JP6290183B2 - Thermoplastic fibers with reduced surface tension - Google Patents

Description

  The present invention relates to a method for producing thermoplastic fibers with reduced surface tension, and also to products obtained by melt spinning processes from these thermoplastic fibers with reduced surface tension, the thermoplastic material used being at least It is mixed with a copolymer of one α-olefin and at least one aliphatic alcohol (preferably 2-ethylhexanol) with an acrylate or methacrylate ester.

  Products obtained from thermoplastic fibers from the group of polyamides or polyesters within the meaning of the present invention are fiber nonwoven webs, nonwovens, woven fabrics, yarns, yarns, ropes, felts, drawn loop knitted fabrics, non-crimp fabrics, or loops Knitted fabric. A fibrous nonwoven web or nonwoven is a preferred product within the meaning of the present invention. A fibrous nonwoven web consists of loosely assembled fibers that have not yet been bonded together. The strength of the fibrous nonwoven web is based solely on the inherent adhesion of the fibers. However, the inherent adhesion of the fiber can be affected by processing. In order to process and use a fibrous nonwoven web, it needs to be secured, and various schemes can be applied for this purpose. Only the bonded fibrous nonwoven web is desirably referred to as a nonwoven. This distinction is not made in spoken language.

  Nonwoven fabrics are fundamentally different from woven fabrics, stretched loop knitted fabrics, non-crimped woven fabrics, and looped knitted fabrics, which are characterized by laying individual fibers or yarns in a manner determined by the production process. . In contrast, a nonwoven fabric consists of fibers whose positioning can only be explained by statistical methods.

  The fibers in the nonwoven fabric are randomly arranged with respect to each other. Nonwoven fabrics are particularly classified based on fiber material (eg, polymer in the case of man-made fibers), bonding method, fiber type (staple fiber or continuous filament fiber), fiber delicacy, and fiber orientation. The fibers may be welded in a preferred direction in a defined manner, and the fibers may be in a fully stochastic orientation as in the case of a randomly laid nonwoven.

  Fibers are related to isotropic nonwovens if they do not have a preferred direction for their positioning (orientation). If the fibers are placed more frequently in one direction than the other, this is called anisotropy.

  Thus, a nonwoven fabric is a woven fabric that results in fabric formation by fusing the fibers with subsequent fixation rather than by weaving, looped knitting, stretched loop knitting, or predetermined laying. Compared to woven fabrics and looped knitted fabrics, non-woven fabrics continue to grow annually due to their wide range of applications and relatively low manufacturing costs.

  The advantage of non-woven fabrics is that the specific surface area is large, and the production process can vary the density, fiber dimensions, pore size or thickness over a wide range, resulting in a significant degree of isotropicity in one piece. Become. These advantageous properties are found in medicine for hygiene articles (in particular surgical cloth, sheets, wound dressings, gauze etc.), as any type of wiping cloth, decorative cloth (in particular tablecloth, Napkin) at home, as interlining, in the garment industry, technical applications (specifically, in the field of vehicles for engines and motors (eg oil filters) or as battery separators as insulation mats, covering mats or filter media), A very large number of uses are possible (Patent Document 1).

  Reduced surface tension can increase water repellency behavior, for example, and this water repellency can play an important role not only for applications in the garment industry but also as a filtering material in the vehicle field, Surface tension can play a critical role in many of these applications.

  The production of spunbond nonwovens consists of a direct combination between the spinning process and the web forming process. Not only melt spinning and dry spinning processes, but also wet spinning processes are suitable for forming webs based on continuous filament fibers. Various fiber-forming polymers are known as nonwoven starting materials. The nonwoven fabric based on continuous filament fibers according to the invention is produced as a so-called meltblown nonwoven fabric from thermoplastic polymers from the group of polyamides or polyesters, for example by melt spinning. The melt spinning process is described in, for example, (Patent Document 2) or (Patent Document 3) regarding polyester. The polyester nonwoven fabric is described in (Patent Document 4) or (Patent Document 5). The use of a polyester nonwoven fabric produced by a meltblowing process as a filter material forms the subject part of US Pat.

  Thermoplastic fibers formed from polyolefins (eg polypropylene fibers or polyethylene fibers) have a relatively low surface tension without the aid due to the inherent hydrophobicity of polyolefins, while higher surface tensions are comparable It relates to a more polar thermoplastic (preferably polyamide and polyester). Despite the low surface tension required, relatively high values of polymers (eg polyamides or polyesters etc.) must be used, for example due to insufficient thermal or chemical resistance on the polyolefin side As a result, there are many uses where this is a problem. Even if this is embodied and relatively more polar thermoplastics (eg, polyamides and polyesters), the general benefits (eg, heat resistance to oil and automotive fuel, mechanical robustness, and chemistry) There is often a desire to be denatured with the intent of achieving a lower surface tension while maintaining (resistance).

