JP7352246B2 - Bristle materials for makeup brushes, makeup brushes using the bristle materials - Google Patents

Description

The present invention relates to a bristle material for a makeup brush, a bristle material assembly for a makeup brush, and a makeup brush.

Conventionally, natural animal hair such as squirrel hair, horse hair, goat hair, etc. has been used as the bristle material for makeup brushes. Natural animal hair is said to have good absorbency and release properties for liquid or powder cosmetics, has a soft texture, and is said to feel good on the skin, and is loved by many users. In particular, squirrel hair makeup brushes and goat hair makeup brushes are highly regarded by consumers as the highest quality animal hair makeup brushes. However, although natural animal hair has many advantages, since it is a natural resource, there is a limit to its supply, and it is becoming increasingly difficult to obtain it from the viewpoints of animal welfare and global ecology. Therefore, in recent years, bristle materials for cosmetic brushes made from synthetic fibers have been proposed as a substitute for natural animal hair.

For example, Patent Document 1 proposes a bristle material for brushes such as makeup brushes that contains polypropylene terephthalate as a main component and exhibits a specific bending recovery rate. Brush bristles made only of polypropylene terephthalate, even if they have tapered tips, are more durable than brush bristles made only of polybutylene terephthalate. It is specifically disclosed that it is a material that has a softer and more flexible feel than wood (see Patent Document 1).
Patent Document 2 proposes a bristle material for a makeup brush that is made of a core-sheath composite monofilament and has a tapered portion formed at one end thereof. The cross-sectional shape of the tapered part is circular, and the cross-sectional shape of the main body other than the tapered part is eight-lobed, providing excellent application performance for liquid cosmetics and a feeling of use comparable to that of natural animal hair. specifically discloses that it is a bristle material suitable for use in makeup brushes (see Patent Document 2).

Japanese Patent Application Publication No. 2003-245133 JP2009-201794A

Natural animal hair is delicately crimped, so if the hair is tied up, the tip of the application area will be spread out, so especially powdered cosmetics such as blusher and eye shadow should be applied in a blurred state. It is suitable for this purpose. On the other hand, with synthetic fiber brush bristles, the synthetic fibers themselves are linear, so when the bristles are bundled, the tip of the applied part does not spread out and remains straight. Although it is suitable for applying paste-like or liquid cosmetics, it is known that it is not suitable for applying powder-like cosmetics.
Therefore, the present invention provides a bristle material for a cosmetic brush made of synthetic resin, which is suitable for applying powdered cosmetics and liquid cosmetics, and more specifically, has good catch and release properties for powdered or liquid cosmetics. An object of the present invention is to provide a bristle assembly for a makeup brush and a makeup brush using the same.

As a result of extensive research in order to solve the above problems, the inventors of the present invention have found that S-twisted or Z-twisted synthetic resin brush bristle material having a specific cross-sectional shape has catch-and-release properties for powdered or liquid cosmetics. We have found that the above-mentioned problem is solved by discovering that it is extremely superior.

Specifically, the present invention has the following points.
1. Consists of S-twisted or Z-twisted synthetic resin monofilament,
A bristle material for a makeup brush, characterized in that a cross section of the monofilament in a direction perpendicular to the fiber axis has an eyebrow shape.
2. 1. The monofilament is characterized in that it has a tapered portion. Bristle material for makeup brushes as described.
3. 2. The tapered part is branched. Bristle material for makeup brushes as described.
4. 1. The synthetic resin is a polyester resin. ~3. The bristle material for a makeup brush according to any one of the above.
5. 4. The polyester resin is one or more selected from polytrimethylene terephthalate, polyethylene terephthalate, and polybutylene terephthalate. Bristle material for makeup brushes as described.
6. Consists of a mixed aggregate of S-twisted and Z-twisted synthetic resin monofilaments,
A bristle assembly for a makeup brush, characterized in that a cross section of the monofilament in a direction perpendicular to the fiber axis has an eyebrow shape.
7.1. ~5. The bristle material for makeup brushes according to any one of Item 1 or 6. A makeup brush, characterized in that the bristle material aggregate for makeup brushes described in 1 is used in at least a portion thereof.

