JP2002293914A - Crystallized prepolymer of aromatic polycarbonate and method for manufacturing polycarbonate resin using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an effective method for crystallizing an amorphous polycarbonate oligomer having a low-molecular weight obtained by a melt polymerization, and an effective method for manufacturing a high-molecular weight polycarbonate resin using the crystallization method. SOLUTION: A crystallizing solvent in an amount of 2-70 wt.% is brought into contact with 100 wt.% of a solid of an amorphous aromatic polycarbonate prepolymer having an intrinsic viscosity [η] of 0.05-0.38 to crystallize it. The obtained crystallized prepolymer having a degree of crystallization of 10% to <=60% is molded into granular product, and subsequently the product is subjected to a solid phase polymerization to obtain the high-molecular weight polycarbonate resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for crystallizing an aromatic polycarbonate and a method for producing the same. More specifically, the present invention relates to an efficient method for crystallizing a low molecular weight polycarbonate and a colorant having a good hue utilizing the method. The present invention relates to a method for producing a polycarbonate resin having a low gel component.

[0002]

2. Description of the Related Art Aromatic polycarbonate is a material excellent in transparency, heat resistance and mechanical properties. It has been used for optical applications such as CDs (compact discs), optical discs and lenses, and as an engineering plastic. It is used in various fields such as applications and various containers.

[0003] As a method for producing such an aromatic polycarbonate, conventionally, an interfacial polymerization method in which phosgene and an aromatic dihydroxy compound are polymerized in water and a solvent not mixed with water, a method in which an aromatic dihydroxy compound and a carbonate bond-forming compound are used. A melt polycondensation method in which a heat-melting reaction is performed in the presence of a transesterification catalyst, and the like are used. In order to increase the degree of polymerization of the amorphous low-molecular-weight aromatic polycarbonate obtained by the above-mentioned melt polymerization (these may be referred to as polycarbonate oligomers or prepolymers), the prepolymer is crystallized. There is known a method of producing a high-molecular-weight polycarbonate resin by polymerizing in a solid phase under vacuum or under a flow of an inert gas. For example, JP-A-01-58033 and JP-A-03-223330 disclose a technique in which the prepolymer is immersed in an organic solvent or the like to be crystallized and solidified to increase the degree of polymerization.

An example in which a prepolymer is crystallized using a crystallization solvent is known from Japanese Patent No. 2,467,724.

[0005] The method of combining melt polycondensation and solid-phase polymerization has the advantage that a high molecular weight (high degree of polymerization) polycarbonate having good hue and moldability can be obtained.

However, when the prepolymer is immersed in the crystallization solvent as in the above-mentioned method, the prepolymer dissolves in the crystallization solvent, and a great amount of energy is required to separate and recover the prepolymer and the crystallization solvent. When the phase polymerization reaction is carried out in a vacuum, a large-scale vacuum apparatus and a pressure-resistant reaction tank are required, resulting in a problem that very high equipment costs are required.

On the other hand, a method of carrying out solid phase polymerization under an inert gas flow is disclosed in Japanese Patent Application Laid-Open No. H03-59028, in which the partial pressure of phenol or phenol having a substituent generated by solid phase polymerization is reduced. 0.001-5mmHg
It is described that the inert gas suppressed to the range described above is repeatedly supplied to a solid phase polymerization tank to perform solid phase polymerization. However, when the content of phenol or phenol having a substituent in the inert gas is repeatedly used within a predetermined concentration, the phenol or phenol component having a substituent contained in the gas is removed from the inert gas. -There is a problem that the efficiency of recovery becomes very poor, and from the viewpoint of environmental protection, a huge facility must be used for the recovered amount of phenol or phenol having a substituent.

Further, in order to crystallize a low molecular weight polycarbonate, Japanese Patent Application Laid-Open No. H01-158033 discloses
When various organic solvents as described in JP-A-03-223330 are used, a plurality of low molecular weight components are distilled out during solid phase polymerization, so that the recovery system becomes complicated or large-scale. In addition, there is a problem that the inert gas cannot be used for other purposes without purification because the organic solvent is mixed into the inert gas used for the solid phase polymerization.

