JP2016224196A - Resin composition for forming optical waveguide cores and optical waveguide produced using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for forming optical waveguide cores, which can be developed using dilute alkaline aqueous solution and provides cores having superior transparency and flexibility.SOLUTION: A resin composition for forming optical waveguide cores contains; (A) a polythiourethane poly(meth)acrylate obtained through reactions among (a) a polythiocarbonate polythiol, (b) an acid group-containing polyol and/or acid group-containing polythiol (d) a polyisocyanate or polyiso(thio)cyanate, and (e) a hydroxyl-containing (meth)acrylate; and (C) a photopolymerization initiator, where the (A) polythiourethane poly(meth)acrylate has an acid number of 20-200 mgKOH/g.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition for forming a core of an optical waveguide, and relates to a resin composition for forming a core that can be developed with a dilute aqueous alkali solution and provides a core excellent in transparency and flexibility.

  In recent years, the limits of electric wiring are approaching due to problems such as power consumption, design freedom, electromagnetic noise, and wiring space. As one means for solving this problem, attention has been focused on optical interconnection that connects between electronic elements and wiring boards with light. Quartz has been used as a conventional optical waveguide, but polymer optical waveguides have been widely studied due to workability problems.

  Regarding the optical waveguide manufacturing process, a method capable of easily forming the core pattern is required, and one of them is photolithography widely used in the printed wiring board process.

  The material described in Patent Document 1 is described using photolithography, high alkali developability, and excellent flexibility, but uses only tetramethylammonium hydroxide as an alkali developer, and dilute alkali. The developability with a developer (for example, 1% sodium carbonate aqueous solution) was unknown.

  In Patent Document 2, an optical waveguide is produced by photolithography using a photocurable resin composed of a urethane (meth) acrylate oligomer, a reactive dilution monomer, elastomer particles, and a photopolymerization initiator, and the flex resistance is improved. However, it was solvent development. Further, the difference in refractive index is not sufficiently described, and it is unknown whether the necessary refractive index difference can be obtained at the bent portion.

In Patent Document 3, a resin for forming an optical waveguide excellent in storage stability and alkali developability is produced by a resin composition for forming an optical waveguide comprising a polymer having a carboxyl group, an acrylate, and a polyfunctional block isocyanate compound. However, no mention was made of the bending resistance after the resin composition was cured.
In Patent Document 4, an optical waveguide having high bending durability is described, but the bending property of the core material is not mentioned, and it is solvent development.

JP 2009-244627 A JP 2009-157125 A JP 2011-1117988 A JP 2009-199076 A

  An object of the present invention is to provide a core-forming resin composition that can be developed with a dilute alkaline aqueous solution and that provides a core having excellent transparency and flexibility.

  As a result of intensive studies to solve the above problems, the present inventors have found that a core-forming resin composition containing a polythiourethane poly (meth) acrylate having a specific structure and physical properties and a photopolymerization initiator is described above. The present invention has been found out to solve the problems.

Specifically, the present invention is as follows.
(1) (a) polythiocarbonate polythiol, (b) acidic group-containing polyol or / and acidic group-containing polythiol, (d) polyisocyanate or / and polyisothiocyanate, (e) hydroxyl group-containing (meth) acrylate (A) polythiourethane poly (meth) acrylate obtained by reacting with (C) a photopolymerization initiator, and (A) the acid value of polythiourethane poly (meth) acrylate is 20 to 200 mgKOH / The resin composition for core formation of an optical waveguide which is g.

（式中、Ｒは二価の炭化水素基を表し、置換基を有していてもよく、その炭素鎖中にヘテロ原子を含有していてもよい。） (2) (a) The core of the optical waveguide according to (1), wherein the polythiocarbonate polythiol is a polythiocarbonate polythiol having a repeating unit represented by the chemical formula (I) and having a number average molecular weight of 200 to 2500 Resin composition for forming.

(In the formula, R represents a divalent hydrocarbon group, which may have a substituent, and may contain a hetero atom in the carbon chain.)

  (3) The resin composition for forming a core of an optical waveguide according to (1) or (2), further comprising (B) a (meth) acrylate having a molecular weight of less than 1000 and having one or more (meth) acryloyl groups in the molecule .

  (4) The blending amount of component (A) is 50 to 90% by mass with respect to the total amount of components (A) to (B), and the blending amount of component (B) is the total amount of components (A) to (B). The blending amount of the component (C) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (B). A resin composition for forming an optical waveguide core.

  (5) An optical waveguide including a core portion and a cladding layer, wherein the core portion is a cured product of the core-forming resin composition according to any one of (1) to (4). Waveguide.

  According to the present invention, it is possible to provide a core-forming resin composition that can be developed with a dilute aqueous alkali solution and that provides a core having excellent transparency and flexibility.

FIG. 1 is a cross-sectional view showing an example of an optical waveguide according to the present invention.

(Resin composition for core formation of optical waveguide)
An optical waveguide core-forming resin composition (hereinafter also simply referred to as “core-forming resin composition”) includes (a) a polythiocarbonate polythiol and (b) an acidic group-containing polyol or / and an acidic group-containing polythiol. And (d) polyisocyanate or / and polyisothiocyanate and (e) a hydroxyl group-containing (meth) acrylate, (A) polythiourethane poly (meth) acrylate, and (C) photopolymerization initiation The acid value of (A) polythiourethane poly (meth) acrylate is 20 to 200 mg KOH / g.
Below, each component is demonstrated.

<(A) Polythiocarbonate polythiol>
(A) Polythiocarbonate Polythiol is a polythiol containing a repeating unit having a thiocarbonate bond and having a thiol group (SH group) at the molecular end. (A) As a polythiocarbonate polythiol, the polythiocarbonate polythiol which does not have an ester bond (-C (= O) -O-) in a molecule | numerator from a point of alkali resistance is preferable.

  (A) The polythiocarbonate polythiol preferably has a number average molecular weight of 200 to 2500. When the number average molecular weight is 200 or more, the performance as a soft segment is improved, and there is a tendency that the coating film formed using the core-forming resin composition is hardly cracked. When the number average molecular weight is 2500 or less, the reactivity between (a) polythiocarbonate polythiol and (d) polyisocyanate or / and polyisothiocyanate is improved, and the reaction tends to proceed sufficiently. Moreover, since (a) polythiocarbonate polythiol has fluidity | liquidity at room temperature, there exists a tendency for a handleability to improve.

The mercapto group value of polythiocarbonate polythiol is calculated | required with the following method.
Mercapto group value (SH value; mgKOH / g): 100 mL (milliliter) Weigh the sample in a sample bottle (mass is accurately read to the fourth decimal place in grams) and acetic anhydride-tetrahydrofuran solution (anhydrous in 100 mL solution) 5 mL of acetic acid (containing 4 g) and 4-dimethylaminopyridine-tetrahydrofuran solution (containing 1 g of 4-dimethylaminopyridine in 100 mL of solution) were added accurately to completely dissolve the sample, and then stirred at room temperature for 1 hour. Then, 1 mL of ultrapure water was accurately added and stirred at room temperature for 30 minutes, and titrated with a 0.5 M potassium hydroxide-ethanol solution (indicator: phenolphthalein). The SH value was calculated by the following formula.
SH value (mgKOH / g) = 28.05 × (BA) / S
(In the formula, S is the amount of sample collected (g), A is the amount of 0.5M potassium hydroxide-ethanol solution (mL) required for the titration of the sample, and B is 0.5M hydroxide required for the blank test. (Represents the amount (mL) of potassium-ethanol solution.)

The number average molecular weight (Mn) of polythiocarbonate polythiol is calculated | required by following Formula from SH value.
Mn = (56100 × valence) / SH value In the above formula, the valence is the number of SH groups in one molecule, and the valence is 2 when the polythiocarbonate polythiol is polythiocarbonate dithiol.

(A) The structure of the repeating unit of polythiocarbonate polythiol includes the following types, and may have any repeating unit. In the structural formula of each repeating unit, R represents a divalent hydrocarbon group, may have a substituent, and may contain a hetero atom in the carbon chain.

Among these, polythiocarbonate polythiol having the following structure is preferable as a repeating unit from the viewpoint of relatively easy acquisition and production of raw materials.

The polythiocarbonate polythiol can be produced by various methods, but it is desirable to produce the polythiocarbonate polythiol by subjecting the polythiol compound and the carbonate compound to an ester exchange reaction in the presence of an ester exchange catalyst.
Examples of the carbonate compound include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, di-n-butyl carbonate and diisobutyl carbonate, diaryl carbonates such as diphenyl carbonate, alkylene carbonates such as ethylene carbonate and propylene carbonate, and methylphenyl carbonate. And alkyl aryl carbonates. Among the carbonate compounds, diaryl carbonate is preferable, and diphenyl carbonate is particularly preferable.

  As the polythiol compound, a polythiol compound corresponding to the polyol compound used in the production of polycarbonate polyol can be used. Specifically, a mercapto group is bonded to the terminal of a polyvalent (at least divalent) hydrocarbon group. Compounds. This hydrocarbon group includes an aliphatic hydrocarbon group (preferably having 2 to 14 carbon atoms), an alicyclic hydrocarbon group (preferably having 3 to 14 carbon atoms), an aromatic (including araliphatic) hydrocarbon group ( Preferably, it may have any of 6 to 14 carbon atoms, and may have a substituent (alkyl group, nitro group) which does not participate in the reaction, and in the carbon chain, a hetero atom (oxygen atom, sulfur atom) , Nitrogen atoms, etc.) or other atoms or groups that do not participate in the reaction. If the polyvalent hydrocarbon group is a divalent hydrocarbon group, “R” in the structural formula of the repeating unit corresponds to this hydrocarbon group. Therefore, R is preferably an aliphatic hydrocarbon group having 2 to 14 carbon atoms, an alicyclic hydrocarbon group having 3 to 14 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, or 6 carbon atoms. -14 araliphatic hydrocarbon groups. These groups may have a substituent and may contain a hetero atom in the carbon chain.

