A method for improving the airtightness of buildings using biopolymer-based membranes.

Abstract

The present invention relates to a method for improving the airtightness of a building or a room in a building, comprising the use of a vapor barrier membrane on the inner surface of a wall of the building or a room in a building, characterized in that the vapor barrier membrane is a humidity regulating membrane having an active portion, The active part is an intermediate layer having a thickness of 2 μm to 200 μm, preferably 4 μm to 100 μm, and a water vapor permeability coefficient P 1 The biopolymer has a water vapor permeability coefficient P 1 increases with average relative humidity and is at least 600 Barrer when measured at 23°C and an average relative humidity of 25.5%; and on either side of, and preferably in contact with, the intermediate layer; - two outer layers having a thickness between 100 nm and 20 μm, preferably between 200 nm and 2.5 μm, and independently of each other having a water vapor permeability coefficient P 2 The organic polymer has a water vapor permeability coefficient P 2 two outer layers, each of which has a resistance of 105 to 550 Barrer, preferably 110 to 520 Barrer, and in particular 120 to 500 Barrer, when measured at 23° C. and an average relative humidity of 25.5%; The present invention relates to a method comprising the steps of:

Description

Technical Field

[0001] The present invention relates to a method for improving the airtightness of a building or the airtightness of a room within a building using a vapor barrier membrane having a hydrophilic intermediate layer based on a biopolymer and two outer layers that are relatively more hydrophobic than the intermediate layer.

Background Art

[0002] Humidity regulators or humidity-regulating vapor barrier membranes whose water vapor permeability changes according to the humidity of the air have been known for many years. For example, for the reasons described in WO 96 / 33321, there is a need to obtain a membrane that allows water vapor to easily pass through when the relative humidity (RH) is high (70% - 100% RH) and effectively blocks water vapor when the relative humidity is low (50% RH or less).

[0003] When such membranes are placed on the inner surface of the heat insulation material (the surface facing the inside of the building or room), they prevent, as much as possible, water vapor from entering the space between the membrane and the wall from the inside of the building and condensing on the wall (cold wall) during cold and dry seasons. Conversely, in hot seasons, the high permeability of the membrane allows moisture potentially present within the structural elements of the frame to be discharged towards the inside of the building. This property is not only important, especially in the case of new construction, i.e., when certain elements may have a very high moisture content due to their storage conditions during installation, but also when water infiltrates into an existing structure. In either case, it is important that the entire structure can be dried effectively in a summer-effective manner towards the outside and inside of the building. This need is extremely important especially when the elements constituting the system promote the growth of microorganisms.

[0004] Such vapor barrier membranes exhibit differentiated behavior as a function of the relative humidity conditions of their surroundings and are often called "smart vapor retarder" (SVR) membranes. In this application, the terms "humidity regulator," "humidity regulator," and "smart" are used synonymously when describing changes in the water vapor permeability of a vapor barrier membrane.

[0005] The water vapor permeability of a membrane is generally expressed as the "equivalent air layer thickness" (Sd) against water vapor diffusion. This thickness is expressed in meters and corresponds to the thickness of the air layer that would resist water vapor diffusion to an equivalent degree. Therefore, the greater the equivalent air layer thickness, the lower the water vapor permeability of the membrane. The equivalent air layer thickness (Sd) can be determined according to standards EN1931 and EN ISO12572.

[0006] Humidity-regulating vapor membranes are generally considered to be even more beneficial and effective because their equivalent air layer thickness is high when relative humidity is low and low when relative humidity is high.

[0007] Commercially available humidity-regulating vapor barrier membranes, as described in the most advanced technologies, are generally based on synthetic organic polymers manufactured from petroleum monomers.

[0008] The most frequently described and used polymers are polyamides, particularly polycaprolactam, polyvinyl alcohol (PVOH), copolymers of ethylene and vinyl acetate, and / or vinyl alcohols (EVA and EVOH). The most hydrophilic polymers (PVOH, EVOH) may be combined in multilayer structures with more hydrophobic thin layers, particularly those based on polyolefins, such as polyethylene, polypropylene, and copolymers of ethylene and propylene.

[0009] Examples of literature describing such "smart" vapor barrier membranes include International Publication No. 2007 / 010388, International Publication No. 2006 / 034381, International Publication No. 2005 / 110892, U.S. Patent No. 7008890, U.S. Patent No. 6808772, and U.S. Patent No. 6878455.

