JP2011200351A - Tapered bristle and brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tapered bristle having excellent cleaning property and durability while keeping excellent touch and flexibility characteristic to a tapered bristle made of a polyamide resin, and to provide a brush using the same.SOLUTION: The tapered bristle 1 has a tapered part at least at one end of a cut bristle made of a synthetic resin monofilament, and has a core/sheath composite structure in which the core part is made of a polyamide resin and the sheath part is made of a polyester resin. The tapered part 2 is composed of a core tapered part 4 in which the core part is exposed acutely, and a sheath tapered part 5interposed between the core tapered part 4 and a straight part. The length of the core tapered part 4 is 50 to 95% of the length of the tapered part.

Description

  The present invention relates to a tapered bristle excellent in cleanability and durability while maintaining the excellent tactile sensation and flexibility unique to a tapered bristle made of polyamide resin, and a brush using the tapered bristle.

  Conventionally, synthetic resin monofilaments are mainly used for brush bristle materials because they are inexpensive and can be easily processed.

  Particularly in recent years, various functions have been required for brushes, and hair materials used for brushes have been proposed having various forms and functions.

For example, a toothbrush bristle with a tapered bristles (see, for example, Patent Document 1) is easy to remove plaque in a narrow portion because the bristles easily enter between teeth, and also has excellent tactile sensation. It has become the mainstream of dental care products because it exhibits specific functions not found in conventional toothbrush bristle, such as a massage effect on gums.
The conventional tapered bristle for toothbrushes often uses polybutylene terephthalate as a constituent material because the tapered shape can be easily obtained by dissolving the tip of the synthetic resin monofilament with an alkaline solution.

  However, although polybutylene terephthalate is a relatively soft material among polyester-based resins, it may feel somewhat hard as a constituent material of a tapered bristle, especially when it is used for a tapered bristle for a toothbrush. There are many users who are irritated and feel uncomfortable.

  For this reason, there is a method to make the tapered bristle diameter narrower and soften the hair and softness to the gums, but the diameter is so thin that it will open during repeated use, making it impossible to use immediately. However, since it is soft, the force for scraping off dirt accumulated in the gap between the teeth and the gap between the teeth and the gums is weakened, and there is a problem that the cleaning property is deteriorated.

  Therefore, a tapered bristle made of a polyamide resin in which a hair tip is processed into a taper shape using a mixed solvent of phosphoric acid and at least one of polyhydric alcohols is known (for example, see Patent Document 2). Tapered bristle made of polyamide resin is softer than polyester resin, so it has enough flexibility without reducing its diameter. It is very useful for people who need massage care due to its weak touch, but because the entire bristle is soft, it is not as clean as a polyester resin tapered bristle. On the other hand, since the polyamide-based resin absorbs water more easily than the polyester-based resin, there is a problem that the hair opens during repeated use and cannot be used immediately.

  For this reason, the tapered bristle made of polyamide resin is not suitable for applications such as toothbrushes that are prone to open hair, and most of them were used for limited brush applications such as makeup brushes and paint brushes. In order to make use of the excellent tactile sensation and flexibility unique to tapered bristle made of polyamide resin for brush applications other than makeup brushes and paint brushes, efforts have been made to develop them.

Japanese Patent No. 3145213 Japanese Patent Laid-Open No. 10-168748

  An object of the present invention is to provide a tapered bristle excellent in cleanability and durability and a brush using the same while maintaining the excellent tactile sensation and flexibility unique to the tapered bristle made of polyamide resin.

  In order to achieve the above object, according to the present invention, a tapered bristle having a tapered portion at least one end of a cut bristle made of a synthetic resin monofilament, wherein the synthetic resin monofilament has a polyamide portion as a core portion and a polyester portion as a sheath portion. A core-sheath composite structure made of a resin, wherein the taper portion includes a core taper portion with a core portion exposed sharply, and a sheath taper portion interposed between the core taper portion and the straight portion, and the core A tapered bristle is provided in which the length of the tapered portion is in the range of 50 to 95% of the length of the tapered portion.

In the present invention,
The polyamide-based resin is made of at least one of nylon 610 and / or nylon 612;
It is further preferable that the polyester resin is made of at least one of polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate.

