Monodisperse anion exchangers

Abstract

Process for preparing monodisperse weakly basic or optionally strongly basic anion exchangers of the poly(meth)acrylamide type, the ion exchangers themselves and their use.

We claim  
     
         1 . Process for producing monodisperse weakly basic anion exchangers of the poly(meth)acrylamide type, wherein 
 a) in a first stage a monomer mixture of 
 one or more different acrylic compounds and one or more different crosslinkers or  
 one or more different monovinyl aromatic compounds and one or more different crosslinkers  
 are injected or sprayed into a liquid essentially immiscible with the monomer mixture to form droplets, the droplets are then encapsulated and polymerized, and the encapsulated and polymerized droplets are then reacted with a feed of acrylic compounds and crosslinkers in a seed-feed process and the resulting product is polymerized to form monodisperse crosslinked acrylic polymer beads or monodisperse crosslinked acryl-containing polymer beads, and  
   b) the product obtained by step a) is then introduced into a liquid amine of the diamine type to form a suspension, the suspension is heated to temperatures above 100° C., optionally distilled, stirred for several hours, and the resulting aminated bead polymer is washed amine-free.    
     
     
         2 . Process for producing monodisperse weakly basic anion exchangers of the poly(meth)acrylamide type according to  claim 1  wherein 
 a) in a first stage a monomer mixture of 
 one or more different acrylic compounds and one or more different crosslinkers is injected or sprayed into a liquid essentially immiscible with the monomer mixture to form droplets, the droplets are then encapsulated and polymerized, and the encapsulated and the polymerized droplets are then reacted according to step b).  
 
 
     
     
         3 . Process according to  claim 1 , wherein the monodisperse crosslinked acrylic polymer beads or monodisperse crosslinked acryl-containing polymer beads in process step a) are produced by a combination of spraying (jetting), encapsulation and polymerization.  
     
     
         4 . Process according to  claim 1  or  2 , wherein said polymerization of said encapsulated droplets is a partial polymerization or a complete polymerization.  
     
     
         5 . Process according to claims  1  or  2 , wherein the droplets are microencapsulated with a complex coacervate.  
     
     
         6 . Process according to  claim 5 , wherein the droplets are microenclapsulated in the presence of a protecting colloid.  
     
     
         7 . Process according to claims  1  or  2 , wherein the polymerization of the encapsulated droplets is carried out in the presence of at least one initiator.  
     
     
         8 . Process according to claims  1  or  2 , wherein the monomer mixture further comprises porogens and the droplets, after polymerization, form macroporous crosslinked bead polymers.  
     
     
         9 . Process according to claims  1  or  2 , wherein said liquid essentially immiscible with the monomer mixture is water.  
     
     
         10 . Process according to  claim 6 , wherein said protecting colloid is selected from the group consisting of gelatin, starch, polyvinylalcohol, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid copolymers of (meth)acrylic acid and copolymers of (meth)acrylic esters.  
     
     
         11 . Process according to claims  1  or  2 , wherein said crosslinkers are selected from the group consisting of divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene, trivinylnaphthalene, 1,7-octadiene, 1,5-hexadiene, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate and diethylene glycol divinyl ether.  
     
     
         12 . Process according to  claim 7 , wherein the initiator is a peroxy compound or an azo compound.  
     
     
         13 . Process according to  claim 12 , wherein said peroxy compound is a member of the group consisting of dibenzoyl peroxide, dilauroyl peroxide, bis(p-chlorobenzoyl) peroxide, dicyclohexyl peroxydicarbonate, tert-butyl peroctoate, tert-butyl peroxy-2-ethylhexanoate, 2,5-bis(2-ethyl-hexanoylperoxy)-2,5-dimethylhexane and tert-amylperoxy-2-ethylhexane, and said azo compound is a member of the group consisting of 2,2′-azobis(isobutyronitrile) and 2,2′-azobis(2-methylisobutyronitrile).  
     
     
         14 . Process according to claims  1  or  2 , wherein said liquid amine of the diamine type is selected from the group consisting of 1-amino-3-dimethylaminopropane, diethylenetriamine and triethylenetetramine.  
     
     
         15 . Process for preparing strongly basic monodisperse anion exchangers of the poly(meth)acrylamide type containing quaternary amino groups, which comprises reacting the aminated bead polymer of claims  1  or  2 , process step b) with alkylhalides or arylhalides.  
     
     
         16 . Process of  claim 15 , wherein said alkylhalides or arylhalides are selected from the group consisting of chloromethane, benzyl chloride or mixtures of chloromethane and benzyl chloride  
     
     
         17 . Weakly basic monodisperse anion exchangers of the poly(meth)acrylamide type obtained by 
 a) injecting or spraying a monomer mixture of one or more different acrylic compounds and one or more different crosslinkers or one or more monovinyl aromatic compounds and one or more crosslinkers into a liquid which is essentially immiscible with the monomer mixture, to form droplets, encapsulating and polymerizing said droplets and then reacting them with a feed of acrylic compounds and crosslinkers according to a seed-feed process to produce monodisperse crosslinked acrylic polymer beads or monodisperse crosslinked acryl-containing polymer beads, and    b) the product obtained by step a) is then introduced into a liquid amine of the diamine type, heating the suspension to temperatures above 100° C. and stirring for a several hours, and washing the aminated bead polymer until it is amine-free.    
     
     
         18 . Weakly basic monodisperse anion exchangers of the poly(meth)acrylamide type obtained by 
 a) injecting or spraying a monomer mixture of one or more different acrylic compounds and one or more different crosslinkers into a liquid which is essentially immiscible with the monomer mixture, to form droplets, encapsulating and polymerizing said droplets and then    b) introducing the product obtained by step a) into a liquid amine of the diamine type, heating the suspension to temperatures above 100° C. and stirring for a several hours, and washing the aminated bead polymer until it is amine-free.    
     
     
         19 . Process according to  claim 1 , wherein in process step a) the monovinyl aromatic compound is styrene and the crosslinker is divinylbenzene.  
     
     
         20 . Strongly basic monodisperse anion exchangers of the poly(meth)acrylamide type obtained by reacting the aminated bead polymer from process step b) of either  claim 1  or  claim 2  partially or completely with alkyl halides or aryl halides to give strongly basic monodisperse anion exchangers of the poly(meth)acrylate type containing quaternary amino groups.  
     
     
         21 . Process for removing anions, color particles or organic components from aqueous or organic solutions and condensates, which comprises contacting said aqueous or organic solutions and condensates with the monodisperse weakly basic or strongly basic anion exchangers of claims  17 ,  18  or  20 .  
     
     
         22 . Method of purifying and treating water of the chemical industry and the electronic industry which comprises contacting said water with the monodisperse strongly basic or weakly basic anion exchangers of claims  17 , 18  or  20 .  
     
     
         23 . Method of demineralizing aqueous solutions and/or condensates which comprises contacting said aqueous solutions and/or condensates with the monodisperse strongly basic or weakly basic anion exchangers of claims  17 , 18  or  20  in combination with gel-type and/or macroporous cation exchangers.  
     
     
         24 . Combinations of monodisperse strongly basic or weakly basic anion exchangers of the poly(meth)acrylamide type according to claims  17 , 18  or  20  together with gel-type and/or macroporous cation exchangers.  
     
     
         25 . The process of  claim 1 ,  2 ,  17  or  18  wherein said temperature is 160° C. to 200° C.