[0010] The objective of the research leading to the present invention was to replace prior art humidity control vapor barrier membranes, which are generally based on petroleum-derived polymers that are not biodegradable, with humidity control vapor barrier membranes based on bio-derived and / or biodegradable polymers. These bio-derived and / or biodegradable polymers are hereinafter referred to as "biopolymers." Biopolymers are preferably based on bio-derived materials, i.e., bio-derived materials that can be regenerated in a short period of time. In a particularly preferred embodiment, the biopolymer used in the membrane of the present application is both bio-derived and biodegradable.

[0011] Biopolymers derived from living organisms include natural organic polymers that exist naturally in biomass, organic polymers obtained by physically and / or chemically modifying these natural polymers, and synthetic organic polymers obtained by polymerization of biologically derived components.

[0012] Such biopolymer-based membranes, such as those based on cellulose, chitosan, or poly(3-hydroxybutyrate) (PHB), are known and are used as alternatives to films based on petroleum-derived synthetic polymers, particularly in the field of food packaging. In this field, membranes are generally required to provide water vapor permeability that is relatively independent of humidity and temperature conditions. Furthermore, in the field of food packaging, the service life of packaging films is quite limited, generally ranging from a few days to a few weeks, or at most a few months. In contrast, in the field of vapor barrier membranes, a long service life of at least several years, or even several decades, is required.

[0013] Biopolymer-based membranes are often somewhat hydrophilic and have high permeability to water vapor. The equivalent air layer thickness of these membranes is generally less than 1 m, and its absolute value hardly changes with the relative humidity of the surrounding atmosphere. Therefore, these membranes maintain extremely high permeability to water vapor regardless of ambient conditions.

[0014] While we do not wish to be constrained by any particular theory, the low fluctuations in the water vapor transmission rate of these somewhat hydrophilic membranes may be due to the plasticizing effect of water "dissolving" within the membrane, even at low humidity. The higher the ambient humidity, the more the membrane material becomes plasticized by water, and the easier it is for water molecules to diffuse within the membrane.

[0015] Therefore, the main drawback of these biopolymer membranes is that, when intended for their possible use as humidity-regulating vapor barriers, they cannot function satisfactorily during cold, dry seasons because their permeability to water vapor remains too high overall at low relative humidity. Thus, membranes made solely of cellulose would not be able to form a sufficient barrier against water vapor entering from inside a building, nor would they be able to effectively prevent water vapor from entering the space between the membrane and the wall and condensing within the barrier and on the inner surface of the outer wall. [Overview of the project] [Problems that the invention aims to solve]

[0016] In summary, hydrophilic membranes based on biopolymers used in food packaging remain too permeable to water vapor under low relative humidity conditions (cold seasons). Therefore, they are not "smart" enough to function properly as vapor barriers in the field of thermal insulation of buildings, particularly for improving airtightness and managing water vapor flow within buildings. [Means for solving the problem]

[0017] This invention is based on the remarkable discovery that it is possible to significantly improve the "smartness" of biopolymer-based membranes, thereby adapting them for use as vapor barrier membranes in the building sector by applying very thin layers of low water vapor permeability polyester to each of their two surfaces.

[0018] This discovery was even more surprising considering that highly hydrophobic polyesters deposited on both sides of a biopolymer membrane possess water vapor permeability independent of ambient relative humidity. In other words, a membrane consisting solely of these hydrophobic polymers would not have any humidity-regulating properties. Therefore, it was impossible to predict that depositing these similar hydrophobic polyesters onto the surface of a membrane made of one or more hydrophilic biopolymers would significantly improve its "smartness" by enabling extremely low water vapor permeability in dry conditions and high water vapor permeability in humid conditions. [Modes for carrying out the invention]

[0019] Therefore, this application relates to a humidity control vapor barrier membrane having an active portion, This active part is: - An intermediate layer having a thickness of 2 μm to 200 μm, preferably 4 μm to 100 μm, and consisting of a biopolymer having a water vapor transmission coefficient P1, wherein the water vapor transmission coefficient P1 increases with average relative humidity and, when determined at 23°C and an average relative humidity of 25.5%, is at least 600 Barrer, And, on both sides of this intermediate layer, and preferably in contact with the intermediate layer, - Two outer layers, made of an organic polymer having a thickness of 100 nm to 20 μm, preferably 200 nm to 2.5 μm, and independently of each other having a water vapor transmission coefficient P2, where the water vapor transmission coefficient P2 is 105 to 550 Barrer, preferably 110 to 520 Barrer, particularly 120 to 500 Barrer when determined at 23 °C and an average relative humidity of 25.5%. has.

