JP2007025091A - Method for forming optical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming an optical waveguide which includes a core having various shapes such as a branch by only a simple step of irradiation with light or the like while eliminating a step of patterning a core by development. <P>SOLUTION: The method includes: (a) a step of applying a photosensitive composition 3 containing (A) a radial polymerizable compound, (B) a photo-radical polymerization initiator, and (C) a cation polymerizable compound is applid on substrates 1, 2; (b) a step of irradiating a region where a core is to be formed through upper surface of the applied photosensitive composition 3 with light at 405 nm wavelength as the photosensitive wavelength of the component (B) in the presence of oxygen by 1 vol%, and curing the component (A) to form a core 6; and (c) a step of irradiating the whole area with light 7 at 365 nm as the photosensitive wavelength of the component (C) to form a clad 8 around and above the core 6, the clad 8 having a refractive index lower than that of the core. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cured product for light transmission comprising a photosensitive composition, and protection of the cured product having a refractive index smaller than that of the cured product formed around and / or on the cured product. The present invention relates to a method for forming an optical member (for example, an optical waveguide, a microlens array, etc.) including a cured product (hereinafter referred to as a coated cured product).

The optical waveguide is an optical component for connecting optical fibers or the like, and is composed of a core portion that is a portion through which light is transmitted and a cladding portion that is formed around the core portion. The clad portion protects the core portion and has a refractive index smaller than that of the core portion, thereby preventing leakage of light from the core portion.
Conventionally, a method for manufacturing an optical transmission line (optical waveguide) including a core part and a clad part using a curable solution obtained by mixing two kinds of resin solutions has been proposed (Patent Document 1).
In this method, the first photocurable resin solution is mixed with the first photocurable resin solution and the second photocurable resin solution having a curing start wavelength shorter than that of the first photocurable resin solution. The first and second photocurable resins are applied to the mixed solution remaining on the outer periphery of the core portion after a light beam is incident in a wavelength band for curing only the resin solution to produce an axial core portion. Light is irradiated in a wavelength band for curing the solution to produce a clad portion around the core portion, and an optical transmission line in which the refractive index of the core portion is larger than the refractive index of the clad portion is completed.
JP 2000-347043 A

According to the technique described in the above-mentioned document, the linear core part and the cladding part around the core part can be formed only by light irradiation without including the patterning process of the core part by development. it can.
However, with this technique, core portions having various shapes such as a branched shape cannot be formed. Further, it cannot be applied to a method for forming another optical member such as a microlens array.
Therefore, the present invention can form an optical waveguide including a core portion having various shapes such as a branched shape only by a simple process such as light irradiation without including a patterning step of the core portion by development. A further object of the present invention is to provide a method for forming an optical member that can be applied to the formation of optical members other than the optical waveguide (for example, a microlens array).

  As a result of intensive studies to solve the above problems, the present inventor has found that a predetermined photocurable component for forming a cured body (for example, a core portion, a microlens, etc.), the periphery of the cured body, and / or Alternatively, a photosensitive composition containing a predetermined photocurable or thermosetting component for forming a coated cured body (for example, a clad or a microlens protective layer) on the cured body is formed on a substrate (for example, , Lower clad, solid-state imaging device, etc.) on the upper surface of the thin film-like photosensitive composition, light having a predetermined wavelength (for example, 400 to 800 nm) is applied to the upper surface of the thin-film photosensitive composition in a predetermined atmosphere. Then, if irradiation is performed using a mask having a predetermined pattern shape, a cured body having a predetermined shape (for example, a branched core, a plurality of microlenses, etc.) can be obtained, and the cured body After obtaining the cured body and If the photosensitive composition as a whole including the uncured portion is irradiated with light having a predetermined wavelength (for example, less than 400 nm) or heated, the coating is cured around and / or on the cured body. The present invention was completed by finding that a body was formed.

That is, the present invention provides the following [1] to [6].
[1] To form an optical member comprising a cured body and a coated cured body having a refractive index smaller than that of the cured body formed on and / or around the cured body on the substrate. The photosensitive composition containing (a) (A) a radical polymerizable compound, (B) a photo radical polymerization initiator, and (C) a cationic polymerizable compound is applied onto the substrate. And (b) from the upper surface of the applied photosensitive composition, in the presence of 1% by volume or more of oxygen to the region where the cured body is formed, Irradiating light containing a photosensitive wavelength, and (A) forming the cured product by curing the radical polymerizable compound; and (c) heating at a temperature capable of curing the (C) cationic polymerizable compound. The coating around the cured body and / or on the cured body And a step of forming a cured body.
[2] To form an optical member comprising a cured body and a coated cured body around the cured body and / or on the cured body and having a refractive index smaller than that of the cured body on the substrate. A photosensitive composition comprising (a) (A) a radical polymerizable compound, (B) a photo radical polymerization initiator, (C) a cationic polymerizable compound, and (D) a photo cationic polymerization initiator. And (b) from the upper surface of the coated photosensitive composition, in the presence of 1% by volume or more of oxygen relative to the region where the cured body is formed. (B) irradiating light including the photosensitive wavelength of the photo radical polymerization initiator to form the cured product by curing the radical polymerizable compound (A), and (c) starting the photo cationic polymerization (C). Irradiate light containing the photosensitive wavelength of the agent, and around the cured body and And / or the step of forming the coated cured body on the cured body, and the (B) radical photopolymerization initiator has a photosensitive wavelength of 400 nm to 800 nm and the above (B) of 400 nm to 800 nm. There is a wavelength (λ1) where the photoradical polymerization initiator is sensitive but the (D) photocationic polymerization initiator is not sensitive, and the wavelength of the light irradiated in the step (b) is the wavelength (λ1). There is provided a method for forming an optical member.
[3] The method for forming an optical member according to [1] or [2], wherein the (A) radical polymerizable compound is a compound having an acryloyl group.
[4] The method for forming an optical member according to the above [1] or [2], wherein the (C) cationically polymerizable compound is a compound having a cyclic ether structure.
[5] The method for forming an optical member according to any one of [1] to [4], wherein the optical member is an optical waveguide.
[6] The method for forming an optical member according to any one of [1] to [4], wherein the optical member is a microlens array.

