Adhesive tape and its use

The subject of the invention is an adhesive tape and its use, especially for the dynamic exchange of rolls with wound non-polarized material in the form of a tape according to the overarching concept of the main claim.

[2] When using tape material (paper, films, nonwovens, etc.), dynamic roller replacement is a method used to replace an old, almost worn roll by a new roller, without the need to stop high-speed machines. In this type of dynamic roller replacement, adhesive tapes are often used to connect the end of an old tape to the beginning of a new tape.

[3] In the film and nonwovens processing industry, a dynamic roll change is carried out, in the case of materials with non-polar surfaces, in two different ways.

[4] According to the first method, manually sticking a new roll at the beginning of the tape, double-sided adhesive tapes in a preferred arrangement (usually straight or in the shape of the letter v or v) and the tape protruding from the adhesive tape is cut off. The beginning of the tape on a new roll is glued using a fastening label (or "retainer") on the underlying roll of the new roll to prevent unwinding of the tape when the new roll accelerates to the peripheral speed of the old roll. The disadvantage of this method is that the preparation of the rolls is very labor intensive and gluing can only be carried out by highly qualified employees. In addition, this method does not always give the desired results because the adhesive joints made in this way are relatively thick due to the overlapping of tape material, fastening labels and adhesive tape. For this reason, thin elastic bands may come to the point that at the beginning of the new bands, due to the reverse air stream being present, the bands may be erected, which generally leads to improper sticking of the bands.

[5] In the second known method, one-sided adhesive tape is glued onto the overlap and straight under the free end of the upper tape of the new roll, so that the adhesive side is directed outwards and only partially covered by the new tape. The rest of the adhesive side facing out is glued to the tape of the old roll. In this method, to prevent the tape from unwinding when the new roll accelerates to the peripheral speed of the old roll, liquid is introduced between the upper roll of the new roll and the roll below it, so that the upper roll is fixed on the underlying roll by capillary forces. The disadvantage of this method is that also with this method it is necessary to employ highly qualified personnel, and yet technically advantageous results are not always obtained, because the effectiveness of liquid strip determination depends on many parameters, e.g. surface energy, flexibility and surface mass tape, from the amount of liquid used, its polarization, viscosity, density and layer thickness, surface and shear resistance of the liquid layer. An important disadvantage of this method is also that the belt speed when changing the rollers cannot be too high and the line and the belt may be contaminated by the liquid used.

[6] The above method is also used in the paper industry. Another version of the first method is the splitting method in which the retainer is placed in an adhesive tape connecting the paper tapes. When the tapes are joined, the substrate delaminates as a retaining element, as a result of which a part of the delaminated substrate remains on the adhesive tape tapes (i.e. on the top scroll), while the other part remains on the scroll below. "Fissile" are defined as substrates which delaminate parallel to the direction of the surface elongation, and especially those substrates which, in relation to the requirements of the gluing method, actually delaminate.

[7] Several products are known in the paper industry to implement this method. For example, DE 196 32 689 A2 discloses an adhesive tape which, in addition to the main substrate, also has a fissile paper substrate. At dynamic loads, when joining both rollers' tapes, the paper substrate breaks down and its remains cover the adhesive mass used for gluing in the area that remains exposed in the case of other adhesive tapes. DE 199 02 179 A1 also discloses this type of adhesive tape in which the fissile paper substrate is displaced relative to the main substrate to prevent cracks in the event of loading.

[8] EP A2 1 342 684 describes an adhesive tape for dynamic replacement of tape rolls, with an adhesive top side and a non-sticky bottom side, and with two longitudinal edges, with a main substrate which is coated on one side with adhesive. part of the bottom without adhesive has at least one self-adhesive system and a splitting method for dynamic replacement of rollers containing a wound tape.

[9] In order to improve the dynamic exchange of rolls in the film and nonwovens processing industry, it would be desirable to use adhesive tapes with a structure similar to those already known from the paper industry. This is particularly desirable for films and nonwovens with non-polarized surfaces. Such non-polar surfaces are found in materials with low surface energy, such as polyethylene, polypropylene, polyethylene terephthalate (PET) or polymer coated papers. Surface energy is small when it is 50 mN / m or less. Self-adhesive masses that are particularly sticky and very adhesive are needed for this type of non-polarized surface. The high adhesive strength and high tack (so-called "tack") required for this can usually be achieved in such a way that the fluidity of the adhesive mass increases.

