JPH0342288B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing branched polycarbonates. More specifically, a polyvalent phenol of trivalent or higher valence and a monovalent phenol are added to a low molecular weight linear polycarbonate synthesized from divalent phenol and phosgene to cause a reaction, and then divalent phenol is added to initiate a polymerization reaction. The present invention relates to a method for producing a branched aromatic polycarbonate, characterized in that the branched aromatic polycarbonate is completed.

Many of the polycarbonate resins widely used as engineering plastics are
This linear polymer is produced by reacting a phenol with phosgene, but this linear polymer exhibits Newtonian flow behavior under melt processing conditions, and when blow molding or extrusion is performed, it exhibits Newtonian flow behavior due to its own weight. It tends to sag, making it difficult to make large products. For this reason, such molding applications require branched polycarbonates that exhibit non-Newtonian fluidity under melt processing conditions and are less likely to sag during melting.

This non-Newtonian fluidity is expressed by the following formula: Q=K・P ^N (where Q is the flow rate of the molten resin (cc/sec),
K is a constant, P is pressure (Kg/cm ² ), and N is a structural viscosity index. ) can be evaluated using the value of the structural viscosity index N obtained from When N is 1, it indicates Newtonian flow, and 1
The larger the value, the greater the non-Newtonian fluidity.

As a result of investigating the relationship between the above-mentioned structural viscosity index N and sag during blow molding and extrusion molding, the inventor found that N
It has become clear that branched polycarbonate resins with N of 1.4 to 3.5 are less likely to sag during any molding process and can be easily molded into large molded products, compared to highly linear polycarbonate with N of 1.2 to 1.3. Ta.

Therefore, the object of the present invention is to provide a material with a structural viscosity index N of 1.4 to 1.4, which exhibits excellent moldability in blow molding, extrusion molding, etc.
An object of the present invention is to provide a method for producing a 3.5 branched polycarbonate resin.

Conventionally, various methods for producing branched polycarbonates using polyhydric phenols with a valence of 3 or more as a branching agent have been known. There is a problem in that it is not easy to obtain a branched polycarbonate with a high N content in a high yield because the reactivity of phenol is lower than that of dihydric phenol. For example, British Patent No. 923,863 discloses a method in which a polyhydroxy compound obtained from the reaction of phenol and formaldehyde is added during the reaction of dihydric phenol and carbonyl halide. However, in this method, solvent insoluble matter may be generated, or even if not, a thermosetting product may be formed, making it difficult to stably produce branched polycarbonate.

As an improved method, for example, Japanese Patent Publication No. 44-17149 discloses a method in which a polyfunctional compound such as trivalent phenol is added to divalent phenol before phosgene is blown in, and polymerization is carried out by controlling the phosgene blowing rate and reaction temperature. has been disclosed, but this method requires complicated condition settings, making it difficult to implement industrially, and is aimed at solution polymerization. On the other hand, a method using interfacial polymerization is described in Japanese Patent Publication No. 47-23918 and Japanese Patent Publication No. 49-16277, in which divalent phenol and phosgene etc. are combined in the simultaneous presence of trivalent or higher polyvalent phenol and monovalent phenol. Method for reacting carbonic acid derivatives; Special Publication 1973
Publication No. 28193 discloses a method in which a low molecular weight polycarbonate is produced by phosgenation in the simultaneous presence of a divalent phenol and a monovalent phenol, and then a catalyst and a polyvalent phenol of trivalent or higher valence are added.
In these methods, it is not possible to obtain a polycarbonate with a high N content as the object of the present invention, especially when a polyhydric phenol having a valence of 3 or more, which has a lower reactivity than a bisphenol, is used.

In addition, in the polymer solution (organic phase) after this reaction, small droplets of an aqueous solution containing the alkali, divalent phenol, etc. used in the reaction, and the by-products of the reaction, such as salt and soda carbonate, are formed. Since it is stably dispersed, it is necessary to remove and purify it by washing with water, etc., but it has the disadvantage of poor purification performance. Furthermore, in the last mentioned method, the branching agent is limited to polyhydric phenols having a valence of 4 or more.

