WO2009017179A1

WO2009017179A1 - Organic-inorganic hybrid composition and optical component

Info

Publication number: WO2009017179A1
Application number: PCT/JP2008/063712
Authority: WO
Inventors: Ryo Suzuki; Tatsuhiko Obayashi; Hiroaki Mochizuki; Osamu Sawanobori
Original assignee: Fujifilm Corporation
Priority date: 2007-07-27
Filing date: 2008-07-24
Publication date: 2009-02-05
Also published as: JP5345302B2; TW200911902A; JP2009029941A

Abstract

An organic-inorganic hybrid composition comprising a block copolymer constituted of a hydrophobic segment and a hydrophilic segment and an inorganic fine particle having a number average particle size of from 1 nm to 15 nm, the organic-inorganic hybrid composition having a refractive index of 1.60 or more at a wavelength of 589 nm.

Description

DESCRIPTION

ORGANIC-INORGANIC HYBRID COMPOSITION AND OPTICAL COMPONENT

TECHNICAL FIELD

The present invention relates to an organic-inorganic hybrid composition which is excellent in high refraction properties, transparency, lightweight properties and processability and to an optical component configured to contain the same, inclusive of lens base materials (for example, spectacle lenses, optical instrument lenses, optoelectronic lenses, laser lenses, pickup lenses, vehicle-mounted camera lenses, mobile phone camera lenses, digital camera lenses, OHP lens) .

BACKGROUND ART

In recent years, the study of optical materials is eagerly carried out, and in particular, in the field of a lens material, the development of a material which is excellent in high refraction properties, low dispersibility (namely, a high Abbe's number), heat resistance, transparency, easy moldability, lightweight properties, chemical resistance, solvent resistance and the like is strongly desired.

A plastic lens is light and hardly cracked as compared with inorganic materials such as glass and can be processed into a variety of shapes. Therefore, in recent years, the plastic lens is rapidly spreading in not only spectacle lenses but optical materials such as mobile phone camera lenses and pickup lenses. Following this, in order to make the lens thin, a raw material itself has been demanded to realize a high refractive index. For example, there have been actively studied a technology for introducing a sulfur atom into a polymer (see, for example, JP-A-2002-131502 and JP-A-10-298287) ; and a technology for introducing a halogen atom or an aromatic ring into a polymer (see, for example, JP-A-2004-244444) . However, a plastic material having a large refractive index and good transparency and capable of being a replacement for glass has not been developed yet. Also, in optical fibers or optical waveguides, materials having a different refractive index are used jointly, or a material having distribution in a refractive index is used. In order to cope with these matters, the development of a technology capable of arbitrarily adjusting the refractive index is also desired.

Since it is difficult to increase the refractive index by only an organic material, there is reported a method for preparing a high-refractive index material by dispersing an inorganic material having a high refractive index in a resin matrix (see, for example, JP-A-2003-73559) . Also, in order to reduce the attenuation of transmitted light by the Rayleigh scattering, it is preferable to uniformly disperse an inorganic fine particle having a particle size of not more than 15 nm in a resin matrix. However, since a primary particle having a particle size of not more than 15 nm very easily agglomerates, it is extremely difficult to uniformly disperse it in the resin matrix. Also, when the attenuation of transmitted light in an optical path length corresponding to the thickness of a lens is taken into consideration, the addition amount of the inorganic fine particle must be controlled. For that reason, so far, it has not been able to disperse a fine particle in a high concentration in a resin matrix without lowering the transparency of a resin.

Also, there have been reported a resin composition molding which is a molding composed mainly of a thermoplastic resin composition having an ultra-fine particle with a number average particle size of from 0.5 to 50 nm dispersed therein and has a birefringence of not more than 10 nm in average per 1 mm of an optical path length (see, for example, JP-A-2003-147090) ; and a thermoplastic material composition composed of a thermoplastic resin having refractive index and Abbe's number expressed by specified numerical expressions and an inorganic fine particle having specified average particle diameter and refractive index and an optical component using the same (see, for example, JP-A-2003-73563 and JP-A-2003-73564) . These materials are a material having an inorganic fine particle dispersed in a resin. However, all of them did not exhibit sufficient performance from the viewpoint of dispersing the fine particle in a high concentration in the resin matrix without lowering the transparency of the resin.

On the other hand, as to an organic-inorganic hybrid composition, for example, there is reported a method for melt kneading an inorganic particle whose surface is modified with an organic material and an acid group-containing resin; however, the addition amount of the inorganic particle is about 1% by mass and cannot be said to be sufficient (see, for example, JP-A-2004-217714) . Also, there is reported an organic-inorganic hybrid composition in which a surface-modifying group of an inorganic particle and a resin are bonded via a linker (see, for example, JP-A-2004-352975 and JP-T-2004-524396) . However, the operation is complicated such that the formation of a bond requires a high temperature, and there is a possibility of the occurrence of gelation. Therefore, sufficient performance could not be exhibited from the viewpoint of molding processability. Also, any of these patent documents does not describe a thick transparent article which can be used in a lens with a high refractive index.

DISCLOSURE OF THE INVENTION

Material compositions having high refraction properties, heat resistance, transparency and lightweight properties and capable of arbitrarily controlling a refractive index and optical components configured to contain the same have not been found yet, and the development thereof has been desired.

Under these circumstances, the invention has been made. An object of the invention is to provide an organic-inorganic hybrid composition having a fine particle uniformly dispersed in a resin matrix, having excellent transparency and high refractive index and an optical component using the same, for example, lens base materials.

In order to achieve the foregoing object, the present inventors made extensive and intensive investigations. As a result, it has been found that an organic-inorganic hybrid composition containing, as raw materials, a specified high-refractive index resin having excellent transparency and an inorganic fine particle having a specified refractive index has high refraction properties and excellent transparency due to a uniform dispersion effect of the fine particle, leading to .accomplishment of the invention as described below.

[1] An organic-inorganic hybrid composition comprising a block copolymer constituted of a hydrophobic segment and a hydrophilic segment and an inorganic fine particle having a number average particle size of from 1 nm to 15 nm, the organic-inorganic hybrid composition having a refractive index of 1.60 or more at a wavelength of 589 nm.

[2] The organic-inorganic hybrid composition as set forth in [1] , wherein the block copolymer has a functional group capable of forming an arbitrary chemical bond with the inorganic fine particle.

[3] The organic-inorganic hybrid composition as set forth in [1] or [2] , wherein the block copolymer is a thermoplastic resin having a functional group selected among the following groups :

(wherein R¹¹, , R¹³ and R¹⁴ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted aryl group) , -SO₃H, -OSO₃H, -CO₂H and -Si (OR¹⁵) _miR¹⁶ ₃-m1 (wherein R¹⁵ and R¹⁶ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted aryl group; and ml represents an integer of from 1 to 3) . [4] The organic-inorganic hybrid composition as set forth in any one of [1] to [3] , wherein the content of the functional group is from 0.05 to 5.0 mmoles/g relative to the whole of the block copolymer. [5] The organic-inorganic hybrid composition as set forth in any one of [1] to [4], wherein the inorganic fine particle is a metal oxide fine particle having a refractive index of from 1.90 to 3.00.

[6] The organic-inorganic hybrid composition as set forth in any one of [1] to [5] , wherein the inorganic fine particle is a fine particle containing zirconium oxide, zinc oxide or titanium oxide.

