Method for Producing an Adhesive Tape

Abstract

The invention relates to a method for producing an adhesive tape, by: providing a tapelike textile carrier (2),

applying a thickener (7) and separately aqueous dispersion-based adhesive (8) to the textile carrier (2), the thickener (7) and the aqueous dispersion-based adhesive (8) coming into contact with each other once applied, then drying the dispersion-based adhesive (8).

Claims

1. A method of producing an adhesive tape, comprising the steps of: providing a tapelike textile carrier, applying a thickener and separately an aqueous dispersion-based adhesive to the textile carrier, the thickener and the aqueous dispersion-based adhesive coming into contact with each other once applied, and then, drying the dispersion-based adhesive.

2. The method of claim 1, wherein, the thickener is applied on one side of the textile carrier and thereafter, the aqueous dispersion-based adhesive is applied to the thickener.

3. The method of claim 1, wherein, one side of the textile carrier is coated with the thickener and the aqueous dispersion-based adhesive is applied to another side of the textile carrier.

4. The method of claim 1, wherein, the thickener is applied over the full area of the textile carrier.

5. The method of claim 4, wherein, the dispersion-based adhesive is applied over the full area of the thickener.

6. The method of claim 1, wherein, a dual slot die is used in applying the thickener and the dispersion-based adhesive (8).

7. The method of claim 1, wherein, the dispersion-based adhesive has a viscosity of 0.2 Pa*s to 15 Pa*s5 Pa*s.

8. The method of claim 1, wherein, the thickener and the dispersion-based adhesive have similar viscosities, or the same viscosity.

9. The method of claim 1, wherein, the dispersion-based adhesive comprises a polymer dispersion, the polymer being synthesized from: 95.0 to 100.0 wt % of n-butyl acrylate and/or 2-ethylhexyl acrylate 0.0 to 5.0 wt % of an ethylenically unsaturated monomer having an acid function or acid anhydride function.

10. The method of claim 1, wherein, the thickener comprises ASE.

11. The method of claim 1, wherein, the thickener comprises at least one of: carboxymethylcellulose, 2-hydroxyethylcellulose, carboxymethyl-2-hydroxyethylcellulose, methylcellulose, 2-hydroxyethylmethylcellulose, 2-hydroxyethylethylcellulose, 2-hydroxypropylcellulose, 2-hydroxypropylmethylcellulose, or 2-hydroxybutylmethylcellulose.

12. The method of claim 1, wherein, the textile carrier comprises a drawn-loop knit, laid scrim, tape, braid, needle pile textile, felt, woven fabric or a nonwoven web.

13. The method of claim 6, wherein, the dual slot die has a slot with a width of 100 m to 300 m.

14. The method of claim 1, wherein, the adhesive tape is wound up to a roll.

15. The method of claim 1, wherein during the production of the adhesive tape, the textile carrier has a rate of advance in an advance direction (V) and a slot distance of the dual slot die are selected such that the dispersion-based adhesive is applied 0.1 to 10 s after the application of the thickener.

16. An apparatus for the production of the adhesive tape according to the method of claim 1, wherein the apparatus comprises: a coating roll with a longitudinal coating roll direction, a dual slot die having a longitudinal slot direction which is disposed along the longitudinal coating roll direction, wherein the apparatus is operable such that the textile carrier can be fed between the dual slot die and the coating roll, and a first slot die is in communication with a supply facility with a thickener, and a second slot die is in communication with a second supply facility with an aqueous dispersion-based adhesive.

17. The apparatus of claim 16, wherein, the first slot die is disposed ahead of the second slot die in reference to the advance direction (V).

18. The apparatus of claim 16, which further comprises: a drying facility for the adhesive tape present after the dual slot die in reference to the advance direction (V).

19. The apparatus of claim 16, wherein, the dispersion-based adhesive comprises a polymer dispersion, the polymer being synthesized from: 95.0 to 100.0 wt % of n-butyl acrylate and/or 2-ethylhexyl acrylate 0.0 to 5.0 wt % of an ethylenically unsaturated monomer having an acid function or acid anhydride function.

20. The apparatus of claim 16, wherein, the thickener comprises ASE.

21. The apparatus of claim 16, wherein, the thickener comprises at least one of: carboxymethylcellulose, 2-hydroxyethylcellulose, carboxymethyl-2-hydroxyethylcellulose, methylcellulose, 2-hydroxyethylmethylcellulose, 2-hydroxyethylethylcellulose, 2-hydroxypropylcellulose, 2-hydroxypropylmethylcellulose, or 2-hydroxybutylmethylcellulose.

