Liquid ejection nozzle for washing and method for washing washing object

Abstract

To provide a liquid ejection nozzle for washing and a method for using the same that can accurately hit liquid at stain in a washing object surface and can wash stain from a washing object surface safely and efficiently.SOLUTION: A nozzle 1 is a liquid ejection nozzle for washing. The nozzle 1 preferably includes an ejection plate 2 including one or more through-holes 21 from which liquid is ejected. The through-hole 21 preferably has a tapered shape of which internal diameter decreases toward an ejection direction F of liquid L. An internal diameter of an ejection port 23 in the through-hole 21 is preferably 10 μm or more and 200 μm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cleaning liquid ejection nozzle and a method for cleaning an object to be cleaned. [Background technology]

[0002] Conventionally, cleaning devices that discharge a liquid onto the surface of an object to be cleaned to clean it have been known. For example, Patent Document 1 proposes a cleaning device that includes a liquid spray nozzle having a spray nozzle hole, a pressurized liquid supply unit that pressurizes the liquid and sends it to the liquid spray nozzle, and a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid sprayed from the spray nozzle hole to fly in a state in which the liquid is broken up into droplets from a continuous stream. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-128918 Summary of the Invention [Problem to be solved by the invention]

[0004] A cleaning device that discharges a liquid onto the surface of an object to be cleaned to clean it is preferable to be able to safely and efficiently clean dirt from the surface of the object to be cleaned. However, in the cleaning device, the discharged liquid tends to spread or disperse (see FIG. 9), making it difficult to accurately apply the liquid to the desired area. As a result, there are cases where the liquid hits unintended areas, such as getting into the eyes. In addition, there are cases where it is difficult to efficiently clean the surface of the object to be cleaned. The cleaning device described in Patent Document 1 does not consider how to prevent the discharged liquid from spreading, leaving room for improvement.

[0005] Therefore, an object of the present invention is to provide a cleaning liquid ejection nozzle and a method for using the same that can accurately apply liquid to dirt on the surface of an object to be cleaned and safely and efficiently clean the dirt from the surface of the object to be cleaned. [Means for solving the problem]

[0006] The present invention relates to a nozzle for discharging a cleaning liquid. In one embodiment, it is preferable to have a discharge plate with one or more through holes through which the liquid is discharged. In one embodiment, the through-hole preferably has a tapered shape in which the inner diameter decreases in the direction of ejection of the liquid. In one embodiment, the inner diameter of the outlet of the through-hole is preferably 10 μm or more and 200 μm or less.

[0007] The present invention also relates to a cleaning method using a cleaning liquid discharge nozzle. In one embodiment, it is preferable that a liquid is discharged from the discharge port of the through hole and the liquid is applied to a portion to be cleaned of the object to be cleaned, thereby removing dirt from the surface of the object to be cleaned. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a liquid discharge nozzle for cleaning that can accurately apply the discharged liquid to dirt on the surface of the object to be cleaned, and can safely and efficiently clean the dirt on the surface of the object to be cleaned. [Brief explanation of the drawings]

[0009] [Figure 1] Fig. 1(a) is a perspective view showing a preferred embodiment of a liquid discharge nozzle of the present invention, and Fig. 1(b) is a cross-sectional view taken along line II of Fig. 1(a). [Figure 2] Figure 2(a) is an enlarged cross-sectional view of the through-hole shown in Figure 1. Figure 2(b) is an enlarged cross-sectional view showing another embodiment of the through-hole. [Figure 3] FIG. 3 is a plan view of the discharge plate of the nozzle shown in FIG. [Figure 4] Figure 4(a) is a plan view showing the arrangement of the through holes shown in Figure 3. Figure 4(b) is a plan view showing another embodiment of the arrangement of the through holes. [Figure 5]FIG. 5 is a view corresponding to FIG. 2, showing another embodiment of a through hole according to the present invention. [Figure 6] FIG. 6 is a side view schematically showing a state in which liquid is ejected in a continuous flow state from the nozzle shown in FIG. [Figure 7] FIG. 7 is a perspective view for explaining how to use the nozzle shown in FIG. 1, showing a state in which the nozzle is used to cleanse the skin. [Figure 8] FIG. 8 is an enlarged perspective view illustrating how to use the nozzle shown in FIG. 1 when cleaning the surface of a tooth. [Figure 9] FIG. 9 is a side photograph showing a state in which liquid is ejected from a conventional liquid ejection nozzle. [Figure 10] FIG. 10 is a side view photograph showing a state in which liquid is being ejected from the liquid ejection nozzle of the present invention. [Figure 11] FIG. 11 is a view corresponding to FIG. 2, showing still another embodiment of a through hole according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a cleaning liquid discharge nozzle 1 (hereinafter also referred to as "nozzle 1") of the present invention will be described with reference to preferred embodiments thereof. The nozzle 1 of the present invention is typically used to clean a surface S to be cleaned, including keratinous materials, teeth, etc. The object to be cleaned is preferably a human, but may also be a non-human animal, such as a pet dog or cat. Keratinous materials include skin, scalp, hair, nails, etc. Skin includes skin on the face, arms, hands, feet, back, etc. Dirt on the surface S to be cleaned with the nozzle 1 typically includes sebum, sweat, dead skin cells, pollen, yellow sand, PM2.5, mud, sand, viruses, food, dental plaque, etc. The nozzle 1 has a flow path for liquid L inside.

[0011] The nozzle 1 of the present invention preferably includes a cylindrical base 4 in which a large-diameter cylinder 46 and a small-diameter cylinder 45 having an inner diameter smaller than that of the large-diameter cylinder 46 are connected together, and a discharge plate 2 fixed to the large-diameter cylinder 46 (see FIG. 1(a)). Typically, the base 4 has the small-diameter cylinder 45 connected to one axial end of the large-diameter cylinder 46, with the axial directions of the large-diameter cylinder 46 and the small-diameter cylinder 45 aligned (see FIG. 1(b)). Typically, the opening of the large-diameter cylinder 46 on the axial opposite side to the small-diameter cylinder 45 is closed by the discharge plate 2.

[0012] A liquid supply unit (not shown) that supplies the liquid L is typically connected to the end of the small-diameter cylinder 45 opposite the large-diameter cylinder 46 in the axial direction. The liquid supply unit typically includes a supply pump. The liquid supply unit is controlled by the supply pump to apply pressure for discharging the liquid L. This preferably configures the nozzle 1 so that a predetermined amount of liquid L is supplied continuously or discontinuously, or the supply is stopped. In this embodiment, small-diameter cylinder 45 has a flange 49 at the end opposite to large-diameter cylinder 46 in the axial direction. Flange 49 protrudes radially outward from the outer circumferential surface of small-diameter cylinder 45, and is provided with a locking portion (not shown) for connecting a supply hose provided in the liquid supply portion.

[0013] The nozzle 1 typically has a discharge direction F along the axial direction of the base 4. This discharge direction F typically coincides with the axial directions of the large-diameter cylinder 46 and the small-diameter cylinder 45. Hereinafter, the end of the nozzle 1 on the discharge plate 2 side in the discharge direction F will also be referred to as the "tip end," and the end on the opposite side of the discharge plate 2 in the discharge direction F will also be referred to as the "base end." In the nozzle 1, it is preferable that the internal spaces of the large-diameter cylinder 46 and the small-diameter cylinder 45 communicate with each other in the discharge direction F. This allows the internal spaces to form a flow path for the liquid L. The liquid L supplied to the nozzle 1, i.e., the liquid L supplied from the opening on the base end side of the small-diameter cylinder 45, moves through the small-diameter cylinder 45, the large-diameter cylinder 46, and the discharge plate 2 in this order. In the base 4 of the present invention, the length of the small diameter cylinder 45 in the discharge direction may be longer than that of the large diameter cylinder 46. That is, the base 4 may have a mushroom shape in cross section along the discharge direction F (see FIG. 1(b)).

