JP2006215295A - Composition for optical material and optical material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical material having a high refractive index, excellent light scattering property and environmental characteristics. <P>SOLUTION: A composition for the optical material comprising organic and inorganic components is provided, wherein the composition contains an inorganic component comprising tin oxide, an organic component having a polymerizable functional group and a polymerization initiator. The optical material obtained from the composition is also provided. The inorganic component is obtained from a tin alkoxide or a product prepared by polymerizing a hydrolyzate thereof. At least one selected from the group consisting of (meth)acrylic acid, (meth)acrylic esters, epoxy compounds and sulfur-containing organic compounds is used as the organic component. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical material composition suitable for forming an optical element used in an optical system such as an imaging optical system such as a camera, a projection optical system such as a display device, an observation optical system such as an image display device, and the like. The present invention relates to an optical material obtained by polymerization, and relates to an optical material that is excellent in light scattering properties, environmental characteristics, and moldability and that can obtain a desired optical constant.

  In recent years, optical systems such as imaging modules used for silver salt film and digital cameras, video cameras or mobile phones with cameras, videophones or camera doorphones, have become a major issue in terms of small size, light weight and low cost. . Therefore, in these optical systems, high refractive index optical materials that easily reduce the size of optical elements, low dispersion and high dispersion optical materials that are easy to correct chromatic aberration, or optical materials that are easy to mold and inexpensive are used. It has become.

  Examples of such an optical material include optical glass, thermoplastic optical resin, low melting point glass for press molding at a high temperature to obtain a desired optical element, or polymerization with heat or light while molding to obtain an optical element of a desired shape. Therefore, thermosetting resins, ultraviolet curable resins and the like have been used.

  In recent years, an organic-inorganic composite material using an inorganic compound and an organic compound as an optical material for an optical element, for example, a fine particle-dispersed optical material in which inorganic fine particles having a particle diameter of several to 150 nm are uniformly dispersed in a synthetic resin. Proposed.

  In the case of such a fine particle dispersion type optical material, that is, when using an organic-inorganic composite material containing a non-uniform component such as a particle smaller than the wavelength used in the optical system, the non-uniform component having a small particle size affects the optical performance. Therefore, as an optical material of an optical element of a white optical system whose operating wavelength range is approximately 400 to 800 nm, a fine particle dispersion type optical system including fine particles which are non-uniform components of about 30 nm to 100 nm is used. Materials have been proposed.

For example, an optical resin composition that realizes a high refractive index obtained by uniformly dispersing fine diamond powder having a particle diameter of 1 to 150 nm in a synthetic resin has been proposed (for example, Patent Document 1).
Further, an ultrafine particle dispersion type optical material that realizes a high refractive index by dispersing metal powder or metal oxide powder having a particle diameter of 5 to 100 nm in an organic resin has been proposed (for example, Patent Document 2).
Further, fine particles of titanium and silicon composite metal oxide (Si _x —Ti _(1-x) O ₂ ), TiO ₂ , Nb ₂ O ₅ , ITO, Cr ₂ O ₃ , BaTiO _3, etc. have a particle size of 2 to 2. An optical material that realizes high dispersion by dispersing 100 nm fine particles in a thermoplastic amorphous resin has been proposed (for example, Patent Document 3).
Japanese Patent No. 2867388 JP 2000-44811 A Japanese Patent No. 3517625

An optical element having an aspherical optical effective surface has many features such as excellent aberration correction performance. However, using an optical glass to make an aspherical shape complicates the processing process and reduces time. As a result, there was a problem in manufacturing mass-produced products.
In addition, a method of manufacturing an optical element by molding using a glass having a relatively low melting point is known, but in this method, an optical effective surface of the optical element is obtained by using a molding die processed into a predetermined shape. However, there is a problem that it is difficult to form a large-diameter or large-thickness element, or there is a problem in the life of a mold for glass molding.

  In addition, optical thermoplastic resins and ultraviolet curable resins can be molded into large-diameter or complex-shaped elements, so that they have the advantage of excellent moldability and mass productivity, but can be selected as an optical material with refractive index and dispersion. There is a problem that the range is narrow and the optical system is limited in size and weight or performance.