  The influence on the properties of the thermoplastic fiber to be spun by adding the thermoplastic material used to influence the properties of the thermoplastic fiber is related to the breaking strength using polyester as an example (Patent Document 7). It is described in. The thermoplastics added in that document are copolyesters containing in particular acrylic or methacrylic esters as monomer units. US Pat. No. 6,057,059 pursues a similar goal in using ethylene-alkyl acrylate copolymers in polyester films, tapes, and melt spun fibers to improve their mechanical properties (eg, tensile strength, etc.). ing. The literature explains that addition of more than 5% copolymer is preferred.

  (Patent Document 9) and (Patent Document 10) describe a woven fabric based on an oil- and water-repellent polyester by applying an aqueous emulsion of a fluorinated polymer to a ready-made woven fabric. (Patent Document 11) subsequently describes the hydrophobization of individual polyester fibers by providing polyoxyalkylene glycol and fluorine-based water and oil repellents (which have little reactivity with polyester) to the polyester fibers. Describe.

  US Pat. No. 6,057,089 specifically describes sanitary fabrics finished with fluorochemicals based on perfluoroalkyl groups having up to 4 carbon atoms as water repellent additives. Copolymers of such perfluoromaterials with acrylic esters or methacrylic esters are described as examples. U.S. Pat. No. 6,057,031 describes rubber-reinforced polyester monofilaments that have been specifically finished with a copolymer of ethylene and glycidyl methacrylate.

  (Patent Document 14) is obtained by a melt spinning process and is an E / X / Y copolymer (E represents ethylene, X represents in particular alkyl acrylate, Y represents in particular glycidyl acrylate, glycidyl methacrylate or glycidyl vinyl ether). An ethylene copolymer-modified polyamide product, which can be a finished fiber.

  US Pat. No. 6,057,859 finally discloses soft yarns based on polyamides or polyesters, which may be finished with a softener polymer of ethylene alkyl acrylate. Listed are methyl acrylate, ethyl acrylate, and butyl acrylate.

  All of these prior art solutions are achieved only in each case by a change in surface tension that results in oil and water repellency behavior, by subsequently applying an adjuvant to the woven fabric in an additional process step. Has the disadvantage of Subsequent application to the surface not only increases the complexity of the process, but also entails an increased risk of adjuvant release or washout, which not only weakens the desired surface effect, but is also problematic. (Eg, the filtrate is not purified when post-treated with filter media). Often it is necessary to rely on fluorine chemicals, but in addition to being very expensive, fluorine chemicals also need special considerations regarding the potential toxicity of fluorine chemicals, for example with regard to recovery by incineration It becomes.

International Publication No. 2009/103537 A1 Pamphlet European Patent Application No. 0880988A1 European Patent Application Publication No. 1473070A1 European Patent Application No. 2090682A1 European Patent Application No. 2092921A1 European Patent No. 0466381B1 German Patent Application Publication No. 199377729A1 International Publication No. 2005 / 040257A1 Pamphlet French Patent (FR-OS) No. 239746 Specification US Pat. No. 3,378,609 European Patent Application Publication No. 0196759 A1 International Publication No. 2009 / 152349A1 Pamphlet JP 2003-193331 A International Publication No. 2005 / 0878768A1 Pamphlet International Publication No. 2008 / 083820A1 Pamphlet

  Thus, the problem addressed by the present invention is such that a reduction in surface tension can be realized even without post-treatment of the product produced from the thermoplastic fiber concerned, and with very low material usage. First, it was about modifying the polyamide / polyester in advance. It is desirable that the modification further avoids fluorine chemicals, does not cause any change, and the fiber formation itself does not appear to be unacceptably impaired. Modifications to reduce surface tension should further be able to limit the additive added to its use concentration by its effectiveness, without any significant impact, if any, on the melt spinning process. The fibers obtained in this way can be further processed in various states, products with reduced surface tension, in particular fiber nonwoven webs, nonwoven fabrics, woven fabrics, stretched loop knitted fabrics, non-crimp fabrics or loops. A knitted fabric is desirable.

  The solution to the above problems and the subject of the present invention is a method for reducing the surface tension of thermoplastic-based fibers or filaments, which thermoplastic material comprises an α-olefin and an unsubstituted aliphatic alcohol (preferably At least one E / X copolymer with an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms, more preferably 2-ethylhexanol) and a methacrylic acid ester or acrylic acid ester, is added, It is subsequently spun and is preferably spun by a melt spinning process.

  By adding the E / X copolymer used according to the invention to the thermoplastic polyamide or polyester, the surface tension of the corresponding thermoplastic fibers and the products derived therefrom is very effectively reduced, and thus, for example, heat It has surprisingly been found that this results in a water-repellent treatment of plastic-based fibers (preferably polyamide / polyester fibers) and products derived therefrom. The copolymers used according to the present invention are so effective that a substantial reduction in surface tension is achieved even at very low concentrations, and thus has a decisive influence even if there is any influence on melt spinning. Does not exist.

  The method comprises 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, 0.1 to 20 parts by weight, Preferably defined as 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, and most preferably 1.0 to 2.0 wt%. Preference is given to using a mixture for spinning based on E / X copolymers.

  Preferred for use as thermoplastic-based fibers are fibers based on thermoplastic polymers from the group of polyamides or polyesters.