[0020] It also relates to a method for improving the airtightness of a building or a room within a building, which includes using a vapor barrier membrane on the inner surface of the wall of the building or the room within the building, and the vapor barrier membrane is a humidity-regulating vapor barrier membrane having an active part. This active part is:[[]]END]] - An intermediate layer, made of a biopolymer having a thickness of 2 μm to 200 μm, preferably 4 μm to 100 μm, and having a water vapor transmission coefficient P1, where the water vapor transmission coefficient P1 increases with the average relative humidity and is at least 600 Barrer when determined at 23 °C and an average relative humidity of 25.5%. And, on both sides of this intermediate layer, and preferably in contact with the intermediate layer,[[]]END]] - Two outer layers, made of an organic polymer having a thickness of 100 nm to 20 μm, preferably 200 nm to 2.5 μm, and independently of each other having a water vapor transmission coefficient P2, where the water vapor transmission coefficient P2 is 105 to 550 Barrer, preferably 110 to 520 Barrer, particularly 120 to 500 Barrer when determined at 23 °C and an average relative humidity of 25.5%. has.

[0021] The active part of the membrane is preferably a three-layer structure consisting of an intermediate layer and two outer layers as defined above.

[0022] The permeation coefficients P1 and P2 are those of the polymers forming the intermediate layer and the outer layer, respectively. They correspond to the ratio of the water vapor mass flow rate (Q) passing through the area (A) of the membrane of the polymer being tested having a given thickness (E) under the influence of the water vapor pressure difference (dP) existing on both sides of the membrane.

[0023] [Number]

[0024] They are measured according to the experimental protocol described in detail below and are expressed in "Barrer", that is, the mass flow rate Q is cm per second 3 (under normal pressure and normal temperature), the thickness E is expressed in cm, the area A of the passed region is cm 2 and is expressed in, and the water vapor pressure difference (dP) is expressed in cmHg (see especially S.A. Stern, Journal of Polymer Science Part A-2, vol. 6 (1968), pages 1933-1934).

[0025] Thus, the membrane of the present invention includes a relatively thick layer (intermediate layer) based on a hydrophilic biopolymer, which is coated on both of its surfaces with a continuous layer (outer layer) of a hydrophobic polymer.

[0026] The two outer layers generally have a thickness smaller than that of the intermediate layer. The ratio of the thickness of the intermediate layer to the thickness of each outer layer is preferably 1.5 / 1 to 1000 / 1, preferably 2 / 1 to 5OO / 1, particularly 3 / 1 to 200 / 1.

[0027] The two outer layers preferably are in direct contact with the intermediate layer, that is, the interface between the layers preferably has no adhesive present.

[0028] In a less desirable embodiment, the outer layer is bonded to the intermediate layer by an adhesive, the adhesive preferably having a permeability coefficient P3 greater than permeability coefficients P1 and P2. In other words, the adhesive should not provide resistance to water vapor diffusion greater than the resistance from each layer constituting the membrane.

[0029] The layers defined above form the "active portion" of the membrane of the present invention. This portion is preferably a membrane obtained in known ways by co-extrusion molding of thermoplastic polymers forming different layers, by thermal bonding of a film (outer layer) on an intermediate layer, or by depositing a coating on both sides of the intermediate layer.

[0030] The active portion, in principle, possesses mechanical strength that allows it to be used alone, i.e., without a support layer. However, especially for active layers with a small thickness (less than 50 μm), it may be advantageous to reinforce it with a mechanical structure that is air-permeable, and therefore whose resistance to water vapor diffusion is negligible compared to the resistance of an air-impermeable active layer.

