Liquid cosmetic feeder and liquid cosmetic applicator

Abstract

[Problem] To provide a liquid cosmetic feeder which can be manufactured without depending on extrusion molding. To also provide a liquid cosmetic applicator such as an eyeliner, an eyebrow, a shadow liner, or a concealer capable of smoothly guiding and discharging a coating by using the liquid cosmetic feeder. [Solution] The liquid cosmetic feeder is used for a liquid cosmetic applicator. The liquid cosmetic feeder is formed by injection molding from a synthetic resin material. An extra-fine liquid cosmetic flow groove is formed on the periphery of the liquid cosmetic feeder.

Description

Liquid cosmetic feeder and liquid cosmetic applicator

[0001] The present invention relates to a liquid cosmetic applicator 1 for eyeliner, eyebrow pencil, shadow liner, concealer, etc. In particular, the present invention relates to an injection molding method for a liquid cosmetic feeder to be attached to the liquid cosmetic applicator 1, the liquid cosmetic feeder, and the liquid cosmetic applicator 1.

[0002] Known examples of liquid cosmetic applicators 1 include eyeliners, eyebrow pencils, shadow liners, concealers, etc. For example, in the liquid cosmetic container described in Patent Document 1, the liquid paint is guided to the brush part through a relay core.

[0003] Furthermore, Patent Document 2 describes the liquid cosmetic applicator as follows: "The material of the member that constitutes the storage section can be, for example, a tubular member formed by extrusion or injection molding from a synthetic resin material such as polypropylene, polyethylene, polybutylene terephthalate, or polyethylene terephthalate, taking into consideration gas permeability and liquid-tightness of the connecting portion."

[0004] In the liquid applicator described in Patent Document 3, the liquid retaining member or relay core of the liquid applicator is formed by extrusion molding.

[0005] Japanese Utility Model Application Publication No. 59-125314, Japanese Patent Application Publication No. 2019-193698, and Japanese Patent Application Publication No. 2015-24584

[0006] In extrusion molding, material is placed in an inlet, heated in a heating cylinder, and then passed through the outlet of a mold to form a specific shape. After the material is extruded, it is cooled and hardened, so the molded product has the same cross-sectional shape no matter where it is cut.

[0007] In extrusion molding, synthetic resin pellets are heated and melted using a heater and then forced into an extrusion mold, after which the formed molten plastic is cooled and solidified. Because molten plastic is constantly coming out of the extrusion mold, the extrusion mold alone cannot ensure sufficient cooling time, so the molded product is passed through a cooling device while being supported by a sizing die to prevent deformation. After leaving the sizing die, it passes through a cooling water tank and is pulled by a take-up machine and cut to the required size.

[0008] The extrusion molding process consists of the following steps 1 to 5 in order: 1. Extrusion, 2. Mold, 3. Sizing die (water tank), 4. Take-up machine, 5. Cutting machine. In the case of the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1, steps 1 to 5 above are followed by the following steps 6 and 7: 6. Shaving process, 7. In some cases, cutting to extend the entire length.

[0009] That is, in the case of a liquid cosmetic feeder 4 made by extrusion molding, cutting processes such as front end processing and rear end processing are required. Front end processing and rear end processing refer to the cutting of the front end and rear end of the liquid cosmetic feeder 4 to form the front end shape and rear end shape of the liquid cosmetic feeder 4. In addition, in the case of extrusion molding, a full length cutting process in which the entire length is cut afterwards is sometimes necessary.

[0010] Furthermore, burrs are likely to be generated during cutting processes such as front end processing and rear end processing. If there are a lot of burrs, they can clog the liquid cosmetic material flow groove 40, resulting in poor liquid cosmetic material discharge. Therefore, in some cases, a deburring process must also be added. The additional manufacturing processes of front end processing and rear end processing are disadvantageous in terms of delivery time and cost.

[0011] In the case of liquid cosmetic feeders 4 formed by extrusion molding, the workpiece is stretched after extrusion, resulting in large variations in the dimensions of the liquid cosmetic feeders 4, particularly in their outer diameter (variations of about ±0.1 mm). As a result, when assembling the liquid cosmetic feeder 4 to the liquid cosmetic applicator 1, some feeders have a large outer diameter that makes them unable to fit into the mating part, while others have a small outer diameter that makes them easily come out of the mating part, leading to assembly defects.

[0012] (Dimensional Stabilization) In extrusion molding, the variation in the outer diameter D of the liquid cosmetic feeder 4 is extremely large, at ±0.1 mm. As a result, when assembling the liquid cosmetic applicator 1, problems occur in which some feeders have a large outer diameter that prevents them from fitting into the mating part, while others have a small outer diameter that makes them easily come out of the mating part. The objective of the present invention is to reduce the variation in the outer diameter D of the liquid cosmetic feeder 4 and stabilize the dimensions.

[0013] (Process omission) Another object of the present invention is to enable molding with a stable shape without the need for front-end or rear-end processing. Another object of the present invention is to manufacture a liquid cosmetic feeder 4 at low cost and in a short time without the need for front-end or rear-end processing. (No need for a deburring process) Furthermore, with conventional extrusion molding methods, burrs are generated during the rear-end or front-end processing processes. Because burrs impede the flow of liquid cosmetics, this deburring process is absolutely necessary. A further object of the present invention is to manufacture a liquid cosmetic feeder 4 that does not require this deburring process.

[0014] Therefore, an object of the present invention is to provide a liquid cosmetic feeder 4 that is injection molded rather than extrusion molded, and that has no variation in dimensions, particularly in outer diameter. Another object of the present invention is to form the liquid cosmetic feeder 4 by injection molding. The present invention also provides a method for manufacturing the liquid cosmetic feeder 4, and a liquid cosmetic applicator 1 for eyeliner, eyebrow pencil, shadow liner, concealer, etc. that is equipped with the liquid cosmetic feeder 4 and that can smoothly guide and dispense the liquid.

[0015] (1) A liquid cosmetic feeder according to one aspect of the present invention that achieves the above-mentioned object is a liquid cosmetic feeder used in a liquid cosmetic applicator, the liquid cosmetic feeder being injection molded from synthetic resin, and having extremely fine liquid cosmetic flow grooves formed therein.

[0016] (2) Furthermore, the liquid cosmetic feeder may further include a mold rib receiving portion.

[0017] (3) In the liquid cosmetic feeder, the liquid cosmetic flow groove may have a comb-like cross section.

[0018] (4) In the liquid cosmetic feeder, the groove width W1 of the liquid cosmetic flow groove may be 0.05 mm or more and 0.2 mm or less.

[0019] (5) In addition, a method for manufacturing a liquid cosmetic feeder according to one aspect of the present invention is a method for manufacturing a liquid cosmetic feeder in which extremely fine liquid cosmetic flow grooves for flowing the liquid cosmetic are formed on the outer periphery by an injection molding method in which a heated and melted synthetic resin material is injected into a mold and cooled to obtain a molded product.

[0020] (6) Furthermore, the above-described method for manufacturing a liquid cosmetic feeder may be a method for manufacturing a liquid cosmetic feeder that does not include a post-processing step of grinding.

[0021] (7) The above-mentioned method for manufacturing a liquid cosmetic feeder may further include a step of opening the slide core in the injection molding step.

[0022] (8) Furthermore, the present invention provides a method for manufacturing a liquid cosmetic feeder as described in (5) above, in which a liquid cosmetic flow groove that fits into the plate-like member of the mold is formed.

