EP1983119B1 - Sealing tape made of soft foam - Google Patents

Abstract

The tape has lateral surfaces (3, 4) colored with a colorant such that coloring on the surfaces in a partially expanded functional state of the tape in a distance of a viewer from the surfaces appears as a continuous colored surface for a human eye. The tape is made of soft foam and partially reset after compression. The colorant is designed such that uniform resetting of the tape is ensured over a width of the tape after compression, where the colorant is acrylate dispersion, ethylene vinyl-acetate, poly vinyl acetate, polyurethane or silicate, paraffin-based wax, hydrosilicon and silicone. An independent claim is also included for a method for manufacturing a sealing tape.

Description

The invention relates to a sealing tape made of soft, resilient after compression foam for sealing joints, especially in the construction sector.

Such sealing tapes are usually made of polyethylene or polyurethane foam. The range of these foams ranges from closed-cell foams, which provide virtually no air passage, to open-cell foams, which have a relatively high air permeability. At least open-celled foams are usually soaked to achieve the desired sealing properties with an impregnate. Such impregnates also lead to a delayed recovery of the foam after its compression, since the impregnates usually contain adhesive substances that attach to the cell webs of the foam structure and adhere there. The delayed recovery is often exploited in the sealing of joints by the foam is first compressed and inserted into the joint to be sealed, whereupon the foam expands by itself to a part-expanded functional state and closes the joint.

Also used for sealing pasty and sprayable sealants made of polyurethane, silicone or acrylate, which are also available in various colors on the market. In expansion joints, however, such sealants are hardly usable because they adhere to the joint edges and can tear at excessive elongation.

More and more often sealing tapes are not plastered in the outdoor area of buildings after installation, but are exposed to the weather and partially visible to the viewer from the outside and therefore colored, see, eg AU 663 480 B2 or US 4 181 711 A ,

document US 4,181,711 describes a sealing tape having the features of the preamble of claim 1 and a method having the features of the preamble of claim 5.

It is the object of the present invention to provide a sealing band made of soft, compression-recoverable foam, which is also suitable for use in uncovered outer joints of a building and gives an excellent overall aesthetic impression.

This object is solved by the features of claim 1.

The sealing strip according to the invention made of soft, compression-resilient foam has two side surfaces, wherein at least one of the two side surfaces is colored with a colorant such that the coloring on the side surface in a partially expanded functional state of the partially recovered after compression sealing tape at any distance of a viewer of the side surface for a human eye appears as a closed color surface.

The sealing tape is colored at the at least one side surface in an edge region of up to a few millimeters depth, while in a central region between the side surfaces no coloring is present. This not only serves to minimize colorant consumption, but also prevents interference with the desired basic properties of the foam and a change in hue within a sealant tape or between different batches of sealant tapes.

In microscopic side view, the sealing tape has a plurality of differently sized color spots, wherein the average area of a color spot in the partially expanded functional state of the sealing tape is between 0.0001 and 0.5 mm ² , preferably between 0.0025 and 0.3 mm ² . This surface area has proven to be particularly favorable in terms of achieving the impression of a closed color area for the human eye.

In connection with this it is advantageous that the sealing tape has so many color spots in the edge region of the side surface that the color spots in the partially expanded functional state of the sealing tape in microscopic side view together make up at least 60% of the total visible surface area. As a result, in the case of color spots of the above-mentioned extent, a color impression closed to the viewer is mediated, since the resolution of the human eye can no longer perceive the small gaps between the individual color spots.

As a result, the range of use of sealing tapes made of soft foam when sealing visible for a viewer joints in the construction sector is significantly expanded and created in addition to the sealing function of the sealing tape with only a small amount of ink an aesthetic design option.

Preferably, the sealing band is made of a foam with the property of a delayed recovery after compression, whereby the installation in joints is facilitated. The delayed recovery is usually achieved by impregnation of the foam, but there are now also foams that show a delayed recovery without impregnation.

For better handling is preferably also provided that the colorant is formed such that a uniform recovery of the sealing tape is ensured after compression over the width of the sealing tape.

In order to optimally utilize the sealing properties of the sealing band, the part-expanded functional state of the sealing band lies in a range of between 25% and 60% of the maximum expansion of the sealing band.

The method according to the invention for producing such a sealing tape comprises the steps of providing a soft, compression-recoverable foam sealing tape having two side surfaces and coloring at least one of the two side surfaces with a coloring agent so that the coloring on the side surface for the human eye a partially expanded functional state of the partially recovered after compression sealing band appears as a closed color layer.

The coloring of the side surface in an edge region of up to a few millimeters depth can be achieved in a simple manner by means of dipping, spraying or brushing.

In order to integrate the inking process seamlessly into the production process of the sealing tape rolls, the sealing tape is compressed before coloring to 10% to 60%, preferably 15% to 50% of its original thickness. Ideally, this happens when winding the foam to a sealing tape roll.

