Toothbrush filament and manufacturing method thereof, toothbrush

Abstract

A method for manufacturing a toothbrush filament, and the manufactured toothbrush filament and toothbrush, which includes melt extrusion of a piezoelectric polymer and undergoes corona polarization and annealing processes, thereby making the piezoelectric constant of the toothbrush filament in a stationary state 0.4 pC / N or more, and having a certain stably present polarization charge on its surface, and utilizing the antibacterial action mechanism based on physical electrical stimulation, can effectively improve the problem of mass bacterial proliferation on the toothbrush filament in a stationary state, thereby improving the antibacterial performance of the toothbrush filament.

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on May 9, 2022, bearing application number 202210502051.9 and titled "Toothbrush filament and manufacturing method thereof, toothbrush", and a Chinese patent application filed with the China Patent Office on June 10, 2022, bearing application number 202210655802.0 and titled "Toothbrush filament and manufacturing method thereof, toothbrush", the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of oral hygiene, and in particular to toothbrush filaments and methods of making same, and to toothbrushes. [Background technology]

[0003] Toothbrushes are everyday items whose function is to keep the mouth clean and hygienic by cleaning the oral cavity and cleaning the teeth and gums. The filaments of traditional toothbrushes are generally made of natural hog bristles or nylon materials.

[0004] Natural hog hair is superior to nylon material in both cleaning effect and toothpaste adsorption ability, but its use range is limited due to limited sources. On the other hand, nylon material has relatively good toughness but lacks antibacterial function. During use, toothbrush filament comes into contact with water or food residue, and food residue remains on toothbrush filament, which is difficult to remove thoroughly, so that a large amount of bacteria grows on toothbrush filament with prolonged use, which is easy to cause oral infection after repeated use, and affects the health of the body. In addition, traditional toothbrush only plays the role of cleaning food residue in the oral cavity, lacks antibacterial function, and does not play the role of inhibiting or removing bacteria on the tooth surface, which has a detrimental effect on the prevention of some oral diseases, such as dental caries or periodontal disease. Therefore, improving the antibacterial performance of toothbrush filament is an urgent problem to be solved. Summary of the Invention

[0005] The present application aims to provide a toothbrush filament and a manufacturing method thereof, and a toothbrush, so as to improve the antibacterial performance of the toothbrush filament. Specific embodiments are as follows:

[0006] In a first aspect of the present application, there is provided a method for producing a toothbrush filament, the method comprising the steps of: (1) A piezoelectric polymer is added to a melt spinning machine, heated to the melting temperature of the piezoelectric polymer, and extruded to obtain threads with a diameter of 100 μm to 500 μm, and the piezoelectric constant of the piezoelectric polymer is 10 pC / N to 32 pC / N. (2) The thread is annealed at 120°C to 150°C for 1.5h to 3h, and then the annealed thread is subjected to corona polarization to obtain a toothbrush filament, the voltage of the corona polarization is 10kV to 50kV, the distance between the electrode and the sample is 10mm to 50mm, the polarization temperature is 25°C to 50°C, and the time is 10min to 60min, preferably the annealing temperature is 120°C to 140°C, the time is 2h to 3h, the voltage of the corona polarization is 20kV to 50kV, the distance is 20mm to 50mm, the temperature is 25°C to 50°C, and the time is 10min to 40min. Or, (2') After the thread is subjected to corona polarization treatment, it is annealed at 120°C to 150°C for 1.5h to 3h to obtain a toothbrush filament, in which the corona polarization treatment voltage is 10kV to 50kV, the distance is 10mm to 50mm, the temperature is 25°C to 50°C, and the time is 10min to 60min, and preferably the corona polarization treatment voltage is 20kV to 50kV, the distance is 20mm to 50mm, the temperature is 25°C to 50°C, and the time is 10min to 40min, and the annealing treatment temperature is 120°C to 140°C, and the time is 2h to 3h.

[0007] In some embodiments of the present application, the piezoelectric polymer is at least one selected from polyvinylidene fluoride, polyvinylidene fluoride-trifluoroethylene copolymer, or polyvinylidene fluoride-hexafluoropropylene copolymer.

