JP2002051838A - Toothbrush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothbrush which has a movable head, is improved in cleaning performance and fitness as the important performance of the toothbrush and is improved in moldability as well. SOLUTION: The toothbrush consisting of a head, neck and handle is formed with at least >=1 connecting parts 12 which are partly or wholly formed of soft resins and have flexibility in the suitable intermediate positions of the head 11 consisting of a rigid resin so that the front end side 11a of the head may be elastically bent and moved to the front and rear surface direction of the head 11 with the connecting parts 12 as borders.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothbrush in which a part of a head portion can be elastically moved according to a brushing force.

[0002]

2. Description of the Related Art In a general toothbrush, the entire toothbrush head portion is made of a hard resin, and a brush is usually planted in the hard resin portion. For this reason, the brush bends during brushing, but the head itself does not substantially bend, and the brush tip should fit the unevenness in the oral cavity, such as the back teeth to the front teeth, and the curved part along the buccolingual dentition. Was difficult.

In order to eliminate such a problem, a toothbrush having a movable head has been proposed. For example, a toothbrush having a movable head has a hinge. The one with the effect (Table 5-
No. 501221), two or more segments connected flexibly and resiliently (Japanese Patent Laid-Open No. 6-50779).
No. 2), one in which the relative position fluctuates due to elastic deformation of the elastic material (Japanese Patent Application Laid-Open No. 9-19323), one in which the brush bundle base end is held by an elastic body (Japanese Utility Model Laid-Open No. 1-81924).
No.) are known.

[0004] In addition, a hair implanted on a soft resin elastic material on the implanted surface (Japanese Utility Model Application Laid-Open No. 63-93829), the head portion has an extension portion substantially thinner than the grip portion, and the free end of the hair is substantially concave. (Table 11-502)
No. 846), one in which the tip portion and the base portion are connected with flexibility and elasticity at the connecting portion (Japanese Patent Application Laid-Open No. 11-511343)
No.) have also been proposed.

[0005] With the advent of these conventional toothbrushes having mobility, the fit has been somewhat improved, but there has been no clear definition of the appropriate movable range of the head and the area of the connecting portion. In addition, the brush bundle is fixed only to the hard resin portion, and in each case, the flocked portion is divided by the connecting portion, and there are restrictions on the design of the flocked specification.

[0006] Further, in the conventional toothbrush having movability, in many cases, the hard resin of the movable portion is formed to have a thin structure in order to impart movability to the head portion. Such a thin portion is manufactured by injection molding. In this case, the filling property of the resin in the mold cavity was poor, and the moldability at the time of manufacturing was poor.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in a toothbrush having a movable head, the cleaning performance and the fit, which are important as the performance of the toothbrush, are improved. It is an object of the present invention to provide a toothbrush with improved moldability.

[0008]

According to a first aspect of the present invention, there is provided a toothbrush including a head portion, a neck portion, and a grip portion. At least one flexible connecting part formed entirely or softly of a soft resin;
One or more are formed, and the front end side of the head portion can be elastically bent and movable toward the front and back surfaces of the head portion with the connection portion as a boundary. With such a configuration, the cleaning performance and fit, which are important as the performance of the toothbrush, can be further improved.

According to a second aspect of the present invention, in the first aspect of the present invention, an inclination formed by an axis connecting the central portion of the front end of the head portion and the central portion of the rear end of the head portion with respect to the longitudinal central axis of the head portion. When the angle is θ, the head end side is θ = 1 °
It can be bent and moved within a range of up to 85 °. With such a configuration, the fitting property of the brush bundle to various irregularities in the oral cavity is improved, and the cleaning performance which is important as the performance of the toothbrush can be improved.

According to a third aspect of the present invention, in the first aspect of the present invention, the area of the head portion that bends and moves is set to 10 to 90% of the area of the entire head portion.
With such a configuration, it is possible to improve the cleaning performance which is excellent as the performance of the toothbrush, having excellent fitting properties to various irregularities in the oral cavity.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the area or volume of the connecting portion is set to 1.0% to 40% of the total area or total volume of the head portion. By adopting such a configuration, the head has sufficient strength to withstand repeated use, and is a compact head with excellent usability. Fits well with the dentition by providing excellent flexibility and elasticity,
In addition, a toothbrush that prevents excessive brushing power can be obtained.

According to a fifth aspect of the present invention, in the first aspect of the present invention, when the connecting portion is formed by combining a soft resin and a hard resin, the hard resin has a thickness relative to a thickness of the head portion at the connecting position. The ratio of the minimum thickness is 0.
5% to 50%. With such a configuration, it is possible to obtain a head portion strength enough to withstand repeated use, and also to obtain a moderate elasticity and a real feeling of movement.

