DECOUPLING WEB

The invention relates to a decoupling web (1), in particular intended for use for a surface covering structure (2) which can be covered with covering elements, preferably tile coverings, having a carrier web (3) and a multiplicity of nubs (5) projecting from the carrier web plane (4), the carrier web (3) having as material a, preferably thermoplastic, plastic. According to the invention, it is provided that the carrier web (3) comprises as material a copolymer comprising ethylene and vinyl acetate, in particular a copolymer of ethylene and vinyl acetate, preferably ethylene-vinyl acetate (EVA), and/or consists thereof.

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Description

The invention relates to a decoupling web with a carrier web and a plurality of nubs projecting from the plane of the carrier web, the carrier web having as material a, preferably thermoplastic, plastic. The decoupling web is in particular intended for use for a surface covering structure which can be covered with covering elements, preferably for tile coverings.

The term “decoupling” is understood to mean the reduction of shear stresses and/or stress peaks between two layers arranged in a firm bond. Effective decoupling thus prevents shear stresses and/or stress peaks present in one of the layers from being transferred to the other layer of the composite structure and causing damage there.

Decoupling webs of the aforementioned type are used, for example, in the construction industry when laying floor covering elements, such as ceramic tiles, in particular for decoupling, sealing and/or for vapour pressure compensation. In this case, the decoupling webs are laid on an underground, in particular glued, and form the supporting surface for the floor covering elements. Tiles are laid in particular on young screed using the thin-bed method. If no decoupling membrane is laid between the tiled floor and the young screed, then in the event of shrinkage of the screed the tiles, in particular due to their low coefficient of expansion, could not follow the movement of the screed, so that shear stresses arise which could ultimately lead to detachment or even tearing of the tiles. Decoupling webs are also required when laying coverings on particularly critical undergrounds, such as old wooden floors. A decoupling web of the type mentioned above compensates for these shear stresses by deformation, which is why there is no need to fear damage to the composite structure. In most cases, decoupling membranes are made of foil-like plastic, i.e. a flexible plastic layer that deforms under the influence of external forces. The material is usually selected in such a way that it is low in emissions, especially with regard to pollutants.

On the side of the decoupling membrane facing away from the floor covering elements, a fleece is usually provided, which can be firmly bonded to the carrier web. The fleece can be arranged on an underground when the decoupling web is laid and can be bonded to the underground. An adhesive layer may therefore be provided between the underside of the decoupling membrane facing away from the covering elements and the underground.

Subsequently, a thin layer of tile adhesive, also known as adhesive mortar or bonding layer, is usually applied to the support plane of the decoupling web to fix the floor covering elements to the decoupling web. It is understood that instead of a tile adhesive, an equally suitable adhesive or fastening layer and/or material may ultimately be provided. In this regard, tile adhesives are usually combed with a toothed trowel or a toothed smoothing trowel and a different tile adhesive is used depending on the area of application and/or the underground. For example, a reactive resin adhesive, a cementitious thin-bed mortar, a casein tile adhesive or a dispersion adhesive is used as the tile adhesive.

After the tile adhesive has been applied to a decoupling web, the individual flooring elements and/or tiles are laid on the tile adhesive. During application, the tile adhesive penetrates into the depressions of the decoupling web and hardens.

With decoupling webs of this type, the connected floor covering elements are separated from the underground and mechanically decoupled. Due to the arrangement of the nubs transverse to the longitudinal direction and in the longitudinal direction of the carrier plate, channels result which extend over the entire carrier plate. These channels interact with the nubs in such a way that they absorb and compensate for mechanical stresses and, in particular, shear stresses. This stress on the flooring elements can be generated due to temperature and humidity influences and/or due to a weight load.

In the manufacture of such decoupling webs, a mould is used which has projections corresponding to the recesses and/or nubs. However, the demoulding of the moulding tool and the decoupling sheet is usually problematic. Furthermore, the decoupling web can easily be damaged during demolding, especially if the protrusions of the mold have sharp corners that cut into and/or tear the usually still soft decoupling web material. In practice, attempts are made to solve the latter problem by providing the corners of the tool projections with a radius.

The adhesive tensile strength of the nub membranes known in practice—without the use of additional layers—does not usually meet the requirements needed for the use of the decoupling web.

Tensile adhesion strength, sometimes also referred to as pull-off strength, is a characteristic value used to evaluate the adhesion and/or bonding of layers to surfaces, in particular of the tile adhesive to the decoupling web. The adhesive tensile strength can be determined by means of an adhesive tensile test.

It is now an object of the present invention to provide a decoupling web having improved adhesive tensile strength.

According to the invention, the aforementioned task is at least substantially solved in a decoupling web of the type mentioned above in that the carrier web comprises as material a copolymer comprising ethylene and vinyl acetate and/or consists thereof. Quite preferably, the copolymer comprising ethylene and vinyl acetate is formed as a copolymer of ethylene and vinyl acetate, preferably ethylene-vinyl acetate (EVA, EVAC).

It goes without saying that special features, characteristics, designs and embodiments as well as advantages or the like which are set out below—for the purpose of avoiding unnecessary repetition—in relation to only one aspect of the invention, naturally apply mutatis mutandis in relation to the other aspects of the invention without the need for express mention.

Furthermore, it goes without saying that in the following specification of values, numbers and ranges, the relevant specifications of values, numbers and ranges are not to be understood in a limiting manner; rather, it goes without saying for the person skilled in the art that, depending on the individual case or application, deviations from the specified ranges and/or specifications can be made without leaving the scope of the present invention.

In addition, it applies that all values or parameters or the like mentioned in the following can in principle be determined or determined with standardized or explicitly stated determination methods or with determination methods familiar to the skilled person in this field.

Furthermore, it goes without saying that all weight or quantity-related percentages are selected by the person skilled in the art in such a way that the total results in 100%.

Having said this, the present invention will be described in more detail below.

In particular, it is understood that the carrier web may also comprise the copolymer comprising ethylene and vinyl acetate, preferably EVAC, only “proportionally”. The material of the carrier web can also comprise another, preferably thermoplastic, plastic.