  According to the method for forming an optical member of the present invention, an optical waveguide including a core portion having various shapes such as a branched shape, without including a patterning step of the core portion by development, only by a simple step such as light irradiation. Alternatively, an optical member such as a microlens array used for the light receiving portion of the solid-state imaging device can be formed.

Hereinafter, the present invention will be described separately for the case where the coated cured body is formed by heating and the case where the coated cured body is formed by light irradiation.
[A. When forming a coated cured body by heating]
The method for forming an optical member of the present invention comprises: a cured body on a substrate; and a coated cured body having a refractive index smaller than that of the cured body, which is formed around and / or on the cured body. A photosensitive composition containing (a) (A) a radical polymerizable compound, (B) a photo radical polymerization initiator, and (C) a cationic polymerizable compound. A step of coating on the substrate; and (b) from the upper surface of the coated photosensitive composition, in the presence of 1% by volume or more of oxygen (photo radical polymerization) from the region where the cured body is formed. (B) in the presence of a gas to be inhibited) irradiating light containing the photosensitive wavelength of the (B) photoradical polymerization initiator, and (A) forming the cured product by curing the radically polymerizable compound; c) The above (C) cationic polymerizable compound can be cured. Performing heat in degrees, it is intended to include a step of forming the coating cured product on the periphery and / or cured embodying the cured product.
In the present invention, when the base is the substrate of the optical waveguide and the lower clad, the optical member includes a core part (cured body) formed on the lower clad, and an upper part formed on and around the core part. Includes clad (hardened coating).
In the present invention, when the substrate is an optical device such as a solid-state imaging device, the optical member protects the plurality of microlenses (cured bodies) formed on the solid-state imaging device and the plurality of microlenses. Protective layer (coating cured body).

[Step (a)]
Step (a) is a step of applying a photosensitive composition containing (A) a radical polymerizable compound, (B) a photo radical polymerization initiator, and (C) a cationic polymerizable compound on the substrate. .
(A) Radical polymerizable compound The radical polymerizable compound is preferably a (meth) acrylate compound having a high curing rate.
More specifically, the radical polymerizable compound contains one or both of a compound having a structure represented by the following formula (1) and a compound having a structure represented by the following formula (2). Is preferable from the viewpoint of high refractive index, waveguide loss, and adhesion to a substrate.
From the viewpoint of improving heat resistance, di (meth) acrylate having a structure represented by the formula (1) is particularly preferable.

（式中、Ｒ^１は−（ＣＨ_２ＣＨ_２Ｏ）_ｍ−、−（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｍ−、または−ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ−；Ｘは−Ｃ（ＣＨ_３）_２−、−ＣＨ_２−、−Ｏ−または−ＳＯ_２−；Ｙは水素原子またはハロゲン原子；ｍは０〜４の整数を表す。）

（式中、Ｒ^２は−（ＣＨ_２ＣＨ_２Ｏ）_ｎ−、−（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｎ−、または−ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ−；Ｙは水素原子またはハロゲン原子、Ｐｈ−Ｃ（ＣＨ_３）_２−、Ｐｈ−、または炭素数１〜２０のアルキル基；ｎは０〜４の整数を表す。ただし、Ｐｈはフェニル基を表す。）

(Wherein R ¹ represents — (CH ₂ CH ₂ O) _m —, — (CH ₂ CH (CH ₃ ) O) _m —, or —CH ₂ CH (OH) CH ₂ O—; X represents —C ( CH ₃ ) ₂ —, —CH ₂ —, —O— or —SO ₂ —; Y represents a hydrogen atom or a halogen atom; m represents an integer of 0 to 4.

(Wherein R ² represents — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; Y represents a hydrogen atom or A halogen atom, Ph—C (CH ₃ ) ₂ —, Ph—, or an alkyl group having 1 to 20 carbon atoms; n represents an integer of 0 to 4, provided that Ph represents a phenyl group.

Specific examples of the radically polymerizable compound include a polyfunctional monomer having two or more ethylenically unsaturated bond groups in one molecule and a monofunctional compound having one ethylenically unsaturated bond group in one molecule. Monomer. These monofunctional monomers and polyfunctional monomers may be used in combination.
Examples of the multifunctional monomer include ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, and tricyclodecanediyldimethylene di (meth) acrylate. , Tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, caprolactone-modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, trimethylol Propane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, tripropylene group Cold di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (Meth) acrylate, polyester di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, caprolactone modified di Pentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tetra ( (B) Specific examples of di (meth) acrylates having a structure represented by formula (1) in addition to (meth) acrylates of acrylate, phenol novolac polyglycidyl ether, etc., for example, ethylene oxide-added bisphenol A (meth) acrylic acid Esters, ethylene oxide-added tetrabromobisphenol A (meth) acrylate, propylene oxide-added bisphenol A (meth) acrylate, propylene oxide-added tetrabromobisphenol A (meth) acrylate, bisphenol A diglycidyl ether and (meth) Epoxy ring-opening of bisphenol A epoxy (meth) acrylate, tetrabromobisphenol A diglycidyl ether and (meth) acrylic acid obtained by epoxy ring-opening reaction with acrylic acid Tetrabromobisphenol A epoxy (meth) acrylate obtained by reaction, bisphenol F epoxy (meth) acrylate obtained by epoxy ring-opening reaction of bisphenol F diglycidyl ether and (meth) acrylic acid, tetrabromobisphenol F diglycidyl ether and And tetrabromobisphenol F epoxy (meth) acrylate obtained by epoxy ring-opening reaction with (meth) acrylic acid. These polyfunctional monomers can be used alone or in combination of two or more.