Incidentally, JP-A-6-206996 and JP-A-6-206997 disclose a process for producing a polycarbonate by injecting an inert gas into a melt of an oligocarbonate or a diphenol and a diaryl carbonate. Is disclosed. In these, there is a description that a high-molecular-weight polycarbonate is produced by flowing a high-temperature inert gas through a polycarbonate in a molten state.However, since the melt viscosity increases with the increase in the degree of polymerization, a polymer having a high degree of polymerization is used. There is a problem that it is difficult to manufacture efficiently, and there is also a problem that the energy cost due to the heating of the inert gas becomes extremely large.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently crystallizing an amorphous low-molecular-weight polycarbonate oligomer obtained by melt polymerization and an efficient method for producing a high-molecular-weight polycarbonate resin using the same. It is to provide a manufacturing method.

[0011]

The present invention has the following configuration to achieve the above object.

That is, the intrinsic viscosity [η] is 0.05 to 0.3.
8 is a crystallized prepolymer having a crystallinity of 10% to 60% or less, which is crystallized by bringing a crystallization solvent into contact with 100% by weight of an amorphous aromatic polycarbonate prepolymer solid in 2 to 70% by weight.

Further, the crystallized prepolymer is a crystallized prepolymer obtained by removing a part or all of the crystallization solvent by heating or heating and reducing the pressure.

Further, the amorphous aromatic polycarbonate is an aromatic polycarbonate obtained by a melt polymerization method.

Further, the crystallization solvent is a crystallization solvent containing a monohydroxy compound.

Further, the monohydroxy compound is an aromatic hydroxy compound.

Further, the aromatic hydroxide compound is phenol.

The granular compact is a granular compact obtained by granulation while maintaining the crystallized state of the crystallized prepolymer.

The granular compact is a granular compact obtained by extruding the crystallized prepolymer from the pores of a die and cutting it.

Alternatively, the granular compact is a granular compact obtained by compressing and granulating the crystallized prepolymer.

The granular molded article of the aromatic polycarbonate obtained by any of the above-mentioned methods is heated at a temperature lower than the melting point of the crystallized prepolymer under reduced pressure or under an inert gas stream to obtain a high degree of polymerization. A method for producing a polycarbonate resin, comprising:

That is, according to the constitution of the present invention, the crystallization solvent is continuously pulverized while continuously mixing and kneading while being continuously supplied to the amorphous low molecular weight aromatic polycarbonate solid, and the crystallization is gradually carried out by heating or heating and pressure reduction. Crystallization is performed while removing the solvent, and then granulation is performed.The obtained granular molded product is heated at a temperature lower than the crystal melting point under reduced pressure or an inert gas stream to increase the degree of polymerization by solid phase polymerization. And a method for producing a polycarbonate resin, characterized in that the crystallized prepolymer or the granular molded product obtained by the method or the granular molded product is made to have a high degree of polymerization by solid phase polymerization.

[0023]

Embodiments of the present invention will be described in detail below.

The aromatic polycarbonate prepolymer preferably used in the present invention is, for example, 2,2-bis (4
-Hydroxyphenyl) propane is an aromatic polycarbonate obtained by melt polycondensation of diphenyl carbonate.Other aromatic polycarbonates may be used as long as they are prepolymers of aromatic polycarbonate that crystallize upon contact with a crystallization solvent. It can be used as a prepolymer of the invention. As described above, in the present invention, an aromatic polycarbonate obtained from a combination of monomers described in JP-A-2001-011171 and an aromatic polycarbonate described in JP-A-7-292096 are described. Can be used as the prepolymer of the present invention.

The mixing / kneading apparatus is not particularly limited, but it is essential that the crystallization solvent be in contact with the amorphous low molecular weight aromatic polycarbonate prepolymer. Examples of such an apparatus include a single-screw extruder, a twin-screw extruder, and a twin-screw kneader.

Preferred solvents that can be used as the crystallization solvent include, for example, chloromethane, methylene chloride, chloroform, carbon tetrachloride, chloroethane, dichloroethane,
Aliphatic halogenated hydrocarbons such as trichloroethane, trichloroethylene, and tetrachloroethane; aromatic halogenated hydrocarbons such as chlorobenzene and dichlorobenzene; ethers such as tetrahydrofuran and dioxane; esters such as methyl acetate and ethyl acetate; acetone; Examples include ketones such as methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene, xylene, and aromatic hydroxy compounds such as phenol. These solvents may be used alone or as a mixture of two or more, but it is preferable to use them alone from the viewpoint of the solvent recovery process.

