Resin composition containing polyarylate resin and polycarbonate resin

Abstract

Provided is a composition containing a polyarylate resin and a polycarbonate resin, the color tone of the resin composition itself being sufficiently good, and coloring due to thermal degradation during melt molding being sufficiently suppressed. The resin composition contains a polyarylate resin (A) and a polycarbonate resin (B), the polyarylate resin (A) contains an aromatic dicarboxylic acid component and a dihydric phenol component as monomer components, the mass ratio (A / B) of the polyarylate resin (A) to the polycarbonate resin (B) is 99 / 1-1 / 99, and the formate content is 0.1-2.0 ppm.

Description

Technical Field

[0001] The present invention relates to a resin composition containing a polyarylate resin and a polycarbonate resin. Background Art

[0002] The polyarylate resin composed of an aromatic dicarboxylic acid component and a diphenol component is amorphous, and is a resin that is transparent and has excellent heat resistance. A resin composition in which a polycarbonate resin is blended with a polyarylate resin is widely used in the fields of electric and electronic, automotive, machinery, etc. for its molded article because of its excellent heat resistance, transparency, moldability, mechanical strength, and dimensional stability. A resin composition in which glass fiber is blended in the above resin composition is used for lens parts of digital cameras, disk centering parts of optical disk drives, etc. because of its particularly excellent mechanical properties and dimensional stability of the molded article. In addition, a resin composition in which spherical silica is blended in the above resin composition is used for various precision parts such as lens parts of digital cameras, lens parts of mobile phones with cameras, and centering parts for recording disks because of its particularly excellent dimensional stability and impact resistance of the molded article. In addition, a resin composition in which a specific silane compound is blended in the above resin composition is used for various automotive parts such as reflector lamp applications because of its particularly excellent heat and humidity resistance of the molded article.

[0003] However, due to its excellent heat resistance, the polyarylate resin has a higher melting molding processing temperature than general-purpose polymers, and has the property of being easily thermally deteriorated and colored during melting. In addition, if the molded article is used at a high temperature for a long time, it also has a tendency to turn yellow. Therefore, for a resin composition containing a polyarylate resin and a polycarbonate resin, there are sometimes limitations in applications where the color tone of mechanical parts, automotive parts, etc. used is required and the color tone change over time is not desired.

[0004] In order to solve the above problems, various methods of adding modifiers such as dye pigments and antioxidants during melt molding or melt kneading have been studied. For example, Patent Document 1 proposes a method of melt kneading a dye pigment and a sulfur-containing carboxylic acid ester in a polycarbonate resin. In addition, for example, Patent Document 2 proposes a method of melt kneading a phenolic compound, a phosphorus compound, and a lactone compound in a polyarylate resin. However, these methods are only modified based on the additives added during melt kneading. Therefore, from the viewpoints of reducing the types and amounts of additives used, it is necessary to improve the color tone and thermal discoloration properties of the polyarylate resin itself.

[0005] In order to improve the hue and thermal discoloration properties of polyarylate resins themselves, efforts are required at the stage of manufacturing polyarylate resins from raw materials. As polymerization methods for polyarylate resins, melt polymerization, solution polymerization, and interfacial polymerization are known. In particular, for the interfacial polymerization method, even for polymers with high heat resistance, the reaction proceeds to a high degree of polymerization at a temperature close to room temperature. Therefore, the resulting resin has excellent hue and fully utilizes the inherent properties of polyarylate resins, namely transparency and heat resistance, and is thus preferred.

[0006] In addition, as described in Patent Document 3, not limited to the interfacial polymerization method, adding a reducing agent such as sodium dithionite in the polymerization step is effective in preventing the discoloration of the diphenol-based compound as a monomer and further preventing the coloring of the resulting polyarylate resin.

[0007] On the other hand, Patent Document 4 discloses the following technique: an aromatic polycarbonate excellent in hue and heat resistance is produced by using sodium dithionite as a reducing agent added in the polymerization step.

[0008] In addition, Patent Document 5 discloses the following technique: a polycarbonate excellent in hue is produced by making the sodium formate contained in the sodium dithionite used in the production of polycarbonate be 0.3% by weight or less. In particular, Patent Document 5 mentions that if the sodium formate contained in the sodium dithionite used in the production of polycarbonate is more than 0.3% by weight, the hue of the resin during heating deteriorates.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] Patent Document 1: Japanese Patent Laid-Open No. 4-120164

[0012] Patent Document 2: Japanese Patent Laid-Open No. 2002-265766

[0013] Patent Document 3: Japanese Patent Publication No. 1-18939

[0014] Patent Document 4: Japanese Patent Laid-Open No. 7-233253

[0015] Patent Document 5: Japanese Patent Laid-Open No. 2009-096937 Summary of the Invention

[0016] However, in the prior art, the following problems sometimes occur.

[0017] It is impossible to obtain a polyarylate resin with sufficiently excellent hue, and in a resin composition mixed with a polycarbonate resin, it is impossible to sufficiently suppress the coloring caused by thermal deterioration during melt molding.

[0018] An object of the present invention is to provide a composition containing a polyarylate resin and a polycarbonate resin, which has a sufficiently good hue of the resin composition itself and can sufficiently suppress coloring caused by thermal deterioration during melt molding.

[0019] The inventors of the present invention repeatedly conducted in-depth research to solve this problem, and as a result, found that the above object can be achieved by making the resin composition contain an appropriate amount of formate, thereby completing the present invention.

[0020] The gist of the present invention is as follows.

[0021] <1> A resin composition containing a polyarylate resin (A) and a polycarbonate resin (B),

[0022] The polyarylate resin (A) contains an aromatic dicarboxylic acid component and a diphenol component as monomer components,

[0023] The mass ratio (A / B) of the polyarylate resin (A) to the polycarbonate resin (B) is 99 / 1 to 1 / 99,

[0024] The content of formate is 0.1 to 2.0 ppm.

[0025] <2> The polyarylate resin according to <1>, wherein the above formate is sodium formate.

[0026] <3> The resin composition according to <1> or <2>, wherein the resin composition has a color difference a value of -1.0 to 0.5.

[0027] <4> The resin composition according to any one of <1> to <3>, wherein a molded plate with a thickness of 3 mm obtained by injection molding the resin composition has a YI value of 22 or less.

[0028] <5> The resin composition according to any one of <1> to <4>, wherein the content of the above formate is 0.1 to 0.8 ppm.

[0029] <6> A method for manufacturing a resin composition, when polymerizing an aromatic dicarboxylic acid component and a diphenol component, adding a sodium dithionite having a formate content of 0.4 to 1.5% by mass in an amount of 0.05 to 4.0% by mass based on the above diphenol component to manufacture the polyarylate resin (A),

[0030] Then, the polycarbonate resin (B) is further mixed.

[0031] <7> The method for manufacturing a resin composition according to <6>, wherein the above sodium dithionite is sodium dithionite manufactured by the formate method.

[0032] <8> The method for producing the resin composition according to <6> or <7>, wherein the resin composition according to any one of <1> to <5> is produced.

