JPH07216098A - Method for producing polycarbonate particulate material - Google Patents

Abstract

PURPOSE:To obtain the subject material high in bulk density and good in dryness by removing only a good solvent having a low boiling point from a polycarbonate (PC) organic solvent solution containing the PC and two kinds of solvents having mutually different boiling points. CONSTITUTION:A PC organic solvent solution (preferably having its concentration of 7-35wt.%) consisting of the PC, at least a solvent A good for the PC and having a boiling point of <100 deg.C (preferably 30-70 deg.C) under the atmospheric pressure (preferably dichloromethane), and at least a solvent B good for the PC and having a boiling point exceeding 100 deg.C (preferably 120-180 deg.C) under the atmospheric pressure (preferably chlorobenzene) is subjected to the removal of at least 90wt.% of the solvent A at a temperature higher than the boiling point of the solvent A and lower than the boiling point of the solvent B to obtain the objective PC particles. The particles contain preferably 1-50wt.% of the solvent B.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing polycarbonate granules. More specifically, it relates to a method for producing a polycarbonate granule having a high bulk density and good drying property.

[0002]

2. Description of the Related Art Conventionally, a method for producing polycarbonate granules from a solution of polycarbonate in an organic solvent has been known. JP-B-36-21033 discloses that an organic solvent is used to form a gelled product of polycarbonate or a gelled product of polycarbonate containing water, and then the gelled product is pulverized by a mechanical method, followed by desolvation, A method for producing a polycarbonate powder or granules, characterized in that it is dried, is described. In this publication, dichloromethane, chlorobenzene or o-dichlorobenzene is used alone as an organic solvent when gelling an organic solvent solution of polycarbonate.

Japanese Unexamined Patent Publication No. 53-137297 describes a method for isolating solid polycarbonate from a good solvent solution of polycarbonate. In this method, a poor solvent is added to a good solvent solution of polycarbonate, and then a mixed solvent solution of the polycarbonate is heated and concentrated to a concentration of 30% by weight or more in terms of solid matter, and thereafter,
A method for obtaining a solid polycarbonate having a high bulk density, which is easily crushed, characterized by rapidly cooling the concentrated liquid. US Pat. No. 3,505,273 describes a method of reducing the solvent content of polycarbonate solutions. This method involves mixing a polycarbonate solution with hot water at a rate such that the solvent is slowly volatilized from the polycarbonate and crushing the solvent with a boiling point below about 100 ° C. at atmospheric pressure of about 25 to about 70%. This is a method for forming an easily gel-like material, in which most of the solvent is insoluble in water, and the hot water is at a temperature higher than the boiling point of the solvent.

GB-A-1283335 describes a method of recovering polycarbonate from a solution of a polycarbonate in a first solvent. This method uses a atomized fluid containing at least 80% of a vapor of a second solvent of at least one polycarbonate to form a solution of the first solvent in the form of a fine dispersion sprayed with a heated inert gas. The method is characterized in that the solvent is removed from the dispersion by introducing it into the countercurrent to separate the solid obtained, and the polycarbonate is obtained as a powder.
In this publication, the polycarbonate granules produced are described in
It is described as containing 10% residual solvent. However, using any of the above methods, the obtained polycarbonate granules have a low bulk density and poor dryability. At present, there is a demand for a method for producing a polycarbonate granule having a high bulk density and good drying property.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a polycarbonate granule having a high bulk density and good drying property.

[0006]

The present inventors have completed the present invention as a result of earnestly investigating a method for producing a polycarbonate granular material in order to meet the above-mentioned demand. That is, the present invention is a method for producing a polycarbonate granules from an organic solvent solution of polycarbonate, wherein the polycarbonate and a good solvent A for a polycarbonate having a boiling point under atmospheric pressure of less than 100 ° C.,
From an organic solvent solution of a polycarbonate containing at least one polycarbonate having a boiling point of more than 100 ° C. under normal pressure and a good solvent B, at a temperature higher than the boiling point of the solvent A and lower than the boiling point of the solvent A, 90
The present invention relates to a method for producing polycarbonate granules, which comprises removing polycarbonate by weight to obtain polycarbonate granules.

The polycarbonate used in the production method of the present invention is an aliphatic polycarbonate or an aromatic polycarbonate, preferably an aromatic polycarbonate. Polycarbonate is produced by an interfacial polymerization method, a solution polymerization method or a transesterification method, preferably an interfacial polymerization method. The interfacial polymerization method is, for example, a method of producing a polycarbonate by reacting a dihydroxy compound and a carbonate precursor by the action of a base in a two-phase mixed solution of water and an organic solvent. In that case, you may use a polycarbonate production catalyst, a terminal blocking agent, and / or a branching agent. The polycarbonate obtained is then washed. As the cleaning treatment of the polycarbonate, the organic phase containing the polycarbonate and the aqueous phase are separated, the organic phase containing the polycarbonate is washed with water or a dilute aqueous alkaline solution, if necessary, and then neutralized with a dilute aqueous acid solution. To do. The acid used at that time is a mineral acid such as hydrochloric acid, sulfuric acid or phosphoric acid. Then, it is repeatedly washed with water until the electrolyte is substantially absent to obtain a polycarbonate solution.

In the polycarbonate solution thus obtained, a part of the organic solvent is removed and / or a new organic solvent is added, if necessary, to obtain the polycarbonate organic solvent solution of the present invention. . The polycarbonate organic solvent solution may be prepared by dissolving a polycarbonate solid in an organic solvent, or may be prepared by another method. The average molecular weight of the polycarbonate is not particularly limited, and the one having a weight average molecular weight of about 15,000 to about 150,000, preferably about 20,000 to about 100,000 is usually used.

