JP2008242360A - Film type optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film type optical waveguide which is superior in bending durability and transparency. <P>SOLUTION: The film type optical waveguide 24 includes a cured film layer 8, a lower clad layer 10 laminated on a top surface of the cured film layer 8, a core part 18 formed on a top surface of the lower clad layer 10 and having a specified width, an upper clad layer 20 laminated on the lower clad layer 10 and core part 18, and a cured film layer 22 laminated on a top surface of the upper clad layer 20. The cured film layers 8 and 22 are formed by optically curing a photocurable resin composition containing (A) 0.1 to 10% by mass of photoacid generator, (B) 15 to 85% by mass of cation polymerizable compound, (C) 0.01 to 10% by mass of radical polymerization initiator, (D) 0.1 to 25% by mass of radical polymerizable compound, (E) 1 to 35% by mass of polyester polyol, and (F) 1 to 35% by mass of elastomer particles of 10 to 1,000 nm measured by an electron microscope method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a film-shaped optical waveguide.

In the multimedia era, optical waveguides are attracting attention as optical transmission media because of the demand for large capacity and high speed information processing in optical communication systems and computers. A typical example of a conventional optical waveguide is a silica-based optical waveguide. However, silica-based optical waveguides require a long process time at a high temperature for the deposition of a quartz film at the time of manufacture. Etching with a high-risk gas is included, and special processes are required for these processes. Many complicated processes and special apparatuses are required, and the yield is low. There are problems such as.
In order to improve these problems, a liquid curable composition is used as a material for the core portion and the cladding layer for the purpose of improving productivity such as reduction in the number of steps of the optical waveguide, shortening of manufacturing time, and increase in yield. A polymer-based optical waveguide to be used has recently been proposed.
As an example, in a polyimide-based optical waveguide whose component is a polyimide obtained from tetracarboxylic dianhydride and diamine, the polyimide is a fluorinated diamine represented by a specific structural formula or a polyimide from a diamine containing the same, or A polyimide optical waveguide characterized by being a mixture thereof has been proposed (Patent Document 1).
This polyimide optical waveguide has good transmission characteristics (low waveguide loss) and has excellent heat resistance.
As another example, (A) a copolymer containing a structural unit having a side chain portion containing a radically polymerizable reactive group bonded via a urethane bond and a structural unit having a side chain that is not polymerizable. A polymer, (B) a compound having one or more ethylenically unsaturated groups in the molecule, a molecular weight of less than 1,000, and a boiling point of 130 ° C. or higher at 0.1 MPa, and (C) a photoradical A photosensitive resin composition for an optical waveguide containing a polymerization initiator has been proposed (Patent Document 2).
According to this photosensitive resin composition, it is possible to form an optical waveguide having high shape accuracy and suppressing deterioration in transmission characteristics under high temperature and high humidity.
Japanese Patent Laid-Open No. 4-9807 JP 2006-146162 A

When the conventional optical waveguide is repeatedly bent in the state of a film-like cured product (film-shaped optical waveguide), there is a problem that breakage and cracks occur, and good transmission characteristics cannot be maintained.
On the other hand, when another member such as a light emitting element is fixed to the lower surface of the film-shaped optical waveguide, the film-shaped optical waveguide has high transparency because the film-shaped optical waveguide is seen through from above and aligned. It is hoped that.
Then, this inventor aims at providing the film-form optical waveguide excellent in bending durability and transparency.

As a result of intensive studies to solve the above problems, the present inventor, in an optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, on the lower surface of the lower cladding layer and the upper surface of the upper cladding layer, It has been found that if a cured film layer made of a photocurable resin composition having a specific component composition is provided, a film-like optical waveguide excellent in bending durability and transparency can be obtained, and the present invention has been completed.
That is, the present invention provides the following [1] to [4].
[1] A film-shaped optical waveguide having a lower clad layer, a core portion, and an upper clad layer, wherein the following components (A) to (A) are formed on the outer surfaces of the lower clad layer and the upper clad layer: A film-like optical waveguide comprising a cured film layer obtained by photocuring a photocurable resin composition containing D) and (F).
(A) Photoacid generator (B) Cationic polymerizable compound (C) Radical polymerization initiator (D) Radical polymerizable compound (F) Elastomer having a number average particle size measured by electron microscopy of 10 to 1,000 nm Particle [2] The film-shaped optical waveguide according to [1], wherein the content of the components (A) to (D) and (F) with respect to the total amount of the photocurable resin composition is as follows.
(A) Photoacid generator 0.1-10 mass%
(B) Cation polymerizable compound 15-85 mass%
(C) Radical polymerization initiator 0.01 to 10% by mass
(D) Radical polymerizable compound 0.1-25 mass%
(F) Elastomer particles having a number average particle diameter of 10 to 1,000 nm measured by electron microscopy 1 to 35% by mass
[3] The film-shaped optical waveguide according to [1] or [2], wherein the photocurable resin composition contains (E) a polyether polyol at a content of 1 to 35% by mass of the total amount of the composition. .
[4] The cured film layer according to any one of [1] to [3], wherein the cured film layer has a transmittance of 80% or more with respect to light having a wavelength of 405 nm when the thickness is 10 μm. Optical waveguide.

Since the film-shaped optical waveguide of the present invention includes a cured film layer made of a photocurable resin composition having a specific component composition, the film-shaped optical waveguide does not cause breakage or cracking even when it is repeatedly bent. Transmission characteristics can be maintained.
Moreover, since the cured film layer which consists of a photocurable resin composition which has a specific component composition has high transparency, the film-form optical waveguide of this invention, and other members, such as a film-form optical waveguide and a light emitting element, When fixing the film, the film-shaped optical waveguide can be seen through and alignment can be performed easily and accurately.

