WO2009113738A1

WO2009113738A1 - Organic-inorganic hybrid composition, transparent molding, optical component and lens

Info

Publication number: WO2009113738A1
Application number: PCT/JP2009/055549
Authority: WO
Inventors: Tatsuhiko Obayashi; Ryo Suzuki; Hiroaki Mochizuki; Osamu Sawanobori; Satoshi Yoneyama; Tetsuo Kawano; Ichiro Amimori; Haruhiko Miyamoto; Noriko Eiha; Seiichi Watanabe
Original assignee: Fujifilm Corporation
Priority date: 2008-03-13
Filing date: 2009-03-13
Publication date: 2009-09-17
Also published as: TW200946584A; JP2009221246A

Abstract

An organic-inorganic hybrid composition comprising inorganic fine particles and a thermoplastic resin, wherein the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 4 or more atoms.

Description

DESCRIPTION

ORGANIC-INORGANIC HYBRID COMPOSITION, TRANSPARENT MOLDING, OPTICAL COMPONENT AND LENS

TECHNICAL FIELD

The present invention relates to an organic-inorganic hybrid composition having excellent high refraction properties, transparency, lightweight properties and workability, and an optical component such as a lens substrate that is constructed to include the organic-inorganic hybrid composition (e.g., lenses to constitute eyeglasses, lenses for optical instruments, lenses for optoelectronics, lenses for lasers, lenses for pickups, lenses for in-vehicle cameras, lenses for portable cameras, lenses for digital cameras, lenses for OHP and microlens arrays) .

BACKGROUND ART

As compared with glass, resin has is advantageous in that it is lightweight and is excellent in impact resistance and shapability and that it is economical; and the recent tendency in the art of optical components such as lenses and others is toward replacement of optical glass with resin materials through improvement in high refractivity and transparency thereof.

For shaping resin, widely employed are various methods of an injection molding method of casting a resin melt into a mold and shaping it therein, an extrusion shaping method, a compression molding method, etc. In the methods, however, the flowability of resin is often problematic. For replacing optical glass with resin as mentioned above, a material with inorganic nanoparticles finely dispersed in a resin has been developed for the purpose of functionalizing the resin material to a higher degree so as to have high refractivity and good heat resistance (for example, see JP-A 2007-238929, JP-A 2003-73564 and JP-A 61-73754) ; but the flowability of the resulting resin material may worsen since inorganic nanoparticles are dispersed in the resin. For the purpose of enhancing the flowability or a resin material itself, generally employed is a method of adding a plasticizer to the resin or a method of lowering the molecular weight of the resin; however, these methods may often lower the heat resistance and the mechanical properties of the resin. Accordingly, it is desired to develop a technique of material having a high Tg and a high molecular weight and still having good flowability.

On the other hand, a method for obtaining a transparent composite composition is disclosed, in which an organic-inorganic hybrid composition is melt-extruded under high energy of at most 100 MJ/m³ (see JP-A 2006-131736) .

DISCLOSURE OF THE INVENTION

Kneading under high energy is problematic in obtaining high-quality optical components, owing to> resin coloration, impurities and the like to be caused by resin degradation under shearing heat; and as so mentioned in the above, it is desired to develop an organic-inorganic hybrid composition having high refractivity and good transparency and excellent in flowability.

The invention has been made in consideration of the current situation mentioned above, and its object is to provide an organic-inorganic hybrid composition having high refractivity and excellent transparency, in which inorganic fine particles are uniformly dispersed in a resin matrix with small kneading energy.

The present inventors have previously disclosed a technique relating to an organic-inorganic hybrid composition having high refractivity and excellent in transparency and having uniform dispersibility of inorganic fine particles therein (for example, see Patent Reference 1) , and have further investigated a technique of improving the flowability of the composition, and as a result, have found that when a thermoplastic resin having a specific structure is used in the composition, then the flowability of the composition can be significantly enhanced not detracting from the other properties thereof, and have completed the present invention described below. [1] An organic-inorganic hybrid composition comprising inorganic fine particles and a thermoplastic resin, wherein the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 4 or more atoms.

[2] The organic-inorganic hybrid composition according to [1], wherein the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 5 or more atoms.

[3] The organic-inorganic hybrid composition according to [2] , wherein the functional group is selected from the group consisting of

wherein R¹¹, R¹², R¹³ and R¹⁴ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or an atom or group capable of forming a salt; -SO₃H or a salt thereof, -OSO₃H or a salt thereof, -CO₂H or a salt thereof, -Si (OR¹⁵)_miR¹⁶ ₃-_mi wherein R¹⁵ and R¹⁶ independently represent hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or an atom or group capable of forming a salt; and ml represents an integer of 1 to 3. [4] The organic-inorganic hybrid composition according to any one of [1] to [3] , wherein the thermoplastic resin has a structural unit represented by the following formula (1) : Formula (1)

wherein R represents a hydrogen atom, a halogen atom or a methyl group; W represents a linking group having a chain length of 4 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups; and Z represents a functional group capable of bonding to the inorganic fine particles. [5] The organic-inorganic hybrid composition according to any one of [1] to [3], wherein the thermoplastic resin has a structural unit represented by the following formula (2) : Formula (2)

wherein R represents a hydrogen atom, a halogen atom or a methyl group; and L represents a linking group having a chain length of 2 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups.

[6] The organic-inorganic hybrid composition according to any one of [1] to [5] , wherein the functional group is contained in a range of from 0.1 to 20 on the average per one polymer chain of the thermoplastic resin.

[7] The organic-inorganic hybrid composition according to any one of [1] to [6], wherein the thermoplastic resin has a weight average molecular weight of 50,000 or more. [8] The organic-inorganic hybrid composition according to any one of [1] to [7] , wherein the inorganic fine particles have a number average particle size of from 1 to 20 nm. [9] The organic-inorganic hybrid composition according to any one of [1] to [8], wherein the inorganic fine particles contain zirconium oxide, tin oxide, zinc oxide or titanium oxide.

[10] The organic-inorganic hybrid composition according to any one of [1] to [9], wherein the composition of 1 mm thick has a light transmittance of 70% or more at a wavelength of 589 nm. ■ - ■

[11] The organic-inorganic hybrid composition according to any one of [1] to [10] , wherein the composition has a refractive index of 1.60 or more. [12] A transparent molding comprising the organic-inorganic hybrid composition of any one of [1] to [11] .

[13] An optical component comprising the organic-inorganic hybrid composition of any one of [1] to [11] . [14] A lens comprising the organic-inorganic hybrid composition of any one of [1] to [11] . The organic-inorganic hybrid composition of the invention has high refractive index and excellent transparency and can be produced by kneading and extrusion with a low energy supply. The organic-inorganic hybrid composition of the invention is easy to mold and favorable for producing high-quality optical components and lenses.

MODES FOR CARRYING OUT THE INVENTION

The organic-inorganic hybrid composition of the invention is described in detail below. The description of the constitutive elements described hereinafter is based on the representative embodiment of the invention, and the invention should not be limited to such an embodiment. In the description, the numerical range expressed by the wording "from a number to another number" means the range that falls between the former number indicating the lower limit of the range and the latter number indicating the upper limit thereof. [Organic-Inorganic Hybrid Composition]

The organic-inorganic hybrid composition of the invention comprises inorganic fine particles and a thermoplastic resin. The organic-inorganic hybrid composition is characterized by the fact that the the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 4 or more atoms . The organic-inorganic hybrid composition of the invention can be preferably used to produce the molding of the invention.

The organic-inorganic hybrid composition of the invention is preferable solid. Solvent content is preferably 5% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less, and it is most preferable to be solvent-free.

The organic-inorganic hybrid composition of the invention has a refractive index of preferably 1.60 or more, more preferably 1.65 or more, further preferably 1.67 or more, and particularly preferably 1.70 or more, at a wavelength of 589 nm.

