EP0801159A2 - Low-shrinking hybrid yarns, method for its production and its use - Google Patents

Abstract

Composite yarns comprising reinforcing filaments and matrix filaments consisting of a thermoplastic polymer with a lower m.pt. than the degradation temperature or m.pt. of the reinforcing filament material. The yarns have heat shrinkage values less than or equal to 2 (1) and 5 (3) % in air at 160 and 200 degrees C respectively, measured under a load of 0.0004 cN/tex. The preparation of these yarns is also claimed.

Description

The present invention relates to new hybrid yarns which are distinguished by a particularly low thermal shrinkage. Such yarns can advantageously be processed into composite materials or textile fabrics, such as scrims.

Hybrid yarns, i.e. yarns made from reinforcement and matrix filaments, are known per se. Such yarns are used, for example, as intermediate products for the production of composite materials. For this purpose, a textile fabric is usually first produced from the hybrid yarn; The matrix filaments of these hybrid yarns are then converted by melting or melting into a matrix which embeds or flows around the reinforcement filaments and, together with them, builds up the composite.

The matrix filaments are generally not subject to high requirements with regard to strength and other mechanical properties, since these are melted anyway in later processing steps. This eliminates the need for costly post-spinning treatment such as stretching or fixing in the manufacture of such filaments. Matrix filaments therefore inherently show considerable thermal shrinkage, which can adversely affect the product in the later processing steps.

There is a need for hybrid yarns that have low shrinkage. Such yarns naturally do not shrink or only to a very small extent when heated to form the matrix. As a result, the position of the reinforcement filaments is not or only slightly disturbed when the matrix is produced. These new yarns also significantly simplify the production of scrims. So far, when fixing the superimposed Elaborate measures are taken during the production of the scrim to intercept the shrinkage of the yarn caused by the heating and to stabilize the primary scrim. With the new hybrid yarns, these measures can largely be dispensed with.

So-called two-component loop yarns with high strength and low shrinkage are known. Such yarns were developed in particular for use as sewing threads and are described, for example, in EP-B-363,798. However, such yarns usually do not have matrix filaments made from deep-melting filaments, but are made up of filaments of one type but of different strengths, which are arranged in a core-sheath structure.

A process has now been found for the production of low-shrinkage hybrid yarns which leads to products with the property profile described above. The yarns according to the invention are distinguished by a very low thermal shrinkage over a relatively large temperature interval.

The present invention relates to low-shrinkage hybrid yarns containing reinforcing filaments and matrix filaments made of thermoplastic polymers which have a lower melting point than the melting or decomposition point of the reinforcing filaments. The hybrid yarns according to the invention are characterized in that they have a thermal shrinkage, measured on a yarn sample under a load of 0.0004 cN / dtex at an air temperature of 160 ° C, of less than or equal to 2%, in particular of less than or equal to 1%, and at Air temperature of 200 ° C of less than or equal to 5%, in particular less than or equal to 3%.

In order to determine the thermal shrinkage of the hybrid yarns according to the invention, loops are formed at the two ends of six yarn samples, each 60 cm long, and these yarn samples are hooked onto their loops on a shrink rod. These yarn samples are each subjected to a preload force of 0.0004 cN / dtex. The shrink bar with the Yarn samples are suspended in a forced air oven and then treated with hot air at a defined temperature for 15 minutes. The change in length of the yarn sample before and after heating in% represents the thermal shrinkage.

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

The term "hybrid yarn" is to be understood in its broadest meaning within the scope of this description. Accordingly, this includes any combination containing reinforcing filaments and the matrix filaments defined above.

Examples of possible hybrid yarn types are filament yarns from different types of filaments which are interwoven with one another or combined with one another by means of another technology, such as for example twisting. All of these hybrid yarns are characterized by the presence of two or more types of filaments, at least one type of filament being a reinforcing filament and at least one type of filament being a matrix filament as defined above.

Hybrid yarns produced by intermingling or commingling techniques are particularly preferably used; it can be loop yarns, but preferably plain yarns.

The smooth yarns according to the invention are notable for particularly good processability with area-forming technologies and good fabric samples.

The hybrid yarns according to the invention preferably have a static shrinkage force, measured according to DIN 53866, part 12, at temperatures of up to 200 ° C. of up to 0.01 cN / dtex.

To measure the static shrinkage, five yarn samples each 60 cm long are clamped in two clamps under a preload of 0.01 cN / dtex. The clamped yarn sample is then treated with air of the desired temperature for one minute. The force that occurs when heating in the longitudinal direction of the thread is the static shrinkage and reaches a saturation value after a short time interval.

The number of intermingling points in the hybrid yarns according to the invention can be set within wide ranges by the selection of the intermingling conditions. The higher the proportion of the mechanically relatively unstable matrix component, the less intensely the intermingling can be carried out and consequently the distance between the intermingling points in such yarns is normally relatively 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 the reinforcing filament elements used in each case.

The reinforcing filaments used in the hybrid yarns according to the invention can be filaments made from a large number of materials. In addition to organic polymers, inorganic materials can also be used. Reinforcement filaments in the sense of this description mean filaments which assume a reinforcing function in the desired textile fabric or composite material.

In a first preferred embodiment, the reinforcement filaments are constructed from individual filaments which have an initial modulus of more than 50 GPa.

Preferred reinforcing filaments of this type are made of glass; Carbon; Metals or metal alloys, such as steel, aluminum or tungsten; Non-metals such as boron; Metal, semimetal 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 provide a very high initial modulus and a very high tensile strength with little or no stretching), such as liquid-crystalline polyesters (LCP), poly (bis-benzimidazo-benzophenanthrolines (BBB), poly (amide -imides) (PAI), polybenzimidazoles (PBI), poly (p-phenylene benzobisoxazoles (PBO), poly (p-phenylene benzobisthiazoles) (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- Methyl pyrrolidone, spinnable aramids derived from terephthalic acid dichloride and a mixture of two or more aromatic diamines, for example the Kombina tion 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 aromatic polyamide are particularly preferred.

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

In this embodiment, the individual filaments of the reinforcement filaments have an initial modulus of more than 10 GPa. Reinforcing filaments for this embodiment are preferably high-strength and low-shrinkage polyester filament yarns, in particular with a yarn titer of less than or equal to 1100 dtex, a tenacity of greater than or equal to 55 cN / tex, a maximum tensile strength elongation of greater than or equal to 12% and a hot air shrinkage (measured at 200 ° C.) of less equal to 9%.

The maximum tensile force and the maximum tensile force elongation of the polyester yarns used are measured in accordance with DIN 53 830, Part 1.

Matrix filaments in the hybrid yarns according to the invention consist of or contain thermoplastic polymers. These can be any melt-spinnable thermoplastics, as long as the filaments produced therefrom melt at a temperature which is lower than the melting or decomposition temperature of the reinforcing filaments used in the respective case.

Matrix filaments of polybutylene terephthalate and / or of polyethylene terephthalate and / or of chemically modified polyethylene terephthalate are preferred.

Matrix filaments made of a thermoplastic modified polyester, in particular a modified polyethylene terephthalate, are very particularly preferably used; the modification lowers the melting point compared to 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 - (I),



-O-OC-R ² -CO-OR ³ - (II),

in which Ar ^{1 represents} a divalent mono- 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 angular 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 which consist of or contain a thermoplastic and elastomeric polymer. These can also be any melt-spinnable and elastomeric thermoplastics, as long as the filaments produced therefrom melt at a temperature which is lower than the melting or decomposition temperature of the reinforcing filaments used in the respective case.

In the context of this description, “elastomeric polymer” is understood to mean a polymer whose glass transition temperature is less than 0 ° C., preferably less than 23 ° C.

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

If any radicals in the structural formulas defined above mean divalent aliphatic radicals, this means branched and in particular straight-chain 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 are 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 -.

If any radicals in the structural formulas defined above mean divalent aromatic radicals, these are mono- or polynuclear aromatic hydrocarbon radicals or heterocyclic-aromatic radicals which can be mono- or polynuclear. In the case of heterocyclic-aromatic radicals, these have in particular one or two oxygen, nitrogen or sulfur atoms in the aromatic nucleus.

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

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

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

Examples of preferred divalent aromatic radicals whose valence bonds are in para- or in a comparable coaxial or parallel position to one another are mononuclear aromatic radicals with mutually para-free valences, in particular 1,4-phenylene or dinuclear fused aromatic radicals with parallel directed bonds, in particular 1,4-, 1,5- and 2,6-naphthylene, or dinuclear aromatic residues linked via a CC bond with coaxial, oppositely directed bonds, in particular 4,4'-biphenylene.

