JPH08127667A - Porous polycarbonate resin granule and its production - Google Patents

Abstract

PURPOSE: To industrially obtain porous polycarbonate granules useful as a raw material for optical molding materials such as for optical disks or optical lens, polycarbonate resin solutions for cast film formation, compatibilizing agents to be used in polymer blending, and grafted polycarbonates useful as adhesives or coatings etc. CONSTITUTION: An organic solvent solution of a polycarbonate resin containing a granulating solvent is dripped into hot water under agitation maintained within the temperature range from the boiling point of the solvent to the boiling point plus 20 deg.C to form a gel material, which is kept within the temperature range for 5-120min to vaporize mainly the reaction solvent in the gel material, and the resultant gel material is agitated in hot water at 80-l00 deg.C into a water slurry of polycarbonate resin granules, which are then separated from the slurry, thus obtaining the objective porous polycarbonate resin granules having pores each >=4nm in diameter and >=10m<2> /g in specific surface area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate resin solution for cast film formation, a polycarbonate resin molding material for optics, a porous polycarbonate resin granule useful as a raw material for producing a grafted polycarbonate resin, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a resin solution is cast into a film on the surface of a drum or a belt by a casting method to dry a solvent component with hot air to produce a film, or a roll, a plate, and various other members are immersed in the resin solution. It is well known to coat or line its surface. Generally, polycarbonate resin is shipped in the form of powder or pellet. Therefore, these polycarbonate resin solids are usually dissolved in an organic solvent in advance for use as a resin solution. However, since it takes a considerable amount of time to completely dissolve the polycarbonate resin solid matter, the work efficiency is poor and there is a problem in productivity.

When a polycarbonate is dissolved in a solvent, factors such as a polymer structure, a solubility parameter, a crystallinity of the polymer and a surface area are intricately entangled with each other to determine the solubility. H. Schorn et al. Report that amorphous polycarbonates and crystalline polycarbonates have excellent solubility in solvents. (Pol
ymer Sci., Technology 3, pp.296-302) It is generally known that the polycarbonate subjected to the heat-melting treatment is amorphous (Honma Seiichi, "Polycarbonate Handbook", p.172, 1992). However, pellets obtained by melt-extruding a polycarbonate resin produced by an ordinary solution method have a relatively high solubility but have a small surface area, so that the contact area with a solvent is small and it takes a long time to completely dissolve the pellet. Polycarbonate resin having excellent solubility and solution stability, since it may form an insoluble gel, which becomes a defect especially during cast film formation of an electrophotoreceptor and causes a transfer failure when used in a copying machine. A powder is desired.

Conventionally, various methods have been known as methods for obtaining a polycarbonate resin powder or granules. As a method of removing the solvent from the organic solvent solution of polycarbonate to obtain a polycarbonate granular material, for example, Japanese Patent Publication No.
As described in JP-A-5-9875, a method of forming a gelled product in warm water and then pulverizing is generally used. However, the granules produced by this method do not become porous because they have undergone a crystallization process.

Japanese Patent Publication No. 4-71412, Japanese Patent Laid-Open No. 4-712
In 202427, a solidifying solvent is added to a polycarbonate resin solution, the mixture solution is added to warm water under heating, and wet pulverization is performed to obtain a bead-shaped polycarbonate as an aqueous slurry liquid of polycarbonate solid particles. A method of making a resin is disclosed. Further, JP-A-58-206626 and JP-A-59-1332.
Japanese Patent Publication No. 28 describes that, in order to facilitate the drying, it is preferable that it is appropriately porous. Japanese Patent Laid-Open No. 6-1
In the method described in Japanese Patent No. 00703, several tens to several hundreds of meters
Granules having a large specific surface area of ² / g level cannot be obtained, and the granules stick to each other to form lump foreign matter, which causes equipment trouble.

Further, there is known a polycarbonate obtained by graft-polymerizing a vinyl compound such as styrene on a polycarbonate resin. For example, in Japanese Patent Laid-Open No. 65320/1993, an aqueous suspension of a polycarbonate resin is mixed with a vinyl monomer. And a radical polymerization initiator are added, a vinyl monomer and a radical polymerization initiator are impregnated in a polycarbonate resin, and heating is performed to generate a grafting precursor. In this method, it was necessary to sufficiently permeate the vinyl monomer and the radical polymerization initiator into the polycarbonate resin, which necessitated strong stirring and an increase in temperature.

Japanese Unexamined Patent Publication (Kokai) No. 63-278929 discloses a method for extracting a low molecular weight substance from a solid polycarbonate using a mixed solvent of about 2 to 10 times by volume a non-solvent and methylene chloride. . However, the extraction efficiency of the low molecular weight product was low even when the low molecular weight product was extracted using a polycarbonate resin powder produced by a generally known method.

[0008]

Therefore, the present invention is for producing a polycarbonate resin solution used for coating or lining the surfaces of drums, belts, rolls, plates and other various members by a casting method or a dipping method. In, improving the solubility of the polycarbonate resin in an organic solvent, improving the impregnability of the monomer monomer into the polycarbonate resin when producing a polycarbonate graft copolymer, and further, the polycarbonate resin by the solvent It is an object of the present invention to provide a polycarbonate resin granule capable of improving the extraction efficiency of low molecular weight substances and impurities from the granule and a method for producing the same.

[0009]

As one of the methods for solving the above-mentioned various problems, the particle size of the polycarbonate resin powder is made fine so that the specific surface area per unit weight is increased and the contact with a solvent or a monomer is made. By increasing the area, solubility in solvent, reaction rate with reactive monomer,
A method of improving extraction efficiency with an organic solvent can be considered. However, according to the study by the inventors, a large effect cannot be obtained by the method of improving the specific surface area by reducing the particle size of the granular material. The specific surface area of the granular material having a diameter of about 1 mm obtained by the conventional method is 0.01 to
The powder is about 0.02 m ² / g, but even if the particle size is further reduced to 1/10 (= 0.1 mm), theoretically, the specific surface area is only 10 times, so 0.1 to 0.1. 2m ² /
Only a specific surface area of about g can be obtained. Furthermore, if the particle size is made smaller, the powder becomes too fine, which causes problems in handling such as dust generation and bridges in pipes. Further, when the specific surface area is 1 m ² / g or less, the effect cannot be sufficiently achieved.

Therefore, as a result of multi-faceted studies on polycarbonate resin granules, by making the granules porous having a large number of pores, the contact area with solvent molecules and monomer molecules can be widened and dissolved in a solvent. Properties such as properties are improved, and in the case of pores having a pore diameter of less than 4 nm, it is difficult for the solvent or the monomer to be reacted to enter the pores. It has been found that having certain pores is particularly effective.

The present invention improves the dissolution rate in an organic solvent, improves the impregnation rate of a monomer monomer into a polycarbonate resin, and further extracts a low molecular weight substance or impurities from a polycarbonate resin granule by a solvent. As a means for improving efficiency, the above problem is solved by using a polycarbonate resin granule as a porous granule having a specific specific surface area, and as a production method for obtaining such a porous granule,
The present invention has been completed by earnestly investigating a method for producing a porous granular material by controlling the conditions of the granulation when the granulation is performed by dropping the polycarbonate resin solution into warm water.

That is, according to the present invention, the polycarbonate resin organic solvent containing the granulating solvent is added dropwise to the boiling point of the reaction solvent used or to warm water under stirring maintained at a temperature range higher by 20 ° C. than the boiling point to remove the gel substance. The gelled substance is formed and contacted with the warm water for 5 to 120 minutes to volatilize mainly the reaction solvent present in the gelled substance, and then 80 to 100
Porous polycarbonate characterized in that an organic solvent is volatilized from a slurry solution containing the gelled substance in warm water at 0 ° C to obtain an aqueous slurry liquid of polycarbonate resin particles, and the polycarbonate resin particles are separated from the slurry liquid. A method for producing a resin granular material.

The porous polycarbonate resin granules thus obtained have pores with a pore diameter of 4 nm or more and have a specific surface area of 10 m ² / g or more, excellent solubility in organic solvents, and monomers. The polycarbonate resin granules have an improved impregnation rate of a monomer into the polycarbonate resin and further have an improved extraction efficiency of low molecular weight substances and impurities from the polycarbonate resin granules by a solvent.

