Polyketone Bristles And Toothbrush Comprising The Bristles

Abstract

Provided are polyketone toothbrush bristles and a toothbrush comprising the same. The toothbrush bristles are made using a polyketone material having high rigidity, high elasticity and excellent wear resistance and thus shows reduced bristle gap-widening and increased service life. The toothbrush bristles obtained by using the polyketone according to the present disclosure have excellent elasticity and are suitable for removal of plaque on the severely indented tooth surfaces. Particularly, in the case of fine bristles, it is possible to remove interdental plaque, which, otherwise cannot be removed well by the conventional toothbrushes.

Claims

1. Toothbrush bristles comprising polyketone.

2. The toothbrush bristles according to claim 1, wherein the polyketone has a basic structure comprising carbon monoxide and olefin.

3. The toothbrush bristles according to claim 1, wherein the polyketone is a hybrid polymer of carbon monoxide with ethylene or a terpolymer of carbon monoxide, ethylene and polyketone.

4. The toothbrush bristles according to claim 1, wherein the polyketone is represented by the following chemical formula:
CH.sub.2CH.sub.2C(O).sub.XCH.sub.2CH(CH.sub.3)C(O).sub.Y wherein x:y is 1:10-10:1.

5. The toothbrush bristles according to claim 1, which consists of polyketone.

6. The toothbrush bristles according to claim 1, further comprising at least one water-insoluble polymer material selected from the group consisting of polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyurethane and nylon.

7. The toothbrush bristles according to claim 1, further comprising at least one selected from the group consisting of an anti-inflammatory and anti-bacterial agent, whitening agent, sensitive tooth-alleviating agent, anti-plaque agent, fragrance, bad breath-preventing agent, gingiva health-aid, tooth decay-preventing agent, oral cavity cleaner, xylitol, bamboo salt, bay salt, prepared salt, refined salt, pine salt, steamed salt, molten salt, processed salt and phosphate salt.

8. The toothbrush bristles according to claim 1, which are fine bristles having a needle-like shape at the end thereof.

9. The toothbrush bristles according to claim 1, which have a diameter of 0.1 mm-0.13 mm.

10. A toothbrush comprising the toothbrush bristles as defined in claim 1.

Description

DESCRIPTION OF DRAWINGS

[0051] FIG. 1 is a graph illustrating the plaque removal rate between teeth as a function of diameter of toothbrush bristles.

[0052] FIG. 2 shows polyketone toothbrush bristles and nylon toothbrush bristles right after brushing.

BEST MODE

[0053] Hereinafter, the present disclosure will be explained in detail with reference to Examples. The following examples are for illustrative purposes only and it is apparent to those skilled in the art that the scope of the present disclosure is not limited thereto.

Examples

1. Comparison of Physical Properties for Polyketone, Nylon and PBT

[0054] Each of Nylon 612 (Dupont, Tynex), polybutylene terephthalate (PBT) (KOLON) or polyketone (Hyosung, M310U and similar grade of M310U), as powder of resin material used for toothbrush bristles, was heated and extrusion molded through a nozzle of extruder, followed by cooling and drying with hot air. Then, toothbrush bristles having a diameter of 0.18 mm were produced by using each material.

[0055] (1) Tensile Strength After producing toothbrush bristles, tensile strength as the force upon the cutting of bristles, by which the rigidity of one strand of bristle could be evaluated, was determined. Then, evaluation was carried out by comparing the tensile strength of polyketone with that of the conventional material for toothbrush bristles, Nylon 612 or PBT.

[0056] Particularly, according to the standard test method of ASTM D638, both ends of one strand of toothbrush bristle were fixed by a fixing member and the strand was drawn along the axis of the specimen. Then, the force upon the cutting, i.e. tensile strength, was determined.

[0057] (2) Elasticity Loss

[0058] In addition, to determine the durability of polyketone, polyketone toothbrush bristles were planted to a toothbrush head to obtain a toothbrush. Then, the toothbrush was compared with toothbrushes using Nylon 612 and PBT in terms of elasticity loss.

[0059] The elasticity loss indicates durability (bristle gap-widening) during the use of a toothbrush. After carrying out reciprocating brushing 5000 times or 10000 times by using a brush machine, the gap-widening was determined according to the following mathematical Formula 1. As the value of elasticity loss is decreased, the difference of a gap in the bristles between before and after brushing is reduced, suggesting that the toothbrush bristles show lower gap-widening.