The film-shaped optical waveguide of the present invention has a lower cladding layer, a core portion, and an upper cladding layer, and each outer surface of the lower cladding layer and the upper cladding layer (specifically, the lower surface of the lower cladding layer, And the upper surface of an upper clad layer has a cured film layer which consists of a hardening body of the photocurable resin composition containing several types of specific components.
First, components (A) to (D) and (F) of the photocurable resin composition forming the cured film layer and other components to be blended as necessary will be described in detail.

Ingredient (A)
Component (A) used in the composition of the present invention is a photoacid generator, and is a photocationic polymerization initiator that releases Lewis acid upon receiving light.

Examples of the photoacid generator include an onium salt having a structure represented by the following general formula (1). This onium salt has a substantial light absorption wavelength below 400 nm.
_{^{[R 1 a R 2 b R}} 3 c R 4 d Z] + m [MX n + m] -m (1)
(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 ¹ , R ² , R ³ and R ⁴ represents the same or different organic group, a, b, c and d are each an integer of 0 to 3, and (a + b + c + dm) is equal to the valence of Z. M is a halide. The metal or metalloid which comprises the central atom of a complex [MXn _{+ m} ] is shown, for example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, 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 general formula (1), specific examples of onium ions include diphenyliodonium, 4-methoxydiphenyliodonium, bis (4-methylphenyl) iodonium, bis (4-tert-butylphenyl) iodonium, bis (dodecylphenyl). Diaryliodonium such as iodonium, triarylsulfonium such as triphenylsulfonium and diphenyl-4-thiophenoxyphenylsulfonium, bis [4- (diphenylsulfonio) -phenyl] sulfide, bis [4- (di (4- ( 2-hydroxyethyl) phenyl) sulfonio) -phenyl] sulfide, η ⁵ -2,4- (cyclopentadienyl) [1,2,3,4,5,6-η]-(methylethyl) -benzene] -Iron (1+) etc. are mentioned.
In the general formula (1), specific examples of the anion [MX _{n + m} ] include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarce. Nate (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.

  Photoacid generators preferably used in the present invention are aromatic onium salts such as diaryliodonium salts and triarylsulfonium salts. 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 and JP-A-57-192429, aromatic diazonium salts described in JP-A-49-17040, U.S. 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 include Adekaoptomer SP-150, SP-151, SP-170, SP-172 (above, manufactured by Asahi Denka Kogyo Co., Ltd.), UVI-6950, UVI-6970, UVI- 6974, UVI-6990 (manufactured by Union Carbide), Irgacure 261 (manufactured by Ciba Specialty Chemicals), CI-2481, CI-2624, CI-2638, CI-2064 (manufactured by Nippon Soda Co., Ltd.), CD-1010, CD-1011, CD-1012 (manufactured by 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 (above, Nippon Kayaku Co., Ltd.), CPI-100A, CPI-110A, K-1 (above, San Apro Co., Ltd.) and the like.
Among these, Adeka optomer SP-170, SP-172, UVI-6970, UVI-6974, CD-1012, MPI-103, CPI-100A, CPI-110A, K-1 are high light in the resin composition. It is particularly preferable because curing sensitivity can be expressed.
A photo-acid generator can be used individually by 1 type or in combination of 2 or more types.
A sensitizer may be used in combination in order to promote the generation of acid by the photoacid generator. Examples of the sensitizer include dihydroxybenzene, trihydroxybenzene, hydroxyacetophenone, dihydroxydiphenylmethane, and the like.

  The content of the component (A) in the present invention is preferably 0.1 to 10% by mass, more preferably 0.2 to 8% by mass, and particularly preferably 1 to 8% by mass with respect to the total amount of the composition. . When the content of the component (A) is less than 0.1% by mass, the resulting resin composition has reduced radiation curability, and a film-shaped optical waveguide having sufficient bending durability may not be obtained. is there. On the other hand, when it exceeds 10 mass%, when the resin composition is radiation-cured, sufficient light transmittance cannot be obtained, resulting in poor curing.

Ingredient (B)
Component (B) used in the composition of the present invention is a cationically polymerizable compound, and is a compound that undergoes a polymerization reaction or a crosslinking reaction when irradiated with light in the presence of a cationic photopolymerization initiator.

  (B) Although it does not specifically limit as a cationically polymerizable compound, The compound which has a 2 or more alicyclic epoxy group in 1 molecule is preferable. By containing 50% by mass or more of the compound having two or more alicyclic epoxy groups in one molecule in the total amount of the component (B), a good curing rate and mechanical strength can be maintained.

  (B) Specific examples of the cationically polymerizable compound include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol. S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxy 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexane Silmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, ε-caprolactone Modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone Modified 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), di (3,4-epoxycyclohexylmethyl) of ethylene glycol Ether, ethylenebis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxycyclohexahydrophthalate, di-2-ethylhexyl epoxycyclohexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6- Hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ethers; Polyglycidyl ether of a polyether polyol obtained by adding one or more alkylene oxides to a monohydric alcohol Ethers; diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; monoglycidyl ethers of polyether alcohols obtained by adding phenol, cresol, butylphenol or alkylene oxide; higher fatty acids Epoxidized soybean oil; butyl epoxy stearate; octyl epoxy stearate; epoxidized linseed oil; epoxidized polybutadiene and the like. Said cationically polymerizable compound can comprise (B) component individually by 1 type or in combination of 2 or more types.

  Among these cationically polymerizable compounds, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, ε-caprolactone modified 3,4-epoxycyclohexyl Methyl-3 ′, 4′-epoxycyclohexylcarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3,4-epoxycyclohexyl Methyl-3 ′, 4′-epoxycyclohexanecarboxylate, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, etc. Is preferred.

  More preferably, two or more alicyclic epoxy groups per molecule, such as 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, etc. It is a compound which has this. In order to maintain a good curing rate and mechanical strength, it is desirable that this epoxy compound is contained in the component (B) in a proportion of 50% by mass or more.

