ES2891998T3 - Bristle of a plastic filament, brushes with such bristles and methods for the production of such bristles - Google Patents

Abstract

Bristle (3), which is formed from a section of a plastic filament, in which the polymer matrix of the plastic filament contains at least 70% by mass, with respect to the complete polymer matrix, of at least one thermoplastic aliphatic polyketone, which is composed of carbon monoxide and alkyl units, in which the polymer matrix of the plastic filament also contains at least one additive from the group of antioxidants and UV stabilizers, and in which the maximum diameter of the Plastic filament is between 0.01 mm and 0.13 mm.

Description

DESCRIPTION

Bristle of a plastic filament, brushes with such bristles and methods for the production of such bristles

[0001] The invention relates to a bristle that is formed from a section of a plastic filament, a brush with at least one bristle carrier and a plurality of bristles attached to the bristle carrier, in particular in the form of a brush of teeth, and to a method for producing a bristle of the type mentioned above.

[0002] The cleaning effect of brushes, in particular, but not exclusively, of toothbrushes, depends to a large extent, on the one hand, on the geometry of the individual bristles and, on the other hand, on their material, so it is often necessary to design the bristles with the smallest possible diameter, so that they are able to develop their cleaning effect even in very narrow gaps, for example in narrow interdental spaces. At the same time, however, the bristles must have a certain flexural strength and durability for this purpose.

[0003] In practice, therefore, mainly brushes have proven themselves, whose bristles are made of monofilaments, so-called monofilaments, made of plastic, which can be made relatively thin with a suitable material selection and also offer the possibility of structuring or profiling its outer surface in order to further improve the cleaning effect, especially in narrow spaces, due to the scraping effect. In addition, the bristles of the brushes formed from said filaments ensure additional properties, such as, for example, a certain coloration, stability against degradation due to thermal stress or chemical action, including enzymatic action as a result of contact with saliva. , as high as possible abrasion resistance, dimensional stability, flexural strength, flexural recovery and the like.

[0004] Synthetic yarns made from melt-spinnable thermoplastic polymers are generally used for bristles of the generic type, in which, for cost reasons, standard polymers that have been known for a long time are used, for example from polyolefins such as polyethylene (PE) or polypropylene (PP), of polyamides such as polyamide 6 (PA 6) or polyamide 6.6 (PA 6.6), or of polyesters such as polybutylene terephthalate (PBT), provided that filaments made from these polymers can meet with the desired requirements. Furthermore, the aforementioned polymers meet the physiological requirements for harmlessness that are necessary in particular for their use in toothbrushes.

[0005] However, there are limits to the mechanical properties and thus the smallest possible diameter of such bristles, which is why known toothbrushes typically have bristles with a diameter between about 0.225mm and 0.25mm. ("hard"), with a diameter in the range of about 0.2 mm ("medium"), or in the range of about 0.15 mm to about 0.18 mm ("soft"). For example, polyamide bristles tend to swell when in contact with water, which impairs their flexural stiffness. In contrast, bristles made from polyalkylene terephthalates, such as polybutylene terephthalate (PBT), for example, prove to be less sensitive, but for the reasons mentioned above, the diameter of the bristles cannot be significantly less than about 0.15 mm. mm.

[0006] In addition, thermoplastic aliphatic polyketone filaments are known from the state of the art, for example EP 0310171 A2 describes melt-spun fibers made of ethylene/propylene/CO terpolymers, which have high tensile strengths and high modulus. of elasticity and are therefore proposed for use as tire cord or for the production of spunbonded non-woven fabrics, which can be used for the production of roof base layers or suitable as geotextiles.

[0007] From WO 2016/190594 A2 and WO 2016/190596 A2, wet-spun fibers made of ethylene/propylene/CO terpolymers are also known, which have excellent strength and elongation values and are also characterized by high resistance to water and heat and good thermal conductivity. Various uses are proposed as application areas for these fibers, such as the production of ropes, hoses, nets, Spunbond fabrics, airbags or protective garments, as well as their use as geotextiles, as reinforcing fibers in composite materials, such as belts, nets security, conveyor belts, fishing lines or tennis strings.

[0008] More relevant information about the invention can be found in documents US5175210, WO0020512, KR20100010130 and DE19757607. In principle, the melt and wet spinning processes are suitable for the production of generic bristle filaments, in which the dissolved polymer is spun into yarns through a spinning capillary during wet spinning and the solvent is recovered. as completely as possible and fed back into the production process. However, it cannot be avoided that small amounts of the used solvent remain in the finished fiber, while it is desirable to provide a solvent-free fiber to minimize any potential safety risk, including health hazard, caused by presence of solvent residues on the fiber.

[0009] In practice, therefore, mainly melt-spinning processes are used, in which higher degrees of crystallization can also be achieved, which can have an advantageous effect on the mechanical properties of the fiber. However, melt-spinning processing often has to take place at significantly higher temperatures than wet-spinning, which can lead to accelerated degradation or cross-linking reactions of the polymer and, in turn, have a negative effect. in the properties of the fiber produced or lead to crosslinking reactions of the polymer, which can limit its workability in the extrusion process.

[0010] The invention is based on the objective of proposing a suitable bristle for brushes, in particular for toothbrushes, which can be manufactured easily and economically, avoiding as far as possible the disadvantages mentioned above and, however, It has sufficient bending stiffness and durability with the smallest possible diameter. It also relates to a brush, in particular in the form of a toothbrush, with such bristles and to a method of producing such bristles.

[0011] Regarding the production technology, this objective is achieved with a bristle of the type mentioned at the beginning, which is formed from a section of a plastic filament, in which the polymeric matrix of the plastic filament contains at least 70% by mass, with respect to the complete polymeric matrix, of at least one thermoplastic aliphatic polyketone, which is composed of carbon monoxide units (CO units) and alkyl units, in which the polymeric matrix of the filament plastic also contains at least one additive from the group of antioxidants and UV stabilizers, and in which the maximum diameter of the plastic filament is between 0.01 mm and 0.13 mm.

