Condensation control material and uses thereof

Abstract

Subject of the invention is a method for controlling condensation in a building. The invention also relates to a condensation control material (6) which comprises, in consecutive order, a nonwoven layer (1), a first adhesive layer (2), a reinforcement layer (3), a second adhesive layer (4), and a release liner (5). Subject of the invention are also buildings and building parts which are covered with the condensation control material, uses of the condensation control material, and methods for its production.

Description

[0001] Condensation control material and uses thereof

[0002] The invention relates to a method for controlling condensation and dripping in a building. The invention also relates to a condensation control material, uses thereof, production methods, and buildings and building parts covered with the condensation control material.

[0003] State of the art

[0004] It is a known problem that condensation can occur in buildings on the interior side of building components which are in contact with the environment. Condensation occurs when the environmental temperature falls sufficiently to cause the temperature of the building part to fall more rapidly than for other parts. Moisture in the air in the interior of the building structure condenses on these colder parts, when they reach the dew point. Typically, condensation is a problem for uninsulated metal roofs or metal frameworks in building such as greenhouses, warehouses, factory halls, agricultural buildings, carports, workshops or garages. Excessive condensation occurs especially if the interior air space is inherently humid. The moisture caused by condensation can damage the building components at which the condensed water is formed, for example by corrosion or mold formation. Moreover, the condensed water can drop or flow into the building interior, causing structural damage. Water dropping into the building is also often not acceptable for other reasons, for example if moisture-sensitive goods are stored or processed inside, if sensitive devices and machinery are inside, or generally for comfort in a work or living space.

[0005] In the art, anti-condensation materials are available which can be attached to surfaces on which condensation occurs. They consists of a moisture absorption layer, which can trap and store condensed water at cold temperature, and can release it at elevated temperature. Such materials can control dripping during temperature changes, for example during the night / day cycle.

[0006] GB 2 206 907 A discloses an anti-condensation composite sheet material for buildings. The moisture absorption layer is an acrylic-based polymer containing fillers, which is also capable of providing thermal insulation. An aluminum foil, which functions as a moisture barrier, is adhesively bonded to the anti-condensation layer. The laminate may comprise an adhesive layer, protected by release paper, for adhesively bonding the composite to an interior surface of a building. The anti-condensation material is produced by coating the anti-condensation material onto the aluminum foil, which has been activated before with an etching primer. However, the properties of such anti-condensation materials could still be improved. It is a general problem that aluminum foil and polymer layers with fillers can break upon stress and strain. Therefore, such materials cannot be applied conveniently, especially onto substrates which are profiled or not easily accessible.

[0007] In the art, also fibrous anti-condensation materials are commercially available. Typically, they consist of a nonwoven layer which is coated with an adhesive layer for attachment to a building part. For example, such a product is DEWEB™ from Nordroofs, IE (product information available at www.nordroofs.ie). The adhesive layer is protected by a siliconized film liner, which is removed, before the nonwoven is attached to a substrate surface. Such fibrous sheet materials are highly flexible and conform easily to a surface. They are applied mechanically to dismantled metal roof parts before integration into the building. Mechanical application is required, because pressure is applied by machinery for uniform bonding. Typically, the composite material is provided in roll form, and applied onto the flat metal substrate with an unwinder device, which also detaches the release liner from the adhesive layer. The device applies pressure and provides a strong adhesive bond over the surface area.

[0008] Frequently, interior building surfaces, such as metal roofs, are profiled. During that process, such fibrous anti-condensation materials are applied mechanically to flat metal parts. Subsequently, the metal sheets are shaped, for example by bending. To avoid damages during profiling, such conventional fibrous anti-condensation materials are highly elastic and flexible. Therefore, they can follow the bending forces, and cover edges of the profiled metal part without rupture or detachment. Finally, the profiled metal part with the anti-condensation cover is integrated into the building.

[0009] Another fibrous condensation control composite for protecting interior surfaces, such as metal roofs, is available from Freudenberg, DE, under the trademark Dripstop®. The composite comprises a nonwoven layer for trapping and releasing water, an adhesive layer and a release layer. According to the manufacturer's instructions, the product is adhered directly onto the flat metal surface by appropriate machinery, before the metal part is profiled and integrated into the building structure.

[0010] US 6,901 ,712 B2 discloses an air and moisture barrier sheet membrane for building surfaces. The sheet membrane of US 6,901,712 B2 comprises a single adhesive layer which can be coated non-uniform onto a nonwoven layer. A plastic film can be heat- bonded onto the opposite side of the nonwoven layer. When the barrier is attached to a building surface via the adhesive layer, the nonwoven layer becomes directly attached to the building surface, whereas the polymer film covers and shields the nonwoven layer. Thus, the nonwoven is not exposed to the building interior and is not capable of absorbing moisture. Moreover, the barrier sheet membrane is incorporated into a building structure, for example between two gypsum boards in a wall structure, as shown in Fig. 2 thereof. Accordingly, the barrier sheet is tightly embedded in the wall. Also for this reason, the barrier sheet is not capable of controlling water which is condensed and accumulates on the wall surface. This is also not the purpose of the barrier sheet material, which shall only prevent long-term vapor diffusion through the wall structure. The term “condensation control” is used in column 1, lines 60 to 63, but in the context of long-term vapor diffusion through building walls. Overall, the sheet membrane of US 6,901,712 B2 is neither intended for, nor capable of condensation control on an interior surface of a building.

