JPH0749485B2 - Post-treatment method for polyarylene sulfide polymer suspension and apparatus therefor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for post-treatment of a polyarylene sulfide polymer suspension and an apparatus therefor, and more specifically, a polyarylene sulfide polymer suspension obtained by a polymerization reaction. The present invention relates to a method capable of efficiently performing a series of post-treatments of separation, washing, and drying in one post-treatment apparatus, and an apparatus suitable for performing this method.

[Problems to be Solved by Prior Art and Invention]

Conventionally, polyarylene sulfides such as polyphenylene sulfide (PPS) are
The polymer suspension obtained is manufactured through a series of post-treatment steps of separation, washing, and drying. The post-treatment carried out at this time is the so-called solvent flash method (US Pat. No. 3,956,000). ) And sieving method (JP-A-61-255,9
No. 33) is known. However, all of these methods are prone to problems such as clogging when transferring the polymer slurry, and require various equipment such as a flash tank, a vibrating screen, and a transfer pump in addition to the slurry storage tank for the processing operation. I have it. In particular, the flash method cannot remove solid impurities such as oligomers, while the sieving method has a problem that the removal rate of moisture is particularly poor, and a large finishing dryer is required.

Further, as the above-mentioned post-treatment method, there is also known an in-reaction tank evaporation method (Japanese Patent Laid-Open No. 61-136,523). However, in this method, the reaction is carried out in the reactor while the solvent is evaporated. Since it can not be performed, the batch cycle becomes long, the productivity is reduced as a result, solid impurities such as oligomers cannot be removed, and moreover, a stirring blade and a baffle suitable for both reaction and evaporation / drying Therefore, there are various problems such as insufficient treatment effect.

[Means for solving problems]

The present inventor has solved the above-mentioned problems of the prior art, in particular, while preventing clogging trouble during the transfer of slurry of polyarylene sulfide polymer, a decrease in productivity and equipment accompanying redundant post-treatment operation of batch slurry polymerization. We have conducted intensive research to develop an extremely efficient post-treatment method while suppressing an increase in cost.

As a result, when the suspension of the polyarylene sulfide polymer obtained by the polymerization reaction is post-treated, a series of treatments of separation, washing, and drying are carried out in one devised treatment device, and Find that you can achieve your goals,
The present invention has been completed.

That is, in the present invention, in the post-treatment of the polyarylene sulfide polymer suspension obtained after the completion of the polymerization reaction, the polymer suspension is provided with an outlet equipped with a sieve at the bottom and a stirring mechanism inside. It is introduced into a post-treatment device that has it and drained by a sieve, then a solvent is added to the residue in the device and washed by stirring, and then drained by a sieve, and then water is added to the residue in the device. After stirring and washing, drain with a sieve,
Then, the apparatus is heated under reduced pressure and the residue in the apparatus is dried under reduced pressure to provide a post-treatment method for a polyarylene sulfide polymer suspension, and a polyarylene sulfide polymer suspension. In a post-processing apparatus for articles, a cylindrical container body having an inverted conical bottom portion, a heating mechanism attached to the body, a stirring mechanism installed in the body, a polymer suspension provided on the upper portion of the body, and The present invention also provides a post-treatment device for a suspension of a polyarylene sulfide polymer, which is characterized by comprising a supply port for a cleaning liquid and an outlet provided with a sieve provided on a side surface of an inverted conical bottom of the main body. .

The post-treatment method of the present invention is intended for a polyarylene sulfide polymer suspension obtained by a polymerization reaction, and this polyarylene sulfide polymer suspension is obtained by an ordinary polymerization reaction. For example, dihalogenated aromatic compounds such as p-dichlorobenzene and alkali metal sulfides such as sodium sulfide and lithium sulfide in a polar solvent such as N-methyl-2-pyrrolidone (NMP) and hexamethylphosphoramide (HMPA). By polycondensation, a polymer suspension of polyarylene sulfide including polyphenylene sulfide (PPS) is obtained.

In the post-treatment method of the present invention, the thus-obtained polyarylene sulfide polymer suspension may be introduced into a post-treatment device capable of separation, washing and drying treatments, and predetermined treatments may be sequentially performed. Although various modes are conceivable as this post-processing apparatus, the above-mentioned post-processing apparatus of the present invention is preferable. An example of the post-processing apparatus of the present invention is shown in FIG. 1, and the method and apparatus of the present invention will be described based on FIG. 1 as follows.

First, the polyarylene sulfide polymer suspension obtained in a polymerization reaction tank (not shown) is extracted from the reaction tank,
This is supplied into the container body 1 from the polymer suspension supply port 3 provided in the upper portion of the cylindrical container body 1. In addition, this polymer suspension is a polyarylene sulfide polymer, NMP
And a by-product (oligomer, sodium chloride, etc.) of the polymer such as. Also, this container body 1
The bottom part 2 has an inverted conical shape, and a discharge port 5 having a sieve 4 is provided on the side surface of the inverted conical bottom part 2.

The polymer suspension supplied to the cylindrical container body 1 is drained while being sifted through the discharge port 5 with the above-mentioned sieve 4, and most of the polymerization solvent and by-products are removed, and the container body is A polyarylene sulfide polymer, a small amount of a solvent for polymerization, and a by-product remain in 1. Here, the discharge port 5 with the sieve 4 can be installed in various positions as long as it is below the container body 1.
Although it may be the lowermost end, it is usually preferable to install it at the side surface position of the inverted conical bottom portion 2. A valve 7 is attached to the discharge port 5 so that it can be opened and closed. The inverted conical bottom 2
It is preferable to provide an outlet 6 for the dried polymer finally obtained after the post-treatment at the lowermost position.

