EP2013384B2 - Nonwoven - Google Patents

Abstract

Polymer thread comprises a thermoplastic polymer and an inorganic filler material, where the amount of filler material present is greater than 10 % with an average particle size (D 50) of =6 mu m. Independent claims are included for a procedure for the preparation of polymer fiber/flat textile structure comprising mixing polymer granulate with a particles of filler material; extruding the mixture through one or more spinning nozzle; removing the formed polymer thread; optionally stretching and/or relaxing the formed filament; and rolling the formed thread.

Description

The invention relates to a nonwoven fabric made of polymer threads, comprising a thermoplastic polymer and an inorganic filler and the production of nonwovens.

From the prior art, the production of polymer fibers for nonwoven production with the addition of inactive mineral fillers is known in principle.

Out WO 97/30199 A For example, soft-particle-containing polyolefin fibers and filaments having improved properties in terms of their solidification behavior during thermobonding are known to produce a broader consolidation window compared to nonwoven webs of fibers or filaments without particles. An indication of the retention of the mechanical properties or the permeability of the nonwovens is not given.

US 2006/084346 A1 is based on gas-permeable spun-bonded sheet materials, which have a higher liquid barrier than traditional products and also have good physical properties. In a solution spinning process, filament strands are formed as a three-dimensional, integral network. For this purpose, halocarbon-based solvents are used.

EP 0 841 415 A2 discloses fibers containing fine inorganic particles in high concentration, aiming for good processability and physical properties. However, in order to ensure this, it is necessary to add high molecular weight substances having polar groups which are absorbed at the interface of the fine inorganic particles or which have a high affinity for the interface of the inorganic particles and improve the thermodynamic compatibility between the polymer and the filler.

EP 0 298 767 A2 discloses yarns with high filler contents and their preparation. In order to improve the strength properties of the highly filled yarns, orientation within the yarns during spinning and drawing is sought, which is associated with a drastic reduction in extensibility.

The publication US Pat. No. 6,797,377 B1 describes a process for producing a fabric from a polymer or polymer mixture having a cloth-like structure which has a mineral filler content of up to 10%. To ensure the softness of the fabric with increasing filler content, a filler mixture is used. Thus, it has been found that especially the addition of TiO ₂ prevents the increasing stiffening of the fabric at higher filler contents. Therefore, according to the doctrine of US Pat. No. 6,797,377 used exclusively a mixture of TiO ₂ and another mineral filler. Regarding the particle size of the filler is in the US 6797 377 a size of 10 to 150 microns provided.

The US Pat. No. 6,797,377 gives no indication of the material properties when increasing the filler content and at the same time waiving the addition of TiO ₂ . The importance of particle size and particle shape for the properties of the final product at higher filler levels is also not disclosed.

Against this background, the object of the invention is to provide a nonwoven fabric of polymer filaments having a higher filler content, wherein a nonwoven fabric produced from the polymer yarn, compared to a nonwoven fabric of a polymer thread having a filler content <10% by weight, have substantially unchanged properties should. The air permeability, the water column, the average pore size, the penetration times and the mechanical properties, measured as maximum tensile force and maximum tensile elongation are examples of those nonwoven properties that remain substantially unchanged at the filler content of the invention.

• die mittlere Partikelgröße (D₅₀) des Füllstoffs kleiner oder gleich 6 µm ist,
• das Flächengewicht zwischen 7 g/m² und 500 g/m²liegt,
• das Produkt aus Flächengewicht und Luftdurchlässigkeit nach DIN EN ISO 9237 im Bereich von 88.000 bis 132.000 ist und
• die Werte für den Quotienten aus Wassersäule nach DIN EN 20811 und Flächengewicht im Bereich von 2,5 ± 0,5 liegen.

To achieve the object, the invention teaches a nonwoven fabric of polymer threads comprising a thermoplastic polymer and an inorganic filler, wherein the filler content, based on the polymer thread, more than 10% by weight, wherein

• the mean particle size (D ₅₀ ) of the filler is less than or equal to 6 μm,
• the basis weight is between 7 g / m ² and 500 g / m ² ,
• the product of basis weight and air permeability according to DIN EN ISO 9237 is in the range of 88,000 to 132,000 and
• the values for the quotient of water column according to DIN EN 20811 and basis weight are in the range of 2.5 ± 0.5.

The core idea of the invention is the recognition that, when the filler content is significantly increased, the particle size of the filler plays a decisive role in ensuring the constancy of the properties of the polymer thread or of the nonwovens produced therefrom.

The inventors have recognized that with increased filler content especially the uniform dispersion of the filler in the polymer matrix ensures the consistency of the material properties and they have recognized that the uniformity of the dispersion is essentially dependent on the size and shape of the particles of the filler. For the increased filler content, the range of the appropriate average particle size was determined. This is at a filler content of more than 10% by weight slurry ≤ 6 microns (D ₅₀ ).

