EP0801159B1 - Low-shrinking hybrid yarns, method for its production and its use - Google Patents

Description

The present invention relates to new hybrid yarns, which are characterized by a special low thermal shrinkage. Such yarns can be advantageously to composite materials or to textile fabrics, such as Process occasionally.

Hybrid games, i.e. yarns made of reinforcement and matrix filaments, are in themselves known. Such yarns are used, for example, as preliminary products for production of composite materials. This is usually done with a textile Fabric made from the hybrid game; the matrix filaments of this Hybrid games are then created by melting or melting into a matrix transferred, which embeds or flows around the reinforcing filaments and builds the network together with them.

The matrix filaments are generally not subject to high requirements in terms of strength and other mechanical properties, as these are melted anyway in later processing steps. It is therefore no longer necessary an elaborate aftertreatment in the production of such filaments spinning, like stretching or fixing. Show matrix filaments therefore inherently a significant thermal shrinkage, which is in the later processing steps can adversely affect the product.

There is a need for hybrid yarns that have low shrinkage. Such yarns naturally do not shrink or only shrink to a very small extent Dimensions when heated to form the matrix. Consequently, the location of the Reinforcement filaments when generating the matrix, or only insignificantly disturbed. These new games will also be used to make scrims much simplified. Previously, when fixing the superimposed Yarns during the fabric production process are elaborate absorb the shrinkage of the yarn caused by the heating and that Stabilize primary scrims. With the new hybrid yarns, they can Measures largely eliminated.

They are so-called two-component loop yarns with high strength and low shrinkage. Such yarns were especially for the Developed for use as sewing thread and for example in EP-B-363,798 described. However, such yarns usually do not have any Matrix filaments from deep-melting filaments, but are made Filaments of one type but different strengths, in a core-sheath structure are arranged, built.

A process has now been developed for producing low shrinkage hybrid yarns found that leads to products with the property profile described above. The yarns according to the invention are characterized by a relatively large size Temperature interval from very low thermal shrinkage.

The present invention relates to containing low-shrinkage hybrid yarns Reinforcing filaments and matrix filaments made of thermoplastic polymers, the a lower melting point than the melting or decomposition point of the Have reinforcing filaments, and are characterized in that the thermal shrink, at a load of 0.0004 cN / dtex and an air temperature of 160 ° C of less than 2% and at an air temperature of 200 ° C of less than or equal to 5%, in particular less than or equal to Is 3%, and that the static shrinkage force at Temperatures of up to 200 ° C up to 0.01cN / dtex.

To determine the thermal shrinkage of the hybrid yarns according to the invention loops at each end of six yarn samples, each 60 cm long formed and these yarn samples on their loops on a shrink rod hooked. These yarn samples are each weighing one Preload force of 0.0004 cN / dtex exposed. The shrink bar with the Steam samples are suspended in a forced air oven and then for 15 minutes Treated hot air at a defined temperature. The change in length of the yarn sample and after heating in% represents the thermal shrink.

The mechanical properties of the hybrid yarns according to the invention are shown in Dependence of the composition, such as type and proportion of the reinforcing filaments or the matrix filaments depending on the physical structure of the yarn, such as. Degree of turbulence, can be varied within wide limits. Usually is the proportion of the matrix filaments 5 to 60% by weight, preferably 10 to 50% by weight, based on the weight of the hybrid yarn.

The term "hybrid yarn" is at its broadest within the scope of this description Understand meaning. Every combination is therefore included Reinforcement filaments and to understand the matrix filaments defined above.

Examples of possible hybrid yarn types are filament yarns made of different Types of filaments that are intermingled or by another Technology, such as twisting, are combined. All these Hybrid games are characterized by the presence of two or more types of Filaments characterized, with at least one filament type Reinforcing filament and at least one filament type is a matrix filament in the sense of the definitions given above.

Intermingling or commingling techniques are particularly preferred manufactured hybrid yarns; it can be a loop game act, but preferably smooth yarns.

The flat yarns according to the invention are distinguished by a particularly good one Processability with area-forming technologies and good fabric samples out. In an embodiment of the invention, the subject shrinkage is a burden of 0.0004 CN / dtex and a temperature of 160 ° C less than or equal to 2%, in particular less than or equal to 1%.

Five yarn samples of 60 cm each are used to measure the static shrinkage force Length clamped under a preload of 0.01 cN / dtex in two clamps. Then the clamped yarn sample with air of the desired Treated temperature for one minute. When heating in the longitudinal direction of the thread The force occurring is the static shrinkage force and is reached after a short Time interval a saturation value.

The number of swirling points in the hybrid games according to the invention leaves can be set in a wide range by the choice of the swirling conditions. The higher the proportion of the mechanically relatively unstable matrix component, the more the turbulence can be carried out less intensely and consequently the The distance of the interlacing points in such yarns is usually relative large.

Preferred hybrid yarns have a intermingling distance of less than 60 mm, preferably less than 30 mm; this value refers to a Measurement with the Rothschild Entanglement Tester 2050 needle tester.

The matrix filaments of the hybrid yarns according to the invention consist of thermoplastic polymers. These preferably have a melting point, which is at least 30 ° C below the melting or destruction point of each reinforcement filament used.

In those used in the hybrid games according to the invention Reinforcing filaments can be a variety of filaments Trade materials. In addition to organic polymers, inorganic Materials are used. Reinforcement filaments in the sense of this Description mean filaments which are in the desired textile Flat structures or composite material take on a reinforcing function. In a first preferred embodiment, the reinforcement filaments are made of Single filaments built that have an initial module of more than 50 GPa exhibit.

Preferred reinforcing filaments of this type are made of glass; Carbon; Metals or metal alloys, such as steel, aluminum or tungsten; Non-metals, like boron; Metal, semi-metal or non-metal oxides, carbides or nitrides, such as Aluminum oxide, zirconium oxide, boron nitride, boron carbide, silicon carbide, silicon dioxide (Quartz); Ceramics, or high-performance polymers (i.e. fibers that have no or only low stretch a very high initial modulus and a very high one Tensile strength) such as liquid crystalline polyester (LCP), poly (bisbenzimidazo-benzophenanthrolines (BBB), poly (amide imides) (PAI), Polybenzimidazoles (PBI), poly (p-phenylene benzobisoxazoles (PBO), poly (p-phenylene benzobistiazoles) (PBT), polyether ketones (PEK, PEEK, PEEKK), Polyetherimides (PEI), polyether sulfones (PESU), polyimides (PI), poly- (p-phenylenes) (PPP), polyarylene sulfides (PPS), polysulfones (PSU), polyolefins, such as polyethylene (PE) or polypropylene (PP), and aramids (HMA), such as poly- (m-phenylene-isophthalamide), Poly (m-phenylene terephthalamide), poly (p-phenylene isophthalamide), Poly (p-phenylene terephthalamide), or from organic Solvents such as N-methylpyrrolidone, spinnable aramides derived from Terephthalic acid dichloride and a mixture of two or more aromatic Diamines, for example the combination p-phenylenediamine, 1,4-bis (4-aminophenoxy) benzene, 3,3'-dimethylbenzidine, or p-phenylenediamine, 1,4-bis (4-aminophenoxy) benzene, 3,4'-diaminodiphenyl ether, or p-phenylenediamine, m-phenylenediamine, 1,4-bis (4-aminophenoxy) benzene.

Reinforcement filaments made of glass, carbon or are particularly preferred aromatic polyamide.

In a second particularly preferred embodiment, reinforcement and Matrix filaments used, which are made of polymeric materials from a Polymer class, for example from polyolefins, from polyamides or preferably consist of polyesters.

In this embodiment, the single filaments of the reinforcing filaments have an initial modulus of more than 10 GPa. Reinforcement filaments for this Embodiments are preferably high-strength and low-shrinkage Polyester filament yarns, in particular with a yarn count of less than or equal to 1100 dtex, a tenacity greater than or equal to 55 cN / tex, one Maximum tensile strength expansion of greater than or equal to 12% and a hot air shrinkage (measured at 200 ° C) of less than or equal to 9%.

The measurement of the maximum tensile force and the maximum tensile force elongation used upcoming polyester game is based on DIN 53 830, part 1.

Matrix filaments in the hybrid games according to the invention consist of or contain thermoplastic polymers. It can be any melt-spinnable thermoplastics act as long as the manufactured therefrom Melt filaments at a temperature that is lower than the melting or Decomposition temperature of the reinforcing filaments used in the respective case.

Matrix filaments made from polybutylene terephthalate and / or from are preferred Polyethylene terephthalate and / or from chemically modified Polyethylene terephthalate.

Matrix filaments made from a thermoplastic are very particularly preferred modified polyester, especially a modified polyethylene terephthalate used; the modification lowers the melting point in the Comparison with the filament made of unmodified polyester.

Particularly preferred modified polyesters of this type contain the recurring structural units of the formulas I and II -O-OC-Ar ¹ -CO-OR ¹ - -O-OC-R ² -CO-OR ³ - wherein Ar ^{1 represents} a divalent mononuclear or polynuclear aromatic radical, the free valences of which are in the para position or in a parallel or coaxial position with respect to one another, preferably 1,4-phenylene and / or 2,6-naphthylene , R ¹ and R ³ independently of one another represent divalent aliphatic or cycloaliphatic radicals, in particular radicals of the formula -C _n H _2n -, in which n is an integer between 2 and 10, in particular ethylene, or a radical derived from cyclohexanedimethanol, and R ^{2 represents} a divalent aliphatic, cycloaliphatic or mononuclear or polynuclear aromatic radical, the free valences of which are in the meta position or in an angled position comparable to this position, preferably 1,3-phenylene.

Very particularly preferred modified polyesters of this type contain 40 to 95 mol% of the repeating structural units of the formula I and 60 to 5 mol% of the repeating structural units of the formula II, in which Ar ^{1 is} 1,4-phenylene and / or 2,6-naphthylene, R ¹ and R ^{3 are} ethylene and R ^{2 is} 1,3-phenylene.

In a further preferred embodiment, matrix filaments are used Use that consist of a thermoplastic and elastomeric polymer or contain this. It can also be any melt-spinnable and elastomeric thermoplastics act as long as the filaments made from them melt at a temperature that is lower than the melting or Decomposition temperature of the reinforcing filaments used in the respective case.

In the context of this description, a "elastomeric polymer" means a polymer understand whose glass transition temperature is less than 0 ° C, preferably is less than 23 ° C.

Preferred examples of thermoplastic and elastomeric polymers are elastomeric polyamides, polyolefins, polyesters and polyurethanes. Such polymers are known per se.

In the structural formulas defined above, any radicals mean divalent aliphatic radicals, including branched and in particular straight-chain To understand alkylene, for example alkylene with two to twenty, preferably with two to ten carbon atoms. Examples of such radicals are ethane-1,2-diyl, Propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl or octane-1,8-diyl.

If any radicals in the structural formulas defined above mean divalent cycloaliphatic radicals, they are to be understood as meaning groups which contain carbocyclic radicals having five to eight, preferably six, ring carbon atoms. Examples of such radicals are cyclohexane-1,4-diyl or the group -CH ₂ -C ₆ H ₁₀ -CH ₂ -.

In the structural formulas defined above, any radicals mean divalent aromatic residues, these are single- or multi-core aromatic Hydrocarbon radicals or heterocyclic-aromatic radicals, the one or can be multi-core. Show in the case of heterocyclic aromatic radicals these in particular one or two oxygen, nitrogen or sulfur atoms in the aromatic core.

Polynuclear aromatic radicals can be condensed with one another or via C-C bonds or via bridge groups, such as -O-, -S-, -CO- or -CO-NH- groups be connected.

The valence bonds of the divalent aromatic radicals can be in para or are in a comparable coaxial or parallel position to each other, or also in a meta or comparable angular position to each other.

The valence bonds that are in coaxial or parallel position stand, are directed in opposite directions. An example of coaxial, opposite directional bonds are the biphen-4,4'-diyl bonds. An example of parallel, oppositely directed bonds are the naphthalene 1,5 or 2,6 bonds, while the naphthalene-1,8 bonds are rectified in parallel.

Examples of preferred divalent aromatic radicals, their valence bonds in a para- or comparable coaxial or parallel position to each other are mononuclear aromatic radicals with free para to each other Valences, especially 1,4-phenylene or dinuclear fused aromatic Residues with parallel, oppositely directed bonds, in particular 1,4-, 1,5- and 2,6-naphthylene, or dinuclear linked via a C-C bond aromatic residues with coaxial, oppositely directed bonds, especially 4,4'-biphenylene.

