WO1996037668A1

WO1996037668A1 - Air barrier and use thereof in roofs

Info

Publication number: WO1996037668A1
Application number: PCT/EP1996/002028
Authority: WO
Inventors: Henricus Joannes Maria Van De Ven; Eugeniusz Maderek; Jozef Christiaan Wilhelmus Spijkers
Original assignee: Akzo Nobel N.V.
Priority date: 1995-05-22
Filing date: 1996-05-11
Publication date: 1996-11-28
Also published as: AU5895396A

Abstract

The invention concerns an air barrier to be installed in roofs in order to prevent heat convection losses and improve the room climate. The air barrier is a laminate with at least one non-porous, watertight functional layer which is permeable to water vapour. The functional layer contains copolyetherester, polyurethane and/or copolyetheramide-based polymers. The invention also concerns a process for producing heat-insulated roofs of the ventilated and non-ventilated types for preventing heat convection losses.

Description

Air lock and use of the same in roofs

* * *

Description:

The invention relates to an air barrier for installation in roofs to prevent heat convection losses and to improve the indoor climate, which is a laminate with at least one non-porous, watertight, water vapor-permeable functional layer, the use thereof in roofs and a method for producing heat-insulated, heat con roofs avoiding vection loss.

The structural thermal insulation of residential buildings can be significantly improved in that the roofs are provided with heat-insulating material. As a result, the amount of heat lost through the envelope of a building (transmission heat loss) can be significantly reduced. In order to also prevent the loss of convection heat, which is caused, for example, by joints, gaps, openings and cracks in the formwork of the roof, it is required that the heat-transferring surrounding surface of a building must be permanently impermeable to air. Usually, waterproof, fiber-reinforced or unreinforced polyolefin or aluminum foils are usually applied on the room side, which shut off any natural water vapor transport and give the hermetically sealed living space the typical so-called plastic bag image. If the attic is expanded as living space due to the now much more intensive use of buildings, the spaced attachment of a mostly wooden inner formwork to the air barrier or so-called vapor barrier takes place. The air barrier can be located above and / or below the rafters or the thermal insulation layer. It can now be seen that the internal formwork, which is designed as wood paneling or wood paneling, is exposed to a high level of atmospheric humidity, especially in warm air. This means that there is a risk of infestation of the wood with fungi such as blue mold sponge formation, especially on cold bridges; a circumstance which obviously leads to health impairment of the users of the roof space.

It proves disadvantageous here that the wood absorbs moisture, changes in volume occur and forms such an excellent breeding ground for fungi and bacteria that it is necessary to subject the wood to chemical treatment. It turns out that despite the chemical treatment of the wood, in particular the blue mold sponge formation cannot be completely avoided, since despite thermal insulation, condensation of the warm air enriched with water vapor in wood areas which have lower temperatures via cold bridges, i.e. e.g. on outer wall ceilings, cannot be prevented; consequently, the occurrence of fungal attack can adversely affect the health of the users of the roof space.

Those that can consist of organic and / or inorganic insulation materials are used as the insulation layer. Glass, stone, slag wool in the form of mat-like fabric or felt are suitable as inorganic fibrous insulation materials. These are characterized by low weight, high thermal insulation, sound-absorbing properties, non-combustibility, resistance to putrefaction and the ability to due to their porosity and fibrousness absorb moisture on the inside and release it again on the outside. However, the rock wool used as a thermal insulation layer has the disadvantage of dust or fragments trickling out due to the aging process and the permanent thermal-mechanical stress.

For example, DE-OS 42 01 353 discloses an insulating formwork for roofs and walls, which is covered with surfaces of formwork elements lying next to one another with layers applied on the inside or outside, as well as insulation layers arranged in the formwork elements, the formwork elements having recesses on at least one side which are covered with a barrier layer. However, due to the use of natural raw materials, in particular wood or materials related to the wood, this insulating formwork is subject to an aging process and, in order to prevent fungal and mold infestation, must be treated with the unwanted impregnating and protecting agents in house construction.

Air barriers are usually air-impermeable plastic films which are arranged on the cold roof on the side of the thermal insulation layer facing the top floor apartment and are attached to the or below the spar by means of slats. The ceiling formwork is attached to the slats.

Air locks on warm roofs are mostly laid on the side of the thermal insulation layer facing the top floor apartment and can be covered by means of roof formwork coupled to rafters towards the top floor apartment.