Before describing the preferred embodiments of the nonwoven fabric according to the invention made of polymer filaments, the general terms used for the description of the invention for clarification are briefly explained below and put into the context of the invention:

terms

A "thread" in the sense of the invention is a line-shaped structure which forms the basic element of a textile fabric. Thus, the term "thread" is to be understood as a common generic term for the terms "filament" and "fiber". A "fiber" differs conceptually from a "filament" by its finite length. "Filaments" are thus u.a. to understand as endless fibers.

"Polymers" are macromolecular substances that are composed of simple molecules (monomers) by polymerization, polycondensation or polyaddition.

"Filament-forming polymers" in the context of the invention are polymers which have properties in their melt or solution which fulfill the conditions of spinnability. The conditions for the spinnability of polymers were described by Nitschman and Schrade (Helv. Chem. Acta 31 (1948) 297 ) and through Hirai (Rheol. Acta 1 (1958) 213 ) as well as by Ziabicki and Taskerman-Krozer (Colloid Z. 198 (1964) 60 ). A "filler" within the meaning of the invention relates to particles and other forms of materials that can be added to the polymer extrusion mixture, wherein the particles do not affect the polymer and distribute evenly throughout the extrusion mixture. The filler can be made of different materials, with variations in the shape and size of the particles.

"Textile fabrics" in the context of this description are woven, knitted, knitted or nonwoven fabrics. "Nonwovens" are thus a subspecies of textile fabrics. They consist of fiber webs, e.g. are solidified by mechanical methods or by binding fibers or chemical aids or combinations thereof.

under claims

In a preferred embodiment, the filler of the nonwoven fabric according to the invention of polymer threads consists of an alkaline earth carbonate, in particular of calcium carbonate. Calcium carbonate is an ideal filler, which is characterized by the following, among others by JT Lutz, and RF Grossman (Eds.), "Polymer Modifiers and Additives", Marcel Dekker, Inc. 2001, page 125 et seq. Characteristics characterized: chemically inert to the polymer or other additives; low specific gravity, desired refractive index and color, low cost.

It should be remembered that calcium carbonate is normally derived from natural chalk deposits and that local geological conditions determine the level of additional minerals in the chalk. For example, in the chalk, among other alkaline earth carbonates, e.g. also metal oxides such as e.g. Be contained iron oxide.

Of course, the use of various alkaline earth metal carbonates or a mixture of two or more of these compounds is conceivable. In particular, calcium carbonate (CaCO ₃ ) or magnesium carbonates (MgCO ₃ ) or barium carbonate (BaCO ₃ ) are provided. The filler consists of at least 90% by weight, preferably 95% by weight, in particular 97% by weight of calcium carbonate.

Other fillers, one or more of which may be used with or without an alkaline earth carbonate, include iron oxides, alumina (Al ₂ O ₃ ) or silica (SiO ₂ ) or calcium oxide (CaO) or magnesium oxide (MgO) or barium sulfate (BaSO ₄ ) or magnesium sulfate (MgSO ₄ ) or aluminum sulfates (AlSO ₄ ) or aluminum hydroxide (AlOH ₃ ). Also suitable are alumina (kaolin), zeolites, kieselguhr, talc, mica or carbon black.

Titanium dioxide (TiO ₂ ) is also a common filler which can in principle also be used in connection with the invention. However, it has surprisingly been found that at higher calcium carbonate contents entirely on the addition of the matting agent titanium dioxide (TiO ₂ ) can be dispensed with. Noteworthy is this fact in view of the task of the present invention, because titanium oxide is more expensive than calcium carbonate and thus an additional cost advantage is given.

In the particularly preferred embodiments of the nonwoven fabric of polymer threads according to the invention, the filler content is between 15 and 25 percent by weight, based on the weight of the polymer thread.

With regard to the particle size, the preferred range of the fillers used according to the invention is <6 μm. This preferably corresponds to a top cut (D ₉₈ ) of the filler particles of ≦ 10 μm. The value in this case indicates that only 2% of the filler particles are> 10 μm.

In a particularly preferred embodiment, the particle size is 2-6 microns. The mentioned lower limit makes no statement on the feasibility of the invention with even smaller particle sizes, but characterizes the range of those particle sizes which ensure a uniform dispersion and at the same time are available at favorable cost prices.
With regard to the particle shape of the filler, a distinction is made between spherical (eg glass or silicate spheres), cube-shaped (eg calcium carbonate), cuboid (eg barium sulfate or silica), platelet-shaped (eg talc or mica) or cylindrical particles.

For the recovery of the nonwoven fabric of polymer threads according to the invention are generally all thermoplastic compounds in question. The important thread-forming, spinnable thermoplastic polymers are polyolefins, polyesters, polyamides or halogen-containing polymers.

The class of polyolefins includes i.a. Polyethylene (HDPE, LDPE, LLDPE, VLDPE, ULDPE, UHMW-PE), polypropylene (PP), poly (1-butene), polyisobutylene, poly (1-pentene), poly (4-methylpent-1-ene), Polybutadiene, polyisoprene, and various olefin copolymers. Besides these, heterophasic blends are also among the polyolefins. Thus, for example, polyolefins, in particular polypropylene or polyethylene, graft or copolymers of polyolefins and α, β-unsaturated carboxylic acids or carboxylic anhydrides, polyesters, polycarbonate, polysulfone, polyphenylene sulfide, polystyrene, polyamides or a mixture of two or more of said compounds can be used.

Among the polyesters are i.a. Polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), but also degradable polyesters such as polylactic acid (polylactide, PLA) counted.

The halogen-containing fiber-forming polymers include, for example, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE).

In addition to the filament-forming synthetic polymers already mentioned, there are still other polymers, e.g. Polyacrylates, polyvinyl acetate, polyvinyl alcohol, polycarbonate, polyurethane, polystyrene, polyphenylene sulfide, polysulfone, polyoxymethylene, polyimide or polyurea, which come as a component of the polymer thread of the invention in question.

In further preferred embodiments, the polymer thread in the nonwoven fabric according to the invention may be formed as a mono- or also as a multicomponent filament. The polymer composition of the individual components does not have to be uniform, but is variable within wide limits. In a particularly preferred embodiment, the weight fraction of the filler-containing component, based on the total weight of the multicomponent filament, is greater than 50%.

When using bicomponent filaments, various shapes are available, e.g. Core / coat or side-by-side. Bicomponent filaments of various polyolefins, particularly polypropylene and polyethylene, are particularly preferred.

For the production of polymer filaments, in addition to the use of round fibers, various other cross sections are also suitable. Particularly preferred are monofilaments whose cross-sectional shape is round, oval or n-shaped, where n is greater than or equal to 3, such as trilobal cross-sectional shapes. Also fibers with a hollow cross section come into question.

1. i Vermischen von Polymergranulat mit den Partikeln eines Füllstoffs,
2. ii Extrudieren des Gemisches durch eine oder mehrere Spinndüsen,
3. iii Abziehen des gebildeten Polymerfadens,
4. iv gegebenenfalls Verstrecken und/oder Relaxieren des gebildeten Filaments, und
5. v Aufwickeln des Fadens,

wobei

• der Füllstoffgehalt, bezogen auf den Polymerfaden, > 10 Gewichts-% beträgt, und
• die mittlere Partikelgröße (D₅₀) des Füllstoffs ≤ 6 µm ist.

The polymer threads can be prepared by methods known per se.
Here we work in the following steps:

1. i mixing polymer granules with the particles of a filler,
2. ii extruding the mixture through one or more spinnerets,
3. iii stripping off the formed polymer thread,
4. optionally stretching and / or relaxing the formed filament, and
5. v winding the thread,

in which

• the filler content, based on the polymer thread, is> 10% by weight, and
• the average particle size (D ₅₀ ) of the filler is ≤ 6 μm.

In the production of "spunbonded nonwovens" from synthetic polymers by melt spinning, the polymer melt is forced through pressure holes through orifices and withdrawn in the form of filaments. Conventional melt spinning technologies are described, for example in US 3,692,618 (Metallgesellschaft AG), US5032329 (Reifenhäuser) WO03038174 (BBA Nonwovens, Inc.) or WO02063087 (Ason).
By stretching the drawn filaments, for example by means of compressed air and / or vacuum and / or draw cylinders, the macromolecules are arranged in the filaments, the filament its physical properties (strength, fineness, shrinkage properties) receives. After stretching, the filaments are placed on a tray for further solidification to a nonwoven or cut to the desired length for spinning fiber production (in the literature filaments are sometimes referred to as fibers after drawing, although the filaments have not been cut to length). The consolidation of the filaments in melt spinning can be carried out in a manner known to the person skilled in the art by mechanical processes (mainly needling or hydroentanglement), by heat (welding by application of pressure with simultaneous heating) or by means of chemical methods (bonding agent). As a method for nonwoven production in addition to the preferred melt spinning, for example, the carding process, the meltblown process, the wet-laid process, the electrostatic spinning or aerodynamic nonwoven production process can be used.

