JP2002325635A - Toothbrush - Google Patents

Abstract

(57) [Summary] [Problem] Even with continued use, the opening of hair tips is small,
To provide an economical toothbrush whose usability is not easily reduced. SOLUTION: In differential scanning calorimetry (DSC), 1
It has two or more endothermic peaks in the temperature range of 95 to 230 ° C., the endothermic energy per mg for the entire endothermic peak in the temperature range is 20 to 80 mJ / mg, and the endothermic peak energy per mg among the endothermic peaks There select next largest peak with the largest peak, the low-temperature side first endothermic peak P _1, when the high temperature side and a second endothermic peak P _2, first to the first heat absorbing energy per 1mg of endothermic peak P ₁ 2 Endothermic peak P ₂ 1
A polyamide fiber having an endothermic energy ratio per mg in the range of 0.8 to 6.0 is planted. The ratio of the endothermic energy per 1mg of the first endothermic peak _{P 1} for the endothermic energy per 1mg of the whole endothermic peak implanting a polyamide-based fiber is in the range of 0.08 to 0.6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothbrush having a small brush opening even with continued use.

[0002]

2. Description of the Related Art As bristles (filaments) for toothbrushes, synthetic fibers such as polyamide fibers and polybutylene terephthalate (PBT) have excellent physical properties such as abrasion resistance, chemical resistance and bending recovery. It is widely used because of its excellent usability and productivity. In addition, natural hair such as pig hair is also used in part.

Further, as a toothbrush in which the physical properties of hair are specified by differential scanning calorimetry (DSC), a toothbrush disclosed in Japanese Patent Application Laid-Open No. Hei 10-201539 proposed by the present applicant is known.

[0004]

Generally, when a toothbrush is used for a long period of time, as the use time increases, the bristle tips gradually open and the usability deteriorates, and the gums are easily damaged. For this reason, from the viewpoints of both usability and economy, there is a demand for a toothbrush whose hair tips are as hard to open as possible. In the case of the toothbrush described in the above publication proposed by the present applicant, the purpose is to improve the plaque removing power, and the durability such as the opening of the hair tips has not been sufficiently studied. Differential scanning calorimetry (DS) of toothbrush bristles
Although there is a reference cited in C), no sufficient study has been made on the endothermic properties of the hair and the opening of the hair tips.

The present invention specifies a range of endothermic characteristics suitable for minimizing the opening of the hair tips by conducting further experiments and studies on the endothermic characteristics of the hair in differential scanning calorimetry. It is an object of the present invention to provide an economical toothbrush in which the opening of the bristle is small even when the continuation is continued, and the usability is hardly reduced.

[0006]

Means for Solving the Problems To solve the above problems,
Therefore, the present invention employs the following means. That is,
The toothbrush according to claim 1, wherein the differential scanning calorimetry (DSC) is used.
Endothermic peak in the temperature range of 195 to 230 ° C.
Or more, for the entire endothermic peak in the temperature range.
Endothermic energy per 1mg is 20-80mJ / m
g, preferably 30 to 70 mJ / mg.
Endothermic peak energy per mg
Select the largest peak and the next largest peak,
Is the first endothermic peak P₁The second endothermic peak P on the high temperature side
₂, The first endothermic peak P₁Per 1mg of
Endothermic Peak P for Endothermic Energy of P₂ 1mg of
The ratio of endothermic energy per unit is 0.8 to 6.0, preferably
Or polyamide fibers in the range of 0.9 to 5.5.
It is characterized by having been established.

The polyamide fiber having the above physical properties is:
The degree of crystallinity of the bristles is sufficiently high, the rigidity and the resilience to bending are good, and the bristles for bristles have appropriate crystal size and degree of stretch orientation and are preferable. Therefore, the toothbrush in which the toothbrush is implanted has a small opening of the brush even when the brush is continued to be used, and the usability is not easily reduced. For this reason, the durability is high, and the toothbrush is economical and of good quality.

