JP2006063291A - Curable composition and cured film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition capable of forming a cured product utilizable for optical material, etc., for optical waveguides and excellent in heat resistance, crack resistance, a planarizing property and peeling resistance. <P>SOLUTION: The curable composition comprises the hydrolysate of a hydrolyzable silane compound represented by the general formula: (R<SP>1</SP>)<SB>p</SB>(R<SP>2</SP>)<SB>q</SB>Si(X)<SB>4-p-q</SB>[wherein R<SP>1</SP>s are 1-12C nonhydrolyzable organic groups containing a fluorine atom which are the same or different; R<SP>2</SP>is a 1-12C nonhydrolyzable organic group not containing a fluorine atom; Xs are hydrolyzable groups which are the same or different; p is 1 or 2; and q is 0 or 1] and/or its condensation product and a scaly filler. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a curable composition and a cured film formed from the curable composition. More specifically, the present invention relates to a curable composition excellent in heat resistance, crack resistance, planarization property, and peel resistance, which can be used for an optical material such as an optical waveguide, and a cured film formed from the curable composition.

  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. ), Interconnects between computers, home wiring, etc. The optical waveguide used in these transmission systems is a basic in optical devices, photoelectric integrated circuits (OEICs), optical integrated circuits (optical ICs), etc. for realizing large-capacity information transmission such as movies and moving images and optical computers, for example. It is a component. Optical waveguides have been intensively studied due to the large amount of demand, while products with particularly high performance and low cost are required.

  Conventionally known quartz optical waveguides and polymer optical waveguides are known as such optical waveguides. Among them, the silica-based optical waveguide has excellent transmission characteristics as compared with the polymer-based optical waveguide, but the vitrification process (at 1200 ° C. or higher) or the etching process performed following the deposition of oxide fine particles. Therefore, strict production conditions for a long time are required for production. On the other hand, a polymer-based optical waveguide can be easily formed into a thin film by a spin coating method, a dip coating method, or the like, and can be manufactured at a low temperature process by reactive ion etching (RIE) or photolithography. In particular, since an optical waveguide using photolithography can be manufactured in a short time, there is an advantage that it can be formed more easily and at a lower cost than a quartz-based optical waveguide.

As a material for the polymer optical waveguide, fluorinated polyimide having excellent heat resistance is known (for example, see Patent Document 1). However, in fluorinated polyimide, there is little effect when the film thickness is thin, but when the film thickness is used for an optical waveguide, the film becomes brittle due to the high crystallinity of its structure, and its elastic modulus In addition, since the refractive index is higher than that of quartz, the optical waveguide made of fluorinated polyimide is used as an optical fiber (quartz as the core). Connection), there is a problem that an optical loss (connection loss) occurs at the connection portion.
On the other hand, when a polymer-based optical waveguide is used over a long period under conditions where temperature changes are severe, peeling may occur from a base material such as a silicon wafer or a glass substrate. For this reason, there is a demand for improving long-term reliability by making it difficult to cause peeling even under severe conditions.
Japanese Patent Laid-Open No. 4-9807

  As described above, the conventional polymer-based optical waveguide is relatively easy to manufacture compared to the quartz-based optical waveguide, but satisfies both low transmission loss and crack resistance, and is peeled from the substrate. It has been demanded to have all the properties that can be used stably in the long term without causing cracks. With this background, the present invention can be used for optical materials such as optical waveguides, and is capable of forming a cured product having excellent heat resistance, crack resistance, flatness, and peel resistance to a substrate. It is an object of the present invention to provide a composition and a cured film formed from the curable composition.

  As a result of intensive studies to solve the above problems, the present inventors have selected from the group consisting of a hydrolyzate of a hydrolyzable silane compound represented by the following general formula (1) and a condensate of the hydrolyzate. In the curable composition containing at least one or more and a scaly filler as essential components, by selecting a long-chain alkyl group as a bonding group on the silicon atom of each hydrolyzable silane compound, It is possible to impart elasticity, improve crack resistance, and because it is possible to form a film by spin coating, it is excellent in flatness, and further contains a scale-like filler, so The present inventors have found that a cured product having excellent peeling resistance (for example, a material that can be used as an optical material such as an optical waveguide) can be formed, and the present invention has been completed.

That is, the present invention provides the following [1] to [4].
[1]
General formula (1):
(R ¹ ) _p (R ² ) _q Si (X) _4-pq (1)
[Wherein, R ¹ represents a nonhydrolyzable identical or different organic group having 1 to 12 carbon atoms containing a fluorine atom, and R ² has 1 to 12 carbon atoms not containing a fluorine atom. Represents a non-hydrolyzable organic group, and X represents the same or different hydrolyzable groups. P is 1 or 2, and q is 0 or 1. ]
A curable composition comprising at least one selected from the group consisting of a hydrolyzate of a hydrolyzable silane compound represented by the formula (1) and a condensate thereof, and a scale-like filler.
[2]
[1] The curable composition of [1], wherein the scaly filler comprises silicate.
[3]
The curable composition according to [1] or [2], which contains a photoacid generator.
[4]
The cured film formed from the curable composition in any one of said [1]-[3].

