JP4459646B2 - Method for producing polycyclic aromatic vinyl compound - Google Patents

Description

  The present invention relates to a method for producing a polycyclic aromatic vinyl compound useful for electronic materials, optical materials and the like with high purity.

  Polycyclic aromatic vinyl compounds can impart properties such as high heat resistance, low dielectric constant, low dielectric loss, high refractive index, flame retardancy, and low moisture absorption to various polymer polymers. The use in is expected. For example, in Japanese Patent Application Laid-Open No. 08-048725, vinyl biphenyl is applied as a raw material for a resin having high refraction and high heat resistance. Japanese Patent Laid-Open No. 2002-018293 shows that divinylbiphenyl is useful as a raw material for a cation exchange resin having high heat resistance. In Japanese Patent Application Laid-Open No. 2001-294623, acenaphthylene is used as a material imparting flame retardancy.

  The polycyclic aromatic vinyl compound can be produced by coupling, cyclization, or dehydrogenation of ethyl polycyclic aromatic compound, etc. of the monocyclic aromatic vinyl compound. Since it contains impurities other than the above, it has been desired to increase its purity. In particular, when a polycyclic aromatic vinyl compound is used as a polymer raw material, it should not contain impurities that do not have a vinyl group as much as possible in order to reduce the strength, heat resistance, and dielectric properties of the polymer produced. It was essential to improve the purity.

  However, since polycyclic aromatic vinyl compounds have high boiling points and are easily polymerized, it is practically impossible to apply distillation used to produce high purity products with monocyclic vinyl compounds. For example, in Patent Document 1, when a vinyl compound is distilled at 65 to 150 ° C., a vinyl compound is added by adding a nitroso compound such as N-nitroso-N, N′-di-pentyl-p-phenylenediamine as a polymerization inhibitor. Prevents polymerization. However, since polycyclic aromatic vinyl compounds generally have a high boiling point, distillation under ultrahigh vacuum is required, and the polymerization inhibitor used in Patent Document 1 volatilizes and polymerization occurs during distillation.

Japanese Patent Laid-Open No. 11-140001 JP-A-10-139696 "Basics of Organic Chemistry", Monson Shelton, Tokyo Kagaku Doujin, p. 71

  Patent Document 2 describes high purification of divinylbiphenyl by adsorption. However, in order to obtain divinylbiphenyl close to 100% in a high yield, a large number of stages are required, which is not industrial. Moreover, about divinylbiphenyl, even if it cooled to -30 degreeC, the crystal | crystallization did not precipitate and the purity improvement by cooling crystallization was impossible substantially.

  Non-Patent Document 1 discloses a method for purifying hexene. In this method, the unsaturated bond part of hexene containing impurities with close boiling points can be easily added with bromine to dibromohexane, and the boiling point difference between dibromohexane and impurities becomes large, making distillation purification easy. And the adduct bromine from dibromohexane is easily debrominated into hexene. However, this method is difficult to apply to the separation of polycyclic aromatic compounds that are difficult to distill.

  An object of the present invention is to provide a method for producing a high-purity polycyclic aromatic vinyl compound by purifying a polycyclic aromatic vinyl compound that cannot be purified by ordinary methods such as distillation, recrystallization, and adsorption.

  As a result of diligent investigations to solve the above problems, the present inventor has added a halogen to the vinyl group of the polycyclic aromatic vinyl compound to protect it once, and by changing its properties greatly, It was found that a high-purity polycyclic aromatic vinyl compound can be produced by removing the adduct after purification, and completing the present invention.

That is, in the present invention, in separating and producing a polycyclic aromatic vinyl compound from a polycyclic aromatic vinyl compound-containing oil, (1) hydrogen halide, halogen or water is added to the vinyl group of the polycyclic aromatic vinyl compound. addition step for adding is used as the additional agent from the purification step, and (3) purified polycyclic aromatic vinyl compound derivative is purified by recrystallization (2) polycyclic aromatic vinyl compound derivatives produced by the additional step A process for producing a polycyclic aromatic vinyl compound, comprising a deaddition agent step for desorption.

