JP2009179770A - Organic and inorganic composite material and optical article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic and inorganic composite material having a high transparency and refractive index, and excellent in heat resistance and moldability. <P>SOLUTION: This organic and inorganic composite material is provided by dispersing inorganic fine particles having a 1 to 15 nm number-average particle diameter in a thermoplastic resin having at least one unit structure expressed by general formula (1) [wherein, X is H, a substituted or a non-substituted alkyl, or a substituted or a non-substituted aryl]. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic-inorganic composite material having high transparency and refractive index, excellent heat resistance and moldability, and a lens substrate (for example, spectacle lens, optical device lens) including the same. , Optoelectronic lenses, laser lenses, pickup lenses, in-vehicle camera lenses, portable camera lenses, digital camera lenses, OHP lenses, and the like.

  In recent years, research on optical materials has been actively conducted, and particularly in the field of lens materials, high refractive index, low dispersibility (that is, high Abbe number), heat resistance, transparency, easy moldability, light weight, and moisture resistance. The development of materials with excellent chemical resistance and solvent resistance is strongly desired.

  Plastic lenses are lighter and harder to break than inorganic materials such as glass and can be processed into various shapes, so in recent years they are rapidly spreading not only to spectacle lenses but also to optical materials such as portable camera lenses and pickup lenses. .

  Along with this, it has been required to increase the refractive index of the material itself in order to reduce the thickness of the lens. For example, a technique for introducing a sulfur atom into a polymer (see Patent Document 1 and Patent Document 2) In addition, a technique for introducing a halogen atom or an aromatic ring into a polymer (see Patent Document 3), a technique using a maleimide copolymer (see Patent Document 4), and the like have been actively studied. However, a plastic material that has a sufficiently large refractive index and has good transparency and can be used as a substitute for glass has not yet been developed.

Since it is difficult to increase the refractive index with only an organic substance, attempts have been made to produce a high refractive index material by dispersing an inorganic substance having a high refractive index in a resin matrix (see Patent Documents 5 and 6). In order to reduce attenuation of transmitted light due to Rayleigh scattering, it is preferable to uniformly disperse inorganic fine particles having a particle diameter of 15 nm or less in the resin matrix. However, since primary particles having a particle diameter of 15 nm or less are very likely to aggregate, it is extremely difficult to uniformly disperse them in the resin matrix. In addition, when the attenuation of transmitted light in the optical path length corresponding to the lens thickness is taken into consideration, the amount of inorganic fine particles added must be limited. For this reason, it has not been possible to disperse the fine particles in the resin matrix at a high concentration without reducing the transparency of the resin.
JP 2002-131502 A Japanese Patent Laid-Open No. 10-298287 JP 2004-244444 A Japanese Patent Laid-Open No. 5-117334 JP 61-291650 A JP 2003-73564 A

Thus, an organic-inorganic composite material having high transparency and refractive index, excellent heat resistance and moldability, and optical components such as lenses comprising the same have not yet been found. The development was desired.
The present invention has been made in view of the above circumstances, and its purpose is that the inorganic fine particles are uniformly dispersed in the resin matrix, the transparency and refractive index are high, and the heat resistance and moldability are excellent. An organic-inorganic composite material and an optical component such as a lens base material using the same are provided.

  As a result of intensive studies to achieve the above object, the present inventors have found that an organic-inorganic composite material in which inorganic fine particles having a number average particle diameter of 1 to 15 nm are dispersed in a resin having a specific structural unit is inorganic. The present inventors have found that the uniform dispersion effect of fine particles has high refractive properties and excellent transparency, and also has heat resistance and moldability, and the present invention has been completed. That is, the following present invention has been provided as means for solving the problems.

〔一般式（１）中、Ｘは水素原子、置換もしくは無置換のアルキル基、または置換もしくは無置換のアリール基を表す。〕
［２］ 前記熱可塑性樹脂の波長５８９ｎｍにおける屈折率が１.５７以上であることを特徴とする［１］に記載の有機無機複合材料。
［３］ 前記熱可塑性樹脂の数平均分子量が１００００〜２０００００であることを特徴とする［１］または［２］に記載の有機無機複合材料。
［４］ 上記一般式（１）で表される単位構造を前記熱可塑性樹脂中に３〜７０質量％含むことを特徴とする［１］〜［３］のいずれか一項に記載の有機無機複合材料。 [1] An organic material comprising inorganic fine particles having a number average particle diameter of 1 to 15 nm in a thermoplastic resin having at least one unit structure represented by the following general formula (1) Inorganic composite material.

[In General Formula (1), X represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. ]
[2] The organic-inorganic composite material according to [1], wherein the thermoplastic resin has a refractive index of 1.57 or more at a wavelength of 589 nm.
[3] The organic-inorganic composite material according to [1] or [2], wherein the thermoplastic resin has a number average molecular weight of 10,000 to 200,000.
[4] The organic / inorganic structure according to any one of [1] to [3], wherein the thermoplastic resin contains the unit structure represented by the general formula (1) in an amount of 3 to 70% by mass. Composite material.

［Ｒ¹¹、Ｒ¹²、Ｒ¹³、Ｒ¹⁴、Ｒ¹⁵、Ｒ¹⁶は、それぞれ独立に水素原子、置換または無置換のアルキル基、置換または無置換のアルケニル基、置換または無置換のアルキニル基、あるいは、置換または無置換のアリール基を表す。］、−ＳＯ₃Ｈ、−ＯＳＯ₃Ｈ、−ＣＯ₂Ｈ、−ＯＨ、−Ｓｉ（ＯＲ¹⁷）_nＲ¹⁸ _n［Ｒ¹⁷、Ｒ¹⁸はそれぞれ独立に水素原子、置換または無置換のアルキル基、置換または無置換のアルケニル基、置換または無置換のアルキニル基、あるいは、置換または無置換のアリール基を表し、ｎは１〜３の整数を表す。］
［６］ 前記熱可塑性樹脂が前記官能基をポリマー鎖１本あたり平均０.１〜２０個有していることを特徴とする［５］に記載の有機無機複合材料。 [5] The organic-inorganic composite material according to any one of [1] to [4], wherein the thermoplastic resin has one or more functional groups selected from the following.

[R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, Alternatively, it represents a substituted or unsubstituted aryl group. _{], - SO 3 H, -OSO} 3 H, -CO 2 H, -OH, -Si (OR 17) n R 18 n [R 17, R 18 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group Represents a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group, and n represents an integer of 1 to 3. ]
[6] The organic-inorganic composite material according to [5], wherein the thermoplastic resin has an average of 0.1 to 20 functional groups per polymer chain.

