JP7021936B2 - Intertooth cleaning tool - Google Patents

Description

The present invention relates to an interdental cleaning tool.

Conventionally, an interdental cleaning tool for cleaning the interdental space has been known. For example, Patent Document 1 discloses an interdental cleaning tool including a base portion having a shape extending in a specific direction and a cleaning portion made of an elastomer. The base has a shaft portion having a shape that can be inserted between teeth and a grip portion having a shape that can be gripped by a finger. The cleaning portion has a shape that covers a part of the outer peripheral surface of the shaft portion (a portion including the tip portion).

The base is formed of a composite material (a material in which a reinforcing material is added to a synthetic resin) containing a synthetic resin such as polypropylene and a reinforcing material such as glass fiber. The reinforcing material is added to increase the strength of the shaft portion (particularly the buckling load). The reinforcing material is oriented so that the longitudinal direction of the reinforcing material coincides with the axial direction of the shaft portion. Specifically, the composite material is filled in the mold having a space corresponding to the base portion along the axial direction of the shaft portion, so that the longitudinal direction of the reinforcing material coincides with the axial direction of the shaft portion. Oriented to. The orientation of this reinforcing material contributes to the improvement of the buckling load of the shaft portion.

International Publication No. 2013/176297

In the interdental cleaning tool as described in Patent Document 1, the buckling strength of the shaft portion is effectively increased, but the shaft portion is relatively easy to break when a bending load is applied to the shaft portion. .. This becomes remarkable especially when cleaning the space between the back teeth with an inter-tooth cleaning tool. Specifically, when cleaning between the teeth of the back teeth, the shaft portion is inserted toward the back teeth side in the oral cavity, the tip portion of the shaft portion comes into contact with the side surface of the back teeth, and then the shaft portion is between the teeth of the back teeth. The shaft part is pushed in as it is so that it can be inserted into. Therefore, the shaft portion has a curved shape while being inserted between the back teeth. Then, when cleaning from that state, the grip portion is operated so that the portion of the shaft portion located between the back teeth serves as a fulcrum and the shaft portion bends in various directions. As a result, the shaft portion often breaks at or near the portion serving as the fulcrum. Therefore, the shaft portion is required to be bent.

An object of the present invention is to provide an interdental cleaning tool capable of suppressing bending of a shaft portion.

As a result of diligent studies to solve the above problems, the present inventors have found that the reinforcing material is released from the synthetic resin in the shaft portion made of the composite material containing the synthetic resin and the reinforcing material (the reinforcing material is a synthetic resin). It was found that the fact that the shaft portion is hardly adhered to the shaft portion is the cause of the shaft portion being easily broken when the shaft portion is bent. Specifically, when observing the cross section of the shaft portion, since the reinforcing material is released from the synthetic resin, the cross-sectional area of the shaft portion that contributes to the moment of inertia of area becomes smaller by that amount. In other words, most of the bending load acting on the shaft portion is handled only by the portion made of synthetic resin. Therefore, when the shaft portion is made of a composite material containing a reinforcing material, the bending stress generated in the shaft portion is larger when the bending load is applied to the shaft portion than when the shaft portion is made of only synthetic resin. Therefore, the shaft portion is easily broken.

Therefore, the present inventors can obtain a shaft portion that is hard to break (flexible) against a bending load while effectively increasing the buckling load by increasing the adhesiveness between the reinforcing material and the synthetic resin. I came up with something.

The present invention has been made based on the above viewpoints. Specifically, the present invention includes an interdental cleaning tool having a base having a shaft portion having a shape capable of being inserted between teeth, and the base portion is an anhydride of a polyolefin and an unsaturated carboxylic acid. Provided is an interdental cleaning tool formed of a composite material containing a copolymer having the above as a constituent unit and a reinforcing material made of glass.

In this interdental cleaning tool, since the polar group of the unsaturated carboxylic acid anhydride is bonded to the reinforcing material made of glass, the copolymer containing polyolefin and the reinforcing material are bonded. Therefore, as compared with the case where the composite material does not contain the unsaturated carboxylic acid anhydride, the area of the shaft portion that bears the bending load when the bending load is applied to the shaft portion becomes larger (from the polyolefin of the reinforcing material). (Because the liberation is reduced), the shaft portion becomes supple and the bending of the shaft portion is suppressed.

Further, in the interdental cleaning tool, the unsaturated carboxylic acid anhydride is preferably an unsaturated dicarboxylic acid anhydride, and among the unsaturated dicarboxylic acids, itaconic acid anhydride, maleic anhydride, fumaric acid anhydride, and citracon anhydride. The acid and mesaconic anhydride are preferable, and maleic anhydride is more preferable.