  Here, examples of the polycyclic aromatic vinyl compound include one or more selected from monovinylbiphenyl, divinylbiphenyl, monovinylnaphthalene, divinylnaphthalene, and acenaphthylene. In the case of divinylbiphenyl, 3,3′-divinylbiphenyl can be mentioned, and the purification method in the purification step is preferably recrystallization.

Hereinafter, the present invention will be described in detail.
Examples of the polycyclic aromatic vinyl compound-containing oil used as a raw material in the present invention include crude polycyclic aromatic vinyl compounds. The crude polycyclic aromatic vinyl compound can be produced by coupling a monocyclic aromatic vinyl compound, cyclization, or dehydrogenation of an ethyl polycyclic aromatic compound. In this crude polycyclic aromatic vinyl compound, it is advantageous to remove in advance components that are easily separated such as low-boiling substances and moisture and solids.

  For example, divinylbiphenyl and divinylnaphthalene can be obtained by dehydrogenating diethylbiphenyl and diethylnaphthalene, but monoethylvinylbiphenyl and monoethylvinylnaphthalene are produced as by-products, and various isomers are produced and unreacted raw materials Often remain. The method of the present invention is effective for the separation of divinyl compounds and monovinyl compounds, and the separation of isomers having different vinyl group substitution positions. In addition, acenaphthylene is obtained by dehydrogenating acenaphthene. In this case, impurities such as unreacted acenaphthene are also present. Therefore, the polycyclic aromatic vinyl compound-containing oil used as a raw material in the present invention contains 5% or more, preferably 10% or more of a vinyl compound containing impurities as described above and intended for high purity. More preferably, it is about 20 to 90%.

The substance to be added to the vinyl group of the polycyclic aromatic vinyl compound (hereinafter referred to as an additive) may be anything as long as it is stable in the added state and can be removed later. One selected from hydrogen halide, halogen, and water is used as an additive for ease and ease of handling. Incidentally, the halogen in the present invention are usually expressed in X _2, it is represented by hydrogen halide usually HX. Here, X represents a halogen which is F, Cl, Br or I, and is preferably Cl, Br or I.

  As a hydrogen halide used as an additive, hydrogen bromide, hydrogen chloride, and hydrogen iodide are preferable. The addition temperature is preferably 0 ° C to 200 ° C. Addition of hydrogen halide adds H and X atoms to each carbon of the vinyl group, and the olefinic double bond disappears.

  As the halogen used as the additive, liquid bromine and chlorine gas are preferable. Fluorine is not preferred because it is too reactive and iodine is too weak. The addition reaction of liquid bromine and chlorine gas proceeds without catalyst. The addition temperature is preferably −20 ° C. to 100 ° C. The addition of halogen adds two X atoms, one for each carbon of the vinyl group, and the olefinic double bond disappears.

  When water used as an adduct agent is used, the addition is preferably performed in the presence of an acid catalyst. As the acid catalyst, mineral acids such as sulfuric acid, hydrochloric acid and phosphoric acid and solid acid catalysts such as zeolite are preferable. The addition temperature is preferably 0 ° C to 200 ° C for mineral acids and 50 ° C to 300 ° C for solid acid catalysts. Addition of water adds H and OH groups to each carbon of the vinyl group, and the olefinic double bond disappears.

  Solvents can be used in all addition reactions. Solvents used include alcohols such as methanol, ethanol and propanol, aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, paraffins such as hexane, heptane, cyclohexane and methylcyclohexane, methyl acetate and acetic acid. Examples thereof include, but are not limited to, acetates such as ethyl and propyl acetate, and oxygen-containing solvents such as dioxane, tetrahydrofuran and dimethyl carbonate.

  Since the polycyclic aromatic vinyl compound derivative obtained in the addition step does not have an olefinic double bond, it is highly purified by applying a general purification method. The general purification method used in the present invention requires any one of recrystallization, adsorption and adduct separation, but other separation methods other than these may be used in combination. As other separation methods, operations such as washing, drying, and extraction can be considered. In addition, the recrystallization here refers to a liquid substance or a slurry-like substance on which a solid is precipitated to precipitate a sufficient amount of crystals, and the crystals are solid-liquid separated, rinsed, recrystallized, and purified to a high purity. A series of operations for obtaining a simple crystal. By adding an adduct to the vinyl group, the polymerizability is lost, and the properties of the vinyl compound and the non-vinyl compound are greatly dissociated, so that the separation becomes easy. Further, when the monovinyl compound and the divinyl compound are separated, the same effect as described above occurs even if there is a difference in degree. Basically, since the purity of the polycyclic aromatic vinyl compound derivative in this process becomes the purity of the polycyclic aromatic vinyl compound of the final product, the purity of the polycyclic aromatic vinyl compound derivative reaches the purity required for the final product. Need to be increased.

