Patent Application
20200080236
The present invention concerns melt-spun fibers from selected polyketone-containing compositions, their manufacture and various applications of these fibres.
For technical applications, synthetic threads made of melt-spinnable polymers are preferred. For cost reasons, long-known standard polymers are used, for example, polyolefins, such as polyethylene (PE), polypropylene (PP), or polyamides, such as polyamide 6 (PA 6), polyamide 6.6 (PA 6.6) or polyesters, such as polyethylene terephthalate (PET), provided that threads from these polymers can meet the desired requirements.
In technical applications, a low sliding friction of textile fabrics is often desired. Additional properties are also often desired, such as a certain coloration, stability against degradation by thermal stress or by exposure to radiation, special mechanical properties, such as increased impact resistance, low elongation at break, increased abrasion resistance, dimensional stability, bending strength or bending recovery.
Fibers made of aliphatic polyketones and from combinations of aliphatic polyketones with selected other polymers are well known.
EP 0 310 171 A2 describes melt-spun fibers from these materials, for example from ethylene/propylene/CO-terpolymers. These fibers have high tensile strength and E-moduli and are proposed for use as a tire cord or for the production of spunbonded fabrics. The latter are suitable for the production of roof liners or as geotextiles.
DE 197 57 607 A1 discloses polyamide/polyketone blends that can be processed into threads or fibers. Multi-component fibers are not disclosed.
DE 198 53 707 A1 discloses stabilized aliphatic polyketones, which can be present as fibers, amongs others.
From WO 94/20562 A1 and WO 99/41437 A1 aliphatic polyketones are known, which amongs others may be available as fibers, and which can be stabilized with antioxidants.
CN 106 521 704 A describes mixtures of aliphatic polyketones and polyoxymethylene, which amongst others can be present as fibers and which can be stabilized with antioxidants. Multi-component fibers are not disclosed.
WO 2016/190594 A2 and WO 2016/190596 A2 disclose wet-spun fibers from ethylene/propylene/CO-terpolymers, which have excellent strength and strain values and which are also characterized by high water resistance and heat resistance and by good thermal conductivity. Different fields of use are proposed as applications for these fibers, such as the manufacture of ropes, hoses, nets, spunbonded fabrics, airbags or protective clothings, as well as the use as geotextiles, as reinforcing fibers in composite materials, as belts, safety nets, conveyor belts, fishing cords or tennis strings.
In wet spinning, the dissolved polymer is spun into threads through a spinning capillary. The solvent is retrieved as completely as possible and is returned into the manufacturing process. However, it cannot be avoided that small proportions of the solvent used are left in the finished fiber. It is desirable to provide a solvent-free fiber. This avoids any potential safety risk caused by the presence of solvent residues in the fiber. In addition, melting spinning can lead to higher levels of crystallization, which can have a beneficial effect on the mechanical properties of the fiber.
On the other hand, processing by melt-spinning often has to take place at significantly higher temperatures than wet spinning. This can lead to accelerated degradation or crosslinking reactions of the polymer, which in turn can have a detrimental effect on the properties of the produced fiber or which can lead to crosslinking reactions of the polymer, which can limit their processability in the extrusion process.
Surprisingly, it was found that by a combination of adjusted process parameters (temperature, shear, throughput, spinning delay, degree of stretching, fixation, dwell time), the degree of crosslinking of the polymer can be controlled and thereby the thermo-mechanical properties of the fibers can be specifically improved, such as their heat resistance, hydrolysis resistance, chemical resistance, abrasion resistance, bending resistance, bending recovery, module, creep behavior and cranking tendency.
Dimensional stability describes the tendency of a fiber to show a change in length under tension and at a certain temperature. This results from a combination of the tensile module and the creep properties of the fiber, such as of a monofilament.
It has been found that the dimensional stability of the fibers based on aliphatic polyketones can be achieved by appropriate additivation. Selected polymeric additives can be used, which are dispersed in the matrix of aliphatic polyketone. For example, fibrils can be formed from the dispersed phase and/or the surface of the fiber is modified by the dispersed phase.
In combinations of aliphatic polyketones and selected other polymers, the individual polymer components complement each other in a synergistic way. For example, the fibers are imparted excellent mechanical properties by the other polymers (high module, low creep, low cranking tendency) and by the aliphatic polyketone low sliding friction as well as increased abrasion resistance are imparted.
It was also found that textile fabrics, such as fabrics or bundles comprising yarns made of aliphatic polyketones or multi-component yarns with aliphatic polyketones as a sheath and with the other polymer as the core show a very small sliding friction and a very high abrasion resistance in dry state as well as in wet conditions.
It was also found that fibers made from selected conventional polymers can be combined with aliphatic polyketones to form fibers characterized by low sliding friction and high bending resistance.
Multi-component fibers with selected properties can be obtained, such as fibers with sheath-core-structures, wherein the sheath is made of aliphatic polyketone and the core is made of polyester, such as of polyethylene terephthalate or of polycarbonate or is made of aliphatic polyketone with a higher melting point than the aliphatic polyketone of the sheath. By varying the melting points of the sheath polymers, for example, adhesive properties can be precisely set.
As a result of the intrinsic chemical resistance and the good barrier properties of aliphatic polyketones, sheath-core-fibers with high chemical resistance can be produced.
Thus, hot melt variants with low melting point and therefore possible thermal binding with a substrate or with other monofilaments in a textile construct can be produced, e.g. in fabrics or knittings. In addition, fibers are produced with low friction coefficients and very good abrasion resistance.
One objective of the present invention is to provide such fibers with the above mentioned property profile.
