WO2001085808A1

WO2001085808A1 - Stabilisation of polystyrenesulphonic acids with transition metal ions

Info

Publication number: WO2001085808A1
Application number: PCT/EP2001/004847
Authority: WO
Inventors: Burkhard KÖHLER; Ralf-Jürgen Born; Eckhard Wenz
Original assignee: Bayer Aktiengesellschaft
Priority date: 2000-05-09
Filing date: 2001-04-30
Publication date: 2001-11-15
Also published as: DE10022496A1; AU5482201A

Abstract

The invention relates to polymers based on polystyrenesulphonic acids, stabilised by means of transition metal ions, the use thereof as cationic ion exchangers and cationic ion exchangers made from the above polymer.

Description

Stabilization of polystyrene sulfonic acids with transition metal ions

The invention relates to stabilized bead polymers based on polystyrene sulfonic acids by means of transition metal ions, preferably with transition metal ions

Series Fe, Co, Cu, Ni, Mn, particularly preferably with iron QI) or iron (III) ions.

The thesis is represented in the specialist literature that, for example, iron ions are responsible for the stability of bead polymers made of polystyrene sulfonic acid, as they are usually called

Reduce ion exchangers, preferably as cation exchangers, compared to oxidative attack. Bibler et al. in Ind. Eng. Chem., Prod. Res. Dev., Vol. 15, No. 2, 1976, pages 136-138 the dissolution of polystyrene sulfonic acid-based cation exchangers with oxidizing agents in the presence of iron (II) or iron (III) ions.

The object of the present invention was to provide soluble polymers and / or crosslinked bead polymers based on polystyrene sulfonic acids stabilized against transition metal ions, in particular polystyrene sulfonic acids stabilized against iron ions, so that the oxidative attack of those soluble therefrom

Polymers and / or crosslinked bead polymers prepared cation exchanger is prevented or at least reduced.

Surprisingly, and thus in contrast to the literature reference mentioned above, it has now been found that special transition metal ions, preferably iron ions, even improve the stability of polystyrene sulfonic acids.

The invention therefore relates to soluble polymers or crosslinked bead polymers which are composed of at least 80% by weight of repeating units of the general formula (I)

in which

R ^{1 represents} hydrogen, methyl or ethyl, preferably hydrogen,

R ^{2 represents} hydrogen or methyl, preferably hydrogen, and

metal cations or protons may be present as counterions for the sulfonate groups, characterized in that 0.001% to 50%, preferably 0.01% to 5%, of the sulfonate groups by transition metal ions, preferably by transition metal ions of the series Fe, Co, Cu, Ni, Mn, are particularly preferably neutralized by Fe ²⁺ , Fe ³⁺ , Mn ²⁺ , Ni ²⁺ , Cu ²⁺ or Co2 ⁺ .

The invention further relates to a process for stabilizing soluble polymers or crosslinked bead polymers, which at least include

80% by weight of repeating units of the general formula (I) are built up by means of Fe, Co, Cu, Ni or Mn ions and the use of iron, manganese, nickel, copper or cobalt salts for stabilization of soluble or crosslinked bead polymers which are composed of at least 80% by weight of repeating units of the formula (I).

The linear, soluble polymers to be stabilized by the transition metals, but also the crosslinked bead polymers, can be obtained by polymerizing styrene or on the core or at the α-position alkylated styrenes with optionally other comonomers and subsequent sulfonation or by polymerizing styrene sulfonic acid with optionally other comonomers. Examples of suitable non-crosslinking comonomers for styrene or for alkylated styrenes are:

Acrylonitrile, methacrylonitrile, -C-C6- (meth) acrylates, vinyl pyridines, N-vinyl pyrrolidone, maleic anhydride, (meth) acrylic acid, (meth) acrylamide or ethyl styrenes.

In the subsequent sulfonation, the functional groups of the non-crosslinking groups can be hydrolyzed or sulfonated in whole or in part if possible.

The crosslinking comonomers used are, for example, divinylbenzenes, for example, which are partially or fully sulfonated during the sulfonation.

Water-soluble vinyl compounds are preferably used as comonomers for styrene sulfonic acid.

The soluble polymers to be stabilized according to the present invention are prepared by sulfonating the corresponding styrene polymers with sulfonating reagents, such as e.g. Sulfuric acid in the presence or absence of organic or inorganic acid anhydrides and / or organic solvents at temperatures of 20 ° C to 125 ° C or chlorosulfonic acid in or

Absence of organic solvents at 20 ° C to 125 ° C, or by (co) polymerizing styrene sulfonic acid.

The crosslinked bead polymers to be stabilized according to the invention can, for example, according to DE-A 19 852 667 or by jetting, seed / feed or

Direct atomization according to EP-A 0 098 130, EP-A 0 101 943, US 4,444,961, US 3,922,255 or US 4,427,794 can be produced.

