JP2708660B2 - Method for producing polycarbonate resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polycarbonate resin. More specifically, the present invention relates to a method for producing a polycarbonate resin showing a plurality of polymer peaks according to a molecular weight distribution chart by the GPC method.

[0002]

2. Description of the Related Art Polycarbonate resins have been used in a wide range of applications because of their excellent transparency, heat resistance, mechanical properties, and electrical properties. And quality improvement is being promoted. There are many methods for improving the quality, such as copolymerization, blending, and changing terminal groups. One of the methods is to mix a plurality of polycarbonate resins having different molecular weights. For example, according to this method,
No. 57860 and JP-A-56-45945 disclose improving the viscoelasticity and fluidity of a polycarbonate resin upon melting.
Improving the flame retardancy by using the improvement of the fluidity at the time of melting is disclosed in JP-A-60-127356 and JP-A-60-2.
Japanese Patent Application Laid-Open No. H06-36666 discloses that the warpage and surface properties of a molded product are improved.
It describes improving the coating surface performance.

In order to produce such a mixed polycarbonate resin, a method is usually employed in which polycarbonate resins having different molecular weights are separately produced and then mixed. However, this method has a disadvantage that the manufacturing process and labor are complicated. Also, JP-A-58-138733 discloses that
A method of producing by a two-stage polymerization reaction has been proposed. However, it is difficult to produce a polycarbonate resin having an arbitrary molecular weight distribution by this method.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for easily preparing a polycarbonate resin showing a plurality of polymer peaks (hereinafter abbreviated as a polycarbonate resin showing a plurality of peaks) in a molecular weight distribution chart by the GPC method in one reaction system. It is another object of the present invention to provide a method for economical production.

[0005] The present inventors have result of intensive studies of the above objects as achieved plugs, two or obtained in the usual manner
The above polycarbonate oligomer solution, different concentration
The amount to be a terminal capping agent (molar ratio to the aromatic dioxy compound) was added and after respectively the emulsified state, the same polymerization system
Introduced within, when polymerized on standing without adding substantial agitation operation, surprisingly it is found that a polycarbonate resin showing a plurality of desired peaks are easily and economically obtained, the present invention Reached. It should be noted that bifurcated in the present invention
The further polycarbonate oligomer solution is separately
Even with the oligomer solution produced, one polycarbonate
Nate oligomer solution divided into two or more
It may be.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for preparing a plurality of oligomer solutions obtained by reacting an alkaline aqueous solution of an aromatic dioxy compound with phosgene in the presence of an organic solvent, in an amount of a terminating agent having different concentrations. And add each oligomer
This is a method for producing a polycarbonate resin , which comprises introducing a solution into an emulsified state, introducing the solution into the same polymerization system, and allowing the solution to stand without substantially stirring to carry out polymerization.

The aromatic dioxy compound used in the present invention is, for example, bis (4-hydroxyphenyl) methane,
1,1-bis (4-hydroxyphenyl) ethane, 2,
2-bis (4-hydroxyphenyl) propane [commonly known as bisphenol A], 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1-phenyl-1,1bis (4-
(Hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) oxide, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) sulfone, hydroquinone, resorcinol, , 4'-dihydroxydiphenyl, 2,6-dihydroxynaphthalene, and lower alkyl or halogen-substituted benzene nuclei thereof. Among them, bisphenol A is particularly preferable, and a copolymer in which a part thereof is substituted with another aromatic dioxy compound is also preferable. When two or more aromatic dioxy compounds are used, it is desirable to use those having the same reactivity.

As the alkali used for the aqueous alkali solution of the aromatic dioxy compound, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is preferable. Such a basic hydroxide is usually used as an aqueous solution, and its concentration is usually 5 to 10% by weight. The amount of the basic hydroxide used is preferably an amount exceeding the theoretical amount of 2 times the molar amount of the aromatic dioxy compound, and is preferably 2.2 to 3 times the molar amount of the aromatic dioxy compound.

As the organic solvent, for example, methylene chloride,
Chloroform, 1,2-dichloroethane, 1,1,2-
Trichloroethane, tetrachloroethane, chlorobenzene and the like. These are used alone or as a mixture. The amount of the solvent used is preferably such that the concentration of the polycarbonate oligomer in the solution becomes 10 to 30% by weight.

As the terminating agent, monohydric phenols are used. For example, phenol, p-tert-butylphenol, isopropylphenol, octylphenol, p-phenol
-Cumylphenol and the like. The amount of terminator used is determined by the desired molecular weight.

In order to produce a polycarbonate resin showing a plurality of desired peaks using the above components, first, an alkaline aqueous solution of the above aromatic dioxy compound and phosgene are reacted in the presence of an organic solvent according to a conventional method. Two or more desired molecular weight levels of the terminating agent are added to the resulting reaction mixture, followed by emulsification, respectively. The emulsified reaction mixture is introduced into a polymerization system at a desired composition ratio and polymerized. The polymerization reaction is carried out in a batch system or a continuous system in a standing state without adding a substantial stirring operation. The polymerization temperature is preferably adjusted to 25 to 35 ° C. After completion of the polymerization reaction, an organic solvent is added as required, and purification and desolvation are carried out by a conventional method to obtain a polycarbonate resin showing desired plural peaks. When stirred in the polymerization reaction, a single peak polycarbonate
Only nate resin is obtained.

