Polymer monofilament comprising ionomer with silicone oil-coated surface

Abstract

Provided is a polymer monofilament having improved lubrication properties. More specifically, on the basis of the existing silicone oil coated monofilament, an ionomer is added into a polyester and / or nylon material for the monofilament, so that the high polymer monofilament with further improved lubricating property can be obtained. The invention also provides a method for preparing the monofilament. The invention also relates to a brush wire prepared from the monofilament and a toothbrush prepared from the brush wire.

Description

Technical Field

[0001] This invention relates to polymeric monofilaments with improved lubrication properties. More specifically, this invention relates to polymeric monofilaments containing ionomers with a silicone oil-coated surface. The invention also relates to methods for preparing the monofilament material and its use in brush-like materials such as toothbrushes. Background Technology

[0002] Nylon and polyester are typical polymer materials used to manufacture toothbrush bristles. They can usually be processed into monofilaments through melt extrusion.

[0003] In the traditional brush bristle implantation process, the desired outcome is stable transport of the monofilament material on the implantation machine. To achieve this, various improvement methods have been developed to enhance the lubrication performance of the monofilaments, thereby enabling the brush bristle implantation process to proceed more smoothly.

[0004] One classic technique involves coating traditional polymer monofilaments with silicone oil, resulting in silicone-coated monofilaments. This post-processing of silicone oil coating typically improves the lubrication properties of the resulting monofilaments.

[0005] Although nylon or polyester monofilaments can improve lubrication by coating their surfaces with silicone oil during the later stages of spinning, both excessively high and low silicone oil content can lead to defects in actual production. For example, if too much silicone oil is applied, the monofilaments are prone to sticking together, making it difficult for them to be stably transferred on the machinery in downstream processing steps such as brush bristle implantation, resulting in defective products. Conversely, if too little silicone oil is applied, the monofilament surface becomes too dry, resulting in high friction and low combing efficiency during production, decreased monofilament quality, and a high defect rate.

[0006] People still hope to develop monofilament materials with further improved lubrication performance; even more so, they hope that this performance improvement is based on overcoming the shortcomings of existing technologies such as silicone oil coating technology.

[0007] Ionomers are polymers that contain ionic groups of carboxylate salts that are cations, including but not limited to at least one of alkali metals, alkaline earth metals, transition metals, and ammonium cations. Ionomer resins are generally considered to have, for example, excellent low-temperature impact toughness, and excellent wear and scratch resistance. According to manufacturers, ionomers can be used in (1) cosmetics: perfume bottle caps, cream and ointment containers, etc.; (2) consumer products: such as various handles, toys such as pet chews, ice buckets, flooring; (3) sports equipment: golf ball shells, surfboards, ski board surfaces, ski boots, ice skates, snow hockey helmets; shoe heel linings, cowboy protective vests, etc.

[0008] In the prior art, a typical application of ionomer materials is in the packaging industry because of their excellent heat-sealing and adhesive properties. A representative example of ionomers is the ionomer of ethylene / (meth)acrylate copolymers neutralized with sodium or zinc. For instance, CN 101292793A discloses a high-modulus ionomer for packaging.

[0009] The use of ionomer compositions as laminated sheets for protection against threats is known in the art. For example, US 5759698 discloses glass laminated sheets derived from ionomer resins, wherein the ionomers are subjected to overheat curing with organic peroxides and silane reagents.

[0010] The use of ionomer compositions as solar electromagnetic encapsulation films or sheets is also known in the field, see, for example, US 5476553, etc.

[0011] In addition, JP 2002348732 A discloses a polyamide monofilament containing an ionomer and a method for preparing the same, specifically disclosing the following (see paragraphs

[0021] -

[0037] of the specification): The polyamide monofilament can be manufactured as follows: without using pre-mixed granules, a specified amount of polyamide granules is pre-metered and mixed separately with at least one granule or powder selected from ionomer resin, styrene-2-isopropenyl-2-oxazoline random copolymer, or styrene-acrylonitrile-2-isopropenyl-2-oxazoline random copolymer, and then melt-mixed at a temperature 20-60°C higher than the melting point of the polyamide used, and then spun directly from a spinneret. It is claimed that "although polyamide monofilaments are traditionally used in various applications due to their superior abrasion resistance compared to polyester monofilaments, the blending of the polyamide granules with at least one granule or powder selected from three components is to improve the abrasion resistance of the composite monofilament so that the composite nylon monofilament can be better used, for example, as lawn mowing thread."

