JP4092323B2 - toothbrush - Google Patents

Description

  The present invention relates to a toothbrush using a filament made of polytrimethylene terephthalate (PTT) resin as a brush for brushing.

  In general, a conventional toothbrush uses a brush made of a synthetic resin such as a polyamide resin (nylon 6-12, nylon 6-10) or polybutylene terephthalate (PBT) resin.

  On the other hand, as a toothbrush excellent in durability, a toothbrush using a brush made of polytrimethylene terephthalate (PTT) resin (hereinafter referred to as “PTT hair”) has been proposed, but at that time, Since n-propanediol, which is a raw material for the PTT resin, was expensive, it was difficult to put it to practical use. However, in recent years, inexpensive raw materials have been supplied (see Patent Document 2), and toothbrushes using PTT bristles have come to a practical level in terms of cost.

  Polytrimethylene terephthalate (PTT) resin is a polycondensate of n-propanediol and terephthalic acid, a polymer having a linear carbon chain between polyethylene terephthalate (PET) and PBT, and its three-dimensional molecule The structure is excellent in stretch recovery and stretched with a small stress and has high recovery. Therefore, when used as a brush of a toothbrush, the opening durability of the hair is improved, and high durability as a toothbrush has been predicted. And it is shown by patent document 3 that a highly durable toothbrush can be obtained by prescribing | hanging the boiling water shrinkage rate and intrinsic viscosity of PTT hair.

JP-A-8-173244 (full text, full figure) JP-T-2001-511379 (full text, full figure) International Publication WO01 / 75200 Pamphlet

  As described above, in the case of a toothbrush using PTT hair, the durability against brushing is remarkably higher than that of a conventional toothbrush using nylon or PBT hair, and the tip of the toothbrush is used even for a long time. Since it is hard to open, there exists an advantage that a cleaning power can be maintained over a long period of time. However, since the bristles do not open, there is a drawback in that it is difficult to know when to replace the toothbrush even if the bristles wear, flutter or break due to long-term use.

  Conventionally, as a method for informing the replacement timing of a toothbrush, a cross-section of the brush has a multi-layer structure, and the color of each layer of the multi-layered brush is made different to notify the replacement time from the color change caused by the wear of the brush (special (See Kaihei 2-152406).

  However, when the multi-layered brush as described above is used as an indicator hair for notifying the replacement time, there is a problem that the cost is high, and the degree of opening of the hair tip and the change in the color of the indicator hair do not necessarily match. there were.

  According to the present invention, in a toothbrush using PTT bristle, in order to prevent the PTT bristle from being worn, raised or broken before the replacement time comes, the toothbrush can be replaced at a simple configuration. An object of the present invention is to provide a toothbrush that can be surely notified.

To achieve the above object, the present invention provides a toothbrush using a brush composed of PTT bristle, one or more selected from polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polypropylene resin, polyethylene resin. Brush made of resin (hereinafter collectively referred to as “conventional hair”)
And with using as an indicator the hair for display tooth brush preparative Toggles timing, the hair bundle by bundling a plurality of said indicator bristles, which bristles are arranged continuously over 3 bundles of tufts made of the indicator bristles, Of the hair bundles arranged in a row, the two hair bundles at least at both ends are arranged so as to be located on the outermost periphery of the head part flocking surface. The total cross-sectional area of the brush made of terephthalate resin is 95-60% . In addition, as the conventional hair to be used, a brush made of a polyamide resin (nylon 6-10, nylon 6-12) or a PBT resin is more preferable from the viewpoint of usability and durability.

  As described above, since the PTT hair is excellent in durability, the end of the hair hardly opens even after long-term use. However, the conventional hair implanted as an indicator hair has lower durability than the PTT hair, and a toothbrush is not used. The hair ends gradually open as you proceed. Therefore, it is possible to know the replacement timing of the toothbrush from the extent of the bristles of the conventional hair, and the toothbrush can be replaced before the PTT hair is worn out, crushed or broken.

  In addition, the present invention can replace the toothbrush while maintaining the cleaning power of the PTT hair for a longer period by setting the total cross-sectional area of the PTT hair to 95-60% of the total cross-sectional area of all the brushes that have been implanted. This is to ensure that the time is known.

  In the present invention, the intrinsic viscosity of the PTT bristle is set to 0.9 to 1.3 dl / g, so that the toothbrush replacement timing can be reliably notified while maintaining the cleaning power of the PTT bristle for a longer period. It is what I did.

  Furthermore, the present invention maintains the cleaning power of the PTT hair for a longer period by setting the intrinsic viscosity of the PTT hair to 1.0 to 1.2 dl / g and the boiling water shrinkage to 0.4% or less. In this way, it is possible to surely notify the timing of replacement of the toothbrush.

Here, the intrinsic viscosity η uses an Ostwald viscosity tube, and the ratio (η _sp / C) between the specific viscosity η _sp and the concentration C (g / 100 milliliters) is 35 ° C. using o-chlorophenol. And extrapolated to the following formula:

  The boiling water shrinkage is measured by the filament shrinkage (method B) defined in JIS L 1013 (1999).

According to the present invention, three or more bundles of hair consisting of indicator hairs are continuously arranged and planted, and at least two hair bundles at both ends in the continuously arranged hair bundle are arranged on the head portion planted surface. Since it is placed on the outermost periphery, it can be known when the toothbrush is replaced from the open state of the conventional hair before the PTT hair with excellent durability wears, flails, or breaks. A toothbrush made of bristles can be used safely over a long period of time. In addition, since the total cross-sectional area of the PTT hair is 95% to 60% of the total cross-sectional area of all the brushes that have been implanted, it is possible to reliably notify the timing for replacing the toothbrush while maintaining the cleaning power of the PTT hair for a longer period of time. be able to.

Hereinafter, embodiments of the toothbrush according to the present invention will be described.
Prepare PTT hair with an intrinsic viscosity of 1.1 dl / g and a thickness of 0.203 mm (8 mil) and PTT hair with an intrinsic viscosity of 0.84 dl / g and a thickness of 0.203 mm (8 mil). Two types of toothbrushes having different intrinsic viscosities were produced by flocking the flocked surface of the toothbrush head using a linear flocking machine.
(Flocked part specification)
Flocking hole diameter: 1.6mm
Number of flocked holes: 23 holes Number of flocked holes (before folding in half): 18 / hole Hair length: 9.5 mm

About these two types of toothbrushes, a stainless steel plate was wiped using a model durability tester, and a durability test was performed.
(Cleaning condition)
Load: 400g
Brush width: 40mm
Brush: 50% aqueous dentifrice solution

  Table 1 shows the test results. The test was repeated 6 times for each toothbrush, the number of broken PTT hairs was counted every fixed number of times of brushing, and the average value of the 6 tests was used as the test result.

  As is apparent from the results in Table 1, in the case of PTT hair having an intrinsic viscosity of 1.1 dl / g, there is no problem even if the number of brushes exceeds 50,000 times. In this case, the hair is broken at the time of 20,000 times of brushing. On the other hand, the conventional hair opening durability was about 10,000 to 20,000 times. Therefore, in the case of a toothbrush using PTT bristle with an intrinsic viscosity of 0.84 dl / g, when a conventional bristle is used as an indicator bristle to inform the time of replacement of the toothbrush, it breaks into a part of the PTT bristle before the tip of the indicator bristle opens It cannot be said that there is no risk of occurrence.

  Therefore, as a result of repeated experiments and researches, the present inventor has found that the tip of a conventional hair has a limiting viscosity of 0.9 to 1.3 dl / g, more preferably 1.0 to 1.2 dl / g. It has been found that the PTT hair is not broken before opening, and the cleaning power of the PTT hair can be maintained more reliably. Therefore, the intrinsic viscosity of the PTT hair is desirably 0.9 to 1.3 dl / g, more preferably 1.0 to 1.2 dl / g. If the intrinsic viscosity exceeds 1.3 dl / g, spinning cannot be performed well, which is not preferable as a brush. Therefore, the upper limit of the intrinsic viscosity is desirably 1.3 dl / g or less.

  Moreover, if the total cross-sectional area of the PTT hair is 95 to 60%, more preferably 90 to 70% of the total cross-sectional area of all the brushes that are planted, the cleaning power of the PTT hair can be maintained for a longer period of time. Is possible. If it is less than 60%, the tip of the conventional hair gradually opens by brushing, and the cleaning power of the entire toothbrush is also reduced, which is not preferable. When it is more than 95%, the conventional hair is less than 5%, and it is difficult to understand the openness of the hair tip as the indicator hair, which is not preferable.

  Although the PTT hair and the conventional hair may be mixed in the same hair bundle, it is preferable to make the hair bundles independent from each other because it is easy to understand the opening of the hair as the indicator hair.

  When either one of the PTT hair and the conventional hair is colored or when both are colored, the function as the indicator hair is easier to understand if different colors are used.

  Further, the conventional hair as the indicator hair is not a simple colored hair as described above, but a brush cross section having a multilayer structure like the brush described in JP-A-2-152406 described above, and each layer The color of each of the brushes may be made different so that the state of wear of the brushes can be notified from the change in the color or the darkness of the outer first colored layer when the brushes are worn by brushing. In this case, since a color change also occurs as the hair opens, it is easier to understand.

  The cross-sectional shape of the brush is preferably a substantially uniform cross-sectional shape, but the cross-sectional shape is not particularly limited, and besides a circular shape, an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, a star, a three-leaf clover shape, Any shape such as a four-leaf clover shape is selected as necessary. From the viewpoint of physical strength, a circular shape is more preferable.

  Further, the outer shape of the brush may be a so-called twisted shape twisted in the length direction, or a crimped shape that is uneven like a wave, in addition to a straight columnar shape.

  As for the thickness of the brush, for example, in the case of straight columnar hair having a circular cross section, the brush diameter is 0.102 to 0.305 mm (4 to 12 mil). However, it is not necessary that all the brushes have the same thickness, and within this range, for example, 0.152 mm (6 mil) and 0.178 mm (7 mil), 0.178 mil (7 mil) and 0.203 mm ( 8 mil) can be combined as appropriate in consideration of usability, usability, cleaning effect, and the like.

  Also, the PTT hair and the conventional hair may be the same thickness or different, and are appropriately selected according to the size of the toothbrush flocked portion, the flocking pattern of the brush, the flocking amount, the bristles thickness, and the like.

  Furthermore, when fixing the brush to the flocked surface of the toothbrush head, if flocking is performed so that the packing factor is 60 to 100%, a toothbrush with good fluffing can be obtained, the tooth surface is excellent in cleanability, and A toothbrush with excellent durability.

  In the case of a toothbrush in which a part of the toothbrush head portion is made of a soft resin such as a thermoplastic resin or a silicone resin, if the hair is planted so that the packing factor is 60 to 120%, even if the soft resin is used, the hair A toothbrush with good standing can be obtained, and a toothbrush excellent in the cleaning property of the tooth surface and excellent in durability can be obtained.

  The packing factor is a percentage obtained by multiplying the sum of the cross-sectional areas of the brushes planted in the flock holes by the cross-sectional area of the flock holes and multiplying by 100. However, in the case of flat-line type flocking, the area of the flocked hole is a value obtained by subtracting the area of the flat line driven into the flocked hole from the area of the flocked hole.

  When the brush tip is flat, the hair length of the brush that has been implanted is preferably 9 to 12 mm for adults and 6 to 9 mm for children. Further, the tip of the hair may be rounded or processed into a spatula shape, or the tip of the hair may be melted with heat to form a spherical shape.

  The angle of the bristles (the angle between the brush planted on the head flocked surface and the flocked surface) does not necessarily have to be perpendicular to the flocked surface, for the purpose of increasing the plaque scraping effect in a specific direction, The hair may be planted at a predetermined angle.

  There is no particular limitation on the shape of the brush at the tip of the brush, but generally it is appropriately selected from flat cutting, mountain cutting, ship bottom shape, and the like.

  The cross-sectional shape of the flocked hole is usually circular, but is not necessarily circular, and may be an indeterminate shape combining polygons such as triangles and quadrangles, straight lines, or curves in accordance with the specifications of the flocked portion.

  The material of the toothbrush handle including the toothbrush head portion is not particularly limited. For example, polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, cellulose propionate, polyurethane, polyamide, ABS and the like are used. Polypropylene is more preferable in terms of cost and dentifrice resistance.

  However, since polypropylene resin is opaque, if you want to make a toothbrush handle with high transparency, PCTA resin, which is a kind of polyester resin from Eastman, USA, has high cost and dentifrice resistance. To preferred.

  There is no limit to the method of implanting the brush into the toothbrush head. In the case of flat line type flocking, brass is used as the material of the metal piece (flat line) used in the flat line type flocking, but it may be Western-style or stainless steel. The dimension of the flat line is appropriately selected depending on the size of the flock hole.

  In addition, as a method for flocking without using a flat wire, an in-mold method in which a lower end of a bundle of hairs is heated to form a molten lump and then a molten resin is injected into a mold to produce a toothbrush (Japanese Patent Laid-Open No. 61-61). No. 268208, Japanese Patent Publication No. 9-512724), and a heat fusion method in which a bristle bundle melting portion is press-fitted into a melting toothbrush head portion and fixed (see Japanese Patent Application Laid-Open No. 60-241404). Can also be used.

As Example 1, PTT hair having a thickness of 0.203 mm (8 mil) spun using PTT resin pellets having an intrinsic viscosity of 1.28 dl / g (intrinsic viscosity 1.12 dl / g, boiling water shrinkage 0.04), A toothbrush of the present invention specification having a hair bundle arrangement as shown in FIG. 1 was prepared using a flat hair transplanter using nylon hair (nylon 6-12) having a thickness of 0.203 mm (8 mil). In FIG. 1, the hair bundle 1 indicated by white circles is PTT hair, and the hair bundle 2 indicated by black circles is nylon hair.
(Flocked part specification)
Flocking hole diameter: 1.6mm
Number of flock holes: 23 Number of flocks (before folding in half): 18 / hole Hair length: 9.0 mm

  About the toothbrush of the said Example 1, the use test by 30 adult men was done. Since the dentifrice, brushing pressure, and brushing method used differ depending on the panel, the period until the hair ends of the nylon bristle were 1 month to 3 months apart, but the toothbrush of Example 1 was made of nylon bristle Until the tip was opened and the time for replacement was notified, the PTT hair did not open with the tip of the hair loosened, and good cleaning power was maintained.

  As described above, in the toothbrush of Example 1 according to the present invention, even when the toothbrush replacement time is reached, the bristles hardly open, the initial cleaning power is maintained, and no breakage or the like occurs. Could be used safely for a long time.

FIG. 2 shows another embodiment of the toothbrush according to the present invention.
(A) shows a second embodiment, an example in which a hair bundle 2 made of nylon bristles is arranged in an arc so as to cross the head portion, and (b) shows a third embodiment, made of nylon bristles. An example in which the hair bundles 2 are arranged on both sides of the head part, (c) shows a fourth embodiment, and is an example in which the hair bundles 2 made of nylon hair are arranged in two rows in the front and back so as to cross the head part. The results similar to those of the first example were obtained for each of these examples.

1 shows a first embodiment of a toothbrush according to the present invention and is a schematic plan view of a head portion. FIG. The other example of the toothbrush which concerns on this invention is shown, (a) is the schematic plan view of the head part of 2nd Example, (b) is the schematic plan view of the head part of 3rd Example, ( c) is a schematic plan view of a head portion of a fourth embodiment.

Explanation of symbols

1 Hair bundle made of PTT hair 2 Hair bundle made of nylon hair (indicator hair)

Claims (3)

In a toothbrush using a brush made of polytrimethylene terephthalate resin,
Polyamide resin, polyethylene terephthalate resin, using polybutylene terephthalate resin, polypropylene resin, a brush comprised of one or more resins selected from polyethylene resin, as an indicator bristles for Toggles timing display preparative tooth brush,
A plurality of the indicator hairs are bundled to form a hair bundle, and three or more bundles of the indicator hairs are continuously arranged and planted, and at least two hairs at both ends in the continuously arranged hair bundle Place the bundle so that it is located on the outermost circumference of the head flocking surface,
A toothbrush characterized in that the total cross-sectional area of a brush made of polytrimethylene terephthalate resin is 95 to 60% of the total cross-sectional area of all brushes planted . The toothbrush according to claim 1 , wherein the brush made of polytrimethylene terephthalate resin has an intrinsic viscosity of 0.9 to 1.3 dl / g. 2. The toothbrush according to claim 1 , wherein the brush made of polytrimethylene terephthalate resin has an intrinsic viscosity of 1.0 to 1.2 dl / g and a boiling water shrinkage of 0.4% or less.

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