The organic-inorganic hybrid composition of the invention has a light transmittance of preferably 70% or more, more preferably 75% or more, and particularly preferably 80% or more, at a wavelength of 589 nm in terms of the composition having a thickness of 1 mm. Further, the light transmittance at a wavelength of 405 nm in terms of the composition having a thickness of 1 mm is preferably 60% or more, more preferably 65% or more, and particularly preferably 70% or more. When the light transmittance at a wavelength of 589 nm in terms of the composition having a thickness of 1 mm is 70% or more, a lens substrate having further preferable properties is liable to obtain. The light transmittance in terms of 1 mm thickness conversion in the invention is a value measured as follows. An organic-inorganic hybrid composition is molded to prepare a substrate having a thickness of 1.0 mm, and a light transmittance of the substrate is measured with a UV-visible ray spectrometric device (UV-3100, a product of Shimadzu Corporation) .

The organic-inorganic hybrid composition of the invention has a glass transition temperature of preferably from 80 to 400°C, and more preferably from 90 to 380⁰C. Whentheglass transition temperature is 8O⁰C or higher, there is the tendency that sufficient heat resistance is liable to be obtained, and when the glass transition temperature is 400⁰C or lower, there is the tendency that it is liable to conduct processing. The thermoplastic resin and inorganic fine particles that are the essential constitutive components of the organic-inorganic hybrid composition of the invention are successively described below. The organic-inorganic hybrid composition of the invention may contain additives such as resins that do not satisfy the requirements of the invention, dispersants, plasticizers and release agents, other than those essential constitutive components. [Thermoplastic resin]

The thermoplastic resin used in the invention has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 4 or more atoms. (Basic skeleton of the thermoplastic resin)

A basic skeleton of the thermoplastic resin used in the invention is not particularly limited, and conventional resin skeletons such as poly (meth) acrylic acid ester, polystyrene, polyvinyl carbazole, polyester, polyarylate, polycarbonate, polyurethane, polyimide, polyester, polyether sulfone, polyether ketone and polythioether can be employed. A vinyl polymer, a polyacrylate and an aromatic group-containing polycarbonate are preferable, and a vinyl polymer is more preferable. (Functional group capable of forming a chemical bond with the inorganic fine particles)

The functional group capable of forming a chemical bond with the inorganic fine particles that is contained in the thermoplastic resin used in the invention is a functional group capable of forming a chemical bond with the inorganic fine particles. The "chemical bond" used herein includes a covalent bond, an ionic bond, a coordinate bond and a hydrogen bond. Where plural functional groups are present, those may form different chemical bonds with the inorganic fine particles, respectively. Whether a chemical bond can be formed is determined by whether the functional group of the thermoplastic resin can form a chemical bond with the inorganic fine particles when the thermoplastic resin and the inorganic fine particles are mixed in an organic solvent as described in the Examples described hereinafter. In the organic-inorganic hybrid composition of the invention, the functional groups of the thermoplastic resin all may form a chemical bond with the inorganic fine particles, and part thereof may form a chemical bond with the inorganic fine particles. The functional group capable of bonding to the inorganic fine particles has a function to stably disperse the inorganic fine particles in the thermoplastic resin by forming a chemical bond with the inorganic fine particles. The functional group capable of forming a chemical bond with the inorganic fine particles is not particularly limited in its structure so far as it can form a chemical bond with the inorganic fine particles . For example,

OR¹¹ OR¹³ -P-OR¹² —O-P-OR¹⁴

wherein R¹¹, R¹², R¹³ and R¹⁴ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or an atom or group capable of forming a salt; -SO₃H or a salt thereof, -OSO₃H or a salt thereof, -CO₂H or a salt thereof, -Si (OR¹⁵)_miR¹⁶ ₃-_mi wherein R¹⁵ and R¹⁶ independently represent hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or an atom or group capable of forming a salt; and ml represents an integer of 1 to 3.

Preferable range of R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ is as follows : The alkyl group has preferably from 1 to 30 carbon atoms, and more preferably from 1 to 20 carbon atoms, and examples thereof include a methyl group, an ethyl group and an n-propyl group. The substituted alkyl group includes an aralkyl group. The aralkyl group has preferably from 7 to 30 carbon atoms, and more preferably from 7 to 20 carbon atoms, and examples thereof include a benzyl group and a p-methoxybenzyl group. The alkenyl group has preferably from 2 to 30 carbon atoms, and more preferably from 2 to 20 carbon atoms, and examples thereof include a vinyl group and a 2-phenylethenyl group. The alkynyl group has preferably from 2 to 20 carbon atoms, and more preferably from 2 to 10 carbon atoms, and examples thereof include an ethynyl group and a 2-phenylethynyl group. The aryl group has preferably from 6 to 30 carbon atoms, and more preferably from 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 used herein includes a heteroaryl group. Examples of the substituent for the alkyl group, alkenyl group, alkynyl group and aryl group include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom) , and an alkoxy group (for example, a methoxy group and an ethoxy group) , in addition to those alkyl group, alkenyl group, alkynyl group and aryl group. R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are particularly preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom. m is preferably 3.

Among these functional groups, preferable are

-SO₃H or a salt thereof, -OSO₃H or a salt thereof, -CO₂H or a salt thereof, -Si (OR¹⁵)_miR¹⁶ ₃-_mi. More preferable are

OR¹¹ OR¹³ -P-OR¹² —O-P-OR¹⁴ O O and -CO₂H or a salt thereof. A method of introducing the functional group into the thermoplastic resin is not particularly limited. Examples of the method include a method of copolymerizing a monomer having a functional group, a method of copolymerizing a monomer having a functional group precursor site (for example, ester) and then converting into a functional group by a method such as hydrolysis, and a method of synthesizing a precursor resin having a reactive site such as a hydroxyl group, an amino group or an aromatic ring, and then introducing a functional group into the reactive site. A method of copolymerizing a monomer having a functional group is preferable:

(Structural Unit of the thermoplastic resin)

The thermoplastic resin used in the invention has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 4 or more atoms. Preferably, the thermoplastic resin used in the invention the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 5 or more atoms. The chain length is preferably 100 atoms or less, more preferably 40 atoms or less, still more preferably 20 atoms or less. When the chain length is 4 or more, the inorganic fine particles can be sufficiently dispersed in the thermoplastic resin by small kneading energy in preparation of the organic-inorganic hybrid composition of the invention whereby the transparency of the produced organic-inorganic hybrid composition is improved.

The thermoplastic resin used in the invention preferably has a structural unit represented by the following formula (1) : Formula (1)

In the formula (1) , R represents a hydrogen atom, a halogen atom or a methyl group, preferably a hydrogen atom or a methyl group. Z represents a functional group capable of bonding to the inorganic fine particles. Preferable functional groups are shown above.

W represents a linking group having a chain length of 4 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups.

The carbon number of the alkylene group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 5. Examples of the alkylene group include methylene group, ethylene group, propylene group, butylene group and pentylene group.

The carbon number of the arylene group is preferably 6 to 20, more preferably 6 to 15, still more preferably 6 to 10. Examples of the arylene group include phenylene group and naphthylene group.

