Water proofing membrane, and a method for making a water proofing membrane

Abstract

The invention relates to a waterproofing membrane ( 1 ) comprising a structure incorporating a fiber layer ( 10 ) and carrying a bituminous mass ( 15 ) on one side, the other side carrying a layer ( 20 ) of a first substance comprising between 10% and 40% by dry weight of an acrylic polymer mixed with between 4% and 40%, preferably between 20% and 40%, by dry weight of titanium dioxide and at least 1% by dry weight of a transparent or translucent hydrophobic material, said layer ( 20 ) defining a surface (S) of said membrane ( 1 ).

1 . A waterproofing membrane comprising a structure incorporating a fiber layer and carrying a bituminous mass on one side, the other side carrying a layer of a first substance comprising between 10% and 40% by dry weight of an acrylic polymer, mixed with between 4% and 40% by dry weight of titanium dioxide and at least 1% by dry weight of a transparent or translucent hydrophobic material, said layer defining a surface of said membrane. 
     
     
         2 . The waterproofing membrane of  claim 1 , wherein said layer of said first substance comprises between 30 g/m 2  and 120 g/m 2  of said acrylic polymer, between 12 g/m 2  and 120 g/m 2  of said titanium dioxide and at least 3 g/m 2  of said hydrophobic material. 
     
     
         3 . The waterproofing membrane of  claim 1 , wherein said hydrophobic material is selected such that a drop of liquid water in contact with said surface of the membrane has a contact angle θ c , measured in accordance with contact angle meter (name of test) greater than 90°, such as in the order of 93°-100°. 
     
     
         4 . The waterproofing membrane according to  claim 1 , wherein said first substance comprises between 1% and 5% by dry weight of a polyurethane polymer. 
     
     
         5 . The waterproofing membrane according to  claim 4 , wherein said layer of said first substance comprises between 3 g/m 2  and 15 g/m 2  of said polyurethane polymer. 
     
     
         6 . The water-proofing substance according to  claim 1 , wherein said hydrophobic material is chosen from the group consisting of carnauba, polyethylene, paraffin wax emulsions, polysiloxanes emulsions and fluorosurfactants. 
     
     
         7 . The water proofing-membrane according to  claim 1 , wherein said first substance comprises between 10% and 25% by dry weight of said acrylic polymer mixed with between 20% and 30% by dry weight of titanium dioxide. 
     
     
         8 . The water proofing-membrane according to  claim 7 , wherein said layer of said first substance comprises between 30 g/m 2  and 75 g/m 2  of said acrylic polymer and between 60 g/m 2  and 90 g/m 2  of said titanium dioxide. 
     
     
         9 . The waterproofing membrane according to  claim 1 , wherein said first substance comprises between 18% and 23% by dry weight of said acrylic polymer and between 25% and 30% by dry weight of said titanium dioxide. 
     
     
         10 . The water proofing-membrane according to  claim 9 , wherein said layer of said first substance comprises between 50g/m 2  and 70 g/m 2  of said acrylic polymer and between 75 g/m 2  and 90 g/m 2  of said titanium dioxide. 
     
     
         11 . The waterproofing membrane according to  claim 1 , wherein said first substance comprises between 1% and 5% by dry weight of said hydrophobic material. 
     
     
         12 . The water proofing-membrane according to  claim 11 , wherein said layer of said first substance comprises between 3 g/m 2  and 15 g/m 2  of said hydrophobic material. 
     
     
         13 . The waterproofing membrane according to  claim 1 , wherein said first substance further comprises between 30% and 50% by dry weight of mineral filler being a mixture of talc, calcium carbonate and aluminium hydroxide. 
     
     
         14 . The water proofing-membrane according to  claim 13 , wherein said layer of said first substance comprises between 90 g/m 2  and 150 g/m 2  of said mineral filler. 
     
     
         15 . The waterproofing membrane according to  claim 1 , wherein said bituminous mass comprises an atactic polypropylene, an atactic poly alpha olefin or a thermoplastic polyolefin. 
     
     
         16 . The waterproofing membrane according to  claim 1 , wherein said bituminous mass comprises styrene butadiene styrene. 
     
     
         17 . The waterproofing membrane of  claim 16 , wherein said styrene butadiene styrene comprises at least approximately 8% of a thermoplastic elastomer. 
     
     
         18 . The waterproofing membrane according to  claim 1 , including a plastic foil or other protective layer on said bituminous mass. 
     
     
         19 . A method of making a water proofing membrane with a layer of a first substance according to  claim 1 , including the steps of i) preparing said first substance by mixing said acrylic polymer as a suspension, dispersion or solution with said titanium dioxide and with said hydrophobic material in liquid form, such that said acrylic polymer and said hydrophobic material form a matrix for said titanium dioxide, ii) applying said first substance as a layer onto a first side of said fiber layer, and iii) applying said bituminous substance onto a second side of said fiber layer. 
     
     
         20 . The method of  claim 19 , wherein said acrylic polymer, said titanium dioxide and said hydrophobic material are added separately to a mixer under agitation, preferably adding the hydrophobic material lastly.