The soluble polymers or crosslinked polymers are loaded by adding the appropriate amount of an aqueous solution of iron, manganese, nickel, copper or iron to the solution or suspension of the polymers Cobalt salts. For example, in the context of the present invention, the salts iron (II) chloride, iron (IÜ) chloride, iron (II) sulfate, iron (III) sulfate, iron (III) nitrate, iron (II) bromide, iron (III) bromide , Iron (II) iodide, iron (LI) - or - (IU) carboxylate, iron (LI) - or - (III) sulfonate, manganese (II) chloride, manganese (II) bromide, manganese (II) iodide , Manganese (II) carboxylates, manganese (II) sulfonates, nickel (II) chloride,

Nickel (II) bromide, nickel (II) iodide, nickel (II) carboxylate, nickel (II) sulfonate, nickel (II) nitrate, cobalt (π) chloride, cobalt (II) bromide, cobalt (II) iodide,

Cobalt (II) carboxylate, cobalt (II) sulfate, cobalt (II) sulfonate, cobalt (II) nitrate, copper (I) chloride ₅ copper (II) chloride, copper (I) bromide, copper (II) bromide, copper ( I) iodide, copper (II) nitrate, copper (I) sulfate, copper (II) sulfate,

Copper (I) carboxylates, copper (II) carboxylates, copper (I) sulfonates, copper (II) sulfonates can be used. The soluble polymers or the crosslinked polymers can be used, for example, in their H form (H ⁺ as counterion for the sulfonate group) or alkali metal form, but preferably in the H form.

The polymers stabilized according to the invention (also applies to the linear ones) are prepared by dissolving or suspending the polymers in 1 to 100 times the amount of water and adding a 0.01 to 10 percent solution of the Fe, Co and Cu , Ni or Mn salts in water at 0 ° C to 100 ° C, being 0.00001 to 0.5, preferably to one equivalent of the repeating unit of the general formula (I)

0.0001 to 0.05 equivalents of Fe, Co, Cu, Ni or Mn cations can be used. The amounts used are given here in equivalents and not in moles, since the cations can occur in different charge levels. For example, one Fe ²⁺ ion neutralizes two and one Fe ³⁺ ion three sulfonate repeat units in the bead polymer to be stabilized.

The linear stabilized polymers or crosslinked and stabilized bead polymers according to the invention are distinguished by a resistance which is markedly improved in relation to oxidizing agents, such as, for example, oxygen, hydrogen peroxide, organic or inorganic peroxides, halogens, hypochlorites, chlorites, chlorates, nitric acid or air. The crosslinked and stabilized bead polymers according to the invention are therefore particularly suitable for use as cation exchangers, where they contribute to protecting the cation exchangers against oxidizing agents of the series oxygen, hydrogen peroxide, organic or inorganic peroxides, halogens, hypochlorites, chlorites, chlorates, nitric acid or air.

Another object of the invention is therefore the use of the bead polymers crosslinked and stabilized according to the invention as cation exchangers, which are synthesized from crosslinked polymers by stabilizing with transition metal ions according to the present invention, and the protection of the cation exchangers from oxidizing agents of the series mentioned above by neutralizing 0.001%. to 50%, preferably 0.01% to 5% of the sulfonate groups with transition metal ions.

The invention furthermore relates to cation exchangers produced from crosslinked polymers which contain at least 80% by weight of repeat units of the general formula (I)

in which

R ^{1 represents} hydrogen, methyl or ethyl, preferably hydrogen,

R ^{2 represents} hydrogen or methyl, preferably hydrogen and metal cations or protons can be present as counterions for the sulfonate groups and 0.001% to 50%, preferably 0.01% to 5% of the sulfonate groups by transition metal ions, preferably by transition metal ions of the series Fe, Co, Cu, Ni, Mn, particularly preferably by Fe ²⁺ , Fe ³⁺ , Mn ²⁺ , Ni ²⁺ , Cu ²⁺ or Co2 ^{+ are} neutralized.

The present invention further relates to the use of the cation exchanger according to the invention for removing cations, color particles or organic components from aqueous or organic solutions and condensates, such as e.g. Process or

Turbine condensates, for softening in the neutral exchange of aqueous or organic solutions and

Condensates, e.g. Process or turbine condensates, for cleaning and processing water from the chemical industry, electronics industry and from power plants, for the complete desalination of aqueous solutions and / or condensates in combination with gel-like and / or macroporous anion exchangers, for decolorization and desalination of whey, thin gelatin broths, fruit juices,

Fruit must and watery solutions of sugars.

