Kureha Corporation

Hirohito Kawama

Hiroyuki Sato

Koichi Suzuki

Michihisa Miyahara

Mitsuhiro Matsuzaki

Masanori Kobayashi

Shigeru Suzuki

Tomoyoshi Koizumi

Nobuo Sato

The present invention is a production method for producing polyarylene sulfide, wherein an unreacted dihalo aromatic compound is recovered and reused. The present production method includes: (a) a polymerization step; (b) a separation step; and (c) a recovery step of recovering unreacted dihalo aromatic compound from a water-containing mixture of the separated liquid by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water. Alternatively, the production method includes: (a) a polymerization step; (d) a dehydration step; and (c) a recovery step of recovering unreacted dihalo aromatic compound from a water-containing mixture of a water-containing liquid mixture and/or a water-containing steam mixture containing a raw material mixture and/or a polymerization reaction solution by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water in the dehydration step.

Polyarylene sulfide production method and polyarylene sulfide produced using production method

The present invention provides a production method and a production apparatus for a polyarylene sulfide (PAS), thus the formation of a floating polymer and the leakage of the floating polymer to the outside of the vessel in a washing step are prevented, to achieve steady production of the polymer with high quality, to improve the yield of the polymer and to reduce environmental load, wherein the floating polymer refers to a particles of the polymer which are floating on the surface of a washing solution, in the upper part of the inside of a washing vessel, as a result of the adhesion of a gas onto the surface of the particles of the polymer. The present invention provides a production method for a PAS comprising step (I), performing polymerization, step (II), separating and collecting a polymer, step (III), washing a slurry, and step (IV), collecting the polymer after washing, wherein an aqueous medium is sprayed onto a PAS floating on the surface of the aqueous washing solution in the upper part of the inside of the washing vessel in step (III) (step (IIIa), washing a slurry using a counter current, and/or step (IIIb), treating a slurry with acid using a counter current, or the like); and a production apparatus for a PAS comprising a washing device (counter current washing device and/or a counter current contact/acid treatment device or the like) having an aqueous medium spray means.

Polyarylene sulfide production method and polyarylene sulfide production apparatus

In a process for producing a poly(arylene sulfide) by polymerizing a sulfur source and a dihalo-aromatic compound in the presence of an alkali metal hydroxide in an organic amide solvent, the production process comprises washing a polymer obtained by the polymerization with a hydrophilic organic solvent containing water in a proportion of 1 to 30% by weight, thereby collecting a purified polymer, the content of nitrogen contained in an extract extracted by a mixed solvent containing 40% by weight of acetonitrile and 60% by weight of water from the purified polymer is at most 50 ppm on the basis of the weight of the polymer, and a poly(arylene sulfide), the content of nitrogen contained in an extract extracted by a mixed solvent containing 40% by weight of acetonitrile and 60% by weight of water from the purified polymer is at most 50 ppm on the basis of the weight of the polymer.

Poly (arylene sulfide)

A poly(arylene sulfide) having properties that a melt viscosity is 1 to 3,000 Pa&#xb7;s as measured under conditions of a temperature of 310&#xb0; C. and a shear rate of 1,216 sec, a pH is 7.0 to 12.0 as measured in a mixed solvent of water/acetone (volume ratio=2/1), a crystallization temperature is at most 220&#xb0; C. as measured in the course of lowing the temperature of the polymer at a rate of 10&#xb0; C./min from a molten state, and a whiteness degree is at least 70 as measured in the form of a melt molded or formed product, and a production process thereof.

Poly (arylene sulfide) and production process thereof

A process for producing a poly(arylene sulfide) including a charging step 1 of preparing a charging mixture containing an organic amide solvent, a sulfur source, an alkali metal hydroxide, water and a dihalo-aromatic compound and having a pH of at least 12.5; a first-stage polymerization step 2 of heating the mixture to initiate a polymerization reaction, thereby forming a prepolymer that a conversion of the dihalo-aromatic compound is at least 50%; and a second-stage polymerization step 3 of adding a phase separation agent into the reaction system and adding an alkali metal hydroxide in an amount corresponding to 1 to 10 mol % per mol of the charged sulfur source at a time or in portions, thereby continuing the polymerization reaction.

Production process of poly(arylene sulfide)

A dehydration step is conducted by heating a mixture containing an organic amide solvent and a sulfur source including an alkali metal hydrosulfide, and a part of an overall charged amount of an alkali metal hydroxide as needed. The mixture remaining within the system after the dehydration step is mixed with a dihalo-aromatic compound, the resultant mixture is heated to conduct a polymerization reaction, and the alkali metal hydroxide is added to the mixture for polymerization reaction continuously or in portions to control the pH of the mixture for polymerization reaction within a range of from 7 to 12.5 from the beginning to the end of the polymerization reaction. The poly(arylene sulfide) according to the present invention has a nitrogen content of at most 800 ppm.

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Tokyo, Japan

Hirohito Kawama