[7] The organic-inorganic composite material according to any one of [1] to [6], wherein a refractive index of the inorganic fine particles at a wavelength of 589 nm is in a range of 1.90 to 3.00.
[8] The inorganic fine particles contain at least one selected from the group consisting of zirconium oxide, zinc oxide, tin oxide, and titanium oxide, according to any one of [1] to [7]. Organic inorganic composite material.
[9] The refractive index of the organic-inorganic composite material at a wavelength of 589 nm is 1.63 or more, and the light transmittance in terms of a thickness of 1 mm at a wavelength of 589 nm is 70% or more. [8] The organic-inorganic composite material according to any one of [8].

[10] An optical component comprising the organic-inorganic composite material according to any one of [1] to [9].
[11] The optical component according to [10], wherein the optical component is a lens substrate.

  According to the present invention, an organic-inorganic composite material having high transparency and refractive index, and having both heat resistance and moldability, and an optical component comprising the same and having high transparency and refractive index and excellent heat resistance Can be provided.

  Hereinafter, the organic-inorganic composite material of the present invention, the method for producing the same, and the optical component including the same will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Organic inorganic composite materials]
The light transmittance of the organic-inorganic composite material of the present invention is preferably 70% or more, more preferably 75% or more, and particularly preferably 80% or more in terms of 1 mm thickness at a wavelength of 589 nm. The light transmittance at a wavelength of 405 nm is preferably 60% or more, more preferably 65% or more, and particularly preferably 70% or more. If the light transmittance in terms of 1 mm thickness at a wavelength of 589 nm is 70% or more, it is easy to obtain an optical article (particularly a lens substrate) having more preferable properties. The light transmittance in terms of 1 mm thickness in the present invention is obtained by forming an organic-inorganic composite material to produce a 1.0 mm thick substrate, and measuring an ultraviolet-visible absorption spectrum (UV-3100, Shimadzu Corporation). This is a value measured by a manufacturer.

  The organic-inorganic composite material of the present invention preferably has a refractive index of 1.63 or more at 22 ° C. and a wavelength of 589 nm, more preferably 1.65 or more, and even more preferably 1.66 or more. preferable.

  It is desirable that the organic-inorganic composite material of the present invention is not easily charged for the purpose of preventing dust from adhering to the molded body. The charged voltage is preferably −2 to 15 kV, more preferably −1.5 to 7.5 kV, and particularly preferably −1.0 to 7.0 kV.

  The organic-inorganic composite material of the present invention preferably has a glass transition temperature of 100 ° C to 400 ° C, more preferably 110 ° C to 380 ° C, more preferably 120 ° C to 380 ° C, and 130 ° C. Even more preferably, it is ˜380 ° C. When the glass transition temperature is 100 ° C. or higher, sufficient heat resistance is easily obtained, and when the glass transition temperature is 400 ° C. or lower, molding processing tends to be easily performed.

  In the organic-inorganic composite material of the present invention, the volatile component when held at 200 ° C. for 2 hours is preferably 2% by mass or less, and the volatile component when held at 230 ° C. for 2 hours is 2% by mass or less. It is more preferable that the volatile component when held at 250 ° C. for 2 hours is 2% by mass or less.

  The saturated water absorption of the organic-inorganic composite material of the present invention is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

[Thermoplastic resin]
The thermoplastic resin used in the present invention has at least one unit structure represented by the general formula (1). Moreover, it is preferable that the thermoplastic resin used by this invention is a random copolymer which has a carboxyl group in a side chain. Examples of the polymer include any conventionally known polymers such as vinyl polymers obtained by polymerization of vinyl monomers, polyethers, ring-opening metathesis polymerization polymers, and condensation polymers (polycarbonate, polyester, polyamide, polyether ketone, polyether sulfone, etc.). However, a vinyl polymer, a ring-opening metathesis polymer, a polycarbonate, and a polyester are preferable, and a vinyl polymer is more preferable from the viewpoint of production suitability.

<Unit structure represented by general formula (1)>
The thermoplastic resin used in the present invention has at least one unit structure represented by the following general formula (1).

  In general formula (1), X represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

  The alkyl group that X can take may be linear, branched, or cyclic. Examples of linear or branched alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, heptyl, An isoheptyl group, an octyl group, etc. can be mentioned. The linear or branched alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably 1 to 10 carbon atoms, and 1 to 6 carbon atoms. Even more preferably, it is particularly preferably 1-4. Examples of the cyclic alkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a bicyclo [2.2.1] heptyl group. The number of carbon atoms of the cyclic alkyl group is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 10, still more preferably 3 to 8, and 4 to 4 8 is particularly preferred.

  Examples of the aryl group that X can take include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group and the like. it can. The aryl group preferably has 6 to 30 carbon atoms, more preferably 6 to 22 carbon atoms, still more preferably 6 to 18 carbon atoms, still more preferably 1 to 14 carbon atoms, and more preferably 6 to 10 carbon atoms. It is particularly preferred that

  The alkyl group or aryl group that X can take may have a substituent. The type of the substituent is not particularly limited, but as a representative example, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an aliphatic group [saturated aliphatic group (an alkyl group, a cycloalkyl group, a bicycloalkyl group) , Meaning a cyclic saturated aliphatic group including a bridged cyclic saturated hydrocarbon group or a spiro saturated hydrocarbon group), an unsaturated aliphatic group (having a double bond or a triple bond, such as an alkenyl group or an alkenyl group) A chain unsaturated aliphatic group or a cycloalkenyl group, a bicycloalkenyl group, a cyclic unsaturated aliphatic group including a bridged cyclic unsaturated hydrocarbon group or a spiro unsaturated hydrocarbon group)), an aryl group (Preferably a phenyl group which may have a substituent), a heterocyclic group (preferably 5 to 8 in which the ring-constituting atoms include an oxygen atom, a sulfur atom or a nitrogen atom) Ring, which may be condensed with an alicyclic ring, aromatic ring or heterocyclic ring), cyano group, aliphatic oxy group (alkoxy group as representative examples), aryloxy group, acyloxy group, carbamoyloxy group, aliphatic oxy group Carbonyloxy groups (typically alkoxycarbonyloxy groups, aryloxycarbonyloxy groups, amino groups [including aliphatic amino groups (typically alkylamino groups), anilino groups and heterocyclic amino groups], acylamino groups, aminocarbonyls Amino group, aliphatic oxycarbonylamino group (typically alkoxycarbonylamino group), aryloxycarbonylamino group, sulfamoylamino group, aliphatic (typically alkyl) or arylsulfonylamino group, aliphatic thio group ( Typical examples are alkylthio groups), aryl O group, sulfamoyl group, aliphatic (typically alkyl) or arylsulfinyl group, aliphatic (typically alkyl) or arylsulfonyl group, acyl group, aryloxycarbonyl group, aliphatic oxycarbonyl group (typically alkoxy) Carbonyl group), carbamoyl group, aryl or heterocyclic azo group, imide group, aliphatic oxysulfonyl group (typically alkoxysulfonyl group), aryloxysulfonyl group, halogen atom, hydroxyl group, nitro group, carboxyl group, sulfo group Each group may further have a substituent (for example, a substituent exemplified herein).

