Adhesive tape and its use

p0001The invention relates to an adhesive tape for the flying reel change of nonpolar flat web material wound on reels according to the features of the preamble of the main claim, as well as to a method for the flying reel change of nonpolar flat web material wound on reels.

p0002In the processing of flat web material (paper, film, nonwoven, or the like), the flying reel change is a common method for replacing an old, nearly unwound roll with a new roll without having to stop the fast running machines. In such flying roll changes, adhesive adhesive tapes are frequently used to connect the end of the old web to the beginning of the new web.

p0003The implementation of a flying reel change (also called "dynamic reel change") takes place in the film and fleece processing industry for materials with non-polar surfaces according to two different methods.

p0004In the first method, double-sided self-adhesive self-adhesive tapes are adhesively bonded (usually straight, or W-shaped or V-shaped) to the web beginning of the web of the new roll in an advantageous arrangement, and the web material which exceeds the adhesive tape is severed. In addition, the beginning of the web of the new roll is fixed to the underlying winding of the new roll with so-called stopping labels to prevent the web from being unwound when the new roll is accelerating to the peripheral speed of the old roll. A disadvantage of this method is that the preparation of the rollers is very time-consuming and the gluing requires the use of specialist forces. Moreover, the method does not always lead to the desired results since the adhesive bonds thus achieved are relatively thick due to the layering of web material, holding labels and adhesive strips. Furthermore, especially in the case of thin flexible web materials, it may occur that, at the beginning of a new web, protuberances occur in the web material as a result of the oppositely directed air stream occurring during rotation, which can generally lead to poor adhesion of the webs.

p0005In the second known method, a self-adhesive self-adhesive tape is glued overlappingly and in a straight line underneath the free end of the uppermost web of the new roll so that the adhesive side faces outwards and is only partially covered by the new web. The exposed portion of the outwardly facing adhesive side is adhered to the web of the old roll. In order to prevent an unwinding of the web during the acceleration of the new roll to the surface speed of the old roll, a liquid is introduced between the uppermost winding of the new roll and the underlying winding, so that the upper winding on the underlying winding passes through The capillary forces are fixed. The disadvantage of this method is the fact that this method also requires the use of specialist personnel and does not always lead to technically advantageous results, since the efficiency of fixing the web material by a liquid depends on many parameters, for example the surface energy, flexibility and the basis weight of the film material The polarity, viscosity, density, as well as the layer thickness, area and the shear behavior of the liquid film. A decisive disadvantage of this method is, furthermore, that the web speed during roll changing must not be too high and, furthermore, contamination of the system and of the web material due to the liquid used.

p0006The above process is also used in the papermaking industry. There, a further development of the first method represents the splicing method (splicing method) in which the fixation-serving fix is ​​integrated into the self-adhesive tape connecting the paper webs. After joining the webs, the fixative carrier is split, so that a part of the splittable carrier remains on the self-adhesive tape connecting the webs (ie, on the upper winding) while the other part remains on the underlying winding. The term "cleavable" means those carriers which can be cleaved parallel to their area expansion, and in particular those carriers which, in turn, actually split according to the requirements in a splicing process.

p0007Many products are known in the papermaking industry to carry out this process. So, for example,<patcit id="pcit0001" dnum="DE19632689A2"><text>DE 196 32 689 A2</text></patcit> An adhesive tape which, in addition to the main carrier, is equipped with a splittable paper carrier. In the case of the dynamic stresses when connecting the webs of both rollers, the paper carrier splits open and, with its residues, covers the adhesive compound used for fixing in a non-adhesive manner, which otherwise remains open in the case of other adhesive tapes.<patcit id="pcit0002" dnum="DE19902179A1"><text>DE 199 02 179 A1</text></patcit> Also discloses such an adhesive tape in which the splittable paper carrier is offset from the main carrier in order to prevent the occurrence of tears under load.

p0008The <patcit id="pcit0003" dnum="EP1342684A2"><text>EP A2 1 342 684</text></patcit> Describes an adhesive tape for the flying reel change of flat web material wound on rolls, with adhesive front side and non-adhesive rear side, as well as two longitudinal edges, with a main carrier which is coated on one side with a self-adhesive substance at the front side; a part of the non-adhesive rear side is equipped with at least one self-adhesive system , As well as a splice method for the flying reel change of flat web material wound on reels.

p0009In order to improve the flying reel change in the film and nonwovens processing industry, it would be desirable to be able to use adhesive tapes which are similar in structure to those already known from the papermaking industry. This is particularly the case for film and non-woven materials with non-polar surfaces. Such nonpolar surfaces occur in materials with low surface energy, for example, in polyethylene, in polypropylene, in polyethylene terephthalate (PET), or in polymer-coated papers. A surface energy is low when it is 50 mN / m or less. For such nonpolar surfaces, self-adhesive compositions are required, which are highly tacky and, at the same time, are highly tacky. The high adhesive strength and high tack-sensitivity (the so-called "tack") required for this purpose can usually be obtained by increasing the flowability of the adhesive composition.