Another objective of the present invention is to provide a spinning process for the production of such fibers.
The present invention concerns in a first embodiment melt-spun fibers containing thermoplastic aliphatic polyketone as a first polymer and polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer and/or aliphatic polyketone as a second polymer, wherein in case that aliphatic polyketone is present as the second polymer its melting point is at least 5° C., preferably at least 10° C., especially preferred at least 20° C. higher than the melting point of the aliphatic polyketone of the first polymer.
In a second embodiment, the present invention concerns melt-spun fibers containing thermoplastic aliphatic polyketone as a first polymer and polyolefin, polyester, polyamide, polyoxymethylene, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylen etherketone, liquid crystalline polymer and/or aliphatic polyketone as a second polymer, with the polymers being in the form of two or more fiber components that are spatially separated from one another but are interrelated among each other and wherein in case that aliphatic polyketone is present as the second polymer its melting point is at least 5° C., preferably at least 10° C., especially preferred at least 20° C. higher than the melting point of the aliphatic polyketone of the first polymer.
In a third embodiment, the present invention concerns melt-spun fibers containing thermoplastic aliphatic polyketone as a matrix polymer and therein dispersed particles of polysiloxanes or of poly(meth)acrylates.
The aliphatic polyketones used according to the invention are homo- or copolymers with recurring structural units of the formula R1—CO—, with R1 meaning a divalent aliphatic residue, preferably a divalent aliphatic residue with two to six carbon atoms.
Preferred residues R1 have the formula CnH2n—, in which n is 2, 3 or 4, in particular 2 or 3.
Copolymers with different residues R1 in the polymer chain are preferred, for example with residues C2H4— and with residues —C3H7—.
A thermoplastic ethylene/propylene/CO-terpolymer is particularly preferred as an aliphatic polyketone.
Aliphatic polyketones are semi-crystalline polymers that have a melting point determined by differential thermoanalysis (DSC). For the purposes of the present description, the DSC analysis is carried out according to ASTM D3418. The heating speed is 10 K/min.
Also particularly preferred aliphatic polyketones are used with a melting range from 199 to 220° C. and with a MFI value at 240° C. and 2.16 daN from 6 to 60 g/10 min (according to ASTM-D 1238).
The aliphatic polyketones used according to the invention are known polymers, which also have already been used for fiber production.
In a preferred embodiment, the melt-spun fibres according to the invention contain an antioxidant.
Sterically hindered phenols and/or HALS (hindered amine light stabilizers) and/or phosphites can be used as antioxidants, which may be combined with co-stabilizers.
Preferably used antioxidants based on sterically hindered phenols are sterically hindered alkylated monopenols, e.g. 2.6-di-tert-butyl-4-methylphenol or 2.6-di-tert.-butyl-4-methoxyphenol; sterically hindered alkylthiomethylphenols, e.g. 2.4-di-octylthiomethyl-6-tert.-butylphenol, sterically hindered hydroxylated thiodiphenylethers, e.g. 2,2′-thio-bis(6-tert-butyl-4-methylphenol), 4,4′-thio-bis-(6-tert-butyl-3-methyl-phenol), 4,4′-thio-bis-(6-tert-butyl-2-methylphenol), 4,4′-thio-bis-(3,6-di-sec.-amylphenol), 4,4′-bis-(2,6-di-methyl-4-hydroxyphenyl)-disulfide; sterically hindered alkylidene-bisphenols, e.g. 2,2′-methylene-bis-(6-tert-butyl-4-methylphenol; sterically hindered benzylphenols, e.g. 3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzylether; sterically hindered hydroxybenzylated malonates, e g. dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hydroxy-benzyl)-malonate, sterically hindered hydroxybenzyl-aromatics, e.g. 1,3,5-tris-(3,5-di-tert-butyl)-4-hydroxy-benzyl)-2,4,6-trimethylbenzene, 1,4-bis-(3,5-di-tert-butyl-4-hydroxy-benzyl)-2,3,5,6-tetramethylbenzene, 2,4,6-tris-(3,5-di-tert-butyl-4-hydroxy-benzyl)-phenol; sterically hindered phenolic triazine compounds, e. g. 2,4-bis-octylmercapto-6(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, sterically hindered phenolic benzylphosphonates, e.g. dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate; N-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamin-acid alkyl esters; esters of β-(3.5-di-tert-butyl-4-hydroxyphenyl)-propionic acid with mono- or multivalent alcohols; esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propic acid with mono- or multivalent alcohols; esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)-propionic acid with mono- or multivalent alcohols; esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or multivalent alcohols; amides of 13-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid, such as e.g. N,N′-bis-(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)-N,N′-bis-(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)-trimethylene diamine or N,N′-bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine.
Preferred co-stabilizers include organic phosphites and/or organic phosphonites. These are well-known co-stabilizers for antioxidants.
The amount of antioxidants is usually between 0.05 and 10% by weight referring to the total mass of the fiber. The preference is given to amounts of antioxidants of 0.1 to 5% by weight, especially 0.5 to 3% by weight.
In addition to the thermoplastic aliphatic polyketone, the fibres according to the first embodiment of the invention contain at least one polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer and/or another aliphatic polyketone as a second polymer. In the second embodiment of the invention, polyamide and/or polyoxymethylene can also be used as a second polymer.
The proportion of aliphatic polyketone as the first polymer in the fibers of the invention is usually between 5 and 90% by weight, referring to the total mass of the fiber. Preferred portions of aliphatic polyketone as the first polymer range from 10 to 80% by weight, especially from 20 to 50% by weight.
The proportion of polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene as second polymer in the fibers according to the invention is usually between 10 and 95% by weight, referring to the total mass of the fiber. Preference is given to fractions in polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene ether ketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene as second polymer from 20 to 90% by weight, especially from 50 to 80% by weight.
Polyolefins, polyesters, polyurethanes, polyphenylene sulphides, polyphenylene sulfones, polyphenylene ethers, polyphenylene ketones, polyphenylene ether ketones, liquid crystalline polymers, other aliphatic polyketones, polyamides and/or polyoxymethylenes used according to the invention are known polymers, which have already been used for fiber production.
Examples of polyolefins are homo- or copolymers derived from ethylene and/or propylene, optionally in combination with other ethylenically unsaturated aliphatic hydrocarbons, such as α-olefins with four to eight carbon atoms. Polyethylene and polypropylene can be present in different densities and crystallinities. All these modifications are generally suitable for the use in the invention.
Examples of polyesters are thermoplastic polymers derived from aliphatic, cycloaliphatic and/or aromatic dicarboxylic acids or from their polyester-forming derivatives, such as from alkylesters, and from aliphatic, cycloaliphatic and/or aromatic divalent alcohols, such as ethylene glycol, propylene glycol and/or butylene glycol.
Other examples of polyesters include thermoplastic elastomeric polyesters (TPE-PE), such as polyesters containing recurrent ethylene terephthalate structural units and containing recurring polyethylene glycol terepthalate structural units. TPE-PE are known to the skilled person.
Another example of polyesters are polycarbonates. These are preferably used. Polycarbonates are formally polyesters of carbonic acid containing the recurring structural unit [R—O—CO—O]—, in which R is a residue of a divalent organic alcohol or phenol after removing the two alcohol groups. Preferably, R is the residue of an aromatic dihydroxy compound, a bisphenol. Preferred is residues R are derived from 2.2-bis (4-hydroxyphenyl)-propane (Bisphenol A), bis-(4-hydroxyphenyl)-methane (Bisphenol F), bis-(4-hydroxyphenyl)-sulfone (Bisphenol S), dihydroxydiphenyl sulfide, tetramethyl-bisphenol A or 1.1-bis-(4-hydroxyphenyl)-3.5 trimethylcyclohexane (BPTMC).
By using mixtures of the above components, the properties of the resulting polycarbonates can be varied. Cocondensates from Bisphenol A and BPTMC result in highly transparent and heat-resistant resins. It is also possible to incorporate higher functional alcohols/phenols, for example from 1.1.1-tris-(4-hydroxyphenyl)-ethane (THPE). This makes it possible to generate chain branches that positively influence the structural viscosity in the processing of the material.
Also preferred are aromatic-aliphatic polyester homo- or copolymers. Examples include polyethylene terephthalate homopolymers or copolymers containing ethylene terephthalate units. These preferred polymers are thus derived from ethylene glycol and optionally from other alcohols, as well as from terephthalic acid or its polyester-forming derivatives, such as terephthalic acid esters or chlorides.
In addition to or instead of ethylene glycol, these polyesters may contain structural units derived from other suitable divalent alcohols. Typical representatives of these are aliphatic and/or cycloaliphatic diols, such as propanediol, 1.4-butanediol, cyclohexane dimethanol or their mixtures.
In addition to or instead of terephthalic acid or its polyester-forming derivatives, these polyesters may contain structural units derived from other suitable dicarboxylic acids or from their polyester-forming derivatives. Typical representatives of these are aromatic and/or aliphatic and/or cycloaliphatic dicarboxylic acids, such as naphthalene dicarboxylic acid, isophthalic acid, cyclohexane dicarboxylic acid, adipic acid, sebacic acid or their mixtures.
Thus, fibers can also be produced containing other polyesters, such as polybutylene terephthalate, polypropylene terephthalate, polyethylene naphtalate homopolymer or copolymers containing ethylene naphthalate units.
These thermoplastic polyesters are known. The building blocks of thermoplastic copolyesters are preferably the above mentioned diols and dicarboxylic acids, or correspondingly constructed polyester-forming derivatives.
Polyesters are preferred, whose solution viscosities (IV values) are at least 0.60 dl/g, preferably from 0.80 to 1.05 dl/g, especially preferred from 0.80-0.95 dl/g (as measured at 25° C. in dichloro acetic acid (DCE)).
Polyesters used according to the invention can also be derived from hydroxycarboxylic acids.
Examples of polyamides that can be used in the second embodiment of the invention are thermoplastic polymers derived from aliphatic, cycloaliphatic and/or aromatic dicarboxylic acids or their polyamide-forming derivatives, such as from their salts, and of aliphatic, cycloaliphatic and/or aromatic divalent amines, such as hexamethylenediamine.
Other examples of polyamides include thermoplastic-elastomeric polyamides (TPE-PA), such as polyamides containing recurrent hexamethylene terephthalamide structural units and containing recurring polyethyleneglycol terephthalamide structural units. TPE-PA are known to the skilled person.
Preferably used polyamides are partially crystalline aliphatic polyamides produced from aliphatic diamines and aliphatic dicarboxylic acids and/or from cycloaliphatic lactames with at least 5 ring members or corresponding amino acids.
As educts aliphatic dicarboxylic acids, preferably adipic acid, 2.2.4- and 2.4.4-trimethyladipic acid, azelaic acid and/or sebacic acid, aliphatic diamines, preferably tetramethylene diamine, hexamethylene diamine, 1.9-nonane diamine, 2.2.4- and 2.4.4-trimethylhexamethylene diamine, the isomeric diaminodicyclohexylmethanes, diaminodicyclohexylpropane, bis-aminomethyl-cyclohexane, aminocarboxylic acids, preferred aminocaproic acid or the corresponding lactames are considered. Copolyamides from several of the monomers mentioned are included. Caprolactames are particularly preferred, and ε-caprolactame is particularly preferred.
Preferably, the aliphatic homo- or copolyamides used in the invention are polyamide 12, polyamide 4, polyamide 4.6, polyamide 6, polyamide 6.6, polyamide 6.9, polyamide 6.10, polyamide 6.12, polyamide 6.66, polyamide 7.7, polyamide 8.8, polyamide 9.9, Polyamide 10.9, polyamide 10.10, polyamide 11 or polyamide 12.
Polyesters and polyamides used according to the invention can also be derived from hydroxycarboxylic acids or from aminocarboxylic acids.
Examples of polyoxymethylenes that can be used in the second embodiment of the invention include homo- or copolymers containing recurring structural units of the formula CH2—O—.
Examples of polyurethanes are homo- or copolymers derived from aromatic or (cyclo)aliphatic diisocyanates and from (cyclo)aliphatic or aromatic diols.
Polyurethanes, for example, contain recurrent structural units of the formula —C6H4—NH—CO—O—C2H4—O—CO—NH—.
Other examples of polyurethanes include thermoplastic-elastomic polyurethanes (TPE-PU). TPE-PU are known to the skilled person.
Examples of polyphenylene sulfides include poly-p-phenylene sulfides, such as homo- or copolymers containing recurring structural units of para —C6H4—S—.
Examples of polyphenylene sulfones include poly-p-phenylene sulfones, such as homo- or copolymers containing recurring structural units of para —C6H4—SOx—, with x meaning a number between 1 and 2.
Examples of polyphenylene ethers include poly-p-phenylene ethers, such as homo- or copolymers containing recurring structural units of para —C6H4—O—.
Examples of polyphenylene ketones include poly-p-phenylene ketones, such as homo- or copolymers containing recurring structural units of para —C6H4—CO—.
Examples of polyphenylene etherketones include poly-p-phenylene etherketones, such as copolymers containing recurring structural units of para —C6H4—CO and of recurring structural units of para —C6H4—O—.
Examples of liquid crystalline polymers include liquid crystalline aromatic polyesters, such as homo- or copolymers containing recurring structural units derived from para-hydroxybenzoic acid.
In the fibers according to the invention, the first polymer and the second polymer may be present as a polymer mixture or the polymers may be present in the form of two or more fiber components, which are spatially separated from one another but which are interrelated among each other.
Preference is given to fibers in which the first polymer and the second polymer are present as a polymer mixture, with one of the polymers, preferably the aliphatic polyketone, forming a matrix and the other polymer being dispersed in the form of fibrils in the matrix.
Examples of this embodiment are fibers in the form of island-in-the-see fibers, in which a polymer component in the form of fibrils is arranged in the polymeric matrix component. The fibrils are preferably aligned in the longitudinal direction of the fiber and thus increase the tensile strength and the module of the fiber.
For example, by adding 1 to 7% of liquid-crystalline polyester, the tensile modulus of a monofilament made of aliphatic polyketone could be significantly increased (see Example 4)
Multi-component fibers can be cited as examples of fibers in which the polymers are present in the form of two or more fiber components, which are spatially separated from one another but which are interrelated among each other.
The at least two polymers in the fiber according to the invention can therefore be present as a polymer mixture or the at least two polymers can be present in the form of two or more fiber components, which are spatially separated from one another but which are interrelated among each other. Examples of this latter embodiment are multi-component fibers, which can be present, for example, as core-sheath fibers or as side-by-side fibers.
Fibers containing a mixture of aliphatic polyketone and polycarbonate are preferred.
Fibers are preferred, in which one of the polymer components, preferably the polymer different from aliphatic polyketone, is present in the form of fibrils in a polymer matrix component.
Fibers are particularly preferred, in which the aliphatic polyketone forms a polymer matrix and another polymer selected from the group of polyolefins, polyesters, polyphenylene ketones, polyphenylene etherketones and/or liquid crystalline polymers is present in the form of fibrils in the polymer matrix component. Especially preferred these fibers contain a liquid crystalline polymer as another polymer.
Also preferred are core-sheath fibers with a sheath of aliphatic polyketone and with a core of polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene, wherein in case that aliphatic polyketone is in the core, the melting point of this is at least 5° C., preferably at least 10° C. and in particular at least 20° C. higher than the melting point of the aliphatic polyketone in the sheath.
Particularly preferred are core-sheath fibers with a sheath of aliphatic polyketone and with a core of polyester, polyphenylene sulfide, polyphenylene ether, polyphenylene ketone or polyphenylene etherketone.
Also preferred are side-by-side fibers with a fiber part made of aliphatic polyketone and with another fiber part being in contact therewith made of polyolefin, polyester, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene, wherein in case that aliphatic polyketone is present in the additional fiber part, the melting point thereof is at least 5° C., preferably at least 10° C. and in particular at least 20° C. higher than the melting point of the aliphatic polyketone in the other fiber part.
Also particularly preferred are side-by-side fibers with a fiber part made of aliphatic polyketone and with another fiber part being in contact therewith made of polyester, polyphenylene sulfide, polyphenylene ether, polyphenylene ketone or polyphenylene etherketone.
Also preferred are side-by-side fibers with a fiber part made of aliphatic polyketone and with another fiber part being in contact therewith made of polyolefin, polyester, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone and/or liquid crystalline polymer.
