JP3155796B2 - Process for producing granules of polycarbonate and its composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing granules of polycarbonate. More specifically, the present invention relates to a method for producing a granular material of polycarbonate having a high bulk density from an organic solvent solution of polycarbonate and easy to handle, and more specifically, having a large particle size, substantially free from fine powder, The present invention relates to a method for producing excellent polycarbonate granules. The present invention also relates to a method for producing granules of a polycarbonate composition, and more particularly to a method for producing granules of a polycarbonate composition comprising a polycarbonate and at least one stabilizer, and more specifically, pellets The present invention relates to a method for producing a granular body of a polycarbonate composition which can be directly molded and processed without going through a forming step.

[0002]

2. Description of the Related Art Various methods for producing polycarbonate from a solution of polycarbonate in an organic solvent have been conventionally proposed. For example, a method of concentrating and crystallizing a solution of a polycarbonate in an organic solvent and pulverizing the solution (Japanese Patent Publication No. 38-224)
No. 97), but this method is not industrially efficient because it takes a long time to obtain a pulverizable crystallization state. Methanol (Japanese Patent Publication No. 3622447), a solution of polycarbonate in an organic solvent,
There is also a method in which acetone, ethyl acetate or the like (Japanese Patent Publication No. 37-7000) is added to precipitate polycarbonate. However, the polycarbonate obtained by these methods is a fine powder having a low bulk density. Furthermore, a method of obtaining a polycarbonate by heating an organic solvent solution of polycarbonate in an aqueous medium and evaporating and removing the organic solvent has been proposed (U.S. Pat. No. 3,505,273). According to this method, it is necessary to perform sufficient stirring in order to form a sticky mass.

[0003] Some improved methods for preventing the formation of lumps in an aqueous medium have also been proposed. For example, a method of spraying an organic solvent solution of polycarbonate into warm water using a spray nozzle (US Pat.
No. 07), a dichloromethane solution of polycarbonate is supplied to a granulation tank, and the suspension is kept in water for 1.1 to 50 minutes.
A method of evaporating dichloromethane under atmospheric pressure (Japanese Patent Application Laid-Open No. Sho 60-116412), a method of continuously supplying a dichloromethane solution of polycarbonate to warm water in a granulation tank to form polycarbonate granules, Of at least a part of a water slurry containing a solution and circulating it in a granulation tank (JP-A-59-133).
No. 228), a method in which a dichloromethane solution of polycarbonate is supplied to a kneader having a pulverizing mechanism in which hot water maintained at a temperature equal to or higher than the boiling point of dichloromethane and having a pulverizing mechanism is mixed and kneaded to simultaneously remove solvent and pulverize ( Japanese Patent Application Laid-Open No. Sho 60-202126), in which polycarbonate granules are present in warm water, a narrow flow path is provided in the hot water stirring flow, and the stirring blades are rotated at high speed in this flow path to reduce the shearing force. There is a method in which hot water is convected at a high speed while applying, and a dichloromethane solution of polycarbonate is supplied into the hot water to granulate (Japanese Patent Laid-Open No. 1-74231). However, any of these methods requires high-pressure conditions and special devices and conditions such as a wet pulverizer and a kneader, and a method for more easily producing polycarbonate granules has been desired.

On the other hand, a method of obtaining a polycarbonate by adding an anti-solvent to a polycarbonate such as methyl ethyl ketone and methyl isobutyl ketone and water to a solution of the polycarbonate in an organic solvent and heating the solvent to evaporate the organic solvent (US (Patent No. 4,668,768)
Although it is also known, the polycarbonate obtained by this method contains fine powder, which may cause the fine powder to be scattered during storage, bag collection, molding, or bridging in the hopper of an extruder during molding. There was a problem in scattering and fluidity during handling, for example, when it occurred.

As a method for obtaining a polycarbonate having a larger particle size, a lower alkyl-substituted benzene is added as a swelling agent for the polycarbonate to a solution of the polycarbonate in an organic solvent, and most of the organic solvent is evaporated to form a gel. Of a porous material by granulating the hydride and evaporating the remaining organic solvent and swelling agent (JP-B-46-31468), adding a solidifying solvent to an organic solvent solution of polycarbonate and mixing. In the method of producing an aqueous slurry of polycarbonate by distilling off the organic solvent and the solvent for solidification while supplying the mixed solution to warm water under heating, the liquid in the solidification process is circulated through a wet pulverizer while the solid is solidified. (Japanese Patent Application Laid-Open No. 61-250026), an organic solvent solution of polycarbonate in water in which particles of polycarbonate are suspended In addition, a method of the organic solvent was distilled off to obtain the granules of polycarbonate (U.S. Pat. No. 4,60
3, No. 194). In the method for producing porous granular material disclosed in JP-B-46-31468, a rice cake is formed during the solidification process, and this must be crushed by stirring. Can be difficult. In addition, the method disclosed in Japanese Patent Application Laid-Open No. 61-250026 requires a special granulation tank equipped with a wet pulverizer, and furthermore, a solidifying solvent is added to the organic solvent solution of polycarbonate to be supplied. In some cases, the precipitation of polycarbonate occurs during the process, making it impossible to smoothly supply the organic solvent solution of polycarbonate. Further, although the method of U.S. Pat. No. 4,603,194 can obtain polycarbonate particles containing almost no fine powder, it is necessary to reduce the amount of polycarbonate particles in order to obtain polycarbonate particles having a uniform particle size. It is necessary to strictly control the supply rate of the organic solvent solution of polycarbonate or polycarbonate and the distillation rate of the organic solvent, and often a lump is formed.

