EP0761859B1 - Textile laminate, process for its manufacture, its use and hybrid yarns containing webs - Google Patents

Description

The invention relates to a textile composite material which is particularly suitable as a carrier insert for the production of roofing membranes or as a tarpaulin or surface.

Textile composites for the production of roofing membranes must meet a wide range of requirements. On the one hand, sufficient mechanical stability is required, such as good perforation resistance and good tensile strength, for example to withstand the mechanical loads during further processing, such as bituminization or laying. In addition, a high resistance to thermal stress, for example when bituminizing or to radiant heat, and resistance to flying flames are required. There has been no shortage of attempts to improve existing textile composites.

It is already known, for example, to combine composites based on synthetic fiber nonwovens with reinforcing fibers, for example with glass fibers. Examples of such sealing sheets can be found in GB-A-1,517,595, DE-Gbm-77-39,489, EP-A-160,609, EP-A-176,847, EP-A-403,403 and EP-A-530,769. According to this state of the art, the connection between the nonwoven fabric and the reinforcing fibers takes place either by gluing by means of a binder or by needling the layers of different materials.

It is also known to produce composites by knitting or sewing techniques. Examples of these can be found in DE-A-3,347,280, US-A-4,472,086, EP-A-333,602 and EP-A-395,548.

DE-A-3,417,517 discloses a textile interlining material with anisotropic properties and a process for its production. The interlining consists of a substrate with a surface melting below 150 ° C, and therefore connected reinforcement filaments melting at 180 ° C, which are fixed on this surface parallel to each other. According to one embodiment, the substrate can be a nonwoven fabric, on one surface of which there are hot-melt adhesive fibers or threads, which are provided for producing an adhesive bond of the reinforcing fibers arranged in parallel with the nonwoven fabric.

DE-A-3,941,189 also discloses a combination of reinforcing fibers in the form of a thread chain with nonwovens based on synthetic fibers, which can be connected to one another in a wide variety of ways, including through the use of adhesive fibers. The composites described, like the interlinings known from DE-A-3,417,517, show anisotropic properties.

A combination of reinforcing fibers in the form of bicomponent fibers with nonwovens based on synthetic fibers is known from US Pat. No. 4,504,539.

EP-A-0,281,643 discloses a combination of reinforcing fibers in the form of a network of bicomponent fibers with nonwovens based on synthetic fibers, the weight fraction of the network of bicomponent fibers being at least 15% by weight.

From JP-A-81-5879 a composite is known which is provided with a mesh-like reinforcing material. Mixed yarns are not used.

EP 0 138 294 A2 describes the production of blended yarns which consist of the components graphite, glass, aluminum, steel etc. and of thermoplastic fibers consist. A single yarn is made from these components. These yarns are processed into textile fabrics, for example by weaving. Graphite threads and synthetic threads can also be woven together. The production of a textile fabric on the one hand and the subsequent reinforcement with hybrid yarns is not disclosed there.

EP 0 717 133 A2 describes the production of hybrid yarns which consist of a type of filament with a lower heat shrinkage (type A) and a type with a higher heat shrinkage (type B) than the other filaments of the hybrid yarn. These hybrid yarns can be processed into textile fabrics such as woven fabrics, knitted fabrics, knitted fabrics or also stabilized scrims. This European patent application does not contain any teaching on how to combine hybrid yarns with an already finished textile fabric.

There is still a need for reinforced laminates which are characterized by increased strength and which are particularly suitable as carrier materials for the production of bituminized roofing or waterproofing membranes which have improved resistance to thermal stress during bituminization and are distinguished by good flame resistance , excellent mechanical properties, such as. B. have high tensile strengths, and their weight-related additional strength is significantly higher than the values of corresponding conventional carrier materials.

Furthermore, it has been shown in the practical implementation of the connection of nonwovens with textile fabrics that damage to the individual fibers generally occurs when the layers are needled, so that the composite does not have optimal strength. Problems can also arise when bonding nonwovens to flat structures, for example by calendering the composite that has not yet solidified. It has been found that the individual layers can be damaged by the pressure exerted during calendering, so that these connections also do not have optimal strength.