[0023] (9) Furthermore, in the method for manufacturing the liquid cosmetic feeder described above in (7), the liquid cosmetic feeder is provided with a mold rib receiving portion 42 and a liquid cosmetic flow groove that fits into the plate-shaped member of the slide core.

[0024] (10) The method for manufacturing a liquid cosmetic feeder may be the method for manufacturing a liquid cosmetic feeder described in (5) above, in which the cross-sectional shape of the liquid cosmetic flow groove is comb-shaped.

[0025] (11) Furthermore, the method for manufacturing the liquid cosmetic feeder may be the method for manufacturing the liquid cosmetic feeder described in (10) above, in which the groove width dimension W1 of the liquid cosmetic flow groove is 0.05 mm or more and 0.2 mm or less.

[0026] (12) The liquid cosmetic feeder may be manufactured by the manufacturing method described in any one of (5) to (11) above.

[0027] (13) Furthermore, a liquid cosmetic applicator according to one aspect of the present invention may be a liquid cosmetic applicator equipped with the liquid cosmetic feeder described in (13) above.

[0028] (14) The liquid cosmetic applicator may be an eyeliner.

[0029] The present invention provides the liquid cosmetic feeder 4 by injection molding, not by extrusion molding.

[0030] 1 is a cross-sectional view of a liquid cosmetic applicator 1 equipped with a liquid cosmetic feeder 4 according to one embodiment of the present invention. An enlarged view of portion A in FIG. 1. A diagram showing a liquid cosmetic feeder 4 according to another embodiment of the present invention (having a tapered tip). (a) Side view, (b) Plan view, (c) Front view, (d) Rear view, (e) A-A' sectional view, (f) B-B' sectional view, (g) C-C' sectional view. A diagram showing a liquid cosmetic applicator 1 equipped with the liquid cosmetic feeder 4 according to the embodiment of FIG. 3. (a) Side view, (b) Rear view, (c) A-A' sectional view, (d) Enlarged sectional view of portion B. A diagram showing a liquid cosmetic feeder 4 according to yet another embodiment of the present invention (having a step portion 44 formed at the tip) and a liquid cosmetic applicator 1 equipped with the same. (a) Front view, (b) Side view, (c) Rear view, (d) Plan view, (e) Rear view, (f) Enlarged view of B, (g) C-C cross-sectional view, (h) A-A cross-sectional view, (i) D-D cross-sectional view, (j) Enlarged view of E, (k) Partial cross-sectional view. Schematic diagrams explaining the operation of an injection molding machine 60 used to manufacture a liquid cosmetic feeder 4 according to one embodiment of the present invention. (a) Schematic diagram of the injection molding machine 60, (b) Schematic diagram of the demolding process (the axis O of the liquid cosmetic feeder 4 is oriented perpendicular to the x-axis and y-axis), (c) Schematic diagram of the demolding process according to another embodiment of the present invention (the axis O of the liquid cosmetic feeder 4 is oriented in the y-axis direction), (d) Enlarged view of part A, (e) Enlarged view of part B. Cross-sectional views of a mold 62 corresponding to the liquid cosmetic feeder 4 of FIG. (a) A cross-sectional view of a mold 62 equipped with a slide core 65, (b) A cross-sectional view of a mold 62 without a slide core. Diagrams showing modified examples of a liquid cosmetic feeder 4 according to an embodiment of the present invention. (a) and (b) Diagrams of the liquid cosmetic feeder according to the embodiment of FIG. 1, (c) and (d) Diagrams of the liquid cosmetic feeder 4 according to the embodiment of FIG. 4, (e) and (f) Diagrams of the liquid cosmetic feeder 4 according to the embodiment of FIG. 5. Cross-sectional views showing modified examples of the liquid cosmetic feeder 4 according to the present invention. Cross-sectional views of a conventional liquid cosmetic feeder 4.

[0031] Hereinafter, an eyeliner will be used as an example of a liquid cosmetic applicator 1 according to an embodiment of the present invention, and will be described with reference to the accompanying drawings.

[0032] (Overall Structure of Liquid Cosmetic Applicator 1) First, as shown in FIG. 1, the liquid cosmetic applicator 1 is rod-shaped and supplies liquid cosmetic P from the rear end to the front end, and expels the liquid cosmetic P from the front end.

[0033] The liquid cosmetic applicator 1 comprises an applicator part 2 that ejects the liquid cosmetic P, a liquid cosmetic tank 3 that forms a liquid cosmetic storage space 30a that stores the liquid cosmetic P, a liquid cosmetic feeder 4 that supplies paint from the liquid cosmetic tank 3 to the applicator part 2, a pressure fluctuation buffer member 5 that buffers pressure fluctuations in the liquid cosmetic storage space 30a, and an outer case 6 provided on the outer periphery of the pressure fluctuation buffer member 5.

[0034] (Overall Shape of Liquid Cosmetic Feeder 4) Next, the liquid cosmetic feeder 4 of this embodiment will be described. The liquid cosmetic feeder 4 is used in a liquid cosmetic applicator. The liquid cosmetic feeder supplies the liquid cosmetic P to the applicator part 2, i.e., the liquid cosmetic feeder 4 is a wick provided to "relay" the liquid cosmetic P to the applicator part 2. An example of the liquid cosmetic feeder 4 of this embodiment is shown in FIG. 3. As shown in FIG. 3, the liquid cosmetic feeder 4 has, for example, a round rod shape. The rear end portion of the liquid cosmetic feeder 4 is immersed in the liquid cosmetic P, and the liquid cosmetic P is sucked up toward the front end portion by the capillary force of the liquid cosmetic feeder 4. The front end portion of the liquid cosmetic feeder 4 is covered by the applicator part 2, and the liquid cosmetic P sucked up by capillary force can be supplied to the applicator part 2 from the inside of the rear end portion of the applicator part 2. The shape of the liquid cosmetic feeder 4 may be tapered at the front end as shown in Fig. 8(c) or may have a step at the front end as shown in Fig. 8(e).Furthermore, the front and rear ends may not be tapered or have a step 44, but may be cut off as shown in Fig. 8(a).

[0035] Hereinafter, in this specification, the direction perpendicular to the axial direction, i.e., the radial direction of the liquid cosmetic feeder 4, will be referred to as the feeder radial direction. The circumferential direction of the liquid cosmetic feeder 4 will be referred to as the feeder circumferential direction. The vertical direction will be the up-down direction (y-axis direction) in Figures 3 and 5, for example. The horizontal direction will be the left-right direction (x-axis direction) in Figures 3 and 5, for example. The z-axis direction refers to the axis perpendicular to the x-axis and y-axis in a Cartesian coordinate system, with the x-axis being the horizontal direction, the y-axis being the vertical direction, and the z-axis being the depth direction.

[0036] (Arrangement of liquid cosmetic feeder 4) In this embodiment, as shown in Figure 1, the liquid cosmetic feeder 4 is inserted into the hole 2a from the rear end side of the applicator part 2 and provided to the liquid cosmetic applicator 1. In other words, the liquid cosmetic feeder 4 is inserted into the applicator part 2 and used with the liquid cosmetic applicator 1. However, as long as the liquid cosmetic P can be circulated through the applicator part 2, the hole 2a does not necessarily have to be provided.

[0037] A conical tip space S1 is formed between the liquid cosmetic feeder 4 and the inner surface of the hole 2a further forward than the front end face of the liquid cosmetic feeder 4. The rear end of the liquid cosmetic feeder 4 is disposed within a liquid cosmetic storage space 30a of the liquid cosmetic tank 3 (described later) (see FIG. 1).