On the other hand, fine-particle dispersed organic-inorganic composite materials that have been proposed in recent years have the advantage of being able to be molded into complex-shaped elements, have excellent moldability and transparency, and have the advantage of being relatively easy to mass-produce. With the materials up to this point, the range of refractive index and dispersion that can be selected is limited, and there is a problem in that the reduction in size and weight or performance of the optical system is limited. In particular, a material having a high refractive index and low dispersion has not been realized.
Further, the optical element made of the fine particle dispersion type organic-inorganic composite material has a problem that the light scattering property is large because fine particles are not sufficiently dispersed. The light scattering property is an index of scattered light inside the optical element, and greatly affects the characteristics of the optical element. For example, an optical element having a high intensity of scattered light has an inferior characteristic because an image formed by light transmitted through the optical element is blurred even if there is no aberration of the optical element.

The light scattering property is caused by the material constituting the optical element itself, and the light is scattered when the inside of the optical element is not optically uniform, that is, when the refractive index and transmittance are not uniform. An optical element having a long optical path length within a single optical element such as a prism or a waveguide, such as an organic-inorganic composite material containing fine particles smaller than the wavelength used for the optical system, In an optical element for an optical system that requires high optical performance of an optical element itself such as a microscope or a high-definition digital camera, the size of scattered light becomes a problem.
The present invention has been made in view of such conventional problems, and has a wide range of possible refractive index and dispersion, optical properties for forming an optical element excellent in optical properties including light scattering properties and moldability. The material is provided.

The present invention is an optical material composition comprising an organic component and an inorganic component, comprising an inorganic component comprising a tin oxide, an organic component having a polymerizable functional group, and a polymerization initiator.
In the composition for an optical material, the content of the inorganic component is 0.1 to 70% by mass when the tin oxide with respect to the total mass of the optical material is converted into tin (IV) oxide.

The optical material composition further includes at least one second inorganic component obtained from the metal alkoxide represented by Chemical Formula 1 or a hydrolyzate thereof.
Chemical formula 1
R ¹ _a R ² _b M (OR ³ ) _c
(R ¹ and R ² are the same or in different organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ³ is C 1-6 alkyl group or aryl group, M is selected from the group consisting of Al, Be, Cu, Ge, Hf, La, Nb, Mg, Sc, Si, Ta, Ti, V, W, Zn, Zr At least one kind of metal element, a and b are 0 to 2, and c = m− (a + b) where m is the valence of the metal element M.)
In the chemical formula 1, the metal element M is the composition for an optical material as described above, which is at least one selected from the group consisting of Al, Si, and Ti.

In the optical material composition described above, the inorganic component is obtained by polymerizing a tin alkoxide represented by the following chemical formula 2 or a hydrolyzate thereof.
Chemical formula 2
R ⁴ _d Sn (OR ⁵ ) _4-d
(R ⁴ is an organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ⁵ is an alkyl having 1 to 6 carbon atoms. Group or aryl group, d is 0 to 1)
In the composition for an optical material, the inorganic component is tin oxide particles having an average particle size of 20 nm or less and a 90% particle size of 30 nm or less.
In the composition for optical materials, the organic component is at least one selected from the group consisting of methacrylic acid, acrylic acid, methacrylic acid ester or acrylic acid ester, an epoxy compound, and a sulfur-containing organic compound.

In an optical material composed of an organic component and an inorganic component, an optical material is obtained by polymerizing a composition containing an inorganic component composed of tin oxide, an organic component having a polymerizable functional group, and a polymerization initiator.
Moreover, it is the said optical material whose content of an inorganic component is 0.1-70 mass% in conversion of tin oxide with respect to the total mass of an optical material into a tin (IV) oxide.
The optical material further includes at least one second inorganic component selected from metal alkoxide represented by Chemical Formula 1 or a hydrolyzate thereof.
Chemical formula 1
R ¹ _a R ² _b M (OR ³ ) _c
(R ¹ and R ² are the same or in different organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ³ is C 1-6 alkyl group or aryl group, M is selected from the group consisting of Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, W, Zn, Zr At least one kind of metal element, a and b are 0 to 2, and c = m− (a + b) where m is the valence of the metal element M.)