There was therefore still the task of developing laminates with improved strength, which no longer have the disadvantages described above and which are particularly suitable as carrier materials for the production of roofing or sealing sheets with the desired advantages. In addition, there was the task of finding a carrier material in which the reinforcing fibers can be connected to the nonwoven fabric without additional binders.

The present invention relates to a composite material according to claim 1. Further objects of the invention can be found in claims 2 to 28.

The term "fibers" is to be understood in its broadest meaning within the scope of this description. This includes both fibers of limited length (staple fibers) and the yarns made from them, as well as continuous fibers, so-called filaments, which are in the form of a monofilament, preferably in the form of multifilament yarns.

The term “textile fabric” is also to be understood in its broadest meaning within the scope of this description. These can be all structures made of fibers from synthesized polymers or from inorganic fibers that have been produced using a surface-forming technique.

Examples of such textile fabrics are woven fabrics, laid fabrics, knitted fabrics and knitted fabrics, and preferably nonwovens.

Of the nonwovens made of fibers from synthetic polymers, spunbonded fabrics, so-called spunbonds, which are produced by randomly depositing freshly melt-spun filaments are preferred. They consist of continuous synthetic fibers made of melt-spinnable polymer materials. Suitable polymer materials are, for example, polyamides, such as. B. polyhexamethylene diadipamide, polycaprolactam, aromatic or partially aromatic polyamides ("aramids"), partially aromatic or fully aromatic polyesters, polyphenylene sulfide (PPS), polymers with ether and keto groups, such as. B. polyether ketones (PEK) and polyether ether ketone (PEEK), or polybenzimidazoles.

The spunbonded fabrics preferably consist of melt-spinnable polyesters. In principle, all known types suitable for fiber production come into consideration as polyester material. Such polyesters consist predominantly of building blocks which are derived from aromatic dicarboxylic acids and from aliphatic diols. Common aromatic dicarboxylic acid building blocks are the divalent residues of benzenedicarboxylic acids, especially terephthalic acid and isophthalic acid; Common diols have 2 to 4 carbon atoms, with the ethylene glycol being particularly suitable. Composites according to the invention are particularly advantageous, the nonwovens of which consist of a polyester material which consists of at least 85 mol% of polyethylene terephthalate. The remaining 15 mol% then build up from dicarboxylic acid units and glycol units, which act as so-called modifying agents and which allow the person skilled in the art to specifically influence the physical and chemical properties of the filaments produced. Examples of such dicarboxylic acid units are residues of isophthalic acid or of aliphatic dicarboxylic acid such as. B. glutaric acid, adipic acid, sebacic acid; Examples of diol residues with a modifying action are those of longer-chain diols, e.g. B. of propanediol or butanediol, of di- or triethylene glycol or, if present in small quantities, of polyglycol with a molecular weight of about 500 to 2000.

Polyesters which contain at least 95 mol% of polyethylene terephthalate (PET), in particular those made of unmodified PET, are particularly preferred.

If the composites according to the invention are also intended to have a flame-retardant effect, they particularly advantageously comprise spunbonded nonwovens which have been spun from flame-retardant modified polyesters. Such flame-retardant modified polyesters are known. They contain additives of halogen compounds, in particular bromine compounds, or, which is particularly advantageous, they contain phosphonic compounds which are condensed into the polyester chain.

Particularly preferred, flame-retardant laminates according to the invention contain spunbonded nonwovens made of polyesters, which in the chain are components of the formula wherein R is alkylene or polymethylene with 2 to 6 carbon atoms or phenyl and R ^{1 is} alkyl with 1 to 6 carbon atoms, aryl or aralkyl, contained in condensed form. In the formula (I), R is preferably ethylene and R ^{1 is} methyl, ethyl, phenyl, or o-, m- or p-methylphenyl, in particular methyl. Such spunbonded fabrics are used, for. B. described in DE-A-39 40 713.

The polyesters contained in the nonwovens have a molecular weight corresponding to an intrinsic viscosity (IV), measured in a solution of 1 g of polymer in 100 ml of dichloroacetic acid at 25 ° C., from 0.7 to 1.4.

The textile fabrics made of fibers made of synthetic polymers for producing the composites according to the invention have customary weights per unit area of 20 to 400 g / m ² , preferably 40 to 150 g / m ² .

The spunbonded webs are usually subjected to chemical or thermal and / or mechanical pre-consolidation in a known manner after their production.

In a further embodiment of the invention, the textile fabric made of fibers made of synthetic polymers can also be a non-woven fabric bonded with a melt binder, which contains carrier and hot-melt adhesive fibers. The carrier and hot-melt adhesive fibers can be derived from any thermoplastic thread-forming polymer. Carrier fibers can also be derived from non-melting thread-forming polymers.

Examples of polymers from which the carrier fibers can be derived are polyacrylonitrile, polyolefins, such as polyethylene, essentially aliphatic polyamides, such as nylon 6.6, essentially aromatic polyamides (aramids), such as poly (p-phenylene terephthalate) or copolymers containing a proportion on aromatic m-diamine units to improve solubility or poly (mphenylene isophthalate), essentially aromatic polyesters, such as poly (phyroxybenzoate) or preferably essentially aliphatic polyesters, such as polyethylene terephthalate.

The proportion of the two types of fibers to one another can be chosen within wide limits, it being important to ensure that the proportion of the hot melt adhesive fibers is chosen so high that the nonwoven fabric is given sufficient strength for the desired application by bonding the carrier fibers to the hot melt adhesive fibers. The proportion of the hot melt adhesive originating from the hot melt adhesive fiber in the nonwoven fabric is usually less than 50% by weight, based on the weight of the nonwoven fabric.

Modified polyesters with a melting point which is lowered by 10 to 50 ° C., preferably 30 to 50 ° C., compared to the nonwoven raw material, are particularly suitable as hot melt adhesives. Examples of such a hot melt adhesive are polypropylene, polybutylene terephthalate or by condensing in longer-chain diols and / or isophthalic acid or aliphatic dicarboxylic acids modified polyethylene terephthalate.

The hot melt adhesives are preferably introduced into the nonwovens in fiber form.

Carrier and hot-melt adhesive fibers are preferably constructed from one polymer class. This means that all fibers used are selected from a class of substances so that they can be easily recycled after the fleece has been used. If the carrier fibers are made of polyester, for example, the hot-melt adhesive fibers are also made of polyester or a mixture of polyesters, e.g. B. selected as a bicomponent fiber with PET in the core and a lower melting polyethylene terephthalate copolymer as a sheath.

The individual fiber titers of the carrier and hot melt adhesive fibers can be selected within wide limits. Examples of common titer ranges are 1 to 16 dtex, preferably 2 to 6 dtex.

If composites according to the invention with flame-retardant properties are additionally bound, they preferably contain flame-retardant hotmelt adhesives. As a flame retardant hot melt adhesive z. B. a modified by incorporation of chain links of the formula (I) indicated polyethylene terephthalate in the laminate according to the invention.

The filaments or staple fibers making up the nonwovens can have a practically round cross section or can also have other shapes, such as dumbbell, kidney-shaped, triangular or tri or multilobal cross sections. Hollow fibers can also be used. Furthermore, the hot-melt adhesive fiber can also be used in the form of bi- or multicomponent fibers.

The fibers forming the textile fabric can be modified by conventional additives, for example by antistatic agents such as carbon black.

These textile fabrics described above are used in accordance with the invention Hybrid yarns reinforced. These hybrid yarns contain reinforcing fibers and deep-melting binding fibers, which can be in the form of endless filaments or as staple fibers of finite length. The hybrid yarns are preferably in the form of a textile fabric or as a warp thread group. It is particularly advantageous to use the hybrid yarns in the form of a scrim, which consist of hybrid yarns at least in one direction. Such fabrics are also the subject of the present invention.

The hybrid yarns can consist of reinforcing and binding fibers from the same or different chemical classes.

In one embodiment, for example, the reinforcing fiber can be constructed from individual filaments that have an initial modulus of more than 50 GPa, and the binding fiber can be constructed from individual filaments made of deep-melting thermoplastic material.

Preferred reinforcing fibers in this embodiment consist of glass, carbon or aramid.

In a further embodiment, reinforcing and binding fibers consist of polymeric materials, preferably of polymeric materials from one polymer class, in particular from the same polymer class as the fibers that make up the textile fabric.

In this embodiment, the individual filaments of the reinforcing fibers have an initial modulus of more than 10 GPa. Reinforcing fibers for this embodiment consist, for example, of polyphenylene sulfide (PPS), polyether ether ketone (PEEK) or polyether imide (PEI).

Preferred reinforcing fibers for this embodiment are high-strength and low-shrink polyester fibers.

Binder fibers in the reinforcing threads to be used according to the invention consist of thermoplastic polymer materials, the melting point of which lies below the thermoplastic material contained in the textile fabric. Examples of such polymer materials are preferably polyolefins or modified polyesters which have a lower melting point than the unmodified polyester. Examples of polyolefins are polyethylene or polypropylene. Examples of modified polyesters are the types of polybutylene terephthalate already mentioned, and polyethylene terephthalate modified by the condensation of longer-chain diols and / or isophthalic acid or aliphatic dicarboxylic acids.

The hybrid games are preferably produced from reinforcing and binding fibers of the first embodiment described above by means of a special warm intermingling process, which is described in EP-B-0,455,193. In order to avoid filament breaks during swirling, the filaments are warmed up to near the softening point before swirling (approx. 600 ° C for glass). The heating can be carried out by means of godets and / or heating pipes, while the low-melting thermoplastic individual filaments are fed to the superordinate intermingling nozzle without preheating. This smooth hybrid game with a high thread closure is easily weave-compatible.

Suitable hybrid games include a. Game of type 68 tex glass / 420 dtex PET.

The hybrid games of the second embodiment described above are produced using conventional swirling techniques, for example intermingling or commingling techniques. As already stated, the hybrid yarns are preferably used in the form of a scrim, which are also the subject of the present invention.

The thread density of the scrims according to the invention can vary within wide limits depending on the desired property profile. On the one hand, the thread densities can be the same in all directions; On the other hand, the scrims can have a thread density between 0.5, for example in the direction of the hybrid game and 10 threads per cm and in the other direction a thread density between 0.5 and 1 thread / cm. The thread density is measured perpendicular to the respective thread running direction, the thread density being the same for all existing thread groups, or different thread densities can be selected depending on the expected load.

Depending on the desired requirement profile, the hybrid yarns can have a wide range of maximum tensile strength expansions, for example from about 2.5 to 25%.

The fineness-related strength of the hybrid game can be selected within wide limits depending on the desired requirement profile, for example in the range from 20 to 150 cN / tex.

The titer of the hybrid yarns in the composite is advantageously 30 to 3000 dtex.

In the sense of the invention, laid scrims are thread grids which are formed from parallel sets of threads lying at an angle to one another, the threads being fixed to one another at their crossing points and at least one set of threads containing hybrid yarns.

The threads are preferably fixed at their crossing points by melting or melting on the binding fibers, in particular without the use of further adhesives. In a preferred embodiment, the threads are fixed at their crossing points by partially melting the binding fibers, so that the majority of the binding fibers retain their fiber shape. This embodiment allows the hot melt adhesive to be distributed as uniformly as possible when the composite is subsequently formed.

The angle at which the sheets of thread cross is usually between 10 ° and 90 °. A clutch can of course contain more than just two sets of threads. The number and direction of the thread sheets depends on any special requirements.

Non-woven fabrics are preferred which consist of two sets of threads crossing at an angle of preferably 90 °. Is a particularly high mechanical stability in one direction, e.g. B. the longitudinal direction of the layered fabric required, it is recommended to install a scrim that has a thread family in the longitudinal direction with a smaller thread spacing, the z. B. is stabilized by a transverse thread sheet or by two thread sheets that form with the first angle of approximately + 40 ° to + 70 ° or - 40 ° to - 70 °.

Special stability requirements in all directions can be met by a scrim with 4 or 5 sets of threads, which lie on top of each other in different directions and are connected to each other at the thread crossing points. An example of such a special scrim is shown in EP-A-572,891.

The composites according to the invention are usually produced by separate production of the individual layers, subsequent combination of these layers and subsequent adhesive bonding of the layer by heating, if appropriate using pressure, so that the low-melting thermoplastic filaments of the binding fibers melt or melt and adhere to the adjacent surface of the textile fabric made of fibers from synthetic polymers form a connection.

The composites according to the invention show no tendency to delamination and no formation of waves and cracks, even under high thermal mechanical stress.

