KR20160085761A - Method for collecting bisphenol fluorene compound from resin containing fluorene structure - Google Patents

Abstract

A bisphenol fluorene is produced by hydrolyzing a polycarbonate resin having a fluorene structure in the presence of an aqueous metal hydroxide solution and the bisphenol fluorene is selectively dispersed in an organic solvent without any special operation such as acid treatment, The present invention provides a method for recovering bisphenol fluorenes, which is characterized by separating a bisphenol component or an inorganic component from a bisphenol component and an inorganic component.

Description

METHOD FOR COLLECTING BISPHENOL FLUORENE COMPOUND FROM RESIN CONTAINING FLUORENE STRUCTURE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering bisphenol fluorene from a resin containing a fluorene structure,

The present invention relates to a method for efficiently recovering bisphenol fluorene as a starting raw material from a waste polycarbonate resin having a fluorene structure with high quality. More particularly, the present invention relates to a method for recovering bisphenol fluorene obtained by hydrolyzing a polycarbonate resin having a fluorene structure in the presence of a metal hydroxide aqueous solution into an organic solvent to obtain high quality bisphenol fluorene that can be reused as an optical resin raw material .

The polycarbonate resin having a fluorene structure has a high refractive index, a low birefringence ratio, transparency, processability, and heat resistance. Therefore, recently, the amount of the optical resin material such as an optical lens or an optical film . In addition, since the amount of resin to be discarded increases with the increase in the demand of polycarbonate resin containing a fluorene structure, it has become important to reuse it. Particularly, since bisphenol fluorene, which is one of starting materials, is expensive compared to other raw materials, development of a method for efficiently recovering it as a reusable raw material has been demanded.

Examples of the method for depolymerizing the polycarbonate resin include a phenol digestion decomposition method in which a polycarbonate resin is mainly converted into bisphenol A and carbonic acid diphenyl by heating with a phenol and then separated and recovered by distillation; a polycarbonate resin and a lower alcohol There have been known three methods of an alcohol addition cracking method of converting a bisphenol A and a dialkyl carbonate into a bisphenol A and a dialkyl carbonate by a distillation method and a hydrolysis method in which a polycarbonate resin is reacted with an excess alkali aqueous solution and decomposed and recovered into bisphenol A , The phenol digestion decomposition method and the alcohol digestion decomposition method generate by-products such as diphenyl carbonate or dialkyl carbonate, and the process of separating and recovering the desired bisphenols becomes complicated.

As a method for depolymerizing a polycarbonate resin by hydrolysis, polycarbonate and an alkali aqueous solution of 1 to 30% are placed in a pressure-resistant container in Japanese Patent Publication No. 40-16536 (Patent Document 1) , Preferably 150 DEG C or higher, the alkali aqueous solution containing the decomposition product is made acidic, the decomposed product is precipitated and filtered, dissolved in methanol, treated with activated charcoal to remove the coloring component, and then precipitated again to obtain white bisphenol Is obtained. Japanese Patent Application Laid-Open No. 54-48869 (Patent Document 2) discloses a method in which a 15N aqueous solution of sodium hydroxide is added to polycarbonate to saponify at 100 ° C to separate the un-saponified component, and the saponified mixture is phosgenated to be subjected to polycarbonate polymerization A method of using the same is disclosed. Japanese Patent Application Laid-Open No. 2005-126358 (Patent Document 3) discloses a method in which a part or all of a waste aromatic polycarbonate resin is dissolved in an organic solvent consisting of a chlorinated compound, and then decomposed into a metal hydroxide aqueous solution. Water is added to the decomposed solution, There is disclosed a method of dissolving a solid component to separate an aqueous phase from an organic solvent phase and recovering the aqueous phase to obtain an aromatic dihydroxy compound metal salt aqueous solution. Japanese Patent Application Laid-Open No. 2005-162675 (Patent Document 4) discloses an aromatic dihydroxy compound metal salt aqueous solution obtained in the same manner as in Patent Document 3 by adding an acid to precipitate an aromatic dihydroxy compound, followed by filtration and washing, A method for obtaining a dihydroxy compound solid is disclosed.

However, the methods of Patent Document 1 and Patent Document 2 require severe reaction conditions such as high temperature and / or high pressure, and a large amount of water is used in the post-treatment, and the operation requiring reprecipitation operation is troublesome. In addition, in the method of Patent Document 2, the decomposition product is reused in the polymerization reaction of the resin without refining operation, so that the additives and the coloring agent are intact into the resin and affect the product quality. In the methods of Patent Documents 3 and 4, an organic solvent composed of a chlorinated compound such as methylene chloride is used to dissolve the polycarbonate resin, and there is a concern about safety and adverse effects on the environment. Do. In addition, in the methods of Patent Documents 3 and 4, since acid treatment is required to extract the crystals of the aromatic dihydroxy compound, the operation is troublesome and the amount of waste increases. In the conventional methods described in Patent Documents 1 to 4, all bisphenols are recovered as a metal salt aqueous solution of bisphenols in water phase, and acid treatment is required to extract them as crystals.