  Examples of the polythiol compound in which the hydrocarbon group is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5 -Pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,12-dodecanedithiol, 2,2- Alkanedithiols such as dimethyl-1,3-propanedithiol, 3-methyl-1,5-pentanedithiol, 2-methyl-1,8-octanedithiol, 1,4-cyclohexanedithiol, 1,4-bis (mercapto) Cycloalkanedithiol such as methyl) cyclohexane and bis (2-mercaptoethyl) ether , Alkanedithiols having heteroatoms such as bis (2-mercaptoethyl) sulfide, bis (2-mercaptoethyl) disulfide, 2,2 ′-(ethylenedithio) diethanethiol, and 2,5-bis (mercaptomethyl) Cycloalkanedithiol having a heteroatom such as -1,4-dioxane, 2,5-bis (mercaptomethyl) -1,4-dithiane, 2,5-bis (mercaptoethylthio) -1,4-dithiane, Alkanetrithiol such as 1,1,1-tris (mercaptomethyl) ethane, 2-ethyl-2-mercaptomethyl-1,3-propanedithiol, tetrakis (mercaptomethyl) methane, 3,3′-thiobis (propane) -1,2-dithiol), 2,2′-thiobis (propane-1,3-dithiol) and the like And down tetrathiol pentaerythritol tetrakis (mercaptopropionate), alkane tetrakis such pentaerythritol tetrakis (mercaptoacetate) (mercapto alkylate) and the like.

  Examples of the polythiol compound in which the hydrocarbon group is an aromatic hydrocarbon group include 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,2-bis (mercaptomethyl) benzene, 1,3-bis (mercaptomethyl) benzene, 1,4-bis (mercaptomethyl) benzene, arenedithiol (aromatic dithiol) such as toluene-3,4-dithiol, 1,3,5-benzenetrithiol, Examples include arenetrithiols (aromatic trithiols) such as 1,3,5-tris (mercaptomethyl) benzene.

  One type of polythiol compound may be used, or a plurality of types may be used in combination. In the latter case, for example, if a polythiol compound having the following combination is used, a liquid polythiocarbonate polythiol having a low melting point and a low crystallization temperature at room temperature (10 to 40 ° C.) can be obtained. Examples of the polythiol compound include the following combinations. Such a liquid polythiocarbonate polythiol is very useful in practice, such as enabling solution polymerization at room temperature.

A combination of aliphatic linear dithiols having different carbon chain lengths: a combination of 1,5-pentanedithiol and 1,6-hexanedithiol, a mercaptoalkyl sulfide (for example, bis (2-mercaptoethyl) sulfide) and 1 Combination with 6-hexanedithiol, etc.
-Combination of aliphatic linear dithiol and aliphatic branched polythiol: Combination of 1,6-hexanedithiol and 3-methyl-1,5-pentanedithiol, etc.
A combination of an aliphatic linear dithiol or an aliphatic branched polythiol and an alkanedithiol having an aliphatic hydrocarbon ring: a combination of 1,6-hexanedithiol and 1,4-bis (mercaptomethyl) cyclohexane.
A combination of an aliphatic linear dithiol or aliphatic branched polythiol and an alkanedithiol having a heteroatom and an aliphatic hydrocarbon ring: 1,6-hexanedithiol and 2,5-bis (mercaptomethyl) -1,4 -Combination with dithiane and / or 2,5-bis (mercaptoethylthio) -1,4-dithiane, etc.

  A polythiocarbonate polythiol is produced by subjecting a carbonic acid ester compound (especially diaryl carbonate) and a polythiol compound to an ester exchange reaction while continuously extracting alcohol (especially aryl alcohol) as a by-product in the presence of a transesterification catalyst. It is preferable. At this time, the polythiol compound is used in an amount of 0.8 to 3.0 times mol of the carbonate compound so that all or almost all of the terminals of the resulting polythiocarbonate polythiol molecular chain are mercapto groups. Is preferably 0.85 to 2.5 times mol, particularly 0.9 to 2.5 times mol. Moreover, it is preferable that the usage-amount of a transesterification catalyst is 1-5000 ppm on a molar basis with respect to a polythiol compound, Furthermore, it is preferable that it is 10-1000 ppm.

  The conditions (temperature, pressure, time) of the transesterification reaction are not particularly limited as long as the target product can be generated. However, in order to efficiently generate the target product, the ester carbonate compound and the polythiol compound are esterified. In the presence of the exchange catalyst, the reaction is carried out at 110 to 200 ° C. for about 1 to 24 hours under normal pressure or reduced pressure, and then at 110 to 240 ° C. (especially 140 to 240 ° C.) for about 0.1 to 20 hours under reduced pressure. It is preferable to carry out the reaction for about 0.1 to 20 hours under a reduced pressure that finally becomes 20 mmHg (2.7 kPa) or less while gradually increasing the degree of vacuum at the same temperature. In addition, when a plurality of polythiol compounds are used, a corresponding polythiocarbonate polythiol may be produced by transesterifying the carbonate compound and the polythiol compound under the same conditions, and another polythiol compound may be reacted therewith. . At this time, if the carbonic acid ester compound is diphenyl carbonate, diphenyl carbonate and a polythiol compound having 4 to 14 carbon atoms are transesterified, and then the polythiocarbonate polythiol to be produced and the polythiol compound having 2 to 5 carbon atoms It is preferable to produce the target product by reacting. In order to extract the by-product alcohol, it is preferable to provide a distillation apparatus in the reactor, and the reaction may be performed under a flow of an inert gas (nitrogen, helium, argon, etc.).

The transesterification catalyst is not particularly limited as long as it is a compound that promotes the transesterification reaction. For example, basic compounds such as potassium carbonate, sodium alkoxide (sodium methoxide, sodium ethoxide, etc.), quaternary ammonium salts (tetraalkylammonium hydroxide such as tetrabutylammonium hydroxide), titanium tetrachloride, tetraalkoxy titanium, etc. Titanium compounds such as (tetra-n-butoxy titanium, tetraisopropoxy titanium, etc.), metal tin, tin hydroxide, tin chloride, dibutyl tin dilaurate, dibutyl tin oxide, butyl tin tris (2-ethylhexanoate), etc. The tin compound is mentioned. The transesterification catalyst is preferably a quaternary ammonium salt and more preferably a tetraalkylammonium hydroxide from the viewpoint that the reaction rate can be further increased.
One type of transesterification catalyst may be used, or a plurality of types may be used in combination.

<(B) Acid group-containing polyol or / and acid group-containing polythiol>
(B) The acidic group-containing polyol or / and the acidic group-containing polythiol contains two or more hydroxyl groups or / and mercapto groups and one or more acidic groups in one molecule. Examples of the acidic group include a carboxy group, a sulfonic acid group, a phosphoric acid group, and a phenolic hydroxyl group. (B) One kind of acidic group-containing polyol or / and acidic group-containing polythiol may be used, or a plurality of kinds may be used in combination.

  Specific examples of the acidic group-containing polyol having two or more hydroxyl groups in one molecule include dimethylol alkanoic acids such as 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid; N, N -Bishydroxyethylglycine, N, N-bishydroxyethylalanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid and the like. Among these, from the viewpoint of easy availability, alkanoic acids having 4 to 12 carbon atoms (dimethylol alkanoic acid) containing two methylol groups are preferable. Among dimethylol alkanoic acids, 2,2-dimethylolpropionic acid is more preferable. preferable.

Specific examples of the acidic group-containing polythiol having two or more mercapto groups in one molecule include 3-mercapto-2- (mercaptomethyl) 2-methylpropionic acid, 2,2-bismercaptomethylpropionic acid, And bismercaptomethylalkanoic acid such as 2,2-bismercaptomethylbutanoic acid.
As described in International Publication No. 98/023606, for example, by acylating the hydroxyl group of 2,2-dimethylolpropionic acid, then halogenating, thioacetylating, deacetylating, etc. can get.

  (B) Acidic group-containing polyol or / and acidic group-containing polythiol have an acidic group containing a compound having two hydroxyl groups and one carboxy group in one molecule from the viewpoint of industrial availability. Polyols are preferred.

<(C) Polyol or / and polythiol other than (a) and (b)>
(C) As the polyol or / and polythiol other than (a) and (b), for example, a high molecular weight diol, a high molecular weight dithiol, a low molecular weight diol or a low molecular weight dithiol can be used. (C) Polyols and / or polythiols other than (a) and (b) are chain extensions that react with (d) polyisocyanate or / and polyisothiocyanate during the synthesis of (A) polythiourethane poly (meth) acrylate. It works as an agent and forms a hard segment. (C) One type of polyol or / and polythiol other than (a) and (b) may be used, or a plurality of types may be used in combination.

The high molecular weight diol is not particularly limited as long as the number average molecular weight is 400 to 4000. For example, polycarbonate diol, polyester diol, polyether diol and the like can be used.
The polycarbonate diol is not particularly limited, but specifically, an aliphatic polycarbonate diol such as polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyhexamethylene carbonate diol, poly 1,4-xylylene carbonate diol, etc. Aromatic polycarbonate diol, polycarbonate diol which is a reaction product of a plurality of types of aliphatic diols and carbonates, and polycarbonate diol and aliphatic diol which are reaction products of aliphatic diols, aromatic diols and carbonates Examples thereof include copolymer polycarbonate diols such as polycarbonate diol which is a reaction product of dimer diol and carbonate. Examples of the aliphatic diol include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. Examples of the aromatic diol include 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,4-dihydroxybenzene, and the like. Polyester diol is not particularly limited, and specifically, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene seba Examples thereof include ketodiol, polybutylene sebacate diol, poly-ε-caprolactone diol, poly (3-methyl-1,5-pentylene adipate) diol, polycondensate of 1,6-hexanediol and dimer acid, and the like. . The polyether diol is not particularly limited, and specific examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and propylene oxide, random copolymer and block copolymer of ethylene oxide and butylene oxide, and the like. . Further, a polyether polyester polyol having an ether bond and an ester bond may be used.

  The low molecular weight diol is not particularly limited as long as the number average molecular weight is 60 or more and less than 400. For example, ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2- Dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1 , 6-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, diethylene glycol, triethylene glycol, tetraethylene glycol and other aliphatic diols having 2 to 9 carbon atoms; 1,4-cyclohexane Dimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-bis (hydride Roxyethyl) cyclohexane, 2,7-norbornanediol, tetrahydrofuran dimethanol, 2,5-bis (hydroxymethyl) -1,4-dioxane and other diols having an alicyclic structure having 6 to 12 carbon atoms. it can. Furthermore, low molecular weight polyhydric alcohols such as trimethylolpropane, pentaerythritol and sorbitol may be used as the low molecular weight diol.