[0031] Therefore, in advantageous embodiments, the vapor barrier membrane further comprises an air-permeable reinforcing or protective layer that is in direct contact with the active portion, i.e., one of the outer layers. This support layer may be an air-permeable grid, a porous plate, an open foam, or a woven or nonwoven fabric. This is preferably an air-permeable woven fabric, preferably a nonwoven fabric. Particularly preferred examples of support layers include nonwoven fabrics made of polypropylene or polyester fibers, or glass fibers. One or more support layers are preferably attached to the active membrane or active layer by adhesion using a polyurethane adhesive. The present invention also includes membranes in which a reinforcing structure, such as a grid or nonwoven fabric, is incorporated within the active portion of the membrane, particularly within the intermediate layer.

[0032] As explained at the beginning, the biopolymers forming the intermediate layer are bio-derived and / or biodegradable organic polymers. They are preferably bio-derived.

[0033] Biopolymers derived from living organisms are preferably selected from the group consisting of the following: - Osides - Proteins, and - Synthetic polymers obtained from bio-derived monomers.

[0034] Osides include heterosides whose hydrolysis produces non-sugars and compounds, as well as holosides, which are polymers consisting solely of sugars.

[0035] Examples of osides that may be used to form the intermediate layer of the vapor barrier of the present invention include those selected from the group consisting of alginic acid, carrageenan, cellulose, especially regenerated cellulose (cellulose hydrate), chitin, chitosan, pectin, dextrin, starch, curdlan, FucoPol, gellan gum, pullulan, and xanthan gum.

[0036] The protein is advantageously selected from the group consisting of gluten, isolated soy protein, zein, whey protein, casein, collagen, and gelatin.

[0037] Most of these bio-derived polymers, extracted from biomass, have a high affinity for water and dissolve or swell in water to form hydrogels.

[0038] As a result, it may be advantageous, or even necessary, to chemically modify them to reduce their hydrophilicity, and in particular to crosslink them to make them insoluble in water.

[0039] Examples of chemically modified biopolymers of biological origin include cellulose esters, particularly cellulose acetates, cellulose ethers (particularly ethylcellulose and hydroxyethylcellulose), nitrocellulose, starch esters, and ethers.

[0040] The third category of biopolymers is formed by polymers synthesized from bio-derived monomers.

[0041] These polymers may be linear or branched, and therefore may be thermoplastic or thermosetting.

[0042] Examples of synthetic polymers obtained from biological monomers may be selected from the group consisting of the following: polyhydroxyalkanoates (PHA), particularly polyhydroxybutyrate (PHB) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), polylactic acid (PLA), polyglycolic acid (PGA), poly(lactide-co-glycolide) (PLGA), polymers obtained by polymerization of lipid monomers, and thermosetting polymers obtained by reaction of monosaccharides, disaccharides, oligosaccharides and / or algitols with polycarboxylic acids and / or polyaldehydes.

[0043] Thermosetting polymers obtained by the reaction of monosaccharides, disaccharides, oligosaccharides and / or algitols with polycarboxylic acids and / or polyaldehydes are well known in the field of binders for mineral wool and are described in detail, for example, in the present applicant's International Applications Nos. 2009 / 080938, 2010 / 029266, 2013 / 014399, 2013 / 021112 and 2015 / 132518.

[0044] As explained at the beginning, petrochemical polymers may be used to form the intermediate layer of the membrane of the present invention, provided that they are biodegradable in the sense of the NF EN 13432 standard.

[0045] The biodegradable biopolymer may be advantageously selected from the group consisting of homopolymer aliphatic polyesters, such as poly(caprolactone) (PCL) and poly(butylene succinate) (PBS), aliphatic copolyesters, such as poly(butylene succinate-co-adipate), aromatic copolyesters, such as poly(butylene adipate-co-terephthalate) (PBAT), and polyesteramides.

[0046] All biopolymers constituting the intermediate layer have a transmittance coefficient P1 of 600 Barrer or more, preferably 600 to 50,000 Barrer, particularly 700 to 30,000 Barrer, and ideally 800 to 20,000 Barrer, as measured under dry conditions (average relative humidity of approximately 25%) at 23°C.

[0047] This transmittance coefficient is measured as follows:

[0048] Five membrane samples of the same thickness (E) are sealed using a sealing product on a test cup containing a desiccant (CaCl2 powder to reduce the relative humidity inside the test cup to approximately 1%). A template is placed on the surface of the film before applying the sealing product to form a defined replacement zone (A) without the sealing product. Various sealing products may be used. For example, the sealing product is a mixture of 60% microcrystalline wax and 40% purified crystalline paraffin.

