JP2003169718A - Filament and toothbrush using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filament excellent in penetrability into gaps and touch while providing a high cleaning feel, and a toothbrush using it. <P>SOLUTION: An end of the filament 1 is tapered and at least one or more step parts 3 are formed on this taper. The filament 1 is constructed of two or more multi-core structures 2a and 2b made from different resins. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a toothbrush filament and a toothbrush using the same.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 2001-511379 discloses a toothbrush using a coextruded filament of polytrimethylene terephthalate and another polymer material. In the case of this toothbrush, by containing polytrimethylene terephthalate in the bristle material, the bristle has excellent bending recovery strength, and as a result, the fineness of each bristle can be reduced. However, the reduction in diameter is about 10% of the fine diameter, and it is difficult to obtain the interdental penetration, the feeling of cleaning, and the feeling of hitting as much as the taper hair.

In Japanese Unexamined Patent Publication No. 6-141923, both ends are tapered, and 1 mm and 3 m from the tip of the taper.
The brush diameter at each position of m, 5 mm, and 8 mm is 25 to 35%, 55 to 70%, and 80 to 9 with respect to the brush diameter of the base portion.
A toothbrush with 0%, 90-100% synthetic monofilament is shown. However, the taper shape of this bristle is a uniform shape with no step portion and is excellent in interdental penetration, but the feeling of cleaning is slightly insufficient, and the tingling of the tip of the hair may be felt.

Japanese Unexamined Patent Publication No. 9-322821 discloses a toothbrush having branching bristles. The tip branch hair has too much difference in rigidity between the ultrafine hair at the tip and the hair rigidity before branching, and the tip of the hair easily breaks at the branching portion, resulting in poor usability.

Japanese Patent Laid-Open No. 2001-178542 discloses that
A toothbrush using tapered bristles having a multi-layered cross section is shown. This toothbrush can change the color of the inner and outer layers as an indicator function to display the replacement time of the toothbrush, but since the taper shape is a uniform shape with no step only because the hair is colored, the stepped taper Not as sophisticated as hair.

[0006]

As is clear from the above description, the filaments conventionally used have the following problems. (1) In the case of normal hairs that are not tapered, the gap penetration is insufficient, and it is difficult to clean extremely narrow gaps such as pit fissures. (2) In the case of a taper hair having a sharpened hair tip, the contact feeling may be slightly tingling, and some people may feel harmful. (3) When the taper hair has a uniform shape, the feeling of cleaning is slightly insufficient. (4) In the case of a tip bifurcation in which the tip is bifurcated into ultrafine hair,
There is a problem in terms of durability and usability because it easily breaks from the branching part.

[0007]

In order to solve the above-mentioned problems, the filament of the present invention is characterized in that the hair tips have a tapered shape and that the tapered portion has at least one step portion or more. To do. further,
The filament has a multi-core structure of two or more layers made of different resins. By using a filament having such a configuration, it is possible to obtain a filament that is excellent in both the clearance penetration property and the contact feeling and has a high feeling of cleaning.

Further, the toothbrush of the present invention is obtained by implanting the filament having the above-mentioned structure, and is a toothbrush which is excellent in both clearance entry property and contact feeling and has a high feeling of cleaning.

The filament of the present invention is basically a taper hair whose hair diameter becomes smaller toward the tip of the hair. Furthermore, the sharpness of the tapered shape is not uniform as in the past,
It is a filament having a stepped portion where the taper shape changes in the middle, and the taper shape of the tip of the hair is thinner.
The taper with the step portion is formed at both ends or one end of the filament depending on the usage of the filament.

The step portion may have a high dirt cleaning power even if it is a clear step, but the continuous and gentle taper shape is superior in terms of specifications and durability. Further, depending on the purpose of the brush and the bristle manufacturing conditions, a part having a non-tapered cylindrical part may be used. For example, the portion from the root of the hair for use to the middle part may be tapered, and the tip to the tip of the hair may be cylindrical, and the tip may be tapered. Further, the tip of the bristle tip is recessed, and it may be cup-shaped.

As the filament material, PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PTT (polytrimethylene terephthalate), polyamide, polypropylene, polytrimethylene terephthalate, etc. can be used, but in the case of a multi-core structure It is preferable to dispose a polyester resin having a high hydrolysis rate further outside.

The cross-sectional shape of the filament of the present invention may be circular, but may be other shapes such as elliptical, triangular, quadrangular, polygonal and star-shaped. Also, by changing the color of each layer having a multi-layer structure, the color from the root to the tip of the hair can be changed by the number of layers, and the change in color can indicate the degree of wear of the filament.