  The low molecular weight dithiol is not particularly limited as long as the number average molecular weight is 60 or more and less than 400. For example, 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,4- Butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,12-dodecane Dithiol, 2,2-dimethyl-1,3-propanedithiol, 3-methyl-1,5-pentanedithiol, 2-methyl-1,8-octanedithiol, 1,4-cyclohexanedithiol, 1,4-bis ( Mercaptomethyl) cyclohexane, bis (2-mercaptoethyl) ether, bis (2-mercaptoe) L) sulfide, bis (2-mercaptoethyl) disulfide, 2,5-bis (mercaptomethyl) -1,4-dioxane, 2,5-bis (mercaptomethyl) -1,4-dithiane, 2,5-bis (Mercaptoethylthio) -1,4-dithiane, 1,1,1-tris (mercaptomethyl) ethane, 2-ethyl-2-mercaptomethyl-1,3-propanedithiol, tetrakis (mercaptomethyl) methane, 3, Fats such as 3′-thiobis (propane-1,2-dithiol), 2,2′-thiobis (propane-1,3-dithiol), pentaerythritol tetrakis (mercaptopropionate), pentaerythritol tetrakis (mercaptoacetate) Group polythiol, 1,2-benzenedithiol, 1,3-benzenedithiol 1,4-benzenedithiol, 1,3,5-benzenetrithiol, 1,2-bis (mercaptomethyl) benzene, 1,3-bis (mercaptomethyl) benzene, 1,4-bis (mercaptomethyl) benzene, Aromatic polythiols such as 1,3,5-tris (mercaptomethyl) benzene and toluene-3,4-dithiol are listed.

<(D) Polyisocyanate or / and polyisothiocyanate>
(D) Polyisocyanate or / and polyisothiocyanate is not particularly limited, but aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisothiocyanate, aliphatic polyisothiocyanate, alicyclic Examples include polyisothiocyanate and sulfur-containing heterocyclic polyisothiocyanate.

  Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, xylylene diisocyanate (XDI), 4 , 4'-diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl -4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4 ', 4' '-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonylisocyanate Doors and the like.

  Examples of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, etc. Can be mentioned.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, hydrogenated xylylene diisocyanate (hydrogenated XDI), methylcyclohexylene diisocyanate ( Hydrogenated TDI), bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate and the like.

  Examples of the aromatic polyisothiocyanate include tolylene diisothiocyanate, 4,4-diphenylmethane diisothiocyanate, diphenyl disulfide-4,4-diisothiocyanate, and the like.

  Examples of the aliphatic polyisothiocyanate include hexamethylene diisothiocyanate, lysine diisothiocyanate methyl ester, lysine triisothiocyanate, m-xylylene diisothiocyanate, bis (isothiocyanatomethyl) sulfide, bis (isothiocyanatoethyl). ) Sulfide, bis (isothiocyanatoethyl) disulfide and the like.

  Examples of the alicyclic polyisothiocyanate include isophorone diisothiocyanate, bis (isothiocyanatomethyl) cyclohexane, dicyclohexylmethane diisothiocyanate, cyclohexane diisothiocyanate, methylcyclohexane diisothiocyanate, and 2,5-bis (isothiocyanate). Tomethyl) bicyclo- [2.2.1] -heptane, 2,6-bis (isothiocyanatomethyl) bicyclo- [2.2.1] -heptane, 3,8-bis (isothiocyanatomethyl) tri Cyclodecane, 3,9-bis (isothiocyanatomethyl) tricyclodecane, 4,8-bis (isothiocyanatomethyl) tricyclodecane, 4,9-bis (isothiocyanatomethyl) tricyclodecane, etc. It is done.

  Examples of the sulfur-containing heterocyclic polyisothiocyanate include 2,5-diisothiocyanatothiophene, 2,5-bis (isothiocyanatomethyl) thiophene, 2,5-isothiocyanatotetrahydrothiophene, and 2,5-bis. (Isothiocyanatomethyl) tetrahydrothiophene, 3,4-bis (isothiocyanatomethyl) tetrahydrothiophene, 2,5-diisothiocyanato-1,4-dithiane, 2,5-bis (isothiocyanatomethyl)- Examples include 1,4-dithiane, 4,5-diisothiocyanato-1,3-dithiolane, 4,5-bis (isothiocyanatomethyl) -1,3-dithiolane, and the like.

(D) One type of polyisocyanate or / and polyisothiocyanate may be used, or a plurality of types may be used in combination.
(D) The number of isocyanato groups and isothiocyanate groups per molecule of polyisocyanate or / and polyisothiocyanate (hereinafter sometimes referred to as “iso (thio) cyanato group”) is usually two, but according to the present invention (A) Polyisocyanate and / or polyisothiocyanate having 3 or more iso (thio) cyanato groups such as triphenylmethane triisocyanate as long as polythiourethane poly (meth) acrylate does not gel. Can be used.
(D) Among polyisocyanates and / or polyisothiocyanates, (a) polythiocarbonate polythiols, and (b) acidic groups-containing polyols and / or acidic groups-containing polythiols, from the viewpoint of reactivity, primary iso (thio Preference is given to (d) polyisocyanates and / or polyisothiocyanates having a cyanato group.

  In addition, (d) polyisocyanate and / or polyisothiocyanate is (d) polyisocyanate having an alicyclic structure from the viewpoint of obtaining (A) polythiourethane poly (meth) acrylate having high hardness and solvent resistance. Or / and polyisothiocyanate is preferred. Examples of (d) polyisocyanate or / and polyisothiocyanate having an alicyclic structure include, for example, isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), isophorone diisothiocyanate, hydrogenated xylylene diisothiocyanate, etc. Is mentioned.

<(E) Hydroxyl group-containing (meth) acrylate>
(E) A hydroxyl group-containing (meth) acrylate has a hydroxyl group as a functional group that can be bonded to (A) polythiourethane poly (meth) acrylate, and (C) a radical generated by a photopolymerization initiator. It is a compound having a (meth) acryloyl group as an unsaturated group to be polymerized. In the present specification, the (meth) acryloyl group means an acryloyl group and / or a methacryloyl group, and the (meth) acrylate means an acrylate or / and a methacrylate.

  (E) Examples of the hydroxyl group-containing (meth) acrylate include (e′-1) (meth) acrylate having one hydroxyl group and one (meth) acryloyl group in one molecule, (e′-2) (Meth) acrylate having one hydroxyl group and two or more (meth) acryloyl groups in one molecule, (e'-3) two or more hydroxyl groups and one (meth) acryloyl group in one molecule Examples thereof include (meth) acrylate having (meth) acrylate having (e′-4) two or more hydroxyl groups and two or more (meth) acryloyl groups in one molecule. (E) As the hydroxyl group-containing (meth) acrylate, a commercially available product may be used as it is. One type of these compounds may be used, or a plurality of types may be used in combination.

  (E′-1) Examples of (meth) acrylate having one hydroxyl group and one (meth) acryloyl group in one molecule include 2-hydroxyethyl (meth) acrylate and 3-hydroxypropyl (meth). An acrylate etc. are mentioned.

  (E′-2) Examples of (meth) acrylate having one hydroxyl group and two or more (meth) acryloyl groups in one molecule include glycerin di (meth) acrylate, diglycerin tri (meth) acrylate, Examples include trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and sorbitol penta (meth) acrylate.

  (E′-3) Examples of (meth) acrylate having two or more hydroxyl groups and one (meth) acryloyl group in one molecule include glycerin mono (meth) acrylate, diglycerin mono (meth) acrylate, Examples include trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, dipentaerythritol mono (meth) acrylate, and sorbitol mono (meth) acrylate.

  (E′-4) Examples of (meth) acrylate having two or more hydroxyl groups and two or more (meth) acryloyl groups in one molecule include diglycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, Dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, sorbitol di (meth) acrylate, sorbitol tri (meth) acrylate, sorbitol tetra (meth) acrylate, diglycidyl Examples include (meth) acrylic acid adducts of ether compounds. Examples of the (meth) acrylic acid adduct of the diglycidyl ether compound include a (meth) acrylic acid adduct of bisphenol A glycidyl ether.

((A) polythiourethane poly (meth) acrylate)
In the present invention, (A) polythiourethane poly (meth) acrylate comprises (a) polythiocarbonate polythiol, (b) acidic group-containing polyol or / and acidic group-containing polythiol, (d) polyisocyanate or / and It is obtained by reacting a polyisothiocyanate, (e) a hydroxyl group-containing (meth) acrylate, and, if necessary, a polyol or / and polythiol other than (c) (a) and (b).

  In the case of obtaining (A) polythiourethane poly (meth) acrylate, when the total amount of (a) polythiocarbonate polythiol and (b) acidic group-containing polyol or / and acidic group-containing polythiol is 100 parts by mass, The proportion of (a) is preferably 60 to 95 parts by mass, more preferably 65 to 90 parts by mass, particularly preferably 75 to 90 parts by mass, and the proportion of (b) is preferably 5 to 40 parts by mass, more preferably. Is 10 to 35 parts by mass, particularly preferably 10 to 25 parts by mass. When the proportion of (a) is 60 parts by mass or more, the hardness of the coating film tends to be high, and when it is 95 parts by mass or less, the film forming property tends to be improved. When the proportion of (b) is 5 parts by mass or more, the developability with a dilute alkali developer tends to be improved, and when it is 40 parts by mass or less, the water resistance tends to improve.

  In the case of obtaining (A) polythiourethane poly (meth) acrylate, when the total amount of (a) polythiocarbonate polythiol and (b) acidic group-containing polyol or / and acidic group-containing polythiol is 100 parts by mass, (E) The ratio of the hydroxyl group-containing (meth) acrylate is preferably 1 to 40 parts by mass, more preferably 5 to 30 parts by mass, and particularly preferably 10 to 30 parts by mass. Within this range, the reaction time of (e) and the iso (thio) cyanato group can be easily set within an appropriate time, and the hardness of the coating film after irradiation with actinic rays (for example, ultraviolet rays) can be easily set within an appropriate range. It becomes.

