WO2007068596A1

WO2007068596A1 - Rolled strip made from a tpu film

Info

Publication number: WO2007068596A1
Application number: PCT/EP2006/069111
Authority: WO
Inventors: Bernhard MÜSSIG
Original assignee: Tesa Ag
Priority date: 2005-12-14
Filing date: 2006-11-30
Publication date: 2007-06-21
Also published as: DE102005060232A1; JP2009519365A

Abstract

The invention relates to a flame-resistant halogen-free rolled strip with a film made from thermoplastic polyurethane characterised in that a flame-retardant agent based on phosphorus is chemically incorporated.

Description

description

Wrap tape made from a TPU FoMe

The present invention relates to a halogen-free flame-retardant preferably colored winding tape, which further preferably has an adhesive coating and which is used for example for wrapping ventilation ducts in air conditioners, wires or cables and which is particularly suitable for wiring harnesses in vehicles or field coils for picture tubes. The wrapping tape serves for bundling, isolating, marking or protecting.

Cable wrapping tapes and insulating tapes are usually made of plasticized PVC film with a one-sided pressure-sensitive adhesive coating. There is an increasing desire to eliminate the disadvantages of these products, such as the evaporation of plasticizers and the high halogen content.

The plasticizers of conventional insulating tapes and cable wrapping tap gradually, resulting in a health burden, in particular, the commonly used DOP is questionable. Furthermore, the vapors in vehicles impact on the windows, which deteriorates the visibility (and thus considerably the driving safety) and is referred to by the expert as fogging (DIN 75201). With even greater evaporation by higher temperatures, for example in the engine compartment of vehicles or insulating tapes in electrical equipment, the winding band embrittled by the resulting plasticizer loss and the decomposition of the PVC polymer. Against the background of the discussion about the incineration of plastic waste, for example shredder waste from vehicle recycling, there is a trend towards the reduction of the halogen content and thus the dioxin formation. Therefore, the wall thicknesses of the cable insulation and the thicknesses of the tapes of the PVC film used for wrapping are reduced. The usual thickness of the PVC films for winding tapes is 85 to 150 microns. Below 85 μm, considerable problems occur in the calendering process, so that such products with reduced PVC content are scarcely available.

The usual wrap bands contain stabilizers based on toxic heavy metals such as lead, cadmium or barium.

State of the art for the bandaging of cable sets are wrapping tapes with and without adhesive coating, which consist of a PVC carrier material which is flexibly adjusted by incorporation of considerable amounts (30 to 40% by weight) of plasticizer. The carrier material is usually coated on one side with a self-adhesive composition based on SBR rubber. JP 10 001 583 A1, JP 05 250 947 A1, JP 2000 198 895 A1 and JP 2000 200 515 A1 describe typical plasticized PVC adhesive tapes. In order to achieve a higher flame resistance of the soft PVC materials, the highly toxic compound antimony oxide is usually used, as described, for example, in JP 10 001 583 A1.

Efforts are being made to use woven or non-woven fabrics instead of soft PVC film. However, the resulting products are rarely used in practice since they are relatively expensive and have a lot to do with handling (eg hand tearability, elastic recovery) and under conditions of use (for example resistance to moisture or operating fluids) distinguish, where - as stated below - the thickness has a special meaning. Such thick nonwovens make the wiring harnesses even thicker and less flexible than traditional PVC tapes, even if this has a positive effect on the sound insulation, but this is only advantageous in some areas of cable harnesses. However, nonwovens are not very stretchy and have virtually no resilience. This is important because thin branches of wiring harnesses must be wrapped so tightly that they do not hang slack down during installation and can be easily positioned before clipping and fitting the connectors. Another disadvantage of textile adhesive tapes is the low breakdown voltage of about 1 kV, because only the adhesive layer isolated. On the other hand, foil tapes are over 5 kV, they are good voltage resistant. Textile wrapping tapes are either not flameproof or contain halogen compounds (usually bromine compounds) as flame retardants. Examples can be taken from DE 200 22 272 U1, EP 1 123 958 A1, WO 99/61541 A1 and US Pat. No. 4,992,331 A1.

Thermo-polyester wrap tapes and cable insulation are being used tentatively to make wiring harnesses. These have significant deficiencies in terms of their flame resistance, flexibility, processability, aging resistance or compatibility with the cable materials. The most serious disadvantage of polyester, however, is the considerable sensitivity to hydrolysis, so that use for safety reasons in automobiles is no longer an option. Polyester-based wrapping tapes are either non-flame resistant or contain halogen compounds as flame retardants. Examples can be found in DE 100 02 180 A1, JP 10 149 725 A1, JP 09 208 906 A1, JP 05 017 727 A1 and JP 07 150 126 A1.

Wrappers made of polyolefins are also described in the literature. However, these are easily flammable or contain halogenated flame retardants. In addition, the materials made from ethylene copolymers have too low a softening point (they usually melt already in an attempt to test heat aging resistance), and in the case of the use of conventional polypropylene polymers, the material is usually too inflexible. Although metal hydroxides are sometimes used, but the amounts of 40 to 100 phr are too low for adequate flame retardancy, that is, they are not only not self-extinguishing, but even have a relatively high rate of fire (for example, over 100 mm / min to MVSS 302 ) on. Films with more than 100 phr of flame retardants are technically difficult to produce. In addition, such films have low tear resistance and are very rigid, that is, the essential processing properties of a typical PVC wrap band is missed.

WO 00/71634 A1 describes a wound adhesive tape whose film consists of an ethylene copolymer as the base material. The carrier film contains the halogen-containing flame retardant decabromodiphenyl oxide. The film softens below a temperature of 95 ° C, but the normal service temperature is often above 100 ° C or even over 130 ° C for a short time, which is not uncommon when used in the engine compartment. WO 97/05206 A1 describes a halogen-free wound adhesive tape whose carrier film consists of a polymer blend of low-density polyethylene and an ethylene / vinyl acetate or ethylene / acrylate copolymer. As flame retardants, 40 to 90 phr of aluminum hydroxide or ammonium polyphosphate are used. A significant disadvantage of the carrier film is again the low softening temperature. To counteract this, the use of silane crosslinking is described. However, this crosslinking method only leads to very non-uniformly crosslinked material, so that in practice no stable production process or uniform quality of the product can be realized.

Analogous problems of lack of heat resistance occur in the electrical adhesive tapes described in WO 99/35202 A1 and US Pat. No. 5,498,476 A1. The carrier film material described is a blend of EPDM and EVA in combination with ethylenediamine phosphate as flame retardant. This has a high sensitivity to hydrolysis, as does ammonium polyphosphate. In combination with EVA embrittlement on aging also occurs. The application on conventional cables made of polyolefin and aluminum or magnesium hydroxide leads to poor compatibility. In addition, the fire behavior of such wiring harnesses is poor because these metal hydroxides are antagonistic with phosphorus compounds as set forth below. The insulating tapes described are too thick and too stiff for wiring harnesses.

Attempts to solve the dilemma of too low softening temperature, flexibility, flame retardance and freedom from halogens are described below.

EP 0 953 599 A1 claims a polymer blend of LLDPE and EVA for cable insulation applications and as a sheet material. As a flame retardant, a combination of magnesium hydroxide with a special surface and red phosphorus described, the softening at a relatively low temperature is, however, accepted. The amount of magnesium hydroxide is 63 phr. Because of the despite high filler content unsatisfactory fire properties red phosphorus is used.

A very similar combination is described in EP 1 097 976 A1. However, in order to improve heat distortion resistance, a PP polymer is used instead of the LLDPE. used, which has a higher softening temperature. The disadvantage, however, is the resulting low flexibility. For blending with EVA or EEA it is said that the film has sufficient flexibility. However, it is known to the person skilled in the art that these polymers are blended with polypropylene to improve flame retardancy. The products described have a film thickness of 0.2 mm, but this thickness excludes flexibility in filled polyolefin since it depends on the 3rd power of the thickness. The method of extrusion described is hardly feasible on a production line at the extremely low melt indices of the poly olefins used, as known to the person skilled in the art, and certainly not for a practical thin film. The extremely low melt index limits the use to 50 to 100 phr of magnesium hydroxide.

Both approaches are based on the well-known synergistic flame retardancy of red phosphorus with magnesium hydroxide. The use of elemental phosphorus, however, involves considerable disadvantages and dangers. The processing releases foul-smelling, self-igniting and highly toxic phosphine. Even the finished wrapping tape smells like garlic in a hot and humid environment. Another disadvantage arises from the formation of very dense, white smoke in case of fire. In addition, only brown to black products can be produced, but wrapping tapes are used for color coding in a wide range of colors.

JP 2001 049 208 A1 describes an oil and heat-resistant film for an adhesive tape, in which both layers comprise a mixture of EVA or EEA, peroxide crosslinker, silane crosslinker, catalyst for the silanol condensation and flame retardant (100 phr of magnesium hydroxide). This film solves neither the problem of poor flexibility of a filled polypropylene film, nor the high demands on the aging resistance.

WO 03/070848 A1 describes a film of reactive polypropylene and 40 phr of magnesium hydroxide. This additional amount is not sufficient for a significant improvement of the fire behavior.

The cited prior art documents lead because of the disadvantages mentioned, in particular lack of flame retardancy, flexibility, tear resistance and / or Heat resistance, no films, which also solve the other requirements such as hand tearability, compatibility with Polyolefinkabelisolierung or sufficient unwind force. In addition, processability in film forming processes, high fogging value and breakdown voltage strength remain questionable. The main problem of the known inventions based on flame-retardant carrier films of polyolefin and metal hydroxide is the incompatibility of the mechanical requirements with those of flame resistance. With less than 60 wt .-% flame retardant (metal hydroxide and optionally other flame retardants) no self-extinguishing can be achieved and from 40 wt .-% flame retardant flexibility and tear resistance are hardly acceptable low level. The combination of polyolefin and metal hydroxide leads due to the mechanism of action (cooling by endothermic decomposition of the metal hydroxide and production of water vapor), although a slowing of the combustion process but not to a self-extinction. This system also has the disadvantage that during stretching in the winding process, in some cases even when the adhesive tape rolls off, it comes to white fracture. These bands are usually black and the finished roll then has a black-gray peeled surface. At high filler content, the tensile strength can be so low that the tape breaks during unrolling.

Adhesive tapes made of polyurethane (PU) are known, some with flame retardant equipment. These are mostly tack-sensitively treated PU foams and also foil-based adhesive tapes explained below.

JP 2001 020 178 A1 describes a double-sided adhesive tape for electromagnetic shielding made of a polyester fabric and a halogen-containing PU layer.

JP 2001 288 430 A1 describes a flame-retardant adhesive tape whose support has been produced from a polyurethane resin solution and dicyandiamide. The use of a solution cast film is not only expensive, but also does not meet the ecological goals of the tape of the invention from a film which is to be prepared solvent-free by thermoplastic processing. Attempts to incorporate dicyandiamide in thermoplastic polyurethane (TPU) have failed due to decomposition of the TPU during compounding. JP 2003 013 026 A1 and JP 2004 115 608 A1 describe (masking) adhesive tapes for handling radioactive substances, whose carrier is also produced from solution. It consists of a polyurethane resin solution and hydrazodicarbonamide. Hydrazodicarbonamide acts as a foaming agent upon thermoplastic processing by decomposition and would be unsuitable for high melting point hard block TPU (ie, high processing temperature).

JP 62 069 640 A1 describes a transparent adhesive tape for the production of wafer chips. The PU carrier, which may optionally contain a flame retardant such as 4,4'-dichlorohexylmethane diisocyanate, is prepared from solution.

DE 203 06 801 U1 describes an adhesive tape made of a polyurethane film, without specifying the polyurethane composition. However, polyurethane tapes have been known in practice for many years. In this utility model is described that the film may also contain additives, called UV and ozone stabilizers, fillers or flame retardants. For the latter, ammonium polyphosphate, antimony trioxide and aluminum trihydrate (ATH) are listed by name, but not substantiated by way of examples. Experiments have shown that ammonium polyphosphate (APP) degrades polyurethanes during thermoplastic processing, which is not surprising to the person skilled in the art, since APP is hygroscopic and therefore can cause hydrolytic degradation. In addition, due to the acidity of the APP, the hydrolysis is additionally catalyzed. APP, as a strong ionic salt, also causes poor electrical properties, as is known from use in other materials, for example wire insulation compounds. However, the winding tape according to the invention should also have good insulating properties. As is further known to those skilled in the art, antimony trioxide only works in combination with halogens and therefore makes no sense in TPU alone. It is also known to the person skilled in the art that ATH is suitable as flame retardant only for PE and EVA, since it has a low decomposition temperature, but not for polypropylene and therefore certainly not for TPU with even higher processing temperature.

EP 1 108 768 A1 describes an exclusively colorless adhesive tape with TPU carrier for the gluing of joints in aircraft. However, the adhesive tape according to the invention is intended for winding applications, in particular wire bundles in vehicles. In practice, such winding tapes are black, colored less colored and practically never colorless. The adhesive tape claimed in the specification is additionally limited to a transparent polyurethane pressure-sensitive adhesive, but the winding tape according to the invention must have a penetrating unwinding force or adhesive force on the back in order to be applied in a slightly stretched state to the object to be wrapped. For this purpose, however, essentially adhesives of polyacrylate, natural or synthetic rubber are suitable. The claimed tape must have a thickness of at least 9 mils, that is, the film has a minimum thickness of 8 mils (0.2 mm) to meet the Boeing BSS 7230 F2 standard. The claimed in the publication adhesive tape also contains bromine-containing flame retardants, but the invention is halogen-free.

JP 2005 264 1 12 A describes an adhesive tape with a carrier consisting of copolyamide as the main component and secondary components. The latter are polyurethane and nitrogen compounds. The document teaches that the addition of polyurethane improves the flexibility of a pure polyamide film, but greatly reduces the scratch resistance in larger quantities, therefore, the proportion of polyamide should be 40 to 90 parts. As flame retardants hydrazodicarbonamide, mono-, di-, tricyanoethyl cyanurate, melamine cyanurate and dicyandiamide are mentioned. Preference is given to a combination of hydrazodicarbonamide and melamine cyanurate. The latter has proven itself as a flame retardant for polyamides (see, for example, JP 11 349 809 A1), whereas hydrazodicarbonamide is actually unsuitable for thermoplastic processing for the abovementioned reasons. However, the document describes a processing temperature of only 150 to 160 ° C, so that processing for compounds with low softening temperature appears realistic. The reason for this is the low melting temperatures of the selected raw materials, for the polyurethane 60 to 120 ° C and for the polyamide 100 to 180 ° C mentioned in the examples, a polyamide with 133 ° C softening point is used. However, the film for the winding tape according to the invention should have the highest possible temperature resistance, ie a short-time heat resistance at 170 ° C and a heat resistance at 140 ° C, therefore, a TPU with significantly higher softening point is required than the mentioned in the document TPUs for modifying the polyamide film. Also due to the desired strength and Moduli TPU raw materials should be used with a relatively high melting Hartblockanteil for the winding tape according to the invention, resulting in processing temperatures of 200 ° C and more. The mentioned in Scripture polyamide film is mentioned that they can no longer be processed from 180 ° C. The film has a thickness of 0.2 mm. The adhesive tape described is phosphorus-free.

The film for the winding tape according to the invention would not be produced with the mentioned in the text preferred combination of hydrazodicarbonamide and melamine cyanurate because of the decomposition at high temperatures, which is required for the processing of TPU with high-melting hard blocks or high Shore hardness.

Furthermore, adhesive tapes have been known with supports of crosslinked non-thermoplastic polyurethane. No. 5,807,637 A describes an adhesive tape with a pressure-sensitive adhesive and a sealing layer, the underlying film contains calcium carbonate as the filler and is therefore not flameproof. However, US Pat. No. 6,129,983 A describes an analogous product with two pressure-sensitively adhesive layers.

EP 1 101 807 A1 mentions a mask adhesive tape with a composite carrier of crosslinked polyurethane and polyester. The PU layer may be modified with fillers, flame retardants are not mentioned.

The adhesive tape carriers mentioned are produced by in-line metering and mixing of polyol, isocyanate and catalyst on an auxiliary carrier. The advantage lies in low raw material costs compared to TPU, however the process is very difficult to realize in practice. Since the carriers are crosslinked, is also a thermoplastic

Recycling not possible. The main disadvantage of the mentioned in the documents

Subject of the invention, however, is the lack of suitability for winding tapes, since they have neither flame retardancy nor a sufficient tensile strength, which results in TPU from the physical crosslinking on the hard blocks.

EP 1 469 052 A1 and EP 1 469 024 A1 describe adhesive tapes with crosslinked polyurethanes as pressure-sensitive adhesives on any supports, but not TPU films.

US Pat. No. 5,858,495 A1 describes a very thick luminescent adhesive tape whose support is produced by polymerization of a mixture of a polyester or polyurethane acrylate and a luminescent pigment. This material is not a TPU from the chemical structure but a very hard urethane group-containing hard polymer. The object of the invention is to find a solution for a winding tape which combines the advantages of halogen freedom, flame retardancy, heat resistance, abrasion resistance, and the mechanical properties such as tensile strength and flexibility of PVC winding tapes with the halogen freedom of textile non-flame-resistant winding tapes and beyond a superior Heat aging resistance, wherein a large-scale producibility of the film should be ensured and a high breakdown voltage strength is necessary in some applications. Due to the absence of heavy metal stabilizers and phthalate plasticizers, the wrapping tapes should be hygienic and ecologically beneficial. The complete or substantial abandonment of plasticizers, in particular DOP, is desirable in order to achieve high fogging values and to avoid the consequences of plasticizer migration in the adhesive, such as telescoping or edge tackiness. The object of the invention is also to provide such winding tapes are available, which allow a particularly safe and fast wrapping, especially of wires and cables for marking, protecting, insulating, sealing or bundling, the disadvantages of the prior art, or not at least occur in the previous extent. It is then the task of finding thermoplastically produced films with additive combinations which not only reach, but even exceed the heat resistance of PVC.

This object is achieved by a winding tape, as laid down in the main claim. The subject of the dependent claims are advantageous developments of the subject invention and uses of the winding tape according to the invention.