In order to achieve a uniform recovery over the entire width of the sealing tape, the colorant has as binder either a paraffin-based wax, grease, oil, a silane or a silicone, or it has an ethylene-vinyl acetate, a polyvinyl acetate, a polyurethane or a silicate on.

Also suitable as the color carrier substance are solvents, preferably dipolar solvents. These dissolve the ground easily and allow for their evaporation better attachment and bonding of the color to the substrate.

In order to add further functionalities to the sealing tape in addition to the sealing properties, the colorant may additionally comprise a fire retardant or a substance for protection against UV radiation.

Fig. 1

ist eine schematische seitliche Perspektivansicht des erfindungsgemäßen Dichtbands in einem komprimierten Zustand, wobei ein Abschnitt der gefärbten Seitenfläche vergrößert dargestellt ist;

Fig. 2

ist eine schematische seitliche Perspektivansicht des Dichtbands aus Fig. 1 in einem teilexpandierten Funktionszustand, wobei derselbe Abschnitt der gefärbten Seitenfläche vergrößert dargestellt ist wie in Fig. 1;

Fig. 3

ist eine Perspektivansicht einer Dichtbandrolle mit dem erfindungsgemäßen Dichtband;

Fig. 4

ist eine schematische vergrößerte Querschnittsansicht eines Schaumstoffs, aus der die Zellstruktur des Schaumstoffs ersichtlich ist; und

Fig. 5

ist eine mikroskopisch vergrößerte Ansicht einer eingefärbten Seitenfläche des erfindungsgemäßen Dichtbands, in der der Verbund von Farbflecken gezeigt ist.

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

Fig. 1

Figure 3 is a schematic side perspective view of the sealing tape of the invention in a compressed condition, with a portion of the colored side surface shown enlarged;

Fig. 2

is a schematic side perspective view of the sealing tape Fig. 1 in a partially expanded functional state, wherein the same portion of the colored side surface is shown enlarged as in Fig. 1 ;

Fig. 3

is a perspective view of a sealing tape roll with the sealing tape according to the invention;

Fig. 4

Fig. 12 is a schematic enlarged cross-sectional view of a foam showing the cell structure of the foam; and

Fig. 5

is a microscopically enlarged view of a colored side surface of the sealing tape according to the invention, in which the composite of color stains is shown.

The sealing tape according to the invention consists of a soft, resilient after compression foam. Polyethylene foam, particularly preferably polyurethane foam, may be mentioned as the foam material. The foam may be an open-cell foam with very low air resistance, as well as a nearly closed-cell foam with extremely low air penetration values. Even foams with air penetration values, which lie between the two extreme cases mentioned above, can be used in the context of the present invention. The foam can impregnated with a sticky impregnate, which increases the sealing properties of the foam and leads to a delayed recovery of the same after compression of the foam.

In Fig. 1 a short section of a sealing band of such a foam is shown schematically in side perspective view. A side surface 3 of the sealing tape is dyed with a colorant of any color. It is also possible to color both side surfaces 3, 4 with the colorant. Fig. 1 also shows a portion of the visible to the viewer surface area of the side surface 3 in a schematic microscopic magnification.

The side surfaces 3, 4 extend in the longitudinal direction of the wound usually to a sealing tape roll 9 sealing tape and form the lateral conclusion, as from Fig. 3 is apparent. The underside of the sealing tape is usually provided with a cover 10 (see Fig. 3 ) under which a self-adhesive layer may be located. When installed in a joint, the two side surfaces 3, 4 run transversely to the functional direction of the sealing band, with at least one colored side surface 3, 4 remaining visible to the viewer.

The sealing tape of Fig. 1 is in the compressed state, which is also in Fig. 3 is shown. According to the invention, the coloring agent is applied to at least one of the side surfaces 3, 4 of the compressed sealing tape by dipping, spraying or brushing. Application in this context preferably means the impregnation or wetting of an edge region of the side surface 3, 4 with the colorant up to a penetration depth of up to a few millimeters. In a central region 5 between the side surfaces 3, 4, for reasons of cost and for preventing a negative influence of the colorant on the overall behavior of the foam, preferably no coloration is present.

Microscopic magnification in Fig. 1 shows color spots 8 of different sizes, which are ideally represented as circular areas or ovals. The color stains 8 often deviate from these ideal shapes, although agglomerates, clusters and juxtapositions may also occur, as will be described in more detail below.

It should be noted that the enlarged illustrations in Fig. 1 and 2 in the same way schematically that the actual structure of the foam is not reflected. In reality, the color spots 8 deposit on cell webs 7 or cell walls of the foam material and arrest there due to the tackiness of the binder. A realistic representation of the cellular structure of a foam is out Fig. 4 seen.

