Method for producing dicarboxylic acid compound and method for producing recycled resins

Abstract

The present invention addresses the problem of efficiently recycling waste resin compositions such as synthetic resins, enabling the reuse of a wider variety of resins than before.　The problem is solved by a method for producing a dicarboxylic acid compound, said method including a crystallization step for crystallizing at least the dicarboxylic acid compound from a mixed liquid containing a dicarboxylic acid compound represented by general formula (1-1) or general formula (1-2) and a dihydroxy compound represented by general formula (2-1) or general formula (2-2).　The substituents and the like in the general formulas are as described in the description of the present application.

Description

Method for producing dicarboxylic acid compound and method for producing recycled resin

[0001] The present invention relates to a method for producing a dicarboxylic acid compound, a method for producing a recycled resin, and the like.

[0002] In recent years, concerns have grown over the deterioration of the natural environment and the increase in waste emissions, and there has been an increasing movement to reuse and recycle plastic products in an effort to realize a recycling-oriented society.

[0003] Synthetic resins such as polycarbonate resin, which are the main constituents of plastic products, are widely used in a variety of applications, such as home appliances, electronic and electrical equipment, office automation equipment, optical media, automobile parts, building materials, etc. During the production of the above-mentioned plastic products and after their use, a large amount of synthetic resin waste is generated, and therefore, these waste materials are being recycled.

[0004] In particular, when plastic products are manufactured by molding synthetic resins, the parts originating from the passages of the mold, such as sprues, runners, and gates, are removed to produce the plastic products. Efforts are being made to recycle and reuse waste resins, such as synthetic resins that are no longer needed for such plastic products and are removed, as well as other waste resins such as defective moldings, in products, rather than disposing of them.

[0005] For example, Patent Document 1 describes a method for recovering polycarbonate resin, which includes a step of crushing discarded optical discs and / or recovered optical discs having a polycarbonate resin substrate and chemically treating the resulting crushed material. In this recovery method, the chemically treated material obtained in the chemical treatment step is subjected to a step of removing magnetic metallic foreign matter using a magnet, a step of removing colored foreign matter using an optical camera, and a step of removing resin containing metallic foreign matter using a metallic foreign matter detector.

[0006] Also known is a method of recycling waste resin compositions and reusing compounds that were raw materials for the resin (see, for example, Patent Document 2).

[0007] JP 2011-131507 A International Publication No. 2023 / 058599

[0008] Among conventional synthetic resin recovery methods, for example, the method described in Patent Document 1 recovers synthetic resins based on the appearance of metals contained therein or coloration. However, if the metal content, coloration level, etc., do not differ significantly between the desired synthetic resin and other unwanted organic impurities, it may be difficult to efficiently recover the desired synthetic resin. Furthermore, even with conventional methods for recycling waste resin compositions, the types of resins that can be recovered and reused are limited.

[0009] Under these circumstances, there is a need for a new method for efficiently recycling waste resin compositions and reusing a wider variety of resins than before. Therefore, a main object of the present invention is to provide a method for recycling waste resin compositions containing synthetic resins, thereby enabling the reuse of a wider variety of resins than before.

[0010] The present invention has the following aspects, for example: [1] A method for producing a dicarboxylic acid compound represented by the following general formula (1-1) or (1-2), comprising a crystallization step of crystallizing at least the dicarboxylic acid compound from a mixed solution containing the dicarboxylic acid compound and a dihydroxy compound represented by the following general formula (2-1) or (2-2): (In general formula (1-1), R ａ１ and R ｂ１ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ１ R is selected from the group consisting of ｈ１represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, X １ represents a single bond or an optionally substituted fluorene group; １ and B １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent, and m １ and n １ each independently represents an integer of 0 to 6, １ and b １ each independently represents an integer of 0 to 10; １ ' and R １ '' are each independently selected from the group consisting of a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted aryl group having 6 to 20 carbon atoms. (In general formula (1-2), R ａ２ and R ｂ２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ２ R is selected from the group consisting of ｈ２ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, X ２ represents a single bond, a fluorene group which may have a substituent, or any of the structural formulae represented by the following formulae (8) to (15): (In formulas (8) to (15), R ６１ , R ６２ , R ７１ , R７２ , R ８１ and R ８２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 30 carbon atoms which may have a substituent, or R ６１ and R ６２ , or R ７１ and R ７２ are bonded to each other to form a carbocyclic or heterocyclic ring having 1 to 20 carbon atoms, which may have a substituent; A ２ and B ２ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent, and m ２ and n ２ each independently represents an integer of 0 to 6, ２ and b ２ each independently represents an integer of 0 to 10; ２ ' and R ２ '' are each independently selected from the group consisting of a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted aryl group having 6 to 20 carbon atoms. (In general formula (2-1), R ｃ and R ｄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ３ R is selected from the group consisting of ｈ３ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent; Y １ represents a single bond or an optionally substituted fluorene group; C１ and D １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; p and q each independently represent an integer of 0 to 6; and c and d each independently represent an integer of 0 to 10. (In general formula (2-2), R ｅ and R ｆ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent; ２ represents a single bond, a fluorene group which may have a substituent, or any of the structural formulae represented by the following formulae (8) to (15): (In formulas (8) to (15), R ６１ , R ６２ , R ７１ , R ７２ , R ８１ and R ８２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 30 carbon atoms which may have a substituent, or R ６１ and R ６２ , or R ７１ and R ７２ are bonded to each other to form a carbocyclic or heterocyclic ring having 1 to 20 carbon atoms, which may have a substituent, and r and s each independently represent an integer of 0 to 5,000. １ and F １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; t and u each independently represent an integer of 0 to 4; and e and f each independently represent an integer of 0 to 10.

[0011] [2] The method for producing a dicarboxylic acid compound according to [1] above, further comprising a first washing step of washing the mixed solution containing the dicarboxylic acid compound with an acidic aqueous solution. [3] The method for producing a dicarboxylic acid compound according to [1] above or [2], for example, [1] above, further comprising a first solution-forming step of dissolving the dicarboxylic acid compound in a polar solvent to obtain the mixed solution. [4] The method for producing a dicarboxylic acid compound according to [3] above, further comprising: in the first solution-forming step, dissolving the dicarboxylic acid compound and the dihydroxy compound in a polar solvent to obtain the mixed solution; and in the crystallization step, crystals of only the dicarboxylic acid compound are crystallized from the mixed solution.

[0012] [5] A method for producing a dicarboxylic acid compound according to any one of [1] to [4] above, for example, the method according to [1] above, further comprising a second washing step of washing the mixed solution containing the dicarboxylic acid compound with an organic solvent. [6] A method for producing a dicarboxylic acid compound according to any one of [1] to [5] above, for example, the method according to [1] above, further comprising a second solution-forming step of dissolving the dicarboxylic acid compound in an organic solvent to obtain the mixed solution. [7] A method for producing a dicarboxylic acid compound according to [6] above, further comprising: in the second solution-forming step, dissolving the dicarboxylic acid compound and the dihydroxy compound in an organic solvent to obtain the mixed solution; and in the crystallization step, crystallizing a co-crystal of the dicarboxylic acid compound and the dihydroxy compound from the mixed solution.

[0013] [8] A method for producing a dicarboxylic acid compound according to any one of the above [1] to [7], for example, the above [1], further comprising a decomposition step of decomposing a polyester carbonate resin and / or polyester resin having a structural unit derived from a dicarboxylic acid compound, represented by at least the following general formula (1-1') or the following general formula (1-2'), to obtain the dicarboxylic acid compound represented by the general formula (1-1) or the general formula (1-2). (The symbols in general formula (1-1') have the same meanings as those in general formula (1-1) above.) (The symbols in general formula (1-2') have the same meanings as in general formula (1-2).) [9] The method for producing a dicarboxylic acid compound according to the above item [8], wherein in the decomposition step, the polyester carbonate resin and / or polyester resin is dissolved in a first solvent and treated with an alkaline solution to obtain a reaction solution containing a dicarboxylic acid compound of formula (1-1) or the following general formula (1-2) and the first solvent; and in the crystallization step, the dicarboxylic acid compound is crystallized from a crystallization mixture obtained by adding a second solvent to the reaction solution; and the difference between the solubility of the dicarboxylic acid compound in the first solvent at 25°C and the solubility of the dicarboxylic acid compound in the second solvent at 25°C is 0.1 g / 10 mL or more.

[10] The method for producing a dicarboxylic acid compound according to the above item [9], wherein the content of the first solvent in the crystallization mixture is 0.1 to 10 g / g relative to the total amount of the dicarboxylic acid compound mixture.

[11] The production method according to [9] or

[10] above, for example, [9] above, wherein the content of the second solvent in the crystallization mixture is 0.3 to 3 g / g relative to the total amount of the dicarboxylic acid compound mixture.

[12] The production method according to any of [9] to

[11] above, for example, [9] above, wherein the total content of the first solvent and the second solvent in the crystallization mixture is 1 to 10 g / g relative to the total amount of the dicarboxylic acid compound mixture.

[13] The production method according to any of [9] to

[12] above, for example, [9] above, wherein the ratio of the content (g / g) of the first solvent to the content (g / g) of the second solvent in the crystallization mixture (first solvent / second solvent) is 0.8 to 10.

[14] The production method according to any one of [1] to

[13] above, for example, [1] above, wherein in the crystallization step, seed crystals of the dicarboxylic acid compound or the dihydroxy compound are added to the mixed solution to crystallize a co-crystal of the dicarboxylic acid compound and the dihydroxy compound.

[0014]

[15] A method for producing a dicarboxylic acid compound represented by the following general formula (1-1) or the following general formula (1-2), comprising a crystallization step of crystallizing at least the dicarboxylic acid compound from a mixed solution containing the dicarboxylic acid compound. Each symbol in the general formula (1-1) here has the same meaning as in the general formula (1-1) of [1] above. Each symbol in the general formula (1-2) here has the same meaning as in the general formula (1-1) in [1] above.

[0015]

[16] A method for producing a recycled resin, comprising a polymerization step of polymerizing a dicarboxylic acid compound produced by the method according to any one of [1] to

[15] above, for example, the method according to [1] above.