Accordingly, the invention relates to a halogen-free flame-retardant winding tape with a thermoplastic polyurethane film in which a phosphorus-based flame retardant is chemically incorporated.

In a first particularly preferred embodiment, an adhesive, in particular a pressure-sensitive adhesive, is applied at least on one side of the carrier film. Surprisingly and unpredictably to a person skilled in the art, the thermoplastic polyurethane with built-in flame retardant based on phosphorus, which forms the carrier for the strip, can be produced as follows.

The polyurethane is optionally in the presence of catalysts (E) by reacting an NCO-containing prepolymer

A) at least one organic diisocyanate and

B) at least one polyol having an average of at least 1, 8 and at most 3.0 Zerewitinoff-active hydrogen atoms and a number average molecular weight M _n of 450 to 10,000 daltons with

C) at least one low molecular weight polyol or polyamine having on average at least 1, 8 and at most 3.0 Zerewitinoff-active hydrogen atoms and a number average molecular weight M _n of 60 to 400 daltons as chain extender and

D) at least one organic phosphorus-containing compound based

Phosphonate and / or phosphine oxide having an average of at least 1, 5 and at most 3.0 Zerewitinoff-active hydrogen atoms and a number average molecular weight M _n of 60 to 10,000 daltons in an amount of 1 to 15 wt .-%, based on the TPU, which is the following Having structural formula

(Formula 1 )

With

R ¹ , R ² branched or unbranched alkylene radicals having 1 to 24 carbon atoms, substituted or unsubstituted arylene radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkylene radicals having 6 to 30 carbon atoms, substituted or unsubstituted alkarylene radicals having 6 to 30 carbon atoms

Atoms, where R ¹ and R ^{2 may be the} same or different,

R ³ H, branched or unbranched alkyl radicals having 1 to 24 carbon atoms, substituted or unsubstituted aryl radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkyl radicals having 6 to 30 carbon atoms, substituted or unsubstituted alkaryl radicals with 6 to 30 carbon atoms,

x, y = 1 to 50

or which has the following structural formula

(Formula 2) with R ¹ H, branched or unbranched alkyl radicals having 1 to 24 carbon atoms, substituted or unsubstituted aryl radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkyl radicals having 6 to 30 carbon atoms, substituted or unsubstituted alkaryl radicals having 6 to 30 C atoms,

R ² , R ³ branched or unbranched alkylene radicals having 1 to 24 carbon atoms, substituted or unsubstituted arylene radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkylene radicals having 6 to 30 carbon atoms, substituted or unsubstituted alkarylene radicals having from 6 to 30 carbon atoms, where R ² and R ^{3 may be} identical or different,

optionally using

F) at least one further halogen-free flame retardant which contains no Zerewitinoff-active hydrogen atoms and has a number-average molecular weight M _{n of} from 60 to 10,000 in an amount of from 0 to 70% by weight, based on the TPU,

and or

G) 0 to 20 wt .-%, based on the total amount of TPU, other auxiliaries and additives,

wherein the index (formed from the multiplied by 100 quotient of the equivalence ratios of the isocyanate groups from (A) and the sum of the Zerewitinoff-active hydrogen atoms of the compounds (B), (C) and (D)) is 85 to 120,

produced.

The polyurethane is formed into a film and preferably coated on at least one side with an adhesive.

In a preferred embodiment of the invention, the components (B) and (C) of component (D) are different.

As organic diisocyanates (A) it is possible to use aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic diisocyanates or any desired mixtures of these diisocyanates (cf. HOUBEN-WEYL "Methods of Organic Chemistry", Volume E 20 "Macromolecular Materials", Georg Thieme Verlag, Stuttgart, New York 1987, pages 1587 to 1593 or Justus Liebigs Annalen der Chemie, 562, pages 75 to 136).

Specific examples are: aliphatic diisocyanates such as ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate; Cycloaliphatic diisocyanates such as isophorone diisocyanate, 1, 4-cyclohexane diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate and 1-methyl-2,6-cyclohexane diisocyanate and the corresponding isomer mixtures, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate and 2 , 2'-dicyclohexylmethane diisocyanate and the corresponding isomer mixtures; also aromatic diisocyanates such as 2,4-tolylene diisocyanate, mixtures of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate, mixtures of 2,4 '- Diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'-diphenylmethane diisocyanates or 2,4'-diphenylmethane diisocyanates, 4,4'-diisocyanatodiphenylethane (1, 2) and 1, 5-naphthylene diisocyanate. Preferably used are 1,6-hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate isomer mixtures having a 4,4'-diphenylmethane diisocyanate content of more than 96% by weight and in particular 4,4'-diphenylmethane diisocyanate and 1,5 - Naphthylene diisocyanate.

The diisocyanates mentioned can be used individually or in the form of mixtures with one another. They may also be used together with up to 15 mol% (calculated on total diisocyanate) of a polyisocyanate.

However, it may be added at most as much polyisocyanate that a still thermoplastically processable product is formed.

Examples of polyisocyanates are triphenylmethane-4,4 ', 4 "-triisocyanate and polyphenyl polymethylene polyisocyanates.

The most preferred isocyanate is 4,4'-diphenylmethane diisocyanate. Zerewitinoff-active polyols (B) which are used in the products of the invention are those having on average at least 1, 8 to at most 3.0 Zerewitinoff-active hydrogen atoms and a number average molecular weight M _n of 450 to 10,000 daltons. Due to production, these often contain small amounts of nonlinear compounds. Therefore, one often speaks of "substantially linear polyols." Preference is given to polyester, polyether, polycarbonate diols or mixtures of these.

Included are in addition to amino groups, thiol groups or carboxyl-containing compounds in particular two to three, preferably two hydroxyl-containing compounds, especially those with number average molecular weights M _n from 450 to 6000 daltons, particularly preferably those having a number average molecular weight M _n of 600 to 4500 daltons, for example Hydroxyl-containing polyesters, polyethers, polycarbonates and polyesteramides.

Suitable polyether diols can be prepared by reacting one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical with a

Starter molecule, which contains two active hydrogen atoms bound, converts.

As alkylene oxides may be mentioned, for example:

Ethylene oxide, 1, 2-propylene oxide, epichlorohydrin and 1, 2-butylene oxide and 2,3-butylene oxide. Preferably used are ethylene oxide, propylene oxide and mixtures of 1, 2-

Propylene oxide and ethylene oxide. The alkylene oxides can be used individually, alternately in succession or as mixtures.

Suitable starter molecules are, for example:

Water, amino alcohols, such as N-alkyldiethanolamines, for example N-methyldiethanolamine and diols, such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol and 1,6.

Hexanediol. Optionally, mixtures of starter molecules can be used.

Suitable polyetherols are also the hydroxyl-containing polymerization of tetrahydrofuran. It is also possible to use trifunctional polyethers in proportions of from 0 to 30% by weight, based on the bifunctional polyethers, but at most in such an amount that a still thermoplastically processable product is formed. The im

Substantially linear polyether diols preferably have number average

Molecular weights M _n from 450 to 6000 daltons. They can be both individually and in

Form of mixtures with each other are used. Suitable polyester diols can be prepared, for example, from dicarboxylic acids having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, and polyhydric alcohols. Examples of suitable dicarboxylic acids are aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid and sebacic acid or aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids may be used singly or as mixtures, for example in the form of an amber, glutaric and adipic acid mixture. For the preparation of the polyester diols, it may be advantageous to use, instead of the dicarboxylic acids, the corresponding dicarboxylic acid derivatives such as carbonic diesters having 1 to 4 carbon atoms in the alcohol radical, carboxylic anhydrides or carboxylic acid chlorides. Examples of polyhydric alcohols are glycols having 2 to 10, preferably 2 to 6 carbon atoms, for example ethylene glycol, diethylene glycol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 10-decanediol, 2,2 Dimethyl 1, 3-propanediol, 1, 3-propanediol or dipropylene glycol. Depending on the desired properties, the polyhydric alcohols may be used alone or mixed with each other. Also suitable are esters of carbonic acid with the diols mentioned, in particular those having 4 to 6 carbon atoms such as 1, 4-butanediol or 1, 6-hexanediol, condensation products of omega-hydroxycarboxylic acids such as omega-hydroxycaproic acid or polymerization products of lactones, for example optionally substituted omega caprolactones. Preferred polyester diols used are ethanediol polyadipates, 1,4-butanediol polyadipates, ethanediol-1,4-butanediol polyadipates, 1,6-hexanediol neopentyl glycol polyadipates, 1,6-hexanediol-1,4-butanediol polyadipates and polycaprolactones. The polyester diols have number average molecular weights M _n of 450 to 10,000 daltons and can be used individually or in the form of mixtures with one another.

The preferred diol is a hydroxylated polymerization product of tetrahydrofuran because such TPUs are relatively stable to hydrolysis, microbial degradation and oxidation.

Zerewitinoff-active polyols (C) are so-called chain extenders and have an average of 1, 8 to 3.0 Zerewitinoffaktiv hydrogen atoms and have a molecular weight of 60 to 400 daltons. By this is meant besides amino groups, thiol groups or Carboxyl-containing compounds having those having two to three, preferably two hydroxyl groups.

As chain extenders are preferably used aliphatic diols having 2 to 14 carbon atoms such as ethanediol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-butanediol, 2,3-butanediol, 1, 5-pentanediol, 1, 6 Hexanediol, diethylene glycol and dipropylene glycol. Also suitable, however, are diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, for example terephthalic acid bis-ethylene glycol or terephthalic acid bis-1,4-butanediol, hydroxyalkylene ethers of hydroquinone, for example 1,4-di (beta-hydroxyethyl) hydroquinone ethoxylated bisphenols for example 1,4-di (beta-hydroxyethyl) bisphenol A, (cyclo) aliphatic diamines such as isophoronediamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, N-methyl-propylene-1,3 -diamine, N, N'-dimethylethylenediamine and aromatic diamines such as 2,4-toluenediamine, 2,6-toluylenediamine, 3,5-diethyl-2,4-toluenediamine or 3,5-diethyl-2,6-toluenediamine or primary mono-, di-, tri- or tetraalkyl-substituted 4,4'-diaminodiphenylmethanes. Ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-di (beta-hydroxyethyl) hydroquinone or 1,4-di (beta-hydroxyethyl) bisphenol A are particularly preferably used as chain extenders. It is also possible to use mixtures of the abovementioned chain extenders. In addition, smaller amounts of triols can be added.

The preferred chain extender is 1,4-butanediol.

The combination of 4,4'-diphenylmethane diisocyanate with 1, 4-butanediol provides hard blocks with sufficiently high resistance to melting of the samples under temperature load.

Compounds which are monofunctional towards isocyanates can be used in proportions of up to 2% by weight, based on TPU, as so-called chain terminators. Suitable examples are monoamines such as butyl and dibutylamine, octylamine, stearylamine, N-methylstearylamine, pyrrolidine, piperidine or cyclohexylamine, monoalcohols such as butanol, 2-ethylhexanol, octanol, dodecanol, stearyl alcohol, the various amyl alcohols, cyclohexanol and ethylene glycol monomethyl ether. The flame retardants (D) have on average at least 1, 5 and at most 3.0, preferably 1, 8 to 2.5, particularly preferably 2 Zerewitinoff-active hydrogen atoms. These Zerewitinoff-active hydrogen atoms are preferably based on alcohol or amine. The flame retardants (D) have a number average molecular weight M _n of 60 to 10,000 daltons, preferably 100 to 5000 daltons, particularly preferably 100 to 1000 daltons. The flame retardants (D) are based on phosphonate and / or phosphine oxide. The phosphonate used is compounds of the general formula 1 (see above). The phosphine oxide used are compounds of the general formula 2 (see above). The flame retardants (D) are preferably used in an amount of 1 to 15, particularly preferably 1 to 10 wt .-% based on the total amount of TPU.

As an optional additional halogen-free flame retardant (F), the halogen-free flame retardants known from the prior art can be used. Of these, only a few are known since polyurethanes are in practice largely provided with bromine- or chlorine-containing flame retardants. The halogen-free ones include special graphites, ammonium polyphosphate, aluminum hydroxide, melamine cyanurate, melamine, phosphoric acid and phosphonic acid esters such as, for example, diphenyl cresyl phosphate. Because of the resulting mechanical and electrical data and aging stability, organic phosphorus and nitrogen linkages are preferred. Some may degrade transparency like inorganic flame retardants. Although it is not the primary goal to generate transparent wrapping tapes, but the possibility of a colorless film has the advantage that the winding tape can be produced in different colors by colored primer (or printing) or colored PSAs with high flexibility in the process. Phosphoric and phosphonic acid esters behave favorably in this respect and are therefore preferred. As the sole flame retardant but quite high levels are required to achieve the flame retardancy, which can reduce the force at 50% elongation too far and / or produce by plasticizer migration and / or exudation adhesive problems or fogging. The fact that an organic phosphorus compound is incorporated in the film of the winding tape according to the invention, these problems can be avoided. Organic phosphorus compounds such as phosphoric acid esters, which melt during thermoplastic processing, in contrast to flame retardants in the form of Fillers produce no holes in the films, which reduce the breakdown voltage.

Particularly preferred are hydrocarbyl (dihydrocarbylphosphate) of the general formula

O O

V Il

RO- (POAOP) _n -OR

RO OR

wherein R preferably an aryl group (for example, phenyl, cresyl), A is a connecting

Group such as arylene (for example phenylene), biarylene (for example biphenyl), two arylene groups which are connected by another group such as -CH 2 -, -C (CH 3) 2 -, -SO 2 - or - CO-, or alkylene (zum Example neopentyl) and n is between 1 and 10. Such compounds are industrially prepared from phosphoric acid or phosphorus oxytrichloride and diphenols such as resorcinol or bisphenol A (which then form group A) and monophenols such as phenol and cresol (which then form the group R). Preference is given to phosphoric acid-1, 3-phenylene tetraphenyl esters and phosphoric acid-1, 3-phenylene tetraphenyl ester oligomers and bisphenol A bis (diphenylphosphate) and its oligomers.

Very particular preference is given to phosphoric acid and phosphonic acid derivatives which on hydrolysis release neither phenol nor cresol, examples of which are trixylyl phosphate, butylated triphenyl phosphates (for example Fyrquel ™ EHC-S), phosphoric acid 1,3-phenylene tetraxylenyl ester and salts of phosphonic acids such as sodium , Magnesium, zinc or aluminum salts of propane or phenylphosphonic acid (benzenephosphonic acid).

The relative amounts of the compounds (B), (C) and (D) are preferably chosen such that the ratio of the sum of the isocyanate groups in (A) to the sum of the Zerewitinoff-active hydrogen atoms in (B), (C) and (D) 0.85: 1 to 1, 2: 1, preferably 0.95: 1 to 1, 1: 1. The thermoplastic polyurethanes used in accordance with the invention may contain, as auxiliaries and additives (G), preferably up to a maximum of 20% by weight, based on the total amount of TPU, of the customary auxiliaries and additives. Typical auxiliaries and additives are nucleating agents, lubricants such as fatty acid esters, their metal soaps, fatty acid amides, fatty acid ester amides and silicone compounds, antiblocking agents, inhibitors, hydrolysis stabilizers, light stabilizers, antioxidants, dyes, pigments, inorganic and / or organic fillers, plasticizers such as adipates, sebacates and alkylsulfonic acid esters, fungistatic and bacteriostatic substances and fillers and their mixtures and reinforcing agents such as fibrous materials.

Further details of the abovementioned auxiliaries and additives can be found in the specialist literature, for example the monograph by J. H. Saunders and K.C. Frisch "High Polymers", Volume XVI, polyurethanes, Part 1 and 2, published by Interscience Publishers 1962 and 1964, the paperback for plastic additives by R. Gächter and H. Müller (Hanser Verlag Munich 1990) or DE 29 01 774 A1 remove.

The information given below in phr means parts by weight of the relevant component based on 100 parts by weight of all polymer components of the film.

The film used according to the invention preferably contains at least 1 phr and in particular at least 2 phr of stabilizers against oxidation and / or hydrolysis. Examples are phenolic or aminic based antioxidants and sulfur or phosphorus based secondary antioxidants. The wrap tapes of the invention preferably contain a combination of primary and secondary antioxidant, wherein the primary and secondary antioxidant function may be present in different molecules or may be combined in one molecule. The listed quantities do not include optional stabilizers such as metal deactivators or light stabilizers.

The amount of secondary antioxidant is preferably at least 0.5 phr, more preferably at least 1 phr.

To avoid the use of cumbersome lUPAC designations, some substances with their CAS no. characterized. Stabilizers for PVC products can not be transferred to TPU. Secondary antioxidants break down peroxides and are therefore used in diene elastomers as part of anti-aging packages. Surprisingly, it has been found that a combination of primary antioxidants (for example sterically hindered phenols or C radical scavengers such as CAS 181314-48-7) and secondary antioxidants (for example sulfur compounds, phosphites or sterically hindered amines), the two functions also in one Molecule can be united, the task also solves at dienstfreien TPU. Above all, the combination of primary antioxidant, preferably sterically hindered phenols having a molecular weight of more than 500 g / mol (preferably> 700 g / mol) with a phosphitic secondary antioxidant (preferably having a molecular weight> 600 g / mol) is preferred.

In particular, the combination of a low-volatile primary phenolic antioxidant and a secondary antioxidant from the class of sulfur compounds (preferably having a molecular weight of more than 400 g / mol, in particular> 500 g / mol) and from the class of phosphites is suitable in which the phenolic, sulfurous and phosphitic functions need not be present in three different molecules, but more than one function may be combined in one molecule.

Examples:

Phenolic Function: CAS 6683-19-8, 2082-79-3, 1709-70-2, 36443-68-2, 1709-70-2, 34137-09-2, 27676-62-6, 40601-76 -1, 31851-03-3, 991-84-4

• Sulfur-containing function:

CAS 693-36-7, 123-28-4, 16545-54-3, 2500-88-1, 16545-34-3, 29598-76-3

• Phosphitic function:

CAS 31570-04-4, 26741-53-7, 80693-00-1, 140221-14-3, 1 19345-01-6, 3806-34-6, 80410-33-9, 14650-60-8, 161717-32-4

Phenolic and sulphurous function: CAS 41484-35-9, 90-66-4, 110553-27-0, 96-96-5, 41484

• Phenolic and aminic function: CAS 991-84-4, 633843-89-0

• Aminic function:

CAS 52829-07-9, 41 1556-26-7, 129757-67-1, 71878-19-8, 65447-77-0

The combination of CAS 6683-19-8 (for example Irganox 1010) with thiopropionic acid ester CAS 693-36-7 (Irganox PS 802) or 123-28-4 (Irganox PS 800) with CAS 31570-04-4 (Irgafos 168) is particularly preferred. Further preferred is a combination in which the level of secondary antioxidant exceeds that of the primary. In addition, metal deactivators can be added to complex heavy metal traces, which can accelerate aging catalytically. Examples are CAS 32687-78-8, 70331-94-1, 6629-10-3, ethylenediaminetetraacetic acid, N, N'-di-salicylidene-1,2-diaminopropane, 3- (N-salicylol) -amino-1, 2,4-triazole (Palmarole ADK STAB CDA-1), N, N'-bis [3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionyl] hydrazide (Palmarole MDA.P. 10) or 2,2'-oxamido-bis- [ethyl-3- (tert-butyl-4-hydroxyphenyl) propionate] (Palmarole MDA.P.11.).

The selection of the mentioned anti-aging agents is of particular importance for the winding film according to the invention, since phenolic antioxidants alone or even in combination with sulfur-containing costabilizers can not always be used to achieve practical products. In calender processing, where a relatively long-lasting access of atmospheric oxygen is inevitable on the rollers, the concomitant use of phosphite stabilizers is found to be particularly suitable for sufficient heat aging stability of the product. Even in extrusion processing, the addition of phosphites in the aging test of the product is still positively noticeable. For the phosphite stabilizer, an amount of at least 0.1, preferably at least 0.3, phr is preferred.

As hydrolysis protection agent (G), for example, monomeric or polymeric

Carbodiimides, oxazolines or reactive polyureas are used. Preference is given to a polymeric carbodiimide based on aromatic isocyanates. For the production and Structure of such carbodimides see US 2,941, 956 A, JP 04 733 279 A, J. Org. Chem., 28, 2069-2075 (1963); Chemical Review, Vol. 81, No. 4, pp. 619 to 621 (1981). The preferred amount is 0.5 to 3 phr.

Other polymeric additives that can be incorporated into the TPU are thermoplastics such as polyethylenes, ethylene / vinyl acetate copolymers, polypropylene homopolymers or copolymers. Synthetic elastomers such as hydrogenated styrene-diene copolymers or thermoplastic polyurethanes without built-in flame retardant or non-meltable polymers such as EVA dispersion powder or impact modifier (for example acrylate elastomer particles with a shell of PAN or PMMA) can also be used. Preferably, no hydrolysis-sensitive polymeric additives having ester or amide groups in the polymer backbone are used.

Suitable catalysts (E) according to the invention are the tertiary amines known and customary in the prior art, for example triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N, N'-dimethylpiperazine, 2-

(Dimethylaminoethoxy) ethanol, diazabicyclo [2,2,2] octane and the like and in particular organic metal compounds such as titanic acid esters, iron compounds or tin compounds such as tin diacetate, tin dioctoate, tin dilaurate or Zinndialkylsalze aliphatic carboxylic acids such as dibutyltin diacetate or dibutyltin dilaurate or the like. Preferred catalysts are organic metal compounds, in particular titanic acid esters, iron and tin compounds. The total amount of catalysts in the TPU according to the invention is generally about 0 to 5 wt .-%, preferably 0 to 2 wt .-%, based on the total amount of TPU.

The TPU related to the invention may be produced continuously or discontinuously. The best known production methods are the belt process (GB 1 057 018 A) and the extruder process (DE 19 64 834 A1). The structure of the TPU can either step by step (Prepolymerdosierverfahren) or by the simultaneous reaction of all components in one step (one-shot dosing) take place. Preferably The incorporable phosphorus-containing compounds are incorporated in the prepolymer process in the TPU.

The addition of the flame retardant (F) and / or the auxiliaries (G) can be carried out before, during or after the polyurethane reaction.

The object of the present invention is primarily the absence of halogens with high flame retardancy, tear resistance and flexibility. As stated, the thermal requirements of the application increase, so that in addition an increased resistance to conventional PVC winding tapes or under development PVC-free film winding tapes is to be achieved polyolefin-based. Therefore, the characteristics of the present invention will be described below in detail.

The product according to the invention is halogen-free in the sense that the halogen content of the raw materials is so low that it plays no role in the flame retardance. Traces of trace halogens, such as impurities, process additives (fluoroelastomer) or catalyst residues, are not taken into consideration.

The elimination of halogens usually entails the property of flammability, which does not meet the safety requirements in electrical applications such as household appliances, buildings or vehicles. The winding tape according to the invention has self-extinguishing properties, the preferred embodiments of the winding tape automatically extinguishing in fire tests according to FMVSS 302 (horizontal sample) and / or ASTM D 568 (vertical sample).

The thickness of the film of the invention is preferably in the range of 30 to 180 .mu.m, preferably 50 to 150 .mu.m, in particular 55 to 100 microns. Thus, sufficient conformability in winding, good hand tearability and acceptable cost are achieved.

The winding tape according to the invention has a corresponding thickness increased by the thickness of the optional pressure-sensitive adhesive coating. The surface can be textured or smooth. Preferably, the surface is slightly dull. This can be done by using a filler with a sufficiently high particle size or be achieved by a roller (for example, embossing roll on the calender or frosted Chili ro 11 or embossing roll in the extrusion).

The carrier film of the invention is substantially free of volatile plasticizers such as DOP or DINP and therefore has excellent fire behavior and low emission (plasticizer evaporation, fogging). The fogging value is preferably over 90%. The film preferably contains 0 to 5 phr of phosphorus-free

Plasticizers, especially no phosphorus-free plasticizers. It preferably contains 0 to 10 phr of phosphorus-containing plasticizers as flame retardants and in particular no phosphorus-containing plasticizers at all.

The winding tape used according to the invention is preferably colored (black, white or colored), wherein the carrier film and / or a further layer such as the adhesive are colored. The pigments used are preferably free of toxic heavy metals such as lead, cadmium or chromium.

The winding tape according to the invention has a force at 10% elongation of 2 to 20 N / cm in the longitudinal direction, preferably from 4 to 1 1 N / cm, and at 50% elongation a force of 3 to 25 N / cm, preferably from 6 to 17 N / cm.

The 10% force is a measure of the stiffness of the film, and the 50% force is a measure of the conformability of winding in high deformation by high winding tension. However, the 50% force must not be too low, because otherwise the tear strength is usually too low.

The tensile strength (breaking strength) of the carrier film is at least 10 N / cm, preferably at least 20 N / cm.

Since TPUs can be very tough, measures may be required to improve the hand tearability of the wrapping tape, such as blending with

Fillers, incompatible thermoplastic or non-meltable polymers, by rough-cut side edges, which when examined microscopically cracks in the

Form film, which then apparently favor a tearing, or by later provided with, for example, by punching notches provided side edges. Rough cutting edges can be achieved in particular by the application of a Crush cut with blunt or defined jagged rotating knives on bales (jumbos, rolls in long lengths) or by a cut-off with fixed blades or rotating knives of bar stock (rolls in production width and commercial length) are produced. The elongation at break can be adjusted by a suitable grinding of the blades and blades. Preference is given to the execution of the production of bar stock with cut-away with blunt fixed blades. By strongly cooling the bars before cutting, the cracking during the cutting process can be improved.

Prerequisites for sufficient heat resistance and short-term heat resistance are a sufficient crystallite melting point of the TPU (preferably at least 158 ° C and more preferably at least 170 ° C) and a resistance to aging by degradation, which can be ensured by antioxidants and / or hydrolysis protection.

The winding tape according to the invention has a high temperature resistance, in preferred embodiments, an elongation at break of at least 100% after 312 hours storage at 140 ° C (heat resistance test) or a short-term heat resistance of 170 ° C (after 30 min no cracks or molten points) have.

To achieve these strength values as well as the heat resistance, the film of the winding tape contains a TPU with a sufficiently high proportion of hard blocks, which is why the Shore D hardness of the TPU raw material is preferably at least 35 and more preferably at least 50, which corresponds approximately to Shore A hardnesses of preferably at least 85 or particularly preferably at least 100. The flame-resistant adhesive tapes shown in the prior art use significantly softer TPU (Shore A 70 to 80) than the flame-resistant adhesive tapes with built-in flame retardant. If plasticizers or phosphoric acid esters are added to the adhesive tapes of such soft TPU as flame retardants, then these are much more inappropriate than the winding tapes according to the invention.

The film is produced on a calender or by extrusion such as

Example in the blowing or casting process. These methods are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, Wiley-VCH 2002. In the With the use of solid or liquid additives for the TPU, a compound of the main components or all components is prepared in a compounder such as kneader (for example, pad kneader) or extruder (for example, twin-screw extruder, planetary roller extruder) and then converted into a solid form (for example, granules) , which are then further processed in a film extrusion line or in an extruder, kneader or rolling mill calendering.

