Photosensitive resin composition set

Abstract

The present invention addresses the problem of providing a photosensitive resin composition set and the like capable of producing an optical waveguide having excellent developability and flame retardancy, a low shrinkage rate, and small optical transmission loss. The solution is that the photosensitive resin composition set comprises a resin composition for a core and a resin composition for a coating, the core resin composition and the coating resin composition each contain (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from the group consisting of phosphate ester compounds and phosphazene compounds. When the content (mass%) of the component (E) in the coating resin composition is represented by Eclad and the content (mass%) of the component (E) in the core resin composition is represented by Ecore, Eclad-Ecore satisfies 0.6 to 12 inclusive, and the content (mass%) of the component (E) in the coating resin composition is represented by Eclad and the content (mass%) of the component (E) in the core resin composition is represented by Ecore, the content (mass%) of the component (E) in the coating resin composition is represented by 100 mass%. The content (mass%) of the (E) component in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass%.

Description

Technical Field

[0001] The present invention relates to a photosensitive resin composition set and further to a photosensitive resin sheet set, the photosensitive resin composition set, an optical waveguide, a method for producing the optical waveguide, an optoelectronic hybrid substrate, and an optoelectronic hybrid manufacturing method. Background Art

[0002] Due to the advancement of technologies such as 5G communications, autonomous driving, IoT, artificial intelligence, and big data, the demand for ultra-high-speed and high-capacity communications is increasing. The semiconductor packaging that supports it used to cope with high-speed communications by circulating high-frequency currents. However, in recent years, the issues of noise generation, communication loss, and heat generation caused by high-speed communications have become increasingly prominent. In order to solve these problems, in recent years, optical circuits have been actively installed on power wiring substrates to achieve energy saving, low latency, and high-speed communication (Patent Documents 1 and 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-211540

[0006] Patent Document 2: Japanese Patent No. 5771978 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In particular, research on the introduction of silicon photonics is actively being conducted in data centers that require high-speed transmission. Silicon photonics is highly compatible with conventional LSI manufacturing processes. Therefore, by making full use of silicon photonics, it is expected that nano-sized fine-line waveguides can be formed at low cost based on the technology developed in electronic circuit integration technology.

[0009] For example, it is expected that an optical integrated circuit can be formed on a chip using a fine waveguide through silicon photonics. In the case of manufacturing an optoelectronic hybrid substrate equipped with the chip, in order to take the signal light from the fine waveguide in the chip to the outside of the chip and connect it to the wiring between the chips, it is required to set an optical waveguide in the optoelectronic hybrid substrate. From the viewpoint of efficiently forming a fine optical waveguide, it is expected to form an optical waveguide using a cured product of a photosensitive resin composition. In addition, for the optoelectronic hybrid substrate, including flame retardancy, etc., the same reliability as that of the printed substrate is required, so it is expected that there will be no major changes in light transmission loss, and it is also expected to tolerate the characteristics of the manufacturing process of the printed substrate as much as possible.

[0010] In addition, when forming a core and a cladding with a cured product of a photosensitive resin composition, it is necessary to change the composition and ratio of the resin components contained in the aforementioned photosensitive resin composition in order to adjust the refractive index between the core and the cladding. However, this may reduce the developability or change the shrinkage rate of the photosensitive resin composition before and after curing, and sometimes increase the light transmission loss.

[0011] The subject of the present invention is proposed in view of the above-mentioned problems, and its purpose is to provide a photosensitive resin composition set capable of producing an optical waveguide with excellent developability and flame retardancy, low shrinkage and small light transmission loss; a photosensitive resin sheet set; an optical waveguide; a method for producing an optical waveguide; an optoelectronic hybrid substrate; and a method for producing an optoelectronic hybrid substrate.

[0012] Solutions to Solve Problems

[0013] The present inventors have conducted intensive research and found that the core resin composition and the coating resin composition each contain (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, (D) a photopolymerization initiator and (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds, and that the content of the component (E) is adjusted so that the contents of the component (E) contained in the core resin composition and the coating resin composition satisfy a prescribed relationship, thereby solving the above-mentioned problems and completing the present invention.

[0014] That is, the present invention includes the following contents.

[0015] [1] A photosensitive resin composition set comprising a core resin composition and a coating resin composition, wherein:

[0016] The core resin composition and the covering resin composition each contain:

[0017] (A) carboxyl-containing resins,

[0018] (B) Epoxy resin,

[0019] (C) Photocurable resin,

[0020] (D) a photopolymerization initiator, and

[0021] (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds,

[0022] The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E coreSatisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

[0023] [2] The photosensitive resin composition set according to [1], wherein the phosphate ester compound in the component (E) is any one of a compound represented by the following formula (E-1) and a compound represented by the following formula (E-2),

[0024] [Chemical formula 1]

[0025]

[0026] In formula (E-1), R 1 ~R 20 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and W 1 represents a group represented by formula (E-1a) or a group represented by formula (E-1b),

[0027] In formula (E-1b), R represents an oxygen atom or a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent,

[0028] In formula (E-2), R 21 ~R 28 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and R 29 It represents a (meth)acryloyl group, an oxygen atom, a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or a monovalent group consisting of a combination thereof.

[0029] [3] The photosensitive resin composition set according to [1] or [2], wherein the phosphazene compound in the component (E) is a compound represented by the following formula (E-3):

[0030] [Chemical formula 2]

[0031]

[0032] (In formula (E-3), R 31 and R 32 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, n represents an integer of 3 to 25, and m1 and m2 each independently represent an integer of 0 to 5. )

[0033] [4] The photosensitive resin composition set according to any one of [1] to [3], wherein the content of phosphorus atoms in the core resin composition is 0.01% by mass or more and 10% by mass or less when the nonvolatile component of the core resin composition is 100% by mass.

[0034] [5] The photosensitive resin composition set according to any one of [1] to [4], wherein the content of phosphorus atoms in the coating resin composition is 0.01% by mass or more and 10% by mass or less when the nonvolatile component of the coating resin composition is 100% by mass.

[0035] [6] The photosensitive resin composition set according to any one of [1] to [5], wherein the component (A) comprises at least one of an aralkyl type resin, a naphthol aralkyl type resin, and a Cardo type resin.

[0036] [7] The photosensitive resin composition set according to any one of [1] to [6], wherein the content of the component (A) is A core , the content of component (B) is set to B core When A core / B core The content of the component (A) is 0.3 or more and 5 or less, the content of the component (B) is 100% by mass of the nonvolatile component of the core resin composition, and the content of the component (A) is 100% by mass of the nonvolatile component of the core resin composition.

[0037] [8] The photosensitive resin composition set according to any one of [1] to [7], wherein the content of the component (A) is A core , the content of component (C) is set to C core When A core / C core The content of the component (A) is 0.1 to 3, the content of the component (C) is 100% by mass of the nonvolatile component of the core resin composition, and the content of the component (A) is 100% by mass of the nonvolatile component of the core resin composition.

[0038] [9] The photosensitive resin composition set according to any one of [1] to [8], wherein the content of the component (A) is A clad , the content of component (B) is set to B clad When A clad / B clad The content of the component (A) is 0.3 or more and 5 or less, the content of the component (B) is 100% by mass of the nonvolatile component of the coating resin composition.

[0039]

[10] The photosensitive resin composition set according to any one of [1] to [9], wherein the content of the component (A) is A clad , the content of component (C) is set to C clad When A clad / C clad The content of the component (A) is 0.1 to 3, the content of the component (C) is 100% by mass of the nonvolatile component of the coating resin composition.

[0040]

[11] The photosensitive resin composition set according to any one of [1] to

[10] , which is a photosensitive resin composition set for producing an optical waveguide.

[0041]

[12] The photosensitive resin composition set according to any one of [1] to

[11] , which is a photosensitive resin composition set for producing an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm.

[0042]

[13] The photosensitive resin composition set according to any one of [1] to

[12] , which is a photosensitive resin composition set for producing a single-mode optical waveguide.

[0043]

[14] A photosensitive resin sheet set comprising a core resin sheet and a covering resin sheet, wherein:

[0044] The core resin sheet comprises a resin composition layer comprising the core resin composition in the photosensitive resin composition set described in any one of [1] to

[13] .

[0045] The coating resin sheet includes a resin composition layer containing the coating resin composition in the photosensitive resin composition set according to any one of [1] to

[13] .

[0046]

[15] An optical waveguide comprising a core layer and a cladding layer, wherein:

[0047] The core layer comprises a cured product of a core resin composition, wherein the core resin composition comprises:

[0048] (A) carboxyl-containing resins,

[0049] (B) Epoxy resin,

[0050] (C) Photocurable resin,

[0051] (D) a photopolymerization initiator, and

[0052] (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds,

[0053] The coating layer comprises a cured product of a coating resin composition, wherein the coating resin composition comprises:

[0054] (A) carboxyl-containing resins,

[0055] (B) Epoxy resin,

[0056] (C) Photocurable resin,

[0057] (D) a photopolymerization initiator, and

[0058] (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds,

[0059] The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

[0060]

[16] An optoelectronic hybrid substrate comprising the optical waveguide described in

[15] .

[0061]

[17] A method for manufacturing an optical waveguide, comprising:

[0062] a step of forming a first composition layer including a coating resin composition,

[0063] a step of curing the first composition layer,

[0064] forming a second composition layer including a core resin composition on the first composition layer,

[0065] a step of subjecting the second composition layer to an exposure treatment,

[0066] a step of developing the second composition layer,

[0067] a step of curing the second composition layer,

[0068] forming a third composition layer comprising a coating resin composition on the second composition layer, and

[0069] a step of curing the third composition layer,

[0070] The core resin composition and the covering resin composition each contain:

[0071] (A) carboxyl-containing resins,

[0072] (B) Epoxy resin,

[0073] (C) Photocurable resin,

[0074] (D) a photopolymerization initiator, and

[0075] (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds,

[0076] The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

[0077]

[18] A method for manufacturing an optoelectronic hybrid substrate, comprising:

[0078] a step of forming a first composition layer including a coating resin composition,

[0079] a step of curing the first composition layer,

[0080] forming a second composition layer including a core resin composition on the first composition layer,

[0081] a step of subjecting the second composition layer to an exposure treatment,

[0082] a step of developing the second composition layer,

[0083] a step of curing the second composition layer,

[0084] forming a third composition layer comprising a coating resin composition on the second composition layer, and

[0085] a step of curing the third composition layer,

[0086] The core resin composition and the covering resin composition each contain:

[0087] (A) carboxyl-containing resins,

[0088] (B) Epoxy resin,

[0089] (C) Photocurable resin,

[0090] (D) a photopolymerization initiator, and

[0091] (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds,

[0092] The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

[0093] Effects of the Invention

[0094] According to the present invention, there can be provided a photosensitive resin composition set capable of producing an optical waveguide having excellent developability and flame retardancy, low shrinkage, and small light transmission loss; a photosensitive resin sheet set; an optical waveguide; a method for producing an optical waveguide; an optoelectronic hybrid substrate; and a method for producing an optoelectronic hybrid substrate.

[0095] Brief description of the attached figure

[0096] Figure 1 It is a perspective view schematically showing an optical waveguide according to one embodiment of the present invention.

[0097] Figure 2 This is a schematic cross-sectional view for explaining step (I) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0098] Figure 3 This is a schematic cross-sectional view for explaining step (II) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0099] Figure 4 This is a schematic cross-sectional view for explaining step (III) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0100] Figure 5This is a schematic cross-sectional view for explaining step (IV) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0101] Figure 6 This is a schematic cross-sectional view for explaining step (V) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0102] Figure 7 This is a schematic cross-sectional view for explaining step (VI) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0103] Figure 8 This is a schematic cross-sectional view for explaining step (VII) of the method for producing an optical waveguide according to one embodiment of the present invention.

[0104] Fig. 9 This is a schematic cross-sectional view for explaining step (VIII) of the method for producing an optical waveguide according to one embodiment of the present invention. DETAILED DESCRIPTION

[0105] Hereinafter, the photosensitive resin composition set, the photosensitive resin sheet set, the optical waveguide using the same, the method for producing the optical waveguide, the optoelectronic hybrid substrate, and the method for producing the optoelectronic hybrid substrate of the present invention will be described in detail.

[0106] [Photosensitive resin composition set]

[0107] The photosensitive resin composition set of the present invention includes a core resin composition and a coating resin composition. The core resin composition can be suitably used as a photosensitive resin composition for forming a core layer of an optical waveguide, and the coating resin composition can be suitably used as a photosensitive resin composition for forming a coating layer of an optical waveguide. The photosensitive resin composition set can be used for the production of an optical waveguide having a core layer including a cured product of the core resin composition and a coating layer including a cured product of the coating resin composition.

[0108] The core resin composition and the coating resin composition in the present invention each contain (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate esters and phosphazenes, and the content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E coreSatisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile components of the coating resin composition are set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile components of the core resin composition are set to 100 mass %. According to such a photosensitive resin composition set, an optical waveguide with excellent flame retardancy and small light transmission loss can be manufactured. In addition, the change rate of light transmission loss before and after the high temperature placement test (HTS test) is usually small. In addition, the core and coating resin compositions are photosensitive resin compositions, and therefore have excellent developability.

[0109] As described above, the core and covering resin compositions each contain (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate esters and phosphazenes, and in these resin compositions, the types of components and / or their blending ratios are different, so that E clad -E core Be 0.6 or more and 12 or less. The core and coating resin compositions may each contain optional components such as (F) a curing accelerator, (G) a solvent, and (H) other additives as needed. Hereinafter, each component contained in the core and coating resin compositions will be described in detail. Hereinafter, the core resin composition and the coating resin composition are sometimes referred to as "resin composition" together.

[0110] <(A) Carboxyl group-containing resin>

[0111] The resin composition contains a carboxyl group-containing resin as the component (A). The resin composition contains the component (A), so that the resolution can be improved.

[0112] As component (A), a compound having a carboxyl group and capable of alkali development can be used. As such a compound, a resin having both a carboxyl group and an ethylenically unsaturated group in one molecule is preferred. That is, component (A) is preferably a resin containing an ethylenically unsaturated group and a carboxyl group.

[0113] The ethylenically unsaturated group has a carbon-carbon double bond, and examples thereof include vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadiimide, and (meth)acryloyl. From the viewpoint of reactivity in photoradical polymerization, (meth)acryloyl is preferred. "(Meth)acryloyl" includes methacryloyl, acryloyl, and combinations thereof. When component (A) contains an ethylenically unsaturated group, photoradical polymerization can be performed. The number of ethylenically unsaturated groups per molecule of component (A) may be 1 or may be 2 or more. Furthermore, when component (A) contains 2 or more ethylenically unsaturated groups per molecule, those ethylenically unsaturated groups may be the same or different.

[0114] In addition, since component (A) contains a carboxyl group, the resin composition containing component (A) exhibits solubility in an alkaline solution (for example, a 1% by mass sodium carbonate aqueous solution as an alkaline developer). The number of carboxyl groups per molecule of component (A) may be 1 or 2 or more.

[0115] One embodiment of the component (A) is an acid-modified epoxy (meth)acrylate resin.

[0116] The acid-modified epoxy (meth)acrylate resin has a (meth)acryloyl group, and therefore, in one embodiment, can be photo-radical polymerized. The number of (meth)acryloyl groups per molecule of the acid-modified epoxy (meth)acrylate resin may be one, or may be two or more.

[0117] The acid-modified epoxy (meth)acrylate resin is preferably a resin having both a (meth)acryloyl group and a carboxyl group, capable of photoradical polymerization, and capable of alkali development.

[0118] The acid-modified epoxy (meth)acrylate resin can be produced by acid-modifying the epoxy (meth)acrylate resin by a known method. The epoxy (meth)acrylate resin can be produced, for example, by reacting an epoxy resin with acrylic acid or methacrylic acid.

[0119] The epoxy resin used for producing the epoxy (meth)acrylate resin is not particularly limited as long as it is a compound having an epoxy group in the molecule, and examples thereof include bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol F epoxy resin modified to have a trifunctional or higher functional bisphenol F epoxy resin by reacting bisphenol F epoxy resin with epichlorohydrin; biphenol epoxy resin, tetramethylbiphenol; phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, alkylphenol novolac epoxy resins and other novolac epoxy resins; fluorinated epoxy resins such as bisphenol AF epoxy resins and perfluoroalkyl epoxy resins; naphthalene epoxy resins, dihydroxynaphthalene epoxy resins, polyhydroxybinaphthyl epoxy resins, naphthol epoxy resins, naphthol aralkyl epoxy resins, binaphthol epoxy resins, naphthylene ether epoxy resins Resins: naphthol novolac epoxy resins, naphthalene-type epoxy resins obtained by condensation reaction of polyhydroxynaphthalene and aldehydes, etc., epoxy resins having a naphthalene skeleton (epoxy resins containing a naphthalene skeleton); aralkyl-type epoxy resins; bixylenol-type epoxy resins; dicyclopentadiene-type epoxy resins; trisphenol-type epoxy resins; tert-butyl-catechol-type epoxy resins; anthracene-type epoxy resins and other epoxy resins containing a condensed ring skeleton; glycidylamine-type epoxy resins; glycidylester-type epoxy resins; biphenyl-type epoxy resins Ester; linear aliphatic epoxy resin; epoxy resin with butadiene structure; alicyclic epoxy resin; heterocyclic epoxy resin; epoxy resin containing spiro ring; cyclohexanedimethanol type epoxy resin; trimethylol type epoxy resin; tetraphenylethane type epoxy resin; (meth) acrylate polyglycidyl ester, copolymer of methacrylate glycidyl and acrylate, etc. acrylic resin containing glycidyl group; fluorene type epoxy resin; halogenated epoxy resin; epoxy resin with Cardo structure, etc.

