JP2007269648A - Organic germanium compound and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic germanium compound useful as a raw material for an optical material having high refractive index and Abbe number and a method for producing the compound in high efficiency. <P>SOLUTION: The organic germanium compound is produced by reacting an organic germanium compound expressed by formula (1) with sodium ethylenedithiolate and a tetrahalogenogermanium. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  In recent years, plastics are used in various optical applications such as lenses because they are lighter than glass and are difficult to break and can be easily dyed. As an optical plastic material, poly (diethylene glycol bisallyl carbonate) (CR-39) or poly (methyl methacrylate) is generally used. However, since these plastics have a refractive index of 1.50 or less, when they are used, for example, as a lens material, the lens becomes thicker as the power increases, and the superiority of the plastic, which is advantageous in terms of light weight, is impaired. . In particular, a strong concave lens is not preferable because the periphery of the lens becomes thick and birefringence and chromatic aberration occur. In addition, thick lenses in eyeglass applications tend to degrade aesthetics. In order to obtain a thin lens, it is effective to increase the refractive index of the material. In general, in glass and plastic, the Abbe number decreases as the refractive index increases, and as a result, their chromatic aberration increases. Therefore, a plastic material having a high refractive index and Abbe number is desired.

Examples of plastic materials having such performance include (1) polyurethane obtained by polyaddition of a polyol having bromine in the molecule and polyisocyanate (Patent Document 1), and (2) polyaddition of polythiol and polyisocyanate. Has been proposed (Patent Document 2, Patent Document 3). In particular, as polythiol used as the raw material for polythiourethane (2), a branched chain with an increased content of sulfur atoms (Patent Documents 4 and 3) and a dithian structure to increase the content of sulfur atoms are introduced. Polythiols (Patent Documents 5 and 6) have been proposed. Furthermore, (3) alkyl sulfide polymers having episulfide as a polymerization functional group have been proposed (Patent Documents 7 and 8).
However, although the polyurethane of the above (1) has a slightly improved refractive index, it has disadvantages such as a low Abbe number and inferior light resistance, a high specific gravity, and a loss of lightness. . Further, 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 about 1.60 to 1.68, for example, The Abbe number is lower than that of optical inorganic glass having a high ratio, and the Abbe number has to be increased. Furthermore, the alkyl sulfide polymer (3) has an Abbe number of 36 as an example, and the refractive index is increased to 1.70, and the lens obtained using this polymer is extremely thin and light. However, a plastic material that further increases the refractive index and the Abbe number is desired.

JP 58-164615 Japanese Patent Publication No. 4-58489 Japanese Patent Laid-Open No. 5-148340 JP-A-2-270859 Japanese Patent Publication No. 6-5323 JP 7-118390 A JP-A-9-72580 JP-A-9-110979

  The present invention has been made to solve such problems, and an object of the present invention is to provide a compound that can provide an optical product having a high refractive index and a high Abbe number when the refractive index is taken into consideration. It is.

As a result of intensive studies to achieve the above object, the present inventor has four sulfides bonded to a germanium atom and has two vinyl groups, and these two compounds centering on the germanium atom. It has been found that an organic germanium compound forming a cyclic structure is a novel compound and can meet the above-mentioned purpose, and that it can be efficiently obtained by a specific method. The invention has been completed.
That is, the present invention provides the formula (1)

And an organic germanium compound represented by the above formula (1) characterized by reacting sodium ethylenedithiolate with tetrahalogenogermanium.

  The organic germanium compound represented by the formula (1) is useful as a raw material for optical materials having a high refractive index and high Abbe number, and is particularly useful for lenses.

