JP2006022291A - Composition for optical material and optical material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical material suitable for formation of an optical element superior in optical properties including a high refractive index and a light scattering property, moldability and a surface hardness. <P>SOLUTION: This composition for the optical material comprises a tungsten oxide particle component with a WO<SB>3</SB>unit as a structural component and an organic component with a polymerizable functional group. The optical material is made of a cured product by polymerization of the composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical material composition and an optical material 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, and an observation optical system such as an image display device. In particular, the present invention relates to a composition for optical materials and an optical material excellent in high refractive index, light scattering property and surface hardness.

  In recent years, imaging modules have been used for silver salt film and digital cameras, video cameras, camera-equipped mobile phones, videophones, camera-equipped doorphones, and the like. In an optical system used for such an imaging module or the like, small size, light weight, and low cost are major issues. Therefore, in these optical systems, an optical material having a high refractive index that is easy to reduce the size of the optical element or an optical material that is simple and inexpensive to mold is frequently used.

  Examples of such an optical material include optical glass, optical thermoplastic resin, low-melting glass for obtaining a desired optical element by press molding at a high temperature, or optical element having a desired shape by polymerization with heat or light while molding. An energy curable resin that can be obtained is used.

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

  In the case of this fine particle dispersion type optical material, that is, in the case of an optical element made of an organic-inorganic composite material containing a non-uniform component such as a particle smaller than the wavelength used for the optical system, the small non-uniform component affects the optical performance. It is not considered. For this reason, a fine particle dispersion type optical material containing fine particles that are non-uniform components of about 100 nm or 30 nm has been proposed as an optical material of an optical element of a white optical system whose operating wavelength range is approximately 400 to 800 nm.

For example, Japanese Patent No. 2867388 proposes an optical resin composition that achieves a high refractive index by uniformly dispersing diamond fine powder having a particle diameter of 1 to 150 nm in a synthetic resin. Japanese Patent Laid-Open No. 2000-44811 proposes 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. Furthermore, in Japanese Patent Application Laid-Open No. 2001-74901, titanium and silicon composite metal oxide (Si _x -Ti _(1-x) O ₂ ) fine particles, TiO ₂ , Nb ₂ O ₅ , ITO, Cr ₂ O ₃ , BaTiO _{3 are used} . There has been proposed an optical material that realizes high dispersion by dispersing fine particles having a particle diameter of 2 to 100 nm such as _{3 in a} thermoplastic amorphous resin.
Japanese Patent No. 2867388 JP 2000-44811 A JP 2001-74901 A

  Optical glass has a drawback that it is difficult to process an optically effective surface into an aspherical shape with excellent aberration correction performance, or it is not suitable for mass production because processing takes time.

  In addition, in the low melting point glass, it is easy to process the optical effective surface of the optical element into an aspherical shape, and there is an advantage that it has a high refractive index and excellent environmental resistance, but on the other hand, it has a large aperture or a large uneven shape. There are drawbacks in moldability, such as difficulty in molding as an optical element, or high cost of a molding machine and a mold.

  In addition, optical thermoplastic resins and energy curable resins have the advantage of excellent moldability and mass productivity that can be molded into large-diameter or complex-shaped optical elements, but there are refractive index and dispersion ranges that can be selected as optical materials. There is a problem that it is narrow and limits the reduction in size and weight or performance of the optical system, and the surface hardness is low and is easily damaged.

  In recent years, the proposed organic-inorganic composites with fine particle dispersions have excellent moldability and transparency for forming into complex-shaped optical elements, and have the advantage of being relatively easy to mass-produce, but they are satisfactory in increasing the refractive index. The level to do is not reached. Further, an optical element made of a fine particle dispersion type organic-inorganic composite material has a problem of high light scattering.

  The light scattering property is an evaluation of the intensity of light scattering inside the optical element. For an optical element having a poor light scattering property, that is, a large scattered light intensity, even if the aberration of the optical element is zero, The image formed by the light transmitted through the optical element is blurred and cannot be said to be an excellent optical element. The light scattering property is caused by the material constituting the optical element itself, and is caused by light being scattered when the inside of the optical element is not optically uniform, that is, when the refractive index and transmittance are not uniform. ing.

  That is, when a large amount of non-uniform components smaller than the wavelength used in the optical system are present in the optical element, an optical element having a long optical path length within the optical element alone, such as a prism or a waveguide, or a microscope or a high-pixel digital camera In an optical element of an optical system in which high performance optical performance is required for the optical element itself, the intensity of scattered light becomes a problem.

  The present invention has been made in view of such problems, and is suitable for optical materials suitable for forming an optical element excellent in optical characteristics, moldability and surface hardness including a high refractive index and good light scattering properties. It aims at providing a composition and an optical material.

In order to solve the above-mentioned problems, the composition for an optical material according to claim 1 includes a tungsten oxide particle component having WO ₃ units as constituents and an organic component having a polymerizable functional group, To do.

  Invention of Claim 2 is a composition for optical materials of Claim 1, Comprising: Content of the said tungsten oxide particle component is 5 to 60% in the mass% of the oxide conversion with respect to the gross mass of an optical material. It is characterized by being.