p0010However, conventional high-tack and high-tack adhesive compositions are badly or not at all suitable for the flying roll change in the case of non-polar film and non-woven materials in the case of a splicing process. The increase in the adhesive strength and the tack of an adhesive composition is accompanied by an increase in its flowability. As a result of the high flowability, such an adhesive mass is laterally expressed from the adhesively finished cleavable system and can even penetrate into the cleavable carrier, which can lead to a blocking of the cleavable system and to a failure of the splice connection. Furthermore, it is disadvantageous that the flowable adhesive compounds pass out of the adhesive joint during the splicing operation, and thus, after the splitting of the splittable carrier, adhesive-adhesive can remain uncovered in the system.

p0011Accordingly, the object of the invention was to provide an adhesive tape having at least one upper self-adhesive composition, a cleavable carrier, and a lower self-adhesive composition on the lower side of the splittable carrier which is suitable for flying web changes at high web speeds of unpolar flat web material wound on rollers .

p0012The object could be surprisingly achieved by an adhesive tape which is suitable for the flying roll exchange of flat web material wound on rollers with nonpolar surfaces, in particular polyolefinic substrates, and in which a self-adhesive composition which is free of silicone is provided with an adhesive force on a polyethylene adhesive base of 1 , 5 N / cm or more (test method tesa test A) and a tack strength corresponding to a rolling path length of 50 mm or less (tesa test D method), and in which a self-adhesive composition having an adhesive force on a polyethylene adhesive base of 1.5 was used as the lower self- N / cm or more (test method tesa test A) and a complex viscosity of 10,000 Pa · s or more at 1 rad / s and 40 ° C (test method tesa test F). For the f lying roll change, it is particularly advantageous if the tack of the upper self-adhesive composition to a rolling distance of 50 mm or less equivalent (measurement method tesa test D).

p0013The upper self-adhesive composition is a self-adhesive composition based on a mixture of several styrene block copolymers containing at least one diblock copolymer with one of the styrene-based blocks, the styrene content being at least 25% by weight and / or the diblock content being at least 40% by weight Block copolymer total.

p0014A resin-modified acrylate composition or a self-adhesive composition which is identical to the upper self-adhesive composition is used as the lower self-adhesive composition.

p0015The upper self-adhesive composition serves, in the splicing process, to connect the upper side of the adhesive tape according to the invention to the beginning of the web of the new roll and to the almost unwound path of the old roll, whereby the webs of both rolls are connected to one another via the adhesive tape. The lower self-adhesive composition serves to connect the underside of the adhesive tape according to the invention to the second-top winding, whereby the uppermost and the second-to-second winding of the new roll are first connected to one another via the adhesive tape. In the further course of the splicing process, the splice of the upper two windings of the roller is separated again in the course of splitting the splittable carrier in such a way that the adhesive regions of the upper self-adhesive composition and the lower self-adhesive substance remote from the upper side of the respective winding are non-adhesive from the now split carrier Remain covered.

p0016The concrete embodiment of the upper self-adhesive composition and of the lower self-adhesive composition with regard to its adhesive strength, tack and viscosity are of particular importance for the invention. The choice according to the invention of the complex viscosity of the lower self-adhesive composition results in a cold flow of the lower self-adhesive composition being prevented. As a result, the self-adhesive substance on the lower side of the splittable carrier can not emerge from the adhesive joint and stick to the upper side of the splittable carrier, thus avoiding blockage of the carrier and the system also remaining capable of cleavage.

p0017For the upper self-adhesive composition, it is particularly advantageous to choose such a mass which meets the requirements for a film splicing process. It is advantageous to have a sufficient tack (tack) in order to be able to handle the splicing process on non-polar materials, in particular polyolefinic substrates, should not shear off from such substrates in the process, thus preferably having a good shear strength thereon and developing sufficiently good adhesive forces on the polyolefinic material .

p0018The adhesive strength was determined as follows (tesa test A): A polyethylene plate, which had been produced as a test plate by injection molding from HDPE granules GC7260 company Basell, was used as a defined adhesive base (adhesive plate). Before a measurement, this plate was cleaned with ethanol. A standard polyester support having a thickness of 23 μm was coated on one side with the respective self-adhesive composition as a sample to be examined (self-adhesive coating order: 50 g / m²). A 20 mm wide strip of the coated standard polyester support was pressed onto the adhesive base under load (2 kg). Immediately following this, the adhesive tape was peeled off at an angle of 180 ° from the substrate at a speed of 300 mm / min and the force required for this at room temperature was measured. The measured value (in N / cm) was the average of three individual measurements. A commercial test adhesive tape for the testing of non-adhesive coatings (type "tesa 7475" from tesa AG; adhesive force on steel according to the specification: 31.25 N / 25 mm) was tested according to this measuring procedure for the calibration of the "tesa Test A" The adhesive force determined on the polyethylene test panel was 4.5 N / cm. Comparative investigations were carried out on steel instead of on polyethylene with the identical test parameters (test A2).