In the chemical formula 1, the optical material is the optical material in which the metal element M is at least one selected from the group consisting of Al, Si, and Ti.
The optical material as described above, wherein the inorganic component is obtained by polymerizing a tin alkoxide represented by the following chemical formula 2 or a hydrolyzate thereof.
Chemical formula 2
R ⁴ _d Sn (OR ⁵ ) _4-d
(R ⁴ is an organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ⁵ is an alkyl having 1 to 6 carbon atoms. Group or aryl group, d is 0 to 1)
In addition, the inorganic particle component is the optical material which is tin oxide particles having an average particle size of 20 nm or less and a 90% particle size of 30 nm or less. The organic component is methacrylic acid, acrylic acid, methacrylic acid ester. Or it is the said optical material which is at least 1 sort (s) chosen from the group which consists of an acrylic ester, an epoxy compound, a sulfur containing organic compound, and an aromatic containing organic compound.
When the refractive index nd and Abbe number νd of the d-line of the optical material are shown on the vertical axis and the horizontal axis, respectively, (nd, νd) is (1.62, 22), (1.88, 25), The optical material having the optical constant in the region surrounded by (1.57, 58) and (1.47, 58).

  The optical material produced by the composition for optical material of the present invention has a wide range of possible refractive index and dispersion, enables high performance of the optical system, and is excellent in light scattering property and environmental resistance. In addition, since the composition for optical materials of the present invention is in a liquid state at around room temperature, it has high workability capable of producing an optical element having a complicated shape in a short time without applying high temperature or high pressure. Effects such as reduction in size and weight and improvement in production efficiency can be obtained.

The present invention relates to an organic-inorganic composite material with less light scattering by an optical material obtained by polymerizing a composition for an optical material containing an inorganic component made of tin oxide, an organic component having a polymerizable functional group, and a polymerization initiator. It has been found that an optical material comprising
In the composition for optical materials of the present invention, the inorganic component composed of tin oxide is an essential component for changing the optical characteristics. The inorganic component made of tin oxide is preferably 0.1% by mass or more and 70% by mass or less in terms of tin (IV) oxide based on the total mass of the composition for optical materials.
If the amount is less than 0.1% by mass, the effect of adding tin oxide is small. If the amount exceeds 70% by mass, problems such as poor light scattering and difficulty in forming into a desired shape occur.
More preferably, it is 10 mass% or more and 45 mass% or less. If the addition amount is within this range, the light scattering property is good.

The tin oxide component used as an inorganic component in the present invention consists of fine particles having a size that does not adversely affect light transmittance, scattering, etc., and is dispersed in the composition for optical materials and the optical material obtained by curing. Exist.
As the tin oxide component, a tin oxide component produced by polymerizing a tin alkoxide represented by the following chemical formula 2 or a hydrolyzate thereof can be used.
Chemical formula 2
R ⁴ _d Sn (OR ⁵ ) _4-d
(R ⁴ is an organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ⁵ is an alkyl having 1 to 6 carbon atoms. Group or aryl group, d is 0 to 1)

  Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a normal butyl group, and an isobutyl group. Examples of the halogenated alkyl group include a trichloromethyl group, a trifluoromethyl group, and a pentachloroethyl group. Examples of the aryl group include a phenyl group and a styryl group. A methyl group and a phenyl group are preferable. Specific examples of tin alkoxide or its hydrolyzate are tin tetramethoxide, tin tetraethoxide, tin tetrapropoxide, tin tetrabutoxide, tin methyl trimethoxide, tin methyl triethoxide, tin methyl tributoxide, tin phenyl. Examples thereof include trimethoxide, tin phenyl triethoxide, and hydrolysates thereof.

  When an inorganic component produced from tin alkoxide is used as the tin oxide, the type and amount of dilution solvent in the condensation polymerization reaction of tin alkoxide, the type and amount of catalyst, the reaction temperature, and the time are related to the particle size. The molecular weight, refractive index, and crystallinity and density related to dispersion can be adjusted.

In addition, fine particles produced by pulverizing solid tin oxide into fine particles, vapor-phase oxidation method, Joule quench method, thermal plasma method, etc. are selected from various organic solvents such as water and alcohol. What was disperse | distributed to the dispersion medium can also be used.
When such tin oxide fine particles are used as the inorganic component, it is preferable that the tin oxide inorganic particles have an average particle size of 20 nm or less on a number basis and a 90% particle size of 30 nm or less. More preferably, the average particle size is 15 nm or less and the 90% particle size is 20 nm or less.

