Method for producing thermoplastic resin

Abstract

Cleaning of equipment for producing resin is not entirely sufficient. For example, it is not easy to thoroughly clean a reactor after a polymerization reaction using SPG or the like, which has a relatively high vapor pressure, as a monomer. Therefore, there have been concerns that target ratios of constituent units may not be achieved in resins obtained after a polymerization reaction due to the inclusion of impurities remaining in the reactor, etc., and that this may result in clogging of distillation devices and piping.　As a means for solving the abovementioned problems, provided is the following method for producing a thermoplastic resin.　A method for producing a thermoplastic resin in which a second thermoplastic resin (A) is produced after polymerizing a first thermoplastic resin (S) including a structural unit derived from spiroglycol (SPG) or an SPG derivative, the method including a cleaning step (a) in which a reactor used in the production of the first thermoplastic resin (S) is cleaned with a carbonate ester and then with an aryl alcohol.

Description

Thermoplastic resin manufacturing method

[0001] The present invention relates to a method for producing a thermoplastic resin, and more particularly to a method for producing a thermoplastic resin which includes a step of cleaning a polymerization reactor.

[0002] Spiroglycol (SPG) is a compound having a spiro ring in the molecule, and its derivatives generally have excellent thermal stability, etc. SPG is widely used as a raw material monomer for polymers such as polyester and polyurethane, an additive for resins, etc. (See, for example, Patent Document 1).

[0003] It is also known to clean the inside of an apparatus for producing a resin by polymerizing a monomer (see, for example, Patent Documents 2 to 4).

[0004] Patent Document 1: WO2020 / 162533 Patent Document 2: JP 2005-42014 A Patent Document 3: JP 2012-31298 A Patent Document 4: JP 2008-195918 A

[0005] Even with conventional methods, cleaning of resin production equipment has not always been sufficient. For example, in polymerization equipment such as a reactor, a distillation device (a distillation pipe or a cooling tower), and piping after a polymerization reaction using SPG, which has a relatively high vapor pressure, as a monomer, there is a risk of SPG monomer, SPG oligomers, etc. adhering to these devices, and it has not been easy to reliably clean these devices. For this reason, particularly in polymerization equipment in which a polymerization reaction has been carried out over a long period of time, there have been concerns, for example, that the molar ratio of raw material monomers, which had been accurately adjusted in advance, will not be accurately reflected in the ratio of constituent units of the resulting resin due to the inclusion of remaining impurities, and that clogging will occur in the distillation device, piping, etc. of the polymerization equipment.

[0006] Furthermore, polymerization equipment for industrially producing resins is usually large, and it is difficult to frequently disassemble and clean such polymerization equipment, such as a reaction apparatus, etc. Therefore, it is not easy to reliably remove impurities that may remain after a polymerization reaction, particularly in a large-scale polymerization apparatus, and the above-mentioned problem could not be solved by a simple method.

[0007] The present invention includes, for example, the following: [1] A method for producing a second thermoplastic resin (A) after polymerizing a first thermoplastic resin (S) containing a structural unit derived from spiroglycol (SPG) or an SPG derivative, the method comprising: a cleaning step (a), in which the reactor used in the production of the first thermoplastic resin (S) is cleaned with a carbonate ester and then an aryl alcohol in the cleaning step (a). [2] The method for producing a thermoplastic resin according to the above item [1], further comprising an unloading step of unloading the first thermoplastic resin (S) from the reactor before carrying out the cleaning step (a). [3] The method for producing a thermoplastic resin according to the above item [1] or [2], for example, the above item [1], in which the carbonate ester and the aryl alcohol are used under conditions below their respective boiling points in the cleaning step (a). [4] The method for producing a thermoplastic resin according to any one of [1] to [3] above, for example, [1] above, wherein in the washing step (a), at least one of spiroglycol (SPG), an SPG derivative, and an oligomer derived from SPG or an SPG derivative remaining in the reactor is to be washed.

[0008] [5] The method for producing a thermoplastic resin according to any one of [1] to [4] above, for example, the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method [8] The method for producing a thermoplastic resin according to the above-mentioned [6] or [7], for example, the method according to the above-mentioned [6], wherein the steps (a) to (c) are repeated. [9] The method for producing a thermoplastic resin according to the above-mentioned [8], wherein the steps (a) to (c) are repeated until the content of spiro glycol or SPG derivative in the distillate measured in the analysis step (c) becomes equal to or less than a predetermined target value.

[0009]

[10] The method for producing a thermoplastic resin according to any one of the above [1] to [9], for example, the above [1], wherein the reactor is equipped with a distillation and cooling device.

[11] The method for producing a thermoplastic resin according to any one of the above [1] to

[10] , for example, the above [1], wherein the SPG derivative is represented by the following formula (I): (In formula (I), R １ and R ２are each independently selected from an aliphatic alkyl group having 1 to 10 carbon atoms and an alicyclic alkyl group having 4 to 12 carbon atoms, both of which have a hydroxyl group and may be substituted with other substituents.)

[12] The method for producing a thermoplastic resin according to any one of [1] to

[11] above, for example, [1] above, wherein the first thermoplastic resin is a polycarbonate resin (S).

[13] The method for producing a thermoplastic resin according to

[12] above, wherein the polycarbonate resin (S) further contains a structural unit derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (Bis-TMC) and / or a structural unit derived from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF).

[14] The method for producing a thermoplastic resin according to any one of [1] to

[13] above, for example, [1] above, wherein the second thermoplastic resin (A) is a polyester, a polycarbonate, or a polyester / polycarbonate copolymer.

[0010] According to the present invention, a reactor or the like used in a polymerization reaction using at least SPG or the like as a monomer can be cleaned by a simple method, thereby eliminating the adverse effects of impurities that tend to volatilize and remain, such as SPG and SPG-derived oligomers. For example, after the production of a thermoplastic resin containing SPG-derived structural units, the thermoplastic resin obtained by a polymerization reaction using the same polymerization equipment such as a reactor can be reliably prevented from being contaminated by the above-mentioned impurities, from causing unexpected changes in the monomer ratio, from causing clogging in the polymerization equipment such as a reactor, and the like.

[0011] FIG. 1 is a diagram illustrating a schematic example of a reactor of a polymerization apparatus, which is a main object to be cleaned in a cleaning step.

[0012] Preferred embodiments of the present invention are described in detail below. The present invention relates to a production method for producing a second thermoplastic resin (A) after polymerizing a first thermoplastic resin (S) containing structural units derived from spiroglycol (SPG) or a derivative thereof. The production method for the thermoplastic resin (A) of the present invention includes at least a cleaning step (a). The cleaning step (a) is a step of cleaning a reactor used in the production of the first thermoplastic resin (S) using SPG or the like as a monomer, and the reactor is preferably cleaned with a carbonate ester and then an aryl alcohol in that order.

[0013] <1. First thermoplastic resin (S)> 1-1. Types and structural units of the first thermoplastic resin (S) The first thermoplastic resin contains at least a structural unit derived from spiro glycol (SPG) or a derivative thereof. Spiro glycol (3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane) is a diol compound having a spiro ring in the molecule.

[0014] The monomer compound used in producing the first thermoplastic resin may also include a derivative of SPG, such as an isomer of spiroglycol or a spiroglycol having a substituent, and a specific example of the SPG derivative is a compound represented by the following formula (1): In formula (I), R １ and R ２ are each independently selected from aliphatic alkyl groups having 1 to 10 carbon atoms and alicyclic alkyl groups having 4 to 12 carbon atoms, each of which has a hydroxyl group and may be substituted with other substituents. １ and R ２ are independently selected from aliphatic alkyl groups having 1 to 10 carbon atoms which contain at least one hydroxyl group and may have other substituents, and alicyclic alkyl groups having 4 to 12 carbon atoms which contain at least one hydroxyl group and may have other substituents.