[0011] WO 2016 / 106273 A1 relates to rolls comprising an air and water barrier article having opposing first and second major surfaces, a pressure sensitive adhesive disposed on at least the first major surface of the article, and a liner having a first major surface that contacts the opposing second major surface of the article, and at least two adhesion modifying zones disposed between the second major surface of the article and the first major surface of the liner.

[0012] The commercially available fibrous condensation control materials can provide effective protection against damage caused by condensation. However, they could still be improved. It is a problem that the process by which they are applied is relatively complicated. It would be desirable to provide condensation control composites, which can be applied directly to the building interior and also to profiled substrates. Generally, it would be desirable to provide methods and materials for controlling condensation, which can be applied in a simple and convenient manner.

[0013] Problem underlying the invention

[0014] The problem underlying the invention is to provide methods and condensation control materials, which overcome the above-mentioned problems. It is a specific problem to provide condensation control materials and methods, which can be applied conveniently to interior surfaces, especially metal roofs.

[0015] It is a specific problem to provide condensation control materials, and methods for their application, which can be applied directly onto the interior surface after the building construction is complete. Specifically, the materials and methods should be applicable for profiled substrates. It is a further problem to provide respective materials, which can be applied conveniently without machinery, and especially manually.

[0016] Disclosure of the invention

[0017] Surprisingly, it was found that the problem underlying the invention is overcome by methods and condensation control materials according to the claims. Further embodiments are outlined throughout the description.

[0018] Subject of the invention is a method for controlling condensation in a building, comprising the steps, in consecutive order:

[0019] (a) providing a condensation control material which comprises in consecutive order:

[0020] - a nonwoven layer,

[0021] - a first adhesive layer,

[0022] - a reinforcement layer,

[0023] - a second adhesive layer, and

[0024] - a release liner,

[0025] (b) removing the release liner from the condensation control material, and (c) manually attaching the condensation control material, via the second adhesive layer, to an interior surface of the building, wherein the elongation of the condensation control material at 20 N / 5 cm is between 0.5% and 10%, as determined by EN ISO 9073-3.

[0026] The method is for controlling condensation in a building. The condensation control material is capable of capturing condensed water in its interior at relatively cold temperature, and releasing it as water vapor at relatively warm temperature. In this regard, the term “controlling” means that undesirable effects in a building, such as corrosion or molding, which are caused by liquid water from condensation, are reduced or avoided. Specifically, the method can reduce or prevent water dripping from elevated building parts, such as the roof. Further, condensation can be controlled, if the condensation control material is applied directedly to specific parts or regions of the building.

[0027] Herein, the condensation control material is also referred to as “composite material”. This term relates to the material from all layers, before attachment to the surface, as well as to the bonded material from which the release liner has been removed. The composite material is attached such that it covers the surface, to which it is applied. It prevents problems caused by water formed by condensation at the interior surface.

[0028] In the method, the composite material is attached directly to a building surface. It is not attached to a discrete part, before the part integrated into the building. Thus, it is not necessary to dismantle a building part for carrying out the method. For example, when the surface is the inner side of a metal roof, the composite material can be attached directly to the building roof. It is not necessary to provide a dismantled roof or part thereof.

[0029] If desired, the condensation control material can be applied to specific sections of a building surface, for example selectively to a part of a roof at which strong condensation can occur.

[0030] The invention provides a novel method for applying condensation control materials directly to interior surfaces of a building. Thus, the method is simpler than conventional methods, in which anti-condensation materials are attached to flat metal sheets, which are subsequently profiled, and integrated into the building after profiling.

[0031] In the method, the composite material is attached manually. Thus, it is not attached mechanically (by machinery). Preferably, the complete method is carried out manually. The term "manually" means that hand-tools can be used, for example for applying pressure and smoothing the surface. Manual attachment is advantageous, because no machinery is required, as for attaching conventional condensation control materials to dismantled building parts. Therefore, the inventive method is relatively simple. It can be used conveniently for applying the composite material, also when the composite material is repaired or replaced. The method can be especially useful if a condensation problem is encountered in a building, but it is not possible or desirable to dismantle the building parts at which the condensation occurs. Preferably, the method is for commercial use and / or the user is a professional, for example from a construction company or workshop, for example for building construction, renovation or interior design.

[0032] In the inventive method, manual application to the surface of the building is enabled by the structure and properties of the specific condensation control material. The material comprises a nonwoven layer for absorbing and releasing moisture, which is attached to a reinforcement layer by a first adhesive layer. The first adhesive layer provides a strong bond, such that the reinforcement layer is not released from the nonwoven layer during handling, attachment to the surface, and long-term use for condensation protection.

[0033] A second adhesive layer is provided on the other side of the reinforcement layer. The second adhesive layer is for attaching the composite material - and thus for attaching the intimate assembly of nonwoven layer, first adhesive layer and reinforcement layer - to the interior surface of the building. The second adhesive layer is protected by a release liner, which is detached, typically peeled off, before the composite material is attached to the building surface. After laying the composite material onto the surface, pressure can be applied for uniform and strong bonding.

[0034] The condensation control material is a flat material. The layers are assembled over each other in the form of a laminate. Preferably, the condensation control material is provided in roll form, such that it can be conveniently stored and handled. Pieces of desired size can be cut off from the rolls.

