Method for manufacturing thermoplastic resin molding, and thermoplastic resin film

Abstract

To provide a manufacturing method capable of stably manufacturing a thermoplastic resin molding containing less foreign matters even at a start initial stage of manufacture.SOLUTION: A method for manufacturing a thermoplastic resin molding is a method for extruding a thermoplastic resin from an extruder and continuously manufacturing an extrusion molding, characterized in that a reduced viscosity after 4 hours or more from the start of molding manufacture is reduced by 2.0% or more relative to the reduced viscosity at the start of molding manufacture.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for producing a thermoplastic resin molded article and a thermoplastic resin film.

[0002] Thermoplastic resins are widely used in industrial products such as injection molded products, extrusion molded products, and films. In recent years, as the range of uses for thermoplastic resins has diversified, there has been a demand for improved productivity and cost reductions in addition to further improvements in performance and quality to meet user demands. For example, in the case of optical films used as display components, there is a demand for reduced impurities in the resin due to the trend toward higher resolution in smartphones and AR glasses, and for TVs, there is a demand for cost reductions due to the increasing size of displays. For example, Patent Document 1 describes that by interrupting the production of extrusion molded products for 5 minutes or more at least once within at least 4 hours to 48 hours after the start of production of the extrusion molded products, and changing the discharge pressure at the extruder outlet by 20% or more during the interruption of the production of the extrusion molded products, it is possible to efficiently and stably produce polycarbonate resin extrusion molded products that have excellent thermal stability, color, and mechanical strength and contain little foreign matter, without running out of gas due to decomposition gases. Patent Document 2 describes that in the production of a polycarbonate resin containing a specific structural unit, by adding a specific amount of a phosphorus-based compound having a specific partial structure to the resin under appropriate conditions, it is possible to stably obtain a polycarbonate resin that has a small amount of residual low-molecular-weight components, is less likely to discolor under moist heat, and has excellent hue and optical properties. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-180856 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-183087 Summary of the Invention [Problem to be solved by the invention]

[0004] While mass production of thermoplastic resins has traditionally been conducted in continuous plants, in recent years, there has been an increasing need to produce a wide variety of products in small quantities using the same equipment in order to meet diverse industrial demands. However, continuous plants are not inherently suited to the production of a wide variety of products in small quantities, which involves switching between different thermoplastic resins. For example, if the type of resin used before and after switching is significantly different, production must be stopped, and the remaining resin and degraded materials must be cleaned and then restarted. However, the inventors' research has revealed that there is a large amount of foreign matter in the resin during the initial production period after switching. Conventionally, various methods for reducing foreign matter by adjusting manufacturing conditions have been investigated (for example, Patent Documents 1 and 2), but there is no specific description of a method for reducing foreign matter in the early stages of manufacturing.

[0005] The present invention has been made in light of the above-mentioned background, and has as its object to provide a manufacturing method that can stably produce thermoplastic resin molded products with little foreign matter even in the early stages of production. [Means for solving the problem]

[0006] As a result of extensive research in light of the above problems, the present inventors discovered that in the production of thermoplastic resin molded bodies, by reducing the reduced viscosity of the thermoplastic resin by 2.0% or more after 4 hours from the start of production of the molded body relative to the reduced viscosity of the thermoplastic resin at the start of production of the molded body, it is possible to stably produce thermoplastic resin molded bodies with little foreign matter even in the early stages of production, and thus arrived at the present invention.

[0007] That is, the present invention has the following aspects. [1] A method for continuously producing extrusion molded thermoplastic resin products by extruding a thermoplastic resin from an extruder, characterized in that the reduced viscosity is reduced by 2.0% or more after 4 hours from the start of production of the molded products compared to the reduced viscosity at the start of production of the molded products.

[0008] [2] The method for producing a thermoplastic resin molded article according to [1], wherein the thermoplastic resin contains a structural unit represented by the following formula (1):

[0009] [ka]

[0010] [3] The method for producing a thermoplastic resin molded article according to [1] or [2], wherein the thermoplastic resin molded article is a polycarbonate resin. [4] The method for producing a thermoplastic resin molded article according to any one of [1] to [3], wherein the thermoplastic resin further contains a structural unit derived from at least one compound selected from the group consisting of an aliphatic dihydroxy compound, an alicyclic dihydroxy compound, a dihydroxy compound having a heterocyclic structure, an oxyalkylene glycol, an aromatic dihydroxy compound, and a diester compound.

[0011] [5] The method for producing a thermoplastic resin molded article according to any one of [1] to [4], wherein the thermoplastic resin contains at least one structural unit represented by the following formulas (2) to (4):

[0012] [ka]

[0013] [ka]

[0014] [ka]

[0015] [6] The method for producing a thermoplastic resin molded article according to any one of [1] to [5], wherein the thermoplastic resin further contains structural units represented by the following formula (5) and / or the following formula (6):

[0016] [ka]

[0017] (However, in the above formula (5), R 1 ~R 3 each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R 4 ~R 9 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring.)

[0018] [ka]

[0019] (However, in the above formula (6), R 1 ~R 3 each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R 4 ~R 9each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring.)

[0020] [7] A thermoplastic resin containing a structural unit represented by the following formula (1), 2 A thermoplastic resin film having no more than 75 foreign particles of 25 μm or larger per film.

[0021] [ka] [Effects of the Invention]

[0022] According to the present invention, it is possible to stably produce a thermoplastic resin molded article containing little foreign matter even in the early stages of production. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a process diagram showing a raw material preparation process in a polymerization facility in the production method of the present invention. [Figure 2] FIG. 1 is a process diagram showing a polymerization step and a distillation step in a polymerization facility in the production method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be described in detail below, but the present invention is not limited to the following description and can be practiced in any modified form without departing from the gist of the present invention.

[0025] In this specification, when "~" is used to express a numerical value or a physical property value, the values ​​before and after the "~" are included.

[0026] As used herein, the term "repeating structural unit" refers to a structural unit in which the same structure appears repeatedly in a resin and which is linked to form the resin. For example, in the case of a polycarbonate resin, the term "repeating structural unit" also refers to a carbonyl group. Furthermore, the term "structural unit" refers to a partial structure that constitutes a resin, specifically a specific partial structure contained in a repeating structural unit. For example, it refers to a partial structure sandwiched between adjacent linking groups in a resin, or a partial structure sandwiched between a polymerizable reactive group present at the terminal portion of a polymer and a linking group adjacent to the polymerizable reactive group. More specifically, in the case of a polycarbonate resin, a carbonyl group is the linking group, and a partial structure sandwiched between adjacent carbonyl groups is referred to as a structural unit. In addition, in this specification, the weight ratio of each structural unit in a polycarbonate resin is calculated assuming that the total weight of all structural units and linking groups is 100% by weight.