[0120] The epoxy resin used to manufacture the epoxy (meth) acrylate resin is preferably an epoxy resin containing an aromatic skeleton from the viewpoint of significantly obtaining the effect of the present invention. Here, the aromatic skeleton is a concept that also includes polycyclic aromatics and aromatic heterocycles. Among them, the epoxy resin used to manufacture the epoxy (meth) acrylate resin is preferably any one of an aralkyl epoxy resin, a naphthol aralkyl epoxy resin, and an epoxy resin having a Cardo structure, and is more preferably a naphthol aralkyl epoxy resin. The Cardo structure represents a structure in which two aromatic rings are bonded to a carbon atom inside the ring.

[0121] In one embodiment, the acid-modified epoxy (meth)acrylate resin preferably includes an acid-modified epoxy (meth)acrylate resin having a skeleton selected from an aralkyl skeleton, a naphthol aralkyl skeleton and a Cardo skeleton, and particularly preferably includes an acid-modified epoxy (meth)acrylate resin having a naphthol aralkyl skeleton.

[0122] In one embodiment, the acid-modified epoxy (meth)acrylate resin preferably includes a resin selected from an acid-modified epoxy (meth)acrylate resin obtained by esterifying the hydroxyl group of an epoxy (meth)acrylate resin (hereinafter referred to as "ester-type acid-modified epoxy (meth)acrylate resin") and an acid-modified epoxy (meth)acrylate resin obtained by urethane-modifying the hydroxyl group of an epoxy (meth)acrylate resin (hereinafter referred to as "urethane-type acid-modified epoxy (meth)acrylate resin"), and particularly preferably includes an ester-type acid-modified epoxy (meth)acrylate resin.

[0123] The ester type acid-modified epoxy (meth)acrylate resin can be produced by, for example, reacting an epoxy (meth)acrylate resin with an acid anhydride. The ester type acid-modified epoxy (meth)acrylate resin may be used alone or in combination of two or more.

[0124] Examples of the acid anhydride include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride, and any one of these may be used alone or two or more thereof may be used in combination. Among these, succinic anhydride and tetrahydrophthalic anhydride are preferred, and tetrahydrophthalic anhydride is more preferred.

[0125] The ester-type acid-modified epoxy (meth)acrylate resin preferably includes a resin selected from an ester-type acid-modified epoxy (meth)acrylate resin containing a cresol novolac skeleton, an ester-type acid-modified epoxy (meth)acrylate resin containing a bisphenol A skeleton, an ester-type acid-modified epoxy (meth)acrylate resin containing a bisphenol F skeleton, an acid-ester-modified epoxy (meth)acrylate resin containing a biphenyl skeleton, and an ester-type acid-modified epoxy (meth)acrylate resin containing a naphthol aralkyl skeleton.

[0126] The ester type acid-modified epoxy (meth) acrylate resin can be synthesized by a known method, or a commercially available product can be used. Specific examples of commercially available products include "CCR-1373H" (acid-modified epoxy acrylate resin containing a cresol novolac skeleton), "ZCR-8001H" (acid-modified epoxy acrylate resin containing a biphenyl skeleton), "ZCR-1569H" (acid-modified epoxy acrylate resin containing a biphenyl skeleton), "CCR-1171H" (acid-modified epoxy acrylate resin containing a cresol novolac skeleton), "ZCR-1797H", "ZCR-1761H" (acid-modified epoxy acrylate resin containing a biphenyl skeleton), and "ZCR-1801H" (acid-modified epoxy acrylate resin containing a biphenyl skeleton). "Acid-modified epoxy acrylate resin with a biphenyl skeleton), "ZAR-2000" manufactured by Nippon Kayaku Co., Ltd. (acid-modified epoxy acrylate resin containing a bisphenol A skeleton), "ZFR-1491H", "ZFR-1533H" (acid-modified epoxy acrylate resin containing a bisphenol F skeleton), "PR-300CP" manufactured by Showa Denko K.K. (cresol novolac type acid-modified epoxy acrylate resin), "CCR-1179" manufactured by Nippon Kayaku Co., Ltd. (epoxy acrylate resin containing a cresol novolac skeleton), etc.

[0127] The urethane acid-modified epoxy (meth)acrylate resin can be produced, for example, by reacting an epoxy (meth)acrylate resin with a diisocyanate compound and a carboxyl group-containing diol compound. The urethane acid-modified epoxy (meth)acrylate resin may be used alone or in combination of two or more.

[0128] Examples of the diisocyanate compound include aromatic diisocyanate compounds such as phenylene diisocyanate, toluene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenyl diisocyanate, and naphthalene diisocyanate; and aliphatic diisocyanate compounds such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, arylene sulfone ether diisocyanate, allyl cyanide diisocyanate, N-acyl diisocyanate, trimethylhexamethylene diisocyanate, and 1,3-bis(isocyanatemethyl)cyclohexane.

[0129] Examples of the carboxyl group-containing diol compound include dimethylol propionic acid, dimethylol butyric acid, and dimethylol nonanoic acid.

[0130] The carbamate-type acid-modified epoxy (meth)acrylate resin preferably includes a resin selected from a carbamate-type acid-modified epoxy (meth)acrylate resin containing a cresol novolac skeleton, a carbamate-type acid-modified epoxy (meth)acrylate resin containing a bisphenol A skeleton, a carbamate-type acid-modified epoxy (meth)acrylate resin containing a bisphenol F skeleton, an acid carbamate-type modified epoxy (meth)acrylate resin containing a biphenyl skeleton, and a carbamate-type acid-modified epoxy (meth)acrylate resin containing a naphthol aralkyl skeleton.

[0131] The carbamate type acid-modified epoxy (meth) acrylate resin can be synthesized by a known synthesis method, or a commercial product can be used. As a known synthesis method, for example, the method described in Japanese Patent Publication No. 2016-199719 can be cited. As a specific example of a commercial product, "UXE-3024", "UXE-3011", "UXE-3012", "UXE-3024" and the like manufactured by Nippon Kayaku Co., Ltd. can be cited.

[0132] As another embodiment of component (A), an unsaturated modified (meth) acrylic resin in which an ethylenically unsaturated group is introduced by reacting an epoxy compound containing an ethylenically unsaturated group with a (meth) acrylic resin having a structural unit obtained by polymerizing acrylic acid and / or methacrylic acid. Examples of epoxy compounds containing ethylenically unsaturated groups include glycidyl methacrylate, 4-hydroxybutyl (meth) acrylic acid glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylic acid. Furthermore, an acid anhydride can also be reacted with the hydroxyl group generated when the unsaturated group is introduced. As the acid anhydride, the same acid anhydride as the above-mentioned acid anhydride can be used. "(Meth) acrylic resin" includes methacrylic resin, acrylic resin, and combinations thereof.

[0133] As such unsaturated modified (meth) acrylic resin, commercially available products may be used. Specific examples thereof include "SPC-1000" and "SPC-3000" manufactured by Showa Denko K.K., and "CYCLOMER P(ACA)Z-250", "CYCLOMER P(ACA)Z-251", "CYCLOMER P(ACA)Z-254", "CYCLOMERP(ACA)Z-300", and "CYCLOMERP(ACA)Z-320" manufactured by Daicel-Allenex K.K.

[0134] From the viewpoint of improving the alkali developability of the resin composition, the acid value of the component (A) is preferably 0.1 mgKOH / g or more, more preferably 0.5 mgKOH / g or more, further preferably 1 mgKOH / g or more, 10 mgKOH / g or more, further preferably 20 mgKOH / g or more, 30 mgKOH / g or more, particularly preferably 40 mgKOH / g or more, 50 mgKOH / g or more. The upper limit of the acid value of the component (A) is preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less, further preferably 120 mgKOH / g or less, particularly preferably 100 mgKOH / g or less.

[0135] The weight average molecular weight of the component (A) is preferably 20,000 or less, more preferably 17,000 or less, and further preferably 15,000 or less, and is preferably 500 or more, more preferably 750 or more, and further preferably 900 or more. The weight average molecular weight is a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

[0136] When the non-volatile component of the core resin composition is set to 100% by mass, from the viewpoint of improving developability, the content of component (A) in the core resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, preferably 40% by mass or less, further preferably 35% by mass or less, and particularly preferably 30% by mass or less.

[0137] When the non-volatile component of the coating resin composition is set to 100% by mass, from the viewpoint of improving developability, the content of the component (A) in the coating resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, preferably 40% by mass or less, further preferably 35% by mass or less, and particularly preferably 30% by mass or less.

[0138] It should be noted that in the present invention, the content of each component in the core resin composition is a value when the non-volatile component in the core resin composition is set to 100% by mass unless otherwise specified, and the content of each component in the coating resin composition is a value when the non-volatile component in the coating resin composition is set to 100% by mass unless otherwise specified. The non-volatile component refers to all non-volatile components in the resin composition excluding the solvent.

[0139] <(B) Epoxy resin>

[0140] The resin composition contains an epoxy resin as component (B). The epoxy resin (B) as component (B) does not contain a resin corresponding to the above-mentioned component (A). By containing component (B), insulation reliability can be improved. The epoxy resin (B) can be used alone or in combination of two or more.

[0141] Examples of the epoxy resin (B) include: bixylenol epoxy resins; bisphenol-type epoxy resins such as bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, and bisphenol AF epoxy resins; dicyclopentadiene epoxy resins; novolac epoxy resins such as trisphenol epoxy resins and phenol novolac epoxy resins; tert-butyl-catechol epoxy resins; naphthalene-based epoxy resins, naphthol-based epoxy resins, naphthol aralkyl-based epoxy resins, naphthylene ether-based epoxy resins, and naphthol novolac-based epoxy resins; anthracene-based epoxy resins; Epoxy resin; glycidylamine type epoxy resin; glycidyl ester type epoxy resin; cresol novolac type epoxy resin; phenol aralkyl type epoxy resin; epoxy resin containing biphenyl skeleton; linear aliphatic epoxy resin; epoxy resin having butadiene structure; alicyclic epoxy resin; heterocyclic epoxy resin; epoxy resin containing spiro ring; cyclohexane type epoxy resin; cyclohexanedimethanol type epoxy resin; trimethylol type epoxy resin; tetraphenylethane type epoxy resin; isocyanurate type epoxy resin; phenolphthalimidine type epoxy resin, etc. Among them, from the viewpoint of significantly obtaining the effect of the present invention, the (B) epoxy resin preferably contains any one of a naphthalene type epoxy resin and a naphthol aralkyl type epoxy resin.

[0142] In the resin composition, the epoxy resin (B) preferably contains an epoxy resin having two or more epoxy groups in one molecule. The proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more relative to 100% by mass of the epoxy resin (B).

[0143] The epoxy resin (B) includes epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resin") and epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resin"). In the resin composition, the epoxy resin (B) may contain only a liquid epoxy resin, or only a solid epoxy resin, or both a liquid epoxy resin and a solid epoxy resin, but it is particularly preferred that only a solid epoxy resin is contained.

[0144] The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups in one molecule, and more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

[0145] As the solid epoxy resin, preferred are biphenylol type epoxy resin, naphthalene type epoxy resin, naphthol aralkyl type epoxy resin, naphthalene type tetrafunctional epoxy resin, naphthol novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, phenol aralkyl type epoxy resin, tetraphenylethane type epoxy resin, and phenolphthalimidine type epoxy resin, and preferably contain any one of naphthalene type epoxy resin and naphthol aralkyl type epoxy resin.

[0146] Specific examples of solid epoxy resins include: "HP4032H" manufactured by DIC Corporation (naphthalene-type epoxy resin); "HP-4700" and "HP-4710" manufactured by DIC Corporation (naphthalene-type tetrafunctional epoxy resin); "N-690" manufactured by DIC Corporation (cresol novolac-type epoxy resin); "N-695" manufactured by DIC Corporation (cresol novolac-type epoxy resin); "N-673" manufactured by DIC Corporation (cresol novolac-type epoxy resin); "HP-7200", "HP-7200HH", "HP-7200H", "HP-7200H" and "HP-7200H" manufactured by DIC Corporation. 00L" (dicyclopentadiene type epoxy resin); "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC31 00" (biphenyl type epoxy resin); "ESN475V", "ESN4100V" (naphthalene type epoxy resin) manufactured by Nippon Steel Chemicals; "ESN485" (naphthol type epoxy resin) manufactured by Nippon Steel Chemicals; "ESN375" (dihydroxynaphthalene type epoxy resin) manufactured by Nippon Steel Chemicals; "YX4000H", "YX4000", "YX4000HK", "YL7890" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical; "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical; "YX8800" manufactured by Mitsubishi Chemical (Anthracene type epoxy resin); "YX7700" manufactured by Mitsubishi Chemical Corporation (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YL7760" manufactured by Mitsubishi Chemical Corporation (bisphenol AF type epoxy resin); "YL7800" manufactured by Mitsubishi Chemical Corporation (fluorene type epoxy resin); "jER1010" manufactured by Mitsubishi Chemical Corporation (bisphenol A type epoxy resin); "jER1031S" manufactured by Mitsubishi Chemical Corporation (tetraphenylethane type epoxy resin); "WHR991S" manufactured by Nippon Kayaku Co., Ltd. (phenol benzopyrrolone type epoxy resin), etc. These can be used alone or in combination of two or more.

[0147] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0148] As the liquid epoxy resin, preferred are glycyrrhizin type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexanedimethanol type epoxy resin, cyclic aliphatic glycidyl ether and epoxy resin having a butadiene structure.

[0149] Specific examples of liquid epoxy resins include "EX-992L" manufactured by Nagase ChemteX, "YX7400" manufactured by Mitsubishi Chemical Corporation, "HP4032", "HP4032D", "HP4032SS" (naphthalene-based epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "828EL", "825", "Epikote" manufactured by Mitsubishi Chemical Corporation; "828EL" (bisphenol A type epoxy resin); "jER807", "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", "604" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (licorice phenol type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L", "EP-3980S" (glycidylamine type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene type epoxy resin) manufactured by ADEKA Corporation; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation; "EX-991L" manufactured by ChemteX (an epoxy resin containing an alkylene oxide skeleton and a butadiene skeleton); "CELLOXIDE2021P" manufactured by Daicel Corporation (an alicyclic epoxy resin with an ester skeleton); "PB-3600" manufactured by Daicel Corporation, "JP-100" and "JP-200" manufactured by Nippon Soda Co., Ltd. (epoxy resins with a butadiene structure); "ZX1658" and "ZX1658GS" manufactured by Nippon Steel Chemical Materials Co., Ltd. (liquid 1,4-glycidylcyclohexane type epoxy resins); "EG-280" manufactured by Osaka Gas Chemical Co., Ltd. (an epoxy resin containing a fluorene structure); "EX-201" manufactured by Nagase ChemteX (cyclic aliphatic glycidyl ether), etc.

[0150] When a solid epoxy resin and a liquid epoxy resin are used in combination as the epoxy resin (B), the mass ratio of these (solid epoxy resin:liquid epoxy resin) is preferably 10:1 to 1:50, more preferably 5:1 to 1:20, and particularly preferably 2:1 to 1:10.

[0151] The epoxy equivalent of the epoxy resin (B) is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 2,000 g / eq., further preferably 70 g / eq. to 1,000 g / eq., and further preferably 80 g / eq. to 500 g / eq. The epoxy equivalent is the mass of the resin per 1 equivalent of epoxy group. The epoxy equivalent can be measured according to JIS K7236.

[0152] (B) The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured as a value in terms of polystyrene by gel permeation chromatography (GPC).

[0153] When the non-volatile component of the core resin composition is set to 100 mass%, from the viewpoint of significantly obtaining the effect of the present invention, the content of the (B) epoxy resin in the core resin composition is preferably 20 mass% or more, more preferably 25 mass% or more, further preferably 30 mass% or more, preferably 50 mass% or less, more preferably 45 mass% or less, further preferably 40 mass% or less.

[0154] When the non-volatile component of the coating resin composition is set to 100% by mass, from the viewpoint of significantly obtaining the effect of the present invention, the content of the (B) epoxy resin in the coating resin composition is preferably 20% by mass or more, more preferably 25% by mass or more, further preferably 30% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less.