Furthermore, it is particularly understood that a plurality, in particular at least two, of further, preferably thermoplastic, plastic materials may also be provided.

According to the invention, it has been found, to the complete surprise of the skilled person, that the copolymer comprising ethylene and vinyl acetate can significantly improve the mechanical properties of the decoupling web compared to decoupling webs known from the prior art. Thus, on the one hand, a significantly better adhesion, preferably by up to 60%, can be achieved compared to decoupling webs known in practice. The adhesion is improved in particular to the fleece and/or to the tile adhesive. Moreover, the decoupling web is not only substantially more flexible, but also exhibits better decoupling properties than decoupling webs known in practice. Due to the flexibility, for example, the packaging, in particular into rolls, of the decoupling web can be made easier, which reduces the effort required for storing the decoupling web.

In particular, the improved adhesion of tile adhesive to the decoupling web can also improve the adhesive tensile strength of the entire decoupling web.

The term “ethylene vinyl acetate” (EVA, also known as EVAC) ultimately refers to a group of copolymers formed by the polymerization of ethylene and vinyl acetate. Despite the strong branching of the chain molecules, the structure of ethylene vinyl acetate is crystalline only in a few places. With a corresponding vinyl acetate content, the ethylene vinyl acetate can be partially crystalline and thermoplastic. A translucent formation of the ethylene vinyl acetate is also known. The density and other properties are particularly dependent on the vinyl acetate content (VAC). At a lower vinyl acetate content (VAC), the ethylene vinyl acetate is more translucent, tougher, more flexible and more dimensionally stable under heat compared to PE-LD. A higher vinyl acetate content reduces strength, stiffness and chemical resistance.

The copolymer according to the invention comprising ethylene and vinyl acetate exhibits a flexibility at least substantially similar to rubber and ultimately resembles soft polyvinyl chloride, in particular in its property profile. At the same time, however, tear and impact resistance as well as light transmission and, in particular, gloss increase.

According to the invention, it is preferred that the properties of the decoupling membrane with respect to waterproofing, vapour pressure compensation and good drying are further ensured. The decoupling membrane according to the invention is waterproof, enables good vapour pressure compensation and also good drying. The vapour pressure equalisation and the drying can also be improved by the fact that the channels extending over the decoupling web, which run between the adjacent studs, are connected to one another indirectly and/or directly for the entire nub web.

According to the invention, the decoupling effect is advantageously designed in such a way that, on the one hand, no cracks are formed in the surface of the covering facing away from the decoupling web and, on the other hand, possible cracks in the underground, which in particular only occur after the decoupling web has been laid, do not show in the tile adhesive layer and/or the covering elements. Consequently, an improved load distribution can be achieved by the addition of EVA according to the invention.

Furthermore, the decoupling web according to the invention enables a high winding capability, so that the decoupling web can be easily rolled up, preferably for transport. Furthermore, the decoupling web according to the invention can have a high torsional stiffness and/or a high torsional stiffness, so that the decoupling web cannot be kinked and/or twisted, in particular by 90°.

Furthermore, it was found in tests carried out that, in addition to its excellent decoupling properties, the decoupling web according to the invention also exhibits very good impact sound insulation. This effect is also the result of the addition of the copolymer comprising ethylene and vinyl acetate according to the invention.

In a particularly preferred embodiment of the present invention, the carrier web comprises at least one thermoplastic polymer and/or elastomer as a further material. In particular, the thermoplastic polymer and/or elastomer may be hard polyethylene (HDPE), polyethylene (PE) and/or polypropylene (PP). Accordingly, the material of the carrier web may comprise another thermoplastic polymer material in addition to the copolymer comprising ethylene and vinyl acetate. In particular, the copolymer comprising ethylene and vinyl acetate may be blended with the further material. Alternatively or additionally, it is possible according to the invention for the further material to have a mass fraction in the material of the carrier web of at least 20 wt. %, preferably between 30 wt. % to 99 wt. %, more preferably between 40 wt. % to 95 wt. %, further preferably between 50 wt. % to 80 wt. %.

In tests carried out, it has been found that by adding the copolymer containing ethylene and vinyl acetate to thermoplastic materials known in practice for the carrier web, the essential properties of the decoupling web, in particular the decoupling properties and the adhesive tensile strength, can be significantly improved, preferably by up to 50%.

Preferably, the copolymer comprising ethylene and vinyl acetate, in particular the ethylene-vinyl acetate (EVAC), has a mass fraction in the material of the carrier web of at least 5 wt. %, preferably between 10 wt. % and 80 wt. %, more preferably between 20 wt. % and 60 wt. %, and in particular at least substantially between 25 wt. % and 55 wt. %. Depending on the proportion of the copolymer comprising ethylene and vinyl acetate in the material of the carrier web, in particular in relation to the further thermoplastic material, the properties, in particular the adhesive tensile strength and/or the decoupling properties, of the decoupling web can be adjusted accordingly. Individual adaptation to the respective customer requirements and/or the properties intended for the respective use can then be readily possible.

Furthermore, in another preferred embodiment of the invention, it is provided that the copolymer comprising ethylene and vinyl acetate has a vinyl acetate content of at least 5%, preferably between 10% to 50%, more preferably between 12% to 40%, further preferably between 16% to 30%, and in particular at least substantially between 25% to 29% , in particular based on the copolymer comprising ethylene and vinyl acetate.

Depending on the proportion of vinyl acetate, the properties of the copolymer can be adjusted or varied accordingly, in particular depending on the respective customer requirements, use specifications or the like. Macroscopically, the modulus of elasticity of the material, in particular of the copolymer comprising ethylene and vinyl acetate, should decrease with an increasing proportion of vinyl acetate (VAC). At a vinyl acetate of about 40 to 70 wt. %, the copolymer comprising ethylene and vinyl acetate is largely amorphous, whereas at a vinyl acetate of below 30 to 40 wt. %, the copolymer comprising ethylene and vinyl acetate is semi-crystalline and thermoplastic. Preferably, it is provided that the copolymer comprising ethylene and vinyl acetate is thermoplastic, so that in particular the vinyl acetate content is below 40 wt. %, based on the copolymer comprising ethylene and vinyl acetate.