Invention of Claim 3 is the composition for optical materials of Claim 1 or 2, Comprising: The inorganic which consists of at least 1 type chosen from the metal alkoxide represented by following Chemical formula (1), or its hydrolyzate. It further comprises an ingredient.
R ¹ _a R ² _b M (OR ³ ) _c ...... Chemical formula (1)
(In the formula, R ¹ and R ² are the same or different organic groups, 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 ³ is an alkyl group or aryl group having 1 to 6 carbon atoms, M is a group consisting of Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, Y, Zn, Zr At least one metal element selected from: a and b are 0 to 2, c is a positive integer calculated from the valence of the metal element M- (a + b))

  Invention of Claim 4 is a composition for optical materials of Claim 3, Comprising: In the said Chemical formula (1), the metal element M is at least 1 sort (s) chosen from the group which consists of Al, Si, Ti. It is characterized by.

Invention of Claim 5 is a composition for optical materials of any one of Claims 1-4, Comprising: The said tungsten oxide particle component is tungsten alkoxide and tungsten represented by following Chemical formula (2) It is characterized by comprising an acid salt, a tungsten halide, a tungsten complex compound or a hydrolyzate of these.
R ⁴ _d W (OR ⁵ ) _6-d ...... Chemical formula (2)
(In the formula, 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, and R ⁵ is a C 1 -C 1 group. 6 alkyl group or aryl group, d is 0 to 1)

  Invention of Claim 6 is a composition for optical materials of any one of Claims 1-4, Comprising: The said tungsten oxide particle component has an average particle diameter of 20 nm or less, and a 90% particle diameter is. It is characterized by being tungsten oxide particles of 30 nm or less.

  Invention of Claim 7 is a composition for optical materials of any one of Claims 1-6, Comprising: The said organic component is chosen from methacrylic acid ester or acrylic acid ester, an epoxy compound, and a sulfur-containing compound. It has at least one kind.

An optical material according to an eighth aspect of the invention is a cured product obtained by polymerizing a composition containing a tungsten oxide particle component having WO ₃ units as constituent components and an organic component having a polymerizable functional group. To do.

  Invention of Claim 9 is an optical material of Claim 8, Comprising: Content of the said tungsten oxide particle component is 5-60% in the mass% of oxide conversion with respect to the gross mass of an optical material. Features.

The invention according to claim 10 is the optical material according to claim 8 or 9, further comprising at least one inorganic component selected from a metal alkoxide represented by the following chemical formula (1) or a hydrolyzate thereof. It is characterized by including.
R ¹ _a R ² _b M (OR ³ ) _c ...... Chemical formula (1)
(In the formula, R ¹ and R ² are the same or different organic groups, 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 ³ is an alkyl group or aryl group having 1 to 6 carbon atoms, M is a group consisting of Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, Y, Zn, Zr At least one metal element selected from: a and b are 0 to 2, c is a positive integer calculated from the valence of the metal element M- (a + b))

  The invention according to claim 11 is the optical material according to claim 10, characterized in that, in the chemical formula (1), the metal element M is at least one selected from the group consisting of Al, Si and Ti. To do.

  A twelfth aspect of the invention is the optical material according to any one of the eighth to eleventh aspects, wherein the d-line refractive index nd and Abbe number νd are (nd, νd) = (1.4, 60). ), (1.6, 60), (1.9, 25), (1.9, 15), and (1.6, 20).

Invention of Claim 13 is an optical material of any one of Claims 8-12, Comprising: The said tungsten oxide particle component is a tungsten alkoxide represented by following Chemical formula (2), tungstate, It is characterized by comprising a tungsten halide, a tungsten complex compound, or a product obtained by polymerizing these hydrolysates.
R ⁴ _d W (OR ⁵ ) _6-d ...... Chemical formula (2)
(In the formula, 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, and R ⁵ is a C 1 -C 1 group. 6 alkyl group or aryl group, d is 0 to 1)

  The invention according to claim 14 is the optical material according to any one of claims 8 to 12, wherein the tungsten oxide particle component has an average particle size of 20 nm or less and a 90% particle size of 30 nm or less. It is characterized by being tungsten oxide particles.

  The invention according to claim 15 is the optical material according to any one of claims 8 to 14, wherein the organic component is at least one selected from a methacrylic acid ester or an acrylic acid ester, an epoxy compound, and a sulfur-containing compound. It is characterized by having.

  According to the composition for an optical material of the present invention, an optical material having an optical property having a high refractive index and an excellent light scattering property, and capable of molding an optical element excellent in moldability and surface hardness, and can do.

  According to the optical material of the present invention, since the refractive index is high, the size of the optical element can be reduced, the light scattering property is excellent, the surface hardness is high and the surface is not easily damaged, and the liquid is near room temperature. It has a high workability capable of producing a complex-shaped optical element in a short time without spending time, and the optical system can be reduced in size and weight and cost can be reduced.

The composition for optical materials of the present invention comprises a tungsten oxide particle component having WO ₃ units as constituent components and an organic component having a polymerizable functional group.

The optical material of the present invention is composed of a cured product obtained by polymerizing a composition containing a tungsten oxide particle component having WO ₃ units as constituent components and an organic component having a polymerizable functional group.