The alkylnene group and the arylene group may have a substituent. Examples of the substituent include halogen ^atoms (for example, fluorine atom, chlorine atom, bromine atom, ■ iodine atom) , alkyl groups (for example, methyl group, ethyl group) , aryl groups (for example, phenyl group, naphthyl group) , alkenyl groups, alkynyl groups, cyano group, carboxyl group, alkoxycarbonyl groups (for example, methoxycarbonyl group) , aryloxycarbonyl group (for example, phenoxycarbonyl group) , substituted or unsubstituted carbamoyl groups (for example, carbamoyl group, N-phenylcarbamoyl, N,N-dimethylcarbamoyl groups) , alkylcarbonyl groups (for example, acetyl group) , arylcarbonyl groups (for example, benzoyl group) , nitro group, acylamino groups (for example, acetamide group, ethoxycarbonylamino group) , sulfoneamide groups (for example, methanesulfoneamide group) , imide groups (for example, succinimide group, phthalimide group) , imino groups (for example, benzylideneamino group) , alkoxy groups (for example, methoxy group) , aryloxy group (for example, phenoxy group) , acyloxy groups (for example, acetoxy group) , alkylsulfonyloxy groups (for example, methanesulfonyloxy group) , arylsulfonyloxy groups (for example, benzenesulfonyloxy group) , sulfo group, substituted or unsubstituted sulfamoyl groups (for example, sulfamoyl group, N-phenylsulfamoyl group) , alkylthio groups (for example, methylthio group), arylthio groups (for example, phenylthio group) , alkylsulfonyl groups (for example, methanesulfonyl group) , arylsulfonyl group (for example, benzenesulfonyl group) and heterocyclic rings . These substituents may be substituted by these substituents .

W may only consist of substituted or unsubstituted alkylene or substituted or unsubstituted arylene so long as these groups have a chain length of 4 or more atoms. W may be a linking group having a chain length of 4 or more atoms consisting of two or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups . The structures consisting of two groups are for example -OCO-, -C00-, -NHCO-, -CONH-, -SCS-, -CSS-, -O-alkylene, -CO-alkylene, -NH-alkylene, -S-alkylene, -CS-alkylene, -0-arylene, -CO-arylene, -NH-arylene, -S-arylene, -CS-arylene, alkylene-arylene, arylene-alkylene. Among them, -OCO- and -COO- are preferable.

The structures consisting of three groups are for example -OCO-alkylene, -COO-alkylene, -NHCO-alkylene, -CONH-alkylene, -SCS-alkylene, -CSS-alkylene, -OCO-arylene, -COO-arylene, -NHCO-arylene, -CONH-arylene, -SCS-arylene, -CSS-arylene, alkylene-0-alkylene, alkylene-CO-alkylene, alkylene-NH-alkylene, alkylene-S-alkylene, alkylene-CS-alkylene, alkylene-O-arylene, alkylene-CO-arylene, alkylene-NH-arylene, alkylene-S-arylene, alkylene-CS-arylene, alkylene-arylene-alkylene, arylene-O-alkylene, arylene-CO-alkylene, arylene-NH-alkylene, arylene-S-alkylene, arylene-CS-alkylene, arylene-O-arylene, arylene-CO-arylene, arylene-NH-arylene, arylene-S-arylene, arylene-CS-arylene and arylene-alkylene-arylene. Among them, -OCO-alkylnene and -COO-alkylene are preferable.

The group bonding to Z bonds is preferably an alkylene group or an arylene group, more preferably an alkylene group. The group bonding to the main chain is preferably -COO- or an arylene group, more preferably -COO- or a p-phenylene group. The preferable range of the chain length is described above. The thermoplastic resin used in the invention preferably has a structural unit represented by the following formula (2) : Formula (2)

In the formula (2), R represents a hydrogen atom, a halogen atom or a methyl group. They are all preferable.

L represents a linking group having a chain length of 2 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups. Examples of the linking group and their preferable range are shown in the above description for W in the formula (1) . The chain length of L is however 2 or more atoms, preferably 3 or more atoms. The number of atoms is preferably 100 or less, more preferably 40 or less, still more preferably 20 or less.

The structural units represented by the formula (1) or (2) are preferably included in the thermoplastic resin as a repeating unit. These repeating units can be formed by polymerizing a vinyl monomer corresponding to the structural unit represented by the formula (1) or (2) . The monomer can be represented by the following formula (I¹) or (2') : Formula (I¹)

In the formula (I¹), R represents a hydrogen atom, a halogen atom or a methyl group; W represents a linking group having a chain length of 4 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups; and Z is a functional group capable of bonding to the inorganic fine particles. Formula (2')

°

In the formula (2'), R represents a hydrogen atom, a halogen atom or a methyl group; and L represents a linking group having a chain length of 2 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups.

Preferable examples of the monomer represented by the formula (I¹) or (2') are described below, but the monomer that can be used in the invention is not limited to those.

(Synthesis of thermoplastic resin)

The thermoplastic resin used in the invention can be synthesized by copolymerizing a monomer represented by the formula (I¹) or the formula (2¹) and other copolymerizable monomer.

As the copolymerizable monomer, the monomers described in Polymer Handbook, 2nd ed., J. Brandrup, Wiley Interscience (1975) Chapter 2, pages 1-483 can be used.

Specifically, compounds having one addition-polymerizable unsaturated bond selected from styrene derivatives, 1-vinylnapphthalene, 2-vinylnaphthalene, vinylcarbazole, acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, dialkyl itaconates, dialkyl esters or monoalkyl esters of fumaric acid, and the like can be exemplified.

Examples of the styrene derivatives include styrene, 2, 4, 6-tribromostyrene and 2-phenylstyrene.

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

Examples of the acrylamides include acrylamide, N-alkyl acrylamide (as the alkyl group, an alkyl group having from 1 to 3 carbon atoms, such as a methyl group, an ethyl group and a propyl group), N, N-dialkyl acrylamide (as the alkyl group, an alkyl group having from 1 to 6 carbon atoms) , N-hydroxyethyl- N-methyl acrylamide and N-2-acetamideethyl-N-acetyl acrylamide .

Examples of the methacrylamides include methacrylamide, N-aklyl methacrylamide (as the alkyl group, an alkyl group having from 1 to 3 carbon atoms, such as a methyl group, an ethyl group and a propyl group), N, N-dialkyl methacrylamide (as the alkyl group, an alkyl group having from 1 to 6 carbon atoms) , N-hydroxyethyl-N-methyl methacrylamide and N-2-acetamideethyl-N-acetyl methacrylamide .

Examples of the allyl compounds include allyl esters (for example, allyl acetate, allyl caproate, allyl caprate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate and allyl lactate), and allyl oxyethanol.

Examples of the vinyl ethers include alkyl vinyl ethers

(as the alkyl, an alkyl having from 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, l-methyl-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 pivalate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl lactoate, vinyl-β-phenyl butylate and vinyl cyclohexyl carboxylate.

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

Besides those, crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile, maleironitrile and the like can be exemplified.

The thermoplastic resin (disperse polymer) used in the invention has a weight average molecular weight of preferably from 40, 000 to 500, 000, more preferably from 50, 000 to 300, 000, and particularly preferably from 50, 000 to 150,000. Where the weight average molecular weight of the thermoplastic resin is not larger than 500, 000, processability of the resin is improved, and where it is not less than 1, 000, an organic-inorganic hybrid composition having sufficient mechanical strength can be obtained.

The "weight average molecular weight" used herein is a molecular weight in terms of a polystyrene conversion by detection of a differential refractometer (solvent: hydroquinone) with GPC analyzer using columns of TSK gel GMHxL, TSK gel G4000HxL and TSK gel G2000HxL, products of Tosoh Corporation. In the thermoplastic resin used in the invention, the content of the functional group that bonds to the inorganic fine particles is preferably from 0.1 to 20, more preferably from 0.5 to 10, and particularly preferably from 1 to 5, on the average per one polymer chain. When the content of the functional group is 20 or less on the average per one polymer chain, the thermoplastic resin coordinates to plural inorganic fine particles, and there is the tendency that it is liable to prevent high viscosity increase and gelation from being generated in a solution state. Further, when the number of the functional group per one polymer chain is 0.1 or more on the average, there is the tendency that the inorganic fine particles are liable to be dispersed stably.

The thermoplastic resin used in the invention has a glass transition temperature of preferably from 80 to 400⁰C, and more preferably from 130 to 380⁰C. When a resin having a glass transition temperature of 8O⁰C or higher is used, an optical component having sufficient heat resistance is liable to be obtained. Further, when a resin having a glass transition temperature of 400⁰C or lower is used, there is the tendency that processing is liable to conduct.