  Among them, ethylene oxide-added bisphenol A (meth) acrylic acid ester, ethylene oxide-added tetrabromobisphenol A (meth) acrylic acid ester, bisphenol A epoxy obtained by epoxy ring-opening reaction of bisphenol A diglycidyl ether and (meth) acrylic acid ( Particularly preferred are (meth) acrylates, tetrabromobisphenol A epoxy (meth) acrylates, and the like.

  Examples of commercially available di (meth) acrylates having a structure represented by the formula (1) include, for example, Biscote # 700, # 540 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronix M-208, M- 210 (above, manufactured by Toagosei Co., Ltd.), NK ester BPE-100, BPE-200, BPE-500, A-BPE-4 (above, manufactured by Shin-Nakamura Chemical Co., Ltd.), light ester BP-4EA, BP -4PA, epoxy ester 3002M, 3002A, 3000M, 3000A (manufactured by Kyoeisha Chemical Co., Ltd.), KAYARAD R-551, R-712 (manufactured by Nippon Kayaku Co., Ltd.), BPE-4, BPE-10 BR-42M (Daiichi Kogyo Seiyaku Co., Ltd.), Lipoxy VR-77, VR-60, VR-90, SP-1506, SP-1506, SP-150 , SP-1509, SP-1563 (or more, Showa High Polymer Co., Ltd.), NEOPOL V779, NEOPOL V779MA (manufactured by Japan U-PICA Co., Ltd.), and the like.

  On the other hand, examples of the monofunctional monomer include acrylamide, (meth) acryloylmorpholine, 7-amino-3,7-dimethyloctyl (meth) acrylate, isobutoxymethyl (meth) acrylamide, and isobornyloxyethyl (meth) acrylate. , Isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyldiethylene glycol (meth) acrylate, t-octyl (meth) acrylamide, diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate , Lauryl (meth) acrylate, dicyclopentadiene (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate N, N-dimethyl (meth) acrylamide tetrachlorophenyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, tetrabromophenyl (meth) acrylate, tribromophenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , 2-hydroxypropyl (meth) acrylate, vinylcaprolactam, N-vinylpyrrolidone, butoxyethyl (meth) acrylate, pentachlorophenyl (meth) acrylate, pentabromophenyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol In addition to mono (meth) acrylate, isobornyl (meth) acrylate, methyltriethylenediglycol (meth) acrylate, etc., represented by formula (2) Specific examples of mono (meth) acrylates having a structure such as phenoxyethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, and 3-phenoxy-2-hydroxypropyl P- reacted with (meth) acrylate, 2-phenylphenoxyethyl (meth) acrylate, 4-phenylphenoxyethyl (meth) acrylate, 3- (2-phenylphenyl) -2-hydroxypropyl (meth) acrylate, ethylene oxide Cumylphenol (meth) acrylate, 2-bromophenoxyethyl (meth) acrylate, 4-bromophenoxyethyl (meth) acrylate, 2,4-dibromophenoxyethyl (meth) acrylate, 2,6-dibu Examples include lomophenoxyethyl (meth) acrylate, 2,4,6-tribromophenyl (meth) acrylate, 2,4,6-tribromophenoxyethyl (meth) acrylate, and the like. These monofunctional monomers can be used alone or in combination of two or more.

  Among them, phenoxyethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, (meth) acrylate of p-cumylphenol reacted with ethylene oxide, 2,4,6-tribromophenoxyethyl (meth) acrylate, Particularly preferably used.

  Examples of commercially available mono (meth) acrylates having a structure represented by the formula (2) include, for example, Aronix M113, M110, M101, M102, M5700, TO-1317 (above, manufactured by Toagosei Co., Ltd.), and Biscoat. # 192, # 193, # 220, 3BM (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), NK ester AMP-10G, AMP-20G (above, made by Shin-Nakamura Chemical Co., Ltd.), light acrylate PO-A , P-200A, epoxy ester M-600A (above, manufactured by Kyoeisha Chemical Co., Ltd.), PHE, CEA, PHE-2, BR-30, BR-31, BR-31M, BR-32 (above, Daiichi Kogyo) Pharmaceutical Co., Ltd.).

When the object to be formed of the present invention is an optical waveguide, the refractive index (n _D ²⁵ : 25 ° C., Na-D line having a wavelength of 589 nm) after curing of the radical polymerizable compound is 1.53 or more. This is preferable because an appropriate refractive index difference can be provided between the cladding and the cladding. For the above reasons, the refractive index after curing of the radical polymerizable compound is more preferably 1.54 or more. In addition, when a radically polymerizable compound consists of 2 or more types of compounds, the refractive index of a radically polymerizable compound says the refractive index of the whole radically polymerizable compound, ie, an average refractive index.
Although the said hardening body consists mainly of the hardened | cured material of a radically polymerizable compound, in fact, a cationically polymerizable compound may be contained.

(B) Photoradical polymerization initiator Although the kind in particular of radical photopolymerization initiator is not restrict | limited, For example, the photoradical polymerization initiator whose photosensitive wavelength is 400-800 nm is mentioned.
Here, the photoradical polymerization initiator having a photosensitive wavelength of 400 to 800 nm refers to a photoradical polymerization initiator having substantial light absorption at 400 to 800 nm, and strictly absorbs only light having a wavelength of 400 to 800 nm. Does not mean to do.
Examples of the photo radical polymerization initiator having a photosensitive wavelength of 400 to 800 nm include xanthone, fluorenone, fluorene, anthraquinone, carbazole, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino -Propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, and the like.
Examples of commercially available photo radical polymerization initiators having a photosensitive wavelength of 400 to 800 nm include, for example, Irgacure 369, 500, 819, 907, 784, 2959, CGI 1700, CGI 1750, CGI 11850 (above, manufactured by Ciba Specialty Chemicals Co., Ltd.) ), Lucirin LR8728 (manufactured by BASF) and the like.
In addition, a radical photopolymerization initiator may be used individually by 1 type, and may use 2 or more types together.

