JP2009040866A - Polyarylate resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyarylate resin composition which prevents discoloring during molding and is excellent in mechanical properties, and prevents a molded article from being discolored due to heat even if it is used for a long period of time. <P>SOLUTION: The polyarylate resin composition is obtained by blending 0.01-0.5 parts by mass of a phenol compound (b) and 0.01-0.5 parts by mass of a hydrocarbon compound (c) having a specific ring structure containing a phosphorus atom and oxygen atom into 100 parts by mass of a resin composition (a) comprising 10-90 mass% polyarylate resin and 90-10 mass% polycarbonate resin. As this polyarylate resin composition is transparent and excellent in heat resistance and suppressed in discoloration after long term use, the composition can be widely used in the fields of components such as lamp covers or lenses of automobiles, machinery or electrical-electronic equipment. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyarylate resin composition.

  Polyarylate resins comprising dihydric phenols and terephthalic acid and / or isophthalic acid are already well known as engineering plastics.

  Since such polyarylate resin has high heat resistance, excellent mechanical strength and dimensional stability, and is transparent, the molded product is widely applied to fields such as electric / electronic devices, automobiles and machines.

  In recent years, improving the fuel efficiency of automobiles has become the biggest challenge in the automobile industry. For this reason, in order to reduce the weight of materials constituting automobiles, attempts have been actively made to apply low specific gravity plastics to automobile parts instead of high specific gravity metals or other inorganic materials. For example, parts such as lamp covers and lenses mounted on automobiles are no exception, and replacement from glass to plastic is progressing.

  Among these types of parts, acrylic resin is used for parts that have a relatively low requirement for heat distortion, and polycarbonate resin is used for parts that have a somewhat high requirement for heat distortion. However, these acrylic resins and polycarbonate resins do not have sufficient heat resistance for headlamp lenses, inner lenses, or fog lamp lenses, which have higher heat resistance requirements.

  Under these circumstances, applications of polyarylate resin with high heat resistance have been expected for these parts, but polyarylate resin has high load deflection temperature and transparency, but has high melt viscosity and fluidity. However, there is a problem that the moldability is inferior. In order to solve such problems, Patent Document 1 discloses a resin composition comprising a polyarylate resin and a polycarbonate resin.

  On the other hand, when a polyarylate resin or a resin composition of a polyarylate resin and a polycarbonate resin is used for the lamp cover or the like, its application has been greatly limited because the color is remarkably changed by heat caused by the lamp light source. In addition, the polyarylate resin also has a problem that it is thermally deteriorated during heat molding and colored brown.

In order to solve the above problems, Patent Document 2 discloses an ester compound of a phenol compound having two or more phenolic hydroxyl groups and a phosphite compound, and Patent Document 3 discloses a phenol compound or a phosphorus compound. Although addition of lactone compounds to polyarylate is disclosed, further property improvements are needed.
JP 47-22949 A Japanese Examined Patent Publication No. 4-46299 JP 2002-265766 JP

  The problem to be solved by the present invention is to provide a polyarylate resin composition having excellent mechanical properties, which does not cause discoloration during molding processing, has excellent heat resistance, and does not discolor after long-term use. And

  As a result of intensive research to solve such problems, the present inventor has added a small amount of a hindered phenol compound having an alkyl group in the ortho position and a specific cyclic phosphite compound to the polyarylate resin. The inventors have found that discoloration after long-term use, which is the above problem, is suppressed, and have reached the present invention.

That is, the gist of the present invention is as follows.
(A) The phenolic compound (b) 0.01 to 0.5 parts by mass and the following general formula (1) with respect to 100 parts by mass of the resin composition (a) consisting of 10 to 90% by mass of the polyarylate resin and 90 to 10% by mass of the polycarbonate resin A polyarylate resin composition characterized by containing 0.01 to 0.5 parts by mass of a phosphorus compound (c) represented by the formula:

(In the formula, R1 to R10 may be the same or different and are a hydrogen atom or a hydrocarbon group having 10 or less carbon atoms)
(B) Polyarylate resin composition which is (A) which mix | blends 0.01-0.5 mass part of benzofuranone type-compound (d) represented by following General formula (2) with respect to 100 mass parts of resin compositions (a). object.