Here, the particle diameter is determined by a dynamic light scattering method. The average particle diameter is a central value of the particle diameter distribution, and the 90% particle diameter is a particle diameter in a range including 90% of all particles. To tell.
When the average particle diameter is larger than 20 nm or when the 90% particle diameter is larger than 30 nm, the transmittance and light scattering increase.
Further, even if the average particle size is 20 nm or less, the transmittance does not deteriorate if particles having a wide particle size distribution and a particle size larger than 30 nm are present in a ratio exceeding 10% of the total particles. Light scattering will increase.

  In addition to the tin oxide particle component and the organic component having a polymerizable functional group, an inorganic component obtained from at least one selected from a metal alkoxide represented by the following chemical formula 1 or a hydrolyzate thereof is used. Can do.

Chemical formula 1
R ¹ _a R ² _b M (OR ³ ) _c
(R ¹ and R ² are the same or different organic groups, and are an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group, a cycloalkyl group, an acyl group, or an epoxy group-containing organic group.
Specific examples include methyl group, isobutyl group, trifluoromethyl group, vinyl group, acryloyl group, methacryloyl group, phenyl group, styryl group, epoxy group, oxetanyl group, phenyl group, cyclohexyl group, norbornyl group and the like. Particularly preferred are methyl group, ethyl group, isobutyl group, phenyl group, epoxy group, oxetanyl group, acryloyl group and methacryloyl group.

R ³ is an alkyl or aryl group having 1 to 6 carbon atoms, M is Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, W, Zn, Zr At least one metal element selected from the group consisting of a and b is 0 to 2, and c = m− (a + b) where m is the valence of the metal element M.

In addition, the inorganic component modifies the surface of the inorganic component made of tin oxide to adjust the compatibility and dispersibility of the inorganic particle component made of tin oxide and the organic component having a polymerizable functional group, In order to prevent aggregation of tin oxide particles and prevent the particle diameter from becoming larger than 30 nm, the transmittance and light scattering properties are prevented from being lowered, and vinyl groups and acryloyl groups are represented as organic groups represented by R ¹ and R ^2. Using a metal alkoxide having a polymerizable organic group such as a methacryloyl group, an epoxy group, or an oxetane group, a strong covalent bond can be formed between the organic component and the inorganic component, so that compatibility and bondability are improved. Environmental stability and light scattering can be improved, and mechanical strength can also be improved.

  Specific examples of metal alkoxides or hydrolysates thereof include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Phenyltributoxysilane, vinylethoxysilane, 3-methacryloxypropyltrimethoxysilane, methacryloxypropyltris (vinyldimethylsiloxy) silane, aluminum isopropoxide, tantalum pentaethoxide, tantalum pentamethoxide, titanium isopropoxide, titanium Methacrylate triisopropoxide, germanium tetraethoxide, germanium ethyl triethoxide, hafnium normal butoxide, lanthanum , And the like propoxide or their hydrolyzates.

Furthermore, the inorganic component chosen from a metal alkoxide or its hydrolyzate can be used individually or as a mixture of multiple types. For this reason, the composition ratio of several kinds of inorganic components to be mixed can be determined in accordance with optical characteristics such as refractive index, dispersion, and transmittance required in optical design.
The addition amount of the inorganic component selected from the metal alkoxide or a hydrolyzate thereof is preferably from 1/5 to 1 in terms of the number of moles of the inorganic particle component in terms of tin (IV) oxide.