[0006]

SUMMARY OF THE INVENTION The present invention relates to storage,
Excellent handling and handling during molding, substantially free of fine powder, large particle size, high bulk density, excellent properties of polycarbonate granules, using a special device from polycarbonate organic solvent It is intended to efficiently manufacture without any. Another object of the present invention is to produce a polycarbonate granule that can be directly molded without performing processing such as pelletization, and more specifically, a polycarbonate that can mold a polycarbonate having an excellent color tone. To produce granules.

[0007]

The present inventors have conducted intensive studies to efficiently produce granules of polycarbonate having good properties, and as a result, surprisingly, water was added to a poor solvent for polycarbonate. By adding a polycarbonate powder to the suspension mixture, and supplying an organic solvent solution of polycarbonate to the suspension mixture, by a very simple operation of distilling off the organic solvent, substantially no fine powder, The present inventors have found that polycarbonate granules having a uniform particle size, an average particle size of about 1 to 4 mm, and a bulk density of about 0.3 to 0.6 g / ml, which are extremely excellent in handleability, are obtained. That is, the present invention relates to water and the amount of water.
A poor solvent for polycarbonate having a volume ratio of 0.05 to 1.5 times and an organic solvent solution of polycarbonate
0.5 to 50% by weight based on the amount of polycarbonate in
The suspension mixture consisting of an amount ranging polycarbonate powder, under stirring, while supplying the organic solvent solution of the polycarbonate, the organic solvent of polycarbonate was distilled off, granular polycarbonate consists in forming the granulate It provides a method for the production of the body, and also water and the amount of water
A poor solvent for polycarbonate having a volume ratio of 0.05 to 1.5 times, and an organic solvent for polycarbonate.
0.5 to 50 based on the amount of polycarbonate in the medium solution.
The organic solvent of the polycarbonate is evaporated and distilled off while supplying the organic solvent solution of the polycarbonate to the suspension mixture composed of the polycarbonate powder in the range of weight% in the presence of the stabilizing agent while stirring. An object of the present invention is to provide a method for producing granules of a polycarbonate composition comprising a polycarbonate for forming a body and at least one stabilizer.

The polycarbonate used in the present invention may be either an aliphatic polycarbonate or an aromatic polycarbonate, but preferably an aromatic polycarbonate is used. Aromatic polycarbonates are usually prepared in a well-known manner, for example from a dihydroxyaromatic compound and phosgene or the bischloroformate of the dihydroxyaromatic compound. Although there is no particular limitation on the average molecular weight of the polycarbonate, usually, the average molecular weight of 1000 to 50000
Of these are preferably used. Examples of the dihydroxy aromatic compound used as a raw material of the aromatic polycarbonate include a dihydroxy aromatic compound represented by the following formula.

HO-Ar ¹ -X-Ar ² -OH wherein Ar ¹ and Ar ² are each a divalent monocyclic aromatic group;
X is a group linking Ar ¹ and Ar ² . Ar ¹ and Ar ²
May be an unsubstituted phenylene group or a substituted phenylene group. Examples of the substituent include a hydrocarbon group such as an alkyl group, a cycloalkyl group, an alkenyl group, and an aryl group, a halogen, a nitro group, and an alkoxy group. Preferably, both Ar ¹ and Ar ² are p-phenylene groups, but both may be o- or m-phenylene, or one may be o- or m-phenyl.
It may be phenylene. X is usually a single bond or a divalent hydrocarbon group, and further includes a group containing atoms other than carbon and hydrogen, for example, -O-, -S-, -SO-,-
It may be SO ₂ — or —CO—. A divalent hydrocarbon group is a saturated hydrocarbon group such as methylene, ethylene,
Examples include alkylidene groups such as 2,2-propylidene and cyclohexylidene, and also include groups substituted with an aryl group and the like, and hydrocarbon groups containing an aromatic group or other unsaturated hydrocarbon group. It may be.