Description

[0124] The invention is described with reference to a working example and two figures. In the case of the latter

[0125] FIG. 1 shows a sectional view of an apparatus for implementing the adhesive tape production method of the invention, and

[0126] FIG. 2 shows the adhesive tape produced by the method of the invention, in a lateral section

[0127] Depicted in FIG. 1 in a sectional view, schematically, is an apparatus for applying an adhesive layer 1 to a textile carrier 2. The apparatus comprises a coating roll 3, via which the textile carrier 2 is guided. The coating roll 3 is connected to a motor, which rotates the coating roll 3 and gives the textile carrier 2 an advance in an advancement direction V. The direction of rotation can be changed.

[0128] Besides the coating roll 3 there is a dual slot die 4. The coating roll 3 and the dual slot die 4 have the same longitudinal extent in their longitudinal direction L, which stands perpendicularly on the drawing plane. The dual slot die 4 here has a longitudinal extent of its two slots, which are of equal length, of 1600 mm. Other lengths are of course also possible.

[0129] The dual slot die 4 and the coating roll 3 are disposed parallel to one another. They are preferably at a distance from one another and between them form a slot 6 of constant width, through which the textile carrier 2 is passed. During the coating operation, the textile carrier 2 is drawn through the slot 6 and guided around the coating roll 3, from bottom to top right in FIG. 1. During the coating operation, a thickener 7 is first applied by a first slot die 7a to the side of the textile carrier 2 opposite from the coating roll 3. The height of the first slot die 7a is around 100 m, preferably exactly 100 m. The length of the first slot die 7a is 1600 mm.

[0130] A second slot die 8a, disposed successively in the advancement direction V of the textile carrier 2, allows a dispersion-based adhesive 8 to be applied to the thickener 7 which has been applied to an adhesive side 2a of the textile carrier 2. The second slot die 8a has a length of likewise 1600 mm and a height of 300 m. The thickener 7 is applied in the form of a thickener layer to the textile carrier 2, and the dispersion-based adhesive 8 is applied in the form of a dispersion-based adhesive layer to the textile carrier 2.

[0131] Both the thickener 7 and the dispersion-based adhesive 8 have virtually the same viscosity of =3 Pa.sub.-.sup.*-s. Applied as dispersion-based adhesive 8 is an acrylate adhesive diluted with water. The dispersion-based adhesive 8 is applied with a coat weight of 70 g/m.sup.2. The textile carrier 2 used is a PET web. The thickener 7 has been coated onto the PET web with a coat weight of 2 g/m.sup.2. The thickener used was Sera Print M-PHC. First of all, the thickener 7 sinks immediately into the textile carrier 2 on coating. As a result of the application of dispersion-based adhesive only a few microseconds after the application of thickener, the penetration of the carrier 2 by the thickener 7 is halted and the dispersion-based adhesive 8 undergoes virtually instantaneous thickening. This thickening takes place first of all on the layer side of the adhesive layer 1 facing the carrier 2, and so here as well any substantial penetration of the dispersion-based adhesive 8 into the carrier 2 is prevented. Arranged downstream of the coating roll 3 in the advancement direction V is a drying facility, which is not shown here, but which dries the applied adhesive layer 1that is, the dispersion-based adhesive 8 thickened with thickener 7and provides the completed adhesive tape provided with an adhesive layer 1.

[0132] Shown in FIG. 2, in a section in the cross direction (transverse direction), is the adhesive tape, consisting of a woven fabric carrier 2, on one side of which a layer of a self-adhesive coating 1 based on an acrylate dispersion has been applied. The adhesive has been absorbed to an extent of only 15% into the carrier (21), this producing optimum anchoring and at the same time improving the hand tearability of the carrier.

LIST OF REFERENCE SYMBOLS

[0133] 1 adhesive layer [0134] 2 textile carrier [0135] 2a adhesive side [0136] 3 coating roll [0137] 4 dual slot die [0138] 6 slot [0139] 7 thickener [0140] 7a first slot die [0141] 8 dispersion-based adhesive [0142] 8a second slot die [0143] L longitudinal direction [0144] V advancement direction