CA2339601C

CA2339601C - Self-adhesive sheet

Info

Publication number: CA2339601C
Application number: CA002339601A
Authority: CA
Inventors: Reto Sieber; Marco Sieber; Patrick Vandeweerdt
Original assignee: Uzin Tyro AG
Current assignee: Uzin Tyro AG
Priority date: 1998-08-07
Filing date: 1999-08-06
Publication date: 2009-10-20
Anticipated expiration: 2019-08-06
Also published as: HUP0103456A2; WO2000008111B1; WO2000008111A1; PL345855A1; JP2002522589A; DE59904769D1; EP1117746A1; NO20010623D0; PL191256B1; NO324282B1; CZ300970B6; DK1117746T3; CA2339601A1; HU227411B1; CZ2001432A3; HUP0103456A3; EP1117746B1; DE19835919A1; NO20010623L; AU5511299A

Abstract

Described is a self-adhesive sheet for bonding and residueless detachment of a floor covering, especially a carpet, to and from a floor, especially parquet, having a backing layer made in particular of polymer film, which is coated on a top surface, facing the floor covering, and on a bottom surface, facing the floor, with a pressure-sensitive adhesive coating and, it being possible, but not mandatory, for the top surface at least to have a textile structure, the pressure-sensitive adhesive coating having a different adhesive strength on the two surfaces, such that the pressure-sensitive adhesive coating and/or the adhesive strength on the bottom surface is a fraction of that on the top surface and at least on the bottom surface is of substantially planar design.

Description

SELF-ADHESIVE SHEET

The invention relates to a self-adhesive sheet for bonding a floor covering to a floor.
Already known are self-adhesive tapes and sheets which have a pressure-sensitive adhesive coating applied to both surfaces of a backing layer. Either the backing layer of the self-adhesive tapes is itself designed as backing fabric, or a fabric is applied to the backing layer in order to obtain dimensional stability.
The pressure-sensitive adhesive coating has different adhesive strengths on the two surfaces of the backing layer. The adhesive strengths of the pressure-sensitive adhesive coating are chosen so that the top surface, facing the floor covering, has a higher adhesive strength than the bottom side, which faces the floor.
The application rates at which the pressure-sensitive adhesive coatings are commonly used, especially on the bottom surface, are in the region of 100 g/mz; the lowest are situated in the region of 70 g/m2, and virtually no manufacturer uses application rates below 70 g/m2.
The intention of the different pressure-sensitive adhesive coatings and/or adhesive strengths is that the floor covering, a carpet for example, should on the one hand adhere well to the floor, parquet for example, and on the other hand should be releasable without residue from the floor, together with the self-adhesive tape adhering to the floor covering. In order to ensure secure adhesion both to the floor covering and to the floor during laying, the conventional self-adhesive tapes, however, since they are generally not applied flatly, only have a small difference in the pressure-sensitive adhesive coating and/or in the adhesive strength of the two surfaces. As a result of this, however, there is a risk that, if bonding to the floor is excessive, part of the pressure-sensitive adhesive will remain adhering to the floor, or that, during detachment, the self-adhesive tape will tend to part from the floor covering rather than from the floor. Accordingly, residueless detachment is not guaranteed under all conditions. It is true that the self-adhesive tapes being used include those whose adhesiveness differences are brought about on the respective surfaces by the structural differences which exist owing to the unevenness of the backing fabric, i.e. the self-adhesive tapes have a "rough" surface of lower adhesiveness and a "smoother" surface of greater adhesiveness. However, it is not possible with this design either to guarantee residueless detachment of the floor covering from the floor under all conditions, owing to the pointwise loads on the "rough" surface and the associated centres of adhesion between self-adhesive tape and floor.

Some embodiments of the invention are therefore based on the object of providing a self-adhesive sheet which, under essentially all conditions, ensures both secure adhesion of the floor covering with the floor and residueless detachment of the floor covering from the floor, and so offers ease of handling.

In accordance with one aspect of the invention, there is provided self-adhesive sheet for bonding a floor covering, to a floor, having a backing layer which is coated on a top surface, facing the floor covering, and on a bottom surface, facing the floor, with a pressure-sensitive adhesive coating, the pressure-sensitive adhesive coating having a different adhesive strength on the two surfaces and the adhesive strength on the bottom surface is lower than that on the top surface, wherein the backing layer comprises a polymer film and the pressure-sensitive adhesive coating at least on the bottom surface is of planar design, and wherein the self-adhesive sheet is designed with a minimum width of 350 mm for extensive coverage of the floor to be covered with the floor covering.