(C) Cationic polymerizable compound Examples of the cationic polymerizable compound include compounds having a cyclic ether structure.
Here, examples of the compound having a cyclic ether structure include alicyclic epoxy compounds such as oxirane compounds, oxetane compounds, and oxolane compounds.
Examples of oxirane compounds include epoxy novolac resins, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol. Diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, propylene oxide modified bisphenol A diglycidyl ether, pentaerythritol triglycidyl ether, penta Erythritol tetraglycidyl ester Ter, diglycerol tetraglycidyl ether, diglycerol triglycidyl ether, sorbitol hexaglycidyl ether, sorbitol pentaglycidyl ether, sorbitol tetraglycidyl ether, sorbitol triglycidyl ether; Examples thereof include polyglycidyl ethers and polycyclohexene oxides obtained by adding the above alkylene oxides and caprolactones.

  Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (phenoxyethyl) oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, di [1-ethyl- ( 3-oxetanyl)] methyl ether, 3-ethyl-3-[[3- (triethoxysilyl) propoxy] methyl] oxetane, 1,4-bis [[(3-ethyl-3-oxetanyl) methoxy] methyl] benzene 1,2-bis [[(3-ethyl-3-oxetanyl) methoxy] methyl] benzene, 1,3-bis [[(3-ethyl-3-oxetanyl) methoxy] methyl] benzene, trimethylolpropane tris ( 3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris (3-ethyl-3-oxeta) Rumethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, ethylene oxide modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, propylene oxide modified bisphenol A bis (3-ethyl-3-oxetanyl) Methyl) ether, ethylene oxide modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, propylene oxide modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, ethylene oxide modified bisphenol F bis (3 -Ethyl-3-oxetanylmethyl) ether, oxetanylsilsesquioxane, phenol novolac oxetane, 3,4-epoxycyclohexylmethyl-3 ', 4'- It can be exemplified port carboxymethyl cyclohexane carboxylate.

Examples of oxolane compounds include 2,2-dimethyl-1,3-dioxolane, 2,2-diethyl-1,3-dioxolane, 2-methyl-2-ethyl-1,3-dioxolane, and 2-cyclohexyl-1. , 3-dioxolane, 2-methyl-2-isobutyl-1,3-dioxolane, and the like.
Examples of commercially available cationic polymerizable compounds include UVR-6100, 6105, 6110, 6128, 6200, 6216 (manufactured by Union Carbide), Celoxide 2021, 2021P, 2081, 2083, 2085, Epolide GT-300, 301, 302, 400, 401, 403, PB3600, PB4700 (above, manufactured by Daicel Chemical Industries, Ltd.), KRM-2100, 2110, 2199, 2400, 2410, 2408, 2490, 2720, 2750 (above, Asahi Denka Kogyo) Manufactured by Co., Ltd.), Epicoat 828, 812, 1031, 872, CT508 (and above, manufactured by Japan Epoxy Resin Co., Ltd.), Denacol EX-611, 612, 512, 521, 411, 421, 313, 314, and 321 (and above) Manufactured by Nagase Kasei Co., Ltd. , Epolite 40E, 100E, 70P, 200P, 400P, 1500NP, 1600, 80MF, 100MF, 4000, 3002 (above, manufactured by Kyoeisha Chemical Co., Ltd.), OXA, XDO, POX, DOX, EHOX (above, Toagosei Co., Ltd. )), MMDOL30, MEDOL30, MIBDOL30, CHDOL30, MEDOL10, MIBDOL10, CHDOL10 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and the like.

When the object to be formed of the present invention is an optical waveguide, the refractive index (n _D ²⁵ ) after curing of the cationic polymerizable compound is preferably less than 1.53, and more preferably 1.52 or less. .
When the cationic polymerizable compound is composed of two or more compounds, the “refractive index after curing of the cationic polymerizable compound (n _D ²⁵ )” means the refractive index of the entire two or more cationic polymerizable compounds, that is, The average refractive index.

The content rate of each compound in the photosensitive composition used by this invention is as follows.
The content of the radical polymerizable compound is preferably 5 to 70% by mass, more preferably 10 to 50% by mass, and particularly preferably 15 to 35% by mass.
The content of the photo radical polymerization initiator is preferably 0.1 to 3% by mass, more preferably 0.2 to 2% by mass.
The content of the cationically polymerizable compound is preferably 25 to 90% by mass, more preferably 40 to 90% by mass, and particularly preferably 55 to 85% by mass.
In addition, antioxidant, a ultraviolet absorber, a light stabilizer, a coating surface improvement agent, a thermal polymerization inhibitor etc. can be mix | blended with the photosensitive composition used by this invention as needed.
To prepare the photosensitive composition, after putting each component in a predetermined container, using a stirring means such as a magnetic blending stirring using a rolling blender, a paint shaker, or a rotating blade, until a uniform mixed solution is obtained. What is necessary is just to stir.
The viscosity of the photosensitive composition before curing is preferably 10 to 10,000 mPa · s (cps), more preferably 100 to 5,000 mPa · s. When the viscosity is less than 10 mPa · s, the operability is lowered, and when the viscosity exceeds 10,000 mPa · s, the applicability is lowered.
The photosensitive composition is usually prepared without a solvent.

