JP2010260916A - Photosensitive composition, optical waveguide, optical interconnection, opto-electric hybrid board, electronic equipment and method for forming optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition that synthesizes a functional substituent group-containing polynorbornene by bulk polymerization. <P>SOLUTION: The photosensitive composition includes a photoacid generator, a norbornene-based monomer containing a leaving group to leave at least a part of molecular structure by the action of proton released by the photoacid generator and a catalyst for addition polymerization of the norbornene-based monomer. The norbornene-based monomer of exo body having the leaving group at exo position is present in amounts more than the norbornene-based monomer of endo body having the leaving group at endo position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a novel photosensitive composition and a method for forming an optical waveguide using the same.

  It is known that a polymer obtained by polymerizing norbornene is excellent in physical and chemical properties such as transparency, heat resistance and dimensional stability. Furthermore, polynorbornene having various functional groups introduced into the main chain is used as a material with high added value particularly in the fields of optical materials and electronic materials.

  The polynorbornene having a functional group can be synthesized by addition polymerization of a substituted norbornene monomer having a corresponding functional group. Here, the substituted norbornene having a functional group at the 5th or 6th position of norbornene has two structural isomers, an endo isomer and an exo isomer, depending on the arrangement of the functional group. In general, substituted norbornene having a functional group at the 5- or 6-position synthesized by the Diels-Alder reaction is known to be an endo / exo mixture having a high endo content by the endo rule. .

  In addition polymerization of substituted norbornene having a functional group at the 5-position or 6-position with a palladium (Pd) catalyst, it is known that the exo form is overwhelmingly higher than the endo form. In particular, when the substituents of the substituted norbornene are bulky, it is usually difficult to polymerize the substituted norbornene monomers by the bulk polymerization method, and therefore the solution polymerization method is exclusively employed. For example, Patent Document 1 describes an example in which various norbornene (co) polymers having bulky functional substituents used as optical waveguide materials are synthesized by a solution polymerization method.

Special table 2007-512577 gazette

  When polynorbornene synthesized by a solution polymerization method is used as an optical waveguide, a volume hologram recording medium or other thin film material, it is necessary to prepare a coating composition by re-dissolving in a solvent after reprecipitation. Moreover, when forming a coating film from the coating composition containing a solvent, since a film | membrane becomes thin at the time of drying (solvent removal), control of a film thickness is difficult. Furthermore, use of a solvent is not preferable from an environmental viewpoint. Therefore, a photosensitive composition that can provide polynorbornene having a functional substituent by a bulk polymerization method without such drawbacks is desired.

In order to solve the above-described problems, the present invention provides the following inventions (1) to (15).
(1) For addition polymerization of a photoacid generator, a norbornene monomer having a leaving group capable of leaving at least a part of the molecular structure by the action of a proton released from the photoacid generator, and the norbornene monomer The exo-form norbornene monomer having the leaving group at the exo position is present in excess of the endo-form norbornene monomer having the leaving group at the endo position. A photosensitive composition characterized by comprising:

  (2) The photosensitive composition according to (1), wherein the norbornene monomer substantially comprises the exo norbornene monomer.

（上式中、Ｒ¹〜Ｒ⁴は、それぞれ独立して、水素原子、置換もしくは無置換の炭化水素基、または官能置換基を表すが、その少なくとも一つは前記離脱性基を表し、そしてｍは０〜５の整数を表す。） (3) The photosensitive composition according to (1) or (2), wherein the norbornene-based monomer is represented by the following structural formula (I).

(Wherein R ^{1 to} R ⁴ each independently represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a functional substituent, at least one of which represents the leaving group, and m represents an integer of 0 to 5.)

  (4) The leaving group has at least one selected from the group consisting of an -O- structure, an -Si-aryl structure, and an -O-Si- structure, and any one of (1) to (3) Item 4. The photosensitive composition according to item.

  (5) The photosensitive composition according to any one of (1) to (4), wherein the leaving group has an —O—Si-diphenyl structure.

  (6) The photosensitive composition according to (5), wherein the norbornene-based monomer is diphenylmethylnorbornenemethoxysilane or diphenylmethylnorborneneethoxysilane.

(7) The photosensitive composition according to any one of (1) to (6), wherein the catalyst includes a compound represented by the following formula (Ia).
(E (R) ₃ ) ₂ Pd (Q) ₂ (Ia)
In the above formula, E (R) ₃ represents a neutral electron donor ligand of Group 15, E represents an element selected from Group 15 of the periodic table, and R represents a hydrogen atom or an isotope thereof. Or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate.

(8) The said catalyst is a photosensitive composition of any one of (1)-(7) containing the compound represented by a following formula (Ib).
[(E (R) ₃ ) _a Pd (Q) (LB) _b ] _p [WCA] _r (Ib)
In the above formula, E (R) ₃ represents a neutral electron donor ligand of Group 15, E represents an element selected from Group 15 of the periodic table, and R represents a hydrogen atom or an isotope thereof. Or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate, LB represents a Lewis base, and WCA represents a weakly coordinating anion. , A represents an integer of 1 to 3, b represents an integer of 0 to 2, the sum of a and b is 1 to 3, p and r represent the charges of the palladium cation and the weakly coordinated anion. Represents a number to balance.

  (9) The photosensitive composition according to any one of (1) to (8), further comprising another norbornene-based monomer capable of bulk polymerization with the norbornene-based monomer.

  (10) The photosensitive composition according to any one of (1) to (9), further comprising polynorbornene for viscosity adjustment.

  (11) The photosensitive composition according to any one of (1) to (10), further comprising a solvent.

  (12) The photosensitive composition according to any one of (1) to (11), further comprising a monomer having an oxetanyl group and / or an oligomer having an oxetanyl group.

  (13) An optical waveguide composed of a cured product of the photosensitive composition according to any one of (1) to (12).

  (14) An optical wiring comprising the optical waveguide according to (13).

  (15) An opto-electric hybrid board comprising electrical wiring and the optical wiring according to (14).

  An electronic apparatus comprising the optical waveguide according to (16).

  (17) A light guide comprising a step of forming a thin film of the photosensitive composition according to any one of (1) to (12), and a step of heating the thin film to subject the norbornene monomer to addition polymerization. Method for forming a waveguide.

  (18) The method according to (17), wherein the addition polymerization is performed by bulk polymerization.

  (19) The method according to (17) or (18), further comprising a step of reducing the refractive index of the irradiated region by irradiating a part of the thin film after the addition polymerization with ultraviolet light.

  In the photosensitive composition according to the present invention, polynorbornene having a functional substituent can be provided by a bulk polymerization method when the exo norbornene monomer is present in excess of the endo norbornene monomer. Therefore, since the photosensitive composition according to the present invention can form a photosensitive polymer coating film in a solventless system, the film thickness does not decrease by drying (solvent removal). Further, according to the present invention, it is possible to simplify the process and reduce the environmental load by not using a solvent.

It is the graph which plotted each gelation time with respect to exo body content rate about Example 1 and 2 and Comparative Examples 1-3.

  Hereinafter, although the photosensitive composition by this invention is demonstrated in detail regarding especially the application to an optical waveguide, the use of the photosensitive composition by this invention is not intended to be limited to these. The photosensitive composition according to the present invention includes a photoacid generator, a norbornene monomer having a leaving group capable of leaving at least a part of the molecular structure by the action of a proton released from the photoacid generator, and the norbornene-based monomer. A photosensitive composition comprising a catalyst for addition polymerization of a monomer, the exo norbornene monomer having the leaving group at the exo position, and the endo norbornene system having the leaving group at the endo position It is characterized by being present in excess of the monomer.

  The presence of the exo-form norbornene monomer in excess of the endo-form norbornene-type monomer means that the exo-form exceeds 50 mol% of the total norbornene-type monomer, preferably 70 mol% or more, more preferably 85 mol. % Or more, more preferably 95 mol% or more. For the most efficient bulk polymerization, all norbornene monomers are substantially composed of exo norbornene monomers. That is, endo norbornene monomers are contained only in an impurity amount or less (for example, 1% by mass or less). Most preferably not.

The norbornene monomer according to the present invention can be represented by the following structural formula (I).

In the above formula, R ^{1 to} R ⁴ each independently represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a functional substituent, at least one of which represents the leaving group, and m Represents an integer of 0 to 5.