[0035] The condensation control material is characterized by a high dimensional stability. Thus, it is relatively stiff and rigid. It has an elongation at 20 N / 5 cm between 0.5 % and 10 %, as determined by EN ISO 9073-3. Preferably, the elongation is in machine direction, more preferably in all directions, i.e. machine direction and cross direction. Preferably, the elongation at 20 N / 5 cm is between 0.5 % and 5 %, preferably in machine direction, more preferably in all directions. It is especially preferred that the elongation at 20 N / 5 cm in one direction, typically in machine direction, is between 0.5 % and 3 %, more preferably between 0.75 % and 2 %. In the present disclosure, the properties of the condensation control material, especially mechanical properties, such as the elongation, are preferably determined without release liner, typically after the release liner has been peeled off.

[0036] When the elongation at 20 N is in the defined range, the material is slightly stretchable by hand with moderate force. This is advantageous, because the condensation control material can be handled, processed and attached conveniently. When processed and applied manually, the pieces can basically maintain their form, and do not exhibit undesirable bending or wrinkling. The material can be attached in a regular straight line when applied in strips over an area. It is also advantageous that the material has a minimum degree of elongation at 20 N of at least 0.5 %, because it has some elasticity and can follow the profile of the substrate. Thus, the material can be bent and stretched manually to a low degree, which renders is suitable for covering edges or irregular surfaces without breakage or detachment. Overall, the elongation in the given range renders the condensation control material suitable for manual handling and processing, and stable and convenient attachment to the interior surface of the building.

[0037] In a preferred embodiment, the interior surface of the building is a metal surface. Preferably, the metal is steel. The metal can be coated, preferably on the other side. Preferably, the composite material is applied directly onto the metal surface. Preferably, the metal surface and / or the building site which comprise the metal surface are uninsulated. This is advantageous, because condensation is especially a problem for metal surfaces, for example uninsulated metal roofs, which can undergo rapid and pronounced temperature changes. Moreover, the composite material can be attached strongly to metal surfaces.

[0038] In a preferred embodiment, the interior surface of the building is profiled. For example, the surface can comprise edges and / or grooves. Preferably, the profile comprises repetitive elements, such as parallel grooves or edges. Preferably, the profile is corrugated or trapezoidal-shaped. Preferably, the surface is a profiled metal roof. It is a special advantage of the inventive method that the condensation control material can be applied directly onto profiled surfaces. This is possible because of the dimensional stability of the condensation control material at 20 N, which provides rigidity and stiffness, in combination with a certain degree of elasticity for manual stretching and bending. Therefore, in contrast to known methods and condensation control materials, also profiled building surfaces can be protected efficiently with the inventive material in a simple and efficient method by hand, without specific machinery.

[0039] Preferably, the interior surface is a side wall, or more preferably a roof surface. It is especially preferred that the roof is a metal roof, more preferably a profiled metal roof. This is advantageous, because inventive product can efficiently control condensation when applied to roofs or side walls. Condensation problem can be especially pronounced for roofs, from which condensed water can drop down.

[0040] The building can be any building in which condensation can occur. The method is especially useful for buildings with a humid interior and / or with metal structures, such as metal roofs, which can be prone to condensation problems. Preferably, the building is a greenhouse, warehouse, factory hall, agricultural building, workshop, garage, office or residential building.

[0041] Subject of the invention is also a condensation control material, which comprises the following layers, in consecutive order:

[0042] - a nonwoven layer,

[0043] - a first adhesive layer,

[0044] - a reinforcement layer, which is bonded to nonwoven layer by the adhesive layer, - a second adhesive layer and

[0045] - a release liner, which covers the second adhesive layer, wherein the elongation of the condensation control material at 20 N / 5 cm is between 0.5% and 10%, as determined by EN ISO 9073-3, preferably without release liner.

[0046] The properties and structure of the condensation control material are preferably adjusted as outlined above for the inventive method. Accordingly, the condensation control material is a composite material which comprises multiple layers, which is provided in sheet form, preferably roll form. The specific structure and combination of the layers provides the advantages for manual application and confers the condensation control effect to the interior building surface, to which it is applied.

[0047] As outlined above, the condensation control material is relatively stiff, whilst having a certain degree of elasticity. The nonwoven layer, first adhesive layer and / or reinforcement layer are selected such that the desired dimensional stability is obtained. Further, the combination of nonwoven layer, reinforcement layer and first adhesive layer provides advantageous condensation control properties, as well as further desirable properties, to the material and the building surface after application.

[0048] The nonwoven layer is capable of trapping and releasing moisture. After attachment to the building surface, it forms the outer surface of the composite, which is exposed to the building interior. In line with the definition of ISO 9092:1988, the nonwoven is a manufactured sheet from fibers, which are bonded by friction and / or cohesion and / or adhesion. Thus, the nonwoven is neither a paper or woven product, nor a plastic material with a polymer matrix, in which reinforcing fibers are merely distributed. Preferably, the fibers are staple fibers, but they can also be continuous filaments. The nonwoven can be prepared by conventional methods, such as dry or wet laying, spunbonding or spunlacing.