[7] The organic-inorganic hybrid composition as set forth in any one of [1] to [6] , wherein the inorganic fine particle is contained in an amount of 20% by mass or more. [8] The organic-inorganic hybrid composition as set forth in any one of [1] to [7], which is thermoplastic. [9] An article obtained by forming the organic-inorganic hybrid composition as set forth in any one of [1] to [8]. [10] The article as set forth in [9], having a light transmittance as reduced in a thickness of 1 mm of 70% or more at a wavelength of 589 nm.

[11] The article as set forth in [9] or [10], having a maximum thickness of 0.1 mm or more. [12] An optical component comprising the article as set forth in any one of [9] to [11] .

[13] The optical component as set forth in [12], which is a lens base material.

According to the invention, it is possible to provide an organic-inorganic hybrid composition having excellent transparency and high refractive index and an optical component using the same. Also, according to the invention, it is easy to provide an optical component having good mechanical strength and heat resistance.

MODES FOR CARRYING OUT THE INVENTION

The organic-inorganic hybrid composition of the invention and the optical component configured to contain the same are hereunder described in detail. The following description of the constitutional requirements is made on the basis of representative embodiments of the invention, but it should not be construed that the invention is limited to those embodiments. In this specification, numerical value ranges expressed by the term "to" mean that the numerical values described before and after it are included as a lower limit and an upper limit, respectively.

[Organic-inorganic hybrid composition]

The organic-inorganic hybrid composition of the invention (hereinafter sometimes simply referred to as "material composition of the invention") is an organic-inorganic hybrid composition containing a block copolymer constituted of a hydrophobic segment and a hydrophilic segment and an inorganic fine particle having a number average particle size of from 1 nm to 15 nm, the organic-inorganic hybrid composition having a refractive index of 1.60 or more at a wavelength of 589 nm. That is, the organic-inorganic hybrid composition of the invention is a composition in which an inorganic fine particle is dispersed in the block copolymer in the invention.

The material composition of the invention contains the foregoing block copolymer and inorganic fine particle as essential constitutional components. Besides, the material composition of the invention may contain additives such as a resin of other type, a dispersant, a plasticizer and a releasing agent as the need arises.

In the material composition of the invention, its refractive index is 1.60 or more, more preferably 1.63 or more, and especially preferably 1.65 or more at a wavelength of 589 nm. The material composition of the invention can be controlled to have a desired refractive index by properly adjusting the type and use amount of the resin or inorganic fine particle to be used. The range of the refractive index to be controlled is not particularly limited so far as it is 1.60 or more. For example, the refractive index can be controlled within, for example, the range of 1.60 or more and less than 1.67, the range of 1.63 or more and less than 1.67, the range of 1.65 or more and less than 1.67. In the material composition of the invention, its light transmittance as reduced in a thickness of 1 mm at a wavelength of 589 nm is preferably 70% or more, more preferably 75% or more, and especially preferably 80% or more. Also, the light transmittance at a wavelength of 405 nm is preferably 60% or more, more preferably 65% or more, and especially preferably 70% or more. When the light transmittance as reduced in a thickness of 1 mm at a wavelength of 589 nm is 70% or more, it is easy to obtain a lens base material having more preferable properties. In the invention, the light transmittance as reduced in a thickness of 1 mm is a value obtained by forming the material composition to prepare a substrate having a thickness of 1.0 mm and measuring it by a spectrophotometer for ultraviolet and visible region (UV-3100, manufactured by Shimadzu Corporation) . For the purpose of preventing the deposition of dusts to the obtained article, it is desirable that the material composition of the invention is hardly electrified. Its dielectric strength is preferably from -2 to 15 kV, more preferably from -1.5 to 7.5 kV, and especially preferably from -1.0 to 7.0 kV.

In the material composition of the invention, its glass transition temperature is preferably from 100°C to 400°C, and more preferably from 130°C to 38O⁰C. When the glass transition temperature is 100⁰C or higher, sufficient heat resistance is easily obtained; and when the glass transition temperature is not higher than 400°C, there is a tendency that it is easy to achieve molding processing.

In the material composition of the invention, it is preferable that when kept at 200⁰C for 2 hours, its volatile component content is not more than 2% by mass; it is more preferable that when kept at 230°C for 2 hours, its volatile component content is not more than 2% by mass; and it is especially preferable that when kept at 25O⁰C for 2 hours, its volatile component content is not more than 2% by mass.

In the material composition of the invention, its percentage of saturated water absorption is preferably not more than 2% by mass, more preferably not more than 1% by mass, and especially preferably not more than 0.5% by mass.

[Inorganic fine particle]

The inorganic fine particle to be used in the invention is not particularly limited, and fine particles described in, for example, JP-A-2002-241612, JP-A-2005-298717 and JP-A-2006-70069 can be used.

Specifically, oxide fine particles (for example, aluminum oxide, titanium oxide, niobium oxide, zirconium oxide, zinc oxide, magnesium oxide, tellurium oxide, yttrium oxide, indium oxide, tin oxide) , composite oxide fine particles (for example, lithium niobate, potassium niobate, lithium tantalate) , sulfide fine oxides (for example, zinc sulfide, cadmium sulfide) , other semi-conductor crystal fine particles (for example, zinc selenide, cadmium selenide, zinc telluride, cadmium telluride) , LiAlSiO₄, PbTiO₃, Sc₂W₃Oi₂, ZrW₂O₈, AlPO₄, Nb₂O₅, LiNO₃ and the like can be used.

In particular, of these, metal oxide fine particles are preferable. Above all, any one member selected from the group consisting of zirconium oxide, zinc oxide, tin oxide and titanium oxide is preferable; and any one member selected from the group consisting of zirconium oxide, zinc oxide and titanium oxide is more preferable. Furthermore, it is especially preferable to use a zirconium oxide fine particle having good transparency in a visible region and low photocatalytic activity.

The inorganic fine particle to be used in the invention may be a hybrid material composed of plural components from the viewpoints of refractive index, transparency, stability and the like. Also, for a variety of purposes of reducing photocatalytic activity, reducing a percentage of water absorption and the like, the inorganic fine particle may be doped with a dissimilar element, or the surface layer of the inorganic fine particle may be coated with a dissimilar metal oxide (for example, silica, alumina) or may be subjected to surface modification with a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, an organic acid (for example, carboxylic acids, sulfonic acids, phosphoric acids, phosphonic acids) or the like. Furthermore, a combination of two or more types thereof can be employed depending upon the purpose.

In the inorganic fine particle to be used in the invention, its refractive index is not particularly limited. In the case where the material composition of the invention is used for an optical component to be required to have a high refractive index, it is preferable that the inorganic fine particle also has high refractive index properties in addition to the foregoing heat temperature dependency. In that case, the refractive index of the inorganic fine particle to be used is preferably from 1.9 to 3.0, more preferably 2.0 to 2.7, and especially preferably from 2.1 to 2.5 at 22⁰C and at a wavelength of 589 nm. When the refractive index of the fine particle is not more than 3.0, since a difference in refractive index from the resin is relatively small, there is a tendency that the Rayleigh scattering is easily inhibited. Also, when the refractive index is 1.9 or more, there is a tendency that an effect for realizing a high refractive index is easily obtained.