[10] Traditionally used adhesive masses with high adhesive strength and high tactile tack are not suitable, or only to a small extent, for the dynamic replacement of rolls containing non-polarized films and nonwovens, using the splitting method. Increasing the adhesive strength and tactile adhesive mass is associated with an increase in their fluidity. This type of adhesive, due to its high fluidity, is squeezed out of the fissile system, equipped with the adhesive, and can even penetrate into the fissile substrate, which can lead to blocking of the fissile system and to the release of the adhesive connection. In addition, it is disadvantageous that liquid adhesive compounds escape from the adhesive joint during splitting, and thus, after splitting, adhesive residue may remain in the system without coating.

[11] The object of the invention is therefore to develop an adhesive tape, equipped with at least an upper adhesive mass, a fissile substrate and a lower adhesive mass on the lower side of the fissile substrate, suitable for dynamic roller replacement with a non-polarized tape wound at high tape speeds.

[12] This task was successfully solved by means of an adhesive tape suitable for dynamic roller exchange with a wound tape with non-polarized surfaces, especially with polyolefinic substrates in which a self-adhesive adhesive without silicone is used as the upper adhesive mass, with adhesive strength on a polyethylene substrate 1.5 N / cm or more (measuring method: tesa test) and with tactile stickiness corresponding to a turning length of 50mm or less (measuring method: D tesa test), in which the bottom self-adhesive mass is self-adhesive mass with a bonding strength on a polyethylene substrate of 1.5 N / cm or more (measuring method: tesa test) and with a complex viscosity of 10,000 Pa ^ s or more at 1 rad / s and 40 ° C (measuring method: tesa test).

For dynamic roller exchange, it is particularly advantageous if the tactile tack of the upper adhesive mass corresponds to a turning length of 50 mm or less (measuring method: D tes test).

[13] The upper self-adhesive mass is a self-adhesive mass created on the basis of a mixture composed of several styrene block copolymers containing at least one diblock copolymer, in which one of the blocks is based on styrene, with the share of styrene being at least 25% by weight and / or the share of diblock is at least 40% by weight, based on the total amount of block copolymer.

[14] The lower self-adhesive mass is a modified acrylate mass or a self-adhesive mass identical to the upper self-adhesive mass.

[15] The upper adhesive mass in the splitting method serves to connect the upper surface of the adhesive tape according to the invention to the beginning of the tape of the new roll and the tape of the old roll almost completely unwound, as a result of which the tapes of both rollers are joined together by means of adhesive tape. The lower self-adhesive mass is used to connect the lower surface of the adhesive tape according to the invention to the second roll from above, so that the upper and second rolls of the new roll are joined together first by means of an adhesive tape. In the further course of the splitting method, with the splitting of the fissile substrate, the connection of the two upper turns of the roll re-disconnects and in such a way that the adhesive areas of the upper adhesive mass facing away from the upper surface of the respective roll and the lower adhesive mass of the already split substrate remain covered in a way that lacks adhesive properties.

[16] Important is the specific shape of the upper self-adhesive mass and the lower self-adhesive mass in terms of their adhesive strength, tactile stickiness and viscosity. According to the invention, the choice of the complex viscosity of the lower adhesive mass causes the cold flow of the lower adhesive mass to be prevented. As a result, the adhesive at the bottom of the fissile substrate must not flow out of the adhesive connection and stick to the top of the fissile substrate, thereby preventing blockage of the substrate and the system still retaining the splitting ability.

[17] For the upper self-adhesive mass, it is particularly advantageous to select such a mass that meets the requirements of the film gluing process. It is preferred that it has sufficient tactile tack (tack) so that during the splitting process on non-polarized materials, especially on polyolefinic substrates, it can be easily gripped, during the process it should not undergo shearing on such substrates, and thus has good shear strength. and showed sufficiently high adhesive strength also on the polyolefin material.

[18] The determination of the adhesive strength was carried out in the following way (A tesa test): As a defined adhesive substrate (plate with specific adhesive strength) a polyethylene plate was used, made as an injection control plate, from HDPE granules (high pressure polyethylene)

Hostalen GC7260 from Basell. This plate was washed with ethanol before measurement. The sample to be tested was a standard polyester base with a thickness of 23 μ ^ ι and was coated on one side with a suitable adhesive (adhesive layer: 50 g / m²). A strip of coated standard polyester substrate, 20 mm wide, was pressed against the adhesive substrate (2 kg). Immediately thereafter, the adhesive tape was pulled away from the substrate at an angle of 180 °, at a speed of 300 mm / min, during which the necessary force at room temperature was measured. The measured value (in N / cm) was determined as the mean value of three measurements. For calibration of the "tesa test" measuring method, a commercially available test adhesive tape was used to test non-stick coatings (type "tesa 7475" from tesa AG; the adhesive strength on steel is 31.25 N / 25 mm); the adhesive strength determined on the polyethylene control plate was 4.5 N / cm.