p0019The determination of the tack tack was carried out as follows (tesa test D): The so-called rolling ball tack was measured as a measure of the tack tack at a very short contact time. A standard polyester support having a thickness of 23 μm of the respective self-adhesive composition was coated on one side as a sample to be examined (self-adhesive coating amount: 50 g / m²). An approximately 10 cm long strip of the adhesive tape was attached horizontally on the test plane with the adhesive side facing upwards. A sample ball made of steel (diameter: 11 mm, mass: 5.6 g) was cleaned with acetone and cooled to room temperature for 2 h (temperature: 23 ° C. +/- 1 ° C., relative humidity: 50% +/- 1% ). For measurement, the steel ball was accelerated by rolling out a 65 mm high ramp (inclination angle: 21 °) in the gravitational field of the earth. From the ramp, the steel ball was directed directly onto the adhesive surface of the sample. The distance traveled on the adhesive to the stop of the ball was measured. The roll length determined in this way serves as an inverse measure for the tack tack of the self-adhesive composition (ie the shorter the roll distance, the higher the tack tack and vice versa). The respective measured value (as length data in mm) resulted from the mean value of five individual measurements.

p0020The determination of the complex viscosity was carried out as follows (tesa test F): The respective pressure-sensitive adhesive composition obtained was obtained as a cylindrical-round sample body having a diameter of 25 mm and a height of 0.8 mm in a deformation-controlled rheometer (type RDA III, Rheometrics Scientific, plate-plate geometry, measuring head: 2000 g Bendix) (preloaded with an axial force of 3 N). The dynamic measurement was carried out at 40 ° C. in the room climate (normal conditions) and a 3% deformation of the sample body in the frequency range from 0.1 to 500 rad / s as a complex viscosity η *. The numerical value [in Pa · s] as "complex viscosity" is the amount of the complex viscosity measured in the low-frequency range (1 rad / s) and at 40 ° C.

p0021It is advantageous for the adhesive tape according to the invention to use a self-adhesive composition which has an adhesive force on a polyethylene adhesive base of 3.0 N / cm or more (test method tesa test A) as the upper self-adhesive composition and / or as the lower self-adhesive composition Is particularly advantageous when the adhesive force on a polyethylene adhesive base is 5.0 N / cm or more. This results in a particularly efficient adhesion of the adhesive tape to the unpolar flat web material to be connected, which further improves the durability of the connection and thus the overall efficiency of the splicing process.

p0022Furthermore, it is advantageous if a self-adhesive composition is used as the upper self-adhesive composition, which has a tacking tack corresponding to a rolling path length of 40 mm or less (test method tesa test D), wherein it is particularly advantageous if this roll distance 20 mm is used as a measure of the tack tack Or less. This results in a particularly high efficiency in connecting the webs by combining both rotating rollers.

p0023The upper self-adhesive compositions used are those based on styrene block copolymers. Copolymers are particularly suitable according to the invention which are formed from polymer blocks made from a vinylaromatic compound, particularly from styrene (A blocks), and from polymer blocks formed by polymerization of 1,3-dienes (B blocks), for example butadiene or isoprene Or a copolymer. The said copolymer may, for example, be one of the abovementioned compounds butadiene and isoprene. Mixtures of different styroblock copolymers are used. Products which are partly or completely hydrogenated can also be used.

p0024Advantageously used for block copolymer mixtures are, as one component, block copolymers which have a linear ABA structure. Linear multiblock copolymers can also be advantageously used. Particularly advantageously applicable are block copolymers of radial shape and star-shaped multiblock copolymers.

p0025As a further component, AB diblock copolymers are preferably used, in particular those based on the abovementioned A and B block monomers.

p0026According to the invention, a self - adhesive composition based on a mixture of a plurality of styrene block copolymers is used as the upper self - adhesive composition (1, 11), in which at least one of the copolymers is a diblock copolymer with one of the styrene - based blocks, the styrene content being at least 25% by weight and / or Diblock content is at least 40% by weight, based on the total block copolymer quantity.

p0027Two S-block-containing (SIS) -styrene-isoprene-styrene copolymers having the abovementioned styrene and / or diblock fractions, such as are commercially available under the trade name Europrene® SOL T-192, are, for example, suitable as the upper self-adhesive composition EniChem (styrene content 25% by weight, diblock coat 23% by weight) are commercially available.

p0028Adhesives which have at least a block copolymer mixture at least 25% by weight, preferably 30% by weight, and which have a diblock proportion of at least 40% by weight, Preferably at least 60% by weight. Good shear strength values ​​can be achieved in particular.

p0029According to the invention, high self-adhesive compositions can be used in accordance with the invention. Two-block (SB)_nStyrene-butadiene multi-arm copolymers having the above-mentioned styrene and diblock portions, for example commercially available under the trade name Kraton® D1118 (styrene content 33 ± 2% by weight, diblock content about 78% by weight) Are available.

p0030It is advantageous if the use concentrations for the block copolymer or the block copolymer mixture are in a concentration in the range between 30% by weight and 70% by weight, in particular in the range between 35% by weight and 55% by weight, Based on the PSA.

