JP2006198474A - Blade coating method and disk coating method using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blade coating method realizing stable coating of a coating liquid by a simple apparatus constitution, and a disc coating method using this, and to realize formation of a coating liquid layer having a good surface property by preventing dropping of the liquid and generation of a streak on a coating surface. <P>SOLUTION: In the blade coating method, a mask 25 having an opening 27 is superposed on an optical disc D, the coating liquid 49 is fed onto the mask 25, the mask 25 and the optical disc D are left from each other after the mask 25 is coated with the coating liquid 49 by a blade 51 relatively moved relative to the mask 25 above the mask 25 and the coating liquid layer 65 corresponding to the opening 27 of the mask 25 is formed on the optical disc D. A clearance G of the mask 25 and a lower surface 59 of the blade 51 is made to 20 μm-150μm and is made to 10%-50% of film thickness T of the coating liquid layer 65 applied on the optical disc D. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blade coating method for coating a flat substrate with a coating solution using a blade, and a disk coating method using the same.

  Various proposals have heretofore been made in order to stably apply a liquid paint to an application surface of a member to be applied. For example, in the coating apparatus disclosed in Patent Document 1 below, the coating liquid stored in a pocket made up of a side frame that is slidably contacted with an object to be coated and two blades that are interposed between the side frame is provided at the lower end of the blade on the downstream side in the traveling direction. Lubricating layer forming means is provided for forming a lubricating layer on the upper surface of the coated body, which is applied to the coated body by flowing out from the gap onto the coated body. Thereby, the slipperiness of the lower surface of the side frame is improved, and the occurrence of horizontal stripes continuous in the direction in which the blade passes on the coating surface is prevented.

  In addition, in the substrate coating apparatus disclosed in Patent Document 2 below, the substrate is sandwiched between a microrod bar whose lower part is immersed in a coating solution tank and a nip roller disposed opposite to the microrod bar. Thus, a coating liquid is applied to the lower surface of the substrate, and a push-up member that supports the front edge of the substrate from below and restricts the deflection of the front edge of the substrate is provided on the substrate entrance side of the microrod bar. As a result, the coating thickness in the vicinity of the center of the front edge of the substrate is prevented from becoming thicker than both sides, and coating is performed with a uniform coating thickness. In addition, the vicinity of the center of the rear edge of the substrate is prevented from coming into contact with the cough on the outlet side of the coating solution tank, and coating is performed with a uniform coating thickness.

  Furthermore, in the roll coater disclosed in Patent Document 3 below, a transport base and a coating roll for transporting a thin plate to be coated are provided, and the liquid agent is moved to the surface of the thin plate by moving the transport base below the coating roll. The carrier plate is placed on the upper surface of the substrate with a grip plate for gripping the thin plate with a gap interposed therebetween, and the center of the thin plate is placed in the middle of the surface direction of the gap in a line segment passing in the moving direction of the carrier table. On the other hand, the elastic material is arranged symmetrically with respect to the line, and the periphery of the gripping plate is regulated by the gap regulating means so that the gap can be adjusted. As a result, when the gripping plate presses and passes the coating roll, the reaction force (elastic force) of the elastic material is controlled so as to relax within the range of the gap and relieve the impact at the time of contact intrusion. The accompanying coating unevenness is prevented.

JP 63-224761 A Japanese Patent Laid-Open No. 9-10646 JP-A-10-128221

  FIG. 9 shows a conventional disk coating apparatus 1 that forms a printable coating liquid layer (ink receiving layer) 9 by coating a coating liquid on a disk-shaped recording medium such as an optical disk to a thickness of about 100 μm. There is something to show. This disk coating apparatus 1 includes a suction plate 2 for sucking and mounting an optical disk D, an air cylinder 3 for moving the optical disk D in the vertical direction together with the suction table 2, and a mask plate having an opening 8 defined by a circular edge 4a ( (Mask) 4 and a mask plate 4 and a blade 5 that forms a coating liquid layer 9 by applying the coating liquid 6 to the optical disc D by being driven horizontally while maintaining a predetermined gap.