  Next, the high-purity polycyclic aromatic vinyl compound, which is the target product, is obtained by subjecting it to a deaddition agent step for removing the adduct from the high-purity polycyclic aromatic vinyl compound derivative obtained in the purification step. In this step, an elimination reaction of the once added adduct is caused.

In the elimination reaction of the high-purity polycyclic aromatic vinyl compound derivative to which hydrogen halide is added, dehydrogenation is performed using a basic reagent to regenerate the vinyl group. As the basic reagent, one obtained by dissolving an alkali hydroxide in water or alcohol can be used, and among them, potassium hydroxide dissolved in ethanol is preferably used. Also, the vinyl group can be regenerated by changing the added halogen atom to a hydroxyl group and then dehydrating it.
In the elimination reaction of the high-purity polycyclic aromatic vinyl compound derivative to which halogen is added, the vinyl group is regenerated by dehalogenation using a metal reagent or the like. Examples of the dehalogenating agent include, but are not limited to, metallic zinc. When metallic zinc is used, the desorption temperature is preferably 30 ° C to 150 ° C.
In the elimination reaction of the high-purity polycyclic aromatic vinyl compound derivative to which water has been added, dehydration is performed using an acid catalyst to regenerate the vinyl group. As the acid catalyst, mineral acids such as sulfuric acid and phosphoric acid, and solid acids such as alumina and zeolite can be used.

  A solvent can be used in the elimination reaction of all the additives. Solvents used include alcohols such as methanol, ethanol and propanol, aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, paraffins such as hexane, heptane, cyclohexane and methylcyclohexane, methyl acetate and acetic acid. Examples thereof include, but are not limited to, acetates such as ethyl and propyl acetate, and oxygen-containing solvents such as dioxane, tetrahydrofuran and dimethyl carbonate.

Further, when the operating temperature of the elimination reaction is 10 ° C. or higher, it is preferable to add a polymerization inhibitor such as tertiary butyl catechol.
After completion of the elimination reaction, a more suitable high-purity polycyclic aromatic vinyl compound can be obtained by performing an appropriate post-treatment as necessary.

  According to the method for producing a polycyclic aromatic vinyl compound of the present invention, it is possible to obtain a high-purity polycyclic aromatic vinyl compound that has been difficult to obtain by ordinary methods such as recrystallization and distillation. Conventional low-purity polycyclic aromatic vinyl compounds were difficult to resinize themselves, but the high-purity polycyclic aromatic vinyl compounds obtained in the present invention have no impurities that hinder resination, and various high It is possible to impart properties such as high heat resistance, low dielectric constant, low dielectric loss, high refractive index, flame retardancy, and low moisture absorption to molecular polymers. Widely used in the fields of electronic materials and optical materials that take advantage of these properties. Can be used.

  Examples of the present invention will be described below, but the present invention is not limited to the examples.

Table 1 shows the composition of crude divinylbiphenyl as a raw material. 625 g of crude divinylbiphenyl was dissolved in 625 g of toluene and cooled to 5 ° C. with stirring. After cooling, 500 g of bromine was slowly added dropwise while maintaining the reaction temperature at 5 to 20 ° C. When about half of bromine was dropped, crystals began to precipitate. Bromine was added dropwise and filtered to recover white crystals. Furthermore, recrystallization was performed twice using toluene as a solvent to obtain 114.5 g of 3,3′-di (1,2-dibromoethyl) biphenyl.
114.5 g of recrystallized and purified 3,3′-di (1,2-dibromoethyl) biphenyl and 0.3 g of tertiary butylcatechol were added to a mixed solvent of 458 g of toluene and 19.8 g of pure water, and the mixture was stirred at 80 ° C. Heated. While maintaining the reaction temperature at 80 to 90 ° C., the zinc powder was added little by little until it did not dissolve. After completion of the zinc addition, after washing three times with 1000 water, toluene was distilled off with a rotary evaporator to obtain 50.1 g of 3,3′-divinylbiphenyl having a purity of 99.0%.