p0031Tackifiers which are compatible with the elastomer block of the styrene block copolymers are used in particular as tackifiers. Suitable tackifying resins are inter alia preferably unhydrogenated or partially or completely hydrogenated resins based on rosin or rosin derivatives, hydrogenated polymers of dicyclopentadiene, non-hydrogenated, partially, selectively or completely hydrogenated hydrocarbon resins based on C-5, C-5 / C-9 Or C-9 monomer streams, or particularly preferably polyterpene resins based on α-pinene and / or β-pinene and / or ö-limonene. The aforementioned tackifying resins can be used either alone or in a mixture. In addition, the adhesive composition formulation more preferably has at least one adhesive resin, which is liquid at room temperature.

p0032Further additives can advantageously be used alone or in combination:<ul><li>Primary antioxidants such as sterically hindered phenols,</li><li>Secondary antioxidants such as, for example, phosphites or thioethers,</li><li>Process stabilizers such as, for example, C-radical traps,</li><li>Light stabilizers, such as, for example, UV absorbers or sterically hindered amines,</li><li>processing aids,</li><li>End block enhancer resins.</li></ul>

p0033Furthermore, it is advantageous if the tackifying resins used contain a high proportion of liquid resins, in particular a proportion of at least 25% by weight, preferably at least 35% by weight, based on the total amount of the resins used.

p0034Such a composition has a particularly favorable adhesive force and tack tack. It is particularly advantageous if the upper self-adhesive composition has a complex viscosity of 15,000 Pa · s or more.

p0035Usually, the bulk coat of the upper self-adhesive composition is in a range from 30 to 100 g / m² , In particular in a range from 35 to 70 g / m².

p0036Suitable cleavable carriers are all cleavable sheet-like carrier materials, in particular light-splitting papers, paper bonding systems (for example, duplex papers and sized paper systems), film bonding systems (for example glued film systems), polymeric bonding systems (for example coextruded polymeric bonding systems) and polymeric nonwovens. A carrier is usually used in which the splitting force is 5 to 70 cN / cm, in particular 12 to 60 cN / cm.

p0037It is necessary that the upper self-adhesive composition and the lower self-adhesive composition have a high adhesive force. In particular, the adhesive force of these self-adhesive compositions on the respective surfaces (carrier and web material to be bonded) must be greater than the force required for splitting the splittable carrier. The lower self-adhesive composition is in particular a resin-modified acrylate composition. Such resin-modified or resin-blended compositions comprise an adhesive resin and an acrylate adhesive compound (partially crosslinked). The customary tackifying resins, for example terpenephenol resins and rosins, can be used as the adhesive resin. Acrylate adhesives used are copolymers based on acrylate with a suitable glass transition temperature, in particular copolymers based on components which make the copolymer softer overall (for example, low molecular weight acrylates of type C)₄ to C₁₂ Such as 2-ethylhexyl acrylate or n-butylacrylate), and which also contain constituents which make the copolymer harder overall (for example acrylic acid or functionalized constituents such as glycidyl methacrylate or hydroxyethyl methacrylate). Both compositions are mixed to modify the acrylic adhesive composition with the adhesive resin. Cross-linking is then carried out by conventional crosslinking methods, for example as crosslinking reactions at high temperatures or by using a suitable catalyst, for example of Lewis acids such as zinc chloride.

p0038It is also advantageous if a self-adhesive composition with a complex viscosity of 12,000 Pa · s or more (measuring method tesa test F) is used as the lower self-adhesive composition, in particular if 15,000 Pa · s or more. These embodiments are particularly effective in blocking the cleavable system and thus preventing a failure of the splice connection.

p0039It is likewise advantageous if a resin-modified acrylate adhesive composition is used as the lower self-adhesive composition, it being particularly advantageous if this comprises 70 to 80% by weight of acrylate adhesive composition and 20 to 30% by weight of adhesive resin. In particular, it is advantageous in this case to use as a tackifier resin a terpenephenol resin and / or as an acrylate adhesive composition a copolymer of 48.5% by weight of n-butyl acrylate, 48.5% by weight of 2-ethylhexyl acrylate, 2% by weight of glycidyl methacrylate and 1% by weight By weight of acrylic acid. Such compositions have a high adhesive force on nonpolar surfaces and nonwovens and at the same time ensure the cleavage capacity of the cleavable carrier, inasmuch as they do not penetrate into the cleavable carrier or are pressed out of the adhesive joint because of their lower fluidity.

p0040In principle, the upper self-adhesive composition and the lower self-adhesive composition can also be chosen identically, namely as a silicone-free self-adhesive composition, as described above based on block copolymers.