  As shown in FIG. 9A, the application of the coating liquid 6 by the disk coating apparatus 1 is performed by placing the optical disk D on the suction table 2 and fixing it by suction, and then operating the air cylinder 3 to operate the optical disk. D is raised, whereby the mask plate 4 is overlaid on the optical disk D. Then, while supplying the coating liquid 6 onto the mask plate 4, the blade 5 is relatively moved in the direction of arrow A above the mask plate 4, whereby the coating liquid 6 is applied to the optical disk D exposed from the opening 8 of the mask plate 4. Apply to surface 7. Next, as shown in FIG. 9B, the air cylinder 3 is actuated to lower the suction table 2 (in the direction of arrow B) to separate the optical disk D from the mask plate 4, and the opening of the mask plate 4 on the optical disk D is opened. A coating liquid layer 9 corresponding to 8 is formed.

  However, although the coating apparatus disclosed in Patent Document 1 can be configured with a simple structure, a part of the coating tool is supported on the coated body, and the relative relationship between the downstream blade and the coated body is determined. In order to perform the coating while maintaining a proper interval, the coated body is limited to a belt-like body, and there is a defect that uncoated portions are formed on both ends of the blade.

  In addition, since the substrate coating apparatus disclosed in Patent Document 2 nips a substrate and performs coating with a microrod bar from the lower side, coating in the entire width direction is possible, but the object to be coated is a strip or rectangular shape. Limited to shapes. And when the thickness of the liquid film is increased, there is a problem in that the beads are disturbed on the downstream side of the microrod bar and streaks are generated on the coating surface.

  Furthermore, the roll coater disclosed in Patent Document 3 enables the application of a disk-shaped object to be coated, and also allows the entire surface of each coated body to be coated, but in order to support each of the coated bodies with an elastic body, If the equipment becomes large and, in addition to this, the liquid film thickness increases, there is a problem that streaks occur as in the case of the substrate coating apparatus described above.

  As described above, in the conventional technology, when the apparatus becomes large, or particularly when the coating thickness is increased, the amount of the coating liquid pushed into the gap between the blade and the coating surface increases, and the blade is distorted to cause the coating direction. As shown above, streaks substantially parallel to the coating direction are generated, and it becomes difficult to ensure a good coating surface. There were drawbacks.

  Further, in the conventional disc coating apparatus 1 shown in FIG. 9, since the coating liquid 6 is applied to the coating surface 7 of the optical disc D relatively thickly, a gap between the lower surface 5a of the blade 5 and the upper surface of the mask plate 4 is formed. If it is widened, it will be difficult to apply uniformly because liquid sagging occurs in the applied coating liquid layer 9. In addition, since the coating liquid 6 applied on the mask plate 4 is discarded instead of the coating liquid layer 9 of the optical disc D, the coating liquid 6 is wasted and the coating liquid 6 is efficiently used. There was a problem that could not be used. In order to avoid the above problem, when the gap between the lower surface 5a of the blade 5 and the upper surface of the mask plate 4 is narrowed, streaks substantially parallel to the coating direction of the blade 5 are generated in the coating liquid layer 9, and a good coating surface is obtained. There was a drawback that it was difficult to ensure.

  The present invention has been made in view of the above situation, and provides a blade coating method and a disk coating method using the blade coating method that enable stable coating of a coating solution with a simple apparatus configuration. An object of the present invention is to prevent formation of streaks on the surface and to form a coating liquid layer having good surface properties.

The above object of the present invention can be achieved by the following configuration.
(1) After a mask having an opening is overlaid on a flat substrate, a coating solution is supplied onto the mask, and the coating solution is applied onto the mask by a blade that moves relative to the mask above the mask. A blade coating method for forming a coating liquid layer corresponding to the opening of the mask on the planar substrate by separating the mask and the planar substrate, wherein a gap between the mask and the lower surface of the blade is 20 μm. A blade coating method characterized by a thickness of ˜150 μm.