1. i Vermischen von Polymergranulat mit den Partikeln eines Füllstoffs,
2. ii Extrudieren des Gemisches durch eine oder mehrere Spinndüsen,
3. iii Abziehen des gebildeten Polymerfadens,
4. iv gegebenenfalls Verstrecken und/oder Relaxieren des gebildeten Filaments, und
5. v Ablage des Fadens zur Vliesstoffherstellung,

wobei

• der Füllstoffgehalt, bezogen auf den Polymerfaden, > 10 Gewichts-% beträgt,
• die mittlere Partikelgröße (D₅₀) des Füllstoffs ≤ 6 µm ist,
• das Flächengewicht zwischen 7 g/m² und 500 g/m²liegt,
• das Produkt aus Flächengewicht und Luftdurchlässigkeit nach DIN EN ISO 9237 im Bereich von 88.000 bis 132.000 ist und
• die Werte für den Quotienten aus Wassersäule nach DIN EN 20811 und Flächengewicht im Bereich von 2,5 ± 0,5 liegen.

The nonwovens according to the invention can likewise be produced by the abovementioned processes. Wherein, before the extrusion of the filament, the addition of the filler takes place in the stated amount and particle size.
Here we work in the following steps:

1. i mixing polymer granules with the particles of a filler,
2. ii extruding the mixture through one or more spinnerets,
3. iii stripping off the formed polymer thread,
4. optionally stretching and / or relaxing the formed filament, and
5. v deposition of the thread for nonwoven production,

in which

• the filler content, based on the polymer thread, is> 10% by weight,
• the average particle size (D ₅₀ ) of the filler is ≦ 6 μm,
• the basis weight is between 7 g / m ² and 500 g / m ² ,
• the product of basis weight and air permeability according to DIN EN ISO 9237 is in the range of 88,000 to 132,000 and
• the values for the quotient of water column according to DIN EN 20811 and basis weight are in the range of 2.5 ± 0.5.

Particular preference is given to using nonwoven fabrics made from polyolefin fibers, in particular from polypropylene fibers and / or polypropylene-polyethylene bicomponent fibers, in particular core sheath fibers with PP core and PE sheath. In addition to a low price, these products are characterized by high stability against chemically aggressive environments.
In a preferred embodiment, the nonwoven fabric consists of a blend of a polymeric thread with a uniform or multiple different natural fiber. Hemp, jute, sisal and tobacco leaves are used as natural fibers.

Further optimization of the nonwoven fabric according to the invention upon its solidification, e.g. By varying temperatures and pressures during thermal consolidation during calendering, it can certainly help to vary the properties of the calcium carbonate filled nonwoven fabrics beyond the scope given herein.

• Flächengewicht von 7 und 500 g/m², vorzugsweise zwischen 10 und 200 g/m².
• Produkt aus Flächengewicht (g/m²) und Luftdurchlässigkeit (1/m²s, nach DIN EN ISO 9237) im Bereich von 110.000 ± 20%.
• Werte für den Quotienten aus Wassersäule (nach DIN EN 20811) und Flächengewicht von 2,5 ± 20%.
• Filamentoberfläche hydrophiliert weist Durchdringungszeiten nach EDANA ERT 150 Werte von weniger als 5 Sekunden auf.
• Werte für den Quotienten aus Höchstzugkraft (nach DIN 29073-3) und Flächengewicht in Maschinen-Richtung von 1,7 ± 20%, sowie in Quer-Richtung von 1,0 ± 20%.
• Werte für den Quotienten aus Höchstzugkraftdehnung (nach DIN 29073-3) und Flächengewicht in Maschinen-Richtung von 3,3 + 20%, sowie in Quer-Richtung von 4,0 ± 20%.
• Filamenttiter im Bereich von 1 bis 5 dtex, vorzugsweise 2 bis 3,5 dtex.

The nonwoven fabric produced according to the invention is more precisely determined by the following parameters within the specified limits:

• Basis weight of 7 and 500 g / m ² , preferably between 10 and 200 g / m ² .
• Product of basis weight (g / m ² ) and air permeability (1 / m ² s, according to DIN EN ISO 9237) in the range of 110,000 ± 20%.
• Values for the quotient of water column (according to DIN EN 20811) and basis weight of 2.5 ± 20%.
• Filament surface hydrophilized has penetration times after EDANA ERT 150 values of less than 5 seconds.
• Values for the quotient of maximum tensile force (according to DIN 29073-3) and basis weight in the machine direction of 1.7 ± 20%, and in the transverse direction of 1.0 ± 20%.
• Values for the quotient of maximum tensile force elongation (according to DIN 29073-3) and basis weight in the machine direction of 3.3 + 20%, and in the transverse direction of 4.0 ± 20%.
• Filament titer in the range of 1 to 5 dtex, preferably 2 to 3.5 dtex.