p0041The constructions of the adhesive tapes according to the invention can be implemented in different designs. In particular, reference is made to the following documents, the disclosure of which is incorporated in its entirety into the disclosure of this document:<ul><li><patcit id="pcit0004" dnum="DE19632689A2"><text>DE 196 32 689 A2</text></patcit> (3) between the carrier (2) and the cover (4) by the local upper adhesive composition (1, 11) ) And / or the lower adhesive compound (also designated 3) there are substituted by the local lower adhesive composition (3, 13)</li><li><patcit id="pcit0005" dnum="DE19902179A1"><text>DE 199 02 179 A1</text></patcit> (1, 11) and / or the adhesive compound N3 there, through the local lower adhesive composition. (DE). WIPO Home services World Intellectual Property Organization (3, 13), and the adhesive compound N2 there also being able to be substituted by one of the local adhesives (1, 11, 3, 13)</li><li><patcit id="pcit0006" dnum="WO9108159A1"><text>WO 91/08159 A1 (Norrman</text></patcit>), In particular the structure according to FIG. 1 and the facts which are explained on page 2, line 35 to page 4, line 14, the adhesive adhesive 3 there being passed through the local upper adhesive composition (1, 11) Lower adhesive composition (3, 13)</li><li><patcit id="pcit0007" dnum="DE19841609A1"><text>DE 198 41 609 A1 (Prinz</text></patcit>), In particular superstructures according to FIG. 1 and the facts illustrated in column 3, line 7 to line 37, the adhesive adhesive 34 there being passed through the local upper adhesive composition (1, 11) and / or the adhesive adhesive 32 there by the local lower adhesive composition (3, 13) are substituted,</li><li><patcit id="pcit0008" dnum="US20040075014A1"><text>US 2004/0075014 A1 (Jacobs et al.</text></patcit>), In particular superstructures according to FIG. 1, and the facts which are explained in the sections [0049] to [0054], wherein the adhesive adhesive 3 located there is passed through the local upper adhesive composition (1, 11) and / or the adhesive adhesive 2 there (3, 13) are substituted,</li><li><patcit id="pcit0009" dnum="US20050126688A1"><text>US 2005/0126688 A1 (Bean et al</text></patcit>2a, 2b, 2c and 2d, and the facts which are explained in sections [0024] to [0037], wherein the adhesive compositions 20 and 20a located there are separated by the local upper adhesive composition (1, 11) and / Or the adhesive compositions 30a and 30b or 30c there are substituted by the local lower adhesive composition (3, 13)</li><li><patcit id="pcit0010" dnum="US6432241B1"><text>US 6,432,241 B1 (Congard et al.</text></patcit>), In particular constructions according to FIGS. 1 and 2, and the facts which are explained in column 3, lines 52 to 64 and column 4, line 34 to column 6, line 53, the adhesive compounds 12 there being separated by the local upper adhesive composition (1, 11) and / or the adhesive mass 15 there are substituted by the local lower adhesive composition (3, 13)</li><li><patcit id="pcit0011" dnum="US20020056784A1"><text>US 2002/0056784 A1 (Davies et al.</text></patcit>), In particular the structure according to FIG. 2, and the facts which are explained in the sections [0038] to [0052], wherein the adhesive materials 16 there are passed through the local upper adhesive composition (1, 11) Adhesive compound (3, 13)</li></ul> Without however wishing to be unnecessarily limited by the reference to the aforementioned embodiments in the invention.

p0042It is particularly advantageous if the adhesive tape comprises a non-splittable carrier whose upper side is coated with the upper self-adhesive composition and whose lower side is completely or at least partially connected to the upper side of the splittable carrier. By using a non-splittable carrier which connects the web of the old roll to the beginning of the web of the new roll before and also after splitting the splittable carrier, a particularly durable connection of the two webs is achieved and the efficiency of the splicing process is further increased. It is particularly advantageous if the lower side of the non-splittable carrier (completely or partially) is connected to the upper side of the splittable carrier by means of a connecting self-adhesive (five-layered construction). This connection can in principle be effected arbitrarily as desired, for example with a self-adhesive composition, a curing hot-melt adhesive composition and the like.

p0043By using a mechanically stable non-splittable carrier, the efficiency of the bonding of the web of the old roll with the beginning of the web of the new roll is greatly increased during the splicing process. As the main carrier, all typical sheet-shaped carrier materials for adhesive tapes can be used, for example paper carriers of plain or double-coated plain base paper as well as film carriers, for example BOPP films, PET films, aluminized PET films and aluminum films. It is desirable that this is a tear resistant main carrier. As a self-adhesive adhesive compound, any typical self-adhesive composition can be used. However, it is advantageous if the connecting self-adhesive composition and the lower self-adhesive composition are chosen identically, for example as a resin-modified acrylate composition, since in this case the risk of blocking the cleavable system is particularly low.

p0044The adhesive tape thus has a splittable carrier over the entire length of the gluing and thus also over the entire length of the adhesive tape. The cleavable carrier can extend over the entire width of the non-splittable carrier. However, it is advantageous if the width of the gapable carrier is smaller than the total width of the adhesive tape, so that a fixation with the underlying web is achieved only in a small part of its width. It is particularly favorable in this case if the gapable carrier does not terminate flush with the non-splittable carrier, but rather is fastened opposite the latter to the lower side thereof. This further reduces the risk of tears occurring during the splicing process.

p0045The invention also encompasses the use of the adhesive tape according to the invention for bonding flat web material wound on rollers with nonpolar surfaces in the course of a flying reel change, in particular of films and / or nonwovens. By using the adhesive tape, the efficiency of the splicing process is significantly increased overall.