[0012] The inventors have surprisingly discovered that by adding an ionomer to a silicone oil-coated nylon and / or polyester-based monofilament material, the resulting composite monofilament material exhibits further improved lubrication properties, allowing for better use in the bristle-forming process of brush manufacturing. This improves combing efficiency during production, further enhances monofilament quality, and reduces the defect rate. Preferably, the ionomer is an ionomer resin of ethylene and a copolymer of C3-C8 olefinic unsaturated monocarboxylic acids, and at least a portion of the carboxylic acid is neutralized by metal ions. Summary of the Invention

[0013] In one aspect of the invention, a polymeric monofilament comprising an ionomer is provided on a surface coated with silicone oil, wherein the ionomer is an ionomer resin of a copolymer of ethylene and C3-C8 olefinic unsaturated monocarboxylic acids, and at least a portion of the carboxylic acid is neutralized by metal ions; and wherein the silicone oil is preferably a food-grade silicone oil selected from methyl silicone oil, amino silicone oil, phenyl silicone oil, etc.

[0014] In another aspect, the present invention also provides a method for preparing polymer material monofilaments as described above, comprising the following steps:

[0015] 1) The base resin nylon and / or polyester is mixed with the ionomer and other optional additives in a mixer to obtain a premix;

[0016] 2) The premixed material obtained in step 1) is fed into a screw extruder for melt extrusion; after the melt is extruded and sprayed out by the spinneret, it is initially cooled, and then undergoes post-processing steps such as hot stretching and shaping to obtain melt-extruded monofilaments;

[0017] 3) Pass the melt-extruded monofilament obtained in step 2) through a silicone oil emulsion, coat it with silicone oil, and then further wind the product to obtain a monofilament of polymer material containing ionomers on the silicone oil coated surface.

[0018] In yet another aspect of the invention, another method for preparing polymer monofilaments is provided, comprising the following steps:

[0019] 1) The base resin nylon and / or polyester, along with the ionomer and other optional additives, are directly fed into a screw extruder for melt extrusion. After the melt is extruded and ejected from the spinneret, it is initially cooled and then undergoes post-processing steps such as hot stretching and setting to obtain melt-extruded monofilaments.

[0020] 2) Pass the melt-extruded monofilament from step 1) through a silicone oil emulsion, coat it with silicone oil, and then further wind the product to obtain a polymer material monofilament containing ionomers on the silicone oil-coated surface.

[0021] In a further aspect of the invention, the invention provides a method for improving the lubrication performance of polymer monofilaments coated with silicone oil, the method comprising adding an ionomer to the polymer monofilaments, wherein the silicone oil is preferably food-grade silicone oil selected from methyl silicone oil, amino silicone oil, phenyl silicone oil, etc.; and wherein the ionomer is an ionomer resin of ethylene and a copolymer of C3-C8 olefinic unsaturated monocarboxylic acids, and at least a portion of the carboxylic acid is neutralized by metal ions.

[0022] Compared to traditional nylon or polyester monofilaments coated only with silicone oil, this polymer material monofilament coated with silicone oil and containing ionomers has excellent lubrication properties, is easy to comb, and can be more stably transported by the tufting equipment in subsequent processes. Invention Details

[0024] Except as provided in the examples or otherwise expressly indicated, all figures in this specification representing the amount of material or reaction conditions, the physical properties of the material and / or its use may optionally be understood to be modified by the word “about”.

[0025] Unless otherwise stated, all quantities are by weight of the composition.

[0026] It should be noted that when specifying any numerical range, any particular upper limit value can be associated with any particular lower limit value.

[0027] To avoid ambiguity, the word "contains" is intended to mean "including," but not necessarily "composed of" or "consisting of." In other words, the steps or options listed do not need to be exhaustive.

[0028] The disclosure of the present invention found herein is intended to cover all embodiments found to be multiplely dependent on each other in the claims, regardless of the fact that the claims may not be found to be multiplely dependent or redundant.

