阅读说明：本技术 覆膜的制造装置 (Film manufacturing device ) 是由 石田拓也 福田郁夫 平野乔大 东城武彦 于 2019-10-03 设计创作，主要内容包括：本发明的课题在于提供一种能够容易地形成由纤维的堆积物构成的覆膜的装置。覆膜的制造装置(1)具有设置有壳体(10)的静电喷射部(P1)。在壳体(10)内具有：喷嘴(16)、电极(20)、空气流产生部(21)、空腔部(22)和空气喷出口(24)。空腔部(22)位于喷嘴(16)与空气流产生部(21)之间,且与空气流产生部(21)邻接。空腔部(22)与空气喷出口(24)邻接。壳体(10)构成为人能够用手抓持。沿着液状组合物的排出方向观察静电喷射部(P1)时,喷嘴(16)的前端位于静电喷射部(P1)的最靠端部的位置。(The invention provides a device capable of easily forming a coating film composed of fiber deposits. A film-manufacturing device (1) is provided with an electrostatic spraying section (P1) provided with a housing (10). The inside of a housing (10) is provided with: a nozzle (16), an electrode (20), an air flow generating portion (21), a cavity portion (22), and an air ejection port (24). The cavity section (22) is located between the nozzle (16) and the airflow generation section (21), and is adjacent to the airflow generation section (21). The cavity section (22) is adjacent to the air outlet (24). The housing (10) is configured to be manually graspable by a person. When the electrostatic discharge part (P1) is viewed in the discharge direction of the liquid composition, the tip of the nozzle (16) is positioned at the position closest to the end of the electrostatic discharge part (P1).)

1. A device for producing a coating, which electrostatically ejects a liquid composition containing a fiber-forming polymer directly onto a surface of an object to form a coating made of a deposit containing fibers on the surface, characterized in that:

the manufacturing apparatus includes an electrostatic spray part having a housing,

within the housing:

a nozzle for discharging the liquid composition;

an electrode for applying a voltage to the liquid composition passing through the nozzle;

an air flow generating part located behind the nozzle;

a cavity portion located between the nozzle and the air flow generating portion and adjacent to the air flow generating portion; and

an air ejection port which is located around the nozzle and ejects an air flow passing through the cavity portion,

the housing is configured to be manually graspable by a person.

2. The manufacturing apparatus according to claim 1, wherein:

the cavity portion is adjacent to the air ejection port.

3. The manufacturing apparatus according to claim 1 or 2, wherein:

by making the volume V (cm) of the air flow generated by the air flow generating part³) Relative to flow F (cm)³A value of V/F (min), which is a ratio of/min), is 0.001min to 0.5min, and the cavity section has a temporary accumulation action of the air flow.

4. The manufacturing apparatus according to any one of claims 1 to 3, wherein:

when the electrostatic discharge unit is viewed in the discharge direction of the liquid composition, the tip of the nozzle is positioned at the end of the electrostatic discharge unit.

5. The manufacturing apparatus according to any one of claims 1 to 4, wherein:

the casing has a conduit including a liquid composition flow path for allowing the liquid composition to reach the tip of the nozzle via the electrode,

a portion of the tubing is present in the cavity.

6. The manufacturing apparatus according to claim 5, wherein:

the outer periphery of the pipeline is surrounded by the space of the cavity portion, and the cavity portion is located further rearward than the pipeline.

7. The manufacturing apparatus according to any one of claims 1 to 6, wherein:

the length of the air ejection port in the direction of the air flow is 10mm or less.

8. The manufacturing apparatus according to any one of claims 1 to 7, wherein:

the housing is sized and/or shaped to be grasped by a person with one hand.

9. The manufacturing apparatus according to any one of claims 1 to 7, wherein:

the housing has a handle that a person can grasp with one hand.

10. The manufacturing apparatus according to any one of claims 1 to 9, wherein:

the discharge amount of the liquid composition is adjusted to be 0.01g/min to 2g/min, and the discharge amount of the air flow from the air discharge port is adjusted to be 100cm³More than min and 50000cm³Less than min.

11. The manufacturing apparatus according to any one of claims 1 to 10, wherein:

the voltage applied to the liquid composition by the electrode is 1kV or more and 40kV or less.

12. The manufacturing apparatus according to any one of claims 1 to 11, wherein:

further comprises a fixed type containing part which is separated from the electrostatic spraying part,

the fixed storage part comprises:

a storage section capable of storing the liquid composition;

a liquid feeding unit for supplying the liquid composition to the nozzle; and

a power supply for applying a voltage to the electrodes,

the electrostatic spray unit and the stationary storage unit are connected by a pipeline for transporting the liquid composition and a wire for electrically connecting the electrode and the power supply.

13. The manufacturing apparatus according to any one of claims 1 to 12, wherein:

with a single said cavity portion.

14. The manufacturing apparatus according to any one of claims 1 to 13, wherein:

the volume of the cavity part is 10cm³Above and 1000cm³The following.

15. The manufacturing apparatus according to any one of claims 1 to 14, wherein:

the electrostatic spraying section includes an electrospinning device.

16. The manufacturing apparatus according to any one of claims 1 to 15, wherein:

the ratio of the average value Q2 of the cross-sectional areas of the outer edge of the cavity in the cross-section of the outer edge of the cavity in the direction orthogonal to the direction of the air flow generated by the air flow generating section at positions other than the position adjacent to the air flow generating section to the cross-sectional area Q1 at the position adjacent to the air flow generating section, that is, the value Q2/Q1, is 70% to 120%.

17. The manufacturing apparatus according to any one of claims 1 to 16, wherein:

the average value of the area of the cross section of the airflow generation part in the direction orthogonal to the direction of the airflow generated by the airflow generation part is set as Q3,

when the area of the cross section at the position adjacent to the airflow generation part in the cross section of the outer edge of the cavity part in the direction orthogonal to the direction of the airflow generated by the airflow generation part is defined as Q1,

the value of Q3/Q1 is 80% or more and 170% or less.