[0008] Incidentally, when the ratio is less than 0.8 (the first ratio of the endothermic peak P ₁ increases), stretch orientation degree is small, since crystallization size is small, rigidity of the use hair becomes low, Further, when the ratio is greater than 6.0 (the first ratio of the endothermic peak P ₁ is small), stretch orientation degree is large, crystallization size also increases, although rigidity of the use hair increases, to flexion It is not preferable because the recoverability decreases.

[0009] The toothbrush according to the second aspect is a differential running brush.
Temperature between 195 and 230 ° C. in calorimetry (DSC)
Having two or more endothermic peaks in the range,
The endothermic energy per mg for the entire peak is
20-80 mJ / mg, preferably 30-70 mJ / m
g, the endothermic peak per mg of the endothermic peak
The peak with the highest peak energy and the next largest peak
And the low-temperature side as the first endothermic peak P₁, High temperature side
To the second endothermic peak P₂And the endothermic peak
Number of endothermic energies per mg for the body
1 Endothermic peak P ₁Endothermic energy per 1mg
Energy ratio of 0.08 to 0.6, preferably 0.09 to
The fact that the polyamide fiber in the range of 0.5 was planted
Features.

[0010] When using the polyamide-based fiber having the above physical property values, of the crystallization of the whole use hair, the ratio of slightly lower portion of the orientation degree and the crystal size corresponding to the first endothermic peak P ₁ on the low temperature side appropriate And a toothbrush having excellent rigidity and bristle durability can be obtained.

The entire endothermic peak and the first endothermic peak P
₁And the second endothermic peak P₂Claims wherein the relationship of
So as to simultaneously satisfy the relationship of the inventions described in 1 and 2 above.
If so, the physical properties of the polyamide fiber can be controlled more reliably,
Further, a toothbrush of good quality can be obtained. Ma
The first endothermic peak P₁And the second endothermic peak P
₂Are all present at 212 ° C. or higher,
It becomes more preferable.

[0012]

Embodiments of the present invention will be described below. The bristles used in the toothbrush of the present invention are polyamide fibers. As the polyamide-based fiber, those obtained by condensation polymerization of a dicarboxylic acid and a diamine, those obtained by ring-opening polymerization of a cyclic lactam, those obtained by polycondensation of an ω-aminocarboxylic acid, and the like are used. Further, an aromatic diamine or dicarboxylic acid may be used. For example, nylon 6, nylon 7, nylon 11, nylon 12, nylon 6-6, nylon 4-6, nylon 6
-10, nylon 6-12, nylon 6T, MDX6 and the like, and composite filaments obtained by combining these can be used. Stiffness, recovery, the balance between water absorption and feel, but nylon 6-12 or nylon 6-10 are preferred, and the first endothermic peak _{P 1} and a second endothermic peak _{P 2} is more than both 212 ° C. Nylon 6 10 is more preferred.

The polyamide fiber may be spun by a commonly used method. The polyamide resin to be used is melted or dissolved in a solvent so as to be in a fluid state, and the polyamide resin is fed into a gas or liquid through pores of a spinneret. It is preferable to extrude the resin into the material, cool and solidify the material to form a fiber.

The hair used in the present invention is the above-mentioned polyamide-based hair.
In fiber, 1 in differential scanning calorimetry (DSC)
Two or more endothermic peaks in the temperature range of 95 to 230 ° C
1 mg of the entire endothermic peak in the temperature range.
Endothermic energy of 20-80 mJ / mg,
 Endothermic peak energy per 1 mg of the endothermic peak
Select the peak with the highest energy and the peak with the next
And the low-temperature side as the first endothermic peak P₁, Hot side second
Endothermic peak P₂, The first endothermic peak P₁ Of 1
Second endothermic peak P for endothermic energy per mg
₂The ratio of endothermic energy per mg of
6.0, and the entire endothermic peak
Endotherm to endothermic energy per mg
Peak P₁Of endothermic energy per 1mg
Is in the range of 0.08 to 0.6.

[0015] When the polyamide fiber having such physical properties is used as bristles and is implanted on the implanted surface of the toothbrush handle, the resilience to bending is good, the opening of the brush is small even with continued use, and even over time. It becomes a toothbrush whose usability is hardly reduced. Also, among the crystallization of the whole use hair, the ratio of slightly lower portion of the orientation degree and the crystal size corresponding to the first endothermic peak P ₁ on the low temperature side can be properly controlled, rigidity and Yoke excellent durability toothbrush It can be.

The differential scanning calorimetry (DSC) employed in the present invention can be measured without using a special structure fixing method or atmosphere. The rate of temperature rise shall be measured at 1 ° C / min. In addition, in determining the endothermic energy per 1 mg of the first and second endothermic peaks, an auxiliary line which is in contact with the DSC curve or which divides the overlapping portion of the peaks is drawn, and the calculation is made from the area enclosed by them. In addition, when there are a plurality of endothermic peaks, in determining the endothermic energy per mg of the entire endothermic peak, the DSC at the lowest temperature side and the highest temperature side of the auxiliary line drawn at the first and second endothermic peaks is used. Draw an auxiliary line connecting the points that touch the curve, and calculate from the area enclosed by them.

[0017] As one means for setting the first ratio of the endothermic peak P ₁ of the low temperature side, the heat treatment is preferred. The heat treatment is performed at a temperature of about 30 to 150 ° C. If the heat treatment temperature is increased, the heat treatment time is shortened, but the heat treatment is preferably performed for at least 2 minutes or more.
When the temperature is low, for example, the temperature is maintained at 50 ° C. for 2 weeks or at 40 ° C. for 1 month.

[0018] By performing the heat treatment as described above, along with the stabilization of use hair whole crystal can be achieved, the ratio of slightly lower portion of the orientation degree and the crystal size to the first endothermic peak P ₁ on the low temperature side properly The toothbrush can be controlled and has good rigidity and bristle durability.

The thickness (fiber thickness) of the hair as a brush is
It is preferably 3 to 12 mils (0.076 to 0.305 mm), preferably 5 to 11 mils (0.127 to 0.279 mm), and usually a rounded tip.

The implanted hair usually has the same diameter within one hair except for the rounded portion of the hair tip. It may be in the form of a tapered hair whose diameter gradually decreases as going toward. Further, the shape of the brush tip may be processed into a spatula shape, a scraper shape, a spherical shape, or the like.

The cross-sectional shape of the hair is usually circular,
The shape may be a triangle, a quadrangle, a hexagon, a non-uniform polygon, a star, a circle, or a combination of straight lines and curves. In addition, coloring with a pigment or a dye may be transparent (natural), transparent-colored, opaque-colored (including white), or two or more of these may be performed in hair bundle units or 1-color.
It may be used in combination in one hair bundle. Further, the cross section of the same hair may have a multi-core sheath structure or may be partially combined with a different material or colored material. Furthermore, as long as the properties of the hair are not impaired, stabilizers against heat and light,
A filler, a surface lubricant, an antistatic agent, a germicidal material (antibacterial material) and the like may be appropriately compounded or applied.

The angle of the brush to be implanted is not necessarily perpendicular to the head implantation surface, but the brush may be inclined in a specific direction to enhance the scraping effect.

The cross-sectional shape of the hair bundle is usually circular and arranged in a lattice shape, but it is not necessarily required to be circular, and a polygonal cross-section such as a triangle or a square may be used in accordance with the specifications of the flocked portion.
It may be a straight line, a curve, or an irregular cross-section combining these.

The brushes constituting the hair bundle need not all have the same brush diameter, for example, 6 mils (0.152 m).
m) and 7 mils (0.177 mm), 6 mils and 8 mils (0.203 mm),
They can be appropriately selected and combined in consideration of the cleaning effect and the like. Further, a material having a different brush material may be combined, or may be combined with a rubber-like brush or chip such as silicon or an elastomer.

[0025] As a flocking method, a bristle bundle is folded into two pieces using a small piece of metal or plastic called a flat wire, and the bristle is planted. One end of the bristle bundle is melt-bonded by means of heat or the like. In-mold flocking to fill and fix the resin in the mold with the part facing the mold, heat fusion flocking to fuse and fix one end of the hair bundle and the head part flocking surface by heat, etc. Known methods can be used.

