WO2014016855A1

WO2014016855A1 - Bituminous based waterproofing composite with solar reflective properties, manufacturing method thereof and multiple prefabricated layer for such composite

Info

Publication number: WO2014016855A1
Application number: PCT/IT2012/000230
Authority: WO
Inventors: Matthias Schuhbauer; Gerhard Fassbender; Antonio DE FERRARI; Ionna FASAKI; Anna GAKI; Maria TAXIARCHOU; Romy NAUMANN; Petra Franitza; Bernd Gulich; Yves SCHWARZMANN; Ioannis ARAMPATZIS; Erich BART; Rudolf HARTMUT FISCHER
Original assignee: D'appolonia S.P.A.; Amsp Cr-Association Of Small And Medium-Sized Enterprises And Crafts Of The Czech Republic; B+M Nottenkämper Gesellschaft für Bergbau und Mineralstoffe mbH & Co. KG; Cati Sanayici Ve Is Adamlari Dernegi; Georg Börner Chemisches Werk Für Dach- Und Bautenschutz Gmbh & Co; Internationale Foderation Des Dachdeckerhandwerks; Lega Regionale Toscana Cooperative E Mutue; Nanophos Anonimi Emporiki Etairia Anaptixis Kai Ypiresion; Ünar Yapi Ve Malzemeleri Tic. Ltd. Sti
Priority date: 2012-07-25
Filing date: 2012-07-25
Publication date: 2014-01-30

Abstract

The present invention relates to a multiple prefabricated layer (1) comprising a first reflective layer (2a), a reinforcing layer (3), said reinforcing layer having a first and a second side opposed each other, said first reflective layer (2a) being joined to said first side and further comprising a bitumen barrier (4) joined to said second side of said reinforcing layer (3); other objects of the invention are a composite comprising said multiple prefabricated layer and method of manufacturing said multiple prefabricated layer and said composite.

Description

Bituminous based waterproofing composite with solar reflective properties, manufacturing method thereof and multiple prefabricated layer for such composite

DESCRIPTION

The present invention relates to a waterproofing bituminous composite with reflective properties of the solar rays; in greater detail, the present invention comprises a multiple prefabricated top layer with reflective properties of the solar rays and a bituminous support with waterproofing capability.

Furthermore, the present invention relates to a process for the production of waterproofing bituminous composite with reflective properties.

Furthermore, the present invention relates to the laying of the waterproofing bituminous composite with reflective properties for covering roofs.

The development of the present invention is the result of the efforts made by a consortium of research entities, chemical industries, construction companies, bitumen membrane producers and retailers. This research has been co-funded in 2009 by the European Commission within the Seventh Framework Programme (FP7).

PRIOR ART

In the construction industry is known the use of multilayer bituminous based composites.

These systems are distinguished mostly for their waterproofing, soundproofing or insulating characteristics; other characteristics, such as those aesthetic, those relative to an anti-slip property and to stability in time and reduced maintenance, are also desirable.

Another appreciated feature is the ability to reflect sun rays, so contributing to the building thermal comfort and the decrease of energy consumption.

In the known art there are provided technical solutions concerning the application of a reflective layer on the surface of a roof support. For example in the European Patent n. EP 1985775 it is disclosed a flexible membrane roof covering comprising an heat-reflecting outer layer, provided in its turn, by a first support of fibrous reinforcement and a paint layer comprising pigments, preferably titanium dioxide T1O2, and a binder having a polyurethane polymer component and optionally an acrylic polymer component, said first support of fibrous reinforcement being in contact with a sealing layer, preferably a bituminous one.

The flexible membrane according to the above-mentioned prior art shows several interesting advantages but the patent description doesn't provide evidence about coupling of said fibrous reinforcement with the substrate of liquified bitumen, allowing therefore to be produced cost effectively in any traditional bitumen membrane production line.