[0029] Where a feature is disclosed with respect to a particular aspect of the invention (e.g., the composition of the invention), such disclosure is also considered applicable to any other aspect of the invention (e.g., the method of the invention) with necessary modifications.

[0030] polyamide resin

[0031] One type of base resin for the monofilament material that can be used in this invention is nylon, or polyamide PA.

[0032] The nylon used in this invention has a linear backbone and can be produced by reacting a dicarboxylic acid with a diamine to form a linear condensed nylon. Non-limiting examples of dicarboxylic acids include C6 to C12 aliphatic dicarboxylic acids such as adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid, and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Non-limiting examples of diamines include linear aliphatic or alicyclic diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, isophoronediamine, and 1,4-cyclohexanebis(methylamine) and decanediamine. Non-limiting examples of diamines may also include linear aromatic diamines such as phenylenediamine and benzidine. In the art, for example, the resulting polyamides or nylons are named according to the number of carbon atoms in the dicarboxylic acid and diamine monomer molecules. For example, the polyamide obtained by polymerizing adipic acid with hexamethylenediamine is named polyamide 66, nylon 66, or PA66, and so on; this knowledge is well known to those skilled in the art.

[0033] The nylon used in this invention can also be produced by ring-opening polymerization of an amino-containing carboxylic acid compound or its lactam. Non-limiting examples of amino-containing carboxylic acid compounds include C6 to C12 aliphatic terminal amino carboxylic acid compounds such as 6-aminohexanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. In the art, for example, the polyamide is named according to the total number of carbon atoms of the lactam; typical lactams derived from amino-containing carboxylic acid compounds having 6, 11, or 12 carbon atoms are named Nylon 6, Nylon 11, and Nylon 12, and so on; this knowledge is well known to those skilled in the art.

[0034] In embodiments of the present invention, the nylon that can be used is selected from PA612, PA610, PA512, PA510, PA6, PA66, PA46, PA1010, PA11, PA12 or a combination thereof.

[0035] In a particularly preferred embodiment of the invention, the nylon is selected from PA612. An exemplary example of PA612 is nylon PA612 purchased from Celanese Corporation.

[0036] Polyester resin

[0037] Another type of base resin for monofilament materials that can be used in this invention is polyester.

[0038] The polyester used in this invention has a linear backbone and can be produced by reacting a dicarboxylic acid with a diol to form a linear condensation polyester. Non-limiting examples of dicarboxylic acids include C6 to C12 aliphatic dicarboxylic acids such as adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid, as well as aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid.

[0039] Non-limiting examples of polyesters include the reaction product of terephthalic acid and ethylene glycol, namely polyethylene terephthalate (PET), and similarly, polybutylene terephthalate (PBT), polypropylene terephthalate (PTT), and polybutylene succinate (PBS). Copolyesters include, for example, polybutylene adipate / terephthalate (PBAT), polybutylene sebacic acid / butylene adipate (PBSA), and copolyhydroxyalkanoates.

[0040] In a preferred embodiment of the present invention, the polyester is selected from PET, PBT, PTT, PBS, or mixtures thereof. In a particularly preferred embodiment of the present invention, the polyester is polybutylene terephthalate (PBT).

[0041] Exemplary representatives of the PBT include PBT B2520 purchased from BASF, PBT L2100 purchased from Sinopec Yizheng Chemical Fiber, PBT 1200 211D / 211M purchased from Changchun Chemical, and spinning-grade PBT purchased from Hengli Chemical Fiber.

[0042] Isopolymer

[0043] As used herein, the term "ionomer" refers to a polymer containing an ionic group that is a carboxylate, including but not limited to at least one of alkali metals, alkaline earth metals, transition metals, and ammonium cations.

[0044] As used herein, the term "ionomer" refers to a polymer comprising an ionic group of a carboxylate as a cation, including but not limited to one or more of alkali metals, alkaline earth metals, transition metals, and ammonium cations. As defined herein, such polymers are typically prepared by partially or completely neutralizing the carboxylate groups of a precursor or "parent" polymer, for example, by reacting it with a base, wherein the precursor or "parent" polymer is an acidic copolymer. Ionomers are typically named by the cation used for carboxylate neutralization. For example, neutralizing at least a portion of the carboxylate groups of a copolymer of ethylene and methacrylic acid using sodium hydroxide produces a sodium ionomer (or a sodium-neutralized ionomer) comprising sodium carboxylate.

