JPS6220530A - Production of aromatic polyketone - Google Patents

Abstract

PURPOSE:To obtain a high-quality polyketone at low temperatures in a short time, by using, as a polymerization solvent, specific (thio)xanthone compound to homogeneously dissolve the polymer formed in said solvent to prevent gelation due to local heating. CONSTITUTION:Using, as a solvent, a xanthone or thioxanthone compound of formula I (R and R' are each H, 1-3C alkyl or phenyl; Y is O or S), (A) 4-hydroxythiophenol and (B) 4,4'-dihaloterephthalophenone or 4,4'- dihalobenzophenone are brought to polycondensation to obtain the objective crystalline poly-(etherthioether aromatic ketone) with an intrinsic viscosity >=0.4 having linear polymer structure in which structural unit of formula II or III and that of formula IV are alternately linked with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improved process for producing crystalline aromatic polyketones. More specifically, the present invention uses a specific reaction solvent and has excellent heat resistance, chemical resistance, twist resistance, mechanical strength, etc. The present invention relates to an industrially advantageous method for producing a high molecular weight, highly crystalline poly(ether thioether aromatic ketone).

BACKGROUND OF THE INVENTION In recent years, crystalline aromatic polyetherketones, in which phenylene groups are linked via ether groups and ketone groups, have been found to have excellent heat resistance, chemical resistance, mechanical strength, etc.
It is attracting attention as a molding material in various fields.

Such crystalline aromatic polyetherketones have traditionally been
It has been produced by a polycondensation method using highly polar sulfonic solvents such as diphenylsulfone and sulfolane. For example, a method of heating a dialkali metal salt of bisphenol containing a ketone group and a dihalogeno compound containing a ketone group to a temperature of 250 to 400°C in the presence of an aromatic sulfone (Japanese Patent Publication No. 57-22938); Halophenols with alkali metal carbonates, K, N
- Method of heating in methylpyrrolidone, aliphatic sulfone or aromatic sulfone compound to a temperature of 200 to 400 °C (
It is known that crystalline aromatic polyetherketones can be produced by methods such as U.S. Pat. No. 4,113,699).

In addition, the present inventors focused on the excellent properties of crystalline aromatic polyether ketone, and after conducting extensive research, first discovered
4.4'-dihaloterephthalophenone and 4=hydroxythiophenol together with alkali gold ffi carbonate in an aliphatic sulfone or aromatic sulfone solvent at 200 to
Ifc, 4,4'-dihalobenzophenone and 4-hydroxythiophenol are polycondensed in the same manner as above by heating to a temperature of 400°C to cause polycondensation (Japanese Patent Application No. 1982-264145). (Patent application 1986-2)
No. 64608), a novel crystalline polyester having a chemical structure in which phenylene groups are linked via ether groups, thioether groups, and ketone groups, and has excellent heat resistance, flame retardance, solvent resistance, mechanical properties, etc. (ether thioether aromatic ketone) was found to be obtained.

In this way, sulfonic solvents have been used as reaction solvents in the production of crystalline aromatic polyether ketones and crystalline poly(ether thioether aromatic ketones). Especially high molecular weight crystalline poly(ether thioether aromatic ketones)
In order to produce this, it could not be said that the solvent was necessarily satisfactory in terms of solubility of the pentapolymer and thermal stability at high temperatures.

Generally, in order to produce a high molecular weight polymer, it is necessary to proceed with the reaction in a polymerization medium that dissolves the produced polymer, but in the case of crystalline poly(ether thioether aromatic ketone) Because they are insoluble in the sulfonic solvent at low temperatures, the polymerization must be carried out at a high temperature, preferably 250° C. or higher, and it cannot be said that there are no problems with the thermal stability of the solvent.

Therefore, in order to industrially advantageously produce a high molecular weight crystalline aromatic poly(ether thioether aromatic ketone), it is necessary that the resulting polymer has excellent solubility, is stable even at high temperatures, and has an appropriate polarity. It has been desired to select a compound having the following properties and use it as a polymerization compound.