Comparative tests were partly carried out on steel instead of polyethylene, with identical other test parameters (test A2).

[19] Determination of tactile stickiness was carried out as follows (D tes test): as a measure of tactile stickiness with a very short contact time, the so-called Rolling-ball-Tack. The tests were carried out on a sample being a standard polyester base with a thickness of 23 μm, coated on one side with each tested adhesive mass (coating of adhesive mass: 50 g / m²). On the test surface, a strip of adhesive tape 10 cm long was fixed horizontally with the adhesive side up. The steel ball, intended for testing (diameter: 11 mm; weight: 5.6 g), was washed with acetone and conditioned for 2 hours in a room microclimate (temperature: 23 ° C +/- 1 ° C; relative humidity: 50% +/- 1%). To carry out the measurement, the steel ball was accelerated in a gravitational field by rolling it off a 65 mm high incline (angle of inclination 21 °). The steel ball was directed from the inclined plane directly on the adhesive surface of the sample. The distance traveled by the ball on the adhesive mass was measured until the ball stopped. The turning distance determined in this way is an inverse measure of the tactile tack of the adhesive (i.e. the shorter the rolling distance, the greater the tactile tack and vice versa). Based on the measurement results, the average value of five measurements was determined (as the segment length in mm).

[20] The determination of the complex viscosity was carried out as follows (F tes test): the pressure-sensitive adhesive obtained in the form of a cylindrical sample 25 mm in diameter and 0.8 mm in height, was tested in a deformation-controlled rheometer (type RDA III, Rheometrics Scientific; plate - plate - measuring head system: 2000 g Bendix) (with 3 N axial preload). The dynamic measurement was carried out at 40 ° C, room microclimate (conditions according to the standard) and at 3% deformation of the sample, in the frequency range from 0.1 to 500 rad / s, as the complex viscosity η *. The numerical value (in Pa ^ s) of "complex viscosity" is the value of the complex viscosity measured in the low frequency region (1 rad / s) and at 40 ° C.

[21] For the adhesive tape according to the invention, it is advantageous if a mass is used as the upper self-adhesive mass and / or lower self-adhesive mass which on the polyethylene pressure-sensitive substrate has an adhesive strength of 3.0 N / cm or more (measuring method: Test A test ), it being particularly preferred if the adhesive strength on the pressure-sensitive polyethylene substrate is 5.0 N / cm or more. Thanks to this, particularly effective adhesion of the adhesive tape on the non-polarized tape to be joined is achieved, which further improves the durability of the connection and thus the effectiveness of the gluing method.

[22] Furthermore, it is advantageous if a mass that exhibits tactile adhesion corresponding to a rolling distance of 40 mm or less is used as the upper adhesive mass (measuring method: D tes test), where it is particularly advantageous when the rolling distance is used as a measure of tactile stickiness, it is 20 mm or less. As a result, a particularly high efficiency coefficient is achieved when connecting the belts by jointly guiding both rotating rollers.

[23] Masses based on styrene block copolymers are used as the upper self-adhesive masses. In this case, according to the invention, copolymers formed from vinyl polymer aromatic polymer blocks, particularly preferably formed from styrene blocks (A blocks) and polymer blocks, by polymerizing 1,3 dienes (B blocks), such as butadiene or isoprene or copolymer. The copolymer may be e.g. a copolymer of the above-mentioned butadiene and isoprene compounds. Mixtures of different styrene block copolymers can be used. It is also possible to use partially or fully hydrogenated products.

[24] The use of block copolymers of one of the components consisting of block copolymers with a linear ABA structure is preferred. In addition, the use of linear multi-block copolymers is preferred. The use of block copolymers in radial form and star-shaped multi-block copolymers is particularly preferred.

[25] As another component, AB double-block copolymers are preferably used, especially those which are based on the above-mentioned block monomers A and B.

[26] According to the invention, the upper self-adhesive mass (1, 11) is a self-adhesive mass created on the basis of a blend composed of several styrene block copolymers containing at least one diblock copolymer in which one of the blocks is based on styrene, with the share of styrene being at least The 25% by weight and / or proportion of diblock is at least 40% by weight, based on the total amount of block copolymer.