  Among these substituents, a halogen atom (a fluorine atom, a chlorine atom and a bromine atom are preferable, a chlorine atom and a bromine atom are more preferable), an alkyl group (a carbon number of 1 to 10 is preferable, and a carbon number of 1 to 1 is preferable). 6 is more preferable, C1-C4 is still more preferable, an alkoxy group (C1-C10 is preferable, C1-C6 is more preferable, C1-C4 is more preferable), an aryloxy group (phenoxy) Group, naphthoxy group is preferable, and phenoxy group is more preferable), aryl group (phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2 -A phenanthryl group is preferable, and a phenyl group, a 1-naphthyl group, and a 2-naphthyl group are more preferable.

  X in the general formula (1) is preferably a hydrogen atom, an unsubstituted alkyl group, a halogenated alkyl group, an aralkyl group, an alkoxyaralkyl group, an alkoxyalkyl group, an unsubstituted aryl group, a halogenated aryl group, or an alkylaryl. A group, an alkyloxyaryl group, and an aryloxyaryl group.

  Specific examples of the monomer capable of forming the unit structure represented by the general formula (1) by polymerization are shown as A-1 to A-27 below, but can be employed in the present invention. The monomer is not limited to these specific examples.

  When the thermoplastic resin used in the present invention is synthesized by copolymerization, a monomer capable of forming a unit structure represented by the general formula (1) is used in an amount of 3 to 70% by mass in the monomer composition. Is preferably used, more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass. As the monomer capable of forming the unit structure represented by the general formula (1), only one type may be used, or two or more types may be used in combination. In the present invention, when only one type of monomer is used as a monomer capable of forming the structural unit of the general formula (1), only monomers capable of forming only a structural unit in which R is a substituted or unsubstituted alkyl group are selected. The present invention can sufficiently achieve the object of the present invention, even when only monomers capable of forming only structural units in which R is a substituted or unsubstituted aryl group are used. .

<Copolymerizable monomer>
The thermoplastic resin used by this invention can be manufactured by copolymerizing another monomer with the monomer which can form the unit structure represented by General formula (1) by superposing | polymerizing. As such other monomers, those described in Polymer Handbook 2nd ed., J. Brandrup, Wiley lnterscience (1975) Chapter 2 Page 1 to 483 can be used.

  Specifically, for example, styrene derivatives, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylcarbazole, acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers , Vinyl esters, dialkyl itaconates, dialkyl esters of the above fumaric acid, monoalkyl esters, and the like.

  Examples of the styrene derivative include styrene, 2,4,6-tribromostyrene, 2-phenylstyrene, 4-chlorostyrene and the like.

  Examples of the acrylic esters include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, tert-butyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, trimethylolpropane monoacrylate, and benzyl acrylate. , Benzyl methacrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, and the like.

  Examples of the methacrylic acid esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, tert-butyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, trimethylolpropane monomethacrylate, benzyl methacrylate, methoxy Examples include benzyl methacrylate, furfuryl methacrylate, and tetrahydrofurfuryl methacrylate.

  Examples of the acrylamides include acrylamide, N-alkylacrylamide (alkyl group having 1 to 3 carbon atoms, such as methyl group, ethyl group, propyl group), N, N-dialkylacrylamide (alkyl group having 1 carbon atom). ~ 6), N-hydroxyethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like.

  Examples of the methacrylamides include methacrylamide, N-alkyl methacrylamide (alkyl groups having 1 to 3 carbon atoms, such as methyl, ethyl, propyl), N, N-dialkyl methacrylamide (as alkyl groups). Are those having 1 to 6 carbon atoms), N-hydroxyethyl-N-methylmethacrylamide, N-2-acetamidoethyl-N-acetylmethacrylamide and the like.

  Examples of the allyl compound include allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate), allyloxyethanol Etc.

  Examples of the vinyl ethers include alkyl vinyl ethers (alkyl groups having 1 to 10 carbon atoms, such as hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl Examples include -2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, and tetrahydrofurfuryl vinyl ether.

  Examples of the vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl lactate Vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate, and the like.

  Examples of the dialkyl itaconates include dimethyl itaconate, diethyl itaconate, and dibutyl itaconate. Examples of the dialkyl esters or monoalkyl esters of the fumaric acid include dibutyl fumarate.

  In addition, crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile, maleilonitrile, and the like can also be mentioned.

  Examples of the monomer that can be copolymerized with the monomer capable of forming the unit structure represented by the general formula (1) by polymerization include the following, but can be employed in the present invention. The monomer is not limited to these specific examples. In the following, n represents an integer of 1 or more.

  When synthesizing the thermoplastic resin used in the present invention by copolymerization, it is preferable to use the monomer capable of copolymerization of 30 to 97% by mass in the monomer composition, and use 50 to 90% by mass. It is more preferable to use 60 to 85% by mass.

［Ｒ¹¹、Ｒ¹²、Ｒ¹³、Ｒ¹⁴、Ｒ¹⁵、Ｒ¹⁶は、それぞれ独立に水素原子、置換または無置換のアルキル基、置換または無置換のアルケニル基、置換または無置換のアルキニル基、あるいは、置換または無置換のアリール基を表す。］、−ＳＯ₃Ｈ、−ＯＳＯ₃Ｈ、−ＣＯ₂Ｈ、−ＯＨ、−Ｓｉ（ＯＲ¹⁷）_nＲ¹⁸ _n［Ｒ¹⁷、Ｒ¹⁸はそれぞれ独立に水素原子、置換または無置換のアルキル基、置換または無置換のアルケニル基、置換または無置換のアルキニル基、あるいは、置換または無置換のアリール基を表し、ｎは１〜３の整数を表す。］ <Functional group>
The thermoplastic resin used in the present invention preferably has one or more functional groups selected from the following. The functional group may be present in at least one position of the polymer terminal or in the side chain.

