Backing layer of a thermal insulation panel for building having increased adhesion properties to an insulating layer

1. A backing layer of a multilayer thermal insulation panel for building constructions, the thermal insulation panel comprising a central body with an expanded insulating foam, the backing layer comprising:

a reinforcement layer of glass fiber having a first surface and an opposite second surface;

a first coating layer of the reinforcement layer, said first coating layer being attached to said first surface;

a second coating layer of the reinforcement layer attached to said second surface in contact with the insulating foam, the second coating layer comprising an interface with the insulating foam, wherein the interface is free of micro cavities and channeling, said reinforcement layer being interposed between the first coating layer and the second coating layer;

wherein the first coating layer and the second coating layer encapsulate the glass fiber of the reinforcement layer;

wherein said first coating layer comprises a first mixture comprising a first organic binder and a first type of inorganic mineral filler; and said second coating layer comprises a second mixture comprising a second organic binder different from the first organic binder and a second type of inorganic mineral filler different from the first type of inorganic mineral filler, wherein the first organic binder and the second organic binder are each selected from the group consisting of acrylic resins, styrene resins, polyurethane resins, vinyl resins, ethylene vinyl acetate (EVA), polyethylene resins, versatic resins, and combinations thereof.

2. The backing layer of a multilayer thermal insulation panel according to claim 1 , wherein said first mixture and said second mixture further comprise a thickener and water.

3. The backing layer of a multilayer thermal insulation panel according to claim 1 , wherein said first mixture and said second mixture each comprise additives compatible with the insulating foam and adhering to the insulating foam, and wherein said additives of the first mixture and said second mixture comprise additives selected from the group consisting of:

water-repellent or hydrophilic additives,

oleophobic or oleophilic additives,

flame-retardant additives,

reinforcing, elasticizing, levelling additives, antimicrobials, biocides.

4. The backing layer of a multilayer thermal insulation panel according to claim 1 , wherein said inorganic mineral fillers are selected from the group consisting of: carbonates, silicates, oxides, hydroxides, borates, sulfates.

5. The backing layer of a multilayer thermal insulation panel according to claim 1 , wherein said backing layer has a thickness ranging from 0.2 mm to 1 mm and a weight per square meter of surface ranging from 150 g/m 2 to 800 g/m 2 .

6. A multilayer thermal insulation panel for building constructions, comprising a central body made of a thermally insulating material sandwiched between two backing layers, each of the backing layers comprising:

a reinforcement layer of glass fiber having a first surface and an opposite second surface;

a first coating layer of the reinforcement layer, said first coating layer being attached to said first surface;

a second coating layer of the reinforcement layer attached to said second surface in contact with the insulating foam, the second coating layer comprising an interface with the insulating foam, wherein the interface is free of micro cavities and channeling;

said reinforcement layer being interposed between the first coating layer and the second coating layer;

wherein the first coating layer and the second coating layer encapsulate the glass fiber of the reinforcement layer;

wherein said first coating layer comprises a first mixture comprising a first organic binder and a first type of inorganic mineral filler; and said second coating layer comprises a second mixture comprising a second organic binder different from the first organic binder and a second type of inorganic mineral filler different from the first type of inorganic mineral filler, wherein the first organic binder and the second organic binder are each selected from the group consisting of acrylic resins, styrene resins, polyurethane resins, vinyl resins, ethylene vinyl acetate (EVA), polyethylene resins, versatic resins, and combinations thereof.

7. A method for manufacturing a backing layer of a multilayer thermal insulation panel for building constructions, the multilayer thermal insulation panel comprising insulating foam, the method comprising in sequence the steps of:

providing a glass fiber reinforcement layer of the backing, having a first surface and an opposite second surface;

distributing a first fluid mixture comprising a first organic binder and a first type of inorganic mineral filler on top of the first surface of the reinforcement layer;

drying the backing a first time to form a first coating layer of the reinforcement layer;

distributing a second fluid mixture comprising a second organic binder different from the first organic binder, and a second type of inorganic mineral filler, different from the first type of inorganic mineral filler, on top of the second surface of the reinforcement layer and in contact with the insulating foam, wherein the first coating layer and the second coating layer are distributed to encapsulate the glass fiber reinforcement layer;

drying the backing a second time to form a second coating layer of the reinforcement layer, said reinforcement layer being interposed between the first coating layer and the second coating layer;

wherein the second coating layer forms an interface with the insulating foam, wherein the interface is free of micro cavities and channeling;

wherein said first fluid mixture comprises water-repellent or hydrophilic additives; and

wherein said first organic binder of the first coating layer is an acrylic resin and said second organic binder of the second coating layer is ethylene vinyl acetate (EVA).

8. The backing layer of a multilayer thermal insulation panel according to claim 1 , wherein said mixture of the first coating layer comprises water-repellent or hydrophilic additives; and wherein said mixture of the second coating layer comprises additives having compatibility and adhesion with the insulating foam.

9. The method for manufacturing a backing layer of a multilayer thermal insulation panel according to claim 7 ,

wherein the step of distributing the first fluid mixture comprises distributing a fluid mixture comprising water-repellent or hydrophilic additives; and

wherein the step of distributing the second fluid mixture comprises distributing a fluid mixture comprising additives having compatibility and adhesion with the insulating foam.

10. The backing layer of a multilayer thermal insulation panel according to claim 1 ,

wherein said first organic binder is selected from the group consisting of styrene resins, acrylic resins, vinyl resins, and polyurethane resins; and

wherein said second organic binder, different from the first organic binder, is selected from the group consisting of styrene resins, polyurethane resins, vinyl resins, and ethylene vinyl acetate (EVA).

11. A multilayer thermal insulation panel comprising the backing layer according to claim 1 ,

wherein the first organic binder comprises styrene resins and the second organic binder comprises ethylene vinyl acetate, the first organic binder comprises acrylic resins and the second organic binder comprises styrene resins, the first organic binder comprises acrylic resins and the second organic binder comprises vinyl resins, the first organic binder comprises styrene resins and the second organic binder comprises vinyl resins, the first organic binder comprises vinyl resins and the second organic binder comprises ethylene vinyl acetate, the first organic binder comprises acrylic resins and the second organic binder comprises polyurethane resins, the first organic binder comprises styrene resins and the second organic binder comprises polyurethane resins, the first organic binder comprises polyurethane resins and the second organic binder comprises ethylene vinyl acetate, or the first organic binder comprises polyurethane resins and the second organic binder comprises vinyl resins.

12. The backing layer of a multilayer thermal insulation panel according to claim 1 , wherein said first mixture and said second mixture each comprise additives compatible with the insulating foam and adhering to the insulating foam.

13. The multilayer thermal insulation panel according to claim 6 , wherein said first mixture and said second mixture each comprise additives compatible with the insulating foam and adhering to the insulating foam.

14. The method for manufacturing a backing layer of a multilayer thermal insulation panel according to claim 7 , wherein said second fluid mixture comprises additives compatible with the insulating foam and adhering to the insulating foam.