[0033] According to the present invention, it is possible to provide a resin composition containing a polyarylate resin and a polycarbonate resin, which has a sufficiently good hue of the resin composition itself and can sufficiently suppress coloring due to thermal deterioration during melt molding. Detailed Description

[0034] The resin composition of the present invention contains a polyarylate resin (A) and a polycarbonate resin (B).

[0035] The polyarylate resin (A) used in the present invention is an aromatic polyester resin obtained from an aromatic dicarboxylic acid component (including its derivatives) and a diphenol component, and contains these components as monomer components. Therefore, the polyarylate resin (A) can also be expressed as containing residues of an aromatic dicarboxylic acid component and a diphenol component. The structure of the polyarylate resin (A) is not particularly limited, and the present invention can also be applied to polyarylate resins of any structure. A derivative refers to an organic compound in which the carboxyl group of an aromatic dicarboxylic acid is substituted with a more reactive substituent, and examples include acyl halides having an acyl halide group described later.

[0036] The aromatic dicarboxylic acid component for introducing the aromatic dicarboxylic acid residue constituting the polyarylate resin (A) is an organic compound containing an aromatic ring and having two carboxyl groups per molecule. The carboxyl group can also be an acyl halide group. An acyl halide group is a group in which the hydroxyl group of a carboxyl group is substituted with a halogen atom. Specific examples of such an aromatic dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, chlorophthalic acid, nitrophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, methylterephthalic acid, 4,4'-biphenyldicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-diphenylisopropylidenedicarboxylic acid, 1,2-bis(4-carboxyphenoxy)ethane, sodium 5-sulfoisophthalate, biphenyldicarboxylic acid, and their derivatives (such as acyl halides). These aromatic dicarboxylic acids can be used alone or in combination of two or more. Among them, from the viewpoint of further improving the hue and color resistance, it is preferable that the polyarylate resin (A) contains at least one, preferably both, of terephthalic acid and isophthalic acid.

[0037] In the present specification, the hue is the hue of the resin composition itself, which is a characteristic of having a small color difference a value based on a colorimetric color difference meter.

[0038] Color fastness is a property that can more fully suppress the coloring of the resin composition caused by thermal deterioration during melt molding, and is a property in which the yellow index (YI) value of the obtained molded product based on a color tone measuring device is small.

[0039] The total content of terephthalic acid and isophthalic acid in the polyarylate resin (A) is not particularly limited. From the viewpoint of further improving the color tone and color fastness, it is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, particularly preferably 95% by mass or more, and sufficiently preferably 100% with respect to the total amount of the aromatic dicarboxylic acid component. The total content of terephthalic acid and isophthalic acid may also be the total content of the residues of terephthalic acid and isophthalic acid.

[0040] When the polyarylate resin (A) contains terephthalic acid and isophthalic acid as the aromatic dicarboxylic acid component, their contents are not particularly limited. From the viewpoint of further improving the color tone and color fastness, the mass ratio of terephthalic acid / isophthalic acid is preferably 0 / 100 to 100 / 0, more preferably 20 / 80 to 80 / 20, still more preferably 40 / 60 to 60 / 40, particularly preferably 45 / 55 to 55 / 45, and sufficiently preferably 50 / 50. The contents of terephthalic acid and isophthalic acid may also be the contents of the residues of terephthalic acid and isophthalic acid.

[0041] The diphenol component for introducing the diphenol residue constituting the polyarylate resin (A) is an organic compound having 2 phenolic hydroxyl groups per molecule. The phenolic hydroxyl group is a hydroxyl group directly bonded to an aromatic ring. Specific examples of such a diphenol component include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C), 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxybiphenyl [4,4'-biphenol], 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC), 4,4'-(1,3-dimethylbutylidene)diphenol, resorcinol, and the like. These compounds can be used alone or in combination of two or more. From the viewpoint of further improving the hue and color fastness, the polyarylate resin (A) preferably contains one or more diphenol components selected from bisphenol A, bisphenol C, bisphenol Z, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, and bisphenol TMC, and more preferably contains bisphenol A.

[0042] The content of bisphenol A in the polyarylate resin (A) is not particularly limited. From the viewpoint of further improving the hue and color fastness, it is preferably 1 to 100% by mass, more preferably 20 to 100% by mass, further preferably 40 to 100% by mass, particularly preferably 60 to 100% by mass, and sufficiently preferably 100% by mass, based on the total amount of the diphenol component. The content of bisphenol A may also be the content of the residue of bisphenol A.

[0043] The polyarylate resin (A) can contain a part of the diphenol component in a manner substituted with at least one diol component selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, octylene glycol, dodecylene glycol, neopentyl glycol, cyclohexanediol, 1,4-dihydroxymethylcyclohexane, etc., within the range not impairing the characteristics and effects of the present invention.

[0044] The content of the above-mentioned diol component in the polyarylate resin (A) is not particularly limited. For example, it can be 50% by mass or less relative to the total amount of the diphenol component. From the viewpoint of further improving the hue and color fastness, it is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, particularly preferably 1% by mass or less, and sufficiently preferably 0% by mass. The content of the diol component can also be the content of the residue of the diol component.

[0045] The polyarylate resin (A) can further contain a polyfunctional monomer component having 3 or more functional groups within the range that does not impair the characteristics and effects of the present invention. When the polyarylate resin (A) contains a polyfunctional monomer component having 3 or more functional groups, a branched structure is introduced into the polyarylate resin (A). Examples of the polyfunctional monomer component having 3 or more functional groups include tricarboxylic acid components such as 1,3,5-benzenetricarboxylic acid; triol components such as 4,4',4''-trihydroxytriphenylmethane.

[0046] The content of the polyfunctional monomer component in the polyarylate resin (A) is not particularly limited. For example, it can be 20% by mass or less relative to the total amount of the diphenol component and the aromatic dicarboxylic acid component. From the viewpoint of further improving the hue and color fastness, it is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less, particularly preferably 1% by mass or less, and sufficiently preferably 0% by mass. The content of the polyfunctional monomer component can also be the content of the residue of the polyfunctional monomer component.

[0047] The polyarylate resin (A) contains a capping agent, and the molecular weight can be adjusted. Examples of the capping agent include monohydric phenols selected from phenol, cresol, p-tert-butylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, cumylphenol, etc.; monohydric acid chlorides such as benzoyl chloride, methanesulfonyl chloride, phenyl chloroformate, etc.; monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, pentanol, hexanol, dodecanol, stearyl alcohol, benzyl alcohol, phenethyl alcohol, etc.; monocarboxylic acids such as acetic acid, propionic acid, octanoic acid, cyclohexanecarboxylic acid, benzoic acid, methylbenzoic acid, phenylacetic acid, p-tert-butylbenzoic acid, p-methoxyphenylacetic acid, etc. From the viewpoint of further improving the hue and color fastness, the capping agent is preferably monohydric phenols (particularly p-tert-butylphenol).

[0048] The content of the capping agent in the polyarylate resin (A) is not particularly limited. From the viewpoint of further improving the hue and color fastness, relative to 100 parts by mass of the diphenol component, it is preferably 0.2 to 20 parts by mass, more preferably 0.6 to 10 parts by mass, still more preferably 1.2 to 6 parts by mass, and particularly preferably 2 to 5 parts by mass. The content of the capping agent can also be the content of the residue of the capping agent.

