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Basic saponifying method for crosslinked acrylonitrile bead polymer

A technology of acrylonitrile beads and polymers, applied in chemical instruments and methods, ion exchange, cation exchange, etc., can solve the problem of coloring of eluate

Active Publication Date: 2007-10-10
LANXESS DEUTDCHLAND GMBH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The use of the resins in EP-A 0406 648 can lead to discoloration of the eluate under certain application conditions, e.g. if severe oxidation and / or thermal stress are present

Method used

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  • Basic saponifying method for crosslinked acrylonitrile bead polymer
  • Basic saponifying method for crosslinked acrylonitrile bead polymer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Embodiment 1 (invention)

[0043] 1.1. Preparation of acrylonitrile bead polymer

[0044] The polymerization was carried out in a 3 liter glass vessel with a flat bottom flange, a wide stirrer designed for vessels with a flat bottom flange, a Pt100 temperature sensor, a reflux condenser, a 500 ml dropping funnel and a control Unit's constant temperature bath.

[0045] 1.184g

Hydroxyethyl cellulose

126ml

Deionized water (DI water)

196.8g

Sodium Chloride (Technical Grade)

592ml

DI water

0.414g

Sodium salt of naphthalenesulfonic acid-formaldehyde condensate (95% strength)

77ml

DI water

[0046] 760g

Acrylonitrile

40g

Diethylene glycol divinyl ether

2.13g

Dibenzoyl peroxide (75% concentration)

[0047] The hydroxyethylcellulose was sprinkled into DI water (deionized water) and stirred for at least 8 hours before preparing the aqueous phas...

Embodiment 2

[0073] Embodiment 2 (comparative example)

[0074] 2.1 Preparation of acrylonitrile bead polymer

[0075] Repeat Example 1.1

[0076] 2.2 Alkaline saponification reaction

[0077] 500ml

Resin (wet, obtained by suction filtration)

727ml

DI water

143ml

NaOH, 45% concentration (Part 1)

655ml

NaOH, 45% concentration (Part 2)

150ml

DI water

670ml

DI water

[0078] First add resin and water into the autoclave, and heat to 150°C. The first portion of NaOH was pumped in over 120 minutes. Then, a second portion of NaOH was added over 100 minutes, followed quickly by 150 ml of water. Stirring was continued at 150°C for 3.5 hours. During the pumping-in phase and the continued stirring phase, the pressure is kept at no more than 4.5 bar. The ammonia formed was decompressed through a glass receiver into which water had been added. Once stirring had ceased, the mixture was cooled to 100° C. and then depr...

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PUM

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Abstract

The alkaline saponification of acrylonitrile bead polymers provides weakly acidic cation exchangers with little intrinsic color and with reduced residual nitrogen content if the saponification is begun at a temperature T1 of from 70 to 120 DEG C. and, once a degree of saponification of at least 65% has been reached, is completed at a temperature T2 of from 120 to 180 DEG C.

Description

technical field [0001] The present invention relates to the alkaline saponification of crosslinked acrylonitrile bead polymers, ie bead polymers whose preparation process is based on acrylonitrile, and to the use of these saponified acrylonitrile bead polymers as weakly acidic cation exchangers. Background technique [0002] It is known to prepare weakly acidic cation exchangers by hydrolysis of crosslinked acrylonitrile bead polymers. This reaction converts the nitrile groups of the polymer into carboxylic acid groups. Acidic or basic solutions can be used to induce the hydrolysis process. The acidic hydrolysis reaction involves a strong and sudden exotherm, is difficult to control under industrial conditions, and is not environmentally friendly due to the need to handle or dispose of large amounts of spent acid containing ammonium salts. In contrast, the alkaline saponification method has the advantage that the process can be easily controlled by adding an alkaline solut...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F20/44C08F8/12C08J5/20B01J39/20B01J39/18C08F8/44
CPCB01J39/20C08F8/12C08F2810/20C08F8/44C08F220/44C08F216/125
Inventor M·哈普D·厄姆斯西尔W·珀兹森R·西德尔W·扎格斯
Owner LANXESS DEUTDCHLAND GMBH