Compositions and methods for providing increased strength in ceiling, flooring, and building products

Abstract

The present invention is directed to products, such as paper and paperboard products, comprising a substrate containing cellulose and top ply comprising microfibrillated cellulose and inorganic particulate, to methods of making such paper and paperboard products, and associated uses of such paper and paperboard products. The microfibrillated cellulose and inorganic particulate material are applied at the stage when the wet substrate is in the process of being formed on the wire of a papermaking machine, thereby avoiding the additional cost of more extensive equipment and machinery as well as in separate drying of a coating. The microfibrillated cellulose facilitates the application of inorganic particulate onto the surface of a wet paper or paperboard substrate when applied thusly, by trapping the inorganic particulate on the surface of the substrate and by giving the composite sufficient strength and a suitable pore structure to make it suitable for printing and other end-use demands.

What is claimed is: 
     
         1 .- 20 . (canceled) 
     
     
         21 . A construction product comprising a composition of microfibrillated cellulose and one or more inorganic particulate material. 
     
     
         22 . The construction product of  claim 21 , wherein the construction product is a ceiling tile. 
     
     
         23 . The ceiling tile of  claim 22 , wherein the ceiling tile further comprises mineral wool or perlite, or both mineral wool and perlite. 
     
     
         24 . The ceiling tile of  claim 22 , wherein the ceiling tile further comprises wood pulp or paper pulp and, optionally, starch and/or a latex binding agent. 
     
     
         25 . The ceiling tile of  claim 23 , wherein the ceiling tile further comprises wood pulp or paper pulp and, optionally, starch and/or a latex binding agent. 
     
     
         26 . The ceiling tile of  claim 22 , wherein the ceiling tile comprises up to about 50% by weight of the microfibrillated cellulose, based on the total dry weight of the ceiling tile. 
     
     
         27 . The ceiling tile of  claim 23 , wherein the ceiling tile comprises up to about 50% by weight of the microfibrillated cellulose, based on the total dry weight of the ceiling tile. 
     
     
         28 . The ceiling tile of  claim 26 , wherein the ceiling tile comprises up to about 25% by weight of the microfibrillated cellulose composition, based on the total dry weight of the ceiling tile. 
     
     
         29 . The ceiling tile of  claim 27 , wherein the ceiling tile comprises up to about 25% by weight of the microfibrillated cellulose composition, based on the total dry weight of the ceiling tile. 
     
     
         30 . The ceiling tile of any of  claim 28 , wherein the ceiling tile comprises up to about 10% by weight of the microfibrillated cellulose composition, based on the total dry weight of the ceiling tile. 
     
     
         31 . The ceiling tile of any of  claim 29 , wherein the ceiling tile comprises up to about 10% by weight of the microfibrillated cellulose composition, based on the total dry weight of the ceiling tile. 
     
     
         32 . The ceiling tile according to  claim 22 , wherein the ceiling tile comprises up to about 80% by weight perlite or mineral wool, or both perlite and mineral wool, based on the total dry weight of the ceiling tile. 
     
     
         33 . The ceiling tile according to  claim 23 , wherein the ceiling tile comprises up to about 80% by weight perlite or mineral wool, or both perlite and mineral wool, based on the total dry weight of the ceiling tile. 
     
     
         34 . The ceiling tile according to  claim 22 , wherein the ceiling tile comprises up to about 25% by weight wood pulp or paper pulp, based on the total dry weight of the ceiling tile. 
     
     
         35 . The ceiling tile according to  claim 32 , wherein the ceiling tile comprises up to about 10% by weight wood pulp or paper pulp, based on the total dry weight of the ceiling tile. 
     
     
         36 . The ceiling tile according to  claim 23 , wherein the ceiling tile comprises up to about 25% by weight wood pulp or paper pulp, based on the total dry weight of the ceiling tile. 
     
     
         37 . The ceiling tile according to  claim 34 , wherein the ceiling tile comprises up to about 10% by weight wood pulp or paper pulp, based on the total dry weight of the ceiling tile. 
     
     
         38 . The ceiling tile according to  claim 22 , wherein the ceiling tile has a flexural strength which is improved compared to a ceiling tile which does not comprise microfibrillated cellulose. 
     
     
         39 . The ceiling tile according to  claim 36 , wherein the ceiling tile has a flexural strength of at least about 400 kPa. 
     
     
         40 . The ceiling tile according to  claim 31 , wherein the ceiling tile further comprises: (ii) up to about 20% by weight of microfibrillated cellulose, based on the total dry weight of the ceiling tile, for example, from about 10% by weight to about 20% by weight, or from about 1% by weight to about 10% by weight of the microfibrillated cellulose composition; and/or (i) up to 20% by weight of wood pulp or paper pulp, based on the total dry weight of the ceiling tile, for example, from about 5% by weight to about 20% by weight wood pulp, for example, from about 5% by weight to about 15% by weight wood pulp, or from about 8% by weight to about 12% by weight pulp. 
     
     
         41 . The ceiling tile according to  claim 22 , wherein the microfibrillated cellulose composition comprises microfibrillated cellulose and inorganic particulate material in a weight ratio of from about 5:1 to about 1:166. 
     
     
         42 . The ceiling tile according to  claim 23 , wherein the microfibrillated cellulose composition comprises microfibrillated cellulose and inorganic particulate material in a weight ratio of from about 5:1 to about 1:166. 
     
     
         43 . The ceiling tile according to  claim 22 , wherein the inorganic particulate, when present, is or comprises calcium carbonate or kaolin. 
     
     
         44 . The ceiling tile according to  claim 23 , wherein the inorganic particulate, when present, is or comprises calcium carbonate or kaolin. 
     
     
         45 . The ceiling tile according to  claim 22 , wherein the microfibrillated cellulose has a fibre steepness of from about 20 to about 50. 
     
     
         46 . The ceiling tile according to  claim 23 , wherein the microfibrillated cellulose has a fibre steepness of from about 20 to about 50. 
     
     
         47 . A method for making a construction product according to  claim 21 , comprising combining the microfibrillated composition with other component(s) of the construction product and forming the construction product therefrom. 
     
     
         48 . A method for making a ceiling tile according to  claim 22 , comprising combining the microfibrillated cellulose composition with other component(s) of the ceiling product and forming a ceiling tile therefrom.