According to a sixth aspect of the present invention, in the first aspect of the present invention, a brush or a bundle of brushes is planted also at the connecting portion. With such a configuration, it is possible to obtain a toothbrush that has no restriction on the design of the flocking specification and does not have good adhesion to the dentition at the time of brushing, and is comfortable against teeth and gums.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the MFR of the hard resin constituting the head portion is used.
(Melt flow rate) 5 to 70 g / 10 min
(Test method JIS K7210, test temperature 230 ° C., test load 2.16 kg / cm ² ). With such a configuration, it is possible to obtain a toothbrush that has a high fit to various irregularities in the oral cavity and has excellent moldability.

The hard resin used in the above-described toothbrush of the present invention may be a thermoplastic resin having a resin hardness relatively higher than that of the soft resin forming the connecting portion. Examples of the hard resin include polypropylene, polyethylene, and polyester (polyethylene terephthalate). , Polybutylene terephthalate, etc.), polyamide, polymethyl methacrylate,
Cellulose propionate, polyurethane, ABS, polycarbonate (including blends with polyester),
Polyarylate (including blends with polyester),
Polyoxymethylene, AS resin, ABS resin, PMMA
Resin, cellulose propionate and the like can be used. When viewed comprehensively in terms of physical properties, cost, and the like, polypropylene is most preferable. In addition, the flexural modulus is 500 to 3
000 MPa (JIS K7203) is preferable. Further, a multicolor molded handle in which these resins are combined with each other or a thermoplastic elastomer described later can also be used.

As the soft resin, polyolefin TP is used.
E (TPE; thermoplastic elastomer), polystyrene-based TPE, polyurethane-based TPE, polyester-based TP
E, 1,2-polybutadiene TPE, ethylene-vinyl acetate TPE, polyvinyl chloride TPE, natural rubber TP
E, fluorine-based TPE, trans-polyisoprene-based TP
Various TPEs, such as E, can be used. The flexural modulus is 1 to 500 MPa, more preferably 1 to 500 MPa.
~ 150MPa is good. The hardness (test method JIS
K6253, type A) is preferably from 5 to 100, more preferably from 20 to 60. In addition, tensile strength 10
It is preferable to use one of ~800kg / cm ^2. Further, these resins may be mixed. Further, a two-component mixed type thermosetting silicone resin may be used instead of the thermoplastic elastomer.

An actual handle is used by appropriately combining these hard resin and soft resin. However, in consideration of physical properties, price and mutual compatibility required as a material for a toothbrush,
It is preferable to use a combination of polypropylene and polyolefin-based TPE or a combination of polypropylene and polystyrene-based TPE. For example, polyolefin-based TPE
Is EPDM (ethylene-propylene-
Diene terpolymer), polypropylene is selected as a hard component, and these are blended and partially or entirely crosslinked.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. In general, a toothbrush with a non-movable head portion does not have a very high fit to a tooth surface, but a toothbrush with a movable head portion has a high fit to a tooth surface. However, even in a toothbrush having a movable head portion, if the head portion moves too much, the cleaning force is not easily transmitted to the tooth surface, and the cleaning effect is reduced. Therefore, in the first embodiment, in order to fit the brush to various irregularities of the tooth surface in the oral cavity and to improve the brushing effect, the movable range of the head portion is defined by an optimum angle range. is there.

That is, as shown in FIG.
Is divided into two parts, a front head section 1a made of hard resin, and a rear head section 1b. The front head section 1a made of hard resin and the rear head section 1b are connected by a connecting section 2 made of soft resin 4. At the position of the connecting portion 2, the distal end side head portion 1a is bent and movable.
When the formed bending angle of the axis connecting the head portion distal the central portion P ₁ and the head portion rear central portion P ₂ relative to the longitudinal axis the central axis X-X of the head portion 1 and theta, distal side head portion 1a Are set to be movable at least in the range of θ = 1 ° to 85 ° toward the back side of the head portion. In addition,
Reference numeral 3 denotes a brush bundle implanted on the implanted surface (upper surface) of the head unit 1.

FIG. 2 shows a second embodiment of the present invention. In the second embodiment, the head unit 1 includes a front head unit 1a, a rear head unit 1b, and an intermediate head unit 1c.
And these are connected by two connecting portions 2a and 2b made of a soft resin 4. At the positions of the two connecting portions 2a and 2b, the distal head portion 1a and the intermediate head portion 1 are connected.
c can be bent and moved,
The center part P of the head tip with respect to the major axis XX of the head part 1
₁ and when the formed bending angle of the axis connecting the head portion rear central portion P ₂ and theta, possible movable range of the distal head portion 1a toward at least the head portion back side theta = 1 ° to 85 ° It is set so that

With the configuration as in the first and second embodiments, when a pressing force is applied to the head 1 during brushing, the front end side head 1a (and the intermediate head 1c) has a tooth surface or an intermediate head. It bends and moves as indicated by the solid line from the chain line in the figure according to the unevenness in the oral cavity, and reliably fits the tooth surface and the uneven portion in the oral cavity. Therefore, the cleaning effect can be improved, and the feeling of actual cleaning can be improved.