  According to such a blade coating method, since the gap between the mask and the lower surface of the blade is set to 20 μm to 150 μm, dripping or streaking of the coating liquid layer is prevented, and the surface property of the coating liquid layer is flat. In addition, the thickness can be made uniform. Thereby, a coating liquid layer having a good surface property can be formed. Furthermore, it is possible to effectively use the coating liquid while minimizing the wasteful coating liquid.

  (2) A disk coating method, wherein at least one layer of a printing surface of a disk-shaped recording medium is formed by the blade coating method according to (1).

  According to such a disk coating method, a uniform and high-quality coating liquid layer is formed by forming at least one layer of the printing surface of the disk-shaped recording medium using a coating apparatus capable of coating a large area. can do. Accordingly, for example, a printing layer (ink receiving layer) for performing printing using an ink jet printer can be formed with a thickness having a necessary and sufficient ink receiving capability.

  According to the blade coating method and the disk coating method using the blade coating method of the present invention, it is possible to prevent the coating liquid layer from dripping and streaking and to form a coating liquid layer having a good surface property. Furthermore, the coating liquid that is not applied to the flat substrate and is wasted can be suppressed to a minimum, and the coating liquid can be used effectively. This also makes it possible to form a uniform and high-quality coating solution layer on the printing surface of the disk-shaped recording medium.

A blade coating apparatus suitable for achieving the blade coating method and the disk coating method using the same according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a block diagram showing an outline of a coating apparatus according to the present invention, FIG. 2 is a perspective view showing an outline of the appearance of the coating apparatus shown in FIG. 1, and FIG. FIG.

The blade coating apparatus 100 according to the present embodiment is used for coating a liquid film using, for example, a disk-shaped recording medium that is an example of a flat substrate, for example, an optical disk D as a member to be coated.
First, the configuration of the blade coating apparatus 100 will be described.
As shown in FIG. 1, the applicator 11 of the blade applicator 100 is provided with a circular suction table 13 on which the optical disk D can be sucked and placed. A plurality of suction holes 15 are opened on the upper surface of the suction table 13, and a vacuum pump 19 is connected to each suction hole 15 via a suction path 17. The suction table 13 can hold the optical disk D on the upper surface through the suction holes 15 by operating the vacuum pump 19.

Further, the suction table 13 is supported by the lifting shaft 21 so that the center of the lower surface is movable in the vertical direction. The vertical movement of the elevating shaft 21 is performed by driving an air cylinder 23 which is an example of a mask peeling means.
A mask plate (mask) 25 is provided above the suction table 13, and the mask plate 25 has an opening 27 for exposing the application surface 57 of the optical disk D. The optical disk D placed on the suction table 13 is covered with the opening peripheral edge 25 a of the mask plate 25 when the elevating shaft 21 is raised by driving the air cylinder 23 and reaches the upper limit position.

  The coating unit 11 is provided with a mask cap attaching / detaching means 29 above the center of the optical disc D. The mask cap attaching / detaching means 29 includes a cap suction nozzle 31, a vacuum pump 33, and an elevating means 35. The mask cap attaching / detaching means 29 sucks and holds the mask cap 37 at the lower end of the cap suction nozzle 31 by driving the vacuum pump 33. When the elevating means 35 is driven in this state, the cap suction nozzle 31 is lowered, and the mask cap 37 is inserted into the hole in the center of the optical disc D. The mask cap (center cap) is not limited to this, and may be detached by other mechanical means. For example, there is a method in which the mask cap 37 is pushed up from below and lifted from the mask plate 25, and the mask cap 37 is scooped from the side.