Problems to be Solved by the Invention Under these circumstances, the purpose of the invention is to ensure that the resulting polymer has excellent solubility, is stable even at high Rk, and has an appropriate polarity of 1. By using a polymerization solvent having a polymerization solvent, it is possible to industrially advantageously produce a high-molecular-weight, high-crystalline poly(ether thioether aromatic ketone) with excellent heat resistance, chemical resistance, flame retardance, mechanical strength, etc. The goal is to provide a way to do so.

Means to Solve the Problems The present inventors have conducted extensive research to achieve the above object, and have found that certain types of polymerization solvents can be used to produce crystalline poly(ether thioether aromatic ketone). It was discovered that the object could be achieved by using a xanthone compound or a thioxanthone compound, and based on this knowledge, the present invention was accomplished.

That is, the present invention involves condensation polymerization of 4-hydroxythiophenol and 4,4'-dihaloterephthalophenone or 4,4'-dihalobenzophenone in a solvent to form a structural unit represented by the formula and a crystalline poly(ether thioether aromatic Ketone), the solvent may be of the general formula (where R and R' are each a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group, which may be the same or The present invention provides a method for producing a crystalline poly(ether thioether aromatic ketone) characterized by using a xanthone compound or a thioxanthone compound represented by .

The condensation polymerization reaction in the method of the present invention uses, for example, substantially equimolar amounts of 4-hydroxythiophenol, 4,4'-dino lotylephthalophenone, or ij4,4'-dino-10benzophenone, and a predetermined solvent. in the presence of an alkali or an alkali metal salt of 4-hydroxythiophenol and substantially equimolar amount of 4,4'-dino lotylephthalophenone or ij4,
This can be carried out by heating 4'-dino lobenzophenone in a predetermined solvent.

Among these methods, the former alkali is used because 4-hydroxythiophenol, which has free hydroxyl groups and mercapto groups, is more stable than its alkali metal salt, and the polymerization procedure is simpler. The method is preferred.

The raw material monomers used in the method of the present invention are as follows.

4-Hydroxythiophenol or its alkali metal salt and 4 represented by the general formula (Xl and x2 in the formula are /.logen atoms, which may be the same or different)
, 4'-dino lotylephthalophenone, or 4,4'-dino lopenzophenone represented by the general formula (Xl and X2 in the formula have the same meanings as above)
- The alkali metal salt of hydroxythiophenol can be obtained by a known method, for example, by reacting 4-hydroxythiophenol with an alkali metal hydroxide.

Specific examples of "i fc, 4."-dihaloterephthalophenone include 4,4'-dichloroterephthalophenone,
4.4'-dichloroterephthalophenone, 4-chloro-
Examples include 4'-fluoroterephthalophenone. These monomers may be used alone or in combination of two or more.

On the other hand, specific examples of 4.4'-dihalobenzophenone include 4.4'-dichlorobeny/siphenon, 4.4'-dichlorobenzophenone,
'-dino 10 benzophenone, 4-chloro-47-fluorobenzopheno 7, and the like. These monomers may be used alone or in combination of two or more.

Thus, in the present invention, it is not necessary to use a fluorine compound that is difficult to obtain as a raw material, and Xl and X
Even if an easily available compound in which both of 2 and 2 are chlorine atoms is used, a high molecular weight polymer can be obtained in the same polymerization time as when a fluorine compound is used.

In the method of the present invention, it is necessary to use a xanthone compound or a thioxanthone compound represented by the general formula (R, R' and Y in the formula have the same meanings as above) as a solvent for monopolymerization. Examples of such compounds include xantho/thioxanthone, 2-phenylxanthone, 2-phenylthioxanthone, 2-methylxanthone, 2-methylthioxanthone, 1,3-dimethylxanthone, and the like. Particularly preferred among these are xanthone and thioxanthone. 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 such as diphenylsulfone, sulfolane, etc. within a range that does not impair the purpose of the present invention.

Examples of the alkalis used in the method of the invention include hydroxides, carbonates, and bicarbonates of alkali metals.