[0049] In a preferred embodiment, the nonwoven fiber material does not absorb water. Preferably, the nonwoven fibers are not from hydrophilic fiber material, such as cellulose or viscose. Instead, it is preferred that the nonwoven stores the moisture in its interior. This can be advantageous, because the water can be transported and released more rapidly. In a preferred embodiment, the fibers are polyester (PET), polyamide and / or polyolefin fibers, such as polypropylene or polyethylene fibers. More preferably, the nonwoven comprises or consists of polyester fibers. Such fibers are capable of transporting and storing high amounts of water. They are also suitable for forming dimensionally stable nonwovens.

[0050] The nonwoven can be consolidated by known methods, such as thermal bonding, mechanical bonding, such as needle-punching or hydro-entanglement, chemical bonding, or combinations thereof. Preferably, the dimensional stability, and thus elongation, of the composite material are adjusted at least in part by consolidation of the nonwoven, preferably by thermal bonding, typically via hot air or calendaring. Accordingly, the time and temperature of the thermal bonding can be selected, such that desired dimensional stability is attained. Preferably, the nonwoven is through-air bonded, preferably in an oven. This is advantageous, because the nonwoven is not compressed during bonding. It can remain highly porous, is permissible for vapor and moisture, and can take up relatively high amounts of water.

[0051] In a preferred embodiment, the nonwoven has a basis weight in the range from 20 to 500 g / m2, more preferably from 50 to 200 g / m2, most preferably from 75 to 150 g / m2. Preferably, the thickness is in the range of 0.2 to 20 mm, more preferably of 0.3 to 10 mm, most preferably of 0.5 to 5 mm, or even of 0.75 to 2 mm. Such relatively light and thin nonwovens are advantageous, because they can be handled and processed conveniently by hand.

[0052] Preferably, the fibers have a fineness in the range from 0.5 to 30 dtex, more preferably from 0.5 to 15 dtex, most preferably from 1 to 5 dtex. Such fibers are suitable for providing a fine fiber structure, in which moisture can be transported and stored.

[0053] In a preferred embodiment, the nonwoven is needle-punched. Thereby, various advantageous properties can be conferred to the nonwoven. Needle-punching can create pockets of low fiber density within the nonwoven, in which water can accumulate, and is stored until being released at higher temperature. Further, the needle-punched nonwoven comprises dense regions, which can transport water by the capillary effect. Further, consolidation by needle-punching can support a stiff and stable structure.

[0054] In a preferred embodiment, the nonwoven comprises a mixture of fibers of different fineness and / or type. This can be advantageous, because the finer fibers can provide a capillary effect for water storage and transport, whereas the coarser fibers can confer stability to the nonwoven.

[0055] The composite material comprises a reinforcement layer. For example, the reinforcement layer can be a plastic foil, a fibrous layer, such as a further nonwoven, woven or knitted layer, and / or a scrim. The reinforcement layer confers dimensional stability to the composite material, such that it is suitable for manual handling and application. In this regard, the reinforcement layer stabilizes especially the nonwoven layer. The nonwoven layer is preferably relatively porous and has a relatively low density, such that it can take up and store high amounts of water. It is also desirable that such a nonwoven layer is rather lightweight, such that it can be handled and applied conveniently. Such porous nonwoven layers typically do not have a high dimensional stability. Therefore, the inventive composite combines advantageously a nonwoven layer which is capable of storing high amounts of water, with a reinforcement which confers dimensional stability to the composite.

[0056] In a preferred embodiment, the reinforcement layer is a plastic foil. Surprisingly, it was found according to the invention that a plastic foil, which is laminated to the nonwoven layer, can provide the required dimensional stability, and can confer further properties to the composite material, which are advantageous for handling and use. Without the plastic foil, such porous nonwovens for condensation control tend to be soft and highly elastic. When handled manually, they bend unduly and form wrinkles. In the inventive composite, even a thin plastic foil which is laminated onto the nonwoven can provide the dimensional stability required for processing and handling.

[0057] It is another advantage of plastic foils that they are elastic and / or flexible. Therefore, the reinforcement layer in form of a plastic foil is not damaged when the composite material is deliberately stretched or bent during handling. In contrast, conventional materials based on aluminum foils have no elasticity, and can be damaged when the sheet material is processed. Overall, the inventive composite basically maintains its shape during use and can be handled conveniently. It can be deliberately bent and slightly stretched, without exhibiting uncontrolled knicking or wrinkling.

[0058] Preferably, the thickness of the plastic foil is between 10 and 100 pm, more preferably between 20 and 100 pm, most preferably between 30 and 70 pm. Preferably, the plastic foil has a basis weight in the range from 10 to 100 g / m2, more preferably from 20 to 100 g / m2, most preferably from 30 to 70 g / m2. Such plastic foils are especially suitable for reinforcing the composite material and / or nonwoven layer.

[0059] It is advantageous that a plastic foil can provide a barrier for moisture and / or vapor, which is transported through the nonwoven. Thus, the moisture or vapor in the nonwoven is prevented from contacting the building surface. This is advantageous, because the water is stored only within the nonwoven, and can be released completely when the temperature rises. Moreover, undesirable effects on the building surface, such as corrosion and molding, are prevented.