The European Patent n. EP 0704297 discloses a flexible preformed multilayer membrane for waterproofing structural surfaces comprising a self-adhesive bituminous layer containing oil and a polymeric support which adheres, in a nonremovable way, to said bituminous layer.

Said polymeric support comprises a first and a second polymeric layer, said first polymeric layer comprising on its turn an additive capable of reflecting light and said second polymeric layer being positioned between said first layer and the bituminous layer; and at least one polymeric film which is oil-resistant and oil- impermeable and which is positioned between said first layer and said bituminous layer.

Although the flexible multilayer membrane according to the above-mentioned patent is waterproof, reflective and is also provided by non-discoloring characteristic, the patent description does not prove the required mechanical properties that are needed to maintain adherence in the long term between the composite layers.

Moreover, U.S. Patent no. 7,422,989 discloses a roofing membrane with high solar reflectance comprising a bituminous support, an intermediate layer comprising a reinforcing material and a top layer comprising a heat-reflecting powder coating comprising, in its turn, at least one polymeric binder based on polyamide and acrylic or methacrylic acid and at least one heat-reflecting pigment, preferably titanium dioxide TiO₂.

The membrane according to the above-mentioned patent is resistant to thermal stress and has a pleasant aesthetic appearance, but the scale up of the described manufacturing process has the disadvantage to imply a complex technical implementation.

Other technical solutions are known such, for example, those described in U.S. 2011/0064874, U.S. 2008/0248257, WO 2005/115736, WO 2005/116127; however, all these solutions, while providing coatings with high reflectance, shows one or more of the drawbacks already mentioned above.

Therefore there is still the need to identify a multilayer coating for covering roofs which, in addition to being reflective, it is provided by a suitable mechanical resistance, it is resistant to permeation of the bituminous component, it is capable to avoid discoloring and staining over time.

Another need felt is to locate a multilayer coating for covering roofs with, besides the aforementioned characteristics, is also provided by anti-loosening property, anti-shrinkage property and adequate flexibility and weight.

In parallel there is also still a need to identify a method of producing a multilayer coating for covering roofs feasible at high temperatures, so as to reduce the modifications needed to the already existing production system.

OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION

It is therefore an object of the present invention to provide a multilayer system for roof covering, as well as relative manufacturing process, to solve the above mentioned disadvantages of the known technical solutions.

In particular, it is an object of the present invention to provide a waterproofing composite having a bituminous base with reflective properties of the solar rays and having also anti-breaking, anti-infiltration, anti-permeation properties of the bituminous component, anti-loosening and anti-shrinkag e, and that is also capable to not discolor and stain over time. More precisely, it is an object of the present invention to provide a multiple layer surface prefabricated, provided by properties listed above, suitable for application on said composite.

Furthermore, it is a primary object of the present invention to provide a process for the production of the multiple layer prefabricated surface that is easy to integrate into already existing bituminous membrane manufacturing processes. Furthermore, it is an object of the present invention the use of said composite for covering roofs, and the relative method of installation.

These and other objects of the present invention are achieved through the multiple layer prefabricated surface, the composite comprising said multiple layer and the corresponding production processes, comprising the features claimed in the appended claims, which form an integral part of the present invention.

The multiple layer and the corresponding prefabricated composite for covering roofs according to the present invention:

thanks mainly to the reflective portion, reduce substantially the roof temperature; thanks mainly to the characteristics of the fibrous reinforcement in the top layer, allow to achieve good results in terms of uniformity of coating, resistance to shrinkage and abrasion;

thanks mainly to the adoption of an oil barrier, it is easy to apply by hot lamination without modifying the already existing manufacturing units and allow to achieve the resistance to infiltration and on the permeation of the bituminous component during long exposure time.

DESCRIPTION OF THE FIGURES

Further features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments of the invention not exclusive, which are described as non-limiting examples with reference to the accompanying drawings, wherein:

Fig 1 shows schematically a multiple prefabricated layer reflective surface of the solar rays according to the invention;

Fig 2 shows schematically a first embodiment of the composite for the covering of roofs, comprising the multiple prefabricated layer of Fig. 1; Fig 3 shows schematically a second embodiment of the composite for the roof covering comprising the prefabricated layer of Fig. 1.