In experiments carried out, it has been found in the course of the invention that with a vinyl acetate content of 28%+/−2%, the properties of the overall decoupling web could be further improved as compared to other vinyl acetate contents. Moreover, the copolymer containing ethylene and vinyl acetate with a vinyl acetate content of 28% is not only inexpensive but also readily available, which greatly simplifies the production of the carrier web. The copolymer comprising ethylene and vinyl acetate, in particular ethylene-vinyl acetate, having a vinyl acetate of about 28% is also referred to as “EVA28”.

In addition, it has been found during the development of the invention that the decoupling properties and/or the adhesion, in particular the adhesive tensile strength, can be significantly improved by a multilayer structure of the carrier web compared to the decoupling webs known in the prior art. In this regard, a multilayer structure of the carrier web may comprise layers differing from one another with respect to adhesion, adhesive tensile strength, elasticity and/or elongation at break. Consequently, it is possible to selectively adjust the mechanical properties of the decoupling web by means of the layer structure of the carrier web, in particular as a function of individual customer requirements.

Preferably, the carrier web has an at least two-layer layer structure, wherein at least two layers (A, B) have a material composition that differs from one another. The differing material composition has an effect in particular with regard to differences in flexibility, elasticity, adhesion and/or adhesive tensile strength.

Accordingly, this aspect of the multilayer construction of the carrier web is particularly advantageous in combination with the addition of the copolymer comprising ethylene and vinyl acetate to the material of the carrier web and/or as the material of the carrier web.

Accordingly, the copolymer comprising ethylene and vinyl acetate can be incorporated both in the entire carrier web, in particular in each layer of the carrier web, or also only in at least one layer of the carrier web. This allows a high adaptability of the carrier web to different purposes or but also environments of use. For example, the outer side of the carrier web facing the nonwoven and/or the tile adhesive can be provided with and/or mixed with the copolymer comprising ethylene and vinyl acetate, whereby the adhesion to the nonwoven and/or the tile adhesive can be significantly improved.

Particularly preferably, at least one layer—either layer A and/or layer B—of the carrier web comprises and/or consists of the copolymer comprising ethylene and vinyl acetate, in particular ethylene-vinyl acetate (EVAC). Particularly preferably, at least one outer layer comprises and/or consists of the copolymer comprising ethylene and vinyl acetate, as previously mentioned. Preferably, a layer structure in the form A-B-A or A-B is provided.

In a layered structure of the form A-B-A, the outer layers A, A may be at least substantially identical in construction—i.e. the same material composition and/or the same layer thickness.

In principle, a layered structure in the form A-B-C would also be conceivable, in which case an outer layer C would be different from the outer layer A. In this case, the outer layer C can have a different proportion of the copolymer comprising ethylene and vinyl acetate or contain no copolymer at all comprising ethylene and vinyl acetate.

The aforementioned layer structures enable, according to the invention, that the copolymer containing ethylene and vinyl acetate is ultimately used in those layers—and contributes to the improvement of the mechanical properties there—where it is also “needed”. For example, it is not immediately necessary to integrate the copolymer comprising ethylene and vinyl acetate in the middle layer (layer B), although this is of course not excluded according to the invention.

The outer sides and/or outer layers of the backing sheet may comprise the copolymer comprising ethylene and vinyl acetate, it being possible, if required, for only one outer side and/or one outer layer of the carrier web to comprise the copolymer comprising ethylene and vinyl acetate. By integrating the copolymer comprising ethylene and vinyl acetate into the outer layers, in particular the adhesion of the carrier web to nonwoven and/or the adhesion to the tile adhesive, in particular the adhesive tensile strength of the carrier web, can be significantly improved compared to the decoupling webs known in the prior art.

In a further preferred embodiment, it is provided that only one outer layer (A) and/or the outer layers ((A, A) and/or (A, C)) comprise(s) the copolymer comprising ethylene and vinyl acetate. Alternatively, according to the invention, it is possible that each layer ((A, B) and/or (A, B, C)) of the layered structure (for example, A-B, A-B-A and/or A-B-C) of the carrier web comprises and/or consists of the copolymer comprising ethylene and vinyl acetate. Ultimately, the copolymer comprising ethylene and vinyl acetate can be input and/or introduced precisely into the layers in which the properties, in particular the mechanical properties, are to be improved.

In tests carried out, it has been determined that the layer (A, B, C) comprising the copolymer comprising ethylene and vinyl acetate has a mass fraction of the copolymer comprising ethylene and vinyl acetate in the material of the layer (A, B, C) of at least 5 wt. %, preferably between 10 wt. % and 80 wt. %, more preferably between 20 wt. % and 60 wt. %, further preferably between 25 wt. % and 55 wt. %. According to the invention, it has been found that the aforementioned mass fractions of the copolymer comprising ethylene and vinyl acetate particularly improve the adhesion and the decoupling properties of the entire decoupling web and in particular of the carrier web. In particular, at least one thermoplastic polymer and/or elastomer is provided as further material in the layer (A, B, C) comprising the copolymer comprising ethylene and vinyl acetate. Very preferably, HDPE, PE and/or PP is provided as the thermoplastic polymer.

Preferably, the copolymer comprising ethylene and vinyl acetate is blended with the further material of the layer (A, B, C) comprising the copolymer comprising ethylene and vinyl acetate with the further thermoplastic material. The further material may in turn have a mass fraction of the material of the carrier web and/or of the mass fraction of the material of the layer (A, B, C) of at least 20 wt. %, preferably between 30 wt. % to 99 wt. %, more preferably between 40 wt. % to 95% by weight, further preferably between 50 wt. % to 80 wt. %.

Very preferably, it is provided that the mass fractions of the further thermoplastic material added to the mass fractions of the copolymer comprising ethylene and vinyl acetate in the layer (A, B, C) comprising the copolymer comprising ethylene and vinyl acetate add up to 100% by weight. This means that the layer (A, B, C) comprising the copolymer comprising ethylene and vinyl acetate comprises only one other thermoplastic material in addition to the copolymer comprising ethylene and vinyl acetate.

Furthermore, in a very particularly preferred embodiment of the present invention, it is provided that the outer layer (A) and/or the outer layers (A, A) and/or the outer layers (A, C) have at least 10%, preferably between 10% to 90%, further preferably between 40% to 60% and in particular at least substantially 50%, of the layer thickness of a further, in particular central, layer (in particular layer B). The advantage of the above-mentioned ratios is that the outer layers (layer A or layer C) can have a smaller layer thickness and thus a smaller proportion of material—measured in terms of the total proportion of material of the carrier web—in comparison with the “main layer” or central layer B. In the course of the development of the invention it has been found that for the improvement of the adhesion and the decoupling properties according to the invention by the addition of the copolymer containing ethylene and vinyl acetate, an addition in the outer layers of the layer structure is sufficient.

A multilayer structure of the carrier web can be readily produced by extrusion molding. Thus, a coextrusion die and/or a multilayer die may be used for applying or producing the carrier web. Alternatively or additionally, it may be provided that the carrier web can be produced by thermoforming thermoplastic material.

In particular, the extrusion die may be a multi-layer die which provides a layer structure in the form A-B-A or A-B-C or A-B.

Alternatively or additionally, according to the invention, it may be provided that a multilayer blown film is produced which is formed in a thermoforming process, in particular after its production.

Furthermore, the aforementioned preferred ratios of the layer thicknesses of the layer structure of the carrier web can ensure the lowest possible material consumption of the copolymer comprising ethylene and vinyl acetate, while at the same time ensuring the improvements according to the invention associated with the copolymer comprising ethylene and vinyl acetate compared to the prior art.

Preferably, the carrier web, in particular the decoupling web, has an adhesive tensile strength of greater than 0.1 N/mm2, preferably greater than 0.2 N/mm2, more preferably between 0.2 N/mm2 and 5 N/mm2.

The adhesive tensile strength is determined by means of a special test, which is also called adhesive tensile test and/or tear-off test. DIN EN 12004:2017-05 has a specification for determining the adhesive tensile strength under defined conditions.

Adhesive tensile strengths of the order of magnitude mentioned above enable, in particular, good adhesion to the underground and also ensure good adhesion to the tile adhesive. According to the invention, the adhesive tensile strength of the carrier web can be increased by adding the copolymer comprising ethylene and vinyl acetate.

In a further preferred embodiment of the present invention, it is provided that the carrier web, in particular the decoupling web, has a modulus of elasticity of less than 100 GPa, preferably less than 10 GPa, more preferably between 0.01 to 5 GPa and preferably between 0.05 to 2.5 GPa. The modulus of elasticity is a material characteristic value from materials engineering, which ultimately describes the proportional relationship between stress and strain during the deformation of a solid body in the case of a linear-elastic behavior. The modulus of elasticity is the proportional elastic constant in Hooke's law. The higher the modulus of elasticity, the less elastic and/or flexible the solid body.

In particular, the modulus of elasticity can be determined according to EN ISO 527-1 (as of May 2019). The aforementioned standard is a European standard for plastics for the determination of tensile properties, which can be determined by a tensile test with a tensile testing machine.

Furthermore, the decoupling web may comprise a fabric and/or non-woven layer, in particular on the side opposite of the carrier web plane. The fabric and/or non-woven layer may be firmly bonded to the carrier web, in particular wherein the fabric and/or non-woven layer is laminated to the carrier web. The adhesion to the nonwoven layer can be improved, preferably by up to 30%, compared to the prior art, in particular by using the copolymer comprising ethylene and vinyl acetate. A spunbonded nonwoven can be used as the nonwoven, in particular wherein a spunbonded nonwoven comprising a thermoplastic is provided, preferably a polypropylene spunbonded nonwoven.

The nonwoven may ultimately correspond to the nonwovens already known in practice, which are arranged on a carrier web.

Furthermore, in another embodiment of the invention, it may be provided that the nubs are spaced apart and, preferably, transverse to the longitudinal direction and in the longitudinal direction of the decoupling web. In this respect, the nubs may be spaced from the carrier web plane and from a lower nub plane formed by the nub end face. Ultimately, the nubs constitute so-called “depressions” in the carrier web, so that ultimately an upper carrier web plane results which comprises a plurality of depressions formed by the nubs, so that the nub end faces form the lower nub plane. According to the invention, the aforementioned formation of the nubs enables “channels” to be formed which contribute to decoupling.

According to the invention, different shapes of the nubs are conceivable. For example, an at least substantially cuboidal nub may be used. A nub with an at least substantially three-legged shape—as seen in cross-section—is also conceivable.

In particular, elliptical, preferably round and/or oval, shapes—seen in cross-section—of the nub are also conceivable.

The nubs formed as recesses ultimately form side walls of the nubs, which connect the nub end faces to the carrier web plane.

Very particularly preferably, it is provided that the nubs and/or at least one nub have, at least in sections, an undercut, preferably on at least one side wall of the nub. The undercut serves to improve the adhesion and/or the bonding of the tile adhesive.

According to the invention, it is understood that the decoupling web is filled after being laid on an underground, in particular wherein the outer side of the carrier web comprising the fleece or fabric layer is arranged against the underground. Filling out can be carried out in particular with tile adhesive. A surface covering, in particular tiles, can then be arranged on the tile adhesive. The tile adhesive can preferably be introduced into the nubs and/or into the depressions formed by the nubs and filled out over the decoupling web.

The tile adhesive penetrates the undercut during the filling process, resulting in improved adhesion. This in turn leads to a fixation and/or positive locking of the tile sheet and/or covering elements to be applied to the decoupling web.

In a particularly preferred embodiment of the invention, the formation for forming the undercut on the inside of the nub is crescent-shaped or arcuate and/or arcuate-section-shaped and/or crescent-shaped. In particular, this arcuate section-shaped formation results in improved demolding during the manufacture of the decoupling web. In contrast to angular undercuts, a rounded or sickle-shaped form of the undercut advantageously ensures an easy separation between the forming tool and the decoupling web. Thus, the decoupling web in particular cannot be damaged during demoulding. Moreover, the rounded undercuts preferably serve to ensure that the stress peaks of the shear stress of the lining elements are reduced and/or evenly distributed on the decoupling web.

Very particularly preferably, it is provided that the nubs, in particular all the nubs, are at least substantially identical in construction.

In another preferred embodiment, the height of the nubs is between 1 mm and 5 mm, preferably 2 mm to 4 mm, more preferably 2.5 mm to 3.5 mm. This comparatively low stud height allows for a low overall layer build-up and implies the reduced amount of tile adhesive required for the connection between the decoupling web and the covering elements. Nevertheless, due to the addition of the copolymer comprising ethylene and vinyl acetate according to the invention, a strong bond is achieved between the tile adhesive and the decoupling web while simultaneously achieving an excellent decoupling effect.

In another preferred embodiment, the clear distance between adjacent nubs has a width greater than 2 mm, in particular between 3 mm to 9 mm, preferably between 4 mm to 8 mm, more preferably between 5 mm to 6 mm. This clear distance also determines the width of the channel section and definition with the free space to the adjacent nubs.

In addition, in a further preferred embodiment, it is provided that the ratio of the area of the nub bottoms and/or nub end faces of all studs to the carrier web plane is preferably between 40% and 70%, further preferably between 45% and 55%, and in particular at least substantially 50%. In tests carried out, it has been found that, if the aforementioned ratios are observed, particularly good decoupling values can be achieved with a simultaneously particularly firm fixing of the tile adhesive to the decoupling web. The aforementioned ratios, together with the nub height, also decisively define, among other things, the required quantity of tile adhesive used to bond the decoupling web and the covering element. On the carrier plate, in particular, a load distribution of the occurring tensile stress is made possible by the channels, because preferably a compensation of the occurring stress is carried out. In tests, it was ultimately found that the ratio of 40% to 60%, preferably 45% to 55%, is particularly advantageous and exhibits good decoupling properties and good adhesive tensile strength.

Moreover, it is understood that any intermediate intervals and individual values are included in the aforementioned intervals and range limits and are to be considered disclosed as essential to the invention, even if these intermediate intervals and individual values are not specifically indicated.

Further features, advantages and possible applications of the present invention will be apparent from the following description of examples of embodiments with reference to the drawing and the drawing itself. In this connection, all the features described and/or illustrated constitute, individually or in any combination, the subject-matter of the present invention, irrespective of their summary in the claims and their relation back.

It shows:

FIG. 1 a schematic representation of a layered structure of the carrier web according to the invention,

FIG. 2 a schematic representation of a further embodiment of a layered structure of the carrier web according to the invention,

FIG. 3 a schematic representation of a further embodiment of a layered structure of the carrier web according to the invention,

FIG. 4 a schematic representation of a further embodiment of a layered structure of the carrier web according to the invention,

FIG. 5 a schematic cross-sectional view of a decoupling web according to the invention for use for a tile covering,

FIG. 6 a schematic perspective view of a decoupling web according to the invention,

FIG. 7 a schematic perspective view of a further embodiment of a decoupling web according to the invention, and

FIG. 8 a schematic perspective view of a further embodiment of a decoupling web according to the invention.

FIG. 6 shows a decoupling web 1. The decoupling web 1 has a carrier web 3 and a plurality of nubs 5 projecting from the carrier web plane 4. The carrier web 3 has as material a plastic and/or consists of a plastic. In particular, the carrier web 3 may comprise a thermoplastic material.

FIG. 5 shows that the decoupling web 1 is provided for use for a surface covering structure 2 which can be covered with covering elements, in the illustrated embodiment example with tiles 14. FIG. 5 shows that a tile covering is provided as the surface covering structure 2.

The carrier web 3 shown in the embodiment examples has as material a copolymer containing ethylene and vinyl acetate and/or consists thereof. In particular, the copolymer comprising ethylene and vinyl acetate is formed as a copolymer of ethylene and vinyl acetate, preferably as ethylene-vinyl acetate (EVA, EVAC).

The carrier web 3 may comprise as further material at least one thermoplastic polymer and/or elastomer. In particular, the thermoplastic polymer and thus the further material may be HDPE, PE and/or PP. The copolymer comprising ethylene and vinyl acetate may be blended with the further thermoplastic material. Moreover, the further thermoplastic plastic material of the carrier web 3 may have a mass fraction of the material of the carrier web 3 between 40 to 95 wt. %. The proportion of the material of the carrier web 3 of the further thermoplastic plastic material, in particular in relation to the copolymer comprising ethylene and vinyl acetate, can be selected depending on the application environment or the intended use.

Not shown is that the copolymer comprising ethylene and vinyl acetate may have a mass fraction of the material of the carrier web 3 of at least 5 wt. %, and in further embodiments between 25 wt. % to 55 wt. %.

Furthermore, it is not shown that the copolymer comprising ethylene and vinyl acetate has a vinyl acetate content of at least 5% and, in further embodiments, between 16% and 30%—based on the copolymer comprising ethylene and vinyl acetate. In particular, the copolymer comprising ethylene and vinyl acetate is thermoplastic.

In FIG. 1, it is shown that the carrier web 3 has a single-layer structure and is thus formed by the material layer A. In this context, it is understood that this layered structure can also be produced by a multi-layer extrusion die, wherein the layer A can consequently be applied in several layers of the same material composition. Ultimately, the material layer A has an at least substantially homogeneous material distribution.

FIG. 2 shows that the carrier web 3 has at least a two-layered layer structure 6. In FIG. 2, layers A and B are provided, wherein both layer A and layer B are formed as outer layers, i.e. form an outer side of the carrier web 3. The layers A and B have a different material composition from each other. The layer A, shown in FIG. 2, may face the tile adhesive.

Furthermore, at least one layer A and/or B of the carrier web 3 may comprise the copolymer comprising ethylene and vinyl acetate. In particular, the outer layer A comprises the copolymer comprising ethylene and vinyl acetate. In FIG. 2, a layer structure in the form A-B is shown. Here, the layer B may or may not have the copolymer comprising ethylene and vinyl acetate.

FIG. 3 shows a layered structure in the form A-B-A, wherein the outer layers A may be of the same or identical design with respect to their layer thickness 7 and/or their material composition. The layers A shown in FIG. 3 may have a material composition differing from that of the layer B.

FIG. 4 shows a layer structure 6 with the layer sequence A-B-C. Here, the layer C may have a material composition and/or layer thickness 7 that differs from the outer layer A and/or from the layer B. In particular, the outer layer C has a modified proportion of the copolymer comprising ethylene and vinyl acetate or no proportion at all of the copolymer comprising ethylene and vinyl acetate.

In further embodiments, it may be provided that only an outer layer A and/or the outer layers A, A or A, C comprise and/or have the copolymer comprising ethylene and vinyl acetate. In this context, the further layer B provided between the outer layers (A or A, A or A, C), in particular the centrally enclosed layer B, may not comprise any portion of the copolymer comprising ethylene and vinyl acetate.

Furthermore, in further embodiments it may be provided that each layer A, B or A, B, C of the layer structure 6 of the carrier web 3 may comprise the copolymer comprising ethylene and vinyl acetate, wherein the individual layers may be different with respect to their material composition, their properties and/or their layer thicknesses 7. In principle, it is of course also possible that, in addition to the layers A, B, C, a plurality of further layers can be provided which differ with respect to or from the layers A, B and/or A, B, C by their material composition, their properties and/or their layer thickness 7.

The layer A, B and/or C comprising the copolymer comprising ethylene and vinyl acetate may have a mass fraction of the copolymer comprising ethylene and vinyl acetate in the material of the respective layer A, B and/or C of at least 5% by weight. In particular, the mass fraction of the copolymer comprising ethylene and vinyl acetate in the outer layer A and/or in the outer layer C is between 30 to 50 wt. %. In the aforementioned layers A, B, C, as a further material—in addition to the copolymer comprising ethylene and vinyl acetate—at least one thermoplastic plastic material (in particular a polymer and/or elastomer) may be provided. The plastic material may be HDPE, PE and/or PP. The copolymer comprising ethylene and vinyl acetate may be blended with the further plastic material. The further plastic material may have a mass fraction of between 50 to 90 wt. % of the material of the carrier web 3 and/or of the material of the layer A, B and/or C comprising the copolymer comprising ethylene and vinyl acetate. Very preferably, the mass fraction of the further plastic layer in layer B is greater than the mass fraction of the copolymer comprising ethylene and vinyl acetate.

Furthermore, in further embodiments, it may be provided that the mass fraction of the copolymer comprising ethylene and vinyl acetate in the outer layers A and/or C is greater, preferably by at least 50%, than the mass fraction of the copolymer comprising ethylene and vinyl acetate in the central and/or further layer B, respectively.

In FIGS. 2 to 4 it is shown that the outer layer A and/or the outer layers A, A and/or A, C have at least 10%, in the embodiment example shown at least substantially 50%, of the layer thickness 7 of a further, in particular central, layer B. Accordingly, the material of the layer B may have a significantly higher proportion of the total material of the carrier web 3 or of the layer structure 6 of the carrier web 3, in particular of up to 80% and/or of at least 40%.

It is not shown that the carrier web 3, in particular the decoupling web 1, has an adhesive tensile strength of greater than 0.1 N/mm2, in further embodiments between 0.2 N/mm2 to 5 N/mm2.

Furthermore, it is not shown that the carrier web 3, in particular the decoupling web 1, has a modulus of elasticity of less than 100 GPa, in further embodiments between 0.05 to 2.5 GPa.

FIG. 5 shows that the decoupling web 1 comprises a fabric and/or non-woven layer 8. In the illustrated embodiment example, a non-woven layer 8 is provided. The non-woven layer 8 is firmly connected to the carrier web 3. In this regard, the non-woven layer 8 may be laminated to the carrier web 3. In the illustrated embodiment example, the non-woven layer 8 is arranged at the nub end faces 10 and/or at the nub plane 11.

The non-woven layer 8 is arranged on an underground 17, as can be seen in FIG. 5. Thereby, the non-woven layer 8 may be bonded to the untereground 17 via an adhesive layer. In the illustrated embodiment example, the non-woven layer 8 is bonded to the underground 17 by means of the tile adhesive 13.

In the embodiment example shown in FIG. 5, it may be provided that the tile 14 has a height of about 5 mm+/−3 mm. The height of the nubs 5 may be about 4 mm. The tile adhesive 13 applied to the top of the carrier web 4 may for example have a height of between 2 to 10 mm, in particular between 3 to 6 mm. The thickness of the carrier web 3 and/or the non-woven layer 8 may be about 0.5 mm. On the underside of the non-woven layer 8, the tile adhesive layer may have a height of between 3 and 6 mm.

FIGS. 6 to 8 show that the nubs 5 are arranged at a distance from one another. The nubs 5 extend both in the longitudinal direction L and transversely to the longitudinal direction L. In the present case, the nubs 5 have an ordered arrangement. However, this need not be the case. Unordered arrangements of the nubs 5 are also possible. The nubs 5 have a distance 9 from the upper carrier web plane 5 and a lower nub plane 11 formed by the outer nub end faces 10. The nub plane 11 is formed by the nub end faces 10.

FIG. 6 shows that the nubs 5 form an at least substantially cube-shaped depression. FIGS. 7 and 8 show that the nubs 5 have an at least substantially three-legged cross-sectional shape. In principle, however, other shapes are also possible.

The distance 9 from the upper carrier web plane 5 is ultimately defined by the height of the side walls 16 of the nub 5, the side walls 16 connecting the carrier web plane 4 to the nub plane 11. The side walls 16 ultimately define the nub interior 15 of the nubs.

FIG. 5 shows that the nubs 5 and/or at least one nub 5 has an undercut 12 at least in sections. In the illustrated embodiment example, the undercut 12 is formed in the shape of a crescent or an arcuate section. An undercut 12 having an at least substantially rectangular cross-sectional shape is also possible in principle.

