Fadable Multifunctional Monofilament Having a Core-Shell Structure

Abstract

The present invention relates to a fadable multifunctional monofilament. More particularly, the present invention relates to a fadable multifunctional monofilament having a core-shell structure comprising an active substance(s) or a functional filler(s). The present invention also relates to a method for preparing the monofilament material, and a use of the monofilament material in a brush material such as a toothbrush.

Claims

1. A fadable multifunctional monofilament having a core-shell structure, wherein the core layer of the multifunctional monofilament comprises an active substance(s) or a functional filler(s), and the multifunctional monofilament as a whole comprises a dye(s), and a fadable effect is realized by means of gradual release of the dye during use of the multifunctional monofilament; wherein the thickness of the shell layer of the multifunctional monofilament is greater than or equal to 10 m, preferably greater than or equal to 20 m.

2. The multifunctional monofilament according to claim 1, wherein the diameter of the multifunctional monofilament is from 100 m to 254 m, and the thickness of the shell layer is from 20 m to 100 m.

3. The multifunctional monofilament according to claim 1, wherein the active substance(s) contained in the multifunctional monofilament comprise(s) one or more of the followings: NaF, tea polyphenol, Azadirachta indica saponin, and clove oil.

4. The multifunctional monofilament according to claim 1, wherein the functional filler(s) contained in the multifunctional monofilament comprise(s) one or more of the followings: aluminum flakes and mica flakes.

5. The multifunctional monofilament according to claim 1, wherein the proportion of the active substance or the functional filler contained in the multifunctional monofilament is from 0.2 wt % to 10 wt %, based on the total weight of the multifunctional monofilament.

6. The multifunctional monofilament according to claim 1, wherein the shell layer and the core layer of the multifunctional monofilament are composed of a material selected from the group consisting of nylon, polyester, or a combination thereof.

7. The multifunctional monofilament according to claim 1, wherein the dye(s) is/are food grade dye(s).

8. The multifunctional monofilament according to claim 7, wherein the food grade dye(s) comprise(s) an acidic water soluble/disperse dyes, and the water soluble/disperse dyes comprise: indigoid dyes, plant-based natural dyes, methylene blues, anthraquinone dyes.

9. The multifunctional monofilament according to claim 8, wherein the indigoid dyes comprise indigo blue, indigo red, indigo violet, or a combination thereof in any ratio.

10. The multifunctional monofilament according to claim 8, wherein the disperse dyes comprise disperse orange, disperse blue, disperse yellow, disperse red; or disperse black, disperse green or disperse violet obtained by any ratio combination of disperse orange, disperse blue, disperse yellow, and disperse red thereof.

11. The multifunctional monofilament according to claim 8, wherein the plant-based natural dyes comprise curcumin, anthocyanin, shikonin, alizarin red, betalain, and the like.

12. The multifunctional monofilament according to claim 1, wherein the shell layer and/or the core layer in the multifunctional monofilament further comprises an additive(s) selected from the group consisting of antioxidants, light stabilizers, antistatic agents, lubricants, plasticizers, conventional fillers, and antibacterial agents.

13. A process for preparing the multifunctional monofilament according to claim 1, comprising the steps of: 1) adding a base resin, an active substance(s) or a functional filler(s), and optionally other additives to extruder A to provide a melt for forming a core layer of a monofilament having a core-shell structure; and adding the same or different base resin and optionally other additives to extruder B to provide a melt for forming a shell layer of a monofilament having a core-shell structure; 2) converging the above two melts in a co-extrusion spinning pack, after extruding from a spinneret hole(s), cooling and solidifying the converged melt and then performing heat drawing and heat setting to obtain a multifunctional monofilament containing an active substance(s) or a functional filler(s) and having the core-shell structure; 3) dyeing the multifunctional monofilament with the core-shell structure by a dyeing process; 4) optionally performing post-treatment after the dyeing treatment to obtain a final fadable multifunctional monofilament having a core-shell structure.