The structure of the present invention will be described below. The polycarbonate resin referred to in the present invention is a production method similar to the production method of a conventional polycarbonate resin, that is, an interfacial polymerization method,
It is produced by reacting phosgene with a dihydric phenol-based compound as a main component and a small amount of a molecular weight regulator and optionally a branching agent by a solution method such as a pyridine method or a chloroformate method. The homo- or co-polycarbonate resin used is a resin having a viscosity average molecular weight of 13,000 to 100,000, such as a further branched resin or a resin having a long-chain alkyl group introduced at the terminal.

Further, in these polycarbonate resin production methods, a polycarbonate having a graft-polymerizable active group in a molecule is prepared by using a compound having a carbon-carbon unsaturated bond as an end terminating agent or a comonomer, or another compound capable of graft-polymerization. A resin is produced, and a grafted polycarbonate resin obtained by graft-polymerizing styrene or the like, or a polymer obtained by copolymerizing polystyrene with a phenolic hydroxyl group or a compound capable of being graft-polymerized with another polycarbonate resin is graft-polymerized with the polycarbonate resin. Grafted polycarbonate resin and the like can also be used.

Preferred bisphenol compounds used in the method for producing the polycarbonate resin of the present invention are specifically bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) ether and bis (4-hydroxy). Phenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, 1,1-bis (4-hydroxyphenyl)
Ethane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A; BPA), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane 2 (TBA), 2-bis ( 4-hydroxyphenyl)
Butane, 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z; BPZ), 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4- Hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-
Hydroxy-3-chlorophenyl) propane, 2,2-
Bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, α, ω-bis [3- (O
Examples include -hydroxyphenyl) propyl] polydimethylsiloxane (PDS) and biphenol. You may use these in combination of 2 or more types. Among them, those selected from bisphenol A, bisphenol Z, TBA and PDS are preferable.

Examples of the terminal terminator or molecular weight regulator include compounds having a monovalent phenolic hydroxyl group,
Other than ordinary phenol, P-tert-butylphenol, tribromophenol, etc., long-chain alkylphenol, aliphatic carboxylic acid chloride, aliphatic carboxylic acid, aromatic carboxylic acid, aromatic acid chloride, hydroxybenzoic acid alkyl ester, alkyl ether Examples include phenol. Further, a compound having a reactive double bond may be used as a terminal stopper, and examples thereof include acrylic acid, vinyl acetic acid, 2-pentenoic acid, 3-pentenoic acid, 5
Unsaturated carboxylic acids such as hexenoic acid and 9-undecenoic acid; acid chlorides or chloroformates such as acrylic acid chloride, sorbic acid chloride, allyl alcohol chloroformate, isopropenylphenol chloroformate or hydroxystyrene chloroformate Isopropenylphenol, hydroxystyrene,
Examples thereof include phenols having an unsaturated group such as hydroxyphenylmaleimide, hydroxybenzoic acid allyl ester, and hydroxybenzoic acid methylallyl ester. These compounds may be used in combination with a conventional terminal stopper, and are usually used in the range of 1 to 25 mol%, preferably 1.5 to 10 mol% based on 1 mol of the above dihydric phenol compound. To be done.

As a solvent inert to the reaction, chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, 1,1,1-trichloroethane, carbon tetrachloride; aromatic hydrocarbons such as benzene; An ether compound such as diethyl ether may be mentioned, and two or more kinds of these organic solvents may be mixed and used. If desired, ethers, ketones, esters other than the above,
Solvents having an affinity for water, such as nitriles, may be used, provided that the mixed solvent system is not completely compatible with water.

Further, the branching agent is 0.01 to 3.0 mol%, particularly 0.1 to 3.0% with respect to the above dihydric phenol compound.
It can be used as a branched polycarbonate in the range of 1.0 mol%.