These drawings illustrate various aspects and embodiments of the present invention and, where appropriate, structures, components, materials and / or similar elements are indicated in different figures with the same reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible of various modifications and alternative implementations, certain of its preferred embodiments will be described below in detail.

It should be understood, however, that there is no intention to limit the present invention to the specific forms described, but, on the contrary, the invention intends to cover all modifications, alternative implementations and equivalents falling within the scope of the invention as defined in the appended claims.

In the following description, therefore, the use of "eg", "etc.". and "o" is not exclusive alternatives without limitation unless otherwise indicated.

The use of "even" means "including, but not limited to," unless otherwise indicated.

With reference to Fig 1, there is shown the multiple prefabricated layer 1

according to the invention.

Said multiple layer 1 comprises:

- A first reflective layer 2a;

- A reinforcing layer 3; and

- A bitumen barrier 4.

Generally, it has to be noted since now that the first reflective layer 2a can be optionally extended by a second reflective layer 2b of the same material, as it will be described in great detail hereinafter.

Said bitumen barrier 4 is joined to said reinforcing layer 3; preferably such join is obtained through lamination, for technical reasons which will be described in great detail in the following, as well as the relative advantages.

Optionally, said multiple layer 1 may also comprise a second reflective layer 2b. The overall thickness of said multiple layer 1 may vary between 0.1 mm and 0.8 mm, but preferably is 0.15 mm ; enhanced reflective and insulating properties are present when each of said layer 2a, 2b has a thickness of at least 0,3 mm.

Each of said first and second reflective layer 2a, 2b are preferably constituted by a layer of polyurethane modified acrylic paint . Said paint preferably comprise functional additives like

- a ceramic microparticle paint additive to obtain a highly solar reflective, low thermal conductivity and low emissive paint coating (such as "SurfaPore Thermodry ®" made by NANOPHOS SA),

- a nanostructured silicon based particle emulsion for water repellency that

creates a moisture barrier (such as "SurfaPore C ®" of the same company NANOPHOS SA),

a nanoscaled (in average < 150 nm) 3-layer-silicate with a non-swelling, illitic structure (such as " Arginotec ®" from the company B + M Nottenkamper GmbH) to improve UV resistance, mechanical properties of the surface (in particular abrasion) and fire resistance properties.

Said first and second reflective layer 2a, 2b give the prefabricated multiple layer 1, the property of reflecting solar rays; furthermore, thanks to the use of its specific additives, said first and second reflective layers 2a, 2b also ensures a high abrasion resistance properties.

Said reinforcing layer 3 is a nonwoven material and it is preferably made of polyamide thermobonded and "spunbond" material (the textile industry has conventionally adopted this term for a particular process of formation of nonwovens; this technology basically provides that filaments are extruded, drawn, and laid on a transport belt to form a web which is thermally bonded in a subsequent process), the specific weight of said reinforcing material can vary between 25 g/m² and 45 g/ m², but preferably is equal to 35 g/ m².

With reference to spunbonding it has to be noted that fabrics are produced by depositing extruded, spun filaments onto a transport belt in a uniform random manner followed by bonding the fibers. The fibers are separated during the web laying process by air jets or electrostatic charges. The collecting surface is usually perforated to prevent the air stream from deflecting and carrying the fibers in an uncontrolled manner. Bonding imparts strength and integrity to the web by applying heated rolls or hot needles to partially melt the polymer and fuse the fibers together. Since molecular orientation increases the melting point, fibers that are not highly drawn can be used as thermal binding fibers. Polyethylene or random ethylene-propylene copolymers can be used as low melting bonding sites. Said reinforcing layer 3 allows adhesion of the coating to the layers underneath and becomes the main carrier of the prefabricated top layer.

