JP3867409B2 - Manufacturing method of optical waveguide - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention provides an optical circuit used in the fields of optical communication, optical information processing, and the like.Manufacturing method of optical waveguideAbout.
[0002]
[Prior art]
In the multimedia era, transmission systems that use light as a transmission medium have become public communication networks, LANs (local area networks), and FAs (factory automation) in response to demands for large capacity and high speed information processing in optical communication systems and computers. ), Being used for interconnects between computers, home wiring, and the like.
An optical waveguide is a basic component in optical devices, an optical integrated circuit (OEIC), an optical integrated circuit (optical IC), and the like for realizing large-capacity information transmission such as movies and moving images, optical computers, and the like. And since this optical waveguide has a great demand, in recent years, a product with particularly high performance and low cost has been demanded.
[0003]
Conventionally, polymer-based optical waveguides and quartz-based optical waveguides are known as optical waveguides. Examples of methods for producing polymer-based optical waveguides include, for example, Japanese Patent Laid-Open Nos. 6-273363 and 7-159630. A method for producing an optical waveguide using an ultraviolet curable resin is exemplified. This polymer-based optical waveguide has an advantage that it can be manufactured easily and at low cost by using means such as photolithography, compared with a quartz-based optical waveguide. There is a drawback that the loss is large and the heat resistance is low, and there is a problem that the waveguide loss is large especially for light with a wavelength of 650 to 1600 nm used for communication.
[0004]
On the other hand, as a method for manufacturing a quartz-based waveguide, a lower clad layer made of a glass film is formed on a silicon substrate by means of a flame deposition method (FHD), a CVD method or the like, and the lower clad layer is refracted on the lower clad layer. There is a method in which inorganic thin films having different rates are formed, a core portion is formed by patterning the thin film using reactive ion etching (RIE), and then an upper cladding layer is formed by flame deposition. Representative.
However, this method requires a long time for manufacturing because the implementation of each step is considerably complicated and a vitrification step of heating to a temperature of 1000 ° C. or higher is necessary to transparentize each constituent layer. Cost and high cost.
[0005]
On the other hand, Japanese Patent Application Laid-Open No. 6-250036 exemplifies a method of manufacturing a silica-based optical waveguide by forming an inorganic thin film using a so-called sol-gel method. In this method, a thin film can be formed in a short time at a low temperature as compared with the flame deposition method, but the point that a long time is required for a process such as reactive ion etching is the same. It will be expensive.
As described above, according to the conventional method for producing a silica-based optical waveguide, an optical waveguide having low waveguide loss and excellent heat resistance can be obtained, but the production process is complicated, inefficient, and costly. There was a problem that it was expensive.
[0006]
[Problems to be solved by the invention]
  The present invention has been made in the background as described above. An optical waveguide having a low waveguide loss with respect to light ranging from the visible region to the infrared region and excellent in heat resistance can be obtained in a short time and with a simple process. Can be manufactured inThe purpose is to provide.
[0007]
[Means for Solving the Problems]
  Said subject is solved by the following manufacturing method.
  That is, the optical waveguide manufacturing method of the present invention includes a substrate, a lower clad layer formed on the substrate, a core portion formed on the lower clad layer, and formed on the core portion and the lower clad layer. A method of manufacturing an optical waveguide comprising an upper clad layer formed,
  At least one of the lower clad layer, the core portion, and the upper clad layer is formed by means including applying a radiation curable composition containing the following components (A) to (C) and curing the composition by irradiation with radiation. It is characterized by that.
(A) At least one compound selected from the group consisting of a hydrolyzate of a hydrolyzable silane compound represented by the general formula (1) and a condensate of the hydrolyzate
  General formula (1) (R¹)_pSi (X)_4-p
[In the formula, R¹Is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3. ]
(B) Photoacid generator
(C)It is at least one compound selected from the group consisting of carboxylic acid esters, acetals (including ketals) and carboxylic anhydrides, and has a boiling point in the range of 40 to 200 ° C. at normal pressure.Dehydrating agent made of organic compounds
[0008]
In the above method, the core portion is formed by irradiating the thin film obtained by applying the radiation curable composition for forming the core portion according to a predetermined pattern and then removing the unexposed portion. It is preferable to do.
Further, the radiation curable composition for forming the core portion is a radiation curable composition in which the refractive index of the core portion formed thereby is higher than the refractive indexes of the lower cladding layer and the upper cladding layer. .
[0009]
  In the above method,R in the general formula (1) ¹ Preferably has a radically polymerizable group or a cationically polymerizable group.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described.
FIG. 1 is a cross-sectional view illustrating the basic structure of an optical waveguide manufactured by the method of the present invention. As shown in FIG. 1, the optical waveguide 10 includes a substrate 12 extending in a direction perpendicular to the paper surface, a lower cladding layer 13 formed on the surface of the substrate 12, and a lower cladding layer 13 formed on the lower cladding layer 13. A core portion 15 having a specific width and an upper clad layer 17 formed on the lower clad layer 13 including the core portion 15 are formed. The core portion 15 is entirely formed of the lower clad layer 13. The upper cladding layer 17 is buried in the stack.
[0012]
According to a preferred embodiment of the method of the present invention, the optical waveguide 10 is manufactured as follows. That is, as shown in FIG. 2A, a substrate 12 having a flat surface is prepared. The substrate 12 is not particularly limited, and a silicon substrate, a glass substrate, or the like can be used.
A lower clad layer 13 is formed on the surface of the substrate 12. Specifically, as shown in FIG. 2 (b), a lower clad layer forming composition (hereinafter referred to as “lower layer composition”) made of a radiation curable composition described later is applied to the surface of the substrate 12. The lower layer thin film is formed by drying or pre-baking, and the lower layer thin film is cured by irradiating the lower layer thin film to form the lower cladding layer 13.
[0013]
Next, as shown in FIG. 2C, a core-forming composition (hereinafter referred to as “core composition”) made of a radiation-curable composition, which will be described later, is applied onto the lower cladding layer 13. The core thin film 14 is formed by drying or further pre-baking. After that, as shown in FIG. 2 (d), the upper surface of the core thin film 14 is irradiated with radiation according to a predetermined pattern, for example, through a photomask 18 having a mask hole of a predetermined pattern. As a result, the portion irradiated with the radiation is cured. By removing other uncured portions, as shown in FIG. 2 (e), a patterned cured film is formed on the lower cladding layer 13. A core portion 15 is formed.
[0014]
An upper clad layer forming composition (hereinafter referred to as “upper layer composition”) made of a radiation curable composition described later is applied to the surface of the lower clad layer 13 on which the core portion 15 is formed, and dried. Alternatively, an upper thin film is formed by pre-baking, and the upper thin film is irradiated with radiation to be cured, thereby forming the upper clad layer 17 as shown in FIG. Is done.
[0015]
In the optical waveguide obtained as described above, the thicknesses of the lower cladding layer 13, the upper cladding layer 17 and the core portion 15 are not particularly limited, but the thickness of the lower cladding layer 13 is 3 to 50 μm, and the core portion 15 Is preferably 3 to 20 μm, and the upper cladding layer 17 is preferably 3 to 50 μm in thickness. Although the width | variety of the core part 15 is not specifically limited, For example, it is the range of 1-50 micrometers.
The refractive index of the core portion 15 needs to be higher than the refractive indexes of the lower cladding layer 13 and the upper cladding layer 17, and the refractive index of the core portion 15 in the actual optical waveguide is light with a wavelength of 1300 to 1600 nm. The refractive index of the lower cladding layer 13 and the upper cladding layer 17 is preferably 1.400 to 1.648, and the refractive index of the core portion is the refractive index of both cladding layers. Is preferably larger in the range of 0.002 to 0.5.
[0016]
In a specific embodiment of the present invention, the lower clad layer, the core portion, and the upper clad layer are all radiation curable compositions for forming these layers, that is, a lower layer composition, a core composition, and The upper layer composition is applied, and the formed coating film is preferably dried or prebaked as necessary to form a thin film, and the thin film is preferably cured through irradiation.
[0017]
  In the present invention, the composition for the lower layer, the composition for the core, and the composition for the upper layerAs at least one ofA radiation curable composition containing the following components (A) to (C):Used.
(A) represented by general formula (1)Hydrolyzate of hydrolyzable silane compound and hydrolyzateAt least one compound selected from the group consisting of condensates of
  General formula (1) (R¹)_pSi (X)_4-p
[In the formula, R¹Is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3. ]
(B) Photoacid generator
(C)Made of organic compoundsDehydrating agent
[0018]
  Hereinafter, this radiation-curable composition will be described.