In FIG. 8, it is shown that projections 18 are provided on the nub end faces 11. Ultimately, the projections 18 can have any shape and ultimately serve to structure the nub base.

EXECUTION EXAMPLE

A number of embodiments according to the invention are given below, which are compared with a comparative example 0 (not according to the invention).

The embodiments according to the invention to be compared with each other and the comparative example 0 not according to the invention have an at least substantially identical construction of the shape of the decoupling web, the nub shapes of the examples corresponding to each other in geometrical form. The embodiments ultimately differ only with respect to their material composition.

The carrier webs of the decoupling web are manufactured by extrusion of thermoplastic material and subsequent shaping on a vacuum deep roll. To form a decoupling web, a spunbonded polypropylene fleece is laminated to the carrier web on the nub plane. The extrusion is carried out with a multi-layer die, wherein the “single-layer structure” is also obtained by the multi-layer extrusion die, although the same material composition is ultimately present in the applied layers, so that the multi-layer extrusion die can then produce a single-layer structure.

Furthermore, the embodiments to be compared have at least substantially the same overall layer thickness of the carrier web, and in the case of a multilayer structure, the ratio of the layers is indicated in the table below. The nub shape of the embodiments corresponds at least substantially to the square nub shown in FIG. 6.

Furthermore, the materials EVA28, EVA18 and HDPE of the embodiments correspond to each other.

The embodiments have the following material composition:

Example Layer A Layer B Ratio A:B:A Comparison 100% HDPE / / example 0 Example 1 70% HDPE / / 30% EVA28 Example 2 60% HDPE / / 40% EVA28 Example 3 50% HDPE / / 50% EVA28 Example 4 70% HDPE 100% HDPE 0.25:0.5:0.25 30% EVA28 Example 5 60% HDPE 100% HDPE 0.25:0.5:0.25 40% EVA28 Example 6 50% HDPE 100% HDPE 0.25:0.5:0.25 50% EVA28 Example 7 70% HDPE 90% HDPE 0.25:0.5:0.25 30% EVA28 10% EVA28 Example 8 60% HDPE 95% HDPE 0.25:0.5:0.25 40% EVA28 5% EVA28 Example 9 70% HDPE / / 30% EVA18 Example 10 60% HDPE / / 40% EVA18 Example 11 60% HDPE 100% HDPE 0.15:0.7:0.15 40% EVA28 Example 12 30% HDPE 100% HDPE 0.15:0.7:0.15 70% EVA18 Example 13 30% HDPE 100% HDPE 0.3:0.7:0 70% EVA18 Example 14 30% HDPE 100% HDPE 0.2:0.8:0 70% EVA18

In examples 12 and 13, a two-layer structure is provided, namely a layer structure of the form AB. A spunbonded layer comprising polypropylene is arranged, in particular laminated, on the layer B.

HDPE is provided as the thermoplastic further plastic material and also as the material for the comparative examples not according to the invention. The copolymer comprising ethylene and vinyl acetate is formed as ethylene-vinyl acetate and has a vinyl acetate content of at least substantially 28% based on the copolymer of ethylene and vinyl acetate. This material is referred to as “EVA28”. Another copolymer comprising ethylene and vinyl acetate is formed as ethylene-vinyl acetate and has a vinyl acetate content of at least substantially 18% based on the copolymer of ethylene and vinyl acetate. This material is referred to as “EVA18”. When the copolymer of ethylene and vinyl acetate is added to the thermoplastic material, it is envisaged that it is admixed with the thermoplastic material prior to extrusion of the carrier web. Extrusion is performed with both the thermoplastic resin material and the copolymer of ethylene and vinyl acetate.

The above-mentioned design examples have been examined with regard to different criteria. The adhesive tensile strength has been determined according to DIN EN 12004-02:2017-05. Furthermore, the modulus of elasticity has been determined to determine the flexibility. In addition, the decoupling properties have been investigated when using the decoupling membrane as a decoupling underlay for a tile covering. Furthermore, the adhesion to the tile adhesive of the decoupling membrane has been determined. The water tightness has also been determined.

The results table shown below relates the experimental results relative to each other. The following results can be achieved:

    • −−−: unsatisfactory result
    • −−: unsatisfactory result
    • ∘: satisfactory result
    • +: good result
    • ++: very good result

The table below illustrates the results:

Adhesive Adhesion tensile to the tile Water- Example strength Flexibility adhesive density Decoupling Comparison ∘ ∘ − ++ ∘ example 0 Example 1 ∘ + +/++ ++ +/++ Example 2 + ++ ++ ++ ++ Example 3 ++ ++ ++ ++ + Example 4 + ∘/+  + ++ + Example 5 ++ + ++ ++ ++ Example 6 ++ + ++ ++ ++ Example 7 + + +/++ ++ +/++ Example 8 ++ +/++ ++ ++ ++ Example 9 ∘ ∘ ∘ ++ + Example 10 ∘ + + ++ +/++ Example 11 ++ +/++ ++ ++ +/++ Example 12 ++ +/++ ++ ++ ++ Example 13 ++ + ++ ++ +/++ Example 14 ++ +/++ ++ ++ ++

The above results illustrate that by adding the copolymer containing ethylene and vinyl acetate to the material of the carrier web according to the invention, both the adhesive tensile strength and the flexibility (by reducing the modulus of elasticity) can be improved. Even with increasing amounts of the copolymer containing ethylene and vinyl acetate (EVA28) only in the outer layers (layer A), very good adhesive tensile strengths can be achieved. Even up to 50% of the copolymer containing ethylene and vinyl acetate (EVA28) or even up to 70% of the copolymer containing ethylene and vinyl acetate (EVA18) can be added to the outer layer A without the decoupling web becoming too soft.

Furthermore, even better flexibility results are obtained if the central layer B sandwiched between the outer layers A also contains the copolymer comprising ethylene and vinyl acetate.

Alternatively, very good results are also achieved if, in a two-layer structure (AB), only the outer layer A contains the copolymer comprising ethylene and vinyl acetate.

Ultimately, the water resistance remains virtually unaffected by the addition of the copolymer containing ethylene and vinyl acetate.