The color spots 8 may be formed from pigments or dyes. Dyes are already dissolved in a solvent or binder, while pigments are largely insoluble. They are available as a grain in a mixture / recipe and are usually slightly larger than dyes. In the case of the use of pigments, a solvent or a binder is also used according to the invention in order to store them in the foam. Preferably used for coloring in nature occurring inorganic pigments, synthetically prepared inorganic or organic pigments or industrially produced dyes.

Suitable additives are defoamers, water repellents, wetting agents, drying agents, pigment distributors, fungicides, preservatives and pH buffer solutions. The colorant may additionally be accompanied by a fire retardant, for example an intumescent substance, or else an agent for protection against UV radiation. In addition, salts may be added to the colorant to aid in coloring. Furthermore, the colorant can be adjusted to acidic or alkaline.

During dyeing, an edge region of up to a few millimeters depth is soaked or wetted with the colorant such that the pigments or dyes accumulate on the cell webs 7 of the cell structure of the foam due to the sticky properties of the binder. The color spots 8 produced in microscopic side view usually have a lateral extent of between 0.01 mm to about 0.7 mm, wherein a lateral extent of a color spot 8 of 0.05 mm corresponds approximately to the perceptual limit of the human eye. In flat view, thus color spots 8 with an area of between 0.0001 mm ² to about 0.5 mm ² . The individual color spots 8 will in practice have all sorts of different sizes and shapes, also color spots 8 with less than 0.0001 mm ² or more than 0.5 mm ² may be present, but the clear majority of all color spots 8 is within the specified range. In any case, the average of the area of a color spot 8, averaged over all color spots 8, is between 0.0001 and about 0.5 mm ² , preferably between 0.0025 and 0.3 mm ² .

One recognizes in Fig. 1 in that different color patches 8 can also lie one behind the other and thus partially overlap. Due to the different sizes, in particular also the presence of color spots 8 of relatively small area, even when viewed under the microscope, a nearly complete coloration of the visible side surface area in the compressed state is achieved.

Fig. 2 shows the sealing tape Fig.1 in identical view, but with the sealing strip is in a part-expanded functional state. This partially expanded functional condition is within a range of between 25% and 60% of the maximum expansion of the sealing band. The in Fig. 1 In contrast, the compressed state shown corresponds to a compression of the sealing tape to 10% to 60%, preferably 15% to 50% of its original thickness, wherein the foam is compressed more and more here than in the partially compressed functional state.

It can be seen clearly that due to the expansion, in the present case, a part expansion by about 40% compared to in Fig. 1 shown compressed state, an expansion of the pores of the foam takes place in comparison to the compressed state and thus increase the distances between the individual color spots 8. Nevertheless, when viewed with the naked eye, the perception of a closed color surface remains. This is because the human eye can no longer distinguish the different color spots 8 because the gaps between the color spots 8 are so small that they are below the resolution limit of the human eye. During expansion, the surface of the foam expands accordingly, so that even deeper area of the sealing strip and thus deeper color spots 8 are visible, which contribute to the surface area visible from the side. Under the microscope it can be seen that the differently sized color spots 8 in side view together make up at least 60% of the total visible surface area.

Since the cell webs 7 ( Fig. 4 ) of the foam material also contribute to the overall visual impression, the basic color of the foam must be taken into account in the calculation of the desired hue. Preferably, therefore, relatively light shades, for example a light gray shade, are preferred for the foam material. To prepare for Underground and to reinforce the coloring effect achieved, this effect can also be improved by the temporal upstream coloring with a light base color (eg white) and the subsequent dyeing with the final desired color.

As from the microscopically enlarged view of a colored according to the invention side surface of a located in the recovered state sealing tape in Fig. 5 It can be seen, in practice, the individual color spots 8 to a composite as a larger color fabrics closely juxtaposed, which are difficult even under the microscope, also due to their three-dimensional structure, objectively divided into individual clearly defined color spots 8, so that partially contiguous color areas, such as color stripes along the cell webs 7 of the foam, can arise from a few millimeters in length.

As binders integrated in the colorant, e.g. aqueous acrylate dispersions, polyurethane dispersions, silicones, silicates, ethylene-vinyl acetates, polyvinyl acetates, waxes, linseed oils or casein in question. The proportion of the binder in the colorant need not be high due to the small size of the pigments or dyes, usually a proportion of the colorant of 10 wt.% Will be sufficient so that a permanent connection with the cell webs 7 of the foam material can be produced.

Furthermore, it is conceivable to bind dyes or pigments by means of a solvent to the sealing tape. Here, the surface of the foam or preferably already attached to the surface and dried impregnation is minimally dissolved. As a result, dyes or pigments are deposited on the sealing tape after evaporation of the solvent and without additional binder, where they are bonded superficially. Preferably, polar, such as dipolar, solvents, e.g. Alcohols used.