A second feature of the present invention is that crystallization is carried out using a solvent containing a monohydroxy compound as the crystallization solvent. Most preferably, it is used for a crystallization solvent containing an aromatic monohydroxy compound, more preferably phenol. In particular, the mixed solvent of crystallization solvent and water generated from the prepolymer polymerization step can be easily obtained with high purity and at low cost, so that contamination as impurities in the product polycarbonate resin is reduced, and the cost competitiveness is high. It has great advantages. Furthermore, when the crystallization solvent generated from the polymerization step is used alone or as a mixed solvent with water, it is possible to prevent the undesired compound from being mixed into the above-mentioned inert gas flowing through the melt polycondensation reaction tank. In particular, when melt polycondensation is performed using diphenyl carbonate as a carbonate bond forming compound, phenol is generated by the reaction, so that there is no problem even if phenol is contained in the inert gas flowing in the melt polycondensation, Therefore, it is preferable to use phenol as the crystallization solvent. When phenol is used as a crystallization solvent, even if the phenol component remaining in the prepolymer evaporates in the solid-state polymerization step and is contained in the inert gas, it can be supplied to the melt polycondensation step without any problem. Energy cost for separation and recovery can be reduced. Also, the method of using phenol for crystallization,
This is the most preferable since there is an advantage that the solvent recovery in the melt polycondensation step and the crystallization step can be unified. Since the depolymerization of the prepolymer proceeds with phenol, a method of shortening the solvent contact time and recovering quickly is preferable. In order to adjust the time until the depolymerization proceeds, an arbitrary diluted solution with water as described above may be more preferable. Phenol content is 10 wt%
It is preferably at least 90 wt%. More preferably, it is in the range of 10 wt% to 50 wt%.

It is necessary that the amount of the crystallization solvent be as small as possible. If the addition amount is too large, the energy cost required for solvent recovery is increased, which is not preferable and fine pulverization becomes difficult. On the other hand, if the amount is too small, crystallization is not sufficiently performed, so that the fusion of the granular molded bodies during the solid phase polymerization cannot be avoided, and the load on the mixing / kneading apparatus increases, making fine pulverization difficult. It may be carried out at a relatively low temperature in order to avoid fusion during solid phase polymerization, but this case is not preferred because it leads to a longer solid phase polymerization time. The solvent may be added through, for example, a hopper or a vent hole in the case of an extruder. As the amount of addition, the amount of the organic solvent in the prepolymer is in the range of 2 to 70% by weight. Preferably 10
It is in the range of 50 wt%, more preferably 15 to 45 wt%.

In the present invention, the time required for crystallization of the prepolymer (amorphous low molecular weight aromatic polycarbonate prepolymer) depends on the amount of the crystallization solvent, the composition of the crystallization solvent, the degree of polymerization of the prepolymer, Transition temperature (T
g), although it depends on the particle size of the prepolymer, etc., it is approximately several tens seconds to several tens of minutes. However, if the crystallization temperature is not properly selected, it may take several hours or more. If the particle size of the prepolymer is large, the surface area is reduced, so that the amount of the crystallization solvent in contact is reduced, and as a result, uniform crystallization cannot be achieved. Therefore, it is preferably 10 mm or less. The particle size is preferably 5 mm or less, more preferably 2 mm or less.

The crystallinity of the crystallized prepolymer is as follows:
Usually, it is 10% to 60%. If the degree of crystallinity is less than 10%, the possibility of fusion of the particles during solid phase polymerization increases, which is not preferable. If the degree of crystallinity is 60% or more, production is substantially difficult. The crystallinity of the crystallized prepolymer is 15-
50% is preferred, more preferably 20-40%.