  In the case of obtaining (A) polythiourethane poly (meth) acrylate, when the total amount of (a) polythiocarbonate polythiol and (b) acidic group-containing polyol or / and acidic group-containing polythiol is 100 parts by mass, (C) The ratio of polyol or / and polythiol other than (a) and (b) is preferably 0 to 30 parts by mass, more preferably 0 to 10 parts by mass, and particularly preferably 0 to 5 parts by mass. If it is this range, when an optical waveguide is formed, a refractive index and mechanical strength can be made into an appropriate range.

  In the case of obtaining (A) polythiourethane poly (meth) acrylate, (a) polythiocarbonate polythiol, (b) acidic group-containing polyol or / and acidic group-containing polythiol, and (e) hydroxyl group-containing (meth) acrylate. And (d) polyisocyanate or / and polyisothiocyanate iso ((d) with respect to the total number of moles of hydroxyl groups and mercapto groups comprising (c) polyols and / or polythiols other than (a) and (b) as necessary. The ratio of the number of moles of thio) cyanato groups is preferably 1.01 to 2.5. When the ratio of the number of moles is 1.01 or more, (a), (b), (e), and if necessary, the remaining hydroxyl groups and mercapto groups in the compound (c) are reduced, There is a tendency for solvent resistance to improve. When the molar ratio is 2.5 or less, unreacted iso (thio) cyanato groups are less likely to remain, the pot life is likely to be improved, and the coating film obtained by coating is less likely to be uneven. (D) Number of moles of iso (thio) cyanato group of polyisocyanate or / and polyisothiocyanate with respect to the total number of moles of hydroxyl group and mercapto group in the compounds of (a), (b), (c), (e) The ratio is preferably 1.2 to 2.2, particularly preferably 1.2 to 2.0.

  In the case of obtaining (A) polythiourethane poly (meth) acrylate, (a) polythiocarbonate polythiol, (b) acidic group-containing polyol or / and acidic group-containing polythiol, and (e) hydroxyl group-containing (meth) acrylate. If necessary, the reaction order of the polyol or / and polythiol other than (c) (a) and (b) and (d) polyisocyanate or / and polyisothiocyanate is not particularly limited. (A), (b), (c), and (e) may be reacted with (d) in any order, and any of plural types of (a), (b), (c), and (e) The mixture may be reacted with (d) and the remaining compound may be added subsequently to react. When (a), (b), (c), and (e) are blended in plural types, any mixture of plural types among (a), (b), (c), and (e) is (d) ), And the remaining compound may be added and reacted thereafter. Moreover, when (d) is compounded in plural kinds, the order of addition of each (d) may be the same or different.

  (A) In obtaining polythiourethane poly (meth) acrylate, a catalyst can also be used. The catalyst is not particularly limited. For example, salts of metals and organic and inorganic acids such as tin catalysts (trimethyltin laurate, dibutyltin dilaurate, etc.) and lead catalysts (lead octylate, etc.), and organometallic derivatives , Amine catalysts (triethylamine, N-ethylmorpholine, triethylenediamine, etc.), diazabicycloundecene catalysts, and the like. Among them, dibutyltin dilaurate is preferable from the viewpoint of reactivity.

  (A) The acid value of polythiourethane poly (meth) acrylate is 20-200 mgKOH / g. When the acid value is within this range, good dilute alkali developability and water resistance of the coating film can be secured. When the acid value is less than 20 mgKOH / g, development with a dilute alkali developer cannot be performed, and when it is greater than 200 mgKOH / g, the water resistance decreases. The acid value of (A) polythiourethane poly (meth) acrylate is preferably 20 to 100 mgKOH / g, and particularly preferably 25 to 60 mgKOH / g. In this specification, the acid value is measured in accordance with JIS K1557-5.

  As the temperature when (a), (b), (e), and if necessary, the polyol or / and polythiol comprising (c) and (d) the polyisocyanate or / and polyisothiocyanate are reacted, Although it does not restrict | limit, 40-150 degreeC is preferable and 80-120 degreeC is more preferable. When the reaction temperature is 40 ° C. or higher, the raw material is easily dissolved, and the viscosity of the obtained (A) polythiourethane poly (meth) acrylate can be sufficiently stirred without being too high. When the reaction temperature is 150 ° C. or lower, problems such as side reactions are unlikely to occur.

  (A), (b), (e), and if necessary, the reaction of the polyol or / and polythiol comprising (c) with (d) polyisocyanate or / and polyisothiocyanate may be an organic solvent or no solvent. In addition, it may be performed. Examples of the organic solvent include ethers, esters and ketones. Examples thereof include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethylene glycol dimethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylacetamide, tetrahydrofuran, ethyl acetate, and ethyl lactate. The addition amount of the organic solvent is (a), (b), (e), if necessary, on a mass basis with respect to the total amount of (c), preferably 0.1 to 2.0 times, more preferably. Is 0.15 to 0.7 times.

((C) Photopolymerization initiator)
The core-forming resin composition contains (C) a photopolymerization initiator. (C) The photopolymerization initiator functions to form a cured product by polymerizing unsaturated groups such as (meth) acryloyl groups contained in the core-forming resin composition with radicals generated by light irradiation.
(C) Examples of commercially available photopolymerization initiators include Irgacure 184, 369, 379, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur 1116, 1173, Lucirin TPO, LR8883, LR8970 (above, manufactured by BASF) and the like. One type of photopolymerization initiator may be used, or a plurality of types may be used in combination.

((B) (Meth) acrylate having a molecular weight of less than 1000 having one or more (meth) acryloyl groups in the molecule)
The core-forming resin composition has a molecular weight of 1000 having (B) one or more (meth) acryloyl groups in the molecule as components other than (A) polythiourethane poly (meth) acrylate and (C) photopolymerization initiator. Less than (meth) acrylate can be included. (B) (Meth) acrylate having a molecular weight of less than 1000 and having one or more (meth) acryloyl groups in the molecule is a compound containing an unsaturated group that is polymerized by a radical or the like generated by (C) a photopolymerization initiator. .

Examples of the monofunctional monomer containing a (meth) acryloyl group include acryloylmorpholine, dimethylacrylamide, diethylacrylamide, diisopropylacrylamide, isobornyl (meth) acrylate, dicyclopentenyl acrylate, dicyclopentanyl (meth) acrylate, and isodecyl ( (Meth) acrylate, lauryl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, tricyclo Decanyl (meth) acrylate, diacetone acrylamide, isobutoxymethyl (meth) acrylamide, 3-hydroxycyclohexyl (meth) a Lilate, ω-carboxy-polycaprolactone monoacrylate, 2-acryloylcyclohexyl succinic acid, phenoxyethyl (meth) acrylate, tribromophenol ethoxy (meth) acrylate, (meth) acrylate of alcohol which is an adduct of phenol ethylene oxide, (Meth) acrylate of alcohol which is an adduct of ethylene oxide of p-cumylphenol, 4- (1-methyl-1-phenylethyl) phenoxyethyl (meth) acrylate, alcohol of adduct of ethylene oxide of nonylphenol (Meth) acrylate, o-phenylphenol glycidyl ether (meth) acrylate, hydroxyethylated o-phenylphenol acrylate, 2-methacryloyloxyethylphthalate Examples include phosphoric acid, 2-methacryloyloxypropylhexahydrophthalic acid, and methoxypolyethylene glycol (meth) acrylate.
Commercially available monofunctional monomers containing a (meth) acryloyl group include ACMO, DMAA (above, manufactured by Kojin Co., Ltd.), FA511A, FA512A, FA513A, FA-512M, FA-512MT, FA-513M (above, Hitachi Chemical Co., Ltd.) ), Aronix M102, M120, M5300 (above, manufactured by Toagosei Co., Ltd.), NK ester A-LEN-10, A-90G, S-1800M, S-1800A, M-90G (above, manufactured by Shin-Nakamura Chemical Co., Ltd.) ) And the like.

Examples of the bifunctional monomer containing two (meth) acryloyl groups include ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di ( (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2,2-bis-4 (2-hydroxy-) 3-acryloyloxypropylphenyl) propane, ethylene oxide-added bisphenol A type di (meth) acrylate, ethylene oxide added tetrabromobisphenol A type di (meth) acrylate, propylene oxide added bisphenol A type di (meth) acrylate Rate, propylene oxide-added tetrabromobisphenol A di (meth) acrylate, bisphenol A epoxy di (meth) acrylate obtained by epoxy ring-opening reaction of bisphenol A diglycidyl ether and (meth) acrylic acid, tetrabromobisphenol A di Tetrabromobisphenol A type epoxy di (meth) acrylate obtained by epoxy ring-opening reaction between glycidyl ether and (meth) acrylic acid, bisphenol F obtained by epoxy ring-opening reaction between bisphenol F diglycidyl ether and (meth) acrylic acid -Type epoxy di (meth) acrylate, tetrabromobisphenol F-type epoxy di (meth) obtained by epoxy ring-opening reaction between tetrabromobisphenol F diglycidyl ether and (meth) acrylic acid Acrylates, 9,9 bis [4- (2- acryloyloxy ethoxy) phenyl] fluorene, and the like. Among them, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 2,2-bis-4 (2-hydroxy-3-acryloyloxypropylphenyl) propane, ethylene oxide Addition bisphenol A type di (meth) acrylate, ethylene oxide addition tetrabromobisphenol A type di (meth) acrylate, bisphenol A type epoxy di (meth) obtained by epoxy ring-opening reaction of bisphenol A diglycidyl ether and (meth) acrylic acid ) Tetrabromobisphenol A type epoxy di (meth) acrylate obtained by epoxy ring-opening reaction of acrylate, tetrabromobisphenol A diglycidyl ether and (meth) acrylic acid, 9,9-bis [4- (2-acryloyloxyate) Xyl) phenyl] fluorene and the like.
As a commercial item of a bifunctional monomer, for example, Aronix M-208, M-215 (above, manufactured by Toagosei Co., Ltd.), NK ester A-BPE-4, A-BPEF, APG-200 (above, Shin-Nakamura Chemical Co., Ltd.) Manufactured), FA-124AS, FA-240A, FA-321A, FA-324A (manufactured by Hitachi Chemical Co., Ltd.) and the like.

