Liquid cosmetic feeder and liquid cosmetic applicator

Abstract

[Problem] A liquid cosmetic feeder is provided that can be manufactured without extrusion molding. A liquid cosmetic applicator such as an eyeliner, an eyebrow, a shadow liner, and a concealer is provided that can smoothly guide and discharge paint using the liquid cosmetic feeder. [Solution] As the liquid cosmetic feeder used for the liquid cosmetic applicator, the liquid cosmetic feeder is a liquid cosmetic feeder that is injection-molded out of a synthetic resin. The liquid cosmetic feeder is formed with an ultrafine liquid cosmetic flow groove.

Description

TECHNICAL FIELD

[0001] The present invention relates to a liquid cosmetic applicator 1 such as an eyeliner, an eyebrow, a shadow liner, and a concealer. In particular, the present invention relates to an injection molding method of a liquid cosmetic feeder mounted on the liquid cosmetic applicator 1, and the liquid cosmetic feeder and the liquid cosmetic applicator 1.BACKGROUND ART

[0002] An eyeliner, an eyebrow, a shadow liner, a concealer, and the like are known as the liquid cosmetic applicator 1. For example, in a liquid cosmetic container described in Patent Literature 1, a liquid paint is guided to a brush portion through a relay core.

[0003] In a liquid cosmetic applicator described in Patent Literature 2, it is described "a material of a member constituting a housing portion can be, for example, a cylindrical member formed by extrusion molding or injection molding out of a synthetic resin material such as polypropylene, polyethylene, polybutylene terephthalate, polyethylene terephthalate, or the like, considering permeability of gas and liquid tightness of a connecting portion".

[0004] In a liquid applicator described in Patent Literature 3, a liquid retention member or a relay core of the liquid applicator is formed by extrusion molding.CITATION LISTPATENT LITERATURE

[0005] Patent Literature 1: JPS59-125314U Patent Literature 2: JP2019-193698A Patent Literature 3: JP2015-024584A SUMMARY OF INVENTIONTECHNICAL PROBLEM

[0006] Extrusion molding is a method in which a material inserted from an inlet is heated in a heating cylinder and passed through an extrusion port of a mold to form a certain shape. Since the material is cooled and cured after being extruded, a molded product has the same cross-sectional shape regardless of where the molded product is cut.

[0007] In extrusion molding, a synthetic resin pellet is pushed into an extrusion mold while being heated and dissolved using a heater, and then molded and dissolved plastic is cooled and solidified. Since the dissolved plastic constantly comes out of the extrusion mold, it is not possible to ensure sufficient cooling time with the extrusion mold alone, so the dissolved plastic is supported by a sizing die to prevent deformation while passing through a cooling device. After leaving the sizing die, the material passes through a cooling water tank and is pulled by a pick-up machine while being cut into a required size.

[0008] An extrusion molding process is sequentially as follows in steps 1 to 5.

[0009] 1. Extrusion, 2. Mold, 3. Sizing die (water tank), 4. Pick-up machine, 5. Cutting machine.

[0010] In the case of a liquid cosmetic feeder 4 of the liquid cosmetic applicator 1, the steps 1 to 5 above are followed by post-processes of steps 6 and 7 described below.

[0011] 6. Cutting processing process, 7. Full-length cutting in some cases.

[0012] In other words, in the case of the liquid cosmetic feeder 4 by extrusion molding, a cutting processing process such as front end processing and rear end processing is required. Front end processing and rear end processing are used to form a front end shape and a rear end shape of the liquid cosmetic feeder 4 by performing cutting processing on a front end and a rear end of the liquid cosmetic feeder 4. Then, in the extrusion molding, a full-length cutting process that cuts a full-length is necessary in some cases.

[0013] Burr easily occurs in the cutting processing such as the front end processing, the rear end processing, and the like. If there are many burrs, a liquid cosmetic flow groove 40 will be blocked, and a liquid cosmetic discharge will be poor. Therefore, it is necessary to add a deburring process in some cases. Due to the addition of manufacturing processes such as the front end processing, the rear end processing, and the like as a post-process, it is also disadvantageous in terms of delivery time and cost.

[0014] In the case of the liquid cosmetic feeder 4 formed by extrusion molding, since the workpiece is extended after extrusion, a variation in dimension of the liquid cosmetic feeder 4, especially an outer diameter, becomes large (variation of about ± 0.1 mm).

[0015] Therefore, when assembling the liquid cosmetic applicator 1, some parts have a large outer diameter and cannot be inserted into a mating part, while others have a small outer diameter and are easily pulled out of the mating part, leading to assembly defects.(Dimension Stabilization)

[0016] In extrusion molding, a variation of an outer diameter dimension D of the liquid cosmetic feeder 4 is ± 0.1 mm, which is very large. Therefore, when assembling the liquid cosmetic applicator 1, some parts have a large outer diameter and cannot be inserted into the mating part, while others have a small outer diameter and are easily pulled out of the mating part. An object of the present invention is to reduce the variation of the outer diameter dimension D of the liquid cosmetic feeder 4 and stabilize the dimension.(Process Simplification)

[0017] Another object of the present invention is to enable stable molding of shape without front end processing, rear end processing, and the like.

[0018] Another object of the present invention is to manufacture the liquid cosmetic feeder 4 in a low cost and a short time without front end processing, rear end processing, and the like.(No Deburring Process Required)

[0019] In the extrusion molding method in the related art, burr occurs during front end processing, rear end processing, and the like as a post-process. Since burrs hinder a flow of liquid cosmetics, this deburring process is absolutely necessary. A further object of the present invention is to manufacture the liquid cosmetic feeder 4 that does not require this deburring process.

[0020] Therefore, an object of the present invention is to provide the liquid cosmetic feeder 4 with no variation in dimension, especially the outer diameter, of the liquid cosmetic feeder 4 by an injection molding method without depending on extrusion molding. An object is to form the liquid cosmetic feeder 4 by an injection molding method. Then, a method of manufacturing the liquid cosmetic feeder 4, and the liquid cosmetic applicator 1 such as an eyeliner, an eyebrow, a shadow liner, and a concealer that is provided with the liquid cosmetic feeder 4 and can smoothly guide and discharge paint are provided.SOLUTION TO PROBLEM

[0021] (1) A liquid cosmetic feeder according to an aspect of the present invention to achieve the above objects is a liquid cosmetic feeder used for a liquid cosmetic applicator, in which the liquid cosmetic feeder is a liquid cosmetic feeder that is injection-molded out of a synthetic resin, and the liquid cosmetic feeder is formed with an ultrafine liquid cosmetic flow groove. (2) In the liquid cosmetic feeder, the liquid cosmetic feeder may be further formed with a mold rib receiving portion. (3) In the liquid cosmetic feeder, a cross-sectional shape of the liquid cosmetic flow groove may be a comb shape. (4) In the liquid cosmetic feeder, a groove width dimension W1 of the liquid cosmetic flow groove may be 0.05 mm or more and 0.2 mm or less. (5) A method of manufacturing a liquid cosmetic feeder according to an aspect of the present invention is a method of manufacturing a liquid cosmetic feeder, in which an ultrafine liquid cosmetic flow groove for flowing a liquid cosmetic is formed on an outer periphery, by an injection molding method in which a heat-melted synthetic resin material is injected into a mold and cooled to obtain a molded product. (6) The method of manufacturing the liquid cosmetic feeder may be a method of manufacturing the liquid cosmetic feeder that does not include a cutting processing process, which is a post-process. (7) The method of manufacturing the liquid cosmetic feeder may be a method of manufacturing the liquid cosmetic feeder that further includes a process of opening a slide core in a process of the injection molding method. (8) The method of manufacturing the liquid cosmetic feeder provides the method of manufacturing the liquid cosmetic feeder according to (5), in which the liquid cosmetic feeder is formed with a liquid cosmetic flow groove that fits on a plate-shaped member of the mold. (9) The method of manufacturing the liquid cosmetic feeder provides the method of manufacturing the liquid cosmetic feeder according to (7), in which the liquid cosmetic feeder is formed with a mold rib receiving portion 42 and a liquid cosmetic flow groove that fits on a plate-shaped member of the slide core. (10) The method of manufacturing the liquid cosmetic feeder may be the method of manufacturing the liquid cosmetic feeder according to (5), in which a cross-sectional shape of the liquid cosmetic flow groove is a comb shape. (11) The method of manufacturing the liquid cosmetic feeder may be the method of manufacturing the liquid cosmetic feeder according to (10), in which a groove width dimension W1 of the liquid cosmetic flow groove is 0.05 mm or more and 0.2 mm or less. (12) The liquid cosmetic feeder may be a liquid cosmetic feeder manufactured by the manufacturing method according to any of (5) to (11). (13) A liquid cosmetic applicator according to an aspect of the present invention may be a liquid cosmetic applicator including the liquid cosmetic feeder according to (13) described above. (14) The liquid cosmetic applicator may be an eyeliner. ADVANTAGEOUS EFFECTS OF INVENTION

[0022] The present invention provides the liquid cosmetic feeder 4 by the injection molding method without depending on extrusion molding.BRIEF DESCRIPTION OF DRAWINGS

[0023] [FIG. 1] FIG. 1 is a cross-sectional view of the liquid cosmetic applicator 1 including the liquid cosmetic feeder 4 according to an example of the present invention. [FIG. 2] FIG. 2 is an enlarged view of an A portion of FIG. 1. [FIG. 3] FIG. 3 is a diagram illustrating the liquid cosmetic feeder 4 (a front end with a tapered shape) of another example of the present invention. Part (a) is a side view, part (b) is a plan view, part (c) is a front view, part (d) is a rear view, part (e) is an A-A' cross-section, part (f) is a B-B' cross-section, and part (g) is a C-C' cross-section. [FIG. 4] FIG. 4 is a diagram illustrating the liquid cosmetic applicator 1 including the liquid cosmetic feeder 4 according to the example of FIG. 3. Part (a) is a side view, part (b) is a rear view, part (c) is an A-A' cross-section, and part (d) is an enlarged cross-section of a B portion. [FIG. 5] FIG. 5 is a diagram illustrating the liquid cosmetic feeder 4 according to yet another example of the present invention (having a step portion 44 formed at a front end) and the liquid cosmetic applicator 1 equipped with the same. Part (a) is a front view, part (b) is a side view, part (c) is a rear view, part (d) is a plan view, part (e) is a rear view, part (f) is an enlarged view of B, part (g) is a C-C cross-section, part (h) is an A-A cross-section, part (i) is a D-D cross-section, part (j) is an enlarged view of E, and part (k) is a partial cross-section. [FIG. 6] FIG. 6 is a schematic diagram illustrating the operation of an injection molding machine 60 used in manufacture of the liquid cosmetic feeder 4 according to an example of the present invention. Part (a) is a schematic diagram of the injection molding machine 60, part (b) is a schematic diagram of a release process (a direction of an axis O of the liquid cosmetic feeder 4 is oriented in a direction orthogonal to an x-axis and a y-axis), part (c) is a schematic diagram of the release process, which is another embodiment of the present invention (the direction of the axis O of the liquid cosmetic feeder 4 is oriented in the y-axis direction), part (d) is an enlarged view of an A portion, and part (e) is an enlarged view of a B portion. [FIG. 7] FIG. 7 is a cross-sectional view of a mold 62 corresponding to the liquid cosmetic feeder 4 of FIG. 3. Part (a) is a cross-sectional view of the mold 62 with a slide core 65, and part (b) is a cross-sectional view of the mold 62 without a slide core. [FIG. 8] FIG. 8 is a diagram illustrating a modification of the liquid cosmetic feeder 4 according to an example of the present invention. Parts (a) and (b) are diagrams of the liquid cosmetic feeder of the example of FIG. 1, parts (c) and (d) are diagrams of the liquid cosmetic feeder 4 of the example of FIG. 4, and parts (e) and (f) are diagrams of the liquid cosmetic feeder 4 of the example of FIG. 5. [FIG. 9] FIG. 9 is a cross-sectional view illustrating a modification of the liquid cosmetic feeder 4 according to the present invention. [FIG. 10] FIG. 10 is a cross-sectional view of the liquid cosmetic feeder 4 in the related art. DESCRIPTION OF EMBODIMENTS

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings using an eyeliner as an example of the liquid cosmetic applicator 1.(Overall Configuration of Liquid Cosmetic Applicator 1)

[0025] First, as illustrated in FIG. 1, the liquid cosmetic applicator 1 is rod-shaped and supplies a liquid cosmetic P from a rear end side to a front end side, and causes the liquid cosmetic P to be discharged from the front end side.

[0026] The liquid cosmetic applicator 1 includes an application portion 2 that discharges the liquid cosmetic P, a liquid cosmetic tank 3 that forms a liquid cosmetic storage space 30a that accommodates the liquid cosmetic P, the liquid cosmetic feeder 4 that supplies paint from the liquid cosmetic tank 3 to the application portion 2, a pressure fluctuation buffer member 5 that buffers pressure fluctuation in the liquid cosmetic storage space 30a, and an outer case 6 that is provided on an outer peripheral side of the pressure fluctuation buffer member 5.(Overall Shape of Liquid Cosmetic Feeder 4)

[0027] Next, the liquid cosmetic feeder 4 of the present embodiment will be described. The liquid cosmetic feeder 4 is used for a liquid cosmetic applicator. The liquid cosmetic feeder supplies the liquid cosmetic P to the application portion 2, that is, the liquid cosmetic feeder 4 is a core provided for "relaying" the liquid cosmetic P to the application portion 2. An example of the liquid cosmetic feeder 4 according to an embodiment of the present invention is illustrated in FIG. 3. As illustrated in FIG. 3, the liquid cosmetic feeder 4 has, for example, a round rod shape. A rear end portion of the liquid cosmetic feeder 4 is immersed in the liquid cosmetic P, and the liquid cosmetic P is sucked up to the front end side by capillary force of the liquid cosmetic feeder 4. A front end portion of the liquid cosmetic feeder 4 is covered with the application portion 2, and the liquid cosmetic P absorbed by the capillary force can be supplied to the application portion 2 from inside of a rear end portion of the application portion 2.

[0028] A shape of the liquid cosmetic feeder 4 may have a tapered shape at the front end as illustrated in part (c) of FIG. 8 or form a step shape at the front end as illustrated in part (e) of FIG. 8. The liquid cosmetic feeder may be cut off as illustrated in part (a) of FIG. 8 without forming a tapered portion or the step portion 44 at the front end or the rear end.

[0029] Hereinafter, in the present specification, a direction orthogonal to an axial direction, that is, a radial direction of the liquid cosmetic feeder 4 is a feeder radial direction. A circumferential direction of the liquid cosmetic feeder 4 is taken as a feeder circumferential direction. A vertical direction is, for example, an up-down direction (y-axis direction) of the drawings in FIGS. 3 and 5. A horizontal direction is, for example, a left-right direction (x-axis direction) of the drawings in FIGS. 3 and 5. A z-axis direction refers to an axis orthogonal to the x-axis and the y-axis in the orthogonal coordinate axis system, and the x-axis is the horizontal direction, the y-axis is the vertical direction, and the z-axis is a depth direction.(Arrangement of Liquid Cosmetic Feeder 4)

[0030] In the present embodiment, the liquid cosmetic feeder 4 is inserted into a hole 2a from the rear end side of the application portion 2, as illustrated in FIG. 1, and is provided in the liquid cosmetic applicator 1. In other words, the liquid cosmetic feeder 4 is inserted into the application portion 2 and used for the liquid cosmetic applicator 1. However, as long as the liquid cosmetic P can be flown to the application portion 2, the hole 2a is not necessarily required.