Examples of preferred divalent aromatic radicals, their valence bonds are in a meta or comparable angular position to each other mononuclear aromatic residues with meta-constant free valences, in particular 1,3-phenylene or dinuclear condensed aromatic radicals bonds oriented at an angle to one another, in particular 1,6- and 2,7-naphthylene, or dinuclear aromatic residues linked via a C-C bond with angled bonds, in particular 3,4'-biphenyls.

All of these aliphatic, cycloaliphatic or aromatic radicals can with inert groups may be substituted. These are to be understood as substituents which do not adversely affect envisaged application.

Examples of such substituents are alkyl, alkoxy or halogen.

Alkyl radicals include branched and in particular straight-chain alkyl understand, for example alkyl with one to six carbon atoms, in particular Methyl.

Alkoxy radicals include branched and in particular straight-chain alkoxy understand, for example alkoxy with one to six carbon atoms, especially methoxy.

If any radicals are halogen, these are, for example Fluorine, bromine or especially chlorine.

The matrix filaments used in the hybrid yarn according to the invention can be made from thermoplastic polymers, which are usually intrinsic Have viscosity of at least 0.5 dl / g, preferably 0.6 to 1.5 dl / g. The The intrinsic viscosity is measured in a solution of the thermoplastic Polymers in dichloroacetic acid at 25 ° C.

Are reinforcing filaments in the hybrid yarn to be used according to the invention used from polyester, these polyesters usually have an intrinsic Viscosity of at least 0.5 dl / g, preferably 0.6 to 1.5 dl / g. The measurement the intrinsic viscosity is as described above.

The hybrid yarns according to the invention usually have a yarn count of 6000 to 150 dtex, preferably from 4500 to 150 dtex.

The single fiber titer of the reinforcing filaments and the matrix filaments moves usually in the range of 2 to 10 dtex, preferably 4 to 8 dtex.

The cross sections of the reinforcing filaments and the matrix filaments can be arbitrary; for example elliptical, bi- or multilobal, ribbon-shaped or preferably round.

The thermoplastic polymers are produced according to known methods Process by polycondensation of the corresponding bifunctional Monomer components. In the case of polyesters usually come Dicarboxylic acids or dicarboxylic acid esters and the corresponding Diol components for use. Such thermoplastic and optionally elastomeric polyesters, polyurethanes, polyamides and polyolefins are already known.

It was also found that the preparation of the invention Hybridgame is possible using special blowing swirling processes.

The blowing is carried out by means of a fluid in a swirl nozzle, e.g. Water or in particular by a gas which is inert to the roving strands, in particular by air that may be humidified.

As is well known, the filament material of the blowing nozzle is also involved in the blowing fed at greater speed than withdrawn from it. The Excess speed of the feed compared to the deduction, expressed in Percentages based on the take-off speed are called the Overfeed.

Through different leads of roving skeins Make wind-whirled loop or plain yarns.

In this process, the blow-blowing process known per se is used modified in such a way that before shrinking the shrinkable Matrix filaments in the intermingling nozzle partially or completely shrink is triggered by heating. The advance of this roving component before The heating step must therefore be chosen larger in the process than without one such heating step. Depending on the selected advance when entering the Swirl nozzle and the selected swirl conditions can be Loop hybrid yarns or, in particular, hybrid plain yarns are obtained.

Conventional swirl nozzles can be used for swirling. The intermingling distance or the intermingling density is primarily determined by the pressure of the swirling medium and the selected nozzle type certainly. To achieve a desired swirl distance, one must a suitable swirl pressure can be selected for a specific nozzle type. The working pressure is expediently in the range from 1 to 8 bar, preferably from 1.5 to 6 bar, in particular from 1.5 to 3 bar.