Generally, the brushing force when a person brushes his teeth is 1 to
It is about 6 [N], and even a strong person is about 15 [N]. The recommended brushing force during brushing for a toothbrush in which the head is continuously or partially movable is 2-3 [N] or 2-4 [N]. By setting the angle to an arbitrary angle of 1 ° to 80 °, the fitting property of the brush bundle 3 to the unevenness of the tooth surface increases,
The brushing effect is improved. When the bending angle θ is 1 ° to 75 °, the brushing force is more reliably transmitted to the tooth surface, which is preferable.

In the above case, the movable range is represented by the bending angle θ, but when the bending angle θ is applied to a toothbrush of a general size and represented by the distance L in the drawing, θ = 1 ° to 8 °
At 0 °, L = 0.1 mm to 20 mm, and at θ = 1 ° to 75 °, L = about 0.1 mm to 15 mm.

The connection between the movable part and the fixed part may be one or more thin hinges, thin rods, linear connections, curved or wavy connections. May be. Further, it may extend over the entire head transverse direction and / or longitudinal direction, may have one or more through-holes partially, and may partially extend in the head part transverse direction and / or longitudinal direction. Or, there may be a plurality in the same connecting portion. Alternatively, the connection may be made with only a soft resin.

When the connecting portion is filled with a soft resin having a lower elastic modulus than the hard resin constituting the head portion, the contact with the teeth and gums in the oral cavity becomes gentler and the elasticity of the head portion is complementarily improved. The effect which makes it do is also obtained. Moreover,
Since there is a buffering effect on the transmission of a direct force to the hard resin portion, the head strength can be improved.

The soft resin portion is not limited to the connecting portion, and may have an area spread on a flocked surface, a back surface, or the like. In this case, the contact area between the soft resin portion and the hard resin portion is increased, and the method of applying the force by brushing is dispersed, so that the peel strength is improved. Further, the setting is such that the soft resin contracts to about 50% of the state without stress or stretches to about 250%, but the peel strength can be further improved. It is more preferable that the soft resin has a shrinkage ratio of up to 80% and an elongation of up to 240%, since the brushing force is more reliably transmitted to the tooth surface. In addition, it is preferable to cover the periphery of the head portion with a soft resin, because the feeling of contact with the oral cavity becomes softer.

The soft resin portion may be formed separately and independently at each portion, and may be formed by providing a plurality of injection gates. However, a flow path connecting these portions may be formed with a flocking surface or a back surface of the head. When the injection gate is set to
It can be coated in a single injection molding operation and is efficient. Furthermore, you may make it connect with the soft resin of a handle neck part and a grip part.

The planar shape of the movable portion and the soft resin portion filled therein is preferably formed so as to cross and / or longitudinally cross the head, but the shape is not limited. The boundary with the fixed portion does not necessarily have to be a straight line substantially perpendicular to the long axis or horizontal axis of the head portion, and the shape of the connecting portion may be, for example, polygonal, circular, convex lens shape, concave lens shape, curved band shape (U (Shape, C-shape, wavy).

The material of the brushes constituting the brush bundle 3 is as follows.
A commonly used polyamide (eg, nylon 6-1)
2, nylon 6-10, 12 nylon, etc.), polyester (for example, polybutylene terephthalate, polyethylene terephthalate, etc.), polypropylene and the like can be used. Of course, a composite material combining these may be used. Moreover, you may combine with natural hair as needed. The cross-sectional shape of the brush is mainly circular, but is not particularly limited. For example, a brush having a polygonal cross section such as a triangle, a quadrangle, and a hexagon can be used.

The brush thickness is 3 to 12 mils (0.076 to
0.305 mm), preferably 5-11 mils (0.12 mm
7 to 0.279 mm) is good for general toothbrushes. Further, tapered bristles, bristles having a spatula shape, a thin and wide shape, a spherical shape, a cracked shape, and the like may be used in combination as necessary.

Regarding the shape of the cleaning surface formed by the bristle tips of the brush bundle 3, as in the case of a normal toothbrush, by setting the bristle shape and the brush length (for example, 7 mm to 13 mm) arbitrarily, A mountain-cut shape, a round shape, a convex shape at the tip, or the like can be provided. Those having different brush thicknesses may be mixed in the flocked portion. Also, different configurations may be used for the outside and inside, the front end and the rear end, and the like.