(1) (A) component
  The component (A) is a main component of the radiation curable composition and is represented by the general formula (1).Hydrolyzate of hydrolyzable silane compound and hydrolyzateAt least one compound selected from the group consisting of condensates of
[0019]
Here, the hydrolyzable group represented by X is usually hydrolyzed by heating within the temperature range of room temperature (25 ° C.) to 100 ° C. in the presence of non-catalyst and excess water, thereby producing a silanol group. Or a group capable of forming a siloxane condensate. The subscript p in the general formula (1) is an integer of 0 to 3, more preferably an integer of 0 to 2, and particularly preferably 1.
However, in the hydrolyzate of the hydrolyzable silane compound represented by the general formula (1), a partially unhydrolyzed hydrolyzable group may remain. In that case, the hydrolyzable silane compound and the hydrolyzate It becomes a mixture with things.
The hydrolyzate of a hydrolyzable silane compound means not only a compound in which an alkoxy group is changed to a silanol group by a hydrolysis reaction, but also a partial condensate in which some silanol groups are condensed with each other. .
Furthermore, the hydrolyzable silane compound is not necessarily hydrolyzed at the time of blending the radiation curable composition, and at least a part of the hydrolyzable group is hydrolyzed at the stage of irradiation with radiation. That's fine. That is, in the radiation curable composition, when the hydrolyzable silane compound is used without being previously hydrolyzed, water is added in advance to hydrolyze the hydrolyzable group, thereby generating a silanol group. Thus, the radiation curable composition can be radiation cured.
[0020]
[Organic group R¹]
Organic group R in general formula (1)¹Can be selected from monovalent organic groups that are non-hydrolyzable.
As such a non-hydrolyzable organic group, a non-polymerizable organic group and / or a polymerizable organic group can be selected. Organic group R¹The non-hydrolyzable in means that it is a property that exists stably as it is under the condition that the hydrolyzable group X is hydrolyzed.
[0021]
Here, non-polymerizable organic group R¹Examples thereof include an alkyl group, an aryl group, and an aralkyl group. These may be linear, branched, cyclic, or combinations thereof.
More specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, an octyl group, and a deuterated alkyl group or a halogenated alkyl group. Of these alkyl groups, a methyl group is more preferred.
[0022]
Non-polymerizable organic group R¹Specific examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, and a deuterated aryl group or a halogenated aryl group. Of these, more preferred is a phenyl group.
Further, non-polymerizable organic group R¹Specific examples of the aralkyl group in include a benzyl group and a phenylethyl group. Of these, a benzyl group is more preferable.
[0023]
Further, non-polymerizable organic group R¹Is preferably a structural unit containing a heteroatom. Examples of such a structural unit include ether, ester, sulfide and the like. Moreover, when it contains a hetero atom, it is preferable that it is non-basic.
[0024]
In addition, polymerizable organic group R¹Is preferably an organic group having a radical polymerizable functional group and / or a cationic polymerizable functional group in the molecule. By introducing such a functional group, the radiation curable composition can be cured more effectively by using radical polymerization or cationic polymerization together.
[0025]
In addition, polymerizable organic group R¹Of the radical polymerizable functional group and the cationic polymerizable functional group, a cationic polymerizable functional group is more preferable. This is because the photoacid generator can cause not only a curing reaction in a silanol group but also a curing reaction in a cationic polymerizable functional group at the same time.
[0026]
Organic group R having a radical polymerizable functional group¹Examples of the organic group include an organic group having an olefin group, an organic group having (meth) acryloxy, an organic group having a styryl group, and an organic group having a vinyl ether.
And as a more specific olefin group, a vinyl group, a propenyl group, a butadienyl group, etc. are mentioned. Of these, a vinyl group is more preferable.
Examples of organic groups having (meth) acryloxy include (meth) acryloxymethyl and (meth) acryloxypropyl.
Examples of the organic group having a styryl group include styryl, styrylethyl, styrylpropyl, and the like.
Furthermore, examples of the organic group having vinyl ether include vinyloxyethyl, vinyloxypropyl, vinyloxybutyl, vinyloxyoctyl, vinyloxycyclohexyl, vinyloxyphenyl and the like.
[0027]
Further, an organic group R having a cationic polymerizable functional group¹Examples thereof include an organic group having a cyclic ether structure and an organic group having a vinyl ether.
More preferably, it is an organic group having a cyclic ether structure. Examples of such a cyclic ether group include a 3- to 6-membered cyclic ether structure having a linear or cyclic structure, and more specifically a structure containing an epoxy group, an oxetane group, tetrahydrofuran, and a pyran unit. Of these cyclic ether groups, more preferred are cyclic ether structures having a 4-membered ring or less such as an epoxy group and an oxetane group.
[0028]
Specific examples of the organic group having a cyclic ether structure include glycidylpropyl, epoxidized cyclohexylethyl, methyl oxetanyl methoxypropyl, ethyl oxetanyl methoxypropyl, and the like. Examples of the organic group having vinyl ether include vinyloxyethyl, vinyloxypropyl, vinyloxybutyl, vinyloxyoctyl, vinyloxycyclohexyl, vinyloxyphenyl and the like.
[0029]
[Hydrolyzable group X]
As hydrolyzable group X in General formula (1), a hydrogen atom, a C1-C12 alkoxy group, a halogen atom, an amino group, an acyloxy group, etc. are mentioned. Here, specific examples of the preferable alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, phenoxybenzyloxy group, methoxyethoxy group, acetoxyethoxy group, 2- (meth) acrylic group. Loxyethoxy group, 3- (meth) acryloxypropoxy group, 4- (meth) acryloxybutoxy group,
Alternatively, an epoxy group-containing alkoxy group such as a glycidyloxy group or an epoxidized cyclohexylethoxy group,
Oxetane group-containing alkoxy groups such as methyl oxetane methoxy and ethyl oxetane methoxy,
Examples include an alkoxy group having a 6-membered ring ether group such as oxacyclohexyloxy.
Moreover, a methoxy group and an ethoxy group are more preferable among the C1-C12 alkoxy groups mentioned above. Since these alkoxy groups are easily hydrolyzed to form silanol groups, a radiation curing reaction can be caused stably.
[0030]
Preferred halogen atoms include fluorine, chlorine, bromine and iodine.
However, when using a hydrolyzable silane compound containing a halogen atom as a hydrolyzable group in this way, care must be taken not to reduce the storage stability of the radiation curable composition. That is, depending on the amount of hydrogen halide produced by hydrolysis, such hydrogen halide is removed by operations such as neutralization and distillation so as not to affect the storage stability of the radiation-curable composition. It is preferable to make it.
[0031]
Preferred amino groups include amino group, dimethylamino group, diethylamino group, butylamino group, dibutylamino group, phenylamino group, diphenylamino group and the like.
However, when an amino group is used as the hydrolyzable group, amines are generated by hydrolysis. Therefore, it is preferable to remove such by-product amines before final preparation of the radiation curable composition so as not to affect the storage stability of the radiation curable composition.
[0032]
Moreover, as a preferable acyloxy group, an acetoxy group, a butyroyloxy group, etc. can be mentioned.
[0033]
[Specific examples of hydrolyzable silane compounds]
Next, a specific example of the hydrolyzable silane compound represented by the formula (1) (sometimes simply referred to as a silane compound) will be described.
First, non-polymerizable organic group R¹As the silane compound having, there are four types such as tetrachlorosilane, tetraaminosilane, tetraacetoxysilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraphenoxysilane, tetrabenzyloxysilane, trimethoxysilane, triethoxysilane, etc. Examples thereof include silane compounds substituted with a hydrolyzable group.
[0034]
Similarly, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, butyltrimethoxysilane, pentafluorophenyltrimethoxy Silane, phenyltrimethoxysilane, d_ThreeExamples include silane compounds substituted with three hydrolyzable groups such as methyltrimethoxysilane, nonafluorobutylethyltrimethoxysilane, and trifluoromethyltrimethoxysilane.
[0035]
Similarly, silane compounds substituted with two hydrolyzable groups such as dimethyldichlorosilane, dimethyldiaminosilane, dimethyldiacetoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, dibutyldimethoxysilane, and the like, and trimethylchlorosilane, hexa Mention may be made of silane compounds substituted with one hydrolyzable group such as methyldisilazane, trimethylsilane, tributylsilane, trimethylmethoxysilane, tributylethoxysilane.