[0049] The cups produced in this way are placed in a temperature-controlled test chamber (also known as a climate chamber) with a temperature (23°C) and relative humidity (50%).

[0050] Due to the difference in vapor partial pressure (dP) between the inside of the test cup and the chamber, water vapor moves through the membrane's exchange zone. Periodic metering of the cup is performed to measure the steady-state water vapor permeation rate (Q), and by calculation, to measure the water vapor permeability coefficient of the film under consideration, expressed in Barrer. The average of the permeability measured on different assemblies is then calculated and corresponds to the aforementioned permeability coefficient P1.

[0051] The hydrophilic intermediate layer of the vapor barrier membrane of the present invention is covered on two of its surfaces by a continuous layer of an organic polymer that is more hydrophobic and less permeable to water vapor than the intermediate layer. Here, the term "continuous" means that each outer layer completely covers one surface of the central membrane so that the central membrane does not come into contact with the ambient atmosphere. The two continuous layers may have the same chemical properties and the same thickness, or they may have different chemical properties and / or different thicknesses. Each layer is preferably in direct contact with the intermediate layer.

[0052] The transmittance coefficient P2 of each outer layer is 105 to 550 Barrer, preferably 110 to 520 Barrer, and particularly 120 to 500 Barrer. The transmittance coefficient is measured in the same manner as coefficient P1.

[0053] The organic polymer constituting the outer layer is preferably selected from the group consisting of semi-aromatic polyesters obtained by polycondensation of aliphatic polyols and aromatic polyacids. The semi-aromatic polyesters are preferably thermoplastic polyesters obtained by polycondensation of aliphatic diols, such as ethylene glycol, propane-1,3-diol, and butylene glycol, and aromatic diacids, such as terephthalic acid and naphthalic acid. They are preferably selected from the group consisting of poly(ethylene terephthalate) (PET), polybutylene terephthalate (PBT), poly(trimethylene terephthalate) (PTT), and poly(ethylene naphthalate) (PNE), and corresponding copolyesters.

[0054] The permeability coefficient P2 of aromatic polyesters decreases as the degree of crystallinity, and therefore the degree of orientation, of the polyester chains increases. However, it generally remains within the range mentioned above. In this way, P2 can be adjusted as needed by modifying the orientation of the chains within the polyester layer.

[0055] A vapor barrier membrane having an intermediate layer made of cellulose, particularly regenerated cellulose, and two outer layers made of semi-aromatic polyester, preferably poly(ethylene terephthalate), is a particularly preferred embodiment of the vapor barrier membrane used in the method of the present invention.

[0056] The active portion of the vapor barrier membrane used in the method of the present invention has an advantageous thickness of 5.0 μm to 240 μm, preferably 10 μm to 120 μm, and particularly 15 μm to 80 μm, where these values ​​correspond to the active portion (3 layers) of the membrane but do not include possible reinforcing and / or protective structures.

[0057] Preferably, the walls of a room or building whose airtightness is to be improved are insulated, i.e., covered, by a thermal barrier, and the vapor barrier membrane is attached to or incorporated within the thermal barrier. In one embodiment of a method for improving the airtightness of a building or a room within a building, the vapor barrier membrane of the present invention is consequently attached to the thermal barrier in an internal position, preferably in direct contact with it. This attachment may be made by any suitable means that does not significantly reduce the airtightness of the membrane. For example, it may be made by adhesive, stapling, or a mechanical fastening system, the mechanical fastening system may use hooks and woven loops (Velcro® type hook and loop fasteners).

[0058] In another embodiment of the method of the present invention, the vapor barrier membrane is integrated into the barrier and attached to the wall of the room or building at the same time as the barrier. In this case, the membrane is oriented parallel to the two main surfaces of the barrier and is preferably positioned closer to the main surface facing the inside of the room or building than to the main surface facing the wall.

[0059] The thermal barrier may be any water vapor permeable barrier, and in particular includes foam and fiber-based materials. Preferably, it is made of mineral fibers (mineral wool) or natural organic fibers (lignocellulose fibers, cellulose cotton, animal wool), synthetic fibers (polyester fibers), or artificial fibers. It is preferably made of mineral wool. [Examples]

[0060] Four vapor barrier membranes were subjected to evaluation of their water vapor permeability under wet and dry conditions.

