JPS62252430A - Production of polyphenylene sulfide - Google Patents

Abstract

PURPOSE:To obtain the titled compound containing no oligomers efficiently, by separating two specified layers in a resin solution obtained by reacting a polyhaloaromatic compound with a sulfiding agent and adding an organic acid or an inorganic acid to the reaction mixture. CONSTITUTION:A polyhaloaromatic compound (A) is reacted with 0.8-1.2mol, per mol of component A, of a sulfiding agent at 200-330 deg.C and a pressure of 1.1-200kg/cm<2> for 10min-72hr in 2.5-20mol, per mol of component A, of an organic polar solvent, and 1-300wt%, based on component A, at least one separating agent (D) selected from an organic acid and an inorganic acid is added to the reaction mixture to obtain a resin solution comprising a thick polymer layer comprising polyphenylene sulfide of an intrinsic viscosity >=0.05 and a thick oligomer layer comprising a phenylene sulfide oligomers, other oligomers and low-MW impurities, etc., and having an intrinsic viscosity <0.05. Either one of said two layers is separated from this solution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyphenylene sulfide.

[Conventional technology and its problems]

Polyphenylene sulfide has excellent properties such as heat resistance, chemical resistance, and flame retardancy, so it is used as parts for electrical equipment, electronics, automobiles, machinery, etc.

Such polyphenylene sulfide can be produced by, for example, removing a resin liquid obtained by reacting p-dichloromethane and sodium sulfide from a reaction vessel in an organic solvent such as N-methylpyrrolidone.
It is produced by removing the solvent and then removing the solvent. (% Kosho 4
5-3368) However, in the conventional manufacturing method of polyphenylene sulfide, the oligomer component that causes foaming during molding, corrosion of the mold, and deterioration of the thermal stability and mechanical properties of the molded product is relatively low. In order to remove these, the polymer after going through the polymerization reaction step, solvent recovery step, and washing step is further treated with a solvent such as acetone, benzene, or tetrahydrofuran, as described in JP-A-57-205425. A process of extracting and removing the oligo9mer component is required, which poses problems such as complication of the process and a large amount of extraction solvent escaping. In addition, in conventional production methods, the system is a homogeneous solution or slurry when the reaction mixture is taken out, so it is not possible to physically separate the polymer and oligomer. The polymerization solvent must be removed from the entire reaction mixture prior to solvent extraction. This is because a large amount of polymerization solvent is used, so the post-treatment process is complicated and takes a long time, and the equipment investment and energy costs are large.
There are problems such as the amount of polymer obtained is small compared to the amount of polymerization solvent treated, and the wastewater treatment process must be carried out strictly to prevent large amounts of polymerization solvent from being mixed into the wastewater for environmental conservation reasons. be.

[Means for solving problems]

The inventors have addressed these drawbacks! ! ! As a result of extensive studies, we found that organic amide polar solvents can be made by adding at least one selected from organic acids and non-acids to a resin liquid (reaction mixture) containing polyphenylene sulfide and ori f-f- obtained by a polymerization reaction. It is possible to separate and separate a liquid layer with a low content and a relatively large amount of polymer from a liquid layer with a high content of an organic amide polar solvent and a relatively large amount of oligomer components. The inventors have discovered that it is possible to efficiently and economically obtain a polymer containing almost no oligomer components while requiring only a small amount of polymerization solvent to be processed, leading to the present invention. After reacting the polyhaloaromatic compound and the sulfidating agent in a solvent, at least one selected from organic acids and inorganic acids is added, and then a thick layer of polymer (I) and a thick layer of oligomer (IQ) is added. The present invention provides a method for producing polyphenylene sulfide, which comprises separating the layer (I) or the layer (I0) from a produced resin liquid.

In the present invention, the term "oligomer" refers to 7-enylene sulfide olico-9mer having an intrinsic viscosity of less than o and os, as well as 9f-mer having a low molecular weight and containing a nitrogen atom in the molecule (this nitrogen atom is a general term that also includes low molecular weight impurities that are produced as by-products during the polymerization reaction (presumed to form primary to quaternary amino groups due to partial decomposition of the polymerization solvent during the polymerization reaction) and low molecular weight impurities that are produced as by-products during the reaction.

