Comb polymers as blocking additives for swelling clays

Abstract

A comb polymer, in particular for use as a clay-inerting agent, including: a) at least one poly(alkylene oxide) side chain-bearing monomer unit M1 without ionic groups, b) optionally at least one cationic monomer unit MC, c) optionally at least one anionic monomer unit MA, d) optionally, at least one non-ionic monomer unit M3, wherein the molar ratio of the cationic monomer units MC to the side chain-bearing monomer units M1 is equal to or less than 10, the molar ratio of the anionic monomer units MA to the side chain-bearing monomer units M1 is less than 1, preferably equal to or less than 0.5, and the molar ratio of the non-ionic monomer units M3 to the side chain-bearing monomer units M1 is less than 5.

1 . A comb polymer, in particular for use as a clay-inerting agent, comprising:
 a) at least one poly(alkylene oxide) side chain-bearing monomer unit M1 without ionic groups,   b) optionally at least one cationic monomer unit MC,   c) optionally at least one anionic monomer unit MA,   d) optionally, at least one non-ionic monomer unit M3,   
       wherein the molar ratio of the cationic monomer units MC to the side chain-bearing monomer units M1 is equal to or less than 10, the molar ratio of the anionic monomer units MA to the side chain-bearing monomer units M1 is less than 1, and the molar ratio of the non-ionic monomer units M3 to the side chain-bearing monomer units M1 is less than 5. 
     
     
         2 . A comb polymer according to  claim 1 , wherein the side chain-bearing monomer unit M1 includes a structure of the formula I 
       
         
           
           
               
               
           
         
         wherein 
         R 1 , and R 2 , in each case independently, are H or an alkyl group having 1 to 5 carbon atoms, 
         R 3 , in each case independently, is H, an alkyl group having 1 to 5 carbon atoms, or a group with formula 
         —(CH 2 ) m —[C═O] p —X—R 4 , 
         m=0, 1 or 2, 
         p=0 or 1, 
         X, in each case independently, is —O— or —NH—, 
         R 8  is a group of the formula -[AO] n —R a    
         where A=C 2 - to C 4 -alkylene, R a  is H, a C 1 - to C 20 -alkyl group, -cycloalkyl group or -alkylaryl group, 
         and n=2-250. 
       
     
     
         3 . A comb polymer according to  claim 1 , wherein the cationic monomer unit MC in the polymer includes or consists a monomer which has a structure of the formula II, 
       
         
           
           
               
               
           
         
         wherein 
         R 5 , in each case independently, is -[D] d -[E] e —F, with 
         D=—(COO)— and/or —(CONH)—, 
         E=an alkylene group having 1 to 5 carbon atoms, 
         F=—N + R 10 R 11 R 12 , —S + R 10 R 11 R 12  and/or —P + R 10 R 11 R 12 , 
         wherein R 10 , R 11  and R 12  are independently of one another H, an aliphatic hydrocarbon moiety having 1 to 20 C atoms, a cycloaliphatic hydrocarbon moiety having 5 to 8 C atoms and/or an aryl moiety having 6 to 14 C atoms; 
         whereby 
         d=0 or 1, 
         e=0 or 1, 
         R 6 , R 7  and R 8 , in each case independently, are H or an alkyl group having 1 to 5 carbon atoms. 
       
     
     
         4 . A comb polymer according to  claim 1 , wherein the anionic monomer unit MA in the polymer includes or consists of a monomer which has a structure of the formula III, 
       
         
           
           
               
               
           
         
         wherein 
         R 13 , in each case independently, is —COOM, —SO 2 —OM, —O—PO(OM) 2  and/or —PO(OM) 2 , 
         R 14  and R 15 , in each case independently, are H or an alkyl group having 1 to 5 carbon atoms, R 16 , in each case independently, are H, —COOM or an alkyl group having 1 to 5 carbon atoms, 
         or where R 13  forms a ring together with R 16  to give —CO—O—CO—, 
         M independently from each other is H + , an alkali metal ion, an alkaline earth metal ion, a di- or trivalent metal ion, an ammonium ion and an organic ammonium group. 
       