Examples of the unsubstituted hydrocarbon group (hydrocarbyl group) include, for example, a linear or branched alkyl group having 1 to 10 carbon atoms (C _{1 to} C ₁₀ ), a linear or branched carbon number of 2 -10 (C ₂ -C ₁₀ alkenyl group, linear or branched alkynyl group having 2 to 10 carbon atoms (C ₂ -C ₁₀ ), cycloalkyl having 4 to 12 carbon atoms (C ₄ -C ₁₂ ) Group, a C 4-12 (C ₄ -C ₁₂ ) cycloalkenyl group, a C 6-12 (C ₆ -C ₁₂ ) aryl group, and a C 7-24 (C ₇ -C ₂₄ ) aralkyl group In addition, R ¹ and R ² , R ³ and R ⁴ may each be an alkylidenyl group having 1 to 10 carbon atoms (C _{1 to} C ₁₀ ).

  Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group. , Nonyl and decyl groups, but are not limited thereto. Specific examples of the alkenyl group include, but are not limited to, a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group. Specific examples of the alkynyl group include, but are not limited to, ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group and 2-butynyl group. Specific examples of the cycloalkyl group include, but are not limited to, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Specific examples of the aryl group include, but are not limited to, a phenyl group, a naphthyl group, and an anthracenyl group. Specific examples of the aralkyl group include, but are not limited to, a benzyl group and a phenylethyl (phenethyl) group. Further, specific examples of the alkylidenyl group include, but are not limited to, a methylidenyl group and an ethylidenyl group.

Examples of the substituted hydrocarbon group include those in which some or all of the hydrogen atoms of the hydrocarbon group are substituted with halogen atoms, that is, halohydrocarbyl groups, perhalohydrocarbyl groups. Or halogenated hydrocarbon groups such as perhalocarbyl groups. In these halogenated hydrocarbon groups, the halogen atom substituted with a hydrogen atom is preferably at least one selected from a chlorine atom, fluorine and bromine, more preferably a fluorine atom. Among these, specific examples of the perhalogenated hydrocarbon group (perhalohydrocarbyl group, perhalocarbyl group) include, for example, a perfluorophenyl group, a perfluoromethyl group (trifluoromethyl group), and a perfluoroethyl group. Perfluoropropyl group, perfluorobutyl group, perfluorohexyl group and the like. As the halogenated alkyl group, those having 11 to 20 carbon atoms can be suitably used in addition to those having 1 to 10 carbon atoms. That is, as the halogenated alkyl group, a group that is partially or completely halogenated, linear or branched, and represented by the general formula: —C _Z X ″ _{2Z + 1} can be selected. . Here, X '' represents a halogen atom or a hydrogen atom each independently, and Z represents the integer of 1-20. In addition to the halogen atom, the substituted hydrocarbon group may be a linear or branched alkyl group having 1 to 5 carbon atoms (C ₁ -C ₅ ), a haloalkyl group, an aryl group, and a cycloalkyl group. Examples thereof include a substituted cycloalkyl group, aryl group and aralkyl group (aralkyl group).

Examples of the functional substituent include — (CH ₂ ) _n —CH (CF ₂ ) ₂ —O—Si (Me) ₃ , — (CH ₂ ) _n —CH (CF ₃ ) ₂ —O—CH ₂ —O. _{-CH 3, - (CH 2)} n -CH (CF 3) 2 -O-C (O) -O-C (CH 3) 3, - (CH 2) n -C (CF 3) 2 -OH, _{- (CH 2) n -C (} O) -NH 2, - (CH 2) n -C (O) -Cl, - (CH 2) n -C (O) -O-R 5, - (CH 2 ^{) n-O-R 5,} - (CH 2) n -O-C (O) -R 5, - (CH 2) n -C (O) -R 5, - (CH 2) n -O-C ^{(O) -OR 5, - (} CH 2) n -Si (R 5) 3, - (CH 2) n -Si (OR 5) 3, - (CH 2) n -O-Si (R 5) 3 And — (CH ₂ ) _n —C (O) —OR ^{6 and the} like. Here, in each of the formulas above, each, n is an integer of 0, R ⁵ are each independently a hydrogen atom, a linear or branched C 1 to 20 (C ₁ -C ₂₀₎ alkyl group, a linear or branched halogenated or perhalogenated alkyl group having a carbon number 1 to 20 (C ₁ -C ₂₀₎ linear or branched C 2 to 10 (C ₂ ~ alkenyl group of C _10), a linear or branched alkynyl group having 2 to 10 carbon atoms (C ₂ ~C _10), a cycloalkyl group having 5 to 12 carbon atoms (C ₅ ~C _12), to 6 carbon atoms -14 (C ₆ -C ₁₄ ) aryl group, C 6-14 (C ₆ -C ₁₄ ) halogenated or perhalogenated aryl group or C 7-24 (C ₇ -C ₂₄ ) aralkyl group Represents. Incidentally, the hydrocarbon group represented by R ⁵ represents the same hydrocarbon groups as those represented by R ¹ to R ^4. As represented by R ^{1 to} R ⁴ , the hydrocarbon group represented by R ⁵ may be halogenated or perhalogenated. For example, when R ⁵ is a halogenated or perhalogenated alkyl group having 1 to 20 carbon atoms (C _{1 to} C ₂₀ ), R ⁵ is represented by the general formula: —C _Z X ″ _{2Z + 1} . Here, z and X ″ are the same as defined above, and at least one of X ″ is a halogen atom (for example, a bromine atom, a chlorine atom, or a fluorine atom). Here, the perhalogenated alkyl group is a group in which all X ″ in the general formula is a halogen atom, and specific examples thereof include a trifluoromethyl group, a trichloromethyl group, —C ₇ F _15. Although -C ₁₁ F ₂₃ and the like, but are not limited to. Specific examples of the perhalogenated aryl group include, but are not limited to, a pentachlorophenyl group and a pentafluorophenyl group. Examples of R ⁶ include —C (CH ₃ ) ₃ , —Si (CH ₃ ) ₃ , —CH (R ⁷ ) —O—CH ₂ CH ₃ , —CH (R ⁷ ) OC (CH ₃ ). ₃ and the following cyclic groups.

Here, R ⁷ represents a hydrogen atom or a linear or branched alkyl group having ₁ to ₅ carbon atoms (C _{1 to} C ₅ ). Examples of the alkyl group include methyl group, ethyl group, propyl group, i-propyl group, butyl group, i-butyl group, t-butyl, pentyl group, t-pentyl group, and neopentyl group. In the cyclic group represented by the above chemical formula, an ester bond is formed between the single bond extending from the ring structure and the acid substituent. Specific examples of R ⁶ include, for example, a 1-methyl-1-cyclohexyl group, an isobornyl group, a 2-methyl-2-isobornyl group, a 2-methyl-2-adamantyl group, a tetrahydrofuranyl group, Examples thereof include a tetrahydropyranoyl group, a 3-oxocyclohexanoyl group, a mevalonic lactonyl group, a 1-ethoxyethyl group, and a 1-t-butoxyethyl group. Examples of other R ⁶ include dicyclopropylmethyl group (Dcpm) and dimethylcyclopropylmethyl group (Dmcp) represented by the following.

  At least one of the functional substituents is a leaving group capable of leaving at least a part of the molecular structure by the action of a proton released from the photoacid generator. As such a leaving group, those having at least one of an —O— structure, an —Si—aryl structure and an —O—Si— structure in its molecular structure are preferable. Such a leaving group is released relatively easily by the action of an acid, preferably a proton. Among these, at least one of -Si-diphenyl structure and -O-Si-diphenyl structure is preferable as the leaving group that lowers the refractive index of the polymer obtained by polymerizing the norbornene monomer according to the present invention.

