Method for recovering alcohol compound having fluorene skeleton

Abstract

To provide a method for selectively recovering a compound represented by the formula (1) from a mixture including the compound represented by the formula (1) and a compound represented by the formula (2).SOLUTION: A mixture is prepared that includes crystals and solution, the mixture including a compound represented by the formula (1), a compound represented by the formula (2), an aromatic hydrocarbon and a C1-6 aliphatic alcohol in specific proportions. From the mixture, crystals are separated, which can solve the problem herein.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a mixture for selectively recovering an alcohol compound having a fluorene skeleton from a mixture containing an alcohol compound having a fluorene skeleton and an alcohol compound having a binaphthalene skeleton, and a recovery method.

Background Art

[0002] In recent years, polycarbonate resins having a fluorene structure have been increasingly used as optical resin materials such as optical lenses and optical films because they are relatively excellent in high refractive index, low birefringence, transparency, processability, and heat resistance. Among them, the following formula (1):

[0003]

Chemical Formula

[0004]

Chemical Formula

[0005] On the other hand, with the increasing demand for the polycarbonate resin, the amount of resin to be discarded has also increased, so it has become important to recycle them. As methods for recycling waste resins, for example, methods such as heating and melting the waste resin for use, and depolymerizing the waste resin into monomers and then polymerizing the monomers again can be considered. From the viewpoint of obtaining high-quality resins, the latter method is desirable.

[0006] Therefore, the applicants of the present application proposed a method for depolymerizing a polycarbonate resin using an alcohol compound having a fluorene skeleton containing the compound represented by the above formula (1) as a raw material (Patent Document 2).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] When the inventors of the present application carried out the depolymerization of a polycarbonate resin having a structural unit derived from the compound represented by the above formula (1) and the compound represented by the above formula (2) described in Patent Document 1 according to the method described in Patent Document 2, since the depolymerization proceeded as described in Patent Document 2, it was found that a method for selectively recovering the compound represented by the above formula (1), which is the main component, from the depolymerized product containing the compound represented by the above formula (1) and the compound represented by the above formula (2) was necessary.

[0009] An object of the present invention is to provide a method for selectively recovering the compound represented by the above formula (1) from a mixture containing the compound represented by the above formula (1) and the compound represented by the above formula (2).

Means for Solving the Problems

[0010] The inventors of the present invention prepared a mixture containing crystals and a solution, which contains the compound represented by the above formula (1), the compound represented by the above formula (2), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms in a specific ratio (hereinafter, sometimes referred to as "the mixture of the present invention"), and found that the above problems can be solved by separating the crystals from the mixture. Specifically, it includes the following inventions.

[0011] [1] A mixture containing crystals and a solution, The following formula (1):

[0012] [Chemical formula] A compound represented by the following formula (1):

[0013] [Chemical formula] A mixture containing a compound represented by the formula (2), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms, wherein the ratio of the compound represented by the formula (1) is 50% by weight or more with respect to the total amount of the compound represented by the formula (1) and the compound represented by the formula (2), and the ratio of the aromatic hydrocarbons is 5 to 95% by weight with respect to the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms.

[0014] [2] The mixture according to [1], wherein the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms is 40 to 2000 parts by weight with respect to 100 parts by weight of the total amount of the compound represented by the formula (1) and the compound represented by the formula (2).

[0015] [3] A solution for producing the mixture according to [1] or [2], which contains the compound represented by the formula (1), the compound represented by the formula (2), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms, wherein the ratio of the compound represented by the formula (1) is 50% by weight or more with respect to the total amount of the compound represented by the formula (1) and the compound represented by the formula (2), and the ratio of the aromatic hydrocarbons is 5 to 95% by weight with respect to the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms.

[0016] [3] A method for producing the mixture according to [1] or [2], which includes a step of precipitating crystals from the solution according to [3].

[0017] [4] A method for recovering crystals of a compound represented by formula (1) by separating crystals from the mixture described in [1] or [2].

Advantages of the Invention

[0018] According to the present invention, the compound represented by the above formula (1) can be selectively recovered from a mixture containing the compound represented by the above formula (1) and the compound represented by the above formula (2). In particular, even in a mixture containing a considerable amount of the compound represented by the above formula (2) together with the compound represented by the above formula (1) (for example, containing 10 to 50% by weight of the compound represented by the above formula (2) based on the total amount of the compound represented by the above formula (1) and the compound represented by the above formula (2)), it is possible to selectively recover the compound represented by the above formula (1). Further, by performing a further purification operation (for example, performing recrystallization after concentration, etc.) on the filtrate obtained after separating and recovering crystals from the mixture of the present invention, since the filtrate contains a large amount of the compound represented by the above formula (2), it is also possible to selectively recover the compound represented by the above formula (2).

