Method for producing thermoplastic resin

Abstract

The present invention provides a method for producing a thermoplastic resin containing a structural unit derived from 9, 9-bis (4-(2-hydroxyethoxy) phenyl) fluorene (BPEF) represented by the following structural formula, in which the structural unit derived from 9, 9-bis (4-(2-hydroxyethoxy) phenyl) fluorene (BPEF) is introduced into the thermoplastic resin. The BPEF is used as a raw material in which the content of sulfate ions (SO42-) in the BPEF is 0.8 ppm or less, the content of sodium ions (Na +) in the BPEF is 10 ppm or less, and the content of calcium ions (Ca < 2 + >) in the BPEF is 0.01 ppm or more. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a method for producing a thermoplastic resin containing a structural unit derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (hereinafter sometimes referred to as "BPEF"). Background Art

[0002] BPEF, which is a resin raw material, can be produced by various production methods, for example, as shown in Patent Documents 1 and 2. However, BPEF cannot be industrially mass-produced in a stable and high-quality manner, and its reactivity may vary unexpectedly depending on the batch or manufacturer.

[0003] The cause of such fluctuations is still unclear, and development of a new production method capable of controlling the reactivity of a thermoplastic resin using BPEF as a raw material is desired.

[0004] In addition to impurities derived from the raw materials, various impurities may be mixed into BPEF during the manufacturing process or in the circulation process after manufacturing. For example, Patent Documents 3 and 4 disclose the amount of S and the amount of Na. Patent Document 5 discloses the sulfur content. In addition, Patent Document 6 discloses that the amount of sulfur from -SO in BPEF is reduced to -1.5. 3 H group and -SO 3 By setting the sulfur content of the R group to a certain concentration or less, the hue can be improved.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 7-165657

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2007-23016

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2007-197368

[0010] Patent Document 4: Japanese Patent Application Laid-Open No. 2011-074048

[0011] Patent Document 5: Japanese Patent Application Laid-Open No. 2018-168124

[0012] Patent Document 6: Japanese Patent Application Laid-Open No. 2008-111047 Summary of the invention

[0013] Problems to be solved by the invention

[0014] An object of the present invention is to provide a new production method capable of controlling the reactivity of a thermoplastic resin using BPEF as a raw material.

[0015] Technical solutions to solve problems

[0016] In order to solve the above problems, the inventors of the present invention have repeatedly conducted in-depth research and found that the impurities contained in BPEF contain substances that have polymerization catalytic properties or depolymerization catalytic properties of thermoplastic resins. Specifically, not only a specific amount of sulfate ions (SO 4 2－ ), sodium ion (Na + ) will affect such polymerization catalytic performance or depolymerization catalytic performance. A specific amount of calcium ions (Ca 2+ ) also have an impact, and it was found that in order to stably control the reactivity of the thermoplastic resin, it is very important to use a BPEF containing a specific amount of these ionic species, thereby completing the present invention.

[0017] That is, the present invention is as follows.

[0018] <1> A method for producing a thermoplastic resin comprising a structural unit derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF) represented by the following structural formula:

[0019] Using the sulfate ions (SO 4 2－ ) is less than 0.8 ppm, the sodium ions (Na + ) is less than 10 ppm, and the calcium ions (Ca 2+ ) is 0.01ppm or more of the above-mentioned BPEF as a raw material.

[0020]

[0021] <2> The method according to <1> above, wherein the sulfate ions (SO 4 2－ ) is 0.01 to 0.8 ppm, the sodium ions (Na + ) is 0.01 to 10 ppm, and the calcium ions (Ca 2 + ) is 0.01 to 0.5 ppm of the above-mentioned BPEF as a raw material.

[0022] <3> The production method according to <1> or <2>, wherein the sulfate ions (SO 4 2－ ) is 0.01 to 0.15 ppm, the sodium ions (Na +) is 0.01 to 0.10 ppm, and the calcium ion (Ca 2+ ) is 0.01 to 0.20 ppm of the above-mentioned BPEF as a raw material.

[0023] <4> The production method according to any one of <1> to <3>, wherein before the BPEF is used to polymerize the thermoplastic resin, the sulfate ion (SO 4 2－ ), sodium ion (Na + ) and calcium ions (Ca 2 + ) concentration.

[0024] <5> The production method according to any one of <1> to <4> above, wherein a polymerization catalyst is replenished during the polymerization of the thermoplastic resin.

