JP2008231323A - Polymerizable composition, polymer and plastic lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymerizable composition capable of manufacturing a plastic lens with a high refractive index, a polymer and a plastic lens comprising this polymer. <P>SOLUTION: The polymerizable composition comprises a polymerizable monomer having a functional group and metal oxide fine particles having a functional group. The functional group of the polymerizable monomer and the functional group of the metal oxide fine particles can react with each other. When polymerization is carried out using this polymerizable composition as the raw material, the metal oxide fine particles can be uniformly dispersed in the polymer. It is possible, therefore, to provide the plastic lens being optically uniform and having a high refractive index. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polymerizable composition, a polymer, and a plastic lens.

  Plastic lenses are lighter than glass lenses, have excellent moldability and processability, are hard to break, and have high safety. Therefore, plastic lenses have rapidly spread in the spectacle lens field and occupy most of them. In recent years, high refractive index materials such as thiourethane resins and episulfide resins have been developed in order to meet further demands for reduction in thickness and weight. For example, a method for producing an episulfide resin having a very high refractive index by polymerizing a compound having an epithio group (episulfide compound) in the presence of sulfur has been proposed (see, for example, Patent Documents 1 and 2). Alternatively, as one method for increasing the refractive index, a method of incorporating metal oxide fine particles having a high refractive index in a lens material is also known (see, for example, Patent Document 3).

JP 2001-163978 A JP 2004-197005 A Japanese Patent Laid-Open No. 7-207086

However, since the plastic lens made of an episulfide-based resin, such as Patent Document 1, contains a sulfur component at a very high ratio, the refractive index is improved, but the bonds between the main chains are very weak, Deformation is large when heat is applied, and heat resistance is low. Moreover, in patent document 2, since an inorganic sulfur component is contained, although a refractive index improves, since a crosslinking density falls, heat resistance is low. Furthermore, due to the low heat resistance, the inorganic antireflection layer used as the surface treatment layer cannot follow the thermal expansion deformation of the plastic lens base material as a base, resulting in spiders, cracks, etc. There is a fear. In addition, as in Patent Document 3, even when trying to contain metal oxide fine particles having a high refractive index in the lens material, since the lens material is an organic substance (resin), the affinity with the metal oxide fine particles is low, It was difficult to uniformly disperse the metal oxide fine particles in the lens material, and it was difficult to obtain a transparent lens.
Therefore, the present invention has been made in view of such circumstances, a polymerizable composition that is capable of producing a plastic lens having a high refractive index that is transparent and excellent in heat resistance without being limited by the lens material. It is an object of the present invention to provide a polymer and a plastic lens made of the polymer.

In order to solve the above problems, the present invention is a polymerizable composition comprising a polymerizable monomer having a functional group and metal oxide fine particles having a functional group, the functional group possessed by the polymerizable monomer, The functional group of the metal oxide fine particles can react with each other.
According to the present invention, both the polymerizable monomer and the metal oxide fine particles have functional groups capable of reacting with each other, so that they have an affinity for each other, and the metal oxide fine particles are uniformly dispersed in the polymerizable composition. Can be made. Therefore, when the polymerization is performed using this polymerizable composition as a raw material, the metal oxide fine particles can be uniformly dispersed in the polymer.
Moreover, since the metal oxide fine particles having a larger number of functional groups than the polymerizable monomer can be contained, the crosslinking density can be further increased. Therefore, it is possible to make the refractive index higher than the refractive index of the polymer itself obtained by polymerizing without dispersing such metal oxide fine particles, and it is possible to further improve the heat resistance of the polymer. Become. Therefore, when the metal oxide fine particles are used, a lens substrate that is optically transparent, has a high refractive index, and high heat resistance can be easily manufactured.

In the present invention, the functional group of the polymerizable monomer and the metal oxide fine particles is at least one functional selected from an isocyanate group, an isothiocyanate group, a thiol group, a hydroxyl group, an epoxy group, a thioepoxy group, and an episulfide group. It is preferably a group.
According to this invention, since the functional groups of the polymerizable monomer and the metal oxide fine particles are both highly reactive functional groups, the metal oxide fine particles can be more uniformly dispersed in the polymer.