(Wherein R1 to R5 may be the same or different and are hydrogen atoms or hydrocarbon groups having 10 or less carbon atoms)
(C) Resin composition (a) A polyarylate resin composition in which the ratio of the polyarylate resin in 100 parts by mass of the component is X% by mass at a thickness of 2 mm after being treated in a hot air oven at T ° C for 400 hours. The yellow index (YI ₂ ) is expressed by the following formula {(YI ₂ ) × 100} / {(T-115) × (X)} <0.5
A polyarylate resin composition that satisfies (A).

  The polyarylate resin composition of the present invention hardly undergoes discoloration during molding, has excellent heat aging resistance, does not cause discoloration even when used over a long period of time, and has excellent mechanical properties.

  Hereinafter, the present invention will be described in detail.

  The polyarylate resin used in the present invention is a polyester comprising an aromatic dicarboxylic acid or a derivative thereof and a dihydric phenol or a derivative thereof, and is produced by a method such as solution polymerization, melt polymerization, or interfacial polymerization.

  Preferred examples of the raw material for introducing the aromatic dicarboxylic acid residue 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, methyl terephthalic acid, 4,4'-biphenyldicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 4,4'-diphenylether dicarboxylic acid, 4,4 ' -Diphenylmethane dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 4,4'-diphenylisopropylidenedicarboxylic acid, 1,2-bis (4-carboxyphenoxy) ethane, 5-sodium sulfoisophthalic acid, etc. However, terephthalic acid and isophthalic acid are preferred, and they should be used in combination from the viewpoint of melt processability and mechanical properties. Particularly preferred. In that case, the mixing molar ratio (terephthalic acid / isophthalic acid) is arbitrarily in the range of 100/0 to 0/100, preferably 70/30 to 0/100, more preferably 50/50 to 0/100. is there.

  The raw material for introducing the bisphenol residue is bisphenol. Specific examples thereof include 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4-hydroxy-3,5-dimethylphenyl). ) Propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 4,4'-dihydroxydiphenylsulfone, 4 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl ketone, 4,4′-dihydroxydiphenylmethane, 1,1-bis (4-hydroxyphenyl) cyclohexane and the like. These compounds may be used alone or in combination of two or more. Of these compounds, 2,2-bis (4-hydroxyphenyl) propane is preferably used, and optimally used alone.

  The polyarylate composed of these raw materials is prepared by dissolving 1.0 g of a sample in 100 ml of 1,1,2,2-tetrachloroethane, and preferably having a logarithmic viscosity at 25 ° C. of 0.4 to 1.0, preferably 0.5 to 0.8. Is more preferable. When the logarithmic viscosity is less than 0.4, the molecular weight of the resulting resin composition becomes low, resulting in poor mechanical properties.On the other hand, when the logistic viscosity exceeds 1.0, the melt viscosity becomes high and the color may easily change during melt processing. It is not preferable.

  The polyarylate resin composition of the present invention preferably contains a polycarbonate resin in addition to the polyarylate resin as a resin from the viewpoint of the moldability of the resin composition.

  The polycarbonate resin used in the present invention is a polycarbonate formed by repeating a bisphenol residue unit and a carbonate residue unit. Since the polycarbonate resin has bisphenol residue units similar to those of the polyarylate resin, it exhibits good compatibility with the polyarylate resin.

  Examples of bisphenols as polycarbonate raw materials for introducing bisphenol residue units include 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (3,5-dibromo-4-hydroxyphenyl). Propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) ) Cyclohexane, 1,1-bis (4-hydroxyphenyl) decane, 1,3- or 1,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclododecane, 4, 4'-dihydroxydiphenyl ether, 4,4'-dithiodiphenol, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, 4,4'-dihydroxy-2,5-dihydroxydiphenyl ether, and the like. In addition, diphenols described in US Pat. Nos. 2,999,835, 3,028,365, 3,334,154, and 4,131,575 can be used. These may be used alone or in combination of two or more. Among these compounds, it is preferable to use at least 2,2-bis (4-hydroxyphenyl) propane, more preferably the compound is used alone.

  Examples of the polycarbonate raw material for introducing the carbonate residue unit include phosgene and diphenyl carbonate.

  The polycarbonate resin made of the raw materials as described above desirably has an intrinsic viscosity of 0.4 to 0.8, preferably 0.4 to 0.6, from the viewpoint of mechanical properties and fluidity.

  As such a polycarbonate resin, for example, commercially available Caliber 200-30, 200-13, 200-3 manufactured by Sumitomo Dow can be preferably used.

  The blending ratio of the polyarylate resin and the polycarbonate resin is preferably 10/90 to 90/10 in terms of mass ratio (polyarylate resin / polycarbonate resin) from the viewpoint of molding processability of the resin composition and heat distortion resistance of the molded product. Is 30/70 to 90/10.

  The phenolic compound used in the present invention is a compound containing a hindered phenol moiety having a substituent at the ortho position of the hydroxy group, preferably a compound containing a hindered phenol moiety having a substituent at the ortho position on both sides of the hydroxy group It is. Examples of the substituent at the ortho position include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. it can. When a substituent is present at the ortho position on both sides of the hydroxy group, the two substituents may be the same or different. Preferred is a compound in which both ortho positions on both sides of the hydroxy group are substituted with t-butyl groups.

  Preferred phenol compounds containing a hindered phenol moiety having a substituent at the ortho positions on both sides of the hydroxy group include, for example, propionate hindered phenol compounds, isocyanurate hindered phenol compounds, benzene hindered phenol compounds, and triazine hinders. Examples thereof include dophenol compounds and phosphoric acid hindered phenol compounds.

  Specific examples of propionate-based hindered phenol compounds include, for example, triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate, hexamethylene glycol-bis-2- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2'-thio [diethyl-bis -3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, and the like.

  Specific examples of isocyanurate-based hindered phenol compounds include 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzoyl) isocyanurate, 1,3,5-tris (3,3 And 5-di-t-butyl-4-hydroxybenzoyl) isocyanurate.

  Specific examples of benzene hindered phenol compounds include 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene. it can.

  Specific examples of triazine-based hindered phenol compounds include, for example, 6- (3,5-di-t-butyl-4-hydroxyanilino) -2,4-bisoctyl-thio-1,3,5-triazine. Can be mentioned.

  Specific examples of phosphoric acid-based hindered phenol compounds include 3,5-di-t-butyl-4-hydroxybenzyl phosphoric acid dimethyl ester and bis (3,5-di-t-butyl-4-hydroxybenzyl). (Phosphoric acid) monomethyl ester nickel salt.

  Among the above specific examples, it is preferable to use propionate-based hindered phenol compounds, particularly pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate].

  The content of the phenol compound is 0.01 to 0.5 parts by mass, preferably 0.02 to 0.2 parts by mass, with respect to 100 parts by mass of the total amount of the polyarylate resin and the polycarbonate resin. When the amount is less than 0.01 parts by mass, the effect of preventing discoloration during molding and thermal discoloration during use of the molded product, particularly the effect of preventing discoloration due to heat during long-term use of the molded product becomes poor. On the other hand, if the amount is more than 0.5 parts by mass, the effect reaches saturation and the efficiency is not good. Two or more phenolic compounds may be used in combination, and in that case, the total amount thereof may be within the above range.

  The phosphorus compound used in the present invention is a hydrocarbon compound having a ring structure containing a phosphorus atom and an oxygen atom, preferably having an aromatic ring, more preferably 12H-dibenzo [d, g] [1,3 , 2] A compound represented by the following general formula (1) having dioxaphosphocin as a basic skeleton.

(In the formula, R1 to R10 may be the same or different and are a hydrogen atom or a hydrocarbon group having 10 or less carbon atoms)
Preferred as R1 to R10 in the above formula are hydrogen, methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, cyclohexyl group, octyl group, ethylhexyl group, etc. An aliphatic hydrocarbon group, an aromatic hydrocarbon group such as a phenyl group which is unsubstituted or substituted with an alkyl group, and the like, and R1 to R10 may be the same as or different from each other.