[0031] Further forward than an end surface of the front end side of the liquid cosmetic feeder 4, a conical-shaped front end space S1 is formed between the liquid cosmetic feeder 4 and an inner surface of the hole 2a. An end of the rear end side of the liquid cosmetic feeder 4 is disposed in the liquid cosmetic storage space 30a of the liquid cosmetic tank 3 described later (see FIG. 1).(Material of Liquid Cosmetic Feeder 4)

[0032] The liquid cosmetic feeder 4 is formed of a synthetic resin material. Synthetic resin materials include polyacetal (POM), polyamide (PA) <nylon>, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polycarbonate (PC), and the like.(Manufacturing Method of Liquid Cosmetic Feeder 4)

[0033] The present inventors have succeeded in the manufacturing method of the liquid cosmetic feeder 4 by an injection molding method for the first time.

[0034] Furthermore, the injection molding method in the related art was considered incapable of producing the liquid cosmetic feeder 4 with a round rod shape, featuring an ultrafine groove with the groove width dimension W1 of the liquid cosmetic flow groove 40 of about 0.1 mm, formed in both the radial and axial directions, as illustrated in FIG. 10.

[0035] The present inventors have invented a shape structure of the mold 62 described in detail below, and succeeded in manufacturing the liquid cosmetic feeder 4 with a rod shape with an ultrafine groove formed in the radial and axial directions, with the groove width dimension W1 of the liquid cosmetic flow groove 40 of about 0.1 mm, using an injection molding method. The plastic liquid cosmetic feeder 4 of the embodiment of the present invention is the liquid cosmetic feeder 4 in which an ultrafine groove with the groove width dimension W1 of the liquid cosmetic flow groove 40 of 0.1 mm is formed on the outer periphery of the liquid cosmetic feeder 4 (FIG. 3).

[0036] Therefore, manufacturing the liquid cosmetic feeder 4 using an injection molding method was considered impossible in the related art and was an unexpected development. In the extrusion molding in the related art, the material was extruded from the relatively large mold 62 and the workpiece was extended to build a thin shape. Therefore, it was possible to form a groove shape of about 0.1 mm on a liquid cosmetic feeder outer peripheral surface 43. However, significant variations occurred in the dimensions of the molded liquid cosmetic feeder 4. In particular, many variations occurred in the outer diameter of the liquid cosmetic feeder 4 (variation of about ± 0.1 mm).

[0037] This time, in order for the groove width dimension W1 of the liquid cosmetic flow groove 40 to form a groove of 0.1 mm, the structure in the mold 62 could be expressed by lamination of thin plates such as 0.1 mm, 0.2 mm, and the like, and thus the tubular body, which is the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1, was successfully manufactured by injection molding.

[0038] The liquid cosmetic feeder 4 has been integrally molded by forming the shape of the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 of interest into a comb shape, using an injection molding method described in detail below.(Liquid Cosmetic)

[0039] A liquid cosmetic that can be used for the liquid cosmetic applicator 1 of the present invention is a type of cosmetic that is liquid-like. An example is a liquid cosmetic used for an eyeliner or the like. Liquid cosmetics include facial cleansers, toners, emulsions, and serums. In the liquid cosmetic applicator 1 of the present invention, the groove width dimension W1 allows to include a pigment and a dye including a brightness agent that can circulate in an ultrafine liquid cosmetic flow groove of 0.05 mm or more and 0.2 mm or less.(Liquid Cosmetic Flow Groove 40)

[0040] The liquid cosmetic flow groove 40 is an ultrafine groove formed in the radial and axial directions on the outer periphery of the liquid cosmetic feeder 4 (see FIGS. 2, 3, 4, and 5). The groove width dimension W1 of the liquid cosmetic flow groove 40 is ultrafine, preferably being 0.05 mm or more and 0.2 mm or less. The liquid cosmetic flow groove 40 flows to the application portion 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 application portion 2 mainly by capillary action.

[0041] The cross-sectional shape of the liquid cosmetic flow groove 40 is formed in a substantially rectangular shape recessed in the vertical direction, and preferably formed in a linear manner with a comb shape in the axial direction. The liquid cosmetic flow groove 40 is recessed from the liquid cosmetic feeder outer peripheral surface 43 toward the inner side of the feeder in the radial direction and is formed in the axial direction of the liquid cosmetic feeder 4.

[0042] Each liquid cosmetic flow groove 40 flows 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 Liquid Cosmetic Flow Groove 40)

[0043] As illustrated in FIGS. 3 and 5, the liquid cosmetic flow groove 40 is formed in the liquid cosmetic feeder 4. In the cross-section in FIGS. 3 and 5, the cross-sectional shape of each of the liquid cosmetic flow grooves 40 is preferably formed in a substantially rectangular shape recessed in the vertical direction. However, the shape does not necessarily have to be a strict rectangle and may form some curves. For example, each of the liquid cosmetic flow grooves 40 may be tapered, as illustrated in part (e) of FIG. 9.

[0044] Then, each peripheral groove is formed on the peripheral surface of the liquid cosmetic feeder in a comb shape. An axial length of the liquid cosmetic flow groove 40 is preferably formed by extending in a straight line in the axial direction with a cross-sectional surface in a comb shape. However, it does not necessarily need to extend in a straight line in the axial direction, and may extend in a curved or jagged manner. The liquid cosmetic flow groove 40 flows to the application portion 2 at the front of the liquid cosmetic feeder 4 and to the liquid cosmetic tank 3 at the rear.

[0045] As illustrated in FIG. 3, in each liquid cosmetic flow groove 40, the groove width dimension W1 of the liquid cosmetic flow groove 40 of the feeder is preferably formed at a constant width in the up-down direction (vertical direction) of FIG. 3 to facilitate release from the mold or the slide core 65. The reason why the liquid cosmetic flow groove 40 was formed in parallel in a comb shape is due to the molding method described later. That is, it is derived from a core shape of the slide core 65 or the 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 (part (g) of FIG. 9).

[0046] Each liquid cosmetic flow groove 40 is formed extending in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 is recessed from the liquid cosmetic feeder outer peripheral surface 43 toward the inner side of the feeder in the radial direction and is formed in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 opens to the application portion 2 at the front of the liquid cosmetic feeder 4 and to the liquid cosmetic tank 3 at the rear of the liquid cosmetic feeder 4. Then, the liquid cosmetic flow groove 40 faces the inner peripheral surface of the hole 2a in the application portion 2 and communicates with the hole 2a of the application portion 2 and the liquid cosmetic storage space 30a of the liquid cosmetic tank 3 (see FIG. 1).(Size of Liquid Cosmetic Flow Groove 40)

[0047] The liquid cosmetic flow groove 40 of the embodiment of the present invention forms an ultrafine groove on the periphery of the liquid cosmetic feeder 4 (FIG. 3). In FIG. 3, for example, ultrafine means that the groove width dimension W1 in the horizontal direction (the left-right direction of FIG. 5) of each liquid cosmetic flow groove 40 is preferably 0.05 mm or more and 0.2 mm or less. More preferably, the groove width dimension W1 is 0.05 mm or more and 0.16 mm or less. A ratio of the groove width dimension W1 in the liquid cosmetic flow groove 40 to the outer diameter dimension D of the liquid cosmetic feeder 4 is, for example, 2.5% or more and 9.2% or less, preferably 2.5% or more and 8.2% or less. Furthermore, a depth dimension (the depth dimension of the liquid cosmetic flow groove 40) L1 in the up-down direction (the left-right direction in FIG. 5) in the liquid cosmetic flow groove 40 with respect to the outer diameter dimension D is preferably 25% or more and 40% or less, for example.

[0048] Also, in the cross-section orthogonal to the axial direction in the liquid cosmetic feeder 4, the ratio of the occupied area occupied by the liquid cosmetic flow groove 40 may be, for example, 5% or more, furthermore 10% or more, and furthermore 20% or more.(Number and Arrangement of Grooves in Liquid Cosmetic Flow Groove 40)

[0049] In the cross-section in FIG. 3, a plurality of liquid cosmetic flow grooves 40 are formed at intervals in the horizontal direction (y-direction) as illustrated in FIG. 3. In the present embodiment, the number of liquid cosmetic flow grooves 40 is 8 or 10, but the number of liquid cosmetic flow grooves 40 is not limited and can be increased or decreased as appropriate. Then, the liquid cosmetic flow grooves 40 are formed in a comb shape in parallel.

[0050] The arrangement of the liquid cosmetic flow grooves 40 is preferably such that the liquid cosmetic flow grooves 40 are arranged in parallel with each other. This differs from the liquid cosmetic feeder 4 in the related art in that the liquid cosmetic flow groove 40 is formed in a radial manner toward a center point of the shaft (see FIG. 10). This parallel shape (comb shape) facilitates releasing from the mold 62 as described later, and it is possible to manufacture the liquid cosmetic feeder 4 by an injection molding method.

[0051] In the sense that the liquid cosmetic flow grooves 40 are arranged in parallel with each other, the meaning may not be applied to be strictly parallel, and the comb-shaped plate member of the mold or the slide core 65 may be formed in parallel enough to be released from the liquid cosmetic feeder, which is an injection molded and solidified molded product.(Transverse Groove of Liquid Cosmetic Flow Groove 40)

[0052] The number of grooves in the liquid cosmetic flow groove 40 is not particularly limited. A liquid cosmetic flow rate can be adjusted by the number of grooves formed. Note that in the above embodiment, a transverse groove (not illustrated) connecting the liquid cosmetic flow grooves adjacent to the feeder in the peripheral direction may be further provided on the outer peripheral surface of the liquid cosmetic flow groove 40. That is, such a transverse groove extends in the feeder circumferential direction across the liquid cosmetic flow groove 40. Such a transverse groove makes it possible to transfer the liquid cosmetic P between the liquid cosmetic flow grooves 40, and furthermore, it is possible to smoothly flow the liquid cosmetic P toward the front end side.(Modification of Liquid Cosmetic Flow Groove 40)

[0053] A modification of the liquid cosmetic flow groove 40 is illustrated in FIG. 9. As illustrated in part (b), the number of liquid cosmetic flow grooves 40 may increase or decrease. As illustrated in part (c), the groove width dimension W1 of the liquid cosmetic flow groove 40 may be narrower. As illustrated in part (d), the groove width dimension W1 of the respective liquid cosmetic flow grooves 40 may be mixed broadly and narrowly. As illustrated in part (e), the respective liquid cosmetic flow grooves 40 may be tapered. As illustrated in part (f), the depth of the respective liquid cosmetic flow grooves 40 may be varied. As illustrated in part (g), shapes of bottoms of the grooves of the respective liquid cosmetic flow grooves 40 may be a round bottom. As illustrated in part (h), shapes of external shapes of the respective liquid cosmetic feeders may be as illustrated. As illustrated in part (i), the number of slide cores 65 may be increased or decreased as illustrated. As illustrated in part (j), a flow groove may be formed inside the liquid cosmetic feeder. As illustrated in part (k), the size of the mold rib receiving portion 42 may be changed.(Formation of Mold Rib Receiving Portion 42)

[0054] In the embodiment of the present invention, as illustrated in FIGS. 2 and 4, the mold rib receiving portion 42 is formed as a recessed groove in the axial direction on the liquid cosmetic feeder outer peripheral surface 43 of the liquid cosmetic feeder 4. The shape of the mold rib receiving portion 42 is not limited to the shape, as long as the liquid cosmetic feeder, which is the molded product, can be caught in a mold rib 623 in the release process. In the embodiment of the present invention, the shape is made 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 4, which is the molded product, can be caught in the mold rib 623 in the release process.

[0055] Since the mold rib receiving portion 42 is formed, in the process of opening the slide core 65 during injection molding, the mold rib receiving portion 42 of the liquid cosmetic feeder 4, which is the molded product, contacts the mold rib 623 of the mold 62 and allows release from the mold 62.

[0056] The mold rib receiving portion 42 may be formed in the same shape (groove width, groove depth, and groove radial length) as the liquid cosmetic flow groove 40. In this case, the mold rib receiving portion 42 can also function as the liquid cosmetic flow groove 40.

[0057] As described above, the present inventors succeeded in forming the liquid cosmetic flow groove 40 by the injection molding method of the liquid cosmetic feeder, and for the first time, the injection molding method of the liquid cosmetic feeder 4 was possible.(Injection Molding Method)

[0058] Next, the injection molding method of the liquid cosmetic feeder 4 of the present embodiment will be described with reference to FIG. 6. The manufacturing method of the liquid cosmetic feeder 4 molds a synthetic resin material into a predetermined shape and size by the injection molding machine 60. In the present invention, since the shape of the liquid cosmetic feeder can be completed in the injection molding process, a cutting processing process such as front end processing and rear end processing, and a full length cutting process are not required. Cutting processing such as front end processing, rear end processing, and full-length extrusion cutting is not necessary in the injection molding method of the present invention. All of the mold shapes can be completed by forming the shape of the liquid cosmetic feeder 4 in the mold shape.

[0059] Hereinafter, the injection molding method of the liquid cosmetic feeder 4 according to the present embodiment will be described in detail. The liquid cosmetic feeder 4 of the present embodiment is manufactured by an injection molding method. The injection molding method of the present embodiment is a technique in which a synthetic resin 61 of a plastic material melted at a high temperature is injected into the mold 62 for injection molding, cooled, and molded by applying a high pressure.(Process of Injection Molding Method)

[0060] Procedures of the injection molding method are described below.1. Preparation of Material

[0061] First, the material is accumulated in a hopper once, supplied to an injection unit little by little, and fed into a heated portion of the injection unit by a driving device 64.2. Mold Clamping

[0062] The mold 62 consists of two parts. One mold 62 is aligned with the other mold 62 and mold clamping is performed. In the injection molding of the present embodiment, the mold 62 may be provided with the slide core 65.3. Injection

[0063] The melted material is injected into the mold 62.4. Pressure Retention

[0064] The injected material keeps the mold 62 at a pressure that is easy to solidify.5. Cooling

[0065] Cooling and solidification is performed.6. Mold Opening

[0066] After cooling and confirming sufficient solidification, a movable side of the mold is opened.7. Product Ejection

[0067] The product is ejected. Since one of the mold 62 is fixed, the molded product is pushed with an ejector pin 67 to be ejected.(Injection Molding Machine 60)

[0068] The liquid cosmetic feeder 4 of the present embodiment can be manufactured, for example, by the injection molding machine 60 as illustrated in part (a) of FIG. 6. The injection molding machine 60 that can be used in the present embodiment includes three parts: the driving device 64 that feeds the material, a nozzle 68 that heats the material using a heater 66 to make the material suitable for injection, and a mold clamping unit 63 for molding in the mold 62.(Operation of Injection Molding Machine 60)

[0069] The mold 62 for injection molding is a metal mold into which the synthetic resin 61 as materials is injected to form a predetermined shape. Basically, the mold consists of two molds 62 and is opened and closed by the mold clamping unit 63.(Mold 62)

[0070] Since the mold 62 needs to ensure dimensional accuracy at a constant number of shots while repeatedly applying pressure, heat, friction, and the like, die steel, high-speed steel, cemented carbide, ceramics, and the like that are hard and have high durability are used.

[0071] Part (a) of FIG. 7 is a cross-sectional view of the mold with the slide core 65, and part (b) of FIG. 7 is a cross-sectional view of the mold without a slide core.(Structure of Slide Core 65)

[0072] In the liquid cosmetic feeder 4 of the present embodiment, as illustrated in part (c) of FIG. 6, the liquid cosmetic feeder 4 can be manufactured even if the mold is combined with the slide core 65. The structure of the slide core 65 can be fabricated by laminating a first plate-shaped member 651 having a plate thickness of 0.1 mm and a second plate-shaped member 652 having a plate thickness of 0.2 mm. For the method of coupling the first plate-shaped member 651 and the second plate-shaped member 652, there are various methods, but for example, the following methods can be used.