In addition to the adhesive tensile strength, the addition of the copolymer comprising ethylene and vinyl acetate can also improve the adhesion to the tile adhesive and the decoupling properties. This results in an improved application and use of the decoupling sheet according to the invention.

REFERENCE LIST

1 Decoupling web

2 Surface covering structure

3 Carrier web

4 Carrier web plane

5 Nubs

6 Layer structure

7 Layer thickness

8 Nonwoven layer

9 Distance

10 Nub end faces

11 Nub plane

12 Undercut

13 Tile adhesive

14 Tile

15 Nub interior

16 Side wall

17 Underground

18 Projection

A Layer

B Layer

C Layer

L Longitudinal direction

Claims

1. A decoupling web, in particular intended for use for a surface covering structure which can be covered with covering elements, preferably tile coverings, having a carrier web and a multiplicity of nubs projecting from the carrier web plane, the carrier web comprising as material a, preferably thermoplastic, plastic, wherein

the carrier web comprises as material a copolymer comprising ethylene and vinyl acetate, in particular a copolymer of ethylene and vinyl acetate, preferably ethylene-vinyl acetate (EVA), and/or consists thereof.

2. The decoupling web according to claim 1, wherein the carrier web comprises as further material at least one thermoplastic polymer and/or elastomer, in particular hard polyethylene (HDPE), polyethylene (PE) and/or polypropylene (PP), in particular wherein the copolymer containing ethylene and vinyl acetate is mixed with the further material and/or wherein the further material has a mass fraction of the material of the carrier web of at least 20 wt. %, preferably between 30 wt. % and 99 wt. %, further preferably between 40 wt. % and 95 wt. %, further preferably between 50 wt. % and 80 wt. %, preferably between 30 wt. % and 99 wt. %, further preferably between 40 wt. % and 95 wt. %, further preferably further between 50 wt. % and 80 wt. %.

3. The decoupling web according to claim 1, wherein the copolymer comprising ethylene and vinyl acetate has a mass fraction in the material of the carrier web of at least 5 wt. %, preferably between 10 wt. % to 80 wt. %, more preferably between 20 wt. % to 60 wt. %, more preferably further between 25 wt. % to 55 wt. %.

4. The decoupling web according to claim 1, wherein the copolymer comprising ethylene and vinyl acetate has a vinyl acetate content of at least 5%, preferably between 10% and 50%, more preferably between 12% and 40%, further preferably between 16% and 30%, and in particular at least substantially from 25% to 29%, in particular based on the copolymer comprising ethylene and vinyl acetate.

5. The decoupling web according to claim 1, wherein the carrier web has an at least two-layer layer structure, at least two layers (A, B) having a material composition differing from one another.

6. The decoupling web according to claim 1, wherein at least one layer (A, B) of the carrier web comprises the copolymer comprising ethylene and vinyl acetate, in particular wherein at least one outer layer (A) comprises the copolymer comprising ethylene and vinyl acetate and, preferably, wherein a layer structure A-B-A or A-B is provided.

7. The decoupling web according to claim 1, wherein only one outer layer (A) and/or the outer layers (A, A) comprise(s) the copolymer comprising ethylene and vinyl acetate or that each layer (A, B) of the layer structure of the carrier web comprises the copolymer comprising ethylene and vinyl acetate.

8. The decoupling web according to claim 1, wherein the layer (A, B) comprising the copolymer comprising ethylene and vinyl acetate has a mass fraction of the copolymer comprising ethylene and vinyl acetate in the material of the layer (A, B) of at least 5 wt. %, preferably between 10 wt. % and 80 wt. %, more preferably between 20 wt. % and 60 wt. %, more preferably between 25 wt. % and 55 wt. %, in particular wherein at least one thermoplastic polymer and/or elastomer, in particular hard polyethylene (HDPE), polyethylene (PE) and/or polypropylene (PP), is provided as the further material and, preferably, wherein the copolymer containing ethylene and vinyl acetate is mixed with the further material and/or the further material has a mass fraction of the material of the carrier web and/or of the material of the layer (A, B) containing the copolymer containing ethylene and vinyl acetate of at least 20 wt. %, preferably between 30 wt. % and 99 wt. %, more preferably between 40 wt. % and 95 wt. %, further preferably between 50 wt. % and 80 wt. %.

9. The decoupling web according to claim 1, wherein the outer layer (A) and/or the outer layers (A, A) has/have at least 10%, preferably between 10% and 90%, more preferably between 40% and 60% and in particular at least substantially 50%, of the layer thickness of a further, in particular central, layer (B).

10. The decoupling web according to claim 1, wherein the carrier web, in particular the decoupling web, has an adhesive tensile strength of greater than 0.1 N/mm2, preferably greater than 0.2 N/mm2, more preferably between 0.2 N/mm2 and 5 N/mm2.

11. The decoupling web according to claim 1, wherein the carrier web, in particular the decoupling web, has a modulus of elasticity of less than 100 GPa, preferably less than 10 GPa, more preferably between 0.01 to 5 GPa and preferably between 0.05 to 2.5 GPa.

12. The decoupling web according to claim 1, wherein the decoupling web has, in particular on the side opposite the carrier web plane, a fabric and/or nonwoven layer, in particular the nonwoven layer being firmly connected to the carrier web, in particular being laminated onto the carrier web.

13. The decoupling web according to claim 1, wherein the nubs are arranged at a distance from one another and, preferably, transversely to the longitudinal direction (L) and in the longitudinal direction (L) of the decoupling web, in particular wherein the nubs form a distance from the upper carrier web plane and a lower nub plane formed by the outer nub end faces.

14. The decoupling web according to claim 1, wherein at least one nub has an undercut at least in sections.

Patent History
Publication number: 20220372767
Type: Application
Filed: Jun 18, 2020
Publication Date: Nov 24, 2022
Inventors: Uwe KAISER (Herdecke), Birgit STRIEDER (Bochum), Daniel KARGL (Dortmund), Thomas BACHON (Düsseldorf)
Application Number: 17/623,308
Classifications
International Classification: E04F 15/18 (20060101);