Where difference between a refractive index of the thermoplastic resin and a refractive index of the inorganic fine particles is large, Rayleih scattering is liable to occur, and as a result, the amount of the fine particles that can be present in the composite while maintaining transparency is small . When the refractive index of the thermoplastic resin is about 1.48, a transparent molding having a refractive index in a level of 1.60 can be provided, but to realize a refractive index of 1.65 or more, the refractive index of the thermoplastic resin used in the invention is preferably 1.55 or more, and more preferably 1.58 or more. Those refractive indexes are a value at a wavelength of 589 nm at 22⁰C.

The thermoplastic resin used in the invention has a light transmittance of preferably 80% or more, more preferably 85% or more, and particularly preferably 88% or more, at a wavelength of 589 nm in terms of the resin having a thickness of 1 mm. (Examples of the thermoplastic resin) Preferable examples of the thermoplastic resin that can be used in the invention are described below, but the thermoplastic resin that can be used in the invention is not limited to those.

Polymer X Mn a/b (weight ratio)

CH₃ -CH₇-C-

P-3

OH 80000 99/1

CH₃ -CH₂-C-

P-5 80000 94/6

OH

Polymer _x ^ a/b (weight ratio)

P-IO 80000 98/2

9H₃

O

98000 98/2

O COOH

Polymer X Mn a/b (weight ratio)

P-15 80000 98/2

P-16 120000 99/1

Polymer Mn a/b (weight ratio)

CH₃

P-19 — CH₂-C- 75000 98/2

OH

P-26 (weight ratio)

P-27 (weight ratio)

weight ratio)

(weight ratio)

P-30 weight ratio)

P-31 (weight ratio)

P-32 -f CH-CH₂-JH -fcH₂-c4 O a/b=98/2 (weight ratio) Mn=200000

(weight ratio)

ratio)

6.3 (weight ratio)

(weight ratio)

[Inorganic Fine Particles]

The inorganic fine particles used in the invention include zirconium oxide fine particles, zinc oxide fine particles, titanium oxide fine particles, tin oxide fine particles and zinc sulfide fine particles, but the inorganic fine particles are not limited to those. Of those, metal oxide fine particles are particularly preferable. Above all, anyone selected from the group consisting of zirconium oxide, zinc oxide, tin oxide and titanium oxide is preferable, any one selected from the group consisting of zirconium oxide, tin oxide and titanium oxide is more preferable, and use of zirconium oxide fine particles having good visible region transparency and low photocatalyst activity are particularly preferable. In the invention, a composite of those inorganic materials may be used from the standpoints of refractive index, transparency and stability. Further, those fine particles may be particles which are doped with a different kind of an element, or whose surface layer is coated with a different kind of a metal oxide, such as silica or alumina, or is modified with a silane coupling agent, a titanate coupling agent or the like.

A method for producing the inorganic fine particles used in the invention is not particularly limited, and any conventional methods can be used. For example, the desired oxide fine particles can be obtained by using a metal halide or a metal alkoxide as a raw material, and hydrolyzing in a reaction system containing water.

Specifically, the following methods are known as a method of obtaining zirconium oxide fine particles or its suspension. A method of obtaining a zirconium oxide suspension by neutralizing an aqueous solution containing a zirconium salt with an alkali to obtain a hydrated zirconium, drying and burning the same, and then dispersing the same in a solvent; a method of obtaining a zirconium oxide suspension by hydrolyzing an aqueous solution containing a zirconium salt; a method of hydrolyzing an aqueous solution containing a zirconium salt to obtain a zirconium oxide suspension and then subjecting the same to ultrafiltration; a method of obtaining a zirconium oxide suspension by hydrolyzing a zirconium alkoxide; and a method of obtaining a zirconium oxide suspension by heat-treating an aqueous solution containing a zirconium salt under hydrothermal pressure. Any of those methods may be used.

Specifically, titanyl sulfate is exemplified as a raw material for the synthesis of titanium oxide nanoparticles, and a zinc salt such as zinc acetate and zinc nitrate is exemplified as a raw material for the synthesis of zinc oxide nanoparticles. Metal alkoxides such as tetraethoxysilane and titanium tetraisopropoxide are suitable as a raw material of the inorganic fine particles . A synthesis method of such inorganic fine particles includes a method described in, for example, Japanese Journal of Applied Physics, vol. 37, pages 4603-4608 (1998), or Langmuir, vol. 16, 1, pages 241-246 (2000) can be exemplified. In particular, where oxide nanoparticles are synthesized from a sol formation method, it is possible to use a procedure of passing through a precursor such as a hydroxide, and then dehydrocondensing or deflocculating the same with an acid or an alkali, thereby forming a hydrogel, as in the synthesis of titanium oxide nanoparticles using titanyl sulfate as a raw material. In such a procedure of passing through a precursor, the precursor is isolated and purified with an optional method such as filtration and centrifugal separation, and this is preferable in the point of purity of a final product. An appropriate surfactant such as sodium dodecylbenzene sulfonate

(abbreviated DBS) or dialkylsulfosuccinate monosodium salt (a product of Sanyo Chemical Industries, Ltd., trade name

"ELEMINOL JS-2") may be added to the hydrogel obtained, thereby insolubilizing sol particles in water and isolating the same. For example, the method described in Color Material, vol. 57, 6, pages 305-308 (1984) can be used.

Further, a method of preparing inorganic fine particles in an organic solvent can be exemplified as a method other than the method of hydrolyzing in water. In this case, the thermoplastic resin used in the invention may be dissolved in an organic solvent.

Examples of the solvent used in those methods include acetone, 2-butanone, dichloromethane, chloroform, toluene, ethyl acetate, cyclohexanone and anisole. Those may be in one kind alone or as mixtures of two or more kinds thereof.

Where the number average particle size of the inorganic fine particles used in the invention is too small, there is the possibility that properties inherent in materials constituting the fine particles vary, and on the other hand, where it is too large, there is the possibility that influence of Rayleigh scattering is remarkable, and transparency of the organic-inorganic hybrid composition extremely deteriorates. Therefore, the lower limit of the number average particle size of the inorganic fine particles used in the invention is preferably 1 nm or more, more preferably 2 nm or more, and further preferably 3 nm or more, and the upper limit thereof is preferably 20 nm or less, more preferably 15 nm or less, and further preferably 7 nm or less. Specifically, the number average particle size of the inorganic fine particles used in the invention is preferably from 1 to 20 nm, more preferably 2 to 15 nm and further preferably from 3 to 5 nm.

The "number average particle size" used herein can be measured with, for example, X ray diffraction (XRD) or transmission electron microscope (TEM) .

The inorganic fine particles used in the invention has a refractive index in a range of preferably from 1.9 to 3.0, more preferably from 2.0 to 2.7, and particularly preferably from 2.1 to 2.5, at a wavelength of 589 nm at 22°C. When the refractive index of the fine particles is 3.0 or less, difference in refractive index between the fine particles and the thermoplastic resin is not so large, and there is the tendency that it is liable to suppress Rayleigh scattering. Further, when the refractive index is 1.9 or more, there is the tendency that it is liable to achieve high refractive index.

The refractive index of the inorganic fine particles can be estimated by, for example, a method of measuring a refractive index of a composite as a transparent film, obtained by compositing the inorganic fine particles with the thermoplastic resin used in the invention with Abbe's refractometer (for example, DM-M4, a product of Atago) and converting the value from a refractive index of a resin component alone separately measured, or a method of measuring refractive indexes of dispersions of the fine particles, having different concentration, thereby calculating the refractive index of the fine particles.