18. The manufacturing apparatus according to any one of claims 1 to 17, wherein:

a ratio of a total of areas of the air ejection ports to an area Q1 of a cross section at a position adjacent to the air flow generation portion in a cross section of an outer edge of the cavity portion in a direction orthogonal to a direction of the air flow generated by the air flow generation portion is 1.5% or more and 70% or less.

19. A method for producing a coating film, characterized by:

the manufacturing apparatus for a coating film according to any one of claims 1 to 18, wherein a liquid composition containing a fiber-forming polymer is directly electrostatically sprayed onto a surface of an object while an air stream is ejected from an air ejection port, and a coating film composed of a deposit containing fibers is formed on the surface.

Technical Field

The present invention relates to a device for producing a coating film made of a deposit containing fibers.

Background

As a conventional technique for forming a coating by spinning fibers by an electrostatic discharge method, for example, a technique described in patent document 1 is known. In this document, in an electrospinning device for producing a covering body from a liquefied polymer, an injector for injecting the liquefied polymer and a ring-shaped electrode are provided in a cavity so that polymer fibers formed from the liquefied polymer move in the cavity. The cavity is open at the front and rear, and a blower is provided at the rear opening. The polymer fibers are transported by the air flow generated by the blower moving in the cavity, whereby the polymer fibers are released outside the cavity through the front opening portion.

Documents of the prior art

Patent document

Patent document 1, Japanese patent laid-open publication No. 2004-525272

Disclosure of Invention

The present invention provides a manufacturing device for electrostatically spraying a liquid composition containing a fiber-forming polymer directly onto a surface of an object to form a coating film composed of a deposit containing fibers on the surface.

The manufacturing apparatus preferably includes an electrostatic spray section having a housing.

The housing preferably has a nozzle for ejecting the liquid composition.

Preferably, an electrode for applying a voltage to the liquid composition passing through the nozzle is provided in the housing.

Preferably, an air flow generating portion located rearward of the nozzle is provided in the housing.

Preferably, the housing has a cavity portion between the nozzle and the air flow generating portion and adjacent to the air flow generating portion.

Preferably, the housing has an air discharge port located around the nozzle and discharging the air flow passing through the cavity.

The housing is configured to be manually graspable by a person.

The present invention also provides a method for producing a coating, which comprises using the above-described apparatus for producing a coating, while jetting an air flow from an air jetting port, electrostatically jetting a liquid composition containing a fiber-forming polymer directly onto a surface of an object, and forming a coating composed of a deposit containing fibers on the surface.

Drawings

Fig. 1 is a schematic view showing an embodiment of a film manufacturing apparatus according to the present invention.

Fig. 2 is a schematic view showing another embodiment of the film manufacturing apparatus of the present invention.

Detailed Description

In the technique described in patent document 1, polymer fibers formed of liquefied polymer injected from an injection machine move in a cavity and are discharged to the outside of the cavity by a ring-shaped electrode provided in the cavity. The polymer fiber moves within the cavity, thereby causing the polymer fiber to easily adhere to the inner wall of the cavity, in which case the cavity may be clogged with the polymer fiber. As a result, it is not easy to smoothly form a target coating film in the technique described in this document.

The present invention relates to an improvement in a manufacturing apparatus for forming a coating film by an electrostatic discharge method.

The present invention will be described below based on preferred embodiments with reference to the accompanying drawings. The present invention relates to an apparatus for forming a coating film made of a deposit containing fibers on a surface of an object by directly applying a liquid composition containing a fiber-forming polymer to the surface of the object. As a method of forming the coating film, an electrostatic discharge method is employed in the present invention. The electrostatic discharge method is a method in which a liquid composition is charged by applying a positive or negative high voltage to the composition, and the charged composition is discharged to an object. The ejected liquid composition spreads in the space while being repeatedly micronized by coulomb repulsion, and during this process or after adhering to the object, a coating film composed of a deposit containing fibers is formed on the surface of the object by drying the solvent which is a volatile substance. Therefore, the electrostatic spraying method by the liquid composition discharge using the apparatus of the present invention is also referred to as an electrospinning method.

The object to be coated by the electrostatic discharge method is not particularly limited. For example, a coating film can be formed in close contact with the skin of a human being, or the surface of an object having irregularities, such as a wall, tableware, tree branches, or leaves. Here, the irregularities include visually recognizable irregularities and irregularities that are not easily recognized like skin furrows. In addition, from the viewpoint of the porosity of the coating film and the appropriate water-vapor permeability close to the human stratum corneum, the human skin is preferably used as the object, and the body is preferably used as the object.

Fig. 1 shows an embodiment of a film manufacturing apparatus according to the present invention. The apparatus 1 shown in the figure is composed of an electrostatic spray part P1 as an electrospinning apparatus having a casing 10. Within the housing 10 there is a low voltage power supply 11. The low-voltage power supply 11 is a power supply capable of generating a voltage of several V to several tens V. For the purpose of improving the mobility of the device 1, the low-voltage power supply 11 is preferably constituted by 1 or 2 or more batteries. In addition, by using a battery as the low-voltage power supply 11, there is an advantage that it can be easily replaced as needed. An AC adapter or the like can also be used as the low-voltage power supply 11 instead of the battery.

Also within the housing 10 of the device 1 is a high voltage power supply 12. The high-voltage power supply 12 is electrically connected to the low-voltage power supply 11, and includes a circuit (not shown) for boosting the voltage generated by the low-voltage power supply 11 to a high voltage. The booster circuit is generally constituted by a transformer, a capacitor, a semiconductor element, and the like.

