EP4012129B1 - Sealing tape roll - Google Patents

Description

The present invention relates to a sealing tape roll made of a sealing tape of soft, compressible foam, which is impregnated to delay recovery after compression and comprises, at least in some areas, a substance that reduces the thermal conductivity of the sealing tape.

Compressible sealing tapes are used to seal joints between a frame profile, such as a window or door, and a building wall, protecting against drafts and driving rain. These tapes are typically compressed and wound into rolls for space-saving storage, transport, and easier handling during installation. When these pre-compressed sealing tapes are installed in a joint between, for example, a window frame and a wall, the foam of the tape elastically returns to its original shape, thus sealing the joint. In addition to air permeability and resistance to driving rain, the thermal conductivity of the sealing tape is one of its most important properties. Low thermal conductivity improves thermal insulation.

In general, the foams used to manufacture sealing tapes exhibit relatively low thermal conductivity due to the numerous air-filled pores between the cell walls, making them fundamentally suitable for effective thermal insulation. However, the foam of a compressible sealing tape is typically impregnated with an adhesive to delay its return to its fully expanded state, thus improving workability on the construction site. This delayed return is often utilized when sealing joints: the foam is initially compressed and inserted into the joint to be sealed, whereupon it expands on its own to a partially expanded state, sealing the joint.

However, impregnating the foam has the undesirable effect of increasing the thermal conductivity of the sealing tape due to the material properties of the impregnating agent and its homogeneous distribution within the foam. Consequently, a joint sealed with such an impregnated sealing tape has reduced thermal insulation.

Measures to reduce the thermal conductivity of joint sealing tapes are, for example, derived from the WO 2018/127381 A1 known. The WO 2018/127381 A1 Disclosing a sealing tape treated with an impregnating compound containing aerogel particles made of pyrogenic silica. The incorporated aerogel particles are intended to counteract the reduction in pore space within the foam due to compression of the sealing tape and thus reduce the thermal conductivity of the sealing tape, particularly in a compressed state.

EP 1 705 232 A1 discloses a compressible sealing tape made of soft foam, which is impregnated for delayed recovery and whose air permeability is reduced by the addition of expanded plastic spheres consisting of a polymer shell containing gas.

The present invention is based on the objective of providing a sealing tape wound into a sealing tape roll that combines the properties of delayed recovery and high thermal insulation with good compressibility.

This problem is solved by a sealing tape roll according to claim 1. Preferred embodiments are the subject of the dependent claims.

A sealing tape roll according to the invention consists of a sealing tape made of soft, compressible foam, which is impregnated to delay its recovery after compression and comprises, at least in some areas, at least one substance that reduces the thermal conductivity of the sealing tape. The sealing tape has a top surface, a bottom surface, and two side flanks connecting the top surface and the bottom surface, a longitudinal direction oriented parallel to the bottom surface and the side flanks, and transverse to a transverse direction, and a vertical direction oriented perpendicular to the bottom surface of the sealing tape. The sealing tape is wound around an axis extending transversely to the longitudinal direction of the sealing tape to form a sealing tape roll such that the top surface of one turn rests against the bottom surface of an adjacent turn of the sealing tape roll, and the side flanks of the sealing tape form end faces of the sealing tape roll. The substance consists of small plastic spheres made of a polymer shell containing gas, which have been expanded due to heating. When wound up in the sealing tape roll, the tape has a compressed height in the vertical direction of 5-30% of the initial height of the fully expanded sealing tape. The impregnated foam It has a density of 30-70 kg/ ^m³ . The surfaces of the plastic spheres are modified to have a hydrophobic surface layer. The thermal conductivity of the sealing tape is ≤ 0.040 W/mK both in a partially compressed state (at a height of 40-75% of the uncompressed initial height) and in an uncompressed state.

In this way, a sealing tape wound into a roll with delayed recovery is provided, wherein the at least one substance effectively reduces the thermal conductivity of the sealing tape, while the compressibility of the sealing tape is still largely maintained.

Sealing tapes extend significantly further in their longitudinal direction than in their transverse direction and are therefore wound around a pivot axis to form a tape roll for space-saving storage, during which the foam of the sealing tape is highly compressed. Even in the partially compressed installed state, the sealing tape foam does not fully expand, as effective sealing of joints could not be guaranteed in this way. The installed state of the sealing tape is defined as the partially compressed state in which the sealing tape is positioned in a joint between a frame element, e.g., a window or door frame, and a building wall. In this state, the longitudinal direction of the sealing tape extends along the perimeter of the joint, and the sealing tape lies flat against the frame element and the building wall with both its top and bottom surfaces in contact. One side of the sealing tape then faces the interior of the room, and the opposite side faces the exterior. The vertical direction of the sealing tape extends perpendicular to the underside between the frame element and the building wall.

High compressibility is therefore an essential basis for the versatile and flexible application of a sealing tape.

The sealing tape consists of a permanently elastic soft foam. The foam has a net-like framework in which struts with interposed cell membranes are arranged. A suitable foam for the invention is also resilient, i.e., it should expand back to its uncompressed original state on its own after compression. The sealing tape therefore consists of any open-cell or mixed-cell resilient foam selected from the group comprising polyurethane foam, melamine resin foam, silicone foam, PVC foam, or polyethylene foam. In a preferred embodiment, the foam is a polyurethane foam (PU foam). Preferably, the foam is an open-cell foam, e.g., an open-cell PU foam. Alternatively, the foam can also be a mixed-cell foam, which has both open and closed cell walls. Furthermore, the foam can also be a reticulated foam (e.g., a reticulated PU foam) in which all or at least some of the foam cell walls have been perforated during a post-treatment.

Such raw foam materials have a density of 20-200 kg/m ³ , preferably 20-50 kg/m ³ , particularly preferably 28-30 kg/m ³ .

Preferably, the raw soft foam has a compression hardness of more than 2 kPa. Preferably, the compression hardness is more than 2.1 kPa, more preferably more than 2.2 kPa, and particularly preferably more than 2.3 kPa. The compression hardness is preferably less than 4 kPa, more preferably less than 3.8 kPa, and more preferably less than 3.6 kPa. Compression hardness is a measure of the foam's strength. The values given here are based on a compression of 40% of the original height. Compression hardness is determined according to DIN EN ISO 3386, and the CV40 value is specified.

The foam forming the sealing tape is furthermore at least partially, and preferably completely, treated with an adhesive impregnating agent to delay the recovery of the compressed foam after compression and thus provide sufficient time for sealing even hard-to-reach or particularly thin joints. The impregnating agent is preferably an adhesive solution, suspension, or dispersion. Preferably, it comprises an acrylate dispersion. In an advantageous embodiment, the acrylate dispersion comprises acrylate polymer particles dispersed in a homogeneous phase. Particularly preferably, the foam is impregnated with a weight fraction of acrylate dispersion for delayed recovery such that, at 20°C and 50% relative humidity, the sealing tape recovers from a compression level of approximately 9% to 13% of its initial height to complete joint closure in less than 24 hours. Alternatively, it can also be advantageous to use chlorinated paraffin or bitumen as the base for the impregnating agent.

The impregnating agent further contains at least one substance that reduces the thermal conductivity of the sealing tape. In the context of the invention, the terms "reduce," "lower," or "decrease" of thermal conductivity shall be understood to mean that the thermal conductivity of a sealing tape is lower due to the at least one substance than that of an otherwise identical sealing tape that does not contain this substance.

The substance is present in the impregnating agent at a proportion of 1-25 wt.%, preferably 1-7 wt.%, more preferably 3-6 wt.%, and most preferably 5-6 wt.%, in each case based on 100 wt.% impregnating agent. The substance does not dissolve in the impregnating agent but remains present in particle form. Preferably, the substance is homogeneously distributed in the impregnating agent, i.e., it is preferably dispersed within it.

The impregnating agent may also contain one or more binders, fillers, and/or additives, such as flame retardants, water-repellent agents, thermoexpandable substances, dyes, UV-resistant substances, or similar materials. In addition to delayed recovery and reduced thermal conductivity, the impregnating agent can thus provide the foam, and consequently the sealing tape, with further functionalities, such as flame retardancy, UV protection, water repellency, airtightness, or coloration. Accordingly, the sealing tape preferably complies with several DIN standards with regard to, for example, fire behavior (e.g., DIN 4102-B1, DIN 4102-B2, DIN 4102-≥F30), compatibility with other building materials, temperature stability, resistance to driving rain, or UV resistance.

In a preferred embodiment, the foam of the sealing tape is impregnated with the impregnating agent containing the substance by means of soaking. The foam is immersed in the impregnating agent in such a way that the impregnating agent, along with the substance, penetrates the foam cells and completely or at least partially wets the inner and outer cell structure. Therefore, the impregnating agent used for impregnating the sealing tape should preferably be of average viscosity. Furthermore, it can be advantageous if the sealing tape comprises an open-cell foam to achieve the most homogeneous possible penetration and distribution of the impregnating agent, and thus of the substance, within the foam. The amount of impregnating agent absorbed by the foam can subsequently be adjusted optionally by squeezing out the impregnated foam.