As a branching agent, phloroglucin, 2,
6-Dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3,4,6-dimethyl-2,4,6-
Tri (4-hydroxyphenyl) heptene-2,1,
3,5-tri (2-hydroxyphenyl) benzol,
1,1,1-tri (4-hydroxyphenyl) ethane,
2,6-bis (2-hydroxy-5-methylbenzyl)
-4-Methylphenol, α, α ′, α ″ -tri (4-
Hydroxyphenyl) -1,3,5-triisopropylbenzene and other polyhydroxy compounds, and 3,3-bis (4-hydroxyphenyl) oxindole (= isatin bisphenol), 5-chloroisatin bisphenol, Examples include 5,7-dichloroisatin bisphenol and 5-bromoisatin bisphenol.

Examples of aromatic polycarbonate resins include polycarbonates containing bisphenol A as a main raw material, and polycarbonate copolymers obtained by using bisphenol Z or tetrabromobisphenol A (TBA) in combination therewith. Examples thereof include branched products and modified long-chain alkyls at the ends.

The solvent solution is separated from the polycarbonate resin polymerization solution, the catalyst is removed, neutralized, washed with water, concentrated, and the like, and further subjected to centrifugation or microfiltration to obtain a purified polycarbonate resin solution. The resin concentration of this resin solution is 5 to 27% by weight, but the resin concentration is preferably 6 to 23% by weight in order to obtain granules having a desired specific surface area in the present invention.

In the present invention, as a method of solidifying and recovering a polycarbonate resin from a purified polycarbonate resin solution, a non-solvent or a poor solvent is added to the polycarbonate resin solution as a granulating solvent, and the polycarbonate resin containing the granulating solvent is added. The organic solvent solution of is added dropwise to hot water under stirring which is maintained at a boiling point of the reaction solvent used or 20 ° C. higher than the boiling point to form a gel-like substance, and the gel-like substance is added to the hot water for 5 to 120 minutes. After contacting to volatilize mainly the reaction solvent present in the gel-like substance, the organic solvent is then volatilized from the slurry solution containing the gel-like substance in hot water of high temperature of 80 to 100 ° C. to give a polycarbonate resin granular material. To obtain a water slurry solution. This method of volatilizing an organic solvent from a slurry solution containing a gel-like substance in hot water at high temperature to obtain an aqueous slurry liquid of a polycarbonate resin particle is mainly a gel-like substance obtained by volatilizing a reaction solvent present in the gel-like substance. The temperature of the slurry solution containing the substance is raised to 80 to 100 ° C., or 80 to 1
For example, the organic solvent is volatilized by adding a slurry solution containing a gel-like substance to warm water at 00 ° C.

Although the purified polycarbonate resin solution can be dropped into warm water as it is to obtain a solid substance, in order to improve the porosity of the produced granular material and facilitate the drying, It is preferable to add a non-solvent or a poor solvent in advance as the granulating solvent. Examples of the granulating solvent include n-heptane, n-hexane, cyclohexane, benzene, toluene, xylene, and water, and n-heptane and water are particularly suitable for obtaining a granule having a preferred specific surface area. .

In the method of the present invention, the addition amount of the granulating solvent is generally 100: 15 to 100: 300 (0.15 to 3 times the volume of the resin solution) by volume ratio of the polycarbonate resin solution and the granulating solvent. It is added and mixed so that it is properly selected depending on the difference between the SP value of the polycarbonate resin and the SP value of the granulating solvent, and the concentration of the polycarbonate resin solution.

Among the above examples, for example, when the concentration of the polycarbonate resin solution is 15 to 25% by weight,
In the case of n-heptane having a difference in SP value of about 2.3, the volume ratio of the resin solution and the granulating solvent is 100: 15 to 100: 50 (0.15 to 0.5 times the volume of the resin solution), Cyclohexane with SP value difference of about 1.55 is 100: 3.
0 to 100: 60 (0.3 to 0.6 times the volume of the resin solution), 100: 5 for toluene with a SP value difference of 0.9
It is preferably appropriately selected from the range of 0 to 100: 80 (0.5 to 0.8 times the volume of the resin solution). When water is used as the granulating solvent, the volume ratio of the polycarbonate resin solution to water is 100: 30 to 100: 300.
An organic solvent or the like is added so as to be (0.3 to 3 times the volume of the resin solution), and a mixed solution in a suspended state is prepared by using a stirrer having a high shearing force.