As a result of intensive research aimed at overcoming the deficiencies of the conventional methods as described above and achieving the object of the present invention, the present inventor first synthesized a low molecular weight linear polycarbonate having reactive groups at both ends. By adding and reacting trivalent or higher polyhydric phenol and monovalent phenol, and then adding and reacting divalent phenol to increase the molecular weight, high yields can be obtained without fear of solvent insolubilization. It was discovered that a branched polycarbonate having an N value can be stably obtained, and the present invention was achieved.

That is, in the present invention, a polyvalent phenol of trivalent or higher valence and a monovalent phenol are first added to a low molecular weight linear polycarbonate obtained by reacting an alkaline aqueous solution of a divalent phenol with phosgene in the presence of an organic solvent. reaction, and then adding divalent phenol to react.The amount of trivalent or higher polyvalent phenol is 0.1 to 2.0 mol% based on the total amount of divalent phenol, and the coexisting divalent phenol is trivalent or higher. 0 per hydroxyl group of polyhydric phenol
3 mol and the volume ratio of the organic phase and the aqueous phase constituting the reaction mixture is 1:0.1 to 1:1.3.

According to the production method of the present invention, it was particularly difficult to react with conventional methods. Even if trivalent or higher polyhydric phenol having at least one benzene ring having two or more hydroxyl groups in its molecular structure is used as a branching agent, a high yield can be achieved and there is no risk of solvent insolubilization.
Branched polycarbonates with high N content can be produced. In addition, since the organic solvent solution of the produced branched polycarbonate can be easily purified by washing with water, there is an advantage of excellent productivity. Furthermore, the branched polycarbonate obtained by the production method of the present invention exhibits high non-Newtonian fluidity and does not easily sag during melt processing, so it is suitable for use in blow molding and extrusion molding, and has the advantage of being able to be processed into large molded products. has.

This feature of the production method of the present invention is that the addition reaction of trivalent or higher polyhydric phenol to a low molecular weight linear polycarbonate having reactive groups at both ends and the polycondensation reaction to increase the molecular weight are carried out separately. Only then can you obtain it. Since the details of the reaction are not clear, the details of the reason for the appearance of these features are not clear, but it can be inferred as follows. In other words, since the addition reaction of trivalent or higher polyhydric phenols to low molecular weight linear polycarbonate is carried out under specific conditions, the reaction rate of trivalent or higher polyvalent phenols increases, and the reaction rate of trivalent or higher polyvalent phenols is increased. It is assumed that branched polycarbonate with a high N content can be obtained without the risk of solvent insolubilization because it is branched due to reaction, but it becomes difficult to form a network. Also,
By subsequently adding divalent phenol to complete the reaction, unreacted chloroformate is eliminated, and unreacted divalent phenol and polyvalent phenols of trivalent or higher valence are also extremely reduced, so branched polycarbonate It is considered that water washing purification of the solution is superior.

As the divalent phenol used in the present invention,
Bisphenols are preferred, especially 2,2-bis(4'-hydroxyphenyl)propane [hereinafter referred to as
Bisphenol A] is preferred. Further, part or all of bisphenol A may be replaced with other divalent phenol. 2 other than bisphenol A
Examples of valent phenols include hydroquinone,
4,4'-dihydroxydiphenyl, bis(4-hydroxyphenyl)alkane, bis(4-hydroxyphenyl)cycloalkane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, Bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ether, 2,2'-bis(3',5'-dimethyl-4'-hydroxyphenyl) enyl) propane and 2,2
Mention may be made of halogenated bisphenols such as -bis(3',5'-dibromo-4'-hydroxyphenyl)propane.

