JPH06179805A - Production of polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate resin composition which can be processed at a relatively low temp. while maintaining the fluidity of the polycarbonate, by incorporating a specific p-terphenyl derivative and/or a specific p- quaterphenyl derivative into the polycarbonate, melt-kneading the mixture, and cooling the resulting melt under specific conditions. CONSTITUTION:A mixture comprising 100 pts.wt. polycarbonate and 0.5-15 pts.wt. at least one compound selected from p-terphenyl derivatives represented by formulae I to III and p-quaterphenyl derivatives represented by formulae IV to VI is melt-kneaded at 240-340 deg.C and then cooled to 200 deg.C at a rate of 5-50 deg.C/min. In the formulae, R<1> and R<2> each is-H, -CH2CH2OH, -CH2CH2OCOCH3, -CH2CH(CH3)OH, -CH2CH(CH3)OCOCH3, a 1-15C alkyl, or -COR<3> (wherein R<3> is a 1-15C alkyl).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polycarbonate resin composition. More specifically, it relates to a method for producing a polycarbonate resin composition that enables injection molding at a low heating cylinder temperature of 200 to 280 ° C.

[0002]

2. Description of the Related Art Polycarbonate, one type of engineering plastic, has a glass transition temperature of 140 to 1
It has a high temperature of 50 ° C and is excellent in mechanical properties, dimensional stability, transparency and water absorption resistance. Therefore, polycarbonate is
Mechanical parts that require high performance in strength and heat resistance,
It is used for electrical parts and optical parts.

However, such a polycarbonate has poor meltability due to its high melt viscosity, and has the drawback that it must be molded at a high temperature of 260 to 300 ° C. further,
When using polycarbonate as a resin for mechanical parts or electrical parts, glass fiber is added to improve the mechanical properties of parts, but this makes the flowability of polycarbonate worse. Therefore, it becomes necessary to perform molding at a high temperature of 300 to 360 ° C. On the other hand, when polycarbonate is heated to 350 ° C. or higher, there is a problem that the coloration of the obtained molded product becomes severe.

In order to improve the fluidity of the above-mentioned polycarbonate during processing, the following methods have been conventionally proposed, for example. JP-A-63-90556 and JP-A-63-90557 disclose a method of mixing a styrene-based copolymer with a polycarbonate, and JP-A-63-90555 discloses a polycarbonate with a polylactone and a styrene-based copolymer. A method of mixing with a polymer is disclosed. Further, JP-A-61-123625 and JP-A-63-43925 propose a method of adding a phenol having a specific aliphatic chain as a molecular weight modifier when producing a polycarbonate resin. Has been done. However, in these methods, although the flowability of the polycarbonate is improved to some extent, there is a problem in that the excellent heat resistance and mechanical strength originally possessed by the polycarbonate are greatly reduced.

Further, Japanese Patent Publication No. 58-13586 proposes a method of adding an aromatic carboxylic acid ester to a polycarbonate, and Japanese Patent Publication No. 60-34584 proposes a method of adding an organic carbonate to the polycarbonate. There is. However, such compounds, which act as plasticizers and processing aids on polycarbonates,
It is unstable at a high temperature of 0 to 300 ° C. and may decompose at the above-mentioned molding temperature.

[0006]

As described above, in the conventional method for producing a polycarbonate resin composition,
There is a problem that the coloring of the molded product becomes intense when processing is carried out at a high temperature that can maintain the fluidity of the polycarbonate, while on the other hand, when processing is performed by adding another compound that imparts fluidity to the polycarbonate, There is a problem that the heat resistance and mechanical strength originally possessed by polycarbonate are greatly reduced.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for producing a polycarbonate resin composition which can be processed at a relatively low temperature while maintaining the fluidity of the polycarbonate. To do.

[0008]

The method for producing a polycarbonate resin composition of the present invention is characterized by the following formulas (I) to (III) per 100 parts by weight of polycarbonate.
-Terphenyl derivatives and the following general formulas (IV) to (VI)
After melt-kneading a polycarbonate mixture containing 0.5 to 15 parts by weight of at least one selected from the group consisting of p-quaterphenyl derivatives represented by the following at 240 to 340 ° C., 5 to 50 ° C. up to 200 ° C. / The temperature is decreased at a temperature decrease rate of a minute, whereby the above object is achieved.

[0009]

[Chemical 2]

(However, in the above general formula, R ¹ and R ² are independently -H, -CH ₂ CH ₂ OH, -CH ₂ CH _{2
OCOCH 3, -CH 2 CH (CH} 3) OH, -CH 2 CH
(CH ₃₎ OCOCH _3, alkyl group, or -COR ³ carbon atoms is 1 to 15 (R ³ is an alkyl group having 1 to 15 carbon atoms) represents a).

The polycarbonate used in the present invention is
Those having a repeating unit represented by the following formula (VII) as a main constituent unit are particularly preferable.

[0012]

[Chemical 3]

Examples of the above-mentioned polycarbonate include Iupilon (registered trademark, manufactured by Mitsubishi Gas Chemical Co., Inc.), Panlite (registered trademark, manufactured by Teijin Kasei), Novarex (registered trademark,
Mitsubishi Kasei), Lexan (registered trademark, manufactured by GE), Markron (registered trademark, manufactured by Mobay), Macrolon (registered trademark, manufactured by Bayer). In addition, in the present invention, in addition to the repeating unit represented by the above formula (VII) as a main constituent unit, a polycarbonate having another repeating unit as a main constituent unit is also applicable.

The p-terphenyl derivative and / or p-quaterphenyl derivative used in the present invention is a compound represented by the above general formula (I) to (III) or (IV) to (VI). In the above general formula, the alkyl group may or may not be branched. For example, as the p-quarterphenyl derivative represented by the above general formula (V), 4,4 ′ ″-dihydroxy-p-quarterphenyl, 4,
4 '''-dimethoxy-p-quarterphenyl,4,4'''-diacetoxy-p-quarterphenyl and the like can be mentioned. Four,
4 '''-dihydroxy-p-quarterphenyl is in the Journal
Method of Chemical Society, 1379-85 (1940), 4
-Hydroxy-4'-bromobiphenyl in the presence of alkali,
It can be produced by a method in which a palladium catalyst is heated and pressed to react to synthesize a dimer, and then acid precipitation is performed.

The p-terphenyl derivative and / or the p-quaterphenyl derivative are mixed in a proportion of 0.1 to 15 parts by weight with respect to 100 parts by weight of the polycarbonate. If the mixing ratio is less than 0.1 parts by weight, the melt viscosity of the polycarbonate is hardly reduced and molding at low temperature is impossible, which is not preferable. On the other hand, if the mixing ratio exceeds 15 parts by weight, the effect of decreasing the melt viscosity of the polycarbonate does not increase, and the heat resistance and mechanical properties of the polycarbonate only decrease, which is not preferable. Preferably the mixing ratio is 0.5
To 12 parts by weight, particularly preferably 0.7 to 1
0 parts by weight. The above p-terphenyl derivative and /
Alternatively, the p-quaterphenyl derivative may be used alone or in combination of two or more kinds.

In the method for producing a polycarbonate resin composition of the present invention, the polycarbonate and the p-terphenyl derivative and / or the p-quaterphenyl derivative are melt-kneaded, and then the temperature is lowered to 200 ° C. at a constant cooling rate. Is.

First, the melt-kneading of the polycarbonate and the p-terphenyl derivative and / or the p-quaterphenyl derivative can be carried out by an extruder, a kneader or a Banbury mixer. The kneading temperature at this time is in the range of 240 to 340 ° C. Kneading temperature is 240
If the temperature is lower than 0 ° C, the mixture of the polycarbonate and the p-terphenyl derivative and / or the p-quaterphenyl derivative is not sufficiently melted, and if the kneading temperature is higher than 340 ° C, the mixture is colored. Sometimes. Generally, the kneading time is preferably 3 to 10 minutes.

Next, the above-mentioned melt-kneaded kneaded product is added to 20
In order to lower the temperature to 0 ° C., it is artificially performed at a temperature lowering rate of 5 to 50 ° C./min. If the cooling rate is less than 5 ° C / min, the cooling effect is not so large and the cooling is only time-consuming, which is not practical, and if the cooling rate exceeds 50 ° C / min, the The melt viscosity of the obtained polycarbonate mixture does not decrease sufficiently. Preferably, the cooling rate is 1
It is in the range of 0 to 20 ° C./minute.

As a method for lowering the temperature of the kneaded product, for example, a method of passing the kneaded product through a thermostatic chamber in which the temperature is sequentially set low, a method of applying hot air whose temperature is controlled, 100
The method of holding in a constant temperature bath of up to 150 ° C. may be mentioned. After the temperature is lowered to 200 ° C., it may be rapidly cooled by immersing it in a cooling water tank or may be gradually cooled by keeping it at room temperature.

The method for producing a polycarbonate resin composition of the present invention can be applied to a polycarbonate resin composition to which reinforcing fibers are added within the range of not impairing the practicality in order to improve heat resistance and mechanical properties. it can. Generally, the reinforcing fiber is preferably added in a ratio of 5 to 200 parts by weight with respect to 100 parts by weight of the polycarbonate.
Examples of the reinforcing fiber include glass fiber, carbon fiber, boron fiber and the like. Further, if necessary, stabilizers, flame retardants, antistatic agents, release agents, pigments and the like can be added to the polycarbonate resin composition as long as practicality is not impaired.

[0021]

EXAMPLES The present invention will be described below based on Examples and Comparative Examples.