a) Zuführen von zwei oder mehreren sich mit unterschiedlichen Geschwindigkeiten bewegenden Vorgarnsträngen zu einer Verwirbelungsdüse, wobei zumindest eine Teil der Vorgarnstränge (Verstärkungsvorgam) aus Verstärkungsfilamenten besteht und ein weiterer Teil der Vorgamstränge (Matrixvorgarn) aus tieferschmelzenden Matrixfilamenten aus thermoplastischen Polymeren besteht, die einen Thermoschrumpf bei 200 °C von mehr als 20 % aufweisen,

b) Erwärmen des Matrixvorgarnes während des Zuführens in die Verwirbelungsdüse auf eine derartige Temperatur, daß zumindest ein Teil des Schrumpfes ausgelöst wird,

c) Verwirbeln der Vorgamstränge in der Verwirbelungsdüse unter derartigen Bedingungen, daß sich ein primäres Hybridgarn ausbildet,

d) Abziehen des erhaltenen primären Hybridgames gegebenenfalls unter Zulassung von Schrumpf undloder zusätzliches, vorzugsweise berührungsloses Erhitzen.

The invention also relates to a method for producing the low-shrinkage hybrid yarns defined above, comprising the measures

a) Feeding two or more roving strands moving at different speeds to a swirling nozzle, wherein at least some of the roving strands (reinforcing pregam) consist of reinforcing filaments and a further part of the roving strands (matrix roving) consist of low-melting matrix filaments made of thermoplastic polymers, which heat shrink Have 200 ° C of more than 20%,

b) heating the matrix roving to a temperature such that at least part of the shrinkage is triggered, while being fed into the intermingling nozzle,

c) intermingling the Vorgamstrands in the interlacing nozzle under such conditions that a primary hybrid yarn is formed,

d) pulling off the primary hybrid game obtained, optionally with the approval of shrinkage and / or additional, preferably non-contact heating.

The triggering of the shrinkage of the matrix roving before entering the Swirling nozzle can be done according to methods known per se. For example by heating with godets, by contact with a heating rail or a heating pin, without contact by passing through a heating device, for example by a device as described in EP-A-579,092 or through a steam stuffer box process.

High-strength multifilament yarns can either already be used as reinforcement can be presented to the interlacing device or the multifilament yarns can stretched immediately before entering the swirl nozzle and if necessary be fixed.

Reinforcement rovings are preferably used which have a maximum tensile force, based on the final titer, of at least 60 cN / tex.

Other preferred reinforcement rovings exhibit thermal shrinkage 200 ° C from 2 to 8%.

Further preferred reinforcement programs have a maximum tensile strength extension of 0.5 to 25%.

The mechanical properties of the matrix examples are not very high Requirements. These at least have the swirling step survive.

After leaving the intermingling nozzle, the primary hybrid yarn subtracted, whereby usually only a low voltage may occur. Depending on the differences in the advance of the rovings and the A primary hybrid yarn with none, train a small or high proportion of loops. Becomes a plain yarn if desired, the primary yarn can have a low or high proportion of loops are heated with shrinkage approval. The loops pull together and the yarn structure is largely smoothed. Already in the Swirl nozzles created smooth games are usually pulled off directly and spooled.

The swirling of the hybrid game from reinforcement and matrix filaments of the above described first embodiment is preferably carried out by means of a special warm swirling process, which is described in EP-B-0,455,193. Here are the to avoid filament breaks when swirling Reinforcement filaments before they are swirled to near the softening point warmed (approx. 600 ° C for glass). The heating can be by godets and / or Heating tube done while the low melting thermoplastic Single filaments of polyester are also preheated to shrink trigger, and are fed to the higher swirl nozzle. The resulting smooth, high thread closure hybrid games are easy to use on the web.

It has been found that the production of hybrid yarns from reinforcement and Matrix filaments of the second embodiment described above surprisingly according to the usual swirling techniques, for example by intermingling or commingling techniques, such as for example in chemical fibers / textile industry, (7/8) 1989, T 185-7 described; however, by the heating step of the matrix roving described above modifies.

The hybrid games according to the invention can be according to methods known per se textile fabrics are processed. Examples include tissues, Knitted fabrics, knitted fabrics and, in particular, scrims. Such textile fabrics can by melting the matrix component in composite materials be transferred or stabilized.

The invention also relates to the use of the hybrid yarns for these purposes.

The following examples illustrate the invention without limiting it.

Examples 1) Production of low-shrinkage hybrid games

A coil with reinforcing process and a coil were placed on a creel submitted with Matrixvorgam. The nature of the Vorgame as well as the ones used Total titers are listed in Table 1 below.