[0038] (Material of Liquid Cosmetic Feeder 4) The liquid cosmetic feeder 4 is made of a synthetic resin material, such as polyacetal (POM), polyamide (PA) (nylon), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and polycarbonate (PC).

[0039] (Method of Manufacturing Liquid Cosmetic Feeder 4) The present inventors have succeeded in manufacturing a liquid cosmetic feeder 4 using injection molding for the first time. It was previously thought that conventional injection molding methods would be unable to manufacture a rod-shaped liquid cosmetic feeder 4, as shown in FIG. 10 , in which extremely thin liquid cosmetic flow channels 40 with a groove width W1 of approximately 0.1 mm are formed in the radial and axial directions. The present inventors devised the shape and structure of a mold 62, described in detail below, and used injection molding to successfully manufacture a rod-shaped liquid cosmetic feeder 4 in which extremely thin liquid cosmetic flow channels 40 with a groove width W1 of approximately 0.1 mm are formed in the radial and axial directions. The plastic liquid cosmetic feeder 4 according to an embodiment of the present invention is a liquid cosmetic feeder 4 in which extremely thin liquid cosmetic flow channels 40 with a groove width W1 of approximately 0.1 mm are formed around the outer periphery of the liquid cosmetic feeder 4 ( FIG. 3 ).

[0040] Therefore, manufacturing a liquid cosmetic feeder 4 using injection molding was previously considered impossible and unthinkable. Conventional extrusion molding involves extruding a workpiece through a relatively large mold 62, stretching it, and creating a thin shape. This made it possible to form grooves of approximately 0.1 mm in size on the outer circumferential surface 43 of the liquid cosmetic feeder. However, significant dimensional variation occurred in the molded liquid cosmetic feeders 4. In particular, there was considerable variation in the outer diameter of the liquid cosmetic feeders 4 (variation of approximately ±0.1 mm).

[0041] In this case, in order to form the liquid cosmetic flow groove 40 with a groove width dimension W1 of 0.1 mm, the structure inside the mold 62 could be realized by laminating thin plates of 0.1 mm, 0.2 mm, etc., and therefore it was possible to successfully produce by injection molding the thin tube body that is the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1. The liquid cosmetic feeder 4 could be integrally molded by using the injection molding method described in detail below to give the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 a comb-like shape.

[0042] (Liquid Cosmetics) Liquid cosmetics that can be used with the liquid cosmetic applicator 1 of the present invention are a type of cosmetic product in liquid form. Examples include liquid cosmetics used in eyeliners, etc. Liquid cosmetics include facial cleansers, lotions, emulsions, and serums. The liquid cosmetic applicator 1 of the present invention can contain pigments and dyes, including brightness agents, that can flow through the extremely thin liquid cosmetic flow grooves, which have a groove width dimension W1 of 0.05 mm or more and 0.2 mm or less.

[0043] (Liquid cosmetic material flow groove 40)

[0044] The liquid cosmetic flow groove 40 is an extremely narrow groove formed in the radial and axial directions on the outer periphery of the liquid cosmetic feeder 4 (see Figures 2, 3, 4, and 5). The groove width W1 of the liquid cosmetic flow groove 40 is preferably extremely narrow, ranging from 0.05 mm to 0.2 mm. The liquid cosmetic flow groove 40 connects to the applicator unit 2 at the front of the liquid cosmetic feeder 4 and to the liquid cosmetic tank 3 at the rear. The liquid cosmetic flow groove 40 supplies the liquid cosmetic P from the liquid cosmetic tank 3 to the applicator unit 2 primarily by capillary action. The cross-sectional shape of the liquid cosmetic flow groove 40 is preferably a substantially rectangular shape recessed vertically, and extends linearly in the axial direction while retaining its comb-like shape. The liquid cosmetic flow groove 40 is recessed from the outer periphery 43 of the liquid cosmetic feeder radially inward and is formed in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 leads to the brush portion at the front of the liquid cosmetic feeder 4 and to the liquid cosmetic tank 3 at the rear. (Shape of the liquid cosmetic flow groove 40) As shown in Figures 3 and 5, the liquid cosmetic flow groove 40 is formed in the liquid cosmetic feeder 4. In the cross-sections shown in Figures 3 and 5, the cross-sectional shape of each liquid cosmetic flow groove 40 is preferably formed as a substantially rectangular shape concave in the vertical direction. However, it does not necessarily have to be a strict rectangle and may be formed with a slight curve. For example, as shown in Figure 9(e), each liquid cosmetic flow groove 40 may be tapered. Each circumferential groove is formed on the periphery of the liquid cosmetic feeder in a comb-like shape. Furthermore, it is preferable that the axial length of each liquid cosmetic flow groove 40 extend linearly in the axial direction while maintaining the comb-like cross-section. However, it does not necessarily have to extend linearly in the axial direction and may extend in a curved or jagged shape. The liquid cosmetic flow groove 40 leads to the applicator unit 2 at the front of the liquid cosmetic feeder 4 and leads to the liquid cosmetic tank 3 at the rear.

[0045] As shown in Figure 3, it is preferable that the width W1 of each liquid cosmetic flow groove 40 of the feeder be constant in the up-down direction (vertical direction) in Figure 3 to facilitate release from the mold or slide core 65. The reason why the liquid cosmetic flow grooves 40 are formed in parallel comb-like shapes is due to the molding method described below. That is, this is due to the core shape of the slide core 65 or mold 62 used in the injection molding method described in detail below. The bottom of the liquid cosmetic flow groove 40 may be formed in various shapes, such as a U-shape (Figure 9(g)).

[0046] Each liquid cosmetic flow groove 40 is formed to extend in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 is recessed radially inward from the outer peripheral surface 43 of the liquid cosmetic feeder and is formed in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 opens into the applicator unit 2 at the front of the liquid cosmetic feeder 4 and opens into the liquid cosmetic tank 3 at the rear of the liquid cosmetic feeder 4. The liquid cosmetic flow groove 40 faces the inner peripheral surface of the hole 2a in the applicator unit 2 and communicates between the hole 2a in the applicator unit 2 and the liquid cosmetic storage space 30a in the liquid cosmetic tank 3 (see FIG. 1 ).

[0047] (Size of Liquid Cosmetic Flow Groove 40) In an embodiment of the present invention, the liquid cosmetic flow groove 40 is an extremely thin groove formed on the circumference of the liquid cosmetic feeder 4 ( FIG. 3 ). The term "extremely thin" refers to, for example, in FIG. 3 , the horizontal groove width W1 (left-right direction in FIG. 5 ) of each liquid cosmetic flow groove 40 being preferably 0.05 mm to 0.2 mm. Furthermore, the groove width W1 is more preferably 0.05 mm to 0.16 mm. Furthermore, the ratio of the groove width W1 of the liquid cosmetic flow groove 40 to the outer diameter D of the liquid cosmetic feeder 4 is, for example, 2.5% to 9.2%, preferably 2.5% to 8.2%. Furthermore, the vertical depth L1 (depth of the liquid cosmetic flow groove 40) of the liquid cosmetic flow groove 40 to the outer diameter D is preferably, for example, 25% to 40%.

[0048] Furthermore, in a cross section perpendicular to the axial direction of the liquid cosmetic feeder 4, the ratio of the area occupied by the liquid cosmetic flow groove 40 is preferably, for example, 5% or more, more preferably 10% or more, and even more preferably 20% or more.

[0049] (Number and Arrangement of Liquid Cosmetic Flow Grooves 40) In the cross section of FIG. 3, multiple liquid cosmetic flow grooves 40 are formed at intervals in the horizontal direction (y direction) as shown in FIG. 3. In this embodiment, eight or ten liquid cosmetic flow grooves 40 are formed, but the number of liquid cosmetic flow grooves 40 is not limited and can be increased or decreased as appropriate. The liquid cosmetic flow grooves 40 are formed parallel to each other in a comb-like shape. It is preferable that the liquid cosmetic flow grooves 40 are arranged parallel to each other. This differs from conventional liquid cosmetic feeders 4, in which the liquid cosmetic flow grooves 40 are formed radially toward the center point of the axis (see FIG. 10). This parallel shape (comb-like shape) facilitates demolding from the mold 62, as described below, and enables the liquid cosmetic feeder 4 to be manufactured by injection molding. The liquid cosmetic flow grooves 40 are arranged parallel to each other, but they do not have to be strictly parallel, as long as they are parallel enough to allow the comb-tooth plate members of the mold or slide core 65 to be released from the liquid cosmetic feeder, which is an injection-molded and solidified molded product.

[0050] (Horizontal grooves of the liquid cosmetic flow grooves 40) There is no particular limitation on the number of grooves in the liquid cosmetic flow grooves 40. The flow rate of the liquid cosmetic can be adjusted by the number of grooves formed. In the above embodiment, horizontal grooves (not shown) connecting adjacent liquid cosmetic flow grooves in the circumferential direction of the feeder may be further provided on the outer circumferential surface of the liquid cosmetic flow grooves 40. In other words, such horizontal grooves extend in the circumferential direction of the feeder, intersecting the liquid cosmetic flow grooves 40. Such horizontal grooves enable the liquid cosmetic P to be transferred between the liquid cosmetic flow grooves 40, and allow the liquid cosmetic P to flow more smoothly toward the front end.

[0051] (Modification of the liquid cosmetic material flow groove 40)

[0052] Modified examples of the liquid cosmetic flow grooves 40 are shown in Figure 9. As shown in (b), the number of liquid cosmetic flow grooves 40 may be increased or decreased. As shown in (c), the groove width W1 of the liquid cosmetic flow grooves 40 may be narrowed. As shown in (d), the groove width W1 of each liquid cosmetic flow groove 40 may be varied. As shown in (e), each liquid cosmetic flow groove 40 may be tapered. As shown in (f), the depth of each liquid cosmetic flow groove 40 may be varied. As shown in (g), the bottom of each liquid cosmetic flow groove 40 may be rounded. As shown in (h), the outer shape of each liquid cosmetic feeder may be as shown. As shown in (i), the number of slide cores 65 may be increased or decreased as shown. As shown in (j), flow grooves may be formed inside the liquid cosmetic feeder. As shown in (k), the size of the mold rib receiving portion 42 may be varied.

[0053] (Formation of Mold Rib Receiving Portion 42) In an embodiment of the present invention, as shown in Figures 2 and 4, the mold rib receiving portion 42 is formed as a concave groove in the axial direction on the outer peripheral surface 43 of the liquid cosmetic feeder 4. The shape of the mold rib receiving portion 42 is not limited as long as the liquid cosmetic feeder (the molded product) can be caught on the mold rib 623 during the demolding process. In an embodiment of the present invention, the mold rib receiving portion 42 is shaped to fit the shape of the mold rib 623. However, the shape of the mold rib receiving portion 42 is not limited to the above shape as long as the liquid cosmetic feeder (the molded product) can be caught on the mold rib 623 during the demolding process. Because the mold rib receiving portion 42 is formed, the mold rib receiving portion 42 of the liquid cosmetic feeder 4 (the molded product) abuts on the mold rib 623 of the mold 62 during the process of opening the slide core 65 during injection molding, allowing the liquid cosmetic feeder 4 to be released from the mold 62. The mold rib receiving portion 42 may be formed in the same shape (groove width, groove depth, and radial length of the groove) as the liquid cosmetic material flow groove 40. In this case, the mold rib receiving portion 42 can also function as the liquid cosmetic material flow groove 40. As described above, the inventors have succeeded in forming the liquid cosmetic material flow groove 40 by injection molding a liquid cosmetic material feeder, making it possible for the first time to use injection molding for the liquid cosmetic material feeder 4.

[0054] (Injection Molding Method) Next, with reference to FIG. 6 , the injection molding method for the liquid cosmetic feeder 4 of this embodiment will be described. The liquid cosmetic feeder 4 is manufactured by molding a synthetic resin material into a predetermined shape and size using an injection molding machine 60. In the present invention, the shape of the liquid cosmetic feeder can be completed within the injection molding process, eliminating the need for cutting processes such as front and rear end processing, or cutting to extend the entire length. Cutting processes such as front and rear end processing and cutting to extend the entire length are not required with the injection molding method of the present invention. The shape of the liquid cosmetic feeder 4 can be formed and completed entirely by the mold shape. The injection molding method for the liquid cosmetic feeder 4 of this embodiment will be described in detail below. The liquid cosmetic feeder 4 of this embodiment is manufactured by injection molding. The injection molding method of this embodiment is a technique in which synthetic resin 61, a plastic material melted at a high temperature, is injected into an injection mold 62, cooled, and then molded under high pressure. (Steps of Injection Molding Method) The steps of the injection molding method will be explained below.

[0055] 1. Preparing the material First, the material is temporarily stored in a hopper, then supplied little by little to the injection unit, and sent to the heated part of the injection unit by the drive device 64. 2. Clamping the mold 62 consists of two parts. One mold 62 is mated with the other mold 62 and clamped. In the injection molding of this embodiment, the mold 62 may be equipped with a slide core 65. 3. Injection The molten material is injected into the mold 62. 4. Holding pressure The mold 62 is maintained at a pressure that makes it easy for the injected material to solidify. 5. Cooling The material is cooled and solidified. 6. Opening the mold After confirming that the material has cooled and solidified sufficiently, the movable side of the mold is opened. 7. Removing the product The product is removed. As one side of the mold 62 is fixed, the molded product is pushed out and removed with an ejector pin 67.

[0056] (Injection molding machine 60) The liquid cosmetic feeder 4 of this embodiment can be manufactured using, for example, an injection molding machine 60 as shown in Fig. 6(a) . The injection molding machine 60 that can be used in this embodiment includes three parts: a drive device 64 that feeds the material, a nozzle 68 that heats the material with a heater 66 to make it ready for injection, and a mold clamping unit 63 for molding the material in a mold 62.

[0057] (Operation of injection molding machine 60) The injection molding die 62 is a metal die into which synthetic resin 61 is injected to form a specific shape. Basically, it consists of two dies 62, which are opened and closed by a die clamping unit 63.

[0058] (Mold 62) The mold 62 must ensure dimensional accuracy for a certain number of shots even while repeatedly applying pressure, heat, friction, etc., and therefore is made of hard and highly durable materials such as die steel, high-speed steel, cemented carbide, ceramics, etc. Fig. 7(a) is a cross-sectional view of a mold equipped with a sliding core 65, and Fig. 7(b) is a cross-sectional view of a mold without a sliding core.

[0059] (Structure of the Sliding Core 65) In the liquid cosmetic feeder 4 of this embodiment, as shown in FIG. 6(c), the liquid cosmetic feeder can be manufactured by combining the sliding core 65 with a mold. The sliding core 65 can be manufactured by bonding a first plate-shaped member 651 having a thickness of 0.1 mm and a second plate-shaped member 652 having a thickness of 0.2 mm. There are various methods for joining the first plate-shaped member 651 and the second plate-shaped member 652, and the following methods can be used, for example: Adhesive method: This method bonds metal plates using a metal adhesive. Depending on the type of adhesive, high strength and excellent durability can be achieved. Welding method: This method welds metal plates. Welding methods include arc welding, gas welding, and laser welding, and laser welding may be optimal for ultra-thin metal plates. Plate-shaped components having thicknesses of 0.1 mm and 0.2 mm are incorporated into the sliding core 65. This forms a comb-like core in the sliding core 65.

[0060] (Release from Mold 65 with Sliding Core) As shown in FIG. 6(b), the method for releasing from the mold 62 after injection involves the upper and lower sliding cores 65 being released from the angular pins 624 and moving up and down. At this point, the liquid cosmetic feeder 4, which is the injection-molded product, is held by the mold ribs 623 and adheres to the upper and lower sliding cores 65, preventing them from following. The injection-molded liquid cosmetic feeder 4 is then pushed out by the operation of the ejector pins 67 and completely released from the mold. First plate-shaped members 651 and second plate-shaped members 652 are fixed in an alternating arrangement to the sliding core 65 of the mold 62. In this embodiment, the first plate-shaped members 651, each 0.1 mm thick, and the second plate-shaped members 652, each 0.2 mm thick, are alternately fitted into the sliding core 65 of the mold 62. The molded product is removed from the mold 62 by opening the sliding core 65 up and down. In this embodiment, the mold 62 opens left and right and the slide core 65 opens up and down simultaneously. However, the mold 62 may be opened left and right first, and then the slide core 65 may be opened up and down sequentially. Also, in this embodiment, the liquid cosmetic feeder 4 is injection molded with its axis oriented perpendicular to the plane of the drawing (z-axis direction) as shown in Figure 6(b), but it may also be injection molded with its axis oriented horizontally (x-axis direction) as shown in Figure 6(c).

[0061] (Release from a Mold Without a Sliding Core) The aforementioned mold 62 with a sliding core has a complex structure, and the mold 62 of the present invention does not necessarily need to include a sliding core 65. The following mold 62 also falls within the scope of the present invention. That is, by forming the first plate-like member 651 and the second plate-like member 652 horizontally in a comb-like shape in the mold 62, injection molding is possible without the need for a sliding core 65 ( FIG. 7( b) ). To release the liquid cosmetic feeder 4 from the mold 62 after injection, as shown in FIG. 7( b), first, the left and right molds 62 are opened to the left and right by a mold opening / closing device (not shown). At this point, the liquid cosmetic feeder 4 is released from the right mold 62. The liquid cosmetic feeder 4, which is an injection-molded product, is then held by the mold ribs 623 and subsequently pushed out by the operation of the ejector pins 67, completely releasing it from the mold.

[0062] (Mold rib 623) In this embodiment, mold ribs 623 are formed near the center of each of the left and right molds 62 (FIG. 6(d)). When the slide core 65 of this embodiment opens up and down, the molded product is caught on these mold ribs 623. This allows the molded product to be easily removed from the slide core 65. The shape of the mold ribs 623 is not particularly limited as long as it allows the molded product to be easily removed from the slide core 65. For example, it may have any shape that can fit into a recess somewhere on the molded product. Furthermore, the mold ribs 623 may be formed on either the left or right mold 62. The inventors have succeeded in providing such a convex shape on the mold 62, thereby allowing the molded product to be easily removed from the mold 62.

[0063] Thereafter, the molded product can be completely removed from the mold 62 by pushing it up with the ejector pin 67. When the slide core 65 is opened from above and below, the molded product and the plate part of the mold 62 are in close contact with each other, so the molded product remains on one of the slide cores 65, making it impossible to remove the molded product from the mold 62.

[0064] To prevent this, it is necessary to leave the liquid cosmetic feeder 4 in the mold 62 when removing it from the mold 62. For this reason, in this embodiment, mold release ribs are formed on the mold 62 ( FIG. 6 c). In this embodiment, mold ribs 623 are formed in the center of both sides of the mold 62, but the mold ribs 623 may be formed at positions offset from the center as long as the mold release ribs have a shape that can temporarily hold the liquid cosmetic feeder 4 in the mold 62. Furthermore, they may be formed on either the male or female mold. Furthermore, there are no limitations on the shape, number, or length of the mold release ribs that can be used in the present invention as long as they have a shape that can temporarily hold the liquid cosmetic feeder 4 in the mold 62.

[0065] It has been said that it is impossible to use injection molding to create a shape like the liquid cosmetic feeder 4, which has a 0.1 mm groove running through it. However, extrusion molding involves extruding the workpiece through a relatively large mold 62, stretching it, and creating a thin shape, so it is possible to create a 0.1 mm groove shape with extrusion molding.

[0066] Because of this manufacturing method, conventional extrusion molding results in significant dimensional variation, particularly in the outer diameter (variation of about ±0.1 mm). Creating a liquid cosmetic feeder 4 for a liquid cosmetic applicator 1 with a 0.1 mm groove running through it using injection molding is something that would be unthinkable in the industry. In this study, we succeeded in expressing the structure within the mold 62 by laminating thin plates, such as 0.1 mm and 0.2 mm, to form the 0.1 mm groove, and thus successfully manufactured the liquid cosmetic feeder 4 of 1 using injection molding.

[0067] (Cosmetic Applicator) The liquid cosmetic feeder 4 of this embodiment can be attached to various liquid cosmetic applicators 1. Below, each part of the liquid cosmetic applicator 1 to which the liquid cosmetic feeder 4 of this embodiment can be attached will be described. In the following example, an eyeliner will be described as an example of the liquid cosmetic applicator 1. The liquid cosmetic feeder 4 of the present invention is a core provided to "relay" the liquid cosmetic P to the applicator part 2, and can be applied to any liquid cosmetic applicator 1 as long as it is rod-shaped, with its rear end immersed in the liquid cosmetic P and its front end connectable to the applicator part 2. In particular, the liquid cosmetic feeder 4 of this embodiment can be attached to eyeliner, eyebrow pencil, eyeshadow, concealer, etc.

[0068] (Applicator Part) The applicator part 2 is, for example, a brush, and is a fibrous aggregate made of a synthetic resin such as nylon or PBT (polybutylene terephthalate). The applicator part 2 is not limited to a brush, and may be, for example, a sintered pen type or one made of porous urethane. When the liquid cosmetic P contains solid matter, it is preferable that the applicator part 2 is a brush. In particular, when the liquid cosmetic P contains solid matter, it is preferable that the applicator part 2 be a bundle of soft, elastic, and flexible synthetic fibers such as nylon.

[0069] As shown in FIG. 1 , the applicator part 2 has a round rod shape extending in the axial direction (longitudinal direction) around the axis O. The applicator part 2 also has a conical shape with an outer diameter that gradually decreases from a midpoint in the axial direction toward the front end. As shown in FIG. 2 , a hole 2a that is recessed toward the front end is formed in the end face of the rear end of the applicator part 2. The hole 2a has a tapered shape with an inner diameter that gradually decreases from the rear end toward the front end. The inner diameter of the hole 2a may be equal to the outer diameter of the liquid cosmetic feeder 4 described below, or may be slightly larger than the outer diameter of the liquid cosmetic feeder 4. This may form a space (clearance) between the outer peripheral surface of the liquid cosmetic feeder 4 and the inner peripheral surface of the hole 2a, through which the liquid cosmetic P can flow.

[0070] Furthermore, an adhesive layer 20 that bundles the fibers of the applicator part 2 is provided at the end on the rear end side of the applicator part 2. The hole 2a penetrates the adhesive layer 20. The adhesive layer 20 is formed by, for example, adhesively bonding the fibers of the applicator part 2 to one another. The adhesive layer 20 has a disk shape centered on the axis O. The outer diameter of the adhesive layer 20 is slightly larger than the outer diameter of the applicator part 2, so that the adhesive layer 20 protrudes from the applicator part 2 toward the outer periphery in a flange-like shape.

[0071] (Liquid Cosmetic Tank 3) Returning to FIG. 1 , the liquid cosmetic tank 3 extends rearward from the rear end of the liquid cosmetic feeder 4. The liquid cosmetic tank 3 has a cylindrical outer tube 30 extending axially, and a tail plug 39 that closes the rear end of the outer tube 30. The space surrounded by the outer tube 30, the tail plug 39, and a pressure fluctuation buffer member 5 (described below) forms a liquid cosmetic storage space 30a that stores paint. The liquid cosmetic storage space 30a stores liquid paint as the liquid cosmetic P, or liquid paint containing solids. The liquid paint is, for example, a liquid cosmetic used for eyeliner.

[0072] The solid matter has a higher specific gravity than the liquid paint, and examples thereof include metal powder such as titanium or aluminum, glitter made by vapor deposition of gold, silver, aluminum, tin, etc., and inorganic substances such as glass beads. The viscosity of the liquid cosmetic P containing the solid matter is preferably, for example, about 30 mPa·s or less.

[0073] An agitator M is housed within the liquid cosmetic storage space 30a within the liquid cosmetic tank 3. The liquid cosmetic P within the liquid cosmetic tank 3 can be agitated by the agitator M by axially shaking the entire liquid cosmetic applicator 1. The shape of the agitator M is not limited, and may be, for example, a sphere, a cylinder, or a polyhedron such as a cube or rectangular parallelepiped. Furthermore, depending on the type of liquid cosmetic P, the agitator M may not necessarily be provided.

[0074] (Outer Cylinder) The outer cylinder 30 has a liquid cosmetic storage space 30a and a feeder storage area 30b extending further forward from the liquid cosmetic storage space 30a. The feeder storage area 30b is located radially outward of the liquid cosmetic feeder 4, overlapping the liquid cosmetic feeder 4 as viewed radially, and covering the liquid cosmetic feeder 4. The feeder storage area 30b also has a tapered shape in which the outer diameter gradually decreases from a midpoint in the axial direction toward the front end. As shown in Figure 2, the front end of the feeder storage area 30b is located radially outward of the applicator 2, overlapping the applicator 2 as viewed radially, and covering the applicator 2.

[0075] Furthermore, on the inner surface of the front end side of the outer tube portion 30, there are formed, spaced apart in the axial direction, an outer tube first step surface 31 having an annular shape centered on the axis O facing the rear end in the axial direction, and an outer tube second step surface 32 arranged rearward of the outer tube first step surface 31 and having an annular shape centered on the axis O. As a result, in the feeder accommodating region 30b of the outer tube portion 30, there are formed an outer tube first recess 33 and an outer tube second recess 34, which are recessed annularly from the inner peripheral surface of the outer tube portion 30 outward in the feeder radial direction and centered on the axis O. Therefore, the inner diameter of the outer tube portion 30 gradually decreases toward the front end side. In addition, an air circulation groove 30x is formed in the outer tube portion 30 in a part of the feeder circumferential direction, communicating with the outer tube first recess 33, extending in the axial direction, and opening on the end face on the front end side of the outer tube portion 30. Air is exchanged between the inside and outside of a buffer space K, which will be described later, via the air circulation grooves 30x, the outer cylinder first recess 33, and the outer cylinder second recess 34. In addition, an outer cylinder flange 35 is provided in the feeder accommodating region 30b of the outer cylinder portion 30, at a midpoint in the axial direction that is closer to the rear end side than the outer cylinder second step surface 32, and protruding annularly outward in the feeder radial direction (see FIG. 2).

[0076] (Inner Cylinder Portion) Furthermore, an inner cylinder portion 36 is provided between the outer cylinder portion 30 and the application portion 2. The inner cylinder portion 36 extends in the axial direction and engages with the fixing layer 20 and the outer cylinder portion 30. The inner cylinder portion 36 covers the rear end of the application portion 2 by pressing it down from the outside in the feeder radial direction. Specifically, an inner cylinder outer stepped surface 36a is formed on the outer peripheral surface of the inner cylinder portion 36, the inner cylinder outer stepped surface 36a having an annular shape centered on the axis O facing the front end side in the axial direction. This inner cylinder outer stepped surface 36a forms an outer protrusion 37 on the outer peripheral surface of the inner cylinder portion 36, the outer protrusion 37 having an annular shape centered on the axis O and protruding outward in the feeder radial direction. Therefore, the outer diameter of the inner cylinder portion 36 is larger at the rear end side than at the front end side.

[0077] The inner cylinder portion 36 is disposed such that the outer protrusion 37 of the inner cylinder portion 36 is disposed within the outer cylinder first recess 33 of the outer cylinder portion 30, and the inner cylinder outer step surface 36a of the inner cylinder portion 36 faces the outer cylinder first step surface 31 of the outer cylinder portion 30 in the axial direction. Thus, the inner cylinder outer step surface 36a of the inner cylinder portion 36 engages with the outer cylinder first step surface 31 of the outer cylinder portion 30, and the inner cylinder portion 36 engages with the outer cylinder portion 30. Furthermore, the inner peripheral surface of the inner cylinder portion 36 is formed with an inner cylinder inner step surface 36b that is disposed rearward of the inner cylinder outer step surface 36a and has an annular shape centered on the axis O facing the rearward. This inner cylinder inner step surface 36b forms an inner recess 38 on the inner peripheral surface of the inner cylinder portion 36 that is recessed outward in the feeder radial direction and has an annular shape centered on the axis O. The adhesive layer 20 is disposed within the inner recess 38 , and the inner cylinder 36 and the adhesive layer 20 are engaged with each other, and the outer cylinder 30 supports the applicator part 2 via the inner cylinder 36 .

[0078] (Outer Case) The outer case 6 abuts against the outer tube flange 35 of the outer tube portion 30 from the rear end side in the axial direction, and covers the outer tube portion 30 from the outside in the feeder radial direction on the rear end side of the outer tube flange 35. In other words, the outer case 6 is cylindrical with a bottom that extends axially about the axis O so that the outer tube portion 30 can be inserted. The outer tube portion 30 is fitted into the outer case 6, and the outer case 6 and the outer tube portion 30 are fixed together. A rear end space S2 is formed inside the outer case 6 in a region sandwiched between the bottom surface of the outer case 6 and the tail plug 39 of the liquid cosmetic tank 3 (see FIG. 1 ).

[0079] (Pressure Fluctuation Buffering Member 5) As shown in Figure 5, the pressure fluctuation buffering member 5 includes a feeder holding tube 50 and a buffering mechanism 51 that forms a buffer space K between the feeder holding tube 50 and the inner surface of the outer tube portion 30, radially outward of the feeder holding tube 50. The pressure fluctuation buffering member 5 is made of synthetic resin. When the liquid cosmetic P in the liquid cosmetic tank 3 is a water-based paint, the synthetic resin may be ABS resin, AS resin, PET resin, PBT resin, styrene resin, POM resin, polycarbonate, polyamide, modified polyphenylene ether, or the like. When the liquid cosmetic P in the liquid cosmetic tank 3 is an oil-based paint (particularly a paint whose main solvent is alcohol), the synthetic resin may be PE resin, PP resin, POM resin, PET resin, PBT resin, polyamide, or the like.

[0080] (Feeder Retaining Cylinder) The feeder retaining cylinder 50 extends in the axial direction and has a cylindrical main body tubular portion 52 centered on the axis O, through which the liquid cosmetic feeder 4 is inserted, and an extension portion 53 provided integrally with the main body tubular portion 52 at the rear end side of the main body tubular portion 52.

[0081] The liquid cosmetic feeder 4 is fitted into the tubular main body portion 52, so that the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 faces the inner circumferential surface of the tubular main body portion 52 in the feeder radial direction. The liquid cosmetic feeder outer surface 43 (see FIG. 3) of the liquid cosmetic feeder 4 contacts the inner circumferential surface of the tubular main body portion 52. The groove-to-groove dimension W2 (see FIG. 3) of the liquid cosmetic feeder outer surface 43 in the horizontal direction of the feeder is very small, and fitting the liquid cosmetic feeder 4 into the tubular main body portion 52 forms a very small gap (not shown) between the tubular main body portion 52 and the liquid cosmetic feeder 4. This small gap creates a space between the tubular main body portion 52 and the liquid cosmetic feeder 4, allowing horizontally adjacent liquid cosmetic flow grooves 40 to communicate with each other.

[0082] (Connecting Passage) Furthermore, a connecting flow path F that communicates with the liquid cosmetic flow groove 40 is formed in the main body tubular portion 52 of the pressure fluctuation buffering member 5. The formation of the liquid cosmetic flow groove 40 causes a larger amount of liquid cosmetic P to exist between the pressure fluctuation buffering member 5 and the liquid cosmetic feeder 4, but the connecting flow path F improves the entry of the liquid cosmetic P into the buffer space K, thereby preventing leakage of the liquid cosmetic P. The provision of the connecting flow path F allows air to move between the buffer space K and the liquid cosmetic storage space 30a, and the connecting flow path F allows the liquid cosmetic P to move between the buffer space K and the liquid cosmetic flow groove 40, effectively preventing leakage of the liquid cosmetic P.

[0083] In the above embodiment, horizontal grooves (not shown) may be further provided on the outer peripheral surface of the liquid cosmetic feeder 4 to connect adjacent liquid cosmetic flow grooves 40 in the circumferential direction of the feeder. That is, such horizontal grooves extend in the circumferential direction of the feeder, intersecting the liquid cosmetic flow grooves 40. Such horizontal grooves enable the liquid cosmetic P to be transferred between the liquid cosmetic flow grooves 40, and allow the liquid cosmetic P to flow more smoothly toward the front end.

[0084] Although the liquid cosmetic applicator 1 has been described above as being an eyeliner, it can also function satisfactorily when attached to a liquid cosmetic applicator 1 other than an eyeliner, such as an eyebrow applicator, a shadow liner, or a concealer.

[0085] (Buffering Mechanism) The buffering mechanism 51 is formed integrally with the feeder holding cylinder 50. The buffering mechanism 51 has a partition member 56 that protrudes annularly from the main body cylindrical portion 52 toward the outside in the feeder radial direction, centered on the axis O, at an axial midpoint of the main body cylindrical portion 52, a first convex member 57 formed on the outer circumferential surface of the main body cylindrical portion 52 rearward of the partition member 56, and a second convex member 58 formed on the outer circumferential surface of the main body cylindrical portion 52 frontward of the partition member 56.

[0086] Examples are specifically described below to enhance understanding of the present invention, but the scope of the present invention is not limited to the following examples.

[0087] Example 1: A liquid cosmetic feeder 4 was manufactured by injection molding, and an eyeliner was manufactured using it. In this Example 1, no cutting processes, such as front and rear end machining, were performed. The mold 62 for molding the liquid cosmetic feeder 4 was manufactured by bonding together thin plates, e.g., 0.1 mm or 0.2 mm thick (FIG. 6(c)). The mold 62 had a comb-like shape corresponding to the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4, which had a groove width W1 of 0.1 mm. The liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 was then successfully manufactured by injection molding using an injection molding machine 60 (FIG. 6) equipped with this mold 62. The liquid cosmetic feeder 4 manufactured by injection molding was then incorporated into a feeder holding tube 50 to manufacture the liquid cosmetic applicator 1 (eyeliner) (FIG. 4). In Figure 4, the liquid cosmetic feeder 4 was fixed by press-fitting into the feeder holding tube 50. In this example, the injection molding method was used to suppress variation in the outer diameter dimension D of the liquid cosmetic applicator 1 to within ±0.02 mm, thereby reducing the assembly defect rate. Furthermore, the assembly defect rate for the liquid cosmetic applicator 1 produced by the injection molding method was 0 out of 100 units (0% defect rate). Considering that the defect rate for Comparative Example 1 below was 35%, it was confirmed that the injection molding method and liquid cosmetic feeder 4 of the present invention can produce a liquid cosmetic feeder 4 with excellent dimensional stability.

[0088] (Example 2) The eyeliner shown in Fig. 5 was produced as Example 2. The difference from Example 1 is that the liquid cosmetic feeder 4 was fixed to the main body tubular portion 52 by providing a step to prevent it from coming off (it was not press-fitted). As a result, it differed from the eyeliner of Example 1 in terms of matching with the formulation, prevention of the brush tip splitting, assembly method, etc.

[0089] Next, the performance of the liquid cosmetic applicator 1 of Example 1 incorporating the liquid cosmetic feeder 4 manufactured by the above-described injection molding was confirmed.

[0090] Comparative Example 1 When the molding method was extrusion molding under the same conditions as in Example 1, 17 of 48 outer capillary thin tube bodies in Example 1 were defectively assembled (a defective rate of 35%).

[0091] (Performance test 1: Performance test using dye as liquid cosmetic) Formulation: Dye (contains brightener) Brown (contains brightener) Purple (contains brightener) Pink (contains brightener)

[0092] ■ Injection-molded outer capillary tube (outer diameter φ1.8, groove width 0.1 mm, number of grooves 8)

[0093] 1. Writing Test (Test Method) 200 lines of approximately 4 cm length were written on a piece of high-quality paper using one liquid cosmetic applicator 1, and the handwriting was visually checked for smearing.

[0094] (Number of tests) n = 1 (Test results) In brown (containing brightness agent), the handwriting was good with no smearing. In purple (containing brightness agent), the handwriting was good with no smearing. In pink (containing brightness agent), the handwriting was good with no smearing. In all dye formulations, the liquid cosmetic applicator 1 performed satisfactorily and produced good results in practical use.

[0095] 2. Aging test (Test method) The pens were placed with the nib facing up, sideways, and down in a thermostatic chamber at 40°C or higher for one month, and then ten lines of approximately 4cm length were written on high-quality paper to check for smearing of handwriting.

[0096] (Number of tests) Upward, sideways, downward n = 3 each

[0097] (Test results) In all cases, whether facing up, sideways, or down, brown (containing brightness agent) left good handwriting with no smearing. purple (containing brightness agent) left good handwriting with no smearing. pink (containing brightness agent) left good handwriting with no smearing. In the above time-lapse test, no smearing occurred in any of the formulations. Good handwriting. It can be said that the liquid cosmetic applicator 1 performed satisfactorily. The results were good for practical use.

[0098] 3. Forced pump test (Test method) The product is left facing down in a constant temperature bath at 40°C or higher for 24 hours. After 24 hours, it is removed from the constant temperature bath and immediately turned face down and the cap is fitted and refitted 100 times.

[0099] (Number of tests) n = 3

[0100] (Test results) Brown (containing brightness agent): No leakage even after 100 uses Purple (containing brightness agent): No leakage even after 100 uses Pink (containing brightness agent): No leakage even after 100 uses All of the liquid cosmetic applicators 1 performed satisfactorily. These were good results for practical use.

[0101] 4. Half-cap liquid leakage test (Test method) Place the cap half-open and facing downwards in a thermostatic chamber at 40°C or higher and leave for 24 hours. After that, remove from the thermostatic chamber and check for leakage. (Number of tests) n = 3

[0102] (Test results) Brown (containing brightening agent) No leakage Purple (containing brightening agent) No leakage Pink (containing brightening agent) No leakage All of the liquid cosmetic applicators 1 performed satisfactorily. The results were favorable for practical use.

[0103] 5. Decompression test (Formulation) Contains pink brightener (Test method) Remove the cap, point the pen tip downwards, and reduce the pressure from 1 atm. Once reduced, observe for 1 minute to check for leakage. (Test method) n=3 (Test results) No leakage was confirmed. The liquid cosmetic applicator 1 performed satisfactorily. The results were favorable for practical use.

[0104] (Performance Test 2: Performance Test Using Liquid Cosmetic P as Pigment) Next, the number of grooves was increased to 10, and a writing test was carried out on a liquid cosmetic using liquid cosmetic P as a pigment.

[0105] ●Formulation: Pigment (no brightener) Black Brown Brown Black Green

[0106] ■ Injection molded outer capillary tube (outer diameter φ1.8, groove width 0.1 mm, number of grooves 10) Written test

[0107] (Test method) 200 lines of approximately 4 cm length were written on high-quality paper with one liquid cosmetic applicator 1, and the handwriting was visually checked for smearing. (Number of lines tested) n=1 (Test results) Black: Good handwriting with no smearing Brown: Good handwriting with no smearing Brown-black: Good handwriting with no smearing Green: Good handwriting with no smearing All of the liquid cosmetic applicators 1 performed satisfactorily. The results were favorable for practical use.

[0108] Finally, we will report the results of a written test on a pigment formulation containing a high-brightness agent.

[0109] (Performance test 3: Test using pigments containing brighteners) Formulation: Pigment (contains brighteners) Red (contains brighteners) Blue (contains brighteners) Lavender (contains brighteners) Green (contains brighteners) Navy (contains brighteners) Pink (contains brighteners) Brown (contains brighteners) Brown (contains brighteners)

[0110] ■ Injection-molded outer capillary thin tube (outer diameter φ1.9, groove width 0.13 mm, 12 grooves, two of which serve as both mold rib receiving grooves and liquid cosmetic flow grooves)

[0111] 1. Writing Test (Test Method) 200 lines of approximately 4 cm length were written on a piece of high-quality paper using one liquid cosmetic applicator 1, and the handwriting was visually checked for smearing.

[0112] (Test results) Red (contains brightener): Handwriting was good with no smearing Blue (contains brightener): Handwriting was good with no smearing Lavender (contains brightener): Handwriting was good with no smearing Green (contains brightener): Handwriting was good with no smearing Navy (contains brightener): Handwriting was good with no smearing Pink (contains brightener): Handwriting was good with no smearing Brown (contains brightener): Handwriting was good with no smearing Brown (contains brightener): Handwriting was good with no smearing

[0113] All formulations produced clear handwriting with no smudges, resulting in good results. The product performed satisfactorily as an applicator for liquid cosmetics such as eyeliner, eyebrow pencil, eyeshadow liner (a cosmetic applicator for applying makeup to the under-eye bags on the face), and concealer. This resulted in good results in practical use.

[0114] The liquid cosmetic feeder 4 of the present invention smoothly guides and discharges the liquid cosmetic P.

[0115] DESCRIPTION OF SYMBOLS 1: Liquid cosmetic applicator 1 2: Applicator member 2a: Hole 3: Liquid cosmetic tank 4: Liquid cosmetic feeder 5: Pressure fluctuation buffer member 6: Outer case 20: Adhesion layer 30: Outer cylinder portion 30a: Liquid cosmetic storage space 30b: Feeder storage area 30x: Air flow groove 31: First stepped surface of outer cylinder 32: Second stepped surface of outer cylinder 33: First recessed portion of outer cylinder 34: Second recessed portion of outer cylinder 35: Outer cylinder flange 36: Inner cylinder portion 36a: Outer stepped surface of inner cylinder 36b: Inner stepped surface of inner cylinder 37: Outer convex portion 38: Inner recess 39: Tail plug 40: Liquid cosmetic flow groove 42: Mold rib receiving portion 43: Outer peripheral surface of liquid cosmetic feeder 44: Step portion 50 : Feeder holding cylinder 51 : Buffer mechanism 52 : Main body cylinder portion 53 : Extension portion 56 : Partition member 57 : First convex member 58 : Second convex member 60 : Injection molding machine 61 : Synthetic resin 62 : Mold 623 : Mold rib 624 : Angular pin 63 : Mold clamping unit 64 : Drive unit 65 : Slide core 651 : First plate-shaped part 652 : Second plate-shaped part 66 : Heater 67 : Ejector pin 68 : Nozzle D : Outer diameter F : Connecting flow path K : Buffer space L1 : Depth dimension of liquid cosmetic material flow groove 40 M : Stirring member O : Axis line P : Liquid cosmetic material S1 : Front end space S2 : Rear end space W1 : Groove width dimensionW2: Groove dimension

Claims

1. A liquid cosmetic feeder for use in a liquid cosmetic applicator, said liquid cosmetic feeder being injection molded from a synthetic resin, said liquid cosmetic feeder having extremely fine liquid cosmetic flow grooves formed therein.

2. The liquid cosmetic feeder according to claim 1, further comprising a mold rib receiving portion.

3. The liquid cosmetic feeder according to claim 2, wherein the liquid cosmetic flow groove has a cross-sectional shape like the teeth of a comb.

4. The liquid cosmetic feeder according to claim 3, wherein the groove width W1 of said liquid cosmetic flow groove is 0.05 mm or more and 0.2 mm or less.

5. A method for manufacturing a liquid cosmetic feeder, in which extremely fine liquid cosmetic flow grooves for flowing the liquid cosmetic are formed on the outer periphery by injection molding, in which heated and melted synthetic resin material is injected into a mold and cooled to obtain a molded product.

6. The method for producing the liquid cosmetic feeder according to claim 5, wherein the method does not include a post-process of cutting.

7. The method for producing the liquid cosmetic feeder according to claim 5, further comprising the step of opening a slide core in the injection molding step.

8. The method for manufacturing the liquid cosmetic feeder according to claim 5, wherein the liquid cosmetic feeder is formed with a liquid cosmetic flow groove that fits into a plate-like member of the mold.

9. A method for manufacturing the liquid cosmetic feeder according to claim 5, wherein the liquid cosmetic feeder is formed with a mold rib receiving portion and a liquid cosmetic flow groove that fits into a plate-shaped member of the slide core.

10. The method for manufacturing the liquid cosmetic feeder according to claim 5, wherein the cross-sectional shape of the liquid cosmetic flow groove is comb-shaped.

11. The method for manufacturing the liquid cosmetic feeder according to claim 10, wherein the groove width dimension W1 of the liquid cosmetic flow groove is 0.05 mm or more and 0.2 mm or less.

12. A liquid cosmetic feeder manufactured by the method according to any one of claims 5 to 11.

13. A liquid cosmetic applicator comprising the liquid cosmetic feeder according to claim 12.

14. The liquid cosmetic applicator according to claim 13, wherein the liquid cosmetic applicator is an eyeliner.

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