In the present invention, the polymerizable monomer is preferably a monomer for producing a thiourethane resin or a thioepoxy resin.
A thiourethane resin or a thioepoxy resin is known as a lens material having a high refractive index, but by using it as a polymerizable monomer of the present invention, a lens substrate having a higher refractive index can be produced.

The present invention relates to a polymerizable composition comprising a polymerizable monomer having a functional group and metal oxide fine particles having a functional group, wherein the polymerizable monomer and the metal oxide fine particles have the same functionality. It has a group.
If the functional group of the polymerizable monomer and the functional group of the metal oxide fine particle are the same, even if the reactivity between the functional groups is low, the physical affinity is high. It can be uniformly dispersed in.

Furthermore, since the polymer lens of the present invention and the plastic lens made of this polymer are manufactured from the polymerizable composition described in any of the above, the metal oxide fine particles are uniformly dispersed therein, It can exhibit a desired refractive index and is optically uniform.
Furthermore, since the polymer network of the plastic lens made of this polymer contains an inorganic component, the coefficient of thermal expansion can be lowered as compared with a plastic lens composed entirely of organic components. Furthermore, since the surface of the metal oxide fine particles can be bonded with a larger number of functional groups than the functional groups of the polymerizable monomer, the crosslink density of the plastic lens can be increased to further improve the heat resistance. Is possible.

The polymerizable composition of the first invention of the present invention comprises a polymerizable monomer having a functional group and metal oxide fine particles having a functional group, and the functional group possessed by the polymerizable monomer and the metal oxide fine particles. It is characterized in that the functional group possessed by can react with each other. The polymerizable composition of the second invention of the present invention includes a polymerizable monomer having a functional group and metal oxide fine particles having a functional group, and the polymerizable monomer and the metal oxide fine particles are: It has the same functional group mutually.
Hereinafter, embodiments of the polymerizable composition, polymer and plastic lens of the present invention will be described in detail.
Here, the functional group of the polymerizable monomer is preferably at least one functional group selected from an isocyanate group, an isothiocyanate group, a thiol group (mercapto group), a hydroxyl group, an epoxy group, a thioepoxy group, and an episulfide group. It is mentioned in.
For example, a known compound can be used as the polymerizable monomer having an isocyanate group. Specific examples of the compound having an isocyanate group include ethylene diisocyanate, trimethylene diisocyanate, 2,4,4-trimethylhexane diisocyanate, hexamethylene diisocyanate, m-xylylene diisocyanate and the like. It is done.

Moreover, a well-known compound can be used also as a polymerizable monomer which has a mercapto group. For example, 1,2-ethanedithiol, 1,6-hexanedithiol, aliphatic polythiol such as 1,1-cyclohexanedithiol, 1,2-dimercaptobenzene, 1,2,3-tris (mercaptomethyl) benzene, etc. Aromatic polythiols are mentioned.
In addition, in order to increase the refractive index of a plastic lens, a polythiol containing a sulfur atom can be more preferably used in addition to a mercapto group. Specific examples include 1,2-bis (mercaptomethylthio) benzene, 1,2,3-tris (mercaptoethylthio) benzene, 1,2-bis ((2-mercaptoethyl) thio) -3-mercaptopropane, and the like. Is mentioned.

  As a specific example of the polymerizable monomer having an episulfide group, a known compound having an episulfide group can be used without any limitation. For example, an episulfide compound obtained by replacing part or all of the oxygen of an epoxy group of an existing epoxy compound with sulfur can be used. As the polymerizable monomer having an episulfide group, those described in paragraphs [0038] and [0039] of JP-A No. 2004-345123 can be preferably used.

  In particular, in order to increase the refractive index of plastic lenses, the following polymerizable monomers containing sulfur atoms can be preferably used. Specific examples include 1,2-bis (β-epithiopropylthio) ethane, bis- (β-epithiopropyl) sulfide, 1,4-bis (β-epithiopropylthiomethyl) benzene, 2,5 -Bis (β-epithiopropylthiomethyl) -1,4-dithiane, bis- (β-epithiopropyl) disulfide and the like.

Next, metal oxide fine particles having a functional group will be described.
As the metal oxide fine particles serving as a base, a metal oxide having a high refractive index can be preferably used.
As metal oxide fine particles having a high refractive index, oxides of one or more metals selected from Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In, and Ti (these And / or colorless and transparent metal oxide fine particles comprising a composite oxide containing two or more metals are suitably used. Among these, metal oxide fine particles containing titanium oxide are preferable from the viewpoints of refractive index, transparency, dispersion stability, and the like.

  However, when metal oxide fine particles containing titanium oxide are used as a metal oxide dispersed in a plastic lens substrate, there are the following problems. Titanium oxide is active when it receives light (ultraviolet light) energy, and has a property of decomposing organic matter by a strong oxidative degradation power (hereinafter referred to as photoactivity). As a result, when titanium oxide is contained as a constituent component of the plastic lens, there is a possibility that the material resin constituting the lens is decomposed by photoactivity, and the durability quality is deteriorated.

  Therefore, it is preferable to use a metal oxide containing titanium oxide having a rutile crystal structure. That is, by using metal oxide fine particles containing titanium oxide having a rutile-type crystal structure, various problems caused by the photoactivity of titanium oxide can be improved. By changing the crystal structure of the metal oxide containing titanium oxide to the rutile type instead of the anatase type, the weather resistance and light resistance of the lens are further improved, and the refractive index of the rutile type crystal is higher than that of the anatase type crystal. Therefore, metal oxide fine particles having a relatively high refractive index can be obtained.

Titanium oxide having a rutile-type crystal structure is active when anatase-type titanium oxide receives light (ultraviolet light) energy, and has the property of decomposing organic substances by strong oxidative degradation power. Low photoactivity. This is because, when irradiated with light (ultraviolet rays), electrons in the valence band of titanium oxide are excited to form OH free radicals and HO ₂ free radicals, which decompose organic substances by this strong oxidizing power. This is because rutile type titanium oxide is more stable in terms of thermal energy, and the amount of free radicals produced is extremely small. Therefore, since a lens base material containing titanium oxide having a rutile crystal structure is superior in weather resistance and light resistance, a plastic lens excellent in weather resistance and light resistance can be obtained as a result.

Although several methods for obtaining titanium oxide having a rutile-type crystal structure are conceivable, it is preferable to use a composite oxide with tin oxide and a composite oxide with addition of silicon oxide. If you make a composite oxide of tin oxide, when the amount of titanium oxide and tin oxide contained in the metal oxide fine particles, which converts the titanium oxide TiO _2, by converting the tin oxide SnO _2, TiO ₂ It is desirable that the mass ratio of / SnO ₂ is in the range of 1/3 to 20/1, preferably 1.5 / 1 to 13/1.

When the amount of SnO ₂ is made smaller than the above mass ratio range, the crystal structure shifts from the rutile type to the anatase type, resulting in a mixed crystal containing the rutile type crystal and the anatase type crystal, or anatase. It becomes a type crystal. Further, when the amount of SnO ₂ is made larger than the range of the above mass ratio, a rutile type crystal structure intermediate between the rutile type crystal of titanium oxide and the rutile type crystal of tin oxide is obtained, so-called rutile type of titanium oxide. A crystal structure different from that of the crystal is exhibited, and the refractive index of the obtained metal oxide fine particles is also lowered.

In addition, when a composite oxide with tin oxide and a composite oxide with silicon oxide added are added, the amount of titanium oxide, tin oxide, and silicon oxide contained in the metal oxide fine particles is such that titanium oxide is TiO _2. When the tin oxide is converted to SnO ₂ and the silicon oxide is converted to SiO ₂ , the mass ratio of TiO ₂ / SnO ₂ is 1/3 to 20/1, preferably 1.5 / 1 to 13 /. 1 and the mass ratio of (TiO ₂ + SnO ₂ ) / SiO ₂ is 50/45 to 99/1, preferably 70/30 to 98/2.

The content of SnO ₂ is the same as that when a composite oxide with tin oxide is added, but by adding silicon oxide to this, the stability and dispersibility of the resulting metal oxide fine particles are improved. be able to. Here, when the amount of SiO ₂ is made smaller than the range of the mass ratio, stability and dispersibility are lowered. Further, when the amount of SiO ₂ is increased from the above mass ratio range, the stability and dispersibility are further improved, but the refractive index of the obtained metal oxide fine particles is lowered, which is not preferable. However, free radicals are also generated in this rutile titanium oxide. The same applies to the case where metal oxide fine particles containing two or more composite oxides containing titanium oxide are used as the metal oxide fine particles containing titanium oxide.