Especially preferred are core-sheath fibers, in which the sheath contains aliphatic polyketone as a polymer and the core contains one or more of the above mentioned second polymers, and wherein in the core and/or in the sheath at least one additive is contained, which imparts a certain functionality to the fiber.
Also particularly preferred are side-by-side fibers, in which one fiber part contains aliphatic polyketone as a polymer and the other fiber part contains one or more of the above mentioned second polymers as well as at least one additive, which imparts a certain functionality to the fiber.
Also particularly preferred are core-sheath-fibers with a sheath of aliphatic polyketone and with a core of further aliphatic polyketone, the melting point of which is at least 5° C., preferably at least 10° C. and in particular at least 20° C. higher than the melting point of the aliphatic polyketone in the sheath.
For example, by using core-sheath-structures with cores made of polyesters, such as PET or polycarbonate, or made of aliphatic polyketones with a higher melting point than the sheath polymer it is possible to manufacture fibres with good thermal stability. Compared to fibers made of aliphatic polyketones, these are characterized by high tensile and bending moduli and therefore by high stability, for example in the case of core-sheath-fibers with PET in the sheath. These fibers often show good dimensional stability under tension at temperatures up to 150° C.
In a third embodiment of the invention, fibers are provided in which the fiber surface is modified by selected polymer particles dispersed in the matrix polymer. A functionalization and texturing of the surface can be achieved by adding polysiloxane particles, such as PMSQ particles and/or poly(meth) acrylate particles, such as crosslinked PMMA microballs. Typical diameters of these particles range from 0.2 to 100 μm. In this way, a microtexturing of the surface can be created and the surface properties of the fiber can be modified. Above all, this reduces the friction area and significantly improves the friction properties. In addition, the cleaning properties of the fiber are improved.
In this embodiment, the invention concerns fibers, in particular monofilaments, containing a matrix of aliphatic polyketone and therein dispersed polysiloxane particles and/or poly(meth)acrylate particles, which have a diameter from 200 nm to 100 μm.
The particles can have any shape. Examples of this are particles with rotationally symmetrical shape, especially spheres, but also with irregular shape. These particles are present as micropowder. The diameter of these particles is in the range from 0.2 to 100 μm, preferably from 1 to 50 μm. For particles with varying diameters the indication of the diameter refers to the largest diameter of the particle.
Monofilaments containing spherical particles from polysiloxane, whose diameter is from 1 to 50 μm, are preferred.
The particles are dispersed as micropowders in the matrix polymer. In general, 0.001% by weight to 8% by weight, preferably 0.02% by weight to 5% by weight of particles are dosed to the matrix polymer. The particles are present in the matrix polymer as a heterogeneous phase. The particles may be present as individual particles in the matrix polymer and/or as aggregates of different individual particles.
The polysiloxanes used according to the invention are a group of synthetic polymers in which silicon atoms are linked via oxygen atoms. The polysiloxanes used according to the invention are also called silicones.
These can be linear or crosslinked polysiloxanes or polysiloxanes with cage structures, so-called silsesquioxanes.
Preferably used are linear or crosslinked polysiloxanes containing the recurring structural element SiR1R2—O— or silsesquioxanes of the formula R1SiO3/2, In which R1 is C1-C6-alkyl, in particular methyl, and R2 is C1-C6-alkyl or phenyl, in particular methyl or phenyl.
Especially preferred are monofilaments containing polysiloxanes, which are linear or crosslinked polydimethylsiloxanes or a polymethylsilsesquioxane.
The poly(meth)acrylates used according to the invention are a group of synthetic polymers derived from esters of acrylic acid and/or from esters of methacrylic acid. In addition, poly(meth)acrylates may have other monomer units copolymerized with esters of acrylic acid and/or with esters of methacrylic acid. The poly(meth)acrylates used according to the invention can be linear or preferably crosslinked poly(meth)acrylates.
Preferably used as poly(meth)acrylates are homo- or copolymers of methyl acrylate or of methyl methacrylate.
Examples of the above mentioned additives are electrically conductive additives, lubricants, anti sticking agents, propellants for the production of foamed or porous fiber surfaces, pigments and/or fillers.
Preferred multi-component fibers contain a part made of aliphatic polyketone and another part in contact therewith from one of the above polymer types, especially polyester, particularly preferred TPE-PE, or in particular polyurethane, TPE-PU being particularly preferred, in which the aliphatic polyketone mainly improves the anti-friction properties and the second polymer component mainly improves other properties, such as improved grip properties mediated by TPE-PE or TPE-PU or hot glue properties, for example, mediated by co-polyester.
The aliphatic polyketones and/or the further polymers selected from the group consisting of polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene which are used according to the invention may contain additional additives that give the produced fibers a desired property. Examples of such additives include UV stabilizers, pigments, dyes, fillers, matting agents, reinforcements, crosslinking agents, crystallization accelerators, lubricants, flame retardants, antistatics, hydrolysis stabilizers, plasticizers, impact strength modifiers and/or other polymers that differ from aliphatic polyketones, polyolefins, polyesters, polyphenylene sulfides, polyphenylene sulfones, polyphenylene ethers, polyphenylene ketones, polyphenylene etherketones, liquid-crystalline polymers, other aliphatic polyketones, polyamides and/or polyoxymethylene. These additives are known to the skilled person.
Examples of preferred UV stabilizers include UV-absorbing compounds, such as benzophenones or benzotriazoles, or compounds of HALS-type (hindered amine light stabilizer”).
Examples of preferred pigments include carbon black, titanium dioxide or iron oxides.