  Examples of the tri- or higher functional monomer include a reaction product of isocyanurate obtained from 3 molecules of hexamethylene diisocyanate and 3 molecules of 2-hydroxyethyl (meth) acrylate, and isocyanurate obtained from 3 molecules of hexamethylene diisocyanate. And a reaction product of 3 molecules of 2-hydroxyethyl (meth) acrylate with a caprolactone adduct, trimethylolpropane tri (meth) acrylate, ethylene oxide (hereinafter referred to as “EO”) modified trimethylolpropane tri (meth) acrylate, Propylene oxide (hereinafter referred to as “PO”) modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, 2,2,2 Tris (meth) acryloyloxymethylethylphthalic acid, 2,2,2-tris (meth) acryloyloxymethylethylsuccinic acid, succinic acid modified pentaerythritol triacrylate, EO modified tris (acryloyloxy) isocyanurate, caprolactone modified tris- (2-acryloyloxyethyl) isocyanurate, tris (acryloyloxy) isocyanurate, pentaerythritol tetra (meth) acrylate, PO-modified pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta ( (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, EO-modified dipentaerythritol hexa (meth) acrylate, PO modified Dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, tri methacryloyloxyethyl phosphate, and the like.

Examples of commercially available trifunctional or higher monomers include Aronix M-315, M-327, M-309 (manufactured by Toagosei Co., Ltd.), NK ester A-TMPT, A-TMMT, A-TMM-3LMN, A-9300 (above, Shin-Nakamura Chemical Co., Ltd. product), FA-137M, FA-731A (above, Hitachi Chemical Co., Ltd.) etc. are mentioned.
Further, polyether acrylic oligomer, polyester acrylic oligomer, polycarbonate acrylic oligomer, or polyepoxy acrylic oligomer having polyether, polyester, and polycarbonate in the main chain can also be used.

  The core molding resin composition preferably contains (B) a (meth) acrylate having a molecular weight of less than 1000 and having one or more (meth) acryloyl groups in the molecule. (B) By containing (meth) acrylate having a molecular weight of less than 1000 and having one or more (meth) acryloyl groups in the molecule, the viscosity of the resin composition for core molding can be reduced, and radical polymerization reaction The reaction rate can be increased. The molecular weight of the component (B) is more preferably 100 to 950, particularly preferably 100 to 700.

As the component (B), either a monofunctional monomer or a polyfunctional monomer containing a (meth) acryloyl group may be used alone, or a plurality of types may be used in combination.
In the core-forming resin composition, the amount of the component (A) is preferably 50 to 90% by mass with respect to the total amount of the components (A) to (B). It is preferable that the compounding quantity of (B) component is 10-50 mass% with respect to the total amount of (A)-(B) component. When the component (A) is 90% by mass or less and the component (B) is 10% by mass or more, the solvent resistance and developer resistance of the cured product are improved, and the transmission loss of the resulting optical waveguide tends to be reduced. is there. When the component (A) is 50% by mass or more and the component (B) is 50% by mass or less, the flexibility of the cured product tends to be improved.

  In the core-forming resin composition, the blending amount of the component (C) is preferably 0.01 to 10 parts by mass, more preferably 0 with respect to 100 parts by mass of the total amount of the components (A) to (B). 0.1 to 10 parts by mass, still more preferably 0.2 to 7 parts by mass, and particularly preferably 0.5 to 5 parts by mass. When the blending amount of component (C) is 0.01 parts by mass or more, curing proceeds sufficiently and it becomes easy to form a cured product (core portion) having sufficient mechanical properties. When the blending amount is 10 parts by mass or less, the photopolymerization initiator is less likely to adversely affect the long-term characteristics of the cured product.

  In the core-forming resin composition, if necessary, photosensitizer, antioxidant, yellowing inhibitor, UV absorber, visible light absorber, colorant, plasticizer, stabilizer, filler, etc. You may add what is called an additive in the range which does not impair the effect of this invention.

  Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Isoamyl etc. are mentioned.

  The core-forming resin composition may be diluted with an organic solvent to form a core-forming resin varnish. The organic solvent used here is not particularly limited as long as it can dissolve the resin composition. For example, (A), (b), (e) in (A) polythiourethane poly (meth) acrylate If necessary, the compound added in the reaction of the polyol or / and polythiol comprising (c) and (d) the polyisocyanate or / and polyisothiocyanate can be used. In that case, the amount of the organic solvent is the sum of the amount of the added organic solvent and the amount of the organic solvent added later. One type of these organic solvents may be used, or a plurality of types may be used in combination. Moreover, it is preferable that the solid content density | concentration in a resin varnish is 2-80 mass% normally.

  When preparing the resin composition for core formation, it is preferable to mix by stirring. Although there is no restriction | limiting in particular in the stirring method, The stirring using a propeller is preferable from a viewpoint of stirring efficiency. The order of addition of each component is not particularly limited, and after sufficiently mixing two arbitrary components, the third and subsequent components may be added and mixed, or all the components may be mixed simultaneously.

[Optical waveguide]
The optical waveguide according to the present invention will be described below.
FIG. 1 shows a cross-sectional view of an example of an optical waveguide. The optical waveguide 1 is formed on a base material 5 and includes a core portion 2 that is a cured product of a core-forming resin composition having a high refractive index, and a lower cladding layer made of a resin composition for forming a cladding layer having a low refractive index. 4 and the upper clad layer 3. The core-forming resin composition of the present invention can be used for the core portion 2 of the optical waveguide 1.

  There is no restriction | limiting in particular as a material of the base material 5, For example, a glass epoxy resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, a polyimide substrate, a metal substrate etc. are mentioned.

  The lower clad layer and the upper clad layer are determined so that the refractive index relationship of each part including the core part satisfies the conditions required for the optical waveguide. Specifically, a material having a lower refractive index than that of the core portion is used for the lower cladding layer and the upper cladding layer. The material of each clad layer is not particularly limited, but the same photo-curable resin composition is preferable in terms of economy and production management. Examples of the photocurable resin composition include a resin composition containing polyurethane (meth) acrylate and a photopolymerization initiator, and a photopolymerizable compound having an unsaturated bond such as (meth) acrylate in the composition. Examples thereof include a resin composition.

  The thickness of the lower clad layer 4 and the upper clad layer 3 is not particularly limited, but is, for example, 2 to 200 μm. When the thickness is 2 μm or more, propagating light can be confined in the core. Moreover, although the thickness of the core part 2 is not specifically limited, For example, it is 1-100 micrometers.

[Optical Waveguide Manufacturing Method]
Hereafter, the manufacturing method for forming the optical waveguide using the resin composition for core formation of this invention is demonstrated.
There is no restriction | limiting in particular as a method to manufacture the optical waveguide which concerns on this invention, For example, the method of forming and forming the resin layer for core formation on a base material using the resin composition for core formation is mentioned.

The method for forming the core-forming resin layer is not particularly limited. For example, using the core-forming resin composition, spin coating, dip coating, spraying, bar coating, roll coating, curtain coating Examples thereof include coating methods such as a method, a gravure coating method, a screen coating method, an ink jet coating method, and an immersion method.
When the core-forming resin composition is diluted with the organic solvent to form a core-forming resin varnish, a drying step may be added after forming a resin layer as necessary. The drying method is not particularly limited.
As another method for forming the core-forming resin layer, there is a laminating method using a core-forming resin film using the core-forming resin composition.

  Hereinafter, although the manufacturing method of the optical waveguide 1 by the resin varnish for core formation is demonstrated, this invention is not restrict | limited at all to this.

(1) Step of forming lower clad layer A lower clad composition is applied to the upper surface of the substrate 5 and dried or prebaked to form a lower clad thin film. The lower cladding thin film is cured by irradiating light to form a lower cladding layer 4 that is a cured body. You may add post-baking after irradiating light. Examples of the lower cladding composition include the above-described photo-curable resin composition.

(2) Core Part Formation Step A core forming resin composition is applied to the upper surface of the lower cladding layer 4 and dried or prebaked to form a core thin film.
Thereafter, the core portion 2 is exposed. There is no restriction | limiting in particular as a method of exposing the core part 2, For example, the method of exposing through a negative photomask and the method of irradiating an active ray directly to a core part using a laser direct description are mentioned.
Although it does not restrict | limit especially as a light source of actinic light, What emits light with a wavelength of 200-450 nm can be used, For example, a super high pressure mercury lamp, a high pressure mercury lamp, a mercury vapor arc lamp, a metal halide lamp, a xenon lamp, Carbon arc lamps, LEDs, and the like can be used.
The development process exposes the pattern according to a predetermined pattern, and utilizes the difference in solubility between the cured portion and the uncured portion for the selectively cured thin film, and only the uncured portion using the developer. Is to be removed.

The development method is not particularly limited, and examples thereof include a spray method, a dip method, a paddle method, a spin method, a brushing method, and a scraping method. You may use these image development methods together as needed.
As the developer used for the development treatment, an organic solvent which is an organic base and an alkaline aqueous solution can be used. In consideration of the treatment of the waste liquid and the influence on the environment, it is preferable to use a dilute alkaline aqueous solution. When the core-forming resin composition of the present invention is used as the core composition, development processing can be performed with a dilute aqueous alkali solution. Examples of the alkali compound for preparing the diluted alkaline aqueous solution include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, and other inorganic bases, ethylamine, n-propylamine, diethylamine, di-n. -Propylamine, triethylamine, methyldiethylamine, N-methylpyrrolidone, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo [5. And organic bases such as 4.0] -7-undecene and 1,5-diazabicyclo [4.3.0] -5-nonane.
These alkali compounds may be used alone or in combination of two or more. The pH of the alkaline aqueous solution is preferably 9 to 14, more preferably 10 to 14, and particularly preferably 11 to 14. Moreover, you may mix and use surfactant, an antifoamer, etc. in alkaline aqueous solution.

  As the processing after development, washing may be performed using an organic solvent, water, a mixed solution of an organic solvent and water, or the like as necessary.