[0045] In a broader sense, the ionomers described in this invention are derivatives of ionized portions of a parent acid copolymer (alternatively named precursor acid copolymers) comprising a copolymer of α-olefin units and α,β-olefinically unsaturated carboxylic acid units. Examples of suitable ionomers include, for instance, those described in U.S. Patent 7,763,360 and U.S. Patent Application Publication 2010 / 0112253.

[0046] In one embodiment of the invention, the α-olefin unit of the precursor acid copolymer has 2 to 10 carbon atoms, and the α,β-olefinically unsaturated carboxylic acid unit has 3 to 8 carbon atoms. The amount of copolymerized α-olefin is complementary to the amount of α,β-olefinically unsaturated carboxylic acid and, when present, the amount of one or more other comonomers, such that the sum of the weight percentages of the comonomers in the precursor acid copolymer is 100% by weight. In a representative, non-limiting embodiment, the precursor acid copolymer comprises about 15 to about 30% by weight, or about 18 to about 25% by weight, or about 19 to about 23% by weight of copolymerized α,β-olefinically unsaturated carboxylic acid.

[0047] Suitable α-olefin comonomer units include, but are not limited to, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 3-methyl-1-butene, 4-methyl-1-pentene, and mixtures of two or more thereof. In one possible embodiment, the α-olefin is ethylene.

[0048] Suitable α,β-olefinic unsaturated carboxylic acid comonomer units include, but are not limited to, acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, monomethylmaleic acid, and mixtures of two or more thereof.

[0049] In possible implementations, the α,β-olefinic unsaturated carboxylic acid is selected from acrylic acid, methacrylic acid, and mixtures thereof.

[0050] In one embodiment of the invention, the α,β-olefinically unsaturated carboxylic acid is methacrylic acid. It is noteworthy that the acid copolymer is essentially composed of copolymerized ethylene units and α,β-olefinically unsaturated carboxylic acid units; that is, a dimer of ethylene and α,β-olefinically unsaturated carboxylic acid.

[0051] In a preferred embodiment of the invention, the ionomer is an ionomer resin of a copolymer of ethylene and C3-C8 α,β-olefinic unsaturated monocarboxylic acids, and at least a portion of the carboxylic acid is neutralized by metal ions.

[0052] In a particularly preferred embodiment of the invention, the α,β-olefinic unsaturation is methacrylic acid or acrylic acid. Note that, in the context of this application, the expression (meth)acrylic acid means acrylic acid and / or methacrylic acid. In other words, in the most preferred embodiment of the invention, the ionomer of the invention is an ethylene-methacrylic acid dimer, an ethylene-acrylic acid dimer, or a mixture thereof.

[0053] In a preferred embodiment of the invention, the acid portion of the ionomer resin is neutralized by metal ions selected from sodium, zinc, lithium, magnesium, calcium, and any mixture thereof.

[0054] In a particularly preferred embodiment of the invention, the acid portion of the ionomer resin is neutralized by metal ions selected from sodium, zinc, and any mixture thereof.

[0055] Ionicomers that can be used in this invention include commercially available ionomers, such as Iotek from Exxon. TM (Ethylene-acrylic acid); Amplify, sourced from Dow Chemical. TM (ethylene-acrylic acid copolymer); and from Dow Chemical Company (Ethylene–methacrylic acid copolymer).

[0056] In a particularly preferred embodiment of the invention, the ionomer is selected from Dow Chemical Company. A series of products, specific exemplary examples include 8920, 9910, etc.; these are the sodium and zinc salts of ethylene-methacrylic acid copolymer resin, respectively.

[0057] silicone oil

[0058] In embodiments of the present invention, considering the desired application areas of the toothbrush bristles of the target product, the applicable silicone oils mainly include food-grade silicone oils.