In the present description, the outside is to be equated with the side facing away from the top floor apartment, for example the rafters, and inside is to be equated with the side facing the top floor apartment, for example the rafters. The loss of moisture is exacerbated by the fact that today, for reasons of energy saving, heating is often less and more uneven, so that strong condensation can be found in cold and cooled rooms, since a colder room air is more quickly saturated with water vapor and thus absorb less moisture can

In addition, the interior air in the attic apartments provided with chemically treated wood is strongly enriched with the fungicides and insecticides diffusing out of the wood, so that the user is forced to ventilate frequently in order to avoid health problems due to the high concentrations of pollutants in the room air , a circumstance that increases heating costs inappropriately.

In order to eliminate the disadvantages mentioned above, US Pat. No. 4,684,568 proposes the use of a water-vapor-permeable, waterproof film, a polypropylene resin being applied to the surface of a fabric layer, so that the fabric layer becomes water- and vapor-impermeable. Subsequent calendering produces the water vapor permeability of the film while maintaining the water tightness. This prior art completely overlooks the fact that the water-vapor-permeable layer should not only be water-vapor-permeable and watertight, but also because of the high mechanical and thermal loading of the film in the roof area, it must additionally have a high tear strength and a high melting point, so that the Back pressure and suction forces caused by wind, especially in the case of cold roofs, do not lead to crack formation and fatigue of the film for a long time. In addition, the prior art completely overlooks the fact that the lower the inclination of a roof, the greater the requirements for the thermal resistance and durability of the water vapor permeability of the film, even in inhospitable weather such as frost and driving rain. The trouble will be not recognized by this state of the art, let alone solved.

The invention is therefore based on the object of providing an air lock for installation in roofs which has the above-mentioned. Does not have disadvantages of the prior art. In addition, it should be possible for the air barrier to offer protection against the trickling of components of the thermal insulation layer and to ensure sufficient tear resistance against wind suction and wind pressure, without losing the ability to be water vapor permeable and watertight.

Since pitched roofs are generally cheaper and cheaper to maintain than flat roofs, the use of the cover in large-scale wet buildings in agriculture should also be used, e.g. be possible in animal stalls without sagging between large rafter distances due to insufficient tensile strength, as has been observed up to now with conventional covers.

The object is achieved by the air barrier according to the invention for installation in roofs to prevent heat convection losses and to improve the indoor climate, which is a laminate with at least one non-porous, waterproof, water vapor-permeable functional layer, which is characterized in that the functional layer is based on copolyether ester-based polymers, Contains polyurethane base and / or copolyether amide base.

Another object of the invention is the use of the air barrier according to the invention in ventilated or unventilated pitched roofs.

Another object of the invention relates to the method for producing a heat-insulated roof which avoids heat convection loss and which is characterized in that the air barrier according to the invention is located on the roof Attic apartment facing side of the thermal insulation layer or rafters, is relocated.

It can be observed that the air barrier according to the invention as a vapor retardant wind barrier which is optimized in terms of building physiology, owing to its sufficient water vapor permeability of more than 2000 g / m 2 with a 10 m functional layer (modified 24 hours according to ASTM E 96-66), the passage of air humidity, in particular at very warm room temperature from the interior to the outside is made possible in such an excellent manner that moisture precipitation can often be avoided, in particular on room enclosing surfaces with a low internal surface temperature, for example on outer wall ceilings or corners. On the one hand, the water vapor transport capacity is so high that the air barrier meets the requirements for living comfort, on the other hand, it is certain that there will be no undesired condensation in the thermal insulation layer.

The chemical treatment of the wood paneling of the interior with fungicides and pesticides, which is conventionally to be carried out on warm roofs, is also omitted in this connection, because the moist nutrient medium is also removed from the fungi and bacteria due to the rapid passage of water vapor through the air barrier according to the invention. It should not be forgotten that there is thermal insulation which, if it e.g. are porous, are very well able to absorb the moisture diffused from the interior through the air barrier and release it to the outside.

Laminate means both a single-layer film and an at least two-layer or multilayer film. The air barrier according to the invention can be designed as a single-layer laminate, two-layer or multi-layer laminate, the single-layer laminate as a film consisting only of the functional layer. Likewise, when brittle thermal insulation materials are used, the trickling of dust and larger fragments caused by the natural brittleness of the material and their penetration into the living area of the attic apartment are sufficiently avoided, so that there is no health impairment due to inhalation.