  After pattern formation, the patterning portion may be heat-treated (post-baked). Although this heating condition changes with component composition etc. of the resin composition for core formation, what is necessary is just to carry out at 50 to 200 degreeC normally.

(3) Forming process of the upper cladding layer In this process, the upper cladding layer 3 is formed on the upper surfaces of the core portion 2 and the lower cladding layer 4. The upper clad composition is applied to the upper surfaces of the core portion 2 and the lower clad layer 4, dried or prebaked to form an upper clad thin film, and the upper clad thin film is irradiated with light and cured. The upper clad layer 3 as a body is formed. After light irradiation, heat treatment (post-bake) may be performed. Examples of the upper clad composition include the above-described photocurable resin composition.

  Next, the present invention will be described in more detail with reference to examples and comparative examples.

Physical properties of polythiocarbonate polythiol Mercapto group value (SH value; mgKOH / g):
Weigh the sample in a 100 mL (milliliter) sample bottle (mass is accurately read to the fourth decimal place in grams), 5 mL acetic anhydride-tetrahydrofuran solution (containing 4 g acetic anhydride in 100 mL solution) and 4-dimethylaminopyridine -Add exactly 10 mL of tetrahydrofuran solution (containing 1 g of 4-dimethylaminopyridine in 100 mL of solution) to completely dissolve the sample, then leave it at room temperature for 1 hour, then add exactly 1 mL of ultrapure water. After stirring at room temperature for 30 minutes, titration was performed with a 0.5 M potassium hydroxide-ethanol solution (indicator: phenolphthalein). The SH value was calculated by the following formula.

SH value (mgKOH / g) = 28.05 × (BA) / S
(In the formula, S is the amount of sample collected (g), A is the amount of 0.5M potassium hydroxide-ethanol solution (mL) required for the titration of the sample, and B is 0.5M hydroxide required for the blank test. (Represents the amount (mL) of potassium-ethanol solution.)

2. Number average molecular weight (Mn):
The polythiocarbonate polythiol used in Examples and Comparative Examples is polythiocarbonate dithiol and has a valence of 2. The number average molecular weight was calculated by the following formula.
Mn = 112200 / SH value

3. Acid value (mgKOH / g):
The sample was dissolved in 200 mL of a toluene-ethanol solution (equal volume mixed solution) and titrated with a 0.1 M potassium hydroxide-ethanol solution (indicator: phenolphthalein). The acid value was calculated by the following formula.

Acid value (mgKOH / g) = 5.61 (TU) f ′ / S ′
(In the formula, S ′ is the amount of sample collected (g), T is the amount of 0.1 M potassium hydroxide-ethanol solution required for titration of the sample (mL), and U is 0.1 M water required for the blank test. (Amount of potassium oxide-ethanol solution (mL), f ′ represents a factor of 0.1M potassium hydroxide-ethanol solution)

Production of polythiocarbonate polythiol [Production Example 1]
90.1 g (0.599 mol) of 1,6-hexanedithiol was placed in a 500 mL glass reactor equipped with a stirrer, thermometer and distillation column (equipped with a fractionation tube, reflux head and condenser at the top of the column). ), 77.2 g (0.500 mol) of bis (2-mercaptoethyl) sulfide, 155 g (0.725 mol) of diphenyl carbonate, and 0.861 g (0.332 mmol) of a 10% by mass tetrabutylammonium hydroxide-methanol solution. ) And maintained at 200 mmHg (27 kPa) and 160 ° C. for 2 hours while refluxing. Next, while the phenol was distilled off, the pressure was gradually reduced to 50 mmHg (6.7 kPa) over 8 hours, and when the phenol stopped distilling, the pressure was increased from 30 mmHg (4.0 kPa) to 15 mmHg (2.0 kPa). The pressure was gradually reduced over time, and the mixture was further reacted while distilling a mixture of bis (2-mercaptoethyl) sulfide, 1,6-hexanedithiol and phenol to obtain the desired polythiocarbonate polythiol. Mercapto group value of polythiocarbonate polythiol of Production Example 1 (using 1,6-hexanedithiol (HDT), bis (2-mercaptoethyl) sulfide (MES) and diphenyl carbonate as raw materials): 208.6 mgKOH / g, number Average molecular weight (Mn): 537, HDT / MES = 57/43 (molar ratio). The molar ratio is a value calculated from the NMR peak area ratio.

[Production Example 2]
To a glass reactor having an internal volume of 500 mL equipped with a stirrer, a thermometer, and a distillation column (equipped with a fractionation tube, a reflux head, and a condenser at the top of the column), 103.9 g (0.691 mol) of 1,6-hexanedithiol. ), 89.3 g (0.578 mol) of bis (2-mercaptoethyl) sulfide, 217.5 g (1.02 mol) of diphenyl carbonate, and 1.03 g (0.003 mol) of a 10 mass% tetrabutylammonium hydroxide-methanol solution. 40 mmol), and was held at 200 mmHg (27 kPa) and 160 ° C. for 2 hours while refluxing. Next, while the phenol was distilled off, the pressure was gradually reduced to 50 mmHg (6.7 kPa) over 8 hours, and when the phenol stopped distilling, the pressure was increased from 30 mmHg (4.0 kPa) to 15 mmHg (2.0 kPa). The pressure was gradually reduced over time, and the mixture was further reacted while distilling a mixture of bis (2-mercaptoethyl) sulfide, 1,6-hexanedithiol and phenol to obtain the desired polythiocarbonate polythiol. Mercapto group value of polythiocarbonate polythiol of Production Example 2 (using 1,6-hexanedithiol (HDT), bis (2-mercaptoethyl) sulfide (MES) and diphenyl carbonate as raw materials): 137.0 mg KOH / g, number Average molecular weight (Mn): 819, HDT / MES = 58/42 (molar ratio). The molar ratio is a value calculated from the NMR peak area ratio.

[Production Example 3]
2,5-bis (mercaptoethylthio) -1,4 was added to a 500 mL glass reactor equipped with a stirrer, thermometer, distillation column (with a fractionation tube, reflux head, and condenser at the top of the column). -Dithiane 40.3 g (0.132 mol), 1,6-hexanedithiol 80.0 g (0.532 mol), bis (2-mercaptoethyl) sulfide 81.7 g (0.529 mol), diphenyl carbonate 150 g ( 0.699 mol) and 0.964 g (0.371 mmol) of a 10% by mass tetrabutylammonium hydroxide-methanol solution were charged and maintained at 200 mmHg (27 kPa) and 160 ° C. for 1 hour while refluxing. Subsequently, the pressure was gradually reduced to 50 mmHg (6.7 kPa) over 8 hours while distilling off the phenol, and when the phenol stopped distilling, the pressure was increased from 30 mmHg (4.0 kP) to 15 mmHg (2.0 kPa) for 3 hours. The polythiocarbonate polythiol was produced by further reaction while distilling phenol. To this polythiocarbonate polythiol, equimolar amount of p-toluenesulfonic acid monohydrate is added to the above catalyst and stirred at 100 mmHg (13 kPa) at 130 ° C. for 2 hours to inactivate the catalyst to obtain the desired polythiocarbonate polythiol. Got. Polythiocarbonate polythiol (2,5-bis (mercaptoethylthio) -1,4-dithiane, 1,6-hexanedithiol (HDT), bis (2-mercaptoethyl) sulfide (MES), and diphenyl of Production Example 3 Mercapto group value of carbonate as a raw material): 212.3 mg KOH / g, number average molecular weight (Mn): 529, 2,5-bis (mercaptoethylthio) -1,4-dithiane / HDT / MES = 12/41 / 47 (molar ratio). The molar ratio is a value calculated from the NMR peak area ratio.

(A) Production of polythiourethane polyacrylate (polythiourethane polyacrylate A1 for core)
In a reactor equipped with a stirrer and a heater, 34.1 g (0.0635 mol) of polythiocarbonate polythiol described in Production Example 1 and 112.7 g of propylene glycol monomethyl ether acetate were charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 59.0 g (0.265 mol) of isophorone diisocyanate (IPDI) and 0.05 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 1 hour. Next, 3.11 g (0.0254 mol) of 1,4-butanedithiol and 15.0 g (0.112 mol) of dimethylolpropionic acid were added and reacted at 100 ° C. for 8 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Next, 0.04 g of methoquinone, 0.04 g of dibutylhydroxytoluene (BHT), 39.6 g (0.133 mol) of pentaerythritol triacrylate (manufactured by Daicel Cytec Co., Ltd., trade name: PETRA) were added and reacted for 5 hours. A polythiourethane polyacrylate A1 solution was obtained.

(Polythiourethane polyacrylate A2 for core)
In a reactor equipped with a stirrer and a heater, 29.90 g (0.0557 mol) of polythiocarbonate polythiol described in Production Example 1 and 70.8 g of propylene glycol monomethyl ether acetate were charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 28.77 g (0.129 mol) of isophorone diisocyanate (IPDI) and 0.04 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 3 hours. Next, 5.39 g (0.0382 mol) of dimethylolpropionic acid was added and reacted at 100 ° C. for 8 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Next, 0.03 g of methoquinone, 0.03 g of dibutylhydroxytoluene (BHT), 22.8 g (0.0764 mol) of pentaerythritol triacrylate (manufactured by Daicel Cytec Co., Ltd., trade name: PETRA) were added and reacted for 5 hours. A core polythiourethane polyacrylate A2 solution was obtained.

(Polythiourethane polyacrylate A3 for core)
A reaction apparatus equipped with a stirrer and a heater was charged with 25.4 g (0.0310 mol) of polythiocarbonate polythiol described in Production Example 2 and 38.1 g of propylene glycol monomethyl ether acetate while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 18.9 g (0.0852 mol) of isophorone diisocyanate (IPDI) and 0.02 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 3 hours. Next, 4.21 g (0.0314 mol) of dimethylolpropionic acid was added and reacted at 100 ° C. for 8 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Next, 0.05 g of methoquinone, 0.04 g of dibutylhydroxytoluene (BHT) and 13.8 g (0.0463 mol) of pentaerythritol triacrylate (manufactured by Daicel Cytec Co., Ltd., trade name PETRA) were added and reacted for 5 hours. A polythiourethane polyacrylate A3 solution was obtained.