The production of the sealing tape according to the invention is carried out as follows. First, the foam material is conventionally made in wide (possibly impregnated) foam sheets which are wound on wide master rolls. These master rolls are severed at desired intervals along with the foam wound thereon, thereby creating narrow band width rolls 9 (see FIG Fig. 3 ). On the roll is the sealing tape in the in Fig. 1 illustrated compressed state. Preferably in this state is now the lateral coloring by dipping, spraying or brushing the at least one side surface 3, 4 of the sealing tape made, wherein the penetration depth of the colorant is preferably up to a few millimeters. The application method, the consistency of the colorant and the properties of the foam (eg pore size, tape thickness, degree of compression) are the determining parameters for the coloring. Subsequently, the sealing tape can be unwound from the sealing tape roll 9 and fed to its intended use. In this case, the sealing tape is preferably delayed after the release of the compression pressure in the in Fig. 2 shown partially expanded functional condition, which ensures the sealing of the joint in the construction sector.

In this way, a sealing tape made of soft, resilient foam is created, which can be used excellently for joints in the outdoor area and meets high aesthetic standards.

Claims (12)

1. Sealing tape made of soft foam which is resilient after compression, comprising two lateral surfaces (3, 4), at least one of the two lateral surfaces (3, 4) being coloured with a colourant in such a way that the colouration on the lateral surfaces (3, 4) in a partially expanded functional state of the sealing tape appears to the human eye as a continuous coloured surface, whereas no colouration is provided in a central region (5) between the lateral surfaces (3, 4), characterised in that an edge region of the at least one lateral surface (3, 4) of the sealing tape is coloured using the colourant to a depth of up to a few millimetres by dipping, spraying or spreading and, in a microscopic side view, comprises a network of a plurality of differently sized, mostly interconnected colour specks (8), the average area of a colour speck (8) in the partially expanded functional state of the sealing tape being between 0.0001 and 0.5 mm², and in that, in the partially expanded functional state of the sealing tape, the colour specks (8) in the edge region of the lateral surface (3, 4) together constitute, in a microscopic side view, at least 60 % of the overall visible surface area, the partially expanded functional state corresponding to an expansion of between 25 % and 60 % of the maximum expansion of the sealing tape.
2. Sealing tape according to claim 1, characterised in that the sealing tape consists of a foam having the property of delayed recovery after compression.
3. Sealing tape according to any one of the preceding claims, characterised in that the average area of a colour speck (8) in the partially expanded functional state of the sealing tape is preferably between 0.0025 and 0.3 mm².
4. Sealing tape according to any one of the preceding claims, characterised in that the colourant is formed in such a way that a uniform recovery of the sealing tape after compression over the width of the sealing tape is ensured.
5. Method for producing a sealing tape comprising the step of:

   - providing a sealing tape made of soft foam which is resilient after compression and has two lateral surfaces (3, 4);
   characterised by the following further steps:

   - compressing the sealing tape; and

   - colouring an edge region of at least one of the two lateral surfaces (3, 4) to a depth of up to a few millimetres by dipping, spraying or spreading with a colourant in such a way that the colouration on the lateral surface in a partially expanded functional state of between 25 % and 60 % of the maximum expansion of the sealing tape appears to the human eye as a continuous coloured surface, whereas no colouration is undertaken in a central region (5) between the lateral surfaces (3, 4), resulting in the sealing tape, in a microscopic side view, comprising a network of a plurality of differently sized, mostly interconnected colour specks (8), the average area of a colour speck (8) in the partially expanded functional state of the sealing tape being between 0.0001 and 0.5 mm², and in that, in the partially expanded functional state of the sealing tape, the colour specks (8) in the edge region of the lateral surface (3, 4) together constitute, in a microscopic side view, at least 60 % of the overall visible surface area.
6. Method according to claim 5, characterised in that before colouration the sealing tape is compressed to 10 % to 60%, preferably to 15 % to 50%, of its original thickness.
7. Method according to either claim 5 or claim 6, characterised in that the colourant and the colouration method are selected in such a way that the average area of a colour speck (8) in the partially expanded functional state of the sealing tape is preferably between 0.0025 and 0.3 mm².
8. Method according to any one of claims 5 to 7, characterised in that the colourant contains, as a binder, an acrylate dispersion, an ethylene vinyl acetate, a polyvinyl acetate, a polyurethane, or a silicate.
9. Method according to any one of claims 5 to 8, characterised in that the colourant contains, as a binder, a paraffin-based wax, fat, or oil, a silane or a silicate.
10. Method according to any one of claims 5 to 8, characterised in that the colourant contains a solvent, preferably a dipolar solvent.
11. Method according to any one of claims 5 to 10, characterised in that the colourant contains a flame retardant.
12. Method according to any one of claims 5 to 11, characterised in that the colourant contains a substance for protection against UV radiation.

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