Silane-modified binder dispersions

Abstract

The invention relates to aqueous formulations comprising silane-modified polymeric binders having a siloxane content and inorganic nanoparticles, a process for the preparation thereof and the use thereof for the preparation of aqueous coating compositions.

1 . An aqueous formulation comprising
 A) a silane-modified copolymer a1) and a polyorganosiloxane a2) containing hydroxyl groups;   B) optionally surface-modified inorganic particles having an average particle size (z-mean), as determined by means of dynamic light scattering in dispersion, of less than 200 nm; and   C) water.   
   
   
       2 . The aqueous formulation of  claim 1 , wherein said silane-modified copolymer a1) comprises groups of general formula (1)
   —Si(R 1 O) 2 R 2   (1)   wherein   R 1  is a C 2 - to C 8 -alkyl radical; and   R 2  is (R 1 O) or a C 1 - to C 5 -alkyl radical.   
   
   
       3 . The aqueous formulation of  claim 1 , wherein said silane-modified copolymer a1) is a copolymer which is built up from
 I) a hydroxy-functional hydrophobic polymer containing as builder monomers
 Ia) (meth)acrylic acid esters having C 1 - to C 18 -hydrocarbon radicals in the alcohol part and/or vinylaromatics and/or vinyl esters; 
 Ib) hydroxy-functional monomers; and 
   IS1) silane-functional monomers capable of polymerization; and   II) a hydroxy-functional hydrophilic polymer containing as builder components
 IIa) (meth)acrylic acid esters having C 1 - to C 18 -hydrocarbon radicals in the alcohol part and/or vinylaromatics and/or vinyl esters; 
 IIb) hydroxy-functional monomers; and 
 IIe) acid-functional monomers. 
   
   
   
       4 . The aqueous formulation of  claim 1 , wherein said silane-modified copolymer a1) is a copolymer which is built up from
 I) a hydroxy-functional hydrophobic polymer containing as builder monomers
 Ia) (meth)acrylic acid esters having C 1 - to C 18 -hydrocarbon radicals in the alcohol part and/or vinylaromatics and/or vinyl esters; and 
 Ib) hydroxy-functional monomers; and 
   II) a hydroxy-functional hydrophilic polymer containing as builder components
 IIa) (meth)acrylic acid esters having C 1 - to C 18 -hydrocarbon radicals in the alcohol part and/or vinylaromatics and/or vinyl esters; 
 IIb) hydroxy-functional monomers; 
 IIc) acid-functional monomers; and 
 IIS1) sitane-functional monomers capable of polymerization. 
   
   
   
       5 . The aqueous formulation of  claim 3 , wherein said silane-functional monomer IS1), which is capable of polymerization, is a compound of the general formula (2)
   (R 1 O) 2 R 2 Si—(CH═CH 2 )  (2)   
     wherein
 R 1  is a C 2 - to C 8 -alkyl radical; and 
 R 2  is (R 1 O) or a C 1 - to C 5 -alkyl radical; 
 
     and/or a compound of the general formula (3)
   (R 1 O) 2 R 2 Si(CH 2 ) m —O(CO)—(CR 3 CH 2 )  (3) 
 
     wherein
 R 1  is a C 2 - to C 8 -alkyl radical; 
 R 2  is (R 1 O) or a C 1 - to C 5 -alkyl radical; 
 R 3  is H or CH 13 ; and 
 m is 1 to 4. 
 
   
   
       6 . The aqueous formulation of  claim 4 , wherein said silane-functional monomer IIS1), which is capable of polymerization, is a compound of the general formula (2)
   (R 1 O) 2 R 2 Si—(CH═CH 2 )  (2)   
     wherein
 R 1  is a C 2 - to C 8 -alkyl radical; and 
 R 2  is (R 1 O) or a C 1 - to C 5 -alkyl radical; 
 
     and/or a compound of the general formula (3)
   (R 1 O) 2 R 2 Si(CH 2 ) m —O(CO)—(CR 3 ═CH 2 )  (3) 
 
     wherein
 R 1  is a C 2 - to C 8 -alkyl radical; 
 R 2  is (R 1 O) or a C 1 - to C 5 -alkyl radical; 
 R 3  is H or CH 3 ; and 
 m is 1 to 4. 
 
   
   
       7 . The aqueous formulation of  claim 3 , wherein said silane-functional monomer IS1), which is capable of polymerization, is selected from the group consisting of vinyltriethoxysilane, vinyltrisisopropoxysilane, vinyl-tris-(2-methoxyethoxy)silane, vinylmethyldiethoxysilane, vinylmethyldiisopropoxysilane, vinylethyldiethoxysilane, 3-(triethoxysilyl)-propyl methacrylate or 3-(tris-isopropoxysilyl)-propyl methacrylate, vinylphenyldiethoxysilane, vinylphenylmethylethoxysilane or vinyltri-t-butoxysilane. 
   