[0027] In this specification, the term "polycarbonate resin" is a concept that includes not only polycarbonate resins but also polyester carbonate resins, which are polymers whose structural units are linked not only by carbonate bonds but also by ester bonds.

[0028] The term "extrusion molded article" as used herein refers to any product obtained by molding a resin extruded from an extruder and then cooling and solidifying it, and includes various molded articles depending on the intended use, such as pellets, filaments, films, sheets, blow molded articles, etc.

[0029] [Thermoplastic resin] The thermoplastic resin in the present invention refers to a resin having a glass transition temperature or a melting point, and specific examples thereof include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, acrylic resin, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester, polyethylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyether ether ketone, thermoplastic polyimide, polyamideimide, etc. As the thermoplastic resin in the method for producing a thermoplastic resin molded article of the present invention, from the viewpoint of adaptability of the production method, polycarbonate resin, polyester resin, and polyamide resin are preferred, polycarbonate resin and polyester resin are more preferred, and polycarbonate resin is even more preferred.

[0030] The thermoplastic resin of the present invention preferably contains a structural unit represented by the following formula (1) (hereinafter, sometimes referred to as "structural unit (1)").

[0031] [ka]

[0032] Dihydroxy compounds forming the structural unit (1) include isosorbide, isomannide, and isoidet, which are stereoisomers. Of these dihydroxy compounds, isosorbide, which is abundant and easily available as a resource and is obtained by dehydration condensation of sorbitol produced from various starches, is most preferred in terms of availability, ease of production, and moldability. These dihydroxy compounds may be used alone or in combination of two or more.

[0033] In the resin used in the present invention, the structural unit (1) is preferably contained in an amount of 5% by mass or more and 80% by mass or less. The upper limit is more preferably 70% by mass or less, particularly preferably 60% by mass or less, and most preferably 50% by mass or less. The lower limit is more preferably 10% by mass or more, particularly preferably 15% by mass or more. When the content of the structural unit (1) is within the above range, a resin having more excellent mechanical properties, heat resistance, and optical properties can be obtained.

[0034] The thermoplastic resin preferably further contains a structural unit (hereinafter sometimes referred to as "structural unit (2)") derived from at least one compound selected from the group consisting of an aliphatic dihydroxy compound, an alicyclic dihydroxy compound, a dihydroxy compound having a heterocyclic structure, an oxyalkylene glycol, an aromatic dihydroxy compound, and a diester compound. The structural unit (2) is obtained by using at least one compound selected from the group consisting of an aliphatic dihydroxy compound, an alicyclic dihydroxy compound, a dihydroxy compound having a heterocyclic structure, an oxyalkylene glycol, an aromatic dihydroxy compound, and a diester compound as a raw material monomer for the thermoplastic resin.

[0035] Examples of aliphatic dihydroxy compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, and 1,6-hexanediol. Examples include straight-chain aliphatic dihydroxy compounds such as 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol, and branched-chain aliphatic dihydroxy compounds such as neopentyl glycol, 2-ethyl-1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, hydrogenated dilinoleyl glycol, and hydrogenated dioleyl glycol. Among these, linear aliphatic dihydroxy compounds such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol are preferred from the viewpoints of ease of availability and ease of handling.

[0036] Examples of alicyclic dihydroxy compounds include the following dihydroxy compounds: dihydroxy compounds which are primary alcohols of alicyclic hydrocarbons, exemplified by 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclopentadecanedimethanol, 2,6-decalindimethanol, 1,5-decalindimethanol, 2,3-decalindimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantanedimethanol, and dihydroxy compounds derived from terpene compounds such as limonene; and dihydroxy compounds which are secondary or tertiary alcohols of alicyclic hydrocarbons, exemplified by 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

[0037] Examples of dihydroxy compounds having a heterocyclic structure include spiroglycol and dioxane glycol.

[0038] Examples of oxyalkylene glycols that can be used include diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0039] Examples of aromatic-containing dihydroxy compounds include the following dihydroxy compounds: 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-diethylphenyl)propane, 2,2-bis(4-hydroxy-(3-phenyl)phenyl)propane, 2,2-bis(4-hydroxy-(3,5-diphenyl)phenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, bis(4-hydroxyphenyl)propane, )methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)decane, bis(4-hydroxy-3-nitrophenyl)methane, 3,3-bis(4-hydroxyphenyl)pentane, 1,3- ...diphenylmethane, 1,1-bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4- Bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)sulfone, 2,4'-dihydroxydiphenyl sulfone, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-3-methylphenyl)sulfide, bis(4-hydroxyphenyl)disulfide, 4, Aromatic bisphenol compounds such as 4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether; dihydroxy compounds having an ether group bonded to an aromatic group such as 2,2-bis(4-(2-hydroxyethoxy)phenyl)propane, 2,2-bis(4-(2-hydroxypropoxy)phenyl)propane, 1,3-bis(2-hydroxyethoxy)benzene, 4,4'-bis(2-hydroxyethoxy)biphenyl, and bis(4-(2-hydroxyethoxy)phenyl)sulfone;9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene Dihydroxy compounds having a fluorene ring, such as 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-butyl-6-methylphenyl)fluorene, and 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene;

[0040] Examples of diester compounds include the following dicarboxylic acids: aromatic dicarboxylic acids such as terephthalic acid, phthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-benzophenonedicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; and aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. These dicarboxylic acid components can be used as raw materials for polyester carbonate resins as dicarboxylic acids themselves, but depending on the production method, dicarboxylic acid esters such as methyl esters and phenyl esters, or dicarboxylic acid derivatives such as dicarboxylic acid halides can also be used as raw materials.

[0041] When the structural unit (2) is introduced into the thermoplastic resin of the present invention, it is preferably used for the purpose of adjusting heat resistance, melt processability, optical properties, mechanical properties, compatibility with other resins, etc. Among the structural units (2), from the viewpoint of adjusting the optical properties, mechanical properties, etc., particularly the properties required for optical film applications, structural units derived from aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, and dihydroxy compounds having a heterocyclic structure are preferred. Among these, structural units derived from alicyclic dihydroxy compounds and dihydroxy compounds having a heterocyclic structure are more preferred, and 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, and spiro glycol are even more preferred, with structural units derived from tricyclodecane dimethanol and spiro glycol being most preferred.