625 g of the same crude divinylbiphenyl as in Example 1 was dissolved in 156 g of toluene and 156 g of n-heptane, and cooled to 5 ° C. with stirring. After cooling, 500 g of bromine was slowly added dropwise while maintaining the reaction temperature at 5 to 20 ° C. When about half of bromine was dropped, crystals began to precipitate. Bromine was added dropwise and filtered to recover white crystals. Furthermore, recrystallization was performed twice using toluene as a solvent to obtain 126.0 g of 3,3′-di (1,2-dibromoethyl) biphenyl.
Purified 3,3′-di (1,2-dibromoethyl) biphenyl (126.0 g) and tertiary butylcatechol (0.3 g) are added to a mixed solvent of 458 g of dioxane and 45.8 g of pure water and heated to 80 ° C. with stirring. did. While maintaining the reaction temperature at 80 to 90 ° C., the zinc powder was added little by little until it did not dissolve. After completion of the addition of zinc, after washing with 1000 ml of water three times, dioxane was distilled off with a rotary evaporator to obtain 55.0 g of 3,3′-divinylbiphenyl having a purity of 99.0%.

Comparative Example 1
After adding 0.5 g of tertiary butylcatechol to 500 g of the same crude divinylbiphenyl as in Example 1, distillation under reduced pressure was performed at 5 torr. However, since a polymer was generated in the distillation column and the column was clogged, distillation could not be performed.

Comparative Example 2
0.5 g of the solvent shown in Table 2 was added to 100 g of the same crude divinylbiphenyl as in Example 1 and cooled to -30 ° C. As a result, no crystal was precipitated in either case. Crude vinyl biphenyl is liquid at room temperature.

Table 3 shows the composition of crude acenaphthylene as a raw material. 500 g of crude acenaphthylene was dissolved in 500 g of toluene and cooled to 5 ° C. with stirring. After cooling, 474 g of bromine was slowly added dropwise while maintaining the reaction temperature at 5 to 10 ° C. When about half of bromine was dropped, crystals began to precipitate. After dropwise addition of bromine, filtration was performed to recover crystals. Furthermore, recrystallization was performed twice using toluene as a solvent to obtain 321 g of 1,2-dibromoacenaphthylene.
Purified 1,2-dibromoacenaphthylene (321 g) and tertiary butylcatechol (0.2 g) were added to a mixed solvent of tetrahydrofuran (321 g) and pure water (15.8 g), and the mixture was heated to 80 ° C. with stirring. While maintaining the reaction temperature at 80 to 90 ° C., the zinc powder was added little by little until it did not dissolve. After completion of the zinc addition, it was washed with 1000 ml of water three times, and then the tetrahydrofuran was distilled off by a rotary evaporator to obtain 185 g of acenaphthylene having a purity of 99.9%.

Claims (6)

In separating and producing a polycyclic aromatic vinyl compound from an oil containing a polycyclic aromatic vinyl compound, (1) an addition step of adding hydrogen halide, halogen or water as an additive to the vinyl group of the polycyclic aromatic vinyl compound , (2) purification step of purifying by recrystallization the polycyclic aromatic vinyl compound derivatives produced by addition step, and (3) removing the additional agent process the additional agent from the purified polycyclic aromatic vinyl compound derivatives eliminated A process for producing a polycyclic aromatic vinyl compound, comprising:
  The production method according to claim 1, wherein the polycyclic aromatic vinyl compound is monovinylbiphenyl and / or divinylbiphenyl.   The process according to claim 1, wherein the polycyclic aromatic vinyl compound is monovinylnaphthalene and / or divinylnaphthalene.   The process according to claim 1, wherein the polycyclic aromatic vinyl compound is acenaphthylene.   The process according to claim 1, wherein the polycyclic aromatic vinyl compound is 3,3'-divinylbiphenyl. The production method according to claim 1, wherein the polycyclic aromatic vinyl compound is 3,3'-divinylbiphenyl, and the purification method in the purification step is recrystallization.