JPS60163919A - Method for manufacturing branched polycarbonate - Google Patents

Abstract

PURPOSE:To obtain in high yields a branched polycarbonate having no fear of insolubilization in a solvent and improved in hue, by reacting a low-MW linear polycarbonate with a specified polyphenol and a monophenol. CONSTITUTION:A low-MW linear polycarbonate obtained by reacting an aqueous alkaline solutionof a diphenol with phosgene in the presence of an organic solvent is reacted first with a polyphenol having, in its molecular, structure, benzene ring having at least three hydroxyl groups and a monophenol, and then completing the reaction by adding an aqueous alkali solution to the reaction system. The amount of said polyphenol added is 0.05-1.5mol% based on the total weight of the diphenol and the amount of unreacted diphenol present at the paint of the addition of the at least trihydric polyphenol should be 3mol or below per hydroxyl groups of the at leat trihydric polyphenol. Said aqueous alkali solution should be used in an amount of 10-100mol% based on the total weight of the diphenol used and has an alkali concentration of 1-50wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing branched polycarbonate. More specifically, low molecular weight linear polycarbonate 1~ synthesized from dihydric phenol and phosgene has a benzene ring having three or more hydroxyl groups in its molecular structure.
The present invention relates to the production of a branched aromatic polycarbonate, in which a polyhydric phenol and a monohydric phenol having a higher valence are added and reacted, and then an alkaline aqueous solution is added to complete the polymerization reaction.

[Prior art] Most of the polycarbonate resins widely used as engineering plastics are linear polymers produced by reacting dihydric phenol and phosgene. It exhibits Newtonian flow behavior and tends to sag due to its own weight during blow molding and extrusion molding, making it difficult to make large molded products.

Therefore, for such molding applications, under melt processing conditions,
Branched polycarbonates are required because they exhibit non-Newtonian flow and tend to sag during melting.

This non-Newtonian fluidity is expressed as %formula% It can be evaluated by the value of the structural viscosity index N that can be entangled.

When N is 1, it indicates Newtonian flow, and when N is greater than 1, it indicates that non-Newtonian fluidity increases.

The present inventor has developed blow molding with the above-mentioned structural viscosity index N.

As a result of investigating the relationship with sagging during extrusion molding, N was 1.2~
Compared to polycarbonate with strong linearity of 1.3, N is 1
．． It has become clear that polycarbonate resins with 4 to 3.5 branches are less likely to sag during any molding process and can be easily molded into large molded products.

Many methods for producing such branched polycarbonates have been known, including using polyhydric phenols with a valence of 3 or more as a branching agent. Furthermore, there is a problem that it is not easy to obtain a branched polycarbonate with a high N content in a high yield because the reactivity of a polyhydric phenol having a valence of 3 or more is lower than that of a dihydric phenol.

For example, in Japanese Patent Publication No. 44-17149, a polyfunctional compound such as phloroglucin is added to dihydric phenol before phosgene is blown in, and the phosgene is blown quickly.

A method of polymerization by controlling the 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 JP-A-47-23918@, in which a dihydric phenol and a carbonic acid derivative such as phosgene are reacted in the simultaneous presence of a trivalent or higher polyhydric phenol and a monohydric phenol. One method, Japanese Patent Publication No. 53-28193, discloses a method in which phosgene is added in the simultaneous presence of dihydric phenol and monohydric phenol to produce a low molecular weight polycarbonate, and then a catalyst and a polyhydric phenol of tetrahydric or higher hydric phenol are added. However, with 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 such as phloroglucin, which has lower reactivity than bisphenol, is used. Also, the polymer solution after this reaction (
In the organic phase, an aqueous solution containing the alkali, dihydric phenol, etc. used in the reaction, and the by-products of the reaction, such as salt and soda carbonate, is stably dispersed in the form of small water droplets. It is necessary to remove them and purify them, but
It has the disadvantage of poor refining properties.

Furthermore, JP-A-58-185619 discloses a method in which polycarbonate oligomers are reacted with a polyfunctional compound and then dihydric phenol is added to perform polycondensation, but regarding the use of polyhydric phenols such as phloroglucin, , there is no description.

