JP7663362B2 - Pen tip, intermediate core, and liquid applicator equipped with said pen tip or intermediate core - Google Patents

Description

The present invention relates to a pen tip and a core used in a liquid applicator such as a writing instrument or a cosmetic tool, and a liquid applicator equipped with the pen tip or core.

Fiber pen tips or intermediate cores used in writing instruments and liquid applicators for cosmetic tools are made by bundling fibers in the longitudinal direction and bonding them with a resin binder, and then shaping the front and rear ends into the desired shape by grinding, etc. Alternatively, two or more types of fibers with different melting points are mixed in large quantities, aligned in the longitudinal direction, bundled and compressed, and bonded by thermal fusion between the fibers.
Here, the pen tip of the present invention is used to write and apply liquid supplied from the rear end portion to a target such as paper or skin at the tip.
The intermediate core has a rear end portion immersed in the contained liquid, and supplies a constant amount of the liquid to the application pen tip by the capillary force of the intermediate core.

Conventional fiber pen tips and intermediate cores are made of fibers of approximately the same diameter, and the width of the flow passage between the fibers through which liquid passes is approximately the same throughout the entire pen tip or intermediate core.
However, when the diameter of the fibers is small and the width of the flow path between the fibers through which the liquid passes is small, although the capillary force and liquid retention are increased, there is a problem that clogging is likely to occur in the pen tip or intermediate core depending on the composition of the liquid. In particular, when the liquid in the liquid applicator contains particles such as glitter or pearl pigments, the particles cause significant clogging in the pen tip or intermediate core due to the filtering effect, and such clogging causes a significant decrease in the permeability of liquid other than the particles.
On the other hand, if the diameter of the fibers is increased to increase the width of the flow path between the fibers through which the liquid passes in order to improve liquid permeability, the capillary force and liquid retention force are weakened, and when the liquid applicator is held upright, a phenomenon in which the liquid or particles contained in the liquid return to the liquid storage section (drain back) occurs, and when the liquid applicator is held downright, liquid leakage (ink dripping) occurs, resulting in the problem that stable application and storage are not possible.

In recent years, a writing body has been disclosed that can smoothly supply pigmented ink to a coating surface and has little ink run-off when the applicator is inverted (Patent Document 1). The solution is to configure the writing body with fibers located in the center having a larger diameter than the fibers located in the outer periphery.
However, in the case of the writing body configuration disclosed in Patent Document 1, the flow of the pigmented ink is good at the beginning of application, but after a certain time has passed with the pen tip facing upward, the inventors have confirmed in their tests that, although the pigmented ink is held in the outer periphery where the fiber diameter is small and the flow path width between the fibers through which the liquid passes is small, the pigmented ink returns to the liquid storage section in the center where the fiber diameter is large and the flow path width between the fibers through which the liquid passes is large (drain back). In other words, there was a problem that the particles such as glitter and pearl pigments and liquid did not flow smoothly in the center part of the tip of the writing body, which is the normal writing part, and writing was required to be done at an inclined writing angle to the outer periphery where the particles such as glitter and pearl pigments and some of the liquid were held.
Furthermore, the center of the pen tip, which comes into contact with the surface of the object during normal application (writing), is made of thick fibers, which increases the resistance when writing and creates a rough feeling. This results in a poor writing feel, and is prone to damaging the paper or skin surface, and when the object is skin, it causes pain.

JP 2011-255638 A

The present invention has been made in consideration of the above circumstances, and aims to provide a pen tip or intermediate core that has both liquid permeability and capillary force (liquid retention), thereby suppressing the drain back phenomenon in the center of the tip of the pen tip that comes into contact with the surface of the object being coated during coating (writing), and enabling stable coating (writing).

In order to solve the above problems, the nib of the present invention is a nib formed into a desired shape after fibers are bundled in the longitudinal direction and bonded with a resin binder, or a nib formed by mixing two or more types of fibers with different melting points in large numbers, aligning them in the longitudinal direction, bundling and compressing them, and bonding them by thermal fusion between the fibers, and is characterized in that the cross section of the nib has a nib first layer provided at the center of the cross section and a nib second layer provided adjacent to the outside of the nib first layer, and the flow path width between the fibers in the nib first layer, through which liquid passes, is smaller than the flow path width between the fibers in the nib second layer, through which liquid passes.

The cross section of the first pen tip layer is generally circular, the cross section of the second pen tip layer is generally doughnut-shaped, and the cross section of the first pen tip layer is preferably 1/36 to 9 times the cross section of the second pen tip layer.

It is preferable that the single yarn of the fiber of the first layer of the pen tip is 0.3 dtx to 7.7 dtx, and the single yarn of the fiber of the second layer of the pen tip is 5.5 dtx to 22 dtx.

The fibers may be polyamide fibers, polyester fibers, or acrylic fibers.

The resin binder may be a polyurethane resin, a phenoxy resin, an epoxy resin, or a melamine resin, and the liquid may contain particles.