[Step (b)]
In the step (b), from the upper surface of the photosensitive composition applied in the step (a), in the presence of 1% by volume or more of oxygen relative to the region where the cured body is formed, In this step, the cured product is formed by irradiating light containing a photosensitive wavelength and curing the radical polymerizable compound.
By performing light irradiation (exposure) in the presence of 1% by volume or more of oxygen (for example, in an air atmosphere), photo radical polymerization is inhibited in the surface layer portion near the upper surface of the coating film of the photosensitive composition. Oxygen having an action can inhibit radical polymerization and prevent the curing of the photosensitive composition. That is, an uncured portion having a thickness of several μm can remain above the cured body formed by light irradiation.
The oxygen concentration in the atmosphere at the time of light irradiation is 1% or more, preferably 5% or more, more preferably 10% or more. The atmosphere containing 10% or more oxygen includes air.
In addition, when light irradiation (exposure) is performed in the absence of a gas that inhibits photoradical polymerization (for example, in a nitrogen atmosphere), curing proceeds from the upper surface to the lower surface of the coating layer of the photosensitive composition. To do. Here, “in the absence of a gas that inhibits photoradical polymerization” means that the gas that inhibits photoradical polymerization is contained only to the extent that it is not substantially affected by the inhibition of photoradical polymerization. In this case, the boundary between the cured portion and the uncured portion after the light irradiation becomes clear, and there is an advantage that the waveguide loss when the optical waveguide is formed is reduced, but the upper surface of the cured body of the photosensitive composition is exposed. Therefore, a step of forming a coating layer on the cured body is necessary, and the manufacturing efficiency of the optical member is reduced as compared with the method of the present invention. The oxygen concentration for obtaining the advantage is less than 1%, preferably 0.1% or less, more preferably 0.01% or less.
In the present invention, as a method for irradiating only light of a predetermined wavelength, a method using a mask aligner that allows exposure through a filter that selectively transmits only light of a predetermined wavelength, or laser light is used. Methods and the like.
As a method for irradiating light from the upper surface of the photosensitive composition to the region where the cured body is formed, light irradiation using a micromirror or a mask having a predetermined pattern shape with an aligner or the like is used. Examples include light irradiation and drawing using laser light.

[Step (c)]
Step (c) is a step of heating at a temperature capable of curing (C) the cationic polymerizable compound to form a coated cured body around and / or on the cured body.
The heating temperature in this step is preferably 25 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 60 ° C. or higher. When the heating temperature is less than 25 ° C., the curing of the thermosetting cationic polymerizable compound is slow and the productivity is lowered.
The upper limit of the heating temperature in this step is not particularly limited, but is preferably 150 ° C. or less, more preferably 130 ° C. or less, and particularly preferably 110 ° C. or less from the viewpoint of cost and the like.
Although heating time changes also with kinds of cationically polymerizable compound, Preferably it is 0.1 to 10 hours, More preferably, it is 0.5 to 6 hours.
This step may be performed in an air atmosphere, but is performed in an inert atmosphere that does not contain oxygen (for example, in a nitrogen atmosphere) in order to prevent the surface of the optical member manufactured in the present invention from being oxidized. Is preferred.

[B. When forming a coated cured body by light irradiation]
The method for forming an optical member of the present invention includes a cured body on a substrate, and a coated cured body having a refractive index smaller than that of the cured body, which is formed around and / or on the cured body. A method for forming an optical member comprising: (a) (A) a radical polymerizable compound, (B) a photo radical polymerization initiator, (C) a cation polymerizable compound, and (D) a photo cation polymerization start. A step of applying a photosensitive composition containing an agent on the substrate; and (b) 1% by volume or more with respect to a region where the cured body is formed from the upper surface of the applied photosensitive composition. (B) irradiating light containing the photosensitive wavelength of the photo radical polymerization initiator in the presence of oxygen, and (A) forming the cured product by curing the radical polymerizable compound; and (c) (C ) Irradiation with light containing the photosensitive wavelength of the cationic photopolymerization initiator, Forming a coated cured body around the body and / or on the cured body, (B) the photoradical polymerization initiator has a photosensitive wavelength of 400 nm to 800 nm, and 400 nm to 800 nm ( B) The photoradical polymerization initiator is sensitive but (D) the photocationic polymerization initiator is not sensitive to the wavelength (λ1), and the light irradiated in the step (b) has the wavelength (λ1). It is a feature.
The method of forming the optical member is applicable to the formation of the core portion and cladding of the optical waveguide, and the formation of a plurality of microlenses and protective layers on the solid-state imaging device. It is the same as “when a body is formed”.

[Step (a)]
In step (a), the photosensitive composition containing (A) a radical polymerizable compound, (B) a photo radical polymerization initiator, (C) a cation polymerizable compound, and (D) a photo cation polymerization initiator, This is a step of coating on a substrate.
Among these, about component (A)-(C), it is the same as that of the above-mentioned "A. When a coating hardening body is formed by heating."
However, as the component (B) (photo radical polymerization initiator), those having a photosensitive wavelength of 400 to 800 nm are used.
In the present invention, in consideration of the photosensitivity wavelength of a commercially available photopolymerization initiator, the photoradical polymerization initiator having a photosensitivity wavelength of usually 400 to 800 nm and a photosensitivity wavelength described later of 200 nm or more and less than 400 nm are used. A combination of (D) a cationic photopolymerization initiator is used.

(D) Photocationic polymerization initiator In the case where a cured coating is formed by light irradiation, (B) the photocationic polymerization initiator is not sensitive to (B) the photoradical polymerization initiator at 400 nm to 800 nm. It is necessary that the wavelength (λ1) exists.
Examples of the (D) photocationic polymerization initiator that satisfies this condition include a photocationic polymerization initiator having a photosensitive wavelength of 200 nm or more and less than 400 nm.
The photocationic polymerization initiator having a photosensitive wavelength of 200 nm or more and less than 400 nm means a photocationic polymerization initiator having substantial light absorption in a wavelength range of 200 nm or more and less than 400 nm, strictly 200 nm or more and less than 400 nm. It does not mean that only light having a wavelength of is absorbed.
Although it does not specifically limit as this photocationic polymerization initiator, For example, the onium salt which has a structure represented by following formula (3) can be mentioned. This onium salt is a compound that releases Lewis acid upon receiving light.
_{^{[R 3 a R 4 b R}} 5 c R 6 d Z] m + [MX n + m] m- (3)
(Wherein the cation is an onium ion, Z represents S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl or N≡N, and R ³ , R ⁴ , R ⁵ and R ⁶ represents the same or different organic groups, a, b, c and d are each an integer of 0 to 3, and (a + b + c + d) is equal to the valence of Z. M is a halide complex [ MX _{n + m} ] represents a metal or metalloid constituting the central atom of, for example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc. X is a halogen atom such as F, Cl, Br, etc., m is the net charge of the halide complex ion, and n is the valence of M.)