In the photosensitive composition according to the present invention, the exo norbornene-based monomer having the leaving group at the exo position is present in excess of the endo norbornene-based monomer having the leaving group at the endo position. According to this method, first, cyclopentadiene or dicyclopentadiene and acrylonitrile are subjected to a Diels-Alder reaction to provide exo- / endo-norbornenecarbonitrile (exo- / endo-NBCN). The exo- / endo-NBCN obtained here is advantageous in that it becomes a diastereomeric mixture having an endo / exo ratio of about 55:45, and approximately equal amounts of each isomer can be obtained. Furthermore, this exo- / endo-NBCN isomer can be easily separated into each isomer by fractional distillation. After separation of exo-NBCN and endo-NBCN, exo-NBCN is converted to the corresponding exo-norbornene-5-carboxaldehyde (exo-NBCHO) using a suitable reducing agent (eg diisobutylaluminum hydride) can do. Furthermore, the obtained exo-NBCHO can be easily converted to the corresponding exo-norbornene-5-methanol (exo-NBCH ₂ OH) using a suitable hydrogenating agent (eg, sodium borohydride). it can. These conversion reactions proceed very quantitatively and are very advantageous in that the initial isomer purity of exo-NBCN is maintained. Next, by using the alcohol functional group of exo-NBCH ₂ OH, norbornene monomers having various functional substituents can be provided. For example, exo-NBCH by reacting the diphenylmethyl (dimethylamino) silane ₂ OH, -O-Si- diphenyl having a leaving group of structure exo- norbornenyl methoxy diphenylmethyl silane (exo-NBCH ₂ OSiMePh ₂ ) Can be provided. In addition, starting from exo-NBCH ₂ OH or exo-NBCHO, exo-norbornene-5-ethanol (exo-NBCH ₂ CH ₂ OH) can be provided using various types of carbonization reaction (homologation), etc. This can provide a diphenylmethyl (dimethylamino) by reacting the silane exo- norbornenyl ethoxymethyl diphenylmethyl silane _{(exo-NBCH 2 CH 2 OSiMePh} 2). In addition, by using endo-NBCN instead of exo-NBCN in the above preparation procedure, a corresponding endo-derivative can be provided by the same reaction operation. Furthermore, the exo / endo ratio of the norbornene-based monomer can be appropriately adjusted by mixing exo-derivative and endo-derivative separately obtained from exo-NBCN and endo-NBCN at an arbitrary ratio.

  The photosensitive composition according to the present invention can also contain another norbornene-based monomer capable of bulk polymerization with the exo-form norbornene-based monomer having the leaving group at the exo position. Moreover, the photosensitive composition by this invention can also use a crosslinkable norbornene-type monomer (crosslinking agent) with the said exo body norbornene-type monomer. This crosslinkable norbornene-based monomer is a compound capable of causing a crosslinking reaction in the presence of a catalyst precursor described later. The use of the crosslinkable norbornene-based monomer has the following advantages when manufacturing an optical waveguide. That is, since the crosslinkable norbornene-based monomer is polymerized faster, the time required for the formation (process) of the core layer can be shortened. Moreover, since the crosslinkable norbornene-based monomer is difficult to evaporate even when heated, an increase in vapor pressure can be suppressed. Furthermore, since the crosslinkable norbornene monomer is excellent in heat resistance, the heat resistance of the core layer can be improved. As the crosslinkable norbornene-based monomer, there are a compound of a continuous polycyclic ring system and a compound of a linked multicyclic ring system. Examples of the continuous polycyclic ring-based compound (continuous polycyclic ring-based crosslinkable norbornene-based monomer) include the following compounds.

In the above formula, Y represents a methylene (—CH ₂ —) group, and each m independently represents an integer of 0 to 5. However, when m is 0, Y is a single bond. For simplicity, norbornadiene is considered to be included in a continuous polycyclic ring system and includes a polymerizable norbornene double bond. Specific examples of the continuous polycyclic compound include the following compounds, but are not limited thereto.

  On the other hand, examples of the linked polycyclic ring-based compound (linked polycyclic ring-based crosslinkable norbornene-based monomer) include the following compounds.

In the above formula, each a independently represents a single bond or a double bond, each m independently represents an integer of 0 to 5, and each R ⁹ independently represents a divalent hydrocarbon. Represents a group, a divalent ether group or a divalent silyl group. N is 0 or 1. Here, the divalent substituent refers to a group having two bonds that can be bonded to the norbornene structure at the end. Specific examples of the divalent hydrocarbon group (hydrocarbyl group) include an alkylene group represented by the general formula: — (C _d H _2d ) — (d is preferably an integer of 1 to 10). And a divalent aromatic group (aryl group). The divalent alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms (C _{1 to} C ₁₀ ), such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, Examples include a hexylene group, a heptylene group, an octylene group, a nonylene group, and a decylene group. The branched alkylene group is one in which a main chain hydrogen atom is substituted with a linear or branched alkyl group. On the other hand, the divalent aromatic group is preferably a divalent phenyl group or a divalent naphthyl group. The divalent ether group is a group represented by —R ¹⁰ —O—R ¹⁰ —. Here, R < ¹⁰ > represents the same thing as R < ⁹ > each independently. Specific examples of this linked polycyclic compound include, but are not limited to, the following compounds and fluorine-containing compounds (fluorine-containing crosslinkable norbornene monomers) described below.

  The compound is dimethylbis [bicyclo [2.2.1] hept-2-ene-5-methoxy] silane, which is also abbreviated as dimethylbis (norbornenemethoxy) silane (“SiX”). .)

  In the above formula, n represents an integer of 0 to 4.

  In the above formula, m and n each represent an integer of 1 to 4.

  Among various crosslinkable norbornene monomers, dimethylbis (norbornenemethoxy) silane (SiX) is particularly preferable. SiX has a sufficiently low refractive index with respect to a norbornene-based polymer containing a repeating unit of alkylnorbornene and / or a repeating unit of aralkylnorbornene. For this reason, when manufacturing an optical waveguide, the refractive index of the irradiation area | region which irradiates the ultraviolet light mentioned later can be reliably made low, and it can be set as a cladding part. In addition, the difference in refractive index between the core portion and the cladding portion can be increased, and the core layer characteristics (optical transmission performance) can be improved. In addition, you may make it use the above monomers individually or in arbitrary combinations.

  The photosensitive composition according to the present invention contains a photoacid generator that releases protons for releasing at least a part of the leaving group of the norbornene-based monomer. As such a photoacid generator, any compound can be used as long as it is generally activated by irradiation with ultraviolet light and releases an acid. Specific examples of photoacid generators include tetrakis (pentafluorophenyl) borate and hexafluoroantimonate, tetrakis (pentafluorophenyl) gallate, aluminate, antimonate, and other borates. , Gallates, carboranes, halocarboranes and the like. Examples of commercially available photoacid generators include “RHODORSIL (registered trademark, the same shall apply hereinafter) PHOTOINITIATOR 2074 (CAS No. 178233-72-2)” available from Rhodia USA, Cranberry, NJ. “TAG-372R ((dimethyl (2- (2-naphthyl) -2-oxoethyl) sulfonium tetrakis (pentafluorophenyl) borate: CAS No. 193957-), available from Toyo Ink Manufacturing Co., Ltd., Tokyo, Japan. No. 54-9)), “MPI-103 (CAS No. 87709-41-9)” available from Midori Chemical Co., Tokyo, Japan, “Toyo Ink Manufacturing Co., Ltd., Tokyo, Japan” TAG-371 (CAS No. 193957-53-8) ", Sun Country Tokyo available from Toyo Gosei Co., Ltd. "TTBPS-TPFPB (tris (4-tert- butylphenyl) sulfonium tetrakis (penta pentafluorophenyl) borate)", and the like. When RHODORSIL PHOTOINITIATOR 2074 is used as the photoacid generator, a high-pressure mercury lamp or a metal halide lamp is suitably used as the ultraviolet light irradiation means. Thereby, ultraviolet light having sufficient energy of less than 300 nm can be supplied, and RHODORSIL PHOTOINITIATOR 2074 can be efficiently decomposed to generate the acid. The content of the photoacid generator is generally 0.01 to 0.3 parts by mass, preferably 0.02 to 0.2 parts by mass with respect to 100 parts by mass of the norbornene monomer.

  The photosensitive composition according to the present invention preferably contains a catalyst (procatalyst) for addition polymerization of the norbornene-based monomer. Procatalyst is a substance that can start the reaction (polymerization reaction) of the above-mentioned monomer by being activated, and its activation temperature is changed by the action of a photoacid generator activated by irradiation with ultraviolet light. It is. As the procatalyst (also referred to as catalyst precursor), any compound may be used as long as the activation temperature changes (increases or decreases) with irradiation of ultraviolet light. However, when an optical waveguide is produced using the photosensitive composition according to the present invention, it is preferable to use one whose activation temperature decreases with irradiation of ultraviolet light. This is because the core layer can be formed by heat treatment at a relatively low temperature, and it is possible to prevent the characteristics (optical transmission performance) of the optical waveguide from being deteriorated by applying unnecessary heat to other layers.

As such a procatalyst, those containing (mainly) at least one of the compounds represented by the following formulas (Ia) and (Ib) are preferably used.
(E (R) ₃ ) ₂ Pd (Q) ₂ (Ia)
[(E (R) ₃ ) _a Pd (Q) (LB) _b ] _p [WCA] _r (Ib)
In formulas Ia and Ib, each E (R) ₃ represents a neutral electron donor ligand of group 15, E represents an element selected from group 15 of the periodic table, and R is It represents a moiety containing a hydrogen atom (or one of its isotopes) or a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate. In Formula Ib, LB represents a Lewis base, WCA represents a weakly coordinating anion, a represents an integer of 1 to 3, b represents an integer of 0 to 2, and a and b , P and r represent numbers that balance the charge of the palladium cation and the weakly coordinated anion.

Typical procatalysts according to Formula Ia include Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ , Pd (OAc) ₂ (P (Cy) ₃ ) ₂ , Pd (O ₂ CCMe ₃ ) ₂ ( P (Cy) ₃ ) ₂ , Pd (OAc) ₂ (P (Cp) ₃ ) ₂ , Pd (O ₂ CCF ₃ ) ₂ (P (Cy) ₃ ) ₂ , Pd (O ₂ CC ₆ H ₅ ) ₃ ( P (Cy) ₃ ) ₂ may be mentioned, but is not limited thereto. Here, Cp represents a cyclopentyl group, and Cy represents a cyclohexyl group.

The procatalyst represented by the formula Ib is preferably a compound in which p and r are selected from integers of 1 and 2, respectively. A typical procatalyst according to such a formula Ib is Pd (OAc) ₂ (P (Cy) ₃ ) ₂ . Here, Cy represents a cyclohexyl group, and Ac represents an acetyl group.

  These procatalysts can efficiently react with a monomer (in the case of a norbornene-based monomer, an efficient polymerization reaction, a crosslinking reaction, etc. by an addition polymerization reaction).

Further, in a state where the activation temperature is lowered (active latent state), as a procatalyst, the activation temperature is lower by about 10 to 80 ° C. (preferably about 10 to 50 ° C.) than the original activation temperature. Those are preferred. Thereby, the refractive index difference between the core part and the clad part in the core layer can be surely generated. As such a procatalyst, a catalyst containing (mainly) at least one of Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ and Pd (OAc) ₂ (P (Cy) ₃ ) ₂ is preferable. It is. Hereinafter, Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ may be abbreviated as “Pd545”, and Pd (OAc) ₂ (P (Cy) ₃ ) ₂ may be abbreviated as “Pd785”. .

  The photosensitive composition according to the present invention may contain polynorbornene for viscosity adjustment. Such polynorbornene may be either one having a single repeating unit (homopolymer) or one having two or more norbornene-based repeating units (copolymer). Examples of such polynorbornene include (1) addition (co) polymer of norbornene monomer obtained by addition (co) polymerization of norbornene monomer, and (2) norbornene monomer and ethylene or α-olefins. (3) addition polymers such as (3) norbornene-type monomers and non-conjugated dienes, and addition copolymers with other monomers as necessary, and (4) ring-opening of norbornene-type monomers (copolymerization) ) A polymer, and a resin obtained by hydrogenating the (co) polymer if necessary; (5) a ring-opening copolymer of a norbornene monomer and ethylene or α-olefin; ) A polymer-hydrogenated resin, (6) a ring-opening copolymer of a norbornene-type monomer and a non-conjugated diene, or other monomer, and, if necessary, the (co) polymer in water Examples thereof include ring-opening polymers such as a polymer added with an element. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers. These polynorbornenes are, for example, ring-opening metathesis polymerization (ROMP), combination of ROMP and hydrogenation reaction, polymerization by radical or cation, polymerization using cationic palladium polymerization initiator, other polymerization initiators (for example, , Polymerization using nickel or other transition metal polymerization initiators) and the like. When polynorbornene is included, the molecular weight and content of the polynorbornene can be appropriately determined according to the desired viscosity of the photosensitive composition of the present invention. For example, when preparing a varnish for producing an optical waveguide using the photosensitive composition according to the present invention, the viscosity (room temperature) is preferably about 100 to 10000 cP, depending on the coating method described below and the desired film thickness. The molecular weight and addition amount of polynorbornene may be appropriately adjusted so that it is more preferably about 150 to 5000 cP, and more preferably about 200 to 3500 cP.

  The photosensitive composition by this invention can contain a solvent as needed. Examples of the solvent include diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether. Ether solvents such as (carbitol), cellosolve solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, aroma such as toluene, xylene, benzene, mesitylene Aromatic hydrocarbon solvents, aromatic heterocyclic compounds such as pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, N, N-dimethylformamide (DMF), N, N Amide solvents such as dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform, 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate, ethyl formate, dimethyl sulfoxide (DMSO), sulfolane, etc. Examples include various organic solvents such as sulfur compound-based solvents or mixed solvents containing these. When preparing a varnish for producing an optical waveguide using the photosensitive composition according to the present invention, the viscosity (normal temperature) is preferably about 100 to 10000 cP, depending on the coating method described below and the desired film thickness. The amount of the solvent may be adjusted as appropriate so that it is preferably about 150 to 5000 cP, more preferably about 200 to 3500 cP.

  The photosensitive composition by this invention can contain a sensitizer as needed. The sensitizer increases the sensitivity of the photoacid generator to ultraviolet light, reduces the time and energy required for activation (reaction or decomposition), and changes the wavelength of ultraviolet light to a wavelength suitable for activation. It has a function to change. Such a sensitizer is appropriately selected according to the sensitivity of the photoacid generator and the peak wavelength of absorption of the sensitizer, and is not particularly limited. For example, 9,10-dibutoxyanthracene (CAS No. 76275-14-4) anthracenes, xanthones, anthraquinones, phenanthrenes, chrysene, benzpyrenes, fluoranthenes, rubrenes, pyrenes, indanthrines, thioxanthene-9- Examples thereof include thixanthen-9-ones, and these are used alone or as a mixture. Specific examples of the sensitizer include 2-isopropyl-9H-thioxanthen-9-one, 4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthone, phenothiazine, and these Of the mixture. 9,10-dibutoxyanthracene (DBA) can be obtained from Kawasaki Kasei Kogyo Co., Ltd., Kanagawa, Japan. The content of the sensitizer in the varnish is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. preferable. In addition, it is preferable that an upper limit is 5 mass% or less.

  Furthermore, the photosensitive composition by this invention can contain antioxidant as needed. Thereby, generation of undesirable free radicals and natural oxidation of the polymer can be prevented. As a result, the characteristics of the obtained core layer can be improved. Examples of the antioxidant include Ciba (registered trademark, the same applies hereinafter) IRGANOX (registered trademark, the same applies hereinafter) 1076 and Ciba IRGAFOS (registered trademark, available) from Ciba Specialty Chemicals of Tarrytown, New York. The same applies hereinafter.) 168 is preferably used. As other antioxidants, for example, Ciba Irganox (registered trademark, hereinafter the same) 129, Ciba Irganox 1330, Ciba Irganox 1010, Ciba Cyanox (registered trademark, the same shall apply) 1790, Ciba Irgan. (Registered trademark) 3114, Ciba Irganox 3125, etc. can also be used.

  The photosensitive composition according to the present invention may further contain a monomer having an oxetanyl group and / or an oligomer having an oxetanyl group. By including such a monomer or oligomer, a photosensitive composition capable of suppressing light propagation loss can be obtained. Specifically, by irradiating light to a photosensitive composition containing a monomer having an oxetanyl group and / or an oligomer having an oxetanyl group, an acid is generated from the photoacid generator, and in the irradiated part, the monomer and / or The oligomer is polymerized. Since the amount of the monomer and / or oligomer in the irradiated part is reduced, the monomer and / or oligomer in the non-irradiated part diffuses to the irradiated part in order to eliminate the concentration gradient generated between the irradiated part / unirradiated part, A difference in refractive index occurs between the irradiated portion and the unirradiated portion. Further, when heating is performed after light irradiation, the monomer and / or oligomer are volatilized from the unirradiated portion. As a result, a difference in refractive index occurs between the irradiated portion and the unirradiated portion. As a result, light can be reliably confined and propagation loss of light can be suppressed.