[0008] In a second aspect, the present application provides a toothbrush filament manufactured using the manufacturing method of any of the above-described embodiments.

[0009] In some embodiments of the present application, the filament of the toothbrush generates a voltage of 0.6V to 1.5V when subjected to an external force.

[0010] In some embodiments of the present application, the toothbrush filament has a monofilament bend recovery of 60% to 80%.

[0011] In some embodiments of the present application, the toothbrush filaments have a piezoelectric constant at rest of 0.4 pC / N or greater.

[0012] In some embodiments of the present application, the toothbrush filaments have an antibacterial rate of 45% to 80%.

[0013] In a third aspect of the present application, there is provided a toothbrush, including a traditional manual toothbrush or an electric toothbrush, comprising a filament of the toothbrush of any of the preceding embodiments.

[0014] The advantageous effects of the present invention are as follows: The present application provides a toothbrush filament and its manufacturing method, and a toothbrush, and the toothbrush filament is manufactured using the manufacturing method of the present application, and the temperature and time of the annealing treatment are controlled, and the voltage, distance, temperature and time of the corona polarization treatment are controlled within the above ranges, so that the manufactured toothbrush filament has good piezoelectricity and monofilament bending recovery rate, specifically, the toothbrush filament has a piezoelectric constant of 0.4 pC / N or more in a stationary state, has a certain and stable polarization charge on its surface, and utilizes the antibacterial action mechanism by physical electrical stimulation to effectively improve the problem of bacteria multiplying in the toothbrush filament in a stationary state, thereby improving the antibacterial performance of the toothbrush filament. The voltage generated by the action of external force (corresponding to the toothbrush process) is 0.6V to 1.5V, and thus the piezoelectric signal of the toothbrush filament in the cleaning process can effectively remove bacteria on the tooth surface, which contributes to the prevention of dental diseases such as dental caries and periodontal disease. In addition, the monofilament bending recovery rate of the toothbrush filament is 60% to 80%, which satisfies the requirements for use of the toothbrush. Of course, it is not necessary for all of the above advantages to be realized simultaneously in practicing any product or method herein.

[0015] In order to more clearly explain the configuration of the embodiments of the present invention and the prior art, the drawings necessary for use in the embodiments and the prior art will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings from these drawings without any creative ingenuity. [Brief description of the drawings]

[0016] [Figure 1] 1 is a dynamic piezoelectric signal test chart of the filaments of the toothbrushes of Example 1, Example 2, Example 12, Example 13, Comparative Example 1, and Comparative Example 2 under the action of external force. [Diagram 2] 1 is a graph showing test results of the static piezoelectric constant d33 of the toothbrush filaments of Examples 1, 2, 12, 13, and Comparative Examples 1 and 2. [Diagram 3] 1 is a test chart showing the antibacterial performance of the toothbrush filaments of Examples 1, 2, 12, 13, and Comparative Examples 1 and 2. [Figure 4] FIG. 4a (400x) and FIG. 4b (5000x) are electron microscope photographs of the toothbrush filament of Example 1 after co-cultivation with bacteria for 24 hours. [Diagram 5] FIG. 5a (400x) and FIG. 5b (5000x) are electron microscope photographs of the toothbrush filaments of Example 2 after co-cultivation with bacteria for 24 hours. [Figure 6] Figure 6a (400x) and Figure 6b (5000x) are electron micrographs of the toothbrush filaments of Example 12 after 24 hours of co-cultivation with bacteria. [Figure 7] Figure 7a (400x) and Figure 7b (5000x) are electron microscope photographs of the toothbrush filament of Example 13 after co-cultivation with bacteria for 24 hours. [Figure 8] FIG. 8a (400x) and FIG. 8b (5000x) are electron microscope photographs of the filaments of the toothbrush of Comparative Example 1 after co-cultivation with bacteria for 24 hours. [Figure 9] FIG. 9a (400x) and FIG. 9b (5000x) are electron microscope photographs of the filaments of the toothbrush of Comparative Example 2 after co-cultivation with bacteria for 24 hours. [Figure 10] 1 shows X-ray diffraction spectra of toothbrush filaments of Examples 1, 2, 12, 13, and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In order to make the object, embodiment and advantages of the present invention clearer, the present invention will be described in more detail below with reference to the drawings and examples. Obviously, the described examples are only some of the examples of the present invention, and are not all of the examples. Any other examples made by those skilled in the art based on the examples of the present invention without inventive ideas are all within the scope of the present invention.

