JP6924994B2 - Bristles for brushes and brushes using them - Google Patents

Description

The present invention relates to a brush bristle material suitable for various brushes including a toothbrush and a brush using the same.

Conventionally, a technique of using a synthetic fiber monofilament as a hair material for a brush is widely known. In a brush using such a bristle material for a brush, for example, a toothbrush, the cleaning effect of the teeth by the bristles and the soft touch feeling that does not damage the object to be cleaned and the massage effect such as gums are excellent in a well-balanced manner. Is desired.

However, it may be difficult to meet such a requirement if the brush bristles are formed of a single material monofilament up to the bristles. That is, in the case of a monofilament made of a single material up to the tip of the bristles, if the bristles for the brush are made thicker, the brush becomes stronger and the cleaning effect on the flat surface of the teeth and the massage effect such as gums are enhanced. However, on the contrary, the cleaning effect between the teeth may be reduced, the tactile sensation to the gums and the like may become too strong, and the gums and the like may be easily damaged.

In addition, in the case of a monofilament made of a single material up to the tip of the bristles, if the bristles for the brush are made thinner, the cleaning effect between the teeth can be enhanced, but the waist of the bristles for the brush becomes weaker over the entire length, and the gums There is a risk that the massage effect of the hair material itself will be reduced, and the durability of the hair material itself will be reduced.

Cleaning and cleaning brushes in other fields have roughly the same problems.

Therefore, in order to achieve both an excellent cleaning effect and the property of not easily damaging the object to be cleaned, Kaijima composite fiber is used as the hair material for the brush, and the sea island component is used at the root of the hair material when used for the brush. A brush bristle material having an integrated composite fiber structure and a structure in which a large number of islands are exposed and split at the tip has been proposed (Patent Document 1). By using this bristle material for brushes, it is possible to achieve both an excellent cleaning effect and the feature of not easily damaging the object to be cleaned in a well-balanced manner, and the thin island fibers at the exposed tip make it soft to the touch. It is possible to obtain.

However, the brush bristle material proposed in Patent Document 1 has the following problems. That is, since the islands are distributed over the entire cross-sectional area of the sea-island composite fiber used as the bristle material for brushes and the islands are exposed at the tip of the bristle material, they are actually used for toothbrushes and the like. When used, when an external force such as friction is applied to the exposed island, the sea part that supports the exposed island at the root of the hair material may tear depending on the magnitude of the external force, resulting in poor durability. The problem remains that it may be sufficient.

By the way, apart from the above-mentioned problems related to the conventional brush hair material, recently, a technique for producing a sea-island composite fiber capable of forming the distribution state of the islands and the cross-sectional shape of the islands into various forms has been proposed. (Patent Documents 2 to 4). According to this proposed technology, it is possible to virtually freely design the size and arrangement of islands with respect to the sea, cross-sectional shape, arrangement density, etc. in the sea-island composite fiber, and it is possible to meet various demands in various fields. When it becomes possible, there are great expectations.

Japanese Unexamined Patent Publication No. 3-99604 Japanese Unexamined Patent Publication No. 2011-174215 Japanese Unexamined Patent Publication No. 2012-127022 Japanese Unexamined Patent Publication No. 2013-14872

Therefore, the subject of the present invention focuses on the excellent features and remaining problems of the brush hair material as described in the conventional patent document 1, and is substantially free of the recently proposed mainly Shimabe. Focusing on the manufacturing technology of Kaijima composite fiber that can be designed in Japan, we will provide brush bristle materials that do not damage the object to be cleaned, have excellent cleanability, and have excellent durability, and brushes using them. It is in.

In order to solve the above problems, the hair material for brushes according to the present invention is for brushes in which islands at one end or both ends in the longitudinal direction of a sea-island composite fiber made of two or more kinds of resins having different chemical dissolution rates are exposed. In the hair material, the outer peripheral surface forming portion forming the outer peripheral surface of the sea island composite fiber is composed of only the sea portion, and the island portion of the sea island composite fiber is the outer peripheral surface in the cross section of the sea island composite fiber. It is characterized in that it is unevenly distributed in a portion closer to the central portion other than the forming portion.