Said bitumen barrier 4 is constituted by a material impermeable to the bitumen, preferably when it is in liquid form and having a temperature up to 170 ° C; it is preferably constituted by PET, (Polyester) or PVB (polyvinyl butyral) or EVA (ethylene vinyl acetate), the thickness of said barrier can vary between 20 and 70 microns.

Said bitumen barrier 4 gives the multiple prefabricated layer 1 the property to prevent the bituminous underneath part to permeate in the surface layers during manufacture, installation and operating life of the multiple layer itself.

Property of mechanical strength (durability, anti-loosening, etc.) become particularly evident since, during the lamination of the bitumen barrier 4 on said nonwoven layer, a mechanical anchoring is produced thanks to the partial dissolution of the bitumen barrier and to its penetration into the nonwoven layer (for example for about 0.02 mm).

The multiple layer 1, as stated, is prefabricated in order to be used as such or, preferably, to be applied to a composite bituminous roof covering.

Generally a method of manufacturing a composite 10 according to the invention comprises the step of

i) laminating the multiple prefabricated layer 1 to the bituminous support, having said bituminous support a temperature comprised between 100°C and 170°C .

The production process (or method) of a composite 10 can also optionally comprise additional steps:

ii) applying a protective film 80 on a surface of the support bituminous 50, 60, 70 and / or; iii) applying a protective film 80 on a surface of the multiple layer 1, precisely on the reflective surface exposed to the outside.

The production process, or method, of said multiple layer 1 substantially comprises the following steps:

i) preparing a polyamide material and subjecting it to "spunbonding" to produce a web;

ii) subjecting the article produced in the previous step i), to thermobonding thereby obtaining a reinforcing layer 3;

iii) applying said reinforcing layer 3 to said bitumen barrier 4, preferably of the type above indicated by a process of hot lamination using a flat bed lamination unit;

iv) preparing a polyurethane modified acrylic paint supplemented with specific additives, preferably of the type above indicated, and applying, by means of coating, a first layer 2a above the intermediate product obtained in the previous step iii), thereby obtaining said multiple prefabricated layer 1. Coating of the reflective paint to this reinforcing layer is preferably made by "slop padding" (Kiss roll); further alternative coating techniques that can be adopted are "doctor blading" and "spraying".

Optionally, said method of production of said multiple layer 1 may also comprise the following step:

v) preparing an additional quantity of polyurethane modified acrylic paint with functional nanoadditives and applying a second layer 2b above the intermediate product obtained in the previous step iv), thereby obtaining said multiple layer prefabricated 1.

Technical machines and equipment used for the realization of said process are of the traditional type, generally known in the technical field of reference, and will therefore not be described here in detail.

With reference to Figure 2, a first embodiment of the composite 10 for roof covering comprising a multiple surface prefabricated layer 1, above described in detail, is shown.

Said first embodiment of the composite 10 comprises: - a multiple prefabricated layer 1 comprising, in turn:

• a first reflective layer 2a;

• optionally, a second reflective layer 2b;

• a reinforcing layer 3; and

· a bitumen barrier 4;

- a bituminous support, comprising in turn:

• a first bituminous layer 50;

• a second reinforcing layer 60; and

• a second bituminous layer 70.

Optionally, said first embodiment of the composite 10 may further comprise:

- a protective film 80.

The overall thickness of said bituminous support of said first embodiment of the composite 10 can vary between 1 mm and 5 mm, but is preferably equal to 3.5 mm; consequently the overall thickness of said first embodiment of the composite 10 can vary between 1.1 mm and 5.8 mm, but preferably is equal to 3.7 mm.

The above-described configuration of the first embodiment of the present invention, comprising two bituminous layers and a further reinforcement layer, is particularly suitable for coating roofs of new construction or to be applied over old and worn sheaths.

Each of said first and second bituminous layer 50, 70 is substantially constituted by polymer modified bitumen.

A great variety of polymeric additives is used to improve the properties of bitumen such as cold flexibility, heat resistance, flow characteristics, adhesion, ageing resistance a.s.o.