[0016] According to the present invention, waste resin compositions containing synthetic resins and the like can be efficiently recycled, and a wider variety of resins than conventionally possible can be reused.

[0017] Hereinafter, embodiments of the present invention will be described in detail.

[0018] 1. Method for Producing Dicarboxylic Acid Compound 1-1. Dicarboxylic Acid Compound According to one embodiment of the present invention, there is provided a method for producing a dicarboxylic acid compound represented by the following general formula (1-1) or the following general formula (1-2). These dicarboxylic acid compounds are crystallized from a mixed solution containing at least the dicarboxylic acid compound, or preferably from a mixed solution containing the dicarboxylic acid compound and a predetermined dihydroxy compound.

[0019] In general formula (1-1), R ａ１ and R ｂ１ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ１ R ｈ１is an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, and R ｈ１ is preferably an aryl group having 6 to 20 carbon atoms which may have a substituent, and more preferably an aryl group having 6 to 12 carbon atoms which may have a substituent.

[0020] R in general formula (1-1) ａ１ and R ｂ１ is preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, more preferably a hydrogen atom, or an aryl group having 6 to 20 carbon atoms which may have a substituent, and even more preferably a hydrogen atom, or an aryl group having 6 to 12 carbon atoms which may have a substituent.

[0021] In the general formula (1-1), X １ represents a single bond or a fluorene group which may have a substituent, and is preferably a single bond. １ and B １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent. １ and B １ is preferably an alkylene group having 1 to 3 carbon atoms which may have a substituent, and more preferably an alkylene group having 1 or 2 carbon atoms. １ and n １ Each independently represents an integer of 0 to 6. １ and n １ is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and particularly preferably 0 or 1. In general formula (1-1), a １ and b １ each independently represents an integer of 0 to 10. １ and b １ is preferably an integer of 0 to 5, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, and particularly preferably 0 or 1.

[0022] In general formula (1-1), R １ ' and R １ R '' are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. １ ' and R １ " is preferably an integer of 0 to 5, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, and particularly preferably 0 or 1. Thus, R in general formula (1-1) １ ' and R １ As is clear from the fact that each of "" and "" can be independently selected from a hydrogen atom, an alkyl group, an aryl group, and the like, the dicarboxylic acid compound in this specification includes not only dicarboxylic acids but also monocarboxylic acid monoester compounds and carboxylic acid diester compounds.

[0023] Specific examples of the dicarboxylic acid compound of general formula (1-1) include 2,2'-([1,1'-binaphthalene]-2,2'-diylbis(oxy))acetoacetic acid (BINOL-DC), 2,2'-bis(ethoxycarboxymethoxy)-1,1'-binaphthyl, 2,2'-bis(2-ethoxycarboxyethoxy)-1,1'-binaphthyl, 2,2'-bis(3-ethoxycarboxypropoxy)-1,1'-binaphthyl, 2,2'-bis(3-ethoxycarboxy-2-methylpropoxy)-1,1'-binaphthyl, 2,2'-bis(4-ethoxycarboxyphenylmethoxy)-1,1'-binaphthyl, 2,2'- Examples thereof include biphenyldicarboxylic acid, 2,2'-bis(methoxycarboxymethoxy)-1,1'-binaphthyl, 2,2'-bis(2-methoxycarboxyethoxy)-1,1'-binaphthyl, 2,2'-bis(3-methoxycarboxypropoxy)-1,1'-binaphthyl, 2,2'-bis(3-methoxycarboxy-2-methylpropoxy)-1,1'-binaphthyl, 2,2'-bis(4-methoxycarboxyphenylmethoxy)-1,1'-binaphthyl, dimethyl 2,2'-biphenyldicarboxylate, diethyl 2,2'-biphenyldicarboxylate, and diphenyl 2,2'-biphenyldicarboxylate.

[0024] Specific examples of the dicarboxylic acid compound of general formula (1-1) having a fluorene group include 9,9-bis(carboxynaphthyl)fluorene, 9,9-bis(carboxy-alkylphenyl)fluorene, and 9,9-bis(carboxyphenyl)fluorene. For example, 9,9-bis(carboxynaphthyl)fluorenes such as 9,9-bis(6-carboxy-2-naphthyl)fluorene and 9,9-bis(5-carboxy-1-naphthyl)fluorene; 9,9-bis(carboxy-alkylphenyl)fluorenes including 9,9-bis(carboxy-(mono- or di-)C1-4 alkylphenyl)fluorenes such as 9,9-bis(4-carboxy-3-methylphenyl)fluorene and 9,9-bis(4-carboxy-3,5-dimethylphenyl)fluorene; 9,9-bis(carboxyphenyl)fluorenes such as 9,9-bis(4-carboxyphenyl)fluorene; 9,9-bis(carboxy-arylphenyl)fluorenes including 9,9-bis(carboxy-C6-10 arylphenyl)fluorenes such as 9,9-bis(4-carboxy-3-phenylphenyl)fluorene.

[0025] Among the specific examples of the dicarboxylic acid compound of the above formula (1-1), BINOL-DC, 2,2'-bis(ethoxycarboxymethoxy)-1,1'-binaphthyl, 2,2'-bis(methoxycarboxymethoxy)-1,1'-binaphthyl, etc. are preferred. Note that mixed esters can also be used as the dicarboxylic acid compound.

[0026] Each substituent in the general formula (1-2) may have the same meaning as the corresponding substituent in the general formula (1-1) above. That is, in the general formula (1-2), R ａ２ and R ｂ２ is R in formula (1-1) ａ１ and R ｂ１ and R in general formula (1-2) ａ２ and R ｂ２each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ２ In addition, the above R in the general formula (1-2) can be selected from the group consisting of ｈ２ is R in formula (1-1) ｈ１ and may represent an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N, and S and which may have a substituent.

[0027] R in general formula (1-2) ａ２ and R ｂ２ is preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, more preferably a hydrogen atom, or an aryl group having 6 to 20 carbon atoms which may have a substituent, and even more preferably a hydrogen atom, or an aryl group having 6 to 12 carbon atoms which may have a substituent.

[0028] X in general formula (1-2) ２ represents X in general formula (1-1). １ and X ２ A in general formula (1-2) may represent a single bond or a fluorene group which may have a substituent, and is preferably a single bond. ２ and B ２ represents A in general formula (1-1). １ and B １ and A ２ and B ２may each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent. １ and B １ is preferably an alkylene group having 1 to 3 carbon atoms which may have a substituent, and more preferably an alkylene group having 1 or 2 carbon atoms. ２ and n ２ is m in general formula (1-1). １ and n １ and m ２ and n ２ may each independently represent an integer of 0 to 6. １ and n １ is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and particularly preferably 0 or 1. ２ and b ２ represents a in general formula (1-1). １ and b １ and a ２ and b ２ may each independently represent an integer of 0 to 10. １ and b １ is preferably an integer of 0 to 5, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, and particularly preferably 0 or 1.

[0029] R in general formula (1-2) ２ ' and R ２ ″ is R in general formula (1-1) １ ' and R １ '', and R ２ ' and R ２ Each of R '' can be independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. １ ' and R １ " is preferably an integer of 0 to 5, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, and particularly preferably 0 or 1. Thus, R in general formula (1-2) ２' and R ２ As is clear from the fact that each of "" and "" can be independently selected from a hydrogen atom, an alkyl group, an aryl group, and the like, the dicarboxylic acid compound in this specification includes not only dicarboxylic acids but also monocarboxylic acid monoester compounds and carboxylic acid diester compounds.

[0030] In addition, each substituent in the general formula (1-2) may be different from the substituent in the general formula (1-1). For example, R ａ２ and R ｂ２ represents R in general formula (2-2). ｅ and R ｆ and R ａ２ and R ｂ２ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. ａ２ and R ｂ２ Preferred options for R in general formula (2-2) described below are ｅ and R ｆ In addition, X in general formula (1-2) may be the same as ２ represents Y in general formula (2-2). ２ and X ２ can be a single bond, a fluorene group which may have a substituent, or any of the structural formulas represented by the above formulas (8) to (15). ２ Preferred options are Y in general formula (2-2) described below. ２ It may be similar to:

[0031] A in general formula (1-2) ２ and B ２ represents E in general formula (2-2). ２ and F ２ and A ２ and B ２may each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent. ２ and B ２ Preferred options for E in general formula (2-2) described below are ２ and F ２ In addition, m in the general formula (1-2) may be the same as ２ and n ２ may have the same meanings as t and u in the general formula (2-2), and m ２ and n ２ may each independently represent an integer of 0 to 4. ２ and n ２ The preferred options for may be the same as those for t and u in general formula (2-2) described later.

[0032] a in general formula (1-2) ２ and b ２ may have the same meanings as e and f in general formula (2-2), ２ and b ２ may each independently represent an integer of 0 to 10. ２ and b ２ The preferred options for may be the same as e and f in the general formula (2-2) described later.

[0033] Specific examples of the dicarboxylic acid compound of general formula (1-2) include those in which the naphthyl ring of the dicarboxylic acid compound of formula (1-1) is substituted with a benzene ring. Examples of the dicarboxylic acid compound of general formula (1-2) include 9,9-bis(carboxyC2-6 alkyl)-dipyrenylfluorenes such as 9,9-bis(2-carboxyethyl)-2,7-di(1-pyrenyl)fluorene, 9,9-bis(2-carboxyethyl)-1,8-di(1-pyrenyl)fluorene, 9,9-bis(2-carboxyethyl)-3,6-di(1-pyrenyl)fluorene, 9,9-bis(2-carboxyethyl)-4,5-di(1-pyrenyl)fluorene, 9,9-bis(2-carboxyethyl)-2,7-di(2-pyrenyl)fluorene, and 9,9-bis(2-carboxypropyl)-2,7-di(1-pyrenyl)fluorene.

[0034] The dicarboxylic acid compound is preferably crystallized from a mixed solution containing not only the dicarboxylic acid compound but also at least one dihydroxy compound represented by the following general formula (2-1) or (2-2): In general formula (2-1), R ｃ and R ｄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ３ R ｈ３ is an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, and R ｈ３ is preferably an aryl group having 6 to 20 carbon atoms which may have a substituent, and more preferably an aryl group having 6 to 12 carbon atoms which may have a substituent.