In the context of the invention are also the many uses of the nonwoven fabric. The most important possible uses for the nonwovens according to the invention are the production of interlining materials, personal hygiene articles (diapers, sanitary napkins, cosmetic pads), cleaning wipes and mop cloths, as well as filters for gases, aerosols and liquids, wound dressings, wound compresses. The production of insulating materials, acoustic nonwovens and roof underlays is conceivable.

The field of application so-called geo-tile is, according to the breadth of the preamble, very comprehensive. For example, geo-tiles are used in the attachment of dykes, as a layer in a green roof construction, as a layer of a landfill cover for the separation of earth layers and bulk solids or as an intermediate layer below the ballast bed of a road surface. Also in agriculture and horticulture the nonwovens are useful as covers for the field and vegetable economy.

Examples

Hereinafter, further details and features of the invention will be explained in more detail with reference to exemplary embodiments. The examples are not intended to limit the invention, but only to illustrate.

Example 1: Nonwovens consisting of monofilaments

On a conventional spunbond pilot plant (Reicofil 3) PP spunbonded nonwovens with different content of calcium carbonate and different basis weight were produced. The calcium carbonate used (Omyalene 102M-OG) is a granulated calcium carbonate, which can be obtained from Omya AG.

As a starting material for the production of nonwovens, a PP prepared using Ziegler-Natta catalysis was selected (ZN-PP: Moplen HP560R, manufacturer Basell), the proposed method is not limited to this type of PP, but are also others plastics suitable for fiber, filament or nonwoven fabric formation, such as, for example, metallocene PP, random and heterophasic propylene copolymers, polyolefin block and copolymer, polyethylenes, polyesters, polyamides, etc.

Table 1 summarizes the composition of the nonwoven fabrics produced as well as selected characteristic properties.

Reference is made to the nonwoven fabric samples 12.1, 17.1 and 20.1 made by melt spinning and made of pure PP monofilaments.

The melt-spun nonwoven samples 12.2, 17.2 and 20.2 were made from monofilaments consisting of a mixture of 90% PP and 10% calcium carbonate.

The melt-spun nonwoven samples 12.3, 17.3 and 20.3 were made from monofilaments consisting of a mixture of 85% PP and 15% calcium carbonate.

The melt-spun nonwoven samples 12.4 and 20.4 were made from monofilaments consisting of a blend of 75% PP and 25% calcium carbonate. <b> Table 1 </ b>. Composition, process conditions, and characteristics of nonwovens made from monofilaments. Pure PP nonwovens Calcium carbonate filled PP nonwovens Sample 12.1 Sample 17.1 Mustor 20.1 Mustor 12.2 Mustor 17.2 Mustor 20.2 Mustor 12.3 Mustor 17.3 Sample 20.3 composition PP 100 100 100 90 90 90 85 85 85 Omxalene 0 0 0 10 10 10 15 15 15 Prozcstemperaturen extruder intake ° C 180 180 180 180 180 180 180 160 180 extruder head ° C 230 230 230 230 230 230 230 230 230 Spinnerell (spinneret) ° C 235 235 235 235 235 235 235 235 235 Kalanderöltemperatur ° C 150 150 150 150 150 150 150 150 150 calender pressure N / mm 70 70 70 70 70 70 70 70 70 filament titres microns 18.1 18.8 19.2 18.3 18.6 19.1 17.3 18.2 19.0 HOURS 1.21 0.64 0.77 0.90 1.00. 0.59 0.77 0.81 0.85 titres dtex 2.4 2.5 2.6 2.9 3.0 3.1 2.8 3.1 3.3 HOURS 0.31 0.17 0.21 0.28 0.31 0.19 12:24 12:27 0.30 Vliesstoffcherakteristik grammage g / m ² 12.1 17.5 20.4 11.7 16.8 21.4 11.9 17.5 22.1 HOURS 0.66 0.80 0.56 0.59 0.51 0.67 0.40 0.57 0.63 web thickness microns 216.0 279.0 312; 5 216.5 270 303.0 204 269.0 303.5 HOURS 12.4 10.7 11.8 20.0 9.3 17.6 16.2 13.5 10.0 fleece density g / cm ³ 0.056 0.063 0,065 0054 0.062 0,071 0.058 0,055 0.073 HOURS - - - - - - - - - Splitting of the nonwovens Medium pore microns - 113 114 164th 121 103 - 125 115 HOURS - 3.4 13.1 15.8 2.5 8.3 - 6.4 7.0 Air permeability 1 / m ² s 8-880 6610 5763 9090 6950 5932 9470 7010 5530 HOURS 537 409 361 644 489 433 878 546 378 water column cm 5.5 6.7 8.4 4.4 6.8 8.9 3.6 6.9 9.0 HOURS 0.8 1.0 1.2 0.8. 0.6 0.6 0.8 0.7 0.9 Mechanical nonwovens property Maximum pull MD N / 5mm 18.5 31.9 40.6 18.7 27.2 35.2 16.8 25.4 34.0 HOURS 3.18 1.85 2.72 2.37 2.22 1.85 1.79 2.88 3.21 Maximum tensile strength CD N / 5mm 12.3 21.3 25.8 10.5 18.8 23.8 9.2 16.0 21.8 HOURS 1.57 1.39 2.37 0.99 1.42 2.44 1.86 2.48 1.90 Maximum tensile strength MD % 41.5 60.6 64.6 47.3 57.1 57.4 46.9 56.6 59.7 HOURS 10.35 7.08 6.90 9.56 7.09 6.11 5.52 8.95 9:07 Maximum tensile force CO % 54.1 64.8 67.0 64.5 66.8 68.0 60.3 59.9 65.1 HOURS 8.66 7.85 6.82 8.14 7.36 9.37 i 13,89 8.43 6.61 wettability Penetration HOURS 4.3 - 3.1 3.5 - 3.8 - - - Pattern 17.4 Pattern 20.4 composition 75 75 PP Omyalene 25 25 process temperatures extruder intake ° C 180 180 extruder head ° C 230 230 spinnerette ° C 235 235 Kalanderöltemperatur ° C 150 150 calender pressure N / mm 70 70 Filamentelgenschaften Tiler microns 19.0 19.0 HOURS 1.3 1.3 Tiler dtex 3.8 3.8 HOURS 0,052 0,052 Nonwoven characteristics grammage g / m ² 16.7 20.0 HOURS 0.5 0.63 web thickness microns 253.5 287.0 HOURS 9.1 9.5 fleece density g / cm ³ 0.66 0.70 HOURS - - Barrier properties of the nonwovens 143 131 Medium pore microns 0.4 12.6 HOURS 7,730 6,650 Luftdurchlalsslgkeit I / m ² s 412 250 HOURS 7.0 8.2 water column cm 0.4 1.3 HOURS Mechanical nonwovens property 29.6 35.7 Maximum pull MD N / 5mm 2.32 2.57 HOURS 16.7 20.4 Maximum tensile strength CD N / 5mm 1.97 1.11 HOURS 63.4 70.4 Maximum tensile strain CD % 9.15 9.14 HOURS 73.3 73.9 Maximum tensile strain CD % 9.32 4.75 HOURS