When the polycarbonate resin solution is dropped into warm water of a predetermined temperature stored in the granulation tank, for the purpose of preventing mutual adhesion of particles in the granulation tank and improving dispersibility,
It is preferable to use a method in which a part of the warm water is extracted from the granulation tank at the same time as the dropping and is recycled to the granulation tank. The granulating tank is agitated, and a paddle type, a propeller type, a triangular blade or the like is used as an agitating blade. In order to finely disperse the dropped resin solution in warm water, it is preferable to use a reciprocating reversal stirring method.

In the present invention, when the temperature of the warm water to which the polycarbonate organic solvent solution containing the granulating solvent is dropped is lower than the boiling point, the evaporation rate of the solvent is remarkably reduced.
When the temperature of the hot water is 20 ° C. or more higher than the boiling point of the solvent, the evaporation rate of the solvent is too fast and the state of the produced gel becomes unstable, the particle size becomes remarkably coarse, and bulk foreign matter with a reduced bulk density is produced. Therefore, it is not preferable. The gel-like substance produced by dropping the above polycarbonate resin solution into the boiling point of the reaction solvent or warm water maintained at a temperature range higher than the boiling point by 20 ° C. is a sticky solid substance containing a solvent, and this solid substance is It is a granular material having a specific surface area of about 1 m ² / g.

In the present invention, the gel-like substance is added to warm water.
By contacting for 120 minutes to volatilize mainly the reaction solvent present in the gelled substance, and then volatilize the organic solvent in the gelled substance in hot water at a temperature of 80 to 100 ° C., preferably 100 ° C. It is highly porous. In this case, the amount of the residual solvent in the gel-like substance is 20 to 150% by weight based on the dry polycarbonate solid matter by setting the temperature of the hot water and the contact time when the gel-like substance and the hot water are brought into contact with each other within the above ranges. When the residual solvent amount is in the range of%, it is suitable for the subsequent step, that is, for volatilizing the organic solvent in the gel-like substance in hot water at a temperature of 80 to 100 ° C. to promote the porosity.

In the present invention, after the resin solution has been added dropwise to warm water, the gel-like substance formed may be allowed to stay in the warm water under stirring for a desired time if necessary. This residence time is appropriately adjusted within the above contact time range (for example, 10 to 30 minutes in the case of a batch), whereby the amount of residual solvent in the gel-like substance can be adjusted.

In the present invention, the contact time of the gel-like substance with warm water includes the dropping time of the resin solution into the warm water and the total time for allowing the produced gel-like substance to stay in the warm water under stirring for a desired time. When the contact time of the gel-like substance with warm water is shorter than 5 minutes, the gel-like substance foams and the bulk density is lowered when the temperature of the hot water to be subsequently applied is raised, which is not preferable. Further, when the contact time exceeds 120 minutes, the porosity is not improved in the subsequent step which is subsequently carried out, which is not preferable.

The amount of the residual solvent in the gel-like substance depends on the type of solvent, the time required for dropping the resin solution into the warm water, the temperature of the warm water, and the granulating conditions such as the residence time of the gel-like substance in the warm water. receive. As an example of granulation conditions, when methylene chloride having a boiling point of 40.2 ° C. is used as a solvent, the temperature of warm water is 45 ° C. and the contact time is 3
The boiling point is preferably 0 to 80, and the boiling point is 61.2 ° C.
When chloroform is used as a solvent, it is preferable that the temperature of hot water is 77 ± 2 ° C. and the contact time is 15 to 90 minutes.

The method of volatilizing the organic solvent from the thus obtained gelled substance of the polycarbonate resin in hot water at a temperature of 80 to 100 ° C. is a slurry solution itself containing the gelled substance by jacket heating or blowing of steam. Method of increasing the temperature of 100 ° C. to 100 ° C. or a slurry solution containing a gel-like substance in advance of 80 to 100
For example, a method of directly raising the temperature in warm water kept at ℃ and then raising the temperature is used. In particular, when the solvent is methylene chloride, the slurry solution containing the gelled substance is directly added to warm water of about 80 ° C to raise the temperature rapidly, and then the temperature of the warm water is raised to 100 ° C to promote the porosity. The method is preferably used. By keeping the slurry solution containing a gelled substance in warm water at 100 ° C. for 20 to 150 minutes under stirring, the organic solvent in the gelled substance is volatilized (residual solvent amount is 10% or less) to obtain a water slurry. After that, a granular material is obtained by separating and drying the granular material by a method such as centrifugation or filtration.