[0036]
Among these, preferable examples of the hydrolyzable silane compound include methylalkoxysilanes such as methyltrimethoxysilane and methyltriethoxysilane, and tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane.
[0037]
  Also,Polymerizable organic groupAs a silane compound havingNon-hydrolyzable organic group R ¹ Polymerizable organic groupA silane compound containing,Hydrolyzable organic group X and polymerizable organic groupAny of the silane compounds having can be used.
[0038]
  here,Non-hydrolyzable organic group R ¹ Polymerizable organic groupExamples of silane compounds containing methacrylic acid include (meth) acryloxypropyltrimethoxysilane, (meth) acryloxypropyltriethoxysilane, (meth) acryloxypropylmethyldimethoxysilane, (meth) acryloxypropyltrichlorosilane, bis (methacryloxypropyl) ) (Meth) acryloxysilane compounds such as dimethoxysilane,
Vinylsilane compounds such as vinyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, divinyldimethoxysilane, divinyldiethoxysilane,
Epoxy silane compounds such as glycidyloxytrimethoxysilane, bis (glycidyloxy) dimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane,
Oxetanesilane compounds such as 3- (3-methyl-3-oxetanemethoxy) propyltrimethoxysilane and 3- (3-ethyl-3-oxetanemethoxy) propyltriethoxysilane;
Examples thereof include silane compounds having a 6-membered ring ether structure such as oxacyclohexyltrimethoxysilane and oxacyclohexyltriethoxysilane. These can be used alone or in combination of two or more.
[0039]
  Also,Hydrolyzable organic group X and polymerizable organic groupExamples of silane compounds that contain tetra (meth) acryloxysilane, tetrakis [2- (meth) acryloxyethoxy] silane, tetraglycidyloxysilane, tetrakis (2-vinyloxyethoxy) silane, tetrakis (2- Vinyloxybutoxy) silane, tetrakis (3-methyl-3-oxetanemethoxy) silane, methyltri (meth) acryloxysilane, methyl [2- (meth) acryloxyethoxy] silane, methyl-triglycidyloxysilane, methyltris (3 -Methyl-3-oxetanemethoxy) silane. These can be used alone or in combination of two or more.
[0040]
  Also,Polymerizable organic groupOf the silane compounds havingNon-hydrolyzable organic group R ¹ Polymerizable organic groupA silane compound having a cationically polymerizable organic group is more preferable.
  Specific examples include glycidyloxypropyltrimethoxysilane, glycidyloxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl). Ethyltriethoxysilane, 3- (3-methyl-3-oxetanemethoxy) propyltrimethoxysilane, 3- (3-ethyl-3-oxetanemethoxy) propyltrimethoxysilane, 3- (3-methyl-3-oxetanemethoxy) ) Propyltriethoxysilane, 3- (3-ethyl-3-oxetanemethoxy) propyltrimethoxysilane, and the like.
[0041]
[Examples of obtaining hydrolyzable silane compounds]
The hydrolyzable silane compound described above can be synthesized by a known method. For example, Pure Appl. Chem. A34 (11), 2335, 1997, Eur. Polym. J. et al. Vol. 33, no. 7, 1021, 1997, a compound having an olefin group is subjected to hydrosilylation using a trialkoxysilane as a transition metal complex or a radical generator as a catalyst to thereby generate alkoxy having various functional groups. Silanes can be produced.
[0042]
Some of these hydrolyzable silane compounds are commercially available and can be easily obtained. For example, Nippon Unicar Co., Ltd. A-151, A-171, A-172, A-174, Y-9936, AZ-6167, AZ-6134, A-186, A-187, MAC-2101, MAC -2301, FZ-3704, AZ-6200, A-162, A-163, AZ-6171, A-137, A-153, A-1230, and, for example, SZ-6030 manufactured by Toray Dow Corning Silicone Co., Ltd. SH-6040, SZ-6070, SZ-6072, SZ-6075, SZ-6079, SZ-6300, PRX11, PRX19, PRX24, AY43-154M and the like.
[0043]
[Hydrolysis conditions of hydrolyzable silane compound]
The conditions for hydrolyzing or condensing the above-mentioned silane compound are not particularly limited, but it is preferable to carry out the steps 1) to 3) shown below as an example.
[0044]
1) A hydrolyzable silane compound represented by the general formula (1) and a predetermined amount of water are accommodated in a container equipped with a stirrer.
2) Next, the organic solvent is further accommodated in the container while adjusting the viscosity of the solution to obtain a mixed solution.
3) The obtained mixed solution is heated and stirred for 1 to 24 hours in an air atmosphere at a temperature from 0 ° C. to the boiling point of the organic solvent or hydrolyzable silane compound. During heating and stirring, it is also preferable to concentrate the mixed solution by distillation or replace the solvent as necessary.
[0045]
(2) Photoacid generator
[Definition]
The photoacid generator of component (B) in the radiation curable composition releases an acidic active substance capable of radiation curing (crosslinking) the hydrolyzable silane compound as component (A) by irradiating with radiation. Is defined as a compound capable of
[0046]
Examples of radiation for decomposing the photoacid generator to generate cations include visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, γ-rays, etc., but have a certain energy level. In addition, ultraviolet rays are preferable because a high curing rate can be obtained and the irradiation apparatus is relatively inexpensive and may be small.
[0047]
Moreover, it is also preferable to use together the radical generator mentioned later with a photo-acid generator. The radical which is a neutral active substance does not promote the condensation reaction of the silanol group, but when the radical (A) component has a radical polymerizable functional group, the polymerization of the functional group may be promoted. it can. Therefore, the radiation curable composition can be cured more efficiently.
[0048]
[Types of photoacid generator]
Photoacid generators include onium salts having a structure represented by the general formula (2) (first group of compounds) and sulfonic acid derivatives having a structure represented by the general formula (3) (second group of compounds). ).
[0049]
General formula (2) [R² _aR^Three _bR^Four _cR^Five _dW]^{+ m} [MZ_{m + n}]^-m
[Wherein the cation is an onium ion, W is S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl, or —N≡N, and R², R^Three, R^FourAnd R^FiveAre the same or different organic groups, a, b, c and d are each an integer of 0 to 3, and the value of (a + b + c + d) is equal to the valence of W. M is a halide complex [MZ_{m + n}], For example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, and Co. Z is, for example, a halogen atom or an aryl group such as F, Cl, Br, etc., m is the net charge of the halide complex ion, and n is the valence of M. ]
[0050]
General formula (3) Q_S-[S (= O)₂-R⁶]_t
[Wherein Q is a monovalent or divalent organic group, R⁶Is a monovalent organic group having 1 to 12 carbon atoms, the subscript s is 0 or 1, and the subscript t is 1 or 2. ]
[0051]
First, an onium salt that is a compound of the first group is a compound that can release an acidic active substance by receiving light.
Here, the anion [MZ in the general formula (2)_{m + n}As a specific example of tetrafluoroborate (BF_Four ^-), Hexafluorophosphate (PF)₆ ^-), Hexafluoroantimonate (SbF)₆ ^-), Hexafluoroarsenate (AsF)₆ ^-), Hexachloroantimonate (SbCl₆ ^-), Tetraphenylborate, tetrakis (trifluoromethylphenyl) borate, tetrakis (pentafluoromethylphenyl) borate and the like.
[0052]
In addition, the anion [MZ in the general formula (2)_{m + n}] Instead of the general formula [MZ_nOH^-It is also preferable to use an anion represented by In addition, perchlorate ions (ClO_Four ^-), Trifluoromethanesulfonate ion (CF_ThreeSO_Three ^-), Fluorosulfonate ion (FSO)_Three ^-), Onium salts having other anions such as toluenesulfonate ion, trinitrobenzenesulfonate anion, trinitrotoluenesulfonate anion, and the like.