[0015] R in formula (1) １ and R ２ Preferably, R has one hydroxyl group.１ and R ２ is preferably an aliphatic alkyl group having 1 to 10 carbon atoms, more preferably an aliphatic alkyl group having 2 to 8 carbon atoms or 2 to 6 carbon atoms, and even more preferably an aliphatic alkyl group having 3 to 8 carbon atoms or 3 to 6 carbon atoms, such as an optionally substituted t-butyl group having one hydroxyl group.

[0016] The above-mentioned substituents are each independently selected from halogen, a hydroxyl group, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms, etc., and when an alkyl group, an alkenyl group, or an aryl group is contained as a substituent, the above-mentioned R １ and R ２ The number of carbon atoms in the formula is the total number of carbon atoms including the carbon atoms of the substituents.

[0017] Although the type of the first thermoplastic resin is not particularly limited, the first thermoplastic resin is, for example, a polycarbonate resin, a polyester resin, a polyester / polycarbonate resin, etc. The first thermoplastic resin is preferably a polycarbonate resin.

[0018] Examples of the first thermoplastic resin include, in addition to the above-mentioned SPG-based monomer compounds, thermoplastic resins containing structural units derived from bisphenol compounds, fluorene-based compounds, etc. Examples of bisphenol compounds used as monomers in producing the first thermoplastic resin include bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC (Bis-TMC), bisphenol Z, etc., and a preferred specific example is bisphenol TMC (Bis-TMC).

[0019] Furthermore, examples of the fluorene compound used as a monomer in the production of the first thermoplastic resin include 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-2-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-2-ethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-2-ethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-ethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-2-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-2-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-2-isobutylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert Examples of suitable fluorenes include 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene, 9,9-bis(4-(6-hydroxy-3-oxapentyloxy)phenyl)fluorene, and 9,9-bis(4-(9-hydroxy-3,6-dioxaoctyloxy)phenyl)fluorene, and a preferred example is 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF). The first thermoplastic resin preferably has, for example, a structural unit derived from an SPG monomer (SPG structural unit), a bisphenol structural unit derived from Bis-TMC or the like, and / or a fluorene structural unit derived from BPEF or the like.

[0020] In the first thermoplastic resin, the proportion of SPG structural units based on the number of moles of all structural units is, for example, 5 to 50 mol%, 10 to 60 mol%, or 15 to 60 mol%, preferably 10 to 35 mol%, 10 to 40 mol%, or 15 to 50 mol%, more preferably 15 to 30 mol%. In the first thermoplastic resin, the proportion of bisphenol structural units based on the number of moles of all structural units is, for example, 5 to 50 mol%, 10 to 60 mol%, preferably 10 to 40 mol% or 15 to 50 mol%, more preferably 20 to 40 mol%. Furthermore, in the first thermoplastic resin, the proportion of fluorene structural units based on the number of moles of all structural units is, for example, 20 to 80 mol%, preferably 30 to 70 mol%, more preferably 35 to 60 mol%.

[0021] 1-2. SPG, a by-product in the production of the first thermoplastic resin (S), is a compound with a relatively high vapor pressure. Therefore, as described above, after a polymerization reaction using an SPG-based monomer compound or the like, SPG, SPG derivatives, oligomers thereof, and the like may adhere to the upper part of the reactor used in the polymerization reaction, the distillation device (distillation pipe or cooling tower), and the like. The above-mentioned oligomers derived from SPG may include, for example, those represented by the following formulas (2-1) and (2-2).

[0022] 1-3. Method for Producing First Thermoplastic Resin (S) The first thermoplastic resin (S) can be produced by a conventional method. For example, when producing a polycarbonate resin as the first thermoplastic resin (S), it can be produced by reacting an SPG compound, a bisphenol compound, or a fluorene compound as a monomer that derives each of the above-mentioned structural units, with a compound such as a dihydric phenol that induces a terminal structure, and a carbonate ester. Known methods, such as the direct reaction of a bisphenol such as a monohydric phenol with phosgene (phosgene method), or the transesterification of a bisphenol with a carbonate compound (transesterification method), can be employed. As the carbonate compound in the transesterification reaction, bisaryl carbonates such as diphenyl carbonate; bisalkyl carbonates such as dimethyl carbonate and dibutyl carbonate; monoaryl monoalkyl carbonates, and the like, can be suitably used.

[0023] In the phosgene method, the above-mentioned monomer compound and phosgene are usually reacted in the presence of, for example, an acid binder and a solvent, and it is preferable to further add a terminal terminator such as a monohydric phenol to terminate the reaction. As the acid binder, for example, pyridine or an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used, and as the solvent, for example, methylene chloride or chloroform is used. Furthermore, in order to promote the condensation polymerization reaction, it is preferable to use a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt such as benzyltriethylammonium chloride.

[0024] The reaction temperature is usually in the range of 0 to 150°C, preferably 5 to 40°C. The reaction time varies depending on the reaction temperature, but is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours. It is also desirable to maintain the pH of the reaction system at 10 or higher during the reaction.

[0025] On the other hand, in the transesterification method, for example, the above-mentioned monomer compound, a diol compound such as a dihydric phenol, and a bisaryl carbonate are mixed and reacted, for example, under reduced pressure at high temperature. Examples of the bisaryl carbonate include bisaryl carbonates such as diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Two or more of these compounds can also be used in combination.

[0026] The reaction temperature is typically 150 to 350°C, preferably 200 to 300°C, and the final pressure reduction is preferably 1 mmHg or less, allowing phenols derived from the bisarylcarbonate produced by the transesterification reaction to be distilled out of the system. The reaction time varies depending on the reaction temperature and the pressure reduction, but is typically about 1 to 24 hours. The reaction is preferably carried out under an inert gas atmosphere such as nitrogen or argon. If desired, the reaction may be carried out using a small amount of a molecular weight regulator other than the monohydric phenol or other compound that induces a terminal structure, or by adding an antioxidant or branching agent.

[0027] <2. Second Thermoplastic Resin (A)> 2-1. Type of Second Thermoplastic Resin (A) The type of the second thermoplastic resin (A) produced after the first thermoplastic resin (S) is not particularly limited. Examples of the second thermoplastic resin include a polycarbonate resin, a polyester resin, and a polyester / polycarbonate resin. The second thermoplastic resin is preferably a polycarbonate resin.

[0028] 2-2. Structural Units of the Second Thermoplastic Resin (A) The structural units of the second thermoplastic resin (A) are usually not completely identical to the structural units of the first thermoplastic resin (S), but may contain structural units derived from the above-mentioned SPG-based monomer compound. Furthermore, the second thermoplastic resin (A) may be formed from the same structural units as the first thermoplastic resin (S). However, the second thermoplastic resin (A) preferably does not contain structural units derived from an SPG-based monomer compound. When the reactor used for the polymerization of the first thermoplastic resin (S) is used for the polymerization reaction of such a second thermoplastic resin (A), a particularly significant effect of the cleaning step, described in detail below, can be observed.

[0029] (1) Structural units common to the first thermoplastic resin Examples of structural units that can be contained in the second thermoplastic resin (A) include structural units derived from the monomer compounds used in the production of the first thermoplastic resin (S), such as bisphenol structural units, fluorene structural units, etc. That is, the second thermoplastic resin can include fluorene structural units derived from the fluorene compound used as a monomer in the production of the first thermoplastic resin, bisphenol structural units derived from bisphenol compounds such as BPA, etc.

[0030] In the second thermoplastic resin, the proportion of bisphenol structural units is, for example, 10 to 90 mol%, preferably 20 to 80 mol% or 30 to 70 mol%, and more preferably 40 to 60 mol%. In addition, in the second thermoplastic resin, the proportion of fluorene structural units based on the number of moles of all structural units is, for example, 10 to 90 mol%, preferably 20 to 80 mol% or 30 to 70 mol%, and more preferably 40 to 60 mol%.