[0060] Preferably, the plastic of the plastic foil is polyolefin, especially polyethylene or polypropylene, polyamide and / or EVA (ethylene vinyl acetate). In a preferred embodiment, the foil comprises polyethylene or propylene. Especially plastic foils from these materials can provide an efficient water and vapor barrier and confer dimensional stability to the composite material, whilst preserving a certain degree of elasticity. It is especially preferred that the plastic foil is from polypropylene. It was found that the stability of the condensation control material, especially after ageing, can be especially high with polypropylene foil. Optionally, the plastic foil has been corona-treated.

[0061] The nonwoven layer and reinforcement layer are bonded together by the first adhesive layer. The first adhesive is selected such that the bond is durable and stable. It can be a curable adhesive or thermoplastic adhesive. Preferably, the adhesive is curable. In a specific embodiment, the adhesive is a thermoset, which can be cured at enhanced temperature. In the first adhesive layer, the adhesive is completely cured for intimate bonding of the reinforcement layer to the nonwoven. Preferably, the first adhesive is selected from styrene block copolymers (SBC) such as butadiene styrene (SBS), styrene butadiene rubber (SBR), acrylic adhesive and butyl adhesive, polyamide, ethylene-vinyl acetate (EVA), polyethylene and coPET (copolyester). The adhesive is preferably water-based, but can also be solvent-based. In a specific embodiment, the first adhesive is a hotmelt adhesive. The use of a hotmelt adhesive can be advantageous, because the adhesive bonding can be controlled. For example, the temperature for gluing can be between 80 and 200°C, especially between 100 and 180°C. Preferably, the hotmelt adhesive is selected from polyamide, ethylenevinyl acetate (EVA), polyethylene and coPET (co-polyester). Such hotmelt adhesives are generally suitable for bonding nonwovens strongly to sheet materials such as plastic foils. They can provide a strong bond between the reinforcement layer and nonwoven layer, thereby preventing damages and undesired detachment.

[0062] In a specific embodiment, the first adhesive is selected such that it confers dimensional stability to the condensation control material. Thus, the cured adhesive layer has a certain rigidity. This can be advantageous, because the dimensional stability is based on the combination of layers, which can render the overall composite more stable and uniform.

[0063] The second adhesive layer is for bonding the composite material to the building surface. After the release liner is removed, and the composite material is applied to the building surface, the second adhesive is in flat contact to the building surface. Preferably, the second adhesive layer, which covers the reinforcement layer, is a self-adhesive layer. More preferably, the second adhesive is a pressure-sensitive adhesive. Preferably, the second adhesive is partially cured. The adhesive is preferably water-based, but can also be solvent-based.

[0064] Preferably, the second adhesive is selected from styrene butadiene rubber (SBR), acrylic adhesive and butyl adhesive. Such adhesives can provide strong adhesion to metal surfaces. They can also have resistance against moisture and temperature changes, which are encountered at building sites at which condensation occurs.

[0065] The first and second adhesive may comprise additives, such as stabilizers, tackifiers coupling agents, plasticizers, pigments, processing aids and / or antioxidants. As known in the art, such additives can confer desired properties to the adhesives, such as higher bonding strength or compatibility with the adjacent layer.

[0066] Preferably, the amount of the first adhesive is between 5 and 50 g / m2, more preferably 10 and 25 g / m2. Preferably, the amount of second adhesive is between 5 and 80 g / m2, more preferably between 10 and 80 g / m2, most preferably between 15 and 50 g / m2. Such amounts can be advantageous for strong bonding, without adding too much weight to the relatively lightweight composite material. Further, the first adhesive can contribute to the dimensional stability of the composite material.

[0067] The release liner covers the second adhesive layer and protects it from undesirable adhesive bonding or degradation. Preferably, the release liner is a plastic foil or paper, which provides an inert cover over the second adhesive layer. The release liner can be peeled off manually before use. Preferably, the release liner is coated with an inert coating, more preferably siliconized. Release liner materials for protecting adhesive layers are known in the art. The release liner is removed, typically peeled off manually, before the composite materials is attached to the building surface.

[0068] Preferably, the basis weight of the composite material is between 100 and 700 g / m2, more preferably between 100 and 400 g / m2, most preferably between 150 and 350 g / m2, especially preferred between 180 and 280 g / m2, as preferably determined without release liner. The thickness of the composite material can be between 0.5 and 25 mm, preferably between 0.5 and 5 mm, more preferably between 0.5 and 2 mm, most preferably between 0.7 and 1.5 mm. Such relative low basis weight and thickness are advantageous for manual handling and processing. Such a light material can be handled conveniently by hand, even when the building surface is not easily accessible and / or when the user is working under exposed conditions. This is advantageous for improving the safety of the user. For example, the inventive material can facilitate application of the condensation control material to a roof, when the user is on a scaffold or ladder.

[0069] In the method, it is preferred that the condensation control material is provided in step (a) in a shape, such that the substrate can be covered adequately. The material can be cut into a piece of desired size, such as a strip, square, or an irregular form adapted to a surface section. After manual laying over the building surface, the condensation control material is typically smoothened before or during bonding, for example with a flat tool which exerts uniform pressure onto the surface.

[0070] Preferably, the tensile strength of the composite material is between 100 and 600 N / 5 cm, more preferably between 100 and 400 N / 5 cm, as determined by EN ISO 9073-3. Most preferably, the tensile strength is between 150 and 350 N / 5 cm, especially in machine and cross direction. Preferably, the tensile strength in machine direction is at least 200 N / 5 cm, preferably between 200 and 400 N / 5 cm. Such a tensile strength can be advantageous for handling and processing, because damages can be reduced, for example by cracks, punctures or detachment.

