Waterproofing membrane

A waterproofing membrane in the form of a sheet-like laminate comprising a carrier sheet, a pressure sensitive adhesive layer on one surface of the carrier sheet, a protective coating layer on the adhesive layer, and a releasable bonding layer on the protective coating layer, wherein the releasable bonding layer comprises nanoscale silica and a binder, wherein the nanoscale silica is present in an amount of 30% to 70% by volume of the silica and binder and the nanoscale silica has a particle size of 5 nm to 30 nm, and wherein the releasable bonding layer has a coating weight of 1 g/m2 to 15 g/m2 and said binder comprises a water soluble polymer, an alkali soluble polymer, or a homopolymer or copolymer of polyvinyl acetate selected from the group consisting of polyvinyl alcohol (PVOH), polyethylene oxide (PEO), water soluble cellulosic polymers including hydroxypropyl methyl cellulose and hydroxyethyl cellulose, hydrolyzed maleic anhydride polymers and copolymers, polyvinylpyrrolidone, sulfonated polystyrene, polysulfoethyl acrylate, poly(2-hydroxyethylacrylate), polyacrylamide, poly(acrylic acid) and alkali metal salts thereof, natural or synthetically modified polysaccharides, proteins, alginates, xanthan gums, and guar gums, styrene maleic anhydride copolymers, copolymers of acrylic acid and styrene and/or alpha-methyl styrene, hydroxypropyl methylcellulose acetate succinate, copolymers of methacrylic acid and methylmethacrylate, acrylic acid-ethyl acrylate-methyl methacrylate copolymer, a copolymer of ethyl acrylate, methylmethacrylate, and acrylic acid, rosin acid, and homopolymers or copolymers of polyvinyl acetate;

• and
• said protective coating layer having a penetration ≦20 dmm (ASTM D5), and a reflectivity ≧55%, measured by a reflectometer perpendicular to a surface illuminated at a 45° angle, and wherein said protective coating layer comprises an acrylic or methacrylic polymer having at least 50 wt % acrylic or methacrylic monomer units and a Tg of −40° C. to 0° C., a filler and a white pigment, wherein the pigment volume concentration of the filler plus white pigment is 55% to 90% by volume;
• and said protecting coating layer has a textured surface.

A waterproofing membrane in the form of a sheet-like laminate, comprising:

• a carrier sheet having first and second opposing surfaces;
• a pressure sensitive adhesive layer having first and second opposing surfaces, one of which is adhered on one surface of the carrier sheet;
• and
• a protective coating layer having first and second opposing surfaces, one of which is adhered on the surface of the pressure sensitive adhesive layer opposite the surface adhered to the carrier sheet, the protective coating layer having a penetration ≦20 dmm (ASTM D5), and a reflectivity ≧55%, measured by a reflectometer perpendicular to a surface illuminated at a 45° angle, and the protective coating layer comprising an acrylic or methacrylic polymer having at least 50 wt % acrylic or methacrylic monomer units and a Tg of −40° C. to 0° C., an inorganic filler and a white pigment, wherein the pigment volume concentration of the inorganic filler plus white pigment is 55% to 90% by volume, the inorganic filler being selected from the group consisting of calcium carbonate, silica, diatomaceous earth, barites, magnesium silicates, talc, clay and alumina trihydrate, and wherein the white pigment is selected from the group consisting of titanium dioxide, antimony oxide, zinc sulfide, and zinc oxide;
• and
• a releasable bonding layer having first and second opposed surfaces, one of which is adhered on the surface of the protective coating layer opposite the surface adhered to the pressure sensitive adhesive layer, the releasable bonding layer having a coating weight of 1 g/m2 to 15 g/m2 and comprising a polymer selected from the group consisting of polyvinyl alcohol (PVOH), polyethylene oxide (PEO), water soluble cellulosic polymers including hydroxypropyl methyl cellulose and hydroxyethyl cellulose, hydrolyzed maleic anhydride polymers and copolymers, polyvinylpyrrolidone, sulfonated polystyrene, polysulfoethyl acrylate, poly(2-hydroxyethylacrylate), polyacrylamide, poly(acrylic acid) and alkali metal salts thereof, natural or synthetically modified polysaccharides, proteins, alginates, xanthan gums, and guar gums, styrene maleic anhydride copolymers, copolymers of acrylic acid and styrene and/or alpha-methyl styrene, hydroxypropyl methylcellulose acetate succinate, copolymers of methacrylic acid and methylmethacrylate, acrylic acid-ethyl acrylate-methyl methacrylate copolymer, a copolymer of ethyl acrylate, methylmethacrylate, and acrylic acid, rosin acid, and homopolymers or copolymers of polyvinyl acetate.