[0042] That is, the thermoplastic resin of the present invention preferably contains at least one structural unit represented by the following formulas (2) to (4), and more preferably contains a structural unit represented by the following formula (3) or (4).

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] The thermoplastic resin may contain a structural unit composed of a structural unit represented by the following formula (5) and / or a structural unit represented by the following formula (6). Hereinafter, such a structural unit may be referred to as an "oligofluorene structural unit."

[0047] [ka]

[0048] In the above formula (5), R 1 ~R 3 each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R 4 ~R 9 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring.

[0049] [ka]

[0050] In the above formula (6), R 1 ~R 3 each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R 4 ~R 9 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring.

[0051] The structural units represented by the formulas (5) and (6) not only have excellent physical properties such as heat resistance and photoelastic coefficient, but also, by strictly controlling the content ratio, can highly efficiently exhibit so-called reverse wavelength dispersion, in which the retardation decreases as the wavelength becomes shorter, and among the applications of optical films, particularly when used as a quarter-wave plate, it is possible to obtain near-ideal retardation characteristics over a wider wavelength range. Furthermore, since the structural unit derived from the compound represented by the formula (6) has negative birefringence, by combining it with a structural unit derived from a dihydroxy compound having positive birefringence, it is also possible to obtain a polymer with intrinsic birefringence close to zero.

[0052] The content of the structural units represented by the formulas (5) and (6) depends on the desired physical properties, but is preferably 1% by weight or more and 70% by weight or less. When reverse wavelength dispersion is desired, the content is preferably 5% by weight or more and 50% by weight or less, and more preferably 10% by weight or more and 30% by weight or less.

[0053] The compound represented by the formula (5) is a compound represented by the formula (5) and the formula (6), 1 ~R 2 is particularly preferably an alkylene group having 2 carbon atoms. 3 is particularly preferably an alkylene group having one carbon atom. 4 ~R 9 A hydrogen atom is particularly preferred. By selecting an appropriate structure for each substituent, a structural unit having excellent physical properties such as optical properties, heat resistance, and thermal stability can be obtained.

[0054] [Thermoplastic resin manufacturing conditions] When a polycarbonate resin is used in the present invention, it can be produced by a commonly used polymerization method. For example, it can be produced by a solution polymerization method or an interfacial polymerization method using phosgene or a carboxylic acid halide, or a melt polymerization method in which a reaction is carried out without using a solvent. Among these production methods, the melt polymerization method is preferred because it does not use a solvent or a highly toxic compound, thereby reducing the environmental load and also providing excellent productivity.

[0055] If a solvent is used in polymerization, the solvent may remain in the polycarbonate resin, and the plasticizing effect of the solvent lowers the glass transition temperature of the polycarbonate resin, which can cause quality fluctuations during processing steps such as molding and stretching, as described below. Furthermore, halogenated organic solvents such as methylene chloride are often used as solvents, but if halogenated solvents remain in the polycarbonate resin, they can cause corrosion of metal parts when molded articles made from this resin are incorporated into electronic devices, etc. Polycarbonate resins obtained by melt polymerization do not contain solvents, which is advantageous for stabilizing processing steps and product quality.

[0056] When producing polycarbonate resin by melt polymerization, a monomer having the structural units described above, a diester compound such as a carbonic acid diester, and a polymerization catalyst are mixed together, and a transesterification reaction (also called a polycondensation reaction) is carried out in the melt, and the reaction rate is increased while removing elimination components from the system. Toward the end of the polymerization, the reaction is continued under high temperature and high vacuum conditions until the desired molecular weight is achieved. Once the reaction is complete, the molten polycarbonate resin is withdrawn from the reactor. In this way, polycarbonate resin is obtained.

[0057] In the polycondensation reaction, the reaction rate and the molecular weight of the resulting polycarbonate resin can be controlled by strictly adjusting the molar ratio of all dihydroxy compounds to all diester compounds used in the reaction. In the case of polycarbonate resin, the molar ratio of carbonate diester to all dihydroxy compounds is preferably adjusted to 0.90 to 1.10, more preferably 0.96 to 1.08, and particularly preferably 0.98 to 1.06. In the case of polyestercarbonate resin, the molar ratio of the total amount of carbonate diester and all diester compounds to all dihydroxy compounds is preferably adjusted to 0.90 to 1.10, more preferably 0.96 to 1.08, and particularly preferably 0.98 to 1.06.

[0058] If the molar ratio deviates significantly from the upper or lower limit, it becomes impossible to produce a resin with the desired molecular weight. Furthermore, if the molar ratio is too low, the number of hydroxyl terminal groups in the produced resin increases, which may result in a deterioration in the thermal stability of the resin. Furthermore, a large amount of unreacted dihydroxy compound remains in the polycarbonate resin, which may cause contamination of the molding machine in the subsequent molding process or a poor appearance of the molded product. On the other hand, if the molar ratio is too high, the rate of the transesterification reaction may decrease under the same conditions, or the amount of residual carbonate diester or diester compound in the produced polycarbonate resin may increase, and these remaining low-molecular-weight components may similarly cause problems in the molding process.

[0059] The melt polymerization method is usually carried out in two or more multi-stage processes. The polycondensation reaction may be carried out in two or more stages using one polymerization reactor with conditions sequentially changed, or in two or more stages using two or more reactors with conditions changed for each stage. From the viewpoint of production efficiency, however, it is carried out using two or more, preferably three or more, reactors. The polycondensation reaction may be carried out in a batch system, a continuous system, or a combination of a batch system and a continuous system, but from the viewpoint of production efficiency and stability of quality, a continuous system is preferred.

[0060] In polycondensation reactions, it is important to properly control the balance between temperature and pressure in the reaction system. If either the temperature or pressure is changed too quickly, unreacted monomers may be distilled out of the reaction system. As a result, the molar ratio of dihydroxy compounds to diester compounds may change, and a polycarbonate resin with the desired molecular weight may not be obtained. Furthermore, the polymerization rate of the polycondensation reaction is controlled by the balance between the hydroxyl group terminals and the ester group terminals or carbonate group terminals. Therefore, particularly when polymerization is carried out in a continuous system, if the balance of the terminal groups fluctuates due to the distillation of unreacted monomers, it becomes difficult to control the polymerization rate at a constant rate, and there is a risk of significant fluctuation in the molecular weight of the resulting polycarbonate resin. Since the molecular weight of a polycarbonate resin correlates with its melt viscosity, there is a risk that when the resulting polycarbonate resin is molded, the melt viscosity will fluctuate, leading to problems such as the inability to obtain molded products of uniform dimensions.

