JPS5818392B2 - Nannenka Polycarbonate Materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to flame-retardant polycarbonate compositions with enhanced flowability.

In order to obtain a flame-retardant polycarbonate, it is known to mix bisphenol A with halogenated bisphenol A such as tetrabromobisphenol A, and to react with phosgene to obtain a copolymerized polycarbonate.

However, the major drawbacks of such flame-retardant copolymerized polycarbonates are that they have poor fluidity and are difficult to mold.

The present inventors have attempted to overcome these shortcomings in the conventional methods (as a result of extensive research), we have found that polycarbonates made from bisphenol 8, tetrahalogen, z-4, 4'-
We have discovered that by mixing a copolymerized polycarbonate made from dioxydiphenyl sulfone and bisphenol A, it is possible to easily obtain a high-quality polycarbonate composition that has excellent flame retardancy and excellent fluidity, and has developed this book. He has completed his invention.

In the composition of the present invention, the copolymerized polycarbonate used as the flame retardant component is a polycarbonate oligomer obtained by reacting bisphenol A and phosgene.
Tetrahalogeno-4,4'-dioxydiphenylsulfone or bisphenol A and tetrahalogeno-4,4'
- dioxydiphenyl sulfone in the presence of a tertiary amine.

The polycarbonate oligomer used in this method is prepared by, for example, blowing hephosgene into a mixture of bisphenol A and methylene chloride dissolved in an aqueous sodium hydroxide solution, and introducing phosgene when the pH reaches a range of 9 to 12. It can be obtained as a methylene chloride solution by stopping the reaction and separating the aqueous layer and the organic layer by standing.

At this time, by appropriately controlling the reaction conditions, the molecular weight of the oligomer and the ratio of hydroxyl groups to chloroformate groups in the molecule can be adjusted as desired.

Further, as a catalyst for this method, tertiary amines such as trimethylamine, triethylamine, tripropylamine, and tributylamine are used.

Although the reaction proceeds with quaternary ammonium salts, the reaction rate is very slow (and thus impractical).

In the method of the present invention, a molecular weight regulator may be used in combination if necessary. Examples of the molecular weight regulator include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and methyl alcohol, phenol, cresol,
Phenols such as butylphenol are suitable.

The reaction to obtain the flame-retardant copolycarbonate is advantageously carried out in an organic solvent capable of dissolving the polycarbonate oligomer and the polycarbonate produced.

Examples of such solvents include chlorinated hydrocarbons such as methylene chloride, ethane tetrachloride, 1.2-dichloroethane, chloroform, trichloroethane, dichloroethane, and chlorobenzene, dioxane, tetrahydrofuran, and acetophenone.

In order to suitably produce this copolymerized polycarbonate, a tubular reactor is used, and an alkaline aqueous solution of bisphenol A and an organic solvent for polycarbonate are continuously introduced into the reactor to form a multiphase flow. Phosgene is injected and reacted with an external cooler while bringing it into cocurrent contact.

When the reaction is carried out in this way, the multiphase flow formed inside becomes a spray flow due to the reaction heat caused by the injection of phosgene.
Since contact with phosgene occurs in the state of this spray flow, phosgene reacts in almost the stoichiometric amount, and the reaction is completed in an extremely short time.

In addition, due to the reaction heat generated at this time, a part of the organic solvent is vaporized and becomes vapor, and on the other hand, the solvent in which the oligomer is dissolved and the aqueous solution containing alkali chloride become atomized, but these are removed from the reaction tube by external cooling. It gradually condenses toward the outlet, and is finally taken out as a two-liquid multiphase flow consisting of an organic layer containing oligomers, an aqueous layer containing alkali chloride, and the remaining alkali.

This product can be separated into two phases by allowing it to stand for a while.

Introducing phosgene into a multiphase flow of an alkaline aqueous solution of bisphenol A and an organic solvent can be carried out using a single inlet, but it is not possible to slow down the progress of local reactions in large equipment. It is advantageous to use two or more inlets to avoid waste of phosgene.

For the above-mentioned tubular reactor, the length of the tube should be sufficiently long compared to the tube diameter (for example, tube length/tube diameter) so that the vaporized solvent can be completely condensed and the generated oligomer can be completely dissolved in the solvent. In addition, a jacket or cooling tank is attached to the outside of the tube to enable external cooling.

In this way, oligomers having a stable molecular weight range can be continuously obtained by operating the tubular reactor under predetermined reaction conditions.

For example, by reacting bisphenol A and phosgene in a methylene chloride solvent and maintaining the final reaction product in a slightly alkaline state, oligomers having a molecular weight of 450 to 500 can be obtained with good reproducibility.

Next, the oligomer thus obtained is treated with a catalyst such as tetrahalogeno-4,4'-dioxydiphenylsulfone or a mixture of bisphenol A and tetrahalogeno-4,4'-dioxydiphenylsulfone in an alkaline aqueous solution. triamine and optionally a molecular weight modifier,
For example, a branched alkyl-substituted phenol is added, externally cooled, and reacted with stirring.

In this way, thermally stable flame-retardant polycarbonate can be efficiently produced.