Fluorides, hydrides, alkoxides, alkylated compounds, etc. are used. Among these, preferred are alkali metal carbonates and alkali metal N carbonates, and specific examples thereof include sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and carbonate. Examples include rubidium hydrogen and cesium hydrogen carbonate.

Particularly suitable are sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. These alkalis may be used alone or in combination of two or more.

Next, a preferred embodiment of the production method of the present invention will be described. First, in a solvent such as xanthone or thioxanthone, a required amount of alkali metal carbonate, alkali metal bicarbonate, 4-hydroxythiophenol and dihaloaromatic Add the compound (4,4'-dihaloterephthalophenone or 4,4'-cyhalopenzophene 7)). At this time, the solvent is usually 10 to 1000 parts per 100 parts by weight of the 4-hydroxythiophenol and the dihaloaromatic compound.
Used in parts by weight. Further, the alkali metal salt has an amount of alkali metal atoms of 0.3 to 2 gram atoms, preferably 0.3 to 2 gram atoms per μmol of 4-hydroxythiophenol.
A proportion of 5 to 1.2 gram atoms is used.

If the alkali metal salt is used in excess, the reaction will be too vigorous, causing harmful side reactions and also being disadvantageous in terms of cost, so it is desirable to use as little amount as possible. However, when the amount of alkali metal atoms is less than 0.3 gram atoms, it is necessary to lengthen the polymerization time, and it becomes difficult to obtain a polymer with a desired high molecular weight.

The alkali metal salt is preferably anhydrous, but if it is a hydrated salt, it can be used by distilling off water together with the azeotropic solvent from the polymerization reaction system.

Further, the ratio of 4-hydroxythiophenol and the dihaloaromatic compound used must be substantially equimolar, with the former being 0.95 to 1 mol per mol of the latter.
If the amount is outside this range, it becomes difficult to obtain a high molecular weight polymer. In order to form a stable aromatic halide unit at the polymer terminal, it is particularly preferable to use 1.00 to 1.05 mol of the dihaloaromatic compound per 1 mol of 4-hydroxythiophenol.

Next, the mixture of the solvent, alkali metal salt, and monomer is heated in an inert gas atmosphere F, such as nitrogen or argon, to 200-400°C, preferably 250-350°C.
The polymerization reaction is carried out in the temperature range of . If this temperature is less than 200°C, the polymer will precipitate during polymerization and a high molecular weight polymer will not be obtained, while if it exceeds 400°C, the resulting polymer will deteriorate and become seriously discolored. In addition, a rapid temperature rise is undesirable because it causes side reactions, such as coloring and gelation of the 1/% polymer. Therefore, it is necessary to raise the temperature in one step or gradually (() and to devise measures to keep the temperature of the polymerization system as uniform as possible.

Obtaining a high molecular weight polymer with an intrinsic viscosity of 0.4 or more [Then,
The polymerization temperature should ultimately be 200℃ or higher ((), but prepolymerization is carried out at a temperature lower than that. Moisture generated during the polymerization is removed from the system. However, methods for removing it include simply replacing the gas phase of the polymerization system with dry inert gas, or introducing a solvent with a lower boiling point than the polymerization solvent into the system and distilling it out of the system together with it. Methods such as removing the material are used.

The polymerization reaction is carried out using a suitable terminal capping agent, such as a monofunctional or polyfunctional compound, specifically methyl chloride, tar
The reaction can be stopped by adding t-butyl chloride, 4,4'-dichlorodiphenyl sulfone, etc. to the reaction system at the above-mentioned polymerization temperature. In addition, this makes it possible to obtain a polymer having a thermally stable alkyl group or...rogen group at the end.

The polymer of the present invention thus obtained has the configuration (II
D -゛℃-8- are connected alternately, or
) − constituent unit (n) c and constituent unit (I
[D] are connected alternately.

These structural units are a structural unit corresponding to formula 1 based on the bonding form of the oxygen atom and sulfur atom of the structural unit (DI) to the structural unit (1) or (11), and a structural unit of formula 111 (■ (here and m is 0 or 1), but the polymer compound of the present invention may contain either one of these structural units, or both may be randomly or regularly arranged. It may also include.