  The organic germanium compound of the present invention has the formula (1)

As shown in the above formula (1), four sulfides are bonded to a germanium atom, and these and two vinyl groups form two cyclic structures around the germanium atom. It is characterized by being.
In general, the refractive index of a substance increases as the refractive index (atomic refraction) of the constituent elements increases and the molecular volume decreases. Compared with a vinyl sulfide compound having a skeleton composed of carbon atoms (atomic refraction = 2.42), the refractive index of the organic germanium compound of the present invention into which germanium atoms (atomic refraction = 4.1) are introduced is significantly increased, Therefore, the refractive index of the polymer obtained using this compound as a raw material also increases.
Since the organogermanium compound of the present invention is bifunctional and the functional group is composed only of elemental sulfur, the refractive index of the polymer obtained by using it is a molecule caused by an increase in crosslink density. As volume decreases, it increases. In order to maintain the high crosslinking density and increase the refractive index without decreasing the Abbe number, it is desirable that the vinylthio group be directly bonded to the germanium atom. Therefore, the optical properties of the polymer obtained using the organogermanium compound of the present invention can be enhanced.

  The method for producing the organic germanium compound represented by the formula (1) is not particularly limited as long as the compound can be obtained, but it is preferably produced by the production method of the present invention.

  In the production method of the present invention, as shown in the above reaction formula, ethylenedithiolate sodium is used as a starting material, and this is reacted with tetrahalogenogermanium to produce an organogermanium compound represented by the formula (1). Is the method. In the above reaction formula, X represents a halogen atom, and specific examples include a chlorine atom, a bromine atom and an iodine atom. As the tetrahalogenogermanium, germanium tetrachloride is preferable.

  The organic germanium compound represented by the formula (1) is 1,4,6,9-tetrathia-5-germa [4.4] nona-2,7-diene, and is efficiently produced by the method of the present invention described below. Can be manufactured. That is, to a dispersion obtained by adding sodium ethylenedithiolate to an organic solvent, a mixture obtained by dissolving tetrahalogenogermanium in an organic solvent is dropped in the range of about 0 to 60 ° C., preferably in the range of 10 to 40 ° C. The reaction is carried out by stirring for about 6 hours, and after the reaction, the organic layer is washed with water, dried and concentrated to obtain the desired organic germanium compound.

An example of a method for producing the organic germanium compound represented by the general formula (1) is shown below.
After adding ethylene dithiolate sodium to dehydrated ethanol, germanium tetrachloride dissolved in 8 ml of dehydrated ethanol is dropped in the range of 14 to 17 ° C. Stir further for 2 hours after the end of dropping. After completion of the reaction, ethanol was concentrated, dichloromethane and pure water were added, and the organic layer was dried over anhydrous magnesium sulfate and concentrated to obtain the desired 1,4,6,9-tetrathia-5-germa [4.4] nona. 2,7-diene crystals can be obtained.
Examples of the organic solvent used in the present invention include dehydrated organic solvents such as methanol, ethanol, toluene, n-hexane and chloroform, and dehydrated methanol and dehydrated ethanol are preferred. The amount of the organic solvent to be used is about 0.1 to 1000 liters, preferably 1 to 100 liters per mole of sodium ethylenedithiolate or halogenogermanium. The ethylene dithiolate sodium and tetrahalogeno germanium are used in an amount of usually about 0.2 to 5 mol, preferably 0.8 to 1.2 mol, of ethylene dithiolate sodium relative to 1 mol of the halogen group in the tetrahalogenogermanium.

  The ethylene dithiolate sodium used as one of the raw materials is prepared according to a known method, for example, the method described in “Inorg. Chem.” Vol. 7, page 340 (1968). be able to.

  The organic germanium compound of the present invention is suitably used as a raw material for optical materials, and this optical material is suitably used for the production of optical products, particularly lenses. Hereinafter, optical products obtained using the organogermanium compound of the present invention will be described. In this optical product, a polymerizable composition containing a component A containing the organogermanium compound (a1) represented by the formula (1) and a component B containing a compound having a mercapto group and / or a hydroxyl group is polymerized. The polymer obtained by making it can be used.

In addition to the organogermanium compound (a1) represented by the formula (1), the component A has a vinyl group in one molecule and has one molecule in order to improve the physical properties of the polymer as appropriate. One or more compounds (a2) having a total number of vinyl groups of 1 or more may be included.
The amount of the organic germanium compound (a1) represented by the formula (1) may be appropriately selected according to the situation, but is usually 50 to 100 mol% with respect to the total amount of the component A, preferably 80 to 100 mol%.