p0046Finally, the invention provides a splicing method for the flying reel change of nonpolar flat web material, which is wound on rolls, in particular films and / or nonwovens, the adhesive tape according to the invention being at least partially glued to the end of the uppermost web of a new roll of a nonpolar flat web material Of the adhesive tape is adhered to the underlying web of the new roll and the latter is thus secured, whereupon the new roll thus arranged is placed next to an almost completely coiled roll to be replaced and is accelerated to the same surface speed Whereby the open self-adhesive composition of the adhesive tape is adhered to the old web at substantially equal speeds of the webs while simultaneously cleaving the splittable system and non-adhesively covering the self-adhesive compositions of the splittable system with the two split residues of the splittable carrier.

p0047The invention is described in more detail below with reference to the figures. It shows here<ul><li>FIG. 1 is a schematic side view of an embodiment of the adhesive tape according to the invention (three-layer structure, illustrated transversely with respect to the longitudinal direction of the adhesive tape), and FIG</li><li>FIG. 2 is a schematic side view of a further embodiment of the adhesive tape according to the invention (five-layer structure, shown transversely to the longitudinal direction of the adhesive tape).</li></ul>

p0048DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an adhesive tape according to the invention which is suitable for the flying reel change of flat web material with nonpolar surfaces wound on rollers. The adhesive tape is configured as a three-layered structure of the splittable carrier 2 which is coated on its upper side with the upper self-adhesive composition 1 and on its lower side with the lower self-adhesive coating 3. Such a structure can be used when the splittable carrier 2 has a sufficient mechanical load-bearing capacity along its surface expansion in order to be able to withstand the stresses which occur during the connection of the web of the almost descaled roller with the beginning of the web of the new roll.

p0049The adhesive tape additionally comprises a separating system 6 for the non-adhesive covering of the upper self-adhesive composition 1 so that the adhesive upper side of the adhesive tape is protected during storage. As the separation system, all conventional release papers can be used, for example, siliconized release papers or siliconized release films. The separating system can be designed in one or more parts (not shown in FIG. 1).

p0050FIG. 2 shows a further particularly favorable embodiment of the adhesive tape according to the invention as a five-layered construction. This embodiment of the adhesive tape system comprises a splittable carrier 12 and a non-splittable carrier 14 which are connected to one another. The connection is embodied here as a separate connecting self-adhesive mass 15 which connects the upper side of the splittable carrier 12 to a part of the lower side of the non-splittable carrier 14. The non-splittable carrier 14 is coated on its upper side with the upper self-adhesive composition 11 and on a part of its lower side with the connecting self-adhesive composition 15 which anchors the splittable carrier 12 on the non-splittable carrier 14. The gapable carrier 12 is in this case recessed or offset relative to the non-splittable carrier 14.

p00512 also has a separating system 16 for non-adhesive covering of the upper self-adhesive composition 11, for which all conventional separating papers can be used, for example siliconized separating papers or siliconized separating films. The second-part separation system 16a / 16b illustrated here, which is divided in the longitudinal direction into a rear cover part 16a and a front cover part 16b, for example by means of a perforation or a slot, is particularly advantageous. This has the advantage that the adhesive tape can first be glued to the beginning of the web of the new roll, for which purpose only the adhesive region of the adhesive tape is exposed under the rear cover part 16a, and the adhesive region for bonding with the web of the old roll through the front cover part 16b Remains covered and thus protected.

p0052To illustrate the second embodiment of the adhesive tape according to the invention, a concrete embodiment is given by way of example below:

Example 1:

p0053An adhesive tape according to the invention with a width of 50 mm was produced from a machine-smooth base paper having a basis weight of 54 g / cm 2² And a thickness of 66 μm as a non-splittable carrier 14. The upper side of the non-splittable carrier 14 is coated with an upper self-adhesive composition 11.

p0054A styrene block copolymer based styrene-butadiene-styrene block copolymer (type "Kraton D1118" from Kraton), 24% by weight of an alpha-type resin (type " (Synthetic resin C5-polyterpene / hydrocarbon resin, softening point 10.degree. C.), 0% by weight of a liquid hydrocarbon resin (type "Wingtack 10" from the company DRT, softening point 115 ° C.) 5% by weight of a primary antioxidant (type "Irganox 1010" from Ciba) and 0.5% by weight of a secondary antioxidant (type "Weston 339" from Interorgana).

p0055The adhesive tape also comprises the splittable carrier 12 as well as a lower self-adhesive composition 13 and a connecting self-adhesive composition 15. A paper with a basis weight of 51 g / cm 3 was used as the splittable carrier 12² And a thickness of 90 μm. The width of the splittable carrier 12 was 12 mm.

p0056Furthermore, the adhesive tape has a separating system 16 for non-adhesive covering of the upper self-adhesive composition 11 so that the adhesive upper side is protected when the adhesive tape according to the invention is stored. The present separation system 16 is made of siliconized release paper and comprises a rear cover member 16a covering the portion of the adhesive tape which is bonded to the uppermost layer of the web of the new roll and a front cover member 16b covering the portion of the adhesive tape, With the track of the old roll. Both cover parts are separated from each other by a slot extending along the longitudinal direction of the adhesive tape.

p0057Self-adhesive compositions having the following composition were used as the lower self-adhesive composition 13 and connecting self-adhesive composition 15: 75% by weight of an acrylate-based polymer (as an acrylate adhesive composition) and 25% by weight of a terpenephenol resin (as an adhesive resin).