[0018] In a first aspect of the present application, there is provided a method for producing a toothbrush filament, the method comprising the steps of: (1) A piezoelectric polymer is added to a melt spinning machine, heated to the melting temperature of the piezoelectric polymer, and extruded to obtain threads with a diameter of 100 μm to 500 μm, and the piezoelectric constant of the piezoelectric polymer is 10 pC / N to 32 pC / N. (2) The yarn is annealed at 120°C to 150°C for 1.5h to 3h, and then the annealed yarn is corona polarized to obtain toothbrush filaments, in which the corona polarization voltage is 10kV to 50kV, the distance between the electrode and the sample is 10mm to 50mm, the polarization temperature is 25°C to 50°C, and the time is 10min to 60min, and preferably the annealing temperature is 120°C to 140°C, the time is 2h to 3h, the corona polarization voltage is 20kV to 50kV, the distance is 20mm to 50mm, the temperature is 25°C to 50°C, and the time is 10min to 40min. For example, the temperature of the annealing treatment may be 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or a range between any two of these values, and the time of the annealing treatment may be 1.5h, 1.8h, 2h, 2.2h, 2.5h, 3h, or a range between any two of these values. For example, the voltage of the corona polarization treatment may be 10KV, 20KV, 30KV, 40KV, 50KV, or a range between any two of the values, the distance of the corona polarization treatment may be 10mm, 20mm, 30mm, 40mm, 50mm, or a range between any two of the values, the temperature of the corona polarization treatment may be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, or a range between any two of the values, and the time of the corona polarization treatment may be 10min, 20min, 30min, 40min, 50min, 60min, or a range between any two of the values. Or, (2') After the thread is subjected to corona polarization treatment, it is annealed at 120°C to 150°C for 1.5h to 3h to obtain a toothbrush filament, in which the corona polarization treatment voltage is 10kV to 50kV, the distance is 10mm to 50mm, the temperature is 25°C to 50°C, and the time is 10min to 60min, and preferably the corona polarization treatment voltage is 20kV to 50kV, the distance is 20mm to 50mm, the temperature is 25°C to 50°C, and the time is 10min to 40min, and the annealing treatment temperature is 120°C to 140°C, and the time is 2h to 3h. For example, the voltage of the corona polarization treatment may be 10KV, 20KV, 30KV, 40KV, 50KV, or a range between any two of these values; the distance of the corona polarization treatment may be 10mm, 20mm, 30mm, 40mm, 50mm, or a range between any two of these values; the temperature of the corona polarization treatment may be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, or a range between any two of these values; and the time of the corona polarization treatment may be 10min, 20min, 30min, 40min, 50min, 60min, or a range between any two of these values. For example, the temperature of the annealing treatment may be 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or a range between any two of these values, and the time of the annealing treatment may be 1.5h, 1.8h, 2h, 2.2h, 2.5h, 3h, or a range between any two of these values.

[0019] The annealing treatment improves the degree of crystallinity of the polymer, thereby improving the plasticity and toughness of the toothbrush filament and helping to remove residual stress. If the annealing temperature is too low (e.g., less than 120°C) or the time is too short (e.g., less than 1.5h), the annealing is incomplete and affects the physical properties of the toothbrush filament, such as the monofilament bending recovery rate. If the annealing temperature is too high (e.g., more than 150°C) or the time is too long (e.g., more than 3h), it not only affects the practical feasibility, but also affects the mechanical properties of the toothbrush filament itself.