[R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, Alternatively, it represents a substituted or unsubstituted aryl group. _{], - SO 3 H, -OSO} 3 H, -CO 2 H, -OH, -Si (OR 17) n R 18 n [R 17, R 18 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group Represents a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group, and n represents an integer of 1 to 3. ]

The preferred ranges of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ are the following ranges.
The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and examples thereof include a methyl group, an ethyl group, and an n-propyl group. Substituted alkyl groups include, for example, aralkyl groups. The aralkyl group preferably has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and examples thereof include a benzyl group and a p-methoxybenzyl group. The alkenyl group preferably has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and examples thereof include a vinyl group and a 2-phenylethenyl group. The alkynyl group preferably has 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, and examples thereof include an ethynyl group and a 2-phenylethynyl group. The aryl group preferably has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and examples thereof include a phenyl group, a 2,4,6-tribromophenyl group, and a 1-naphthyl group. The aryl group herein includes a heteroaryl group. As substituents for alkyl groups, alkenyl groups, alkynyl groups, and aryl groups, in addition to these alkyl groups, alkenyl groups, alkynyl groups, and aryl groups, halogen atoms (eg, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms) And alkoxy groups (for example, methoxy group, ethoxy group). R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ are particularly preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom.
Preferable ranges of R ¹⁷ and R ¹⁸ are the same as those of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ . n is preferably 3.

、−ＳＯ₃Ｈ、−ＣＯ₂Ｈ、または−Ｓｉ（ＯＲ¹⁵）_m1Ｒ¹⁶ _3-m1であり、より好ましくは、

または−ＣＯ₂Ｈである。 Among these functional groups, preferably

A -SO ₃ H, -CO ₂ H or _{^{-Si (OR 15), m1 R}} 16 3-m1, more preferably,

Or a -CO ₂ H.

  In the thermoplastic resin used in the present invention, the average number of the functional groups is preferably from 0.1 to 20, more preferably from 0.5 to 10, more preferably from 1 to 5 per polymer chain. It is particularly preferred. If the content of the functional group is 20 or less on average per polymer chain, the thermoplastic resin tends to prevent the increase in viscosity and gelation in the solution state due to coordination with a plurality of inorganic fine particles. is there. Moreover, if the number of average functional groups per polymer chain is 0.1 or more, the inorganic fine particles tend to be dispersed stably.

<Specific examples of thermoplastic resin>
The following table lists preferred specific examples of thermoplastic resins that can be used in the present invention. A thermoplastic resin can be produced by mixing and copolymerizing the types of monomers described in the table at a mass ratio described in the table. However, the thermoplastic resin that can be used in the present invention is not limited to these.

  These thermoplastic resins may be used alone or in combination of two or more.

<Properties of thermoplastic resin>
The number average molecular weight of the thermoplastic resin used in the present invention is preferably 10,000 to 200,000, more preferably 10,000 to 150,000, and 10,000 to 100,000. Is more preferably 20,000 to 100,000, still more preferably 40,000 to 100,000, and particularly preferably 70,000 to 100,000. When the weight average molecular weight of the thermoplastic resin is 200,000 or less, molding processability tends to be improved, and when it is 10,000 or more, mechanical strength tends to be improved. In particular, by increasing the molecular weight, it is possible to effectively prevent damage to the molded product when the organic-inorganic composite material is removed from the mold after molding.

  The glass transition temperature of the thermoplastic resin used in the present invention is preferably 80 ° C to 400 ° C, and more preferably 130 ° C to 380 ° C. If a resin having a glass transition temperature of 80 ° C. or higher is used, an optical article having sufficient heat resistance can be easily obtained, and if a resin having a glass transition temperature of 400 ° C. or lower is used, molding tends to be easily performed.

  When the difference between the refractive index of the thermoplastic resin and the refractive index of the inorganic fine particles is large, Rayleigh scattering is likely to occur, so that the amount of fine particles that can be combined while maintaining transparency is reduced. If the thermoplastic resin has a refractive index of about 1.48, a transparent molded article having a refractive index of 1.60 can be provided. However, in order to realize a refractive index of 1.65 or more, it is used in the present invention. The refractive index of the thermoplastic resin obtained is preferably 1.55 or more, more preferably 1.57 or more, and even more preferably 1.58 or more. These refractive indexes are values at 22 ° C. and a wavelength of 589 nm.

  The thermoplastic resin used in the present invention preferably has a light transmittance in terms of 1 mm thickness at a wavelength of 589 nm of 70% or more, more preferably 80% or more, and even more preferably 85% or more.

[Inorganic fine particles]
There are no particular limitations on the inorganic fine particles used in the organic-inorganic composite material of the present invention. For example, the fine particles described in JP-A Nos. 2002-241612, 2005-298717, 2006-70069, etc. are used. be able to.

Specifically, fine oxide particles (aluminum oxide, titanium oxide, niobium oxide, zirconium oxide, zinc oxide, magnesium oxide, tellurium oxide, yttrium oxide, indium oxide, tin oxide, etc.), double oxide fine particles (lithium niobate, Potassium niobate, lithium tantalate, etc.), sulfide fine particles (zinc sulfide, cadmium sulfide, etc.), other semiconductor crystal fine particles (zinc selenide, cadmium selenide, zinc telluride, cadmium telluride, etc.), or LiAlSiO ₄ , PbTiO ₃ , Sc ₂ W ₃ O ₁₂ , ZrW ₂ O ₈ , AlPO ₄ , Nb ₂ O ₅ , LiNO ₃ or the like can be used. Among these, it is preferable to use at least one selected from the group consisting of zirconium oxide, zinc oxide, tin oxide and titanium oxide.

  Two or more kinds of inorganic fine particles may be used in combination.

  The inorganic fine particles used in the present invention may be a composite of a plurality of components from the viewpoints of refractive index, transparency, stability, and the like. Also, inorganic fine particles can be doped with different elements for various purposes such as photocatalytic activity reduction and water absorption reduction, the surface layer is coated with different metal oxides such as silica and alumina, silane coupling agents, titanate couplings. The surface may be modified with an agent, an aluminate coupling agent, an organic acid (such as carboxylic acids, sulfonic acids, phosphoric acids, phosphonic acids). Furthermore, these two or more types may be used in combination depending on the purpose.

  The refractive index of the inorganic fine particles used in the present invention is not particularly limited, but when the organic-inorganic composite material of the present invention is used in an optical article that requires a high refractive index, the inorganic fine particles have a high refractive index characteristic. It is preferable. In this case, the refractive index of the inorganic fine particles used is preferably 1.9 to 3.0 at 22 ° C. and a wavelength of 589 nm, more preferably 2.0 to 2.7, and particularly preferably 2.1. ~ 2.5. If the refractive index of the fine particles is 3.0 or less, the difference in refractive index from the resin is relatively small, so that Rayleigh scattering tends to be easily suppressed. If the refractive index is 1.9 or more, the effect of increasing the refractive index tends to be easily obtained.