Polymers mainly used are SBS, SEBS, SIS, SB(R), EP(D)M, APP (or APAO), IPP, EVA, or P(I)B. Composition, manufacturing process and property improvements are state of the art.

The present invention can be applied to the roof by "torch-on", "self-adhesive" or "pour and roll" technique. Hot air or suitable gas burners are used to burn away the film 80 and to liquefy the polymer bitumen below the reinforcement 60 to weld the sheet to the

underground.

Alternatively, to add self-adhesive properties to the above described

compositions, natural and/ or synthetic resins such as hydrocarbon resin or colophony resin are added as well as natural, synthetic or mineral oils.

Composition of self-adhesive polymer bitumen is state of the art.

The waterproofing non-woven materials having self-adhesive properties are applied to the underground by detaching the protective film 80 from the lower surface of the sheet and to press it to the underground.

Said first and second bituminous layer 50, 70 give the composite 10 enhanced mechanical and thermal characteristics, in particular in terms of waterproofing. Said second reinforcement layer 60 is preferably made of polyester and / or glass fibers; the specific weight of said reinforcing material can vary between 60 g/ m2 and 350 g/m2.

Said second reinforcing layer 60 confers on the composite 10 enhanced mechanical properties, in particular in terms of strain resistance.

Said protective film 80 is applied optionally in order to protect the superficial part of the bituminous support which come into contact with the roof or with the sheath, and must be removed by hot flame ("torch-on" process, "pour and roll" application) or by manual detachment in case of self-adhesive polymer bitumen composition. Before installation said protective film 80 may also be applied to the multiple layer 1 to prevent the surface from damaging during application, more in detail it has to be applied to the reflecting surface exposed to the outside (such embodiment is not shown in the attached figures).

The method of manufacturing said composite 10 comprises substantially the following steps:

a) preparing the reinforcing material 60 comprising polyester and / or glass fibers and subjecting it to lamination;

b) feeding the intermediate product 60 obtained in the previous step a) on a conveyor belt, subjecting it first to impregnation with bitumen or polymer bitumen in an impregnation tank and then pressing it in a working station comprising rotating cylinders;

c) passing the intermediate product obtained in the previous step b) in a coating station where the polymer modified bitumen, taken from special tanks, is spread on the upper surface and on the lower surface of said intermediate product obtained in the previous step b), and thereby obtaining the bituminous support 50, 60, 70;

d) in a calendering station, laminating said multiple prefabricated reflective layer 1 on said bituminous support, said lamination occurring at a temperature between 135°C and 175 ° C, thereby obtaining the composite 10.

The method of manufacturing said composite 10 may also comprise the further following steps:

e) applying a protective film 80 on a surface of the support bituminous 50, 60, 70 and / or;

f) applying a protective film 80 on a surface of the multiple layer 1, precisely on the reflective surface exposed to the outside.

Machines and equipment used for the realization of the above process are of the traditional type, known in the technical field of reference, and will therefore not be described here in detail.

With reference to Figure 3, is shown a second embodiment of the composite 100 for the roof covering, comprising said multiple prefabricated layer 1 described above in detail.

Said second embodiment of the composite 100 includes:

- a multiple prefabricated layer 1 comprising, in turn:

· a first reflective layer 2a;

• optionally, a second reflective layer 2b;

• a reinforcing layer 3; and

• a bitumen barrier 4, and

- a bituminous mono-layer support 500.

Optionally, also said second embodiment of the composite 100 can also include: • a protective film 80 both on top and/ or back side of the material. Bituminous support thickness of said second embodiment of the composite 100 may vary between 0.3mm and 3mm, but preferably is 2mm; consequently the overall thickness of said first embodiment of the composite 10 can vary between 0.5mm and 3.2mm, but preferably is 2.2 mm.

The above-described configuration of the second embodiment of the present invention, comprising a support bituminous mono-layer, is particularly suitable for application on already existing bituminous membranes roofs which, while having still substantially unchanged sealing capacity, require a long lasting treatment to increase their solar reflectance.