[0061] Therefore, each membrane is positioned to seal an aluminum cup using molten paraffin wax (a mixture of 60% microcrystalline wax and 40% purified crystalline paraffin) as a binding product, thereby ensuring airtightness. To measure water vapor transmission in a dry state, calcium chloride is introduced into the cup before sealing it with the membrane to bring the internal relative humidity to approximately 1%. The cup / membrane assembly is then introduced into a climate chamber set to a relative humidity of 50% and a temperature of 23°C to generate a water vapor differential pressure (dP) on both sides of the membrane. The flow rate (Q) of water vapor passing through a zone (A) of the membrane with thickness (E) is measured by measuring the weight of the cup over time, and the transmission coefficient (expressed in Barrer) is calculated using the following formula.

[0062]

number

[0063] The transmission coefficient P1 calculated in this way corresponds to an average relative humidity of 25.5% ((1% + 50%) / 2).

[0064] When measuring water vapor transmission under humid conditions (average relative humidity of 90%), the procedure is the same except that liquid water is introduced into the cup to set the relative humidity to 100%, and the relative humidity inside the climate chamber is set to 80%.

[0065] The equivalent air layer thickness (Sd) is also determined for each membrane according to the standard EN ISO 12572.

[0066] The first membrane is a vapor barrier membrane according to the present invention. It consists of a cellulose intermediate layer having a thickness of 21.4 μm sandwiched between two layers of polyethylene terephthalate (PET), each having a thickness of 800 nm. The permeability coefficient P1 of the cellulose intermediate layer is 5600 Barrer at a relative humidity of 25.5% (23°C) and 34600 Barrer at a relative humidity of 90% (23°C); the permeability coefficient P2 of the PET layer is 300 Barrer (23°C). This does not change significantly with relative humidity.

[0067] The second and third membranes consist solely of cellulose and have the same permeability coefficient P1 as the intermediate layer of the first membrane.

[0068] The fourth membrane is a membrane consisting of a single active layer of polyamide 6 with a thickness of 40 μm, attached to a polypropylene nonwoven fabric. It is commercially available under the name Vario KM Duplex (trademark) (Saint-Gobain Isover).

[0069] The technical characteristics of the membrane (layer composition, thickness, and equivalent air layer thickness under dry and wet conditions) are summarized in Table 1 below.

[0070] [Table 1]

[0071] It can be seen that the difference in equivalent air layer thickness between the three-layer vapor barrier membrane (membrane 1) according to the present invention under dry and wet conditions is significantly stronger than that of all the comparative membranes (membranes 2-4).

[0072] The two cellulose membranes (membrane 2 and 3) maintain an equivalent air layer thickness of less than 1 m (S) under both wet and dry conditions. d They have the following properties: Due to their insufficient humidity control, they are unsuitable as vapor barrier membranes. During dry and cold seasons, such membranes will allow excessive water to pass into the space between the membrane and the building wall. This insufficiently "smart" behavior is brilliantly improved by the presence of two thin PET layers.