Subsequently, the crystallized prepolymer is heated and depressurized, or both, while recovering the solvent, into a powdery material and granulated to obtain a granular molded product. Insufficient solvent recovery causes problems such as fusion of the granular compacts during the solid-state polymerization process and prolongation of the polymerization rate. Therefore, the content of the crystallization solvent in the crystallization prepolymer is preferably at most 30%, more preferably at most 10%. When the content of the crystallization solvent in the crystallized prepolymer is large, it is preferable to perform drying at a temperature higher than the glass transition temperature of the crystallized prepolymer and lower than the melting point. More preferably, the temperature of the mixer / kneader to be used is set to a temperature at which the crystallized prepolymer does not melt on the supply side, and the temperature is gradually increased at the outlet side of the mixer / kneader after the crystallization solvent uniformly contacts the prepolymer. This is a method of recovering the crystallization solvent from the vent hole or the like.

The granulation is not particularly limited, but can be easily carried out by a usual granulation method such as a rolling method, a vibration method, a compression molding method and an extrusion molding method. Among these granulation methods, extrusion granulation and compression granulation are particularly preferred. Examples of the extrusion granulation method include a screw method, a roll-type cylindrical die method, and a roll-type disk die method. Examples of the compression granulation method include a compression roll method, a briquetting method, and a tableting method. Further, from the viewpoint of production efficiency, a compact formed by a compression roll method may be pulverized to have a uniform particle diameter. The shape and particle size of the molded body are not particularly limited, but usually, a pellet, a sphere, a flake, a column, a disk, a polygonal column, a cube, a rectangular parallelepiped, a cylinder, a lens, and the like are possible. . The particle size is usually in the range of 0.5 mm to 50 mm. Preferably 0.5 mm to 30 mm, more preferably 1.0 m
m to 10 mm. The pressed strength of the granulated product is 3
A strength of not less than kg weight / cm ² is required. If the strength is lower than this compressive strength, a large amount of dust will be generated in the steps of transporting, supplying and discharging the granulated molded product, and blockage, adhesion,
Undesirable phenomena such as aggregation occur.

In the solid-phase polymerization step, the flow rate of the inert gas to be circulated is substantially 1 K of a molten mixture of an aromatic dihydroxy compound and a carbonate bond-forming compound.
It is preferably 1 to 500 NL / min per g, particularly 5 to 10 NL / min.
0 NL / min is particularly preferred. If the flow rate is smaller than the above range, the progress of the melt polycondensation reaction is slowed, and the polymer is likely to be colored or gelled, which is not preferable. When the circulation amount is larger than the above range, the heat energy cost is undesirably increased.

In the present invention, in the melt polycondensation step, a molten mixture consisting essentially of an aromatic dihydroxy compound and a carbonate bond-forming compound may be subjected to polymerization under reduced pressure. You may do it. That is, although there is no particular limitation on the method of flowing the above-described inert gas, a vertical portion having a polymer discharge port, an inert gas flow pipe and an inert gas jet port at the bottom, and a cooling pipe and a raw material flow pipe at the top is provided. A method is preferred in which the temperature of the inert gas is controlled by a temperature controller using a mold reactor, and then the inert gas is passed through the reactor. The inert gas is usually passed from the beginning of the melt polycondensation reaction to the end of the reaction. The inert gas is preferably supplied so as to blow directly into the molten mixture.

The intrinsic viscosity [η] of the prepolymer produced in such a melt condensation polymerization step is preferably from 0.1 to 0.38. The intrinsic viscosity [η] of the aromatic polycarbonate in the present invention is a value calculated from the viscosity measured at a temperature of 20 ° C. in a dichloromethane solution.

If the intrinsic viscosity [η] of the prepolymer is lower than the above range, it is difficult to obtain a crystallized prepolymer having a melting point sufficient to carry out the subsequent solid phase polymerization reaction, It is not preferable because volatile components generated during the reaction become too large. On the other hand, intrinsic viscosity [η]
If it exceeds the above range, the production of the prepolymer takes too long, and in some cases, coloring, gelation, etc. occur,
Not preferred. The preferred intrinsic viscosity [η] of the polycarbonate prepolymer in the present invention is 0.10 to 0.3.
0, more preferably in the range of 0.12 to 0.25.

According to the present invention, the prepolymer produced as described above is crystallized in the next step, and then further increased in molecular weight by solid phase polymerization.