  As the compound having a vinyl group used as the component (a2), specifically, divinylbenzene, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, at least two (meta) in one molecule ) Urethane-modified (meth) acrylates containing acryloxy groups, epoxy-modified (meth) acrylates, polyester-modified (meth) acrylates, and the like. These may be used alone or in combination of two or more. The (meth) acrylate means both acrylate and methacrylate, and the (meth) acryloxy group means both acryloxy group and methacryloxy group.

The organogermanium compound of the present invention is preferably a compound having a mercapto group and / or a hydroxyl group in one molecule as the polymerization partner B component, and a total number of mercapto groups and hydroxyl groups in one molecule of 2 or more. By selecting and polymerizing with this, a lens material having a high refractive index, a high Abbe number, transparency and good heat resistance is provided.
Specific examples of the B component compounds include trimethylolpropane, dimercaptomethane, 1,2-ethanedithiol, 1,3-propanedithiol, tetrakismercaptomethylmethane, pentaerythritol tetrakismercaptopropionate, pentaerythritol tetrakismercaptoacetate. 2-mercaptoethanol, 2,3-dimercaptopropanol, 1,2-dihydroxy-3-mercaptopropane, 1,2,3-trimercaptopropane, 4-mercaptophenol, 1,2-benzenedithiol, 1,3 -Benzenedithiol, 1,4-benzenedithiol, 1,3,5-benzenetrithiol, 1,2-dimercaptomethylbenzene, 1,3-dimercaptomethylbenzene, 1,4-dimercaptomethylbenzene, 1, 3,5-trimercaptomethylbenzene, toluene-3,4-dithio , 4,4'-dihydroxyphenyl sulfide and bis (mercaptomethyl) -1,4,6,9- Tetorachia -5 Germa - spiro [4.4] nonane, and the like. These may be used alone or in combination of two or more.