The bituminizers of the composites according to the invention show a surprisingly small increase in width compared to conventional webs.

Furthermore, it can be seen that even with rough bituminizing conditions, flat, area-stable, bubble-free bitumen sheets are obtained with the composite material according to the invention. Furthermore, the puncture resistance increases, as in the Stamp puncture test according to DIN 54307 shows. This results in significantly improved workability and increased work safety when laying the bituminized roofing membrane according to the invention on the roof.

A composite of nonwoven / laid fabric / nonwoven is advantageously used.

The composites according to the invention can be used for the production of bituminized roofing and waterproofing membranes. This is also an object of the present invention. For this purpose, the carrier material is treated with bitumen in a manner known per se and then optionally sprinkled with a granular material, for example with sand. The roofing and waterproofing membranes produced in this way are easy to process.

• a) Herstellung eines textilen Flächengebildes in an sich bekannte Weise,
• b) Zuführen von Hybridgam auf eine gemäß a) erhaltene Oberfläche des textilen Flächengebildes,
• c) gegebenenfalls Zuführen eines weiteren textilen Flächengebildes auf die andere Seite des Hybridgams, und
• d) Ausüben von erhöhter Temperatur und/oder Druck, so daß das tieferschmelzende Bindefilament des Hybridgams an- oder aufschmilzt und sich eine Klebeschicht zwischen den Flächengebilden ausbildet und der Verbundstoff seine Endverfestigung erfährt.

The production of the composite according to the invention comprises the measures:

• a) production of a textile fabric in a manner known per se,
• b) supplying hybrid yarn to a surface of the textile fabric obtained according to a),
• c) optionally feeding a further textile fabric to the other side of the hybrid chamois, and
• d) Exerting elevated temperature and / or pressure, so that the deep-melting binding filament of the hybrid chamois melts or melts and an adhesive layer forms between the flat structures and the composite undergoes its final consolidation.

The production of the composite material according to the invention is explained below using the example of a spunbonded nonwoven as a textile fabric.

Spunbonding is carried out by means of spinning apparatus known per se. For this purpose, the melted polymer is alternately fed with polymers, which form the carrier fiber and the hot-melt adhesive fibers, through a plurality of rows of spinnerets or groups of spinneret rows connected in series. The spun polymer streams are stretched in a conventional manner and z. B. using a rotating baffle in scattering texture on a Conveyor belt put down.

The primary fleece produced in this way is then thermally pre-consolidated in a manner known per se by z. B. is treated in a pre-consolidation device with a hot roller, so that at least part of the hot melt adhesive fibers that may be present melts, whereby the primary fleece solidifies to the extent that it can be handled without the conveyor belt. This type of pre-consolidation is e.g. B. described in DE-PS-3,322,936. The scrim of yarns, which consists of hybrid yarn in at least one yarn direction, is then applied to the surface of the primary nonwoven obtained. Subsequently, the lower-melting binding filament contained in the hybrid yarn is melted or melted on by the action of elevated temperature and / or pressure, so that an adhesive layer forms between the two flat structures and the composite undergoes its final consolidation. The hybrid chamois can be fed in the form of a scrim on one or both sides. Instead of two nonwovens, a nonwoven can be added to the combination nonwoven / nonwoven. The finished laminate is then wound up in a manner known per se.

The method described above can be varied in many ways without departing from the basic idea of the present invention. For example, different sequences of carrier and hot-melt adhesive polymers can be specified and thus differently layered spunbonded nonwovens can be produced. Instead of the fabric, a laminate of nonwoven fabric and fabric applied on one side can also be provided, so that a sandwich structure is created. Furthermore, several alternating layers [fleece (laid fleece) _x ] can be combined to form a sandwich construction. It is also readily possible to use more than two types of polymers in the production of the nonwoven or to use the hot-melt adhesive fibers in the form of bicomponent or multicomponent fibers. Furthermore, the described method can also be carried out in separate steps by z. B. is interrupted after the final consolidation of the spunbonded fabric and the combination with the flat structure and an adhesive bonding of the layers is carried out in a separate operation.

The following examples illustrate the invention without restricting it.

Examples 1-7

Composites of spunbonded nonwoven with fabrics containing various blended yarns were produced and investigated.