  The average particle diameter of the metal oxide fine particles made of titanium oxide or the like is in the range of 1 to 200 nm, preferably 5 to 30 nm. When the average particle size is less than 1 nm, the particles may be bridged and not uniformly dispersed when preparing the polymerizable composition. On the other hand, if the average particle diameter exceeds 200 nm, the lens becomes white when it becomes a lens and becomes unsuitable for use as an optical component.

  The metal oxide fine particles containing titanium oxide having a rutile crystal structure may be used alone or in combination with other metal oxide fine particles. Other metal oxide fine particles include one or more metal oxides selected from Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, and In (a mixture thereof) And / or metal oxide fine particles composed of a composite oxide containing two or more metals.

Here, the metal oxide fine particle of the present invention is a functional group capable of reacting with the functional group of the polymerizable monomer described above in order to increase the dispersion stability in the polymerizable composition and improve the crosslinking density, or It must have the same functional group as the functional group of the polymerizable monomer.
For example, by treating the surface of the metal oxide fine particle with an organosilicon compound, a hydroxyl group (—OH group) can be bonded to the surface. Examples of the organosilicon compound used in this case include monofunctional silane, bifunctional silane, trifunctional silane, and tetrafunctional silane.
Similarly, by treating the surface of the metal oxide fine particle with a mercapto compound, the surface can be provided with a thiol group (—SH group). A known compound can be used as the mercapto compound used in this case. For example, 1,2-ethanedithiol, 1,6-hexanedithiol, aliphatic polythiol such as 1,1-cyclohexanedithiol, 1,2-dimercaptobenzene, 1,2,3-tris (mercaptomethyl) benzene, etc. Aromatic polythiols are mentioned.
Further, by treating the surface of the metal oxide fine particles with an isocyanate compound, an isocyanate group (—NCO group) can be provided on the surface. A known compound can be used as the isocyanate compound used in this case. Examples thereof include ethylene diisocyanate, trimethylene diisocyanate, 2,4,4-trimethylhexane diisocyanate, hexamethylene diisocyanate, m-xylylene diisocyanate and the like.

  The type and blending amount of the metal oxide fine particles are determined by the refractive index of the target lens, etc., but the blending amount is 1 to 5% by mass, particularly 5 to 30% in solid content in the polymer composition. It is desirable to be in the range of mass%. If the blending amount is too small, the refractive index may not be sufficiently controlled. On the other hand, if the amount is too large, the physical properties (specific gravity, impact resistance, etc.) of the lens may be adversely affected.

The polymerization method of the polymerizable composition in the present invention is not particularly limited, and a polymerization method generally used for obtaining a polymer for a lens can be applied.
For example, when producing a thiourethane resin as a polymer, a monomer having an isocyanate group or an isothiocyanate group, a monomer having a mercapto group, and metal oxide fine particles having at least one of these functional groups Mix. And the thiourethane resin which has the target refractive index can be manufactured by adding and mixing the curing catalyst for urethane resins, and performing polymerization hardening by heating. Specific examples of the curing catalyst include amine compounds such as ethylamine, ethylenediamine, triethylamine, and tributylamine, dibutyltin dichloride, dimethyltin dichloride, and the like.

  In the case of an episulfide resin, after mixing a monomer having an episulfide group and a metal oxide fine particle having a functional group capable of reacting with the episulfide group, an epoxy resin curing catalyst is added, mixed, and polymerized by heating. It can be manufactured by curing. Other monomers capable of reacting (copolymerizing) with episulfide groups may coexist. In that case, metal oxide particles having a functional group capable of reacting with a functional group of the other monomer may be used. Or you may use the metal oxide microparticles | fine-particles which have the same functional group (for example, episulfide group) as the functional group which the above-mentioned monomer has.

