low elasticity portion (or low hardness portion) 74 are provided between the image display unit 10 and the housing 20. The sealing portion 80 can be formed from a cured resin. The image display device 100 shown in FIG. 2 can include a sealing portion 80 formed of a cured resin having waterproofness and shock absorption.

(Step (S1))
The filling of the photocurable resin composition can be performed by the filling method described above.

(Steps (S2), (S3), (S4), (S5))
The light source used for light irradiation is not particularly limited, and the above light sources can be used.

  When the light-irradiated body is made of the photocurable resin composition containing the components (B-1) and (B-2) of the above (I), the light source of the first light and the second light is 405 nm. LED lamp and a 365 nm LED lamp can be used.

  When the light-irradiated body is made of the photocurable resin composition containing the component (B-1) and the component (B-2) of the above (II), the light source of the first light and the second light is 405 nm. LED lamps and metal halides can be used. In step S4, a metal halide can be used as the third light source.

  When the light-irradiated body is made of the photocurable resin composition containing the component (B-1) and the component (B-2) of the above (III), 365 nm is used as a light source of the first light and the second light. LED lamps and metal halides can be used.

  The exposure amount can be appropriately adjusted so that a predetermined reaction rate is obtained in the light-irradiated body.

  For example, the reaction rate of the component (A) on the surface of the light irradiation object (for example, 0.5 mm from the surface to be exposed) becomes 90% or more, and the reaction rate of the deep part of the light irradiation object (for example, 0. The exposure amount can be adjusted so that the reaction rate of the component (A) at 5 mm to 2.0 mm) is less than 90%. At this time, the difference between the reaction rate S and the reaction rate D may be 10% or more, or may be 20% or more.

  The method for forming a cured resin according to the present embodiment can be applied to the manufacture of image display devices such as mobile terminals, in-vehicle terminals, and medium / large displays. Examples of the mobile terminal include a mobile phone, a smart phone, a personal computer, an electronic dictionary, a calculator, a game machine, and the like.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

The following materials were used in Examples and Comparative Examples.
(A) Component UN-6060S: Negami Kogyo Co., Ltd., product name "Art Resin UN-6060S", urethane acrylate compound FA-314A: Hitachi Chemical Co., Ltd., product name "FA-314A", nonylphenoxy polyethylene glycol Acrylate IBOA: Isobornyl acrylate (manufactured by Nippon Shokubai Co., Ltd.)
TE-2000: manufactured by Nippon Soda Co., Ltd., product name "TE-2000", terminal acrylic-modified polybutadiene TAIC: manufactured by Mitsubishi Chemical Corporation, product name "TAIC", triallyl isocyanurate CEL2021P: manufactured by Daicel, product name " Celloxide 2021P ", 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexenylcarboxylate EHA: ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.)
4-HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Company)
TEGDVE: Triethylene glycol divinyl ether (manufactured by Nippon Carbide Industry Co., Ltd.)

(B) Component Omnirad 819: manufactured by IGM Resins, product name “Omnirad 819”, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide Omnirad TPO G: manufactured by IGM Resins, product name “Omnirad TPO G” 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide Omnirad 184: manufactured by IGM Resins, product name "Omnirad 184", 1-hydroxy-cyclohexyl-phenyl-ketone Omnicat 250: manufactured by IGM Resins, product name "Omnicat 250", iodonium salt-based acid generator CPI-210S: manufactured by San Apro Co., product name "CPI-210S", triarylsulfonium salt-based photoacid generator

(E) Component Karenz MT-PE1: manufactured by Showa Denko, product name “Karenz MT-PE1”, pentaerythritol tetrakis (3-mercaptobutyrate)