(Polythiourethane polyacrylate A4 for core)
In a reactor equipped with a stirrer and a heater, 20.1 g (0.0245 mol) of polythiocarbonate polythiol described in Production Example 2 and 32.5 g of propylene glycol monomethyl ether acetate were charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 22.0 g (0.0992 mol) of isophorone diisocyanate (IPDI) and 0.02 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 3 hours. Next, 6.89 g (0.0514 mol) of dimethylolpropionic acid was added and reacted at 100 ° C. for 8 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Next, methoquinone 0.06 g, dibutylhydroxytoluene (BHT) 0.05 g, pentaerythritol triacrylate (manufactured by Daicel Cytec Co., Ltd., trade name PETRA) 15.8 g (0.0530 mol), propylene glycol monomethyl ether acetate 11. 5 g was added and allowed to react for 5 hours. Finally, 10.0 g of ethyl lactate was added and stirred to obtain a polythiourethane polyacrylate A4 solution for the core.

(Polythiourethane polyacrylate A5 for core)
In a reactor equipped with a stirrer and a heater, 33.0 g (0.0403 mol) of polythiocarbonate polythiol described in Production Example 2, 1.64 g (0.0134 mol) of 1,4-butanedithiol, propylene glycol monomethyl 51.4 g of ether acetate was charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 35.03 g (0.1803 mol) of hydrogenated xylylene diisocyanate (H ₆ XDI) and 0.04 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 3 hours. Next, 10.9 g (0.0811 mol) of dimethylolpropionic acid was added and reacted at 95 ° C. for 3 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Subsequently, 0.03 g of methoquinone, 0.03 g of dibutylhydroxytoluene (BHT), 24.9 g (0.0835 mol) of pentaerythritol triacrylate (manufactured by Daicel Cytec Co., Ltd., trade name: PETRA) were added and reacted for 3 hours. . Finally, 19.3 g of propylene glycol monomethyl ether was added and stirred to obtain a polythiourethane polyacrylate A5 solution for the core.

(Core polythiourethane polyacrylate A6)
In a reaction apparatus equipped with a stirrer and a heater, 26.2 g (0.0496 mol) of polythiocarbonate polythiol described in Production Example 3 and 69.9 g of propylene glycol monomethyl ether acetate were charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 38.7 g (0.200 mol) of hydrogenated xylylene diisocyanate (H6XDI) and 0.03 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 3 hours. Next, 13.6 g (0.101 mol) of dimethylolpropionic acid was added and reacted at 95 ° C. for 4 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Next, 0.02 g of methoquinone, 0.02 g of dibutylhydroxytoluene (BHT), 29.7 g (0.0996 mol) of pentaerythritol triacrylate (manufactured by Daicel Cytec Co., Ltd., trade name: PETRA) were added and reacted for 3 hours. A core polythiourethane polyacrylate A6 solution was obtained.

(Polythiourethane polyacrylate A7 for core)
A reaction apparatus equipped with a stirrer and a heater was charged with 49.3 g (0.0919 mol) of polythiocarbonate polythiol described in Production Example 1 and 29.1 g of dimethylacetamide (DMAC) while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 41.1 g (0.185 mol) of isophorone diisocyanate (IPDI) and 0.05 g of dibutyltin dilaurate as a catalyst were added and stirred at 100 ° C. for 2 hours. Next, 2.64 g (0.0216 mol) of 1,4-butanedithiol and 3.83 g (0.0286 mol) of dimethylolpropionic acid were added and reacted at 100 ° C. for 5 hours. Next, the temperature of the reaction solution was set to 80 ° C., air was introduced, and an air atmosphere was established. Subsequently, 0.03 g of methoquinone, 0.05 g of dibutylhydroxytoluene (BHT) and 13.3 g (0.102 mol) of hydroxyethyl methacrylate (HEMA) were added and reacted for 5 hours. Finally, 13.7 g of DMAC was added and stirred to obtain a core polythiourethane polyacrylate A7 solution.

(Poly (meth) acrylate B1 for core)
Synthesized in accordance with JP2011-117988. That is, 43.3 g of propylene glycol monomethyl ether acetate and 14.2 g of ethyl lactate were weighed in a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel and a thermometer, and stirred while introducing nitrogen gas. went. The liquid temperature was raised to 65 ° C., 13.3 g of N-cyclohexylmaleimide, 61.1 g of benzyl methacrylate, 13.5 g of methacrylic acid, 1.3 g of 2,2′-azobis (2,4-dimethylvaleronitrile), propylene glycol A mixture of 44.3 g of monomethyl ether acetate and 14.4 g of ethyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 1 hour, and further stirring at 95 ° C. for 1 hour to obtain a poly (meth) acrylate B1 solution. Obtained.

(Clad polyurethane acrylate D1)
In a reaction apparatus equipped with a stirrer and a heater, polycarbonate diol (trade name PLACEL CD220 PL, manufactured by Daicel Corporation, hydroxyl value 57.1 mgKOH / g, polyol component is 1,6-hexanediol and 3-methyl-1,5 -Polycarbonate diol (pentanediol) 82.8 g (0.0422 mol) and 57.8 g of propylene glycol monomethyl ether acetate were charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 14.6 g (0.0656 mol) of isophorone diisocyanate (IPDI) and 0.04 g of dibutyltin dilaurate as a catalyst were added and stirred at 80 ° C. for 3 hours. Next, air was introduced to create an air atmosphere. Subsequently, 0.03 g of methoquinone, 0.05 g of dibutylhydroxytoluene (BHT) and 3.4 g (0.0293 mol) of hydroxyethyl acrylate were added and reacted for 1 hour to obtain a polyurethane acrylate D1 solution for a clad layer.

(Clad polyurethane acrylate D2)
To a reaction apparatus equipped with a stirrer and a heater, polycarbonate diol (trade name UH-200, manufactured by Ube Industries, hydroxyl value 55.0 mg KOH / g, polycarbonate diol whose polyol component is 1,6-hexanediol) 101. 0 g (0.0495 mol) and 65.8 g of propylene glycol monomethyl ether acetate were charged while introducing nitrogen. Thereafter, the mixture was stirred at 70 ° C. Next, 16.8 g (0.0756 mol) of isophorone diisocyanate (IPDI) and 0.03 g of dibutyltin dilaurate as a catalyst were added and stirred at 80 ° C. for 2 hours. Next, air was introduced to create an air atmosphere. Next, 0.03 g of methoquinone, 0.03 g of dibutylhydroxytoluene (BHT) and 4.27 g (0.0368 mol) of hydroxyethyl acrylate were added and reacted for 1 hour. Finally, 13.7 g of propylene glycol monomethyl ether was added and stirred. A layered polyurethane acrylate D2 solution was obtained.

(Blocked isocyanurate BL01)
In a reactor equipped with a stirrer and a heater, 94.0 g of HDI-modified isocyanurate (trade name Duranate TPA-100, manufactured by Asahi Kasei Co., Ltd., isocyanate group content 23.2 wt%) and 20.8 g of propylene glycol monomethyl ether acetate were added at room temperature. The system was charged while introducing nitrogen. Next, 43.8 g (0.503 mol) of methyl ethyl ketone oxime was slowly added dropwise, then the mixture was heated to 80 ° C. and stirred for 1 hour, 59.4 g of propylene glycol monomethyl ether acetate was added and stirred, and blocked isocyanurate BL01 A solution was obtained.

  In Table 1, the raw material used for manufacture of polythiourethane polyacrylate A1-A7, a compounding ratio, and an acid value are shown. In addition, a compounding ratio is the value calculated so that the sum total of the raw material applicable to ae may become 100.

  Each component was mixed with the compounding quantity (g) shown in Table 2, and the resin composition for core formation of Examples 1-6 was prepared. Polythiourethane polyacrylates A1 to A6 use an organic solvent at the time of synthesis. The upper numerical value in Table 2 is the blending amount (g) including the solvent, and the lower is the solid blending amount (g) excluding the solvent. Represent. Other components represent the blending amount (g) as it is.

  Each component was mixed with the compounding quantity (g) shown in Table 3, and the resin composition for clad layer formation used by the Example and the comparative example was prepared. The polyurethane acrylates D1 and D2 for the cladding layer and the blocked isocyanurate BL01 use an organic solvent at the time of synthesis. The upper value in Table 3 is the blending amount (g) including the solvent, and the lower value is the solid content excluding the solvent. The blending amount (g) is represented. Other components represent the blending amount (g) as it is.

[Example 7]
Using the CPU001 of Example 1 as the core forming resin composition and CL01 as the upper and lower cladding layer forming resin compositions, a film-like optical waveguide was formed according to the following (1) to (3).

(1) Formation of lower clad layer A clad layer forming resin composition is applied to the upper surface of a silicon substrate with a spin coater, and then a UV light is irradiated to the coating film made of the clad layer forming resin composition with a high-pressure mercury lamp. (Integrated light quantity: 2000 mJ / cm ² ) · Photocured to form a lower cladding layer having a thickness of 20 μm.
(2) Formation of core portion The core forming resin composition CPU001 was applied onto the lower clad layer with an applicator, and prebaked at 100 ° C for 30 minutes. Next, an exposure amount of 2000 mJ / cm is applied to a 50 μm-thick coating film made of the core-forming resin composition through a photomask having a line-shaped pattern with a width of 50 μm using a projection exposure machine UFX-2023B manufactured by USHIO INC. ² and photocured. Then, the substrate having the cured coating film was immersed in a developer composed of a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution (pH 13) for 10 minutes, and then rinsed with ultrapure water for 5 minutes. The unexposed portion was dissolved and then rinsed with isopropyl alcohol to form a core portion having a line pattern having a width of 50 μm.
(3) Formation of upper clad layer The clad layer forming resin composition is applied to the upper surface of the lower clad layer having the core portion by an applicator, and then applied to the coating film made of the clad layer forming resin composition. Were irradiated with UV light (integrated light quantity 2000 mJ / cm ² ) and photocured to form an upper clad layer.

[Example 8]
Using the CPU002 of Example 2 as the core forming resin composition and CL02 as the upper and lower cladding layer forming resin compositions, a film-like optical waveguide was formed according to the following (1) to (3).