In the present invention, the crystallized prepolymer is heated in an inert gas stream at a temperature equal to or lower than the melting point of the crystallized prepolymer in a solid state, whereby solid state polymerization is carried out. Molecular weight, intrinsic viscosity [η]
An aromatic polycarbonate having a desired molecular weight of 3 to 1.0 is obtained.

As the solid phase polymerization temperature, about 150 to 350 ° C. is appropriate. Although a higher solid phase polymerization temperature is preferable in terms of the polymerization rate, it is necessary to carry out the polymerization at a temperature lower than the melting point of the crystallized prepolymer in order to prevent fusion of the crystallized prepolymer. Further, since the melting point of the crystallized prepolymer increases with the degree of polymerization, a method of sequentially increasing the solid-state polymerization temperature with the increase in the melting point is also preferably used.

When the aromatic polycarbonate is, for example, 2,2
In the case of an aromatic polycarbonate obtained by melt-polycondensation of -bis (4-hydroxyphenyl) propane and diphenyl carbonate, the solid-state polymerization reaction is preferably performed at 220 ± 20 ° C, and particularly preferably 220 to 230 ° C.

The time required for solid-state polymerization is usually several hours to
Dozens of hours are employed. If the polymerization time is too long, the equipment used for solid-state polymerization becomes large, which is not preferable in terms of equipment manufacturing costs.

In the solid-state polymerization step, the type of the inert gas passed through the solid-state polymerization tank includes helium, argon,
Examples include nitrogen and carbon dioxide gas. The flow rate of the inert gas is preferably at least 0.1 NL / min per 1 kg of the crystallized prepolymer, and particularly preferably 1 to 50 NL / min. If the flow rate is smaller than the above range, the progress of the solid-state polymerization reaction is slow, and the polymerization time is undesirably long. When the circulation amount is larger than the above range, the heat energy cost is undesirably increased.

In the present invention, the flow rate of the inert gas flowing through the solid phase polymerization tank and the flow rate of the inert gas flowing through the prepolymer melt polycondensation tank are not necessarily the same. Inert gas may be introduced into one low-molecular-weight aromatic polycarbonate melt polycondensation tank from two or more solid-state polymerization tanks being carried out in parallel. Some may be used for other purposes. However, it is preferable to make the flow rate of the inert gas flowing through the solid-state polymerization tank equal to the flow rate of the inert gas flowing through the prepolymer melt polycondensation tank because the apparatus becomes simpler.

During the solid phase polymerization, the crystallized prepolymer may be stirred mechanically or under a gas flow.

There is no particular limitation on the type of the solid phase polymerization tank used in the present invention, but a vertical reactor having an inert gas inlet at the bottom and an inert gas outlet at the top,
A rotary reactor or the like can be exemplified as a preferred embodiment.

When the amount of inert gas discharged from the solid-state polymerization tank and the amount of inert gas supplied to the molten polycondensation tank are not balanced, and the amount of gas discharged in solid-state polymerization is excessive, May be used for other purposes. When the gas amount is insufficient, a new inert gas may be supplemented to the exhaust gas and supplied to the melt polycondensation step.

Aromatic polycarbonate having a desired degree of polymerization (hereinafter sometimes referred to as "polycarbonate resin") produced by solid-state polymerization as described above has a good hue, a small amount of gel component and excellent moldability. However, if necessary, a terminal hydroxy group blocking reaction and stabilization of the melt viscosity can be carried out, which is preferable from the viewpoint of improving the heat stability at the time of molding the polycarbonate resin and the durability stability.

As a method for blocking the terminal hydroxy group of the polycarbonate resin, the polycarbonate resin after the completion of the polymerization reaction is melt-mixed with a polymer such as a twin screw extruder, for example, as described in US Pat. No. 5,696,222. According to the method described, the terminal hydroxyl group can be blocked with a salicylate compound. in this case,
The amount of the salicylate compound to be used is 0.8 to 10 mol, more preferably 0.8 to 5 mol, particularly preferably 0.9 to 2 mol, per one chemical equivalent of the terminal hydroxyl group in the polymer before the capping reaction. Good range. By adding at such a ratio, 80% or more of the terminal hydroxyl groups can be suitably sealed.