  (B) Examples of commercially available cationic polymerizable compounds include UVR-6100, UVR-6105, UVR-6110, UVR-6128, UVR-6200, UVR-6216 (manufactured by Union Carbide), Celoxide 2021, and Celoxide 2021P. Celoxide 2081, Celoxide 2083, Celoxide 2085, Epolide GT-300, Epolide GT-301, Epolide GT-302, Epolide GT-400, Epolide 401, Epolide 403 (above, manufactured by Daicel Chemical Industries, Ltd.), KRM-2100 KRM-2110, KRM-2199, KRM-2400, KRM-2410, KRM-2408, KRM-2490, KRM-2200, KRM-2720, KRM-2750 (above, manufactured by Asahi Denka Kogyo Co., Ltd.) , Rapi-cure DVE-3, CHVE, PEPC (above, ISP) Epicoat 828, Epicoat 812, Epicoat 1031, Epicoat 872, Epicoat CT508 (above, Japan Epoxy Resin Co., Ltd.), XDO (above, Toagosei Co., Ltd.) Company-made), VECOMER 2010, 2020, 4010, 4020 (above, made by Allied Signal).

  The content of the component (B) in the composition of the present invention is preferably 15 to 85% by mass, more preferably 30 to 80% by mass, and particularly preferably 40 to 75% by mass with respect to the total amount of the composition. . When the content of the component (B) exceeds 85% by mass, the curing rate tends to decrease and the mechanical strength tends to decrease. On the other hand, when it is less than 15% by mass, the bending durability tends to decrease.

Ingredient (C)
Component (C) used in the composition of the present invention is a radical polymerization initiator, which is a compound that decomposes by receiving radiation such as light and initiates the radical polymerization reaction of component (D) by the generated radicals. .

  Specific examples of the (C) radical polymerization initiator include, for example, acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4- Chlorobenzophenone, 4,4′-diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone compound, 2-methyl-1- [4- (methylthio) phenyl]- 2-morpholino-propan-2-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphine oxide Bis (2,6-dimethoxy Benzoyl) -2,4,4-tri-methylpentylphosphine oxide, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde Benzoin ethyl ether, benzoin propyl ether, benzophenone, Michler ketone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone (BTTB), and BTTB and xanthene, thioxanthene, Combinations with coumarin, ketocoumarin and other dye sensitizers can be mentioned. Of these, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1- On or the like is particularly preferable. Said radical polymerization initiator can comprise a component (C) individually by 1 type or in combination of 2 or more types.

  Content of the component (C) in the composition of this invention becomes like this. Preferably it is 0.01-10 mass% with respect to the composition whole quantity, More preferably, it is 0.1-5 mass%. When the content ratio of the component (C) is less than 0.01% by mass, the radical polymerization reaction rate (curing rate) of the obtained resin composition tends to be low, and photocuring tends to take a long time. On the other hand, when the content rate of a component (C) exceeds 10 mass%, an excess amount of a polymerization initiator may reduce the hardening characteristic of a resin composition.

Ingredient (D)
Component (D) used in the composition of the present invention is a radically polymerizable compound. Specifically, it is a compound having an ethylenically unsaturated bond (C = C), a monofunctional monomer having one ethylenically unsaturated bond in one molecule, and two or more ethylenically unsaturated bonds in one molecule. Mention may be made of polyfunctional monomers having a saturated bond.

  The monofunctional monomer and the polyfunctional monomer may each be used alone or in combination of two or more, or at least one monofunctional monomer and at least one polyfunctional monomer may be combined to constitute the component (D). it can.

  In the component (D), a polyfunctional monomer having 3 or more functional groups, that is, 3 or more ethylenically unsaturated bonds in one molecule is 60% by mass or more with the total amount of the component (D) being 100% by mass. It is preferably contained. A more preferable content ratio of the trifunctional or higher polyfunctional monomer is 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 100% by mass. When the content ratio of the trifunctional or higher polyfunctional monomer is 60% by mass or more, the radiation curability of the obtained resin composition tends to be further improved.

  Specific examples of the monofunctional monomer of component (D) include acrylamide, (meth) acryloylmorpholine, 7-amino-3,7-dimethyloctyl (meth) acrylate, isobutoxymethyl (meth) acrylamide, isobornyloxy Ethyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl diethylene glycol (meth) acrylate, t-octyl (meth) acrylamide, diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylamino Ethyl (meth) acrylate, lauryl (meth) acrylate, dicyclopentadiene (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl (meth) Acrylate, N, N-dimethyl (meth) acrylamide tetrachlorophenyl (meth) acrylate, 2-tetrachlorophenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, tetrabromophenyl (meth) acrylate, 2-tetrabromophenoxy Ethyl (meth) acrylate, 2-trichlorophenoxyethyl (meth) acrylate, tribromophenyl (meth) acrylate, 2-tribromophenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) ) Acrylate, vinylcaprolactam, N-vinylpyrrolidone, phenoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, pentachlorophenyl (meth) a Examples include compounds represented by relate, pentabromophenyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, bornyl (meth) acrylate, and methyltriethylenediglycol (meth) acrylate. Can do.

  Specific examples of the component (D) multifunctional monomer include ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, and tricyclodecane. Diyldimethylene 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, trimethylolpropane tri (meth) acrylate, ethylene oxide (hereinafter referred to as “EO”) modified trimethylolpropane tri (meth) acrylate, propylene oxide (hereinafter referred to as “EO”) ("PO")) Modified trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether end (meth) acrylic acid adduct, 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, caprolact Modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meth) acrylate EO-modified hydrogenated bisphenol A di (meth) acrylate, PO-modified hydrogenated bisphenol A di (meth) acrylate, EO-modified bisphenol F di (meth) acrylate, (meth) acrylate of phenol novolac polyglycidyl ether, and the like. it can.

  Among these, tri (meth) acrylate compounds, tetra (meth) acrylate compounds, penta (meth) acrylate compounds, hexa (meth) acrylate compounds and the like exemplified above that correspond to polyfunctional monomers having three or more functions are preferable. Among them, tris (acryloyloxyethyl) isocyanurate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditri Methylolpropane tetra (meth) acrylate is particularly preferred.