The refractive index of the inorganic fine particle can be, for example, estimated by a method of forming a hybrid material hybridized with the thermoplastic resin to be used in the invention into a transparent film, measuring its refractive index by an Abbe's refractometer (for example, "DM-M4", manufactured by Atago Co. , Ltd.) and calculating the refractive index of the inorganic fine particle from a refractive index of only the resin component as measured separately, a method of measuring refractive indexes of fine particle dispersions having a different concentration, thereby calculating the refractive index of the inorganic fine particle, or other method. When the number average particle size of the inorganic fine particle to be used in the invention is too small, there may be the case where the properties inherent to a substance constituting the fine particle vary, whereas when the number average particle size is too large, there may be the case where influences of the Rayleigh scattering become noticeable, thereby extremely lowering the transparency of the material composition. In consequence, a lower limit value of the number average particle size of the inorganic fine particle to be used in the invention is preferably 1 nm or more, more preferably 2 nm or more, and further preferably 3 nm or more; and an upper limit value thereof is preferably not more than 15 nm, more preferably not more than 10 nm, and further preferably not more than 7 nm. That is, the number average particle size of the inorganic fine particle in the invention is preferably from 1 nm to 15 nm, more preferably from 2 nm to 10 nm, and especially preferably from 3 nm to 7 nm.

Also, it is desirable that the inorganic fine particle to be used in the invention is satisfied with the foregoing average particle size and has narrow particle size distribution as far as possible . There are a variety of manners for defining such a monodispersed particle. For example, the numerical value specified range described in JP-A-2006-160992 is also applicable to the preferred particle size distribution range of the fine particle to be used in the invention.

Here, the foregoing number average particle size can be measured by an X-ray diffraction (XRD) analyzer or a transmission electron microscope (TEM) or the like.

The manufacturing method of the inorganic fine particle to be used in the invention is not particularly limited, and any known methods can be employed.

For example, the desired oxide fine particle can be obtained by using a metal halide or a metal alkoxide as a raw material and hydrolyzing it in a reaction system containing water. Details of this method are described in, for example,

Japanese Journal of Applied Physics, Vol. 37, pages 4603 to 4608

(1998) or Langmuir, Vol. 16, No. 1, pages 241 to 246 (2000) .

Also, as other methods than the method of hydrolysis in water, a method of preparing an inorganic fine particle in an organic solvent or in an organic solvent having the thermoplastic resin of the invention dissolved therein may be employed. On that occasion, a variety of surface treating agents (for example, silane coupling agents, aluminate coupling agents, titanate coupling agents, organic acids (for example, carboxylic acids, sulfonic acids, phosphonic acids) ) may be made coexistent.

Examples of the solvent to be used in these methods include acetone, 2-butanone, dichloromethane, chloroform, toluene, ethyl acetate, cyclohexanone and anisole. These solvents may be used singly or in admixture of plural kinds thereof.

Examples of the synthesis method of the inorganic fine particle include, in addition to the foregoing methods, a variety of general synthesis methods of a fine particle described in, for example, JP-A-2006-70069, including methods for preparing an inorganic fine particle in a vacuum process such as a molecular beam epitaxy method and a CVD method.

From the viewpoints of transparency and realization of a high refractive index, the content of the inorganic fine particle in the transparent article of the invention is preferably from 20 to 95% by mass, more preferably from 25 to

70% by mass, and especially preferably from 30 to 60% by mass.

Also, from the standpoint of dispersibility, a mass ratio of the inorganic fine particle 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 especially preferably from 1/0.05 to 1/5.

[Resin]

The resin to be used in the invention is a block copolymer constituted of a hydrophobic segment (A) and a hydrophilic segment (B) and is preferably thermoplastic.

The hydrophobic segment (A) as referred to herein refers to a segment having such properties that a polymer composed of only the segment (A) is insoluble in water or methanol; and the hydrophilic segment (B) as referred to herein refers to a segment having such properties that a polymer composed of only the segment (B) is soluble in water or methanol. Examples of a type of the block copolymer include an AB type, a B¹AB² type

(the two hydrophilic segments B¹ and B² may be the same or different) and an A¹BA² type (the two hydrophobic segments A¹ and A² may be the same or different) . Of these, in view of good dispersion properties , block copolymers of an AB type or an A¹BA² type are preferable; and in view of the manufacturing aptitude, block copolymers of an AB type or an ABA type (the two hydrophobic segments of the A¹BA² type are the same) are more preferable, with an AB type being especially preferable. The hydrophobic segment and the hydrophilic segment can be each selected among polymers which have hitherto been known, for example, vinyl polymers obtained through polymerization of a vinyl monomer, polyethers, ring-opening metathesis polymerization polymers and condensation polymers (for example, polycarbonates, polyesters, polyamides, polyetherketones, polyethersulfones) . Of these, vinyl polymers, ring-opening metathesis polymerization polymers, polycarbonates and polyesters are preferable; and vinyl polymers are more preferable in view of manufacturing aptitude. As the vinyl monomer (A) for forming the hydrophobic segment (A) , for example, the following can be exemplified.

That is, examples thereof include acrylic esters or methacrylic esters (in which the ester group thereof is a substituted or unsubstituted aliphatic ester group or a substituted or unsubstituted aromatic ester group, for example, a methyl group, a phenyl group, a naphthyl group) ; acrylamides and methacrylamides, specifically N-mono-substituted acrylamides, N-di-substituted acrylamides, N-mono-substituted methacrylamides and N-di-substituted methacrylamides (in which the substituent of the mono-substituted materials and the di-substituted materials is a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group, for example, a methyl group, a phenyl group, a naphthyl group) ; olefins, specifically dicyclopentadiene, norbornene derivatives, ethylene, propylene, 1-butene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, 2, 3-dimethylbutadiene, vinylcarbazole, etc.; styrenes, specifically styrene, methylstyrene, diemthylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, tribromostyrene, methyl vinylbenzoate, etc.; vinyl ethers, specifically methyl vinyl ether, butyl vinyl ether, phenyl vinyl ether, methoxyethyl vinyl ether, etc. ; and other monomers, for example, butyl crotonate, hexyl crotonate, dimethyl itaconate, dibutyl itaconate, diethyl maleate, dimethyl maleate, dibutyl maleate, diethyl fumarate, dimethyl fumarate, dibutyl fumarate, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, N-vinyloxazolidone, N-vinylpyrrolidone, vinylidene chloride, methylene malonitrile, vinylidene, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, dioctyl-2-methcryloyloxyethyl phosphate .

Of these, acrylic esters and methacrylic esters in which the ester group thereof is an unsubstituted aliphatic group or a substituted or unsubstituted aromatic group; N-mono-substituted acrylamides, N-di-substituted acrylamides, N-mono-substituted methacrylamides and N-di-substituted methacrylamides in which the substituent thereof is an unsubstituted aliphatic group or a substituted or unsubstituted aromatic group; and styrenes are preferable. Acrylic esters and methacrylic esters in which the ester group thereof is a substituted or unsubstituted aromatic group; and styrenes are more preferable.

As the vinyl monomer (B) for forming the hydrophilic segment (B) , for example, the following can be exemplified. That is, examples thereof include acrylic acid, methacrylic acid and acrylic esters and methacrylic esters each having a hydrophilic substituent in an ester site thereof; styrenes having a hydrophilic substituent in an aromatic ring moiety thereof; and vinyl ethers, acrylamides, methacrylamides, N-mono-substituted acrylamides, N-di-substituted acrylamides, N-mono-substituted methacrylamides and N-di-substituted methacrylamides each having a hydrophilic substituent.