The self-adhesive sheet of an embodiment of the invention is used to bond a floor covering, especially a carpet, to a floor, especially parquet.

The self-adhesive sheet has a suitable backing layer. The backing layer might comprise polymer film, e.g, propylene or polyethylene film, although in principle it is also possible to use any other suitable material, such as rubber, latex, or the like.

At least on the top surface, facing the floor covering, the backing film may have a fabric which serves in particular to maintain the dimensional stability of the self-adhesive sheet during laying and during detachment.
The fabric may also be disposed on the bottom surface, facing the floor, or on both surfaces. The fabric is formed by threads of suitable material of tensile strength.

Both surfaces might have a pressure-sensitive adhesive coating, the pressure-sensitive adhesive coating and/or the adhesive strength on the bottom surface being only a fraction of that on the top surface. For this purpose, it is possible to use pressure-sensitive adhesives having different bond strengths on each of the two surfaces, or the same pressure-sensitive adhesive on each surface.

As the pressure-sensitive adhesive it has been found appropriate to use an acrylic dispersion enriched with resins and with UV protection and ageing protection contained therein, althouqh it is also possible to use any other suitable pressure-sensitive adhesive.
The pressure-sensitive adhesive coating may be applied flatly; however, a pressure-sensitive adhesive coating arranged substantially in the form of stripes on the surfaces, with adhesive-free spaces in between, is also possible. The combination of two-dimensional application and striped application on one of the surfaces, or the combination thereof on one of the surfaces, is likewise possible.

At least the bottom surface with the significantly reduced pressure-sensitive adhesive coating might be of substantially planar design. The top surface as well may be of substantially planar design.
The design of the self-adhesive sheet with a fraction of the pressure-sensitive adhesive coating on the bottom surface, owing to the relatively low level of pressure-sensitive adhesive coating and{or adhesive strength, offers particularly reliable and residueless detachment of the floor covering and/or the self-adhesive sheet adhering to it. Since the self-=53088=1 adhesive sheet adheres securely to the floor covering because of the fact that the adhesive strength on the top surface is substantially greater in comparison to the bottom surface, easy detachment of the floor covering with the self-adhesive sheet adhering to it is possible. In addition, the substantially planar bottom surface of the self-adhesive sheet, despite the relatively low level of pressure-sensitive adhesive coating and/or adhesive strength, produces secure bonding of the floor covering to a floor, especially to smooth parquet, since the bond is not simply pointwise, as in the case of self-adhesive tapes having structured bottom surfaces. Since, owing to the substantially planar bottom surface, no centres of adhesion are produced, which because of their small areas do not offer secure bonding but instead adhere pointwise more strongly to the floor, the guarantee. of secure bonding is supplemented by that of reliable detachment as well.
In some embodiments, the self-adhesive sheet is designed so that its length and width are such that, in contrast to conventional self-adhesive tapes, it extensively covers substantially the entire floor to be covered with the floor covering. The length is chosen in accordance with the requirements of the spatial circumstances and the ease of processing.
As far as the width is concerned, arange from 350 to 2000 mm is used in some embodiments for reasons of ease of processing and practicability. A width range of from 500 to 1500 mm, and possibly to a range from 600 to 1000 mm might also be used. Of course, given corresponding spatial circumstances, the lengths could be chosen within these ranges.

The extensive design of the self-adhesive sheet, like the substantially planar shaping of the bottom surface, even though the pressure-sensitive adhesive coating and/or the adhesive strength of this surface is only a fraction of that of the top surface, offers- particularly secure adhesion of the floor covering to the floor, since in this way a large adhesion area is obtained, in contrast to conventional self-adhesive tapes.
Since in each case it is possible to apply pressure-sensitive adhesives having different bond strengths to the surfaces, it is not isolely the application rate of the adhesive that is responsible for the inventively different adhesive strengths, but also the different bond strengths of the pressure-sensitive adhesives used.
As a generally valid measurement technique for the adhesive strength of a pressure-sensitive adhesive coating, the measurement of the adhesive force in accordance with DIN 1939 is used. With this technique, a measurement is made of the force required to peel off the self-adhesive sheet, which' is provided with the pressure-sensitive adhesive coating under investigation, having a defined bond strength and a defined application rate. In accordance with the test standard, the width of the self-adhesive sheet is 25 mm and its bond partner is a steel surface.
An adhesive force of the pressure-sensitive adhesive coating of the bottom surface, measured in accordance with DIN 1939, is in a range from 0.8 to 5 N in some embodiments. A range from 1.5 to 3 N, and possibly an adhesive force range from 2.0 to 2.6 N is provided in some embodiments.

For' the adhesive force of the pressure-sensitive adhesive coati.ig of the top surface, measured in accordance with DIN 1939, a range of from 30 to 60 N
is provided in some embodiments.
In one embodiment of the invention, the different _ pressure-sensitive adhesive coating and/or the different adhesive strength or adhesive force of the two surfaces is brought about by means of different adhesive application rates, the top surface with the greater adhesive strength having a higher adhesive application rate than t.he bottom surface.
In another embodiment, the adhesive application rate on the top surface is in the range from 100 to 250 g/mz and on the bottom surface is in the range from 5 to 40 _g/m2. For the bottom surface, a range from 8 to 20 g/m2 is most preferred.
As already mentioned, different pressure-sensitive adhesives with different bond strengths may be used on each of the two surfaces, or the same pressure-sensitive adhesive may be used on each surface. The figures above relate to the case where the same pressure-sensitive adhesive is applied to the top and to the bottom surface.
The pressure-secisitive adhesive coating may he applied flatly; however, a pressure-sensitive adhesive coating arranged substantially in the form of stripes on the surfaces, with adhesive-free spaces in between, is also possible. The combination of two-dimensional application and striped application on one of the surfaces, or the combination thereof on one of the surfaces, is likewise possible. The stated adhesive application rates relate in one of these cases only to the surface regions provided with a pressure-sensitive adhesive coating.
In a further embodiment of the invention, the textile structure, on at least the top surface of the backing layer of the self-adhesive sheet, comprises threads of suitable material of tensile strength, such as, in particular, cotton, plastic, or the like, in a wide-meshed arrangement.
The arrangement may adopt any substantially wide-meshed design; particular preference. is given to threads arranged at right angles to one another and lying parallel in therespective_direGtion. The threads may be aligned in the respectivedirections parallel to the side edges of the-self-adhesive sheet, or else may form any desired angle thereto.

53088-.1 An embodiment in which the textile structure has threads running parallel and also threads arranged rhomboidally thereto at an obtuse angle is also contemplated.
The respective thread spacing of the textile structure is between 3 and 30 mm in some embodiments.

The textile structure may comprise a fibre web or else a reticularly spun structure in which the threads consist of fine single filaments spun together with one another. The threads of the textile structure are located on at least the top surface of the backing layer and are embedded in, and substantiall,y surrounded by, the pressure-sensitive adhesive layer, so that the corresponding surface of the self-adhesive sheet as well is substantially planar in design.
The wide-meshed textile structure ensures the dimensional stability of the self-adhesive sheet, with the substantially planar design' of the corresponding surface also remaining substantially maintained. This facilitates the reliable detachment of the floor covering from the floor, since, accordingly, during detachment, the self-adhesive sheet adheres to the floor covering securely and with dimensional stability.
By virtue of the parallel and also rhomboidal arrangement of the threads, an additional dimensional stability is produced in the oblique direction, i.e. in the direction of the rhomoidally arranged threads. This additional stability is of' particular advantage when the floor covering is removed obliquely (in relation to the threads arranged parallel to the edges) and offers additional reliability for the residueless detachment from the floor.
In order to make it particularly easy to handle the self-adhesive sheet before and during laying and bonding of a floor covering to a floor, in a further embodiment the self-adhesive sheet, at least 53088=1 on the top surface, has aremovable cover film for covering the pressure-sensitive ddhesive coating.
It is also possible for there to be a removable cover film additionally, or only, on the bottom surface. Owing to the substantially lower adhesive strength of the bottom surface, however, this is not absolutely necessary.
The cover film comprises a conventional, silicone-treated release paper, which bears with virtually no gap against the corresponding surface, adhering but removable, in some embodiments.
For the purpose of transportation, the self-adhesive sheet may be in roll form.
A self-adhesive sheet of embodiments of the invention might be used as follows:

The entire floor is covered with the self-adhesive sheet. The bottom surface of reduced adhesive strength is directed towards the. floor. During this procedure, the top surface could be covered with the cover film. Then the floor covering is laid on provisionally, and cut to size if necessary.
Subsequently, part of the floor covering is folded back again and the cover film is removed on this part of the self-adhesive sheet. The folded-back part of the floor covering is folded down again onto the top surface of greater adhesive strength, and is pre'ssed on i=f necessary. The same procedure is followed - with the remaining parts of the floor covering, until the entire floor covering has been extensively bonded to the floor.
All that is required for the residueless detachment of the floor covering is to pull it up from the floor. During this operation, the self-adhesive sheet parts from the floor and remains adhering to the floor covering. If it is desired to reuse the floor covering, with the self-adhesive sheet now -already adhering to it, the bottom surface, provided with pressure-sensitive adhesive coating, can be protected = 53088-.Z

with a suitable cover film as the floor covering is rolled up_ An alternative option to the above-described self-adhesive sheet with a textile structure, arranged at least on the top surface, for providing dimensional stability is a self-adhesive sheet without a textile structure.
For this purpose, however, a particularly suitable backing layer, possessing tensile'strength and stretch resistance, is required in order to maintain the dimensional stability. Such a layer may comprise the materials already mentioned above for a backing layer, although the thicknesses chosen must usually be greater 'than in the case of a self-adhesive sheet with an additional textile structure.
A11 of the above remarks, described embodiments, material, numerical and range data, and processes, with the exception of those points relating specifically to the textile structure, are also intended to apply to the self-adhesive sheet without a textile structure.

Claims

CLAIMS:

1. Self-adhesive sheet for bonding a floor covering to a floor, having a backing layer which is coated on a top surface, facing the floor covering, and on a bottom surface, facing the floor, with a pressure-sensitive adhesive coating, the pressure-sensitive adhesive coating having a different adhesive strength on the two surfaces and the adhesive strength on the bottom surface is lower than that on the top surface, wherein the backing layer comprises a polymer film and the pressure-sensitive adhesive coating at least on the bottom surface is of planar design, and wherein the self-adhesive sheet is designed with a minimum width of 350 mm for extensive coverage of the floor to be covered with the floor covering.

2. Self-adhesive sheet according to Claim 1, wherein the self-adhesive sheet has a textile structure at least on the top surface.

3. Self-adhesive sheet according to Claim 2, wherein the textile structure has threads in a wide-meshed arrangement.

4. Self-adhesive sheet according to Claim 3, wherein the textile structure has threads running parallel in a wide-meshed arrangement and also threads arranged rhomboidally at an obtuse angle thereto.

5. Self-adhesive sheet according to any one of Claims 2 to 4, wherein the textile structure has threads in a thread spacing of from 3 to 30 mm.

6. Self-adhesive sheet according to any one of Claims 1 to 5, wherein the adhesive strength of the bottom surface features an adhesive force (measured in accordance with DIN 1939) in the order of magnitude of from 0.8 to 5 N.

7. Self-adhesive sheet according to any one of Claims 1 to 6, wherein the different adhesive strength of the two surfaces is brought about by different adhesive application rates, the surface with the greater adhesive strength having a higher adhesive application rate.

8. Self-adhesive sheet according to any one of Claims 1 to 7, wherein the pressure-sensitive adhesive coating comprises pressure-sensitive adhesives different in each case on the top and on the bottom surface respectively.

9. Self-adhesive sheet according to Claim 7 or 8, wherein the adhesive application rate on the top surface is in the range from 100 to 250 g/m2 and on the bottom surface is in the range from 5 to 40 g/m2.

10. Self-adhesive sheet according to any one of Claims 1 to 9, wherein there is a removable cover film on at least the top surface.

11. Self-adhesive sheet according to any one of Claims 1 to 10, wherein the width of the self-adhesive sheet is in a range from 350 mm to 2000 mm.

12. Self-adhesive sheet according to any one of Claims 1 to 11, wherein the floor covering is a carpet.

13. Self-adhesive sheet according to any one of Claims 1 to 12, wherein the floor is a parquet floor.

14. Self-adhesive sheet according to Claim 6, wherein the adhesive force is in the order of magnitude of from 1.5 to 3 N.

15. Self-adhesive sheet according to Claim 6, wherein the adhesive force is in the order of magnitude of from 2.0 to 2.6 N.

16. Self-adhesive sheet according to Claim 9, wherein the application rate on the bottom surface is in the range from 8 to 20 g/m2.

17. Self-adhesive sheet according to Claim 11, wherein the width of the self-adhesive sheet is in the range from 500 mm to 1500 mm.

18. Self-adhesive sheet according to Claim 11, wherein the width of the self-adhesive sheet is in the range from 600 mm to 1000 mm.