JP2017138495A - Method for producing optical waveguide using photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an optical waveguide excellent in transparency (optical propagation properties) at a wavelength of 850 nm without lowering productivity.SOLUTION: There is provided a method for producing an optical waveguide that is formed from a lower clad layer 4, a core portion 2 and an upper clad layer 3, which includes (I) a step of laminating a photosensitive resin layer formed from a photosensitive resin composition on the core portion, (II) a step of exposing a desired pattern with light and (III) a step of developing the exposed pattern using an alkaline developing liquid, where the photosensitive resin composition is used in which a degree of swelling of the photosensitive resin layer in the alkaline developing liquid is 10 mass% or less; and the photosensitive resin layer formed from the photosensitive resin composition is preferably a photosensitive resin composition which contains (A) a compound having an acidic group, (B) a compound having a polymerizable group, (C) a photopolymerization initiator and (D) a chain transfer agent.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing an optical waveguide, and in particular, it is excellent in transparency at a wavelength of 850 nm (low light propagation loss), and is a photosensitive resin composition comprising a photosensitive resin composition that can easily form a desired pattern by a known photolithography method. The present invention relates to a method for manufacturing an optical waveguide using a resin layer.

  In recent years, in high-speed and high-density signal transmission between electronic devices and between wiring boards, signal transmission interference and attenuation are barriers in conventional transmission using electric wiring, and the limits of high-speed and high-density have begun to appear. In order to overcome this, a technique for connecting between electronic elements and wiring boards with light, so-called optical interconnection, has been studied. As an optical transmission line, polymer optical waveguides are attracting attention because they are easy to process, have a high degree of freedom in forming wiring, and can be densified.

  As a form of the polymer optical waveguide, a type that is prepared on a glass epoxy resin substrate that is assumed to be applied to an opto-electric hybrid board or a flexible type that does not have a rigid support substrate that is assumed to be connected between boards is considered suitable.

Polymer optical waveguides are required to have high transparency (low light propagation loss) and ease of processing from the viewpoint of productivity from the viewpoints of the environment in which the equipment is used, component mounting, and the like.
As a resin composition capable of forming such an optical waveguide, Patent Document 1 discloses a cationic curable resin including a radical copolymer composed of a oxetane ring structure-containing (meth) acryloyl compound and a radical polymerizable compound having an acidic group. A composition is disclosed.
Patent Document 2 discloses a resin composition for an optical material using an alkali-soluble epoxy (meth) acrylate having a urethane skeleton in the main chain as a resin composition capable of forming an optical waveguide having excellent transparency and heat resistance. It is disclosed.

  In Patent Documents 1 and 2, a method of forming a core pattern by exposure / development is used as one method of forming an optical waveguide simply and with high accuracy. Here, the exposure process is a process in which the photosensitive resin in the light irradiation part is three-dimensionally cross-linked and insolubilized. It is a step of dissolving and removing in (1).

  In the optical waveguide forming material used in Patent Documents 1 and 2, a carboxyl group is introduced in order to make it soluble in an alkaline developer. Therefore, even in a core pattern insolubilized by exposure, an acidic functional group Is neutralized with an alkaline developer to form a salt. In particular, when an alkaline developer containing an alkali metal compound such as sodium carbonate, potassium carbonate, sodium hydroxide, or potassium hydroxide is used, the produced monovalent salt tends to be chemically unstable.

  The core pattern in which the unstable salt remains is not preferable from the viewpoint of transparency (light propagation loss) because the inside of the core pattern has a non-uniform structure, and is also not preferable from the viewpoint of the reliability of the optical waveguide.

  A method of adding a step of returning the monovalent salt to the original acidic functional group by washing with an acidic aqueous solution after development has also been proposed (Patent Document 3). This method can be suitably used as a method for ensuring the reliability of the optical waveguide.

  Although the reliability of the optical waveguide can be ensured by using this method, the number of steps in manufacturing the optical waveguide increases, which causes problems such as an increase in cost and a decrease in productivity.

JP 2014-59505 A JP 2013-119605 A Japanese Patent No. 5433959

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an optical waveguide excellent in transparency (light propagation property) at a wavelength of 850 nm without reducing productivity. is there.

  As a result of intensive studies, the present inventors use a resin having a degree of swelling of 10% by mass or less in an alkaline aqueous solution because the resin layer used in the core portion of the optical waveguide contains a chain transfer agent. Thus, it was found that an optical waveguide exhibiting high light propagation property (low light propagation loss) at a wavelength of 850 nm can be obtained without using the method proposed in Patent Document 3.

That is, the present invention relates to the following [1] to [6].
[1] An optical waveguide composed of a lower clad layer, a core part, and an upper clad layer, wherein the core part (I) laminates a photosensitive resin layer made of a photosensitive resin composition, (II) a desired pattern A photosensitive resin composition in which the swelling degree of the photosensitive resin layer in the alkaline developer is 10% by mass or less. Manufacturing method of optical waveguide.
[2] The method for producing an optical waveguide according to the above [1], wherein the alkaline developer is an aqueous solution containing an alkali metal.
[3] The photosensitive resin layer comprising the photosensitive resin composition comprises (A) a compound having an acidic group, (B) a compound having a polymerizable group, (C) a photopolymerization initiator, and (D) a chain transfer agent. The manufacturing method of the optical waveguide as described in said [1] or [2] which consists of a resin composition containing this.
[4] The method for producing an optical waveguide according to [3], wherein the (C) photopolymerization initiator is a photoradical initiator.
[5] The method for producing an optical waveguide according to the above [3] or [4], wherein the (D) chain transfer agent is a compound containing a sulfur atom.
[6] The method for manufacturing an optical waveguide according to any one of [1] to [5], wherein the light propagation loss is 0.2 dB / cm or less.

  According to the method for producing an optical waveguide of the present invention, it is possible to process by photolithography using an alkaline aqueous solution containing an alkali metal without reducing productivity, and excellent in transparency and light propagation at a wavelength of 850 nm. An optical waveguide can be provided.

It is sectional drawing explaining the form of the optical waveguide which concerns on this invention.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. can do. In the present specification, (meth) acrylate means acrylate or methacrylate.

[Photosensitive resin composition]
The photosensitive resin composition for an optical waveguide used in the present invention comprises (A) a compound having an acidic group (hereinafter also referred to as “component (A)”), (B) a compound having a polymerizable group (hereinafter referred to as “(B ) Component ”), (C) a photopolymerization initiator (hereinafter also referred to as“ (C) component ”), and (D) a chain transfer agent (hereinafter also referred to as“ (D) component ”). It is a resin composition, wherein (C) the photopolymerization initiator is a photo radical initiator, and (D) the chain transfer agent is preferably a photosensitive resin composition containing a compound containing a sulfur atom.
The photosensitive resin composition used in the present invention is cured by irradiation with actinic rays, and may be subjected to heat treatment as necessary.

<(A) Compound having acidic group (component (A))>
The photosensitive resin composition used by this invention contains the compound which has an acidic group as (A) component.
Hereinafter, (A) the acidic group-containing compound will be described.

  Examples of the acidic group include a carboxy group, a phenolic hydroxyl group, a sulfoxy group, and a phosphonooxy group. Among these, a carboxy group is preferable from the viewpoints of transparency, heat resistance, and storage stability.

  As the component (A) having a carboxy group, a copolymer of a compound having a carboxy group and an ethylenically unsaturated group in the molecule and a compound other than the above having no carboxy group and having an ethylenically unsaturated group, An acid-modified epoxy (meth) acrylate compound obtained by reacting an epoxy (meth) acrylate compound having two or more hydroxyl groups in the molecule with a carboxylic acid anhydride, an epoxy (meth) acrylate having two or more hydroxyl groups in the molecule Examples thereof include an epoxy (meth) acrylate resin containing a urethane bond obtained by reacting a compound with a diisocyanate compound and a diol compound having a carboxy group in the molecule. Among them, it is preferable to use an epoxy (meth) acrylate resin having a urethane bond from the viewpoint of developability, transparency, heat resistance, and the like.

  The compound (A) having an acidic group may further have a polymerizable group in the molecule. Here, the polymerizable group means a functional group such as an ethylenically unsaturated group, an epoxy group, or an oxetanyl group that undergoes a polymerization reaction by heating or irradiation with actinic rays. Especially, it is preferable that a polymeric group is an ethylenically unsaturated group from a viewpoint of reactivity or the intensity | strength of hardened | cured material.

  Hereinafter, as an example, an epoxy (meth) acrylate resin having a carboxy group and a urethane bond in the molecule (hereinafter also referred to as “carboxy group-containing urethane / epoxy (meth) acrylate resin”) will be described.

As described above, the carboxy group-containing urethane / epoxy (meth) acrylate resin is an epoxy (meth) acrylate compound having two or more hydroxyl groups in the molecule (hereinafter also referred to as “raw material epoxy (meth) acrylate”), a diisocyanate compound. (Hereinafter also referred to as “raw material diisocyanate”) and a diol compound having a carboxy group in the molecule (hereinafter also referred to as “raw material diol”).
Hereinafter, each raw material and manufacturing method will be described in detail.

[Epoxy (meth) acrylate compound (raw material epoxy (meth) acrylate)]
As said raw material epoxy (meth) acrylate, if it is an epoxy (meth) acrylate compound which has two or more hydroxyl groups in a molecule | numerator, it can be especially used without a restriction | limiting.
Specific examples include compounds having two or more epoxy groups in the molecule (hereinafter also referred to as raw material epoxy compounds), acrylic acid, methacrylic acid, and derivatives thereof having a carboxy group (hereinafter referred to as “(meth)”. And compounds obtained by reacting with an "acrylic acid compound").
That is, by reacting an epoxy group of a compound having two or more epoxy groups in the molecule with a carboxy group of a (meth) acrylic acid compound, a hydroxyl group is generated by ring opening of the epoxy group. An epoxy (meth) acrylate compound having at least two hydroxyl groups and two or more ethylenically unsaturated groups derived from a (meth) acrylic acid compound is obtained.

  Examples of the compound having two or more epoxy groups in the molecule include bisphenol A type epoxy resin, bisphenol A novolac type epoxy resin and the like having an bisphenol A type skeleton, bisphenol F type epoxy resin, bisphenol F A bisphenol skeleton such as an epoxy compound having a bisphenol F skeleton in a main skeleton such as a novolak epoxy resin, a bisphenol S epoxy resin, an epoxy compound having a bibisphenol S skeleton in a main skeleton such as a bisphenol S novolac epoxy resin, etc. Epoxy compound having: Novolak type such as phenol novolak type epoxy resin, cresol novolak type epoxy resin, aralkyl novolak type epoxy resin, and various bisphenol novolak type epoxy resins Epoxy compounds; naphthalene, an epoxy compound having a polycyclic aromatic group fluorene, epoxy compounds having one or more selected from cyclic alkyl group and a linear alkyl group.

  As such an epoxy (meth) acrylate compound, for example, a compound represented by the following general formula (1) is preferably exemplified.