[0020] The corona polarization treatment can charge a certain polarization charge on the surface of the toothbrush filament, and improve the piezoelectric performance of the toothbrush filament. If the voltage of the corona polarization treatment is too low (e.g., less than 10 KV), the distance is too large (e.g., more than 50 mm), the temperature is too low (e.g., less than 25°C), or the time is too short (e.g., less than 10 min), the corona polarization treatment will be incomplete, which will directly affect the improvement of the piezoelectric performance of the toothbrush filament. If the voltage of the corona polarization treatment is too high (e.g., less than 50 KV), super )) and the distance is too small (e.g., more than 10 mm less than )) If the temperature is too high (e.g., above 50°C) or the time is too long (e.g., above 60 minutes), not only will there be a high safety risk during use, but the mechanical properties of the toothbrush filaments will also be affected.

[0021] Generally speaking, the toothbrush filament manufactured by using the above manufacturing method, annealing the thread and then corona poling, or corona poling the thread and then annealing, controlling the temperature and time of the annealing, and controlling the voltage, distance, temperature and time of the corona poling within the above ranges, has good piezoelectricity and monofilament bending recovery rate, specifically, the toothbrush filament has a piezoelectric constant of 0.4pC / N or more in a stationary state, has a certain and stable polarization charge on its surface, and utilizes the antibacterial action mechanism of physical electrical stimulation to effectively improve the problem of bacteria multiplying in the toothbrush filament in a stationary state, thereby improving the antibacterial performance of the toothbrush filament. The voltage generated by the action of external force (corresponding to the toothbrush process) is 0.6V to 1.5V, so that the piezoelectric signal of the toothbrush filament in the cleaning process can effectively remove bacteria on the tooth surface, which is advantageous for preventing dental diseases such as dental caries and periodontal disease. Under the premise of satisfying the lowest annealing temperature and time, the monofilament bending recovery rate of the toothbrush filament is 60%-80%, which is in accordance with the Chinese national standard GB 19342-2013 ("Toothbrush") and meets the requirements for toothbrush use. Wherein, the above-mentioned external force is ultrasonic vibration of 40,000 times / min. Wherein, the toothbrush filament has a piezoelectric constant of 0.4pC / N or more in a rest state, which is smaller than the piezoelectric constant of the piezoelectric polymer used to manufacture the toothbrush filament.

[0022] In some embodiments of the present application, the piezoelectric polymer is at least one selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride-trifluoroethylene copolymer, or polyvinylidene fluoride-hexafluoropropylene copolymer. The piezoelectric constants of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-trifluoroethylene copolymer, and polyvinylidene fluoride-hexafluoropropylene copolymer are 18 pC / N to 22 pC / N, 25 pC / N to 29 pC / N, and 27 pC / N to 30 pC / N, respectively. PVDF is a polycrystalline semi-crystalline polymer, and there are three commonly seen crystal forms, which are α phase, β phase, and γ phase, respectively, of which β phase is a ferroelectric phase, and the ratio directly determines the polarization charging effect and piezoelectric performance of PVDF. The post-treatment process directly affects the crystal phase of PVDF. In this application, the proportion of β phase in PVDF can be significantly increased by using a post-treatment process that combines annealing and corona polarization treatment, thereby improving the piezoelectric performance of the toothbrush filaments produced, and thereby realizing the antibacterial function of the toothbrush filaments.

[0023] In the present application, there is no particular limitation on the melting temperature of the piezoelectric polymer as long as the object of the present application can be achieved, and for example, the melting temperature of the piezoelectric polymer may be 130° C. to 220° C., and further, the melting temperatures of the above-mentioned PVDF, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE), and polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) are 165° C. to 175° C., 212° C. to 217° C., and 130.9° C. to 180° C., respectively. In the present application, there is no particular limitation on the molecular weight of the piezoelectric polymer as long as the object of the present application can be achieved, and for example, the weight average molecular weights of the above-mentioned PVDF, polyvinylidene fluoride-trifluoroethylene, and polyvinylidene fluoride-hexafluoropropylene are 150,000 to 300,000, 100,000 to 200,000, and 700,000 to 900,000, respectively.