[0155] The content of the component (A) is represented by A core , the content of component (B) is set to B core When A core / B core From the viewpoint of significantly obtaining the effects of the present invention, it is preferably 0.3 or more, more preferably 0.5 or more, further preferably 1 or more, preferably 5 or less, more preferably 3 or less, further preferably 2 or less, the content of the component (A) being the content when the non-volatile component of the core resin composition is set to 100% by mass, and the content of the component (B) being the content when the non-volatile component of the core resin composition is set to 100% by mass.

[0156] The content of the component (A) is represented by A clad , the content of component (B) is set to B clad When A clad / B clad From the viewpoint of significantly obtaining the effect of the present invention, it is preferably 0.3 or more, more preferably 0.5 or more, further preferably 1 or more, preferably 5 or less, more preferably 3 or less, further preferably 2 or less, the content of the component (A) being the content when the non-volatile component of the coating resin composition is set to 100% by mass, and the content of the component (B) being the content when the non-volatile component of the coating resin composition is set to 100% by mass.

[0157] <(C) Photocurable resin>

[0158] The resin composition contains a (C) photocurable resin as the (C) component. The (C) photocurable resin as the (C) component does not contain a resin corresponding to the above-mentioned (A) to (B) components. By including the (C) component in the resin composition, the photoreactivity during exposure can be improved. The (C) component can be used alone or in combination of two or more.

[0159] As the component (C), for example, a (meth)acrylate compound having one or more (preferably two or more) (meth)acryloyl groups in one molecule can be used.

[0160] Examples of the (meth)acrylate compound include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxybutyl acrylate; monoacrylates or diacrylates of glycols such as ethylene glycol, methoxytetraglycol, polyethylene glycol, and propylene glycol; acrylamides such as N,N-dimethylacrylamide and N-hydroxymethylacrylamide; aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate; polyacrylates of polyols such as trimethylolpropane, pentaerythritol, and dipentaerythritol, or adducts of ethylene oxide, propylene oxide, or ε-caprolactone thereof; acrylates of phenols such as phenoxy acrylate and phenoxyethyl acrylate, or ethylene oxide or propylene oxide adducts thereof; epoxy acrylates derived from glycidyl ethers such as trimethylolpropane triglycidyl ether, modified epoxy acrylates, melamine acrylates, and / or methacrylates corresponding to the above-mentioned acrylates. Among them, polyhydric acrylates or polyhydric methacrylates are preferred. For example, as trihydric acrylates or methacrylates, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane EO addition tri(meth)acrylate, glycerol PO addition tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetrafurfuryl alcohol oligo(meth)acrylate, ethyl carbitol oligo(meth)acrylate, 1,4-butanediol oligo(meth)acrylate, 1,6-hexanediol oligo(meth)acrylate, trimethylolpropane oligo(meth)acrylate, pentaerythritol oligo(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like are exemplified. (Meth)acrylates, (meth)acrylates of N,N,N',N'-tetra(β-hydroxyethyl)ethyldiamine, etc. As trivalent or higher acrylates or methacrylates, examples include: tris(2-(meth)acryloyloxyethyl)phosphate, tris(2-(meth)acryloyloxypropyl)phosphate, tris(3-(meth)acryloyloxypropyl)phosphate, tris(3-(meth)acryloyl-2-hydroxyoxypropyl)phosphate, di(3-(meth)acryloyl-2-hydroxyoxypropyl)(2-(meth)acryloyloxyethyl)phosphate, (3-(meth)acryloyl-2-hydroxyoxypropyl)di(2-(meth)acryloyloxyethyl)phosphate and other phosphate triester (meth)acrylates. Any one of these photosensitive (meth)acrylate compounds may be used alone, or two or more thereof may be used in combination. "EO" refers to ethylene oxide.

[0161] As the component (C), a commercially available product may be used. Examples of the commercially available product include "DPHA" manufactured by Nippon Kayaku Co., Ltd. and "EBECRYL 3708" manufactured by Daicel-Allnex Co., Ltd.

[0162] The (C) component generally has a low viscosity. The specific viscosity of the (C) component is generally less than 0.5 Pa·s. The lower limit of the viscosity of the (C) component is not particularly limited, and may be, for example, 0.001 Pa·s or more, 0.005 Pa·s or more, 0.01 Pa·s or more, etc. The viscosity of the (C) component can be measured at 25±2°C using an E-type viscometer.

[0163] When the non-volatile component in the core resin composition is set to 100 mass%, from the viewpoint of promoting photocuring, the content of the component (C) in the core resin composition is preferably 15 mass% or more, more preferably 20 mass% or more, further preferably 25 mass% or more, preferably 40 mass% or less, more preferably 35 mass% or less, further preferably 30 mass% or less.

[0164] When the non-volatile component in the coating resin composition is set to 100% by mass, from the viewpoint of promoting photocuring, the content of the component (C) in the coating resin composition is preferably 15% by mass or more, more preferably 20% by mass or more, further preferably 25% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less.

[0165] The content of the component (C) is defined as C core When A core / C core From the viewpoint of significantly obtaining the effects of the present invention, the content of the component (C) is preferably greater than 0.1, more preferably greater than 0.3, further preferably greater than 0.5, preferably less than 3, more preferably less than 2, further preferably less than 1.5, and the content of the component (C) is the content when the non-volatile component of the core resin composition is set to 100% by mass.

[0166] The content of the component (C) is defined as C clad When A clad / C clad From the viewpoint of significantly obtaining the effects of the present invention, the content of the component (C) is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, preferably 3 or less, more preferably 2 or less, further preferably 1.5 or less, and the content of the component (C) is the content when the non-volatile component of the coating resin composition is set to 100% by mass.

[0167] From the viewpoint of significantly obtaining the effects of the present invention, C clad / C core It is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, or 0.8 or more, and preferably 3 or less, more preferably 2 or less, further preferably 1.5 or less. By adjusting the content of the component (C) contained in the core and covering resin compositions so that Cclad / C core When the shrinkage ratio is within the above range, the change in shrinkage ratio can be suppressed, and as a result, the reduction in light transmission loss can be suppressed.

[0168] <(D) Photopolymerization Initiator>

[0169] The resin composition contains a photopolymerization initiator as component (D). The photopolymerization initiator (D) as component (D) does not include substances corresponding to the above-mentioned components (A) to (C). By including the photopolymerization initiator (D) in the resin composition, the resin composition can be effectively photocured. Component (D) can be used alone or in combination of two or more.

[0170] (D) As the photopolymerization initiator, any compound may be used, and examples thereof include acylphosphine oxide-based photopolymerization initiators such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; oxime ester-based photopolymerization initiators such as 1,2-octanedione, 1-4-(phenylthio)-2-(O-benzoyl oxime), and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethanone 1-(O-acetoxime); 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-[4-(4-morpholino)phenyl]-1-butanone, 2-methyl -1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one and the like; α-aminoalkylphenone-based photopolymerization initiators; benzophenone, methylbenzophenone, o-benzoylbenzoic acid, benzoylethyl ether, 2,2-diethoxyacetophenone, 2,4-diethylthioxanthone, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)phenylphosphinate ethyl, 4,4'-bis(diethylamino)benzophenone, 1-hydroxycyclohexylphenylketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one, etc., and sulfonium salt-based photopolymerization initiators can also be used. These can be used alone or in combination of two or more. Among them, from the viewpoint of more effectively photocuring the resin composition, any one of an acylphosphine oxide-based photopolymerization initiator and an oxime ester-based photopolymerization initiator is preferred, and an acylphosphine oxide-based photopolymerization initiator is more preferred.

[0171] Specific examples of the (D) photopolymerization initiator include "Omnirad 907", "Omnirad 369", "Omnirad 379", "Omnirad 819", and "Omnirad TPO" manufactured by IGM Resins, "Irgacure OXE-01", "Irgacure OXE-02", "Irgacure TPO", and "Irgacure 819" manufactured by BASF, and "N-1919" manufactured by ADEKA.

[0172] From the viewpoint of fully photocuring the core resin composition, when the non-volatile component of the core resin composition is set to 100% by mass, the content of the (D) photopolymerization initiator in the core resin composition is preferably 1% by mass or more, more preferably 1.5% by mass or more, and further preferably 2% by mass or more. On the other hand, from the viewpoint of suppressing the reduction of developability caused by excessive sensitivity, the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 5% by mass or less.

[0173] From the viewpoint of making the coating resin composition fully photocurable, when the non-volatile component of the coating resin composition is set to 100 mass %, the content of the (D) photopolymerization initiator in the coating resin composition is preferably more than 1 mass %, more preferably more than 1.5 mass %, and further preferably more than 2 mass %. On the other hand, from the viewpoint of suppressing the development property reduction caused by the excessive sensitivity, the upper limit is preferably below 10 mass %, more preferably below 8 mass %, and further preferably below 5 mass %.

[0174] The content of the component (D) is represented by D core When A core / D core From the viewpoint of significantly obtaining the effects of the present invention, the content of the component (D) is preferably 3 or more, more preferably 5 or more, further preferably 8 or more, preferably 20 or less, more preferably 15 or less, further preferably 13 or less, and the content of the component (D) is the content when the non-volatile component of the core resin composition is set to 100% by mass.

[0175] The content of the component (D) is represented by D clad When A clad / D clad From the viewpoint of significantly obtaining the effects of the present invention, the content of the component (D) is preferably 3 or more, more preferably 5 or more, further preferably 8 or more, preferably 20 or less, more preferably 15 or less, further preferably 13 or less, and the content of the component (D) is the content when the non-volatile component of the coating resin composition is set to 100% by mass.

[0176] In the resin composition, as a photopolymerization initiation aid combined with the component (D), tertiary amines such as ethyl N,N-dimethylaminobenzoate, isopentyl N,N-dimethylaminobenzoate, amyl 4-dimethylaminobenzoate, triethylamine, and triethanolamine may be included, and photosensitizers such as pyrazolines, anthracenes, coumarins, xanthones, and thioxanthones may be included. Any one of these may be used alone, or two or more of them may be used in combination.

[0177] <(E) One or more flame retardants selected from phosphate compounds and phosphazene compounds>

[0178] The resin composition contains one or more flame retardants selected from phosphate compounds and phosphazene compounds as component (E). The one or more flame retardants selected from phosphate compounds and phosphazene compounds as component (E) do not include substances corresponding to the above-mentioned components (A) to (D). By including component (E) in the resin composition, the flame retardancy is improved while maintaining the single mode, thereby effectively suppressing the light transmission loss of the optical waveguide.

[0179] From the viewpoint of improving flame retardancy, when the non-volatile component in the resin composition is set to 100% by mass, the content of phosphorus atoms contained in the resin composition is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, further preferably 0.03% by mass or more, 0.05% by mass or more or 0.1% by mass or more. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, 1% by mass or less, 0.8% by mass or less or 0.5% by mass or less. Wherein, the content of phosphorus atoms refers to the concept of the content of phosphorus atoms contained in (A) component to (H) component except the phosphorus atoms contained in (E) component, and also includes the concept of the content of phosphorus atoms contained in (A) component to (H) component of (C) component.

[0180] (E) component includes any one of a phosphate compound and a phosphazene compound. Examples of the phosphate compound include compounds represented by the following formula (E-1); compounds represented by the following formula (E-2); non-halogen aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, and trioctyl phosphate; tris(dimethylphenyl)phosphate, triphenyl phosphate, tolyl diphenyl phosphate, ditolyl phenyl phosphate, tricresyl phosphate, tolyl di-2,6-dimethylphenyl phenyl phosphate, tris(2,6-dimethylphenyl)phosphate, tris(4-isopropylphenyl)phosphate, tris(4-tert-butylphenyl)phosphate, di(4-tert-butylphenyl)phosphate, Non-halogen aromatic phosphates such as tris(1-chloro-2-propyl)phosphate, tris(1,3-dichloro-2-propyl)phosphate, tris[3-bromo-2,2-bis(bromomethyl)propyl]phosphate; (meth)acrylic acid phosphates such as 2-methacryloyloxyethyl acid phosphate and diphenyl-2-methacryloyloxyethyl phosphate, etc.

[0181] Among them, as the phosphate ester compound, from the viewpoint of significantly obtaining the effects of the present invention, it is preferred that any one of the compound represented by formula (E-1) and the compound represented by formula (E-2) be contained.

[0182] [Chemical formula 3]

[0183]

[0184] In formula (E-1), R 1 ~R 20 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and W 1 It represents a group represented by formula (E-1a) or a group represented by formula (E-1b).

[0185] In the formula (E-1b), R represents an oxygen atom or a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent.

[0186] In formula (E-2), R 21 ~R 28 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and R 29 It represents a (meth)acryloyl group, an oxygen atom, a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or a monovalent group consisting of a combination thereof.

[0187] In formula (E-1), R 1 ~R 20 each independently represents a hydrogen atom, a hydroxyl group, or an optionally substituted alkyl group having 1 to 6 carbon atoms. The number of carbon atoms does not include the carbon atoms of the substituents. The alkyl group having 1 to 6 carbon atoms can be linear, branched, or cyclic. The alkyl group having 1 to 6 carbon atoms is preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, and the like.

[0188] R 1 ~R 20 The alkyl group having 1 to 6 carbon atoms represented may have no substituent or may have a substituent. The substituents are not particularly limited. Examples thereof include a halogen atom, a hydroxyl group, -O-C 1-6 alkyl, -N(C 1-10 alkyl)2, C 1-10 alkyl, C 6-10 aryl, -NH2, -CN, -C(O)O-C 1-10 alkyl, -COOH, -C(O)H, -NO2, and the like. Here, the term "C p-q " (p and q are positive integers, satisfying p < q.) represents that the number of carbon atoms of the organic group described immediately after this term is p to q. For example, an expression such as "C 1-10 alkyl" represents an alkyl group having 1 to 10 carbon atoms. These substituents may combine with each other to form a ring, and the ring structure also includes a spiro ring and a fused ring.

[0189] The above substituents may further have substituents (hereinafter sometimes referred to as "secondary substituents"). As the secondary substituents, the same groups as the above substituents can be used as long as there is no particular description.

[0190] In formula (E-1), R 1 、R 5 、R 6 、R 10 、R 11 、R 15 、R 16 and R 20 preferably represent an optionally substituted alkyl group having 1 to 6 carbon atoms, and R 2 ~R 4 、R 7 ~R 9 、R 12 ~R 14 and R 17 ~R 19 preferably represent a hydrogen atom.

[0191] In formula (E-1), W 1 It represents a group represented by formula (E-1a) or a group represented by formula (E-1b). Examples of the group represented by formula (E-1a) include the following groups (E-1a-1) to (E-1a-3), and preferably the group represented by formula (E-1a-3). In the formula, * represents a connecting bond.

[0192] [Chemical formula 4]

[0193]

[0194] In formula (E-1b), R represents an oxygen atom or a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. The number of carbon atoms does not include the number of carbon atoms of the substituent. The divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent represented by R preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and further preferably 1 to 6 carbon atoms. The divalent hydrocarbon group may be any of a linear, branched, or cyclic shape, and is preferably a cyclic divalent hydrocarbon group. Examples of the divalent hydrocarbon group include a divalent aliphatic hydrocarbon group and a divalent aromatic hydrocarbon group, and are preferably divalent aliphatic hydrocarbon groups. Examples of the divalent hydrocarbon group include a divalent saturated hydrocarbon group and a divalent unsaturated hydrocarbon group, and are preferably divalent saturated hydrocarbon groups. Specific examples of the divalent hydrocarbon group include an alkylene group, an alkenylene group, an alkynylene group, and an arylene group.

[0195] Examples of the alkylene group include ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, a group of the following formula (E-2a-1), a group of the following formula (E-2a-2), and the like, preferably a group of the following formula (E-2a-1). In the formula, * represents a connecting bond.

[0196] [Chemical formula 5]

[0197]

[0198] Examples of the alkenylene group include vinylene, propenylene, butenylene, pentenylene, hexenylene, heptenylene, octenylene, nonenylene, decenylene and the like.

[0199] Examples of the alkynylene group include ethynylene, propynylene, butynylene, pentynylene, hexynylene, heptynylene, octynylene, nonynylene and decynylene.

[0200] Examples of the arylene group include a phenylene group and a naphthylene group.

[0201] Among them, in formula (E-1b), R is preferably an alkylene group having 1 to 20 carbon atoms which may have a substituent, more preferably an alkylene group having 1 to 10 carbon atoms which may have a substituent, further preferably an alkylene group having 1 to 8 carbon atoms which may have a substituent, further preferably an alkylene group having 1 to 6 carbon atoms which may have a substituent, and particularly preferably a group of formula (E-2a-1).

[0202] The divalent hydrocarbon group having 1 to 20 carbon atoms represented by R may or may not have a substituent. 1 The substituents optionally possessed by the divalent hydrocarbon group having 1 to 20 carbon atoms represented by R are preferably C 1-10 The alkyl group is preferably a methyl group.

[0203] Examples of the group represented by formula (E-1b) include the following groups (E-1b-1) to (E-1b-6), preferably the group (E-1b-1). Here, R is the same as R in formula (E-1b). In the formula, * represents a connecting bond.