[0031] (2) Other Structural Units Structural Units Derived from Alicyclic Compounds In addition to the structural units described above, the second thermoplastic resin (A) may have the following structural units: For example, structural units derived from alicyclic monomers represented by the following formula (3): In the general formula (3), R is H, CH ３ or C ２ H ５The diol compound as the alicyclic monomer represented by formula (3) is, for example, a C ２ An isomer in which the OH group is attached to the 6-position (2,6-position isomer), C ２ It may be an isomer in which the OH group is bonded to the 7-position (2,7-position isomer), or a mixture of these isomers.

[0032] Structural units derived from specific dihydroxy compounds Other structural units that can be contained in the second thermoplastic resin (A) include those derived from the following monomer compounds. For example, the dihydroxy compounds exemplified below include hydroquinone, resorcinol, 4,4'-biphenol, 1,1-bis(4-hydroxyphenyl)ethane (bisphenol E), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, 4,4'-(p-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, 9,9- These structural units are derived from monomer compounds such as bis(4-hydroxy-3-methylphenyl)fluorene (biscresolfluorene), 9,9-bis(4-hydroxyphenyl)fluorene (bisphenolfluorene), tricyclodecane[5.2.1.0(2,6)]dimethanol (TCDDM), pentacyclopentadecanedimethanol, cyclohexane-1,4-dimethanol, decalin-2,6-dimethanol, decalin-1,5-dimethanol, norbornanedimethanol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,4,3,6-sorbide. Among the above-mentioned dihydroxy compounds, particularly preferred are 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), tricyclo(5.2.1.0 2.6 ) Decane dimethanol (TCDDM) is preferred.

[0033] The second thermoplastic resin containing the dihydroxy compound-derived structural unit is, for example, a polycarbonate resin. The glass transition temperature of the second thermoplastic resin containing the dihydroxy compound-derived structural unit is preferably 95°C or higher and 165°C or lower, more preferably 105°C or higher and 165°C or lower. A glass transition temperature lower than 95°C is undesirable because it reduces heat resistance and limits the usage environment. A glass transition temperature higher than 165°C is undesirable because it reduces fluidity and makes molding conditions more stringent. Furthermore, keeping the molecular weight low to ensure fluidity is undesirable because it becomes brittle. The total light transmittance of the second thermoplastic resin containing the dihydroxy compound-derived structural unit is preferably 87% or higher, more preferably 89% or higher. The YI value (yellowness index) of a 3 mm thick disk test specimen is preferably 3.0 or lower, more preferably 2.0 or lower. The second thermoplastic resin, such as a polycarbonate resin, which satisfies the above physical properties is particularly suitable as a molding material for optical applications such as optical films, optical disks, optical prisms, and optical lenses.

[0034] The polystyrene-equivalent weight average molecular weight of the second thermoplastic resin is preferably 20,000 to 200,000, and more preferably 35,000 to 100,000. If the polystyrene-equivalent weight average molecular weight is 20,000 or less, the impact resistance will be low, and if it is 200,000 or more, the flowability will be poor and molding conditions may become strict, which is not preferable.

[0035] Other Structural Units The second thermoplastic resin may contain at least one of the following structural units (I) to (V), and there are no particular limitations on how these structural units are contained in the resin. For example, in one embodiment, the second thermoplastic resin may be a homopolymer composed of each of the structural units (I) to (V), a copolymer (e.g., a binary resin, a ternary resin, etc.) composed of a plurality of the structural units (I) to (V), or a copolymer composed of at least one of the structural units (I) to (V) and another structural unit other than the structural units (I) to (V). Alternatively, the second thermoplastic resin may be a blend of these homopolymers, or a blend of a homopolymer and a copolymer. The second thermoplastic resin may have a random, block, or alternating copolymer structure.

[0036] Structural Unit (I) In some embodiments, the second thermoplastic resin includes a structural unit (I) derived from a monomer (diol compound) represented by the following general formula (i): The structural unit (I) may be included singly, or two or more types may be included in combination.

[0037] In formula (i), R ａ and R ｂ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy 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 cycloalkoxy 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 3 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 ｈ R ｈ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 3 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent. ａ and R ｂis preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 3 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.

[0038] In formula (i), X represents a single bond or an optionally substituted fluorene group, preferably a single bond or an optionally substituted fluorene group having a total of 12 to 20 carbon atoms.

[0039] In formula (i), A and B each independently represent 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.

[0040] In formula (i), m and n each independently represent an integer of 0 to 6, preferably an integer of 0 to 3, and more preferably 0 or 1.

[0041] In formula (i), a and b each independently represent an integer of 0 to 10, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0042] In the formula (i), the substituent "may have a substituent" is not particularly limited, and examples thereof include a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkoxy group having 5 to 10 carbon atoms, an alkyloxycarbonyl group having 2 to 10 carbon atoms, a cycloalkyloxycarbonyl group having 5 to 10 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, a cycloalkylcarbonyloxy group having 5 to 10 carbon atoms, an arylcarbonyloxy group having 7 to 15 carbon atoms, a hydroxyalkylcarbonyl group having 2 to 10 carbon atoms, a glycidyloxycarbonyl group, a hydroxy group, a carboxy group, a cyano group, and an amide group having 1 to 10 carbon atoms.

[0043] Specific examples of the structural unit (I) include structural units derived from 2,2'-bis(1-hydroxymethoxy)-1,1'-binaphthalene, 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (also referred to as "BNE"), 2,2'-bis(2-hydroxyethoxy)-6,6'-diphenyl-1,1'-binaphthalene (also referred to as "DP"), 9,9-bis[6-(2-hydroxyethoxy)naphthalen-2-yl]fluorene (also referred to as "BNEF"), 2,2'-bis(3-hydroxypropyloxy)-1,1'-binaphthalene, 2,2'-bis(4-hydroxybutoxy)-1,1'-binaphthalene, etc. In one embodiment, the structural unit (I) includes at least one structural unit derived from BNE, DP, and BNEF.

[0044] Structural Unit (II) In some embodiments, the second thermoplastic resin includes a structural unit (II) derived from a monomer (diol compound) represented by the following general formula (ii): The structural unit (II) may be included as a single type alone, or as a combination of two or more types.

[0045] In formula (ii), R ｃ and R ｄ are each independently selected from the group consisting of a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy 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 cycloalkoxy 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. 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 3 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.

[0046] In formula (ii), Y represents a single bond, a fluorene group which may have a substituent, or —CR ２１ R ２２ -, -S-, -S(=O)-, -(CH ２ ) ｒ -, -O-, -(CH ２ ) ｒ -(SiR ２３ R ２４ -O) ｓ -SiR ２３ R ２４ - (CH ２ ) ｒ - and -CR ２５ R ２６ -Ph-CR ２５ R ２６ Y is preferably a single bond or -CR ２１ R ２２ - is. R ２１ , R ２２ , R ２３ , R ２４ , R ２５ and R ２６ 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. Ph represents a phenyl group. r and s each independently represent an integer of 0 to 5,000.

[0047] In formula (ii), A and B each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent. A and B each independently represent 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.

[0048] In formula (ii), p and q each independently represent an integer of 0 to 4, preferably 0 or 1.

[0049] In formula (ii), a and b each independently represent an integer of 0 to 10, preferably an integer of 0 to 5, more preferably an integer of 0 to 2, for example, 0 or 1.

[0050] In formula (ii), the substituent when "may have a substituent" is not particularly limited, but examples thereof include a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkoxy group having 5 to 10 carbon atoms, an alkyloxycarbonyl group having 2 to 10 carbon atoms, a cycloalkyloxycarbonyl group having 5 to 10 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, a cycloalkylcarbonyloxy group having 5 to 10 carbon atoms, an arylcarbonyloxy group having 7 to 15 carbon atoms, a hydroxyalkylcarbonyl group having 2 to 10 carbon atoms, a glycidyloxycarbonyl group, a hydroxy group, a carboxy group, a cyano group, and an amide group having 1 to 10 carbon atoms.

