JPS63183925A - Production of polycarbonate - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate having high fluidity of a molten resin, excellent moldability and good heat resistance, by reacting an organic dihydroxy compound with phosgene in the presence of a specific molecular weight modifier in a liquid medium. CONSTITUTION:An organic dihydroxy compound, preferably bisphenol A is reacted with phosgene in the presence of a monofunctional organic compound expressed by the formula R-COX (R is 8-20C branched alkyl; X is halogen or OH) as a molecular weight modifier in a liquid medium to afford the aimed polycarbonate. A method for reacting organic diols dissolved in an aqueous solution of an alkali with phosgene in the presence of an inert organic solvent, adding the molecular weight modifier before or in the reaction and carrying out interfacial polymerization in the presence of a tertiary amine as a polymerization catalyst after completing the reaction is cited as the preferred polymerization method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method for producing a polycarbonate resin in which the molten resin has high fluidity and therefore has good moldability.

[Prior art 1] Polycarbonate is generally produced by the reaction of an organic dihydroxy compound and phosgene, and is known as an engineering plastic with excellent heat resistance and mechanical strength. However, due to the high melt viscosity of the resin, To obtain fluidity of molten resin during molding process, use polycarbonate) +
It must be heated to a high temperature close to the decomposition temperature of 34 fat to form it.

Particularly when molding thin-walled products or molding complex shapes, molding is often impossible due to insufficient flow of resin even at temperatures close to the decomposition temperature of the resin. Due to overheating, brown spots of decomposition products occur, causing poor appearance of molded products.

In order to solve this situation, methods of adding plasticizers and methods of using specific molecular weight regulators (Japanese Patent Publication No. 52-50078) have been proposed as means for improving the fluidity of polycarbonate during molding. Already proposed.

The method of adding a plasticizer improves fluidity, but plasticizer vapor with a strange odor is generated during molding, impairing the working environment. It has the disadvantage that it is transferred onto the surface of the molded product, resulting in poor appearance of the product.

On the other hand, the method of using a specific molecular weight regulator uses a monofunctional organic compound having a linear aliphatic group with a specific range of carbon atoms in the polycarbonate production reaction system, adjusts the molecular weight, and adjusts the molecular weight of the polycarbonate. The fluidity of polycarbonate is improved by adding the molecular weight modifier to the end of the main chain of the molecule, and although this product has improved fluidity, it has the disadvantage of decreased heat resistance.

[Problem to be Solved by the Invention 1] The present invention provides the above-mentioned method of adding a specific molecular weight regulator to the end of the main chain of polycarbonate in order to solve the difficult situation of the trade-off that increasing fluidity generally reduces heat resistance. An object of the present invention is to provide a method for producing polycarbonate that improves fluidity while maintaining heat resistance.

[Means for Solving the Problems 1] As a result of various studies on molecular weight modifiers used in the production of polycarbonate, the present inventors found that monofunctional fatty acids or acid halides having branched alkyl groups were used in the polymerization of polycarbonate. The present inventors have discovered that when added to the reaction system as a molecular weight regulator, fluidity can be improved without deteriorating heat resistance, and the present invention has been completed. .

That is, in the present invention, in producing polycarbonate by reacting a dihydroxy compound and phosgene in the presence of a molecular weight regulator in a liquid medium, the molecular weight regulator is a compound of the formula (wherein R is a branched is an alkyl group,
The present invention provides a method for producing polycarbonate characterized by using a monofunctional organic compound represented by the formula (X is a halogen atom or a hydroxyl group).

Any organic dihydroxy compound used as a raw material in the present invention can be used as long as it produces polycarbonate by reaction with phosgene. Examples include aromatic dihydroxy compounds, aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, etc. However, aromatic dihydroxy compounds, particularly bisphenol A, etc. can be used preferably. In addition, since polycarbonate is generally not crystalline, its physical properties do not deteriorate even if it is made into a copolymer. Therefore, a method of adjusting the physical properties of a polymer by forming a copolymer of two or more dihydroxy compounds is commonly used. In the present invention, a copolymer using two or more of these organic dihydroxy compounds is also used, for example, by adding another aromatic dihydroxy compound or an aliphatic or alicyclic dihydroxy compound to the aromatic dihydroxy compound as a raw material. of polycarbonate can be produced.

Examples of the aromatic dihydroxy compound as a raw material for the polycarbonate of the present invention include bis-(4-hydroxyphenyl)methane, 1,1-bis-(4-hydroxyphenyl)ethane, 1,1-bis-(4-hydroxyphenyl) )
Furopane, 2,2-bis-(4-hydroxyphenyl)
Propane, (hereinafter referred to as "bisphenol A"), 2
．． 2-bis-(4-hydroxyphenyl)butane, 2,
2-bis-(4-hydroxyphenyl)pentane, 2,
2-bis-(4-hydroxyphenyl)inpentane,
2.2-bis-(4-hydroxyphenyl)hexane,
2.2-bis-(4-hydroxyphenyl)inhexane, 4,4-dihydroxytriphenylmethane, 4,4
-dihydroxytetraphenylmethane, 1,1-bis-
(4-hydroxyphenyl)cyclohexane, 2,2-
Bis=(4,4-hydroxy-3-methylphenyl)propane, 2,2-bis=(4,4-hydroxy-3,5
- Bisphenols such as dimethylphenyl)propane, dihydroxydiphenyletenopenohydroxydiphenylsulfone, dihydroxydiphenylsulfide, di(4-hydroxyphenyl)diphenylmethane, di(4-hydroxyphenyl)di(4-methylphenyl)methane, hydroquinone, and resorcinol. , 0-methylresorcinol, 0-cumylresorcinol, and the like, and bisphenol A is a particularly preferable aromatic diol.

Examples of the aliphatic dihydroxy compound of the present invention include trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol,
Decamethylene glycol, diethylene glycol, etc. can be used alone or together with an aromatic dihydroxy compound.

As the alicyclic dihydroxy compound of the present invention, for example, 1
．． Hydrogenated products of aromatic rings of the above-mentioned aromatic dihydroxy compounds including 4-dihydroxycyclohexane can be used.

The molecular weight regulator used in the present invention is a fatty acid or acid halide having a branched alkyl group having 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms.

Those with carbon number less than 8 have little improvement in fluidity;
When the number of carbon atoms exceeds 20, heat resistance decreases.

Such fatty acids or acid halides having branched alkyl include, for example, trimethylhexanoic acid, triethylhexanoic acid, diethylhexanoic acid, ethylhexanoic acid, methylethylhexanoic acid, trimethylheptanoic acid, triethylhebutanoic acid, and diethylhexanoic acid. Butanoic acid, hexyldecanoic acid, for example, valeric acid (C5), hexanoic acid (C6), heptanoic acid (C2), octanoic acid (C8
), nonanoic acid (C8), decanoic acid (C,,), undecanoic acid (C,,), lauric acid (C,2), myristic acid (C,,), palmitic acid (C,,), etc. Carboxylic acids having a structure in which a chain carboxylic acid has one or more linear or branched alkyl groups having 1 to 6 carbon atoms as a side chain, and acid halides thereof can be used. Furthermore, in the present invention, two or more of these molecular weight regulators can be used in combination.

The polycarbonate of the present invention can be produced by any known method such as a conventional polycarbonate production method, such as an interfacial polymerization method or a pyridine method.

For example, in the presence of an inert organic solvent, an organic diol dissolved in an alkaline aqueous solution is reacted with phosgene, a molecular weight regulator is added before or during the reaction, and after the reaction is completed, a tertiary amine as a polymerization catalyst is reacted. An interfacial polymerization method in which polycarbonate resin is obtained by interfacial polymerization, and organic diols and a molecular weight regulator are dissolved in a mixed solvent of pyrinone or pyridine and an inert solvent, and phosgene is blown into this solution to directly produce polycarbonate (tfi?). A pyridine polymerization method for obtaining fat can be suitably employed as a polymerization method for the polycarbonate of the present invention.

The obtained resin can be purified by a conventional method by subjecting it to neutralization and washing steps, or by precipitation using a poor solvent such as alcohol or ketone.

In the polycarbonate obtained by the present invention, the molecular weight regulator having a branched alkyl group of the present invention is bonded to both ends of almost all of the polymer molecules. A method for producing novel polycarbonates is provided.

The fluidity of the molten resin during molding of the polycarbonate resin obtained by the present invention is as follows, if the molecular weight is the same:
It is determined by the structure of the polymer terminal group, that is, the type of branched alkyl group contained in the molecular weight regulator used during production.

Polycarbonate resins having desired fluidity and heat resistance can be produced by various combinations of the types of branched furkyl groups in the molecular weight modifier and the amounts added thereof.

[Effect of the invention] The polycarbonate resin obtained by the production method of the present invention is
Compared to conventional products produced by adding a molecular weight modifier having a linear alkyl group having 8 to 20 carbon atoms, the degree of improvement in fluidity is the same, but the heat resistance is good.

As a result, it becomes possible to manufacture thin-walled molded products and molded products with complex structures, and there is also the advantage that the molding cycle can be shortened even in the case of ordinary molded products.

Furthermore, since no plasticizer is used, it is advantageous because it does not impair the working environment and does not cause defects in the appearance of the product.

[Example 1゛ The present invention will be explained in more detail with reference to Examples.

Example 1 43.2 g of sodium hydroxide was dissolved in 530 g of water, and while keeping the temperature at 20°C, 91.9 g of bisphenol A was added.
2f, hydrosulfide O, and Ig were dissolved.

To this, 325 g of methylene chloride was added, and while stirring, 2.37 g of 3,5.5-)limethylhexanoic acid was added, and then phosgene 41FI was blown in over 60 minutes. After the blowing of phosgene was completed, the mixture was vigorously stirred to emulsify the reaction solution. After emulsification, 0.1 g of triethylamine was added, and stirring was continued for about 1 hour for polymerization.

An aqueous layer and an organic layer were separated from this polymerization liquid, and the organic layer was neutralized with phosphoric acid. After repeating water washing until pt+ of the washing liquid became neutral, 400 g of isopropanol was added to precipitate the polymer. The precipitate was filtered and vacuum dried at 50°C to obtain a white powder polycarbonate.

Next, this polycarbonate was melted at 300°C and a diameter of 2
It was extruded through the n pores to form a transparent strand, which was then shredded to obtain polycarbonate chips.

The average molecular weight determined from the intrinsic viscosity of a methylene chloride solution of this polymer, the flow value measured using a Koka type flow tester, and the heat distortion temperature measured using a compression molded piece are shown in Table 1.

Example 2 In Example 1, instead of using 3,5.5-)limethylhexanoic acid, 3.84 g of 2-hexyldecanoic acid was used.
Chip-shaped polycarbonate was obtained by processing in the same manner as in Example 1 except that .

Table 1 shows the physical properties of this polymer.

Example 3 Example 1 except that 2.64 g of 3,5.5-)limethylhexanoic acid chloride was used instead of 3,5.5-)limethylhexanoic acid in Example 1. Polycarbonate chips were obtained in the same manner as above.

Table 1 shows the physical properties of this polymer.

Comparative Example 1 43.2g of sodium hydroxide was dissolved in 530g of water and 0°C
While keeping the temperature at
g was injected in 60 minutes. After the blowing of phosgene was completed, the reaction solution was vigorously stirred to emulsify it, and after emulsification, 0.1 g of triethylamine was added, and stirring was continued for about 1 hour for polymerization. An aqueous layer and an organic layer were separated from the polymerization solution, and the organic layer was neutralized with phosphoric acid. After repeated washing with water until the pi of the washing liquid became neutral, isopropanol 400FI was added to precipitate the polymer. The precipitate was filtered and vacuum dried at 50°C to obtain a white powder polycarbonate. Next, this polycarbonate was melted at 300° C. and extruded through a pore with a diameter of 2 U to form a transparent strand, which was then shredded to obtain polycarbonate in the form of chips.

The average molecular weight determined from the intrinsic viscosity of a methylene chloride solution of this polymer, the flow value determined using a Koka type flow tester, and the heat distortion temperature measured using a compression molded piece are shown in Table 1.

Comparative Example 2 To bisphenol 91.2g of bisphenol was dissolved in a mixed solvent of 100g of pyridine and 600g of methylene chloride, and propionic acid chloride 1,4. added. While maintaining the temperature at 20° C. and stirring, phosgene 40FI was blown in over 90 minutes. 400
After diluting the solution by adding 1 g of methylene chloride, 1
700 g of 0% aqueous hydrochloric acid solution was added and stirred vigorously for 15 minutes.

The aqueous layer and the organic layer were separated, and the organic layer was washed with water repeatedly until the p++ of the washing liquid became neutral. After washing with water, the aqueous layer was again separated using a centrifuge. After adding methanol to the organic layer to precipitate a polymer, a chip-shaped polycarbonate resin is obtained in the same manner as in Comparative Example 1.

The physical properties of this polymer are shown in Table 1.

Comparative Example 3 91.2 g of bisphenol^, 100 g of 2-pyridine,
Methylene chloride 600. Dissolved in a mixed solvent of and further added 50! ? 1.95 g of caproic acid dissolved in methylene chloride was added. While maintaining the temperature at 20° C. and stirring, 40 g of phosgene was blown into the solution over 90 minutes. After diluting the solution by adding 400 g of methylene chloride, 700 g of a 10% aqueous hydrochloric acid solution was added and vigorously mixed for 15 minutes. The aqueous layer and the organic layer were separated, and the organic layer was washed repeatedly with water until the pH of the washing liquid became neutral. After washing with water, the aqueous layer was separated again using a centrifuge. After adding methanol to the organic layer to precipitate a polymer, the same procedure as in Comparative Example 1 is carried out to obtain polycarbonate resin chips.

The physical properties of this polymer are shown in Table 1.

Comparative Example 4 Sodium hydroxide 43.2. Dissolve in 530g of water, 2
While keeping it at 0℃, add 91.2g of bisphenol A.
0.1 g of hydrosulfide was dissolved. Add 325 g of methylene chloride to this, add 4.13 g of balmitic acid chloride while stirring, and then add 41 g of phosgene.
was injected in 60 minutes.

After completing the phosdene injection, stir vigorously to emulsify the reaction solution.
0 after emulsification. Ig of triethylamine was added, and stirring was continued for about 1 hour to allow polymerization. Thereafter, the same process as in Comparative Example 1 was carried out to obtain chip-shaped polycarbonate. The physical properties of this polymer are shown in Table 1.

From the results in Table 1, the molecular weights of the polycarbonates obtained here are controlled to be almost the same, and when a molecular weight modifier having a furkyl group with less than 8 carbon atoms is used, the heat resistance is high, but the fluidity is low. It can be seen that when palmitic acid chloride having a low carbon alkyl group and a linear alkyl group having 8 to 20 carbon atoms is used as a molecular weight regulator, the fluidity is improved but the heat resistance is significantly lowered.

On the other hand, it can be seen that the polycarbonate resin of the present invention using a molecular weight modifier having a branched alkyl group has improved fluidity while maintaining heat resistance.

Claims (1)

[Scope of Claims] 1. In producing polycarbonate by reacting an organic dihydroxy compound and phosgene in the presence of a molecular weight regulator in a liquid medium, the formula R-COX (wherein R is the number of carbon atoms) is used as the molecular weight regulator. 8 to 20 branched alkyl groups,
A method for producing polycarbonate, characterized in that a monofunctional organic compound represented by X is a halogen atom or a hydroxyl group is used.