DE4311139A1 - Process for the preparation of high-molecular weight, optionally branched polyarylenesulphides - Google Patents

Abstract

The invention relates to a process for the preparation of high-molecular-weight, optionally branched polyarylene sulphides (PASs) from halogenated aromatics, alkali metal formate and sulphur with addition of alkali metal carbonate.

Description

The invention relates to a method for producing high molecular weight, optionally branched polyarylene sulfides (PAS) from halogen aromatics, alkali formate, Sulfur with the addition of alkali carbonate.

Polyarylene sulfides and their preparation are known e.g. B. US-PS 25 13 188, 31 17 620, 33 54 129, EP-OS 171 021 etc.

It has now been found that high molecular weight, given if branched polyarylene sulfides with increased melt viscosity can be obtained if one is for the Polycondensation reaction necessary sodium sulfides in generated in situ.

The invention thus relates to a method for Production of optionally branched polyarylene sulfides by the known methods

• a) 50 to 100 mol% of dihaloaromatic compounds of the formula and 0 to 50 mol% of dihaloaromatic compounds of the formula in which
  X represents mutually meta or para halo such as chlorine or bromine and
  R ^{1 is the} same or different and can be hydrogen, C ₁ -C ₄ alkyl, C ₅ -C ₁₀ cycloalkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₄ alkylaryl, C ₇ -C ₁₄ arylalkyl , wherein two mutually ortho-standing radicals R ¹ can be linked to form an aromatic or heterocyclic, up to three heteroatoms such as N, O, S and the ring and always a radical R ^{1 is} different from hydrogen and
• b) 0 to 5 mol%, preferably 0.1 to 2.5 mol%, based on the sum of the dihaloaromatic compounds of the formulas (I) and (II), of a tri- or tetrahaloaromatic compound of the formula ArX _n (III), where
  Ar is an aromatic or heterocyclic radical,
  X represents halogen such as chlorine or bromine and
  n stands for the number 3 or 4 and
• c) an organic solvent and optionally a catalyst,

characterized in that the implementation mixture Alka licarbonate and each other in stoichiometric amounts elemental sulfur and alkali formate is added.

From elemental sulfur and alkali formate in each other stoichiometric amounts form alkali in situ hydrogen sulfide.

The molar ratio of alkali hydrogen sulfide to that organic solvent c) is said to be in the range of 1: 1.5 to 1:15.  

0.5 to 1.5 mol of alkali carbonate (Na ₂ CO ₃ , K ₂ CO ₃ ) are added per mole of dihalobenzene.

The response time can be up to 48 hours is preferably between 2 and 18 hours. The Reak tion temperatures are between 150 ° C and 280 ° C. The The reaction can be carried out in various ways.

According to the invention, the alkali hydrogen sulfides necessary for the polycondensation are generated in situ from alkali formates such as HCOONa, HCOOK, HCOOLi and elemental sulfur (for example cyclooctasulfur S ₈ ) in stoichiometric ratios to one another.

The addition of the reactants can be done in several ways respectively.

The reaction can be carried out under inert gas e.g. B. N2, noble gases (Ar, Ne) can be performed. If necessary, the Implementation under increased pressure (up to 10 bar) be performed.

It can all reactants directly in the fiction be put together according to the container used or a continuous or metered addition of one or several reactants are carried out.

The processing of the implementation mixture and the insulation tion of the polyarylene sulfides he can in a known manner consequences.  

The polyarylene sulfide can be obtained directly from the reaction solution or only z. B. after adding water and / or dilute ten acids or organic solvents, preferably those with low solubility for polyarylene sulfides, are separated according to usual procedures, at for example by filtration, extraction or by Centrifuge. After separation of the polyarylene sul fids generally includes washing with water at. A wash or extraction with other washing liquids liquids that are additionally or subsequently added this laundry can be done is too possible.

The polyarylene sulfide can also, for example, by Ab distill the solvent and then a subsequent one Linen can be obtained as described above.

Depending on the proportion of alkali hydrogen sulfide that was generated in situ in the reaction solution, additional alkali carbonates (Na ₂ CO ₃ , K ₂ CO ₃ ) are added. If necessary, instead of the alkali metal carbonates, such compounds can be added which form CO ₂ alkali metal carbonates under the reaction conditions under pressure of up to 10 bar.

According to the invention, meta- or para-dihaloaromatic compounds can be used of the formula (I) or (II) can be used. In this The ratio may be meta- to para-dihaloaromatic up to 30:70.  

For the preservation of thermoplastically processable poly Phenylene sulfides are preferred p-dihaloaromatic used.

If branched polyarylene sulfides are to be produced, must have at least 0.05 mol% of a tri- or tetrahalo aromatic compounds of the formula (III) can be used.

Examples of dihalogen to be used according to the invention aromatics of formula (I) are: p-dichlorobenzene, p-dibromo benzene, 1-chloro-4-bromobenzene, 1,3-dichlorobenzene, 1,3-di bromobenzene, 1-chloro-3-bromobenzene and 1-chloro-3-bromine zol. They are alone or in a mixture with each other reversible. 1,4-dichlorobenzene and / are particularly preferred. or 1,4-dibromobenzene.