(F) Component acrylic oligomer: An acrylic polymer synthesized by the following procedure was used.
First, 108.0 g of 2-ethylhexyl acrylate (AA monomer) and 2-hydroxyethyl acrylate (HA monomer) as initial monomers in a reaction vessel equipped with a cooling pipe, a thermometer, a stirrer, a dropping funnel, and a nitrogen injection pipe. 0 g and 150.0 g of methyl isobutyl ketone were mixed and heated to room temperature (25 ° C.) to 70 ° C. for 15 minutes while replacing with nitrogen at an air flow rate of 100 ml / min to obtain a solution A. Thereafter, 27.0 g of 2-ethylhexyl acrylate and 3.0 g of 2-hydroxyethyl acrylate were mixed as an additional monomer to obtain a mixed solution, and a solution B in which 0.6 g of lauroyl peroxide was dissolved in the mixed solution was prepared. Solution B was added dropwise to solution A maintained at 70 ° C. over 60 minutes, and after the addition was completed, the reaction was further performed for 2 hours. Subsequently, methyl isobutyl ketone was distilled off to obtain a copolymer of 2-ethylhexyl acrylate (AA monomer) and 2-hydroxyethyl acrylate (HA monomer) (weight average molecular weight: 250,000).

[Preparation of photocurable resin composition]
(Example 1)
"UN-6060S" (manufactured by Negami Kogyo Co., Ltd., product name, urethane acrylate compound) 60 parts by mass, nonylphenoxy polyethylene glycol acrylate "FA-314A" (manufactured by Hitachi Chemical Co., Ltd., product name "FA-314A") 15 Parts by mass, 15 parts by mass of isobornyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by IGM Resins, product name "Omnirad TPO") as a component (B-1) G ") 0.03 parts by mass and 1-hydroxy-cyclohexyl-phenyl-ketone" Omnirad 184 "(manufactured by IGM Resins, product name" Omnirad 184 ") as the component (B-2) were heated at 70C. While stirring for 30 minutes, a photocurable resin composition was obtained.

(Examples 2 to 4, and Comparative Examples 1 and 2)
Photocurable resin compositions were obtained in the same manner as in Example 1 except that the composition (unit: parts by mass) shown in Table 2 was changed.

[Evaluation of cured product of photocurable resin composition]
(surface hardness)
Regarding the surface hardness, a resin composition and a 500 μm spacer were sandwiched between two release PETs whose release surfaces were opposed to each other, and cured with a light source (wavelength Xnm) and an exposure amount shown in Table 2; After curing with a light source (wavelength Ynm) and an exposure amount shown in Table 2, the release PET was peeled off to prepare a cured product of a resin composition having a thickness of 500 µm. The cured product was laminated to obtain a block of 80 mm × 80 mm × 7 mm.

  The hardness of the above block was measured by a method based on JIS K6253.

(Deep hardness)
The hardness at the deep part was measured by the following procedure. First, a resin composition and a 3.5-mm spacer are sandwiched between two release PETs whose release surfaces are opposed to each other, and cured by a light source (wavelength X nm) and an exposure amount shown in Table 2 to form a film having a thickness of 3 mm. A film of a resin composition of 0.5 mm was produced. Next, a resin composition and a 500 μm spacer are sandwiched between two release PETs with the release surfaces facing each other, and cured with a light source (wavelength Xnm) and an exposure amount shown in Table 2 to obtain a film thickness of 500 μm. A film of the resin composition was prepared, a film of the resin composition having a thickness of 3.5 mm prepared above was laminated thereon, and a light source (wavelength Ynm) and an exposure amount shown in Table 2 from the 500 μm film side. After curing, the release PET was peeled off to prepare a cured product of the resin composition having a thickness of 3.5 μm. The cured product was laminated to obtain a block of 80 mm × 80 mm × 7 mm.

  The hardness of the above block was measured by a method based on JIS K6253.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal module, 2 ... OCA, 3 ... Cover glass, 10 ... Image display part, 20 ... Housing, 30 ... Pressure sensitive adhesive layer, 50 ... Photocurable resin composition, 60 ... Filling nozzle, 72 ... High elasticity Part (or high hardness part), 74: low elasticity part (or low hardness part), 80: sealing part (cured resin), 100: image display device.