According to the curable composition of the present invention, a cured product that is excellent in heat resistance, crack resistance, flattening property, and peel resistance to a substrate, and capable of increasing the thickness to 100 μm or more without causing cracks, particularly A cured film can be formed.
The curable composition of the present invention includes a cladding layer and a core portion of an optical waveguide, a planarized film of a laminated optical waveguide, an interlayer insulating film of a hybrid element of an electronic circuit and an optical circuit, a planarized film of a microring resonator, etc. It can be used as an optical material.

The component which comprises the curable composition of this invention is demonstrated.
[Hydrolyzed silane compound, etc.]
The “at least one or more selected from the group consisting of hydrolyzate of hydrolyzable silane compound and condensate thereof” used in the present invention (hereinafter also referred to as “hydrolyzate of silane compound”) is a general formula ( 1):
(R ¹ ) _p (R ² ) _q Si (X) _4-pq (1)
[Wherein, R ¹ represents a nonhydrolyzable identical or different organic group having 1 to 12 carbon atoms containing a fluorine atom, and R ² has 1 to 12 carbon atoms not containing a fluorine atom. Represents a non-hydrolyzable organic group, and X represents the same or different hydrolyzable groups. P is 1 or 2, and q is 0 or 1. ]
Is a hydrolyzate of a hydrolyzable silane compound (hereinafter referred to as “hydrolyzable silane compound (1)”) and / or a condensate thereof.
R ¹ in the formula is a non-hydrolyzable identical or different organic group having 1 to 12 carbon atoms containing a fluorine atom. In the present specification, non-hydrolyzable means that the hydrolyzable group represented by X is a property that exists stably as it is under the condition that it is hydrolyzed. Examples of the non-hydrolyzable organic group include a fluorinated alkyl group, a fluorinated aryl group, or a halogen atom such as a deuterium, a chlorine atom, a bromine atom, or an iodine atom. An organic group substituted by, and the like.

Such a fluorinated alkyl group has a composition formula: C _{m + n} H _2m F _{2n + 1} [m is an integer of 0 to 5, n is an integer of 1 to 12, and m + n is an integer of 1 to 12. is there. From the viewpoint of further improving physical properties such as patterning property and crack resistance of a cured product formed from the curable composition of the present invention, and reducing waveguide loss. Is a general formula: CF ₃ (CF ₂ ) _n-1 (CH ₂ ) _m [m and n are as defined above]. A fluorinated alkyl group represented by Examples of the fluorinated alkyl group include a trifluoromethyl group, a trifluoropropyl group, a heptadecafluorodecyl group, a tridecafluorooctyl group, and a nonafluorohexyl group. Among these, a heptadecafluorodecyl group, a tridecafluorooctyl group, a nonafluorohexyl group and the like having a high fluorine content and a long alkyl chain are preferable. Examples of the fluorinated aryl group include a pentafluorophenyl group. In these fluorinated alkyl groups and fluorinated aryl groups, some or all of the hydrogen atoms may be substituted with deuterium, halogen atoms such as chlorine, bromine, and iodine atoms.

R ² is a non-hydrolyzable organic group having 1 to 12 carbon atoms that does not contain a fluorine atom. Examples of the non-hydrolyzable organic group include alkyl groups, aryl groups, aralkyl groups, and heteroatoms. , An organic group containing a polymerizable group, or an organic group in which some or all of these hydrogen atoms are substituted with deuterium, a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom Etc. These organic groups may be linear, branched or cyclic. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, and an octyl group.

Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, a deuterated phenyl group, and a halogenated phenyl group. Examples of the aralkyl group include a benzyl group and a phenylethyl group. Can be mentioned.
The organic group containing a hetero atom is preferably a non-basic group, and examples thereof include an organic group containing an ether bond, an organic group containing an ester bond, and an organic group containing a sulfide bond.
The organic group containing a polymerizable group is preferably an organic group containing a radical polymerizable group and / or a cationic polymerizable group in the molecule, such as a vinyl group, acryloxy group, methacryloxy group, olefin group, styryl group, etc. An organic group containing a radical polymerizable group; an organic group containing a cationic polymerizable group such as a vinyl ether group, an epoxy group, or an oxetanyl group. By introducing the polymerizable group, radical polymerization and / or cationic polymerization can be caused to cure the curable composition more effectively.

X in the said General formula (1) is the same or a different hydrolysable group. In the present specification, the hydrolyzable group is hydrolyzed by heating for 1 to 10 hours within a temperature range of 0 to 150 ° C. under atmospheric pressure and in the presence of a hydrolysis catalyst described later and water. A group capable of forming a silanol group or a group capable of forming a siloxane condensate.
Examples of the hydrolyzable group represented by X include an alkoxy group having 1 to 12 carbon atoms, a halogen atom, an amino group, and an acyloxy group.