The dihydroxy compound used as the raw material for the polycarbonate is an aromatic dihydroxy compound or an aliphatic dihydroxy compound. The aromatic dihydroxy compound is preferably a compound represented by the formula (1) or the formula (2). HO-Ar ₁ -Y-Ar ₂ -OH (1) HO-Ar ₃ -OH (2) (In the formula, Ar ₁ , Ar ₂ and Ar ₃ are each a divalent aromatic group, and Y is Ar ₁ In Formula (1) or Formula (2), which represents a linking group for connecting Ar ₂ , Ar ₁ , Ar ₂ and Ar ₃
Are each a divalent aromatic group, preferably a substituted or unsubstituted phenylene group. The substituent of the substituted phenylene group is a halogen atom, a nitro group, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group, an alkoxy group or the like. Ar ₁ and Ar ₂ are preferably both p-phenylene groups which may have a substituent, m-phenylene groups or o-phenylene groups, or one of which is a p-phenylene group, and one of which is a p-phenylene group. It is an m-phenylene group or an o-phenylene group. Particularly preferred are p-phenylene groups, both of which may have a substituent.

Ar ₃ is an optionally substituted p-phenylene group, m-phenylene group or o-phenylene group, and preferably an optionally substituted p-phenylene group or It is an m-phenylene group. Y is a linking group that connects Ar ₁ and Ar ₂ , and is a single bond or a divalent hydrocarbon group, or —O—, —S—, —SO—, —SO.
A group containing atoms other than carbon and hydrogen, such as _2- and -CO-. Examples of the divalent hydrocarbon group include an alkylidene group such as a methylene group, an ethylene group, a 2,2-propylidene group and a cyclohexylidene group, an alkylidene group substituted with an aryl group, an aromatic group and other unsaturated groups. It is a hydrocarbon group containing a hydrocarbon group of.

Specific examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane, bis (2-methyl-4-hydroxyphenyl) methane, bis (3-methyl-4-hydroxyphenyl) methane, 1,1. -Bis (4'-hydroxyphenyl) ethane, 1,2-bis (4'-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis ( 4'-
Hydroxyphenyl) -1-phenylethane, 1,3-
Bis (4'-hydroxyphenyl) -1,1-dimethylpropane, 2,2-bis (4'-hydroxyphenyl)
Propane ["bisphenol A"], 2- (4'-hydroxyphenyl) -2- (3 "-hydroxyphenyl)
Propane, 1,1-bis (4'-hydroxyphenyl)
-2-methylpropane, 2,2-bis (4'-hydroxyphenyl) butane, 1,1-bis (4'-hydroxyphenyl) -3-methylbutane, 2,2-bis (4'-
Hydroxyphenyl) pentane, 2,2-bis (4'-
Hydroxyphenyl) -4-methylpentane, 2,2-
Bis (4'-hydroxyphenyl) hexane, 4,4-
Bis (4'-hydroxyphenyl) heptane, 2,2-
Bis (4'-hydroxyphenyl) nonane,

Bis (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3'-methyl-4'-
Hydroxyphenyl) propane, 2,2-bis (3'-
Isopropyl-4'-hydroxyphenyl) propane,
2,2-bis (3'-sec-butyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-tert-butyl-4'-hydroxyphenyl) propane, 2,2-bis (3 '-Cyclohexyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-allyl-4'-hydroxyphenyl) propane, 2,2-bis (3 ',
5'-dimethyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-chloro-4'-hydroxyphenyl) propane, 2,2-bis (3 ', 5'-dichloro-4'-hydroxy) Phenyl) propane, 2,2-bis (3'-bromo-4'-hydroxyphenyl) propane, 2,2-bis (3 ', 5'-dibromo-4'-hydroxyphenyl) propane, 2,2-bis Bis (hydroxyaryl) alkanes such as (4′-hydroxyphenyl) hexafluoropropane,

1,1-bis (4'-hydroxyphenyl) cyclopentane, 1,1-bis (4'-hydroxyphenyl) cyclohexane, 1,1-bis (3'-methyl-4'-hydroxyphenyl) cyclohexane , 1,1
-Bis (3 ', 5'-dimethyl-4'-hydroxyphenyl) cyclohexane, 1,1-bis (3', 5'-dichloro-4'-hydroxyphenyl) cyclohexane,
1,1-bis (4'-hydroxyphenyl) -3,3,
5-trimethylcyclohexane, 1,1-bis (4'-hydroxyphenyl) cycloheptane, 2,2-bis (4'-hydroxyphenyl) norbornane, 2,2-
Bis (hydroxyaryl) cycloalkanes such as bis (4′-hydroxyphenyl) adamantane, 4,4′-
Bis (hydroxyaryl) ethers such as dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, ethylene glycol bis (4-hydroxyphenyl) ether,

4,4'-dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5,5'-tetramethyl-4,4'
-Bis (hydroxyaryl) sulfides such as dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, bis (hydroxyaryl) sulfoxides such as 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfoxide, 4, 4'-dihydroxydiphenyl sulfone, 3,3'-dimethyl-4,4'-
Dihydroxydiphenyl sulfone, 3,3'-diphenyl-4,4'-dihydroxydiphenyl sulfone, 3,
Bis (hydroxyaryl) sulfones such as 3′-dichloro-4,4′-dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) ketone, bis (hydroxyaryl) such as bis (3-methyl-4-hydroxyphenyl) ketone ) Ketones,

Furthermore, 3,3,3 ', 3'-tetramethyl-
6,6'-Dihydroxyspiro (bis) indane ["spirobiindane bisphenol"], 3,3 ', 4,4'-tetrahydro-4,4,4', 4'-tetramethyl-2,2'-
Spirobi (2H-1-benzopyran) -7,7'-diol ["spirobichroman"], trans-2,3-bis (4'-hydroxyphenyl) -2-butene, 9,9-bis (4 ' -Hydroxyphenyl) fluorene, 1,6-bis (4'-hydroxyphenyl) -1,6-hexanedione, α, α, α ', α'-tetramethyl-α, α'-bis (4-hydroxyphenyl) ) -P-xylene, α,
α, α ', α'-tetramethyl-α, α'-bis (4-
Hydroxyphenyl) -m-xylene, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene, 2,7-dihydroxyphenoxathiin, 9,10-dimethyl-2,7-dihydroxyphenazine, 3, , 6-Dihydroxydibenzofuran, 3,6-
Dihydroxydibenzothiophene, 4,4′-dihydroxybiphenyl, 1,4-dihydroxynaphthalene,
2,7-dihydroxypyrene, hydroquinone, resorcin, and the like. An aromatic dihydroxy compound containing an ester bond, which is produced by a reaction of 2 mol of bisphenol A and 1 mol of isophthaloyl chloride or terephthaloyl chloride is also useful. These may be used alone or in combination.