The material of the toothbrush handle including the head portion is made of thermoplastic resin and has a flexural modulus of 500 to 3000.
MPa (JIS K7203) is preferred, and polyolefins (polypropylene, polyethylene, etc.), polyesters (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonates (including blends with polyesters), polyarylates (including blends with polyesters), Polyoxymethylene, AS
Resin, ABS resin, cellulose propionate, polyamide, polyurethane, PMMA resin, and the like can be used. Polyester and polypropylene are preferred in terms of cost and workability.

Further, these resins may be combined with each other, a thermoplastic elastomer (olefin type, styrene type, urethane type, nylon type, etc.), a silicone resin or the like to form a multicolor molded handle. It is also preferable that the head portion is made of two or more materials having different elastic moduli, and a part or all of the handle has flexibility.

[0028]

EXAMPLE Nylon 6-10 and nylon 6-12 pellets each were dried under a nitrogen stream at 50 ° C. for 24 hours, melted at 250 to 300 ° C., extruded from a die into a water tank, and wound with a roller. Taking, stretching while cooling and heating with water and steam so that the hair diameter of one hair finally becomes 8 mil (0.203 mm),
Oil finishing, large diameter drum, about 50m in diameter
m hair bundles were wound up. This was cut into a plurality of portions, held in a linear state, and heat-treated at 50 ° C. for 2 weeks. Cover the hair bundle for polyamide with paper,
The hair was dried under warm air at 30 to 50 ° C. to prepare hair for nylon 6-10 and nylon 6-12, respectively. Further, hairs of nylon 6-10 and nylon 6-12 were prepared in the same manner except that the heat treatment was not performed.

A hair bundle having a length of about 33 mm was cut out from each of the hairs according to a standard method, and the hairs were planted on a polypropylene toothbrush handle by a Tsujimura-type hair transplanter. Flocked part of this toothbrush handle (head flocked surface)
Has 23 non-inclined flocking holes with a circular cross section of 1.6 mm in diameter and 3.8 mm in depth. These flocking holes are regularly arranged in three rows except for two holes at the tip. It is arranged in a shape. After implanting the hairs into these flocked holes while folding the 8-mil bristles into two pieces with a flat brass wire having a length of 2.1 mm, an average of 18 bristles per hole was used. ) Was 9.5 mm, the tip of the tip was cut into a flat shape, and the tip was rounded.

(Influence test of DSC by heat treatment) Each of the four types of hair prepared above was finely cut,
Differential scanning calorimetry (DSC) was performed. The results are shown in FIGS. The measurement conditions are as follows. Differential scanning calorimeter: DSC-22C (manufactured by Seiko Instruments Inc.) DISK STATION: SSC5100 Plotter: SP530 Sample amount: 10 mg Reference: alumina 10 mg Heating rate: 1 ° C./min Measurement scanning temperature range: 150 to 300 ° C.

FIG. 1 shows a case without heat treatment of nylon 6-12, and FIG. 2 shows a case with heat treatment of nylon 6-12.
FIG. 4 shows the measurement results without heat treatment of nylon 6-10, and FIG. 4 shows the measurement results with heat treatment of nylon 6-10.

The endothermic energies for each endothermic peak determined according to the auxiliary line (dotted line) in each figure based on the measurement results in FIGS. 1 to 4 are as shown in Table 1.

[0033]

[Table 1]

As shown in Table 1, in the case of nylon 6-12 without heat treatment, there was only one endothermic peak P, the peak temperature was 214.7 ° C., and the endothermic energy was 44.5 mJ / m.
g. Also, in the case of nylon 6-12 Yes heat treatment, the first peak temperature 211.2 ° C. endothermic peak _{P 1,}
Endothermic energy 6.8mJ / mg, the second peak temperature 218.1 ° C. endothermic peak _{P 2,} the endothermic energy 31.9mJ / mg, the total peak endothermic energy 5
5.2 mJ / mg, second peak / first peak = 4.6
9, 1st peak / total peak = 0.12.