The content of the inorganic fine particles in the organic-inorganic hybrid composition of the invention is preferably from 20 to 95% by mass, more preferably from 25 to 70% by mass, and particularly preferably from 30 to 60% by mass, from the standpoints of transparency and high refractive index. Further, the mass ratio of the inorganic fine particles to the thermoplastic resin (dispersed polymer) in the invention is preferably from 1:0.01 to- 1:100, more preferably from 1:0.05 to 1:10, and particularly preferably from 1:0.05 to 1:5, from the point of dispersibility. [Additives]

Other than the above-described thermoplastic resin and the inorganic fine particles, various additives may appropriately be blended with the organic-inorganic hybrid composition of the invention from the standpoints of uniform dispersibility, flowability when molding, release properties, weather resistance and the like. The blending proportion of those additives varies depending on the purpose, but is preferably from 0 to 50% by mass, more preferably from 0 to 30% by mass, and particularly preferably from 0 to 20% by mass, based on the sum of the inorganic fine particles and the thermoplastic resin. (Surface Treating Agent)

In the invention, in mixing the organic fine particles dispersed in water or an alcohol solvent with the thermoplastic resin as described hereinafter, a surface modifier of the fine particles, other than the above-described thermoplastic resin may be added according to various purposes such as the purpose of increasing extructability and replacement to an organic solvent, the purpose of increasing uniform dispersibility into the thermoplastic resin, the purpose of decreasing water absorption properties of the fine particles or the purpose of increasing weather resistance. The surface treating agent has a weight average molecular weight of preferably from 50 to 50,000, more preferably from 100 to 20,000, and further preferably from 200 to 10,000. The surface treating agent preferably has the structure represented by the following formula (3) . Formula (3)

A-B wherein A represents a functional group capable of forming a • chemical bond with the surface of the inorganic fine particles used in the invention, and B represents a monovalent group or polymer of from 1 to 30 carbon atoms having a compatibility or reactivity with a resin matrix comprising the thermoplastic resin used in the invention as a main component. The "chemical bond" used herein means a covalent bond, an ionic bond, a coordinate bond, a hydrogen bond or the like.

Preferable examples of the group represented by A are the same as exemplified as the functional groups of the thermoplastic resin used in the invention. On the other hand, the chemical structure of the group represented by B is preferably the same as or similar to the chemical structure of the thermoplastic resin that is the main component of the resin matrix, from the standpoint of compatibility. In the invention, the chemical structure of B as well as the thermoplastic resin preferably has an aromatic ring particularly from the standpoint of achieving high refractive index.

Examples of the surface treating agent preferably used in the invention include p-octylbenzoic acid, p-propylbenzoic acid, acetic acid, propionic acid, cyclopentanecarboxylic acid, dibenzyl phosphate, monobenzyl phosphate, diphenyl phosphate, di-α-naphthyl phosphate, phenylphosphoric acid, phenylphosphoric acid monophenyl ester, KAYAMER PM-21 (trade name; a product of Nippon Kayaku Co. , Ltd. ) , KAYAMER PM-2 (trade name, a product of Nippon Kayaku Co., Ltd.), benzenesulfonic acid, naphthalenesulfonic acid, paraoctylbenzenesulfonic acid, and silane coupling agents described in, for example, JP-A-5-221640, JP-A-9-100111 and JP-A-2002-187921. However, the surface treating agent is not limited to those.

Those surface treating agents may be used alone or as mixtures of tow or more thereof.

Those surface treating agents are added in a total amount of preferably from 0.01 to 2 times, more preferably from 0.03 to 1 time, and particularly preferably from 0.05 to 0.5 time, in terms of mass, the mass of the fine particles. (Plasticizer)

Where the thermoplastic resin used in the invention has high glass transition temperature, molding of a composition may not always be easy. Therefore, a plasticizer may be used to decrease the molding temperature of the composition of the invention. The addition amount where the plasticizer is added is preferably from 1 to 50% by mass, more preferably from 2 to 30% by mass, and particularly preferably from 3 to 20% by mass, based on the mass of the sum of the organic-inorganic hybrid composition.

The plasticizer used in the invention is required to determine totally considering compatibility with a resin, weather resistance, plasticizing effect and the like. The optimum material cannot be completely determined because of depending on other composition. However, from the standpoint of refractive index, a material having an aromatic ring is preferable, and a material having a structure represented by the following formula (4) can be exemplified as the representative example. Formula (4)

wherein B¹ and B² represent an alkyl group having from 6 to 18 carbon atoms or an allylalkyl group having from 6 to 18 carbon atoms, m is 0 or 1, X is one of

and R¹¹ and R¹² each independently represent a hydrogen atom or an alkyl group having 4 or less carbon atoms. In the compound represented by the formula (4), B¹ and B² can select an optional alkyl group or allylalkyl group in a carbon atom range of from 6 to 18. Where the number of carbon atoms is less than 6, there is the case that the molecular weight is too low, so that such a compound boils at the melting temperature of a polymer, resulting in generation of bubbles. On the other hand, where the number of carbon atoms exceeds 18, there is the case that compatibility with a polymer deteriorates, resulting in insufficient addition effect.

Examples of B¹ and B² specifically include linear alkyl groups such as n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tetradecyl group, n-hexadecyl group and n-octadecyl group; branched alkyl groups such as 2-hexyldecyl group and methyl-branched octadecyl group; and allylalkyl groups such as benzyl group and 2-phenylethyl group. Specific examples of the compound represented by the above formula (4) include the following compounds, and above all, W-I (trade name: KP-L155, a product of Kao Corporation) is preferable.

(Other Additives)

Other than the above components, the conventional release agents such as a modified silicone oil may be added for the purpose of improving moldability, and the conventional deterioration preventives such as hindered phenol type, amine type, phosphor type and thioether type may appropriately be added for the purpose of improving light resistance and thermal deterioration. Where those are added, the amount thereof is preferably from about 0.1 to 5% by mass based on the mass of the total solid content of the organic-inorganic hybrid composition.

[Production Method of Organic-Inorganic Hybrid Composition] The organic-inorganic hybrid composition of the invention can be produced by mixing components such as a thermoplastic resin and inorganic fine particles. The inorganic fine particles used in the invention have small particle size and high surface energy. Therefore, where those are isolated as a solid, it is difficult to redisperse the same. Therefore, the inorganic fine particles are preferably mixed with the thermoplastic resin in the state of being dispersed in a solution to form a stable dispersant. Preferable production method of the composite includes (1) a method of producing a composite of inorganic fine particles and a thermoplastic resin, comprising subjecting the inorganic fine particles to a surface treatment in the presence of the above-described surface treating agent, extracting the surface-treated inorganic fine particles in an organic solvent, and uniformly mixing the extracted inorganic fine particles and the thermoplastic resin, and (2) a method of producing a composite of inorganic fine particles and a thermoplastic resin, comprising uniformly mixing the inorganic fine particles and the thermoplastic resin using a solvent that can uniformly disperse or dissolve those. When the composite of inorganic fine particles and the thermoplastic resin is produced by the method (1) above, a water-insoluble solvent such as toluene, ethyl acetate, methyl isobutyl ketone, chloroform, dichloroethane, dichloromethane, chlorobenzene and methoxybenzene is used as an organic solvent. The -surface treating agent used in extraction of the inorganic fine particles in an organic solvent and the thermoplastic resin may be the same kind or different kind. The surface treating agent preferably used includes the materials described in the item of the surface treating agent above. In mixing the inorganic fine particles extracted in an organic solvent and the thermoplastic resin, additives such as plasticizers, release agents or different kind of polymers may be added, if required and necessary.

When the method (2) above is employed, a hydrophilic polar solvent such as dimethyl acetamide, dimethyl formamide, dimethyl sulfoxide, benzyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, l-methoxy-2-propanol, tert-butanol, acetic acid and propionic acid, alone or in a form of a mixed solvent thereof, or a mixed solvent of a water-insoluble solvent such as chloroform, dichloroethane, dichloromethane, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, chlorobenzene and methoxybenzene, and the above-described polar solvent is preferably used. In this case, separately from the above-described thermoplastic resin, a dispersant, a plasticizer, a release agent or a different kind of a polymer may be added, if required and necessary. When the inorganic fine particles dispersed in water/methanol, it is preferable that a hydrophilic solvent having a boiling point higher than that of water/alcohol and dissolving the thermoplastic resin is added, and water/methanol are then concentrated and distilled away, thereby substituting the dispersion of the inorganic file particles with a polar organic solvent, followed by mixing with a resin. In this case, the surface treating agent described above may be added.