[0059] Silicone oil typically refers to linear polysiloxane products that remain liquid at room temperature, and usually has the following structural formula:

[0060]

[0061] Wherein, R represents alkyl or aryl; R' represents alkyl, aryl, hydrogen, carbon functional group, amino-containing alkyl, and polyether chain, etc.; X represents alkyl, aryl, alkenyl, hydrogen, hydroxyl, alkoxy, acetoxy, chlorine, carbon functional group, and polyether chain, etc.; n, m = 0, 1, 2, 3, etc.

[0062] According to the present invention, in the structure shown above, when all organic groups are methyl, the silicone oil is called methyl silicone oil. Other organic groups can also be used to replace some of the methyl groups to improve certain properties of the silicone oil and make it suitable for various applications. Common other groups include hydrogen, ethyl, phenyl, chlorophenyl, trifluoropropyl, etc.

[0063] In embodiments of the invention, the silicone oil can typically be used in the form of an emulsion; that is, a silicone oil emulsion can be used in the invention. In a preferred embodiment of the invention, the silicone oil emulsion is typically diluted with water and then coated onto the surface of the monofilament.

[0064] In the embodiments of the present invention, exemplary examples of silicone oils that can be used in the present invention include: DOWSIL from DowInc. TM SH 7024, DOWSIL TM 8024, DOWSIL TM MEM 0024; ElkemSILCOLAPSE from Elkem Silicones TM 7140; Momentive SM2128 from Momentive Performance Materials Inc.; GE SM 2128 from GE Silicones; Dow Corning from Dow 24Emulsion, derived from DowPerformance Silicones MEM-0024, etc.

[0065] Other additives

[0066] In the polymer monofilament of the present invention, other additives may be added as needed, including but not limited to antioxidants, light stabilizers, antistatic agents, lubricants, plasticizers, fillers, antibacterial agents, etc.

[0067] In this invention, the antioxidant can be any antioxidant commonly used in the art. In a preferred embodiment of this invention, the antioxidant is selected from butylated hydroxytoluene (BHT), phenyl-β-naphthylamine, alkyl-p-quinone, thioether, phenyl salicylate, mercaptothioether, thiopropionate, hindered phenol, etc.

[0068] In this invention, the antistatic agent can be any antistatic agent commonly used in the art. In a preferred embodiment of this invention, the antistatic agent is selected from quaternary ammonium salts, ethoxylated amines, aliphatic esters, and sulfonated paraffins, as well as combinations thereof.

[0069] In this invention, the lubricant can be any lubricant commonly used in the art. In a preferred embodiment of the invention, the lubricant is selected from aliphatic esters (e.g., monoglycerides of fatty acids) and combinations thereof.

[0070] In this invention, the plasticizer can be any plasticizer commonly used in the art. In a preferred embodiment of this invention, the plasticizer is selected from terephthalates, phthalates, aliphatic diesters, phosphate esters, chlorinated paraffins, and combinations thereof.

[0071] In this invention, the filler can be any filler commonly used in the art, including but not limited to calcium carbonate, glass fiber, glass sheet, aluminum sheet, glass beads, carbon fiber, talc, mica, wollastonite, calcined clay, kaolin, diatomaceous earth, sodium fluoride, magnesium sulfate, magnesium silicate, barium sulfate, titanium dioxide, sodium aluminum carbonate, potassium titanate, and mixtures thereof.

[0072] Preparation of monofilaments

[0073] The monofilaments used in this invention can be produced using conventional melt spinning technology in the field.

[0074] Generally, the preparation of monofilaments according to the present invention is as follows: the base polymer and other components such as ionomers are heated and melted in a screw extruder, the melt is extruded from the spinneret through a metering pump to form a fine stream, the melt stream is cooled and solidified, then heated and stretched to become thinner, and then coated with silicone oil and wound to obtain the finished monofilament.

[0075] For example, according to embodiments of the present invention, the base polymer and all other components can be mixed before the screw extruder, and then the premixed mixture is fed into the extruder through the feed inlet for melt blending. Alternatively, the base polymer and all other components can be fed directly into the screw extruder through their respective feed inlets for melt blending; or, the base polymer and some components can be mixed first, and then fed into the screw extruder with the remaining components through their respective feed inlets for melt blending. Those skilled in the art can perform the above-described conventional steps according to actual needs.