Also present in the housing 10 of the device 1 is an auxiliary circuit 13. The auxiliary circuit 13 is interposed between the low-voltage power supply 11 and the high-voltage power supply 12, and has a function of adjusting the voltage of the low-voltage power supply 11 to stably operate the high-voltage power supply 12. The auxiliary circuit 13 also has a function of controlling the rotation speed of a motor provided in a micro gear pump 14 described later. By controlling the rotation speed of the motor, the supply amount of the liquid composition from the liquid composition storage unit 15 described later to the micro gear pump 14 can be controlled. A switch SW is provided between the auxiliary circuit 13 and the low-voltage power supply 11, and the device 1 can be operated/stopped by turning on/off the switch SW.

Also within the housing 10 of the device 1 is a nozzle 16. The nozzle 16 is made of a nonconductive material such as plastic, rubber, or ceramic, and is shaped to discharge the liquid composition from the tip thereof. A minute space through which the liquid composition flows is formed in the nozzle 16 along the longitudinal direction of the nozzle 16. The size of the cross section of the minute space is preferably 100 μm or more and 1000 μm or less in diameter. The nozzle 16 communicates with the micro gear pump 14 via a line 17. The conduit 17 is typically constructed of a non-conductive material. The pipe 17 connects the liquid composition storage 15 and the nozzle 16 via the micro gear pump 14.

An electrode 20 is provided in the flow space of the liquid composition provided in the nozzle 16. The electrode 20 is used to apply a voltage to the liquid composition passing through the nozzle 16 to charge the liquid composition. The electrode 20 is formed of a linear body extending in the flowing direction of the liquid composition. The electrode 20 can have a linear or needle-like shape. The thickness of the electrode 20 is such that the flow of the liquid composition through the nozzle 16 is not hindered. When the cross-sectional area of the flow space of the liquid composition provided in the nozzle 16 is S1 and the cross-sectional area of the electrode is S2, S2 is preferably 0.05% to 2% of S1. The length of the electrode 20 is not critical in the present invention, and is sufficient as long as it can impart a sufficient charge to the liquid composition flowing through the nozzle 16.

The electrode 20 is made of a conductor such as a metal. The electrode 20 is electrically connected to the high voltage power supply 12. This enables a high voltage to be applied to the electrode 20. At this time, in order to prevent an excessive current from flowing when the human body is in direct contact with the electrode 20, the electrode 20 and the high-voltage power supply 12 are electrically connected via the current limiting resistor 19.

The micro gear pump 14 communicating with the nozzle 16 through the pipe 17 functions as a supply device for supplying the liquid composition stored in the storage portion 15 to the nozzle 16. The micro gear pump 14 operates upon receiving power supply from the low voltage power supply 11. The micro gear pump 14 is configured to supply a predetermined amount of the liquid composition to the nozzle 16 under the control of the auxiliary circuit 13.

The micro gear pump 14 is connected to the housing 15 via a pipe 18. The storage section 15 stores a liquid composition. The housing 15 is preferably in the form of a cassette that is replaceable.

The housing 10 of the device 1 also has an air flow generating portion 21. The airflow generating portion 21 is located behind the nozzle 16 in the discharge direction of the liquid composition (the direction indicated by the symbol X in fig. 1). The air flow generating unit 21 takes outside air into the casing 10 and generates an air flow along the discharge direction X of the liquid composition. For this purpose, the airflow generating portion 21 is constituted by, for example, a fan or a blower. The airflow generation unit 21 operates by receiving power supply from the low-voltage power supply 11.

The cavity portion 22 is located between the nozzle 16 and the air flow generating portion 21. The cavity portion 22 is adjacent to the airflow generation portion 21. In addition, the cavity portion 22 is also adjacent to the nozzle 16. That is, it is preferable that no member that extends in a direction orthogonal to the direction of the air flow and partitions the cavity portion 22 is provided between the cavity portion 22 and the air flow generating portion 21. Similarly, it is preferable that no member for partitioning the cavity portion 22 is provided between the cavity portion 22 and the nozzle 16. The cavity 22 is preferably a single (single) space formed by the tubular body 25 having both ends open. The airflow generating unit 21 is located at one end of the opening of the tubular body 25. On the other hand, the air ejection portion 23 is located at the other end of the opening of the cylindrical body 25. The cavity section 22 has a temporary accumulation function of the airflow generated by the airflow generation section 21. For this purpose, it is desirable that the cavity portion 22 has a sufficiently large volume with respect to the flow rate of the air flow generated by the air flow generating portion 21. The cylindrical body 25 is preferably a space in that the inside thereof is completely formed, in order to enhance the action of temporarily accumulating the air flow by the hollow portion 22, but some components may be present in the hollow portion 22 within a range not to impair the action. In the embodiment shown in fig. 1, a part of the nozzle 16, a part of the conduit 17, and a part of the circuit for applying a voltage to the electrode 20 are present in the cavity portion 22.

In the embodiment shown in fig. 1, the device 1 has a single cavity portion 22. Instead of the single cavity portion 22, a plurality of cavity portions in which a plurality of spaces divided by a partition member (not shown) are arranged in parallel in the discharge direction X of the liquid composition may be used. Considering that the cavity 22 has a function of temporarily accumulating the air flow, the embodiment in which the cavity 22 is a single body is advantageous in that the function can be reliably exhibited. A plurality of cavity sections in which a plurality of spaces divided by a partition member (not shown) are arranged in series along the discharge direction X of the liquid composition may be used. When the partition member (not shown) is provided, the partition member is preferably provided in parallel with the air flow from the viewpoint of reducing the pressure loss by rectifying the air flow and the viewpoint of increasing the air volume.