The polyurethane film is preferably coated on at least one side with an adhesive.

The amount of preferably present adhesive layer is 10 to 40 g / m ² , preferably 18 to 28 g / m ² (that is the amount after any necessary removal of water or solvent, the numerical values also correspond approximately to the thickness in microns). In a case with adhesive coating, the information given here on the thickness and thickness-dependent mechanical properties relate exclusively to the TPU-containing layer of the winding tape without consideration of adhesive layer or other layers that are advantageous in connection with adhesive layers. The coating does not have to be full-surface, but may also be part-surface. As an example, a wrapping tape, each with a pressure-sensitive adhesive strip on the side edges is called. This can be cut into approximately rectangular sheets, which are glued with the one adhesive strip on the cable bundle and then wound until the other adhesive strip on the Wickelbanddrückseite can be glued. Such a tube-like envelope, similar to a sleeve packaging, has the advantage that the flexibility of the cable harness is practically not deteriorated by the wrapping.

As adhesive all common types in question, especially based on rubber. Such rubbers may be, for example, homopolymers or copolymers of isobutylene, of 1-butene, of vinyl acetate, of ethylene, of acrylic acid esters, of butadiene or of isoprene. Especially suitable are formulations based on polymers based on acrylic acid esters, vinyl acetate or isoprene.

In order to optimize the properties, the self-adhesive composition used may be combined with one or more additives, such as tackifiers (resins), plasticizers, fillers, flame retardants, pigments, UV absorbers, light stabilizers, anti-aging agents, mittein, photoinitiators, crosslinking agents or crosslinking promoters be blended. Tackifiers are, for example, hydrocarbon resins (for example polymers based on unsaturated C ₅ or Cg monomers), terpene-phenolic resins, polyterpene resins from raw materials such as α- or β-pinene, aromatic resins such as coumarone-indene resins or styrene-based or α-styrene resins Methyl styrene such as rosin and its derivatives, for example disproportionated, dimerized or esterified resins, for example reaction products with glycol, glycerol or pentaerythritol, to name but a few, and also other resins (such as listed in Ullmanns Enzyklopadie der technischen Chemie, Volume 12) , Pages 525 to 555 (4th edition), Weinheim). Preference is given to using resins without easily oxidizable double bonds, such as terpene-phenolic resins, aromatic resins and particularly preferably resins which are prepared by hydrogenation, for example hydrogenated aromatic resins, hydrogenated polycyclopentadiene resins, hydrogenated rosin derivatives or hydrogenated terpene resins.

Suitable fillers and pigments are, for example, carbon black, titanium dioxide, calcium carbonate, zinc carbonate, zinc oxide, silicates or silicic acid. Suitable miscible plasticizers are, for example, aliphatic, cycloaliphatic and aromatic mineral oils, di- or poly-esters of phthalic acid, trimellitic acid or adipic acid, liquid rubbers (for example low molecular weight nitrile or polyisoprene rubbers), liquid polymers of butene and / or isobutene, acrylic esters, polyvinyl ethers, Liquid and soft resins based on the raw materials of adhesive resins, wool wax and other waxes or liquid silicones. Crosslinking agents are, for example, isocyanates, phenolic resins or halogenated phenolic resins, melamine and formaldehyde resins. Suitable crosslinking promoters are, for example, maleimides, allyl esters, such as triallyl cyanurate, polyfunctional esters of acrylic and methacrylic acid. Anti-aging agents include, for example, hindered phenols, known, for example, under the trade name Irganox ™.

Crosslinking is advantageous because the shear strength (for example as lifting power) is increased and thus the propensity to deformation of the rolls during storage (telescoping or formation of voids, also called gaps) is reduced. The squeezing of the PSA is also reduced. This is expressed in tack-free side edges of the rollers and tack-free edges of the wound strip guided in a spiral movement around cables or a cable harness. The holding power is preferably above 150 min. The bond strength to steel should be in the range of 1.5 to 3 N / cm.

The winding tape according to the invention preferably has an unwinding force of from 1.2 to 6.0 N / cm, very particularly preferably from 1.6 to 4.0 N / cm and in particular from 1.8 to 2.5 N / cm at 300 mm / min Unwinding speed.

In summary, the preferred embodiment has on one side a solvent-free self-adhesive composition which has been produced by coextrusion, melt or dispersion coating. In particular, polyacrylate-based adhesives in the form of dispersions or hotmelts are preferred.

The use of a primer layer between the carrier film and adhesive is advantageous for improving the adhesion of the adhesive to the film and thus avoiding the transfer of adhesive to the film back during the unwinding of the rolls.

As primers, the known dispersion and solvent systems can be used, for example, based on isoprene- or butadiene-containing rubber and / or cyclo-rubber. Isocyanates or epoxy resins as additives improve the adhesion and in part also increase the shear strength of the pressure-sensitive adhesive. Physical surface treatments such as flame treatment, corona or plasma or coextrusion layers are also suitable for improving adhesion. Particularly preferred is the use of such methods on solvent-free adhesive layers, especially those based on acrylate.

A coating of the back can be carried out by known release agents (optionally blended with other polymers). Examples are stearyl compounds (for example polyvinyl stearyl carbamate, stearyl compounds of transition metals such as Cr or Zr), ureas of polyethyleneimine and stearyl isocyanate, polysiloxanes (for example as a copolymer with polyurethanes or as a graft copolymer on polyolefin), thermoplastic fluoropolymers. The term stearyl is synonymous with all straight ones or branched alkyls or alkenyls having a C number of at least 10 such as octadecyl.

Descriptions of the customary adhesives and backcoats and primers can be found, for example, in "Handbook of Pressure Sensitive Adhesive Technology", D. Satas, (3rd Edition).

The bar stock can be subjected to a heat storage to increase the unwind force or relaxation of the tensions of the films before cutting. The cutting of

Wrapping tapes with fabric, non-woven and film carrier (for example PVC) is carried out by

Paper cut (between two rotating knives), cut-off cut (fixed or rotating knives pressed into a rotating rod of the product),

Blade cut (the web is split when passing through sharp blades) or crimp cut (between a rotating blade and a roller).

The winding tape according to the invention is excellent for wrapping elongated material such as field coils or cable harnesses suitable in vehicles. The flexibility is of paramount importance, since, when used on wires and cables, it not only has to be wound in a spiral motion, but also has to be wound flexibly at bend points, plugs or fastening clips in a curve-flexible manner. In addition, it is desirable that the winding tape elastically contracts the wire harness. The wrapping tape according to the invention is also suitable for other applications such as for the sealing of ventilation pipes in the Klimabau, since the high flexibility ensures good conformability to rivets, beads and folds. These mechanical properties can only be achieved by a soft flexible wrapping tape. The object to achieve the necessary flexibility by avoiding the addition of larger amounts of flame retardants is achieved according to the invention.

The current occupational hygiene and ecological requirements are taken into account by dispensing with the use of halogen-containing raw materials. The absence of halogen is of utmost importance for the thermal utilization of wastes containing such winding tapes (for example, waste incineration of plastic waste). Group of vehicle recycling) but also in cable or building fires, since no toxic flue gases.

In the course of increasingly complicated electronics and the increasing number of electrical consumers in automobiles, the wiring harnesses are becoming ever more complex. With increasing cross sections of the harnesses, the inductive heating is getting larger, while the heat dissipation decreases. This increases the requirements for the heat resistance of the materials used. The standard PVC materials used for the winding tapes are reaching their limits here. This problem can now be considered solved.

Test Methods

The measurements are carried out at a test climate of 23 ± 1 ° C and 50 ± 5% rel. Humidity carried out.

The crystallite melting point (T _cr ) is determined by DSC according to ISO 3146. Since freshly processed TPUs have an extremely wide melting range because they are not yet in the thermodynamic final state of the crystallization, the samples are tempered for 24 hours at 140 ° C. before the crystallite melting point is determined.

The Shore A and Shore D hardness are determined according to ISO 868.

The hydrolysis resistance is determined by storage of the sample in warm distilled water. After 1000 hours at 80 ° C, the sample is dried for 24 hours at 80 ° C in a vacuum and then determines the decrease in tensile strength compared to the fresh state. If the tear strength is less than 50%, the test passes (P, passed) and if it has decreased by at least 50%, the test is failed (NP, not passed).

The tensile elongation behavior of the winding band is measured on type 2 test specimens (rectangular

150 mm long and, if possible, 15 mm wide test strip) according to DIN EN ISO 527-3 / 3/300 with a test speed of 300 mm / min, a clamping length of 100 mm and a pre-load of 0.3 N / cm determined. In the case of patterns with rough cut edges, the edges should be trimmed with a sharp blade before the tensile test. The tensile elongation behavior is tested in the machine direction (MD, direction of travel) unless otherwise specified. The force is expressed in N / stripe width and the elongation at break in%. The test results, in particular the elongation at break (elongation at break), must be statistically verified by a sufficient number of measurements.

