KR101965471B1 - Thermoplastic fibres with reduced surface tension - Google Patents

Abstract

The present invention relates to a process for the production of thermoplastic fibers having reduced surface tension, in which the thermoplastic material to be used is mixed with a copolymer made up of at least one alpha-olefin and at least one acrylic acid ester or methacrylic acid ester of an aliphatic alcohol, and To a product made according to a melt-spinning process from thermoplastic fibers having these reduced surface tensions.

Description

[0001] THERMOPLASTIC FIBERS WITH REDUCED SURFACE TENSION [0002]

The present invention relates to a process for the production of a thermoplastic material having a reduced surface tension which mixes the thermoplastic material to be used with one or more alpha-olefins and a copolymer of one or more acrylic acid or methacrylic acid esters of an aliphatic alcohol, preferably 2-ethylhexanol. To a process for producing thermoplastic fibers and also to products obtainable by melt-spinning processes from thermoplastic fibers having these reduced surface tensions.

The products obtained from the thermoplastic fibers from the group of polyamides or polyesters within the meaning of the present invention can be obtained from fibrous nonwoven webs, nonwoven fabrics, woven fabrics, threads, yarns, ropes, felt, drawn- Non-crimp fabric, or formed-loop knit. Fibrous nonwoven webs or nonwoven fabrics are the preferred products within the meaning of the present invention. Fibrous nonwoven webs consist of loosely agglomerated fibers that must still be bonded together. The strength of the fibrous nonwoven web is based solely on the inherent adhesion of the fibers. However, the latter can be influenced by post-processing. Since a fibrous nonwoven web can be processed and used, it needs to be consolidated, and various methods can be used for this purpose. Only a consolidated fibrous nonwoven web should be referred to as nonwoven. This distinction is not made in spoken languages.

The nonwoven is fundamentally different from the woven fabric, the draw-loop knit, the non-crimp fabric and the foam-loop knit, which is characterized by laying the individual fibers or threads in a manner determined by the manufacturing process. Nonwovens, on the other hand, consist of fibers whose position control can only be explained by statistical methods.

The fibers in the nonwoven are randomly arranged with respect to each other. The nonwoven is particularly classified according to the fibrous material (for example, a polymer in the case of manufactured fibers), the bonding method, the fiber type (staple fiber or continuous-filament fiber), the fiber fineness and the fiber orientation. The fibers may be deposited in a predetermined manner in one preferred direction, or they may be in a completely stochastic orientation state as in the case of a random-laid nonwoven fabric.

If the fibers do not have a preferential orientation in their alignment (orientation), an isotropic nonwoven is considered. If the fibers are placed more frequently in one direction than in the other, this is termed anisotropy.

Thus, the nonwoven is a textile fabric, wherein the fabric formation is carried out by deposition of fibers and subsequent fixation, rather than by weaving, foam-loop knitting, draw-loop knitting or some laying. Non-woven fabrics continue to have annual growth rates, due to their diversity of applications and their relatively low manufacturing costs, compared to weaving and loop-drawing knitting fabrics.

The advantages of the nonwoven are high specific surface area, and the manufacturing method enables a great range of changes in density, fiber size, pore size or thickness, which provides a considerable degree of isotropy in the fragments. These advantageous properties are useful as sanitary products, in particular for medical purposes such as surgical drapes, sheets, wound covers and gauzes, as wipes of any kind for household use, as decorative linen, in particular as tablecloths or napkins, (WO 2009/103537 Al) for technical applications, in particular insulating mats, covering mats or as filter media (e.g. oil filters) in the engine / automotive sector or as separators in batteries.

Reduced surface tension plays a crucial role in most of these applications in that it can provide, for example, increasingly greater water repellency behavior, which plays an important role not only in the clothing industry but also in applications in the filter media in the automotive sector can do.

The fabrication of spunbonded nonwoven fabrics constitutes a direct combination between the spinning process and the web forming process. The wet-spinning process as well as the melt-spinning and dry-spinning processes are suitable for forming webs based on continuous-filament fibers. A number of fiber-forming polymers are known as starting materials for nonwovens. The continuous-based nonwoven fabrics of the present invention are made from thermoplastic polymers from the group of polyamides or polyesters, for example by melt-spinning (such as so-called meltblown nonwoven). The melt spinning process is described, for example, in EP 0 880 988 A1 or EP 1 473 070 A1 for polyesters. Polyester nonwoven fabrics are described in EP 2 090 682 A1 or EP 2 092 921 A1. The use of polyester nonwovens made by the meltblown process as filter media forms part of the claimed subject matter of EP 0 466 381 B1.

Thermoplastic fibers formed from polyolefins, for example polypropylene or polyethylene fibers, have relatively low surface tension due to the inherent hydrophobic nature of the polyolefin without the aid, but in relatively more polar thermoplastics, preferably polyamides and polyesters High surface tension is considered. Despite the need for low surface tension, relatively high-value polymers such as polyamides or polyesters have to be used (for example due to insufficient heat resistance or chemical resistance in the part of the polyolefin) . This is often the case with relatively more polar thermoplastics, such as polyamides and polyamides, with the intention of achieving lower surface tension while maintaining the familiar advantages of, for example, heat resistance, mechanical robustness and chemical resistance to oils and automotive fuels. It is embodied as a desire to modify the polyester.