The impregnation process introduces the thermal conductivity-reducing substance into the sealing tape. Accordingly, the substance is not added to the raw materials during the foam production process, but rather added to the already manufactured raw foam afterward. This allows for flexible customization of the sealing tape with at least one of these substances.

In a preferred embodiment, the substance is homogeneously distributed in the sealing tape by impregnation, i.e., the substance has a distribution that extends largely uniformly over the entire width and length of the sealing tape. According to the invention, the substance is present in the final sealing tape of the sealing tape roll at a proportion of 0.2–15 wt.%, preferably 0.3–10 wt.%, e.g., 0.3 wt.%, 1 wt.%, or 3 wt.%.

The substance should also be dimensioned such that it is present within the cells of the foam after impregnation. Therefore, the substance should consist of individual particles with a diameter of less than 500 µm, preferably less than 400 µm, less than 300 µm, less than 200 µm, and most preferably less than 150 µm.

The substance consists of microspheres, i.e., small plastic spheres comprising a polymer shell containing gas, which are expanded due to heating. In their expanded state, the plastic spheres have a diameter of 30-120 µm, preferably 30-50 µm, e.g., 35 µm, 40 µm, or 45 µm. According to the invention, the surfaces of the plastic spheres are modified to have a hydrophobic surface layer.

The plastic spheres are preferably added to the impregnating agent in an unexpanded state with a diameter of approximately 10 µm, i.e., they are dispersed in the impregnating agent. Expansion of the spheres then occurs due to the temperature increase during the drying of the impregnated foam. The impregnated foam is usually dried at temperatures of 70 °C to 210 °C, preferably at approximately 100 °C to 190 °C, for a period of approximately 1 to 20 minutes. Due to the heating, the gas inside the plastic spheres expands and increases the internal pressure, while the polymer shell softens due to the heat. As a result, the microsphere volume increases to usually more than forty to sixty times the initial volume. At the same time, the specific gravity of the spheres decreases. Plastic spheres expand from approximately 1,000 kg/ ^m³ to about 30 kg/ ^m³ . In other embodiments, partially or fully pre-expanded plastic spheres can also be added to the impregnating agent. The microspheres, expanded by heating, retain their increased volume long-term, even under normal temperature conditions. At the same time, the expanded plastic spheres remain permanently elastic, meaning they can still be compressed within the sealing tape. Therefore, despite the plastic spheres it contains, the sealing tape can be wound onto a roll in a highly pre-compressed state.

By adhering to the expanded plastic spheres within the foam pores and/or to the cell walls and struts of the foam cell structures, the spheres form bulbous, gas-filled protrusions, which lead to a reduction in the thermal conductivity of the sealing tape.

Thermal conductivity (also known as thermal conductivity coefficient λ, k, or κ) refers to the property of a material to transport thermal energy in the form of heat via conduction; that is, thermal conductivity is determined by the rate at which heat spreads through a material. Thermal conductivity is expressed in watts per meter per kelvin (W/mK).

According to the invention, the thermal conductivity of the sealing tape comprising the plastic spheres described herein is ≤ 0.040 W/mK, preferably ≤ 0.395 W/mK, both in a partially compressed state between 40 and 75% and in an uncompressed state. The thermal conductivity values provided in this application refer to a determination under standard conditions according to DIN EN 12667 using a suitable plate tester, taking into account the sample dimensions and density at a mean sample temperature of 10°C (see example below).

The final sealing tape, in a fully expanded state, has a height of 5 mm - 200 mm, preferably 10 mm - 120 mm, particularly preferably 10 mm - 90 mm or 20-80 mm.

Finally, it is advantageous that the underside of the sealing tape has an adhesive layer for bonding the tape to a frame element. When wound into a roll, the underside of the sealing tape faces radially outwards. This allows the tape to be unwound along a frame element and quickly attached using... The adhesive layer is attached to the sealing tape. The adhesive layer is preferably designed as a double-sided adhesive tape covered on one side with a removable protective film. The adhesive layer can also be applied to the top of the sealing tape, either additionally or alternatively. The sealing tape can also be attached to the building wall using the adhesive layer instead of the frame element.

Fig. 1

zeigt eine Ausführungsform einer erfindungsgemäßen Dichtbandrolle in einer perspektivischen Ansicht; und

Fig. 2

zeigt eine schematische vergrößerte Querschnittsansicht eines Schaumstoffs, aus der die Zellstruktur des Schaumstoffs und die innerhalb der Schaumstoffzellen befindlichen Kunststoffkugeln ersichtlich sind.

Further features and advantages of the present invention will become apparent from the following description with reference to the drawings.

