JP2010078004A - Liquid feeding method and application method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid feeding method capable of absorbing or reducing pulsation through a very small pressure fluctuation, and an application method without uneven application. <P>SOLUTION: Very small pulsation is absorbed or reduced by arranging a first pulsation absorbing device 56 including a liquid chamber 103 for making liquid flow in and out to part of a liquid sending pipe for feeding the liquid to the other side from one side, an air chamber 104 for introducing gas, and an elastic film 115 for isolating the liquid chamber 103 and the air chamber 104 and constituted of a raw material having a JIS hardness of 60 or more and an elongation of 175% or less in 25°C-atmospheric pressure-humidity 50% RH. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid feeding method and a coating method, and more particularly to a liquid feeding method and a coating method that can prevent or reduce pulsation that occurs in the liquid feeding process.

  Conventionally, when pulsation occurs in the liquid feeding process, there is a problem that, for example, coating unevenness occurs or vibration noise occurs.

In order to solve this problem, Patent Document 1 describes a method using a mechanism that absorbs pulsation by adjusting the gas pressure isolated by a thin film during liquid feeding. Patent Document 2 describes a method of suppressing pressure fluctuation by reducing the clearance between the valve body and the sliding portion to increase the sliding resistance.
JP 2006-156655 A JP 11-270429 A

  However, in the method of Patent Document 1, although pulsation can be precisely controlled, it is necessary to prepare an absorption capacity corresponding to the fluctuation, and when the flow rate increases, the device becomes large and a secondary failure may occur due to retention in the device. Yes, there was a need to clean in the middle.

  In the method of Patent Document 2, it is necessary to maintain a very narrow clearance of several μm, and it is necessary to install a dedicated filter having a large pressure loss in the liquid feeding process in order to prevent clogging.

  It is also known that it is effective to provide a throttle mechanism such as an orifice in the liquid feeding path in order to suppress pulsation propagation (pressure fluctuation) in the liquid feeding process.

  However, there is a case where it cannot be attenuated by the throttling mechanism or a new pulsation may occur when passing through the throttling mechanism, and it is possible to suppress minute pressure fluctuations and perform uniform liquid feeding or uniform liquid feeding. Therefore, a coating method capable of making the film thickness uniform has been demanded.

  The present invention has been made in view of such problems, and an object thereof is to provide a liquid feeding method capable of absorbing pulsation due to minute pressure fluctuations, and a coating method without coating unevenness.

  In order to achieve the object, the liquid feeding method of the present invention includes the step of supplying a liquid from one side of the liquid feeding pipe, and the first pulsation absorbing device provided in a part of the liquid feeding pipe. A liquid feeding method including a step of absorbing pulsation of liquid and sending it out to the other side of the liquid feeding pipe, wherein the first pulsation absorbing device includes a liquid chamber through which liquid flows in and out, and gas is introduced. An elastic film made of a material having a JIS hardness of 60 or more and an elongation of 175% or less at 25 ° C., atmospheric pressure and humidity of 50% RH, which separates the gas chamber from the liquid chamber and the gas chamber It is characterized by providing.

  A first pulsation absorbing device provided with an elastic membrane made of a material having a JIS hardness of 60 or more and an elongation of 175% or less at 25 ° C., atmospheric pressure, and humidity of 50% RH is provided in a part of the liquid supply piping. Therefore, minute pulsations (pressure fluctuations) can be absorbed or reduced.

  For example, when a minute pulsation that could not be absorbed by a pulsation absorber installed in the middle of a liquid supply pipe and that can absorb a large pulsation (pressure fluctuation), or a minute pulsation caused by the pulsation absorber occurs. Can also be absorbed or reduced by the first pulsation absorber.

  In the liquid feeding method of the present invention, in the above invention, the pulsation is absorbed by increasing the pressure in the liquid feeding pipe only on the upstream side of the first pulsation absorbing device and on a part of the liquid feeding pipe. Preferably, a second pulsation absorbing device is provided.