Said bituminous mono-layer support 500 comprises substantially polymer modified bitumen (to be welded or with self-adhesive properties) and is adapted to give the composite 100 improved, mechanical and thermal capacities, in particular in terms of waterproofing.

The production process of said composite 100 substantially comprises the following steps:

A) feeding on a conveyor belt the multiple prefabricated reflective layer 1;

B) passing said multiple prefabricated reflective layer 1 in a coating station where the polymer modified bitumen, taken from a dedicated tank, is spread on the lower surface of said multiple prefabricated reflective layer 1, thereby obtaining the composite 100.

The production process of said composite 100 can also comprise further following steps:

C) applying a protective film 80 on the surface of the bituminous support 500; and/ or

D) applying a protective film 80 on the surface of the multiple layer 1, precisely on the reflective surface exposed to the outside.

BEST EMBODIMENTS OF THE INVENTION As aforesaid, while the present invention is susceptible of various modifications and alternative implementations, two best embodiments will be described below in detail; it is understood that said two best embodiments are non-limiting examples of the present invention and they are given with the sole purpose of highlighting the features and the results achieved by means of the multiple prefabricated layer according to the present invention and the composite obtained therefrom.

The two best embodiments relate to version n.lO (waterproofing of new roofs or very old membranes) and version n. 100 (improvement of the reflectance of already efficient membranes).

First best embodiment:

Reference is substantially made to Fig. 2.

Total thickness: approximately 4.2 mm.

Description of layers is made from top to bottom.

The prefabricated reflective layer incorporating a bitumen barrier is made of: -Two layers of polyurethane modified acrylic paint comprising the following additives: a ceramic microparticle paint additive to obtain a highly solar reflective, low thermal conductive and low emissive paint coating (such as "SurfaPore Thermodry ®" made by NANOPHOS SA); a nanostructured silicon based particle emulsion for water repellency that creates a moisture barrier (such as "SurfaPore C ®" of the same company NANOPHOS SA); a nanoscaled (in average < 150 nm) 3-layer-silicate with a non-swelling, illitic structure (such as " Arginotec ®" from the company B + M Nottenkamper GmbH) to improve ageing resistance (UV, barrier against influences from outside), mechanical properties of the surface (density in correlation with elasticity) and fire properties;

- Reinforcing layer: a nonwoven made of polyamide thermobonded and

"spunbond" material with specific weight of 35g/ m². Coating of the reflective paint to this reinforcing layer is made by slop padding (Kiss roll) to get an even coating and a good distribution of agents, afterwards the surplus coat should be removed by film spreader. -Bitumen barrier: PVB (polyvinyl butyral) thin film having a thickness of -50 microns, which is enough to guarantee both resistance to liquefied bitumen (170°C) and flexibility during application on roofs.

The bituminous support is made of a waterproofing layer: ~ 4 mm, consisting of a non-woven reinforcement (~ 1.6 mm, 200 - 300 g/m²) impregnated with bitumen (-800 - 1200 g/ m²); a waterproofing layer (~ 1.4 mm) above and a self-adhesive layer (~ 1 mm) beneath the reinforcement.

A release foil is also provided.

Second best embodiment:

Reference is substantially made to Fig. 3.

Total thickness: approximately 2.8 mm.

Description of layers is made from top to bottom.

The prefabricated reflective layer incorporating a bitumen barrier is equal to best embodiment 1. The bituminous mono-layer support is 2mm and it is not reinforced. Being much thinner and light than embodiment 1, it confers to the product a greater flexibility and reduced cost but can be indicated only to increase reflectance of already efficient waterproofing systems.

The following validation tests were carried on a sample equivalent to best embodiment 1:

- conventional tests for bituminous membranes;

artificial weather resistance;

- reflectance;

A) CONVENTIONAL TESTS FOR BITUMINOUS MEMBRANES

The tests were performed according to international standard procedures.