The air discharge portion 23 located at the end of the opening of the tubular body 25 discharges the air having passed through the cavity portion 22 in the discharge direction X of the liquid composition. The air ejection portion 23 has a short flow path 23a formed by 1 or 2 or more through holes extending in the direction of the air flow. The air flow is ejected through the air ejection port 24 as the open end of the short flow path 23 a. The cross-sectional area of the short flow path 23a constituting the air ejection portion 23 is a constant value. The air ejection port 24 is configured such that the direction of the air flow ejected from the air ejection port 24 is directed toward the discharge direction of the liquid composition discharged from the nozzle 16. The air ejection ports 24 are located around the nozzle 16. When the air ejection portion 23 is provided with a plurality of air ejection ports 24, the through holes are preferably arranged uniformly around the nozzle 16 in view of ejecting a stable air flow. As shown in fig. 1, the air ejection portion 23 (short flow path 23a) and the cavity portion 22 are adjacent to each other without any member provided therebetween. For example, a pipe line for communicating the cavity 22 and the air ejection unit 23 (short flow path 23a) is not interposed therebetween.

It is advantageous for the device 1 to have a shape that increases the flow rate of the air flow circulating inside the cavity portion 22 by using the principle of orifice (orifice). For this purpose, it is advantageous that the opening area of the air ejection port 24 at the end of the cylindrical body 25 defining the cavity portion 22 is smaller than the cross-sectional area of the cavity portion 22. This field can be referred to as the "throttle" of the air flow.

The housing 10 constituting the device 1 is configured to be grasped by a human hand. In detail, from the viewpoint of good operability, the housing 10 is preferably sized and/or shaped to be grasped by a person with one hand. In order to make the casing 10 "a size that can be gripped with one hand", for example, the mass of the device 1 is preferably 2kg or less, the maximum length of the casing 10 along the discharge direction X of the liquid composition is preferably 40cm or less, or the volume of the casing 10 is preferably 3000cm³The following. In order for the housing 10 to be in a "one-handed graspable shape", for example, as shown in fig. 1, the housing 10 preferably has a grip 26 that a person can grasp with one hand. In particular, when the handle 26 is provided with the switch SW for operating the device 1, the operability is further improved, which is advantageous.

When the device 1 is operated, the user holds the device 1 with a hand and directs the tip 16a of the nozzle 16 to an application site where electrostatic discharge is performed. In this state, the switch of the apparatus 1 is turned on, and the electrostatic discharge process is performed. By applying a power source to the device 1, an electric field is generated between the electrode 20 and the application site. For example, when a positive voltage is applied to the electrode, the applicable site becomes a negative electrode. When an electric field is generated between the electrode 20 and the application site, the liquid composition in the form of droplets discharged from the tip 16a of the nozzle 16 flies in space toward the application site along the electric field. When a volatile solvent is evaporated from a liquid composition flying in a space in a charged state (described later), the charge density of the surface of the liquid composition becomes excessive, and the fiber-forming polymer spreads in the space while repeatedly being refined by coulomb repulsion, and reaches the application site. At this time, by appropriately adjusting the viscosity of the liquid composition, the composition discharged in the form of droplets can reach the application site. Alternatively, while the volatile substance as the solvent is being discharged into the space, the fiber-forming polymer as the solute is solidified by volatilizing the volatile substance from the liquid droplets, and the fiber can be formed while being stretched and deformed by a potential difference to be deposited at the application site. For example, when the viscosity of a liquid composition is increased, the composition is easily deposited in the form of fibers on an application site. Thus, a porous coating film made of a deposition of fibers can be formed on the surface of the applicable portion. The porous coating film made of a deposit of fibers may be formed by adjusting the distance between the nozzle 16 and the application site and the voltage applied to the nozzle 16.

In the apparatus 1 of the present embodiment, when the liquid composition is discharged from the nozzle 16, an air flow is generated in the air flow generating unit 21, and the liquid composition is transported by the air flow. Thus, when a coating is formed, the coating is not easily affected by the ambient environment in which the apparatus 1 is used, and a uniform coating can be formed regardless of the ambient environment. In particular, a uniform coating film can be formed regardless of changes in humidity.

In the electrostatic spray method, as a prior art for conveying a discharge with an air flow, the technique described in the above-described patent document 1 is known. However, in the technique described in this document, since the cavity and the electrode are provided at a position forward of the tip of the nozzle, the discharge discharged from the nozzle easily adheres to the inner wall defining the cavity and the electrode, and it is not easy to smoothly form a coating film of a target quality due to this. In contrast, according to the device 1 of the present embodiment, the electrode 20 and the cavity portion 22 are located behind the tip 16a of the nozzle 16, and therefore, in other words, when the electrostatic discharge portion P1 is viewed along the discharge direction X of the liquid composition, the tip 16a of the nozzle 16 is located at the most end portion (the most tip) of the electrostatic discharge portion P1, and therefore, there is no member that would interfere with the flight of the liquid composition discharged from the tip 16 a. As a result, according to the apparatus 1 of the present embodiment, even when the liquid composition is transported and flown by the air flow, the target coating can be smoothly formed.

From the viewpoint of making the advantages of the apparatus 1 of the present embodiment more remarkable, it is desirable that the temporary accumulation action of the air flow generated by the air flow generating section 21 in the cavity section 22 is sufficient. From this viewpoint, the volume V (cm) of the cavity 22 is³) Flow rate F (cm) with respect to the air flow generated by the air flow generating part 21³The value of V/F (min), which is the ratio of/min), is preferably 0.001min or more, more preferably 0.002min or more, and still more preferably 0.005min or more. The value of V/F (min) is preferably 0.5min or less, more preferably 0.2min or less, and still more preferably 0.1min or less. In particular, the value of V/f (min) is preferably 0.001min to 0.5min, more preferably 0.002min to 0.2min, and still more preferably 0.005min to 0.1 min.

The preferable range of the value of V/F (min) is as described above, but the value of the volume V itself of the cavity portion 22 is preferably 10cm³Above and 1000cm³Hereinafter, more preferably 20cm³Above and 500cm³Hereinafter, more preferably 30cm³Above and 100cm³The following. On the other hand, the flow rate F itself of the air flow preferably has a value of 100cm³More than min and 50000cm³Less than min, more preferably 250cm³More than min and 30000cm³Min or less, more preferably 500cm³More than min and 20000cm³Less than min. The volume V of the cavity 22 is equal to the volume of the internal space of the tubular body 25 defining the cavity 22 when no other member is present in the cavity 22, and is obtained by subtracting the volume of the member from the volume of the internal space of the tubular body 25 when no other member is present in the cavity 22.