The block copolymer to be used in the invention has a functional group capable of forming an arbitrary chemical bond with the inorganic fine particle of the invention. Examples of the chemical bond as referred to herein include a covalent bond, an ionic bond, a coordination bond and a hydrogen bond. In the case where plural functional groups are present, these functional groups may be each one capable of forming a different chemical bond with the inorganic fine particle. Whether or not a chemical bond can be formed is judged by whether or not when the thermoplastic resin and the inorganic fine particle are mixed in an organic solvent, the functional group or groups of the thermoplastic resin can form a chemical bond with the inorganic fine particle. All of the functional groups of the thermoplastic resin may form a chemical bond with the inorganic fine particle, or a part of the functional groups of the thermoplastic resin may form a chemical bond with the inorganic fine particle.

The functional group capable of being bound with the inorganic fine particle has a function for stably dispersing the inorganic fine particle in the thermoplastic resin upon the formation of a chemical bond with the inorganic fine particle. The functional group capable of forming a chemical bond with the inorganic fine particle is a functional group selected among the following groups:

(wherein R , R R and R each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted aryl group), -SO₃H, -OSO₃H, -CO₂H and -Si (OR¹⁵) _miR¹⁶ ₃-mi (wherein R¹⁵ and R¹⁶ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted aryl group; and ml represents an integer of from 1 to 3) .

The alkyl group preferably has 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, for example, an aralkyl group. The aralkyl group preferably has 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 preferably has 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 preferably has from 2 to 20 carbon atoms, and preferably from 2 to 10 carbon atoms, and examples thereof include an ethynyl group and a 2-phenylethynyl group. The aryl group preferably has 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 as referred to herein includes a heteroaryl group. Examples of the substituent of each of the alkyl group, the alkenyl group, the alkynyl group and the aryl group include, in addition to these alkyl group, alkenyl group, alkynyl group and aryl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom) and an alkoxy group (for example, a methoxy group and an ethoxy group) . R¹¹, R¹², R¹³ and R¹⁴ are each especially preferably a hydrogen atom.

Preferred ranges of R¹⁵ and R¹⁶ are the same as in R¹¹, R¹², R¹³ and R¹⁴. ml is preferably 3.

Of these functional groups, the following groups:

-SO₃H, -CO₂H an -Si ( OR¹⁵ ) _m1R¹⁶ ₃__m1 are preferable ; and the following groups :

and -CO₂H are more preferable.

In the invention, it is especially preferable that the foregoing block copolymer has a functional group selected among the following groups:

-SO₃H, -OSO₃H, , -OH and -Si (OR¹⁵) _m1R¹⁶ ₃__m1 and that the content of the functional group is from 0.05 to 5.0 mmoles/g. Above all, acrylic acid, methacrylic acid, acrylic esters and methacrylic esters each having a hydrophilic substituent in an ester site thereof and styrenes having a hydrophilic substituent in an aromatic ring moiety thereof are preferable as the hydrophilic segment (B) . The vinyl monomer (A) for forming the hydrophobic segment (A) may contain the vinyl monomer (B) within the range where the hydrophobic properties are not hindered. A molar ratio of the vinyl monomer (A) to the vinyl monomer (B) to be contained in the hydrophobic segment (A) is preferably from 100/0 to 60/40.

The vinyl monomer (B) for forming the hydrophilic segment

(B) may contain the vinyl monomer (A) within the range where the hydrophilic properties are not hindered. A molar ratio of the vinyl monomer (B) to the vinyl monomer (A) to be contained in the hydrophilic segment (B) is preferably from 100/0 to 60/40.

The vinyl monomer (A) and the vinyl monomer (B) may be each used singly or in admixture of two or more kinds thereof. The vinyl monomer (A) and the vinyl monomer (B) are each selected depending upon a variety of purposes (for example, adjustment of the acid content, adjustment of the glass transition point (Tg) , adjustment of solubility in an organic solvent or water, adjustment of the stability of a dispersion) .

The content of the functional group is preferably from 0.05 to 5.0 mmoles/g, more preferably from 0.1 to 4.5 mmoles/g, and especially preferably from 0.15 to 3.5 mmoles/g relative to the whole of the block copolymer. When the content of the functional group is too small, there may be the case where the dispersion aptitude is low; and when the content of the functional group is too large, there may be the case where the water solubility becomes too high, or the material composition of the invention is gelated. In the block copolymer, the foregoing functional group may form a salt with a cationic ion such as an alkali metal ion (for example, Na⁺, K⁺) and an ammonium ion.

In the block copolymer, its molecular weight (Mn) is preferably from 1,000 to 100,000, more preferably from 2,000 to 80, 000, and especially preferably from 3, 000 to 50,000. When the molecular weight of the block copolymer is 1,000 or more, there is a tendency that a stable dispersion is easily obtained; and when it is not more than 100,000, there is a tendency that the solubility in an organic solvent is enhanced, and therefore, such is preferable. In the block copolymer to be used in the invention, its refractive index is preferably greater than 1.49, more preferably greater than 1.55, further preferably greater than 1.58, even further preferably greater than 1.60, and especially preferably greater than 1.65. The refractive index as referred to herein is a value measured regarding light at a wavelength of 589 nm by an Abbe's refractometer (for example, "DR-M4", manufactured by Atago Co., Ltd.) .

In the block copolymer to be used in the invention, its glass transition temperature is preferably from 80°C to 400°C, and more preferably from 130°C to 380°C. When the glass transition temperature is 8O⁰C or higher, there is a tendency that the heat resistance is enhanced; and when the glass transition temperature is not higher than 400°C, there is a tendency that the molding processability is enhanced. In the block copolymer to be used in the invention, its light transmittance as reduced in a thickness of 1 mm at a wavelength of 589 nm is preferably 80% or more, and more preferably 85% or more.

Specific examples of the block copolymer are given below (Illustrative Compounds Q-1 to Q-22), but it should not be construed that the block copolymer to be used in the invention is limited thereto. Table 1

Table 2

The block copolymer can be synthesized utilizing living radical polymerization or living ionic polymerization using a method such as protection of a carboxyl group, etc. and introduction of a functional group into the polymer as the need arises. The block copolymer can also be synthesized through radical polymerization from a terminal functional group polymer or connection between terminal functional polymers each other. Above all, in view of the molecular weight control and the percent yield of the block polymer, it is preferable to utilize living radical polymerization or living ionic polymerization. The manufacturing method of the block copolymer is described in, for example, Kobunshi no Gosei to Hanno (Synthesis and

Reaction of Polymer) (1) (edited by The Society of Polymer

Science, Japan and published by Kyoritsu Shuppan Co., Ltd. (1992)); Seimitsu Jugo (Accurate Polymerization) (editedbyThe

Society of Polymer Science, Japan and published by Japan

Scientific Societies Press (1993) ) ; Kobunshi no Gosei to Hanno

(Synthesis and Reaction of Polymer) (1) (edited by The Society of Polymer Science, Japan and published by Kyoritsu Shuppan Co . , Ltd. (1995)); "Telechelic Polymer: Synthesis and Properties, Application" (R. Jerome, et al., Prog. Polym. Sci., Vol. 16, pages 837 to 906 (1991) ) ; "Synthesis of Block or Graft Copolymer by Light" (Y. Yagch, et al., Prog. Polym. Sci., Vol. 15, pages 551 to 601 (1990)); and U.S. Patent No. 5,085,698. These resins may be used singly or in admixture of two or more kinds thereof.