4- [Objective of the Invention] The object of the present invention is to use a polyhydric phenol such as phloroglucin, which is industrially easily available but has poor reactivity, as a branching agent in a high yield and without the risk of solvent insolubilization. , and has a structural viscosity index N of 1.4 to 3.5, which shows good purification by washing the organic solvent solution of the obtained polymer, improved hue, and excellent moldability in blow molding, extrusion molding, etc. An object of the present invention is to provide a method for producing a branched polycarbonate resin.

``Structure of the Invention'' The present invention first involves adding a polyhydric phenol of trihydric or higher hydric phenol and a monohydric phenol to a low molecular weight linear polycarbonate obtained by reacting an alkaline aqueous solution of dihydric phenol with phosgene in the presence of an organic solvent. Add and react, then,
In the method for producing branched polycarbonate in which the reaction is completed by adding an aqueous alkali solution, a polyhydric phenol having a benzene ring having three or more hydroxyl groups in its molecular structure is used as the trivalent or higher polyhydric phenol, The amount is 0.05 to 1.0% based on the total amount of dihydric phenol.
5 mol%, and when the polyhydric phenol with a valence of 3 or more is added, the unreacted dihydric phenol is 3 mol or less per hydroxyl group of the polyhydric phenol with a valence of 3 or more. and the volume ratio of the organic phase to the aqueous phase constituting the reaction mixture is 1:0.1 to 1:1.2, and the aqueous alkaline solution added subsequently is 10% of the total amount of dihydric phenol used. ~100 mol%, and the alkali concentration is 1 to 5
This is a method for producing branched polycarbonate, characterized in that the amount of branched polycarbonate is 0% by weight.

As the dihydric phenol used in the present invention, bisphenols are preferable, and 2,2-bis(4-hydroxyphenyl)propane [hereinafter referred to as bisphenol A] is particularly preferable. Further, part or all of bisphenol A may be replaced with a dihydric phenol. Examples of dihydric phenols other than bisphenol A 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(
Mention may be made of halogenated bisphenols such as 3,5-dimethyl-4-hydroxyphenyl)propane and 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane.

These dihydric 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 dihydric phenol and alkali to be dissolved and dispersed is preferably 1:1.8 to 1:3.3, more preferably 1:2.2 to 1:3.1.

The organic solvent used in the present invention is an organic compound that is substantially insoluble in water and inert to the reaction, and further dissolves the polycarbonate produced by the reaction. Specific examples include chlorinated aliphatic hydrocarbons such as methylene chloride, tetrachloroethane, 1,2-dichloroethylene, chloroform\, carbon tetrachloride, trichloroethane, and dichloroethane; chlorobenzene, dichlorobenzene, and chlorotoluene. chlorinated aromatic hydrocarbons such as 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 dihydric phenol and phosgene are reacted in the presence of an organic solvent to produce a low molecular weight linear polycarbonate. At that time, the molar ratio of dihydric phenol and phosgene is 'l:1,1~1:1
．． 5, and the reaction is preferably carried out by blowing phosgene into the aqueous alkaline solution in which dihydric phenol is dissolved at 25° C. or lower in the presence of an organic solvent.

The linear polycarbonate obtained by this reaction preferably has a relative viscosity of 1,015 to 1.200 (using a salt 8-methylene solvent and a polymer concentration of 0.79/10
ord1. , measured at 20°C). If the relative viscosity of the low-molecular suspended linear polycarbonate is less than 1.015, it is difficult to obtain a branched polycarbonate with a high structural viscosity index, whereas if it exceeds 1.200, it tends to gel easily in the subsequent polycondensation, which is not preferred.

The low-molecular-weight linear polycarbonate thus obtained is then reacted with polyhydric phenol, but this is different from reacting with phosgene in the coexistence of monohydric phenol using the previously known method as described above. Since it is produced by reacting only monohydric phenol with phosgene, it is possible to leave reactive groups at both ends, which is advantageous.

In the present invention, a benzene ring having three or more hydroxyl groups is 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 in its molecular structure. A polyhydric phenol having a valence of 5 or more and a monohydric phenol are added as they are or dissolved in the aqueous alkali solution or organic solvent and reacted.

Examples of the trivalent or higher polyhydric phenol having a benzene ring having a trivalent or higher hydroxyl group in its molecular structure used in the present invention include phloroglucin.

Examples include phlorogluside, 70 propion and derivatives thereof. These may be used in combination.

Furthermore, examples of the monohydric phenol used in the present invention include phenol, alkylphenols having a C+ to C4 alkyl substituent, particularly p-cresol, p-[-
Butylphenol is mentioned. These may be substituted with halogen.