  The refractive index of the inorganic fine particles is obtained by, for example, molding a composite compounded with the thermoplastic resin used in the present invention into a transparent film, and measuring the refractive index with an Abbe refractometer (for example, “DM-M4” manufactured by Atago Co., Ltd.). It can be estimated by a method of calculating from the refractive index of only the resin component separately measured or a method of calculating the refractive index of the fine particles by measuring the refractive index of the fine particle dispersion having different concentrations.

If the number average particle size of the inorganic fine particles used in the present invention is too small, the characteristics specific to the substance constituting the fine particles may change. Conversely, if the number average particle size is too large, the effect of Rayleigh scattering is significant. Thus, the transparency of the organic-inorganic composite material may be extremely reduced. Therefore, the lower limit of the number average particle diameter of the inorganic fine particles used in the present invention is preferably 1 nm or more, more preferably 2 nm or more, further preferably 3 nm or more, and the upper limit is preferably 15 nm or less, more preferably 10 nm. Hereinafter, it is more preferably 7 nm or less. That is, the number average particle diameter of the inorganic fine particles in the present invention is preferably 1 nm to 15 nm, more preferably 2 nm to 10 nm, and particularly preferably 3 nm to 7 nm.
The inorganic fine particles used in the present invention desirably satisfy the above average particle size and have a narrow particle size distribution. There are various ways of defining such monodisperse particles. For example, the numerical value ranges described in JP-A-2006-160992 also apply to the preferable particle size distribution range of the fine particles used in the present invention. .
Here, the above-mentioned number average particle diameter can be measured by, for example, an X-ray diffraction (XRD) apparatus or a transmission electron microscope (TEM).

The method for producing inorganic fine particles used in the present invention is not particularly limited, and any known method can be used.
For example, desired oxide fine particles can be obtained by using a metal halide or an alkoxy metal as a raw material and hydrolyzing in a reaction system containing water. Details of this method are described in, for example, Japanese Journal of Applied Physics, 37, 4603-4608 (1998), or Langmuir, 16: 1, 241-246 (2000). ing.

Further, as a method other than the method of hydrolyzing in water, a method of preparing inorganic fine particles in an organic solvent or an organic solvent in which the thermoplastic resin in the present invention is dissolved may be employed. In this case, various surface treatment agents (silane coupling agents, aluminate coupling agents, titanate coupling agents, organic acids (carboxylic acids, sulfones, phosphonic acids, etc.)) may be allowed to coexist as necessary. Good.
Examples of the solvent used in these methods include acetone, 2-butanone, dichloromethane, chloroform, toluene, ethyl acetate, cyclohexanone, anisole and the like. These may be used alone or as a mixture of two or more.

  As a method for synthesizing inorganic fine particles, in addition to the above, various general fine particle synthesizing methods described in, for example, JP-A-2006-70069 and the like, such as a method of producing by a vacuum process such as a molecular beam epitaxy method or a CVD method. Can be mentioned.

  The content of the inorganic fine particles in the organic-inorganic composite material of the present invention is preferably 20 to 95% by mass, more preferably 25 to 70% by mass, particularly 30 to 60% by mass from the viewpoint of transparency and high refractive index. preferable.

[Additive]
In the present invention, in addition to the thermoplastic resin and the inorganic fine particles, various additives may be appropriately blended from the viewpoint of uniform dispersibility, flowability during molding, mold release, weather resistance, and the like. For example, a surface treatment agent, a plasticizer, an antistatic agent, a dispersant, a release agent, and the like can be given. In addition to the thermoplastic resin, a resin having no functional group may be added, and there is no particular limitation on the type of such a resin. However, the optical properties, thermophysical properties, and molecular weights of the thermoplastic resin are the same. What has is preferable.
Although the blending ratio of these additives varies depending on the purpose, it is preferably 0 to 50% by mass and preferably 0 to 30% by mass with respect to the total amount of the inorganic fine particles and the thermoplastic resin. More preferably, it is particularly preferably 0 to 20% by mass.

<Surface treatment agent>
In the present invention, as described later, when inorganic fine particles dispersed in water or an alcohol solvent are mixed with a thermoplastic resin, the objective is to improve the extractability or substitution into an organic solvent, and the uniform dispersibility to the thermoplastic resin. Depending on various purposes such as increasing the water absorption, decreasing the water absorption of the fine particles, or increasing the weather resistance, a fine particle surface modifier other than the thermoplastic resin may be added. It is preferable that the weight average molecular weight of this surface treating agent is 50-50000, More preferably, it is 100-20000, More preferably, it is 100-10000.

As said surface treating agent, what has a structure represented by following General formula (2) is preferable.
General formula (2)
AB

  In the general formula (2), A represents a functional group capable of forming an arbitrary chemical bond with the surface of the inorganic fine particles in the present invention, and B represents compatibility or reactivity with the resin matrix mainly composed of the resin in the present invention. It represents a monovalent group or polymer having 1 to 30 carbon atoms. Here, examples of the “chemical bond” include a covalent bond, an ionic bond, a coordination bond, a hydrogen bond, and the like.

Preferred examples of the group represented by A are the same as those described above as the fine particle-binding functional group introduced into the thermoplastic resin of the present invention.
On the other hand, the chemical structure of B is preferably the same or similar to the chemical structure of the thermoplastic resin that is the main component of the resin matrix from the viewpoint of compatibility. In the present invention, from the viewpoint of increasing the refractive index, it is preferable that the chemical structure of B has an aromatic ring together with the thermoplastic resin.

Examples of the surface treating agent preferably used in the present invention include, for example, p-octylbenzoic acid, p-propylbenzoic acid, acetic acid, propionic acid, cyclopentanecarboxylic acid, dibenzyl phosphate, monobenzyl phosphate, diphenyl phosphate, diphosphate phosphate. -α-naphthyl, phenylphosphonic acid, phenylphosphonic acid monophenyl ester, KAYAMER PM-21 (trade name; manufactured by Nippon Kayaku Co., Ltd.), KAYAMER PM-2 (trade name; manufactured by Nippon Kayaku Co., Ltd.), benzenesulfonic acid, Examples include, but are not limited to, naphthalene sulfonic acid, paraoctylbenzene sulfonic acid, and silane coupling agents described in JP-A-5-221640, JP-A-9-100111, and JP-A-2002-187721. is not.
These surface treatment agents may be used alone or in combination of two or more.
The total amount of the surface treatment agent added is preferably 0.01 to 2 times, more preferably 0.03 to 1 time, and more preferably 0.05 to 0 times in terms of mass with respect to the inorganic fine particles. It is particularly preferable that the ratio is 5 times.