Elasticity loss (%)=(BA)100[Mathematical Formula 1]

[0060] A: gap in the bristles before brushing

[0061] B: gap in the bristles after brushing

[0062] (3) Test Results

[0063] The following Table 1 shows the results of tensile strength (Kgf) and elasticity loss (%) of each type of toothbrush bristle.

TABLE-US-00001 TABLE 1 Item Polyketone Nylon 612 PBT Bristle Tensile 1.76 0.03 0.87 0.05 1.56 0.06 character- strength (kgf) istics Toothbrush Elasticity loss 6.23 9.49 8.51 character- (%) istics Brushing 5,000 times Elasticity loss 13.43 19.4 15.3 (%) Brushing 10,000 times

[0064] After the test, polyketone toothbrush bristles show a tensile strength (kgf) 2.0 times higher than the tensile strength of nylon and 1.13 times higher than that of PBT (Table 1), which demonstrates that polyketone maintains high rigidity when it is applied to toothbrush bristles.

[0065] In addition, after carrying out reciprocating brushing 5,000 times, the toothbrush using polyketone toothbrush bristles shows an elasticity loss 34% and 27% lower than the elasticity loss of Nylon 612 and that of PBT, respectively. This suggests that polyketone shows lower gap-widening by 34% and 27% as compared to Nylon 612 and PBT, respectively. Similarly, after carrying out reciprocating rushing 10,000 times, polyketone shows lower gap-widening by 31% and 12% as compared to Nylon 612 and PBT, respectively.

2. Determination of Gingiva Irritation for Polyketone, PBT and PES

[0066] Polymers having high rigidity and excellent wear resistance, like polyketone, include fluoro-resin (PTFE, PVDF), POM, PBT, PES, or the like. However, in the case of fluoro-resin, it is difficult to manufacture toothbrush bristles due to its high melting point. In the case of POM, it is not suitable for toothbrush bristles due to its brittleness. PBT and PES are materials having sufficiently high rigidity and excellent wear resistance, like polyketone. Thus, toothbrush bristles having a diameter of 0.18 mm were produced by using them in the same manner as the above-described example. Herein, the end portions of bristles were planted without any separated processing for fine bristles to obtain toothbrush bristles. Then, the toothbrush bristles using three types of materials were evaluated by professional panels through a survey about gingiva irritation.

[0067] The survey was carried out by allowing 20- to 40-aged 20 females and 20 males to use test toothbrush for 7 days and then comparing the test toothbrush with one another. Before using a new toothbrush, the panels were allowed to have a quiescence of 3 days and to care their teeth as usual during the quiescence. The survey results are shown in the following Table 2 (multiple choices allowed).

TABLE-US-00002 TABLE 2 No pain on gingiva Pain on gingiva Bleeding during during brushing during brushing brushing PBT 21 persons 19 persons 4 persons PES 13 persons 27 persons 5 persons Polyketone 35 persons 5 persons 0

[0068] After the test, it can be seen that while polyketone causes little irritation on the gingiva and thus is suitable as a material for toothbrush bristles, PBT and PES cause high gingiva irritation and thus are not suitable for toothbrush bristles.

3. Functional Evaluation of Polyketone and Nylon

[0069] To the same toothbrush pole having 32 holes with a diameter of 1.6 mm, nylon toothbrush bristles and polyketone toothbrush bristles each having a diameter of 5 M (0.127 mm) were planted to provide test toothbrushes. Then, 20- to 40-aged 20 females and 20 males were allowed to use each toothbrush and compared the toothbrushes with each other. Before using a new toothbrush, the panels were allowed to have a quiescence of 3 days and to care their teeth as usual during the quiescence.

[0070] The survey included questions capable of evaluating the elasticity and cleaning effect of each toothbrush and evaluation was carried out in a 5-point scale (higher point means higher satisfaction).

TABLE-US-00003 TABLE 3 Nylon 612 Polyketone The toothbrush bristles are elastic 2.2 3.9 The toothbrush shows high cleaning effect 2.5 4.0 The toothbrush provides a refreshing feel 2.2 3.8 between teeth Food residue between teeth is removed well 2.4 3.9

[0071] After the test, it can be seen that the polyketone bristles show high elasticity to provide a significantly higher effect of cleaning the tooth surface and interdental portion as compared to the nylon bristles.