In such a brush hair material according to the present invention, one end or both ends in the longitudinal direction of the Kaijima composite fiber (as described later, when the brush hair material is used for a brush, one end of the hair material is the tip of the hair. (There are cases where both ends are bristles) and the islands are exposed to the brush bristles structure, so that the bristles are in direct contact with the object to be cleaned. Only the thin islands of the composite fiber exposed at the tip are formed, and the islands are supported by the sea part of the composite fiber at the root. It is configured so that excellent cleanability is exhibited even for small parts that are difficult to clean, such as between teeth, and it is the exposed islands that are weak in contact with the object to be cleaned. Is not easily damaged and gives a soft touch. In addition, since only multiple (many) thin islands are in direct contact with the object to be cleaned, it not only scrapes dirt out of the area to be cleaned, but also has the function of entwining it, making it even better for cleaning. Sexual expression is possible. The outer peripheral surface forming section that forms an outer peripheral surface of the sea-island composite fibers are composed only of the sea portion and the island portion of the sea-island composite fibers, in cross-section of the該海island composite fibers, the central portion other than the outer peripheral surface forming section Due to the uneven distribution in the closer part, the island part near the outer peripheral surface forming part has the outer peripheral surface forming part having a certain thickness or more in the root part of the exposed island part and the vicinity part (the part on the composite fiber side). It will be covered by the sea part to be formed, and when an external force is applied to the exposed island part, the sea part supporting the exposed island part will be prevented from tearing due to the external force, and the durability of the brush hair material will be improved. It will be greatly improved. In other words, the islands of the sea-island composite fiber are unevenly distributed in the cross section of the sea-island composite fiber at a portion closer to the central portion other than the outer peripheral surface forming portion formed by the sea portion having a certain thickness or more. Since the unevenly distributed islands are exposed at the tip of the hair material, the exposed islands do not easily damage the object to be cleaned, and while taking advantage of the excellent cleaning effect, they are thicker than a certain thickness. Excellent durability is realized by the outer peripheral surface forming portion composed of the sea part.

In the hair material for brushes according to the present invention, in order to more reliably exhibit the excellent durability of the outer peripheral surface forming portion, the thickness of the sea portion constituting the outer peripheral surface forming portion exhibits the excellent durability. It is preferable that the value is more than sufficient. In order to achieve this, the ratio Ts / Di of the diameter Di of the island portion closest to the outer peripheral surface forming portion and the thickness Ts of the sea portion of the outer peripheral surface forming portion in the cross section of the sea island composite fiber is 1.2. The above is preferable. As a result, excellent durability is more reliably realized by the outer peripheral surface forming portion formed of the sea portion having a predetermined thickness or more. Ts / Di is preferably 1.5 or more, more preferably 2.0 or more.

Further, in the brush hair material according to the present invention, the exposed length of the island portion exposed at one end or both ends in the longitudinal direction of the sea-island composite fiber is preferably in the range of 0.5 to 10 mm. , More preferably in the range of 1 to 5 mm. If the exposed length of the islands is shorter than 0.5 mm, it is difficult to obtain excellent cleanability for fine parts such as between teeth due to the exposed islands, and it is difficult to obtain a good soft touch. If the exposed length of the islands is longer than 10 mm, the exposed islands with weak waist may become too long, and the exposed islands may be deformed too much, and the cleaning effect of the exposed islands (for example, the effect of entwining dirt). Also, there is a risk that the massage effect of the teeth, etc. will be insufficient.

Further, in the hair material for a brush according to the present invention, the diameter of the island portion is preferably in the range of 1 to 20 μm, and more preferably, the diameter Di of the island portion immediately in the vicinity of the outer peripheral surface forming portion is in the range of 1 to 20 μm. It is in the range of 1 to 10 μm. If the diameter of this island portion is less than 1 μm, the exposed island portion becomes too thin and the waist of the exposed island portion becomes too weak, which may make it difficult to obtain the waist of the exposed island portion necessary for cleaning. If the diameter of the island part is larger than 20 μm, the waist of the exposed island part becomes too strong, and it may be difficult to obtain excellent cleanability for small parts such as between teeth, and it may be difficult to obtain a soft touch. There is. In the present invention, the diameter of the island portion means the diameter of the island portion when the cross-sectional shape of the island portion is circular, and the diameter of the circumscribed circle when the cross-sectional shape of the island portion is a deformed cross-sectional shape other than the circular shape. The same applies to the diameter of the sea-island composite fiber described later. Regarding the diameter of this island, not all islands need to have the same thickness.

The number of islands in the cross section of the sea-island composite fiber is preferably 20 or more. Therefore, it is preferable that the number of islands exposed at one end or both ends in the longitudinal direction of the sea-island composite fiber forming one brush bristle material is also 20 or more. By setting the number of the islands to 20 or more, it becomes easier to entangle dirt with the exposed islands, the cleanability is further improved, and even when the performance of holding cosmetics and the foaming performance are required. , It becomes easier to demonstrate those performances.