（一般式（１）中、Ｒ^１１は前記分子内に２つ以上のエポキシ基を有する化合物の２価の残基を示し、Ｒ^１３は水素原子又はメチル基を示す。
なお、残基とは、原料成分から結合に供された官能基を除いた部分の構造をいう。）

(In the general formula (1), R ¹¹ represents a divalent residue of a compound having two or more epoxy groups in the molecule, and R ¹³ represents a hydrogen atom or a methyl group.
In addition, a residue means the structure of the part remove | excluding the functional group used for the coupling | bonding from the raw material component. )

  These epoxy (meth) acrylate compounds may be used alone or in combination of two or more.

[Diisocyanate compound (raw diisocyanate)]
The raw material diisocyanate can be used without particular limitation as long as it is a compound having two or more isocyanato groups.
Specific examples of the diisocyanate compound include aromatic diisocyanate compounds such as phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate; hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, arylene. Known diisocyanate compounds such as aliphatic diisocyanate compounds such as sulfone ether diisocyanate, allyl cyanide diisocyanate, N-acyl diisocyanate, trimethylhexamethylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, norbornene diisocyanate methyl, and the like can be mentioned.
These diisocyanate compounds may be used alone or in combination of two or more.

[Diol compound (raw diol)]
As said raw material diol, it is a diol compound which has a carboxy group, and if it is a compound which has 2 or more types of 1 or more types of hydroxyl groups chosen from alcoholic hydroxyl group and phenolic hydroxyl group in a molecule | numerator, it can use without a restriction | limiting especially. In particular, from the viewpoint of transparency, it preferably has an alcoholic hydroxyl group.
Such a diol compound may be an aliphatic diol compound having a carboxy group, may be two alcoholic hydroxyl groups, may be an aliphatic diol compound having one carboxy group, and has two methylol groups. And an aliphatic diol compound having one carboxy group, or a compound represented by the following general formula (2).

（一般式（２）中、Ｒ^１４は炭素数１〜１０のアルキル基を示し、炭素数１〜５のアルキル基であってもよい。）

(In the general formula (2), R ¹⁴ represents an alkyl group having 1 to 10 carbon atoms, and may be an alkyl group having 1 to 5 carbon atoms.)

Examples of such a diol compound include diol compounds such as dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolnonanoic acid.
These diol compounds may be used alone or in combination of two or more.

  Next, the example of the process of manufacturing a carboxy-group containing urethane / epoxy (meth) acrylate resin using the raw material component mentioned above is demonstrated.

[Method for producing carboxy group-containing urethane / epoxy (meth) acrylate resin]
In the production of the carboxy group-containing urethane / epoxy (meth) acrylate resin, first, the raw material epoxy (meth) acrylate, the raw material diisocyanate, and the raw material diol are reacted.
In this reaction, a so-called urethanization reaction occurs between the hydroxyl group of the raw material epoxy (meth) acrylate and the isocyanate group of the raw material diisocyanate, and between the hydroxyl group of the raw material diol and the isocyanate group of the raw material diisocyanate.
By this reaction, for example, a carboxy group-containing urethane / epoxy (meth) acrylate resin polymerized alternately or in a block form via a structural unit derived from a raw material epoxy (meth) acrylate and a structural unit derived from a raw material diol is produced. .

  In the production process of the carboxy group-containing urethane / epoxy (meth) acrylate resin, in addition to the raw material epoxy (meth) acrylate, raw material diisocyanate, and raw material diol, an epoxy (meth) acrylate compound and / or a diol compound different from these, and / or A diisocyanate compound may be further added. This makes it possible to change the main chain structure of the resulting carboxy group-containing urethane / epoxy (meth) acrylate resin, and adjust the characteristics such as the acid value described below to a desired range. it can. In the above-described steps, a catalyst or the like may be used as appropriate.

  The structural unit constituting the main chain of the carboxy group-containing urethane / epoxy (meth) acrylate resin obtained by such a production method is represented by the following general formula (3).

（一般式（３）中、Ａは原料エポキシ（メタ）アクリレート及び原料ジオールから選ばれる１種の化合物の２価の残基を示し、Ｂは原料ジイソシアネートの２価の残基を示す。ただし、カルボキシ基含有ウレタン／エポキシ（メタ）アクリレート樹脂に複数存在する一般式（３）で表される構造単位の中でも、少なくとも１つの構造単位は原料エポキシ（メタ）アクリレートに由来する２価の残基であるＡを有するものであり、少なくとも１つの構造単位は原料ジイソシアネートに由来する２価の残基であるＢを有するものである。）

(In General Formula (3), A represents a divalent residue of one compound selected from raw material epoxy (meth) acrylate and raw material diol, and B represents a divalent residue of raw material diisocyanate, provided that Among the structural units represented by the general formula (3) present in plural in the carboxyl group-containing urethane / epoxy (meth) acrylate resin, at least one structural unit is a divalent residue derived from the raw material epoxy (meth) acrylate. (It has a certain A, and at least one structural unit has a B which is a divalent residue derived from a raw material diisocyanate.)

  Such a carboxy group-containing urethane / epoxy (meth) acrylate resin may be a compound having structural units represented by the following general formulas (4-1) and (4-2), and these structural units: May be a compound polymerized alternately or in a block form.

（一般式（４−１）中、Ｒ^１１は前記分子内に２つ以上のエポキシ基を有する化合物の２価の残基を示し、Ｒ^１３は水素原子又はメチル基を示す。
一般式（４−１）及び（４−２）中、Ｒ^１２は原料ジイソシアネート化合物の２価の残基を示す。
一般式（４−２）中、Ｒ^１４は炭素数１〜１０のアルキル基を示し、炭素数１〜５のアルキル基であってもよい。また、式中に複数ある基は、それぞれ同一でも異なってもいてもよい。
カルボキシ基含有ウレタン／エポキシ（メタ）アクリレート樹脂が有する末端の水酸基は、飽和又は不飽和多塩基酸無水物で処理されていてもよい。）

(In the general formula (4-1), R ¹¹ represents a divalent residue of a compound having two or more epoxy groups in the molecule, and R ¹³ represents a hydrogen atom or a methyl group.
In General Formulas (4-1) and (4-2), R ¹² represents a divalent residue of the raw material diisocyanate compound.
In General Formula (4-2), R ¹⁴ represents an alkyl group having 1 to 10 carbon atoms, and may be an alkyl group having 1 to 5 carbon atoms. In addition, a plurality of groups in the formula may be the same or different.
The terminal hydroxyl group of the carboxy group-containing urethane / epoxy (meth) acrylate resin may be treated with a saturated or unsaturated polybasic acid anhydride. )

The total content of the structural unit represented by the general formula (4-1) and the structural unit represented by the general formula (4-2) in the carboxy group-containing urethane / epoxy (meth) acrylate resin is as follows. 50-100 mol% may be sufficient with respect to the total number of moles of the structural unit represented by the said General formula (3) contained in a carboxy-group containing urethane / epoxy (meth) acrylate resin, and 60-100 mol % May be sufficient, and 80-100 mol% may be sufficient.
The content of the structural unit represented by the general formula (4-1) in the carboxy group-containing urethane / epoxy (meth) acrylate resin is the above-described general content contained in the carboxy group-containing urethane / epoxy (meth) acrylate resin. The total number of moles of the structural unit represented by the formula (3) may be 5 to 95 mol%, 10 to 90 mol%, or 15 to 80 mol%. .
In the carboxy group-containing urethane / epoxy (meth) acrylate resin, the content of the structural unit represented by the general formula (4-2) is based on the total number of moles of the structural unit represented by the general formula (3). The amount may be 5 to 95 mol%, 10 to 90 mol%, or 15 to 80 mol%.

  That is, the carboxy group-containing urethane / epoxy (meth) acrylate resin may be a compound having a structural unit represented by the following general formula (5).

（一般式（５）中、Ｒ^１１〜Ｒ^１４は前記と同様である。）

(In the general formula (5), R ^{11 to} R ¹⁴ are the same as described above.)

As the carboxy group-containing urethane / epoxy (meth) acrylate resin, among the compounds represented by the general formula (5), from the viewpoint of transparency and heat resistance, a raw material epoxy (meth) acrylate compound that becomes one of the main skeletons The hard segment portion, that is, R ¹¹ may be of a bisphenol type skeleton, and may be of a bisphenol A type skeleton.
As such a carboxy group-containing urethane / epoxy (meth) acrylate resin, a commercially available product may be used. As a commercially available carboxy group-containing urethane / epoxy (meth) acrylate resin, “UXE-3000”, “UXE-3011”, “UXE-3012”, “UXE-3024” (all manufactured by Nippon Kayaku Co., Ltd.) Etc. are commercially available. These carboxy group-containing urethane / epoxy (meth) acrylate resins may be used alone or in combination of two or more.

The acid value of the carboxy group-containing urethane / epoxy (meth) acrylate resin may be 20 to 200 mgKOH / g, 30 to 180 mgKOH / g, or 40 to 150 mgKOH / g. Thereby, the developability by the alkaline aqueous solution of the photosensitive resin composition becomes good, and the excellent resolution tends to be obtained.
The acid value of the carboxy group-containing urethane / epoxy (meth) acrylate resin can be adjusted by the raw material composition. For example, the acid value can be increased by increasing the blending amount of the raw material diol compound, and conversely, the acid value can be lowered by decreasing the blending amount of the raw material diol compound.

The acid value of the carboxy group-containing urethane / epoxy (meth) acrylate resin can be measured by the following method. First, about 1 g of a resin solution to be measured is precisely weighed, then about 30 g of acetone is added to the resin solution, and the resin solution is uniformly dissolved. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N potassium hydroxide (KOH) aqueous solution. And an acid value is computed by following Formula.
A = 10 × V _f × 56.11 / (W _p × I)
Incidentally, the acid value A in the formula (mg KOH / g), a _{V f} is titer of KOH aqueous solution of 0.1 N (mL), the mass of the resin solution is _{W p} measures the (g), I is measured The ratio (mass%) of the non-volatile content of the resin solution to be performed is shown.

The weight average molecular weight (Mw) of the carboxy group-containing urethane / epoxy (meth) acrylate resin may be 2,000 to 50,000, or 3,000 to 30,000 from the viewpoint of coating properties. It may be 5,000 to 20,000.
In addition, a weight average molecular weight (Mw) can be calculated | required from the standard polystyrene conversion value by a gel permeation chromatography (GPC), and can be specifically calculated | required from the method as described in an Example.

  The content of the compound (A) having an acidic group in the photosensitive resin composition used in the present invention may be 10 to 90% by mass with respect to the total amount of the component (A) and the component (B). If the content of the component (A) is 10% by mass or more, the developability of the uncured portion by exposure becomes sufficient, and if the content of the component (A) is 90% by mass or less, the component (B) at the time of exposure. Is entangled by the resin and hardens easily, and the developer resistance tends to be sufficient. From the above viewpoint, the content of the component (A) may be 20 to 80% by mass or 30 to 70% by mass.