These divalent phenols are used after being dissolved and dispersed in an alkaline aqueous solution. In this case, as the alkali, an alkali metal hydroxide such as caustic soda or caustic potash is preferably used, and the alkali concentration is preferably 3 to 13% by weight. The molar ratio of divalent phenol and alkali to be dissolved and dispersed is 1:1.8 to 1:
3.3 is preferable, more preferably 1:2.2 to 1:3.1
It is.

The organic solvent used in the present invention is substantially insoluble in water and inert to the reaction,
Moreover, it is an organic compound that dissolves polycarbonate produced by the reaction. Specific examples include chlorinated aliphatic hydrocarbons such as methylene chloride, tetrachloroethane, 1,2-dichloroethylene, chloroform, carbon tetrachloride, trichloroethane, dichloroethane; chlorobenzene, dichlorobenzene,
Examples include chlorinated aromatic hydrocarbons such as chlorotoluene; acetophenone, cyclohexanone, anisole, etc. These can be used alone or as a mixture. Among these, methylene chloride is most preferred.

In the present invention, first, an alkaline aqueous solution of divalent phenol and phosgene are reacted in the presence of an organic solvent to produce a low molecular weight linear polycarbonate. At this time, the molar ratio of divalent phenol and phosgene is 1:1.1 to 1:1.5, and the reaction is carried out by blowing phosgene into the above-mentioned alkaline aqueous solution in which divalent phenol is dissolved at a temperature below 25°C in the presence of an organic solvent. It is preferable to do this by folding. The linear polycarbonate obtained by this reaction is preferably
It has a relative viscosity of 1.015 to 1.200 (measured using methylene chloride solvent at a polymer concentration of 0.7 g/100 ml).

The relative viscosity of low molecular weight linear polycarbonate is
If it is less than 1.015, it will be difficult to obtain a branched polycarbonate with a high structural viscosity index, while if it exceeds 1.200, it will tend to gel in the subsequent polycondensation reaction, which is not preferred.

The low molecular weight linear polycarbonate thus obtained is then reacted with polyhydric phenol, but this is not reacted with phosgene in the presence of monohydric phenol, as is done in the previously known method, as described above. Since it is produced by reacting only divalent phenol with phosgene, it is possible to leave reactive groups at both ends, which is advantageous.

In the present invention, a polyhydric phenol having a valence of 3 or more and a monohydric phenol are then added to the reaction mixture containing the above-mentioned low molecular weight linear polycarbonate as it is or to the residual liquid after removing a part of the aqueous phase. Alternatively, it is dissolved in the aqueous alkali solution or organic solvent and added to react.

Examples of trivalent or higher polyhydric phenols used in the present invention include phloroglucin, phloroglucide, 4,6-dimethyl-2,4,6-tri(4'-
hydroxyphenyl)-heptene-2,4,6-
Dimethyl-2,4,6-tri(4'-hydroxyphenyl)-heptane, 1,3,5-tri-(4'-hydroxyphenyl)-benzene, 1,1,1-tri-(4' -hydroxyphenyl)-ethane, 2,2
-bis-[4,4-bis(4'-hydroxyphenyl)cyclohexyl]-propane, 2,6-bis-(2'-hydroxy-5'-methyl-benzyl)-4
-Methyl-phenol,2,6-bis-(2'-hydroxy-5'-isopropyl-benzyl)-4-
Isopropylphenol, bis-[2-hydroxy-3-(2'-hydroxy-5'-methylbenzyl)
-5-Methyl-phenyl]methane, tetra-(4
-Hydroxyphenyl)methane, tri-(4-hydroxyphenyl)phenylmethane, trisphenol, bis(2,4-dihydroxyphenyl)
Examples include ketone, 1,4-bis-(4′,4″-dihydroxytriphenyl-methyl)-benzene, etc., but these may have a halogen substituent.These may also be used in combination. No problem.

Examples of the monovalent phenol used in the present invention include phenol and alkylphenols having a _C1 to _C4 alkyl substituent, particularly p-cresol and pt-butylphenol. These may be substituted with halogen.