<Plasticizer>
When the glass transition temperature of the thermoplastic resin in the present invention is high, molding of the organic-inorganic composite material may not always be easy. For this reason, a plasticizer may be used to lower the molding temperature of the organic-inorganic composite material of the present invention. When the plasticizer is added, the addition amount is preferably 1 to 50% by mass of the total amount of the organic-inorganic composite material, more preferably 2 to 30% by mass, and 3 to 20% by mass. Is particularly preferred.
The plasticizer that can be used in the present invention needs to be considered in total, such as compatibility with the resin, weather resistance, and plasticizing effect, and since the optimal plasticizer depends on other materials, it cannot be said unconditionally, From a viewpoint, what has an aromatic ring is preferable, and what has a structure represented by following General formula (3) can be mentioned as a typical example.

（式中、Ｂ¹およびＢ²は炭素数６〜１８のアルキル基またはアリールアルキル基を表し、ｍは０または１を表す。Ｘは、下記の２価の結合基のうちいずれかを表す。）

(In the formula, B ¹ and B ² represent an alkyl group or arylalkyl group having 6 to 18 carbon atoms, m represents 0 or 1, and X represents one of the following divalent linking groups. )

In the compound represented by the general formula (3), B ¹ and B ² can be selected from any alkyl group or arylalkyl group within the range of 6 to 18 carbon atoms. If the number of carbon atoms is less than 6, the molecular weight may be too low to boil at the melting temperature of the polymer and generate bubbles. Moreover, when carbon number exceeds 18, compatibility with a polymer may worsen and an addition effect may become inadequate.

Specific examples of B ¹ and B ² include direct n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tetradecyl group, n-hexadecyl group, n-octadecyl group and the like. Examples thereof include a chain alkyl group, a branched alkyl group such as a 2-hexyldecyl group and a methyl branched octadecyl group, and an arylalkyl group such as a benzyl group and a 2-phenylethyl group. Specific examples of the compound represented by the general formula (3) include the following compounds, among which W-1 (trade name “KP-L155” manufactured by Kao Corporation) is preferable.

<Antistatic agent>
In order to adjust the charged voltage of the organic-inorganic composite material of the present invention, an antistatic agent can be added. In the organic-inorganic composite material of the present invention, the inorganic fine particles added for the purpose of improving optical characteristics may contribute to the antistatic effect which is another effect. In the case of adding an antistatic agent, an anionic antistatic agent, a cationic antistatic agent, a nonionic antistatic agent, a zwitterionic antistatic agent, a polymeric antistatic agent, or a charging fine particle may be mentioned. Two or more types may be used in combination. Examples thereof include compounds described in JP2007-4131A and JP2003201396A.
The addition amount of the antistatic agent varies, but is preferably 0.001 to 50% by mass, more preferably 0.01 to 30% by mass, and particularly preferably 0.1 to 10% by mass of the total solid content. % By mass.

<Others>
In addition to the above components, a known release agent such as modified silicone oil is added for the purpose of improving moldability, and hindered phenol, amine, phosphorus, and thioether are used for the purpose of improving light resistance and thermal degradation. A known degradation inhibitor such as a system may be appropriately added. When these are blended, the content is preferably about 0.1 to 5% by mass with respect to the total solid content of the organic-inorganic composite material.

[Method for producing organic-inorganic composite material]
The organic-inorganic composite material of the present invention can be produced by mixing components such as a thermoplastic resin and inorganic fine particles.
Since the inorganic fine particles used in the present invention have a relatively small particle size and high surface energy, it is difficult to re-disperse when isolated as a solid. Therefore, the inorganic fine particles are preferably mixed with the thermoplastic resin in a state of being dispersed in a solution to form a stable dispersion. As a preferred method for producing a composite material, (1) inorganic particles are surface-treated in the presence of the surface treatment agent, the surface-treated inorganic fine particles are extracted into an organic solvent, and the extracted inorganic fine particles are converted into the thermoplastic resin. A method for producing a composite material of inorganic fine particles and a thermoplastic resin by uniformly mixing with a resin, (2) inorganic fine particles by uniformly mixing both using a solvent capable of uniformly dispersing or dissolving both the inorganic fine particles and the thermoplastic resin And a method for producing a composite material of thermoplastic resin.

In the case of producing a composite material of inorganic fine particles and thermoplastic resin by the method (1) above, water-insoluble such as toluene, ethyl acetate, methyl isobutyl ketone, chloroform, dichloroethane, dichloroethane, chlorobenzene, methoxybenzene, etc. as an organic solvent These solvents are used. The surface treatment agent used for extraction of the fine particles into the organic solvent and the thermoplastic resin may be the same or different, but the surface treatment agent preferably used is described above Those described in the section of> are mentioned.
When mixing the inorganic fine particles extracted into the organic solvent and the thermoplastic resin, additives such as a plasticizer, a release agent, or another type of polymer may be added as necessary.

  In the case of the above (2), the solvent is hydrophilic such as dimethylacetamide, dimethylformamide, dimethylsulfoxide, benzyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, t-butanol, acetic acid, propionic acid, etc. Preferably, a polar solvent alone or mixed solvent, or a mixed solvent of chloroform, dichloroethane, dichloromethane, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, chlorobenzene, methoxybenzene or the like and a polar solvent mentioned above is preferably used. . At this time, a dispersing agent, a plasticizer, a release agent, or another type of polymer may be added as necessary in addition to the above-described thermoplastic resin. When using fine particles dispersed in water / methanol, add a hydrophilic solvent that has a higher boiling point than water / methanol and dissolve the thermoplastic resin, and then concentrate the water / methanol to disperse the fine particles. After replacing the liquid with a polar organic solvent, it is preferable to mix with the resin. At this time, the surface treatment agent may be added.

  The solution of the organic-inorganic composite material obtained by the above methods (1) and (2) can be cast as it is to obtain a transparent molded body. In the present invention, the solution is particularly concentrated, freeze-dried, Alternatively, after removing the solvent by a method such as reprecipitation from a suitable poor solvent, the powdered solid is preferably molded by a known method such as injection molding or compression molding. At this time, the powdered organic-inorganic composite material of the present invention can be processed into a molded article such as a lens by directly heating, melting, or compressing, but once a certain weight and shape are obtained by a method such as an extrusion method. After forming the preform (precursor) having the optical article such as a lens, the preform can be deformed by compression molding. In this case, the preform can have an appropriate curvature in order to efficiently create the target shape.

