JPS638418A - Production of heat-resistant polymer derived from aromatic diamine - Google Patents

Abstract

PURPOSE:To produce the titled polymer at a low production cost without necessitating particular environmental countermeasure for dust treatment, by reacting wet cake of a specific aromatic diamine with a bifunctional aromatic acidic compound. CONSTITUTION:An aromatic dinitro compound or an aromatic mononitroamino compound is dissolved in a polar solvent inert to inhibit polymerization reaction (e.g. N,N-dimethylacetamide), subjected to catalyst reduction in the presence of a heterogeneous hydrogenation catalyst (e.g. platinum) preferably at 20-200 deg.C, filtered and cooled to precipitate crystal of an aromatic diamine and obtain a wet cake having a solvent content of 3-70wt%. The wet cake and equimolar amount of a bifunctional aromatic acidic compound (e.g. aromatic dicarboxylic acid) are mixed to a polar solvent and made to react with each other e.g. at <=100 deg.C to obtain the objective polymer.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement in a method for producing a heat-resistant polymer containing an aromatic diamine as a raw material component, and in particular to improving the safety of the production process. It is an object.

<Prior Art> Aromatic diamines have been widely put into practical use as essential components for the production of heat-resistant polymers. Recently, the need for high-performance polymer materials has been rapidly increasing in the field of advanced industrial technology.
The wings are played by various heat-resistant polymer groups. In this sense, aromatic diamines are becoming increasingly important in industry.

Heat-resistant polymers are generally prepared by combining aromatic diamines and bifunctional aromatic acidic compounds such as pyromellitic dianhydride, trimellitic anhydride monochloride, etc. in an amide polar solvent under anhydrous conditions at room temperature. It is synthesized by reacting terephthalic acid dichloride, isophthalic acid dichloride, etc.

Traditionally, aromatic diamino compounds have been produced by subjecting aromatic dinitro compounds to catalytic hydrogen reduction in a polar solvent, followed by heating/hot filtration, concentration as necessary, crystallization, and isolation.
Drying methods have been widely used. Totaka, British Patent No. 1, 228.738, JP 56-22.752
No. 57-176.935, etc.

Industrially, aromatic diamines are supplied in the form of dry powder or flakes.

<Problems to be Solved by the Invention> However, since aromatic rare aminos are generally mutagen-positive (cancer-causing substances), special environmental measures are required when handling them.

However, since it is handled in the form of powder or flakes, it inevitably generates fine dust, and there are limits to environmental measures. A quick way for users of aromatic amines to solve this problem was to have aromatic diamine manufacturers dissolve aromatic diamines in polymerization solvents and obtain aromatic diamines as a solution. . However, as long as aromatic diamine manufacturers handle aromatic diamines by isolating and drying them, this method does not provide a fundamental solution as it shifts the dust handling work from the user side to the manufacturer side. It is clear that this should not be the case.

One method to solve this problem is to catalytically reduce the aromatic dinitro compound in a polymerization solvent and then remove the by-product water in the solution state, and use the resulting aromatic diamine solution as it is in the polymerization process. A method has been proposed (for example, Japanese Patent Laid-Open No. 60-210630). This method is effective in terms of environmental protection because it eliminates the need to handle aromatic diamine powder. However, in the case of this method, since the purification step of the aromatic amine is cut, there is a problem that low-boiling and high-boiling impurities remain and the quality is degraded.

Also, if the diamine manufacturing factory and polymerization factory are far apart,
There is also the problem of high storage and transportation costs.

As described above, it has been difficult to achieve both environmental protection and cost/performance for aromatic diamines with the methods proposed so far, so the production of heat-resistant polymers derived from aromatic diamines can be surprisingly expensive. There were many.

Therefore, the present inventors have conducted intensive studies aimed at achieving both environmental protection and cost/performance ε of aromatic diamines, and as a result, reducing the manufacturing cost of heat-resistant polymers, and as a result, they have arrived at the present invention.