14. A brush made of the multifunctional monofilament according to claim 1.

15. The brush of claim 14, wherein the brush is a toothbrush.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0011] Except in the examples, or where otherwise expressly indicated, all numbers in this description indicating amounts of material or reaction conditions, physical properties of materials, and/or use are to be understood as optionally modified by a word about.

[0012] All amounts are by weight of the composition unless otherwise specified.

[0013] It should be noted that any specific upper value may be associated with any specific lower value when specifying any numerical range.

[0014] For the avoidance of doubt, the word comprising is intended to mean including, but not necessarily consisting of or composed of. In other words, the listed steps or options need not be exhaustive.

[0015] The disclosure of the invention found herein is considered to cover all embodiments in which the claims are found to be multiply dependent on one another, regardless of the fact that the claims may be found to be free of multiple dependencies or redundancy.

[0016] Where a feature is disclosed with respect to a particular aspect of the invention, such as a composition of the invention, such disclosure is also considered applicable, mutatis mutandis, to any other aspect of the invention, such as a method of the invention.

[0017] Also, the indefinite articles a and an preceding an element or component of the invention are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore a or an should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.

Preparation of Multifunctional Monofilament Having a Core-Shell Structure

[0018] The monofilaments having a core-shell structure can be prepared using techniques well known in the art.

[0019] According to one embodiment of the present invention, a monofilament having a core-shell structure may be prepared by a conventional spinning co-extrusion process. Specifically: [0020] 1) adding a base resin and active or functional filler and optionally other additives to extruder A to provide a melt for forming a core layer of a monofilament having a core-shell structure; and adding the same or different base resin and optionally other additives to extruder B to provide melt for forming a shell layer of a monofilament having a core-shell structure; [0021] 2) converging the above two melts in a co-extrusion spinning pack, after extruding from a spinneret hole, cooling and solidifying the converged melt in a water bath or air, and then performing heat drawing and heat setting, to obtain a monofilament having a core-shell structure and containing an active substance or a functional filler.

[0022] According to the present invention, the shell layer thickness of the multifunctional monofilament having a core-shell structure is at least 10 m. In a preferred embodiment of the present invention, the shell layer thickness of the monofilament having a core-shell structure is equal to and larger than 20 m; the upper limit of the shell thickness of the monofilament is limited only by the conditions of the preparation process. In a more preferred embodiment of the present invention, the shell layer thickness of the monofilament having the core-shell structure is from 20 m to 100 m, most preferably from 20 m to 40 m.

Dyeing of Multifunctional Monofilaments with a Core-Shell Structure:

[0023] After the multifunctional monofilament having the core-shell structure is obtained, it can be dyed by a dyeing process known in the art.

[0024] According to an embodiment of the present invention, the obtained multifunctional monofilament having a core-shell structure is dyed by a dyeing process: immersing the tow of the multifunctional monofilament having a core-shell structure in a dyeing solution, adjusting the pH range of the dyeing solution to from 1 to 7, and then heating the dyeing solution to a temperature such as from 80 C. to 100 C. while maintaining the temperature for 10 to 60 min for dyeing; after dyeing is finished, cooling and washing the monofilament to obtain a dyed monofilament. Finally, the dyed monofilament is subjected to post-treatment such as drying to obtain a finished fadable multifunctional monofilament having a core-shell structure.

[0025] For dyes that can be used in the dyeing process of the present invention, the basic requirement is that the dye used is a food grade dye.

[0026] According to a preferred embodiment of the present invention, the food grade dye comprises an acidic water-soluble/disperse dyes.

[0027] According to a further preferred embodiment of the present invention, the acidic water-soluble/disperse dye is selected from the following types: methylene blue dye; indigo dyes and the like, wherein the indigo dyes include but are not limited to, indigo blue, indigo violet, indigo red, indigo orange; the disperse dye includes, but is not limited to, disperse orange, disperse blue, disperse yellow, disperse red; or disperse black, disperse green, or disperse violet obtained by any ratio combination of disperse orange, disperse blue, disperse yellow, and disperse red thereof, and further includes anthraquinone dye; and the plant-based natural dye which includes, but is not limited to, curcumin, anthocyanin, curcumin, shikonin, alizarin red and betalain, as well as eco-friendly C.I. acid red 249, C.I. acid violet 54, C.I. acid blue 324 dye and the like.

