US20140248074A1

US20140248074A1 - Liquid applicator

Info

Publication number: US20140248074A1
Application number: US14/171,270
Authority: US
Inventors: Masafumi Hamada
Original assignee: Mitsubishi Pencil Co Ltd
Current assignee: Mitsubishi Pencil Co Ltd
Priority date: 2013-02-06
Filing date: 2014-02-03
Publication date: 2014-09-04
Also published as: FR3001619A1; JP6145278B2; JP2014150863A

Abstract

A liquid applicator includes: a reservoir disposed in a barrel body and storing an application liquid such as a fluid cosmetic or the like; an application part fixed to a front end part of the barrel body by means of a joint and a front barrel so as to be put into contact with a target site to apply the application liquid to the site; and, a propelling mechanism disposed in the rear part of the barrel body to propel the application liquid from the reservoir to the application part, and wherein a delivery opening is formed in a front end of the application part and, at least, a surface of the application part around a deliver opening is formed of a high thermal conductivity material.

Description

This Nonprovisional application claims priority under 35 U.S.C. §119 (a) on Patent Application No. 2013-021170 filed in Japan on 6 Feb. 2013, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

(1) Field of the Invention
The present invention relates to an liquid applicator that includes: a reservoir disposed in a barrel and storing an application liquid such as a fluid cosmetic or the like; an application part fixed to the front end of the barrel to be put into contact with a target site and apply the application to the site, and a propelling mechanism disposed in the rear part of the barrel to propel the application liquid from the reservoir, and can apply the application liquid as sliding the application part over a target site such as the skin and the like.
(2) Description of the Prior Art
Generally, the applicators (liquid applicators) for applying an application liquid such as a liquid cosmetic are configured to be able to push the application liquid from the reservoir arranged in the barrel to the delivery port of the soft application part arranged at the front end of the barrel and apply the application liquid to a target site such as the skin or the like while sliding the application part over the target site.
As an example of the above liquid applicators having an application part made of silicone resin, a application part made of silicone rubber has been disclosed in Japanese Patent Application Laid-open 2006-158949 (Patent Document 1). Also, an application part made of urethane resin has been disclosed in International Publication WO2010-16572 (Patent Document 2).
However, in these technologies, the application parts are formed of soft materials, so that it is impossible to meet the demand for application with a firm and solid sensation.
In contrast to this, Japanese Patent Application Laid-open 2000-185779 (Patent Document 3) discloses an applicator having an application part with a metallic cover. Japanese Patent Application Laid-open 2009-39509 (Patent Document 4) discloses an applicator using a metal member as its application part in order to deal with a thermal process on the skin.
However, even with the applicator of the above Patent Document 3, the application part referred to as a cover is thin and elastic, so that it is impossible to apply the liquid firmly.
Further, though Patent Document 4 presents an applicator having a metallic application part, the delivery hole of the application liquid is formed from resin, so that no cool feeling intrinsic to metal can not be obtained upon application.

SUMMARY OF THE INVENTION

In view of the above problem, it is therefore an object of the present invention to provide an applicator that can produce a sensation intrinsic to a metallic member during application, implement firm application and present design peculiar to a metallic member.
The present invention resides in a liquid applicator comprising: a reservoir disposed in a barrel body and storing an application liquid such as a fluid cosmetic or the like; an application part fixed to a front end part of the barrel body by means of a joint and a front barrel so as to be put into contact with a target site to apply the application liquid to the site; and, a propelling mechanism disposed in a rear part of the barrel body to propel the application liquid from the reservoir to the application part, and wherein a delivery opening is formed in a front end of the application part and, at least, a surface of the application part around a deliver opening is formed of a high thermal conductivity material.
In the present invention, it is preferable that the application part is formed in the center of the front end part thereof, with a through-hole through which the application liquid is delivered.
In the present invention, it is preferable that the application part is spherical.
In the present invention, it is preferable that the high thermal conductivity material in the application part is metal, and the part is formed by press forming.
According to the above, use of pressing forming to form the application part can assure mass productivity without variation in accuracy. In particular, when press forming (punching) is implemented from the obverse side (the side in contact with the skin), the smooth or rounded side of the edge of holes appears on the obverse side while the rough edge forms on the interior side, so that it is possible to omit the post-processing such as deburring after machining.
In the present invention, it is preferred that, at least, the surface of the application part has a thermal conductivity of 1 W/m·K or greater.
According to the present invention, use of a high thermal conductivity material such metal or the like for the surface of the application part makes it possible to give a preferable application sensation such as “a pleasantly cool feeling” to the user upon application.
Further, use of metal not only can provide a firm application feeling but also can impart an attractive design peculiar to metal to the product. Of course, use of a high the same effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1E are illustrative diagrams of a liquid applicator using a metallic member as an application part according to the first embodiment of the present invention, FIG. 1A an overall vertical sectional view, FIG. 1B a side view with its cap vertically cut out, FIG. 1C a vertical sectional view of an application part according to a variational example of the first embodiment, FIG. 1D a front view of an application part, and FIG. 1E a vertical sectional view of an application part;