The aliphatic dihydroxy compound is preferably a compound represented by the formula (3) or the formula (4). HO-R-OH (3) HO-R '-Ar 4 -R' -OH (4) ( wherein, R and R 'are each a divalent aliphatic group, Ar ₄ represents a divalent aromatic group In formula (3), R is a divalent aliphatic group, preferably an alkylene group having 2 to 20 carbon atoms and a cycloalkylene group having 4 to 12 carbon atoms. R'is a divalent aliphatic group, preferably an alkylene group having 1 to 6 carbon atoms. Ar ₄ is a divalent aromatic group, preferably a divalent aromatic group having 6 to 12 carbon atoms. Specific examples of the aliphatic dihydroxy compound include ethylene glycol, 1,3-propanediol, 1,4-
Butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1 , 9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, neopentyl glycol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3- Propanediol, 1,3-
Cyclohexanediol, 1,4-cyclohexanediol, 2,2-bis (4′-hydroxycyclohexyl) propane, xylylenediol, 1,4-bis (2′-hydroxyethyl) benzene, 1,4-bis (3 ′) -Hydroxypropyl) benzene, 1,4-bis (4'-hydroxybutyl) benzene, 1,4-bis (5'-hydroxypentyl) benzene, 1,4-bis (6'-hydroxyhexyl) benzene and the like. . These may be used alone or in combination. Moreover, you may use together with an aromatic dihydroxy compound. The dihydroxy compound is more preferably an aromatic dihydroxy compound, and particularly preferably bisphenol A.

The carbonate precursor used as the raw material for the polycarbonate is a diaryl carbonate compound, a dialkyl carbonate compound, an alkylaryl carbonate compound or a carbonyl halide compound, and preferably a carbonyl halide compound. As the carbonyl halide compound, carbonyl chloride called phosgene is usually used. Also useful are carbonyl halide compounds derived from halogens other than chlorine, such as carbonyl bromide, carbonyl iodide and carbonyl fluoride. Further, compounds having an ability to form a haloformate group, for example, trichloromethylchloroformate which is a dimer of phosgene and bis (trichloromethyl) carbonate which is a trimer of phosgene are also useful. These may be used alone or in combination. Usually, the preferred carbonate precursor used is phosgene.

The polycarbonate used in the production method of the present invention includes polyester carbonate. Polyester carbonates are produced, for example, from dihydroxy compounds, carbonate precursors and dibasic acid chlorides. The average molecular weight of the polyester carbonate is not particularly limited, and those having a molecular weight of about 1000 to about 100,000 are usually used. The dihydroxy compound and the carbonate precursor which are the raw materials of the polyester carbonate are the above-mentioned dihydroxy compound and the carbonate precursor.

Examples of the dibasic acid chloride as a raw material for the polyester carbonate include oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid and sebacic acid. Saturated aliphatic dibasic acids, halogen-substituted aliphatic dibasic acids, thioglycolic acid, dithioglycolic acid, etc. Aliphatic dibasic acids containing a hetero atom in the fatty chain, unsaturated aliphatic acids such as maleic acid, fumaric acid, etc. Unsubstituted or aliphatic-substituted aromatic dicarboxylic acids such as dibasic acid, phthalic acid, isophthalic acid, terephthalic acid, homophthalic acid, o-phenylenediacetic acid, m-phenylenediacetic acid, p-phenylenediacetic acid, diphenic acid, It is a chloride of a dibasic acid such as a polycyclic aromatic dicarboxylic acid such as 1,4-naphthalene dicarboxylic acid. These may be used alone or in combination. Particularly preferably used dibasic acid chlorides are chlorides of aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. Further, these polyester carbonates may be used as a mixture with polycarbonate.

The polycarbonate used in the production method of the present invention may be a mixture of other polymers. Specific examples of other polymers include polyethylene, polypropylene, polystyrene, ABS resin, polymethylmethacrylate, polytrifluoroethylene, polytetrafluoroethylene, polyacetal, polyphenylene oxide, polybutylene terephthalate, polyethylene terephthalate, polyamide, polyimide, polyamideimide. , Polyetherimide, polysulfone, polyether sulfone, paraoxybenzoyl-based polyester, polyarylate, polysulfide and the like. These are used with polycarbonate as organic solvent solutions. The content of the other polymer is usually 90% by weight or less based on the polycarbonate, and more preferably 7% by weight or less.
It is 0% by weight or less, and more preferably 50% by weight or less.

In the production method of the present invention, the organic solvent solution of the polycarbonate comprises the polycarbonate, at least one good solvent A for a polycarbonate having a boiling point under atmospheric pressure of less than 100 ° C., and at least one boiling point under the atmospheric pressure. Is a good solvent B for polycarbonate exceeding 100 ° C. The good solvent usually means an organic solvent capable of dissolving about 1% by weight or more of polycarbonate. Solvent A is preferably an organic solvent in which the solubility of polycarbonate is greater than solvent B. The solvent A is more preferably an organic solvent capable of dissolving polycarbonate in an amount of about 5% by weight or more, more preferably about 10% by weight or more, and particularly preferably about 20% by weight or more at room temperature.
The solvent A preferably has a boiling point of about 1 under normal pressure.
The organic solvent has a temperature of 0 to about 90 ° C, more preferably about 20 to about 80 ° C, still more preferably about 30 to about 70 ° C.