[0061] Furthermore, if unreacted monomers are distilled out, not only the balance of the terminal groups but also the copolymerization composition of the polycarbonate resin may deviate from the desired composition, which may affect the mechanical properties and optical properties. In a retardation film, the wavelength dispersion of the retardation is controlled by the ratio of the fluorene-based monomer to other copolymerization components in the polycarbonate resin, so if the ratio is disrupted during polymerization, the designed optical properties may not be obtained.

[0062] Hereinafter, the melt polycondensation reaction process will be described by dividing it into a stage in which a monomer is consumed to produce an oligomer, and a stage in which polymerization is allowed to proceed up to a desired molecular weight to produce a polymer. Specifically, the following conditions can be adopted as reaction conditions for the first-stage reaction. That is, the internal temperature of the polymerization reactor is set within a range of usually 130°C or higher, preferably 150°C or higher, more preferably 170°C or higher, and usually 250°C or lower, preferably 240°C or lower, more preferably 230°C or lower. The pressure of the polymerization reactor is set within a range of usually 70 kPa or lower (hereinafter, pressure refers to absolute pressure), preferably 50 kPa or lower, more preferably 30 kPa or lower, and usually 1 kPa or higher, preferably 3 kPa or higher, more preferably 5 kPa or higher. The reaction time is set within a range of usually 0.1 hour or higher, preferably 0.5 hour or higher, and usually 10 hours or lower, preferably 5 hours or lower, more preferably 3 hours or lower.

[0063] The first-stage reaction is carried out while distilling off the monohydroxy compound derived from the diester compound produced. For example, when diphenyl carbonate is used as the carbonate diester, the monohydroxy compound distilled off in the first-stage reaction is phenol. In the first-stage reaction, lowering the reaction pressure accelerates the polymerization reaction, but also increases the amount of unreacted monomer distilled off. To simultaneously suppress the distillation of unreacted monomer and accelerate the reaction by reducing pressure, it is effective to use a reactor equipped with a reflux condenser. It is particularly effective to use a reflux condenser in the early stages of the reaction when there is a large amount of unreacted monomer.

[0064] In the second-stage reaction, the pressure of the reaction system is gradually reduced from the pressure in the first stage, and the monohydroxy compound subsequently generated is removed from the reaction system, ultimately reducing the pressure of the reaction system to 5 kPa or less, preferably 3 kPa or less. The internal temperature is set within a range of usually 210°C or higher, preferably 220°C or higher, and usually 270°C or less, preferably 260°C or less. The reaction time is set within a range of usually 0.1 hours or higher, preferably 0.5 hours or higher, more preferably 1 hour or higher, and usually 10 hours or less, preferably 5 hours or less, more preferably 3 hours or less. To suppress coloration and thermal degradation and obtain a polycarbonate resin with good hue and thermal stability, the maximum internal temperature throughout all reaction stages should be set to 270°C or less, preferably 265°C or less, and more preferably 260°C or less.

[0065] The transesterification catalyst (hereinafter sometimes simply referred to as catalyst or polymerization catalyst) that can be used during polymerization can have a significant effect on the reaction rate and the color tone and thermal stability of the polycarbonate resin obtained by polycondensation. The catalyst used is not limited as long as it can satisfy the transparency, color, heat resistance, thermal stability, and mechanical strength of the produced polycarbonate resin. Examples of the catalyst include metal compounds of Group 1 or 2 of the long periodic table (hereinafter simply referred to as "Group 1" and "Group 2"), basic boron compounds, basic phosphorus compounds, basic ammonium compounds, amine compounds, and other basic compounds. Preferably, at least one metal compound selected from the group consisting of metals of Group 2 of the long periodic table and lithium is used.

[0066] As the Group 1 metal compound, for example, the following compounds can be used, but other Group 1 metal compounds can also be used: sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride, sodium tetraphenylborate, tetraphenylborate potassium tetraphenylborate, lithium tetraphenylborate, cesium tetraphenylborate, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, dicesium hydrogen phosphate, disodium phenylphosphate, dipotassium phenylphosphate, dilithium phenylphosphate, dicesium phenylphosphate, alcoholates and phenolates of sodium, potassium, lithium and cesium, and disodium, dipotassium, dilithium and dicesium salts of bisphenol A. Of these, it is preferable to use lithium compounds from the viewpoints of polymerization activity and the hue of the resulting polycarbonate resin.

[0067] The Group 2 metal compound may be, for example, the following compounds, although other Group 2 metal compounds may also be used: calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate. Of these, magnesium compounds, calcium compounds, and barium compounds are preferably used, and from the viewpoints of polymerization activity and the hue of the resulting polycarbonate resin, magnesium compounds and / or calcium compounds are more preferably used, and calcium compounds are most preferably used.

[0068] It is possible to use, in combination with the above-mentioned Group 1 metal compound and / or Group 2 metal compound, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound as an auxiliary compound. However, it is particularly preferable to use at least one metal compound selected from the group consisting of metals of Group 2 of the long form periodic table and lithium. The amount of the polymerization catalyst used is usually 0.1 μmol to 300 μmol, preferably 0.5 μmol to 100 μmol, per mole of all dihydroxy compounds used in the polymerization. When at least one metal compound selected from the group consisting of metals of Group 2 of the long periodic table and lithium is used as the polymerization catalyst, particularly when a magnesium compound and / or a calcium compound is used, the amount of metal used is usually 0.4 μmol or more, preferably 0.8 μmol or more, and particularly preferably 1.2 μmol or more, per mole of all dihydroxy compounds. The amount of the polymerization catalyst used is usually 300 μmol or less, preferably 200 μmol or less, and particularly preferably 100 μmol or less.

[0069] When a polyester carbonate resin is produced using a diester compound as a monomer, a transesterification catalyst such as a titanium compound, a tin compound, a germanium compound, an antimony compound, a zirconium compound, a lead compound, an osmium compound, a zinc compound, or a manganese compound can also be used, with or without being used in combination with the basic compound. The amount of these transesterification catalysts used is typically within a range of 1 μmol to 1 mmol, preferably 5 μmol to 800 μmol, and particularly preferably 10 μmol to 500 μmol, in terms of the metal amount, relative to 1 mol of all dihydroxy compounds used in the reaction.