The number of brushes in one brush bundle is appropriately determined in a filling ratio of 50 to 80% according to the brush diameter and the cross-sectional area of the brush bundle. One may be independent, or a form in which a small number of about 2 to 10, for example, may be integrated. The cross-sectional shape of the bristle bundle is usually circular (1 mm to 5 mm in diameter), but is not limited to this, and various shapes such as an ellipse, polygon, quadrangle, and triangle can be used. Also, a combination of these shapes may be used. Further, the directions may be aligned substantially in the brush long axis direction, substantially in the horizontal axis direction, or these directions may be combined.

As the overall shape of the toothbrush handle, for example, the grip portion, neck portion and head portion may be arranged in a straight line to form a straight-type handle as a whole, or a handle having a gentle S-shape as a whole. Then, the neck portion may be inclined or curved toward the flocking surface side or the back surface side, or may have a positional relationship such that the head portion is offset with respect to the grip portion.

The shape of the flocking surface of the head portion 11 may be straight (flat) or from the neck to the tip.
A substantially concave shape having a radius of curvature of 300 mm or less, preferably 200 mm or less, or 45 ° or less, preferably 30 ° or less.
It may be formed to have one or more bending angles. In the case of such a shape, it is possible to improve the plaque scraping effect of the brush at the tip part in a part where the bristle tip is difficult to reach, such as the back of the tooth and the back of the back tooth, and it is possible to improve the fit property. it can.

The method of fixing the brush bundle 3 to the flocking surface of the head portion 1 is a flat wire type flocking method in which the brush bundle 3 is fixed using a metal piece (flat wire).
Japanese Patent Application Laid-Open No. Sho 60-241404 discloses a heat fusion method in which the end portion of a brush bundle is melted and press-fitted into a toothbrush head portion to be fixed.
A known method such as an in-mold method of manufacturing a toothbrush by heating a lower end of a brush or a bundle of brushes to form a molten mass as in No. 512724 and then injecting a molten resin into a mold may be used. it can.

The structure of the connecting portion, the arrangement of the soft resin portion, the material and thickness and shape of the brush, the overall shape of the toothbrush handle, and the method of fixing the brush bundle to the head planting surface are described below. The same applies to other embodiments, and a description thereof will be omitted in the following embodiments.

FIG. 3 shows a third embodiment of the present invention. In the third embodiment, in order to fit a brush to various irregularities of the tooth surface in the oral cavity and to improve a brushing effect, an area ratio of a bending movable head portion to an entire head portion is optimally defined. It was done.

That is, as shown in FIG.
Is divided into two parts, a front head section 1a and a rear head section 1b, and the front head section 1a and the rear head section 1b are connected by a connecting section 2 made of a soft resin 4. The tip side head portion 1a is bent and movable at the position, and the area (hatched portion in the figure) of the tip side head portion 1a is 10% of the entire head portion 1.
% To 90%.

With such an area ratio,
A good fit of the bristle tip of the brush 3 at the front end head portion 1a with respect to the unevenness of the tooth surface is obtained, while a high plaque removing power is obtained by the fixed brush bundle 3 at the rear end head portion 1b. The cleaning effect is improved by these balances. It is more preferable that the area ratio be 15% to 80%. Further, the content is more preferably set to 20% to 70%.

FIG. 4 shows a fourth embodiment of the present invention. In the fourth embodiment, the head unit 1 includes a front head unit 1a, a rear head unit 1b, and an intermediate head unit 1c.
And these are connected by two connecting portions 2a and 2b made of a soft resin 4. At the positions of the two connecting portions 2a and 2b, the distal head portion 1a and the intermediate head portion 1 are connected.
c can be bent and moved,
The area of the tip side head portion 1a and the intermediate head portion 1c (hatched portion in the figure) is 10
% To 90%. It is more preferable that the area ratio be 15% to 80%. Further, the content is more preferably set to 20% to 70%.

With the configuration as in the third and fourth embodiments, when a pressing force acts on the head 1 during brushing, the front end side head 1a (and the intermediate head 1c) may have a tooth surface or the like. It bends and moves as indicated by the solid line from the dashed line in the figure according to the unevenness in the oral cavity, and reliably fits the tooth surface and the uneven portion in the oral cavity. Therefore, the cleaning effect can be improved, and the feeling of actual cleaning can be improved.

FIG. 5A shows a fifth embodiment of the present invention. In the fifth embodiment, in a toothbrush including a grip portion, a neck portion, and a head portion, a concave portion is formed near the center of a flocking surface of a head portion 11 made of a hard resin, and a soft resin 14 is filled in the concave portion. The head 11 is divided into two parts, a front head 11a and a rear head 11b.
1a is capable of elastically bending and moving in the vertical direction, and the ratio of the area of the connecting portion 12 to the area of the head portion 11 is 1.0% to 40%, preferably 1.0% to 30%.
%.