  Particularly preferred for use as thermoplastic-based fibers from the group of polyamides are fibers based on aliphatic polyamides.

  Particularly preferred for use as thermoplastic-based fibers from the group of polyesters are fibers based on polyalkylene terephthalates.

  The thermoplastic polyamides spun according to the present invention may be obtained in various ways and may be synthesized from very different building blocks. In particular application scenarios, the above-mentioned thermoplastic polyamides are used alone or in combination with processing aids, stabilizers, polymer alloys, in particular elastomers. Blends with some other polymers, preferably blends with polyethylene, polypropylene or ABS are also suitable, in which case one or more compatibilizers may optionally be used. The properties of the polyamide can be improved by mixing the elastomer, for example with respect to the breaking strength (for example the breaking strength of particularly low viscosity polyamides). Many possible combinations provide a number of products with a very wide range of properties.

  Polyamides have reactive groups for the use of different monomer building blocks, the use of various chain transfer agents to achieve the desired molecular weight, or subsequent intended post-treatment, depending on the desired end product. It can be obtained by many existing procedures involving the use of other monomers.

  The relevant industrial process for producing polyamides usually proceeds by polycondensation under melting. In this context, polycondensation also includes the hydrolysis polymerization of lactams.

  Suitable polyamides (PA) are partially crystalline polyamides which can be obtained from diamines and dicarboxylic acids and / or lactams having at least a 5-membered ring or the corresponding amino acids.

  Possible starting materials include aliphatic and / or aromatic dicarboxylic acids (eg, adipic acid, 2,2,4-trimethyladipic acid, 2,4,4-trimethyladipic acid, azelaic acid, sebacic acid, isophthalic acid, Terephthalic acid, etc.), aliphatic and / or aromatic diamines (eg, tetramethylenediamine, hexamethylenediamine, 1,9-nonanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylene) Diamines, isomeric diaminodicyclohexylmethane, diaminodicyclohexylpropane, bisaminomethylcyclohexane, phenylenediamine, xylylenediamine, and the like), aminocarboxylic acids (eg, aminocaproic acid, etc.), and the corresponding lactams. Included are copolyamides of the two or more monomers described.

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

  In addition to most molding compounds based on nylon-6, nylon-6,6 and other aliphatic or / and aromatic polyamides / copolyamides having 3-11 methylene groups in the polymer chain per polyamide group It is particularly appropriate to reach.

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

  Polyamides may also contain a mixture of conventional additives such as mold release agents, stabilizers and / or flow aids.

  It is particularly preferred that the thermoplastic polyester spun according to the invention is partly an aromatic polyester.

  Particularly preferred spun polyesters are selected from the group of polyalkylene terephthalate derivatives. Very particularly preferred spun polyesters are selected from the group of polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate, still more preferably polybutylene terephthalate and polyethylene terephthalate, most preferably polybutylene terephthalate, or a group of mixtures of these terephthalates. Selected from.

  A part of the aromatic polyester is a substance comprising an aliphatic part and further an aromatic part.

  The polyalkylene terephthalates for the purposes of the present invention are the reaction products of aromatic dicarboxylic acids or their reactive derivatives (especially dimethyl esters or anhydrides, and aliphatic, cycloaliphatic or araliphatic diols and their reactions). Etc.).

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

  Preferred polyalkylene terephthalates are at least 80 mol%, preferably 90 mol% terephthalic acid radicals based on dicarboxylic acids, and at least 80 mol%, preferably at least 90 mol% ethylene glycol and / or 1 based on diol components. , 3-propanediol and / or 1,4-butanediol radicals.

  Preferred polyalkylene terephthalates are in addition to terephthalic acid radicals, radicals of other aromatic dicarboxylic acids having 8 to 14 carbon atoms, or radicals of aliphatic dicarboxylic acids having 4 to 12 carbon atoms (specifically Phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4′-biphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid, cyclohexanedicarboxylic acid radical) 20 You may contain to mol%.

  Preferred polyalkylene terephthalates contain, in addition to the ethylene / 1,3-propanediol / 1,4-butanediol glycol radical, other aliphatic diols having 3 to 12 carbon atoms or 6 to 21 carbon atoms. Having an alicyclic diol (specifically, 1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4 -Cyclohexanedimethanol, 3-methyl-2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl- 1,6-pentanediol 2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol 2,5-hexanediol, 1,4-di (β-hydroxyethoxy) benzene, 2,2-bis (4-hydroxycyclohexyl) propane, 2,4-dihydroxy-1,1,3,3-tetramethyl- Cyclobutane, 2,2-bis (3-β-hydroxyethoxyphenyl) propane or 2,2-bis (4-hydroxypropoxyphenyl) propane radical) may be contained up to 20 mol% (German Patent Application Publication) No. A-2507674 (U.S. Pat. No. 4,086,212), German Patent Application Publication No. A-2507776, German Patent Application Publication No. A-2715932 (U.S. Pat. No. 4,176). 224 specification).

  Polyalkylene terephthalates can be trivalent or tetravalent alcohols or trivalent or tetravalent alcohols as described, for example, in German Offenlegungsschrift A-1900270 (U.S. Pat. No. A-369744). It may be branched by incorporating a relatively small amount of tetravalent carboxylic acid. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane, trimethylolpropane and pentaerythritol.

  It is not desirable to use more than 1 mol% of the branching agent based on the acid component.

  Polyalkylene terephthalate (specifically formed simply from terephthalic acid and reactive derivatives thereof (specifically, dialkyl esters thereof) and ethylene glycol and / or 1,3-propanediol and / or 1,4-butanediol In particular, polyethylene terephthalate and polybutylene terephthalate, and mixtures of these polyalkylene terephthalates) are particularly preferred.

  Suitable polyalkylene terephthalates further include copolyesters formed from at least two of the aforementioned acid components and / or at least two of the aforementioned alcohol components, wherein the copolyester is poly (ethylene glycol / 1,4-butanediol) terephthalate is particularly preferred.

The polyalkylene terephthalate is generally about 0.3 dl / g to 1.5 cm ³ / g, preferably 0.4 dl / g to 1.3 dl / g, more preferably 0.5 dl / g to 1.0 dl / g. (All measured with 1: 1 (w / w) phenol / o-dichlorobenzene at 25 ° C.).

  The thermoplastic polyesters preferably spun according to the present invention can also 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 polyester from recycled products before or after consumer use may also be used alone or mixed and used, in which case polyester recycled products from bottles (so-called PET copolyesters) ) Is preferred. An example of these is PET Plus 80® (PET Kunststoffcycling GmbH, from Beselich-Obertiefenbach, Germany).

15 mol% of other dicarboxylic acids and / or diols (specifically isophthalic acid, adipic acid, diethylene glycol, polyethylene glycol, 1,4-cyclohexanedimethanol, or any other C _2-4 alkylene glycol) Poly (C _2-4 alkylene) terephthalate containing up to is particularly preferably used as polyester in melt spinning. Polyethylene terephthalate having an intrinsic viscosity (IV) in the range of 0.5 to 1.4 dl / g, an I.V. of 0.7 to 1.6 dl / g. V. Polypropylene terephthalate having an I.I. of 0.5 to 1.8 dl / g. V. Polybutylene terephthalate having a viscosity of 1.5 to 1.0 dl / g is particularly preferred. Polybutylene terephthalate having an intrinsic viscosity (IV) in the range of 0.6 to 1.0 dl / g is preferred. 0.9 dl / g I.D. V. It is particularly preferred to have

  In order to reduce their surface tension, the thermoplastics spun according to the invention are composed of E (at least one α-olefin) and X (unsubstituted aliphatic alcohol methacrylic acid or acrylate ester). Contains E / X copolymer. Alpha olefins suitable for use as component E of the copolymer preferably have from 2 to 10 carbon atoms and, even if unsubstituted, one or more aliphatic, alicyclic or aromatic groups May be substituted. Suitable α-olefins are selected from the group comprising ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl-1-pentene. Particularly preferred α-olefins are ethene and propene, with ethene being very particularly preferred. Also suitable are mixtures of the α-olefins mentioned.

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

  The E / X copolymer is further defined by a second component in addition to the α-olefin. The alkyl or arylalkyl group of an acrylic or methacrylic acid alkyl ester or arylalkyl ester is formed from 5 to 30 carbon atoms and includes epoxides, oxetanes, anhydrides, imides, aziridines, furans, acids, amines An alkyl ester or arylalkyl ester of acrylic acid or methacrylic acid containing any concentration of reactive functional groups (if any, if any) selected from the group consisting of for use as a second component Is appropriate. Alkyl or arylalkyl groups may be linear or branched, include alicyclic groups or aromatic groups, and are substituted by one or more ether or thioether functional groups. Methacrylic or acrylic esters synthesized from alcohol components based on oligoethylene glycol or oligopropylene glycol having only hydroxyl groups and up to 30 carbon atoms as suitable methacrylic or acrylic esters in this connection Also mentioned.

The alkyl group or arylalkyl group of methacrylic acid ester or acrylic acid ester is 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl, 3-heptyl, 1-octyl, 1- (2-ethyl) hexyl, 1 -Preferably selected from the group comprising nonyl, 1-decyl, 1-dodecyl, 1-lauryl or 1-octadecyl. Particularly preferred are unsubstituted alkyl groups or arylalkyl groups of 6 to 20 carbon atoms, more preferably 8 to 20 carbon atoms. Branched alkyl groups are also particularly preferred, and the branched alkyl group has a lower glass transition temperature _TG than a linear alkyl group having the same number of carbon atoms.

  Copolymers where α-olefins are copolymerized with 2-ethylhexyl acrylate are particularly preferred for the purposes of the present invention.

  Likewise suitable are mixtures of the acrylic or methacrylic esters mentioned.

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

  Particularly suitable copolymers are selected from the group of materials available from Arkema under the trademark Lotryl® EH, some of which are also used as hot melt adhesives.

