JP2001310935A - Aromatic polycarbonate resin composition and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aromatic polycarbonate resin composition diminishing development of clear foreign matters when passing through a polymer filter, and excellent in clarity and an appearance of the molded product. SOLUTION: The polyrcarbonate resin composition obtained by interfacial polymerization is characterized as the account of clear foreign matters with a diameter of 10 μm and above contained is 5 parts/g and below. The temperature of a melted composition passing through a polymer filter is to be 280 to 340 deg.C, in the molded that the aromatic polycarbonate resin obtained by interfacial polymerization of an aromatic dihydroxy compound and a carbonate derivative is melted and kneaded, with additives and then passed through the polymer filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a process for melting and kneading an aromatic polycarbonate resin and an additive obtained by the interfacial polymerization of an aromatic dihydroxy compound and a carbonate compound, and forming a transparent foreign matter produced when passing through a polymer filter. An object of the present invention is to provide an aromatic polycarbonate resin composition having a small amount, excellent transparency and appearance of a molded article, and having few errors when used as an optical information recording medium, and having excellent quality.

[0002]

2. Description of the Related Art Polycarbonate resins have excellent mechanical properties such as impact resistance, and are also excellent in heat resistance and transparency, and are widely used in various machine parts, optical discs, automobile parts and the like. ing. In particular, there are great expectations for optical applications such as optical disks for memories, optical fibers, and lenses, and various studies have been actively conducted. In such optical applications, the appearance of polycarbonates having a low content of impurities and foreign substances is particularly desired for optical information recording media.

[0003] Additives are added to an aromatic polycarbonate resin obtained by interfacial polymerization of an aromatic dihydroxy compound and phosgene, and the mixture is melt-kneaded with an extruder or the like. (See, for example, JP-A-5-239334).

However, the present inventors have studied and found that
After passing through the polymer filter, it was found that transparent foreign substances of 10 μm or more were often generated in the resin. Also,
As for this transparent foreign matter, it was found that when the aromatic dihydroxy compound passes through the filter at a high temperature, the aromatic dihydroxy compound is generated with some interaction with the material of the filter. .

[0005] Further, if this transparent foreign matter occurs frequently,
In particular, it has been found that not only does the appearance of the optical information recording medium such as a CD-R or DVD be poor, but also the function of the product such as a recording error is affected.

[0006]

SUMMARY OF THE INVENTION The present invention reduces the generation of transparent foreign matters when melt-kneading an aromatic polycarbonate resin and an additive obtained by the interfacial polymerization of an aromatic dihydroxy compound and a carbonate compound, thereby reducing the occurrence of transparent foreign matters. An object of the present invention is to provide an aromatic polycarbonate resin composition having excellent properties and molded appearance.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to prevent the generation and mixing of transparent foreign matter which lowers the transparency, causes molding defects, and induces recording errors. The present inventors have found that by controlling the temperature at which the kneaded aromatic polycarbonate resin composition passes through a polymer filter within a specific temperature range, it is possible to prevent the generation and mixing of transparent foreign matter, thereby completing the present invention.

That is, a first gist of the present invention is characterized in that the number of transparent foreign substances having a size of 10 μm or more present in an aromatic polycarbonate resin composition obtained by an interfacial polymerization method is 5 / g or less. Aromatic polycarbonate resin composition. Further, a second gist of the present invention is to melt knead an aromatic polycarbonate resin and an additive obtained by interfacial polymerization of an aromatic dihydroxy compound and a carbonate compound, and then pass through a polymer filter. The temperature of the melt-kneaded product to be produced is controlled at 280 to 340 ° C., which is a method for producing an aromatic polycarbonate resin composition.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In preparing the aromatic polycarbonate resin used in the present invention, an aromatic dihydroxy compound and a carbonate compound are used as raw materials. Aromatic dihydroxy compound: The aromatic dihydroxy compound is represented by the following formula (1).

[0010]

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(Wherein B is a divalent hydrocarbon group having 1 to 15 carbon atoms, a halogen-substituted divalent hydrocarbon group,
-S- group, -SO ₂ - group, -SO- group, -O- group, or -
X represents a CO- group, and X represents a halogen atom, having 1 to 14 carbon atoms.
Alkyl group, aryl group having 6 to 18 carbon atoms, 1 carbon atom
Oxyalkyl group or oxyaryl group having 6 to 18 carbon atoms. m is 0 or 1, y is 0 to 4
Is an integer. A plurality of Xs and two y's may be the same or different. )

As the aromatic dihydroxy compound represented by the formula (1), for example, 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A], 2,2-
Bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3,5-diphenyl) ) Phenyl) propane, 2,
2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxyphenyl) pentane, 2,4′-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis ( 4-hydroxy-5-nitrophenyl) methane, 1,
1-bis (4-hydroxyphenyl) ethane, 3,3-
Bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4′-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, 4,4'-dihydroxy-
Examples thereof include 2,5-diethoxydiphenyl ether. Among these, bisphenol A is preferred. These aromatic dihydroxy compounds can be used alone or in combination of two or more.