The amount of these phenols used is the total amount of dihydric phenols used to produce the branched polycarbonate, i.e. the sum of the amount used to produce the low molecular weight linear polycarbonate and the final amount used. It is determined based on. As described in Examples 3 and 4, when the unreacted divalent phenol dissolved in the aqueous phase extracted from the reaction mixture immediately after producing the low molecular weight polycarbonate is used as the divalent phenol used last. In this case, the total amount of dihydric phenol corresponds to the amount used in the production of low molecular weight polycarbonate. Thus, the amount of polyhydric phenol having a valence of 3 or more is 0.1 to 2.0 mol%, preferably 0.3 to 1.5 mol%, based on the total amount of dihydric phenol. The amount of monovalent phenol used is determined depending on the average molecular weight of the target branched polycarbonate, but is usually 0.5
~10 mol%, more preferably 2-6 mol%. If the amount of trivalent or higher polyhydric phenol used is less than 0.1 mol %, the branching reaction will not proceed sufficiently, and the desired branched polycarbonate with a high structural viscosity index N cannot be obtained. Furthermore, if the amount of polyvalent phenol of trivalent or higher valence exceeds 2.0 mol %, there is a risk that it will gel and become insolubilized in the solvent. Here, when reacting polyhydric phenols with a valence of 3 or more, 2
The smaller the amount of valent phenol, the better. If divalent phenol coexists in an amount exceeding 3 moles per hydroxyl group of trivalent or higher polyvalent phenol, the trivalent or higher polyvalent phenol will be difficult to react with low molecular weight polycarbonate. Therefore, it is difficult to obtain the target branched polycarbonate having a high structural viscosity index N.

At this stage, the volume ratio of the organic solvent phase to the aqueous phase in the reaction mixture is suitably in the range of 1:0.1 to 1.3, preferably in the range of 1:0.1 to 1.2. The reason for this is not clear, but when this volume ratio is less than 0.1, gelation often occurs, and when it exceeds 1.3, it becomes difficult for polyhydric phenols of trivalent or higher valence to react, and in either case, the desired branched polycarbonate with high N content difficult to produce stably.

Next, a catalyst is added to the reaction mixture and the reaction is carried out for 5 to 20 minutes. The catalyst used here is
grade amine or quaternary ammonium salt,
Specific examples include triethylamine, trimethyldodecylbenzylammonium chloride, dimethylbenzylphenylammonium chloride, and trimethyldodecylbenzylammonium hydroxide. The amount added is preferably 0.01 to 1 mol%, more preferably 0.05 to 0.5 mol%, based on the total amount of the dihydric phenol.

Finally, divalent phenol dissolved in an alkaline aqueous solution is added to the reaction mixture, and stirring is continued to complete the polymerization. As described in Examples 3 and 4, the alkaline aqueous solution of divalent phenol used here may be part of the aqueous phase immediately after producing the low molecular weight linear polycarbonate. Further, the concentration of alkali in the alkaline aqueous solution used here is preferably 3 to 13% by weight, and the amount of divalent phenol used is more preferably 1 to 20 mol%, based on the total amount of the divalent phenol. is 6-18
It is mole%.

Since the aqueous phase of the reaction mixture after the completion of the reaction contains a large amount of by-products such as alkali metal hydroxides, carbonates, and chlorides, it is preferable to completely remove these by-products. For this purpose, the reaction mixture can be used as is or diluted with an organic solvent, made acidic by adding an acid such as hydrochloric acid, and then filtered through a hydrophilic material as necessary to separate the aqueous and organic phases. Further, it is preferable that the organic phase is thoroughly washed and purified with water until no inorganic ions are detected. A solid branched polycarbonate can be obtained by removing the organic solvent from the water-washed and purified organic phase.

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.
In addition, the characteristics in the examples were measured by the following method.