In addition, the conventional method described above is a suitable depolymerization method for recovering bisphenol A from a polycarbonate derived from 2,2-bis (4-hydroxyphenyl) propane (commonly referred to as bisphenol A) It was necessary to develop a preferable method for recovering bisphenol fluorene having a specific structure from a carbonate resin.

Japanese Patent Publication No. 40-16536 (public announcement: July 29, 1965) Japanese Patent Application Laid-Open No. 54-48869 (published on Apr. 17, 1979) Japanese Patent Application Laid-Open No. 2005-126358 (Disclosure Date: May 19, 2005) Japanese Patent Application Laid-Open No. 2005-162675 (Disclosure Date: June 23, 2005)

An object of the present invention is to provide a method for efficiently recovering highly pure bisphenol fluorenes which can be reused as a raw material for optical resins from a waste polycarbonate resin having a fluorene structure.

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted intensive studies in order to solve the above problems, and as a result, they have found that a polycarbonate resin having a fluorene structure is hydrolyzed in the presence of a metal hydroxide aqueous solution to produce bisphenol fluorene, The bisphenol fluorenes which can be separated into other bisphenol components or inorganic components by selectively distributing the bisphenol fluorenes in an organic solvent as they are without any special operation such as acid treatment can be simplified and the waste reduction and purification operations can be simplified, And recovered crystals of fluorenes. Further, the recovered bisphenol fluorenes were found to be useful as raw materials for optical resins due to their high purity and good hue, and they completed the present invention.

That is, the present invention includes the following.

[One]

Hydrolyzing a polycarbonate resin having a fluorene structure in the presence of an aqueous metal hydroxide solution to produce a bisphenol fluorene, dispersing the bisphenol fluorene produced by the hydrolysis in an organic solvent, Separating the phase of the bisphenol fluorene from the phase of the metal hydroxide aqueous solution and recovering the bisphenol fluorenes in the phase of the organic solvent.

[2]

The method for recovering bisphenol fluorenes according to [1], wherein the organic solvent in which the bisphenol fluorenes are collected and recovered is at least one selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons.

[3]

The method for recovering bisphenol fluorenes according to [1] or [2], wherein the bisphenol fluorene is 9,9-bis (hydroxyalkoxyphenyl) fluorene.

[4]

The method for recovering bisphenol fluorenes according to [3], wherein the 9,9-bis (hydroxyalkoxyphenyl) fluorene is a compound represented by the following general formula (1).

[Chemical Formula 1]

(Wherein, R _1a and R _1b represents an alkylene group, which may be the same or different. R _2a and R _2b denotes an alkyl group, a cycloalkyl group, an alkoxy group or an aryl group, which may be the same or different. N ₁ and n ₂ represent an integer of 1 or more and may be the same or different. M ₁ and m ₂ represent 0 or an integer of 1 to 4, and may be the same or different.)

[5]

The method for recovering bisphenol fluorenes according to any one of [1] to [4], wherein the bisphenol fluorene is 9,9-bis (4- (2-hydroxyethoxy) .

[6]

The bisphenol fluorene compound according to any one of [1] to [5], wherein the bisphenol fluorene is recovered in the upper half of the organic solvent, and crystals of the bisphenol fluorene are obtained by crystallization from the upper half of the organic solvent. Method of recovery of oranges.

According to the present invention, it is possible to efficiently recover high quality bisphenol fluorenes that can be reused as raw materials for optical resins from polycarbonate resins having a fluorene structure. The present invention has a remarkable industrial effect.

Hereinafter, the present invention will be described in detail.

In the present invention, the polycarbonate resin having a fluorene structure is produced by a known method such as an interfacial polymerization method or a melt polymerization method using bisphenol fluorene as a constituent raw material, and may include additives such as a terminal sealing agent and a stabilizer And is interpreted in the broadest sense. Examples of the polycarbonate resin to be subjected to the depolymerization method of the present invention include polycarbonate resins alone or resins containing other components such as polyester carbonates, resins combined with other components A composition such as a mixture of polycarbonate and polyester, and the like. The shape thereof is not limited to powder, pellet, sheet, film, molded product, etc., but may be a discarded lens, a sheet, a defective product, a burr generated during manufacturing and / Solids recovered from the waste of the used product, such milled material, etc. are used.

