SEALING MEMBRANE FOR A ROOF

Abstract

The invention relates to a sealing membrane for a roof, comprising: an upper layer made from a polymer material, a lower sealing layer arranged to cover the roof, and a reinforcement disposed between the upper layer and the lower layer, characterised in that the polymer material is bi-oriented.

Claims

1. Waterproofing membrane for a roof comprising: an upper layer made from a polymer material being arranged to reflect UV rays, a lower waterproofing layer being arranged to cover a roof, and a reinforcement disposed between said upper layer and said lower layer, characterised in that said polymer material is bi-oriented.

2. Membrane according to claim 1, wherein said bi-oriented polymer material is selected from the group constituted of polypropylene, polyester and the mixtures thereof.

3. Membrane according to claim 1, wherein said upper layer made from a bi-oriented polymer material is a bi-oriented polyester multilayer.

4. Membrane according to claim 1, wherein said polyester is selected from the group constituted of poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN) and poly(butylene terephthalate) (PBT) and the mixtures thereof.

5. Membrane according to claim 3, wherein said bi-oriented polyester multilayer comprises a pigment selected from the group constituted of titanium dioxide (TiO.sub.2), barium sulphate, calcium carbonate and the mixtures thereof.

6. Membrane according to claim 3, wherein said bi-oriented polyester multilayer comprises a first outer layer, a second outer layer, connected to each other by a central layer.

7. Membrane according to claim 6, wherein said central layer comprises TiO.sub.2 in a quantity of between 0.1-40% by weight, preferably between 0.5-30% by weight, more preferably between 0.6-0.75% by weight, more preferably still between 0.65-0.75% by weight, with respect to the total weight of the central layer.

8. Membrane according to claim 6, wherein said first outer layer and/or said second outer layer comprising TiO.sub.2 in a quantity less than 5% by weight, preferably less than 4% by weight, more preferably between 0.01-3% by weight, with respect to the total weight of said first outer layer and/or said second outer layer.

9. Membrane according to claim 6, wherein said first outer layer and/or said second outer layer comprises PET.

10. Membrane according to claim 4, wherein said PET have an average molecular weight by number within the range going from 18,500-40,000, preferably ranging from 19,000-35,000, more preferably ranging from 20,000-30,000.

11. Membrane according to claim 4, wherein said PET has carboxyl groups in a quantity less than or equal to 30 eq/T, preferably less than or equal to 25 eq/T, more preferably less than or equal to 21 eq/T, more preferably still less than or equal to 15 eq/T, advantageously between 5-15 eq/T.

12. Membrane according to claim 6, wherein said first outer layer and/or said second outer layer comprises a light stabilising agent to absorb UV rays and to reduce the effect of oxygen on the waterproofing membrane, said agent being selected from the group constituted of antioxidants, benzophenones, benzotriazoles, benzoxazinones, triazines, a triazine having 2 phenyl groups or 2 bi-phenyl groups and the mixtures thereof.

13. Membrane according to claim 1, wherein said upper layer made from a bi-oriented polymer material has a thickness of between 3 and 500 m, advantageously between 10 and 350 m; 50 and 200 m, preferably between 80 and 190 m, more preferably between 180 and 190 m.

14. Membrane according to claim 1, characterised in that said membrane is reflective.

15. Method for producing a waterproofing membrane according to claim 1, comprising the following steps: making a reinforcement having a first face and a second face available, applying a lower waterproofing layer on said first face of said reinforcement, applying a lower layer made from a bi-oriented polymer material on said second face of said reinforcement.

Description

EXAMPLE 1

[0099] An upper layer made from a bi-oriented polymer material is constituted of three polyester layers, respectively a first outer layer made from PET, a second outer layer made from PET, connected to each other by a central layer constituted of PET and TiO.sub.2, thus forming a bi-oriented polyester multilayer.

[0100] A polyester reinforcement comprises a first face and a second face which is equipped with the above-cited bi-oriented polyester multilayer. The first face of the reinforcement is impregnated with a bitumen-based lower layer, modified with APP. This enables to form a reflective membrane according to the present invention.

[0101] The type of reinforcement is not limited to that cited in the present example and can therefore advantageously be a glass mat or a fibre layer, preferably made from woven or non-woven polyester.

[0102] The bitumen-based lower layer is preferably made using a bitumen composition, modified with a polymer selected from the group constituted of atactic polypropylene (APP), poly(styrene-butadiene-styrene) (SBS), polystyrene-b-poly(ethylene butylene)-b-polystyrene (SEBS), polystyrene-b-poly(ethylene-propylene)-b-polystyrene (SEPS), dimethyl-gamma-butyrolactone acrylate (DBA), styrene-isoprene-styrene (SIS), ethylene vinyl acetate (EVA), isotactic polypropylene (IPP), syndiotactic polypropylene (SPP) and the mixtures thereof.