The tungsten oxide particle component having WO ₃ units as a constituent component is an essential component for realizing a high refractive index, and the content is 5% by mass to 60% by mass in terms of oxide with respect to the total mass of the optical material. Is preferred. When the content is less than 5% by mass, the added effect is small. When the content exceeds 60% by mass, the light scattering property is deteriorated, or the viscosity of the composition for optical materials becomes too high, and it is molded into a desired shape. Difficult problems occur. More preferably, it is 10 mass% or more and 40 mass% or less.

As the tungsten oxide particle component, a tungsten alkoxide represented by the following chemical formula (3), a tungstate, a tungsten halide, a tungsten complex compound, or a polymer obtained by polymerizing these is preferable.
R ⁴ _d W (OR ⁵ ) _6-d ...... Chemical formula (3)

In chemical formula (3), 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, and R ⁵ is an alkyl group having 1 to 6 carbon atoms or an aryl group. The group d is 0 to 1;

As the alkyl group in the organic group of R ⁴ , a methyl group, an ethyl group, an isopropyl group, a normal butyl group, an isobutyl group, and the like can be used. As the halogenated alkyl group, a trichloromethyl group, a trifluoromethyl group, a pentachloroethyl group, or the like can be used. A styryl group can be used as the aryl group. The aryl group is preferably a methyl group or a phenyl group.

As the alkyl group or aryl group for R ⁵ , a methyl group, an ethyl group, an isopropyl group, a normal butyl group, an isobutyl group, a phenyl group, and the like can be used.

  Tungsten alkoxides, tungstates, tungsten halides, tungsten complex compounds or their hydrolysates include hexaethoxy tungsten, hexa sub tungsten, hexachloro tungsten, hexabromo tungsten, sodium tungstate, ammonium tungstate. Alternatively, a hydrolyzate thereof can be used.

  In the case of using tungsten alkoxide, a lower alcohol such as ethanol, water and a catalyst as necessary are added and hydrolyzed, and then subjected to polycondensation to increase the molecular weight to a PS converted molecular weight of about 2000 to 1500,000.

  When using other than tungsten alkoxide, lower alcohol such as ethanol is added and once passed through tungsten alkoxide, it is hydrolyzed and polycondensed in the same manner as tungsten alkoxide to increase the molecular weight.

  When using tungsten oxide particle components produced from tungsten alkoxides, tungstates, tungsten halides, and tungsten complex compounds, the amount of water in the condensation polymerization reaction, the type and amount of diluting solvent such as lower alcohol, the type and amount of catalyst By appropriately adjusting the reaction temperature and the reaction time, it is possible to adjust the molecular weight related to the particle diameter and the crystallinity and density related to the optical constant (refractive index and dispersion).

  Note that tungsten oxide composed of tungsten having a valence of 6 tends to be colored blue when partly reduced and tungsten having a valence of 5 is present. In order to prevent the reduction of tungsten oxide, it is necessary to prevent acid, alkali metal ions, and alkali metal ions from being mixed as much as possible during the manufacturing process of the tungsten oxide particle component. If necessary, heating and refluxing is performed in the polymerization step to sufficiently oxidize tungsten having a valence of 5 to tungsten having a valence of 6 to prevent coloring.

  In addition, tungsten oxide crystals crushed into powdered fine particles, tungsten oxide particles produced by a known method such as a vapor phase oxidation method, a Joule quench method or a thermal plasma method can be obtained from various organic solvents such as water and alcohol. Disperse uniformly in the selected dispersion medium. This can be used as a tungsten oxide particle component. When such tungsten oxide particles are used as the tungsten oxide particle component, it is preferable that the tungsten oxide particles have an average particle size of 20 nm or less and a 90% particle size of 30 nm or less. More preferably, the average particle diameter is 15 nm or less and the 90% particle diameter is 20 nm or less.

  Here, the particle diameter is determined by a dynamic light scattering method. The average particle diameter is the central value of the particle diameter distribution, and the 90% particle diameter is a particle diameter in a range including 90% of all particles. It is. When the particle diameter of the tungsten oxide particles is larger than any particle diameter, the transmittance is lowered or the light scattering is increased. That is, even if the average particle size is 20 nm or less, if the particle size distribution is wide and particles having a particle size larger than 30 nm are present in a proportion exceeding 10% of the total particle, the transmittance does not deteriorate, Scattering intensity increases.

  Tungsten oxide particles of micron to submicron order have the property of increasing surface hardness so that they can be added to hard coat agents or surface protective agents. In nanometer-order tungsten oxide particles such as the tungsten oxide particles used in the present invention, the surface hardness is increased more significantly by increasing the particle surface area. Therefore, the surface hardness can be increased with a smaller addition amount. There is an effect that can be done.

In addition to the tungsten oxide particle component and the organic component having a polymerizable functional group, an inorganic component composed of at least one selected from a metal alkoxide represented by the following chemical formula (4) or a hydrolyzate thereof can be used. .
R ¹ _a R ² _b M (OR ³ ) _c ...... Chemical formula (4)

In the chemical formula (4), R ¹ and R ² are the same or different organic groups, and 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. It is a group. Specifically, methyl group, ethyl group, isobutyl group, trifluoromethyl group, vinyl group, acryloyl group, methacryloyl group, styryl group, epoxy group, oxetanyl group, phenyl group, cyclohexyl group, norbornyl group may be used. it can. Particularly preferred are methyl group, ethyl group, isobutyl group, acryloyl group, methacryloyl group, phenyl group, epoxy group and oxetanyl group.

