Thermally and structurally stable noncombustible paper

Abstract

The present invention is drawn to a thermally and structurally stable, noncombustible paper, comprising a dominant amount of aluminosilicate refractory fibers and from 0.2% to 4% by weight of a polymeric binder. The refractory fibers can be substantially from 1 micron to 35 microns in width and from 1 cm to 15 cm in length, though other functional dimensions can be used. Optionally, from 0.1% to 5% by weight of viscose fibers and/or from 0.2% to 5% by weight of silicic acid aquagel can also be present. The papers of the present invention are mat-type papers that can be structurally stable at very high temperatures up to about 1400° C. or more.

What is claimed is:  
     
         1 . A noncombustible fibrous paper comprising: 
 (a) a dominant amount by weight of aluminosilicate refractory fibers, said fibers being substantially from 1 micron to 35 microns in width and from 1 cm to 15 cm in length; and    (b) from 0.2% to 4% by weight of a polymeric binder distributed throughout the paper,    said paper being structurally stable when in direct contact with a flame at a very high temperature up to about 1400° C.    
     
     
         2 . A noncombustible paper as in claim I wherein the very high temperature is from about 1000° C. to 1400° C.  
     
     
         3 . A noncombustible paper as in  claim 1  wherein the dominant amount is from 90 to 99.8% by weight.  
     
     
         4 . A noncombustible paper as in  claim 1  wherein the dominant amount is from 70% to 99.8% by weight and further comprising an effective amount of a second noncombustible material.  
     
     
         5 . A noncombustible paper as in  claim 1  wherein the polymeric binder is a vinyl acetate/ethylene copolymer emulsion.  
     
     
         6 . A noncombustible paper as in  claim 1  further comprising from 0.1% to 5% by weight of a textile filler.  
     
     
         7 . A noncombustible paper as in  claim 6  wherein the textile filler is a viscose fiber.  
     
     
         8 . A noncombustible paper as in  claim 1  further comprising an effective amount of a second binder.  
     
     
         9 . A noncombustible paper as in  claim 8  wherein the second binder is applied as a coating.  
     
     
         10 . A noncombustible paper as in  claim 8  wherein the coating is a copolymer emulsion.  
     
     
         11 . A noncombustible paper as in  claim 10  wherein the copolymer emulsion is a vinyl acetate/ethylene copolymer emulsion.  
     
     
         12 . A noncombustible paper as in  claim 1  further comprising from 0.2% to 5% by weight of silicic acid aquagel.  
     
     
         13 . A noncombustible paper as in  claim 12  wherein the silicic acid aquagel is dehydrated during processing of the paper and becomes an amorphous adhesive.  
     
     
         14 . A noncombustible paper as in  claim 1  wherein said paper is structurally stable when exposed to a continuous flame having temperatures of at least 1200° C. without substantial disintegration.  
     
     
         15 . A noncombustible paper as in  claim 1  wherein the aluminosilicate refractory fibers are comprised of from 30% to 70% silica by weight and from 70% to 30% by weight alumina.  
     
     
         16 . A noncombustible paper as in  claim 15  wherein the silica and the alumina are present in substantially equal proportions by weight.  
     
     
         17 . A noncombustible paper as in  claim 1  further comprising from 0.1% to 3% of one or more mineral oxide by weight.  
     
     
         18 . A noncombustible paper as in  claim 1  wherein the paper has a density from about 180 to 240 kg/M 3 .  
     
     
         19 . A noncombustible paper as in  claim 1  wherein the paper is from 0.3 mm to 3.0 mm in thickness.  
     
     
         20 . A method of making a noncombustible paper comprising: 
 (a) pulping aluminosilicate refractory fibers;    (b) adding an effective amount of a polymeric binder forming a continuous pulp;    (c) pressing the continuous pulp; and    (d) dehydrating the continuous pulp.    such that a mat paper is formed that is structurally stable at a very high temperature when in direct contact with a flame.    
     
     
         21 . A method as in  claim 20  wherein the very high temperature is from about 1000° C. to 1400° C.  
     
     
         22 . A method as in  claim 20  wherein the polymeric binder is a vinyl acetate/ethylene copolymer emulsion.  
     
     
         23 . A method as in  claim 20  comprising the step of coating the paper with a polymeric coating.  
     
     
         24 . A method as in  claim 20  wherein the polymer coating is a vinyl acetate/ethylene copolymer emulsion.  
     
     
         25 . A method as in  claim 20  further comprising the step of adding an effective amount of a textile filler.  
     
     
         26 . A method as in  claim 25  wherein the textile filler is a viscose fiber.  
     
     
         27 . A method as in  claim 20  further comprising the step of adding an effective amount of silicic acid aquagel.  
     
     
         28 . A method as in  claim 20  further comprising the step of cleaning the aluminosilicate refractory fibers after pulping.  
     
     
         29 . A method as in  claim 20  further comprising the preliminary step selecting low granule-content aluminosilicate fibers.  
     
     
         30 . A method as in  claim 20  wherein the aluminosilicate refractory fibers are comprised of from 30% to 70% silica by weight and from 70% to 30% by weight alumina.  
     
     
         31 . A method as in  claim 20  further comprising the preliminary step of extruding aluminosilicate to form textile fibers having a predetermined dimension.  
     
     
         32 . A method as in  claim 31  wherein the predetermined dimension is from 1 micron to 35 microns in width and from 1 cm to 15 cm in length.