Specific examples of the dihydroxy aromatic compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4'-hydroxyphenyl) ethane, 1,2-bis (4'-hydroxyphenyl) ethane, Bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) -1-naphthylmethane, 1,1-bis (4′-hydroxyphenyl) -1-phenylethane, 2,2-bis (4'-hydroxyphenyl) propane ["bisphenol A"], 2- (4'-
Hydroxyphenyl) -2- (3′-hydroxyphenyl) propane, 2,2-bis (4′-hydroxyphenyl) butane,
1,1-bis (4'-hydroxyphenyl) isobutane, 2,2-
Bis (4'-hydroxyphenyl) octane, 2,2-bis (3'-methyl-4'-hydroxyphenyl) propane,
2-bis (3'-ethyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-n-propyl-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'-methoxy-4'-hydroxyphenyl) propane, 2,2-bis (3 ', 5'-dimethyl-4'-hydroxyphenyl) propane, 2,2-bis (2', 3 ' , 5 ', 6'-tetramethyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-
Chloro-4'-hydroxyphenyl) propane, 2,2-bis (3 ', 5'-dichloro-4'-hydroxyphenyl) propane, 2,2-bis (3'-bromo-4'-hydroxyphenyl)
Propane, 2,2-bis (3 ′, 5′-dibromo-4′-hydroxyphenyl) propane, 2,2-bis (2 ′, 6′-dibromo-3 ′,
5'-dimethyl-4'-hydroxyphenyl) propane, bis (4-hydroxyphenyl) cyanomethane, 1-cyano
Bis (hydroxyaryl) alkanes such as -3,3-bis (4′-hydroxyphenyl) butane and 2,2-bis (4′-hydroxyphenyl) hexafluoropropane;

1,1-bis (4'-hydroxyphenyl) cyclopentane, 1,1-bis (4'-hydroxyphenyl) cyclohexane, 1,1-bis (4'-hydroxyphenyl) cycloheptane, 2,2 Bis (hydroxyaryl) cycloalkanes such as -bis (4'-hydroxyphenyl) adamantane, 4,4'-dihydroxydiphenyl ether, 4,4'-
Dihydroxy diaryl ethers such as dihydroxy-3,3'-dimethyldiphenyl ether and ethylene glycol bis (4-hydroxyphenyl) ether; 4,4'-dihydroxydiphenyl sulfide; and 4,4'-dihydroxy-
Dihydroxydiarylsulfides such as 3,3'-dimethyldiphenylsulfide, 4,4'-dihydroxydiphenylsulfoxide, 4,4'-dihydroxy-3,3'-dihydroxydiarylsulfoxides such as dimethyldiphenylsulfoxide, 4,4'- Dihydroxydiphenyl sulfone, 4,
Dihydroxydiarylsulfones such as 4'-dihydroxy-3,3'-dimethyldiphenylsulfone, bis (4-hydroxyphenyl) ketone, bis (4-hydroxy-3-
Bis (hydroxyaryl) ketones such as methylphenyl) ketone;

Further, 5,6'-dihydroxy-3,3,3 ', 3'-
Tetramethylspiro (bis) indane ["spirobiindanebisphenol"], trans-2,3-bis (4'-hydroxyphenyl) -2-butene, 9,9-bis (4'-hydroxyphenyl) fluorene, 3 , 3-Bis (4'-hydroxyphenyl) -2-butanone, 1,6-bis (4'-hydroxyphenyl) -1,6-hexanedione, 1,1-dichloro-2,2-bis (4 ' -Hydroxyphenyl) ethylene, 1,1-dibromo
-2,2-bis (4'-hydroxyphenyl) ethylene, 1,1-
Dichloro-2,2-bis (5'-phenoxy-4'-hydroxyphenyl) ethylene, α, α, α ', α'-tetramethyl-α, α'-bis (4-hydroxyphenyl) -p-xylene , Α, α, α ', α'-tetramethyl-α, α'
-Bis (4-hydroxyphenyl) -m-xylene, 4,4 '
-Dihydroxydiphenyl and the like. . In addition to the above-mentioned dihydroxy aromatic compounds, hydroquinone, resorcin and the like are also used. These may be used alone or in combination of two or more. In the present invention,
Particularly preferably used dihydroxy aromatic compounds,
Bisphenol A.

An organic solvent solution of the polycarbonate of the present invention (hereinafter abbreviated as polycarbonate solution)
What may be prepared by dissolving polycarbonate in an organic solvent, and the conventional polycarbonate production method,
That is, the interfacial polymerization method (Interscience Publishing, "Encycl
opedia of Polymer Science and Technology ", vol.10, p
olycarbonate, p.710-764, (1969), H.Schnell, ”Chem
istry and Physics of Polycarbonate ", Interscience P
ublishing, pp. 33-41, (1964)), in the presence of an organic solvent that dissolves polycarbonate, a small amount of a molecular weight regulator and, if desired, a branching agent to convert a dihydroxy aromatic compound into phosgene or dihydroxy aromatic. A polycarbonate homopolymer or copolymer solution obtained by reacting the compound with a bischloroformate composition or a solution obtained by appropriately concentrating the solution or a solution prepared by other methods may be used. The organic solvent used as the solvent for the polycarbonate solution can be arbitrarily used as long as it dissolves polycarbonate.For example, chlorinated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, and 1,2-dichloroethylene or Mixtures thereof are preferred. In the present invention,
It is particularly preferred to use dichloromethane, which has a low boiling point and dissolves polycarbonate well. The concentration of the polycarbonate in the polycarbonate solution may take any concentration up to the saturation concentration. However, those with too high a concentration have high viscosity and are difficult to handle.
The concentration is preferably about 5 to 35% by weight.