<(B) Compound having polymerizable group (component (B))>
Hereinafter, the component (B) used in the present invention will be described.
(B) As a compound having a polymerizable group, any compound having a functional group that undergoes a polymerization reaction upon irradiation with actinic rays can be used without particular limitation. Among these, from the viewpoint of the strength of the cured product, it is preferable to use a compound having two or more polymerizable groups in one molecule. Examples of the polymerizable group include an ethylenically unsaturated group, an epoxy group, an oxetanyl group, and an isocyanato group. Among these, it is preferable to use an ethylenically unsaturated group and an epoxy group from the viewpoint of reactivity and transparency.

  Examples of the compound having two or more ethylenically unsaturated groups in the molecule include a bifunctional (meth) acrylate compound and a polyfunctional (meth) acrylate compound having three or more functions.

Examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. , Propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethoxylated polypropylene glycol di ( (Meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl Cold di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di ( (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, glycerin di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, ethoxylated 2-methyl Aliphatic (meth) acrylates such as 1,3-propanediol di (meth) acrylate; cyclohexanedimethanol (meth) acrylate, ethoxylated cyclohexanedimethanol (meth) acrylate, propoxylated cyclohexanedimethanol (meth) acrylate, ethoxy Conversion Lopoxylated cyclohexanedimethanol (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, ethoxylated tricyclodecane dimethanol (meth) acrylate, propoxylated tricyclodecane dimethanol (meth) acrylate, ethoxylated propoxylated tricyclo Decandimethanol (meth) acrylate, ethoxylated hydrogenated bisphenol A di (meth) acrylate, propoxylated hydrogenated bisphenol A di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol A di (meth) acrylate, ethoxylated hydrogenated Bisphenol F di (meth) acrylate, propoxylated hydrogenated bisphenol F di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol F di (meth) acrylate, ethoxylated water Bisphenol AF di (meth) acrylate, propoxylated hydrogenated bisphenol AF di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol AF di (meth) acrylate, ethoxylated hydrogenated bisphenol S di (meth) acrylate, propoxylated water Bisphenol S di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol S di (meth) acrylate, 1,2-decahydronaphthalene dimethacrylate, 1,3-decahydronaphthalene dimethacrylate, 1,4- Decahydronaphthalene (meth) acrylate, 1,5-decahydronaphthalene (meth) acrylate, 1,6-decahydronaphthalene (meth) acrylate, 1,7-decahydronaphthalene (meth) acrylate, 1, 8-Dekahi Cycloaliphatic such as lonaphthalene di (meth) acrylate, 2,3-decahydronaphthalene (meth) acrylate, 2,6-decahydronaphthalene (meth) acrylate, 2,7-decahydronaphthalene (meth) acrylate (Meth) acrylate; ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, ethoxylated propoxylated bisphenol A di (meth) acrylate, ethoxylated bisphenol F di (meth) acrylate, propoxylated bisphenol F di (meth) acrylate, ethoxylated propoxylated bisphenol F di (meth) acrylate, ethoxylated bisphenol AF di (meth) acrylate, propoxylated bisphenol AF di (meth) acrylate, etoxy Propoxylated bisphenol AF di (meth) acrylate, ethoxylated bisphenol S di (meth) acrylate, propoxylated bisphenol S di (meth) acrylate, ethoxylated propoxylated bisphenol S di (meth) acrylate, ethoxylated fluorene type di (meth) ) Aromatic (meth) acrylates such as acrylate, propoxylated fluorene type di (meth) acrylate, ethoxylated propoxylated fluorene type di (meth) acrylate; ethoxylated isocyanuric acid di (meth) acrylate, propoxylated isocyanuric acid di (meth) ) Heterocyclic (meth) acrylates such as acrylates, ethoxylated propoxylated isocyanuric acid di (meth) acrylates; modified caprolactones thereof; neopentyl glycol type epoxy di (meth) a Aliphatic epoxy (meth) acrylates such as acrylate; cyclohexanedimethanol type epoxy (meth) acrylate, hydrogenated bisphenol A type epoxy di (meth) acrylate, hydrogenated bisphenol F type epoxy di (meth) acrylate, hydrogenated bisphenol AF type epoxy di ( Aliphatic epoxy (meth) acrylates such as (meth) acrylate, hydrogenated bisphenol S type epoxy di (meth) acrylate, decahydronaphthalene type epoxy di (meth) acrylate; resorcinol type epoxy di (meth) acrylate, bisphenol A type epoxy di (meth) Acrylate, bisphenol F type epoxy di (meth) acrylate, bisphenol AF type epoxy di (meth) acrylate, bisphenol S type epoxy di (meth) acrylate , Fluorene type epoxy di (meth) acrylate, biphenyl-type epoxy di (meth) acrylate, and aromatic epoxy (meth) acrylates such as naphthalene type epoxy di (meth) acrylate.
Among these, from the viewpoint of transparency and heat resistance, the alicyclic (meth) acrylate; the aromatic (meth) acrylate; the heterocyclic (meth) acrylate; the alicyclic epoxy (meth) acrylate; It is preferably a group epoxy (meth) acrylate.

Examples of the trifunctional or higher polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and ethoxylated propoxylated tri Methylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated propoxylated pentaerythritol tri (meth) acrylate, pentaerythritol Tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) Aliphatic polyfunctional (meth) acrylates such as acrylate, ethoxylated propoxylated pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; ethoxylated isocyanuric acid tri (meth) Heterocyclic polyfunctional (meth) acrylates such as acrylate, propoxylated isocyanuric acid tri (meth) acrylate, ethoxylated propoxylated isocyanuric acid tri (meth) acrylate; caprolactone-modified products of these polyfunctional (meth) acrylates; ) Phenol novolac type epoxy (meth) acrylate, cresol novolac type epoxy (meth) acrylate, bisphenol A novolac type epoxy (having three or more acryloyl groups) ) Acrylate, bisphenol F novolac epoxy (meth) acrylate, bisphenol AF novolac epoxy (meth) acrylate, bisphenol S novolac epoxy (meth) acrylate, biphenylaralkyl epoxy (meth) acrylate, bisnaphthalene epoxy (meth) Aromatic polyfunctional epoxy (meth) acrylates such as acrylate can be used.
Among these, from the viewpoints of transparency, processability, size controllability, and heat resistance, heterocyclic polyfunctional (meth) acrylates and aromatic polyfunctional epoxy (meth) acrylates may be used.

  These bifunctional or trifunctional or higher polyfunctional (meth) acrylates may be used alone or in combination of two or more, and may be used in combination with other polymerizable compounds.

  Moreover, an epoxy group is mentioned as a preferable functional group other than the said ethylenically unsaturated group. By using a compound containing an epoxy group, a so-called epoxy-carboxylate reaction occurs with the carboxylic acid of the compound having the acidic group (A), and it is expected to increase the heat resistance and the strength of the cured product. The

  The compound containing an epoxy group is preferably a compound having two or more epoxy groups in the molecule, and is a bisphenol A type epoxy resin, a tetrabromobisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol AF type. Bifunctional phenol glycidyl ether such as epoxy resin, bisphenol AD type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin; hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated 2 , 2'-biphenol type epoxy resin, hydrogenated bifunctional phenol glycidyl ether such as hydrogenated 4,4'-biphenol type epoxy resin; phenol novolac type epoxy resin, cresol novolac type epoxy resin, dishi Polyfunctional phenol glycidyl ethers such as clopentadiene-phenol type epoxy resin and tetraphenylolethane type epoxy resin; polyethylene glycol type epoxy resin, polypropylene glycol type epoxy resin, neopentyl glycol type epoxy resin, 1,6-hexanediol type epoxy Bifunctional aliphatic alcohol glycidyl ether such as resin; Bifunctional alicyclic alcohol glycidyl ether such as cyclohexanedimethanol type epoxy resin and tricyclodecane dimethanol type epoxy resin; Trimethylolpropane type epoxy resin, sorbitol type epoxy resin, glycerin Functional aliphatic alcohol glycidyl ether such as epoxy resin; bifunctional aromatic glycidyl ester such as diglycidyl phthalate; Bifunctional alicyclic glycidyl esters such as diglycidyl oxalate and diglycidyl hexahydrophthalate; bifunctional aromatic glycidyl amines such as N, N-diglycidyl aniline and N, N-diglycidyl trifluoromethyl aniline; N, N, N ′, N′-tetraglycidyl-4,4-diaminodiphenylmethane, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, N, O-triglycidyl-p-aminophenol, etc. Polyfunctional aromatic glycidyl amines of the following: bifunctional alicyclic epoxy resins such as alicyclic diepoxy acetals, alicyclic diepoxy adipates, alicyclic diepoxy carboxylates, vinylcyclohexene dioxide; 2,2-bis ( 1,2- of hydroxymethyl) -1-butanol Polyfunctional alicyclic epoxy resins such as adducts with poxy-4- (2-oxiranyl) cyclohexane; polyfunctional heterocyclic epoxy resins such as triglycidyl isocyanurate; bifunctional or polyfunctional silicon such as organopolysiloxane type epoxy resins Containing epoxy resin.

Among these, from the viewpoint of transparency and heat resistance, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, bisphenol AD type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type Bifunctional phenol glycidyl ether such as epoxy resin; hydrogenated bifunctional phenol glycidyl ether; polyfunctional phenol glycidyl ether; bifunctional alicyclic alcohol glycidyl ether; bifunctional aromatic glycidyl ester; bifunctional alicyclic Preferably, the glycidyl ester; the bifunctional alicyclic epoxy resin; the polyfunctional alicyclic epoxy resin; the polyfunctional heterocyclic epoxy resin; and the bifunctional or polyfunctional silicon-containing epoxy resin.
These compounds can be used alone or in combination of two or more, and can also be used in combination with other polymerizable compounds.

  Moreover, the compound which has both the said ethylenically unsaturated group and epoxy group in a molecule | numerator can be used.

  The compound having both the ethylenically unsaturated group and the epoxy group is an epoxy obtained by reacting an epoxy resin having two or more epoxy groups in one molecule with less than one equivalent of a (meth) acrylic acid compound. Examples thereof include epoxy (meth) acrylate having a group, hydroxyalkyl (meth) acrylate glycidyl ether obtained by reacting hydroxyalkyl (meth) acrylate and epihalohydrin.

  As the epoxy resin containing two or more epoxy groups in one molecule, the above bifunctional or trifunctional or higher polyfunctional epoxy compound can be used. Especially, the epoxy compound used from a viewpoint of transparency may be a bisphenol type epoxy compound.