[Measurement of structural viscosity index N]

The pre-dried polycarbonate was extruded using an extruder (manufactured by General Electric Co., Model No.
9T51Y106) at 300℃ and pelletized. After drying, the pellets were placed in a cylinder of a Koka type flow tester (manufactured by Shimadzu Corporation) and
Applied pressure P (20~300Kg/
cm ² , 5 points) and the flow rate Q (cc/
sec) was measured, and N was determined from the slope of the regression line obtained by plotting each value on a log-log graph. The larger the structural viscosity index N, the greater the non-Newtonian fluidity, which indicates that it is suitable for blow molding and extrusion molding.

[Measurement of relative viscosity]

0.700 g of the dried sample was dissolved in 100 ml of methylene chloride and measured at 20°C using an Ostwald viscometer.

[Quantification of unreacted bisphenol A]

Separate 1 ml of the aqueous phase from the reaction mixture, dilute it 200 to 1000 times with a dilute aqueous alkali solution, and measure the absorbance A at 294 nm using a spectrophotometer (manufactured by Hitachi, Ltd.; Model 200-10). The amount of bisphenol A was determined from formula (1).

Bisphenol A (g/) = 0.0455A ... (1) [Quantification of unreacted phloroglucin] Separate 1 ml of the aqueous phase from the reaction mixture, dilute it 200 times with a dilute aqueous alkaline solution, and then add it to a spectrophotometer (as above). The absorbance A at 348 nm was measured using the same method, and the following formula was used:
The amount of phloroglucin was determined from (2).

Phloroglucin (g/) = 0.0191A ... (2) [Quantification of unreacted phloroglucide] Separate 1 ml of the aqueous phase from the reaction mixture, dilute it 200 times with a dilute aqueous alkaline solution, and then analyze it with a spectrophotometer (same as above). Measure absorbance A at 357nm using
The amount of phloroglucide was determined from (3).

Phloroglucide (g/) = 0.0303A +0.000015 ...(3) [Quantification of unreacted bis-(2,4-dihydroxyphenyl)ketone] Separate 1 ml of the aqueous phase from the reaction mixture and dilute it with a dilute aqueous alkali solution. After diluting 200 times, use a spectrophotometer (above)
The absorbance A at 323 nm was measured using the following formula (4), and the amount of bis-(2,4-dihydroxyphenyl)ketone was determined from the following formula (4).

Bis-(2,4-dihydroxyphenyl)ketone (g/) = 0.0148A + 0.00007 ...(4) [Evaluation of purification] Add methylene chloride to the reaction mixture to bring the concentration of polycarbonate to 7% by weight. After dilution, the mixture was separated into an organic phase and an aqueous phase. This organic phase 1.5
After adding 0.5 liters of 0.01N hydrochloric acid to the mixture and mixing thoroughly, the mixture was allowed to stand still for separation. Next, I washed it with water. That is, after adding 1.5% pure water to the above organic phase and mixing thoroughly, paper (manufactured by Toyo Paper Co., Ltd., Qualitative Paper No.
2) and allowed to stand for separation. Furthermore, washing was repeated in the same manner until chlorine ions in the washing wastewater were no longer detected by silver nitrate. The smaller the number of water washings, the better the purification performance.

Example 1 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
Add 394 ml of a 12.3% NaOH aqueous solution containing 114 g (0.5 mol) of A and 378 ml of methylene chloride, and add about 69.3 g (0.7 mol) of phosgene at 20 to 25°C while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
The amount was 4.15 g (0.0182 mol), and the relative viscosity of the oligomer produced was 1.095.

Add 3.15 g (0.021 mol) of pt-butylphenol and phloroglucin to this oligomer reaction mixture.
6 ml of a 10% NaOH aqueous solution in which 0.63 g (0.005 mol) was dissolved was added and stirred for 5 minutes, then 0.23 g (0.0023 mol) of triethylamine was added and stirred for 10 minutes to react with phloroglucin. After that,
4 in which 22.8 g (0.1 mol) of bisphenol A was dissolved
% NaOH aqueous solution was added thereto, and stirring was continued for 40 minutes to complete the polycondensation reaction.