Means for Solving the Problems〉 That is, the present invention provides medium-t$;
- After catalytic reduction of an aromatic renitro compound or an aromatic mononitroamino compound in the presence of a heterogeneous hydrogenation catalyst in a polar solvent, the heterogeneous hydrogenation catalyst is recovered by mouth, and then the plate is prepared. Aromatic diamino is crystallized and the solvent content is 3 to 70M.
Heat resistance derived from aromatic reamin, which is characterized by reacting an aromatic reamin wet cake prepared by isolating % of aromatic reamin into a wet cake and a bifunctional aromatic acidic compound in an amide polar solvent. The present invention provides a method for producing a synthetic polymer.

The amide polar solvent used in the present invention is a polar solvent that does not inhibit the polymerization reaction between the aromatic diamine compound and the bifunctional aromatic acidic substance and has an amide bond in the molecule, such as , N@N-dimethylacetamide, N·N-diethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, N-cyclohequinylpyrrolidone, N-methylpiperidone, 1,3-dimethyl-2- Examples include imidazolidinone and hexamethylphosphoramide. Particularly useful are N-methylpyrrolidone and N,N-dimethylacetamide. Further, N,N-dimethylformamide, which is a similar compound, has a polymerization inhibiting effect in polymerization systems that utilize acid chlorides, and cannot be used for the purpose of the present invention.

The aromatic dinitro compound or aromatic mononitroamino compound used in the present invention has the general formula O□N-Ar-No□
It is also an interesting compound and represents a divalent aromatic residue selected from the general formula -Ar-1. Here, R, is an alkyl group or alkoxy group having 1 to 4 carbon atoms, and X is a direct bond -〇-1-S-1O
CH3CF3 -C-1-SO, -1-C-1-〇- or CH3CF
3 O ll -N-C-1a represents O or an integer of 1 to 4, and b represents O or an integer of 1 to 12. Specific examples of -Ar- are as follows.

That is, ÷0(ΣS÷0÷, HOOH) The heterogeneous hydrogenation catalyst used in the present invention is a metal or metal oxide catalyst that is generally used in catalytic reduction.
For example, platinum, palladium, rhodium, ruthenium,
Nickel, cobalt, copper, platinum oxide, palladium oxide,
Examples include rhodium oxide. These metal catalysts are
Although it can be used in the form of a metal, it is usually used by being attached to the surface of a carrier such as Vacphone, barium sulfate, Norica gel, or alumina, and nickel, cobalt, copper, or the like is also used as a Raney catalyst. The amount of catalyst used is 0.00 parts as metal content per 100 parts of the raw material nitro compound.
01 to IO parts, and preferably 0.1 to 5 parts when attached to a carrier.

The reaction temperature is not particularly limited, but is generally 20 to 200°C.
A range of , particularly a range of 50 to 130°C is preferred.

Furthermore, the pressure of hydrogen used in the reaction is usually 0.00 gauge pressure.
The optimum range varies depending on the activity of the catalyst. For example, in the case of 5% palladium/activated carbon or 5% platinum/activated carbon, a gauge pressure of 0.1 to 5 kq/d is appropriate, but in the case of Raney nickel, it is 10 to 50 kq.
/d is appropriate.

In the hydrogenation reaction of the present invention, -No2+ 3H2-e
The reaction of -NH, +2H20 produces 2 moles of water from 1 mole of NO2 groups.

A step of crystallizing diamino and a step of separating aromatic diamine by filtration and recovering a wet cake of aromatic diamine crystals are sequentially performed. However, if excessive concentration is performed in step B, step C will be unnecessary.

If necessary, a step of distilling and removing by-product water in the hydrogenation reaction may be added before, during, or after any of these steps.

This by-product water is removed by distillation by heating the hydrogenation reaction mother liquor or the crystallization mother liquor under normal pressure or reduced pressure to distill off water as a low-boiling component. In this case, water may be distilled off azeotropically with the solvent by simple distillation, or may be rectified through a rectification column. In the former case,
It can also be used as the concentration operation in B above.

It is also effective to use effective azeotropic aids such as aromatic hydrocarbons and aromatic halogenated hydrocarbons such as benzene, toluene, xylene, and chlorobenzene. In the hydrogenation reaction mother liquor, when an aromatic dinitro compound is used as a raw material, 4 moles of water are produced as a by-product per 1 mole of aromatic diamine. The above-mentioned by-product water distillation removal operation is carried out with the aim of reducing the water content in the final wet cake to 0.5 mol (preferably 0.1 mol) or less per 1 mol of aromatic diamine. Ru.