[0025] <6> The production method according to <5> above, wherein the polymerization catalyst is an alkali metal compound.

[0026] <7> The production method according to any one of <1> to <6>, wherein the thermoplastic resin further has at least one structural unit selected from the group consisting of the following general formulas (1) to (4).

[0027]

[0028] [Wherein,

[0029] X a , X b , X c , X d , X e and X f each independently represents an alkylene group having 1 to 4 carbon atoms,

[0030] R a , R b , R c , R cc , R d , R dd , R e , R ee , R f and R ff each independently selected from a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more heteroatoms selected from O, N and S, an aryloxy group having 6 to 20 carbon atoms, and -C≡C-R i ,

[0031] R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms containing one or more heteroatoms selected from O, N and S,

[0032] a, b, c, d, e and f each independently represent an integer of 0 to 10,

[0033] h, i, j, j', k, k', m, m', n and n' each independently represent an integer of 0 to 4, R g Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.]

[0034] <8> The production method according to any one of <1> to <7>, wherein the thermoplastic resin is a polycarbonate resin.

[0035] Effects of the Invention

[0036] According to the present invention, a new production method capable of controlling the reactivity of a thermoplastic resin using BPEF as a raw material can be provided. DETAILED DESCRIPTION

[0037] Hereinafter, the present invention will be described in detail with reference to the embodiments and examples, but the present invention is not limited to the embodiments and examples shown below, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

[0038] One embodiment of the present invention is a method for producing a thermoplastic resin containing a structural unit derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF) represented by the following structural formula, characterized in that sulfate ions (SO 4 2－ ) is less than 0.8 ppm, the sodium ions (Na + ) is less than 10 ppm, and the calcium ions (Ca 2+ ) is 0.01ppm or more of the above BPEF as a raw material. If the sulfate ion (SO 4 2－ ) exceeds 0.8ppm, the reactivity will deteriorate. On the other hand, if the calcium ions (Ca 2+ ) is lower than 0.01ppm, the reactivity will deteriorate.

[0039]

[0040] The BPEF used as a raw material in the present invention preferably contains sulfate ions (SO 4 2－)0.01~0.8ppm, containing sodium ions (Na + )0.01~10ppm, and contains calcium ions (Ca 2+ )0.01~0.5ppm.

[0041] The BPEF used as a raw material in the present invention preferably contains sulfate ions (SO 4 2－ )0.01~0.15ppm, containing sodium ions (Na + )0.01~0.10ppm, and contains calcium ions (Ca 2+ )0.01~0.20ppm.

[0042] In a preferred embodiment of the present invention, it is preferred to measure the sulfate ions (SO 4 2－ ), sodium ion (Na + ) and calcium ions (Ca 2+ ) concentration. Among them, the sulfate ions (SO 4 2－ ), sodium ion (Na + ) and calcium ions (Ca 2+ ) can be measured by the method described in the examples below.

[0043] In a preferred embodiment of the present invention, it is preferred to supplement the polymerization catalyst during the polymerization process of the thermoplastic resin. As described in paragraph 0025 below, the amount of catalyst added at the beginning of the reaction is preferably 10:1 relative to 1 mol of the total dihydroxy compound as the raw material. －9 ~10 －4 The molar ratio is preferably 10 －7 ~10 －5 On the other hand, the amount of catalyst to be added is preferably 10 to 1 mol relative to the total amount of the dihydroxy compound as the raw material. －10 ~10 －4 The molar ratio is preferably 10 －8 ~10 －5 The catalyst is used in a molar ratio or preferably supplemented in an amount of 0.01 to 3 times, more preferably 0.1 to 2 times, particularly preferably 0.3 to 1 times the amount of the catalyst initially added for the reaction.

[0044] As the polymerization catalyst to be added, an alkali metal compound is preferred, and specifically, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, 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 phenylborate, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenyl phosphate, disodium salt, dipotassium salt, dicesium salt, dilithium salt of bisphenol A, sodium salt, potassium salt, cesium salt, lithium salt, etc. As the polymerization catalyst to be added, the same type as the polymerization catalyst added at the beginning of the reaction is preferred, and sodium hydrogen carbonate is particularly preferred.

[0045] In another preferred embodiment of the present invention, the thermoplastic resin preferably further has at least one structural unit selected from the group consisting of the following general formulae (1) to (4).