  The present invention is particularly preferred in accordance with a process for reducing the surface tension of polyester-based fibers or polyamide-based fibers, and acrylic esters of unsubstituted aliphatic alcohols having 6 to 30 carbon atoms. An E / X copolymer, preferably an E / X copolymer of E ethylene having 6 to 20 carbon atoms and an X acrylate ester, more preferably an E / X copolymer of E ethylene and X2-ethylhexyl acrylate, It is characterized in that it is added to the plastic material and the mixture is subsequently spun by a melt spinning process.

  The present invention is particularly preferred in accordance with a process for reducing the surface tension of polyester-based fibers and is an E / X of ethylene and an acrylate ester of an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms. A copolymer, preferably an E / X copolymer of E ethylene with 6-20 carbon atoms and an X acrylate ester, more preferably an E / X copolymer of E ethylene and X2-ethylhexyl acrylate, is added to the plastic material. , Characterized in that the mixture is subsequently spun by a melt spinning process.

The present invention is particularly preferred in accordance with a process for reducing the surface tension of polyamide-based fibers and is an E / X of ethylene and an acrylate ester of an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms. A copolymer, preferably an E / X copolymer of E ethylene with 6-20 carbon atoms and an X acrylate ester, more preferably an E / X copolymer of E ethylene and X2-ethylhexyl acrylate, is added to the plastic material. , Characterized in that the mixture is subsequently spun by a melt spinning process. The amount of copolymer added to the polyamide / polyester mixture processed by spinning is, for example, specified above and will be found to be sufficient in most cases for 6 wt% or less. The copolymer concentration is selected from the range of 0.75 to 6.0 wt% according to the desired take-up speed (> 700-1500 m / min) so that the birefringence of the fiber is less than 3.5 × 10 ⁻³ Preferably it is done. This type of fiber birefringence gives a draw ratio of 5: 1 and ensures the desired high yarn tensile strength at winding speeds that clearly exceed 3800 m / min irrespective of the spinning take-up speed up to 1500 m / min. .

  Conventionally added substances, preferably dyes, further hydrophobizing agents, matting agents, stabilizers, antistatic agents, lubricants, branching agents are added to the thermoplastic copolymer mixture according to the invention in an amount of 0.001 to 5.0 wt%. May be added safely in amounts.

  Preferred dyes that may be used are disperse dyes, in particular disperse dyes based on azo dyes or disperse dyes based on crushed carbon black.

  A preferred matting agent that may be used is a microcrystalline anatase having an average particle size [d50] of 0.25 to 0.35 μm and may have an organic or inorganic surface treatment.

  Preferred stabilizers that may be used include, for example, aromatic polycarbodiimides such as Stabaxol P (Mannheim, from Rheinchemie, Germany), and thermal stabilizers based on organic phosphite derivatives.

  Preferred antistatic agents that may be used are especially crushed conductive grade carbon black or carbon nanotubes.

  Preferred lubricants that may be used are in particular long chain fatty acids (preferably stearic acid or behenic acid), their salts (preferably calcium stearate or zinc stearate), and also their ester derivatives as well as low molecular weights Polyethylene wax and / or polypropylene wax. A montan wax within the meaning of the present invention is a mixture of straight-chain saturated carboxylic acids having a chain length of 28 to 32 carbon atoms. Suitable lubricants and / or mold release agents are compounds from the group of low molecular weight polyethylene waxes and saturated or unsaturated aliphatic carboxylic acids having 8 to 40 carbon atoms and 2 to 40 carbon atoms. Compounds from the group of amides or esters with aliphatic saturated amines or alcohols having Ethylene bisstearylamide and pentaerythritol tetrastearate (PETS) are very particularly preferred for the purposes of the present invention. In particular, pentaerythritol tetrastearate (PETS) is very particularly preferred.

  A preferred branching agent that may be used is a melt-modified bisphenol A epichlorohydrin resin (eg Araldite GY764CH or Araldite GT7071 from Huntsman, Belgium).

  The copolymer used according to the invention is preferably via a mixing element in an extruder by using a static mixer, or via other suitable equipment capable of mixing two or more components each or one another. And mixed with the polyamide / polyester matrix polymer by mixing. The melt may optionally be extruded through strands, cooled and granulated.

  Masterbatch techniques are also possible, in which the copolymer is mixed with the polyester pellets as a concentrate or as a pure substance.

However, the individual components may also be mixed directly in a spinning or meltblowing facility, in which case the components may be introduced as a physical premix from one supply port, and so on Otherwise, they may be introduced separately from two or more supply ports. Another possibility is that the individual components are added downstream of the matrix polymer and then mixed into the main stream of the matrix polymer. Advantageously, the determined distribution is established there by the detailed selection of the mixer and the continuation of the mixing operation before the molten mixture is advanced through the product distribution line to the individual spinning position and spinning mold. Is done. A mixer having a shear rate of 16-128 sec ^-1 will prove advantageous. In practice, the product formed by multiplying the shear rate (sec ⁻¹ ) by the residence time (seconds) to the power of 0.8 should preferably be in the range of 250-2500, more preferably 350-1250. . In order to keep the pressure drop in the pipeline within limits, values above 2500 are generally avoided. To avoid uncertainties, it may also be specified that a thermoplastic is represented herein using the term “polymer”.