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

The inorganic component modifies the particle surface of the tungsten oxide particle component, adjusts the compatibility and dispersibility of the oxidized tank stainless particle component and the organic component having a polymerizable functional group, and aggregates the tungsten oxide particles. And prevents the particle diameter from becoming larger than 30 nm, thereby preventing a decrease in transmittance and light scattering properties. In addition, when a metal alkoxide having a polymerizable organic group such as a vinyl group, an acryloyl group, a methacryloyl group, an epoxy group, or an oxetanyl group as the organic group of R ¹ and R ² is used as an inorganic component, Since strong covalent bonds are generated, compatibility and bonding properties are improved, environmental stability and light scattering properties can be further improved, and mechanical strength can also be improved.

  Metal alkoxides or their hydrolysates include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltributoxy Silane, vinylethoxysilane, 3-methacryloxypropyltrimethoxysilane, methacryloxypropyltris (vinyldimethylsiloxy) silane, aluminum isopropoxide, pentaethoxytantalum, pentamethoxytantalum, titanium isopropoxide, titanium methacrylate triisopropoxide Tetraethoxygermanium, ethyltriethoxygermanium, hafnium normal butoxide, lanthanum isop Pokishido, tetrapropoxyzirconium, tetrabutoxyzirconium, it can be used methyltrimethoxysilane zirconium, methyl tributoxyzirconium, phenyltrimethoxysilane zirconium, and phenyltriethoxysilane zirconium or hydrolysates thereof.

  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.

  In particular, Al, Ti, Si alkoxides or hydrolysates thereof are advantageous in terms of cost because they are easily available, and Al alkoxides or hydrolysates thereof are reduced in dispersion, Ti alkoxides or hydrolysates thereof. Is an effective component for increasing the refractive index and Si alkoxide or its hydrolyzate is used for reducing the refractive index.

The addition amount of the inorganic component selected from the metal alkoxide or a hydrolyzate thereof is preferably 1/10 or more and 1/5 or less with respect to the mass of the tungsten oxide particle component containing WO ₃ unit as a constituent component.

  As the organic component having a polymerizable functional group, a methacrylic acid ester or an acrylic acid ester (hereinafter referred to as “(meth) acrylate”), an epoxy compound, and a sulfur-containing compound can be used.

  Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, and nonylphenyl (meth) acrylate. , 2-hydroxypropyl methacrylate, dimethylol tricyclodecane dimethacrylate, isobornyl methacrylate, trimethylpropane tri (meth) acrylate, cyclohexyl (meth) acrylate, bisphenol A di (meth) acrylate, polyethylene glycol di (meth) Acrylate, 2-methacryloyloxyethyl isocyanate, urethane acrylate, epoxy acrylate, bisphenol A epoxy resin, bisphenol F epoxy Butter, and the like phenol novolac epoxy resin. These may be used as a monomer or may be used as an oligomer obtained by slightly polymerizing the monomer.

  The organic component having a polymerizable functional group is not particularly limited to the above as long as all components are completely compatible. For example, urethane resin, fluorine resin, silicone resin, or the like can be used.

  In the optical material composition and the optical material of the present invention, in addition to the tungsten oxide particle component, the organic component, and the inorganic component, other components include a curing agent, a photosensitizer, a chain transfer agent, an antioxidant, and the like. Can be added.

As the curing agent, a photopolymerization initiator or a thermal polymerization initiator can be selected. Specifically, when the organic component is (meth) acrylate and the organic group R ¹ or R ² of the metal alkoxide of the inorganic component is a vinyl group, acryloyl group or methacryloyl group, Benzoyl oxide, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-azobisisobutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, azobiscarboxamide, isopropyl hydroperoxide, tertiary butyl hydroperoxide , Cumyl hydroperoxide, 2,5-dimethyl-2,5-bishexane, and the like. As the photopolymerization initiator, benzophenone, 1-hydroxycyclohexyl phenyl ketone, 1- (4-isopropylphenyl)- 2-hydroxy-2-methyl Propan-1-one, 2-hydroxy-2-methyl-1-phenyl - propane-1-one, 2,2-dimethoxy-like can be used.

When the organic component is an epoxy resin and 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 acids can be used, and polyaddition type curing agents include polyamine curing agents, modified polyamine curing agents, carboxylic acid anhydride curing agents, polyphenol curing agents, sulfur-containing compound curing agents, and isocyanate-based curing agents. A curing agent, a polyester curing agent, or the like can be used.

  Increasing the refractive index of the optical material of the present invention includes the addition amount of the tungsten oxide particle component, the molecular weight, the crystallinity and density, the type and addition amount of the organic component having a polymerizable functional group, the type and addition amount of the inorganic component, and curing. It can be done depending on conditions.

For example, when importance is attached to the surface hardness, a polymer having a molecular weight of about 2000 to 1500,000 in terms of PS converted by conducting a hydrolysis reaction and a polycondensation reaction using 1-butanol as a diluent solvent as a tungsten oxide particle component. And methyl methacrylate which can have a relatively high surface hardness as an organic component having a polymerizable functional group, and tetramethoxysilane as an inorganic component composed of a metal alkoxide represented by the chemical formula (4). In the composition for an optical material in the case of using a photopolymerization initiator containing benzophenone as a mass ratio when the ratio of hexaethoxytungsten and tetramethoxysilane is converted into the respective oxides WO ₃ and SiO ₂ WO ₃ : in SiO ₂ 6: as 1, it is included in the entire optical material When changing the ratio of WO ₃ to 0-60% by mass%, the change of the measurement point of the Abbe number νd representing the dispersion and the refractive index nd at the d-line of the optical material becomes a characteristic curve A shown in FIG.