[0046]

[0047] In the formula,

[0048] X a , X b , X c , X d , X e and X f each independently represents an alkylene group having 1 to 4 carbon atoms,

[0049] R a , R b , R c , R cc , R d , R dd , R e , R ee , R f and R ff each independently selected from a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more heteroatoms selected from O, N and S, an aryloxy group having 6 to 20 carbon atoms, and -C≡C-R i ,

[0050] R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms containing one or more heteroatoms selected from O, N and S,

[0051] a, b, c, d, e and f each independently represent an integer of 0 to 10,

[0052] h, i, j, j', k, k', m, m', n and n' each independently represent an integer of 0 to 4, R g Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0053] In a preferred embodiment of the present invention, the thermoplastic resin is preferably a polycarbonate resin or a polyester carbonate resin. The case where the thermoplastic resin of the present invention is a polycarbonate resin will be described in detail below.

[0054] The glass transition temperature of the polycarbonate resin in the present invention is preferably 95°C to 165°C, more preferably 105°C to 165°C. When the glass transition temperature is lower than 95°C, the heat resistance deteriorates and the use environment is limited, which is not preferred. When the glass transition temperature is higher than 165°C, the fluidity deteriorates and the molding conditions become harsh, which is not preferred. In addition, it becomes brittle when the molecular weight is suppressed to ensure fluidity, which is not preferred. The total light transmittance is preferably 87% or more, more preferably 89% or more. In addition, the YI value (yellowness) of a 3 mm thick disc test piece is preferably 3.0 or less, more preferably 2.0 or less.

[0055] The polycarbonate resin satisfying the above-mentioned physical properties is particularly suitable as a molding material for optical applications such as optical films, optical disks, optical prisms, and optical lenses.

[0056] The polystyrene-equivalent weight average molecular weight of the polycarbonate resin in the present invention is preferably 20,000 to 200,000, more preferably 35,000 to 100,000. When the polystyrene-equivalent weight average molecular weight is less than 20,000, impact resistance decreases, while when it exceeds 200,000, fluidity deteriorates and molding conditions become severe, which is not preferred.

[0057] The method for producing the polycarbonate resin of the present invention is described below. It is preferable to use a known melt polycondensation method in which diols and carbonic acid diesters are reacted in the presence of a basic compound catalyst, an ester exchange catalyst, or a mixed catalyst consisting of both.

[0058] As the carbonic acid diester used in the present invention, diphenyl carbonate, ditolyl carbonate, dichlorophenyl carbonate, meta-cresol carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. can be used. Among these, diphenyl carbonate is particularly preferred. In addition, the chlorine content in the diphenyl carbonate that also becomes the cause of coloration is preferably 20ppm or less, more preferably 10ppm or less. Relative to 1 mol of the dihydroxy compound as a raw material, the amount of diphenyl carbonate is preferably 0.97 to 1.2 mol, and particularly preferably 0.99 to 1.10 mol.

[0059] In the production method of the present invention, known basic compounds and transesterification catalysts are used as polymerization catalysts. Examples of such compounds include alkali metals and / or alkaline earth compounds, nitrogen-containing compounds, and metal compounds such as tin.

[0060] Organic acids, inorganic salts, oxides, hydroxides, hydrides or alkoxides of alkali metals and alkaline earth compounds, quaternary ammonium bases and salts thereof, amines and the like are preferably used, and these compounds may be used alone or in combination.

[0061] As the alkali metal compound, specifically, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, 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 phenylborate, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenyl phosphate, disodium salt, dipotassium salt, dicesium salt, dilithium salt of bisphenol A, sodium salt, potassium salt, cesium salt, lithium salt of phenol, etc. Sodium hydrogen carbonate is particularly preferably used.

[0062] In addition, as the alkaline earth metal compound, specifically, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenylphosphate, etc. can be used.

[0063] In addition, as nitrogen-containing compounds, specifically, ammonium hydroxides having alkyl groups, aryl groups, alkylaryl groups, 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 and 2-phenylimidazole; or alkaline salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate, etc.

[0064] As the alkali metal compound, an alkali metal salt of an acid complex of an element of Group 14 of the Periodic Table or an alkali metal salt of an oxyacid of an element of Group 14 of the Periodic Table can be used. The elements of Group 14 of the Periodic Table are silicon, germanium, and tin.

[0065] Specifically, examples of alkali metal salts of acid radical complexes of elements of Group 14 of the periodic table include NaGe(OMe) 5 、NaGe(OEt) 3 Germanium compounds; NaSn(OMe) 3 、NaSn(Ome) 2In addition, examples of alkali metal salts of oxygen-containing acids of elements of Group 14 of the periodic table include monosodium orthosilicate, disodium monostannate, and monosodium germanate.