As it can be seen from the following Table, the invention passed all conventional tests of the bituminous roof industry to validate a product to the market. Abrasion resistance and dynamic impact, thanks mainly to the mineral additives and the non woven reinforcement, show a particularly interesting value. Tests Standard Desired Obtained Results results

Visible Defects EN 1850-1 none none

Thickness EN 1849-1 4,0 mm 4,01

Weight 5 kg/m² 4,9

Cold Flex. EN 1109 < -20°C -25

Heat resistance EN 1110 > 120°C 121

Tensile EN 12311-1 > 700 N/5cm 1108 / 872 (1/c)

Elongation > 15% 36/32 (1/c)

Dimensional Stability EN 1107-1 < 0,35% 0.25

Waterproofness EN 1928 proc. 200 kPa/24h 210

B

Waterproofness after EN 13897 -10°C/10% 205

Stretching

Static Impact EN 12730 15 kg (A+B) A:20; B: kg

Dynamic Impact EN 12691 800 mm (A+B) A: 1500; B:>1750

Tear Resistance. EN 12310-1 > 200 N L: 369; C: 566

Initial Peel Resistance EN 12316-1 > 150 N/5cm 207 of the prefabricated

layer

Peel resistance after 14 EN 12316-1 > 150 N/5cm 191 days in hoven (70°C)

Shear Resistance Joints EN 12317-1 > 500 N/5cm 731

Abrasion resistance of EN 12039 < 30% 0%

the Top Coat

External Fire Exposure CEN TS 1187 Passed Passed

to roof

Ignitability EN 11925-2 Class E Class E B) ARTIFICIAL WEATHERING RESISTANCE

This test was performed with the objective to test resistance of the overall compound under harsh conditions. The results of the first samples indicated the need to reinforce the system with a bitumen barrier since delamination and spots occurred due to migration of bitumen on the top layer after a long exposure. The test was performed according to EN 1297: exposure cycle = 300 min dry + 60 min wet; no irradiation during wet period; exposure time = 2000hrs.

A visual comparison was made between a sample representing the current invention (best embodiment 1) and an equivalent sample without oil barrier: in the first case the system was substantially unaltered while in the second case large black spots and delamination areas could be identified.

C) REFLECTANCE

Reflectance measurements have been determined with respect to solar reflectance in the range of 760 - 2400 nm. The average result for all specimens related to best embodiment 1 is 75,87%, which allows this product to be classified as "cool roof" material.

While the invention presented here have been shown, described and defined with reference to particular preferred embodiments, these references and embodiments given in the above description does not imply any limitation of the invention. It is, however, evident that various modifications and variations can be made without departing from the broader scope of protection of the technical features described.

The preferred embodiments illustrated are merely exemplary and are not exhaustive of the scope of protection of the technical concept presented here.

Therefore, the scope of protection is not limited to the preferred embodiments described in the detailed description, but is limited only by the claims that follow.

Claims

1. Multiple prefabricated layer (1) comprising:

- a first reflective layer (2a);

- a reinforcing layer (3);

said reinforcing layer having a first and a second side opposed each other, said first reflective layer (2a) being joined to said first side

characterized in that it comprises

- a bitumen barrier (4) joined to said second side of said reinforcing layer (3).

2. Multiple prefabricated layer (1) according to claim \, wherein said bitumen barrier (4) is laminated on said reinforcing layer (3).

3. Multiple prefabricated layer (1) according to claim 1 or 2, comprising a second reflective layer (2b).

4. Multiple layer prefabricated (1) according to claim 1 to 3, wherein at least one said first and second reflective layer (2a, 2b) comprises a layer of polyurethane modified acrylic paint with functional additives.

5. Multiple prefabricated layer (1) according to claim 4, wherein said paint includes additives preferably like one or more of the following:

-ceramic microparticles to obtain a highly solar reflective, low thermal conductive and low emissive paint coating,

-a nanostructured silicon based particle emulsion to improve water repellency,

- a nanoscaled (in average < 150 nm) 3-layer-silicate with a non-swelling, illitic structure to improve UV resistance, mechanical properties of the surface (in particular abrasion) and fire resistance properties.