Examples of bisphenol fluorenes which are constituent raw materials of the polycarbonate resin of the present invention and recovered by the method of the present invention include 9,9-bis (hydroxyphenyl) fluorene, 9,9-bis 9 (9) -bis (alkoxyhydroxyphenyl) fluorene, 9,9-bis (cycloalkylhydroxyphenyl) fluorene, (Hydroxyalkoxyphenyl) fluorene, 9,9-bis (hydroxyalkoxyphenyl) fluorene, 9,9-bis (hydroxyphenyl) fluorene, 9,9-bis (hydroxyalkoxy-alkoxyphenyl) fluorene, such as 9,9-bis (hydroxyalkoxy-arylphenyl) fluorene, Hydroxyalkoxyphenyl) fluorenes, and the like. Is preferably a 9,9-bis (hydroxyalkoxyphenyl) fluorene, and more preferably a 9,9-bis (hydroxyalkoxyphenyl) fluorene represented by the above general formula (1).

In the above general formula (1), R _1a and R _1b represent an alkylene group, which may be the same or different. R _2a and R _2b represent an alkyl group, a cycloalkyl group, an aryl group or an alkoxy group, which may be the same or different. n ₁ and n ₂ represent an integer of 1 or more and may be the same or different. m ₁ and m ₂ represent 0 or an integer of 1 to 4, and may be the same or different

The alkylene group represented by R _1a or R _1b may be a straight chain or branched chain and includes, for example, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group and a hexamethylene group . The alkylene group represented by R _1a or R _1b is preferably a straight chain or branched chain alkylene group having 2 to 6 carbon atoms, more preferably a straight or branched alkylene group having 2 to 4 carbon atoms, Or a straight chain or branched chain alkylene group having 3 or more carbon atoms. R _1a and R _1b may be composed of the same alkylene group and may be composed of different alkylene groups, respectively.

Examples of the alkyl group for R _2a or R _2b include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, a pentyl group, Or a straight chain or branched chain alkyl group having 1 to 20 carbon atoms. The alkyl group is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, still more preferably a linear or branched alkyl group having 1 to 3 carbon atoms Alkyl group.

Examples of the cycloalkyl group as R _2a or R _2b include a cyclopentyl group, a cyclohexyl group, an alkyl (for example, an alkyl of 1 to 4 carbon atoms) substituted cyclopentyl group, an alkyl (for example, Cycloalkyl group having 4 to 16 (preferably 5 to 8 carbon atoms) carbon atoms or an alkyl-substituted cycloalkyl group such as a substituted cyclohexyl group). The cycloalkyl group is more preferably a cyclopentyl group or a cyclohexyl group.

As the aryl group for R _2a or R _2b , for example, a phenyl group, an alkyl (for example, an alkyl having 1 to 4 carbon atoms) substituted phenyl group or a naphthyl group can be given. The aryl group is preferably a phenyl group or an alkyl-substituted phenyl group (for example, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, etc.), and more preferably a phenyl group.

The alkoxy group for R _2a or R _2b is preferably a linear or branched alkoxy group having 1 to 6 carbon atoms, more preferably a linear or branched alkoxy group having 1 to 3 carbon atoms, for example, a methoxy group , Ethoxy group, and propoxy group.

The alkyl group, cycloalkyl group and aryl group may have a substituent other than the alkyl group (for example, an alkoxy group, an acyl group, a halogen atom, etc.).

N ₁ and n ₂ each representing the number of repeating _units of OR _1a and OR _1b are preferably an integer of 1 to 3, more preferably 1 or 2, and typically 1. N ₁ and n ₂ are typically the same.

M ₁ and m ₂ each representing the substitution number of R _2a and R _2b are preferably an integer of 0 to 2, more preferably 0 or 1, and typically 0. Also, m ₁ and m ₂ are typically the same.

Specific examples of the 9,9-bis (hydroxyalkoxyphenyl) fluorenes represented by the above general formula (1) include 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) Bis [3- (2-hydroxyethoxy) -6-methylphenyl] fluorene, 9,9-bis [3- (2-hydroxyethoxy) 9,9-bis [2- (2-hydroxyethoxy) -4-ethylphenyl] fluorene, 9,9-bis [2- (2-hydroxyethoxy) -Bis [4- (2-hydroxydiethoxy) -3-methylphenyl] fluorene, 9,9-bis Dimethylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -2,6-dimethylphenyl] fluorene, Bis [4- (2-hydroxyethoxy) -3,5-di-t-butylphenyl] fluorene, 9,9- (3-cyclohexylphenyl) fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-methoxyphenyl] fluorene, and the like. These bisphenol fluorenes may be used singly or in a mixture of two or more. Of these bisphenol fluorenes, 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, which has many applications as an optical resin material, is particularly preferable.

