DE102019211874A1 - Adhesive tape for sheathing elongated goods, in particular cable sets and methods for sheathing - Google Patents

Abstract

The invention relates to an adhesive tape, in particular for wrapping cables, comprising a preferably textile carrier and a pressure-sensitive adhesive in the form of a dried polymer dispersion applied to at least one side of the carrier, the polymer being composed of: (e) 70.0 to 90, 0% by weight of n-butyl acrylate and / or 2-ethylhexyl acrylate (f) 10.0 to 20.0% by weight of one or more ethylenically unsaturated monomers, with at least 50.0% by weight of the ethylenically unsaturated monomers (monomer (b)) Methyl methacrylate comprise (g) 0 to 10.0% by weight of another ethylenically unsaturated monomer other than monomer (b) (h) 0 to 5.0% by weight of an ethylenically unsaturated monomer with an acid or Acid anhydride function and the pressure-sensitive adhesive contains between 3 and 20 parts by weight of tackifier (based on the mass of the dried polymer dispersion), the tackifiers having a softening point above 90 ° C. according to ASTM E28-99 (2009).

Description

The invention relates to an adhesive tape for sheathing elongated material such as, in particular, cable harnesses in automobiles and methods for sheathing.

Adhesive tapes have been used in the industry to make wire harnesses for some time. The adhesive tapes are used to bundle a large number of electrical cables before installation or in an already assembled state, for example to reduce the space required by the cable bundle by bandaging and to achieve additional protective functions such as protection against mechanical and / or thermal stress.

Common forms of adhesive tapes include film or textile backings, which are usually coated on one side with pressure-sensitive adhesives. Adhesive tapes for sheathing elongated goods are for example from the EP 1 848 006 A2 , the DE 10 2013 213 726 A1 and the EP 2 497 805 A1 known.

The testing and classification of adhesive tapes for cable sheathing is carried out in the automotive industry according to extensive standards such as LV 312-1 “Protection systems for wiring harnesses in motor vehicles, adhesive tapes; Test guideline "(10/2009) as a common standard of the companies Daimler, Audi, BMW and Volkswagen or the Ford specification ES-XU5T-1A303-aa (revision 09/2009)" Harness Tape Performance Specification). In the following, these standards are abbreviated as LV 312 or the Ford specification.

The noise reduction, the abrasion resistance and the temperature resistance of an adhesive tape are determined using defined test setups and test methods, as described in detail in LV 312.

Cable wrapping tapes are widespread with film and textile backings, which are usually coated on one side with different pressure-sensitive adhesives.

In addition to a number of requirements such as chemical compatibility, high adhesive strength, compatibility with changing substrates that are placed on adhesive tapes, uneven, uneven substrates must also be reliably bonded in the automotive industry by means of cable harnesses, corrugated pipes and branches. In addition, there are bending and tensile stresses during manufacture, installation and subsequent use in the engine compartment of an automobile or in the body with constant bending stresses when opening doors.

Since the end of the adhesive tape is ideally glued to its own back, there must be a good instant adhesive force (tack) on this substrate so that the adhesive tape does not flag at the beginning. In order to permanently guarantee a flagging-free product, the anchoring on the subsurface and the internal strength of the adhesive must be so pronounced that the adhesive connection is able to withstand the influence of tension (tensile and flexural loads).

When winding a cable set, the adhesive tape is glued around the cable, from not at all to completely overlapping, which usually has a small radius, so that the adhesive tape is very strongly curved. At the end of a winding section, the tape is usually wound predominantly on its own rear side, so that the degree of overlap is almost complete, similar to the usual administration form as an adhesive tape roll, where the adhesive is also glued to its own rear side. When flagging, static forces act, for example due to the flexural rigidity of the carrier and the winding tension, which can lead to the open ends of the adhesive tape standing up in an undesirable manner, similar to the start of automatic unwinding. The flagging resistance is therefore the ability of the adhesive to withstand this static force.

Flagging - in the case of an adhesive tape wrapped around a body - is understood to mean the tendency of one end of the adhesive tape to protrude. The cause arises from the combination of the holding force of the adhesive, the rigidity of the carrier and the diameter of the cable set.

The flagging resistance of wire harnessing (WH) cable wrapping tapes is demonstrated using the TFT (Threshold Flagging Time) method. A limit value of well over 1000 min TFT, preferably over 2000 min TFT, is defined as the target value for a perfectly flag-free fabric product.
An alternative method is the SWAT method, as explained below.

The adhesive tape is intended to protect the cables against damage caused by abrasion, for example on sharp edges. Therefore, in particular, correspondingly robust carrier materials are used. The adhesive tapes are therefore classified in abrasion classes A to E according to LV 312.

The cable insulation must not become brittle over a long period of time due to the influence of the adhesive tape in combination with increased temperature. According to LV 312, a distinction is made between four temperature classes T1 to T4, corresponding to 80 ° C (also called temperature class A), 105 ° C (also called temperature class B (105)), 125 ° C (also called temperature class C) ) and 150 ° C (also called temperature class D), which the wrapped cables must withstand for over 3000 hours without becoming brittle. It goes without saying that temperature classes T3 and T4 place higher demands on the adhesive tape than the lower classes T1 and T2. The classification T1 to T4 is determined by the cable insulation material as well as the pressure-sensitive adhesive and the carrier type.

Cable winding tapes with pressure-sensitive adhesives based on natural rubber mostly show good anti-sagging resistance, but have an unwinding force that increases over the storage time, and above all with increasing temperatures. In addition, they only meet the lower temperature classes for cable compatibility.

Adhesive tapes based on synthetic rubbers (styrene block copolymers) and SBS / SIS behave in a similar way. Even the hydrogenated types are limited in temperature class.

There are also cable wrapping tapes with pressure-sensitive adhesives based on UV-crosslinkable polyacrylic acid esters. These meet the high temperature classes, but tend to flag down.

The realization of easily unrollable adhesive tapes (for cable bandaging) while maintaining good adhesive properties at the same time represents a great challenge because both properties seem to be mutually exclusive, because the essential criteria for single-sided adhesive cable wrapping tapes, adapted unwinding force and sufficiently high adhesive force, are in stark contrast to each other. While a good flow and anchoring behavior of the pressure-sensitive adhesive is a prerequisite for good bond strength values and an associated low flagging potential, these criteria tend to be a hindrance to pleasant unwind behavior.

In the case of adhesive tapes made from textile fabric backing, there is a risk that individual threads, primarily the warp threads, will tear out of the adhesive tape - this is known as fraying. Since the adhesive tape for transport is usually wound up on individual rolls with a certain width completely overlapping, it must first be unwound for processing before it can be applied to the cable. During this unwinding, the risk that individual warp threads will tear is greatest. The tearing of the threads makes processing more difficult and can weaken the stability of the carrier and thus of the adhesive tape. Therefore, if a tear occurs, the torn threads must first be cut off before the unrolled adhesive tape and the rest of the adhesive tape roll can be used further. This prevents quick and effective processing.

Fraying is caused when the force acting on individual threads is higher than that which ensures that the threads and thus the fabric carrier are held together. The cohesion of the threads of a fabric adhesive tape and thus the fraying resistance are defined by the type of fabric (raw materials, production method, equipment) and the nature of the adhesive compound applied.

The fraying resistance is quantified by measuring the force required to pull a defined amount of warp threads out of the backing of the coated adhesive tape.

A limit value of 1,400 mN is defined as the target value for a perfect and therefore good product.

The present invention is based on the object of providing an adhesive tape which, despite being easy to unwind, has good anti-sagging resistance and at the same time has good fraying and which enables particularly simple, inexpensive and fast sheathing of elongated items such as cable harnesses in automobiles.

This problem is solved by an adhesive tape as set out in the main claim. The subclaims relate to advantageous developments of the adhesive tape and methods for using the adhesive tape.