[0070] If the amount of catalyst is too small, the polymerization rate will be slow, and the polymerization temperature will have to be increased accordingly to obtain a polycarbonate resin with the desired molecular weight. As a result, the color of the resulting polycarbonate resin is likely to deteriorate, and unreacted raw materials may volatilize during polymerization, causing the molar ratio of dihydroxy compound to diester compound to be disrupted, resulting in the desired molecular weight not being achieved. On the other hand, if the amount of polymerization catalyst used is too large, undesirable side reactions may occur, which may result in a deterioration in the color of the resulting polycarbonate resin or in discoloration or decomposition of the polycarbonate resin during molding.

[0071] Among the Group 1 metals, sodium, potassium, and cesium can adversely affect the color of polycarbonate resins if present in large amounts. These metals may be present not only in the catalysts used, but also in raw materials or reactors. Regardless of their origin, the total amount of these metal compounds in the polycarbonate resin is preferably 2 μmol or less, preferably 1 μmol or less, and more preferably 0.5 μmol or less, per mol of the total dihydroxy compounds.

[0072] [Method of manufacturing thermoplastic resin molded body] The method for producing a thermoplastic resin molded product of the present invention involves an operation to reduce the reduced viscosity of the resin constituting the molded product by 2.0% or more after 4 hours from the start of production of the extrusion molded product relative to the reduced viscosity of the resin constituting the molded product at the time production of the extrusion molded product begins.

[0073] The method for reducing the reduced viscosity is not particularly limited, and examples thereof include a method of increasing the reaction pressure in the second-stage reaction described later in the production method, and a method of adjusting the molar ratio of all dihydroxy compounds to all diester compounds used in the reaction so as to move away from 1.00. Among these, the method of increasing the reaction pressure in the second-stage reaction is particularly preferred because of the ease of adjustment and the short time it takes for the reduced viscosity to be affected after the conditions are changed.

[0074] The reduction rate of the reduced viscosity of the resin constituting the extrusion molded body after 4 hours from the start of production of the extrusion molded body to the reduced viscosity of the resin constituting the extrusion molded body at the time of starting production of the extrusion molded body is preferably 2.0% or more, more preferably 3.0% or more, and particularly preferably 4.0% or more, from the viewpoint of improving the efficiency of removing foreign matter such as residual resin and discoloration in the polymerization reactor and extruder. Furthermore, from the viewpoint of simplifying adjustment to the final target reduced viscosity, it is preferably 10% or less, more preferably 9.0% or less, and most preferably 8.0% or less. The reduction rate of the reduced viscosity is calculated using the following formula (I): Here, "four hours or more after the start of production" means any time point four hours or more after the start of production, preferably 4 to 8 hours, more preferably 4 to 6 hours. It is also preferable that the reduction rate is as described above at any time point within this time period.

[0075]

number

[0076] The molecular weight of the resin constituting the thermoplastic resin extrusion molded product obtained by the method of the present invention can be expressed by reduced viscosity (η sp / c). The lower limit of the reduced viscosity is preferably 0.30 dL / g or more, more preferably 0.33 dL / g or more, and particularly preferably 0.36 dL / g or more. By adjusting the reduced viscosity to the above lower limit or more, the upper limit of the reduced viscosity is usually 1.2 dL / g or less, preferably 0.8 dL / g or less, and particularly preferably 0.7 dL / g or less. A reduced viscosity within the above range improves the mechanical properties and moldability of the thermoplastic resin. The reduced viscosity of the thermoplastic resin can be measured by the method described in the Examples. The reduced viscosity is measured by precisely weighing the thermoplastic resin extrusion molded product, adjusting the concentration to 0.6 g / dL using methylene chloride as a solvent, and using an Ubbelohde viscometer at a temperature of 20.0°C ± 0.1°C.

[0077] [Reasons why the present invention is effective] The reason why the present invention is effective is not yet clear, but is presumed to be as follows. Contaminants in the early stages of production often consist of resins (resins previously produced in the same equipment) remaining in reactors or extruders that have undergone thermal degradation, resulting in discoloration or gelation. These thermally degraded materials can be cleaned by pouring molten resin through the reactor or extruder. However, the inventors' research has shown that pouring resins with higher melt viscosity results in a higher cleaning effect (i.e., a greater reduction in contaminants) in the same amount of time. It is known that thermoplastic resins have a positive correlation between their molecular weight and melt viscosity, with higher molecular weights resulting in higher melt viscosity. In other words, producing resins with higher molecular weights, i.e., higher melt viscosity, early in production can improve the efficiency of cleaning thermally degraded materials and shorten the time required to reduce the amount of contaminants in the resin to a predetermined value.

[0078] As a specific example of an extrusion molded article, after the polycarbonate resin has been polymerized as described above, it can usually be cooled and solidified, and pelletized with a rotary cutter, etc. The pelletization method is not limited, and examples include a method in which the polycarbonate resin is withdrawn in a molten state from the final polymerization reactor and cooled and solidified in the form of a strand to be pelletized, a method in which the polycarbonate resin is fed in a molten state from the final polymerization reactor to a single-screw or twin-screw extruder, melt-extruded, and then cooled and solidified to be pelletized, or a method in which the polycarbonate resin is withdrawn in a molten state from the final polymerization reactor, cooled and solidified in the form of a strand to be pelletized, and then fed again to a single-screw or twin-screw extruder, melt-extruded, and then cooled and solidified to be pelletized.

[0079] Since polycarbonate resins are suitable for optical applications, it is preferable that the polycarbonate resin contains as little foreign matter as possible. Filtration using a filter is preferably performed to remove foreign matter such as discoloration and gel from the polycarbonate resin obtained by melt polycondensation. In particular, it is preferable to melt-extrude the polycarbonate resin using the above-mentioned vented twin-screw extruder and then filter it using a filter to remove residual monomers, by-product phenol, etc. by devolatilization under reduced pressure, and mix in additives such as a heat stabilizer and a mold release agent.

[0080] The filter can be in any known form, such as a candle type, pleated type, or leaf disc type. The filter's mesh size, as a 99% filtration accuracy, is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 20 μm or less. When it is particularly important to reduce foreign matter, the filter's mesh size is preferably 10 μm or less. However, smaller mesh sizes increase the pressure loss in the filter, potentially causing damage to the filter or causing deterioration of the polycarbonate resin due to shear heating. Therefore, as a 99% filtration accuracy, the filter's mesh size is preferably 1 μm or more. The filter's mesh size is determined in accordance with ISO 16889.

