JP6303707B2 - Aromatic polycarbonate resin composition and molded article thereof - Google Patents

Description

  The present invention relates to an aromatic polycarbonate resin composition and a molded article thereof. Specifically, the present invention relates to an aromatic polycarbonate resin composition in which the problem of yellowing when exposed to heating conditions for a long time is improved, and a molded article formed by molding the aromatic polycarbonate resin composition.

  In recent years, in Europe, North America, etc., daylighting of automobiles has been promoted to improve visibility from daytime pedestrians and oncoming vehicles by installing daylights that are always lit on the headlamps and rear lamps of automobiles. . The daylight generally includes a light guide member and a light source that causes light to enter the light guide member. An incandescent lamp such as a halogen lamp is generally provided near the daylight of an automobile as a normal light source for nighttime. Therefore, the light guide member is an incandescent lamp in addition to the heat generated from the daylight light source. It is also heated by the heat generated from. For this reason, the heat-resistant durability is calculated | required by the light guide member.

Conventionally, as a constituent material of a light guide member, for example, Patent Document 1 below discloses an aromatic polycarbonate resin composition in which a phosphorus stabilizer and a fatty acid ester are blended with an aromatic polycarbonate resin.
Further, as an improvement in the hue and anti-yellowing property of the aromatic polycarbonate resin composition of Patent Document 1, Patent Document 2 discloses two types of phosphite-based stabilizers as phosphorus stabilizers to be blended with the aromatic polycarbonate resin. An aromatic polycarbonate resin composition using an agent is disclosed.

  That is, when a light guide member used in an automotive lighting device is molded using an aromatic polycarbonate resin composition, the aromatic polycarbonate resin deteriorates due to heat received in the molding process, and the resulting molded product has a slightly yellowish color. May be tinged. Moreover, even if it does not become yellowish at the time of shaping | molding, as above-mentioned, a light guide member will deteriorate and yellow by being exposed to the heat of the light source around a light guide member for a long time. The aromatic polycarbonate resin composition of Patent Document 2 improves the hue of the aromatic polycarbonate resin composition of Patent Document 1 and suppresses this yellowing.

One of the two types of phosphite stabilizers used in Patent Document 2 is a phosphite stabilizer having a spiro ring skeleton, and the other is one having no spiro ring skeleton.
The phosphite stabilizer having a spiro ring skeleton used in Patent Document 2 is represented by the following general formula (1).

(In Formula (1), R ¹ and R ² each independently represents an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms.)

  Patent Document 2 includes a phenyl group and a naphthyl group as the aryl group having 6 to 30 carbon atoms in the general formula (1). Specific examples in this case include bis (2,4- Although di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, and phenylbisphenol A pentaerythritol diphosphite are mentioned. There is no exemplification of the phosphite stabilizer (BI) used in the present invention, and this phosphite stabilizer (BI) has a remarkable effect of suppressing yellowing when exposed to heating conditions for a long time. There is no description suggesting improvement.

JP 2007-204737 A JP 2013-234233 A

  If it is an aromatic polycarbonate resin composition of patent document 2, compared with the aromatic polycarbonate resin composition of patent document 1, a hue is improved and yellowing is also suppressed, but it is exposed to heating conditions for a long time. Further improvement is desired in the yellowing suppression effect in the case of the above. That is, as described above, for example, a light guide member of an automobile lighting device is exposed to a high temperature condition for a long time due to heat from a daylight light source or an incandescent lamp. In the light guide member application of such an automobile lighting device, for example, even when exposed to a long time of 1000 hours under a high temperature condition of 120 ° C., it is required that the problem of yellowing is small. The aromatic polycarbonate resin composition of Patent Document 2 does not sufficiently satisfy such high yellowing resistance. That is, in Patent Document 2, ΔYI according to the present invention, which will be described later, is acceptable, and only one example of ΔYI of 18.0 is described, but ΔYI of other examples is about 23 to 33. It has become.

  The present invention further improves the yellowing resistance compared to the aromatic polycarbonate resin composition of Patent Document 2, and the aromatic polycarbonate resin composition has less yellowing problems even when exposed to heating conditions for a long time. And it aims at providing the molded article formed by shape | molding this aromatic polycarbonate resin composition.