  The large pulsation generated in the liquid feeding process is absorbed or reduced by the second pulsation absorbing device that absorbs the pulsation by increasing the pressure in the liquid feeding pipe, and the minute pulsation that could not be absorbed by the second pulsating absorbing device. The pulsation or minute pulsation caused by the second pulsation absorbing device can be absorbed or reduced by the first pulsation absorbing device.

  In the liquid feeding method of the present invention, in the above invention, a gas having an atmospheric pressure of ± 0.03 MPa is preferably introduced into the gas chamber of the first pulsation absorber.

By introducing a gas at atmospheric pressure ± 0.03 MPa into the gas chamber, the amount of displacement of the elastic membrane can be secured,
Micro vibrations can be effectively absorbed or reduced.

  In the liquid feeding method of the present invention, in the above invention, the elastic film is preferably made of a fluorine-based material. This is because the fluorine-based material is a material excellent in solvent resistance and is suitable for the material of the elastic film.

  In order to achieve the above object, a coating method of the present invention includes a step of feeding a coating liquid to a coating apparatus by the liquid feeding method, and a step of supplying the coating liquid from the coating apparatus to a substrate. It is characterized by including.

  According to the present invention, it is possible to effectively absorb or reduce the liquid supply pulsation of the coating liquid. Thereby, a uniform coating film can be formed in a thin layer on the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid feeding method which can absorb the pulsation by a micro pressure fluctuation, and the coating method without a coating nonuniformity can be provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described with reference to the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments than the present embodiment can be used. be able to. Accordingly, all modifications within the scope of the present invention are included in the claims.

In addition, the numerical range represented by using “to” in this specification means a range including the numerical values described before and after “to”. FIG. 1 shows an optical to which the liquid feeding method according to the invention is applied. It is a block diagram which shows the application | coating process 10 of the manufacturing line of a film. This optical film production line includes a coating process and a drying process (others) between a process of continuously feeding a roll-shaped support film (hereinafter referred to as “web”) W and a process of winding the web W. In addition, a necessary number of steps for curing the coating film are appropriately installed.

  In the coating step 10 shown in FIG. 1, a slot die 12 is provided so as to face the coating roller 11 around which the web W is wound at the coating position. The slot die 12 is connected to a coating liquid tank 40 that stores the coating liquid 14 by a liquid feeding pipe 42. The coating liquid 14 is supplied to the slot die 12.

  In the liquid supply pipe 42, a liquid supply pump 46, a pressure gauge 48, a vacuum degassing device 50 with a filtration filter, a flow meter 52, a second pulsation absorption device 54, and a first pulsation absorption device 56 are sequentially provided from the upstream side. It is connected.

  The liquid feeding pipe 42 is preferably made of a metal member having an inner diameter of 15 mm or less and having a straight-shaped fluororesin or an inner peripheral portion polished. As described above, if a straight-shaped fluororesin (for example, “Teflon (registered trademark)”) or a metal member whose inner peripheral portion is polished is used for the small-diameter liquid feeding pipe 42, the flow of the coating liquid 14 in the pipe Is effective, and is effective in eliminating bubbles.

  In addition, in order to eliminate liquid pulsation from the liquid supply line, it is desirable that the liquid supply pipe 42 in front of the second pulsation absorbing device 54 reduce the propagation of vibration. It is preferable to use a resin (for example, a trade name: “Teflon (registered trademark)”), 2) a bellows-like pipe having a small thickness, or 3) an anti-vibration material.

  Various known types of pumps (gear pumps, etc.) can be used as the liquid feed pump 46, but a diaphragm pump can be preferably used. That is, as in the present invention, when a pressurized state is generated in the slot die 12 and in the liquid feeding pipe 42, the liquid feeding pump 46 for feeding the coating liquid 14 is preferably a diaphragm pump.