In the case of nylon 6-10 without heat treatment, the first peak temperature 216.6 ° C. endothermic peak _{P 1,} the endothermic energy 3.5 mJ / mg, the second endothermic peak _{P 2}
Of 222.3 ° C. and its endothermic energy
4 mJ / mg, endothermic energy of the entire peak 48.2 m
J / mg, second peak / first peak = 6.69, first peak / overall peak = 0.07. Also, in the case of nylon 6-10 Yes heat treatment, the first peak temperature 216.0 ° C. endothermic peak _{P 1,} the endothermic energy 21.6
mJ / mg, the second endothermic peak _{P 2} peak temperature 22
1.6 ° C., its endothermic energy was 27.5 mJ / mg, the endothermic energy of the entire peak was 58.9 mJ / mg, the second peak / first peak = 1.27, and the first peak / whole peak = 0.37. .

(Bristle opening test) Using the four types of toothbrushes prepared using the four types of bristles, applying a load of 3 [N] and continuously cleaning the surface of the uneven metal plate in warm water at 35 ° C. And
Regarding the degree of hair tip spread, the difference from the initial state before brushing was measured, and the ratio of the initial state to the hair tip spread width was determined. Table 2 shows the results.

[0037]

[Table 2]

As is clear from Table 2, a statistically significant difference was observed in the bristle tip spreading ratio depending on the presence or absence of heat treatment under any of the conditions of 5,000 times of brushing and 10,000 times of brushing. It was confirmed that the hair that had been subjected to the heat treatment had a smaller hair tip spreading ratio and had higher hair durability.

[0039]

As described above, according to the present invention,
It is possible to provide an economical toothbrush with little opening of the bristle tip even with continued use, and in which the usability is hardly reduced. In addition, in the crystallization of the whole hair, the orientation degree corresponding to the first endothermic peak on the low temperature side and the ratio of the slightly lower portion of the crystal size can be appropriately controlled, so that the toothbrush is excellent in rigidity and hair durability. be able to.

[Brief description of the drawings]

FIG. 1 is a graph showing the results of differential scanning calorimetry of nylon 6-12 without heat treatment.

FIG. 2 is a graph showing the results of differential scanning calorimetry of nylon 6-12 with heat treatment.

FIG. 3 is a graph showing the results of differential scanning calorimetry of nylon 6-10 without heat treatment.

FIG. 4 is a graph showing the results of differential scanning calorimetry of nylon 6-10 with heat treatment.

[Explanation of symbols]

P ₁ First endothermic peak on low temperature side P ₂ Second endothermic peak on high temperature side

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Kato 1-37 Honjo, Sumida-ku, Tokyo F-term in Lion Corporation (reference) 3B202 AA06 EA01

Claims (2)

[Claims] 1. The method according to claim 1, wherein the differential scanning calorimetry measures 195 to 23.
Having two or more endothermic peaks in a temperature range of 0 ° C .;
Endothermic energy per mg for the entire endothermic peak
Energy of 20 to 80 mJ / mg,
Endothermic peak energy per mg
The largest peak and the next largest peak,
To the first endothermic peak (P₁), Second endothermic peak on high temperature side
(P₂ ), The first endothermic peak (P₁) 1m
second endothermic peak (P
₂) Of 0.8 to 0.8%
That the polyamide fibers in the range of 6.0 were planted.
Characteristic toothbrush. 2. 195 to 23 in differential scanning calorimetry.
It has two or more endothermic peaks in a temperature range of 0 ° C., the endothermic energy per mg for the entire endothermic peak in the above temperature range is 20 to 80 mJ / mg, and the endothermic peak energy per mg in the endothermic peaks Is selected as the first endothermic peak (P ₁ ) on the low-temperature side and the second endothermic peak (P ₂ ) on the high-temperature side.
toothbrush ratio of endothermic energy per 1mg of the first endothermic peak (P ₁₎ is characterized in that planted the polyamide fibers in the range of 0.08 to 0.6 relative to the endothermic energy per mg.