The polycarbonate resin of the present invention contains bisphenol fluorene as a main component, but other diol component may be included as a constituent raw material. Other diol components may be used alone or in combination of two or more.

Specific examples of other diol components include alkylene glycols such as ethylene glycol, propylene glycol, 1,3-butanediol, neopentyl glycol and the like; alicyclic diols [for example, cyclohexanediol, cyclohexanedimethanol , 4,4'-diaminodiphenylmethane diisocyanate, tricyclodecane dimethanol, adamantanediol, norbornanediol, 2,2-bis (4-hydroxycyclohexyl) propane, isosorbide, Dihydroxydiphenyl, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) Bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) propane, (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenyl sulfone, 4, 5-trimethylcyclohexane, 4'-dihydroxydiphenyl ether etc.] and the like.

In the present invention, a decomposition reaction (hydrolysis reaction) of a polycarbonate resin is performed in the presence of a metal hydroxide aqueous solution. As the metal hydroxide to be used, a hydroxide of an alkali metal or an alkaline earth metal is preferably used, and a hydroxide of an alkali metal is more preferable. More specifically, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide and the like are used, and sodium hydroxide or potassium hydroxide is preferable, and sodium hydroxide is particularly preferable. These metal hydroxides can be used either singly or as a mixture of two or more kinds.

The temperature at which the decomposition reaction is carried out is not particularly limited, but is usually 120 ° C or lower, preferably 100 ° C or lower, more preferably 30 ° C to 90 ° C. When the temperature is 120 ° C or lower, it is preferable that the reaction liquid is not colored in brown during the decomposition treatment. When the reaction solution is colored, the color of the bisphenol fluorene tends to deteriorate or the purity thereof tends to be lowered due to the influence thereof, so that the bisphenol fluorene having good quality may not be recovered. In addition, when the temperature becomes high (more than 120 ° C), a large amount of heating energy is required. Since the reaction at the boiling point requires a pressure vessel, It is economically advantageous. In addition, when the temperature is too low, the decomposition reaction time is prolonged, and the treatment efficiency may be significantly lowered.

The amount of the metal hydroxide to be used is preferably from 2.0 to 8.0 moles per mole of the carbonate bond of the polycarbonate resin. Normally, when depolymerizing a polycarbonate resin containing bisphenol A as a main constituent material, 4.1 mol or more of metal hydroxide is used relative to 1 mol of the carbonate bond, but in the present invention, since bisphenol fluorene is not recovered as a metal salt aqueous solution , And 4.0 mol or less. If the amount of the metal hydroxide to be used is 2.0 mol or more, the decomposition reaction is not too slow and the decomposition is sufficiently carried out. On the other hand, if it is 8.0 mole or less, the cost can be reduced, and the amount of water required for washing and purification is not much, which is economically advantageous.

The metal hydroxide is used in the form of an aqueous solution. The concentration of the metal hydroxide is preferably 10 wt% to 55 wt%, more preferably 20 wt% to 50 wt%. When the concentration of the metal hydroxide is 10% by weight or more, the decomposition rate of the polycarbonate resin is not slow. When the concentration of the metal hydroxide is 55% by weight or less, the alkali metal hydroxide precipitates and the metal hydroxide aqueous solution is difficult to slurry desirable. When the metal hydroxide aqueous solution is a slurry, the rate of the decomposition reaction of the polycarbonate resin is lowered. When the concentration of the metal hydroxide is 55% by weight or less, coloring and generation of impurities are unlikely to occur, and the quality of the recovered bisphenol fluorene is excellent, which is preferable.

The decomposition reaction of the polycarbonate resin can be carried out in the presence of at least one organic solvent selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons. By carrying out the decomposition reaction of the polycarbonate resin in the presence of the organic solvent, the rate of decomposition reaction of the polycarbonate resin is improved and decomposition of the polycarbonate resin is possible at a lower temperature than in the case of not using the organic solvent . Usually, when decomposing a polycarbonate resin containing bisphenol A as a main constituent material, an organic solvent composed of chlorinated compounds such as methylene chloride, which is both of the polycarbonate resins, is used, but surprisingly, in the present invention, It has been found that the decomposition reaction of the polycarbonate resin can be performed more easily by using an aromatic hydrocarbon or an aliphatic hydrocarbon as a solvent. Therefore, the decomposition reaction of the polycarbonate resin is preferably carried out in the presence of at least one organic solvent selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons. In the present invention, a solvent other than the solvent (for example, phenol or methanol) which reacts with the polycarbonate resin may be used in combination as long as the effect of the present invention is not impaired.