[0012] Furthermore, the invention provides a brush with at least one bristle carrier and a plurality of bristles attached to the bristle carrier, in particular in the form of a toothbrush, to achieve this goal, at least some of the bristles of the bristle carrier being type mentioned above.

[0013] Finally, to achieve this objective in terms of process engineering, the invention provides a method for producing such a bristle comprising the following steps:

(a) Providing a spinning mass containing at least 70% by mass of at least one thermoplastic aliphatic polyketone, which is composed of carbon monoxide units (CO units) and alkyl units, and in which the al least one thermoplastic aliphatic polyketone, it contains in particular up to 10% by mass of at least one additive from the group of antioxidants and UV stabilizers;

(b) Extruding the spinning mass according to step (a) through at least one spinneret with one or more spinning capillaries with a diameter of maximum 1.0 mm, in particular maximum 0.8 mm , preferably a maximum of 0.4 mm, in which the temperature of the spinning mass on the exit side of the spinning capillary(s) is set in the range from 190 °C to 300 °C, in particular in in the range of 200°C to 270°C, preferably in the range of 220°C to 260°C;

(c) Extracting the formed filament at an extraction speed in the range of 1 to 200 m/min, in particular 5 to 50 m/min, preferably with a selection of the ratio between the extraction speed and the output speed of the spinning mass of the spinning capillary of more than 1;

(d) drawing the formed filament once or multiple times;

(e) optionally winding the formed filament; and

(f) Cutting the formed filament to size while retaining the bristles.

[0014] The plastic filaments according to the invention, which are mainly manufactured from thermoplastic aliphatic polyketones, which are formed from carbon monoxide units (CO units) and alkyl units, are characterized by a unique combination of properties, which makes it possible to use them as dental filaments, in particular for toothbrushes. The polyketones according to the invention exhibit high mechanical, hydrolytic and chemical resistance, for example against weak acids or bases and against saliva. They also possess a pronounced balance between material stiffness and toughness, as well as exceptional abrasion resistance, with only comparatively little change in the material's mechanical properties, such as flexural and tensile strength, even when wet. , so that the plastic filament according to the invention with a very small diameter between about 0.01 mm and about 0.13 mm is capable of optimally fulfilling the intended cleaning effect. The polyketone-based plastic filament mentioned above benefits, in particular, from high re-straightening values in both air and water and its high flexural strength with simultaneous physiological harmlessness, so that the plastic filament for care dental can be provided with a very small diameter, but still achieves a cleaning effect equal to or even better than conventional filaments based on polyamides or the like with larger diameters, which also cannot develop their cleaning effect in very narrow (interdental) spaces. As a result, the plastic filaments according to the invention based on aliphatic polyketones The aforementioned thermoplastics are able to penetrate deeper into the (interdental) spaces or gum pockets and also to clean these areas better than is possible with filaments of conventional materials according to the state of the art.

[0015] However, a disadvantage of the thermoplastic polyketones used as bristle materials according to the invention, which are composed of carbon monoxide and alkyl units, is that they generally have unsatisfactory oxidation resistance as well as relatively poor strength. to electromagnetic radiation in the ultraviolet spectrum, which has proven to be intolerable for brushes in general, and toothbrushes in particular, which must meet the highest safety and hygiene standards. The invention counteracts this in that the polymeric matrix of the plastic filament, from whose sections the bristles according to the invention are formed, additionally contains at least one additive from the group of physiologically harmless antioxidants and UV stabilizers described in more detail below. which have proven to be particularly suitable.

[0016] A brush, such as a toothbrush, which contains the bristles according to the invention, either exclusively or in particular partially, can have any known shape, the bristles being able to be arranged, for example, in bundles of bristles. However, due to the very small diameter of its bristles of a maximum of about 0.13 mm, the brush can have more bristles than is the case in the prior art, such as at least about 5,000 bristles, in particular at least about 5,500. bristles, preferably at least about 6000 bristles so that its cleaning effect can be further enhanced. Furthermore, it was found that the bristles according to the invention are also particularly suitable for sonic and ultrasonic toothbrushes.

[0017] The thermoplastic aliphatic polyketone used for the plastic matrix of the bristles according to the invention consists in particular exclusively of carbon monoxide units or CO units and alkyl units, whereby the aliphatic polyketones are copolymers or terpolymers with structural units of the formula -R-CO-, which are mostly, but not necessarily exclusively, alternately arranged, but may also be mainly randomly arranged. "R" is an alkyl radical, preferably a divalent aliphatic radical with from two to six carbon atoms, which is a divalent ethyl, propyl, butyl, pentyl and/or hexyl group.

[0018] In the melt-spinning process according to the invention for the production of plastic filaments based on thermoplastic aliphatic polyketones, a spinning mass is initially selected that contains at least about 70% by mass of at least one of such polyketones and, in particular, up to about 10% by mass of at least one additive from the group of antioxidants and UV stabilizers. This yarn mass is metered into a melt extruder, which may be, for example, a single screw extruder with a length to diameter ratio of from about 20 to about 40, in particular from about 25 to about 30. The extruder screw can advantageously be divided into three parts and has an area for stretching the spun dough and for melting it, an adjoining area for compression and homogenization, and an adjoining area in turn for expelling the plasticized spun dough. The extruder may preferably comprise several zones for melting and homogenizing the spun dough, all zones being able to operate essentially at the same temperature or with a descending or ascending temperature profile or also with a temperature profile that presents maximum and/or minimum temperatures. .