Specific examples of the hydroxyalkyl (meth) acrylate glycidyl ether obtained by reacting the hydroxyalkyl (meth) acrylate with epihalohydrin include 2-hydroxyethyl (meth) acrylate glycidyl ether, 2-hydroxypropyl (meth) acrylate glycidyl. Ether, 3-hydroxypropyl (meth) acrylate glycidyl ether, 2-hydroxybutyl (meth) acrylate glycidyl ether, 3-hydroxybutyl (meth) acrylate glycidyl ether, 4-hydroxybutyl (meth) acrylate glycidyl ether, 2-hydroxypentyl (Meth) acrylate glycidyl ether, 3-hydroxypentyl (meth) acrylate glycidyl ether, 4-hydroxypentyl (Meth) acrylate glycidyl ether, 5-hydroxypentyl (meth) acrylate glycidyl ether, 2-hydroxyhexyl (meth) acrylate glycidyl ether, 3-hydroxyhexyl (meth) acrylate glycidyl ether, 4-hydroxyhexyl (meth) acrylate glycidyl ether, Examples include 5-hydroxyhexyl (meth) acrylate glycidyl ether, 6-hydroxyhexyl (meth) acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylate.
These epoxy (meth) acrylates having an epoxy group may be used alone or in combination of two or more, and may be further used in combination with other polymerizable compounds.

  Moreover, the compound which has both an ethylenically unsaturated group and an epoxy group in a molecule | numerator is an arylene group, an aryleneoxy group, an alkylene arylene group, an alicyclic hydrocarbon in a molecule | numerator from a heat resistant and transparent viewpoint. The compound which has 1 or more types chosen from group and an alkylene group may be sufficient. The arylene group represents a divalent aromatic hydrocarbon group such as a phenylene group, a naphthylene group, a biphenylene group, or a fluorenylene group, and a divalent aromatic heterocyclic group such as a carbazolylene group or a pyridylene group.

  More specifically, it is at least one selected from a compound represented by the following general formula (6) having an ethylenically unsaturated group, an epoxy group, and an arylene group, and a compound represented by the following general formula (7). Also good.

（一般式（６）中、Ｘ^２１及びＸ^２２は各々独立に−Ｏ−、−Ｓ−、−Ｏ（ＣＨ_２ＣＨ_２Ｏ）_ａ−及び−Ｏ［ＣＨ_２ＣＨ（ＣＨ_３）Ｏ］_ｂ−のいずれかの２価の基を示し、ａ及びｂは各々独立して１〜３０の整数を示す。
一般式（６）中、Ｙ^２は、

のいずれかで示される２価の基を示し、ｃは２〜１０の整数を示す。
一般式（６）中、Ｒ^２１は水素原子及びメチル基のいずれかを示す。Ｒ^２２〜Ｒ^２５は各々独立して、水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜２０の有機基及び炭素数１〜２０の含フッ素有機基のいずれかを示す。）

(In General Formula (6), X ²¹ and X ²² are each independently —O—, —S—, —O (CH ₂ CH ₂ O) _a — and —O [CH ₂ CH (CH ₃ ) O] _b. -Represents any divalent group, and a and b each independently represent an integer of 1 to 30.
In general formula (6), Y ² is

And a c represents an integer of 2 to 10.
In general formula (6), R ²¹ represents either a hydrogen atom or a methyl group. R ^{22 to} R ²⁵ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an organic group having 1 to 20 carbon atoms, or a fluorine-containing organic group having 1 to 20 carbon atoms. . )

で表される基は、ｃ＋１個の炭素数を有する２価のシクロアルキレン基を意味する。 In the present specification,-in a divalent group means a bond,

Is a divalent cycloalkylene group having c + 1 carbon atoms.

（一般式（７）中、Ｘ^３１及びＸ^３２は各々独立に−Ｏ−、−Ｓ−、−Ｏ（ＣＨ_２ＣＨ_２Ｏ）_ａ−及び−Ｏ［ＣＨ_２ＣＨ（ＣＨ_３）Ｏ］_ｂ−のいずれかの２価の基を示し、ａ及びｂは各々独立して１〜３０の整数を示し、ｄは１〜１０の整数を示す。
一般式（７）中、Ｙ^３は、

のいずれかで示される２価の基を示し、ｃは２〜１０の整数を示す。
一般式（７）中、Ｒ^３１は水素原子及びメチル基のいずれかを示す。Ｒ^３２〜Ｒ^３５は各々独立して、水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜２０の有機基及び炭素数１〜２０の含フッ素有機基のいずれかを示す。）

(In the general formula (7), X ³¹ and X ³² are each independently —O—, —S—, —O (CH ₂ CH ₂ O) _a — and —O [CH ₂ CH (CH ₃ ) O] _b. -Represents any divalent group, a and b each independently represent an integer of 1 to 30, and d represents an integer of 1 to 10.
In general formula (7), Y ³ is

And a c represents an integer of 2 to 10.
In General Formula (7), R ³¹ represents either a hydrogen atom or a methyl group. R ^{32 to} R ³⁵ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an organic group having 1 to 20 carbon atoms, or a fluorine-containing organic group having 1 to 20 carbon atoms. . )

  Examples of the organic group in the general formulas (6) and (7) include monovalent groups such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a carbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a carbamoyl group. They may be further substituted with a hydroxy group, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a carbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, and the like.

  The content of the compound (B) having a polymerizable group may be 10 to 90% by mass with respect to the total amount of the component (A) and the component (B). When the content of the component (B) is 10% by mass or more, it becomes easy to cure together with the component (A), and the lack of developer resistance tends to be suppressed. When the content of the component (B) is 90% by mass or less, the strength and flexibility of the cured product tend to be sufficient. From these viewpoints, the content of the component (B) may be 20 to 80% by mass or 30 to 70% by mass.

<(C) Photopolymerization initiator (component (C) >>
Hereinafter, the (C) photopolymerization initiator used in the present invention will be described.
As the (C) photopolymerization initiator, any photopolymerization initiator can be used without particular limitation as long as it can initiate polymerization of the polymerizable compound (B) by irradiation with actinic rays.

  (C) As a specific example of a photoinitiator, when using the compound which has an ethylenically unsaturated group for (B) component, since it can harden | cure at normal temperature, a photoradical polymerization initiator is mentioned suitably.

Examples of the photo radical polymerization initiator include benzoinketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane- Α-hydroxy ketones such as 1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one; 2-benzyl-2-dimethylamino-1 Α-amino ketones such as-(4-morpholinophenyl) -butan-1-one, 1,2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one; Oxime esters such as (4-phenylthio) phenyl] -1,2-octadion-2- (benzoyl) oxime; bis (2,4,6-trimethyl) Phosphine oxides such as benzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2- (o-chlorophenyl) ) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer 2,4,5-triaryl such as 2-mer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Imidazole dimer; benzophenone, N, N′-tetramethyl-4,4′-diaminobe Benzophenone compounds such as Nzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthra Quinone compounds such as quinone, 2-methyl-1,4-naphthoquinone and 2,3-dimethylanthraquinone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; Benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl compounds such as benzyldimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis (9,9′-acridinylheptane); N-phenylglycine A coumarin or the like.
Among these, one or more selected from α-hydroxy ketone and phosphine oxide may be used from the viewpoints of curability, transparency, processability, size controllability, and heat resistance.

  In the 2,4,5-triarylimidazole dimer, the substituents of the aryl groups at the two triarylimidazole sites may give the same and symmetric compounds, but give differently asymmetric compounds. May be. Moreover, you may combine a thioxanthone compound and a tertiary amine like the combination of diethylthioxanthone and dimethylaminobenzoic acid.

  In addition to the photoradical initiator, a thermal radical initiator that generates radical species by heating to initiate polymerization may be used.

Examples of the thermal radical polymerization initiator include ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide; 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butyl) Peroxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis Peroxyketals such as (t-hexylperoxy) -3,3,5-trimethylcyclohexane; hydroperoxides such as p-menthane hydroperoxide; α, α′-bis (t-butylperoxy) diisopropylbenzene; Dicumyl peroxide, t-butyl cumyl peroxide, Dialkyl peroxides such as t-butyl peroxide; diacyl peroxides such as octanoyl peroxide, lauroyl peroxide, stearyl peroxide, benzoyl peroxide; bis (4-t-butylcyclohexyl) peroxydicarbonate, di- Peroxycarbonates such as 2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-3-methoxybutyl peroxycarbonate; t-butyl peroxypivalate, t-hexyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2 -Ethylhexanoe T-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t -Butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, 2,5-dimethyl-2, Peroxyesters such as 5-bis (benzoylperoxy) hexane and t-butylperoxyacetate; 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2'-dimethyl Reronitoriru) azo compounds, and the like.
Among these, one or more selected from diacyl peroxides, peroxyesters, and azo compounds may be used from the viewpoints of curability, transparency, processability, size controllability, and heat resistance.

  These radical polymerization initiators may be used alone or in combination of two or more kinds, or may be used in combination with an appropriate sensitizer.

  Moreover, when using the compound containing an epoxy group as (B) component, you may use the photocationic polymerization initiator in which normal temperature hardening is possible as (C) polymerization initiator.

Examples of the photocationic polymerization initiator include aryl diazonium salts such as p-methoxybenzenediazonium hexafluorophosphate, diaryliodonium salts such as diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate; triphenylsulfonium hexafluorophosphate, triphenyl Triarylsulfonium salts such as sulfonium hexafluoroantimonate, diphenyl-4-thiophenoxyphenylsulfonium hexafluorophosphate, diphenyl-4-thiophenoxyphenylsulfonium hexafluoroantimonate, diphenyl-4-thiophenoxyphenylsulfonium pentafluorohydroxyantimonate ; Triphenylselenonium hexaf Triarylselenonium salts such as orophosphate, triphenylselenonium tetrafluoroborate and triphenylselenonium hexafluoroantimonate; dialkylphenacylsulfonium such as dimethylphenacylsulfonium hexafluoroantimonate and diethylphenacylsulfonium hexafluoroantimonate Salts; dialkyl-4-hydroxy salts such as 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate and 4-hydroxyphenylbenzylmethylsulfonium hexafluoroantimonate; α-hydroxymethylbenzoin sulfonate, N-hydroxyimide sulfonate, α- Examples thereof include sulfonic acid esters such as sulfonyloxy ketone and β-sulfonyloxy ketone.
Among these, the triarylsulfonium salt may be used from the viewpoints of curability, transparency, processability, size controllability, and heat resistance.

  Furthermore, a thermal cationic polymerization initiator that generates cationic species by heating and starts curing may be used.

Examples of the thermal cationic polymerization initiator include benzylsulfonium salts such as p-alkoxyphenylbenzylmethylsulfonium hexafluoroantimonate; benzyl-p-cyanopyridinium hexafluoroantimonate, 1-naphthylmethyl-o-cyanopyridinium hexafluoroantimonate And pyridinium salts such as cinnamyl-o-cyanopyridinium hexafluoroantimonate; and benzylammonium salts such as benzyldimethylphenylammonium hexafluoroantimonate.
Among these, from the viewpoints of curability, transparency, processability, size controllability, and heat resistance, the benzylsulfonium salt may be used.

  These cationic polymerization initiators may be used alone or in combination of two or more kinds, and may be used in combination with an appropriate sensitizer.

