LAYERED CONSTRUCTION HAVING AN ADHESIVE STRIP AND TWO LINERS

Abstract

Layer constructions allow an adhesive tape to be wound to form a spool simply and with relatively uncomplicated apparatus. At least one layered construction comprises: an adhesive tape comprising at least one outer layer of pressure-sensitive adhesive; a release liner lying on the outer layer of pressure-sensitive adhesive; and an interliner lying on the side of the adhesive tape opposite the outer layer of pressure-sensitive adhesive, at least the side of the interliner facing away from the adhesive tape being adhesively furnished, wherein all layers of the layered construction finish substantially flush with respect to each other. At least one spool comprising a spool core and the at least one layered construction wound crosswise in a plurality of plies on said core, and a method for producing the at least one spool are also disclosed.

Claims

1. A layered construction comprising an adhesive tape comprising at least one outer layer of pressure-sensitive adhesive; a release liner lying on the at least one outer layer of pressure-sensitive adhesive; and an interliner lying on the side of the adhesive tape opposite the at least one outer layer of pressure-sensitive adhesive, the side of the interliner facing away from the adhesive tape being adhesively furnished; wherein all layers of the layered construction finish substantially flush with respect to each other.

2. The layered construction of claim 1, wherein the interliner comprises a carrier layer comprising MOPP, a polyester, a polyamide, or paper.

3. The layered construction of claim 1, wherein the adhesive tape comprises a foam layer based on poly(meth)acrylate.

4. The layered construction of claim 1, wherein the side of the interliner facing away from the adhesive tape is formed by a poly(meth)acrylate-based or natural rubber-based pressure-sensitive adhesive.

5. A spool, comprising a spool core and the layered construction of claim 1, wherein the layered construction is wound crosswise in a plurality of plies on said core, wherein in the innermost ply, the adhesively furnished side of the interliner lies directly on the spool core, and in each ply, the adhesively furnished side of the interliner forms the inner side of the layered construction, being the side oriented to the spool core.

6. A method for producing the spool of claim 5, the method comprising providing the layered construction of claim 5 wound up to form a master roll; separating of the layered construction such that, from the web forming the master roll, a plurality of webs having a web width lower by comparison with the master roll are obtained; providing of spool cores; and winding of the webs onto respectively one spool core such that: a plurality of crosswise-overlapping plies are produced; in the innermost ply, the adhesively furnished side of the interliner lies directly on the spool core; and in each ply, the adhesively furnished side of the interliner forms the inner side of the layered construction, being the side oriented to the spool core.

Description

[0138] The layered construction of the invention is made clearer by FIG. 1, which shows, illustratively, a layered construction of the invention lying on a spool core, with the sequence of the individual layers shown being illustrative. The denotations in FIG. 1 are as follows:

[0139] 1adhesive tape [0140] 2release liner (RL) [0141] 3outer layer of pressure-sensitive adhesive (PSA-A) of the adhesive tape [0142] 4interliner (IL) [0143] 5carrier of the interliner (IL) [0144] 6adhesively furnished side of the interliner (IL), being the side facing away from the adhesive tape [0145] 7spool core

[0146] A further subject of the invention is a method for producing a spool of the invention, which comprises [0147] the providing of a layered construction of the invention wound up to form a master roll; [0148] the separating of the layered construction such that, from the web forming the master roll, a plurality of webs having a web width lower by comparison with the master roll are obtained; [0149] the providing of spool cores; and [0150] the winding of the webs onto respectively one spool core such that [0151] a plurality of crosswise-overlapping plies are produced; [0152] in the innermost ply, the adhesively furnished side of the interliner (IL) lies directly on the spool core; and [0153] in each ply, the adhesively furnished side of the interliner (IL) forms the inner side of the layered construction, being the side oriented to the spool core.

[0154] The method of the invention may be performed advantageously without the separate lamination of an interlinerwhich is broader by comparison with the adhesive tapeand therefore can be performed substantially more efficiently than conventional methods.

[0155] In an alternative method, the webs are wound onto the spool core in such a way that in the innermost ply, the release liner (RL) lying on the outer layer of pressure-sensitive adhesive (PSA-A) lies directly on the spool core and, correspondingly, in each further ply as well, it forms the inner side of the layered construction, being the side oriented to the spool core. Since in this case the adhesively furnished side of the interliner (IL) faces outward in the final ply, the spool would be wrapped with an additional release liner.