[0204] [Chemical formula 6]

[0205]

[0206] Examples of the compound represented by formula (E-1) include the compounds exemplified below, but the compound is not limited thereto.

[0207] [Chemical formula 7]

[0208]

[0209] In formula (E-2), R 21 ~R 28 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and R in formula (E-1) 1 The same. Among them, R 21 ~R 28 Preferably it represents a hydrogen atom.

[0210] In formula (E-2), R 29 represents a (meth)acryloyl group, an oxygen atom, a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or a monovalent group formed by a combination thereof. The divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent is the same as the divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent represented by R in formula (E-1b).

[0211] The monovalent hydrocarbon group having 1 to 20 carbon atoms which may optionally have a substituent preferably has 1 to 15 carbon atoms, more preferably has 1 to 10 carbon atoms, and further preferably has 1 to 6 carbon atoms. The number of carbon atoms does not include the number of carbon atoms of the substituent. The monovalent hydrocarbon group may be any of linear, branched, and cyclic, and is preferably a linear monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include a monovalent aliphatic hydrocarbon group and a monovalent aromatic hydrocarbon group, and are preferably a monovalent aromatic hydrocarbon group. The monovalent hydrocarbon group may be any of a monovalent saturated hydrocarbon group and a monovalent unsaturated hydrocarbon group, and are preferably a monovalent unsaturated hydrocarbon group. Specific examples of the monovalent hydrocarbon group include alkyl, alkenyl, alkynyl, aryl, and the like. The substituents which the monovalent hydrocarbon group having 1 to 20 carbon atoms may optionally have are the same as R in formula (E-1). 1 The substituents which may be possessed are the same. Among them, the substituent which may be possessed by the monovalent hydrocarbon group having 1 to 20 carbon atoms is preferably a hydroxyl group.

[0212] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group.

[0213] Examples of the alkenyl group include ethenyl, propenyl, butenyl, and pentenyl.

[0214] Examples of the alkynyl group include an ethynyl group, a propynyl group, a butynyl group, a sec-butynyl group, an isobutynyl group, a tert-butynyl group and a pentynyl group.

[0215] Examples of the aryl group include a phenyl group, a naphthyl group, and a 2,5-dihydroxyphenyl group, and a 2,5-dihydroxyphenyl group is preferred.

[0216] The monovalent group formed by the combination thereof is preferably a monovalent group obtained by combining a (meth)acryloyl group, an oxygen atom, and a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, more preferably a monovalent group obtained by combining a (meth)acryloyl group and an alkylene group having 1 to 10 carbon atoms which may have a substituent, and still more preferably a monovalent group obtained by combining a (meth)acryloyl group and a methylene group.

[0217] R 29 Preferably, it is an aryl group which may have a substituent, or a monovalent group obtained by combining a (meth)acryloyl group, an oxygen atom, and a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. More preferably, it is an aryl group which may have a substituent, or a monovalent group obtained by combining a (meth)acryloyl group and an alkylene group having 1 to 10 carbon atoms which may have a substituent. Still more preferably, it is a 2,5-dihydroxyphenyl group, or a monovalent group obtained by combining a (meth)acryloyl group and a methylene group.

[0218] Examples of the compound represented by formula (E-2) include the compounds exemplified below, but the compound is not limited thereto.

[0219] [Chemical formula 8]

[0220]

[0221] The phosphazene compound is not particularly limited as long as it is a cyclic compound containing nitrogen and phosphorus as constituent elements, but the phosphazene compound is preferably a phosphazene compound having a phenolic hydroxyl group.

[0222] The phosphazene compound is preferably a compound represented by the following formula (E-3).

[0223] [Chemical formula 9]

[0224]

[0225] (In formula (E-3), R 31 and R 32 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent. n represents an integer of 3 to 25, and m1 and m2 each independently represent an integer of 0 to 5. )

[0226] R 31 and R 32 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and the alkyl group having 1 to 6 carbon atoms which may have a substituent and R in formula (E-1) 1 The alkyl groups having 1 to 6 carbon atoms which may have a substituent are the same as those represented by R 31 and R 32 Each independently preferably represents a hydrogen atom, a hydroxyl group or a methyl group.

[0227] n represents an integer of 3 to 25, preferably an integer of 3 to 15, more preferably an integer of 3 to 10, and further preferably 3.

[0228] m1 and m2 each independently represent an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 0 or 1.

[0229] Examples of the compound represented by formula (E-3) include the compounds exemplified below, but are not limited thereto.

[0230] [Chemical formula 10]

[0231]

[0232] (E) Components can be commercially available. Examples of commercially available products include "HCA-HQ", "HCA-HQ-HS", and "HCA=NQ" manufactured by Sanko Co., Ltd., "SR-3000" and "PX-200" manufactured by Daihachi Kogyo Chemical Co., Ltd., "SPS-100" manufactured by Otsuka Chemical Co., Ltd., "FP-100" manufactured by Fushimi Pharmaceutical Co., Ltd., "SPH-100", "SPS-100", "SPB-100", and "SPE-100" manufactured by Otsuka Chemical Co., Ltd., "FP-100", "FP-110", "FP-300", "FP-400", and "FP-390" manufactured by Fushimi Pharmaceutical Co., Ltd., and "FRM-1000" manufactured by Nippon Kayaku Co., Ltd.

[0233] When the non-volatile component in the core resin composition is set to 100 mass%, from the viewpoint of promoting photocuring, the content of the component (E) in the core resin composition is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, further preferably 0.1 mass% or more, preferably 1 mass% or less, more preferably 0.5 mass% or less, further preferably 0.3 mass% or less.

[0234] When the non-volatile component in the coating resin composition is set to 100% by mass, from the viewpoint of promoting photocuring, the content of the component (E) in the coating resin composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, further preferably 0.5% by mass or more, preferably 10% by mass or less, more preferably 8% by mass or less, further preferably 5% by mass or less, 4% by mass or less, or 3% by mass or less.

[0235] The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core The content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %. The upper limit is 12 or less, preferably 10 or less, more preferably 5 or less, and more preferably 4 or less or 3 or less. By adjusting the content of the component (E) contained in the core and coating resin compositions so that E clad -E core When the shrinkage ratio is within the above range, the change in shrinkage ratio can be suppressed, and as a result, the reduction in light transmission loss can be suppressed.

[0236] From the viewpoint of significantly obtaining the effects of the present invention, A core / E core It is preferably 50 or more, more preferably 100 or more, further preferably 130 or more, and is preferably 300 or less, more preferably 250 or less, further preferably 200 or less.

[0237] From the viewpoint of significantly obtaining the effects of the present invention, A clad / E clad It is preferably 1 or more, more preferably 1.5 or more, further preferably 2 or more, and is preferably 100 or less, more preferably 75 or less, further preferably 50 or less.

[0238] <(F) Curing accelerator>

[0239] The resin composition may contain a (F) curing accelerator as an optional component. The (F) curing accelerator as the (F) component does not include substances corresponding to the above-mentioned (A) to (E) components. The (F) curing accelerator can function as a catalyst for the reaction of components such as the (B) epoxy resin contained in the resin composition to promote the curing of the resin composition.

[0240] Examples of curing accelerators include imidazole curing accelerators, phosphorus curing accelerators, urea curing accelerators, guanidine curing accelerators, metal curing accelerators, and amine curing accelerators. Among them, imidazole curing accelerators are preferred. (F) Curing accelerators may be used alone or in combination of two or more.

[0241] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1') imidazole compounds and adducts of imidazole compounds and epoxy resins such as 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline. Commercially available products of imidazole-based curing accelerators include, for example, "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemical Industries, Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0242] Phosphorus-based curing accelerators include, for example, aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetramethylolate, and the like. Aromatic phosphonium salts such as phenyl borate, tetraphenylphosphonium tetraphenyl borate, tetraphenylphosphonium tetra-p-tolyl borate, triphenylethylphosphonium tetraphenyl borate, tris(3-methylphenyl)ethylphosphonium tetraphenyl borate, tris(2-methoxyphenyl)ethylphosphonium tetraphenyl borate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-benzoquinone addition reactants such as triphenylphosphine-p-benzoquinone addition reactants; tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butyl)phosphine, tri-tert-butyl ... aliphatic phosphines such as dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri(4-ethylphenyl)phosphine, tri(4-propylphenyl)phosphine, tri(4-isopropylphenyl)phosphine, tri(4-butylphenyl)phosphine, tri(4-tert-butylphenyl)phosphine, tri(2,4-dimethylphenyl)phosphine, tri(2,5-dimethylphenyl)phosphine, tri(2,6-dimethylphenyl)phosphine Aromatic phosphines such as tris(diphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether.

[0243] Examples of the urea curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, 3-(3,4-dimethylphenyl)-1, Aromatic dimethyl urea such as 1-dimethyl urea, 3-(4-isopropylphenyl)-1,1-dimethyl urea, 3-(4-methoxyphenyl)-1,1-dimethyl urea, 3-(4-nitrophenyl)-1,1-dimethyl urea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethyl urea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethyl urea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethyl urea, N,N-(1,4-phenylene)bis(N',N'-dimethyl urea), N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethyl urea) [toluenebisdimethyl urea], and the like.

[0244] Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine.

[0245] As metal curing accelerators, for example, metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin, organic metal complexes or organic metal salts can be cited. As specific examples of organic metal complexes, organic cobalt complexes such as cobalt acetylacetonate (II), cobalt acetylacetonate (III), organic copper complexes such as copper acetylacetonate (II), organic zinc complexes such as zinc acetylacetonate (II), organic iron complexes such as iron acetylacetonate (III), organic nickel complexes such as nickel acetylacetonate (II), and organic manganese complexes such as manganese acetylacetonate (II). As organic metal salts, for example, zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate, etc. can be cited.

[0246] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. A commercially available amine curing accelerator may be used, and examples thereof include "MY-25" manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0247] When the non-volatile component in the core resin composition is set to 100 mass%, from the viewpoint of promoting photocuring, the content of the component (F) in the core resin composition is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, further preferably 0.3 mass% or more, preferably 1.5 mass% or less, more preferably 1 mass% or less, further preferably 0.8 mass% or less.

[0248] When the non-volatile component in the coating resin composition is set to 100 mass%, from the viewpoint of promoting photocuring, the content of the component (F) in the coating resin composition is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, further preferably 0.3 mass% or more, preferably 1.5 mass% or less, more preferably 1 mass% or less, further preferably 0.5 mass% or less.

[0249] <(G)Solvent>

[0250] The resin composition may further contain (G) a solvent as an optional component. By containing (G) a solvent, the viscosity of the varnish can be adjusted. Examples of (G) the solvent include organic solvents.

[0251] As (G) solvent, for example, ketones such as ethyl methyl ketone (MEK) and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate (EDGAc), methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and diethylene glycol monoethyl ether acetate (ethyl diglycol acetate); aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha. These solvents can be used alone or in combination of two or more. The content of the solvent when used can be appropriately adjusted from the perspective of the coating property of the resin composition.

[0252] <(H) Other additives>

[0253] The resin composition may further contain (H) other additives to the extent that the purpose of the present invention is not hindered. As (H) other additives, for example, fine particles of inorganic fillers, organic fillers, melamine, organic swelling soil, etc.; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, etc.; polymerization inhibitors such as hydroquinone, phenothiazine, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc.; thickeners such as Benton and montmorillonite; silicone-based, fluorine-based, and vinyl resin-based defoamers; various additives of thermosetting resins such as phenol-based curing agents and cyanate-based curing agents.

[0254] The resin composition can be produced by mixing the above-mentioned (A) to (E) components as essential components and appropriately mixing the above-mentioned (F) to (H) components as optional components, and further, kneading or stirring using a kneading device such as a three-roll mill, a ball mill, a bead mill, a sand mill, or a stirring device such as a high-speed mixer or a planetary mixer as needed.

[0255] <Physical Properties of Photosensitive Resin Composition Set>

[0256] The refractive index of the cured product obtained by heating the core resin composition at 190° C. for 90 minutes and curing it is preferably 1.3 or more, more preferably 1.4 or more, and further preferably 1.5 or more, and is preferably 2 or less, more preferably 1.9 or less, and further preferably 1.8 or less. The refractive index can be measured by the method described in the Examples described below.

[0257] The refractive index of the cured product obtained by heating the coating resin composition at 190° C. for 90 minutes and curing it is preferably 1.3 or more, more preferably 1.4 or more, and further preferably 1.5 or more, and is preferably 2 or less, more preferably 1.9 or less, and further preferably 1.8 or less. The refractive index can be measured by the method described in the examples described below.

[0258] The photosensitive resin composition set of the present invention may have a refractive index n such that the numerical aperture NA represented by the following formula (1) is controlled within a specific range. core and refractive index n clad .

[0259] [Mathematical formula 1]

[0260]

[0261] In formula (1), n core represents the refractive index of the cured product of the core resin composition, n clad Refractive index n represents the refractive index of the cured product of the coating resin composition. core and refractive index n cladThe measurement wavelength is the wavelength of the light transmitted by the optical waveguide, for example, 1310 nm. Specifically, the numerical aperture NA is, for example, 0.03 or more, preferably 0.04 or more, more preferably 0.05 or more or 0.06 or more. The upper limit of the numerical aperture NA is, for example, less than 0.3, preferably 0.2 or less, more preferably 0.18 or less, and further preferably 0.16 or less or 0.15 or less. The numerical aperture NA can be measured according to the method described in the embodiments described later.

[0262] The photosensitive resin composition set of the present invention can produce an optical waveguide with a small difference in shrinkage between the core layer and the cladding layer. core Shrinkage rate S of the coating layer clad The difference (|S core -S clad |) is preferably less than 0.05, more preferably less than 0.05, further preferably less than 0.04, less than 0.03, less than 0.02, and less than 0.01. The lower limit is not particularly limited, but can be set to be greater than 0, greater than 0.0001, etc. The difference in shrinkage can be measured according to the method described in the examples described later.

[0263] Since the resin composition combination contains components (A) to (E), it exhibits excellent developability (clarity). Therefore, an optical waveguide with excellent fine line waveguide formability can be formed. For example, when trying to form a circuit layer with a thickness of 5 μm and an L / S (line width / line spacing) of 5 μm / 5 μm, and a circuit layer with a thickness of 50 μm and an L / S (line width / line spacing) of 50 μm / 50 μm, it is preferred to be able to form at least one, and particularly preferred to be able to form both. The evaluation of developability can be evaluated according to the method described in the examples described later.

[0264] The cured product obtained by thermally curing the resin composition at 190°C for 90 minutes shows excellent flame retardancy. That is, an optical waveguide with excellent flame retardancy is provided. Specifically, the core and coating resin compositions are overlapped, and the overlapping core and coating resin compositions are thermally cured at 190°C for 90 minutes to obtain a sample. The flame retardancy of the sample is preferably that there is no falling of the burning material and the whole burning of the test piece in the flame retardancy test (UL-94), and the burning time of the test piece is more than 50 seconds and less than 250 seconds, more preferably that there is no falling of the burning material and the whole burning of the test piece, and the burning time of the test piece is less than 50 seconds, and more preferably it is more excellent than these cases. The evaluation of flame retardancy can be measured according to the method described in the embodiments described later.

[0265] Since the resin composition combination contains components (A) to (E), it shows the property of reducing the light transmission loss before the high temperature placement test (HTS test). Specifically, a test substrate having a cladding layer and a core layer formed using a photosensitive resin composition set is prepared. The light transmission loss is measured using the test substrate. At this time, the light transmission loss is preferably less than 0.5dB / cm, more preferably less than 0.4dB / cm. There is no particular restriction on the lower limit, but it can be set to 0dB / cm or more, 0.1dB / cm or more, etc. The light transmission loss can be measured according to the method described in the embodiments described later.

[0266] Since the resin composition combination contains components (A) to (E), it usually shows the property of reducing the rate of change of light transmission loss before and after a high temperature placement test (HTS test). Specifically, a test substrate having a cladding layer and a core layer formed using a photosensitive resin composition set is prepared. Using the test substrate, the light transmission loss before and after the HTS test is measured. At this time, the rate of change of light transmission loss is preferably less than 30%, more preferably less than 20%, and further preferably less than 15%. There is no particular restriction on the lower limit, and it can be set to 0% or more, 0.1% or more, etc. The rate of change of light transmission loss can be measured according to the method described in the embodiments described later.

[0267] [Photosensitive resin sheet set]

[0268] Photosensitive resin compositions such as core resin compositions and coating resin compositions can also be used as resin sheets. A resin sheet is a sheet having a resin composition layer containing a resin composition. Therefore, a resin sheet having a resin composition layer containing the core resin composition (hereinafter sometimes referred to as a "core resin sheet") can be obtained from the core resin composition. In addition, a resin sheet having a resin composition layer containing the coating resin composition (hereinafter sometimes referred to as a "coating resin sheet") can be obtained from the coating layer resin composition. Moreover, a photosensitive resin sheet set containing these core resin sheets and coating resin sheets can be obtained as a sheet set for the manufacture of optical waveguides. According to the photosensitive resin sheet set, the same advantages as the above-mentioned photosensitive resin composition set can be obtained, and further, the optical waveguide can be manufactured by a lamination method, so the manufacture of the optical waveguide can be carried out more simply.

