Binder systems derived from amorphous silica and bases

Abstract

The present invention relates to compositions comprising the reaction product of amorphous silica or ultra-fine silica and one or more bases. The present invention also relates to materials and method involving the use of such products. In particular, the present invention i.a. relates to new mineral wool products, e.g. products comprising man-made vitreous fibres (such as glass fibres, slag fibres, stone fibres and rock fibres) or perlite, having included therein a binder component which comprises amorphous silica and alkali metal organosiliconates, e.g. potassium methyl siliconate. An important feature of such products is the preparation of the binder systems under vigorous mixing. Such products provide good fire, heat and sound insulating properties. The present invention also provides to a method for removing odorous substances from a gas where materials prepared from ultra-fine silica, water, and one or more components enabling porosity-conferring binding of the material, e.g. a base or bases. Furthermore, the invention provides methods for thixotroping bitumen.

1 . A mineral fibre/particle product comprising mineral fibres and/or mineral particles and a binder system, said binder system being derived from a mixture comprising amorphous silica and one or more bases, and optionally one or more additives.  
     
     
         2 . A product according to  claim 1 , wherein the binder system is derived from a mixture comprising amorphous silica, at least one of 
 (a) an alkali metal organosiliconate and    (b) a base.    
     
     
         3 . A mineral product according to  claim 2 , wherein the binder system is derived from an alkali metal organosiliconate.  
     
     
         4 . A mineral product according to  claim 2 , wherein the base is selected from alkali or alkaline earth metal hydroxides, alkali or alkaline earth metal silicates, aluminium silicates, iron(II) and iron(III) silicates and mixtures thereof, alkali or alkaline earth metal pyrosilicates, aluminium pyrosilicates, iron(II) and iron(III) pyrosilicates and mixtures thereof, alkali or alkaline earth metal carbonates, alkali or alkaline earth metal bicarbonates, alkali or alkaline earth metal phosphates, alkali or alkaline earth metal pyrophosphates, ammonia, organic amines, and cements, and combinations thereof.  
     
     
         5 . A mineral product according to  claim 4 , wherein the base is selected from alkali metal hydroxides, alkaline earth metal hydroxides and cements, preferably selected from sodium hydroxide, potassium hydroxide and calcium hydroxide.  
     
     
         6 . A method for preparing a mineral fibre/particle product comprising mineral fibres and/or mineral particles and a binder system, said binder system being derived from an aqueous mixture of amorphous silica, one or more bases, and optionally additives, the method comprising the step of: 
 preparing a binder system by vigorously mixing an aqueous slurry of the amorphous silica, the one or more bases, and the optional additives,    applying the binder system to the mineral fibres and/or mineral particles, and    drying and curing the binder so as to obtain the mineral fibre/particle product.    
     
     
         7 . A method according to  claim 6 , wherein the binder system is derived from an aqueous mixture of amorphous silica, at least one of (a) an alkali metal organosiliconate and (b) a base, and optionally additives, and the preparation of the binder system is performed by mixing an aqueous slurry of the amorphous silica, with the at least one of (a) an alkali metal organosiliconate and (b) a base, and the optional additives.  
     
     
         8 . A method according to any of the claims  6 , wherein the pH of the binder system is in the range of 7.5-11.0 upon application to the mineral fibres and/or mineral particles.  
     
     
         9 . An water-based binder system comprising the reaction product of amorphous silica and one or more bases.  
     
     
         10 . A binder system according to  claim 9 , wherein the one or more bases is at least one of (a) an alkali metal organosiliconate and (b) a base, and which optionally comprises one or more additives.  
     
     
         11 . A binder system according to  claim 9 , which has a pH in the range of 7.5-11.0.  
     
     
         12 . A binder system according  claim 9 , wherein the base is selected from alkali or alkaline earth metal hydroxides, alkali or alkaline earth metal silicates, aluminium silicates, iron(II) and iron(III) silicates and mixtures thereof, alkali or alkaline earth metal pyrosilicates, aluminium pyrosilicates, iron(II) and iron(III) pyrosilicates and mixtures thereof, alkali or alkaline earth metal carbonates, alkali or alkaline earth metal bicarbonates, alkali or alkaline earth metal phosphates, alkali or alkaline earth metal pyrophosphates, ammonia, organic amines, and cements, and combinations thereof.  
     
     
         13 . A binder system according to  claim 9 , wherein the base is selected from alkali metal hydroxides, alkaline earth metal hydroxides and cements, preferably selected from sodium hydroxide, potassium hydroxide and calcium hydroxide.  
     
     
         14 . A method for preparing a binder system derived from a mixture comprising amorphous silica, one or more bases, and optionally additives, the method comprising vigorously mixing an aqueous slurry of the amorphous silica with the one or more bases, and the optional additives.  
     
     
         15 . A mineral fibre/particle product according to  claim 1  comprising mineral fibres and/or mineral particle and a binder system, said binder system being derived from a mixture comprising amorphous silica and potassium hydroxide, and optionally one or more additives, the stoichiometric ratio of amorphous silica to potassium hydroxide being 1:<1.  
     
     
         16 . A method according to  claim 6 , wherein the base is selected from alkali metal hydroxides, alkaline earth metal hydroxides and cements, preferably selected from sodium hydroxide, potassium hydroxide and calcium hydroxide.  
     
     
         16 . A method according to  claim 6  for preparing a mineral fibre/particle product comprising mineral fibres and/or mineral particle and a binder system, said binder system being derived from a mixture comprising amorphous silica and potassium hydroxide, and optionally additives, the method comprising the steps of: 
 preparing a binder system by mixing an aqueous slurry of the amorphous silica with potassium hydroxide and the optional additives, the stoichiometric ratio of amorphous silica to potassium hydroxide being 1:<1,    applying the binder system having a pH of 7.5-11.0 to the mineral fibres and/or mineral particles, and    drying and curing the binder so as to obtain the mineral fibre/particle product.