The amount of trivalent or higher polyhydric phenol having a benzene ring having three or more hydroxyl groups in its molecular structure is 0.05 to 1.5 mol%, based on the amount of dihydric phenol used. Preferably it is 0.1 to 1.0 mol%. The amount of monohydric phenol used is determined depending on the average molecular weight of the target branched polycarbonate, but is usually 0.5 to 10 mol%, more preferably 2 to 7 mol%, based on the amount of dihydric phenol used. It is. If the amount of trihydric or higher polyhydric phenol used is less than 0.05 mol %, the branching reaction will not proceed sufficiently, and the desired branched polycarbonate with a high structural adhesion index N cannot be obtained. Furthermore, if the amount of the trivalent or higher polyhydric phenol used exceeds 1.5 mol %, there is a risk that it will gel and become insolubilized in the solvent. Here, when the polyhydric phenol having a valence of 3 or more is reacted, the coexisting unreacted 2
The smaller the amount of the hydric phenol, the less the dihydric phenol is 3 moles or less per hydroxyl group of the trivalent or higher polyhydric phenol; If more than 3 moles per individual coexist, the trihydric or higher polyhydric phenol will be difficult to react with the low molecular weight polycarbonate, and therefore it will be difficult to obtain the desired branched polycarbonate with 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 preferably within the range of 1:0.1 to 1:1.2. The reason is not clear, but this volume ratio is 0
．． If it is less than 1, gelation will often occur, and if it exceeds -1+- or 1 or 2, the trihydric or higher polyhydric phenol will be difficult to react, and in either case, the desired branched polycarbonate with high N content cannot be stably produced. difficult to do.

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 a tertiary amine or a quaternary ammonium salt, and specific examples include triethylamine, trimethyldodecylbenzylammonium chloride, dimethylbenzylphenylammonium chloride, trimethyldodecylbenzylammonium hydroxide, etc. be able to. 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.

5 to 20 minutes after adding the catalyst, an aqueous alkaline solution is added to the reaction mixture and stirring is continued to complete the polymerization. The alkaline aqueous solution used here is 10 to 100 mol%, preferably 50 to 100 mol%, based on the total amount of dihydric phenol used.
It contains 90 mol% of caustic soda, and its alkaline concentration is suitably 1 to 50% by weight, preferably 10 to 50% by weight. The amount of alkali used is 1
If it is less than 0 mol%, it is difficult for the polymerization reaction to proceed. Furthermore, if the alkali concentration is less than 1% by weight, emulsification will be insufficient and polymerization will be difficult to proceed, and an aqueous alkaline solution of 50% by weight or more will be difficult to handle, which is not preferred.

Since the aqueous phase of the reaction mixture after 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 is used as it is or diluted with an organic solvent, made acidic by adding an acid such as hydrochloric acid, and then filtered with a hydrophilic filter medium as necessary to separate it into an aqueous phase and an organic phase.
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.

[Effects of the Invention] According to the production method of the present invention, a trihydric or higher polyhydric alcohol having a penzene ring having three or more hydroxyl groups in its molecular structure, which was difficult to react with in conventional methods, can be used as a branching agent. Even when used as a branched polycarbonate, it can be used in high yield without the risk of solvent insolubilization, has a high N content, and has a good color.
can be manufactured. Moreover, since the produced organic solvent solution of the branched polycarbonate can be washed with water, the purification property is good, so there is an advantage of excellent productivity. Furthermore, since there is almost no unreacted phenol at the end of the reaction, there is an advantage that the reaction yield is high and the load on the waste liquid treatment step is reduced.

Furthermore, the branched polycarbonate prepared by the 1# method of the present invention exhibits high non-Newtonian fluidity and does not easily sag during melt processing, so it can be suitably used for blow molding and extrusion molding, and can be processed into large molded products. It has the advantage of being able to