[0049] Generally, from the viewpoints of mechanical properties and the operability during melt molding and melt kneading, the inherent viscosity of the polyarylate resin (A) is preferably 0.40 to 1.30 dl / g, more preferably 0.45 to 1.10 dl / g, still more preferably 0.50 to 0.90 dl / g, particularly preferably 0.50 to 0.80 dl / g, and most preferably 0.50 to 0.70 dl / g.

[0050] The inherent viscosity (ηinh) is an index of molecular weight and is the value measured by the following method. Using 1,1,2,2 - tetrachloroethane as the solvent, a resin solution of the polyarylate resin (A) is prepared to reach a concentration of 1 g / dl, and the relative viscosity (ηrel) is measured under the condition of a temperature of 25°C. The inherent viscosity is calculated from the obtained relative viscosity by the following formula.

[0051] ηinh (dl / g) = Ln(ηrel) / c (c: concentration)

[0052] The polymerization method of the polyarylate resin (A) is not particularly limited as long as the obtained polyarylate resin (A) has the above characteristic values, and it can be a known method. For example, the following methods can be cited:

[0053] · A solution polymerization method in which a diacyl halide containing an aromatic dicarboxylic acid component reacts with a diol containing a diphenol component in an organic solvent;

[0054] · A melt polymerization method in which the above - mentioned dicarboxylic acid and diol are heated in the presence of acetic anhydride and diallyl carbonate; and

[0055] · An interfacial polymerization method in which a diacyl halide dissolved in an organic solvent immiscible with water is mixed with a diol dissolved in an aqueous alkali solution.

[0056] Regarding the polymerization method of the polyarylate resin (A) used in the present invention, from the viewpoint of further improving the hue and color resistance, since the reaction is carried out at a relatively low temperature to a high degree of polymerization, the interfacial polymerization method is preferred.

[0057] In the case of applying the interfacial polymerization method, the organic solvent used is not particularly limited as long as it is immiscible with water and the diacyl halide used and the resulting polyarylate resin (A) are soluble. As such an organic solvent, for example, aliphatic chlorine - based solvents such as dichloromethane, 1,2 - dichloroethane, chloroform, 1,1,1 - trichloroethane, and tetrachloroethane; aromatic chlorine - based solvents such as chlorobenzene and o - dichlorobenzene; and their mixtures can be used. In the separation and drying process of the resulting polyarylate resin (A), it is only necessary to avoid using an organic solvent with too high a boiling point. Among them, as the organic solvent, aliphatic chlorine - based solvents (especially dichloromethane) are preferred.

[0058] In the interfacial polymerization method, as the reducing agent, preferably use the dithionite produced by the formate method. This is because: it is easy to achieve the formate content in the resin composition described later, and as a result, it is possible to easily produce a resin composition excellent in hue and color fastness.

[0059] The dithionite may be an alkali metal salt of dithionous acid. For example, sodium dithionite (alias: sodium hydrosulfite), potassium dithionite, etc. can be cited. From the viewpoint of further improving the hue and color fastness, the dithionite is preferably sodium dithionite.

[0060] From the viewpoint of further improving the hue and color fastness, the dithionite is preferably sodium dithionite produced by the formate method. The dithionite produced by a method other than the formate method (for example, the electrolysis method) does not contain formate itself.

[0061] The formate method refers to a method of producing sodium dithionite using formate. Specifically, in this method, formate is dissolved in an aqueous alcohol (for example, aqueous methanol), and sodium hydroxide and sulfurous anhydride are added and reacted.

[0062] From the viewpoint of further improving the hue and color fastness, the content of formate contained in the dithionite (especially the content of sodium formate contained in sodium dithionite produced by the formate method) is preferably 0.4 to 1.5% by mass, more preferably 0.4 to 1.0% by mass, still more preferably 0.5 to 1.0% by mass, and particularly preferably 0.5 to 0.8% by mass. Whether the content of this formate (especially sodium formate) is too small or too large, it is difficult to control the formate content in the obtained polyarylate resin (A). As a result, it is difficult to achieve the formate content of the resin composition described later, and it is impossible to sufficiently suppress the coloring caused by thermal deterioration during melt molding. The content of this formate (especially sodium formate) is the ratio relative to the total amount of dithionite (especially the total amount of sodium dithionite). The total amount of dithionite refers to the total amount of dithionite and the formate contained in the dithionite. Especially when the dithionite contains by-products and decomposition products, it is the total amount including the by-products and decomposition products. The total amount of sodium dithionite refers to the total amount of sodium dithionite and the sodium formate contained in the sodium dithionite. Especially when the sodium dithionite contains by-products and decomposition products, it is the total amount including the by-products and decomposition products.

[0063] In the method for quantifying formate contained in dithionite (particularly the method for quantifying formate contained in sodium dithionite produced by the sodium formate method), examples of the method include the method specified in "Specifications for Food Additives, etc. (Ministry of Health and Welfare Notification No. 370 of 1969), Additive 2 (starting from November 30, 2017)", the method for detecting organic acids based on ion chromatography, etc. In the present invention, the method for detecting organic acids based on ion chromatography is adopted.

[0064] The content of formate contained in dithionite (particularly sodium dithionite) can be controlled, for example, by washing and purifying dithionite (particularly the obtained sodium dithionite) with an aqueous methanol solution. Specifically, by adjusting the number of washing times in the aqueous methanol solution and the methanol concentration of the aqueous methanol solution, the content of formate (particularly sodium formate) can be controlled. For example, the more the number of washing times, the less the content of formate (particularly sodium formate). On the other hand, the fewer the number of washing times, the more the content of formate (particularly sodium formate). In addition, for example, the higher the methanol concentration of the aqueous methanol solution, the less the content of formate (particularly sodium formate). On the other hand, the lower the methanol concentration of the aqueous methanol solution, the more the content of formate (particularly sodium formate).

[0065] From the viewpoint of further improving the hue and colorfastness, the addition amount of the reducing agent (e.g., dithionite (particularly sodium dithionite produced by the sodium formate method)) is preferably 0.05 to 4.0% by mass, more preferably 0.1 to 2.0% by mass, still more preferably 0.2 to 1.5% by mass, sufficiently preferably 0.2 to 1.1% by mass, and even more sufficiently preferably 0.3 to 0.8% by mass, relative to the mass of the diphenol component used. Whether the addition amount of the reducing agent is too small or too large, it is difficult to control the formate content of the polyarylate resin (A). As a result, it is difficult to achieve the formate content of the resin composition described below. For example, when the addition amount is less than 0.05% by mass, the effect of preventing coloring of the diphenol component is not sufficient, and coloring due to thermal deterioration during melt molding cannot be sufficiently suppressed. On the other hand, if the addition amount is increased to more than 4.0% by mass, the formate content of the resin composition is too high, and coloring due to thermal deterioration during melt molding cannot be sufficiently suppressed.