As the organic component having a polymerizable functional group, methacrylic acid, acrylic acid, methacrylic acid ester or acrylic acid ester (hereinafter referred to as (meth) acrylate containing at least one of acrylic acid ester and methacrylic acid ester) ), An epoxy compound, and a sulfur-containing organic compound.
Specific examples include methacrylic acid, acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, and nonyl. Phenyl (meth) acrylate, 2-hydroxypropyl methacrylate, 2-ethylhexyl (meth) acrylate, dimethylol tricyclodecane dimethacrylate, isobornyl methacrylate, trimethylpropane tri (meth) acrylate, nonylphenyl (meth) acrylate, cyclohexyl ( (Meth) acrylate, bisphenol A di (meth) acrylate, polyethylene glycol di (meth) acrylate, 2-methacryloyloxyethyl isocyaninate, Urethane acrylate, epoxy acrylate, bisphenol A epoxy resins, bisphenol F epoxy resin, a phenol novolak epoxy resin. The monomer may be used as it is, or may be used as an oligomer obtained by slightly polymerizing the monomer.
As the organic component having a polymerizable functional group, in addition to the above, a urethane resin, a fluororesin, a silicone resin, or the like that is compatible with other components can be used.

  In addition to the tin oxide particle component, the organic component, and the inorganic component, the optical material of the present invention includes a curing agent, a photosensitizer, a chain transfer agent, an antioxidant, and the like as other components.

Examples of the curing agent include a photopolymerization initiator and a thermal polymerization initiator. Specifically, when the organic component is (meth) acrylate, and the organic group R ¹ or R ^{2 of the} inorganic metal alkoxide is a vinyl group, acryloyl. Group or methacryloyl group, the thermal polymerization initiator may be benzoyl peroxide, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-azobisisobutyronitrile, 2,2-azobis-2,4-dimethylvalero. Nitriles, azobiscarboxamides, isopropyl hydroperoxide, tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5-dimethyl-2,5-bishexane and the like can be mentioned. As photopolymerization initiators, benzophenone, 1- Hydroxycyclohexyl phenyl ketone, 1 -(4-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethane -1-one and the like can be mentioned.

When the organic component is an epoxy resin and when the organic group R ¹ or R ^{2 of the} inorganic metal alkoxide is an epoxy group or an oxetanyl group, aromatic tertiary amines, imidazoles, Lewis Examples of polyaddition type curing agents include amine-based curing agents, modified amine-based curing agents, carboxylic acid anhydride-based curing agents, phenol-based curing agents, sulfur-containing compound-based curing agents, and isocyanate-based curing agents. Agents, polyester curing agents and the like.

  Adjustment of the refractive index and dispersion (Abbe number) of the optical material of the present invention includes the addition amount, molecular weight, crystallinity and density of the tin oxide particle component, the type and addition amount of the organic component having a polymerizable functional group, and the inorganic component. This can be carried out according to the type and amount of addition and the curing conditions.

For example, in the case of high dispersion with a high refractive index, tin oxide (IV) particles having an average particle diameter of 5 nm and a 90% particle diameter of 20 nm as a tin oxide particle component are dispersed in water as polymerizable functional groups. Optical when using methyl methacrylate as an organic component having an organic component, and 3-methacryloxypropyltrimethoxysilane as an inorganic component composed of a metal alkoxide represented by Chemical Formula 2, and using an ultraviolet curing agent containing benzophenone as another component In the material, the ratio of tin oxide fine particles and 3-methacryloxypropyltrimethoxysilane was set to 3: 1 by the mass ratio SnO ₂ : SiO ₂ when converted to the respective oxide SnO ₂ and SiO ₂ , and the entire optical material the proportion of SnO ₂ contained, in the case of changing from those not containing up to 70 wt%, the refractive index of the d-line of the optical material n Changing measurement points Abbe number νd representing the the dispersion are shown in curve A of Figure 1.

With respect to (nd, νd) = (1.492, 58) of methyl methacrylate alone, the proportion of SnO ₂ is increased and the refractive index is changed in the direction of high dispersion, and the proportion of SnO ₂ is increased to 70%. Then, high refractive index and high dispersion can be achieved up to (nd, νd) = (1.534, 48).

In the above optical material, only the inorganic component consisting of a metal alkoxide represented by the chemical formula 1 was changed to titanium tetraisopropoxide, SnO ₂ mass ratio of SnO ₂ with each oxide conversion: at TiO ₂ 1: It was set to 1. Further, the organic component having an optical material polymerizable functional group was changed to an acrylate represented by the following chemical formula 3. Changes in the measurement point of the Abbe number νd representing the refractive index nd and dispersion of the d-line of the optical material when the total amount of SnO ₂ —TiO ₂ contained in the entire optical material is not changed to 70% by mass Is shown in curve B of FIG.