[27] According to the invention, it is possible to use as an upper self-adhesive mass, for example, two-block copolymers containing SIS - styrene-isoprene-styrene with the above-mentioned proportions of styrene or diblocks, such as commercially available under the trade name Europrene® SOL T-192 from EniChem (content of styrene 25% by weight, content of diblocks 23% by weight).

[28] Adhesives which contain at least a block copolymer mixture in which the styrene content is at least 25% by weight and more preferably 30% by weight and in which the content of diblocks is at least 40% by weight have proved to be particularly advantageous for use on top pressure-sensitive adhesive. and more preferably a minimum of 60% by weight. In this way, particularly good shear strength values ​​can be achieved.

[29] According to the invention, it is particularly advantageous to use as a self-adhesive top mass diblocks containing multi-arm (SB) copolymers of nstyrene-butadiene with the abovementioned styrene and diblock contents, e.g. available under the trade name Kraton® D1118 (styrene content 33 ± 2% by weight, content diblocks approx. 78% by weight as specified).

[30] It is preferred that the content of block copolymers or blend of block copolymers used is in the range of 30% to 70% by weight, in particular in the range of 35% to 55% by weight, based on the pressure-sensitive adhesive.

[31] Adhesives are especially adhesive resins that are well suited to the elastomer block of styrene block copolymers. Suitable adhesive resins are, among others especially non-hydrogenated, partially hydrogenated or fully hydrogenated rosin or rosin derivative resins, hydrogenated dicyclopentadiene polymerizates, non-hydrogenated, partially, selectively or fully hydrogenated hydrocarbon resins based on C-5, C-5 / C-9 or C-9 a monomer streams particularly preferably polyterpene resins based on α-pinene and / or β-pinene and / or o-limonene. The abovementioned glue resins can be used both in a mixture and alone. In addition, the content in the adhesive mass of at least one adhesive resin which is liquid at room temperature is particularly preferred.

[32] As other additives, the following additives may be advantageously used, alone or in combination:

• primary antioxidants, e.g. phenols with a spatial obstacle, • secondary antioxidants, e.g. phosphites or thioethers, • process stabilizers, such as C radical scavengers, • sunscreen preparations, such as UV absorbers or obstacles spatial, • auxiliary substances, • end block reinforcing resins.

[33] It is furthermore preferred that the adhesive resins used contain a lot of liquid resins, particularly in an amount of at least 25% by weight, and more preferably at least 35% by weight based on the total weight of the resin used.

[34] This type of composition exhibits particularly good adhesive strength and tactile stickiness. It is particularly advantageous if the upper adhesive mass has a complex viscosity of 15,000 Pa.s or more.

[35] Usually, top cover mass is chosen in the range from 30 to 100 g / m2², especially in the range from 35 to 70 g / m2².

[36] As fissile substrates, all fissile, flat backing materials are particularly suitable, especially easily delaminated papers, multilayer papers (for example duplex papers and glued papers), multilayer films (e.g. glued films), polymer multilayer systems (e.g. coextruded jointly , multi-layer polymer systems) and polymeric nonwovens. Usually, a substrate with a split strength of 5 to 70 cN / cm, in particular 12 to 60 cN / cm is used.

[37] It is necessary for the upper and lower adhesive mass to exhibit high adhesive strength. The adhesive strength of these self-adhesive masses on appropriate surfaces (substrate and tape intended for gluing) is greater than the force necessary for splitting the delaminated substrate. Acrylic mass modified with resins is especially used as the bottom adhesive mass. Such modified or mixed masses include glue resins and acrylate (partially crosslinked) adhesive. As adhesive resins, conventional adhesive resins are used, for example phenol-terpene resins and rosin resins. Acrylate adhesive copolymers with an appropriate glass transition temperature are used, in particular copolymers based on copolymer softening components (e.g. low molecular type C4 to C12 acrylates, such as 2-ethylhexylacrylate or n-butyl acrylate) and also containing ingredients that increase polymer hardness (for example acrylic acid or functionalized components such as glycidyl methacrylate or ethylene hydroxymethacrylate). Mixing the two masses is used to modify the acrylate adhesive mass with adhesive resin. Crosslinking is then carried out by the usual crosslinking method, e.g. as a crosslinking reaction at high temperatures or by using a suitable catalyst, e.g. Lewis acids e.g. zinc chloride.