[0071] Preferably, the elongation at 50 N / 5 cm in machine direction is less than 10 %, preferably in the range of 2 % to 10 %, as determined by EN ISO 9073-3. Preferably, the elongation at 25 N / 5 cm in machine direction is less than 10 %, preferably between 0.5 % and 8 %. This can be advantageous, because the material is relatively rigid when higher forces are exerted.

[0072] In a preferred embodiment, the peel strength or peel adhesion of the composite material on a metal surface, after consolidation of the second adhesive, is between 10 and 50 N / 25 mm, more preferably between 20 and 40 N / 25 mm, as determined by a peel strength test according to FINAT 1 , No. 1 at 180°, or peel adhesion test according to FILC Int. 29. In the tests, specimen of the composite material can be attached to a stainless-steel panel.

[0073] Preferably, the peel strength and / or peel adhesion is essentially maintained after continued use, for example for at least one month, six months or one year. Preferably, it is reduced in such a time span by not more than 20%, preferably not more than 10%. The change of the peel strength can be monitored in an aging test, for example after repeated cycles of simulated summer conditions (80°C, relative humidity about 60 %, six hours) and winter conditions (20°C, relative humidity 45 %, six hours).

[0074] Preferably, the water absorption capacity of the composite material is between 200 and 2000 g / m2, more preferably between 400 and 2000 g / m2, as determined at 0° according to FILC, No. 19. Thus, although the thickness of the condensation control material is low, it can take up high amounts of water, thereby providing a strong condensation control effect.

[0075] The layers of the condensation control material comprise, in consecutive order, the laminate from nonwoven layer to the release liner. In a preferred embodiment, there are no further intermediate layers between the five layers. Preferably, the condensation control material consists of the five layers. This can be advantageous for simple use and production. However, it is also possible that at least one further layer is included, which confers a desired property to the composite material. For example, the additional layer can be a protective layer on top of the nonwoven layer, such as a net or scrim, for increasing the mechanical stability. Further, the composite material may comprise a firebarrier layer or insulation layer.

[0076] In a preferred embodiment, the composite material, and preferably the nonwoven layer, comprises additives and / or functional fibers, which confer a desired function to the composite material. For example, the nonwoven layer may comprise an antimicrobial agent. For example, the functional fibers can be fire-retardant fibers, hollow fibers and / or fibers having a different shape or cross-section than the main fiber.

[0077] Subject of the invention is also a building and / or building part, comprising an inventive condensation control material, which covers an interior surface of the building and / or building part. Since the material has been attached, it does not comprise the release liner, which is removed before assembly. The building part is an integral part of the building.

[0078] Preferably, the peel strength of the condensation control material to the interior surface of the building and / or building part is between 10 and 50 N / 25 mm, as determined by the test according to Fl NAT no. 1 at 25°C at 180°. Therefore, the peel strength is in a range such that the condensation control material can be detached manually, preferably by peeling it off.

[0079] The inventive condensation control material can be used in the inventive method, as outlined above. If desired, the inventive condensation control material can also be applied manually to a discrete building part before integration into the building. For example, this may be practical, if the building part is new, or if it is dismantled for other purposes such as repair, or if the building surface is not accessible. However, after the building part becomes part of the building, it is generally not required to dismantle it for applying the inventive condensation control material.

[0080] Subject of the invention is also a method for preparing the inventive condensation control condensation control material, comprising the steps of

[0081] (i) coating the nonwoven layer and / or reinforcement layer with the first adhesive,

[0082] (ii) attaching the reinforcement layer to the nonwoven layer by the first adhesive and consolidating the first adhesive,

[0083] (iii) applying the second adhesive on the other surface of the reinforcement layer, and

[0084] (iv) applying the release liner over the second adhesive.

[0085] Accordingly, it is preferred to provide at first an intermediate product in the form of a laminate from the nonwoven layer, first adhesive layer and reinforcement layer. Subsequently, the second adhesive layer can be applied on top of the reinforcement layer and covered with the release liner.

[0086] Subject of the invention is also the use of the inventive condensation control material for controlling condensation in a building. Preferably, the use comprises covering an interior surface of the building, especially an uninsulated metal surface, preferably a roof.

[0087] Exemplified embodiments of the invention and aspects of the invention are shown in the figures. Figure 1 shows schematically and in exemplified form a condensation control material (6) of the invention. The first adhesive layer 2 bonds reinforcement layer 3 to nonwoven layer 1. The second adhesive layer 4 is for bonding the stable assembly of layers 1 to 3 to a building surface. Release liner 5 protects the second adhesive layer 4, and is peeled off and discarded, before the condensation control material 6 is applied to a surface. The remaining composite material from layers 1 to 4 is laid manually onto the building surface. To provide an intimate and uniform connection, pressure can be applied on the upper side of the composite, which is formed by nonwoven layer 1. The product is an interior building surface with a strong and durable condensation control cover. The inventive condensation control material and method solve the problem underlying the invention. They provide numerous advantages compared to conventional condensation control materials from a nonwoven layer and an adhesive layer for attachment to the surface, which is protected by a release liner. Such conventional materials are applied by machinery to dismantled, flat metal parts. A comparison of properties is shown in table 1.