  As the monomer having an oxetanyl group and the oligomer having an oxetanyl group, those selected from the group of the following compounds (11) to (20) are preferable. By using these, there is an advantage that transparency in the vicinity of a wavelength of 850 nm is excellent and flexibility and heat resistance can be compatible. The monomer having an oxetanyl group and the oligomer having an oxetanyl group may be used alone or in combination.

式（１８）においてｎは０以上、３以下である。

In Formula (18), n is 0 or more and 3 or less.

  Among the compounds (11) to (20), particularly from the viewpoint of securing a difference in refractive index from the addition (co) polymer of the norbornene monomer according to the present invention, the compounds (13), (15), (16), It is preferable to use (17) or (20). In addition, the compound (15) or (20) has a large refractive index difference from the norbornene-based monomer addition polymer according to the present invention, a small molecular weight and a high diffusibility of the monomer, and the monomer does not easily volatilize. It is particularly preferred to use

  Moreover, the following compounds (32) or (33) can be used as a monomer having an oxetanyl group and an oligomer having an oxetanyl group. As compound (32), trade name TESOX manufactured by Toagosei Co., Ltd. can be used, and as product (33), trade name OX-SQ manufactured by Toagosei Co., Ltd. can be used.

(In formula (33), n is 1 or 2)

  The monomer having an oxetanyl group and the oligomer having an oxetanyl group are preferably 1 to 50 parts by mass with respect to 100 parts by mass of the norbornene monomer according to the present invention. Especially, 2-20 mass parts is preferable. Thereby, the refractive index modulation between the core and the clad is possible, and there is an effect that both flexibility and heat resistance can be achieved.

  The present invention further provides a method for forming an optical waveguide using the photosensitive composition. The method for forming an optical waveguide according to the present invention comprises a step of forming a thin film of the photosensitive composition, and a step of heating the thin film to subject the norbornene-based monomer to addition polymerization. The step of forming a thin film of the photosensitive composition can be carried out by forming a coating film on the support substrate using the photosensitive composition as a varnish. As the supporting substrate, a silicon wafer, a silicon dioxide substrate, a glass substrate, a quartz substrate, a polyethylene terephthalate (PET) film, or the like may be used. Examples of the coating method include, but are not limited to, a doctor blade method, a spin coating method, a dipping method, a table coating method, a spray method, an applicator method, a curtain coating method, and a die coating method. The thickness of the thin film is not particularly limited, but may be about 5 to 200 μm, preferably about 15 to 125 μm, more preferably about 25 to 100 μm before drying.

  Subsequently, the norbornene-type monomer is addition-polymerized by heating the obtained thin film. The heating may be carried out at a temperature and time sufficient to subject the norbornene-based monomer to addition polymerization, and is generally 45 to 120 ° C, preferably 85 to 100 ° C and generally 10 to 120 minutes, preferably 60 to 90 minutes. The time is a guide. There is no particular limitation on the heating means, but a method of heating a support substrate carrying a thin film on a hot plate is convenient. Thus, the photosensitive composition according to the present invention can form a polynorbornene thin film having a functional substituent in a solvent-free system. For this reason, the film thickness does not decrease due to drying (solvent removal), and simplification of the process and reduction of the environmental load can be achieved by not using the solvent. However, it does not exclude the use of a solvent for the convenience of thin film formation work, etc., and when the photosensitive composition according to the present invention contains a solvent, before the addition polymerization of the norbornene-based monomer or the addition polymerization. During the heating, the solvent in the thin film can be removed. Solvent removal (drying) methods include standing under atmospheric pressure or reduced pressure, and spraying (blowing) inert gas, etc., but placing a support substrate carrying a thin film on a hot plate The method of heating is preferable. The heating temperature for drying depends on the solvent used, but is generally 25 to 60 ° C., preferably 30 to 45 ° C. The heating time is generally in the range of 15 to 60 minutes, preferably 15 to 30 minutes.

  The obtained polynorbornene thin film can be selectively irradiated with ultraviolet light without being peeled from the support substrate. As a method for selectively irradiating ultraviolet light, a mask (masking) having openings (windows) formed therein is prepared, and the polynorbornene coating can be irradiated with ultraviolet light through this mask. The irradiation region of the ultraviolet light becomes a clad portion having a reduced refractive index. Therefore, an opening (window) equivalent to the pattern of the clad portion to be formed is formed in the mask. This opening forms a transmission part through which the irradiated ultraviolet light is transmitted. The mask may be formed in advance (separately formed) (for example, plate-shaped) or may be formed on the polynorbornene film by, for example, a vapor deposition method or a coating method. Examples of preferable masks include photomasks made of quartz glass or PET base materials, stencil masks, metal thin films formed by vapor deposition methods (evaporation, sputtering, etc.), etc. Among these, it is particularly preferable to use a photomask or a stencil mask. This is because a fine pattern can be formed with high accuracy, and handling is easy, which is advantageous in improving productivity.

The ultraviolet light to be used is not limited as long as it can cause a photochemical reaction (change) to the photoacid generator. In particular, ultraviolet light is appropriately selected depending on the type of photoacid generator used, and the type of sensitizer when it contains a sensitizer, and has a peak wavelength in the range of 200 to 450 nm. It is preferable to do. The irradiation amount of ultraviolet light is preferably in the range of about 0.1~9J / cm ^2, more preferably about 0.2~6J / cm ^2, at about 0.2~3J / cm ² More preferably. Thereby, a photo-acid generator can be activated reliably.

When the polynorbornene film is irradiated with ultraviolet light through a mask, the release agent present in the irradiated region irradiated with ultraviolet light reacts (bonds) or decomposes by the action of ultraviolet light, and becomes a cation (proton or other). Cation) and weakly coordinating anion (WCA) are released (generated). Then, the cation causes the leaving group itself to leave the main chain, or cleaves from the middle of the molecular structure of the leaving group (photo bleach). Thereby, in the irradiated region, the number of the leaving groups in a complete state is decreased as compared with the non-irradiated region, and the second refractive index lower than the first refractive index is lowered. At this time, the first refractive index is maintained as the refractive index of the unirradiated region. In this way, a refractive index difference (second refractive index <first refractive index) occurs between the irradiated region and the unirradiated region, and in the case of manufacturing an optical waveguide, the core portion (unirradiated region) And a cladding part (irradiation region) are formed. In this case, the irradiation amount of ultraviolet light is preferably in the range of about 0.1~9J / cm ^2, more preferably about 0.3~6J / cm ^2, 0.6~6J / cm More preferably, it is about ² . Thereby, a release agent can be activated reliably.

  Next, heat treatment is performed on the polynorbornene film after irradiation with ultraviolet light as necessary. By the heat treatment, the leaving group detached (cut) from the polymer is removed from, for example, the irradiated region, or rearranged or crosslinked in the polymer. Furthermore, at this time, it is considered that a part of the leaving group remaining in the cladding part (irradiation region) is further detached (cut). Therefore, by performing such heat treatment, the refractive index difference between the core portion and the cladding portion in the optical waveguide can be further increased. Although the heating temperature in this heat processing is not specifically limited, It is preferable that it is about 70-195 degreeC, and it is more preferable that it is about 85-150 degreeC. The heating time is set so as to sufficiently remove the leaving group that has been detached (cleaved) from the irradiation region, and is not particularly limited, but is preferably about 0.5 to 3 hours, 0.5 to More preferably, it is about 2 hours. Moreover, the process of 1 time or several times of heat processing (for example, about 150-200 degreeC x about 1 to 8 hours) can also be added as needed. For example, when a sufficient refractive index difference is obtained between the core portion and the clad portion before the heat treatment, such a heating step can be omitted. Through the above steps, a core layer including a core portion and a cladding portion is formed. Thereafter, the core layer is peeled from the support substrate.

