JP2013063411A - Coating material storage system and storage method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material storage system and a storage method that prevent the generation of foreign matters by preventing the formation of a dry membrane on the internal surface of a coating material storage tank and store a coating material containing a volatile organic solvent stably over a long period of time by controlling a change in the concentration of the coating material.SOLUTION: The coating material storage system includes the coating material storage tank having an airtight structure to store the coating material containing a volatile organic solvent, an organic solvent storage tank having an airtight structure to store the organic solvent containing a component equal or equivalent to the organic solvent, and gas supply piping to supply gas bubbled in the organic solvent in the organic solvent storage tank to the top of the coating material storage tank.

Description

  The present invention relates to a paint storage system and a storage method for stably storing a paint containing a volatile organic solvent for a long period of time.

  Solvent-type paints, adhesives, adhesives, etc. (hereinafter collectively referred to as paints) composed of a resin composition dissolved in a volatile organic solvent will evaporate and dry if left in the atmosphere. To form a cured coating. The paint that has been dried has a high viscosity due to the formation of a film on the surface (liquid surface) of the paint or the evaporation of the organic solvent inside the paint, resulting in a high viscosity of the resin composition. Or the nozzle for applying paint may be clogged. For this reason, for example, as disclosed in Patent Document 1-2, various measures have been proposed, such as supplying an anti-drying liquid to the nozzle surface or spraying a solvent on the slot opening of the coating head.

JP 2010-69635 A JP-A-6-339657

  If an organic solvent for preventing drying is supplied to the nozzle surface in order to prevent the paint from drying, the concentration of the resin composition in the applied paint will fluctuate, resulting in a coating film having a certain stable film thickness. There was a problem that it could not be obtained.

  Even when a paint containing a volatile organic solvent is stored in a sealed container, the organic solvent is removed from the liquid surface of the paint until the vapor phase reaches the saturated vapor pressure of the organic solvent. Evaporation occurs, and along with this, drying of the liquid surface portion of the paint and formation of a cured film proceed.

  In the paint storage tank in which the paint containing the volatile organic solvent is stored, when the paint is supplied from the paint storage tank to the paint application device or the like and consumed, the liquid level of the paint decreases. As a result, the paint film adhering to the inner wall surface of the paint storage tank is dried to form a cured film. The cured paint film formed on the inner wall surface of the paint storage tank peels off and mixes in the paint, causing clogging of the paint supply piping, and foreign matter on the paint application surface. There is a problem that the product adheres and soils the product.

  Therefore, the present invention prevents the formation of a dry film on the inner wall surface of the paint storage tank to prevent the generation of foreign substances, and suppresses the fluctuation in the concentration of the paint so that a paint containing a volatile organic solvent can be used for a long time. It is an object of the present invention to provide a paint storage system and a storage method that stably store over a long period of time.

  In order to solve the above problems, the present invention provides a coating material by supplying a gas such as air or an inert gas bubbled in an organic solvent to the top of a coating material storage tank that stores a coating material containing a volatile organic solvent. The technical idea is to prevent the coating material adhering to the inner wall surface of the coating material storage tank from drying and forming a cured film even when the liquid level is lowered.

Specifically, the present invention is a paint storage system for storing paint containing a volatile organic solvent, and a paint storage tank having an airtight structure for storing the paint, and the same or equivalent to the organic solvent An organic solvent storage tank having an airtight structure storing an organic solvent containing components, and a gas supply pipe for supplying a gas bubbled in the organic solvent in the organic solvent storage tank to the top of the paint storage tank, It is characterized by providing.

  Here, the paint is composed of a resin composition dissolved in a volatile organic solvent, and examples thereof include solvent-type paints, pressure-sensitive adhesives, and adhesives. The same component as the organic solvent is the same volatile component as the organic solvent contained in the paint stored in the paint storage tank, and the same component as the organic solvent is stored in the paint storage tank at the same temperature. A volatile component having a saturated vapor pressure equivalent to or higher than that of the organic solvent contained in the paint to be applied and having no adverse effect on the resin composition contained in the paint.