[0076] According to a preferred embodiment of the invention, the base polymer and all other components can be mixed before the screw extruder, and then the mixed premix is ​​fed into the extruder together for subsequent steps including melt blending.

[0077] According to another preferred embodiment of the invention, the base polymer and all other components can be fed directly into the screw extruder through their respective feed ports, and then further steps, including melt blending, can be performed.

[0078] Silicone oil coating

[0079] In a specific embodiment of the present invention, after obtaining monofilaments through melt extrusion spinning in the art, the monofilaments obtained in the previous steps need to undergo a silicone oil coating process using a silicone oil emulsion. Specifically: before winding, a thin film of silicone oil emulsion is uniformly coated onto the surface of the monofilaments, allowing the silicone oil emulsion to penetrate into the monofilament fibers, while most of the silicone oil emulsion remains on the surface of the monofilament fibers. This facilitates combing the monofilament bundles, resulting in neatly arranged bundles of monofilaments. The amount of silicone oil coated on the monofilament fibers must be appropriate. Excessive coating will cause adhesion between monofilaments and prevent normal transport of the monofilaments on the grafting equipment during subsequent grafting processes; insufficient coating will result in dry and difficult-to-comb bundles, and the entanglement and overlap of monofilaments within the bundle will not be removed. These entanglements and overlaps will lead to defects in the downstream product, i.e., the brush.

[0080] The present invention will be described in more detail below with reference to embodiments. These embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make improvements and adjustments to the described technical solutions without departing from the spirit of the present invention, and the specific scope of protection of the present invention will be defined by the appended claims. Detailed Implementation

[0081] Basic raw material description

[0082] Polybutylene terephthalate (PBT): Commercially available polybutylene terephthalate (PBT) was purchased from Sinopec Yizheng Chemical Fiber Co., Ltd. (PBT L2100).

[0083] Nylon 612: Purchased from Celanese Corporation. 151NC010;

[0084] Isopolymers: All were purchased from Dow Chemical Company, and their specific numbers in the examples are as follows: 9910 (zinc salt of ethylene-methacrylic acid copolymer), 8920 (sodium salt of ethylene-methacrylic acid copolymer);

[0085] Silicone oil: Aqueous emulsions of food-grade polydimethylsiloxane, such as DOWSIL purchased from Dow Inc. TM SH7024.

[0086] Test method description

[0087] Indentation force

[0088] Using an Instron universal testing machine, filament cakes of the same specifications with a diameter of 30-60mm were removed from their paper and laid flat in a semi-circular sample groove. The ends of the filaments were aligned, and the semi-circular sample groove was then mounted on the Instron equipment fixture. A semi-circular probe with a force sensor and an end diameter of approximately 11mm was used to measure the maximum force exerted when the filament cake was slowly pressed into the interior of the cake at a speed of 3mm / min, reaching a depth of 13mm. This force was recorded as the pressing force. The value of this pressing force reflects the lubrication performance of the monofilament, and the pressing force is expressed in Newtons (N).

[0089] In an embodiment of the invention, the better the lubrication performance of the monofilament, the smaller the indentation force on the probe; conversely, the worse the lubrication performance of the monofilament, the higher the indentation force on the probe.

[0090] Comb evaluation

[0091] Using a comb specifically designed for combing bristles with a tooth height of 38mm, a tooth spacing of 4.5mm, and a tooth diameter of approximately 2mm, comb a bristle stick with a diameter of 50±2mm and a length of 1200±15cm. If the comb can comb from one end of the bristle stick to the other, the test result is recorded as successful combing; otherwise, it is recorded as unsuccessful combing.

[0092] Example 1

[0093] Nylon 612 / ionomer composite polymer monofilament coated with silicone oil emulsion

[0094] The general description of the preparation process is as follows:

[0095] 1) Mix 0.5-15% by weight of ionomer with 85-99.5% by weight of nylon 612 resin in a high-speed mixer, then add it to a single (twin) screw extruder for melt blending and extrusion;

[0096] 2) After the melt is extruded and sprayed out by the spinneret, it enters the cooling liquid for cooling. After passing through the slow roller, it enters the hot water tank for drawing, with a drawing ratio of 3-5 times. After drawing, it undergoes heat setting treatment to obtain the initial monofilament.