Fig. 1

shows an embodiment of a sealing tape roll according to the invention in a perspective view; and

Fig. 2

shows a schematic enlarged cross-sectional view of a foam, from which the cell structure of the foam and the plastic balls located inside the foam cells can be seen.

Fig. 1 Figure 1 shows a sealing tape roll 1 according to the invention in a perspective view. The sealing tape roll 1 comprises a wound sealing tape 2. The sealing tape 2 is in Fig. 1 For better illustration of its components, the sealing tape 2 is shown partially unwound from the sealing tape roll 1, with one end of the sealing tape 2, located at the outer edge of the sealing tape roll 1, not wound onto the sealing tape roll 1. As can be seen, the sealing tape 2 is compressed and wound onto the sealing tape roll 1 to allow for space-saving storage of the sealing tape rolls 1. The sealing tape 2 is impregnated to delay its return to its original shape. The portion of the sealing tape 2 not wound onto the sealing tape roll 1 is shown in Fig. 1 shown in a fully expanded state.

The sealing tape 2 consists of soft, compressible foam and has a top surface 4, a bottom surface 6, and two side flanks 8, 10 connecting the top surface 4 and the bottom surface 6. A longitudinal direction L of the sealing tape 2 is oriented parallel to the bottom surface 6 and to the side flanks 8, 10 and perpendicular to the transverse direction Q. In its unwound state, the sealing tape 2 lies on a flat surface, for example, on the outer surface of a frame element, with the side flanks 8, 10 oriented perpendicular to the top surface 4 and the bottom surface 6, and the sealing tape 2 being in a fully expanded state. In the compressed state of the sealing tape 2, the side flanks 8, 10 have a lower height H1 than in the expanded state of the sealing tape 2 (height H2). That is, the distance between the top surface 4 and the side flanks 8, 10 is reduced by a factor of 1. 4 and the underside 6 are smaller in the compressed state than in the expanded state. The distance between the side flanks 8, 10 remains essentially unchanged when the sealing tape 2 is compressed.

The sealing tape 2 is wound around an axis A, which extends perpendicular to the longitudinal direction L and perpendicular to the side faces 8, 10 of the sealing tape 2, to form the sealing tape roll 1. Within the sealing tape roll 1, the upper surface 4 of one turn rests against the lower surface 6 of an adjacent turn of the sealing tape roll 1, and the side faces 8, 10 of the sealing tape 2 form end faces 12, 14 of the sealing tape roll 1. The lower surface 6 is directed radially outward with respect to the axis A and the sealing tape roll 1, while the upper surface 4 of the sealing tape 2 is directed radially inward. A surface of the sealing tape roll 1 therefore encompasses the lower surface 6 of the outermost turn of the sealing tape 2 of the sealing tape roll 1.

Preferably, the underside 8 of the sealing tape 2 has an adhesive layer 16 for bonding the sealing tape 2 to a frame element. For example, this adhesive layer 16 is formed by a double-sided adhesive tape that is attached to the foam by means of an adhesive surface. An opposing adhesive surface of the adhesive tape, facing away from the foam, is covered with a protective layer 18 to protect the adhesive surface and to prevent the individual coils of the sealing tape roll 1 from sticking together. To install the sealing tape 2, such a protective layer 18 is peeled back from the adhesive layer 16 in sections, and the sealing tape roll 1 is unwound along an outer surface of a frame element. The protective layer 18 consists, for example, of silicone paper. The adhesive layer 16 bonds the underside 6 of the sealing tape 2 to the frame element. Alternatively, strips of sealing tape can first be cut to the required length from the sealing tape roll 1 and then attached to the frame element.

Fig. 2 Figure 1 shows a schematic enlarged cross-sectional view of a foam 20, from which the cell structure of the foam 20 and the plastic spheres 24 located within the foam cells 22 are visible. The individual foam cells 22 are separated from each other by cell bridges 28. The plastic spheres 24 were subsequently introduced into the foam cells 22 of the sealing tape 2 via an impregnating agent. The plastic spheres 24 then adhere within the foam cells 22 and/or to the cell bridges 28 and reduce the thermal conductivity of the sealing tape 2.

The present invention is further illustrated, but not limited, by the following example.

Examples 1. Comparison of the thermal conductivity of sealing tapes with or without plastic spheres

In the example described herein, the thermal conductivity was measured according to DIN EN 12667 at a mean sample temperature of 10°C on four different sealing tape samples, each 30 mm thick and with a density between 62 kg/ ^m³ and 66 kg/ ^m³ . The samples were not conditioned. To prevent mass changes during the test, the samples were wrapped in thin, clear film.