Examples of dihalogen to be used according to the invention aromatics of the formula (II) are: 2,5-dichlorotoluene, 2,5- Dichloro xylene, 1-ethyl-2,5-dichlorobenzene, 1-ethyl-2,5-di bromobenzene, 1-ethyl-2-bromo-5-chlorobenzene, 1,2,4,5-tetra methyl-3,5-dichlorobenzene, 1-cyclohexyl-2,5-dichloro-ben zol, 1-phenyl-2,5-dichlorobenzene, 1-benzyl-2,5-dichlor benzene, 1-phenyl-2,5-dibromobenzene, 1-p-tolyl-2,5-di chlorobenzene, 1-p-tolyl-2,5-dibromobenzene, 1-hexyl-2,5-di chlorobenzene, 2,4-dichlorotoluene, 2,4-dichlorxylene, 2,4- Dibromocumol and 1-cyclohexyl-3,5-dichlorobenzene. you are can be used alone or in a mixture.

Examples of tri- or Tetrahaloaromatic compounds of the formula (III) are: 1,2,3-tri chlorobenzene, 1,2,4-trichlorobenzene, 1,2,4-tribromobenzene,  1,3,5-trichloro-2,4,5-trimethylbenzene, 1,2,3-trichloro naphthalene, 1,2,4-trichloronaphthalene, 1,2,6-trichlor naphthalene, 2,3,4-trichlorotoluene, 2,3,6-trichlotoluene, 1,2,3,4-tetrachloronaphthalene. 1,2,4,5-tetrachlorobenzene, 2,2'-, 4,4'-tetrachlorobiphenyl, 1,3,5-trichlorotriazine.

Generally, any polar solvent for the reak tion are used, which is sufficiently soluble speed of organic and optionally inorganic Reactants guaranteed under the reaction conditions.

However, cyclic ureas and lactams are preferred and particularly preferably used N-alkyl lactams.

Examples of possible solvents are: N-methylcaprolactam, N-ethylcaprolactam, N-isopropyl caprolactam, N-isobutylcaprolactam, N-propylcaprolactam, N-butylcaprolactam, N-cyclohexylcaprolactam, N-methyl-2- pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrroli don, N-isobutyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N- Butyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-methyl 3-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N- Methyl-3-methyl-2-pyrrolidone, N-methyl-3,4,5-trimethyl- 2-pyrrolidone, N-methyl-2-piperidone, N-ethyl-2-piperidone, N-isopropyl-2-piperidone, N-isobutyl-2-piperidone, N-Me thyl-6-methyl-2-piperidone N-methyl-3-ethyl-2-piperidone, N-methyl-2-oxo-hexamethyleneimine, N-ethyl-2-oxo-hexame ethylene imine.  

Mixtures of the above solvents can also be used to get voted.

The polyarylene sulfides according to the invention can also be used their polymers, such as pigments and fillers for example graphite, metal powder, glass powder, quartz flour, glass fibers or carbon fibers mixed or with the additives customary for polyarylene sulfides, for example usual stabilizers or mold release agents, ver be set.

The polyarylene sulfides according to the invention can in practice Licher use find z. B. as automotive parts, Fittings, electrical parts, e.g. B. switches, electronic Boards, chemical-resistant and weather-resistant Parts and apparatus such as pump housings and pump blades wheels, caustic bath trays, sealing rings, office parts machines and telecommunications equipment, and household appliances devices, valves, ball bearing parts etc.

example

In a heated and with argon as a protective gas filled 2 l three-necked flask with reflux condenser, KPG Stirrer, internal thermometer and check valve according to Stutz 147.00 g (1 mol) of p-dichlorobenzene, 32.01 g (1 mol) sulfur, 136.02 g (2 mol) sodium formate, 79.49 g (0.75 mol) of sodium carbonate and 1 l of NMC fills. The solution was already colored in the room temperature violet. After that, she became within 3 Heated to 160 ° C for hours with constant stirring. From 90 ° C started violent development of carbon dioxide. Soon the solution changed color from blue to dark at an early stage blue to black. Then heating was continued to 20 ° C the p-dichlorobenzene then began to boil. To The evolution of carbon dioxide ceased for 1.5 hours.

The solution was kept at 20 ° C for a further 30 hours. After cooling to room temperature, the mixture was precipitated in a hydrochloric acid / water mixture (1: 2) and washed neutral with water and methanol. The polymer was then extracted with a methanol / water mixture for 3 days. Finally, it was first dried in a water jet vacuum, later in a high vacuum at 14 ° C. The yield was 79.7 g (74% of theory).
IR (KBr): 3300 to 2500 (m), 1574 (s), 1472 (s), 819 (s) cm ^-1

Claims (2)

Process for the preparation of optionally branched polyarylene sulfides by the known processes

• a) 50 to 100 mol% of dihaloaromatic compounds of the formula and 0 to 50 mol% of dihaloaromatic compounds of the formula in which
  X represents mutually meta or para halo such as chlorine or bromine and
  R ^{1 is the} same or different and can be hydrogen, C ₁ -C ₄ alkyl, C ₅ -C ₁₀ cycloalkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₄ alkylaryl, C ₇ -C ₁₄ arylalkyl , wherein two mutually ortho-standing radicals R ¹ can be linked to form an aromatic or heterocyclic, up to three heteroatoms such as N, O, S and the ring and always a radical R ^{1 is} different from hydrogen and
• b) 0 to 5 mol%, preferably 0.1 to 2.5 mol%, based on the sum of the dihaloaromatic compounds of the formulas (I) and (II), of a tri- or tetrahaloaromatic compound of the formula ArX _n (III) in which
  Ar is an aromatic or heterocyclic radical
  X represents halogen such as chlorine or bromine and
  n stands for the number 3 or 4 and
• c) an organic solvent and optionally a catalyst,

characterized in that alkali carbonate and stoichiometric amounts of elemental sulfur and alkali formate are added to each other in the reaction mixture.