  Further, an optical product can be produced by adding an episulfide compound as a C component to these components. Examples of the episulfide compound include bis (β-epithiopropylthio) methane, 1,2-bis (β-epithiopropylthio) ethane, 1,3-bis (β-epithiopropylthio) propane, 1,2 -Bis (β-epithiopropylthio) propane, 1- (β-epithiopropylthio) -2- (β-epithiopropylthiomethyl) propane, 1,4-bis (β-epithiopropylthio) butane 1,3-bis (β-epithiopropylthio) butane, 1- (β-epithiopropylthio) -3- (β-epithiopropylthiomethyl) butane, 1,5-bis (β-epithio) Propylthio) pentane, 1- (β-epithiopropylthio) -4- (β-epithiopropylthiomethyl) pentane, 1,6-bis (β-epithiopropylthio) hexane, 1- (β-epi Opropylthio) -5- (β-epithiopropylthiomethyl) hexane, 1- (β-epithiopropylthio) -2-[(2-β-epithiopropylthioethyl) thio] ethane, 1- (β- A chain organic compound such as epithiopropylthio) -2-[[2- (2-β-epithiopropylthioethyl) thioethyl] thio] ethane; tetrakis (β-epithiopropylthiomethyl) methane, 1,1-tris (β-epithiopropylthiomethyl) propane, 1,5-bis (β-epithiopropylthio) -2- (β-epithiopropylthiomethyl) -3-thiapentane, 1,5- Bis (β-epithiopropylthio) -2,4-bis (β-epithiopropylthiomethyl) -3-thiapentane, 1- (β-epithiopropylthio) -2,2-bis (β-epithiopro) Pyrthiomethyl) -4-thiahexane, 1,5,6-tris (β-epithiopropylthio) -4- (β-epithiopropylthiomethyl) -3-thiahexane, 1,8-bis (β-epithiopropyl) Thio) -4- (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (β-epithiopropylthio) -4,5-bis (β-epithiopropylthiomethyl)- 3,6-dithiaoctane, 1,8-bis (β-epithiopropylthio) -4,4-bis (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (β-epi Thiopropylthio) -2,4,5-tris (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (β-epithiopropylthio) -2,5-bis (β- Epithiopropylthio Methyl) -3,6-dithiaoctane, 1,9-bis (β-epithiopropylthio) -5- (β-epithiopropylthiomethyl) -5-[(2-β-epithiopropylthioethyl) thiomethyl -3,7-dithianonane, 1,10-bis (β-epithiopropylthio) -5,6-bis [(2-β-epithiopropylthioethyl) thio] -3,6,9-trithiadecane, 1,11-bis (β-epithiopropylthio) -4,8-bis (β-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis (β-epithiopropyl) Thio) -5,7-bis (β-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis (β-epithiopropylthio) -5,7-[(2- β-epithiopropylthioethyl) thio Til] -3,6,9-trithiaundecane, 1,11-bis (β-epithiopropylthio) -4,7-bis (β-epithiopropylthiomethyl) -3,6,9-trithia Branched organic compounds such as undecane and compounds in which at least one hydrogen of the episulfide group of these compounds is substituted with a methyl group, etc .; 1,3 and 1,4-bis (β-epithiopropylthio) cyclohexane, 1 , 3 and 1,4-bis (β-epithiopropylthiomethyl) cyclohexane, bis [4- (β-epithiopropylthio) cyclohexyl] methane, 2,2-bis [4- (β-epithiopropylthio) ) Cyclohexyl] propane, bis [4- (β-epithiopropylthio) cyclohexyl] sulfide, 2,5-bis (β-epithiopropylthiomethyl) -1,4 Dithiane, 2,5-bis (β-epithiopropylthioethylthiomethyl) -1,4-dithiane, 4,5-bis (epithiopropylthio) -1,3-dithiolane, 2,3-bis (epi Thiopropylthio) -1,4-dithiane, 3,4-bis (epithiopropylthio) -bicyclo [4,3,0] -2,5,7,9-tetrathianonane, 2,3-bis ( Cycloaliphatic and heterocyclic organic compounds such as (epithiopropylthio) -1,4-benzodithiane, and compounds in which at least one hydrogen of the episulfide group of these compounds is substituted with a methyl group; 1, 3 and 1, 4-bis (β-epithiopropylthio) benzene, 1,3 and 1,4-bis (β-epithiopropylthiomethyl) benzene, bis [4- (β-epithiopropylthio) phenyl] methane, 2 , 2-bis [4- (β-epithiopropylthio) phenyl] propane, bis [4- (β-epithiopropylthio) phenyl] sulfide, bis [4- (β-epithiopropylthio) phenyl] sulfone And aromatic organic compounds such as 4,4′-bis (β-epithiopropylthio) biphenyl, and compounds in which at least one hydrogen of the episulfide group of these compounds is substituted with a methyl group. These may be used alone or in combination of two or more.

  Furthermore, in order to improve the weather resistance of optical products obtained using the organogermanium compound of the present invention, additives such as ultraviolet absorbers, antioxidants, anti-coloring agents and fluorescent dyes may be added as appropriate. In addition, a catalyst for improving polymerization reactivity may be used as appropriate. For example, a basic catalyst such as an organic peroxide, an azo compound, or an amine compound is effective for improving the reactivity between a mercapto group and a vinyl group. Is.

The optical product obtained by using the organogermanium compound of the present invention can be produced, for example, according to the following method.
First, a uniform composition containing the polymerizable composition and various additives used as necessary is prepared. Next, this composition is poured into a mold in which a glass or metal mold and a resinous gasket are combined using a known casting polymerization method, and is cured by heating. At this time, in order to make it easy to take out the resin after molding, the mold may be released in advance, or a release agent may be mixed with the composition. Although the polymerization temperature varies depending on the compound used, it is generally −20 to + 150 ° C. and the polymerization time is about 0.5 to 72 hours. The polymer released after polymerization can be easily dyed in water or an organic solvent using a normal disperse dye. At this time, in order to further facilitate dyeing, a carrier may be added to the dye dispersion, or it may be heated. The optical product thus obtained is not particularly limited, but is particularly preferably used as an optical product such as a plastic lens. Here, examples of optical products include plastic lenses, optical fibers, information recording substrates, infrared absorption filters, and colored filters.