The embodiment of the air barrier according to the invention in which the functional layer comprises a film or a film which can be produced with copolyether ester-based polymers is advantageous. The functional layer can also comprise a fleece, a felt, a knitted fabric and / or a fabric as a support layer, which is thread or lattice reinforced by means of threads or ribbons. The fleece, the felt, the knitted fabric and / or the fabric can be partially or completely impregnated and / or coated with the copolyetherester-based, polyurethane-based and / or copolyetheramide-based polymers by extrusion coating.

In the case of extrusion coating, the coating composition, which contains the copolyetherester-based, polyurethane-based and / or copolyetheramide-based polymers, is introduced as granules into an extruder, heated, melted and pressed through a slot die. The resulting molten web is immediately after leaving the slot die on the e.g. Fleece, which can be warmed, pressed on and smoothed with the aid of pairs of rollers.

In an advantageous embodiment of the subject matter of the invention, a water vapor-permeable support layer can be applied to at least one side of the functional layer, the water vapor-permeable support layer preferably being porous. It turns out that the support layer protects the functional layer from the mechanical damage which may occur when the air barrier is installed by the craftsmen. The support layer can also be a lattice and / or thread reinforced water vapor permeable foam layer.

It is advantageous if the support layer is a fleece, felt, foam and / or fabric, which can be made of natural fibers or man-made fibers. All possible naturally occurring materials such as cotton, linen jute, hemp and / or sisal are suitable as natural fibers. The synthetic fibers, such as polyester, polyamide, polyacrylic, polyvinyl chloride fibers or mixtures thereof, as well as regenerated and / or modified cellulose fibers have proven to be particularly suitable as chemical fibers.

By arranging a support layer produced with synthetic chemical fibers on the functional layer, it is possible to use the air barrier according to the invention in agricultural wet farms such as cowshed and pig stables, because firstly larger rafter distances are provided with the air barrier according to the invention without further support and, secondly, man-made fibers generally do not provide a breeding ground for the fungi and sponges that are frequently found in animal houses.

It turns out that the support layer can have a weight per unit area of 5 to 1000 g / m2, preferably 50 to 250 g / m2. It is possible to glue the functional layer to the support layer in the form of a point, grid, labyrinth, island or strip.

The support layer can also be a water vapor permeable, preferably porous insulation layer, for example a temperature and / or sound-insulating layer, with organic and / or inorganic insulating materials, preferably glass fibers, rock or mineral fibers, slag fibers and / or ceramic fibers. An insulation layer is to be understood as a layer which is permeable to water vapor. In addition, the air barrier according to the invention can have a water vapor permeable, preferably porous insulation layer which is applied to at least one side of the functional layer and / or on the side of the support layer facing away from the functional layer. The insulation layer can be designed as a temperature and / or soundproofing.

As organic porous insulation materials, those made of cork are preferred. Organic fibrous insulation materials such as wood wool, bitumen felt and / or bitumen cork felt are suitable because of their good processability, sound and heat insulating properties and weather resistance.

The support layer made of mineral fibers has a bulk density of 25 to 200 kg / m3, glass wool 14 to 100 kg / m3, polystyrene foam 15 to 60 kg / m3, polyurethane foam at least 15 kg / m3, cork boards from 80 to 200 kg / m3, made of wood wool from 360 to 570 kg / m3 (measured according to DIN 18 161). Furthermore, the support layer can have a thread-reinforced, lattice-reinforced structure with the formation of bands or strips of textile material.

In addition, a fleece, felt, fabric and / or knitted fabric layer can be arranged between the insulation layer of the functional layer, which is permeable to moisture parallel to the functional layer and perpendicular to the surface of the functional layer, so that the moisture after permeating through the functional layer evenly distributed within the fleece, felt, fabric and / or hosiery layer before it passes through the insulation layer, which at least facilitates uniform moisture penetration through the insulation layer.

It is advantageous if the functional layer has a layer thickness of 10 to 1000 m, preferably 100 to 200 m, even more preferably 50 to 100 m. For example, if If the air barrier according to the invention is used as a single-layer laminate, a layer thickness of the laminate of 50 to 100 m is advantageous, but if it is used as a multilayer film, a layer thickness of the functional layer of 10 to 25 m is particularly advantageous.