  In order to solve the above-mentioned problems, the present inventor has conducted extensive research on phosphorus-based stabilizers to be blended with aromatic polycarbonate resins, and as a result, has found that specific phosphite-based stabilizers can solve the above-mentioned problems.

  The present invention has been achieved based on such findings, and the gist thereof is as follows.

[1] A phosphite stabilizer represented by the following general formula (I) as a phosphorus stabilizer (B) with respect to 100 parts by mass of the aromatic polycarbonate resin (A) and the aromatic polycarbonate resin (A) ( B-I) 0.01 to 0.1 part by mass and 0.01 to 0.5 part by mass of a phosphite stabilizer (B-II) represented by the following general formula (II), and fatty acid ester (C) 0.03-0.3 parts by mass, and the content ratio of the phosphite stabilizer ( BI ) and the phosphite stabilizer (B-II) is a mass ratio, and the phosphite stabilizer (B-II) / phosphite based stabilizer (B-I) = 1.5~8 aromatic polycarbonate resin composition characterized scope der Rukoto of.

（式（II）中、Ｒ ^２１ 〜Ｒ ^２５ は、それぞれ独立に、水素原子、炭素数６〜２０のアリール基、又は炭素数１〜２０のアルキル基を表す。） (In Formula (I), R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ^{19 to} R ²² each independently represents an alkyl group, an aryl group, or an aralkyl group, d represents an integer of 0 to 3 independently.)

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)

[2] The aromatic polycarbonate resin composition according to [1], wherein the aromatic polycarbonate resin (A) has a viscosity average molecular weight of 10,000 to 22,000.

[3] [1] or Oite in [2], wherein the phosphite stabilizer (B-I) is an aromatic polycarbonate resin composition which is a compound represented by the following structural formula (Ia) .

[4] In any one of [1] to [3], the total content of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is the aromatic polycarbonate resin ( A) An aromatic polycarbonate resin composition that is 0.3 parts by mass or less with respect to 100 parts by mass.
[ 5 ] In any one of [1] to [ 4 ], a 300 mm long YI value (YI ₀ ) measured for a 300 mm long optical path molded product obtained by injection molding using the aromatic polycarbonate resin composition. And 300 mm long YI value (YI _X ) measured after the 300 mm long optical path molded product was subjected to heat aging treatment at 120 ° C. for 1000 hours, ΔYI calculated by the following formula is 20 or less, Aromatic polycarbonate resin composition.
ΔYI = YI _X −YI ₀

[ 6 ] A molded product formed by molding the aromatic polycarbonate resin composition according to any one of [1] to [ 5 ].

[ 7 ] The molded product according to [ 6 ], which is a light guide member.

[ 8 ] The molded product according to [ 7 ], wherein the molded product is a light guide member built in an automobile lighting device.

A molded product formed by molding the aromatic polycarbonate resin composition of the present invention is sufficiently suppressed in yellowing even when exposed to heating conditions for a long time.
For this reason, when the light guide member of the automotive lighting device is molded using the aromatic polycarbonate resin composition of the present invention, a light guide member having excellent heat resistance and durability can be provided. The light transmission efficiency can be maintained high for a long time, and the replacement frequency of the light guide member can be greatly reduced.

  Hereinafter, embodiments of the present invention will be described in detail.

[Aromatic polycarbonate resin composition]
The aromatic polycarbonate resin composition of the present invention comprises a specific phosphite stabilizer (P) as a phosphorus stabilizer (B) with respect to 100 parts by mass of the aromatic polycarbonate resin (A) and the aromatic polycarbonate resin (A). BI) 0.01-0.1 mass part and fatty acid ester (C) 0.03-0.3 mass part are contained, It is characterized by the above-mentioned.

  In the following, the hue immediately after molding of a molded product obtained by molding the aromatic polycarbonate resin composition is referred to as “initial hue”, and yellowing when the obtained molded product is exposed to heating conditions for a long time is referred to as “initial hue”. The suppressing effect is referred to as “heat-resistant yellowing suppressing effect”.

<Aromatic polycarbonate resin (A)>
The aromatic polycarbonate resin (A) is an aromatic polycarbonate polymer obtained by reacting an aromatic hydroxy compound with a diester of phosgene or carbonic acid. The aromatic polycarbonate polymer may have a branch. The method for producing the aromatic polycarbonate resin is not particularly limited, and may be a conventional method such as a phosgene method (interfacial polymerization method) or a melting method (transesterification method).

  Typical examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, and 2,2-bis (4-hydroxy-3-methylphenyl). ) Propane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy) -3,5-dibromophenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxybiphenyl, 3,3 ', 5 , 5′-tetramethyl-4,4′-dihydroxybiphenyl, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) Le) sulfide, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) ketone.

Among the aromatic dihydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is particularly preferable.
The aromatic dihydroxy compounds may be used alone or in combination of two or more.

  When the aromatic polycarbonate resin (A) is produced, a small amount of polyhydric phenol having 3 or more hydroxy groups in the molecule may be added in addition to the aromatic dihydroxy compound. In this case, the aromatic polycarbonate resin (A) has a branch.

  Examples of the polyhydric phenol having three or more hydroxy groups include phloroglucin, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene-2, 4,6-dimethyl-2,4. , 6-tris (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene-3, 1,3,5-tris (4-hydroxyphenyl) benzene, Polyhydroxy compounds such as 1,1,1-tris (4-hydroxyphenyl) ethane, or 3,3-bis (4-hydroxyaryl) oxindole (= isatin bisphenol), 5-chlorouisatin, 5,7-dichloroisatin , 5-bromoisatin and the like. Among these, 1,1,1-tris (4-hydroxylphenyl) ethane or 1,3,5-tris (4-hydroxyphenyl) benzene is preferable. The amount of the polyhydric phenol used is preferably an amount of 0.01 to 10 mol%, more preferably 0.1 to 2 mol%, based on the aromatic dihydroxy compound (100 mol%). It is.

  In the polymerization by the transesterification method, a carbonic acid diester is used as a monomer instead of phosgene. Representative examples of the carbonic acid diester include substituted diaryl carbonates typified by diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates typified by dimethyl carbonate, diethyl carbonate, di-tert-butyl carbonate and the like. These carbonic acid diesters can be used alone or in combination of two or more. Among these, diphenyl carbonate and substituted diphenyl carbonate are preferable.

  The carbonic acid diester may preferably be substituted with dicarboxylic acid or dicarboxylic acid ester in an amount of 50 mol% or less, more preferably 30 mol% or less. Representative dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, and diphenyl isophthalate. When a part of the carbonic acid diester is substituted with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

  When an aromatic polycarbonate resin is produced by a transesterification method, a catalyst is usually used. Although there is no restriction | limiting in a catalyst seed | species, Generally basic compounds, such as an alkali metal compound, an alkaline-earth metal compound, a basic boron compound, a basic phosphorus compound, a basic ammonium compound, an amine compound, are used. Of these, alkali metal compounds and / or alkaline earth metal compounds are particularly preferred. These may be used alone or in combination of two or more. In the transesterification method, the catalyst is generally deactivated with p-toluenesulfonic acid ester or the like.

  The aromatic polycarbonate resin (A) can be copolymerized with a polymer or oligomer having a siloxane structure for the purpose of imparting flame retardancy and the like.

The viscosity average molecular weight of the aromatic polycarbonate resin (A) is preferably 10,000 to 22,000. When the viscosity average molecular weight of the aromatic polycarbonate resin (A) is less than 10,000, the molded product obtained may have insufficient mechanical strength, and it may not be possible to obtain a product having sufficient mechanical strength. Moreover, when the viscosity average molecular weight of aromatic polycarbonate resin (A) exceeds 22,000, since the melt viscosity of aromatic polycarbonate resin (A) becomes large, for example, an aromatic polycarbonate resin composition is obtained by a method such as injection molding. As a result, it is not possible to obtain excellent fluidity when producing a long molded product such as a light guide member by molding, and the amount of heat generated by shearing of the resin increases, resulting in deterioration of the resin due to thermal decomposition. In some cases, a molded product having an excellent hue cannot be obtained.
The viscosity average molecular weight of the aromatic polycarbonate resin (A) is more preferably 12,000 to 18,000, and further preferably 14,000 to 17,000.