In this embodiment, the bond between the reinforcing material and the polyolefin becomes stronger, so that the shaft portion becomes more supple.

Further, in the interdental cleaning tool, the polyolefin is preferably polypropylene. Examples of the polyolefin include polyethylene and the like in addition to polypropylene.

The acid value of the copolymer is preferably 0.1 or more and 15 or less.

By doing so, the bending of the shaft portion is more reliably suppressed. Specifically, when the oxidation is 0.1 or more, it is suppressed that the amount of unsaturated carboxylic acid anhydride is insufficient with respect to the amount of the reinforcing material. Sufficient adhesion is ensured. When the oxidation is 15 or less, the amount of the unsaturated carboxylic acid anhydride becomes too large with respect to the amount of the reinforcing material, that is, the unsaturated carboxylic acid anhydride acts as an impurity. Is suppressed.

Further, the value obtained by multiplying the ratio of the acid value of the copolymer to the content of the reinforcing material in the composite material by 100 is preferably 0.2 or more and 300 or less.

Even in this way, the bending of the shaft portion is more reliably suppressed.

Further, the content of the reinforcing material in the composite material is preferably 5% by weight or more and 50% by weight or less.

By doing so, the rigidity of the shaft portion is effectively increased, and the flexibility of the shaft portion is ensured.

Further, in the interdental cleaning tool, the reinforcing material is preferably at least one selected from the group consisting of glass fiber, spherical glass and scaly glass.

Further, it is preferable that the interdental cleaning tool is further provided with a cleaning portion made of an elastomer, which covers the outer peripheral surface of the shaft portion and can clean the interdental space.

As described above, according to the present invention, it is possible to provide an interdental cleaning tool capable of suppressing the bending of the shaft portion.

It is a front view of the interdental cleaning tool of one Embodiment of this invention. It is a conceptual diagram of the copolymer which has the anhydride of polyolefin and unsaturated carboxylic acid as a constituent unit. It is a side view which shows the outline of the apparatus which measures the strength and the degree of bending of the shaft part of the interdental cleaning tool shown in FIG. FIG. 3 is a plan view showing a state in which the pressing tool is in contact with the interdental cleaning tool in the device shown in FIG. It is a top view which shows the state which the pressing tool presses the interdental cleaning tool in the apparatus shown in FIG. It is a graph which shows the relationship between the angle of the pressing tool and torque in Example 7. FIG. It is a table which shows the composition of Example 1 and Comparative Example 1 and various evaluations. It is a table which shows the composition and various evaluations of Examples 2-4 and Comparative Example 2. It is a table which shows the composition of Examples 5 to 11 and Comparative Example 3 and various evaluations. It is a table which shows the composition and various evaluations of Example 12 and Comparative Example 4. It is a table which shows the composition and various evaluations of Examples 13-14 and Comparative Example 5.

An interdental cleaning tool 1 according to an embodiment of the present invention will be described with reference to FIG. Note that FIG. 1 shows a group of interdental cleaning tools having a plurality of (three in FIG. 1) interdental cleaning tools 1. The inter-tooth cleaning tool 1 includes a base 10 and a cleaning unit 40.

The base portion 10 has a shaft portion 20 and a grip portion 30.

The shaft portion 20 has a shape that extends linearly along a specific direction (vertical direction in FIG. 1) and can be inserted between teeth. The shaft portion 20 has a base end portion 20a connected to the grip portion 30 and a tip portion which is an end portion on the side inserted between the teeth. In the present embodiment, the shaft portion 20 is formed in a columnar shape whose outer diameter gradually decreases from the base end portion 20a toward the tip end portion.

The grip portion 30 extends from the base end portion 20a of the shaft portion 20 so as to be separated from the shaft portion 20 along the axial direction of the shaft portion 20, and has a flat shape that can be gripped by a finger. The gripping portions 30 adjacent to each other are connected by a pair of connecting portions 32. It is preferable that each connecting portion 32 is thinner than the grip portion 30. Further, it is preferable that each connecting portion 32 has a shape that gradually becomes thinner toward each other. By doing so, it is easy to disconnect at the connecting portion 32, and it is suppressed that the connecting portion 32 is disconnected due to an impact during transportation or the like. Further, it is preferable that the boundary between the connecting portion 32 and the grip portion 30 located on one side of the connecting portion 32 is thinner than the boundary between the connecting portion 32 and the grip portion 30 located on the other side of the connecting portion 32. ..