1. (a) 70,0 bis 90,0 Gew.-% n-Butylacrylat und/oder 2-Ethylhexylacrylat
2. (b) 10,0 bis 20,0 Gew.-% ein oder mehrere ethylenisch ungesättigte Monomeren, wobei mindestens 50,0 Gew.-% der ethylenisch ungesättigten Monomeren (Monomer (b)) Methylmethacrylat umfassen
3. (c) 0 bis 10,0 Gew.-% ein weiteres von Monomer (b) verschiedenes ethylenisch ungesättigtes Monomer
4. (d) 0 bis 5,0 Gew.-% ein ethylenisch ungesättigtes Monomer mit einer Säure- oder Säureanhydridfunktion

Accordingly, the invention relates to an adhesive tape, in particular for wrapping cables, made from a preferably textile carrier and from a pressure-sensitive adhesive applied to at least one side of the carrier in the form of a dried and crosslinker-free polymer dispersion, the polymer being composed of:

1. (a) 70.0 to 90.0% by weight of n-butyl acrylate and / or 2-ethylhexyl acrylate
2. (b) 10.0 to 20.0% by weight of one or more ethylenically unsaturated monomers, with at least 50.0% by weight of the ethylenically unsaturated monomers (monomer (b)) comprising methyl methacrylate
3. (c) 0 to 10.0% by weight of another ethylenically unsaturated monomer other than monomer (b)
4. (d) 0 to 5.0% by weight of an ethylenically unsaturated monomer having an acid or acid anhydride function

According to the invention, the pressure-sensitive adhesive contains between 5 and 20 parts by weight of tackifier (based on the mass of the dried polymer dispersion), the tackifier having a softening point above 90 ° C. according to ASTM E28-99 (2009).

Preferably, n-butyl acrylate and 2-ethylhexyl acrylate are used simultaneously, preferably in a ratio of 2: 1 to 1: 2, more preferably in a ratio of 1.25: 1 to 1: 1.25, particularly preferably in a ratio from 1: 1.

According to a preferred embodiment of the invention, crosslinkers, that is to say compounds capable of crosslinking, are added to the PSA.
As used here, the term crosslinker stands for chemical compounds that are able to connect molecular chains with one another so that three-dimensional crosslinked structures can be formed from the two-dimensional structures by forming intermolecular bridges.
Crosslinkers are those - especially bifunctional or polyfunctional, mostly low molecular weight - compounds which, under the selected crosslinking conditions, can react with suitable - especially functional - groups of the polymers to be crosslinked, thus linking two or more polymers or polymer sites with one another ("bridging") and thus creating a network from the polymer to be crosslinked or the polymers to be crosslinked. This usually results in an increase in cohesion.

Typical examples of crosslinkers are chemical compounds which have two or more identical or different functional groups within the molecule or at the two ends of the molecule and consequently can crosslink molecules of the same or different structures with one another. In addition, a crosslinker can react with the reactive monomer or reactive resin, as defined above, without polymerization in the actual sense of the word. In contrast to the activator, as described above, a crosslinker can be incorporated into the polymer network.

In addition to the acrylate polymers listed, in addition to any residual monomers present, additives such as light stabilizers or anti-aging agents can also be added to the PSA in the amounts stated below.

In particular, the pressure-sensitive adhesive does not contain any further polymers such as elastomers, that is to say the polymers of the pressure-sensitive adhesive consist only of monomers (a) to (b) or (a) to (d) in the stated proportions.

As monomer (b) and monomer (c) are advantageously alkyl (meth) acrylates, preferably C ₁ - to C ₂₀ -alkyl (meth) acrylates, with the exception of the monomers forming (a), aromatic vinyl monomers such as styrene and α-methylstyrene and vinyl toluene, C ₁ - to C ₁₀ -hydroxyalkyl (meth) acrylates such as in particular hydroxyethyl or hydroxypropyl (meth) acrylate, vinyl esters from carboxylic acids containing up to 20 carbon atoms such as vinyl acetate or vinyl laurate, vinyl ethers from alcohols containing up to 10 carbon atoms such as vinyl methyl ether or Vinyl isobutyl ether, vinyl halides such as vinyl chloride or vinylidene dichloride, acid amides such as acrylamide or methacrylamide and unsaturated hydrocarbons with 2 to 8 carbon atoms such as ethylene, propene, butadiene, isoprene, 1-hexene or 1-octene.

Ethyl acrylate is particularly preferred according to the invention.

At least 50.0% by weight of the ethylenically unsaturated monomers (monomer (b) and optionally monomer (c)) are methyl methacrylate, preferably at least 70.0% by weight, more preferably at least 75.0% by weight, particularly preferably 100 wt%.

wobei R³ = H oder CH₃ ist, bevorzugt wird gegebenenfalls die Mischung aus Acrylsäure oder Methacrylsäure verwendet. Besonders bevorzugt ist Acrylsäure.Examples of suitable monomers (d) are acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and / or maleic anhydride.
(Meth) acrylic acid of the formula I is preferred,

where R ³ = H or CH ₃ , the mixture of acrylic acid or methacrylic acid is preferably used, if appropriate. Acrylic acid is particularly preferred.

1. (a) 77,5 bis 82,5 Gew.-%, vorzugsweise 79,5 bis 80,5 Gew.-% n-Butylacrylat und 2-Ethylhexylacrylat, wobei n-Butylacrylat und 2-Ethylhexylacrylat in einem Verhältnis von 2:1 bis 1:2, vorzugsweise von 1,25:1 bis 1:1,25 eingesetzt sind,
2. (b) 5,0 bis 15,0 Gew.-%, vorzugsweise 8,0 bis 12,0 Gew.-% Methylmethacrylat
3. (c) 4,0 bis 12,0 Gew.-%, vorzugsweise 5,0 Gew.-% bis 9,0 Gew.-% von insbesondere Vinylester
4. (d) 0,5 bis 3,5 Gew.-%, vorzugsweise 1,0 Gew.-% bis 3,0 Gew.-% ein ethylenisch ungesättigtes Monomer mit einer Säure- oder Säureanhydridfunktion

According to a particularly preferred variant, the polymer has the following composition:

1. (a) 77.5 to 82.5% by weight, preferably 79.5 to 80.5% by weight, of n-butyl acrylate and 2-ethylhexyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate in a ratio of 2: 1 up to 1: 2, preferably from 1.25: 1 to 1: 1.25 are used,
2. (b) 5.0 to 15.0% by weight, preferably 8.0 to 12.0% by weight, methyl methacrylate
3. (c) 4.0 to 12.0% by weight, preferably 5.0% to 9.0% by weight of, in particular, vinyl ester
4. (d) 0.5 to 3.5 wt%, preferably 1.0 wt% to 3.0 wt%, of an ethylenically unsaturated monomer having an acid or acid anhydride function

Monomer (c) can also be selected from the group consisting of vinyl esters from carboxylic acids containing up to 20 carbon atoms, such as vinyl acetate or vinyl laurate, or vinyl ethers from alcohols containing up to 10 carbon atoms, such as vinyl methyl ether or vinyl isobutyl ether.

The polymer dispersion is produced by the process of emulsion polymerization of the components mentioned. Descriptions of this process can be found, for example, in "Emulsion Polymerization and Emulsion Polymers" by Peter A. Lovell and Mohamed S. EI-Aasser - Wiley-VCH 1997 - ISBN 0-471-96746-7 or in EP 1 378 527 B1 .

During the polymerization, it cannot be ruled out that not all monomers are converted into polymers. It is obvious that the residual monomer content should be as small as possible.
Adhesives comprising the polymer dispersion with a residual monomer content of less than or equal to 1% by weight, in particular less than or equal to 0.5% by weight (based on the mass of the dried polymer dispersion) are preferably provided.

The adhesive is a pressure-sensitive adhesive, that is to say an adhesive which allows a permanent bond to almost all substrates even under relatively light pressure and can be removed again from the substrate after use essentially without leaving any residue. A pressure-sensitive adhesive has a permanent pressure-sensitive adhesive effect at room temperature, that is to say has a sufficiently low viscosity and high tack, so that it wets the surface of the respective adhesive base even with slight pressure. The bondability of the adhesive is based on its adhesive properties and the redetachability on its cohesive properties.

To achieve pressure-sensitive adhesive properties, the adhesive must be above its glass transition temperature at the processing temperature in order to have viscoelastic properties. Since the cable harness is wound at normal ambient temperature (approximately between 15 ° C and 25 ° C), the glass transition temperature of the PSA formulation is preferably below +15 ° C (determined with DSC (Differential Scanning Calorimetry) in accordance with DIN 53 765 at a heating rate of 10 K. / min).

The glass transition temperature of the acrylate copolymers can be estimated according to the Fox equation from the glass transition temperatures of the homopolymers and their relative proportions).

In order to achieve polymers, for example pressure-sensitive adhesives or heat-sealing compounds, with the desired glass transition temperatures, the quantitative composition of the monomer mixture advantageously chosen such that according to an equation (G1) in analogy to the Fox equation (cf. TG Fox, Bull. Am. Phys. Soc. 1956, 1, 123 ) gives the desired T _G value for the polymer. $$\frac{1}{{\text{T}}_{\text{G}}}={\displaystyle \sum _{\text{n}}\frac{{\text{W.}}_{\text{n}}}{{\text{T}}_{\text{G}\text{, n}}}}$$

The possible addition of tackifiers inevitably increases the glass transition temperature, depending on the amount added, compatibility and softening temperature by approx. 5 to 40 K.

Acrylate copolymers with a glass transition temperature of at most 0 ° C. are therefore preferred.

According to ASTM D3330, the polymers according to the invention have a bond strength to steel of at least 1.0 N / cm (with a basis weight of the adhesive of 30 g / m ² on a 23 μm polyester film as a carrier).

According to the general understanding of the skilled person, an “adhesive resin” is understood to mean an oligomeric or polymeric resin which increases the autoadhesion (the tack, the inherent tack) of the PSA in comparison to the PSA which does not contain adhesive resin but is otherwise identical.

The use of tackifiers to increase the bond strengths of PSAs is known in principle. This effect also occurs when between 3 and 20 parts by weight (corresponds to 20 parts by weight), or preferably 5 to 15 parts by weight of tackifier (based on the mass of the dried polymer dispersion) are added to the adhesive. Preference is also given to adding 5 to 12, more preferably 6 to 10 parts by weight of tackifier (based on the mass of the dried polymer dispersion).

Adhesive resins with a softening point above 100 ° C. according to ASTM E28-99 (2009) are preferred.

In principle, all known classes of substances are suitable as tackifiers, also known as tackifier resins. Tackifiers are, for example, hydrocarbon resins (for example polymers based on unsaturated C ₅ or C ₉ monomers), terpene phenol resins, polyterpene resins based on raw materials such as, for example, α- or ß-pinene, aromatic resins such as coumarone-indene resins or resins based Styrene or α-methylstyrene such as rosin and its derivatives, for example disproportionated, dimerized or esterified rosin, for example reaction products with glycol, glycerol or pentaerythritol, to name just a few. Preference is given to resins without easily oxidizable double bonds, such as terpene phenol resins, aromatic resins and particularly preferably resins which are produced by hydrogenation, such as, for example, hydrogenated aromatic resins, hydrogenated polycyclopentadiene resins, hydrogenated rosin derivatives or hydrogenated polyterpene resins.

Resins based on terpene phenols and colophony esters are preferred.

Resins based on terpene phenols and colophony esters with a softening point above 100 ° C. according to ASTM E28-99 (2009) are particularly preferred. The resins are expediently used in dispersion form. In this way, they can be mixed with the finely divided polymer dispersion without any problems.

To further improve the cable compatibility, the adhesive formulation can optionally be mixed with light stabilizers or primary and / or secondary aging inhibitors.

Products based on sterically hindered phenols, phosphites, thiosynergists, sterically hindered amines or UV absorbers can be used as anti-aging agents.

Primary antioxidants such as Irganox 1010 or Irganox 254, alone or in combination with secondary antioxidants such as Irgafos TNPP or Irgafos 168, are preferably used.

The anti-aging agents can be used in any combination with one another, mixtures of primary and secondary antioxidants in combination with light stabilizers such as, for example, Tinuvin 213 showing particularly good anti-aging effects.

Anti-aging agents in which a primary antioxidant is combined in one molecule with a secondary antioxidant have proven particularly advantageous. These anti-aging agents are cresol derivatives whose aromatic ring is substituted with thioalkyl chains at any two different positions, preferably in ortho and meta positions to the OH group, the sulfur atom also being one or more alkyl chains on the aromatic ring of the cresol unit can be connected. The number of carbon atoms between the aromatic and the sulfur atom can be between 1 and 10, preferably between 1 and 4. The number of carbon atoms in the alkyl side chain can be between 1 and 25, preferably between 6 and 16. Particularly preferred here are compounds of the 4,6-bis (dodecylthiomethyl) -o-cresol, 4,6-bis (undecylthiomethyl) -o-cresol, 4,6-bis (decylthiomethyl) -o-cresol, 4,6-bis type (nonylthiomethyl) -o-cresol or 4,6-bis (octylthiomethyl) -o-cresol. Such anti-aging agents are offered, for example, by the company Ciba Geigy under the name Irganox 1726 or Irganox 1520.

The amount of anti-aging agent or anti-aging agent package added should be in a range between 0.1 and 10 parts by weight based on the mass of the dried polymer dispersion, preferably in a range between 0.2 and 5 parts by weight based on the mass of the dried polymer dispersion, particularly preferably in one range between 0.5 and 3 parts by weight based on the mass of the dried polymer dispersion.

The dosage form in the form of a dispersion for particularly simple miscibility with the adhesive dispersion is preferred. Alternatively, liquid anti-aging agents can also be incorporated directly into the dispersion, the incorporation step should be followed by a standing time of a few hours in order to enable homogeneous distribution in the dispersion or the absorption of the anti-aging agent into the dispersion particles. Another alternative is to add an organic solution of the anti-aging agents to the dispersion.

Suitable concentrations are in the range from 0.1 to 8, preferably 01 to 5, parts by weight based on the mass of the dried polymer dispersion.

To improve the processing properties, the adhesive formulation can also be mixed with customary processing aids, such as rheology additives (thickeners), defoamers, deaerators, wetting agents or leveling agents. Suitable concentrations are in the range from 0.1 to 5 parts by weight based on the mass of the dried polymer dispersion.

A basic distinction is made between organic and inorganic rheological additives.

The organic thickeners, in turn, are split into two main active principles: (i) the thickening of the aqueous phase, i.e. non-associative, and (ii) the formation of associations between the thickener molecule and particles, partly with the inclusion of stabilizers (emulsifiers). Representatives of the first (i) group of substances are water-soluble polyacrylic acids and polycoacrylic acids, which form polyelectrolytes with a large hydrodynamic volume in a basic medium. Those skilled in the art also refer to this for short as ASE (alkali swellable emulsion). They are characterized by high resting shear viscosities and strong shear thinning. Another class of substances are the modified polysaccharides, particularly cellulose ethers such as carboxymethyl cellulose, 2-hydroxyethyl cellulose, carboxymethyl-2-hydroxyethyl cellulose, methyl cellulose, 2-hydroxyethylmethyl cellulose, 2-hydroxyethylethyl cellulose, 2-hydroxypropyl cellulose, 2-hydroxypropylmethyl cellulose, 2-hydroxybutylmethyl cellulose. This class of substances also includes less common polysaccharides such as starch derivatives and special polyethers.

The active group of (ii) associative thickeners are in principle block copolymers with a water-soluble central block and hydrophobic end blocks, the end blocks interacting with the particles or themselves and thereby forming a spatial network including the particles. Typical representatives are known to the person skilled in the art as HASE (hydrophobically modified alkali swellable emulsion), HEUR (hydrophobically modified ethylene oxide urethane) or HMHEC (hydrophobically modified hydroxyethyl cellulose). In the HASE thickeners, the middle block is an ASE, the end blocks are mostly long, hydrophobic alkyl chains coupled via polyethylene oxide bridges. In the HEUR, the water-soluble central block is a polyurethane, in the HMHEC a 2-hydroxyethyl cellulose. The non-ionic HEUR and HMHEC in particular are largely pH insensitive.

Depending on the structure, the associative thickeners produce more or less a Newtonian (shear rate-independent) or pseudoplastic (shear-thickening) flow behavior. Sometimes they also show a thixotropic character, that is, in addition to a shear force dependence of the viscosity, they also show a time dependency.

The inorganic thickeners are mostly sheet silicates of natural or synthetic origin, examples are hectorites and smectites. In contact with water, the individual layers separate from one another. Due to different charges on the surfaces and edges of the platelets, they form a space-filling house of cards structure at rest, which results in high rest shear viscosities up to flow limits. When sheared, the house of cards structure collapses and a clear drop in shear viscosity can be observed. Depending on the charge, concentration and geometric dimensions of the platelets, the structure build-up can take some time, so that thixotropy can also be achieved with such inorganic thickeners.

Some of the thickeners can be stirred directly into the adhesive dispersion or, in some cases, are advantageously prediluted or predispersed in water beforehand.

Suppliers of thickeners are, for example, OMG Borchers, Omya, Byk Chemie, Dow Chemical Company, Evonik, Rockwood and Münzing Chemie.

Fillers (reinforcing or non-reinforcing) such as silicon dioxides (spherical, needle-shaped, platelet-shaped or irregular like pyrogenic silicas), glass as solid or hollow spheres, microballoons, calcium carbonates, zinc oxides, titanium dioxide, aluminum oxides or aluminum oxide hydroxides can be used to adjust the processability as well as Adhesive properties are used. Suitable concentrations are in the range from 0.1 to 20 parts by weight based on the mass of the dried polymer dispersion.

In a preferred embodiment, the adhesive formulation of the invention according to ASTM D3330 has a bond strength to steel of at least 2.0 N / cm (with a basis weight of the adhesive of approx. 100 g / m ² on polyester fabric as a carrier according to the example).

In principle, all carrier materials are suitable as carriers; textile carriers are preferred and fabrics, in particular polyester fabrics, are particularly preferred.

All known textile carriers such as knitted fabrics, scrims, tapes, braids, needle-punched textiles, felts, woven fabrics (including plain weave, twill and satin weave), knitted fabrics (including warp-knitted fabrics and knitted fabrics) or non-woven fabrics can be used as carrier material for the adhesive tape, whereby under "non-woven “At least textile fabrics according to EN 29092 (1988) as well as stitchbonded nonwovens and similar systems are to be understood.

An adhesive tape in which a woven fabric, a fleece or a knitted fabric is used as the carrier is particularly advantageous. Such carriers are for example in the WO 2015/004190 A1 described.

Spacer fabrics and knitted fabrics with lamination can also be used. Such spacer fabrics are in the EP 0 071 212 B1 disclosed. Spacer fabrics are mat-shaped laminated bodies with a cover layer made of a fiber or filament fleece, an underlayer and individual or tufts of retaining fibers between these layers, which are needled over the surface of the laminate through the particle layer and connect the cover layer and the underlayer to one another. As an additional, but not required, feature, according to EP 0 071 212 B1 in the holding fibers particles of inert rock, such as sand, gravel or the like, are present.

The holding fibers needled through the particle layer hold the top layer and the backing layer at a distance from one another and they are connected to the top layer and the backing layer.

Particularly consolidated staple fiber nonwovens, but also filament, meltblown and spun nonwovens, which usually need to be additionally consolidated, are suitable as nonwovens. Mechanical, thermal and chemical consolidation are known as possible consolidation methods for nonwovens. If the fibers are held together purely mechanically in the case of mechanical consolidation, mostly by swirling the individual fibers, by meshing fiber bundles or by sewing in additional threads, then adhesive (with binder) or cohesive (binder-free) fiber-fiber can be achieved through thermal and chemical processes. Achieve ties. With suitable formulation and process management, these can be limited exclusively or at least predominantly to fiber nodes, so that a stable, three-dimensional network is nevertheless formed while maintaining the loose, open structure in the fleece.

Nonwovens have proven to be particularly advantageous which are strengthened, in particular, by stitching over with separate threads or by meshing.

Such consolidated nonwovens are produced, for example, on stitchbonding machines of the “Malimo” type from Karl Mayer, formerly Malimo, and can be obtained from Techtex GmbH, among others. A Malivlies is characterized in that a transverse fiber fleece is consolidated by the formation of meshes from fibers of the fleece. A fleece of the Kunit or Multiknit type can also be used as a carrier. A Kunit fleece is characterized in that it arises from the processing of a longitudinally oriented fiber fleece into a flat structure that has meshes on one side and mesh webs or pile fiber folds on the other, but has neither threads nor prefabricated flat structures. Such a fleece has also been produced for a long time on stitchbonding machines of the “Malimo” type from Karl Mayer. Another characteristic feature of this fleece is that, as a longitudinal fiber fleece, it can absorb high tensile forces in the longitudinal direction. A multiknit fleece is characterized in comparison to the Kunit fleece in that the fleece is solidified by piercing with needles on both sides, both on the top and on the underside. The starting product for a Multiknit is usually one or two single-sided meshed pile fiber nonwoven fabrics manufactured using the Kunit process. In the end product, both nonwoven tops are formed into a closed surface by intermingling fibers and are connected to one another by almost vertical fibers. The additional possibility of introducing further pierceable flat structures and / or spreadable media is given. Finally, stitched nonwovens are also suitable as a preliminary product for forming a covering according to the invention and an adhesive tape according to the invention. A stitched fleece is formed from a fleece material with a large number of seams running parallel to one another. These seams are created by sewing in or stitching continuous textile threads. For this type of fleece, stitchbonding machines of the “Malimo” type from Karl Mayer are known.

Needle fleeces are also particularly suitable. In needle-punched nonwoven, a fiber pile is made into a flat structure with the aid of barbed needles. By alternately piercing and withdrawing the needles, the material is solidified on a needle bar, whereby the individual fibers intertwine to form a solid sheet. The number and design of the needling points (needle shape, penetration depth, needling on both sides) determine the strength and strength of the fiber structures, which are usually light, air-permeable and elastic.

A staple fiber fleece that is pre-consolidated by mechanical processing in the first step or that is a wet fleece that was laid hydrodynamically, with between 2% and 50% by weight of the fibers of the fleece being melt fibers, in particular between 5% by weight, is also particularly advantageous Wt .-% and 40 wt .-% of the fibers of the nonwoven.

A fleece of this type is characterized in that the fibers are laid wet or, for example, a staple fiber fleece is pre-consolidated through the formation of stitches from fibers of the fleece by needling, sewing, air and / or water jet processing. In a second step, the heat setting takes place, whereby the strength of the fleece is increased again by the melting or melting of the melt fibers.

For the use according to the invention of nonwovens, the adhesive consolidation of mechanically pre-consolidated or wet-laid nonwovens is of particular interest, it being possible for this to take place in solid, liquid, foamed or pasty form via the addition of binders. A variety of basic forms of administration are possible, for example solid binders as a powder for trickling in, as a film or as a grid or in the form of binding fibers. Liquid binders are dissolved in water or organic solvents or can be applied as a dispersion. Binding dispersions are predominantly chosen for adhesive bonding: thermosets in the form of phenolic or melamine resin dispersions, elastomers as dispersions of natural or synthetic rubbers or mostly dispersions of thermoplastics such as acrylates, vinyl acetates, polyurethanes, styrene-butadiene systems, PVC and the like. and their copolymers. Usually, these are anionic or non-ionically stabilized dispersions, but in special cases cationic dispersions can also be advantageous.

The type of binding agent can be applied according to the state of the art and can be found, for example, in standard works on coating or non-woven technology such as "Nonwovens" (Georg Thieme Verlag, Stuttgart, 1982) or "Textiltechnik-Vliesstofferzeugung" (employers' group Gesamttextil, Eschborn, 1996).

For mechanically pre-bonded nonwovens that already have sufficient bond strength, the one-sided spray application of a binding agent is recommended in order to change surface properties in a targeted manner.

In addition to the economical use of the binding agent, this type of procedure also significantly reduces the energy required for drying. Since no squeegee rollers are required and the dispersions remain predominantly in the upper area of the nonwoven, undesired hardening and stiffening of the nonwoven can be largely prevented.

For adequate adhesive bonding of the nonwoven backing, binding agents in the order of magnitude of 1% to 50%, in particular 3% to 20%, based on the weight of the fiber nonwoven, should generally be added.

The addition of the binding agent can take place during the manufacture of the nonwoven, during the mechanical pre-consolidation or in a separate process step, which can be carried out inline or off-line. After the binder has been added, a temporary state must be created for the binder in which it becomes sticky and bonds the fibers with adhesive - this can be achieved during the drying of dispersions, for example, but also by heating, with further possibilities for variation through the application of surface or partial pressure are. The activation of the binding agent can take place in known drying tunnels, but with a suitable selection of binding agents also by means of infrared radiation, UV radiation, ultrasound, high frequency radiation or the like. For the subsequent end use, it makes sense, but is not absolutely necessary, for the binder to have lost its tack after the end of the nonwoven manufacturing process. It is advantageous that volatile components such as fiber auxiliaries are removed by thermal treatment and thus a fleece with favorable fogging values is created, so that when a low-fogging adhesive is used, an adhesive tape with particularly favorable fogging values can be produced, and the cover also shows a very low fogging value.

Fogging (see DIN 75201 A) is understood to mean the effect that, under unfavorable conditions, low molecular weight compounds can outgas from the adhesive tapes and condense on cold parts. This can, for example, impair the view through the windshield.

Another special form of adhesive bonding is that the binding agent is activated by dissolving or swelling. In principle, the fibers themselves or mixed special fibers can also take over the function of the binding agent. However, since for most polymer fibers such solvents are questionable from an environmental point of view or problematic in their handling, this process is rarely used.

Advantageously, and at least in some areas, the carrier can have a surface that is ground smooth on one or both sides, preferably a surface that is ground smooth over the entire area. The smoothly ground surface may be chinted, for example in the EP 1 448 744 A1 will be explained in detail.

Furthermore, the carrier can be calendered for compaction in a rolling mill. The two rollers preferably run in opposite directions and at the same peripheral speed, so that the carrier is pressed and compacted.
If the circumferential speed of the rollers differs, the carrier is additionally ground smooth.

• ● die Fadenzahl in der Kette 10 bis 60/cm beträgt
• ● die Fadenzahl im Schuss 10 bis 40/cm beträgt
• ● die Kettfäden ein Garngewicht zwischen 40 und 400 dtex, insbesondere zwischen 44 und 330 dtex, besonders bevorzugt von 167 dtex besitzen
• ● die Schussfäden ein Garngewicht zwischen 40 und 660 dtex, insbesondere zwischen 44 und 400 dtex, besonders bevorzugt von 167 dtex besitzen

The carrier is preferably a fabric, more preferably a polyester fabric. Particularly preferred fabrics are constructed as follows:

• ● the number of threads in the warp is 10 to 60 / cm
• ● the thread count in the weft is 10 to 40 / cm
• ● the warp threads have a yarn weight between 40 and 400 dtex, in particular between 44 and 330 dtex, particularly preferably 167 dtex
• ● the weft threads have a yarn weight between 40 and 660 dtex, in particular between 44 and 400 dtex, particularly preferably 167 dtex

According to a further advantageous embodiment of the invention, the number of threads in the warp is 40 to 50 / cm, preferably 44 / cm.
According to a further advantageous embodiment of the invention, the thread count in the weft is 18 to 22 / cm, preferably 20 / cm.

According to a further advantageous embodiment of the invention, the fabric is a polyester fabric. Further possibilities are polyamide fabric, viscose fabric and / or a mixed fabric made from the materials mentioned.

More preferably, the thickness of the fabric is a maximum of 300 μm, particularly preferably 170 to 230 μm, very particularly preferably 190 to 210 μm. According to a further advantageous embodiment of the invention, the carrier has a weight per unit area of up to 200 g / m ² , preferably 100 to 150 g / m ² .

The starting materials for the carrier material for the adhesive tape are in particular (chemical) fibers (staple fiber or continuous filament) made of synthetic polymers, also called synthetic fibers, made of polyester, polyamide, polyimide, aramid, polyolefin, polyacrylonitrile or glass, and (chemical) fibers made of natural polymers such as cellulosic fibers (viscose, modal, lyocell, cupro, acetate, triacetate, cellulon), such as rubber fibers, such as vegetable protein fibers and / or such as animal protein fibers and / or natural fibers made of cotton, sisal, flax, silk, hemp, linen, coconut or wool intended. However, the present invention is not restricted to the materials mentioned, but rather a large number of other fibers can be used to produce the carrier, which is evident to the person skilled in the art without having to be inventive. Furthermore, yarns made from the specified fibers are also suitable.

In the case of woven or non-woven fabrics, individual threads can be made from a mixed yarn, i.e. they can have synthetic and natural components. As a rule, however, the warp threads and the weft threads are each made of one type. The warp threads and / or the weft threads can each consist only of synthetic threads or only of threads made from natural raw materials, that is to say they can be of one type.

The yarns or threads of the fabric can be present as filaments. In the context of this invention, a filament is understood to mean a bundle of parallel, straight individual fibers / individual filaments, also often referred to as multifilament in the literature. If necessary, this fiber bundle can be solidified by twisting, in which case we speak of spun or twisted filaments. Alternatively, the fiber bundle can be solidified by swirling with compressed air or a water jet. In the following, only the term filament is used in general for all these embodiments. The filament can be textured or smooth and point consolidated or unconsolidated.

Polyester is preferably used as the material for the textile carrier, due to its excellent aging resistance and excellent media resistance to chemicals and operating media such as oil, gasoline, antifreeze, etc. In addition, polyester has the advantage that it leads to a very abrasion-resistant and temperature-resistant carrier, which is of particular importance for the special purpose of bundling cables in automobiles and, for example, in the engine compartment. According to one embodiment of the invention, a PET fleece or a PET fabric is used as the carrier.

The weight per unit area of the textile carrier is advantageously between 30 g / m ² and 300 g / m ^2, more advantageously between 50 g / m ² and 200 g / m ² , particularly advantageously between 50 g / m ² and 150 g / m ² , entirely particularly advantageously between 70 g / m ² and 130 g / m ² .

According to a preferred embodiment of the invention, more than 10%, preferably more than 25%, more preferably more than 50% of the adhesive has sunk into the carrier after application to the carrier. A numerical value of, for example, 25% means that the adhesive has penetrated over a layer thickness of 25% of the thickness of the textile carrier, i.e. in the case of a carrier with a thickness of 100 μm over a layer thickness of 25 μm within the carrier, starting from the surface of the carrier on which the adhesive is coated, and in a direction perpendicular to the plane spanned by the longitudinal or transverse direction.

A carrier material is also suitable for the adhesive tape, which consists of paper, a laminate, a film (for example PP, PE, PET, PA, PU), foam or a foamed film.

These non-textile flat materials are particularly suitable when special requirements require such a modification of the invention. Foils, for example, are usually thinner than textiles and, thanks to their closed layer, offer additional protection against the ingress of chemicals and operating media such as oil, petrol, antifreeze, etc. in the actual cable area and can be largely adapted to the requirements through a suitable selection of the material: with polyurethanes, copolymers made of polyolefins, for example, flexible and elastic sheaths can be produced, with polyester and polyamides good abrasion and temperature resistance is achieved.

Foams or foamed foils, on the other hand, have the property of greater space filling and good noise damping - if a cable harness is, for example, in a channel or tunnel-like This area in the vehicle can be prevented from the outset with a wrapping tape that is suitable in terms of thickness and damping.

A laminate composed of the textile carrier and a film or plastic layer applied to at least one side of the textile carrier is preferred. Furthermore, films or plastic layers can be applied to the top and bottom of the textile carrier. It can be applied by lamination or by extrusion. A variant is preferred in which the textile carrier is provided on the underside with a film which is equipped on the other side with a pressure-sensitive adhesive.

Films such as PP, PE, polyester, PA, PU or PVC are suitable as film or plastic material. The films themselves can in turn consist of several individual layers, for example layers coextruded to form a film.

Polyolefins are preferred, but copolymers of ethylene and polar monomers such as styrene, vinyl acetate, methyl methacrylate, butyl acrylate or acrylic acid are also included. It can be a homopolymer such as HDPE, LDPE, MDPE or a copolymer of ethylene with another olefin such as propene, butene, hexene or octene (for example LLDPE, VLLDE). Polypropylenes are also suitable (for example polypropylene homopolymers, polypropylene random copolymers or polypropylene block copolymers).

The film preferably has a thickness of 12 μm to 100 μm, more preferably 28 to 50 μm, in particular 35 μm. The film can be colored and / or transparent.

Finally, the adhesive tape can have a covering material with which the one or two layers of adhesive are covered until use. All materials listed in detail above are also suitable as covering materials.

Preference is given to using a non-linting material such as a plastic film or a well-glued, long-fiber paper.

If the described adhesive tape is to be of low flammability, this can be achieved by adding flame retardants to the carrier and / or the adhesive. These can be organic bromine compounds, if necessary with synergists such as antimony trioxide, but with regard to the halogen-free nature of the adhesive tape, red phosphorus, organophosphorus, mineral or intumescent compounds such as ammonium polyphosphate are preferably used alone or in conjunction with synergists.

The amount of adhesive applied, based on the area of the adhesive tape, is preferably between 40 and 160 g / m ² , preferably between 60 and 130 g / m ² , more preferably between 80 and 100 g / m ² .

In the context of this invention, the general expression “adhesive tape” encompasses all flat structures such as films or film sections extended in two dimensions, tapes with extended length and limited width, tape sections and the like, ultimately also diecuts or labels.
The adhesive tape thus has a longitudinal dimension and a width dimension. The adhesive tape also has a thickness running perpendicular to both dimensions, the width dimension and the longitudinal dimension being many times greater than the thickness. The thickness is as equal as possible, preferably exactly the same, over the entire surface area of the adhesive tape determined by length and width.

The adhesive tape is in particular in web form. A path is understood to mean an object whose length is many times greater than the width and the width is preferably designed to be exactly the same along the entire length. The adhesive tape can be produced in the form of a roll, that is to say rolled up on itself in the form of an Archimedean spiral.

A back varnish can be applied to the back of the adhesive tape in order to favorably influence the unwinding properties of the adhesive tape wound into an Archimedean spiral. For this purpose, this backing varnish can be equipped with silicone or fluorosilicon compounds and with polyvinyl stearyl carbamate, polyethylene imine stearyl carbamide or organofluorine compounds as adhesive substances.

The adhesive composition can be applied in the longitudinal direction of the adhesive tape in the form of a strip which has a smaller width than the carrier of the adhesive tape. Depending on the application, several parallel strips of the adhesive can also be coated on the carrier material.

The position of the strip on the carrier can be freely selected, an arrangement directly on one of the edges of the carrier being preferred.

The adhesive is preferably applied over the entire surface of the carrier.

At least one strip of covering can be provided on the adhesive coating of the carrier, which strip or which extend in the longitudinal direction of the adhesive tape and which or which cover between 20% and 90% of the adhesive coating.
The strip preferably covers a total of between 50% and 80% of the adhesive coating. The degree of coverage is selected depending on the application and the diameter of the cable set. The percentages given relate to the width of the strips of the roofing in relation to the width of the beam.

According to a preferred embodiment of the invention, there is exactly one strip of the covering on the adhesive coating.

The position of the strip on the adhesive coating can be freely selected, an arrangement directly on one of the longitudinal edges of the carrier being preferred. This results in an adhesive strip which extends in the longitudinal direction of the adhesive tape and is flush with the other longitudinal edge of the carrier. If the adhesive tape is used to encase a cable harness by guiding the adhesive tape around the cable harness in a helical movement, the cable harness can be encased in such a way that the adhesive mass of the adhesive tape is only stuck to the adhesive tape itself, while the goods are not covered with any adhesive Touch comes.

The cable harness sheathed in this way has a very high degree of flexibility because the cables are not fixed by any adhesive. This significantly increases its flexibility during installation - especially in narrow passages or sharp bends.

If a certain fixing of the adhesive tape on the item is desired, the sheathing can take place in such a way that part of the adhesive strip is glued to the adhesive tape itself and another part to the item.

According to another advantageous embodiment, the strip is applied in the middle of the adhesive coating, so that two adhesive strips are produced on the longitudinal edges of the carrier in the longitudinal direction of the adhesive tape.

For the safe and economical application of the adhesive tape in said helical movement around the cable harness and to prevent the resulting protective cover from slipping, the two adhesive strips present on the longitudinal edges of the adhesive tape are advantageous, especially if one that is usually narrower than the second strip is advantageous Fixation aid is used and the second, wider strip serves as a closure. In this way, the adhesive tape is glued to the cable in such a way that the cable set is secured against slipping and is nevertheless designed to be flexible.

In addition, there are embodiments in which more than one strip of the covering is applied to the adhesive coating. If only one strip is mentioned, the person skilled in the art reads in his mind that several strips can also cover the adhesive coating at the same time.

The production process for the adhesive tape of the invention is limited to coating the carrier directly with the dispersion in one or more work steps carried out in succession. In the case of textile carriers, the untreated textile can be coated directly or using the transfer process. Alternatively, the textile can be pretreated with a coating (with any film-forming substance from solution, dispersion, melt and / or radiation-curing) in order then to be provided with the pressure-sensitive adhesive in a subsequent work step directly or in a transfer process.

The usual application units are used: wire doctor blade, coating bar, roller application, nozzle coating, double chamber doctor blade, multiple cascade nozzle.

Due to the positive properties outlined, the adhesive tape can be used excellently for insulating and winding wires or cables.

Furthermore, it is advantageously suitable for sheathing elongated goods such as cable sets in motor vehicles, in which the adhesive tape can be guided in a helical line around the elongated goods or the elongated goods can be enveloped by the tape in the axial direction.

Finally, the concept of the invention also includes an elongated item, encased with an adhesive tape according to the invention. The elongate good is preferably a cable set.

Due to the excellent suitability of the adhesive tape, it can be used in a sheathing that consists of a covering in which the self-adhesive tape is present at least in one edge area of the covering, which is bonded to the covering in such a way that the adhesive tape is over one of the Extends the longitudinal edges of the covering, preferably in an edge area that is narrow compared to the width of the covering.

Such a product and optimized embodiments thereof are described in the EP 1 312 097 A1 disclosed. In the EP 1 300 452 A2 , the DE 102 29 527 A1 as well as the WO 2006 108 871 A1 further developments are presented for which the adhesive tape according to the invention is also very well suited. The adhesive tape according to the invention can also be used in a method such as that shown in FIG EP 1 367 608 A2 disclosed.

Finally describe the EP 1 315 781 A1 as well as the DE 103 29 994 A1 Embodiments of adhesive tapes such as are also possible for the adhesive tape of the invention.

More preferably, the adhesive tape does not destroy the same when bonded to cables with PVC sheathing and to cables with polyolefin sheathing if a composite of cables and adhesive tape according to LV 312 is stored at temperatures above 100 ° C and up to 3000 h and then the cables be bent around a mandrel.

The adhesive tape according to the invention is ideal for wrapping cables, can be easily unwound for simple processing, shows no or only slight flagging and fraying and shows no cable embrittlement even in the high temperature classes T3 and T4 over 3000 h.

Also encompassed by the inventive concept is a sheathed elongated good, such as in particular a cable set, sheathed with an adhesive tape according to the invention, as well as a vehicle containing such a sheathed elongated good.
According to one embodiment of the invention, the elongated good is a cable harness which comprises a bundle of several cables such as 3 to 1000 cables, preferably 10 to 500 cables, in particular between 50 and 300 cables.

In the following, the adhesive tape will be explained in more detail with the aid of several figures, without wishing to create any kind of restriction.

• 1 das Klebeband im seitlichen Schnitt,
• 2 einen Ausschnitt eines Kabelbaums, der sich aus einer Bündelung von einzelnen Kabeln zusammensetzt und der mit dem erfindungsgemäße Klebeband ummantelt ist, und
• 3 eine vorteilhafte Anwendung des Klebebands.

Show it

• 1 the tape in the side cut,
• 2 a section of a cable harness which is composed of a bundle of individual cables and which is sheathed with the adhesive tape according to the invention, and
• 3 an advantageous application of the adhesive tape.

In the 1 the adhesive tape is shown in cross-section in the transverse direction (cross-section), which consists of a fabric carrier 1 to which a layer of a self-adhesive coating 2 based on an acrylate dispersion is applied on one side.

20% of the adhesive has sunk into the carrier, which results in optimal anchoring and at the same time improves the hand-tearability of the carrier.

In the 2 a section of a cable harness is shown which is composed of a bundle of individual cables 7 and which is sheathed with the adhesive tape 11 according to the invention. The tape is threaded around the wiring harness in a helical motion.

The section of the wiring harness shown shows two windings I and II of the adhesive tape. Further windings would extend to the left; these are not shown here.

In a further embodiment for a sheathing, two inventive tapes 60, 70 equipped with an adhesive are laminated to one another with their adhesives (preferably by 50% each), so that a product results as shown in FIG 3 is shown.

Examples

Sketch of the examples

The adhesive tape of the invention is described below in a preferred embodiment using an example, without thereby wishing to subject the invention to any restriction.