The present invention therefore also relates to the subject

Process for softening by neutral exchange of aqueous or organic solutions and condensates, e.g. Process or turbine condensates using the cation exchanger according to the invention,

Process for cleaning and processing water from the chemical, electronics and power plants using the cation exchanger according to the invention, Processes for the removal of cations, color particles or organic components from aqueous or organic solutions and condensates, such as process or turbine condensates, using the cation exchangers according to the invention,

Process for the complete desalination of aqueous solutions and / or condensates, e.g. Process or turbine condensates using the cation exchanger according to the invention in combination with heterodisperse or monodisperse, gel-like and / or macroporous anion exchangers and

Process for decolorization and desalination of whey, thin gelatin broths, fruit juices, fruit must and aqueous solutions of sugar in the sugar, starch or pharmaceutical industry or dairies using the cation exchanger according to the invention.

Examples

Production of a soluble polystyrene sulfonic acid with a molecular weight of approx. 100,000 g / mol (measured by GPC)

The solution of 10 g of polystyrene with a molar mass of approx. 55,000 g / mol in 90 g of methylene chloride is mixed with 14 g of sulfuric acid (98%) and 15 g of acetic anhydride and left to stand at room temperature for 2 weeks.

The Cfl ^ C ^ phase is decanted off, the residue is dissolved in 30 ml of methanol and precipitated in 150 ml of diethyl ether. The precipitated product is washed three times with diethyl ether and dried.

It is passed through the solutions of 500 mg of polystyrene sulfonic acid each with a molar mass of approx. 100,000 g / mol in 20 ml of water for 10 days at 100 ° C. air.

The following amount of a 0.1 percent solution of iron (πi) chloride in water was added to the solutions:

A) 0 mg

G) 5 mg

D) 50 mg

H) 500 mg

I) 5000 mg.

The molecular weight was measured by GPC with infrared detection after 10 days of storage.

The molar masses (maximum of the distribution curve) were A) 20,000 g / mol

G) 25,000 g / mol D) 60,000 g / mol H) 90,000 g / mol I) 100,000 g / mol (no degradation)

Contrary to expectations, the solutions show a lighter color and a higher molar mass (less degradation) with increasing iron content.

Claims

claims

1. Soluble polymers or crosslinked bead polymers which are composed of at least 80% by weight of repeating units of the general formula (I)

in which

R ^{1 represents} hydrogen, methyl or ethyl,

R ^{2 represents} hydrogen or methyl and

metal cations or protons may be present as counterions for the sulfonate groups, characterized in that 0.001% to 50% of the sulfonate groups are neutralized by transition metal ions.

Soluble polymers or crosslinked bead polymers according to claim 1, characterized in that R ¹ and R ² each represent hydrogen.

Soluble polymers or crosslinked bead polymers according to claims 1 and 2, characterized in that transition metal ions of the series Fe, Co, Cu, Ni or Mn are used for stabilization.

4. Soluble polymers or crosslinked bead polymers according to claim 3, characterized in that Fe ²⁺ , Fe ³⁺ , Mn ²⁺ , Ni ²⁺ , Cu ²⁺ or Co ²⁺ are used as transition metal ions.

5. Use of iron, manganese, nickel, copper or cobalt salts for stabilizing soluble polymers or crosslinked bead polymers against oxidative degradation, characterized in that these contain at least 80% by weight of repeat units of the formula (I) according to claim 1 are constructed.

6. Use of iron, manganese, nickel, copper or cobalt salts according to claim 5, characterized in that these neutralize 0.001% to 50% of the sulfonate groups in bead polymers which are composed of polystyrene sulfonic acid by the respective cation.

7. Use of the crosslinked and stabilized bead polymers according to claim 1 as a cation exchanger.

8. A method for protecting cation exchangers against oxidation agent, characterized in that they are synthesized from crosslinked polymers according to claim 1.

9. Use of the crosslinked and stabilized bead polymers according to claim 1 as a cation exchanger which is oxidizing agents of the series oxygen, hydrogen peroxide, organic or inorganic

Peroxides, halogens, hypochlorites, chlorites, chlorates, nitric acid or air are protected.

10. Process for stabilizing bead polymers which are composed of at least 80% by weight of repeating units of the general formula (I)

wherein

R ^{1 represents} hydrogen, methyl or ethyl,

R ^{2 represents} hydrogen or methyl,

characterized in that the solution or suspension of the polymers in 1 to 100 times the amount of water with a 0.01 to 10% solution of the Fe, Co, Cu, Ni or Mn salts in water at 0 ° C to 100 ° C is added and 0.00001 to 0.5 equivalents of Fe, Co, Cu, Ni or Mn cations are used for one equivalent of the repeating unit of the general formula (I).

11. Cation exchanger made from crosslinked and stabilized bead polymers which contain at least 80% by weight of repeating units of the general formula (I)

are built up in what R ^{1 represents} hydrogen, methyl or ethyl,

R ^{2 represents} hydrogen or methyl and

metal cations or protons may be present as counterions for the sulfonate groups and 0.001% to 50% of the sulfonate groups are neutralized by transition metal ions.