[0035] R in general formula (2-1) ｃ and R ｄ is preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, more preferably a hydrogen atom, or an aryl group having 6 to 20 carbon atoms which may have a substituent, and even more preferably a hydrogen atom, or an aryl group having 6 to 12 carbon atoms which may have a substituent.

[0036] In the general formula (2-1), Y １ represents a single bond or a fluorene group which may have a substituent. １ is Y, which will be described later.２ It may be synonymous with １ is preferably a single bond or a fluorene group having a total of 12 to 20 carbon atoms which may have a substituent. １ and D １ are each independently an alkylene group having 1 to 5 carbon atoms, which may have a substituent, and preferably an alkylene group having 2 or 3 carbon atoms. In general formula (2-1), p and q are each independently an integer of 0 to 6, preferably an integer of 0 to 3, and more preferably 0 or 1. In general formula (2-1), c and d are each independently an integer of 0 to 10, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0037] Specific examples of the dihydroxy compound of the general formula (2-1) include 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BNE), 2,2'-bis(2-hydroxyethoxy)-6,6'-diphenyl-1,1'-binaphthalene (DPBHBNA), and the like.

[0038] In general formula (2-2), R ｅ and R ｆ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. ｅ and R ｆ is preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, more preferably a hydrogen atom, or an aryl group having 6 to 20 carbon atoms which may have a substituent, and even more preferably a hydrogen atom, or an aryl group having 6 to 12 carbon atoms which may have a substituent.

[0039] In the general formula (2-2), Y ２represents a single bond, a fluorene group which may have a substituent, or any of the structural formulae represented by the following formulas (8) to (15), and is preferably a single bond or the structural formula represented by the following formula (8): In formulas (8) to (15), R ６１ , R ６２ , R ７１ , R ７２ , R ８１ and R ８２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 30 carbon atoms which may have a substituent, or R ６１ and R ６２ , or R ７１ and R ７２ are bonded to each other to form a carbon ring or hetero ring having 1 to 20 carbon atoms, which may have a substituent. In formulas (8) to (15), r and s each independently represent an integer of 0 to 5,000.

[0040] In the general formula (2-2), E ２ and F ２ each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent, and is preferably an alkylene group having 2 or 3 carbon atoms. In general formula (2-2), t and u each independently represent an integer of 0 to 4, and is preferably 0 or 1. In general formula (2-2), e and f each independently represent an integer of 0 to 10, preferably an integer of 0 to 5, and more preferably an integer of 0 to 2, for example, 0 or 1.

[0041] Specific examples of the dihydroxy compound of general formula (2-2) include BCFL (9,9-bis(4-hydroxy-3-methylphenyl)fluorene), BPEF (9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene), BPPEF (9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene), BNEF (9,9-bis[6-(2-hydroxyethoxy)naphthalen-2-yl]fluorene), bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bis(4-hydroxyphenyl)-2,2-dichloroethylene, bisphenol E, bisphenol F, bisphenol G, bisphenol M (BPM), bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol P-AP (4,4'-(1-phenylethylidene)bisphenol), and bisphenol P-CDE. (4,4'-cyclododecylidene bisphenol), bisphenol P-HTG (4,4'-(3,3,5-trimethylcyclohexylidene) bisphenol), bisphenol P-MIBK (4,4'-(1,3-dimethylbutylidene) bisphenol), bisphenol PEO-FL (bisphenoxyethanol fluorene), bisphenol P-3MZ (4-[1-(4-hydroxyphenyl)-3-methylcyclohexyl]phenol), bisphenol Examples of suitable dihydroxy compounds include bisphenol Z, bisphenol Z, bisphenol B ...

[0042] 1-2. Steps in the Method for Producing Dicarboxylic Acid Compounds The method for producing a dicarboxylic acid compound of the present invention includes a crystallization step of crystallizing the dicarboxylic acid compound described above. According to a production method using such a crystallization step, a dicarboxylic acid compound or the like can be obtained as a desired resin-derived monomer compound from, for example, a waste resin composition that may contain impurities. Furthermore, a dihydroxy compound can be produced. That is, according to the production method of the present invention, a high-purity dicarboxylic acid compound, a dihydroxy compound, or the like can be produced from a waste resin composition. This makes it possible to produce a high-quality resin when producing a resin (recycled resin) using the resulting dicarboxylic acid compound, dihydroxy compound, or the like, and thus allows the waste resin composition to be suitably recycled.

[0043] The method for producing a dicarboxylic acid compound of the present invention may include, for example, a decomposition step of producing a dicarboxylic acid compound from a waste resin composition. In the decomposition step, preferably, a polyester carbonate resin, a polyester resin, or the like having a structural unit derived from a dicarboxylic acid compound represented by at least the following general formula (1-1') or the following general formula (1-2') is decomposed (depolymerized). Each symbol in the general formula (1-1') has the same meaning as in the general formula (1-1) above. Each symbol in the general formula (1-2') has the same meaning as in the general formula (1-2) above.

[0044] According to the decomposition process, the dicarboxylic acid compound represented by the above-mentioned general formula (1-1) or general formula (1-2) can be efficiently obtained. A waste resin composition can be used as the resin or resin composition to be subjected to the decomposition process. In this specification, the waste resin composition includes a resin composition that has been once manufactured into a product and is no longer used for the application of that product, and a resin composition that has been discarded regardless of whether it has been used or not.

[0045] In the decomposition step, it is preferable to dissolve at least one of a polyester carbonate resin and a polyester resin in a first solvent and treat the solution with an alkaline solution to obtain a reaction solution containing the dicarboxylic acid compound of formula (1-1) or (1-2) and the first solvent. In the crystallization step performed thereafter, it is preferable to crystallize the dicarboxylic acid compound from a crystallization mixture obtained by adding a second solvent to the reaction solution.

[0046] (Alkaline Solution) The alkaline solution contains, for example, a first solvent and water. The alkaline solution may further contain other substances such as a metal oxide.

[0047] The resin decomposed in the decomposition step may further contain a structural unit other than a structural unit derived from a dicarboxylic acid compound and a structural unit derived from a dihydroxy compound. Examples of such structural units include, but are not limited to, a structural unit derived from an olefin and a structural unit derived from an ester. The resin may contain the other structural units alone or in combination of two or more. The resin may contain the above-mentioned resin alone or in a mixture of two or more.

[0048] The weight-average molecular weight (Mw) of the resin decomposed in the decomposition step is not particularly limited, but is preferably 10,000 to 70,000, and more preferably 15,000 to 50,000. A weight-average molecular weight (Mw) of the resin of 10,000 or more is preferable because it can maintain appropriate strength as a molded product, such as a resin for an optical lens. On the other hand, a weight-average molecular weight (Mw) of the resin of 70,000 or less is preferable because it can maintain appropriate fluidity during resin molding and improve moldability. In the resin decomposed in the decomposition step, the content of the resin derived from the waste resin composition described below is preferably 80% by mass or more, and more preferably 80 to 99% by mass. A content of the resin derived from the waste resin composition of 80% by mass or more is preferable because it increases efficiency.

[0049] Organic Impurities The resin composition decomposed in the decomposition step may contain organic impurities, and examples of the organic impurities include impurity resins, impurity compounds, etc. Among these, the impurity resin is preferably a polyolefin resin or a cyclic polyolefin, and more preferably a cyclic polyolefin, from the viewpoint of a large difference in chemical properties between the impurity resin and polyester carbonate resin, etc. (large difference in ease of depolymerization in an alkaline aqueous solution).

[0050] First Solvent The first solvent has functions such as promoting depolymerization decomposed in the decomposition step and dissolving the dihydroxy compound obtained by depolymerization. Examples of the first solvent include, but are not limited to, aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents. Examples of the aliphatic hydrocarbon solvent include, but are not limited to, pentane, hexane, heptane, octane, nonane, decane, cyclohexane, cyclodecane, and the like. Examples of the aromatic hydrocarbon solvent include, but are not limited to, toluene, xylene, mesitylene, and the like. Of these, the first solvent is preferably an aromatic hydrocarbon solvent, and more preferably toluene, xylene, or the like. The above-mentioned reaction solvents may be used alone or in combination of two or more.

[0051] The amount of the first solvent used is not particularly limited, but is preferably 30 to 2000 parts by mass, more preferably 40 to 1500 parts by mass, and even more preferably 100 to 1000 parts by mass, relative to 100 parts by mass of the resin composition to be decomposed in the decomposition step. When the amount of the first solvent used is 30 parts by mass or more, the organic components of the waste resin composition are sufficiently dissolved in the reaction solvent, which is preferable, thereby increasing the reaction efficiency. On the other hand, when the amount of the first solvent used is 2000 parts by mass or less, the reaction time is shortened, which is preferable.

[0052] Water has the function of accelerating the depolymerization of the resin composition, etc. The amount of water used is not particularly limited, but is preferably 10 to 2000 parts by mass, more preferably 20 to 500 parts by mass, still more preferably 30 to 300 parts by mass, and particularly preferably 40 to 100 parts by mass, relative to 100 parts by mass of the resin composition.

[0053] Metal Oxide The metal oxide has the function of adjusting the reaction solution in the decomposition step to alkaline and promoting depolymerization. The metal oxide is not particularly limited, but examples thereof include alkali metals such as sodium hydroxide, potassium hydroxide, and rubidium hydroxide; and alkaline earth metals such as calcium hydroxide and barium hydroxide. Among these, the metal oxide is preferably an alkali metal, more preferably sodium hydroxide or potassium hydroxide, and even more preferably potassium hydroxide. These metal oxides may be used alone or in combination of two or more.