FIGS. 2A to 2E are illustrative diagrams of a liquid applicator according to the second embodiment, FIG. 2A an overall vertical sectional view, FIG. 2B a vertical sectional view of an application part of a variational example 2-1 of the second embodiment, FIG. 2C a vertical sectional view of an application part of a variational example 2-2 of the same, FIG. 2D a vertical sectional view of an application part of a variational example 2-3 of the same, and FIG. 2E a vertical sectional view of an application part of a variational example 2-4 of the same;

FIGS. 3A to 3E are illustrative diagrams of a liquid applicator according to the third embodiment, FIG. 3A an overall vertical sectional view, FIG. 3B a vertical sectional view of an application part of a variational example 3-1 of the third embodiment, FIG. 3C a front view of the application part of variational example 3-1, FIG. 3D a vertical sectional view of an application part of a variational example 3-2 of the same, and FIG. 3E a vertical sectional view of the application part of variational example 3-2;

FIG. 4 is an overall vertical sectional view of a liquid applicator according to the fourth embodiment and FIG. 4B is an overall vertical sectional view of a liquid applicator according to the fifth embodiment; and,

FIG. 5A is an overall vertical sectional view of a liquid applicator according to the sixth embodiment and FIG. 5B is an overall vertical sectional view of a liquid applicator having an application part according to the seventh embodiment as a modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the present invention will hereinafter be described in detail with reference to the drawings.
A liquid applicator according to the first embodiment will be described based on FIGS. 1A and 1B.
The liquid applicator of the first embodiment, as shown in FIGS. 1 and 1B, is constructed such that an application liquid such as a cosmetic for lips or cheeks is stored in a reservoir 12 arranged inside a barrel body 10, an application part 14 that is put into contact with a target site such as the skin of the user is fixed to a front end part 10 a of barrel body 10 by means of a front barrel 28 and a joint 30, and the application liquid stored in reservoir 12 of barrel body 10 is pushed toward application part 14 by means of a propelling mechanism 16 arranged in the rear part of barrel body 10, and delivered from delivery holes 14 a of the application part 14.
The application part 14 has delivery holes 14 a opened in the front end part, and at least, the periphery of delivery holes 14 a on the front face of application part 14, is formed of metal. In the embodiment, application part 14 provided in the front end of front barrel 28 is formed of a high thermal conductivity material of metal.
In further detail, the liquid applicator includes, as its essential components, application part 14 as an outer sleeve, barrel body 10, front barrel 28, joint 30 and propelling mechanism 16 and a cap 10 b.
In this liquid applicator of the embodiment, the application liquid such as a fluid cosmetic stored in reservoir 12 of the barrel body has a viscosity ranging from 0.3 Pa·sec to 50 Pa·sec at a shear rate of 5 sec⁻¹at 25 deg.C.
The propelling device 16 includes a piston body 18 that moves forward and backward with respect to reservoir 12 inside the barrel body 10 to reduce and increase the volume of the storage space, and a drive arrangement (including a rotary actuator 22, a shaft member (also called “screw rod”) 20, fixed sleeve and others) for moving the piston body 18 forward and backward by moving shaft member 20, which is disposed with its front end engaged with the rear end of the piston body 18, forward and backward, by user's operational force.

[Barrel Body 10]

Barrel body 10 has an approximately hollow cylindrical configuration with its front end part 10 a reduced in diameter. The outside diameter of the front end part 10 a is formed approximately equal to the inside diameter of cap 10 b. Cap 10 b is detachably fitted to the front end part 10 a. Rib-formed ridges and grooves are formed on the portions where front end part 10 a and cap 10 b oppose when these are set in place, to create a snap-fit joint so that cap 10 b will not come off from front end part 10 a by unintentional force. Preventing cap 10 b from coming of f from the barrel body due to unintentional force makes it possible to improve air-tightness and prevent evaporation of the application liquid from application part 14 and therearound.
Liquid-tightly fitted into the opening of front end part 10 a of barrel body 10 is the rear end part of the approximately cylindrical front barrel 28 with joint 30 disposed therein. The front end of this front barrel 28 has an opening, on which application part 14 is fixed to confine the opening. Further, the flange-shaped portion at the rear end of joint 30 is abutted against the rear end of front barrel 28 that is fitted into the bore of front end part 10 a of barrel body 10, so as to prevent front barrel 28 from coming off.
Arranged in the rear part of barrel body 10 is propelling mechanism 16. Piston body 18 of this propelling mechanism 16 is inserted from the rear end opening of barrel body 10, and is slidably disposed in tightly contact with the inner wall in the center part of the body. The space enclosed by the interior wall of barrel body 10, the rear end part of front body 28 and joint 30, and the front face of piston body 18 forms reservoir 12 of the application liquid. [Propelling Mechanism 16]
As shown in FIG. 1, in the liquid applicator of the embodiment, propelling mechanism 16 integrally assembled in the rear part of barrel body 10 is provided. Propelling mechanism 16 causes piston body 18 as its component to slide in liquid-tight contact with the inner wall in the central part of barrel body 10 by the user's operation, to thereby reduce and increase the volume of the reservoir 12 and pressurize and depressurize the application liquid.
Propelling mechanism 16 includes, as it main components, rotary actuator 22, shaft member 20, fixed sleeve 24 for taking the shaft member 20 in and out (these correspond to the drive arrangement) and the aforementioned piston body 18.
Rotary actuator 22 is formed of an outer sleeve cap 32 and an inner sleeve 26 that are jointed to each other in an unrotatable manner, and rotatory actuator 22 as a whole is arranged in a rotatable manner relative to barrel body 10. Shaft member 20 is arranged slidably in the axial direction, and fixed in the rotational direction, relative to this rotary actuator 22.

[Fixed Sleeve 24]

Fixed sleeve 24 is formed of an annular member and is attached to barrel body 10 unmovably in both the rotational and axial directions. The inner periphery of fixed sleeve 24 is formed with a female thread so as to mate with the male thread on the outer periphery of shaft member 20. As rotary actuator 22 is rotated, shaft member 20 rotates and moves axially thanks to the male thread of shaft member 20 mating with the female thread of fixed sleeve 24 so that piston body 18 moves forward and backward.
Further, the meshing portion, designated at 34 between fixed sleeve 24 and rotary actuator 22 (the outer peripheral side in the front part of inner sleeve 26) is formed with a ratchet structure. Rotary actuator 22 is rotatable in both directions relative to fixed sleeve 24 (barrel body 10 to which the sleeve is fixed). More specifically, when the rotary actuator is rotated in one direction that allows for delivery of the liquid cosmetic or the application liquid, this ratchet structure implements delivery of the liquid while causing the user to feel a clicking sensation on the fingers. When the rotary actuator is rotated in the other direction, the rotation is restrained.
As to restriction on rotation, if a torque limiter function for allowing rotation when a rotational force equal to or greater than a certain level is acted between outer sleeve cap 32 and inner sleeve 26 as the parts of rotary actuator 22 is added, it is possible to prevent the propelling mechanism from being broken. That is, if the application liquid is an antibacterial one such as a silicone oil-based liquid cosmetic for lips, provision of propelling mechanism 16 having a function of reducing the pressure of the application liquid inside reservoir 12 of barrel body 10 by rotating the rotary actuator 22 in the other direction, enables propelling mechanism 16 to reduce the pressure of the application liquid after the propelling mechanism 16 has stopped pressurizing the application liquid, hence draw back the application liquid from delivery holes 14 a of application part 14 into the application liquid conduit, designated at 30 a, inside joint 30.
On the other hand, if the application liquid is a water-based one which is prone to breed bacteria when the liquid touches the human skin or saliva, propelling mechanism 16 may and should be configured so that meshing portion 34 of the rotary actuator 22 is limited to rotate in the other direction and stops rotating, to thereby prohibit the application liquid from returning to reservoir 12.

[Rotary Actuator 22, Inner Sleeve 26]

Rotary actuator 22 is formed of outer sleeve cap 32 and inner sleeve (also called “propelling part”) 26 which are connected to be unrotatable to each other under normal condition and become rotatable when a certain rotational force or greater is applied, and rotary actuator 22 as a whole is arranged rotatably in the rear part of barrel body 10.

[Front Barrel 28, Joint 30]

As shown in FIG. 1, front barrel 28 is an approximately hollow cylinder having a front endface, cut obliquely relative to the axis, and formed with a small-diametric opening 28 a near the center thereof and a large-diametric rear part with its rear end open. The rear part of front barrel 28 is air-tightly fitted into front end part 10 a of barrel body 10. Application part 14 is fitted into opening 28 a at the front end of front barrel 28.
As shown in FIG. 1, the joint 30 is an approximately hollow cylinder having application liquid conduit 30 a with its outer peripheral side of the front and rear parts are fitted inside front barrel 28. Application liquid conduit 30 a is adapted to have an optimal diameter by taking into account the fluid resistance depending on the viscosity of the application liquid and other factors.
Detailedly, joint 30 has an approximately cylindrical configuration as whole constructed such that the rear part is made greater stepwise in diameter than the front part and that application liquid conduit 30 a having an approximately the same diameter forming an interior hollow that penetrates through the inside from the front part to the rear part in the axial direction is provided from the front to the middle part. A plurality of rib-like or semicylindrical annular projections are formed on the outer peripheral side of the rear large-diametric part of joint 30 and inserted into the front barrel. A flanged portion is formed in the rear end of joint 30 and abutted against the rear end of front barrel 28.
Here, as to the material of each component in the embodiment, shaft member 20 and fixed sleeve 24 can be formed of ABS resin, piston body 18 and front barrel 28 can be formed of HDPE (high density polyethylene), and barrel body 10, cap 10 b and external sleeve cap 32 can be formed of PP (polypropylene). For each component, other kind of resin may be used as appropriate. Fixed sleeve 24 may be made of PC (polycarbonate) resin, or POM (polyacetal) resin.

[Application Part 14]

As shown in FIGS. 1A and 1B, the application part 14 is a punch-formed metallic flat plate of an approximately circular shape with a plurality of delivery holes 14 a formed therein. The circumference is rounded so that the application part assumes a dish-like configuration.
Specifically, the liquid applicator of the first embodiment is an applicator for delivering liquid stain for lips and cheeks as an application liquid, and is attached with application part 14 which is made of metal or the like having a high thermal conductivity, has been formed by boring delivery holes 14 a by metal etching and pressed into a dish-like form with its periphery rounded, as shown in FIGS. 1D and 1E. Alternatively, the application part may be formed by boring delivery holes 14 a by punch press forming, bending the periphery and punching out the circumference by progressive die or simple die.
A suitable clearance 14 b is formed between the front end of joint 30 of the inner sleeve (hole) of front barrel 28 and the inner surface of application part 14 (metal member) so that the liquid can be ejected from all the delivery holes 14 a formed in application part 14.
Application part 14 of a high thermal conductivity material, preferably uses high thermal conductivity materials having a thermal conductivity of 1 or higher such as stainless steel, glass, aluminum, duralumin and carbon steel. Among these, stainless steel, which does not need surface treatment such as plating and the like, is most preferable because the application part would contact with the liquid and the skin.
Further, if the edges of delivery holes 14 a in application part 14 are burred, there is a risk of the skin and others being injured upon contact with the application part, it is preferable to polish the application part. This polishing may be preferably done by electrolyte polishing.
As to the surface of application part 14 of the present embodiment, the shape and size of each hole and the layout of multiple holes are not particularly specified. For example, the holes may be arranged like a cinquefoil having a slightly greater center hole with smaller holes therearound.
Further, the metal member of application part 14 may be projected from the front barrel base (which is assumed to be made of resin) so as to directly contact the skin (lips), whereby the user can feel comfortable on the skin (lips) and spread the liquid easily. Instead of a flat plane, the metal member may be formed with curvature by press-forming or other methods.
The plate thickness of application part 14 may be 0.1 mm to 1.0 mm, and more preferably 0.15 mm to 0.3 mm. With a thickness less than 0.15 mm, application part 14 is felt flexed upon application, whereas with a thickness of 1.0 mm or greater, it is difficult to shape the plate and control the size (pitch) of the holes.
It is also possible to form application part 14 integrally with front barrel 28 by insert molding.
Alternatively, it is possible to fix the application part metallic member by holding it with front barrel 28 and joint 30.
The present invention should not be limited to the above first embodiment, various variations can be implemented.
Though in the first embodiment, joint 30 of the liquid applicator fills up the interior of front barrel 28 as shown in FIG. 1A, it is possible to create a space from front barrel 28 by using multiple parts in combination as in a variational example shown in FIG. 1C. Application part 14 is formed of divided parts, and an inner tube for leading the application liquid to right below the metal member is provided. This inner tube is coupled with joint 30. The joint 30 of this variational example is composed of multiple parts, i.e., two approximately cup-like front and rear end parts formed with a hollow tube in the axial center thereof and a tube arranged in the middle part that connects between the front end part and the rear end part.
Next, the liquid applicator of the second embodiment will be described with reference to FIG. 2.
As shown in FIG. 2, the liquid applicator of the second embodiment is an applicator having a spherical application part 14 formed in the center thereof with a through-hole for supplying the application liquid. Application part 14 is formed of a high thermal conductivity material similar to the first embodiment. The configurations of propelling mechanism 16 and other components are the same as those of the liquid applicator of the first embodiment with the same reference numerals allotted.
Detailedly, as shown in FIG. 2A, the rear part of joint 30 is large in diameter, forming a cylindrical member 30 c, from which a tubular member 30 d is extended forward. The front end of tubular member 30 d is inserted into, and joined to, through-hole of application part 14, so that application part 14 is fixed to joint 30.
Tubular member 30 d is preferably formed of stainless steel as the spherical part is.
As to the dimensions of tubular member 30 d, the wall thickness is preferably 0.05 to 0.5 mm, more preferably 0.1 to 0.3 mm because the member needs to support the spherical part.
The inside diameter of tubular member 30 d is preferably 0.5 to 3 mm, in consideration of fluid resistance depending on the viscosity of the application liquid.
Since application part 14 is a metallic sphere, it is possible to give a cool feeling when the applicator is used and applied on a target site such as the skin while producing a smooth sensation when moved.
In the second embodiment, various variations can be configured as in variational examples 2-1 to 2-4 shown in FIGS. 2B to 2E.
In variational example 2-1 shown in FIG. 2B, an annular pressing rib 10 c is projected in cap 10 b so that the pressing rib 10 c hermetically encloses delivery hole 14 a at the front end of application part 14. With this, it is possible to enhance air-tightness.
In variational example 2-2 shown in FIG. 2C, the rear end of tubular member 30 d of joint 30 is enlarged in diameter like a flange so as to prevent the tubular member from coming off from cynical member 30 c.
In variational example 2-3 shown in FIG. 2D, the front end of front barrel 28 is beveled so that the front end can come into close contact with rear end face of application part 14.
In variational example 2-4 shown in FIG. 2E, the front end face of application part 14 around delivery hole 14 a is formed with a flat plane 14 a 1.
Next, the liquid applicator of the third embodiment will be described with reference to FIG. 3. As to the structures of propelling mechanism 16 and others, the same components as in the first embodiment are allotted with the same reference numerals.
As shown in FIG. 3A, the liquid applicator of the third embodiment is an applicator having a spherical application part 14 formed in the center thereof with a through-hole (delivery hole 14 a) for supplying the application liquid. Application part 14 is formed of a high thermal conductivity material similar to the first embodiment.
Joint 30 is formed of a tapering cylindrical member 30 c being covered by front barrel 28, fitted in front end part 10 a of barrel body 10, and a tubular member 30 d extended forward from front barrel 28 so that application part 14 is disposed at the front end of the tubular member 30 d.
In this third embodiment, since application part 14 is arranged at the front end of long tubular member 30 d, the flexion of tubular member 30 d can improve application feeling, and it is possible to apply the liquid at a site where the user's hand cannot reach, so that this configuration is convenient for use.
In this third embodiment, as shown in FIG. 3A, pressing ribs 10 c are provided in the bore of cap 10 b at the position where application part 14 is located. This prevents application part 14 from slipping off due to inertial force when the applicator falls with application part 14 down. Pressing ribs 10 c are disposed so that when the cap is set in place the ribs are positioned in contact with, or leaving slight clearance from, (the front end part of) application part 14. Specifically, pressing rib 10 is a plate-like piece extended rearward inside the front end part of cap 10 b, and a plurality of pressing ribs are provided circumferentially apart from one another.
In the third embodiment, various modifications can be implemented. In variational example 3-1 shown in FIGS. 3B and 3C, the front end face around delivery hole 14 a of application part 14 and the rear end face into which tubular member 30 d is inserted are formed with flat plane 14 a 1. In variational example 3-2 shown in FIGS. 3D and 3E, the front end face and rear end face of the application part 14 are formed spherically. In this way, the sphere of application part 14 can be formed in various shapes.
Next, the liquid applicators of the fourth and fifth embodiments will be described with reference to FIG. 4. As to structures of propelling mechanism 16 and others, the same components as in the first embodiment are allotted with the same reference numerals.
As shown in FIG. 4A, the liquid applicator of the fourth embodiment is an applicator having a spherical application part 14 formed in the center thereof with a through-hole (delivery hole 14 a) for supplying the application liquid, and a brush 36 arranged in the through-hole. Application part 14 is formed of a high thermal conductivity material similar to the first embodiment.
The liquid applicator of the fifth embodiment is, as shown in FIG. 4B, an applicator having a plurality of spherical application parts 14, penetrated on tubular member 30 d. Application part 14 is formed of a high thermal conductivity material similar to the first embodiment.
Next, the liquid applicators of the sixth and seventh embodiments will be described with reference to FIGS. 5A and 5B. As to the structures of propelling mechanism 16 and others, the same components as in the first embodiment and the same components as in the fifth embodiment are allotted with the same reference numerals.
As shown in FIG. 5A, the liquid applicator of the sixth embodiment is an applicator having a plurality of spherical application parts 14 that are penetrated on tubular member 30 d. Each spherical application part 14 is put in direct contact with other while an annular space 38 made of elastic material such as rubber is disposed between the sides of application parts 14. Annular spacer 38 has an axially short tubular configuration, arranged along tubular member 30 d. With this arrangement, it is possible to improve attachment stability of spherical application parts 14.
As shown in FIG. 5B, the liquid applicator of the seventh embodiment is an applicator having a plurality of spherical application parts 14 that are penetrated on tubular member 30 d and spacers 38 made of elastic material disposed between application parts 14. The spacer 38 in this case has a flat disk form with a hollow through which tubular member 30 d is penetrated, and is interposed between application parts 14 so that application parts 14 are floated without directly touching each other. When cap 10 b is attached, spacers 38 elastically compressed and deformed by the pressure via application parts 14 from the cap 10 b.
According to the seventh embodiment, it is possible to improve the applicator in design and adjust the fitting condition of cap 10 b when viscoelastic material such as rubber, elastomer or the like is selected for spacers 38. Alternatively, when metal or resin is selected for spacers 38 and the spacers are attached marginally apart from application parts 14, the applicator can be used as the spheres smoothly rotate.
Though the above embodiments have been described by giving examples in which a twist-feed mechanism is used as the propelling mechanism, the present invention can adopt any other mechanism such as clicking types, tube types and other types as long as a cosmetic fluid or any other application liquid can be delivered.
The liquid applicator of the present invention can also be used for applicators for medicines in addition to cosmetics such as fluid cosmetics.

Claims

What is claimed is:

1. A liquid applicator comprising:

a reservoir disposed in a barrel body and storing an application liquid such as a fluid cosmetic;

an application part fixed to a front end part of the barrel body by means of a joint and a front barrel so as to be put into contact with a target site to apply the application liquid to the site; and,

a propelling mechanism disposed in the rear part of the barrel body to propel the application liquid from the reservoir to the application part, and

wherein a delivery opening is formed in a front end of the application part and, at least, a surface of the application part around a deliver opening is formed of a high thermal conductivity material.

2. The liquid applicator according to claim 1, wherein the application part is formed in a center of the front end part thereof, with a through-hole through which the application liquid is delivered.

3. The liquid applicator according to claim 1, wherein the application part is spherical.

4. The liquid applicator according to claim 2, wherein the application part includes a metallic part machined by press-forming.

5. The liquid applicator according to claim 1, wherein, at least, the surface of the application part has a thermal conductivity of 1 W/m·K or greater.