  (C) Content of a polymerization initiator may be 0.1-10 mass% with respect to 100 mass% of total amounts of (A) component and (B) component. When the content of (C) the polymerization initiator is 0.1% by mass or more, curing tends to be sufficient, and when it is 10% by mass or less, sufficient light transmittance tends to be obtained. From such a viewpoint, the content of the (C) polymerization initiator may be 0.3 to 7% by mass or 0.5 to 5% by mass.

<(D) Chain transfer agent (component (D)>
Hereinafter, the (D) chain transfer agent used in the present invention will be described.
In the present invention, the (D) chain transfer agent can be used without particular limitation as long as it functions as a chain transfer agent in a radical polymerization reaction. Specifically, a compound having an ethylenically unsaturated group such as a styrene dimer derivative, a compound containing a nitrogen atom such as a pyrazole derivative, and a compound containing a sulfur atom such as an alkylthiol derivative are preferably exemplified. Of these, alkylthiol derivatives may be used from the viewpoints of reactivity and solubility, and more preferably compounds containing two or more thiol groups in one molecule may be used.

  The compound containing two or more thiol groups in one molecule may be, for example, one selected from compounds represented by the following general formula (8).

（一般式（８）中、Ｒ^４１はメチレン基、炭素数２〜１０のアルキレン基である。但し、これらの基は水素原子の一部または全部がアルキル基で置換されていてもよい。Ｙ^４は、単結合、−ＣＯ−または−Ｏ−ＣＯ−である。ｎは２〜１０の整数である。Ａ^１は、１個または複数個のエーテル結合を有していてもよい炭素数２〜７０のｎ価の炭化水素基、または、ｎが３の場合下記一般式（９）で示される基である。）

(In the general formula (8), R ⁴¹ is a methylene group or an alkylene group having 2 to 10 carbon atoms. However, in these groups, some or all of the hydrogen atoms may be substituted with alkyl groups. Y ⁴ represents a single bond, —CO— or —O—CO—, n represents an integer of 2 to 10. A ¹ represents 2 carbon atoms which may have one or more ether bonds. An n-valent hydrocarbon group of ˜70, or a group represented by the following general formula (9) when n is 3.

（上記式（９）中、Ｒ^５１〜Ｒ^５３は、それぞれ独立してメチレン基又は炭素数２〜１０の炭化水素基である。）

(In the above formula ^(9), R 51 ^{to R 53} is a hydrocarbon group each independently a methylene group or a C2-10 carbon.)

  As the compound represented by the above formula (8), an esterified product of mercaptocarboxylic acid and a polyhydric alcohol can be used. Examples of the mercaptocarboxylic acid constituting the esterified product include thioglycolic acid, 3-mercaptopropionic acid, 3-mercaptobutanoic acid, and 3-mercaptopentanoic acid. Examples of the polyhydric alcohol constituting the esterified product include ethylene glycol, propylene glycol, trimethylolpropane, pentaerythritol, tetraethylene glycol, dipentaerythritol, 1,4-butanediol, pentaerythritol and the like.

  Specifically, trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), dipentaerythritol hexakis (3- Mercaptopropionate), pentaerythritol tetrakis (thioglycolate), 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopentylate) ), 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione and the like.

  These chain transfer agents can be used alone or in combination of two or more.

  (D) As content of a chain transfer agent, 0.1-20 mass% may be sufficient with respect to 100 mass% of total amounts of (A) component and (B) component. If it is 0.1% by mass or more, polymerization by the compound having a polymerizable group (B) tends to be promoted and the strength of the cured product tends to be high, and if it is 20% by mass or less, pattern size control is easy. It tends to be possible. From such a viewpoint, the content of the (D) chain transfer agent may be 0.3 to 15% by mass or 0.5 to 10% by mass.

  Moreover, in the photosensitive resin composition used for this invention, an antioxidant, a yellowing inhibitor, a ultraviolet absorber, visible light absorption other than said (A)-(D) component as needed. You may add additives, such as an agent, a coloring agent, a plasticizer, a stabilizer, a filler, in the range which does not inhibit the effect of this invention.

  The photosensitive resin composition used in the present invention is produced by mixing (A) a compound having an acidic group, (B) a compound having a polymerizable group, (C) a polymerization initiator, and (D) a chain transfer agent. it can. Mixing may be performed in an organic solvent in which the components (A) to (D) are dissolved, or the components (A) to (D) may be mixed using a known mixer without using an organic solvent. Good.

The photosensitive resin composition used in the present invention may be further diluted with an organic solvent and used as a photosensitive resin varnish.
In the present specification, the “photosensitive resin varnish” means a photosensitive resin composition used in the present invention containing 5% by mass or more of an organic solvent, and is also simply referred to as “varnish” in the present specification.

<Photosensitive resin varnish>
The organic solvent used for the production of the photosensitive resin varnish is not particularly limited as long as it can dissolve the components (A) to (D) constituting the photosensitive resin composition used in the present invention. Toluene, xylene , Aromatic hydrocarbons such as mesitylene, cumene, p-cymene and benzene; cyclic ethers such as tetrahydrofuran, tetrahydropyran and 1,4-dioxane; methanol, ethanol, 1-propanol, isopropanol, butanol, ethylene glycol, propylene glycol and the like Alcohols such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 3-pentanone, cyclopentanone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, etc .; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methyl lactate , Lactate ethi Esters such as γ-butyrolactone; Carbonates such as ethylene carbonate and propylene carbonate; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol Polyhydric alcohol alkyl ethers such as monoethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether Polyhydric alcohol alkyl ethers such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate Acetates; amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and the like.

Among these, from the viewpoint of solubility and boiling point, toluene, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, 3-pentanone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methyl lactate, lactic acid It may be ethyl, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate or N, N-dimethylacetamide. .
These organic solvents may be used alone or in combination of two or more.
Moreover, 10-80 mass% may be sufficient as solid content concentration in the photosensitive resin varnish.

When preparing the photosensitive resin varnish, the mixing method is not particularly limited, but may be mixed by stirring. Although there is no restriction | limiting in particular as a stirring method, From a viewpoint of stirring efficiency, stirring using a propeller may be sufficient and the rotation speed of a propeller may be 10-1,000 rotation / min (rpm). . If the rotation speed of the propeller is 10 revolutions / minute or more, the components (A) to (D) and the organic solvent components tend to be sufficiently mixed. If the revolution speed is 1,000 revolutions / minute or less, the propeller It tends to be able to suppress entrainment of bubbles due to rotation.
The stirring time is not particularly limited, but may be 1 to 24 hours. When the stirring time is 1 hour or more, the components (A) to (D) tend to be sufficiently mixed. When the stirring time is 24 hours or less, the varnish preparation time tends to be shortened.

The prepared varnish may be filtered using a filter.
The pore size of the filter may be 100 μm or less, 50 μm or less, or 30 μm or less. When the filter pore size is 100 μm or less, large foreign matters are removed, so that the occurrence of so-called “repelling” at the time of varnish application tends to be suppressed, and the scattering of light propagating through the core portion tends to be suppressed. is there.

  The prepared varnish may be used after defoaming. There is no restriction | limiting in particular in the defoaming method, The well-known decompression defoaming method using a vacuum pump and a bell jar, a defoaming apparatus with a vacuum apparatus, etc. can be applied.

  Although there is no restriction | limiting in particular in the pressure at the time of pressure reduction, It is preferable that it is a pressure which the organic solvent contained in a varnish does not boil. The vacuum degassing time is not particularly limited, but may be 1 to 60 minutes. When the vacuum degassing time is 1 minute or longer, the bubbles dissolved in the varnish tend to be sufficiently removed, and when it is 60 minutes or shorter, the organic solvent contained in the varnish is prevented from volatilizing excessively. It tends to be possible.

  You may use the photosensitive resin composition used by this invention as a photosensitive resin film manufactured by apply | coating to a base film and removing a solvent as needed.

There is no restriction | limiting in particular as said base film, Polyesters, such as polyethylene terephthalate (henceforth "PET"), polybutylene terephthalate, polyethylene naphthalate; Polyolefins, such as polyethylene and polypropylene; Polycarbonate, polyamide, polyimide, polyamideimide , Polyetherimide, polyether sulfide, polyether sulfone, polyether ketone, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, liquid crystal polymer and the like.
Among these, from the viewpoints of flexibility and toughness, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polycarbonate, polyamide, polyimide, polyamideimide, polyphenylene ether, polyphenylene sulfide, polyarylate, or polysulfone may be used. .

The thickness of the base film may be appropriately selected according to the intended flexibility, but may be 3 to 250 μm, 5 to 200 μm, or 10 to 150 μm. When the thickness of the substrate film is 3 μm or more, the film strength tends to be sufficient, and when it is 250 μm or less, sufficient flexibility tends to be obtained.
In addition, from the viewpoint of improving the peelability from the resin layer, a film that has been subjected to a release treatment with a release agent such as a silicone-based compound or a fluorine-containing compound may be used as necessary.

  The photosensitive resin film used in the present invention may have a structure having a base film, a photosensitive resin layer, and a protective film in this order, and includes a base film, a photosensitive resin layer, and a protective film, and has these in this order. A three-layer structure may be used.

The protective film is not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene. Among these, from the viewpoint of flexibility and toughness, polyesters such as polyethylene terephthalate; polyolefins such as polyethylene and polypropylene may be used.
In addition, from the viewpoint of improving the peelability from the photosensitive resin layer, a film that has been subjected to a release treatment with a release agent such as a silicone compound or a fluorine-containing compound may be used as the protective film, if necessary.
The thickness of the protective film may be appropriately selected according to the intended flexibility, but may be 10 to 250 μm, 15 to 200 μm, or 20 to 150 μm. When the thickness of the protective film is 10 μm or more, the film strength tends to be sufficient, and when it is 250 μm or less, sufficient flexibility tends to be obtained.

  Although the thickness of the photosensitive resin film used for this invention is not specifically limited, 1-500 micrometers may be sufficient after drying, 3-200 micrometers may be sufficient, and 5-150 micrometers may be sufficient. . If the thickness of the resin layer is 1 μm or more, the strength of the photosensitive resin film or a cured product of the film tends to be sufficient, and if it is 500 μm or less, the drying can be sufficiently performed. The amount of residual solvent can be kept low, and foaming when the cured product of the film is heated tends to be suppressed.

  The photosensitive resin film thus obtained can be easily stored, for example, by winding it into a roll. Moreover, a roll-shaped film can be cut out to a suitable size and stored as a sheet.

  The photosensitive resin composition used in the present invention is suitable as a photosensitive resin composition for forming an optical waveguide. Similarly, a photosensitive resin film comprising the photosensitive resin composition is a photosensitive resin film for forming an optical waveguide. It is suitable as.