  The paint from which gas such as dissolved air has been degassed by evacuation is held at a pressure close to atmospheric pressure in a paint storage tank having an airtight structure so that impurities such as moisture and dust do not enter. Are stored. If the vapor pressure of the organic solvent contained in the paint stored in the paint storage tank reaches the saturated vapor pressure, the organic solvent does not evaporate, so that the drying of the paint does not proceed. Therefore, it is conceivable to control the vapor pressure of the organic solvent contained in the paint in the paint storage tank to prevent the paint from progressing and prevent the formation of a cured film. Therefore, it is difficult to always keep the inside of the paint storage tank at a saturated vapor pressure by measuring them.

  By the way, the organic solvent evaporates from the paint stored in the paint storage tank until the gas phase reaches the saturated vapor pressure. Therefore, a gas such as air or an inert gas that has not reached the saturated vapor pressure is positively brought into contact with an organic solvent containing the same or equivalent component as the organic solvent contained in the paint. If it is made to contain to a saturated vapor pressure and if it supplies to a coating material storage tank, the gaseous-phase part of a coating material storage tank will be filled with saturated steam.

  Therefore, the paint storage system according to the present invention has an airtight structure containing an organic solvent containing the same or equivalent component as the organic solvent contained in the paint, in addition to the paint storage tank for storing the paint. Air or inert gas is bubbled through the organic solvent in the solvent storage tank. As a result, a gas that has reached the saturated vapor pressure of the organic solvent contained in the paint stored in the paint storage tank is quickly generated, and this gas is supplied to the top of the paint storage tank. If the gas that has reached the saturated vapor pressure of the organic solvent contained in the paint stored in the paint storage tank is supplied to the paint storage tank, the paint remains in the paint storage tank or adheres to the inner wall of the paint storage tank. Drying is suppressed. Therefore, it is possible to stably store a paint containing a volatile organic solvent for a long period of time.

  In addition, the said paint storage tank is provided with two or more, is comprised from 2 series of A series and B series, and the said A series and the said B series consist of one or several paint storage tanks, respectively, The paint stored in any one of the one or a plurality of A-series paint storage tanks is used as the paint storage tank of any one of the other one or a plurality of B-series paint storage tanks. After bubbling the gas in the vapor phase of any one of the one or more B-series paint storage tanks to the organic solvent in the organic solvent storage tank A gas supply pipe for transferring to the top of any one of the other one or a plurality of A-series paint storage tanks may be provided.

A plurality of paint storage tanks are provided, and these are composed of two systems of A series and B series, and each series consists of one or more paint storage tanks. A gas supply pipe for transferring the gas in the gas phase of any one of the paint storage tanks of the series to one of the other one or a plurality of A series paint storage tanks; If provided, the paint stored in any one of the one or a plurality of A-series paint storage tanks is replaced with one of the other one or a plurality of B-series paint storage tanks. When transferring to the paint storage tank using the paint supply pipe, the gas in the gas phase portion of the paint storage tank whose liquid level rises flows to the paint storage tank whose liquid level falls. Therefore, by performing bubbling using such a gas flow, the gas phase portion of the paint storage tank can be quickly brought to the saturated vapor pressure while generating a gas saturated with the component of the organic solvent.

  The paint storage system heats the organic solvent in the organic solvent storage tank so that the temperature of the organic solvent in the organic solvent storage tank is at least higher than the temperature of the paint in the paint storage tank. It may be characterized by further having a heating means.

  The saturated vapor pressure of an organic solvent generally increases with temperature. Therefore, if the temperature of the organic solvent in the organic solvent storage tank is at least higher than the temperature of the paint in the paint storage tank, the organic solvent storage tank containing the same or equivalent component as the organic solvent contained in the paint The saturated vapor pressure of the organic solvent becomes higher than the saturated vapor pressure of the organic solvent contained in the paint. By bubbling with the organic solvent in the organic solvent storage tank heated in this way, a gas with a concentration higher than the saturated vapor pressure of the organic solvent contained in the paint in the paint storage tank is generated in the organic solvent storage tank. Then, the gas is supplied to the top of the paint storage tank through the gas supply pipe. As a result, the gas phase part of the paint storage tank is filled with a replenishing gas having a vapor pressure equal to or higher than the saturated vapor pressure of the organic solvent contained in the paint, and the paint adhering to the inner wall surface of the paint storage tank Is more reliably suppressed. Therefore, by preventing the formation of a dry film on the inner wall surface of the paint storage tank and preventing the generation of foreign matter, the paint concentration containing volatile organic solvents can be stabilized over a long period of time by suppressing the fluctuation of the paint concentration. Can be stored.