As shown in the characteristic curve A, the ratio of WO ₃ increases from (nd, νd) = (1.492, 58) of methyl methacrylate alone, and the refractive index changes in the direction of high refractive index, and the ratio of WO ₃ Can be increased to 5%, 10%, 20%, 30%, 40%, 50%, 60% by mass%, and the refractive index can be increased to (nd, νd) = (1.547, 41). .

In order to increase the refractive index, a tungsten oxide particle component in which tungsten oxide crystal particles having an average particle diameter of 21 nm and a 90% particle diameter of 30 nm are dispersed in water is used, and a polymerizable functional group is used. A fluorene compound represented by the following chemical formula (5) having a high refractive index is used as the organic component, and phenyltrimethoxysilane is used as the inorganic component composed of the metal alkoxide represented by the chemical formula (4), and benzophenone is used as the other component. In the composition for an optical material in the case of using a photopolymerization initiator containing, the mass ratio WO ₃ when the ratio of the crystal particles of tungsten oxide and phenyltrimethoxysilane is converted into the respective oxides WO ₃ and SiO _2. : The ratio of WO ₃ contained in the entire optical material is changed from 0 to 60% in mass% with 8: 1 in SiO ₂ 1, the change in the measurement point of the refractive index nd of the d-line and the Abbe number νd representing dispersion of the optical material is a characteristic curve B in FIG.

As shown in the characteristic curve B, the proportion of WO ₃ increases from (nd, νd) = (1.631, 24) of the fluorene compound alone represented by the chemical formula (5), and the refractive index increases in the direction of high refractive index. When the ratio of WO ₃ is increased to 5%, 10%, 20%, 30%, 40%, 50%, 60% by mass%, (nd, νd) = (1.777, 18) The refractive index can be increased.

In addition, in the case of a low refractive index and low dispersion, tungsten oxide particles produced by a vapor phase oxidation method having an average particle diameter of 12 nm and a 90% particle diameter of 20 nm are used as a tungsten oxide particle component. In this case, an episulfide compound represented by the chemical formula (6) is used as the organic component having a polymerizable functional group, and phenyltrimethoxysilane is used as the inorganic component composed of the metal alkoxide represented by the chemical formula (4). In the optical material using an amine-based thermal polymerization initiator as the other component, the mass ratio WO ₃ : SiO ₂ when the ratio of tungsten oxide particles and phenyltrimethoxysilane is converted into the respective oxides WO ₃ and SiO _{2. 2} is 8: 1, and the ratio of WO ₃ contained in the entire optical material is changed from 0 to 60% by mass%. Then, the change in the measurement point of the refractive index nd of the d-line and the Abbe number νd representing dispersion of the optical material is a characteristic curve C in FIG.

As shown by the characteristic curve C, the refractive index changes in the direction of the high refractive index with the ratio of WO ₃ is increased from episulfide compound single (nd, νd) = (1.710,36 ), the proportion of WO ₃ Can be increased to 5%, 10%, 20%, 30%, 40%, 50%, 60% by mass%, and the refractive index can be increased to (nd, νd) = (1.788, 25). .

When the refractive index is further increased, a tungsten oxide particle component in which tungsten oxide crystal particles having an average particle diameter of 21 nm and a 90% particle diameter of 30 nm are dispersed in water is used. An episulfide compound represented by the following chemical formula (7) having a high refractive index is used as the organic component having benzene, phenyltrimethoxysilane is used as the inorganic component comprising the metal alkoxide represented by the chemical formula (4), and amine is used as the other component In the optical material using the system thermal polymerization initiator, the ratio of tungsten oxide particles and phenyltrimethoxysilane is 8: 1 in terms of the mass ratio WO ₃ : SiO ₂ when converted to the respective oxides WO ₃ and SiO ₂ , When the proportion of WO ₃ contained in the entire optical material is changed from 0 to 60% by mass%, the d-line of the optical material The change in the measurement point of the Abbe number νd representing the refractive index nd and the dispersion is a characteristic curve D in FIG.

As shown in characteristic curve D, the refractive index changes in the direction of the high refractive index with the ratio of WO ₃ is increased from episulfide compound only (nd, νd) = (1.741,35 ), the proportion of WO ₃ Can be increased to 5%, 10%, 20%, 30%, 40%, 50%, 60% by mass%, and the refractive index can be increased to (nd, νd) = (1.872, 21). .

  As described above, by adjusting the addition amount, molecular weight, crystallinity and density of the tungsten 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, The refractive index nd and Abbe number νd of the d-line are (nd, νd) = (1.4, 60), (1.6, 60), (1.9, 25), (1.9, 15), Adjustment is possible within the range of the region surrounded by (1.6, 20). However, if the compatibility of the tungsten oxide particle component, the organic component having a polymerizable functional group, and the inorganic component is extremely poor and light scattering increases, the viscosity increases depending on the added amount of the tungsten oxide particle component and the moldability is increased. In some cases, optical performance due to curing shrinkage, for example, birefringence and refractive index uniformity, may decrease. In such a case, the amount of tungsten oxide particle component added is limited.