[0024] In the present application, there is no particular limitation on the melt spinning machine used in the above-mentioned production method, and any melt spinning machine known in the art can be used, and there is no particular limitation in the present application as long as the object of the present application can be achieved. In a second aspect of the present application, there is provided a toothbrush filament manufactured using the manufacturing method of any of the above-mentioned embodiments. The toothbrush filament manufactured using the above-mentioned manufacturing method has good piezoelectric performance and monofilament bending recovery rate, specifically, the toothbrush filament has a piezoelectric constant of 0.4 pC / N or more in a stationary state, a voltage signal generated by the action of an external force of 0.6 V to 1.5 V, and a monofilament bending recovery rate of the toothbrush filament is 60% to 80%.

[0025] In some embodiments of the present application, the antibacterial rate of the toothbrush filaments is 45% to 80%, indicating good antibacterial performance.

[0026] In a third aspect of the present application, there is provided a toothbrush including the toothbrush filament according to any of the above-mentioned embodiments, wherein the toothbrush filament has good piezoelectric performance and monofilament bending recovery rate, so that the toothbrush according to the present application has good antibacterial performance and usability, and the piezoelectric response of the toothbrush filament during the cleaning process can also effectively remove bacteria on the tooth surface, which is helpful in improving dental diseases such as tooth spot bacteria and periodontal disease.

[0027] Measurement methods and equipment: Dynamic Piezoelectric Performance Measurement: The filament was cut to a length of 10 cm and held in a clamp to make the filament taut. Conductive adhesive and electrodes were attached to both ends, and the electrodes connected to both ends were each connected to a Keithley electrometer (Keithley 6514) and ultrasonic vibrations at a frequency of 40,000 times per minute were applied, causing regular fluctuations in the filament movement device, and the voltage output was received on a screen.

[0028] Static Piezoelectric Performance Measurement: For the filaments of the toothbrushes of the different examples and comparative examples, the quasi-static d 33 The piezoelectric constant d of the toothbrush filament was measured using a measuring instrument (ZJ-6A, Institute of Acoustics, Chinese Academy of Sciences). 33The toothbrush filament material was measured, the edge of which was lightly pinched with small tweezers and placed between the measuring electrodes at both ends of the quasi-static measuring device, the upper button was gently rotated to lightly bring the two electrodes into contact, the data displayed on the screen was recorded, and measurements were taken at five points for each filament, with the average being the final measurement result.

[0029] Tensile strength and elastic modulus measurements: Before applying the load, the initial distance between the clamps of the tensile test bench (Instron-1121, Cambridge) was adjusted to 100 mm ± 5 mm. The toothbrush filament was immersed in deionized water for 1 min, then fixed between the two clamps, and a load was applied at a crosshead speed of (300 ± 50) mm / min. The strain vs. load relationship was recorded until the filament broke, and the tensile strength and elastic modulus were measured.

[0030] Measurement of hair bundle tension, hair bundle bending force, and monofilament bending recovery rate: The tuft tension, tuft bending force, and monofilament bending recovery were all measured according to Chinese national standard GB 19342-2013.

[0031] Antibacterial performance measurement: (1) Preparation of brain heart infusion medium (BHI liquid medium): 7.4 g of BHI powder (200.0 g bovine brain, 250.0 g bovine heart infusion, 10.0 g peptone, 2.0 g glucose, 5.0 g NaCl, 20.0 g agar) was weighed, 400 ml of deionized water was added, and the mixture was mixed uniformly. The mixture was then heated at 120°C under high pressure for use. Preparation of solid medium: 2% agar powder was added to the dissolved liquid medium, sterilized under high pressure, and cooled to 70°C. The mixture was poured into a 9 cm culture dish in a clean bench, and after cooling, the dish was inverted, sealed, and stored in a refrigerator at 4°C. (2) The experimental strain selected was Streptococcus mutans ua159, a bacterium that causes dental caries. The experimental strain was resuscitated and inoculated onto solid medium, then cultured for 24 hours in a 37°C, 5% CO2 incubator. Some colonies were then sampled and Gram stained, and the morphology of the colonies was observed under an optical microscope. After it was confirmed that there was no contamination, some were subcultured in preparation for use. (3) The filaments of the toothbrushes of each of the Examples and Comparative Examples were disinfected with absolute ethanol and then co-cultured with Streptococcus mutans in BHI liquid medium for 24 hours. (4) Preparation of staining solution: The fluorescent staining agent contains two types of dyes, SYT09 dye and PI dye, which can cause live bacteria to emit green fluorescence and dead bacteria to emit red fluorescence. Before staining, the SYT09 dye and dyeing agent were mixed in equal proportions in the dark and placed in the same centrifuge tube (Ep tube), shaken to mix uniformly, and then shaded for use. (5) The toothbrush filament was co-cultured with mutans bacteria in BHI liquid medium for 24 hours, and the supernatant was removed with a pipette and the medium was carefully washed once with sterile saline to wash away the suspended bacteria. (6) An appropriate amount of the staining solution was dropped onto the plaque / biofilm surface and incubated at room temperature in a dark room for 15 minutes. Excess dye was removed by careful rinsing with PBS buffer solution. The toothbrush filaments of each Example and Comparative Example were placed on a slide glass and observed and photographed using a laser confocal microscope (CLSM) to obtain red and green fluorescence intensities. Antibacterial rate = red fluorescence intensity / (red fluorescence intensity + green fluorescence intensity) x 100%.

[0032] Measurement of absorbance (OD value) for 3 hours: The mutans streptococci were co-cultured with the toothbrush filaments for 24 hours, the bacterial liquid was sucked off, lightly washed three times with PBS buffer, fresh BHI liquid medium was added, and the culture was continued for 3 hours, and 100μL of the bacterial suspension was taken into a 96-well plate, five parallel wells were placed for each sample, and three parallel samples were placed for each group, and the OD value was read at 630nm wavelength in a microplate reader. The smaller the OD value, the better the antibacterial performance of the toothbrush filaments. The OD values ​​at 0 h, 6 h, 9 h, and 12 h were measured in the same manner using the method described above.

[0033] Example 1 (1) 1 kg of PVDF was weighed out and added to a single-axis melt spinning machine, and the temperature was raised to the melting temperature of PVDF, 175°C, at a heating rate of 10°C / min. After the pellets were completely melted, they were extruded from a spinneret and wound to obtain a yarn with a diameter of 265 μm. The piezoelectric constant of the PVDF was 19 pC / N. (2) The film was then annealed at 120°C for 2 hours. (3) Then, the toothbrush filament was obtained by corona polarization treatment, and the voltage of the corona polarization treatment was 35 kV, the distance was 35 mm, the temperature was 25°C, and the time was 30 min.

[0034] Examples 2 to 11 The same as in Example 1 was used except that the relevant manufacturing parameters were adjusted according to Table 1. Among them, the mass ratio of polyvinylidene fluoride to trifluoroethylene in the polyvinylidene fluoride-trifluoroethylene copolymer was 3:1, and the mass ratio of polyvinylidene fluoride to hexafluoropropylene in the polyvinylidene fluoride-hexafluoropropylene copolymer was 3:1. The piezoelectric constants of the polyvinylidene fluoride-trifluoroethylene copolymer and the polyvinylidene fluoride-hexafluoropropylene copolymer were 26 pC / N and 28 pC / N, respectively. The diameter of the yarn can be adjusted to the diameter shown in Table 1 by adjusting the specifications of the spinneret.

[0035] Example 12 (1) 1 kg of PVDF was weighed out and added to a single-axis melt spinning machine, and the temperature was raised to the melting temperature of PVDF, 175°C, at a heating rate of 10°C / min. After the pellets were completely melted, they were extruded from a spinneret and wound to obtain a yarn with a diameter of 265 μm. The piezoelectric constant of the PVDF was 19 pC / N. (2) Then, the toothbrush filament was obtained by corona polarization treatment, and the voltage of the corona polarization treatment was 35 kV, the distance was 35 mm, the temperature was 25°C, and the time was 30 min. (3) Then, the film was annealed at 120°C for 2 hours.

[0036] Example 13 The same as in Example 12, except that the relevant production parameters were adjusted according to Table 1.

[0037] Comparative Examples 1 to 5 Except for adjusting the relevant production parameters according to Table 1, the same as in Example 1 was carried out. Among them, the weight average molecular weight of nylon was 15,000.