In the above formula (3), specific examples of onium ions include diphenyliodonium, 4-methoxydiphenyliodonium, bis (4-methylphenyl) iodonium, bis (4-tert-butylphenyl) iodonium, bis (dodecylphenyl) iodonium. , Triphenylsulfonium, diphenyl-4-thiophenoxyphenylsulfonium, bis [4- (diphenylsulfonio) -phenyl] sulfide, bis [4- (di (4- (2-hydroxyethyl) phenyl) sulfonio) -phenyl] And sulfide, η ⁵ -2,4- (cyclopentadienyl) [1,2,3,4,5,6-η]-(methylethyl) -benzene] -iron (1+) and the like.

In the above formula (3), specific examples of the anion [MX _{n + m} ] include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarsenate. (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ) and the like.

Moreover, the onium salt which has an anion represented with general formula [MXn (OH) _< ^- >] can be used. Further, perchlorate ion (ClO ₄ ⁻ ), trifluoromethane sulfonate ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluene sulfonate ion, trinitrobenzene sulfonate anion, trinitrotoluene sulfonate Onium salts having other anions such as anions can also be used.

  Among such onium salts, an aromatic acid onium salt is a particularly effective photoacid generator as a photocationic polymerization initiator. For example, aromatic halonium salts described in JP-A-50-151996, JP-A-50-158680, etc., JP-A-50-151997, JP-A 52-30899, JP-A 56- Group VIA aromatic onium salts described in Japanese Patent No. 55420, Japanese Patent Laid-Open No. 55-125105, Group VA aromatic onium salts described in Japanese Patent Laid-Open No. 50-158698, Japanese Patent Laid-Open No. 56-8428 Oxosulfoxonium salts described in JP-A-56-149402, JP-A-57-192429, etc., aromatic diazonium salts described in JP-A-49-17040, US Pat. The thiobililium salts described in 139, 655 are preferred. Moreover, an iron / allene complex, an aluminum complex / photolytic silicon compound-based initiator, and the like can also be mentioned.

Examples of commercially available photoacid generators that can be suitably used as a photocationic polymerization initiator include UVI-6950, UVI-6970, UVI-6974, UVI-6990 (manufactured by Union Carbide), Adekaoptomer SP-150, SP-151, SP-170, SP-172 (above, manufactured by Asahi Denka Kogyo Co., Ltd.), Irgacure 261 (above, made by Ciba Specialty Chemicals Co., Ltd.), CI-2481, CI-2624 CI-2039, CI-2064 (above, Nippon Soda Co., Ltd.), CD-1010, CD-1011, CD-1012 (above, Sartomer), DTS-102, DTS-103, NAT-103, NDS-103, TPS-103, MDS-103, MPI-103, BBI-103 (Midori Chemical ( Co., Ltd.), PCI-061T, PCI-062T, PCI-020T, PCI-022T (Nippon Kayaku Co., Ltd.) and the like. Among these, UVI-6970, UVI-6974, Adekaoptomer SP-170, SP-172, CD-1012, and MPI-103 can exhibit high photocuring sensitivity in the composition containing them. This is particularly preferable because it can be performed.
Said photo-acid generator can comprise a photocationic polymerization initiator individually by 1 type or in combination of 2 or more types.

The content rate of each compound in the photosensitive composition used by this invention is as follows.
The content of the photo radical polymerizable compound is preferably 5 to 70% by mass, more preferably 10 to 50% by mass, and particularly preferably 15 to 35% by mass.
The content of the photo radical polymerization initiator is preferably 0.1 to 3% by mass, more preferably 0.2 to 2% by mass.
The content of the cationically polymerizable compound is preferably 25 to 90% by mass, more preferably 40 to 90% by mass, and particularly preferably 55 to 85% by mass.
The content rate of a photocationic polymerization initiator becomes like this. Preferably it is 0.1-3 mass%, More preferably, it is 0.2-2 mass%.
In addition to the components (A) to (D), the components that can be blended as necessary, the preparation method of the photosensitive composition, the viscosity of the photosensitive composition before curing, etc., are described in “A. It is the same as “when a body is formed”.

[Step (b)]
The step (b) is the same as the step (b) in the above-mentioned “A. When forming a coated cured body by heating” except that the wavelength of light to be irradiated is limited to the following.
The wavelength of the light irradiated in this step is a wavelength (λ1) where (B) the photo radical polymerization initiator is exposed to light but (D) the photo cationic polymerization initiator is not exposed.
Therefore, in the same manner as in “A. When forming a coated cured body by heating”, only the (A) radical polymerizable compound is cured to form a cured body mainly composed of the (A) radical polymerizable compound. be able to. Moreover, since light is irradiated in the presence of 1% by volume or more of oxygen, an uncured portion having a thickness of several μm can remain above the cured body formed by light irradiation.

[Step (c)]
In the step (c), the coated cured body is formed around the cured body and / or on the cured body formed in the step (b) by irradiating light containing the photosensitive wavelength of the photocationic polymerization initiator (C). Is a step of forming.
(C) As light including the photosensitive wavelength of a photocationic polymerization initiator, the light which has a wavelength of 200 nm or more and less than 400 nm is mentioned, for example.