[0019] The plasticized spinning mass is then pressed in molten form through a spinneret, which may have one or more spinning capillaries, the diameter of which has a maximum of about 1.0 mm, in particular a maximum of about 0 0.8 mm, preferably a maximum of approx. 0.4 mm (depending on the diameter of the perforation on the outlet side of the polymer mass), the temperature of the spinning mass being established on the outlet side of the capillary or capillaries of yarns in the range from about 190 °C to about 300 °C, in particular in the range from about 200 °C to about 270 °C, preferably in the range from about 220 °C to about 260 °C, for example in in the range from about 220°C to about 250°C, such as in the range from about 237°C to about 242°C (respectively when exiting the spinning capillaries). The spinneret may generally be part of a spinpack which distributes the melt flow to the existing spinning capillaries and builds up the pressure necessary for spinning and which may advantageously comprise filtering devices for the spinmelt mass, for example in form of a wire mesh with a mesh size of from about 10 mesh to about 350 mesh, in particular from about 80 mesh to about 250 mesh, as well as the downstream spinneret. The additional filter devices may optionally consist of another metal mesh of the type described, which is mounted in the melt channel of the extruder and preferably interchangeable by means of a screen changer. The temperature of the spin composition must be chosen such that, on the one hand, a sufficient flowability of the spin composition is ensured and, on the other hand, the thermal load on the spin composition based on the polyketones according to the invention remains limited, so that the crosslinking and degradation reactions as well as the formation of gel in the spinning mass are kept within limits or can even be completely eliminated. In order to spin the melt into filaments, after the extrusion process, the melt can also be pressed by means of one or more spinning pumps, for example in the form of gear pumps, at a pressure between about 5 bar and about 80 bar, in particular between about 45 bar and about 55 bar, through the spinneret, which may have, for example, between 1 and about 750 spinning capillaries with one of the aforementioned diameters. A substantially vertical direction has been found to be the preferred flow direction of the melt, although not necessarily.

[0020] Once the filaments have been shaped by means of the spinning capillaries, their cooling can optionally be provided, which can take place at a distance downstream of the spinning capillaries between approximately 0.1 cm and approximately 20 cm and, for example, be carried out in a water bath at a temperature between 5 °C and about 95 °C, in particular between about 25 °C and about 30 °C, or in air or in another gas or mixture of gases at a temperature between about -100 °C and about 200 °C it can take place.

[0021] The resulting filament is then drawn from the spinning capillaries, for example, by means of a suitable set of guide rollers, with draw speeds conveniently set between about 1 m/min and about 200 m/min, in particular between about 1 m/min and about 120 m/min, preferably between about 5 m/min and about 50 m/min, for example, in the range of about 20 m/min. The withdrawal speed should preferably be selected so that the degree of stretching is greater than 1 compared to the speed of exit of the spinning mass from the nozzle, which results in a higher crystallinity of the filament with mechanical stability, resistance to Enhanced flex and flex recovery. Furthermore, the degree of stretching selected in this way improves the uniformity of the diameter of the filaments.

[0022] Immediately thereafter, one or more filament draws are carried out, for example, between different sets of guide rolls with a total draw factor conveniently between about 1:2 and about 1:15, in particular between about 1: 3 and about 1:15, preferably between about 1:4 and about 1:8, eg, in the range of about 1:4.8. In this context, it can be advantageously envisaged that one or each stretching step is followed by a relaxation or fixing step in which the stresses accumulated in the filament can be reduced by maintaining the corresponding tensile stress, which leads to a shrinkage factor. , in particular between about 1:0.7 and about 1:0.99, for example in the range of about 1:0.88. The individual stretching and relaxation steps can be carried out, for example, with the aid of hot air or steam at temperatures up to about 270 °C, in particular at temperatures up to about 250 °C, for example in the range from about 180 °C to about 220 °C.

[0023] Subsequently, lubricants, antistatic agents, bulking agents and the like can optionally be applied to the filaments to improve their processability, with a preferred method of application using a finishing roller at an adjustable speed, on which the filaments run. isolated or grouped.

[0024] The produced filaments may then be fed into a suitable storage form, eg coiled, to place the filament on a spool or spool, eg in round, elongated or other form for stocking. Optionally, the produced filament bundles can also be converted into a strand form. In any case, subsequent packaging can be carried out, for example by covering it with a hose or wrapping it with, for example, paper or plastic. Optionally, a final fixation of the filaments is carried out, for example in the form of heat setting at about 60 °C to about 220 °C in a quenching oven for about 5 minutes to about 30 hours or by autoclaving for from about 10 minutes to about 24 hours, preferably before packaging.

[0025] Finally, the produced filaments are cut to bristles in a cutting device.

[0026] Any crosslinking of the polymeric matrix of the filaments can be suppressed by a combination of adapted process parameters such as temperature, shear, flow ratio, spinning tension, degree of stretch, fixation and residence time.

[0027] In an advantageous embodiment, provision may be made for the polymer matrix of the plastic filament to contain at least approximately 80% by mass, for example at least approximately 85% by mass, in particular at least approximately 90% by mass. mass, for example, at least about 95% by mass, preferably about 100%, with respect to the entire polymeric matrix, of the at least one thermoplastic aliphatic polyketone that is composed of carbon monoxide and alkyl units.

[0028] In a further advantageous embodiment, the at least one thermoplastic aliphatic polyketone is a polyketone from the group of ethylene/CO copolymers, propylene/CO copolymers, ethylene/propylene/CO terpolymers and polymer blends thereof. The latter have the general structural formula,

OR OR

C-CH2-CH2- C-CH-CH2h

ⁱ i

R

in which R is a monovalent methyl group (CH ³ group). As already mentioned, the ethyl-CO units and the propyl-CO units do not necessarily have to be exclusively arranged alternately and the monovalent methyl group "R" of the above propyl unit can also be attached to the carbon atom adjacent to the above CH ² group (-[CO-CH ² -CHR-]n-), eg, in a mostly random distribution in the molecule.