  The brush of the present invention is characterized in that any one of the above-described tapered bristle is used for at least a part of the hair material.

  ADVANTAGE OF THE INVENTION According to this invention, the taper bristle excellent in the cleaning property and durability, and the brush using the same can be obtained, maintaining the outstanding tactile property and softness | flexibility peculiar to the taper bristle made from a polyamide-type resin.

(A) is an enlarged schematic diagram which shows an example of the tapered bristle of this invention, (b) and (c) are sectional drawings in the line II and the line II-II of the tapered bristle 1, respectively.

  Hereinafter, the present invention will be specifically described with reference to the drawings.

  FIG. 1A is an enlarged schematic view showing an example of a tapered bristle of the present invention, where 1 is a tapered bristle, 2 is a tapered portion, 3 is a straight portion, 4 is a core tapered portion, and 5 is a sheath tapered portion. FIGS. 1B and 1C are cross-sectional views of the tapered bristle 1 taken along lines I-I and II-II, where 6 indicates a core portion and 7 indicates a sheath portion.

  As shown in FIG. 1, a tapered bristle 1 of the present invention is a tapered bristle having a tapered portion 2 at least at one end of a cut bristle made of a synthetic resin monofilament, and the synthetic resin monofilament has a core portion 6 of a polyamide resin, The sheath portion 7 has a core-sheath composite structure made of a polyester resin, and the taper portion 2 is interposed between the core taper portion 4 with the core portion sharply exposed, and the core taper portion 4 and the straight portion 3. The length of the core taper portion 4 is in the range of 50 to 95% of the length of the taper portion 2 (the total of the core taper portion 4 and the sheath taper portion 5). Is.

  In other words, since the tapered bristle 1 of the present invention has a polyester resin harder than the polyamide resin around the core portion 6 made of the polyamide resin, the tapered bristle 1 has excellent characteristics unique to the polyamide resin. While maintaining tactile sensation and flexibility, it is possible to improve the deficiency of cleaning and durability, which were the disadvantages of the tapered bristle made of polyamide resin.

  Here, the polyamide-based resin used for the core portion 6 is not particularly limited. For example, nylon 6, nylon 66, nylon 610, nylon 612, nylon 46, nylon 410, nylon 56, nylon MXD6, nylon 11 , Nylon 12, nylon 6.66 copolymer, nylon 6.12 copolymer, and blends of two or more of these. Among them, nylon 610 and nylon 612 have low water absorption. Since the physical characteristics are sufficient, it is particularly suitable as the tapered bristle 1 of the present invention.

  On the other hand, the polyester resin used for the sheath portion 7 is not particularly limited, but polyethylene terephthalate (hereinafter referred to as PET), polybutylene terephthalate (hereinafter referred to as PBT), polyethylene naphthalate, polypropylene terephthalate (hereinafter referred to as PET). , PPT), polymethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate, and the like. Among them, there are sufficient physical properties. In particular, PET, PBT, and PPT are suitable as the tapered bristle 1 of the present invention because the core portion 6 can be easily exposed by dissolving.

  The polyester resin used in the sheath portion 7 can contain other dicarboxylic acid components and diol components as copolymerization components as long as the object of the present invention is not impaired. For example, the dicarboxylic acid component As terephthalic acid, isophthalic acid, phthalic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, benzophenone dicarboxylic acid, phenylindane dicarboxylic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, cyclohexane dicarboxylic acid and Decalin dicarboxylic acid and the like, and examples of the diol component include ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, Aliphatic glycols such as tylene glycol, neopentylene glycol, cyclohexanediol, cyclohexanedimethanol, o-xylylene glycol, p-xylylene glycol, m-xylylene glycol, 1,4-bis (2-hydroxyethoxy) benzene 1,4-bis (2-hydroxyethoxyethoxy) benzene, 4,4′-bis (2-hydroxyethoxy) biphenyl, 4,4′-bis (2-hydroxyethoxyethoxy) biphenyl, 2,2-bis [ 4- (2-hydroxyethoxy) phenyl] propane, 2,2-bis [4- (2-hydroxyethoxyethoxy) phenyl] propane, 1,3-bis (2-hydroxyethoxy) benzene, 1,3-bis ( 2-hydroxyethoxyethoxy) benzene, 1,2-bis 2-hydroxyethoxy) benzene, 1,2-bis (2-hydroxyethoxyethoxy) benzene, 4,4′-bis (2-hydroxyethoxy) diphenyl sulfone, 4,4′-bis (2-hydroxyethoxyethoxy) diphenyl Examples include aromatic glycols such as sulfones, and diphenols such as hydroquinone, 2,2-bis (4-hydroxyphenyl) propane, resorcin, catechol, dihydroxynaphthalene, dihydroxybiphenyl, and dihydroxydiphenyl sulfone. Two or more types can be selected and used as appropriate.

  Furthermore, in the tapered bristle 1 of the present invention, in addition to particles such as various inorganic particles, various metal particles and cross-linked polymer particles, a known anti-resisting material may be used as long as it does not inhibit the effects of the present invention. Oxidants, light-proofing agents, anti-glare agents, ion-exchange agents, anti-coloring agents, anti-static agents, various coloring agents, waxes, silicone oils, various surfactants, various reinforcing fibers, etc. can be added as appropriate. It is.

  Moreover, the length of the core taper part 4 formed in the one end or both ends of the tapered bristle 1 of this invention needs to exist in the range of 50 to 95% of the length of the taper part 2, and also 70-92. % Is more preferable.

  This is an important requirement that not only affects the tactile sensation and flexibility of the tapered bristle 1 but also affects the cleanability and durability. The length of the core tapered portion 4 is longer than the length of the tapered portion 2. Is less than the above range, since the proportion of the polyester-based resin that is the constituent material of the sheath portion 7 in the tapered bristle 1 is increased, the cleaning property and durability are improved, but the entire tapered bristle 1 is hardened, Tactile sensation and flexibility tend to be impaired.

Conversely, when the length of the core taper portion 4 exceeds the above range with respect to the length of the taper portion 2,
Since the ratio of the polyamide-based resin, which is a constituent material of the core portion 6, to the tapered bristle 1 is increased, it is easy to obtain excellent tactile sensation and flexibility unique to the polyamide-based resin, but the entire tapered bristle 1 is softened. The cleaning property is liable to be deteriorated, and further, when used for a brush, the opening of the hair tends to occur, and the durability tends to be insufficient.

  Here, the manufacturing method of the tapered bristle of this invention is demonstrated.

  The method for producing the tapered bristle 1 of the present invention is not particularly limited. As a general method, a synthetic resin monofilament is spun using a known composite melt spinning machine, and the tip of the cut bristle is chemically reduced. The method of tapering by the method is mentioned.

  Specifically, in the case of producing a tapered bristle 1 using nylon 610 for the core 6 and PBT for the sheath 7, as an example, first, nylon 610 and PBT are respectively supplied to the composite melt spinning machine, After melt-kneading in a melt spinning machine, a synthetic resin melt is coextruded from the composite die.

  During melt spinning, the ratio of the core portion 6 and the sheath portion 7 can be changed by adjusting the discharge amount of nylon 610 and PBT, and the taper taper portion 4 can be formed to a desired length during taper processing. Can be adjusted.

  Further, when used as a brush, there is a possibility that the core portion 6 and the sheath portion 7 may be peeled off. Therefore, the polyamide-based resin that is the constituent material of the core portion 6 is added to the polyester-based material that is the constituent material of the sheath portion 7. Add a resin or a polyamide-based resin, which is a constituent material of the core portion 6, to the polyester-based resin, which is a constituent material of the sheath portion 7, within a range that does not impair the effects of the invention, and suppress peeling of the core portion 6 and the sheath portion 7 It is also possible to do.

  Furthermore, the cross-sectional shape of the synthetic resin monofilament used in the tapered bristle 1 of the present invention is not particularly limited, and the core portion 6 and / or the sheath portion 7 may have an irregular cross-sectional shape other than circular, for example, hollow, The shape may be a flat shape, a square shape, a half moon shape, a triangle shape, a polygon shape having five or more corners, a multi-leaf shape, a dock bone shape, and a saddle shape.

  Thereafter, the co-extruded synthetic resin melt is cooled and solidified in a cooling bath, and then stretched and heat set to form a synthetic resin monofilament.

  Then, the obtained synthetic resin monofilament is cut into a desired length to form a cut bristle. First, the cut bristle is immersed in an alkaline solution to dissolve the sheath 7 on the tip side, and the core 6 is exposed. .

  Then, in order to sharpen the exposed core part 6 and form the core taper part 4 by washing once, the core part 6 is dissolved by subsequently immersing in an acidic solution.

The tapered bristle 1 thus obtained has a tapered portion 2 composed of a core tapered portion 4 and a sheath tapered portion 5 in which the core portion 6 is sharply exposed as shown in FIG.

  The tapered bristle 1 is used for various brushes such as toothbrushes, hair brushes, body brushes, cleaning brushes, makeup brushes, paint brushes, and various industrial brushes such as roll brushes, wheel brushes, cup brushes, and niblet brushes. .

  Especially when used in a toothbrush, the tapered bristle 1 of the present invention has excellent tactile sensation and flexibility unique to polyamide resin tapered bristle, so it is extremely useful for people who need massage care due to weak gums. In addition, sufficient cleaning properties can be obtained and the durability is also excellent, so that it is possible to obtain features such as that the hair is not easily opened even if it is repeatedly used.

  Hereinafter, the tapered bristle of the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

In addition, a toothbrush was actually produced and used for tactile evaluation and durability evaluation. The specifications of the toothbrush are as follows.
Base: Made of ABS (9mm × 22mm)
Number of flocked holes: 34 Number of flocked hairs: 20 per one hole Length: 10mm

[Tactile evaluation]
The tactile sensation of the tapered bristle was evaluated by the following three stages by having 20 monitors actually brush their teeth.
1: Tactile feel equivalent to that of a conventional tapered bristle made of polyamide resin,
2: Although it lacks tactile sensation than the conventional tapered bristles made of polyamide resin, it was soft without a tingling sensation.
3: There was tingling and lacked tactile sensation.

[Cleanability]
Plaque stain solution (plaque check solution) is uniformly attached to the upper surface of a 10 mm cubic acrylic plate, and using the created brush, the upper surface of the acrylic plate is subjected to a vertical load of 350 g, an amplitude length of 30 mm, and an amplitude speed of 180. Brushing was performed for 3 minutes under the condition of reciprocation / minute, and the area of the removed plaque staining solution was measured. And the removal rate (%) was calculated | required from the adhesion area of the plaque staining liquid before brushing, and the area of the removed plaque staining liquid. A higher removal rate (%) indicates better cleaning properties.

[Durability evaluation]
A toothbrush was pressed against a stainless steel plate having irregularities on the surface with a vertical load of 500 g, and slid 20,000 times while applying 37 ° C. warm water. Then, about the state of a toothbrush, when the flocking width of the toothbrush before sliding is a (mm), and the flocking width of the toothbrush after sliding 20,000 times is b (mm), 100 × (b−a) / a The value calculated in (3) was defined as the hair opening rate (%). It shows that it is a toothbrush with high durability, so that the numerical value of this open ratio (%) is small.

[Example 1]
Nylon 610 pellets (CM2001 manufactured by Toray Industries, Inc.) and PBT pellets (Torcon 1200S manufactured by Toray Industries, Inc.) were used as raw materials.
Each synthetic resin pellet was supplied to a composite melt spinning machine so that nylon 610 was a core and PBT was a sheath, melted and kneaded in the melt spinning machine, and then a synthetic resin melt was coextruded from the composite die.

  Subsequently, the melt of the co-extruded synthetic resin was cooled and solidified in a cooling bath, and then stretched and heat set to obtain a synthetic resin monofilament having a diameter of 0.2 mm (core portion diameter 0.17 mm). .

  Next, the obtained synthetic resin monofilament is cut, and the sheath at both ends of the cut bristle is dissolved with an aqueous sodium hydroxide solution to expose the core, and then washed and further dissolved with an aqueous formic acid solution. Thus, a tapered bristle having a core taper portion and a sheath taper portion was obtained.

[Example 2]
A tapered bristle was obtained by the same production method as in Example 1 except that the discharge amount of nylon 610 and PBT was adjusted and melt spinning was performed so that the diameter of the core was 0.11 mm.

[Example 3]
A tapered bristle was obtained by the same manufacturing method as in Example 1 except that the discharge amount of nylon 610 and PBT was adjusted and melt spinning was performed so that the core portion had a diameter of 0.185 mm.

[Example 4]
A tapered bristle was obtained by the same manufacturing method as in Example 1 except that PET pellets (T301T manufactured by Toray Industries, Inc.) were used instead of PBT pellets.

[Example 5]
Tapered bristle was obtained by the same manufacturing method as in Example 1 except that PPT pellets (CERRERA CP513000 manufactured by Shell Chemicals) were used instead of PBT pellets.

[Example 6]
A tapered bristle was obtained by the same manufacturing method as in Example 1 except that nylon 612 pellets (Daiamide D18 manufactured by Daicel-Evonik) were used instead of nylon 610 pellets.

[Comparative Example 1]
Nylon 610 pellets were supplied to a melt spinning machine, melted and kneaded in the melt spinning machine, and then a synthetic resin melt was extruded from the die.

  Subsequently, the melt of the extruded synthetic resin was cooled and solidified in a cooling bath, and then stretched and heat set to obtain a synthetic resin monofilament having a diameter of 0.2 mm made of only nylon 610.

  Next, the obtained synthetic resin monofilament was cut, and the cut bristle was further immersed in a formic acid aqueous solution to dissolve both ends thereof to obtain a tapered bristle having tapered shapes at both ends.

[Comparative Example 2]
The PBT pellets were supplied to a melt spinning machine, melt-kneaded in the melt spinning machine, and then a synthetic resin melt was extruded from the die.

Subsequently, the melt of the extruded synthetic resin was cooled and solidified in a cooling bath, and then stretched and heat set to obtain a synthetic resin monofilament having a diameter of 0.2 mm made of only PBT.
Next, the obtained synthetic resin monofilament was cut, and the cut bristle was further immersed in an aqueous sodium hydroxide solution to dissolve both ends thereof, thereby obtaining a tapered bristle having tapered shapes at both ends.

[Comparative Example 3]
A tapered bristle was obtained by the same manufacturing method as in Example 1, except that the discharge amount of nylon 610 and PBT was adjusted and melt spinning was performed so that the core had a diameter of 0.08 mm.

  Table 1 shows the evaluation results of the bristle material for brushes obtained in the above Examples and Comparative Examples.

  As is clear from the results shown in Table 1, the tapered bristle (Examples 1 to 6) of the present invention is a tapered bristle or a tapered taper portion in which the length of the tapered taper portion is made of only a polyamide resin or a polyester resin. Compared to bristle (Comparative Examples 1 to 3), it was excellent not only in tactile sensation and flexibility but also in cleanability and durability.

  Since the tapered bristle of the present invention has excellent tactile sensation, flexibility, cleanability, and durability, in addition to various brushes such as toothbrushes, hair brushes, body brushes, cleaning brushes, makeup brushes, paint brushes, rolls It can be used for various industrial brushes such as brushes, wheel brushes, cup brushes, and niblet brushes. Especially when used for toothbrushes, it has excellent touch and flexibility unique to polyamide resin tapered bristle. It is extremely useful for people who need massage care because it is weak, and it has not only sufficient cleaning but also excellent durability, so that it is difficult to open hair even after repeated use. can get.

DESCRIPTION OF SYMBOLS 1 Tapered bristle 2 Tapered part 3 Straight part 4 Core taper part 5 Sheath taper part 6 Core part 7 Sheath part

Claims (5)

A tapered bristle having a tapered part at least one end of a cut bristle made of a synthetic resin monofilament, wherein the synthetic resin monofilament has a core-sheath composite structure in which a core part is made of a polyamide-based resin and a sheath part is made of a polyester-based resin, The taper portion includes a core taper portion with a core portion exposed sharply and a sheath taper portion interposed between the core taper portion and the straight portion, and the length of the core taper portion is 50 times the length of the taper portion. Tapered bristle characterized by being in the range of ~ 95%. The tapered bristle according to claim 1, wherein the polyamide-based resin is made of at least one of nylon 610 and / or nylon 612. The tapered bristle according to claim 1 or 2, wherein the polyester resin is made of at least one of polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate. A brush using the tapered bristle according to claim 1 as at least a part of a bristle material. The brush according to claim 4, wherein the brush is a toothbrush.

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