[0073] Furthermore, it should be noted that the membrane according to the present invention (membrane 1) has a total thickness (23 μm) that is far lower than the thickness of the active portion of the membrane sold by the applicant, which is equal to 40 μm (VScenario KM Duplex (trademark)). The superior performance of the membrane according to the present invention results in a reduction in raw materials and, consequently, a reduction in costs. This disclosure includes the following aspects: <Aspect 1> A method for improving the airtightness of a building or a room within a building, comprising the use of a vapor barrier membrane on the inner surface of the wall of the building or the room within the building, wherein the vapor barrier membrane is a humidity-regulating membrane having an active portion. The active portion - An intermediate layer having a thickness of 2 μm to 200 μm, preferably 4 μm to 100 μm, and consisting of a biopolymer having a water vapor transmission coefficient P1, wherein the water vapor transmission coefficient P1 increases with average relative humidity and, when determined at 23°C and an average relative humidity of 25.5%, is at least 600 Barrer, and on both sides of the intermediate layer, and preferably in contact with the intermediate layer, - Two outer layers, each having a thickness of 100 nm to 20 μm, preferably 200 nm to 2.5 μm, and each independently made of an organic polymer having a water vapor transmission coefficient P2, wherein the water vapor transmission coefficient P2 is 105 to 550 Barrer, preferably 110 to 520 Barrer, and particularly 120 to 500 Barrer, when determined at 23°C and an average relative humidity of 25.5%. Having, method. <Aspect 2> The method according to embodiment 1, characterized in that the biopolymer forming the intermediate layer is a bio-derived biopolymer selected from the group consisting of osides, proteins, and synthetic polymers obtained from bio-derived monomers. <Aspect 3> The method according to embodiment 2, characterized in that the oside is selected from the group consisting of alginic acid, carrageenan, cellulose, particularly regenerated cellulose, chitin, chitosan, pectin, dextrin, starch, curdlan, FucoPol, gellan gum, pullulan, and xanthan gum. <Aspect 4> The method according to embodiment 2, characterized in that the protein is selected from the group consisting of gluten, isolated soy protein, zein, whey protein, casein, collagen, and gelatin. <Aspect 5> The method according to embodiment 3 or 4, characterized in that the oside and protein are chemically modified. <Aspect 6> The method according to embodiment 2, characterized in that the synthetic polymer obtained from biological monomers is selected from the group consisting of polyhydroxyalkanoates (PHA), polylactic acid (PLA), polyglycolic acid (PGA), poly(lactide-co-glycolide) (PLGA), polymers obtained by polymerization of lipid monomers, and thermosetting polymers obtained by the reaction of monosaccharides, disaccharides, oligosaccharides and / or algitols with polycarboxylic acids and / or polyaldehydes. <Aspect 7> The method according to embodiment 1, characterized in that the biopolymer is a biodegradable polymer selected from the group consisting of aliphatic polyesters, aliphatic copolyesters, aromatic copolyesters, and polyesteramides. <Aspect 8> The method according to embodiment 7, characterized in that the biodegradable biopolymer is selected from the group consisting of poly(caprolactone) (PCL), poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate), and poly(butylene adipate-co-terephthalate) (PBAT). <Pattern 9> The method according to any one of embodiments 1 to 8, characterized in that the organic polymer constituting the outer layer is selected from the group consisting of semi-aromatic polyesters obtained by polycondensation of an aliphatic polyol and an aromatic polyacid, preferably from the group consisting of poly(ethylene terephthalate), polybutylene terephthalate, poly(trimethylene terephthalate), and poly(ethylene naphthalate), and the corresponding copolyester. <Aspect 10> The method according to embodiment 1, characterized in that the intermediate layer is made of cellulose and the two outer layers are made of poly(ethylene terephthalate) (PET). <Aspect 11> The method according to any one of embodiments 1 to 10, characterized in that the active portion of the membrane has a thickness of 5.0 μm to 240 μm, preferably 10 μm to 120 μm. <Aspect 12> The method according to any one of embodiments 1 to 11, characterized in that the vapor barrier membrane further has a reinforcing layer or a protective layer that is in contact with one of the outer layers of the active portion. <Aspect 13> The method according to any one of embodiments 1 to 12, characterized in that the walls of the building or the walls of the room within the building are covered with a thermal barrier, and the vapor barrier membrane is applied to an internal position relative to the thermal barrier, or the membrane is integrated within the thermal barrier. <Aspect 14> The method according to embodiment 13, characterized in that the heat-insulating material is made of mineral fibers, organic fibers, natural fibers, synthetic fibers, or artificial fibers. <Aspect 15> A humidity-regulating vapor barrier membrane having an active portion, The active portion - An intermediate layer having a thickness of 2 μm to 200 μm, preferably 4 μm to 100 μm, and consisting of a biopolymer having a water vapor transmission coefficient P1, wherein the water vapor transmission coefficient P1 increases with average relative humidity and, when determined at 23°C and an average relative humidity of 25.5%, is equal to at least 600 Barrers, the intermediate layer. and on both sides of the intermediate layer, and preferably in contact with the intermediate layer, - Two outer layers, each having a thickness of 100 nm to 20 μm, preferably 200 nm to 2.5 μm, and each independently made of an organic polymer having a water vapor transmission coefficient P2, wherein the water vapor transmission coefficient P2 is 105 to 550 Barrer, preferably 110 to 520 Barrer, and particularly 120 to 500 Barrer, when determined at 23°C and an average relative humidity of 25.5%. Having, Humidity-regulating vapor barrier membrane.