This feature of the product produced by the production method of the present invention is that the addition reaction of the trihydric or higher polyhydric phenol to the low molecular weight linear polycarbonate having reactive groups at both ends and the polycondensation reaction to increase the molecular weight are separated. First, it can only be obtained by carrying out the polycondensation reaction to increase the molecular weight by adding only an aqueous alkali solution. 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. That is,
Since the addition reaction of the trihydric or higher polyhydric phenol to the low molecular weight linear polycarbonate is carried out under specific conditions, the reaction rate of the trivalent or higher polyhydric phenol increases, and
Because it is reacted at the same time as the phenol, it is branched, but it becomes reticulated and sealed, so there is no risk of solvent insolubilization.
It is presumed that a branched polycarbonate with a high N content can be obtained. Furthermore, by adding an aqueous alkali solution to complete the reaction, the reaction between the unreacted chloroformate end groups and the unreacted OH groups is promoted, and the chloroformate ends disappear and the unreacted 01-1 groups are removed. It is thought that since almost no lυ is eliminated, the branched polycarbonate solution has excellent water-washing purification properties, and the number of unreacted 01-1 groups is also reduced, resulting in a better hue of the obtained polymer.

[Example] 15- 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 put into an extruder (General
Made by Electric ■: Model No. 9T51Y106
) and pelletized at 300°C.

After drying, the pellets were placed in a cylinder of a Koka type flow tester (Shimadzu Corporation ■￥J), and the pressure p (20 to 1 eoig/crl) was applied at a constant temperature of 280 to 300°C.
.

5 points) and the respective molten resin flow rate Q (cffl/sec
), and N was calculated from the slope of the regression line obtained by plotting each value on a log-log graph. Structural viscosity index N
A large value indicates that the material has high non-Newtonian fluidity and is suitable for blow molding and extrusion molding.

[Measurement of relative viscosity] Dried samples o and yoog were mixed with 100ml of methylene chloride!
It was measured at 20°C using an Ostwald viscometer.

[Quantification of unreacted bisphenol A] Separate 1 ml of the aqueous phase from the reaction mixture and dilute it 200 to 1000 times with a dilute alkali 16-aqueous solution at 294 nm using a backward photometer (manufactured by Hitachi, Ltd. 11; Model 200-10).
The absorbance Δ was measured, and the amount of bisphenol A was calculated from the following formula (1).

Bisphenol A (g/day) = 0.0455 A
...(1) [Quantification of unreacted phloroglucin] Separate the aqueous phase 11d from the reaction mixture, dilute it 200 times with a dilute aqueous alkaline solution, and measure the absorbance at 348 nm using a spectrophotometer (same as in "-"). A was measured, and the mother of 70 glucins was calculated from the following formula (2).

70 glucine (g/day) = 0.0191 A...
...(2) [Quantification of unreacted phloroglucide] Separate 1d of the aqueous phase from the reaction mixture, dilute it 200 times with a dilute alkali aqueous solution, and measure the absorbance at 357 nm using a spectrophotometer (same as above). Measure A and use the following formula (3) to calculate 70
I increased the amount of oral glucide.

Phlorogluside (g/cross) = 0.0303 A+ 0.000015...
・(3) [Quantification of unreacted bis(2,4-dihydroxyphenyl)ketone] Separate 1 mQ of the aqueous phase from the reaction mixture, dilute it 200 times with a dilute aqueous alkali solution, and measure it using a spectrophotometer (above). Use 3
The absorbance A at 23 nm was measured, and bis(
The amount of 2,4-dihydroxyphenyl)ketone was measured.

Bis(2,4-dihydroxyphenyl)keyne (σ/
ρ) = 0.0148 A + 0.00007...
・・・・・・・・・(4) [Evaluation of purification property] Add methylene chloride to the reaction mixture and dilute it so that the concentration of polycarbonate is 7% by weight, and then divide the mixture into an organic phase and an aqueous phase by 1 Ilt L. ,Ta. 0.0 to 1.5 bases of this organic phase.
After adding 0.5 liters of 0.1N hydrochloric acid and thoroughly mixing, the mixture was allowed to stand for separation. Next, I washed it with water. That is, 1. After adding pure water of F+JJ and thoroughly mixing, the mixture was filtered through a filter paper (manufactured by Toyo Roshi Co., Ltd., corrected filter paper N0.2) and separated by standing. Furthermore, water washing was repeated in the same manner until chloride ions in the washing wastewater were no longer detected by silver nitrate. The smaller the number of water washings, the better the purification performance.