[Additives]

From the viewpoints of uniform dispersibility, fluidity at the time of molding, release properties, weather resistance and the like, in the invention, in addition to the foregoing thermoplastic resin and inorganic fine particle, a variety of additives may be properly compounded. Examples of such additives include a surface treating agent, an antistatic agent, a dispersant, a plasticizer and a releasing agent. Also, in addition to the foregoing thermoplastic resin, a resin not having the foregoing functional agent may be added. Though such a resin is not particularly limited with respect to its type, those having the same optical physical properties, thermal physical properties and molecular weight as in the foregoing thermoplastic resin are preferable.

Though a blending proportion of such an additive varies depending upon the purpose, it is preferably from 0 to 50% by mass, more preferably from 0 to 30% by mass, and especially preferably from O to 20% by mass relative to the total sum of the foregoing inorganic fine particle and thermoplastic resin.

<Surface treating agent> In the invention, in mixing the inorganic fine particle dispersed in water or an alcohol solvent as described later with the thermoplastic resin, a fine particle surface modifying agent other than the foregoing thermoplastic resin may be added for a variety of purposes such as a purpose of enhancing extraction properties or substitution properties into the organic solvent, a purpose of enhancing the uniform dispersibility into the thermoplastic resin, a purpose of lowering the water absorption properties of the fine particle, or a purpose of enhancing the weather resistance. In the surface treating agent, its weight average molecular weight is 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 is preferably one having a structure represented by the following formula (1) : Formula (1)

A-B

In the formula (1) , A represents a functional group capable of forming an arbitrary chemical bond with the surface of the inorganic fine particle in the invention; and B represents a monovalent group having from 1 to 30 carbon atoms and having compatibility or reactivity with a resin matrix containing, as a major component, the thermoplastic resin to be used in the invention or a polymer. Examples of the "chemical bond" as referred to herein include a covalent bond, an ionic bond, a coordination bond and a hydrogen bond.

Preferred examples of the group represented by A are the same as those described above as the functional group capable of bonding with the fine particle to be introduced in the thermoplastic resin of the invention. On the other hand, from the viewpoint of compatibility, the chemical structure of B is preferably the same as or analogous to the chemical structure of the thermoplastic resin which is the maj or component of the resin matrix . In particular, in the invention, from the viewpoint of realizing a high refractive index, it is preferable that the chemical structure of B has an aromatic ring similar to the foregoing thermoplastic resin.

Examples of the surface treating agent which is 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, phenylphosphonic acid, phenylphosphonic acid monophenyl ester, KAYAMER PM-21 (a trade name, manufactured by Nippon Kayaku Co. , Ltd. ) , KAYAMER PM-2 (a trade name, manufactured by Nippon Kayaku Co., Ltd.), benzenesulfonic acid, naphthalenesulfonic acid, p-octylbenzenesulfonic acid and silane coupling agents described in JP-A-5-221640, JP-A-9-100111 and JP-A-2002-187921. However, it should not be construed that the invention is limited thereto.

Such a surface treating agent may be used singly or in combination of plural kinds thereof.

The total amount of the addition amount of such a surface treating agent is preferably from 0.01 to 2 times, more preferably from 0.03 to 1 time, and especially preferably from 0.05 to 0.5 times the amount of the inorganic fine particle in terms of a mass.

In the case where the glass transition temperature of the resin in the invention is high, there is a possibility that molding of the material composition is not always easy. For that reason, for the purpose of decreasing the molding temperature of the material composition of the invention, a plasticizer may be used. Though the structure of the plasticizer is not particularly limited within the range where the transparency of the molding is not hindered, a plasticizer having a structure represented by the following formula (2) is preferable as the plasticizer which can be used in the invention.

the formula (2), B¹ and B² each represents an alkyl group or an arylalkyl group each having from 6 to 18 carbon atoms; m represents 0 or 1; and X represents any one of the following divalent bonding groups.

Also, in the compound represented by the formula (2) , an arbitrary alkyl group or arylalkyl group can be chosen as B¹ and B² within the range where the carbon atom number is from 6 to 18. When the carbon atom number is less than 6, there may be the case where since the molecular weight is too low, the melting temperature of the polymer boils, thereby forming bubbles. Also, when the carbon atom number exceeds 18, there may be the case where the compatibility with the polymer becomes worse so that the addition effect is insufficient.

Specific examples of B¹ and B² include linear alkyl groups (for example, an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, an n-octadecyl group) ; branched alkyl groups (for example, a 2-hexyldecyl group, a methyl-branched octadecyl group) ; and arylalkyl groups (for example, a benzyl group, a 2-phenylethyl group) . Also, specific examples of the compound represented by the foregoing formula (2) include the following compounds. Of these, W-I (a trade name: KP-L155, manufactured by Kao Corporation) is preferable.

<Antistatic agent> In order to adjust the dielectric strength of the organic-inorganic hybrid composition of the invention, an antistatic agent can be added. In the organic-inorganic hybrid composition of the invention, there may be the case where the inorganic fine particle per se, which is added for the purpose of improving the optical properties, contributes to an antistatic effect as a separate effect. In the case where the antistatic agent is added, examples thereof include an anionic antistatic agent, a cationic antistatic agent, a nonionic antistatic agent, an ampholytic antistatic agent, a polymer antistatic agent and an antistatic fine particle. Such an antistatic agent may be used in combination of two or more kinds thereof. Examples thereof include compounds described in JP-A-2007-4131 and JP-A-2003-201396.

Though the addition amount of the antistatic agent is divergent, it is preferably from 0.001 to 50% by mass, more preferably from 0.01 to 30% by mass, and especially preferably from 0.1 to 10% by mass of the total solids content. <Others>

In addition to the foregoing components, for the purpose of improving the moldability, known releasing agents such as a modified silicone oil may be added; and for the purpose of improving the light fastness or heat deterioration, known deterioration preventive agents such as hindered phenol based, amine based, phosphorus based or thioether based deterioration preventive agents may be properly added. In the case where such a material is compounded, it is preferably added in an amount of from about 0.1 to 5% by mass relative to the total solids content of the material composition.

[Manufacturing method of organic-inorganic hybrid composition] The inorganic fine particle to be used in the invention is bound with the thermoplastic resin having the foregoing functional group in at least one polymer chain end and dispersed in the resin.

Since the inorganic fine particle to be used in the invention is small in particle size and high in surface energy, when isolated as a solid, it is difficult to be re-dispersed. Therefore, it is preferable that the inorganic fine particle is mixed with the foregoing thermoplastic resin in a dispersed state in a solution to form a stable dispersion. Preferred examples of the manufacturing method of the hybrid material include (1) a method in which an inorganic fine particle is surface treated in the presence of the foregoing surface treating agent, the surface-treated inorganic fine particle is extracted into an organic solvent, and the extracted inorganic fine particle is uniformly mixed with the foregoing thermoplastic resin to manufacture a hybrid material of the inorganic fine particle and the thermoplastic resin; and (2) a method in which both an inorganic fine particle and a thermoplastic resin are uniformly mixed using a solvent capable of uniformly dispersing or dissolving the both therein to manufacture a hybrid material of the inorganic fine particle and the thermoplastic resin.