Depending on the purpose of use, the polycarbonate resin produced according to the present invention may contain various additives such as a release agent, a heat stabilizer, an ultraviolet absorber, a colorant, an antistatic agent, and inorganic agents such as glass fibers, minerals and fillers. Further, by mixing a polymer other than the polycarbonate resin, the resin can be used as a molding resin, a film, or a fiber in a conventional application of the polycarbonate resin.

[0050]

According to the present invention, a crystallized low molecular weight aromatic polycarbonate prepolymer can be efficiently produced by bringing a small amount of a crystallization solvent into contact with the amorphous low molecular weight aromatic polycarbonate prepolymer. In addition, when the product distilled off from the reaction system is used as a crystallization solvent, the chemical cost is reduced without adding a new solvent to the system,
In addition, since the energy required for recovery can be reduced, it can be manufactured at extremely low cost. Solid-state polymerization using the obtained crystallized aromatic polycarbonate prepolymer can give a molded product that is gel-free and has good hue and moldability.

[0051]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. 1) Intrinsic viscosity [η] of aromatic polycarbonate Measured in dichloromethane at 20 ° C. using an Ubbelohde viscosity tube. 2) Glass transition temperature (Tg) and melting point The glass transition temperature (Tg) and the melting point were measured by a Perkin Elmer DSC7 at a heating rate of 20 ° C./min. The enthalpy of crystal melting (ΔH) was calculated from the area of the portion corresponding to the crystal melting. 3) Crystallinity The crystallinity was calculated from ΔH obtained by DSC measurement as 1
The ΔH of 00% crystallized polycarbonate was determined using the Journal of Polymer Science; Part B: Polymer Physics (J. Polym. Sci .: B: Poly).
m. Phys. 1979 Vol. 25, 151-151
The calculation was made at 109.8 J / g with reference to page 7.

[Synthesis example of low molecular weight aromatic polycarbonate] 228 parts by weight of 2,2'-bis (4-hydroxyphenyl) propane, 223 parts by weight of diphenyl carbonate and 0.009 of tetramethylammonium hydroxide
Parts by weight and bisphenol A disodium salt 0.000
14 parts by weight were charged into a reactor equipped with a stirrer, a decompression device, a distillation column, and the like, and were stirred and dissolved at 180 ° C. in a nitrogen atmosphere for 30 minutes. Then, simultaneously with the temperature rise, gradually reduce the pressure,
Finally, the temperature was set to 220 ° C. and 30 mmHg. at this point,
The intrinsic viscosity [η] of the obtained low molecular weight polycarbonate (oligomer) is 0.15 and the glass transition temperature (Tg) is 1
16 ° C.

Example 1 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged into a mixing tank equipped with a vertical twin-screw kneader, and stirred at a stirring speed of 100 rpm. Solvent acetone 1
While gradually adding 25 g, the temperature of the stirring tank was raised to a final temperature of 50 ° C., and acetone was gradually recovered to obtain a powdery crystallized prepolymer. The melting point of the obtained crystallized prepolymer was 225 ° C., and ΔH was 24 J / g (crystallinity: 22%).

Then, the powdered crystallized prepolymer was subjected to compression at a compression force of 100 MPa using a shape-wave type compression granulator to obtain a granulated product. The obtained plate-shaped compression molded product was screened with a screen diameter of 3 to
It was pulverized using a 5 mm hammer crusher type crusher to obtain a granular polycarbonate prepolymer. This polycarbonate prepolymer granule has an average particle size of 2
４4 mm.

The polycarbonate granules are placed in a cylindrical reaction vessel having an inert gas outflow portion at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
53.

Example 2 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged, and the mixture was stirred with a twin-screw extruder. 125 g of acetone as a crystallization solvent was gradually added. While stirring, the temperature of the stirring tank was raised to a final temperature of 50 ° C., and acetone was gradually recovered to obtain a powdery crystallized prepolymer. The melting point of the obtained crystallized prepolymer is 224 ° C., ΔH is 24 J / g.
(Crystallinity: 22%).