As this C1-C12 alkoxy group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a benzyloxy group etc. are mentioned, for example. These alkoxy groups may have a substituent. Examples of the alkoxy group having a substituent include a phenoxybenzyloxy group, a methoxyethoxy group, an acetoxyethoxy group, a 2- (meth) acryloxyethoxy group, a 3- (Meth) acryloxy propoxy group, (meth) acryloxy group-containing alkoxy group such as 4- (meth) acryloxybutoxy group; glycidoxy group, epoxy group-containing alkoxy group such as 2- (3,4-epoxycyclohexyl) ethoxy group An oxetanyl group-containing alkoxy group such as a methyl oxetanyl methoxy group or an ethyl oxetanyl methoxy group; an alkoxy group containing a 6-membered ring ether group such as an oxacyclohexyloxy group;
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. However, when using the hydrolyzable silane compound (1) having a hydrolyzable group containing a halogen atom, from the viewpoint of enhancing the storage stability of the resulting curable composition, the hydrolyzable silane compound is necessary. It is preferable to remove the hydrogen halide produced by the hydrolysis of (1) by an operation such as neutralization or distillation.
Examples of the acyloxy group include an acetoxy group.

In the general formula (1), p is 1 or 2, but is preferably 1. Q is 0 or 1, but is preferably 0.
Examples of the hydrolyzable silane compound (1) used in the present invention include trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrichlorosilane, and methyl-3,3,3. -Trifluoropropyldichlorosilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropylmethyldichlorosilane, 3,3 , 4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexylmethyldichlorosilane, 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltrichloro Run, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltrimethoxysilane, 3,3,4, 4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltriethoxysilane, 3,3,4,4,5,5,6 6,7,7,8,8,9,9,10,10,10-heptadecafluorodecylmethyldichlorosilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, (pentafluorophenyl) propyltrimethoxysilane , (Pentafluorophenyl) propyltrichlorosilane and the like. Among these, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltriethoxysilane, 3,3, 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltrimethoxysilane, 3,3,4,4,5,5 6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltrichlorosilane and the like are preferable.

  In the present specification, the hydrolyzate of the hydrolyzable silane compound (1) is a hydrolysis in which part or all of the hydrolyzable groups of the hydrolyzable silane compound (1) are changed to silanol groups by the hydrolysis reaction. The reaction mixture means a hydrolyzate condensate of the hydrolyzable silane compound (1), and is a siloxane obtained by a condensation reaction between silanol groups or silanol groups and hydrolyzable groups in the hydrolysis reaction mixture. Condensate is meant.

  The method for preparing a hydrolyzate of a silane compound, which is an essential component of the curable composition of the present invention, is not particularly limited as long as the content of silanol groups in the composition is not excessive or too small. From the viewpoint of controlling the content within the preferable range described below, for example, in a solution obtained by mixing the hydrolyzable silane compound (1), the acid catalyst and the solvent, in an air atmosphere, under atmospheric pressure and stirring, It is preferable to follow the method of heating and stirring at 0 ° C. to 150 ° C. for 1 to 24 hours after adding water dropwise at a temperature below the boiling point of each component in the solution. During the heating and stirring, it is also preferable to concentrate the reaction solution by distillation or replace the solvent as necessary.

  Such a catalyst is not particularly limited as long as it promotes a hydrolysis reaction and a condensation reaction, and examples thereof include a catalyst such as an acid or a base. Examples of the acid include monovalent or polyvalent organic acids such as formic acid, acetic acid and oxalic acid; inorganic acids such as hydrochloric acid, phosphoric acid and sulfuric acid; inorganic salts such as Ti, Zr, Al and B, alkoxides and carboxylates And Lewis acid. Examples of the base include hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide; inorganic bases such as ammonia; amines such as trimethylamine, triethylamine, monoethanolamine and diethanolamine Is mentioned. These may be used alone or in combination of two or more. The amount of the catalyst used varies depending on the type of catalyst used, but usually it is preferably in the range of 0.001 to 5% by mass and in the range of 0.002 to 1% by mass with respect to the total silane compound. More preferably.

Such a solvent is preferably an organic solvent having a boiling point under atmospheric pressure in the range of 50 to 200 ° C. and capable of uniformly dissolving each component, for example, ether; ester; Examples include ketones; hydrocarbons such as aliphatic hydrocarbons and aromatic hydrocarbons; alcohols such as monohydric alcohols and polyhydric alcohols; heteroatom-containing compounds such as nitrogen-containing compounds and sulfur-containing compounds. These solvents may be used alone or in combination of two or more.
It is preferable that it is 1-1000 mass parts with respect to 100 mass parts of hydrolysable silane compounds (1), and, as for the usage-amount of a solvent, it is more preferable that it is 10-100 mass parts.

  Here, the curable composition of the present invention has a hydrolyzable silane compound other than the hydrolyzable silane compound (1) and its hydrolysis in order to adjust the refractive index, curability, viscosity and the like of the cured product. And a composition composed of at least one selected from the group consisting of these products and condensates thereof. In this case, a mixture of the hydrolyzable silane compound (1) and a hydrolyzable silane compound other than the hydrolyzable silane compound (1) is subjected to the hydrolysis reaction and the condensation reaction, and both hydrolyzable silane compounds are obtained. A siloxane condensate formed from may be prepared.

  Examples of hydrolyzable silane compounds other than the hydrolyzable silane compound (1) include tetrachlorosilane, tetraaminosilane, tetraacetoxysilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraphenoxysilane, and tetrabenzyloxysilane. Silane compounds having four hydrolyzable groups such as trimethoxysilane and triethoxysilane; methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriisopropoxy It has three hydrolyzable groups such as silane, ethyltributoxysilane, butyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and deuterated methyltrimethoxysilane. Silane compounds having two hydrolyzable groups such as dimethyldichlorosilane, dimethyldiaminosilane, dimethyldiacetoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and dibutyldimethoxysilane .

The content of silanol groups (Si—OH) in the number of bonding groups on all silicon atoms in the silane compound hydrolyzate used in the present invention is preferably in the range of 10 to 50%, and 20 to 40%. More preferably, it is the range. If the silanol group content is outside this range, patterning of the desired shape cannot be obtained during alkali development, or the waveguide loss value may increase when an optical waveguide is formed. Absent.
The silanol group content can be quantified by ²⁹ Si-NMR or the like. For example, each composition is dissolved in deuterated chloroform which is an NMR measurement solvent, and a plurality of silane components having different substituents and bonding groups appearing from −120 ppm to −60 ppm in ²⁹ Si-NMR (based on dimethylsiloxane) The peaks are separated by curve fitting, the mol% of each component is calculated from the area ratio of the peaks, and the number of silanol groups in each component obtained is multiplied to contain silanol groups in the total number of bonding groups on all silicon atoms. The rate (%) is calculated.

［一般式（２）又は（３）中、Ｒ³はフッ素原子を含有する炭素数が１〜１２である非加水分解性の有機基を示し、Ｒ⁴はフッ素原子を含んでいてもよい炭素数が１〜１２である非加水分解性の有機基を示す。なお、Ｒ³とＲ⁴は同一の基であってもよい。］
Ｒ³が示す、フッ素原子を含有する炭素数が１〜１２である非加水分解性の有機基としては、一般式：ＣＦ₃（ＣＦ₂）_n-1（ＣＨ₂）_m ［ｍ及びｎは前記定義のとおりである。］で表される基であるのが好ましい。 The hydrolyzate of the silane compound used in the present invention is represented by the following general formulas (2) and (3) from the viewpoint of further improving the physical properties such as patterning property, crack resistance and waveguide loss of the cured product. It is preferable to have at least one or more members selected from the group consisting of the structures described above.

[In General Formula (2) or (3), R ³ represents a non-hydrolyzable organic group having 1 to 12 carbon atoms containing a fluorine atom, and R ⁴ is carbon that may contain a fluorine atom. The nonhydrolyzable organic group whose number is 1-12 is shown. R ³ and R ⁴ may be the same group. ]
The non-hydrolyzable organic group having 1 to 12 carbon atoms containing a fluorine atom represented by R ³ is represented by the general formula: CF ₃ (CF ₂ ) _n-1 (CH ₂ ) _m [m and n are As defined above. ] Is preferable.

［一般式（４）又は（５）中、Ｒ⁵はフェニル基又はフッ素化フェニル基を示し、Ｒ⁶はフッ素原子を含んでいてもよい炭素数が１〜１２である非加水分解性の有機基を示す。なお、Ｒ⁵とＲ⁶は同一の基であってもよい。］ Moreover, the hydrolyzate of the silane compound used by this invention is represented by following General formula (4) and (5) from a viewpoint of improving further physical properties, such as the patternability of the hardened | cured material, and heat resistance. It is preferable to have at least one of the group consisting of structures.

[In General Formula (4) or (5), R ⁵ represents a phenyl group or a fluorinated phenyl group, and R ⁶ represents a non-hydrolyzable organic group having 1 to 12 carbon atoms which may contain a fluorine atom. Indicates a group. R ⁵ and R ⁶ may be the same group. ]

  The hydrolyzable silane compound having the structure represented by the general formula (4) or the general formula (5) is hydrolyzable other than the hydrolyzable silane compound (1) or the hydrolyzable silane compound (1). Among the silane compounds, compounds having a phenyl group or a fluorinated phenyl group can be mentioned, and among these, phenyltrimethoxysilane, phenyltriethoxysilane, pentafluorophenyltrimethoxysilane and the like are particularly preferable.

  Furthermore, the hydrolyzate of the silane compound used in the present invention further improves the physical properties such as patterning property, crack resistance, heat resistance and waveguide loss of the cured product, and further from the viewpoint of controlling the refractive index. , At least one or more of the groups consisting of the structures represented by the general formulas (2) and (3), and at least one or more of the group consisting of the structures represented by the general formulas (4) and (5). It is preferable to have.

[Scaly filler]
The scale-like filler used in the present invention does not peel off from the substrate even when an optical member such as an optical waveguide made of the curable composition of the present invention is placed in an environment with a large temperature change over a long period of time. Formulated to maintain good adhesion.
Preferable examples of the scale-like filler include a silicate having a layered structure from the viewpoint of compatibility with a hydrolyzate of a silane compound.
The scaly filler is preferably subjected to lipophilic treatment in order to enhance the compatibility with the hydrolyzate of the silane compound.
Examples of the silicate having a layered structure include synthetic smectite, natural smectite (for example, montmorillonite), synthetic mica, natural mica, talc, kaolin and the like.
Among these, synthetic smectite that has been subjected to lipophilic treatment has good compatibility with other components (such as hydrolysates of silane compounds, solvents, etc.) and can impart excellent peel resistance. Are preferably used.

As a commercial item of a scale-like filler, Lucentite SPN, Lucentite SAN, Lucentite STN (above, the product made by Corp Chemical) etc. are mentioned, for example.
The blending ratio of the flaky filler in the total amount of the hydrolyzate of the silane compound and the flaky filler is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and particularly preferably 15 to 35% by mass. is there. When the blending ratio is less than 5% by mass, when an optical member such as an optical waveguide is produced using the curable composition, the peel resistance of the optical member relative to the substrate may be lowered. When the blending ratio exceeds 50% by mass, the viscosity of the curable composition is excessively increased, the applicability is deteriorated, and the mechanical strength after curing may be decreased.

[Photoacid generator]
The curable composition of the present invention can contain a photoacid generator.
When radiation is applied to the curable composition containing the photoacid generator, the photoacid generator is decomposed to release an acidic active substance that photocures the curable composition.
Here, examples of the radiation include visible light, ultraviolet rays, infrared rays, X-rays, electron beams, α rays, and γ rays. However, it is preferable to use ultraviolet rays from the viewpoint of having a constant energy level, a high curing rate, and a relatively inexpensive and compact irradiation apparatus.

Examples of the photoacid generator include an onium salt having a structure represented by the following general formula (6), a sulfonic acid derivative having a structure represented by the following general formula (7), and the like.
_{^{[R 7 a R 8 b R}} 9 c R 10 d W] + m [MZ m + n] -m (6)
[In General Formula (6), the cation is an onium ion, W is S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl, or —N≡N, and R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same or different organic groups, a, b, c and d are each an integer of 0 to 3, and (a + b + c + d) is equal to the valence of W. M is a metal or metalloid constituting the central atom of the 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. ]

Q _s- [S (= O) ₂ -R ¹¹ ] _t (7)
[In the general formula (7), Q is a monovalent or divalent organic group, R ¹¹ is 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. is there. ]

(1) Onium salt Specific examples of the anion [MZ _{m + n} ] in the general formula (6) include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), Examples include hexafluoroarsenate (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ), tetraphenyl borate, tetrakis (trifluoromethylphenyl) borate, tetrakis (pentafluoromethylphenyl) borate and the like.
Further, instead of the anion _{[MZ m + n]} in the general formula (6), the general formula ^- it is also preferable to use the anion represented by _[MZ n OH]. Furthermore, perchlorate ion (ClO ₄ ⁻ ), trifluoromethane sulfonate ion (CF ₃ SO ₄ ⁻ ), fluorosulfonate ion (FSO ₄ ⁻ ), toluene sulfonate ion, trinitrobenzene sulfonate anion, trinitrotoluene sulfonate Onium salts having other anions such as anions can also be used.

［一般式（８）中、Ｒ^１２およびＲ^１３は、それぞれ独立して水素原子又はアルキル基、Ｒ^１４は水酸基または−ＯＲ^１５（但し、Ｒ^１５は１価の有機基である。）を示し、ａは４〜７の整数、ｂは１〜７の整数である。ナフタレン環への各置換基の結合位置は特に限定されない。］
［Ｒ^１６−Ｐｈ^１−Ｉ^＋−Ｐｈ^２−Ｒ^１７］［Ｙ⁻］ （９）
［一般式（９）中、Ｒ^１６およびＲ^１７は、それぞれ１価の有機基であり、同一でも異なっていてもよく、Ｒ^１６およびＲ^１７の少なくとも一方は、炭素数が４以上のアルキル基を有しており、Ｐｈ^１およびＰｈ^２はそれぞれ芳香族基であり、同一でも異なっていてもよく、Ｙ⁻は１価の陰イオンであり、周期律表３族、５族のフッ化物陰イオンもしくは、ＣｌＯ_４ ⁻、ＣＦ_３ＳＯ_３ ⁻から選ばれる陰イオンである。］ The onium salt is preferably an aromatic onium salt, particularly preferably a triarylsulfonium salt, a compound represented by the following general formula (8), a diaryl iodonium salt represented by the following general formula (9) or a triaryl iodonium. Salt.

[In General Formula (8), R ¹² and R ¹³ each independently represent a hydrogen atom or an alkyl group, R ¹⁴ represents a hydroxyl group or —OR ¹⁵ (where R ¹⁵ is a monovalent organic group). , A is an integer of 4-7, b is an integer of 1-7. The bonding position of each substituent to the naphthalene ring is not particularly limited. ]
^{[R 16 -Ph 1 -I + -Ph} 2 -R 17] [Y -] (9)
[In General Formula (9), R ¹⁶ and R ¹⁷ are each a monovalent organic group and may be the same or different, and at least one of R ¹⁶ and R ¹⁷ is an alkyl group having 4 or more carbon atoms. And Ph ¹ and Ph ² are each an aromatic group, which may be the same or different, Y ⁻ is a monovalent anion, and is a group 3 or group 5 fluoride anion in the periodic table. An ion or an anion selected from ClO ₄ ⁻ and CF ₃ SO ₃ ^— . ]