[0029] In terms of process engineering, it can therefore be envisaged in this context that the at least one thermoplastic aliphatic polyketone according to step (a) is selected from the group of ethylene/CO copolymers, propylene/CO copolymers, ethylene/propylene/CO terpolymers and polymer blends thereof.

[0030] As also already mentioned, the invention offers in particular the possibility of a very thin design of the bristles, whereby the maximum diameter of the plastic filament can preferably be provided to be between approx. 0.01 mm and approx. 0.11 mm, in particular between about 0.01 mm and about 0.08 mm, preferably between about 0.01 mm and about 0.06 mm, for example between about 0.02 mm and about 0.06 mm.

[0031] In addition, in the case of a bristle according to the invention, it can advantageously be provided that the at least one thermoplastic aliphatic polyketone has at least one of the following material parameters:

- a melting temperature between about 180°C and about 250°C, in particular between 190 and 230°C, preferably between about 197°C and about 223°C;

- a melt flow index (MFI) between about 1 g/10 min and about 350 g/10 min, in particular between about 2 g/10 min and about 300 g/10 min, preferably between about 6 g/10 min and approximately 60 g/10 min, determined according to ASTM D1238 and ISO 1133 at a temperature of 240 °C and 21.6 N;

- a tensile strength at yield (tensile strength at yield) between approximately 35 MPa and approximately 70 MPa, in particular between approximately 43 MPa and approximately 63 MPa, determined according to the ASTM D638 standard at 23 °C; and

- a flexural modulus between about 450 MPa and about 2750 MPa, in particular between about 650 MPa and about 2350 MPa, preferably between about 650 MPa and about 2000 MPa, determined according to ASTM D790 at 23°C.

[0032] As already indicated, the polymeric matrix of the plastic filament based on thermoplastic polyketones, which are composed of carbon monoxide and alkyl units, can conveniently contain up to about 10% by mass, in particular up to about 5% by mass, preferably up to about 4% by mass, for example up to about 3% by mass or only up to about 2% by mass, respectively with respect to the entire polymeric matrix, of the at least one additive of the group of antioxidants and UV stabilizers, in which in many cases it may also be sufficient for the polymeric matrix to contain up to approximately 1% by mass of at least one of the aforementioned additives.

[0033] With regard to such additives, for the reasons mentioned above, it can preferably be provided that the at least one additive from the group of antioxidants and UV stabilizers comprises at least one additive from the group of sterically hindered phenols, HALS (high amine light stabilizer). impeded) and phosphites.

[0034] As antioxidants, which can be added to the polymeric matrix of the plastic filament, for example, with an advantageous proportion between about 0.1% by mass and about 5% by mass, preferably between about 0.5% by mass and about 3% by mass, according to the invention in particular sterically hindered phenols and/or HALS (hindered amine light stabilizers) and/or phosphites can be used, which can optionally be combined with co-stabilizers. Useful hindered phenol-based antioxidants include sterically hindered alkylated monophenols, eg, 2,6-di-tert-butyl-4-methylphenol or 2,6-di-tert-butyl-4-methoxyphenol, sterically hindered alkylthiomethylphenols, eg, 2,4-di-octylthiomethyl-6-tert-butylphenol, sterically hindered hydroxylated thiodiphenyl ethers, eg 2,2'-thio-bis(6-tert-butyl-4-methylphenol), 4,4'-thio-bis -(6-tert-butyl-3-methylphenol), 4,4'-thio-bis-(6-tert-butyl-2-methylphenol), 4,4'-thio-bis-(3,6-di- sec-amylphenol), 4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl)disulfide, sterically hindered alkylidenebisphenols, e.g. eg, 2,2'-methylene-bis-(6-tert-butyl-4-methylphenol, sterically hindered benzylphenols, eg, 3,5,3',5'-tetra-tert-butyl-4,4'- dihydroxydibenzylether, sterically hindered hydroxybenzylated malonates, eg dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hydroxy-benzyl)-malonate or bis-(1,2,2,6,6 -pentamethyl-4-piperidyl)-[[3,5-bis-(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-2-butylmalonate, sterically hindered hydroxybenzylaromatics, 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-hydroxybenzyl)-2 ,3,5,6-tetramethylbenzene, 2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-phenol, sterically hindered triazine phenolic compounds, eg 2,4-bis -octylmercapto-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2,4-bis-[[4-(2-ethyl-hexyloxy))-2-hydroxy] -phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine or 2-(4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazin-2-yl-5 -(3-((2-ethylhexyl)oxy)-2-hydroxypropoxy-phenol, benzylphosphone sterically hindered phenolic compounds, for example, dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate, N-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamic acid esters, l3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with monohydric or polyhydric alcohols, esters of l3-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with monohydric or polyhydric alcohols , l3-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid esters with monohydric or polyhydric alcohols, 3,5-di-tert-butyl-4-hydroxyphenylacetic acid esters with monohydric or polyhydric alcohols, l3 acid amides -(3,5-di-tert-butyl-4-hydroxyphenyl)propionic, such as N,N'-bis-(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)-hexamethylenediamine, N,N '-bis-(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)-trimethylenediamine or N,N'-bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine. Other examples of phenols of the type mentioned above include 3,9-bis-[2,4-bis-(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetra-oxa-3,9- diphosphaspiro[5.5]undecane, 3,9-bis-[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10 -tetraoxaspiro[5.5]undecane, p-tert-butylphenolformaldehyde, 13-diketones from the condensation of acetophenones and an ester of octadecanoic acid, bis[2-(tert-butyl-6-[[3-tert-butyl-2-hydroxy -5-methylphenyl]methyl]-4-methyl-phenyl]-1,4-benzenedicarboxylate and 1,2-bis[3,3-bis-(3-tert-butyl-4-hydroxyphenyl)butanat]ethylene Advantageous co-stabilizers include, for example organic phosphites and/or organic phosphonites, for example, 5-butyl-5-ethyl-2-(2,4,6-tris-tert-butyl-phenoxy)-1,3-dioxa-2-phosphorinane, diethylphosphonoacetate ethyl or 2,2'-ethylidene-bis-(4,6-di-tert-butylphenyl)fluorophosphonite, which are co-stabilizers of antioxidants known per se.