[0097] 3) At a fixed pulling speed, the monofilament obtained in step 2) is passed through a silicone oil emulsion and then, after winding and other processes, a nylon-based monofilament coated with silicone oil containing nylon 612 / ionomer is prepared.

[0098] 4) Cut the monofilaments obtained in step 3) into lengths of 1-3 meters and perform the combing process as described above, and evaluate the combing process during the process; after the combing process, package them into 50-80mm thick wire rods and cut out wire cakes of a certain size for pressing force testing.

[0099] Specifically: In step 1), the weight ratio of the specific components is shown in Table 1, and the extrusion process is carried out in a single-screw extruder; the stretching ratio in step 2) is 4 times; in step 3), the monofilaments obtained in step 2) are passed through a silicone oil emulsion under a fixed high-speed stretch; in step 4), the monofilaments obtained in step 3) are all cut into 2-meter lengths for combing and combing evaluation; after combing, they are packaged into filament rods with a diameter of 50 mm; then, filament cakes with a height of 29.5 mm are cut out, and the indentation force test related to the lubrication performance of the filament cakes is carried out using an Instron universal testing machine.

[0100] The results are shown in Table 1 below.

[0101] Table 1

[0102]

[0103] *The amount of silicone oil coating was determined using a Bruker Minispec NMR analyzer: the silicone oil content in a given weight (approximately 5.5g) of monofilament was calculated by utilizing the NMR signal intensity as a function of the number of nuclear magnetic moments.

[0104] Example 2

[0105] Polyester PBT / ionomer composite polymer monofilaments coated with silicone oil emulsion

[0106] The melt spinning process of PBT / ionomer monofilaments coated with silicone oil and the process of coating with silicone oil emulsion are similar to those of the nylon-based monofilaments in Example 1, except that the spinning extrusion resin composition and ionomer composition are changed respectively. PBT monofilaments with the same diameter were prepared using materials such as 9910 and 8920. The combing process described in Example 1 was repeated to evaluate the combing process and further test the indentation force.

[0107] The results are shown in Table 2 below.

[0108] Table 2

[0109]

[0110] *The amount of silicone oil coating was determined using a Bruker Minispec NMR analyzer: the silicone oil content in a given weight (approximately 5.5g) of monofilament was calculated by utilizing the NMR signal intensity as a function of the number of nuclear magnetic moments.

[0111] The results showed that for nylon-based and PBT-based monofilaments, the indentation force of the obtained monofilaments without silicone oil coating was very high, indicating poor lubrication performance. Coating the surface of these monofilaments with silicone oil improved the indentation force (reduced the indentation force), and the combing evaluation also yielded positive results. Furthermore, by adding ionomer resin to the nylon and PBT-based monofilaments, the indentation force of the resulting silicone-coated ionomer-containing monofilaments was further improved (further reduced), and the combing evaluation further supported the improved lubrication performance of the obtained monofilaments.

[0112] Specifically, the compressive strength of nylon / ionomer monofilaments coated with the same silicone oil is 1.9 N, compared to 4.1 N for nylon monofilaments without added ionomers, even though they are also coated with silicone oil. Adding ionomers reduces the compressive strength of nylon / ionomer monofilaments by more than half. For PBT / ionomer monofilaments coated with the same silicone oil, the compressive strength can be as low as 0.8 N. For PBT monofilaments without ionomers, although coated with silicone oil, the compressive strength is 1.6 N; adding ionomers reduces the compressive strength of PBT / ionomer monofilaments by approximately half.

[0113] There is no teaching in the prior art regarding the properties of ionomers in this respect.

Claims

1. A composite polymeric filament coated with silicone oil, said filament comprising an ionomer and a nylon (PA) and / or a polyester; wherein the ionomer is an ionomer resin of a copolymer of ethylene with a C3-C8 olefinically unsaturated monocarboxylic acid, and at least a portion of the carboxylic acid is neutralized by metal ions; and, the content of the ionomer is 0.5-15 wt%, preferably 1-10 wt%, based on the total weight of the composite polymeric filament.