It is not preferable for the water content in the wet cake to exceed 0.5 mole per mole of aromatic diamine, as this will significantly reduce the polymerization activity when the aromatic diamine wet cake is directly reacted with a difunctional aromatic acidic component. .

In the present invention, the step of recovering an insoluble catalyst and the step of separating the crystallized aromatic diamine by mouth to recover a wet cake of aromatic diamine crystals can be carried out using any conventional solid/liquid separator. . Typical examples include static pressurizing filters, static vacuum filters, pressure filter presses, centrifugal separators, rotating drum filters,
Examples include rotary belt filters. This separation operation results in a liquid content of 70 (
Preferably, the amount is 60% by weight or less.

If the liquid content exceeds 70% by weight, it is not preferable because there is a risk that the solution phase will separate during storage when the temperature is high, such as in summer.

The liquid content of the wet cake obtained in the present invention can be further reduced by intensifying the concentration operation or by subjecting it to a drying process after separation and recovery. The effect of preventing the aromatic diamine dry powder from scattering, which is one of the objects of the present invention, can be obtained when the liquid content is 3 (preferably 10)% by weight or more, and the wet cake of the present invention has a liquid content of 3 to 70% by weight. (preferably 10 to 60% by weight) of aromatic diamine crystal aggregates.

The difunctional aromatic acidic compound used in the present invention has the general formula: Here, Y is a hydroxyl group, a halogen group, or a carbon number of 1 to
The 12 alkoxy groups, Ar, Ar', and Ar- represent an aromatic group having 6 to 40 carbon atoms.

Examples include.

It will be done.

It will be done.

The heat-resistant polymer in the present invention is a mixture of the above-mentioned aromatic diamine wet cake and a bifunctional aromatic acidic compound in a substantially equimolar ratio (1/1±0.05 molar ratio) in an amide polar solvent. However, it is synthesized by reacting for about 0.1 to 10 hours at a temperature of 100°C (preferably 80°C) or lower. The heat-resistant polymer synthesized under these conditions becomes aromatic polyamide, aromatic polyamide/amic acid, or aromatic polyamic acid by coating with a difunctional aromatic acidic compound. Aromatic polyamide/amic acid and aromatic polyamic acid are subsequently converted into aromatic polyamide-imide and aromatic polyimide by causing a chemical ring-closing or thermal ring-closing reaction.

<Example> Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 4-4'-dinitrodiphenyl ether 182f (0.7 mol), 5% platinum carbon powder 4y manufactured by Engelhard Japan, and N were placed in a glass autoclave with an internal volume of 5 g.
-Methyl-2-pyrrolidone (hereinafter abbreviated as NMP)
After charging 1,000 liters of chicken and replacing the air in the autoclave with nitrogen, it was pressurized to 3 kg/d gauge with hydrogen via an intermediate tank of 201,120 da/d gauge.

Next, the mixture was heated to 90° C. over 30 minutes with gentle stirring, and then the reaction was started with vigorous stirring. after that,
Hydrogen pressure of 3 kf/d gauge was continuously applied inside the autoclave. After about 120 minutes after the start of strong stirring, the gauge pressure in the intermediate tank stopped decreasing, so stirring was continued for 1 hour to complete the reaction. Next, the contents were passed through a suction port to remove platinum-carbon powder and other insoluble matter, and the obtained filtration mother liquor was transferred to a 5 g flask equipped with a rectifying tube, a nitrogen gas introduction tube, and a stirrer. 500 d of toluene while flowing gas
was added and heated to about 120 to 130°C, and the water in the system was azeotropically distilled together with toluene. followed by 500 toluene
ml was added, and finally substantially all of the toluene was distilled off to complete the dehydration operation.

The water content of the obtained dehydrated solution was measured by the Karl Fuscher method and was found to be 380-.
When analyzed by liquid chromatography, the purity of the aromatic compounds was 98.996, and the yield was 99.8%.