Furthermore, comparative examples are listed in which unsuitable adhesive tapes are shown.

• Die Haftklebstoffdispersionen wurden durch Einrühren eines Polyurethan Assoziativverdickers (Borchigel 0625, OMG Borchers) auf eine Viskosität von ca. 1000 Pa*s bei einer Schergeschwindigkeit von 0,01 s^-1 eingestellt (gemessen mit Kegel/Platte Geometrie im Rotationsmodus mit einem Rheometer DSR 200 N von Rheometric Scientific). Mit einem Filmziehgerät wurde ein Polyestergewebe (Feinheit der Faser 167 dtex, Fadenzahl Kette 43 1/cm, Fadenzahl Schuss 25 1/cm) so mit der verdickten Beispielhaftklebstoffdispersion bestrichen, dass nach dem Trocknen in einem Umluftofen bei 85 °C über 5 Minuten ein Klebmasseflächengewicht von 90 g/m² resultierte.

To illustrate the invention, example adhesive tapes were produced according to the following scheme:

• The pressure-sensitive adhesive dispersions were adjusted to a viscosity of approx. 1000 Pa * s at a shear rate of 0.01 s ^-1 by stirring in a polyurethane associative thickener (Borchigel 0625, OMG Borchers) (measured with cone / plate geometry in rotation mode with a DSR 200 rheometer N from Rheometric Scientific). Using a film applicator, a polyester fabric (fineness of the fiber 167 dtex, thread count warp 43 1 / cm, thread count weft 25 1 / cm) was coated with the thickened exemplary pressure-sensitive adhesive dispersion in such a way that, after drying in a convection oven at 85 ° C. for 5 minutes, an adhesive weight per unit area of 90 g / m ² resulted.

Assessment criteria

• ● Abflaggresistenz gemäß dem SWAT-Test
• ● Kabelverträglichkeit nach LV 312 im Hinblick auf Versprödung und Verfärbung
• ● Fraying gemäß dem unten angegeben Test

The criteria for an application-oriented adhesive tape for wrapping cables are

• ● Flag resistance according to the SWAT test
• ● Cable compatibility according to LV 312 with regard to embrittlement and discoloration
• ● Fraying according to the test given below

Carrying out the tests

Unless expressly stated otherwise, the measurements are carried out at a test climate of 23 ± 1 ° C and 50 ± 5% rel. Humidity carried out.

Measurement of flagging resistance using the SWA T method

The SWAT test is used to examine the flagging behavior of adhesive tapes after they have been wrapped in a spiral around a cable.
The test is carried out under standard climates (23 ± 1 ° C and 50 ± 5% relative humidity) and 40 ° C. The increased temperature simulates the difficult requirements during transport.

A 19 mm wide adhesive tape is used for the test. This is manually wound around a cable sheathed with ETFE (ethylene-tetrafluoroethylene) and having a diameter of 1 mm four times (1440 °) without additional pressure. The tape is cut with scissors.

It is assumed that an average of 5 mm long flag remains if the end of the adhesive tape is not pressed down.
A total of seven windings are created around the cable.

The flags are measured after three days, ten days and 30 days in a standard climate with the help of a ruler. This shows the 4th . The absolute flagging value is calculated by subtracting 5mm from the actually measured length of the flag.
In 4th the flagging value is 23 mm (28 mm - 5 mm).
The flag value given as the result is the result of the mean value of the flag value of the seven windings. The test is carried out analogously at 40 ° C. in conventional drying cabinets.

In the following, the adhesive tape of the invention is evaluated at 40 ° C. in a drying cabinet using the stated SWAT method.

A value of ≤ 10 mm applies as the lower limit for resistance to flagging.

Mean values <5 receive grade 2, mean values from 5 to 10 receive grade 1 and mean values> 10 receive grade 0.

Measurement of the cable compatibility of cables with T3 PVC insulation based on LV 312

Cables with T3 PVC insulation are not tested in LV 312. The measurement is carried out in the same way as the measurement method specified in LV 312. The measurements are made at 125 ° C (T3).

Embrittlement

A lack of embrittlement after 3000 h at 150 ° C when bending around a mandrel with a diameter of 2 mm is considered cable-compatible and is rated “2”. If the sample becomes brittle, the sample is rated “0”.

Discoloration

A lack of discoloration or the appearance of marginal discoloration after 3000 h at 150 ° C is considered to be very cable-compatible and is rated 2. Clearly visible, but not too dark discolorations can be classified as sufficiently tolerable and receive a rating of “1”. Black or dark brown discolorations are not considered cable compatible and are rated “0”.

Measurement of the bond strength

To measure the bond strength of the pure dispersions, smears of the adhesives were first prepared. For this purpose, the dispersions were placed on a PET film (polyethylene terephthalate) with a thickness of 23 μm and wiped with a film applicator so that, after drying for 5 minutes at 105 ° C. in a circulating air drying cabinet, an adhesive mass per unit area of 30 g / m ² resulted.
From this sheet, strips 20 mm wide and 25 cm long were cut out with a cutter knife.

To measure the bond strength of the formulations with resin, smears on polyester fabric were used as described above and likewise cut into strips 20 mm wide and 25 cm long with a craft knife. The bond strength on steel was measured according to ASTM D3330.

Measurement of glass transition temperatures

The glass transition temperatures were determined on the DSC 204 F1 “Phönix” dynamic differential calorimeter device from Netzsch, Germany, in 25 μl aluminum crucibles with perforated lids under a nitrogen atmosphere (20 ml / min gas flow). The sample weight was 8 ± 1 mg. The samples were measured twice from -140 ° C to 200 ° C with a heating rate of 10 K / min. The 2nd heating curve was evaluated.
The method is based on DIN 53 765.

Dynamic viscosity measurement

The viscosity measurement is carried out with a rheometer of the type DSR 200 N from Rheometric Scientific at room temperature and in the rotation mode at a shear rate of 0.01 s ^-1 with a cone-plate system with a diameter of 50 mm.

Measurement of the fraying resistance using the tear-out method

The method of tearing out warp threads is used to investigate the fraying behavior of the adhesive tapes.

A 19 mm wide adhesive tape is used for the test, a basis weight of 90 g / m ^{2 of} a pressure-sensitive adhesive being applied to a polyester fabric (48 warp threads per cm and 23 weft threads per cm, each polyester thread with a thread weight of 167 dtex). A sample with a length of 10 cm is cut from this adhesive tape. With the help of tweezers, five warp threads are loosened from the composite over a length of 3 cm at one end on one side. The released five warp threads are twisted into one another. Subsequently, for reinforcement, a rectangular cardboard with a thickness of 0.3 mm, a length of 6 cm and a width of 3 cm is glued to the side of the adhesive tape which carries the adhesive. The cardboard is positioned on the adhesive tape in such a way that the cardboard only protrudes on the long side of the adhesive tape on which no warp threads were released. The distance to the long side on which the warp threads have been released should be exactly 3 mm. The distance to the short side on which no warp threads have been released should be exactly 1 cm so that the opposite side of the cardboard is in line with the start of the released warp threads. (please refer 5 ).

The adhesive tape is then stretched in a CRE tensile testing machine (Zwick), which is equipped with 6 cm wide clamping clamps. The tensile testing machine is characterized in that the lower clamping clamp is stationary while the other moves at a constant speed during the test, and in that its load frame does not show any deflection. The cardboard that was applied to reinforce the adhesive tape is clamped into the lower clamping jaws. The previously released and twisted threads are stretched to the outer edge of the upper jaws. The distance between the two effective clamping points of the test device is exactly 1 cm before the start of the measurement. The tensile testing machine is then moved exactly 3.5 cm apart at a constant speed of 5 cm / min (see 6th ). This applies a force to the released threads. This is inserted at a right angle to the long side of the adhesive tape at the beginning of the measurement.

During the measurement, the force in millinewtons is determined that has to be applied to further sever the five warp threads. The force changes over the duration of the measurement, also due to the changing extension angle of the threads. The maximum force required (peak value) is used to compare different adhesive tapes. The pull-out value as a measure of the fraying resistance, which is given as the result, is the result of the mean value of the maximum pull-out force from measurements on five samples. From the customer's point of view, product samples rated positively, which are inconspicuous in fraying, have values of at least 1400 mN as maximum values for the pull-out force.