2. The composite polymeric filament according to claim 1, wherein the ionomer resin is an ionomer resin of a copolymer of ethylene with a (meth)acrylic acid.

3. The composite polymeric filament according to claim 1, wherein the acid moieties in the ionomer resin are neutralized by metal ions selected from sodium, zinc, lithium, magnesium, calcium, and any mixture thereof.

4. The composite polymeric filament according to claim 3, wherein the acid moieties in the ionomer resin are neutralized by metal ions selected from sodium, zinc, and any mixture thereof.

5. The composite polymeric filament according to any one of claims 1 to 4, wherein the nylon is selected from PA612, PA610, PA512, PA510, PA6, PA66, PA46, PA1010, PA11, PA12, or a combination thereof.

6. The composite polymeric filament according to claim 5, wherein the nylon is PA612.

7. The composite polymeric filament according to any one of claims 1 to 4, wherein the polyester is selected from PET, PBT, PTT, PBS, or a combination thereof.

8. The composite polymeric filament according to claim 7, wherein the polyester is PBT.

9. The composite polymeric filament according to any one of claims 1 to 4, wherein the silicone oil is a food grade silicone oil; the food grade silicone oil includes methyl silicone oil, amino silicone oil, phenyl silicone oil.

10. The composite polymeric filament according to claim 9, wherein the food grade silicone oil is selected from an aqueous emulsion of polydimethylsiloxane.

11. A polymeric material monofilament as claimed in any one of the preceding claims wherein, The polymeric filament further comprises additives, which include antioxidants, light stabilizers, antistatic agents, antibacterial agents, fillers.

12. A method for preparing the composite polymeric filament as claimed in any one of the preceding claims, comprising the following steps: 1) uniformly mixing a base resin of nylon and / or a polyester with the ionomer and optionally other additives in a mixer to obtain a premix; 2) feeding the premix prepared in step 1) into a screw extruder for melt extrusion; after the melt is extruded and discharged from a spinneret, it is subjected to preliminary cooling, and then to post-processing steps such as heat drawing, setting, etc. to obtain a melt-extruded filament; 3) passing the melt-extruded filament in step 2) through a silicone oil emulsion, coating it with silicone oil, and then further winding the product to obtain a polymeric filament comprising an ionomer coated with silicone oil.

13. A method for preparing the composite polymeric filament as claimed in any one of claims 1 to 11, comprising the following steps: 1) the base resin nylon and / or polyester and the ionomer and optionally other additives are separately directly fed into a screw extruder for melt extrusion; the melt is extruded and discharged from the spinneret, then subjected to preliminary cooling, followed by post-processing steps such as heat drawing, setting treatment, etc. to obtain a melt-extruded monofilament; 2) the melt-extruded monofilament in step 1) is passed through a silicone oil emulsion, coated with silicone oil and further subjected to winding of the product to obtain a silicone oil-coated surface monofilament of a high molecular material containing ionomer.

14. A silicone oil-coated surface composite high molecular material monofilament, said high molecular material monofilament containing ionomer and nylon (PA) and / or polyester, and said high molecular material monofilament having a sheath-core structure, wherein the sheath or core layer of said sheath-core structure is composed of said nylon or polyester respectively, and said ionomer is present at least in said sheath layer; wherein said ionomer is an ionomer resin of a copolymer of ethylene and a C3-C8 olefinically unsaturated monocarboxylic acid, and at least a portion of the carboxylic acid is neutralized by a metal ion.

15. A method for improving the lubricating property of a silicone oil-coated surface composite high molecular material monofilament, said method comprising adding ionomer to said high molecular material monofilament, wherein said silicone oil is preferably a food-grade silicone oil selected from the group consisting of methyl silicone oil, amino silicone oil, phenyl silicone oil, etc.; and, wherein said ionomer is an ionomer resin of a copolymer of ethylene and a C3-C8 olefinically unsaturated monocarboxylic acid, and at least a portion of the carboxylic acid is neutralized by a metal ion.

16. A brush made of a composite high molecular material monofilament as claimed in any one of the preceding claims 1 to 11 and 14 or made of a high molecular material monofilament prepared by the method as claimed in claim 12 or 13.

17. The brush of claim 16, wherein, Said brush is a toothbrush.

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