Example 2 Nonwovens consisting of bicomponent fibers

Since other fiber forms are conceivable in addition to the method presented here, multicomponent fibers were also spun for the production of nonwovens in which the calcium carbonate is not distributed throughout the fiber, but only in individual fiber components.

As examples, nonwovens of core / sheath bicomponent fibers were prepared.

Table 2 summarizes the composition and its characteristics.

The melt-spun nonwoven samples 12.1B and 20.1B are made of pure PP bicomponent filaments having a core / sheath ratio of 50/50 and are intended as a reference.

The melt-spun nonwoven samples 12.2B and 20.2B consist of PP bicomponent filaments in which the core of the filaments consists of a blend of 90% PP and 10% calcium carbonate and the sheath of pure PP. The core / shell ratio was 75/25. Based on the total fiber, the content of calcium carbonate is about 7.5%.

The melt-spun nonwoven samples 12.3B and 20.3B are made of PP bicomponent filaments in which both the core and the sheath of the filaments are a mixture of 90% PP and 10% calcium carbonate. The core / shell ratio was 50/50. Based on the total fiber, the content of calcium carbonate is about 5%.

The melt-spun nonwoven fabric sample 20.4B consists of PP bicomponent filaments in which the core of the filaments consists of a mixture of 75% PP and 25% calcium carbonate and the sheath of pure PP. The core / shell ratio was 50/50. Based on the total fiber, the content of calcium carbonate is about 12.5%.

The melt-spun nonwoven fabric sample 20.5B consists of PP bicomponent filaments in which the core of the filaments consists of a blend of 75% PP and 25% calcium carbonate and the sheath of pure PP. The core / shell ratio was 75/25. Based on the total fiber, the content of calcium carbonate is about 18.75%.