Preferably, the solution of an organic-inorganic hybrid composition obtained according to the above-mentioned method (1) or (2) is, after the solvent is removed away therefrom according to a method of concentration, freeze-drying, spray-drying, reprecipitation from a suitable poor solvent or the like, powdered, then the resulting solid is melt-kneaded and shaped in a known method of injection molding, compression molding or the like. In this case, preferably, the powdery organic-inorganic hybrid composition of the invention is formed into a preform (precursor) having a predetermined weight and a predetermined shape according to a method of directly melting it under heat followed by extrusion or the like, and the resulting preform is deformed through compression molding into an optical article such as a lens or the like. In this case, for efficiently forming the product having a desired shape, the preform may be made to have a suitable curvature.

For the extrusion, an extruder may be used. In this, even though the energy supply per unit volume is less than 100 MJ/m³, inorganic fine particles may be sufficiently dispersed in the thermoplastic resin. The energy supply level is preferably from 1 to 50 MJ/m³, more preferably from 1 to 30 MJ/m³, even more preferably from 1 to 20 MJ/m³. The energy supply as referred to herein means the amount of energy per unit volume, as determined based on the energy parameter obtained by multiplying the kneading torque with the number of revolution followed by integrating the resulting product with the kneading time. In the conventional organic-inorganic hybrid composition, inorganic fine particles could not be sufficiently dispersed at an energy supply of less than 100 MJ/m³, and the composition could not realize high transparency. In organic-inorganic hybrid composition of the invention, inorganic fine particles can be sufficiently dispersed in the thermoplastic resin even at an energy supply of less than 100 MJ/m³, and the composition can realize high transparency. Concretely, when the composition is shaped into an article having a thickness of 1 mm, its light transmittance at 589 nm can be at least 70%.

In the invention, the apparatus for use in melt kneading may be a closed kneading apparatus or- a batch-type kneading apparatus, for example, a laboratory plastomill, a Blavender mixer, a Banbury mixer, a kneader, a roll, etc. Also usable is a continuous melt-kneading apparatus such as a single-screw extruder, a double-screw extruder, etc. Taken as a master batch, the organic-inorganic hybrid composition of the invention may be mixed with any other resin. [Optical Component]

By molding the organic-inorganic hybrid composition of the invention, the optical component of the invention can be produced. The optical component of the invention has the refractive index and the optical properties as described in the column about the organic-inorganic hybrid composition.

Among the optical components of the invention, those having a high refractive index with a thickness of 0.1 mm or more are particularly useful. Preferable are those having a thickness of 0.1 to 5 mm and particularly preferable are those having a thickness of 1 to 3 mm.

Molded articles of such thickness are generally produced, with much difficulty, by solution cast methods, because the solvent therein can hardly be drawn out. When the organic-inorganic hybrid composition of the invention is used, however, molding is readily done to readily prepare complicated shapes such as non-spherical shapes. As described above, in accordance with the invention, optical components with good transparency can be obtained, using the high refractive index properties of the fine particles.

The optical component using the organic-inorganic hybrid composition of the invention is not specifically limited so long as it utilizes the excellent optical properties of the organic-inorganic hybrid composition of the invention. The organic-inorganic hybrid composition can also be used to lens substrate and optical components that transmit light (so-called passive optical components) . Examples of an optically functional device provided with such an optical component include various display devices (liquid crystal display, plasma display and the like) , various projector devices (OHP, liquid crystal projector and the like) , optical fiber communication devices (optical waveguide, optical amplifier and the like) , and photographic devices such as cameras and video. Examples of the passive optical component used in an optically functional device include lenses, prisms, prism sheets, panels, films, optical waveguides, optical discs, and encapsulants of LED.

The optical component using the organic-inorganic hybrid composition of the invention is particularly suitable to a lens substrate. The lens substrate produced using the organic-inorganic hybrid composition of the invention has light transmission properties and lightweight properties in combination, and thus is excellent in optical properties. Further, it is possible to optionally adjust a refractive index of a lens substrate by appropriately adjusting the kind of monomers constituting the organic-inorganic hybrid composition and the amount of the inorganic fine particles dispersed.

The "lens substrate" used herein means a simple member that can exhibit lens function. A film or a member can be provided on the surface of or around the lens substrate according to use environment or the purpose of use of the lens. For example, a protective layer, an antireflective film, a hard coat layer or the like can be formed on the surface of the lens substrate. Further, the circumference of the lens substrate can be fitted in a substrate-holding frame or the like to fix. However, those films and frames are a member to be added to the lens substrate intended in the invention, and are distinguished from the lens substrate itself intended in the invention.

When the lens substrate of the invention is utilized as a lens, the lens substrate itself of the invention may be used as a lens, or a film or a frame is added to the lens substrate, and the assembly may be used as a lens. Kind and shape of a lens using the lens substrate of the invention is not particularly limited. The lens substrate of the invention is used in, for example, eyeglasses, lenses for optical instruments, lenses for optoelectronics, lenses for lasers, lenses for pickups, taking lenses (including various kinds of known taking lenses such as lenses for in-vehicle cameras, lenses for portable cameras, lenses for digital cameras, zoom lenses, progressive/regressive power lenses), lenses for OHP and microlens arrays.

EXAMPLES

The characteristics of the invention are described more specifically by referring to the following Examples. In the following Examples, the material used, its amount and ratio, the details of the treatment and the treatment process may be suitably modified or changed not overstepping the spirit and the scope of the invention. Accordingly, the invention should not be limited to the Examples mentioned below. [Method for Analysis and Evaluation]

In the Examples, each measurement and evaluation were conducted by the following methods:

(1) X-ray diffraction (XRD) spectrum measurement:

Using RINT 1500, a product of Rigaku Corporation (X-ray source: copper Ka ray, wavelength: 1.5418 angstroms), a sample was measured at 23⁰C.

(2) Observation with transmission electron microscope (TEM) :

Using a transmission electron microscope H-9000 UHR Model, a product of Hitachi, Ltd. (accelerating voltage : 20OkV, degree of vacuum in observation: about 7.6 x 10^~9 Pa), a sample was observed.

(3) Measurement of light transmittance :

A sample to be measured is molded to prepare a substrate having a thickness of 1.0 mm, and the substrate was measured with light having a wavelength of -589 nm using a UV-visible ray spectrometric device, UV-3100 (a product of Shimadzu

Corporation) .

(4) Measurement of refractive index:

Using an Abbe' s refractometer (DR-M4, a product of Atago) , a sample was measured with light having a wavelength of 589 nm.

(5) Measurement of molecular weight

Molecular weight here is a molecular weight in terms of polystyrene conversion by detection with a differential refractometer (solvent: tetrahydrofuran) using GPC analyzer using columns of TSK gel GMHxL, TSK gel G4000HxL and TSK gel

G2000HxL, trade names, products of Tosoh Corporation.

(6) Measurement of Glass Transition Temperature (Tg):

Using a differential scanning calorimeter (DSC6200, by Seiko Instruments) , Tg of each sample was measured in nitrogen under a heating condition of 10°C/min. Tg as defined in this description is one measured according to the method. (7) Impact Resistance Test:

A disc sample having an outer diameter of 8 mm and a thickness of 1 mm was prepared, this was fitted to the spot facing of an aluminium tool having a weight of 500 g with a washer, and from a height of 3 m, this was dropped five times onto concrete. 10 samples were tested in the same test, and in accordance with number of the cracked or damaged samples, the composition tested was evaluated as follows:

Good (O): The number of cracked or damaged samples was 0.