Specific examples of the solvent A include dichloromethane, chloroform, 1,2-dichloroethane, 1,2-
Aliphatic chlorinated hydrocarbons such as dichloroethylene, 1,1,1-trichloroethane, dichloropropane, tetrahydrofuran or mixtures thereof. Solvent A
Is more preferably an aliphatic chlorinated hydrocarbon,
Particularly preferred is dichloromethane. The amount of solvent A used is preferably about 1.
5 to about 10 times by weight, and more preferably about 1.8 to
It is about 8 times by weight, and more preferably about 2 to about 6 times by weight.

The solvent B is preferably an organic solvent in which the solubility of the polycarbonate is smaller than that of the solvent A, and more preferably about 1 to about 1 of the polycarbonate at room temperature.
It is an organic solvent that dissolves about 0% by weight. Also, the solvent B
Preferably has a boiling point under atmospheric pressure of about 100 to about 25.
The organic solvent is 0 ° C., more preferably about 110 to about 200 ° C., further preferably about 120 to about 180 ° C.
Specific examples of the solvent B include chlorobenzene, o-, m-
Or aromatic chlorinated hydrocarbon such as p-dichlorobenzene, o-, m- or p-chlorotoluene, o-, m- or p-chloronitrobenzene, alkyl-substituted phenyl ether such as 3-phenoxytoluene, 4-bromo It is a halogen-substituted phenyl ether such as phenyl ether, bromobenzene, anisole, dioxane, phenyl ether or a mixture thereof. The solvent B is more preferably an aromatic chlorinated hydrocarbon, and particularly preferably chlorobenzene.

The amount of the solvent B used is preferably about 0.1 to about 5 times by weight, more preferably about 0.3 to about 3 times by weight, and even more preferably, the amount of the solvent B used. It is about 0.5 to about 2 times by weight. The amount of the solvent A used depends on the amount of the solvent B used, but is preferably about 0.3 to about 20 times by weight the amount of the solvent B, and more preferably about 1 To about 10 times by weight, more preferably about 1.5 to about 8 times by weight, and particularly preferably about 2 to about 7 times by weight. Further, the solvent A and the solvent B may be a recovered organic solvent generated when the polycarbonate granules are manufactured. Further, an organic solvent obtained by mixing the recovered organic solvent and a new organic solvent may be used.

The production method of the present invention can be carried out under any pressure. The pressure is adjusted so that the temperature under the pressure is maintained above the boiling point of solvent A and below the boiling point of solvent B. The temperature at which the production method of the present invention is carried out is higher than the boiling point of the solvent A and lower than the boiling point of the solvent B. Preferably, (boiling point of solvent A)
To (boiling point of solvent B −10 ° C.), more preferably (boiling point of solvent A + 10 ° C.) to (boiling point of solvent B−20 ° C.), and further preferably
(Boiling point of solvent A + 20 ° C) to (Boiling point of solvent B-30 ° C)
Temperature range. For example, when dichloromethane is used as the solvent A and chlorobenzene is used as the solvent B, and the production method of the present invention is carried out under atmospheric pressure, it is about 40 to about 120.
C. is preferred, about 50 to about 110.degree. C. is more preferred, and about 60 to about 100.degree. C. is even more preferred.

In the production method of the present invention, the concentration of the polycarbonate in the organic solvent solution is preferably 7 to 35% by weight, more preferably 10 to 30% by weight, and further preferably 12 to 25% by weight. If the concentration of the polycarbonate in the organic solvent solution is excessively lower than about 7% by weight, the obtained polycarbonate granules will have a low bulk density. Further, when the concentration of the polycarbonate in the organic solvent solution is excessively higher than about 35% by weight, the viscosity of the solution is high and the handling is difficult. By removing at least 90% by weight of the solvent A in the system as described above, the polycarbonate granules of the present invention are obtained. The amount of the solvent A removed during the production of the polycarbonate granules is 90
If the amount is too small, the resulting polycarbonate granules have poor drying properties, and the organic solvent tends to remain.

The polycarbonate granules thus obtained are preferably 1 part with respect to the polycarbonate granules.
It is a polycarbonate granule containing 50 to 50 wt% of solvent B, more preferably 5 to 40 wt%, and particularly preferably 10 to 30 wt% of solvent B. This means that even in the system maintained at a temperature higher than the boiling point of solvent A and lower than the boiling point of solvent B, some amount of solvent B is removed together with solvent A. When the content of the solvent B is excessively less than 1% by weight with respect to the polycarbonate particles during the production of the polycarbonate particles, the subsequent drying property is poor and the organic solvent is likely to remain. The contents of the solvent A and the solvent B in the granular material can be examined by measuring the amounts of the removed solvent A and the solvent B. Specifically, a method of extracting a part of the removed mixture of the solvent A and the solvent B and measuring the mixture by gas chromatography, liquid chromatography, or the like, or
There is a method of separating the solvent A and the solvent B by distilling the mixture and measuring the respective amounts. Further, a method may be used in which a part of the granular material is taken out and the contents of the solvent A and the solvent B in the granular material are measured by gas chromatography or the like.

By the above method, it is possible to preferably produce a polycarbonate granule having a high bulk density and good drying property. A polycarbonate particle having good drying property means that after producing a polycarbonate particle from an organic solvent solution of polycarbonate, the organic solvent is further removed from the obtained particle to obtain a particle substantially containing no organic solvent. Means a particulate material from which the organic solvent can be easily removed.
The polycarbonate granules substantially free of an organic solvent means that the content of the organic solvent is usually about 500 ppm or less, preferably about 200 ppm or less, more preferably about 100 p, based on the weight of the polycarbonate granules.
It means pm or less.