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滞留時間は、

により算出され、
式中、
Ｆ＝ポリマーのポンプ速度（ｇ／分）
Ｖ_２＝空管の内容積（ｃｍ^３）
Ｒ＝空管の直径（ｍｍ）
ε＝空の容積分率（Ｓｕｌｚｅｒ ＳＭＸ型に対して０．８４〜０．８８）
δ＝溶融下におけるポリマー混合物の基準密度（約１．２ｇ／ｃｍ^３）である。 The shear rate is defined herein as the product of the surface shear rate (sec ⁻¹ ) and the mixer factor. The mixer factor is a characteristic parameter of the mixer type. For a Sulzer SMX type, for example, this factor is about 7-8. The shear rate γ of the surface is

Calculated by
Residence time is

Calculated by
Where
F = Polymer pump speed (g / min)
V ₂ = inner volume of the empty tube (cm ³ )
R = Diameter of empty tube (mm)
ε = empty volume fraction (0.84-0.88 for Sulzer SMX type)
δ = standard density of polymer mixture under melting (about 1.2 g / cm ³ ).

  Not only the mixing of the polymers, but also the subsequent spinning of the polymer mixture generally depends on the matrix polymer, preferably in the range of 5 to 85 ° C., more preferably in the range of 30 to 70 ° C. Carried out at temperatures above. Suitable temperature settings are 265-340 ° C for PET and 225-300 ° C for nylon-6 and PBT.

  Fiber nonwoven webs produced from thermoplastic materials used in accordance with the present invention are produced, for example, in meltblowing plant equipment. In the factory equipment, the ingredients are heated using an extruder to a high pressure state. After optional prefiltration with a suitable filter assembly, the melt is pressurized with a spinning pump at a precise metering rate through a spinneret. The polymer exits the mold plate as fine fibers (called filaments in textile terminology) while still in molten form. An air stream cools the filament and stretches the filament while it is in a molten state. The air stream carries the filaments, for example, on a conveyor belt constructed as a sieve, or on a porous drum, or on a receiving object (eg, paper). The yarn is fixed by suction under the sieve belt. This randomly laid fiber sheet is a fibrous nonwoven web that needs to be secured. For example, it may be fixed by two heating rolls (calendar) or by a steam flow. When fixed using a calendar, usually one of the two rolls has a digging pattern consisting of dots, short rectangular or rhombus dots. The filaments fuse at the point of contact, thus forming a nonwoven fabric. Relatively lightweight nonwovens can only be obtained with this technique (thermal bonding), while relatively heavy nonwovens have been incorporated second by dissolving the hot melt adhesive in the course of passing through a so-called fixing furnace. Produced with a low melting polymer, the matrix fibers are usually bonded together at their intersections, thereby ensuring the desired tensile strength for the nonwoven. Fixing is further made possible by hydroentanglement, in which the squirt water hits a web that has not yet been fixed at a water pressure of up to 400 bar.

The meltblowing process is usually performed with the following parameters:
Fiber diameter 0.1 μm to 20 μm, preferably 1 to 10 μm
Web width Up to 5000-6000mm Air temperature 230-400 ° C, preferably 290 ° -370 ° C
Airspeed 0.5 to 0.8 times the speed of sound Basis weight 8 to 350 g / m ² , usually 20 to 200 g / m ²
Holes in the spinneret φ100 to 500 μm (having 1 to 6 holes / mm)

  Filaments with high tensile strength are spun at a take-up speed of more than 700 m / min (more preferably in the range of 750 to 1000 m / min), drawn, thermoset and wound up at a corresponding speed. Is preferably produced from a thermoplastic base mixture (preferably a polyamide / polyester mixture) used according to This is achieved using spinning means well known per se.

  High tensile strength polyamide / polyester filaments are usually produced by a melt spinning process in large direct melt spinning equipment, where the melt is fed into individual spinning lines via heated production lines and within the spinning lines. Distributed in individual spinning systems. A spinning line is a series of one or more spinning systems, while a spinning system is the smallest spinning unit having a spin head, which is a pack of at least one spinning mold (spinning mold). (Including template). Such system melts are exposed to high levels of thermal stress in residence times up to 35 minutes. The effect of the copolymer used to reduce the surface tension according to the present invention is not significantly affected as a result of the high thermal stability of the copolymer and is therefore small (eg, 2.0% or less, in many cases 1. Even up to 5%) additives are sufficient, depending on the desired reduction in surface tension, despite high thermal stresses.

  Mold packs used in accordance with the present invention preferably have at least 20, more preferably 150-1500, and still more preferably 500-1000 mold holes per meter of mold width. The diameter of the mold hole is preferably 0.05 to 1 mm, particularly preferably 0.3 to 0.5 mm.

  The exit speed of the mold is preferably in the range of 1 to 20 m / min, more preferably 3 to 10 m / min. By blowing hot air currents, the extruded yarns are stretched preferably 50 to 800 times their length at the outlet of the column mold, resulting in spinning speeds up to 10,000 m / min.