Embodiments for Carrying Out the Invention

[0019] The method for selectively recovering the compound represented by the above formula (1) of the present invention is a mixture containing crystals and a solution, and a mixture containing the compound represented by the above formula (1), the compound represented by the above formula (2), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms in specific ratios is prepared, and crystals are separated and recovered from the mixture (hereinafter, may also be referred to as the "recovery step"). Hereinafter, the method for selectively recovering the compound represented by the above formula (1) of the present invention will be described in detail.

[0020] <The mixture of the present invention> In the mixture of the present invention, the ratio of the compound represented by the above formula (1) to the total amount of the compound represented by the above formula (1) and the compound represented by the above formula (2) is 50% by weight or more, for example, 50 to 99% by weight, and from the viewpoint of more remarkably expressing the effects of the present invention, it is preferably 50 to 90% by weight. When it is necessary to confirm the amounts of the compound represented by the above formula (1) and the compound represented by the above formula (2) in the mixture, for example, it can be confirmed by the internal standard method using HPLC.

[0021] Examples of the aromatic hydrocarbons contained in the mixture of the present invention include toluene, xylene, mesitylene and the like. These aromatic hydrocarbons may be used alone or in combination of two or more.

[0022] Examples of the aliphatic alcohols having 1 to 6 carbon atoms contained in the mixture of the present invention include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, pentanol, hexanol and the like. Among these aliphatic alcohols, aliphatic alcohols having 1 to 3 carbon atoms are preferred, and methanol, ethanol, and n-propanol are more preferred. These aliphatic alcohols may be used alone or in combination of two or more.

[0023] In the mixture of the present invention, the ratio of the aromatic hydrocarbons to the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms is 5 to 95% by weight, preferably 10 to 90% by weight.

[0024] The mixture of the present invention may contain other components other than the compound represented by the above formula (1), the compound represented by the above formula (2), the aromatic hydrocarbons, and the aliphatic alcohols having 1 to 6 carbon atoms. Examples of the other components that may be contained include monomers other than the compounds represented by the above formulas (1) and (2) that constitute resins such as polycarbonate subjected to decomposition, and other organic solvents.

[0025] When a monomer other than the compounds represented by the above formulas (1) and (2) is included, its amount is, for example, 50 parts by weight or less, preferably 10 parts by weight or less, based on 100 parts by weight of the total amount of the compounds represented by the above formula (1) and the compounds represented by the above formula (2).

[0026] Examples of other organic solvents that may be included include aliphatic hydrocarbons, esters, ethers, ketones, and the like. Examples of the aliphatic hydrocarbons include hexane, cyclohexane, heptane, and the like. Examples of the esters include ethyl acetate, isopropyl acetate, isobutyl acetate, and the like. Examples of the ethers include tetrahydrofuran, dioxane, and the like. Examples of the ketones include acetone, 2-butanone, 4-methyl-2-pentanone, and cyclohexanone, and the like. When other organic solvents are included, their amount is, for example, 50 parts by weight or less, preferably 30 parts by weight or less, based on 100 parts by weight of the total amount of the aromatic hydrocarbons and aliphatic alcohols having 1 to 6 carbon atoms in the above solution.

[0027] In addition, the total amount of the aromatic hydrocarbons and aliphatic alcohols having 1 to 6 carbon atoms in the mixture of the present invention is, for example, 40 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts by weight of the total amount of the compounds represented by the above formula (1) and the compounds represented by the above formula (2).

[0028] <Method for preparing the mixture of the present invention> The method for preparing the mixture of the present invention is not particularly limited. For example, a depolymerization composition obtained by depolymerizing a polycarbonate resin having structural units derived from the compound represented by the above formula (1) and the compound represented by the above (2) (the depolymerization composition containing the compound represented by the above formula (1) and the compound represented by the above formula (2), and monomers other than the compounds represented by the above formulas (1) and (2) that constitute a resin such as polycarbonate subjected to decomposition as necessary, etc.), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms are added to a reaction vessel so as to have the above-described ratios, and the mixture of the present invention can be prepared by mixing as necessary. When the amount of the compound represented by the above formula (1) contained in the mixture to be prepared is small (the ratio of the compound represented by the above formula (1) to the total amount of the compound represented by the above formula (1) and the compound represented by the above formula (2) is less than 50% by weight), it can be prepared so as to be within the above range by newly adding the compound represented by the above formula (1).