In the apparatus 1 of the present embodiment, the nozzle 16 has a liquid composition flow path for allowing the liquid composition to reach the tip 16a of the nozzle 16 via the electrode 20. The casing 10 forming a part of the apparatus 1 has a pipe line 17 including the liquid composition flow path. The conduit 17 is disposed in the cavity 22 as shown in fig. 1. However, in order to fully utilize the temporary accumulation action of the air flow by the cavity 22, it is desirable that no other member is present as much as possible in the internal space of the cylindrical body 25 defining the cavity 22. From this viewpoint, it is advantageous that the outer periphery of the pipeline 17 is surrounded by the space of the cavity portion 22, and the cavity portion 22 is located rearward of the pipeline 17. By disposing the duct 17 in the cavity 22 in this manner, the flow of the air in the cavity 22 is smooth, and the air flow is uniformly discharged from the air discharge ports 24.

From another viewpoint for fully utilizing the temporary accumulation action of the air flow in the cavity 22, it is preferable that the difference in the cross-sectional area of the outer edge of the cavity 22, in other words, the cross-sectional area of the inner wall of the tubular body 25 in the direction perpendicular to the direction of the air flow generated by the air flow generating section 21 (the direction being the same as the discharge direction X of the liquid composition) is small when compared at arbitrary different positions along the discharge direction X. The ratio of the average value (Q2) of the cross-sectional area at the position other than the position adjacent to the air flow generating portion 21 to the cross-sectional area (Q1) of the outer edge of the cavity 22 at the position adjacent to the air flow generating portion 21, that is, the value of Q2/Q1 is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more. The ratio is preferably 120% or less, more preferably 110% or less, and still more preferably 105% or less. The outer edge of the cavity 22 is an outer edge of a space forming the cavity 22, and the cross-sectional area of the outer edge is calculated from the cross-sectional area of the outer edge of the cavity excluding a pipe, a power cord, or other connection part when the connection part is provided in part. The airflow generating portion 21 is, for example, a region where a fan is provided, and the position of the cavity portion 22 at a position adjacent to the airflow generating portion 21 is a fan-side end portion of the cylindrical portion adjacent to the region where the fan is provided.

From the viewpoint of temporarily accumulating the air flow generated by the air flow generating portion 21 in the cavity 22, the average value (Q3) of the cross-sectional area of the air flow generating portion 21 in the direction orthogonal to the direction of the air flow generated by the air flow generating portion 21 (the direction is the same direction as the discharge direction X of the liquid composition) contains a fan or the like therein, and therefore is preferably slightly larger than or the same as the area (Q1) of the cross-sectional area of the outer edge of the cavity 22 at a position adjacent to the air flow generating portion 21, and for example, the value of the ratio Q3/Q1 of the cross-sectional area is preferably 80% or more, more preferably 90% or more, preferably 170% or less, and more preferably 150% or less.

In association with the above-mentioned ratio, the above-mentioned Q1, Q2 and Q3 are each individually preferably 5cm²Above and 30cm²Hereinafter, more preferably 7cm²Above and 25cm²Hereinafter, more preferably 7cm²Above and 20cm²The following.

As described above, the cavity portion 22 defined by the cylindrical body 25 is preferably adjacent to the air ejection port 24. Therefore, the air flow passing through the cavity 22 is smoothly ejected from the air ejection port 24. From the viewpoint of making this advantage more remarkable, the length of the air ejection port 24 along the direction of the air flow is preferably 10mm or less, more preferably 8mm or less, and further preferably 6mm or less. The lower limit of the length is not particularly limited, and is, for example, preferably 0.1mm or more, and more preferably 0.5mm or more. Further, if the length is as short as about 2mm, the air flow can be ejected from the air ejection port 24 very smoothly.

From the viewpoint of ejecting the air flow from the air ejection ports 24 at a high speed by utilizing the principle of the orifice, the ratio of the total area of the air ejection ports 24 to the area (Q1) of the cross section of the outer edge of the cavity portion 22 at the position adjacent to the air flow generating portion 21 (hereinafter, this ratio is referred to as "ejection port area ratio") is preferably 1.5% or more, more preferably 3% or more, and still more preferably 5% or more. The ejection opening area ratio is preferably 70% or less, more preferably 50% or less, and still more preferably 30% or less. Specifically, the ejection opening area ratio is preferably 1.5% or more and 70% or less, more preferably 3% or more and 50% or less, and still more preferably 5% or more and 30% or less.

The device 1 is configured such that the discharge amount of the air flow from the air discharge port 24 is preferably adjusted to 100cm³More preferably, it is adjusted to 250 cm/min or more³A concentration of 500cm or more is more preferably adjusted³More than min. The apparatus 1 is preferably configured such that the amount of air flow discharged is adjusted to 50000cm³Less than min, more preferably 30000cm³Less than min, more preferably 20000cm³Less than min. In particular, the device 1 is configured such that the discharge amount of the air flow from the air discharge port 24 is preferably adjusted to 100cm³More than min and 50000cm³Less than min, more preferably 250cm³More than min and 30000cm³Less than min, more preferably 500cm³More than min and 20000cm³Less than min. This value is the amount of air flow ejected from the air ejection port 24 when only 1 air ejection port 24 is provided, and is the total amount of air flow ejected from all the air ejection ports 24 when a plurality of air ejection ports 24 are provided.