  As a commercial item of the monofunctional monomer of component (D), for example, Aronix M-101, M-102, M-111, M-113, M-117, M-152, TO-1210 (above, Toagosei ( KAYARAD TC-110S, R-564, R-128H (Nippon Kayaku Co., Ltd.), biscoat 192, biscoat 220, biscoat 2311HP, biscoat 2000, biscoat 2100, biscoat 2150, biscoat 8F, biscoat 17F (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

  Commercially available products of the component (D) polyfunctional monomer include, for example, SA1002 (manufactured by Mitsubishi Chemical Corporation), biscoat 195, biscoat 230, biscoat 260, biscoat 215, biscoat 310, biscoat 214HP, biscoat 295, Biscoat 300, Biscoat 360, Biscoat GPT, Biscoat 400, Biscoat 700, Biscoat 540, Biscoat 3000, Biscoat 3700 (manufactured by Osaka Organic Chemical Co., Ltd.), Kayarad R-526, HDDA, NPGDA, TPGDA, MANDA, R -551, R-712, R-604, R-684, PET-30, GPO-303, TMPTA, THE-330, DPHA, DPHA-2H, DPHA-2C, DPHA-2I, D-310, D-330 , DP A-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN-2475, T-1420, T-2020, T-2040, TPA-320, TPA-330, RP-1040, RP- 2040, R-011, R-300, R-205 (manufactured by Nippon Kayaku Co., Ltd.), Aronix M-210, M-220, M-233, M-240, M-215, M-305, M-309, M-310, M-315, M-325, M-400, M-6200, M-6400 (above, manufactured by Toagosei Co., Ltd.), light acrylate BP-4EA, BP-4PA, BP- 2EA, BP-2PA, DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.), New Frontier BPE-4, BR-42M, GX-8345 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), A F-400 (manufactured by Nippon Steel Chemical Co., Ltd.), lipoxy SP-1506, SP-1507, SP-1509, VR-77, SP-4010, SP-4060 (manufactured by Showa Polymer Co., Ltd.) ), NK ester A-BPE-4 (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like.

  Content of the component (D) in the composition of this invention becomes like this. Preferably it is 0.1-25 mass% with respect to the composition whole quantity, More preferably, it is 0.1-15 mass%. The addition of component (D) tends to improve the radiation curability of the resin composition. However, when the content exceeds 25% by mass, there is a problem that the bending durability of the film-like optical waveguide is lowered. is there.

Ingredient (E)
Component (E) used in the composition of the present invention is a polyether polyol compound. By adding the component (E), the radiation curability of the resin composition can be improved, and the mechanical properties (particularly the elastic modulus) of the cured product obtained by irradiating the resin composition with light can be improved. A film-like optical waveguide having good mechanical strength can be obtained.

  (E) The polyether polyol preferably has 3 or more hydroxyl groups in one molecule, and particularly preferably has 3 to 6 hydroxyl groups in one molecule. By using a polyether polyol having 3 or more hydroxyl groups in one molecule, a sufficient effect of improving radiation curability can be obtained, and the mechanical properties of the resulting cured film tend to be stable.

  (E) Specific examples of the polyether polyol include trivalent or higher polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, sorbitol, sucrose, and quadrol, ethylene oxide (EO), propylene oxide (PO), and butylene oxide. And polyether polyols obtained by modification with a cyclic ether compound such as tetrahydrofuran, specifically, EO-modified trimethylolpropane, PO-modified trimethylolpropane, tetrahydrofuran-modified trimethylolpropane, EO-modified glycerin, PO-modified glycerin, tetrahydrofuran-modified glycerin, EO-modified pentaerythritol, PO-modified pentaerythritol, tetrahydrofuran-modified pentaerythritol, EO-modified SO Bitoru, mention may be made of PO-modified sorbitol, EO modified sucrose, PO-modified sucrose, EO modified sucrose, EO modified Kuodoru like. Said polyether polyol can comprise a component (E) individually by 1 type or in combination of 2 or more types.

  (E) Commercially available polyether polyols include Sannix TP-400, Sannix GP-600, Sannix GP-1000, Sannix SP-750, Sannix GP-250, Sannix GP-400, Sannix GP-600 (above, manufactured by Sanyo Chemical Co., Ltd.), TMP-3Glycol, PNT-4 Glycol, EDA-P-4, EDA-P-8 (above, manufactured by Nippon Emulsifier Co., Ltd.), G-300, G -400, G-700, T-400, EDP-450, SP-600, SC-800 (above, manufactured by Asahi Denka Kogyo Co., Ltd.), SCP-400, SCP-1000, SP-1600 (above, Sakamoto Yakuhin) (Manufactured by Kogyo Co., Ltd.).

  The content of the component (E) in the composition of the present invention is preferably 1 to 35% by mass, more preferably 1 to 25% by mass, and particularly preferably 3 to 15% by mass with respect to the total amount of the composition. . When content of a component (E) is less than 1 mass%, sufficient radiation curability may not be obtained and mechanical strength may fall. On the other hand, when the content rate of a component (E) exceeds 35 mass%, the water absorption of the resin composition obtained increases and there exists a tendency for the mechanical strength of a film-form optical waveguide to fall.

Ingredient (F)
Component (F) used in the composition of the present invention is an elastomer particle having a number average particle size of 10 to 1,000 nm measured by electron microscopy. By adding a component (F), the bending durability of the hardened | cured material obtained by irradiating light to the composition of this invention can be improved.
The number average particle diameter of the component (F) is 10 to 1,000 nm, preferably 50 to 500 nm. If the number average particle size is less than 10 nm, the liquid viscosity of the composition increases, which may cause poor coating. When the number average particle diameter exceeds 1,000 nm, the effect of improving the bending durability may be reduced.