  Specific examples of such compounds include 6-hydroxy-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4,8,10-tetra-tert-butyl-6- Octyloxy-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4,8,10-tetra-tert-butyl-6- (2-ethylhexyl) oxy-12H-dibenzo [ d, g] [1,3,2] dioxaphosphocin, 2,10-dimethyl-4,8-bis (tert-butyl) -6-phenoxy-12H-dibenzo [d, g] [1,3, 2] Dioxaphosphocin, 4,8-dicyclohexyl-6-hydroxy-2,10-dimethyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 4,8-di-tert -Butyl-6-ethoxy-2,10-dimethyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 1,10-dimethyl-4,8-di-tert-butyl-6 -(2,4-Dimethylphenyl) -12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 1,10-dimethyl-4,8-di-tert-butyl-6- (2 , 4-Di-tert-butylphenyl) -12H-dibenzo [d, g] [1,3,2] dioxaphos Hosin etc. are mentioned. In addition, 6,6 '-[1,6-hexanediylbis (oxy)] bis [4,8-bis (1,1-dimethyl) in which two structures of the above formula (3) are bonded by a substituent at the 6-position Ethyl) -2,10-dimethyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin] and 2,4,8,10 having a phosphite structure in the substituent -Tetramethyl-6-[(2,6,7-trioxa-1-phosphabicyclo [2.2.2] octan-4-yl) methoxy] -12H-dibenzo [d, g] [1,3,2] Dioxaphosphocin, 4,8-di-tert-butyl-2,10-dimethyl-6-[(2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane-4-yl) methoxy ] -12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4,8,10-tetra-tert-butyl-6-[(2,6,7-trioxa-1- And phosphabicyclo [2.2.2] octan-4-yl) methoxy] -12H-dibenzo [d, g] [1,3,2] dioxaphosphocin.

  Among these specific examples, 2,4,8,10-tetra-tert-butyl-6-octyloxy-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4 1,8,10-tetra-tert-butyl-6- (2-ethylhexyl) oxy-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin is preferably used.

  The content of the phosphorus compound is 0.01 to 0.5 parts by mass, preferably 0.02 to 0.2 parts by mass, with respect to 100 parts by mass of the total amount of the polyarylate resin and the polycarbonate resin. If the amount is less than 0.01 parts by mass, the effect of preventing discoloration during the molding process of the resin composition and the thermal discoloration during use of the molded product, particularly the effect of preventing discoloration during the molding process of the resin composition will be poor. On the other hand, if the amount is more than 0.5 parts by mass, the effect reaches saturation and the efficiency is not good. Two or more types of phosphorus compounds may be used in combination, and in that case, the total amount thereof may be within the above range.

  The benzofuranone-based compound used in the present invention is not particularly limited as long as it has a benzofuran-2-one skeleton, but 3-arylbenzofuran-2-one having an aryl group at the 3-position of the benzofuran ring Derivatives are more preferred.

  The 3-arylbenzofuran-2-one derivative may have one or more alkyl groups having 1 to 15 carbon atoms at any position, and particularly those having 1 to 4 carbon atoms at positions 5 to 7 of the benzofuranone ring. It preferably has one or more alkyl groups. When two or more substituents are present, they may be the same or different.

  Specific examples of 3-arylbenzofuran-2-one derivatives include, for example, 5,7-di-tert-butyl-3- (2,5-dimethylphenyl) -3H-benzofuran-2-one, 5,7-di -tert-butyl-3- (2,4-dimethylphenyl) -3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2 -One, 5,7-di-tert-butyl-3- (2,3-dimethylphenyl) -3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (4-methylphenyl) -3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (4-ethylphenyl) -3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (4 -Isopropylphenyl) -3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (4-tert-butylphenyl) -3H-benzofuran-2-one, 5,7-di-tert- Butyl-3-phenyl-3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (4-dodecylphenyl) -3H-benzofuran-2-one, 5,7-di-tert- Tyl-3- (2,3,4-trimethylphenyl) -3H-benzofuran-2-one, 5,7-di-tert-butyl-3- (2,3,4,5,6-pentamethylphenyl) A substituted or unsubstituted phenyl group at the 3-position of the benzofuranone ring such as -3H-benzofuran-2-one and 5-methyl-7-tert-butyl-3- (4-methylphenyl) -3H-benzofuran-2-one Substituted at the 3-position of a benzofuranone ring, such as a benzofuran-2-one derivative having the following structure and 5,7-di-tert-butyl-3- (9H-fluoren-3-yl) -3H-benzofuran-2-one And benzofuran-2-one derivatives having an unsubstituted polycyclic aryl group. Among these specific examples, 5,7-di-tert-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one is preferable.