When the discharge amount of the air flow discharged from the air discharge port 24 is in the above range, the discharge amount of the liquid composition discharged from the nozzle 16 is preferably adjusted to 0.01g/min or more, more preferably 0.05g/min or more, and still more preferably 0.1g/min or more in view of smooth formation of the target coating film. The apparatus 1 is configured such that the discharge amount of the liquid composition is preferably adjusted to 2g/min or less, more preferably 1.5g/min or less, still more preferably 1.0g/min or less, and still more preferably 0.8g/min or less. In particular, the apparatus 1 is configured such that the discharge amount of the liquid composition is preferably adjusted to 0.01g/min to 2g/min, more preferably 0.05g/min to 1.5g/min, still more preferably 0.1g/min to 1.0g/min, and still more preferably 0.1g/min to 0.8 g/min.

From the viewpoint of smoothly forming the intended coating, the apparatus 1 is configured such that, when the liquid composition is discharged from the nozzle 16, the voltage applied to the liquid composition is adjusted to preferably 1kV or more, more preferably 5kV or more, and still more preferably 10kV or more. The voltage of the apparatus 1 is preferably adjusted to 40kV or less, more preferably 30kV or less, still more preferably 25kV or less, and still more preferably 20kV or less. In particular, the apparatus 1 is configured to adjust the voltage applied to the liquid composition to preferably 1kV or more and 40kV or less, more preferably 5kV or more and 30kV or less, still more preferably 10kV or more and 25kV or less, and still more preferably 10kV or more and 20kV or less.

Fig. 2 shows another embodiment of the film manufacturing apparatus of the present invention. The description of the embodiment shown in fig. 1 described above can be applied to the point that the present embodiment is not described in particular. In fig. 2, the same components as those in fig. 1 are denoted by the same reference numerals. The apparatus 1 of the embodiment shown in fig. 2 is roughly divided into an electrostatic spray part P1 and a stationary type housing part P2. The two are separated. In the embodiment shown in fig. 1 described above, the electrostatic discharge portion P1 is the device 1 itself, but in the present embodiment, among the components constituting the electrostatic discharge portion P1 of the embodiment shown in fig. 1, the low-voltage power supply 11 that applies a voltage to the electrode 20, the storage portion 15 that can store the liquid composition, and the pump 14 that is a liquid delivery portion that supplies the liquid composition to the nozzle 16 are stored in the fixed storage portion P2. The electrostatic discharge unit P1 and the stationary storage unit P2 are connected by a conduit 18 for transporting the liquid composition and an electric wire 27 for electrically connecting the electrode 20 and the low-voltage power supply 11. The electrostatic spray portion P1 has a size and/or shape that a person can hold with one hand. According to the present embodiment, the liquid composition can be discharged for a long time without impairing the ease of handling of the electrostatic discharge portion P1, and a large-area coating film can be easily formed.

In the embodiment shown in fig. 2, the pipe passage 18 and the electric wire 27 connecting the electrostatic spray part P1 and the fixed type housing part P2 are independent from each other, but the pipe passage 18 and the electric wire 27 may be bundled into 1 cable in consideration of the handleability of the electrostatic spray part P1.

By using the manufacturing apparatus for a coating film according to each of the embodiments described above, according to the present invention, it is possible to electrostatically eject a liquid composition containing a fiber-forming polymer directly onto the surface of an object while ejecting an air flow from an air ejection port, and to form a coating film composed of a deposit containing fibers on the surface.

The liquid composition used in each of the above embodiments includes a polymer having fiber formability. In addition, the liquid composition preferably contains 1 or 2 or more volatile substances selected from water, alcohol and ketone.

The volatile substance is a substance having volatility in a liquid state. In the liquid composition, the volatile material is formulated for the following purposes: after the liquid composition placed in the electric field is sufficiently charged, the liquid composition is discharged from the tip 16a of the nozzle 16 toward the skin, and when the volatile substance gradually evaporates, the charge density of the liquid composition becomes excessive, and the volatile substance further evaporates while the polymer is refined by coulomb repulsion, and finally the fiber is formed. To achieve this object, the vapor pressure of the volatile substance is preferably 0.01kPa or more and 106.66kPa or less, more preferably 0.13kPa or more and 66.66kPa or less, still more preferably 0.67kPa or more and 40.00kPa or less, and still more preferably 1.33kPa or more and 40.00kPa or less at 20 ℃.

Among the volatile substances, the alcohol is preferably a monohydric chain aliphatic alcohol having 1 to 6 carbon atoms, a monohydric cyclic aliphatic alcohol having 3 to 6 carbon atoms, or a monohydric aromatic alcohol. Specific examples thereof include ethanol, isopropanol, butanol, phenethyl alcohol, propanol, pentanol and the like. These alcohols can be used in 1 or 2 or more kinds selected from them.

Among the volatile substances, preferred ketones include, for example, chain aliphatic ketones having 3 to 6 carbon atoms, cyclic aliphatic ketones having 3 to 6 carbon atoms, and aromatic ketones having 8 to 10 carbon atoms. Specific examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone and the like. These ketones can be used alone in 1 kind, or in combination with 2 or more kinds.

Among the volatile substances, ion-exchanged water, purified water, or distilled water is preferably used as the water. By adding water to the liquid composition, the conductivity of the liquid composition can be improved by ionization of water. By making the liquid composition have high conductivity, a fibrous coating can be stably formed on the surface of an application site such as skin when electrostatic spraying is performed. In addition, water contributes to improving the adhesion of the film formed by electrostatic spraying to the skin and the like.

The volatile substance is more preferably 1 or 2 or more selected from ethanol, isopropanol, butanol and water, more preferably 1 or 2 or more selected from water, ethanol and butanol, and further preferably water and ethanol.