DE 19 937 729 A1 describes, for example, the breaking strength with polyester, which influences the properties of the thermoplastic fibers emitted by the addition to the thermoplastic material used. Wherein the additive is a copolyester containing, in particular, acrylic acid esters or methacrylic acid esters as monomer units. WO 2005/040257 A1 seeks a similar purpose in using ethylene-alkyl acrylate copolymers to improve their mechanical properties, for example tensile strength, in polyester films, tapes and melt-spun fibers. Here, it is mentioned that addition of more than 5% of the copolymer is desirable.

FR-OS 239 746 and US 3,378,609 describe the entanglement and hydrophobization of polyester-based wovens by applying an aqueous emulsion of fluorinated polymer to the finished fabric. EP 0 196 759 A1 describes the hydrophobicity of individual polyester fibers by providing a polyester fiber with a water-repellent and oil repellent agent based on polyoxyalkylene glycols and fluorine having substantially no reactivity with the polyester.

WO 2009/152349 A1 discloses sanitary fabrics finished with a fluoro compound based on a perfluorinated alkyl group having up to 4 carbon atoms as repellent additives. Copolymers of such perfluorinated materials with acrylate esters or methacrylate esters are mentioned by way of example. JP 2003 193331 A discloses rubber reinforced polyester monofilaments which have been finished, in particular, using copolymers of ethylene and glycidyl methacrylate.

WO 2005/087868 A1 discloses a process for the preparation of an E / X / Y copolymer, obtained by a melt-spinning process, wherein E represents ethylene, X represents in particular an alkyl acrylate, Y is in particular glycidyl acrylate, Glycidyl methacrylate, or glycidyl vinyl ether). The ethylene copolymer modified polyamide product can be a fiber that has been finished using a polypropylene glycol, glycidyl methacrylate, or glycidyl vinyl ether.

Finally, WO 2008/083820 A1 discloses a polyamide or polyester based soft yarn which can be finished using a polymer of a softer ethylene alkyl acrylate. Methyl acrylate, ethyl acrylate and butyl acrylate are described.

Both of these prior art solutions have the disadvantage that the surface tension change which provides the oil and water repellency behavior is subsequently realized only in the further process step of applying the auxiliaries to the fabric in each case. Subsequent application to the surface involves elevated process complexity as well as elevated adjuvant desorption or cleaning agent risks, which not only undermines the desired surface effect but also causes contamination of the problematic environment, In some cases it may be associated with contamination of the filtrate. It is also often necessary to rely on fluorinated chemicals which, in addition to being very expensive, also require special consideration for possible toxicity, for example with regard to recovery by incineration.

Thus, the problem addressed by the present invention is to pre-modify the polyamide / polyester so that surface tension reduction is possible without the post-treatment of the product made from the thermoplastic fibers in question and this is achieved by the use of very few materials. Also, the reforming should avoid fluorinated chemical, color must be neutral, and fiber formation itself should not be unacceptably damaged. Modification for surface tension reduction should also be such that the adjuvants added can be limited by their effectiveness to the level of use where there is no decisive effect on the melt-spinning process, if any. The fibers thus obtained should be further processable in a variety of ways with reduced surface tension, in particular fibrous nonwoven webs, nonwoven fabrics, woven fabrics, draw-loop knits, non-crimped fabrics or foam- do.

The solution to the problem and the object of the present invention is to provide a thermoplastic material which is characterized in that the thermoplastic material comprises an? -Olefin and an unsubstituted aliphatic alcohol, preferably an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms, more preferably 2-ethylhexane Characterized in that at least one E / X copolymer of methacrylic acid or acrylic acid ester is added and then the mixture is spun by a melt-spinning process, preferably the surface tension of the thermoplastic material-based fibers or filaments .

Surprisingly, the addition of E / X copolymers used according to the invention to thermoplastic polyamides or polyesters is very effective in reducing the surface tension of the corresponding thermoplastic fibers and their derivatives, For example, it has been found that it provides a water-repellent finishing treatment for thermoplastic-based fibers, preferably polyamide / polyester fibers, and derivatives thereof. The copolymers used in accordance with the present invention are very effective in that a significant reduction in surface tension is achieved even at very low concentrations and, therefore, there is no definitive effect on melt spinning, if any.

In the method,

99.9 to 10 parts by weight, preferably 99.5 to 40 parts by weight, and more preferably 99.0 to 55 parts by weight of at least one thermoplastic material and

0.1 to 20 parts by weight, preferably 0.25 to 15 parts by weight, more preferably 0.5 to 10 parts by weight, still more preferably 0.75 to 6 parts by weight, most preferably 1.0 to 2.0% by weight, E / X copolymer

Is used.

Fibers based on thermoplastic polymers from the group of polyamides or polyesters are preferred for use as fibers on thermoplastic materials.

Fibers based on aliphatic polyamides are particularly preferred for use as fibers based on thermoplastics from the group of polyamides.

Polyalkylene terephthalate-based fibers are particularly preferred for use as thermoplastic material-based fibers from the group of polyesters.

The thermoplastic polyamide emitted according to the present invention can be obtained in a variety of ways and can be synthesized from a wide variety of building blocks. In specific application scenarios, they are used alone or in combination with processing aids, stabilizers, polymer alloy partners, especially elastomers. A blend with some other polymer, preferably a blend with polyethylene, polypropylene or ABS, is also suitable, in which case optionally one or more compatibilizers may be used. The properties of the polyamides can be improved, for example, by the mixture of the elastomers with respect to the breaking strength, for example against the breaking strength of low-viscosity polyamides. Many possible combinations provide a very large number of products with very wide variety of properties.

The polyamides can be prepared according to a number of existing procedures, including using various monomer building blocks, various chain transfer agents to achieve target molecular weights, or other monomers having reactive groups for the intended post- ≪ / RTI >

Industrial related processes for the production of polyamides typically proceed by polycondensation in the melt. In this connection, polycondensation also involves hydrolytic polymerization of lactam.

Preferred polyamides (PA) are partially crystalline polyamides obtainable from lactam or corresponding amino acids with diamines and dicarboxylic acids and / or 5 or more ring sources.

Possible starting materials are aliphatic and / or aromatic dicarboxylic acids such as adipic acid, 2,2,4-trimethyladipic acid, 2,4,4-trimethyladipic acid, azelaic acid, sebacic acid, isophthalic acid, Terephthalic acid, aliphatic and / or aromatic diamines such as tetramethylenediamine, hexamethylenediamine, 1,9-nonanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, isomer diamino Dicyclohexylmethane, diaminodicyclohexylpropane, bisaminomethylcyclohexane, phenylenediamine, xylylenediamine, aminocarboxylic acid such as aminocaproic acid, and the corresponding lactam. Also included are copolyamides of two or more of the mentioned monomers.

The use of caprolactam is particularly preferred, and the use of epsilon -caprolactam is very particularly preferred.

Particularly suitable are most molding compounds based on nylon-6, nylon-6,6 and other aliphatic and / or aromatic polyamides / copolyamides and having from 3 to 11 methylene groups per polyamide group in the polymer chain Further expanded.

The polyamide obtained according to the invention may be used in admixture with other polyamides and / or further polymers.

The polyamide may comprise a mixture of conventional additives such as, for example, release agents, stabilizers and / or flow aids.

The thermoplastic polyester which is radiated according to the invention is particularly preferably a partially aromatic polyester.

Particularly preferred radiating polyesters are selected from the group of derivatives of polyalkylene terephthalate. Very particularly preferred radially polymerized polyesters are polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate, more preferably polybutylene terephthalate and polyethylene terephthalate, most preferably polybutylene terephthalate, Terephthalate. ≪ / RTI >

The partially aromatic polyester is a material containing an aromatic moiety as well as an aliphatic moiety.

For purposes of the present invention, polyalkylene terephthalates are reaction products of aromatic dicarboxylic acids or reactive derivatives thereof, especially dimethyl esters or anhydrides, and aliphatic, cycloaliphatic or aromatic aliphatic diols and mixtures of these reactants.

Preferred polyalkylene terephthalates are obtainable by known methods from terephthalic acid (or a reactive derivative thereof) and aliphatic or cycloaliphatic diols having from 2 to 10 carbon atoms (Kunststoff-Handbuch, vol. VIII, p. 695 FF, Karl-Hanser-Verlag, Munich 1973).

The preferred polyalkylene terephthalate comprises 80 mol% or more, preferably 90 mol% or more, based on the dicarboxylic acid, of at least 80 mol%, preferably at least 90 mol%, based on the terephthalate radical and the diol component Glycol and / or 1,3-propanediol and / or 1,4-butanediol radical.

Preferred polyalkylene terephthalates are, in addition to terephthalic acid radicals, radicals of other aromatic dicarboxylic acids having 8 to 14 carbon atoms up to 20 mol% or radicals of aliphatic dicarboxylic acids having 4 to 12 carbon atoms, In particular, it is possible to use a phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-biphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid, It may contain a radical of a carboxylic acid.

Preferred polyalkylene terephthalates include, in addition to the ethylene / 1,3-propanediol / 1,4-butanediol glycol radical, 20 mol% or less of other aliphatic diols having 3 to 12 carbon atoms or 6 to 21 carbon atoms Such as 1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol Methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,6- 1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 2,5-hexanediol, 1,4-di (beta -hydroxyethoxy) benzene, 2,2-bis (4-hydroxycyclohexyl) propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2- Phenyl) propane or 2,2-bis (4-hydroxypropoxyphenyl) propane (DE-A 25 07 674 (= US 4 086 212), DE-A 25 07 776, DE -A 27 15 932 (= US 4 176 224)).

The polyalkylene terephthalate can be prepared by reacting a relatively small amount of a trivalent or tetravalent alcohol or a mixture of trivalent or tetravalent carboxylic acids, as described for example in DE-A 19 00 270 (= US-A 3 692 744) Lt; / RTI > Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylol ethane, trimethylol propane and pentaerythritol.

It is not desirable to use a branching agent in excess of 1 mol% based on the acid component.

Particularly preferred are only the polyalkylene terephthalates formed from terephthalic acid and its reactive derivatives, especially the dialkyl esters thereof, and ethylene glycol and / or 1,3-propanediol and / or 1,4-butanediol, in particular polyethylene terephthalate and poly Butylene terephthalate, and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates further comprise a copolyester formed from two or more of the above-mentioned acid components and / or from two or more of the above-mentioned alcohol components, particularly preferred copolyesters are poly (ethylene glycol / 1,4-butanediol) terephthalate.

The polyalkylene terephthalate generally has an intrinsic viscosity of from about 0.3 dl / g to 1.5 cm3 / g, preferably from 0.4 dl / g to 1.3 dl / g, more preferably from 0.5 dl / g to 1.0 dl / g, Measured in 1: 1 (w / w) phenol / o-dichlorobenzene at 25 < 0 > C).

The thermoplastic polyester which is preferably radiated according to the invention may be used in admixture with other polyesters and / or further polymers. Very particular preference is given to using polyethylene terephthalate (PET), polypropylene terephthalate or polybutylene terephthalate (PBT) or mixtures thereof, in particular polybutylene terephthalate.

Recycled polyesters from post-consumer or pre-consumer recycles may also be used alone or in combination, in which case polyester recycles from bottles, so-called PET copolyesters, are preferred. Their example is Germany beret Salle Hebrews - represented by over tipen Bach PET material Kunst Stoke-free cycling geem beha (PET Kunststoffrecycling GmbH) PET PLUS (PET Plus) 80 ^® from.

Up to 15 mol% of other dicarboxylic acids and / or diols, especially isophthalic acid, adipic acid, diethylene glycol, polyethylene glycol, 1,4-cyclohexanedimethanol, or any other C _2-4 alkylene glycol (C _2-4 alkylene) terephthalates are particularly preferred for use as polyesters in melt spinning. Polyethylene terephthalate having an intrinsic viscosity (IV) in the range of 0.5 to 1.4 dl / g, polypropylene terephthalate having an IV of 0.7 to 1.6 dl / g or polybutylene terephthalate having an IV of 0.5 to 1.8 dl / g Polyethylene terephthalate having an intrinsic viscosity (IV) in the range of 0.6 to 1.0 dl / g or polybutylene terephthalate having an IV of 0.6 to 0.9 dl / g is particularly preferred.

The thermoplastic material emitted according to the present invention contains an E / X copolymer of methacrylic acid or acrylic acid ester X of at least one? -Olefin E and an unsubstituted aliphatic alcohol to reduce its surface tension. Alpha-olefins suitable for use as component E of the copolymer preferably have from 2 to 10 carbon atoms, which may be unsubstituted or substituted with one or more aliphatic, cycloaliphatic or aromatic groups. Preferred? -Olefins are selected from the group comprising ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-octene and 3-methyl-1-pentene. Particularly preferred? -Olefins are ethene and propene, and ethene is very particularly preferred. Mixtures of the -olefins described are also suitable.

The? -Olefin content of the E / X copolymer is 50 to 90 wt%, preferably 55 to 75 wt%.

The E / X copolymer is also defined by a second component in addition to the alpha -olefin. Wherein the alkyl or arylalkyl groups are formed from 5 to 30 carbon atoms and contain, even if present, only reactive functional groups from the group comprising minimal concentrations of epoxide, oxetane, anhydride, imide, aziridine, furan, Alkyl or arylalkyl esters of acrylic acid or methacrylic acid are suitable for use as the second component. The alkyl or arylalkyl groups may be linear or branched, and may also contain cycloaliphatic or aromatic groups, which are also substituted with one or more ether or thioether functional groups. Suitable methacrylic or acrylic esters in this connection also include those synthesized from alcohol components based on oligoethylene glycol or oligo propylene glycol having only one hydroxyl group and up to 30 carbon atoms.

The alkyl or arylalkyl groups of the methacrylic acid or the acrylic acid ester are preferably 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl, 3-heptyl, Nonyl, 1-decyl, 1-dodecyl, 1-lauryl or 1-octadecyl. Particularly preferred are unsubstituted alkyl or arylalkyl groups having 6 to 20 carbon atoms, more preferably 8 to 20 carbon atoms. Also particularly preferred are branched alkyl groups, which provide a lower glass transition temperature T _G than linear alkyl groups having the same number of carbon atoms.

Copolymers in which an alpha -olefin is copolymerized with 2-ethylhexyl acrylate are particularly preferred for the purposes of the present invention.

Mixtures of the acrylic acids or methacrylic acid esters described are also suitable.

The acrylic acid or methacrylic acid ester content of the copolymer is in the range of 10 to 50 wt%, preferably 25 to 45 wt%.

A particularly suitable copolymer is selected from the group of possible materials available from ahreuke town (Arkema) under the trade name Lot reel (Lotryl) ^® EH, some of these are also hot-melt adhesive is used as the.

Thus, a particularly preferred embodiment of the present invention relates to a process for the preparation of ethylene esters of acrylic esters of ethylene and unsubstituted aliphatic alcohols having 6 to 30 carbon atoms, preferably ethylene E and acrylic ester X having 6 to 20 carbon atoms, Characterized in that an E / X copolymer of ethylene E and 2-ethylhexyl acrylate X is preferably added to the thermoplastic material and then the mixture is spun by a melt-spinning process. Thereby reducing the surface tension of the fibers of the substrate.

Thus, a particularly preferred embodiment of the present invention relates to a process for the preparation of ethylene esters of acrylic esters of ethylene and unsubstituted aliphatic alcohols having 6 to 30 carbon atoms, preferably ethylene E and acrylic ester X having 6 to 20 carbon atoms, Characterized in that an E / X copolymer of ethylene E and 2-ethylhexyl acrylate X is added to the thermoplastic material and the mixture is then spun by a melt-spinning process. .

Thus, a particularly preferred embodiment of the present invention relates to a process for the preparation of ethylene esters of acrylic esters of ethylene and unsubstituted aliphatic alcohols having 6 to 30 carbon atoms, preferably ethylene E and acrylic ester X having 6 to 20 carbon atoms, Characterized in that an E / X copolymer of ethylene E and 2-ethylhexyl acrylate X is preferably added to the thermoplastic material and the mixture is then spun by a melt-spinning process. . The amount of copolymer added to the polyamide / polyester blend to be processed by spinning is specified, for example, above, and appears to be sufficient in most cases if it is? 6 wt%. The concentration of the copolymer is preferably in the range of 0.75 to 6.0 wt%, depending on the take-off speed (> 700-1500 m / min) Lt; / RTI > This type of fiber birefringence allows for a 5: 1 draw ratio and ensures the desired high thread toughness at a take-up speed well above 3800 m / min regardless of the spin take-off speed of less than 1500 m / min.

It is possible to safely add conventional additives, preferably dyes, additional hydrophobing agents, quenching agents, stabilizers, antistatic agents, lubricants, and branching agents to the thermoplastic material-copolymer mixture of the present invention in an amount of 0.001 to 5.0 wt% .

Dyes which can preferably be used are those based on disperse dyes, in particular on azo dyes or on highly finely divided carbon blacks.

The quencher, which can be preferably used, is a microcrystalline anatase having an average particle size [d50] of 0.25 to 0.35 mu m, which may also have an organic or inorganic surface treatment.

Stabilizers which can preferably be used are, for example, aromatic polycarbodiimides such as Stabaxol P from Rheinchemie, Mannheim, Germany, as well as heat stabilizers based on organic phosphite derivatives .

Antistatic agents which can preferably be used are, in particular, finely divided conductive-grade carbon black or carbon nanotubes.

Lubricants which can preferably be used are in particular long chain fatty acids, preferably stearic acid or behenic acid, salts thereof, preferably calcium stearate or zinc stearate, and also ester derivatives thereof, and also low molecular weight polyethylene waxes And / or polypropylene wax. Within the meaning of the present invention, the Montan wax is a mixture of straight-chain saturated carboxylic acids having a chain length of from 28 to 32 carbon atoms. Preferred lubricants and / or release agents are selected from the group of low molecular weight polyethylene waxes and also amides or esters of saturated or unsaturated aliphatic carboxylic acids having 8 to 40 carbon atoms and aliphatic saturated amines or alcohols having 2 to 40 carbon atoms ≪ / RTI > For the purposes of the present invention, ethylene bisstearyl amide and pentaerythritol tetrastearate (PETS) are very particularly preferred. Particularly preferred is pentaerythritol tetrastearate (PETS).

Branching agents which can preferably be used are meltable modified bisphenol A epichlorohydrin resins, such as Araldite GY764CH or Araldite GT7071 from Huntsman, Everubel, Belgium.

The copolymers used according to the invention can be prepared by mixing, preferably by mixing the components in an extruder, by using a static mixer, or by other suitable devices capable of mixing two or more components together, And mixed with the ester matrix polymer. The melt may also be optionally strand extruded, cooled, and pelletized.

Master batch technology is also possible, in which case the copolymer is mixed as a concentrate or as a pure material with polyester pellets.

However, it is also possible to mix the individual components directly in a spinning or meltblowing plant, in which case the components can be introduced as a physical premix either through one supply port or separately via two or more supply ports. Another feasible possibility is to add them to the substream of the matrix polymer and then mix them into the main stream of the matrix polymer. Advantageously, the predetermined distribution here is established by the duration of the selection and mixing operation of the particular mixer, before the molten mixture is delivered to the individual spinning station and the spinning die through the product distribution line. Mixers with a shear rate of 16 to 128 sec < ^-1 > In fact, the product of 0.8 times the shear rate (sec ^-1 ) and the residence time (sec) should preferably be in the range of 250 to 2500, more preferably 350 to 1250. Values in excess of 2500 are generally avoided to limit the pressure drop in the piping line. Of course, it should be appreciated that the term thermoplastic material herein refers to the use of the term polymer.

Shear rate is defined herein as the apparent shear rate (sec ^-1 ) multiplied by the mixer factor, where the mixer factor is a characteristic parameter for the mixer type. For example, in the case of the Sulzer SMX type, this factor is about 7-8. The apparent shear rate < RTI ID = 0.0 >

, And the residence time is calculated according to the following formula:

.

In this formula,

F = polymer pump speed (g / min)

V ₂ = internal volume of the empty tube (cm 3)

R = Empty tube diameter (mm)

epsilon = Empty volume fraction (0.84 to 0.88 for the Sulzer SMX type)

delta = the nominal density of the polymer mixture in the melt (about 1.2 g / cm3).

The subsequent spinning of the polymer blend as well as the polymer blend is generally carried out according to the matrix polymer, preferably at a temperature of from 5 to 85 캜, and more preferably from 30 to 70 캜 (each of which exceeds the melting temperature of the matrix polymer) . The preferred temperature setting is 265 to 340 占 폚 for PET, and 225 to 300 占 폚 for nylon-6 and PBT.

Fibrous nonwoven webs made from the thermoplastic materials used in accordance with the present invention are produced, for example, in meltblown plants. Here, an extruder is used to heat the components and apply a high pressure to them. After any preliminary filtration with a suitable filter assembly, the melt is then pressurized through a spinneret at a precisely metered rate by a spinning pump. The polymer is still ejected from the die plate as microfibers (also called filaments in textile terms) in molten form. The air stream cools the filaments and stretches them to the melt state. The air stream transports the filaments onto a conveyor belt configured, for example, as a sieve, or onto a porous drum or onto an entry substrate, such as, for example, paper. Venting under the sieve belt causes the thread to stick. The random-laid sheet of such fibers is a fibrous nonwoven web requiring consolidation. Consolidation can be performed, for example, by two heating rolls (calenders) or by a vacuum stream. When performing a consolidation using a calendar, one of the two rolls typically has an engraved pattern of dots, short rectangles or rhombic dots. The filaments are fused at the contact points to form a nonwoven fabric. Although relatively lightweight nonwoven fabrics are obtainable only by this technique (thermal bonding), relatively heavy nonwoven fabrics are produced by the second entangled low melting point polymer by melting the hot-melt adhesive during the so-called fixing oven And the matrix fibers are typically bonded together at their intersections to ensure the desired toughness for the nonwoven. Consolidation is also possible by a hydroentangling method that jets water on unconfined webs at a water pressure of 400 bar or less.

The meltblowing process typically works with the following parameters:

Fiber diameter: 0.1 占 퐉 to 20 占 퐉, preferably 1 to 10 占 퐉

Web width: up to 5000 to 6000 mm

Air temperature: 230 to 400 占 폚, preferably 290 to 370 占 폚

Air speed: 0.5 to 0.8 times the speed of sound

Basis weight: 8 to 350 g / m 2, typically 20 to 200 g / m 2

Hole in spinneret Ø: 100 to 500 μm (1 to 6 holes / mm).

The high-toughness filaments are preferably produced by spinning at a take-off speed in the range of> 700 m / min, more preferably in the range of 750-1000 m / min, and by stretching at a corresponding speed, , A mixture of thermoplastic materials based on the present invention, preferably a polyamide / polyester mixture. This is accomplished using a self-emitting means known per se.

High-tear strength polyamide / polyester filaments are typically produced by a melt-spinning process in a large direct-melt spinning facility that distributes the melt to individual spinning lines through heating product lines and also to individual spinning systems in spinning lines . The radiation line is one or more columns of a series of radiation systems, wherein the radiation system is a minimum radiation unit having a radiation head containing one or more radiation die packs comprising a radiation die plate. In such a system, the melt is exposed to a high level of thermal stress with a residence time of up to 35 min. According to the present invention, the effectiveness of the copolymer used for surface tension reduction is not significantly affected by the high thermal stability of the copolymer, and therefore even with a small amount of surface tension, for example, < In many cases, even ≤ 1.5% of the additive is sufficient (despite high thermal stresses).

The die pack used in accordance with the present invention preferably has a die hole of 20 or more, more preferably 150 to 1500, and even more preferably 500 to 1000 die holes per meter of die diameter. A die hole diameter of 0.05 to 1 mm, more preferably 0.3 to 0.5 mm, is preferred.