In an actual toothbrush, the length of the head portion in the long axis direction of the toothbrush is 10 mm to 30 mm, preferably 15 mm to 28 mm. Further, the width of the head portion is preferably 5 mm to 20 mm, and more preferably 7 mm to 15 mm.

Similarly, the ratio of the volume of the connecting portion 12 to the volume of the head portion is 1.0% to 40%, preferably 1.%.
When it is 0% to 30%, as in the case described above, the utilization efficiency of the head part flocked surface is improved, and the connection part is concentrated, so that a higher elasticity and movable feeling can be obtained at the time of brushing. , A pleasant feel.

By setting the area ratio or the volume ratio of the connecting portion 12 to the above value, the blanking portion of the bridging by the connecting portion 12 is reduced, and the area of the head portion flocked surface which is not directly involved in the brushing is minimized. be able to. For this reason, the utilization efficiency of the head part flocked surface is enhanced, and the same degree of freedom of the hair bundle arrangement as that of a normal toothbrush can be provided.

Further, since the connecting portion 12 is filled with the soft resin 14, the contact between the teeth and the gums in the oral cavity becomes gentler, and the effect of supplementing and improving the elasticity of the head portion can be obtained. Further, the head has an effect of buffering the transmission of direct force to the hard resin portion, so that the head strength can be improved.

When the thickness of the hard resin of the head portion at the position of the connecting portion 12 is reduced, the flexibility of the connecting portion 12 is increased, but the brushing force is not transmitted well and the usability is extremely deteriorated. If it is too thick, on the other hand, it loses flexibility and becomes no different from existing toothbrushes. The minimum thickness of the hard resin in the connecting portion 12 is 0.05 mm
It is good to be -3.0 mm, preferably 0.05 mm -2.5 mm. That is, the ratio of the minimum thickness of the hard resin to the thickness of the head portion at the connection position is 0.5% to 50%.
%, Preferably 0.5% to 40%, the head has sufficient strength to withstand repeated use, and a moderate elasticity and movable feeling can be provided.

The head portion hard resin at the position of the connecting portion 12 may be in the form of a thin hinge or a thin rod.
It may be connected in a straight line or may be connected in a curved or wavy shape, may be formed with concave portions facing from both the flocking surface side and the back surface side, and the formation position on the front and back surfaces of the head part They may be shifted and provided at different positions.

The connecting portion 12 is preferably formed so as to cross at right angles to the width direction of the head portion 1, but the planar shape is not limited. For example, any shape such as a polygon, a circle, a convex lens shape, a concave lens shape, and a curved band shape can be adopted.

FIGS. 5B to 5J show modified examples of the fifth embodiment. In the drawing, FIG.
Is provided on the back side of the head portion 11, and FIG.
2 is an example in which the connecting portion 12 is embedded on the front and back surfaces of the head portion 11;
(F) shows an example in which the connecting portion 12 is formed only of a soft resin or is formed by penetrating the front and back sides of the head, and (g) shows the brush bundle 13 standing upright on the flocking surface of the curved head portion 11. (H) is an example in which the brush bundle 13 implanted forward from the connecting portion 12 is inclined rearward with respect to the head implanted surface, and (i) is a tip with the connecting portion 12 as a boundary. An example in which the brush bundles 13 on the side and the rear end are arranged so as to be inclined in the direction of each other, (j) shows two connecting portions 1 on the head portion 11.
2a and 12b are formed, and the head 11 is divided into three parts, a front head 11a, a rear head 11b, and an intermediate head 11c.

FIG. 6 shows an example of the planar shape of the toothbrush according to the fifth embodiment. In the drawings, (a) shows an example in which the connecting portion 12 is formed in a concave shape toward the front, (b) shows an example in which the connecting portion 12 is formed in a concave shape toward the rear, and (c) shows the connecting portion 12 in a forward direction. To form a concave shape,
An example in which the outer periphery of the head portion 11 is surrounded by a soft resin 14, (d)
(E) is an example in which the connecting portion 12 has a concave band shape having the same width.
Is an example in which the soft resin portion 15 is also formed in the longitudinal direction of the head portion in addition to the connecting portion 12, (f) is an example in which the connecting portion 12 is formed in a linear band having a constant width, and (g) is a linear band having a constant width. This is an example in which the connecting portions 12a and 12b are formed at two locations before and after the head portion 11.

FIG. 7 shows a sixth embodiment of the present invention. In the sixth embodiment, a brush or a bundle of brushes is planted at a bent connecting portion in order to increase the efficiency of planting a brush or a bundle of brushes and further improve the cleaning performance and fit of the toothbrush. is there.

That is, as shown in FIG.
Three large and small concave portions are formed on the back side of the
By filling the concave portions with the soft resin 24, the connecting portions 2
2, and the hair bundle 23 is implanted without gaps at the head implanted surface position opposite to the connecting portion 22.