The amount of unreacted chloroglucine after the reaction is 0.03
It was hot at g. When the methylene chloride phase was separated from the reaction mixture and purified by water washing according to the purification evaluation method, four water washings were required. After this purification, the methylene chloride was evaporated to recover the polymer. The relative viscosity of the resulting polymer was 1.444, and its structural viscosity index N was 1.72.

Example 2 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
Add 394 ml of a 12.3% NaOH aqueous solution containing 114 g (0.5 mol) of A and 378 ml of methylene chloride, and add about 69.3 g (0.7 mol) of phosgene at 20 to 25°C while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
The amount was 4.05 g (0.0178 mol), and the relative viscosity of the produced oligomer was 1.098. In this oligomer reaction mixture, 1.97 g (0.021 mol) of phenol and 0.91 g (0.0072 mol) of phloroglucin were dissolved in a 10%
After adding 9 ml of NaOH aqueous solution and stirring for 5 minutes, 0.23 g (0.0023 mol) of triethylamine was added and stirring for 10 minutes to react with phloroglucin. After that, 237 ml of a 4% NaOH aqueous solution in which 22.8 g (0.1 mol) of bisphenol A was dissolved was added.
Stirring was continued for about 40 minutes to complete the polycondensation reaction.

The amount of unreacted phloroglucin after the reaction is 0.02
It was hot at g. When the methylene chloride phase was separated from the reaction mixture and purified by water washing according to the purification evaluation method, four water washings were required. The relative viscosity of the resulting polymer is 1.526, and its structural viscosity index N is 2.04.
It was hot.

Example 3 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
8.6% NaOH aqueous solution containing 114g (0.5mol) of A
Add 603 ml and 378 ml of methylene chloride, and add 56.3 g (0.57 mol) of phosgene to about 40 ml at 20-25℃ while stirring.
It took several minutes to introduce the oligomer, and the oligomer was produced.
12.8g of unreacted bisphenol A in the reaction mixture
(0.0561 mol), and the relative viscosity of the oligomer produced was 1.105.

422 ml of aqueous phase was separated from this oligomer reaction mixture, and the remaining reaction mixture (bisphenol A 3.83
g (0.0168 mol)) contains 3.38 g (0.0225 mol) of pt-butylphenol and 0.76 phloroglucin.
g (0.006 mol) dissolved in 10% NaOH aqueous solution 8
After stirring for 5 minutes, 0.19 g (0.0019 mol) of triethylamine was added and stirring for 10 minutes to react with phloroglucin. Thereafter, 422 ml of the above-separated aqueous phase was added, and stirring was continued for 40 minutes to complete the polycondensation reaction.

The amount of unreacted phloroglucin after the reaction is 0.01
It was hot at g. When the methylene chloride phase was separated from the reaction mixture and purified by water washing according to the purification evaluation method, four water washings were required. The relative viscosity of the resulting polymer is 1.556, and the structural viscosity index N is 2.51.
It was hot.

Example 4 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
8.6% NaOH aqueous solution containing 114g (0.5mol) of A
Add 603 ml and 378 ml of methylene chloride, and add 56.3 g (0.57 mol) of phosgene to about 40 ml at 20-25℃ while stirring.
It took several minutes to introduce the oligomer, and the oligomer was produced.
13.3g of unreacted bisphenol A in the reaction mixture
(0.0583 mol), and the relative viscosity of the oligomer produced was 1.103.

From this oligomer reaction mixture, 422 ml of aqueous phase was separated, and the remaining reaction mixture (bisphenol A 3.98
g (0.0175 mol)) contains 3.38 g (0.0235 mol) of pt-butylphenol and 0.35 phlorogluside.
g (0.0015 mol) dissolved in 10% NaOH aqueous solution 4
After stirring for 5 minutes, 0.15 g (0.0015 mol) of triethylamine was added and stirring for 10 minutes to react with phloroglucide. Thereafter, 422 ml of the above-separated aqueous phase was added, and stirring was continued for 40 minutes to complete the polycondensation reaction.