Examples of preferred dyes include anionic dyes, acid dyes, metal complex dyes, cationic or basic dyes and dispersion dyes.
Examples of preferred fillers include carbonates, like chalk or dolomite, silicates, such as talcum, mica, kaolin or sulfates, such as barite, or oxides and hydroxides, such as quartz powders, crystalline silica, aluminum or magnesium hydroxides or magnesium, zinc or calcium oxides.
An example of a preferred matting agent is titanium dioxide.
An example of a preferred reinforcement material is glass fibers.
Examples of preferred crosslinking agents include multi-valent carboxylic acids and their esters, multi-valent alcohols, polycarbonates or polycarbodiimides.
Examples of preferred crystallization accelerators include carboxylic acid esters.
Examples of preferred lubricants include polyolefin waxes, fatty acids or their salts, fatty alcohols, fatty acid esters, silicones, polymethacrylate beads, polysiloxanes and, in particular, PMSQ, as described in EP 2,933,361 A1.
Examples of preferred flame retardants include phosphorus-containing compounds, organic halogen compounds, nitrogen-containing organic compounds or combinations thereof.
Examples of preferred antistatics include carbon black, graphite, graphene or carbon nanotubes.
Examples of preferred hydrolysis stabilizers include carbodiimides or epoxidized compounds.
Examples of preferred processing aids include waxes or longer-chain carbon acids or their salts, aliphatic, aromatic esters or ethers.
Examples of preferred plasticizers include diethylhexyl phthalate, alkyl sulfonic acid esters of phenol, citric acid triethylester, diethylhexyl adipate or diethyloctyl adipate.
Examples of preferred impact strength modifiers include thermoplastic elastomers, such as thermoplastic copolyamides, thermoplastic polyester elastomers, thermoplastic copolyesters, olefin-based thermoplastic elastomers, styrol-copolymers, such as SBS, SEBS, SEPS, SEEPS, MBS, ABS, SAN or SBK, thermoplastic urethane-based elastomers, thermoplastic vulcanisates or crosslinked olefin-based thermoplastic elastomers, in particular PP/EPDM, or polycarbonate.
Examples of preferred other polymers include fluoropolymers, such as polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer or polychlorine-trifluoroethylene.
The proportion of these additional additives in the fiber according to the invention can usually be up to 10% by weight, in relation to the total mass of the fiber. Preferably, these additional additives are used in quantities from 1 to 5% by weight.
In a preferred embodiment, the present invention concerns melt-spun core-sheath-fibers containing a sheath of thermoplastic ethylene/propylene-/CO-terpolymer and a core of polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene, with the mass of the sheath being 5 to 50% by weight and the mass of the core being 95 to 5% by weight and the core and/or the sheat optionally contain a total of up to 10% by weight of additives, in particular sterically hindered phenols, UV stabilizers, pigments, dyes, fillers, matting agents, crosslinking agents, crystallization accelerators, lubricants, flame retardants, antistatics, hydrolysis stabilizers, plasticizers, impact strength modifiers and/or fluoropolymers, with percentages referring to the total mass of fibers.
The term “fiber” is to be understood in the context of this description as a linear structure that is thin in relation to its length. Typically, the ratio of length to diameter of a fiber is at least 5:1. Fibers within the meaning of this description can be endless (and are then called filaments) and can be cut to finite length (and are then called bristles or staple fibers). Fibers can also be present in the form of several filaments or in the form of several staple fibers. The invention preferably concerns fibers in the form of monofilaments, bristles or staple fibers.
The cross-sectional form of the fibers according to the invention can be arbitrary. They can have irregular cross-sections, point- or axle-symmetrical cross-sections, such as round, oval or n-angular cross-sections, with n being to larger or equal to 3. The cross-sectional shape of the fibers can also be multilobal.
The strength (titer) of the fibers according to the invention can be expressed by the thread weight. 1 dtex corresponds to a fiber mass of 1 g per 10 km of fiber length. Typical thread weights range from 1 to 100000 dtex.
The titer of the preferred monofilaments, bristles or staple fibers of the invention is preferably at least 10 dtex and can fluctuate in wide areas. Preferred titers of monofilaments, bristles or staple fibers range from 10 to 30000 dtex, especially in the range of 45 to 20000 dtex.
The components required to produce the fibers of the invention are known per se, are partly commercially available or can be produced according to processes well-known per se.
The fibers of the invention are preferably used for the production of textile fabrics, especially of woven fabrics, laid fabrics, knitted fabrics, meshwork or knittings. These textile fabrics are produced using well-known techniques.
The production of the fibers according to the invention can be carried out by a well-known melting spinning process, combined with one or more stretching and fixing of the obtained fibers.
The invention also concerns a method of the polyketone fibres described above.
In a first embodiment of the process according to the invention, polyketone raw material is dosed together with the sterically hindered phenol into an extruder and is pressed through a nozzle plate in molten form. The nozzle plate may have one or more spinning capillaries. The resulting filament is detracted from the spinning capillary. The detraction speed is usually between 1 and 120 m/min, especially between 5 and 50 m/min.
The sterically hindered phenol and/or other additives can be dosed in the form of a master batch containing the additive/additives and a thermoplastic polymer, with the polymer being selected from the group consisting of polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene.
The nozzle plate is usually part of a spinning pack consisting of filter devices for the molten spinning mass and of the downstream nozzle plate.
The temperature of the spinning mass must be chosen in such a way that, on the one hand, sufficient flowability of the spinning mass is warranted and that, on the other hand, the thermal stress on the polyketone is limited, so that crosslinking and degradation reactions as well as gel formation in the spinning mass are kept within limits or even can be completely suppressed.