Normally, if there is no particular control, there is no regularity in the connection format, and it is thought that the structure will be random.

Furthermore, since mercapto groups are much more reactive than hydroxyl groups, if they are prepolymerized at a low temperature and then polymerized at a high temperature, the linked structural unit represented by the formula (2) will be preferentially produced; After reacting 1 mole of 4-hydroxythiophenol with 0.5 mole of the dino-kachi aromatic compound, the remaining 0.5
When a molar amount of the dino-kuchi aromatic compound is reacted, the structural unit of the connected type represented by (W) above is preferentially produced.

In this way, polymers with various regularities and irregularities can be produced even by combining the same monomers, depending on the polymerization temperature and the method of adding monomers. Of these, the regularity is relatively high;
A material with high crystallinity is desirable.

Polymers produced in this way containing structural units with different connection types in various proportions have different crystal melting points (Tm), glass transition temperatures (Tg), and crystallization speeds, so they may vary depending on the application. It is possible to select an appropriate represition method.

Further, it is necessary that the intrinsic viscosity of the polymer of the present invention is 0.4 or more, preferably 0.4 to 1.8. Polymers with an intrinsic viscosity of less than 0.4 are brittle and unsuitable for use as films or injection molded products.

In the method of the present invention. There is no particular restriction on the amount of the xanthone compound or thioxanthone compound used in the general formula
The amount of the polymerization solvent used can be arbitrarily selected from within the range of amounts commonly used in the production of conventional crystalline aromatic polyether ketones.

Typically, this range is 10% by weight based on the total amount of raw materials.
The range is from 0:10 to 100:1000.

In the conventional production of aromatic polyetherketones, if a solvent with a ketone group or a thioether group such as benzophenone or dibenzothiophene is used, a high molecular weight product cannot be obtained, and aromatic sulfones cannot be obtained. Although high molecular weight products were obtained only when highly polar solvents such as system solvents were used (see, for example, Japanese Patent Publication No. 57-22938, Example 2), in the present invention, ketones A xanthone compound or a thioxanthone compound having only a group, an ether group, or a thioether group is
It was completely unexpected that a very high molecular weight, highly crystalline IJ- (ether thioether aromatic ketone) was obtained as a vehicle.

This is thought to be because the structure of the solvent is similar to the structure of the polymer to be produced, so that the polymer chains produced during one polymerization are well dispersed and the reaction is likely to occur.

For example, the temperature at which a polymer with an intrinsic viscosity of 0.85, in which structural unit (1) and structural unit (IQ) are alternately bonded, is uniformly dissolved in a solvent to form a liquid with a weight coefficient of 2 is when xanthone is used as a solvent. is 240°C, but when diphenylsulfone solvent is used, it will not dissolve unless the temperature is as high as 276°C.

Effects of the Invention In the method for producing crystalline poly(ether thioether aromatic ketone) of the present invention, a hexa/ton compound or a thioxanthone compound having excellent solubility for the resulting polymer is used as a polymerization solvent, which is different from conventional methods. Since a high-molecular-weight, highly crystalline polymer can be obtained very easily, and the produced polymer dissolves well in the fermentation medium, stirring of the system is carried out smoothly. Gel formation due to local overheating is suppressed, and compared to conventional methods,
It has the characteristics that it is possible to obtain a polymer having the same degree of polymerization at a low reaction temperature or in a short time of 3 hours. 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 monomer phenols, and it is still thermally stable itself.
It has the advantage of not only being able to be used repeatedly, but also being less likely to produce a heterogeneous structure such as branching in the resulting polymer.

The high molecular weight, highly crystalline poly(ether thioether aromatic keto/) obtained by the method of the present invention has excellent heat resistance, chemical resistance, flame retardance, mechanical strength, etc., and can be used alone as a structural material. It can be used for films, fibers, fibrils, coating materials, etc. In addition, in 1, it can be used as a blend with other polymers, or as a material such as glass fiber, carbon fiber, aramid fiber,
It is also used as a composite material mixed with reinforcing materials or fillers such as calcium carbonate and silicate.