  In a preferred embodiment, the core part and the clad part are composed mainly of a norbornene-based polymer having a main chain and a main chain branched from the main chain and having a leaving group capable of leaving at least a part of the molecular structure from the main chain, The core part and the clad part have different refractive indexes due to the difference in the number of leaving groups bonded to the main chain.

  When the polynorbornene coating is further compatible with the polynorbornene and further contains a monomer and a procatalyst having a refractive index different from that of the polynorbornene coating, when the polynorbornene coating is irradiated with ultraviolet light through a mask, The photoacid generator present in the irradiated region irradiated with light reacts or decomposes by the action of ultraviolet light to release cations (protons or other cations) and weakly coordinating anions (WCA) ( appear. These cations and weakly coordinating anions cause a change (decomposition) in the molecular structure of the procatalyst existing in the irradiation region, and change this into an active latent state (latent active state). Here, an active latent state (or potential active state) procatalyst has an activation temperature that is lower than the original activation temperature, but there is no temperature increase, that is, within the irradiation region at room temperature. The catalyst precursor in a state in which the reaction of the monomer cannot occur. Therefore, even after irradiation with ultraviolet light, if the polynorbornene coating is stored at, for example, about -40 ° C, the state can be maintained without causing the reaction of the monomer. For this reason, it is highly convenient in that a core layer can be obtained by preparing a plurality of polynorbornene coatings after irradiation with ultraviolet light and subjecting them to heat treatment at once.

  Note that the use of a mask may be omitted when highly directional light such as laser light is used as ultraviolet light.

  Next, heat treatment (first heat treatment) is performed on the polynorbornene coating. Thereby, in the irradiation region, the active catalyzed procatalyst is activated (becomes active), and monomer reaction (polymerization reaction or crosslinking reaction) occurs. As the monomer reaction proceeds, the monomer concentration in the irradiated region gradually decreases. As a result, there is a difference in monomer concentration between the irradiated region and the unirradiated region, and in order to eliminate this, the monomer diffuses from the unirradiated region and collects in the irradiated region. As a result, in the irradiated region, the monomer and its reactant (polymer, cross-linked structure or branched structure) increase, and the structure derived from the monomer greatly affects the refractive index of the region, and the first refractive index Lower to a lower second refractive index. As the monomer polymer, an addition (co) polymer is mainly produced. On the other hand, in the unirradiated region, the amount of monomer decreases due to the diffusion of the monomer from the region to the irradiated region, so that the influence of the polymer greatly appears in the refractive index of the region, which is higher than the first refractive index. It rises to the third refractive index. In this way, a refractive index difference (second refractive index <third refractive index) occurs between the irradiated region and the unirradiated region, and the core portion (unirradiated region) and the cladding portion (irradiated region) Is formed. Although the heating temperature in this 1st heat processing is not specifically limited, It is preferable that it is about 30-80 degreeC, and it is more preferable that it is about 40-60 degreeC. Further, the heating time is preferably set so that the reaction of the monomer in the irradiated region is almost completed. Specifically, the heating time is preferably about 0.1 to 2 hours, preferably about 0.1 to 1 hour. It is more preferable that

  Next, a second heat treatment is performed on the polynorbornene coating. As a result, the monomer remaining in each region can be activated by activating the procatalyst remaining in the unirradiated region and / or the irradiated region, either directly or with the activation of the photoacid generator. React. In this way, by reacting the monomer remaining in each region, the obtained core portion and cladding portion can be stabilized. The heating temperature in the second heat treatment is not particularly limited as long as it can activate the procatalyst or the photoacid generator, but it is preferably about 70 to 100 ° C, and about 80 to 90 ° C. More preferably. The heating time is preferably about 0.5 to 2 hours, more preferably about 0.5 to 1 hour.

  Next, a third heat treatment is performed on the polynorbornene coating. Thereby, reduction of internal stress generated in the obtained core layer and further stabilization of the core part and the clad part can be achieved. The heating temperature in the third heat treatment is preferably set to 20 ° C. or more higher than the heating temperature in the second heat treatment, specifically, preferably about 90 to 180 ° C., 120 to 160 ° C. More preferred is the degree. The heating time is preferably about 0.5 to 2 hours, more preferably about 0.5 to 1 hour. Through the above steps, a core layer including a core portion and a cladding portion is formed. Then, an optical waveguide (single layer) is formed by peeling the core layer from the support substrate.

Next, the optical wiring, the opto-electric hybrid board, and the electronic device will be briefly described.
The optical wiring of the present invention has the optical waveguide as described above. Thereby, since it is not necessary to go through development, RIE (reactive ion etching), or the like in the waveguide manufacturing process, the degree of freedom in processing can be improved.

  Moreover, the opto-electric hybrid board of the present invention has an electrical wiring and an optical wiring having the optical waveguide as described above. As a result, it is possible to improve EMI (electromagnetic wave interference), which has been a problem with conventional electrical wiring, and the signal transmission speed can be significantly improved as compared with the conventional case.

The electronic device of the present invention has the optical waveguide as described above. Thereby, space saving can be achieved.
Specific examples of such an electronic device include a computer, a server, a mobile phone, a game device, a memory tester, and an appearance inspection robot.

Hereinafter, the present invention will be specifically described by way of examples.
Reference example: Preparation of Exo norbornene monomer

<Synthesis of exo- / endo-norbornenecarbonitrile (exo- / endo-NBCN)>
A 20 liter per pressure reactor was flushed with nitrogen (N ₂ ) and then charged with 6.8 kg (51.3 moles, 1.1 equivalents of cyclopentadiene) of dicyclopentadiene. Then 5.11 kg (96.3 mol, 1.0 eq) acrylonitrile was charged. The reactor was flushed 3 times with N ₂ and then heated to a temperature of about 180 ° C. over 3.25 hours. During this first 3.25 hours, it was observed that the pressure peak reached about 100 psig. The reaction mixture was stirred at about 180 ° C. for an additional 2 hours, during which time the pressure stabilized at about 11 psig. After cooling to 25 ° C., 11.81 kg of reaction mixture was removed from the reactor. GC analysis of the mixture showed that exo / endo norbornenecarbonitrile (43.3% / 56.6%) was produced in 93.0% yield. The GC retention times were 4.0 minutes (exo-NBCN) and 4.7 minutes (endo-NBCN).

<Separation / purification of exo- / endo-norbornenecarbonitrile>
About 8 kg of exo was added to a vacuum distillation apparatus consisting of an appropriately sized distillation pot with a heating mantle, packed distillation column (theoretical plate number 60), reflux splitter, water-cooled condenser, condensate receiver, and vacuum pump. -/ endo-norbornenecarbonitrile (NBCN) was loaded. The distillation pot temperature was controlled by adjusting the amount of heat input to the heating mantle, and the system vacuum was controlled by adjusting the vacuum pressure in the overhead receiver (see Table 1 below). After transferring the NBCN to the distillation pot, the vacuum of the distillation system was adjusted to the desired set point. The distillation pot was then heated to establish a total reflux state in the distillation column. The reflux splitter was then started at the desired reflux ratio and fractional distillation proceeded by periodically removing the liquid fraction from the overhead receiver. The composition of the overhead liquid fraction was determined by GC analysis. The composition of the overhead stream was changed by adjusting the distillation reflux ratio as needed. The initial overhead fraction mainly contained a large amount of light components such as acrylonitrile, cyclopentadiene and dicyclopentadiene. After removing these light fractions, high purity exo-NBCN was separated from the remaining endo-NBCN. After removing the “transition” fraction, high purity endo-NBCN was collected. The distillation process was stopped when most of the endo-NBCN was removed from the distillation pot.

Table 1
Supply NBCN (exo: endo ratio = 1: 3)
Distillation pot temperature: exo-NBCN 127 ° C; endo-NBCN 125 ° C
Overhead temperature: exo-NBCN 57 ° C; endo-NBCN 85 ° C
System vacuum: exo-NBCN 2.0 mmHg; endo-NBCN 1.7 mmHg
Reflux ratio: exo-NBCN 30: 1; endo-NBCN 5: 1

  About 57% of exo-NBCN contained in the starting mixture was isolated as high purity (> 98%). About 44% of endo-NBCN contained in the starting mixture was isolated as high purity (98% or more). By reusing the intermediate purity fraction, the overall process yield can be increased.