Average (Δ) : The number of cracked or damaged samples was 1 to 3.

Bad (x) : The number of cracked or damaged samples was 4 or more. [Preparation of Inorganic Fine Particle Dispersion]

(1) Preparation of aqueous zirconium oxide dispersion:

A zirconium oxychloride solution having a concentration of 50 g/L was neutralized with an aqueous 48% sodium hydroxide solution to prepare a zirconium hydrate suspension. The suspension was filtered, and washed with ion-exchanged water to give a zirconium hydrate cake. The cake was controlled to have a zirconium oxide concentration of 15% by mass, using ion-exchanged water as a solvent, then put into an autoclave, in which this was processed for hydrothermal treatment at 150⁰C for 24 hours under a pressure of 150 atmospheres to give a suspension of zirconium oxide fine particles. Through TEM, formation of zirconium oxide fine particles having a number-average particle size of 5 nm was confirmed.

(2) Preparation of zirconium oxide/dimethylacetamide dispersion (1) :

N, N ' -dimethylacetamide (50Og) was added to the zirconium oxide dispersion (aqueous 15 mas. % dispersion) (50Og) prepared in the above (1), then concentrated under reduced pressure to be at most about 500 g, and processed for solvent substitution, and then N, N' -dimethylacetamide was added thereto for concentration control to give a 15 mas . % zirconium oxide/dimethylacetamide dispersion (2) . [Production of Thermoplastic Resin] (1) Production of thermoplastic resin (P-I, 2, 4, 5, 6, 10, 12, 23, 24, 26, 29, 30) :

Placcel FMlA (trade name by Daicel Chemical Industry) (1 g) , styrene (99 g) and a polymerization initiator V-601 (trade name by Wako Pure Chemical Industries) (0.50 g) were dissolved in ethyl acetate (233.3 g), polymerized in a nitrogen atmosphere at 75°C for 3 hours, and poured into methanol (2 L) for reprecipitation to produce a thermoplastic resin (P-I) .

The molecular weight of the obtained resin was measured. Its number-average molecular weight was 55000, and its molecular weight distribution was 1.85.

The refractive index of the resin was measured with an Abbe's refractiometer, and was 1.59 at a wavelength of 589 nm. Other resins (P-2, P-4, P-6, P-10, P-12, P-23, P-24, P-26, P-29, P-30) used in the following Examples were produced in the - same manner, for which, .however, the type of the monomer, the monomer concentration and the initiator concentration were changed. (2) Production of Thermoplastic Resin (P-37) :

In accordance with the method of Example 2 in JP-A 2004-217647, sodium 2, 2-bis (4-hydroxyphenyl) pentanesulfonate was produced. In accordance with the production example of

Example 3 in JP-A 5-222175, a thermoplastic resin P-37 was produced, for which, however, a part of bisphenol A diacetate was replaced with sodium 2, 2-bis (4-hydroxyphenyl) pentanesulfonate.

The molecular weight of the obtained resin was measured by GPC, and its number-average molecular weight was 50000. The refractive index of the resin was measured with an Abbe's refractiometer, and was 1.61 at a wavelength of 589 nm. (3) Production of Comparative Resin (X-I, 2) (compound B-13 in JP-A 2007-238929) :

Thermoplastic resins X-I and X-2 were produced in the same manner as that for the above-mentioned thermoplastic resin

(P-D • Comparative Resin (X-I) :

X-I

a/b = 99/1 (by mass )

Mn = 20000 Comparative Resin (X-2 ) :

a/b = 94/6 (by mass) Mn = 20000

(4) Production of Comparative Resin (X-3) (compound No. (1) in JP-A 2006-131736) :

Methyl methacrylate (100 g) and a polymerization initiator V-601 (trade name by Wako Pure Chemical Industries) (0.5 g) were added to ethyl acetate (233.3 g) , and polymerized in a nitrogen atmosphere at 75°C for 3 hours, and the reaction liquid was put into methanol (2 L) for reprecipitation to give a comparative resin X-3 not having a particle-bonding functional group in the side branch thereof. As measured through GPC, the number-average molecular weight of the resin was 55000. As measured with an Abbe's refractiometer, the refractive index of the resin was 1.49. Comparative Resin (X-3) :

(5) Production of Comparative Resin (X-4) :

Styrene (100 g) and a polymerization initiator V-601 (trade name by Wako Pure Chemical Industries) (0.5 g) were added to ethyl acetate (233.3 g) , and polymerized in a nitrogen atmosphere at 75°C for 3 hours, and the reaction liquid was put into methanol (2 L) for reprecipitation to give a comparative resin X-4 not having a particle-bonding functional group in the side branch thereof. As measured through GPC, the number-average molecular weight of the resin was 58000. As measured with an Abbe's refractiometer, the refractive index of the resin not having a functional group was 1.59. Comparative Resin (X-4) :

[Preparation of Material Composition and Production of

Transparent Shaped Body] [Example 1]

To the above-mentioned zirconium oxide/dimethylacetamide dispersion, added were the thermoplastic resin P-I, 4-n-propylbenzoic acid (C3BA) , and a plasticizer tetraphenyl ether S-3103 (trade name by Matsumura Petrochemical Laboratories) in a ratio by mass of ZrO₂ solid content/P-1/n-propylbenzoic acid/tetraphenyl ether = 41.7/45.8/8.3/4.2, and uniformly stirred and mixed, and then the dimethylacetamide solvent was concentrated under heat under reduced pressure. The concentrated residue was dried through a vacuum pump at 90⁰C for 2 hours to give an organic-inorganic hybrid composition NC-I.

Next, the organic/inorganic nanocomposite powder NC-I was put into a compound tester, Technovel ' s ULT-nano (trade name, jetting orifice diameter 3 mm) , and as set at a barrel temperature of 170°C and a dies temperature of 180⁰C, this was melt-extruded to give a transparent rod-shaped organic-inorganic hybrid composition. The extrusion pressure was 6.1 MPa, and the energy supply per unit volume was 6.1 MJ/m³. Further, the rod-shaped organic-inorganic hybrid composition was cut into pieces having a thickness of 1 mm, and the light transmittance and the refractive index thereof were measured. In addition, the dispersion condition of the particles was observed through cross-section TEM, and it was confirmed that the fine particles were uniformly dispersed in the resin. Further, the rod-shaped organic-inorganic hybrid composition was cut into preforms having a thickness of about 3.5 mm, which were worked through thermal compression molding

(temperature; 180⁰C, pressure: 13.7 MPa, time: 2 minutes) to produce tabular transparent shaped articles having a thickness of 1 mm and a diameter φ of 3 mm. The samples were tested according to the above-mentioned impact resistance test.

The constitutive ingredients of the organic-inorganic hybrid composition NC-I are shown in Table 1; and the test results are in Table 2 below. [Examples 2 to 13]

In the same manner as in the above Example 1, organic-inorganic hybrid compositions NC-2 to 13 each having the constitutive ingredients as in Table 1 were produced. Extruded through an extruder, these organic-inorganic hybrid compositions were all transparent. As observed through cross-section TEM, the dispersion condition of the particles was such that the fine particles were uniformly dispersed in the resin.

The organic-inorganic hybrid compositions were tested and evaluated, and their results are shown in Table 2. [Example 14]

According to the method of Production Example 9 in JP-A 2003-73559, titanium oxide fine particles were produced. Through X-ray diffractiometry (XRD) and observation with a transmitting electronic microscope (TEM) , the formation of anatase-type titanium oxide fine particles (having a number-average particle size of about 5 ran) was confirmed. The titanium oxide fine particles were suspended in 1-butanol, then ultrasonically processed for 30 minutes, and heated at 100⁰C for 3 hours. The obtained milky suspension was dropwise added to a chloroform solution of 10 mas . % polymer dispersion P-I with stirring at room temperature, taking 5 minutes, in such a manner that the titanium oxide solid content could be 40% by mass of the overall solid content of the resulting dispersion. The solvent was evaporated away from the obtained mixture, and the thus-obtained organic-inorganic hybrid composition NC-14 was rod-wise extruded, worked and evaluated in the same manner as in Example 1. Extruded through an extruder, the organic-inorganic hybrid composition NC-14 was transparent. As observed through cross-section TEM, the dispersion condition of the particles was such that the fine particles were uniformly dispersed in the resin.