[38] Furthermore, it is preferred that a compound having a complex viscosity of 12,000 Pa · s or more (measuring method: Fes test), and especially 15,000 Pa · s or more, is used as the lower adhesive mass. Such a configuration helps particularly effectively to prevent blockage of the fissile system and thus to unsealing of the adhesive connection.

[39] It is also advantageous if a resin modified acrylate adhesive is used as the bottom adhesive mass, with 70 to 80% mass being the acrylate mass adhesive and 20 to 30% mass being the adhesive resin. It is particularly preferred to use as a glue resin - phenol-terpene resin and / or as an acrylate adhesive - a copolymer consisting of n-butacrylate (48.5% by weight), 2-ethylhexyl acrylate (48.5% by weight), glycidyl methacrylate ( 2% by weight) and acrylic acid (1% by weight). These types of compositions exhibit high adhesive strength on non-polar surfaces and nonwovens, and at the same time ensure the ability of delamination of the fissile substrate, provided that due to their low fluidity they cannot penetrate either into the fissile substrate or flow out of the adhesive connection.

[40] In general, the upper and lower adhesive masses can also be identical as silicone-free adhesive masses as described above based on block copolymers.

[41] Structures of adhesive tapes according to the invention can be made in various versions. In particular, reference is made to the following documents, the disclosure of which has been fully taken into account in the scope of disclosure in this document:

- DE 196 32 689 A2 (Beiersdorf), in particular the arrangement according to Fig. 1 and the actual situation explained in column 3, lines 31 to 44, the adhesive mass placed there at the top (3; between substrate 2 and cover 4) is replaced by the local adhesive (1, 11) and / or the adhesive (also marked with 3) is replaced by the local adhesive (3, 13),

- DE 199 02 179 A1 (Beiersdorf), in particular the system according to Fig. 1 and the actual situation explained in column 3, lines 31 to 34, where the adhesive N1 is replaced by the local upper adhesive (1, 11) and / or the N3 adhesive is replaced by the lower adhesive (3, 13), while the N2 adhesive may also be replaced by one of the local adhesive (1, 11, 3, 13),

- WO 91/08159 A1 (Norrman), in particular the system according to Fig. 1 and the actual situation explained on page 2, line 35 to page 4, line 14, where the adhesive 3 is replaced by the local upper adhesive (1, 11 ) and / or local adhesive 4 is replaced by local adhesive (3, 13),

- DE 198 41 609A1 (Prinz), in particular the systems according to Fig. 1 and the actual states explained in column 3, lines 7 to 37, the adhesive mass 34 being replaced by the local upper adhesive mass (1, 11) and / or the adhesive 32 is replaced by the local lower adhesive (3, 13),

- US 2004 / 0075014A1 (Jacobs et al.) And especially the structures according to Fig. 1 and the actual states discussed in chapters [0049] to [0054], where the adhesive 3 is replaced by the local upper adhesive (1, 11) and / or the adhesive 2 there is replaced by the local lower adhesive (3, 13),

US 2005 / 0126688A1 (Bean et al.), And in particular the systems according to Figs. 2a, 2b, 2c and 2d and the facts discussed in chapters [0024] to [0037], where the adhesive masses 20 to 20a are replaced by the local upper the adhesive (1, 11) and / or the adhesive 30a and 30b or 30c there is replaced by the local lower adhesive (3, 13),

- US 6,432,241 B1 (Congard et al.), In particular the systems according to Figs. 1 and 2 and the actual situation explained in column 3, lines 52 to 64 and in column 4, lines 34 to column 6, line 53, with the adhesive masses there 12 are replaced by the local adhesive (1, 11) and / or the adhesive 15 is replaced by the local adhesive (3, 13),

- US 2002 / 0056784A1 (Davies et al.), In particular the system according to Fig. 2 and the actual state explained in chapters [0038] to [0052], the adhesive masses 16 being replaced by the local upper adhesive mass (1, 11) and / or the adhesive 24 therein is replaced by the local lower adhesive (3, 13), whereby reference to the above-mentioned forms of implementation does not unnecessarily limit the invention.

[42] It is particularly advantageous if the adhesive tape comprises an non-fissile substrate, the upper side of which is coated with an upper adhesive mass, and the lower side is connected completely or at least partly to the upper surface of the fissile substrate. By using a non-fissile substrate that connects the old roll tape with the beginning of the new roll tape before and also after delamination of the fissile substrate, a particularly load-bearing connection of both tapes is achieved and the effectiveness of the gluing method is still increased. It is particularly advantageous here when the lower side of the non-fissile substrate is connected (completely or partially) to the upper side of the fissile substrate via a bonding adhesive (five-layer system). This connection can generally be shaped arbitrarily, e.g. using self-adhesive mass, setting melting adhesive mass, etc.