When the photosensitive resin film is used as a photosensitive resin film for forming an optical waveguide, the substrate film is not particularly limited as long as it can transmit an actinic ray for exposure used for forming a core pattern described later. Polyethylene terephthalate And polyesters such as polybutylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polycarbonates, polyphenylene ethers and polyarylates. Among these, polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyolefins such as polypropylene may be used from the viewpoints of the transmittance of active light for exposure, flexibility and toughness.
Furthermore, a highly transparent base film may be used from the viewpoint of improving the transmittance of exposure actinic rays and reducing the side wall roughness of the core pattern. As such a highly transparent base film, “Cosmo Shine A1517”, “Cosmo Shine A4100” manufactured by Toyobo Co., Ltd. are commercially available.
In addition, from the viewpoint of improving the peelability from the resin layer, a film that has been subjected to a release treatment with a release agent such as a silicone compound or a fluorine-containing compound may be used as necessary.

  The base film of the photosensitive resin film for forming an optical waveguide may have a thickness of 3 to 200 μm, 5 to 150 μm, or 10 to 100 μm. If the thickness of the substrate film of the photosensitive resin film for forming the core part is 3 μm or more, the strength as a support tends to be sufficient, and if it is 200 μm or less, it is used for forming a photomask and an optical waveguide during pattern formation. There is a tendency that the gap with the photosensitive resin composition layer does not increase and the pattern formability is improved.

  The photosensitive resin film for forming an optical waveguide may have a structure having a base film, a photosensitive resin layer for forming an optical waveguide (photosensitive resin composition), and a protective film in this order. It is good also as a 3 layer structure which consists of a conductive resin layer and a protective film and has these in this order.

  The thus obtained photosensitive resin film for forming an optical waveguide can be easily stored, for example, by winding it into a roll. Moreover, a roll-shaped film can be cut out into a suitable size and stored in a sheet shape.

As the cured product of the photosensitive resin layer obtained by laminating the above-described photosensitive resin composition or the photosensitive resin film made of the photosensitive resin composition, the degree of swelling with respect to an alkaline aqueous solution described later is 10% by mass or less. When the degree of swelling with respect to the alkaline aqueous solution is 10% by mass or less, the penetration of the developer into the photosensitive resin layer tends to be suppressed, which is preferable from the viewpoint of size controllability and reliability. From such a viewpoint, it may be 7% by mass or less, or 5% by mass or less.
The degree of swelling is the change in mass of the cured product by immersing a cured product obtained by curing a photosensitive resin composition or a photosensitive resin film comprising the photosensitive resin composition in an arbitrary alkaline aqueous solution. It means a ratio calculated from the amount, and can be used as an index of swelling property.

  The optical waveguide according to the present invention is composed of a lower clad layer, a core portion, and an upper clad layer, and (I) a step of laminating a photosensitive resin layer made of a photosensitive resin composition on the core portion, and (II) a desired pattern. And (III) an optical waveguide obtained by a step of developing using an alkaline developer.

FIG. 1A shows a cross-sectional view of an optical waveguide 1 obtained by the optical waveguide manufacturing method of the present invention. The optical waveguide 1 is formed on a base material 5 and is formed of a core part 2 formed of a high refractive index core part forming photosensitive resin composition and a low refractive index clad layer forming photosensitive resin composition. The lower clad layer 4 and the upper clad layer 3 are formed.
The photosensitive resin composition or photosensitive resin film used in the present invention is used for the core portion 2, but as a composition having a reduced refractive index, at least one of the lower cladding layer 4 or the upper cladding layer 3 of the optical waveguide 1. Can be used.

  By using the above-mentioned photosensitive resin composition and / or the photosensitive resin film comprising the photosensitive resin composition, the developer is excellent in resistance to developing solution, and the pattern formability during pattern formation (correspondence between fine lines or narrow lines) Thus, it is possible to form a small fine pattern between the line width and the line. In addition, it is possible to provide a process with excellent productivity in which a large-area optical waveguide can be manufactured at one time.

As the base material 5, a hard base material such as a silicon substrate, a glass substrate, and a glass epoxy resin substrate such as FR-4 can be used.
Moreover, the optical waveguide 1 is good also as a flexible optical waveguide using the said base film with a softness | flexibility and toughness as the base material 5. FIG.
When using the base film having flexibility and toughness as the base material 5, the base material 5 may function as a cover film for the optical waveguide 1. By disposing the cover film, the flexibility and toughness of the cover film can be imparted to the optical waveguide 1. Moreover, since the adhesion of the dirt to the optical waveguide 1 and the damage can be prevented, the handleability is improved.
From the above viewpoint, a base material (cover film) 5 is disposed outside the upper cladding layer 3 as shown in FIG. 1B, or the lower cladding layer 4 and the upper cladding as shown in FIG. Substrate (cover film) 5 may be disposed on both outer sides of layer 3.
Further, when the optical waveguide 1 has sufficient flexibility and toughness, the substrate (cover film) may not be disposed as shown in FIG.

The thickness of the lower cladding layer 4 is not particularly limited, but may be 2 to 200 μm, 5 to 100 μm, or 7 to 80 μm. When the thickness of the lower clad layer 4 is 2 μm or more, it tends to be easy to confine propagating light inside the core, and when it is 200 μm or less, it is possible to suppress an excessive increase in the thickness of the entire optical waveguide 1. There is a tendency. The thickness of the lower cladding layer 4 is a value from the boundary between the core portion 2 and the lower cladding layer 4 to the lower surface of the lower cladding layer 4.
Note that the thickness of the optical waveguide forming resin film used to form the lower cladding layer 4 may be adjusted as appropriate so that the thickness of the cured lower cladding layer 4 is in the above range.

The height of the core part 2 is not particularly limited, but may be 10 to 100 μm, 15 to 80 μm, or 20 to 70 μm. When the height of the core portion 2 is 10 μm or more, the alignment tolerance tends to be suppressed in the coupling with the light emitting / receiving element or the optical fiber after the formation of the optical waveguide, and when the height is 100 μm or less, the optical waveguide In the coupling with the light emitting / receiving element or the optical fiber after the formation, the coupling efficiency tends to be suppressed from being reduced.
In addition, what is necessary is just to adjust suitably the thickness of the photosensitive resin film used in order to form the core part 2 so that the height of the core part 2 after hardening may become said range.

The thickness of the upper clad layer 3 is not particularly limited as long as the core portion 2 can be embedded. However, the thickness after drying may be 12 to 500 μm or 15 to 200 μm. It may be 20 to 150 μm.
The thickness of the upper clad layer 3 may be the same as or different from the thickness of the lower clad layer 4 formed first, but is thicker than the thickness of the lower clad layer 4 from the viewpoint of embedding the core portion 2. May be.
The thickness of the upper cladding layer 3 is a value from the boundary between the core portion 2 and the lower cladding layer 4 to the upper surface of the upper cladding layer 3.

  The optical waveguide 1 according to the present invention may have an optical propagation loss at a wavelength of 850 nm of 0.20 dB / cm or less. When the optical propagation loss is 0.20 dB / cm or less, the optical loss tends to be small and the intensity of the transmission signal tends to be sufficient.

<Optical waveguide manufacturing method>
As a method of manufacturing the optical waveguide 1 according to the present invention, the core part (I) a step of laminating a photosensitive resin layer made of a photosensitive resin composition, (II) a step of exposing a desired pattern, and (III) It is obtained by a step of developing using an alkaline developer. That is, using a photosensitive resin varnish as a photosensitive resin varnish for forming a core part and a photosensitive resin varnish for forming a cladding layer, a method of laminating a photosensitive resin layer by a spin coating method, a photosensitive resin film, Examples thereof include a method of laminating a photosensitive resin layer by a laminating method using the resin film for forming a part and the resin film for forming a cladding layer. Moreover, it can also manufacture combining these methods. Among these, from the viewpoint that an optical waveguide manufacturing process with excellent productivity can be provided, a lamination method using a photosensitive resin film may be applied.

  Hereinafter, a manufacturing method for forming the optical waveguide 1 using the photosensitive resin film for the lower clad layer 4, the core portion 2, and the upper clad layer 3 will be described.

First, as a first step, the lower cladding layer 4 is formed by laminating a photosensitive resin film for forming a lower cladding layer on the substrate 5.
The laminating method in the first step includes a method of laminating by heating and pressing using a roll laminator, a flat plate laminator or the like. Among these, from the viewpoint of adhesion and followability, a photosensitive resin film for forming a lower cladding layer may be laminated under reduced pressure using a flat plate laminator. In the present invention, the flat plate type laminator refers to a laminator in which a laminated material is sandwiched between a pair of flat plates and pressed by pressing the flat plate. For example, a vacuum pressurizing flat plate type laminator can be used.
The heating temperature here may be, for example, 40 to 150 ° C., and the pressure bonding pressure may be 0.1 to 2.0 MPa, but is not particularly limited. When a protective film exists in the photosensitive resin film for forming the lower cladding layer, the protective film is laminated after removing the protective film.

In addition, you may temporarily stick the photosensitive resin film for lower clad layer formation on the base material 5 beforehand using a roll laminator before lamination | stacking by a vacuum pressurization type flat plate laminator.
Here, from the viewpoint of improving adhesion and followability, the film may be temporarily attached while being pressure-bonded, or may be heated while using a laminator having a heat roll. The laminating temperature may be 20 to 150 ° C or 40 to 130 ° C. When the temperature is 20 ° C. or higher, the adhesion between the lower clad layer forming photosensitive resin film and the substrate 5 tends to be improved, and when it is 150 ° C. or lower, the resin layer is too fluid during roll lamination. The required film thickness tends to be obtained. From the same point of view, the pressure during lamination may be, for example, 0.1 to 2.0 MPa, and the lamination speed may be 0.01 to 10 m / min, but is not particularly limited. Absent.

Subsequently, the lower clad layer forming photosensitive resin film laminated on the substrate 5 is cured by light and / or heat, and the lower clad layer forming photosensitive resin film is removed, and the lower clad layer is removed. 4 is formed.
The irradiation amount of actinic rays when forming the lower cladding layer 4 may be, for example, 10 to 5,000 mJ / cm ² and the heating temperature may be 30 to ²⁰⁰ ° C., but is particularly limited. It is not a thing.

Next, as a second step, the core portion forming photosensitive resin film is laminated in the same manner as in the first step. Here, the photosensitive resin film for forming the core part is designed to have a higher refractive index than the photosensitive resin film for forming the lower clad layer.
Since the photosensitive resin composition used by this invention hardens | cures with an actinic ray, it is suitable as a photosensitive resin film for core part formation.

  Next, as a third step, the laminated core-forming photosensitive resin film is exposed to form an optical waveguide core pattern (core portion 2). Specifically, an actinic ray is irradiated in an image form through a negative or positive mask pattern called an artwork. Moreover, you may irradiate an actinic ray directly to an image form, without passing through a photomask using laser direct drawing. Examples of the active light source include known light sources that effectively emit ultraviolet rays, such as carbon arc lamps, mercury vapor arc lamps, ultrahigh pressure mercury lamps, high pressure mercury lamps, and xenon lamps. In addition, there are those that effectively radiate visible light such as a photographic flood bulb and a solar lamp.