In the case where a hybrid material of the inorganic fine particle and the thermoplastic resin is manufactured by the foregoing method (1) , a water-insoluble solvent such as toluene, ethyl acetate, methyl isobutyl ketone, chloroform, dichloroethane, dichloromethane, chlorobenzene and methoxybenzene is used as the organic solvent. Though the surface treating agent to be used for extracting the inorganic fine particle into the organic solvent and the thermoplastic resin may be the same kind or a different kind, as to the surface treating agent to be preferably used, those described above in the <Surface treating agent> section are exemplified. In mixing the inorganic fine particle extracted into the organic solvent and the thermoplastic resin, additives such as a plasticizer, a releasing agent and a polymer of other type may be added as the need arises.

In the case where the foregoing method (2) is employed, a single or mixed solvent of hydrophilic polar solvents (for example, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, benzyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, l-methoxy-2-propanol, tert-butanol, acetic acid, propionic acid) is preferably used as the solvent. Alternatively, a mixed solvent of a water-insoluble resin (for example, chloroform, dichloroethane, dichloromethane, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, chlorobenzene, methoxybenzene) and the foregoing polar solvent is preferably used as the solvent. On that occasion, apart from the foregoing thermoplastic resin, adispersant, a plasticizer, a releasing agent or a polymer of other type may be added as the need arises. In using a fine particle ₍ dispersed in water/methanol, it is preferable that after adding a hydrophilic solvent capable of dissolving the thermoplastic resin therein at a higher boiling point than that of water/methanol, the water/methanol is concentrated and distilled off, thereby substituting a dispersion of the fine particle into the polar organic solvent, followed by mixing with the resin. On that occasion, the foregoing surface treating agent may be added.

The solution of the material composition obtained in the foregoing method (1) or (2) can be subjected to cast molding as it is, to obtain a molding. However, in the invention, it is especially preferable that after removing the solvent from the solution by a method such as concentration, freeze-drying and reprecipitation from an appropriate poor solvent, a powdered solid is molded by a known method such as injection molding and compression molding.

[Article]

By forming the organic-inorganic hybrid composition of the invention to a particular shape (for example by molding) , it is possible to manufacture the article of the invention. As to the article of the invention, one exhibiting the refractive index and optical properties described above for the material composition is useful.

Also, the article of the invention is especially useful for high-refractive index optical components having a thickness of 0.1 mm or more at maximum. It is preferable to apply the article of the invention to optical components having a thickness of from 0.1 to 5 mm; and it is especially preferable to apply the article of the invention to optical components having a thickness of from 1 to 3 mm. In manufacturing such a thick article by a solution casting method, the solvent is hardly discharged so that molding is usually not easy. However, by using the material composition of the invention, molding is easy, a complicated shape such as non-spheres can be easily imparted, and a material having good transparency can be formed while utilizing high refractive index properties of the fine particle.

[Optical components] The foregoing article is an article having high refraction properties, light transmission properties and lightweight properties and having excellent optical properties. The optical component of the invention is configured of such an article. The type of the optical component of the invention is not particularly limited. In particular, the optical component of the invention can be favorably utilized as an optical component utilizing excellent optical properties of the organic-inorganic hybrid composition, especially as an optical component capable of transmitting light therethrough (so-called passive optical component) . Examples of optical functional devices provided with such an optical component include a variety of display devices (for example, liquid crystal displays, plasma displays), a variety of projector devices (for example, OHP, liquid crystal projectors) , optical fiber communication devices (for example, optical waveguides, optical amplifiers) and imaging devices (for example, cameras, video cameras) .

Also, examples of the passive optical component to be used in an optical functional device include lenses, prisms, panels (plate-like moldings) , films, optical waveguides (for example, film forms, fiber forms) and optical discs. If desired, such a passive optical component may be of a multilayered structure provided with an arbitrary coating layer such as arbitrary additional functional layers, for example, a protective layer for preventing mechanical damages on the coated surface due to friction or abrasion, a light absorbing layer for absorbing light beams of an undesired wavelength which become a cause for deteriorating the inorganic particle or base material or the like, a transmission-blocking layer for suppressing or preventing the transmission of a reactive low-molecular weight molecule such as water and an oxygen gas, an antiglare layer, an antireflection layer and a low-refractive index layer. Specific examples of such an arbitrary coating layer include a transparent conductive membrane or a gas barrier membrane composed of an inorganic oxide coating layer; and a gas barrier membrane or a hard coat composed of an organic material coating layer. As the coating method, there can be employed known coating methods such as a vacuum vapor deposition method, a CVD method, a sputtering method, a dip coating method and a spin coating method.

The optical component using the material composition of the invention is especially favorable for a lens base material. The lens base material manufactured using the material composition of the invention has high refraction properties, light transmission properties and lightweight properties and is excellent in optical properties. Also, by properly adjusting the type of the monomer constituting the material composition and the amount of the inorganic fine particle to be dispersed, it is possible to arbitrarily adjust the refractive index of the lens base material.

The "lens base material" as referred to in the invention refers to a single member capable of exhibiting a lens function. A membrane or a member can be provided on the surface or surroundings of the lens base material depending upon the use circumference or utilization of the lens. For example, a protective membrane, an antireflection membrane, a hard coat membrane and the like can be formed on the surface of the lens base material . Also, the surroundings of the lens base material can be put in and fixed to a base material holding frame or the like. However, such a membrane or frame is a member to be added to the lens base material as referred to in the invention and should be distinguished from the lens base material per se as referred to in the invention. In utilizing the lens base material in the invention as a lens, the lens base material per se of the invention may be solely used as a lens, or as described previously, it may be added to a membrane or frame and then used as a lens. The type and shape of the lens using the lens base material of the invention is not particularly limited. The lens base material of the invention is used for, for example, spectacle lenses, optical instrument lenses, optoelectronic lenses, laser lenses, pickup lenses, vehicle-mounted camera lenses, mobile phone camera lenses, digital camera lenses, OHP lens, lenses for configuring a micro lens array.

EXAMPLES

The characteristics of the invention are hereunder described in more detail with reference to the following

Examples. Materials, use amounts, proportions, treatment contents, treatment procedures and the like as shown in the following Examples can be properly changed. In consequence, it should not be construed that the scope of the invention is limitedly interpreted.

[Analysis and evaluation methods]

In the following Examples, the respective analysis and evaluation methods were carried out in the following manners. (1) Observation by transmission electron microscope (TEM) :

The observation was carried out by "H-9000 UHR model transmission electron microscope", manufactured by Hitachi, Ltd. (accelerating voltage: 20OkV, degree of vacuum at the time of observation: about 7.6 x 10^-9 Pa). (2) Measurement of light transmittance :

A resin to be measured was molded to prepare a substrate having a thickness of 1.0 mm, which was then measured for light transmittance using a spectrophotometer for ultraviolet and visible region (UV-3100, manufactured by Shimadzu Corporation) .

(3) Measurement of refractive index:

The measurement was carried out by light at a wavelength of 589 nm using an Abbe's refractometer ("DR-M4", manufactured by Atago Co., Ltd.).