[0038] The manufacturing parameters for each of the examples and comparative examples are shown in Table 1, and the performance data are shown in Table 2. [Table 1]

[0039] [Table 2]

[0040] 1, it is clear from Examples 1 to 13 and Comparative Examples 1 and 2 that the toothbrush filaments manufactured using the manufacturing method of the present application have good piezoelectric performance and mechanical strength, and after annealing, the bending recovery rate of the monofilament of the toothbrush filament consistently meets the Chinese national standard and has relatively good stability, and after annealing and polarization, the antibacterial performance of the toothbrush filament is improved, and in particular, the antibacterial performance of the toothbrush filament in the Examples of the present application is significantly improved compared to the toothbrush filament made of a general-purpose nylon material in the prior art (Comparative Example 2). This is because the piezoelectric constant and β-phase crystallinity of PVDF are increased by annealing and polarization, and the electrical performance is improved, thereby enhancing the antibacterial performance of the toothbrush filament. Specifically, as shown in FIG. 2, the filaments of the toothbrushes of Examples 1, 2, 12 and 13 have piezoelectric constants of 0.92 pC / N, 0.46 pC / N, 0.85 pC / N and 0.45 pC / N, respectively, in a stationary state, and 3h OD values ​​of 0.0476, 0.0500, 0.0489 and 0.0520, respectively, whereas the filaments of the toothbrushes of Comparative Examples 1 and 2 have piezoelectric constants d 33The piezoelectric constants d of the filaments of the toothbrushes of the present invention were 0.19 pC / N and 0 pC / N, respectively, and the 3h OD values ​​were 0.0673 and 0.2320, respectively. 33 1, when subjected to an external force (corresponding to tooth brushing), the toothbrush filaments of Examples 1, 2, 12 and 13 had output voltages of 1.27V, 0.89V, 1.17V and 0.79V, respectively, and antibacterial rates of 77.3%, 52.8%, 77.1% and 52.7%, whereas Comparative Example 2 had no voltage output and an antibacterial rate of only 9.2%, demonstrating that the toothbrush filaments manufactured using the manufacturing method of the present application have stable voltage output when subjected to a dynamic external force, and have good antibacterial performance.

[0041] As can be seen from Table 2, the elastic modulus of the toothbrush filament in the examples was slightly decreased after annealing and corona polarization treatment using the manufacturing method of the present application, which may be due to a change in the crystal type of the piezoelectric polymer due to high temperature treatment. The elastic modulus is related to the chemical components and lattice structure of the material, and specifically, as shown in Figure 10, the inventors speculate that the α type in the PVDF of Examples 1 and 2 was almost melted by annealing and corona polarization treatment, and there were not enough crystal nuclei to form α type, and at the same time, β type with high crystallinity and high orientation was generated in Examples 1 and 2, and the proportion of β type was higher than that of Comparative Example 1, and there was no β type in Comparative Example 2, and α type was present in Examples 12 and 13, but the proportion of β type was higher than that of Comparative Example 1. Therefore, it was found that the piezoelectric performance of the toothbrush filament was improved after annealing and corona polarization treatment using the manufacturing method of the present application, but the elastic modulus was slightly decreased mainly due to the change in crystal type. In Table 2, the elastic modulus of the toothbrush filaments after annealing decreased, but was still higher than that of the nylon material of Comparative Example 2. At the same time, the toothbrush filaments in the examples of the present application are made into bristle bundles, all of which have a tension of 15 N or more and a bending force of less than 6 N, which are soft bristles as specified in the Chinese national standard GB 19342-2013, meet the requirements of the Chinese national standard, and also meet the recommended standards of clinicians.

[0042] Referring to Table 2, it can be seen from Examples 1 to 13 and Comparative Examples 3 to 5 that when the parameters of the annealing treatment and polarization treatment are within the range of the present application, the obtained toothbrush filaments have better antibacterial performance, as well as good monofilament bending recovery rate, tensile strength, elastic modulus, bristle bundle tension and bristle bundle bending force, and meet the requirements of the Chinese national standard GB 19342-2013.

[0043] Referring to Table 2, it can be seen from Examples 1, 10 and 11 that the toothbrush filaments manufactured using the piezoelectric polymer of the present application have good antibacterial performance, as well as good monofilament bending recovery, tensile strength, elastic modulus, bristle bundle tension and bristle bundle bending force, and meet the requirements of the Chinese national standard GB 19342-2013.