[0034]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto as long as the scope of the present invention is not exceeded.

In the present invention, the measurement of the specific surface area, the measurement of the solvent solubility and the measurement of the amount of the low molecular weight substance extracted were carried out as follows. Specific surface area measurement: US POURUS MATERIAL
A mercury porosimetry method was used using a PM porosimeter manufactured by the company. The measurement conditions are sample amount 2g, pressure 55181 (PSI),
The measurement was performed with a minimum pore diameter of 4 nm. Measurement of Solvent Solubility: 8 g of polycarbonate resin powder was added to 100 g of various organic solvents and allowed to stand. When the white powder disappeared and the powder was completely dissolved, it was considered as dissolved. Measurement of low molecular weight extractables: Polycarbonate granules 1
00 g was put into 500 mL of an organic solvent for extraction, and agitator (triangular blade: blade length 80 mm × 3 sheets) manufactured by Shimazaki Seisakusho was used, and stirring was performed for 30 minutes at a stirring speed of 60 reciprocations / minute.
After the completion of stirring, the mixture was filtered with a glass filter, the filtrate was concentrated to dryness with an evaporator, and the weight of the residual low molecular weight solid was measured.

Example 1 3.7 kg of sodium hydroxide was dissolved in 42 liters of water, and bisphenol A (B
PA) 7 kg, and hydrosulfite (HD) 29
g was dissolved. Methylene chloride (MC) 28
While adding 1 liter and stirring, 195 g of p-tert-butylphenol (PTBP) was added, and then phosgene (P
G) 3.6 kg was blown in over 60 minutes. After blowing in phosgene, the reaction solution was emulsified by vigorous stirring, and after emulsification, 8 g of triethylamine (TEA) was added and stirred for about 1 hour to polymerize. The polymer solution was separated into an aqueous phase and an organic phase, the organic phase was neutralized with phosphoric acid, and then washed repeatedly with water until the pH of the washing liquid became neutral to obtain a purified polycarbonate resin solution.

The purified resin solution and n-as a granulating solvent are used.
N-Heptane was added to the resin solution and stirred so that the volume ratio to heptane was 100: 20 to prepare an organic solvent solution of polycarbonate. The polycarbonate organic solvent solution was added dropwise to 80 liters of warm water maintained at 45 ° C. under stirring to form a gel-like substance, and the gel-like substance was contacted with warm water for 60 minutes to obtain a water slurry liquid. The amount of residual solvent in the gel-like substance at this time was 85% with respect to the dried solid substance. 1 water slurry containing gel material
After the temperature was raised to 00 ° C. and the stirring was continued for 60 minutes, a wet slurry of polycarbonate was obtained by filtering the water slurry liquid, and a white powdery polycarbonate dry powder was obtained using a hot air circulation dryer at 140 ° C. for 6 hours. Got The specific surface area of the dry powder was 145 m ² / g, the particle size distribution was 10 mesh on ^2.5 wt%, and the 80 mesh pass was 2 wt%.

Examples 2 to 11 Using various dihydric phenols shown in Table 1, a methylene chloride solution of polycarbonate was produced in the same manner as in Example 1, and various solvents shown in Table 1 were used as the granulating solvent. Addition and mixing in various mixing ratios to obtain a solution of polycarbonate in an organic solvent, changing the temperature of warm water and the contact time between the warm water and the gel-like substance to obtain a gel-like substance, and the amount of residual solvent in the gel-like substance Was measured. Further, the slurry liquid containing the gelled substance was heated to 100 ° C., stirred for 60 minutes and then filtered to obtain a granular material, and the specific surface area, the solvent solubility and the extracted amount of the low molecular weight material were measured in the same manner as in Example 1. . For examples of producing a copolycarbonate using two or more types of dihydric phenols, the dihydric phenols (A) and (B)
And the weight ratio is shown in Tables 1 and 3.