  (F) Specific examples of elastomer particles having a number average particle diameter of 10 to 1,000 nm include polybutadiene, polyisoprene, butadiene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / isoprene copolymer, ethylene / propylene. Copolymer, ethylene / α-olefin copolymer, ethylene / α-olefin / polyene copolymer, acrylic rubber, butadiene / (meth) acrylate copolymer, styrene / butadiene block copolymer, styrene / Examples thereof include elastomer particles containing isoprene block copolymer as a base component. Further, core / shell type particles may be used. Among the elastomer particles, polybutadiene, polyisoprene, styrene / butadiene copolymer, styrene / isoprene copolymer, butadiene / (meth) acrylic acid ester copolymer. In particular, core particles partially crosslinked with styrene / butadiene block copolymer, styrene / isoprene block copolymer, etc., elastomer particles coated with methyl methacrylate polymer, particles coated with methyl methacrylate / glycidyl methacrylate copolymer preferable.

Among the component (F), examples of commercially available core / shell type elastomer particles as described above include, for example, Resin Bond RKB (manufactured by Resin Chemical Co., Ltd.), Techno MBS-61, MBS-69 (and above, Technopolymer ( And the like).
Content of the component (F) in this invention becomes like this. Preferably it is 1-35 mass% with respect to the composition whole quantity, More preferably, it is 5-25 mass%, Most preferably, it is 10-20 mass%. When the content is less than 1% by mass, impact resistance and fracture toughness are reduced, and when the content exceeds 35% by mass, the liquid viscosity of the composition increases and the coating accuracy tends to decrease. is there.

In the photocurable resin composition of the present invention, in addition to the above-mentioned components (A) to (F), as long as the characteristics of the resin composition of the present invention are not impaired as necessary, for example, the component (B), Compounds having polymerizable reactive groups other than (D) and (E), and polymer resins (for example, epoxy resins, acrylic resins, polyamide resins, polyamideimide resins, polyurethane resins, polybutadiene resins, polychloroprene resins, polyethers) Resin, polyester resin, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based polymer, silicone-based polymer) and the like.
Furthermore, various additives as necessary, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, surfactants, colorants, Storage stabilizers, plasticizers, lubricants, fillers, inorganic particles, anti-aging agents, wettability improvers, antistatic agents and the like can be blended.
In order to prepare the photocurable resin composition, the above-described components may be mixed and stirred according to a conventional method.

  The composition of the present invention is charged with appropriate amounts of components (A) to (F) and other additives in a stirring vessel, and is usually 30 to 70 ° C., preferably 50 to 60 ° C., usually 1 to 6. It can be produced by stirring for a period of time, preferably 1-2 hours.

  The material for forming the optical waveguide (lower clad layer, core portion, upper clad layer) of the film-like optical waveguide of the present invention is an acrylic photocuring from the viewpoint of adhesion between the optical waveguide and the cured film layer. A functional resin composition is preferably used. When an optical waveguide is formed using an acrylic photocurable resin composition, good adhesiveness can be obtained without performing surface treatment on the contact surface with the cured film layer. Examples of the acrylic photocurable resin composition include OPSTAR PJ3074 and OPSTAR PJ3075 (manufactured by JSR Corporation).

Next, an example of the film-like optical waveguide of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing an example of a film-shaped optical waveguide with a cured film layer of the present invention.
FIG. 2 is a flowchart showing an example of a method for producing a film-shaped optical waveguide with a cured film layer of the present invention.
[Structure of film-shaped optical waveguide]
In FIG. 1, the film-shaped optical waveguide 24 includes a cured film layer 8, a lower cladding layer 10 formed by being laminated on the upper surface of the cured film layer 8, and a specific width formed on the upper surface of the lower cladding layer 10. The upper clad layer 20 formed on the lower clad layer 10 and the core portion 18, and the cured film layer 22 formed on the upper surface of the upper clad layer 20. . The core portion 18 is formed in the lower cladding layer 10 and the upper cladding layer 20.
The thicknesses of the lower cladding layer, the core portion, and the upper cladding layer are not particularly limited. For example, the thickness of the lower cladding layer is 1 to 200 μm, the thickness of the core portion is 3 to 200 μm, and the thickness of the upper cladding layer. Is determined to be 1 to 200 μm. Although the width | variety of a core part is not specifically limited, For example, it is 1-200 micrometers.
The refractive index of the core portion needs to be higher than any of the refractive indexes of the lower cladding layer and the upper cladding layer. For example, for light having a wavelength of 400 to 1,600 nm, the refractive index of the core portion is 1.420 to 1.650, the refractive indexes of the lower cladding layer and the upper cladding layer are 1.400 to 1.648, and The refractive index of the core portion is preferably at least 0.1% greater than the refractive index of any of the two cladding layers.

The cured film layer has high transparency.
The cured film layer is highly transparent, so that a light emitting element such as a surface emitting laser or a light receiving element such as a photodiode is joined to the lower surface of the film-shaped optical waveguide to form an interface for converting electrical / optical signals. In this case, the film-shaped optical waveguide can be seen through from above, and the position of the light-emitting element and the light-receiving element can be accurately aligned with the position of the core portion in the film-shaped optical waveguide.
Further, since the cured film layer has high transparency, a high transmittance can be expressed with respect to light in a wavelength region used for an optical signal, and the optical signal from the light emitting element is transmitted to the cured film layer and the cladding layer. The loss of light when passing through the core and reaching the core portion, and the loss of light when the optical signal from the core portion passes through the cladding layer and the cured film layer and reaches the light receiving element are extremely reduced. be able to.
Further, when the cured film layer has a thickness of 10 μm, it preferably has a transmittance of 80% or more, more preferably 90% or more with respect to light having a wavelength of 405 nm.
The thickness of the cured film layer is preferably 1 to 50 μm, more preferably 1 to 25 μm, and particularly preferably 1 to 15 μm.
The cured film layer may be formed so as to cover at least the entire lower surface of the lower clad layer and the upper surface of the upper clad layer.