[0012] The polycarbonate resin obtained by the method of the present invention has a desired molecular weight distribution, and can exhibit various performances. Further, the polycarbonate resin of the present invention, if necessary, various additives such as a flame retardant, an antistatic agent,
A release agent, a dye / pigment, a heat stabilizer, an ultraviolet stabilizer, an inorganic filler, a fibrous reinforcing agent, a photoconductive material, a charge transport material, and the like can be blended.

[0013]

The present invention will be further described with reference to the following examples. In addition, the part in an Example shows a weight part and% shows weight%.
The molecular weight distribution of the obtained polycarbonate resin was evaluated using a low angle laser light scattering photometer (LALLS) and a differential refractometer (R
This was performed using GPC equipped with I) [manufactured by Tosoh Corporation].

[0014]

Example 1 2.23 parts of bisphenol A was dissolved in 10.7 parts of a 10% aqueous sodium hydroxide solution, 9 parts of methylene chloride was added, and 1.12 parts of phosgene was reacted. To 90% of the obtained reaction mixture, 0.0261 parts of p-tert-butylphenol was added to make a highly emulsified state with a homomixer, and introduced into a polymerization tank. P-te to the remaining 10% of the reaction mixture
0.00015 part of rt-butylphenol was added, and the mixture was similarly emulsified and introduced into the same polymerization tank. The polymerization tank is 30 ~
It was kept at 32 ° C. and left for 2 hours. After completion of the reaction, methylene chloride was added to the organic phase to make the polymer concentration 10%, and the aqueous phase was separated and removed, followed by washing with water. A casting film was prepared from the obtained polymer solution and evaluated. Table 1 shows the weight average molecular weight (MW) and composition of each of the high molecular weight side and the low molecular weight side. In addition, the composition is% by weight obtained from the GPC area ratio. FIG. 1 shows a GPC (LALLS) chart of the obtained polycarbonate resin film. The horizontal axis indicates time, and the vertical axis indicates laser scattered light intensity.

As is apparent from this chart and the chart of Comparative Example 1 below, the molecular weight distribution of the polycarbonate resin obtained in Example 1 is different from that of a conventional polycarbonate resin obtained by separately producing and mixing polycarbonate resins having different molecular weights. It is almost the same as the molecular weight distribution of the mixed polycarbonate resin.

[0016]

Comparative Example 1 Emulsions obtained in the same manner as in Example 1 were separately subjected to a polymerization reaction, and the obtained polymer solutions were mixed and evaluated in the same manner as in Example 1. The results are shown in Table 1. FIG. 2 shows a GPC (LALLS) chart of the obtained polycarbonate resin film.

[0017]

Example 2 80% of the phosgenation reaction mixture obtained in the same manner as in Example 1 contained 0.07% of p-tert-butylphenol.
68 parts, 0.00% of p-tert-butylphenol in 20%
The procedure was performed in the same manner as in Example 1 except that 3 parts were added.
It was shown to.

[0018]

Comparative Example 2 Emulsions obtained in the same manner as in Example 2 were separately polymerized, and the resulting polymer solutions were mixed. The evaluation results are shown in Table 1.

[0019]

EXAMPLE 3 70% of the phosgenation reaction mixture obtained in the same manner as in Example 1 contains 0.06% of p-tert-butylphenol.
P-tert-butylphenol in 72 parts, 30% 0.00
The procedure was performed in the same manner as in Example 1 except that 177 parts were added. The results are shown in Table 1.

[0020]

Comparative Example 3 Emulsions obtained in the same manner as in Example 3 were separately subjected to a polymerization reaction, and the obtained polymer solutions were mixed. The evaluation results are shown in Table 1.

[0021]

[Table 1]

[0022]

According to the present invention, a polycarbonate resin having a molecular weight distribution similar to that of a mixed polycarbonate resin obtained by mixing and mixing polycarbonate resins having different molecular weights can be obtained simultaneously and in a single reaction system. It can be easily manufactured, and its industrial effect is extremely large.

[Brief description of the drawings]

FIG. 1 shows a GPC (LALLS) chart of the polycarbonate resin film obtained in Example 1.

FIG. 2 shows a GPC (LALLS) chart of the polycarbonate resin film obtained in Comparative Example 1.

Claims (1)

(57) [Claims] 1. A plurality obtained an alkaline aqueous solution with phosgene aromatic dioxy compounds are reacted in the presence of an organic solvent
To each oligomer solution , add a terminating agent in a different concentration to make each oligomer solution emulsified , then introduce it into the same polymerization system, and let it stand without substantially stirring to polymerize. A method for producing a polycarbonate resin, comprising: