EP2303977A1 - Adhesive tape comprising a fabric support - Google Patents

Abstract

The invention relates to an adhesive tape especially an adhesive tape that is suitable for external applications. Said adhesive tape comprises a support which is produced of a 80 to 250 mesh fabric having a grammage of 50 to 150 g/m2 on top of which a weather-resistant plastic coating having an application weight of 15 to 75 g/m2 is applied and on the lower side of which, opposite the side provided with the plastic coating, a UV-stabilized self-adhesive mass of 70 to 200 g/m2 is applied, the adhesive tape especially having a thickness of at least 150 µm.

Description

 tesa SE Hamburg

description

Adhesive tape with a carrier of a fabric

The invention relates to an adhesive tape with a carrier made of a fabric.

Fabric adhesive tapes, consisting of a woven textile as a carrier material and a one-side applied layer of a self-adhesive, belong to one of the oldest types of self-adhesive systems as roll goods. Initially used in the medical field, in the second half of the last century they partly replaced soft PVC insulating tapes with the taping of cable harnesses in automobiles. Because of the extraordinary property combination of flexibility and conformability, high mechanical strength and simultaneous cross-tearability by hand, the range of applications has been greatly expanded. Tissue tapes can be used for bandaging, repairing, covering, fixing, marking etc. and can be cut to size by hand without scissors, knives or other aids. They are therefore universal tapes (so-called "multi-purpose tapes" or "general purpose tapes"), which are used on a variety of substrates, whether polar or non-polar, rough or smooth, and are used for almost all imaginable applications.

The adhesive is almost exclusively made from natural or synthetic rubber formulations. In addition to the historical aspect (natural rubber as the main constituent of the first industrially available self-adhesive compositions), it is in particular the adhesive properties that are balanced with respect to adhesion, tack and cohesion and are ideally suited for such universal adhesive tapes. The carrier materials used are dense woven textiles made of preferably (modified) natural fibers such as cotton, viscose rayon, viscose, etc. Initially, fabric adhesive tapes made of uncoated fabric, as raw fabric or dyed in the yarn, only one side coated with adhesive produced. Due to the open fabric structure, however, the rubber adhesive on the reverse side is easily attackable: oxygen, aggressive substances such as solvents etc. have almost unhindered access.

Therefore, and also to protect the fabric itself, plastic coatings were applied to the top of the tape. Three types of fabric adhesive tapes can be distinguished based on the product structure:

• The highest quality products to use a dense fabric having a basis weight of predominantly 70 to 150 g / m ² at a mesh count (sum of the threads in warp and weft direction, in each case per inch) in the order of 100 to 250 inch ^"2 with a mostly colored plastic coating of PVC, acrylate, polyurethane or similar, which is applied unilaterally from dispersions or organosols.These products have their origin in Central Europe and are mainly produced there.As an example of such a "premium tape" tesa® 4651 is mentioned here.

• More Asian origin are fabric adhesive tapes with a lighter, open, net-like fabric of 40 to 100 mesh on which a 50 to 200 micron thick PE film is extruded. Fabric and film usually form a stable, load-bearing composite. Because of their positioning in terms of price and characteristics, they are also referred to as "midgrades." As an example, tesa® 4688 can be considered here.

• Originating from North America, the so-called "duct tapes" have spread globally using very open fabrics, scrims or knits of 25 to 40 mesh with a basis weight of 15 to 40 g / m ² The durability of the film and textile carrier composite is determined solely by the adhesive strength and aging stability of the adhesive.This type of fabric tape is the lowest category in terms of price and is usually used in the color silver An example of the large number of commercial duct tapes is tesa® 4662. Such adhesive tapes generally have a total thickness of 200 to 400 .mu.m, wherein the adhesive layer contributes about 50 to 250 microns, and are structurally designed in principle for indoor applications.

As universal tapes, they are also used in outdoor applications. However, the effects of light, direct sunlight, moisture, heat, microorganisms, etc. then reveal weaknesses that can lead to damage to the adhesive tapes or their complete destruction:

• Rubber adhesives with reactive double bonds in the elastomers are destroyed by UV light and ozone and lose their original adhesive properties.

• Fabrics made of cotton, viscose, rayon etc. are attacked by microorganisms. In the presence of moisture, heat and light, this decaying component determines the mechanical properties of the adhesive tape.

• Water absorption in the fabric due to the absorbency of the yarns leads to swelling as well as to loss of strength due to swelling.

Previous attempts to develop suitable high-quality universal tissue adhesive tapes for long-term outdoor applications as so-called "outdoor tapes", have not been successful or only with some restrictions.

A high quality but expensive fabric adhesive tape having a dense 200 to 250 mesh viscose acetate fabric is described in US 3,853,598 A1. The fabric is provided with a polyacrylate primer layer to which an adhesive of synthetic and natural rubber is applied. Due to the very high mesh count fabric and the polyacrylate primer fabric finish, the tape has good and very easy hand tearability. However, there are no indications of outdoor suitability. The selected adhesive and in particular the upper side unprotected fabric based on modified natural fibers speak against it. Explicit only medical, that is called indoor applications.

A technical adhesive tape, in particular for the construction sector, is described in EP 1 548 080 A1. Although a weather-stable adhesive is used with a UV-crosslinked acrylate adhesive on a band-shaped carrier, but the Selecting substrates with papers, films, fabrics or nonwovens made of PE, PP or PET does not reveal any orientation towards outdoor applications. An easy hand tearability, as required for general purpose tape, is not available. Furthermore, in the case of UV-crosslinkable acrylate adhesives there is the latent risk that, under the influence of sunlight, an incomplete crosslinking set during production continues to run, and thus the adhesive properties change negatively during the period of use.

EP 1 736 582 A1 describes a polyester high-density multifilament fabric having excellent water resistance for umbrella coverings and the like. With a basis weight of at most 45 g / m ² , such a carrier for a universal adhesive tape is far too thin and would not meet the customer expectations for a universal fabric adhesive tape in terms of feel and appearance. Notes on tape applications are missing.

For reasons of cost and property, non-woven fabrics are also used instead of fabrics. With appropriate manufacture, weathering resistances and even good hand tearability can be achieved using PET fibers or filaments (see, for example, EP 0 389 212 A1 or EP 0 410 674 A1), but because of the low mechanical strengths, such systems are not an option for Universal Although improvements can still be achieved by the incorporation of filaments or loops as in EP 1 124 680 A1, the production is complex and costly, without the carrier comes close to the estimated, characteristic properties of tissue.

Known PE-coated fabric tapes (see above: PE film layer either extruded or laminated onto the fabric) such as in US 4,705,715 A1, US Pat. No. 4,654,254 A1, WO 2006/107054 A1, JP 2003 253 543 A1, EP 0 848 048 A1 or described in DE 602 17 908 T vary in product composition, but generally have in terms of habit, the mechanical strength and the UV stability of the PE films and the adhesives used clear deficits compared to the desired weather-resistant universal fabric tape. A technical adhesive tape with the focus on the use as a cable winding tape for automobiles is described in DE 20 2004 019 761 U. On a textile support such as fleece, fabric or suede, a plastic layer of polyurethane, in particular thermoplastic polyurethane (TPU), applied and coated with a standard in this field standard adhesive. It is a waterproof, textile tape with good abrasion resistance, with a good noise attenuation and with good media resistance obtained, as it is advantageous for the intended use. But not only due to the raw material TPU, the production is expensive and problematic for universal tapes, but also on cable taping tailor-made properties can be a use as General Purpose adhesive tape in the outdoor area not advisable.

The product structure according to the invention gives no UV resistance and - explicitly described in Example 1 (fabric tape) - insufficient hand tearability. The latter is not surprising to those skilled in such PU coatings. With an elongation at break of 30 to 40% in Example 1 described, the carrier made of fabric and PU layer is so soft and elastic that overstretching of the adhesive tape rather than tearing and straight-line tearing is achieved during normal hand tearing.

A special long-term outdoor tape which has less than 10% adhesive residue after 500 hours in the ASTM G155 weathering test is described in WO 03/097758 A1. Essential here is the multilayer PE plastic film on the top, which contains up to 35% sunscreen additives. For the other adhesive tape components such as a 10 to 90 mesh scrim and the self-adhesive, no special features are described. Therefore, it can be assumed that protection against (UV) light is achieved over a large area by the multilayer film on the surface, but access of oxygen, ozone, etc. at the edge can lead to undesired changes in the adhesive at the edges of the adhesive tape. In addition, in the described support structure of a 50 to 100 microns thick multilayer PE film and a clutch of 10 to 90 mesh with the typical Duct tapes, frayed tear edges to be expected, which are not accepted for a high-quality fabric adhesive tape. Furthermore, the high proportion of light protection additives and the multilayer film structure can be expected to result in correspondingly high production costs. EP 1 074 595 A1 describes a polyester fabric tape which is hand-tearable by the selection of special yarns and defined fabric construction (maximum 2500 dtex / cm as the titer of the longitudinal yarns per unit length) as well as by fixing the warp yarns as necessary by the adhesive coating , Thus, special conditions must be met in order to achieve at least a tear strength of less than 10 N in the transverse direction. For the person skilled in the art, the description of the yarn and fabric parameters is noticeably less than 100 g / m ² , which is not surprisingly inherently less strong by reducing the weight per unit area, but only in the following by the adhesive layer, the the warp threads must be fixed in place, hand tearable. Furthermore, a tear propagation resistance of below 10 N is erroneously linked to the property of hand tearability. In practice, in addition to the tear propagation strength described above, the force for the initial tearing of the carrier is of great importance for easy hand tearability, but this is significantly influenced by further parameters such as the tensile-elongation behavior of the wearer, the cutting technology and good used, etc. on which no information can be found in the disclosure.

DE 10 2005 044 942 A1 describes a transversely tearable adhesive tape with an uncoated textile fabric carrier based on polyester or polyamide, wherein the reduction of the fiber strength and thus the hand tearability by targeted damage to the yarn (in the case of PET with alkalis, in the case of polyamide with acids) he follows. By additional impregnation with slip solid chemicals such as silicates, the hand tearability is to be further improved. The alkalization of PET fabric, for example, is accompanied by a marked loss of strength, which is negatively affected by aging, thermal stress, bending and / or tensile loads, and with an increase in gas and vapor permeability. The latter in medical applications advantageous effect turns into technical applications to the contrary, since oxygen, ozone and similar aggressive gases and liquids can penetrate unhindered to the adhesive and thus damage them more than untreated or even coated fabrics. Although there are a variety of tissue tapes in both the technical, medical and consumer sectors, a high-quality, hand-tearable universal tissue tape is not known for long-term outdoor use.

Therefore, it is an object of the invention to eliminate the deficiencies of existing products and to develop a high quality in terms of look and feel, easy to produce in different colors, easily hand tearable fabric adhesive tape, which on a variety of common in daily use substrates even with prolonged use of at least six months in the outdoor area (Central Europe) does not lose its functionality. As a yardstick for this purpose, a change in the corresponding measured values of a maximum of 50% is used, for example for the maximum tensile strength and elongation at break in the longitudinal direction and the bond strength on steel according to AFERA 5001. Also significant changes in the appearance such as visible destruction or tears, Ver- or discoloration, detachment of the substrates are to be avoided.

This object is achieved by an adhesive tape, as laid down in the main claim. The subject of the dependent claims are advantageous developments of the invention.

Accordingly, the invention relates to an adhesive tape with a support made of 80 to 250 mesh PET fabric with a grammage of 50 to 150 g / m ² , on top of which a plastic coating, preferably an aqueous acrylate paste with an application weight of 15 to 75 g / m ^{2 is} applied and on the underside of which the plastic coating equipped side opposite, a UV-stabilized self-adhesive is applied with 70 to 200 g / m ² , wherein the adhesive tape preferably has a thickness of at least 150 microns.

For the purposes of this invention, the general term "adhesive tape" encompasses all planar structures such as two-dimensionally extended bands and two-dimensional bands limited width, band sections and the like, ultimately punched or labels.

It turns out that from a textile support, in which a closed, in particular coloring plastic coating is applied to a PET fabric, wherein the green fabric has a basis weight of more than 50 g / m ² , in particular from 70 to 130 g / m ² , when back-coated with a suitable, UV-stable self-adhesive, a correspondingly weather-resistant adhesive tape for the high-quality premium segment is obtained.

A thickness of preferably at least 150 μm, in particular 200 to 350 μm, meets the haptic expectations. Easy hand tearability can be achieved by using a carrier according to the invention and eliminates the need for cutting aids such as knives, cutters and the like. The colored plastic surface finish makes the tape look high quality.

The universal fabric tape according to the invention suitable for long-term outdoor applications is characterized by the following structure and manufacture, the description being considered as an example and can be used by a person skilled in modified form without thereby abandoning the scope of this application.

As a carrier most costly reasons undyed 80 to 250 mesh fabric with a grammage of 50 to 150 g / m ² , in particular from 70 to 130 g / m ² , selected by its special construction an at least moderate on and tearability per Hand in transverse direction [also referred to as weft direction or CD] has. This support is coated on one side with a colored, aqueous acrylate paste or the like at a coating weight of 15 to 75 g / m ² , in particular 25 to 50 g / m ² .

The tissue carrier is particularly advantageous if the coloring coating is applied in two lines in succession with two different formulations. The main portion is applied as a coloring base coat with 10 to 60 g / m ² directly on the fabric. By using an acrylate binder having a glass transition point of 0 ^° C. and less, a soft and elastic coating is obtained which has a positive effect on the flexibility and the grip of the wearer and promotes a cuddly adhesive bonding of the tissue adhesive tape. These sometimes slightly blocking (pressure-sticking) paint coats are applied in a second line 5 to 20 g / m ^{2 of} a hard, resistant top coat. Thus, the resistance of the adhesive tape surface increases both against its own adhesive (direct contact during manufacture, transport and storage as a roll of adhesive tape) and in the subsequent application against all possible influences such as mechanical stress, visible, infrared or ultraviolet radiation, water , Chemicals etc. The so-called topcoat is preferably selected from acrylate dispersions in which hardening comonomers such as, for example, styrene, methacrylate, acrylonitrile have been copolymerized. But other, light and chemical resistant, plastic films such as vinyl acetates, etc., which can be applied from dispersion or organosol, can be used as a topcoat.

The support according to the invention as a composite system of a PET fabric and more preferably acrylate coating not only has very good resistance to a variety of stresses, as they occur in connection with outdoor applications, but also compared to the raw fabric improved handling: easy penetration and tearability in the transverse direction without use of cutting tools as well as flexibility for contour-adapted bonding. With this composite carrier, a premium-grade tissue adhesive tape is obtained. The result is a high-quality appearance compared to the duct tapes and midgrades. Both the (acrylate) plastic coating and the higher mesh count of the fabric delimits the fabric tape according to the invention against the PE tapes coated with Duct Tapes and Midgrades.

According to the invention, 70 to 200 g / m ² , in particular 80 to 150 g / m ² , of a UV- and moisture-resistant self-adhesive are applied to the opposite side as adhesive layer in order to ensure secure bonding in interior and exterior applications on smooth, structured and rough substrates , Modified acrylate adhesives and completely or partially hydrogenated styrene-butadiene-styrene block copolymer systems (SBC) or styrene-1-styrene block copolymer systems, in particular formulations with partially hydrogenated styrene-butadiene / butylene-styrene (SBBS) as the elastomer component, are particularly advantageous as adhesives. With this product construction according to the invention, tissue adhesive tapes are obtained which adhere well and securely to the different adhesive substrates. On steel as a standard adhesive substrate for polar substrates, a bond strength in the fresh state (maximum one week after production) of 3.5 N / cm minimum and on polyethylene as non-polar substrate a bond strength in the fresh state of at least 2 N / cm is reached, as required at least 50% over six months.

From most of the common adhesive substrates, the adhesive tape can be removed without residue or with minimal residues without destroying the carrier after up to six months of use. A lengthy removal of fragments or adhesive residues, optionally with the aid of solvents, which can attack the substrate surface, thus eliminating in contrast to previous fabric tapes such as duct tapes and Midgrades, where this is the case and understandably leads to displeasure among the users.

Such universal fabric tapes according to the invention can be easily cut to length in the transverse direction with a straight tear edge without fraying by hand. In the machine direction, however, the fabric tape has high strengths and can thus be used for many bandaging and fixing applications where tensile strength is important. Usually a slightly higher initial force is required for tearing the edge, wherein the further tearing can then be done easily and evenly. This slightly increased tearing strength advantageously protects the fabric tape against accidental tearing during handling and in the final application.

In outdoor applications, the universal tissue adhesive tape according to the invention proves to be extremely stable and suitable for long-term use of at least six months. While, in particular, the duct tapes break down into their constituents after a few weeks on direct exposure to sunlight and rain, the functionality and product integrity of the fabric tape according to the invention remain the same:

Sufficient strength for mechanical stresses,

• good adhesion to the substrate and

• if necessary, after the end of the application the possibility for a largely residue-free removal of the adhesive tape.

Especially the latter is not given in the known natural rubber and Synthesekauschuk- fabric tapes, since the attack on the double bonds the Scaffolding elastomer is destroyed and the adhesive passes through phases depending on the formulation and stress, where the adhesive from soft and flowable to hard and dry and in one form or another resists the redetachment.

When using a carrier material according to the invention, such an adhesive tape has a high-quality appearance. A dense fabric structure, as with apparel fabrics, instead of open, thinned, net-like structures as in the Duct Tapes, combines with a high-quality plastic surface that is significantly different from the "cheap" PE film surfaces of the Midgrades and Duct Tapes combined with a surprisingly positive combination high tensile strength / hand and tearability and weather resistance to both UV, sunlight and moisture.

With a suitable selection of the individual components and formulation for the adhesive, a tape which adheres well to a wide variety of substrates is obtained, which can also be used for outdoor applications for a prolonged period of time without noticeable deterioration of the properties. Suitable adhesives include: polyacrylates and systems based on rubbers without unsaturated double bonds, but also known rubber adhesives with correspondingly improved UV stabilization.

Despite the inherently good mechanical and haptic properties, it is not possible to recommend (modified) natural fibers such as cotton, viscose or rayon for longer-lasting outdoor applications, since in addition to loss of strength under the influence of moisture degradation by microorganisms is to be expected. Fibers of synthetic polymers such as polyester (PET, PBT, PEN), polyacrylates, polyamides, polyimides, polyethylene, polypropylene, etc. are more advantageous. In particular, PET as a material offers itself, since it rot-proof, sufficiently UV and moisture-stable and commercially available in the textile sector worldwide and inexpensive available in the form of fibers and continuous filaments.

For technical applications such as cable bandaging, PET fabric tapes have been used since the nineties, whereby in addition to the resistance to rot and higher endurance and peak temperature resistance, the high mechanical strengths (for example tensile, but also anti-abrasion) were decisive. However, PET fabric tapes such as tesa®51006 or 51026 are not hand tearable, but must be cut to length with knives, scissors, dispensers, etc. First, but only to a limited extent, hand-tearable PET fabric adhesive tapes were introduced a decade ago, with a marked reduction in basis weight to 70 g / m ² and less and additional processing such as quenching (friction calendering) to lower the strength - such fabrics However, they are very thin and are perceived by the users rather than foil-like than as tissue, so that a suitability for the high-quality universal tissue adhesive tapes is eliminated. The suitability in outdoor applications is not ensured.

However, by judicious choice of the yarns, the fabric construction and the process steps, it is also possible PET fabrics in the desired grammage range of 50 to 150 g / m ² , in particular 70 to 130 g / m ² , at thicknesses of less than 100 to 250 microns to produce with satisfactory hand and tear properties. With the method described in DE 10 2005 044 942 A1 for damaging the yarn, the strengths are purposefully reduced so that a balanced ratio of the remaining maximum tensile force in the warp direction and the tearability can be adjusted.

Alternatively, the fabric may be constructed so that the warp that must be severed in the later fabric when transversely torn is selected so that the individual warp yarns allow this without undue effort: either the yarn cross section is reduced so that tearing is possible without problems is, or through the choice of material for the chain acceptable cut-through behavior is set. In order to achieve sufficient overall machine direction (MD) in the subsequent fabric, the number of threads per unit length should be selected to achieve the desired maximum MD of at least 40 N / cm and a maximum of 100 N / cm. Ideally, for the universal fabric adhesive tape, a maximum tensile strength MD of 60 to 80 N / cm is to be aimed for. For example, PET yarn of 75 denier or finer denier is suitable for the warp, but also brittle materials which result in breakage of the warp when the energy is impulsively introduced during tearing: PET fibers with suitable comonomers or crystallization or else warp yarn based on PA6 .6. In order to obtain in such chains a tissue with the desired feel and appearance, the weft threads must be correspondingly thicker and heavier. As a result, on the one hand, the basis weight increases in the range of 70 g / m ² and more, on the other hand, the desired thicknesses for the fabric achieved from 100 to 250 microns; The fabric also has a high-quality finish, despite the thin warp threads, because the thicker weft threads determine the look. PET shotgames starting at 150 are possible, but a 300 denier is particularly advantageous in terms of look and feel

PET yarn.

The same applies to the use of other synthetic polymers instead of

PET as a material for the yarn.

A further possibility of producing a base fabric according to the invention with an acceptable transverse and tearability in the transverse direction is, in particular for the warp, to use yarns of a fiber mixture, wherein at least one of these types of fibers is soluble and thus subsequently removable. Thus, a yarn with sufficient strength for the spinning and weaving process would be present, and thinning and weakening would occur only in a subsequent process step, resulting in the desired transverse tearability to the fabric. As fiber blends, a variety of combinations are conceivable, with the use of resistant polymers as a permanent warp yarn such as PET fibers in combination with water-soluble or chemically or enzymatically degradable materials such as polyvinyl alcohol, polylactates and the like. Depending on the selected fiber combination, the mixing proportions should be selected so that the final strength of the (warp) yarn is within the target range.

Further textile layers can be applied to the fabric carrier, wherein all layers and the fabric are sewn in particular by threads running parallel to one another.

The other textile layers may consist of fabrics which are similar to those used according to the invention, but they may be formed from other fabrics or nonwovens.

Although self-adhesive tapes can be made with such uncoated fabrics, a premium universal fabric tape requires a high quality single-sided plastic coating. This achieves a smooth, homogeneous surface and closes the fabric so that aggressive chemicals are kept away from the adhesive and the bonding substrate. Furthermore, a cost-effective and flexible coloring of this coating, since a dyeing of the fabric itself is more complex. Surprisingly, in addition to these known aspects, the color coating according to the invention markedly improves the hand tearability of the raw tissue with suitable formulations, so that related claims on the tissue itself can be reduced. In the case of the one-sided coating with a suitable color paste on the upper side, this coating penetrates into the tissue at least with half the thickness of the fabric due to the three-dimensionally structured surface. After drying or hardening of the plastic layer, the warp and weft threads are geometrically fixed, similar to what EP 1 074 595 A1 urges for the warp threads through the adhesive coating.

In principle, a variety of systems are possible for the plastic coatings: organosols, radiation-crosslinkable prepolymer systems, non-adhesive hotmelts, polymer solutions, etc. By contrast, aqueous dispersions are preferred and established for reasons of cost, availability and existing standard application technologies in the textile sector.

As materials, for example, polyurethanes, (ethylene) vinyl acetate, PVC, styrene-butadiene or acrylate systems can be selected. For reasons of ecology, cost, availability and with regard to the requirement "outdoor use / weather resistance ¹ , acrylates are to be preferred. These are thickened depending on the existing coating technology and dispersed with appropriate color pastes / pigments to produce the colorant one-sided coating.

To have a good "grip of the final fabric tape, that is comfortable touch, cuddly and flexible behavior, so that the tape can be well glued even on curved, uneven surfaces, should the coloring Bottom line to be soft and flexible. The glass transition temperature for the binder in the color paste should be below room temperature, in particular in the range of 0 ^C C or lower.

For good resistance of the adhesive tape, on the other hand, a hard, chemically resistant topcoat is favorable. Such a topcoat not only protects the layers underneath but, if properly selected, also acts as a barrier layer against the adhesive, which in the subsequent adhesive tape roll is in direct contact with the topcoat Interactions such as migration of components of the adhesive into the plastic coating or vice versa are undesirable because they lead to changes in the respective properties and in extreme cases, the defined interface between the adhesive and plastic surface is dissolved. The consequence of this would be a strong mounting of the adhesive and thus high unwinding forces. Topcoats, in particular acrylate-based, having a glass transition temperature above room temperature, in particular from 30 to 50 ⁰ C and above, are suitable, as well as chemically or thermally crosslinking systems, if the final film properties are in the same range. However, the topcoat must not be too hard, so that no cracks occur during bonding around tight radii due to bending or bending in the topcoat, thus damaging the closed lacquer layer.

The coloring plastic coating is at 15 to 75 g / m ² , in particular 20 to 50 g / m ² , to apply overall, in order to achieve a good color, closed layer and a uniform surface structure. For reasons of low complexity, it has proved favorable to apply the base coat pigmented with 70 to 95% of the total amount as a coloring layer and the topcoat with 5 to 30% as unpigmented , transparent topcoat. With regard to formulation and process parameters, care must be taken that on the one hand the adhesion of the base coat to the raw fabric is high and, on the other hand, the bond between the base coat and the topcoat so that the subsequent adhesive tape does not tearing or peeling off the coloring plastic layer, for example during unrolling from the role.

With a suitable choice of the topcoat and the adhesive can be dispensed with an additional release coating. If necessary, if, for example, a slight unwindability of the adhesive tape roll is desired, one or more release additives may be added to the topcoat or else a separate release coating / printing may be selected. However, since a unwinding force (at take-off speeds of 0.3 m / min) of 2 to 8 N / cm is favorable for pleasant handling and has also become established, the use of additional anti-adhesive components can normally be dispensed with. For the adhesive coating is in principle a series of adhesive systems in question. In addition to good adhesion and adhesive properties on a wide range of different substrates, the adhesive must provide sufficient stability against UV radiation, sunlight, oxygen, moisture, etc., ie, requirements that occur in outdoor applications.

Adhesives based on silicones, polyolefin systems such as polyisobutylene, bitumen, polyurethanes, polyvinyl acetates and acrylates can be used, but also established natural and synthetic rubber adhesives, if in particular the sensitivity of the elastomers in the double bonds is eliminated by appropriate light and aging inhibitors.

For reasons of cost, availability and also the adhesive properties in daily use as General Purpose Tape preferably acrylates and stabilized natural and synthetic rubber systems are used. Since the adhesive layer is protected by the carrier material against moisture, UV radiation, etc., and only a small part, especially at the edge of the adhesive tape, is even directly attacked, the requirements for the adhesive are lower than, for example, with adhesive tapes with open fabrics or UV permeable films as a carrier material.

Acrylic adhesives are stable to UV radiation per se, stick very well to polar substrates, but have weaknesses on non-polar substrates. These deficiencies can be at least partially compensated for by admixing with the pure acrylates suitable resins or additives which improve the flow and adhesion to non-polar substrates such as polyethylene or polypropylene. Acrylate adhesives can be applied both from solution, as a hotmelt, as a prepolymer or as a dispersion. In the case of dispersions, due to the moisture contact in outdoor applications, sufficient water resistance of the adhesive must be ensured. While dispersions used to have pronounced moisture sensitivities because of the emulsifiers, modern acrylate dispersions are significantly improved and suitable for such applications. When using radiation-crosslinkable, in particular UV-crosslinkable acrylates, it must be ensured that the degree of crosslinking remains stable and can not change significantly in outdoor use. Crosslinking under the influence of solar radiation could alter adhesive properties, such as reducing the bond strength, so that applications may not be safely operated over longer periods of time. However, rubber adhesives are predominantly used for universal woven tapes since they show a good combination of adhesive strength, tack and cohesion and a balanced adhesive behavior on virtually all relevant adhesive substrates and are therefore predestined for this purpose. However, because of the large number of double bonds, elastomers composed of butadiene or isoprene units are very sensitive to UV light, ozone, etc. as well as thermally induced oxidation. The scaffold polymer is attacked at the double bonds and partially crosslinked, but also degraded, which can lead to massive changes in adhesive properties: softening of the adhesive to honey-like flow or laking by three-dimensional networking, that is, complete loss of self-adhesive properties. General information on rubber adhesives can be found, inter alia, in standard works for adhesive tapes, such as Donatas Satas'"Handbook of Pressure Sensitive Adhesive Technology." Even though natural rubber adhesives, which are standard for conventional universal tapes (Duct Tapes, Midgrades, Premium Tapes), However, because of UV protecting additives such as carbon black, titanium dioxide, light stabilizers such as HALS (Hindered Amine Light Stabilizer) and the like, the variety of double bonds in the backbone remains a weak point, so that such high-demand systems are not the first Represent choice.

It is more advantageous to use hydrogenated or at least partly hydrogenated styrene-butadiene block copolymers (SBC) as the elastomer component (the same applies to the use of styrene-isoprene copolymers). For example, as reported in the review "An Overview of Styrenic Block Copolymer Adhesives" [Edward M. Petrie, Adhesives & Sealants, www.specialchem4adhesives.com], an improvement in long-term stability against thermal and photooxidative processes can be achieved when using saturated SBCs : Styrene-ethylene-butadiene-styrene (SEBS) as hydrogenated SBS or styrene-ethylene-propylene-styrene (SEPS) as hydrogenated SIS The elastomers hydrogenated in the soft segment have good stabilities, but are altered in their adhesive properties, in part due to appropriate formulation can be compensated. However, it is more advantageous to use partially hydrogenated elastomers for the premium universal fabric adhesive tapes according to the invention, which combine very good adhesive properties with good outdoor weathering properties. In the preparation of vinyl aromatic-based block copolymers, preferably styrene and 1,3-dienes, especially isoprene and butadiene, both 1, 2 and 1, 4-linked dienes are incorporated in the diene block. The proportion of 1,2-dienes can be controlled by the process control. Since the 1, 2-linked dienes contain a terminal double bond, while the double bond is in the 1, 4-linked dienes in the main chain, a selective hydrogenation of the terminal and thus more reactive double bonds is possible.

DE 102 52 089 A1 describes adhesives based thereon for pressure-sensitive adhesive film strips which can be detached again under stretching and without destruction. Surprisingly, by means of suitable formulation based on these partially hydrogenated SBC elastomers, self-adhesive compositions for the universal fabric tape can be developed which fulfill both the requirement for secure bonding to different substrates and good long-term stability in outdoor applications.

The adhesive preferably consists of

• at least one block copolymer P1 having one or more terminal blocks consisting of vinylaromatic compounds and at least one block consisting of conjugated dienes, in which the terminal double bonds, formed by 1,2-linkage, are hydrogenated to more than 80%, while the double bonds in the Main chain, formed by 1, 4 linkage, are hydrogenated to less than 30%, and

• at least one block copolymer P2 having one or more terminal blocks consisting of vinylaromatic compounds and at least one block consisting of conjugated dienes in which at least 95% of the double bonds are hydrogenated.

In an advantageous embodiment, the block copolymers have a Polyvinylaromatenanteil of 10 wt .-% to 35 wt .-%. In a further advantageous embodiment, the proportion of the two vinylaromatic block copolymers in total based on the total adhesive is 20 to 70 wt .-%, preferably 30 to 60 wt .-%, most preferably 35 to 55 wt .-%.

In the preparation of block copolymers based on vinylaromatics, preferably styrene and 1,3-dienes, especially isoprene and butadiene, the dienes are incorporated in the diene block both 1, 2 and 1, 4-linked. The proportion of 1,2-linked dienes can be controlled by the solvent, the temperature or the catalyst. Since the 1, 2-linked dienes contain a terminal double bond, while the double bond is located in the 1, 4-linked dienes in the main chain, a selective hydrogenation of the terminal and thus more reactive double bonds is possible.

The block copolymers used are polymers comprising blocks of vinylaromatic (A) blocks such as styrene and others formed by polymerization of 1,3-dienes (B blocks) such as butadiene and isoprene or a mixture from both. In this case, the B blocks are polymerized so that they have a high proportion of vinyl groups by a 1,2-linkage of more than 20%, which are hydrogenated in contrast to the double bonds in the main chain. When the non-hydrogenated block copolymer is an SBS, a so-called SBBS (styrene-butadiene / butylene-styrene) is produced after the selective hydrogenation. Since the selectivity of the hydrogenation is not 100%, block copolymers may be used whose vinylic double bonds, formed by 1, 2-linkage, are hydrogenated to more than 80%, while the double bonds in the main chain are hydrogenated to a maximum of only 30%.

The second component used are block copolymers which on the one hand comprise blocks of vinylaromatics (A blocks) such as, for example, styrene and on the other those formed by polymerization of 1,3-dienes (B blocks) such as butadiene and isoprene or a mixture from both, with the entire double bonds of the B blocks are hydrogenated to a proportion of over 95%.

The block copolymers may have linear ABA structure. It is also possible to use block copolymers of radial form as well as star-shaped and linear multiblock copolymers. As a further component AB two-block copolymers can be used. Instead of the preferred polystyrene blocks and polymer blocks based on other aromatics-containing homopolymers and copolymers (preferably Ce to C ₁₂ aromatics) with glass transition temperatures of greater than about 75 ⁰ C are used, such as α-methylstyrene-containing aromatic blocks.

The two elastomers, partially hydrogenated P1 and at least 95% hydrogenated P2, according to the invention are present in a ratio (weight proportions) of 25:75 to a ratio of 90:10, preferably in the range of 40:60 and 80: 20th

Adhesive resins which are compatible with the elastomer block of the vinylaromatic block copolymers serve as tackifiers. Suitable tackifier resins include, inter alia, preferably nonhydrogenated, partially or fully 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 polyterpene resins based on α-pinene and / or β-pinene and / or δ-limonene. The aforementioned adhesive resins can be used both alone and in admixture.

Both solid and liquid resins can be used at room temperature.

To ensure high aging and UV stability, hydrogenated resins are preferred.

As further additives can typically be used:

Plasticizers such as plasticizer oils or low molecular weight liquid polymers such as low molecular weight polybutenes

• primary antioxidants such as sterically hindered phenols

• secondary antioxidants such as phosphites or thioethers

• Process stabilizers such as C radical scavenger

• Sunscreens such as UV absorbers or hindered amines

• Fillers such as fibers, carbon black, zinc oxide, titanium dioxide, micro-solid spheres, solid or hollow glass spheres, silica, silicates, chalk

• processing aids • Endblock amplifier resins as well

Optionally further polymers of preferably elastomeric nature; correspondingly useful elastomers include, but are not limited to, those based on pure hydrocarbons such as unsaturated polydienes such as natural or synthetically produced polyisoprene or polybutadiene, chemically substantially saturated elastomers such as saturated ethylene-propylene copolymers, α-olefin copolymers, polyisobutylene, butyl rubber, ethylene Propylene rubber and chemically functionalized hydrocarbons such as halogen-containing, acrylate-containing or vinyl ether-containing polyolefins, to name but a few.

It is also according to the invention if the adhesive does not have all the additives mentioned.

The preparation and coating of the adhesive can be carried out from solution, dispersion and from the melt. Preference is given to working from solution and from the melt. Particularly preferred is the preparation of the adhesive from the melt, using batch as well as continuous processes are used. Particularly advantageous is the continuous production by means of an extruder.

Almost independent of the type of adhesive used, a universal fabric tape according to the invention requires a certain layer thickness for the adhesive in order to securely adhere even to rough or structured adhesive substrates such as wood, stone, concrete, etc. With a mass application of 70 to 200 g / m ² , the desired adhesive behavior is achieved. Among other things, the absolute amount of the effective layer thickness depends on the structure of the fabric: Depending on the roughness of the side to be coated, amounts of up to 50 g / m ^{2 are} required, solely to fill in the depressions in the tissue, without this part of the adhesive A rough orientation for the mass requirement for the desired adhesive behavior is an "effective" layer thickness of 60 to 150 μm. Depending on the type of adhesive and its dosage form, the coating technology must be selected. Here can be used on known systems such as squeegees, rollers, nozzles, etc. The appropriate choice can be made by a person skilled in the art without any problems. While in many cases the combination of adhesive / coating technology leads to a sufficient penetration of the adhesive into the recesses of the tissue and thus for a good anchorage of the adhesive layer on the support, in cases where an adhesive layer as a film, for example, pulled out of the nozzle and only is applied, by additional use of pressure and temperature for a more intense and lasting contact between the two layers are taken care of. This can be achieved by a downstream printing and pressing process such as by a calendering station. Alternatively, however, this can also be achieved by a carrier pretreatment, such as, for example, by an additional primer coat, which physically / chemically strengthens the adhesion and anchoring of the adhesive to the carrier.

Drying, crosslinking, curing of the adhesive layer follow as needed and are well known in the art.

Due to its outstanding properties, the adhesive tape according to the invention is particularly suitable for outdoor applications in, for example, the home and garden. If the tape is exposed to UV rays and the weather, the benefits come into play. Even pest attacks can damage the tape little.

Test Methods

adhesive power

The determination of the bond strength was carried out as follows. As a defined primer, a steel surface, a polyethylene surface (PE) and a 150 grit sandpaper were used. The glued surface element to be examined was cut to a width of 20 mm and a length of about 25 cm, provided with a handling section and immediately thereafter pressed five times with a steel roller of 4 kg at a feed rate of 10 m / min on the selected primer. Immediately thereafter, the glued surface element was at an angle deducted from 180 ° from the primer with a tensile testing device (Zwick) and measured the force required for this at room temperature. The measured value (in N / cm) was the average of three individual measurements.

UV test

To measure the UV stability, the samples were glued in 20 mm wide and 25 cm long on a glass plate with a thickness of 4 mm and rolled five times with a 2 kg roll.

The samples were stored with the glass side up in a UV chamber with xenon lamp at an irradiance of 300 W / m ² . Each day, a new strip was removed from each UV chamber per sample and removed from the glass plate after conditioning to room temperature for 1 hour.

It was noted whether there were noticeable changes, rupture or adhesive residue on the glass plate.

weathering test

As a quick test instead of the protracted outdoor weathering, the so-called "Suntest" was carried out in accordance with ISO 4892-2 (2006) by gluing samples to hard PVC, glass and PE and a combination of UV irradiation using a 765 Watt xenon lamp In the two-hour cycles, after irrigation and irradiation for 18 minutes, there was a period of 102 minutes irradiation without irrigation.

After the weathering time, the strips were visually evaluated after reconditioning to room temperature, then stripped at 90 ° and 180 ° and evaluated for tearing and residue. According to the manufacturer (for example, company Atlas) corresponds to a week Suntester about 3 months weathering in Central Europe.

As far as the withdrawn test strips allowed, the adhesive force after storage was determined hereof.

Sporadically carried out long-term tests under real external conditions (natural weathering) took place in Hamburg on the same grounds on a building roof with south orientation at an inclination angle of 45 °. The results were comparable to the above-mentioned quick tests. In the following, the invention is explained in more detail by means of a few examples, without wishing to restrict the invention thereby.

Examples

example 1

A black PET fabric with plain weave, a thread count of 31 cm ^"1 in the chain, 22 cm ^'1 in the weft, with 75 the yarn in the warp and 300 the yarn in the weft, points to the continuous alkalization according to DE 10 2005 044 942 A1 with a basis weight of 100 g / m ^2, a maximum tensile force on the warp direction of 70 N / cm. one side a black pigmented acrylic dispersion at a coverage of 35 g / m ² is coated. The virtue of their low T _g -value soft and Blocking-prone coating is then immediately coated with a transparent topcoat based on a hard acrylate dispersion with a coverage of 10 g / m ² covering and dried so that the self-crosslinking topcoat is cured.

The tearability and especially the tearability in weft direction from the edge are significantly improved by this coating. The carrier material is "hand-tearable".

On the open fabric side, 75 g / m ² Acrylathotmeltmasse (acResin® 204 from BASF with 15 wt .-% resin Foral® 85) coated and UV-crosslinked with 35 mJ / cm ² ; the adhesion to polyethylene, which is slightly below target, can be raised to the target area without problems by the person skilled in the art by modifying the resin component and / or increasing the mass application.

Example 2

The support material of Example 1 is mixed with 110 g / m ^{2 of} a synthetic rubber

Hot melt adhesive coated, consisting of

44% by weight of elastomer content (3/4 Tuftec® P 1500, a partially hydrogenated SBS block copolymer from Asahi with 30% by weight block polystyrene content, and 1/4 Kraton® G 1657, a SEBS block copolymer from Kraton with a Diblock content of 35% by weight and a block polystyrene content of 13% by weight),

42% by weight of the hydrogenated C ₉ resin Regalite R 1090 from Eastman,

12 wt .-% of a liquid resin (Regalite R 1010 from Eastman) and

• 2% by weight of anti-aging agent and UV absorber,

In each case 0.5% by weight Irganox 1010 and Irgafos 168 as well

1% by weight of Tinuvin P.