Examples 12 and 13 Experiments were conducted in the same manner as in Examples 1 to 11 except that the granulating solvent was not used. The results are shown in Tables 1 and 3.

Comparative Example 1 A methylene chloride solvent solution of a polycarbonate resin prepared by the method of Example was charged into an external jacket heating type kneader (20 mmφ × 800 mm, biaxial), jacket temperature 80 ° C., rotation speed 60 rpm, and stay. Granulation was carried out for 1 hour to obtain granules, and the specific surface area, solvent solubility, and amount of low-molecular-weight substance extracted were measured.

Comparative Example 2 The methylene chloride solution of the polycarbonate resin prepared by the method of Example 1 was added to the n-heptane solvent with stirring for 10 minutes to precipitate and solidify the polycarbonate granules. The specific surface area of the body, the solvent solubility, and the amount of the low molecular weight substance extracted were measured.

Comparative Example 3 When granulation was performed in the same manner as in Example 1 except that the temperature of hot water under stirring was 70 ° C., the residual solvent amount of the gel-like substance was 14%, and the ratio of the granular materials was The surface area was 1.0 m ² / g, and the specific surface area of the granules, the solvent solubility, and the amount of low molecular weight substances extracted were measured.

Comparative Example 4 In Example 1, the slurry of the gel-like substance was heated to 80 ° C. and stirred for 60 minutes, and the specific surface area of the granules, the solvent solubility, and the amount of the low molecular weight substance extracted were measured. The results of Comparative Examples 1 to 4 are shown in Tables 2 and 3.

Comparative Example 5 In Example 1, the polycarbonate resin organic solvent solution was added dropwise to water at 33 ° C. The granules formed by the dropping were adhered to each other to form a candy-like solid.

Example 14 In the polycarbonate production method described in Example, p-
P-isopropenylphenol was used instead of tert-butylphenol to prepare a methylene chloride solution (21.5 wt / wt%) of a terminal unsaturated polycarbonate resin having a viscosity average molecular weight of 16000. The polycarbonate solution and n-heptane were added and mixed so that the volume ratio was 100: 20, and the mixture was mixed with stirring under 4
It was added dropwise to warm water maintained at 8 ° C. to form a gel-like substance, and the gel-like substance was contacted with warm water for 75 minutes. The residual solvent amount of this gel-like substance was 80% based on the solid matter when dried. Furthermore, the temperature of the slurry liquid is 100 ° C.
The temperature was raised to 60 ° C., the mixture was stirred for 60 minutes, and then filtered and dried to obtain a dry end-unsaturated polycarbonate granular material. The specific surface area of this granular material was 25 m ² / g.

Powder of the terminally unsaturated polycarbonate 50
0 g was put into a stainless steel autoclave having an internal volume of 5 L, and 250 mL of pure water was added. Separately, benzoyl peroxide (10-hour half-life temperature 74
C) 2.5 g, 200 g of styrene monomer and 0.2 g of n-dodecyl mercaptan as a molecular weight modifier were added. The temperature of the autoclave was kept at 60 to 65 ° C., and the mixture was stirred for 2 hours to impregnate the terminal unsaturated polycarbonate resin powder with the radical polymerization initiator, styrene, and n-dodecyl mercaptan. The temperature was further raised to 80 ° C., and stirring was continued for 7 hours. At this point, the decomposition rate of the radical polymerization initiator reached 78%. The conversion of styrene monomer is 6
It was 0%. The polymer powder was separated from the suspension, washed with hot water, and then shaken well. The water content at this time was 8% by weight.

This wet powder was treated with a shaft diameter of 30 mm and L / D =
32 vent type twin-screw extruder, the resin temperature is 280
Extruded as ° C. The obtained pellet was transparent.
The pellets are freeze-milled and n-
The styrene monomer not grafted with heptane was extracted, but substantially no monomer was extracted. Furthermore, when the amount of styrene homopolymer produced was further extracted by extraction with toluene, 0.32 g of polymer was extracted per 100 g of polymer. When analyzed by IR, it was confirmed to be polystyrene.