[0035] Examples of preferred UV stabilizers include UV-absorbing compounds such as benzophenones, for example, 4-tert-butyl-2-(5-tert-butyl-2-oxo-3H-benzofuran-3-yl)phenyl- 3,5-di-tert-butyl-4-hydroxybenzoate and benzotriazoles, eg 2(2'-hydroxy-5'-methylphenyl)benzotriazole, 7,9-alkyl-3-[3-(2H-benzotriazole-2 -yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]propionate, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy)phenol or ester of 1,3,5-tris(2-hydroxyethyl)-S-triazine-2,4,6-(1H,3H,5H) 3,5-di-tert-butyl-4-hydroxy-3-phenylpropionic acid trione, triazines, in particular hydroxyphenyltriazines, eg 2,4-bis-[[4-(2-ethyl-hexyloxy)-2-hydroxy]-phenyl]-6-(4-methoxyphenyl)-1,3,5 -triazine or 2-(4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazin-2-yl-5-(3-((2-ethylhexyl)oxy)-2-hydroxypropoxyphenol, as well as compounds of the HALS ("hindered amine light stabilizer") type, for example, bis-(2,2,6,6-tetramethyl-4-piperidinyl)-1,10-decanedioic acid, N,N'-propan- 1,3-diyl-bis-(3,5-di-tert-butyl -4-hydroxy-3-phenylpropionamide) or the like.

[0036] In addition, with a bristle according to the invention, it can of course be provided that the polymeric matrix of the plastic filament contains at least one other from the group of pigments and dyes, fillers, mattifying agents, reinforcing agents, crystallization accelerators, lubricants and antistatic agents, which are in particular physiologically innocuous and their proportion is based on the proportions usually added, which depend mainly on the type of additive in question. In terms of process engineering, it can be envisaged in this context that the respective desired amount of at least one other additive of the type mentioned above is added to the at least one thermoplastic aliphatic polyketone according to step (a) or that a master batch already contains the respective additive. The same applies, of course, to the additives from the group of antioxidants and UV stabilizers which are mandatory according to the invention.

[0037] For the coloring of the plastic filament according to the invention, dyes based on inorganic pigments or organic dyes can preferably be used, which, for example, can be added, for example, in the form of a master batch with a starting material. suitable support during extrusion (step (b) of the process according to the invention). 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.

[0038] Examples of preferred fillers include carbonates, such as, for example, chalk or dolomite, silicates, such as, for example, talc, mica, kaolin, or sulfates, such as, for example, barite, or oxides and hydroxides, such as such as, for example, quartz flours, crystalline silica, aluminum or magnesium hydroxides or oxides of magnesium, zinc or calcium.

[0039] An example of a preferred matting agent is titanium dioxide; examples of preferred crystallization accelerators include carboxylic acid esters.

[0040] Examples of preferred lubricants include polyolefin waxes, fatty acids or their salts, alcohols fatty acids, fatty acid esters, silicones, polysiloxanes and, in particular, PMSQ, as described in EP 2933361 A1.

[0041] Examples of preferred antistatic agents include carbon black, graphite, graphene, carbon nanotubes (CNTs), or metal particles.

[0042] Examples of preferred processing aids include longer chain carboxylic acids or waxes including their aliphatic and aromatic salts, esters or ethers.

[0043] As already indicated, in combinations of the thermoplastic aliphatic polyketones with other selected thermoplastic polymers, the individual polymeric components can complement each other synergistically, whereby the plastic filaments can have excellent mechanical properties, such as high modulus of elasticity, low creep, low tendency to sag, etc., and due to the thermoplastic aliphatic polyketone, in particular, high bending stiffness and higher abrasion resistance to be able to make the plastic filament very thin. According to a further development of a bristle according to the invention, it can therefore be envisaged that the polymer matrix of the plastic filament contains up to about 30% by mass, for example up to about 25% by mass, in particular up to 20% by mass, eg up to about 15% by mass, preferably up to about 10% by mass, eg up to about 5% by mass, based on the entire polymer matrix, of at least one thermoplastic polymer additional.

[0044] The at least one additional thermoplastic polymer can preferably be selected from the group of polyolefins, polyesters, polyamides, polyoxymethylenes, polyurethanes, polyphenylenesulfides, polyphenylenesulfones, polyethersulfones, polyphenylene ethers, polyphenylketones, polyphenylene ether ketones, polyetherimides, polyetherether ketones, thermoplastic elastomers, in particular in the form of thermoplastic polyurethanes, polyesters and/or polyamides, and liquid crystalline polymers, it being understood that various representatives of the aforementioned polymers may also be used. These other polymers are mainly polymers known per se that are already used in the state of the art for the production of filaments.

[0045] Examples of polyolefins include homopolymers or copolymers derived from ethylene and/or propylene, optionally in combination with other ethylenically unsaturated aliphatic hydrocarbons, such as α-olefins having from four to eight carbon atoms. Polyethylene and polypropylene can be present at different densities and crystallinities.

[0046] Examples of polyesters include thermoplastic polymers that are derived from aliphatic, cycloaliphatic and/or aromatic dicarboxylic acids or their polyester-forming derivatives, such as, for example, alkyl esters of aliphatic, cycloaliphatic and/or aromatic dihydric alcohols , such as, for example, ethylene glycol, 1,3-propylene glycol and/or butylene glycol. Other examples of polyesters include thermoplastic elastomeric polyesters (TPE-C), such as, for example, polyesters containing repeating butylene terephthalate framework units and repeating polybutylene glycol terephthalate framework units. Preferably, aromatic-aliphatic polyester homopolymers or copolymers can be used, such as, for example, polybutylene terephthalate homopolymers or copolymers containing butylene terephthalate units. Therefore, such preferred polymers are derived from butylene glycol and optionally other alcohols and from terephthalic acid or its polyester-forming derivatives, such as esters or chlorides of terephthalic acid. In addition to or instead of 1,4-butanediol, such polyesters may contain structural units derived from other suitable dihydric alcohols, typical representatives of which include aliphatic and/or cycloaliphatic diols, for example 1,2-ethanediol, 1, 3-propanediol, 1,2-cyclohexanedimethanol or mixtures thereof. In addition to or instead of terephthalic acid or its polyester-forming derivatives, such polyesters may contain structural units derived from other suitable dicarboxylic acids or their polyester-forming derivatives, typical representatives of which include aromatic and/or aliphatic dicarboxylic acids and /or cycloaliphatic, for example naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, sebacic acid or mixtures thereof. Consequently, it can also be made of plastic filaments containing other polyesters, such as, for example, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polyethylene naphthalate homopolymer or copolymers containing ethylene naphthalate units. The thermoplastic copolyester components preferably include the aforementioned diols and dicarboxylic acids, or correspondingly structured polyester-forming derivatives. Preference is given to the use of polyesters whose solution viscosities (IV values) are at least about 0.60 dl/g, in particular between about 0.80 dl/g and about 1.05 dl/g, preferably between about 0. 80 dl/g and about 0.95 dl/g, respectively measured at 25 °C in dichloroacetic acid (DCE)).

[0047] Examples of polyamides include thermoplastic polymers that are derived from aliphatic, cycloaliphatic and/or aromatic dicarboxylic acids or their polyamide-forming derivatives, such as, for example, their salts, and of divalent aliphatic, cycloaliphatic and/or aromatic amines, such as, for example, hexamethylenediamine. Other examples of polyamides include thermoplastic-elastomeric polyamides (TPE-A), for example polyamides containing repeating hexamethylene terephthalamide moieties and containing repeating polyethylene glycol terephthalamide moieties. The polyamides used preferably include, in particular, partially crystalline aliphatic polyamides, which can be produced from aliphatic diamines and aliphatic dicarboxylic acids and/or cycloaliphatic lactams with at least 5 ring members or corresponding amino acids. Possible starting reagents are aliphatic dicarboxylic acids, preferably adipic acid, 2,2,4- and 2,4,4-trimethyladipic acid, azelaic acid and/or sebacic acid, aliphatic diamines, preferably 1,4-tetramethylenediamine, 1, 6-hexamethylenediamine, 1,9-nonandiamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, isomeric diaminodicyclohexylmethane, diaminodicyclohexylpropane, bisaminomethylcyclohexane, aminocarboxylic acids, preferably aminocaproic acid or the corresponding lactams. Copolyamides made from several of the aforementioned monomers are included. Caprolactams, in particular s-caprolactam, can be used with particular preference. The aliphatic homopolyamides or copolyamides used according to the invention are also preferably 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. In addition, the polyesters and polyamides used according to the invention can also be derived from hydroxycarboxylic acids or aminocarboxylic acids.

[0048] Examples of polyoxymethylenes include homopolymers or copolymers containing repeating structural units of the formula -CH2-O-.

[0049] Examples of polyurethanes include homopolymers or copolymers which are derived from aromatic or (cyclo)aliphatic diisocyanates and from (cyclo)aliphatic or aromatic diols. Polyurethanes contain, for example, repeating structural units of the formula -C ⁶ H ⁴ -NH-CO-OC ² H ⁴ -O-CONH-. Other examples of polyurethanes include thermoplastic-elastomeric polyurethanes (TPE-U).

[0050] Examples of polyphenylene sulfides include poly-p-phenylene sulfides, eg homopolymers or copolymers containing repeating structural units of -para-C6H4-S-. Examples of polyphenylenesulfones include poly-p-phenylenesulfones, for example homopolymers or copolymers, containing repeating structural units of -para-C6H4-SOx-, where x is a number between 1 and 2.

[0051] Examples of polyphenylene ethers include poly-p-phenylene ethers, eg homopolymers or copolymers, containing repeating structural units of -para-C6H4-O-.

[0052] Examples of polyphenylketones include poly-p-phenylketones, eg homopolymers or copolymers, containing repeating structural units of -para-C6H4-CO-.

[0053] Examples of polyphenylene ether ketones include poly-p-phenylene ether ketones, eg copolymers containing repeating structural units of -para-C6H4-CO- and repeating structural units of -para-C6H4-O-.

[0054] Examples of liquid crystalline polymers include liquid crystalline aromatic polyesters, eg homopolymers or copolymers, containing repeating structural units derived from parahydroxybenzoic acid.

[0055] According to an embodiment of a bristle made of a plastic filament, whose polymeric matrix contains at least one additional thermoplastic polymer, such as one or more polymers of the type mentioned above, in addition to the thermoplastic aliphatic polyketone, which is composed of units of carbon and alkyl monoxide, it can be envisaged that the polymeric matrix of the plastic filament is formed at least partially from a polymeric mixture of at least one thermoplastic polyketone and at least one additional thermoplastic polymer.