The amount of unreacted phloroglucide after the reaction is 0.01
It was hot at g. When the methylene chloride phase was separated from the reaction mixture and purified by water washing according to the purification evaluation method, four water washings were required. The relative viscosity of the resulting polymer is 1.388, and the structural viscosity index N is 1.71.
It was hot.

Example 5 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
Add 394 ml of a 12.3% NaOH aqueous solution containing 114 g (0.5 mol) of A and 378 ml of methylene chloride, and add 56.3 g (0.57 mol) of phosgene at 20 to 25°C while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
The amount was 4.27 g (0.0187 mol), and the relative viscosity of the oligomer produced was 1.093.

1.97g of phenol in this oligomer reaction mixture.
(0.021 mol) and 0.89 g (0.0036 mol) of bis-(2,4-dihydroxyphenyl)ketone were dissolved.
After adding 5 ml of 10% NaOH aqueous solution and stirring for 5 minutes, 0.23 g (0.0023 mol) of triethylamine was added and stirring for 10 minutes to react the bis(2,4-dihydroxyphenyl)ketone. After that,
4 in which 22.8 g (0.1 mol) of bisphenol A was dissolved
% NaOH aqueous solution was added, and stirring was continued for about 40 minutes to complete the polycondensation reaction.

After the reaction was completed, 0.03 g of unreacted bis(2,4-dihydroxyphenyl)ketone was found. When the methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the purification evaluation method, the number of washings with water required 4 times. The relative viscosity of the resulting polymer was 1.452, and its structural viscosity index N was 2.10.

Comparative Example 1 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
Add 394 ml of a 12.3% NaOH aqueous solution containing 114 g (0.5 mol) of A and 378 ml of methylene chloride, and add about 69.3 g (0.7 mol) of phosgene at 20 to 25°C while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
The amount was 4.25 g (0.0186 mol), and the relative viscosity of the oligomer produced was 1.093.

Add 4.05 g (0.0178 mol) of pt-butylphenol to this oligomer mixture, stir for 5 minutes, and then add 0.23 g (0.0023 mol) of triethylamine.
was added and stirred for 10 minutes to react. Thereafter, 237 ml of a 4% NaOH aqueous solution in which 22.8 g (0.1 mol) of bisphenol A was dissolved was added, and stirring was continued for 40 minutes to complete the polycondensation reaction.

When the methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the purification evaluation method, the number of washings with water required 4 times. The relative viscosity of the resulting polymer is
1.374, and its structural viscosity index N was 1.27.

Comparative Example 2 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
A114g (0.5mol) and phloroglucin 0.76g
(0.006 mol) dissolved in 8.6% NaOH aqueous solution 611ml
Add 378 ml of methylene chloride in which 3.38 g (0.0225 mol) of pt-butylphenol and 3.38 g (0.0225 mol) of pt-butylphenol were dissolved, and while stirring, 56.3 g (0.57 mol) of phosgene was introduced at 20-25°C over a period of about 40 minutes, followed by 0.19 g of triethylamine. (0.0019 mol) was added, and stirring was continued for 50 minutes to allow reaction.

The amount of unreacted phloroglucin after the reaction is 0.75
There was almost no reaction with phloroglucin. The methylene chloride phase was separated from the reaction mixture and washed with water according to the purification evaluation method.
Washing with water required 5 times. The relative viscosity of the resulting polymer is
1.419, and its structural viscosity index N was 1.30.

Comparative Example 3 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
8.6% NaOH aqueous solution containing 114g (0.5mol) of A
Add 603 ml and 378 ml of methylene chloride, and add about 56.3 g (0.57 mol) of phosgene at 20-25℃ while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
12.5 g (0.0548 mol), and the relative viscosity of the oligomer produced was 1.112.