  Depending on the type of gear pump, there is a case where the coating liquid 14 cannot be satisfactorily fed due to a phenomenon called “through”. Further, when the molecules in the coating liquid 14 are large (for example, 1 μm or more), there is a possibility of causing molecular shearing or gear breakage by meshing of the gear.

  As the pressure gauge 48, various known types of pressure gauges and flow meters can be used.

  As the vacuum filter degassing device 50 with a filtration filter, one having an appropriate specification can be adopted according to the composition of the coating solution.

  Various known types of flow meters can be used as the flow meter 52, but a Coriolis flow meter can be preferably used.

  FIG. 2 is a configuration diagram showing an outline of the first pulsation absorbing device. 2A is a side cross-sectional view, and FIG. 2B is a front cross-sectional view.

  The first pulsation absorbing device 56 includes a main body A101, a main body B102, and an elastic film 115 disposed between the main body A101 and the main body B102.

  A concave portion is formed in the main body A101, and the liquid chamber 103 is configured by the concave portion and the elastic film 115. The inflow path 108 is connected to the liquid chamber 103 via the inlet 106 to supply the liquid to the liquid chamber 103. An inflow passage 109 is connected to the liquid chamber 103 via the outlet 107 to discharge the liquid. The liquid to be fed fills the liquid chamber 103, the inflow path 108, and the inflow path 109.

  A concave portion is formed in the main body B102, and the air chamber 104 is configured by the concave portion and the elastic film 115. The pressure adjustment buffer 120 is connected via a vent hole 110 formed in the main body B102.

  The liquid chamber 103 and the air chamber 104 are separated by the elastic film 115 disposed between the main body A101 and the main body B102.

In the present invention, the elastic film 115 is made of a material having characteristics of JIS hardness 60 or more and elongation 175% or less under 25 ° C., atmospheric pressure, and humidity 50% RH. Since the material having the above characteristics is selected as the elastic film 115, it is possible to effectively absorb minute pulsations generated in the liquid feeding process, for example, about 20 Pa.

  According to the material in the above range, there is a certain degree of hardness and elongation restrictions, so that it is not easily stretched by the liquid feeding pressure and the elastic residual force of the film is not lost. Further, as the method of use, since the pressure on the side opposite to the liquid contact with the membrane is almost atmospheric pressure, the pulsation can be absorbed by the minute fluctuation of the film even when the fluctuation of the film is caused by the minute pulsation.

  The elastic film 115 is preferably a material excellent in solvent resistance, such as a fluorine-based material.

  As specific examples of the material of the elastic film 115 having the above-described characteristics, fluororubber (Viton), fluororubber (Aphras), fluororubber (Dinion), and the like can be used. In particular, from the viewpoint of solvent resistance, it is preferable to use fluororubber (Dai-El Perflo).

  The elastic film 115 is fixed by sandwiching the periphery of the elastic film 115 between the main body A101 and the main body B102. The elastic film 115 is flexible due to its characteristics as described above. Therefore, when a liquid with pulsation flows into the liquid chamber 103, the elastic film 115 is displaced in response to the pulsation.

  On the other hand, the air chamber 104 is set so that its internal pressure becomes substantially atmospheric pressure. In the present embodiment, for example, the atmospheric pressure is adjusted to be ± 0.03 MPa. When the elastic film 115 is displaced due to pulsation, the volume of the air chamber 104 changes. However, the volume change is absorbed by the pressure adjustment buffer 120 connected via the vent hole 110.

  The internal pressure of the air chamber 104 can be adjusted by opening a part of the pressure adjustment buffer 120, connecting a regulator to the pressure adjustment buffer 120, making the pressure adjustment buffer 120 a closed system, and making the volume relatively large. Done. In any case, it is only necessary that the pressure adjustment buffer 120 can absorb the displacement of the elastic film 115 due to pulsation.

  As long as the elastic film 115 is displaced by pulsation, the elastic film 115 does not have to be positioned at the center of the main body A101 and the main body B102. That is, the elastic film 115 may be displaced to the liquid chamber 103 side or the air chamber 104 side.

  Further, instead of the elastic membrane 115, the same material as that of the elastic membrane may be used to seal the gas of a fixed volume. The first pulsation absorbing device may be configured to contact the elastic bag and the liquid. In this case, when the gas in the closed system is dissolved in the liquid to be used, it is preferable to add a gas replenishment system because the effect can be maintained for a long time.

  In the first pulsation absorbing device 56, the inlet 106 is provided on the bottom side of the liquid chamber 103, and the outlet 107 is provided on the upper side of the liquid chamber 103. By setting the inflow port 106 to the bottom side, bubbles or the like generated when the liquid flows in are moved to the upper side without staying at the bottom of the liquid chamber 103. Bubbles or the like that have moved to the upper side are discharged from the outlet 107 along with the liquid. Thereby, it is possible to prevent bubbles and the like from staying in the liquid chamber 103 and causing bubbles to be pushed out during application and mixed into the application liquid to cause foam failure.

  Next, a second pulsation absorbing device that absorbs pulsation by increasing the internal pressure of the liquid feeding pipe will be described. An orifice is used as the second pulsation absorbing device, and the orifice is installed in a part of the liquid feeding pipe.

  FIG. 3 is an explanatory diagram for explaining the orifice. FIG. 3A is a perspective view of the orifice 70, and FIG. 3B is a cross-sectional view of the orifice 70. The orifice 70 is a type in which one hole is provided in a slit plate F having a thickness L.

  In FIG. 3B, S is a cross-sectional area of the liquid feeding pipe 42, Sd is a hole cross-sectional area of the slit plate F, A is an amplitude of an approaching wave to the orifice 70 (slit plate F), and B Is the amplitude of the wave after entering. The transmission loss TL due to the orifice 70 is expressed by the following formula 1.

  Here, m is the ratio of the cross-sectional area S of the liquid feeding pipe 42 and the hole cross-sectional area Sd of the slit plate F, k is a term depending on the substance inside the liquid feeding pipe 42, and f is the frequency of the sound wave. Where c is the speed of sound in the medium and depends on the viscosity and density of the medium.

  Further, the transmission loss TL by the orifice 70 is also expressed by the following formula 2 by the values A and B in FIG.

  As can be seen from the above formulas 1 and 2, it is understood that the wave propagation after passing through the orifice 70 attenuates as the frequency f and the hole cross-sectional area Sd of the slit plate F are reduced. Therefore, by introducing the orifice 70, the liquid feeding pulsation of the coating liquid can be effectively suppressed.

  In the above formula 1, it is preferable that the area ratio (1 / m) between the hole cross-sectional area Sd of the orifice 70 and the cross-sectional area S of the liquid feeding pipe 42 on the upstream side of the orifice 70 is 0.1 or less. .

  As described above, an “orifice” is generally a circle with holes for measuring the flow rate by detecting the changed pressure by inserting it in the middle of the pipe to restrict the flow path. Although it refers to a plate, in this specification, it is applied to control of flow rate, not to measurement of flow rate.

  For example, in the present embodiment, a type in which one hole is provided in the slit plate F is used as the orifice 70, but various other modes can be adopted. An example of this is shown in FIG. FIG. 4A shows a type in which a plurality of holes are provided in the orifice 70. FIG. 4B is a type in which one orifice is provided in the orifice 70. Thus, even if the orifice 70 is porous or tapered, the same effect as in the present embodiment can be obtained.

  When the orifice 70 having a reduced pipe diameter is used as the second pulsation absorbing device, the liquid flow may become turbulent when the liquid passes through the throttle portion. As another means, there is a drawback that the apparatus becomes large, but a large-capacity buffer or the like may be used.

  By this second pulsation absorbing device, relatively large pulsations such as pump and deaeration fan vibrations can be efficiently eliminated.