The constitutive ingredients of the organic-inorganic hybrid composition NC-14 are shown in Table 1, and the test results thereof are in Table 2 below. [Examples 15, 16]

Organic-inorganic hybrid compositions NC-15 and NC-16 were produced in the same manner as in Example 14, for which, however, P-I in Example 14 was replaced with P-23 and P-24, respectively. The constitutive ingredients are shown in Table 1. Extruded through an extruder, the organic-inorganic hybrid compositions were both transparent. As observed through cross-section TEM, the dispersion condition of the particles was such that the fine particles were uniformly dispersed in the resin. The test results of the organic-inorganic hybrid compositions NC-15 and NC-16 are shown in Table 2. [Comparative Examples 1 to 5] Comparative organic-inorganic hybrid compositions NCX-I to NCX-5 comprising the constitutive ingredients as in Table 1 were produced in the same manner as in Example 1, for which, however, the thermoplastic resin P-I in Example 1 was replaced with comparative resins X-I to X-4. Extruding through an extruder of the composition was tried in the same manner as in Example 1, but the compositions NCX-I to NCX-3 could not be extruded at an energy supply of 20 MJ/m³ since their flowability was poor . Then, the energy supply was increased up to 100 MJ/m³, but the extruded products were colored in brown and were nontransparent . On the other hand, when extruded at an energy supply of 100 MJ/m³, the compositions NCX-4 and NCX-5 produced nontransparent products. The dispersion condition of the particles in these extruded products was observed through cross-section TEM, and aggregation of fine particles was confirmed.

The test results of the organic-inorganic hybrid compositions NCX-I to NCX-5 are shown in Table 2 below.

Table 1

(Note) C3BA is 4-π-propylbenzoic acid; S-3103 is tetraphenyl ether S-3103 (trade name by Matsumura Petrochemical Laboratories).

Table 2

From Table 1, it is seen that the organic-inorganic hybrid compositions of the invention have good flowability and particle dispersibility and therefore can be shaped into good and transparent shaped articles at a low energy supply level.

The organic-inorganic hybrid compositions in which the thermoplastic resin has a carboxyl group directly bonding to the side branch thereof (Comparative Resin X-I, 2) could not be extruded out through an extruder at a low energy supply, and could be extruded out only at an energy supply level of 100 MJ/m³ or so. However, even through extrude out at such a high energy supply level, the shaped articles could not be transparent

(Comparative Examples 1 to 3) . Even NCX-2 in which the amount of the plasticizer was increased (Comparative Example 2) could not be significantly improved in point of the flowability thereof. On the other hand, the organic-inorganic hybrid composition of the invention comprising a thermoplastic resin that has a carboxyl group bonding to the main chain thereof via a linking chain of 4 atoms (e.g., P-12; Example 9) can form a transparent product at a energy supply level of less than 100 MJ/m³, though the resin has a molecular weight of more than 50,000 on a level that satisfies good impact resistance. Further, in the organic-inorganic hybrid composition comprising a thermoplastic resin that has a carboxyl group bonding to the main chain thereof via a linking chain of 5 atoms or more (e.g., P-10), the flowability of the resin was remarkably increased, and the composition can form a product more excellent in transparency at a low energy supply level, ^■ though the resin is a high-molecular polymer having a number-average molecular weight of more than 50,000 (e.g., Example 3) .

In the organic-inorganic hybrid composition of the invention, when the molecular weight of the resin is lowered, then the flowability of the resin composition is increased, but the brittleness of the shaped product of the composition tends to increase. Therefore, the number-average molecular weight of the resin constituting the composition is preferably at least 50,000 (for example, in comparison between Examples 1 and 2) . From the viewpoint of the heat resistance of the composition, the resin preferably has Tg of not lower than 8O⁰C. In general, the flowability of a resin lowers when the molecular weight and Tg thereof are increased. However, it is understood that the organic-inorganic hybrid composition of the invention can have good flowability and can give shaped articles excellent in transparency though the resin therein is a high-molecular polymer having Tg of not lower than 80⁰C and having a number-average molecular weight of not lower than 50,000. The organic-inorganic hybrid compositions comprising the comparative resin (X-3, 4) not having a functional group in the side branch thereof could hardly give transparent shaped articles at an energy supply level of not more than 100 MJ/m³ (Comparative Examples 4, 5) ; however, as opposed to these, the composition of the invention in which the resin has a functional group can give shaped articles excellent in transparency. The number of the functional groups per one polymer chain is more preferably at most 20, since the composition can keep high transparency under extrusion pressure (Examples 1 to 6, 8 to 16) .

On the other hand, under the compression molding condition shown in Example 1, when a convex/concave mold is used, the organic-inorganic hybrid compositions of the invention (NC-1-15) can give concave/convex lenses having the mold profile correctly transferred thereto.

As described in the above, the organic-inorganic hybrid composition of the invention has excellent flowability and can be readily worked into transparent shaped articles with good producibility by a small energy supply. The organic-inorganic hybrid composition is therefore favorable for producing high-quality optical components, taking advantage of the excellent properties of the organic material constituting it.

Claims

1. An organic-inorganic hybrid composition comprising inorganic fine particles and a thermoplastic resin, wherein the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 4 or more atoms.

2. The organic-inorganic hybrid composition according to claim 1, wherein the thermoplastic resin has a structure in which a functional group capable of forming a chemical bond with the inorganic fine particles bonds to a main chain of the resin via a linking chain having a chain length of 5 or more atoms .

3. The organic-inorganic hybrid composition according to claim 2, wherein the functional group is selected from the group consisting of

4. The organic-inorganic hybrid composition according to any one of claims 1 to 3, wherein the thermoplastic resin has a structural unit represented by the following formula ( D : Formula

W

\ \ .

wherein R represents a hydrogen atom, a halogen atom or a methyl group; W represents a linking group having a chain length of 4 or more atoms consisting of one or more groups selected from the group consisting of -0-, -CO-, -NH-, -S-, -CS-, substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups; and Z represents a functional group capable of bonding to the inorganic fine particles.

5. The organic-inorganic hybrid composition according to any one of claims 1 to 3, wherein the thermoplastic resin has a structural unit represented by the following formula (2 ) : ^{■ ■ •}

Formula (2)

6. The organic-inorganic hybrid composition according to any one of claims 1 to 5, wherein the functional group is contained in a range of from 0.1 to 20 on the average per one polymer chain of the thermoplastic resin.

7. The organic-inorganic hybrid composition according to any one of claims 1 to 6, wherein the thermoplastic resin has a weight average molecular weight of 50,000 or more.

8. The organic-inorganic hybrid composition according to any one of claims 1 to 7, wherein the inorganic fine particles have a number average particle size of from 1 to 20 nm.

9. The organic-inorganic hybrid composition according to any one of claims 1 to 8, wherein the inorganic fine particles contain zirconium oxide, tin oxide, zinc oxide or titanium oxide.

10. The organic-inorganic hybrid composition according to any one of claims 1 to 9, wherein the composition of 1 mm thick has a light transmittance of 70% or more at a wavelength of 589 nm.

11. The organic-inorganic hybrid composition according to any one of claims 1 to 10, wherein the composition has a refractive index of 1.60 or more.

12. A transparent molding comprising the organic-inorganic hybrid composition of any one of claims 1 to 11.

13. An optical component comprising the organic-inorganic hybrid composition of any one of claims 1 to 11.

14. A lens comprising the organic-inorganic hybrid composition of any one of claims 1 to 11.