The air barrier according to the invention can be designed in the form of a sheet, sheet or plate. The sheet-like or web-shaped air barrier can be rolled up, easily transported as rolls, and is characterized by a pleasant, uncomplicated, uncomplicated handling that is caused by quick and easy unrolling on roofs. The air barrier according to the invention can have a layer thickness of 40 to 1000 m, preferably 50 to 500 m, more preferably 80 to 100 m.

In one embodiment of the air barrier according to the invention, the polymers can be copolyether esters which are derived from longer-chain polyglycols, short-chain glycols with 2 to 4 carbon atoms and dicarboxylic acids, the polymers preferably being copolyether esters which consist of a multiplicity of recurring intralinear long-chain and short-chain ester units , which are linked head to tail statistically via ester linkages, the long-chain ester units of the formula

- 0 - G - 0 - C - R - C -

and the short chain ester units of the formula

0 0

- 0 - D - 0 - C - R - C - correspond, in which G represents a divalent radical which remains after the removal of terminal hydroxyl groups from at least one long-chain glycol with an average molecular weight of 600 to 6000 and an atomic ratio of carbon to oxygen between 2.0 and 4.3, at least 20% by weight of the long-chain glycol have an atomic ratio of carbon to oxygen between 2.0 and 2.4 and make up 15 to 50% by weight of the copolyetherester, R represents a divalent radical which, after removal of carboxyl groups from at least one Dicarboxylic acid of a molecular weight of less than 300 remains, and D represents a divalent radical which remains after the removal of hydroxyl groups from at least one diol of a molecular weight of less than 250, with at least 80 mol% of the dicarboxylic acid used from terephthalic acid or its ester-forming equivalents and at least 80 mol% of the diol with d A small molecular weight consists of 1,4-butanediol or its ester-forming equivalents, the sum of the molar percentages of dicarboxylic acid which is not terephthalic acid or its ester-forming equivalents and the diol with a low molecular weight which is not 1,4-butanediol or its ester-forming equivalents represents at most 20% and the short-chain ester units are 40-80% by weight of the copolyetherester.

The air barrier in which the polymers are wholly or partially copolyether esters, in which at least 70 mol% of the dicarboxylic acid used is 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents and in which at least 70 mol.% Is particularly preferred of the diol used with a small molecular weight is 1,4-butanediol or its ester-forming equivalents and the sum of the molar percentages of the dicarboxylic acid which is not 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents and of the diol with a small molecular weight which is no 1,4-butanediol or its ester-forming equivalents, at most 30% is and the ester units with short chains make up 35 to 80% by weight of the copolyetherester.

In addition, the polymers can be copolyether esters, in which the consist of a multiplicity of recurring intralinear long-chain and short-chain ester units, which are linked statistically via ester bonds head to tail, the long-chain ester units of the formula

- 0 - G - O - C - R - C -

and the short chain ester units of the formula

0 0

- 0 - D - O - C - R - C -

correspond, where G represents a divalent radical which, after removal of terminal hydroxyl groups from at least one long-chain glycol, has an average molecular weight of 600 to 4,000 and an atomic ratio of carbon to oxygen of between 2 and 4.3, at least 20% by weight .% of the long-chain glycol have an atomic ratio of carbon to oxygen between 2.0 and 2.4 and make up 15 to 50% by weight of the copolyetherester, R represents a divalent radical which, after the removal of carboxyl groups from at least one dicarboxylic acid, is one Molecular weight of less than 300 remains and D represents a divalent radical which remains after the removal of hydroxyl groups from at least one diol with a molecular weight of less than 250, at least 70 mol% of the dicarboxylic acid used being 2,6-naphthalenedicarboxylic acid or its ester-forming Equivalents exist and at least 70 mol% d es diols with the small molecular weight from 1,4 butanediol or its ester-forming equivalents and the sum of the mol% of the dicarboxylic acid, which is not 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents, and of the diol with a small molecular weight, which is not 1,4-butanediol or its ester-forming equivalents, is maximum is at least 30% and the ester units with short chains are 35 to 80% by weight of the copolyetherester.

Apart from the ventilation of the top floor apartment necessary for gas exchange, the use of the non-porous, water vapor permeable, waterproof functional layer made of copolyetherester polymers means that there is no longer any need to ventilate the premises because the moisture can diffuse outward through the functional layer to a high degree . This also eliminates for the user the idea of life in hermetically sealed living spaces, namely the plastic bag type, which is usually conveyed when using conventional air-impermeable foils.