The curing catalyst for epoxy resin can be used without particular limitation. Specific examples include dimethylbenzylamine, dimethylcyclohexylamine, diethylethanolamine, dibutylethanolamine, tertiary amines such as tridimethylaminomethylphenol, imidazoles such as ethylmethylimidazole, and the like.
Examples of the functional group capable of reacting with an episulfide group include a hydroxyl group, a mercapto group, a primary or secondary amino group, and a carboxyl group.

  In addition, as a monomer capable of reacting (copolymerizing) with a monomer having an episulfide group, specific examples of the monomer having a hydroxyl group include alcohols such as isopropyl alcohol and n-hexyl alcohol, ethylene glycol, 1,6-hexanediol, Examples include polyhydric alcohols such as pentaerythritol dimethacrylate and pentaerythritol diacrylate. Specific examples of the compound having a mercapto group include thiophenol, ethylthioglycolate, bis (2-mercaptoethyl) sulfide, 2,5-dimercaptomethyl-1,4-dithiane, and the like.

The lens base material made of the above-mentioned polymer is optically transparent and has a desired refractive index because the metal oxide fine particles having a predetermined refractive index are uniformly dispersed in the polymer. Yes.
In addition, a primer layer, a hard coat layer, an antireflection layer, and an antifouling layer are formed on the lens base material as necessary to obtain a desired plastic lens. Hereinafter, each of these layers will be briefly described.

(Primer layer)
The primer layer is formed on the outermost surface of the lens substrate and is present at the interface between both the lens substrate and the hard coat layer described later, and has the property of exhibiting adhesion to both the lens substrate and the hard coat layer. It plays a role of improving the durability of the entire surface treatment film. Furthermore, it also has the property as an external shock absorbing layer and has the property of improving impact resistance.
Such a primer layer is preferably formed using a coating composition containing an organic resin polymer having polarity and metal oxide fine particles containing titanium oxide.

  Moreover, the film thickness of a primer layer is 0.01-50 micrometers, Especially the range of 0.1-30 micrometers is preferable. If the primer layer is too thin, basic performance such as water resistance and impact resistance cannot be realized. Conversely, if the primer layer is too thick, the smoothness of the surface may be impaired, or appearance defects such as optical distortion, white turbidity, and cloudiness may occur. There is a case. In addition, in order to avoid generation | occurrence | production of an interference fringe, it is preferable to match | combine the refractive index of a primer layer with the refractive index of a lens base material.

(Hard coat layer)
The hard coat layer is formed on the primer layer formed on the lens substrate surface. The hard coat layer may be formed using a coating composition containing metal oxide fine particles containing titanium oxide having a rutile-type crystal structure and a compound (component B) represented by the following formula (1). preferable. R ¹ R ² _n SiX ¹ _3-n (1)
(In the formula, R ¹ is an organic group having a polymerizable reactive group, R ² is a hydrocarbon group having 1 to 6 carbon atoms, X ¹ is a hydrolytic group, and n is 0 or 1. is there.)

Examples of the metal oxide fine particles include metal oxide fine particles having an average particle diameter of 1 to 200 nm including a composite oxide having a rutile type crystal structure composed of titanium oxide and tin oxide, or titanium oxide, tin oxide and silicon oxide. Can be mentioned.
By using metal oxide fine particles containing titanium oxide having a rutile-type crystal structure, weather resistance and light resistance are further improved, and the refractive index is higher for rutile-type crystals than for anatase-type crystals. Therefore, metal oxide fine particles (composite fine particles) having a relatively high refractive index can be obtained.

  In addition, it is preferable that the film thickness of a hard-coat layer is 0.05-30 micrometers. If the film thickness is less than 0.05 μm, the basic performance cannot be realized. On the other hand, if the film thickness exceeds 30 μm, the smoothness of the surface may be impaired or optical distortion may occur. The refractive index of the hard coat layer is preferably matched to the refractive indexes of the lens substrate and the primer layer in order to avoid generation of interference fringes.