[0066] These polymerization catalysts are preferably used in an amount of 10 to 10 mole of the dihydroxy compound as a raw material. －9 ~10 －4 The amount of moles is preferably 10 －7 ~10 －5 Molar amounts were used.

[0067] The melt polycondensation method of the present invention uses the above-mentioned raw materials and polymerization catalyst, and performs melt polycondensation under heating and normal or reduced pressure while removing by-products through transesterification reaction. The reaction is usually carried out in a multi-stage process of two or more stages.

[0068] Specifically, the first stage reaction is carried out at a temperature of 120 to 220°C, preferably 160 to 200°C, and a pressure of normal pressure to 200 Torr for 0.1 to 5 hours, preferably 0.5 to 3 hours. Then, the temperature is slowly raised to a final temperature of 230 to 260°C over 1 to 3 hours, and the pressure is slowly reduced to a final pressure of less than 1 Torr, and the reaction is continued. Finally, a polycondensation reaction is carried out at a temperature of 230 to 260°C under a reduced pressure of less than 1 Torr, and the reaction is terminated by restoring the pressure with nitrogen when a predetermined viscosity is reached. The reaction time below 1 Torr is 0.1 to 2 hours, and the overall reaction time is 1 to 6 hours, usually 2 to 5 hours.

[0069] Such reaction can be carried out in a continuous manner or in an intermittent manner. The reaction apparatus used when carrying out the above reaction can be a vertical reaction apparatus equipped with an anchor stirring paddle, a MAXBLEND stirring paddle, a spiral ribbon stirring paddle, etc., can also be a horizontal reaction apparatus equipped with a paddle stirring paddle, a grid stirring paddle, a glasses-type stirring paddle, etc., can also be an extruder type reaction apparatus equipped with a screw, and, preferably, these reaction apparatuses are appropriately combined to use considering the viscosity of the above polymer.

[0070] After the polymerization reaction of the polycarbonate resin involved in the present invention is completed, in order to maintain thermal stability and hydrolytic stability, the catalyst is preferably removed or inactivated. It is generally preferred to implement a method of adding a known acidic substance to deactivate the polymerization catalyst. As such a substance, it is specifically preferred to use aromatic sulfonic acids such as p-toluenesulfonic acid; aromatic sulfonic acid esters such as butyl p-toluenesulfonate and hexyl p-toluenesulfonate; aromatic sulfonic acid salts such as tetrabutylphosphonium dodecylbenzenesulfonate; organic halides such as stearyl chloride, benzoyl chloride, and p-toluenesulfonyl chloride; alkyl sulfuric acid such as dimethylsulfuric acid; organic halides such as benzyl chloride, etc.

[0071] These deactivators are preferably used in an amount of 0.01 to 50 times the total amount of the added catalyst, more preferably 0.3 to 20 times the total amount of the added catalyst. Alternatively, if the deactivator is melt-kneaded, the thermal history of the resin increases, which may cause partial modification of the resin, and sometimes the deactivator is not particularly added.

[0072] After the catalyst is deactivated, a step of devolatilizing to remove low-boiling compounds in the polymer may be provided at a pressure of 0.1 to 1 mmHg and a temperature of 200 to 350° C. For this purpose, it is preferred to use a horizontal device equipped with a stirring blade having excellent surface renewal performance, such as a paddle-type stirring blade, a grid stirring blade, or a spectacled stirring blade, or a thin film evaporator.

[0073] In the present invention, in addition to the above-mentioned heat stabilizers and hydrolysis stabilizers, antioxidants, pigments, dyes, reinforcing agents or fillers, ultraviolet absorbers, lubricants, release agents, crystal nucleating agents, plasticizers, fluidity improvers, antistatic agents, antibacterial agents, etc. are preferably added.

[0074] The addition of these additives can utilize the existing known methods to mix the components into the polycarbonate resin. Preferably, these additives are directly mixed in the molten resin after the polymerization is completed in a vertical or horizontal tank reactor or extruder, and the method of pelletizing is carried out after cooling. In addition, it is also possible to appropriately select a method in which the molten resin after the polymerization is temporarily cooled and pelletized, and then the components are dispersed and mixed using a high-speed mixer represented by a drum mixer or a Henschel mixer, a ribbon blender, or a super mixer, and then melt-kneading is carried out using an extruder, a Banbury mixer, a roller, etc.