[43] By using a mechanically stable, non-fissile substrate, the method of gluing increases the gluing efficiency of an old roll tape with the beginning of a new roll tape. As the main substrate all typical flat substrates for adhesive tapes can be used, e.g. a paper substrate consisting of smooth undercoat paper, coated on one or both sides and foil substrates, e.g. BOPP (biaxially oriented propylene films), polyethylene films, aluminized polyethylene films and aluminum foils. It is desirable for this to be a tear-resistant main substrate. Any typical self-adhesive compound can be used as the adhesive bonding compound. It is, however, preferred that the combination of self-adhesive mass and bottom self-adhesive mass are identical, e.g. as a resin modified acrylate mass, because in this case the risk of blocking the fissile system is particularly low.

[44] Accordingly, the adhesive tape has a fissile substrate along the entire length of the gluing, and thus also the entire length of the adhesive tape. The fissile medium may cover the entire width of the non-fissile medium. It is, however, advantageous if the width of the fissile substrate is less than the total width of the adhesive tape, so that only a small part of its width is established with the underlying tape. It is particularly advantageous here when the fissile substrate does not end flush with the non-fissile substrate but is retracted relative to it and attached to its underside. As a result, the risk of tearing with the splitting method is further reduced.

[45] The invention further includes the use of an adhesive tape according to the invention for gluing a tape wound on rolls with a non-polarized surface during dynamic replacement of rolls, especially films and / or nonwovens. The use of adhesive tape significantly increases the efficiency of the adhesive method.

[46] Finally, the invention offers a method of gluing for the dynamic exchange of rolls with a wound, non-polarized tape, in particular of foil and / or nonwovens, whereby at the end of the upper tape of a new roller containing non-polarized tape the adhesive tape according to the invention is glued (at least in part), and the bottom surface of the adhesive tape is glued to the new roll of underlying tape and secured by it, after which the new roller thus fitted is placed next to the almost completely unwound, the roller to be replaced and accelerates to the same peripheral speed, then the new roller is pressed against the upper tape of the old roller, whereby the uncovered adhesive mass of the adhesive tape is glued to the old tape at almost equal speed of the tapes, while at the same time the system is delaminated the fissile and adhesive masses of the fissile system are covered by both stratified remains of the fissile substrate, in a manner devoid of adhesive properties.

[47] The invention is described in more detail on the basis of examples, with reference to a drawing whose individual figures show:

Fig. 1 - schematic side view of an adhesive tape system according to the invention (three-layer system, shown transversely to the longitudinal direction of the adhesive tape) and

Fig. 2 - schematic side view of another embodiment of an adhesive tape according to the invention (five-layer system, shown transversely to the longitudinal direction of the adhesive tape).

[48] ​​Fig. 1 shows an adhesive tape according to the invention, suitable for dynamic replacement of rolls containing a wound tape with non-polarized surfaces. The adhesive tape has a three-layer structure, with a fissile substrate 2, the upper surface of which is coated with an upper adhesive mass 1, and the lower surface with a lower adhesive mass 3. This type of system is used when the fissile substrate 2 exhibits sufficient mechanical load capacity along the surface deformation direction to withstand the loads that occur when joining a tape from an almost unrolled roll with the beginning of the tape of a new roll.

[49] The adhesive tape additionally includes a distribution system 6 to cover the upper adhesive mass 1 in a manner devoid of adhesive properties so that the adhesive upper surface of the adhesive tape is protected during storage. The distribution system can be all traditionally used separation papers, e.g. siliconized papers or siliconized films. In this case, the distribution system can be one-part or multi-part (not shown in figure 1).

[50] Fig. 2 shows another, particularly advantageous configuration of the adhesive tape according to the invention with a five-layer structure. Such adhesive tape includes fissile substrate 12 and non-fissile substrate 14 connected to each other. The connection is made here by means of a separate, adhesive self-adhesive compound 15, which connects the upper surface of the fissile substrate 12 with the lower part of the non-fissile substrate 14. Thus, the upper surface of the non-fissile substrate 14 is coated with an upper adhesive mass 11 and on a part of its lower surface is coated by a bonding adhesive mass 15 which fixes the fissile substrate 12 to the non-fissile substrate 14. The fissile substrate 12 is backed away from the non-fissile substrate 14 or positioned offset.