The polymer referred to in the present invention is polyphenylene sulfide having an intrinsic viscosity of 0.05 or more.

The polyhaloaromatic compounds used in the method of the present invention include halodanated aromatic compounds having two or more halodane atoms directly bonded to an aromatic nucleus, such as p-dichlorobenzene,
Shiba 047 sen such as m-dichlorobenzene, 0-dichlorobenzene, dibromobenzene is preferred tL<, iJ/lorbenzene, tetrachlorinthene, dichloronaphthalene, trichloronaphthalene, tribromobenzene, dibromnaphthalene, dibrome Benzene, triiodobenzene, dichlordiphenyl sulfone, nobromidiphenyl sulfone, dichlorobenzophenone, nobrobenzophenone, dichlordiphenyl ether, nobromidiphenyl ether, dichlordiphenyl sulfide, dibromidiphenyl sulfide, dichlorbiphenyl, soturompi Phenyl etc. and mixtures thereof can be used in combination. In addition, in order to increase the viscosity of the polymer due to the branched structure, 1
A polyhaloaromatic compound having three or more halodane substituents in the molecule may be used in combination with a low f-zohaloaromatic compound.

The sulfidating agent used in the present invention includes:

Examples include using an alkali metal sulfide compound alone, or using this compound or another sulfur source in combination with an alkali metal hydroxide compound.

Alkali metal sulfide compounds include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures thereof.

Such alkali metal sulfide compounds can be used as hydrates and/or aqueous mixtures or in anhydrous form. However, there is no problem in adding a small amount of alkali metal hydroxide to react with the alkali metal bisulfide and alkali metal thiosulfate present in trace amounts in the alkali metal sulfide.

As the alkali metal sulfide compound, sulfurized mono- to dihydrate salts are preferred.

Other sulfur sources include, for example, alkali metal hydrosulfide compounds, hydrogen sulfide, thioamides, thioureas, thiocarbanates, thiocarginic acids, carbon disulfide, thiocal? These include xylate, sulfur, and phosphorus pentasulfide. Preferred sulfur sources are alkali metal hydrosulfides. In particular, the alkali metal hydrosulfide compounds include lithium bisulfide, sodium bisulfide, potassium bisulfide, rubidium bisulfide, cesiram bisulfide, and mixtures thereof. Such alkali metal hydrosulfide compounds can be used in hydrated and/or aqueous mixtures or in anhydrous form. As such an alkali metal hydrosulfide compound, sodium hydrosulfide is preferable and used in combination with an alkali metal hydroxide compound. You may do so.

Further, examples of the alkali metal hydroxide compound include potassium hydroxide, sodium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures thereof, with sodium hydroxide being preferred, and the sulfur source and hydroxide The appropriate ratio of the alkali metal compound to 1 mole of sulfur element is 0.8 to 3.0 moles of the alkali metal hydroxide compound. In particular, when used in combination with an alkali metal hydroxide compound, the appropriate amount is 0.9 to 1.2 mol per 1.00 mol of the alkali metal hydroxide compound. When an alkali metal carbonate compound is used in combination, it is appropriate that the proportion used is about 1/2 of the alkali metal hydroxide compound.

Further, when N-methyl-4-a is used in combination with sodium nobutyrate, the appropriate amount to be used is in the range of 0.9 to 1.2 mol per 1.0 θ mol of the alkali metal hydrosulfide.

When using each hydrate of the alkali metal sulfide compound or alkali metal hydrosulfide compound, it is necessary to dehydrate it in advance in a solvent before using it in the reaction. Incidentally, when dehydrating the alkali metal hydrosulfide compound, it is preferable to coexist an alkali metal hydroxide compound or sodium N-methyl-4-aminobutyrate.

Organic amide polar solvents used in the method of the present invention include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-
Ethyl-2-pyrrolidone, N-methyl-e-caprolactam, hexamethylphosphoramide, etc. or mixtures thereof are selected. Among these solvents, N-methyl-2-pyrrolidone (NMP) is particularly preferred.