  Here, the viscosity average molecular weight is calculated from the solution viscosity measured at a temperature of 20 ° C. using methylene chloride as a solvent.

  The aromatic polycarbonate resin (A) may be a mixture of two or more kinds of aromatic polycarbonate resins having different viscosity average molecular weights, or a mixture of aromatic polycarbonate resins having a viscosity average molecular weight outside the above range. It may be within the range of the viscosity average molecular weight.

<Phosphorus stabilizer (B)>
The aromatic polycarbonate resin composition of the present invention contains a phosphite stabilizer (BI) represented by the following general formula (I) as the phosphorus stabilizer (B).

(In Formula (I), R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ^{19 to} R ²² each independently represents an alkyl group, an aryl group, or an aralkyl group, d represents an integer of 0 to 3 independently.)

In the general formula (I), R ^{11 to} R ¹⁸ are each independently preferably an alkyl group having 1 to 5 carbon atoms, preferably a methyl group, and a to d are 0. Preferably there is.
The phosphite stabilizer (BI) used in the present invention is preferably bis (2,4-dicumylphenyl) pentaerythritol diphosphite represented by the following structural formula (Ia).

  The said phosphite type stabilizer (BI) may be used individually by 1 type, or may use 2 or more types together.

  In the aromatic polycarbonate resin composition of the present invention, the content of the phosphite stabilizer (BI) is 0.01 to 0.1 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). is there. When the content of the phosphite stabilizer (BI) is less than 0.01 parts by mass, a sufficient heat-resistant yellowing prevention effect cannot be obtained, and the initial hue tends to be inferior. If the content of the phosphite stabilizer (BI) exceeds 0.1 parts by mass, the amount of gas at the time of molding increases and transfer defects due to mold deposits occur. There is a risk that the rate will decrease. The content of the phosphite stabilizer (BI) is preferably 0.015 to 0.08 parts by mass, more preferably 0.02 to 0.08 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). 06 parts by mass.

  In the aromatic polycarbonate resin composition of the present invention, the phosphorous stabilizer (B) and the phosphite stabilizer (BI) together with the phosphite stabilizer represented by the following general formula (II) ( It is preferable to use B-II) together in order to further improve the initial hue and further enhance the heat yellowing suppression effect.

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)

In the general formula (II), examples of the alkyl group represented by R ^{21 to} R ²⁵ include a methyl group, an ethyl group, a propyl group, an n-propyl group, an n-butyl group, a tert-butyl group, and a hexyl group. And an octyl group.

  As the phosphite stabilizer (B-II) used in the present invention, (tris (2,4-di-tert-butylphenyl) phosphite represented by the following structural formula (IIa) is particularly preferable.

  The above phosphite stabilizers (B-II) may be used alone or in combination of two or more.

  In the aromatic polycarbonate resin composition of the present invention, the content of the phosphite stabilizer (B-II) is 0.01 to 0.5 parts by mass, particularly 100 parts by mass of the aromatic polycarbonate resin (A). 0.03-0.3 parts by mass, especially 0.05-0.2 parts by mass, and the phosphite stabilizer (B-II) / phosphite stabilizer (B It is preferable that the mass ratio of -I) is 1 to 10, particularly 1.5 to 8, particularly 1.8 to 6. When the content of the phosphite stabilizer (B-II) is less than the above range, the effect of suppressing the initial hue and heat yellowing suppression effect by using the phosphite stabilizer (B-II) is sufficient. Even if the amount is larger than the above range, no further improvement in the effect is observed, and the content of the entire phosphorus-based stabilizer (B) increases, resulting in an increase in gas during molding. This is not preferable because transfer defects due to mold deposits may occur.

  In the aromatic polycarbonate resin composition of the present invention, when the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) are used in combination as the phosphorus stabilizer (B), the total content thereof Is preferably 0.3 parts by mass or less and more preferably 0.2 parts by mass or less with respect to 100 parts by mass of the aromatic polycarbonate resin (A).