Then, the powdered crystallized prepolymer was subjected to compression at a compression force of 100 MPa using a shape-wave type compression granulator to obtain a granulated product. The obtained plate-shaped compression molded product was screened with a screen diameter of 3 to
It was pulverized using a 5 mm hammer crusher type crusher to obtain a granular polycarbonate prepolymer. This polycarbonate prepolymer granule has an average particle size of 3
４4 mm.

The granular crystallized prepolymer is placed in a cylindrical reaction vessel having an inert gas outlet at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
It was 50.

Example 3 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged into a mixing tank equipped with a vertical twin-screw kneader, and stirred at a stirring speed of 100 rpm. While gradually adding 125 g of a crystallization solvent, toluene, the temperature of the stirring tank was raised to a final temperature of 90 ° C., and toluene was gradually recovered to obtain a powdery crystallized prepolymer. The melting point of the obtained crystallized prepolymer is 226 ° C., ΔH is 25 J / g (crystallinity: 23
%)Met.

Then, the powdered crystallized prepolymer was subjected to compression at 100 MPa using a shape-wave type compression granulator to obtain a granulated product. The obtained plate-shaped compression molded product was screened with a screen diameter of 3 to
It was pulverized using a 5 mm hammer crusher type crusher to obtain a granular polycarbonate prepolymer. This polycarbonate prepolymer granule has an average particle size of 2
４4 mm.

The polycarbonate granules are placed in a cylindrical reaction vessel having an inert gas outlet at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
53.

Example 4 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged into a mixing tank equipped with a vertical twin-screw kneader, and stirred at a stirring speed of 100 rpm. While gradually adding 125 g of crystallization solvent xylene, the temperature of the stirring tank was raised to a final temperature of 140 ° C., and xylene was gradually recovered to obtain a powdery crystallized prepolymer. The melting point of the obtained crystallized prepolymer is 227 ° C., ΔH is 25 J / g (crystallinity: 23
%)Met.

Then, the powdery crystallized prepolymer was subjected to a compression force of 100 MPa using a shape-wave type compression granulator to obtain a granulated product. The obtained plate-shaped compression molded product was screened with a screen diameter of 3 to
It was pulverized using a 5 mm hammer crusher type crusher to obtain a granular polycarbonate prepolymer. This polycarbonate prepolymer granule has an average particle size of 2
４4 mm.

The polycarbonate granules were placed in a cylindrical reaction vessel having an inert gas outflow portion at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
52.

Example 5 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged and stirred with a twin-screw ruder, and 56 g of phenol as a crystallization solvent was gradually added. The temperature of the stirring tank was raised while raising the final temperature to 190 ° C., and phenol was gradually recovered to obtain a powdery crystallized prepolymer. The melting point of the obtained crystallized prepolymer is 227 ° C., ΔH is 26 J / g.
(Crystallinity: 24%).

Then, the powdery crystallized prepolymer was subjected to a compression force of 100 MPa using a shape-wave type compression granulator to obtain a granulated product. The obtained plate-shaped compression molded product was screened with a screen diameter of 3 to
It was pulverized using a 5 mm hammer crusher type crusher to obtain a granular polycarbonate prepolymer. This polycarbonate prepolymer granule has an average particle size of 3
４4 mm.

The granular crystallized prepolymer is placed in a cylindrical reaction vessel having an inert gas outlet at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
52.

Example 6 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged, and the mixture was stirred with a twin-screw extruder to obtain a mixed solvent of phenol as a crystallization solvent and water. (2: 8) to 5
While gradually adding 6 g, the temperature of the stirring tank was raised to a final temperature of 190 ° C., and phenol was gradually recovered to obtain a powdery crystallized prepolymer. The melting point of the obtained crystallized prepolymer is 226 ° C., ΔH is 23 J / g (crystallinity: 21%).
Met.

Next, the powdery crystallized prepolymer was subjected to a compression force of 100 MPa using a shape-wave type compression granulator to obtain a granulated product. The obtained plate-shaped compression molded product was screened with a screen diameter of 3 to
It was pulverized using a 5 mm hammer crusher type crusher to obtain a granular polycarbonate prepolymer. This polycarbonate prepolymer granule has an average particle size of 2
４4 mm.

The granular crystallized prepolymer is placed in a cylindrical reaction vessel having an inert gas outlet at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
It was 50.

