JP2001172288A - Organogermanium compound and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new compound capable of giving optical materials high in both refractive index and Abbe number and excellent in heat resistance, weatherability and transparency, and to provide a method for producing the above new compound. SOLUTION: This new compound is a germanium compound of general formula (I): Ge(SCH=CH2)x(NCO)4-x (x is an integer of 1-4). The other objective method for producing the germanium compound comprises the following process: sulfur as a simple substance is reacted with a vinylmagnesium halide to form the corresponding vinylthiomagnesium halide, which is then reacted with a tetrahalogenogermanium to obtain tetra(vinylthio)germanium of general formula (I-a): Ge(SCH=CH2)4, a version of the above germanium compound. An alternative method comprises the following process: tetra(vinylthio)germanium is reacted with tetraisocyanatogermanium to obtain a second version of the above germanium compound of general formula (I-b): Ge(SCH=CH2)y(NCO)4-y (y is an integer of 1-3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel organogermanium compound and a method for producing the same. More specifically, the present invention relates to an organic germanium compound useful as a raw material for an optical material having a high refractive index and a high Abbe number, and a method for efficiently producing the same.

[0002]

2. Description of the Related Art Plastics have been used for various optical applications such as lenses in recent years because they are lighter in weight, harder to break and easier to dye than glass. As the optical plastic material, poly (diethylene glycol bisallyl carbonate) (CR-39) and poly (methyl methacrylate) are generally used. However,
Since these plastics have a refractive index of 1.50 or less, when they are used, for example, as lens materials, the stronger the power, the thicker the lens, and the superiority of plastics, which is advantageous in light weight, is impaired. In particular, a concave lens having high strength is not preferable because the periphery of the lens becomes thick and birefringence and chromatic aberration occur. Further, in eyeglass applications, thick lenses tend to degrade aesthetics. In order to obtain a thin lens, it is effective to increase the refractive index of the material, but in general, the Abbe number of glass and plastic decreases with an increase in the refractive index, and as a result, their chromatic aberrations are reduced. To increase. Therefore, a plastic material having both a high refractive index and an Abbe number is desired.

As plastic materials having such performance, for example, (1) polyurethane obtained by polyaddition of a polyol having bromine in a molecule and polyisocyanate (JP-A-58-164615), (2)
Polythiourethanes obtained by polyaddition of polythiol and polyisocyanate (JP-B-4-58489, JP-B-5-148340, etc.) have been proposed. In particular, regarding the polythiol used as the raw material of the polythiourethane of (2), a branched-chain polythiol having an increased sulfur atom content (Japanese Patent Application Laid-Open Nos. 2-270859 and 5-148340), Polythiols having a dithiane structure introduced to increase the content (Japanese Patent Publication No. 6-5323, Japanese Patent Application Laid-Open No. 7-11839)
No. 0) has been proposed. Furthermore, (3) a polymer of an alkyl sulfide having an episulfide as a polymerization functional group has been proposed (JP-A-9-72580, JP-A-9-110979).

However, although the polyurethane of the above (1) has a slightly improved refractive index, it has disadvantages such as low Abbe number, poor light resistance, high specific gravity, and impaired lightness. are doing. Among the polythiourethanes of (2), the polythiourethane obtained by using a polythiol having a high sulfur content as a raw material polythiol has a refractive index increased to, for example, about 1.60 to 1.68. However, there is a problem that the Abbe number is lower than that of an optical inorganic glass having the same refractive index, and the Abbe number must be further increased. On the other hand, the alkyl sulfide polymer (3) has an Abbe number of 36 as an example, and the refractive index is increased to 1.70. The lens obtained by using this polymer is significantly thinner and lighter. However, there has been a demand for a plastic lens material having a higher refractive index and Abbe number at the same time.

[0005]

Under such circumstances, the present invention can provide an optical material having both a high refractive index and a high Abbe number and having excellent heat resistance, weather resistance, transparency and the like. It is an object of the present invention to provide a novel compound and a method for efficiently producing the same.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, at least one vinylthio group is bonded to a germanium atom, and optionally, an isocyanate group is bonded. It has been found that the organogermanium compound is a novel compound and can be adapted to the above-mentioned object, and that it can be efficiently obtained by a specific method, and completes the present invention based on this finding. Reached.