[0028] According to a particularly preferred embodiment of the present invention, indigo dyes useful in the present invention include, but are not limited to, indigo blue and its aluminum lakes, sodium indigo disulfonate. According to a particularly preferred embodiment of the present invention, the plant-based natural dyes useful in the present invention include, but are not limited to, curcumin, anthocyanin, shikonin, alizarin red, betalain, and the like.

Base Resin

[0029] In principle, there is no particular limitation on the material for preparing the multifunctional monofilament of the present invention, and the common materials for preparing the monofilament in the art can be used in the preparation of the monofilament of the present invention.

[0030] According to an embodiment of the present invention, the base resin of the multifunctional monofilament useful in the present application includes polyamide (nylon), polyester, etc.

Polyamide PA (Nylon)

[0031] One exemplary type of the base resin that may be used in the present invention is polyamide or commonly known nylon.

[0032] The polyamides useful in the present invention have a linear backbone which can be produced by reacting a dicarboxylic acid with a diamine to form a linear condensed polyamide. Non-limiting examples of dicarboxylic acids include C6 to C12 aliphatic dicarboxylic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and non-limiting examples of diamines include linear aliphatic or cycloaliphatic diamines such as ethylenediamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, isophorone diamine, and 1,4-cyclohexanebis (methylamine), decanediamine, and non-limiting examples of diamines can also include linear aromatic diamines such as phenylenediamine and benzidine. Polyamides useful in the present invention may also be produced by the reaction of amino-containing carboxylic acid compounds or lactams thereof. Non-limiting examples of amino-containing carboxylic acid compounds include C6 to C12 aliphatic terminal aminocarboxylic acid compounds such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid.

[0033] Exemplary base resin polyamides include PA612, PA610, PA512, PA510, PA6, PA66, PA46, PA1010, PA11, PA12, or mixtures thereof according to well-known nomenclature in the art for polyamide materials.

[0034] In a particularly preferred embodiment, the base resin employed is PA612, such as nylon PA612 Zytel 151 NC010 available from Celanese.

Polyester

[0035] Another class of exemplary base resins useful in the present invention is polyester.

[0036] Non-limiting examples of polyester(s) include the reaction product of terephthalic acid and ethylene glycol, i.e., polyethylene terephthalate (PET), and similarly, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT). In addition, various modified polyesters may also be used in the present invention, and non-limiting examples thereof include: polybutylene succinate (PBS), polylactic acid (PLA), polys-caprolactone (PCL), poly3-hydroxybutyrate (PHB), polyhydroxyvalerate (PHV), etc. Copolyesters include, for example, polybutylene adipate/terephthalate (PBAT), polybutylene sebacate/adipate (PBSA), co-hydroxyalkanoates, and the like.

[0037] Exemplary representative of polyesters useful in the present invention include PET, PBT, PTT, etc.

Active Substances

[0038] Exemplary actives that may be used in the present invention include sodium fluoride, tea polyphenols, Azadirachta indica saponin, clove oil, and the like.

Sodium Fluoride

[0039] Sodium fluoride is a well-known anticaries compound that has long been used in toothpaste products to provide corresponding technical effects.

[0040] According to an embodiment of the present invention, sodium fluoride NaF is added to the core layer of the multifunctional monofilament having a core-shell structure as an active used in the present invention.

[0041] Commercially available sodium fluoride products are all useful in the present invention. The size of the sodium fluoride particles does not exceed the diameter of the monofilament.

Other Actives

[0042] Exemplary other common actives that may be used in the present invention according to embodiments of the present invention include tea polyphenols, Azadirachta indica saponin, clove oil, and the like, wherein:

[0043] Tea polyphenols: Tea polyphenols are an extract of tea leaves. The tea polyphenol has a high free hydroxyl content and can be combined with salivary protease to improve bacterial reproduction caused by protein precipitation in the oral cavity; meanwhile, the tea polyphenol also has an obvious plant antibiotic effect and can improve oral inflammation.