The reinforcement roving was made by a delivery plant consisting of three godets fed directly to a swirl nozzle. In some trials, between the Delivery gods interposed a heater. It was a device for the contactless heating of running threads, as they in EP-A-569,082.

The matrix program was made up of a delivery plant consisting of two godets and an intermediate heating device also the texturing nozzle fed. Instead of or in addition to the intermediate heating device the delivery godets were heated. The heater was one Device for the contactless heating of running threads, as in the EP-A-579,092.

The ratio of the tradition before the swirl nozzle and the downstream take-off unit in the reinforcement roving and in the Matrix rovings are also given in the table below.

The temperatures of the godets of the delivery plants were between 80 and 130 ° C.

After exiting the intermingling nozzle, the primary hybrid yarn was subtracted another godet, the surface speed of the Galette was adjusted so that the yarn structure on the textile Performance characteristics has been optimized. Details on how to run the Procedures can be found in the table below.

The properties of the hybrid yarns obtained are shown in a further Table 2. Manufacturing conditions of the hybrid yarns Example No. Reinforcement roving (type; titer dtex) Matrix roving (type; titer dtex) tradition Heater / godet temperature reinforcing roving (° C) Heater / godet temperature Mat roving (° C) Reinforced. roving Roving matrix (%) 1 PET 1100 mod.PET 280 - 60 - 110 (gal) 2 PET 550 mod.PET 280 - 30 - 110 (gal) 3 Glass 3000 mod.PET 840 - 30 500 110 (gal) 4 Glass 3000 mod.PET 840 - 10 - 160 5 Glass 3000 mod.PET 830 - 30 500 110 (gal) 6 Glass 3000 mod.PET 750 - 60 500 210 60 (gal) 7 Aramid 1100 mod.PET 280 - 50 100 (gal) 110 (gal) 8th C-fiber 3000 mod.PET 840 - 50 110 (gal) 110 (gal) PET = polyethylene terephthalate
mod.PET = isophthalic acid-modified PET Properties of the hybrid yarns Example No. eff. Titer (dtex) Strength (cN / tex) Strain (%) Shrinkage at 200 ° C Shrinkage at 160 ° C 1 1600 50.2 18.1 3.5 1.1 2 930 37.9 21.8 3.9 1.0 3 4067 45.9 0.7 0 0 4 3880 46.5 0.8 0 0 5 4180 36.7 0.8 0.5 0 6 4590 39.8 0.8 3.1 0.6 7 1583 124.6 3.6 0.3 0 8th 3219 56.1 1.3 0.1 0

2) Production of low-shrinkage hybrid yarns (variation of the advance of the matrix feed)

Analogously to Example 1, hybrid games were produced by swirling. High-strength PET multifilament yarns with a titre of 1100 dtex were used as reinforcement and filament yarns with a titre of 280 dtex based on isophthalic acid-modified PET as matrix rovings. Details of the manufacturing conditions are listed in Table 3. The properties of the yarns obtained are shown in Table 4. Manufacturing conditions of the hybrid yarns Example No. tradition Heater / godet temperature reinforcing roving (° C) Heater / godet temperature Mat roving (° C) Reinforced. roving Roving matrix 9 - - - - 10 - 10% 100 (gal) 110 (gal) 11 - 20% 100 (gal) 110 (gal) 12 - 30% 100 (gal) 110 (gal) 13 - 40% 100 (gal) 110 (gal) 14 - 50% 100 (gal) 110 (gal) 15 - 60% 100 (gal) 110 (gal) Properties of the hybrid yarns Example No. eff. Titer (dtex) Strength (cN / tex) Strain (%) Shrinkage at 200 ° C Shrinkage at 160 ° C 9 1430 56.4 18.9 8.9 7 10 1455 55.8 18.0 5.4 1.9 11 1483 55.3 18.1 4.4 1.5 12 1517 53.7 18.2 4.2 1.4 13 1537 53.5 18.6 3.9 0.6 14 1577 50.5 17.9 3.7 1.1 15 1600 50.2 18.1 3.5 1.1 These examples show that the shrinkage of the intermingled yarn decreases as the advance of the matrix process increases.