Examples of the compound represented by the general formula (8) include 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 1- (4,7- And dihydroxy) -naphthyltetrahydrothiophenium trifluoromethanesulfonate, 1- (4,7-di-t-butoxy) -naphthyltetrahydrothiophenium trifluoromethanesulfonate, and the like.
Further, as the diaryl iodonium salt, specifically, (4-n-decyloxyphenyl) phenyl iodonium hexafluoroantimonate, [4- (2-hydroxy-n-tetradecyloxy) phenyl] phenyl iodonium 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 (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) Examples thereof include one or a combination of two or more of iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium hexafluorophosphate, bis (dodecylphenyl) iodonium trifluoromethylsulfonate, and the like.

(2) Sulphonic acid derivatives The sulfonic acid derivatives represented by the general formula (7) include disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imide sulfonates, benzoin sulfonates, 1-oxy Examples include sulfonates of 2-hydroxy-3-propyl alcohol, pyrogallol trisulfonates, benzyl sulfonates, and the like.
Among these, imide sulfonates are preferable, and trifluoromethyl sulfonate derivatives are more preferable.

  Although the compounding quantity of a photo-acid generator is not restrict | limited in particular, Preferably it is 0.01-15 mass parts with respect to 100 mass parts, such as a hydrolyzate of a silane compound, More preferably, it is 0.1-10. Part by mass. If the blending amount is less than 0.01 parts by mass, the photocurability tends to decrease and a sufficient curing rate tends not to be obtained. If the blending amount exceeds 15 parts by mass, the weather resistance and heat resistance of the resulting cured product tend to decrease.

[Acid diffusion control agent]
The curable composition of the present invention can contain an acid diffusion controller.
An acid diffusion control agent is defined as a compound having an action of controlling the diffusion of an acidic active substance generated from a photoacid generator by light irradiation in a coating and suppressing a curing reaction in a non-irradiated region. However, in order to distinguish from a photoacid generator by definition, an acid diffusion controller is a compound that does not have an acid generating function.
By adding such an acid diffusion controller, the photocurable composition can be effectively cured and the pattern accuracy can be improved.

As the type of the acid diffusion controller, a nitrogen-containing organic compound whose basicity does not change by exposure or heat treatment during the formation process is preferable.
Examples of such nitrogen-containing organic compounds include compounds represented by the following general formula (10).
NR ¹⁸ R ¹⁹ R ²⁰ (10)
[In General Formula (10), R ¹⁸ , R ¹⁹ and R ²⁰ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. To express. ]

Other nitrogen-containing organic compounds include diamino compounds having two nitrogen atoms in the same molecule, diamino polymers having three or more nitrogen atoms, amide group-containing compounds, urea compounds, nitrogen-containing heterocycles. A compound etc. can be mentioned.
Specific examples of the nitrogen-containing organic compound include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n -Dialkylamines such as pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine , Tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, etc. Amines; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, - methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, aromatic amines such as 1-naphthylamine; can be mentioned ethanolamine, diethanolamine, alkanolamines such as triethanolamine and the like.
In addition, an acid diffusion control agent can also be used individually by 1 type, or can also be used in mixture of 2 or more types.
The compounding amount of the acid diffusion controller is preferably 0.001 to 15 parts by mass, more preferably 0.005 to 5 parts by mass with respect to 100 parts by mass of the hydrolyzate of the silane compound.
When the blending amount is less than 0.001 part by mass, the pattern shape and dimensional reproducibility of the optical waveguide may be lowered depending on the process conditions. When this compounding quantity exceeds 15 mass parts, the photocurability of a curable composition may fall.

[Basic compounds]
The curable composition of the present invention can contain a basic compound.
As the basic compound, a compound (base generator) that releases a basic active substance capable of curing the curable composition of the present invention in response to an external stimulus such as radiation or heat is used. preferable.
Examples of such basic compounds include photobase generators and thermal base generators. Among these, a photobase generator is preferable from the viewpoint of storage stability.
Examples of photobase generators include 2-nitrobenzyl N-cyclohexyl carbamate (commercial product name: NBC-101, manufactured by Midori Chemical Co., Ltd.), triphenylsulfonium hydroxide (commercial product name: TPS-OH, Midori Chemical Co., Ltd.) Company), anisoin N-cyclohexyl carbamate (commercial product name: ANC-101, manufactured by Midori Chemical Co., Ltd.), nifedipine (manufactured by Tokyo Chemical Industry Co., Ltd.), and the like.
Examples of the thermal base generator include Nt-butoxycarbonyl-2-phenylbenzimidazole, Nt-butoxycarbonyldicyclohexylamine and the like.
Although the compounding quantity of a basic compound is not restrict | limited in particular, Preferably it is 5 mass parts or less with respect to 100 mass parts in total of the hydrolyzate of a silane compound, and a scale-like filler. When the blending amount exceeds 5 parts by mass, cracks are likely to occur in the coating film due to rapid curing, which is not preferable.