  The organic-inorganic composite material may be used as a master batch by mixing with other resins.

[Optical article]
The optical article of the present invention can be produced by molding the organic-inorganic composite material of the present invention described above. As the optical article of the present invention, those showing the above-described refractive index and optical characteristics in the description of the organic-inorganic composite material are useful.
As the optical article of the present invention, a high refractive index optical article having a maximum thickness of 0.1 mm or more is particularly useful. It is preferably applied to an optical article having a thickness of 0.1 to 5 mm, and particularly preferably applied to a transparent article having a thickness of 1 to 3 mm.
These thick molded bodies are usually difficult to remove by the solvent casting method because the solvent is difficult to remove, but by using the organic-inorganic composite material of the present invention, molding is easy and complex shapes such as aspherical surfaces can be easily formed. The optical article having good transparency can be obtained while utilizing the high refractive index characteristics of the fine particles.

  The optical article using the organic-inorganic composite material of the present invention is not particularly limited as long as it is an optical article using the excellent optical properties of the organic-inorganic composite material of the present invention. It is also possible to use it for a transmissive optical article (so-called passive optical article). Functional devices including such optical articles include various display devices (liquid crystal displays, plasma displays, etc.), various projector devices (OHP, liquid crystal projectors, etc.), optical fiber communication devices (optical waveguides, optical amplifiers, etc.), cameras, videos, etc. The imaging device is exemplified. Examples of the passive optical article in such an optical functional device include a lens, a prism, a prism sheet, a panel, a film, an optical waveguide, an optical disc, an LED sealant, and the like.

The optical article using the organic-inorganic composite material of the present invention is particularly suitable for a lens substrate. The lens substrate manufactured using the organic-inorganic composite material of the present invention has both light transmittance and light weight, and is excellent in optical properties. Further, the refractive index of the lens substrate can be arbitrarily adjusted by appropriately adjusting the type of monomer constituting the organic-inorganic composite material and the amount of inorganic fine particles to be dispersed.
The “lens substrate” in the present invention means a single member capable of exhibiting a lens function. A film or a member can be provided on the surface or the periphery of the lens substrate according to the use environment or application of the lens. For example, a protective film, an antireflection film, a hard coat film, or the like can be formed on the surface of the lens substrate. Further, the periphery of the lens base material can be fitted and fixed to a base material holding frame or the like. However, these films and frames are members added to the lens base material referred to in the present invention, and are distinguished from the lens base material itself referred to in the present invention.

  When the lens substrate in the present invention is used as a lens, the lens substrate itself of the present invention may be used alone as a lens, or may be used as a lens with a film or a frame added as described above. . The type and shape of the lens using the lens substrate of the present invention are not particularly limited. The lens substrate of the present invention is, for example, an eyeglass lens, an optical device lens, an optoelectronic lens, a laser lens, a pickup lens, an imaging lens (an in-vehicle camera lens, a portable camera lens, a digital camera lens, etc .; (Including various known imaging lenses such as zoom lenses and positive / negative power lenses), OHP lenses, microlens arrays, and the like).

  The features of the present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Analysis and Evaluation Method]
(1) Observation with Transmission Electron Microscope (TEM) It was carried out with an H-9000UHR transmission electron microscope (acceleration voltage 200 kV, degree of vacuum at the time of observation of about 7.6 × 10 ⁻⁹ Pa) manufactured by Hitachi, Ltd. .
(2) Measurement of light transmittance A resin having a thickness of 1.0 mm was prepared by molding a resin to be measured, and light having a wavelength of 589 nm was measured with a UV-visible absorption spectrum measuring apparatus UV-3100 (manufactured by Shimadzu Corporation).
(3) Refractive index measurement Light having a wavelength of 589 nm was measured with an Abbe refractometer (DR-M4 manufactured by Atago Co., Ltd.).
(4) Heat resistance (glass transition temperature)
It measured with the differential scanning calorimeter DSC7200 (made by SII nanotechnology Co., Ltd.).

[Preparation of materials]
(1) Synthesis of titania fine particles While stirring a 0.1 mol / L titanyl sulfate aqueous solution, a 1.5 mol / L sodium carbonate aqueous solution having the same volume was added dropwise at room temperature over 10 minutes. The white ultrafine particle suspension thus obtained was centrifuged at 3500 rpm and purified by repeating the steps of removing the supernatant by decantation and washing with water. The white precipitate thus obtained was heated at 50 ° C. for about 1 hour with stirring and dispersing in 0.3 mol / L of dilute hydrochloric acid to obtain a transparent acidic hydrosol. This acidic hydrosol was ice-cooled, and an aqueous solution of sodium dodecylbenzenesulfonate was added to form a white precipitate, which was then extracted with toluene, dried and concentrated. From the XRD and TEM of this concentrated residue, it was confirmed that anatase-type titania fine particles (number average particle size was about 5 nm) were formed.

(2) Synthesis of zirconia fine particles A zirconium oxychloride solution having a concentration of 50 g / L was neutralized with a 48% aqueous sodium hydroxide solution to obtain a hydrated zirconium suspension. The suspension was filtered and then washed with ion exchanged water to obtain a hydrated zirconium cake. The cake was adjusted to a concentration of 15% by mass in terms of zirconia using ion-exchanged water as a solvent, placed in an autoclave, and hydrothermally treated at 150 ° C. and 150 ° C. for 24 hours to obtain a zirconia fine particle suspension. Formation of zirconia fine particles having a number average particle diameter of 5 nm was confirmed by TEM.

(3) Preparation of zirconia fine particle toluene dispersion The zirconia fine particle suspension synthesized in (2) above and a toluene solution in which p-propylbenzoic acid manufactured by Tokyo Kasei was dissolved were mixed and stirred at 50 ° C. for 8 hours. The toluene solution was extracted to prepare a zirconia fine particle toluene dispersion.
When other dispersants are used, they can be prepared by the same method.

(4) Synthesis of resin In a 500 ml three-necked flask equipped with a reflux condenser and a gas introduction cock, 15.0 g of N-methylmaleimide (A-2), 84.0 g of styrene (B-1), 2-carboxyethyl acrylate ( C-3) After adding 1.0 g and N, N′-dimethylacetamide 233.3 g and substituting with nitrogen twice, 0.5 g of V-601 (trade name) manufactured by Wako Pure Chemical Industries, Ltd. was used as an initiator. After adding and replacing with nitrogen twice, the mixture was heated at 80 ° C. for 3 hours under a nitrogen stream. After returning to room temperature, 100 ml of N, N′-dimethylacetamide was added, stirred for 10 minutes, poured into 5 L of methanol, and reprecipitated. The precipitate was collected by filtration, washed with a large amount of methanol, and vacuum-dried at 60 ° C. for 3 hours to obtain P-1 (yield 42%, number average molecular weight 43,000, weight average molecular weight 74,000). .
Other exemplified polymers can be prepared in a similar manner.