Composition of the example polymer dispersions

To illustrate the idea of the invention, polymer dispersions with the following comonomer composition were tested: A1 A2 B1 B2 and C D. Comparative example 1 93 0 0 3 4th Comparative example 2 51 0 0 47 2 Comparative example 3 0 98.5 0 0 1.5 Comparative example 4 0 96 0 0 4th Comparative example 5 41 41 8th 9 1 Comparative example 6 36 44 12 5 3 Comparative example 7 38 42 10 8th 2 example 1 48 40 5 5 2 Example 2 41 41 8th 9 1 Example 3 36 44 12 5 3 Example 4 38 42 10 8th 2 Comparative example 8 48 40 5 5 2 Comparative example 9 35 35 8th 18th 4th Comparative example 10 41 41 8th 9 1 A1 2-ethylhexyl acrylate A2 n-butyl acrylate B1 Methyl methacrylate B2 and C ethylenically unsaturated monomer (vinyl ester) D. Acrylic acid

These polymer dispersions were tested with different earths with the following comonomer composition Polymer content [parts by weight] Resin content [parts by weight] chemistry chemistry R&B [° C] Comparative example 1 100 30th Rosin ester Snowtack 100G 96 Comparative example 2 100 20th Rosin ester Snowtack 782G 72 Comparative example 3 100 0 x x x Comparative example 4 100 15th Rosin ester Icatack 1070 93 Comparative example 5 100 0 x x x Comparative example 6 100 2.5 Rosin ester Emultrol E185 82 Comparative example 7 100 4th Rosin ester Snowtack 110X 105 example 1 100 5 Rosin ester Aquatac 2600 98 Example 2 100 7.5 Rosin ester Snowtack 110X 105 Example 3 100 10 Terpene phenol Snowtack TP600G 100 Example 4 100 15th Terpene phenol TSR1009X50 112 Comparative example 8 100 17.5 Rosin ester Aquatac 2600 98 Comparative example 9 100 22nd Rosin ester Emultrol E185 82 Comparative example 10 100 28 Rosin ester Snowtack 100G 96

The test results are shown below: SWAT [mm] Fraying [mN] Cable compatibility Comparative example 1 2 3500 0 Comparative example 2 1 1800 0 Comparative example 3 2 1100 2 Comparative example 4 1 1300 0 Comparative example 5 0 1100 2 Comparative example 6 1 1200 2 Comparative example 7 1 1300 2 example 1 2 1450 2 Example 2 2 1500 2 Example 3 2 1600 2 Example 4 2 1700 2 Comparative example 8 1 1800 1 Comparative example 9 1 2300 0 Comparative example 10 1 3000 0 tesa® 51026 1 1600 2

All three test criteria are essential for an application-oriented adhesive tape for cable sheathing. Examples 1 to 4 show an adhesive tape which corresponds to the concept of the invention, whereas the comparative examples are unsuitable.
Even the tesa® 51026 cable bandaging tape available on the market does not meet all criteria. tesa® 51026 is a polyester fabric adhesive tape for cable winding. It consists of a polyester fabric with a weight per unit area of 125 to 135 g / m ² and an adhesive layer of 80 to 100 g / m ² . Warp and weft threads have the same yarn weight of around 167 dtex.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1848006 A2 [0003]
• DE 102013213726 A1 [0003]
• EP 2497805 A1 [0003]
• EP 1378527 B1 [0037]
• WO 2015/004190 A1 [0072]
• EP 0071212 B1 [0073]
• EP 1448744 A1 [0089]
• EP 1312097 A1 [0132]
• EP 1300452 A2 [0132]
• DE 10229527 A1 [0132]
• WO 2006108871 A1 [0132]
• EP 1367608 A2 [0132]
• EP 1315781 A1 [0133]
• DE 10329994 A1 [0133]

Non-patent literature cited

• T.G. Fox, Bull. Am. Phys. Soc. 1956, 1, 123 [0042]

Claims (15)

Adhesive tape, especially for wrapping cables, consisting of a preferably textile backing and a pressure-sensitive adhesive in the form of a dried polymer dispersion applied to at least one side of the backing, the polymer being composed of: (a) 70.0 to 90.0% by weight of n-butyl acrylate and / or 2-ethylhexyl acrylate (b) 10.0 to 20.0% by weight of one or more ethylenically unsaturated monomers, with at least 50.0% by weight of the ethylenically unsaturated monomers (monomer (b)) comprising methyl methacrylate (c) 0 to 10.0% by weight of another ethylenically unsaturated monomer other than monomer (b) (d) 0 to 5.0% by weight of an ethylenically unsaturated monomer with an acid or acid anhydride function and the pressure-sensitive adhesive contains between 3 and 20 parts by weight of tackifier (based on the weight of the dried polymer dispersion), the tackifier having a softening point above 90 ° C according to ASTM E28-99 (2009). Tape after Claim 1 , characterized in that n-butyl acrylate and 2-ethylhexyl acrylate are used in a ratio of 2: 1 to 1: 2, preferably from 1.25: 1 to 1: 1.25, more preferably in a ratio of 1: 1. Tape after one of the Claims 1 or 2 , characterized in that the tackifiers have a softening point above 100 ° C according to ASTM E28-99 (2009). Tape after at least one of the Claims 1 to 3 , characterized in that as monomer (b) and monomer (c) are alkyl (meth) acrylates, preferably C ₁ - to C ₂₀ -alkyl (meth) acrylates with the exception of the (a) forming monomers, aromatic vinyl monomers such as styrene, α -Methylstyrene and vinyl toluene, C ₁ - to C ₁₀ -hydroxyalkyl (meth) acrylates such as in particular hydroxyethyl or hydroxypropyl (meth) acrylate, vinyl esters of carboxylic acids containing up to 20 carbon atoms such as vinyl acetate or vinyl laurate, vinyl ethers of alcohols containing up to 10 carbon atoms such as Vinyl methyl ether or vinyl isobutyl ether, vinyl halides such as vinyl chloride or vinylidene dichloride, acid amides such as acrylamide or methacrylamide and unsaturated hydrocarbons with 2 to 8 carbon atoms such as ethylene, propene, butadiene, isoprene, 1-hexene or 1-octene, in particular ethyl acrylate. Adhesive tape according to at least one of the preceding claims, characterized in that acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and / or maleic anhydride are used as monomer (d). Adhesive tape according to at least one of the preceding claims, characterized in that 5 to 15 parts by weight of tackifier (based on the mass of the dried polymer dispersion) are added to the adhesive, preferably 5 to 12, more preferably 6 to 10 parts by weight of tackifier (based on the mass of the dried polymer dispersion) Polymer dispersion). Adhesive tape according to at least one of the preceding claims, characterized in that the glass transition temperature of the PSA is below +15 ° C (determined with DSC (differential scanning calorimetry) according to DIN 53 765 at a heating rate of 10 K / min). Adhesive tape according to at least one of the preceding claims, characterized in that the pressure-sensitive adhesive according to ASTM D3330 has a bond strength on steel of at least 2.0 N / cm (with a basis weight of the adhesive of 100 g / m ² on polyester fabric as carrier). Adhesive tape according to at least one of the preceding claims, characterized in that the carrier is a textile carrier, preferably a nonwoven material or a fabric, in particular a polyester fabric. Adhesive tape according to at least one of the preceding claims, characterized in that the carrier is fabric, preferably a polyester fabric and is further preferably constructed as follows: ● the number of threads in the warp is 10 to 60 / cm ● the number of threads in the weft is 10 to 40 / cm ● the warp threads have a yarn weight between 40 and 400 dtex, in particular between 44 and 330 dtex, particularly preferably 167 dtex ● the weft threads have a yarn weight between 40 and 660 dtex, in particular between 44 and 400 dtex, particularly preferably 167 dtex Adhesive tape according to at least one of the preceding claims, characterized in that the textile carrier, preferably a fleece, is provided on the underside with an applied film (film between the textile carrier and adhesive). Use of an adhesive tape according to at least one of the preceding claims for sheathing elongated goods, the adhesive tape being guided around the elongated goods in a helical line. Use of an adhesive tape according to at least one of the preceding claims for wrapping elongated material, the elongated material being encased by the tape in the axial direction. Elongated material, such as in particular a cable set, sheathed with an adhesive tape according to at least one of the preceding claims. Vehicle containing encased elongated goods according to Claim 14 .

Images