Examples of the aromatic hydrocarbon or aliphatic hydrocarbon used as a solvent for the decomposition reaction of the polycarbonate resin include, but are not limited to, toluene, xylene, mesitylene, pentane, hexane, heptane, octane, nonane, decane, cyclohexane, Decane and the like. These organic solvents may be used alone or in combination of two or more. Particularly preferred is toluene or xylene.

The amount of the organic solvent used when the at least one organic solvent selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons is used as a solvent for the decomposition reaction of the polycarbonate resin is preferably 40 to 2000 parts by weight per 100 parts by weight of the polycarbonate resin , More preferably in the range of 100 to 1000 parts by weight. When the amount of the organic solvent used is 40 parts by weight or more, the aromatic polycarbonate resin is preferably dissolved sufficiently to reduce the amount of the insoluble portion and increase the yield. When the amount of the organic solvent to be used is 2000 parts by weight or less, it is preferable because the decomposition reaction time can be shortened and the recovery cost of the solvent can be suppressed by suppressing the decomposition rate in the decomposition reaction from being lowered.

In the present invention, the bisphenol fluorenes produced by the hydrolysis of the polycarbonate resin are directly recovered in the organic solvent without any special treatment such as acid treatment (neutralization). In this case, other bisphenol components can also be recovered in the organic solvent. However, since other bisphenols, typically represented by bisphenol A, are recovered as an aqueous solution of a metal salt in water phase, bisphenol fluorene is selectively recovered in an organic solvent can do. In addition, by separating the organic solvent phase and water phase, desired bisphenol fluorene can be easily recovered.

As the organic solvent used for the recovery of bisphenol fluorene, it is possible to dissolve bisphenol fluorene without reacting with polycarbonate resin or decomposition product, and it may be any organic solvent capable of separating from water. It may be more than two kinds. Among these organic solvents, at least one selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons is preferable. Examples of such an organic solvent include toluene, xylene, mesitylene, pentane, hexane, heptane, octane, nonane, decane, cyclohexane, cyclodecane and the like. These organic solvents may be used alone or in combination of two or more. Particularly preferred is toluene or xylene.

The organic solvent may be added after the hydrolysis reaction of the polycarbonate resin to recover the bisphenol fluorene dissolved in the organic solvent. Further, as described above, it is also possible to carry out a hydrolysis reaction in the presence of an organic solvent by adding an organic solvent in advance of the decomposition reaction of the polycarbonate resin, and to recover the bisphenol fluorene produced by dissolving it occasionally. The decomposition reaction of the polycarbonate resin in the presence of the organic solvent improves the rate of the decomposition reaction of the polycarbonate resin compared with the case where the organic solvent is not used and the polycarbonate resin can be decomposed at a lower temperature, Preferably, the decomposition reaction of the polycarbonate resin is carried out in the presence of an organic solvent, and the resulting bisphenol fluorene is often dissolved in an organic solvent and recovered.

The amount of the organic solvent used for recovering the bisphenol fluorenes is preferably in the range of 40 to 2000 parts by weight, more preferably 100 to 1000 parts by weight, based on 100 parts by weight of the polycarbonate resin. When the amount of the organic solvent used is 40 parts by weight or more, the aromatic polycarbonate resin can be sufficiently dissolved, thereby reducing the amount of the insoluble portion and increasing the yield. When the amount of the organic solvent used is 2000 parts by weight or less, it is preferable because the volume efficiency can be inhibited from being lowered and the increase in the recovery cost of the solvent can be suppressed.

In the present invention, an organic solvent phase containing recovered bisphenol fluorenes is subjected to purifying operations such as washing and adsorption, if necessary, and crystals are then precipitated by crystallization or the like to obtain crystals of bisphenol fluorene Can be obtained. The precipitated crystals can be recovered by filtration, and the crystals can be subjected to purifying operations such as washing and refining as necessary.

The crystals of bisphenol fluorene thus recovered are excellent in color and purity and are preferably used as raw materials for polycarbonate for optical resins.

<Examples>

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

The measured values of bisphenol fluorene and polycarbonate were measured in accordance with the following methods and measurement conditions.

[1] HPLC purity

The area percentage value of each component when HPLC measurement was carried out under the following measurement conditions was defined as HPLC purity.