The relay core of the present invention is a relay core formed into a desired shape after fibers are bundled in the longitudinal direction and bonded with a resin binder, or a relay core formed by mixing two or more types of fibers with different melting points in large quantities, aligning them in the longitudinal direction, bundling and compressing them, and bonding them by thermal fusion between the fibers. The cross section of the relay core has a first relay core layer provided at the center of the cross section and a second relay core layer provided adjacent to the outside of the first relay core layer, and the width of the flow path between the fibers through which liquid passes in the first relay core layer is smaller than the width of the flow path between the fibers through which liquid passes in the second relay core layer.

It is preferable that the cross section of the first relay core layer is substantially circular, the cross section of the second relay core layer is substantially doughnut-shaped, and the cross section of the first relay core layer is 1/36 to 9 times the cross section of the second relay core layer.

It is preferable that the single yarn of the fiber of the first layer of the relay core is 0.3 dtx to 7.7 dtx, and the single yarn of the fiber of the second layer of the relay core is 5.5 dtx to 22 dtx.

The fibers may be polyamide fibers, polyester fibers, or acrylic fibers.

The resin binder may be a polyurethane resin, a phenoxy resin, an epoxy resin, or a melamine resin, and the liquid may contain particles.

The liquid applicator of the present invention is equipped with the pen tip or the intermediate core.

The pen tip of the present invention has both liquid permeability and capillary force (liquid retention), and when held upright, it is possible to suppress the phenomenon of liquid draining back at the center of the tip that comes into contact with the surface of the object being coated during coating. In other words, it is possible to allow the necessary amount of liquid to flow out during coating (writing), making stable coating (writing) possible.
The intermediate core of the present invention has both liquid permeability and capillary force (liquid retention), and when held upright, it is possible to prevent the liquid that should be supplied to the center of the tip of the application pen tip from draining back into the liquid storage section through the intermediate core. In other words, the necessary amount of liquid can be discharged during application (writing), allowing for stable application (writing).

1 shows an example of a cross section of a pen tip. 1 shows an example of a cross section of a relay core. 3(a) and 3(b) show examples of vertical cross sections of a liquid applicator equipped with a pen tip. 4(a) and 4(b) show examples of vertical cross sections of a liquid applicator equipped with a relay core. FIG. 5(a) shows an SEM image of the cross section of the pen tip, and FIG. 5(b) shows an enlarged SEM image of FIG. 5(a). FIG. 6(a) shows a conceptual diagram of the movement of particles in liquid when the pen tip is facing downward, and FIG. 6(b) shows a conceptual diagram of the movement of particles in liquid when the pen tip is facing upward. FIG. 7(a) shows a conceptual diagram of the movement of particles in liquid when the relay core is facing downward, and FIG. 7(b) shows a conceptual diagram of the movement of particles in liquid when the relay core is facing upward. An overview of particle size distribution measurement in liquid is shown below.

The following describes a form for implementing the present invention using Figures 1 to 8.

(Pen tip)
As shown in Figures 3(a) and 3(b), the pen tip 2 of the present invention writes and applies liquid 4, which is supplied directly from the rear end portion of the pen tip 2 or via a relay core 30 or the like, to a target object such as paper or skin at the tip of the pen tip 2.
The pen tip 2 is made by gathering fibers in the longitudinal direction, passing them through a molding die for thermal processing, impregnating and drying the fibers with a resin binder, bonding them together, and then grinding them into the desired length and shape. Alternatively, two or more types of fibers with different melting points are mixed in large quantities, aligned in the longitudinal direction, bundled and compressed, and bonded by thermal fusion between the fibers in a state in which continuous pores exist between the fibers. Such bonding means that when fibers with different melting points are thermally melted at a temperature between the melting points, the fibers with a lower melting point melt and the fibers with a higher melting point do not melt, so that the fibers with the higher melting point bond to part of the outer periphery of the fibers with the lower melting point.
The relay core 30 is preferably a thermoplastic resin molded into a required cross-sectional shape and dimensions by melt extrusion molding, and examples thereof include a synthetic fiber bundle such as acrylic fiber, polyester fiber, or nylon fiber solidified with urethane resin. Examples of the relay core 30 include a thermoplastic product such as a polyolefin foam having a three-dimensional mesh structure with interconnected continuous pores and having shape retention and moderate flexibility, and a sintering method in which each granular particle made of thermoplastic resin is partially fused to each other and forms interconnected continuous pores between each granular particle. The relay core 30 may be a single layer, or may have a first relay core layer and a second relay core layer, as in the relay core of the present invention.

(Liquid Composition)
The liquid 4 supplied to the pen tip 2 is to be applied to a target such as paper or skin, and is appropriately blended depending on the purpose and application. The viscosity of the liquid 4 is, for example, 3 cps to 60 cps.
The liquid 4 may contain particles 4a such as glitter or pearl pigments. The material and size of the particles 4a are appropriately selected depending on the purpose and application. The particle size is, for example, in the range of 1 μm to 500 μm, preferably 5 μm to 300 μm, and more preferably 10 μm to 200 μm.