The stepped portion is attached so that the diameter of the bristle becomes smaller toward the tip of the bristle. This step may be one place,
By applying two or more places, the characteristics of the hair can be changed more finely. The position where the stepped portion is formed is within a range of 1% to 95%, and more preferably within a range of 5% to 70% of the brush length (hair length from the flocking table surface) at a distance from the brush tip. This is because in the case of a general toothbrush, the step portion is in the range of about 0.5 mm to 7.0 mm from the bristle tip, and even if the step portion is extremely on the bristle tip side, the difference in usability is unlikely to appear. ,
In addition, even if a stepped portion is added to the brush root portion, the feeling of use does not change from that of a taper hair having a thin base fiber diameter, which is meaningless.

The filament of the present invention preferably has a multi-core structure composed of a plurality of co-extruded products, but may be formed of a single material as well as the multi-core structure. In the case of the multi-core structure, the step position and the taper shape of each step can be freely changed by arbitrarily setting the thickness of each layer. In the case of using a single material, the process of processing the hair tips having the step portion becomes slightly more complicated than that of the multi-core structure.

The following method can be used as a method of processing the filament with a step portion made of a single material. Method by melting processing The filament is processed into a predetermined shape by controlling the melting site and the melting time stepwise. Method by machining The filament is processed into a predetermined shape by a polishing device. Method by Melt Processing + Mechanical Processing A filament is previously taper-processed by melt processing and then machine-polished into a predetermined shape. Method by melting processing + tip cutting + mechanical polishing processing The filament is previously processed by taper processing by melting processing, then the hair tips are cut, and the filament is processed into a predetermined shape by mechanical polishing.

In the case of a filament having a multi-core structure, each layer of the multi-core structure is made of a co-extruded material having different chemical dissolution efficiency, and this is dipped in a hydrolyzing solution such as sodium hydroxide or acid, and the tip of the hair tip is It is preferably produced by dissolving. At this time, a part of this coextruded product,
In particular, it is preferable that the outer layer portion is made of a polyester resin having a high dissolution rate. Depending on the shape of the tapered portion, a part of the resin having high chemical resistance such as nylon may be used. Further, basically, the outer layer portion is made of a material having higher chemical solubility than the inner layer portion, the outer layer portion having a faster dissolution rate forms a taper shape faster than the inner layer portion, and the inner layer portion lags to form a taper shape. Therefore, it is preferable to form a tapered shape having a step portion.

In the case of taper hair in which the tip end surface of the taper portion is recessed in a cup shape, the inner layer portion forming the cup-shaped recess portion is made of polyester resin having high chemical solubility, and the outer layer portion is nylon. Resins with low chemical solubility such as
Alternatively, it may be made of a polyester resin or the like which has a lower chemical solubility than the inner layer.

To produce the filament of the present invention, different resins are coextruded to form a raw yarn having a multi-core structure, which is cut to a predetermined size. The tip of this cut piece is immersed in a hydrolyzing solution such as sodium hydroxide or acid for dissolution treatment to form a taper with a step due to the difference in solubility, then neutralized, washed and dried. The toothbrush of the present invention can be obtained by implanting the thus obtained filament of the present invention on the bristle surface of the toothbrush head.

The tapering may be performed before the flocking, but after the filaments having a multi-core structure are flocked on the flocking surface of the toothbrush head, the tip of the brush of the brush is dipped in the hydrolysis solution. Then, the taper having the step portion may be formed by performing the melting process.

For the flocking of filaments onto the flocked base surface of the toothbrush head, a normal flocking machine can be used as it is. Even after the flocking, trimming of the bristles and rounding of the tips of the bristles are carried out as necessary. Good. When the taper with the step portion is formed after the flocking, the brush after the flocking may be arbitrarily trimmed or subjected to polishing processing, and then the dissolution treatment with the above-mentioned hydrolysis solution may be performed.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the filament according to the present invention. 1 (a) is an enlarged schematic view of the tip of the filament, and FIG. 1 (b) is shown in FIG.
FIG. 1C is a schematic cross-sectional view taken along line BB in FIG.
FIG. 2 is a schematic cross-sectional view taken along the line CC in FIG.