That is, the present invention provides: (1) General formula (I) Ge (SCH = CH ₂ ) _x (NCO) _4-x (I) (where x represents an integer of 1 to 4) And (2) reacting sulfur alone with vinylmagnesium halide to obtain vinylthiomagnesium halide, and then reacting with tetrahalogenogermanium to obtain a compound represented by the formula (I-a). _{) Ge (SCH = CH 2)} 4 ... ( manufacturing method tetra (vinylthio) germanium represented by I-a), and (3) tetra (vinylthio) and wherein the reaction of germanium and tetra-isocyanatomethyl germanium The organic germanium represented by the general formula (I-b) Ge (SCH = CH ₂ ) _y (NCO) _4-y (I-b) (where y represents an integer of 1 to 3) Conversion A method for producing a compound.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The organogermanium compound of the present invention has a general formula (I) Ge (SCH = CH ₂ ) _x (NCO) _4-x (I) wherein x is an integer of 1 to 4. As is clear from the above general formula (I), a germanium atom has 1 to 4 vinylthio groups and 0 to 3
Characterized in that it is bonded to two isocyanate groups.

[0009] The refractive index of a substance increases with an increase in the refractive index (atomic refraction) of the constituent elements and a decrease in the molecular volume.
Compared with a vinyl sulfide compound or an isocyanate compound whose skeleton is composed of carbon (atomic refraction = 2.42), the refractive index of the organic germanium compound of the present invention into which germanium (atomic refraction = 4.1) is introduced is significantly increased. ,
The polymer obtained using this compound as a raw material also increases.

[0010] The germanium compound of the present invention is tetrafunctional, and the functional groups are composed of as few elements as possible. Therefore, the refractive index of the polymer obtained using the compound is as follows:
It increases from a decrease in molecular volume caused by an increase in crosslink density. Therefore, in order to maintain a high crosslinking density and increase the refractive index without lowering the Abbe number, a vinylthio group or an isocyanate group must always be directly bonded to a germanium atom. The number of these substituents is 1 to 4 for the former (x = 1 to 4 in the general formula (I)), and 0 to 3 for the latter ((4-x) =
By changing the content in the range of 0 to 3), the optical properties, thermal properties, and mechanical properties of the polymer obtained using the germanium-containing compound of the present invention can be adjusted.

Specific examples of the germanium compound represented by the general formula (I) include tetra (vinylthio) germanium (x = 4), tri (vinylthio) isocyanatogermanium (x = 3), and di (vinylthio) diamine. Examples include isocyanatogermanium (x = 2) and vinylthiotriisocyanatogermanium (x = 1). The germanium compound represented by the general formula (I) can be efficiently produced by the method of the present invention described below.

The method of the present invention comprises the following reaction formula:

[0013]

Embedded image

(Wherein X ¹ and X ² are each a halogen atom, and y is an integer of 1 to 3). First, a vinyl magnesium halide of the general formula (II) is reacted with sulfur alone to obtain The vinylthiomagnesium halide of formula (III) is formed. Next, the vinylthiomagnesium halide is reacted with the tetrahalogenogermanium of the formula (IV) to obtain one of the organogermanium compounds of the present invention.
One in which the formula (I-a) Ge (SCH = CH 2) 4 ... a tetra (vinylthio) germanium represented by (I-a) is prepared.

Next, by reacting the tetra (vinylthio) germanium (Ia) with the tetraisocyanatogermanium of the formula (V), another organogermanium compound of the present invention represented by the general formula (Ib) A compound represented by Ge (SCH = CH ₂ ) _y (NCO) _4-y (Ib) (where y represents an integer of 1 to 3) is obtained. In this reaction, tetra (vinylthio)
By making the molar ratio of tetraisocyanatogermanium to germanium substantially 0.3, 1.2, and 2, y in the general formula (Ib) becomes 1, 2
And 3 are obtained as the main products.

In this reaction, the vinyl compound of the general formula (II)
X in rumagnesium halide ¹As a chlorine source
And bromine atoms, but from the viewpoint of reactivity etc.
A bromine atom is preferred. Also, tetrahalogeno of the formula (IV)
X in germanium^TwoAs a chlorine atom or bromine source
Children are preferred.