  From the above, more preferable ranges of the refractive index nd and Abbe number νd of the d-line are (nd, νd) = (1.4, 60), (1.6, 60), (1.8, 30), ( 1.8, 17) and (1.6, 20).

  Examples to which the present invention is applied will be specifically described below.

Example 1
In this example, a tungsten oxide particle component obtained by polycondensation by hydrolysis reaction of hexaetoxytungsten is used, and methyl methacrylate is used as an organic component having a polymerizable functional group, which is represented by the chemical formula (4). Tetramethoxysilane was used as an inorganic component composed of a metal alkoxide, and a photopolymerization initiator containing benzophenone was used as the other component.

Hexaetoxytungsten (31.1 g), 1-butanol (74 g), and water (1 g) are mixed, stirred at room temperature for 1 hour, hexaethoxytungsten is subjected to hydrolysis reaction and condensation polymerization reaction, and WO ₃ is a repeating unit. A molecular weight tungsten oxide sol solution is prepared.

  This tungsten oxide sol solution was added to a separately prepared mixed solution of 7.1 g of 3-methacryloxypropyltrimethoxysilane and 1.3 g of water and stirred at room temperature for 12 hours, and further stirred at room temperature for 8 hours. Thereafter, water, 1-butanol and by-products were removed by an evaporation operation at 60 ° C. to obtain a tungsten oxide-silica sol solution.

A photopolymerization initiator Irgacure 500 (manufactured by Nagase Sangyo Co., Ltd.) containing 20 g of this tungsten oxide-silica sol solution, 132 g of methyl methacrylate, and benzophenone so that the ratio in terms of WO _{3 in the} optical material is 5% by mass. 1 g of the product name) was mixed to obtain an optical material of this example. When this optical material was cured at 25 ° C. by ultraviolet irradiation, (nd, νd) = (1.495, 56). The results are plotted in FIG.

In addition, when the mixing ratio of the tungsten oxide-silica sol solution and methyl methacrylate is adjusted, and the optical material in which the ratio in terms of WO _{3 is} changed from 10% to 60% by mass% is similarly cured (nd , Νd) is shown in FIG.

In FIG. 2, the horizontal axis is Abbe number νd, the vertical axis is the refractive index nd of the d-line, and (nd, νd) of the optical material obtained at each mass% is indicated by “◯”. As shown in FIG. 2, the ratio of WO ₃ increases and changes in the direction of high refractive index, and the ratio of WO ₃ is 10%, 20%, 30%, 40%, 50%, 60% in mass%. Increasing the refractive index can increase the refractive index up to (nd, νd) = (1.547, 41).

  Moreover, when the pencil hardness of the surface of the obtained optical material was measured, it was 4H or more and 6H or less, and exceeded the pencil hardness of 3H on the surface of methyl methacrylate alone with no tungsten oxide particle component added.

  According to this embodiment, an optical material having high surface hardness and high refraction can be obtained.

(Example 2)
In this example, tungsten oxide particles having an average particle diameter of 21 nm and a 90% particle diameter of 30 nm dispersed in water are used as the tungsten oxide particle component, and dimethyl roll is used as the organic component having a polymerizable functional group. A photopolymerization initiator Irgacure 500 containing tricyclodecanedimethacrylate, methyltrimethoxysilane as an inorganic component composed of a metal alkoxide represented by the chemical formula (4), and benzophenone as another component was used.

Surface of tungsten oxide particles by adding 3.4 g of methyltrimethoxysilane to a solution obtained by mixing 50 g of an aqueous tungsten oxide solution containing 20% by mass of tungsten oxide in terms of WO ₃ and 20 g of methanol, followed by stirring at room temperature for 24 hours. A surface-treated tungsten oxide-silica sol solution is prepared.

After mixing 1 g of dimethylroll tricyclodecane dimethacrylate 82 g and Irgacure 500 in 30 g of tungsten oxide-silica sol solution so that the proportion in terms of WO _{3 in the} optical material is 5% by mass, When water, methanol and by-products were removed by evaporation at 60 ° C. and cured by ultraviolet irradiation, (nd, νd) = (1.557, 37). The results are plotted in FIG.

In addition, the mixing ratio of the tungsten oxide-silica sol solution and dimethylroll tricyclodecane dimethacrylate was adjusted, and the optical material in which the WO ₃ conversion ratio was changed from 10% to 60% by mass% was similarly cured. FIG. 3 shows the change of (nd, νd) at the time. In FIG. 3, the horizontal axis is the Abbe number νd, the vertical axis is the refractive index nd of the d-line, and (nd, νd) of the optical material obtained at each mass% is indicated by “O”.

As shown in FIG. 3, the refractive index changes in the direction of the high refractive index with to increase the proportion of WO ₃ is 10% the proportion of WO ₃ in mass%, 20%, 30%, 40%, 50%, If it is increased to 60%, the refractive index can be increased to (nd, νd) = (1.679, 24).

  According to this embodiment, an optical material having a high refractive index can be obtained.