<Fatty acid ester (C)>
The fatty acid ester (C) is a condensation compound of an aliphatic carboxylic acid and an alcohol.

  Examples of the aliphatic carboxylic acid constituting the fatty acid ester (C) include saturated or unsaturated aliphatic monocarboxylic acid, dicarboxylic acid, and tricarboxylic acid. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. As the aliphatic carboxylic acid, a monocarboxylic acid or dicarboxylic acid having 6 to 36 carbon atoms is preferable, and an aliphatic saturated monocarboxylic acid having 6 to 36 carbon atoms is more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, melicic acid, tetratriacontanoic acid. , Montanic acid, glutaric acid, adipic acid and azelaic acid.

  On the other hand, examples of the alcohol include saturated or unsaturated monohydric alcohols and polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom, a chlorine atom, a bromine atom or an aryl group. Among these alcohols, monovalent or polyvalent saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols or polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic alcohol also includes an alicyclic alcohol.

  Examples of the alcohol include octanol, decanol, dodecanol, tetradecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaol. Examples include erythritol.

  Examples of the fatty acid ester (C) include beeswax (mixture containing myristyl palmitate as a main component), hydrogenated oil, butyl stearate, behenyl behenate, octyldodecyl behenate, stearyl stearate, glycerin monopalmitate, glycerin. Examples include monostearate, glycerol monosoleate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, etc. It is done.

  Of these, fatty acid monoglycerides such as glycerin monopalmitate and glycerin monostearate are preferably used. In this case, when the aromatic polycarbonate resin composition is produced, the friction between the barrel and screw surface in the extruder and the resin can be reduced, and the temperature rise of the polycarbonate resin during processing can be prevented. The hue is particularly excellent and yellowing can be suppressed to a higher degree.

  The fatty acid ester (C) may be used alone or in combination of two or more.

  In the aromatic polycarbonate resin composition of the present invention, the content of the fatty acid ester (C) is 0.03 to 0.3 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). When content of fatty acid ester (C) is less than 0.03 mass part, there exists a tendency for the initial stage hue and / or heat-resistant yellowing inhibitory effect of the molded article obtained to be not enough. On the other hand, when the content of the fatty acid ester (C) exceeds 0.3 parts by mass, the initial hue of the obtained molded product tends to be inferior. The content of the fatty acid ester (C) is preferably 0.06 to 0.3 parts by mass, more preferably 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). is there.

<Other ingredients>
The aromatic polycarbonate resin composition of the present invention includes, as optional components, an antioxidant, a mold release agent, an ultraviolet absorber, a fluorescent whitening agent, a dye / pigment, a flame retardant, an anti-resistance, as long as the object of the present invention is not impaired. Impact modifiers, antistatic agents, lubricants, plasticizers, compatibilizers, fillers, and the like may be blended.

<Method for producing aromatic polycarbonate resin composition>
The method for producing the aromatic polycarbonate resin composition of the present invention is not particularly limited, and for example, at any stage until the final molded product is molded, the components are mixed together or divided and melt-kneaded. A method is mentioned. As a blending method of each component, for example, a method using a tumbler, a Henschel mixer or the like, a method of quantitatively feeding to an extruder hopper with a feeder and mixing, and the like can be mentioned. Examples of the melt kneading method include a method using a single screw kneading extruder, a twin screw kneading extruder, a kneader, a Banbury mixer, and the like.

[Molding]
The molded article of the present invention is formed by molding the above-described aromatic polycarbonate resin composition of the present invention.

  Although there is no restriction | limiting in particular in the shaping | molding method of the aromatic polycarbonate resin composition of this invention, For example, an injection molding method, a compression molding method, an injection compression molding method etc. are mentioned, Preferably it is an injection molding method.

Incidentally, suppressing the thermal degradation of the resin during molding, in order to obtain excellent in initial color, when forming the aromatic polycarbonate resin composition of the present invention, in an inert gas atmosphere such as nitrogen It is preferable to perform molding.