[0073] Method of using an adhesive: It is a method of adhering metal plates using an adhesive for metal. Depending on the type of adhesive, it is possible to adhere with high strength and excellent durability.

[0074] Method of using welding: It is a method of welding metal plates. There are types of welding, such as arc welding, gas welding, and laser welding, and laser welding may be optimal for ultra-thin metal sheets.

[0075] Plate-shaped parts having a thickness of 0.1 mm and a thickness of 0.2 mm are incorporated into the slide core 65. This forms a comb-shaped core in the slide core 65.(Release from Mold 65 with Slide Core)

[0076] In the release method from the mold 62 after injection, as illustrated in part (b) of FIG. 6, the upper and lower slide cores 65 are released from constraint of an angular pin 624 and move up and down. At this point, the liquid cosmetic feeder 4, which is the injection molded product, is held in the mold rib 623 and does not adhere to and follow the upper and lower slide cores 65. Thereafter, the injection molded liquid cosmetic feeder 4 is pushed out by the operation of the ejector pin 67 and completely released from the mold.

[0077] In the slide core 65 of the mold 62, the first plate-shaped member 651 and the second plate-shaped member 652 are alternately fixed in parallel. In the present embodiment, the first plate-shaped member 651 having a thickness of 0.1 mm and the second plate-shaped member 652 having a thickness of 0.2 mm are alternately incorporated into the slide core 65 of the mold 62. By opening the slide core 65 up and down, the molded product is ejected from the mold 62.

[0078] In the present embodiment, the left-right opening of the mold 62 and the up-down opening of the slide core 65 operate simultaneously. However, the mold 62 may be opened left and right first, and then the slide core 65 may be opened up and down in sequence. Also, in the present embodiment, the liquid cosmetic feeder 4 is injection-molded with the axis orientation set in the vertical direction (z-axis direction) with respect to the plane of the drawings as illustrated in part (b) of FIG. 6, but may be injection-molded with the axis orientation set in the horizontal direction (x-axis direction) as illustrated in part (c) of FIG. 6.(Release from Mold without Slide Core)

[0079] The mold 62 with the slide core is complex in structure and does not necessarily need to be provided with the slide core 65 in the mold 62 of the present invention. The use of the following mold 62 is also within the scope of the present invention.

[0080] In other words, by forming the first plate-shaped member 651 and the second plate-shaped member 652 in the horizontal direction of the mold 62, it is possible to injection-mold without requiring the slide core 65 (part (b) of FIG. 7).

[0081] In the release method from the mold 62 after injection, as illustrated in part (b) of FIG. 7, the left and right molds 62 are first opened left and right by a mold opening and closing device (not illustrated). At this point, the liquid cosmetic feeder 4 is released from the right mold 62. Then, the liquid cosmetic feeder 4, which is the injection molded product, is held in the mold rib 623 and then pushed out by the operation of the ejector pin 67 and is completely released from the mold.(Mold Rib 623)

[0082] In the present embodiment, the mold ribs 623 are formed near the center of the left and right molds 62, respectively (part (d) of FIG. 6). When the slide core 65 of the present embodiment is opened up and down, the molded product is caught in the mold rib 623. Therefore, the molded product can be easily released from the slide core 65. The shape of the mold rib 623 is not particularly limited as long as the molded product can be easily released from the slide core 65. For example, the shape may be a shape that can fit into a recess somewhere in the molded product. The mold ribs 623 may also be formed in one of the left and right molds 62. The present inventors have succeeded in easily releasing the molded product from the mold 62 by providing such a convex shape in the mold 62.

[0083] Then, by pushing up the molded product with the ejector pin 67, the molded product can be completely ejected from the mold 62.

[0084] When the slide core 65 is opened up and down, the plate parts of the mold 62 and the molded product are closely connected, so that the molded product remains in one slide core 65, and the molded product cannot be released from the mold 62.

[0085] To prevent this, it is necessary to leave the liquid cosmetic feeder 4 on the mold 62 to eject the liquid cosmetic feeder 4 from the mold 62. Therefore, in the present embodiment, release ribs are formed in the mold 62 (part (c) of FIG. 6). In the present embodiment, the mold ribs 623 are formed in centers on both sides of the mold 62, but if there is a release rib that can temporarily hold the liquid cosmetic feeder 4 in the mold 62, the formation position of the mold rib 623 may be shifted from the centers. The release ribs may be formed in one of the male and female types.

[0086] As long as the shape and the like that enable the liquid cosmetic feeder 4 to be temporarily held in the mold 62, the release ribs can be used in the present invention without limiting the shape, number, and length thereof.

[0087] In an injection molding method, it has been stated that it is impossible to create a shape such as the liquid cosmetic feeder 4 with a 0.1 mm groove communicating through.

[0088] Since the extrusion mold extrudes from the relatively large mold 62 and extends the workpiece to build a thin shape, extrusion molding makes possible to create a groove shape of 0.1 mm.

[0089] Due to such a manufacturing method, great variation in the dimension occurs in the extrusion molding in the related art. In particular, variation in the outer diameter becomes large (variation of about ± 0.1 mm). It is completely inconceivable in this industry to make the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 with a groove of 0.1 mm communicating through with the injection molding method.

[0090] This time, to form a groove of 0.1 mm, the structure in the mold 62 was successfully expressed by lamination of thin plates such as 0.1 mm, 0.2 mm, and the like, and the liquid cosmetic feeder 4 of 1 was successfully manufactured by injection molding.(Cosmetic Applicator)

[0091] The liquid cosmetic feeder 4 of the present embodiment can be mounted on various liquid cosmetic applicators 1. Hereinafter, each part of the liquid cosmetic applicator 1 to which the liquid cosmetic feeder 4 of the present embodiment is mounted will be described. The following example describes an eyeliner as an example of the liquid cosmetic applicator 1.

[0092] The liquid cosmetic feeder 4 of the present invention is a core provided for "relaying" the liquid cosmetic P to the application portion 2. The liquid cosmetic feeder 4 can be applied to any liquid cosmetic applicator 1 as long as the liquid cosmetic feeder 4 is rod-shaped, the rear end portion is immersed in the liquid cosmetic P, and the front end portion can be connected to the application portion 2. In particular, the liquid cosmetic feeder 4 of the present embodiment can be mounted on an eyeliner, an eyebrow, a shadow liner, a concealer, and the like.(Application Portion)

[0093] The application portion 2 is, for example, a brush, and is a fibrous aggregate consisting of a synthetic resin such as nylon or PBT (polybutylene terephthalate). The application portion 2 is not limited to a brush, but may be, for example, of a sintered pen type or formed of porous urethane. When the liquid cosmetic P contains a solid, the application portion 2 is preferably a brush. In particular, when the liquid cosmetic P contains a solid, the application portion 2 is preferably made of a bundle of synthetic fibers such as nylon having flexibility, elasticity, and flexibility.

[0094] As illustrated in FIG. 1, the application portion 2 has a round rod shape extending in the axial direction (longitudinal direction) centered on the axis O. The application portion 2 has a conical shape in which the outer diameter gradually decreases from a mid-position in the axial direction toward the front end side. As illustrated in FIG. 2, the end surface of the rear end side of the application portion 2 is formed with the hole 2a recessed toward the front end side. The hole 2a has a tapered shape in which the inner diameter gradually decreases from the rear end side to the front end side. The inner diameter of the hole 2a may be equivalent to the outer diameter of the liquid cosmetic feeder 4 described later, but the inner diameter of the hole 2a may be slightly larger than the outer diameter of the liquid cosmetic feeder 4. As a result, a space (clearance) in which the liquid cosmetic P can flow may be formed between the outer peripheral surface of the liquid cosmetic feeder 4 and the inner peripheral surface of the hole 2a.

[0095] Also, the end of the rear end side of the application portion 2 is provided with a fastening layer 20 that bundles each fiber of the application portion 2. The above-described hole 2a penetrates the fastening layer 20. The fastening layer 20 is formed by, for example, adhering the fibers of the application portion 2 to each other by an adhesive material or the like. The fastening layer 20 has a disk shape centered on the axis O. The outer diameter of the fastening layer 20 is slightly larger than the outer diameter of the application portion 2, so that the fastening layer 20 protrudes in a flange shape from the application portion 2 to the outer peripheral side.(Liquid Cosmetic Tank 3)

[0096] Referring back to FIG. 1, the liquid cosmetic tank 3 is provided extending from the end of the rear end side of the liquid cosmetic feeder 4 to the rear end side.

[0097] The liquid cosmetic tank 3 includes an outer cylindrical portion 30 that extends in the axial direction and a tail plug 39 that blocks the rear end side of the outer cylindrical portion 30. The space surrounded by the outer cylindrical portion 30, the tail plug 39, and the pressure fluctuation buffer member 5 described later is the liquid cosmetic storage space 30a that accommodates the paint. The liquid cosmetic storage space 30a accommodates liquid paint and liquid paint containing a solid as the liquid cosmetic P. The liquid paint is a liquid cosmetic used for the eyeliner, for example.

[0098] Solids have a higher specific gravity than liquid paints, such as metal powders such as titanium and aluminum, laminates made of thin films such as gold, silver, aluminum, tin, and the like by evaporation deposition, and inorganic substances such as glass beads. The viscosity of the liquid cosmetic P containing the solid is preferably about 30 mPa·s or less.

[0099] A stirring member M is accommodated in the liquid cosmetic storage space 30a in the liquid cosmetic tank 3. By shaking the entire liquid cosmetic applicator 1 in the axial direction, the liquid cosmetic P in the liquid cosmetic tank 3 can be stirred by the stirring member M. Furthermore, the shape of the stirring member M is not limited and may be, for example, spherical, cylindrical, polyhedral, cubic, or a rectangular, and any other polyhedral shape. Depending on the type of the liquid cosmetic P, the stirring member M may not necessarily be provided.(Outer Cylindrical Portion)

[0100] The outer cylindrical portion 30 includes the liquid cosmetic storage space 30a and a feeder storage area 30b extending further to the front end side from the liquid cosmetic storage space 30a. The feeder storage area 30b is disposed outside the feeder in the radial direction of the liquid cosmetic feeder 4, is provided at a position that overlaps the liquid cosmetic feeder 4 from the viewpoint of the feeder radial direction, and covers the liquid cosmetic feeder 4. The feeder storage area 30b has a tapered shape in which the outer diameter gradually decreases from a mid-position in the axial direction toward the front end side. As illustrated in FIG. 2, the end on the front end side of the feeder storage area 30b is disposed outside the feeder in the radial direction with respect to the application portion 2, is provided in a position that overlaps the application portion 2 from the viewpoint of the feeder radial direction, and covers the application portion 2.

[0101] Furthermore, in the inner surface of the front end side of the outer cylindrical portion 30, an outer cylinder first step surface 31 that faces the rear end side in the axial direction and forms an annular shape centered on the axis O and an outer cylinder second step surface 32 that is arranged on the rear end side of the outer cylinder first step surface 31 and forms an annular shape centered on the axis O are formed at intervals in the axial direction. As a result, the feeder storage area 30b in the outer cylindrical portion 30 is formed with an outer cylinder first recess 33 and an outer cylinder second recess 34 that are annularly recessed about the axis O from the inner peripheral surface of the outer cylindrical portion 30 to the outer side of the feeder in the radial direction. Accordingly, the inner diameter of the outer cylindrical portion 30 gradually decreases toward the front end side. In the outer cylindrical portion 30, an air flow groove 30x that communicates with the outer cylinder first recess 33, extends in the axial direction, and opens to the end surface of the front end side of the outer cylindrical portion 30 is formed in a portion of the feeder in the circumferential direction. The air is exchanged in and out of a buffer space K described later via the air flow groove 30x, the outer cylinder first recess 33, and the outer cylinder second recess 34. The feeder storage area 30b in the outer cylindrical portion 30 is provided with an outer cylinder flange 35 that protrudes annularly outside of the feeder in the radial direction at a position in the middle of the axial direction that is the rear end side of the outer cylinder second step surface 32 (see FIG. 2).(Inner Cylindrical Portion)

[0102] Furthermore, an inner cylindrical portion 36 is provided between the outer cylindrical portion 30 and the application portion 2. The inner cylindrical portion 36 extends in the axial direction and engages the fastening layer 20 and the outer cylindrical portion 30. The inner cylindrical portion 36 is covered by pressing the end of the rear end side of the application portion 2 from the outside of the feeder in the radial direction. Specifically, the outer peripheral surface of the inner cylindrical portion 36 is formed with an inner cylinder outer step surface 36a that faces the front end side in the axial direction and is annular about the axis O. Due to the inner cylinder outer step surface 36a, the outer peripheral surface of the inner cylindrical portion 36 is formed with an outer protrusion 37 that protrudes outside of the feeder in the radial direction and is annular about the axis O. Accordingly, the outer diameter of the inner cylindrical portion 36 is larger at the rear end side compared to the front end side.

[0103] The outer protrusion 37 of the inner cylindrical portion 36 is disposed in the outer cylinder first recess 33 of the outer cylindrical portion 30, and the inner cylindrical portion 36 is disposed so that the inner cylinder outer step surface 36a of the inner cylindrical portion 36 faces the outer cylinder first step surface 31 of the outer cylindrical portion 30 in the axial direction. Accordingly, the inner cylinder outer step surface 36a of the inner cylindrical portion 36 and the outer cylinder first step surface 31 of the outer cylindrical portion 30 are engaged, and the inner cylindrical portion 36 is engaged to the outer cylindrical portion 30. Furthermore, the inner peripheral surface of the inner cylindrical portion 36 is formed with an inner cylinder inner step surface 36b that is disposed on the rear end side of the inner cylinder outer step surface 36a, faces the rear end side, and is annular about the axis O. Due to the inner cylinder inner step surface 36b, the inner peripheral surface of the inner cylindrical portion 36 is formed with an inner recess 38 that is concave outside the feeder in the radial direction and is annular about the axis O. The fastening layer 20 is disposed in the inner recess 38 to engage the inner cylindrical portion 36 and the fastening layer 20, and the outer cylindrical portion 30 supports the application portion 2 via the inner cylindrical portion 36.(Outer Case)

[0104] An outer case 6 abuts from the rear end side to the outer cylindrical flange 35 of the outer cylindrical portion 30 in the axial direction, and covers the outer cylindrical portion 30 from the outside of the feeder radial direction in the rear end side of the outer cylindrical flange 35. In other words, the outer case 6 has a bottomed cylindrical shape that extends in the axial direction about the axis O so that the outer cylindrical portion 30 can be inserted. The outer cylindrical portion 30 is fitted to the outer case 6, and the outer case 6 and the outer cylindrical portion 30 are fixed. Inside the outer case 6, a rear end space S2 is formed in a region sandwiched between a bottom surface of the outer case 6 and the tail plug 39 in the liquid cosmetic tank 3 (see FIG. 1).(Pressure Fluctuation Buffer Member 5)

[0105] As illustrated in FIG. 5, the pressure fluctuation buffer member 5 includes a feeder holding cylinder 50 and a buffer mechanism 51 that forms the buffer space K between the feeder holding cylinder 50 and the inner peripheral surface of the outer cylindrical portion 30 outside in the feeder radial direction of the feeder holding cylinder 50. The pressure fluctuation buffer member 5 is formed of a synthetic resin. When the liquid cosmetic P in the liquid cosmetic tank 3 is an aqueous paint, the synthetic resin can be an ABS resin, an AS resin, a PET resin, a PBT resin, a styrene resin, a POM resin, polycarbonate, polyamide, modified polyphenylene ether, and the like. If the liquid cosmetic P in the liquid cosmetic tank 3 is an oil-based paint (especially paint with alcohol as a main solvent), a PE resin, a PP resin, a POM resin, a PET resin, a PBT resin, polyamide, and the like can be used as the synthetic resin.(Feeder Holding Cylinder)

[0106] The feeder holding cylinder 50 extends in the axial direction. The feeder holding cylinder 50 includes a main body cylindrical portion 52 through which the liquid cosmetic feeder 4 is inserted in a cylindrical shape centered on the axis O, and an extension 53 integrally provided with the main body cylindrical portion 52 at the rear end side of the main body cylinder portion 52.

[0107] Since the liquid cosmetic feeder 4 is fitted to the main body cylindrical portion 52, the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 faces the feeder in the radial direction on the inner peripheral surface of the main body cylindrical portion 52. The liquid cosmetic feeder outer peripheral surface 43 of the liquid cosmetic feeder 4 (see FIG. 3) contacts the inner peripheral surface of the main body cylindrical portion 52. A dimension W2 between grooves in the feeder horizontal direction of the liquid cosmetic feeder outer peripheral surface 43 (see FIG. 3) is very small, and since the liquid cosmetic feeder 4 is fitted to the main body cylindrical portion 52, a very small gap (not illustrated) is formed between the main body cylindrical portion 52 and the liquid cosmetic feeder 4. Due to this small gap, a space in which the liquid cosmetic flow grooves 40 adjacent in the horizontal direction communicate exists between the main body cylindrical portion 52 and the liquid cosmetic feeder 4.(Connecting Flow Path)

[0108] Furthermore, a connecting flow path F communicating with the liquid cosmetic flow groove 40 is formed in the main body cylindrical portion 52 in the pressure fluctuation buffer member 5. Although the liquid cosmetic flow groove 40 is formed so that the liquid cosmetic P is more present between the pressure fluctuation buffer member 5 and the liquid cosmetic feeder 4, entry of the liquid cosmetic P into the buffer space K can be improved by the connecting flow path F to avoid leakage of the liquid cosmetic P. By providing the connecting flow path F, air is moved between the buffer space K and the liquid cosmetic storage space 30a, and the liquid cosmetic P is moved between the buffer space K and the liquid cosmetic flow groove 40 by the connecting flow path F, thereby effectively reducing leakage of the liquid cosmetic P.

[0109] Note that in the above embodiment, a transverse groove (not illustrated) connecting the liquid cosmetic flow grooves 40 adjacent in the feeder peripheral direction may be further provided on the outer peripheral surface of the liquid cosmetic feeder 4. That is, such a transverse groove extends in the feeder circumferential direction across the liquid cosmetic flow groove 40. Such a transverse groove makes it possible to transfer the liquid cosmetic P between the liquid cosmetic flow grooves 40, and furthermore, it is possible to smoothly flow the liquid cosmetic P toward the front end side.

[0110] Although the eyeliner is described above as an example of the liquid cosmetic applicator 1, sufficient functions can be performed even if the liquid cosmetic feeder 4 is mounted on the liquid cosmetic applicator 1 other than the eyeliner, for example, the liquid cosmetic applicator 1 such as an eyebrow, a shadow liner, and a concealer.(Buffer Mechanism)

[0111] A buffer mechanism 51 is integrally formed with the feeder holding cylinder 50. The buffer mechanism 51 includes a partition member 56 that protrudes annularly from the main body cylindrical portion 52 to the outside of the feeder radial direction and is centered on the axis O at a mid-position in the axial direction of the main body cylindrical portion 52, a first convex member 57 formed on the outer peripheral surface of the main body cylindrical portion 52 at the rear end side of the partition member 56, and a second convex member 58 formed on the outer peripheral surface of the main body cylindrical portion 52 at the front end side of the partition member 56.

[0112] Hereinafter, examples will be specifically described to enhance the understanding of the present invention. However, the scope of the present invention is not limited to the following examples.(Example 1)

[0113] The liquid cosmetic feeder 4 was manufactured by injection molding, and an eyeliner was manufactured using the same. In the present example 1, cutting processing such as front end processing and rear end processing, which is a post-process, was not performed.

[0114] The mold 62 molding the liquid cosmetic feeder 4 was fabricated by laminating thin plates with plate thicknesses of 0.1 mm and 0.2 mm to manufacture the mold 62 of the liquid cosmetic feeder 4 (part (c) of FIG. 6).

[0115] A comb shape corresponding to the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 with the groove width dimension W1 of 0.1 mm is formed in the mold 62. Then, the injection molding machine 60 (FIG. 6) with the mold 62 attached succeeded in manufacturing the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 by the injection molding method.

[0116] The liquid cosmetic feeder 4 manufactured by the injection molding method was incorporated into the feeder holding cylinder 50 to manufacture the liquid cosmetic applicator 1 (eyeliner) (FIG. 4).

[0117] In FIG. 4, the liquid cosmetic feeder 4 was press-fitted into the feeder holding cylinder 50.

[0118] In the present example, the variation in the outer diameter dimension D of the liquid cosmetic applicator 1 was reduced within ± 0.02 mm by the injection molding method, and an assembly defect rate was reduced.

[0119] The assembly defect rate of the liquid cosmetic applicator 1 by the injection molding method was 0 out of 100 (0% defect rate). From the viewpoint that the defect rate was 35% in the case of Comparative Example 1 below, it was confirmed that according to the injection molding method and the liquid cosmetic feeder 4 of the present invention, it is possible to manufacture a stabilized liquid cosmetic feeder 4 with excellent dimensions.(Example 2)

[0120] As Example 2, the eyeliner illustrated in FIG. 5 was manufactured.

[0121] The difference from Example 1 is that the liquid cosmetic feeder 4 was fixed to the main body cylindrical portion 52 by providing a step to prevent the liquid cosmetic feeder 4 from coming off (not press-fitted). As a result, the results were different from those of the eyeliner of Example 1 in terms of matching with formulation, prevention of cracking of the front end of the brush, an assembly method, and the like.

[0122] Performance of the liquid cosmetic applicator 1 of Example 1 incorporating the liquid cosmetic feeder 4 manufactured by the injection molding was then checked.(Comparative Example 1)

[0123] When the molding method was used as the extrusion molding with the same condition in Example 1, assembly defects in the outer capillary tube bodies of Example 1 occurred in 17 out of 48 units (35% defect rate).(Performance Test 1 Performance Test of Liquid Cosmetic with Dye)•Formulation: Dye (Containing Brightness Agent)

[0124] Brown (Containing Brightness Agent) Purple (Containing Brightness Agent) Pink (Containing Brightness Agent) ▪ Injection-molded outer capillary tube body (outer diameter φ1.8 groove width 0.1 mm number of grooves 8)1. Writing Test

[0125] (Test method) Using one liquid cosmetic applicator 1, 200 lines of approximately 4 cm length were written on a piece of high-quality paper, and handwriting was visually checked for smudges.(Number of Tests) n = 1(Test Results)

[0126] In the case of brown (containing brightness agent), the handwriting was good with no smudges. In the case of purple (containing brightness agent), the handwriting was good with no smudges. In the case of pink (containing brightness agent), the handwriting was good with no smudges. In the case of any dye formulation, a sufficient function as the liquid cosmetic applicator 1 was exhibited, resulting in a good result for actual use.2. Time-Lapse Test

[0127] (Test Method) The pens were placed with the front end facing upward, sideways, and downward in a thermostatic chamber at 40°C or higher for one month, and then ten lines of about 4 cm length were written on high-quality paper to check for smudges of the handwriting.(Number of Tests) Upward, Sideways, and Downward n = 3 each

[0128] (Test Results) In all orientations of upward, sideways, and downward, brown (containing brightness agent) produced good handwriting with no smudges. Purple (containing brightness agent) produced good handwriting with no smudges. Pink (containing brightness agent) produced good handwriting with no smudges.

[0129] Even in the above time-lapse test, no smudges occurred in all formulations. Handwriting was good. It can be said that a sufficient function as the liquid cosmetic applicator 1 was exhibited. The results were good for actual use.3. Forced Pump Test

[0130] (Test Method) The applicator is left facing downward in a thermostatic chamber at 40°C or higher for 24 hours.

[0131] After 24 hours, after immediately removing from the thermostatic chamber and facing downward, the cap fitting was repeated 100 times.(Number of Tests) n = 3(Test Results)

[0132] Brown (containing brightness agent)No leakage even after 100 timesPurple (containing brightness agent)No leakage even after 100 timesPink (containing brightness agent)No leakage even after 100 times

[0133] All exhibited a sufficient function as the liquid cosmetic applicator 1. The results were good for actual use.4. Half-Cap Leakage Test(Test Method)

[0134] The cap was opened halfway and placed in a thermostatic chamber at 40°C or higher with the cap facing downward, and left for 24 hours. After that, the applicator was removed from the thermostatic chamber and check for leakage.(Number of Tests) n = 3(Test Results)

[0135] Brown (containing brightness agent)No leakagePurple (containing brightness agent)No leakagePink (containing brightness agent)No leakage

[0136] All exhibited a sufficient function as the liquid cosmetic applicator 1. The results were good for actual use.5. Decompression Test

[0137] (Formulation)Containing pink brightness agent (Test Method)

[0138] The cap was removed, the front end of the pen was pointed downward, and the pressure was lowered from 1 atm. The lowered state was observed for 1 minute to check for leakage. (Test Method)n = 3(Test Results)No leakage was observed.

[0139] A sufficient function was exhibited as the liquid cosmetic applicator 1. The results were good for actual use.(Performance Test 2 Performance Test of Liquid Cosmetic P with Pigment)

[0140] The number of grooves was increased to 10, and a writing test of the liquid cosmetic was performed using the liquid cosmetic P as a pigment.•Formulation: Pigment (No brightness agent)

[0141] Black Brown Brown Black Green ▪ Injection-molded outer capillary tube body (outer diameter φ1.8 groove width 0.1 mm number of grooves 10)Writing Test(Test Method)

[0142] Using one liquid cosmetic applicator 1, 200 lines of approximately 4 cm length were written on a piece of high-quality paper, and handwriting was visually checked for smudges. (Number of Tests)n = 1(Test Results)BlackGood handwriting with no smudgesBrownGood handwriting with no smudgesBrown BlackGood handwriting with no smudgesGreenGood handwriting with no smudges

[0143] All exhibited a sufficient function as the liquid cosmetic applicator 1. The results were good for actual use.

[0144] Finally, the writing test results for formulations containing high-brightness agents in the pigment formulation are reported.(Performance Test 3 Test with Pigment Containing High-Brightness Agent)•Formulation: Pigment (Containing High-Brightness Agent)

[0145] Red (Containing High-Brightness Agent) Blue (Containing High-Brightness Agent) Lavender (Containing High-Brightness Agent) Green (Containing High-Brightness Agent) Navy (Containing High-Brightness Agent) Pink (Containing High-Brightness Agent) Brown (Containing High-Brightness Agent) Brown (Containing Brightness Agent) ▪ Injection-molded outer capillary tube body (outer diameter φ1.9 groove width 0.13 mm number of grooves 12, two of which serve as both the groove for the mold rib receiving portion and the liquid cosmetic flow groove)1. Writing Test(Test Method)

[0146] Using one liquid cosmetic applicator 1, 200 lines of approximately 4 cm length were written on a piece of high-quality paper, and handwriting was visually checked for smudges.(Test Results)

[0147] Red (Containing High-Brightness Agent) Good handwriting with no smudges Blue (Containing High-Brightness Agent) Good handwriting with no smudges Lavender (Containing High-Brightness Agent) Good handwriting with no smudges Green (Containing High-Brightness Agent) Good handwriting with no smudges Navy (Containing High-Brightness Agent) Good handwriting with no smudges Pink (Containing High-Brightness Agent) Good handwriting with no smudges Brown (Containing Brightness Agent) Good handwriting with no smudges Brown (Containing Brightness Agent) Good handwriting with no smudges

[0148] All formulations produced good results with good handwriting and no smudges. A sufficient function was exhibited as a liquid cosmetic applicator such as an eyeliner, an eyebrow, a shadow liner (a cosmetic applicator for applying makeup to the tear trough on the face), and a concealer. The results were good for actual use.INDUSTRIAL APPLICABILITY

[0149] The liquid cosmetic feeder 4 of the present invention can smoothly guide and discharge the liquid cosmetic P.REFERENCE SIGNS LIST

[0150] 1: liquid cosmetic applicator 1 2: application member 2a: hole 3: liquid cosmetic tank 4: liquid cosmetic feeder 5: pressure fluctuation buffer member 6: outer case 20: fastening layer 30: outer cylindrical portion 30a: liquid cosmetic storage space 30b: feeder storage area 30x: air flow groove 31: outer cylinder first stage difference surface 32: outer cylinder second stage difference surface 33: outer cylinder first recess 34: outer cylinder second recess 35: outer cylinder flange 36: inner cylindrical portion 36a: inner cylinder outer step surface 36b: inner cylinder inner step surface 37: outer protrusion 38: inner recess 39: tail plug 40: liquid cosmetic flow groove 42: mold rib receiving portion 43: liquid cosmetic feeder outer peripheral surface 44: step portion 50: feeder holding cylinder 51: buffer mechanism 52: main body cylindrical portion 53: extension 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: driving device 65: slide core 651: first plate-shaped part 652: second plate-shaped part 66: heater 67: ejector pin 68: nozzle D: outer diameter dimension F: connecting flow path K. buffer space L1: depth dimension of liquid cosmetic flow groove 40 M: stirring member O: axis P: liquid cosmetic S1: front end space S2: rear end space W1: groove width dimension W2: dimension between grooves

Examples

example 1

(Example 1)

[0113]The liquid cosmetic feeder 4 was manufactured by injection molding, and an eyeliner was manufactured using the same. In the present example 1, cutting processing such as front end processing and rear end processing, which is a post-process, was not performed.

[0114]The mold 62 molding the liquid cosmetic feeder 4 was fabricated by laminating thin plates with plate thicknesses of 0.1 mm and 0.2 mm to manufacture the mold 62 of the liquid cosmetic feeder 4 (part (c) of FIG. 6).

[0115]A comb shape corresponding to the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 with the groove width dimension W1 of 0.1 mm is formed in the mold 62. Then, the injection molding machine 60 (FIG. 6) with the mold 62 attached succeeded in manufacturing the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 by the injection molding method.

[0116]The liquid cosmetic feeder 4 manufactured by the injection molding method was incorporated into the feeder holding cylinder...

example 2

(Example 2)

[0120]As Example 2, the eyeliner illustrated in FIG. 5 was manufactured.

[0121]The difference from Example 1 is that the liquid cosmetic feeder 4 was fixed to the main body cylindrical portion 52 by providing a step to prevent the liquid cosmetic feeder 4 from coming off (not press-fitted). As a result, the results were different from those of the eyeliner of Example 1 in terms of matching with formulation, prevention of cracking of the front end of the brush, an assembly method, and the like.

[0122]Performance of the liquid cosmetic applicator 1 of Example 1 incorporating the liquid cosmetic feeder 4 manufactured by the injection molding was then checked.

TECHNICAL FIELD

[0001] The present invention relates to a liquid cosmetic applicator 1 such as an eyeliner, an eyebrow, a shadow liner, and a concealer. In particular, the present invention relates to an injection molding method of a liquid cosmetic feeder mounted on the liquid cosmetic applicator 1, and the liquid cosmetic feeder and the liquid cosmetic applicator 1.BACKGROUND ART

[0002] An eyeliner, an eyebrow, a shadow liner, a concealer, and the like are known as the liquid cosmetic applicator 1. For example, in a liquid cosmetic container described in Patent Literature 1, a liquid paint is guided to a brush portion through a relay core.

[0003] In a liquid cosmetic applicator described in Patent Literature 2, it is described "a material of a member constituting a housing portion can be, for example, a cylindrical member formed by extrusion molding or injection molding out of a synthetic resin material such as polypropylene, polyethylene, polybutylene terephthalate, polyethylene terephthalate, or the like, considering permeability of gas and liquid tightness of a connecting portion".

[0004] In a liquid applicator described in Patent Literature 3, a liquid retention member or a relay core of the liquid applicator is formed by extrusion molding.CITATION LISTPATENT LITERATURE

[0005] Patent Literature 1: JPS59-125314U Patent Literature 2: JP2019-193698A Patent Literature 3: JP2015-024584A SUMMARY OF INVENTIONTECHNICAL PROBLEM

[0006] Extrusion molding is a method in which a material inserted from an inlet is heated in a heating cylinder and passed through an extrusion port of a mold to form a certain shape. Since the material is cooled and cured after being extruded, a molded product has the same cross-sectional shape regardless of where the molded product is cut.

[0007] In extrusion molding, a synthetic resin pellet is pushed into an extrusion mold while being heated and dissolved using a heater, and then molded and dissolved plastic is cooled and solidified. Since the dissolved plastic constantly comes out of the extrusion mold, it is not possible to ensure sufficient cooling time with the extrusion mold alone, so the dissolved plastic is supported by a sizing die to prevent deformation while passing through a cooling device. After leaving the sizing die, the material passes through a cooling water tank and is pulled by a pick-up machine while being cut into a required size.

[0008] An extrusion molding process is sequentially as follows in steps 1 to 5.

[0009] 1. Extrusion, 2. Mold, 3. Sizing die (water tank), 4. Pick-up machine, 5. Cutting machine.

[0010] In the case of a liquid cosmetic feeder 4 of the liquid cosmetic applicator 1, the steps 1 to 5 above are followed by post-processes of steps 6 and 7 described below.

[0011] 6. Cutting processing process, 7. Full-length cutting in some cases.

[0012] In other words, in the case of the liquid cosmetic feeder 4 by extrusion molding, a cutting processing process such as front end processing and rear end processing is required. Front end processing and rear end processing are used to form a front end shape and a rear end shape of the liquid cosmetic feeder 4 by performing cutting processing on a front end and a rear end of the liquid cosmetic feeder 4. Then, in the extrusion molding, a full-length cutting process that cuts a full-length is necessary in some cases.

[0013] Burr easily occurs in the cutting processing such as the front end processing, the rear end processing, and the like. If there are many burrs, a liquid cosmetic flow groove 40 will be blocked, and a liquid cosmetic discharge will be poor. Therefore, it is necessary to add a deburring process in some cases. Due to the addition of manufacturing processes such as the front end processing, the rear end processing, and the like as a post-process, it is also disadvantageous in terms of delivery time and cost.

[0014] In the case of the liquid cosmetic feeder 4 formed by extrusion molding, since the workpiece is extended after extrusion, a variation in dimension of the liquid cosmetic feeder 4, especially an outer diameter, becomes large (variation of about ± 0.1 mm).

[0015] Therefore, when assembling the liquid cosmetic applicator 1, some parts have a large outer diameter and cannot be inserted into a mating part, while others have a small outer diameter and are easily pulled out of the mating part, leading to assembly defects.(Dimension Stabilization)

[0016] In extrusion molding, a variation of an outer diameter dimension D of the liquid cosmetic feeder 4 is ± 0.1 mm, which is very large. Therefore, when assembling the liquid cosmetic applicator 1, some parts have a large outer diameter and cannot be inserted into the mating part, while others have a small outer diameter and are easily pulled out of the mating part. An object of the present invention is to reduce the variation of the outer diameter dimension D of the liquid cosmetic feeder 4 and stabilize the dimension.(Process Simplification)

[0017] Another object of the present invention is to enable stable molding of shape without front end processing, rear end processing, and the like.

[0018] Another object of the present invention is to manufacture the liquid cosmetic feeder 4 in a low cost and a short time without front end processing, rear end processing, and the like.(No Deburring Process Required)

[0019] In the extrusion molding method in the related art, burr occurs during front end processing, rear end processing, and the like as a post-process. Since burrs hinder a flow of liquid cosmetics, this deburring process is absolutely necessary. A further object of the present invention is to manufacture the liquid cosmetic feeder 4 that does not require this deburring process.

[0020] Therefore, an object of the present invention is to provide the liquid cosmetic feeder 4 with no variation in dimension, especially the outer diameter, of the liquid cosmetic feeder 4 by an injection molding method without depending on extrusion molding. An object is to form the liquid cosmetic feeder 4 by an injection molding method. Then, a method of manufacturing the liquid cosmetic feeder 4, and the liquid cosmetic applicator 1 such as an eyeliner, an eyebrow, a shadow liner, and a concealer that is provided with the liquid cosmetic feeder 4 and can smoothly guide and discharge paint are provided.SOLUTION TO PROBLEM

[0021] (1) A liquid cosmetic feeder according to an aspect of the present invention to achieve the above objects is a liquid cosmetic feeder used for a liquid cosmetic applicator, in which the liquid cosmetic feeder is a liquid cosmetic feeder that is injection-molded out of a synthetic resin, and the liquid cosmetic feeder is formed with an ultrafine liquid cosmetic flow groove. (2) In the liquid cosmetic feeder, the liquid cosmetic feeder may be further formed with a mold rib receiving portion. (3) In the liquid cosmetic feeder, a cross-sectional shape of the liquid cosmetic flow groove may be a comb shape. (4) In the liquid cosmetic feeder, a groove width dimension W1 of the liquid cosmetic flow groove may be 0.05 mm or more and 0.2 mm or less. (5) A method of manufacturing a liquid cosmetic feeder according to an aspect of the present invention is a method of manufacturing a liquid cosmetic feeder, in which an ultrafine liquid cosmetic flow groove for flowing a liquid cosmetic is formed on an outer periphery, by an injection molding method in which a heat-melted synthetic resin material is injected into a mold and cooled to obtain a molded product. (6) The method of manufacturing the liquid cosmetic feeder may be a method of manufacturing the liquid cosmetic feeder that does not include a cutting processing process, which is a post-process. (7) The method of manufacturing the liquid cosmetic feeder may be a method of manufacturing the liquid cosmetic feeder that further includes a process of opening a slide core in a process of the injection molding method. (8) The method of manufacturing the liquid cosmetic feeder provides the method of manufacturing the liquid cosmetic feeder according to (5), in which the liquid cosmetic feeder is formed with a liquid cosmetic flow groove that fits on a plate-shaped member of the mold. (9) The method of manufacturing the liquid cosmetic feeder provides the method of manufacturing the liquid cosmetic feeder according to (7), in which the liquid cosmetic feeder is formed with a mold rib receiving portion 42 and a liquid cosmetic flow groove that fits on a plate-shaped member of the slide core. (10) The method of manufacturing the liquid cosmetic feeder may be the method of manufacturing the liquid cosmetic feeder according to (5), in which a cross-sectional shape of the liquid cosmetic flow groove is a comb shape. (11) The method of manufacturing the liquid cosmetic feeder may be the method of manufacturing the liquid cosmetic feeder according to (10), in which a groove width dimension W1 of the liquid cosmetic flow groove is 0.05 mm or more and 0.2 mm or less. (12) The liquid cosmetic feeder may be a liquid cosmetic feeder manufactured by the manufacturing method according to any of (5) to (11). (13) A liquid cosmetic applicator according to an aspect of the present invention may be a liquid cosmetic applicator including the liquid cosmetic feeder according to (13) described above. (14) The liquid cosmetic applicator may be an eyeliner. ADVANTAGEOUS EFFECTS OF INVENTION

[0022] The present invention provides the liquid cosmetic feeder 4 by the injection molding method without depending on extrusion molding.BRIEF DESCRIPTION OF DRAWINGS

[0023] [FIG. 1] FIG. 1 is a cross-sectional view of the liquid cosmetic applicator 1 including the liquid cosmetic feeder 4 according to an example of the present invention. [FIG. 2] FIG. 2 is an enlarged view of an A portion of FIG. 1. [FIG. 3] FIG. 3 is a diagram illustrating the liquid cosmetic feeder 4 (a front end with a tapered shape) of another example of the present invention. Part (a) is a side view, part (b) is a plan view, part (c) is a front view, part (d) is a rear view, part (e) is an A-A' cross-section, part (f) is a B-B' cross-section, and part (g) is a C-C' cross-section. [FIG. 4] FIG. 4 is a diagram illustrating the liquid cosmetic applicator 1 including the liquid cosmetic feeder 4 according to the example of FIG. 3. Part (a) is a side view, part (b) is a rear view, part (c) is an A-A' cross-section, and part (d) is an enlarged cross-section of a B portion. [FIG. 5] FIG. 5 is a diagram illustrating the liquid cosmetic feeder 4 according to yet another example of the present invention (having a step portion 44 formed at a front end) and the liquid cosmetic applicator 1 equipped with the same. Part (a) is a front view, part (b) is a side view, part (c) is a rear view, part (d) is a plan view, part (e) is a rear view, part (f) is an enlarged view of B, part (g) is a C-C cross-section, part (h) is an A-A cross-section, part (i) is a D-D cross-section, part (j) is an enlarged view of E, and part (k) is a partial cross-section. [FIG. 6] FIG. 6 is a schematic diagram illustrating the operation of an injection molding machine 60 used in manufacture of the liquid cosmetic feeder 4 according to an example of the present invention. Part (a) is a schematic diagram of the injection molding machine 60, part (b) is a schematic diagram of a release process (a direction of an axis O of the liquid cosmetic feeder 4 is oriented in a direction orthogonal to an x-axis and a y-axis), part (c) is a schematic diagram of the release process, which is another embodiment of the present invention (the direction of the axis O of the liquid cosmetic feeder 4 is oriented in the y-axis direction), part (d) is an enlarged view of an A portion, and part (e) is an enlarged view of a B portion. [FIG. 7] FIG. 7 is a cross-sectional view of a mold 62 corresponding to the liquid cosmetic feeder 4 of FIG. 3. Part (a) is a cross-sectional view of the mold 62 with a slide core 65, and part (b) is a cross-sectional view of the mold 62 without a slide core. [FIG. 8] FIG. 8 is a diagram illustrating a modification of the liquid cosmetic feeder 4 according to an example of the present invention. Parts (a) and (b) are diagrams of the liquid cosmetic feeder of the example of FIG. 1, parts (c) and (d) are diagrams of the liquid cosmetic feeder 4 of the example of FIG. 4, and parts (e) and (f) are diagrams of the liquid cosmetic feeder 4 of the example of FIG. 5. [FIG. 9] FIG. 9 is a cross-sectional view illustrating a modification of the liquid cosmetic feeder 4 according to the present invention. [FIG. 10] FIG. 10 is a cross-sectional view of the liquid cosmetic feeder 4 in the related art. DESCRIPTION OF EMBODIMENTS

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings using an eyeliner as an example of the liquid cosmetic applicator 1.(Overall Configuration of Liquid Cosmetic Applicator 1)

[0025] First, as illustrated in FIG. 1, the liquid cosmetic applicator 1 is rod-shaped and supplies a liquid cosmetic P from a rear end side to a front end side, and causes the liquid cosmetic P to be discharged from the front end side.

[0026] The liquid cosmetic applicator 1 includes an application portion 2 that discharges the liquid cosmetic P, a liquid cosmetic tank 3 that forms a liquid cosmetic storage space 30a that accommodates the liquid cosmetic P, the liquid cosmetic feeder 4 that supplies paint from the liquid cosmetic tank 3 to the application portion 2, a pressure fluctuation buffer member 5 that buffers pressure fluctuation in the liquid cosmetic storage space 30a, and an outer case 6 that is provided on an outer peripheral side of the pressure fluctuation buffer member 5.(Overall Shape of Liquid Cosmetic Feeder 4)

[0027] Next, the liquid cosmetic feeder 4 of the present embodiment will be described. The liquid cosmetic feeder 4 is used for a liquid cosmetic applicator. The liquid cosmetic feeder supplies the liquid cosmetic P to the application portion 2, that is, the liquid cosmetic feeder 4 is a core provided for "relaying" the liquid cosmetic P to the application portion 2. An example of the liquid cosmetic feeder 4 according to an embodiment of the present invention is illustrated in FIG. 3. As illustrated in FIG. 3, the liquid cosmetic feeder 4 has, for example, a round rod shape. A rear end portion of the liquid cosmetic feeder 4 is immersed in the liquid cosmetic P, and the liquid cosmetic P is sucked up to the front end side by capillary force of the liquid cosmetic feeder 4. A front end portion of the liquid cosmetic feeder 4 is covered with the application portion 2, and the liquid cosmetic P absorbed by the capillary force can be supplied to the application portion 2 from inside of a rear end portion of the application portion 2.

[0028] A shape of the liquid cosmetic feeder 4 may have a tapered shape at the front end as illustrated in part (c) of FIG. 8 or form a step shape at the front end as illustrated in part (e) of FIG. 8. The liquid cosmetic feeder may be cut off as illustrated in part (a) of FIG. 8 without forming a tapered portion or the step portion 44 at the front end or the rear end.

[0029] Hereinafter, in the present specification, a direction orthogonal to an axial direction, that is, a radial direction of the liquid cosmetic feeder 4 is a feeder radial direction. A circumferential direction of the liquid cosmetic feeder 4 is taken as a feeder circumferential direction. A vertical direction is, for example, an up-down direction (y-axis direction) of the drawings in FIGS. 3 and 5. A horizontal direction is, for example, a left-right direction (x-axis direction) of the drawings in FIGS. 3 and 5. A z-axis direction refers to an axis orthogonal to the x-axis and the y-axis in the orthogonal coordinate axis system, and the x-axis is the horizontal direction, the y-axis is the vertical direction, and the z-axis is a depth direction.(Arrangement of Liquid Cosmetic Feeder 4)

[0030] In the present embodiment, the liquid cosmetic feeder 4 is inserted into a hole 2a from the rear end side of the application portion 2, as illustrated in FIG. 1, and is provided in the liquid cosmetic applicator 1. In other words, the liquid cosmetic feeder 4 is inserted into the application portion 2 and used for the liquid cosmetic applicator 1. However, as long as the liquid cosmetic P can be flown to the application portion 2, the hole 2a is not necessarily required.

[0031] Further forward than an end surface of the front end side of the liquid cosmetic feeder 4, a conical-shaped front end space S1 is formed between the liquid cosmetic feeder 4 and an inner surface of the hole 2a. An end of the rear end side of the liquid cosmetic feeder 4 is disposed in the liquid cosmetic storage space 30a of the liquid cosmetic tank 3 described later (see FIG. 1).(Material of Liquid Cosmetic Feeder 4)

[0032] The liquid cosmetic feeder 4 is formed of a synthetic resin material. Synthetic resin materials include polyacetal (POM), polyamide (PA) <nylon>, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polycarbonate (PC), and the like.(Manufacturing Method of Liquid Cosmetic Feeder 4)

[0033] The present inventors have succeeded in the manufacturing method of the liquid cosmetic feeder 4 by an injection molding method for the first time.

[0034] Furthermore, the injection molding method in the related art was considered incapable of producing the liquid cosmetic feeder 4 with a round rod shape, featuring an ultrafine groove with the groove width dimension W1 of the liquid cosmetic flow groove 40 of about 0.1 mm, formed in both the radial and axial directions, as illustrated in FIG. 10.

[0035] The present inventors have invented a shape structure of the mold 62 described in detail below, and succeeded in manufacturing the liquid cosmetic feeder 4 with a rod shape with an ultrafine groove formed in the radial and axial directions, with the groove width dimension W1 of the liquid cosmetic flow groove 40 of about 0.1 mm, using an injection molding method. The plastic liquid cosmetic feeder 4 of the embodiment of the present invention is the liquid cosmetic feeder 4 in which an ultrafine groove with the groove width dimension W1 of the liquid cosmetic flow groove 40 of 0.1 mm is formed on the outer periphery of the liquid cosmetic feeder 4 (FIG. 3).

[0036] Therefore, manufacturing the liquid cosmetic feeder 4 using an injection molding method was considered impossible in the related art and was an unexpected development. In the extrusion molding in the related art, the material was extruded from the relatively large mold 62 and the workpiece was extended to build a thin shape. Therefore, it was possible to form a groove shape of about 0.1 mm on a liquid cosmetic feeder outer peripheral surface 43. However, significant variations occurred in the dimensions of the molded liquid cosmetic feeder 4. In particular, many variations occurred in the outer diameter of the liquid cosmetic feeder 4 (variation of about ± 0.1 mm).

[0037] This time, in order for the groove width dimension W1 of the liquid cosmetic flow groove 40 to form a groove of 0.1 mm, the structure in the mold 62 could be expressed by lamination of thin plates such as 0.1 mm, 0.2 mm, and the like, and thus the tubular body, which is the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1, was successfully manufactured by injection molding.

[0038] The liquid cosmetic feeder 4 has been integrally molded by forming the shape of the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 of interest into a comb shape, using an injection molding method described in detail below.(Liquid Cosmetic)

[0039] A liquid cosmetic that can be used for the liquid cosmetic applicator 1 of the present invention is a type of cosmetic that is liquid-like. An example is a liquid cosmetic used for an eyeliner or the like. Liquid cosmetics include facial cleansers, toners, emulsions, and serums. In the liquid cosmetic applicator 1 of the present invention, the groove width dimension W1 allows to include a pigment and a dye including a brightness agent that can circulate in an ultrafine liquid cosmetic flow groove of 0.05 mm or more and 0.2 mm or less.(Liquid Cosmetic Flow Groove 40)

[0040] The liquid cosmetic flow groove 40 is an ultrafine groove formed in the radial and axial directions on the outer periphery of the liquid cosmetic feeder 4 (see FIGS. 2, 3, 4, and 5). The groove width dimension W1 of the liquid cosmetic flow groove 40 is ultrafine, preferably being 0.05 mm or more and 0.2 mm or less. The liquid cosmetic flow groove 40 flows to the application portion 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 application portion 2 mainly by capillary action.

[0041] The cross-sectional shape of the liquid cosmetic flow groove 40 is formed in a substantially rectangular shape recessed in the vertical direction, and preferably formed in a linear manner with a comb shape in the axial direction. The liquid cosmetic flow groove 40 is recessed from the liquid cosmetic feeder outer peripheral surface 43 toward the inner side of the feeder in the radial direction and is formed in the axial direction of the liquid cosmetic feeder 4.

[0042] Each liquid cosmetic flow groove 40 flows 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 Liquid Cosmetic Flow Groove 40)

[0043] As illustrated in FIGS. 3 and 5, the liquid cosmetic flow groove 40 is formed in the liquid cosmetic feeder 4. In the cross-section in FIGS. 3 and 5, the cross-sectional shape of each of the liquid cosmetic flow grooves 40 is preferably formed in a substantially rectangular shape recessed in the vertical direction. However, the shape does not necessarily have to be a strict rectangle and may form some curves. For example, each of the liquid cosmetic flow grooves 40 may be tapered, as illustrated in part (e) of FIG. 9.

[0044] Then, each peripheral groove is formed on the peripheral surface of the liquid cosmetic feeder in a comb shape. An axial length of the liquid cosmetic flow groove 40 is preferably formed by extending in a straight line in the axial direction with a cross-sectional surface in a comb shape. However, it does not necessarily need to extend in a straight line in the axial direction, and may extend in a curved or jagged manner. The liquid cosmetic flow groove 40 flows to the application portion 2 at the front of the liquid cosmetic feeder 4 and to the liquid cosmetic tank 3 at the rear.

[0045] As illustrated in FIG. 3, in each liquid cosmetic flow groove 40, the groove width dimension W1 of the liquid cosmetic flow groove 40 of the feeder is preferably formed at a constant width in the up-down direction (vertical direction) of FIG. 3 to facilitate release from the mold or the slide core 65. The reason why the liquid cosmetic flow groove 40 was formed in parallel in a comb shape is due to the molding method described later. That is, it is derived from a core shape of the slide core 65 or the 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 (part (g) of FIG. 9).

[0046] Each liquid cosmetic flow groove 40 is formed extending in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 is recessed from the liquid cosmetic feeder outer peripheral surface 43 toward the inner side of the feeder in the radial direction and is formed in the axial direction of the liquid cosmetic feeder 4. Each liquid cosmetic flow groove 40 opens to the application portion 2 at the front of the liquid cosmetic feeder 4 and to the liquid cosmetic tank 3 at the rear of the liquid cosmetic feeder 4. Then, the liquid cosmetic flow groove 40 faces the inner peripheral surface of the hole 2a in the application portion 2 and communicates with the hole 2a of the application portion 2 and the liquid cosmetic storage space 30a of the liquid cosmetic tank 3 (see FIG. 1).(Size of Liquid Cosmetic Flow Groove 40)

[0047] The liquid cosmetic flow groove 40 of the embodiment of the present invention forms an ultrafine groove on the periphery of the liquid cosmetic feeder 4 (FIG. 3). In FIG. 3, for example, ultrafine means that the groove width dimension W1 in the horizontal direction (the left-right direction of FIG. 5) of each liquid cosmetic flow groove 40 is preferably 0.05 mm or more and 0.2 mm or less. More preferably, the groove width dimension W1 is 0.05 mm or more and 0.16 mm or less. A ratio of the groove width dimension W1 in the liquid cosmetic flow groove 40 to the outer diameter dimension D of the liquid cosmetic feeder 4 is, for example, 2.5% or more and 9.2% or less, preferably 2.5% or more and 8.2% or less. Furthermore, a depth dimension (the depth dimension of the liquid cosmetic flow groove 40) L1 in the up-down direction (the left-right direction in FIG. 5) in the liquid cosmetic flow groove 40 with respect to the outer diameter dimension D is preferably 25% or more and 40% or less, for example.

[0048] Also, in the cross-section orthogonal to the axial direction in the liquid cosmetic feeder 4, the ratio of the occupied area occupied by the liquid cosmetic flow groove 40 may be, for example, 5% or more, furthermore 10% or more, and furthermore 20% or more.(Number and Arrangement of Grooves in Liquid Cosmetic Flow Groove 40)

[0049] In the cross-section in FIG. 3, a plurality of liquid cosmetic flow grooves 40 are formed at intervals in the horizontal direction (y-direction) as illustrated in FIG. 3. In the present embodiment, the number of liquid cosmetic flow grooves 40 is 8 or 10, but the number of liquid cosmetic flow grooves 40 is not limited and can be increased or decreased as appropriate. Then, the liquid cosmetic flow grooves 40 are formed in a comb shape in parallel.

[0050] The arrangement of the liquid cosmetic flow grooves 40 is preferably such that the liquid cosmetic flow grooves 40 are arranged in parallel with each other. This differs from the liquid cosmetic feeder 4 in the related art in that the liquid cosmetic flow groove 40 is formed in a radial manner toward a center point of the shaft (see FIG. 10). This parallel shape (comb shape) facilitates releasing from the mold 62 as described later, and it is possible to manufacture the liquid cosmetic feeder 4 by an injection molding method.

[0051] In the sense that the liquid cosmetic flow grooves 40 are arranged in parallel with each other, the meaning may not be applied to be strictly parallel, and the comb-shaped plate member of the mold or the slide core 65 may be formed in parallel enough to be released from the liquid cosmetic feeder, which is an injection molded and solidified molded product.(Transverse Groove of Liquid Cosmetic Flow Groove 40)

[0052] The number of grooves in the liquid cosmetic flow groove 40 is not particularly limited. A liquid cosmetic flow rate can be adjusted by the number of grooves formed. Note that in the above embodiment, a transverse groove (not illustrated) connecting the liquid cosmetic flow grooves adjacent to the feeder in the peripheral direction may be further provided on the outer peripheral surface of the liquid cosmetic flow groove 40. That is, such a transverse groove extends in the feeder circumferential direction across the liquid cosmetic flow groove 40. Such a transverse groove makes it possible to transfer the liquid cosmetic P between the liquid cosmetic flow grooves 40, and furthermore, it is possible to smoothly flow the liquid cosmetic P toward the front end side.(Modification of Liquid Cosmetic Flow Groove 40)

[0053] A modification of the liquid cosmetic flow groove 40 is illustrated in FIG. 9. As illustrated in part (b), the number of liquid cosmetic flow grooves 40 may increase or decrease. As illustrated in part (c), the groove width dimension W1 of the liquid cosmetic flow groove 40 may be narrower. As illustrated in part (d), the groove width dimension W1 of the respective liquid cosmetic flow grooves 40 may be mixed broadly and narrowly. As illustrated in part (e), the respective liquid cosmetic flow grooves 40 may be tapered. As illustrated in part (f), the depth of the respective liquid cosmetic flow grooves 40 may be varied. As illustrated in part (g), shapes of bottoms of the grooves of the respective liquid cosmetic flow grooves 40 may be a round bottom. As illustrated in part (h), shapes of external shapes of the respective liquid cosmetic feeders may be as illustrated. As illustrated in part (i), the number of slide cores 65 may be increased or decreased as illustrated. As illustrated in part (j), a flow groove may be formed inside the liquid cosmetic feeder. As illustrated in part (k), the size of the mold rib receiving portion 42 may be changed.(Formation of Mold Rib Receiving Portion 42)

[0054] In the embodiment of the present invention, as illustrated in FIGS. 2 and 4, the mold rib receiving portion 42 is formed as a recessed groove in the axial direction on the liquid cosmetic feeder outer peripheral surface 43 of the liquid cosmetic feeder 4. The shape of the mold rib receiving portion 42 is not limited to the shape, as long as the liquid cosmetic feeder, which is the molded product, can be caught in a mold rib 623 in the release process. In the embodiment of the present invention, the shape is made 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 4, which is the molded product, can be caught in the mold rib 623 in the release process.

[0055] Since the mold rib receiving portion 42 is formed, in the process of opening the slide core 65 during injection molding, the mold rib receiving portion 42 of the liquid cosmetic feeder 4, which is the molded product, contacts the mold rib 623 of the mold 62 and allows release from the mold 62.

[0056] The mold rib receiving portion 42 may be formed in the same shape (groove width, groove depth, and groove radial length) as the liquid cosmetic flow groove 40. In this case, the mold rib receiving portion 42 can also function as the liquid cosmetic flow groove 40.

[0057] As described above, the present inventors succeeded in forming the liquid cosmetic flow groove 40 by the injection molding method of the liquid cosmetic feeder, and for the first time, the injection molding method of the liquid cosmetic feeder 4 was possible.(Injection Molding Method)

[0058] Next, the injection molding method of the liquid cosmetic feeder 4 of the present embodiment will be described with reference to FIG. 6. The manufacturing method of the liquid cosmetic feeder 4 molds a synthetic resin material into a predetermined shape and size by the injection molding machine 60. In the present invention, since the shape of the liquid cosmetic feeder can be completed in the injection molding process, a cutting processing process such as front end processing and rear end processing, and a full length cutting process are not required. Cutting processing such as front end processing, rear end processing, and full-length extrusion cutting is not necessary in the injection molding method of the present invention. All of the mold shapes can be completed by forming the shape of the liquid cosmetic feeder 4 in the mold shape.

[0059] Hereinafter, the injection molding method of the liquid cosmetic feeder 4 according to the present embodiment will be described in detail. The liquid cosmetic feeder 4 of the present embodiment is manufactured by an injection molding method. The injection molding method of the present embodiment is a technique in which a synthetic resin 61 of a plastic material melted at a high temperature is injected into the mold 62 for injection molding, cooled, and molded by applying a high pressure.(Process of Injection Molding Method)

[0060] Procedures of the injection molding method are described below.1. Preparation of Material

[0061] First, the material is accumulated in a hopper once, supplied to an injection unit little by little, and fed into a heated portion of the injection unit by a driving device 64.2. Mold Clamping

[0062] The mold 62 consists of two parts. One mold 62 is aligned with the other mold 62 and mold clamping is performed. In the injection molding of the present embodiment, the mold 62 may be provided with the slide core 65.3. Injection

[0063] The melted material is injected into the mold 62.4. Pressure Retention

[0064] The injected material keeps the mold 62 at a pressure that is easy to solidify.5. Cooling

[0065] Cooling and solidification is performed.6. Mold Opening

[0066] After cooling and confirming sufficient solidification, a movable side of the mold is opened.7. Product Ejection

[0067] The product is ejected. Since one of the mold 62 is fixed, the molded product is pushed with an ejector pin 67 to be ejected.(Injection Molding Machine 60)

[0068] The liquid cosmetic feeder 4 of the present embodiment can be manufactured, for example, by the injection molding machine 60 as illustrated in part (a) of FIG. 6. The injection molding machine 60 that can be used in the present embodiment includes three parts: the driving device 64 that feeds the material, a nozzle 68 that heats the material using a heater 66 to make the material suitable for injection, and a mold clamping unit 63 for molding in the mold 62.(Operation of Injection Molding Machine 60)

[0069] The mold 62 for injection molding is a metal mold into which the synthetic resin 61 as materials is injected to form a predetermined shape. Basically, the mold consists of two molds 62 and is opened and closed by the mold clamping unit 63.(Mold 62)

[0070] Since the mold 62 needs to ensure dimensional accuracy at a constant number of shots while repeatedly applying pressure, heat, friction, and the like, die steel, high-speed steel, cemented carbide, ceramics, and the like that are hard and have high durability are used.

[0071] Part (a) of FIG. 7 is a cross-sectional view of the mold with the slide core 65, and part (b) of FIG. 7 is a cross-sectional view of the mold without a slide core.(Structure of Slide Core 65)

[0072] In the liquid cosmetic feeder 4 of the present embodiment, as illustrated in part (c) of FIG. 6, the liquid cosmetic feeder 4 can be manufactured even if the mold is combined with the slide core 65. The structure of the slide core 65 can be fabricated by laminating a first plate-shaped member 651 having a plate thickness of 0.1 mm and a second plate-shaped member 652 having a plate thickness of 0.2 mm. For the method of coupling the first plate-shaped member 651 and the second plate-shaped member 652, there are various methods, but for example, the following methods can be used.

[0073] Method of using an adhesive: It is a method of adhering metal plates using an adhesive for metal. Depending on the type of adhesive, it is possible to adhere with high strength and excellent durability.

[0074] Method of using welding: It is a method of welding metal plates. There are types of welding, such as arc welding, gas welding, and laser welding, and laser welding may be optimal for ultra-thin metal sheets.

[0075] Plate-shaped parts having a thickness of 0.1 mm and a thickness of 0.2 mm are incorporated into the slide core 65. This forms a comb-shaped core in the slide core 65.(Release from Mold 65 with Slide Core)

[0076] In the release method from the mold 62 after injection, as illustrated in part (b) of FIG. 6, the upper and lower slide cores 65 are released from constraint of an angular pin 624 and move up and down. At this point, the liquid cosmetic feeder 4, which is the injection molded product, is held in the mold rib 623 and does not adhere to and follow the upper and lower slide cores 65. Thereafter, the injection molded liquid cosmetic feeder 4 is pushed out by the operation of the ejector pin 67 and completely released from the mold.

[0077] In the slide core 65 of the mold 62, the first plate-shaped member 651 and the second plate-shaped member 652 are alternately fixed in parallel. In the present embodiment, the first plate-shaped member 651 having a thickness of 0.1 mm and the second plate-shaped member 652 having a thickness of 0.2 mm are alternately incorporated into the slide core 65 of the mold 62. By opening the slide core 65 up and down, the molded product is ejected from the mold 62.

[0078] In the present embodiment, the left-right opening of the mold 62 and the up-down opening of the slide core 65 operate simultaneously. However, the mold 62 may be opened left and right first, and then the slide core 65 may be opened up and down in sequence. Also, in the present embodiment, the liquid cosmetic feeder 4 is injection-molded with the axis orientation set in the vertical direction (z-axis direction) with respect to the plane of the drawings as illustrated in part (b) of FIG. 6, but may be injection-molded with the axis orientation set in the horizontal direction (x-axis direction) as illustrated in part (c) of FIG. 6.(Release from Mold without Slide Core)

[0079] The mold 62 with the slide core is complex in structure and does not necessarily need to be provided with the slide core 65 in the mold 62 of the present invention. The use of the following mold 62 is also within the scope of the present invention.

[0080] In other words, by forming the first plate-shaped member 651 and the second plate-shaped member 652 in the horizontal direction of the mold 62, it is possible to injection-mold without requiring the slide core 65 (part (b) of FIG. 7).

[0081] In the release method from the mold 62 after injection, as illustrated in part (b) of FIG. 7, the left and right molds 62 are first opened left and right by a mold opening and closing device (not illustrated). At this point, the liquid cosmetic feeder 4 is released from the right mold 62. Then, the liquid cosmetic feeder 4, which is the injection molded product, is held in the mold rib 623 and then pushed out by the operation of the ejector pin 67 and is completely released from the mold.(Mold Rib 623)

[0082] In the present embodiment, the mold ribs 623 are formed near the center of the left and right molds 62, respectively (part (d) of FIG. 6). When the slide core 65 of the present embodiment is opened up and down, the molded product is caught in the mold rib 623. Therefore, the molded product can be easily released from the slide core 65. The shape of the mold rib 623 is not particularly limited as long as the molded product can be easily released from the slide core 65. For example, the shape may be a shape that can fit into a recess somewhere in the molded product. The mold ribs 623 may also be formed in one of the left and right molds 62. The present inventors have succeeded in easily releasing the molded product from the mold 62 by providing such a convex shape in the mold 62.

[0083] Then, by pushing up the molded product with the ejector pin 67, the molded product can be completely ejected from the mold 62.

[0084] When the slide core 65 is opened up and down, the plate parts of the mold 62 and the molded product are closely connected, so that the molded product remains in one slide core 65, and the molded product cannot be released from the mold 62.

[0085] To prevent this, it is necessary to leave the liquid cosmetic feeder 4 on the mold 62 to eject the liquid cosmetic feeder 4 from the mold 62. Therefore, in the present embodiment, release ribs are formed in the mold 62 (part (c) of FIG. 6). In the present embodiment, the mold ribs 623 are formed in centers on both sides of the mold 62, but if there is a release rib that can temporarily hold the liquid cosmetic feeder 4 in the mold 62, the formation position of the mold rib 623 may be shifted from the centers. The release ribs may be formed in one of the male and female types.

[0086] As long as the shape and the like that enable the liquid cosmetic feeder 4 to be temporarily held in the mold 62, the release ribs can be used in the present invention without limiting the shape, number, and length thereof.

[0087] In an injection molding method, it has been stated that it is impossible to create a shape such as the liquid cosmetic feeder 4 with a 0.1 mm groove communicating through.

[0088] Since the extrusion mold extrudes from the relatively large mold 62 and extends the workpiece to build a thin shape, extrusion molding makes possible to create a groove shape of 0.1 mm.

[0089] Due to such a manufacturing method, great variation in the dimension occurs in the extrusion molding in the related art. In particular, variation in the outer diameter becomes large (variation of about ± 0.1 mm). It is completely inconceivable in this industry to make the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 with a groove of 0.1 mm communicating through with the injection molding method.

[0090] This time, to form a groove of 0.1 mm, the structure in the mold 62 was successfully expressed by lamination of thin plates such as 0.1 mm, 0.2 mm, and the like, and the liquid cosmetic feeder 4 of 1 was successfully manufactured by injection molding.(Cosmetic Applicator)

[0091] The liquid cosmetic feeder 4 of the present embodiment can be mounted on various liquid cosmetic applicators 1. Hereinafter, each part of the liquid cosmetic applicator 1 to which the liquid cosmetic feeder 4 of the present embodiment is mounted will be described. The following example describes an eyeliner as an example of the liquid cosmetic applicator 1.

[0092] The liquid cosmetic feeder 4 of the present invention is a core provided for "relaying" the liquid cosmetic P to the application portion 2. The liquid cosmetic feeder 4 can be applied to any liquid cosmetic applicator 1 as long as the liquid cosmetic feeder 4 is rod-shaped, the rear end portion is immersed in the liquid cosmetic P, and the front end portion can be connected to the application portion 2. In particular, the liquid cosmetic feeder 4 of the present embodiment can be mounted on an eyeliner, an eyebrow, a shadow liner, a concealer, and the like.(Application Portion)

[0093] The application portion 2 is, for example, a brush, and is a fibrous aggregate consisting of a synthetic resin such as nylon or PBT (polybutylene terephthalate). The application portion 2 is not limited to a brush, but may be, for example, of a sintered pen type or formed of porous urethane. When the liquid cosmetic P contains a solid, the application portion 2 is preferably a brush. In particular, when the liquid cosmetic P contains a solid, the application portion 2 is preferably made of a bundle of synthetic fibers such as nylon having flexibility, elasticity, and flexibility.

[0094] As illustrated in FIG. 1, the application portion 2 has a round rod shape extending in the axial direction (longitudinal direction) centered on the axis O. The application portion 2 has a conical shape in which the outer diameter gradually decreases from a mid-position in the axial direction toward the front end side. As illustrated in FIG. 2, the end surface of the rear end side of the application portion 2 is formed with the hole 2a recessed toward the front end side. The hole 2a has a tapered shape in which the inner diameter gradually decreases from the rear end side to the front end side. The inner diameter of the hole 2a may be equivalent to the outer diameter of the liquid cosmetic feeder 4 described later, but the inner diameter of the hole 2a may be slightly larger than the outer diameter of the liquid cosmetic feeder 4. As a result, a space (clearance) in which the liquid cosmetic P can flow may be formed between the outer peripheral surface of the liquid cosmetic feeder 4 and the inner peripheral surface of the hole 2a.

[0095] Also, the end of the rear end side of the application portion 2 is provided with a fastening layer 20 that bundles each fiber of the application portion 2. The above-described hole 2a penetrates the fastening layer 20. The fastening layer 20 is formed by, for example, adhering the fibers of the application portion 2 to each other by an adhesive material or the like. The fastening layer 20 has a disk shape centered on the axis O. The outer diameter of the fastening layer 20 is slightly larger than the outer diameter of the application portion 2, so that the fastening layer 20 protrudes in a flange shape from the application portion 2 to the outer peripheral side.(Liquid Cosmetic Tank 3)

[0096] Referring back to FIG. 1, the liquid cosmetic tank 3 is provided extending from the end of the rear end side of the liquid cosmetic feeder 4 to the rear end side.

[0097] The liquid cosmetic tank 3 includes an outer cylindrical portion 30 that extends in the axial direction and a tail plug 39 that blocks the rear end side of the outer cylindrical portion 30. The space surrounded by the outer cylindrical portion 30, the tail plug 39, and the pressure fluctuation buffer member 5 described later is the liquid cosmetic storage space 30a that accommodates the paint. The liquid cosmetic storage space 30a accommodates liquid paint and liquid paint containing a solid as the liquid cosmetic P. The liquid paint is a liquid cosmetic used for the eyeliner, for example.

[0098] Solids have a higher specific gravity than liquid paints, such as metal powders such as titanium and aluminum, laminates made of thin films such as gold, silver, aluminum, tin, and the like by evaporation deposition, and inorganic substances such as glass beads. The viscosity of the liquid cosmetic P containing the solid is preferably about 30 mPa·s or less.

[0099] A stirring member M is accommodated in the liquid cosmetic storage space 30a in the liquid cosmetic tank 3. By shaking the entire liquid cosmetic applicator 1 in the axial direction, the liquid cosmetic P in the liquid cosmetic tank 3 can be stirred by the stirring member M. Furthermore, the shape of the stirring member M is not limited and may be, for example, spherical, cylindrical, polyhedral, cubic, or a rectangular, and any other polyhedral shape. Depending on the type of the liquid cosmetic P, the stirring member M may not necessarily be provided.(Outer Cylindrical Portion)

[0100] The outer cylindrical portion 30 includes the liquid cosmetic storage space 30a and a feeder storage area 30b extending further to the front end side from the liquid cosmetic storage space 30a. The feeder storage area 30b is disposed outside the feeder in the radial direction of the liquid cosmetic feeder 4, is provided at a position that overlaps the liquid cosmetic feeder 4 from the viewpoint of the feeder radial direction, and covers the liquid cosmetic feeder 4. The feeder storage area 30b has a tapered shape in which the outer diameter gradually decreases from a mid-position in the axial direction toward the front end side. As illustrated in FIG. 2, the end on the front end side of the feeder storage area 30b is disposed outside the feeder in the radial direction with respect to the application portion 2, is provided in a position that overlaps the application portion 2 from the viewpoint of the feeder radial direction, and covers the application portion 2.

[0101] Furthermore, in the inner surface of the front end side of the outer cylindrical portion 30, an outer cylinder first step surface 31 that faces the rear end side in the axial direction and forms an annular shape centered on the axis O and an outer cylinder second step surface 32 that is arranged on the rear end side of the outer cylinder first step surface 31 and forms an annular shape centered on the axis O are formed at intervals in the axial direction. As a result, the feeder storage area 30b in the outer cylindrical portion 30 is formed with an outer cylinder first recess 33 and an outer cylinder second recess 34 that are annularly recessed about the axis O from the inner peripheral surface of the outer cylindrical portion 30 to the outer side of the feeder in the radial direction. Accordingly, the inner diameter of the outer cylindrical portion 30 gradually decreases toward the front end side. In the outer cylindrical portion 30, an air flow groove 30x that communicates with the outer cylinder first recess 33, extends in the axial direction, and opens to the end surface of the front end side of the outer cylindrical portion 30 is formed in a portion of the feeder in the circumferential direction. The air is exchanged in and out of a buffer space K described later via the air flow groove 30x, the outer cylinder first recess 33, and the outer cylinder second recess 34. The feeder storage area 30b in the outer cylindrical portion 30 is provided with an outer cylinder flange 35 that protrudes annularly outside of the feeder in the radial direction at a position in the middle of the axial direction that is the rear end side of the outer cylinder second step surface 32 (see FIG. 2).(Inner Cylindrical Portion)

[0102] Furthermore, an inner cylindrical portion 36 is provided between the outer cylindrical portion 30 and the application portion 2. The inner cylindrical portion 36 extends in the axial direction and engages the fastening layer 20 and the outer cylindrical portion 30. The inner cylindrical portion 36 is covered by pressing the end of the rear end side of the application portion 2 from the outside of the feeder in the radial direction. Specifically, the outer peripheral surface of the inner cylindrical portion 36 is formed with an inner cylinder outer step surface 36a that faces the front end side in the axial direction and is annular about the axis O. Due to the inner cylinder outer step surface 36a, the outer peripheral surface of the inner cylindrical portion 36 is formed with an outer protrusion 37 that protrudes outside of the feeder in the radial direction and is annular about the axis O. Accordingly, the outer diameter of the inner cylindrical portion 36 is larger at the rear end side compared to the front end side.

[0103] The outer protrusion 37 of the inner cylindrical portion 36 is disposed in the outer cylinder first recess 33 of the outer cylindrical portion 30, and the inner cylindrical portion 36 is disposed so that the inner cylinder outer step surface 36a of the inner cylindrical portion 36 faces the outer cylinder first step surface 31 of the outer cylindrical portion 30 in the axial direction. Accordingly, the inner cylinder outer step surface 36a of the inner cylindrical portion 36 and the outer cylinder first step surface 31 of the outer cylindrical portion 30 are engaged, and the inner cylindrical portion 36 is engaged to the outer cylindrical portion 30. Furthermore, the inner peripheral surface of the inner cylindrical portion 36 is formed with an inner cylinder inner step surface 36b that is disposed on the rear end side of the inner cylinder outer step surface 36a, faces the rear end side, and is annular about the axis O. Due to the inner cylinder inner step surface 36b, the inner peripheral surface of the inner cylindrical portion 36 is formed with an inner recess 38 that is concave outside the feeder in the radial direction and is annular about the axis O. The fastening layer 20 is disposed in the inner recess 38 to engage the inner cylindrical portion 36 and the fastening layer 20, and the outer cylindrical portion 30 supports the application portion 2 via the inner cylindrical portion 36.(Outer Case)

[0104] An outer case 6 abuts from the rear end side to the outer cylindrical flange 35 of the outer cylindrical portion 30 in the axial direction, and covers the outer cylindrical portion 30 from the outside of the feeder radial direction in the rear end side of the outer cylindrical flange 35. In other words, the outer case 6 has a bottomed cylindrical shape that extends in the axial direction about the axis O so that the outer cylindrical portion 30 can be inserted. The outer cylindrical portion 30 is fitted to the outer case 6, and the outer case 6 and the outer cylindrical portion 30 are fixed. Inside the outer case 6, a rear end space S2 is formed in a region sandwiched between a bottom surface of the outer case 6 and the tail plug 39 in the liquid cosmetic tank 3 (see FIG. 1).(Pressure Fluctuation Buffer Member 5)

[0105] As illustrated in FIG. 5, the pressure fluctuation buffer member 5 includes a feeder holding cylinder 50 and a buffer mechanism 51 that forms the buffer space K between the feeder holding cylinder 50 and the inner peripheral surface of the outer cylindrical portion 30 outside in the feeder radial direction of the feeder holding cylinder 50. The pressure fluctuation buffer member 5 is formed of a synthetic resin. When the liquid cosmetic P in the liquid cosmetic tank 3 is an aqueous paint, the synthetic resin can be an ABS resin, an AS resin, a PET resin, a PBT resin, a styrene resin, a POM resin, polycarbonate, polyamide, modified polyphenylene ether, and the like. If the liquid cosmetic P in the liquid cosmetic tank 3 is an oil-based paint (especially paint with alcohol as a main solvent), a PE resin, a PP resin, a POM resin, a PET resin, a PBT resin, polyamide, and the like can be used as the synthetic resin.(Feeder Holding Cylinder)

[0106] The feeder holding cylinder 50 extends in the axial direction. The feeder holding cylinder 50 includes a main body cylindrical portion 52 through which the liquid cosmetic feeder 4 is inserted in a cylindrical shape centered on the axis O, and an extension 53 integrally provided with the main body cylindrical portion 52 at the rear end side of the main body cylinder portion 52.

[0107] Since the liquid cosmetic feeder 4 is fitted to the main body cylindrical portion 52, the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 faces the feeder in the radial direction on the inner peripheral surface of the main body cylindrical portion 52. The liquid cosmetic feeder outer peripheral surface 43 of the liquid cosmetic feeder 4 (see FIG. 3) contacts the inner peripheral surface of the main body cylindrical portion 52. A dimension W2 between grooves in the feeder horizontal direction of the liquid cosmetic feeder outer peripheral surface 43 (see FIG. 3) is very small, and since the liquid cosmetic feeder 4 is fitted to the main body cylindrical portion 52, a very small gap (not illustrated) is formed between the main body cylindrical portion 52 and the liquid cosmetic feeder 4. Due to this small gap, a space in which the liquid cosmetic flow grooves 40 adjacent in the horizontal direction communicate exists between the main body cylindrical portion 52 and the liquid cosmetic feeder 4.(Connecting Flow Path)

[0108] Furthermore, a connecting flow path F communicating with the liquid cosmetic flow groove 40 is formed in the main body cylindrical portion 52 in the pressure fluctuation buffer member 5. Although the liquid cosmetic flow groove 40 is formed so that the liquid cosmetic P is more present between the pressure fluctuation buffer member 5 and the liquid cosmetic feeder 4, entry of the liquid cosmetic P into the buffer space K can be improved by the connecting flow path F to avoid leakage of the liquid cosmetic P. By providing the connecting flow path F, air is moved between the buffer space K and the liquid cosmetic storage space 30a, and the liquid cosmetic P is moved between the buffer space K and the liquid cosmetic flow groove 40 by the connecting flow path F, thereby effectively reducing leakage of the liquid cosmetic P.

[0109] Note that in the above embodiment, a transverse groove (not illustrated) connecting the liquid cosmetic flow grooves 40 adjacent in the feeder peripheral direction may be further provided on the outer peripheral surface of the liquid cosmetic feeder 4. That is, such a transverse groove extends in the feeder circumferential direction across the liquid cosmetic flow groove 40. Such a transverse groove makes it possible to transfer the liquid cosmetic P between the liquid cosmetic flow grooves 40, and furthermore, it is possible to smoothly flow the liquid cosmetic P toward the front end side.

[0110] Although the eyeliner is described above as an example of the liquid cosmetic applicator 1, sufficient functions can be performed even if the liquid cosmetic feeder 4 is mounted on the liquid cosmetic applicator 1 other than the eyeliner, for example, the liquid cosmetic applicator 1 such as an eyebrow, a shadow liner, and a concealer.(Buffer Mechanism)

[0111] A buffer mechanism 51 is integrally formed with the feeder holding cylinder 50. The buffer mechanism 51 includes a partition member 56 that protrudes annularly from the main body cylindrical portion 52 to the outside of the feeder radial direction and is centered on the axis O at a mid-position in the axial direction of the main body cylindrical portion 52, a first convex member 57 formed on the outer peripheral surface of the main body cylindrical portion 52 at the rear end side of the partition member 56, and a second convex member 58 formed on the outer peripheral surface of the main body cylindrical portion 52 at the front end side of the partition member 56.

[0112] Hereinafter, examples will be specifically described to enhance the understanding of the present invention. However, the scope of the present invention is not limited to the following examples.(Example 1)

[0113] The liquid cosmetic feeder 4 was manufactured by injection molding, and an eyeliner was manufactured using the same. In the present example 1, cutting processing such as front end processing and rear end processing, which is a post-process, was not performed.

[0114] The mold 62 molding the liquid cosmetic feeder 4 was fabricated by laminating thin plates with plate thicknesses of 0.1 mm and 0.2 mm to manufacture the mold 62 of the liquid cosmetic feeder 4 (part (c) of FIG. 6).

[0115] A comb shape corresponding to the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 with the groove width dimension W1 of 0.1 mm is formed in the mold 62. Then, the injection molding machine 60 (FIG. 6) with the mold 62 attached succeeded in manufacturing the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 by the injection molding method.

[0116] The liquid cosmetic feeder 4 manufactured by the injection molding method was incorporated into the feeder holding cylinder 50 to manufacture the liquid cosmetic applicator 1 (eyeliner) (FIG. 4).

[0117] In FIG. 4, the liquid cosmetic feeder 4 was press-fitted into the feeder holding cylinder 50.

[0118] In the present example, the variation in the outer diameter dimension D of the liquid cosmetic applicator 1 was reduced within ± 0.02 mm by the injection molding method, and an assembly defect rate was reduced.

[0119] The assembly defect rate of the liquid cosmetic applicator 1 by the injection molding method was 0 out of 100 (0% defect rate). From the viewpoint that the defect rate was 35% in the case of Comparative Example 1 below, it was confirmed that according to the injection molding method and the liquid cosmetic feeder 4 of the present invention, it is possible to manufacture a stabilized liquid cosmetic feeder 4 with excellent dimensions.(Example 2)

[0120] As Example 2, the eyeliner illustrated in FIG. 5 was manufactured.

[0121] The difference from Example 1 is that the liquid cosmetic feeder 4 was fixed to the main body cylindrical portion 52 by providing a step to prevent the liquid cosmetic feeder 4 from coming off (not press-fitted). As a result, the results were different from those of the eyeliner of Example 1 in terms of matching with formulation, prevention of cracking of the front end of the brush, an assembly method, and the like.

[0122] Performance of the liquid cosmetic applicator 1 of Example 1 incorporating the liquid cosmetic feeder 4 manufactured by the injection molding was then checked.(Comparative Example 1)

[0123] When the molding method was used as the extrusion molding with the same condition in Example 1, assembly defects in the outer capillary tube bodies of Example 1 occurred in 17 out of 48 units (35% defect rate).(Performance Test 1 Performance Test of Liquid Cosmetic with Dye)•Formulation: Dye (Containing Brightness Agent)

[0124] Brown (Containing Brightness Agent) Purple (Containing Brightness Agent) Pink (Containing Brightness Agent) ▪ Injection-molded outer capillary tube body (outer diameter φ1.8 groove width 0.1 mm number of grooves 8)1. Writing Test

[0125] (Test method) Using one liquid cosmetic applicator 1, 200 lines of approximately 4 cm length were written on a piece of high-quality paper, and handwriting was visually checked for smudges.(Number of Tests) n = 1(Test Results)

[0126] In the case of brown (containing brightness agent), the handwriting was good with no smudges. In the case of purple (containing brightness agent), the handwriting was good with no smudges. In the case of pink (containing brightness agent), the handwriting was good with no smudges. In the case of any dye formulation, a sufficient function as the liquid cosmetic applicator 1 was exhibited, resulting in a good result for actual use.2. Time-Lapse Test

[0127] (Test Method) The pens were placed with the front end facing upward, sideways, and downward in a thermostatic chamber at 40°C or higher for one month, and then ten lines of about 4 cm length were written on high-quality paper to check for smudges of the handwriting.(Number of Tests) Upward, Sideways, and Downward n = 3 each

[0128] (Test Results) In all orientations of upward, sideways, and downward, brown (containing brightness agent) produced good handwriting with no smudges. Purple (containing brightness agent) produced good handwriting with no smudges. Pink (containing brightness agent) produced good handwriting with no smudges.

[0129] Even in the above time-lapse test, no smudges occurred in all formulations. Handwriting was good. It can be said that a sufficient function as the liquid cosmetic applicator 1 was exhibited. The results were good for actual use.3. Forced Pump Test

[0130] (Test Method) The applicator is left facing downward in a thermostatic chamber at 40°C or higher for 24 hours.

[0131] After 24 hours, after immediately removing from the thermostatic chamber and facing downward, the cap fitting was repeated 100 times.(Number of Tests) n = 3(Test Results)

[0132] Brown (containing brightness agent)No leakage even after 100 timesPurple (containing brightness agent)No leakage even after 100 timesPink (containing brightness agent)No leakage even after 100 times

[0133] All exhibited a sufficient function as the liquid cosmetic applicator 1. The results were good for actual use.4. Half-Cap Leakage Test(Test Method)

[0134] The cap was opened halfway and placed in a thermostatic chamber at 40°C or higher with the cap facing downward, and left for 24 hours. After that, the applicator was removed from the thermostatic chamber and check for leakage.(Number of Tests) n = 3(Test Results)

[0135] Brown (containing brightness agent)No leakagePurple (containing brightness agent)No leakagePink (containing brightness agent)No leakage

[0136] All exhibited a sufficient function as the liquid cosmetic applicator 1. The results were good for actual use.5. Decompression Test

[0137] (Formulation)Containing pink brightness agent (Test Method)

[0138] The cap was removed, the front end of the pen was pointed downward, and the pressure was lowered from 1 atm. The lowered state was observed for 1 minute to check for leakage. (Test Method)n = 3(Test Results)No leakage was observed.

[0139] A sufficient function was exhibited as the liquid cosmetic applicator 1. The results were good for actual use.(Performance Test 2 Performance Test of Liquid Cosmetic P with Pigment)

[0140] The number of grooves was increased to 10, and a writing test of the liquid cosmetic was performed using the liquid cosmetic P as a pigment.•Formulation: Pigment (No brightness agent)

[0141] Black Brown Brown Black Green ▪ Injection-molded outer capillary tube body (outer diameter φ1.8 groove width 0.1 mm number of grooves 10)Writing Test(Test Method)

[0142] Using one liquid cosmetic applicator 1, 200 lines of approximately 4 cm length were written on a piece of high-quality paper, and handwriting was visually checked for smudges. (Number of Tests)n = 1(Test Results)BlackGood handwriting with no smudgesBrownGood handwriting with no smudgesBrown BlackGood handwriting with no smudgesGreenGood handwriting with no smudges

[0143] All exhibited a sufficient function as the liquid cosmetic applicator 1. The results were good for actual use.

[0144] Finally, the writing test results for formulations containing high-brightness agents in the pigment formulation are reported.(Performance Test 3 Test with Pigment Containing High-Brightness Agent)•Formulation: Pigment (Containing High-Brightness Agent)

[0145] Red (Containing High-Brightness Agent) Blue (Containing High-Brightness Agent) Lavender (Containing High-Brightness Agent) Green (Containing High-Brightness Agent) Navy (Containing High-Brightness Agent) Pink (Containing High-Brightness Agent) Brown (Containing High-Brightness Agent) Brown (Containing Brightness Agent) ▪ Injection-molded outer capillary tube body (outer diameter φ1.9 groove width 0.13 mm number of grooves 12, two of which serve as both the groove for the mold rib receiving portion and the liquid cosmetic flow groove)1. Writing Test(Test Method)

[0146] Using one liquid cosmetic applicator 1, 200 lines of approximately 4 cm length were written on a piece of high-quality paper, and handwriting was visually checked for smudges.(Test Results)

[0147] Red (Containing High-Brightness Agent) Good handwriting with no smudges Blue (Containing High-Brightness Agent) Good handwriting with no smudges Lavender (Containing High-Brightness Agent) Good handwriting with no smudges Green (Containing High-Brightness Agent) Good handwriting with no smudges Navy (Containing High-Brightness Agent) Good handwriting with no smudges Pink (Containing High-Brightness Agent) Good handwriting with no smudges Brown (Containing Brightness Agent) Good handwriting with no smudges Brown (Containing Brightness Agent) Good handwriting with no smudges

[0148] All formulations produced good results with good handwriting and no smudges. A sufficient function was exhibited as a liquid cosmetic applicator such as an eyeliner, an eyebrow, a shadow liner (a cosmetic applicator for applying makeup to the tear trough on the face), and a concealer. The results were good for actual use.INDUSTRIAL APPLICABILITY

[0149] The liquid cosmetic feeder 4 of the present invention can smoothly guide and discharge the liquid cosmetic P.REFERENCE SIGNS LIST

[0150] 1: liquid cosmetic applicator 1 2: application member 2a: hole 3: liquid cosmetic tank 4: liquid cosmetic feeder 5: pressure fluctuation buffer member 6: outer case 20: fastening layer 30: outer cylindrical portion 30a: liquid cosmetic storage space 30b: feeder storage area 30x: air flow groove 31: outer cylinder first stage difference surface 32: outer cylinder second stage difference surface 33: outer cylinder first recess 34: outer cylinder second recess 35: outer cylinder flange 36: inner cylindrical portion 36a: inner cylinder outer step surface 36b: inner cylinder inner step surface 37: outer protrusion 38: inner recess 39: tail plug 40: liquid cosmetic flow groove 42: mold rib receiving portion 43: liquid cosmetic feeder outer peripheral surface 44: step portion 50: feeder holding cylinder 51: buffer mechanism 52: main body cylindrical portion 53: extension 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: driving device 65: slide core 651: first plate-shaped part 652: second plate-shaped part 66: heater 67: ejector pin 68: nozzle D: outer diameter dimension F: connecting flow path K. buffer space L1: depth dimension of liquid cosmetic flow groove 40 M: stirring member O: axis P: liquid cosmetic S1: front end space S2: rear end space W1: groove width dimension W2: dimension between grooves

Examples

example 1

(Example 1)

[0113]The liquid cosmetic feeder 4 was manufactured by injection molding, and an eyeliner was manufactured using the same. In the present example 1, cutting processing such as front end processing and rear end processing, which is a post-process, was not performed.

[0114]The mold 62 molding the liquid cosmetic feeder 4 was fabricated by laminating thin plates with plate thicknesses of 0.1 mm and 0.2 mm to manufacture the mold 62 of the liquid cosmetic feeder 4 (part (c) of FIG. 6).

[0115]A comb shape corresponding to the liquid cosmetic flow groove 40 of the liquid cosmetic feeder 4 with the groove width dimension W1 of 0.1 mm is formed in the mold 62. Then, the injection molding machine 60 (FIG. 6) with the mold 62 attached succeeded in manufacturing the liquid cosmetic feeder 4 of the liquid cosmetic applicator 1 by the injection molding method.

[0116]The liquid cosmetic feeder 4 manufactured by the injection molding method was incorporated into the feeder holding cylinder...

example 2

(Example 2)

[0120]As Example 2, the eyeliner illustrated in FIG. 5 was manufactured.

[0121]The difference from Example 1 is that the liquid cosmetic feeder 4 was fixed to the main body cylindrical portion 52 by providing a step to prevent the liquid cosmetic feeder 4 from coming off (not press-fitted). As a result, the results were different from those of the eyeliner of Example 1 in terms of matching with formulation, prevention of cracking of the front end of the brush, an assembly method, and the like.

[0122]Performance of the liquid cosmetic applicator 1 of Example 1 incorporating the liquid cosmetic feeder 4 manufactured by the injection molding was then checked.

Claims

1. A liquid cosmetic feeder used for a liquid cosmetic applicator, wherein the liquid cosmetic feeder is a liquid cosmetic feeder that is injection-molded out of a synthetic resin, and the liquid cosmetic feeder is formed with an ultrafine liquid cosmetic flow groove.

2. The liquid cosmetic feeder according to claim 1, wherein the liquid cosmetic feeder is further formed with a mold rib receiving portion.

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

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

5. A method of manufacturing a liquid cosmetic feeder, wherein an ultrafine liquid cosmetic flow groove for flowing a liquid cosmetic is formed on an outer periphery, by an injection molding method in which a heat-melted synthetic resin material is injected into a mold and cooled to obtain a molded product.

6. The method of manufacturing the liquid cosmetic feeder according to claim 5, wherein the method of manufacturing the liquid cosmetic feeder is the manufacturing method that does not include a cutting processing process, which is a post-process.

7. The method of manufacturing the liquid cosmetic feeder according to claim 5, wherein the method of manufacturing the liquid cosmetic feeder further includes a process of opening a slide core in a process of the injection molding method.

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

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

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

11. The method of manufacturing the liquid cosmetic feeder according to claim 10, wherein a 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 manufacturing method according to any one of claims 5 to 11.

13. The 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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