The first embodiment is a filament 1
Is a double core structure composed of a first resin layer 2a and a second resin layer 2b, and a taper is formed at the tip portion of the filament 1 having the double core structure.
The step portion 3 is formed at the boundary between the second resin layer 2b and the second resin layer 2b. In the case of this example, PBT is used as the first resin layer 2a.
(Polybutylene terephthalate) to the second resin layer 2b
Was used as PTT (polytrimethylene terephthalate).

FIG. 2 shows a second filament of the present invention.
An embodiment of is shown. 2 (a) is an enlarged schematic view of the tip of the filament, FIG. 2 (b) is a schematic cross-sectional view taken along line BB in FIG. 2 (a), and FIG. 2 (c) is in FIG. 2 (a). C
It is a schematic sectional drawing in the -C position.

Like the first embodiment, this second embodiment has a double core structure composed of a first resin layer 2a and a second resin layer 2b. The difference from the embodiment is that the tip side is made thinner and sharper.

FIG. 3 shows a third filament of the present invention.
An embodiment of is shown. 3 (a) is a schematic enlarged view of the tip of the filament, FIG. 3 (b) is a schematic cross-sectional view taken along line BB in FIG. 3 (a), and FIG. 3 (c) is in FIG. 3 (a). C
It is a schematic sectional drawing in the -C position.

The third embodiment is a filament 1
Is a triple core structure composed of a first resin layer 2a, a second resin layer 2b, and a third resin layer 2c, and a taper is formed at the tip of the filament 1 having the triple core structure. A boundary portion between the first resin layer 2a and the second resin layer 2b,
Stepped portions 3a and 3b are formed at the boundary between the second resin layer 2b and the third resin layer 2c. In the case of this example, polybutylene terephthalate is used as the first resin layer 2a.
Polytrimethylene terephthalate was used as the resin layer 2b and polyethylene terephthalate was used as the third resin layer 2c.

FIG. 4 shows a fourth filament of the present invention.
An embodiment of is shown. 4 (a) is a schematic enlarged view of the tip of the filament, FIG. 4 (b) is a schematic sectional view taken along the line BB in FIG. 4 (a), and FIG. 4 (c) is in FIG. 4 (a). C
It is a schematic sectional drawing in the -C position.

The fourth embodiment is a filament 1
This is an example of a case where there is a cylindrical portion without a taper shape in a part of
And a second resin layer 2b have a double core structure, and of these two resin layers 2a and 2b, a resin that is difficult to dissolve in a hydrolysis solution is used for the first resin layer 2a that forms the inner core. However, the first resin layer 2a is not melted and remains in the original cylindrical shape. The step portion 3 is formed at the boundary between the first resin layer 2a and the second resin layer 2b. In the case of this example, nylon was used as the first resin layer 2a and polybutylene terephthalate was used as the second resin layer 2b.

FIG. 5 shows a fifth filament of the present invention.
An embodiment of is shown. 5 (a) is an enlarged schematic view of the tip of the filament, FIG. 5 (b) is a schematic sectional view taken along the line BB in FIG. 5 (a), and FIG. 5 (c) is in FIG. 5 (a). C
It is a schematic sectional drawing in the -C position.

The fifth embodiment is an example in which the tip of the tip of the bristle is recessed in a cup shape, and the filament 1 is made into the first resin layer 2a, the second resin layer 2b, and the first resin layer 2b. A triple core structure composed of three resin layers 2c is adopted, and of these three resin layers 2a, 2b, 2c, the first resin layer 2a constituting the inner core is made of a resin which is easily dissolved in a hydrolysis solution. By doing so, a concave cup is formed at the tip portion of the first resin layer 2a. Steps 3a and 3b
Are formed at the boundary between the first resin layer 2a and the second resin layer 2b and at the boundary between the second resin layer 2b and the third resin layer 2c, respectively. In this example, polyethylene terephthalate was used as the first resin layer 2a, nylon was used as the second resin layer 2b, and polybutylene terephthalate was used as the third resin layer 2c.

FIG. 6 shows a sixth filament of the present invention.
An embodiment of is shown. FIG. 6A is a schematic enlarged view of the tip portion of the filament, FIG. 6B is a schematic sectional view taken along the line BB in FIG. 6A, and FIG. C
It is a schematic sectional drawing in the -C position.

The sixth embodiment has a triple core structure similar to that of the third embodiment (see FIG. 3), and is similar to the first embodiment.
Of the resin layer 2a, the second resin layer 2b, and the third resin layer 2c. In the case of this example, polybutylene terephthalate is used as the first resin layer 2a,
Polytrimethylene terephthalate was used as the second resin layer 2b, and polyethylene terephthalate was used as the third resin layer 2c.