  As the second pulsation absorber, it is preferable to install an orifice only upstream of the first pulsation absorber. The second pulsation absorbing device is suitable for absorbing a relatively large pulsation. Therefore, the large pulsation generated in the liquid feeding process is absorbed by the second pulsation absorbing device. It is preferable that the first pulsation absorbing device absorbs the minute pulsation that could not be absorbed by the second pulsation absorbing device or the minute pulsation caused by the second pulsation absorbing device.

  Next, the coating method according to the coating step 10 will be described.

  As the web W (base material) used for an optical film such as an antireflection film, a transparent plastic film is preferably used. Examples of plastic film materials include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate). , Poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, Polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, polymethyl It includes methacrylate and polyether ketone.

  In particular, triacetyl cellulose is preferably used. As the triacetyl cellulose film, a known film such as TAC-TD80U (manufactured by FUJIFILM Corporation), or a film published in published technical report number 2001-1745 is preferably used.

  The light transmittance of the web W is preferably 80% or more, and more preferably 86% or more. The haze of the web W is preferably 2.0% or less, and more preferably 1.0% or less. The refractive index of the web W is preferably 1.4 to 1.7.

  Although the thickness of the web W is not specifically limited, 30-150 micrometers is preferable, 40-130 micrometers is more preferable, 70-120 micrometers is still more preferable.

  The dispersion medium for the coating liquid is not particularly limited. You may use individually or in mixture of 2 or more types.

  Preferred dispersion media include aromatic hydrocarbons such as toluene, xylene and styrene, chlorinated aromatic hydrocarbons such as chlorobenzene and orthodichlorobenzene, methane derivatives such as monochloromethane, ethane derivatives such as monochloroethane, and the like. Chlorinated aliphatic hydrocarbons, alcohols such as methanol, isopropyl alcohol and isobutyl alcohol, esters such as methyl acetate and ethyl acetate, ethers such as ethyl ether and 1,4-dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone, Examples include ketones such as cyclohexanone, glycol ethers such as ethylene glycol monomethyl ether, alicyclic hydrocarbons such as cyclohexane, aliphatic hydrocarbons such as normal hexane, and mixtures of aliphatic or aromatic hydrocarbons.

  Among these solvents, a dispersion medium for coating prepared by alone or mixing two or more ketones is particularly preferable.

  In the coating method of the present invention, the upper limit speed at which coating is possible is greatly affected by the liquid physical properties, so it is necessary to control the liquid physical properties, particularly the viscosity and surface tension at the moment of coating.

  The viscosity is preferably 3 (mPa · s) or less, more preferably 2.5 (mPa · s) or less, and still more preferably 2.0 (mPa · s) or less.

  Depending on the coating solution, the viscosity may change depending on the shear rate, and the above value indicates the viscosity at the shear rate at the moment of application. When a thixotropic agent is added to the coating solution, the viscosity is low when coating with high shear and the viscosity is high when drying where the coating solution is hardly sheared.

Moreover, although it is not a liquid physical property, the quantity of the coating liquid apply | coated to a web also affects the upper limit speed | rate which can be apply | coated. The amount of the coating solution applied to the web is preferably 2.0 to 10.0 ml / m ² . Increasing the amount of the coating liquid applied to the web is preferable because the upper limit of the coating speed can be increased. However, if the amount of the coating liquid applied to the web is excessively increased, the load on drying increases. -It is preferable to determine the optimal amount of coating solution to be applied to the web according to the process conditions.

  The surface tension is preferably in the range of 15 to 36 mN / m. It is preferable to reduce the surface tension by adding a leveling agent or the like because unevenness during drying is suppressed. On the other hand, if the surface tension is too low, the upper limit speed at which coating is possible decreases, so the range of 17 to 32 mN / m is more preferred, and the range of 19 to 26 mN / m is even more preferred.

  Hereinafter, the process of applying the coating liquid will be described.