(Antireflection layer)
The antireflection layer is formed on the hard coat layer. The formed antireflection layer has a refractive index lower by 0.10 or more than the refractive index of the hard coat layer, and is composed of a single layer or multiple layers of an inorganic thin layer or an organic thin layer having a layer thickness of 50 nm to 150 nm. Is done. The material of the inorganic thin _{layer, SiO 2, SiO, ZrO 2} , TiO 2, TiO, Ti 2 O 3, Ti 2 O 5, Al 2 O 3, Ta 2 O 5, CeO 2, MgO, Y 2 O 3 , SnO ₂ , MgF ₂ , WO _{3 and the} like, and these can be used alone or in combination of two or more. In the case of a plastic lens, SiO ₂ , ZrO ₂ , TiO ₂ , and Ta ₂ O ₅ that can be vacuum-deposited at a low temperature are preferable. Also, if a multi layer structure, the outermost layer is preferably a SiO _2.

As a method for forming the inorganic thin layer, for example, a vacuum deposition method, an ion plating method, a sputtering method, a CVD method, a method of depositing by a chemical reaction in a saturated solution, or the like can be employed. In the vacuum vapor deposition method, an ion beam assist method in which an ion beam is simultaneously irradiated during vapor deposition may be used.
The material of the organic thin layer is selected in consideration of the refractive index of the plastic lens and the hard coat layer, and it can be formed by a coating method excellent in mass productivity such as spin coating method and dip coating method in addition to the vacuum evaporation method. it can.

(Anti-fouling layer)
As described above, the plastic lens in which the primer layer, the hard coat layer and the antireflection layer are formed on the lens substrate is further provided on the antireflection layer for the purpose of improving the water and oil repellency of the plastic lens surface. It is preferable to form an antifouling layer made of an organosilicon compound containing fluorine. As the organosilicon compound containing fluorine, for example, fluorine-containing silane compound compounds described in JP-A-2005-301208 and JP-A-2006-126782 can be suitably used.

Next, examples and comparative examples based on the embodiment of the present invention will be described. Specifically, plastic lenses were produced by the following method, and the dispersibility, refractive index, and linear expansion coefficient of the metal oxide fine particles were evaluated.
[Example 1]
40 parts by mass of m-xylene diisocyanate, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl as a raw material monomer for lens production 40 parts by mass of a mixed monomer composed of -1,11-dimercapto-3,6,9-trithiaundecane and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, UV After adding 1.2 parts by mass of a trade name “SEESORB701” (manufactured by Sipro Kasei Kogyo) as an absorbent and 0.1 parts by weight of a trade name “Zelec UN” (manufactured by Stepan) as an internal mold release agent, mixing, In a raw material composition which is sufficiently stirred and completely dispersed, a metal oxide fine particle mainly composed of titanium oxide having an isocyanate group (—NCO) on the surface thereof is used. Was added at a concentration of 20 parts by weight of the child, it was possible to uniformly disperse.
Next, 0.01 parts by mass of dibutyltin dichloride was added as a catalyst, and the mixture was sufficiently stirred at room temperature to obtain a uniform solution. Subsequently, this polymerizable composition was deaerated for 30 minutes while reducing the pressure to 5 mmHg and stirring. Then, this composition was poured into a mold held by an adhesive tape using two glass molds, and the temperature was raised from 30 ° C. to 120 ° C. over 24 hours in an atmospheric polymerization furnace to polymerize and cure. It was. Thereafter, the lens was removed from the mold and heated at 120 ° C. for 1 hour for annealing treatment to obtain lens A.

(Evaluation of refractive index)
The refractive index of the lens was measured at 20 ° C. by e-line (wavelength 546 nm) using an Abbe refractometer manufactured by Atago. In order to measure the refractive index, a 2 mm-thick flat plate was manufactured and used for measurement. Specifically, in two glass flat plates whose outer peripheral portions are sealed with a tape so that the thickness is 2 mm, a monomer that is a lens raw material, metal oxide fine particles, and the like are injected, and under the above polymerization conditions, A flat plate was produced by polymerization curing, mold release and annealing.
The refractive index of the lens A measured by this method was 1.736.

(Evaluation of linear expansion coefficient)
The linear expansion coefficient of the lens was measured using a thermomechanical analyzer (manufactured by Shimadzu Corp .: TMA60) under the conditions of a load of 5 g, a needle probe (2 mmφ), and a temperature rising speed of 10 ° C./min. In order to measure the linear expansion coefficient, a 2 mm-thick flat plate similar to the measurement of the refractive index was manufactured and used for the measurement.
The linear expansion coefficient of the lens A measured by this method was 4.4 × 10 ⁻⁵ / ° C.