[0066] In the interfacial polymerization method, a polymerization catalyst can also be used. Examples of the polymerization catalyst for the interfacial polymerization method include tertiary amines such as trimethylamine, triethylamine, tri-n-butylamine, tri-n-propylamine, triisopropylamine, trihexylamine, tridecylamine, N,N-dimethylcyclohexylamine, pyridine, quinoline, and dimethylaniline; quaternary ammonium salts such as benzyltrimethylammonium halide, benzyltriethylammonium halide, benzyltri-n-propylammonium halide, and benzyltri-n-butylammonium halide; benzyltrimethylhalide tetramethylhalide benzyltriethylhalide Benzyltri-n-butyl halide Tetra-n-butyl halide Benzyltriphenyl halide Tetraphenyl halide and other quaternary salts; crown ethers such as 18-crown-6, benzo-18-crown-6, dibenzo-18-crown-6, 15-crown-5. From the viewpoints of polymerization rate and price, quaternary ammonium salts (especially benzyltrimethylammonium halide and benzyltri-n-butylammonium halide) are particularly preferred.

[0067] The amount of the polymerization catalyst used is not particularly limited. From the viewpoint of further improving the hue and color fastness, it is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and still more preferably 0.1 to 1.5% by mass relative to the diphenol component.

[0068] When producing a polyarylate resin by the interfacial polymerization method, the following method is preferably employed.

[0069] A water layer is obtained by dissolving a diphenol component, a terminator, a reducing agent, and a polymerization catalyst in an alkaline aqueous solution. In addition, an organic layer is obtained by dissolving an aromatic dicarboxylic acid component in an organic solvent. The two immiscible solutions (the above-mentioned water layer and organic layer) are mixed under strong stirring, and the polymerization reaction is carried out until a high degree of polymerization is reached by the interlayer migration of the diphenol component and the terminator component in the water layer. After the reaction is completed, stirring is stopped, and after separating into an organic layer in a state where the produced polyarylate resin is dissolved and a water layer in which salts, unreacted monomers, etc. as by-products are dissolved, the organic layer is neutralized with an inorganic acid such as acetic acid and phosphoric acid.

[0070] The neutralized organic layer contains unreacted monomers, low molecular weight substances of the polyarylate resin, salts of by-products, and other impurities. In order to remove them, the organic layer is thoroughly washed with pure water by methods such as the standing separation method and the centrifugation method. Both the standing separation method and the centrifugation method utilize extracting various impurities contained in the organic layer into pure water, and either method can be appropriately adopted. By washing with pure water, the formate content in the polyarylate resin can be reduced. In addition, by increasing the number of times and the washing time of this washing with pure water, the formate content can be further reduced.

[0071] In the process of granulating polyarylate resin with an organic layer in which polyarylate resin is dissolved and which has been sufficiently washed, there are a warm water granulation method in which organic solvent is distilled off in warm water, a kneading method in which heating is carried out using a kneader or the like to evaporate the organic solvent and the residual polymer is pulverized, a spray drying method in which the organic solvent is sprayed using a sprayer and the organic solvent is instantaneously evaporated, a reprecipitation method in which an organic solvent solution is put into a poor solvent for polyarylate resin to cause precipitation and deposition of polymer components, and the like. Any method can be appropriately adopted, but from the viewpoints of the properties of the particles obtained in the present invention and the simplicity of the apparatus, etc., it is preferred to carry out using the warm water granulation method.

[0072] When dichloromethane is used as the organic solvent, in warm water granulation, warm water at 50 °C is charged into a warm water jacket box equipped with a stirrer, stirring is carried out, and further, while circulating the warm water drawn out from the bottom of the box and introduced into a wet pulverizer and then returned to the same box, an organic solvent solution in which polyarylate resin is dissolved is supplied, and while maintaining the liquid temperature in the box at 50 °C, the organic solvent is distilled off to granulate the polyarylate resin. In the wet pulverizer of the circulating production line, care is taken to avoid generating large particles to obtain a polyarylate / warm water slurry, and this slurry is drawn out through a filter to obtain only polyarylate resin powder particles.

[0073] The polyarylate resin powder particles obtained by granulation are dried using an appropriate dryer and by an appropriate method according to the production volume, etc. At this time, when the drying temperature is higher than 140 °C, since the vaporized dichloromethane undergoes thermal decomposition to generate hydrogen chloride, the inner wall of the dryer is severely corroded, so it is preferred to operate at 140 °C or lower (especially 120 - 135 °C). By setting the drying temperature to 120 - 135 °C, the formate content of the polyarylate resin can be within the above range, and moisture and dichloromethane components can be sufficiently removed.

[0074] When the polyarylate resin (A) has a powdery granular shape (or the form of powder particles), the particle size of the particles is 0.7 - 5.0 mm (in some cases, a part contains fine powder). Further, the polyarylate resin (A) may also contain a part in which two or more particles are pressed against each other.

[0075] The particle size of the polyarylate resin (A) is a value obtained by measuring any 50 particles of the polyarylate resin (A) using a microscope (VH - X6000) manufactured by KEYENCE Corporation.

[0076] The polycarbonate resin (B) is not particularly limited. For example, known polycarbonate resins composed of bisphenol residue units and carbonate residue units can be cited. As commercially available products of polycarbonate (B), Sumika Polycarbonate's SD POLYCA301-4, 301-15, 301-30, Teijin's Panlite L-1225, L-1250, etc. can be cited. The polycarbonate resin (B) can be used alone or in combination of two or more. As the manufacturing method of the polycarbonate resin (B), for example, known methods such as the interfacial polymerization method and the melt polymerization method can be cited. In addition, recycled products of polycarbonate resins used in automotive interior parts, headlamps, building materials, etc. can also be used. The recycling method is not particularly limited to chemical recycling, material recycling, etc. As commercially available products of recycled polycarbonate, R-20 of Lintec Corporation can be cited.

[0077] The relative viscosity of the polycarbonate resin (B) is not particularly limited. From the viewpoints of fluidity and moldability during molding in the resin composition, as well as heat resistance and mechanical properties of the molded product, it is not particularly limited. However, from the viewpoints of heat resistance, mechanical properties, and fluidity, it is preferably 0.3 to 0.8, more preferably 0.3 to 0.7. The inherent viscosity can be determined by measuring with an Ubbelohde viscometer at a temperature of 25 °C using 1,1,2,2-tetrachloroethane as the solvent.

[0078] The mass ratio (A / B) of the polyarylate resin (A) to the polycarbonate resin (B) contained in the resin composition of the present invention needs to be in the range of 99 / 1 to 1 / 99, more preferably 90 / 10 to 10 / 90, further preferably 80 / 20 to 20 / 80, particularly preferably 80 / 20 to 40 / 60, and sufficiently preferably 80 / 20 to 50 / 50. If the proportion of the polyarylate resin (A) relative to the total amount of the polyarylate resin (A) and the polyester resin (B) is too small, the heat resistance of the resin composition is impaired. In addition, if this proportion of the polyarylate resin (A) is too large, the fluidity is impaired.