(5) Preparation of organic / inorganic composite material Toluene dispersion (zirconia: p-propylbenzoic acid = 10: 1) of the zirconia fine particles synthesized in (3) was used as resin P-1 and S-3103 manufactured by Matsumura Oil Research Co., Ltd. The product was added dropwise to a toluene solution in which (trade name) was dissolved over 5 minutes, stirred for 1 hour, and then the solvent was removed to obtain an organic-inorganic composite material as powder.
Other organic-inorganic composite materials were prepared in the same manner.

[Manufacture of optical components by thermoforming]
Each lens of Examples 1-10 and Comparative Examples 1-3 was manufactured in the following procedure. The types of inorganic fine particles used and the amounts used as inorganic components were as shown in Table 2. However, p-propylbenzoic acid is contained in an amount of 8.3% by mass and S-3103 is contained in an amount of 4.2% by mass, and the remainder is occupied by the resin. In Comparative Example 1, polymethyl methacrylate (manufactured by Aldrich, product number 44,574-6, molecular weight 350,000) was used as the resin, and in Comparative Example 2, Q-1 (the constituent monomer was 95% by mass of B-12, C-2 was 5 mass%, and the number average molecular weight was 27000). In Comparative Example 3, polystyrene (manufactured by Aldrich, product number 18,242-7, molecular weight 280000) was used.
Each manufactured organic-inorganic composite material was heat-molded at 180 ° C. to prepare a molded article for lens having a thickness of 1 mm. At this time, the releasability from the mold was evaluated. The molded body was cut and the cross section was observed with a TEM to confirm whether the inorganic fine particles were uniformly dispersed in the thermoplastic resin. Further, light transmittance measurement and refractive index measurement were performed. These results are listed in Table 2 below. Thereafter, the lens molding was molded into a lens shape to obtain a lens as an optical component.

  As is apparent from Table 2, an optical component having a refractive index greater than 1.63, good dispersibility and transparency of inorganic fine particles, and heat resistance and moldability was obtained according to the present invention (Examples). 1-10). On the other hand, in Comparative Example 1 using polymethyl methacrylate, the inorganic fine particles cannot be uniformly dispersed because of low dispersibility, and the fine particles are aggregated, and the light transmittance is low. The refractive index could not be measured, and the heat resistance was low. In Comparative Example 2 using the comparative thermoplastic resin Q-1, the heat resistance was insufficient and the refractive index was low. Furthermore, in Comparative Example 3 using polystyrene as the resin, the inorganic fine particles cannot be uniformly dispersed due to low dispersibility, and the fine particles are aggregated, and the light transmittance is low. The refractive index could not be measured.

  In addition, as for the organic inorganic composite material of Examples 1-10, all have a withstand voltage in the range of -1.0-7.0 kV, and the volatile component at the time of hold | maintaining at 250 degreeC for 2 hours is 2 mass% or less. The saturated water absorption was 2% by mass or less. Moreover, the organic-inorganic composite materials of Examples 1 to 10 were able to accurately form the concave / convex lens shape with good productivity and in accordance with the shape of the mold.

  Furthermore, when the organic-inorganic composite materials of Examples 1 to 10 were used, no cracks or chips were found on the optical surface when taking out from the mold after heat molding. When Examples 6 to 8 were compared, in Example 6 having a low molecular weight, cracks or chippings having no practical problem were found in a part of the edge that was not an optical surface. In Example 8, which was suppressed to a part and had a high molecular weight, no cracks or chips were observed. In addition, when the organic-inorganic composite material of Example 2 or Example 10 was used, no cracks or chips were observed, and when the organic-inorganic composite material of Examples 1, 3-5, or 9 was used, It was about the same as 7.

  The optical component of the present invention includes an organic-inorganic composite material having both high refraction, light transmittance, light weight, and heat resistance. ADVANTAGE OF THE INVENTION According to this invention, the optical component which adjusted the refractive index arbitrarily can be provided comparatively easily. Therefore, the present invention is useful for providing a wide range of optical components such as a high refractive lens, and has high industrial applicability.

Claims (11)

An organic-inorganic composite material comprising inorganic fine particles having a number average particle diameter of 1 to 15 nm in a thermoplastic resin having at least one unit structure represented by the following general formula (1) .

[In General Formula (1), X represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. ]   The organic-inorganic composite material according to claim 1, wherein the thermoplastic resin has a refractive index of 1.57 or more at a wavelength of 589 nm.   The organic-inorganic composite material according to claim 1 or 2, wherein the thermoplastic resin has a number average molecular weight of 10,000 to 200,000. The organic-inorganic composite material according to any one of claims 1 to 3, wherein the thermoplastic resin contains a unit structure represented by the following general formula (1) in an amount of 3 to 70% by mass.

[In General Formula (1), X represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. ] The organic-inorganic composite material according to any one of claims 1 to 4, wherein the thermoplastic resin has one or more functional groups selected from the following.

[R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, Alternatively, it represents a substituted or unsubstituted aryl group. _{], - SO 3 H, -OSO} 3 H, -CO 2 H, -OH, -Si (OR 17) n R 18 n [R 17, R 18 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group Represents a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group, and n represents an integer of 1 to 3. ]   6. The organic-inorganic composite material according to claim 5, wherein the thermoplastic resin has an average of 0.1 to 20 functional groups per polymer chain.   The organic-inorganic composite material according to any one of claims 1 to 6, wherein the refractive index of the inorganic fine particles at a wavelength of 589 nm is in a range of 1.90 to 3.00.   The organic-inorganic composite material according to any one of claims 1 to 7, wherein the inorganic fine particles contain at least one selected from the group consisting of zirconium oxide, zinc oxide, tin oxide and titanium oxide. .   The refractive index at a wavelength of 589 nm of the organic-inorganic composite material is 1.63 or more, and the light transmittance in terms of 1 mm thickness at a wavelength of 589 nm is 70% or more. The organic-inorganic composite material according to one item.   The optical component comprised including the organic inorganic composite material as described in any one of Claims 1-9.   The optical component according to claim 10, wherein the optical component is a lens substrate.