[0054] The amount of metal oxide used is not particularly limited, but is preferably 1.5 to 10 mol, more preferably 2 to 8 mol, and even more preferably 2 to 4 mol, per mol of ester bond in polyester carbonate resin or the like. A metal oxide use amount of 1.5 mol or more is preferred because depolymerization is sufficiently carried out. On the other hand, a metal oxide use amount of 10 mol or less is preferred because production costs are reduced. The concentration of metal oxide in the alkaline aqueous solution is preferably 10 to 60 mass% relative to the total mass of the alkaline aqueous solution, more preferably 15 to 55 mass%, and even more preferably 20 to 50 mass%. A metal oxide concentration of 10 mass% or more is preferred because the depolymerization reaction rate is increased. On the other hand, a metal oxide concentration of 60 mass% or less is preferred because the alkaline aqueous solution does not become a slurry and the reaction proceeds more easily.

[0055] (Treatment) As described above, by treating a resin such as a polyester carbonate resin with an alkaline solution, a reaction solution containing a mixture containing a dicarboxylic acid compound and possibly other dihydroxy compounds, and a first solvent can be obtained.

[0056] The organic impurities that may be contained in the resin composition have different chemical properties during depolymerization compared to the above-mentioned resins. Therefore, the organic impurities either do not react, are depolymerized earlier than the above-mentioned resins, or are depolymerized later than the above-mentioned resins. For example, when the organic impurities are polyolefin resins, cyclic polyolefins, or the like, these compounds typically do not react under basic conditions, so that only the above-mentioned resins are depolymerized and can be easily removed. Even if the organic impurities are depolymerized, the depolymerized products of the organic impurities typically have a different polarity from the dihydroxy compound and can therefore be easily removed.

[0057] The treatment temperature in the decomposition step (depolymerization reaction temperature) is not particularly limited, but is preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 30 to 90° C. A treatment temperature of 120° C. or lower is preferred because side reactions can be prevented.

[0058] The solution obtained after the treatment (depolymerization) in the decomposition step can be purified by washing, extraction, or the like as appropriate to obtain a reaction solution for the subsequent crystallization step. The solution obtained after the treatment (depolymerization) usually contains an organic phase derived from the first solvent and an aqueous phase derived from water. In this case, the dicarboxylic acid compound obtained by depolymerization and the like may be contained in the organic phase. For this reason, it is preferable to remove the aqueous phase derived from water from the solution obtained after the treatment (depolymerization) by liquid-liquid extraction or the like.

[0059] Furthermore, if the organic impurities and depolymerized products thereof contained in the obtained reaction solution have physical properties different from those of the dicarboxylic acid compound, they can be removed by appropriate purification at this stage. In this case, the reaction solution and crystallization solution described below contain no or almost no organic impurities and depolymerized products thereof.

[0060] (Reaction Solution) The reaction solution preferably contains a dicarboxylic acid compound and the like and a first solvent. The reaction solution may further contain organic impurities, depolymerized products thereof, and the like.

[0061] The first solvent may be any of those described above. The content of the first solvent can be adjusted by distilling off the solvent or the like in a treatment after depolymerization. This allows the content of the first solvent in the crystallization solution described below to be adjusted.

[0062] Organic Impurities and Their Depolymerization Products The reaction solution may contain organic impurities and their depolymerization products. Organic impurities typically have significantly different molecular weights and polarities from dicarboxylic acid compounds, and therefore can be easily removed in the washing process described below. Depolymerization products of organic impurities are not particularly limited, and include monomers, oligomers, and the like obtained by depolymerization of organic impurities. For example, when polyester resin is included as an organic impurity, alcohols and carboxylic acids can be obtained by depolymerization. Among these depolymerization products, compounds such as alcohols have significantly different polarities from carboxylic acids such as dicarboxylic acid compounds, and therefore can be easily removed in the washing process described below.

[0063] (Solution Forming Step) The method for producing a dicarboxylic acid compound of the present invention may include a solution forming step of preparing a mixed solution containing a dicarboxylic acid compound and suitable for crystallization. In the solution forming step, the mixed solution may be obtained by dissolving the dicarboxylic acid compound in a polar solvent (first solution forming step), or by dissolving the dicarboxylic acid compound in an organic solvent (second solution forming step).

[0064] Examples of polar solvents include ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK), acetone, and cyclohexanone; ether solvents such as tetrahydrofuran, 1,3-dioxolane, and 1,4-dioxane; and alcohol solvents such as methanol, ethanol, propanol, isopropyl alcohol, butanol, and isobutyl alcohol. Among the specific examples mentioned above, the solvent used in the first solution formation step is preferably a ketone solvent, and more preferably methyl ethyl ketone (MEK). In addition to MEK, other suitable ketone solvents include those having 5 or less or 4 or less carbon atoms, and those having 3 or more carbon atoms. These solvents may be used alone or in combination of two or more. In addition, in the step of acid-base extraction of a dicarboxylic acid compound from an aqueous phase containing a dicarboxylic acid compound, it is preferable to first wash the aqueous phase with a solvent of relatively low polarity, for example, an organic solvent described below, and then acidify the aqueous phase, and further extract the dicarboxylic acid compound from the aqueous phase with a solvent such as the above-mentioned ketone solvent or an alcohol including a monool having about 4 to 6 carbon atoms, such as butanol or isobutyl alcohol. For example, by selecting a solvent in this way, the dicarboxylic acid compound contained as a free acid in the acidic aqueous phase can be efficiently acid-base extracted with the above-mentioned highly polar solvent such as a ketone.

[0065] The organic solvent used in the second solution formation step is not particularly limited, and examples thereof include low-polarity solvents, such as aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, and cyclodecane; halogenated aliphatic hydrocarbon solvents such as dichloromethane and chloroform; and aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene. A mixed solvent of these low-polarity organic solvents (hereinafter also referred to as low-polarity solvents) with an organic solvent with a higher polarity (hereinafter also referred to as high-polarity solvent) may also be used. For example, a mixed solvent of a low-polarity solvent selected from the above options and a high-polarity solvent described as a polar solvent, such as a ketone solvent, may be used, which contains 10 to 90% by mass of the low-polarity solvent, 30 to 70% by mass of the low-polarity solvent, or 40 to 60% by mass of the low-polarity solvent, based on the total mass, and the remaining components being high-polarity solvents.

[0066] In the solution-forming step, a mixed solution obtained by dissolving a dicarboxylic acid compound and a dihydroxy compound in a polar solvent is washed with an acidic aqueous solution in a washing step described below, and from the obtained organic layer, only the dicarboxylic acid compound can be selectively crystallized. Also, in the solution-forming step, a mixed solution obtained by dissolving a dicarboxylic acid compound and a dihydroxy compound in an organic solvent can be crystallized as a co-crystal of the dicarboxylic acid compound and the dihydroxy compound.

[0067] The amount of the solvent used in the solution formation step is preferably 0.01 to 100 g / g, more preferably 0.1 to 50 g / g, still more preferably 1.0 to 20 g / g, and particularly preferably 2.0 to 10 g / g, relative to the total amount of the dicarboxylic acid compounds or the total amount of the dicarboxylic acid compounds and the dihydroxy compounds.

[0068] The mixed solution prepared in the solution-forming step may contain only a dicarboxylic acid compound as the compound to be crystallized, or may contain a dicarboxylic acid compound and a dihydroxy compound. The ratio (molar ratio) of the dicarboxylic acid compound to the dihydroxy compound in the mixed solution is, for example, 100:0 to 10:90, preferably 80:20 to 15:85 or 70:30 to 20:80, more preferably 60:40 to 35:65 or 55:45 to 40:60, and even more preferably 50:50 to 40:60.

[0069] (Washing Step) The method for producing a dicarboxylic acid compound of the present invention may include a washing step of washing a mixed solution containing the dicarboxylic acid compound. In the washing step, the mixed solution containing the dicarboxylic acid compound may be washed with an acidic aqueous solution (first washing step), or the mixed solution may be washed with an organic solvent (second washing step).

[0070] The acidic aqueous solution used in the washing step can be an aqueous solution of an inorganic acid such as hydrochloric acid or nitric acid. The concentration of the inorganic acid in the aqueous solution is, for example, 0.1 M to 10 M, preferably 0.3 M to 5 M, and more preferably 0.5 M to 3 M. Alternatively, the acidic aqueous solution used in the washing step can be an aqueous solution of an organic acid such as toluenesulfonic acid, oxalic acid, maleic acid, or methanesulfonic acid. In this way, by using an acid with a higher acidity than the target dicarboxylic acid compound, such as BINOL-DC, as an acidic aqueous solution in the washing step, the salt of the dicarboxylic acid compound can be converted to a carboxylic acid, enabling efficient crystallization. The organic solvent used in the washing step can be the same as that used in the solution formation step, for example, an aliphatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, or cyclodecane, or an aromatic hydrocarbon solvent such as toluene, xylene, or mesitylene.

[0071] (Crystallization Step) The method for producing a dicarboxylic acid compound of the present invention includes at least a crystallization step of crystallizing a dicarboxylic acid compound. The crystallization step allows efficient production of a pure dicarboxylic acid compound from a mixed solution. Thus, the dicarboxylic acid compound obtained by the crystallization step is usually in a crystalline form. The mixed solution to be subjected to the crystallization step is obtained, for example, by adding a second solvent to the reaction solution obtained in the decomposition step described above. Specifically, the mixed solution for crystallization preferably contains a dicarboxylic acid compound, a dihydroxy compound, a first solvent, and a second solvent derived from the reaction solution described above. The mixed solution may further contain seed crystals, organic impurities, and depolymerized products thereof, etc.

[0072] The content of the dicarboxylic acid compound in the mixed solution for crystallization is preferably 1 to 35 mass %, more preferably 5 to 30 mass %, further preferably 5 to 25 mass %, and particularly preferably 10 to 25 mass %, based on the total mass of the mixed solution. When two or more dicarboxylic acid compounds are used, the total content thereof is preferably within the above range.

[0073] First Solvent The first solvent may be any of those described above. The first solvent typically dissolves a dicarboxylic acid compound and a dihydroxy compound. In this case, the solubility of the dicarboxylic acid compound in the first solvent at 25°C is preferably 0.01 g / 10 mL or more, more preferably 0.02 g / 10 mL or more, and even more preferably 0.05 g / 10 mL or more. The upper limit of the solubility of the dicarboxylic acid compound in the first solvent at 25°C is not particularly limited, but from the viewpoint of performing crystallization favorably, it is 3 g / 10 mL or less, preferably 2 g / 10 mL or less, and more preferably 1 g / 10 mL or less.