[0051] Specific examples of the structural unit (II) include 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (also referred to as "BCFL"), 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (also referred to as "BPEF"), 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene (also referred to as "BPPEF" or "PG"), 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-methylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-methylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-tert-butylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-isopropylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-cyclohexylphenyl]fluorene, bisphenol A (also referred to as "BPA"), bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bis(4-hydroxyphenyl)-2,2-dichloroethylene, bisphenol E, bisphenol F, bisphenol G, bisphenol Bisphenol M (also referred to as "BPM"), bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol P-AP (4,4'-(1-phenylethylidene)bisphenol), bisphenol P-CDE (4,4'-cyclododecylidenebisphenol), bisphenol P-HTG (4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol), bisphenol P-MIBK (4,4'-(1,3-dimethylbutylidene)bisphenol), bisphenol PEO-FL (bisphenoxyethanol), ethanolfluorene), bisphenol P-3MZ (4-[1-(4-hydroxyphenyl)-3-methylcyclohexyl]phenol), bisphenol OC-FL (4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol), bisphenol Z, BP-2EO (2,2'-[1,1'-biphenyl]-4,4'-diylbis(oxy)bisethanol), S-BOC (4,4'-(1-methylethylidene)bis(2-methylphenol), TrisP-HAP (4,4',In one embodiment, the structural unit (B) includes at least one structural unit derived from BPEF, BPPEF, BPA, BPM, and BCFL.

[0052] Structural Unit (III) In some embodiments, the second thermoplastic resin includes a structural unit (III) derived from a monomer (diol compound) represented by the following general formula (iii): The structural unit (III) may be included as a single type alone, or as a combination of two or more types.

[0053] In formula (iii), R ｇ Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, and an isopropyl group. ｇ are each preferably independently a hydrogen atom.

[0054] Specific examples of the structural unit (III) include structural units derived from decahydro-1,4:5,8-dimethanonaphthalene diols (also referred to as "D-NDM"). Examples include those derived from (decahydro-1,4:5,8-dimethanonaphthalene-2,6-diyl)dimethanol, (decahydro-1,4:5,8-dimethanonaphthalene-2,7-diyl)dimethanol, (2-methyldecahydro-1,4:5,8-dimethanonaphthalene-2,6-diyl)dimethanol, (2-methyldecahydro-1,4:5,8-dimethanonaphthalene-2,7-diyl)dimethanol, (2-ethyldecahydro-1,4:5,8-dimethanonaphthalene-2,6-diyl)dimethanol, and (2-ethyldecahydro-1,4:5,8-dimethanonaphthalene-2,7-diyl)dimethanol. In one embodiment, building block (III) comprises at least one building block derived from D-NDM.

[0055] Structural Unit (IV) In some embodiments, the thermoplastic resin contains a structural unit (IV) derived from a monomer represented by the following general formula (iv): The structural unit (IV) may be contained alone, or two or more types may be contained in combination.

[0056]

[0057] In formula (iv), R ａ and R ｂ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy 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 cycloalkoxy 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 3 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 ｈ R ｈ represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 3 to 20 carbon atoms which contains one or more hetero ring atoms selected from O, N and S and which may have a substituent. ａ and R ｂ is preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 3 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.

[0058] In formula (iv), X represents a single bond or an optionally substituted fluorene group, preferably a single bond or an optionally substituted fluorene group having a total of 12 to 20 carbon atoms.

[0059] In formula (iv), A and B each independently represent 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.

[0060] In formula (iv), m and n each independently represent an integer of 0 to 6, preferably an integer of 0 to 3, and more preferably 0 or 1.

[0061] In formula (iv), a and b each independently represent an integer of 0 to 10, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0062] In formula (iv), R' and R'' are each independently selected from the group consisting of a hydroxy group, a halogen atom, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, and an aryloxy group having 6 to 20 carbon atoms which may have a substituent. R' and R'' are preferably a hydroxy group, a linear alkoxy group having 1 to 5 carbon atoms, or an aryloxy group having 6 to 10 carbon atoms, and more preferably a hydroxy group, a methoxy group, an ethoxy group, or a phenyloxy group.

[0063] In formula (iv), the substituent when "may have a substituent" is not particularly limited, and examples thereof include a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkoxy group having 5 to 10 carbon atoms, an alkyloxycarbonyl group having 2 to 10 carbon atoms, a cycloalkyloxycarbonyl group having 5 to 10 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, a cycloalkylcarbonyloxy group having 5 to 10 carbon atoms, an arylcarbonyloxy group having 7 to 15 carbon atoms, a hydroxyalkylcarbonyl group having 2 to 10 carbon atoms, a glycidyloxycarbonyl group, a hydroxy group, a carboxy group, a cyano group, and an amide group having 1 to 10 carbon atoms.

[0064] Specific examples of the structural unit (IV) include those derived from 2,2'-([1,1'-binaphthalene]-2,2'-diylbis(oxy))acetoacetic acid (BINOL-DC) and its methyl ester, ethyl ester, phenyl ester, etc. In one embodiment, the structural unit (IV) includes at least one structural unit derived from BINOL-DC and its methyl ester, ethyl ester, or phenyl ester.

[0065] Structural Unit (V) In some embodiments, the second thermoplastic resin includes a structural unit (V) derived from a monomer represented by the following general formula (v): The structural unit (V) may be included as a single type alone, or as a combination of two or more types.

[0066] In formula (v), G １ and G ２ Each of the groups independently represents an alkylene group having 1 to 8 carbon atoms, which may have a substituent. Examples of the alkylene group having 1 to 8 carbon atoms include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, tert-butylene, and pentylene. Among these, G １ and G ２ is preferably methylene, ethylene, propylene, butylene, isobutylene, or sec-butylene, more preferably methylene, ethylene, or propylene, even more preferably methylene or ethylene, and particularly preferably ethylene.

[0067] In formula (v), K １ and K. ２ each independently represents a hydroxy group, an alkoxy group, or a halogen atom. １ and K. ２ When is an alkoxy group, the number of carbon atoms therein is not particularly limited, and it is, for example, an alkoxy group having 1 to 20 carbon atoms.

[0068] In formula (v), R ｐ１ and R ｐ２each independently represents a halogen atom, a cyano group, or an alkyl group having 1 to 8 carbon atoms which may have a substituent. １ and Ar ２ Each of r independently represents a phenyl group or a naphthyl group which may have a substituent. １ and r ２ Each independently represents an integer of 0 to 2, preferably 0 to 1. In formula (v), r ３ and r ４ each independently represents an integer of 0 to 1.

[0069] In the formula (v), the substituent "may have a substituent" is not particularly limited, and examples thereof include a halogen atom, a hydroxy group, a carboxy group, a cyano group, etc. These substituents may be present alone or in combination of two or more.

[0070] Other Structural Units The second thermoplastic resin may further contain, in addition to the above-mentioned structural units, structural units of other polycarbonate resins, or may further contain structural units of other resins (polyester resins, polyester carbonate resins, polyolefin resins), etc.

[0071] For example, other structural units of polycarbonate resins include structural units derived from diol compounds such as 2,2'-[1,4-phenylenebis(methyleneoxy[1,1'-binaphthalene]-2',2-diyloxy)]di(ethan-1-ol) (DBHBNABHP) represented by the following formula; spiroglycol (3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, SPG); bisphenol TMC; bisphenol A; and alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, neopentyl glycol, and octylene glycol.