  The present invention can also be understood from the aspect of the method invention. For example, the present invention is a paint storage method for storing a paint containing a volatile organic solvent, wherein the organic solvent storage tank has an airtight structure storing an organic solvent containing the same or equivalent component as the organic solvent. The gas bubbled in (1) may be supplied to the top of a paint storage tank having an airtight structure for storing the paint.

  According to the present invention, the formation of a dry film on the inner wall surface of the paint storage tank is prevented to prevent the generation of foreign matter, and the paint concentration containing a volatile organic solvent can be reduced for a long period of time by suppressing the concentration fluctuation of the paint. Can be stably stored.

It is a schematic block diagram of 1st embodiment in the coating material storage system of this invention. It is the figure which showed the usage method of 1st embodiment in the coating material storage system of this invention. It is a modification of the coating material storage tank in 1st embodiment of the coating material storage system concerning this invention. It is a schematic block diagram of 2nd embodiment in the coating material storage system of this invention. It is the figure which showed the usage method of 2nd embodiment in the coating material storage system of this invention.

  Hereinafter, embodiments of the present invention will be described. The following embodiment is an exemplification of the embodiment of the present invention, and does not limit the technical scope of the present invention.

<First embodiment>
FIG. 1 is a schematic configuration diagram of the first embodiment in the paint storage system 10 of the present invention. The paint storage system 10 includes two paint storage tanks 11A and 11B and a gas supply piping system 12 as shown in FIG.

  In the two paint storage tanks, for example, one paint storage tank 11 </ b> A is used as a preparation tank for the paint 30, and the other paint storage tank 11 </ b> B is an adjustment tank for paying out to the coating device for the paint 30. It will be described below assuming it is used.

  The paint 30 is made of a resin composition dissolved in a volatile organic solvent, and examples thereof include a solvent-type paint, a pressure-sensitive adhesive, and an adhesive. The paint storage tanks 11A and 11B are hermetic containers having an airtight structure in which the gas phase part is not opened to the atmosphere, and when the liquid level of the paint 30 fluctuates, pressure fluctuations in the gas phase part are generated so as not to become negative pressure. In addition, gas such as air or inert gas is replenished from the gas supply piping system 12.

  In the organic solvent storage tank 13 for storing the organic solvent 31 containing the same or equivalent component as the organic solvent contained in the paint 30 stored in the paint storage tank 11A, 11B, dehumidified and purified air, inert gas, etc. Is supplied from an external gas supply device (not shown) through the gas supply pipe 14.

  The component of the organic solvent 31 is introduced into the gas phase part of the organic solvent storage tank 13 by bubbling the gas supplied through the gas supply pipe 14 into the liquid phase part of the organic solvent storage tank 13 storing the organic solvent 31. Saturated gas is generated.

  The organic solvent 31 stored in the organic solvent storage tank 13 is preferably the same component as the organic solvent contained in the paint 30 stored in the paint storage tanks 11A and 11B. When organic solvent is composed of multiple components and it takes time to prepare, it must contain the same components as organic solvent contained in paint 30 stored in paint storage tanks 11A and 11B. Is possible.

  In addition, the organic solvent 31 stored in the organic solvent storage tank 13 is the same as the organic solvent contained in the paint 30 stored in the paint storage tank and the same component as the organic solvent contained in the paint 30 stored in the paint storage tank 11A, 11B. A chemical substance and a component equivalent to an organic solvent have a saturated vapor pressure equal to or higher than that of the organic solvent contained in the paint 30 stored in the paint storage tank at the same temperature. A chemical substance that does not adversely affect the resin composition contained in the paint 30.