According to this method, tetrahyloge for oligomers)
- Usage ratio of 4,4'-dioxydiphenyl sulfone,
Or bisphenol A and tetrahalogeno-4.47
By changing the mixing ratio with -dioxydiphenylsulfone, the amount of halogen introduced into the target product can be adjusted as appropriate, and a polycarbonate having a halogen content of 30% or less can be obtained as desired.

Furthermore, when producing the copolymerized polycarbonate,
It is not necessarily necessary to react via an oligomer, and phosgene can also be reacted directly with a mixture of bisphenol A and tetrahalogeno-4,4'-dioxydiphenylsulfone.

The composition of the present invention can be obtained by mixing such a copolymerized polycarbonate with a polycarbonate obtained by the reaction of bisphenol A and phosgene. A method of mixing or a method of mixing both in a molten state using an extruder or the like can be adopted.

In addition, the mixing ratio of both varies depending on the halogen content of the copolymerized polycarbonate, but in general, the copolymerized polycarbonate has a halogen content of 3% by weight in the composition.
, preferably in a proportion of 5% by weight or more.

The composition of the present invention has excellent flame retardancy and high fluidity, so it can be easily molded and used for mechanical parts, electrical parts, etc.
Suitable as a molding material for building materials, miscellaneous goods, etc.

Next, the present invention will be explained in more detail with reference to Examples.

Example Inner volume 1 with stirrer, thermometer and reflux condenser installed
50,077 Il of a 1.7 N aqueous sodium hydroxide solution was charged into a separable flask of 1.5 m, and bisphenol A91P was added thereto and dissolved, and then 200 l of methylene chloride was added.
Add 11Ll and add 40L of phosgene while stirring.
Blowing was performed at a flow rate of y'/hour.

In this case, cool the flask from the outside to bring the reaction temperature to 20
It was kept at ℃.

After 95 minutes, the pH after the reaction became 11.5, and at this point, the blowing of phosgene and stirring were stopped, and the reaction solution was separated into two layers by standing still.

The upper layer was an aqueous solution containing sodium chloride, which was removed by tecantation to obtain a methylene chloride solution of bisphenol A polycarbonate oligomer.

This solution contained 0.39 g equivalent of chloroformate groups.

Next, add 250 m of methylene chloride to this oligomer solution.
To this diluted solution, add 3,3',5,5' to tetrabromo-4,4'-dioxydiphenylsulfone 3 to 160 ml of 2.0N aqueous sodium hydroxide solution.
4g and bisphenol A2. solution of l', 4
8% sodium hydroxide aqueous solution 18.0ru1. p-t
-butylphenol 4.6f and tri-n-butylamine o, i'fI were added and stirred for 90 minutes while maintaining the temperature at 30°C.

This operation allows the chloroformate group to completely react,
A viscous emulsion solution was obtained.

This solution was diluted with methylene chloride to give a polymer concentration of 7% and washed with water until no inorganic salts were present. A transparent methylene chloride solution of the copolymerized polycarbonate was obtained.

This was precipitated in methyl alcohol, the resulting polymer powder was dried, and the bromine content was measured to be 11.0%.
Met.

Furthermore, the intrinsic viscosity of the polymer in methylene chloride at 20°C is 0.0494. l/? Q available, JISK-671
The flow value measured according to 9-69 is 0, 24 rul/
It was sec.

Intrinsic viscosity 0.0501t/g, flow value 0.105m1/
sec bisphenol A polycarbonate and the above copolymerized polycarbonate were mixed in a solution state and precipitated with methyl alcohol to obtain a powder mixture.

The mixing ratio is 30 parts of bisphenol A polycarbonate to 100 parts of copolymer.

The bromine content in the powder mixture is 8.5%, and the intrinsic viscosity is 0.
0498t7L? , the flow value is 0.225 ml/se
c, and the fluidity was good.

This mixed powder was melted at 265° C. using a melt indexer and extruded into a rod (diameter: 2 mm), and its oxygen index was measured to be 36%.

Similarly, when the oxygen index of bisphenol A polycarbonate was measured, it was 24.5%, indicating a significant improvement in flame retardancy.

Reference example Intrinsic viscosity 0.0399t/g, flow value 0.01.95m
1:/see, copolymer of tetrabromobisphenol A and bisphenol A with a bromine content of 15.6% 10
Intrinsic viscosity 0.0501 t/? , flow value 0
．． 84 parts of bisphenol A polycarbonate (105 ml/see) was similarly mixed in a solution state and precipitated with methyl alcohol to obtain a powder mixture.

The intrinsic viscosity of this mixture is 0.0445 t/? , the flow value was 0,0302 ml/sec, indicating low fluidity despite the low intrinsic viscosity.

The oxygen index of this mixture was measured in the same manner as in the examples and was found to be 33%.

Claims (1)

[Claims] 1 Polycarbonate (a) from bisphenol A, copolymerized polycarbonate of tetrahalogeno-4,4'-dioxydiphenyl sulfone and bisphenol A)
A flame-retardant polycarbonate composition comprising (b).