Further, in the hair material for a brush according to the present invention, the diameter of the sea-island composite fiber is preferably in the range of 50 to 1,000 μm, more preferably in the range of 80 to 500 μm. If the diameter of the Kaijima composite fiber is less than 50 μm, the waist of the Kaijima composite fiber portion itself when used for a brush becomes too weak, and the cleaning effect may be reduced depending on the application. If the diameter of the Kaijima composite fiber exceeds 1,000 μm, the Kaijima composite fiber part itself becomes too stiff when used for a brush, and depending on the shape (length and diameter) of the exposed island part at the tip, The sea-island composite fiber portion at the base of the exposed island portion may be strongly pressed against the object to be cleaned, which may easily damage the object to be cleaned.

Further, in the hair material for brushes according to the present invention, the resin type constituting the sea-island composite fiber is not particularly limited as long as it is composed of two or more kinds of resins having different chemical dissolution rates, and for example, the sea portion of the sea-island composite fiber. Can be exemplified by a form in which is made of a polyester resin and the island part is made of a resin having a slower drug dissolution rate than the polyester resin. More specifically, a form in which the sea part is made of polybutylene terephthalate and an island part is made of nylon (registered trademark), and a form in which the sea part is made of polyethylene terephthalate and the island part is made of polybutylene terephthalate can be exemplified.

Further, in the bristle material for brushes according to the present invention, the cross-sectional shape of the sea-island composite fiber can be set to a substantially arbitrary shape, and the cross-sectional shape is formed in a circular shape. , Any form formed in a deformed cross-sectional shape other than a circle (for example, a polygon such as a triangle or a quadrangle, a multi-leaf shape, etc.) can be adopted. This cross-sectional shape can be set according to the application and purpose of use. In addition, it is possible to use a mixture of a plurality of types of cross-sectional shapes.

Similarly, the cross-sectional shape of the island portion of the sea-island composite fiber can be set to a substantially arbitrary shape, and the cross-sectional shape is formed in a circular shape or other than a circular shape. Any form formed in a modified cross-sectional shape (for example, a polygon such as a triangle or a quadrangle, a Y shape, etc.) can be adopted. This cross-sectional shape can also be set according to the application and purpose of use. In addition, a form in which a plurality of types of cross-sectional shapes are mixed is also possible.

Further, in the hair material for brushes according to the present invention, the tip portion of the exposed island portion at the end portion (one end portion or both end portions) of the sea island composite fiber can be formed into a tapered tapered shape, and the sea island composite fiber can be formed. It is also possible to form a shape in which the cross-sectional shape of the inner island portion is substantially maintained up to the tip portion of the exposed island portion. In the form of forming the tip of the exposed island part in a tapered shape, for example, the sea part is made of a resin having a faster dissolution rate and the island part is made of a resin having a slower dissolution rate with respect to the dissolving agent. Can be achieved. The form in which the cross-sectional shape of the island portion is substantially maintained up to the tip of the exposed island portion is, for example, composed of a resin that dissolves only in the sea portion with a dissolving agent, and the island portion is used as the agent. On the other hand, it can be achieved by constructing a resin that does not dissolve.

Further, in the hair material for brushes according to the present invention, it is also possible that the sea-island composite fibers have island portions made of different materials. Furthermore, it is also possible to have a form having a plurality of islands having a plurality of cross-sectional sizes different from each other. By having a plurality of types of islands in this way, it is possible to have a plurality of functions at the same time.

The present invention also provides a brush in which the above-mentioned brush bristle material according to the present invention is used at least in a part. In particular, the brush according to the present invention uses a hair material that does not damage the object to be cleaned as described above, has excellent cleanability, has excellent durability, and has a soft touch. In particular, it is suitable as a toothbrush, a brush for precision cleaning, a face washing brush, a makeup brush, and the like.

In such a brush according to the present invention, a range of 1 to 50 mm is exemplified as a preferable range of the brush bristles length (length from the brush root to the bristles), although it depends on the use thereof, and more preferably. , 5 to 35 mm.

As described above, according to the present invention, it is possible to provide a bristle material for a brush that does not damage the object to be cleaned, has excellent cleanability, and has excellent durability.

Further, according to the present invention, it is possible to provide various brushes using at least a part of the above-mentioned brush bristle material, and particularly to provide a brush suitable as a toothbrush, a brush for precision cleaning, a face washing brush, a cosmetic brush and the like. can do.

The hair material for a brush according to an embodiment of the present invention is shown, FIG. 1 (A) is a schematic side view of one end of the hair material, and FIG. 1 (B) is shown in line BB of FIG. 1 (A). It is a schematic cross-sectional view along. It is a schematic block diagram which shows the flocking method at the time of using a brush hair material for a toothbrush. It is a schematic side view of one end part of the hair material for a brush which concerns on another embodiment of this invention. It is a schematic cross-sectional view which shows various form examples of the hair material for a brush which concerns on this invention. It is a schematic cross-sectional view which shows still another various form example of the hair material for a brush which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a hair material 1 for a brush according to an embodiment (Embodiment 1) of the present invention, and FIG. 1 (A) shows one end of the hair material 1. As shown in FIG. 1 (B), the brush hair material 1 is a cross section composed of a sea portion 2 and an island portion 3 composed of two or more types of resins having different chemical dissolution rates (two types of resins in the illustrated example). The sea island composite fiber 4 has a circular surface shape, and the island portion 3 at one end or both ends in the longitudinal direction of the sea island composite fiber 4 (FIG. 1 (A) shows only one end of the hair material 1). ) Is configured as an exposed brush hair material (hereinafter, the exposed island portion 3 is referred to as an exposed island portion 3a). In the brush hair material 1, as shown in FIG. 1 (B), the outer peripheral surface forming portion 5 forming the outer peripheral surface of the sea island composite fiber 4 is composed of only the sea portion 2, and the sea island composite fiber 4 is composed of only the sea portion 2. In the cross section of the sea-island composite fiber 4, the island portion 3 is unevenly distributed in a portion near the central portion other than the outer peripheral surface forming portion 5 over the entire region of the portion near the central portion. In particular, in the present embodiment, the ratio Ts / Di of the diameter Di of the island portion 3 closest to the outer peripheral surface forming portion 5 and the thickness Ts of the sea portion 2 of the outer peripheral surface forming portion 5 in the cross section of the sea island composite fiber 4 is 1.2. As described above, the sea-island composite fiber 4 is produced. The sea-island composite fiber 4 having such a form is a technique described in Patent Documents 2 to 4 described above, which can substantially freely design the size and arrangement of the island portion, the cross-sectional shape, the arrangement density, and the like with respect to the sea portion. Can be intentionally produced using. Alternatively, the sea-island composite fiber 4 is produced by using a conventionally known so-called pipe-type sea-island composite base (a base in which the island component is finely divided by a group of pipes and distributed in a predetermined state in the sea component). Is also possible. However, it is possible to more easily and more accurately produce the target sea-island composite fiber 4 by using the techniques described in Patent Documents 2 to 4 described above.

The exposed island portion 3a at the longitudinal end of the sea-island composite fiber 4 is formed, for example, as follows. The sea-island composite fiber 4 is composed of two types of resins having different chemical dissolution rates (for example, dissolution rate by alkaline treatment), a resin for forming the sea part 2 and a resin for forming the island part 3. Therefore, for example, the sea part 2 is made alkaline. It is formed of polybutylene terephthalate (PBT) as a polyester-based resin that is dissolved in, and the island portion 3 is formed of nylon (Ny) (registered trademark) as a resin that is not soluble in alkali, and the length of the sea-island composite fiber 4 is formed. By treating the directional end portion with alkali for a predetermined length and dissolving only the sea portion 2 of the end portion, the end portion of the brush bristle material 1 having the exposed island portion 3a as shown in FIG. 1A is formed. It is formed. The above-mentioned predetermined length of the treatment in which the alkaline treatment is performed to dissolve only the sea portion 2 and the insoluble island portion 3 is left is the exposure length of the exposed island portion 3a. This exposure length is preferably in the range of 0.5 to 10 mm as described above.

Further, in the present embodiment, since the exposed island portion 3a is composed of, for example, a resin that is not dissolved by the alkali treatment, the shape of the island portion 3 in the sea island composite fiber 4 even after being exposed by the dissolution of the sea portion 2. Is left as it is, and the exposed island portion 3a is formed in the same cross-sectional shape from the root portion to the tip portion thereof. Further, in the present embodiment, both the cross-sectional shape of the sea-island composite fiber 4 and the cross-sectional shape of the island portion 3 are formed in a circular shape, but as described above, it is also possible to make a deformed cross-sectional shape other than the circular shape. be. Further, the diameter of the island portion 3 in the sea-island composite fiber 4, particularly the preferable range of the diameter Di of the island portion 3 closest to the outer peripheral surface forming portion 5, the preferable range of the number of island portions 3 in the cross section of the sea-island composite fiber 4, and the sea-island composite. The preferable range of the diameter of the fiber 4 is as described above.

The brush bristle material 1 configured as described above is used at least in part for producing various brushes. Generally, two types of methods are generally known as methods for planting hair for a brush on a brush component, and these two methods are taken as an example in the case of use for a toothbrush. This will be described with reference to 2.

FIG. 2A shows a toothbrush 13 in which the brush bristle material 11 is flocked on the head portion of the toothbrush component 12, and as a method of flocking the brush bristle material 11, a- There are two types of methods as shown in FIGS. 2 (B) and 2 (C), which are enlarged cross-sectional views along the line a. In the method shown in FIG. 2B, the brush bristle material 11 folded in half is inserted into the bristle hole 14, and the brush bristle material 11 is fixed to the toothbrush component 12 with a fixture called a flat wire 15. .. The finished toothbrush is commonly referred to as a flat line toothbrush. In such a flat-line toothbrush, both ends of the brush bristles 11 prepared in advance serve as the bristles of the brush. In the method shown in FIG. 2C, one end of the brush bristle material 11 is inserted into the through hole 16 of the head portion surface side member 12a of the toothbrush component member 12, and the end portion of the inserted brush bristle material 11 is inserted. A heating device (not shown) is applied to form a lump for preventing or fixing, which is called a hot-bulb 17, and then the back member 12b of the head is joined to hide the hot-bulb 17 and complete the toothbrush product. Let me. The finished toothbrush is commonly referred to as a flat line toothbrush. In such a non-flat line toothbrush, one end of a brush bristles 11 prepared in advance serves as a bristles of the brush. Therefore, when the brush bristle material 1 according to the present invention is used for a flat line toothbrush, the above-mentioned exposed island portions 3a are formed at both ends of the brush bristle material 1, and the non-flat line toothbrush. When used in, the exposed island portion 3a will be formed at one end of the brush bristle material 1.

In the brush using the brush bristle material 1 according to the above embodiment, as described above, due to the structure in which the thin exposed island portions 3a are present at the ends of the bristle material, a large number of exposed island portions 3a having a relatively weak waist are used. The bristles that come into contact with the object to be cleaned are formed so that the object to be cleaned is less likely to be damaged, a soft touch is obtained, and excellent cleanability (excellent) even for small parts that are difficult to clean, such as between teeth. Dirt scraping performance, dirt entanglement performance) are exhibited. The island portion 3 of the sea island composite fiber 4 is unevenly distributed in a portion closer to the central portion other than the outer peripheral surface forming portion 5 in the cross section of the sea island composite fiber 4, so that the outer circumference of the sea island composite fiber 4 is particularly distributed. By setting the ratio Ts / Di of the thickness Ts of the outer peripheral surface forming portion 5 composed of only the sea portion 2 forming the surface to the diameter Di of the island portion 3 closest to the outer peripheral surface forming portion to 1.2 or more. The island portion 3 closest to the outer peripheral surface forming portion, and by extension, the exposed island portion 3a is supported at the root portion thereof in a state of being covered with the sea portion 2 having a sufficient thickness, and the external force is repeatedly applied to the exposed island portion 3a. Even when it is applied, it is prevented that the sea portion 2 supporting the exposed island portion 3a is torn due to the external force, and high durability of the brush bristle material 1 is realized.

FIG. 3 shows one end of the brush bristles 21 according to another embodiment of the present invention (Embodiment 2). In the present embodiment, the tip of the exposed island portion 23 exposed from the sea island composite fiber 22 at the end portion of the brush bristle material 21 is formed in a tapered shape. The brush bristle material 21 having such a form has, for example, a resin having a faster dissolution rate in the sea part (for example, polyethylene terephthalate (PET)) and a resin having a slower dissolution rate in the island part with respect to alkali as a dissolving agent. This can be achieved by configuring with (eg, polybutylene terephthalate (PBT)). In this way, the sea area around the exposed island portion 23 is removed by the alkaline treatment at the portion where the exposed island portion 23 is formed by a fast dissolution rate, and the exposed island portion 23 is left, but gradually by the alkaline treatment due to the slow dissolution rate. It is dissolved in and formed into a tapered tapered shape. Further, under the influence of the alkali treatment at the end of the sea-island composite fiber 22, the shoulder portion of the sea-island composite fiber 22 which is connected to the exposed island portion 23 and remains is rounded as shown in the figure. It has a smooth shape.

Even in the brush bristle material 21 having the exposed island portion 23 whose tip portion is formed in a tapered shape, the object to be cleaned is not easily damaged and a soft touch feeling can be obtained as in the above-described first embodiment. Moreover, excellent cleanability is exhibited even for small parts, and excellent durability can be obtained. Of these, with regard to cleanability, since the tip of the exposed island portion 23 is sharp, it is possible to exert an excellent cleaning effect even on a finer portion.

Table 1 summarizes the typical features of the first embodiment and the second embodiment when applied to a toothbrush. In the first embodiment, the sea part is formed of polybutylene terephthalate (PBT) and the island part is made of nylon (Ny) (registered trademark). It was formed with PBT), and exposed islands were formed by alkaline treatment. The characteristics of the brush bristle material in Table 1 are shown as contrasting characteristics with the brush bristle material formed of a monofilament of nylon (registered trademark), which is usually a single material, and the durability of the brush bristle material. Is shown as a contrasting characteristic with the hair material described in Patent Document 1 described above. In Table 1, ◯ indicates that the characteristics are equal to or higher than those of the comparison target, and ⊚ indicates that they are significantly superior to the comparison target.

In the hair material for brushes according to the present invention, as long as the islands are unevenly distributed in the portion near the center other than the outer peripheral surface forming portion in the cross section of the sea-island composite fiber, the islands closest to the outer peripheral surface forming portion are preferable. As long as the ratio Ts / Di of the diameter Di of the portion to the thickness Ts of the sea portion of the outer peripheral surface forming portion is 1.2 or more, the sea-island composite fiber can take various cross-sectional forms. Various forms are illustrated in FIGS. 4 and 5.

The brush bristle material 31 shown in FIG. 4 (A) has substantially the same form as that shown in FIG. 1 (B), and is composed of a sea island composite fiber 34 composed of a sea portion 32 and an island portion 33, and only the sea portion. It has an outer peripheral surface forming portion 35 having a predetermined thickness or more. The brush bristle material 41 shown in FIG. 4B has a sea island composite fiber 44 composed of a sea portion 42 and an island portion 43, and an outer peripheral surface forming portion 45 having a predetermined thickness or more composed of only the sea portion. The cross-sectional shape of 44 is formed to be substantially square. The brush bristle material 51 shown in FIG. 4C has a sea-island composite fiber 54 composed of a sea portion 52 and an island portion 53, and an outer peripheral surface forming portion 55 having a predetermined thickness or more composed of only the sea portion, and the sea-island composite fiber. Both the cross-sectional shape of 44 and the cross-sectional shape of the region where the island portion 53 exists are formed in a substantially square shape. The brush bristle material 61 shown in FIG. 4D has a sea-island composite fiber 64 composed of a sea portion 62 and an island portion 63, and an outer peripheral surface forming portion 65 having a predetermined thickness or more composed of only the sea portion, and the sea-island composite fiber. The cross-sectional shape of 64 is formed into a petal shape or a star shape. The brush bristle material 71 shown in FIG. 4 (E) has a sea-island composite fiber 74 composed of a sea portion 72 and an island portion 73, and an outer peripheral surface forming portion 75 having a predetermined thickness or more composed of only the sea portion, and the island portion 73. Are arranged in a ring shape, and there is a region 76 in which the island portion 73 is not arranged in the central portion of the cross section of the sea-island composite fiber 74.

Further, the brush hair material 81 shown in FIG. 5A has a sea-island composite fiber 84 composed of a sea portion 82, island portions 83a and 83b, and an outer peripheral surface forming portion 85 having a predetermined thickness or more composed of only the sea portion. , The islands are composed of two types of islands, an island 83a (circular cross section) and an island 83b (triangle cross section), which have different cross-sectional shapes. The island portion 83b having a triangular cross section can be expected to have a better effect of scraping dirt than the island portion 83a having a circular cross section. A well-balanced and good cleanability can be expected. The brush bristle material 91 shown in FIG. 5B has a sea-island composite fiber 94 composed of a sea portion 92 and an island portion 93, and an outer peripheral surface forming portion 95 having a predetermined thickness or more composed of only the sea portion, and the entire island portion 93. The cross-sectional shape of is formed into a triangle. Since all of the exposed islands are composed of islands with a triangular cross section, an excellent dirt scraping effect can be expected. The brush bristle material 101 shown in FIG. 5C has a sea-island composite fiber 104 composed of a sea portion 102 and an island portion 103, and an outer peripheral surface forming portion 105 having a predetermined thickness or more composed of only the sea portion, and the entire island portion 103. The cross-sectional shape of is formed in a star shape. Since all of the exposed islands are composed of star-shaped islands in cross section, excellent dirt scraping effect can be expected, and the exposed islands have excellent dirt scraping performance and moderate elasticity. It becomes possible to have both.

Further, the brush bristle material 111 shown in FIG. 5D has a sea-island composite fiber 114 composed of a sea portion 112 and an island portion 113, and an outer peripheral surface forming portion 115 having a predetermined thickness or more composed of only the sea portion, and the entire island. The cross-sectional shape of the portion 113 is formed in a Y shape. An exposed island portion having such a Y-shaped cross-sectional shape can be expected to have an excellent effect of scraping off dirt, and can also be expected to have an effect of satisfactorily retaining the scraped component in a large number of exposed island portions. Expected to have suitable performance for brushes and makeup brushes. The brush bristle material 121 shown in FIG. 5 (E) has a sea-island composite fiber 124 composed of a sea portion 122 and an island portion 123, and an outer peripheral surface forming portion 125 having a predetermined thickness or more composed of only the sea portion, and the entire island portion 123. The cross-sectional shape of is cocoon-shaped. In such an exposed island portion having a cocoon-shaped cross section, a softer tactile sensation can be expected, and the effect of retaining the scraped components well in a large number of exposed island portions can be expected. Expected to have suitable performance for brushes. Further, the brush hair material 131 shown in FIG. 5 (F) has a sea island composite fiber 134 composed of a sea portion 132 and island portions 133a and 133b, and an outer peripheral surface forming portion 135 having a predetermined thickness or more composed of only the sea portion. , The islands are formed on two types of islands 133a and 133b made of different materials. By forming the exposed islands with the islands 133a and 133b made of such different materials, for example, the exposed islands having different elasticity and tactile sensation can be mixed in a well-balanced manner, and the performance more suitable for the application can be exhibited. Becomes possible.

As described above, the sea-island composite fiber in the present invention can take various cross-sectional forms, and can be optimally designed according to the application and purpose of use.

Hereinafter, examples of the present invention will be described.
Examples 1-11, Comparative Example 1
[Making hair materials for brushes]
As raw materials, polybutylene terephthalate (PBT, manufactured by Toray Co., Ltd., "Trecon" (registered trademark) 1100SW), polyethylene terephthalate (PET, manufactured by Toray Co., Ltd., T755M), nylon 610 (Ny610, manufactured by Toray Co., Ltd.), "Amilan" (registered trademark) CM2001), thermoplastic polyamide elastomer (Ny11-PTMG (polytetramethylene glycol), Alchema "Pevax" (registered trademark) 72R53), polybutylene terephthalate (PBN, manufactured by Toyo Boseki Co., Ltd., AE) -500) was dried and prepared under the recommended conditions. Table 2 shows the resin species of the sea and islands, the area ratio between the sea and the islands, and the number of islands. Was melt-spun. After the eluted fibers are cooled and solidified in water, the first stage is stretched 4.5 times in warm water at 60 ° C. and the second stage is stretched 4.5 times in a dry atmosphere at 120 ° C., and then a remittent fever set in a dry heat atmosphere. Was carried out to obtain a sea-island composite fiber. The composition of the obtained sea-island composite fiber is shown in Table 2.

The fibers were bundled in a straight line with a bundle diameter of 45 mm, packaged, and then cut to an arbitrary length. Next, the bundle of sea-island composite fibers was immersed in a heated caustic soda solution with the cut both end faces exposed to dissolve and remove both ends to expose the islands. The exposure length of the islands was controlled by changing the immersion time in the caustic soda solution. Table 2 shows the characteristics of the obtained bristle material for brushes.

As Comparative Example 1, PBT fibers were immersed in a caustic soda solution in the same manner as described above to prepare a bristle material for a brush in which both ends were tapered and tapered.

[Making a toothbrush]
The brush hair material obtained by the above method was set in a flat wire type hair transplanter, a predetermined number (about 15 to 40 hairs) was picked, and the hair material was folded in half and driven into the hair transplant hole of the toothbrush head together with the flat line. .. As the toothbrush head, a toothbrush head having a flocked hole with a diameter of 1.5 mm and having a flocked portion of 8 rows and 4 columns was used. Table 2 shows the hair length (mm) and the number of flocked hairs (lines / holes) of the toothbrushes produced in Examples and Comparative Examples.

The following evaluations were performed on each of the obtained toothbrushes, and the results shown in Table 2 were obtained.
[Cleanability evaluation]
An artificial plaque manufactured by Nissin Co., Ltd. was applied to the dentition model and dried for 5 minutes or more. A toothbrush moistened with water was pressed from the upper surface of the dentition model with a force of 230 g, and brushing was performed in the direction along the dentition with a stroke width of 70 mm and a stroke speed of 180 mm / sec. The upper side of the back tooth part of the dentition model was used for the evaluation of the tooth surface, and the outer side of the anterior tooth part was used for the evaluation between the teeth. The cleanability was calculated from the number of brushings up to the standard based on the degree of dirt remaining after brushing 20 times with a nylon bristle toothbrush by the following formula.
Cleanability = 20 ÷ (number of brushings to reach the standard)

[Hair opening durability evaluation]
A load of 230 g is applied vertically to the toothbrush from the back side of the sliding surface, and in a state where hot water at 37 ° C is dropped, the stainless corrugated plate is slid 1000 times in the longitudinal direction of the toothbrush to make the brush part. The hair opening rate (%) was measured. The method for calculating the hair opening rate was (BA) / A × 100% when the width of the brush portion in the initial state was A mm and the width after sliding was B mm.

[Hair tear durability evaluation]
Under the same conditions as the above-mentioned evaluation of hair opening durability, the tearing of the hair tips was observed every 50 times of brushing, and the number of times the number of hair materials having hair tears became five was recorded.

[Tactile / foaming evaluation]
Twenty adults were asked to use the toothbrush for 30 days, and responses were requested according to the following criteria, and the average score was used as the evaluation value.
Score Tactile foaming 5 Very soft Very good foaming 4 Soft foaming is good 3 Usually neither can be said 2 Hard foaming is bad 1 Very hard Very bad foaming

The present invention can be applied to any brush, and is particularly suitable for toothbrushes, precision cleaning brushes, face washing brushes, makeup brushes, and the like.

1, 21 Brush hair material 2 Sea part 3 Island part 3a, 23 Exposed island part 4, 22 Sea island composite fiber 5 Outer surface forming part 11 Brush hair material 12 Toothbrush component 12a Head part front side member 12b Head part back side member 13 Toothbrush 14 Flocked hole 15 Flat line 16 Through hole 17 Burnt ball 31, 41, 51, 61, 71, 81, 91, 101, 111, 121.131 Brush hair material 32, 42, 52, 62, 72, 82 , 92, 102, 112, 122.132 Umi 33, 43, 53, 63, 73, 83a, 83b, 93, 103, 113, 123.133a. 133b Island 34, 44, 54, 64, 74, 84, 94, 104, 114, 124.134 Kaishima Composite Fiber 35, 45, 55, 65, 75, 85, 95, 105, 115, 125.135 Peripheral surface Form 76 Area where islands are not placed

Claims (15)

When a brush bristles made of sea-island composite fibers made of two or more kinds of resins having different chemical dissolution rates are used for a brush, the islands at one end or both ends of the sea-island composite fibers constituting the bristles are formed. A brush having an exposed exposed island portion and a sea portion of the sea-island composite fiber that covers the island portion on the root side of the exposed island portion and supports the exposed island portion when the bristle material for brush is used for the brush. When the bristle material for brush is used for a brush, the outer peripheral surface forming portion forming the outer peripheral surface of the sea-island composite fiber is composed of only the sea portion, and the island portion of the sea-island composite fiber is formed. , In the cross section of the sea island composite fiber, it is unevenly distributed in a portion near the central portion other than the outer peripheral surface forming portion, and in the cross section of the sea island composite fiber, the diameter Di of the island portion closest to the outer peripheral surface forming portion. A hair material for a brush, wherein the ratio Ts / Di with the thickness Ts of the sea portion of the outer peripheral surface forming portion is 1.2 or more. The brush bristle material according to claim 1 , wherein the exposed length of the island portion is in the range of 0.5 to 10 mm. The hair material for a brush according to claim 1 or 2 , wherein the diameter of the island portion is in the range of 1 to 20 μm. The hair material for a brush according to any one of claims 1 to 3 , wherein the number of the islands in the cross section of the sea-island composite fiber is 20 or more. The hair material for a brush according to any one of claims 1 to 4 , wherein the diameter of the sea-island composite fiber is in the range of 50 to 1,000 μm. The hair material for a brush according to any one of claims 1 to 5 , wherein the sea portion of the sea-island composite fiber is made of a polyester resin, and the island portion is made of a resin having a slower chemical dissolution rate than the polyester resin. The hair material for a brush according to any one of claims 1 to 6 , wherein the sea-island composite fiber has a circular cross-sectional shape. The hair material for a brush according to any one of claims 1 to 6 , wherein the cross section of the sea-island composite fiber is formed in a deformed cross-sectional shape other than a circle. The hair material for a brush according to any one of claims 1 to 8 , wherein the cross-sectional shape of the island portion of the sea-island composite fiber is formed in a circular shape. The hair material for a brush according to any one of claims 1 to 8 , wherein the cross section of the island portion of the sea-island composite fiber is formed in a deformed cross-sectional shape other than a circle. The hair material for a brush according to any one of claims 1 to 10 , wherein the tip of the exposed island at the end of the sea-island composite fiber is formed in a tapered shape. The hair material for a brush according to any one of claims 1 to 11 , wherein the sea-island composite fibers have island portions made of different materials. A brush in which at least a part of the brush bristle material according to any one of claims 1 to 12 is used. The brush according to claim 13 , wherein the hair length is in the range of 1 to 50 mm. The brush according to claim 13 or 14 , which is a toothbrush.

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