The die discharge speed is preferably in the range of 1 to 20 m / min, more preferably 3 to 10 m / min. The hot blowing stream causes the extruded thread to be stretched to 50 to 800 times its length, preferably after its die evacuation, leading to a spinning speed of less than 10,000 m / min.

The present invention also relates to a method for reducing the surface tension of fibers or filaments based on a thermoplastic material, preferably fibers or filaments of a polyester base or fibers or filaments based on a polyamide, more preferably fibers of a polyester base or filaments, At least one alpha-olefin and at least one copolymer of at least one acrylic acid or methacrylic acid ester.

The present invention also relates to a process for the preparation of a thermoplastic material having a reduced surface tension obtainable by melt spinning a thermoplastic material-based fiber or filament to which at least one? -Olefin and at least one copolymer of at least one acrylic acid or methacrylic acid ester of an aliphatic alcohol have been added Fibers or filaments.

The present invention also relates to thermoplastic material-based fibers having reduced surface tension of the present invention, preferably one or more polymers selected from the group consisting of fibers each having a reduced surface < RTI ID = 0.0 > Preferably a fibrous nonwoven web, a nonwoven fabric, a woven fabric, a draw-loop knit, a non-crimped fabric or a foamed-loop fabric obtained from fibers or filaments of a polyester base with tension or polyamide- Knit, especially fibrous nonwoven webs or nonwoven fabrics.

It will be appreciated that for the sake of clarity, all definitions and parameters mentioned above in general terms or in preferred combinations are included in any desired combination in the context of the present invention.

In general, the surface tension of the fibers can be measured from their wettability by liquids having different polarities. A further possible way to measure the surface tension for the fiber product obtained according to the invention is to evaluate the absorption kinetics of the liquid medium (e.g. water or cyclohexane) absorbed by the fiber product using a suitable tensile system .

Example

The reduction in surface tension of the material obtained according to the invention is qualitatively verified in a fibrous nonwoven web obtained quantitatively and in a meltblown process on an injection-molded plate provided as a model system for accurate surface tension measurements.

Measurement of reduced surface tension in injection-molded plates :

To illustrate the surface tension reduction described in the present invention, the corresponding molding compound was first prepared. To this end, the individual components were extruded through a twin-screw extruder (ZSK 26 Mega Compounder from Coperion Werner & Pfleiderer, Stuttgart, Germany) at a temperature of 250-285 ° C, ), Strand extruded, cooled to the point where pelletization was possible, and pelletized. After drying (typically 2 to 6 h at 80 [deg.] C in a vacuum drying cabinet), the pellets were processed into specimens.

The specimens (rectangular plates with dimensions of 60 * 40 * 4 mm or 150 * 105 * 1.0 mm) for the tests recorded in Tables 1 and 2 were heated at a melting temperature of about 260 DEG C and at a molding temperature of about 80 DEG C, (Arburg) 320-210-500 type injection molding machine.

The surface tension of a rectangular plate obtained from the material produced according to the invention was measured in accordance with DIN ISO 8296 using a test ink in a simple and reproducible manner.

The surface tension according to DIN ISO 8296 is generally not similar to the values obtained according to ASTM D 2587-84. The surface tension value is recorded as nN / m (= dyn / cm).

The test method is based on an evaluation of the degree to which the polymer surface of the specimen is wetted by the ink having various surface tensions. The applicator attached to the bottle boundary is immersed in the test ink, brushed against the bottle rim, and used to apply the ink to the surface under test without delay. The stroke length shall be not less than 100 mm. The behavior of the stroke edge is evaluated over a length of 90%, so that the minimum non-uniformity is not considered. If the ink stroke is contracted in less than 2 seconds, the measurement must be repeated with ink of lower surface tension until the edge lasts for 2 seconds. If the ink stroke remains unchanged for more than 2 seconds, the measurement must be repeated with higher surface tension ink until it reaches 2 seconds. The value shown on the bottle then corresponds to the surface energy of the test plate. The test should be carried out under standard conditions of 23/50, i.e. 23 ° C +/- 2 ° C air temperature and 50% +/- 10% relative humidity.

This test was performed with a test ink from Softal Electronic GmbH of Hamburg, Germany (see Softal Report No. 108).

Measurement of surface tension in fibrous nonwoven web :

To reduce the surface tension of the thermoplastic fibers in the manner of the present invention, a fibrous nonwoven web having a basis weight of about 55 g / m < 2 > was prepared using a melt blown apparatus. The test was carried out at a melting temperature of about 275 캜 and a hot stream of about 360 캜. The ratio between melt throughput and air volume flow rate was chosen so that an average fiber thickness of about 1 mu m was obtained from a die diameter of 300 mu m. The fibrous nonwoven webs described in the examples and comparative examples of the present invention differ only in the specific polymer composition used and all other parameters and hence the nonwoven parameters such as basis weight, pore size, fiber orientation, Lt; RTI ID = 0.0 > and Comparative < / RTI >

For the qualitative evaluation of the surface tension, the water droplets were applied to the fibrous nonwoven web. Rapid wetting of the web in a liquid state represents a high level of surface tension (hydrophilic behavior), and droplet shape retention on the surface suggests a low level of surface tension. To achieve further distinction, an air stream was applied to the droplets. If the droplet leaves a trace in the form of a membrane, it can be qualitatively summarized that the surface tension is relatively high; If the droplet travels through the fibrous nonwoven web without leaving trace of visible water, it can be summarized to have a relatively low level of surface tension (see Table 3).