[0053]
Moreover, when the example of a commercial item of the compound of 1st group is shown, Sun-Aid SI-60, SI-80, SI-100, SI-60L, SI-80L, SI-100L, SI-L145, SI-L150, SI- L160, SI-L110, SI-L147 (above, Sanshin Chemical Industry Co., Ltd.), UVI-6950, UVI-6970, UVI-6974, UVI-6990 (above, Union Carbide), Adeka optomer SP -150, SP-151, SP-170, SP-171 (manufactured by Asahi Denka Kogyo Co., Ltd.), Irgacure 261 (Ciba Specialty Chemicals Co., Ltd.), CI-2481, CI-2624, CI-2623, CI-2064 (above, manufactured by Nippon Soda Co., Ltd.), CD-1010, CD-1011, CD-1012 (above, Sartomer Manufactured), DS-100, DS-101, DAM-101, DAM-102, DAM-105, DAM-201, DSM-301, NAI-100, NAI-101, NAI-105, NAI-106, SI-100 SI-101, SI-105, SI-106, PI-105, NDI-105, BENZOIN TOSYLATE, MBZ-101, MBZ-301, PYR-100, PYR-200, DNB-101, NB-101, NB- 201, BBI-101, BBI-102, BBI-103, BBI-109 (above, manufactured by Midori Chemical Co., Ltd.), PCI-061T, PCI-062T, PCI-020T, PCI-022T (above, Nippon Kayaku ( Co., Ltd.), IBPF, IBCF (manufactured by Sanwa Chemical Co., Ltd.) and the like.
[0054]
Of the compounds of the first group described above, more effective onium salts are aromatic onium salts, and particularly preferably diaryl iodonium salts represented by the following general formula (4).
Formula (4) [R⁷-Ar¹-I⁺-Ar²-R⁸] [Y^-]
[In the formula, R⁷And R⁸Are each a monovalent organic group, which may be the same or different, and R⁷And R⁸At least one of them has an alkyl group having 4 or more carbon atoms, Ar¹And Ar²Are each an aromatic group, which may be the same or different, Y^-Is a monovalent anion and is a group 3 or 5 fluoride anion of the periodic table or ClO_Four ^-, CF_Three-SO_Three ^-An anion selected from ]
[0055]
Specific examples of such diaryliodonium salts include (4-n-decyloxyphenyl) phenyliodonium hexafluoroantimonate, [4- (2-hydroxy-n-tetradecyloxy) phenyl] phenyliodonium.
Hexafluoroantimonate, [4- (2-hydroxy-n-tetradecyloxy) phenyl] phenyliodonium trifluorosulfonate, [4- (2-hydroxy-n-tetradecyloxy) phenyl] phenyliodonium hexafluorophosphate, [ 4- (2-hydroxy-n-tetradecyloxy) phenyl] phenyliodonium tetrakis (pentafluorophenyl) borate, bis (4-t-butylphenyl) iodonium hexafluoroantimonate, bis (4-t-butylphenyl) iodonium Hexafluorophosphate, bis (4-t-butylphenyl) iodonium trifluorosulfonate, bis (4-t-butylphenyl) iodonium tetrafluoroborate, bis (dodecylpheny) ) One or a combination of two or more of iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium hexafluorophosphate, bis (dodecylphenyl) iodonium trifluoromethylsulfonate, etc. Can be mentioned.
[0056]
Moreover, as a commercial item of diaryliodonium salt, for example, CD1012, manufactured by Sartomer, IBPF, IBCF, manufactured by Sanwa Chemical Co., Ltd., BBI-101, BBI-102, BBI-103 manufactured by Midori Chemical Co., Ltd., And BBI-109.
[0057]
Furthermore, the production method of the diaryl iodonium salt represented by the general formula (4) is not particularly limited. For example, J. Polymer Science: Part A: polymer Chemistry, Vol. 31, 1473-1482 (1993) ), J. Polymer Science: Part A: polymer Chemistry, Vol. 31, 1483-1491 (1993).
[0058]
Next, the second group of compounds will be described. Examples of the sulfonic acid derivative represented by the general formula (3) are disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imidosulfonates, benzoinsulfonates, 1-oxy-2-sulfonate Examples include hydroxy-3-propyl alcohol sulfonates, pyrogallol trisulfonates, and benzyl sulfonates.
In general formula (3), imide sulfonates are more preferable, and among imide sulfonates, trifluoromethyl sulfonate derivatives are more preferable.
[0059]
Specific examples of such sulfonates include diphenyl disulfone, ditosyl disulfone, bis (phenylsulfonyl) diazomethane, bis (chlorophenylsulfonyl) diazomethane, bis (xylylsulfonyl) diazomethane, phenylsulfonylbenzoyldiazomethane, bis (Cyclohexylsulfonyl) methane, 1,8-naphthalenedicarboxylic acid imide methyl sulfonate, 1,8-naphthalenedicarboxylic acid imide Tosyl sulfonate, 1,8-naphthalenedicarboxylic acid imide trifluoromethyl sulfonate, 1,8-naphthalenedicarboxylic acid imide Camphor Sulfonate, succinimide phenyl sulfonate, succinimide tosyl sulfonate, succinimide trifluoromethyl sulfonate, Succinimide camphorsulfonate, phthalimide trifluorosulfonate, cis-5-norbornene-endo-2,3-dicarboxylic acid trifluoromethylsulfonate, benzoin tosylate, 1,2-diphenyl-2-hydroxypropyl tosylate 1,2-di (4-methylmercaptophenyl) -2-hydroxypropyl tosylate, pyrogallol methylsulfonate, pyrogallol ethylsulfonate, 2,6-dinitrophenylmethyl tosylate, ortho-nitrophenylmethyl tosylate, para-nitrophenyl tosylate Can be mentioned.
[0060]
[Amount of photoacid generator added]
The content ratio of the photoacid generator in the radiation curable composition is not particularly limited, but is usually within a range of 0.1 to 15 parts by weight with respect to 100 parts by weight of component (A). Is preferred. When the addition amount of the photoacid generator is less than 0.1 parts by weight, the radiation curability tends to be lowered and a sufficient curing rate tends not to be obtained. On the other hand, when the addition amount of a photo-acid generator exceeds 15 weight part, there exists a tendency for the weather resistance and heat resistance of the hardened | cured material obtained to fall.
Therefore, from the viewpoint of better balance between radiation curability and the weather resistance of the resulting cured product, the amount of photoacid generator added is in the range of 1 to 10 parts by weight with respect to 100 parts by weight of component (A). It is more preferable to set the value within the range.
[0061]
(3) Dehydrating agent
[Definition]
The dehydrating agent in the radiation curable composition is defined as a compound that is converted into a substance other than water by a chemical reaction, or a compound that does not affect the radiation curable property and storage stability by physical adsorption or inclusion.
That is, by containing such a dehydrating agent, the conflicting characteristics of storage stability and radiation curability can be improved without impairing the weather resistance and heat resistance of the radiation curable composition. The reason for this is not necessarily clear, but the storage stability of the radiation-curable composition is improved because the dehydrating agent effectively absorbs water entering from the outside, while in the condensation reaction that is a radiation-curable reaction. It is considered that the radiation curability of the radiation curable composition is improved because the dehydrating agent effectively absorbs the generated water sequentially.
[0062]
[Types of dehydrating agents]
  Dehydrating agentAt least one selected from the group consisting of carboxylic acid esters, acetals (including ketals), and carboxylic anhydridesIt is an organic compound.These dehydrating agents exhibit an excellent dehydrating effect, and can effectively exhibit the function of the dehydrating agent with a small amount of addition.
[0063]
The carboxylic acid ester as the dehydrating agent is selected from carboxylic acid ortho ester, carboxylic acid silyl ester, and the like.
Here, preferable examples of the carboxylic acid orthoester include methyl orthoformate, ethyl orthoformate, propyl orthoformate, butyl orthoformate, methyl orthoacetate, ethyl orthoacetate, propyl orthoacetate, butyl orthoacetate, methyl orthopropionate and orthopropion. Examples include ethyl acid. Of these carboxylic acid orthoesters, orthoformate esters are particularly preferred as the dehydrating agent from the viewpoint of exhibiting a more excellent dehydrating effect and further improving storage stability and radiation curability.
Preferred carboxylic acid silyl esters include trimethylsilyl acetate, tributylsilyl acetate, trimethylsilyl formate, trimethylsilyl oxalate and the like.
[0064]
Of the carboxylic acid esters, it is more preferable to use a carboxylic acid ortho ester. Carboxylic acid orthoesters can efficiently absorb water and hydrolyze themselves. Further, the compound formed by hydrolysis of the carboxylic acid ortho ester is neutral. Therefore, the carboxylic acid ortho ester exhibits an excellent dehydration effect and can further improve storage stability and radiation curability.
[0065]
Preferred acetals include, for example, dimethyl acetal, diethyl acetal, which is a reaction product of ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, acetaldehyde, propionaldehyde, benzaldehyde and a monohydric alcohol. Examples thereof include dipropyl acetal, or acetal composed of a dihydric alcohol such as ethylene glycol and a ketone, and a ketene silyl acetal produced by a silylation reaction of a carboxylic acid ester.
[0066]
Of these acetals, acetone dimethyl acetal, acetone diethyl acetal, methyl ethyl ketone dimethyl acetal, methyl ethyl ketone diethyl acetal, cyclohexanone dimethyl acetal, and cyclohexanone diethyl acetal exhibit particularly excellent dehydration effects, and exhibit storage stability and radiation curability. From the viewpoint of further improvement, it is preferable for use as a dehydrating agent in the present invention.
[0067]
Examples of preferable carboxylic acid anhydrides include formic anhydride, acetic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, benzoic anhydride, and acetic acid benzoic anhydride. In particular, acetic anhydride and succinic anhydride are preferable because they are particularly excellent in dehydrating effect.
[0069]
[Properties of dehydrating agent]
  Next, the properties of the dehydrating agent will be described. First, the dehydrating agent is solid or liquid at normal temperature and normal pressure, and is selected from compounds that dissolve or disperse in the radiation curable composition and exhibit a dehydrating effect.
  In addition, the dehydrating agent made of an organic compound has a boiling point (under normal pressure) in the range of 40 to 200 ° C.Is.If the boiling point is a value within such a range, it can be efficiently volatilized under drying conditions of room temperature (25 ° C.) to 200 ° C. Therefore, it is easy to remove the dehydrating agent.
[0070]
[Addition amount of dehydrating agent]
Although the content rate of the dehydrating agent in the radiation curable composition is not particularly limited, it is usually set to a value in the range of 0.1 to 100 parts by weight with respect to 100 parts by weight of component (A). preferable. When the addition amount of the dehydrating agent is less than 0.1 parts by weight, the addition effect tends to be poor and the effect of improving storage stability and radiation curability tends to be low. On the other hand, when the addition amount of the dehydrating agent exceeds 100 parts by weight, the effect of improving storage stability and radiation curability tends to be saturated.
Therefore, more preferably, the addition amount of the dehydrating agent is a value within a range of 0.5 to 50 parts by weight, and more preferably within a range of 1 to 10 parts by weight with respect to 100 parts by weight of the component (A). Value.
[0071]
(4) Additives
The radiation curable composition used in the present invention includes a radical photopolymerization initiator, a photosensitizer, a reactive diluent, silica particles, an organic solvent, and the like, as long as the purpose and effect of the present invention are not impaired. Additives and the like can be further contained.
[0072]
[Radical photopolymerization initiator]
In the radiation curable composition used in the present invention, a radical photopolymerization initiator (radical generator) may be blended in combination with a photoacid generator. A radical generator is a compound that decomposes by receiving radiation such as ultraviolet rays to generate radicals, and causes radical polymerization groups to polymerize by the radicals.
[0073]
Examples of such a radical generator include acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chlorobenzophenone, 4 , 4′-diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone compound, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino- Propan-2-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2 , 6-Dimethoxybenzoy ) -2,4,4-tri-methylpentylphosphine oxide, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde Benzoin ethyl ether, benzoin propyl ether, benzophenone, benzophenone derivatives, Michler ketone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone (BTTB), and the like. In addition, this radical generator can also be used individually by 1 type, or can be used in combination of 2 or more type.
[0074]
[Photosensitizer]
In the radiation curable composition used in the present invention, a photosensitizer may be blended in combination with a photoacid generator. A photosensitizer is a compound that absorbs energy rays such as light and improves the sensitivity of the photoacid generator.
[0075]
Such photosensitizers include thioxanthone, diethylthioxanthone and thioxanthone derivatives; anthraquinone, bromoanthraquinone and anthraquinone derivatives; anthracene, bromoanthracene and anthracene derivatives; perylene and perylene derivatives; xanthene, thioxanthene and thioxanthene derivatives. Derivatives such as coumarin and ketocoumarin. Among these photosensitizers, more preferred compounds are diethylthioxanthone and bromoanthracene.
[0076]
(Reactive diluent)
By adding (compounding) a reactive diluent to the radiation curable composition used in the present invention, curing shrinkage of the resulting cured film can be reduced, or the mechanical strength of the cured film can be controlled. . Further, when a radical polymerizable reactive diluent is used, the photoreactivity of the radiation curable composition can be adjusted by further adding a radical generator. In addition, when a cationic polymerizable reactive diluent is used, photoreactivity and mechanical properties can be adjusted.
[0077]
[Types of reactive diluents]
As the reactive diluent, it is preferable to blend a cationically polymerizable monomer and / or an ethylenically unsaturated monomer.
Here, the cationic polymerizable monomer that is a reactive diluent is defined as an organic compound that undergoes a polymerization reaction or a crosslinking reaction when irradiated with light in the presence of a photoacid generator. Therefore, for example, epoxy compounds, oxetane compounds, oxolane compounds, cyclic acetal compounds, cyclic lactone compounds, thiirane compounds, thietane compounds, vinyl ether compounds, spiro orthoester compounds that are reaction products of epoxy compounds and lactones, ethylenically unsaturated Examples thereof include a compound, a cyclic ether compound, a cyclic thioether compound, and a vinyl compound. These cationic polymerizable monomers can be used singly or in combination of two or more.
[0078]
Moreover, the epoxy compound as the above-mentioned cationic polymerizable monomer includes, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, bromine Bisphenol S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxy Cyclohexane carboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3 , 4-epoxycyclohexylmethyl) adipate, vinylcyclohexylene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4 '-Epoxy-6'-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylene bis (3,4- Epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6-hexanedi Diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether; one or two aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin Polyglycidyl ethers of polyether polyols obtained by adding the above alkylene oxides; diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; phenol, cresol, butylphenol or the like Monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides; glycidyl esters of higher fatty acids; Carboxymethyl soybean oil; butyl epoxy stearate, epoxy stearic octyl, epoxidized linseed oil; can be exemplified epoxidated polybutadiene.
[0079]
Other cationic polymerizable monomers include trimethylene oxide, 3,3-dimethyloxetane, 3,3-dichloromethyloxetane, 3-ethyl-3-phenoxymethyloxetane, bis (3-ethyl-3-methyloxy). ) Oxetanes such as butane; oxolanes such as tetrahydrofuran and 2,3-dimethyltetrahydrofuran; cyclic acetals such as trioxane, 1,3-dioxolane and 1,3,6-trioxanecyclooctane; β-propiolactone, ε -Cyclic lactones such as caprolactone; thiiranes such as ethylene sulfide, 1,2-propylene sulfide, thioepichlorohydrin; thietanes such as 3,3-dimethylthietane; ethylene glycol divinyl ether, triethylene glycol divinyl ether , Trime Vinyl ethers such as tyrolpropane trivinyl ether; spiro orthoesters obtained by reaction of an epoxy compound with a lactone; ethylenically unsaturated compounds such as vinylcyclohexane, isobutylene, polybutadiene; and derivatives of the above compounds Can do.
[0080]
Among the cationic polymerizable monomers described above, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis (3,3 4-epoxycyclohexylmethyl) adipate, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol di Glycidyl ether and polypropylene glycol diglycidyl ether are preferred.
[0081]
Particularly preferred cationically polymerizable monomers include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, and two or more per molecule. An epoxy compound having an alicyclic epoxy group.
[0082]
The cationic polymerizable monomers described above are UVR-6100, UVR-6105, UVR-6110, UVR-6128, UVR-6200, UVR-6216 (manufactured by Union Carbide), Celoxide 2021, Celoxide 2021P, Celoxide 2081. , Celoxide 2083, Celoxide 2085, Celoxide 2000, Celoxide 3000, Glycidol, AOEX24, Cyclomer A200, Cyclomer M100, Epolide GT-300, Epolide GT-301, Epolide GT-302, Epolide GT-400, Epolide 401, Epolide 403 (Daicel Chemical Industries, Ltd.), Epicoat 828, Epicoat 812, Epicoat 1031, Epicoat 872, Epicoat CT50 (Made by Yuka Shell Co., Ltd.), KRM-2100, KRM-2110, KRM-2199, KRM-2400, KRM-2410, KRM-2408, KRM-2490, KRM-2200, KRM-2720, KRM- 2750 (above, manufactured by Asahi Denka Kogyo Co., Ltd.), Rapi-Cure DVE-3, CHVE, PEPC (above, made by ISP), VECTOMER 2010, 2020, 4010, 4020 (above, made by Allied Signal), etc. It can be easily obtained as a product.