[0081] The polycarbonate resin filtered through the filter is discharged from a die head in the form of strands, cooled and solidified, and pelletized using a rotary cutter or the like. However, when the polycarbonate resin is stranded or pelletized in direct contact with the outside air, it is desirable to carry out the stranding or pelletization in a clean room that is preferably Class 7, more preferably Class 6, as defined in JIS B 9920:2002, in order to prevent contamination by foreign matter from the outside air.

[0082] During pelletization, cooling methods such as air cooling and water cooling are preferably used. The air used during air cooling should be one that has been previously purified of foreign matter using a HEPA filter or similar to prevent re-adhesion of foreign matter. When using water cooling, it is desirable to remove metals from the water using an ion exchange resin or similar, and then use water that has been further purified of foreign matter using a water filter. The mesh size of the water filter used is preferably 10 to 0.45 μm, providing a filtration accuracy of 99% removal.

[0083] When the thermoplastic resin composition of the present invention is used for a film, the thickness of 1 m measured by the method described below 2 The number of foreign particles of 25 μm or more per unit area is preferably 75 or less, more preferably 60 or less, and even more preferably 40 or less.

[0084] [Additives] Thermoplastic resins such as polycarbonate resins may contain commonly used additives such as heat stabilizers, antioxidants, catalyst deactivators, ultraviolet absorbers, light stabilizers, release agents, dyes and pigments, impact modifiers, antistatic agents, lubricants, plasticizers, compatibilizers, nucleating agents, flame retardants, inorganic fillers, and foaming agents, as long as the additives do not impair the object of the present invention.

[0085] (heat stabilizer) Thermoplastic resins such as polycarbonate resins may contain a heat stabilizer, if necessary, to prevent a decrease in molecular weight or deterioration in color during melt processing, etc. Examples of such heat stabilizers include commonly known hindered phenol-based heat stabilizers and / or phosphorus-based heat stabilizers.

[0086] Examples of the hindered phenol compound that can be used include the following compounds: 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,5-di-tert-butylhydroquinone, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxyphenyl)propionate, and 2-tert-butyl-5-(3'-tert-butyl-5'-methyl-2'-hydroxyphenyl)propionate. 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(6-cyclohexyl-4-methylphenol), 2,2'-ethylidene-bis-(2,4-di-tert-butylphenol), tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and the like. Among these, it is preferable to use tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, or 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0087] Examples of phosphorus-based compounds that can be used include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof, as shown below, but phosphorus-based compounds other than these can also be used: triphenyl phosphite, tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, phosphate, bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylenediphosphinate, dimethyl benzenephosphonate, diethyl benzenephosphonate, dipropyl benzenephosphonate. These heat stabilizers may be used alone or in combination of two or more.

[0088] Such a heat stabilizer may be added to a reaction liquid during melt polymerization, or may be added to a thermoplastic resin such as a polycarbonate resin using an extruder and kneaded. When a film is produced by melt extrusion, the heat stabilizer may be added to the extruder to produce a film, or the heat stabilizer may be added in advance to a polycarbonate resin using an extruder and then formed into pellets or the like. The amount of these heat stabilizers is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, and even more preferably 0.001 parts by mass or more, and is preferably 3.0 parts by mass or less, more preferably 2.5 parts by mass or less, and even more preferably 2.0 parts by mass or less, based on 100 parts by mass of the thermoplastic resin such as polycarbonate resin.

[0089] (Catalyst deactivator) Adding an acidic compound to a thermoplastic resin such as a polycarbonate resin to neutralize and deactivate the catalyst used in the polymerization reaction can improve color tone and thermal stability. The acidic compound used as a catalyst deactivator can be a compound having a carboxylic acid group, a phosphoric acid group, or a sulfonic acid group, or an ester thereof. However, it is particularly preferable to use a phosphorus-based compound containing a partial structure represented by the following formula (16) or (17):

[0090] [ka]

[0091] [ka]

[0092] Examples of phosphorus compounds represented by the formula (16) or (17) include phosphoric acid, phosphorous acid, phosphonic acid, hypophosphorous acid, polyphosphoric acid, phosphonate esters, and acidic phosphate esters. Among these, phosphorous acid, phosphonic acid, and phosphonate esters are more effective in deactivating the catalyst and inhibiting coloration, with phosphorous acid being particularly preferred. Examples of phosphonic acids include phosphonic acid (phosphorous acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylenediphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 4-methoxyphenylphosphonic acid, nitrilotris(methylenephosphonic acid), and propylphosphonic anhydride.

[0093] Phosphonate esters include dimethyl phosphonate, diethyl phosphonate, bis(2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, diethyl ethylphosphonate, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl)phosphonate, diethyl vinylphosphonate, and hydroxymethyl Examples thereof include diethyl phosphonate, dimethyl (2-hydroxyethyl)phosphonate, diethyl p-methylbenzylphosphonate, diethyl phosphonoacetic acid, ethyl diethylphosphonoacetate, tert-butyl diethylphosphonoacetate, diethyl (4-chlorobenzyl)phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl phosphonoacetaldehyde diethyl acetal, and diethyl (methylthiomethyl)phosphonate.

[0094] Examples of acidic phosphate esters include phosphate diesters such as dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis(butoxyethyl) phosphate, bis(2-ethylhexyl) phosphate, diisotridecyl phosphate, dioleyl phosphate, distearyl phosphate, diphenyl phosphate, and dibenzyl phosphate, or mixtures of diesters and monoesters, diethyl chlorophosphate, and zinc stearyl phosphate.

[0095] These may be used alone or in any combination and ratio of two or more. If the amount of the phosphorus-based compound added to a thermoplastic resin such as a polycarbonate resin is too small, the catalyst deactivation and discoloration suppression effects will be insufficient. If the amount is too large, the thermoplastic resin such as a polycarbonate resin will discolor, and the thermoplastic resin such as a polycarbonate resin will be more likely to discolor, especially in durability tests under high temperature and high humidity. The amount of the phosphorus-based compound added corresponds to the amount of catalyst used in the polymerization reaction. The amount of phosphorus atoms in the phosphorus-based compound is preferably 0.5 to 5 times the mol, more preferably 0.7 to 4 times the mol, and particularly preferably 0.8 to 3 times the mol, per 1 mol of the metal catalyst used in the polymerization reaction.