Examples of common organic solvents used for dissolving the paint 30 include ethyl acetate, acetone, methyl ethyl ketone, and the like. From the physical properties of these chemical substances shown in Table 1, when ethyl acetate is used as the organic solvent contained in the paint 30, acetone and methyl ethyl ketone can be handled as equivalent organic solvents.

  The capacity of the organic solvent storage tank 13 and the amount of the organic solvent 31 stored in the organic solvent storage tank 13 are the sizes of the paint storage tanks 11A and 11B, the amount of the paint 30 stored in the paint storage tanks 11A and 11B, and the amount of the paint 30. It is determined appropriately according to the consumption per hour.

  A paint supply pipe 15 connected to the bottom of the paint storage tank 11B is provided at the bottom of the paint storage tank 11A. A transfer pump 16 for transferring the paint 30 is provided in the middle of the paint supply pipe 15. The transfer pump 16 is a pump capable of transferring the paint 30 to either the paint storage tank 11A side or the paint storage tank 11B side. The switching of the flow direction of the transfer pump 16 may be realized by opening and closing piping and valves (not shown), or may be realized by a motor and a pump capable of normal rotation and reverse rotation.

  When the transfer pump 16 is other than the plunger type, a valve for preventing the paint 30 from flowing out of the paint storage tank 11A is provided in the paint supply pipe 15 while the transfer pump 16 is stopped. It is good to open and close according to the driving state. In addition, the paint storage tanks 11A and 11B may be provided with a safety valve for preventing destruction of the tank, a vent valve, a drain valve, or the like used when maintaining the tank. The paint storage tank 11B is provided with a pipe 25 for dispensing the paint 30 to the coating device for the paint 30.

  The lid 17A of the paint storage tank 11A includes an exhaust pipe 18A for flowing the gas in the gas phase portion of the paint storage tank 11A to the organic solvent storage tank 13 when the internal pressure of the paint storage tank 11A rises above a predetermined value, and the paint When the internal pressure of the storage tank 11A falls below a predetermined value, a gas supply pipe 19A for flowing the gas bubbled from the organic solvent storage tank 13 to the paint storage tank 11A is connected. The opening end of the exhaust pipe 18A on the organic solvent storage tank 13 side is located below the liquid level of the stored organic solvent 31 and is located in the lower part of the organic solvent storage tank 13, and the organic solvent in the gas supply pipe 19A. The opening end on the storage tank 13 side is located above the organic solvent storage tank 13 so as to be above the liquid level of the stored organic solvent 31.

  The exhaust pipe 18A is provided with a check valve 20A that prevents fluid from flowing from the organic solvent storage tank 13 side to the paint storage tank 11A side. Further, the gas supply pipe 19A is provided with a check valve 21A for preventing a fluid from flowing from the paint storage tank 11A side to the organic solvent storage tank 13 side.

  In addition, the configuration of the exhaust pipe 18A, the gas supply pipe 19A, the check valves 20A, 21A, and the like has been described for the paint storage tank 11A, but the exhaust pipe 18B and the paint storage tank 11B are similar to the paint storage tank 11A side. The gas supply pipe 19B is connected to the lid 17B, the exhaust pipe 18B is provided with a check valve 20B, and the gas supply pipe 19B is provided with a check valve 21B.

The check valves 20A and 20B disposed in the exhaust pipes 18A and 18B and the check valves 21A and 21B disposed in the gas supply pipes 19A and 19B have equivalent functions. It can be replaced with an automatic valve. For example, paint storage tanks 11A and 11B
A pressure detector (not shown) with a setting device provided in the above is combined with an automatic valve operated by air. If the pressure in the paint storage tank 11A is equal to or higher than a predetermined pressure, an air-operated automatic valve (not shown) disposed in the exhaust pipe 18A is opened to supply the gas phase gas in the paint storage tank 11A. Transfer to the organic solvent storage tank 13. If the pressure in the paint storage tank 11A is equal to or lower than a predetermined pressure, an air-operated automatic valve (not shown) disposed in the gas supply pipe 19A is opened, and the organic solvent in the organic solvent storage tank 13 is organic. You may supply the vapor | steam of a solvent to the top part of 11 A of coating material storage tanks.