In addition, the wooden cladding of the interior of the attic apartment, which is to be treated with wax or oil or chemically impregnated, no longer, at least to a very limited extent, conveys a pleasant feeling of wellbeing and well-being as well as an excellent indoor and indoor climate, because not only no or insignificant concentrations of pollutants are present in the room air, but also because the sticky, humid, humid room air that occurs when using conventional air barriers is not to be found, so that frequent ventilation is unnecessary for this reason.

The air barrier according to the invention is also distinguished by high environmental compatibility. The polytetrafluoroethylene frequently used as a functional layer of covers, as disclosed in US Pat. No. 4,452,848, is distinguished in the case of domestic fires by the formation of partially highly toxic halogen compounds, such as fluorine-containing decomposition products. Fluorophosgene, carbonyl fluoride, tetrafluoroethylene, perfluoroisobutylene, hydrogen fluoride, trifluoroacetyl fluoride or perfluorisobutene, which not only increases the risk of smoke poisoning of the residents but also makes extinguishing house fires very difficult for the extinguishing personnel. In contrast, the air barrier according to the invention proves to be essentially free of harmful halogen compounds in the event of fire.

Due to the high water vapor permeability of the functional layer of the air barrier according to the invention, the use of approximately constructionally damp or freshly cut wood is also readily possible both when used in the interior cladding of the attic apartment, since constant dehumidification is made possible even in colder areas such as outside wall corners.

In addition, the use of the air barrier according to the invention in ventilated or non-ventilated flat roofs is outstandingly suitable, which has at least one non-porous, waterproof, water vapor-permeable functional layer which contains copolyether ester-based, polyurethane-based and / or copolyether amide-based polymers.

The air barrier according to the invention can also be used wherever additional measures to prevent wetting occur. Convective heat losses in the rooms in the event of leaks in the heat-transferring surrounding area and condensation damage due to joints, gaps, cracks or holes are avoided, since the air barrier according to the invention is completely airtight (according to DIN 53 887) and windproof. In addition, no water in liquid form passes through the air barrier according to the invention because of the lack of water penetration (with a single air barrier: at least 1 bar = 10 m water column; multilayer air barrier: >> 1 bar = 10 m water column ASTM D-751 (Mullen test)).

In the method according to the invention for producing a heat-insulated roof of the ventilated type which avoids heat convection loss, the air barrier according to the invention can be laid on the side of the thermal insulation layer or rafters facing the top floor apartment, the air barrier preferably being designed as a single-layer laminate, which is the non-porous film , comprises a waterproof, water vapor permeable functional layer which contains copolyether ester-based, polyurethane-based and / or copolyether amide-based polymers.

It also shows that, despite its quite high moisture content, freshly built timber can be installed in attics without the risk that the moisture escaping from the wood during slow drying will build up on cold bridges on the roof structure of e.g. Warm roofs knocked down.

Another object of the invention relates to a method for producing a heat-insulated roof of the non-ventilated type which avoids heat convection loss, which is characterized in that the air barrier according to the invention is laid on the side of the thermal insulation layer facing the top floor apartment. In this case, the air barrier according to the invention can be designed as a film made of the non-porous, watertight, water vapor-permeable functional layer or as a film with at least one non-porous, watertight, water vapor-permeable functional layer on the support layer, which contains copolyetherester-based, polyurethane-based and / or copolyetheramide-based polymers. Because of the above-mentioned balanced properties of the air barrier according to the invention, it is advantageous to use it in rafters, throat beams, purlin roofs, explosive works, hanging works and free-stretched binders. Exemplary embodiment A web-like two-layer air barrier made of a film which contains copolyether esters as a polymer, which are derived from longer-chain polyglycols, short-chain glycols with 2 to 4 carbon atoms and dicarboxylic acids, is made from a rock wool layer on the side of the thermal insulation layer made of rock wool layers facing the attic apartment arranged that the overlaps of the web-shaped air barrier is approximately 20 to 25 cm. The overlaps are glued on one side with an adhesive tape over the entire layer. The layer thickness of the air barrier is 0.4 mm. The air barrier is attached to the rafters using slats. A wooden wall made of spruce wood is then applied and serves as the interior wall and ceiling.