[Method for producing film-shaped optical waveguide]
The manufacturing method of the film-like optical waveguide 24 of the present invention includes the step of forming the cured film layer 8, the step of forming the lower clad layer 10, the step of forming the core portion 18, and the step of forming the upper clad layer 20. And a step of forming the cured film layer 22. Among these steps, the step of forming the cured film layer 8 and the step of forming the cured film layer 22 are steps of irradiating and curing the above-described photocurable resin composition.
In addition, the photocurable resin composition for forming the cured film layer 8 and the photocurable resin composition for forming the cured film layer 22 are respectively referred to as a lower cured film layer composition and an upper cured film layer composition for convenience. Called. The photocurable resin composition for forming each part of the lower clad layer 10, the core portion 18 and the upper clad layer 20 constituting the optical waveguide has a lower layer composition, a core composition and an upper layer, respectively, for convenience. It is called a composition for use.
(1) Preparation of photocurable resin composition Each component composition of the composition for lower cured film layers and the composition for upper cured film layers is although it does not specifically limit, It is the same on economical and manufacturing management. It is preferable that it is a photocurable resin composition.
On the other hand, each component composition of the lower layer composition, the core composition, and the upper layer composition requires the optical waveguide to have a refractive index relationship between the lower cladding layer 10, the core portion 18 and the upper cladding layer 20. It is determined to satisfy the following conditions. Specifically, two or three kinds of photocurable resin compositions having a suitable difference in refractive index are prepared, and among these, a photocurable resin composition that gives a cured film having the highest refractive index. Is used as a core composition, and other photocurable resin compositions are used as a lower layer composition and an upper layer composition.
The lower layer composition and the upper layer composition are preferably the same photocurable resin composition in terms of economy and production control.

(2) Preparation of Substrate As shown in FIG. 2A, a substrate 2 having a flat surface is prepared. Although it does not specifically limit as a kind of this board | substrate 2, For example, a silicon substrate, a glass substrate, etc. can be used.
(3) Forming process of cured film layer In this process, the cured film layer 8 is formed on the upper surface of the substrate 2. Specifically, as shown in FIG. 2B, the lower cured film layer composition is applied to the surface of the substrate 2 and dried or prebaked to form the cured film layer thin film 4. The cured film layer thin film 4 is irradiated with light 6 and cured to form a cured film layer 8 which is a cured body (see (c) and (d) in FIG. 2). In addition, in the formation process of the cured film layer 8, it is preferable to irradiate the whole surface of a thin film and to harden the whole.
As a coating method of the composition for a cured film layer, any of spin coating, dipping, spraying, bar coating, roll coating, curtain coating, gravure printing, silk screen, ink jet, etc. Can be used. Among these, since the thin film for cured film layers of uniform thickness is obtained, it is preferable to employ | adopt a spin coat method.

The irradiation amount of light when forming the cured film layer 8 is not particularly limited, but light having a wavelength of 200 to 450 nm and an illuminance of 1 to 500 mW / cm ² is irradiated with an irradiation amount of 10 to 5,000 mJ / cm. It is preferable to perform exposure by irradiating so as to be ² .
Visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, and the like can be used as the type of light to be irradiated, and ultraviolet rays are particularly preferable. As the light irradiation device, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, an excimer lamp, or the like is preferably used.
Moreover, at the time of exposure, curability can be improved by making exposure atmosphere into nitrogen stream as needed.
Further, after the exposure, a heat treatment (post-bake) can be further performed. Although this heating condition changes with component composition etc. of a photocurable resin composition, it is 30-250 degreeC normally, Preferably it is 50-200 degreeC, More preferably, it is 100-150 degreeC, for example, for 5 minutes-72 hours of heating. Time can be taken. By performing the heat treatment (post-bake), the entire surface of the coating film can be sufficiently cured.
In addition, the coating method of the composition in the formation process of the cured film layer 8, the amount of light irradiation, the type, the light (ultraviolet) irradiation device, the pre-bake and post-bake conditions, and the like are described below. The same applies to.

(4) Step of forming lower clad layer This is a step of forming the lower clad layer 10 on the upper surface of the cured film layer 8. Specifically, as shown in FIG. 2 (e), the lower layer composition is applied to the upper surface of the cured film layer 8, and dried or prebaked to form the lower layer thin film. The lower layer thin film is irradiated with light and cured to form a lower cladding layer 10 that is a cured body. In the step of forming the lower cladding layer 10, it is preferable to irradiate the entire surface of the thin film with light and harden the whole.
Here, as a coating method of the composition for the lower layer, any of spin coating method, dipping method, spray method, bar coating method, roll coating method, curtain coating method, gravure printing method, silk screen method, ink jet method, etc. The method can be used. Among these, since a thin film for a lower layer having a uniform thickness can be obtained, it is preferable to employ a spin coating method.
In addition, in order to make the rheological properties of the lower layer composition suitable for the coating method, the lower layer composition requires various leveling agents, thixotropic agents, fillers, organic solvents, surfactants, etc. It is preferable to mix according to this.
Moreover, it is preferable to pre-bake the thin film for lower layers which consists of a composition for lower layers at the temperature of 50-200 degreeC for the purpose of removing an organic solvent etc. after application | coating.
The coating method in the lower clad layer forming step, improvement of rheological characteristics, and the like are the same in the core step forming step and the upper clad layer forming step, which will be described later.