<How to use the first embodiment>
The paint storage system 10 according to the present invention configured as described above can be used, for example, as follows. An example of how to use the paint storage system 10 is shown in FIG. For example, various raw materials for preparing the coating material 30 are introduced into the coating material storage tank 11A whose internal pressure is not adjusted at all and adjusted to a predetermined composition (FIG. 2A). By operating the paint storage system 10 as follows, the vapor pressure of the organic solvent in the paint storage tank 11A and the paint storage tank 11B can be set to the saturated vapor pressure, and the paint 30 can be prevented from drying. Therefore, the formation of a dry film on the inner wall surface of the paint storage tank is prevented to prevent the generation of foreign matters, and the concentration variation of the paint 30 is suppressed, so that the paint 30 containing a volatile organic solvent can be applied over a long period of time. It is possible to store stably.

  First, the transfer pump 16 is operated to transfer the paint 30 in the paint storage tank 11A to the paint storage tank 11B (FIG. 2B). When the paint 30 is transferred from the paint storage tank 11A to the paint storage tank 11B, the internal pressure of the paint storage tank 11B rises above a predetermined value, and the gas in the gas phase portion of the paint storage tank 11B flows through the exhaust pipe 18B and becomes organic. It is introduced into the solvent storage tank 13. The gas in the gas phase part of the paint storage tank 11B introduced into the organic solvent storage tank 13 is foamed in the organic solvent 31 of the organic solvent storage tank 13 and goes up to the gas phase part, and passes through the gas supply pipe 19A. Then, the paint 30 flows to the paint storage tank 11A in which the internal pressure has decreased below a predetermined value due to the transfer of the paint 30. The gas in the gas phase portion of the paint storage tank 11B is saturated with the components of the organic solvent 31 when passing through the organic solvent 31 in the organic solvent storage tank 13. And since the gas saturated with the component of the organic solvent 31 flows into the paint storage tank 11A via the gas supply pipe 19A, the vapor pressure of the organic solvent in the paint storage tank 11A quickly reaches the saturated vapor pressure. .

  Next, using the transfer pump 16, a part of the paint 30 transferred to the paint storage tank 11B is returned again to the paint storage tank 11A (FIG. 2C). When the paint 30 is transferred from the paint storage tank 11B to the paint storage tank 11A, the gas in the gas phase portion of the paint storage tank 11A flows through the exhaust pipe 18A due to the same phenomenon as described above, and the organic solvent 31 of the organic solvent storage tank 13 It becomes foamy inside, goes up to the gas phase, and flows to the paint storage tank 11B via the gas supply pipe 19B. The gas in the gas phase portion of the paint storage tank 11 </ b> A is saturated with the components of the organic solvent 31 when passing through the organic solvent 31 in the organic solvent storage tank 13. As a result, the gas phase portion of the paint storage tank 11B in which almost no organic solvent component is mixed is also replaced with a gas saturated with the organic solvent component.

  As described above, when the paint storage system 10 is operated, the vapor pressure of the organic solvent in the gas phase part of the paint storage tanks 11A and 11B storing the paint 30 quickly reaches the saturated vapor pressure. Therefore, it is possible to prevent the generation of foreign matters by preventing the formation of a dry film of the paint 30 remaining attached to the inner wall surfaces of the paint storage tanks 11A and 11B.

That is, the gas bubbled with the organic solvent containing the same or equivalent component as the organic solvent contained in the paint 30 stored in the paint storage tank 11A, 11B is used as the paint storage tank 1.
1A and 11B are supplied to the gas phase portion. For this reason, the vapor pressure of the organic solvent in the paint storage tanks 11A and 11B is automatically and safely adjusted to the saturated vapor pressure of the solvent or a pressure close thereto. Therefore, the inside of the paint storage tanks 11 </ b> A and 11 </ b> B can be quickly adjusted to the saturated vapor pressure of the organic solvent contained in the paint 30, and drying of the paint 30 can be suppressed. Thereby, the coating material 30 containing a volatile organic solvent can be stably stored over a long period of time.