The amount of the sulfidating agent used in the present invention is 0.8 to 1.2 sulfur elements per mole of the dihaloaromatic compound.
mol, preferably 0.9 to 1.1 mol. The amount of the organic polar solvent used is in a molar ratio of 2.5 to 20, preferably 3 to 10, relative to the dihaloaromatic compound.

The reaction temperature at which polymerization is carried out in the present invention is generally from 200°C to
The temperature is 330°C, preferably 210°C to 300°C. The pressure should be in a range such that the polymerization solvent and the haloaromatic compound, which is the polymerization monomer, is maintained substantially in the liquid phase, and generally ranges from 97 cm2 to 200 kl/c at K 1.1'.
rs2, preferably 1.1 kg/crm2 to 20 to 9
A range of 7cns2 is selected. The reaction time varies depending on temperature and pressure, but generally ranges from 10 minutes to about 72 hours, preferably from 1 hour to 48 hours.

4-lifenylene sulfide can be prepared by mixing a polyhaloaromatic compound, a sulfidating agent, and a polymerization aid and heating, preferably under an inert atmosphere. There is no particular restriction on the granulation order for mixing each component, and the above components may be added in portions in small amounts or all at once during the polymerization step.

The organic acid or inorganic acid in the present invention means a proton donor. For example, organic acids include formic acid, acetic acid, gropionic acid, and 2-methyl! Ropionic acid, citric acid, tartaric acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, 2-methyloctanoic acid, dodecanoic acid, 4-ethyltetradecanoic acid,
Octadecanoic acid, cyclohexanecardoic acid, cyclododecanecarboxylic acid, benzoic acid, acrylic acid, adipic acid.

Phthalic acid, succinic acid, citric acid, maleic acid, glutamic acid, aminopropionic acid, polyacrylic acid, etc. o:/
F le? acids, naphthalene-α-sulfonic acid, naphthalene-β-sulfonic acid%” Sulfonic acids such as radluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, benzenesulfinic acid 1.4 Sulfinic acids such as radruenesulfinic acid Examples of inorganic acids include hydrochloric acid, hydrochloric acid,
Hydrogen halides such as iodic acid and hydrofluoric acid, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, carbonic acid, boric acid, silicic acid and phosphoric acid, priphosphoric acid, phosphorous acid, methanophosphonic acid, ethane-1-
Phosphonic acid, chronon-1-7 male heptaonic acid, butane-1-7 male heptaonic acid, butane-2-7 male heptaonic acid, pentane-1-7 male heptaonic acid, cyclohexane-
1-7 male 7, acid.

Vinyl-1-phosphonic acid, Soropen-2-phosphonic acid, Butene-2-phosphonic acid, Indene-2-
Phosphonic acid, phenylmethanephospho7onic acid, (4
-Methyl-phenyl)-methane-phos7onic acid, β-
Naphthyl-methanephos7oic acid, 2-7enyl-ethane-1-7ospho7oic acid, 2,2-diphenyl-ethane-1-phosphonic acid, 4-phenyl-butane-1-
Phosphonic acid, 2-phenyl-ethylene-1-phosphonic acid, 2,2-diphenylethylene-phosphonic acid, phenyl-acetylene-7-osphonic acid, 4-phenyl-butadiene-phosphonic acid, benzene-phos7onic acid, 4- Examples include phosphoric acids such as methyl-benzene-phos-7-oic acid and 2-phenoxy-ethane-1-phos-7-oic acid.

In the present invention, at least one selected from organic acids and inorganic acids is added as a separating agent.

It is preferable that the above-mentioned separation agent is added in an amount within a range that allows it to be dissolved or dispersed in the solvent in the reaction system at the end of the polymerization reaction, and even if it is used in an amount exceeding the dissolution or dispersion limit, separation will not be promoted. The amount of separating agent added varies depending on the type of material used, but
For polyheronated aromatic compounds, which are usually monomers,
It ranges from 1 to 300% by weight, preferably from 5 to 20% by weight.