The volatile substance (a) is preferably 1 or 2 or more selected from ethanol, isopropanol and butanol, and (b) is preferably a mixed solution with water, from the viewpoint of dispersibility of the fiber-forming polymer used together with the volatile substance and from the viewpoint of imparting an electric charge. The value of (b)/(a) which is the mass ratio of (a) to (b) is preferably 0.0025 to 1, more preferably 0.0025 to 0.85, from the viewpoint of fiber formability and coating film adhesion. When the fiber-forming polymer contains 50 mass% or more of the water-insoluble polymer, the value of (b)/(a) which is the mass ratio of the component (a) to the component (b) is preferably 0.0025 to 0.3, more preferably 0.0025 to 0.2, from the viewpoint of fiber-forming properties and film adhesion.

The content of water in the liquid composition is preferably 0.2 mass% or more and 45 mass% or less, and more preferably 0.3 mass% or more and 40 mass% or less, from the viewpoint of further improving the fiber formability and the close adhesion of the coating film. When the fiber-forming polymer contains a water-insoluble polymer, the content of water in the liquid composition is preferably 0.2% by mass or more and 25% by mass or less, more preferably 0.3% by mass or more and 20% by mass or less, still more preferably 0.35% by mass or more and 19% by mass or less, and still more preferably 0.4% by mass or more and 18% by mass or less.

The fiber forming polymer used with the volatile material is typically a substance that is soluble in the volatile material. Here, the dissolution means a state of dispersion at 20 ℃, and the dispersed state is uniform in visual observation, and is preferably a transparent or translucent state in visual observation.

As the fiber-forming polymer, an appropriate polymer is used depending on the properties of the volatile material. Specifically, the fiber-forming polymer is roughly classified into a water-soluble polymer and a water-insoluble polymer. In the present specification, "water-soluble polymer" means a substance having the following properties: after 1g of the polymer was weighed under an atmosphere of 1 atm at 23 ℃, 10g of ion-exchanged water was immersed in the weighed polymer, and after 24 hours, 0.5g or more of the immersed polymer was dissolved in water. On the other hand, the "water-insoluble polymer" in the present specification means a substance having the following properties: after 1g of the polymer was weighed under an atmosphere of 1 atmosphere at 23 ℃, 10g of ion-exchanged water was immersed in the weighed polymer, and after 24 hours, more than 0.5g of the immersed polymer was not dissolved.

Examples of the water-soluble fiber-forming polymer include pullulan, hyaluronic acid, chondroitin sulfate, poly-gamma-glutamic acid, modified corn starch, beta-glucan, polyglucose, heparin, mucopolysaccharide such as keratan sulfate, cellulose, pectin, xylan, chitosan, lignin, glucomannan, galacturonic acid, psyllium seed gum, tamarind seed gum, gum arabic, tragacanth gum, soybean water-soluble polysaccharide, alginic acid, carrageenan, laminarin, agar (agarose), fucoidan, methyl cellulose, hydroxypropyl cellulose, a natural polymer such as hydroxypropyl methyl cellulose, partially saponified polyvinyl alcohol (when used without a crosslinking agent), low-saponified polyvinyl alcohol, polyvinyl pyrrolidone (PVP), polyethylene oxide, sodium polyacrylate, water-soluble polyamide resin such as water-soluble nylon, partially saponified polyvinyl alcohol, and the like, Synthetic polymers such as water-soluble urethane resins. These water-soluble polymers can be used alone or in combination of 1 or 2 or more. Among these water-soluble polymers, synthetic polymers such as pullulan, partially saponified polyvinyl alcohol, low saponified polyvinyl alcohol, polyvinyl pyrrolidone, chitosan, water-soluble polyamide resins, water-soluble polyurethane resins, and polyethylene oxide are preferably used from the viewpoint of ease of production of a coating film. When polyethylene oxide is used as the water-soluble polymer, the number average molecular weight thereof is preferably 5 to 300 ten thousand, more preferably 10 to 250 ten thousand.

On the other hand, examples of the water-insoluble fiber-forming polymer include completely saponified polyvinyl alcohol capable of being insolubilized after fiber formation, partially saponified polyvinyl alcohol capable of being crosslinked after fiber formation by using a crosslinking agent in combination, oxazoline-modified silicones such as poly (N-propionylethyleneimine) graft-dimethylsiloxane/γ -aminopropylmethylsiloxane copolymers, polyvinylacetal-diethylaminoacetate, zein (a main component of zein), acrylic resins such as polyesters, polylactic acid (PLA), polyacrylonitrile resins, polymethacrylic resins, polystyrene resins, polyvinylbutyral resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polyurethane resins, polyamide resins, and the like, Polyimide resins, polyamideimide resins, and the like. In the present invention, 1 or 2 or more kinds selected from these water-insoluble polymers can be used in combination. Among these water-insoluble polymers, oxazoline-modified silicones such as fully saponified polyvinyl alcohol which can be insolubilized after fiber formation, partially saponified polyvinyl alcohol which can be crosslinked after fiber formation by using a crosslinking agent in combination, polyvinyl butyral resin, polymethacrylic resin, polyvinyl acetal diethylaminoacetate, poly (N-propionylethyleneimine) graft-dimethylsiloxane/γ -aminopropylmethylsiloxane copolymer, polyurethane resins, polyamide resins, polylactic acid, zein, and the like are preferably used.

The content of the volatile substance in the liquid composition is preferably 50 mass% or more and 95 mass% or less, more preferably 55 mass% or more and 94 mass% or less, still more preferably 60 mass% or more and 93 mass% or less, and still more preferably 65 mass% or more and 92 mass% or less. By adjusting the volatility to the liquid composition at the above ratio, the liquid composition can be sufficiently volatilized when the electrostatic discharge method treatment is performed.

On the other hand, the content of the fiber-forming polymer in the liquid composition is preferably 2% by mass or more and 35% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and further preferably 5% by mass or more and 25% by mass or less. By blending the fiber-forming polymer in the liquid composition at the above ratio, a desired coating film can be formed smoothly.

When a fiber deposit is formed by the apparatus 1 of the present embodiment, the thickness of the fibers is preferably 10nm or more, and more preferably 50nm or more, when expressed as a circle-equivalent diameter. Further, it is preferably 3000nm or less, and more preferably 1000nm or less. The thickness (fineness) of the fiber is measured by, for example, observing the fiber at 10000 times by Scanning Electron Microscope (SEM) observation, excluding defects (clumps of the fiber, intersections of the fiber, and droplets) from the two-dimensional image, selecting 10 arbitrary fibers, drawing a line perpendicular to the longitudinal direction of the fiber, and directly reading the fiber diameter.

The fibers are continuous fibers of infinite length in terms of the principle of production, but preferably have a length of 100 times or more the thickness of the fibers. In the present specification, a fiber having a length 100 times or more the thickness of the fiber is defined as a "continuous fiber". The coating produced by the apparatus 1 of the present embodiment is preferably a porous discontinuous coating composed of a deposit of continuous fibers. The coating film of this embodiment is handled as an aggregate in 1 piece, has very soft characteristics, and is not easily torn even if a shear force is applied thereto.

When a coating is formed using the apparatus 1 of the present embodiment, the distance between the nozzle 16 and the application site also depends on the voltage applied to the nozzle 16, but is preferably 10mm or more, more preferably 20mm or more, further preferably 40mm or more, and further preferably 60mm or more, from the viewpoint of smooth formation of the coating. The distance between the nozzle 16 and the application site is preferably 300mm or less, more preferably 250mm or less, further preferably 200mm or less, and further preferably 150mm or less. More specifically, the distance between the nozzle 16 and the application site is preferably 10mm or more and 300mm or less, more preferably 20mm or more and 250mm or less, further preferably 40mm or more and 200mm or less, and further preferably 60mm or more and 150mm or less. The distance between the nozzle and the application site can be measured by a generally used non-contact sensor or the like.

The grammage of the coating film is 1m per coating film regardless of whether the coating film formed by the apparatus 1 of the present embodiment is porous or not²In terms of skin, it is preferably 0.05g/m²Above, more preferably 0.1g/m²Above, more preferably 1g/m²The above. Further, it is preferably 50g/m²Hereinafter, more preferably 40g/m²Hereinafter, more preferably 30g/m²Hereinafter, it is more preferably 25g/m²The amount of the surfactant is more preferably 20g/m or less²The following. For example, the grammage of the coating film is 1m²In terms of skin, it is preferably 0.05g/m²Above and 50g/m²Hereinafter, more preferably 0.1g/m²Above and 40g/m²Hereinafter, more preferably 0.1g/m²Above and 30g/m²Hereinafter, more preferably 0.1g/m²Above and 25g/m²Hereinafter, more preferably 1g/m²Above and 20g/m²The following. By setting the grammage of the coating film in this manner, peeling of the coating film due to excessive thickening of the coating film can be effectively prevented.

The present invention has been described above based on preferred embodiments, but the present invention is not limited to the above embodiments. For example, in the above embodiments. The electrostatic discharge unit P1 is a hand-held type, but the electrostatic discharge unit P1 may be a large stationary type electrostatic discharge unit instead of the hand-held type electrostatic discharge unit.

Examples

The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to this embodiment. Unless otherwise specified, "%" means "% by mass".

[ example 1]

(1) Preparing a liquid composition

A liquid composition containing 88% of 99.5% ethanol (water 0.5%) and 12% of polyvinyl butyral was prepared. As the polyvinyl butyral, S-LEC B BM-1 (trade name) manufactured by Water chemical Co., Ltd was used.

(2) Manufacturing device for preparing coating film

An apparatus having the structure shown in fig. 1 was prepared. The volume of the cavity 22 is 72cm³(value obtained by subtracting the volume of the pipe 17), the flow rate of the air flow generated by the air flow generating unit 21 was 750cm³And/min. The cylindrical body 25 constituting the cavity 22 was cylindrical, and had a diameter of 32mm and a cross-sectional area Q1 of 8.04cm². The cross-sectional area Q2 was 7.1cm²(average diameter 30mm) and Q3 of 11.3cm².8 circular air ejection ports 24 were provided, and the length of 23a in the direction of air flow was set to 6 mm. The above-mentioned ejection orifice area ratio was 6.2%.

(3) Forming a coating film consisting of a pile of fibers

The discharge amount of the liquid composition from the nozzle 16 was set to 0.12g/min, and the discharge amount of the air from the air outlet 24 was set to 750cm³The voltage applied to the electrode 20 was set to 10kV at/min. Under these conditions, a coating film consisting of a deposit of fibers was formed on one surface of a collector plate made of polyoxymethylene by an electrospinning method, and the distance between the tip 16a of the nozzle 16 and the collector plate was set to 100 mm. The ambient environment for the electrospinning was 30 ℃ and 70% RH.

[ examples 2 to 4 and comparative examples 1 and 2 ]

The ejection rate of air from the air ejection port 24 and the ambient environment were set to values shown in table 1 below. In addition to these, a coating film composed of a fiber deposit was formed in the same manner as in example 1.

[ evaluation ]

The state of the coating films obtained in examples and comparative examples was visually observed and evaluated according to the following criteria. The results are shown in table 1.

< evaluation Standard of film formation >

A: has high adhesion to the skin and forms a good film.

B: the formation of the coating film was unstable, and there was unevenness in the adhesion of the coating film to the skin.

C: the fibers returned to the production apparatus are generated and accumulated on the skin in an undried state, and droplets are generated.

[ Table 1]

From the results shown in table 1, it is understood that the coating obtained in each example has good adhesion to the collection plate and little unevenness. In contrast, the coating obtained in the comparative example is affected by the surrounding environment, and the adhesion is poor and uneven in many cases.

Industrial applicability of the invention

As described above in detail, according to the present invention, a coating film made of a pile of fibers can be easily formed. According to the present invention, for example, even in an environment where it is difficult to control the environment to a constant temperature and a constant humidity, a uniform coating film can be easily formed.