A coating liquid supply means 41 is provided above the mask plate 25 outside the opening 27. The coating liquid supply means 41 includes a coating liquid supply nozzle 43, a coating liquid supply device 45, and a nozzle lifting / lowering device 47. The coating solution supply means 41 supplies the coating solution 49 supplied from the coating solution supply device 45 dropwise onto the mask plate 25 from the coating solution supply nozzle 43. At this time, the coating liquid supply nozzle 43 is moved to the height near the mask plate 25 by the nozzle lifting / lowering device 47 only when the coating liquid 49 is dropped and supplied, and normally rises to a position where it does not interfere with the coating process and is in a standby state It is said.
Here, as the coating liquid 49, for example, one having a liquid viscosity of 150 cP to 800 cP can be used, and in particular, the coating liquid 49 of 200 cP to 600 cP is preferably used.

A blade 51 is arranged in a standby state further outside the coating liquid 49 supplied onto the mask plate 25 by the coating liquid supply means 41. The blade 51 is horizontally driven on the mask plate 25 while maintaining a predetermined gap G by the moving means 53, and is exposed through the opening 27 of the mask plate 25 as shown in FIG. It moves so that the coating liquid 49 may be apply | coated to the application | coating surface 57 of the optical disk D made.
As shown in FIG. 3, the gap G between the lower surface 59 of the blade 51 and the mask plate 25 is set to 20 μm to 150 μm.

  The blade 51 is made of a metal material such as a stainless steel material that is elongated in the direction perpendicular to the paper surface of FIG. 1, and the cross-sectional shape perpendicular to the longitudinal direction of the blade 51 is formed in a substantially trapezoidal shape. Further, a gap (gap) G is formed between the lower surface 59 of the blade 51 and the mask plate 25, and the coating liquid 49 is pressed as the flow is guided by the front side surface 55 of the blade 51. It is pushed into the gap G. Then, the coating liquid 49 is filled in the opening 27 of the mask plate 25 by passing through the lower surface 59 of the blade 51 facing the coating surface 57. As a result, the coating liquid 49 is applied to the coating surface 57 flatly.

  The operations of the vacuum pump 19, the air cylinder 23, the vacuum pump 33, the lifting / lowering means 35, the coating liquid supply device 45, the nozzle lifting / lowering device 47, and the moving means 53 are controlled by the control unit 63.

  Further, the opening 27 of the mask plate 25 has an opening exceeding at least 50 mm continuous along the longitudinal direction of the blade 51, so that the effect of uniform application by the blade application according to the present invention, which will be described in detail later, becomes remarkable. . In the present embodiment, the opening 27 is formed in a circular shape having a diameter of about 120 mm.

  In the blade coating apparatus 100 according to this embodiment, the coating liquid layer 65 is coated with a film thickness T of at least 100 μm at the time of coating. In the case of such coating having a thickness of 100 μm or more, the surface property of the coating liquid layer 65 is less likely to follow the surface of the coating surface 57 and the shape of the blade 51 is greatly affected as compared with the case of coating a thin film. Will be affected. That is, the surface of the coating liquid layer 65 is determined by the pressure of the coating liquid 49 by the blade 51 and the wettability of the coating liquid 49 by the blade 51 shape.

  When this blade coating apparatus 100 is used as a disk coating apparatus for forming at least one recording layer of a disk-shaped recording medium (optical disk), for example, a printing layer (ink receiving layer) for performing printing using an inkjet printer. Can be formed. According to this disk coating apparatus, it is possible to form a printing layer having a necessary and sufficient thickness so that good color reproducibility can be ensured when printing on the printing layer. Actually, when the coating liquid layer has a thickness of about 150 μm at the time of coating, a coating film of about 30 μm is formed when the coating is reduced after drying, and the ink receiving layer of about 30 μm enables good color reproducibility. .