3) Production of low shrinkage hybrid yarns (variation of the advance and heating the matrix roving)

Analogously to Example 1, hybrid games were produced by swirling. Glass multifilament yarns of 3000 dtex titre were used as reinforcement rovings and filament yarns of 750 dtex titre based on isophthalic acid-modified PET were used as matrix roving yarns. Details of the manufacturing conditions are listed in Table 5. The properties of the yarns obtained are shown in Table 6. Manufacturing conditions of the hybrid yarns Example No. tradition Heater / godet temperature reinforcing roving (° C) Heater / godet temperature Mat roving (° C) Reinforced. roving Roving matrix 16 - - - 210 17 - 10% - 210 18 - 20% - 210 19 - 30% - 210 20 - 40% - 210 21 - 50% - 210 + 60 (gal) 22 - 60% - 210 + 60 (gal) Properties of the hybrid yarns Example No. eff. Titer (dtex) Strength (cN / tex) Strain (%) Shrinkage at 200 ° C Shrinkage at 160 ° C 16 4181 36.1 1.1 65.5 nb 17 4250 34.4 0.7 33.4 nb 18 4310 28.7 0.9 29.5 nb 19 4380 27.5 0.7 25.1 nb 20 4450 29.3 1.1 18.8 nb 21 4515 30.8 1.3 7.5 3.8 22 4590 39.8 0.8 3.1 0.9 nb = not determined These examples show that the shrinkage of the intermingled yarn is reduced as the lead increases and the matrix process heats up.

4) Determination of the shrinkage of a hybrid yarn with different preload force

In analogy to the examples described above, a low-shrinkage hybrid yarn with reinforcing yarn made of PET and with matrix yarn made of isophthalic acid-modified PET was produced. The yarn titer was 1380 dtex. This game was loaded with different preload weights and treated for 15 minutes in a forced air oven at an air temperature of 100 ° C or 160 ° C. The following thermal shrinkage values were measured: Preload weight (cN) 0.16 0.5 0.8 1.5 3 Thermal shrink at 100 ° C 33.5 2.3 1 0.5 0.5 Thermal shrink at 160 ° C 0.4 0.3 0.3 0.2 0.1

5) Determine the swirl distance of hybrid games with different proportion of matrix component

In analogy to the examples described above, various low-shrinkage hybrid yarns with reinforcing roving made from high-strength PET and with matrix roving made from PET modified with isophthalic acid were produced. The yarns differed by the amount of the matrix component and by a different degree of intermingling. The swirl distance was determined using a Rothschild Entanglement Tester. The following values were measured: Volume% matrix in hybrid yarn 90 90 80 80 70 70 60 60 50 50 swirled intensely + - + - + - + - + - swirled flat - + - + - + - + - + Swirl distance (mm) 57 101 41 87 32 70 28 59 19 51

6) Characterization of properties of hybrid yarns with a Matrix component with different melting points

In analogy to the examples described above, low-shrinkage hybrid yarns were made from reinforcing pregam from PET and from matrix roving from different isophthalic acid-modified PET types. The manufacturing conditions were the same in each case. The matrix programs differed in the melting range of the PET type. The proportion of the matrix component in the hybrid games was 15 to 20% by volume. The delivery of the matrix roving was between 50 and 100%. Some properties of the hybrid yarns produced are listed in the following table. Hybrid yarn sample A B C Melting range mod.PET component (° C) about 130 approx. 170 approx. 225 Yarn titer (dtex) 1330 1313 1558 Thermal shrink at 160 ° C 0.7 0.9 0.9 Thermal shrink at 200 ° C 1.3 1.8 1.9 Ultimate tensile strength (%) 16 16.5 15.8 Maximum tensile force (cN / tex) 51 52.5 48.8

It can be seen that there are hybrid games with different melting ranges the matrix component but produce comparable mechanical properties to let.