The dose of active light here may be a 10~10,000mJ / cm ^2, it may be 50~5,000mJ / cm ^2, even 100~3,000mJ / cm ² Good. When it is 10 mJ / cm ² or more, the curing reaction proceeds sufficiently, and the loss of the core part 2 due to the development process described later tends to be suppressed, and when it is 10,000 mJ / cm ² or less, the exposure amount is excessive. The core part 2 does not get thick and tends to form a fine pattern.
In addition, after exposure, you may perform post-exposure heating from a viewpoint of the resolution of the core part 2, and adhesive improvement. The time from ultraviolet irradiation to post-exposure heating may be within 10 minutes. If it is within 10 minutes, deactivation of active species caused by ultraviolet irradiation tends to be suppressed. The post-exposure heating temperature may be, for example, 40 to 200 ° C., and the heating time may be 30 seconds to 10 minutes, but is not particularly limited.

  After the exposure, the base film of the photosensitive resin film for forming the core part is removed, and the photosensitive resin film for forming the core part such as an alkaline aqueous solution is sprayed, rocking dipping, brushing, scraping, Development is performed by a known method such as dipping or paddle. Moreover, you may use together 2 or more types of image development methods as needed.

  The base of the alkaline aqueous solution is not particularly limited, but includes alkali metal-containing hydroxides such as lithium, sodium or potassium hydroxides; alkali metals such as lithium, sodium, potassium or ammonium carbonates or bicarbonates. -Containing carbonates; alkali metal-containing phosphates such as potassium phosphate and sodium phosphate; alkali metal-containing pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; sodium salts such as borax and sodium metasilicate; tetrahydroxide Examples thereof include organic bases such as methylammonium, triethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, and 1,3-diaminopropanol-2-morpholine. Of these, alkali metal-containing hydroxides, alkali metal-containing carbonates, alkali metal-containing phosphates, alkali metal-containing pyrophosphates, and the like may be used from the viewpoints of developability and environmental load reduction.

  The pH of the alkaline aqueous solution used for development may be 9 to 11, and the temperature may be adjusted in accordance with the developability of the photosensitive resin composition layer for forming the core part. Further, in the alkaline aqueous solution, a small amount of an organic solvent or the like for accelerating the surface active agent, antifoaming agent, development or the like may be mixed within a range not impairing the effects of the present invention.

As the processing after development, the core portion 2 may be cleaned using a cleaning liquid composed of water and the organic solvent as necessary.
As processing after development or washing, if necessary, the core portion 2 is further cured by heating at about 60 to 250 ° C. and / or exposing at about 10 to 10,000 mJ / cm ^2. Also good.

Subsequently, the upper clad layer 3 is formed by laminating a photosensitive resin film for forming the upper clad layer on the surface on which the core portion 2 is formed in the same manner as the first and second steps as the fourth step. To do. Here, the photosensitive resin film for forming the upper cladding layer is designed to have a lower refractive index than the photosensitive resin film for forming the core part. Further, the thickness of the upper clad layer 3 may be larger than the height of the core portion 2.
Next, the upper clad layer forming photosensitive resin film is cured by light and / or heat to form the upper clad layer 3 in the same manner as in the first step. When the material of the base film of the photosensitive resin film for forming the cladding layer is polyethylene terephthalate (PET), the irradiation amount of the active light may be 50 to 5,000 mJ / cm ² . On the other hand, when the material of the base film is polyethylene naphthalate, polyamide, polyimide, polyamideimide, polyetherimide, polyphenylene ether, polyether sulfide, polyethersulfone, polysulfone, etc., it has a shorter wavelength such as ultraviolet rays than PET. Since it is difficult to transmit actinic rays, the irradiation amount of actinic rays may be 100 to 30,000 mJ / cm ² . When the irradiation amount is 100 mJ / cm ² or more, the curing reaction tends to proceed sufficiently, and when it is 30,000 mJ / cm ² or less, the light irradiation time does not take too long.

In order to further advance the curing reaction, a double-side exposure machine capable of simultaneously irradiating actinic rays from both sides may be used. Moreover, you may irradiate actinic light, heating. The heating temperature during or after actinic ray irradiation may be, for example, 40 to 200 ° C., but is not particularly limited.
After forming the upper cladding layer 3, the base film can be removed if necessary to produce the optical waveguide 1.

  Since the optical waveguide according to the present invention is excellent in heat resistance and transparency, it may be used as an optical transmission line of an optical module. The optical module is composed of an optical waveguide with an optical fiber in which optical fibers are connected to both ends of the optical waveguide, an optical waveguide with a connector in which connectors are connected to both ends of the optical waveguide, and an optoelectric device in which the optical waveguide and a printed wiring board are combined. Examples include a composite substrate, an optical / electrical conversion module that combines an optical waveguide and an optical / electrical conversion element that mutually converts an optical signal and an electrical signal, and a wavelength multiplexer / demultiplexer that combines an optical waveguide and a wavelength division filter. In the photoelectric composite substrate, the printed wiring board to be combined is not particularly limited, and either a rigid substrate such as a glass epoxy substrate or a flexible substrate such as a polyimide substrate may be used.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

(Synthesis example 1) [Preparation of (meth) acrylic polymer (P-1)]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, 46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate were weighed and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 47 parts by mass of methyl methacrylate, 33 parts by mass of butyl acrylate, 16 parts by mass of 2-hydroxyethyl methacrylate, 14 parts by mass of methacrylic acid, 2,2′-azobis (2,4-dimethylvaleronitrile ) A mixture of 3 parts by mass, 46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours, and further stirring at 95 ° C. for 1 hour. A (meth) acrylic polymer (P-1) solution (solid content: 47% by mass) was obtained. Hereinafter, the (meth) acrylic polymer (P-1) solution is also referred to as “P-1 solution”.
The obtained (meth) acrylic polymer (P-1) had an acid value of 79 mgKOH / g and a weight average molecular weight of 39,000.

(Synthesis example 2) [Preparation of (meth) acrylic polymer (P-2)]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, 42 parts by mass of propylene glycol monomethyl ether acetate and 21 parts by mass of methyl lactate were weighed and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 14.5 parts by mass of N-cyclohexylmaleimide, 20 parts by mass of benzyl acrylate, 39 parts by mass of o-phenylphenol 1.5EO acrylate, 14 parts by mass of 2-hydroxyethyl methacrylate, 12. After dropping a mixture of 5 parts by mass, 4 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile), 37 parts by mass of propylene glycol monomethyl ether acetate, and 21 parts by mass of methyl lactate over 3 hours, 65 ° C. The mixture was further stirred at 95 ° C. for 1 hour to obtain a (meth) acrylic polymer (P-2) solution (solid content: 45 mass%). Hereinafter, the (meth) acrylic polymer (P-2) solution is also referred to as “P-2 solution”.
The acid value of the obtained (meth) acrylic polymer (P-2) was 82 mgKOH / g, and the weight average molecular weight was 32,000.

(Production Example 1) [Preparation of photosensitive resin varnish CLV-1 for forming clad layer]
37 parts of the P-1 solution (solid content: 47% by mass), 84 parts by mass (solid content: 40 parts by mass), carboxy group-containing urethane diacrylate (manufactured by Hitachi Chemical Co., Ltd., trade name: HA9082-95, solid content: 76% by mass) Mass parts (solid content 28 parts by mass), urethane trimethacrylate (trade name FA-731M, manufactured by Hitachi Chemical Co., Ltd.) having an isocyanuric ring structure, 20 parts by mass (solid content 20 parts by mass), and hexamethylene diisocyanate type trimer Is a blocked isocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Sumijoule (registered trademark) BL3175, solid content 75% by mass) 16 parts by mass (solid content 12 parts by mass), a photopolymerization initiator 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propyl Pan-1-one (manufactured by BASF Japan, trade name: Irgacure (registered trademark) 2959) 1 part by mass, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by BASF Japan, trade name: 1 part by mass of Irgacure (registered trademark) 819) and 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent for dilution were mixed with stirring. The obtained solution was subjected to pressure filtration using a polyflon filter having a pore size of 2 μm (trade name: PF020, manufactured by Advantech Toyo Co., Ltd.), degassed under reduced pressure, and photosensitive resin varnish CLV-1 for forming a cladding layer. Got.

(Production Example 2) [Production of Clad Layer Forming Photosensitive Resin Film CLF-1]
On the non-treated surface of the clad layer forming photosensitive resin varnish CLV-1 obtained above is a base film PET film (manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine (registered trademark) A4100, thickness 50 μm). The film was applied using a coating machine (trade name: Multicoater TM-MC, manufactured by Hirano Techseed Co., Ltd.), dried at 100 ° C. for 20 minutes, and then surface-released PET film (manufactured by Teijin DuPont Films, Ltd.) as a protective film , Trade name: PUREX (registered trademark) A31, thickness 25 μm) was applied to obtain a photosensitive resin film CLF-1 for forming a cladding layer.
At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine.
The thickness of the photosensitive resin film for forming the upper cladding layer obtained in this production example was 70 μm, and the thickness of the photosensitive resin film for forming the lower cladding layer was 30 μm.
The refractive index of the clad layer forming photosensitive resin film CLF-1 was 1.497 as measured by the method described below.

(Production Example 3) [Preparation of photosensitive resin varnish COV-1 for forming core part]
As the component (A), carboxylic acid-modified bisphenol A / urethane type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: KARAYAD (registered trademark) UXE-3024, weight average molecular weight: 1.0 × 10 ⁴ , acid value: As a component (B), bisphenol A type epoxy monoacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: EA-1010N) (60 mg KOH / g, solid content 71.9% by mass) 70 parts by mass (solid content 50 parts by mass) , Epoxy equivalent 518 g / eq) 15 parts by mass (solid content 15 parts by mass), bisphenol A type epoxy diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: EA-1020) 20 parts by mass (solid content 20 parts by mass) , EO-modified bisphenolfluorene diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: A-BPEF) 15 1 part by mass (solid content 15 parts by mass) and (C) component, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (BASF Japan Ltd.) Manufactured, trade name: Irgacure (registered trademark) 2959) 1 part by mass, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by BASF Japan, trade name: Irgacure (registered trademark) 819) 1 part by mass As component (D), pentaerythritol tetrakis (3-mercaptobutyrate) (manufactured by Showa Denko KK, trade name: Karenz (registered trademark) MT-PE1) 5 parts by mass (solid content 5 parts by mass), and as a diluent solvent Propylene glycol monomethyl ether acetate was added to a solid content of 55% by mass and mixed with stirring. The obtained solution was subjected to pressure filtration using a polyflon filter having a pore diameter of 2 μm (trade name: PF020, manufactured by Advantech Toyo Co., Ltd.), degassed under reduced pressure, and photosensitive resin varnish COV-1 for core formation. (Solid content 55% by mass) was obtained.