(4) Measurement of X-ray diffraction (XRD) spectrum:

The measurement was carried out at 23°C using "RINT 1500", manufactured by Rigaku Corporation (X-ray source: copper Ka rays, wavelength: 1.5418 angstroms) (5) Measurement of molecular weight:

The measurement was carried out for weight average molecular weight using tetrahydrofuran as a solvent by a GPC analyzer using columns of "TSKgel GMHxL", "TSKgel G400OHxL" and "TSKgel G2000HxL" (all of which are manufactured by Tosoh Corporation) . The molecular weight was measured by differential refractometer detection and expressed as reduced into polystyrene.

[Preparation of inorganic fine particle dispersion] (1) Preparation of titanium oxide fine particle dispersion: A dispersion of a titanium oxide fine particle was prepared in conformity with a method described in Synthesis Example 9 of JP-A-2003-73559. The formation of an anatase type titanium oxide fine particle (number average particle size: about 5 nm) was confirmed by XRD and TEM. The fine particle had a refractive index of 2.5.

(2) Synthesis of zirconium oxide fine particle:

A zirconium oxychloride solution having a concentration of 50 g/L was neutralized with a 48% sodium hydroxide aqueous solution to obtain a zirconium hydrate suspension. This suspension was filtered and then washed with ion exchanged water to obtain a zirconium hydrate cake . This cake was adjusted with ion exchanged water as a solvent so as to have a concentration of 15% by mass as reduced into zirconium oxide, charged in an autoclave and then subjected to a hydrothermal treatment under a pressure of 150 atmospheres at 15O°C for 24 hours, thereby obtaining a zirconium oxide fine particle suspension. The formation of the zirconium oxide fine particle having a number average particle size of 5 nm was confirmed by TEM. The fine particle had a refractive index of 2.1.

(3) Preparation of zirconium oxide fine particle toluene dispersion:

The zirconium oxide fine particle suspension as synthesized in the foregoing (2) and a toluene solution having KAYAMER PM-21 (manufactured by Nippon Kayaku Co., Ltd.) dissolved therein were mixed, the mixture was stirred at 5O⁰C for 8 hours, and the toluene solution was extracted to prepare a zirconium oxide fine particle toluene dispersion. (4) Preparation of zirconium oxide dimethylacetamide dispersion:

500 g of N, N' -dimethylacetamide was added to 500 g of the zirconium oxide fine particle suspension (concentration: 15% by mass) as synthesized in the foregoing (2), the mixture was concentrated in vacuo to an extent of not more than about 500 g to achieve solvent substitution, and the concentration was then adjusted by the addition of N, N' -dimethylacetamide, thereby obtaining a 15% by mass zirconium oxide dimethylacetamide dispersion.

[Synthesis of resin]

(1) Synthesis of thermoplastic resin (Q-I) :

A mixed solution consisting of 2.1 g of tert-butyl acrylate, 0.72 g of tert-butyl 2-bromo-2-methylpropionate, 0.46 g of copper (I) bromide, 0.56 g of N, N, N' ,N' ,N",N"-pentamethyl diethylenetetramine and 9 mL of methyl ethyl ketone was prepared and purged with nitrogen. The resulting mixed solution was stirred at an oil bath temperature of 80°C for one hour, and 136.2 g of styrene was added dropwise under a nitrogen gas stream. The mixture was stirred at an oil bath temperature of 90°C for 16 hours, and after returning to room temperature, 100 mL of ethyl acetate and 30 g of alumina were added, followed by stirring for 30 minutes. This reaction solution was filtered, and the filtrate was added dropwise to an excess of methanol. A formed precipitate was collected by filtration, washed with methanol and then dried to obtain 61 g of a resin. This resin was dissolved in 300 mL of toluene, 6 g of p-toluenesulfonic acid monohydrate was added, and the mixture was heat refluxed for 3 hours. This reaction solution was added dropwise to an excess of methanol. A formed precipitate was collected by filtration, washed with methanol and then dried to obtain 55 g of a block copolymer Q-I. As a result of the measurement by GPC, the resin was found to have a number average molecular weight of 32, 000 and a weight average molecular weight of 35,000. Also, as a result of the measurement by an Abbe's refractometer, the resin was found to have a refractive index of 1.59. (2) Synthesis of thermoplastic resin (Q-2) : A mixed solution consisting of 12.6 g of tert-butyl acrylate, 0.72 g of tert-butyl 2-bromo-2-methylpropionate, 0.46 g of copper (I) bromide, 0.56 g of N, N, N' ,N' ,N",N"-pentamethyl diethylenetetramine and 9 mL of methyl ethyl ketone was prepared and purged with nitrogen. The resulting mixed solution was stirred at an oil bath temperature of 80⁰C for one hour, and 136.2 g of styrene was added dropwise under a nitrogen gas stream. The mixture was stirred at an oil bath temperature of 90°C for 16 hours, and after returning to room temperature, 100 mL of ethyl acetate and 30 g of alumina were added, followed by stirring for 30 minutes. This reaction solution was filtered, and the filtrate was added dropwise to an excess of methanol. A formed precipitate was collected by filtration, washed with methanol and then dried to obtain 70 g of a resin. This resin was dissolved in 300 mL of toluene, 6 g of p-toluenesulfonic acid monohydrate was added, and the mixture was heat refluxed for 3 hours. This reaction solution was added dropwise to an excess of methanol. A formed precipitate was collected by filtration, washed with methanol and then dried to obtain 67 g of a block copolymer Q-2. As a result of the measurement by GPC, the resin was found to have a number average molecular weight of 31, 000 and a weight average molecular weight of 36,000. Also, as a result of the measurement by an Abbe' s refractometer, the resin was found to have a refractive index of 1.59.

(3) Synthesis of thermoplastic resin (Q-14):

A mixed solution consisting of 2.1 g of tert-butyl acrylate, 0.72 g of tert-butyl 2-bromo-2-methylpropionate, 0.46 g of copper (I) bromide, 0.56 g of N, N, N' ,N' ,N",N"-pentamethyl diethylenetetramine and 9 mL of methyl ethyl ketone was prepared and purged with nitrogen. The resulting mixed solution was stirred at an oil bath temperature of 8O⁰C for one hour, and 160.7 g of methyl methacrylate was added dropwise under a nitrogen gas stream. The mixture was stirred at an oil bath temperature of 90°C for 8 hours, and after returning to room temperature, 100 mL of ethyl acetate and 30 g of alumina were added, followed by stirring for 30 minutes. This reaction solution was filtered, and the filtrate was added dropwise to an excess of methanol. A formed precipitate was collected by filtration, washed with methanol and then dried to obtain 72 g of a resin. This resin was dissolved in 300 mL of toluene, 6 g of p-toluenesulfonic acid monohydrate was added, and the mixture was heat refluxed for 3 hours. This reaction solution was added dropwise to an excess of methanol. A formed precipitate was collected by filtration, washed with methanol and then dried to obtain 68 g of a block copolymer Q-14. As a result of the measurement by GPC, the resin was found to have a number average molecular weight of 26, 000 and a weight average molecular weight of 28,000. Also, as a result of the measurement by an Abbe's refractometer, the resin was found to have a refractive index of 1.49. (4) Synthesis of polymethyl methacrylate (PMMA) :

5.00 g of methyl methacrylate and 0.25 g of azobisisobutyronitrile were added in 2-butanol, and the mixture was polymerized under a nitrogen gas stream at 70°C, thereby synthesizing PMMA. A weight average molecular weight was found to be 100,000.