[0029] Also, when preparing the mixture of the present invention, after adding a depolymerization composition obtained by depolymerizing a polycarbonate resin having structural units derived from the compound represented by the above formula (1) and the compound represented by the above (2), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms to a reaction vessel so as to have the above-described ratios, heating as necessary while mixing, once dissolving the crystals to form a solution, and then crystallizing the solution (precipitating crystals from the solution), the mixture of the present invention can also be prepared. By once forming a solution, it becomes possible to subject the solution to purification operations such as washing with water and filtering out insoluble components such as inorganic components before preparing the mixture of the present invention, which is preferable. The temperature at which crystals are precipitated from the solution is not particularly limited, but is usually 25°C or higher, preferably 60°C or higher. Examples of the method for precipitating crystals within the above temperature range include a method of maintaining the temperature of the crystallization solution so as to be within the above temperature range until crystals are precipitated, and a method of inoculating seed crystals within the above temperature range. Further, after precipitating crystals, an operation of holding at the same temperature for a certain time to grow the crystals may be performed as necessary, or further cooling may be performed.

[0030] <Recovery process> By preparing the mixture of the present invention by the method described above, since the purity of the compound represented by the formula (1) contained in the crystals of the mixture is usually 95% or more, by simply separating and recovering the crystals from the mixture, crystals of the compound represented by the formula (1) with high purity (for example, purity of 95% or more, preferably 98% or more) can be obtained. The crystals of the compound represented by the above formula (1) obtained may be washed, dried, etc. as necessary. Further, purification operations such as adsorption, steam distillation, recrystallization, etc. may be performed as necessary. In addition, the purity in the present invention means the HPLC purity measured under the conditions described in the Examples section described later.

Examples

[0031] The present invention will be specifically described below with reference to Examples and the like, but the present invention is not limited in any way. In the examples, various measurements were carried out by the following methods. The purity (HPLC purity) of the compound represented by the above formula (1) described in the following Examples and Comparative Examples is the area percentage value of HPLC measured under the following conditions.

[0032] (1) HPLC measurement conditions Apparatus: LC-2010A manufactured by Shimadzu Corporation, Column: waters XBridge Shield RP18 (150mm×4.6mm I.D., 3.5μm), Mobile phase: pure water / acetonitrile (acetonitrile 30%→100%), Flow rate: 1.0 ml / min, column temperature: 40°C, detection wavelength: UV 254nm.

[0033] <Example 1> To a glass reactor equipped with a stirrer, a heating / cooling device, and a thermometer, 50 g of the compound represented by the above formula (1), 21 g of the compound represented by the above formula (2), 17 g of toluene, and 150 g of methanol were added (ratio of the compound represented by the above formula (1) to the total amount of the compound represented by the above formula (1) and the compound represented by the above formula (2) in the mixture: 70% by weight, ratio of toluene to the total amount of toluene and methanol: 10% by weight). Then, while stirring, the internal temperature was raised to 65°C, and stirring was carried out at the same temperature for 1 hour to prepare the mixture of the present invention. During this period, the mixture did not become a solution, and part of the crystals remained precipitated. Subsequently, it was cooled to 20°C, stirred at the same temperature for 12 hours, and then the crystals were filtered off and washed twice with 71 g of methanol. The obtained crystals were dried at an internal temperature of 90°C under a reduced pressure of 2.0 kPa for 8 hours to obtain 47 g of crystals of the compound represented by the above formula (1) (purity: 98.8%).

[0034] <Example 2> To a glass reactor equipped with a stirrer, a heating / cooling device, and a thermometer, 50 g of the compound represented by the above formula (1), 21 g of the compound represented by the above formula (2), 67 g of toluene, and 100 g of methanol were added. Then, while stirring, the internal temperature was raised to 65°C to completely dissolve the compound represented by the above formula (1) and the compound represented by the above formula (2) (ratio of the compound represented by the above formula (1) to the total amount of the compound represented by the above formula (1) and the compound represented by the above formula (2) in the mixture: 70% by weight, ratio of toluene to the total amount of toluene and methanol: 40% by weight). Subsequently, after cooling to an internal temperature of 60°C, it was kept at the same temperature for 3 hours to precipitate crystals, thereby preparing the mixture of the present invention. Further, it was cooled to 20°C, stirred at the same temperature for 12 hours, and then the crystals were filtered off and washed twice with 71 g of methanol. The obtained crystals were dried at an internal temperature of 90°C under a reduced pressure of 2.0 kPa for 8 hours to obtain 47 g of crystals of the compound represented by the above formula (1) (purity: 98.9%).

[0035] <Example 3> In Example 2, except that the amounts of toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 2, and 43 g of crystals of the compound represented by the above formula (1) (purity: 98.7%) were obtained.