  The molded product of the present invention formed by molding the aromatic polycarbonate resin composition of the present invention has an excellent initial hue, and the degree of yellowing when exposed to heating conditions for a long time compared to conventional products. Since it is very few, it is suitably used as a light guide member of a lighting device, particularly a light guide member of an automotive lighting device that is exposed not only to a light source of a daylight but also to heat generated by an incandescent lamp. The light transmission efficiency of the light guide member can be maintained high over a long period of time due to the excellent initial hue and heat yellowing suppression effect, and the replacement frequency of the light guide member can be greatly reduced.

[ΔYI]
Since the aromatic polycarbonate resin composition of the present invention is excellent in heat-resistant yellowing suppression effect, it is injection-molded using the aromatic polycarbonate resin composition of the present invention according to the method described in the Examples section below. The 300 mm long YI value (YI ₀ ) measured for the 300 mm long optical path molded product obtained by this, and the 300 mm long YI value (YI) measured after the 300 mm long optical path molded product was subjected to thermal aging treatment at 120 ° C. for 1000 hours. since the _X), .DELTA.YI calculated by the following formula, usually 20 or less, preferably 16 or less, more preferably it is 13 or less, even when exposed to heating conditions, to suppress over a decrease in the hue-term Can do.
ΔYI = YI _X −YI ₀

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

The materials used in Examples , Reference Examples and Comparative Examples are as follows.

<Aromatic polycarbonate resin (A)>
"Iupilon (registered trademark) H-4000N" manufactured by Mitsubishi Engineering Plastics Co., Ltd .: Bisphenol A type aromatic polycarbonate resin produced by interfacial polymerization (viscosity average molecular weight 16,000)

<Phosphorus stabilizer (B)>
<Phosphite stabilizer (BI)>
"Doverphos S-9228" manufactured by Properties & Characteristics: bis (2,4-dicumylphenyl) pentaerythritol diphosphite
<Phosphite stabilizer (B-II)>
“ADEKA STAB AS2112” manufactured by ADEKA: Tris (2,4-di-tert-butylphenyl) phosphite
<Other phosphorus heat stabilizers>
“ADEKA STAB PEP-36” manufactured by ADEKA: bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite

<Fatty acid ester (C)>
"Rikemar S-100A" manufactured by Riken Vitamin Co., Ltd .: Stearic acid monoglyceride

<Release agent>
“SH556” manufactured by Toray Dow Corning Silicone Co., Ltd .: methylphenylpolysiloxane

[ Reference Examples 1 to 3, Examples 4 to 6 and Comparative Examples 1 and 2]
<Production of aromatic polycarbonate resin composition>
The components shown in Table 1 were blended so as to have the ratio shown in Table 1, and were uniformly mixed with a tumbler mixer to obtain a mixture. This mixture is supplied to a single screw extruder (“VS-40” manufactured by Isuzu Chemical Industries Ltd.) equipped with a full flight screw and a vent, and the screw rotation speed is 80 rpm, the discharge rate is 20 kg / hour, and the barrel temperature is 250 ° C. Kneaded and extruded in a strand form from the tip of the extrusion nozzle. The extrudate was quenched in a water bath and cut and pelletized using a pelletizer to obtain pellets of an aromatic polycarbonate resin composition.

<Characteristic evaluation>
About the aromatic polycarbonate resin composition obtained by making it above, the initial hue and the heat-resistant yellowing suppression effect were investigated as follows.
(1) Initial hue The hue was measured as follows using the YI value as an index.
After drying the pellets of the aromatic polycarbonate resin composition at 120 ° C. for 4 to 8 hours with a hot-air circulating dryer, 300 mm long optical path molding is performed at a temperature of 280 ° C. with an injection molding machine (“EC100” manufactured by Toshiba Machine Co., Ltd.). A product (6 mm × 4 mm × 300 mm, L / d = 50) was obtained. About this molded article, 300 mm length YI value was measured using the long optical path spectral transmission color meter ("ASA1" by Nippon Denshoku Industries Co., Ltd.). Let this YI value be the initial hue “YI ₀ ”. The results are shown in Table 1.