6. Multiple prefabricated layer (1) according to anyone of claim 1 to 5, wherein said reinforcing layer (3) comprises a spunbond non woven from polyamide material.

7. Multiple prefabricated layer (1) according to anyone of claim 1 to 6, wherein, whose total weight varies between 300g/ m² and 500 g/m².

8. Multiple prefabricated layer (1) according to anyone of claim 1 to 7, wherein said bitumen barrier (4) is made of a material impermeable to the bitumen, particularly to liquid bitumen having temperatures below 170 ° C, said material being preferably constituted by PET, (Polyester) or PVB (polyvinyl butyral) or EVA (ethylene vinyl acetate).

9. Multiple prefabricated layer (1) according to anyone of claim 1 to 7, wherein, whose total thickness varies between 0.2 mm and 0.8 mm, and preferably is 0.5 mm.

10. A method of manufacturing a multiple prefabricated layer (1) according to one or more of the preceding claims, said method comprising the steps of:

i) preparing a polyamide reinforcing material and subjecting it to "spunbonding" to produce a web;

ii) subjecting the article produced in the previous step i), to thermobonding thereby obtaining a reinforcing layer (3);

iii) applying said reinforcing layer 3 to said bitumen barrier 4 preferably

constituted by PET, (Polyester) or PVB (polyvinyl butyral) or EVA (ethylene vinyl acetate) by a process of hot lamination using a flat bed lamination unit;

iv) preparing a polyurethane modified acrylic paint with functional nanoadditives and coating it, preferably by means of at least one the techniques known as "slop padding" (or Kiss roll), "doctor blading" and "spraying", as first layer (2a) above the intermediate product obtained in the previous step iii), thereby obtaining said multiple prefabricated layer (1).

v) optionally preparing an additional quantity of polyurethane modified acrylic paint with functional nanoadditives, and applying a second layer (2b) above the intermediate product obtained in the previous step iv), thereby obtaining said multiple prefabricated layer (1).

11. Composite (10) comprising:

- a multiple prefabricated layer (1) according to any one of claims 1 to 9; and

- a bituminous support comprising, in turn:

• first bituminous layer (50);

• a second reinforcing layer (60); and

· a second bituminous layer (70).

12. A method of manufacturing a composite (10) according to one or more of the preceding claims, said method comprising the steps of:

i) laminating the multiple prefabricated layer (1) to the bituminous support, having said bituminous support a temperature comprised between 100°C and 170°C, optionally comprising additional steps:

ii) applying a protective film (80) on a surface of the support bituminous (50, 60, 70) and / or;

iii) applying a protective film (80) on a surface of the multiple layer 1, preferably on a reflective surface exposed to the outside.

13. Composite (100) comprising:

- a multiple prefabricated layer (1) according to any one of claims 1 to 10; and

- a bituminous mono-layer support (500).

14. A method of manufacturing a Composite (100) according to one or more of the preceding claims, said method comprising the steps of:

i) feeding on a conveyor belt a multiple prefabricated reflective layer (1);

ii) passing said multiple prefabricated reflective layer (1) in a coating station where the polymer modified bitumen, taken from a dedicated tank, is spread on the lower surface of said multiple prefabricated reflective layer (1), thereby obtaining the composite (100).

said method optionally comprising additional steps:

iii) applying a protective film (80) on the surface of the bituminous support (500); and / or

iv) applying a protective film (80) on the surface of the multiple layer (1), preferably on a reflective surface exposed to the outside.

15. Composite (10; 100) according to claim 11 or 13, further comprising at least one protective film (80).

16. Use of a multiple prefabricated layer (1) according to any one of the preceding claims for the realization of a waterproofing bituminous based composite (10; 100) for the covering of roofs.