In the first embodiment of the inventive process, a polyketone raw material stabilized with antioxidant and a selected polymer derived from the master batch are used. Here, the temperatures of the spinning mass when leaving the spinning capillaries can be in the range from 200 to 300° C., preferably from 220 to 240° C.
The diameter of a spinning capillary is selected by the skilled person according to the desired fiber weight. Typical diameters range from 10 μm to 5 mm, and for monofilaments or bristles preferably in the range from 0.1 to 1 mm. These specifications correspond to the diameter of the hole at the exit side of the polymer mass.
Integrated into the spinning process are one or more stretchings with thermal exposure that give the thread the desired end properties. The skilled person is aware of such procedures.
Preference is given to the filament being stretched several times after spinning, in particular with an overall stretching ratio in the range from 1:3 to 1:15, preferably in the range from 1:4 to 1:8.
Particularly preferred is at least one relaxation step (fixing step) is followed by the stretching step(s). The stretched filaments are treated thermally while maintaining the fiber tension, so that the stresses built into the filament can be reduced.
The generated filaments are then fed into a suitable storage form, for example, recoiled or cut into staple fibres in a cutting device.
In a second embodiment of the inventive process, a polymer blend is made of aliphatic polyketone and polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer and/or further aliphatic polyketone and is spun through a conventional spinning capillary as described above or aliphatic polyketone on the one hand and polyolefin, polyester, polyurethane, polyphenylene sulfide, polyphenylene sulfone, polyphenylene ether, polyphenylene ketone, polyphenylene etherketone, liquid crystalline polymer, further aliphatic polyketone, polyamide and/or polyoxymethylene, on the other hand, are spun through spinning capillaries to produce multi-component filaments. Apart from that, the procedure of the second embodiment corresponds to the procedure of the first embodiment.
In the second embodiment of the process according to the invention, an antioxidant, preferably a sterically hindered phenol, may be present in the polymer components. However, it can also be worked without an antioxidant.
Also in the second embodiment, the temperature of the spinning mass must be chosen in such a way that, on the one hand, sufficient flowability of the spinning mass is warranted, and, on the other hand, the thermal stress on the aliphatic polyketone and on the other polymer components remains limited, so that crosslinking and degradation reactions as well as gel formation in the spinning mass can be kept within limits or can be even completely suppressed.
In the second embodiment of the inventive process, polymer raw materials can be used that are not necessarily stabilized with anti-oxidant. Here, the temperatures of the spinning mass when leaving the spinning capillaries can be in the range from 200 to 300° C., preferably from 220 to 260° C.
In a third embodiment of the process according to the invention, a blend of aliphatic polyketone and pf polysiloxane particles and/or of poly(meth)acrylate particles is spun through a conventional spinning capillary as described above.
The invention concerns a process for the production of the polyketone fibers described above comprising the following measures:
The invention concerns a process for the production of the polyketone fibers described above comprising the following measures:
The invention concerns a further method for the production of the polyketone fibers described above comprising the following measures:
The invention also concerns a process for producing the polyketone fibers described above, comprising the following measures:
The invention concerns a process for the production of the polyketone fibers described above comprising the following measures:
Preferably the fibers of the invention, especially in the form of monofilaments, are used for the production of textile fabrics, especially of woven fabrics, spiral meshes, laid-fabrics or knittings. These textile fabric constructions are preferably suitable for use in sieves or conveyor belts. Another important area of application is fibers for brushes or for oral hygiene as well as for personal care, but also staple fibers in composite materials with, for example, concrete as matrix material.
The invention therefore also concerns textile fabrics containing the fibers described above, in particular textile fabrics in the form of a woven fabric, knitting, knitted fabric, meshwork or laid-fabric.
The fibers according to the invention are characterized by a combination of excellent mechanical properties, such as high tensile moduli and good loop and knot strength, excellent bending recovery, and very good glide properties as well as by high abrasion resistance.
They can be used in a wide variety of fields. They are preferably used in applications where increased wear and tear and high mechanical stress can be expected, especially in hot-wet environments. Examples include use in screen cloth and filter cloth for gas and liquid filters, in dryer-belts, for example in the production of food or, in particular, of paper, and in brushes for cleaning purposes of all kinds, for example in household, personal care, such as in oral hygiene, e.g. as a toothbrush. Other applications include use as fluidization tapes, process belts for the board industry, conveyor belts and process belts in the manufacture of non-wovens, such as spunbond, meltblown, airlaid, wetlaid, spunlaced, or thermobonded, or as staple fibers for concrete or composite reinforcement.
The invention also concerns the use of the fibers described above, in particular in the form of monofilaments, as paper machine clothings, in conveyor belts and in filtration sieves.
In another preferred embodiment, various stabilizers, such as antioxidants for thermal stabilization and/or hydrolysis stabilizers, are added to the fibers of the invention. This variant is particularly suitable for drying processes in humid environments, e.g. in the drying section of paper machines as well as in other continuous industrial drying and filtration processes, such as in the drying of wood chipboards, of pellets to be used as fuels or, more generally, of biomass.
The fibers of the invention are particularly preferred used in the form of monofilaments as paper machine clothing in the sheet formation section and/or in the drying section of the paper machine.