Example 3
In this embodiment, a tungsten oxide particle component in which tungsten oxide crystal particles having an average particle size of 21 nm and a 90% particle size of 30 nm are dispersed in water is used, and the organic component having a polymerizable functional group is refracted. Photopolymerization using a fluorene compound represented by the above chemical formula (5) having a high rate, using phenyltrimethoxysilane as an inorganic component comprising a metal alkoxide represented by the chemical formula (4), and containing benzophenone as the other component The agent Irgacure 500 was used.

5 g of phenyltrimethoxysilane is added to a solution obtained by mixing 50 g of a tungsten oxide aqueous solution containing 20% by mass of tungsten oxide in terms of WO ₃ and 20 g of methanol, and stirred at room temperature for 24 hours to surface the surface of tungsten oxide particles. A treated tungsten oxide-silica sol solution is prepared.

80 g of fluorene compound represented by the above chemical formula (5) and 1 g of Irgacure 500 are mixed with 30 g of tungsten oxide-silica sol solution so that the ratio in terms of WO _{3 in the} optical material is 5% by mass and stirred for 1 hour. After that, water, methanol and by-products were removed by evaporation at 60 ° C. and cured by ultraviolet irradiation to obtain (nd, νd) = (1.637, 23). The results are plotted in FIG.

In addition, it is cured in the same manner for an optical material in which the mixing ratio of the tungsten oxide-silica sol solution and the fluorene compound represented by the chemical formula (5) is adjusted and the WO ₃ equivalent ratio is changed from 10% to 60% by mass%. FIG. 4 plots the change of (nd, νd) when it is applied.

As shown in FIG. 4, 10% proportion of ,, WO ₃ refractive index changes in the direction of the high refractive index with the ratio of WO ₃ is increased in mass%, 20%, 30%, 40%, 50% , Up to 60%, the refractive index can be increased to (nd, νd) = (1.777, 18).

  According to this embodiment, an optical material having a higher refractive index can be obtained.

Example 4
In this example, tungsten oxide particle components having an average particle diameter of 21 nm and a 90% particle diameter of 30 nm of tungsten oxide crystal particles dispersed in a water / alcohol mixed solvent are used and have a polymerizable functional group. Using an episulfide compound represented by the above chemical formula (7) and a bisphenol A epoxy resin as the organic component, using phenyltrimethoxysilane as the inorganic component composed of the metal alkoxide represented by the chemical formula (4), and starting thermal polymerization as the other component The agent 2,4,6-tridimethylhexylaminophenol was used.

By adding 5.5 g of 3-glycidyloxypropyltrimethoxysilane to a 50 g solution of tungsten oxide in water / methanol containing 20% by mass of tungsten oxide in terms of WO _{3 and} stirring at room temperature for 24 hours, A tungsten oxide-silica sol solution having a surface treated with tungsten oxide particles is prepared.

The tungsten oxide-silica sol solution 20 g, the episulfide compound 65 g represented by the chemical formula (7), the bisphenol A epoxy resin 7 g, 2,4,4, so that the proportion of WO ₃ equivalent in the optical material is 5% by mass After mixing 1 g of 6-tridimethylhexylaminophenol and stirring for 1 hour, water, methanol and by-products were removed by evaporation at 50 ° C. and cured by UV irradiation (nd, νd) = (1.746, 34). The results are plotted in FIG.

In addition, in the optical material in which the mixing ratio of the tungsten oxide-silica sol solution and the episulfide compound represented by the chemical formula (7) is adjusted and the ratio in terms of WO _{3 is} changed from 10% to 60% by mass, it is similarly cured. FIG. 5 shows the change of (nd, νd) at the time. In FIG. 5, the horizontal axis is the Abbe number νd, the vertical axis is the refractive index nd of the d-line, and (nd, νd) of the optical material obtained at each mass% is indicated by “O”.

As shown in FIG. 5, as the proportion of WO ₃ increases, the refractive index changes in the direction of high refractive index, and the proportion of WO ₃ is 10%, 20%, 30%, 40%, 50%, When the ratio is increased to 60%, the refractive index can be increased to (nd, γd) = (1.872, 21).

  According to this embodiment, an optical material having a higher refractive index can be obtained.

(Example 5)
In this example, as a tungsten oxide particle component, tungsten oxide particles produced by a gas phase oxidation method having an average particle size of 12 nm and a 90% particle size of 20 nm are dispersed in a water / alcohol mixed solvent, and polymerization is performed. An episulfide compound represented by the above chemical formula (6) is used as the organic component having a functional functional group, phenyltrimethoxysilane is used as the inorganic component composed of the metal alkoxide represented by the chemical formula (4), and an amine-based compound is used as the other component. A thermal polymerization initiator was used.

5 g of phenyltrimethoxysilane was added to a 50 g solution of tungsten oxide in water / methanol containing 20% by mass of tungsten oxide in terms of WO ₃ and the surface of the tungsten oxide particles was surface-treated by stirring for 24 hours at room temperature. A tungsten oxide-silica sol solution is prepared.

80 g of an episulfide compound represented by the chemical formula (6) and 0.1 g of N, N-dimethylcyclohexylamine are added to 30 g of a tungsten oxide-silica sol solution so that the ratio in terms of WO _{3 in the} optical material is 5% by mass. After mixing and stirring for 1 hour, water, methanol and by-products were removed by evaporation at 50 ° C. and cured by UV irradiation (nd, νd) = (1.713, 35). . The result is shown in FIG.