Probe 1:

PU-Schaumstoff Dichtband + Imprägnat ohne Kunststoffkugeln (unkomprimiert)

Probe 2:

PU-Schaumstoff Dichtband + Imprägnat ohne Kunststoffkugeln (auf 64% der Ausgangshöhe komprimiert)

Probe 3:

PU-Schaumstoff Dichtband + Imprägnat mit Kunststoffkugeln (unkomprimiert)

Probe 4:

PU-Schaumstoff Dichtband + Imprägnat mit Kunststoffkugeln (auf 64% der Ausgangshöhe komprimiert)

The following samples were measured:

Sample 1:

PU foam sealing tape + impregnating agent without plastic beads (uncompressed)

Sample 2:

PU foam sealing tape + impregnating agent without plastic beads (compressed to 64% of the original height)

Sample 3:

PU foam sealing tape + impregnating agent with plastic beads (uncompressed)

Sample 4:

PU foam sealing tape + impregnating agent with plastic beads (compressed to 64% of the original height)

The measurement results for the thermal conductivity of the different sealing tape samples are listed in Table 1. <b>Table 1</b> Thermal conductivity measurement of sealing tapes with or without plastic spheres Sample No. Thermal conductivity λ in W/mK 1 0.0440 2 0.0445 3 0.0391 4 0.0394

The measurement results summarized in Table 1 show that in the presence of plastic spheres, the thermal conductivity of an impregnated sealing tape made of PU foam could be reduced by over 11% in both the partially compressed state (installation situation) and the uncompressed state.

Claims (8)

1. A sealing tape roll (1) produced from a sealing tape (2) made of soft, compressible foam material (20), wherein the sealing tape is impregnated for a delayed resilience after compression and, at least in subsections, comprises at least one substance which reduces the thermal conductivity of the sealing tape (2),

   wherein the sealing tape (2) has an upper side (4), a lower side (6) and two side flanks (8, 19) linking the upper side (4) and the lower side (6), a longitudinal direction (L) which is orientated parallel to the lower side (6) and to the side flanks (8, 10) as well as transversely to a transverse direction (Q), and a height direction (H) which is orientated at right angles to the lower side (8) of the sealing tape (2);

   wherein the sealing tape (2) is rolled up into the sealing tape roll (1) about an axis (A) which extends transversely to the longitudinal direction (L) of the sealing tape (2) in a manner such that the upper side (4) of one turn bears against the lower side (6) of an adjoining turn of the sealing tape roll (1) and the side flanks (8, 10) of the sealing tape (2) form end faces (12, 14) of the sealing tape roll (1);

   wherein the substance consists of small plastic spheres (24) which consist of a polymer shell with gas contained therein and which have been expanded as a result of heating, wherein, in the expanded state, the plastic spheres have a diameter of 30-120 µm;

   characterized in that

   in the rolled-up state in the sealing tape roll (1), the sealing tape (2) has a compressed height (H1) in the height direction (H) of 5-15 % of the initial height (H2) of the fully expanded sealing tape (2);

   the impregnated foam material has a bulk density of 30-70 kg/m³;

   the surfaces of the plastic spheres are modified in a manner such that they have a hydrophobic surface layer; and

   the thermal conductivity of the sealing tape (2) is ≤ 0.040 W/mK both in a partially compressed state with a height of between 40 and 75 % of the uncompressed initial height (H2) of the sealing tape (2) as well as in an uncompressed state of the sealing tape (2).
2. The sealing tape roll (1) as claimed in claim 1, characterized in that the foam material (20) is a resilient foam material selected from the group comprising polyurethane foam, melamine resin foam, silicone foam, PVC foam or polyethylene foam.
3. The sealing tape roll (1) as claimed in one of the preceding claims, characterized in that the substance in the sealing tape (2) is homogeneously distributed.
4. The sealing tape roll (1) as claimed in one of the preceding claims, characterized in that the substance is dimensioned in a manner such that it is present in the cells (22) of the foam material (20) of the sealing tape (2).
5. The sealing tape roll (1) as claimed in one of the preceding claims, characterized in that the lower side (6) of the sealing tape has an adhesive layer (16) for connecting the sealing tape (2) to a frame element.
6. The sealing tape roll (1) as claimed in one of the preceding claims, characterized in that in the expanded state, the plastic spheres have a diameter of 30-50 µm.
7. The sealing tape roll (1) as claimed in one of the preceding claims, characterized in that in the expanded state, the plastic spheres are compressible.
8. The sealing tape roll (1) as claimed in one of the preceding claims, characterized in that the thermal conductivity of the sealing tape (2) is ≤ 0.395 W/mK both in the partially compressed state as well as in the uncompressed state of the sealing tape (2).