The amount of light irradiation when forming the lower clad layer is not particularly limited, but light having a wavelength of 200 to 450 nm and an illuminance of 1 to 500 mW / cm ² is irradiated in an amount of 10 to 5,000 mJ / cm ^2. It is preferable that the exposure is performed by irradiation.
Visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, and the like can be used as the type of light to be irradiated, and ultraviolet rays are particularly preferable. As the light irradiation device, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, an excimer lamp, or the like is preferably used.
Moreover, it is preferable to perform a heat treatment (post-bake) after the exposure. Although this heating condition changes with component composition etc. of a photocurable resin composition, it is 30-250 degreeC normally, Preferably it is 50-200 degreeC, More preferably, it is 100-150 degreeC, for example, for 5 minutes-72 hours of heating. Time can be taken. By performing the heat treatment (post-bake), the entire surface of the coating film can be sufficiently cured.
The light irradiation amount, type, and light (ultraviolet) irradiation device in the lower clad layer forming step are the same in the core portion forming step and the upper clad layer forming step, which will be described later.

(5) Core Part Formation Step Next, as shown in FIG. 2 (f), the core composition is applied to the upper surface of the lower cladding layer 10 and dried or prebaked to form the core thin film 12. To do. Thereafter, as shown in FIG. 2 (f), irradiation (exposure) of light 16 is performed on the upper surface of the core thin film 12 according to a predetermined pattern, for example, through a photomask 14 having a predetermined line pattern. Do. As a result, only the portion irradiated with light in the core thin film 12 is cured, so that other uncured portions are developed and removed, as shown in FIG. On the lower clad layer 10, a core portion 18 made of a patterned cured film can be formed.
The details of the development processing in this step are as follows.
The development process is carried out in accordance with a predetermined pattern, and for the thin film selectively cured, using the difference in solubility between the cured portion and the uncured portion, only the uncured portion is developed using a developer. The removal is performed. That is, after pattern exposure, the uncured portion is removed and the cured portion is left, resulting in the formation of the core portion.

An organic solvent can be used as the developer used in the development process. Examples of the organic solvent include acetone, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol monomethyl ether acetate, methyl amyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, and the like.
The development time is usually 30 to 600 seconds. As a developing method, a known method such as a liquid piling method, a dipping method, or a shower developing method can be employed. After the development, the organic solvent is removed by air drying as it is, and a patterned thin film is formed.
After the formation of the patterned thin film (patterning portion), the patterning portion is heat-treated (post-baked). Although this heating condition changes with component composition etc. of a photocurable resin composition, it is 30-250 degreeC normally, Preferably it is 50-200 degreeC, More preferably, it is 100-150 degreeC, for example, for 5 minutes-10 minutes. What is necessary is just to set it as the heating time of time. By performing the heat treatment (post-bake), the entire surface of the coating film can be sufficiently cured.

In this step, the method of irradiating light according to a predetermined pattern is not limited to the method using the photomask 14 composed of the light transmitting portion and the non-transmitting portion, and for example, any of the following methods a to c May be adopted.
a. A method using electro-optical means for forming a mask image composed of a light transmitting region and a light non-transmitting region in accordance with a predetermined pattern using the same principle as that of a liquid crystal display device.
b. A method of irradiating light through an optical fiber corresponding to a predetermined pattern in the light guide member using a light guide member formed by bundling a large number of optical fibers.
c. A method of irradiating a photocurable resin composition while scanning a laser beam or convergent light obtained by a condensing optical system such as a lens or a mirror.

(6) Formation process of upper clad layer The upper layer composition is applied to the upper surfaces of the core portion 18 and the lower clad layer 10, and dried or prebaked to form an upper layer thin film. When this upper thin film is cured by irradiation with light, an upper clad layer 20 is formed as shown in (i) of FIG.
Further, the entire surface of the coating film can be sufficiently cured by subjecting the upper clad layer 20 to heat treatment (post-baking). This heating condition is usually 30 to 250 ° C., preferably 50 to 200 ° C., more preferably 100 to 150 ° C., for example, a heating time of 5 minutes to 72 hours.

(7) Forming process of cured film layer In this process, the cured film layer 22 is formed on the upper surface of the upper clad layer 20. Specifically, as shown in FIG. 2 (j), the upper cured film layer composition is applied to the upper surface of the upper clad layer, and dried or prebaked to form a cured film layer thin film. The cured film layer 22 which is a cured body is formed by irradiating light to the film layer thin film and curing it. In addition, in the formation process of the cured film layer 22, it is preferable to irradiate the whole surface of a thin film and to harden the whole. After the exposure, a heat treatment (post-bake) may be further performed.
As described above, when the cured film layer 22 is formed, the method for applying the composition for the cured film layer, the pre-bake conditions, the amount and type of light irradiation, the light irradiation device, the post-bake conditions, etc. This is the same as the process for forming the cured film layer 8 described above.

(8) Peeling of the substrate When the cured product produced in the above steps (1) to (7) is peeled from the substrate 2, a film-like optical waveguide is obtained (see (k) in FIG. 2).
Examples of the peeling method include a method of immersing an optical waveguide produced on a silicon substrate in warm water or hydrofluoric acid.

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

[1. Preparation of photocurable resin composition for cured film layer]
According to the formulation shown in Table 1, each component was charged into a stirring vessel and stirred at 60 ° C. for 3 hours to obtain photocurable resin compositions J-1 to J-3 for a cured film layer. The formulation of Table 1 is shown in mass%.

[2. Preparation of photocurable resin composition for optical waveguide]
Opstar PJ3075 (manufactured by JSR) was used as a photocurable resin composition for forming the lower and upper clad layers. Opstar PJ3074 (manufactured by JSR Corporation) was used as a photocurable resin composition for core formation.