Next, each of the above reactions will be specifically described. First, a vinyl magnesium halide of the general formula (II) and sulfur powder are added in a suitable solvent such as an ether solvent such as tetrahydrofuran in a substantially equimolar ratio, and the mixture is reacted at a temperature of about 10 to 40 ° C. To form a vinylthiomagnesium halide of the general formula (III). Then, without isolating the product, to this reaction mixture is added a tetrahalogenogermanium of formula (IV)
The reaction is performed at a temperature of about 10 to 50 ° C. In this reaction, it is preferable to use vinylthiomagnesium halide (III) in excess of the stoichiometric amount with respect to tetrahalogenogermanium (IV).

After completion of the reaction, the reaction product is subjected to extraction treatment using a suitable solvent according to a conventionally known method, and then the solvent is distilled off from the extract, and the residue is distilled under reduced pressure. Which is one of the germanium compounds of the formula (I)
-A) tetra (vinylthio) germanium can be obtained. The above reaction is consistent with nitrogen, argon,
It is preferable to carry out in an atmosphere of an inert gas such as helium.

Next, the thus obtained formula (I-
a) Tetra (vinylthio) germanium of formula (V) and tetraisocyanatogermanium of formula (V) are mixed at a predetermined ratio, and the mixture is heated at 50 to 200 ° C. under an atmosphere of an inert gas such as nitrogen, argon, helium or the like. By heating at about the same temperature, a recombination reaction occurs and the compound of the general formula (I-
The organic germanium compound of b) is produced. When the reaction temperature is lower than 50 ° C., the reaction does not substantially proceed. When the reaction temperature is higher than 200 ° C., polymerization of a vinylthio group occurs, and it becomes difficult to obtain a target product. Preferred reaction temperatures are in the range 100-180 ° C. The reaction time depends on the reaction temperature and cannot be determined unconditionally, but is usually from 10 minutes to 24 hours,
Preferably, it is about 30 minutes to 10 hours. After the reaction,
By distilling the reaction mixture under reduced pressure, the compound represented by the general formula (Ib), which is the organogermanium compound of the present invention, is obtained.

The above-mentioned tetraisocyanatogermanium used as one of the raw materials can be obtained by a known method, for example, the method described in Journal of the American Chemical Society (J. Am. Chem. Soc.), No. 65. Volume, first
It can be prepared according to the method described on page 783 (1943).

Next, an optical material obtained by using the organic germanium compound of the present invention will be described. This optical material can be produced, for example, by polymerizing the following polymerizable composition. The polymerizable composition includes a component (A) containing the organic germanium compound (a1) represented by the general formula (I) and a compound (b1) having two or more mercapto groups in one molecule. And a polymerizable composition containing the component (B).

In the polymerizable composition, the organic germanium compound (a1) in the component (A) is an essential component, and may be used alone or in combination of two or more. The organogermanium compound of the general formula (I), which is the compound (a1), comprises a compound of the formula (Ia) and a compound of the formula (I)
-B), the specific examples of which are as described above. Component (A) is a compound having two or more iso (thio) cyanate groups in one molecule as an optional component for appropriately improving the properties and the like of the obtained polymer.
(a2) and / or a compound (a3) having two or more vinyl groups in one molecule. The content of the organic germanium compound (a1) in the component (A) is preferably in the range of 1 to 100 mol%.