[0044] Commercially available tea polyphenol products are useful in the present invention, for example, available from KOEI, Dayang, Wuhan Fortuna, Parchem, etc.

[0045] Azadirachta indica Saponin: Azadirachta indica saponin eliminates free radicals and has antioxidant effects. It also inhibits various fungi and bacteria, serving as an antibacterial, an anti-inflammatory agent and an anti-plaque agent,

[0046] For example, the commercially available Azadirachta indica Saponin products can be purchased from Chengdu Symphs Biotechnology, Hubei Guango Biotechnology, Shanghai Research Biotechnology, etc.

[0047] clove oil: clove oil is an oil extracted from clove leaves, has a certain medicinal value, and has analgesic, antibacterial and anti-inflammatory effects, and can be used for oral pain relief, anti-inflammatory and caries prevention.

[0048] All commercially available clove oils can be used in the present invention, for example, the clove oils can be purchased from Shanghai source leaf biotechnology Co., Ltd., Nanjing chemical reagent Co., Ltd., etc.

Functional Fillers

[0049] Functional fillers may be used in the preparation of the core layers of the multifunctional monofilaments of the present invention having a core-shell structure to provide particular functional technical effects; such as imparting a shiny effect to the monofilaments.

[0050] Exemplary functional fillers useful in the present invention include aluminum flakes, mica flakes, and the like.

[0051] Aluminum flakes: a tiny sized aluminum flakes can be used to bring a flickering aesthetic effect to the brush filaments.

[0052] In principle, the use of the aluminum flakes is not particularly limited as long as it can be suitably incorporated into the monofilament according to the present invention.

[0053] According to one embodiment of the present invention, the aluminum flakes suitable for use in the present invention have, for example, a thickness of 10-30 m and a length/width (i.e., length or width) of 20-140 m. Commercially available aluminum flakes can be used in the present invention. For example, the aluminum flakes are commercially available from Hefei Keji, Zhongti Xincai, Avient, etc.

[0054] According to another embodiment of the present invention, the mica flakes may also be used to prepare a monofilament material having an aesthetic effect similar to that of flashing.

[0055] The use of the mica is not particularly limited in principle, as long as it can be suitably incorporated into the brush filaments.

[0056] Commercially available mica flakes can be used in the present invention. For example, the mica flakes are commercially available from Imerys Minerals, The Earth Pigments Company, Reade International, MATSUO SANGYO, Yamaguchi, and the like.

[0057] In one embodiment of the present invention, based on the total weight of the multifunctional monofilament, the active substance or functional filler is added in an amount ranging from 0.2 wt % to 10 wt %, preferably from 0.5 wt % to 6 wt %; more preferably from 0.8 wt % to 4 wt %.

Other Additives

[0058] In the polymeric monofilament of the present invention, other additives may also be added as required, including but not limited to antioxidants, light stabilizers, antistatic agents, lubricants, plasticizers, conventional fillers, antibacterial agents, etc.

[0059] In the present invention, the antioxidant may be any antioxidant commonly used in the art, and in a preferred embodiment of the present invention, the antioxidant is selected from the group consisting of dibutylhydroxytoluene (BHT), phenyl-beta-naphthylamine, alkyl-p-quinone, thioether, phenyl salicylate, mercaptosulfide, thio-propionate, hindered phenols, and the like.

[0060] In the present invention, the antistatic agent may be any antistatic agent commonly used in the art, and in a preferred embodiment of the present invention, the antistatic agent is selected from the group consisting of quaternary ammonium salts, ethoxylated amines, aliphatic esters, sulfonated paraffins, and combinations thereof.

[0061] In the present invention, the lubricant may 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.

[0062] In the present invention, the plasticizer may be any plasticizer commonly used in the art, and in a preferred embodiment of the present invention, the plasticizer is selected from the group consisting of terephthalates, phthalates, aliphatic dibasic acid esters, phosphates, chlorinated paraffin and combinations thereof.