The material meets all criteria for a premium fabric tape according to the invention.

Example 3

Comparable to Example 2, a raw fabric with a rib weave is used here alternatively, that a 22-gauge PA 6,6-Gam is used as warp and a 150 uses the PET yarn with a thread count in the warp of 42 cm ^"1 and 44 cm ^"1 in the shot

The maximum tensile force is at 40 N / cm on the edge of the desired target area, but this is associated with excellent cross-tearability. For the invention

Use as a premium fabric tape but can in principle maximum traction and

Tear strength can be counterbalanced by a thicker warp yarn and / or increasing the

Thread count in the warp direction to achieve at least a maximum tensile force of 50 N / cm and more. The adhesive coating is carried out as in Example 2.

In the UV and weathering tests, the pattern shows similar, slightly worse

Results as example 2.

Counterexample 4

A 90 g PET fabric with plain weave has a thread count of 50 cm ^-1 in the warp with a standard yarn and a thread count of 32 cm ¹ in the weft with a yarn of 150. According to the plastic coating according to the invention, the support has a maximum tensile force of 118 N / cm and can only be tearing under unacceptable high force and therefore not suitable for use with the universal fabric tape insert The backing material is classified as "non-hand tearable". The adhesive coating is carried out as in Example 2. Counterexample 5

Counterexample 5 corresponds to a commercial fabric tape made of cellulosic with a standard natural rubber adhesive.

A 150 mesh viscose fabric (about 110 g / m ² gray fabric; symmetrical plain weave with Nm50-yarns in warp and weft) with upper, pigmented acrylate (60 g / m ²⁾ and rear-side natural rubber coating (110 g / m ^2, no special UV -Stabilisierung) can be easily torn, sticks well on different surfaces, but has serious shortcomings in the UV and weathering tests after a short exposure time. Because of its composition, the tape is easily attacked and destroyed by microorganisms, it is unsuitable for outdoor use.

Table:

Only example 2, with a good combination of hand tearability, high mechanical strengths, balanced adhesion, weather resistance, and residue-free resistance to repellency after extended use, is a true premium outdoor fabric adhesive tape. With limitations on residue-free resistibility and lower adhesive strength on nonpolar substrates This is also the case for example 1. Here, however, the specified bond strength target values can be set by optimizing the resin content in terms of type and amount. Example 3 has weaknesses in the mechanical tensile load in the warp direction due to reduced physical strength values, but this can be counteracted with appropriate modification of the fabric construction. By contrast, the counterexamples lack either the essential properties of hand tearability (No. 4) or the required UV and weather resistance (No. 5).

Claims

claims

1. Adhesive tape, in particular suitable for outdoor use, with a support of 80 to 250 mesh fabric having a grammage of 50 to 150 g / m ² , on top of which a weather-resistant plastic coating having an application weight of 15 to 75 g / m ^{2 is} applied and on the underside of which the plastic coating-equipped side opposite, a UV-stabilized self-adhesive composition is applied with 70 to 200 g / m ² , wherein the adhesive tape in particular has a thickness of at least 150 microns.

2. Adhesive tape according to claim 1, characterized in that the plastic coating is applied in two layers, wherein a first, is applied directly on top of the fabric with 10 to 60 g / m ² , the at least one acrylate binder with a glass transition point of 0 ^0th C and less, and wherein on the first layer a second layer of 5 to 20 g / m ^{2 is applied} in the form of a hard, resistant topcoat.

3. Adhesive tape according to claim 1 and 2, characterized in that the fabric consists of fibers of synthetic polymers such as polyester (PET, PBT, PEN), polyacrylates, polyamides, polyimides, polyethylene or polypropylene, in particular PET.

4. Adhesive tape according to at least one of claims 1 to 3, characterized in that further textile layers are applied to the fabric carrier, wherein all layers and the fabric are sewn in particular by mutually parallel threads.

5. Adhesive tape according to at least one of the preceding claims, characterized in that the adhesive is a UV and weathering stable adhesive such as an acrylate composition, a UV-stabilized rubber system or a butyl rubber composition is used.

6. Adhesive tape according to at least one of the preceding claims, characterized in that as an adhesive modified acrylate as well as completely or partially hydrogenated styrene-butadiene-styrene block copolymer systems (SBC) or styrene-isoprene-styrene block copolymer systems, especially formulations with partially hydrogenated styrene-butadiene / Butylene-styrene (SBBS) can be used as the elastomer component.

7. Adhesive tape according to at least one of the preceding claims, characterized in that the adhesive used is an adhesive consisting of at least one block copolymer P1 with one or more terminal

Blocks consisting of vinyl aromatics and at least one block consisting of conjugated dienes in which the terminal double bonds formed by

1, 2 linkage are hydrogenated to more than 80%, while the double bonds in the main chain, formed by 1, 4-linkage, are hydrogenated to less than 30%, and at least one block copolymer P2 with one or more terminal

Blocks consisting of vinyl aromatics and at least one block consisting of conjugated dienes in which at least 95% of the double bonds are hydrogenated.

8. Adhesive tape according to at least one of the preceding claims, characterized in that the UV-stabilized self-adhesive is applied with an adhesive application of 80 to 150 g / m ² .

9. Adhesive tape according to at least one of the preceding claims, characterized in that the warp yarn has a maximum of 75 the thickness and / or the breaking force in the warp direction between 40 and 100 N / cm, in particular between 40 and 80 N / cm.

10. Adhesive tape according to at least one of the preceding claims, characterized in that As a weather-resistant plastic coating, an aqueous acrylate paste is used.

11. Adhesive tape according to at least one of the preceding claims, characterized in that the properties tear strength and elongation at break and the bond strength on AFERA 5001 steel after 2 weeks Suntest according to ISO 4892-2 (2006) drop to a minimum of 50% of the initial value.

12. Use of an adhesive tape according to at least one of the preceding claims for outdoor applications in, for example, home and garden.