JPH0527648B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to an improved method for producing crystalline aromatic polyetherketones. More specifically, the present invention provides an industrially advantageous method for producing a high-molecular-weight, highly crystalline aromatic polyetherketone with excellent heat resistance, chemical resistance, mechanical strength, etc. using a specific reaction solvent. It is related to. Prior Art In recent years, crystalline aromatic polyetherketones in which phenylene groups are linked via ether groups and keto groups have been used for molding in various fields because they have excellent heat resistance, chemical resistance, mechanical strength, etc. It is attracting attention as a material. As a method for producing this aromatic polyether ketone, for example, a dialkali metal salt of bisphenol containing a keto group and a dihalogeno compound containing a keto group are heated at 250 to 400°C in the presence of an aromatic sulfone.
(Japanese Patent Publication No. 57-22938), a halophenol containing a keto group is heated with an alkali metal carbonate in N-methylpyrrolidone, an aliphatic sulfone, or an aromatic sulfone compound at
Method of heating to a temperature of 400°C (US Patent No. 4113699)
No. 1 specification), etc. are known. By the way, in order to produce a high molecular weight polymer, it is generally necessary to proceed with the reaction in a polymerization medium that dissolves the produced polymer, but in the case of crystalline aromatic polyether ketone, this is not possible. Insoluble at low temperatures in polymerization media such as 300℃
Polymerization must be carried out at high temperatures, such as: Therefore, in a method for producing a high molecular weight crystalline aromatic polyetherketone, it is important to select a polymerization solvent that is stable even at high temperatures and has appropriate polarity. Conventionally, as mentioned above, aliphatic sulfones, aromatic sulfones, N
-Methylpyrrolidone etc. are used, but even if aromatic sulfone is used, a long reaction time is required at high temperature especially when the purpose is to obtain a polymer with high crystallinity and high melting point. N-methylpyrrolidone and aliphatic sulfones such as sulfolane are thermally unstable, and their ability as polymerization solvents is inferior to that of aromatic sulfones. Because of their inferiority, it has been difficult to obtain a high molecular weight, highly crystalline aromatic polyether ketone even if these are used. Problems to be Solved by the Invention The first object of the present invention is to provide an improved production method for obtaining a high molecular weight, highly crystalline aromatic polyether ketone having excellent heat resistance, chemical resistance, mechanical strength, etc. The present invention provides a method. A second object of the present invention is a method for easily producing a high-molecular-weight, highly crystalline aromatic polyetherketone by using a specific polymerization solvent that is stable at high temperatures and has appropriate polarity. The goal is to provide the following. Means for Solving the Problems The present inventors can achieve the objective by using a certain type of xanthone compound or thioxanthone compound as a polymerization solvent when producing a crystalline aromatic polyether ketone. Based on this finding, we have accomplished the present invention. That is, the present invention involves condensation polymerization of at least one aromatic dihydroxy compound component and at least one dihalogeno aromatic ketone component, or at least one monohydroxy monohalogeno aromatic ketone component, in a solvent. When producing crystalline aromatic polyetherketone by condensation polymerization, as a solvent, the general formula (R and R' in the formula are each a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group,
These may be the same or different, and Y is an oxygen atom or a sulfur atom. This is what we provide. In the condensation polymerization reaction in the method of the present invention, for example, an aromatic dihizoloxy compound having a free hydroxyl group is used as a component having a free hydroxyl group, and a substantially equimolar mixture of this and a dihalogeno aromatic ketone component is Heating in the presence of an alkali in a predetermined solvent, or heating a substantially equimolar mixture of the alkali metal salt thereof as an aromatic dihydroxy compound component and a dihalogeno aromatic ketone in a predetermined solvent. Alternatively, a monohydroxymonohalogenoaromatic ketone having a free hydroxyl group is used and heated in a predetermined solvent in the presence of an alkali, or an alkali salt of a monohydroxymonohalogenoaromatic ketone is used. This can be done by heating it in a predetermined solvent. The aromatic dihydroxy compound component used as a raw material in the method of the present invention includes a dihydric phenol represented by the general formula HO-Ar-OH () (Ar is an aromatic residue) and its alkali salt. Examples of these include mononuclear divalent phenols such as hydroquinone, dihydroxy polyphenyl such as 4,4'-dihydroxybiphenyl, and 1,1-bis(4-hydroxyphenyl).