  The present invention further provides for reducing the surface tension of thermoplastic-based fibers or filaments, preferably polyester-based fibers or filaments, or polyamide-based fibers or filaments, more preferably polyester-based fibers or filaments. It relates to the use of at least one copolymer of at least one α-olefin and at least one acrylic ester or methacrylic ester.

  The present invention melt-spins thermoplastic-based fibers or filaments to which at least one copolymer of at least one α-olefin and at least one acrylic ester or methacrylic ester of an aliphatic alcohol is added. It further relates to fibers or filaments with reduced surface tension, which can be obtained.

  The present invention also provides a product (preferably a fibrous nonwoven web) that can be obtained from the reduced surface tension, thermoplastic based fibers of the present invention, preferably polyester based fibers or filaments, or polyamide based fibers or filaments. , Nonwoven fabrics, woven fabrics, stretched loop knitted fabrics, non-crimped woven fabrics or looped knitted fabrics, in particular fiber nonwoven webs or nonwoven fabrics, each fiber of reduced surface tension comprising at least one α-olefin and at least 1 At least one copolymer with a certain acrylic ester or methacrylic ester is added.

  It is explicitly stated that all definitions and parameters listed above in general terms or suitable combinations are included in any desired combination in the context of the present invention.

  In general, the surface tension of a fiber can be determined from the wettability of the fiber using liquids of different polarities. A further possible method for determining the surface tension of a textile product obtained according to the invention is to test the absorption rate of a liquid medium (eg water or cyclohexane) absorbed by the textile product using a suitable tensiometer. It involves doing.

  Of the material obtained according to the invention quantitatively on an injection-molded plate serving as a model system for accurate measurement of surface tension and qualitatively on a fibrous nonwoven web obtained by a melt-blowing process. Demonstrate reduced surface tension.

Demonstration of Reduced Surface Tension on Injection Molded Plate To illustrate the reduction in surface tension described in the present invention, the corresponding molding compound was first prepared. For this purpose, the individual components are mixed at a temperature of 250-285 ° C. in a twin screw extruder (ZSK 26 Mega Compounder from Coperion Werner & Pfleiderer) (Stuttgart, Germany), strand extruded and brought to a granulating temperature. Cooled and granulated. After drying (typically 2 to 6 hours at 80 ° C. in a vacuum oven), the pellets were processed into test pieces.

  Test specimens (60 × 40 × 4 mm or 150 × 105 × 1.0 mm rectangular plates) reported in Tables 1 and 2 were placed on an Arburg 320-210-500 injection molding machine at about 260 ° C. It was made at a melting temperature of about 80 ° C.

  Using a test ink, the surface tension of a rectangular plate obtained from a material made according to the invention was measured according to DIN ISO 8296 in a simple and reproducible manner.

  The surface tension for DIN ISO 8296 is generally not comparable to the value obtained according to ASTM D 2587-84. The surface tension value is reported in nN / m (= dyn / cm).

  The test method is based on evaluating the degree to which inks with various surface tensions wet the polymer surface of the test strip. An applicator attached to the bottle closure is dipped into the test ink and rubbed against the edge of the bottle and used to apply the ink to the surface under test without delay. The length of the drawn line is preferably at least 100 mm. The stroke end behavior is evaluated for 90% length and does not take into account the smallest inhomogeneities. If the ink stroke shrinks in less than 2 seconds, the measurement needs to be repeated with an ink having a lower surface tension until the edge lasts 2 seconds. If the ink stroke remains unchanged for more than 2 seconds, the measurement needs to be repeated with an ink with a higher surface tension until 2 seconds is achieved. The value shown on the bottle at that time corresponds to the surface energy of the test plate. The test needs to be carried out under 23/50 standard conditions (ie temperature 23 ° C. + / − 2 ° C. and relative humidity 50% + / − 10%).

  The test was carried out using test inks from Soft Electronic GmbH (see Soft Report No. 108), Hamburg, Germany.

Determination of the surface tension of a fiber nonwoven web In order to reduce the surface tension of thermoplastic fibers in the method of the present invention, a fiber nonwoven web having a basis weight of about 55 g / m ² is produced using a melt-blowing device. did. The test was performed using a melt temperature at about 275 ° C and a hot air stream at about 360 ° C. The ratio of melt extrusion rate to air volume flow rate was chosen to obtain an average fiber thickness of about 1 μm from a 300 μm mold diameter. The fibrous nonwoven web described in the present invention and the comparative fibrous nonwoven web differ only in the specific polymer composition used, and all other parameters, i.e., the nonwoven web parameters (e.g., basis weight, pore size). , Fiber orientation, fiber thickness, etc.) maintain the same parameters in the present invention and comparative examples.

  In order to qualitatively assess surface tension, water droplets were applied to the fibrous nonwoven web. The rapid wetting of the web with water droplets shows a high level of surface tension (hydrophilic behavior), while the shape of the droplets remaining on the surface suggests a low level of surface tension. To achieve further identification, an air stream was applied to the droplets. When the droplets leave a trace in the form of a water film, it is qualitatively summarized that the surface tension is relatively high, and the droplets leave the fibrous nonwoven web without leaving a visible trace of water. When moving across, a relatively low level of surface tension can be summarized (see Table 3).