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

All of these aliphatic, cycloaliphatic or aromatic radicals can be substituted with inert groups. These are to be understood as substituents that do not negatively influence the envisaged application.

Examples of such substituents are alkyl, alkoxy or halogen.

Alkyl radicals are to be understood as meaning branched and in particular straight-chain alkyl, for example alkyl having one to six carbon atoms, in particular methyl.

Alkoxy radicals are to be understood as meaning branched and in particular straight-chain alkoxy, for example alkoxy having one to six carbon atoms, in particular methoxy.

If any radicals are halogen, it is, for example, fluorine, bromine or, in particular, chlorine.

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

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

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

The individual fiber titer of the reinforcing filaments and the matrix filaments usually ranges from 2 to 10 dtex, preferably 4 to 8 dtex.

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

The thermoplastic polymers are prepared by processes known per se by polycondensation of the corresponding bifunctional monomer components. In the case of polyesters, dicarboxylic acids or dicarboxylic acid esters and the corresponding diol components are usually used. Such thermoplastic and optionally elastomeric polyesters, polyurethanes, polyamides and polyolefins are already known.

It has furthermore been found that the hybrid yarns according to the invention can be produced by means of special blowing intermingling 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, which may be humidified.

As is known, in the process of blowing the filament, the filament material is fed to the blowing nozzle at a higher speed than is drawn from it. The excess speed of the feed compared to the take-off, expressed as a percentage of the take-off speed, is referred to as the advance.

Blown-twisted loop or plain yarns can be produced by different ropes of roving strands.

In these processes, the blow-swirling process known per se is modified in such a way that before the highly shrinkable matrix filaments run into the swirling nozzle, their shrinkage is partially or completely triggered by heating. The leading of this roving component before the heating step is therefore to be chosen larger in the method than without such a heating step. Depending on the selected advance when entering the intermingling nozzle and the selected intermingling conditions, loop hybrid yarns or in particular hybrid plain yarns can be obtained.

Conventional swirl nozzles can be used for swirling. The intermingling distance or the intermingling density is primarily determined by the pressure of the intermingling medium and the nozzle type selected in each case. In order to achieve a desired swirl distance, a corresponding swirl pressure must 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 (Verstärkungsvorgarn) aus Verstärkungsfilamenten besteht und ein weiterer Teil der Vorgarnstränge (Matrixvorgarn) aus tieferschmelzenden Matrifilamenten 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 Vorgarnstränge in der Verwirbelungsdüse unter derartigen Bedingungen, daß sich ein primäres Hybridgarn ausbildet,
• d) Abziehen des erhaltenen primären Hybridgarnes gegebenenfalls unter Zulassung von Schrumpf und/oder 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 intermingling nozzle, wherein at least some of the roving strands (reinforcing roving) consist of reinforcing filaments and another part of the roving strands (matrix roving) consists of low-melting matrifilaments made of thermoplastic polymers, which are heat shrinkable 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 roving strands in the intermingling nozzle under conditions such that a primary hybrid yarn is formed,
• d) pulling off the primary hybrid yarn obtained, optionally with the approval of shrinkage and / or additional, preferably non-contact heating.

The shrinkage of the matrix roving prior to entering the intermingling nozzle can be triggered by methods known per se. For example by heating by means of 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 by a steam stuffer box method.

As reinforcing rovings, either high-strength multifilament yarns can be placed in the interlacing device or the multifilament yarns can be stretched and, if necessary, fixed immediately before entering the interlacing nozzle.

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

Further preferred reinforcement rovings have a thermal shrinkage at 200 ° C. of 2 to 8%.

Other preferred reinforcement rovings have a maximum tensile strength stretch of 0.5 to 25%.

No high demands are made on the mechanical properties of the matrix rovings. These must at least survive the swirling step.

After leaving the intermingling nozzle, the primary hybrid yarn is drawn off, with usually only a low tension being allowed to occur. Depending on the differences in the advance of the rovings and the intermingling conditions in the nozzle, a primary hybrid yarn can be formed with no, little or a high proportion of loops. If a plain yarn is desired, the primary yarn can be heated with a low or high proportion of loops with shrinkage approval. The loops contract and the yarn structure is largely smoothed. Smooth yarns that have already formed in the intermingling nozzle are usually drawn off and wound up directly.