· Device: "LC-2010AHT" made by Shimadzu Corporation

· Column: "L-column ODS" by Chemical Evaluation Research Organization, General Foundation

(5 占 퐉, 4.6 mm? 250 mm)

· Column temperature: 40 ° C

Detection wavelength: UV 254 nm

· Mobile phase: liquid A = water, liquid B = acetonitrile

· Flow rate of mobile phase: 1.0 ml / min

· Slope of mobile phase: B liquid concentration: 30% (0 minutes) → 100% (after 25 minutes) → 100% (after 35 minutes)

[2] Melting point and glass transition temperature

The melting point and the glass transition temperature were measured using a differential scanning calorimeter (&quot; EXSTAR DSC 7020 &quot; manufactured by SII ANA NanoTechnology Co., Ltd.) at a heating rate of 10 캜 / min.

[3] Molecular weight and yield of decomposition products of polycarbonate resin

The weight average molecular weight of the polycarbonate resin was measured with a RI (differential refractive index) detector (in terms of polystyrene) using a high-speed GPC apparatus (HLC-8200 GPC, mobile phase: THF).

Further, the area percentage value when the GPC measurement of the reaction solution was carried out under the above-mentioned measurement conditions was made as the production rate of each component and the dimer.

(Synthesis Example 1)

20.00 parts by weight of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (HPLC purity 98.7%, melting point 161 캜), 10.10 parts by weight of diphenyl carbonate, and sodium hydrogen carbonate 2.2 × 10 ^-5 parts by weight of a stirrer and an outlet (留出) into a device attached to the reaction vessel and heated to 200 ℃ in a nitrogen atmosphere, was completely melted, subjected to stirring for 20 minutes. Thereafter, the reduced pressure degree in the reaction vessel was adjusted to 27 kPa, and the mixture was stirred at 200 占 폚 for 40 minutes, at 210 占 폚 for 40 minutes, and at 220 占 폚 for 50 minutes. Subsequently, the mixture was stirred at 24 kPa, 230 DEG C for 30 minutes, 20 kPa and 240 DEG C for 50 minutes while adjusting the decompression degree and temperature, and then the pressure reduction degree in the reaction vessel was set to 133 Pa or less over 1 hour, (Weight average molecular weight: 28000, glass transition temperature: 152 占 폚). The polycarbonate resin was taken out and pulverized with a mortar to obtain an amorphous solid.

(Synthesis Example 2)

18.09 parts by weight of 9,9-bis [2- (2-hydroxyethoxy) -4-methylphenyl] fluorene (HPLC purity: 99.0%, melting point: 172 ° C), 8.60 parts by weight of diphenyl carbonate, 2.0 × 10 ^-5 parts by weight were placed in a reaction container equipped with a stirrer and an outlet device and heated at 200 ° C. under a nitrogen atmosphere and stirred for 20 minutes to be completely melted. Thereafter, the degree of vacuum in the reaction vessel was adjusted to 27 kPa, and the mixture was stirred at 200 占 폚 for 30 minutes, at 210 占 폚 for 50 minutes, and at 220 占 폚 for 30 minutes. Subsequently, the mixture was stirred at 24 kPa, 230 DEG C for 30 minutes, 20 kPa and 240 DEG C for 50 minutes while adjusting the decompression degree and temperature, and then the pressure reduction degree in the reaction vessel was set to 133 Pa or less over 1 hour, (Weight average molecular weight: 27500, glass transition temperature: 159 占 폚). The polycarbonate resin was taken out and pulverized with a mortar to obtain an amorphous solid.

(Example 1)

100 parts by weight of the solid polycarbonate resin obtained in Synthesis Example 1, 97 parts by weight of a 48% aqueous solution of sodium hydroxide and 600 parts by weight of toluene were placed in a reactor equipped with a stirrer, a condenser and a thermometer, followed by heating and stirring at 80 占 폚 for 2 hours. Analysis of the reaction solution by GPC showed that the high molecular weight material disappeared, 99.4% was decomposed into 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, and 0.6% was decomposed into its dimer. Subsequently, after the reaction solution was allowed to stand, the aqueous phase was separated and removed to obtain a toluene solution phase. This toluene solution was analyzed by HPLC to find that 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene was detected, and the objective 9,9-bis [4- -Hydroxyethoxy) phenyl] fluorene was recovered. Further, the toluene solvent was washed with water four times to remove the inorganic matter, and then the obtained toluene solvent was cooled to room temperature. The precipitated crystals were filtered and dried to obtain 78 parts by weight of a white crystal of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene. This white crystal had an HPLC purity of 99.0% and a melting point of 161 캜.