The above separating agent is preferably added at the end of the polymerization reaction.

If the above-mentioned separating agent is added to the system before the end of the polymerization reaction, it may affect the polymerization reaction. In addition, in order to know the end point of the polymerization reaction, sample a part of the reaction mixture in the system over time and perform the usual treatment, that is, washing with water, filtration, and drying, and then check the intrinsic viscosity of the obtained polymer. It is sufficient to measure [ri] and set the end point when [η] becomes constant.
At that time, a separating agent is added to perform separate withdrawal.

The method of adding the separating agent is not particularly limited, but the separating agent may be added alone or after being dispersed or dissolved in a polymerization solvent.

In the present invention, in order to more effectively perform layer separation by adding the separation agent, it is preferable to set the conditions during separation as follows.

The amide polar solvent/produced I remer ratio is 20 by weight.
The range is from /1 to 1/2. Preferably, such a ratio is between 20/1 and 1/1. Incidentally, this ratio may be set at the time of polymerization.

Dispersing agent/amide type abrasive solvent ratio (amide type polar solvent/
The product-remer ratio (constant) varies depending on the type of solvent and separating agent, but is generally from 2/1 to 1/1000 by weight. Incidentally, this ratio may be set at the time of polymerization.

The temperature during separation is 170 to 300°C. A particularly preferred temperature range is 190 to 290°C.

Further, the pressure during separation may be any pressure at which the polymerized molten needles and the separating agent substantially form a liquid phase, and specifically, 1.2 Yu/min.
2 to 100 Yu7 stroke 2, preferably 1.5iv/c1
1 to 30 Kfi/lx.

- For fractionation of remer, a separating agent may be added, fractionated, and taken out once the polymerization reaction has progressed to a certain degree, or even if the conditions at the time of polymerization and the time of fractionation and removal are different, the above-mentioned conditions may be used. There is no problem as long as they match. For example, the solvent//rimer ratio can be varied by adding additional solvent into the system or removing it from the system by distillation before fractional extraction.

There are no particular restrictions on the method of separate collection. For example, it is possible to selectively take out one layer of polymer or one layer of oligomer into a sample tube using one type of straw with stirring stopped or laminar stirring, or it is possible to selectively separate both layers from the bottom of the pot. It is also possible to take it out separately.

In the present invention, as a method for separating a single polymer layer and a single oligomer layer, a sensor capable of detecting both layers can also be used. These sensors detect differences in the physical properties of both layers, ie, specific gravity and viscosity.

These include dielectric constant, electrical conductivity, refractive index, light transmittance, and color difference.

It is also possible to perform separate extraction by predicting the weights of both layers in advance and measuring changes in the amount taken out or the amount remaining. There is no particular limitation to such a method as long as it allows for separate collection.

In the present invention, the separation between the polymer-rich layer and the oligomer-rich layer is usually carried out when the oligomer content (weight % of the polymer) in the polymer-containing separated liquid is 3 or less and the polymer content is completely Preferably, the content of the primer is 97% by weight or less.

Any conventional method can be used to collect the remer from the resin liquid mainly containing polymers extracted according to the present invention. For example, a purified polymer can be obtained by removing the solvent from the resin liquid by distillation or flooding, and then washing with water or a poor solvent such as acetone or methanol.

In addition, in addition to the oligomer component, the fractionated liquid mainly containing oligo9mer contains a polymerization solvent, a part of a separating agent, and a low molecular weight/
IJ Mama - Contains small amounts.

〔Effect of the invention〕

Since the polymer produced by the method of the present invention has oligomer components removed compared to those produced by conventional production methods, there are problems such as foaming during melt molding, mold corrosion, thermal stability and mechanical properties of the product. In addition, since the amount of polymerization solvent to be treated is small, the present invention simplifies post-treatment and reduces equipment investment and energy costs. The amount of solvent can be reduced to a very small amount, which is preferable from the viewpoint of environmental protection.