[0074] The content of the first solvent in the mixed solution for crystallization is preferably 0.1 to 10 g / g, more preferably 0.5 to 7.5 g / g, and even more preferably 0.75 to 5 g / g, relative to the total amount of the dicarboxylic acid compound. A content of the first solvent within the above range is preferred because a highly pure dicarboxylic acid compound can be obtained by crystallization. The content of the first solvent in the crystallization solution can be adjusted by, for example, distilling off the solvent after depolymerization. When a dihydroxy compound is also crystallized, the content of the first solvent in the mixed solution is preferably 0.1 to 10 g / g, more preferably 0.5 to 7.5 g / g, and even more preferably 0.75 to 5 g / g, relative to the total amount of the mixture of the dicarboxylic acid compound and the dihydroxy compound to be crystallized.

[0075] Second Solvent The second solvent is a solvent in which the difference between the solubility of the dicarboxylic acid compound in the first solvent at 25°C and the solubility of the dicarboxylic acid compound in the first solvent at 25°C (the solubility difference at 25°C) is preferably 0.1 g / 10 mL or more, more preferably 0.3 g / 10 mL or more, and even more preferably 0.4 to 10 g / 10 mL.

[0076] The second solvent is preferably selected such that the difference between the solubility of the dicarboxylic acid compound in the first solvent at 70°C and the solubility of the dicarboxylic acid compound in the second solvent at 70°C (the solubility difference at 70°C is preferably 0.1 g / 10 mL or more, more preferably 0.3 g / 10 mL or more, and particularly preferably 0.4 to 10 g / 10 mL).

[0077] The second solvent may be one that is also used in the solution formation step described above, and examples thereof include ketone solvents such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK), and cyclohexanone; ether solvents such as tetrahydrofuran, 1,3-dioxolane, and 1,4-dioxane; and alcohol solvents such as ethanol, propanol, isopropyl alcohol, butanol, and isobutyl alcohol. Of these, the second solvent is preferably a ketone solvent, and more preferably methyl ethyl ketone (MEK). These solvents may be used alone or in combination of two or more.

[0078] The type of dihydroxy compound to be crystallized together with the dicarboxylic acid compound can be determined by selecting the second solvent. For example, when the mixture of dihydroxy compounds contains 2,2'-bis(2-hydroxyethoxy)-6,6'-diphenyl-1,1'-binaphthalene (DP), 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BNE), and 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene (BPPEF), the solubility of DP in methyl ethyl ketone (MEK) at 25°C is 0.3 g / 10 mL, that of BNE is 0.75 g / 10 mL, and that of BPPEF is 4.5 g / 10 mL. Therefore, when MEK is used as the second solvent, the first hydroxy compound is DP, the other dihydroxy compounds are BNE and BPPEF, and the solubility difference at 25°C is 0.45 g / 10 mL.

[0079] The content of the second solvent in the crystallization solution is preferably 1.0 to 6.0 g / g, more preferably 0.3 to 5.0 g / g, and even more preferably 0.75 to 2 g / g, relative to the total amount of the dicarboxylic acid compound or the total amount of the mixture of the dicarboxylic acid compound and the dihydroxy compound. When the content of the second solvent is within the above range, a dicarboxylic acid compound with high purity can be obtained by crystallization, which is preferable.

[0080] The total content of the first solvent and the second solvent in the mixed solution for crystallization is preferably 1 to 10 g / g, more preferably 1.5 to 8.0 g / g, relative to the total amount of the dicarboxylic acid compound or the total amount of the mixture of the dicarboxylic acid compound and the dihydroxy compound. A total content of the first solvent and the second solvent of 1 g / g or more, for example 2 g / g or more, is preferred because the purity of the dicarboxylic acid compound can be increased. On the other hand, a total content of the first solvent and the second solvent of 10 g / g or less is preferred because the yield can be increased.

[0081] In one embodiment, the total content of the first solvent and the second solvent in the mixed solution for crystallization is preferably 2 g / g or more, more preferably 4 g / g or more, based on the total amount of the dicarboxylic acid compound or the total amount of the mixture of the dicarboxylic acid compound and the dihydroxy compound. The upper limit of the total content of the first solvent and the second solvent is preferably 10 g / g or less. When the total content of the first solvent and the second solvent is 2 g / g or more, the purity of the dicarboxylic acid compound can be increased, which is preferable.

[0082] The ratio of the content (g / g) of the first solvent to the content (g / g) of the second solvent in the mixed solution for crystallization (first solvent / second solvent) is preferably 0.8 to 10, more preferably 0.8 to 7, even more preferably 0.9 to 4, and particularly preferably 1 to 3. When the ratio (first solvent / second solvent) is within the above range, the purity of the dicarboxylic acid compound can be increased, which is preferable.

[0083] In the crystallization step, crystals of only the dicarboxylic acid compound may be crystallized from a mixed solution containing at least the dicarboxylic acid compound, or co-crystals of the dicarboxylic acid compound and the dihydroxy compound may be crystallized from the mixed solution. That is, the (co-)crystals obtained by the crystallization step may contain only the dicarboxylic acid compound, or may contain the dicarboxylic acid compound and the dihydroxy compound. The ratio (molar ratio) of the dicarboxylic acid compound to the dihydroxy compound in the (co-)crystals is, for example, 100:0 to 10:90, preferably 90:10 to 20:80 or 80:20 to 30:70, more preferably 75:25 to 40:60 or 70:30 to 45:55, and even more preferably 65:35 to 50:50.

[0084] In addition, in the crystallization step, seed crystals of a dicarboxylic acid compound or a dihydroxy compound may be added to the mixed solution. That is, in the crystallization step, seed crystals of only a dicarboxylic acid compound may be added to crystallize the dicarboxylic acid compound from the mixed solution. Furthermore, in cases where the mixed solution contains dicarboxylic acid compounds and dihydroxy compounds of the above-mentioned general formulas that have similar molecular structures, seed crystals of either a dicarboxylic acid compound or a dihydroxy compound may be added to the mixed solution to crystallize a co-crystal of a dicarboxylic acid compound and a dihydroxy compound.

[0085] The form of the seed crystal is not particularly limited, but is preferably a crystalline solvate. In this case, the compound that forms the crystalline solvate is not particularly limited, but is preferably a dicarboxylic acid compound of general formula (1-1) or (1-2), or a dihydroxy compound of general formula (2-1) or (2-2), and more preferably a dicarboxylic acid compound. In addition, the solvent that constitutes the solvate is not particularly limited, but is more preferably methanol, toluene, or methyl ethyl ketone. Furthermore, the content of the solvent in the crystalline solvate is preferably 0.3 to 1.5 moles per mole of the compound that forms the crystalline solvate. By using seed crystals in the form of a crystalline solvate, a dihydroxy compound with high purity can be produced. In this specification, the term "crystalline solvate" refers to a crystalline form that contains a solvent inside the crystal lattice of the seed crystal.

[0086] The ratio of the mode diameter to the median diameter of the seed crystals (mode diameter / median diameter) is preferably 2.0 or less, more preferably 1.0 to 1.6. A ratio (mode diameter / median diameter) of 2.0 or less is preferred because the resulting dicarboxylic acid compound can be highly pure and easily handled as bulk crystals. In this specification, "mode diameter" refers to the most frequent diameter exhibiting the highest frequency value, and is measured by particle size measurement using laser diffraction. Furthermore, "median diameter" refers to the particle size at 50% of the cumulative value in a cumulative particle size distribution, and is measured by particle size measurement using laser diffraction.

[0087] The aspect ratio of the seed crystal is preferably 1 to 8, and more preferably 1 to 3. In this specification, "aspect ratio" refers to the ratio (L / W) of the maximum crystal length L to the width W in the crystal. In this case, "maximum crystal length L" refers to the length of the crystal taken so that the crystal is at its longest in a crystal photograph taken with an optical microscope. Furthermore, "width W" refers to the length that forms an angle of 90 degrees with respect to the maximum crystal length and is the maximum length. The maximum crystal length L and width W are average values ​​calculated by measuring at least 30 crystals randomly selected from the optical microscope photograph.

[0088] The content of the seed crystals is preferably 0.001 to 1 mass%, more preferably 0.01 to 1 mass%, based on the total amount of the mixture of the dicarboxylic acid compounds or the total amount of the dicarboxylic acid compounds and the dihydroxy compound.

[0089] The content of the seed crystals is preferably 0.001 to 1 mass %, more preferably 0.005 to 0.5 mass %, and even more preferably 0.01 to 0.1 mass %, based on the total mass of the mixed solution as the crystallization solution.

[0090] In the crystallization step, it is usually preferable to heat and dissolve components such as the dicarboxylic acid compound and other dihydroxy compounds, and then cool and crystallize them. The heating temperature before crystallization varies depending on the solvent used, but is preferably 50 to 90°C, more preferably 60 to 85°C, and even more preferably 65 to 80°C.

[0091] The crystallization temperature, that is, the temperature at which crystals are formed, is not particularly limited, but is preferably -10 to 60°C, more preferably 0 to 50°C, and even more preferably 10 to 40°C.

[0092] The crystallization time is not particularly limited, but is preferably 5 minutes to 5 hours, more preferably 10 minutes to 3 hours, and even more preferably 30 minutes to 2 hours.

[0093] (Waste Resin Composition Treatment Step) The dicarboxylic acid compound production method of the present invention may include, for example, a step of treating a waste resin composition. The waste resin composition treatment step is usually carried out before the above-mentioned decomposition step, and provides a resin composition containing a polyester carbonate resin, a polyester resin, or the like, which is the target of the decomposition step.

[0094] In one embodiment, the process for treating the waste resin composition includes pulverizing a waste resin composition raw material to prepare a waste resin composition. Also, in one embodiment, the process for treating the waste resin composition includes removing metals from the waste resin composition raw material. In the process for treating the waste resin composition, both the pulverization and metal removal described above may be performed. In this case, the order of pulverization and metal removal is not particularly limited, but performing pulverization followed by metal removal is preferred because metal removal can be performed more efficiently.