[0072] Further, examples of the structural units of polyester resins or polyester carbonate resins include structural units derived from dicarboxylic acids or ester derivatives thereof, such as terephthalic acid, naphthalenedicarboxylic acid, 9H-fluorene 9,9-dipropionic acid or its monoalkyl (methyl, ethyl, propyl, isopropyl, butyl) ester derivatives or dialkyl ester derivatives (for example, 9,9-di(2-methoxycarbonylethyl)fluorene, 9,9-di(2-carboxyethyl)fluorene), 2,2′-bis(carboxymethoxy)-1,1′-binaphthyl, 2,2′-bis(carboxyethoxy)-1,1′-binaphthyl, 2,2′-bis(carboxyphenoxy)-1,1′-binaphthyl, and compounds represented by the following formula: Furthermore, examples of structural units derived from dihydroxy compounds (diols) that constitute polyester resins or polyester carbonate resins include structural units derived from dihydroxy compounds (diols) such as 2,2'-[1,4-phenylenebis(methyleneoxy[1,1'-binaphthalene]-2',2-diyloxy)]di(ethan-1-ol) (DBHBNABHP); spiroglycol (3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, SPG); bisphenol TMC; bisphenol A; and alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, neopentyl glycol, and octylene glycol.

[0073] In some embodiments, the content of the other structural units described above is preferably as small as possible. For example, the content is preferably 50% by weight or less, more preferably 30% by weight or less, and even more preferably 10% by weight or less, based on the total weight of the thermovisible resin.

[0074] Examples of resins having the structural units (I) to (V) are described in, for example, International Publication WO 2014 / 073496, JP 2010-248445, JP 2008-111047, International Publication WO 2016 / 052370, International Publication WO 2018 / 016516, and PCT / JP2019 / 042232.

[0075] 2-3. Properties of Thermoplastic Resins Although the properties of the first thermoplastic resin (S) and the second thermoplastic resin (A) are not particularly limited, these thermoplastic resins have, for example, the following properties.

[0076] The weight-average molecular weight of the thermoplastic resin is, for example, 5,000 to 100,000, preferably 5,000 to 50,000, and more preferably 6,000 to 30,000. The weight-average molecular weight of the thermoplastic resin is further preferably 10,000 to 25,000, more preferably 12,000 to 22,000, and particularly preferably 15,000 to 20,000. In some embodiments of the thermoplastic resin, the weight-average molecular weight is preferably 12,000 to 40,000, more preferably 14,000 to 36,000, and particularly preferably 16,000 to 35,000.

[0077] The thermoplastic resin has a glass transition temperature (Tg) according to JIS K 7121 of, for example, 105 to 170°C, preferably 110 to 165°C, and more preferably 115 to 160°C. The Tg range of the thermoplastic resin is preferably 120 to 160°C, and more preferably 130 to 158°C.

[0078] The refractive index (nD) of the thermoplastic resin is preferably 1.670 to 1.720, more preferably 1.675 to 1.710, and even more preferably 1.680 to 1.705. Generally, since a high refractive index (nD) value is preferred for a thermoplastic resin that can be used for optical applications, the lower limit is important, and the thermoplastic resin in one embodiment of the present invention has a refractive index (nD) value of 1.650 or greater. The refractive index (nD) value of the thermoplastic resin is preferably 1.675 or greater, more preferably 1.680 or greater, and even more preferably 1.685 or greater. While the upper limit of the refractive index (nD) of the thermoplastic resin is not particularly important, the thermoplastic resin in one embodiment of the present invention has a refractive index (nD) value of 1.710 or less.

[0079] The Abbe number (νd) of the thermoplastic resin is preferably 16.0 to 24.0, more preferably 16.5 to 23.0, 17.0 to 22.0, or 17.5 to 21.0, even more preferably 18.0 to 20.0, and even more preferably 18.5 to 19.5. Thermoplastic resins, particularly those used for optical applications, preferably have a high refractive index. High refractive index thermoplastic resins usually tend to have small Abbe number (νd) values. However, optical thermoplastic resins with high Abbe number (νd) values ​​can also be useful. The thermoplastic resin in one embodiment of the present invention has an Abbe number (νd) of 17.0 or greater. The Abbe number (νd) of the thermoplastic resin is preferably 17.5 or greater, more preferably 18.0 or greater, and even more preferably 18.4 or greater.

[0080] <3. Method for producing second thermoplastic resin (A)> If polymerization equipment such as a reactor containing adhesive impurities derived from SPG is used in the next polymerization reaction as is, the molar ratio of the raw material monomers may not be properly reflected in the resulting polymer, and there is also a risk of clogging of piping, distillation equipment, etc. Therefore, in the present invention, the reactor used in the polymerization step for producing the first thermoplastic resin (S) containing structural units derived from SPG, etc., is subjected to a cleaning step (a) in which the inside of the reactor is cleaned, and then a polymerization reaction of another resin, for example, a polymerization reaction of the second thermoplastic resin (A), is carried out. Each step, such as the cleaning step (a), included in the method for producing the second thermoplastic resin (A) will be described below.

[0081] 3-1. First Removal Step After the first thermoplastic resin (S) is produced, it is preferable to remove the first thermoplastic resin (S) from the reactor (first removal step). Thereafter, a cleaning step (a) is carried out to clean the reactor as follows.

[0082] 3-2. Cleaning Step (a) The method for producing the second thermoplastic resin (A) includes a cleaning step of cleaning the reactor in which the polymerization reaction for producing the first thermoplastic resin (S) has been carried out. The cleaning step is carried out after the polymerization reaction for producing the first thermoplastic resin (S), preferably after the removal step. The objects to be cleaned in the cleaning step are mainly spiroglycol (SPG), SPG derivatives, oligomers derived from SPG or SPG derivatives, and the like remaining inside the reactor.

[0083] In the washing step, it is preferable to wash the reactor first with a carbonate ester and then with an aryl alcohol. Alternatively, washing with a carbonate ester and an aryl alcohol may be repeated alternately, or washing with an aryl alcohol may be followed by washing with a carbonate ester.

[0084] The type of carbonate ester used in the washing step is not particularly limited and is selected from a carbonate diester and a carbonate monoester. Examples of carbonate esters used in the washing step include diaryl carbonate esters, dialkyl carbonate esters, and monoaryl monoalkyl carbonate esters. Diaryl carbonate esters having a total of 6 to 24 carbon atoms, dialkyl carbonate esters having a total of 3 to 18 carbon atoms, and monoaryl monoalkyl carbonate esters having a total of 4 to 20 carbon atoms are preferably used. Furthermore, the carbonate ester used in the washing step is preferably a component used as a raw material in the polymerization reaction in the reactor after washing, or a by-product generated by the polymerization reaction.

[0085] The carbonate ester used in the washing step preferably has a relatively high boiling point, for example, a boiling point higher than that of the aryl alcohol used in the same washing step. The carbonate ester used has a boiling point at atmospheric pressure of, for example, 180°C or higher, preferably 200°C or higher, more preferably 220°C or higher, and even more preferably 250°C or higher. When a carbonate ester with a high boiling point is heated and used in the washing step, particularly when used as the first cleaning agent in the washing step, it may soften and dissolve resinous impurities inside a reactor or the like, making it possible to discharge them. A preferred example of the carbonate ester used in the washing step is diphenyl carbonate, which is used in the production of a polycarbonate resin as the second thermoplastic resin. The carbonate ester used in the washing step preferably has a GC purity of 95% or higher, more preferably 98% or higher, and even more preferably 99% or higher. Furthermore, the carbonate ester (a small amount of unreacted carbonate ester) contained in the distillate that may be produced in the prepolymerization step and the step of producing the thermoplastic resin (A), which will be described in detail below, may be purified and reused in the washing step.

[0086] The type of aryl alcohol used in the washing step is not particularly limited, and for example, a monocyclic or polycyclic aryl alcohol having a total carbon number of 6 to 20 is used. Specific examples of aryl alcohols used in the washing step include phenol, naphthol, and benzyl alcohol. In addition, the aryl alcohol used in the washing step is preferably a by-product produced by the polymerization reaction or a component used as a raw material in the polymerization reaction in the reactor after washing.