The component (A) may be suitably used
Examples of the compound (a2) having two or more iso (thio) cyanate groups in one molecule include xylylenediiso (thio) cyanate, 3,3'-dichlorodiphenyl-4,
4'-diiso (thio) cyanate, 4,4'-diphenylmethanediiso (thio) cyanate, hexamethylenediiso (thio) cyanate, 2,2 ', 5,5'-tetrachlorodiphenyl-4,4'- Diiso (thio) cyanate, tolylenediiso (thio) cyanate, bis (iso (thio) cyanatomethyl) cyclohexane, bis (4-
Iso (thio) cyanatocyclohexyl) methane, bis (4-iso (thio) cyanatomethylcyclohexyl) methane, cyclohexanediiso (thio) cyanate, isophoronediiso (thio) cyanate, 2,5-bis (iso (thio ) Cyanatomethyl) bicyclo [2,2,2] octane, 2,5-bis (iso (thio) cyanatomethyl) bicyclo [2,2,1] heptane, 2-iso (thio) cyanatomethyl-3- (3-iso ( Thio) cyanatopropyl) -5-iso (thio) cyanatomethyl-bicyclo [2,2,1] -heptane, 2-iso (thio) cyanatomethyl-3- (3-iso (thio) cyanatopropyl)-
6-iso (thio) cyanatomethyl-bicyclo [2,2,
1] heptane, 2-iso (thio) cyanatomethyl-2-
[3-iso (thio) cyanatopropyl] -5-iso (thio) cyanatomethyl-bicyclo [2,2,1] -heptane, 2-iso (thio) cyanatomethyl-2- (3-iso (thio) cyanato Propyl) -6-iso (thio) cyanatomethyl-bicyclo [2,2,1] -heptane, 2-iso (thio) cyanatomethyl-3- (3-iso (thio) cyanatopropyl) -6- (2-iso (Thio) cyanatoethyl) -bicyclo [2,2,1] -heptane, 2-iso (thio) cyanatomethyl-3- (3-iso (thio) cyanatopropyl) -6- (2-iso (thio) cyanatoethyl) -Bicyclo [2,2,1] -heptane, 2-iso (thio) cyanatomethyl-2- (3-iso (thio) cyanatopropyl) -5- (2-iso (thio) cyanatoethyl) -bicyclo [2 2,1] -heptane, 2-iso (thio) cyanatomethyl-2- (3-iso (thio) cyanatopropyl) -6- (2-iso (thio) cyanatoethyl) -bicyclo [2,2,1]- Heptane, 2,4-dithia-1,5-diisocyanatopentane and the like can be mentioned.
These may be used alone or in combination of two or more.

The above "iso (thio) cyanate group" means both isocyanate group and isothiocyanate group, and "iso (thio) cyanato" means both isocyanate and isothiocyanate.

Further, the compound (a) having two or more vinyl groups in one molecule, which is appropriately used in the component (A),
Examples of 3) include divinylbenzene, ethylene glycol di (meth) acrylate, 2,5-bis (vinylthiomethyl) -1,4-dithiane, trimethylolpropane tri (meth) acrylate, and at least 2 Examples include urethane-modified (meth) acrylate, epoxy-modified (meth) acrylate, and polyester-modified (meth) acrylate containing one or more (meth) acryloxy groups. These may be used alone or in combination of two or more. The above “(meth) acrylate” means both acrylate and methacrylate, and “(meth) acryloxy group” means both acryloxy group and methacryloxy group.

On the other hand, examples of the compound (b1) having two or more mercapto groups in one molecule, which is an essential component of the component (B), include 1,2-ethanedithiol, 1,3-propanedithiol, tetrakis Mercaptomethylmethane, pentaerythritol tetrakismercaptopropionate, pentaerythritol tetrakismercaptoacetate, 2,3-dimercaptopropanol, 1,2-benzenedithiol, 1,3-benzenedithiol,
5-bis (mercaptomethyl) -1,4-dithiane,
1,4-benzenedithiol, 1,3,5-benzenetrithiol, 1,2-dimercaptomethylbenzene,
1,3-dimercaptomethylbenzene, 1,4-dimercaptomethylbenzene, 1,3,5-trimercaptomethylbenzene, toluene-3,4-dithiol,
Examples thereof include 2,3-trimercaptopropane and 1,2,3,4-tetramercaptobutane. These may be used alone or in combination of two or more. The component (B) may contain an optional component for appropriately improving the properties and the like of the obtained polymer.

The content ratio of component (A) and component (B) in this polymerizable composition is such that the total number of iso (thio) cyanate groups and vinyl groups and the total number of mercapto groups are ± 10% of the stoichiometric ratio. % Is preferably selected. However, in order to appropriately modify the obtained optical material, only the vinyl group may be excessive.

The polymerizable composition may optionally contain additives such as an ultraviolet absorber, an antioxidant, a coloring inhibitor, and a fluorescent dye for improving the weather resistance, as long as the object of the present invention is not impaired. May be added. Further, a catalyst for improving the polymerization reactivity may be appropriately used.For example, an organic peroxide, an azo compound or a basic catalyst is effective for improving the reactivity between a mercapto group and a vinyl group, Organotin compounds, amine compounds and the like are effective for improving the reactivity between mercapto groups and iso (thio) cyanate groups.

An optical material can be produced using the organogermanium compound of the present invention, for example, according to the following method. First, a polymerizable composition containing the components (A) and (B) and various optional components used as needed is prepared. Next, the polymerizable composition is injected into a mold in which a glass or metal mold and a resin gasket are combined using a known casting polymerization method, and is cured by heating. At this time, in order to facilitate removal of the resin after molding, the mold may be subjected to a releasing treatment in advance, or a releasing agent may be mixed into the polymerizable composition. The polymerization temperature varies depending on the compound used, but is generally -20.
At + 150 ° C, the polymerization time is about 0.5-72 hours. The polymer released after polymerization uses a normal disperse dye,
It can be easily dyed in water or an organic solvent.
At this time, in order to further facilitate dyeing, a carrier may be added to the dye dispersion, or heating may be performed. The optical material thus obtained is not particularly limited, but is particularly preferably used as an optical product such as a plastic lens.

[0030]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The physical properties of the organic germanium compounds obtained in the examples and the physical properties of the polymers obtained in the examples and comparative examples were measured according to the following methods. <Physical properties of germanium compound> Refractive index (n _d ), Abbe number (ν _d ): 2 using Abbe refractometer 3T manufactured by Atago Co., Ltd.
It was measured at 5 ° C.

<Physical Properties of Polymer> (1) Refractive index (n _d ), Abbe number (ν _d ): Measured in the same manner as above. (2) Appearance: Observed with the naked eye. (3) Weather resistance: The plastic lens was set on a weather meter equipped with a sunshine carbon arc lamp, and after 200 hours, the plastic lens was taken out and the hue was compared with the plastic lens before the test. The evaluation criteria were no change (○), slight yellowing (△),
Yellowing (x). (4) Heat resistance: 0.5 mm using a TMA device manufactured by Rigaku Corporation
TMA with 98mN (10gf) load using φ pin
The measurement was performed, and the evaluation was performed based on the peak temperature of the chart obtained at a temperature increase of 10 ° C./min. (5) Optical distortion: Visual observation was performed by the Schlieren method. Those without distortion were evaluated as ○, and those with distortion were evaluated as x.

Example 1 Preparation of Tetra (vinylthio) germanium (G-1) To 136 ml of a tetrahydrofuran solution containing vinylmagnesium bromide at a concentration of 1.0 mol / l, 4.36 g of dried sulfur powder was added under a stream of argon. For 15 minutes at room temperature. To this reaction mixture, 7.29 g of germanium tetrachloride was added dropwise at 30 to 40 ° C. for 1 hour, and the mixture was further stirred at room temperature for 1 hour.

A saturated aqueous solution of ammonium chloride was added to the reaction mixture so as not to exceed 10 ° C., followed by extraction with n-hexane. The n-hexane extract was washed with water and dried. Then, n-hexane is distilled off from the extract, and the residue is distilled under reduced pressure to obtain tetra (vinylthio) germanium (G) having a boiling point of 87 ° C. at 2.4 Pa.
-1) 3.96 g was obtained.

This compound had a refractive index of 1.651 and an Abbe number of 22.5. The analysis results for determining the structure of this compound are shown below. ¹ H-NMR (solvent: CDC
l _3, internal standard substance: TMS); δ5.65 (dd, 2
H), δ 6.45 (dd, 1H) ¹³ C-NMR (solvent: CDCl ₃ , internal standard: TM)
S); δ124.2, δ124.3 IR; 3088, 3004, 1586, 1273, 95
4cm ^-1

Example 2 Tri (vinylthio) isocyanatogermanium (G-
In the production container of 2), 3.09 g of tetra (vinylthio) germanium obtained in Example 1 was mixed with 0.72 g of tetraisocyanatogermanium, and then replaced with argon, followed by stirring at 150 ° C. for 1 hour. did. Next, the reaction mixture was distilled under reduced pressure to obtain 2.44 g of tri (vinylthio) isocyanatogermanium (G-2) having a boiling point of 69 ° C. at 5.3 Pa.

This compound had a refractive index of 1.648 and an Abbe number of 33.9. The analysis results for determining the structure of this compound are shown below. ¹ H-NMR (solvent: CDCl ₃ , internal standard: TM
S); δ 5.83 (m, 2H), δ 6.31 (m, 1
H) ¹³ C-NMR (solvent: CDCl ₃ , internal standard: TM)
S); δ122.3, δ124.7, δ126.4 IR; 3088, 3004, 2230, 1586, 12
73, 954 cm ^-1

Example 3 Di (vinylthio) diisocyanatogermanium (G-
3) In a closed container, 24.66 g of tetra (vinylthio) germanium obtained in Example 1 was mixed with 19.20 g of tetraisocyanatogermanium, and the mixture was replaced with argon, and then 1.5 ° C at 150 ° C. Stirred for hours. Next, this reaction mixture was distilled under reduced pressure to obtain 18.86 g of di (vinylthio) diisocyanatogermanium (G-3) having a boiling point of 42 ° C. at 4.7 Pa.

This compound had a refractive index of 1.633 and an Abbe number of 35.5. The analysis results for determining the structure of this compound are shown below. ¹ H-NMR (solvent: CDCl ₃ , internal standard: TM
S); δ 5.83 (m, 2H), δ 6.31 (m, 1
H) ¹³ C-NMR (solvent: CDCl ₃ , internal standard: TM)
S); δ122.3, δ124.7, δ126.4 IR; 3088, 3004, 2230, 1586, 12
73, 954 cm ^-1

Example 4 Preparation of Vinylthiotriisocyanatogermanium (G-4)
In a production sealed container, 9.25 g of tetra (vinylthio) germanium obtained in Example 1 was mixed with 21.6 g of tetraisocyanatogermanium, followed by purging with argon, followed by stirring at 120 ° C. for 2 hours. Next, the reaction mixture was distilled under reduced pressure to give a boiling point of 6 at 253 Pa.
Vinylthiotriisocyanatogermanium (G-
4) 11.72 g was obtained.

This compound had a refractive index of 1.617 and an Abbe number of 38.2. The analysis results for determining the structure of this compound are shown below. ¹ H-NMR (solvent: CDCl ₃ , internal standard: TM
S); δ 5.83 (m, 2H), δ 6.31 (m, 1
H) ¹³ C-NMR (solvent: CDCl ₃ , internal standard: TM)
S); δ122.3, δ124.7, δ126.4

Application Example 1 Production of polymer from organogermanium compound of the present invention As shown in Table 1, 0.1 mol of tetra (vinylthio) germanium (G-1) obtained in Example 1, 2,4 -Dithia-1,5-diisocyanatopentane (I-1)
015 mol, 2,5-bis (mercaptomethyl) -1,
0.215 mol of 4-dithiane (T-1), 3 × 10 ^-6 mol of dibutyltin dichloride (C-1) as a polymerization catalyst, and 8 × 10 ⁶ azobisdimethylvaleronitrile (C-2)
^-4 mol of the mixture is mixed, uniformly stirred, poured into two glass molds for lens molding, and heated and polymerized at 50 ° C. for 10 hours, then at 60 ° C. for 5 hours, and further at 120 ° C. for 3 hours. A lens-shaped polymer was obtained. Table 2 shows properties of the obtained polymer. As shown in Table 2, the polymer obtained in this application example was colorless and transparent, and had a refractive index (n _d ) of 1.
733, the Abbe number (ν _d ) is as high as 32.8 (low dispersion), and weather resistance and heat resistance (116
° C) and no optical distortion. Therefore, this polymer is suitably used as an optical material.

APPLICATION EXAMPLES 2-6 Preparation of Polymer from Organic Germanium Compound of the Present Invention The component (A) containing the organic germanium compound (a1) of the present invention and the component (B) containing the polythiol compound (b1) are shown in Table 1. And the operation was performed in the same manner as in Application Example 1 except that the polymerization conditions were appropriately changed to obtain a lens-shaped polymer. The physical properties of these polymers are shown in Table 2 together with the physical properties of the polymer of Application Example 1. From Table 2, this application example 2
The polymer obtained in 6 is also colorless and transparent, and has a refractive index (n _d ).
Is very high, from 1.729 to 1.754, and the Abbe number (ν
_d ) was as high as 29.8 to 33.6 (low dispersion), excellent in weather resistance and heat resistance (109 to 141 ° C.), and had no optical distortion. Therefore, these polymers are suitably used as optical materials.