Comparative Example 6 In the polycarbonate production method described in Example 1,
Using p-isopropenylphenol instead of p-tert-butylphenol, a methylene chloride solution (21.5 wt / wt%) of a terminal unsaturated polycarbonate resin having a viscosity average molecular weight of 16000 was prepared. 5 L of the polycarbonate solution was added to n-heptane 50 at 25 ° C. under stirring.
It was added to L to obtain a precipitate of polycarbonate resin granules, which was filtered and dried to obtain dry terminal unsaturated polycarbonate granules. The specific surface area of this granular material was measured and found to be 0.5 m ² / g.

Powder of the terminally unsaturated polycarbonate 50
0 g was put into a stainless steel autoclave having an internal volume of 5 L, and 250 mL of pure water was added. Separately, benzoyl peroxide (10-hour half-life temperature 74
C) 2.5 g, 200 g of styrene monomer and 0.2 g of n-dodecyl mercaptan as a molecular weight modifier were added. The temperature of the autoclave was maintained at 60 to 65 ° C, and the mixture was stirred for 2 hours to impregnate the terminal unsaturated polycarbonate resin powder with the radical polymerization initiator, styrene, and n-dodecyl mercaptan. The temperature was further raised to 80 ° C., and stirring was continued for 7 hours. At this point, the decomposition rate of the radical polymerization initiator reached 75%. The conversion of styrene monomer is 4
It was 0%. The polymer powder was separated from the suspension, washed with hot water, and then shaken well. The water content at this time was 8% by weight.

This moist powder was treated with a shaft diameter of 30 mm and L / D =
32 vent type twin-screw extruder, the resin temperature is 280
Extruded as ° C. The obtained pellet was transparent.
The pellets are freeze-milled and n-
When styrene monomer not grafted with heptane was extracted, 4.5 g of styrene monomer was extracted per 100 g of the polymer. Further, when the amount of styrene homopolymer produced was examined by further extraction with toluene, 2.8 g of polymer was extracted per 100 g of polymer. When analyzed by IR, it was confirmed to be polystyrene.

[0051]

INDUSTRIAL APPLICABILITY As described above, the porous polycarbonate particles having a high specific surface area produced by the method of the present invention have a high dissolution rate in a solvent and are suitable for a polycarbonate for cast film formation, and the granular particles. Since it is possible to improve the extraction efficiency when extracting impurities and low molecular weight substances remaining in the organic solvent, as an excellent raw material as an optical molding material, and also the contact area with the monomer monomer becomes high, The reaction rate can be improved.
Further, according to the present invention, it is possible to very easily obtain a granular material having a high specific surface area.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

Claims (4)

[Claims] 1. A polycarbonate resin organic solvent containing a granulating solvent is used, the boiling point or the boiling point of the reaction solvent used is 2 or more.
It was added dropwise to warm water under stirring maintained in a high temperature range of 0 ° C,
A gel-like substance is produced, and the gel-like substance is mixed with the warm water for 5 to 12
The reaction solvent mainly present in the gel-like substance is volatilized by contacting for 0 minutes, and then the organic solvent is volatilized from the slurry solution containing the gel-like substance in warm water at 80 to 100 ° C. to evaporate the water of the polycarbonate resin granules. A method for producing porous polycarbonate resin particles, which comprises forming a slurry liquid and separating the polycarbonate resin particles from the slurry liquid. 2. A slurry containing a gel-like substance in hot water of 80 to 100 ° C., after evaporating mainly a reaction solvent present in the gel-like substance and then raising the temperature of the hot water to 80 to 100 ° C. The method according to claim 1, wherein the solution is charged to volatilize the organic solvent to obtain an aqueous slurry liquid of the polycarbonate resin particles. 3. The method according to claim 1, wherein the granulating solvent is at least one selected from n-heptane, n-hexane, cyclohexane, benzene, toluene, xylene, and water. 4. A porous polycarbonate resin granular material, wherein particles having pores having a pore diameter of 4 nm or more have a specific surface area of at least 10 m ² / g.