Next, the dehydrated solution of 4,4'-DDE obtained above was charged into a glass rotary evaporator with an internal volume of 51 cm, and concentrated under a reduced pressure of 40 fiHg to obtain NMP.
After about 80 Q ml of distilled water was cooled to room temperature, a crystallized slurry of 4@4'-DDE was obtained. Next, this crystallization slurry was centrifuged to collect crystals, and about 1,531 wet cakes containing 37% by weight of NMP were obtained. 4.4' in this wet cake
-DDE was analyzed by liquid chromatography and found to have an excellent purity of 99.6% among aromatic compounds.

Next, the wet cake 3L8f of 4,4'-DDE obtained above was placed in a round bottom flask with an internal volume of IN equipped with a stirrer.
(0.10 mol in terms of DDE), metaphenylenediamine 4.32y (0.04 mol) and N M P 300
ml was charged and uniformly dissolved. While cooling this solution in an ice-water bath, 29.5y (Q, 14 mol) of trimellitic anhydride monochloride in the form of a solid powder was added under stirring at a rate such that the internal temperature did not exceed 30°C, and then Stirring was continued for 1 hour to obtain a polymer stock solution. Next, this polymer stock solution was poured into water 10e under strong stirring to precipitate the polymer,
A polyamide-imide polymer powder was obtained by washing with water/dehydration/drying. Logarithmic viscosity pinh (concentration: 0
．． The measured value was 0.88, which was highly practical.

Comparative Example 1 The same operations as in Example I were carried out except that N@N-dimethylformamide was used instead of NMP as the hydrogenation reaction solvent and polymerization solvent, and the resulting polymer had a 'Pinh of 0.25. This was extremely low.

Example 2 4,4'-dinitrodiphenyl ether 1821c0.
The same procedure as in Example 1 was carried out except that 4-nitro-3'-aminodiphenyl ether 161F (0.7 mol) was used instead of 4-nitro-3'-aminodiphenyl ether 161F (0.7 mol). A combination was obtained.

Example 3 A 2° 2-screw (
4-p-Nitrophenoxyphenyl A4) Propane 329,71 (0.7 mol), 5% palladium-carbon powder 14F and N,N-
Dimethylacetamide (hereinafter abbreviated as DMAC)
After charging 500 g of autoclave and replacing the air in the autoclave with nitrogen, it was pressurized with hydrogen to 2 kq/c4 gauge via an intermediate tank of 206.20 kv/d gauge. Next, the mixture was heated to 80° C. with gentle stirring, and then the reaction was started with vigorous stirring. Thereafter, hydrogen pressure of 2 kq/d gauge was continued to be applied to one autoclave. About 5 hours after the start of strong stirring, the cage pressure in the intermediate tank almost stopped decreasing, so stirring was continued for 2 hours to complete the reaction. Next, the contents are passed through the suction port and palladium-
Carbon powder and other insoluble matter were removed, and the resulting filtration mother liquor was charged into a glass σ-tally evaporator with an internal volume of 51 cm, and concentrated under reduced pressure of 4 Q mHg.

In this concentration operation, water is distilled out at the beginning, and water/D
The MAC azeotrope was distilled out, and at the end, DMAC was distilled out, and the total distilled amount was about 1.450 zt. As a result, 3901 pieces of wet cake containing 28% by weight of DMAC remained in the evaporator. When 2,2-bis(4-p-aminophenoxyphenyl)propano (hereinafter abbreviated as PODA) in this wet cake was analyzed by liquid chromatography, the purity of the aromatic compounds was 99.1%.
Met.

Next, 57.1f of the wet cake of PODA obtained above (PODA
0.10 mol (calculated as A) and 400 ml of DM AC were charged and uniformly dissolved. Place the flask containing this solution in an ice water bath and add 20.3F (0.1 mol) of a solid powdered mixture of terephthalic acid chloride/isophthalic acid dichloride (1F 1 molar ratio) while stirring until the internal temperature exceeds 30°C. The polymer stock solution was obtained by adding the polymer at the same rate and then continuing stirring for 1 hour. Next, this polymer stock solution was poured into 1O1 water under strong stirring to precipitate the polymer, and the polymer was washed with water, dehydrated, and dried by heating to obtain a polyamide polymer powder. 'Pinh of the obtained polymer 1. It is highly practical with a t of 0.70.