[0096] (polymer alloy) For the purpose of improving properties such as mechanical properties and solvent resistance, the polycarbonate resin may be kneaded with one or more synthetic resins, rubbers, elastomers, etc., such as aromatic polycarbonate, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, ABS, AS, polylactic acid, polybutylene succinate, etc., to form a polymer alloy.

[0097] The above-mentioned additives and modifiers can be produced by mixing the above-mentioned components with a thermoplastic resin such as a polycarbonate resin simultaneously or in any order using a mixer such as a tumbler, V-type blender, Nauta mixer, Banbury mixer, kneading roll, or extruder. Among these, kneading using an extruder, particularly a twin-screw extruder, is preferred from the viewpoint of improving dispersibility. [Example]

[0098] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples as long as the gist of the invention is not exceeded.

[0099] <Measurement method> The various physical properties were measured according to the following methods.

[0100] (reduced viscosity) A resin sample was dissolved in methylene chloride to prepare a resin solution with a concentration of 0.6 g / dL. Measurements were carried out at a temperature of 20.0°C ± 0.1°C using an Ubbelohde viscometer manufactured by Moritomo Rika Kogyo Co., Ltd., to measure the solvent transit time t0 and the solution transit time t. The relative viscosity ηrel was calculated using the obtained t0 and t values ​​according to the following formula (i), and the obtained relative viscosity η rel The specific viscosity ηsp was calculated using the following equation (ii). η rel =t / t0 (i) η sp =(η-η0) / η0=η rel -1 (ii) (η0 is the viscosity of the solvent.) Then, the obtained specific viscosity η sp Divide by the concentration c [g / dL] to obtain the reduced viscosity (η sp The higher this value, the larger the molecular weight.

[0101] (Measurement of the number of foreign objects) A single-screw extruder (20 mm diameter, single flight, L / D = 25), a cast film die (150 mm wide), and a cooling roll were used to extrude a film with a thickness of 35 μm ± 5 μm. The extruded film was then measured in-line using a Film Quality Testing System (model FSA100) manufactured by Optical Control Systems. 2 Observe, 1m 2 The number of foreign particles of 25 μm or more per pellet was measured. The number of foreign particles was measured as described above for pellets taken immediately after the start of production, and the results are shown in Table 1 as "initial foreign particles."

[0102] <Raw materials used> The abbreviations and manufacturers of the compounds used in the following Examples and Production Examples are as follows:

[0103] (monomer) SPG: Spiroglycol (Mitsubishi Gas Chemical Company, Inc.) ISB: Isosorbide (manufactured by Rocket Fleuret) TCDDM: Tricyclodecane dimethanol [OQ] BPFM: bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane (BPFM was synthesized by the method described in JP 2015-25111 A.)

[0104] [ka]

[0105] DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation) PHL: Phenol (Mitsubishi Chemical Corporation)

[0106] (polymerization catalyst) Calcium acetate monohydrate (Kanto Chemical Co., Ltd.) Calcium acetate monohydrate was dissolved in demineralized water to prepare an aqueous solution of a predetermined concentration. (Catalyst deactivator) Phosphonic acid (Tokyo Chemical Industry Co., Ltd.) (Heat stabilizer (antioxidant)) Irganox 1010: Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (BASF)

[0107] Example 1 As shown in Figures 1 and 2, a continuous polymerization system consisting of three vertical stirred reactors, one horizontal stirred reactor, and a twin-screw extruder was used to polymerize polycarbonate resin. SPG was dissolved in PHL to form a 45 wt% solution (Figure 1(j)). ISB was melted in (2b), and BPFM and DPC were melted in (3d). These were then continuously fed into the first vertical stirred reactor so that the molar and weight ratios of each structural unit in the resulting polycarbonate resin were as follows: SPG / ISB / BPFM / DPC = 0.266 / 0.734 / 0.126 / 0.874 (molar ratio), and SPG / ISB / PBFM / DPC = 30.0 / 39.5 / 21.4 / 9.1 (wt%). Simultaneously, an aqueous solution of calcium acetate monohydrate was fed into the first vertical stirred reactor as a catalyst at a ratio of 12 μmol per 1 mole of total dihydroxy compounds. The liquid level was kept constant by controlling the valve opening on the transfer pipe at the bottom of the first vertical stirred reactor so that the average residence time in the reactor was 90 minutes. The reaction liquid discharged from the bottom of the reactor was then continuously supplied to the second vertical stirred reactor, the third vertical stirred reactor, and the fourth horizontal stirred reactor, one after the other. The first and second vertical stirred reactors were equipped with reflux condensers to prevent the distillation of unreacted monomers.

[0108] The reaction temperature, internal pressure, and residence time of each reactor at the initial stage of production start-up were as follows: first vertical stirred reactor: 195°C, 26.7 kPa, 90 minutes; second vertical stirred reactor: 205°C, 20 kPa, 60 minutes; third vertical stirred reactor: 220°C, 10 kPa, 60 minutes; and fourth horizontal stirred reactor: 235°C, 1.75 kPa, 130 minutes.

[0109] The resin extracted from the fourth horizontal stirred reactor was then fed in a vented twin-screw extruder in a molten state. The polycarbonate resin that had passed through the extruder was filtered, still in a molten state, through a 10 μm ultipleat candle-type filter (Pall Corporation) to remove foreign matter. The resin was then discharged in the form of strands from the die, cooled with water, solidified, and pelletized with a rotary cutter to obtain polycarbonate resin molded products. After the start of resin molding production, the internal pressure of the fourth horizontal stirred reactor was finely adjusted during operation so that the reduction viscosity reduction rate relative to the pellets immediately after the start of molded product production was 2.0% or more.

[0110] The extruder had three vacuum vents, where residual low-molecular-weight components in the resin were removed by volatilization. Just before the second vent, 2000 ppm of water was added to the resin, and water was poured in to remove the volatilization. Just before the third vent, 0.1 parts by weight of Irganox 1010 was added per 100 parts by weight of polycarbonate resin.

[0111] The pelletized polycarbonate resin was sampled immediately after the start of molding production and 5 hours after the start of molding production, and subjected to the various evaluations described above.