Moreover, in the optical material using the sulfur-containing organic compound represented by Chemical Formula 4 as an organic component having a polymerizable functional group of the optical material and an amine curing agent as the other component, in the curing step at 60 ° C. for 1 hour, When heated at 100 ° C. for 1 hour and further at 160 ° C. for 2 hours, the refraction of the d-line of the optical material when the proportion of the inorganic component contained in the entire optical material is changed to 70% by mass in terms of SnO ₂ The change in the measurement point of the Abbe number νd representing the rate nd and the dispersion is shown in the curve C of FIG.

The ratio of SnO ₂ —TiO ₂ is increased from (nd, νd) = (1.710, 36) of the sulfur-containing organic compound alone, and the refractive index changes in the direction of high dispersion and the total amount of inorganic components is converted to SnO _2. When it is increased to 70 mass%, it can be changed to (nd, νd) = (1.819, 30).

Moreover, the inorganic component obtained from the metal alkoxide represented by Chemical Formula 1 is changed to aluminum tetraisopropoxide, and the mass ratio with tin oxide is SnO ₂ : Al ₂ 0 ₃ = 6: 4 in terms of oxide, respectively. It was.
An optical material composition using an epoxy compound represented by Chemical Formula 5 as an organic component having a polymerizable functional group and an amine curing agent as a curing agent is used at 60 ° C. for 1 hour, at 100 ° C. for 1 hour, and further 160 when heated ℃ for 2 hours, when changing the total amount of SnO ₂ and Al ₂ O ₃ contained in the entire optical material up to 70% by weight in terms of SnO _2, the dispersion and the refractive index nd at the d-line of the optical materials A change in the measurement point of the Abbe number νd is shown by a curve D in FIG.

In addition, the proportion of SnO ₂ —Al ₂ O ₃ is increased from (nd, νd) = (1.589, 32) of the epoxy resin alone, and the ratio is changed in the direction of low dispersion, and the total amount of inorganic components is converted to SnO ₂ . When the amount is increased to 70% by mass, the dispersion can be reduced to (nd, νd) = (1.584, 37).

As described above, adjusting the addition amount, molecular weight, crystallinity and density of the tin oxide particle component, the type and addition amount of the organic component having a polymerizable functional group, the type and addition amount of the inorganic component, and the curing conditions Thus, it is possible to increase the refractive index, lower dispersion, and lower the high refractive index of the optical material.
Hereinafter, the composition for optical materials produced by the present invention and the optical material obtained by polymerizing the composition will be described with reference to examples.

(Preparation of tin oxide-silica sol)
To a liquid obtained by mixing 40 g of a tin oxide particle acetic acid dispersion containing 20% by mass of tin oxide in terms of SnO ₂ and 8 g of methanol, 3.5 g of phenyltrimethoxysilane was added and stirred at 25 ° C. for 24 hours. Thus, a tin oxide-silica sol having a surface-treated tin oxide particle surface was prepared.

(Production and evaluation of optical materials)
32.2 g of the obtained tin oxide-silica sol, 45.0 g of methyl methacrylate, a photopolymerization initiator (Irgacure manufactured by Ciba Specialty Chemicals Co., Ltd.) so that the obtained inorganic component is 10% by mass in terms of SnO _2. 500) 0.05 g was added and stirred for 1 hour, and then water, methanol and by-products were removed by evaporation at 50 ° C. and cured by UV irradiation. (Nd, νd) = (1.495 57). The result is shown in FIG.

Moreover, the composition for optical materials which adjusted the mixing ratio of a tin oxide-silica sol and methyl methacrylate, and changed the compounding ratio of the inorganic component up to 70% by mass in terms of SnO ₂ was obtained in the same manner. In FIG. 2, the change of the refractive index nd and dispersion νd of the optical material is shown in FIG. 2, the horizontal axis indicates the content of the inorganic component in terms of SnO ₂ occupying the optical material in mass%, The refractive index nd and Abbe number νd of the line are shown on the vertical axis.
According to this example, an optical material having high refraction and high dispersion could be obtained.