[solvent]
The curable composition of the present invention can improve storage stability by blending a solvent, can impart an appropriate viscosity, and forms a cured film having a uniform film thickness. Can do.
As such a solvent, the same solvent as used in the preparation of the hydrolyzate of the above-mentioned silane compound can be used, but from the viewpoint of further improving the storage stability of the curable composition of the present invention, 1 It is preferable to use a hydric or polyhydric alcohol, a ketone, an ester or an aromatic hydrocarbon, and examples thereof include propylene glycol monomethyl ether, ethyl lactate, methyl isobutyl ketone, methyl amyl ketone, toluene, xylene and methanol. These solvents may be used alone or in combination of two or more.

  Moreover, it is preferable to select suitably the solvent mix | blended with the curable composition of this invention in consideration of the coating method of a composition. For example, since a thin film having a uniform thickness can be easily obtained, it is preferable to use a spin coating method. Solvents used in this case include glycol ethers such as ethylene glycol monoethyl ether and propylene glycol monomethyl ether. Glycol alkyl ether acetates such as ethyl cellosolve acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate; Esters such as ethyl lactate and ethyl 2-hydroxypropionate; Diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether Diethylene glycols such as methyl isobutyl ketone, 2-heptanone, cyclohexanone, methylamino Ketones are preferred, such as ketones, among these, ethyl cellosolve acetate, propylene glycol methyl ether acetate, ethyl lactate, methyl isobutyl ketone, methyl amyl ketone are particularly preferred.

  The blending amount of the solvent blended in the curable composition of the present invention varies depending on the blending amount of the scaly filler, but is preferably 1 to 300 parts by mass with respect to 100 parts by mass of the hydrolyzate of the silane compound. Preferably it is 2-200 mass parts. When the blending amount is within this range, the storage stability of the composition can be improved, an appropriate viscosity can be imparted, and a cured film having a uniform film thickness can be formed.

Furthermore, the curable composition of the present invention includes, for example, a thermal acid generator, a reactive diluent, a radical generator (photopolymerization initiator), and a photosensitizer, as long as the objects and effects of the present invention are not impaired. , Metal alkoxide, inorganic fine particles, dehydrating agent, leveling agent, polymerization inhibitor, polymerization initiation aid, wettability improver, surfactant, plasticizer, UV absorber, antioxidant, antistatic agent, silane coupling agent It is also preferable to add a polymer additive or the like.
The viscosity of the curable composition of the present invention is preferably 5 to 5,000 mPa · s, more preferably 10 to 1,000 mPa · s at 25 ° C. When the viscosity exceeds 5,000 mPa · s, it may be difficult to form a uniform coating film, which is not preferable. The viscosity of the curable composition of this invention can be suitably adjusted with the compounding quantity of a solvent or a reactive diluent.

The cured film of the present invention is obtained by applying the curable composition of the present invention to the surface of a substrate, drying or prebaking to form a thin film, and then curing the thin film by light irradiation and / or heating. Can be formed.
After applying the curable composition, it is preferable to pre-bake at a temperature of 50 to 200 ° C., for example, for 5 minutes to 1 hour, 30 to 400 ° C., preferably 50 to 300 ° C. even after exposure by light irradiation. For example, it is preferable to perform heat treatment over 5 minutes to 72 hours. Thereby, the coating film whole surface can fully be hardened.
The thickness of the cured film is not particularly limited, but is preferably 50 μm or more, more preferably 80 μm or more, and particularly preferably 100 μm or more when it is intended to increase the thickness without causing cracks. . In this case, the upper limit value of the cured film is preferably 300 μm or less, more preferably 200 μm or less, from the viewpoint of crack resistance.
The light used for forming the cured film is not particularly limited, but usually, light in the ultraviolet to visible region of 200 to 450 nm, preferably light including ultraviolet light having a wavelength of 365 nm is used. Irradiation at a wavelength of 200 to 450 nm is such that the illuminance is 1 to 1,000 mW / cm ² and the irradiation amount is 0.01 to 5,000 mJ / cm ² , preferably 0.1 to 1,000 mJ / cm ^2. Done and exposed.

  Visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays and the like can be used as the type of light to be irradiated, but from the industrial versatility of the light source, preferably 200 to 400 nm, particularly A wavelength including ultraviolet rays of 365 nm is preferable. As the irradiation device, for example, a lamp light source that simultaneously irradiates a wide area such as a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or an excimer lamp, and a laser light source such as a pulse or continuous light source, or both Accordingly, a mirror, a lens, or an optical fiber that generates convergent light can be used.

  Here, as a method of applying the curable composition of the present invention to a substrate, for example, spin coating method, dipping method, spray method, bar coating method, roll coating method, curtain coating method, gravure printing method, silk screen method Alternatively, a method such as an ink jet method can be used. Among these, it is more preferable to employ the spin coat method because a thin film having a uniform thickness can be obtained.

  The refractive index of the cured product formed from the curable composition of the present invention is composed of a hydrolyzable silane compound (1) and, if necessary, a hydrolyzable silane compound other than the hydrolyzable silane compound (1). From the compound group, a hydrolyzable silane compound that is a monomer that imparts a high refractive index and a hydrolyzable silane compound that is a monomer that imparts a low refractive index are appropriately selected and used in combination to obtain a desired value (for example, The refractive index of light having a wavelength of 1,310 nm can be adjusted to a value of 1.445 ± 0.002) which is substantially the same value as quartz.