The method for further removing the organic solvent from the polycarbonate granules may be a continuous operation or a batch operation. Specifically, it is carried out under any pressure, at a temperature at which the organic solvent can be removed under that pressure, and by natural drying, or by using an inert gas, steam or the like. In that case, it may be left still and carried out batchwise, or it may be carried out continuously using a conveyor or the like. Further, any stirring device may be used, and in that case, the organic solvent may be removed while further finely pulverizing the polycarbonate granules by the stirring device.

In the production method of the present invention, water, steam and / or an inert gas may be used for carrying out the method. However, it is not necessary to use organic solvents other than the above organic solvents. Even if you use them, there is no particular effect,
It's just wasted. Poor solvent for polycarbonate (organic solvent in which the solubility of polycarbonate is less than about 1% by weight), for example, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and butyl acetate, and aliphatic hydrocarbons such as hexane, heptane, and cyclohexane. Alcohols such as alcohols such as methanol and isopropanol are not particularly effective in the production method of the present invention.

As water, distilled water, ion-exchanged water or a mixture thereof can be used. Further, the recovered water generated during the production of the polycarbonate granules may be used, or the recovered water may be mixed with fresh water and used.
As a method of using water, the water may be present in the system in advance, or may be continuously or intermittently added to the system. Further, a part of water may be allowed to exist in the system in advance, and further water may be added to the system continuously or intermittently. As the steam, steam obtained by heating the above water is used. Water vapor is preferably added continuously to the system. As the inert gas, any gas can be used as long as it is a gas inert to the organic solvent solution of polycarbonate. Such an inert gas is nitrogen gas, argon gas, carbon dioxide, air or the like, and preferably,
It is nitrogen gas. The inert gas may be continuously fed into the system.

Examples of the apparatus used in the production method of the present invention include a kneader, a hand mixer, a paddle mixer, a rotary drum type mixer, a ribbon dryer, a disk dryer, and a stirring device such as a paddle blade, a propeller blade, and a turbine. Stirring tank equipped with simple stirring blades such as blades, lattice blades or paddle blades, Henschel mixer [Mitsui Miike Kakoki Co., Ltd.], Nauta mixer [Hosokawa Micron Co., Ltd.], TURBO SPHERE mixer [Sumitomo Shigeki] Machinery Co., Ltd.], Turbulizer [Hosokawa Micron Co., Ltd.], static mixer, colloid mill, orifice mixer, flow jet mixer, homogenizer, homomixer, mixer, etc.
It is a mixing device or a device in which those devices are arbitrarily combined. Agitation may be such that the polycarbonate granules produced are well mixed. Also, in some cases,
You may stir vigorously. For example, when using a kneader, several tens of rpm, when using a stirring tank, several hundred rp.
About m is sufficient.

The production method of the present invention may be carried out batchwise or continuously. Hereinafter, more specific embodiments of the present invention will be shown. When the production method of the present invention is carried out in a batch system, for example, an organic solvent solution of polycarbonate is put into the system, the pressure is higher than the boiling point of the solvent A under the pressure, and higher than the boiling point of the solvent B. At least 90% by weight of solvent A is removed by heating to a low temperature range and maintaining the temperature range, and the resulting gel-like material is crushed to produce a polycarbonate granule. that time,
Water, steam and / or an inert gas may optionally be used. When water is used, the polycarbonate granules are obtained as a water slurry.

When the production method of the present invention is carried out in a continuous manner, for example, under any pressure, the solvent A under that pressure is used.
The organic solvent solution of the polycarbonate is continuously charged into a system maintained at a temperature higher than the boiling point of the solvent B and lower than the boiling point of the solvent B, and at least 90% by weight of the solvent A is continuously removed. Granules are produced. Also in this case, water, steam and / or an inert gas may be optionally used. When water is used, the polycarbonate granules are obtained as a water slurry. At that time, a small amount of polycarbonate granules may be added to the system in advance. Further, the polycarbonate granules may be continuously taken out of the system by using an apparatus provided with a portion for taking out the obtained polycarbonate granules to the outside of the system to continuously produce the polycarbonate granules.

Further, for example, the production method of the present invention can be continuously carried out by using a mixing device having a plurality of zones. In that case, each zone is maintained at a different temperature at a temperature higher than the boiling point of the solvent A and lower than the boiling point of the solvent B under the pressure, and at least 90% by weight of the solvent A is stepped. To remove it to produce polycarbonate granules. Also in this case, water, steam and / or an inert gas may be optionally used. If water is used, the polycarbonate granules are obtained as a water slurry. At that time, a small amount of polycarbonate granules may be added to the system in advance. Further, the polycarbonate granules may be continuously taken out of the system by using an apparatus provided with a portion for taking out the obtained polycarbonate granules to the outside of the system to continuously produce the polycarbonate granules. By the above operation,
The manufacturing method of the present invention is carried out.

The production method of the present invention may be carried out in the presence of any stabilizer. At that time, the stabilizer may be present in advance in the solution of the polycarbonate in the organic solvent, or may be added at any time. The stabilizer is, for example, a phosphorus-based processing stabilizer, a processing stabilizer such as an antioxidant and a heat stabilizer, and a light resistance stabilizer such as an ultraviolet absorber. For example, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, tristearyl phosphite, triphenyl phosphite, tricresyl phosphite, tris (nonylphenyl) phosphite, tris (2,4- Di-tert-butylphenyl) phosphite, decyl-diphenylphosphite, phenyl-di-2-ethylhexylphosphite, phenyl-didecylphosphite, tricyclohexylphosphite, distearyl-pentaerythrityl-diphosphite, tris (mixed Phosphites such as mono-, di-phenyl) phosphite, octyl- [2,2′-di (4,6-di-tert-butylphenyl) methylenephosphite,