Propane, bis(4-hydroxyphenyl)methane, 4,4'-dihydroxyenzophenone, 4,
4'-dihydroxydiphenyl ether, 4,4'-
Examples include bisphenols such as dihydroxydiphenyl sulfide, nuclear substituted products thereof, and alkali salts thereof. This alkali salt is obtained by reacting the divalent phenol of the general formula () with an alkali such as an alkali metal hydroxide according to a conventional method. Particularly preferred among such aromatic dihydroxy compound components are hydroquinone, 4,4'-dihydroxybenzophenone, and alkali metal salts thereof. These dihydric phenols or alkali salts thereof may be used alone or in a mixture of two or more. Next, the dihalogeno aromatic ketone component to be condensed with this aromatic dihydroxy compound component is as follows:
For example, the general formula A dihalogenobenzenoid compound represented by (which is a bonded halogen atom) is used. Among such dihalobenzenoid compounds,
Preferably, the general formula (X has the same meaning as above, Z is an ether group,
Examples include compounds represented by a thioether group, a carbonyl group, a sulfone group, or a divalent alkylene group, x and y are integers of 1 to 3. Examples of such compounds include 4,4'-difluorobenduphenone, 2,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, and bis-1,4-(4- fluorobenzoyl) benzene,
Bis-1,3-(4-chlorobenzoyl)benzene, bis-1,4-(4-chlorobenzoyl)benzene, bis-4,4'-(4-chlorobenzoyl)
Biphenyl, bis-4,4'-(4-chlorobenzoyl) diphenyl ether, and the like. These dihalogeno aromatic ketones may be used alone or in combination of two or more. Among the dihalobenzenoid compounds of the general formula (), those in which the halogen atom is bonded to the para position relative to the bonding position of the keto group are particularly preferred in order to obtain a polymer with a high melting point and high crystallinity. It's advantageous. Particularly preferred are 4,4'-dihalobenzophenone and bis-1,4-(4-halobenzoyl)benzene. Next, the monohydroxymonohalogeno aromatic ketone component used as a raw material for another method is, for example, represented by the general formula: There are halophenols and their alkali salts containing at least one benzophenone unit. An example of such is 4-fluoro-
4'-Hydroxybenzophenone, 4-chloro-
4'-Hydroxybenzophenone, 4-(4-fluorobenzoyl)-4'-hydroxybiphenyl, 4
-(4-fluorobenzoyl)-4'-hydroxydiphenyl ether and the like. Further, the alkali salt of halfphenol used in the present invention can be obtained by a known method, for example, the method of reacting halfphenol with an alkali metal hydroxide as described above. These halophenols or alkali salts thereof may be used alone or in combination of two or more. Among the halophenols or alkali salts thereof, those particularly preferably used are 4-halo-
4'-hydroxybenzophenone or its alkali metal salt. In the method of the present invention, the general formula It is necessary to use a xanthone compound or a thioxanthone compound represented by (R, R' in the formula have the same meanings as above). Examples of such compounds include xanthone, thioxanthone, 2-phenylxanthone, 2-phenylthioxanthone, 2-methylxanthone, 2-methylthioxanthone, and 1,3-dimethylxanthone. Particularly preferred among these are xanthone and thioxinthone. These solvents may be used alone or in combination of two or more. Furthermore, if desired, it can be used in combination with other solvents within a range that does not impair the purpose of the present invention. In the method of the present invention, when the dihydric phenol of the general formula () is used as the aromatic dihydroxy compound component, or when the halophenol of the general formula () is used as the monohydroxy monohalogeno aromatic ketone component, It is necessary to carry out the reaction in the presence of an alkali. As this alkali, for example, alkali metal hydroxides, carbonates, bicarbonates, fluorides, hydrides, alkoxides, alkylated products, etc. are used. According to the method of the present invention, when the dihydric phenol of the general formula () and the dihalogenobenzenoid of the general formula () are condensed, the general formula ()
A predetermined amount of dihydric phenol, dihalobenzenoid, and alkali are added to the xanthone compound or thioxanthone compound represented by the formula, and the mixture is heated to 200 to 400°C to react. In this case, it is desirable that the dihydric phenol and the dihalobenzenoid be used in substantially equal molar amounts, and that the excess amount of one of them should not exceed 5 mol%. The amount of alkali to be used in this case is selected such that the amount of alkali metal atoms is 0.3 to 2 gram atoms per mole of hydroxy group. In this method, in addition to the dihydric phenol and dihalobenzenoid as raw materials, if desired, a halophenol of the general formula (), 4,4 ′−
Dichlorodiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, etc. can also be used in combination. In this case, it is desirable to select a ratio such that the molar ratio of all hydroxyl groups to halogen atoms in the reaction system is within the range of 1:0.95 to 1:1.05. On the other hand, when the dihydric phenol of the general formula () is used in the form of an alkali salt, it is not necessary to particularly add an alkali to the reaction system. In this case, when halophenol of general formula () and 4,4'-dihydroxydiphenyl sulfone are used together, it is necessary to use these in the form of an alkali salt. Next, in an embodiment of the present invention using a halophenol of the general formula (), a predetermined halophenol and an alkali are added to the xanthone compound or thioxanthone compound of the general formula () and heated, or an alkali of the halophenol is Add salt and heat. At this time, if halophenol is used, a small amount of divalent phenol or a dihalobenzenoid compound is added, and if an alkali metal salt of halophenol is used, a small amount of an alkali metal salt of divalent phenol or a dihalobenzenoid compound is added as desired. Benzenoid compounds can also be added as molecular weight regulators. however,
In either case, the molar ratio of hydroxyl group to halogen atom in the reaction system is 1:0.95 to 1:
It is desirable to add it in a range of 1.05. In any embodiment of the method of the present invention, the desired polymer can be obtained by heating at a temperature of 200 to 400°C for 5 minutes to 25 hours. If the reaction temperature is lower than 200°C, the produced polymer will precipitate with a low degree of polymerization, making it impossible to obtain the desired high molecular weight crystalline polymer, and if the reaction temperature is higher than 400°C, The use of temperature enhances desirable side reactions such as gelation. In the method of the present invention, the amount of the xanthone compound or thioxanthone compound of general formula () used is not particularly limited, and is within the range of the amount of polymerization solvent normally used in the production of conventional crystalline aromatic polyether ketones. You can arbitrarily choose from. Usually, this range is from 1:0.8 to 1:5 by weight based on the total amount of raw materials. In the conventional production of aromatic polyetherketones, if a solvent with a keto group or a thioether group such as benzophenone or dibenzothiophene is used, a high molecular weight product cannot be obtained, and aromatic polyetherketones cannot be obtained. Although high molecular weight products were only obtained when highly polar solvents such as sulfonic solvents were used (for example,
22938, see Example 2), in the present invention,
It was completely unexpected that a highly crystalline aromatic polyetherketone with a very high molecular weight could be obtained using a xanthone compound or a thioxanthone compound having only keto, ether, or thioether groups as a solvent. This seems to be largely due to the fact that the structure of the solvent is similar to the structure of the produced polymer, and therefore has excellent solubility for the polymer. for example

[Formula] η _sp /c=0.8, melting point 367℃) and (η _sp /c = 0.8 at 25°C in concentrated sulfuric acid, melting point 340
The temperature at which the polymer (°C) dissolves uniformly to form a 2% by weight solution is 292°C and 273°C, respectively, when diphenyl sulfone is used as the solvent, but it is 243°C and 242°C, respectively, when xanthone is used. It is. Also, during polymerization, for example, in a system in which 4-fluoro-4'-hydroxybenzophenone is used as a monomer and potassium carbonate is used as an alkali, and the polymer concentration is about 40% by weight, 300%
When reacting at ℃ for 3 hours, when xanthone was used as a solvent, the produced polymer was completely dissolved and the reaction solution was viscous and stringy, but when diphenyl sulfone was used as a solvent, The resulting polymer was not completely dissolved, and the reaction solution had poor spinnability. Effects of the Invention In the method for producing crystalline aromatic olietherketone of the present invention, unlike conventional methods, a xanthone compound or a thioxanthone compound having excellent solubility in the produced polymer is used as a polymerization solvent. High molecular weight and highly crystalline polymers can be obtained extremely easily, and the resulting polymers dissolve well in the solvent, allowing smooth stirring of the system and preventing the formation of gels due to localized overheating. Moreover, compared to conventional methods, it is possible to obtain a polymer having a degree of polymerization at a lower reaction temperature or a shorter reaction time. Furthermore, since the solvent used in the present invention has no oxidizing properties as is clear from its structure, there is no risk of oxidizing the monomer phenols, and it is thermally stable itself and can be used repeatedly. In addition, it has the advantage of being less likely to produce heterogeneous structures such as branches in the resulting polymer. The high molecular weight, highly crystalline aromatic polyether ketone obtained by the method of the present invention has excellent heat resistance, chemical resistance, mechanical strength, etc., and can be used alone as a structural material, film, fiber, fibril, coating material, etc. It can also be used as a blend with other polymers, or as a composite material mixed with reinforcing materials or fillers such as glass fiber, carbon fiber, aramid fiber, calcium carbonate, calcium silicate, etc. Examples Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. Example 1 4.