(Examples 1 and 2, Comparative Examples 1 to 3) Polycarbonate (Tanjin Kasei Co., Ltd., Panlite K-1300) 1
After mixing 100 parts by weight of dilauroxy-p-quaterphenyl (DLQ) by weight shown in Table 1, this mixture was supplied to a 40 mm single extruder (L / D = 28) and melt-kneaded at 300 ° C. . The melted and kneaded product coming out of the mold was successively passed through a constant temperature bath whose temperature was set low to cool it to 200 ° C. The cooling rate at this time is shown in Table 1. Then, it was rapidly cooled in a cooling water tank, cut with a cutter, and pelletized. A JIS K7127 tensile test No. 1 test piece was injection-molded using the pellets at a mold temperature of 70 ° C.

With respect to the obtained polycarbonate resin composition, melt viscosity, tensile modulus and heat distortion temperature were measured by the following methods. Regarding the melt viscosity, the melt viscosity at a heating cylinder temperature of 230 ° C was measured as an index for determining whether or not the polycarbonate resin composition can be injection-molded in a heating cylinder temperature range of 200 to 280 ° C. The results of these measurements are shown in Table 1.

Melt Viscosity By using a high flow tester, measurement was performed three times in accordance with JIS 7210 (flow test method-reference test), and the average value was taken as the measured value. Measuring condition is 1m diameter of plunger
m, die length 10 mm, load 100 kg, heating temperature 2
It was set to 30 ° C. Tensile Modulus According to ASTM D648, it was measured by pulling the test piece at a speed of 25 mm / min.

Heat distortion temperature According to ASTM D 648, 18.6 kg / cm ²
The load was measured.

[0026]

[Table 1]

(Examples 3, 4 and Comparative Examples 4, 5) Polycarbonate (Panlite K-1300 manufactured by Teijin Chemicals Ltd.) 1
The polycarbonate resin composition was pelletized in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 3 except that dilauroxy-p-quaterphenyl (DLQ) was mixed in the amount of 100 parts by weight shown in Table 2. Got Then, the melt viscosity, the tensile modulus, and the heat distortion temperature were measured in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 3 above. The measurement results are shown in Table 2.

[0028]

[Table 2]

(Examples 5 to 9) Dilauroxy-p-quarterphenyl (DLQ) was added to 100 parts by weight of polycarbonate (Panlite K-1300 manufactured by Teijin Chemicals Ltd.).
Instead of p-terphenyl (T) in Example 5, 4-butoxy-p-terphenyl (BT) in Example 6, and 4,4 ″ ′-dioctoxy-p-terphenyl (in Example 7). DO
T), p-quaterphenyl (Q) in Example 8 and 4-butoxy-p-quaterphenyl (BQ) in Example 9 were mixed in an amount of 5 parts by weight, respectively, except for the above Examples 1 and 2 and Comparative Example 1. Pelletizing was carried out in the same manner as ~ 3 to obtain a polycarbonate resin composition. Then, in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 3, melt viscosity, tensile modulus,
The heat distortion temperature was measured. The measurement results are shown in Table 3.

[0030]

[Table 3]

[0031]

As is apparent from the above description, according to the present invention, a polycarbonate resin having fluidity at a relatively low temperature without adding a plasticizer or a processing aid for imparting fluidity to the polycarbonate. Since the composition can be obtained, injection molding at a relatively low heating cylinder temperature of 200 to 280 ° C. is possible. This can be said to be very advantageous because the lower the heating cylinder temperature is, the lower the molding cost is, and the resulting molded body is not colored. The molded article of the polycarbonate resin composition obtained in the present invention does not significantly deteriorate in heat resistance and mechanical strength, and thus can be applied to various machine parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Daishiro Kishimoto 2-24-23 Mishimaoka, Ibaraki-shi, Osaka Sunhits Mishimaoka 306

Claims (1)

[Claims] 1. A p-terphenyl derivative represented by the following general formulas (I) to (III) and a general formula (IV) to (VI) below relative to 100 parts by weight of polycarbonate.
A polycarbonate mixture containing 0.5 to 15 parts by weight of at least one selected from the group consisting of p-quaterphenyl derivatives is melt-kneaded at 240 to 340 ° C., and then cooled to 200 ° C. at 5 to 50 ° C./min. A method for producing a polycarbonate resin composition, which comprises lowering the temperature at a speed. [Chemical 1] (However, in the general formula, R ¹ and R ² are each independently —H, —CH ₂ CH ₂ OH, or —CH ₂ CH ₂ OCOC.
_{H 3, -CH 2 CH (CH} 3) OH, -CH 2 CH (C
H ₃₎ OCOCH _3, alkyl group, or -COR ³ carbon atoms is 1 to 15 (R ³ represents an alkyl group) having 1 to 15 carbon atoms).