19- [Evaluation of Hue] The obtained polycarbonate powder was heated to a temperature of 280°C using vented extrusion IM (30sφ) to form 2 to 3 mmφ×
After making it into pellets with a length of 2 to 3 mm, it was made into 5 cm x 7 pieces at 320°C using a daily anchor V-17El'l extrusion molding machine.
It was molded into a sample plate measuring cm x 2 mm. The hue of this sample plate was measured using a digital colorimeter made by Suga Test Instruments ■. Hue is expressed by L (brightness), a (reddish), and b (yellowish), and the larger the b value, the stronger the yellowishness.

Therefore, the smaller the b value, the more preferable it is. To compare hues,
This b value was used.

Example 1 A phosgene blowing pipe, a thermometer and a stirrer were installed 2
In a summer Mitsuro flask, add 114 g of bisphenol A (0,
12.3% Na0)-1 aqueous solution 39
4 me and 378 mQ of methylene chloride were added, and while stirring, 69.37 (0.7 mol) of phosgene was introduced at 20 to 25°C over about 40 minutes to produce oligomers. Unreacted bisphenol Δ in the reaction mixture is 4.1
09 (0,0180 mol), and the relative viscosity of the oligomer produced was 1,098.

To this oligomer reaction mixture, 3.15 g (0,021 mol) of pt-butylphenol and 0.0 g of phloroglucin were added.
38 (J (0,003 mol) dissolved in 10% Na
After adding 5 mQ of OH aqueous solution and stirring for 5 minutes, 0.239 (0,0023 mol) of triethylamine was added and stirring for 10 minutes to react with phloroglucin. An aqueous solution 16d (24.3 g) in which 41.12 g (0.3 mol) of NaOH was dissolved was added and stirring was continued for 40 minutes to complete the reaction.

The amount of unreacted phloroglucin after the completion of the reaction was 0.043. When the methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the purification evaluation method, four washings with water were required. After purification, the methylene chloride was evaporated and the polymer was recovered. The relative viscosity of the resulting polymer was 1,450. The structural viscosity index is 1.75.

The b value was 5.4.

Example 2 2 equipped with phosgene blowing pipe, thermometer and stirrer
12.3% NaO in which 114 g (0.5-El) of bisphenol A-2 was dissolved in a Danmitsuro flask.
Add 394 d of H aqueous solution and 378 ml of methylene chloride, and add 69.3 g of phosgene (0.7
mol) was introduced over a period of about 40 minutes to generate oligomers. Unreacted bisphenol A in the reaction mixture is 4.
02 g (0,0176 mol), and the relative viscosity of the produced oligomer was 1.09.

This oligomer reaction mixture contains phenol 1.979 (
0,021 mol) and phloroglucin 0.51 g (0,
After adding 7 mQ of a 10% NaOH aqueous solution containing 0.004 mol) of triethylamine and stirring for 5 minutes, 0.2 mol of triethylamine was added.
3 g (0,0023 mol) was added and stirred for 10 minutes to react with phloroglucin. After that, 16g (
0.4 mol) of NaOH dissolved in an aqueous solution 45d (
62 g) was added and stirring was continued for 40 minutes to complete the reaction.

The amount of unreacted phloroglucin after the reaction was completed was 0.03 g.
Met. When the methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the purification evaluation method, four washings with water were required. The resulting polymer has a relative viscosity of 1.485, a structural viscosity index of 1.84, and a b value of 5.
It was 8.

Example 3 2 equipped with phosgene blowing pipe, thermometer and stirrer
Bisphenol A114!7 (0
, 5 mol) dissolved in 8.6% NaOH aqueous solution 603
Add the snake and 378d of methylene chloride, stirring for 20 minutes.
56.3 g (0.57 mol) of phosgene at ~25°C
The introduction took 0 minutes to generate oligomers. The amount of unreacted bisphenol A in the reaction mixture was 12.89 (0
,0561 mol), and the relative viscosity of the oligomer produced was 1,104.

422 mQ of aqueous phase was separated from this oligomer reaction mixture, and the remaining reaction mixture (3.83 g of bisphenol A
(0,0168 mol) containing 3.38 g (0,0235 mol) of pt-butylphenol and 0.28 g (0,0012 mol) of phlorogluside dissolved in 10
% Na0l-1 aqueous solution was added, and after stirring for 5 minutes, triethylamine 0.15';l (0,001
5 mol) was added and stirred for 10 minutes to react with phlorogluside. After that, 12 g (0.3 mol) of Na
Add 50me (63g) of an aqueous solution containing OH and mix for 40 minutes.
Stirring was continued for a minute to complete the reaction.