422 ml of aqueous phase was separated from this oligomer reaction mixture, and the remaining reaction mixture (bisphenol A3.73
(containing 0.016 mol) contains 3.38 g (0.0225 mol) of pt-butylphenol and 1.58 g (0.0225 mol) of phloroglucin.
g (0.0125 mol) dissolved in 10% NaOH aqueous solution 15
After stirring for 5 minutes, 0.19 g (0.0019 mol) of triethylamine was added and stirring for 10 minutes to react with phloroglucin. Thereafter, 422 ml of the above-separated aqueous phase was added and stirred, and a gel-like substance insoluble in methylene chloride was formed during the reaction.

Comparative Example 4 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
8.6% NaOH aqueous solution containing 114g (0.5mol) of A
Add 603 ml and 378 ml of methylene chloride, and add about 56.3 g (0.57 mol) of phosgene at 20-25℃ while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
The amount was 12.6 g (0.0551 mol), and the relative viscosity of the oligomer produced was 1.108.

422 ml of aqueous phase was separated from this oligomer reaction mixture, and the remaining reaction mixture (bisphenol A 3.76
g (0.016 mol)) contains 3.38 g (0.0225 mol) of pt-butylphenol and 0.76 phloroglucin.
g (0.006 mol) dissolved in 10% NaOH aqueous solution 8
ml and 34.8 ml of a 10% NaOH aqueous solution in which 9.94 g (0.0435 mol) of bisphenol A was dissolved and stirred for 5 minutes.
mol) and stirred for 10 minutes. Thereafter, 422 ml of the above-separated aqueous phase was added, and stirring was continued for about 40 minutes to complete the polycondensation reaction.

The amount of unreacted phloroglucin after the reaction is 0.74
It was hot at g. When the methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the purification evaluation method, washing with water required 5 times. The relative viscosity of the resulting polymer is
1.378, and the structural viscosity index N was 1.28.

Comparative Example 5 Bisphenol was added to two three-necked flasks equipped with a phosgene inlet tube, a thermometer, and a stirrer.
Add 394 ml of a 12.3% NaOH aqueous solution containing 114 g (0.5 mol) of A and 378 ml of methylene chloride, and add about 69.3 g (0.7 mol) of phosgene at 20 to 25°C while stirring.
The introduction took 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is
The amount was 4.02 g (0.0176 mol), and the relative viscosity of the produced oligomer was 1.092.

This oligomer mixture contains 3.38 g (0.0225 mol) of pt-butylphenol and 0.91 g of phloroglucin.
9 ml of 10% NaOH aqueous solution containing 0.0072 g (0.0072 l)
After adding 173 ml of 1.8% NaOH aqueous solution and stirring for 5 minutes, 0.23 g (0.0023 mol) of triethylamine was added and stirred for 10 minutes. After that, 13% of bisphenol A 22.8g (0.1mol) was dissolved.
70 ml of NaOH aqueous solution was added and stirring was continued for about 40 minutes to complete the polycondensation reaction.

The amount of unreacted phloroglucin after the reaction is 0.90
It was hot at g. The methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the evaluation method for purification, which required 8 washings with water. The relative viscosity of the resulting polymer was 1.372, and its structural viscosity index N was 1.29.

Claims (1)

[Claims] 1. A low molecular weight linear polycarbonate obtained by reacting an alkaline aqueous solution of a divalent phenol with phosgene in the presence of an organic solvent is first treated with a trivalent or higher polyvalent phenol and a monovalent phenol. The amount of trivalent or higher polyvalent phenol is 0.1 to 2.0 mol% based on the total amount of divalent phenol, and the coexisting divalent phenol is trivalent. The above polyhydric phenol has a volume ratio of 0 to 3 moles per hydroxyl group and a volume ratio of the organic phase and aqueous phase constituting the reaction mixture of 1:
A method for producing branched polycarbonate, characterized in that the ratio is 0.1 to 1:1.3. 2. The branched polycarbonate according to claim 1, wherein the trivalent or higher polyvalent phenol is a trivalent or higher polyvalent phenol having at least one benzene ring having two or more hydroxyl groups in its molecular structure. Production method.