[0269] <Core resin sheet>

[0270] The resin composition layer of the core resin sheet usually contains a core resin composition, preferably only a core resin composition. The thickness of the resin composition layer of the core resin sheet can be set according to the thickness of the core layer. In terms of a specific range, the thickness of the resin composition layer of the core resin sheet is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 3 μm or more, preferably 100 μm or less, more preferably 50 μm or less, and particularly preferably 20 μm or less.

[0271] The core resin sheet may include a support. For example, the core resin sheet may include a support and a resin composition layer formed on the support. Examples of the support include polyethylene terephthalate films, polyethylene naphthalate films, polypropylene films, polyethylene films, polyvinyl alcohol films, triacetyl acetate films, and the like, with polyethylene terephthalate films being particularly preferred.

[0272] Examples of commercially available supports include: polypropylene films such as "ALPHAN MA-410" and "E-200C" manufactured by Oji Paper Co., Ltd., and polypropylene films such as "PS-25" manufactured by Teijin Co., Ltd. PS series polyethylene terephthalate films, etc. In order to facilitate peeling of the support after lamination, a peeling agent such as an alkyd release agent or a silicone coating agent may be applied to the surface of the support.

[0273] The thickness of the support is preferably in the range of 5 μm to 100 μm, more preferably in the range of 10 μm to 50 μm.

[0274] In addition, in order to reduce the scattering of light when exposed to active light such as ultraviolet rays, the support is preferably a support with excellent transparency. Specifically, the support is preferably a support with a turbidity (haze standardized by JIS K6714) of 0.1 to 5 as a transparency index. Furthermore, the resin composition layer can be protected by a protective film.

[0275] The core resin sheet may also be provided with a protective film for protecting the resin composition layer. Typically, the protective film is provided on the side of the resin composition layer opposite to the support. As the protective film, for example, a film formed of the same material as the support may be used. The adhesion between the protective film and the resin composition layer is preferably less than the adhesion between the support and the resin composition layer. Typically, the core resin sheet may be used after peeling off the protective film. It should be noted that for the protective film, it is preferred that the adhesion between the resin composition layer and the protective film is smaller than the adhesion between the resin composition layer and the support.

[0276] The core resin sheet can be manufactured as follows: for example, a resin varnish obtained by dissolving the core resin composition in an organic solvent is prepared, the resin varnish is applied on a support, and the organic solvent is dried by heating or blowing hot air, etc. to form a resin composition layer, thereby manufacturing. Specifically, after the bubbles in the core resin composition are completely removed by a vacuum degassing method, the core resin composition is applied to the support, and the solvent is removed and dried by a hot air furnace or a far infrared furnace, and then a protective film is laminated on the obtained resin composition layer as needed, thereby manufacturing a core resin sheet. The specific drying conditions also vary depending on the curability of the core resin composition and the amount of organic solvent in the resin varnish. For a resin varnish containing 30% to 60% by mass of an organic solvent, it can be dried at 80°C to 120°C for 3 minutes to 13 minutes. From the viewpoint of preventing the diffusion of organic solvents in subsequent processes, the amount of residual organic solvent in the core resin composition layer is preferably set to 5% by mass or less relative to the total amount of the resin composition layer, and more preferably set to 2% by mass or less. A person skilled in the art can appropriately set suitable drying conditions through simple experiments.

[0277] Examples of coating methods for the core resin composition include gravure coating, micro gravure coating, reverse coating, kiss reverse coating, die coating, slot die, lip coating, comma coating, blade coating, roll coating, knife coating, curtain coating, chamber gravure coating, slot orifice, spray coating, and dip coating.

[0278] The core resin composition can be applied in several times or in a single application. In addition, different methods can be combined to apply the coating. Among them, the die coating method with excellent uniform coating property is preferred. In addition, in order to avoid the mixing of foreign matter, the coating process is preferably carried out in an environment with little foreign matter generation, such as a clean room.

[0279] <Coating resin sheet>

[0280] The resin composition layer of the coating resin sheet usually contains the coating resin composition, preferably only contains the coating resin composition. The thickness of the resin composition layer of the coating resin sheet can be set according to the thickness of the coating layer. In terms of a specific range, the thickness of the resin composition layer of the coating resin sheet is preferably 5 μm or more, more preferably 7 μm or more, further preferably 10 μm or more, preferably 40 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less.

[0281] The coating resin sheet may be the same as the core resin sheet except that the resin composition layer containing the coating resin composition is replaced by the resin composition layer containing the core resin composition. Therefore, the coating resin sheet may also be provided with a support. The support of the coating resin sheet may be the same as the support of the core resin sheet. In addition, the coating resin sheet may also be provided with a protective film. The protective film of the coating resin sheet may be the same as the protective film of the core resin sheet. Usually, the coating resin sheet can be used after peeling off the protective film.

[0282] The cover resin sheet can be produced by the same method as the core resin sheet except that the cover resin composition is used instead of the core resin composition.

[0283] The resin composition layer of the covering resin sheet may contain a solvent, but the amount of the solvent is preferably small. In one example, the range of the amount of solvent contained in the resin composition layer of the covering resin sheet may be the same as the range of the amount of solvent contained in the resin composition layer of the core resin sheet.

[0284] [Optical waveguide, and method for manufacturing the optical waveguide]

[0285] The above-mentioned photosensitive resin composition set and photosensitive resin sheet set can be used to produce an optical waveguide. Hereinafter, embodiments of the optical waveguide will be described using the drawings.

[0286] Figure 1 FIG. 1 is a perspective view schematically showing an optical waveguide 10 according to an embodiment of the present invention. Figure 1 As shown, the optical waveguide 10 includes a core layer 100 and a cladding layer 200. The core layer 100 includes a cured product of the core resin composition of the present invention, and preferably includes only a cured product of the core resin composition of the present invention. In addition, the cladding layer 200 includes a cured product of the coating resin composition of the present invention, and preferably includes only a cured product of the coating resin composition of the present invention. The cured product of the coating resin composition preferably has a lower refractive index than the cured product of the core resin composition.

[0287] The core layer 100 is disposed in the cladding layer 200. Therefore, the core layer 100 is covered by the cladding layer 200. Typically, all peripheral surfaces of the core layer 100 are covered by the cladding layer 200. The core layer 100 is in direct contact with the cladding layer 200 without sandwiching other layers therebetween, and thus, an interface 100I can be formed between the core layer 100 and the cladding layer 200. Typically, the core layer 100 has a higher refractive index than the cladding layer 200, and thus, light (not shown) can be transmitted within the core layer 100 from one end (one end on the incident side) 100A of the core layer 100 to the other end (one end on the emission side) 100B.

[0288] The wavelength of light that can be transmitted by the optical waveguide 10 can be selected in various ways. For example, the preferred wavelength range of the transmitted light can be 840nm to 860nm (e.g., 850nm), 1300nm to 1320nm (e.g., 1310nm), 1540nm to 1560nm (e.g., 1550nm), etc. Among them, the wavelength range of the light transmitted in the optical transmission path 10 is preferably 1300nm to 1320nm.

[0289] The optical waveguide 10 may be a single-mode optical waveguide or a multi-mode optical waveguide, preferably a single-mode optical waveguide. The optical waveguide 10 is preferably a single-mode optical waveguide for light in the aforementioned preferred wavelength range. For example, the optical waveguide 10 is preferably a single-mode optical waveguide for light of 1310 nm.

[0290] The width L of the core layer 100 is preferably set appropriately within a range that can transmit light. The specific range of the line width L of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, particularly preferably 2 μm or more, preferably 50 μm or less, more preferably 30 μm or less, particularly preferably 20 μm or less, and can be 10 μm or less or 5 μm or less. The width L of the core layer 100 is equivalent to the line width (line width) of the core layer 100 when observed from the thickness direction.

[0291] The spacing S of the core layer 100 is preferably set appropriately within a range that allows light to be transmitted. The specific range of the spacing S of the core layer 100 is preferably 50 μm or more, more preferably 70 μm or more, particularly preferably 100 μm or more, preferably 1000 μm or less, more preferably 500 μm or less, particularly preferably 300 μm or less. The spacing S of the core layer 100 is equivalent to the spacing (pitch) of the core layer observed from the thickness direction.

[0292] The thickness T of the core layer 100 is preferably set appropriately within a range capable of transmitting light. The specific range of the thickness T of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, particularly preferably 2 μm or more, preferably 50 μm or less, more preferably 30 μm or less, particularly preferably 20 μm or less, and can be 10 μm or less.

[0293] The thickness of the cladding layer 200 is usually greater than that of the core layer 100. The specific thickness of the cladding layer 200 is preferably 5 μm or more, more preferably 7 μm or more, particularly preferably 10 μm or more, and preferably 40 μm or less, more preferably 30 μm or less, particularly preferably 20 μm or less.

[0294] The optical waveguide 10 may include optional elements other than the core layer 100 and the cladding layer 200 as required. For example, the optical waveguide 10 may include a substrate 300. In the optical waveguide 10 including the substrate 300, the cladding layer 200 is generally provided on the substrate 300, and the core layer 100 is provided in the cladding layer 200.

[0295] As the substrate 300, a hard substrate such as a glass substrate, a metal substrate, a ceramic substrate, a wafer, a circuit substrate, etc. can be used. As a wafer, for example, a semiconductor wafer such as a silicon wafer, a gallium arsenide (GaAs) wafer, an indium phosphide (InP) wafer, a gallium phosphide (GaP) wafer, a gallium nitride (GaN) wafer, a gallium telluride (GaTe) wafer, a zinc selenide (ZnSe) wafer, a silicon carbide (SiC) wafer, etc. can be used, and a pseudo wafer can also be used. As a pseudo wafer, for example, a plate-like member having a molded resin and electronic components embedded in the molded resin can be used. As a circuit substrate, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, etc. can be cited. It should be noted that the circuit substrate here refers to: a substrate having a patterned conductor layer (circuit) formed on one or both sides of the above-mentioned substrate. Furthermore, a film formed of a plastic material such as polyethylene terephthalate, polyimide, or polyester can be used as the substrate 300. Furthermore, a flexible circuit substrate can be used as the substrate 300.

[0296] In addition, the optical waveguide 10 may include, as an optional element, a protective layer (not shown) for protecting the core layer 100 and the cladding layer 200. The protective layer may be provided, for example, to cover the surface of the cladding layer 200 opposite to the substrate 300.

[0297] As described above, the optical waveguide 10 can have a small transmission loss. In addition, the optical waveguide 10 can be formed using a core resin composition and a cladding resin composition that have excellent core formability and can suppress the generation of surface irregularities, so that fine wiring of the core layer can be achieved, and it can be formed with a small line width L as described above.

[0298] The optical waveguide 10 can be manufactured using any one of the photosensitive resin composition set of the present invention and the photosensitive resin sheet set of the present invention. For example, the optical waveguide 10 can be manufactured by a method including the following steps in sequence:

[0299] Step (I) of forming a first composition layer including a coating resin composition,

[0300] Step (II) of curing the first composition layer,

[0301] Step (III) of forming a second composition layer including a core resin composition on the first composition layer,

[0302] a step (IV) of subjecting the second composition layer to an exposure treatment,

[0303] A step (V) of developing the second composition layer,

[0304] Step (VI) of curing the second composition layer,

[0305] Step (VII) of forming a third composition layer comprising a coating resin composition on the second composition layer, and

[0306] A step (VIII) of curing the third composition layer.

[0307] Figure 2 Schematic cross-sectional view for explaining step (I) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 2 As shown, the method for producing an optical waveguide according to one embodiment of the present invention includes a step (I) of forming a first composition layer 210 including a coating resin composition. In this embodiment, an example of forming the first composition layer 210 on a substrate 300 is described.

[0308] There is no particular limitation on the method for forming the first composition layer 210. For example, the first composition layer 210 can be formed by coating the coating resin composition on the substrate 300. From the viewpoint of smooth coating, a varnish-like coating resin composition containing a solvent can be prepared and the varnish-like coating resin composition can be coated.

[0309] Examples of coating methods include gravure coating, micro gravure coating, reverse coating, contact reverse coating, die coating, slit extrusion, lip die coating, comma coating, blade coating, roll coating, knife coating, curtain coating, closed chamber gravure coating, slit nozzle coating, spin coating, slit coating, spray coating, dip coating, hot melt coating, rod coating, applicator, air knife coating, curtain flow coating, offset printing, brush coating, and screen printing.

[0310] The coating resin composition can be applied once or multiple times. In addition, different coating methods can be combined. In order to avoid the mixing of foreign matter, the coating is preferably carried out in an environment with few foreign matter such as a clean room.

[0311] After coating the coating resin composition, the first composition layer 210 can be dried as needed. Drying can be carried out using a drying device such as a hot air furnace, a far infrared furnace, etc. The drying conditions are preferably appropriately set according to the composition of the coating resin composition. If specific examples are listed, the drying temperature is preferably above 50°C, more preferably above 70°C, and particularly preferably above 80°C, preferably below 150°C, more preferably below 130°C, and particularly preferably below 120°C. In addition, the drying time is preferably above 30 seconds, more preferably above 60 seconds, and particularly preferably above 120 seconds, preferably below 60 minutes, more preferably below 20 minutes, and particularly preferably below 5 minutes.

[0312] The formation of the first composition layer 210 can be carried out using, for example, a coating resin sheet comprising a "support" and a "resin composition layer formed by a coating resin composition". If a specific example is given, the first composition layer 210 can be formed on the substrate 300 by laminating the coating resin composition layer of the coating resin sheet on the substrate 300. Lamination is usually performed by pressing the coating resin composition layer of the resin sheet onto the substrate 300 while heating. The lamination is preferably performed by vacuum lamination and under reduced pressure. In addition, before lamination, a preheating treatment of heating the resin sheet and the substrate can be performed as needed.

[0313] The lamination conditions may be, for example, a lamination temperature of 70°C to 140°C and a lamination pressure of 1 kgf / cm 2 ~11kgf / cm 2 (9.8×10 4 N / m 2 ~107.9×10 4 N / m 2 ) and the pressing time is 5 seconds to 300 seconds. In addition, lamination is preferably carried out under reduced pressure with the air pressure set to 20 mmHg (26.7 hPa) or less. Lamination can be carried out intermittently or continuously using a roller.

[0314] The vacuum lamination method can be performed using a commercially available vacuum laminator, such as a vacuum applicator manufactured by Nikko-materials, a vacuum pressure laminator manufactured by Meiki Manufacturing Co., Ltd., a roll dry coater manufactured by Hitachi Industries, and a vacuum laminator manufactured by Hitachi AIC.

[0315] When the first composition layer 210 is formed using a coating resin sheet having a support, the support is usually peeled off at an appropriate time before step (III).

[0316] The first composition layer 210 formed on the substrate 300 in step (I) usually contains a coating resin composition, and preferably contains only a coating resin composition.

[0317] In the method for manufacturing an optical waveguide according to one embodiment of the present invention, after step (I), a step (II) of curing the first composition layer 210 is included. In the step (II), for example, the first composition layer 210 may be subjected to a heat treatment. The heat treatment conditions may be selected according to the type and amount of the resin component in the coating resin composition, and are preferably in the range of 150° C. to 250° C. and 20 minutes to 180 minutes, and more preferably in the range of 160° C. to 230° C. and 30 minutes to 120 minutes. The heat treatment is preferably performed in an inert atmosphere such as a nitrogen atmosphere.

[0318] In addition, the curing of the first composition layer 210 can be performed by exposure treatment. In one example, the specific range of the exposure amount is preferably 10 mJ / cm 2 More preferably, 50 mJ / cm 2 More than, particularly preferably 200mJ / cm 2 More than, preferably 10,000 mJ / cm 2 Less than, more preferably 8,000 mJ / cm 2 Below, more preferably 4,000 mJ / cm 2 Less than, particularly preferably 1,000 mJ / cm 2 In addition, the first composition layer 210 may be cured by combining the exposure treatment and the heat treatment.

[0319] Figure 3 2 is a schematic cross-sectional view for explaining step (II) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. By curing the first composition layer 210 in step (II), Figure 3 As shown, a cured first composition layer 220 is obtained on the substrate 300. The cured first composition layer 220 forms a part of the coating layer 200, and is sometimes referred to as a "lower coating layer" 220 below.

[0320] Figure 4 1 is a schematic cross-sectional view for explaining step (III) of the method for producing an optical waveguide according to one embodiment of the present invention. In the method for producing an optical waveguide according to one embodiment of the present invention, after step (II), Figure 4As shown, the process includes a step (III) of forming a second composition layer 110 including a core resin composition on the lower cladding layer 220 which is the cured first composition layer.