     
     
         5 . A comb polymer according to  claim 1 , wherein the non-ionic monomer M3 has a structure of the formula IV, 
       
         
           
           
               
               
           
         
         wherein 
         R 5′ , R 6′ , R 7′  are the same as defined for R 6 , R 7  and R 8 , and m′ and p′ are the same as defined for m and p as described above in the context of the copolymer, 
         Y, in each case independently, is a chemical bond or —O—, 
         Z, in each case independently, is a chemical bond, —O— or —NH—, 
         R 20 , in each case independently, is an alkyl group, cycloalkyl group, alkylaryl group, aryl group, hydroxyalkyl group or acetoxyalkyl group, each having 1-20 carbon atoms. 
       
     
     
         6 . A comb polymer according to  claim 1 , wherein the comb polymer, with respect to the total number of monomer units present in the comb polymer, comprises:
 a) 95-100 mol-%, of the at least one poly(alkylene oxide) side chain-bearing monomer unit M 1 ,   b) 0-1 mol-%, of the at least one cationic monomer unit MC,   c) 0-1 mol-%, of the at least one anionic monomer unit MA,   d) 0-1 mol-%, of the at least one non-ionic monomer unit M3.   
     
     
         7 . A comb polymer according to  claim 1 , wherein the comb polymer, with respect to the total number of monomer units present in the comb polymer, comprises:
 a) 30-70 mol-%, of of the at least one poly(alkylene oxide) side chain-bearing monomer unit M 1 , and b) 0-1 mol-%, of the at least one cationic monomer unit MC,   c) 0-1 mol-%, of the at least one anionic monomer unit MA,   d) 30-70%, of the at least one non-ionic monomer unit M3.   
     
     
         8 . A comb polymer according to  claim 1 , wherein the comb polymer, with respect to the total number of monomer units present in the comb polymer, comprises:
 a) 10-99 mol-%, of the at least one poly(alkylene oxide) side chain-bearing monomer unit M 1 , and   b) 1-90 mol-%, of the at least one cationic monomer unit MC,   c) 0-1 mol-%, of the at least one anionic monomer unit MA,   d) 0-75 mol-% or 0 mol-%, of the at least one non-ionic monomer unit M3.   
     
     
         9 . A comb polymer according to  claim 1 , wherein the comb polymer consists of the at least one poly(alkylene oxide) side chain-bearing monomer unit M1 and, optionally, the non-ionic monomer unit M3. 
     
     
         10 . A comb polymer according to  claim 1 , wherein the comb polymer consists of the at least one poly(alkylene oxide) side chain-bearing monomer unit M1 and the at least one cationic monomer unit MC. 
     
     
         11 . A comb polymer according to  claim 1 , wherein the comb polymer is a block polymer, whereby, at least 75 mol-%, of the total number of the at least one side chain-bearing monomer units M1 are arranged in a first block of the block copolymer and wherein the block copolymer comprises a second block in which at least 75 mol-%, of the total number of the at least one cationic monomer units MC are arranged. 
     
     
         12 . A kit of parts comprising a comb polymer according to  claim 1  and a plasticizer for mineral binder compositions. 
     
     
         13 . A composition comprising a comb polymer according to  claim 1  and further comprising a mineral binder, aggregates and/or swellable clays. 
     
     
         14 . A method comprising the steps of adding to a composition comprising swellable clays (i) a comb polymer according to  claim 1  and (ii) a plasticizer for mineral binder compositions. 
     
     
         15 . A method for inerting a swellable clay and/or for reducing or inhibiting adverse effects of swellable clays on the effectiveness of dispersants in mineral binder compositions, comprising adding the comb polymer according to  claim 1  to a mineral binder composition.