(1) Formation of lower clad layer A clad layer forming resin composition is applied to the upper surface of a silicon substrate with a spin coater, and then a UV light is irradiated to the coating film made of the clad layer forming resin composition with a high-pressure mercury lamp. (Integrated light quantity: 2000 mJ / cm ² )-Photocured and then post-baked at 140 ° C. for 1 hour to form a lower cladding layer having a thickness of 20 μm.
(2) Formation of core part A core part was formed in the same manner as in Example 7 except that the core-forming resin composition CPU002 was used.
(3) Formation of upper clad layer The clad layer forming resin composition is applied to the upper surface of the lower clad layer having the core portion by an applicator, and then applied to the coating film made of the clad layer forming resin composition. Were irradiated with UV light (integrated light quantity 2000 mJ / cm ² ) and photocured, and then post-baked at 140 ° C. for 1 hour to form an upper clad layer.

[Example 9]
Using the CPU003 of Example 3 as the core forming resin composition and CL02 as the upper and lower cladding layer forming resin compositions, a film-like optical waveguide was formed according to the following (1) to (3).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 8.
(2) Formation of core part The core forming resin composition CPU003 was applied onto the lower clad layer with an applicator and prebaked at 100 ° C for 30 minutes. Next, an exposure amount of 2000 mJ / cm is applied to a 50 μm-thick coating film made of the core-forming resin composition through a photomask having a line-shaped pattern with a width of 50 μm using a projection exposure machine UFX-2023B manufactured by USHIO INC. ² and photocured. And after immersing the board | substrate which has the hardened coating film in the developing solution which consists of 1% sodium carbonate aqueous solution (pH11) for 10 minutes, it rinses for 5 minutes with an ultrapure water, the unexposed part of a coating film is dissolved, width | variety A core portion having a line pattern of 50 μm was formed.
(3) Formation of upper clad layer In the same manner as in Example 8, an upper clad layer was formed.

[Example 10]
Using the CPU004 of Example 4 as the core forming resin composition and CL02 as the upper and lower cladding layer forming resin compositions, a film-like optical waveguide was formed according to the following (1) to (3).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 8.
(2) Formation of core part The core forming resin composition CPU004 was applied onto the lower clad layer with an applicator, and prebaked at 100 ° C for 30 minutes. Next, an exposure amount of 2000 mJ / cm is applied to a 50 μm-thick coating film made of the core-forming resin composition through a photomask having a line-shaped pattern with a width of 50 μm using a projection exposure machine UFX-2023B manufactured by USHIO INC. ² and photocured. And after immersing the board | substrate which has the hardened coating film in the developing solution which consists of 1% sodium carbonate aqueous solution (pH11) for 10 minutes, it rinses for 5 minutes with an ultrapure water, and an unexposed part is removed, and 60 degreeC is 30 minutes. After drying, post-baking was performed at 140 ° C. for 1 hour to form a core portion having a line pattern with a width of 50 μm.
(3) Formation of upper clad layer In the same manner as in Example 8, an upper clad layer was formed.

[Example 11]
Using CPU005 of Example 5 as the core-forming resin composition and CL01 as the upper and lower cladding layer-forming resin compositions, a film-like optical waveguide was formed according to the following (1) to (3).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 7.
(2) Formation of Core Part The core forming resin composition CPU005 was applied on the lower clad layer with an applicator and prebaked at 100 ° C. for 30 minutes. Next, an exposure amount of 300 mJ / cm is applied to a 50 μm thick coating film made of the core forming resin composition through a photomask having a line pattern of 50 μm width using a projection exposure machine UFX-2023B manufactured by USHIO INC. ² and photocured. And after immersing the board | substrate which has the hardened coating film in the developing solution which consists of 1% sodium carbonate aqueous solution (pH11) for 10 minutes, it rinses for 5 minutes with an ultrapure water, and an unexposed part is removed, and 60 degreeC is 30 minutes. After drying, post-baking was performed at 140 ° C. for 1 hour to form a core portion having a line pattern with a width of 50 μm.
(3) Formation of upper clad layer In the same manner as in Example 7, an upper clad layer was formed.

[Example 12]
Using the CPU006 of Example 6 as the core forming resin composition and CL01 as the upper and lower cladding layer forming resin compositions, a film-like optical waveguide was formed according to the following (1) to (3).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 7.
(2) Formation of Core Part A core part having a line-shaped pattern with a width of 50 μm was formed in the same manner as in the procedure of (2) of Example 11 except that the core-forming resin composition CPU006 was used.
(3) Formation of upper clad layer In the same manner as in Example 7, an upper clad layer was formed.

  Each component was mixed with the compounding quantity (g) shown in Table 4, and the resin composition for core formation of Comparative Examples 1-3 was prepared. The core polythiourethane polyacrylate A7, the core poly (meth) acrylate B1 and the blocked isocyanurate BL01 use an organic solvent at the time of synthesis, and the numerical values in the upper part of Table 4 are blending amounts including the solvent (g) The lower part represents the solid content (g) excluding the solvent. Other components represent the blending amount (g) as it is.

[Comparative Example 4]
The CPU007 of Comparative Example 1 was used as the core forming resin composition, and CL01 was used as the upper and lower cladding layer forming resin compositions, and the core portion was provided according to the following (1) and (2).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 7.
(2) Formation of core portion Except for using the core-forming resin composition CPU007, an attempt was made to form a line-shaped pattern with a width of 50 μm in the same manner as in the procedure of (2) of Example 7. The unexposed part could not be removed and the core part could not be formed.

[Comparative Example 5]
The CPU 008 of Comparative Example 2 was used as the core forming resin composition, and CL01 was used as the upper and lower cladding layer forming resin compositions, and the core portion was provided according to the following (1) and (2).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 7.
(2) Formation of core portion Except for using the core-forming resin composition CPU008, an attempt was made to form a linear pattern with a width of 50 μm in the same manner as in the procedure of (2) of Example 7, The unexposed part could not be removed and the core part could not be formed.

[Comparative Example 6]
The CPU 009 of Comparative Example 3 was used as the core forming resin composition, and CL01 was used as the upper and lower cladding layer forming resin compositions, and the core portion was provided according to the following (1) and (2).

(1) Formation of Lower Cladding Layer A lower cladding layer was formed in the same manner as in Example 7.
(2) Formation of core portion Except for using the core-forming resin composition CPU009, an attempt was made to form a line-shaped pattern having a width of 50 μm in the same manner as in the procedure of (2) of Example 7. The unexposed part could not be removed and the core part could not be formed.

The physical property values in Examples 7 to 12 and Comparative Examples 4 to 6 were measured as follows.
1. Alkali developability (2) In the formation of the core part in the examples and comparative examples, 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution (pH 13) or 1% sodium carbonate aqueous solution (pH 11) was used as the developer. At that time, an object that could be patterned on the cured coating film made of the core-forming resin composition was marked with ◯, and an object that could not be patterned was marked with ×. The results are shown in Table 5.

2. Waveguide loss About the film-form optical waveguide produced in Examples 7-10, the light of wavelength 850nm was entered from one end. Then, by measuring the amount of light emitted from the other end, the waveguide loss per unit length was obtained by the cut-back method and used as an index of core transparency. A case where the waveguide loss was 0.5 dB / cm or less was rated as “◯”, and a case where the waveguide loss exceeded 0.5 dB / cm was rated as “x”. The results are shown in Table 5.

3. Bending test The core forming resin composition CPU001 to 006, 008, 009 was applied on a PET film with an applicator, and prebaked at 100 ° C. for 30 minutes. Next, a 50 μm-thick coating film made of the core-forming resin composition was UV-irradiated with a high-pressure mercury lamp with an integrated light amount of 1000 mJ / cm ² , photocured, and laminated on the PET film. This laminated film was bent with a mandrel testing machine and used as an index of flexibility. If the mandrel diameter is 2mm, the film will not crack, and if the laminated film is broken in half by hand, it will be indicated as "<2mm", and the others will indicate the diameter of the mandrel when the crack occurs did. The results are shown in Table 5.

  It can be seen that the optical waveguide film according to the present invention is alkali-developable and excellent in flexibility. In Comparative Example 4, it can be seen that alkali development becomes impossible if the acid value of (A) polythiourethane polyacrylate is too low. Further, Comparative Examples 5 and 6 show that the resin of the present invention is suitable for achieving both flexibility and alkali developability.

  The core-forming resin composition of the present invention can provide a core excellent in alkali developability, transparency, and flexibility, and an optical waveguide produced using the core is tough and has an optical waveguide at a bent portion. Suitable as a film.

DESCRIPTION OF SYMBOLS 1 Optical waveguide 2 Core part 3 Upper clad layer 4 Lower clad layer 5 Base material

Claims (5)

  (A) polythiocarbonate polythiol, (b) acidic group-containing polyol or / and acidic group-containing polythiol, (d) polyisocyanate or / and polyisothiocyanate, and (e) hydroxyl group-containing (meth) acrylate (A) polythiourethane poly (meth) acrylate and (C) photopolymerization initiator obtained, and the acid value of (A) polythiourethane poly (meth) acrylate is 20 to 200 mgKOH / g A resin composition for forming an optical waveguide core. The resin for forming a core of an optical waveguide according to claim 1, wherein the polythiocarbonate polythiol is a polythiocarbonate polythiol having a repeating unit represented by the chemical formula (I) and a number average molecular weight of 200 to 2500. Composition.

(In the formula, R represents a divalent hydrocarbon group, which may have a substituent, and may contain a hetero atom in the carbon chain.)   The resin composition for core formation of an optical waveguide according to claim 1 or 2, further comprising (B) (meth) acrylate having a molecular weight of less than 1000 and having one or more (meth) acryloyl groups in the molecule.   (A) The compounding quantity of component is 50-90 mass% with respect to the total amount of (A)-(B) component, and the compounding quantity of (B) component is with respect to the total amount of (A)-(B) component. The optical waveguide according to claim 3, wherein the content of the component (C) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (B). Core forming resin composition.   An optical waveguide comprising a core portion and a clad layer, wherein the core portion is a cured product of the resin composition for core formation according to any one of claims 1 to 4.

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