[Example 2]
A lens B was obtained in the same manner as in Example 1 except that metal oxide fine particles mainly composed of titanium oxide having a thiol group (mercapto group -SH) on the surface were added at a concentration of 20 parts by mass. In the preparation of the polymerizable composition, the metal oxide fine particles could be uniformly dispersed.
The refractive index of the lens B was 1.736. The linear expansion coefficient of the lens B was 4.4 × 10 ⁻⁵ / ° C.

Example 3
As raw material monomers for lens production, 72 parts by mass of bis (2,3-epithiopropyl) disulfide, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4, A mixed monomer comprising 7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane 8 parts by mass, 1.0 part by mass of the trade name “SEESORB701” (manufactured by Sipro Kasei Kogyo Co., Ltd.) as an ultraviolet absorber was added, mixed, and then sufficiently stirred to completely disperse the surface of the raw material composition. When metal oxide fine particles mainly composed of titanium oxide having a thioepoxy group were added at a concentration of 20 parts by mass, uniform dispersion was possible.
Next, 0.1 part by mass of N, N-dimethylcyclohexylamine was added as a catalyst, and the mixture was sufficiently stirred at room temperature to obtain a uniform liquid. Subsequently, this polymerizable composition was deaerated for 30 minutes while reducing the pressure to 5 mmHg and stirring. Then, this composition was poured into a mold held by an adhesive tape using two glass molds, and the temperature was raised from 30 ° C. to 120 ° C. over 24 hours in an atmospheric polymerization furnace to polymerize and cure. It was. Thereafter, the lens was removed from the mold and heated at 130 ° C. for 2 hours for annealing treatment to obtain lens C.
The refractive index of the lens C was 1.792. Further, the linear expansion coefficient of the lens C was 6.4 × 10 ⁻⁵ / ° C.

Example 4
A lens D was obtained in the same manner as in Example 3 except that metal oxide fine particles mainly composed of titanium oxide having a thiol group (mercapto group) on the surface were added at a concentration of 20 parts by mass. In the preparation of the polymerizable composition, the metal oxide fine particles could be uniformly dispersed.
The refractive index of the lens D was 1.792. The linear expansion coefficient of the lens D was 6.4 × 10 ⁻⁵ / ° C.

[Comparative Example 1]
An attempt was made to carry out polymerization in the same manner as in Example 1 except that the metal oxide fine particles having no functional group were added at a concentration of 20 parts by mass, but the metal oxide fine particles were uniformly in the raw material composition. Since it did not disperse and settled, it gave up polymerization hardening.

[Comparative Example 2]
50 parts by mass of m-xylene diisocyanate, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl as a raw material monomer for lens production 50 parts by mass of a mixed monomer composed of -1,11-dimercapto-3,6,9-trithiaundecane and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, A lens E was obtained in the same manner as in Example 1 except that the metal oxide fine particles were not added.
The obtained lens E had a low refractive index of 1.667 and the lens E had a high linear expansion coefficient of 8.0 × 10 ⁻⁵ / ° C.

  The polymerizable composition of the present invention can be suitably used for producing a plastic lens having a high refractive index.

Claims (6)

A polymerizable composition comprising a polymerizable monomer having a functional group and metal oxide fine particles having a functional group,
A polymerizable composition, wherein a functional group of the polymerizable monomer and a functional group of the metal oxide fine particles can react with each other. The polymerizable composition of claim 1, wherein
The functional group that the polymerizable monomer and the metal oxide fine particles have,
A polymerizable composition comprising at least one functional group selected from an isocyanate group, an isothiocyanate group, a thiol group, a hydroxyl group, an epoxy group, a thioepoxy group, and an episulfide group. The polymerizable composition according to claim 1 or 2,
The polymerizable composition is a monomer for producing a thiourethane resin or a thioepoxy resin. A polymerizable composition comprising a polymerizable monomer having a functional group and metal oxide fine particles having a functional group,
The polymerizable composition, wherein the polymerizable monomer and the metal oxide fine particles have the same functional group.   A polymer produced from the polymerizable composition according to any one of claims 1 to 4.   A plastic lens formed from the polymer according to claim 5.