[0056] In terms of process engineering, it can therefore be envisaged in this context that up to about 30% by mass, in particular up to about 20%, is added to the at least one thermoplastic aliphatic polyketone according to step (a). % by mass, preferably up to about 10% by mass, of at least one additional thermoplastic polymer, in particular from the group of polyolefins, polyesters, polyamides, polyoxymethylenes, polyurethanes, polyphenylenesulfides, polyphenylenesulfones, polyethersulfones, polyphenylene ethers, polyphenylketones, polyphenylene etherketones, polyetherimides , polyetheretherketones, thermoplastic elastomers, in particular in the form of thermoplastic polyurethanes, polyesters and/or polyamides, and liquid crystalline polymers.

[0057] According to another embodiment of a bristle made of a plastic filament, whose polymeric matrix, in addition of the thermoplastic aliphatic polyketone, which is composed of carbon monoxide and alkyl units, contains at least one other thermoplastic polymer, such as one or more polymers of the type mentioned above, it can alternatively or additionally be provided that the plastic filament has a cross section in which the at least one thermoplastic polyketone and the at least one other thermoplastic polymer are spatially separated, but are arranged coherently, in particular in a side-by-side and/or core-shell structure.

[0058] In terms of process engineering, therefore, it can be envisaged in this context that the procedure comprises the following additional steps:

(a2) Providing an additional spinning mass containing at least one other thermoplastic polymer, in particular from the group of polyolefins, polyesters, polyamides, polyoxymethylenes, polyurethanes, polyphenylenesulfides, polyphenylenesulfones, polyethersulfones, polyphenylene ethers, polyphenylketones, polyphenylene etherketones, polyetherimides, polyetheretherketones, thermoplastic elastomers , in particular in the form of thermoplastic polyurethanes, polyesters and/or polyamides, and liquid crystalline polymers; and

(b2) Extruding both the spin mass according to step (a) and the additional spin mass according to step (a2) in an extruder, each through at least one die with one or more spin capillaries, so that each spinning capillary is traversed by both the spinning mass according to step (a) and the additional spinning mass according to step (a2).

Such coextrusion of different thermoplastic polymers for the production of filaments is known per se in the state of the art.

[0059] It should be noted at this point that the cross-sectional shape of the plastic filaments according to the invention does not necessarily have to be round (circular), but arbitrary. Then it can be, for example, regular or irregular cross sections, point symmetric or axially symmetric cross sections, for example round, oval or n-angular cross sections, where n is greater than or equal to 3, trilobe or multilobe cross sections. and the like.

[0060] In addition, to improve the cleaning effect of the bristles according to the invention, it can be provided that

- its outer surface is provided with stamping; me

- It is designed corrugated in the longitudinal direction.

For example, a corrugation with any amplitude and/or wavelength can be pressed into the plastic filament by means of a stamping mechanism, for example, another stamping can be applied, which is conveniently done before cutting the filaments according to step (f).

[0061] If desired, the bristle according to the invention can also be mechanically and/or chemically tapered.

[0062] Other features and advantages of the invention will become apparent from the following description of an embodiment with reference to the drawing. The single figure shows

a detailed schematic view of an embodiment of a toothbrush with fine bristles formed from sections of a plastic filament based on thermoplastic aliphatic polyketones.

[0063] The toothbrush shown in the drawing comprises a bristle holder 1 and a handle 2 (shown broken), which in the present example of embodiment are designed in one piece and, for example, are made of one or more conventional plastics, in particular thermoplastics. On the bristle carrier 1 a plurality of bristles 3 are fixed, which, for example, can be fixed on the bristle carrier 1 by means of extrusion coating and in the present case are arranged in a plurality of bristle bundles 4, for example arranged in rows and columns in an approximately matrix fashion. Each of the bristles 3 consists of a section of a plastic filament based on thermoplastic aliphatic polyketones, as described in detail above. The diameter of the bristles is advantageously less than about 0.08mm, for example, in the range of about 0.02mm to about 0.05mm, so that they can easily penetrate interdental spaces during the intended use of the brush. of teeth and a very high number of bristles, for example between about 5000 and about 7000, such as for example about 6000, have room in the bristle carrier to ensure a very efficient cleaning effect.

Claims (15)