<Synthesis of exo-norbornene-5-carboxaldehyde (exo-NBCHO)>
A 12-liter glass flask equipped with a mechanical stirrer, nitrogen gas inlet, thermowell, and addition funnel was heated to 120 ° C. and dried under a nitrogen flush. After cooling the flask to room temperature, 7900 mL (11.79 mol) of a 1.5 M diisobutylaluminum hydride (DIBAL-H) toluene solution was charged to the flask from the addition funnel. After cooling the DIBAL-H solution to −51.6 ° C., exo-NBCN (1328 g, 11.14 mol) was added dropwise. The dropwise addition was completed within 2 hours and 24 minutes, during which the temperature fluctuation was in the range of -51.6 to -39.3 ° C. The mixture was stirred for an additional 30 minutes. In GC analysis, residual unreacted exo-NBCN was not detected. While maintaining the reaction mixture in the temperature range of -46 to -39 ° C, it was divided into 11 portions of 500 mL and poured into an addition funnel with a dry ice / isopropanol cooling jacket through a cannula. The reaction mixture divided into 11 portions each having 500 mL was rapidly added dropwise to mechanically stirred 3.5N hydrochloric acid having a volume of 12.24 liters cooled to −5.6 ° C. with dry ice / acetonitrile. After the reaction exotherm had subsided, the subsequent DIBAL-H reaction mixture was added. The temperature variation was in the range of -5.6 to + 0.1 ° C. The cooling time was 2 hours. MTBE (methyl tert-butyl ether, 4000 mL) was added from a cooled addition funnel. The mixture was stirred for several minutes, allowed to settle, and phase separated. The aqueous phase was extracted with 3 × 4000 mL MTBE. The organic portions were combined and washed with 5000 mL of 3.5N hydrochloric acid and 3 × 2 gallons of brine until the final wash pH was 6. The MTBE / toluene solution was placed in 7 bottles, dried over sodium sulfate, and stored overnight in a refrigerator. The mixture was filtered and subjected to a rotary evaporator at a maximum bath temperature of 35 ° C. to give 3173 g of product. NMR analysis showed 35.2 wt% NBCHO in toluene, 82% yield. The exo / endo ratio by GC analysis was 99.8 / 0.2. Since NBCHO is unstable and easily isomerized, the solution was stored refrigerated for later use. The GC retention times were 2.05 minutes (exo-NBCHO) and 2.23 minutes (endo-NBCHO).

<Synthesis of exo-norbornene-5-methanol (exo-NBCH ₂ OH)>
A glass flask having a capacity of 22 liters equipped with a mechanical stirrer, a nitrogen gas inlet, a thermowell, and an addition funnel was charged with 1880 mL of an 8% aqueous sodium hydroxide solution. NaBH ₄ (174.1 g, 4.6 mol) was added in small portions. The mixture was cooled to -7.4 ° C. Immediately before use, exo-NBCHO (3173 g as a 35.2 mass% toluene solution, about 9.17 mol in total) was divided into 400 mL portions, dissolved in 600 mL methanol, and then added dropwise to the sodium borohydride solution. The total addition time was 5.1 hours, during which the reaction temperature varied between -7.1 and -0.8 ° C. An additional 35 g of sodium borohydride was added due to inconsistent GC analysis. The reaction mixture was cooled from -1.7 ° C to -12.7 ° C with stirring for 1 hour. The amount of unreacted NBCHO by GC analysis was less than 0.15%. A 10% aqueous sulfuric acid solution (2200 mL) was added dropwise over 1.5 hours, during which the temperature fluctuated in the range of −11.4 to + 0.7 ° C. The final pH was 6. Dichloromethane (3000 mL), 500 mL brine and 2000 mL water were added and the mixture was stirred for several minutes. Separated into multiple phases. The remaining aqueous phase was treated with 2000 mL dichloromethane, 2000 mL water, and 2000 mL brine. The dichloromethane phase was withdrawn and the aqueous phase was again mixed with 2000 mL dichloromethane, 2000 mL water and 2000 mL brine. The dichloromethane phase was withdrawn and the aqueous phase was treated with 2000 mL dichloromethane and 2000 mL water. The dichloromethane extracts were combined and the residual water was separated, after which the organic portion was dried over sodium sulfate overnight. After filtration, the extract was subjected to a rotary evaporator to obtain 1210 g of a yellow liquid (yield 87% from NBCHO).

When the liquid was subjected to vacuum distillation, the following fractions were obtained.
1) 34.6-109.4 ° C. (12-20 torr), 46.2 g, opaque, NBMeOH 60.3%, toluene 39.7% by weight
2) 106.3-100.7 ° C. (5-8 Torr), 172.5 g, exo-NBMeOH 98.5%, endo-NBMeOH 1.3%, no toluene 3) 81.4-93.2 ° C. (2- 3 Torr), 236.7 g, exo-NBMeOH 99.3%, endo-NBMeOH 0.7%, no toluene 4) 62.2-69.4 ° C. (1-2 Torr), 578.1 g, exo-NBMeOH 99.1 %, Endo-NBMeOH 0.9%
5) 63.1-68.5 ° C. (1 torr), 29.02 g, exo-NBMeOH 99.5%, endo-NBMeOH 0.5%

  The distillation pot residue was dissolved in about 400 mL of dichloromethane and washed with 100 mL of 10% sulfuric acid. The resulting mixture was treated with 100 mL of water and phase separated. These phases were separated. 100 mL brine was added to the aqueous phase to further separate dichloromethane from the solution. The dichloromethane portion was combined and washed with 5 × 100 mL brine to pH 6 and dried over sodium sulfate. The dried extract was filtered and subjected to a rotary evaporator. When this product was distilled under reduced pressure, 37.7 g was obtained as a fraction of 60.8 to 65.1 ° C. (1 torr). According to GC analysis, the endo isomer was 0.5% and the exo isomer was 99.5%. The lower purity fraction, 37.31 g, was obtained in 63.1-65.2 (2 torr), containing 98.9% exo isomer and 0.85% endo isomer. (All isomers) The total yield with a purity of 99.8% or more was 1058.5 g (yield from NBCN: 76.5%, yield from NBCHO: about 93%). The GC retention times were 2.82 minutes (endo-NBMeOH) and 3.97 minutes (exo-NBMeOH).

<Exo⁻ Synthesis of norbornenyl methoxy diphenylmethyl silane _{(exo-NBCH 2 OSiMePh 2)} >
A 500-mL glass jacketed 5-necked reactor was charged with exo-norbornenylmethanol (96 g, 0.77 mol) and sparged with nitrogen. The reactor was heated in a heated / cooled circulating water bath at a set temperature of 75 ° C. Diphenylmethyl (dimethylamino) silane (171 g, 0.71 mol) was added dropwise through an addition funnel at an internal temperature of 75 ° C. so that no exothermic reaction occurred. Subsequently, the temperature in the reactor was raised to 100 ° C., the temperature was maintained for up to 24 hours, sampling and quantification were performed by GC, and it was confirmed that the dimethylamine content in the reactor was less than 1%. The reactor was connected to an acid-base scrubber to neutralize dimethylamine. The reaction mixture was cooled and collected in a bottle. The crude product of exo-norbornenylmethoxydiphenylmethylsilane (209 g, 71% yield) was purified by short path top distillation set at 150 ° C. and 60 mtorr to yield 140 g of colorless liquid (> 98%, containing exo) 100%) was obtained. Proton NMR confirmed the presence of only exo-NBCH ₂ OSiMePh _2, indicating that the diastereomeric purity of the starting material was maintained.

Example 1
(Preparation of varnish)
In yellow room capable of blocking ultraviolet rays, glass bottle volume 100 mL, the _{exo-NBCH 2 OSiMePh 2 (10.0g} , 3.1 × 10 -2 mol) and antioxidants [Ciba Corp. Irganox (registered trademark) 1076 (0.1 g) and Irgafos® 168 (0.03 g)] and catalyst [Pd (P (iPr) ₃ ) ₂ (OCOCH ₃ ) (NCCH ₃ )] tetrakis (pentafluorophenyl) borate (promelas) Pd-1206) (3.0 × 10 ⁻³ g, 2.5 × 10 ⁻⁶ mol) and N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate (DANFABA) (8.0 × 10 6) ^-3 g, 1.0 × 10 ⁻⁵ mol) and a photoacid generator [RHODORSIL® PHOTOINITIATOR 2074 (CAS No. 17823) 3-72-2) (1.0 × 10 ⁻² g, 1.0 × 10 ⁻⁵ mol)] was added and sufficiently stirred to dissolve uniformly. The resulting colorless and transparent solution was filtered through a filter having a pore diameter of 0.2 μm to prepare varnish V1.