[0079] The resin composition of the present invention can be produced by mixing a polyarylate resin (A), a polycarbonate resin (B), and other thermoplastic resins and / or various additives as required for imparting characteristic properties, and melt-kneading them. As the kneading method, there are methods using ordinary extruders such as single-screw extruders, twin-screw extruders, roll kneaders, Brabender kneaders, etc. Among them, since the kneading state of various raw materials is good, the method using a twin-screw extruder is preferred. In addition, it is also preferred to use a static mixer and a dynamic mixer in combination. The raw materials can be added separately from a hopper or a side feeder. The resin composition obtained by melt-kneading is preferably formed into pellets. The obtained resin composition contains the resin composition of the present invention and may further contain at least one selected from other thermoplastic resins and additives. At this time, the resin composition may contain or not contain other thermoplastic resins and additives separately.

[0080] Other thermoplastic resins are resin polymers other than the polyarylate resin (A) and the polycarbonate resin (B). As other thermoplastic resins, for example, polyester resins, polyphenylene ether resins, polystyrene resins, acrylonitrile-butadiene-styrene resins, liquid crystal polymers, etc. can be cited. The polyester resin is a polyester resin other than the polyarylate resin (A).

[0081] The content of other thermoplastic resins in the resin composition of the present invention is not particularly limited. For example, it may be 100% by mass or less, particularly 50% by mass or less, based on the total amount of the polyarylate resin (A) and the polycarbonate resin (B). From the viewpoint of further improving the hue and color resistance, it is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less. The lower limit value of the content of other thermoplastic resins is not particularly limited, and the content of the thermoplastic resin may also be 0% by mass.

[0082] As additives, additives that have been conventionally added to the polyarylate resin (A) and the polycarbonate resin (B) can be used. For example, antioxidants, silane compounds, lubricants, dye pigments, fluidity improvers, flame retardants, fillers, etc. can be cited.

[0083] As antioxidants, for example, various antioxidants such as hindered phenol-based, hindered amine-based, thioether-based, and phosphorus-based antioxidants can be cited.

[0084] The silane compound is not particularly limited. As examples of specific trade names, there can be mentioned tetramethoxysilane (TSL8114 manufactured by GE Toshiba Silicones Co., Ltd., KBM-04 manufactured by Shin-Etsu Chemical Co., Ltd.), tetraethoxysilane (TSL8124 manufactured by GE Toshiba Silicones Co., Ltd., KBE-04 manufactured by Shin-Etsu Chemical Co., Ltd.), methyltrimethoxysilane (TSL8113 manufactured by GE Toshiba Silicones Co., Ltd., KBM-13 manufactured by Shin-Etsu Chemical Co., Ltd.), methyltriethoxysilane (TSL8123 manufactured by GE Toshiba Silicones Co., Ltd., KBE-13 manufactured by Shin-Etsu Chemical Co., Ltd.), dimethyldimethoxysilane (TSL8112 manufactured by GE Toshiba Silicones Co., Ltd.), dimethyldiethoxysilane (TSL8122 manufactured by GE Toshiba Silicones Co., Ltd., KBE-22 manufactured by Shin-Etsu Chemical Co., Ltd.), methyldimethoxysilane (TSL8117 manufactured by GE Toshiba Silicones Co., Ltd.), methyldiethoxysilane (TSL8127 manufactured by GE Toshiba Silicones Co., Ltd.), dimethylethoxysilane (TSL8126 manufactured by GE Toshiba Silicones Co., Ltd.), phenyltrimethoxysilane (TSL8173 manufactured by GE Toshiba Silicones Co., Ltd.), phenyltriethoxysilane (TSL8178 manufactured by GE Toshiba Silicones Co., Ltd., KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.), diphenyldimethoxysilane (TSL8172 manufactured by GE Toshiba Silicones Co., Ltd.), diphenyldiethoxysilane (TSL8177 manufactured by GE Toshiba Silicones Co., Ltd.), hexyltrimethoxysilane (KBM-3063 manufactured by Shin-Etsu Chemical Co., Ltd.), decyltrimethoxysilane (KBM-3103C manufactured by Shin-Etsu Chemical Co., Ltd.), 3-glycidoxypropyl dimethoxymethylsilane (TSL-8355 manufactured by GE Toshiba Silicones Co., Ltd.), 3-glycidoxypropyltrimethoxysilane (TSL-8350 manufactured by GE Toshiba Silicones Co., Ltd., KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.), dimethylvinylmethoxysilane (TSL8317 manufactured by GE Toshiba Silicones Co., Ltd.), methylvinyldimethoxysilane (TSL8315 manufactured by GE Toshiba Silicones Co., Ltd.), methylvinyldiethoxysilane (TSL8316 manufactured by GE Toshiba Silicones Co., Ltd.), dimethylvinylethoxysilane (TSL8318 manufactured by GE Toshiba Silicones Co., Ltd.), vinyltrimethoxysilane (KBM-1003 manufactured by Shin-Etsu Chemical Co., Ltd.), vinyltriethoxysilane (TSL8311 manufactured by GE Toshiba Silicones Co., Ltd., KBE-1003 manufactured by Shin-Etsu Chemical Co., Ltd.), 2-(3,4-(Epoxycyclohexyl)ethyltrimethoxysilane (KBM-303 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-glycidoxypropylmethyldiethoxysilane (KBE-402 manufactured by Shin-Etsu Chemical Co., Ltd.), p-styryltrimethoxysilane (KBM-1403 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropylmethyldimethoxysilane (TSL8375 manufactured by GE Toshiba Silicones Co., Ltd., KBM-502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltrimethoxysilane (TSL8370 manufactured by GE Toshiba Silicones Co., Ltd., KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropylmethyldiethoxysilane (KBE-502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltriethoxysilane (KBE-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropyltrimethoxysilane (KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropylmethyldimethoxysilane (KBM-5102 manufactured by Shin-Etsu Chemical Co., Ltd.), diphenyldimethoxysilane (KBM202SS manufactured by Shin-Etsu Chemical Co., Ltd.). Among them, in terms of improving the crystallization rate, a silane compound having 1 functional group selected from acryloxy (or acryloyl), methacryloxy (or methacryloyl), styryl, and vinyl and having 3 alkoxys with 1 to 4 carbon atoms (hereinafter sometimes referred to as silane compound A), and a silane compound having 1 or 2 aryl groups (such as phenyl) and having 3 or 2 alkoxys with 1 to 4 carbon atoms (hereinafter sometimes referred to as silane compound B) are preferably selected, and silane compound B is more preferably selected. As examples of specific trade names of such silane compounds, vinyltrimethoxysilane (KBM-1003 manufactured by Shin-Etsu Chemical Co., Ltd.), vinyltriethoxysilane (TSL8311 manufactured by GE Toshiba Silicones Co., Ltd., KBE-1003 manufactured by Shin-Etsu Chemical Co., Ltd.), p-styryltrimethoxysilane (KBM-1403 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltrimethoxysilane (TSL8370 manufactured by GE Toshiba Silicones Co., Ltd., KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltriethoxysilane (KBE-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropyltrimethoxysilane (KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), diphenyldimethoxysilane (KBM202SS manufactured by Shin-Etsu Chemical Co., Ltd.).,

[0085] As lubricants, for example, fatty acid salts represented by stearates can be cited.

[0086] Examples of the dye pigment include metal complex dyes, anthraquinone dyes, perinone dyes, carbon black, inorganic pigments of inorganic metal series, azo pigments, and organic pigments composed of organic compounds typified by polycyclic pigments.