[0321] The method for forming the second composition layer 110 is not particularly limited. For example, the second composition layer 110 can be formed by coating the core resin composition on the lower coating layer 220. From the viewpoint of smooth coating, a varnish-like core resin composition containing a solvent can be prepared and the varnish-like core resin composition can be coated. The coating of the core resin composition can be carried out in the same manner as the coating of the coating resin composition. In addition, after coating the core resin composition, the second composition layer 110 can be dried as needed. The drying of the second composition layer 110 can be carried out by the same method and conditions as the drying of the first composition layer 210.

[0322] The second composition layer 110 can be formed using, for example, a core resin sheet. If a specific example is given, the second composition layer 110 can be formed on the lower coating layer 220 by laminating the resin composition layer of the core resin sheet on the lower coating layer 220. The lamination of the core resin sheet can be performed in the same manner as the lamination of the coating resin sheet. In addition, the support of the core resin sheet is peeled off at an appropriate time before step (V).

[0323] The second composition layer 110 formed on the lower cladding layer 220 in step (III) usually contains a core resin composition, and preferably contains only a core resin composition.

[0324] Figure 5 FIG. 1 is a schematic cross-sectional view for explaining step (IV) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. In the method for manufacturing an optical waveguide according to one embodiment of the present invention, as shown in FIG. Figure 5 As shown, after the step (III), the step (IV) of subjecting the second composition layer 110 to an exposure treatment is included.

[0325] In step (V), a latent image is formed in the second composition layer 110 by exposure treatment. Specifically, in the exposure treatment, light P is selectively irradiated to a specific portion of the second composition layer 110. Therefore, when the exposure treatment is performed, an exposure portion 111 irradiated with light and a non-exposed portion 112 not irradiated with light are provided in the second composition layer 110. Generally, the core resin composition functions as a negative photosensitive resin composition, and therefore, a latent image corresponding to the core layer is formed by the exposure portion 111.

[0326] From the viewpoint of selective exposure, the exposure treatment in step (V) is usually performed using a mask 400. Specifically, in the exposure treatment, the second composition layer 110 is irradiated with light P via a mask 400 having a light-transmitting portion 410 and a light-shielding portion 420. The light P passes through the light-transmitting portion 410 and enters the exposure portion 111, but cannot pass through the light-shielding portion 420, and therefore cannot enter the non-exposure portion 112. Therefore, the exposure portion 111 and the non-exposure portion 112 corresponding to the light-transmitting portion 410 and the light-shielding portion 420 can be provided in the second composition layer 110. The mask 400 can be as follows: Figure 5 The second composition layer 110 may be brought into close contact with the second composition layer 110 as shown (contact exposure method), or exposure may be performed using parallel light without close contact (non-contact exposure method).

[0327] Generally speaking, the light-transmitting portion 410 of the mask 400 is formed in a manner having a planar shape corresponding to the core layer of the optical waveguide. Therefore, the light-shielding portion 420 of the mask 400 is formed in a manner having a planar shape corresponding to the portion of the optical waveguide without the core layer. Unless otherwise specified, the "planar shape" means the shape observed in the thickness direction. Hereinafter, the light-transmitting portion 410 formed in a planar shape corresponding to the core layer is sometimes referred to as a "mask pattern".

[0328] As the light P used in the exposure treatment of step (V), it is preferred to use appropriate active light that is compatible with the composition of the core resin composition. The wavelength of the active light is generally 190nm to 1000nm, preferably 240nm to 550nm, and light of other wavelengths may also be used. Specific examples of active light sources include ultraviolet rays, visible rays, electron beams, X-rays, etc., and ultraviolet rays are particularly preferred. The exposure amount of light P is preferably set in a manner that can form the desired core layer after curing in step (VII). In one example, the specific range of the exposure amount in step (V) is preferably 10mJ / cm 2 More preferably, 50 mJ / cm 2 More than, particularly preferably 200mJ / cm 2 More than, preferably 10,000 mJ / cm 2 Less than, more preferably 8,000 mJ / cm 2 Below, more preferably 4,000 mJ / cm 2 Less than, particularly preferably 1,000 mJ / cm 2 the following.

[0329] When the resin sheet of the present invention is used to form the second composition layer 110, in step (IV), a support (not shown) may be present on the second composition layer 110. When a support is present on the second composition layer 110, exposure may be performed through the support or after peeling off the support.

[0330] The core resin composition generally functions as a negative photosensitive resin composition, and therefore, the solubility in the developer is reduced in the exposed portion 111. On the other hand, the solubility in the developer is high in the non-exposed portion 112. The difference in solubility between the exposed portion 111 and the non-exposed portion 112 is utilized to perform development processing in the subsequent step (VI).

[0331] In the method for producing an optical waveguide according to one embodiment of the present invention, after step (IV) and before step (V), from the viewpoint of curing the second composition layer 110, step (IX) of heating the second composition layer 110 may be included. Through step (IX), the solubility of the exposed portion 111 in the developer can be rapidly reduced. The heating in step (IX) can be performed using a hot plate or an oven. The heating temperature can be, for example, 40° C. to 110° C. In addition, the heating time can be, for example, 30 seconds to 60 minutes.

[0332] Figure 6 Schematic cross-sectional view for explaining step (V) of the method for producing an optical waveguide according to one embodiment of the present invention. The method for producing an optical waveguide according to one embodiment of the present invention includes, after step (IV), a step (V) of developing the second composition layer 110. The latent image formed in step (IV) can be developed by the development. The core resin composition generally functions as a negative photosensitive resin composition. Figure 6 As shown in FIG. 1 , the exposed portion 111 is not removed by the development process, while the unexposed portion 112 (see FIG. 1 ) is not removed by the development process. Figure 5 ) is removed. The exposed portion 111 of the second composition layer 110 remaining after development may have a light-transmitting portion 410 (see Figure 5 ) has the same planar shape as the mask pattern.

[0333] Regarding the developing method, a wet developing method is generally performed in which the second composition layer 110 is brought into contact with a developer. As the developer, an alkaline aqueous solution is generally used.

[0334] As for the alkaline aqueous solution as the developer, for example, an aqueous solution of an alkali metal compound can be mentioned. As the alkali metal compound, for example, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide; alkali metal carbonates or bicarbonates such as sodium carbonate and sodium bicarbonate; alkali metal phosphates such as sodium phosphate and potassium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate, etc. can be mentioned. In addition, as the alkaline aqueous solution, for example, an aqueous solution of an organic base that does not contain metal ions such as tetraalkylammonium hydroxide can be mentioned. The alkaline aqueous solution can be used alone or in combination of two or more. Among them, from the viewpoint of significantly obtaining the effect of the present invention, preferably, an alkali metal carbonate or bicarbonate, more preferably sodium carbonate.

[0335] In order to improve the developing effect, the developer may contain additives such as a surfactant and a defoaming agent as necessary.

[0336] The development time is preferably 10 seconds to 5 minutes. The temperature of the developer during development is not particularly limited, but is preferably 20° C. or higher, preferably 50° C. or lower, and more preferably 40° C. or lower.

[0337] As the developing method, for example, a puddle method, a spray method, an immersion method, a brush coating method, a pat coating method, an ultrasonic method, etc. can be cited. Among them, the spray method is suitable because it improves the definition. When the spray method is used, the spray pressure is preferably 0.05 MPa to 0.3 MPa.

[0338] After development with a developer, the second composition layer 110 may be further rinsed. The rinsing is preferably performed using a solvent different from the developer. For example, the same type of solvent as that contained in the core resin composition or water may be used for rinsing. The rinsing time is preferably 5 seconds to 1 minute.

[0339] After development with a developer, a desmear treatment may be performed to remove non-exposed areas that have not been completely removed by development. The desmear treatment may be performed by various methods known to those skilled in the art used in the production of printed wiring boards.

[0340] In the method for producing an optical waveguide according to one embodiment of the present invention, after step (V), a step (VI) of curing the second composition layer 110 is included. The step (VI) generally includes heat-treating the second composition layer 110. The conditions of the heat treatment can be selected according to the type and amount of the resin component in the core resin composition. For example, the conditions of the heat treatment in step (VI) may be the same as those of the heat treatment of the first composition layer 210 in step (II).

[0341] Figure 71 is a schematic cross-sectional view for explaining step (VI) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. By curing the second composition layer 110 in step (VI), Figure 7 As shown, the core layer 100 as the cured second composition layer can be obtained on the lower cladding layer 220 .

[0342] Figure 8 Schematic cross-sectional view for explaining step (VII) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 8 As shown, the method for manufacturing an optical waveguide according to one embodiment of the present invention includes a step (VII) of forming a third composition layer 230 including a cladding resin composition on the core layer 100 after the step (VI). The third composition layer 230 is generally formed so as to cover all surfaces of the peripheral surface of the core layer 100 that are not in contact with the lower cladding layer 220. Therefore, the third composition layer 230 is formed so as to cover the core layer 100 and is also formed on the lower cladding layer 220.

[0343] There is no particular limitation on the method for forming the third composition layer 230. For example, the third composition layer 230 may be formed by coating the coating resin composition on the core layer 100 (and on the lower coating layer 220 as needed). The coating of the coating resin composition for forming the third composition layer 230 may be carried out in the same manner as the coating of the coating resin composition for forming the first composition layer 210. In addition, after coating the coating resin composition, the third composition layer 230 may be dried as needed. The drying of the third composition layer 230 may be carried out by the same method and conditions as the drying of the first composition layer 210.

[0344] The formation of the third composition layer 230 can also be carried out using, for example, a coating resin sheet. If a specific example is given, the third composition layer 230 can be formed on the core layer 100 by laminating a resin composition layer of a coating resin sheet on the core layer 100 (and the lower coating layer 220 as required). The lamination of the coating resin sheet for forming the third composition layer 230 can be carried out in the same manner as the lamination of the coating resin sheet for forming the first composition layer 210. In the case of forming the third composition layer 230 using a coating resin sheet having a support, the support can be peeled off in any process.

[0345] In step (VII), the third composition layer 230 formed on the core layer 100 usually contains a coating resin composition, and preferably contains only a coating resin composition.

[0346] The method for producing an optical waveguide according to one embodiment of the present invention includes, after step (VII), step (VIII) of curing the third composition layer 230. The curing of the third resin composition layer 230 in step (VIII) can be generally performed in the same manner as the curing of the first composition layer 210.

[0347] Fig. 9 2 is a schematic cross-sectional view for explaining step (VIII) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. By curing the third composition layer 230 in step (VIII), Fig. 9 As shown, a third composition layer 240 can be obtained after solidification on the core layer 100. The solidified third composition layer 240 forms a part of the cladding layer 200, and is sometimes referred to as the "upper cladding layer" 240 below. The cladding layer 200 is formed by the upper cladding layer 240 and the lower cladding layer 220. Therefore, the optical waveguide 10 having the cladding layer 200 including the lower cladding layer 220 and the upper cladding layer 240 and the core layer 100 disposed in the cladding layer 200 can be obtained.

[0348] The method for manufacturing the optical waveguide 10 may further include an optional step in combination with the above-mentioned steps.

[0349] The method for producing the optical waveguide 10 may include, for example, a step of forming a protective layer (not shown). In addition, the method for producing the optical waveguide 10 may include, for example, a step of dicing the produced optical waveguide 10 .

[0350] The method for manufacturing the optical waveguide 10 may repeat the above steps. For example, steps (I) to (VIII) may be repeated to manufacture an optical waveguide having a multilayer structure in which core layers and cladding layers are alternately provided on the substrate 300 in the thickness direction.

[0351] [Photoelectric hybrid substrate and its manufacturing method]

[0352] An optoelectronic hybrid substrate according to one embodiment of the present invention includes the above-mentioned optical waveguide. Generally, the optoelectronic hybrid substrate includes an optical waveguide and a circuit substrate. The circuit substrate may include electronic components and wiring connected to the electronic components. As electronic components, passive components such as capacitors, inductors, resistors, and active components such as semiconductor chips may be cited. In addition, the optical waveguide and the wiring of the circuit substrate may be connected via a photoelectric conversion element. The photoelectric conversion element may be a combination of a light-emitting element (such as a surface-emitting light-emitting diode) that can convert electricity into light and a light-receiving element (such as a photodiode) that can convert light into electricity. Furthermore, the optoelectronic hybrid substrate may include optical elements such as reflectors in order to adjust the optical path.

[0353] As a preferred example of an optoelectronic hybrid substrate, a substrate having a chip formed with an optical integrated circuit on a silicon wafer can be cited. The chip can be expected to be used for early practical application of silicon photonics, for example, its installation in a semiconductor package can be envisioned. The optoelectronic hybrid substrate having the chip has, for example, a circuit substrate, a chip mounted on the circuit substrate, and an optical waveguide. The optical waveguide can be used to connect the wiring of the circuit substrate to the chip, or to connect multiple chips.

[0354] In chips manufactured by silicon photonics, light with wavelengths of 1310nm and 1550nm is often used, with 1310nm being the mainstream (Sho Yoshida, Daisuke Suganuma, Takaaki Ishiba, "Fabrication and Loss Reduction of Single-Mode Polymer Waveguides Based on the Mosquito Method", 28th Spring Lecture Meeting of the Society of Electronic Devices, 2014). Therefore, the optical waveguide is preferably capable of transmitting light of 1310nm and 1550nm or wavelengths close thereto, preferably capable of transmitting light of, for example, wavelengths of 1300nm to 1320nm. The optical waveguide involved in the above-mentioned embodiment is capable of transmitting light of these wavelengths.

[0355] Generally speaking, between single mode and multimode, single mode can achieve faster transmission. Therefore, from the viewpoint of high-speed transmission, as an optical waveguide used for optoelectronic hybrid circuits, a single-mode optical waveguide is preferred. In a single-mode optical waveguide, the width of the core layer is preferably small. For example, it is preferred to form a core layer with a width of less than 10 μm or less than 5 μm. In addition, in the case of applying an optical waveguide to a semiconductor package, from the viewpoint of increasing the design freedom of the package, an optical waveguide having a core layer with such a small width is also preferred. According to the optical waveguide involved in the above-mentioned embodiment, the width of the core layer can be reduced as described above.

[0356] On the other hand, when a plurality of optoelectronic hybrid substrates are connected, these substrates may be connected via optical fibers. For example, a plurality of optoelectronic hybrid substrates may be arranged on a bracket, and these optoelectronic hybrid substrates may be connected to each other using optical fibers. Multimode is the mainstream optical fiber for connecting the substrates. Therefore, from the viewpoint of being able to connect to the optical fiber, a multimode optical waveguide may be used as an optical waveguide arranged on the optoelectronic hybrid substrate.

[0357] From the viewpoint of improving versatility, it is expected that the optical waveguide can be applied in both single-mode and multi-mode. Furthermore, it is expected to reduce the minimum width of the core layer of these optical waveguides and increase the degree of freedom of the line width of the core layer. According to the optical waveguide involved in the above-mentioned embodiment, by using a core resin composition, a fine core can be formed and the generation of surface unevenness of the core can be suppressed, thereby reducing the minimum width of the core layer. In addition, according to the optical waveguide involved in the above-mentioned embodiment, any optical waveguide of single mode and multi-mode can be obtained. Therefore, the optical waveguide involved in the above-mentioned embodiment can be applied to a wide range. Moreover, since it can be applied to a wide range in this way and the transmission loss of light can be suppressed, the optical waveguide involved in the above-mentioned embodiment is suitable for application in optoelectronic hybrid substrates.

[0358] The opto-electric hybrid substrate includes the above-mentioned optical waveguide, and therefore the method for manufacturing the opto-electric hybrid substrate includes the same method as the method for manufacturing the optical waveguide.

[0359] Example

[0360] The present invention is specifically described below with reference to the following examples, but the present invention is not limited to these examples. It should be noted that in the following description, "parts" and "%" indicating amounts refer to "parts by mass" and "% by mass" respectively unless otherwise expressly stated. In addition, the operations described below are performed in an atmosphere at normal temperature and pressure (23° C., 1 atm) unless otherwise expressly stated.

[0361] <Synthesis Example 1: Synthesis of an Acid-Modified Epoxy Acrylate Resin Containing a Naphthol Aralkyl Skeleton>

[0362] 325 parts of an epoxy resin having a naphthol aralkyl skeleton with an epoxy equivalent of 330 g / eq. ("ESN-475V", manufactured by Nippon Steel Chemical Materials Co., Ltd.) were placed in a flask with a gas inlet tube, a stirring device, a cooling tube and a thermometer, and 340 parts of propylene glycol monomethyl ether were added, heated to dissolve, and 0.46 parts of hydroquinone and 1 part of triphenylphosphine were added. The mixture was heated to 95-105°C, 72 parts of acrylic acid were slowly added dropwise, and the reaction was carried out for 16 hours. The reaction product was cooled to 80-90°C, 130 parts of tetrahydrophthalic anhydride were added, the reaction was carried out for 8 hours, and the reaction was allowed to cool. The solvent was removed to obtain an acid-modified epoxy acrylate resin having an acid value of 90 mgKOH / g and a solid content of 70% by mass. The weight average molecular weight was 1000.