Carbonate compound: The carbonate compound is represented by the following formula (2).

[0014]

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(Wherein, R is a halogen atom, having 1 to 1 carbon atoms)
14 represents an alkoxy group or an aryloxy group having 6 to 18 carbon atoms. Two Rs may be the same or different. ) Examples of the carbonate compound represented by the formula (2) include phosgene gas and diphenyl carbonate. In particular, phosgene is frequently used in the interfacial polymerization method.

Interfacial polymerization: The reaction ratio of the above-mentioned two raw materials, the aromatic dihydroxy compound and the carbonate compound, is usually 1.02 to 2.0 by the molar ratio of carbonate compound / aromatic dihydroxy compound in consideration of yield and reaction efficiency. 1.30,
More preferably, it is selected from the range of 1.10 to 1.20. When the molar ratio is less than this range, the amount of the aromatic dihydroxy compound present in the obtained aromatic polycarbonate resin increases, and when the molar ratio exceeds this range, the color tone of the polycarbonate resin is deteriorated, and neither is preferable.

In a specific embodiment of the preparation of an aromatic polycarbonate resin by interfacial polymerization, first, an aromatic dihydroxy compound is converted to an aqueous alkali solution, and an interfacial polymerization reaction is performed with a carbonate compound in the presence of an amine compound catalyst. An aromatic polycarbonate resin is obtained through a process of washing, washing and drying. In the interfacial polymerization reaction using phosgene as a carbonate compound (phosgene method), the reaction is usually performed in the presence of an acid binder and a solvent. As the acid binder, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, pyridine and the like are used. As the solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. Further, a catalyst such as a tertiary amine or a quaternary ammonium salt may be used for the reaction accelerator, and phenol, p-ter may be used as the molecular weight regulator.
It is desirable to use a terminal terminator such as t-butylphenol, p-cumylphenol, and isooctylphenol. It is preferable that the reaction temperature is generally 0 to 40 ° C., the reaction time is several minutes to 5 hours, and the pH during the reaction is generally maintained at 10 or more.

The amount of the aromatic dihydroxy compound present in the aromatic polycarbonate resin obtained by the interfacial polymerization is preferably 50 ppm or less, more preferably 20 ppm or less, based on the weight of the resin. . Since this amount depends on the amount of the raw material aromatic dihydroxy compound remaining unreacted during the interfacial polymerization, the reduction is mainly attributable to the reaction conditions such as the above-described reaction ratio between the aromatic dihydroxy compound and the carbonate compound. Perform by adjustment. When this amount is 50 ppm or more, the mixture is melt-kneaded through an extruder, and when passing through a polymer filter under a high temperature, the residual aromatic hydroxy compound rapidly changes into a transparent foreign substance.

Resin composition: The obtained aromatic polycarbonate resin is melt-kneaded with various additives such as a heat stabilizer, a release agent, a coloring agent such as a dye and a pigment, a light stabilizer, and the like.
Immediately, the mixture is passed through a polymer filter and pelletized to obtain a resin composition.

The apparatus used for melt-kneading in the present invention is not particularly limited, and a single-screw or twin-screw extruder is usually used, but a rotor-type kneader or a Banbury-type mixer may be used. The resin temperature at the outlet of the melt-kneading apparatus is preferably from 280 ° C to 340 ° C, and more preferably from 290 ° C to 330 ° C.

The polymer filter used in the present invention comprises:
Generally, it consists of a housing, a center post and a number of leaf disks. The number of leaf disks, which are filter elements mounted on the center post, ranges from several to several hundred, depending on the flow rate and viscosity of the polymer. For mounting on the center post, for example, a predetermined number of leaf disks having a circular hole in the center are passed through a cylindrical center post having a large number of small through holes on the surface, and the disks are sufficiently tightened. Will be The assembly of the polymer filter is performed by fixing the center post, on which the leaf disk is mounted as described above, at a predetermined position in the housing. In this type of polymer filter, the supplied polymer melt is filtered through a leaf disk, passes through the center post through hole, passes through the space in the cylinder, and is discharged from one end opening of the center post. Having a structure. The material of the center post and the housing is usually SUS
And inner plating.