[0087] Examples of the fluidity improver include inorganic compounds such as fatty acid salts and organic compounds including fluorine-based and amide-based compounds.

[0088] Examples of the flame retardant include various flame retardants of halogen-based, phosphorus-based, nitrogen-based, and hydrated metal-based.

[0089] Examples of the filler include inorganic fillers such as glass fiber, glass beads, mica, talc, and silica (especially spherical silica).

[0090] The finer the average particle diameter of the spherical silica, the less likely it is to impede the function of the product formed from the resin composition when it exfoliates from the resin composition and becomes dust. From the viewpoint of the dimensional stability of the molded article of the resin composition, the average particle diameter is preferably 10 μm or less, more preferably 5 μm or less.

[0091] The average particle diameter of the spherical silica is defined as the particle diameter value at 50% weight cumulative when measuring the particle diameter distribution using a particle size distribution measuring device such as a laser diffraction / scattering particle size analyzer. This measurement is performed, for example, by adding spherical silica to water or alcohol to adjust the suspension to a concentration allowing measurement and dispersing it using an ultrasonic disperser.

[0092] From the viewpoints of further improving the hue and color fastness, as well as improving the mechanical properties, heat and humidity resistance, dimensional stability, and impact resistance, the resin composition of the present invention preferably contains a filler (especially glass fiber and spherical silica) and a silane compound in the above additives and other thermoplastic resins. Specifically, from the viewpoint of further improving the mechanical properties, the resin composition of the present invention preferably contains a filler (especially glass fiber). From the viewpoint of further improving the heat and humidity resistance, the resin composition of the present invention preferably contains a silane compound. From the viewpoints of further improving the dimensional stability and impact resistance, the resin composition of the present invention preferably contains a filler (especially spherical silica).

[0093] The content of the additive in the resin composition is not particularly limited. For example, relative to the total amount of the polyarylate resin (A) and the polycarbonate resin (B), it can be 50% by mass or less, particularly 30% by mass or less. From the viewpoint of further improving the hue and color resistance, it is preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, particularly preferably 1% by mass or less, sufficiently preferably 0.8% by mass or less, more sufficiently preferably 0.4% by mass or less, and most preferably 0% by mass. In the case of containing two or more additives, their total content is within the above range. The lower limit value of the content of the additive is not particularly limited, and the content of the additive can also be 0% by mass.

[0094] When the spherical silica is incorporated into the resin composition of the present invention, a dispersant can be used to disperse the spherical silica in the resin matrix. Specifically, when the resin composition of the present invention contains spherical silica, it can further contain a dispersant. As the dispersant, for example, fatty acid esters and their derivatives, fatty acid amides and their derivatives can be used. As the fatty acid amide, ethylenebis(hydroxystearamide), ethylenebisstearamide, etc. can be cited. By uniformly dispersing the silica in the resin matrix, the molding shrinkage rate and the linear expansion coefficient are reduced, and the dimensional stability is further improved. The addition amount of the dispersant is preferably 0.01 to 0.5 parts by mass relative to 100 parts by mass of the resin composition of the present invention.

[0095] The content of the antioxidant in the resin composition of the present invention is not particularly limited. Even if the resin composition of the present invention does not contain an antioxidant, the hue and color resistance are sufficiently excellent. Therefore, the content of the antioxidant relative to the resin composition of the present invention can be 20% by mass or less, particularly 10% by mass or less. From the viewpoint of further improving the hue and color resistance, it is preferably 5% by mass or less, more preferably 1% by mass or less, further preferably 0.4% by mass or less, particularly preferably 0.2% by mass or less, and sufficiently preferably 0% by mass. In the case of containing two or more antioxidants, their total content is within the above range.

[0096] The resin composition of the present invention contains 0.1 to 2.0 ppm of formate. From the viewpoint of further improving the hue and color resistance, the content of formate is preferably 0.1 to 1.5 ppm, more preferably 0.1 to 0.8 ppm, still more preferably 0.1 to 0.5 ppm, particularly preferably 0.2 to 0.4 ppm, and most preferably 0.2 to 0.25 ppm. In the present invention, by containing an appropriate amount of formate as described above in the resin composition, not only the hue of the resin composition itself can be made sufficiently excellent, but also the color resistance of the molded article of the resin composition can be made sufficiently excellent. When the content of formate in the resin composition exceeds 2 ppm, thermal deterioration during melt molding is promoted, and the yellowing of the resin molded article is significant. On the other hand, if the content of the above formate is less than 0.1 ppm, the a value of the color difference of the resin composition is a very low value, but the inhibitory effect on thermal discoloration during melt molding is not sufficient, and the yellowing of the molded article of the resin composition is significant.

[0097] The formate may be an alkali metal salt of formic acid. For example, sodium formate, potassium formate, etc. can be cited. From the viewpoint of further improving the hue and color resistance, the formate is preferably sodium formate, and the above content is preferably the content of sodium formate.

[0098] The content of formate is determined by the value obtained by extracting formate from 0.5 g of the resin composition with 50 mL of ultrapure water and quantitatively analyzing it by ion chromatography (IC).

[0099] The formate contained in the resin composition may be a residue of formate contained in a reducing agent (such as dithionite (especially sodium dithionite)) used in the production of the polyarylate resin (A), or may also be an additive newly added after the production of the polyarylate resin (A) or during or after the production of the resin composition.

[0100] The content of formate can be controlled by the following method. That is

[0101] · Dissolve and wash the resin composition with a soluble organic solvent. Thereby, the formate content can be reduced. Depending on the resin contained in the resin composition and the monomer components constituting the resin, there are various soluble organic solvents. For example, aliphatic chlorine-based solvents such as dichloromethane, 1,2-dichloroethane, chloroform, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, dibromomethane, tribromomethane, bromoethane, 1,1-dibromoethane, 1-bromopropane, etc., aromatic chlorine-based solvents such as chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, etc., amide-based solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc., ether-based solvents such as 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, etc., aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, etc., and mixtures thereof can be cited. In the above method, polyarylate resin (A) can be used instead of the resin composition for dissolution and washing with a soluble organic solvent.

[0102] · During the production of polyarylate resin (A), adjust the formate content in the dithionite (especially sodium dithionite) used as a reducing agent. For example, if the formate content in the dithionite (especially sodium dithionite) is reduced, the formate content of the resin composition can be reduced. Additionally, for example, if the formate content in the dithionite (especially sodium dithionite) is increased, the formate content of the resin composition can be increased.

[0103] · During the production of polyarylate resin (A), adjust the usage amount of the dithionite (especially sodium dithionite) used as a reducing agent. For example, if the usage amount of the dithionite (especially sodium dithionite) is reduced, the formate content of the resin composition can be reduced. Additionally, for example, if the usage amount of the dithionite (especially sodium dithionite) is increased, the formate content of the resin composition can be increased.

[0104] · During the production of polyarylate resin (A), by strengthening the washing process with pure water (such as extending the washing time, etc.), the formate content of the resin composition can be reduced.