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.

Note that the polymer of the present invention is only slightly soluble in concentrated sulfuric acid and is insoluble in general organic solvents.

It is difficult to determine the average molecular weight. Therefore, the intrinsic viscosity is used as a measure of molecular weight.

In addition, the polymer properties were measured as follows.

(1) Using concentrated sulfuric acid with an intrinsic viscosity density of 1 and 84 f/crA, prepare a solution containing 0.12 polymer per 100 crII solution and a solution containing 0.52 polymer per 100 crII solution, and calculate their viscosity. Measured at 25°C, formula % formula %)) [However, ηrel is relative viscosity, C is concentration (P/1
007 Rite, 6su, "-) Of'i (7+, .1
−1), meaning that the co value was extrapolated to the point where meC is 0).

(2) Crystal melting point (Tm), glass transition temperature (Tg) DS
Temperature increase rate 10℃/m 1 by C (differential scanning calorimeter)
Measured at n.17. The powder obtained by polymerization was used as it was for the measurement of Tm.

Example 1 After purging the fourth sepa2-pull flask equipped with a stirrer, nitrogen inlet pipe and condenser with nitrogen, it was heated to 4.4'
-dichloroterephthalophenone 14.209 (0,04
0 mol), 4-hydroxythiophenol 5.049
(0,0,10 mol), anhydrous potassium carbonate 5.52F (
0,040 mol) and 40 liters of xanthone were added, heating was started under a nitrogen atmosphere, the temperature was raised to 280°C over 1 hour, and the temperature was raised from 280°C to 310°C over another 1 hour. When held at 320°C for 2Uj,
The reaction solution became a viscous liquid.

The reactions were consistently carried out at normal pressure (atmospheric pressure). At that temperature,
Add 4.02 ml of dichlorodiphenyl sulfone.

After stabilizing the ends, it was cooled and water was added.

The resulting solid was crushed and washed twice with hot acetone and twice with warm water.
16.3 times and then once with acetone to form a white solid.
I got an F. The intrinsic viscosity of the obtained polymer was 0.86, Tm
Chilled at 346°C, Tg 152°C.

The film obtained by pressing this polymer at 400° C. for 5 minutes was strong and resistant to bending.

This polymer has a structure in which the structural unit (1) and the structural unit ([[D] are alternately bonded.

Example 2 A separable four-bottle flask equipped with a stirrer, a violet introduction tube, and a condenser was purged with nitrogen, and then 4.4'-
Dichloroterephthalophenone 13.20 ? (0,04
1 mol), 4-hydroxythiophenol 5.0 = 1
? (0,040 mol) and Xanthono 409 were added, heating was started under a nitrogen atmosphere, the temperature was raised to 150°C, and at this point 5.529 (0,040 mol) of anhydrous potassium carbonate was added to initiate polymerization. . Thereafter, the temperature was further increased, and finally the temperature was raised to 1310° C., and when the reaction was continued at this temperature for 2 hours, the reaction liquid became a viscous liquid.

The reactions were consistently conducted under normal pressure (atmospheric pressure) conditions. The resulting polymer solution was treated in the same manner as in Example 1 to obtain a white solid 16. I got Or.

This polymer is crystalline, Tm 340°C, Tg 153
℃, and the intrinsic viscosity was 1.1.

This polymer was formed into a film using a press at 400°C, and after being held at that temperature for 30 minutes, the intrinsic viscosity of the film was 1.
1, there was no change, and it became clear that this polymer was extremely thermally stable.

Example 3 Polymerization was carried out in the same manner as in Example 1 except that thioxanthone 402 was used instead of xanthone 40,
A polymer having an intrinsic viscosity of 0.80 was obtained. This polymer (d=1
Even when pressed at 00°C for 30 minutes, the intrinsic viscosity did not change and it was thermally stable.