[0014] The discharge plate 2 is preferably a sheet-like member having a front surface and a back surface. The back surface of the discharge plate 2 is typically the surface facing the large-diameter cylinder 46 of the base 4. The discharge plate 2 covers the entire opening on the tip side of the large-diameter cylinder 46, and is preferably liquid-tightly joined to the large-diameter cylinder 46 by a joint 5 formed along the periphery of the opening. Such a joint 5 can be formed by known joining means such as heat fusion, ultrasonic waves, or adhesives. 1(b), the discharge plate 2 may be a flat plate or a curved plate that is curved entirely or partially. The front or back surface of the discharge plate 2 may be a smooth surface or an uneven surface. The discharge plate 2 preferably has one or more through holes 21 penetrating the discharge plate 2 in the thickness direction. The through hole 21 preferably has an inlet 22 through which the liquid L flows in and an outlet 23 through which the liquid L is discharged in the discharge direction F. The inlet 22 and the outlet 23 are in communication with each other, and the central axes of the inlet 22 and the outlet 23 are aligned. The liquid L supplied to the nozzle 1 is discharged out of the nozzle 1 through the through hole 21. A typical example of this is shown in FIG. 1(b).

[0015] The through hole 21 of the present invention typically has a circular shape in a cross section perpendicular to the discharge direction F. The cross-sectional shape of the through hole 21 is not particularly limited, and may be a square, an ellipse, or the like. From the viewpoint of improving the uniformity of the discharge pressure in the through hole 21, the cross-sectional shape of the through hole 21 is preferably a circular shape.

[0016] The discharge plate 2 has a first direction X and a second direction Y perpendicular to the first direction X in a plan view (see FIG. 3). The discharge plate 2 typically has a plurality of through holes 21 arranged in a dispersed state in a plan view. That is, the plurality of through holes 21 are arranged in a dispersed state in the first direction X and the second direction Y. A typical discharge plate 2 has a through-hole row 21L in which a plurality of through-holes 21 are arranged at intervals along the second direction Y. Two or more rows of the through-hole rows 21L are provided at intervals in the first direction X. The positions of the through-holes 21 constituting the through-hole rows 21L adjacent to each other in the first direction X are aligned in the second direction Y. Alternatively, the nozzle 1 may have only one row of through-holes 21L.

[0017] The discharge plate 2 typically has a through-hole arrangement region 21R in which two or more through-holes 21 are arranged. The through-hole arrangement region 21R typically has two or more rows of the aforementioned through-hole rows 21L arranged therein. The outline shape of the through-hole arrangement region 21R in a plan view can be any shape, such as a circle, an ellipse, a rectangle, a hexagon, or a substantially square shape with rounded corners. A typical example is shown in FIG. 3. The contour shape of the through-hole arrangement region 21R is the contour shape of the region defined by a virtual line K connecting the outer edges of the through-holes 21 located most outward in either or both of the first direction X and the second direction Y in a plan view.

[0018] The through-holes 21 of the discharge plate 2 preferably have a tapered shape in which the inner diameter decreases in the discharge direction F of the liquid L. That is, the inner diameter of the through-holes 21 preferably gradually decreases from the inlet 22 toward the discharge outlet 23. The cross-sectional shape of the through-hole 21 along the discharge direction F preferably has a pair of tapered edges 21a, 21b that extend so as to converge toward the central axis of the discharge port 23. From the viewpoint of reducing pressure loss, the pair of tapered edges 21a, 21b of the present invention are preferably curved edges that curve toward the central axis of the discharge port 23 (see FIGS. 2(a) and 2(b)). In a cross-sectional view of through-hole 21 along discharge direction F, the portion where tapered edges 21a, 21b exist is also referred to as a "tapered portion 24." Through-hole 21 may have tapered portion 24 over the entire area in discharge direction F from inlet 22 to discharge outlet 23. A typical example of this is shown in FIG. 2(a). Furthermore, tapered portion 24 may be partially formed on the discharge outlet 23 side in discharge direction F. A typical example of this is shown in FIG. 2(b). In the latter case, through hole 21 typically has a non-tapered portion 25 with a constant inner diameter on the inlet 22 side in the discharge direction F. Non-tapered portion 25 is a portion where the edge of through hole 21 is parallel to the axial direction (discharge direction F) in a cross-sectional view of the through hole along the discharge direction F. Note that, from the viewpoint of further suppressing diffusion of liquid L, tapered portion 24 is preferably formed closer to discharge port 23 in the discharge direction F than non-tapered portion 25.

[0019] When the shape of through-hole 21 in plan view is circular, the circle is not limited to a perfect circle, and may be elliptical. When through-hole 21 is elliptical, for example, the ratio of the minor axis to the major axis (minor axis / major axis) is preferably less than 1.0, more preferably 0.98 or less, and even more preferably 0.95 or less. The diameter of the ellipse is the equivalent circle diameter converted into the diameter of a perfect circle with the same cross-sectional area.

[0020] From the viewpoint of improving the ejection properties, the inner diameter D2 of the ejection port 23 of the through-hole 21 is preferably 10 μm or more, and more preferably 20 μm or more. From the viewpoint of improving the cleaning power, the inner diameter D2 of the discharge port 23 of the through-hole 21 is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 110 μm or less.

[0021] It is practically difficult to form small-diameter, straight through-holes, for example, straight through-holes with an inner diameter of 250 μm or less, by machining. For example, drilling makes it difficult to form uniform holes due to the strength of small-diameter drills and deformation caused by heat and vibrations generated in small areas during drilling, and it is also not easy to procure small-diameter drills. Furthermore, forming the through-holes by means other than machining, such as a laser processing machine, poses problems such as an increase in the size of the processing machine and high costs for introducing the processing machine and / or processing.

[0022] The discharge plate 2 of the present invention preferably has one or more through holes 21, each having an inner diameter D2 of the discharge port 23 within the aforementioned range, and the through holes 21 preferably have a tapered shape in which the inner diameter decreases in the discharge direction F of the liquid L. The inventors discovered that when the liquid L is discharged from a nozzle 1 having such a configuration, the liquid L flows straight from each through hole 21 as an independent continuous stream (see FIGS. 6 and 10). More specifically, they discovered that the liquid discharged from each through hole 21 is less likely to diffuse or disperse. In particular, when there are multiple through holes 21, the liquids discharged from the respective through holes 21 do not merge, and the individual discharged liquids do not disperse, so that they accurately hit the area to be cleaned in a substantially linear continuous stream. This prevents the liquid L from hitting an unintended area, such as getting into the eyes. Furthermore, because the liquid L can be accurately applied to the desired area, such as the stain, the cleaning time can be shortened and the amount of liquid L used can be reduced. As a result, stains on the object to be cleaned can be efficiently cleaned. Furthermore, in the nozzle 1 of the present invention, the liquid L is discharged from the through-hole 21 whose discharge port 23 has an inner diameter within the aforementioned range, so that the liquid L can be softened in contact with the area to be cleaned. This reduces damage to the area to be cleaned, and the dirt on the object to be cleaned can be safely washed. In this way, the nozzle 1 of the present invention can safely and efficiently clean dirt from the surface of an object to be cleaned while minimizing damage to the object to be cleaned.

[0023] From the viewpoint of further improving the linearity of the ejected liquid L, the inner diameter D1 of the inlet 22 of the through hole 21 is preferably 20 μm or more, more preferably 50 μm or more, provided that it is larger than the inner diameter D2 of the ejection port 23. In order to further prevent the discharged liquid L from spreading or dispersing, and to enable a greater water flow per unit area of ​​the area to be cleaned by reducing the distance between adjacent discharge ports 23, the inner diameter D1 of the inlet 22 in the through hole 21 is preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 350 μm or more, provided that it is larger than the inner diameter D2 of the discharge port 23.

[0024] From the viewpoint of further improving the linearity of the ejected liquid L, the ratio (D1 / D2) of the inner diameter D1 of the inlet 22 to the inner diameter D2 of the ejection outlet 23 is preferably greater than 1.0, more preferably 1.1 or more, and even more preferably 1.5 or more. In order to better prevent the dispersion and diffusion of the discharged liquid L and to enable a larger water flow per unit area of ​​the area to be cleaned by reducing the distance between adjacent discharge ports 23, the ratio (D1 / D2) of the inner diameter D1 of the inlet 22 to the inner diameter D2 of the discharge port 23 is preferably 40 or less, more preferably 20 or less, and even more preferably 10 or less. Considering the above, the ratio (D1 / D2) of the inner diameter D1 of the inlet 22 to the inner diameter D2 of the outlet 23 is preferably more than 1.0 and 40 or less, more preferably 1.1 or more and 20 or less, and even more preferably 1.5 or more and 10 or less.

[0025] In the nozzle 1 of this embodiment, it is preferable that the dimensions of the through-hole 21 be changed appropriately depending on the part to be cleaned of the object to be cleaned. For example, when using nozzle 1 to cleanse the skin, from the viewpoint of preventing clogging of the nozzle and further improving cleaning performance, the inner diameter D2 of outlet 23 is preferably 15 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and even more preferably 40 μm or more. In addition, in order to further improve cleaning performance and further prevent the liquid L from splashing around during cleaning, the inner diameter D2 of the discharge port 23 is preferably 100 μm or less, more preferably 80 μm or less, even more preferably 70 μm or less, and even more preferably 60 μm or less.

[0026] When using the nozzle 1 to cleanse the skin, in order to further improve the straightness of the ejected liquid L, the inner diameter D1 of the inlet 22 is preferably 20 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and even more preferably 200 μm or more. In addition, from the viewpoint of directing a larger amount of water flow per unit area of ​​the part to be cleaned by shortening the distance between adjacent outlets 23, the inner diameter D1 of the inlet 22 is preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 350 μm or less.

[0027] When the nozzle 1 of the present invention is used to clean the oral cavity, in order to further improve plaque removal from interdental areas, tooth surfaces, etc., the inner diameter D2 of the outlet 23 is preferably 50 μm or more, more preferably 60 μm or more, and even more preferably 70 μm or more. In order to achieve a softer contact (contact) with the oral cavity, the inner diameter D2 of the discharge port 23 is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 130 μm or less.

[0028] When using the nozzle 1 to clean the oral cavity, in order to further improve the straightness of the ejected liquid L, the inner diameter D1 of the inlet 22 is preferably 70 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and even more preferably 200 μm or more. In addition, from the viewpoint of directing a larger amount of water flow per unit area of ​​the part to be cleaned by shortening the distance between adjacent outlets 23, the inner diameter D1 of the inlet 22 is preferably 700 μm or less, more preferably 400 μm or less, and even more preferably 350 μm or less.

[0029] From the viewpoint of improving the linearity of the ejected liquid L, the length T of the ejection flow path formed by the through-hole 21 of the nozzle 1 is preferably 100 μm or more, and more preferably 200 μm or more. From the viewpoint of reducing the pressure loss of the discharged liquid L, the length T of the discharge flow path is preferably 3000 μm or less, more preferably 2000 μm or less, and even more preferably 1000 μm or less.

[0030] In the present invention, the through hole arrangement region 21R is typically formed in a part of the discharge plate 2. That is, the discharge plate 2 of the present invention typically has the through hole arrangement region 21R in which a plurality of through holes 21 are formed, and a non-through hole arrangement region in which no through holes 21 are formed. In the discharge plate 2 of the present invention, typically, the through-hole arrangement region 21R is surrounded by a non-through-hole arrangement region in a plan view, which makes it more difficult for the discharge pressure acting on the discharge plate 2 to be dispersed, thereby further improving the cleaning power.

[0031] In order to further suppress dispersion of the discharge pressure and enhance the cleaning power, the unit area (1 cm ) of the discharge plate 2 when the nozzle 1 is viewed from above is 2 The number N of through holes 21 per unit area (hereinafter also referred to as "the number N of through holes 21 per unit area") is preferably 1500 / cm 2 Less than 1000 particles / cm, more preferably 1000 particles / cm 2 More preferably, 500 particles / cm or less 2 The following is the result. From the viewpoint of increasing the number of nozzles and further improving the cleaning efficiency, the number N of through holes 21 per unit area is preferably 20 / cm 2 More than 50 / cm 2 More preferably, 100 / cm 2 That's all. The number N of the through holes 21 per unit area can be calculated by the following method.

[0032] <Method of calculating the number N of through holes 21 per unit area> The number N of through holes 21 is the total area (cm ) of the through hole arrangement region 21R in which the through holes 21 are arranged in a dispersed manner in the planar direction when the nozzle 1 is viewed from above. 2 ) and the number of through holes 21 included in the region, the number of through holes / total area of ​​the through-hole arrangement region 21R can be calculated.

[0033] In the present invention, it is preferable that all of the through holes 21 present in the discharge plate 2 have a tapered shape having the above-mentioned configuration. At least some of the plurality of through holes 21 may have a tapered shape. From the viewpoint of further suppressing coalescence of the discharged liquid L, the proportion of the through holes 21 having a tapered shape to the total number of through holes 21 is preferably 50% or more and 100% or less, more preferably 80% or more and 100% or less.

[0034] From the viewpoint of accurately directing the water flow onto the area to be cleaned, the area ratio of the through-hole arrangement region 21R in the discharge plate 2 is preferably 10% or more, and more preferably 50% or more. Moreover, from the viewpoint of further suppressing dispersion of the discharge pressure and further enhancing the cleaning power, the area ratio is preferably 100% or less, and more preferably 80% or less.

[0035] From the viewpoint of further suppressing coalescence of the ejected liquid L, when the nozzle 1 is viewed in plan, the distance G between the centers of adjacent through holes 21 is preferably 0.1 mm or more, and more preferably 0.2 mm or more. From the viewpoint of further improving the detergency, the distance G is preferably 3 mm or less, and more preferably 2 mm or less. When the through holes 21 are adjacent to each other in both the first direction X and the second direction Y, only one of the distance Gx between the centers of the adjacent through holes 21 in the first direction X and the distance Gy between the centers of the adjacent through holes 21 in the second direction Y may be within the above-mentioned range. Both the distance Gx and the distance Gy may be within the above-mentioned range (see FIG. 4(a)).

[0036] In the nozzle 1 of the present invention, the positions in the second direction Y of the through holes 21 constituting adjacent through hole rows 21L in the first direction X do not have to match. Typically, the phases in which the through holes 21 are arranged in the through hole rows 21L adjacent to each other in the first direction X are shifted, and the through holes 21 are arranged in a staggered pattern overall. When the positions in the second direction Y of the through holes 21 constituting adjacent through hole rows 21L in the first direction X do not match each other, the distance Gx between the centers of the through holes 21 adjacent to each other in the first direction X is defined as the distance along the first direction X between the through holes 21 constituting adjacent through hole rows 21L in the first direction X. An example is shown in FIG. 4(b).