EXAMPLES

Test Methods

Test Method T1: Visual Evaluation

[0156] The adhesive tapes listed in table 1, each lined on one side with a release liner and on the opposing side with an interliner, were trimmed to the respectively specified width, from a master roll, and were level-wound into a spool, subject to the parameters specified in the table. The resulting spools were stored under the following conditions: [0157] 1 month at 23 C. [0158] 1 month at 40 C. [0159] 2 months at 40 C.

[0160] This was followed by a visual evaluation according to each of the following (negative) criteria: [0161] 1. does the spool have deviations from the originally cylindrical form? [0162] 2. do the spool cores project asymmetrically to left and right? [0163] 3. is the distribution of the wound tape over the spool width uneven (different distance between adjacent tape sections)? [0164] 4. have the outermost tapes slipped off of the spool edges/are they no longer in their original position?

[0165] If all of the questions received the answer no, in the visual evaluation was rated as ok, otherwise as not ok.

Test Method T2: Unwind Behavior

[0166] After the storage described in method T1, the spools were unwound on an Ehnert AWS18G unwinder without a contact roller and without utilizing the interliner winder; the unwind speed was 15 m/min.

[0167] The criteria evaluated in this instance were as follows: [0168] 5. was it possible to unwind the spooled tape uniformly and without force peaks, particularly at the points of directional change? [0169] 6. did the composite hold together (no unintended detachment of the liner)? [0170] 7. was it always possible to separate adjacent tape sections cleanly (no sticking of adjacent tape sections), particularly in the region of the change in winding direction (up to 5 instances of minimal, reversible clinging to one another are acceptable, but are noted in the table)? [0171] 8. were the interliner and release liner congruent on the adhesive tape? [0172] 9. were there no perceptible deviations in the distance between adjacent tape sections? [0173] 10. were release liner and interliner free from folds? [0174] 11. did the adhesive tape sections from the reversal points in the winding direction retain their curve shape (comparison of two strips, each 1 m long, from the spool center and from the turn point; evaluation of the parallelism when placed alongside one another)? [0175] 12. was it possible to remove the interliner, after unwinding, uniformly and without clattering?

[0176] If all of the questions received the answer yes, for the unwind behavior was rated as ok, otherwise as not ok. The deficiencies observed that were still acceptable are additionally set out in table 1.

[0177] The following adhesive materials were used as interliners (corresponding to interliner (IL)): [0178] Interliner 1 (IL1): adhesive tape tesa 64250 (single-sided acrylate adhesive tape with MOPP backing; available commercially; total thickness 80 m; tensile strength 100 N/cm) [0179] Interliner 2 (IL2): adhesive tape tesa 4360 (single-sided acrylate adhesive tape with PE backing; available commercially; total thickness 51 m; tensile strength 13 N/cm) [0180] Interliner 3 (1L3): adhesive tape tesa 50600 (single-sided silicone adhesive tape with PET backing; available commercially; total thickness 80 m; tensile strength 50 N/cm)

[0181] The following adhesive tapes were used: [0182] Adhesive tape 1: tesa ACX.sup.plus 7805 PV29 (double-sided acrylate foam tape, with release liner on one side; available commercially) in a width of 6 mm; compressive strength 46 N/cm.sup.2. [0183] Adhesive tape 2: tesa ACX.sup.plus 77115 PV28 (double-sided acrylate foam tape, with release liner on one side; available commercially) in a width of 10 mm; compressive strength 37 N/cm.sup.2. [0184] Adhesive tape 3: tesa ACX.sup.plus 7812 PV29 (double-sided acrylate foam tape, with release liner on one side; available commercially) in a width of 4 mm, compressive strength 46 N/cm.sup.2. [0185] Adhesive tape 4: tesa ACX.sup.plus 77811 PV 15 (double-sided acrylate foam tape, with release liner on one side; available commercially) in a width of 6 mm; compressive strength 16 N/cm.sup.2.

[0186] The respective structure was provided in the form of a master roll with adhesive tape and applied release liner and also interliner. The master rolls were unwound using a spooler, and slit. The resulting layered constructions, cut to the target width, were then wound using a winder to form level-wound spools; the respective parameters are reported in table 1.

TABLE-US-00001 TABLE 1 Inter- Running Adhesive liner Lay-off Winding length of Visual Unwind No. tape No. No. distance tension spool evaluation behavior 1 1 1 0.8 mm 190 cN/cm 900 lm ok ok 2 3 1 0.8 mm 190 cN/cm 900 lm ok ok 3 2 2 1.0 mm 190 cN/cm 500 lm ok ok (2 instances of slight pulling on directional change) 4 4 3 0.9 mm 190 cN/cm 700 lm ok ok (3 instances of slight pulling in internal wound plies)