[0095] (Waste Resin Composition Raw Material) The waste resin composition raw material is not particularly limited, but may be derived from molded products recovered after being used on the market as part of a product, defective products generated in the molding process, molded products (sprue, runner, gate, etc.) generated as ancillary to the molding process, defective products generated in the commercialization process, unused molded products that are no longer needed, etc. Among these, from the viewpoint of minimizing deterioration of the desired synthetic resin, those derived from defective products generated in the molding process, molded products (sprue, runner, gate, etc.) generated as ancillary to the molding process, and unused molded products that are no longer needed are preferred. From the viewpoint of acquisition efficiency, defective products generated in the molding process, molded products (sprue, runner, gate, etc.) generated as ancillary to the molding process are more preferred. Note that the above-mentioned molded products, etc. may be sorted, and only those containing organic impurities may be used as the waste resin composition raw material. For example, sprues may be sorted, and those that can be recycled as they are removed and used in products, and the remaining ones containing organic impurities may be used as the waste resin composition raw material. Furthermore, waste resin composition raw materials may be obtained by mixing those of different origins.

[0096] The shape of the waste resin composition raw material is not particularly limited, and examples thereof include powder, pellets, sheets, films, molded products, and the like, as well as discarded lenses, sheets, and films; defective products and burrs generated during manufacturing and / or molding processing; manufacturing waste; solids recovered from waste products using resin, and pulverized products thereof.

[0097] The longest diameter of the waste resin composition raw material is preferably 100 cm or less, more preferably 50 cm or less, and even more preferably 0.5 to 3 cm. If the longest diameter of the waste resin composition raw material is 100 cm or less, this is preferable because the energy required for pulverization is low. In this specification, the "longest diameter" means the average value of the diameters having the longest distance along the contour line of 200 randomly selected objects.

[0098] (Pulverization) The pulverization method is not particularly limited, and any of compression, impact, shear, and friction methods may be used.

[0099] Examples of crushers that can be used include coarse crushers such as jaw crushers, gyratory crushers, impact crushers, uniaxial crushers, and biaxial crushers; medium crushers such as roll crushers, edge runners, disintegrators, SAG (Semi-Autogenous Grinding) mills, crushing rolls, hammer mills, and roller mills; and fine crushers such as bead mills, ball mills, vibration ball mills, rod mills, jet mills, and planetary mills. Of these, coarse crushers are preferred, and uniaxial crushers and biaxial crushers are more preferred. Specific examples of crushers include high-power crushers 35-560, 35-720, 55-770, and 55-1050 (manufactured by Tanaka Corporation), and low-speed crushers KGA-250 and KGA-350 (manufactured by Kawata Corporation). The above-mentioned crushers may be used alone or in combination of two or more.

[0100] (Metal Removal) The method for removing metals is not particularly limited, and examples thereof include a method using magnetic force, a method using wind power, a method using a sieve, a method using specific gravity, and a method using buoyancy. Among these, a method using magnetic force (a method using a magnet, a method using a metal detector, etc.), a method using specific gravity, and a method using buoyancy (a method using salt water) are preferred. These methods may be used alone or in combination of two or more.

[0101] The metals to be removed include metals contained in plastic products, metals mixed in during the molding process, metals mixed in during the crushing process, and the like.

[0102] (Waste resin composition) The waste resin composition may be the waste resin composition raw material as it is, but is preferably one obtained by pulverizing the waste resin composition raw material, removing metals, etc. However, when pulverization and metal removal are not required in the waste resin composition raw material, it is preferable to use the waste resin composition raw material as it is as the waste resin composition. For example, when the size of the waste resin composition raw material is uniform, the longest diameter of the waste resin composition raw material is small (for example, the longest diameter is 5 cm or less), or no metal is contained, it is preferable not to perform the step of preparing the waste resin composition from the viewpoint of production costs.

[0103] The waste resin composition contains, for example, a desired synthetic resin and organic impurities. In this specification, the term "resin" refers to a resin having a weight-average molecular weight of 1,000 or more. In this specification, the term "weight-average molecular weight (Mw)" refers to the weight-average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0104] Desired Synthetic Resin The desired synthetic resin is, for example, a resin having a structural unit derived from a dicarboxylic acid compound of the above general formula (1-1) or (1-2), and may also be a resin having a structural unit derived from a dihydroxy compound of the above formula (2-1) or (2-2). Examples of the desired synthetic resin include polyester carbonate resin, polyester resin, polycarbonate (PC) resin, etc., and preferably polyester carbonate resin, polyester resin, etc.

[0105] At least two of the above-mentioned structural units may be contained in the synthetic resin to be treated contained in the waste resin composition. In this case, the structural units may contain two or more structural units represented by the same general formula, or may contain two or more structural units represented by different general formulas. In addition to the above-mentioned structural units, they may be combined with structural units of other polycarbonate resins, or with structural units of other resins (polyolefin resins, polyester resins), etc.

[0106] The weight average molecular weight (Mw) of the desired synthetic resin contained in the waste resin composition is not particularly limited, but is preferably 10,000 to 70,000, and more preferably 15,000 to 50,000. If the weight average molecular weight (Mw) of the desired synthetic resin is 10,000 or more, it is preferable because it can maintain appropriate strength as a molded product, such as a resin for an optical lens. On the other hand, if the weight average molecular weight (Mw) of the desired synthetic resin is 70,000 or less, it is preferable because it can maintain appropriate fluidity during resin molding and improve moldability.

[0107] The content of the desired synthetic resin in the waste resin composition is preferably 80% by mass or more, and more preferably 80 to 99% by mass, based on the mass of the waste resin composition. When the content of the desired synthetic resin is 80% by mass or more, it is preferable because the recycling efficiency is high.

[0108] Organic Impurities Examples of organic impurities include impurity resins and impurity compounds.

[0109] The impurity resins include thermoplastic resins other than the desired synthetic resin.

[0110] The thermoplastic resin is not particularly limited, and examples thereof include polyolefin resins (polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), polytetrafluoroethylene (PTFE), etc.), polyurethane (PU) resins, acrylic resins, polyester resins (polyethylene terephthalate (PET), polybutylene terephthalate (PBT)), polyamide (PA) resins, polyacetal resins, cyclic polyolefins (cycloolefin polymers), polyphenylene sulfide (PPS) resins, polysulfone resins, polyethersulfone resins, liquid crystal polymers (LCPs), polyether ether ketone (PEEK) resins, polyamide imide (PAI) resins, and copolymers of structural units of these resins (acrylonitrile-styrene copolymer resin (AS resin), acrylonitrile-butylene-styrene copolymer resin (ABS resin), etc.).

[0111] The above-mentioned structural units may be contained alone or in combination of two or more in the impurity resin. In addition, the above-mentioned structural units may be combined with structural units of other cyclic polyolefins, or with structural units of other resins (polyolefin resins, polyester resins), etc.

[0112] The weight average molecular weight (Mw) of the impurity resin is not particularly limited, but is preferably 1,000 to 3,000,000, more preferably 10,000 to 3,000,000, even more preferably 20,000 to 1,000,000, and particularly preferably 30,000 to 500,000. A weight average molecular weight (Mw) of the impurity resin of 1,000 or more is preferable because separation is facilitated. On the other hand, a weight average molecular weight (Mw) of the impurity resin of 3,000,000 or less is preferable because it is less likely to become a source of gel impurities when a trace amount of impurity resin is contaminated.

[0113] The content of impurity resins in the waste resin composition is preferably 50% by mass or less, more preferably 0.001 to 50% by mass, even more preferably 0.01 to 30% by mass, and particularly preferably 0.1 to 20% by mass, based on the total mass of the waste resin composition. A content of impurity resins of 50% by mass or less is preferred because it increases efficiency.

[0114] The impurity compounds are not particularly limited, but include monomers, dimers, copolymers, and oligomers of the above-mentioned impurity resins, aryl alcohols such as phenol, carbonate diesters such as diphenyl carbonate, and modified products of desired synthetic resins. In this specification, "impurity compounds" refers to organic compound impurities having a weight-average molecular weight of less than 1,000. Therefore, when the weight-average molecular weight of the modified recycled resin is 1,000 or more, the modified desired synthetic resin is classified as an impurity resin.

[0115] Shape of Waste Resin Composition The shape of the waste resin composition is not particularly limited, and examples thereof include powder, granules, rods, etc. The longest diameter of the waste resin composition is preferably 5 cm or less, more preferably 3 cm or less, even more preferably 0.001 to 3 cm, particularly preferably 0.01 to 2 cm, and extremely preferably 0.1 to 1 cm. A waste resin composition having a longest diameter of 5 cm or less is preferred from the viewpoints of ease of transportation, ease of depolymerization, etc.

[0116] 2. Method for Producing Recycled Resin The method for producing a recycled resin of the present invention includes a polymerization step of polymerizing the dicarboxylic acid compound of the above-mentioned formula (1-1) or formula (1-2). According to this method for producing a recycled resin, for example, a recycled resin such as a polyester resin or a polyester carbonate resin can be produced using a monomer compound derived from a resin composition recycled from the above-mentioned waste resin composition.

[0117] (Polymerization Step) Since the dicarboxylic acid compound is polymerized, any known polymerization technique can be employed in the polymerization step. In one embodiment, the recycled polyester resin can be produced by subjecting the dicarboxylic acid compound and the carbonate diester obtained by the above-described method to a solution condensation process in the presence or absence of a basic compound catalyst and / or a transesterification catalyst. Furthermore, in order to adjust the physical properties of the recycled resin, a dihydroxy compound can be used as a monomer together with the dicarboxylic acid compound produced from the waste resin composition, or the dihydroxy compound can be used alone. For example, in one embodiment, the recycled polyester carbonate resin can be produced by polymerizing the dicarboxylic acid compound and the dihydroxy compound obtained by the above-described method together with a carbonate diester in the presence or absence of a basic compound catalyst and / or a transesterification catalyst. Furthermore, the recycled polycarbonate resin can also be produced by polymerizing the dihydroxy compound that can be crystallized together with the dicarboxylic acid compound in the above-described method with a carbonate diester in the presence or absence of a basic compound catalyst and / or a transesterification catalyst.