Adhesive forces are determined at a deduction angle of 180 ° according to AFERA 4001 on (if possible) 15 mm wide test strips. In this case, steel plates according to the AFERA standard are used as the test substrate unless another primer is mentioned.

The thickness of the film is determined according to DIN 53370 (a possible pressure-sensitive adhesive layer is subtracted from the measured total thickness).

The Holding Power is determined according to PSTC 107 (10/2001), whereby the weight is 20 N and the dimensions of the bonding surface are 20 mm in height and 13 mm in width.

The unwind force is measured at 300 mm / min according to DIN EN 1944.

The hand tearability can not be expressed in numbers even though breaking strength, elongation at break, and tensile toughness (all measured longitudinally) are of substantial influence.

Rating:

+++ = very easy, - ++ = good,

+ = still processable,

= difficult to process, - = can only be torn off with great effort, the ends are unclean,

- = not processable

The fire behavior is measured according to FMVSS 302 (horizontal sample) or ASTM D 568 (vertical sample). In FMVSS 302 is the Pressure-sensitive adhesive coating upwards. These methods also allow determination of the burning rate of flammable samples. It is only judged whether the sample burns (not passed) until the second mark (end mark) is reached, or passes by itself before it (passed). The MVSS 302 (Engine Vecile Safety Standard, US) has also been further developed into an ISO standard (ISO 3795).

The temperature resistance is determined by two methods. The wrapping tape is first glued to a siliconized polyester film and stored in the heat. After the test time, the sample is cooled for 30 min at 23 ° C. The heat resistance test after 312 hours storage at 140 ° C is tested whether the elongation at break is still at least 100%. The test of short-term heat resistance is carried out by 30 minutes storage of the sample at 170 ° C, then winding at least 3 turns with 50% overlap around a mandrel of 10 mm diameter and then judging whether the pattern damages (for example, cracks, molten areas ) having.

In the cold test, the test specimen described above is cooled for 4 hours to -40 ° C. in accordance with ISO / DIS 6722 and the sample is hand-wound onto a 5 mm diameter mandrel. The samples are checked visually for defects (cracks) in the adhesive tape.

The breakdown voltage is measured according to ASTM D 1000. The number is taken to be the highest value that the sample withstands at this voltage for one minute. This number is converted to a sample thickness of 100 μm.

Example:

A sample of 200 μm thickness withstands a maximum voltage of 6 kV after one minute, the calculated breakdown voltage is 3 kV / 100 μm.

The fogging value is determined according to DIN 75201 A.

The following examples are intended to illustrate the invention without limiting its scope. Explanation of the PU raw materials used in the examples

Terathane ™ 1000: polyethers having a molecular weight of M _n = 1000 daltons (DuPont) MDI: 4,4'-diphenylmethane diisocyanate

Exolit ™ OP 560: flame retardant based on diol phosphonate with Zerewitinoff-active hydrogen atoms (Clariant GmbH)

Levagard ™ 4090 N: Flame retardant (Bayer AG) OP (OC25) 2CH2N (C2H4OH) 2

Cyagard ™ RF-1243 Diol Phosphine Oxide based flame retardant (Cytec Inc.) BDO: 1,4-butanediol

Irganox ™ 1010: tetrakis (methylene (3,5-di-tert-butyl-4-hydroxycinnamate)) -methane (Ciba

Specialty Chemicals)

Licowax ™ C: release agent (Clariant Würtz GmbH)

Disflamoll ™ DPK: Flame Retardant Diphenyl Cresyl Phosphate (Lanxess) KE 9463: Masterbatch of 20% Stabaxol ™ P100 and 80% TPU (Rhein-Chemie)

example 1

A mixture of 1045 kg of Terathane ™ 1000, 6.3 kg of Irganox ™ 1010 and 10 kg of Licowax ™ C was heated to 160 ° C while stirring with a paddle stirrer at a speed of 500 rpm, after which 713 kg of MDI was added. After reaching the maximum reaction temperature, stirring was continued for 30 seconds, after which 125 kg of BDO and 100 kg of Exolit ™ OP 560 were added. The mixture was then stirred for 100 s, after which the TPU was poured out. Finally, the material was post-treated at 80 ° C for 30 minutes.

The finished TPU was cut, granulated and fed to a compounder in the dry state. This fed the gap of an inverted-L calender, the processing temperatures were around 220 ° C. With the aid of the calender rolls, a film with a smooth surface of a thickness of 80 μm was formed.

The film was stored for one week, leveled on the coater with rollers at 60 ° C to improve the flatness and provided after a corona treatment on one side with a release layer and on the other with an aqueous Acrylic pressure-sensitive adhesive (Primal PS 83 D from Rohm and Haas and addition of 5% Hostasin Black [color preparation] from Clariant) using a doctor blade with a coating weight of 24 g / m ² . The finished wrapping tape was wound into bars of 33 m in length on a 1-inch core (25 mm). The cutting was done by cutting off the rods by means of fixed blade with not very acute angle (straight knife) in 29 mm wide rolls.

Example 2

A mixture of 1045 kg of Terathane ™ 1000, 6.3 kg of Irganox ™ 1010 and 10 kg of Licowax ™ C was heated to 160 ° C while stirring with a paddle stirrer at a speed of 500 rpm, after which 686 kg of MDI was added. After reaching the maximum reaction temperature, stirring was continued for 30 seconds, after which 125 kg of BDO and 80 kg of Cyagard ™ RF-1243 were added. The mixture was then stirred for 100 s, after which the TPU was poured out. Finally, the material was post-treated at 80 ° C for 30 minutes.

The finished TPU was cut, granulated and processed with the addition of 5% masterbatch black at a temperature of 180 to 200 ° C to a 100 micron blown film.

The carrier film was subjected to a one-sided flame treatment and, after 10 days of storage, coated with Acronal DS 3458 by means of a roll applicator at 50 m / min. The temperature load on the carrier was reduced by a cooled counterpressure roller. The application was about 35 g / m ² . A suitable cross-linking was achieved in-line before winding by irradiation with a UV system equipped with 6 medium-pressure Hg lamps at 120 W / cm. The irradiated web was wound into bars of 33 m in length on a 1 1/4 inch core (31 mm). The cutting was done by cutting off the rods by means of a fixed blade (straight knife) in 25 mm wide rolls.

Example 3 A mixture of 1000 kg of Terathane ™ 1000, 119 kg of BDO, 23 kg of Levagard ™ 4090N, 6 kg of Irganox ™ 1010, 9 kg of Licowax ™ C and 30 kg of Disflamoll ™ DPK was heated to 160 with a paddle at a speed of 500 rpm ° C heated, after which 615 g of MDI was added. The mixture was then stirred for 110 s, after which the TPU was poured out. Finally, the material was post-treated at 80 ° C for 30 minutes.

The finished TPU was cut, granulated and shaped with the addition of 5% by weight of a black batch and 5% by weight of a hydrolysis protective masterbatch KE 9463 in the cast process (flat die with chill roll) to form a 70 μm thick film.

One side was coated with a primer of 5 parts MDI, 45 parts natural rubber and 50 parts of cyclo rubber at 0.6 g / m ² and dried. The adhesive coating was applied directly to the primer layer by means of a comma bar with a coating weight of 18 g / m ² (based on dry matter). The adhesive consisted of a solution of a natural rubber adhesive in n-hexane with a solids content of 30 percent by weight. This consisted of 50 parts of natural rubber, 10 parts of zinc oxide, 3 parts of rosin, 6 parts of alkylphenol resin, 17 parts of terpene phenolic resin, 12 parts of poly-β-pinene resin, 1 part of Irganox 1076 antioxidant and 2 parts of mineral oil. The drying of the coat was carried out in a drying tunnel at 100 ° C. The film was cut immediately behind it in a compound cutting machine with a knife bar with sharp blades spaced 19 mm from rolls on standard 3 inch (3 inch) adhesive tape cores. A part of the rolls was then punched on both sides about 0.2 mm deep, the resulting cuts were radial (perpendicular to the film webs), which significantly improves the hand tearability (these roles are Example 3a).

Comparative Example 1

The winding tape was produced analogously to Example 1, but the TPU film consisted of T-8375 (thermoplastic polyester polyurethane with Shore A hardness of 75 from DIC Bayer Polymer). At the same processing temperature, the melt adhered so strongly to the calender rolls that no film could be produced. After lowering the temperature to 160 ° C, a film could be removed. The T-8375 was chosen as it was for the examples of JP 2005 264 1 12 A (adhesive tape Copolyamide modified with TPU and a blended flame retardant based on nitrogen) was used.

Comparative Example 2

The preparation of the winding tape should be carried out analogously to Comparative Example 1, the TPU FoNe should, however, from 100 phr T-8375 and 10 phr Reofos 65 (isopropylated triaryl phosphate from Great Lakes) as a non-incorporated phosphorus-containing flame retardant. Because of very strong sticking to the calender rolls, however, it was not possible to obtain a film despite varying the processing conditions. The film could not be processed in the blowing process analogous to Example 2 because of lack of melt strength. Only with the casting process analogous to Example 3 was it possible to produce a colorless film 80 μm thick. These were then coated analogously to Example 1 with pressure-sensitive adhesive.