[0103] Alternatively, the lower waterproofing layer can be of a vegetable binder base.

EXAMPLE 2

[0104] An upper layer made from a bi-oriented polymer material is constituted of three polyester layers, respectively a first outer layer constituted of PET and TiO.sub.2, a second outer layer made from PET, connected to each other by a central layer constituted of PET and TiO.sub.2 thus forming a bi-oriented polyester multilayer.

[0105] A polyester reinforcement comprises a first face and a second face which is equipped with the above-cited bi-oriented polyester multilayer. The first face of the reinforcement is impregnated with a bitumen-based lower layer modified with APP. This enables to obtain a reflecting waterproofing membrane according to the present invention.

[0106] The type of reinforcement is not limited to that cited in the present example and can therefore advantageously be a glass mat or a fibre layer, preferably made from woven or non-woven polyester.

[0107] The bitumen-based lower layer is preferably made using a modified bitumen composition which could also be selected from the group of compounds cited in example 1.

[0108] Alternatively, the lower waterproofing layer can also be of a vegetable binder base.

EXAMPLE 3

[0109] An upper layer made from a bi-oriented polymer material is constituted of three polyester layers, respectively a first outer layer constituted of PET and TiO.sub.2, a second outer layer made from PET, connected to each other by a central layer constituted of PET and TiO.sub.2 thus forming a bi-oriented polyester multilayer.

[0110] A polyester reinforcement comprises a first face and a second face which is equipped with the above-cited bi-oriented polyester multilayer. The first face of the reinforcement is impregnated with a bitumen-based lower layer modified with APP. This enables to obtain a reflecting waterproofing membrane according to the present invention.

[0111] The type of reinforcement is not limited to that cited in the present example and can therefore advantageously be a glass mat or a fibre layer, preferably made from woven or non-woven polyester.

[0112] The bitumen-based lower layer is preferably made using a modified bitumen composition which could also be selected from the group of compounds cited in example 1.

EXAMPLE 4

[0113] An upper layer made from a bi-oriented polymer material is constituted of three polyester layers, respectively a first outer layer constituted of PET and TiO.sub.2, a second outer layer made from PET, connected to each other by a central layer constituted of PET and TiO.sub.2 thus forming a bi-oriented polyester multilayer.

[0114] A polyester reinforcement comprises a first face and a second face which is equipped with the above-cited bi-oriented polyester multilayer. The first face of the reinforcement is impregnated with a bitumen-based lower layer modified with APP. This enables to obtain a reflecting waterproofing membrane according to the present invention.

[0115] The type of reinforcement is not limited to that cited in the present example and can therefore advantageously be a glass mat or a fibre layer, preferably made from woven or non-woven polyester.

[0116] The bitumen-based lower layer is preferably made using a modified bitumen composition which could also be selected from the group of compounds cited in example 1.

[0117] Alternatively, the lower waterproofing layer can also be of a vegetable binder base.

EXAMPLE 5

[0118] A polyester reinforcement comprises a first face, which is impregnated with a bitumen-based lower layer modified with APP, and a second face which is equipped with at least one bi-oriented PET layer comprising a pigment, such as TiO.sub.2. This enables to obtain a reflective waterproofing membrane according to the present invention.

[0119] The type of reinforcement is not limited to that cited in the present example and can therefore advantageously be a glass mat or a fibre layer, preferably made from woven or non-woven polyester.

[0120] The bitumen-based lower layer is preferably made using a modified bitumen composition which could also be selected from the group of compounds cited in example 1.

[0121] Alternatively, the lower waterproofing layer can also be of a vegetable binder base.

COMPARATIVE EXAMPLE 1

[0122] A waterproofing membrane successively comprises a first PET and TiO.sub.2-based layer which is not oriented, a reinforcement and a second bitumen-based layer.

[0123] It has been observed that such a membrane has a lower lifespan that the membrane according to the invention, in particular that such as defined in example 5 above.

[0124] Indeed, the membrane according to this comparative example 1 has an early yellowing. Thus, the membrane is no longer capable of playing the waterproofing role thereof when it is placed on a roof, because of the exudation phenomenon. It is understood that the present invention is not, in any way, limited to the embodiments defined above, and that many modifications can be applied without moving away from the scope of the appended claims.