JPH0267322A - Equipment for manufacturing polyarylene sulfide - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance and durability and to improve the purity of a polyarylene sulfide by using a specified titanium/palladium alloy as a raw material for the equipment for manufacturing polyarylene sulfide. CONSTITUTION:The title equipment is manufacture by using a titanium/ palladium alloy with a palladium content of 0.05-0.5wt.% as a raw material. A polyarylene sulfide is obtd. by performing dehalogenation and sulfide formation of an alkali metal sulfide and a dihalo arom. compd. in this equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to equipment for producing polyarylene sulfide (hereinafter abbreviated as PAS).

More specifically, the present invention relates to equipment for producing polyarylene sulfide through a dehalogenation/sulfurization reaction between an alkali metal sulfide and a dihaloaromatic compound.

[Prior Art] Recently, PAS has been used in a wide range of fields due to its excellent properties such as heat resistance, and PAS of extremely high purity is required depending on these fields of use.

A typical method for producing PAS is a method based on a reaction between an alkali metal sulfide and an aromatic halide.
There is a method for producing it by reacting a hydrous alkali metal sulfide and a dihaloaromatic compound in an aprotic polar organic solvent using equipment manufactured by 5US31G). At this time, P.A.
Since the alkali metal halide salts produced with S are soluble in solvents such as water, it is possible to remove PAS during processes such as phase separation, extraction, and washing using solvents such as water. .

However, in the conventional PAS production method described above, during the reaction process, the sulfide used as a part of the reaction raw material reacts with the reactor material, producing metal sulfides (iron sulfide, nickel sulfide, etc.). do. This by-product metal sulfide is insoluble in the solvent, so it is hardly removed by subsequent processing steps, and inevitably remains in the produced PAS. PAS containing such metal sulfides is limited in its use in applications that require advanced functionality, such as base materials for magnetic recording materials.

In addition, when heavy metal sulfides are mixed in, not only does the color tone of the product change, but P produced under such an environment
AS has a problem of poor thermal stability.

As a solution to these problems, a method for manufacturing PAS using equipment made of titanium (TI) has been proposed (
(Japanese Unexamined Patent Publication No. 1983-23G27).

However, even when using TI equipment,
Although there is no contamination of components such as iron, chromium, and nickel into the product PAS, which is the same as when using conventional stainless steel equipment, TI acid components are mixed in, and this causes a change in the color tone of the product. becomes.

In addition, with conventional equipment, corrosion occurred in areas where PAS adhered during the PAS treatment process, such as dehydration tanks, purification tanks, and transportation piping, making stable operation over a long period of time impossible. .

[Problems to be solved by the invention] In this background and situation, the present invention solves the problem of dehalogenation/
In a method for producing PAS by a sulfurization reaction, for example, a dehalogenation/sulfurization reaction of a hydrous alkali metal sulfide and a Schiff's aromatic compound in an aprotic polar organic solvent, it has excellent corrosion resistance and durability, and has a heat-affected zone. It is an object of the present invention to provide equipment for manufacturing PAS that does not cause corrosion cracking and therefore does not cause contamination of the PAS product.

[Means for Solving the Problems] The inventors of the present invention, in order to provide a PAS manufacturing equipment with fewer problems as described above, have conducted intensive studies on various materials used as materials for the machine 2'. By using equipment made from a titanium palladium alloy made by adding palladium (Pd) to TI, corrosion resistance is significantly improved in the dehalogenation/sulfurization reaction, and therefore it is possible to manufacture PAS without contamination with impurities. They discovered that this is the case and completed the present invention.

That is, the present invention provides palladium-containing Wh 0 , 05-0.
This invention relates to equipment for producing polyarylene sulfide through a dehalogenation/sulfurization reaction using a 5% by weight titanium palladium alloy as a material.

The present invention will be explained in detail below.

It is essential that the material constituting the present invention contains 0.05 to 0.5% by market weight of Pd. In the present invention, when the Pd content in TI is less than 0.05 weight, the expected improvement in corrosion resistance is not observed, and in order to improve the corrosion resistance, it is necessary to
A large amount of Pd is required. However, the material Pc1e
Even if the amount of Pd is increased more than necessary, a commensurate effect cannot necessarily be obtained, and there are also restrictions from an economic point of view, so the upper limit of the Pd content is preferably about 0.5% by weight.

In addition to the above-mentioned amounts of limiting ingredients, the alloy used for the material of the present invention may contain small amounts of ingredients that are unavoidably mixed in from the main raw materials, auxiliary raw materials, etc., or added for other purposes. Ni, No, Mn, V, St.

There is no problem even if it contains S, P, etc., and even if these elements are added, the corrosion resistance in the target dehalogenation/sulfurization reaction environment will not be reduced, and therefore high purity PAS can be obtained. .

Next, an outline of the PAS manufacturing process using equipment made of the above-mentioned materials will be explained.

The PAS manufacturing method and manufacturing process that are the subject of this description are well known.

That is, as mentioned above, it is usually produced by dehalogenation/sulfurization reaction of a hydrous alkali metal sulfide and a dino-10 aromatic compound in an aprotic polar organic solvent.

The aprotic polar organic solvent used here is N
, N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, hexamethylphosphoramide, N-methyl-ε-caprolactam, N-methyl-2-pyrrolidone, l,3-dimethylimidazolidinone, etc., and mixtures thereof. Among them, N
-Methyl-2-pyrrolidone (hereinafter abbreviated as NMP) has the highest chemical stability and is particularly preferred.