The leaf disk for a polymer filter used in the present invention is usually disk-shaped and has a diameter of 100 to 600.
One or more layers of woven wire mesh having a thickness of about 5 mm and a thickness of about 5 mm and having various wire diameters and opening ratios are used. The type of weaving includes plain weave, twill weave, plain tatami weave, twill tatami weave, and the like, and nonwoven fabric may be used. The material is usually SUS-3
A stainless steel such as 16 or SUS-316L is used, but a sintered metal or a resin can also be used. The leaf disk also has an absolute filtration accuracy of preferably 0.5
μm to 50 μm, more preferably 1.0 μm to
It is 30 μm, particularly preferably 7 μm to 20 μm. The use of a leaf disk having such an absolute filtration accuracy is preferable because the residence time of filtration is not increased and the polycarbonate composition is not thermally degraded, and the leaf disk can be used for a long life. If a filter with a smaller absolute filtration accuracy is selected, the filtration resistance of the filter will increase, and the temperature of the resin passing through the filter will rise due to shear heat generation and the temperature may fall outside the predetermined temperature range. Therefore, when selecting the filtration accuracy of the filter, it is important to consider the measures to prevent the rise in temperature by designing in consideration of the throughput and the filtration area.

In the method of the present invention, the temperature of the molten resin passing through the polymer filter is usually from 280 ° C to 340 ° C.
° C, preferably 290 ° C to 330 ° C. That is,
When the temperature of the molten resin exceeds this temperature range, even if the amount of the aromatic dihydroxy compound present in the aromatic polycarbonate is as small as 50 ppm or less, the generation amount of the transparent foreign matter rapidly increases, and the amount of the transparent foreign matter increases in the disk. As a cause of the occurrence of molded silver, problems such as recording errors and poor appearance occur. Further, when the temperature falls below this temperature range, the pressure increases and the filtration efficiency of the filter decreases, which hinders operation and is not realistic. In the case where there are a plurality of leaf disks, if the resistance of the filter is large, the temperature may gradually increase from the melt kneading apparatus outlet temperature. Therefore, in the present invention, the temperature passing through the polymer filter refers to the maximum temperature during passing through the filter.

When the polymer filter is used, it is necessary to raise the temperature to the above-mentioned temperature before passing the polymer melt. In addition, the gas used when raising the temperature of the polymer filter, particularly the leaf disk mounted on the center post, is preferably an inert gas, particularly preferably argon or nitrogen. Further, the flow rate of the inert gas used at the time of raising the temperature is not particularly limited. In order to avoid this, it is usually preferable to flow an inert gas heated to 100 ° C. to 300 ° C. at a flow rate of 10 ml / min or less to shorten the time for raising the temperature of the polymer filter.

As described above, by optimizing the temperature of the molten resin passing through the polymer filter and the amount of the residual aromatic dihydroxy compound in the polycarbonate resin, 10 μm is obtained.
An aromatic polycarbonate resin having an amount of transparent foreign matters having a size of m or more per 5 g of polycarbonate can be obtained. When the number of these transparent foreign substances exceeds 5, the generation rate of silver at the time of molding increases, and as a result,
Problems such as recording errors and poor appearance occur.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples unless it exceeds the gist thereof. The analysis of the aromatic polycarbonate resin composition obtained in the following examples was performed by the following measurement method.

(1) Viscosity average molecular weight (Mv) The intrinsic viscosity [η] at 20 ° C. in methylene chloride was measured using an Ubbelohde viscometer, and the viscosity average molecular weight (Mv) was determined from the following equation. [Η] = 1.23 × 10 ⁻⁴ × (Mv) ^0.83

(2) Number of Transparent Foreign Particles
After drying at ℃ for 6 hours or more, a single shaft 3 made by Isuzu Kako Co., Ltd.
Using a 0 mm extruder, a film having a thickness of 70 μm is formed, and a 90 cm × 50 cm area (about 4 g) is marked with a nucleus-free transparent foreign substance (= fish eye) using a stereoscopic microscope, and is enlarged at a magnification of 200 times. And the number were measured. The planar boundary of the transparent foreign substance without a nucleus is determined by the difference in the refractive index from the periphery, and the size is defined as the maximum distance between portions having different refractive indexes. The number of transparent foreign substances having a size of 10 μm or more, which is equal to or greater than the absolute filtration accuracy of the polymer filter used, was counted, and the number of foreign substances per 1 g was calculated.

(3) Appearance of Molded Product The polycarbonate resin composition was cured under a nitrogen atmosphere for 120 minutes.
After drying at ℃ for 6 hours or more, S manufactured by Sumitomo Heavy Industries, Ltd.
A CD-R disc was molded at a temperature of 320 ° C. using a D-40 mold. Al was vapor-deposited on the surface of the molded product by using Al sputter manufactured by Raybolt Co., Ltd., and the appearance was visually inspected to observe the generation of silver. Here, silver is a general term for linear defects formed during molding.