In this example, as the brush bundle 23, 36 brushes having a diameter of about 0.203 mm are bundled to form a bundle of about 1.44 m in diameter.
m, and the soft resin 24 forming the connecting portion 22 has a hardness (test method JIS K
An olefin-based thermoplastic elastomer consisting of 6253, type A) 35 was used.

The head portion 21 made of hard resin and the neck portion and grip portion connected to the head portion 21 have a flexural modulus of 1900.
MPa (JIS K7203), Rockwell hardness 11
2 (JIS K7202).

With such a configuration, the brush bundle 23 is also implanted at the bent connecting portion 22, so that a gap without the brush bundle is not formed on the head section implantation surface. For this reason, the close contact with the dentition at the time of brushing is improved, and a toothbrush that is comfortable against teeth and gums can be obtained. In addition, since the brush or the brush bundle can be implanted on the entire surface of the implanted surface, the design of the implanting specification is restricted, and the degree of design freedom is improved.

FIG. 8 shows a seventh embodiment of the present invention. In the seventh embodiment, in a head portion structure similar to that of FIG. 7, the tip side of the head portion 21 is inclined at a predetermined angle toward the head portion flocking surface at the position of the connecting portion 22. . That is, the tip side of the head portion 21 is approximately 2
The brush bundle 23a having a hair bundle diameter of 4 mm is inclined by 0 ° to the head part flocking surface side.
At the same time, a brush bundle 23b having a hair bundle diameter of 1.5 mm was planted on the other horizontal flocking surface portion, and the brush bundle 23a having a large diameter at the inclined surface portion further improved the cleaning function of the back teeth. . The connecting portion 22 is set so as to be located at approximately ほ ぼ of the entire length of the head portion from the base of the head portion 21 on the neck side toward the head end portion.

FIG. 9 shows an eighth embodiment of the present invention. In the eighth embodiment, an arc-shaped concave portion is formed on the back surface side of a head portion 21 curved at a predetermined curvature toward the flocking surface side, and the concave portion is filled with a soft resin 24 to form a connecting portion 22.
The hair bundle 23 is also implanted at the head implanted surface position opposite to the connecting portion 22.

FIG. 10 shows a ninth embodiment of the present invention. In the ninth embodiment, the connecting portion 22 is formed by forming three large and small concave portions having a mountain shape on the flocking surface side of the head portion 21 having a straight shape, and filling the three concave portions with the soft resin 24. Are formed, and the hair bundles 23 are planted on the connecting portions 22 as well.

FIG. 11 shows a tenth embodiment of the present invention. In the eleventh embodiment, an arc-shaped concave portion is formed on the flocking surface side of the head portion 21, and a soft resin 24 is formed in the concave portion.
And forming the connecting portion 22 by filling
At the position of the connecting portion 22, the tip of the head portion is inclined toward the head portion flocked surface side, and the bristle bundle 23b is also planted at the portion of the connecting portion 22 made of the soft resin 24.

FIG. 12 shows an eleventh embodiment of the present invention. In the eleventh embodiment, an arc-shaped concave portion having a large curvature is formed on the flocking surface side of the head portion 21 curved at a predetermined curvature toward the head portion flocking surface side, and a soft resin 24 is formed in the concave portion. The connection portion 22 is formed by filling, and the bristle bundle 23 is planted at the portion of the connection portion 22 made of the soft resin 24.

FIG. 13 shows a twelfth embodiment of the present invention. In the twelfth embodiment, the tip of the head portion is inclined toward the flocked surface side, and the connecting portion 22 is made of only the soft resin 24, and the bristle 23b is also planted on the connecting portion 22. It is.

FIG. 14 shows a thirteenth embodiment of the present invention. In the thirteenth embodiment, the front end side of the head portion is inclined toward the flocked surface side, arc-shaped concave portions are formed on both the front and back surfaces of the head portion 21, and the soft resin 24 is filled in the concave portions on the front and back surfaces. In this way, the connecting portion 22 is formed, and the brush 23b is also implanted in the portion of the connecting portion 22 on the flocked surface side.

When a thermoplastic elastomer is used as the soft resin 24 in the above-described sixth to thirteenth embodiments, an olefin or styrene-based resin that can have a soft resin hardness is preferable.

The softness of the soft resin 24 is not particularly limited and is appropriately selected according to the required elasticity of the head portion. The hardness is 5 to 60 (test method JIS K6).
253, type A), preferably from 20 to 50.

The cross-sectional shape of the soft resin 24 is preferably substantially triangular or substantially semicircular, but is not particularly limited, and may be appropriately selected in consideration of the degree of elasticity of the head portion and the usability in the oral cavity. Is done.