[0112] <Example 2> As shown in Figures 1 and 2, a continuous polymerization system consisting of three vertical stirred reactors, one horizontal stirred reactor, and a twin-screw extruder was used to polymerize polycarbonate resin. ISB, TCDDM, and DPC were melted in separate tanks and continuously fed into the first vertical stirred reactor so that the molar ratios of the structural units in the resulting polycarbonate resin were as follows: ISB / TCDDM / DPC = 0.700 / 0.300 / 1.010 (molar ratio), ISB / TCDDM / DPC = 53.9 / 31.1 / 15.0 (wt%). Simultaneously, an aqueous solution of calcium acetate monohydrate was fed into the first vertical stirred reactor as a catalyst at a ratio of 1.5 μmol per mol of total dihydroxy compounds. The liquid level was maintained constant by controlling the valve opening of the transfer pipe at the bottom of the reactor so that the average residence time in the first vertical stirred reactor was 90 min. The reaction liquid discharged from the bottom of the reactor was then continuously supplied to the second vertical stirred reactor, the third vertical stirred reactor, and the fourth horizontal stirred reactor in succession. The first and second vertical stirred reactors were equipped with reflux condensers, and by adjusting the reflux ratio, the distillation of unreacted dihydroxy compound and DPC was suppressed.

[0113] The reaction temperature, internal pressure, and residence time of each reactor during production start-up were as follows: first vertical stirred reactor: 190°C, 26.7 kPa, 120 minutes; second vertical stirred reactor: 195°C, 12 kPa, 90 minutes; third vertical stirred reactor: 210°C, 5 kPa, 45 minutes; and fourth horizontal stirred reactor: 225°C, 1.75 kPa, 100 minutes.

[0114] The resin extracted from the fourth horizontal stirred reactor was then fed into a vented twin-screw extruder in its molten state. The polycarbonate resin that had passed through the extruder was filtered, still in its molten state, through a 10 μm ultipleat candle-type filter (Pall Corporation) to remove foreign matter. The resin was then discharged in the form of strands from the die, cooled with water, solidified, and pelletized with a rotary cutter to obtain polycarbonate resin molded products. After the start of resin molding production, the internal pressure of the fourth horizontal stirred reactor was finely adjusted during operation so that the reduced viscosity reduction rate relative to the pellets immediately after the start of molded product production was 2.0% or more.

[0115] The extruder had three vacuum vents, where residual low-molecular-weight components in the resin were removed by volatilization. Just before the second vent, 2000 ppm of water was added to the resin, and water was poured in to remove the volatilization. Just before the third vent, 0.1 parts by weight of Irganox 1010 was added per 100 parts by weight of polycarbonate resin.

[0116] The pelletized polycarbonate resin was sampled immediately after the start of molding production and 5 hours after the start of molding production, and subjected to the various evaluations described above.

[0117] <Comparative Example 1> The same procedures as in Example 1 were carried out except that the internal pressure of the fourth horizontal stirred reactor at the initial stage of production startup was changed to 2.10 kPa.

[0118] <Comparative Example 2> The same procedures as in Example 1 were carried out except that the internal pressure of the fourth horizontal stirred reactor at the initial stage of production startup was changed to 2.50 kPa.

[0119] [Table 1] [Explanation of symbols]

[0120] 1a: SPG flexible container 1b: SPG receiving hopper 1c: SPG air blower 1d: SPG raw material silo 1e: SPG weigh feeder 1F: PHL melting tank 1g: PHL metering pump 1h: Catalyst aqueous solution tank 1i: Catalyst aqueous solution metering pump 1j:SPG / PHL raw material dissolution tank 1k:SPG·PHL metering pump 2a:ISB flexible container 2b:ISB dissolution tank 2c:ISB storage tank 2d:ISB metering pump 3a: BPFM flexible container 3b: Melting DPC tank 3c: DPC metering pump 3d:BPFM / DPC raw material dissolution tank 3e: Transfer pump 3f: BPFM / DPC storage tank 3g: BPFM·DPC metering pump 4a: Static mixer 4b: Filter 4c: Catalyst aqueous solution tank 4d: Catalyst aqueous solution metering pump 5a:TCDDM storage tank 5b: TCDDM metering pump 21a: First vertical stirred reactor 21b: Reflux condenser 21c: Second vertical stirred reactor 21d: Reflux condenser 21e: Third vertical stirred reactor 21f: Gear pump 21g: Fourth horizontal stirred reactor 21h: Gear pump 22a: Vacuum vent type twin screw extruder 22b: Gear pump 22c: Polymer filter 22d: Dice 23a: Distillate recovery tank 23b: Distillate metering pump 23c: First distillation column 23d: Metering pump 23e: Reflux condenser 23f: Second distillation tower 23g: Metering pump 23h: Reflux condenser

Claims

1. A method for producing a thermoplastic resin molded body, in which a thermoplastic resin is extruded from an extruder to continuously produce an extrusion molded body, characterized in that the reduced viscosity is reduced by 2.0% or more after 4 hours from the start of production of the molded body compared to the reduced viscosity at the start of production of the molded body.

2. The method for producing a thermoplastic resin molded article according to claim 1, wherein the thermoplastic resin contains a structural unit represented by the following formula (1): 【Chemical 1】

3. 3. The method for producing a thermoplastic resin molded article according to claim 1, wherein the thermoplastic resin molded article is a polycarbonate resin.

4. 3. The method for producing a thermoplastic resin molded article according to claim 1, wherein the thermoplastic resin further contains a structural unit derived from at least one compound selected from the group consisting of an aliphatic dihydroxy compound, an alicyclic dihydroxy compound, a dihydroxy compound having a heterocyclic structure, an oxyalkylene glycol, an aromatic dihydroxy compound, and a diester compound.

5. The method for producing a thermoplastic resin molded article according to claim 1 or 2, wherein the thermoplastic resin contains at least one structural unit represented by the following formulas (2) to (4): 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】

6. The method for producing a thermoplastic resin molded article according to claim 1 or 2, wherein the thermoplastic resin further contains a structural unit represented by the following formula (5) and / or the following formula (6): 【Chemistry 5】 (However, in the above formula (5), R １ ~R ３ each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R ４ ~R ９ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R ４ ~R ９ may be the same or different, R ４ ~R ９ At least two adjacent groups among these may be bonded to each other to form a ring.) 【Chemistry 6】 (However, in the above formula (6), R １ ~R ３ each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R ４ ~R ９ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R ４ ~R ９ may be the same or different, R ４ ~R ９ At least two adjacent groups among these may be bonded to each other to form a ring.)

7. The thermoplastic resin contains a structural unit represented by the following formula (1): ２ A thermoplastic resin film having 75 or less foreign particles of 25 μm or more per film. 【Chemistry 7】

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