1. Bristle (3), which is formed from a section of a plastic filament, in which the polymeric matrix of the plastic filament contains at least 70% by mass, with respect to the complete polymeric matrix, of at least least one thermoplastic aliphatic polyketone, which is composed of carbon monoxide and alkyl units, in which the polymeric matrix of the plastic filament also contains at least one additive from the group of antioxidants and UV stabilizers, and in which the diameter maximum of the plastic filament is between 0.01 mm and 0.13 mm. 2. Bristle according to claim 1, characterized in that the polymeric matrix of the plastic filament contains at least 80% by mass, in particular at least 90% by mass, preferably approximately 100%, with respect to the complete polymeric matrix, of at least one thermoplastic aliphatic polyketone, which is composed of carbon monoxide and alkyl units. 3. Bristle according to claim 1 or 2, characterized in that the at least one thermoplastic aliphatic polyketone is a polyketone from the group of ethylene/CO copolymers, propylene/CO copolymers, ethylene/propylene/CO terpolymers and polymer blends of the themselves. 4. Bristle according to any of claims 1 to 3, characterized in that the maximum diameter of the plastic filament is between 0.01 mm and 0.11 mm, in particular between 0.01 mm and 0.08 mm, preferably between 0 .01mm and 0.06mm. 5. Bristle according to any of claims 1 to 4, characterized in that the at least one thermoplastic aliphatic polyketone has at least one of the following material parameters: - a melting temperature between 180 °C and 250 °C, in particular between 190 °C and 230 °C; - a melt flow index between 1 and 350 g/10 min, in particular between 2 and 300 g/10 min, determined according to the standards ASTM D1238 and ISO 1133 at 240 °C; - a creep tensile strength between 35 MPa and 70 MPa, in particular between 43 MPa and 63 MPa, determined according to the ASTM D638 standard at 23 °C; and - a flexural modulus between 450 MPa and 2750 MPa, in particular between 650 MPa and 2000 MPa, determined according to the ASTM D790 standard at 23 °C. 6. Bristle according to any of claims 1 to 5, characterized in that the polymeric matrix of the plastic filament - contains up to 10% by mass, in particular up to 5% by mass, with respect to the complete polymeric matrix, of at least one additive from the group of antioxidants and UV stabilizers, comprising the at least one additive from the group of antioxidants and UV stabilizers, in particular at least one additive from the group of sterically hindered phenols, hAlS (hindered amine light stabilizer) and phosphites; and/or - contains at least one other additive from the group of pigments and dyes, fillers, matting agents, reinforcing agents, crystallization accelerators, lubricants and antistatic agents. 7. Bristle according to any of claims 1 to 6, characterized in that the polymeric matrix of the plastic filament contains up to 30% by mass, in particular up to 20% by mass, preferably up to 10% by mass, with respect to the complete polymeric matrix, of at least one other thermoplastic polymer, in which the at least one other thermoplastic polymer is selected in particular from the group of polyolefins, polyesters, polyamides, polyoxymethylenes, polyurethanes, polyphenylene sulfides, polyphenylene sulfones, polyether sulfones, polyphenylene ethers, polyphenylketones, polyphenylene ether ketones, polyetherimides , polyetheretherketones, thermoplastic elastomers, in particular in the form of thermoplastic polyurethanes, polyesters and/or polyamides, and liquid crystalline polymers. Bristle according to claim 7, characterized in that the polymeric matrix of the plastic filament is formed, at least partially, from a polymeric mixture of the at least one thermoplastic polyketone and the at least one other thermoplastic polymer. Bristle according to claim 7 or 8, characterized in that the plastic filament has a cross-section in which the at least one thermoplastic polyketone and the at least one other thermoplastic polymer are arranged spatially separated, but adjacent to each other, in particular in a side-over-side and/or core-shell structure. 10. Bristle according to any of claims 1 to 9, characterized in that - its outer surface is provided with stamping; me - it is designed corrugated in the longitudinal direction; me - is mechanically and/or chemically tapered. 11. Brush with at least one bristle holder (1) and a plurality of bristles (3) attached to the bristle holder (1), in particular in the form of a toothbrush, characterized in that at least some of the bristles (3) are bristles according to any of claims 1 to 10. 12. Process for producing a bristle (3) according to any of claims 1 to 10, comprising the following steps: (a) Providing a spinning mass containing at least 70% by mass of at least one thermoplastic aliphatic polyketone, which is composed of carbon monoxide and alkyl units, and in which the at least one thermoplastic aliphatic polyketone, it contains in particular up to 10% by mass of at least one additive from the group of antioxidants and UV stabilizers; (b) Extruding the spinning mass according to step (a) through at least one spinneret with one or more spinning capillaries with a diameter of maximum 1.0 mm, in particular maximum 0.8 mm , preferably a maximum of 0.4 mm, in which the temperature of the spinning mass on the exit side of the spinning capillary(s) is set in the range from 190 °C to 300 °C, in particular in in the range of 200°C to 270°C, preferably in the range of 220°C to 260°C; (c) Extracting the formed filament at an extraction speed in the range of 1 to 200 m/min, in particular 5 to 50 m/min, preferably with a selection of the ratio between the extraction speed and the output speed of the spinning mass of the spinning capillary of more than 1; (d) drawing the formed filament once or multiple times; (e) optionally winding the formed filament; and (f) Cutting the formed filament to size while retaining the bristles (3). 13. Method according to claim 12, characterized in that - the at least one thermoplastic aliphatic polyketone according to step (a) is selected from the group of ethylene/CO copolymers, propylene/CO copolymers, ethylene/propylene/CO terpolymers and polymer blends thereof; me - to the at least one thermoplastic aliphatic polyketone according to step (a) is added up to 30% by mass of at least one other thermoplastic polymer, in particular from the group of polyolefins, polyesters, polyamides, polyoxymethylenes, polyurethanes, polyphenylene sulfides, polyphenylene sulfones, polyethersulfones, polyphenylene ethers, polyphenylketones, polyphenylene etherketones, polyetherimides, polyetheretherketones, thermoplastic elastomers, preferably in the form of thermoplastic polyurethanes, polyesters and/or polyamides, and liquid crystalline polymers. 14. Process according to claim 12 or 13, characterized in that at least one other thermoplastic aliphatic polyketone according to step (a) is added at least one other additive from the group of pigments and dyes, fillers, mattifying agents, reinforcing agents, accelerators of crystallization, lubricants and antistatic agents. 15. Method according to any of claims 12 to 14, characterized by the following additional steps: (a2) Providing an additional spinning mass containing at least one other thermoplastic polymer, in particular from the group of polyolefins, polyesters, polyamides, polyoxymethylenes, polyurethanes, polyphenylenesulfides, polyphenylenesulfones, polyethersulfones, polyphenylene ethers, polyphenylketones, polyphenylene etherketones, polyetherimides, polyetheretherketones, thermoplastic elastomers , in particular in the form of thermoplastic polyurethanes, polyesters and/or polyamides, and liquid crystalline polymers; and (b2) Extruding both the spin mass according to step (a) and the additional spin mass according to step (a2) in an extruder, each through at least one die with one or more spin capillaries, of so that each spinning capillary is traversed by both the spinning mass according to step (a) and the additional spinning mass according to step (a2).