  The content of the benzofuranone-based compound is desirably 0.01 to 0.5 parts by mass, and preferably 0.02 to 0.2 parts by mass with respect to 100 parts by mass of the total amount of the polyarylate resin and the polycarbonate resin. If the amount is less than 0.01 parts by mass, the effect of preventing discoloration due to heat during long-term use of the molded product becomes poor. On the other hand, if the amount is more than 0.5 parts by mass, the effect reaches saturation and the efficiency is not good. Two or more kinds of benzofuranone compounds may be used in combination, and in that case, the total amount thereof may be within the above range.

  The polyarylate resin composition of the present invention is obtained by mixing the above-mentioned predetermined materials. Mixing may be achieved by simply dry blending the materials or by melting and kneading the materials. Among these, it is preferable that the polyarylate resin composition of the present invention is obtained by melt-kneading each component from the viewpoint of handleability when the resin composition is molded.

  The polyarylate resin composition of the present invention can be molded into various molded products by any method. The molding method is not particularly limited, and usually, an injection molding method, an extrusion molding method, a compression molding method, or a solution casting method is preferably used.

The resin composition of the present invention is characterized in that it does not change much color even after being used for a long time at a high temperature. The degree of discoloration due to heat varies depending on the use temperature and the ratio of the polyarylate resin component in the resin composition. The higher the use temperature, the easier the color change of the resin composition. On the other hand, thermal discoloration hardly occurs as the polyarylate resin component increases even at the same use temperature. In the resin composition of the present invention, in order to evaluate the degree of discoloration including the use temperature and the polyarylate ratio in the resin component, a thermal discoloration index represented by the following formula is used.
Thermal discoloration index = {(YI ₂ ) × 100} / {(T-115) × (X)}
(Here, (YI ₂ ) is the yellow index of the molded product having a thickness of 2 mm after heat treatment for 400 hours, T is the temperature of the hot stove, and X is the ratio (mass%) of the polyarylate resin in the resin composition)
The larger the thermal discoloration index, the larger the yellow index after heat treatment, and it is preferably less than 0.5 in the resin composition of the present invention. When the thermal discoloration index is 0.5 or more, the color tone change may not be remarkable when continuously used at high temperatures.

  The intrinsic viscosity of the resin composition of the present invention is preferably 0.4 to 0.7, and more preferably 0.45 to 0.6. If the logarithmic viscosity is less than 0.4, the mechanical properties are inferior. On the other hand, if the logarithmic viscosity exceeds 0.7, the melt viscosity is high and the fluidity during injection molding may be deteriorated.

  In addition to the above components, the polyarylate resin composition of the present invention may contain a hindered amine light stabilizer from the viewpoint of further improving the heat discoloration of the molded product. Further, the resin composition of the present invention contains various additives such as an ultraviolet absorber, a bluing agent, a flame retardant, a mold release agent, an antistatic agent and a lubricant, as long as the heat discoloration of the molded product is not lowered. Also good.

EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited only to these Examples.
1. Raw materials The raw materials used in the examples and comparative examples are as follows.
(A) Polyarylate resin: U-100 manufactured by Unitika (Intrinsic viscosity 0.64). Hereinafter referred to as PAR.
(B) Polycarbonate resin: Caliber 200-30 (extreme viscosity 0.44) manufactured by Sumitomo Dow. Hereinafter, it is assumed to be a PC.
(C) Phenolic compounds: The following two types were used.
(C-1) Pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (AO-60 manufactured by ADEKA). Hereinafter referred to as AO-C1.
(C-2) Octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (AO-50 manufactured by ADEKA). Hereinafter referred to as AO-C2.
(D) Phosphorus compounds: The following two types were used.
(D-1) 2,4,8,10-tetra-tert-butyl-6-octyloxy-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin (HP-10 manufactured by ADEKA) ). Hereinafter referred to as AO-D1.
(D-2) Bis (2,4-di-t-butylphenyl) spiropentaerythritol diphosphite (ADEKA PEP-24G). Hereinafter referred to as AO-D2.
(E) Benzofuranone compound: 5,7-di-tert-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one (HP-136 manufactured by Ciba Specialty Chemicals): Hereinafter referred to as AO-E.
2. Evaluation methods
(1) Intrinsic viscosity: 1,1,2,2-tetrachloroethane was used as a solvent, and the value at a concentration of 25 ° C. was measured.
(2) Tensile strength and tensile elongation: measured according to ISO 527.
(3) Yellow index (YI): The yellow index was measured based on JIS K7103 using a color tone measuring device (SE-2000 type colorimeter manufactured by Nippon Denshoku).

