Bituminous membranes with biodegradable binder

Abstract

A nonwoven carrier for bituminous membranes, wherein the nonwoven includes organic polymer fibers and is consolidated with an aqueous binder, wherein the binder includes starch and polyvinyl alcohol, which includes up to 5 mol. % of other monomer units, wherein the binder does not include a crosslinker, and the binder does not include a filler.

1 . A nonwoven carrier for bituminous membranes, wherein the nonwoven comprises organic polymer fibers and is consolidated with an aqueous binder, wherein the binder comprises:
 starch, and   polyvinyl alcohol, which comprises up to 5 mol. % of other monomer units, wherein:   the binder does not comprise a crosslinker, and   the binder does not comprise a filler.   
     
     
         2 . The nonwoven carrier of  claim 1 , wherein the starch is a physically and/or chemically modified starch from natural origin. 
     
     
         3 . The nonwoven carrier of  claim 1  wherein the starch is partly hydrolysed. 
     
     
         4 . The nonwoven carrier of  claim 1 , wherein the binder comprises less than 2% additives based on total dry weight. 
     
     
         5 . The nonwoven carrier of  claim 1 , wherein the average size of starch particles in an aqueous binder dispersion is at least 0.1 μm, as determined by dynamic light scattering (DLS), and/or wherein the viscosity of the starch is at least 150 mPa*s, determined according to ISO 2555 at a concentration of 25 wt. % at 23° C. 
     
     
         6 . The nonwoven carrier of  claim 1 , wherein the starch is insoluble in water at 23° C. and/or not pre-gelatinized, and/or wherein the starch comprises 10% to 50% amylose (dry weight, of total of amylose and amylopectin). 
     
     
         7 . The nonwoven carrier of  claim 1 , wherein the starch and polyvinyl alcohol are not substantially crosslinked, and/or wherein the viscosity of the polyvinyl alcohol is at least 25 mPa*s, determined according to DIN EN ISO 2555 at a concentration of 4 wt. % at 23° C. 
     
     
         8 . The nonwoven carrier of  claim 1 , wherein the binder comprises 5 to 95 wt. % starch, 5 to 95 wt. % polyvinyl alcohol and 0 to 15 wt. % additives, wherein all percentages refer to dry weight and the total of all percentages is 100 wt. %. 
     
     
         9 . The nonwoven carrier of  claim 1 , wherein the binder does not comprise structural polymers different from starch and polyvinyl alcohol, and/or wherein the binder does not comprise an additive, which comprises hydroxyl groups. 
     
     
         10 . The nonwoven carrier of  claim 1 , wherein the nonwoven consists of organic polymer fibers, preferably polyester fibers, and/or wherein the nonwoven comprises a reinforcement. 
     
     
         11 . A method for producing the nonwoven carrier of  claim 1 , comprising the steps of
 (a) providing a nonwoven,   (b) impregnating the nonwoven with an aqueous binder comprising starch and polyvinyl alcohol, wherein the binder does not comprise a crosslinker, and   (c) drying and solidifying the binder to obtain the nonwoven carrier.   
     
     
         12 . A method for producing bituminous membranes, comprising using the nonwoven carrier of  claim 1  as a substrate for producing the bituminous membranes. 
     
     
         13 . A method for producing a bituminous membrane, comprising the steps of:
 (A) providing the nonwoven carrier of  claim 1 , and   (B) impregnating the nonwoven carrier with bitumen.   
     
     
         14 . A bituminous membrane, comprising the nonwoven carrier of  claim 1 . 
     
     
         15 . A roof, building material or building comprising a bituminous membrane according to  claim 14 .