4. Determination of Effect of Removing Plaque for Toothbrush Bristles Having Different Diameter

[0072] As the bristles applied to a toothbrush have a smaller diameter, a higher interdental cleaning effect is provided. However, in the case of toothbrush bristles having a small diameter, particularly nylon bristles used frequently according to the related art, the bristles are cut easily, have little elasticity and cause gap-widening with ease.

[0073] In this example, to overcome the above-mentioned disadvantages of nylon bristles, polyketone having high rigidity was applied to develop toothbrush bristles having high elasticity and causing little gap-widening despite a small diameter. Toothbrush bristles having a diameter of 10 mils (0.254 mm), 8 mils (0.203 mm), 7 mils (0.178 mm) and 6 mils (0.152 mm) were produced to determine the effect of removing plaque as a function of diameter of bristles.

[0074] Bacterial film coating on the artificial tooth surface was used after the tooth portion of a gnathostatic model was dipped in a colored polymer for about 10 seconds, taken out therefrom, dried in an isothermal-isohumidity chamber (25 C., 55%) maintaining a predetermined temperature and humidity for 60 minutes, and dried completely. Then, the toothbrushes, to which bristles having a diameter of 10 mils, 8 mils, 7 mils and 6 mils were planted, were used so that the section of bristles of the toothbrush and the narrower surface of the coated gnathostatic model were positioned horizontally with each other to cover the surfaces as much as possible during brushing. A pressure of 300 g was applied to all types of toothbrushes and each toothbrush product was subjected to vertical brushing for 30 seconds alternately with horizontal brushing for 30 seconds, 8 times. Then, the area of the artificial tooth surface was measured before and after removing the bacterial film through a microscope and the rate of plaque removal was evaluated as a percent (%) value. The results are shown in FIG. 1.

[0075] After the test, it can be seen that as the diameter of toothbrush bristles is decreased from 10 mils (0.254 mm) to 6 mils (0.152 mm), the interdental plaque removal rate is improved by about 4.5 times or more.

5. Comparison of Physical Properties of Polyketone vs. Nylon

[0076] (1) Tensile Strength

[0077] To evaluate the force upon cutting of one strand of toothbrush bristle, the top end/bottom end of one strand of toothbrush bristle were gripped to a universal test machine (UTM) with an interval of 1 cm and the top end was drawn at a rate of 200 mm/min to measure the force when the strand was cut.

[0078] (2) Elasticity Loss

[0079] To evaluate how much toothbrush bristles cause gap-widening, a toothbrush was tested with a brushing evaluation machine by measuring the gap-widening width after brushing 5,000 times. Each of polyketone bristle and nylon bristle was photographed right after brushing. The results are shown in FIG. 2.

[0080] (3) Elasticity

[0081] To evaluate elasticity (softness) of toothbrush bristles, one strand of toothbrush bristle was hang on a wire, which allows measurement of applied force at the point corresponding to of the strand, and the force was measured.

[0082] (4) Test Results

[0083] The test results for tensile strength, elasticity loss and elasticity are shown in the following Table 4.

TABLE-US-00004 TABLE 4 Poly- Results Item ketone Nylon612 vs. nylon Tensile Tensile strength (kgf) 0.56 0.56 40% strength 0.034 0.034 increased (bristle diameter: 0.102 mm) Toothbrush Elasticity Right 23.0% 39.50% 42% character- loss (%) after improved istics (brushing brushing (bristle 5,000 After 6.1% 11.90% 48.7% diameter: times) complete improved 0.127 mm) drying Bristle elasticity (cN) 0.56 0.56 40% 0.034 0.034 increased

[0084] As can be seen from Table 4, after evaluating the tensile strength of polyketone bristles and that of nylon (diameter: 0.102 mm (4 mils)), polyketone (0.56 kgf) has a tensile strength improved by 40% as compared to nylon (0.40 kgf).

[0085] After evaluating the elasticity loss of polyketone bristles and that of nylon (diameter: 0.127 mm (5 mils)), it can be seen that polyketone shows an elasticity loss improved by 42% and 48.7% right after brushing and after complete drying, respectively, as compared to nylon (* a smaller value indicates lower gap-widening).

[0086] In addition, after evaluating the elasticity of polyketone bristles and that of nylon (diameter: 0.127 mm (5 mils)), it can be seen that polyketone (224.9 cN) shows elasticity increased by 28.8% as compared to nylon (174.6 cN).