[0363] <Manufacturing Example 1: Manufacture of Core Resin Composition>

[0364] 21.5 parts of the naphthol aralkyl skeleton-containing ester-type acid-modified epoxy acrylate resin obtained in Synthesis Example 1, 10 parts of a naphthol aralkyl skeleton epoxy resin ("ESN-475V" manufactured by Nippon Steel Chemical Materials Co., Ltd., epoxy equivalent of about 330 g / eq.), 5 parts of a naphthalene-type tetrafunctional epoxy resin ("HP-4710" manufactured by DIC Corporation, epoxy equivalent of 170 g / eq.), and a photoreactive resin ("DPHA" manufactured by Nippon Kayaku Co., Ltd., diethylenetriamine 12.5 parts of tetraol hexaacrylate), 1.5 parts of a photopolymerization initiator ("Omnirad379EG" manufactured by IGM), 0.2 parts of a curing accelerator (2-phenyl-1-benzyl-1H-imidazole, manufactured by Shikoku Chemical Industry Co., Ltd.), 0.1 parts of a flame retardant (FP-100, manufactured by Fushimi Pharmaceutical Co., Ltd.), 15 parts of methyl ethyl ketone, and 1.5 parts of propylene glycol monomethyl ether are mixed, and a varnish-like core resin composition is prepared using a high-speed rotating mixer.

[0365] <Manufacturing Examples 2 to 14: Manufacture of Core and Covering Resin Compositions>

[0366] The core or covering resin compositions were prepared in the same manner as in Example 1 except that the components were mixed in the blending compositions shown in the following table. It should be noted that in the table, the blending amount of each component is parts by mass and is the actual amount used. Manufacturing Examples 1, 2, and 10 are core resin compositions, and Manufacturing Examples 2 to 9 and 11 to 14 are covering resin compositions.

[0367] [Table 1]

[0368]

[0369] The abbreviations in the table are as follows.

[0370] (A)Ingredients

[0371] Synthesis Example 1: Carboxyl-containing resin synthesized in Synthesis Example 1

[0372] (B) Ingredients

[0373] HP-4710: Naphthalene-based tetrafunctional epoxy resin ("HP-4710" manufactured by DIC Corporation, epoxy equivalent 170 g / eq.)

[0374] ·ESN-475V: Naphthalene-type epoxy resin ("ESN-475V" manufactured by Nippon Steel Chemicals Co., Ltd., epoxy equivalent weight about 330 g / eq.)

[0375] (C) Ingredients

[0376] DPHA: dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., acrylic acid equivalent about 96 g / eq.)

[0377] (D) Ingredients

[0378] Omnirad379EG: a compound represented by the following structure (manufactured by IGM, molecular weight 380.5, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, CAS 119344-86-4)

[0379] [Chemical formula 11]

[0380]

[0381] (E) Ingredients

[0382] FP-100: A compound represented by the following structure (manufactured by Fushimi Pharmaceutical Co., Ltd.)

[0383] [Chemical formula 12]

[0384]

[0385] ·SPS-100: A compound represented by the following structure (manufactured by Otsuka Chemical Co., Ltd.)

[0386] [Chemical formula 13]

[0387]

[0388] SR-3000: A compound represented by the following structure (manufactured by Daihachi Chemical Industry Co., Ltd.)

[0389] [Chemical formula 14]

[0390]

[0391] · PX-200: A compound represented by the following structure (manufactured by Daihachi Chemical Industry Co., Ltd.)

[0392] [Chemical formula 15]

[0393]

[0394] FP-390: A compound represented by the following structure (manufactured by Fushimi Pharmaceutical Co., Ltd.) wherein n represents an integer of 3 to 25.

[0395] [Chemical formula 16]

[0396]

[0397] HCA-HQ: The compound represented by the following structure (manufactured by Sanko Co., Ltd.) was crushed and classified by the following method and used. 50 mg of HCA-HQ powder, 2 g of nonionic dispersant ("T208.5" manufactured by NOF Corporation), and 40 g of pure water were weighed in a vial and dispersed by ultrasonic for 20 minutes. The particle size distribution was measured by batch cell method using a laser diffraction particle size distribution measuring device (manufactured by Horiba, Ltd., LA-950), and the average particle size was calculated. The average particle size was 0.65 μm.

[0398] [Chemical formula 17]

[0399]

[0400] (F)Ingredients

[0401] 1B2PZ: 2-phenyl-1-benzyl-1H-imidazole, manufactured by Shikoku Chemical Industry Co., Ltd.

[0402] (H) Ingredients

[0403] Melamine: Made by Nissan Chemical Co.

[0404] <Production of Core and Covering Resin Sheets>

[0405] A polyethylene terephthalate film ("Lumirror T6AM" manufactured by Toray Industries, Ltd., thickness 38 μm, softening point 130°C) was prepared as a support. The varnish-like resin composition prepared above was uniformly applied to the support using a die coater so that the thickness of the resin composition layer after drying became 5 μm, 6.5 μm, 10 μm, 20 μm and 50 μm, and each resin composition layer was formed by drying at 80°C to 110°C (maximum temperature 110°C) for 7 minutes. Next, a protective film (biaxially stretched polypropylene film, "MA-411" manufactured by Prince F-Tex Co., Ltd.) was arranged on the surface of the resin composition layer and laminated at 80°C to produce a resin sheet having a three-layer structure of support / resin composition layer / protective film.

[0406] <Measurement of Refractive Index of Cured Product of Resin Composition>

[0407] The protective film was peeled off from the resin sheet having a resin composition layer with a thickness of 6.5 μm. Then, the resin sheet was laminated on a silicon wafer at 80°C, and the support was peeled off to form a resin composition layer with a thickness of 6.5 μm on the silicon wafer. Then, a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) was used to expose the resin composition layer at an optimal exposure amount of 5000 mJ. After exposure, a 23°C and 1.0 mass % tetramethylammonium hydroxide aqueous solution as a developer was sprayed onto the resin composition layer at a spray pressure of 0.1 MPa for 30 seconds to perform spray development. After spray development, the resin composition layer was subjected to 3J / cm 2 The sample was irradiated with ultraviolet rays and then heated at 190°C for 90 minutes in a nitrogen atmosphere to obtain a sample formed of a cured product of the resin composition layer. The refractive index (1310 nm) of the obtained sample was measured at room temperature and atmospheric pressure using a 1310 nm laser using a 2010M prism coupler (manufactured by Metricon).

[0408] <Measurement of shrinkage ratio>

[0409] The protective film was peeled off from the resin sheet with a resin composition layer of 10 μm in thickness. A resin sheet was arranged on a 6-inch silicon wafer in such a way that the resin composition layer was in contact with the silicon wafer, and a vacuum laminator (Nikko-Materials "VP160") was used for lamination. The lamination conditions were set to 30 seconds of vacuuming time, 60°C of crimping temperature, 0.3MPa of crimping pressure, and 30 seconds of pressing time. Then, the support was peeled off to obtain a laminate having a silicon wafer and a resin composition layer.

[0410] The resin composition layer of the obtained laminate was exposed to ultraviolet light using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy of 8 to 10 steps of gloss residual steps of a 41-step step exposure meter. The exposure was performed using a quartz glass mask having a mask pattern with an L / S (line width / spacing) of 5μm / 100μm and capable of depicting multiple straight lines with a length of 5cm. In the L / S of the quartz glass mask, the line width is equivalent to the width of the core layer, and the spacing is equivalent to the spacing between the core layers. After exposure, the support was peeled off after standing at room temperature for 30 minutes. For the entire surface of the resin composition layer, a 30°C and 1 mass% sodium carbonate aqueous solution was used as a developer, and spray development was performed at a spray pressure of 0.2MPa for 1 minute. After spray development, 2J / cm 2Irradiate with ultraviolet light. Cut the silicon wafer in a direction perpendicular to the obtained core wire, observe the cross section at this time with a microscope, measure the vertical and horizontal lengths of the rectangular core, and calculate the area (α). Then, put it into a clean oven, raise the temperature from room temperature to 190°C, and after reaching 190°C, perform a heating treatment for 69 minutes to cure the resin composition layer. After the resin composition layer is cured, observe the same cross section, measure the vertical and horizontal lengths of the rectangular core, and calculate the area (β). Based on the calculated α and β, calculate the shrinkage rate c.

[0411] [Mathematical formula 2]

[0412]

[0413] <Example 1>

[0414] (Evaluation of Development Property)

[0415] -Sample preparation-

[0416] For the copper layer of the glass epoxy substrate (copper-clad laminate) having a copper layer of 18 μm thick, a surface treatment agent containing an organic acid (CZ8100, manufactured by Meige Co., Ltd.) was used to perform a roughening treatment to prepare a substrate. Then, the protective film was peeled off from the resin sheet having a resin composition layer with a thickness of 10 μm manufactured using the resin composition of Manufacturing Example 2. The resin sheet was arranged on the copper-clad laminate in such a way that the resin composition layer was in contact with the copper-clad laminate, and laminated using a vacuum laminator ("VP160" manufactured by Nikko-Materials). The lamination conditions were set as follows: vacuuming time of 30 seconds, crimping temperature of 60°C, crimping pressure of 0.3 MPa, and pressing time of 30 seconds. Thereafter, the support was peeled off, and ultraviolet exposure was performed using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy of 8 steps of the gloss residual stage of a 41-step stage exposure meter. After exposure, 2 J / cm 2 Then, the resin composition layer was cured by ultraviolet irradiation. Then, the resin composition layer was placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, the resin composition layer was heated for 90 minutes in a nitrogen atmosphere. The lower coating layer was formed by curing the resin composition layer, and an intermediate laminate I having a copper-clad laminate and a lower coating layer was obtained.

[0417] Next, the protective film is peeled off from the resin sheet with a thickness of 5 μm manufactured using the resin composition of Manufacturing Example 1. The resin sheet is configured on the lower coating layer in a manner that the resin composition layer of the resin sheet contacts the lower coating layer of the intermediate laminate I, and a vacuum laminator (Nikko-Materials "VP160") is used for lamination to form a resin composition layer on the lower coating layer. The lamination conditions are set to: vacuum time 30 seconds, crimping temperature 60 ° C, crimping pressure 0.3MPa, and pressing time 30 seconds. Thus, a laminate having a copper-clad laminate, a lower coating layer and a resin sheet is obtained in sequence. Thereafter, the support is peeled off to expose the resin composition layer.

[0418] A projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) was used to expose the resin composition layer to ultraviolet light using an exposure energy of 8 steps of gloss residual stage steps of a 41-step stage exposure meter. The exposure was performed using a quartz glass mask having a first mask pattern with an L / S (line width / spacing) of 50μm / 50μm and capable of drawing straight lines, and a second mask pattern with an L / S (line width / spacing) of 5μm / 5μm and capable of drawing straight lines. After exposure, the support was peeled off after standing at room temperature for 30 minutes. For the entire surface of the resin composition layer, a 30°C and 1% by mass sodium carbonate aqueous solution was used as a developer and sprayed at a spray pressure of 0.2MPa for 1 minute. After spray development, 2J / cm 2 The sample was irradiated with ultraviolet light and then heated at 190°C for 1 hour in a nitrogen atmosphere to obtain a sample A having a copper-clad laminate, a lower covering layer and a 5 μm thick wire layer (a layer formed by a cured product of the resin composition) in this order.

[0419] The protective film was peeled off from a resin sheet with a thickness of 50 μm manufactured using the resin composition of Manufacturing Example 1. A resin sheet was arranged on the lower coating layer in such a way that the resin composition layer of the resin sheet was in contact with the lower coating layer of the intermediate laminate I, and a vacuum laminator (Nikko-Materials "VP160") was used for lamination to form a resin composition layer on the lower coating layer. The lamination conditions were the same as those for laminating a resin sheet with a thickness of 5 μm on the intermediate laminate I. Thus, a sample B having a copper-clad laminate, a lower coating layer, and a 50 μm line layer (a layer formed by a cured product of the resin composition) was obtained in sequence.

[0420] -Evaluation of Development Properties-

[0421] The obtained samples A and B were observed using a scanning electron microscope (SEM) (magnification 2000 times) to measure the minimum fine line formation width (the width of the smallest line layer among the line layers that can be formed). The aspect ratio was calculated by dividing the thickness of the line layer by the minimum fine line formation width, and the developability was evaluated according to the following evaluation criteria. The line width represents the width of the line layer.

[0422] ○: A line having a thickness of 5 μm and a line width of 5 μm can be formed, and a line having a thickness of 50 μm and a line width of 50 μm can be formed.

[0423] Δ: Neither a line having a thickness of 5 μm and a line width of 5 μm nor a line having a thickness of 50 μm and a line width of 50 μm could be formed.

[0424] ×: A line having a thickness of 5 μm and a line width of 5 μm could not be formed, and a line having a thickness of 50 μm and a line width of 50 μm could not be formed.

[0425] (Evaluation of flame retardancy)

[0426] - Fabrication of test substrates -

[0427] 1. Formation of the lower coating layer

[0428] The protective film is peeled off from the resin sheet having a resin composition layer with a thickness of 20 μm manufactured using the resin composition of Manufacturing Example 2. The resin sheet is arranged on the copper-clad laminate in such a manner that the resin composition layer is in contact with the copper-clad laminate, and laminated using a vacuum laminator ("VP160" manufactured by Nikko-Materials). The lamination conditions are set as follows: vacuuming time 30 seconds, crimping temperature 60°C, crimping pressure 0.3 MPa, and pressing time 30 seconds. Thereafter, the support is peeled off, and ultraviolet exposure is performed using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy of 8 steps of gloss residual steps of a 41-step stage exposure meter. After exposure, 2 J / cm 2 The intermediate laminate II was placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, it was heated for 90 minutes in a nitrogen atmosphere to cure the resin composition layer. The lower coating layer was formed by curing the resin composition layer, and an intermediate laminate II having a copper-clad laminate and a lower coating layer was obtained.

[0429] 2. Formation of the core layer

[0430] The protective film was peeled off from a resin sheet having a resin composition layer with a thickness of 5 μm manufactured using the resin composition of Manufacturing Example 1. A resin sheet was arranged on the surface of the lower coating layer of the intermediate laminate II in such a manner that the resin composition layer was in contact with the lower coating layer of the intermediate laminate II, and laminated using a vacuum laminator (Nikko-Materials "VP160"). The lamination conditions were set as follows: vacuuming time of 30 seconds, crimping temperature of 60°C, crimping pressure of 0.3 MPa, and pressing time of 30 seconds. Thereafter, the support was peeled off, and ultraviolet exposure was performed using a projection exposure device (USHIO Electric Co., Ltd. "UFX-2240") using an exposure energy with a gloss residual step number of 8 steps of a 41-step stage exposure meter. Exposure was performed using a quartz glass mask having a mask pattern with an L / S (line width / spacing) of 5 μm / 100 μm and capable of depicting multiple straight lines with a length of 5 cm. In the L / S of the quartz glass mask, the line width is equivalent to the width of the core layer, and the spacing is equivalent to the spacing between the core layers. After exposure, the support was peeled off after standing at room temperature for 30 minutes. For the entire surface of the resin composition layer, a 23°C and 1 mass% tetramethylammonium hydroxide aqueous solution was sprayed at a spray pressure of 0.2 MPa for 1 minute. After spray development, 2 J / cm 2 Then, the film was placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, a heat treatment was performed for 90 minutes in a nitrogen atmosphere to cure the resin composition layer.

[0431] The core layer is formed by curing the resin composition layer, and an intermediate laminate III including a copper-clad laminate, a lower cladding layer, and a core layer in this order is obtained.

[0432] 3. Formation of the upper coating layer

[0433] The protective film is peeled off from the resin sheet having a resin composition layer with a thickness of 20 μm manufactured using the resin composition of Manufacturing Example 2. The resin sheet is arranged on the core layer of the intermediate laminate III in such a manner that the resin composition layer is in contact with the core layer, and laminated using a batch vacuum pressurizing laminator (manufactured by Nikko-Materials, a 2-stage build-up laminator, CVP700). The lamination conditions are set as follows: vacuuming time 30 seconds, crimping temperature 60°C, crimping pressure 0.3 MPa, and pressing time 30 seconds. Thereafter, the support is peeled off, and ultraviolet exposure is performed using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy of 8 steps of gloss residual steps of a 41-step stage exposure meter. After exposure, 2 J / cm 2Then, it was placed in a clean oven and heated from room temperature to 170°C. After reaching 170°C, it was heated for 60 minutes in a nitrogen atmosphere to cure the resin composition layer. The upper coating layer was formed by curing the resin composition layer, and a sample laminate having a copper-clad laminate, a lower coating layer, a core layer, and an upper coating layer was obtained in sequence.