The bristle material for cosmetic brushes of the present invention has two specific three-dimensional shapes, namely twisted and a specific cross-sectional shape, and the combination of these three-dimensional shapes produces a synergistic effect, making it an attractive material for powdered or liquid cosmetics. &Releases better performance than natural animal hair. Furthermore, by providing the tapered end, the bristle material for a makeup brush can have both skin feel and flexibility comparable to natural animal hair.

FIG. 1 is a schematic cross-sectional view of an eyebrow-shaped bristle material for a cosmetic brush according to the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the eyebrow-shaped shape of the present invention. (A) to (C) are schematic diagrams of cross-sectional shapes that are not included in the present invention. It is an optical micrograph (150 times) of the bristle material for makeup brushes of this invention. It is an optical micrograph (100 times) of the bristle material for makeup brushes of this invention in which the taper part is branched. It is a graph showing the evaluation test results of "Evaluation 1 of Usage Performance of Cosmetic Brush: Evaluation of Powder Catching Performance" in Example. It is a graph showing the evaluation test results of "Evaluation of usability of makeup brushes 2: Evaluation of powder release properties" in Examples.

The present invention relates to a bristle material for a makeup brush, a bristle material assembly for a makeup brush, and a makeup brush, which are made of S-twisted or Z-twisted synthetic resin monofilaments, and the monofilament has an eyebrow-shaped cross section in a direction perpendicular to the fiber axis. Regarding.
The present invention will be explained in detail below.

The bristle material for a cosmetic brush of the present invention is made of synthetic resin monofilament having an S-twist or Z-twist structure. In other words, it has a helical structure of either "S-twist material (right-handed twist)" or "Z-twist material (left-handed twist)," and unlike straight fibers or wave-shaped fibers, the fibers are perpendicular to the helical axis. It has a three-dimensional spread in the direction of
The volume occupied by one bristle material having a spiral structure due to such twisting is larger than that of a bristle material having a flat zigzag structure formed by a conventionally known gear crimp method, and the volume occupied by one bristle material having a spiral structure due to such twisting is larger than that of a bristle material having a flat zigzag structure formed by a conventionally known gear crimp method. Bristle aggregates for makeup brushes made of bristle materials and makeup brushes are fluffy and have a high volume, with the bristle materials suppressing overlapping and adhesion to each other even in a stationary state, and containing many voids inside. Furthermore, it is preferable to combine S twist and Z twist because the number of internal voids increases and the three-dimensional effect can be enhanced.

The number of twists of the bristle material for makeup brushes of the present invention is such that when it is made into a bristle material aggregate for a makeup brush or a makeup brush, a void is formed between adjacent bristle materials for holding powdered or liquid cosmetics. Therefore, it is preferable to set it within the range of 30 T/m (turns/m) or more and 100 T/m (turns/m) or less for both S twist and Z twist, and 40 T/m (turns/m). ) or more and 90 T/m (turns/m) or less is more preferable. If the number of twists is within the above range, it is possible to provide a helical structure with a wavelength width of more than 10 mm and less than 35 mm in the length direction of the fiber.
Normally, in order to give monofilament a three-dimensional effect, strong twisting is required to shorten the wavelength width, but in the cosmetic brush bristle material of the present invention, the number of twists is small (soft twisting). The width is increased. By reducing the number of twists in this way, it is possible to obtain a brush bristle material with a more three-dimensional appearance, and after twisting several monofilaments together, the fibers can be easily opened by combing. This also has the effect of improving manufacturing efficiency. In addition, with heavy twisting, the hair becomes stiff and feels uncomfortable against the skin.
On the other hand, when the wavelength width exceeds 35 mm, the twist becomes loose and the hair material becomes nearly linear, so the three-dimensional spread of the hair material decreases, and the voids between the hair materials are reduced, so powdery or liquid makeup is used. The amount of collected and retained materials tends to decrease. Furthermore, if the wavelength width is less than 10 mm, the hair materials tend to become entangled with each other, resulting in a decrease in manufacturing efficiency. The wavelength width of the bristle material for cosmetic brushes of the present invention is preferably in the range of 11 mm or more and 25 mm or less, more preferably 12 mm or more and 20 mm or less.

The bristle material for a cosmetic brush of the present invention is made of S-twisted or Z-twisted synthetic resin monofilament whose cross section in the direction perpendicular to the fiber axis is eyebrow-shaped.
The cross-sectional shape of the bristle material for cosmetic brushes of the present invention will be explained according to FIGS. 1 to 3. Both FIGS. 1 and 2 are schematic cross-sectional views of the bristle material for a makeup brush of the present invention. FIGS. 3A to 3C are schematic diagrams of cross-sectional shapes that are not included in the present invention.
The cocoon-shaped shape in the present invention means a straw-shaped shape that is long and has a gentle constriction in the center (body part) like a cocoon made by a silkworm, as shown in Figure 1, and as shown in Figure 3 (A). It does not include cross-sectional shapes that have no constriction in the center portion (body portion). In addition, the cocoon-shaped shape of the present invention includes a shape having a large constriction in the center portion (body portion) as shown in FIG. Does not include those with constrictions.
As shown in FIGS. 1 and 2, the eyebrow-shaped shape according to the present invention has an "angle" formed by two tangent lines (dotted lines) along the gentle constriction starting from the center of the constriction and being greater than 90 degrees and less than 180 degrees. It is characterized by In the eyebrow shape according to the present invention, the "angle" is preferably 100 degrees or more, more preferably 120 degrees or more, and even more preferably 130 degrees or more. An aspect that is not included in the present invention is that, as shown in FIG. 3(B), the "angle" between two tangent lines (dotted lines) along the waist is smaller than 90 degrees, and the vertical angle is acute. A groove is formed.
The present inventor has confirmed that the presence of longitudinal grooves in the length direction of the fibers of the bristle material for cosmetic brushes improves the ability to catch powdered or liquid cosmetics. However, if the vertical grooves have an acute angle (within 90 degrees), the powdered or liquid cosmetics contained in the makeup brush bristle material will be retained in the vertical grooves, resulting in poor release (release). The present inventors have discovered for the first time that this decreases the That is, the bristle material for a makeup brush of the present invention has a cross section that is gently streamlined, that is, an eyebrow-shaped shape having a constriction in which the above-mentioned "angle" is greater than 90 degrees and smaller than 180 degrees. The present invention was completed based on the discovery that it exhibits excellent catch and release properties, particularly release properties, for powdered or liquid cosmetics.

The cross-sectional shape of the bristle material for a makeup brush of the present invention will be explained in more detail with reference to FIG.
In FIG. 1, a represents the major axis of the bristle material for makeup brushes of the present invention (hereinafter referred to as major axis a), b represents the recess width (hereinafter referred to as recess width b), and c represents the short axis (hereinafter referred to as short axis c). ), d means the diameter of the depression (hereinafter referred to as the diameter of the depression d).
In the bristle material for cosmetic brushes of the present invention, the major axis a is in the range of 100 μm or more and 200 μm or less, particularly preferably 110 μm or more and 170 μm or less, and more preferably 120 μm or more and 160 μm or less. The recess width b is in the range of 50% or more and 75% or less of the major axis a, the short axis c is in the range of 10 μm or more and 100 μm or less, and the recess diameter d is 40% or more and 90% or less of the short axis c. The aspect ratio (a/d) between the major axis a and the depression diameter d is in the range of 1.1 or more and 8.0 or less, and preferably in the range of 2.0 or more and 7.8 or less. Further, the aspect ratio (c/d) between the minor axis c and the depression diameter d is in the range of 1.1 or more and 3.0 or less, preferably in the range of 1.1 or more and 2.5 or less.
When the major axis a, the recess width b, the short axis c, and the recess diameter d are within the above ranges, excellent performance is exhibited in terms of catch and release properties for powdered or liquid cosmetics.

The bristle material for cosmetic brushes of the present invention exhibits a synergistic effect due to the combination of two specific three-dimensional shapes, which have an S-twist or Z-twist twist structure and a cocoon-shaped cross section. It exhibits extremely excellent initial release properties in terms of catch and release properties for powdered or liquid cosmetics, particularly in terms of release properties (release properties) for powdered or liquid cosmetics. As will be explained in detail in the examples below, the bristle material for makeup brushes of the present invention has a powder-like bristle material compared to goat hair makeup brushes, which have received high praise from consumers as the highest quality animal hair makeup brushes. It has excellent performance, with a 1.3 to 1.8 times higher ability to catch cosmetics. In addition, regarding the release properties (release properties) for powdered or liquid cosmetics, the initial release properties (release properties) are about 1.2 times higher than that of goat hair makeup brushes, and the brush has excellent performance. The present inventor has confirmed for the first time that the bristle material for cosmetic brushes of the present invention exhibits a catch-and-release effect on powdered or liquid cosmetics, that is, is excellent in both retention and release performance. This is a particularly remarkable effect.

The bristle material for a cosmetic brush of the present invention is made of synthetic resin monofilament. As this synthetic resin, one type or two or more types of synthetic resins such as polyamide resin, polyolefin resin, polyacrylonitrile resin, and polyester resin can be selected or used in combination, but among these, Polyester resin is suitable as a bristle material for makeup brushes because it has appropriate rigidity and durability and is excellent in extrusion processing, twisting processing, tapering processing, etc. Among these, one or more types selected from polyester resins such as polytrimethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, and polylactic acid are preferable. Furthermore, in terms of having appropriate flexibility and elasticity, it is preferable to use one or more selected from polytrimethylene terephthalate (PTT), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). preferable. The synthetic resin monofilament of the present invention may contain conventional additives such as heat resistant agents, weather resistant agents, plasticizers, colorants, etc., as long as they do not impede the object of the present invention.

The cosmetic brush of the present invention is characterized in that the cosmetic brush bristle material of the present invention or the cosmetic brush bristle material assembly of the present invention is used at least in part. More specifically, the cosmetic brush of the present invention preferably contains the cosmetic brush bristle material of the present invention or the cosmetic brush bristle aggregate of the present invention in an amount of 10% or more by weight of the entire makeup brush bristle material, and preferably contains 20% by weight or more of the cosmetic brush bristle material of the present invention. The content is more preferably 25% by weight or more, even more preferably 30% by weight or more, and particularly preferably 30% by weight or more.
The cosmetic brush of the present invention contains the bristle material for a cosmetic brush of the present invention or the bristle material aggregate for a cosmetic brush of the present invention in an amount of 10% to 100% by weight of the entire bristle material for a cosmetic brush. Cosmetic brushes made from natural animal hair not only exhibit superior performance in catching and releasing powdered or liquid cosmetics than cosmetic brushes made from natural animal hair, but also in terms of skin feel and flexibility. It can be approximated by In particular, the cosmetic brush of the present invention, which contains the bristle material for a cosmetic brush of the present invention or the bristle material aggregate for a cosmetic brush of the present invention in an amount of 30% by weight or more based on the entire bristle material for a cosmetic brush, can fully exhibit the effects of the present invention. able to demonstrate.
In the makeup brush of the present invention, other than the makeup brush bristle material of the present invention or the makeup brush bristle aggregate of the present invention, makeup brush bristle materials made of synthetic fibers such as nylon fibers and polyester fibers may be used. can.
Further, in the cosmetic brush of the present invention, it is preferable that the tip of the synthetic resin monofilament is processed to have a tapered part. Furthermore, it is more preferable that the tapered portion is processed to branch. By processing the tip in this way, it feels better on the skin when applying cosmetics, and provides an excellent tactile sensation that is closer to natural animal hair.

<Method for manufacturing bristle material for makeup brushes>
Next, one example of the method for manufacturing the bristle material for cosmetic brushes of the present invention will be described.
Synthetic resin monofilaments used as bristle materials for makeup brushes are made by mixing and stirring synthetic resin pellets or powder such as polyester resin and additives as necessary to uniformly disperse them, and then placing them in the hopper of an extrusion-type spinning machine. The synthetic resin mixture supplied and heated and melted is extruded from a cocoon-shaped nozzle corresponding to the cross-sectional shape of the hair material of the present invention, spun from a spinneret, and stretched 4 to 5 times by three stages of heating and stretching. , a synthetic resin monofilament with a cocoon-shaped cross section is manufactured.
After twisting the synthetic resin monofilaments to the above-described number of twists, the twisted synthetic resin monofilaments are heated at a temperature below the melting point of the synthetic resin to heat set. The heat setting time depends on the temperature, but is, for example, about 5 minutes at 185°C. As a result, the twisted structure is fixed and the shape becomes stable without being affected by the usage environment. Then, the heat-set synthetic resin monofilament is cut into a predetermined length, for example, 25 mm or more, preferably 50 mm or more and 100 mm or less.

The cut synthetic resin monofilament may have a tapered tip at its tip, if necessary. To do this, the cut synthetic resin monofilament is immersed from the tip to the center in a strong alkaline solution (e.g., aqueous sodium hydroxide solution) with a catalyst added to promote hydrolysis and maintained at a constant temperature. . After being immersed for a predetermined period of time, the tip of the synthetic resin monofilament is tapered and a sharp tapered part is formed by pulling it up. The synthetic resin monofilament obtained by this method has an almost perfectly tapered end. In addition, by appropriately setting the soaking time, the eyebrow-shaped constriction of the cross section of the synthetic resin monofilament is dissolved, and the tip of the tapered part is branched into two and sharpened bristle material for a makeup brush can be obtained. I can do it. This method is suitable because it can easily form a bristle material for a makeup brush with branched taper parts. The length of this tapered part may be in the range of 1 to 30 mm, and the length of the branched part may be in the range of 0.1 to 20 mm, depending on the purpose and application.

Next, this bundle of synthetic resin monofilaments is washed with water and dried. Then, a bundle of synthetic resin monofilaments is combed and twisted together to form a single bristle material for a makeup brush.
The thus obtained cosmetic brush bristle material has an eyebrow-shaped cross section in the direction perpendicular to the fiber axis of the monofilament, and leaves traces of heat-set twisting, as shown in Figure 4. , it has a specific cross-sectional shape and helical structure. Further, by performing an alkali treatment, a bristle material for a makeup brush having a branched taper as shown in FIG. 5 can be obtained.
Furthermore, dyeing treatment may be performed as necessary. Disperse dyes can be used as dyes, but dyes with a weather fastness of grade 5 or higher are preferred because they are less prone to discoloration or fading when used with makeup brushes. Further, although the dye may be used in combination with a known dye carrier agent, it is preferable to use high-pressure dyeing that does not require a dye carrier agent. Furthermore, carbon black, various pigments, and the like may be added to the raw materials for producing monofilaments. This case is preferable because not only can the amount of dye used during dyeing be saved, but also dyeing may not be necessary depending on the application.

<Bristles aggregate for makeup brushes>
The bristle material assembly for cosmetic brushes of the present invention is a mixed assembly of S-twisted and Z-twisted bristle materials for cosmetic brushes. When a makeup brush is made from a makeup brush bristle assembly containing a mixture of S-twist and Z-twist makeup brush bristle materials, the flow of the bristle material at the tip of the application part becomes random, and powdery or liquid cosmetics are mixed. This is preferable because the amount of collection and the amount of retention are uniform. Depending on the user's usage and usage habits, makeup brushes can twist in a certain direction and cause curls in the application area, but the combination of S-twist and Z-twist makes makeup brushes less likely to get curly. The durability is further improved, which is preferable.
In the makeup brush bristle material assembly of the present invention, it is preferable that the S-twist makeup brush bristle material and the Z-twist makeup brush bristle material are mixed in a ratio of 4:6 to 6:4. By using a bristle aggregate for makeup brushes mixed at a ratio of 4:6 to 6:4 in the application area of the makeup brush, the internal voids become larger and an application area with a three-dimensional effect is formed. This applicator is more similar to the applicator using animal hair, and can evenly apply powdered or liquid cosmetics. Further, it is preferable that the S-twist bristle material for a makeup brush and the Z-twist bristle material for a makeup brush are almost uniformly mixed. This "substantially uniformly mixed" means that the S-twist makeup brush bristle material and the Z-twist makeup brush bristle material are not solidified and localized, but are dispersed. For example, a Z-twist makeup brush bristle material is placed next to an S-twist makeup brush bristle material, and conversely, an S-twist makeup brush bristle material is placed next to a Z-twist makeup brush bristle material. This refers to a state in which S-twist makeup brush bristle material and Z-twist makeup brush bristle material are arranged almost alternately over almost the entire application area of the makeup brush. Because the S-twist makeup brush bristle material and the Z-twist makeup brush bristle material are almost uniformly mixed, adjacent makeup brush bristle materials are prevented from coming into close contact with each other and crowding together. In addition, voids are easily formed between the bristle materials for the makeup brush, and a fluffy makeup brush with a high volume can be formed.
In addition, the application area of a makeup brush made of an almost uniform mixture of S-twisted makeup brush bristle material and Z-twisted makeup brush bristle material has bristle of 0.3 g/cm ³ to 0.5 g/cm ³ . Density is preferred. If the hair density of the application part of the makeup brush is within the range mentioned above, the application part will have a three-dimensional effect, and the tip of the application part will expand and give a sense of volume, resembling an applicator using natural animal hair. This makes it suitable for applying powdered or liquid cosmetics.

<Method for manufacturing makeup brushes>
An example of a method for manufacturing a makeup brush using the bristle material for makeup brushes or the bristle material aggregate for makeup brushes of the present invention obtained by the above-mentioned manufacturing method etc. will be described.
The bristle material for makeup brushes or the bristle material aggregate for makeup brushes of the present invention is applied to at least a portion of the entire bristle material for makeup brushes, preferably at least 10% by weight, more preferably at least 20% by weight, and even more preferably at least 25% by weight. % or more, preferably 30% or more by weight, is put into a jar for forming a brush tip, and while applying vibration, a brush tip with a raised center part is formed according to the internal shape of the jar, and then molded. The brushed tip portion is inserted into a cylindrical mouthpiece provided at the tip of the makeup brush handle portion to form a makeup brush.

The makeup brush of the present invention is suitable for uniformly applying powdered or liquid cosmetics, and can be used with various makeup brushes, such as liquid brushes, lip brushes, nail care brushes, foundation brushes, powder brushes, shadow brushes, and blusher brushes. , can be used as a highlight brush, concealer brush, etc. Among these, it is particularly suitable for applying powdered cosmetics while spreading it thinly on the skin surface, so-called blurring, and is suitable for use with face brushes, blusher brushes, highlight brushes, or brushes that often use this application method. Demonstrates excellent performance when used as a brush for shadows such as eye shadow.

The present invention will be explained below with reference to Examples, but the technical scope of the present invention is not limited by these.

<Manufacturing example of the bristle material for makeup brushes and makeup brushes of the present invention>
(Makeup brush A)
60 pieces of polytrimethylene terephthalate monofilament having a cocoon-shaped cross-sectional shape (equivalent to major axis a = 156 μm, concave width b = 100 μm, minor axis c = 56 μm, concave diameter d = 25 μm) were twisted using a twisting machine at 80T. /m (turns/m) of twists in the S-shaped direction (S twist) and those in the Z-shaped direction (Z twist) were treated with steam at 120°C for 40 minutes to stop twisting. As a result, S-twist and Z-twist bristle aggregates for cosmetic brushes with a wavelength width of 11 mm were obtained. Next, the S-twist and Z-twist of the bristle material aggregate for a makeup brush were mixed at a ratio of 1:1 and pulled together to form a fiber bundle with a diameter of 4 cm, which was protected by wrapping with paper. This fiber bundle was cut into a length of 8 cm to form a roll having a diameter of 4 cm and a length of 8 cm. Furthermore, an aqueous solution containing 100 g/L of sodium hydroxide and 6 g/L of quaternary amine (manufactured by Ippo Sha Yushi Kogyo Co., Ltd., trade name "DYK-1125") was prepared, and one end of the fiber bundle was immersed in the solution. After processing at 130°C for 130 minutes to dye the tapered fiber bundles, the strands were combed and placed in a concave pot with the bristles facing down and vibrated to create a makeup brush A with the hair shape adjusted. .

(Makeup brush B)
In the production example of the above-mentioned "cosmetic brush A", a polytrimethylene terephthalate monofilament having an eyebrow-shaped cross-sectional shape (corresponding to the major axis a = 126 μm, the concave width b = 76 μm, the minor axis c = 54 μm, and the concave diameter d = 46 μm). ) x 60 strands were twisted at 80 T/m (turns/m) using a twisting machine in the S-shaped direction (S twist) and in the Z-shaped direction (Z twist). Cosmetic brush B was created in the same manner.

(Comparative example brush)
In the manufacturing example of the above "cosmetic brush A", 60 pieces of polytrimethylene terephthalate monofilament having a circular cross-sectional shape of 75 μm (0.075 mm: equivalent to "fiber diameter") are twisted by a twisting machine at 80 T/m ( Comparative example brushes were created in the same manner except that the number of twists (turns/m) in the S-shaped direction (S twist) and in the Z-shaped direction (Z twist) were used.

<Evaluation of usability of makeup brushes 1: Evaluation of powder catchability>
A test was conducted to evaluate the powder catchability (retainability) of the makeup brush of the present invention. In the present invention, powder catchability (retainability) refers to the ability of powdered cosmetics to stick to a makeup brush.
(Test sample)
In addition to the cosmetic brushes A, B, and comparative example brushes manufactured according to the above production example, commercially available goat hair (Sokoho) cosmetic brushes are highly rated by consumers as the highest quality animal hair makeup brushes. Using a surface property tester (manufactured by Trinity Lab Co., Ltd., product name: Tori Labo Handy Love Tester Type), the powder catching property (inclusion property) of a powdered cosmetic (manufactured by Shiseido Co., Ltd.: Integrate Mineral Glow Presto Powder) was measured using :TL701).
(Test method)
A circular container (diameter: 5.5 cm) filled with a powdered cosmetic was attached approximately perpendicularly to the contact of the surface property tester using double-sided tape. Each test sample was attached to a rotary stand so that the tip of the makeup brush, which was a test sample, was in contact with the surface of the powdered cosmetic at a substantially right angle, and was fixed horizontally to the test stand.
Sweep the tip of the makeup brush against the surface of the powdered cosmetic 10 times (speed: 6 rpm, rotation radius: 100 mm, rotation angle: 90 degrees) to pick up the powdered cosmetic on the tip of the makeup brush. I let it happen.
The powder catching ability of each test sample was evaluated by measuring the weight of the makeup brush before and after the test, and evaluating the weight difference 10 times as the powder catching amount (containing amount).
For unused makeup brushes, use the above test method to sweep the surface of powdered cosmetics 10 times to collect the powdered cosmetics, and then sweep the makeup brush against a tissue. The powdered cosmetic was released until it no longer adhered and was used as a test sample.
The test was conducted twice, and the average value of each test specimen is shown in FIG.

From the results shown in FIG. 6, the amount of powder caught by the makeup brushes A and B made of the bristle material for makeup brushes of the present invention is approximately 2.6 to 3.4 times that of the comparative brush having a circular cross-sectional shape. It was confirmed that there are many It was also confirmed that the amount of powder caught was approximately 1.3 to 1.8 times greater than that of commercially available goat hair makeup brushes.
The bristle material for makeup brushes of the present invention exhibits a synergistic effect through the combination of two specific three-dimensional shapes, namely, twisting and a specific cross-sectional shape, and can be made into a makeup brush with excellent powder catching properties. This became clear from the evaluation results.

<Evaluation of usability of makeup brushes 2: Evaluation of powder release properties>
A test was conducted to evaluate the powder release properties of the cosmetic brush of the present invention. In the present invention, the term "powder release property" refers to the ability to spit powdered cosmetics from a makeup brush onto an application surface.
(Test sample)
The same makeup brush A as in "Evaluation 1 of performance in use of makeup brushes" and a commercially available goat hair (Sokoho) makeup brush were used. Cosmetic brushes made from goat hair, especially soft wool from the neck to the chest that is less abrasive, contain a large amount of powdered cosmetics and have good release properties, making them ideal for use with foundations and blushers. This makeup brush has received high praise from consumers as a makeup brush that can be used to apply everything from wide areas such as makeup to fine details such as eye shadow.

(Preparation for powder release evaluation test)
Each test specimen was placed on a rotating table so that the tip of each makeup brush was in contact with the surface of the powdered cosmetic (Integrate Mineral Glow Presto Powder, manufactured by Shiseido Co., Ltd.) held horizontally at a right angle. and fixed it perpendicular to the test table.
Sweep the tip of each makeup brush against the surface of the powdered cosmetic (speed: 6 rpm, rotation radius: 100 mm, rotation angle: 90 degrees), and roughly apply the powdered cosmetic to the tip of each makeup brush. 0.01g was picked up.
The makeup brush A of the present invention was able to collect 0.01g of powdered cosmetics after 5 sweeps, whereas the goat hair (Sokoho) makeup brush could collect 0.01g of powdered cosmetics only after 15 sweeps. It was not possible to collect 0.01g of.
This result also shows that the makeup brush A made of the bristle material for makeup brushes of the present invention has extremely superior ability to catch (retain) powdered cosmetics compared to the makeup brush made of goat hair (Sokoho). confirmed.
(Powder release evaluation test)
A makeup sponge was attached to a cylindrical base (diameter: 47 mm) as an application surface. Each test specimen was attached to a jig and fixed so that the tip of the makeup brush, which had picked up the powdered cosmetic as the test specimen, touched the surface of the makeup sponge at a substantially right angle.
The tip of the makeup brush was moved against the application surface 5, 10, 15, and 20 times (speed: 6 rpm, rotation radius: 100 mm) to apply the powdered cosmetic to the application surface.
The powder release properties of each test sample were determined by measuring the weight of the makeup brush after moving it 5, 10, 15, and 20 times, and taking the difference in weight from the makeup brush before the evaluation test as the powder release amount each time. The amount divided by the collection cosmetic before the evaluation test was evaluated as the powder release rate (%).
The test was conducted three times, and the average powder release rate (%) of each test specimen is shown in FIG.

From the results in FIG. 7, it can be seen that the makeup brush A made of the bristle material for makeup brushes of the present invention is a makeup brush made of goat hair (Sokoho), which is known to have good catch and release properties for powdered cosmetics. It was revealed that the release properties (release properties), especially the initial release properties (release properties) after applying 5 times from the start of the test, were 1.2 times or more superior. This excellent initial release property means that cosmetics can be applied to the skin just by stroking the skin several times with a makeup brush, and when using point makeup cosmetics such as blusher or eye shadow, This shows that excellent functionality can be easily obtained, and this is an extremely advantageous effect for a makeup brush.
The bristle material for makeup brushes of the present invention has a synergistic effect due to the combination of two unique three-dimensional shapes, namely twist and a specific cross-sectional shape, and has better powder catching properties than goat hair (Sokoho) makeup brushes. It can be used as a makeup brush that can easily contain a large amount of cosmetics, and has excellent powder release properties, especially in the initial powder release properties. The results of "Evaluation 2 of Usage Performance of Cosmetic Brush" revealed that it can be a cosmetic brush that exhibits excellent effects and quickly and reliably releases the cosmetics it contains.
The bristle material for cosmetic brushes of the present invention has excellent properties in both catching and releasing properties, so liquid or powdered cosmetics can be used without wasting them. In addition, the makeup brush can be made extremely easy to use for the user, as there is little fear of color mixing with other liquid or powder cosmetics.

The bristle material for cosmetic brushes of the present invention has two specific three-dimensional shapes: twisted, that is, S-twist or Z-twist, and a specific eyebrow-shaped cross-sectional shape, so that the combination of the three-dimensional shapes can produce a synergistic effect. It exhibits extremely superior catch and release properties for powdered or liquid cosmetics compared to natural animal hair. In particular, since it has excellent initial release properties, the cosmetics contained therein can be quickly applied to the skin, and it can be suitably used as a makeup brush.
Furthermore, by providing the tapered end, the bristle material for a makeup brush can have both skin feel and flexibility comparable to natural animal hair.

Claims (7)

Consists of S-twisted or Z-twisted synthetic resin monofilament,
A bristle material for a makeup brush, characterized in that the entire cross section of the monofilament in a direction perpendicular to the fiber axis has an eyebrow-like shape with a streamlined constriction made only of curves . The bristle material for a makeup brush according to claim 1, wherein the monofilament has a tapered end. The bristle material for a cosmetic brush according to claim 2, wherein the tapered end portion is branched. The bristle material for a makeup brush according to any one of claims 1 to 3, wherein the synthetic resin is a polyester resin. The bristle material for a cosmetic brush according to claim 4, wherein the polyester resin is one or more selected from polytrimethylene terephthalate, polyethylene terephthalate, and polybutylene terephthalate. Consisting of a mixed aggregate of S-twisted and Z-twisted synthetic resin monofilaments, all cross-sections of the monofilaments in the direction perpendicular to the fiber axis have a cocoon -shaped constriction consisting of streamlined shapes consisting only of curved lines. A bristle material assembly for makeup brushes characterized by: A makeup brush, characterized in that the bristle assembly for makeup brushes according to claim 6 is used in at least a portion thereof.