[0044] Specifically, referring to Table 2 and Figure 3, in the antibacterial performance measurement, the higher the OD value of the culture solution, the faster the growth of mutans streptococci and the higher the concentration per unit volume, and further, the poorer the antibacterial performance of the toothbrush filament. As shown in Table 2, in the antibacterial performance measurement, the toothbrush filaments of Examples 1 to 13 all had lower OD values ​​of the culture solution after 3 hours of culture with mutans streptococci than those of Comparative Examples 1 to 5, and as shown in Figure 3, after 6 hours, 9 hours, and 12 hours of culture, the OD values ​​of the culture solutions in the Examples were still lower than those of the Comparative Examples. This shows that the toothbrush filaments manufactured using the manufacturing method of the present application have good antibacterial performance.

[0045] Specifically, as shown in Figures 4a to 9b, the toothbrush filaments of Examples 1, 2, 12, 13, Comparative Examples 1 and 2 were each co-cultured with Mutans streptococci for 24 hours, and then, as shown in Figures 4a, 4b, 6a and 6b, there was almost no attachment (i.e., Mutans streptococci) on the surface of the toothbrush filaments of Examples 1 and 12.

[0046] While there are very small amounts of mutans streptococci on the surfaces of the toothbrush filaments of Example 2 (shown in area A of FIG. 5b) and Example 13 (shown in area E of FIG. 7b), there are large amounts of mutans streptococci on the surfaces of the toothbrush filaments of Comparative Example 1 and Comparative Example 2 at the same magnification (shown in areas B and C of FIG. 8b and area D of FIG. 9b), and in particular, as shown in FIG. 9b, the surface of the toothbrush filament of Comparative Example 2 is almost covered with mutans streptococci. From this, it was found that the toothbrush filament manufactured using the manufacturing method of the present application can effectively reduce the growth or proliferation of bacteria on its surface, and in particular, compared with the toothbrush filament made of a general-purpose nylon material in the prior art, the problem of the mass proliferation of bacteria on its surface is significantly improved. At the same time, when the toothbrush filament of the present application is applied to a toothbrush, the piezoelectric response of the toothbrush filament during the cleaning process can also effectively remove bacteria on the tooth surface, which contributes to the improvement of dental diseases such as tooth spot bacteria or periodontal disease.

[0047] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited thereby. Any modifications, equivalent replacements, improvements, etc. made in accordance with the spirit and principles of the present invention are all included in the scope of the present invention.

Claims

1. (1) adding a polyvinylidene fluoride piezoelectric polymer having a weight average molecular weight of 150,000 to 300,000 to a melt spinning machine, heating the polymer to its melting temperature, and extruding the polymer to obtain a yarn having a diameter of 175 μm to 265 μm, wherein the piezoelectric polymer has a piezoelectric constant of 10 pC / N to 32 pC / N; (2) Annealing the yarn at 120°C for 1.5h to 3h, and then subjecting it to corona polarization to obtain toothbrush filaments, wherein the corona polarization voltage is 10kV to 50kV, the distance between the electrode and the sample is 10mm to 50mm, the polarization temperature is 25°C to 50°C, and the time is 10min to 60min; or (2') subjecting the thread to corona polarization treatment and then annealing it at 120°C for 1.5h to 3h to obtain toothbrush filaments, the corona polarization treatment being at a voltage of 10kV to 50kV, a distance of 10mm to 50mm, a temperature of 25°C to 50°C, and a time of 10min to 60min; Including, The filament of the toothbrush generates a voltage of 0.6V to 1.5V when subjected to an external force; The toothbrush filament has a monofilament bending recovery rate of 60% to 80%; The antibacterial rate of the toothbrush filaments is 45% to 80%; The method for manufacturing a toothbrush filament, wherein the toothbrush filament has a piezoelectric constant of 0.4 pC / N or more in a stationary state.

2. A toothbrush filament manufactured by the manufacturing method of claim 1.

3. A toothbrush comprising the toothbrush filament of claim 2.

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