[51] The system shown in Fig. 2 additionally has a distribution system 16 to cover the upper self-adhesive mass 11 in a way that deprives itself of adhesive properties. All traditionally used release papers, e.g. siliconized papers or siliconized films, are used for this purpose. Particularly preferred is the two-part distribution system 16a / 16b shown here, which in the longitudinal direction is divided into a rear casing 16a and a front casing 16b, optionally by means of perforation or a groove. This has the advantage that the adhesive tape can be initially glued to the beginning of the tape of the new roll, whereby the adhesive area of ​​the adhesive tape is exposed only underneath the rear cover part 16a, and the adhesive area used to stick to the tape of the old roll still remains covered by the front part shield 16b and thus remains protected.

[52] To explain the second embodiment of the adhesive tape according to the invention, a specific embodiment is shown below:

Example 1:

[53] Adhesive tape according to the invention, 50 mm wide, was made of machine-coated base paper, with an area weight of 54 g / cm.² and 66 μm thick as non-fissile substrate 14. The upper surface of the non-fissile substrate 14 is coated with an upper adhesive mass 11.

[54] As the upper self-adhesive mass 11 a synthetic rubber based on styrene block copolymers was used, with the following composition: 48% by weight - styrene-butadiene-styrene block copolymer (Kraton type "D1118" from Kraton), 24% by weight alphapinene resin (type " Dercolyte A115 "from DRT, softening point 115 ° C), 27% by weight - liquid hydrocarbon resin (" Wingtack 10 "type from Goodyear - liquid, synthetic, aliphatic C-5 polyterpene / hydrocarbon resin; softening point 10 ° C), 0.5% by weight - primary antioxidant (type "Irganox 1010" from Ciba) and 0.5% by weight - secondary antioxidant (type "Weston 339" by Interorgana).

[55] Adhesive tape further includes a fissile substrate 12 and a lower adhesive mass 13 and a bonding adhesive mass 15. As a fissile substrate 12 paper with a surface weight of 51 g / cm was used.² and 90 μm thick. The width of the fissile medium 12 was 12 mm.

[56] Furthermore, the adhesive tape comprises a two-part distribution system 16 for covering the upper adhesive mass 11, in a way that deprives it of adhesive properties, so that the adhesive upper surface is protected during storage of the adhesive tape according to the invention. The illustrated distribution system 16 is made of siliconised distribution paper and includes a rear casing 16a covering the part of the adhesive tape connected to the top layer of the new roll tape and a front casing 16b covering the part of the adhesive tape which is connected to the old roll tape. Both shield parts are separated by a cut, running parallel to the longitudinal direction of the adhesive tape.

[57] Identical adhesive masses having the following composition were used as the bottom adhesive mass 13 and bonding adhesive mass 15: 75% of the polymer based on acrylate (as acrylate adhesive) and 25% of phenol-terpene resin (as resins).

[58] The "DT110" product from DRT was used as the phenol-terpene resin. As a polyacrylate-based polymer, a copolymer consisting of n-butyl acrylate (48.5% by weight, 2-ethylhexyl acrylate (48.5% by weight), methacrylate was used glycidyl (2% by weight) and acrylic acid (1% by weight). This polymer has a mass average molecular weight of 950,000 m / mol and a polydispersity value of D = 8.7 (determined on the basis of the results of gel chromatography, carried out on 100 μl of a filtered sample containing 150 μg of a soluble copolymer in tetrahydrofuran), using tetrahydrofuran as eluent (0.5 ml / min), pre-column (type PSS SDV 10 μ ^ ι, internal diameter 8 * 50 mm) and distribution column (type PSS SDV 10 μ (τι, linear one, internal diameter 8 * 300 mm) by Polymer Standards Service and differential refractometer (Shodex RI71) for detection; calibration was carried out using a narrowly distributed polystyrene standard (PSS Ready Cals; Polymer Standards Service); the conversion of polystyrene calibration into calibration based on polymethyl methacrylate was carried out using the Mark-Houwink coefficient for polystyrene (K = 0.0136; a = 0.7140) and polymethyl methacrylate (K = 0.0126; a = 0.6880). For crosslinking, zinc chloride (0.3% by weight) was added to the blend as Lewis acid based on the dry weight of the copolymer and drying was carried out for 15 min. at 120 ° C.