4'-difluorobenzophenone 10.91g (0.05 mol), 4,4'-dihydroxybenzophenone 10.71
g (0.05 mol), potassium carbonate 7.19 g (0.052 mol)
and 40 g of xanthone were added, and the atmosphere was replaced with nitrogen. This was heated under a nitrogen seal, passing nitrogen occasionally.
After raising the temperature from room temperature to 300℃ over a period of time,
The reaction was carried out at 300°C for 3 hours. Then, 4 g of dichlorodiphenyl sulfone was added to stabilize the terminal.
After cooling the obtained reaction product and pulverizing it in water,
It was washed twice with hot acetone, twice with warm water, and once with hot acetone to obtain 19.2 g of white polymer powder. Yield 98% This polymer was completely dissolved in concentrated sulfuric acid, and the reduced viscosity (ηsp/
C) was 1.3 dl/g, and the melting point determined from DSC (heating rate (10°C/min) was 367°C. Example 2 In Example 1, 4,4'-difluorobenzophenone (0.05 mol) and 21.62 g (0.1 mol) of 4-fluoro-4'-hydroxybezophenone instead of 4,4'-dihydroxybenzophenone (0.05 mol).
19.5 g of white polymer powder was obtained in exactly the same manner as in Example 1 except that . Yield: 99% This polymer completely dissolves in concentrated sulfuric acid;
The ηsp/C at 25°C was 1.8 dl/g, and the melting point determined by DSC was 367°C. Example 3 Instead of 0.05 mol of 4,4'-dihydroxybenzophenone in Example 1, 5.506 mol of hydroquinone
14.1 g of a white polymer powder was obtained in exactly the same manner as in Example 1, except that 0.05 g (0.05 mol) was used. yield
98% This polymer has a ηsp/
C was 1.0 dl/g, and the melting point determined by DSC was 340°C. Also, no gel formation was observed in this polymer. Example 4 19.4 g of white polymer powder was obtained in exactly the same manner as in Example 2, except that thioxanthone was used instead of xanthone as the solvent.
Yield: 99% This polymer has ηsp/C at 25°C in concentrated sulfuric acid.
The amount was 1.2 dl/g, and the melting point determined by DSC was 366°C. Also, no gel formation was observed in this polymer. Example 5 In Example 1, 16.12 g (0.05 mol) of bis(4-fluorobenzoyl)benzene was added in place of 0.05 mol of 4,4'-difluorobenzophenone.
A white polymer powder was prepared in exactly the same manner as in Example 1, except that 5.506 g (0.05 mol) of hydroquinone was used instead of 0.05 mol of dihydroxybenzophenone.