[0118] The carbonic acid diester is not particularly limited, but examples thereof include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. Among these, diphenyl carbonate is preferred.

[0119] The amount of the diester carbonate compound used is preferably 0.97 to 1.20 mol, more preferably 0.98 to 1.10 mol, and even more preferably 1.00 to 1.10 mol, per mol of the dicarboxylic acid compound.

[0120] The basic compound catalyst includes, but is not limited to, alkali metal compounds, alkaline earth metal compounds, nitrogen-containing compounds, etc. The alkali metal compound includes, but is not limited to, organic acid salts, inorganic salts, oxides, hydroxides, hydrides, and alkoxides of alkali metals. Specific examples include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenylborohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, disodium salt, dipotassium salt, dicesium salt, or dilithium salt of bisphenol A, and sodium salt, potassium salt, cesium salt, or lithium salt of phenol.

[0121] The alkaline earth metal compound is not particularly limited, and examples thereof include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, and alkoxides of alkaline earth metal compounds. Specific examples include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, and magnesium phenylphosphate.

[0122] The nitrogen-containing compound is not particularly limited, but examples thereof include quaternary ammonium hydroxides, salts thereof, amines, etc. Specific examples include quaternary ammonium hydroxides having an alkyl group, an aryl group, etc., such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide; tertiary amines such as triethylamine, dimethylbenzylamine, and triphenylamine; secondary amines such as diethylamine and dibutylamine; primary amines such as propylamine and butylamine; imidazoles such as 2-methylimidazole, 2-phenylimidazole, and benzimidazole; ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate.

[0123] Examples of the transesterification catalyst include salts of zinc, tin, zirconium, lead, etc. Specific examples include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin(II) chloride, tin(IV) chloride, tin(II) acetate, tin(IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead(II) acetate, and lead(IV) acetate.

[0124] The above-mentioned basic compound catalysts and transesterification catalysts may be used alone or in combination of two or more kinds.

[0125] The amount of the basic compound catalyst and the transesterification catalyst (total amount when used in combination) used is 1 × 10 per mole of the dicarboxylic acid compound. －９ ~1 x 10 －３ mol, preferably 1×10 －７ ~1 x 10 －４ More preferably, it is moles.

[0126] In a polymerization process such as a melt polycondensation method, it is desirable to melt monomer components such as a dicarboxylic acid compound and a carbonic acid diester in a reaction vessel and then carry out the reaction in a state in which a monohydroxy compound that may be produced remains. In order to retain the monohydroxy compound, the pressure can be controlled by, for example, blocking the reaction apparatus or reducing or increasing the pressure.

[0127] The recycled resin obtained by the above method can be suitably used in plastic products.

[0128] Hereinafter, the present invention will be described in detail with reference to examples, but the technical scope of the present invention is not limited thereto. In the examples, "%" represents "% by mass" unless otherwise specified. (Polymerization Example 1 of Polyester Carbonate) As raw materials, 3,290 g (8.79 mol) of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BNE) represented by the following structural formula, 7,000 g (13.0 mol) of 9,9-bis[6-(2-hydroxyethoxy)-2-naphthyl]fluorene (BNEF, also abbreviated as NOLE) represented by the following structural formula, and 2,2'-([1,1'-binaphthalene]-2,2' A 50-liter reactor equipped with a stirrer and a distillation device was charged with 6,610 g (16.4 mol) of 2,4-diylbis(oxy)acetoacetic acid (BINOL-DC), 1,380 g (6.44 mol) of diphenyl carbonate (DPC), 1.30 g of tris(2,4-pentanedionato)aluminum(III) as a catalyst, and 1.63 mL of diethyl (4-methylbenzyl)phosphonate, and the inside of the reactor was purged with nitrogen.

[0129] Stirring of the reaction system was initiated under a nitrogen atmosphere of 760 Torr, and the system was heated to 200°C over 20 minutes. After adjusting the degree of vacuum of the reaction system to 300 Torr over 20 minutes, the temperature was raised to 240°C over 40 minutes, and the system was maintained at 240°C and 300 Torr for 10 minutes to carry out a transesterification reaction. The pressure was returned to normal with nitrogen gas, and water was recovered from the trap. The system was then adjusted again to conditions of 240°C and 300 Torr, and the reaction system was maintained for 10 minutes. Subsequently, the temperature of the reaction system was raised to 250°C over 70 minutes, while the degree of vacuum was adjusted to 50 Torr over 50 minutes. The degree of vacuum was then further adjusted to 1 Torr or less over 20 minutes, and a polymerization reaction was carried out for 30 minutes under stirring at 250°C and 1 Torr or less. After completion of the reaction, nitrogen was introduced into the reactor to pressurize the reaction system, and the resulting polyester carbonate resin was pelletized and extracted to obtain a polyester carbonate resin.

[0130] (Mixed Liquid Preparation Example 1) A reactor equipped with a stirrer and a cooling tube was charged with 100 parts by mass of the polyester carbonate resin obtained in Polymerization Example 1, 88 parts by mass of a 48% by mass aqueous sodium hydroxide solution, and 734 parts by mass of toluene as a first solvent, and the mixture was allowed to react under reflux for 3 hours. This reaction hydrolyzed the polyester carbonate resin into the raw material monomers (dihydroxy compound and dicarboxylic acid compound). The reaction solution was then cooled to a temperature of 80-85°C, and 155 parts by mass of 35% hydrochloric acid and 30 parts by mass of ion-exchanged water were added. After stirring and allowing to stand, the aqueous phase was separated, the organic phase was washed with ion-exchanged water, and the toluene was partially removed by distillation. Subsequently, methyl ethyl ketone (MEK), a second solvent, was added to an amount equal to the weight of toluene, and the dihydroxy compound and dicarboxylic acid compound were completely dissolved while controlling the temperature to 70-75°C, yielding a mixed liquid (organic).

[0131] (Mixed Solution Preparation Example 2) 100 parts by mass of the polyester carbonate resin obtained in Polymerization Example 1, 88 parts by mass of a 48% by mass aqueous sodium hydroxide solution, and 734 parts by mass of toluene as a first solvent were charged into a reactor equipped with a stirrer and a cooling tube, and the mixture was allowed to react under reflux for 3 hours. Through this reaction, the polyester carbonate resin was hydrolyzed into the raw material monomers (dihydroxy compound and dicarboxylic acid compound). The reaction solution was then cooled to a temperature of 80-85°C, and 188 parts by mass of ion-exchanged water was added. After stirring and allowing to stand, the organic phase was separated and removed, yielding a mixed solution (water-soluble). BNE and NOLE were dissolved in the organic layer, and a salt of BINOL-DC was dissolved in the aqueous layer.

[0132] Mixed Solution Preparation Example 3 Mixed solution a was prepared by mixing 3.34 g of BINOL-DC, 1.95 g of BNE, 3.79 g of NOLE, and 40.00 g of toluene (amount added per 1 g of total dihydroxy compounds and dicarboxylic acid compounds (BINOL-DC + BNE + NOLE): 4.00 g). Mixed solution a was further mixed with 40.00 g of MEK (amount added per 1 g of total dihydroxy compounds and dicarboxylic acid compounds (BINOL-DC + BNE + NOLE): 4.00 g), to prepare mixed solution b. Subsequently, the temperature of mixed solution b was controlled at 70 to 75° C. to completely dissolve the dihydroxy compounds and dicarboxylic acid compounds, thereby obtaining mixed solution c (organic). The molar ratio of BINOL-DC / BNE / NOLE contained in the mixed solution c was measured and found to be 43 / 23 / 34.

[0133] The molar ratios of the above-mentioned components, i.e., the molar ratios of the dicarboxylic acid compound, dihydroxy compound, etc., were analyzed by high performance liquid chromatography (HPLC). Detailed analysis conditions are as follows, and the molar ratios of the components described below were also analyzed under the same conditions. Apparatus: Agilent Technologies 1260 Infinity Column: TOSOY TSK-GEL ODS-80-Ts (5 μm, 4.6 mmφ x 250 mm) Eluent: 0 min acetonitrile / water = 46.3 / 53.7 (vol%); 15 min acetonitrile / water = 46.3 / 53.7 (vol%); 30 min acetonitrile / water = 95 / 5 (vol%); 40 min acetonitrile / water = 95 / 5 (vol%) Flow rate: 1 mL / min Column temperature: 25°C Measurement wavelength: 254 nm Injection volume: 5 μm Sample concentration: 10 mg / 10 mL (acetonitrile solvent) Calculation method: Calculated based on the peak area % (peak intensity) of the obtained chromatogram.

[0134] Example 1 The mixed solution c obtained in Preparation Example 3 of the mixed solution described above was kept at 30°C, and 10 mg of BINOL-DC, which had been prepared separately, was added as seed crystals. The mixture was then cooled to approximately room temperature by air cooling, and then further cooled to 10°C in a water bath and stirred for 1 hour to produce crystals (crystallization step). The precipitate was filtered and washed with toluene. The washed precipitate was dried to obtain 0.69 g of crystals of a dihydroxy compound and a dicarboxylic acid compound. The molar ratio of BINOL-DC / BNE / NOLE in the obtained crystals was measured, and the molar ratio was found to be 62 / 38 / 0. The recovery rate of the crystals was calculated using the following formula and was found to be 13%. This recovery rate is a value calculated assuming that all of the crystals of the dihydroxy compound and the dicarboxylic acid compound are BINOL-DC and BNE. =0.69g / (3.34g+1.95g)×100 =13%

[0135] (Mixture Preparation Example 4) 0.167 g of BINOL-DC, 0.097 g of BNE, and 0.189 g of NOLE were dissolved in 20.00 mL of dichloromethane and 10.00 mL of methanol, and then 20 mL of 1 M aqueous sodium hydroxide solution was added to the resulting mixture. The mixture was stirred and allowed to stand, and then the organic phase was separated to obtain a mixture (water-soluble). Here, BNE and NOLE were dissolved in the organic layer, and a salt of BINOL-DC was dissolved in the aqueous layer.