The interlacing of the hybrid yarns from reinforcement and matrix filaments of the first embodiment described above is preferably carried out by means of a special warm interlacing process, which is described in EP-B-0,455,193. In order to avoid filament breakage during swirling, the reinforcement filaments are warmed up to near the softening point before swirling (approx. 600 ° C for glass). The heating can be done by godets and / or heating tube, while the low-melting thermoplastic single filaments made of polyester are also preheated to trigger the shrinkage and fed to the higher-level swirl nozzle. The resulting smooth, high-thread-lock hybrid yarns are easily weaved.

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

The hybrid yarns according to the invention can be processed into textile fabrics by methods known per se. Examples of this are woven fabrics, knitted fabrics, knitted fabrics and, in particular, scrims. Such textile fabrics can be converted or stabilized by melting the matrix component in composite materials.

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-shrink hybrid yarns

A bobbin with reinforcing roving and a bobbin with matrix roving were placed on a creel. The nature of the rovings and the yarn titer used are listed in Table 1 below.

The reinforcing roving was fed directly to a intermingling nozzle via a delivery system consisting of three godets. In some trials, a heater was interposed between the delivery godets. This was a device for the contactless heating of running threads, as described in EP-A-569,082.

The matrix roving was also fed to the texturing nozzle via a delivery unit consisting of two godets and a heating device arranged between them. Instead of or in addition to the intermediate heating device, the delivery godets were heated. The heating device was a device for the contactless heating of running threads, as described in EP-A-579,092.

The relationship between the delivery before the intermingling nozzle and the downstream take-off unit for the reinforcement roving and for the matrix roving is also given in the table below.

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

After leaving the intermingling nozzle, the primary hybrid yarn was drawn off by means of a further godet, the surface speed of the godet being adjusted in such a way that the yarn structure was optimized for the textile properties. Details on the implementation of the procedure can be found in the table below.

The properties of the hybrid yarns obtained are shown in a further Table 2. Table 1 Manufacturing conditions of the hybrid yarns Example No. Reinforcement roving (type; titer dtex) Matrix roving (type; titer dtex) Lore Heater / godet temperature reinforcing roving (° C) Heater / godet temperature Mat roving (° C) Ampl. roving Roving matrix (%) 1 PET 1100 mod.PET 280 - 60 - 110 (gal) 2nd PET 550 mod.PET 280 - 30th - 110 (gal) 3rd Glass 3000 mod.PET 840 - 30th 500 110 (gal) 4th Glass 3000 mod.PET 840 - 10th - 160 5 Glass 3000 mod.PET 830 - 30th 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 2nd 930 37.9 21.8 3.9 1.0 3rd 4067 45.9 0.7 0 0 4th 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 roving)

Analogous to Example 1, hybrid yarns were produced by intermingling. High-strength PET multifilament yarns with a titre of 1100 dtex were used as reinforcing rovings 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. Table 3 Manufacturing conditions of the hybrid yarns Example No. Lore Heater / godet temperature reinforcing roving (° C) Heater / godet temperature Mat roving (° C) Ampl. roving Roving matrix 9 - - - - 10th - 10% 100 (gal) 110 (gal) 11 - 20% 100 (gal) 110 (gal) 12th - 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 10th 1455 55.8 18.0 5.4 1.9 11 1483 55.3 18.1 4.4 1.5 12th 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 roving increases.

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

Analogous to Example 1, hybrid yarns were produced by intermingling. 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 as matrix rovings. Details of the manufacturing conditions are listed in Table 5. The properties of the yarns obtained are shown in Table 6. Table 5 Manufacturing conditions of the hybrid yarns Example No. Lore Heater / godet temperature reinforcing roving (° C) Heater / godet temperature Mat roving (° C) Ampl. roving Roving matrix 16 - - - 210 17th - 10% - 210 18th - 20% - 210 19th - 30% - 210 20th - 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 17th 4250 34.4 0.7 33.4 nb 18th 4310 28.7 0.9 29.5 nb 19th 4380 27.5 0.7 25.1 nb 20th 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 decreases as the lead increases and the matrix roving heats up more.

4) Determination of the shrinkage of a hybrid yarn with different pretensioning forces

In analogy to the examples described above, a low-shrinkage hybrid yarn with reinforcing roving made of PET and with matrix roving made of isophthalic acid-modified PET was produced. The yarn titer was 1380 dtex. This yarn was loaded with different pretension weights and each 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 3rd 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) Determination of the intermingling distance of hybrid yarns with different proportions of matrix components

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 isophthalic acid-modified PET 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 19th 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 produced from reinforcing roving made from PET and from matrix roving made from different types of PET modified with isophthalic acid. The manufacturing conditions were the same in each case. The matrix rovings differ in the melting range of the PET type. The proportion of the matrix component in the hybrid yarns 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 Maximum tensile force elongation (%) 16 16.5 15.8 Maximum tensile force (cN / tex) 51 52.5 48.8

It can be seen that hybrid yarns with different melting ranges of the matrix component but comparable mechanical properties can be produced.