Next, the residue in the container main body 1 is mixed with a solvent, preferably a solvent compatible with water (NMP, NMP,
(HMPA, acetone, methanol, etc.) is added, and this is thoroughly stirred and washed by a stirring mechanism 9 installed in the main body 1, for example, a stirring blade, and then sieved and discharged from a discharge port 5 with a sieve 4. Subsequently, water is used instead of the solvent, and the cleaning liquid supply port 8
In addition to the residue in the container main body 1 as described above, washing with sufficient stirring is performed in the same manner as described below, and the liquid is sieved and discharged from the discharge port 5. The cleaning liquid supply port 8 is the polymer suspension supply port 3 described above.
However, it is usually provided as a dedicated supply port as shown in FIG.

Thus, when thoroughly washed with a solvent and water and sieved and drained, the solvent for polymerization (such as NMP), the solvent for washing and by-products are distilled off in the drained liquid, so that the residue of the container body 1 is , A polyarylene sulfide polymer containing a small amount of water.

Then, the container body 1 is heated under reduced pressure to dry the above-mentioned residue under reduced pressure. Although various heating mechanisms may be attached to the container body 1, as shown in FIG. 1, a jacket 11 is provided so as to surround the container body 1,
A mechanism to heat by passing a heat medium through it,
The structure and operation are simple and convenient. In this heating, the inside of the container body 1 was depressurized and heated by a heating mechanism while stirring, and if necessary, it was heated from the lower end position of the inverted conical bottom part 2 or further from the outlet 6 at the lowermost position. It is also effective to feed in an inert gas (such as nitrogen).

After performing the drying under reduced pressure, it may be cooled and the dried polyarylene sulfide polymer may be extracted from the outlet 6.
The outlet 6 is preferably provided with a valve 12 so that it can be opened and closed as desired.

〔Example〕

 Next, the present invention will be described in more detail based on examples.

Example Polyphenylene sulfide (PPS) 102 kg, N-methyl-2
-Pyrrolidone (NMP) 429kg, Sodium chloride (NaCl) 122
A PPS suspension consisting of 9 kg and oligomers 9 kg was fed into the container body 1 (volume of 1 m ³ ) of the apparatus as shown in FIG. 1 through the suspension feed port 3 and, at the same time, at the discharge port 5 with the sieve 4. The liquid was drained while sieving.

Next, 350 kg of NMP as a solvent was poured into the residue of the container body 1 from the cleaning liquid supply port 8, stirred for 30 minutes to thoroughly wash, and then drained from the discharge port 5 with the sieve 4 by sieving.

Furthermore, deionized water is added to the residue in the container body 1 washed with a solvent.
0 kg was injected from the cleaning liquid supply port 8, stirred for 30 minutes to thoroughly wash, and then drained through a discharge port 5 equipped with a sieve 4 through a sieve. This washing with pure water and drainage were repeated three times.

After that, the temperature of the heat medium passing through the jacket 11 is 140 ° C.
At the same time, heated nitrogen at 140 ° C. was blown at a rate of 1 m ³ / hr from the outlet 6 at the bottom bottom of the container body 1. The above condition is maintained for 3 hours under the reduced pressure of 100 torr. In the container body 1 to dry the residue in the container body 1 and to make the PP of almost pure frame.
It was designated as S, cooled, and then extracted from the outlet 6.

The obtained PPS had almost no impurities and was highly pure PPS flakes. When this PPS flake was molded, a very white pellet was obtained.

When performing this series of post-processing operations, there were no blockage troubles, and the operations could be performed smoothly without paying particular attention.

〔The invention's effect〕

According to the present invention, since the post-treatment operation of the polyarylene sulfide polymer suspension can be performed in one device, it is possible to prevent the clogging trouble during the transfer of the polymer suspension,
It is possible to improve productivity and reduce repair costs. Further, since the device and the operation can be simplified, the productivity can be improved and the equipment cost can be reduced. Moreover, the obtained polyarylene sulfide is a sufficiently purified product and has a high purity, and when molded, it becomes a very white pellet.

Therefore, the present invention can be effectively applied to a post-treatment of a slurry type polymerization reaction including a post-treatment of a suspension of a polyarylene sulfide polymer, and its industrial value is extremely high.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing the cross-sectional shape of an example of the device of the present invention. In the figure, 1 is a cylindrical container body, 2 is an inverted conical bottom, 3 is a polymer suspension supply port, 4 is a sieve, 5 is a discharge port with a sieve, 6 is an outlet, 7 is a valve, 8
Is a cleaning liquid supply port, 9 is a stirring mechanism, 10 is a motor, 11 is a jacket, and 12 is a valve.

Claims (2)

[Claims] 1. In the post-treatment of a polyarylene sulfide polymer suspension obtained after the completion of a polymerization reaction, the polymer suspension has a discharge port equipped with a sieve at the bottom and a stirring mechanism inside. It is introduced into a post-treatment device that has it and drained by a sieve, then a solvent is added to the residue in the device and washed by stirring, and then drained by a sieve, and then water is added to the residue in the device. After stirring and washing, the mixture is drained through a sieve, and then the apparatus is heated under reduced pressure to dry the residue in the apparatus under reduced pressure, which is a post-treatment method for a suspension of polyarylene sulfide polymer. . 2. A post-treatment device for a suspension of a polyarylene sulfide polymer, a tubular container body having an inverted conical bottom, a heating mechanism attached to the body, a stirring mechanism installed in the body, Polyarylene sulfide polymer suspension characterized in that it comprises a supply port for the polymer suspension and the washing liquid provided on the upper part of the main body, and an outlet provided with a sieve provided on the side surface of the inverted conical bottom part of the main body. Post-processing equipment for materials.