19.1g was obtained. Yield: 98% This polymer has ηsp/C at 25°C in concentrated sulfuric acid.
was 0.8 dl/g, and the melting point determined by DSC was 366°C. Further, no gel formation was observed in this polymer either. Example 6 4,4'-dihydroxybenzophenone 43.016g
(0.201 mol), 4N potassium hydroxide solution (f
= 1.0041) 100 ml and 100 ml of distilled water were placed in a 500 ml eggplant flask and stirred under nitrogen until uniformly dissolved. Next, water was distilled off using a rotary evaporator, and the yellow viscous liquid obtained was vacuum dried on a 160°C oil bath for 8 hours to obtain a yellow solid. It was ground in a vacuum to obtain 55 g of yellow powder. When a part of this powder was dissolved in distilled water and titrated with 0.1N hydrochloric acid using methylredo as an indicator, water was completely removed and it was found to be pure dipotassium salt of 4,4'-dihydroxybenzophenone. I found out. Next, 14.52 g of the dipotassium salt of 4,4'-dihydroxybenzophenone obtained in this way
(0.05 mol), 4,4'-difluorobenzophenone
100ml of 10.91g (0.05mol) and 40g of xanthone
When the mixture was placed in a separable flask and the same experiment as in Example 1 was conducted, 19.4 g of white powder was obtained.
Yield 99% This product has ηsp/C at 25℃ in concentrated sulfuric acid.
It was 1.8 dl/g. No gel formation was observed in this polymer either. Example 7 14.52 g (0.05 mol) of the dipotassium salt of 4,4'-dihydroxybenzophenone synthesized in Example 6,
4,4'-dichlorobenzophenone 7.53 g (0.03 mol), 4,4'-dichlorodiphenyl sulfone 5.74
(0.02 mol) and 40 g of xanthone were placed in a 100 ml separable flask and the same experiment as in Example 1 was conducted, yielding 19.8 g of a very pale yellow polymer. Yield: 97% This polymer dissolves uniformly in concentrated sulfuric acid;
ηsp/C at 25°C was 1.4. Example 8 4-Fluoro-4'-hydroxybenzophenone
86.92g (0.402mol) 100ml of 4N potassium hydroxide solution (f=1.0041) and 100ml of distilled water
ml eggplant flask and stirred under nitrogen to react. Then, after distilling off the water using a rotary evaporator, the obtained yellow and colored viscous liquid was vacuum dried at 40°C for 3 hours to obtain a yellow solid, which was crushed in a nitrogen box to give 109 g of yellow solid. A powder was obtained.
A portion of this powder was dissolved in distilled water and titrated in the same manner as in Example 6, and it was found that it contained approximately 10.5% by weight of water. Next, the 4-fluoro-
Potassium salt of 4′-hydroxybezophenone 28.101
(0.1 mol) and 40 g of xanthone were placed in a 100 ml separable flask and the same experiment as in Example 1 was conducted, yielding 19.4 g of white powder. Yield 99
% This material is uniformly dissolved in concentrated sulfuric acid, and the concentration of 25% in concentrated sulfuric acid is
ηsp/C at ℃ was 1.36 dl/g. Comparative Example 1 18.6 g of white polymer powder was obtained in exactly the same manner as in Example 1, except that diphenyl sulfone was used instead of xanthone as the solvent. Yield: 95% This polymer has ηsp/C at 25°C in concentrated sulfuric acid.
was as low as 0.45 dl/g. Comparative Example 2 After carrying out the same reaction as in Comparative Example 1, the temperature was lowered.
The temperature was raised to 330°C, and the reaction was further carried out for 5 hours to obtain 19.4 g of a light gray polymer. Yield: 99% This polymer was partially pale and discolored at the portion in contact with the reactor wall, and was not uniformly dissolved in concentrated sulfuric acid, and gel formation was observed.

Claims (1)

[Scope of Claims] 1. In producing a crystalline aromatic polyether ketone by condensation polymerization of at least one aromatic dihydroxy compound component and at least one dihalogeno aromatic ketone component in a solvent,
As a solvent, the general formula (R and R' in the formula are each a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group,
These may be the same or different, and Y is an oxygen atom or a sulfur atom. 2. In producing a crystalline aromatic polyether ketone by condensation polymerization of at least one monohydroxy monohalogeno aromatic ketone component in a solvent, as a solvent, the general formula (R and R' in the formula are each a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group,
These may be the same or different, and Y is an oxygen atom or a sulfur atom.