  The coating liquid 14 pressure-fed from the coating liquid tank 40 by the liquid feeding pump 46 includes a second pressure indicator 48, a vacuum degassing device 50 with a filter, a flow meter 52, a second pulsation absorbing device 54, and a first pressure absorber. It is supplied to the slot die 12 through the pulsation absorbing device 56 and the liquid feeding pipe 42. Since the first pulsation absorbing device 56 and the second pulsation absorbing device 54 are provided on the upstream side of the slot die 12, the liquid supply pulsation of the coating liquid can be effectively suppressed.

  A coating film is formed on the web W by applying the coating liquid 14 as a bead from the slot die 12 to the web W continuously supported by the coating roller 11. At this time, since the liquid supply pulsation of the coating liquid is suppressed in the slot die 12, there is no planar defect due to the liquid pulsation, and coating with high film thickness uniformity can be performed.

  That is, when the coating liquid 14 was applied by the coating process 10 shown in FIG. 1, there were few streak defects and the film thickness uniformity was improved. Therefore, according to the present embodiment, it is possible to produce an optical film such as an antireflection film having no surface defects due to liquid pulsation and high film thickness uniformity.

  The present invention will be described more specifically with reference to the following examples. The materials, production conditions, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

<Coating solution>
The following composition was dissolved in 107 parts by mass of methyl ethyl ketone to prepare a coating solution. The viscosity of the coating solution was adjusted by adjusting the amount of methyl ethyl ketone added to adjust the solution viscosity to 2 mPa · s and the surface tension to 23 mN / m.
-Discotic liquid crystalline compound TE (1) ... 41.01 parts by mass-Ethylene oxide modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) ... 4.06 parts by mass-Cellulose acetate butyrate ( CAB551-0.2, manufactured by Eastman Chemical Co., Ltd .... 0.9 parts by mass, cellulose acetate butyrate (CAB531-1, manufactured by Eastman Chemical Co., Ltd.) ... 0.21 parts by mass, fluoroaliphatic group-containing polymer (Megafac) F780 Dainippon Ink Co., Ltd.) ... 0.14 parts by mass, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) ... 1.35 parts by mass, sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) ) ... 0.45 parts by mass

<Application conditions>
The example was performed in an example in which a coating solution for an optical compensation film was applied in the optical compensation film coating step 10 shown in FIG. Application was performed at an application speed of 40 m / min and a liquid feed flow rate of 385 cc / min or 200 cc / min.

  An orifice was used as the second pulsation absorbing device 54. The first pulsation absorbing device 56 is disposed on the downstream side of the orifice. The coating liquid was allowed to flow from the lower side to the upper side in the liquid chamber 103 in which the first pulsation absorbing device 56 shown in FIG. 2 was formed. The elastic film 115 was in contact with the liquid chamber 103, and was installed so that gas (air) was in contact with the opposite surface. The pressure fluctuation was measured with a micro differential pressure gauge A installed between the first pulsation absorbing device 56 and the slot die 12. The fine differential pressure gauge used was a high-precision pressure transmitter (model number: PTX620) manufactured by GE Sensing, and was connected to a data recorder (model number: NR-2000) manufactured by Keyence Corporation to measure liquid pulsation.

  The pulsation was measured after the pulsation absorber using the pulsation rate obtained by dividing the intensity peak of the pressure wave by the average pressure.

  The physical properties of the elastic film used in the first pulsation absorbing device 56 were changed in JIS hardness and elongation related to absorption. Table 1 summarizes the materials used in a list.

  Table 2 summarizes the coating conditions and evaluation results for Examples 1 to 7 and Comparative Examples 1 to 6 in a list.

  As an evaluation means, the pulsation was calculated by the calculation method as described above, and the value was described. As the evaluation of the coating film, the stepwise unevenness caused by the pulsation was compared with a sample and evaluated by sensory evaluation. The determination was made by integrating the pulsation level and the surface evaluation. ◎ is a good level as a product, ◯ is a level that can be used as a product, and x indicates a level that cannot be used as a product.

  For Examples 1 to 4 using materials satisfying the characteristics of JIS hardness 60 or more and elongation 175% or less at 25 ° C., atmospheric pressure, and humidity 50% RH, the pulsation has a low value. As a result, a result of ◯ or higher was obtained with respect to step unevenness and determination.