Such a plastic lens can be dyed with a dye, and in order to improve scratch resistance, fine particles of tin oxide, silicon oxide, zirconium oxide, titanium oxide, etc. are added to an organosilicon compound or an acrylic compound. A cured film may be formed on the plastic lens using a coating liquid containing an inorganic substance or the like. In addition, a primer layer mainly composed of polyurethane may be formed on the plastic lens in order to improve impact resistance.
Furthermore, in order to impart antireflection performance, an antireflection film made of an inorganic substance such as silicon oxide, titanium dioxide, zirconium oxide, or tantalum oxide may be formed on the cured film. In order to improve water repellency, a water repellent film made of an organosilicon compound containing a fluorine atom may be formed on the antireflection film.
When this plastic lens is used for spectacles, an ultraviolet absorber may be added for the purpose of protecting the resin or eyes from ultraviolet rays, and an infrared absorber for the purpose of protecting eyes from infrared rays.
Furthermore, for the purpose of maintaining or improving the aesthetics of the resin, it can be bluing with the addition of an antioxidant or a small amount of pigment.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In addition, the physical property of the organic germanium compound obtained by the Example, and the physical property of the polymer obtained by the application example and the application comparative example were measured in accordance with the method shown below.

<Physical properties of organogermanium compounds>
Refractive index (n _D ), Abbe number (ν _D ): Measured at 25 ° C. using an Abbe refractometer DR-M4 manufactured by Atago Co., Ltd.
<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.

Example 1
Synthesis of 1,4,6,9-tetrathia-5-germa [4.4] nona-2,7-diene After adding 6.83 g of sodium ethylenedithiolate to 110 ml of dehydrated ethanol, 5.38 germanium tetrachloride dissolved in 8 ml of dehydrated ethanol g was dripped in the range of 14-17 degreeC. After completion of the dropwise addition, the mixture was further stirred for 2 hours. After completion of the reaction, ethanol was concentrated, 100 ml of dichloromethane and 50 ml of pure water were added, and the organic layer was dried over anhydrous magnesium sulfate and concentrated to obtain 1,4,6,9-tetrathia-5-germa [4.4] nona. Pale yellow crystals of -2,7-diene (5.2 g, yield 82%) were obtained.
The analysis result of ¹ H-NMR (solvent: CDCl ₃ ) for specifying the structure of this compound is shown below.
δ: 6.50 (1H, s, -CH = CH-)

Production of optical product made of polymer Application Example 1
1,4,6,9-tetrathia-5-germa [4.4] nona-2,7-diene (T1) 0.1 mol obtained in Example 1, bis (mercaptomethyl) -1,4,6,9- A mixture of tetrathia-5-germer-spiro [4.4] nonane (T2) 0.1 mol and dicyclohexylmethylamine (CT1) 1.0 × 10 ⁻⁴ mol is uniformly stirred at 60 ° C. to form two lens molding glass molds. The polymer was heated and polymerized at 60 ° C. for 10 hours, then at 90 ° C. for 5 hours, and further at 110 ° C. for 3 hours to obtain a lens-shaped polymer. The obtained polymer was light yellow and transparent, the refractive index (n _D ) was as high as 1.81, and the Abbe number (ν _D ) was as high as 26.2. Therefore, the obtained polymer was suitable as an optical product.

Application example 2
1,4,6,9-tetrathia-5-germa [4.4] nona-2,7-diene (T1) 0.1 mol obtained in Example 1, bis (mercaptomethyl) -1,4,6,9- Tetrathia-5-germer-spiro [4.4] nonane (T2) 0.14 mol, 4,5-bis (epithiopropylthio) -1,3-dithiolane (T3) 0.33 mol and dicyclohexylmethylamine (CT1) 1.0 × 10 ^{− 4} mol of the mixture is stirred uniformly at 30 ° C, poured into two lens molding glass molds, and heated and polymerized at 60 ° C for 10 hours, then at 90 ° C for 5 hours, and further at 110 ° C for 3 hours. A shaped polymer was obtained. The obtained polymer was colorless and transparent, the refractive index (n _D ) was as high as 1.77, and the Abbe number (ν _D ) was as high as 29.3. Therefore, the obtained polymer was suitable as an optical product.