[0083]
Next, the ethylenically unsaturated monomer as the reactive diluent will be described. Here, the ethylenically unsaturated monomer is a compound having an ethylenically unsaturated bond (C = C) in the molecule, a monofunctional monomer having one ethylenically unsaturated bond in one molecule, and one molecule It can be defined as a polyfunctional monomer having two or more ethylenically unsaturated bonds therein.
[0084]
Therefore, examples of the monofunctional monomer that is an ethylenically unsaturated monomer include (meth) acryloylmorpholine, 7-amino-3,7-dimethyloctyl (meth) acrylate, isobutoxymethyl (meth) acrylamide, and isobornyloxy. Ethyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl diethylene glycol (meth) acrylate, t-octyl (meth) acrylamide, diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylamino Ethyl (meth) acrylate, lauryl (meth) acrylate, dicyclopentadiene (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopente (Meth) acrylate, N, N-dimethyl (meth) acrylamide tetrachlorophenyl (meth) acrylate, 2-tetrachlorophenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, tetrabromophenyl (meth) acrylate, 2 -Tetrabromophenoxyethyl (meth) acrylate, 2-trichlorophenoxyethyl (meth) acrylate, tribromophenyl (meth) acrylate, 2-tribromophenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrylate, vinylcaprolactam, N-vinylpyrrolidone, phenoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, pentachloropheny Examples include (meth) acrylate, pentabromophenyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, bornyl (meth) acrylate, and methyltriethylene diglycol (meth) acrylate. .
[0085]
Among these acrylates, acrylates that do not contain an amide or amine structure are preferable from the viewpoint of not reducing radiation curability, and acrylates that do not contain an aromatic ring are preferable for the purpose of ensuring weather resistance.
Examples of these acrylates include isobornyl (meth) acrylate, lauryl (meth) acrylate, butoxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, bornyl (meth) acrylate, and methyltriethylene diglycol (meth) acrylate. Can be mentioned.
[0086]
Moreover, as a monofunctional monomer which is these ethylenically unsaturated monomers, for example, Aronix M-101, M-102, M-111, M-113, M-117, M-152, TO-1210 (above, Toagosei Co., Ltd.), Kayalad
TC-110S, R-564, R-128H (above, Nippon Kayaku Co., Ltd.), Biscote 192, Biscote 220, Biscote 2311HP, Biscote 2000, Biscote 2100, Biscote 2150, Biscote 8F, Biscote 17F (above, Osaka Organic) It can be easily obtained as a commercial product such as Chemical Industry Co., Ltd.).
[0087]
Examples of the polyfunctional monomer that is an ethylenically unsaturated monomer include ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, Cyclodecanediyldimethylene di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, caprolactone-modified tris (2-hydroxyethyl) isocyanate Nurate tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide (hereinafter referred to as “EO”) modified trimethylolpropane tri (meth) acrylate, Lopylene oxide (hereinafter referred to as “PO”) modified trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, both ends (meth) acrylic of bisphenol A diglycidyl ether Acid adduct, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate , Polyethylene glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) a Relate, caprolactone modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meta) ) Acrylate, EO-modified hydrogenated bisphenol A di (meth) acrylate, PO-modified hydrogenated bisphenol A di (meth) acrylate, EO-modified bisphenol F di (meth) acrylate, (meth) acrylate of phenol novolac polyglycidyl ether, etc. can do.
[0088]
Among these acrylates, acrylates that do not contain an amide or amine structure are preferable from the viewpoint of not reducing radiation curability, and acrylates that do not contain an aromatic ring are preferable for the purpose of ensuring weather resistance. Thus, for example, ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, tricyclodecanediyldimethylene di (meth) acrylate, trimethylolpropane Examples thereof include tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, and the like.
[0089]
These multifunctional monomers that are ethylenically unsaturated monomers include, for example, SA1002 (manufactured by Mitsubishi Chemical Corporation), biscoat 195, biscoat 230, biscoat 260, biscoat 215, biscoat 310, biscoat 214HP, biscoat 295, biscoat 300, Biscoat 360, Biscoat GPT, Biscoat 400, Biscoat 700, Biscoat 540, Biscoat 3000, Biscoat 3700 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Kayarad R-526, HDDA, NPGDA, TPGDA, MANDA, R-551, R-712, R-604, R-684, PET-30, GPO-303, TMPTA, THE-330, DPHA, DPHA-2H, DPHA-2C, DPHA-2I, D-310, D-330, PCA-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN-2475, T-1420, T-2020, T-2040, TPA-320, TPA-330, RP-1040, RP- 2040, R-011, R-300, R-205 (manufactured by Nippon Kayaku Co., Ltd.), Aronix M-210, M-220, M-233, M-240, M-215, M-305, M-309, M-310, M-315, M-325, M-400, M-6200, M-6400 (above, manufactured by Toagosei Co., Ltd.), light acrylate BP-4EA, BP-4PA, BP- 2EA, BP-2PA, DCP-A (above, Kyoeisha Chemical Co., Ltd.), New Frontier BPE-4, BR-42M, GX-8345 (above, Daiichi Kogyo Seiyaku Co., Ltd.) ASF-400 (above, manufactured by Nippon Steel Chemical Co., Ltd.), Lipoxy SP-1506, SP-1507, SP-1509, VR-77, SP-4010, SP-4060 (above, Showa Polymer Co., Ltd.) ), NK ester A-BPE-4 (above, Shin-Nakamura Chemical Co., Ltd.) and other commercial products can be easily obtained.
[0090]
In addition, the monofunctional monomer and the polyfunctional monomer which are ethylenically unsaturated monomers may be used singly or in combination of two or more, or a combination of at least one monofunctional monomer and at least one polyfunctional monomer. It is preferable to configure.
Examples of such a polyfunctional monomer having a polymerizable group having three or more functional groups include tri (meth) acrylate compounds, tetra (meth) acrylate compounds, penta (meth) acrylate compounds, and hexa (meth) acrylate compounds exemplified above. You can choose from. Among these, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate Is particularly preferred.
[0091]
[Silica particles]
By adding (compounding) silica particles to the radiation curable composition used in the present invention, curing shrinkage of the resulting cured film can be reduced. Here, the addition amount of the silica particles is not particularly limited, but is preferably in the range of 10 to 250 parts by weight, for example, 20 to 200 parts by weight with respect to 100 parts by weight of component (A). Furthermore, it is preferable that it is 30-150 weight part.
[0092]
Types of silica particles
The silica particles to be used may be particles having silica as a main component, and may contain other components other than silica. Examples of such components other than silica include alkali metal oxides, alkaline earth oxides, and oxides such as Ti, Zr, Al, B, Sn, and P.
The average particle diameter of the silica particles is preferably set to a value in the range of 0.001 to 20 μm, but the average particle diameter is preferably 0.001 to 0.2 μm from the point that a transparent cured film is formed. A value within the range is preferable, and a value within the range of 0.001 to 0.01 μm is more preferable.
[0093]
Further, the silica particles are set so that the difference between the refractive index of the silica particles (temperature 25 ° C., Na-D line, the same applies hereinafter) and the refractive index of the radiation curable composition is 0.02 (−) or less. Is preferably selected. By setting the difference in refractive index to such a value, the transparency of the cured film can be further increased.
The specific surface area of the silica particles is 0.1 to 3000 m.²/ G is preferably within a range of 10 to 1500 m.²A value within the range of / g.
Further, the shape of the silica particles is not particularly limited, but is preferably at least one shape selected from the group consisting of a spherical shape, a hollow shape, a porous shape, a rod shape, a plate shape, a fiber shape, and an indefinite shape. However, it is more preferable to use spherical silica particles from the viewpoint of better dispersibility.
The method of using the silica particles is not particularly limited, and for example, the silica particles can be used in a dry state, or can be used in a state dispersed in water or an organic solvent.
[0094]
Further, a dispersion of finely divided silica particles known in the industry as colloidal silica can also be used directly. And since especially high transparency is acquired, use of colloidal silica is preferable.
Here, when the dispersion solvent of colloidal silica is water, the hydrogen ion concentration is preferably a pH value in the range of 2 to 13, more preferably a value in the range of 3 to 7.
When the colloidal silica dispersion solvent is an organic solvent, methanol, isopropyl alcohol, ethylene glycol, butanol, ethylene glycol monopropyl ether, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, dimethylformamide, etc. may be used as the organic solvent. Or may be used as a mixture with an organic solvent or water compatible with these. Preferred dispersing solvents are methanol, isopropyl alcohol, methyl ethyl ketone, xylene and the like.