[0434] In the sample laminate, the combination of the lower cladding layer and the upper cladding layer constitutes the cladding layer. Therefore, an optical waveguide including the cladding layer and the core layer located in the cladding layer is obtained. In addition, in the sample laminate, the core layer has a linear pattern with a length of 5 cm corresponding to the mask pattern of the quartz glass mask, and the width (line width) and spacing (pitch) of the core layer contained in these patterns are consistent with the width (line width) and spacing (pitch) of the mask pattern. The obtained laminate (thickness of about 360μm) was cut to form a size of 12.7mm×127mm and the edge was formed to 1.27mm. After being treated in an oven at 70±1℃ for 168 hours, it was cooled in a dryer for more than 4 hours to obtain a test piece.

[0435] According to the flame retardant test UL-94V, the burner is moved to the bottom of the test piece, the flame is in contact with the center of the lower end of the test piece for 10 seconds, and the burning time thereafter is measured. The flame contact is performed for another 10 seconds, and the burning time thereafter is measured. This is repeated 5 times and evaluated according to the following criteria.

[0436] ○: No burning material falls, the test piece is completely burned, and the burning time of the test piece is less than 50 seconds.

[0437] △: There is no falling of burning material, the test piece is completely burned, and the burning time of the test piece is 50 seconds or more and 250 seconds or less.

[0438] ×: The burning material fell, the test piece was completely burned, or the burning time of the test piece exceeded 250 seconds.

[0439] (Measurement of optical transmission loss)

[0440] - Fabrication of test substrates -

[0441] 1. Formation of the lower coating layer

[0442] The protective film is peeled off from the resin sheet having a resin composition layer with a thickness of 10 μm manufactured using the resin composition of Manufacturing Example 2. The resin sheet is arranged on the copper-clad laminate in such a manner that the resin composition layer is in contact with the copper-clad laminate, and laminated using a vacuum laminator ("VP160" manufactured by Nikko-Materials). The lamination conditions are set as follows: vacuuming time 30 seconds, crimping temperature 60°C, crimping pressure 0.3 MPa, and pressing time 30 seconds. Thereafter, the support is peeled off, and ultraviolet exposure is performed using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy of 8 steps of gloss residual steps of a 41-step stage exposure meter. After exposure, 2 J / cm 2 The intermediate laminate II was placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, it was heated for 90 minutes in a nitrogen atmosphere to cure the resin composition layer. The lower coating layer was formed by curing the resin composition layer, and an intermediate laminate II having a copper-clad laminate and a lower coating layer was obtained.

[0443] 2. Formation of the core layer

[0444] The protective film was peeled off from the resin sheet having a resin composition layer with a thickness of 5 μm manufactured using the resin composition of Manufacturing Example 1. The resin sheet was arranged on the surface of the lower coating layer of the intermediate laminate II in such a way that the resin composition layer was in contact with the lower coating layer of the intermediate laminate II, and laminated using a vacuum laminator ("VP160" manufactured by Nikko-Materials). The lamination conditions were set as follows: vacuuming time of 30 seconds, crimping temperature of 60°C, crimping pressure of 0.3 MPa, and pressing time of 30 seconds. Thereafter, the support was peeled off, and ultraviolet exposure was performed using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy with a gloss residual step number of 8 steps of a 41-step stage exposure meter. Exposure was performed using a quartz glass mask having a mask pattern with an L / S (line width / spacing) of 5 μm / 100 μm and capable of depicting multiple straight lines with a length of 5 cm. In the L / S of the quartz glass mask, the line width is equivalent to the width of the core layer, and the spacing is equivalent to the spacing between the core layers. After exposure, the support was peeled off after standing at room temperature for 30 minutes. For the entire surface of the resin composition layer, a 23°C and 1 mass% tetramethylammonium hydroxide aqueous solution was sprayed at a spray pressure of 0.2 MPa for 1 minute. After spray development, 2 J / cm 2 Then, the film was placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, a heat treatment was performed for 90 minutes in a nitrogen atmosphere to cure the resin composition layer.

[0445] The core layer is formed by curing the resin composition layer, and an intermediate laminate III including a copper-clad laminate, a lower cladding layer, and a core layer in this order is obtained.

[0446] 3. Formation of the upper coating layer

[0447] The protective film is peeled off from the resin sheet having a resin composition layer with a thickness of 20 μm manufactured using the resin composition of Manufacturing Example 2. The resin sheet is arranged on the core layer of the intermediate laminate III in such a manner that the resin composition layer is in contact with the core layer, and laminated using a batch vacuum pressurizing laminator (manufactured by Nikko-Materials, a 2-stage build-up laminator, CVP700). The lamination conditions are set as follows: vacuuming time 30 seconds, crimping temperature 60°C, crimping pressure 0.3 MPa, and pressing time 30 seconds. Thereafter, the support is peeled off, and ultraviolet exposure is performed using a projection exposure device ("UFX-2240" manufactured by USHIO Electric Co., Ltd.) using an exposure energy of 8 steps of gloss residual steps of a 41-step stage exposure meter. After exposure, 2 J / cm 2 Then, it was placed in a clean oven and heated from room temperature to 170°C. After reaching 170°C, it was heated for 60 minutes in a nitrogen atmosphere to cure the resin composition layer. The upper coating layer was formed by curing the resin composition layer, and a sample laminate having a copper-clad laminate, a lower coating layer, a core layer, and an upper coating layer was obtained in sequence.

[0448] In the sample laminate, the combination of the lower cladding layer and the upper cladding layer constitutes a cladding layer. Therefore, an optical waveguide including the cladding layer and the core layer located in the cladding layer is obtained. In addition, in the sample laminate, the core layer has a linear pattern with a length of 5 cm corresponding to the mask pattern of the quartz glass mask, and the width (line width) and interval (pitch) of the core layer included in these patterns are consistent with the width (line width) and interval (pitch) of the mask pattern.

[0449] The core layer portion having a 5 cm straight line pattern and the surrounding cladding layer were cut from the sample laminate produced using the resin sheets of the examples and comparative examples to obtain a test substrate having a light transmission path. The cutting conditions were as follows.

[0450] Cutting device: DAD3221 (manufactured by DISCO)

[0451] Blade: ZH14-SD4000-VI-50

[0452] ·Axis speed: 30K / min

[0453] Cutting speed: 5mm / sec

[0454] Blade height: 0.060mm

[0455] Dicing tape: T-80W (made by DENKA, 80 umt)

[0456] (Measurement of light transmission loss in optical systems for calibration)

[0457] The transmission loss of the optical system obtained by removing the test substrate and the light collecting module from the optical system for measuring the transmission loss of the test substrate described later was measured. That is, using an anti-vibration table covered with a black curtain, a light source (1310 nm light source, "LPSC-1310-FC" manufactured by THORLABS) and an optical receiver (optical power meter "N7742" manufactured by Keysight) were connected via an optical fiber (incident fiber) to obtain an optical system for calibration. The light source was made to emit light, and the intensity of the light entering the optical receiver was measured using the optical receiver to measure the loss of the optical system for calibration.

[0458] (Measurement of optical transmission loss)

[0459] A test substrate is set on an anti-vibration table covered with a black curtain. A light collecting module (numerical aperture of 0.18) is connected to one end (incident end) of the optical waveguide of the test substrate, and the light collecting module is further connected to a light source (1310nm light source, "LPSC-1310-FC" manufactured by THORLABS) via an optical fiber (incident fiber). In addition, another light collecting module (numerical aperture of 0.18) is connected to the other end (exit end) of the optical waveguide of the test substrate, and the light collecting module is further connected to an optical receiver (optical power meter "N7742" manufactured by Keysight) via an optical fiber (exit fiber). Through the above operation, an optical system is obtained in which the light emitted by the light source passes through the optical fiber (incident fiber), light collecting module, optical waveguide, light collecting module and optical fiber (exit fiber) in sequence and enters the optical receiver. Hereinafter, this optical system is sometimes referred to as a sample optical system. The light source is made to emit light, and the intensity of the light entering the optical receiver is measured using a light receiver to measure the loss of the sample optical system.

[0460] The loss of the optical system for correction is subtracted from the loss of the sample optical system to obtain the loss of the optical waveguide included in the test substrate.

[0461] (Measurement of light transmission loss (dB / cm) of optical waveguide before high temperature storage test (HTS test))

[0462] After the loss measurement of the optical waveguide having a core layer with a linear pattern of 5 cm in length was completed, the length was cut to 4 cm and the same measurement was performed. Then, the length was further cut to 3 cm and the same measurement was performed, and the measurement values ​​were calculated for the optical waveguide of 5 cm in length, the optical waveguide of 4 cm in length, and the optical waveguide of 3 cm in length. Moreover, the measurement results were plotted into a coordinate system with the length of the optical waveguide as the horizontal axis and the loss of the optical waveguide as the vertical axis, and the coordinates of the three points representing the measurement results were obtained. The approximate straight line of the three points was calculated by the least square method, and the slope of the approximate straight line was obtained as the loss per unit distance of the optical waveguide (light transmission loss), and the evaluation was performed using the following evaluation criteria.

[0463] ◎: Loss value is less than 0.4dB / cm

[0464] ○: Loss value is less than 0.5dB / cm

[0465] △: Loss value is less than 0.7dB / cm

[0466] ×: Loss value is less than 1.0dB / cm

[0467] (Measurement of light transmission loss (dB / cm) of optical waveguide after high temperature storage test (HTS test))

[0468] A test substrate is prepared separately from the test substrate used above, and is placed in an oven heated to 150°C for 1000 hours. The same operation is performed to calculate the value of the transmission loss after the heat resistance test, and the rate of change (%) of the calculated value of the light transmission loss after the heat resistance test relative to the value of the light transmission loss before the test is calculated, and evaluated using the following evaluation criteria.

[0469] ◎: Change rate is less than 15%

[0470] 0: Change rate is less than 20%

[0471] △: Change rate is 20% or more and less than 30%

[0472] ×: Change rate is 30% or more

[0473] <Measurement of Numerical Aperture (NA)>

[0474] The numerical aperture (NA) of the optical waveguide is obtained by the following formula (1). In formula (1), n core represents the refractive index of the cured product of the core resin composition, n clad It represents the refractive index of the cured product of the coating resin composition.

[0475] [Mathematical formula 3]

[0476]

[0477] <Measurement of difference in shrinkage>

[0478] The difference between the shrinkage rate of the core layer resin composition and the shrinkage rate of the cladding layer resin composition (shrinkage rate of the cladding layer resin composition - shrinkage rate of the core layer resin composition) was calculated, and the absolute value was calculated.

[0479] <Examples 2 to 10, Comparative Examples 1 to 3>

[0480] Developability, flame retardancy, light transmission loss, light transmission loss after a heat resistance test, and the like were measured in the same manner as in Example 1 except that the core layer and the cladding layer were produced using resin sheets produced using the resin compositions of the production examples shown in the following tables.

[0481] [Table 2]

[0482]

[0483] [Explanation of Symbols]

[0484] 10. Optical waveguide

[0485] 100 Core

[0486] 110 Second composition layer

[0487] 111 Exposure Department

[0488] 112 Non-exposure Department

[0489] 200 Coating

[0490] 210 First composite layer

[0491] 220 First composition layer after curing (lower coating layer)

[0492] 230 Third Composition Layer

[0493] 240 The third composition layer after curing (upper coating layer)

[0494] 300 Base Material

[0495] 400 Mask

[0496] 410 light-transmitting part

[0497] 420 shading part

Claims

1. A photosensitive resin composition kit comprising a core resin composition and a coating resin composition, wherein: The core resin composition and the covering resin composition each contain: (A) carboxyl-containing resins, (B) Epoxy resin, (C) Photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds, The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

2. The photosensitive resin composition set according to claim 1, wherein: The phosphate compound in the component (E) is any one of a compound represented by the following formula (E-1) and a compound represented by the following formula (E-2), [Chemical formula 1] In formula (E-1), R 1 ~R 20 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and W 1 represents a group represented by formula (E-1a) or a group represented by formula (E-1b), In formula (E-1b), R represents an oxygen atom or a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, In formula (E-2), R 21 ~R 28 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and R 29 It represents a (meth)acryloyl group, an oxygen atom, a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or a monovalent group consisting of a combination thereof.

3. The photosensitive resin composition set according to claim 1, wherein: The phosphazene compound in the component (E) is a compound represented by the following formula (E-3): [Chemical formula 2] In formula (E-3), R 31 and R 32 Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 6 carbon atoms which may have a substituent; n represents an integer of 3 to 25; and m1 and m2 each independently represent an integer of 0 to 5.

4. The photosensitive resin composition set according to claim 1, wherein When the nonvolatile component of the core resin composition is 100 mass %, the content of phosphorus atoms in the core resin composition is 0.01 mass % or more and 10 mass % or less.

5. The photosensitive resin composition kit according to claim 1, wherein: When the nonvolatile component of the coating resin composition is 100 mass %, the content of phosphorus atoms in the coating resin composition is 0.01 mass % or more and 10 mass % or less.

6. The photosensitive resin composition kit according to claim 1, wherein The component (A) contains at least one of an aralkyl type resin, a naphthol aralkyl type resin, and a Cardo type resin.

7. The photosensitive resin composition kit according to claim 1, wherein: The content of the component (A) is represented by A core , the content of component (B) is set to B core When A core / B core The content of the component (A) is 0.3 or more and 5 or less, the content of the component (B) is 100% by mass of the nonvolatile component of the core resin composition, and the content of the component (A) is 100% by mass of the nonvolatile component of the core resin composition.

8. The photosensitive resin composition kit according to claim 1, wherein The content of the component (A) is represented by A core , the content of component (C) is C core When A core / C core The content of the component (A) is 0.1 to 3, the content of the component (C) is 100% by mass of the nonvolatile component of the core resin composition, and the content of the component (A) is 100% by mass of the nonvolatile component of the core resin composition.

9. The photosensitive resin composition kit according to claim 1, wherein: The content of the component (A) is represented by A clad , the content of component (B) is set to B clad When A clad / B clad The content of the component (A) is 0.3 or more and 5 or less, the content of the component (B) is 100% by mass of the nonvolatile component of the coating resin composition.

10. The photosensitive resin composition kit according to claim 1, wherein The content of the component (A) is represented by A clad , the content of component (C) is C clad When A clad / C clad The content of the component (A) is 0.1 to 3, the content of the component (C) is 100% by mass of the nonvolatile component of the coating resin composition.

11. The photosensitive resin composition kit according to claim 1, which is a photosensitive resin composition kit for producing an optical waveguide. 12 . The photosensitive resin composition kit according to claim 1 , which is a photosensitive resin composition kit for producing an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm.

13. The photosensitive resin composition kit according to claim 1, which is a photosensitive resin composition kit for producing a single-mode optical waveguide.

14. A photosensitive resin sheet set comprising a core resin sheet and a covering resin sheet, wherein: The core resin sheet comprises a resin composition layer comprising the core resin composition in the photosensitive resin composition set according to any one of claims 1 to 13, The coating resin sheet comprises a resin composition layer containing the coating resin composition in the photosensitive resin composition set according to any one of claims 1 to 13.

15. An optical waveguide comprising a core layer and a cladding layer, wherein: The core layer comprises a cured product of a core resin composition, wherein the core resin composition comprises: (A) carboxyl-containing resins, (B) Epoxy resin, (C) Photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds, The coating layer comprises a cured product of a coating resin composition, wherein the coating resin composition comprises: (A) carboxyl-containing resins, (B) Epoxy resin, (C) Photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds, The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

16. An optoelectronic hybrid substrate comprising the optical waveguide according to claim 15.

17. A method for manufacturing an optical waveguide, comprising: a step of forming a first composition layer including a coating resin composition, a step of curing the first composition layer, forming a second composition layer including a core resin composition on the first composition layer, a step of subjecting the second composition layer to an exposure treatment, a step of developing the second composition layer, a step of curing the second composition layer, forming a third composition layer comprising a coating resin composition on the second composition layer, and a step of curing the third composition layer, in, The core resin composition and the covering resin composition each contain: (A) carboxyl-containing resins, (B) Epoxy resin, (C) Photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds, The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

18. A method for manufacturing an optoelectronic hybrid substrate, comprising: a step of forming a first composition layer including a coating resin composition, a step of curing the first composition layer, forming a second composition layer including a core resin composition on the first composition layer, a step of subjecting the second composition layer to an exposure treatment, a step of developing the second composition layer, a step of curing the second composition layer, forming a third composition layer comprising a coating resin composition on the second composition layer, and a step of curing the third composition layer, in, The core resin composition and the covering resin composition each contain: (A) carboxyl-containing resins, (B) Epoxy resin, (C) Photocurable resin, (D) a photopolymerization initiator, and (E) one or more flame retardants selected from phosphate compounds and phosphazene compounds, The content (mass %) of the component (E) in the coating resin composition is referred to as E clad , the content (mass %) of the component (E) in the core resin composition is referred to as E core When E clad -E core Satisfying 0.6 or more and 12 or less, the content (mass %) of the component (E) in the coating resin composition is the content when the non-volatile component of the coating resin composition is set to 100 mass %, and the content (mass %) of the component (E) in the core resin composition is the content when the non-volatile component of the core resin composition is set to 100 mass %.

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