Claims (16)

Hybrid yarns containing reinforcing filaments and matrix filaments made of thermoplastic polymers, which have a lower melting point than the melting or decomposition point of the reinforcing filaments, characterized in that the hybrid yarns undergo thermal shrinkage, measured on a yarn sample under a load of 0.0004 cN / dtex at an air temperature of 160 ° C, less than or equal to 2%, in particular less than or equal to 1%, and at an air temperature of 200 ° C of less than or equal to 5%, in particular less than or equal to 3%. Hybrid yarns according to claim 1, characterized in that they have a static shrinkage force, measured according to DIN 53866, part 12, at temperatures of up to 200 ° C of up to 0.01 cN / dtex. Hybrid yarns according to claim 1, characterized in that they have a swirl distance of less than 60 mm, preferably less than 30 mm, this value relating to a measurement with the Rothschild Entanglement needle tester 2050. Hybrid yarn according to claim 1, characterized in that it is plain yarn. Hybrid yarns according to claim 1, characterized in that the matrix filaments made of thermoplastic polymers have a melting point which is at least 30 ° C below the melting or destruction point of the reinforcing filament. Hybrid yarns according to claim 1, characterized in that the reinforcing filaments have an initial modulus of greater than 50 Gpa and preferably consist of glass, carbon or aromatic polyamide. Hybrid yarns according to claim 1, characterized in that the reinforcing filaments have an initial modulus of greater than 10 GPa and consist of polyester, in particular of polyethylene terephthalate. Hybrid yarns according to claim 1, characterized in that the matrix filaments consist of polybutylene terephthalate and / or of polyethylene terephthalate and / or of chemically modified polyethylene terephthalate. Hybrid yarns according to claim 1, characterized in that reinforcing filaments and matrix filaments consist of a polymer class, preferably of combinations of polyamide / polyamide, polyolefin / polyolefin or in particular of polyester / polyester. Hybrid yarns according to claim 1, characterized in that the matrix filaments consist of a chemically modified polyethylene terephthalate containing the recurring structural units of the formulas I and II

-O-OC-Ar ¹ -CO-OR ¹ - (I),



-O-OC-R ² -CO-OR ³ - (II),

in which Ar ^{1 represents} a divalent mono- 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 represent two-part 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 a divalent aliphatic, cycloaliphatic or mono- or represents polynuclear aromatic radical, the free valences of which are in the meta position or in an angular position comparable to this position, preferably represents 1,3-phenylene. Hybrid yarns according to Claim 10, characterized in that the matrix filaments consist of a chemically modified polyethylene terephthalate which contains 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 1.4 -Phenylene and / or 2,6-naphthylene, R ¹ and R ^{3 are} ethylene and R ^{2 is} 1,3-phenylene. Hybrid yarns according to claim 1, characterized in that the matrix filaments consist of a thermoplastic and elastomeric polymer, in particular a polyurethane, a polyamide or preferably a polyester. A method for producing the low shrinkage hybrid yarn according to claim 1 comprising the measures a) Feeding two or more roving strands moving at different speeds to a intermingling nozzle, wherein at least some of the roving strands (reinforcing roving) consist of reinforcing filaments and a further part of the roving strands (matrix roving) consist of melting 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 roving strands in the intermingling nozzle under conditions such that a primary hybrid yarn is formed, and d) drawing off the primary hybrid yarn obtained, optionally with shrinkage and / or additional heating. A method according to claim 13, characterized in that the differences in the advance of the rovings entering the intermingling nozzle are selected so that a hybrid smooth yarn is formed during intermingling. A method according to claim 13, characterized in that the differences in the advance of the rovings entering the intermingling nozzle are selected such that a hybrid loop yarn is formed during intermingling, the loops of which are largely smoothed out again by triggering the shrinkage in one or more subsequent heating stages. Use of the low-shrinkage hybrid yarns according to claim 1 for the production of composite materials or textile fabrics, in particular for the production of scrims.