(Pen tip fiber material)
Synthetic fibers or the like are used for the fibers of the pen tip 2. Examples of synthetic fibers include polyamide fibers such as nylon (registered trademark), polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, and acrylic fibers.

(Pen tip structure)
As shown in FIG. 1, the cross section of the pen tip 2 has a pen tip first layer 2a provided at the center of the cross section, and a pen tip second layer 2b provided adjacent to the outside of the pen tip first layer 2a.
The width of the flow passage between the fibers in the first pen tip layer 2a through which the liquid passes is adjusted to be smaller than the width of the flow passage between the fibers in the second pen tip layer 2b through which the liquid passes.

The width of the flow passage between the fibers is adjusted by the diameter (thickness) of the fibers, and is adjusted by the amount (number) of fibers as necessary to adjust the permeability of the liquid.
The diameter (thickness) of the fibers in the first pen tip layer 2a is, for example, in the range of 0.3 dtex to 7.7 dtex, and more preferably in the range of 1.1 dtex to 5.5 dtex.
As shown in Figure 6 (b), when the pen tip 2 is pointed upward, in order to prevent the liquid 4 and particles 4a contained in the liquid 4 once supplied to the tip portion of the pen tip first layer 2a (the pen tip-subject contact portion 2c) from draining back into the liquid storage portion 5, it is desirable to adjust the diameter of the fibers of the pen tip first layer 2a to 7.7 dtex or less, although this depends on the material and area ratio of the fibers of the pen tip first layer 2a and the pen tip second layer 2b, the diameter of the pen tip, the materials of the liquid 4 and the particles 4a, etc.
In order to ensure the permeability of the liquid 4, it is desirable to adjust the fiber diameter of the first pen tip layer 2a to 0.3 dtex or more.

On the other hand, the diameter (thickness) of the fibers in the second pen tip layer 2b is, for example, in the range of 5.5 dtex to 22 dtex, preferably 8.8 dtex to 22 dtex, and more preferably 9.9 dtex to 16.5 dtex.
As shown in Figure 6 (a), when the pen tip 2 is pointed downward, the liquid 4 (especially when the viscosity is high) and the particles 4a contained in the liquid 4 use the wide flow path in the pen tip second layer 2b to flow out and penetrate into the tip portion of the pen tip 2 (tip-subject contact portion 2c). Although this depends on the material and area ratio of the fibers in the pen tip first layer 2a and the pen tip second layer 2b, the diameter of the pen tip, the materials of the liquid 4 and the particles 4a, etc., it is desirable to adjust the diameter of the fibers in the pen tip second layer 2b to 5.5 dtex or more.
In addition, it is preferable that the fiber diameter of the pen tip second layer 2b is adjusted to 22 dtex or less so that the liquid 4 does not drip and cause a liquid leakage phenomenon when the pen tip 2 is pointed downward.
In addition, in order to make the flow path width between the fibers in the first pen tip layer 2a, through which liquid passes, smaller than the flow path width between the fibers in the second pen tip layer 2b, the diameter (thickness) of the fibers in the first pen tip layer 2a is set smaller than the diameter (thickness) of the fibers in the second pen tip layer 2b.

(Pen tip first layer and pen tip second layer)
As shown in Figures 1 and 5, the cross section of the pen tip 2 has a pen tip first layer 2a provided at the center of the cross section, and a pen tip second layer 2b provided adjacent to the outside of the pen tip first layer 2a.
The shape of the cross section of the pen tip first layer 2a can be freely selected as long as it is located at the center of the cross section of the pen tip 2. For example, it may be a circle, an ellipse, a square, a rectangle, a diamond, a star, etc., but a substantially circular shape is more preferable.
The cross section of the pen tip second layer 2b may be adjacent to the outside of the pen tip first layer 2a, with the inside being in contact with and adjacent to the outer circumferential surface of the pen tip first layer 2a in the same shape, and the outside being freely selected in shape depending on the use and purpose of the liquid applicator 1. For example, it may be circular, elliptical, square, rectangular, etc. When the pen tip first layer 2a is approximately circular, the pen tip second layer 2b may be approximately donut-shaped (the outer periphery of the pen tip second layer 2b is circular).

As shown in FIG. 6A, when the pen tip 2 is facing downward, the flow path width between the fibers of the pen tip second layer 2b is larger than the flow path width between the fibers of the pen tip first layer 2a, so the liquid 4 (especially when the viscosity is high) supplied from the rear end portion of the pen tip 2 and the particles 4a contained in the liquid 4 are more likely to flow through the flow path of the pen tip second layer 2b than through the pen tip first layer 2a. Here, since the pen tip second layer 2b is arranged in contact with and adjacent to the pen tip first layer 2a, while the liquid 4 and the particles 4a contained in the liquid 4 flow from the liquid storage portion 5 to the pen tip-subject contact portion 2c, which is the tip portion of the pen tip 2, a part of the particles 4a in particular also migrates to the pen tip first layer 2a, and the liquid 4 and the particles 4a contained in the liquid 4 reach the center portion (pen tip-subject contact portion 2c) of the tip of the pen tip 2, and the liquid 4 and the particles 4a contained in the liquid 4 that have reached therein are used for writing and application. At this time, the liquid 4 and particles 4a that have flowed through the pen tip second layer 2b to the tip portion are held by the capillary force of the pen tip first layer 2a, thereby preventing liquid leakage from the pen tip.
6(b), when the pen tip 2 is pointed upward, some of the liquid 4 and particles 4a flow through the flow path of the pen tip second layer 2b and drain back toward the liquid storage section 5. At this time, the liquid 4 and particles 4a that have migrated to the pen tip first layer 2a are held as they are in the center of the tip of the pen tip 2 (near the pen tip-subject contact portion 2c) by capillary force.
When the pen tip 2 is turned downward again and writing or application is started, the liquid 4 or particles 4a that have been held in the tip portion of the pen tip 2 (near the pen tip-subject contact portion 2c) by the capillary force of the pen tip first layer 2a without being drained back can be used immediately for writing or application. Therefore, it is possible to smoothly apply the liquid without having to wait for the liquid 4 or particles 4a to be supplied to the pen tip 2 from the liquid storage portion 5.

The cross-sectional diameter of the first pen tip layer 2a and the layer thickness of the second pen tip layer 2b, i.e., the cross-sectional area, are adjusted so that mechanisms such as the flow of liquid 4 and particles 4a, migration between layers, drain back in the second pen tip layer 2b, retention by capillary force in the first pen tip layer 2a, and suppression of liquid leakage can be achieved.
As shown in Fig. 1 and Fig. 5, when the cross section of the pen tip first layer 2a is substantially circular and the cross section of the pen tip second layer 2b is substantially doughnut-shaped, the radius r of the cross section of the pen tip first layer 2a is desirably set in the range of 1/5.1 to 18.5 times r/d with respect to the layer thickness d of the pen tip second layer 2b. That is, the cross-sectional area of the pen tip first layer 2a is desirably set in the range of 1/36 to 9 times with respect to the cross-sectional area of the pen tip second layer 2b. The cross-sectional area of the pen tip first layer 2a is desirably set in the range of preferably 1/20 to 9 times, more preferably 1/15 to 9 times, or 1/9 to 9 times, 1/8 to 9 times, 1/7 to 9 times, 1/6 to 9 times, 1/5 to 9 times, or 1/4 to 9 times with respect to the cross-sectional area of the pen tip second layer 2b. In addition, the upper limit of each is preferably 9 times, more preferably 8 times, and even more preferably 5 times. If the area ratio is smaller than 1/36, the amount of liquid 4 or particles 4a that drains back when the pen tip 2 is facing upward increases, and the amount of liquid held by the capillary force of the pen tip first layer 2a decreases when the pen tip 2 is facing downward. Also, if the area ratio exceeds 9, the flow paths of the pen tip second layer 2b are insufficient for the flow rate of the liquid 4 or particles 4a centered on the pen tip second layer 2b, and clogging is likely to occur due to the liquid 4 or particles 4a that try to migrate and flow into the adjacent pen tip first layer 2a, which has a stronger capillary force.
The optimal range of r/d, i.e., the optimal range of the area ratio, varies depending on the diameter of the fibers of the first nib layer 2a and the second nib layer 2b, the type of fiber, the type and viscosity of the liquid 4, the type and size of the particles 4a, the use of the nib, etc., and is therefore adjusted as appropriate.

(Resin binder)
The resin binder of the pen tip 2 may be polyurethane resin, phenoxy resin, epoxy resin, melamine resin, or the like.

(Relay core)
As shown in Figures 4(a) and 4(b), the relay core 3 of the present invention has a rear end portion immersed in the contained liquid 40, and supplies a constant amount of the liquid 40 to the application pen tip 20 by the capillary force of the relay core 3.
The intermediate core 3 is made by gathering fibers in the longitudinal direction, passing them through a molding die for thermal processing, impregnating and drying the fibers with a resin binder, bonding the fibers together, and then grinding the fibers to the desired length and shape. Alternatively, the intermediate core 3 is made by mixing two or more types of fibers with different melting points in large quantities, bundling and compressing the fibers in the longitudinal direction, and bonding the fibers together by thermal fusion in a state in which continuous pores are formed between the fibers. Such bonding is achieved by thermally melting fibers with different melting points at a temperature between the melting points, where the fibers with a lower melting point melt and the fibers with a higher melting point do not melt, so that the fibers with the higher melting point bond to part of the outer periphery of the fibers with the lower melting point.

(Application pen tip)
The application pen tip 20 applies the liquid 40 or particles 40a contained in the liquid 40 supplied from the tip portion of the intermediate core 3 to a surface to be applied, such as paper or skin. The tip portion of the intermediate core 3 is inserted into the inside from the rear end portion of the application pen tip 20, for example, to bring them into contact and connect, and the liquid 40 or particles 40a contained in the liquid 40 flowing out from the tip portion of the intermediate core 3 is applied by the application pen tip 20.
Examples of the application pen tip 20 include those made of bundles of thread material made of synthetic resin material such as polybutylene terephthalate (PBT), those made by solidifying bundles of synthetic fibers such as acrylic fibers, polyester fibers, and nylon fibers using urethane resin or the like, those made of PBT (polybutylene terephthalate) tapered filaments or nylon tapered filaments with tapered tips, those made of thermoplastic products such as polyolefin foams that have a three-dimensional mesh structure with interconnected continuous pores and have shape retention and appropriate flexibility, those formed by a sintering method in which granular particles made of thermoplastic resin are partially fused to each other and form interconnected continuous pores between the granular particles, and porous bodies formed by melt extrusion molding of thermoplastic resin into the required cross-sectional shape and dimensions.
The shape of the applicator pen tip 20 is appropriately selected depending on the purpose and use, and examples include shapes used for oil-based markers, water-based markers, board markers, line markers, paint markers, correction pens, writing liquid applicators for medical markers, medicinal liquid applicators, eyeliner, eyeshadow, eyebrows, lip liner, lip gloss, concealer, nail care products, eyelash care products, cosmetic liquid applicators such as nail polish brushes, etc.

(Liquid Composition)
The liquid 40 supplied from the intermediate core 3 to the application pen tip 20 is applied to a target such as paper or skin, and is appropriately blended depending on the purpose and application. The viscosity of the liquid 40 is, for example, 3 cps to 60 cps.
The liquid 40 may contain particles 40a such as glitter or pearl pigments. The material and size of the particles 40a are appropriately selected depending on the purpose and application. The size of the particles is, for example, in the range of 1 μm to 500 μm, preferably 5 μm to 300 μm, and more preferably 10 μm to 200 μm.

(Material of fiber for intermediate core)
Synthetic fibers or the like are used as the fibers of the relay core 3. Examples of synthetic fibers include polyamide fibers such as nylon (registered trademark), polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, and acrylic fibers.

(Structure of relay core)
As shown in FIG. 2, the cross section of the relay core 3 has a relay core first layer 3a provided at the center of the cross section, and a relay core second layer 3b provided adjacent to the outside of the relay core first layer 3a.
The width of the flow passage between the fibers in the first relay core layer 3a through which the liquid passes is adjusted to be smaller than the width of the flow passage between the fibers in the second relay core layer 3b through which the liquid passes.

The width of the flow passage between the fibers is adjusted by the diameter (thickness) of the fibers, and is adjusted by the amount (number) of fibers as necessary to adjust the permeability of the liquid.
The diameter (thickness) of the fibers in the first relay core layer 3a of the relay core 3 is, for example, in the range of 0.3 dtex to 7.7 dtex, and more preferably in the range of 1.1 dtex to 5.5 dtex.
As shown in Figure 7 (b), when the relay core 3 is turned upward, in order to prevent the liquid 40 and particles 40a contained in the liquid 40 that have been supplied to the tip portion of the relay core first layer 3a (relay core-applicator pen tip contact portion 3c) from draining back into the liquid storage portion 5, it is desirable to adjust the fiber diameter of the relay core first layer 3a to 7.7 dtex or less, although this will depend on the fiber materials and area ratios of the relay core first layer 3a and relay core second layer 3b, the relay core diameter, the materials of the liquid 40 and the particles 40a, etc.
In order to ensure the permeability of the liquid 40, it is preferable that the fiber diameter of the first relay core layer 3a is adjusted to 0.3 dtex or more.

On the other hand, the diameter (thickness) of the fibers in the second relay core layer 3b of the relay core 3 is, for example, in the range of 5.5 dtex to 22 dtex, preferably 8.8 dtex to 22 dtex, and more preferably 9.9 dtex to 16.5 dtex.
As shown in Figure 7(a), when the relay core 3 is held down, the liquid 40 (particularly when the viscosity is high) and the particles 40a contained in the liquid 40 use the wide flow path in the relay core second layer 3b to flow out and permeate into the tip portion of the relay core 3 (relay core-applicator pen tip contact portion 3c). Although this depends on the fiber materials and area ratios of the relay core first layer 3a and relay core second layer 3b, the relay core diameter, and the materials of the liquid 40 and particles 40a, etc., it is desirable to adjust the fiber diameter of the relay core second layer 3b to 5.5 dtex or more.
In addition, it is desirable to adjust the fiber diameter of the second layer 2b of the relay core to 22 dtex or less so that the liquid 40 does not drip and leak from the application pen tip 20 when the relay core 3 is held down.
In order to make the flow path width between the fibers in the first relay core layer 3a, through which the liquid passes, smaller than the flow path width between the fibers in the second relay core layer 3b, the diameter (thickness) of the fibers in the first relay core layer 3a is set smaller than the diameter (thickness) of the fibers in the second relay core layer 3b.

(First relay core layer and second relay core layer)
As shown in FIG. 2, the cross section of the relay core 3 has a relay core first layer 3a provided at the center of the cross section, and a relay core second layer 3b provided adjacent to the outside of the relay core first layer 3a.
The shape of the cross section of the relay core first layer 3a can be freely selected as long as it is disposed at the center of the cross section of the relay core 3. For example, it may be a circle, an ellipse, a square, a rectangle, a diamond, a star, or the like, but a substantially circular shape is more preferable.
The cross section of the relay core second layer 3b only needs to be adjacent to the outside of the relay core first layer 3a, with the inside being adjacent to and in contact with the outer circumferential surface of the relay core first layer 3a in the same shape, and the outside being freely selected in shape depending on the use and purpose of the liquid applicator 1. For example, it may be circular, elliptical, square, rectangular, etc. When the relay core first layer 3a is substantially circular, the relay core second layer 3b may be substantially donut-shaped (the outer periphery of the relay core second layer 3b is circular).

As shown in Fig. 7(a), when the relay core 3 is turned downward, the flow path width between the fibers of the relay core second layer 3b is larger than the flow path width between the fibers of the relay core first layer 3a, so the liquid 40 (especially when the viscosity is high) supplied from the rear end portion of the relay core 3 and the particles 40a contained in the liquid 40 are more likely to flow through the flow path of the relay core second layer 3b than through the relay core first layer 3a. Here, since the relay core second layer 3b is arranged in contact with and adjacent to the relay core first layer 3a, while the liquid 40 and the particles 40a contained in the liquid 40 flow from the liquid storage section 5 toward the tip portion of the relay core 3 (relay core-application pen tip contact portion 3c), particularly a part of the particles 40a also migrates to the relay core first layer 3a, and the liquid 40 and the particles 40a contained in the liquid 40 reach the center portion of the tip portion of the relay core 3, and the liquid 40 and the particles 40a contained in the liquid 40 that have reached there are supplied to the application pen tip 20 and used for writing and application. At this time, the liquid 40 and particles 40a that have flowed through the second relay core layer 3b to the tip portion are retained by the capillary force of the first relay core layer 3a, thereby preventing liquid 40 or particles 40a from falling from the relay core 3 and causing liquid leakage from the application pen tip 20.
7(b), when the relay core 3 is turned upward, some of the liquid 40 and particles 40a flow through the flow path of the relay core second layer 3b and drain back toward the liquid storage section 5. At this time, the liquid 40 and particles 40a that have migrated to the relay core first layer 3a are held as they are near the center of the tip of the relay core 3 (relay core-application pen tip contact portion 3c) due to capillary force.
When writing or application is started again with the relay core 3 facing downward, the liquid 40 and particles 40a that were held in the tip portion of the relay core 3 (near the relay core-application pen tip contact portion 3c) due to the capillary force of the relay core first layer 3a are immediately supplied to the application pen tip 20 and can be used for writing or application without being drained back. Therefore, it is possible to smoothly apply the liquid without having to wait for the liquid 40 and particles 40a to be supplied from the liquid storage portion 5 to the application pen tip 20 through the relay core 3.

The diameter of the cross section of the first relay core layer 3a and the layer thickness of the cross section of the second relay core layer 3b, i.e., the area of the cross section, are adjusted so that mechanisms such as the flow of the liquid 40 and particles 40a, migration between layers, drain back in the second relay core layer 3b, retention by capillary force in the first relay core layer 3a, and suppression of liquid leakage can function.
When the cross section of the first relay core layer 3a is substantially circular and the cross section of the second relay core layer 3b is substantially doughnut-shaped, the radius R of the cross section of the first relay core layer 3a is desirably set in the range of 1/5.1 to 18.5 times the layer thickness D of the second relay core layer 3b, that is, R/D. That is, the cross-sectional area of the first relay core layer 3a is desirably set in the range of 1/36 to 9 times the cross-sectional area of the second relay core layer 3b. The cross-sectional area of the first relay core layer 3a is desirably set in the range of preferably 1/20 to 9 times, more preferably 1/15 to 9 times, or 1/9 to 9 times, 1/8 to 9 times, 1/7 to 9 times, 1/6 to 9 times, 1/5 to 9 times, or 1/4 to 9 times the cross-sectional area of the second relay core layer 3b. The upper limit of each is preferably 9 times, more preferably 8 times, and even more preferably 5 times. If the area ratio is smaller than 1/36, the amount of liquid 40 and particles 40a that drain back increases when the relay core 3 is facing upward, and the amount of liquid held by the capillary force of the relay core first layer 3a decreases when the relay core 3 is facing downward. Also, if the area ratio exceeds 9, the flow path of the relay core second layer 3b is insufficient for the flow rate of the liquid 40 and particles 40a centered on the relay core second layer 3b, so clogging is likely to occur due to the liquid 40 and particles 40a that try to move and flow to the adjacent relay core first layer 3a, which has a stronger capillary force.
The optimal range of R/D, i.e., the optimal range of the area ratio, varies depending on the diameter of the fibers of the first relay core layer 3a and the second relay core layer 3b, the type of fibers, the type and viscosity of the liquid 40, the type and size of the particles 40a, the application of the relay core, etc., and is therefore adjusted as appropriate.

(Resin binder)
The resin binder of the relay core 3 is made of polyurethane resin, phenoxy resin, epoxy resin, melamine resin, or the like.

(Liquid applicator)
The pen tip of the present invention is applicable to liquid applicators such as writing instruments and cosmetic tools, etc. Furthermore, the relay core of the present invention is applicable to liquid applicators such as writing instruments and cosmetic tools, etc.

Examples of liquid applicators include liquid applicators for writing such as oil-based markers, water-based markers, board markers, line markers, paint markers, correction pens, and medical markers, medicinal liquid applicators, eyeliner, eyeshadow, eyebrow products, lip liner, lip gloss, concealer, nail care products, eyelash care products, and cosmetic liquid applicators such as nail polish brushes.

- Evaluation of pen tip (particle passage test) -
To evaluate the pen tip, the samples shown in Table 1 were prepared. Sample 1 is a pen tip according to one embodiment of the present invention, Sample 2 is a conventional thin single fiber core, Sample 3 is a conventional thick single fiber core, and Sample 4 is a liquid containing glitter particles used in the evaluation test.

The particle size distribution of the particles that passed through the pen tip of each sample was evaluated based on the particle size distribution of the particles in the liquid used in the evaluation test for sample 4.
For the evaluation, as shown in Figure 8, the evaluation pen tip was inserted into the insertion tube provided at the bottom of the container filled with the particle-containing liquid of sample 4, and the liquid that passed through the pen tip was sampled. The particle size distribution of the sampled liquid was measured to obtain the maximum particle size and average particle size. Table 2 shows the results of the particle passage test.

It was found that sample 1, which is one embodiment of the present invention, and sample 3, which is a conventional thick single fiber core, have particle size distributions almost similar to the standard, compared to the particle size distribution of sample 4, which serves as the reference. On the other hand, it was found that sample 2, which is a conventional thin single fiber core, has large particles remaining inside the evaluation pen tip, and has low passability.

- Pen tip evaluation (written test) -
The evaluation pen tip was assembled into a liquid applicator, and a writing test was carried out on paper.
First, half a day after assembling the evaluation pen tip, writing was performed on a paper surface, and the initial state of the liquid and the state of the glitter particles contained in the liquid were confirmed under magnification. The writing test was performed by placing a plain paper and writing 20 times back and forth in a zigzag pattern with a width of 2 cm under a load of 100 gf.
Next, after the initial writing was completed, the pen was placed with the tip facing up, capped, and stored for one week, and then written on paper again and the state of the liquid and the glitter particles contained in the liquid was observed under magnification. The results of the writing test are shown in Table 3.

At the beginning of writing, almost the same amount of liquid and particles were observed in the handwriting for sample 1, which is one embodiment of the present invention, and sample 3, which is a conventional thick single fiber core, and it was found that they had sufficiently passed through the evaluation pen tip. On the other hand, the number of particles observed in the handwriting for sample 2, which is a conventional thin single fiber core, was smaller than for samples 1 and 3, and it was found that they did not sufficiently pass through the evaluation pen tip.

After storing the pen tip facing up with the cap closed for one week, the liquid and particles observed in Sample 1, which is one embodiment of the present invention, were roughly the same as or slightly less than those observed in the initial writing. This result indicates that the liquid and particles were retained in the contact area between the pen tip and the object to be coated.
On the other hand, sample 3, a conventional thick single fiber core, which had good results in the particle passage test and the initial writing test, had become so impermeable that writing was impossible after one week of storage. This result indicates that the liquid and particles in the pen tip had drained back into the liquid storage section.
Furthermore, in the case of Sample 2, which is a conventional thin single fiber core, the number of particles observed in the handwriting was as small as that at the beginning of writing, and it was found that not enough particles could pass through the evaluation pen tip.

- Pen tip evaluation (writing feel test) -
In order to evaluate the writing feel of the pen tip on the skin, pen tips (samples 5 to 14) having the configurations shown in Table 4 were prepared. The fibers were polyamide fibers, with the single yarn of the first layer of the pen tip being 1.1 dtex and the single yarn of the second layer of the pen tip being 11 dtex. The outer diameter of the pen tip was 3.05 mm, and the range of 11.8 mm from the tip of the pen tip was cut so as to be inclined toward the tip of the pen tip, giving it a brush-like shape.
The pen tips of Samples 5 to 14 were incorporated into a direct liquid type cosmetic applicator equipped with a relay core, and eyeliner was applied to the eyes. The writing feel was evaluated based on whether it was smooth or painful, and the glitter discharge was evaluated by visually inspecting the applied eyeliner. The glitter discharge was evaluated as being sufficient with an ⊚ and good with an ◯. The results are shown in Table 4.

The writing feel was smooth in Samples 6 to 14. In contrast, pain was felt on the skin in Sample 5. It is considered that Sample 5 has a small radius of the first layer, and when applying eyeliner, the second layer, which has a large flow path width between fibers and thick fibers, comes into contact with the skin around the eyes, causing pain. That is, when applying eyeliner, the tip of the pen tip cut into a brush shape is used at about 1-2 mm, but it was found that it is desirable to adjust the inclination of the pen tip cut and the cross-sectional area of the first pen tip layer and the cross-sectional area of the second pen tip layer so that the cut-out second layer does not come into contact with the skin. It was found that in the pen tips evaluated in this writing feel test, it is desirable that the cross-sectional area of the first pen tip layer is 1/36 or more of the cross-sectional area of the second pen tip layer.
Furthermore, in the pen tips evaluated in this writing feel test, it was found that if the cross-sectional area of the first pen tip layer was 9.1 times the cross-sectional area of the second pen tip layer, the second pen tip layer would not come into contact with the skin, and the glitter would be discharged satisfactorily using the second pen tip layer as the main flow path.

A liquid applicator housing the pen tip or intermediate core of the present invention is capable of stable application (writing), and is expected to find wide application as a writing instrument and cosmetic tool that can apply the liquid and particles such as glitter and pearl pigments contained in the liquid applicator more efficiently than ever before.

1 Liquid applicator 2 Pen tip 2a Pen tip first layer 2b Pen tip second layer 2c Pen tip-applied object contact portion 20 Application pen tip 3 Relay core 3a Relay core first layer 3b Relay core second layer 3c Relay core-application pen tip contact portion 30 Relay core 4, 40 Liquid 4a, 40a Particles 5, 50 Liquid storage portion r Radius of cross section of pen tip first layer d Layer thickness of cross section of pen tip second layer R Radius of cross section of relay core first layer D Layer thickness of cross section of relay core second layer

Claims (10)

The pen tip and
A liquid storage portion;
A liquid applicator comprising:
The pen tip is made by bundling fibers in the longitudinal direction, bonding them with a resin binder, and then molding them into a desired shape, or by mixing two or more types of fibers with different melting points in large quantities, aligning them in the longitudinal direction, bundling them, compressing them, and bonding them by thermal fusion between the fibers ;
The cross section of the nib has a nib first layer provided at the center of the cross section and a nib second layer provided adjacent to the outside of the nib first layer,
A flow path width between fibers in the first pen tip layer through which liquid passes is smaller than a flow path width between fibers in the second pen tip layer through which liquid passes;
A liquid applicator, wherein both the rear end portion of the pen tip first layer and the rear end portion of the pen tip second layer are configured to be immersed in the liquid contained in the liquid containing section . 2. The liquid applicator according to claim 1, wherein a cross section of the first pen tip layer is substantially circular, a cross section of the second pen tip layer is substantially donut shaped, and an area of the cross section of the first pen tip layer is 1/36 to 9 times an area of the cross section of the second pen tip layer. 3. The liquid applicator according to claim 1, wherein a single yarn of the fiber of the pen tip first layer is 0.3 dt ex to 7.7 dt ex, and a single yarn of the fiber of the pen tip second layer is 5.5 dt ex to 22 dt ex. The liquid applicator according to claim 1 , wherein the fibers are polyamide fibers, polyester fibers, or acrylic fibers. The liquid applicator according to claim 1 , wherein the resin binder is a polyurethane resin, a phenoxy resin, an epoxy resin, or a melamine resin, and the liquid contains particles. A relay core,
A liquid storage portion;
A liquid applicator comprising:
The intermediate core is a material obtained by bundling fibers in the longitudinal direction, bonding them with a resin binder, and then forming them into a desired shape, or by mixing two or more types of fibers having different melting points in large quantities, aligning them in the longitudinal direction, bundling them, compressing them, and bonding them by thermal fusion between the fibers ;
The cross section of the relay core has a first relay core layer provided at the center of the cross section, and a second relay core layer provided adjacent to the outside of the first relay core layer, the width of a flow path between fibers in the first relay core layer through which a liquid passes is smaller than the width of a flow path between fibers in the second relay core layer through which a liquid passes,
A liquid applicator, wherein a rear end portion of the first relay core layer and a rear end portion of the second relay core layer are both configured to be immersed in the liquid contained in the liquid containing section . 7. The liquid applicator according to claim 6, wherein a cross section of the first relay core layer is substantially circular, a cross section of the second relay core layer is substantially donut-shaped, and an area of the cross section of the first relay core layer is 1/36 to 9 times an area of the cross section of the second relay core layer. 8. The liquid applicator according to claim 6, wherein a single yarn of the fiber of the first layer of the relay core has a fineness of 0.3 dtex to 7.7 dtex , and a single yarn of the fiber of the second layer of the relay core has a fineness of 5.5 dtex to 22 dtex . The liquid applicator according to claim 6 , wherein the fibers are polyamide fibers, polyester fibers, or acrylic fibers. The liquid applicator according to claim 6 , wherein the resin binder is a polyurethane resin, a phenoxy resin, an epoxy resin, or a melamine resin, and the liquid contains particles.

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