The following ingredients were used in the test:

Component A1: linear polybutylene terephthalate having an intrinsic viscosity (measured in 1: 1 phenol: 1,2-dichlorobenzene at 25 DEG C) of about 69 cm3 / g (Lanxess, Leverkusen, pokan (Pocan) from Deutschland GmbH) ^® B600)

Component A2: linear polybutylene terephthalate having an intrinsic viscosity (measured in 1: 1 phenol: 1,2-dichlorobenzene at 25 DEG C) of about 94 cm3 / g (from Lansess Deutschland GmbH, Leverkusen, Germany) pokan ^® B1300)

Component A3: a PET copolymer having an intrinsic viscosity of about 80 cm3 / g (PET Plus 80 from PET Kunststoffe Cycling GmbH, Beckerich-Overtiffenbach, Germany)

Component A4: Nylon 6 (Tan dure (Durethan) ^® B40F from Leverkusen, Germany Germany geem beha material is accessed)

Component B1: a copolymer of ethene and 2-ethylhexyl acrylate with 63 wt% of the ethene fraction and 550 MFI (France lot from ppyutto ahreuke materials do reel ^® 37 EH 550) [CAS No. 26984-27-0 ]

Component B2: 65 wt% fraction of ethene and copolymers of ethene and n- butyl acrylate having an MFI of 320 (from ahreuke French ppyutto materials do lot reel ^® 35 BA 320) [CAS No. 25750-84-9;

Higher values indicate a higher level of surface tension, thus exhibiting hydrophilic behavior, and the material becomes more and more hydrophobic as the surface tension value decreases. The example shows that the surface tension can only be reduced to the limit of 30 mN / m, where a value of 30 mN / m represents the saturation point. In the prior art (component B2 in Comparative Example 5), this limit is achieved with only 6 wt% of a copolymer of ethylene and butyl acrylate. If only 3 wt% is used, the surface tension can be reduced to only 34 mN / m. A comparison of the surface tension of component B1 and component B2 shows that even if the component B1, i.e. a copolymer of ethylene and 2-ethylhexyl acrylate, is used at a very low application level, for example 3 wt%, the surface tension of only 30 mN / m And provides very low surface tension.

The fact that the adherence of water droplets is greatly reduced as the concentration of component B1 is increased indicates that the wettability of the web with water is greatly reduced and thus it represents a reduction in the surface tension in the polyester fibers used in the web. With only 1 wt% of component B1, this is sufficient to achieve a critical hydrophobicity increase.

Claims (13)

one or more E / X copolymers of an alpha-olefin and an acrylic ester or methacrylate ester of an unsubstituted aliphatic alcohol having from 6 to 30 carbon atoms are added to the thermoplastic material and this is radiated by a melt-spinning process, Wherein the polyamide or polyester is used as a thermoplastic material and the alpha -olefin content in the E / X copolymer is 50 to 75 wt%. The method according to claim 1, wherein the polyester used is a polyalkylene terephthalate. The method according to claim 2, wherein the polyalkylene terephthalate is polyethylene terephthalate, polytrimethylene terephthalate or polybutylene terephthalate, or a mixture of these terephthalates. The method according to claim 1, wherein an aliphatic polyamide is used. 5. A process according to any one of claims 1 to 4, characterized in that a mixture based on 99.9 to 10 parts by weight of at least one thermoplastic material and 0.1 to 20 parts by weight of a copolymer is used for spinning. 5. Process according to any one of claims 1 to 4, characterized in that the? -Olefin has from 2 to 10 carbon atoms and can be unsubstituted or substituted with one or more aliphatic, cycloaliphatic or aromatic groups. The method according to claim 6, wherein the -olefin is selected from the group consisting of ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl- ≪ / RTI > delete The process according to any one of claims 1 to 4, wherein the additive material selected from a dye, a hydrophobing agent, a quencher, a stabilizer, an antistatic agent, a lubricant and a branching agent is added to the copolymer mixture in an amount of 0.001 to 5.0 wt% ≪ / RTI > delete 5. Process according to any one of claims 1 to 4, characterized in that an E / X copolymer of ethylene and an acrylate ester of an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms is added to the thermoplastic material. 12. The process according to claim 11, wherein E is ethylene and X is an acrylate ester having 6 to 20 carbon atoms. 12. The process according to claim 11, wherein E is ethylene and X is 2-ethylhexyl acrylate.