It is understood that the blends for producing the nonwoven fabrics may contain, in addition to the specified formulations, other additives or blends, in particular titanium dioxide or pigments. <b> Table 2. </ b> Composition, process conditions, and characteristics of nonwoven fabrics made from bicomponent fibers. Pure PP nonwovens Nonwoven fabrics filled with calcium carbonate Sample 12.1 B Sample 20.1B Pattern 12.2B Sample 20.2B Pattern 12.3B Sample 20.3B Pattern 20.4B Pattern 20.5B Sheath / core ratio 50/60 50/60 25/75 25/75 50/50 50/50 50/50 25/75 Grain composition PP 100 100 90 90 90 90 75 75 Omyalene 0 0 10 10 10 10 25 25 Coat composition PP 100 100 100 100 90 90 100 100 Omyalene 0 0 0 0 10 10 0 0 Prozesstamperatur Extruder 1st zone ° C 180 160 180 180 180 180 180 180 Exdruderkopf ° C 230 230 230 230 230 230 230 230 spinneret ° C 235 235 235 235 235 235 235 235 Kalanderöltemperatur ° C 150 150 150 150 150 150 150 150 Calendar roll pressure N / mm 70 70 70 70 70 70 70 70 Filamenteigenschahen titres microns 16.9 16.5 17.3 17.3 17.1 17.1 17.1 17.0 Tiler HOURS 0.41 0.90 0.93 0.47 1.05 1.15 12:38 12:57 dtex 2.0 1.9 2.4 2.4 2.4 2.4 2.6 2.8 HOURS 0.10 12:21 0.25 0.13 0.28 0.32 0.12 0.19 web formation basis weight g / m ² 12.3 20.1 12.4 20.6 13.1 21.0 19.5 20.3 HOURS 0.39 0.67 0.49 12:48 0.33 0.56 0.96 1.08 Barriersigenschaften Luflpermeabilität I / m ² s 7760 5017 7988 5241 7564 5017 5492 5166 HOURS 468 270 321 471 467 294 445 313 Mechanical properties F max MD N / 5mm 19.4 44.7 15.9 34.9 18.7 35.9 43.4 43.2 HOURS 1.46 3.68 1.89 2.39 1.69 3.45 2.20 5.28 F max CD N / 5mm 13.4 31.8 12.3 26.0 13.9 25.7 29.0 30.7 HOURS 1.30 4.22 1.95 3.52 1.48 2.26 2.26 2.60 Elongation MD % 37.7 66.2 39.6 53.3 42.0 59.2 64.5 63.5 HOURS 6.08 6.03 7.83 7.82 3.83 9.43 6.79 11.54 Elongation CD % 50.6 70.6 52.3 66.7 55.1 64.5 68.8 64.8 HOURS 4.70 7.37 11.29 11.25 5.20 7.69 4.99 8.94

The results in Tables 1 and 2 show that, surprisingly, the addition of the calcium carbonate does not cause a significant change in the characteristic nonwoven properties.

Example 3: Hydrophilicity after Ftillstoffzugabe

Nonwovens used for personal care products (e.g., diapers) are typically rendered hydrophilic. For example, the hydrophilizing agent Nuwet 237 from GE SILOCONES can be used for this purpose.

For testing the hydrophilicity as a function of the content of calcium carbonate, both pure PP nonwovens and those with a calcium carbonate content of 10% and a weight per unit area of 12 g / m ² and 20 g / m ^{2 were} obtained by a formulation consisting of 7.5% Nuwet 237 in water, hydrophilized by kiss roll application. The amount of active substance applied in this way was about 0.2% based on the weight of the web.

Penetration times of 4.3 seconds (12 g / m ² ) and 3.1 seconds (20 g / m ² ), respectively, were measured for the non-calcium carbonate hydrophilized nonwoven fabrics. Penetration times of 3.5 seconds (12 g / m ² ) and 3.8 seconds (20 g / m ² ) were measured for the hydrophilized nonwoven fabrics containing 10% calcium carbonate.

It was thus shown that the addition of 10% calcium carbonate has no significant influence on the hydrophilic properties.

methods Determination of filament titer

The filament titer was determined by means of a microscope. The conversion of the measured titer (in microns) into Dezitex was made according to the following formula (density PP = 0.91 g / cm ³ ): $${\left(\frac{{\mathit{titres}}_{\mathit{microns}}}{2}\right)}^2\cdot \pi \cdot \rho \left[\frac{G}{{\mathit{cm}}^3}\right]\cdot 0.01={\mathit{titres}}_{\mathit{dtex}}\left[\frac{G}{{10}^{4}m}\right]$$

Determination of the surface weight

The basis weight determination was carried out according to DIN EN 29073-1 on 10 x 10 cm specimens.

The nonwoven fabric thickness was measured as the distance between two plane-parallel measuring surfaces of a certain size, between which the nonwovens are below a predetermined measuring pressure. The method was carried out analogously to DIN EN ISO 9073-2. Application weight 125 g, measuring surface 25 cm ² , measuring pressure 5 g / cm ²

Determination of mean pore size

The average pore size of the nonwovens was determined by means of a capillary flow porometer (PMI Capillary Flow Porometer CFP-34RUF8A-3-X-M2T). In the process, a sample saturated with a special liquid is exposed in the porometer to a continuously increasing air pressure, and the dependence on air pressure and air flow is measured.