[0015] A poor solvent for polycarbonate (hereinafter abbreviated as a poor solvent) is a solvent (anti-solvent) having the ability to precipitate polycarbonate without removing the organic solvent when a sufficient amount is added to the polycarbonate solution. Unlike non-solvents, which do not affect the solubility of the polycarbonate even when added in large amounts. Specific examples of the poor solvent include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, aliphatic hydrocarbons such as n-hexane and n-heptane, methyl cyclohexane, cyclohexane and the like. Alicyclic hydrocarbons, alcohols such as methanol and isopropanol, and nitromethane, acetonitrile, ethylene carbonate, tetrahydrofuran, dioxane, and mixtures thereof.

A feature of the present invention is to obtain substantially spherical polycarbonate particles having a uniform particle size and a high bulk density. For this purpose, preferred poor solvents include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone. And esters such as ethyl acetate and butyl acetate. It is another feature of the present invention that these poor solvents are mixed not with the polycarbonate solution but with a suspension of water and polycarbonate powder. It is known to add a poor solvent to a polycarbonate solution in advance and supply it to warm water or the like to produce a solid polycarbonate. However, according to this method, various factors such as an outside air temperature cause the polycarbonate solution to be heated or the like. In some cases, polycarbonate in the polycarbonate solution was precipitated while the solution was being supplied to or fed from the reactor, which caused inconvenience in operation. In the initial stage of supplying the polycarbonate solution,
Since almost no poor solvent is present in an aqueous medium such as warm water, a lump of polycarbonate is generated in the initial stage of supply, and the poor solvent in the sequentially supplied polycarbonate solution has a difference in boiling point from the organic solvent. Due to the accumulation in the aqueous medium, the amount of the poor solvent in the aqueous medium finally becomes a predetermined amount, the precipitation of polycarbonate in the organic solvent remaining in the aqueous medium and the lump formed in the early stage of the supply of the polycarbonate solution Shattering of the object occurs.

That is, the method of adding a poor solvent to a polycarbonate solution cannot completely suppress the production of fine powder of polycarbonate. According to the method of the present invention, since the poor solvent is added to the aqueous medium in advance, the above-mentioned situation does not occur, and polycarbonate granules substantially containing no fine powder can be obtained. Further, adding the poor solvent to the aqueous medium in advance has an effect of uniformly dispersing the polycarbonate powder, which is one of the components of the present invention described later, in water. The polycarbonate powder becomes a seed crystal for producing the polycarbonate granules, but if it is not uniformly dispersed in the aqueous medium, the effect is extremely low. Because polycarbonate has almost no compatibility with water, simply adding polycarbonate powder to water causes it to aggregate or spread out on the water surface.In this state, even mixing is not performed unless strong stirring is performed. The state of dispersion cannot be maintained. However, by adding a predetermined amount of a poor solvent to water, the polycarbonate powder can be evenly dispersed and maintained in the state even with extremely weak stirring. The amount of poor solvent used is
The volume ratio is preferably 0.05 to 1.5 times, more preferably 0.1 to 1 time, based on the volume of water used. 0.05 poor solvent
If the ratio is less than twice, the uniformity of the particle size becomes poor, and there is a tendency that a lump is easily formed. On the other hand, if the amount of the poor solvent is more than 1.5 times, it is not preferable because the produced polycarbonate granules have low bulk density and are close to fine powders.

The amount of water used may be 0.5 times or more by volume ratio to the amount of the polycarbonate solution to be used, but is preferably 0.5 to 3 times by volume ratio. If the amount of water used is less than 0.5 times, agglomerated polycarbonate may be formed and stirring of the slurry may be difficult, which is not preferable. As long as the relationship between the amount of water and the poor solvent is within the above-mentioned range, the amount of water relative to the polycarbonate solution is not inconvenient from the viewpoint of the properties of the produced polycarbonate granules even when used in large amounts. However, using a large amount of water requires a large apparatus, increases the amount of a poor solvent to be used, and deteriorates the thermal efficiency.

The polycarbonate powder dispersed in a mixed solution of water and a poor solvent is a seed crystal for producing polycarbonate granules. There are no particular restrictions on the particle size and particle size distribution, but the average particle size is 0.1-1.
It is preferably a polycarbonate powder of mm. A portion of the polycarbonate granules produced by the method of the present invention may be crushed and suspended. The amount of the polycarbonate powder to be dispersed may be 0.5% by weight or more based on the amount of the polycarbonate in the polycarbonate solution, but is preferably 0.5 to 50% by weight, particularly preferably 3 to 30% by weight. . When the amount of the polycarbonate powder to be dispersed is less than 0.5% by weight, a lump of polycarbonate is generated, and it is difficult to obtain polycarbonate granules having uniform properties. In addition, the fact that the amount of the polycarbonate powder to be dispersed is large is not particularly inconvenient in terms of the properties of the polycarbonate granules to be produced, but is disadvantageous in terms of productivity.