The connecting portion 22 is formed of one or a plurality of soft resins 24 as shown in the figure. When there are a plurality of soft resins 24, their sizes may be the same or different.

The connecting portion 22 may extend over the entire head portion or may be unevenly distributed. In the case of eccentric distribution, in the case of one, the position between the center of the head part and the head part front direction, and further, about 2 /
3 is more preferable (FIGS. 9, 11, 12, and 1).
3, see FIG. 14).

In the case of uneven distribution, if the plurality of soft resins 24 have the same size, the soft resin at the center of the plurality of soft resins 24 is located at a position between the center of the head and the tip of the head. More preferably, the position is about 2/3 from the base of the neck toward the distal end.

In the case of uneven distribution, the soft resin 2
In the case where 4 is composed of a plurality of irregular sizes, the largest soft resin among the plurality is located at a position between the center of the head portion toward the head end and further from the base of the neck toward the end. A 2/3 position is more preferable (see FIGS. 7, 8, and 10).

FIG. 15 shows an example of the back surface and plan shape of the toothbrush according to the sixth to thirteenth embodiments.
(A) shows an example in which three connecting portions 22 are formed on the back side of the head portion, and (b) shows one connecting portion 22 on the back side of the head portion.
(C) shows an example in which a connecting portion 22 is formed on the head portion flocked surface side, and a brush bundle 23 is also implanted on the connecting portion 22.

FIGS. 16 to 18 show the fourteenth to first aspects of the present invention.
A sixth embodiment will be described. According to the fourteenth to sixteenth embodiments, the MFR (melt flow rate) of the hard resin used for the head portion and the ideal MFR of the soft resin used for the connecting portion are defined. The brush fits the unevenness of various tooth surfaces in the brush, improves the brushing effect, and improves the moldability as a toothbrush.

That is, in manufacturing the toothbrush of the present invention, as shown in FIGS. 16 to 18, a concave portion 35 is formed at a predetermined position of a head portion 31 made of a hard resin, and a soft resin 34 is formed in the concave portion 35. When the connecting portion 32 is formed by filling the thin portion, a thin portion 36 of the hard resin is generated at the portion of the connecting portion 32. When a toothbrush having such a thin portion 36 is manufactured by injection molding, if the MFR or injection pressure of the hard resin is small, the filling rate of the hard resin in the mold cavity becomes poor, while the MFR or injection pressure is reduced. Is too large,
Burrs are likely to appear at the molding stage.

Therefore, in the toothbrushes according to the fourteenth to sixteenth embodiments, at least the hard resin constituting the head portion 31 has an MFR of 5 to 70 g / 10 min (test method J
ISK7210, test temperature 230 ° C, test load 2.16
By setting it in the range of Kg / cm ² ), the moldability is improved, and at the same time, the occurrence of burrs is suppressed. The MFR is more preferably from 7 to 65 g / 10 min, and even more preferably from 9 to 60 g / 10 min. The effect of the MFR is more remarkable in a toothbrush in which the thickness of the thin portion 36 is 1 mm or less.

Further, the MFR of the hard resin is set in the above range, and at the same time, the MFR of the soft resin 34 is set to 0.01 to 70 g / 10 min (test method JIS K7210, test temperature 230 ° C., Test load 2.
When it is set in the range of 16 kg / cm ² ), the moldability of the soft resin and the adhesion (bonding) to the hard resin are improved, and the generation of burrs of the soft resin can be suppressed.

The use of such an MFR soft resin makes it easier to contact the teeth and gums in the oral cavity and also has the effect of complementarily improving the elasticity of the head.
Further, since there is a buffering effect on the transmission of direct force to the hard resin portion, the strength of the head portion can be improved. The MFR of the soft resin 34 is 0.05 to 65.
g / 10 min, more preferably 0.08 to 60 g.
/ 10 min is more preferable.

As described above, the shape of the thin portion 36 may be a hinge shape, a thin rod shape, may be linearly connected, or may be a curved or wavy shape. In addition, the size may be the entire width of the head portion 31 in the width direction or may be partial.

[0079]

As described above, in the case of the toothbrush of the present invention, a flexible connecting portion, a part or whole of which is formed of a soft resin, is provided at an appropriate position in the middle of a head portion made of a hard resin. Since at least one or more are formed, and the front end side of the head portion can be elastically bent and movable in the front and back direction of the head portion with the connection portion as a boundary,
The cleaning performance and the fit, which are important as the performance of the toothbrush, can be further improved. Further, by setting the MFR of the resin to be used to an optimum value, the moldability as a toothbrush can be further improved.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention;
(A) is a schematic plan view of a head part, and (b) is a schematic side view of a head part.

FIG. 2 shows a second embodiment of the present invention.
(A) is a schematic plan view of a head part, and (b) is a schematic side view of a head part.

FIG. 3 shows a third embodiment of the present invention;
(A) is a schematic plan view of a head part, and (b) is a schematic side view of a head part.

FIG. 4 shows a fourth embodiment of the present invention.
(A) is a schematic plan view of a head part, and (b) is a schematic side view of a head part.

FIG. 5 shows a fifth embodiment of the present invention,
(A)-(j) is a figure which shows the various examples of the head part side surface shape of the toothbrush which concerns on 5th Embodiment.

FIGS. 6 (a) to 6 (g) are views showing examples of the planar shape of the head portion of the toothbrush according to the fifth embodiment.

FIG. 7 is a schematic side view of a head portion of a toothbrush according to a sixth embodiment of the present invention.

FIG. 8 is a schematic side view of a head portion of a toothbrush according to a seventh embodiment of the present invention.

FIG. 9 is a schematic side view of a head portion of a toothbrush according to an eighth embodiment of the present invention.

FIG. 10 is a schematic side view of a head portion of a toothbrush according to a ninth embodiment of the present invention.

FIG. 11 is a schematic side view of a head portion of a toothbrush according to a tenth embodiment of the present invention.

FIG. 12 is a schematic side view of a head portion of a toothbrush according to an eleventh embodiment of the present invention.

FIG. 13 is a schematic side view of a head part of a toothbrush according to a twelfth embodiment of the present invention.

FIG. 14 is a schematic side view of a head portion of a toothbrush according to a thirteenth embodiment of the present invention.

15A and 15B show examples of the back surface and the planar shape of the toothbrush according to the sixth to thirteenth embodiments, and FIG. 15A shows an example in which three connecting portions are formed on the back side of the head portion. FIG. 1B shows an example in which one connecting portion is formed on the back side of the head portion, and FIG. 1C shows a case where a connecting portion is formed on the head planting surface side and a brush is also provided on this connecting portion. It is a figure which shows the example at the time of flocking a bundle.

FIG. 16 shows a fourteenth embodiment of the present invention.
(A) is a schematic side view of a head part, (b) is a schematic plan view of a head part.

FIG. 17 shows a fifteenth embodiment of the present invention.
(A) is a schematic side view of a head part, (b) is a schematic plan view of a head part.

FIG. 18 shows a sixteenth embodiment of the present invention.
(A) is a schematic side view of a head part, (b) is a schematic plan view of a head part.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 head portion 1a front end side head portion 1b rear end side head portion 1c intermediate head portion 2 connecting portion 2a, 2b connecting portion 3 brush bundle 4 soft resin 11 head portion 11a front end side head portion 11b rear end side head portion 12 connecting portion 12a , 12a Connecting part 13 Brush bundle 14 Soft resin 21 Head part 22 Connecting part 23 Brush bundle 23a, 23b Brush bundle 24 Soft resin 31 Head part 32 Connecting part 34 Soft resin 35 Depressed part 36 Thin part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takao Kato 1-3-7 Honjo, Sumida-ku, Tokyo Inside Lion Corporation (72) Inventor Shingo Suzuki 1-3-7 Honjo, Sumida-ku, Tokyo F term in Lion Corporation (reference) 3B202 AA06 BA02 BB03 BB04 CB08 DA10 DB01

Claims (7)

[Claims] 1. A toothbrush comprising a head portion, a neck portion and a grip portion, wherein at least a flexible connecting portion, part or all of which is formed of a soft resin, is provided at an appropriate position in the middle of a head portion made of a hard resin. A toothbrush, wherein at least one is formed, and a tip end side of the head portion can be elastically bent and movable in a direction of the front and back surfaces of the head portion with the connection portion as a boundary. 2. The toothbrush according to claim 1, wherein θ is an inclination angle formed by an axis connecting a central portion of the head end and a central portion of the rear end of the head portion with respect to a central axis in a longitudinal direction of the head portion. A toothbrush characterized in that the tip end side of the head portion can be bent and moved in the range of θ = 1 ° to 85 °. 3. The toothbrush according to claim 1, wherein the area of the head portion that bends and moves is 10 to 90% of the area of the entire head portion. 4. The toothbrush according to claim 1, wherein the area or volume of the connecting portion is 1.0% to 40% of the total area or volume of the head portion. 5. The toothbrush according to claim 1, wherein the ratio of the minimum thickness of the hard resin to the thickness of the head portion at the connection position is 0. 5 when the connection portion is formed by combining a soft resin and a hard resin. A toothbrush comprising 5% to 50%. 6. The toothbrush according to claim 1, wherein a brush or a bunch of brushes is implanted also in the connecting portion. 7. The toothbrush according to claim 1, wherein the MFR of the hard resin constituting the head portion is 5 to 70 g / 1.
0 min (Test method JIS K7210, Test temperature 230
And a test load of 2.16 kg / cm ² ).