It can be seen here that the high air humidity of more than 75% in the attic apartment, which is caused by air humidifiers for a short time, quickly decreases to between 35 to 65%, which is tolerable and homely for humans, and the formation of blue mold and sponge during the test series in particular do not occur on cold bridges, particularly in the area of the lower, cool corners of the rooms. The results show that - apart from the ventilation of the attic apartment necessary for gas exchange - the necessary regular dehumidification of the premises is unnecessary due to the heat-lossy opening of the windows. Even if the thermal insulation layer made of stone wool is used, the trickling out of dust and fragments into the living area is eliminated.

Claims

Air lock and use of the same in roofs * * * Claims:

1. Air barrier for installation in roofs to prevent heat convection losses and to improve the indoor climate, which is a laminate with at least one non-porous, waterproof, water vapor-permeable functional layer, characterized in that the functional layer is based on copolyether ester-based polymers, a polyurethane base and / or copolyether amide base.

2. Air lock according to claim 1, characterized in that the functional layer is a film, a film and / or ei¬ ne, preferably thread or lattice reinforced, support layer, preferably a fleece, a felt, a knitted fabric and / or a fabric, includes.

3. Air barrier according to claim 2, characterized in that the support layer is impregnated with the polymers and / or be¬ coated.

4. Air lock according to one of claims 2 to 3, characterized ge indicates that the functional layer is glued to the support layer point, lattice, labyrinth, island and / or strip-shaped. 18th

5. Air lock according to one of claims 2 to 4, characterized ge indicates that the support layer is permeable to water vapor, preferably porous.

6. Air barrier according to one of claims 2 to 5, characterized in that the fleece, the felt and / or the fabric contains natural fibers and / or man-made fibers.

7. Air barrier according to claim 6, characterized in that the natural fibers have cotton, linen, jute, hemp and / or sisal.

8. Air barrier according to claim 6 or 7, characterized gekennzeich¬ net that the chemical fibers have synthetic fibers.

9. Air barrier according to claim 8, characterized in that the chemical fibers have regenerated and / or modified cellulose fibers and / or mineral fibers.

10. Air barrier according to claim 8 or 9, characterized gekennzeich¬ net that the synthetic fibers contain at least one Ver¬ representatives of the polyester, polyamide, polyacrylic, polyvinyl chloride fibers or mixtures of the same group.

11. Air barrier according to one of claims 2 to 10, characterized in that the support layer has a basis weight of 5 to 1000 g / m2, preferably from 50 to 250 g / m2.

12. Air lock according to one of claims 2 to 11, characterized in that the functional layer is adhesively bonded to the support layer.

13. Air barrier according to one of claims 2 to 12, characterized in that the support layer is a lattice and / or thread-reinforced water vapor permeable foam layer.

14. Air barrier according to one of claims 2 to 12, characterized in that the support layer is a water vapor permeable, preferably porous, insulation layer.

15. Air barrier according to one of claims 2 to 14, characterized in that is arranged on at least one side of the function layer and / or on the side of the support layer facing away from the functional layer.

16. Air lock according to claim 14 or 15, characterized gekenn¬ characterized in that a temperature and / or sound-insulating layer is used as the insulation layer.

17. Air barrier according to one of claims 14 to 16, characterized in that the insulation layer has organic and / or inorganic insulating materials, preferably glass fibers, rock fibers, slag fibers and / or ceramic fibers.

18. Air barrier according to claim 17, characterized in that the insulating materials are fibrous or porous.

19. Air lock according to one of claims 13 to 18, characterized in that a further fleece, felt and / or fabric layer is arranged between the insulation layer and the functional layer for moisture transport in a parallel and perpendicular direction to the surface of the functional layer.

20. Air barrier according to one of claims 1 to 19, characterized in that the air barrier as a single-layer laminate has a layer thickness of the functional layer of 40 to 1000 m, preferably from 50 to 100 m.

21. Air barrier according to one of claims 1 to 19, characterized in that the air barrier, as at least two-layer laminate, has a layer thickness of the functional layer of 5 to 100 m, preferably 10 to 25 m.

22. Air lock according to one of claims 1 to 21, characterized in that the air lock is designed in the form of a sheet, sheet or plate.