[0136] Example 2 The mixed solution (water-soluble) containing a salt of BINOL-DC obtained in Mixture Preparation Example 4 above was washed with dichloromethane. After removing the dichloromethane, dichloromethane was added again to the aqueous phase, and 25 mL of 1 M hydrochloric acid was added to acidify the aqueous phase. After stirring and allowing to stand, the aqueous phase was separated, and the organic phase was washed with ion-exchanged water. Dichloromethane was distilled off from the organic phase to obtain 0.054 g of crystals of a dicarboxylic acid compound (BINOL-DC). The molar ratio of BINOL-DC / BNE / NOLE in the obtained crystals was measured, and the molar ratio was found to be 100 / 0 / 0. The recovery rate was calculated using the following formula and was found to be 32%. =0.054g / 0.167g×100 =32%

[0137] Example 3 The mixed solution (water-soluble) containing BINOL-DC salt obtained in Mixture Preparation Example 4 was washed with dichloromethane. After removing the dichloromethane, 25 mL of 1 M hydrochloric acid was added to the mixed solution to acidify the aqueous phase, and MEK (methyl ethyl ketone) was then added to the aqueous phase. In this way, the free acid of BINOL-DC was generated from the BINOL-DC salt by adding an acid, and then MEK, which is more polar than dichloromethane, was added to the mixed solution, allowing BINOL-DC to be easily extracted. After stirring and allowing to stand, the aqueous phase was separated, and the organic phase was washed with ion-exchanged water. MEK was distilled off from the organic phase to obtain 0.141 g of dicarboxylic acid compound crystals. The molar ratio of BINOL-DC / BNE / NOLE in the obtained crystals was measured, and the molar ratio was found to be 100 / 0 / 0. The recovery rate was calculated using the following formula and was found to be 84%. =0.141g / 0.167g×100 =84%

[0138] According to the above-described examples, cocrystals of a dicarboxylic acid compound and a dihydroxy compound can be obtained from a mixture of a dicarboxylic acid compound and a dihydroxy compound through a relatively simple procedure (see, for example, Example 1). Furthermore, by adjusting the conditions for crystallizing the crystals from the above-described mixture, a pure dicarboxylic acid compound can also be obtained as crystals (see, for example, Examples 2 and 3). The mixtures used in these examples (see, for example, Mixed Liquid Preparation Examples 3 and 4) were obtained, for example, by decomposing a polyester carbonate resin (see, for example, Mixed Liquid Preparation Examples 1 and 2). Therefore, it was confirmed that dicarboxylic acid compounds or dihydroxy compounds can be recovered and reused from polyester carbonate resins that may be contained in waste resin compositions, etc. By utilizing such a method for producing a monomer compound, it is possible to reuse resin compositions from waste materials including polyester resins, polycarbonate resins, etc., and recycle the dicarboxylic acid compounds and dihydroxy compounds that were used as raw materials. Furthermore, the recycled monomer compounds can be polymerized again to produce recycled resins. In particular, monomer compounds obtained as pure crystals can achieve efficient polymerization reactions without the need for further purification processes.

Claims

1. A method for producing a dicarboxylic acid compound represented by the following general formula (1-1) or (1-2), comprising a crystallization step of crystallizing at least the dicarboxylic acid compound from a mixed liquid containing the dicarboxylic acid compound and a dihydroxy compound represented by the following general formula (2-1) or (2-2): (In general formula (1-1), R ａ１ and R ｂ１ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ１ R is selected from the group consisting of ｈ１ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent; X １ represents a single bond or an optionally substituted fluorene group; A １ and B １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; １ and n １ each independently represents an integer of 0 to 6; １ and b １ each independently represents an integer of 0 to 10; １ ' and R １ '' are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. (In general formula (1-2), R ａ２ and R ｂ２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ２ R is selected from the group consisting of ｈ２ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent; X ２ represents a single bond, a fluorene group which may have a substituent, or any one of the structural formulae represented by the following formulae (8) to (15), (In formulas (8) to (15), R ６１ , R ６２ , R ７１ , R ７２ , R ８１ and R ８２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 30 carbon atoms which may have a substituent, or R ６１ and R ６２ , or R ７１ and R ７２ are bonded to each other to form a carbon ring or hetero ring having 1 to 20 carbon atoms which may have a substituent; ２ and B ２ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; ２ and n ２ each independently represents an integer of 0 to 6; ２ and b ２ each independently represents an integer of 0 to 10; ２ ' and R ２ '' are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. (In general formula (2-1), R ｃ and R ｄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ３ R is selected from the group consisting of ｈ３ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent; １ represents a single bond or an optionally substituted fluorene group; C １ and D. １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; p and q each independently represent an integer of 0 to 6; and c and d each independently represent an integer of 0 to 10. (In general formula (2-2), R ｅ and R ｆ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent; ２ represents a single bond, a fluorene group which may have a substituent, or any one of the structural formulae represented by the following formulae (8) to (15), (In formulas (8) to (15), R ６１ , R ６２ , R ７１ , R ７２ , R ８１ and R ８２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 30 carbon atoms which may have a substituent, or R ６１ and R ６２ , or R ７１ and R ７２ are bonded to each other to form a carbon ring or hetero ring having 1 to 20 carbon atoms which may have a substituent, and r and s each independently represent an integer of 0 to 5,000. ２ and F ２ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; each of t and u independently represents an integer of 0 to 4; and each of e and f independently represents an integer of 0 to 10.

2. The method for producing a dicarboxylic acid compound according to claim 1, further comprising a first washing step of washing the mixed liquid containing the dicarboxylic acid compound with an acidic aqueous solution.

3. The method for producing a dicarboxylic acid compound according to claim 1, further comprising a first solution-forming step of dissolving the dicarboxylic acid compound in a polar solvent to obtain the mixed liquid.

4. The method for producing a dicarboxylic acid compound according to claim 3, wherein in the first solution formation step, the dicarboxylic acid compound and the dihydroxy compound are dissolved in a polar solvent to obtain the mixed solution, and in the crystallization step, crystals of only the dicarboxylic acid compound are crystallized from the mixed solution.

5. The method for producing a dicarboxylic acid compound according to claim 1, further comprising a second washing step of washing the mixture containing the dicarboxylic acid compound with an organic solvent.

6. The method for producing a dicarboxylic acid compound according to claim 1, further comprising a second solution-forming step of dissolving the dicarboxylic acid compound in an organic solvent to obtain the mixed liquid.

7. The method for producing a dicarboxylic acid compound according to claim 6, wherein in the second solution formation step, the dicarboxylic acid compound and the dihydroxy compound are dissolved in an organic solvent to obtain the mixed solution, and in the crystallization step, a co-crystal of the dicarboxylic acid compound and the dihydroxy compound is crystallized from the mixed solution.

8. A method for producing a dicarboxylic acid compound according to claim 1, further comprising a decomposition step of decomposing a polyester carbonate resin and / or a polyester resin having a structural unit derived from a dicarboxylic acid compound represented by at least the following general formula (1-1') or the following general formula (1-2') to obtain the dicarboxylic acid compound represented by the general formula (1-1) or the general formula (1-2). (The symbols in formula (1-1') have the same meanings as those in formula (1-1) above.) (The symbols in formula (1-2') have the same meanings as those in formula (1-2) above.) 9. The method for producing a dicarboxylic acid compound according to claim 8, wherein in the decomposition step, the polyester carbonate resin and / or polyester resin is dissolved in a first solvent and treated with an alkaline solution to obtain a reaction solution containing the dicarboxylic acid compound of formula (1-1) or formula (1-2) and the first solvent, and in the crystallization step, the dicarboxylic acid compound is crystallized from a crystallization mixture obtained by adding a second solvent to the reaction solution, and the difference between the solubility of the dicarboxylic acid compound in the first solvent at 25°C and the solubility of the dicarboxylic acid compound in the second solvent at 25°C is 0.1 g / 10 mL or more.

10. The method according to claim 9, wherein the content of the first solvent in the crystallization mixture is 0.1 to 10 g / g based on the total amount of the mixture of dicarboxylic compounds.

11. The method according to claim 9, wherein the content of the second solvent in the crystallization mixture is 0.3 to 3 g / g based on the total amount of the mixture of dicarboxylic compounds.

12. The method according to claim 9, wherein the total content of the first solvent and the second solvent in the crystallization mixture is 1 to 10 g / g based on the total amount of the dicarboxylic acid compound.

13. The method according to claim 9, wherein the ratio of the content (g / g) of the first solvent to the content (g / g) of the second solvent in the crystallization mixture (first solvent / second solvent) is 0.8 to 10.

14. The method according to claim 1, wherein in the crystallization step, seed crystals of the dicarboxylic acid compound or the dihydroxy compound are added to the mixed liquid to crystallize a co-crystal of the dicarboxylic acid compound and the dihydroxy compound.

15. A method for producing a dicarboxylic acid compound represented by the following general formula (1-1) or the following general formula (1-2), comprising at least a crystallization step of crystallizing the dicarboxylic acid compound from a mixed liquid containing the dicarboxylic acid compound. (In general formula (1-1), R ａ１ and R ｂ１ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ１ R is selected from the group consisting of ｈ１ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent; X １ represents a single bond or an optionally substituted fluorene group; A １ and B １ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; １ and n １ each independently represents an integer of 0 to 6; １ and b １ each independently represents an integer of 0 to 10; １ ' and R １ '' are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. (In general formula (1-2), R ａ２ and R ｂ２ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and -C≡C-R ｈ２ R is selected from the group consisting of ｈ２ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent; X ２ represents a single bond or an optionally substituted fluorene group; A ２ and B ２ each independently represents an alkylene group having 1 to 5 carbon atoms which may have a substituent; ２ and n ２ each independently represents an integer of 0 to 6; ２ and b ２ each independently represents an integer of 0 to 10; ２ ' and R ２ '' are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent.

16. A method for producing a recycled resin, comprising a polymerization step of polymerizing a dicarboxylic acid compound produced by the method according to any one of claims 1 to 15.

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