[0036] <Example 4> In Example 1, except that the amounts of the compound represented by the above formula (1), the compound represented by the above formula (2), toluene, and methanol used were changed as described in Table 1, the procedure was the same as in Example 1, and 39 g of crystals of the compound represented by the above formula (1) (purity: 98.7%) were obtained.

[0037] <Example 5> In Example 2, except that the amount of toluene used, the type of alcohol, and the amount thereof used were changed as described in Table 1, the procedure was the same as in Example 2, and 39 g of crystals of the compound represented by the above formula (1) (purity: 98.7%) were obtained.

[0038] <Example 6> In Example 2, except that the amount of toluene used, the type of alcohol, and the amount thereof used were changed as described in Table 1, the procedure was the same as in Example 2, and 41 g of crystals of the compound represented by the above formula (1) (purity: 98.7%) were obtained.

[0039] <Example 7> In Example 2, except that the amount of toluene used, the type of alcohol, and the amount thereof used were changed as described in Table 1, the procedure was the same as in Example 2, and 45 g of crystals of the compound represented by the above formula (1) (purity: 96.6%) were obtained. The results are shown in Table 1.

[0040] <Comparative Example 1> In Example 1, except that the amounts of toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 1, and 59 g of crystals of the compound represented by the above formula (1) (purity: 92.8%) were obtained.

[0041] <Comparative Example 2> In Example 2, except that the amounts of toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 2, and 57 g of crystals of the compound represented by the above formula (1) (purity: 93.4%) were obtained.

[0042] <Comparative Example 3> In Example 1, except that the amounts of toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 1, and 62 g of crystals of the compound represented by the above formula (1) (purity: 86.7%) were obtained.

[0043] <Comparative Example 4> In Example 2, except that the amounts of toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 2, and 63 g of crystals of the compound represented by the above formula (1) (purity: 92.6%) were obtained.

[0044] <Comparative Example 5> In Example 2, except that the amounts of the compound represented by the above formula (1), the compound represented by the above formula (2), toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 2, and 56 g of crystals of the compound represented by the above formula (1) (purity: 68.7%) were obtained.

[0045] <Comparative Example 6> In Example 2, except that the amounts of the compound represented by the above formula (1), the compound represented by the above formula (2), toluene and methanol used were changed as described in Table 1, the procedure was the same as in Example 2, and 30 g of crystals of the compound represented by the above formula (1) (purity: 1.6%) were obtained.

[0046] <Comparative Example 7> In Example 2, except that the amount of toluene used, the type of alcohol and its amount used were changed as described in Table 1, the procedure was the same as in Example 2, and 34 g of crystals of the compound represented by the above formula (1) (purity: 94.1%) were obtained.

[0047]

Table 1

Claims

1. A mixture comprising a crystal and a solution, represented by the following formula (1): 【Chemical Formula 1】 a compound represented by the following formula (2): 【Chemical Formula 2】 containing a compound represented by the formula, aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms, based on the total amount of the compound represented by formula (1) and the compound represented by formula (2), the ratio of the compound represented by formula (1) is 50% by weight or more, based on the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms, the ratio of the aromatic hydrocarbons is 5 to 95% by weight, the aromatic hydrocarbons are at least one selected from the group consisting of toluene, xylene, and mesitylene, based on 100 parts by weight of the total amount of the compound represented by formula (1) and the compound represented by formula (2), the total amount of monomers other than the compound represented by formula (1) and the compound represented by formula (2) is 50 parts by weight or less, a mixture.

2. based on 100 parts by weight of the total amount of the compound represented by formula (1) and the compound represented by formula (2), the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms is 40 to 2000 parts by weight, the mixture according to claim 1.

3. A solution for producing the mixture according to claim 1 or 2, containing the compound represented by the above formula (1), the compound represented by the above formula (2), aromatic hydrocarbons, and aliphatic alcohols having 1 to 6 carbon atoms, based on the total amount of the compound represented by formula (1) and the compound represented by formula (2), the ratio of the compound represented by formula (1) is 50% by weight or more, based on the total amount of the aromatic hydrocarbons and the aliphatic alcohols having 1 to 6 carbon atoms, the ratio of the aromatic hydrocarbons is 5 to 95% by weight, the aromatic hydrocarbons are at least one selected from the group consisting of toluene, xylene, and mesitylene, A solution in which the total amount of monomers other than the compound represented by formula (1) and the compound represented by formula (2) is 50 parts by weight or less with respect to 100 parts by weight of the total amount of the compound represented by formula (1) and the compound represented by formula (2).

4. A method for producing the mixture according to claim 1 or 2, comprising a step of precipitating crystals from the solution according to claim 3.

5. A method for recovering crystals of the compound represented by formula (1), which comprises separating crystals from the mixture according to claim 1 or 2.

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