  On the other hand, Comparative Example 1 does not include the first pulsation absorbing device. Therefore, the pulsation was also large, and the evaluation was x regarding the step unevenness and the determination. Comparative Examples 2 to 4 are cases in which an elastic film that falls outside the range of the characteristics of the present invention is used. Even if the pressure of the air chamber was changed to atmospheric pressure, the evaluation was x regarding step unevenness and determination. That is, it indicates that the pulsation is not sufficiently absorbed.

  Examples 5 to 7 are cases where A is used as the material of the elastic membrane. The evaluation was performed by changing the pressure of the air chamber to (atmospheric pressure−0.03 MPa), (atmospheric pressure + 0.003 MPa), and (atmospheric pressure + 0.03 MPa) so that the pressure in the air chamber was approximately atmospheric pressure. As is clear from Table 2, Examples 5 to 7 gave results of ◯ or more with respect to step unevenness and determination.

  In Comparative Example 5, A is used as the material for the elastic membrane, and the first pulsation absorber is installed on the upstream side of the second pulsation absorber. In Comparative Example 6, A is used as the material for the elastic film, and the pressure in the air chamber is made larger than the atmospheric pressure.

  In Comparative Example 5, since the first pulsation absorbing device is installed on the upstream side of the second pulsation absorbing device, minute pulsation is generated by the second pulsation absorbing device. It was evaluation.

  In Comparative Example 6, since the pressure in the air chamber is large, the displacement amount of the elastic film is small. Therefore, it is shown that minute pulsations cannot be sufficiently absorbed.

  In Comparative Example 7, since the micro pulsation does not occur when the flow rate is small, the determination is an evaluation of “◯”.

The block diagram which shows the application | coating process of the coating method which concerns on this invention Schematic configuration diagram showing the first pulsation absorbing device Schematic configuration diagram showing a second pulsation absorbing device Schematic block diagram showing another example of the second pulsation absorbing device

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Application | coating process, 11 ... Coating roller, 12 ... Slot die, 42 ... Liquid supply piping, 46 ... Liquid supply pump, 48 ... Pressure gauge, 50 ... Depressurization deaerator with filtration filter, 52 ... Flow meter, 54 ... 1st 2 pulsation absorbing devices, 56 ... first pulsation absorbing device, 101 ... main body A, 102 ... main body B, 103 ... liquid chamber, 104 ... air chamber, 106 ... inflow port, 107 ... outflow port, 108 ... inflow channel, 109 ... Outflow passage, 110 ... Vent, 115 ... Elastic membrane, 120 ... Pressure adjustment buffer

Claims (5)

Supplying liquid from one side of the liquid delivery pipe;
A first pulsation absorbing device provided in a part of the liquid feeding pipe, absorbing the pulsation of the liquid and sending it to the other side of the liquid feeding pipe,
The first pulsation absorbing device separates the liquid chamber into and out of the liquid, the gas chamber into which the gas is introduced, and the liquid chamber and the gas chamber, at 25 ° C., atmospheric pressure, and humidity of 50% RH A liquid feeding method comprising: an elastic film made of a material having a JIS hardness of 60 or more and an elongation of 175% or less.   2. A second pulsation absorbing device that absorbs pulsation by increasing a pressure in the liquid feeding piping only on an upstream side of the first pulsation absorbing device and on a part of the liquid feeding piping. The liquid feeding method described.   The liquid feeding method according to claim 1, wherein a gas having an atmospheric pressure of ± 0.03 MPa is introduced into the gas chamber of the first pulsation absorbing device.   The liquid feeding method according to claim 1, wherein the elastic film is made of a fluorine-based material. A step of feeding the coating liquid to the coating apparatus by the liquid feeding method according to any one of claims 1 to 4,
Supplying the coating liquid from the coating apparatus to a substrate;
The coating method characterized by including.

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