Example 4 Bis(
All operations were performed in the same manner as in Example 3 except that 4-p-nitrophenoquinphenyl)sulfono 345.1y (0.7 mol) was used. 3'-dinitrobenozamide 143.5y (0.5 mol), Raney nickel aqueous paste 3.5y and 1,3-dimethyl-2-imidazolidino 7 (hereinafter abbreviated as DMI) 1500zl were charged and placed in an autoclave. After replacing the air with nitrogen, the tank was pressurized with hydrogen to 8 to 9/C4 gauge via a 201,20#/d gauge intermediate tank. Next, the mixture was heated to 80° C. with gentle stirring, and then the reaction was started with vigorous stirring. Thereafter, the temperature was raised to 90°C, and a hydrogen pressure of 3 kg/d gauge was continued to be applied inside the autoclave. Approximately 10 hours after the start of strong stirring, the gauge pressure in the intermediate tank almost stopped decreasing, so stirring was continued for 2 hours to complete the reaction.

Next, the contents were passed through a suction port to remove Raney nickel and other insoluble matter, and the resulting filtration mother liquor was transferred to a 5e flask equipped with a rectification tube and a stirrer, 500 ml of xyleno was added, and the water was The system was heated under reduced pressure using a subilator to azeotropically distill off the water in the system together with xyleno. Subsequently, xylene 5 Q Q tt was further added, and finally substantially all of the xylene was distilled off to complete the dehydration operation.

Next, the dehydrated solution was charged into a glass rotary evaporator with an internal volume of 51 cm, and concentrated under a pressure of 40 flHg to distill out about 1250 xl of DMI. When cooled to room temperature, 4e3'-diaminobenzanilide was obtained. (hereinafter abbreviated as 4.3/-DABA) was obtained. Next, the crystallization slurry was centrifuged to collect crystals, and a wet cake containing 46% by weight of DMI was obtained at about 204F. When 4,3'-DABA in this wet cake was analyzed by liquid chromatography, the purity of the aromatic compounds was 98.8%.

Next, in a round bottom flask with an internal volume of 14 equipped with a stirrer, add the 3,4'-DABA obtained above to l) Wet cake 42
g (0.1 0 mol in terms of 3-4'-DABA) and DMI3oomz were charged and uniformly dissolved. The flask containing this solution was placed in an ice water bath, and while stirring, 32.2 F (0.1 mol) of solid powder 3,3',4,4'-benozophenonetetracarboxylic dianhydride was added until the internal temperature was reached. 3
The mixture was added at a rate that did not exceed 0° C., and stirring was continued for 1 hour to obtain a polymer stock solution. Next, this polymer stock solution was poured into water 101 under strong stirring to precipitate the polymer, which was then washed with water, dehydrated, and dried by heating to obtain a polyimide polymer powder.

The 7 inch of the obtained polymer was 0.69, which was highly practical.

<Effects of the Invention> The wet cake of aromatic diamino obtained during the process of the present invention does not require measures against harmful substance dust and has excellent cost/performance. By reacting with pyromellitic dianhydride, trimellitic anhydride monochloride, terephthalic acid dichloride, isophthalic acid dichloride, etc., heat-resistant polymers having a practically high degree of polymerization can be safely produced. Utilizing their excellent heat resistance and mechanical properties, these heat-resistant polymers are widely used in fields such as electrical and electronic parts, aerospace equipment parts, automobile parts, and office equipment parts.

Claims (1)

[Claims] After catalytically reducing an aromatic dinitro compound or an aromatic mononitroamino compound in the presence of a heterogeneous hydrogenation catalyst in a polar solvent that does not inhibit the polymerization reaction, the heterogeneous hydrogenation catalyst is Aromatic diamine wet cake and difunctional aromatic acidic compound prepared by collecting the aromatic diamine by filtration and then crystallizing the aromatic diamine and isolating it in the form of a wet cake with a solvent content of 3 to 70% by weight. 1. A method for producing a heat-resistant polymer derived from an aromatic diamine, which comprises reacting the following in an amide polar solvent.