Claims (12)

(A) a photopolymerizable compound, (B-1) a first photopolymerization initiator, and (B-2) a second photopolymerization initiator.
The first photopolymerization initiator has an extinction coefficient at a wavelength of 405 nm of 7 mL / g · cm or more, and an extinction coefficient of 365 nm at a wavelength of 38 mL / g · cm or more,
The photocurable resin composition, wherein the second photopolymerization initiator has an absorption coefficient at a wavelength of 405 nm of 5 mL / g · cm or less and an absorption coefficient of 365 nm at a wavelength of 38 mL / g · cm or more. (A) a photopolymerizable compound, (B-1) a first photopolymerization initiator, and (B-2) a second photopolymerization initiator.
The first photopolymerization initiator has an absorption coefficient at a wavelength of 405 nm of 7 mL / g · cm or more, and an absorption coefficient at a wavelength of 313 nm of 150 mL / g · cm or more,
The photocurable resin composition, wherein the second photopolymerization initiator has an extinction coefficient at a wavelength of 405 nm of 5 mL / g · cm or less and an extinction coefficient at a wavelength of 313 nm of 150 mL / g · cm or more. (A) a photopolymerizable compound, (B-1) a first photopolymerization initiator, and (B-2) a second photopolymerization initiator.
The first photopolymerization initiator has an absorption coefficient at a wavelength of 365 nm of 60 mL / g · cm or more, and an absorption coefficient of a wavelength of 313 nm of 150 mL / g · cm or more,
The second photopolymerization initiator has an extinction coefficient at a wavelength of 365 nm of 60 mL / g · cm or less, is １ ／ or less of the first photopolymerization initiator, and has an extinction coefficient of 313 nm at a wavelength of 150 mL. / G · cm or more, a photocurable resin composition. The mass ratio of the content of _{I 2} of the photocurable content of the first photoinitiator in the resin composition _{I 1} and the second photoinitiator _I 1 / _{I 2} is 10-1 / 1000 The photocurable resin composition according to any one of claims 1 to 3, wherein   The photocurable resin composition according to any one of claims 1 to 4, further comprising (C) an ultraviolet absorber. The photocurable resin composition according to any one of claims 1 to 5, which satisfies all of the following conditions (a), (b), and (c).
(A) When the conversion of the component (A) is 90 to 100%, the hardness is Shore D30 to D90.
(B) When the conversion of the component (A) is 80% or more and less than 90%, the hardness is Shore A20 to D30.
(C) When the conversion of the component (A) is less than 80%, the hardness is not more than Shore A20. A first exposure step of irradiating a light irradiation object comprising the photocurable resin composition according to claim 1 with a first light,
A second exposure step of irradiating the photocurable resin composition irradiated with the first light with a second light,
The first light includes light having a wavelength of 405 nm and the second light includes light having a wavelength of 365 nm, or the first light includes light having a wavelength of 365 nm and the second light has a wavelength of 405 nm. A method for forming a cured resin, including light. A first exposure step of irradiating a light irradiation object comprising the photocurable resin composition according to claim 2 with a first light,
A second exposure step of irradiating the photocurable resin composition irradiated with the first light with a second light,
The first light includes light having a wavelength of 405 nm and the second light includes light having a wavelength of 313 nm, or the first light includes light having a wavelength of 313 nm and the second light includes light having a wavelength of 405 nm. A method for forming a cured resin, including light. A first exposure step of irradiating a light irradiation object comprising the photocurable resin composition according to claim 3 with a first light;
A second exposure step of irradiating the photocurable resin composition irradiated with the first light with a second light,
The first light includes light having a wavelength of 365 nm and the second light includes light having a wavelength of 313 nm, or the first light includes light having a wavelength of 313 nm and the second light includes light having a wavelength of 365 nm. A method for forming a cured resin, including light. An exposure step of irradiating a light-irradiated body comprising the photocurable resin composition according to claim 1 with light,
A method for forming a cured resin, wherein the light includes light having a wavelength of 405 nm and light having a wavelength of 365 nm. An exposure step of irradiating a light-irradiated body comprising the photocurable resin composition according to claim 2 with light,
A method for forming a cured resin, wherein the light includes light having a wavelength of 405 nm and light having a wavelength of 313 nm. An exposure step of irradiating a light-irradiated body comprising the photocurable resin composition according to claim 3 with light,
A method for forming a cured resin, wherein the light includes light having a wavelength of 365 nm and light having a wavelength of 313 nm.

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