23. Air barrier according to one of claims 1 to 22, characterized in that the polymers are copolyether esters which are derived from longer-chain polyglycols, short-chain glycols with 2 to 4 carbon atoms and dicarboxylic acids.

24. Air lock according to one of claims 1 to 23, characterized in that the polymers are copolyether esters, which consist of a large number of recurring intralinear long-chain and short-chain ester units, which are linked statistically via ester linkages head to tail, the long-chain ester units being the formula

0 0

- 0 - G - O -C - R - C -

and the short chain ester units of the formula

- 0 - D - 0 - C - R - C -

correspond, in which G represents a divalent radical which, after the removal of terminal hydroxyl groups from at least one long-chain glycol, has a medium residue Molecular weight of 600 to 6000 and an atomic ratio of carbon to oxygen between 2.0 and 4.3 remains, at least 20% by weight of the long-chain glycol having an atomic ratio of carbon to oxygen between 2.0 and 2.4 and 15 to 50% by weight of the copolyetherester, R represents a divalent residue which remains after the removal of carboxyl groups from at least one dicarboxylic acid with a molecular weight of less than 300, and D represents a divalent residue which after removal of Hydroxyl groups from at least one diol of a molecular weight of less than 250 remain, with at least 80 mol% of the dicarboxylic acid used from terephthalic acid or its ester-forming equivalents and at least 80 mol% of the diol with the small molecular weight from 1,4-butanediol or its ester-forming equivalents exist, the sum of the molar percentages of the dicarboxylic acid, which no terephthalic acid o of which represents their ester-forming equivalents, and of the diol with a small molecular weight which is not 1,4-butanediol or its ester-forming equivalents, is at most 20% and the short-chain ester units are 40-80% by weight of the copolyetherester.

25. Air lock according to one of claims 1 to 24, characterized in that the polymers are wholly or partly copolyether esters, wherein at least 70 mol% of the dicarboxylic acid used is 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents and in which at least 70 mol.% of the diol used with a linear molecular weight is 1,4-butanediol or its ester-forming equivalents and the sum of the mol percent of dicarboxylic acid, which is not 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents, and of the diol with a small one Molecular weight that is not 1,4-butanediol or its ester-forming equivalents is at most 30% and that Make up ester units with short chains from 35 to 80% by weight of the copolyetherester.

26. Air lock according to one of claims 1 to 25, characterized in that the polymers are copolyether esters, wherein the consist of a large number of recurring intralinear long-chain and short-chain Esterein¬ units, which are linked head to tail statistically via ester linkages, the long-chain esters ¬ units of the formula

_ 0 - G - 0 - C - R - C -

and the short chain ester units of the formula

0 0

- 0 - D - O - C - R - C -

correspond, where G represents a divalent radical which, after removal of terminal hydroxyl groups from at least one long-chain glycol, has an average molecular weight of 600 to 4,000 and an atomic ratio of carbon to oxygen of between 2 and 4.3, at least 20% by weight of the long-chain glycol have an atomic ratio of carbon to oxygen between 2.0 and 2.4 and make up 15 to 50% by weight of the copolyetherester, R represents a divalent radical which, after the removal of carboxyl groups from at least one dicarboxylic acid, is one Molecular weight of less than 300 remains and D represents a divalent radical which remains after the removal of hydroxyl groups from at least one diol of a molecular weight of less than 250, wherein at least 70 mol% of the dicarboxylic acid used consists of 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents and at least 70 mol% of the diol with the small molecular weight consists of 1.4 butanediol or its ester-forming equivalents and the sum of the mol% of the dicarboxylic acid which is not 2,6-naphthalenedicarboxylic acid or its ester-forming equivalents and the diol with a small molecular weight which is not 1,4-butanediol or its ester-forming equivalents is at most 30% and the ester units with short chains are 35 to 80% by weight .% of the copolyetherester be¬.

27. Use of the air barrier according to one of claims 1 to 26 in flat roofs or pitched roofs of the ventilated or non-ventilated type.

28. A process for producing a heat-insulated roof of the ventilated type which avoids heat convection loss, characterized in that the air barrier according to one of claims 1 to 26 is laid with the side of the thermal insulation layer or rafters facing the attic apartment.

29. A method for producing a heat-insulated roof of the unventilated type which avoids heat convection loss, characterized in that the air lock according to one of claims 1 to 26 is laid on the side of the thermal insulation layer facing the top floor apartment.