Similarly, for an optical material in which the mixing ratio of the tungsten oxide-silica sol solution and the episulfide compound represented by the chemical formula (6) is adjusted and the WO ₃ equivalent ratio is changed from 10% to 60% by mass%. FIG. 6 shows the change in (nd, νd) when cured. In FIG. 6, the Abbe number νd is plotted on the horizontal axis, the refractive index nd of the d-line is plotted on the vertical axis, and “◯” of (nd, νd) of the optical analysis material obtained at each mass%.

As shown in FIG. 6, as the proportion of WO ₃ increases, the refractive index changes in the direction of high refractive index, and the proportion of WO ₃ is 10%, 20%, 30%, 40%, 50%, Increasing it to 60% can increase the refractive index to (nd, νd) = (1.788, 25).

  According to such an embodiment, an optical material having a high refractive index and low dispersion can be obtained.

It is a graph which shows the change of the refractive index and Abbe number of the optical material of this invention. 6 is a graph showing changes in refractive index and Abbe number in Example 1; It is a graph showing the refractive index of Example 2, and the change of Abbe number. 10 is a graph showing changes in refractive index and Abbe number in Example 3. 10 is a bluff showing changes in refractive index and Abbe number in Example 4. 10 is a bluff showing changes in refractive index and Abbe number in Example 5.

Claims (15)

A composition for optical materials, comprising a tungsten oxide particle component having WO ₃ units as constituents and an organic component having a polymerizable functional group.   2. The composition for optical materials according to claim 1, wherein the content of the tungsten oxide particle component is 5 to 60% in terms of oxide% relative to the total mass of the optical material. The optical material composition according to claim 1 or 2, further comprising at least one inorganic component selected from metal alkoxides represented by the following chemical formula (1) or a hydrolyzate thereof.
R ¹ _a R ² _b M (OR ³ ) _c ...... Chemical formula (1)
(In the formula, R ¹ and R ² are the same or different organic groups, 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 ³ is an alkyl group or aryl group having 1 to 6 carbon atoms, M is a group consisting of Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, Y, Zn, Zr At least one metal element selected from: a and b are 0 to 2, c is a positive integer calculated from the valence of the metal element M- (a + b))   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. The tungsten oxide particle component is composed of a tungsten alkoxide represented by the following chemical formula (2), a tungstate, a tungsten halide, a tungsten complex compound, or a hydrolyzate thereof. Item 5. The composition for optical material according to any one of Items 1 to 4.
R ⁴ _d W (OR ⁵ ) _6-d ...... Chemical formula (2)
(In the formula, 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, and R ⁵ is a C 1 -C 1 group. 6 alkyl group or aryl group, d is 0 to 1)   5. The composition for optical materials according to claim 1, wherein the tungsten oxide particle component is tungsten oxide particles having an average particle diameter of 20 nm or less and a 90% particle diameter of 30 nm or less. object.   The composition for optical materials according to any one of claims 1 to 6, wherein the organic component has at least one selected from a methacrylic acid ester or an acrylic acid ester, an epoxy compound, and a sulfur-containing compound. An optical material, which is a cured product obtained by polymerizing a composition containing a tungsten oxide particle component having WO ₃ units as a component and an organic component having a polymerizable functional group.   9. The optical material according to claim 8, wherein the content of the tungsten oxide particle component is 5 to 60% in terms of mass% in terms of oxide with respect to the total mass of the optical material. The optical material according to claim 8 or 9, further comprising an inorganic component consisting of at least one selected from a metal alkoxide represented by the following chemical formula (1) or a hydrolyzate thereof.
R ¹ _a R ² _b M (OR ³ ) _c ...... Chemical formula (1)
(In the formula, R ¹ and R ² are the same or different organic groups, 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 ³ is an alkyl group or aryl group having 1 to 6 carbon atoms, M is a group consisting of Al, Be, Cu, Ge, Hf, La, Mg, Nb, Sc, Si, Ta, Ti, V, Y, Zn, Zr At least one metal element selected from: a and b are 0 to 2, c is a positive integer calculated from the valence of the metal element M− (a + b))   11. 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 refractive index nd and Abbe number νd of the d-line are (nd, νd) = (1.4, 60), (1.6, 60), (1.9, 25), (1.9, 15), It exists in the area | region enclosed by (1.6,20), The optical material of any one of Claims 8-11 characterized by the above-mentioned. The tungsten oxide particle component is composed of a tungsten alkoxide represented by the following chemical formula (2), a tungstate, a tungsten halide, a tungsten complex compound, or a hydrolyzate thereof. Item 13. The optical material according to any one of Items 8 to 12.
R ⁴ _d W (OR ⁵ ) _6-d ...... Chemical formula (2)
(In the formula, 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, and R ⁵ is a C 1 -C 1 group. 6 alkyl group or aryl group, d is 0 to 1)   The optical material according to any one of claims 8 to 12, wherein the tungsten oxide particle component is tungsten oxide particles having an average particle size of 20 nm or less and a 90% particle size of 30 nm or less.   The optical material according to any one of claims 8 to 14, wherein the organic component has at least one selected from a methacrylic acid ester or an acrylic acid ester, an epoxy compound, and a sulfur-containing compound.

Images