[Industrial application field]

The polyphenylene sulfide produced by the method of the present invention takes advantage of its low oligomer content and can be used not only for conventional molded parts for electrical and electronic equipment, automobiles, and machinery, etc.
It can be used in a wide range of applications such as sealants, films, fibers, and paints.

〔Example〕

The method of the present invention will be explained below according to examples.

Note that the logarithmic viscosity [η] of polyphenylene sulfide is 0.
At a polymer concentration of 4 g/100 JIa liquid, α-
This value was measured in chlornaphthalene at 206°C and calculated according to the formula.

In addition, the oligomer component is determined by repeatedly extracting the powdered polymer using a Soxhlet extractor using acetone as the extraction solvent for 92 hours or more until the extraction amount becomes constant, and then drying and solidifying the acetone-soluble content. In the Examples, the content of the oligomer component (x) is expressed relative to the weight of the polymer before extraction with acetone.

In addition, parts and parts in the examples are based on weight unless otherwise specified.

[Examples 1 to 5 and Comparative Examples 1 to 3] In a 181 autoclave having an outlet at the bottom of the container, 5200 g of N-methylpyrrolidone and 1560 Jil of 60% sodium sulfide flakes (12
．． 0 mole) and 8 g (0.2 mole) of sodium hydroxide were added and heated to 160℃ for 20 minutes while stirring under a nitrogen atmosphere.
It took 1.5 hours to gradually raise the temperature to 5℃, and the water was 351p.
, N-methylpyrrolidone 19Ii] was removed from the system.

Then, p-dichlorobenzene 18521I (I2,6
MoAI) was dissolved in N-methylpyrrolidone 6009,
After adding, the temperature was increased to 225℃ and maximum pressure of 3 kg7cm2 for 2 hours, and then to 265℃ and maximum pressure of 8.7! The reaction was allowed to proceed for 3 hours. After 1.5 hours at 265℃3
A small amount of the reaction mixture was sampled every 0 minutes, washed with water, filtered, and dried according to a conventional method, and the logarithmic viscosity [η] of the obtained polygo was measured. As a result, after 2 hours [
It was confirmed that η] was constant at 0.15, and after 3 hours, the amount of acid shown in Table 1 was added to 1000% of N-methylpyrrolidone.
9 was added all at once into the reaction system through a dropping tank heated to 265°C, and 10 minutes after the completion of the addition, stirring was stopped, and after being allowed to stand for an additional 1 minute, fractional extraction was started.

The extraction operation is as follows. That is, in advance, 1 was set in a container for taking out at the bottom of the taking out port, 1 minute after the stirring was stopped, the opening cross-sectional area of the taking out port was adjusted to 3 ms+, and taking out was started at the time (Tl) shown in Table 1. The removal was stopped, and then the remaining reaction mixture was poured into a container for removal, and the entire amount of the remaining reaction mixture was taken out.

The reaction mixtures taken out in K1 and K-1 were washed with water and filtered to separate the searimer, and then dried, and the weight and logarithmic viscosity of the polymers were measured separately according to a conventional procedure.

In addition, a portion of each of the polyi-i obtained from 1 and 2 was removed, and after extraction with a Soxhlet type extractor using acetone as an extraction solvent for about 5 hours, the extract was evaporated to dryness to obtain an extract. The weight of the polymer was measured, and the content of the oligomer component in the polymer was determined. In addition, the Na content in the polymer can be determined by comparing the sample with platinum melt! The sample was decomposed with sulfuric acid in a vacuum chamber, and the value determined by flame light analysis was expressed in units of ppm. This is shown in Table 1.

As shown in Table 1, it can be seen that according to the present invention, polymers with low oligomer content and low Na content can be efficiently separated and taken out.

Claims (1)

[Claims] After the polyhaloaromatic compound and the sulfidating agent are reacted in an amide polar solvent, at least one selected from organic acids and inorganic acids is added, and then a thick layer of polymer (I) and a relatively thick layer of oligomer are added. A method for producing polyphenylene sulfide, which comprises separating layer (I) or layer (II) from a produced resin liquid consisting of layer (II).