(2) Heat-resistant yellowing suppression effect The yellowing suppression effect was measured as follows using ΔYI value, which is the amount of change in YI value due to thermal aging, as an index.
The molded product after the initial hue measurement in the above (1) was put into a hot air circulating dryer set at 120 ° C. and subjected to a heat aging treatment for 1000 hours. Thereafter, the YI value after the heat aging treatment was measured in the same manner as in the above (1) initial hue. With this YI value as “YI _X ”, ΔYI was determined from the following equation. The results are shown in Table 1.
ΔYI = YI _X −YI ₀

Table 1 shows the following points.
Comparative Example 1 uses a phosphite stabilizer PEP-36 having a spiro skeleton used in Patent Document 2 and a release agent, and has a high initial hue and a long ΔYI of 38.7. The degree of yellowing when exposed to time heating conditions is very large.
In Comparative Example 2, a phosphite stabilizer PEP-36 having a spiro skeleton used as a first phosphite stabilizer and another phosphite stabilizer used as a second phosphite stabilizer in Patent Document 2 are used. The phytic stabilizer AS2112 is used in combination, and the initial hue and heat yellowing suppression effect are improved as compared with Comparative Example 1, but it is not sufficient, and in particular, ΔYI is very large at 24.8.

In contrast, in Reference Examples 1 to 3 and Examples 4 to 6 using the phosphite stabilizer S-9228 which is the phosphite stabilizer (BI) according to the present invention, ΔYI is 16 in all cases. The following excellent heat-resistant yellowing suppression effects are obtained.
In Reference Example 1, since the amount of phosphite stabilizer S-9228 is small, the initial hue is slightly inferior. By increasing the amount of phosphite stabilizer S-9228, Reference Example 2 is used. , 3, the initial hue is also improved.
In Examples 4 to 6 in which the phosphite stabilizer AS2112 which is the phosphite stabilizer (B-II) is used in combination, the initial hue and ΔYI are very excellent.
As mentioned above, it turns out that the aromatic polycarbonate resin composition of this invention is excellent in the heat-resistant yellowing suppression effect and also the initial stage hue.

Claims (8)

For 100 parts by mass of the aromatic polycarbonate resin (A) and the aromatic polycarbonate resin (A),
0.01-0.1 part by mass of a phosphite stabilizer (BI) represented by the following general formula (I) as the phosphorus stabilizer (B) and a phosphite represented by the following general formula (II) 0.01 to 0.5 parts by mass of a system stabilizer (B-II) ,
Fatty acid ester (C) 0.03-0.3 parts by mass ,
The content ratio of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is, by mass ratio, phosphite stabilizer (B-II) / phosphite stabilizer (B- the aromatic polycarbonate resin composition characterized scope der Rukoto of I) = 1.5 to 8.

(In Formula (I), R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ^{19 to} R ²² each independently represents an alkyl group, an aryl group, or an aralkyl group, d represents an integer of 0 to 3 independently.)

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)   2. The aromatic polycarbonate resin composition according to claim 1, wherein the aromatic polycarbonate resin (A) has a viscosity average molecular weight of 10,000 to 22,000. The aromatic polycarbonate resin composition according to claim 1 or 2 , wherein the phosphite stabilizer (BI) is a compound represented by the following structural formula (Ia).

4. The aromatic polycarbonate resin (A) 100 according to any one of claims 1 to 3, wherein the total content of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is 100%. An aromatic polycarbonate resin composition characterized by being 0.3 parts by mass or less with respect to parts by mass. The YI value (YI ₀ ) of 300 mm length measured on a 300 mm long optical path molded product obtained by injection molding using the aromatic polycarbonate resin composition according to any one of claims 1 to 4 , Aromatic characterized in that ΔYI calculated by the following formula is 20 or less from 300 mm long YI value (YI _X ) measured after heat aging treatment at 120 ° C. for 1000 hours for a 300 mm long optical path molded product Polycarbonate resin composition.
ΔYI = YI _X −YI ₀ A molded article formed by molding the aromatic polycarbonate resin composition according to any one of claims 1 to 5 . The molded product according to claim 6, wherein the molded product is a light guide member. 8. The molded product according to claim 7, wherein the molded product is a light guide member built in an automobile lighting device.