When the colors of the layers of the filament having the multi-core structure are made different as described above, for example, as shown in FIG. 7, when the filament 1 is planted on the planting surface 7 of the head portion 6 of the toothbrush 5, the tip of the brush is brushed. Layer 2 with different colors in parts
a appears, and the degree of wear of the brush can be known from the degree of change in the color of this layer, and can be used as a guide (indicator) of the toothbrush replacement time.

Although each of the above embodiments has shown an example in which a multi-core structure is used, the present invention is not limited to the multi-core structure, and a single material is used to form the above-mentioned shape. Of filaments may be formed.

[0035]

As is apparent from the above description, according to the present invention, the following excellent effects can be obtained. (1) The cleaning efficiency of a portion where the conventional hair for taper is not sufficiently provided with a gap, for example, an extremely narrow gap such as a pit fissure is improved. Further, since the variation of the taper bristle shape can be easily widened, it is possible to design the brush according to the target portion for cleaning. (2) Since a complicated taper shape can be formed, it is possible to make the hair from the root to the middle abdomen thick and have a small taper angle, and make only the tip of the hair a taper shape necessary for entering a gap. As a whole, it is possible to improve the fluffiness of the brush, and to improve the actual feeling of cleaning and the cleaning effect, which is slightly lacking in the conventional taper hair. (3) By making the bristle tip softer, it is possible to eliminate the tingling sensation of the conventional taper bristles, and it is possible to provide a brush that does not feel harmful. (4) By coloring each layer of the multi-core structure, it is possible to create a brush in which the color of the hair from the tip of the hair to the root is sequentially changed. With such a brush, it is possible to provide a brush having a high appearance discrimination. (5) The initial investment can be reduced because a filament having a multi-core structure made of different resins can be manufactured by dissolution treatment and no special equipment is required. (6) If the material of each layer and the thickness of each layer of the multi-core structure are determined, it is possible to form a taper with a step portion by performing chemical treatment in the same process as the conventional chemical-processing taper hair, which is extremely stable. Filaments of the desired quality can be easily manufactured. (7) By adopting the filament of the present invention in which the tapered shape is finely set, it is possible to provide a toothbrush which is excellent in the clearance penetration property and the contact feeling and at the same time has a high feeling of cleaning.

[Brief description of drawings]

FIG. 1 shows a first embodiment of a filament according to the present invention, (a) is a schematic enlarged view of a filament tip portion,
(B) is a schematic cross-sectional view taken along line BB in (a),
(C) is a schematic sectional view taken along the line CC in (a).

FIG. 2 shows a second embodiment of the filament according to the present invention, in which (a) is a schematic enlarged view of a filament tip portion,
(B) is a schematic cross-sectional view taken along line BB in (a),
(C) is a schematic sectional view taken along the line CC in (a).

FIG. 3 shows a third embodiment of a filament according to the present invention, (a) is a schematic enlarged view of a filament tip portion,
(B) is a schematic cross-sectional view taken along line BB in (a),
(C) is a schematic sectional view taken along the line CC in (a).

FIG. 4 shows a fourth embodiment of the filament according to the present invention, in which (a) is a schematic enlarged view of a filament tip portion,
(B) is a schematic cross-sectional view taken along line BB in (a),
(C) is a schematic sectional view taken along the line CC in (a).

FIG. 5 shows a fifth embodiment of the filament according to the present invention, (a) is a schematic enlarged view of a filament tip portion,
(B) is a schematic cross-sectional view taken along line BB in (a),
(C) is a schematic sectional view taken along the line CC in (a).

FIG. 6 shows a sixth embodiment of a filament according to the present invention, (a) is a schematic enlarged view of a filament tip portion,
(B) is a schematic cross-sectional view taken along line BB in (a),
(C) is a schematic sectional view taken along the line CC in (a).

FIG. 7 is a schematic side view of a toothbrush made using the filament according to the sixth embodiment.

[Explanation of symbols]

1 filament 2a First resin layer 2b Second resin layer 2c Third resin layer 3,3a, 3b Stepped portion 5 toothbrush 6 head 7 Flocking surface

Claims (3)

[Claims] 1. A filament, wherein the bristle portion is tapered, and the tapered portion has at least one step portion. 2. The filament according to claim 1, wherein the filament has a multi-core structure of two or more layers made of different resins. 3. A toothbrush having the filament according to claim 1 or 2 implanted therein.