Triethylphosphine, triisopropylphosphine, tri-n-butylphosphine, tricyclohexylphosphine, allyldiphenylphosphine, triphenylphosphine, diphenylphosphine, tris
(2,4-dimethylphenyl) phosphine, tris (2,2
4,6-trimethylphenyl) phosphine, tris (o
-Tolyl) phosphine, tris (o-anisyl) phosphine, diphenylbutylphosphine, diphenyloctadecylphosphine, tris- (p-nonylphenyl) phosphine, tris (naphthyl) phosphine, diphenyl- (hydroxymethyl) phosphine, diphenyl-acetoxymethylphosphine , Diphenyl- (β-ethylcarboxyethyl) phosphine, diphenylbenzylphosphine, diphenyl- (p-hydroxyphenyl) phosphine, diphenyl-1,4-dihydroxyphenyl-
Organic phosphines such as 2-phosphine and phenylnaphthylbenzylphosphine,

Triphenylphosphonite, dinonylphenylphosphonite, diisooctylphenylphosphonite, phenyl (2,4,6-trimethylphenyl) phenylphosphonite, [(3-ethyloxetanyl-3)]
-Methyl]-(2,4,6-trimethylphenyl) phenylphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite and other organic phosphonites, 2,6 -Di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylenebis (6-tert-butyl-p-cresol), 4,4'-methylenebis (6-
tert-butyl-o-cresol), 4,4'-methylenebis (6-tert-butyl-m-cresol), tetrakis- [methylene-3- (3 ', 5'-di-tert-butyl-4'-
Hydroxyphenyl) propionate] methane, 4,4 '
-Thiobis (6-tert-butyl-m-cresol), stearyl-β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6- Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, octadecyl-
3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,5-di-tert-butyl-4
-Phenolic antioxidants such as hydroxybenzylphosphonate-diethyl ester,

2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,
5-bis (α, α-dimethylbenzyl) phenyl] -2
H-benzotriazole, 3 ', 3'-bis [2-
Examples thereof include benzotriazoles such as (5′-octyl-2′-hydroxyphenyl) benzotriazolyl] methane. These may be used alone or in combination. The amount of the stabilizer used may be any amount that exhibits a stabilizing effect. The amount used varies slightly depending on each stabilizer,
About 0.1 ppm to about 500 with respect to polycarbonate
0 ppm is preferred. In addition to the above stabilizers, any additive may be added before, during, or after the production of the polycarbonate granules. As an additive,
Pigments, dyes, hydrolysis stabilizers, impact stabilizers, release agents,
Organic halogen compounds, alkali metal sulfonates, glass fibers, carbon fibers, glass beads, barium sulfate, Ti
Examples include O _{2 and the} like.

The aromatic polycarbonate granules produced by the method of the present invention can be used alone or as a molding material by mixing with other polymers. Specific examples of other polymers include polyethylene, polypropylene, polystyrene, ABS resin, polymethylmethacrylate, polytrifluoroethylene, polytetrafluoroethylene, polyacetal, polyphenylene oxide, polybutylene terephthalate, polyethylene terephthalate,
Examples thereof include polyamide, polyimide, polyamideimide, polyetherimide, polysulfone, polyethersulfone, paraoxybenzoyl-based polyester, polyarylate, and polysulfide.

The polycarbonate granules produced by the method of the present invention are soluble in a specific organic solvent (for example, a halogenated hydrocarbon solvent such as dichloromethane), and can be molded into a film from the organic solvent solution. It can be processed into a product. The polycarbonate granules produced by the method of the present invention are thermoplastic and can be easily molded from a melt by a known molding method such as injection molding, extrusion molding, blow molding, or lamination. In addition, the polycarbonate granules produced by the method of the present invention may be added alone or in a state of being mixed with another polymer, if desired, by adding the above-mentioned stabilizer or additive to a chassis or housing material of electric equipment or the like. , Electronic parts, automobile parts, building materials instead of glass, information recording medium bases such as data storage disks or audio compact disks, and optical materials such as lenses of cameras or spectacles.

[0042]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. Polymerization Example 1 A 10-liter baffled flask was equipped with a three-stage six-blade stirrer and a reflux condenser. In this flask, 912 g of bisphenol A (4.0 mol), p-te
20.7 g of rt-butylphenol (3.44 mol% with respect to bisphenol A), 5320 g of dichloromethane and 4 liters of water were added, and a nitrogen purge was performed to remove oxygen in the flask. Next, 1.5 liter of an aqueous solution of 1.8 g of sodium hydrosulfite and 436 g (10.91 mol) of sodium hydroxide was supplied to the above suspension, and bisphenol A was dissolved at 15 ° C. With stirring, 467 g (4.72 mol) of phosgene was fed to this mixture in 30 minutes. After that, triethylamine 0.3
The reaction was terminated by adding 2 g (0.08 mol% to bisphenol A) and stirring for 60 minutes. Then, the reaction mixture was allowed to stand, the organic phase was separated, neutralized with hydrochloric acid, and repeatedly washed with water until the electrolyte was exhausted. The weight average molecular weight of the obtained polycarbonate was 5,1800.
Met. Using the thus obtained polycarbonate solution of polycarbonate, an organic solvent solution of polycarbonate was prepared according to the following Examples and Comparative Examples.

Example 1 633.6 g of a solution of polycarbonate in dichloromethane
Was placed in a 2 liter flask equipped with a paddle blade, and 433.2 g of dichloromethane and 457.2 g of chlorobenzene were added to make 1524 g (101.6 g of polycarbonate, 965.2 g of dichloromethane, 457.2 g of chlorobenzene), and an organic solvent of polycarbonate. The solution was adjusted. The flask was heated to 120 ° C. and stirred at 200 rpm for 120 minutes while removing the organic solvent to obtain polycarbonate granules. Next, the obtained polycarbonate granules are treated at 120 ° C. at 30-40 mmH.
It was dried at 6 g for 6 hours.