Comparative Example 3

The production of the winding tape was carried out analogously to Example 1, the TPU film corresponded in its composition but the example 2 of JP 2005 264 112 A:

• 40 phr T-8375,

60 phr of CM6541X3 (copolyamide of ε-aminocaproic acid and ω-aminolauric acid with crystallite melting point 133 ° C from Toray Industries), 10 phr of hydrazodicarbonamide,

• 40 phr melamine cyanurate,

• 1 phr Licowax ™ OP,

• 10 phr calcium carbonate.

At a processing temperature similar to Example 1, the melt adhered to the calender rolls. It had bubbles and holes (presumably by decomposition of the hydrazodicarbonamide), after lowering the temperature to 160 to 170 ° C, a film could be produced. However, the thickness was similar to Example 1 80 microns instead of 0.2 mm as in Japanese writing. Comparative Example 4

For coating, a conventional film for insulating tape of Singapore Plastic Products Pte. used under the name F2104S. According to the manufacturer, the film contained about 100 phr (parts per hundred resin) suspension PVC with a K value of 63 to 65, 43 phr DOP (di-2-ethylhexyl phthalate), 5 phr tribasic lead sulphate (TLB, stabilizer), 25 phr ground chalk (Bukit Batu Murah Malaysia with fatty acid coating), 1 phr Furnaceruß and 0.3 phr stearic acid (lubricant). The nominal thickness was 100 μm and the surface was smooth but dull.

On the one hand, the primer Y01 was applied by Four Pillars Enterprise / Taiwan (analytically acrylate-modified SBR rubber in toluene) and thereon 23 g / m ^{2 of} the adhesive IV9 from Four Pillars Enterprise / Taiwan (analytically detectable major component: SBR and natural rubber, terpene resin and alkylphenol resin in toluene). The film was cut into rolls immediately after the dryer with a knife bar with sharp blades at a distance of 25 mm in an automatic machine.

Properties of Examples and Comparative Examples

ND = not determined, P = passed, NP = not passed

* on blade-cut patterns

# The tear strength is below the maximum force

summary of results

In Comparative Example 2, the phosphate plasticizer deteriorates the fogging values and the bond strengths. Comparative Example 3 behaves similarly, presumably the very soft TPU (Shore A = 75) contains a plasticizer.

The tear strengths are acceptable in all cases. The elongations at break of the comparative examples are relatively high, so that hand tearability is worsened in two cases.

The Comparative Examples are too soft in two cases for wrapping applications.

The heat resistance at 140 ° C is poor in all comparative examples, it is probably due to lack of antioxidant and possibly also on the susceptibility to hydrolysis. The non-given short-term heat resistance at 170 ° C is in addition to lack of oxidative resistance (in part cracking) at too low a melting point (all samples are at least melted at the edges). Comparative Example 4 fails because of plasticizer evaporation.

Hydrolysis resistance is inadequate in all of the comparative examples except for the PVC tape, which is not surprising to those skilled in the TPU with polyester polyol.

Some of the comparative examples have low flame resistance (samples completely burned off).

The color is consistently fine, only in Comparative Example 3 do the fillers produce haze (ie, gray coloration).

Claims

claims

1. Halogen-free flame-retardant winding tape with a film of thermoplastic polyurethane, characterized in that a flame retardant based on phosphorus is chemically incorporated.

2. winding tape according to claim 1, characterized in that at least on one side of the carrier film, an adhesive, preferably PSA is present.

3. winding tape according to claim 1 or 2, characterized in that the winding tape is colored.

4. winding tape according to at least one of claims 1 to 3, characterized in that under the test conditions mentioned in the FMVSS 302 or ASTM D 568 self-extinguishing and / or a breakdown voltage of at least 4 kV.

5. winding tape according to at least one of the preceding claims, characterized in that the thickness of the film is 30 to 180 microns, preferably 50 to 150 .mu.m, more preferably 55 to 100 microns, the force in the machine direction at 10% elongation a value of 2 to 20 N / cm, especially 4 to 11 N / cm, the force at 50% elongation has a value of 3 to 25 N / cm, especially 6 to 17 N / cm and / or the breaking force is greater than 10 N / cm and preferably greater than 20 N / cm.

6. winding tape according to at least one of the preceding claims, characterized in that the elongation at break after 312 hours of storage at 140 ° C is at least 100% and / or after 30 min storage at 170 ° C during winding with at least 3 turns and 50th % overlap around a mandrel of 10 mm diameter no damage can be observed.

7. winding tape according to at least one of the preceding claims, characterized in that the Shore D hardness of the polyurethane is at least 35 preferably at least 50 and / or the crystallite melting point of the polyurethane at least 158, preferably at least 170 ° C.

8. winding tape according to at least one of the preceding claims, characterized in that the adhesive is a solvent-free PSA, which is produced by coextrusion, melt coating or dispersion coating, preferably a pressure-sensitive adhesive or dispersion adhesive polyacrylate-based.

9. winding tape according to at least one of the preceding claims, characterized in that the amount of the adhesive layer 10 to 40 g / m ² , preferably 18 to 28 g / m ² , the bond strength of the winding tape on steel 1, 5 to 3 N / cm , the unwind force of the winding tape 1, 2 to 6.0 N / cm at 300 mm / min

Unwinding speed, preferably 1, 6 to 4.0 N / cm, more preferably 1, 8 to 2.5 N / cm and / or the holding power of the winding tape is more than 150 min.

10. winding tape according to at least one of the preceding claims, characterized in that the hand tearability is increased by additives in the film or by mechanical damage to the side edge (s) of the film.

1 1. winding tape according to at least one of the preceding claims, characterized in that the polyurethane of the carrier film

A) at least one organic diisocyanate and B) at least one polyol having an average of at least 1, 8 and at most 3.0 Zerewitinoff-active hydrogen atoms and a number average molecular weight M _n of 450 to 10,000 daltons with

D) at least one organic phosphorus-containing compound based

Phosphonate and / or phosphine oxide having an average of at least 1, 5 and at most 3.0 Zerewitinoff-active hydrogen atoms and a number average molecular weight M _n of 60 to 10,000 daltons in an amount of 1 to 15 wt .-%, based on the TPU,

which has the following structural formula

With

R ¹ , R ² branched or unbranched alkylene radicals having 1 to 24 carbon atoms, substituted or unsubstituted arylene radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkylene radicals having 6 to 30 carbon atoms, substituted or unsubstituted Alkarylene radicals having 6 to 30 carbon atoms, where R ¹ and R ^{2 may be} identical or different,

x, y = 1 to 50 or which has the following structural formula

With

R ¹ H, branched or unbranched alkyl radicals having 1 to 24 carbon atoms, substituted or unsubstituted aryl radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkyl radicals having 6 to 30 carbon atoms, substituted or unsubstituted alkaryl radicals with 6 to 30 carbon atoms,

R ² , R ³ branched or unbranched alkylene radicals having 1 to 24 carbon atoms, substituted or unsubstituted arylene radicals having 6 to 20 carbon atoms, substituted or unsubstituted aralkylene radicals having 6 to 30 carbon atoms, substituted or unsubstituted Alkarylene radicals having 6 to 30 carbon atoms, where R ² and R ^{3 may be} identical or different,

optionally using

and or

wherein the index (formed from the multiplied by 100 quotient of the equivalence ratios of the isocyanate groups of (A) and the sum of the Zerewitinoff-active hydrogen atoms of the compounds (B), (C) and (D) is 85 to 120, optionally using a catalyst (E), preferably in the prepolymer process

will be produced.

12. winding tape according to at least one of the preceding claims, characterized in that the components (B) and (C) of component (D) are different.

13. winding tape according to at least one of the preceding claims, characterized in that the relative amounts of the compounds (B), (C) and (D) are selected so that the ratio of the sum of the isocyanate groups in (A) to the sum of the Zerewitinoffaktiven Is hydrogen atoms in (B), (C) and (D) 0.85: 1 to 1, 2: 1, preferably 0.95: 1 to 1, 1: 1.

14. wrapping tape according to at least one of the preceding claims, characterized in that the isocyanate (A) 4,4'-diphenylmethane diisocyanate, the polyol (B) is a hydroxyl-containing polymerization of the

Tetrahydrofuran and / or the chain extender (C) is 1,4-butanediol.

15. wrapping tape according to at least one of the preceding claims, characterized in that the polyurethane film contains at least 1, preferably at least 2 phr stabilizers against oxidation and / or hydrolysis.

16. wrapping tape according to at least one of the preceding claims, characterized in that as stabilizers, a combination of primary antioxidants such as sterically hindered phenols or C-radical scavengers and secondary antioxidants such as sulfur compounds, phosphites or hindered amines are used, the two functions in one Molecule can be united.

17. wrapping tape according to at least one of the preceding claims, characterized in that the content of phosphorus-free plasticizer in the film at 0 to 5 phr, preferably 0 phr, the content of phosphorus-containing plasticizer in the film at 0 to 10 phr, preferably 0 phr and / or the fogging value more than 90%. is.

18. Use of a winding tape according to at least one of the preceding claims for bundling, protecting, marking, insulating or sealing of ventilation pipes, wires or cables or for sheathing of cable harnesses in vehicles or field coils for picture tubes.