[0095]
Examples of commercially available silica particles include colloidal silica such as methanol silica sol, IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST- 20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL (manufactured by Nissan Chemical Industries, Ltd.) and the like. Examples of the powder silica include AEROSIL 130, AEROSIL 300, AEROSIL 380, AEROSILTT 600, AEROSILOX 50 (manufactured by Nippon Aerosil Co., Ltd.), Sildex H31, H32, H51, H52, H121, H122 (manufactured by Asahi Glass Co., Ltd.), E220A, E220 (manufactured by Nippon Silica Kogyo Co., Ltd.), SYLYSIA470 (manufactured by Fuji Silysia Co., Ltd.), SG flake (manufactured by Nippon Sheet Glass Co., Ltd.) and the like can be mentioned.
[0096]
[Organic solvent]
An organic solvent can be mix | blended with the radiation-curable composition used by this invention as needed. Such an organic solvent may be added when producing a hydrolyzate or condensate of the hydrolyzable silane compound of component (A), or may be added when blending components (A) to (C). Also good.
[0097]
Such an organic solvent can be selected within a range that does not impair the object and effect of the present invention, but is usually an organic compound having a boiling point in the range of 50 to 200 ° C. under atmospheric pressure, Organic compounds that uniformly dissolve each component are preferred.
Preferred organic solvents include alcohols such as methanol, ethanol, propanol, butanol, dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether. , Ethers such as diethylene glycol ethyl methyl ether, tetrahydrofuran and dioxane, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and methyl amyl ketone, ethyl acetate, butyl acetate, amyl acetate, ethyl lactate, ethyl 2-hydroxypropionate , Esters such as γ-butyrolactone, Emissions, toluene, aromatic hydrocarbons such as xylene. These can be used alone or in combination of two or more.
Among these, alcohols, ethers, and ketones can be mentioned as preferred organic solvents. More preferred are alcohols and ketones.
[0098]
In particular, in the present invention, it is preferable to use a spin coating method for applying the radiation curable composition, but from the viewpoint of obtaining a coating solution suitable for spin coating, an organic solvent such as ethylene glycol monoethyl ether, Glycol ethers such as propylene glycol monomethyl ether; ethylene glycol alkyl ether acetates such as ethyl cellosolve acetate, propylene glycol methyl ether acetate and propylene glycol ethyl ether acetate; esters such as ethyl lactate and ethyl 2-hydroxypropionate; diethylene glycol monomethyl Diethylene glycols such as ether, diethylene glycol dimethyl ether and diethylene glycol ethyl methyl ether; methyl isobutyl keto , 2-heptanone, cyclohexanone, it is preferable to use ketones such as methyl amyl ketone, particularly ethyl cellosolve acetate, propylene glycol methyl ether acetate, ethyl lactate, methyl isobutyl ketone and methyl amyl ketone preferred.
[0099]
[Others]
The radiation curable composition used in the present invention may further contain various additives as necessary.
Such additives include epoxy resins, acrylic resins, polyamide resins, polyamideimide resins, polyurethane resins, polybutadiene resins, polychloroprene resins, polyether resins, polyester resins, styrene-butadiene block copolymers, petroleum resins, xylenes. Examples include resins, ketone resins, cellulose resins, fluoropolymers, silicone polymers, polysulfide polymers, and other organic resins (polymers) or oligomers, or compounds in which these organic resins or oligomers are substituted with hydrolyzable silyl groups. .
Further, as other additives, polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiation assistants; leveling agents; wettability improvers; surfactants; Examples include ultraviolet absorbers; antioxidants; antistatic agents; silane coupling agents; inorganic fillers.
[0100]
[Preparation and properties of radiation curable composition]
The radiation curable composition for forming the lower clad layer, the core portion and the upper clad layer constituting the optical waveguide, that is, the lower layer composition, the core composition and the upper layer composition are each hydrolyzable as described above. A silane compound, a dehydrating agent, etc. can be manufactured by mixing and stirring according to a conventional method.
The lower layer composition, the core composition, and the upper layer composition are different from each other so that the refractive index relationship of each part finally obtained satisfies the conditions required for the optical waveguide. Although the curable composition can be used, the lower layer composition and the upper layer composition may be the same radiation-curable composition, and are usually preferably the same composition from various points of view. .
[0101]
The above-mentioned radiation curable composition forms a cured film having a different refractive index by selecting the type of the hydrolyzable silane compound and / or the hydrolyzate thereof as the component (A). Therefore, two or three types of radiation curable compositions having a difference in refractive index of an appropriate size are used, and the radiation curable composition that gives the cured film with the highest refractive index is used as the core composition. The radiation curable composition may be used as the lower layer composition and the upper layer composition.
[0102]
The viscosity of each radiation curable composition is preferably a value within the range of 5 to 10,000 cps (25 ° C.). When the viscosity exceeds these ranges, it tends to be difficult to form a uniform coating film. In addition, the viscosity of a radiation curable composition can be suitably adjusted with the compounding quantity of a reactive diluent or an organic solvent.
[0103]
As described above, in the present invention, the lower clad layer is formed on the substrate, the core portion is formed thereon, and the upper clad layer is further formed, whereby the target optical waveguide is manufactured. However, the formation of each cladding layer and core portion is common in that a thin film is formed by applying and drying the radiation curable composition, and the thin film is cured by irradiation with radiation. However, the formation of the core part is different in that the irradiation of the radiation to the thin film is performed according to a predetermined pattern, and the operation of removing the uncured part is performed.
[0104]
As a means for applying the radiation curable composition, a spin coating method, a dipping method, a spray method, a bar coating method, a roll coating method, a curtain coating method, a gravure printing method, a silk screen method, an ink jet method or the like is used. be able to. Of these, the spin coating method is particularly preferable.
In addition, various leveling agents, thixotropic agents, fillers, organic solvents, surfactants, and the like are blended as necessary in order to make the rheological properties of the radiation curable composition suitable for actual application means. be able to.
[0105]
The coating film formed by application of the radiation curable composition is dried at a temperature of 50 to 90 ° C, or further heated to 60 to 120 ° C and prebaked as necessary to form a thin film. The heating conditions for pre-baking vary depending on the type of each component of the radiation curable composition to be used, the blending ratio, and the like, but are usually about 60 to 120 ° C. for about 10 to 600 seconds.
[0106]
The formed thin film is cured by being irradiated with radiation. In the formation of the lower clad layer and the upper clad layer, the entire surface of the thin film is irradiated with radiation, and the whole is cured.
Here, visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, γ-rays, etc. can be used as radiation, but as described above, ultraviolet rays are particularly preferable. The means for irradiating ultraviolet rays is not particularly limited, and various means can be used. For example, an ultraviolet light source lamp such as a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, or an excimer lamp can be used as the light source.
The radiation applied to the thin film has a wavelength of 200 to 390 nm and an illuminance of 1 to 500 mW / cm.²The amount of irradiation is 10 to 5000 mJ / cm²It is preferable that
[0107]
Irradiation of the core thin film to form the core portion is performed according to a predetermined pattern, and then development with a developer removes unnecessary uncured portions, thereby forming the core portion. The
The method of irradiating radiation according to a predetermined pattern is not limited to a method using a photomask having a mask hole of a predetermined pattern. For example, a radiation transmission region and a radiation transmitting region according to a predetermined pattern using the same principle as a liquid crystal display device are used. A method using a means for electro-optically forming a mask image including a radiopaque region, a light guide member in which a large number of optical fibers are bundled, and an optical fiber corresponding to a predetermined pattern in the light guide member It is also possible to use a method of irradiating a radiation curable composition while scanning a convergent radiation obtained by a method of irradiating radiation, laser light or a condensing optical system such as a lens or a mirror.
[0108]
The thin film selectively cured in accordance with a predetermined pattern in this manner is developed with an appropriate organic solvent or an alkali developer using the difference in solubility between the cured portion and the uncured portion. Thus, the uncured portion can be removed and the cured portion can be left, whereby the core portion is formed.
[0109]
Here, as the developer, the organic solvent described above as used for the preparation of the radiation curable composition, or sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n -Propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, N-methylpyrrolidone, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1, An aqueous alkali solution composed of alkalis such as 8-diazabicyclo [5.4.0] -7-undecene and 1,5-diazabicyclo [4.3.0] -5-nonane can be used. The alkali water-soluble concentration is usually 0.1 to 2.5% by weight, preferably 0.2 to 0.5% by weight. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant or the like to the alkaline aqueous solution can also be used as a developer.