The following were used in the test:
Component A1: Linear polybutylene terephthalate (Lances Deutschland GmbH, Leverkusen, Germany) with an intrinsic viscosity of about 69 cm ³ / g (measured at 25 ° C. in 1: 1 phenol: 1,2-dichlorobenzene) (Pocan® B600 from)
Component A2: Linear polybutylene terephthalate (Pocan from Lanxess Deutschland GmbH, Leverkusen, Germany) having an intrinsic viscosity of about 94 cm ³ / g (measured at 25 ° C. in 1: 1 phenol: 1,2-dichlorobenzene) (Registered trademark) B1300)
Component A3: PET copolymer having an intrinsic viscosity of about 80 cm ³ / g (PET plus 80 from PET Kunststoffcycling GmbH, Besselig Obertyfenbach, Germany)
Component A4: Nylon-6 (Durethan® B40F from Lanxess Deutschland GmbH, Leverkusen, Germany)
Component B1: Copolymer of ethene and 2-ethylhexyl acrylate with 63 wt% ethene moiety and 550 MFI (Arkema, Puteauux, Lotryl® 37 EH 550 from France) [CAS number 26984-27- 0]
Component B2: Lotryl® 35 BA 320: Copolymer of ethene and n-butyl acrylate with 65% ethene moiety and MFI of 320 (Lotryl® 35 BA 320 from Arkema, Puteaux, France) [ CAS number 25750-84-9]

  A high value indicates a high level of surface tension, ie suggests hydrophilic behavior, but the material becomes increasingly hydrophobic as the surface tension value decreases. This 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 point of saturation. In the prior art (component B2 in Comparative Example 5), this limit is only realized with a copolymer of ethylene and butyl acrylate (6 wt%). When only 3 wt% is used, the surface tension can be reduced to 34 mN / m. From a comparison of the surface tensions of component B1 and component B2, it can be seen that even though component B1, a copolymer of ethylene and 2-ethylhexyl acrylate, is used at a very low application concentration, eg 3 wt%, a very low surface of just 30 mN / m Brings tension.

  The fact that the adhesion of water drops decreases dramatically with increasing concentration of component B1 suggests that the wettability of the web with water is significantly reduced, and thus the reduction in surface tension in the polyester fibers used for the web. To suggest. Only 1 wt% of component B1 is sufficient to achieve a critical increase in hydrophobicity.

Claims (10)

  In a method for reducing the surface tension of a thermoplastic-based fiber or filament, the thermoplastic material is an acrylate or methacrylate ester of an unsubstituted aliphatic alcohol having an α-olefin and 6 to 30 carbon atoms. At least one E / X copolymer is added and spun by a melt spinning process, and the thermoplastic material used is a polyamide or a polyester, and the α-olefin content of the copolymer is 75 wt% or less A method characterized by that.   The polyester used is a polyalkylene terephthalate, preferably polyethylene terephthalate, polytrimethylene terephthalate or polybutylene terephthalate, more preferably polybutylene terephthalate and polyethylene terephthalate, particularly most preferably polybutylene terephthalate, or a mixture of these terephthalates. The method of claim 1, wherein:   2. Process according to claim 1, characterized in that the polyamide used is an aliphatic polyamide.   A mixture based on 99.9-10 parts by weight of at least one thermoplastic and 0.1-20 parts by weight of a copolymer is used for spinning. The method according to any one of the above.   The α-olefin has 2 to 10 carbon atoms and may be unsubstituted or substituted with one or more aliphatic groups, alicyclic groups or aromatic groups. The method of any one of 1-4.   α-olefin is ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl-1-pentene, suitable α-olefins are ethene and propene, 6. Process according to claim 5, characterized in that it is selected from the group comprising particularly preferred and mixtures of these [alpha] -olefins.   The process according to claim 5 or 6, characterized in that the alpha-olefin content of the copolymer is 50-75 wt%, preferably 55-75 wt%.   A conventionally added substance selected from dyes, hydrophobizing agents, matting agents, stabilizers, antistatic agents, lubricants, branching agents is used in the thermoplastic copolymer mixture in an amount of 0.001 to 5.0 wt%. The method according to claim 1, wherein the method is added to the method.   E / X copolymer of the thermoplastic material with ethylene and an acrylate ester of an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms, preferably E ethylene and acrylic acid having 6 to 20 carbon atoms 9. Process according to any one of claims 1 to 8, characterized in that an E / X copolymer with an ester, more preferably an E / X copolymer of E ethylene and X2-ethylhexyl acrylate, is added. At least one of an α-olefin and an acrylic or methacrylic ester of an unsubstituted aliphatic alcohol having 6 to 30 carbon atoms for reducing the surface tension of a thermoplastic-based fiber or filament Use of E / X copolymer , wherein the thermoplastic material is polyamide or polyester, and the α-olefin content of the copolymer is 75 wt% or less .