The method of supplying the polycarbonate solution to the suspension mixture of water, the poor solvent and the polycarbonate powder may be, for example, a supply means such as dropping, but may be any other method. Also, the rate of supplying the polycarbonate solution may be as fast as possible, but the amount of the organic solvent in the supplied polycarbonate solution is determined by the amount of the organic solvent evaporated and distilled while supplying the polycarbonate solution. On the other hand, it is preferably about 1 to 10 times by volume, and more preferably about 1 to 5 times by volume.
In general, it is preferable to supply the entire amount of the supplied polycarbonate solution in about 0.1 to 3 hours, depending on the method of evaporating and removing the organic solvent described below, the heating temperature, and the like.
Obviously, supplying over a long period of time is not preferable in terms of productivity.

The method of evaporating and removing the organic solvent is not only a method of evaporating and distilling by ordinary heating, but also a method of evaporating and distilling the organic solvent by heating while flowing an inert gas such as nitrogen or a method of evaporating under reduced pressure. A method of distilling off is used. Normally, the suspension mixture of water, poor solvent and polycarbonate powder is kept heated while the polycarbonate solution is supplied and the organic solvent is evaporated off. The heating temperature may be equal to or lower than the boiling point of the organic solvent of the polycarbonate, but if it is significantly low, the evaporation rate of the organic solvent becomes slow and a large amount of the organic solvent remains in the suspension mixture. An object or a lump is formed, and it is difficult to obtain a polycarbonate granular material of uniform quality, which is not preferable. On the other hand, if the heating temperature is too high, it is not preferable because the poor solvent and water in the suspension mixture are evaporated off. Therefore, in the method of the present invention, the heating temperature of the suspension mixture is preferably a temperature equal to or higher than the boiling point of the organic solvent of the polycarbonate,
It is more preferable that the temperature be in the range from the boiling point of the organic solvent of the polycarbonate to the boiling point of the poor solvent for the polycarbonate and the boiling point of water.

The organic solvent is substantially distilled off by supplying the polycarbonate solution to the suspension mixture of the water, the poor solvent and the polycarbonate powder maintained in the above temperature range while stirring, while supplying the polycarbonate solution. Granules can be directly obtained without undergoing a rice cake state and without being crushed by stirring. Therefore, it is not necessary to use a special stirring device, a stirring blade, a kneader, a pulverizer, and the like, and usually, the dispersion state of the polycarbonate powder in the suspension mixture is maintained, and the evaporation of the organic solvent is constantly performed by evaporation. With sufficient stirring (for example, about 100 to 300 rpm), it is possible to easily and quantitatively produce polycarbonate granules having uniform properties. Granules of the polycarbonate produced by the method of the present invention, even after the organic solvent is distilled off, may be filtered as it is, or the granules of the polycarbonate produced by the present invention, after the organic solvent is distilled off, Since the properties do not change due to stirring or heating, if the boiling point of the poor solvent is low, after evaporating the organic solvent, the heating temperature is further raised to the boiling point of the poor solvent to evaporate the poor solvent. And then filtered. The filtered granules are dried and manufactured by a usual method such as drying under reduced pressure and fluidized drying.

A method for producing granules of a polycarbonate composition containing a stabilizer from a polycarbonate solution in the presence of the stabilizer is also within the scope of the present invention. It is known that polycarbonate causes considerable deterioration in hue and molecular weight due to heat history during pelletization and molding, and therefore, when pelletizing, stabilizers such as phosphorus-based processing stabilizers and antioxidants are used. It is known to add. The granules of polycarbonate obtained by the production method of the present invention can be directly molded without passing through a pelletizing step. That is, this means that the number of times of receiving the heat history is small because there is no need to repeat the procedure of once forming a polycarbonate obtained from a polycarbonate solution into a pellet and then molding as in the prior art, and the color tone does not decrease without causing a decrease in molecular weight. It shows that good polycarbonate moldings can be provided. Since the method for producing the polycarbonate granules according to the present invention is performed at a relatively low temperature, the polycarbonate granules produced according to the present invention are not deteriorated by heat at all, but the obtained polycarbonate granules are directly When forming into a molded product such as a film or a sheet, it is preferable to add a stabilizer during the production of the polycarbonate granular material.

The stabilizer may be present in a suspension mixture of water, a poor solvent for polycarbonate and polycarbonate powder, or may be present in a polycarbonate solution. In addition, the same or different stabilizers may be present in the suspension mixture and the polycarbonate solution, respectively.During the production process of the polycarbonate granules, apart from the supply of the polycarbonate solution, a liquid, a solid, a solution or The stabilizer may be supplied in a suspended state. Further, according to the present invention, a polycarbonate granule is produced, and after filtration, a polycarbonate granule containing a part of an organic solvent or a poor solvent and a stabilizer are mixed, and a stabilizer is added to the surface of the polycarbonate granule. A method of drying in a state where it is present may be used. For example, by using a polycarbonate solution prepared by adding a polycarbonate stabilizer to a polycarbonate solution obtained by interfacial polymerization to produce granules of a polycarbonate composition,
Production of granules of a polycarbonate composition while supplying a polycarbonate solution to a suspension mixture comprising a poor solvent for water, polycarbonate, polycarbonate powder and a stabilizer.