(4) Determination of Bisphenol A (BPA) in Aromatic Polycarbonate Resin 1 g of polycarbonate resin was precisely weighed and dissolved in 30 ml of methylene chloride solvent, and 10 ml of 0.02N sodium hydroxide solution was added thereto. Mix on a shaker for minutes. The solution was transferred to a separation flask, the aqueous layer was separated, and measured using a liquid chromatograph (LC-10AD, manufactured by Shimadzu Corporation).

Example 1 Bisphenol A as an aromatic dihydroxy compound
(1) is converted to phosgene (2) as a carbonate compound.
Was obtained by an interfacial polymerization method at a molar ratio of (2) / (1) = 1.17 (viscosity average molecular weight of 1550).
0, BPA content 20 ppm), triphenyl phosphite (Adeka Stab M-329, manufactured by Asahi Denka Kogyo KK) as a heat stabilizer, 100 ppm, and glycerin fatty acid ester (Riken Vitamin KK, Riquemar S-
100A) 300 ppm mixed, twin screw extruder (Tex 30HSS, L / D, manufactured by Nippon Steel Works, Ltd.)
= 27) and melt-kneaded at 280 ° C.
SU whose absolute filtration accuracy is 10 μm
The mixture was passed through a polymer filter equipped with an S-316L leaf disk and pelletized. About this pellet,
Table 1 shows the results of evaluating the number of transparent foreign matters and the appearance of the molded product.

Example 2 A polycarbonate resin was prepared in exactly the same manner as in Example 1 except that a polymer filter provided with a SUS-316L leaf disk having a temperature of 320 ° C. to 340 ° C. and having an absolute filtration accuracy of 5 μm was used. A pellet was obtained. The evaluation results are shown in Table 1.

Comparative Example 1 A polycarbonate resin pellet was obtained in exactly the same manner as in Example 1, except that the temperature of the polymer filter was changed to 350 ° C. The evaluation results are shown in Table 1.

Comparative Examples 2 and 3 Bisphenol A as an aromatic dihydroxy compound
(1) is converted to phosgene (2) as a carbonate compound.
Were adjusted by a molar ratio of (2) / (1) = 1.02 or less to obtain two kinds of polycarbonate resins obtained by the interfacial polymerization method (Comparative Example 2: viscosity average molecular weight of 15300, BPA amount of 300 pp
m; Comparative Example 3: viscosity average molecular weight of 15,400, BPA amount of 1
00 ppm) and the temperature of the polymer filter is 3
A polycarbonate resin pellet was obtained in exactly the same manner as in Example 1, except that the temperature was changed to 50 ° C. The evaluation results are shown in Table 1.

[0035]

[Table 1]

As shown in Examples 1 and 2 in Table 1 above,
According to the present invention, by setting the temperature at the time of passing through a polymer filter to a specific range, it is possible to prevent mixing of a transparent foreign substance into a product, and to obtain an aromatic polycarbonate resin composition having excellent transparency and moldability. I understand.

[0037]

According to the present invention, the transparency of the aromatic polycarbonate resin composition is reduced, and molding defects are caused.
It is possible to prevent the generation and mixing of a transparent foreign substance that causes a recording error.

Continued on the front page (72) Inventor Kazumasa Morita 1-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu City, Fukuoka Prefecture Inside the Kurosaki Office of Mitsubishi Chemical Corporation (72) Inventor Masahiro Yoshizumi 1-1, Kurosaki Castle Stone, Yawata Nishi-ku, Kitakyushu City, Fukuoka Mitsubishi F-term (reference) at Kurosaki Office of Chemical Co., Ltd. KD01 KE11 KH05 LB05 5D029 KA07 KA19

Claims (4)

[Claims] 1. An aromatic polycarbonate resin composition characterized in that the number of transparent foreign substances having a size of 10 μm or more present in the aromatic polycarbonate resin composition obtained by the interfacial polymerization method is 5 / g or less. 2. The amount of the aromatic dihydroxy compound present in the aromatic polycarbonate resin is based on the weight of the resin.
The aromatic polycarbonate resin composition according to claim 1, wherein the content is 50 ppm or less. 3. A method in which an aromatic polycarbonate resin obtained by interfacial polymerization of an aromatic dihydroxy compound and a carbonate compound is melt-kneaded with an additive and then passed through a polymer filter. Is 280 to 340 ° C., the method for producing an aromatic polycarbonate resin composition. 4. An optical information recording medium obtained by molding the aromatic polycarbonate resin composition according to claim 1 or 2 or the aromatic polycarbonate resin composition obtained by the method according to claim 3.