[0037] Next, the constituent materials of the nozzle 1 will be described. From the viewpoint of improving the handling and processability of the material, the discharge plate 2 of the nozzle 1 preferably contains a thermoplastic resin. It is more preferable that the discharge plate 2 is formed from a base sheet containing a thermoplastic resin. The thermoplastic resin may include one or more selected from polyolefin, polyester, polyamide, polyamideimide, polyetheretherketone, polyetherimide, polycarbonate, polyvinyl chloride, acrylic resin, polystyrene resin, and the like. The polyolefin may include one or more selected from polypropylene, polyethylene, and the like. The polyester may include one or more selected from polyethylene terephthalate, polybutylene terephthalate, polyfatty acid ester, polylactic acid, polycaprolactone, polybutylene succinate, and the like. The polyamide may include one or more selected from nylon and the like. From the viewpoint of biodegradability, it is preferable that the polyfatty acid ester contains one or more selected from polylactic acid and polyglycolic acid.

[0038] When the joint 5 is formed by fusion, from the viewpoint of ease of forming the joint, it is preferable that the base 4 of the nozzle 1 is formed containing the same type of thermoplastic resin as the discharge plate 2. Note that when the joint 5 is formed using an adhesive, the base 4 may be formed of a material different from that of the discharge plate 2, and may be made of, for example, metal.

[0039] From the viewpoint of further improving the moldability and dimensional stability of the through-hole 21, the mass ratio of the thermoplastic resin contained in the nozzle 1 to the total mass of the nozzle 1 is preferably 50 mass % or more, and more preferably 70 mass % or more. Furthermore, various effects may be imparted by adding a functional agent to the nozzle 1. In this case, the ratio of the mass of the thermoplastic resin contained in the nozzle 1 to the total mass of the nozzle 1 is preferably 100 mass % or less. Here, the various functional agents that can be used include one or more selected from antibacterial agents, bactericides, moisturizing agents, flow improvers, antistatic agents, coloring agents, and the like.

[0040] Although the present invention has been described based on its preferred embodiments, the present invention is not limited to the above-described embodiments and can be modified as appropriate. There are no particular limitations on the arrangement pattern of the through holes 21. For example, typically, in the nozzle 1, the through holes 21 are arranged in an array (single or multiple rows). In addition to the array, the through holes 21 may be arranged in any other shape, such as a circle, a star, or the like. The through hole 21 described above has a funnel-shaped cross section in the discharge direction F. When the cross section in the discharge direction F is funnel-shaped, the laterally opposing edges of the through hole 21 may be curved or may be linear as shown in FIG.

[0041] In the examples shown in FIGS. 2 and 5 described above, both surfaces of the through hole 21, i.e., the surface where the inlet 22 opens and the surface where the outlet 23 opens, are flat. Alternatively, as shown in FIG. 11 , the through hole 21 may have a raised portion formed by deformation of the discharge plate 2 at the periphery of the through hole 21. For example, the discharge plate 2 may be deformed at the periphery of the through hole 21 so that both the surface where the inlet 22 opens and the surface where the outlet 23 opens face in the discharge direction F. Note that, from the viewpoint of further suppressing coalescence of the discharged liquid L even when the discharge pressure is increased to increase the discharge speed and discharge flow rate of the liquid L, it is preferable that the through hole 21 have both flat surfaces, as shown in FIGS. 2 and 5 . If a raised portion is formed at the periphery of the through hole 21 as shown in FIG. 11 , the tip of the raised portion may be deformed by an external force such as rubbing, which may make the discharged liquid more likely to spread or disperse.

[0042] A cleaning method using the nozzle 1 of the present invention configured as above will now be described. The cleaning method using the nozzle 1 of the present invention is preferably carried out by connecting the nozzle 1 to a liquid supply unit 20 filled with liquid L. For example, the nozzle 1 is connected to the liquid supply unit 20 that supplies the liquid L, and the liquid L is supplied to the liquid supply unit 20 by a known liquid supply means such as a constant-rate liquid feed pump. The liquid L is then discharged in a straight line from the discharge outlets 23 of each through-hole 21 in the discharge direction F. By directing the discharged liquid L at the area to be cleaned on the object to be cleaned, dirt on the surface of the object to be cleaned can be removed. The liquid supply unit 20 is controlled by a supply pump that constitutes the supply unit, and is given pressure to discharge the liquid L. This is preferably configured so that a predetermined amount of liquid L is supplied continuously or discontinuously toward the nozzle outlet, or the supply is stopped.

[0043] In the cleaning method using the nozzle 1 of the present invention, it is also preferable that the liquid L discharged from the through-holes 21 contacts the area to be cleaned of the object to be cleaned in a state in which the liquid L comprises a substantially linear continuous flow. Furthermore, it is preferable that at a certain moment during cleaning, the liquid L is continuously flowing from the discharge port 23 to the area to be cleaned of the object to be cleaned without interruption (see FIGS. 7 and 8). By discharging the liquid L from the through-holes 21 and contacting the surface S of the object to be cleaned in a state in which the liquid L comprises a substantially linear continuous flow, the liquid L can be applied to the desired area with high precision, and the surface S of the object to be cleaned can be efficiently cleaned. This improves the linearity of the discharged liquid L, allowing the liquid L to be applied to the dirt on the surface S of the object to be cleaned with high precision.

[0044] Here, the "approximately linear continuous flow" is a straight flow along the discharge direction F, and is the main discharge form of the liquid L immediately after being discharged from the through-hole 21. The liquid L discharged from the through-hole 21 may contain one or more "approximately linear continuous flows," as well as liquid flows or droplets that are more intermittent than the continuous flows. The "approximately linear continuous flow" can be confirmed by the following method.

[0045] <How to check for a nearly linear continuous flow> The nozzle is connected to a liquid supply unit with the discharge direction F aligned with the horizontal direction, and liquid L is supplied to the nozzle so that the discharge speed from the discharge port 23 is 10 m / sec or more and 40 m / sec or less, causing the liquid L to be discharged from the discharge port 23 of the through-hole 21. Five seconds after the start of this discharge, an image of the liquid L being discharged from the nozzle 1 is taken. In the obtained image, the liquid flow discharged from the through-hole 21 along the discharge direction F is selected, and the ratio J is calculated using the following formula. A liquid flow with a ratio J of 10 or more is considered to be a "substantially linear continuous flow." Ratio J = Continuous length of liquid flow La / Width of liquid flow Wa The "continuous length of the liquid flow La" is the maximum length of the continuous liquid flow between the discharge port 23 and a position P 30 mm away in the discharge direction F. The "width of the liquid flow Wa" is the width of the liquid flow at the position P, and is the length in the direction perpendicular to the continuous direction of the liquid flow (discharge direction F).

[0046] In the cleaning method using the nozzle 1 of the present invention, from the viewpoint of suppressing damage to the object to be cleaned, it is preferable to set the distance between the outlet 23 and the part to be cleaned at preferably 0.5 mm or more, more preferably 1 mm or more. In order to further improve the cleaning power, apply the liquid to the desired area more accurately, and prevent the liquid L from splashing around, it is preferable to set the distance between the outlet 23 and the area to be cleaned to preferably 300 mm or less, more preferably 100 mm or less, even more preferably 50 mm or less, and particularly preferably 30 mm or less.

[0047] In the cleaning method using the nozzle 1 of the present invention, from the viewpoint of further improving cleaning power, it is preferable to perform the cleaning at a discharge speed of the liquid L of preferably 10 m / sec or more, more preferably 12 m / sec or more, and even more preferably 15 m / sec or more. In order to prevent damage to the object to be cleaned and to prevent the liquid L from splashing around, it is preferable to set the ejection speed of the liquid L to 40 m / sec or less, more preferably 35 m / sec or less, and even more preferably 30 m / sec or less. The discharge rate can be measured by the following method.

[0048] <Method for measuring discharge speed> The liquid L is supplied to the nozzle, and the discharge flow rate (mm 3 / sec, and the flow rate was calculated based on the total area (mm 2 ) to obtain the discharge speed (liquid discharge flow rate per unit time / total area of ​​discharge ports 23). If the discharge plate 2 has multiple through-holes 21, the total area of ​​the discharge ports 23 is the value obtained by multiplying the area of ​​each discharge port 23 by the total number of discharge ports 23 (through-holes 21).

[0049] In the cleaning method using the nozzle 1 of the present invention, from the viewpoint of further improving the cleaning power, it is preferable to carry out the cleaning at a supply pressure of the liquid L of preferably 0.05 MPa or more, more preferably 0.1 MPa or more. From the viewpoint of suppressing damage to the object to be cleaned, it is preferable to set the supply pressure of the liquid L to 10 MPa or less, more preferably 5 MPa or less, and even more preferably 1 MPa or less. The supply pressure is the set pressure value of the supply pump.

[0050] From the viewpoint of further suppressing coalescence of the ejected liquid L and further improving the cleaning power, the viscosity of the liquid L used in the present invention is preferably 0.5 mPa·s or more, more preferably 1 mPa·s or more. From the viewpoint of further improving the ejection properties, the viscosity of the liquid L is preferably 40 mPa·s or less, and more preferably 30 mPa·s or less. The viscosity of the liquid L described above is a value measured at 30° C. using a B-type viscometer (TVB-10 type viscometer manufactured by Toki Sangyo Co., Ltd.) The measurement conditions in this case are rotor No. M1, a rotation speed of 60 rpm, and a measurement time of 60 seconds.

[0051] In the cleaning method using the nozzle 1 of the present invention, the total discharge flow rate of the liquid L discharged from the nozzle 1 is preferably 10 mL / min or more, more preferably 20 mL / min or more, and even more preferably 40 mL / min or more, from the viewpoint of ensuring the amount of liquid L necessary for cleaning. In order to prevent the liquid L from scattering around, the total discharge flow rate of the liquid L discharged from the nozzle 1 is preferably 1000 mL / min or less, more preferably 500 mL / min or less, and even more preferably 300 mL / min or less.

[0052] In the cleaning method using the nozzle 1 of the present invention, the discharge flow rate per through hole 21 is preferably 0.05 mL / min or more, more preferably 0.5 mL / min or more, and even more preferably 1.0 mL / min or more, from the viewpoint of ensuring the amount of liquid L necessary for cleaning. In order to prevent the liquid L from scattering around, the discharge flow rate per through-hole 21 is preferably 50 mL / min or less, more preferably 10 mL / min or less, and even more preferably 5 mL / min or less. The discharge flow rate per through-hole 21 is an average value obtained by dividing the total discharge flow rate of the liquid L discharged from the nozzle 1 by the number of through-holes 21 .

[0053] In the cleaning method using the nozzle 1 of the present invention, from the viewpoint of further improving the cleaning power, it is preferable to carry out the cleaning with the discharge load of the liquid L set to preferably 0.01 N or more, more preferably 0.1 N or more. From the viewpoint of suppressing damage to the object to be cleaned, it is preferable to set the discharge load of the liquid L to be 1.0 N or less, and more preferably 0.4 N or less. The method for measuring the discharge load will be explained in the examples below.

[0054] The liquid L used in the present invention may contain one or more components used in ordinary detergent compositions, provided that the effects of the present invention are not impaired. When the liquid L contains water, the water content is preferably 20% by mass or more, and more preferably 40% by mass or more. A preferred example of the liquid L is a liquid containing a surfactant, for example, an aqueous liquid containing a surfactant at a critical micelle concentration or more.

[0055] The liquid L may contain one or more substances selected from water, surfactants, polyhydric alcohols, oils, polysaccharides, organic solvents, inorganic or organic salts, moisturizing ingredients, silicone derivatives, polyoxyalkylenes, pH adjusters, anti-inflammatory agents, disinfectants, preservatives, sequestering agents, antioxidants, UV absorbers, anionic polymers, nonionic polymers, amphoteric polymers, fragrances, thickeners, vitamins, and colorants. The silicone derivative may contain one or more selected from polyoxyalkylene-modified silicones. The polyoxyalkylene may include polyethylene glycol / polypropylene glycol / polybutylene glycol-8 / 5 / 3 glycerin. The pH adjuster may contain one or more selected from acids and alkalis. The anti-inflammatory agent may contain one or more selected from glycyrrhetinic acid, glycyrrhizinic acid and derivatives thereof. The disinfectant may include isopropylmethylphenol. The colorant may contain one or more selected from natural dyes and tar dyes.

[0056] The surfactant may include one or more selected from anionic surfactants, nonionic surfactants, amphoteric surfactants, and cationic surfactants. The polyhydric alcohol may include one or more selected from dihydric alcohols, trihydric or higher alcohols, sugars, and sugar alcohols. The oil may contain one or more selected from linear or branched hydrocarbon oils, ester oils, and higher alcohols. The polysaccharide may include, for example, one or more selected from xanthan gum, cationized xanthan gum, diutan gum, welan gum, xylitol, erythritol, pullulan, and the like.

[0057] The organic solvent may include one or more selected from lower alcohols, aromatic alcohols, cellosolves, and carbitols. The lower alcohols may include one or two selected from ethanol and isopropyl alcohol. The aromatic alcohols may include one or two selected from benzyl alcohol and benzyloxyethanol. The cellosolves may include one or two selected from ethyl cellosolve and butyl cellosolve. The carbitols may include one or two selected from ethyl carbitol and butyl carbitol. The inorganic or organic salts may include one or two selected from sodium sulfate, sodium carbonate, sodium bicarbonate, potassium chloride, sodium chloride, magnesium chloride, and sodium citrate. The moisturizing component may contain one or more selected from sugars and derivatives thereof, amino acids and derivatives thereof, animal and plant protein derivatives, and animal and plant extracts.

[0058] The following supplementary notes are further disclosed regarding the above-described embodiment of the present invention. <1> A cleaning liquid discharge nozzle, The nozzle has a discharge plate with one or more through holes through which the liquid is discharged. the through-hole has a tapered shape in which the inner diameter decreases in the direction of ejection of the liquid, The nozzle for discharging a cleaning liquid, wherein the inner diameter of the discharge port of the through-hole is 10 μm or more and 200 μm or less.

[0059] <2> The inner diameter of the discharge port is 20 μm or more and 150 μm or less, preferably 20 μm or more and 110 μm or less. <1> 10. The cleaning liquid discharge nozzle according to claim 1 . <3> The inner diameter of the inlet of the through hole is 20 μm or more and 500 μm or less, preferably 50 μm or more and 400 μm or less, and more preferably 50 μm or more and 350 μm or less. <1> or <2> 10. The cleaning liquid discharge nozzle according to claim 1 . <4> the ratio (D1 / D2) of the inner diameter D1 of the discharge port to the inner diameter D2 of the inlet of the through hole is greater than 1.0 and not more than 40, preferably 1.1 or more and 20 or less, and more preferably 1.5 or more and 10 or less; <1> ~ <3> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <5> The length of the discharge flow path formed by the through holes is 100 μm or more and 3000 μm or less, preferably 200 μm or more and 2000 μm or less, and more preferably 200 μm or more and 1000 μm or less. <1> ~ <4> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <6> The discharge plate includes a thermoplastic resin. <1> ~ <5> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid.

[0060] <7> The liquid ejection nozzle preferably contains a thermoplastic resin in an amount of 50% by mass or more, more preferably 50% by mass or more and 100% by mass or less, and even more preferably 70% by mass or more and 100% by mass or less, based on the total mass of the nozzle. <1> ~ <6> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <8> The unit area (1 cm) of the discharge plate 2 The number of through holes per square centimeter is 20 per square centimeter. 2 More than 1500 pieces / cm 2 Less than 50 / cm, preferably 2 More than 1000 pieces / cm 2 More preferably, 100 particles / cm or less 2 More than 500 pieces / cm 2 The above-mentioned <1> ~ <7> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <9> the liquid discharge nozzle has a cylindrical base in which a large-diameter cylinder and a small-diameter cylinder having an inner diameter smaller than that of the large-diameter cylinder are connected to each other, and the small-diameter cylinder is connected to one axial side of the large-diameter cylinder; The opening of the large diameter cylinder on the opposite side of the small diameter cylinder in the axial direction is closed by the discharge plate. <1> ~ <8> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <10> A supply pump for supplying liquid is connected to the end of the small diameter cylinder opposite to the end of the large diameter cylinder in the axial direction. <9> 10. The cleaning liquid discharge nozzle according to claim 1 . <11> In the liquid discharge nozzle, the internal spaces of the large diameter cylinder and the small diameter cylinder communicate with each other in the discharge direction, and the internal spaces form a flow path for the liquid. <9> or <10> 10. The cleaning liquid discharge nozzle according to claim 1 .

[0061] <12> The small diameter cylinder is longer in the discharge direction than the large diameter cylinder. <9> ~ <11> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <13> a cross-sectional shape of the through hole along the ejection direction has a pair of tapered edges extending so as to converge toward a central axis of the ejection port, The pair of tapered edges are curved edges that curve toward the central axis of the ejection port. <1> ~ <12> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <14> the through hole has a tapered shape over the entire area in the discharge direction from the inlet to the discharge outlet; <1> ~ <13> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <15> the through-hole has a tapered portion and a non-tapered portion, and the tapered portion is formed closer to the discharge port than the non-tapered portion; <1> ~ <13> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <16> When the liquid discharge nozzle is viewed from above, the distance between the centers of the adjacent through holes is 0.1 mm or more and 3 mm or less, preferably 0.2 mm or more and 2 mm or less. <1> ~ <15> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid.

[0062] <17> When the liquid discharge nozzle is used to cleanse the skin, the inner diameter of the discharge port is 15 μm or more and 100 μm or less, preferably 20 μm or more and 80 μm or less, more preferably 30 μm or more and 70 μm or less, and even more preferably 40 μm or more and 60 μm or less. <1> ~ <16> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <18> When the liquid discharge nozzle is used to cleanse skin, the inner diameter of the inlet of the through hole is 20 μm or more and 500 μm or less, preferably 100 μm or more and 400 μm or less, more preferably 150 μm or more and 350 μm or less, and even more preferably 200 μm or more and 350 μm or less. <1> ~ <17> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <19> When the liquid discharge nozzle is used to clean the oral cavity, the inner diameter of the discharge port is 50 μm or more and 200 μm or less, preferably 60 μm or more and 150 μm or less, and more preferably 70 μm or more and 130 μm or less. <1> ~ <16> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <20> When the liquid discharge nozzle is used to clean the oral cavity, the inner diameter of the inlet of the through-hole is 70 μm or more and 700 μm or less, preferably 100 μm or more and 400 μm or less, more preferably 150 μm or more and 350 μm or less, and even more preferably 200 μm or more and 350 μm or less. <1> ~ <16> or <19> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <21> The discharge plate is a flat plate or a curved plate that is entirely or partially curved. <1> ~ <20> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <22> The front or rear surface of the ejection plate is a smooth surface or an uneven surface. <1> ~ <21> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid. <23> the ejection plate has a through-hole arrangement region in which the through-holes are formed and a non-through-hole arrangement region in which the through-holes are not formed, The area ratio of the through-hole arrangement region in the discharge plate is preferably 10% or more and 100% or less, more preferably 50% or more and 80% or less. <1> ~ <22> 10. The cleaning liquid discharge nozzle according to claim 1, wherein the nozzle is a nozzle for discharging a cleaning liquid.

[0063] <24> The aforementioned <1> ~ <23> A cleaning method using the cleaning liquid discharge nozzle according to any one of the above, A cleaning method comprising discharging a liquid from the discharge port of the through hole and applying the liquid to a portion of the object to be cleaned, thereby removing dirt from the surface of the object to be cleaned. <25> The distance between the discharge port and the area to be cleaned is set to 0.5 mm or more and 300 mm or less, preferably 1 mm or more and 100 mm or less, more preferably 1 mm or more and 50 mm or less, and even more preferably 1 mm or more and 30 mm or less, to remove dirt from the surface of the area to be cleaned. <24> The cleaning method described in <26> The liquid is ejected at a speed of 10 m / sec or more and 40 m / sec or less, preferably 12 m / sec or more and 35 m / sec or less, more preferably 15 m / sec or more and 30 m / sec or less to remove dirt from the surface of the object to be cleaned. <24> or <25> The cleaning method described in

[0064] <27> The supply pressure of the liquid is set to 0.05 MPa or more and 10 MPa or less, preferably 0.1 MPa or more and 5 MPa or less, more preferably 0.1 MPa or more and 1 MPa or less, to remove dirt from the surface of the object to be cleaned. <24> ~ <26> 10. The cleaning method according to claim 1, wherein the cleaning agent is a fluorine-containing compound. <28> The liquid discharged from the through-hole is brought into contact with the part to be cleaned of the object to be cleaned in a state including one or more continuous flows. <24> ~ <27> 10. The cleaning method according to claim 1, wherein the cleaning agent is a fluorine-containing compound. <29> The liquid discharged from the through-hole is brought into contact with the part to be cleaned of the object to be cleaned in a state where the liquid includes a substantially linear continuous flow. <24> ~ <28> 10. The cleaning method according to claim 1, wherein the cleaning agent is a fluorine-containing compound. <30> The substantially linear continuous flow has a ratio J represented by the following formula of 10 or more: <29> The cleaning method described in Ratio J = continuous length of liquid flow / width of liquid flow <31> The viscosity of the liquid is 0.5 mPa·s or more and 40 mPa·s or less, preferably 1 mPa·s or more and 30 mPa·s or less. <24> ~ <30> 10. The cleaning method according to claim 1, wherein the cleaning agent is a fluorine-containing compound. <32> The total discharge flow rate of the liquid is 10 mL / min or more and 1000 mL / min or less, preferably 20 mL / min or more and 500 mL / min or less, and more preferably 40 mL / min or more and 300 mL / min or less. <24> ~ <31> 10. The cleaning method according to claim 1, wherein the cleaning agent is a fluorine-containing compound.

[0065] <33> The site to be cleaned is one or more selected from keratinous materials and teeth. <24> ~ <32> 10. The cleaning method according to claim 1, wherein the cleaning agent is a fluorine-containing compound. <34> The keratinous material includes one or more areas selected from skin, scalp, hair, and nails, and preferably, the skin includes skin in one or more areas selected from face, arms, hands, feet, and back; The liquid discharge nozzle has a flow path for the liquid therein. <33> The cleaning method described in <35> The aforementioned <1> ~ <23> Use of the liquid discharge nozzle according to any one of the above for removing dirt from the surface of an object to be cleaned. [Example]

[0066] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0067] Examples 1 to 9 A nozzle having a configuration similar to that of the nozzle 1 shown in FIG. 1 was manufactured. The through holes 21 of the nozzle were arranged in the same pattern as that shown in FIG. 3. In Examples 1 to 9, the inner diameters of the outlet and inlet of each through hole 21 of the nozzle, the length of the outlet flow path formed by the through holes 21, the number N of through holes per unit area, and the area ratio of the through hole arrangement region 21R in the outlet plate 2 were varied as shown in Table 1. All of the through holes 21 had a tapered shape in which the inner diameter decreased in the direction of liquid ejection. More specifically, the pair of tapered edges 21a, 21b of the through hole 21 were curved edges that curved toward the central axis of the outlet 23 over the entire area in the ejection direction from the inlet to the outlet (see FIG. 2(a)). The number N of through holes per unit area was calculated using the method described above. A sheet containing 100% by mass of polyethylene terephthalate, a thermoplastic resin, was used as the base sheet, and the outlet plate 2 was formed by laser processing the base sheet from the side where the inlet was formed. The base 4 was manufactured using the same material as the discharge plate 2. The discharge plate 2 was joined by thermal fusion to the large diameter cylinder 46 of this base 4. In the obtained nozzle 1, the inner diameter of the through hole 21 in the discharge plate 2 decreased in the discharge direction.

[0068] Comparative Example 1 The discharge plate 2 of Example 1 was inverted and joined to the large-diameter cylinder 46. That is, the discharge plate 2 was joined so that the through-hole 21 had an inverse tapered shape in which the inner diameter increased in the discharge direction. Except for this, the nozzle was manufactured in the same manner as in Example 1.

[0069] Comparative Examples 2 and 3 A nozzle was prepared having a through-hole with a constant inner diameter and a straight shape in cross section. In Comparative Example 2, a nozzle with two through-holes was prepared, and in Comparative Example 3, a nozzle with one through-hole was prepared. In Table 1, "-" indicates that no evaluation was performed. Comparative Examples 4 and 5 Except for using a sheet containing 100% by mass of polylactic acid as the thermoplastic resin, a nozzle was manufactured in the same manner as in Comparative Example 1. Table 1 shows the thickness of the nozzle at the portion where the through holes were formed, as the length of the discharge flow path formed by the through holes 21. Comparative Example 6 A nozzle was manufactured in the same manner as in Example 1, except that the inner diameter of the discharge port was set to 250 μm.

[0070] [Straight-line running evaluation] The nozzles obtained in the examples and comparative examples were evaluated for straightness, that is, whether the liquid could be applied to the object to be cleaned with precision, by the following method. A syringe with a capacity of 1 mL or more was prepared as a liquid supply unit. Water was used as the liquid. The syringe was filled with water, and the nozzle obtained in the Examples and Comparative Examples was connected to the tip of the syringe. Water was ejected so that the ejection direction was parallel to the horizontal direction. The ejection operation was performed so that the ejection speed was 10 m / sec or more. The liquid was photographed 5 seconds after ejection, and the inclinations of five water streams randomly selected from the image were calculated. The average value was taken as the inclination of the water stream, and the straightness was evaluated according to the following criteria. The inclination of the water stream refers to the angle between the water stream and a line parallel to the horizontal direction, with the line being taken as 0°. Evaluation criteria A: The water flow gradient is less than 15 degrees B: The water flow gradient is between 15 degrees and 30 degrees C: The water flow slope is 30 degrees or more

[0071] [Table 1]

[0072] As is clear from the results shown in Table 1, when the through-holes have a tapered shape in which the inner diameter decreases in the direction of the liquid ejection and the inner diameter of the ejection port is between 10 μm and 200 μm, the ejected liquid flows in a straight line. This suppresses the diffusion of the water flow and is expected to enable multiple water streams to be directed accurately at the desired position on the area to be cleaned. The nozzle of Comparative Example 6 was rated A for straightness (see Table 1), but each of the Examples was superior to the nozzle of Comparative Example 6 in terms of splashing of liquid L during cleaning and damage to the area to be cleaned (see, for example, Tests 10 and 15 in Table 4).

[0073] [Skin Cleansing Tests 1 to 17] The nozzles obtained in Examples 1, 2, 4 to 9, Comparative Examples 1, 2, and 4 to 6 were evaluated for cleaning performance and damage to the area to be cleaned using the following methods. Specifically, by achieving both [evaluation of cleaning performance] and [evaluation of splashing of liquid during cleaning], it was shown that the nozzles can efficiently clean dirt from the surface of the object to be cleaned, and by achieving an excellent [evaluation of damage to the area to be cleaned], it was shown that the nozzles are safe.

[0074] Areas to be cleaned A 30 mm square area of ​​skin on the inner side of a human forearm was used as the area to be cleansed. The skin color Ea of the bare skin before the attachment of model comedo sebum and before cleansing was measured using a spectrophotometer (Konica Minolta, Inc., "CM-600d"). -Model stain formation A model comedo sebum with the composition shown in Table 2, in which carbon black was dispersed, was prepared. 30 μg of the model comedo sebum was applied to the area to be cleansed, and then excess model comedo sebum from the surface was scraped off six times with a 15 mm wide spatula. The model comedo sebum remaining on the area to be cleansed was allowed to dry for 30 minutes to form a model stain. After the model stain was formed, the skin color Eb (100% value) after the model stain was formed was measured in the same manner using the spectrophotometer described above. Cleaning method The nozzles obtained in the examples and comparative examples were connected to a liquid supply unit that supplied liquid. The nozzle was moved so that the liquid L ejected from the nozzle hit the entire target area evenly, and cleaning was performed for 10 seconds to remove dirt from the target area. When cleaning was performed using the nozzles obtained in each example, the liquid L ejected from the through-holes 21 contacted the target area of ​​the object to be cleaned in a state where it included a substantially linear continuous flow. At this time, a sensory evaluation of the feeling of use was performed based on the pain felt when the liquid L hit the area to be cleaned. The distance between the discharge port and the area to be cleaned was 5 mm. The discharge speed, supply pressure, state of the discharged liquid, and proportion J of the liquid L are shown in Tables 3 and 4. The proportion J was calculated according to the method described above. In Tests 1 to 16, an aqueous solution containing 2% by mass of a surfactant (polyoxyethylene (2) lauryl ether sodium sulfate, "EMAL 227" manufactured by Kao Corporation) was used as Liquid L. In Test 17, an aqueous solution containing 2% by mass of a surfactant (polyoxyethylene sorbitan monolaurate (20E.O.), "RHEODOL TW-L120" manufactured by Kao Corporation) was used as Liquid L. Next, the area to be cleaned was rinsed by pouring 40 mL of tap water over it. Then, it was air-dried. The skin color Ec of the area to be cleaned after air-drying was measured in the same manner using the spectrophotometer described above to obtain the skin color Ec after cleaning.

[0075] The viscosity of the undiluted Liquid L used in Tests 1 to 16 was 2.5 mPa·s at 30°C. The viscosity of the undiluted Liquid L used in Test 17 was 2.9 mPa·s at 30°C. The viscosity of the undiluted Liquid L was measured using a B-type viscometer (Toki Sangyo Co., Ltd., TVB-10 model viscometer, measurement conditions: rotor No. M1, 60 rpm, 30°C, 60 seconds).

[0076] [Table 2]

[0077] [Table 3]

[0078] [Table 4]

[0079] [Total discharge flow rate] The mass of the liquid L discharged from the nozzle is measured, and the mass is divided by the specific gravity of the liquid L and the discharge time, and the value converted to a value per unit time (min) is taken as the total discharge flow rate. The discharge time is 10 seconds.

[0080] [Evaluation of cleaning ability] Based on the cleaning rate E obtained by the following formula, the cleaning ability was evaluated in four stages according to the following criteria. Cleansing rate E (%) = [1 - (bare skin color Ea - skin color after cleaning Ec) / (bare skin color Ea - skin color after model soiling Eb)] x 100 Evaluation criteria A: Cleaning rate E is 80% or more. B: Cleaning rate E is 60% or more but less than 80%. C: Cleaning rate E is 40% or more but less than 60%. D: Cleaning rate E is less than 40%.

[0081] [Evaluation of liquid splashing during cleaning] The nozzles obtained in Examples 1, 2, 4 to 9, Comparative Examples 1, 2, and 4 to 6 were evaluated for splashing of liquid during cleaning by the following method. Bioskin (manufactured by Bealux, cheek skin model, Φ50 mm) was attached to the center of a piece of drawing paper (2912 mm x 3084 mm) with double-sided tape. The nozzle obtained in the examples and comparative examples was connected to a liquid supply unit that supplies liquid. The liquid ejected from the nozzle was applied to the center of the Bioskin for 10 seconds. The distance from the nozzle to the center of the Bioskin was 5 mm.

[0082] The liquid that had splashed around before hitting the Bioskin and the liquid L that had splashed around after hitting the Bioskin were observed. The distance S between the center of the Bioskin and the liquid L that had splashed to the farthest point from the center of the Bioskin and adhered to the drawing paper was measured. The shorter the distance S, the less liquid splashed during cleaning.

[0083] [Evaluation of damage to the area to be cleaned] The pain felt when the liquid flow hit the skin of the area being cleansed was evaluated using the three-level scale below. These evaluations were carried out by two Japanese women in their 30s and 40s. If the evaluation results of the two women differed, the evaluation result of the woman who felt more pain is shown. Evaluation criteria A: I barely feel any pain B: I feel some pain C: Feeling pain

[0084] [Oral Cleansing Tests 18 to 20] The nozzles obtained in Examples 2, 3, and Comparative Example 3 were evaluated for cleaning performance and safety using the following methods. Specifically, the nozzles were found to be excellent in [model plaque removal evaluation] and had small values ​​for [evaluation by discharge load measurement], indicating that they could efficiently clean dirt from the surface of the object to be cleaned, and excellent in [evaluation of usability when the liquid flow was applied to teeth or gums], indicating that they were safe. The [total discharge flow rate] was calculated as described above. [Model plaque removal evaluation] Artificial plaque (artificial dental plaque for model use) manufactured by Nissin Corporation was evenly applied to the surface of a circular area (10 mm diameter) on a flat acrylic plate. After leaving it for approximately 5 minutes, liquid was ejected from each nozzle so that a water stream was directed at the artificial plaque, and cleansing performance was evaluated. The measurement conditions were: distance between the ejection port and the area to be cleaned: 10 mm, ejection time: 5 seconds, liquid: water, ejection pressure: 0.5 MPa. The evaluation criteria for cleaning performance were as follows: The results are shown in Table 5. To evaluate cleansing, the area where the artificial plaque had been applied was photographed with a digital camera after cleaning. The image was analyzed using the image analysis software WinROOF to determine the area of ​​the artificial plaque that had been cleaned.

[0085] The nozzles obtained in Example 2, Example 3, and Comparative Example 3 were evaluated for damage to the area to be cleaned by the following method. [Evaluation of usability when liquid flow is applied to teeth or gums] Eight adults in their 30s to 50s served as subjects. They were asked to clean their teeth or gums using each of the nozzles of Example 2, Example 3, and Comparative Example 3. They were asked to evaluate the feeling of use when the liquid flow was applied. The cleaning conditions were: discharge distance: 10 mm, discharge time: 5 seconds, liquid: water, discharge pressure: 0.5 MPa. The evaluation was based on a majority vote of the highest score (evaluation result) of each subject, and the evaluation criteria were as follows. The results are shown in Table 5. A: It causes less irritation to the gums and feels comfortable when used. B: I feel some irritation to my gums. C: I feel a strong irritation to my gums.

[0086] [Evaluation by discharge load measurement] A digital force gauge (ZTS-20N manufactured by Imada Co., Ltd.) was used, and a flat plate (40 mm x 40 mm) was attached to the tip of the measuring part. The maximum discharge load was measured when a water jet was discharged from the nozzles obtained in Example 2, Example 3, and Comparative Example 3. The measurement conditions were discharge distance: 10 mm, discharge time: 5 s, liquid: water, and discharge pressure: 0.5 MPa. With the discharge direction F aligned vertically, the water jet was discharged from the nozzle toward the flat plate. The load was measured. The results are shown in Table 5.

[0087] [Table 5]

[0088] As is clear from the results shown in Tables 3 to 5, the nozzles of Examples 1 to 9 ejected water in a more straight line than the nozzles of Comparative Examples 1 to 5, allowing the water to be accurately directed at the area to be cleaned. Furthermore, in addition to excellent cleansing performance, there was less splashing of Liquid L, minimizing the impact on areas other than the area to be cleaned. Consequently, damage to the area to be cleaned was reduced. Compared to Comparative Example 6, the nozzles of Examples 1 to 9 were evaluated as having the same straight line, but there was less splashing of Liquid L. The above results demonstrate that the nozzle of the present invention and the cleaning method using the nozzle can accurately apply the ejected liquid to dirt on the surface of the object to be cleaned, and can safely and efficiently clean dirt from the surface of the object to be cleaned. [Explanation of symbols]

[0089] 1 nozzle 2 Discharge plate 21 Through hole 24 Tapered section

Claims

1. A cleaning liquid discharge nozzle, a discharge plate having one or more through holes through which the liquid is discharged; the through-hole has a tapered shape in which the inner diameter decreases in the direction of ejection of the liquid, The nozzle for discharging a cleaning liquid, wherein the inner diameter of the discharge port of the through hole is 10 μm or more and 200 μm or less.

2. 2. The nozzle for discharging a cleaning liquid according to claim 1, wherein the inner diameter of the inlet of the through-hole is 20 [mu]m or more and 500 [mu]m or less.

3. 2. The cleaning liquid discharge nozzle according to claim 1, wherein the length of the discharge flow path formed by the through-hole is 100 [mu]m or more and 3000 [mu]m or less.

4. 2. The cleaning liquid discharge nozzle according to claim 1, wherein the liquid discharge nozzle contains a thermoplastic resin in an amount of 50% by mass or more relative to the total mass of the nozzle.

5. The unit area (1 cm ２ The number of through holes per square centimeter is 20 per square centimeter. ２ More than 1500 pieces / cm ２ 2. The cleaning liquid discharge nozzle according to claim 1, wherein:

6. A cleaning method using the cleaning liquid discharge nozzle according to claim 1, A cleaning method comprising discharging a liquid from the discharge port of the through hole and applying the liquid to a portion of the object to be cleaned, thereby removing dirt from the surface of the object to be cleaned.

7. The cleaning method according to claim 6, wherein the distance between the discharge port and the part to be cleaned is set to 0.5 mm or more and 300 mm or less to remove dirt from the surface of the part to be cleaned.

8. 7. The cleaning method according to claim 6, wherein the liquid is ejected at a speed of 10 m / sec or more and 40 m / sec or less to remove dirt from the surface of the object to be cleaned.

9. The cleaning method according to claim 6, wherein the supply pressure of the liquid is set to 0.05 MPa or more and 10 MPa or less to remove dirt from the surface of the object to be cleaned.

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