Example 7 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was stirred with an extruder, and stirred while gradually adding 56 g of phenol as a crystallization solvent. The temperature of the bath was raised to a final temperature of 190 ° C., and phenol was gradually recovered, and a hole of 2 mm in diameter and 5 mm in land was formed at the outlet.
A plurality of dies were provided, and a granular compact was obtained in front of the dies by a cutter at an interval of 4 mm. The obtained molded body is
Dry at 3 ° C. for 3-4 hours. The melting point of the crystallized prepolymer constituting the molded product was 225 ° C., and ΔH was 30 J / g (crystallinity: 27%).

The granular crystallized prepolymer is placed in a cylindrical reaction vessel having an inert gas outlet at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
51.

Example 8 500 g of the amorphous low-molecular-weight polycarbonate obtained in [Synthesis Example of Low-Molecular-Weight Aromatic Polycarbonate] was charged and stirred by an extruder to obtain a mixed solvent (weight: phenol / water). Ratio 2: 8) 5
While gradually adding 6 g, the temperature of the stirring tank was raised to a final temperature of 190 ° C., and water and phenol were gradually recovered. A die having a diameter of 2 mm and 82 holes of land 5 mm was provided at the outlet, and a die was provided in front of the die. Granular compacts were obtained with a cutter at intervals of 4 mm. The obtained molded body is kept at 120 ° C. for 3 hours or more.
Dried for 4 hours. The melting point of the crystallized prepolymer constituting the molded product is 225 ° C., and ΔH is 28 J / g (crystallinity: 26
%)Met.

The granular crystallized prepolymer is placed in a cylindrical reaction vessel having an inert gas outlet at the bottom,
200 ℃ at 0.8 NL / cm ² · min under nitrogen gas flow
For 3 hours, then raise the temperature to 210 ° C. for 3 hours,
A solid-state polymerization reaction was performed at 0 ° C. for 3 hours and at 230 ° C. for 6 hours. The intrinsic viscosity [η] of the obtained polycarbonate is 0.1.
52.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirotaka Suzuki 2-1 Hinode-machi, Iwakuni-shi, Yamaguchi Prefecture Teijin Co., Ltd. Inside the Iwakuni Research Center (72) Inventor Hironori Haga 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Prefecture Teijin F term in Iwakuni Research Center Co., Ltd. (reference) 4F070 AA50 AB19 AC36 AC37 AE28 DA08 DA52 DA55 4J029 AA09 AB04 AC01 AD08 BB13A HC05A JB193 JD05 KB26 KE12 KF02 KF04 KF07 KH08

Claims (10)

[Claims] An amorphous polycarbonate prepolymer solid 10 having an intrinsic viscosity [η] of 0.05 to 0.38 and an amorphous state.
Crystallized prepolymer having a degree of crystallinity of 10% to 60% crystallized by contacting 0% by weight of a crystallization solvent with 2% to 70% by weight 2. The crystallized prepolymer according to claim 1, wherein the crystallized prepolymer is a crystallized prepolymer obtained by removing a part or all of the crystallization solvent by heating or heating and reducing the pressure. 3. The crystallized prepolymer according to claim 1, wherein the amorphous aromatic polycarbonate is an aromatic polycarbonate obtained by a melt polymerization method. 4. The crystallization prepolymer according to claim 1, wherein the crystallization solvent contains a monohydroxy compound. 5. The crystallized prepolymer according to claim 1, wherein said monohydroxy compound is an aromatic hydroxy compound. 6. The crystallized prepolymer according to claim 1, wherein said aromatic hydroxide compound is phenol. 7. A granular molded product obtained by granulating the crystallized prepolymer according to claim 1 while maintaining the crystalline state thereof. 8. The granulated product obtained by extruding the crystallized prepolymer through pores of a die and cutting the same.
The granular molded article according to the above. 9. The granular molded article according to claim 7, wherein the granular molded article is obtained by compressing and granulating the crystallized prepolymer. 10. A method for producing a granular molded article of an aromatic polycarbonate obtained by the method according to any one of claims 7 to 9 at a temperature lower than the melting point of the crystallized prepolymer under reduced pressure or an inert gas stream. A method for producing a polycarbonate resin, comprising heating to increase the degree of polymerization.