[3. Formation of film-like optical waveguide]
[Example 1]
(1) Formation of cured film layer The photocurable resin composition J-1 for cured film layer was applied to the upper surface of the silicon substrate with a spin coater, and then applied to the coating film made of the photocurable resin composition J-1. Ultraviolet rays having a wavelength of 365 nm and an illuminance of 20 mW / cm ² were irradiated for 100 seconds to be photocured to obtain a cured film layer having a thickness of 10 μm.
(2) Formation of lower clad layer A photocurable resin composition for forming a clad layer (OPSTAR PJ3075; manufactured by JSR) was applied to the upper surface of the cured film layer with a spin coater, and was heated at 100 ° C. for 10 minutes using a hot plate. Pre-baked with conditions. Next, the coating film made of the photocurable resin composition for forming a cladding layer was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 20 mW / cm ² for 75 seconds to be photocured. The cured film was post-baked at 150 ° C. for 1 hour to form a lower cladding layer having a thickness of 10 μm.
(3) Formation of core portion A photocurable resin composition for core formation (OPSTAR PJ3074; manufactured by JSR) was applied onto the lower clad layer with a spin coater and prebaked at 100 ° C for 10 minutes. Next, an ultraviolet ray having a wavelength of 365 nm and an illuminance of 20 mW / cm ² is irradiated for 75 seconds through a photomask having a line pattern having a width of 50 μm to a 50 μm-thick coating film made of the core-forming photocurable resin composition. And photocured. And the board | substrate which has the hardened coating film was immersed in the developing solution which consists of acetone, and the unexposed part of the coating film was dissolved. Thereafter, post-baking was performed at 150 ° C. for 1 hour to form a core portion having a line pattern having a width of 50 μm.

(4) Formation of upper clad layer On the upper surface of the lower clad layer having a core portion, a photocurable resin composition for forming a clad layer (OPSTAR PJ3075; manufactured by JSR) was applied with a spin coater, and 100 ° C. using a hot plate. Pre-baking was performed for 10 minutes. Thereafter, the coating film made of the photocurable resin composition for forming the clad layer is photocured by irradiating with ultraviolet rays having a wavelength of 365 nm and an illuminance of 20 mW / cm ² for 75 seconds, and the thickness from the upper surface of the core portion is 10 μm. A clad layer was formed.
(5) Formation of cured film layer The photocurable resin composition J-1 for cured film layer is applied to the upper surface of the upper clad layer with a spin coater, and then applied to the coating film made of the photocurable resin composition J-1. The film was cured by irradiating with ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW / cm ² for 100 seconds to obtain a cured film layer having a thickness of 10 μm.
(6) Peeling of substrate The cured product formed in the steps (1) to (5) above is peeled from the substrate, and the cured film layer, the lower cladding layer, the core portion, the upper cladding layer, and the cured film layer are arranged in this order. A laminated optical waveguide was obtained.

[Example 2, Comparative Examples 1 and 2]
A film-like optical waveguide was formed in the same manner as in Example 1 except that the photocurable resin composition for forming the cured film layer was changed as shown in Table 1.

[4. Evaluation of film-like optical waveguide]
Film-shaped optical waveguides (Examples 1 and 2 and Comparative Examples 1 and 2) were evaluated as follows.
[Bending durability]
A bending test was performed on the produced film-shaped optical waveguide (width 1 cm, length 10 cm, thickness 90 μm) in an environment of a temperature of 23 ° C. and a humidity of 50%. The test conditions are a bending radius of 2 mm, a bending angle of ± 135 °, a bending speed of 100 times / minute, and a load of 100 g. The number of bendings was bent from the initial 0 degree position (the film-shaped optical waveguide was in a horizontal state) to a +135 degree position, and then bent again to a -135 degree position via the 0 degree position. Thereafter, the operation of returning to the 0 degree position is defined as one time. Measure the number of times until the film-shaped optical waveguide breaks, “○” if no break or crack occurs even if the number of bending exceeds 100,000, and break or crack occurs when the number of bending is less than 100,000 The case where it does is made "x".
[transparency]
The transparency of the cured film layer (thickness: 10 μm) was measured with a spectrophotometer. The case where the transmittance of light at a wavelength of 405 nm was 80% or more was “◯”, and the case where it was less than 80% was “x”.
The results are shown in Table 2.

  From Table 2, it can be seen that the film-like optical waveguides of the present invention (Examples 1 and 2) are excellent in bending durability. Moreover, the cured film layer of the film-form optical waveguide of this invention is excellent in transparency. On the other hand, it turns out that the comparative example 1 which does not contain a component (A) and a component (B), and the comparative example 2 which does not have a cured film layer are inferior to bending durability.

It is sectional drawing which shows typically an example of the film-form optical waveguide with a cured film layer of this invention. It is a flowchart which shows an example of the manufacturing method of the film-form optical waveguide with a cured film layer of this invention.

Explanation of symbols

2 substrate 4 thin film for cured film layer 6 light 8 cured film layer 10 lower clad layer 12 thin film for core 14 photomask 16 light 18 core portion 20 upper clad layer 22 cured film layer 24 film-like optical waveguide

Claims (4)

A film-shaped optical waveguide having a lower clad layer, a core portion, and an upper clad layer, wherein the following components (A) to (D) and A film-shaped optical waveguide comprising a cured film layer obtained by photocuring a photocurable resin composition containing (F).
(A) Photoacid generator (B) Cationic polymerizable compound (C) Radical polymerization initiator (D) Radical polymerizable compound (F) Elastomer having a number average particle size measured by electron microscopy of 10 to 1,000 nm particle The film-form optical waveguide of Claim 1 whose content rate of the said components (A)-(D) and (F) with respect to the said photocurable resin composition whole quantity is as follows.
(A) Photoacid generator 0.1-10 mass%
(B) Cation polymerizable compound 15-85 mass%
(C) Radical polymerization initiator 0.01 to 10% by mass
(D) Radical polymerizable compound 0.1-25 mass%
(F) Elastomer particles having a number average particle diameter of 10 to 1,000 nm measured by electron microscopy 1 to 35% by mass   The film-form optical waveguide of Claim 1 or 2 in which the said photocurable resin composition contains (E) polyether polyol by the content rate of 1-35 mass% of this composition whole quantity.   The film-shaped optical waveguide according to claim 1, wherein the cured film layer has a transmittance of 80% or more with respect to light having a wavelength of 405 nm when the thickness is 10 μm.

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