Claims

1. A method for improving the airtightness of a building or a room within a building, comprising the use of a vapor barrier membrane on the inner surface of the wall of the building or the room within the building, wherein the vapor barrier membrane is a humidity control membrane having a three-layer structure. The aforementioned three-layer structure - An intermediate layer having a thickness of 2 μm to 200 μm and consisting of a biopolymer having a water vapor transmission coefficient P1, wherein the water vapor transmission coefficient P1 increases with average relative humidity and, when determined at 23°C and an average relative humidity of 25.5%, is at least 600 Barre. And, on both sides of the intermediate layer, - Two outer layers, each having a thickness of 100 nm to 20 μm and independently composed of an organic polymer having a water vapor transmission coefficient P2, wherein the water vapor transmission coefficient P2 is 105 to 550 Barre when determined at 23°C and an average relative humidity of 25.5%, Having, method.

2. The method according to claim 1, characterized in that the biopolymer forming the intermediate layer is a bio-derived biopolymer selected from the group consisting of osides, proteins, and synthetic polymers obtained from bio-derived monomers.

3. The method according to claim 2, characterized in that the oside is selected from the group consisting of alginic acid, carrageenan, cellulose, chitin, chitosan, pectin, dextrin, starch, curdlan, FucoPol, gellan gum, pullulan, and xanthan gum.

4. The method according to claim 2, characterized in that the protein is selected from the group consisting of gluten, isolated soy protein, zein, whey protein, casein, collagen, and gelatin.

5. The method according to claim 3 or 4, characterized in that the oside and protein are crosslinked.

6. The method according to claim 2, characterized in that the synthetic polymer obtained from biological monomers is selected from the group consisting of polyhydroxyalkanoates (PHA), polylactic acid (PLA), polyglycolic acid (PGA), polylactic acid-glycolic acid copolymers (PLGA), polymers obtained by polymerization of lipid monomers, and thermosetting polymers obtained by the reaction of monosaccharides, disaccharides, oligosaccharides and / or algitols with polycarboxylic acids and / or polyaldehydes.

7. The method according to claim 1, characterized in that the biopolymer is a biodegradable polymer selected from the group consisting of aliphatic polyesters, aliphatic copolyesters, aromatic copolyesters, and polyesteramides.

8. The method according to claim 7, characterized in that the biodegradable biopolymer is selected from the group consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate, and polybutylene adipate-co-terephthalate (PBAT).

9. The method according to any one of claims 1 to 4 and 6 to 8, characterized in that the organic polymer constituting the outer layer is selected from the group consisting of semi-aromatic polyesters obtained by polycondensation of an aliphatic polyol and an aromatic polyacid.

10. The method according to claim 1, characterized in that the intermediate layer is made of cellulose and the two outer layers are made of polyethylene terephthalate (PET).

11. The method according to any one of claims 1 to 4, 6 to 8, and 10, characterized in that the three-layer structure of the membrane has a thickness of 5.0 μm to 240 μm.

12. The method according to any one of claims 1 to 4, 6 to 8, and 10, characterized in that the vapor barrier membrane further has a reinforcing layer or protective layer that is in contact with one of the outer layers of the three-layer structure.

13. The method according to any one of claims 1 to 4, 6 to 8, and 10, characterized in that the walls of the building or the walls of the room within the building are covered with a thermal barrier, and the vapor barrier membrane is applied to an internal position relative to the thermal barrier, or the membrane is integrated within the thermal barrier.

14. The method according to claim 13, characterized in that the heat-insulating material is made of mineral fibers, organic fibers, natural fibers, synthetic fibers, or artificial fibers.

15. A humidity control vapor barrier membrane having a three-layer structure, The aforementioned three-layer structure - An intermediate layer having a thickness of 2 μm to 200 μm and consisting of a biopolymer having a water vapor transmission coefficient P1, wherein the water vapor transmission coefficient P1 increases with average relative humidity and, when determined at 23°C and an average relative humidity of 25.5%, is equal to at least 600 Barre. And, on both sides of the intermediate layer, - Two outer layers, each having a thickness of 100 nm to 20 μm and independently composed of an organic polymer having a water vapor transmission coefficient P2, wherein the water vapor transmission coefficient P2 is 105 to 550 Barre when determined at 23°C and an average relative humidity of 25.5%, Having, Humidity-regulating vapor barrier membrane.

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