These monofilaments are used, for example, in the lower portion of forming sieves in paper machines. This can be performed by 100% as a lower portion and/or as a so-called alternating shot (changing the said monofilament alternating with e.g. polyamide, polyester or polyphenylene sulfide monofilaments). The aliphatic polyketone causes a significant reduction in the sliding friction and thus a significant reduction in the drive power of the paper machine, resulting in a considerable energy saving. Furthermore, the monofilament according to the invention is more abrasion-resistant than comparable monofilaments made of polyethylene terephthalate, polybutylene terephthalate or polycyclohexaneterephtalate or of polyamides without the use of aliphatic polyketone.
The fibers of the invention are particularly preferred used in the form of filtration cloth or knittings, as support for membranes with a wide mesh and high dimensional stability (e.g. as support for reverse osmosis membranes, which must resists continuous pressures of 50 bar), and as process cloth for the fabrication of paper and nonwovens.
In addition, the fibers according to the invention are well suited for the production of conveyor belts, in which a combination of dimensional stability and good sliding properties is required.
Another preferred field of application of the fibers according to the invention is their use in brushes, especially in toothbrushes. Here the fibers according to the invention are usually used in the form of bristles.
For this purpose, the monofilaments are available in endless or cut form grouped into bundles or as brushes.
The present invention is described in more detail by the following examples. These examples are for explanation of the invention only and are not to be understood as a limitation.
Different aliphatic polyketones were used in the following examples. The sheath polymers were the type M630A with a melting point (according to ASTM D3418) of 222° C. or alternatively a low-melting variant, such as the type M410F with a melting point (according to ASTM D3418) of 199° C. or the type M620A with a melting point (according to ASTM D3418) of 207° C. The core polymers, for example, were a semi-crystalline PET (polyethylene terephthalate) with a melting point of 254° C. or a polycarbonate (such as Makrolon 2456 from Covestro) or an aliphatic polyketone with a high melting point (type M630A from Hyosung) or a blend of these components.
Combination of two commercially available aliphatic polyketones, a higher melting one in the core—type M630A from Hyosung Polyketone—and a low-melting one in the sheath type M410F from Hyosung Polyketone.
To produce such a bicomponent monofilament, both components were co-extruded in one production step. The relative feed rate allows the core/sheath ratio to be adjusted, which here was 70/30. In the process, the monofilament was stretched several times under temperature exposure. The total stretching ratio was 1:3.7.
By using the above process bicomponent monofilaments with the following characteristics were obtained:
Combination of the two polyketone variants in one monofilament allows a thermally induced physical combination at the monofilament crossing points. As a result, fabric structures, for example, have an increased shear stability. Furthermore, such crosslinked structures show thickening at the crossing points. This property is of interest due to positive flow properties, e.g. for fluid filtration.
A stabilized polyethylene terephthalate (PET) 99.3% raw material type 12 from Invista with 0.7% Stabaxol from Lanxess was used in the core and an aliphatic polyketone—type M630A from Hyosung Polyketone was used in the sheath.
Such a monofilament was co-extruded in one production step. The relative feed rate allows the core/sheath ratio to be adjusted, which here was 70/30. In the process, the monofilament was stretched several times under temperature exposure. The total stretching ratio was 1:4.3.
By using the above process bicomponent monofilaments with the following characteristics were obtained:
The combination of PET and aliphatic polyketone in one monofilament combines the properties common to PET with the surface properties of polyketones. As a result, fabric structures can be produced that have a significantly reduced friction value and that thus can lead to energy savings when used, for example, in conveyor belts. The advantage of the PET core is in the processing properties of the monofilament in the weaving process (e.g. identical floating) that are analogous to PET.
An aliphatic polyketone type M630A from Hyosung Polyketone—was used as a matrix polymer. In addition, 1.0% by weight of polysiloxane beads type PMSQ E+580 from Coating Products with an average diameter of 8 μm were dispersed in the matrix polymer.
The obtained monofilament shows the following characteristics:
As shown in EP 2 933 961 A1, the addition of polysiloxane beads reduces the friction coefficient against metal or ceramic through the resulting surface structure of the monofilament. This is also the case in the combination with aliphatic polyketone (see table below). The monofilaments of the comparative experiments V1 to V5 referred to in the table are described below.
It was proceeded as in Example 3. As a matrix polymer, aliphatic polyketone—type M630A from Hyosung Polyketone was used. As a second polymer component, 7% of a liquid crystalline polymer (liquid crystal polymer, LCP) polyester from hydroxybenzoic acid and hydroxynaphthalinic carboxylic acid, type Vectra A950 from Ticona, was added. The obtained monofilament showed the following characteristics:
The combination of polyketone with a LCP showed an increase in tenacity while simultaneously increasing the E-module. This is due to a synergistic effect of LCP fibrils in the polyketone matrix. The increase in the E-module is shown in the table below. The monofilaments of the comparative experiments V1 to V2 referred to in the table are described below.
Aliphatic polyketone—type M630A from Hyosung Polyketone was used at 100%.
To produce a monofilament, the polyketone was extruded, spun and stretched several times under temperature exposure.
Depending on the stretching ratio, the following characteristics were found:
A commercially available PET type RT 12 from Invista was used at 100%. It was proceeded as in the comparative examples V1 to V4. The obtained monofilament showed the following characteristics:
| Number | Date | Country | Kind |
|---|---|---|---|
| 202017002839.5 | May 2017 | DE | national |
| PCT/EP2018/000265 | May 2018 | EP | regional |
This application is a national phase application of PCT/EP2018/000265 FILED May 18, 2018, which was based on application DE 20 2017 002 839.5 FILED May 30, 2017. The priorities of PCT/EP2018/000265 and DE 20 2017 002 839.5 are hereby claimed and their disclosures incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP18/00265 | 5/18/2018 | WO | 00 |
