Roofing membrane having a controllable color change

1 . A roofing membrane comprising a polymeric waterproofing layer having upper and lower major surfaces and an electronic ink display covering at least a portion of the upper major surface of the polymeric waterproofing layer, wherein the polymeric waterproofing layer exhibits a water resistance measured according to EN 1928 B standard of 0.6 bar for 24 hours and wherein the electronic ink display is selected from electrophoretic, electrowetting, and electrofluidic displays.

2 . The roofing membrane according to claim 1 , wherein the electronic ink display covers at least 15% of a total area of the upper major surface of the polymeric waterproofing layer.

3 . The roofing membrane according to claim 1 , wherein a second surface of electric ink display has been thermally, mechanically, or adhesively adhered to at least a portion of the upper major surface of the polymeric waterproofing layer.

4 . The roofing membrane according to claim 1 , wherein the electronic ink display is an electrophoretic display comprising:

a first surface on a viewing side and a second surface of a non-viewing side

a first light-transmissive electrode layer at the viewing side,

a backplane comprising a second electrode layer, and

an electrophoretic material layer comprising an electrophoretic medium sandwiched between the first light-transmissive electrode layer and the backplane.

5 . The roofing membrane according to claim 4 , wherein the first surface of the electrophoretic display faces away from the upper major surface of the polymeric waterproofing layer.

6 . The roofing membrane according to claim 4 , wherein the first light-transmissive electrode layer is a metal layer or a conductive polymer layer.

7 . The roofing membrane according to claim 4 , wherein the second electrode layer comprises an array of pixel electrodes.

8 . The roofing membrane according to claim 4 , wherein the electrophoretic medium is compartmented in display cells.

9 . The roofing membrane according to claim 4 , wherein the electrophoretic display further comprises a protective polymeric sheet covering at least a portion of an upper surface of the first light-transmissive electrode layer.

10 . The roofing membrane according to claim 4 , wherein the electrophoretic display further comprises a conductive edge seal, which electrically connects the first light-transmissive electrode layer to the second electrode layer.

11 . The roofing membrane according to claim 1 , wherein the polymeric waterproofing layer comprises at least one polymer selected from polyolefins, halogenated polyolefins, polyvinylchloride, rubbers, and ketone ethylene esters.

12 . The roofing membrane according to claim 1 further comprising a reinforcing layer at least partially embedded into the polymeric waterproofing layer or adhered to least a portion of the lower major surface of the polymeric waterproofing layer.

13 . The membrane roofing according to claim 12 wherein the reinforcing layer is a layer of fiber material.

14 . The roofing membrane according to claim 1 , wherein the polymeric waterproofing layer has a thickness of 0.1-3.5 mm and/or a width of 0.5-5 m.

15 . A method for producing a roofing membrane according to claim 1 , the method comprising steps of:

I) providing a polymeric waterproofing layer having upper and lower major surfaces and

II) applying an electronic ink display on the upper major surface of the polymeric waterproofing layer, wherein the electronic ink display is selected from electrophoretic, electrowetting and electrofluidic displays.

16 . The method according to claim 15 , wherein step II) is conducted by using thermal or adhesive lamination, mechanical attachment, printing, or coating techniques.

17 . A method for covering a roof substrate, the method comprising steps of:

I. applying two or more sheets of the roofing membrane according to claim 1 on surface of the substrate to be covered,

II. overlapping adjacent sheets of the roofing membrane along length and/or width of the sheets, and

III. bonding opposing surfaces of overlapped portions of the adjacent sheets to each other to provide acceptable seam strength by using heat-welding or by adhesive bonding.