   
       8 . The aqueous formulation of  claim 4 , wherein said silane-functional monomer IIS1), which is capable of polymerization, is selected from the group consisting of vinyltriethoxysilane, vinyltrisisopropoxysilane, vinyl-tris-(2-methoxyethoxy)silane, vinylmethyldiethoxysilane, vinylmethyldiisopropoxysilane, vinylethyldiethoxysilane, 3-(triethoxysilyl)-propyl methacrylate or 3-(tris-isopropoxysilyl)-propyl methacrylate, vinylphenyldiethoxysilane, vinylphenylmethylethoxysilane or vinyltri-t-butoxysilane. 
   
   
       9 . The aqueous formulation of  claim 1 , wherein said silane-modified copolymer a1) is a copolymer which is built up from
 I) a hydroxy-functional hydrophobic polymer containing as builder monomers
 Ia) (meth)acrylic acid esters having C 1 - to C 18 -hydrocarbon radicals in the alcohol part and/or vinylaromatics and/or vinyl esters; and 
 Ib) hydroxy-functional monomers; and 
   II) a hydroxy-functional hydrophilic polymer containing as builder components
 IIa) (meth)acrylic acid esters having C 1 - to C 18 -hydrocarbon radicals in the alcohol part and/or vinylaromatics and/or vinyl esters; 
 IIb) hydroxy-functional monomers; 
 IIc) acid-functional monomers; and 
 IIS2) monomers which contain at least one epoxide function in addition to silane groups. 
   
   
   
       10 . The aqueous formulation of  claim 9 , wherein said monomers IIS2) are selected from the group consisting of γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl-tris-isopropoxysilane, γ-glycidoxypropyl-diethoxy-methylsilane, β-(3,4-epoxycyclohexyl)-triethoxysilane, and β-(3,4-epoxycyclohexyl)-tris-isopropoxysilane. 
   
   
       11 . The aqueous formulation of  claim 1 , wherein said polyorganosiloxane a2) containing hydroxyl groups is a compound of the general formula (I) 
     
       
         
         
             
             
         
       
     
     wherein
 X is an aliphatic, optionally branched C 1  to C 10  radical or 
  a [—CH 2 —O—(CH 2 ) p —]Si unit, wherein r is an integer from 1 to 4; 
 R is a —CH(OH)Y group, wherein
 Y is a —CH 2 —N(R 2 R 3 ) group, wherein
 R 2  is H or a methyl, ethyl, n-propyl, iso-propyl, or cyclohexyl radical, or a 2-hydroxyethyl, 2-hydroxypropyl, or 3-hydroxypropyl radical; and 
 R 3  is a 2-hydroxyethyl, 2-hydroxypropyl, or 3-hydroxypropyl radical, 
 
 
 R 1  is, identically or differently, H or a C 1 - to C 10 -hydrocarbon radical optionally containing hetero atoms; and 
 n is an integer from 1 to 40. 
 
   
   
       12 . The aqueous formulation of  claim 1 , wherein said polyorganosiloxane a2) containing hydroxyl groups is a compound of the general formula (V) 
     
       
         
         
             
             
         
       
     
     wherein
 m is an integer from 5 to 15; 
 Z is H or methyl; and 
 n and o is an integer from 1 to 12. 
 
   
   
       13 . The aqueous formulation of  claim 1 , wherein said polyorganosiloxane a2) containing hydroxyl groups is a compound of the general formula (VI) 
     
       
         
         
             
             
         
       
     
     wherein
 m is an integer from 5 to 15; and 
 y is an integer from 2 to 4. 
 
   
   
       14 . The aqueous formulation of  claim 11 , wherein said polyorganosiloxane a2) having the general formula (I) has a number-average molecular weight in the range of from 200 to 3,000 g/mol and an average OH functionality of at least 1.8. 
   
   
       15 . The aqueous formulation of  claim 11 , wherein said polyorganosiloxane a2) having the general formula (I) has a number-average molecular weight in the range of from 250 to 2,250 g/mol. 
   
   
       16 . The aqueous formulation of  claim 1 , wherein said inorganic particles B) are selected from the group consisting of inorganic oxides, mixed oxides, carbides, borides and nitrides of elements of main group II to IV and/or elements of subgroup I to VIII of the periodic table, including the lanthanides. 
   
   
       17 . The aqueous formulation of  claim 1 , wherein said inorganic particles B) are inorganic nanoparticles in a colloidally disperse form in organic solvents or in water. 
   
   
       18 . The aqueous formulation of  claim 1 , wherein said inorganic particles B) are inorganic particles in the form of aqueous formulations. 
   
   
       19 . The aqueous formulation of  claim 1 , wherein said inorganic particles B) are surface-modified inorganic nanoparticles. 
   
   
       20 . An aqueous coating composition comprising the aqueous formulation of  claim 1  and at least one crosslinking agent D). 
   
   
       21 . An aqueous two-component coating composition comprising the aqueous formulation of  claim 1  and a polyisocyanate. 
   
   
       22 . A clear lacquer comprising the aqueous formulation of  claim 1 .