Examples 1-13
Using PAR and PC dried at 120 ° C for 8 hours or more using a hot air circulating dryer, in addition to them, phenol compound AO-C1 or AO-C2, phosphorus compound AO-D1, benzofuranone Compound AO-E mixed at the blending ratio shown in Table 1 is a co-rotating twin-screw extruder with a vent mechanism (Toshiba) using a loss-in-weight continuous quantitative feeder CE-W-1 made by Kubota. TEM-37BS manufactured by Kikai Co., Ltd.). Then, the barrel temperature of the extruder was set to the extrusion temperature shown in Table 1, melt-kneading was performed at a vent vacuum degree of -0.099 MPa (gauge pressure) and a discharge amount of 20 kg / h, and the resin composition taken up in a strand form from the nozzle was obtained. After passing through a water bath, cooling and solidifying, cutting with a pelletizer, and drying with hot air at 120 ° C. for 6 hours, pellets of a resin composition were obtained. Subsequently, the obtained resin composition pellets were molded at a resin temperature of 330 ° C. using an injection molding machine (IS100E-3S manufactured by Toshiba Machine Co., Ltd.) to prepare a tensile property measurement test piece and a sample plate having a thickness of 2 mm. . The tensile property measurement specimens were allowed to stand at room temperature for 1 day or longer and then measured for tensile strength and tensile elongation. Further, as a heat aging test, the sample plate was treated for 400 hours in a hot air oven set to the temperature shown in Table 1, YI before and after the treatment was measured, and the difference (dYI) was calculated as dYI = YI ₂ −YI _1. The thermal discoloration index calculated by the following formula was calculated. Here, YI ₁ is YI before heat treatment, and YI ₂ is YI after heat treatment.
Thermal discoloration index = {(YI ₂ ) × 100} / {(T-115) × (X)}
(Here, (YI ₂ ) is the yellow index of the molded product having a thickness of 2 mm after heat treatment for 400 hours, T is the temperature of the hot stove, and X is the ratio (mass%) of the polyarylate resin in the resin composition)

Comparative Examples 1-5
Resin composition pellets were prepared and evaluated in the same manner as in the Examples except that the compounding and extrusion temperatures shown in Table 2 were used. The results are shown in Table 2.

In Examples, a resin composition having a good initial color tone and heat discoloration resistance at each PAR / PC blending ratio is obtained, and in particular, the one containing a benzofuranone compound is more excellent. On the other hand, in Comparative Examples 1 to 3, since the phosphorus compounds different from those in Examples were used, the initial color tone and the heat discoloration were inferior. Further, in Comparative Example 4, the amount of phenolic compound is small, so the heat discoloration is inferior, and in Comparative Example 5, the amount of phosphorus compound is small, the initial color tone and heat discoloration are inferior. became

Claims (3)

For 100 parts by mass of the resin composition (a) comprising 10 to 90% by mass of the polyarylate resin and 90 to 10% by mass of the polycarbonate resin, 0.01 to 0.5 parts by mass of the phenolic compound (b) and the following general formula (1) A polyarylate resin composition comprising 0.01 to 0.5 parts by mass of a phosphorus compound (c) to be prepared.

(In the formula, R1 to R10 may be the same or different and are a hydrogen atom or a hydrocarbon group having 10 or less carbon atoms) 2. The polybenzoic acid compound according to claim 1, wherein 0.01 to 0.5 parts by mass of the benzofuranone compound (d) represented by the following general formula (2) is blended with respect to 100 parts by mass of the resin composition (a). Arylate resin composition.

(Wherein R1 to R5 may be the same or different and are hydrogen atoms or hydrocarbon groups having 10 or less carbon atoms) The yellow index (YI ₂ ) at a thickness of 2 mm after treating a polyarylate resin composition in which the ratio of the polyarylate resin in the resin composition (a) is X mass% in a hot air oven at T ° C. for 400 hours is The following formula {(YI ₂ ) × 100} / {(T-115) × (X)} <0.5
2. The polyarylate resin composition according to claim 1, wherein: