JPH05178984A - Production of aromatic polyetherketone - Google Patents

Abstract

PURPOSE:To produce an arom. polyetherketone having a high degree of polymn. and a low degree of branching without causing problems of difficult handling and corrosion of a reactor arising in the conventional ketone-synthesis route and without using any expensive fluoride monomer used in the conventional ether-synthesis route. CONSTITUTION:1mol of an arom. ketone compd. having a chlorine atom and a phenolic hydroxyl group at the molecular ends is reacted with 0.9-1.015mol of an alkaline compd. having an acid group contg. phosphorus to give a phenolate, which is thermally polymerized to give an arom. polyetherketone.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved method for producing aromatic polyether ketones. More specifically, the present invention relates to a method for producing an aromatic polyether ketone having a high degree of polymerization and a small number of branched structures in a high yield by an ether synthesis route.

[0002]

2. Description of the Related Art Conventionally, general-purpose engineering plastics cannot be used because aromatic polyetherketone has a particularly low water absorption among engineering plastics and is excellent in mechanical, electrical properties and chemical resistance. It is used for applications such as electronic parts. As a method for producing this aromatic polyether ketone, a method by a ketone synthesis route and a method by an ether synthesis route are known, and in the former method by the ketone synthesis route, the aromatic polyether ketone is aromatic in an aprotic organic solvent. There are known a method of polymerizing a group carboxylic acid halide in the presence of aluminum chloride, a method of polymerizing an aromatic carboxylic acid halide in a hydrogen fluoride solvent in the presence of boron trifluoride, and the like. However, in these methods, it is necessary to use aluminum chloride or boron trifluoride, which is a Lewis acid, in an equimolar amount or more with respect to the aromatic carboxylic acid halide, which is problematic in terms of handling and equipment corrosion. There is. On the other hand, in the method by the ether synthesis route, there is known a method of polymerizing 4,4′-dihalogenobenzophenone and diphenol in the presence of an alkali. When the metal salt of phenol is prepared and during polymerization, the hydrolysis reaction of halogen is inevitable to proceed at the same time, and as a result, it is difficult to obtain a polymer having a high degree of polymerization. Further, as a method for producing an aromatic polyether ketone having a high polymerization degree from an inexpensive chloride raw material, not from an expensive fluoride raw material, an aromatic ketone compound having a chlorine atom and a phenolic hydroxyl group at a terminal and an alkali compound Japanese Patent Application Laid-Open No. 2-77423 discloses a method in which a phenolate is prepared from the above and then heated and polymerized. However, in this method, a side reaction occurs because the reaction is performed at a high temperature, and as a result, a branched structure is unavoidable in the obtained polymer, and it is difficult to obtain a polymer having sufficient mechanical properties. There is.

[0003]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventional method for producing an aromatic polyether ketone and has a high degree of polymerization and a high-performance aromatic polyether ketone having a small branched structure. The present invention has been made for the purpose of providing an industrial method for producing a high yield without any problems such as handling and equipment corrosion.

[0004]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have used an aromatic ketone compound having a chlorine atom and a phenolic hydroxyl group at a terminal as a raw material, and After preparing a phenolate with an alkali compound, when heat-polymerized to produce an aromatic polyether ketone, as an alkali compound,
Using a compound containing an acid radical containing phosphorus in a part of it,
Moreover, by using the alkali compound in a specific ratio, it was found that the object can be achieved, and the present invention has been completed based on this finding.

That is, according to the present invention, a phenolate is prepared from an aromatic ketone compound having a chlorine atom and a phenolic hydroxyl group at a terminal and an alkali compound and then heat-polymerized to produce an aromatic polyether ketone.
As the alkali compound, a compound containing an acid radical containing phosphorus as a part thereof is used, and the molar ratio of the total alkali compound to the aromatic ketone compound is 0.9 to 1.015, A method for producing a polyetherketone is provided. Hereinafter, the present invention will be described in detail. In the process of the present invention, the aromatic ketone compound having a chlorine atom and a phenolic hydroxyl group at the terminal is used as a raw material, the general formula ^{Cl-Ar 1 -CO-Ar 2} -OH ··· [1] (Ar 1 in the formula And Ar ² are respectively

[0006]

[Chemical 1]

A divalent aromatic residue represented by the following, which may be the same or different from each other,
R ¹ to R ¹² are each a hydrogen atom, a chlorine atom, an alkoxy group, a phenoxy group, an alkyl group, a cycloalkyl group, a phenyl group, an aralkyl group, an acyl group, a nitrile group, a nitro group or an acyloxy group, and Y and Z are oxygen. Atom or a ketone group, and n and m are 0 or an integer of 1 to 4).

Examples of the compound represented by the general formula [1] include 4-chloro-4'-hydroxybenzophenone, 1- (4-chlorobenzoyl) -4- (4'-hydroxybenzoyl) benzene and 4- (4-chlorophenoxy)
-4 '-(4-hydroxyphenoxy) benzophenone,
4- (4-chlorophenyl) -4'-hydroxybenzophenone, 1- (3-chlorophenoxy) -4- (4'-hydroxybenzoyl) benzene, 1- (4-chlorophenoxy) -4- (4'-hydroxy Benzoyl) benzene and the like, among which 4-chloro-4 ′ is particularly preferable.
-Hydroxybenzophenone is preferred.

The alkali compound to be reacted with the aromatic ketone compound having a chlorine atom and a phenolic hydroxyl group at the terminal thereof is not particularly limited as long as it is a compound which is dissolved in water and exhibits alkalinity. Examples of such substances include potassium hydroxide, potassium carbonate, potassium hydrogen carbonate, potassium acetate, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, sodium borate, lithium hydroxide, and the like. Particularly, potassium hydroxide is preferable.

These alkali compounds may be used alone or in combination of two or more, but in the present invention, it is necessary to use together an alkali compound containing an acid radical containing phosphorus. is there. As the alkaline compound containing an acid radical containing phosphorus, for example, phosphoric acid,
Examples thereof include alkali metal salts of phosphorous-containing acids such as phosphorous acid, biphosphoric acid, and pyrophosphoric acid. Among them, potassium phosphate is particularly preferable. The alkali compound containing an acid radical containing phosphorus may be used alone or in combination of two or more, and the addition timing may be at the time of preparing the phenolate or at the time of heat polymerization, or both of them. It may be added, but it is industrially advantageous especially when the phenolate is prepared, that is, it is charged together with the aromatic ketone compound and the alkali compound. Also,
It is desirable that the alkali compound containing an acid radical containing phosphorus is added in an amount of usually 1 to 4 parts by mole, preferably 1.5 to 3 parts by mole with respect to 100 parts by mole of the aromatic ketone compound. If this amount is less than 1 part by mole, the effect of lowering the degree of branching of the polymer will not be sufficiently exerted, and if it exceeds 4 parts by mole, the degree of polymerization will tend to decrease, such being undesirable.

The amount of the alkali compound used in the present invention is 0.9 to 1.01 in terms of the molar ratio with respect to the aromatic ketone compound, including the above-mentioned compound containing an acid radical containing phosphorus.
5, preferably 0.97 to 1.005. If this molar ratio is less than 0.9, it is difficult to obtain a high-purity phenolate unless the unreacted aromatic ketone compound is removed. If it exceeds 1.015, water remains in the produced phenolate, and When heated at a high temperature, the hydrolysis reaction is significantly promoted, and as a result, the hydrolyzate acts as a polymerization terminator, making it difficult to obtain a polymer having a high degree of polymerization.

[0012] In the present invention method, the above components are reacted in the presence of water, followed by removal of water, the general formula ^{Cl-Ar 1 -CO-Ar 2} -OM ··· [2] ( wherein (M is an alkali metal, and Ar ¹ and Ar ² have the same meanings as described above) to prepare a phenolate. At this time, it is desirable to allow an organic solvent that forms an azeotropic mixture with water (hereinafter referred to as an azeotropic solvent) to exist in the system and distill off the water azeotropically with the organic solvent. By this dehydration treatment, a trace amount of residual water is almost completely removed, side reactions are suppressed, and a phenolate of higher purity can be prepared.

The azeotropic solvent has an azeotropic temperature of 200 ° C.
Hereafter, it is preferable to use one having a temperature of 150 ° C or lower.
It is advantageous in suppressing side reactions and obtaining a high-purity phenolate. Specific examples thereof include benzene, heptane, xylene, chlorobenzene, dichlorobenzene, chloroform, acetonitrile, 1,2-dichloroethane, ethanol, dimethylsulfoxide, cyclohexane, isopropyl alcohol, 1,3-dioxane and methyl ethyl ketone. Among them, xylene is particularly preferable because it is easy to operate. The mixing ratio of the azeotropic solvent and water depends on the azeotropic composition,
It is preferable to use an azeotropic solvent in excess of the amount required to remove all water in the reaction system as an azeotrope.

The produced phenolate can be easily isolated by distilling off the azeotropic solvent under atmospheric pressure, elevated pressure or reduced pressure. The azeotropic solvent may be added before the start of the reaction or after the reaction, and the azeotropic solvent may be recovered and reused. In the method of the present invention, a polymer having a high degree of polymerization can be obtained by heat-polymerizing the extremely high-purity phenolate thus obtained in a polymerization solvent.

The polymerization solvent is preferably an aprotic solvent having a high boiling point, and examples thereof include diphenyl sulfone, ditolyl sulfone, benzophenone, diphenyl ether, diphenyl sulfoxide, dimethylaminoimidazolidinone, triethylene glycol dibutyl ether and hexamethylene phosphone. Examples thereof include acid amide, anisole, dichlorobenzene, trichlorobenzene, diphenyl and dibenzylanisole. Of these, diphenyl sulfone is preferable because it has a high boiling point and is stable.
These solvents may be used alone or in combination of two or more. The polymerization solvent may be present together with the azeotropic solvent when the phenolate is prepared.

The water content in the phenolate is 0.5 mol%
Below, it is desirable to set the content to 0.3 mol% or less, but in order to achieve more complete dehydration, for example, azeotropic distillation is again carried out using an azeotropic solvent, or Grignard reagent, diborane, organoaluminum, pentoxide. A method using a dehydratable reagent having high reactivity with water, such as phosphorus or an organozinc compound, can be used. By such dehydration treatment, the trace amount of residual water is almost completely removed, the side reaction is completely suppressed, and a higher-purity phenolate is obtained. Therefore, the subsequent polymerization reaction causes
A polymer having an extremely high degree of polymerization can be obtained.

The polymerization reaction generally has a polymer concentration of 1 to 50% by weight, preferably 3 to 40% by weight, and an atmospheric pressure of 200 to 200%.
It is carried out at a temperature in the range of 400 ° C., preferably 250 to 380 ° C., more preferably 270 to 370 ° C., but it can also be carried out under pressure. The reaction time depends on other conditions and cannot be determined unconditionally, but usually 0.5 to 3
It is selected in the range of 6 hours, preferably 1.5 to 24 hours. This polymerization reaction proceeds without using a catalyst, but a copper compound such as copper halide can be used as a catalyst.

[0018]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. In addition, confirmation of the phenolation was carried out by collecting a part of the obtained solid matter, ultrasonically washing this in the presence of water, collecting the solid matter by filtration, and drying it at 120 ° C. under reduced pressure overnight. The obtained white powder is trimethylsilylated in a pyridine solution, and the amount of unreacted trimethylsilylated product is determined by gas chromatography. Further, the fact that the chlorine atom in this phenolate is not hydrolyzed is confirmed by gas chromatography, by trimethylsilylating the diphenol compound and examining the presence or absence of the trimethylsilyl compound. In the case of the trimethylsilylated compound of the compound of the general formula [1], the gas chromatograph method uses a column of SE-30 5% 2m manufactured by Gaskuro Kogyo Co., Ltd. at an inlet temperature of 250 ° C. and a column temperature of 200 ° C. In the case of the trimethylsilylated product of the diphenol compound, a column of XE-60 2% 1 m manufactured by Gascro Industrial Co., Ltd. was used, the inlet temperature was 250 ° C, and the column temperature was from 80 ° C to 2 ° C.
It was determined by raising the temperature to 30 ° C. at a rate of 5 ° C./min.

Examples 1-3, Comparative Examples 1-3 21.75 g (93.93.) Of 4-chloro-4'-hydroxybenzophenone was placed in a reactor equipped with a stirrer, nitrogen inlet, thermocouple inlet and distillation apparatus. (5 mmol) and the amounts of potassium phosphate and 2N-potassium hydroxide described in Table 1 were introduced, and the phenolating reaction was carried out by stirring at room temperature for 30 minutes while introducing dry nitrogen at a flow rate of 400 ml / min. It was 140 ml of xylene was added to the obtained yellow transparent reaction solution,
Azeotropic distillation was carried out for 1.5 hours to remove water and xylene. The mixture is heated for 30 minutes to remove the remaining xylene and a small amount of residual water, and when the internal temperature reaches 280 ° C., the reaction is stopped to give a yellow powder of potassium salt of 4-chloro-4′-hydroxybenzophenone. Obtained. This potassium salt of 4-chloro-4'-hydroxybenzophenone 21.3
1g of water was previously dehydrated with molecular sieves
Mix with 18.0 ppm of diphenyl sulfone (47.08 g), heat-treat at 280 ° C. for 2 hours under a nitrogen stream, and then at 320 ° C.
The mixture was stirred for 4 hours to carry out a polymerization reaction. The powder obtained by cooling and pulverizing the polymerization reaction mixture was washed three times with acetone, 2 times each.
After refluxing for 0 minutes for washing, diphenyl sulfone was removed, then washed twice with hot water, and then vacuum dried at 120 ° C. for 12 hours to obtain a polyether ketone. The logarithmic viscosity and degree of branching structure of the obtained polymer are shown in Table 1. The logarithmic viscosity is 30% in concentrated sulfuric acid (specific gravity 1.84).
It is a value measured at 0 ° C. and a polymer concentration of 1.0 g / dl. As a measure of the branched structure, the absorption of a polymer in a sulfuric acid solution at 550 nm (Abs550) was quantified with a spectrophotometer ["Polymer", Vol. 22, page 1096 (1981)].

[0020]

[Table 1]

Note 1) CHBP: 4-chloro-4'-hydroxybenzophenone As can be seen from Table 1, the polymer obtained by the method of the present invention has a lower degree of branching than that of the comparative example.

[0022]

According to the present invention, an aromatic polyether ketone having a high degree of polymerization and a small number of branched structures can be obtained without any problem in handling the reactants in the conventional ketone synthesis route or corrosion in the reactor. It can be produced in high yield without using an expensive fluoride monomer in the conventional ether synthesis route. Therefore, it can be said that the method of the present invention is an industrially extremely advantageous method for producing an aromatic polyether ketone having a high degree of polymerization.

Claims (1)

[Claims] 1. A method for preparing a phenolate from an aromatic ketone compound having a chlorine atom and a phenolic hydroxyl group at a terminal and an alkali compound and then heat-polymerizing the phenolate to produce an aromatic polyether ketone. A method for producing an aromatic polyether ketone, characterized in that a compound containing an acid group partially containing phosphorus is used, and the molar ratio of the total alkali compound to the aromatic ketone compound is 0.9 to 1.015. .