(Production Example 4) [Preparation of photosensitive resin varnish COV-2 for forming core part]
(D) The core part forming photosensitive resin varnish COV-2 was obtained in the same manner as the core part forming photosensitive resin varnish COV-1, except that the amount of the component chain transfer agent was changed to 3 parts by mass. .

(Production Example 5) [Preparation of photosensitive resin varnish COV-3 for core formation]
(D) The core part is formed in the same manner as the photosensitive resin varnish COV-1 for forming a core part except that the components (A) to (C) used in COV-1 are mixed without adding the chain transfer agent. A forming resin varnish COV-3 was obtained.

(Production Example 6) [Preparation of photosensitive resin varnish COV-4 for forming core part]
Among the components (A) to (C) used in the core part-forming resin varnish COV-3, (B) as a compound having a polymerizable group, a bisphenol A type epoxy monoacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product) Name: EA-1010N) Core part formation in the same manner as the core part forming photosensitive resin varnish COV-3, except that it was replaced with bisphenol A type epoxy resin (DICICON (registered trademark) 850, manufactured by DIC Corporation) Photosensitive resin varnish COV-4 was obtained.

(Production Example 7) [Photosensitive resin varnish COV-5 for forming core part]
(A) 133 parts by mass (solid content 45.0% by mass) of the P-2 solution (solid content 45.0% by mass) as component (B), and bisphenol A type epoxy monoacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) as component (B) Product name: EA-1010N, epoxy equivalent 518 g / eq) 40 parts by mass (solid content 40 parts by mass), (C) as component 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2- 1 part by mass of methyl-1-propan-1-one (manufactured by BASF Japan Ltd., trade name: Irgacure (registered trademark) 2959), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by BASF Japan Ltd.) , Trade name: Irgacure (registered trademark) 819) 1 part by mass, and propylene glycol monomethyl ether acetate as a diluent solvent In addition to the door is solid becomes 55 wt%, to obtain a photosensitive resin varnish COV-5 core portion formed in the same manner as the core portion forming photosensitive resin varnish COV-1.

(Production Example 8) [Preparation of photosensitive resin film COF-1 for forming a core part]
On the non-treated surface of the core part-forming photosensitive resin varnish COV-1 obtained above, a PET film (trade name: Cosmo Shine (registered trademark) A1517, thickness 16 μm, manufactured by Toyobo Co., Ltd.) as a base film. The film was applied using the coating machine, dried at 80 ° C. for 10 minutes, and at 100 ° C. for 10 minutes, and then surface-released PET film as a protective film (trade name: Purex (registered by Teijin DuPont Films, Ltd.)) (Trademark) A31, thickness 25 μm) was pasted to obtain a photosensitive resin film COF-1 for forming a core part.
The thickness of the resin layer of the photosensitive resin film for forming the core part can be arbitrarily adjusted by adjusting the gap of the coating machine, but in this example, the thickness after curing was adjusted to 50 μm. .

(Production Example 9) [Preparation of core part-forming photosensitive resin film COF-2 to 5]
Core-forming photosensitive resin films COF-2 to 5 were obtained in the same manner as the core-forming photosensitive resin film COF-1.

[Production of optical waveguide]
Hereinafter, the manufacturing method of the optical waveguide will be described with reference to Example 1 shown in Table 1 below. In addition, Examples 2-4 and Comparative Examples 1-3 were produced similarly.
Using the vacuum pressure laminator (product name: V130, manufactured by Nichigo Morton Co., Ltd.), the above-mentioned lower clad forming photosensitive material with the protective film removed under conditions of a pressure of pressure of 0.5 MPa, a temperature of 80 ° C. and a pressure time of 30 seconds. The functional resin film CLF-1 on a glass epoxy resin substrate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL (registered trademark) -E-679-FB, thickness 0.6 mm, surface copper foil removed by etching) Laminated. Next, using an ultraviolet exposure machine (trade name: MAP-1200, manufactured by Dainippon Screen Co., Ltd.), the substrate film is removed after irradiating 4,000 mJ / cm ^{2 of} ultraviolet rays (wavelength 365 nm) from above the substrate film. The lower clad layer 4 was formed by heat treatment at 105 ° C. for 10 minutes and 170 ° C. for 1 hour.

Subsequently, using a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., trade name: HLM-1500), the core-forming photosensitive resin film COF-1 from which the protective film has been removed is pressure-bonded onto the lower cladding layer 4. Lamination was performed under the conditions of a pressure of 0.5 MPa, a temperature of 50 ° C., and a speed of 0.2 m / min. Next, the core part 2 (core pattern) is exposed through a negative photomask having an optical waveguide forming pattern with a width of 50 μm by irradiating the substrate film with ultraviolet rays (wavelength 365 nm) of 500 mJ / cm ² by the ultraviolet exposure machine. did. After removing the base film, the film was developed with a 1% by mass aqueous potassium carbonate solution at a temperature of 30 ° C. and a spray pressure of 0.15 MPa using a spray developing device (trade name: RX-40D, manufactured by Yamazaki Kikai Co., Ltd.). . Then, it wash | cleaned with the pure water and heat-processed at 80 degreeC for 10 minutes and 160 degreeC for 1 hour.

Next, using the vacuum laminator, the upper clad layer-forming photosensitive resin film CLF-1 from which the protective film has been removed is applied onto the core portion 2 and the lower clad layer 4 at a pressure of 0.5 MPa, a temperature of 85 ° C., and an applied pressure. Lamination was performed under a pressure time of 90 seconds. Next, after irradiating the substrate film with ultraviolet rays (wavelength 365 nm) at 4,000 mJ / cm ² with the above-described ultraviolet exposure machine to remove the substrate film, heat treatment was performed at a temperature of 170 ° C. for 1 hour, and the upper cladding layer 3 To obtain the optical waveguide 1 shown in FIG. Thereafter, a rigid optical waveguide having a length of 10 cm was cut out using a dicing saw (trade name: DAD-3350, manufactured by DISCO Corporation).

  Hereinafter, a method for evaluating each characteristic will be described.

[Measurement of refractive index]
The photosensitive resin film for forming a cladding layer from which the protective film has been removed is irradiated with 4,000 mJ / cm ² of ultraviolet rays (wavelength 365 nm) with the ultraviolet exposure machine, then at 105 ° C. for 10 minutes, then at 170 ° C. for 1 By heating for a time, a cured product of the photosensitive resin film for forming the clad layer was obtained.
The photosensitive resin film for forming the core part from which the protective film has been removed is irradiated with 4,000 mJ / cm ² of ultraviolet rays (wavelength 365 nm) with the ultraviolet exposure machine, then at 80 ° C. for 10 minutes, and then 160 ° C. And heated for 1 hour to obtain a cured product of the photosensitive resin film for forming the core part.
The obtained hardened | cured material was cut | disconnected to size 30 mm in length and 30 mm in width, respectively, and the sample for refractive index measurement was produced. The refractive index of the sample at a wavelength of 830 nm was measured using a prism-coupled refractometer (manufactured by Metricon, trade name: Model 2020). Table 1 shows the refractive index of the cured product of each core portion forming photosensitive resin film.

[Measurement of swelling degree]
The degree of swelling is determined by laminating each core part forming photosensitive resin film on a quartz crystal resonator (manufactured by INFICON) using the roll laminator, and using a quartz crystal film thickness monitor (manufactured by Maxtec) to form a photosensitive resin composition. The frequency of the object and the crystal resonator was measured and used as the initial frequency. Then, it immersed in alkaline aqueous solution, the frequency change of each photosensitive resin composition and a crystal oscillator was measured, and the swelling degree was computed. Table 1 shows the degree of swelling in the alkaline aqueous solution of the cured product of the photosensitive resin film for forming each core part.
The degree of swelling was calculated by the following formula.

    Swelling degree (%) = [(frequency of photosensitive resin composition and crystal resonator at arbitrary immersion time) − (frequency when crystal resonator is immersed in alkaline aqueous solution)] / [(initial frequency) − (Frequency specific to crystal unit)] × 100

[Measurement of optical propagation loss]
The optical propagation loss of the optical waveguide obtained by the above method is a VCSEL (Vertical Cavity Surface Emitting Laser) light source (product name: FLS-300-01-VCL) manufactured by EXFO having a wavelength of 850 nm as a central wavelength, light reception Sensor (manufactured by Advantest Corporation, trade name: Q82214), incident fiber (GI-50 / 125 multimode fiber, NA = 0.20), and outgoing fiber (SI-114 / 125 multimode fiber, NA = 0.22) ). The optical propagation loss was calculated by dividing the measured optical loss (dB) by the optical waveguide length (10 cm). Each light propagation loss is shown in Table 1.

  The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 3 are summarized in Table 1.

  The photosensitive resin composition used in the method for producing an optical waveguide of the present invention is a resin composition containing a chain transfer agent as component (D), and Examples 1 to 4 are (D) as in Comparative Example 1. It was found that the degree of swelling with respect to an alkaline aqueous solution containing an alkali metal can be reduced to 10% by mass or less as compared with a photosensitive resin composition containing no component chain transfer agent. Furthermore, it turns out that the optical waveguide produced using the resin composition containing the chain transfer agent of (D) component is excellent in light propagation property compared with Comparative Examples 1-3.

  The photosensitive resin composition used in the method for producing an optical waveguide of the present invention and the photosensitive resin film comprising the photosensitive resin composition can suppress swelling due to an alkaline aqueous solution containing an alkali metal, and an optical waveguide produced using them. The waveguide is excellent in transparency at a wavelength of 850 nm, low light propagation loss, and the like. Therefore, the present invention can be applied as having excellent characteristics in various fields such as various optical devices and optical interconnections.

DESCRIPTION OF SYMBOLS 1 Optical waveguide 2 Core part 3 Upper clad layer 4 Lower clad layer 5 Base material (or support film)

Claims (6)

  An optical waveguide comprising a lower clad layer, a core portion, and an upper clad layer, wherein the core portion is (I) a step of laminating a photosensitive resin layer made of a photosensitive resin composition, and (II) exposing a desired pattern. An optical waveguide using a photosensitive resin composition comprising a step and (III) a step of developing using an alkaline developer, wherein the swelling degree of the photosensitive resin layer in the alkaline developer is 10% by mass or less Production method.   The method for producing an optical waveguide according to claim 1, wherein the alkaline developer is an aqueous solution containing an alkali metal.   A resin in which the photosensitive resin layer comprising the photosensitive resin composition comprises (A) a compound having an acidic group, (B) a compound having a polymerizable group, (C) a photopolymerization initiator, and (D) a chain transfer agent. The manufacturing method of the optical waveguide of Claim 1 or Claim 2 which consists of a composition.   The method for producing an optical waveguide according to claim 3, wherein the (C) photopolymerization initiator is a photoradical initiator.   The method for producing an optical waveguide according to claim 3, wherein the (D) chain transfer agent is a compound containing a sulfur atom.   The method for manufacturing an optical waveguide according to claim 1, wherein the light propagation loss is 0.20 dB / cm or less.

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