Example 2 A 1 liter flask was equipped with paddle blades. In a flask, add the polycarbonate solution 6 in dichloromethane.
33.6 g (101.6 g of polycarbonate, 532 g of dichloromethane) was put, 100 g of dichloromethane and 224 g of chlorobenzene were added, and the organic solvent solution of polycarbonate was adjusted. Heat the flask to 45 ° C,
While removing the organic solvent, the mixture was stirred at 200 rpm for 120 minutes to obtain polycarbonate granules. Next, the obtained polycarbonate granules were heated at 120 ° C. for 30 to 40 mm.
It was dried in Hg for 6 hours.

Example 3 125.6 g of dichloromethane was removed from 633.6 g of a dichloromethane solution of polycarbonate to obtain 508 g (101.6 g of polycarbonate, 406.
4g). This dichloromethane solution was put into a 1 liter flask equipped with a paddle blade, and 60 g of chlorobenzene was further added to prepare an organic solvent solution of polycarbonate. The flask was heated to 55 ° C. and stirred at 200 rpm for 60 minutes while removing the organic solvent to obtain polycarbonate granules. Next, the obtained polycarbonate granules were dried at 120 ° C. and 30 to 40 mmHg for 6 hours.

Example 4 125.6 g of dichloromethane was removed from 633.6 g of a solution of polycarbonate in dichloromethane to give 508 g (101.6 g of polycarbonate, 406.
4g), and further add 63.4g of chlorobenzene,
An organic solvent solution of polycarbonate was prepared. This organic solvent solution was continuously added to a 1 liter flask equipped with a paddle blade and maintained at 110 ° C. under stirring at 200 rpm to continuously obtain polycarbonate granules. At that time, simultaneously with the addition of the organic solvent solution, nitrogen gas was supplied to the flask, and the addition of the organic solvent solution was completed in 60 minutes. Next, the obtained polycarbonate granules,
Approx. 120 ° C, approx. 200r while continuing to supply nitrogen gas
It was stirred at pm and dried for 6 hours with further grinding.

Example 5 125.6 g of dichloromethane was removed from 633.6 g of a solution of polycarbonate in dichloromethane to give 508 g (101.6 g of polycarbonate, 406.
4 g), and 101.6 g of o-dichlorobenzene
And tris (nonylphenyl) phosphite 30mg
(300 ppm with respect to polycarbonate) was added to prepare an organic solvent solution of polycarbonate. This organic solvent solution was continuously added to a 1 liter flask equipped with a paddle blade, which was maintained at 70 ° C. under stirring at 200 rpm, to continuously obtain polycarbonate granules. At that time, 200 g of water was previously put in the flask, and the addition of the organic solvent solution was completed in 60 minutes. next,
The obtained polycarbonate granules were heated at 120 ° C at 30-
It was dried at 40 mmHg for 6 hours.

Example 6 125.6 g of dichloromethane was removed from 633.6 g of a solution of polycarbonate in dichloromethane to give 508 g (101.6 g of polycarbonate, 406.
4 g) and further o-chloronitrobenzene 101.
6 g and tris (nonylphenyl) phosphite 30
mg (300 ppm with respect to polycarbonate) was added to prepare an organic solvent solution of polycarbonate. This organic solvent solution was continuously added to a 0.5 liter flask equipped with a paddle blade and equipped with an outlet at the bottom, which was maintained at 75 ° C. under stirring at 200 rpm, to continuously add polycarbonate particles. Got to. At that time, steam of about 100 ° C. was supplied to the flask at the same time as the addition of the organic solvent solution, 10 g of the polycarbonate granules were placed in advance in the flask, and 15 g of the polycarbonate granules were placed every 10 minutes from the bottom outlet. The sample was taken out, and the addition of the organic solvent solution was completed in 60 minutes. Next, the obtained polycarbonate granules are treated at 120 ° C. and 30 to 40 mmHg.
And dried for 6 hours.

Example 7 293.6 g of dichloromethane was removed from 633.6 g of a dichloromethane solution of polycarbonate, and 340 g (101.6 g of polycarbonate, 238.
4 g), and 152.4 g of chlorobenzene was further added to prepare an organic solvent solution of polycarbonate. This organic solvent solution was placed in a 1-liter twin-screw kneader equipped with a distillation tube for organic solvent, which was maintained at 80 ° C. While removing the organic solvent, stirring is performed at 50 rpm for 40 minutes,
A polycarbonate granule was obtained. Meanwhile, nitrogen gas was continuously supplied to the flask. Next, the obtained polycarbonate granules were dried at 120 ° C. and 30 to 40 mmHg for 6 hours.

Example 8 125.6 g of dichloromethane was removed from 633.6 g of a dichloromethane solution of polycarbonate, and 508 g (polycarbonate 101.6 g, dichloromethane 406.
4 g), and 67.0 g of ABS resin [270 g (dichloromethane 202.3 g) of a dichloromethane solution of Santac UT-61B, manufactured by Mitsui Toatsu Chemicals, Inc.) and 169 g of chlorobenzene were added thereto, and an organic solvent solution of polycarbonate was added. It was adjusted. This organic solvent solution was placed in a 1 liter flask equipped with a paddle blade, and
200 rpm while heating to 0 ℃ and removing the organic solvent
And stirred for 60 minutes to obtain a polycarbonate granule. Next, the obtained polycarbonate granules were heated at 120 ° C. for 3
It was dried at 0 to 40 mmHg for 6 hours.

Example 9 293.6 g of dichloromethane was removed from 633.6 g of a dichloromethane solution of polycarbonate, and 340 g (polycarbonate 101.6 g, dichloromethane 238.
4 g), and 101.6 g of chlorobenzene was further added to prepare an organic solvent solution of polycarbonate. The organic solvent solution was placed in a 1 liter flask equipped with a paddle blade. The flask was heated to 80 ° C. and stirred at 200 rpm for 40 minutes while removing the organic solvent,
A polycarbonate granule was obtained. Next, the obtained polycarbonate granules were dried at 120 ° C. and 30 to 40 mmHg for 6 hours.