After the reaction is complete, the remaining unreacted phloroglucide is o, oi g.
Met. The methylene chloride phase was separated from the reaction mixture and purified by water washing according to the purification evaluation method.
It took several times. The relative viscosity of the produced polymer is 1.372, its structural viscosity index N is 1.64, and the b value is 5.
It was 3.

Comparative example 1 2 equipped with phosgene blowing pipe, thermometer and stirrer
Bisphenol A114f# (
0.5 mol) and phloroglucin 0.76 g (0.00
8.6% NaOH aqueous solution 6111 containing 6 mol)
ft! 3.38 g (0,
0225 mol) of methylene chloride dissolved in 378 m (1
of phosgene at 20-25°C while stirring.
After introducing 3 g (0.57 mol) over a period of about 40 minutes,
0.19 g (0,0019 mol) of triethylamine was added, and the mixture was stirred for 50 minutes, followed by reaction.

23- The amount of unreacted phloroglucin after the reaction is 0.75 g.
There was almost no reaction with phloroglucin. When the methylene chloride phase was separated from the reaction mixture and washed with water according to the purification evaluation method, the water washing required 5 times.

The relative viscosity of the produced polymer was 1.419, and its structural viscosity index N was 1.30.

Comparative Example 2 2 with a phosgene blowing pipe, thermometer and stirrer installed
In a summer Mitsuro flask, add 114 g of bisphenol A (0,
12.3% NaO 1 aqueous solution 394
Add 378 d of methylene chloride and 20 d of methylene chloride while stirring.
69.5 g (0.7 mol) of phosgene at ~25°C
The introduction took 0 minutes to generate oligomers. Bisphenol A in the reaction mixture was 4.0g (0,0176
mole), and the relative viscosity of the oligomer produced is 1,099
Met.

To this oligomer reaction mixture were added 3.15 g (0,021 mol) of pt-butylphenol and 0.7 g of glucine.
10% NaO in which 38 Ij (0,003 mol) was dissolved
24-]'' aqueous solution 5#112 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, 50 d of an aqueous solution containing ``i, ag (0,045 mol) of Na01'' was dissolved! <52.3 g) was added and stirring was continued for 40 minutes to complete the reaction.

The amount of unreacted phloroglucin after the completion of the reaction was 01OS9. The methylene chloride phase was separated from the reaction mixture and purified by washing with water according to the purification evaluation method, and the washing with water required 8 times. After purification, the in-situ methylene was evaporated to recover the polymer. The relative viscosity of the produced polymer was as low as 1.225, and the molecular weight was not very increased.

Patent applicant Teijin Kasei Co., Ltd. Company procedures
Amendment Written by Dangetsu, 1980 - Mr. Han, Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 16949, No. 16949, 2, Name of the invention, Process for producing branched polycarbonate 3, Person making the amendment Relationship with the case Representative of the patent applicant Person Yoshiki Yamazaki Contact information (506) 4481 5. Subject of amendment (1) In the 15th page, lines 1-2 of the specification, "polyhydric alcohol" should be corrected to "polyhydric phenol."

(2) From the second line from the bottom of page 18 to the seventh line of page 19, delete the text ``[Unreacted gas......(4)]''.

(31, 22nd negative line 7 says r 1.09 J.
Corrected to 1.099 J.

that's all 2-

Claims (1)

[Claims] A low molecular weight linear polycarbonate obtained by reacting an alkaline aqueous solution of dihydric phenol with phosgene in the presence of an organic solvent is first reacted with a trivalent or higher polyhydric phenol and a monohydric phenol, and then, In one method for producing branched polycarbonate in which the reaction is completed by adding an alkaline aqueous solution, a polyhydric phenol having a benzene ring having three or more hydroxyl groups in its molecular structure is used as the trivalent or higher polyhydric phenol. , the amount of which is 0.05 to 1.5 mol% based on the total amount of dihydric phenol.
and the amount of unreacted dihydric phenol at the time of addition of the trihydric or higher polyhydric phenol is 3 moles or less per hydroxyl group of the trivalent or higher polyhydric phenol, and constitutes the reaction mixture. The volume ratio of organic phase and aqueous phase is 1:0.1~
1:1.2, and the alkaline aqueous solution subsequently added is 10 to 100 mol% based on the total amount of dihydric phenol used, and the alkali concentration is 1 to 50% by weight. Method of manufacturing polycarbonate.