In addition, hydrates of lithium sulfide, sodium sulfide, potassium sulfide, etc. are used as alkali metal sulfides, but
Particularly preferred are various hydrates of sodium sulfide. Examples of dihaloaromatic compounds include p-dichlorobenzene,
m-Dichlorobenzene, 0-dichlorobenzene, p-dibromobenzene, dichlornaphthalene, dibromnaphthalene, dichlordiphenyl sulfone, dichlorobenzophenone, dichlordiphenyl ether, dichlordiphenyl sulfide, dichlordiphenyl, Bromodiphenyl, dichlorodiphenyl sulfoxide, etc. are mentioned, but p-dihalobenzene is preferred, and p-dichlorobenzene is particularly preferred.

Many methods are already known for producing RAS by reacting a hydrous alkali metal sulfide with a dihaloaromatic compound in such an aprotic polar organic solvent.
The present invention has a palladium content of O, 05 to o, 5L1
These methods can be used without any particular limitation, except for using equipment that uses 1w% titanium palladium alloy as water source. These manufacturing methods are generally
It consists of two steps: a dehydration step of a hydrous alkali metal sulfide and a condensation polymerization reaction step.

The dehydration step is to remove an aprotic polar hydrated alkali metal sulfide (e.g. sodium sulfide hydrate) in an organic solvent at 200%
This is a process in which excess water is distilled off by heating to around ℃. This step is intended for systems with relatively high water content, and is usually carried out under normal pressure or slightly reduced pressure.

The condensation polymerization reaction step is a step in which a dihaloaromatic compound is charged into a system whose water content has been reduced in the dehydration step, and the system is heated to about 200 to 300° C. to perform a condensation polymerization reaction. This process is
Although the moisture content is small, since the process is carried out at a high temperature, the residual moisture and the vapor pressure of the solvent result in a high pressure of 5 to 30 atmospheres.

The PAS production equipment used in the present invention refers to reactors, evaporators, dehydration tanks, purification towers, transportation piping, storage tanks, etc. used in the PAS production process.

[Function] The corrosion resistance of the material constituting the present invention under the specific corrosive environment in which the dehalogenation/sulfurization reaction is carried out is specific and cannot be predicted based on the knowledge regarding ordinary corrosion-resistant materials.

That is, as a result of intensive study of many materials in order to find a metal material that meets the purpose of the present invention, the present inventors found that almost all of the materials with <(+4) that the present inventors tested had localized 11 In contrast, the material used in the present invention, even if corroded, has a small amount of corrosion, does not cause local corrosion, and is extremely difficult to use without causing product contamination. It was discovered that it exhibits excellent corrosion resistance.

[Effects of the Invention] As is clear from the above explanation, the present invention does not cause local corrosion even in the environment of dehalogenation/sulfurization reaction, and has high corrosion resistance and durability. It is highly pure, with no contamination from metal components.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited only to these Examples.

Example 1 Alloys having the compositions shown in Table 1 and comparative months were
A sample (30 x 40 x 4111111) for the immersion test was cut out, and this was attached to a reaction vessel for producing polyphenylene sulfide (5U331B autoclave of 21 yen container), and the immersion test was conducted.

The reaction conditions are as follows.

First, add sodium sulfide (Na2S" 2.711
20) 0, G12'mol, NMP 150ffll
and heated to 220°C with stirring under a nitrogen stream.
．． 7 ml of effluent consisting mainly of water was distilled off. Then, after cooling the system to 170°C, 0.0% of p-dichlorobenzene was added.
6 mol was added together with 50 ml of NMP, the system was sealed under a nitrogen stream, the temperature was raised, and the mixture was marketed at 230° C. for 2 hours.

After the completion of the reaction, the system was cooled and the reaction product was taken out.

After repeating the same operation 10 times, a sample was taken out from the system and its surface condition was observed. The results are shown in Table 2.

As is clear from Table 2, the equipment materials (Samples No. 1 to No. 3) having the compositions of the present invention had corrosion below the detection limit and exhibited remarkable corrosion resistance and durability.

However, the comparative materials (Samples No. 4 to No. 06) showed localized corrosion and were found to be unsuitable as equipment materials.

Example 2 A reaction vessel for producing polyphenylene sulfide polymer was manufactured using the alloys of samples No. 1 to No. 3 mentioned in Example 1. In addition, a reaction vessel made of 5US304, which is a comparative material, was also manufactured, and a polyphenylene sulfide polymer production operation was conducted. After one year of operation, this reaction 11″t was disassembled,
The surface conditions of gas-contacted parts, liquid-contacted parts, and welded parts were observed. The results are shown in Table 3.

As is clear from Table 3, only very slight corrosion was observed on the entire surface of the reactor using the alloy according to the present invention.
The corrosion rate was also 0.01 weight m/year or less, which was below the detection limit, indicating excellent corrosion resistance and durability.

Further, there was no problem of coloring the product. On the other hand, 8
In the reactor made from 18304, pitting corrosion was observed in the gas-contacted parts and liquid-contacted parts, and the eluted ions caused colored contamination of the polyphenylene sulfide polymer, making it unsuitable as a reactor material. .

Sample No., C02 1O1 old 0.06 2 0.010.0 (ia o, ot o, oe 4 0.020.04 5 0.081.5 0 0.031.27 Table 1 Main chemical components (weight) %) Mo NI Cr Pd l'10.00 1
3al.

0.13 Bal.

0.25 Bat.

0.01　8al.

0.05 8.2 18.5 1.48 20.8 25.8 Bal.

Bal.

Table 2 Sample No., corrosion rate, surface condition (I1m/year) (0.01 retains initial metallic luster) (0,01〃 (0,01〃 0.08 Local corrosion 0.51 Severe general corrosion

Claims (1)

[Claims] Equipment for producing polyarylene sulfide through dehalogenation/sulfurization reaction using titanium palladium alloy with palladium content of 0.05 to 0.5% by weight as material