[0088] Table 1: comparison of inventive material to conventional material Examples

[0089] Example 1: Preparation of condensation control material

[0090] The condensation control material was prepared as outlined in the following. The nonwoven layer was a needle-punched nonwoven consisting of 100% polyester (PET) staple fibres having a basis weight of 110 g / m2. In the first lamination step, the nonwoven layer is coated with the first adhesive (15 g / m2, styrene-butadiene rubber). Subsequently, a corona-treated HDPE / LDPE foil is applied over this first adhesive layer as reinforcement layer. The product from the first step is coated on the foil layer with the second adhesive, which is a pressure sensitive adhesive based (30 g / m2, styrene-butadiene rubber, with stabilizer). Subsequently, one-side siliconized LDPE foil is applied over this second adhesive layer as the release liner.

[0091] After peeling off the release liner, the composite can be adhered onto the substrate surface by the second adhesive layer. Thereby, the condensation control composite of the invention is obtained. Further information about the layers is summarized in the following.

[0092] Reinforcement layer

[0093] The reinforcement layer is a plastic foil from LDPE (Low Density Polyethylene) and HDPE (High Density Polyethylene) having the following properties:

[0094] Release liner:

[0095] The release liner is a foil from LDPE and HDPE which is siliconized on one side with UV cross-linking silicone compound, thickness 55 pm.

[0096] Example 2: Mechanical properties

[0097] The mechanical properties of the condensation control material of example 1 without release liner were examined according to DIN ISO 9073 from 2022. Elongation was determined according to option B with test specimen having a width of 5 cm, wherein the constant rate of extension was set to 200 mm / min. For comparison, the properties of a conventional condensation control composite (DRIPSTOP™, Freudenberg, DE) were also examined. The comparative product from 3 layers is provided for attachment to flat building parts by machinery, followed by profiling and integration into the building. The results are summarized in table 2. Table 2: Mechanical properties of inventive condensation control material and comparative product Example 3: Properties of condensation control material bonded to metal substrate

[0098] The composite condensation control material of example 1, without the release liner, was adhered to a metal plate. The properties of the metal-bonded condensation control material were examined by various test methods.

[0099] Peel adhesion test

[0100] Peel adhesion is tested according to FILC INT. 29 (method final no. 1-180°). SAMPLE PREPARING - NUMBER AND SIZE OF SAMPLES

[0101] At least three samples are cut out in longitudinal direction. The sample sizes are:

[0102] • metal plate (stainless steel panels with a mirror-like surface produced by

[0103] Rocholl): 35 x 225 x 1 mm

[0104] • testing material: 25 x 250 mm TEST CONDITIONS - PROCEDURE

[0105] The testing material are fastened to the plate in the way that 100 mm are glued on the plate by light pressure of fingers. The glued material is rolled four times (two times in each directions) with standard FINAT roller (weight of 2kg).

[0106] Samples were tested as follows:

[0107] A) Testing after 20 minutes

[0108] B) Testing after 24 hours

[0109] The test is done on the Zwick dynamometer under the following conditions:

[0110] The metal plate is inserted into the lower clamp, while the free part of the testing material must be turned up and inserted into the upper clamp.

[0111] Distance between clamps: 230 mm

[0112] Preloading: 0 N

[0113] Preceding path: 5 mm

[0114] Testing path: 100 mm

[0115] Testing speed: 300 mm / min

[0116] Peel adhesion after ageing - Ageing of self-adhesive products (based on Fl NAT no.1 - 180°)

[0117] SAMPLE PREPARING - NUMBER AND SIZE OF SAMPLES

[0118] At least three samples are cut out in the longitudinal direction. Sample sizes are:

[0119] • metal plate (stainless steel panels with a mirror-like surface produced by

[0120] Rocholl): 35 x 225 x 1 mm

[0121] • testing material: 25 x 250 mm

[0122] AGEING test

[0123] The product is aged in the temperature climatic chamber (Feutron). Regarding the ageing duration, the chamber is set on the chosen number of cycles / repetitions, usually 8 weeks. One cycle is usually defined under the following conditions:

[0124] • »summer conditions®: 80°C, relative humidity 57-60% - 6 hours

[0125] • »winter conditions®: - 20°C, relative humidity 45% - 6 hours Each ageing test contains a defined number of cycles. After the test, the samples are taken out of the chamber and air-conditioned for 24 hours at room temperature. The separation strength of the samples is also measured before ageing. When a comparative ageing test is done, the different self-adhesive products are tested all at once and the results are compared after a defined time of ageing. All tests are performed in the same way. The samples are taken out during the summer or winter conditions and before testing they must have the same air-condition period.

[0126] TEST CONDITIONS - PROCEDURE are the same as outlined above for the peel adhesion test.

[0127] Measuring water absorption depending on roof slope

[0128] The method measures the water absorption depending on the roof slope. The method itself is a combination of the method used by Fraunhofer (Institut fur Bauphysik), DIN 53923, and method used by Danish Technological Institute.