Application example 3
1,4,6,9-tetrathia-5-germa [4.4] nona-2,7-diene (T1) 0.097 mol, 1,2,3-trimercaptopropane (T4) 0.067 mol obtained in Example 1 , 4,5-bis (epithiopropylthio) -1,3-dithiolane (T3) 0.021 mol and dicyclohexylmethylamine (CT1) 1.0 × 10 ⁻⁴ mol were uniformly stirred at 30 ° C. The polymer was poured into a glass mold for lens molding and heated and polymerized at 60 ° C. for 10 hours, then at 90 ° C. for 5 hours and further at 110 ° C. for 3 hours to obtain a lens-shaped polymer. The polymer obtained in the application example was colorless and transparent, the refractive index (n _D ) was as high as 1.78, and the Abbe number (ν _D ) was as high as 29.5. Therefore, the obtained polymer was suitable as an optical product.

Application comparison example 1
Manufacture of optical products made of polymer As shown in Table 1, 0.1 mol of pentaerythritol tetrakismercaptopropionate (T5), 0.2 mol of m-xylylene diisocyanate (T6) and 1.0 × 10 ^-4 mol of dibutyltin dichloride (CT2) The mixture was uniformly stirred and poured into two lens-molding glass molds, and heat-polymerized at 50 ° C. for 10 hours, then at 60 ° C. for 5 hours, and further at 120 ° C. for 3 hours to obtain a lens-shaped polymer. It was. Table 1 shows various physical properties of the obtained polymer. As can be seen from Table 1, the obtained polymer was colorless and transparent, and no optical distortion was observed, but n _D / ν _D was 1.59 / 36 and the refractive index was low.

Application Comparative Example 2 and Application Comparative Example 3
Manufacture of optical product made of polymer Except that the raw material composition shown in Table 1 was used, the same operation as in Application Comparative Example 1 was performed to obtain a lens-shaped polymer. Table 1 shows the physical properties of these polymers. As can be seen from Table 1, the polymer of Application Comparative Example 2 had a low n _D / ν _D of 1.67 / 28, coloration was observed, and optical distortion was observed. In addition, the polymer of Comparative Example 3 of this application had a relatively high ν _D of 36, was colorless and transparent, and no optical distortion was observed, but the n _D was not so high as 1.70, and the polymer was fragile. It was.

The abbreviations shown in Table 1 represent the following.
T1: 1,4,6,9-tetrathia-5-germa [4.4] nona-2,7-diene T2: bis (mercaptomethyl) -1,4,6,9-tetrathia-5-germer-spiro [4.4 Nonane T3: 4,5-bis (epithiopropylthio) -1,3-dithiolane T4: 1,2,3-trimercaptopropane T5: pentaerythritol tetrakismercaptopropionate T6: m-xylylene diisocyanate T7: 1,3,5-trimercaptobenzene T8: 2,3-epithiopropyl sulfide CT1: dicyclohexylmethylamine CT2: dibutyltin dichloride CT3: tetra (n-butyl) phosphonium bromide

  The organic germanium compound of the present invention is a novel compound having a high sulfur content in which two reactive substituents containing a vinyl group are bonded to a germanium atom, and is suitably used as a raw material for optical materials. Further, the optical material obtained using the organogermanium compound of the present invention has a high refractive index and Abbe number, and is excellent in weather resistance and transparency. Therefore, lenses such as eyeglass lenses and camera lenses, prisms, optical fibers, and optical disks It is suitable as a material for producing optical products such as information recording medium substrates, colored filters, infrared absorption filters and the like used for magnetic disks.

Claims (2)

Following formula (1)

An organic germanium compound represented by: The following formula (1), wherein sodium dithiolate sodium and tetrahalogenogermanium are reacted

The manufacturing method of the organic germanium compound represented by these.