(Example 2)

100 parts by weight of the polycarbonate resin solid obtained in Synthesis Example 2, 60 parts by weight of 48% aqueous sodium hydroxide solution and 300 parts by weight of xylene were placed in a reactor equipped with a stirrer, a condenser and a thermometer, and the mixture was heated and reacted at 80 DEG C for 2 hours. Analysis of the reaction solution by GPC showed that the high molecular weight water disappeared, 99.7% was added to 9,9-bis [2- (2-hydroxyethoxy) -4-methylphenyl] fluorene, 0.3% It was disassembled. Subsequently, the reaction solution was allowed to stand, and the water phase was separated and removed to obtain a xylene solution phase. This xylene solution was analyzed by HPLC to find that 9,9-bis [2- (2-hydroxyethoxy) -4-methylphenyl] fluorene was detected and the desired 9,9-bis [2 - (2-hydroxyethoxy) -4-methylphenyl] fluorene was recovered. Further, the xylene solvent phase was washed with water four times to remove the inorganic matter. Subsequently, the resulting xylene solvent phase was filtered and then cooled to room temperature. Precipitated crystals were filtered and dried to obtain 82 parts by weight of 9,9-bis [2- (2-hydroxyethoxy) -4-methylphenyl] fluorene white crystals. This white crystal had an HPLC purity of 99.1% and a melting point of 172 캜.

(Example 3)

In Example 1, the same operation was carried out except that 97 parts by weight of 48% aqueous sodium hydroxide solution was replaced with 150 parts by weight of 24% sodium hydroxide aqueous solution, and toluene was replaced by octane and the reaction temperature was changed to 90 캜, and the reaction was carried out for 5 hours. Analysis of the reaction mixture by GPC showed that the high molecular weight water disappeared, 99.2% was decomposed into 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, 0. 8% . Subsequently, after the reaction solution was allowed to stand, the aqueous phase was separated and removed to obtain an octane solution phase. This octane solution was analyzed by HPLC and 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene was detected and the desired 9,9-bis [4- Hydroxy] ethoxy) phenyl] fluorene was recovered. Further, the octane solvent was washed with water four times to remove the inorganic matter, and the obtained octane solvent was cooled to room temperature. The precipitated crystals were filtered and dried to obtain 76 parts by weight of a white crystal of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene. This white crystal had an HPLC purity of 98.9% and a melting point of 161 ° C.

(Example 4)

A polycarbonate resin containing 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) 170 parts by weight of a resin obtained by pulverizing waste materials generated in the production of the molded product, pellet-shaped waste, 82 parts by weight of a 48% aqueous solution of sodium hydroxide and 391 parts by weight of toluene were charged and reacted at 80 DEG C for 2 hours. Analysis of the reaction mixture by GPC showed that the high molecular weight material was lost, 99.5% was added to 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and bisphenol A, 0.5% It was disintegrated in the body. Subsequently, the reaction solution was allowed to stand, and the water phase was separated and removed to obtain a toluene solution phase. The purity of the 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene except for toluene was 97.9%, and the desired 9,9- It was confirmed that bis [4- (2-hydroxyethoxy) phenyl] fluorene was recovered. Further, acid was added to the separated water phase, and the precipitated crystals were separated by filtration and analyzed. As a result, bisphenol A was obtained. The obtained toluene solvent was washed with water four times to remove inorganic matter, and dehydrated under reflux in toluene. Subsequently, the toluene solvent phase was filtered to remove insolubles, and then cooled to room temperature. The precipitated crystals were filtered and dried to obtain 124 parts by weight of a white crystal of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene. This white crystal had an HPLC purity of 98.9% and a melting point of 161 ° C.

(Example 5)

170 parts of a recovered product obtained by pulverizing a discarded film in a polycarbonate resin raw material containing 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and isosorbide as starting materials, 82 parts by weight of a 48% aqueous solution of sodium hydroxide and 391 parts by weight of toluene were charged and stirred at 80 캜 for 2 hours. Analysis of the reaction solution by GPC showed that the high molecular weight water was lost, 99.5% was added to 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and isosorbide, 0.5% It was disintegrated in the body. Subsequently, after the reaction solution was allowed to stand, the aqueous phase was separated and removed to obtain a toluene solution phase. Analysis of this toluene solution by HPLC showed that the purity of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene excluding toluene was 98.3%, and the desired 9,9- It was confirmed that bis [4- (2-hydroxyethoxy) phenyl] fluorene was recovered. Further, the organic layer was washed with water four times to remove the inorganic component and isosorbide. Subsequently, the toluene solvent was dehydrated under reflux. Subsequently, the toluene solvent phase was filtered to remove insolubles, and then cooled to room temperature. The precipitated crystals were filtered and dried to obtain 107 parts by weight of a white crystal of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene. This white crystal had an HPLC purity of 97.4% and a melting point of 160 캜.