[0110]
The developing time is usually 30 to 180 seconds, and the developing method may be any of a liquid piling method and a dipping method. When an organic solvent is used as the developer, it is air-dried as it is, and when an alkaline aqueous solution is used, it is washed with running water for 30 to 90 seconds and air-dried with compressed air or compressed nitrogen to remove moisture on the surface. By removing, a patterned film is formed. Subsequently, patterning is performed by a heating device such as a hot plate or an oven at a predetermined temperature, for example, 150 to 250 ° C., for a predetermined time, for example, 5 to 30 minutes on the hot plate, and 30 to 90 minutes in the oven. A core portion made of a cross-linked coating is formed.
[0111]
Moreover, the cured film obtained by irradiation with radiation can be further heated as necessary. In this case, the heating is usually performed at a temperature from room temperature to a decomposition start temperature of the substrate or thin film, for example, for 5 minutes to 72 hours. Thus, the core part excellent in hardness and heat resistance can be obtained by further heating after radiation curing. This post-heating can also be performed in forming the lower cladding layer and the upper cladding layer.
As described above, the finely patterned core portion is formed in a state of being embedded in the lower clad layer and the upper clad layer stacked thereon, thereby obtaining an optical waveguide.
[0112]
Thus, according to the present invention, a specific hydrolyzable silane compound and / or a radiation curable composition containing the hydrolyzate thereof is used to form the core portion, and thus follows a predetermined pattern. By irradiating with radiation, the core part can be formed very easily and in a short time, and the obtained core part is mainly composed of polysiloxane, so that it has high transparency. The obtained optical waveguide has a small waveguide loss and a large heat resistance.
[0113]
Furthermore, the lower clad layer and the upper clad layer can also be formed by a radiation curable composition having the same composition as the composition for the core portion described above, in which case the required operation is: Since only the application of the radiation curable composition and the irradiation of radiation, as a coating apparatus, a radiation irradiation apparatus, and other processing apparatuses, those used for forming the core portion can be used as they are, and as a result, Overall, the desired optical waveguide can be manufactured very easily and at a very low cost.
[0114]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
(Preparation of polysiloxane solution)
Polysiloxane solution 1
In a vessel equipped with a stirrer, phenyltrimethoxysilane (23.3 g, 0.12 mol), methyltrimethoxysilane (61.6 g, 0.43 mol), and an electric conductivity of 8 × 10^-FiveS · cm^-1Of ion-exchanged water (15.7 g, 0.87 mol), and then hydrolyzed phenyltrimethoxysilane and methyltrimethoxysilane by heating and stirring at 60 ° C. for 6 hours. . Subsequently, methanol by-produced by hydrolysis was distilled off while adding methyl isobutyl ketone (MIBK) dropwise. And the methyl isobutyl ketone solution containing the polysiloxane which finally adjusted solid content to 40 weight% was obtained. This is designated as “polysiloxane solution 1”.
[0115]
Polysiloxane solution 2
In a vessel equipped with a stirrer, methyltrimethoxysilane (80.0 g, 0.558 mol) and an electric conductivity of 8 × 10^-FiveS · cm^-1Of ion-exchanged water (16.0 g, 0.889 mol), methyltrimethoxysilane was hydrolyzed by heating and stirring at a temperature of 60 ° C. for 6 hours. While MIBK was added dropwise, methanol by-produced by hydrolysis was distilled off. And the methyl isobutyl ketone solution containing the polysiloxane which finally adjusted solid content to 40 weight% was obtained. This is designated as “polysiloxane solution 2”.
[0116]
(Preparation of radiation curable composition)
Radiation curable composition A (core composition)
To 100 parts by weight of the polysiloxane solution 1 (solid content and solvent), 1.0 part by weight of a photoacid generator (manufactured by Sartomer, CD1012) and 3.0 parts by weight of methyl orthoformate as a dehydrating agent were added. By uniformly mixing, a radiation curable composition A was obtained.
Radiation curable composition B (lower layer composition and upper layer composition)
To 100 parts by weight of polysiloxane solution 2 (solid content and solvent), 1.0 part by weight of photoacid generator (Sartomer, CD1012) and 3.0 parts by weight of methyl orthoformate as a dehydrating agent were added, respectively. By uniformly mixing, a radiation curable composition B was obtained.
[0117]
[Example 1]
The radiation curable composition B was applied onto the surface of a silicon substrate with a spin coater and dried at 70 ° C. for 10 minutes, and then the wavelength was 365 nm and the illuminance was 200 mW / cm.²Was irradiated for 5 seconds to form a lower clad layer having a thickness of 10 μm. The refractive index of light with a wavelength of 1550 nm of this lower cladding layer was 1.423.
Next, the radiation curable composition A was applied onto the lower clad layer with a spin coater, dried at 70 ° C. for 10 minutes, and then a wavelength of 365 nm using a photomask engraved with an optical waveguide pattern having a width of 4 to 20 μm. , Illuminance 200mW / cm²The exposure was performed by irradiating the ultraviolet rays of 5 seconds. Then, this board | substrate was immersed in the developing solution which consists of ethanol, the unexposed part was melt | dissolved, and the 7-micrometer-thick core part was formed. The refractive index of light having a wavelength of 1550 nm in this core portion was 1.452.
Further, the radiation curable composition B was applied to the upper surface of the lower clad layer having the core portion with a spin coater and dried at 70 ° C. for 10 minutes, and then a wavelength of 365 nm and an illuminance of 200 mW / cm.²Was irradiated for 5 seconds to form an upper cladding layer having a thickness of 15 μm, thereby producing an optical waveguide. The refractive index of light having a wavelength of 1550 nm of the formed upper cladding layer was 1.423.
[0118]
With respect to the optical waveguide thus obtained, the waveguide loss was determined by measuring the amount of light emitted from the other end when light having a wavelength of 1300 nm was incident from one end of the waveguide. cm or less.
Further, after heating the obtained optical waveguide at 150 ° C. for 5000 hours and measuring the waveguide loss in the same manner as described above, it was 0.1 dB / cm or less, no thermal deterioration was observed, and excellent heat resistance was obtained. It was confirmed to have.
[0119]
【The invention's effect】
As described above, according to the present invention, a method for producing an optical waveguide having a low waveguide loss for light ranging from the visible region to the infrared region and excellent in heat resistance in a short time and with a simple process. In addition, an optical waveguide suitable for an optical communication system manufactured by the method is provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating the basic configuration of an optical waveguide manufactured by the method of the present invention.
FIGS. 2A to 2E are cross-sectional views for explaining an example of a method of manufacturing an optical waveguide according to the present invention in the order of steps.
[Explanation of symbols]
10 Optical waveguide
12 Substrate
13 Lower cladding layer
15 Core part
14 Thin film for core
17 Upper cladding layer
18 Photomask

Claims (4)

Production of an optical waveguide comprising a substrate, a lower clad layer formed on the substrate, a core portion formed on the lower clad layer, and an upper clad layer formed on the core portion and the lower clad layer A method,
At least one of the lower clad layer, the core portion, and the upper clad layer is formed by means including applying a radiation curable composition containing the following components (A) to (C) and curing the composition by irradiation with radiation. An optical waveguide manufacturing method characterized by the above.
(A) At least one compound selected from the group consisting of a hydrolyzate of a hydrolyzable silane compound represented by general formula (1) and a condensate of the hydrolyzate General formula (1) (R ¹ ) _p Si ( X) _4-p
[Wherein, R ¹ is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3. ]
(B) Photoacid generator (C) At least one compound selected from the group consisting of carboxylic acid esters, acetals (including ketals) and carboxylic anhydrides, and having a boiling point of 40 to 40 at normal pressure A dehydrating agent comprising an organic compound in the range of 200 ° C.   A thin film obtained by applying a radiation curable composition for forming a core part is irradiated with radiation according to a predetermined pattern, and then the unexposed part is removed to form the core part. The manufacturing method of the optical waveguide of Claim 1.   The radiation curable composition for forming the core portion is a radiation curable composition in which the refractive index of the core portion formed thereby is higher than the refractive indexes of the lower cladding layer and the upper cladding layer. The method for manufacturing an optical waveguide according to claim 1, wherein the optical waveguide is manufactured according to claim 1. The method for producing an optical waveguide according to claim 1, wherein R ¹ in the general formula (1) has a radical polymerizable group or a cationic polymerizable group.

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