Application Comparative Example 1 As shown in Table 1, 0.1 mol of pentaerythritol tetrakismercaptopropionate (T-6), 0.2 mol of m-xylylene diisocyanate (I-4) and dibutyltin dichloride (C- 1) A mixture of 1.0 × 10 ⁻⁴ mol is uniformly stirred, poured into two glass molds for lens molding, heated at 50 ° C. for 10 hours, then at 60 ° C. for 5 hours, and further heated at 120 ° C. for 3 hours. Polymerization was performed to obtain a lens-shaped polymer. Table 2 shows properties of the obtained polymer. Table 2
Therefore, although the polymer obtained in Application Comparative Example 1 was colorless and transparent and no optical distortion was observed, n _d / v _d was 1.59 / 3.
6, the refractive index was low, and the heat resistance was inferior to 86 ° C.

Comparative Examples 2 and 3 The procedure of Comparative Example 1 was repeated, except that the raw material compositions shown in Table 1 were used, to obtain a lens-shaped polymer. Table 2 shows the physical properties of these polymers. From Table 2, the polymer of Application Comparative Example 2 has a low n _d / v _d of 1.67 / 28, and is relatively good in heat resistance (94 ° C.), but inferior in weather resistance and optical distortion. Was observed. Further, the polymer of Application Comparative Example 3 has a relatively high ν _d of 36, and is excellent in weather resistance.
Although it was colorless and transparent and no optical distortion was observed, heat resistance (90
° C.) is inferior, n _d is not so high as 1.70, and the polymer was brittle.

[0046]

[Table 1]

(Note) G-1: Tetra (vinylthio) germanium G-2: Tri (vinylthio) isocyanatogermanium G-3: Di (vinylthio) diisocyanatogermanium G-4: Vinylthiotriisocyanatogermanium I- 1: 2,4-dithia-1,5-diisocyanatopentane I-2: 1,3-bis (isothiocyanatomethyl) benzene I-3: 2,5-bis (isocyanatomethyl) -1,4
-Dithiane I-4: m-xylylene diisocyanate T-1: 2,5-bis (mercaptomethyl) -1,4-
Dithiane T-2: 2,3-dimercaptopropanol T-3: 1,2,3-trimercaptopropane T-4: 2,5-bis (mercaptomethyl) -1,4-
Oligomers of dithiane (average degree of polymerization 3.2) T-5: 1,2,3,4-tetramercaptobutane T-6: pentaerythritol tetrakis (mercaptopropionate) T-7: 1,3,5-tri Mercaptobenzene T-8: 2,3-epithiopropyl sulfide V-1: 2,5-bis (vinylthiomethyl) -1,4-
Dithiane C-1: dibutyltin dichloride C-2: azobisdimethylvaleronitrile C-3: triphenylphosphine

[0048]

[Table 2]

[0049]

The organic germanium compound of the present invention is a novel compound in which 1 to 4 vinylthio groups and 0 to 3 isocyanate groups are directly bonded to a germanium atom, and is suitable as a raw material of an optical material. Used. Further, the optical material comprising a polymer obtained by using the organogermanium compound of the present invention has a high refractive index and Abbe number, and has excellent heat resistance, weather resistance, and transparency.
Recording medium substrates used for lenses such as camera lenses, prisms, optical fibers, optical disks, magnetic disks, etc.
It is suitable as a material for producing optical products such as a coloring filter and an infrared absorption filter.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H049 VN01 VN02 VP01 VQ49 VR51 VR52 VR53 VR61 VR62 VR63 VR64 VS09 VS44 VS49 VU20 VW02 VW36

Claims (3)

[Claims] 1. An organic germanium compound represented by the general formula (I) Ge (SCHＣＨCH ₂ ) _x (NCO) _4-x ... (I) wherein x is an integer of 1 to 4. . 2. A method of reacting a vinyl magnesium halide with a simple substance of sulfur to obtain a vinylthiomagnesium halide and then reacting the vinylthiomagnesium halide with a tetrahalogenogermanium, wherein Ge (SCH = CH) ₂ ) ₄ ... A method for producing tetra (vinylthio) germanium represented by (Ia). 3. General formula (Ib) Ge (SCH = CH ₂ ) _y (NCO) _4-y ... (I−) characterized by reacting tetra (vinylthio) germanium with tetraisocyanatogermanium. b) (wherein, y represents an integer of 1 to 3).