Comparative Example 1 (method described in Japanese Patent Publication No. 36-21033) 633.6 g of a polycarbonate solution in dichloromethane
(Polycarbonate 101.6 g, dichloromethane 53
2 g) was placed in a 4 liter flask fitted with paddle blades, heated to about 42 ° C. and 12 at about 200 rpm.
After stirring for 0 minutes, a gel was obtained. Next, this gel-like material was pulverized to obtain a polycarbonate granular material. Then add 3.5 liters of water, about 40 to about 4
It heated at 5 degreeC and the organic solvent was removed over 6 hours. At this point, the residual amount of dichloromethane in the polycarbonate granules was measured and found to be 7200 ppm relative to the polycarbonate granules, so the obtained polycarbonate granules were further heated at 120 ° C. and 30-40 mmHg for 6 hours. Dried.

Comparative Example 2 (Method described in Japanese Patent Publication No. 36-21033) 633.6 g of a solution of polycarbonate in dichloromethane
Was placed in a 4 liter flask fitted with paddle blades, then 406.4 g of o-dichlorobenzene was added and heated to about 40 to about 45 ° C. to remove dichloromethane, 508 g (101.6 g of polycarbonate, o- Dichlorobenzene 406.4 g) was used to obtain an organic solvent solution of polycarbonate. Then, the mixture was heated to about 80 ° C. with stirring at about 200 rpm, 3.5 liters of water was added, and then cooled to give a gel. Next, this gel-like material was pulverized to obtain a polycarbonate granular material. Then, at about 45 to about 75 ° C. and 40 to 80 mmHg, 6
The organic solvent was removed over time. The residual amount of o-dichlorobenzene in the polycarbonate granules at this time was measured, and it was found to be 1 for the polycarbonate granules.
Since it was 3.6% by weight, the obtained polycarbonate granules were further mixed at 120 ° C. and 30 to 40 mmHg for 6%.
Dried for hours.

Comparative Example 3 125.6 g of dichloromethane was removed from 633.6 g of a solution of polycarbonate in dichloromethane to give 508 g (101.6 g of polycarbonate, 406.
4g). This organic solvent solution was put into a 1 liter flask equipped with a paddle blade, and 101.6 g of chlorobenzene was further added to prepare an organic solvent solution of polycarbonate. Heat the flask to 35 ° C., 200
After stirring at rpm for 120 minutes, the organic solvent was not removed and no polycarbonate granules were obtained.

Comparative Example 4 125.6 g of dichloromethane was removed from 633.6 g of an organic solvent solution of polycarbonate to obtain 508 g (101.6 g of polycarbonate, 406.4 of dichloromethane).
g). This organic solvent solution was put into a 1 liter flask equipped with a paddle blade, and 101.6 g of chlorobenzene was further added to prepare an organic solvent solution of polycarbonate. The flask was heated to 150 ° C. and stirred at 200 rpm for 10 minutes while removing the organic solvent to obtain polycarbonate granules. Next, the obtained polycarbonate granules were dried at 120 ° C. and 30 to 40 mmHg for 6 hours.

In Table 1 (Table 1), the concentration (% by weight) of the polycarbonate in the organic solvent solution of the polycarbonate and the amount of the solvent A (weight times, based on the weight of the polycarbonate) in each Example and each Comparative Example are shown. ) And the amount of solvent B used (weight times, relative to the weight of the polycarbonate),
The temperature in the system during the production of the granules is shown. Table 2 (Table 2) shows the residual amount of solvent A (% by weight, based on the weight of the polycarbonate granular substance) and the residual amount of solvent B in the polycarbonate granules before drying in each Example and each Comparative Example. (% By weight, based on the weight of the polycarbonate granules), the content of solvent A (ppm, based on the weight of the polycarbonate granules) in the dried polycarbonate granules, and the content of solvent B (ppm, the polycarbonate granules) (Relative to the weight of the body), and the bulk density of the polycarbonate granules. The measuring method is as shown below. Content of solvent in polycarbonate granules: Measured by gas chromatography (Shimadzu Corporation GC-9A) using 10 mg of polycarbonate granules. Bulk density: The bulk density of the polycarbonate granules was measured according to the method of JIS R-6126.

[0057]

[Table 1] PC: Polycarbonate

[0058]

[Table 2] From the above results, it can be seen that the production method of the present invention can favorably produce polycarbonate granules having high bulk density and good drying property.

[0059]

According to the present invention, it becomes possible to provide a polycarbonate granule having a high bulk density and good drying property.

(72) Inventor Masakatsu Nakatsuka 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Akihiro Yamaguchi 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (5)

[Claims] 1. A method for producing polycarbonate granules from a solution of polycarbonate in an organic solvent, wherein the polycarbonate and at least one of them have a boiling point of 10 at normal pressure.
From an organic solvent solution of a polycarbonate containing a good solvent A for a polycarbonate below 0 ° C. and at least one good solvent B for a polycarbonate having a boiling point under normal pressure of more than 100 ° C., which is higher than the boiling point of the solvent A and a solvent B. At least 90% by weight of the solvent A is removed at a temperature lower than the boiling point of to obtain a polycarbonate granule. 2. The method for producing polycarbonate granules according to claim 1, wherein the concentration of the polycarbonate in the organic solvent solution is 7 to 35% by weight. 3. The method for producing a polycarbonate granule according to claim 1, wherein the polycarbonate granule contains 1 to 50% by weight of the solvent B with respect to the granule. 4. The method for producing a polycarbonate granular material according to claim 1, wherein water, steam and / or an inert gas are used. 5. The method for producing a polycarbonate granule according to any one of claims 1 to 4, wherein an organic solvent is further removed from the polycarbonate granule to obtain a granule containing substantially no organic solvent.