[0087] The aryl alcohol used in the washing step preferably has a relatively low boiling point, for example, a boiling point lower than that of the carbonate ester used in the same washing step. The aryl alcohol used has a boiling point at atmospheric pressure of, for example, 250°C or lower, preferably 220°C or lower, and more preferably 200°C or lower. When an aryl alcohol with a low boiling point is used in the washing step, particularly when used as a cleaning agent after the carbonate ester, it may be possible to reliably wash out and discharge partially dissolved solid components. A preferred example of the aryl alcohol used in the washing step is phenol, which is used when producing a polycarbonate resin as the second thermoplastic resin. The aryl alcohol used in the washing step preferably has a GC purity of 95% or higher, more preferably 98% or higher, and even more preferably 99% or higher. Furthermore, aryl alcohols such as phenol (a small amount of unreacted aryl alcohol) contained in the distillate produced in the prepolymerization step and the step of producing the thermoplastic resin (A), which will be described in detail below, may be purified and reused in the washing step.

[0088] In the washing step, a cleaning agent other than carbonate esters and aryl alcohols may be used. For example, a cleaning agent can be appropriately selected from components used as raw materials in the polymerization reaction in the reactor after washing, by-products generated by the polymerization reaction, etc. However, using SPG and SPG derivatives as cleaning agents in the washing step is not preferable because it may cause impurities to adhere to the surface of the reactor, etc. Note that as a cleaning agent used at the end of the washing step, i.e., immediately before proceeding to the next step such as the discharge step described below, a cleaning agent other than the monomer compound that serves as a raw material for the polymerization reaction is preferred, for example, aryl alcohol, etc. Use of carbonate esters, which can serve as raw materials for the polymerization reaction, as the final cleaning agent in the washing step may adversely affect the raw material molar ratio, potentially causing errors in the ratio of constituent units in the resulting resin. However, if only aryl alcohols such as phenol remain in the reaction vessel, they can be distilled off without affecting the raw material molar ratio in the polymerization reaction immediately thereafter.

[0089] The temperature inside the reactor in the washing step, i.e., the temperature of the washing agent such as a carbonate ester or an aryl alcohol, is, for example, 100 to 350°C, preferably 120 to 300°C or 150 to 320°C, more preferably 150 to 280°C or 160 to 290°C, and particularly preferably 180 to 275°C or 190 to 270°C.

[0090] The pressure inside the reactor in the washing step is not particularly limited, but is preferably higher than atmospheric pressure. The pressure inside the reactor in the washing step is adjusted within a range of, for example, 760 mmHg to 1000 mmHg, preferably 760 mmHg to 960 mmHg or 760 mmHg to 950 mmHg, more preferably 760 mmHg to 940 mmHg or 760 mmHg to 900 mmHg, and particularly preferably 760 mmHg to 880 mmHg or 760 mmHg to 860 mmHg.

[0091] The temperature inside the reactor in the cleaning step is preferably below the boiling point of the cleaning agent, such as a carbonate ester or an aryl alcohol. It is also preferable to maintain the temperature of the cleaning agent within a range that does not cause reflux. That is, in the cleaning step, cleaning agents, such as a carbonate ester or an aryl alcohol, are preferably used as liquids for cleaning. For example, when diphenyl alcohol, which has a boiling point of 270°C at atmospheric pressure, is used under atmospheric pressure, the temperature inside the reactor is preferably adjusted to within a range of 240 to 260°C, or when phenol, which has a boiling point of 190°C at atmospheric pressure, is used under atmospheric pressure, the temperature inside the reactor is preferably adjusted to within a range of 160 to 185°C. Although the preferred temperature range varies depending on the type of cleaning agent, the pressure inside the reactor, and the like, the temperature inside the reactor is preferably adjusted to a temperature, for example, 1 to 50°C lower, preferably 3 to 30°C lower, and more preferably 5 to 15°C lower than the reflux temperature of the cleaning agent at that pressure.

[0092] The total time for the cleaning step, i.e., the total time for which the cleaning agent is in contact with the inner surface of the reactor, is not particularly limited and may be, for example, 20 minutes to 20 hours, 40 minutes to 12 hours, 1 hour to 10 hours, 2 hours to 8 hours, or 3 hours to 6 hours. When a carbonate ester is used as the cleaning agent, the cleaning time may be within the above-mentioned time period or may be half of the above-mentioned time period, i.e., 10 minutes to 10 hours, 20 minutes to 6 hours, 30 minutes to 5 hours, 1 hour to 4 hours, or 1 hour and a half to 3 hours. When an aryl alcohol is used as the cleaning agent, the cleaning time may be, like the carbonate ester, 20 minutes to 20 hours, 40 minutes to 12 hours, 1 hour to 10 hours, 2 hours to 8 hours, or 3 hours to 6 hours, or may be half of these time periods.

[0093] The washing step is preferably carried out under an inert gas atmosphere, for example, nitrogen gas, etc. In the washing step, it is preferable to stir the washing agent in the reactor.

[0094] 3-3. Discharge Step After the cleaning step is completed, it is preferable to discharge the cleaning agent from the reactor to the outside (discharge step). In the discharge step, it is preferable to discharge all of the cleaning agents, such as carbonate ester and aryl alcohol, used in the cleaning step (a) from the reactor. However, for example, if the cleaning agent, such as carbonate ester or aryl alcohol, preferably the aryl alcohol used at the end of the cleaning step, is a raw material or by-product of the polymerization reaction (such as the prepolymerization step described below or the polymerization reaction for polymerizing the second thermoplastic resin (A)) immediately after the discharge step, it may not be necessary to completely remove the cleaning agent from the reactor.

[0095] 3-4. Preliminary Polymerization Step (b) In order to further ensure the effects of the above-mentioned cleaning step, it is preferable to carry out a preliminary polymerization step (b). In the preliminary polymerization step (b), a preliminary polymerization reaction is carried out in the reactor after cleaning. By carrying out such a preliminary polymerization reaction, even if the reactor is incorporated into a large polymerization apparatus, it is possible to more reliably remove impurities without undergoing steps such as disassembling and assembling the apparatus. The distillate produced by the preliminary polymerization reaction reliably cleans, for example, the distillation apparatus (distillation pipe and cooling tower), piping, etc.

[0096] In the prepolymerization step, for example, bisphenol A is used as a monomer and reacted with a carbonate ester or the like to polymerize a polycarbonate resin (B) containing structural units derived from bisphenol A. In this way, preparatory production of a thermoplastic resin by a simple method using only easily available monomers makes it possible to reliably remove impurities derived from SPG. In the prepolymerization step, in addition to bisphenol A, the above-mentioned monomer compounds that produce structural units contained in the first thermoplastic resin (S) or the second thermoplastic resin (A) may also be polymerized.

[0097] As a method for producing the thermoplastic resin in the prepolymerization step, a known method is used, and for example, the above-mentioned method for producing the first thermoplastic resin (S) can be applied.

[0098] 3-5. Second Removal Step After the preliminary resin is produced in the prepolymerization step, it is preferable to remove the preliminary resin from the reactor (second removal step). Thereafter, steps including the following may be performed. However, since there is a possibility that the prepolymerized resin may remain in the reactor after the preliminary resin is removed in the second removal step, it is preferable to repeat washing with, for example, diphenyl carbonate (DPC), phenol, or the like (washing step (a)). That is, it is preferable to repeat the washing step (a) and the prepolymerization step (b) and produce the thermoplastic resin (A) after the final washing step (a). Furthermore, the washing agent in the final washing step (a) preferably contains only components corresponding to by-products in the polymerization reaction, for example, only an aryl alcohol such as phenol. Then, after the final washing step (a), it is preferable to produce the thermoplastic resin (A) in the main polymerization step (d) described below.