Spunbonded nonwovens based on polyethylene terephthalate filaments were produced in a spundbond line. Type A had a weight per unit area of 60 g / m ² , a tensile force of 13.0 daN / tex per 5 cm width and a maximum tensile force elongation of 24.5%; Type B had a basis weight of 60 g / m ² , a tensile force of 15.7 daN / 5 cm width and a maximum tensile force elongation of 15.7%. Different fabrics, the structure of which can be seen in the table below, were added to the primary fleece. The laminate obtained was processed by calendering to give a composite according to the invention. Manufacturing conditions and properties of the products obtained are shown in the table below.

Claims (28)

1. Laminate comprising on the one hand at least one separately manufactured fabric made of fibres from synthetic polymers, and on the other hand hybrid yam combined with this fabric, which yarn is composed of reinforcing fibres and low melting binding fibres.
2. Laminate according to claim 1, characterised in that the fabric is a non-woven fabric, particularly a spin-bonded fabric from filaments.
3. Laminate according to claim 1, characterised in that the fabric contains polyester fibres, particularly polyethylene terephthalate fibres.
4. Laminate according to claim 1, characterised in that the fabric exhibits flame retarding properties.
5. Laminate according to claim 1, characterised in that the fabric has a weight per unit area of 20 to 400 g/m².
6. Laminate according to claim 1, characterised in that the fabric is a melt binder-bonded non-woven fabric.
7. Laminate according to claim 1, characterised in that the hybrid yarn is composed of filaments.
8. Laminate according to claim 1, characterised in that the individual filaments of the reinforcing fibres exhibit an initial modulus of over 50 GPa.
9. Laminate according to claim 8, characterised in that the reinforcing fibres contain glass, carbon and/or aramide fibres.
10. Laminate according to claim 1, characterised in that the hybrid yarns consist of polymeric materials.
11. Laminate according to claim 10, characterised in that the reinforcing fibres consist of polyester, preferably of polyethylene terephthalate.
12. Laminate according to claim 11, characterised in that the hybrid yarns consist of polymeric materials of the same chemical class of substances.
13. Laminate according to claim 1, characterised in that the hybrid yarn is present in the form of warp yarn sheet.
14. Laminate according to claim 1, characterised in that the hybrid yarn is present in the form of a web.
15. Laminate according to claim 1, characterised in that the hybrid yarn is present in the form of a fabric.
16. Laminate according to claim 13, characterised in that the warp yarn sheet exhibits a thread density of between 0.5 and 10 threads per cm.
17. Laminate according to claim 14, characterised in that the web exhibits a thread density of between 0.5 and 10 threads per cm.
18. Method for manufacturing a laminate according to claim 1, comprising the following operations:

    a) manufacture of a laminate by a known method;

    b) feeding hybrid yarn to a surface of the fabric obtained according to a)

    c) if necessary, feeding a further fabric to the other side of the hybrid yarn, and

    d) exerting increased temperature and/or pressure, so that the lower melting binding filament of the hybrid yarn is melted on, so that an adhesive layer is formed between the fabrics and the laminate undergoes its final hardening.
19. Method according to claim 18, characterised in that the hybrid yarns are added in the form of a web which at least in one direction contains hybrid yarns from reinforcing and binding fibres.
20. Method according to claim 19, characterised in that the binding fibres are partially melted on and harden the web at the points of intersection of the yarn sheets forming the web.
21. Method according to claim 19, characterised in that the reinforcing and binding fibres consist of filaments.
22. Method according to claim 21, characterised in that the individual filaments of the reinforcing fibres exhibit an initial modulus of over 50 GPa.
23. Method according to claim 22, characterised in that the reinforcing fibres contain glass-, carbon- and/or aramide fibres.
24. Method according to claim 19, characterised in that the reinforcing fibres and the binding fibres consist of polymeric materials.
25. Method according to claim 24, characterised in that the reinforcing fibres consist of polyester, preferably of polyethylene terephthalate.
26. Method according to claim 25, characterised in that reinforcing and binding fibres consist of polymeric materials of one chemical substance class.
27. Method according to claim 19, characterised in that the web exhibits a thread density of between 0.5 and 10 threads per cm.
28. Use of the laminate according to claim 1 for manufacturing bituminised roof and waterproof sheeting.