[0075] Example

[0076] Hereinafter, although the Example and the comparative example of this invention are shown and the content of this invention is demonstrated in detail, this invention is not limited to these Examples.

[0077] 1) BPEF

[0078] As BPEF, commercially available BPEF was used.

[0079] 2) Sulfate ions (SO 4 2－ )concentration

[0080] After removing the matrix using a concentration column, the sulfate ion (SO 4 2－ ) concentration (ppm). The analysis conditions are recorded below.

[0081] Device: Integrated ion chromatograph 930 manufactured by Wan Tong

[0082] Detector: Conductivity detector

[0083] Sample preparation: BPEF was dissolved in a mixed solution of 40 v / v% ultrapure water and 60 v / v% acetone to prepare a sample.

[0084] Eluent: A mixed solution of 3.6 mM sodium carbonate and 5 v / v% acetone was used.

[0085] 3) Sodium ions (Na) in BPEF + ) concentration and calcium ion (Ca 2+ )concentration

[0086] After BPEF was ashed, it was analyzed by ICP emission spectrometry to calculate the sodium ions (Na + ) concentration and calcium ion (Ca 2+ ) concentration (ppm). The analysis conditions are recorded below.

[0087] Ashing conditions: BPEF was heated at 800° C. for 6 hours and adjusted with dilute hydrochloric acid.

[0088] Apparatus: iCAP 6300Duo manufactured by Thermo Fisher Scientific

[0089] 4) Reactivity <Reactivity Test 1>

[0090] In a flask with a cooling tube, 95.2 g (0.215 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF) as a sample, 48.0 g (0.224 mol) of diphenyl carbonate (DPC) and 1.44 × 10 －4 g(1.72×10 －6 mol, that is, 8 μmol of a 0.1 mass % aqueous solution was added to 1 mol of BPEF).

[0091] The mixture was heated to 200° C. at a pressure of 760 Torr in a nitrogen atmosphere, stirred for 1 hour, and then reduced in pressure to 170 Torr to produce a thermoplastic resin. Thereafter, it was visually observed whether phenol as a by-product was distilled off within 5 minutes.

[0092] The distillation of phenol was observed:

[0093] No distillation of phenol was observed: ×

[0094] <Reactivity test 2>

[0095] In addition to using sodium bicarbonate 2.17 × 10 －4 g(2.58×10 －6The observation was carried out in the same manner as in the reactivity test 1 except that 12 μmol, that is, 0.1 mass % aqueous solution was added to 1 mol of BPEF.

[0096] The distillation of phenol was observed:

[0097] No distillation of phenol was observed: ×

[0098] 5) Depolymerization

[0099] In a flask equipped with a stirrer capable of detecting stirring torque, a cooling tube, and a thermometer, 43.85 g (0.10 mol) of BPEF as a sample, 218.50 g (1.02 mol) of DPC, and 1.44 × 10 －4 g(1.72×10 － 6 mol, that is, 8 μmol of a 0.1 mass % aqueous solution was added to 1 mol of BPEF).

[0100] In a nitrogen atmosphere, the mixture was heated to 200°C at a pressure of 760 Torr, stirred for 1 hour, and then reduced to 170 Torr while increasing the temperature to 240°C at a rate of 60°C / hr. After maintaining the reduced pressure of 170 Torr for 10 minutes, the reduced pressure was reduced to less than 1 Torr over 1 hour to produce a thermoplastic resin. After reaching less than 1 Torr, the reaction was continued for 30 minutes, and the polymerization state, i.e., the change in the stirring torque, was observed.

[0101] When the speed of the stirrer is constant, if the polymerization continues to progress, the viscosity of the resin increases, resulting in an increase in the stirring torque and the stirring becomes impossible, and the stirring speed needs to be reduced. On the other hand, in the case of depolymerization, even if the stirring torque increases as described above, the stirring becomes impossible and the stirring speed is reduced, the stirring will not become impossible even if the stirring speed is increased again. Therefore, the judgment is as follows.

[0102] If the stirring torque continues to increase or does not change: No depolymerization

[0103] When the stirring torque decreases naturally during polymerization: depolymerization occurs (Example 1)

[0104] Use sulfate ions (SO 4 2－ ) is 0.11ppm, sodium ion (Na + ) is 0.02ppm, and calcium ions (Ca 2+ ) was 0.11 ppm of BPEF (BPEF-1) to produce a thermoplastic resin, and the reactivity and the presence or absence of depolymerization were determined. The results showed that the reactivity test 1 was "0", the reactivity test 2 was "0", and the depolymerization was "no".