(Thin film formation)
A silicon wafer with a SiO ₂ film having a diameter of 10.16 cm (4 inches) was set on a spin coater (model number MS-A200 manufactured by Mikasa Corporation). 10 g of the varnish V1 was placed in the center of the wafer and rotated at 150 rpm for 30 seconds to uniformly apply the varnish to the entire surface of the wafer. Then, the wafer was taken out from the spin coater and placed in 80 ° C. on a hot plate and allowed to stand for 10 minutes to obtain a cured film (thin film) by promoting the polymerization of the exo-NBCH ₂ OSiMePh _2.

(Production of single-layer optical waveguide)
The thin film was irradiated with 1000 mJ of UV light (365 nm) through a quartz photomask. Subsequently, it heated for 1 hour in 150 degreeC drying machine. It was possible to visually confirm a clear optical waveguide pattern in the heated thin film.

(Measurement of gelation time)
In order to measure the accurate gelation time of the varnish V1, 2 ml of varnish was applied to an area of 1 cm ² on a hot plate at 85 ° C., and the time until gelation was measured while gently stirring with a metal spatula 30 Second. The gelation time means the time until the varnish becomes highly viscous and does not pull the yarn.

Example 2
Except using the exo-NBCH ₂ OSiMePh ₂ in place of Arakawa Chemical Industries, Ltd. DiPhNB-X (endo 40% / exo 60% -NBCH 2 OSiMePh 2 10.0g, 3.1 × 10 -2 mol) A varnish was prepared in the same manner as in Example 1, and an attempt was made to form a thin film and create a waveguide. The gelation time at 85 ° C. of the varnish used was 101 seconds.

Comparative Example 1
DiPhNB-X (6.5 g, 2.0 × 10 ⁻² mol) and DiPhNB manufactured by Arakawa Chemical Industries (endo 80% / exo 20% -NBCH ₂ OSiMePh ₂ 3.5 g, 1.1 × 10 ⁻² mol) In addition, a varnish was prepared in the same manner as in Example 1 except that the exo body content in the mixture was adjusted to 46%, and an attempt was made to form a thin film and create a waveguide. In addition, it was 174 seconds when the gelation time in 85 degreeC of the used varnish was measured.

Comparative Example 2
DiPhNB-X (2.4 g, 7.5 × 10 ⁻³ mol) and DiPhNB (7.6 g, 2.4 × 10 ⁻² mol) are used in combination, and the exo content in the mixture is 30%. A varnish was prepared in the same manner as in Example 1 except that it was prepared as described above, and an attempt was made to form a thin film and create a waveguide. In addition, it was 272 seconds when the gelation time in 85 degreeC of the used varnish was measured.

Comparative Example 3
A varnish was prepared in the same manner as in Example 1 except that only the above DiPhNB (10.0 g, 3.1 × 10 ⁻² mol) was used so that the exo content was 20%. Attempts were made to fabricate and create a waveguide. In addition, it was 387 second when the gelation time in 85 degreeC of the used varnish was measured.

  The graph which plotted each gelation time with respect to exo body content rate about Example 1 and 2 and Comparative Examples 1-3 is shown in FIG. When 100% exo-diPhNB was used, the gelation time was only 30 seconds, and it was confirmed that the faster curability increases as the exo content increases. Only by selectively synthesizing the exo form according to the present invention, such an effect can be exhibited to the maximum extent. Further, it is expected that the amount of the curing catalyst (Pd1206, DANFABA, Rhodorsil) added can be reduced as the exo form content increases. Since light scattering can be suppressed by reducing the transition metal Pd, the propagation loss of the optical waveguide obtained from the cured film is expected to be small. Furthermore, it is expected that light absorption can be reduced by reducing DANFABA and Rhodorsil, and further improvement in propagation loss of the optical waveguide is possible. Moreover, since the obtained film is so hard that a exo body content rate is high, it is anticipated that heat resistance will also become high.

  The photosensitive composition according to the present invention can be advantageously applied to the production of an optical waveguide as described above, taking advantage of the ability to provide a polynorbornene having a functional substituent by a bulk polymerization method. Further, the photosensitive composition according to the present invention can be advantageously applied as a material for producing a volume hologram recording medium for recording interference fringes by utilizing the refractive index difference in the layer.

Claims (19)

  A photoacid generator, a norbornene monomer having a leaving group capable of leaving at least a part of the molecular structure by the action of a proton released from the photoacid generator, and a catalyst for addition polymerization of the norbornene monomer The exo-form norbornene-based monomer having the leaving group at the exo position is present in excess of the endo-form norbornene-based monomer having the leaving group at the endo position. A photosensitive composition.   The photosensitive composition according to claim 1, wherein the norbornene-based monomer substantially consists of the exo-form norbornene-based monomer. The photosensitive composition according to claim 1, wherein the norbornene-based monomer is represented by the following structural formula (I).

(Wherein R ^{1 to} R ⁴ each independently represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a functional substituent, at least one of which represents the leaving group, and m represents an integer of 0 to 5.)   The photosensitive group according to claim 1, wherein the leaving group has at least one selected from the group consisting of an —O— structure, an —Si—aryl structure, and an —O—Si— structure. Sex composition.   The photosensitive composition according to claim 1, wherein the leaving group has an —O—Si-diphenyl structure.   The photosensitive composition according to claim 5, wherein the norbornene-based monomer is diphenylmethylnorbornenemethoxysilane or diphenylmethylnorborneneethoxysilane. The said catalyst is a photosensitive composition of any one of Claims 1-6 containing the compound represented by a following formula (Ia).
(E (R) ₃ ) ₂ Pd (Q) ₂ (Ia)
In the above formula, E (R) ₃ represents a neutral electron donor ligand of Group 15, E represents an element selected from Group 15 of the periodic table, and R represents a hydrogen atom or an isotope thereof. Or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate. The said catalyst is a photosensitive composition of any one of Claims 1-7 containing the compound represented by a following formula (Ib).
[(E (R) ₃ ) _a Pd (Q) (LB) _b ] _p [WCA] _r (Ib)
In the above formula, E (R) ₃ represents a neutral electron donor ligand of Group 15, E represents an element selected from Group 15 of the periodic table, and R represents a hydrogen atom or an isotope thereof. Or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate, LB represents a Lewis base, and WCA represents a weakly coordinating anion. , A represents an integer of 1 to 3, b represents an integer of 0 to 2, the sum of a and b is 1 to 3, p and r represent the charges of the palladium cation and the weakly coordinated anion. Represents a number to balance.   Furthermore, the photosensitive composition of any one of Claims 1-8 containing another norbornene-type monomer which can be bulk-polymerized with the said norbornene-type monomer.   Furthermore, the photosensitive composition of any one of Claims 1-9 containing the polynorbornene for viscosity adjustment.   Furthermore, the photosensitive composition of any one of Claims 1-10 containing a solvent.   Furthermore, the photosensitive composition of any one of Claims 1-11 containing the oligomer which has a monomer which has an oxetanyl group, and / or an oxetanyl group.   The optical waveguide comprised by the hardened | cured material of the photosensitive composition of any one of Claims 1-12.   An optical wiring comprising the optical waveguide according to claim 13.   An opto-electric hybrid board comprising electrical wiring and the optical wiring according to claim 14.   An electronic apparatus comprising the optical waveguide according to claim 13.   A method for forming an optical waveguide, comprising: forming a thin film of the photosensitive composition according to claim 1; and heating the thin film to subject the norbornene monomer to addition polymerization.   The method according to claim 17, wherein the addition polymerization is carried out by bulk polymerization.   Furthermore, the method of Claim 17 or 18 including the process of reducing the refractive index of the said irradiation area | region by irradiating a part of thin film after the said addition polymerization with an ultraviolet light.

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