(Example 6)

20.00 parts by weight of a recovered product obtained by pulverizing a commercially available special polyester carbonate resin having 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and terephthalic acid as a main skeleton in a pellet form, 48% 14.10 parts by weight of sodium aqueous solution and 46.00 parts by weight of toluene were placed, and the mixture was heated and stirred at 88 占 폚 for reaction for 5 hours. Analysis of the reaction solution by GPC showed that the high molecular weight material disappeared, 99.9% of which was added to 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and terephthalic acid, 0.1% . Subsequently, after the reaction solution was allowed to stand, the aqueous phase was separated and removed to obtain a toluene solution phase. Analysis of this toluene solution by HPLC showed that the purity of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene except for toluene was 97.0%, and the desired 9,9- It was confirmed that bis [4- (2-hydroxyethoxy) phenyl] fluorene was recovered. The obtained toluene solvent was washed with water four times to remove the inorganic component and terephthalic acid, followed by dehydration under reflux in toluene. Subsequently, the toluene solvent phase was filtered to remove insolubles, and then cooled to room temperature. The precipitated crystals were filtered and dried to obtain 16.30 parts by weight of a white crystal of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene. This white crystal had an HPLC purity of 98.7% and a melting point of 160 캜.

(Example 7)

A commercially available special polycarbonate resin having 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) , 78 parts by weight of a 48% aqueous solution of sodium hydroxide and 900 parts by weight of toluene were charged, and the mixture was heated and reacted at 90 DEG C for 2 hours. Analysis of the reaction mixture by GPC showed that the high molecular weight water disappeared and 99.5% was decomposed into 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and bisphenol A and 0.5% there was. Subsequently, after the reaction solution was allowed to stand, the aqueous phase was separated and removed to obtain a toluene solution phase. Analysis of this toluene solution by HPLC showed that the purity of 9,9-bis (4-hydroxy-3-methylphenyl) fluorene except for toluene was 98.0%, and the desired 9,9-bis -Hydroxy-3-methylphenyl) fluorene was recovered. The obtained toluene solvent was washed with water four times to remove the inorganic matter, and dehydrated under reflux in toluene solvent. Subsequently, the toluene solvent phase was filtered to remove insolubles, and then cooled to room temperature. The precipitated crystals were filtered and dried to obtain 39 parts by weight of white crystals of 9,9-bis (4-hydroxy-3-methylphenyl) fluorene. The HPLC purity of this white crystal was 98.3% and a melting point of 222 캜.

The bisphenol fluorenes recovered by the method according to the present invention are bisphenol fluorenes of high purity and high quality that can be reused as raw materials for optical resins.

Therefore, by using the recovery method of bisphenol fluorene according to the present invention, it is possible to efficiently recover bisphenol fluorene of high purity and high quality which can be reused as a raw material for optical resin from waste polycarbonate resin having fluorene structure .

Claims (6)

Hydrolyzing a polycarbonate resin having a fluorene structure in the presence of an aqueous metal hydroxide solution to produce a bisphenol fluorene, dispersing the bisphenol fluorene produced by the hydrolysis in an organic solvent, And the phase of the metal hydroxide aqueous solution are separated to recover the bisphenol fluorenes in the upper half of the organic solvent. The method according to claim 1,
The method for recovering bisphenol fluorenes according to claim 1, wherein the organic solvent for recovering and recovering the bisphenol fluorenes is at least one selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons. 3. The method according to claim 1 or 2,
Wherein the bisphenol fluorenes are 9,9-bis (hydroxyalkoxyphenyl) fluorenes. The method of claim 3,
Wherein the 9,9-bis (hydroxyalkoxyphenyl) fluorene is a compound represented by the following general formula (1).
[Chemical Formula 1]

(Wherein, R _1a and R _1b represents an alkylene group, which may be the same or different. R _2a and R _2b denotes an alkyl group, a cycloalkyl group, an alkoxy group or an aryl group, which may be the same or different. N ₁ and n ₂ represent integers of 1 or more, and may be the same or different. M ₁ and m ₂ represent 0 or an integer of 1 to 4, and may be the same or different.) 5. The method according to any one of claims 1 to 4,
Wherein the bisphenol fluorene is 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene. 6. The method according to any one of claims 1 to 5,
Recovering the bisphenol fluorene in the upper half of the organic solvent, and crystallizing the bisphenol fluorene from the upper half of the organic solvent by crystallization.