Claims (16)

1. Hybrid yarns comprising reinforcing filaments and matrix filaments composed of thermoplastic polymers having a lower melting point than the reinforcing filaments, characterized in that a hot air shrinkage under a load of 0.0004 cN/dtex and at an air temperature of 160 °C is not more than 2 %, and at an air temperature of 200 °C is not more than 5 %, especially not more than 3 % and that the static shrinkage force, at temperatures of up to 200 °C amounts up to 0.01 cN/dtex.
2. Hybrid yarns of claim 1, characterized by a hot air shrinkage under a load of 0.0004 cN/dtex and at a temperature of 160 °C of not more than 1 %.
3. Hybrid yarns of claim 1, characterized by an entanglement spacing of less than 60 mm, preferably less than 30 mm, as measured using a 2050 Rothschild Entanglement Tester.
4. Hybrid yarns of claim 1 as flat yarns.
5. Hybrid yarns of claim 1, wherein the matrix filaments composed of thermoplastic polymers have a melting point which is at least 30 °C below the melting or decomposition point of the reinforcing filaments.
6. Hybrid yarns of claim 1, wherein the reinforcing filaments have an initial modulus of greater than 50 Gpa and preferably consist of glass, carbon or aromatic polyamide.
7. Hybrid yarns of claim 1, wherein the reinforcing filaments have an initial modulus of greater than 10 Gpa and consist of polyester, especially of polyethylene terephthalate.
8. Hybrid yarns of claim 1, wherein the matrix filaments consist of polybutylene terephthalate and/or of polyethylene terephthalate and/or of chemically modified polyethylene terephthalate.
9. Hybrid yarns of claim 1, wherein reinforcing filaments and matrix filaments consist of the same class of polymer, preferably of polyamide/polyamide, polyolefin/polyolefin or especially polyester/polyester combinations.
10. Hybrid yarns of claim 1, wherein the matrix filaments consist of a chemically modified polyethylene terephthalate containing structural repeat units of the formulae I and II -O-OC-Ar¹-CO-O-R¹- O-OC-R²-CO-O-R³- where Ar¹ is a bivalent mono- or polycyclic aromatic radical whose free valences are disposed para or comparably parallel or coaxial to each other, preferably 1,4-phenylene and/or 2,6-naphthalene,
    R¹ and R³ are independently of each other bivalent aliphatic or cycloaliphatic radicals, especially radicals of the formula -C_nH_2n-, where n is a integer between 2 and 10, especially ethylene, or a radical derived from cyclohexanedimethanol, and
    R² is a bivalent aliphatic, cycloaliphatic or mono- or polycyclic aromatic radical whose free valences are disposed meta or comparably angled to each other, preferably 1,3-phenylene.
11. Hybrid yarns of claim 10, wherein the matrix filaments consist of a chemically modified polyethylene terephthalate containing 40 to 95 mol% of structural repeat units of the formula I and 60 to 5 mol% of structural repeat units of the formula II where Ar¹ is 1,4-phenylene and/or 2,6-naphthalene, R¹ and R³ are each ethylene and R² is 1,3-phenylene.
12. Hybrid yarns of claim 1, wherein the matrix filaments consist of a thermoplastic and elastomeric polymer, especially of a polyurethane, a polyamide or preferably of a polyester.
13. A process for producing the low-shrinkage hybrid yarns of claim 1, which comprises the measures of

    a) feeding two or more feed yarn strands moving at different speeds into an entangling jet, at least a portion of the feed yarn strands (reinforcing feed yarn) consisting of reinforcing filaments and a further portion of the feed yarn strands (matrix feed yarn) consisting of lower melting matrix filaments composed of thermoplastic polymers having at 200 °C a hot air shrinkage of more than 20 %,

    b) heating the matrix feed yarn during the feeding into the entangling jet to such a temperature that at least a portion of the shrinkage is released,

    c) entangling the feed yarn strands in the entangling jet under such conditions that a primary hybrid yarn is formed, and

    d) taking off the resulting primary hybrid yarn with or without shrinkage and/or additional heating.
14. The process of claim 13, wherein the differences in the leading of the feed yarns entering the entangling jet are chosen so that the resulting entangled yarn is a flat hybrid yarn.
15. The process of claim 13, wherein the differences in the leading of the feed yarns entering the entangling jet are chosen so that the resulting entangled yarn is a loop hybrid yarn whose loops are substantially flattened out again through release of the shrinkage in one or more successive heating stages.
16. The use of the low-shrinkage hybrid yarns of claim 1 for producing composites or textile sheet articles, especially for producing laid articles.