Examples of the stabilizer for polycarbonate include processing stabilizers such as phosphorus-based processing stabilizers, antioxidants, and heat stabilizers, and light stabilizers such as ultraviolet absorbers. Specific examples thereof include tributyl phosphite and tris (2
-Ethylhexyl) phosphite, tridecyl phosphite, tristearyl phosphite, triphenyl phosphite, tricresyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite Decyl-diphenyl phosphite, phenyl-di-2-ethylhexyl phosphite, phenyl-didecyl phosphite, tricyclohexyl phosphite, distearyl-pentaerythrityl-diphosphite, tris (mixed mono-, di-phenyl) phosphite , Dinonylphenyl-bis (nonylphenyl)
Phosphites such as phosphite and octyl- (2,2'-di (4,6-di-t-butylphenyl) methylene phosphite

Triethylphosphine, triisopropylphosphine, tri-n-butylphosphine, tricyclohexylphosphine, allyldiphenylphosphine, triphenylphosphine, diphenylphosphine, tris
(2,4-dimethylphenyl) phosphine, tris (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-2-phosphine,
Organic phosphines such as phenylnaphthylbenzylphosphine, triphenylphosphonite, dinonylphenylphosphonite, diisooctylphenylphosphonite, phenyl (2,4,6-trimethylphenyl) phenylphosphonite, [(3-ethyloxetanyl- 3) -Methyl]-
(2,4,6-trimethylphenyl) phenylphosphonite,
Organic phosphonites such as tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite,

2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2′-methylenebis (6-t-butyl-p-cresol), 4,4′-methylenebis (6-t-butyl-o-cresol), 4,4′-methylenebis (6-t-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-t-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,
benzotriazoles such as α-dimethylbenzyl) phenyl] -2H-benzotriazole and 3 ′, 3′-bis [2- (5′-octyl-2′-hydroxyphenyl) benzotriazolyl] methane. . These polycarbonate stabilizers may be used alone or in combination of two or more. Further, the amount of the stabilizer used for the polycarbonate is preferably the minimum amount showing the stabilizing effect,
Although there is a difference depending on each stabilizer, usually 0.1 ppm ~
It is preferable to use about 5000 ppm.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention.

Example 1 25 g of a polycarbonate powder having a particle size of 0.25 to 1 mm (5 wt% with respect to the polycarbonate in a supplied polycarbonate solution) was dispersed in 2 liters of distilled water and 0.9 liter of acetone at 50 ° C.
Until heated. 2.5 kg of a polycarbonate solution containing 20% by weight of a polycarbonate having an average molecular weight of 25,000 produced from bisphenol A under stirring at about 200 rpm.
Was distilled off while feeding over 40 minutes while maintaining the temperature at 47-50 ° C. The formed polycarbonate granules are separated by filtration.
Dried for hours. The particle size and bulk density of the obtained polycarbonate granules are shown in Table 1 (Table 1). Substantially spherical polycarbonate particles having a uniform particle size were obtained.

Example 2 Instead of using 25 g of the polycarbonate powder in Example 1, 150 g of the polycarbonate powder (30 wt% of the polycarbonate in the supplied polycarbonate solution)
%), Except that the granules were used in the same manner as in Example 1. Table 1 shows the particle size and bulk density of the obtained polycarbonate granules. Substantially spherical polycarbonate particles having a uniform particle size were obtained.

Example 3 Polycarbonate granules were produced in the same manner as in Example 1 except that methyl ethyl ketone was used instead of acetone. Table 1 shows the particle size and bulk density of the obtained polycarbonate granules.
Substantially spherical polycarbonate particles having a uniform particle size were obtained.

Example 4 Polycarbonate granules were produced in the same manner as in Example 1, except that ethyl acetate was used instead of acetone. Table 1 shows the particle size and bulk density of the obtained polycarbonate granules. Substantially spherical polycarbonate particles having a uniform particle size were obtained.

Comparative Example 1 For comparison, a poor solvent was added to a polycarbonate solution to produce a polycarbonate. That is, a particle size of 0.25 is added to 2 liters of distilled water.
Polycarbonate solution prepared by dispersing 25 g of a polycarbonate powder of about 1 mm and heating to 50 ° C., and adding 0.9 l of acetone to 2.5 kg of a dichloromethane solution containing 20% by weight of a polycarbonate having an average molecular weight of 25,000 produced from bisphenol A in this suspension. While maintaining the temperature at 47-50 ° C.
The dichloromethane was evaporated off while feeding over minutes.
The obtained polycarbonate was a mixture of a lump and a fine powder, and had a poor uniform particle size. In addition, lump is diameter
Some were about 30 mm, which was extremely inappropriate for use in pelletizing or molding.