  Embodiments of the optical member forming method of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart showing an example of a method for forming an optical waveguide according to the present invention, FIG. 2 is a flowchart showing an example of a method for forming a microlens array according to the present invention, and FIG. 3 shows an exposure under a nitrogen atmosphere. It is a flowchart which shows the reference example of the formation method of the optical waveguide at the time of hardening a radically polymerizable compound.

In FIG. 1, a liquid photosensitive composition containing components (A) to (D) used in the present invention on a silicon substrate 1, or (C) a cationic polymerizable compound in the photosensitive composition and ( D) After applying a liquid composition containing only a photocationic polymerization initiator at a predetermined thickness (about 20 μm), it is cured by irradiation with light (for example, light with a wavelength of 365 nm) in a nitrogen atmosphere. The lower clad 2 is formed ((A) in FIG. 1).
The silicon substrate 1 and the lower clad 2 correspond to the base in the present invention. Instead of the lower clad 2, an inorganic material layer such as a silicon oxide film may be formed.
Next, the liquid photosensitive composition 3 used in the present invention is applied to the upper surface of the lower clad 2 at a predetermined thickness (30 to 40 μm) to form a thin film for the core ((B) in FIG. 1). ), By partially irradiating the core thin film with light 5 having a wavelength of 400 to 800 nm (for example, light having a wavelength of 405 nm) through the mask 4 having a predetermined pattern shape in an air atmosphere. Hardened body) 6 is formed ((C) in FIG. 1).
Subsequently, in a nitrogen atmosphere, light having a wavelength of less than 400 nm (for example, light having a wavelength of 365 nm) 7 is irradiated on the entire surface of the thin film for the core to cure the uncured portion other than the core portion 6 to form the upper cladding. (Coating cured body) 8 is formed. Thus, the optical waveguide having the core portion 6 and the two clads 2 and 8 is completed ((D) in FIG. 1).

In FIG. 2, a liquid photosensitive composition 11 containing components (A) to (D) used in the present invention is applied on a substrate 10 at a predetermined thickness (about 50 μm), and a microlens thin film. (A in FIG. 2), the light 13 having a wavelength of 400 to 800 nm (for example, light having a wavelength of 405 nm) 13 is micronized in an air atmosphere through the mask 12 having a predetermined pattern shape. The lens thin film is partially irradiated to form a plurality of microlenses (cured bodies) 14 scattered in a lattice shape ((B) in FIG. 2).
Subsequently, light having a wavelength of less than 400 nm (for example, light having a wavelength of 365 nm) 15 is irradiated on the entire surface of the microlens thin film to cure the uncured portion other than the microlens 14, thereby protecting the protective layer (covered cured body). ) 16 is formed. Thus, a microlens array is completed ((C) in FIG. 2).

In FIG. 3, first, a liquid photosensitive composition containing components (A) to (D) used in the present invention on a silicon substrate 21, or (C) a cationic polymerizable compound in the photosensitive composition. And (D) by applying a liquid composition containing only the photocationic polymerization initiator at a predetermined thickness (about 20 μm), and then irradiating with light (for example, light having a wavelength of 365 nm) under a nitrogen atmosphere, or by heating. Then, the lower clad 22 which is a cured body is formed ((A) in FIG. 3).
Next, a liquid photosensitive composition 23 containing components (A) to (D) used in the present invention is applied to the upper surface of the lower clad 22 at a predetermined thickness (30 to 40 μm) to form a core thin film. (B in FIG. 3), light having a wavelength of 400 to 800 nm (for example, light having a wavelength of 405 nm) 25 is supplied to the core thin film through a mask 24 having a predetermined pattern shape in a nitrogen atmosphere. Is partially irradiated to form a core part (cured body) 26 ((C) in FIG. 3).
Subsequently, under a nitrogen atmosphere, light having a wavelength of less than 400 nm (for example, light having a wavelength of 365 nm) 27 is irradiated on the entire surface of the thin film for the core to cure the uncured portion other than the core portion 26, thereby (Coated cured body) 28 is formed ((D) in FIG. 3).
Finally, after applying the same composition as the material for forming the lower clad 22 on the upper surface of the layer including the core portion 26 and the intermediate clad 28 with a predetermined thickness (about 20 μm), light in a nitrogen atmosphere (for example, The entire surface is irradiated with light having a wavelength of 365 nm to form an upper clad 29 that is a cured body. Thus, an optical waveguide having the core portion 26 and the three layers of clads 22, 28 and 29 is completed ((E) in FIG. 3).
In the method shown in FIGS. 1 to 3, instead of the photosensitive composition containing the components (A) to (D), the photosensitive composition containing the components (A) to (C) is used, and the coated cured body is used. The clad of the optical waveguide or the protective layer of the microlens array may be cured by heating (for example, 80 ° C., 1 hour).

Examples of the present invention will be described below. In the following text, “part” represents part by mass.
[Example 1]
(1) Preparation of photosensitive composition (a) Materials used Materials used are as follows.
“VR77”: bisphenol A polyepoxy diacrylate (manufactured by Showa Polymer Industries Co., Ltd .; refractive index of cured product: 1.56)
“Irgacure 819”: tri (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by Ciba Specialty Chemicals)
“XDO”: 1,4-bis [[(3-ethyl-3-oxetanyl) methoxy] methyl] benzene (manufactured by Toagosei Co., Ltd .; refractive index of cured product: 1.51)
“Celoxide 2021P”: 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate (manufactured by Daicel Chemical Industries, Ltd .; refractive index of cured product: 1.51)
“SP172”: triallylsulfonium hexafluoroantimonate salt mixture (Asahi Denka Kogyo Co., Ltd.)
(B) Preparation method “VR77” 24.5 parts, “Irgacure 819” 0.5 part, “XDO” 63.75 parts, “Celoxide 2021P” 10.5 parts, “SP172” 0.75 part were charged, and the liquid temperature The mixture was stirred for 1 hour while controlling at 50 to 60 ° C. to obtain a liquid photosensitive composition.