p0058The product "DT110" from DRT was used as a terpene phenolic resin. As the acrylate-based polymer, a copolymer of 48.5% by weight of n-butylacrylate, 48.5% by weight of 2-ethylhexyl acrylate, 2% by weight of glycidyl methacrylate and 1% by weight of acrylic acid was used. This polymer had a mass-average molecular weight of 950,000 g / mol and a polydispersity of D = 8.7 (as determined from the results of gel permeation chromatography on 100 μl of clarified filter sample (containing 150 μg copolymer dissolved in tetrahydrofuran) using tetrahydrofuran as eluant (0 (Type PSS SDV 10 μm, ID 8 * 50 mm) and a separation column (type PSS SDV 10 μm linear one, ID 8 * 300 mm) from Polymer Standards Service and a differential refractometer (Shodex, RI71 ) For the detection, calibration with polystyrene standard calibration (PSS Ready Cals), polystyrene calibration conversion into a polymethylmethacrylate calibration using the Mark-Houwink coefficients for polystyrene (K = 0.0136, a = 0) , 7140) and polymethyl methacrylate (K = 0.0126, a = 0.6880)). For crosslinking, 0.3% by weight of zinc chloride was added as the Lewis acid, based on the dry mass of the copolymer, and the mixture was dried at 120 ° C. for 15 minutes.

p0059The adhesive properties of the upper self-adhesive composition 11 and of the lower self-adhesive composition 13 or the connecting self-adhesive composition 15 were examined by measuring the adhesive force of the self-adhesive compositions on a polyethylene adhesive base (test method tesa test A), the tacking tack being determined by means of the rolling ball tack (method of measurement) Tesa test D) as well as the complex viscosities of the self-adhesive composition (test method tesa test F).

p0060Furthermore, the adhesive properties of the adhesive tape produced with the self-adhesive compositions 11, 13 and 15 were examined. For this purpose, the shear strength of the adhesive tape on a polyethylene base was determined as the shear time (tesa test B). For this purpose, a strip of the adhesive tape with a width of 13 mm and a length of 20 mm was applied to a polyethylene test plate previously cleaned with ethanol and pressed onto the support four times with a constant contact pressure. The adhesive tape was loaded with 1 kg at room temperature and the shear time (in minutes) was determined as the mean value from three measurements.

p0061Furthermore, the relative gap behavior of a splittable carrier coated on both sides with the respective self-adhesive compositions was tested (tesa test C). The cleavage behavior of a cleavable carrier, which was not coated with self-adhesive compositions, was used as a comparative value. For a measurement, 12 cm long strips of the coated and non-coated carrier were first treated for 24 hours at 40 ° C. under load (2 kg / cm 2)²). For measurement, the carriers were pre-split to a length of 2 cm and the force required for the splitting of the carriers at a gap speed of 300 mm / min was measured. The test was deemed to have passed when the difference in the force required for the splitting was less than 20% in the coated and non-coated carrier.

p0062The results of the tests are given for the upper self-adhesive composition 11 on the one hand and the lower self-adhesive composition 13 / connecting self-adhesive composition 15 on the other hand in Table 1 with reference to the respective test method (tesa test).<tables id="tabl0001" num="0001"><table frame="all"><title>Table 1:</title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><colspec colnum="3" colname="col3" colwidth="30mm" /><colspec colnum="4" colname="col4" colwidth="32mm" /><colspec colnum="5" colname="col5" colwidth="30mm" /><colspec colnum="6" colname="col6" colwidth="23mm" /><thead><row><entry valign="top">Self-adhesive (reference number)</entry><entry valign="top">Adhesive strength [N / cm] (Test A)</entry><entry valign="top">Shear time [min] (test B)</entry><entry valign="top">Relative clearance (test C)</entry><entry valign="top">Roll length [mm] (test D)</entry><entry valign="top">Complex viscosity [the] (test F)</entry></row></thead><tbody><row><entry>Upper (11)</entry><entry>8.2</entry><entry>> 10,000</entry><entry>-</entry><entry>4</entry><entry>25,000</entry></row><row><entry>Lower (13)</entry></row><row><entry>Connecting (15)</entry><entry>2.0</entry><entry>> 10,000</entry><entry>passed</entry><entry>40</entry><entry>16,000</entry></row></tbody></tgroup></table></tables>