Comparative Example 2 Polycarbonate granules were produced without adding polycarbonate powder. That is, acetone 0.9 in 2 liters of distilled water.
The mixture was heated to 50 ° C., and dichloromethane was evaporated by distillation while supplying 2.5 kg of a dichloromethane solution containing 20% by weight of a polycarbonate having an average molecular weight of 25,000 produced from bisphenol A to this mixed solution over 40 minutes. The obtained polycarbonate had a poor uniformity in particle size containing a large amount of fine powder, and was poor in handleability causing scattering of the fine powder.

Comparative Example 3 According to the method of US Pat. No. 4,668,768, instead of supplying a polycarbonate solution, a mixture of a polycarbonate solution, water and a poor solvent is heated to evaporate and remove an organic solvent. Was used to produce polycarbonate granules. That is, an average molecular weight of 25 produced from bisphenol A
2 L of distilled water and 0.9 L of acetone were added to 2.5 kg of a dichloromethane solution containing 20% by weight of 000 polycarbonate and heated to 50 ° C., and dichloromethane was distilled off from the mixture. During the distillation of dichloromethane, the polycarbonate gelled, and during the pulverization of the gel, a large amount of the solvent in the gel was suddenly distilled out, which was dangerous in operation. Also, the obtained polycarbonate contains a large amount of fine powder,
The particle size was poor.

Comparative Example 4 Instead of using 25 g of the polycarbonate powder in Example 1, 1.5 g of the polycarbonate powder (0.3 wt% based on the polycarbonate in the supplied polycarbonate solution)
A polycarbonate granular material was produced in the same manner as in Example 1 except for using. The obtained polycarbonate contained a lump and a fine powder, and was not used for molding.

Comparative Example 5 Polycarbonate granules were produced in the same manner as in Example 1 except that 4 L of acetone was used instead of 0.9 L of acetone. The obtained polycarbonate had an extremely low bulk density.

Comparative Example 6 For comparison, granules of polycarbonate were produced without adding a poor solvent. That is, 25 g of polycarbonate powder having a particle size of 0.25 to 1 mm is dispersed in 2 l of distilled water and heated to 50 ° C.
Average molecular weight produced from bisphenol A in this suspension
Dichloromethane was distilled off while supplying 2.5 kg of a dichloromethane solution containing 25000 polycarbonates at 20% by weight over a period of 40 minutes while maintaining the temperature at 47 to 50 ° C. The obtained polycarbonate does not contain fine powder, but has a particle size
Most are about 10 mm, and the particle size is not uniform,
The shape of the granular material was also various. These were unsuitable for pelletizing or forming.

Example 5 In Example 1, dinonylphenyl- was used as a stabilizer.
Granules of the polycarbonate composition were produced in the same manner as in Example 1, except that 150 ppm of bis (nonylphenyl) phosphite was added to the polycarbonate solution in advance. Table 1 shows the particle size and bulk density of the granular material of the obtained polycarbonate composition. Substantially spherical granules of the polycarbonate composition having a uniform particle size were obtained.

Example 6 In Example 1, dinonylphenyl- was used as a stabilizer.
Granules of the polycarbonate composition were produced in the same manner as in Example 1, except that 150 ppm of bis (nonylphenyl) phosphite was previously added to a suspension mixture of water, acetone and polycarbonate powder. Table 1 shows the particle size and bulk density of the granular material of the obtained polycarbonate composition. Substantially spherical granules of the polycarbonate composition having a uniform particle size were obtained.

[0042]

[Table 1]

Use Example 1 The polycarbonate granules obtained in Example 1 were dried and tested at 280 ° C. with a thickness of 2 mm and 80 × 40 mm using an injection molding machine (model PS-20E2ASE manufactured by Nissei Plastics Industries, Ltd.). A piece was molded.
Measure the yellowness (YI value) with a color difference meter (manufactured by Suga Test Instruments, CDE-SCH-3)
(Hereinafter, the same), measured by a transmission measurement method.
The value was 4.3.

Use Example 2 In the same manner as in Use Example 1, except that the granules of the polycarbonate composition obtained in Example 5 were used instead of the granules of the polycarbonate obtained in Example 1, Then, a test piece having a thickness of 2 mm and a size of 80 × 40 mm was formed. When the yellowness (YI value) was measured by a colorimeter (manufactured by Suga Test Instruments) by a transmission measurement method, the YI value was as good as 3.1.

Use Example 3 In the same manner as in Use Example 1, except that the granules of the polycarbonate composition obtained in Example 6 were used instead of using the granules of the polycarbonate obtained in Example 1, Then, a test piece having a thickness of 2 mm and a size of 80 × 40 mm was formed. When the yellowness (YI value) was measured by a colorimeter (manufactured by Suga Test Instruments) by a transmission measurement method, the YI value was as good as 3.1.