  Further, since the saturated vapor pressure of the paint 30 changes according to the temperature of the paint 30, the paint storage tank 11 </ b> A is used so that the temperature in the paint storage tanks 11 </ b> A and 11 </ b> B is not easily affected by external temperature changes. , 11B is preferably provided with a heat insulating material.

  In the paint storage system 10 according to the present invention, a gas concentration meter or a pressure gauge is installed in each paint storage tank 11A, 11B, and it is determined whether or not the inside of the paint storage tank 11A, 11B has reached a saturated vapor pressure. Confirmation may be possible. By monitoring the indicated value of the gas concentration meter, it is possible to monitor that the paint 30 stored in each paint storage tank 11A, 11B is out of the explosion limit range.

  Moreover, the coating material storage system 10 concerning this invention may provide the heating heater which heats the organic solvent 31 in the organic solvent storage tank 13 in the organic solvent storage tank 13 or piping connected to this. The heating heater may be, for example, a heat transfer tube that passes heated steam, or may be an electric heater. The warming heater warms the organic solvent 31 so that the temperature of the organic solvent 31 in the organic solvent storage tank 13 is at least higher than the temperature of the paint 30 in the paint storage tanks 11A and 11B. If the organic solvent 31 in the organic solvent storage tank 13 is heated in this way, the saturated vapor pressure of the organic solvent 31 in the organic solvent storage tank 13 is higher than the saturated vapor pressure of the paint 30 in the paint storage tanks 11A and 11B. Become. Therefore, the high concentration gas produced | generated by bubbling in the organic solvent storage tank 13 will be supplied to the coating material storage tanks 11A and 11B. Therefore, drying of the paint 30 can be suppressed more reliably.

  In addition, the output of a heating heater is not only the method of controlling so that it may become higher than the temperature of the coating material 30 in the coating material storage tank 11A, 11B, For example, the gas concentration meter installed in each coating material storage tank 11A, 11B or a pressure The meter may be monitored and controlled so that the vapor pressure of the organic solvent in the paint storage tanks 11A and 11B reaches the saturated vapor pressure.

  In addition, after operating the coating material storage system 10 according to the present invention in this way to set the vapor pressure of the organic solvent in the coating material storage tanks 11A and 11B to the saturated vapor pressure, the coating material 30 stored in the coating material storage tank 11B is applied to the coating device. When the gas is transferred, the gas supply valve of the gas replenishing pipe 14 to the organic solvent storage tank 13 is opened to start the transfer while supplying the gas.

  In addition, before the raw materials for preparing the various paints 30 are introduced into the paint storage tank 11A whose internal pressure is not adjusted at all and adjusted to a predetermined composition, gas is supplied to both the paint storage tanks 11A and 11B. The gas replenished from the pipe 14 is bubbled in the organic solvent 31 of the organic solvent storage tank 13, and then introduced into the paint storage tank 11A and the paint storage tank 11B via the gas supply pipe 19A and the gas supply pipe 19B. May be.

<Modification of First Embodiment>
In addition, although each paint storage tank 11A, 11B of the paint storage system 10 according to the present invention may be one each, the paint storage system 10 is not necessarily limited to such an embodiment. Instead, for example, as shown in FIG. 3, either or both of the paint storage tank 11 </ b> A and the paint storage tank 11 </ b> B may be provided with a plurality of units to form a tank group.

<Second embodiment>
FIG. 4 is a schematic configuration diagram of the paint storage system 50 for the paint 30 according to the second embodiment of the present invention. As shown in FIG. 4, the paint storage system 50 includes a paint storage tank 51, an organic solvent storage tank 53, and a gas supply piping system 52.

  The paint storage tank 51 will be described below on the assumption that the paint storage tank 51 is used as a preparation tank for the paint 30 and is used as it is as an adjustment tank for dispensing the paint 30 to the coating device.