[0105] (Examples 2 to 6, Comparative Examples 1 to 3)

[0106] A thermoplastic resin was produced in the same manner as in Example 1 except that BPEF was replaced with the substances shown in Table 1, and the reactivity test 1, the reactivity test 2 and the presence or absence of depolymerization were evaluated.

[0107] [Table 1]

[0108]

[0109] (Example 7)

[0110] In a flask equipped with a stirrer capable of detecting stirring torque, a cooling tube and a thermometer, 95.2 g (0.215 mol) of BPEF-5 used in Example 5, 48.0 g (0.224 mol) of diphenyl carbonate (DPC) and 1.44 × 10 －4 g(1.72×10 －6 mol, that is, 8 μmol of a 0.1 mass % aqueous solution was added to 1 mol of BPEF).

[0111] In a nitrogen atmosphere, the mixture was heated to 200°C at a pressure of 760 Torr, stirred for 1 hour, and then decompressed to 170 Torr. No phenol was observed to distill out at this time. Nitrogen was introduced to return the decompression to normal pressure, and 0.73×10 sodium bicarbonate was added. －4 g(0.86×10 －6 mol, i.e., 4 μmol, 0.1 mass % aqueous solution is added to 1 mol of BPEF). Next, the pressure was reduced to 170 torr, and the temperature was raised to 240°C at a rate of 60°C / hr. The pressure reduction of 170 torr was maintained for 10 minutes, and phenol was observed to distill. After that, the pressure was reduced to below 1 torr in 1 hour. After reaching below 1 torr, stirring was continued for 30 minutes. At this time, there was no decrease in stirring torque. Nitrogen was introduced, and the polycarbonate resin was able to be taken out of the flask. Productivity was improved by supplementing sodium bicarbonate as a polymerization catalyst.

Claims

1. A method for producing a thermoplastic resin, the thermoplastic resin comprising a structural unit derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF) represented by the following structural formula, the method comprising: Using the sulfate ions (SO 4 2－ ) is less than 0.8 ppm, the sodium ions (Na + ) is less than 10 ppm and the calcium ions (Ca 2+ ) is 0.01ppm or more of the BPEF as a raw material, 2. The manufacturing method according to claim 1, It is characterized in that Using the sulfate ions (SO 4 2－ ) is 0.01 to 0.8 ppm, the sodium ions (Na + ) is 0.01 to 10 ppm, and the calcium ions (Ca 2+ ) is 0.01 to 0.5 ppm of the BPEF as a raw material.

3. The manufacturing method according to claim 1 or 2, It is characterized in that Using the sulfate ions (SO 4 2－ ) is 0.01 to 0.15 ppm, the sodium ions (Na + ) is 0.01 to 0.10 ppm, and the calcium ions (Ca 2+ ) is 0.01 to 0.20 ppm of the BPEF as a raw material.

4. The production method according to any one of claims 1 to 3, It is characterized in that Before using the BPEF to polymerize the thermoplastic resin, the sulfate ions (SO 4 2－ ), sodium ion (Na + ) and calcium ions (Ca 2+ ) concentration.

5. The production method according to any one of claims 1 to 4, It is characterized in that A polymerization catalyst is supplemented during the polymerization of the thermoplastic resin.

6. The manufacturing method according to claim 5, It is characterized in that The polymerization catalyst is an alkali metal compound.

7. The production method according to any one of claims 1 to 6, It is characterized in that The thermoplastic resin further has at least one structural unit selected from the following general formulae (1) to (4): In the formula, X a , X b , X c , X d , X e and X f each independently represents an alkylene group having 1 to 4 carbon atoms, R a , R b , R c , R cc , R d , R dd , R e , R ee , R f and R ff each independently selected from a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more heteroatoms selected from O, N and S, an aryloxy group having 6 to 20 carbon atoms, and -C≡C-R i , R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms containing one or more heteroatoms selected from O, N and S, a, b, c, d, e and f each independently represent an integer of 0 to 10, h, i, j, j', k, k', m, m', n and n' each independently represent an integer of 0 to 4, R g Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

8. The production method according to any one of claims 1 to 7, It is characterized in that The thermoplastic resin is a polycarbonate resin.

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