[0105] · During the production of the resin composition, adjust the usage amount of the polyarylate resin. For example, if the usage amount of polyarylate resin (A) is reduced, the formate content of the resin composition can be reduced. Additionally, for example, if the usage amount of polyarylate resin (A) is increased, the formate content of the resin composition can be increased.

[0106] The formate content of the resin composition can be controlled by adopting one or more of the above methods or by combining two or more of them.

[0107] The a value of the color difference of the resin composition of the present invention is generally from -1.0 to 0.5, and from the viewpoint of further improving the hue and color fastness, it is preferably from -1.0 to 0.2, more preferably from -1.0 to -0.1, further preferably from -1.0 to -0.4, and particularly preferably from -0.8 to -0.45.

[0108] The a value of the color difference is a value obtained by filling a measurement container without gaps with a resin composition (for example, the resin composition of the present invention) and measuring it in a reflection mode using a color difference meter (for example, the color difference meter ZE6000 manufactured by Nippon Denshoku Industries Co., Ltd.). The resin composition used for the measurement generally has a granular shape.

[0109] The YI value of a 3 mm thick plate obtained by injection molding the resin composition of the present invention is generally 22 or less, and from the viewpoint of further improving the hue and color fastness, it is preferably 18 or less, more preferably 14 or less, further preferably 10 or less, particularly preferably 9 or less, sufficiently preferably 7 or less, and more sufficiently preferably 6 or less. The lower limit value of the YI value is not particularly limited, and the YI value is generally 1 or more, particularly 4 or more.

[0110] The YI value is a value measured by supplying a 3 mm thick plate obtained by injection molding a resin composition (for example, the resin composition of the present invention) using a usual injection molding machine (for example, the J110AD injection molding machine manufactured by JSW Corporation) at a resin temperature of 280 °C to a color measurement device (for example, the SZ-Σ90 type colorimeter manufactured by Nippon Denshoku Industries Co., Ltd.). The resin composition used for molding generally has a granular shape.

[0111] Examples

[0112] The present invention will be described in detail based on the examples, but the present invention is not limited to these examples, and various modifications and applications can be made without departing from the spirit of the present invention.

[0113] A. Evaluation method

[0114] (1) Quantitative method for sodium formate in sodium dithionite

[0115] Weigh about 0.1 g of sodium dithionite and put it into a PP container, add 20 mL of ultrapure water and let it stand overnight at room temperature to dissolve. Then, dilute the solution 100 times with ultrapure water, filter the diluted solution with a 0.2 μm membrane filter, and perform quantitative analysis using ion chromatography (IC). Quantitative analysis uses the standard curve method (multi-point standard curve).

[0116] (2) Limiting viscosity number of polyarylate resin (A) >

[0117] 1,1,2,2 - tetrachloroethane was used as a solvent to prepare a resin solution at a concentration of 1 g / dl, and the relative viscosity (ηrel) was measured at a temperature of 25°C. The reduced viscosity was calculated from the obtained relative viscosity by the following formula (1).

[0118] ηinh (dl / g) = Ln(ηrel) / c (c: concentration) (Formula (1))

[0119] (3) Quantitative method for residual sodium formate in the resin composition

[0120] Weigh approximately 0.5 g of the freeze - pulverized resin composition and place it in a container made of PP (polypropylene). The shape of the freeze - pulverized resin composition consists of particles with a particle size of 0.3 - 1.5 mm and contains fine powder with a particle size of 0.3 mm or less. It should be noted that the particle size was measured for any 50 particles using a microscope (VH - X6000) manufactured by KEYENCE Corporation. Then, add 50 mL of ultrapure water and perform heating extraction for 1 hour in a dryer set at 120°C. Then, filter using a 0.2 - μm membrane filter and perform quantitative analysis by ion chromatography (IC). Quantitative analysis uses the standard curve method (single - point standard curve), and the amount of formate ions is calculated by the following formula (2), and the amount of sodium formate is converted by the following formula (3).

[0121] Amount of formate ions = A × (B - C) × D ÷ E ÷ F (Formula (2))

[0122] A = Concentration of the calibration standard sample (formic acid)

[0123] B = IC peak area of the sample to be analyzed

[0124] C = IC peak area of the blank

[0125] D = Dilution factor

[0126] E = IC peak area of the calibration standard sample

[0127] F = Weight of the sample to be analyzed

[0128] Amount of sodium formate conversion = G × H ÷ I (Formula (3))

[0129] G = Amount of formate ions

[0130] H = Molecular weight of sodium formate (68.01)

[0131] I = Molecular weight of formate ion (45.02)

[0132] (4) Color difference a value of the resin composition

[0133] Use a color difference meter for color measurement (ZE6000) manufactured by Nippon Denshoku Industries Co., Ltd. Fill the resin composition pellets into the measurement container without gaps, place it on the sample stage, and perform the measurement in reflection mode. Evaluation is carried out according to the following criteria.

[0134] ◎◎: −0.45 or less (excellent);

[0135] ◎: greater than −0.45 and −0.4 or less (good);

[0136] ○: greater than −0.4 and 0.2 or less (good);

[0137] △: greater than 0.2 and 0.5 or less (qualified: no practical problem);

[0138] ×: greater than 0.5 (unqualified: there is a practical problem).

[0139] (5) Yellowness index (YI) value of the injection molded body of the resin composition

[0140] After drying the resin composition pellets at 100 °C for 8 hours, the obtained resin composition is molded into a sample plate (sheet) with a thickness of 3 mm using a conventional injection molding machine (for example, J110AD injection molding machine manufactured by JSW Corporation), and the measurement is carried out using a color tone measuring device (SZ-Σ90 colorimeter manufactured by Nippon Denshoku Industries Co., Ltd.). Evaluation is carried out according to the following criteria.

[0141] ◎◎: 10 or less (excellent);

[0142] ◎: greater than 10 and 14 or less (good);

[0143] ○: greater than 14 and 18 or less (good);

[0144] △: greater than 18 and 22 or less (qualified: no practical problem);

[0145] ×: greater than 22 (unqualified: there is a practical problem).

[0146] B. Raw materials

[0147] <Sodium dithionite used in polyarylate resin (A)>

[0148] Sodium dithionite is manufactured by the following method.

[0149] · Sodium dithionite A (manufacturing method: formate method) (formate content 0.7% by mass) and sodium dithionite B (manufacturing method: formate method) (formate content 0.9% by mass).

[0150] Sodium dithionite is manufactured by the formate method. The amount of formate contained in the manufactured sodium dithionite is quantitatively analyzed by ion chromatography (IC). The content of formate varies slightly in each manufacturing batch. A sample with a content of 0.7% by mass is designated as sodium dithionite A, and a sample with a content of 0.9% by mass is designated as sodium dithionite B.

[0151] · Sodium dithionite C (manufacturing method: formate method): formate content 3.0% by mass (used in Comparative Examples 1 and 2).

[0152] Sodium dithionite C is manufactured by blending commercially available formate into sodium dithionite A (formate content 0.7% by mass) so that the formate content is 3.0% by mass.

[0153] · Sodium dithionite D (manufacturing method: electrolysis method): formate content 0% by mass (used in Comparative Example 5).

[0154] Sodium dithionite D is manufactured by the electrolysis method.