[Preparation of organic-inorganic hybrid composition and preparation of transparent article (lens base material) ] [Example 1]

In the foregoing zirconium oxide dimethylacetamide dispersion, a resin (Q-I) and a surface treating agent (4-propylbenzoic acid) were added in a mass ratio of ZrO₂ solid/Q-l/4-propylbenzoic acid of 42/50/8, uniformly .stirred and mixed, and the dimethylacetamide solvent was then concentrated in vacuo by heating. The concentration residue was heat compression molded in a die having a SUS-made surface (temperature: 180⁰C, pressure: 13.7 Pa, time: 2 minutes), thereby obtaining a transparent article (lens base material) having a thickness of 1 mm.

[Example 2] A transparent article (lens base material) of Example 2 was obtained in the same manner as in Example 1, except that in Example 1, the mass ratio of the ZrO₂ solid to the resin to the surface treating agent was changed to a mass ratio of ZrO₂ solid/Q-l/3-phenylpropinic acid of 50/42/8.

[Example 3]

A transparent article (lens base material) of Example 3 was obtained in the same manner as in Example 1, except that in Example 1, the mass ratio of the ZrO₂ solid to the resin to the surface treating agent was changed to a mass ratio of ZrO₂ solid/Q-l/4-propylbenzoic acid of 46/45/9.

[Example 4] The foregoing titanium oxide fine particle dispersion was added dropwise in a chloroform solution having a resin (Q-I) and a surface treating agent (4-propylbenzoic acid) dissolved therein at ordinary temperature over 5 minutes while stirring, and the solvent was then distilled off from the obtained mixed solution (mass ratio: TiO₂ solid/Q-l/4-propylbenzoic acid = 31/61/8) . The concentration residue was molded in the same manner as in Example 1, thereby obtaining a transparent article (lens base material) of Example 4.

[Example 5]

A transparent article (lens base material) of Example 5 was obtained in the same manner as in Example 1, except that in Example 1, the mass ratio of the ZrO₂ solid to the resin to the surface treating agent was changed to a mass ratio of ZrO₂ solid/Q-14/3-phenylpropinic acid of 52/38/10.

[Example 6]

A transparent article (lens base material) of Example 6 was obtained in the same manner as in Example 4, except that in Example 4, the mass ratio of the TiO₂ solid to the resin to the surface treating agent was changed to a mass ratio of TiO₂ solid/Q-14/4-propylbenzoic acid of 41/49/10.

[Examples 7 to 12 and Comparative Examples 1 to 3] Each of transparent articles (lens base materials) of Examples 7 to 12 and Comparative Examples 1 to 3 was manufactured in the following procedures. The type of a resin and the type and use amount of an inorganic fine particle used in the following procedures are shown in the following Table 3. However, in Comparative Example 1, only the resin was molded without adding the inorganic fine particle.

A titanium oxide fine particle or a zirconium oxide fine particle dispersed in toluene was added dropwise in an anisole solution of the resin over 5 minutes, the mixture was stirred for one hour, and the solvent was then removed. The obtained organic-inorganic hybrid composition was heat molded at 220°C, thereby obtaining a article (lens base material) having a thickness of 1 mm.

[Test Example]

Each of the articles (lens base materials) as prepared in Examples 1 to 12 and Comparative Examples 1 to 3 was cut, and its cross section was observed by TEM to confirm whether or not the inorganic fine particle was uniformly dispersed in the resin. Furthermore, the measurement of light transmittance and the measurement of refractive index were carried out. The results obtained are shown in the following Table 3.

Table 3

(Note) Polystyrene: Aldrich's product No. 18, 242-7, Mw: 280,000

As is clear from Table 3, according to the invention, optical components having a refractive index of greater than 1.60 and having good transparency were obtained (Examples 1 to 12) . When polystyrene (Comparative Example 2) or PMMA (Comparative Example 3) was used, the inorganic fine particle could not be uniformly dispersed, and cloudiness was generated, whereby a transparent lens was not obtained. Furthermore, in Comparative Example 1 not using an inorganic fine particle, the refractive index was lower than 1.60.

Also, all of the material compositions of Examples 1 to 12 had a dielectric strength falling within the range of from -1.0 to 7.0 kV and a glass transition temperature falling within the range of from 100 to 400°C and when kept at 250⁰C for 2 hours, had a volatile component content of not more than 2% by mass and a percentage of saturated water absorption of 0.5% by mass.

Also, it was confirmed that by using the organic-inorganic hybrid composition of the invention, a lens shape can be accurately formed with good productivity in conformity with the shape of a die such as a concave lens and a convex lens.

INDUSTRIAL APPLICABILITY

The optical component of the invention contains an organic-inorganic hybrid composition having high refraction properties, light transmission properties and lightweight properties. According to the invention, it is possible to relatively easily provide an optical component having an arbitrarily adjusted refractive index. Also, it is easy to provide an optical component having good mechanical strength and heat resistance. For that reason, the invention is useful for providing a wide-ranging optical component such as a lens with a high refractive index and high in industrial applicability.

While the present invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. The present disclosure relates to the subject matter contained in Japanese Patent Application No. 195491/2007 filed on July 27, 2007, which is expressly incorporated herein by reference in its entirety. All the publications referred to in the present specification are also expressly incorporated herein by reference in their entirety.

The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The description was selected to best explain the principles of the invention and their practical application to enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention not be limited by the specification, but be defined claims set forth below.

Claims

1. An organic-inorganic hybrid composition comprising a block copolymer constituted of a hydrophobic segment and a hydrophilic segment and an inorganic fine particle having a number average particle size of from 1 nm to 15 nm, the organic-inorganic hybrid composition having a refractive index of 1.60 or more at a wavelength of 589 nm.

2. The organic-inorganic hybrid composition according to claim 1, wherein the block copolymer has a functional group capable of forming a chemical bond with the inorganic fine particle .

3. The organic-inorganic hybrid composition according to claim 1 or 2, wherein the block copolymer is a thermoplastic resin having a functional group selected among the following groups:

wherein R¹¹, R¹³ and R¹⁴ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted aryl group,

-SO₃H, -OSO₃H, -CO₂H and -Si (OR¹⁵) _m1R¹⁶ ₃-_m1, wherein R¹⁵ and R¹⁶ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted aryl group; and ml represents an integer of from 1 to 3.

4. The organic-inorganic hybrid composition according to any one of claims 1 to 3, wherein the content of the functional group is from 0.05 to 5.0 mmoles/g relative to the whole of the block copolymer.

5. The organic-inorganic hybrid composition according to any one of claims 1 to 4, wherein the inorganic fine particle is a metal oxide fine particle having a refractive index of from 1.90 to 3.00.

6. The organic-inorganic hybrid composition according to any one of claims 1 to 5, wherein the inorganic fine particle is a fine particle containing zirconium oxide, zinc oxide or titanium oxide.

7. The organic-inorganic hybrid composition according to any one of claims 1 to 6, wherein the inorganic fine particle is contained in an amount of 20% by mass or more.

8. The organic-inorganic hybrid composition according to any one of claims 1 to 7, which is thermoplastic.

9. An article obtained by forming the organic-inorganic hybrid composition of any one of claims 1 to 8.

10. The article according to claim 9, having a light transmittance as reduced in a thickness of 1 mm of 70% or more at a wavelength of 589 nm.

11. The article according to claim 9 or 10, having a maximum thickness of 0.1 mm or more.

12. An optical component comprising the article of any one of claims 9 to 11.

13. The optical component according to claim 12, which is a lens base material.