[0129] PREPARING SAMPLES

[0130] For the test, metal plates with attached condensation control material of the size 140 x 120 mm were used. The metal plates are clean without any residuals of glue or oil instead. Metal plates were cleaned with 96% ethyl alcohol prior testing. On such a plate a 10 x 10 cm piece of condensation control material is glued. After that a »Finat« type roll of width 10 cm is rolled twice (once in each direction) over such a plate in order to press the materials together. Each plate is then weighted. The result is marked as Mi - dry sample weight. The test is performed at a slope of 0° for three samples.

[0131] TESTING PROCEDURE

[0132] The samples prepared were immersed in water for one hour. The depth of the water is two centimetres, the orientation of the samples is with the condensation control material facing upwards. Once the samples have been immersed the roller is used two times (once in each direction).

[0133] After one hour the samples are taken out of the water and put on the stand. The felt should not be in the direct contact with the stand. On this stand three samples are fixed horizontally. During this process, the felt is facing downwards. After 15 minutes the samples are weighted again. The result is marked as M2- wet sample mass.

[0134] The difference between wet and dry samples (M2- Mi) is calculated for each sample. The water absorption is the average of three samples. The calculation is: water absorption

[0135] M2= wet sample mass, Mi = dry sample mass

[0136] Results

[0137] The results of the above described tests are summarized in table 3. The results indicate that the bonding and properties of the condensation control material on the metal plate are not significantly affected by aging. There is no or only little deterioration after exposure to hot and cold conditions over long time periods. The water adsorption of the composite material is high when applied at different slopes.

[0138] Table 3: Properties of inventive condensation control material adhered to metal plate

[0139] Example 4: Preparation and testing of condensation control material with polypropylene foil A condensation control material was prepared as described above in example 1 with the following modifications: A polypropylene foil was used as the reinforcement layer instead of polyethylene foil. The first adhesive layer with the weight of 30 g / m2was coated on the foil instead of the nonwoven. In the second step, adhesive is applied to release liner instead of polypropylene foil from the first step.

[0140] The plastic foil from polypropylene had the following properties:

[0141] The mechanical properties of the condensation control material were tested as outlined above for example 2. The properties of the condensation control material bonded to metal substrate were tested as outlined above for example 3. The adhesion after ageing was determined after 7 weeks. The results are shown in table 4 below.

[0142] Table 4: Properties of inventive condensation control material of example 4 The polypropylene foil as reinforcement layer increases internal stability of the condensation control material. The results indicate that the bonding and properties of the condensation control material on the metal plate are not significantly affected by aging. There is no or only little deterioration after exposure to hot and cold conditions over long time periods. The water adsorption of the composite material is high when applied at different slopes.

Claims

CLAIMS1. A method for controlling condensation in a building, comprising the steps(a) providing a condensation control material (6) which comprises in consecutive order:- a nonwoven layer (1),- a first adhesive layer (2),- a reinforcement layer (3),- a second adhesive layer (4), and- a release liner (5),(b) removing the release liner (5) from the condensation control material, and(c) manually attaching the condensation control material (6), via second adhesive layer (4), to an interior surface of the building, wherein the elongation of the condensation control material (6) at 20 N / 5 cm is between 0.5% and 10%, as determined by EN ISO 9073-3.

2. The method of at least one of the preceding claims, wherein the interior surface of the building is a metal surface.

3. The method of at least one of the preceding claims, wherein the interior surface of the building is profiled.

4. The method of at least one of the preceding claims, wherein the interior surface of the building is a roof surface.

5. A condensation control material (6), which comprises in consecutive order:- a nonwoven layer (1),- a first adhesive layer (2),- a reinforcement layer (3), which is bonded to nonwoven layer (1) by the adhesive layer (2),- a second adhesive layer (4), and- a release liner (5), which covers the second adhesive layer (4), wherein the elongation of the condensation control material (6) at 20 N / 5 cm is between 0.5% and 10%, as determined by EN ISO 9073-3.

6. The condensation control material of claim 5, wherein the basis weight of the nonwoven layer (1) is in the range from 20 to 500 g / m2.

7. The condensation control material of at least one of claims 5 to 6, wherein the nonwoven layer (1) comprises polyester fibers.

8. The condensation control material of at least one of claims 5 to 7, wherein the reinforcement layer (3) is a plastic foil.

9. The condensation control material of claim 8, wherein the plastic of the plastic foil is polyethylene or polypropylene.

10. The condensation control material of claim 8 and / or 9, wherein the thickness of the plastic foil is between 10 and 100 pm.

11. The condensation control material of at least one claims 5 to 10, wherein the first adhesive layer (2) is from hot-melt adhesive and / or the second adhesive layer (4) comprises a pressure sensitive adhesive.

12. The condensation control material of at least one claims 5 to 11, which has a basis weight between 100 and 700 g / m2, as determined without release liner.

13. A building and / or building part comprising a condensation control material (6) of at least one of claims 5 to 12, without release liner (5), wherein the condensation control material (6) covers an interior surface of the building or building part.

14. A method for preparing a condensation control material of any of claims 5 to 12, comprising the steps of(i) coating the nonwoven layer and / or reinforcement layer with the first adhesive,(ii) attaching the reinforcement layer to the nonwoven layer by the first adhesive and consolidating the first adhesive,(iii) applying the second adhesive on the other surface of the reinforcement layer (3), and(iv) applying the release liner (5) over the second adhesive.

15. The use of a condensation control material (6) of at least one of claims 5 to 12 for controlling condensation in a building.