[0155] <Polycarbonate resin (B)>

[0156] · PC (I): (manufactured by Sumika Polycarbonate, 301 - 4, relative viscosity 0.63)

[0157] · PC (II): (manufactured by Sumika Polycarbonate, 301 - 30, relative viscosity 0.43)

[0158] <Glass fiber>

[0159] · Glass fiber: (manufactured by Nippon Electric Glass Co., Ltd., T - 289)

[0160] <Spherical silica>

[0161] · Spherical silica: (manufactured by Denki Kagaku Kogyo Kabushiki Kaisha, FB - 5SDC, average particle size 4.2 μm)

[0162] <Silane compound>

[0163] · Silane compound: (manufactured by Shin-Etsu Chemical Co., Ltd., KBM202SS, compound name is diphenyldimethoxysilane)

[0164] (Example 1)

[0165] · Synthesis method of polyarylate resin powder

[0166] In a reaction vessel equipped with a stirring device, 100 parts by mass of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 3.8 parts by mass of p-tert-butylphenol, 37 parts by mass of sodium hydroxide, 0.6 parts by mass of trimethylbenzylammonium chloride, and sodium dithionite A at 0.5 mass% relative to the mass of the diphenol component were added and dissolved in 1103 parts by mass of water to form an aqueous layer. Separately, 92 parts by mass of a terephthaloyl chloride / isophthaloyl chloride = molar ratio 1 / 1 mixture was dissolved in 895 parts by mass of dichloromethane to form an organic layer. This organic layer was added to the previously prepared aqueous layer under strong stirring, and a polymerization reaction was carried out at 15 °C for 2 hours. Then, after separating the aqueous layer and the organic layer, 10 parts by mass of acetic acid was added to the organic layer to stop the reaction, and it was further repeatedly washed with water until neutral to obtain a 17 mass% dichloromethane solution of polyarylate. The dichloromethane solution of polyarylate was granulated by a warm water granulation method, and the water and dichloromethane components were sufficiently dried using a paddle hot air dryer at 120 to 135 °C to obtain polyarylate resin powder particles. The particle size of these particles was 0.7 to 5.0 mm (in some cases, a part contained fine powder).

[0167] · Resin composition

[0168] The obtained polyarylate resin and polycarbonate resin (I) were pre-mixed at a mass ratio of 50 / 50, and then melt-kneaded and pelletized at 350 °C using a twin-screw extruder with a screw diameter of 37 mm [manufactured by Toshiba Machine Co., Ltd., TEM-37] to obtain the resin composition of the present invention. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0169] (Example 2)

[0170] Sodium dithionite A used in the polyarylate resin at 1.0 mass% relative to the diphenol component was added, and p-tert-butylphenol was 1.6 parts by mass. Except for this, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0171] (Example 3)

[0172] Sodium dithionite B used in the polyarylate resin at 1.2 mass% relative to the diphenol component was added, and p-tert-butylphenol was 1.2 parts by mass. Except for this, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0173] (Example 4)

[0174] Sodium dithionite B used in the polyarylate resin was added in an amount of 3.0% by mass relative to the diphenol component, and p-tert-butylphenol was 0.9 part by mass. Otherwise, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0175] (Example 5)

[0176] Sodium dithionite B used in the polyarylate resin was added in an amount of 4.5% by mass relative to the diphenol component, and p-tert-butylphenol was 0.9 part by mass. Otherwise, the same operations as in Example 1 were carried out to obtain a resin composition. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0177] (Examples 6 to 11 and Comparative Example 6)

[0178] As shown in Table 1, the type of polycarbonate resin, the mixing mass ratio, and the addition of additives were changed. Otherwise, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1. The addition of additives was carried out by simultaneous kneading during the melt-kneading and pelletizing described in Example 1. The addition amount of the additive is the ratio relative to the "total amount of polyarylate resin (A) and polycarbonate resin (B)".

[0179] (Comparative Example 1)

[0180] Sodium dithionite C used in the polyarylate resin was added in an amount of 3.0% by mass relative to the diphenol component. Otherwise, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0181] (Comparative Example 2)

[0182] Sodium dithionite C used in the polyarylate resin was added in an amount of 0.5% by mass relative to the diphenol component. Otherwise, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0183] (Comparative Example 3)

[0184] Sodium dithionite B used in the polyarylate resin was added in an amount of 7.0% by mass relative to the diphenol component. Otherwise, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0185] (Comparative Example 4)

[0186] Sodium dithionite A used in the polyarylate resin in an amount of 0.1% by mass relative to the diphenol component was added, and in addition, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0187] (Comparative Example 5)

[0188] Sodium dithionite D used in the polyarylate resin in an amount of 0.5% by mass relative to the diphenol component was added, and in addition, a resin composition was obtained in the same manner as in Example 1. The respective characteristic values of the obtained resin composition are shown in Table 1.

[0189]

[0190] Based on the above Examples and Comparative Examples, the following matters are shown:

[0191] · By making the amount of sodium formate contained in the resin composition appropriate, the hue of the resin composition becomes good, and the yellowing of the molded article caused by thermal deterioration due to heat melting can be reduced more sufficiently.

[0192] · The resin composition of the present invention can be manufactured by using sodium dithionite having a specific sodium formate content in a specific amount to manufacture a polyarylate resin, and then mixing and kneading a polycarbonate resin.

[0193] · In particular, it can be seen from Comparative Example 5 that even if the hue of the resin composition itself is good, the coloring caused by thermal deterioration during melt molding may not necessarily be suppressed.

[0194] Industrial Applicability

[0195] The resin composition of the present invention is useful in various applications where prevention of yellowing of molded articles is required. As such applications, for example, lens components of digital cameras, disk centering components of optical disk drives, lens components of camera-equipped mobile phones, centering components for recording disks, etc. can be cited.

Claims

1. A resin composition comprising a polyarylate resin A and a polycarbonate resin B, wherein the polyarylate resin A contains an aromatic dicarboxylic acid component and a dihydric phenol component as monomer components, the mass ratio of the polyarylate resin A to the polycarbonate resin B, i.e., A / B, is 99 / 1 to 1 / 99, the content of formate is 0.1 to 2.0 ppm.

2. The polyarylate resin according to claim 1, wherein, The formate is sodium formate.

3. The resin composition according to claim 1, wherein The resin composition has a color difference a value of -1.0 to 0.

5.

4. The resin composition according to claim 1, wherein, A molded plate with a thickness of 3 mm obtained by injection molding the resin composition has a YI value of 22 or less.

5. The resin composition according to claim 1, wherein The content of the formate is 0.1 to 0.8 ppm.

6. A method for manufacturing a resin composition, in which when polymerizing an aromatic dicarboxylic acid component and a dihydric phenol component, a sodium dithionite having a formate content of 0.4 to 1.5% by mass is added at 0.05 to 4.0% by mass relative to the dihydric phenol component to produce the polyarylate resin A, and then, the polycarbonate resin B is further mixed.

7. The method for producing a resin composition according to claim 6, wherein, The sodium dithionite is sodium dithionite produced by the formate method.

8. The method for producing a resin composition according to claim 6, wherein, Manufacturing the resin composition according to any one of claims 1 to 5.

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