(Preparation of tin oxide-silica sol)
Tin tetraisopropoxide 18.0g, isopropanol 72g and 0.1N hydrochloric acid 1.0g were mixed and stirred at 25 ° C for 1 hour to cause tin tetraisopropoxide to undergo hydrolysis and polycondensation reaction to produce tin oxidation. A product sol was prepared.
Next, the tin oxide sol was added to a solution obtained by mixing 10 g of 3-methacryloxypropyltrimethoxysilane and 1.0 g of water and stirring at 25 ° C. for 12 hours, and further stirring at 25 ° C. for 8 hours. Then, isopropanol and by-products were removed by an evaporation operation at 50 ° C. to obtain a tin oxide-silica sol.

(Production and evaluation of optical materials)
As an organic component having a polymerizable functional group and 12.8 g of the previously prepared tin oxide-silica sol, the proportion of the inorganic component in the optical material is 10% by mass in terms of SnO _2. A composition for optical materials was prepared by mixing 9.0 g of decane acrylate (DCP-A manufactured by Kyoeisha Chemical Co., Ltd.) and 0.02 g of a photopolymerization initiator (Irgacure 500 manufactured by Ciba Specialty Chemicals Co., Ltd.). When the obtained composition for an optical material was cured by ultraviolet irradiation, (nd, νd) = (1.537, 51). The results are shown in FIG.

Moreover, the mixing ratio of the tin oxide-silica sol and the organic component having the above-mentioned polymerizable functional group is adjusted, and the content of the tin oxide-silica sol is not included in a ratio converted to SnO ₂ from 70 mass. In the same manner, the composition for optical material changed to% is cured, and the change in the refractive index nd and dispersion νd of the obtained optical material is shown in FIG. 3, where the horizontal axis represents tin oxide converted to SnO ₂ occupying the optical material. The content of the physical component is indicated by mass%, and the refractive index nd and Abbe number νd of the d-line of the optical material obtained at each mass% are shown on the vertical axis.

(Preparation of tin oxide-titania sol)
20 g of tin oxide particle acetic acid dispersion containing 20% by mass of tin oxide in terms of SnO ₂ , 14.2 g of titanium tetraisopropoxide and 1.0 g of water mixed at 25 ° C. for 12 hours, The mixture was stirred at 25 ° C. for 8 hours to prepare a tin oxide-titania sol.

(Production and evaluation of optical materials)
4.4 g of the obtained tin oxide-titania sol, bisphenol type A epoxy compound (Epicoat 828 Japan Epoxy Resin Co., Ltd.) so that the amount of the inorganic component in the optical material is 10% by mass in terms of SnO _2. 9.0 g and tetraethylpentamine 1.0 g after mixing, water, isopropanol and by-products were removed by evaporation at 50 ° C. to produce a composition for optical materials. When heat-cured at 1 ° C. for 1 hour and further at 160 ° C. for 2 hours, an optical material of (nd, νd) = (1.599, 32) was obtained.

Moreover, the compounding ratio of tin oxide-titania sol was changed, and the compounding ratio of tin oxide-titania sol in the optical material was changed to 70% by mass by converting the compounding ratio of inorganic components into SnO ₂ . the composition was cured in the same manner, in FIG. 4 and the refractive index nd of the change in dispersion νd of the obtained optical material, shows a content of inorganic components in terms of SnO ₂ occupying the horizontal axis as an optical material in mass%, The d-line refractive index nd and Abbe number νd of the optical material obtained at each mass% are shown on the vertical axis.
As described above, an optical material having high refraction and high dispersion could be obtained.

  Since the optical material of the present invention has a high refractive index and low dispersion, the size of the optical element can be reduced, aberrations can be efficiently removed, and light scattering and environmental resistance are excellent, and it is liquid at room temperature. Therefore, since it has high workability capable of producing an optical element having a complicated shape in a short time without applying high temperature or high pressure, it can contribute to reduction in size and weight of the optical system and cost reduction.

It is a figure explaining the change of the refractive index and Abbe number of the optical material of this invention. It is a figure explaining the change of the refractive index and Abbe number of the optical material of one Example of this invention. It is a figure explaining the change of the refractive index and Abbe number of the optical material of the other Example of this invention. It is a figure explaining the change of the refractive index and Abbe number of the optical material of the other Example of this invention.