Example 4 A separable four-bottle flask equipped with a stirrer, a nitrogen inlet pipe, and a condenser was purged with nitrogen, and then 4,4'-
Dichlorobenzophenone 17.589 (0,070 mol), 4-hydroxythiophenol 8.82 F (0
,070 mol), anhydrous potassium carbonate 9.669 (0,
070 mol) and xa/ton 402 were added thereto, and heating was started under a nitrogen atmosphere at normal pressure. When the temperature was raised to 200° C. in 2 hours, further raised to 300° C. in 1 hour, and maintained at this temperature for 2 hours, anti-CtL became a viscous liquid. The reactions were consistently conducted under normal pressure (atmospheric pressure) conditions. Next, at this temperature, dichlorodiphenylsulfone 4? was added to stabilize the ends, then cooled and water was added. The obtained solid was pulverized and washed twice with warm acetone, twice with warm water, and once with warm acetone to quantitatively obtain a white solid. This material is crystalline, Tm 276℃, Tg 140
°C, its intrinsic viscosity was 0.95 1, 5 at 400 °C
After pressing for a minute, a strong film resistant to bending was obtained.

This polymer has a structure in which structural units (n) and structural units ([11)] are alternately bonded.

Example 5 Using the same apparatus as in Example 3, 15.48 F (0,071 mol) of 4,4'-dichlorobenzophenone was added.
, 4-hydroxythiophenol 8.829 (0,0
70 mol), anhydrous potassium carbonate 7.73 F (0,0
56 mol) and xanthone 507 were added, and heating was started under a nitrogen atmosphere. The temperature was raised to 300° C. in 2 hours and maintained at this temperature for 2 hours. The reactions were consistently conducted under normal pressure (atmospheric pressure) conditions. The reaction solution was cooled and pulverized, then washed twice with warm acetone, twice with hot water, and once with warm acetone to quantitatively obtain a polymer.

This material is crystalline, Tm 277℃, Tg1
The temperature was 35°C and the intrinsic viscosity was 0.83.

This polymer did not change its intrinsic viscosity even when pressed at 400° C. for 30 minutes and was thermally stable.

Example 6 Using the same apparatus as in Example 1, 6.44 F (0,020 mol) of 4,4'-difluoroterephthalophenone was added.

4-Hydroxythiophenol 5.04 F (0,0
40 mol), anhydrous sodium carbonate 2.12 F (0,
020 mol), xanthone 40F, and toluene 10-.

Heating was started under nitrogen atmosphere. After maintaining the temperature at which toluene refluxed for 1 hour, the produced water was azeotropically removed with toluene. Next, at 150℃ for 1 hour and at 200℃ for 1 hour.
After holding for an hour, it was cooled, and 6.44f (0,020 mol) of 4.4'-difluoroterephthalophenone, 2.12F (0,020 mol) of anhydrous sodium carbonate, and 10-toluene were added. After holding at a temperature of reflux for 1 hour and removing the produced water azeotropically with toluene, 15
It was held at 0°C for 1 hour, at 180°C for 1 hour, and at 300°C for 2 hours. After cooling, the same operation as in Example 1 was performed to obtain a solid with an excellent yield of 94%.

This product has an intrinsic viscosity of 1.1, Tm 324°C, Tg1
The temperature was 52°C and it had crystallinity.

Claims (1)

[Claims] 1. 4-hydroxythiophenol and 4,4'-dihaloterephthalophenone or 4,4'-dihalobenzophenone are condensed and polymerized in a solvent to form the formula ▲mathematical formula, chemical formula , tables, etc.▼ or ▲Mathematical formulas, chemical formulas, tables, etc. are available▼ A linear polymer in which structural units shown by the formula ▲Mathematical formulas, chemical formulas, tables, etc. are available▼ are combined alternately When producing a crystalline poly(ether thioether aromatic ketone) having a structure and an intrinsic viscosity of 0.4 or more, the solvent is the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (Formula R and R' therein are each a hydrogen atom and a carbon number of 1 to
3, which may be the same or different, and Y is an oxygen atom or a sulfur atom). Method for producing crystalline poly(ether thioether aromatic ketone).