p0063A number of further adhesive tapes according to the invention were prepared and measured analogously to Example 1 in which the upper composition was based on the following compositions (total composition of the adhesive composition: 99% basic adhesive mass, 0.5% by weight of primary antioxidant (type "Irganox 1010" Ciba) and 0.5% by weight of secondary antioxidant (type "Weston 339" from Interorgana) according to Example 1). See Table 2.<tables id="tabl0002" num="0002"><table frame="all"><title>Table 2:</title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="12mm" /><colspec colnum="2" colname="col2" colwidth="50mm" /><colspec colnum="3" colname="col3" colwidth="17mm" /><colspec colnum="4" colname="col4" colwidth="13mm" /><colspec colnum="5" colname="col5" colwidth="27mm" /><colspec colnum="6" colname="col6" colwidth="49mm" /><thead><row><entry morerows="1" align="center" valign="top">Ex.</entry><entry morerows="1" align="center" valign="middle">Base composition upper self-adhesive composition (11)</entry><entry namest="col3" nameend="col4" align="center" valign="middle">Adhesive strength [N / cm]</entry><entry morerows="1" align="center" valign="middle">Shear time [min] (test B)</entry><entry morerows="1" align="center" valign="middle">Roll distance [mm] (mean value from three measurements) (test D)</entry></row><row><entry align="center" valign="middle">Steel (Test A2)</entry><entry align="center" valign="middle">PE (Test A)</entry></row></thead><tbody><row><entry morerows="2" rowsep="1" align="center" valign="middle">2</entry><entry align="center" valign="middle">45% Kraton D1118,</entry><entry morerows="2" rowsep="1" align="center" valign="middle">11.6</entry><entry morerows="2" rowsep="1" align="center" valign="middle">10.8</entry><entry morerows="2" rowsep="1" align="center" valign="middle">8023</entry><entry morerows="2" rowsep="1" align="center" valign="middle">3</entry></row><row><entry align="center" valign="middle">25% Dercolyte A115,</entry></row><row><entry align="center" valign="middle">30% Wingtäck 10</entry></row><row><entry morerows="2" rowsep="1" align="center" valign="middle">3</entry><entry align="center" valign="middle">45% Kraton D1118,</entry><entry morerows="2" rowsep="1" align="center" valign="middle">14.0</entry><entry morerows="2" rowsep="1" align="center" valign="middle">12.4</entry><entry morerows="2" rowsep="1" align="center" valign="middle">2750</entry><entry morerows="2" rowsep="1" align="center" valign="middle">27</entry></row><row><entry align="center" valign="middle">30% Dercolyte A115,</entry></row><row><entry align="center" valign="middle">25% Wingtack 10</entry></row><row><entry morerows="2" rowsep="1" align="center" valign="middle">4</entry><entry align="center" valign="middle">50% Kraton D1118,</entry><entry morerows="2" rowsep="1" align="center" valign="middle">14.0</entry><entry morerows="2" rowsep="1" align="center" valign="middle">11.0</entry><entry morerows="2" rowsep="1" align="center" valign="middle">14963</entry><entry morerows="2" rowsep="1" align="center" valign="middle">8th</entry></row><row><entry align="center" valign="middle">30% Dercolyte A115,</entry></row><row><entry align="center" valign="middle">20% Wingtack 10</entry></row><row><entry morerows="2" rowsep="1" align="center" valign="middle">5</entry><entry align="center" valign="middle">50% Kraton D1118,</entry><entry morerows="2" rowsep="1" align="center" valign="middle">8.8</entry><entry morerows="2" rowsep="1" align="center" valign="middle">8.8</entry><entry morerows="2" rowsep="1" align="center" valign="middle">6337</entry><entry morerows="2" rowsep="1" align="center" valign="middle">2</entry></row><row><entry align="center" valign="middle">25% Dercolyte A115,</entry></row><row><entry align="center" valign="middle">25% Wingtack 10</entry></row><row><entry morerows="2" rowsep="1" align="center" valign="middle">6</entry><entry align="center" valign="middle">45% Europrene SOL T-192,</entry><entry morerows="2" rowsep="1" align="center" valign="middle">11.8</entry><entry morerows="2" rowsep="1" align="center" valign="middle">8,0</entry><entry morerows="2" rowsep="1" align="center" valign="middle">4809</entry><entry morerows="2" rowsep="1" align="center" valign="middle">12</entry></row><row><entry align="center" valign="middle">25% Dercolyte A115,</entry></row><row><entry align="center" valign="middle">30% Wingtack 10</entry></row><row><entry morerows="2" rowsep="1" align="center" valign="middle">7</entry><entry align="center" valign="middle">45% Europrene SOL T-192,</entry><entry morerows="2" rowsep="1" align="center" valign="middle">11.8</entry><entry morerows="2" rowsep="1" align="center" valign="middle">8,0</entry><entry morerows="2" rowsep="1" align="center" valign="middle">4809</entry><entry morerows="2" rowsep="1" align="center" valign="middle">12</entry></row><row><entry align="center" valign="middle">25% Dercolyte A115,</entry></row><row><entry align="center" valign="middle">30% Wingtack 10</entry></row></tbody></tgroup><tgroup cols="6" rowsep="0"><colspec colnum="1" colname="col1" colwidth="12mm" /><colspec colnum="2" colname="col2" colwidth="50mm" /><colspec colnum="3" colname="col3" colwidth="17mm" /><colspec colnum="4" colname="col4" colwidth="13mm" /><colspec colnum="5" colname="col5" colwidth="27mm" /><colspec colnum="6" colname="col6" colwidth="49mm" /><tbody><row><entry namest="col1" nameend="col6" align="justify">All trade names: ®</entry></row></tbody></tgroup></table></tables>

p0064The use of adhesive tapes produced in this manner during the flying roll replacement of polyethylene films with a thickness of 35 μm to 60 μm was successfully carried out in the practice test.