The base 10 is formed of a composite material containing a copolymer 13 (see FIG. 2) having a polyolefin 14 and an unsaturated carboxylic acid anhydride 15 as constituent units, and a reinforcing material made of glass.

As shown in FIG. 2, the copolymer 13 has a polyolefin 14 and an unsaturated carboxylic acid anhydride 15 as constituent units. The unsaturated carboxylic acid anhydride 15 acts as a polar group, the polyolefin 14 acts as a non-polar group, and the unsaturated carboxylic acid anhydride 15 is bonded to a reinforcing material made of glass. That is, the unsaturated carboxylic acid anhydride 15 has a function of binding the polyolefin 14 and the reinforcing material. In this embodiment, polypropylene is used as the polyolefin 14. Further, maleic anhydride is used as the unsaturated carboxylic acid anhydride 15. However, the polyolefin 14 and the unsaturated carboxylic acid anhydride 15 are not limited to those described above.

As the reinforcing material, at least one selected from the group consisting of glass fiber (fibrous reinforcing material), scaly glass (plate-shaped reinforcing material) and spherical glass (glass beads) is preferably used. In this embodiment, glass fiber is used as the reinforcing material.

Further, in the present embodiment, the acid value of the copolymer 13 is determined based on the content of the reinforcing material in the composite material. That is, if the amount of the unsaturated carboxylic acid anhydride 15 is too large with respect to the content of the reinforcing material in the composite material, the unsaturated carboxylic acid anhydride 15 becomes an impurity, and conversely, the reinforcing material in the composite material If the amount of the unsaturated carboxylic acid anhydride 15 is too small with respect to the content, an effective binding force between the polyolefin 14 and the reinforcing material cannot be obtained. From this point of view, in the present embodiment, "a value obtained by multiplying the ratio of the acid value of the copolymer 13 to the content of the reinforcing material in the composite material by 100", in other words, "the content of the reinforcing material in the composite material". The "acid value when the amount (g) is 100" is set in a suitable range. The acid value is represented by the following formula (1).

100 x (content of copolymer 13 in composite material (g) x acid value) / content of reinforcing material in composite material (g) ... (1)

The acid value is preferably 0.2 or more and 300 or less, more preferably 0.29 or more and 150 or less, and further preferably 0.6 or more and 17.3 or less.

In the present embodiment, the content of the reinforcing material in the composite material is set to 5% by weight or more and 50% by weight or less, and the acid value of the copolymer 13 is set to 0.1 or more and 15 or less. The acid value of the copolymer 13 is more preferably set to 0.14 or more and 5.2 or less. By setting the content of the reinforcing material to 5% by weight or more, the strength (buckling load) of the shaft portion 20 is expected to be sufficiently improved, and the content of the reinforcing material is set to 50% by weight or less. As a result, sufficient toughness is ensured for the shaft portion 20. The molecular weight of the copolymer 13 is usually 1000 to 200,000.

The base 10 described above is formed, for example, as follows. That is, a solid material (pellet-like material) made of polypropylene (oxidized by maleic anhydride) containing 30% by weight of glass fiber is placed in a primary molding die having a space having a shape corresponding to the base 10. The base 10 is formed by pouring while melting.

Next, the cleaning unit 40 will be described. The cleaning portion 40 can cover the outer peripheral surface of the shaft portion 20 and clean the space between the teeth. The cleaning unit 40 has a cleaning unit main body 42 that covers the outer peripheral surface of the shaft portion 20, and a plurality of brush bristles 44, each of which projects from the outer peripheral surface of the cleaning unit main body 42. The cleaning portion 40 is made of an elastomer. In this embodiment, a styrene-based elastomer is used as the elastomer. Since the styrene-based elastomer has excellent compatibility with polypropylene, peeling of the cleaning portion 40 from the shaft portion 20 is effectively suppressed. Further, the strong adhesion between the cleaning portion 40 and the shaft portion 20 contributes to the suppression of the bending of the shaft portion 20 by the cleaning portion 40.

Next, a method of cleaning the space between the back teeth with the inter-tooth cleaning tool 1 will be described.

First, the interdental cleaning tool 1 is inserted toward the back teeth side in the oral cavity with the tip of the shaft portion 20 at the head. Then, after the tips of the shaft portion 20 and the cleaning portion 40 come into contact with the side surfaces of the back teeth, the shaft portion 20 is pushed in as it is so that the shaft portion 20 and the cleaning portion 40 are inserted between the teeth of the back teeth. Subsequently, the grip portion 30 is operated so that the shaft portion 20 and the cleaning portion 40 reciprocate along the teeth. At this time, although a bending load may act on the shaft portion 20, in the interdental cleaning tool 1 of the present embodiment, since the shaft portion 20 is supple, the bending of the shaft portion 20 is suppressed. Specifically, in the tooth cleaning tool 1, the polar group of the unsaturated carboxylic acid anhydride 15 is bonded to a reinforcing material made of glass. In other words, in the interdental cleaning tool 1, the polyolefin 14 and the reinforcing material are bonded to each other via the unsaturated carboxylic acid anhydride 15. Therefore, as compared with the case where the composite material does not contain the unsaturated carboxylic acid anhydride 15 (when the reinforcing material is free from the polyolefin 14), the shaft responsible for the bending load when the bending load is applied to the shaft portion 20. Since the area of the portion 20 becomes large, the shaft portion 20 becomes flexible and the bending of the shaft portion 20 is suppressed.

Further, in the tooth-to-tooth cleaning tool 1, the acid value is 0.2 or more and 300 or less. Therefore, the bending of the shaft portion 20 is more reliably suppressed. Specifically, when the acid value is 0.2 or more, it is possible to prevent the amount of the unsaturated carboxylic acid anhydride 15 from being insufficient with respect to the amount of the reinforcing material. Therefore, the polyolefin 14 and the reinforcing material are prevented from being insufficient. Sufficient adhesion with is ensured. When the acid value is 300 or less, the amount of the unsaturated carboxylic acid anhydride 15 becomes too large with respect to the amount of the reinforcing material, that is, the unsaturated carboxylic acid anhydride 15 is used as an impurity. It is suppressed from acting.

It should be noted that the above-described embodiment disclosed this time is exemplary in all respects and is not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the embodiment described above, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, titanium oxide or zinc sulfide may be added to the composite material in order to obtain the white base 10. Here, when titanium oxide is blended in the composite material, the reinforcing material (scaly glass, glass fiber, etc.) contained in the composite material is crushed when the composite material is kneaded and molded, so that the composite material has high flexibility. The shaft portion 20 is obtained. On the other hand, when zinc sulfide is blended in the composite material, crushing of the reinforcing material (glass fiber, glass flakes, etc.) in the kneading process of the composite material is suppressed, so that the shaft portion 20 having high rigidity can be obtained. The content of titanium oxide or zinc sulfide in the composite material is preferably set to about 1.5% or more and 2% or less.

For the interdental cleaning tool 1 of the above embodiment, 14 types of examples were created, and 5 types of comparative examples with respect to the above examples were created. The compositions of each Example and each Comparative Example are as shown in FIGS. 7 to 11. The scaly glass is available from Nippon Sheet Glass Co., Ltd., and the glass fiber is available from Asahi Fiber Glass Co., Ltd., Nitto Boseki Co., Ltd., Central Glass Co., Ltd., etc. Further, FIGS. 7 to 11 show three evaluations of these Examples and Comparative Examples, that is, (1) acid value, (2) strength improvement of the shaft portion 20, and (3) shaft portion. The degree of improvement in the degree of bending of 20 is shown. Hereinafter, the evaluation method of each evaluation and the result thereof will be described.

(1) Acid value The acid value was calculated based on the above formula (1). Since the unsaturated carboxylic acid anhydride 15 is not contained in each comparative example, the column of "acid value when the content (g) of the reinforcing material is 100" in each comparative example is displayed. It is zero (display of "-").

(2) Degree of Strength Improvement of Shaft 20 As shown in FIGS. 3 to 5, this measurement uses a holding member 50 capable of holding the shaft 20 and a pressing tool 60 capable of measuring torque. Made by. Specifically, in this measurement, the pressing tool 60 rotates at a rotation speed of 20 rpm around the rotating shaft O in a state where the portion of the interdental cleaning tool 1 from the tip of the shaft portion 20 to 11 mm is sandwiched by the holding member 50. While doing so, it was performed by pressing a portion (grip portion 30) of the interdental cleaning tool 1 35 mm (24 mm from the rotating shaft O) from the tip of the shaft portion 20. As shown in FIG. 3, the width of the portion of the pressing tool 60 that presses the interdental cleaning tool 1 is 5 mm.

FIG. 6 shows the test results. Note that FIG. 6 is a graph showing the test results of Example 7. The peak value of the torque in FIG. 6 was evaluated as the "strength" of the shaft portion 20. The torque measured by the pressing tool 60 decreases after reaching the peak value because the shaft portion 20 is broken. Further, a digital torque meter TNX-0.5 (manufactured by Nidec-Shimpo Co., Ltd.) was used as the holding member 50 and the pressing tool 60.

The “strength improvement degree” is the strength of the shaft portion 20 of the example when the strength of the shaft portion 20 of the comparative example containing no unsaturated carboxylic acid anhydride 15 is set to 100. That is, it is evaluated that the larger this value is, the stronger the shaft portion 20 of the embodiment is compared with the shaft portion 20 of the comparative example to be compared. In FIGS. 7 to 11, the degree of improvement in strength is indicated by a symbol. The meaning of each symbol is as follows.

-: Less than 103 B: 103 or more and less than 105 A: 105 or more and less than 110 S: 110 or more

(3) Degree of improvement in bending degree of shaft portion 20 In FIG. 6, the angle at which torque starts to be generated (the angle of the pressing tool 60 when the pressing tool 60 comes into contact with the grip portion 30) is set to 0 °, and the peak value of torque is set. Was evaluated as the "degree of bending". The reason why this angle can be evaluated as the degree of bending is as follows. That is, when cleaning the space between the back teeth with the inter-tooth cleaning tool 1, the shaft portion 20 has a curved shape while being inserted between the back teeth, and from that state, the space between the back teeth of the shaft portion 20 is formed. The grip portion 30 is operated so that the shaft portion 20 is curved in various directions with the portion located at the position as a fulcrum. Therefore, the angle at the peak value of the torque measured by the pressing tool 60 in the state where the shaft portion 20 is sandwiched by the sandwiching member 50 is evaluated as the degree of bending.

The “degree of improvement in bending degree” is the degree of bending of the shaft portion 20 of the example when the degree of bending of the shaft portion 20 of the comparative example containing no unsaturated carboxylic acid anhydride 15 is set to 100. That is, it is evaluated that the larger this value is, the greater the degree of flexibility (more supple) of the shaft portion 20 of the embodiment than that of the shaft portion 20 of the comparative example to be compared. In FIGS. 7 to 11, the degree of improvement in the degree of bending is indicated by a symbol. The meaning of each symbol is as follows.

-: Less than 103 +: 103 or more and less than 105 ++: 105 or more and less than 110 +++: 110 or more and less than 115 +++++: 115 or more and less than 120 +++++: 120 or more

From FIGS. 7 to 11, the unsaturated carboxylic acid anhydride is used as a reference for any of the comparative examples, in other words, even when the type and content of the reinforcing material made of glass in the composite material are different. It was confirmed that the inclusion of 15 increased both the strength and the degree of bending of the shaft portion 20. That is, by forming the base 10 with a composite material containing polypropylene oxidized with maleic anhydride and a reinforcing material, the interdental space having a shaft portion 20 having excellent suppleness while ensuring good buckling strength. It was shown that cleaning tool 1 was obtained.

1 Intertooth cleaning tool 10 Base 13 Copolymer 14 Polyolefin 15 Unsaturated carboxylic acid anhydride 20 Shaft part 30 Grip part 40 Cleaning part 50 Holding member 60 Pressing tool

Claims (8)

It ’s an inter-tooth cleaning tool.
Includes a base with a shaft having a shape that can be inserted between the teeth
The base is an interdental cleaning tool formed of a composite material containing a copolymer having an anhydride of polyolefin and an unsaturated carboxylic acid as a constituent unit and a reinforcing material made of glass. In the interdental cleaning tool according to claim 1,
The unsaturated carboxylic acid anhydride is maleic anhydride, an interdental cleaning tool. In the interdental cleaning tool according to claim 2,
The polyolefin is polypropylene, an interdental cleaning tool. In the interdental cleaning tool according to any one of claims 1 to 3,
An interdental cleaning tool having an acid value of 0.1 or more and 15 or less of the copolymer. In the interdental cleaning tool according to any one of claims 1 to 4.
An interdental cleaning tool in which the ratio of the acid value of the copolymer to the content of the reinforcing material in the composite material multiplied by 100 is 0.2 or more and 300 or less. In the interdental cleaning tool according to claim 5,
An interdental cleaning tool in which the content of the reinforcing material in the composite material is 5% by weight or more and 50% by weight or less. In the interdental cleaning tool according to any one of claims 1 to 6.
The reinforcing material is at least one selected from the group consisting of glass fiber, spherical glass and scaly glass, an interdental cleaning tool. In the interdental cleaning tool according to any one of claims 1 to 7.
An interdental cleaning tool made of an elastomer, which covers the outer peripheral surface of the shaft portion and further includes a cleaning portion capable of cleaning the interdental space.

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