Determination of air permeability

The measurement of the air permeability was carried out according to DIN EN ISO 9237. The surface of the measuring head was 20 cm ² , the applied test pressure 200 Pa.

Determination of the water column

The determination of the water column was carried out in accordance with DIN EN 20811. Gradient of the test pressure 10 mbar / min. As a measure of the watertightness of the water pressure in mbar or mm water column is specified, in which penetrates at the third point of the test area of the first drop of water through the test material.

Determination of mechanical properties

The mechanical properties of the nonwovens were determined according to DIN EN 29073-3. Clamping length: 100mm, sample width 50mm, feed 200mm / min. "Maximum tensile force" is the maximum force reached when passing through the force-strain curve, "Maximum tensile strain" is the strain in the force-strain curve associated with the maximum tensile force.

Determination of hydrophilicity

The penetration times of the hydrophilized nonwovens ("liquid strike through time") were measured according to EDANA ERT 150.

Claims (15)

1. A non-woven fabric of polymer threads containing a thermoplastic polymer and an inorganic filler, wherein

   - the filler content, relative to the polymer thread, amounts to > 10 % by weight,
   characterized in that

   - the average particle size (D₅₀ ) of the filler is ≤ 6 µm,

   - the mass per unit area is between 7 g/m² and 500 g/m²,

   - the product of the mass per unit area and the air permeability in accordance with DIN EN ISO 9237 is in the range of from 88,000 to 132,000, and

   - the values for the quotient of the head of water In accordance with DIN EN 20811 and the mass per unit area are in the range of 2·5 ± 0·5.
2. A non-woven fabric of polymer threads according to Claim 1, characterized in that the filler is an alkaline-earth carbonate.
3. A non-woven fabric of polymer threads according to one of Claims 1 and 2, characterized in that the filler consists of up to at least 90 % by weight, preferably 95 % by weight, and more particularly 97 % by weight, of calcium carbonate.
4. A non-woven fabric of polymer threads according to any one of the preceding Claims, characterized in that the filler does not contain titanium dioxide,
5. A non-woven fabric of polymer threads according to any one of the preceding Claims, characterized in that the filler content, relative to the polymer thread, amounts to between 1 and 25 % by weight.
6. A non-woven fabric of polymer threads according to any one of the preceding Claims, characterized in that the top out of the filler particles (D₉₈ ) amounts to ≤ 10 µm.
7. A non-woven fabric of polymer threads according to any one of the preceding Claims, characterized in that the average particle size of the filler (D₅₀ ) preferably amounts to between 2 µm and 6 µm.
8. A non-woven fabric of polymer threads according to anyone of the preceding Claims, characterised in that the polymer is a polyolefin, polyester, polyamide, polyphenylene sulphide or a halogen-containing polymer.
9. A non-woven fabric of polymer threads according to Claim 8, characterized in that the polyolefin is a polyethylene, polypropylene, poly(1-butene), polyisobutylene, poly(1-pentene), poly(4-methylpent-1-ene), polybutadiene, polyisoprene or a mixture of two or more of the said compounds.
10. A non-woven fabric of polymer threads according to any one of the preceding Claims, characterized in that the polymer thread is a monofilament or a multi-component filament, wherein in the case of the multi-component filament all the components of the filament consist either of the same polymer composition or of different polymer compositions.
11. A non-woven fabric of polymer threads recording to Claim 1 characterized in that the multi-component filament is a sheath/core bi-component filament or a bi-component filament designed in the form of a side-to-side filament, wherein the filler is contained in only one component in each case.
12. A non-woven fabric of polymer threads according to Claim 11, characterized in that the proportion by weight of the component of the filament containing the filler, relative to the weight of the multi-component filament, is > 50 % by weight.
13. A non-woven fabric of polymer threads according to any one of the preceding Claims, characterized in that the polymer thread has different cross-sections, in particular a hollow-shaped cross-section or a trilobate cross-section.
14. A non-woven fabric according to any one of the preceding Claims I to 13, characterized in that the non-woven fabric consists of the mixture of a polymer thread with a uniform natural fibre or a plurality of different natural fibres.
15. Use of the non-woven fabric according to any one of the preceding Claims 1 to 13 for the production of

    - articles of personal hygiene (nappies, sanitary towels, cosmetic pads),

    - cleaning cloths, wipes, mop cloths,

    - filters for example for gases, aerosols and liquids,

    - medical dressings, wound compresses,

    - sound-proofing materials, acoustic non-woven-fabric substances,

    - inlay materials,

    - roof-lining strips,

    - non-woven geo-fabrics, or of

    - coverings for field cultivation and vegetable cultivation.