[59] First, the adhesive properties of the upper adhesive mass 11 and the lower adhesive mass 13 or the adhesive mass 15 were tested by determining the adhesive strength of the adhesive masses on a pressure-sensitive polyethylene substrate (measuring method: A tesa test), their tactile stickiness based on Rolling-Ball -Tacks (measuring method: D tesa test) and viscosity of the complex adhesive mass (measuring method: F tesa test).

[60] Next, the adhesive properties of adhesive tape manufactured using self-adhesive masses 11, 13 and 15 were tested. To this end, the shear strength of the adhesive tape on a polyethylene substrate was determined as shear resistance (tesa B test). For this purpose, a strip of adhesive tape, 13 mm wide and 20 mm long, was placed on a polyethylene control plate previously cleaned with ethanol and pressed four times into the substrate using constant pressure. The adhesive tape was loaded at room temperature with a mass of 1 kg and shear resistance (in minutes) was determined as the average of three measurements.

[61] In addition, the relative stratification characteristics of the fissile substrate, coated on both sides with adhesive masses, were tested (C tesa test). As a comparative value, the stratification characteristics of the fissile substrate that was not coated with adhesive materials were used for this. For measurement, strips of coated and uncoated substrate 12 cm long were stored for 24 hours at 40 ° C, under load (2 kg / cm²). To carry out the measurement, the substrates were stratified over a 2 cm section and the force needed for further splitting of the substrates at a speed of 300 mm / min was measured. It was assumed that the test was met when the difference in forces needed to further split coated and uncoated substrates was less than 20%.

[62] The test results are presented for the upper self-adhesive mass 11 and for the lower self-adhesive mass 13 / adhesive mass 15 in table 1, with reference to the type of test used each time (tesa test).

Table 1:

<td>Self-adhesive mass (reference)</td><td>Adhesive force [N / cm] (test A)</td><td>Shear resistance (test B)</td><td>Relative dissection (C test)</td><td>Turning distance [mm] (test D)</td><td>Complex viscosity [Pa ^ s] (test F)</td>

<td>upper (11)</td><td> 8,2</td><td> &gt;10 000</td><td> --</td><td> 4</td><td> 25 000</td>

<td>bottom (13) connecting (15)</td><td> 2,0</td><td> &gt;10 000</td><td>fulfilled</td><td> 40</td><td> 16 000</td>

[63] Similarly to example 1, several other adhesive tapes according to the invention were made and measured, in which the upper mass has the following composition (total adhesive composition: 99% of the base adhesive, 0.5% of the original antioxidant (company type "Irganox 1010" Ciba) and 0.5% secondary antioxidant (type "Weston 339" from Interorgana), according to example 1). Compare with table 2.

Table 2:

<td rowspan="2">Przykłac</td><td rowspan="2">Base composition of upper self-adhesive mass (11)</td><td colspan="2">Adhesive force [N / cm]</td><td rowspan="2">Shear resistance [min.] (test B)</td><td rowspan="2">Turning distance [mm] (average value from 3 measurements) (test D)</td>

<td>steel (test A2)</td><td>Polyethylenes n (test A)</td>

<td> 2</td><td>45% Kraton D1118, 25% Dercolyte A115, 30% Wingtack 10</td><td> 11,6</td><td> 10,8</td><td> 8023</td><td> 3</td>

<td> 3</td><td>45% Kraton D1118, 30% Dercolyte A115, 25% Wingtack 10</td><td> 14,0</td><td> 12,4</td><td> 2750</td><td> 27</td>

<td> 4</td><td>50% Kraton D1118, 30% Dercolyte A115, 20% Wingtack 10</td><td> 14,0</td><td> 11,0</td><td> 14963</td><td> 8</td>

<td> 5</td><td>50% Kraton D1118, 25% Dercolyte A115, 25% Wingtack 10</td><td> 8,8</td><td> 8,8</td><td> 6337</td><td> 2</td>

<td> 6</td><td>45% Europrene SOL T-192, 25% Dercolyte A115, 30% Wingtack 10</td><td> 11,8</td><td> 8,0</td><td> 4809</td><td> 12</td>

<td> 7</td><td>45% Europrene SOL T-192, 25% Dercolyte A115, 30% Wingtack 10</td><td> 11,8</td><td> 8,0</td><td> 4809</td><td> 12</td>

<td colspan="6">All trade names: ®</td>

[64] The practical test of the use of adhesive tapes produced in this way for the dynamic replacement of polyethylene film rolls with a thickness of 35 μm to 60 μm was successful.