[0063] In the present invention, the conventional filler may be any filler commonly used in the art, including but not limited to calcium carbonate, glass fiber, glass flake, glass bead, carbon fiber, talc, wollastonite, calcined clay, kaolin, diatomaceous earth, sodium fluoride, magnesium sulfate, magnesium silicate, barium sulfate, titanium dioxide, sodium aluminum carbonate, potassium titanate, and mixtures thereof.

[0064] The present invention will be described in more detail below with reference to the examples, and the examples of the present invention are only used to illustrate the technical solutions of the present invention, and are not used to limit the scope of the present invention. Those skilled in the art can make improvements and adjustments to the technical solutions without departing from the spirit of the present disclosure, and the specific protection scope of the present disclosure will be defined by the appended claims.

EXAMPLES

[0065] The raw materials used in the examples were as follows:

[0066] Nylon 612: Nylon 612 was Nylon 612 Zytel 151 NC010 purchased from Celanese.

[0067] Sodium fluoride NaF: Sodium fluoride was that purchased from Qiaoli Chemical Co., Ltd, with an average particle size of less than 45 m.

[0068] Aluminum flakes: Aluminum flakes were purchased from Avient, with a thickness of about 20 m and a maximum length or width less than 120 m.

[0069] Dyes: Dyes were methylene blue purchased from SENSIENT, and indigo violet purchased from Archroma Chemical.

[0070] The specific dyeing process was exemplified as follows: preparing a dyeing solution containing a dye(s) with the target color, and adjusting the concentration and pH of the dyeing solution. Immersing more than 10 Kg of multifunctional monofilaments having a core-shell structure into 110 Kg of dyeing solution under heating to a set dyeing temperature and a set dyeing holding time. After the dyeing process was completed, the temperature of the dyeing solution was reduced, the dyed monofilament was taken out, and the monofilament was washed with water to obtain the dyed monofilament.

Example 1

[0071] Sodium fluoride NaF was used as the active substance.

[0072] A blank nylon 612 monofilament sample having a diameter of 0.152 mm (i.e., 152 m) and a core layer added with 1 weight % (based on the weight of the monofilament) of active substance NaF (i.e., a shell layer thickness of 0), and blank nylon 612 monofilament samples with a core-shell structure (with a shell layer thickness of 20 m, 25 m, 30 m, respectively) having the same initial addition amount of active substance NaF were prepared by a melt co-extrusion spinning process.

[0073] The obtained nylon 612 monofilaments containing NaF were dyed by a dyeing process to obtain a dyed multifunctional monofilament. Wherein, under the ratio of monofilament/dyeing solution as described above, 10 g of the multifunctional monofilaments having the core-shell structure were immersed in 110 g of the dyeing solution. The dyeing temperature was 90 C., the dyeing holding time was 10 mins, the concentration of the dyeing solution was around 1 wt %, and the pH of the dyeing solution was set to about 2. The dye in the dyeing solution was methylene blue.

[0074] The retentions of the added active substance NaF of nylon 612 monofilaments without and with a core-shell structure after dyeing relative to the above blank samples were measured by an ion chromatography.

Measurement of NaF Retention:

[0075] 1 g mass of monofilaments with the same 30 mm length before and after dyeing were weighed respectively, placed in 30 ml of water and soaked at room temperature for 2 hours; then the monofilament samples were taken out, and the contents of element F in the soaking solution were measured for the monofilaments before and after dyeing via ion chromatography. The NaF Retention was calculated according to the following equation.

[00001]$\mathrm{NaF}\mathrm{Retention}\left(\%\right)=\frac{F\mathrm{element}\mathrm{concentration}\mathrm{in}\mathrm{the}\mathrm{soaking}\mathrm{solution}\mathrm{after}\mathrm{dyeing}}{F\mathrm{element}\mathrm{concentration}\mathrm{in}\mathrm{the}\mathrm{soaking}\mathrm{solution}\mathrm{before}\mathrm{dyeing}}$

[0076] The greater the ratio of NaF retention, the higher the NaF retention.