Hereinafter, the present invention will be specifically described by way of examples.
[Example 1]
In a flask equipped with a stirrer and a reflux tube, phenyltrimethoxysilane (30.79 g), 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10 , 10,10-heptadecafluorodecyltriethoxysilane (22.64 g), tetraethoxysilane (4.62 g), 1-methoxy-2-propanol (29.93 g) and oxalic acid (0.04 g) are added. After stirring, the resulting solution was heated to 60 ° C. Then, distilled water (11.98 g) was added dropwise, and after completion of the addition, the mixture was stirred at 120 ° C. for 6 hours to produce a siloxane oligomer.
Next, the amount of the synthetic smectite (trade name: Lucentite SPN, manufactured by Co-op Chemical Co., Ltd.) that has been subjected to lipophilic treatment, which is a scaly filler, is 10 parts by mass in a total of 100 parts by mass with the siloxane oligomer (solid content). Further, 0.32 g of 1- (4,7-di-t-butoxy) -naphthyltetrahydrothiophenium trifluoromethanesulfonate as a photoacid generator, and tri-n-octylamine 0. 2 as an acid diffusion controller. 03 g of 1-methoxy-2-propanol in an amount such that the final solid content concentration in the composition was 65% by mass was added and mixed uniformly to obtain a curable composition.
The obtained curable composition was applied onto the surface of a silicon substrate with a spin coater, dried at 120 ° C. for 10 minutes, and then exposed to ultraviolet light having a wavelength of 365 nm and an illuminance of 6 mW / cm ² to an exposure machine (Canon photo aligner). For 3 minutes. Furthermore, the cured film was produced by heating at 200 degreeC for 1 hour.

[Examples 2 to 4, Comparative Example 1]
A curable composition and a cured film were obtained in the same manner as in Example 1 except that the amount of synthetic smectite added was changed to that shown in Table 1.
[Comparative Example 2]
Instead of synthetic smectite, a granular filler (trade name: MEK-ST, manufactured by Nissan Chemical Industries, Ltd.) subjected to lipophilic treatment in an amount of 20 parts by mass in a total of 100 parts by mass with siloxane oligomer (solid content). Except having used, it carried out similarly to Example 1, and obtained the curable composition and the cured film.

[Evaluation of physical properties]
The physical properties of the obtained curable composition and cured film were evaluated as follows.
(1) Application | coating property After apply | coating a curable composition on a silicon substrate, the average film thickness was measured with the optical microscope with respect to the formed cured film. The case where the viscosity of the curable composition is small, the workability at the time of application is good, and the average film thickness within the design value ± 5 μm with respect to the design value (100 μm) is obtained, “、”, curing When the average film thickness within the design value ± 5 μm is obtained with respect to the design value (100 μm), the viscosity of the adhesive composition is slightly large and the workability at the time of application is slightly inferior. The case where the viscosity of the product was too large and coating was difficult, or the average film thickness within the design value ± 5 μm was not obtained with respect to the design value (100 μm) was designated as “x”.
(2) Cooling cycle test A cured film on a silicon substrate was prepared as 100 chips for each of the various types (Examples 1 to 4 and Comparative Examples 1 to 2), and the temperature was 85 ° C. and the relative humidity was 85%. After being allowed to stand for 2,000 hours under the conditions, it was allowed to stand at a temperature of 25 ° C. and a relative humidity of 50% for 24 hours, and it was visually confirmed whether or not peeling occurred from the silicon substrate. Of 100 samples, 0 to 10 were peeled off, “◎”, 11-20 were peeled from “◯”, 21-30 were peeled from “ [Delta] ", a case where peeling occurred on 31 sheets or more was marked as" x ".
The results are shown in Table 1.

  From Table 1, in Examples 1-4 using the curable composition containing a specific amount of scaly filler, the results of the thermal cycle test (exfoliation resistance test) are good, whereas the scaly filler It can be seen that in Comparative Example 1 using a curable composition containing no slag and Comparative Example 2 using a curable composition containing a particulate filler, the results of the thermal cycle test are inferior.

Claims (4)

General formula (1):
(R ¹ ) _p (R ² ) _q Si (X) _4-pq (1)
[Wherein, R ¹ represents a nonhydrolyzable identical or different organic group having 1 to 12 carbon atoms containing a fluorine atom, and R ² has 1 to 12 carbon atoms not containing a fluorine atom. Represents a non-hydrolyzable organic group, and X represents the same or different hydrolyzable groups. P is 1 or 2, and q is 0 or 1. ]
A curable composition comprising at least one selected from the group consisting of a hydrolyzate of a hydrolyzable silane compound represented by the formula (1) and a condensate thereof, and a scale-like filler.   The curable composition according to claim 1, wherein the scaly filler comprises silicate.   The curable composition of Claim 1 or 2 containing a photo-acid generator. The cured film formed from the curable composition of any one of Claims 1-3.