[0099] 3-6. Analysis step (c) It is preferable to analyze the content of SPG, SPG derivatives, or the total amount thereof contained in the distillate distilled in the polymerization reaction in the prepolymerization step (analysis step (c)). The components of the distillate vary depending on the raw materials of the polymerization reaction in the prepolymerization step, but are, for example, phenol. In the analysis step (c), the content of impurities such as SPG contained in the distillate is measured, for example, by the measurement method described below.

[0100] A predetermined target value may be set for the content of the above-mentioned impurities such as SPG contained in the distillate, and the prepolymerization step (b), or the washing step (a) and the prepolymerization step (b) may be repeated until a distillate containing impurities in a content equal to or less than the target value is produced.

[0101] The target value for the content of SPG-derived impurities contained in the distillate is not particularly limited, but may be, for example, 2000 ppm by mass or less, less than 2000 ppm by mass, 1000 ppm by mass or less, less than 1000 ppm by mass, 500 ppm by mass or less, less than 500 ppm by mass, 200 ppm by mass or less, less than 200 ppm by mass, 100 ppm by mass or less, or less than 100 ppm by mass.

[0102] 3-7. Main Polymerization Step (d) In the main polymerization step (d), the second thermoplastic resin (A) is produced using a reactor that has been cleaned at least through the cleaning step (a) described above. Known polymerization reaction conditions for producing the second thermoplastic resin (A) can be used; for example, the polymerization reaction conditions for the first thermoplastic resin (S) described above can be applied. Thus, according to the production method of this embodiment, a reactor that may be contaminated by SPG, which has a relatively high vapor pressure, is cleaned through a specified process, and the polymerization reaction for producing the target thermoplastic resin is carried out. This prevents components such as unreacted SPG, its derivatives, and their oligomers from remaining as impurities inside the reactor or equipment connected to the reactor.

[0103] It is preferable to use a batch reactor for each step of the method for producing the second thermoplastic resin (A), because in a continuous reactor, components such as resin and impurities from the immediately preceding polymerization reaction tend to remain in the reactor, whereas in a batch reaction, the effects of the above-mentioned washing step (a) and the like can be more easily maximized.

[0104] 3-8. Repeated Implementation of Production Steps One or more of the steps included in the second thermoplastic resin production method described above may be repeated. For example, the cleaning step (a), the prepolymerization step (b), and the analysis step (c) may be repeated, or the cleaning step (a) and the analysis step (c) may be repeated, or only the cleaning step (a) may be repeated. By appropriately repeating the production steps, it may be possible to more reliably remove impurities, mainly derived from SPG, from within a polymerization apparatus such as a reactor. For example, the cleaning step (a), the prepolymerization step (b), and the analysis step (c) may be repeated, or steps (b) and (c) may be repeated until the content of the SPG-derived impurities in the distillate measured in the analysis step (c) becomes equal to or less than a predetermined target value.

[0105] 3-9 Polymerization Apparatus A polymerization apparatus that can be used in the present invention will now be described with reference to specific examples. Figure 1 is a diagram that schematically illustrates a part of a polymerization reactor.

[0106] In steps for carrying out polymerization reactions such as the above-mentioned preliminary polymerization step (b) and main polymerization step (d), for example, the following polymerization apparatus can be used. A polymerization reactor 10, a portion of which is illustrated in FIG. 1 , includes a reactor 20 in which the polymerization reaction takes place, as well as a cooling device (condenser) 30, a distillate reservoir 40, and the like. The reactor 20 is provided with a resin raw material inlet 20A and a resin outlet 20B. When the polymerization apparatus 10 is operated to produce a resin, raw material monomers are supplied to the reactor 20 through the resin raw material inlet 20A. In the reactor 20, the polymerization reaction takes place, preferably while stirring the reaction system with an agitator blade 22. The resin produced in the reactor 20 is discharged from the reactor 20 through the resin outlet 20B.

[0107] By-products produced in the polymerization reaction in the reactor 20, such as phenol produced as a by-product in the polymerization reaction for producing a polycarbonate resin, are sent from the reactor 20 to the cooling device 30 via a connecting pipe 24. In the cooling device 30, the by-products sent from the reactor 20 are cooled and liquefied to form a distillate.

[0108] Of the distillate produced in the cooling device 30, components that can be reused in the polymerization reaction in the reactor 20 are sent from the cooling device 30 via the first distillate outlet 30A and then sent to the reactor 20. For example, a component that can be reused as a cleaning agent used in the reactor 20 is sent from the cooling device 30 via the first distillate outlet 30A, preferably after a purification process, and then sent to the reactor 20. Similarly, components that can be reused in the polymerization reaction in the reactor 20 are also sent from the cooling device 30 via the first distillate outlet 30A, preferably after a purification process, and then sent to the reactor 20. Meanwhile, a portion of the distillate is sent from the second distillate outlet 30B through the inlet 40A of the distillate reservoir 40 into the distillate reservoir 40. In the distillate reservoir 40, a portion of the distillate is extracted via the outlet 40B as needed, and its components are analyzed. The analysis results of the distillate are used for managing the polymerization reaction in the reactor 20, etc. As described above, the polymerization reactor 10 preferably includes a distillation device such as the connecting pipe 24 and the distillate reservoir 40, and a cooling device 30. In the examples described in detail below, the content of spiroglycol in phenol, which is a sample of the distillate stored in the distillate reservoir 40, was measured.

[0109] (Polymerization of Resin Having SPG Structural Units (Thermoplastic Resin (S))) As raw materials, 6.47 mol of SPG (spiroglycol: 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane) represented by the structural formula above, 9.92 mol of Bis-TMC (1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane) represented by the structural formula above, 13.7 mol of BPEF (9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene) represented by the structural formula above, 32.6 mol of DPC (diphenyl carbonate), and 3×10 sodium bicarbonate were used. －４mol was placed in a 50 L reactor equipped with a stirrer and distillation device and heated to 180°C under a nitrogen atmosphere of 760 mmHg. Dissolution of the raw materials was confirmed 60 minutes after the start of heating, and stirring was continued for an additional 110 minutes under the same conditions. The vacuum was then adjusted to 200 mmHg, and the temperature was raised to 200°C at a rate of 60°C / hr. At this time, the start of distillation of by-product phenol was confirmed. The reaction was then continued at 200°C for 20 minutes. The temperature was then raised to 230°C at a rate of 75°C / hr, and 10 minutes after the temperature increase, the temperature was maintained at that level while the vacuum was reduced to 1 mmHg over 1 hour. The temperature was then raised to 245°C at a rate of 60°C / hr, and stirring was continued for an additional 30 minutes. After the reaction was completed, nitrogen was introduced into the reactor to return to normal pressure, and the resulting polycarbonate resin was removed while pelletizing. Furthermore, by-product phenol was analyzed by GC-MS, and it was confirmed that the by-product phenol contained 1,180 ppm by mass of SPG.

[0110] (DPC / Phenol Washing) To wash the inside of the reactor, 3 kg of DPC (diphenyl carbonate) was placed in the reactor, and the temperature was set to 270°C under a nitrogen atmosphere of 760 mmHg and raised. After confirming the dissolution of the DPC, stirring was carried out for 120 minutes, and the reactor pressure rose to 856 mmHg. The temperature was then lowered, and the DPC was extracted from the reactor. Note that no reflux was performed during the period from heating and pressurizing the DPC in the reactor until it was extracted from the reactor. Next, 3 kg of phenol for washing was placed in the reactor, and the temperature was set to 190°C under a nitrogen atmosphere of 760 mmHg and raised. Stirring was carried out for 120 minutes, and the reactor pressure rose to 938 mmHg. The temperature was then lowered, and the phenol was extracted from the reactor. In this case, no reflux was performed from the time the phenol was added to the reactor until it was extracted.