Use Example 4 150 ppm of dinonyl-bis (nonylphenyl) phosphite was used as a stabilizer for the polycarbonate obtained in Comparative Example 2.
Was added and mixed, dried, sieved to a particle size of 0.25 to 1 mm, and pelletized with a 20 mmφ extruder (Toyo Seiki twin screw extruder, extrusion temperature 270 ° C.). Next, the pellets were subjected to an injection molding machine (PS20E2ASE manufactured by Nissei Plastics Industries) in the same manner as in Example 7.
Using a mold, a test piece having a thickness of 2 mm and a size of 80 × 40 mm was formed at 280 ° C. Color difference meter (manufactured by Suga Test Machine)
The YI value was 6.9 when measured by a transmission measurement method.

[0047]

Industrial Applicability According to the present invention, polycarbonate having excellent quality in storage, bag collection, transportation, and handling during molding, containing substantially no fine powder, having a high bulk density, and having a large particle size. Can be efficiently produced without using a special device. In addition, the polycarbonate granules obtained by the present invention can be directly molded without processing such as pelletization, and the heat history of the molded product can be reduced, so that a polycarbonate molded product excellent in color tone is provided. Is what you can do. Therefore, the production method of the present invention is extremely useful industrially.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08J 3/14

Claims (13)

(57) [Claims] 1. A volume ratio of water and water to 0.0
A poor solvent for polycarbonate which is 5 to 1.5 times, and polycarbonate in an organic solvent solution of polycarbonate.
To a suspension mixture of polycarbonate powder in an amount in the range of 0.5 to 50% by weight based on the amount of the polycarbonate, while supplying an organic solvent solution of the polycarbonate with stirring. A process for producing polycarbonate granules, which comprises evaporating and removing an organic solvent to form granules. 2. The process for producing polycarbonate particles according to claim 1, wherein the organic solvent of the polycarbonate is distilled off at a temperature not lower than the boiling point of the organic solvent. 3. The polycarbonate according to claim 1, wherein the organic solvent of the polycarbonate is distilled off at a temperature in the range of from the boiling point of the organic solvent to the boiling point of the poor solvent and the boiling point of water. Manufacturing method of granular material. 4. A volume ratio of water and water to 0.0
A poor solvent for polycarbonate which is 5 to 1.5 times, and polycarbonate in an organic solvent solution of polycarbonate.
Relative to the amount of over bets, the suspension mixture consisting of the amount of poly <br/> carbonate powder ranging from 0.5 to 50% by weight, in the presence of a stabilizer, stirring, polycarbonate organic solvent A process for producing granules of a polycarbonate composition comprising a polycarbonate formed by evaporating and evaporating an organic solvent of polycarbonate while supplying a solution to form granules and at least one stabilizer. 5. The process for producing a granular polycarbonate composition according to claim 4 , wherein the organic solvent of the polycarbonate is distilled off at a temperature not lower than the boiling point of the organic solvent. 6. The organic solvent of the polycarbonate, polycarbonate according to claim 4, characterized in that distilled off at a temperature below the boiling point and the boiling point range of water poor solvent for the polycarbonate from the above the boiling point of the organic solvent A method for producing a granular composition. 7. The method for producing granules of a polycarbonate composition according to claim 4, wherein the stabilizer is previously present in the suspension mixture. 8. claims, characterized in that the stabilizing agent should be present in advance in an organic solvent solution of the polycarbonate 4
A method for producing a granular material of the polycarbonate composition as described above. 9. The method according to claim 1, wherein at least one stabilizer is previously present in the suspension mixture, and at least one stabilizer of the same or different kind is previously present in the organic solvent solution of the polycarbonate. A method for producing a granular material of the polycarbonate composition according to claim 4 . 10. The granules of the polycarbonate composition according to claim 4 , wherein the stabilizer is supplied in a liquid, solid, solution or suspension state during the process of forming the granules of the polycarbonate composition. Manufacturing method. 11. An organic solvent for polycarbonate is distilled off at a temperature in the range of from the boiling point of the organic solvent to the boiling point of the poor solvent and the boiling point of water, and the stabilizer is added to the suspension mixture. The method for producing granules of the polycarbonate composition according to claim 4 , wherein the granules are present in advance. 12. The polycarbonate organic solvent is distilled off at a temperature in the range of from the boiling point of the organic solvent to the boiling point of the poor solvent and to the boiling point of water. 5. The method for producing a granular material of a polycarbonate composition according to claim 4 , wherein the granular material is previously present. 13. An organic solvent for polycarbonate is distilled off at a temperature in the range of from the boiling point of the organic solvent to the boiling point of the poor solvent and the boiling point of water, and at least one stabilizer is suspended and mixed. 5. The method for producing a granular polycarbonate composition according to claim 4, wherein the stabilizer is previously present in the liquid, and at least one stabilizer of the same or different kind is previously present in the solution of the polycarbonate in an organic solvent.