[0077] The data were shown in Table 1 below:

TABLE-US-00001 TABLE 1 Monofilament Shell Layer Diameter Thickness NaF Retention Base Resin (Unit: mm) (Unit: m) after dyeing Nylon 612 (Comparative) 0.152 0 21.4% Nylon 612 (Inventive) 0.152 20 30.7% Nylon 612 (Inventive) 0.152 25 31.4% Nylon 612 (Inventive) 0.152 30 36.7%

[0078] The results showed that the greater the thickness of the shell layer, the higher the NaF retention of the fadable monofilament having the core-shell structure after the dyeing process; especially, after the thickness of the shell layer reached 20 m, the NaF retention increased to 30.7%; while the NaF-containing monofilament without a core-shell structure just had a retention of 21.4% for the active substance NaF.

Example 2

[0079] An example of adding a functional filler: aluminum flakes were used as the functional filler.

[0080] A blank nylon 612 monofilament sample without a core-shell structure (i.e., having a shell thickness of 0) having an aluminum flake addition of 1 wt % (based on the weight of the monofilament) and a monofilament diameter of 0.152 mm (i.e., 152 m), and blank nylon 612 monofilaments with the core-shell structure (having a shell thickness of 10 m, 15 m, and 20 m, respectively) and having the same aluminum flake addition amount were respectively prepared by a melt co-extrusion spinning process.

[0081] The obtained nylon 612 monofilaments containing the aluminum flakes were dyed by a dyeing process to obtain dyed multifunctional monofilaments. Wherein 10 g of the monofilaments containing the functional filler and having the core-shell structure were immersed into 110 g of the dyeing solution. The dyeing temperature was 90 C., the dyeing holding time was 10 mins, the concentration of the dyeing solution was around 1%, and the pH of the dyeing solution was set to around 5. The dye in the dyeing solution was indigo violet.

[0082] The retention of the functional filler aluminum flakes of the monofilament after the dyeing process was completed was measured.

[0083] Measurement of the Retention of the aluminum flakes: 3-5 g of monofilaments having the core-shell structure and the aluminum flake content of 1%, and monofilaments without the core-shell structure but having the same aluminum flake content of 1%, both of which having the same weight and the same length of 30 cm, were weighed respectively, and were dyed in a dyeing solution containing 1% dye. The monofilaments were immersed in the dyeing solution completely. After dyeing, the dyeing solution was filtered through filter paper, the weight of the filter paper was measured after the filter paper was dried; by minus the dry weight of the filter paper before use, the weight of the aluminum flake remaining on the filter paper were obtained and recorded as the weight of the shed aluminum flake.

[0084] The retention of the aluminum flake was calculated according to the following equation:

[00002]$\mathrm{Retention}\mathrm{of}\mathrm{aluminum}\mathrm{flake}\left(\%\right)=1-\frac{\mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{the}\mathrm{shed}\mathrm{aluminum}\mathrm{flake}}{\mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{aluminum}\mathrm{flake}\mathrm{added}\mathrm{in}\mathrm{the}\mathrm{filament}}$

[0085] The results were summarized in Table 2 below.

[0086] The results showed that when the thickness of the shell layer was 0, that is, when there was no core-shell structure, the nylon monofilament lost a large amount of aluminum flakes in the dyeing process; and the retention of the aluminum flakes was as low as 72%; and when the thickness of the shell layer was 10 m, the retention of the nylon 612 monofilament functional filler aluminum flakes was as high as 100%.

TABLE-US-00002 TABLE 2 Monofilament Shell Layer Diameter Thickness Retention of Aluminum Base Resin (Unit: mm) (Unit: m) flake after dyeing Nylon 612 0.152 0 72% Nylon 612 0.152 10 100% Nylon 612 0.152 15 100% Nylon 612 0.152 20 100%

[0087] It can be seen from the experimental results in Table 2 that, for the multifunctional monofilament with the core-shell structure added with the aluminum flakes, slightly different from the monofilament with the core-shell structure added with active NaF, a satisfactory retention of the aluminum flakes was actually obtained when the thickness of the shell layer was 10 m or more.