[0111] (First BPA-PC Polymerization (Preliminary Polymerization)) Next, as raw materials, 47.0 mol of BPA (4,4'-(propane-2,2-diyl)diphenol), 50.3 mol of DPC (diphenyl carbonate), and 4.7 x 10 mol of sodium hydrogen carbonate were used. －４mol was placed in a 50 L reactor equipped with a stirrer and distillation device and heated to 180°C under a nitrogen atmosphere of 760 mmHg. Dissolution of the raw materials was confirmed 60 minutes after the start of heating, and stirring was continued for an additional 110 minutes under the same conditions. The vacuum was then adjusted to 200 mmHg, and the temperature was raised to 200°C at a rate of 60°C / hr. At this time, the start of distillation of by-product phenol was confirmed. The reaction was then continued at 200°C for 20 minutes. The temperature was then raised to 230°C at a rate of 75°C / hr, and 10 minutes after the temperature increase, the temperature was maintained at that level while the vacuum was reduced to 1 mmHg over 1 hour. The temperature was then raised to 245°C at a rate of 60°C / hr, and stirring was continued for an additional 30 minutes. After the reaction was completed, nitrogen was introduced into the reactor to return to normal pressure, and the resulting polycarbonate resin was removed while pelletizing. Furthermore, by-product phenol was analyzed by GC-MS, and it was confirmed that the by-product phenol contained 156 ppm by mass of SPG.

[0112] (Second BPA-PC Polymerization (Prepolymerization)) After DPC / phenol washing was again carried out by the same method as described in the above section (DPC / phenol washing), BPA-PC polymerization was carried out by the above section (BPA-PC polymerization), and the polymerized BPA-PC was removed from the reactor. Thereafter, DPC / phenol washing was further carried out by the method described in the above section (DPC / phenol washing). Analysis of the by-product phenol by GC-MS confirmed that SPG was not detected in the by-product phenol (less than about 60 ppm by weight, which is the detection limit).

[0113] (Polymerization of Resin (Thermoplastic Resin (A)) After Washing) Using the reactor that had been subjected to the above-described washing and prepolymerization, a second thermoplastic resin (A) was polymerized as follows. As raw materials, 34.2 mol of BPEF (9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene) represented by the above structural formula, 36.8 mol of DPC (diphenyl carbonate), and 3×10 mol of sodium hydrogen carbonate were used. －４mol was placed in a 50 L reactor equipped with a stirrer and distillation device and heated to 180°C under a nitrogen atmosphere of 760 mmHg. Dissolution of the raw materials was confirmed 60 minutes after the start of heating, and stirring was continued for an additional 110 minutes under the same conditions. The vacuum was then adjusted to 200 mmHg, and the temperature was raised to 200°C at a rate of 60°C / hr. At this time, the start of distillation of by-product phenol was confirmed. The reaction was then continued at 200°C for 20 minutes. The temperature was then raised to 230°C at a rate of 75°C / hr, and 10 minutes after the temperature increase, the temperature was maintained at that level while the vacuum was reduced to 1 mmHg over 1 hour. The temperature was then raised to 245°C at a rate of 60°C / hr, and stirring was continued for an additional 30 minutes. After the reaction was completed, nitrogen was introduced into the reactor to return to normal pressure, and the resulting polycarbonate resin was removed while pelletizing.

[0114] The SPG concentrations in the phenol by-products produced in each of the above polymerization steps are summarized in Table 1 below. The molecular structure of the monomer compound used in the above polymerization reaction is as follows:

[0115] <Measurement of SPG Amount in Phenol> As described above, 0.025 g of by-product phenol obtained during polymerization was dissolved in 20 g of tetrahydrofuran (THF) to prepare a sample solution. A calibration curve for SPG was prepared, and the sample solution was quantified by GC-MS under the following measurement conditions. The detection limit for the amount of SPG contained in phenol was approximately 60 ppm by weight. GC-MS Measurement Conditions: Measurement Device (GC Part): Agilent Technologies 7890A GC System Column: Agilent Technologies HP-5 Method: 50-320°C - Hold at 50°C for 5 minutes, then increase temperature at 10°C / min Injection to 300°C Split Ratio: 10:1 Measurement Device (MS Part): Agilent Technologies 5977B MSD

[0116] As is clear from the results of the Examples, impurities derived from SPG were present in the reactor immediately after the production of a thermoplastic resin using SPG as a monomer, but it was confirmed that the impurities were removed after the washing and prepolymerization steps. Therefore, by producing a second thermoplastic resin using polymerization equipment such as a reactor that has undergone these steps, the effects of impurities can be prevented, the target ratio of constituent units can be reliably achieved, and the condition of parts that are prone to clogging, such as a distillation device and piping, can be maintained in good condition. That is, according to this embodiment, it is possible to reliably dissolve and wash impurities and unnecessary resin components remaining in the reactor (reaction tank), piping connecting the reactor to other equipment, valves, liquid delivery devices, etc. by supplying one or more cleaning solutions selected from, for example, monohydroxy compounds of the same type as the by-products and carbonate diesters used as raw materials in the polymerization reaction.

[0117] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0118] 10 Polymerization reactor 20 Reactor 24 Connecting pipe 30 Cooling device 40 Distillate reservoir

Claims

1. A method for producing a second thermoplastic resin (A) after polymerizing a first thermoplastic resin (S) containing a structural unit derived from spiroglycol (SPG) or an SPG derivative, the method comprising: a cleaning step (a); in the cleaning step (a), a reactor used in the production of the first thermoplastic resin (S) is cleaned with a carbonate ester and then with an aryl alcohol.

2. The method for producing a thermoplastic resin according to claim 1, further comprising a step of removing the first thermoplastic resin (S) from the reactor before carrying out the washing step (a).

3. The method for producing a thermoplastic resin according to claim 1, wherein in the washing step (a), the carbonate ester and the aryl alcohol are used under conditions below their respective boiling points.

4. The method for producing a thermoplastic resin according to claim 1, wherein in the washing step (a), at least one of spiroglycol (SPG), SPG derivatives, and oligomers derived from SPG or SPG derivatives remaining in the reactor is washed.

5. The method for producing a thermoplastic resin according to claim 1, further comprising a prepolymerization step (b), in which a polycarbonate resin (B) containing structural units derived from bisphenol A is polymerized in the reactor.

6. The method for producing a thermoplastic resin according to claim 5, further comprising an analysis step (c), in which the content of spiroglycol or SPG derivative in the distillate distilled in the polymerization reaction in the prepolymerization step (b) is analyzed.

7. The method for producing a thermoplastic resin according to claim 1, further comprising a main polymerization step (d) of polymerizing the second thermoplastic resin (A), and a discharge step (e) prior to the main polymerization step (d), wherein the carbonate ester and aryl alcohol used in the washing step (a) are discharged from the reactor in the discharge step (e).

8. The method for producing a thermoplastic resin according to claim 6, wherein steps (a) to (c) are repeated.

9. The method for producing a thermoplastic resin according to claim 8, wherein steps (a) to (c) are repeated until the content of spiro glycol or SPG derivative in the distillate measured in the analysis step (c) falls to a predetermined target value or less.

10. The method for producing a thermoplastic resin according to claim 1, wherein the reactor is equipped with a distillation and cooling system.

11. The method for producing a thermoplastic resin according to claim 1, wherein the SPG derivative is represented by the following formula (I): (In formula (I), R １ and R ２ are each independently selected from aliphatic alkyl groups having 1 to 10 carbon atoms and alicyclic alkyl groups having 4 to 12 carbon atoms, both of which have a hydroxyl group and may be substituted with other substituents.

12. The method for producing a thermoplastic resin according to claim 1, wherein the first thermoplastic resin is a polycarbonate resin (S).

13. The production method according to claim 12, wherein the polycarbonate resin (S) further contains a structural unit derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (Bis-TMC) and / or a structural unit derived from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF).

14. The manufacturing method according to claim 1, wherein the second thermoplastic resin (A) is any one of polyester, polycarbonate, and polyester / polycarbonate copolymer.

Images