(2) Formation of Lower Cladding The liquid photosensitive composition was applied on a 4-inch silicon substrate by spin coating so as to have a film thickness of 20 μm, thereby forming a lower cladding thin film. Place the bandpass filter on the quartz glass placed in the mask holder, and use a mask aligner that can be selectively exposed to 365 nm light, and irradiate the lower cladding thin film at 1 J / cm ^{2 in} a nitrogen atmosphere. The entire surface was exposed in the amount to form a lower clad.
(3) Formation of layer including core portion and upper clad On the lower clad, the liquid photosensitive composition was applied by spin coating so as to have a film thickness of 35 μm to form a thin film for core.
Using a mask aligner that can be selectively exposed to light of 405 nm by a band-pass filter, and through a mask prepared so that light is irradiated to a portion forming the core portion, the above-described thin film for core in an air atmosphere Was partially exposed at a dose of ³ J / cm ² to form a core (cured body).
Subsequently, using a mask aligner in the same state as when the lower clad was formed, the core thin film was exposed at a dose of 1 J / cm ² under a nitrogen atmosphere, and uncured portions around and above the core portion were exposed. Curing was performed to form an upper clad (covered cured body), and the optical waveguide was completed.
When the waveguide loss at 850 nm of the optical waveguide was measured, it was 2 dB / cm.

[Example 2]
The liquid photosensitive composition was applied onto a glass substrate by spin coating so as to have a film thickness of 50 μm, thereby forming a microlens thin film.
Using a mask aligner that can be selectively exposed to light of 405 nm by a band-pass filter, through a mask prepared so that light is irradiated to a portion where the microlens is to be formed, in the air atmosphere, the microlens The thin film was partially exposed at a dose of ³ J / cm ² to form microlenses (cured bodies) scattered in a lattice pattern.
Subsequently, a band pass filter was placed on the quartz glass placed in the mask holder, and a mask aligner that was selectively exposed to 365 nm light was used to form a microlens thin film at 1 J / cm ² under a nitrogen atmosphere. The entire surface was exposed with an irradiation amount, and the uncured portion around and above the microlens was cured to form a protective layer (coated cured body).

[Reference Example 1]
The same operation as in Example 1 was performed except that the core portion was formed in a nitrogen atmosphere (oxygen concentration of 100 ppm or less).
Thereafter, the liquid photosensitive composition is applied by spin coating on the layer including the core portion and the surrounding cladding (intermediate cladding) to form a thin film for upper cladding. did. Irradiation of the upper cladding thin film at 1 J / cm ^{2 in} a nitrogen atmosphere using a mask aligner placed on a quartz glass placed in a mask holder and selectively exposed with 365 nm light. The entire surface was exposed with an amount to form an upper clad. This completed the optical waveguide.
When the waveguide loss at 850 nm of the optical waveguide was measured, it was 0.35 dB / cm.

It is a flowchart which shows an example of the formation method of the optical waveguide of this invention. It is a flowchart which shows an example of the formation method of the micro lens array of this invention. It is a flowchart which shows the reference example of the formation method of an optical waveguide at the time of hardening a radically polymerizable compound by exposure in nitrogen atmosphere.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,21 Silicon substrate 2,22 Lower clad 3,11,23 Photosensitive composition 4,12,24 Mask 5,13,25 Light of wavelength 405nm 6,26 Core part (hardened body)
7, 15, 27 Light with a wavelength of 365 nm 8, 29 Upper clad 28 Intermediate clad (coated hardened body)
10 Substrate 14 Microlens 16 Protective layer (Coating cured body)

Claims (6)

A method for forming an optical member comprising a cured body and a coated cured body having a refractive index smaller than that of the cured body formed on and around the cured body on the substrate. There,
(A) The following components (A) to (C):
(A) radical polymerizable compound (B) photo radical polymerization initiator (C) a step of applying a photosensitive composition containing a cationic polymerizable compound on the substrate;
(B) From the upper surface of the coated photosensitive composition, the photosensitive wavelength of the (B) radical photopolymerization initiator is set in the presence of 1% by volume or more of oxygen with respect to the region where the cured body is formed. Irradiating light containing and forming the cured body by curing the radically polymerizable compound (A),
(C) heating at a temperature at which the cationic polymerizable compound (C) can be cured, and forming the coated cured body around and / or on the cured body. A method for forming an optical member. A method for forming an optical member comprising a cured body and a coated cured body having a refractive index smaller than that of the cured body formed on and around the cured body on the substrate. There,
(A) The following components (A) to (D):
(A) radical polymerizable compound (B) photo radical polymerization initiator (C) cation polymerizable compound (D) a step of applying a photosensitive composition containing a photo cation polymerization initiator on the substrate;
(B) From the upper surface of the coated photosensitive composition, the photosensitive wavelength of the (B) radical photopolymerization initiator is set in the presence of 1% by volume or more of oxygen with respect to the region where the cured body is formed. Irradiating light containing and forming the cured body by curing the radically polymerizable compound (A),
(C) (C) irradiating light containing a photosensitive wavelength of the photocationic polymerization initiator to form the coated cured body around and / or on the cured body,
The (B) photoradical polymerization initiator has a photosensitive wavelength at 400 nm to 800 nm, and the (B) photoradical polymerization initiator is photosensitive at 400 nm to 800 nm, but the (D) photocationic polymerization initiator is There is a wavelength (λ1) that is not exposed,
The method of forming an optical member, wherein the wavelength of the light irradiated in the step (b) is the wavelength (λ1).   The method for forming an optical member according to claim 1, wherein the (A) radical polymerizable compound is a compound having an acryloyl group.   The method for forming an optical member according to claim 1, wherein the cationic polymerizable compound (C) is a compound having a cyclic ether structure.   The method for forming an optical member according to claim 1, wherein the optical member is an optical waveguide. The method for forming an optical member according to claim 1, wherein the optical member is a microlens array.

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