  The paint storage tank 51 is a tank for storing the paint 30 as in the paint storage tanks 11A and 11B of the first embodiment, and is a sealable container that can make the gas phase portion airtight. Further, the paint storage tank 51 is provided with a pipe for discharging the paint 30 to the coating device for the paint 30.

  Similar to the gas supply piping system 12 of the first embodiment, the gas supply piping system 52 includes an organic solvent storage tank 53 that stores an organic solvent having the same or equivalent component as the organic solvent contained in the coating material 30 stored in the coating material storage tank 51. It is a system that discharges gas in the gas phase part of the paint storage tank 51 or supplementary gas such as air or inert gas supplied through the gas supplementing pipe 54 to the liquid phase part and bubbles it. The organic solvent 31 stored in the organic solvent storage tank 53 is not necessarily the same as the organic solvent contained in the paint 30 stored in the paint storage tank 51, for example, included in the paint 30 stored in the paint storage tank 51. Any organic solvent containing components equivalent to the organic solvent may be used. The organic solvent storage tank 13 for storing the organic solvent 31 is supplied with gas such as dehumidified and purified air and inert gas through an gas supply pipe 14 from an external gas supply device (not shown).

  Connected to the lid 57 of the paint storage tank 51 are an exhaust pipe 58 through which gas in the gas phase portion of the paint storage tank 51 flows and a gas supply pipe 59 through which gas to be sent to the paint storage tank 51 flows. The exhaust pipe 58 and the gas supply pipe 59 are both connected to the organic solvent storage tank 53, but the opening end of the exhaust pipe 58 on the organic solvent storage tank 53 side is located at the lower part in the organic solvent storage tank 53, and the gas supply pipe 59 is provided. The opening end on the organic solvent storage tank 53 side is located above the organic solvent storage tank 53. Therefore, when the organic solvent 31 enters the organic solvent storage tank 53, the opening end of the exhaust pipe 58 on the organic solvent storage tank 53 side is located in the liquid phase portion, and the opening end of the gas supply pipe 59 on the organic solvent storage tank 53 side is the gas phase. Will be located in the part.

  The exhaust pipe 58 has a check valve 60 for preventing gas from flowing from the organic solvent storage tank 13 side to the paint storage tank 11A side, and a circulation fan 66 for sending the gas in the paint storage tank 51 to the organic solvent storage tank 53. Is provided. Further, the gas supply pipe 59 is provided with a check valve 61 for preventing gas from flowing from the paint storage tank 51 side to the organic solvent storage tank 53 side.

<How to use the second embodiment>
The paint storage system 50 according to the present invention configured as described above is used as follows, for example. An example of the usage method of the paint storage system 50 is shown in FIGS. For example, as shown in FIG. 5A, the paint storage tank 51 filled with the paint 30 saturates the vapor pressure of the organic solvent in the paint storage tank 51 by operating the paint storage system 50 as follows. It is possible to prevent the paint 30 attached to the inner wall surface of the paint storage tank 51 from being dried by the vapor pressure.

That is, the circulating blower 66 is operated to transfer the gas in the gas phase portion of the paint storage tank 51 to the organic solvent storage tank 53 through the gas supply pipe 58 (FIG. 5B). The gas in the gas phase part of the paint storage tank 51 is foamed in the organic solvent 31 of the organic solvent storage tank 53 and goes up to the gas phase part of the organic solvent storage tank 53, and passes through the gas supply pipe 59 to form the paint storage tank. To the top of 51. The gas transferred to the paint storage tank 51 is saturated with the components of the organic solvent 31 when passing under the organic solvent 31 in the organic solvent storage tank 53. Since the gas saturated with the components of the organic solvent 31 flows again into the paint storage tank 51 via the gas supply pipe 59, the vapor pressure of the organic solvent in the paint storage tank 51 is quickly increased to the saturated vapor pressure. To reach.

  Therefore, it is possible to prevent the generation of foreign matter by preventing the formation of a dry film of the paint 30 that remains attached to the inner wall surface of the paint storage tank 51.

  In addition, after operating the paint storage system 50 according to the present invention as described above to set the vapor pressure of the organic solvent in the paint storage tank 51 to the saturated vapor pressure, the paint 30 stored in the paint storage tank 51 is applied. When transferring to the apparatus, the gas supply valve of the gas replenishment pipe 54 to the organic solvent storage tank 13 is opened, and transfer is started while supplying gas. (FIG. 5C). When the gas supply valve of the gas replenishment pipe 54 is opened and the transfer of the paint 30 to the coating device is started, the gas bubbling to the organic solvent 31 in the organic solvent storage tank is stored in the paint via the gas supply pipe 59. It is introduced into the tank 51. Therefore, the concentration of the solvent component of the gas in the paint storage tank 51 saturated with the organic solvent component does not decrease, so that the vapor pressure of the organic solvent in the paint storage tank 51 is maintained at the saturated vapor pressure. The formation of 30 dry films can be prevented and the generation of foreign matter can be prevented. As a result, the formation of a dry film on the inner wall surface of the paint storage tank is prevented to prevent the generation of foreign matters, and the concentration fluctuation of the paint 30 is suppressed, whereby the paint 30 containing a volatile organic solvent can be used for a long time. It is possible to store stably for a long time.

10, 50 ··· Paint storage systems 11A, 11B, 51 ·· Paint storage tanks 12 and 52 · · Gas supply piping system 13, 53 · · Organic solvent storage tanks 14 and 54 · · Gas replenishment pipe 15 · · Paint supply piping 16 ..Transfer pumps 17A, 17B, 57..Lids 18A, 18B, 58..Exhaust pipes 19A, 19B, 59..Gas supply piping 20A, 20B, 60, 21A, 21B, 61..Check valve 25 .. Paint discharge pipe 30 .. Paint 31.. Organic solvent 32. Organic solvent vapor 66.

Claims (6)

A paint storage system for storing paint containing a volatile organic solvent,
A paint storage tank having an airtight structure for storing the paint;
An organic solvent storage tank having an airtight structure storing an organic solvent containing the same or equivalent component as the organic solvent;
A paint storage system comprising: a gas supply pipe for supplying a gas bubbled to the organic solvent in the organic solvent storage tank to the top of the paint storage tank. The paint storage tank is provided in a plurality, and is composed of two systems of A series and B series, each of the A series and the B series is composed of one or a plurality of paint storage tanks,
The paint stored in any one of the one or a plurality of A-series paint storage tanks is used as the paint storage in any one of the other one or a plurality of B-series paint storage tanks. Paint supply piping to be transferred to the tank;
After the gas in the gas phase part of any one of the one or more B-series paint storage tanks is bubbled into the organic solvent in the organic solvent storage tank, the other one or more The paint storage system according to claim 1, further comprising: a gas supply pipe that transfers to the top of any one of the A-series paint storage tanks.   The paint storage system warms the organic solvent in the organic solvent storage tank so that the temperature of the organic solvent in the organic solvent storage tank is at least higher than the temperature of the paint in the paint storage tank. The paint storage system according to claim 1, further comprising means. A paint storage method for storing a paint containing a volatile organic solvent,
Gas bubbled in an organic solvent storage tank having an airtight structure in which an organic solvent containing the same or equivalent component as the organic solvent is stored is supplied to the top of the paint storage tank having an airtight structure for storing the paint. A paint storage method comprising: supplying a paint. A plurality of the paint storage tanks are provided,
A gas supply pipe capable of transferring the gas in the gas phase of any one of the plurality of paint storage tanks to the top of any one of the other paint storage tanks; The gas in the gas phase part of the paint storage tank pushed out by transferring the paint in any one of the paint storage tanks to any of the other paint storage tanks is converted into the organic solvent in the organic solvent storage tank. The paint storage method according to claim 4, wherein the paint storage method is carried out by bubbling with a solvent and supplied to the top of at least one of the plurality of paint storage tanks.   The paint is stored in a gas bubbled in the organic solvent storage tank having an airtight structure in which the organic solvent heated to be higher than the temperature of the paint is stored in at least the paint storage tank. The paint storage method according to claim 4 or 5, wherein the paint storage tank is supplied to a top portion of the paint storage tank having an airtight structure.

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