Claims (15)

An optical material composition comprising an organic component and an inorganic component, comprising an inorganic component comprising a tin oxide, an organic component having a polymerizable functional group, and a polymerization initiator. 2. The optical material according to claim 1, wherein the content of the inorganic component is 0.1 to 70% by mass in terms of the amount of tin oxide with respect to the total mass of the optical material converted to tin (IV) oxide. Composition. The composition for optical materials according to claim 1, further comprising at least one second inorganic component obtained from the metal alkoxide represented by Chemical Formula 1 or a hydrolyzate thereof.
Chemical formula 1
R ¹ _a R ² _b M (OR ³ ) _c
(R ¹ and R ² are the same or in different organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ³ is C 1-6 alkyl group or aryl group, M is selected from the group consisting of Al, Be, Cu, Ge, Hf, La, Nb, Mg, Sc, Si, Ta, Ti, V, W, Zn, Zr At least one kind of metal element, a and b are 0 to 2, and c = m− (a + b) where m is the valence of the metal element M.) The composition for optical materials according to claim 3, wherein, in the chemical formula 1, the metal element M is at least one selected from the group consisting of Al, Si, and Ti. 5. The inorganic component according to claim 1, wherein the inorganic component is obtained from a polymer obtained by polymerizing a tin alkoxide represented by the following chemical formula 2 or a hydrolyzate thereof. A composition for optical materials.
Chemical formula 2
R ⁴ _d Sn (OR ⁵ ) _4-d
(R ⁴ is an organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ⁵ is an alkyl having 1 to 6 carbon atoms. Group or aryl group, d is 0 to 1) The optical material according to any one of claims 1 to 5, wherein the inorganic particle component is tin oxide particles having an average particle size of 20 nm or less and a 90% particle size of 30 nm or less. Composition. The organic component is at least one selected from the group consisting of methacrylic acid, acrylic acid, methacrylic acid ester or acrylic acid ester, an epoxy compound, and a sulfur-containing organic compound. Item 4. The composition for optical materials according to Item. An optical material comprising an organic component and an inorganic component, wherein the composition comprises an inorganic component comprising a tin oxide, an organic component having a polymerizable functional group, and a polymerization initiator. 9. The optical material according to claim 8, wherein the content of the inorganic component is 0.1 to 70% by mass in terms of tin oxide with respect to the total mass of the optical material converted to tin (IV) oxide. 10. The optical material according to claim 8, further comprising at least one second inorganic component obtained from the metal alkoxide represented by Chemical Formula 1 or a hydrolyzate thereof.
Chemical formula 1
R ¹ _a R ² _b M (OR ³ ) _c
(R ¹ and R ² are the same or in different organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ³ is C 1-6 alkyl group or aryl group, M is selected from the group consisting of Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, W, Zn, Zr At least one kind of metal element, a and b are 0 to 2, and c = m− (a + b) where m is the valence of the metal element M.) The optical material according to claim 10, wherein in the chemical formula 1, the metal element M is at least one selected from the group consisting of Al, Si, and Ti. The optical material according to any one of claims 8 to 11, wherein the inorganic component is obtained by polymerizing a tin alkoxide represented by the following chemical formula 2 or a hydrolyzate thereof. .
Chemical formula 2
Chemical formula 2
R ⁴ _d Sn (OR ⁵ ) _4-d
(R ⁴ is an organic group, an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group, a cycloalkyl group, an acyl group or an epoxy group-containing organic group, R ⁵ is an alkyl having 1 to 6 carbon atoms. Group or aryl group, d is 0 to 1) The optical material according to any one of claims 8 to 12, wherein the inorganic component is tin oxide particles having an average particle size of 20 nm or less and a 90% particle size of 30 nm or less. 9. The organic component is at least one selected from the group consisting of methacrylic acid, acrylic acid, methacrylic acid ester or acrylic acid ester, epoxy compound, sulfur-containing organic compound, and aromatic-containing organic compound. 14. The optical material according to any one of items 13 to 13. When the refractive index nd and Abbe number νd of the d-line of the optical material are shown on the vertical axis and the horizontal axis, respectively, (nd, νd) is (1.62, 22), (1.88, 25), The composition for optical materials according to any one of claims 1 to 7, which has an optical constant in a region surrounded by (1.57, 58) and (1.47, 58). The obtained optical material.

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