Next, a coating solution coating method using the blade coating apparatus 100 will be described.
FIG. 4 is an explanatory diagram showing the procedure of the coating method according to the present invention as (a) to (c), and FIG. 5 is an explanatory diagram showing the procedure of the coating method according to the present invention as (d) to (g). FIG. 6 is a plan view of a member to be coated after coating.

  First, as shown in FIG. 4A, the optical disk D is adsorbed on the adsorption table 13 at the lowered position of the elevating shaft 21, as shown in FIG. 4A, and an air cylinder is obtained as shown in FIG. The suction table 13 is lifted by the drive of 23 and the optical disk D comes into contact with the opening peripheral edge 25 a of the mask plate 25. Next, as shown in FIG. 4C, the mask cap 37 is inserted into the center hole of the optical disc D by driving the mask cap attaching / detaching means 29.

Then, as shown in FIG. 5 (d), the blade 51 moves the coating liquid 49 dropped on the mask plate 25 by the coating liquid supply means 41 from the right to the left in the figure by the moving means 53. Then, as shown in FIG. 5 (e), the blade 51 passes through the coating surface 57 of the optical disk D together with the coating liquid 49, and a coating liquid layer 65 having a predetermined thickness is formed on the coating surface 57 of the optical disk D.
The film thickness T of the coating liquid layer 65 applied to the optical disk D is a vertical distance between the lower surface 59 of the blade 51 and the coating surface 57 of the optical disk D, in other words, when the thickness t of the mask plate 25 is constant. It is determined by the gap G between the lower surface 59 of the blade 51 and the mask plate 25.

  Next, as shown in FIG. 5 (f), the mask cap attaching / detaching means 29 is driven, and the mask cap 37 is detached from the optical disk D. As a result, a circular step 69 to which the coating liquid 49 is not applied is formed at the center of the optical disc D. Next, when the air cylinder 23 is driven, the optical disk D is separated downward from the opening peripheral edge 25a of the mask plate 25 as the suction table 13 is lowered as shown in FIG.

As a result, the coating liquid 49 applied to the coating surface 57 is separated from the coating liquid 49 on the mask plate 25 by shearing. As a result, since the outer peripheral edge of the optical disk D is covered with the mask plate 25, the non-application part 71 shown in FIG. 6 where the application liquid 49 is not applied is formed.
Note that the shape of the application part can be freely set by appropriately changing the opening shape of the mask plate 25.

  The optical disk D in which the application of the coating liquid 49 has been completed in this manner is omitted from the drawing table 13 and is transferred to the drying process of the coating liquid 49 in the next process, although not shown.

  In this embodiment, the blade coating apparatus is used for coating the printing surface of the optical disk. However, the object is not limited to this, and any object that forms a thick film may be coated. Can do.

In the blade coating apparatus 100 described above, the blade 51 is formed of a stainless material. However, the present invention is not limited to this, and may be a resin material or hard rubber, for example.
FIG. 7 shows a blade coating apparatus 200 including a blade 81 made of hard rubber, which is an elastic material. The blade 81 is in elastic contact with the mask plate 25 and is horizontally driven by the moving means 53 to move from the right to the left in the figure while sliding on the mask plate 25 to apply to the coating surface 57 of the optical disc D. Liquid 49 is applied.
Since the other parts are the same as those of the blade coating apparatus 100 described above, the same parts are denoted by the same reference numerals or the corresponding reference numerals, and the description thereof is simplified or omitted.

  According to this blade coating apparatus 200, the blade 81 moves horizontally while being in sliding contact with the mask plate 25, so that the coating liquid 49 on the mask plate 25 is scraped by the blade 81 and is not applied onto the mask plate 25. Therefore, the amount of the coating liquid 49 that is wasted can be minimized, and the coating liquid 49 can be used effectively.

FIG. 8 shows another blade coating apparatus 300 that can reuse the coating liquid 49 and effectively use it without waste.
In the blade coating device 300, a coating solution supply unit 41 is provided above the mask plate 25 outside the opening 27. The coating liquid supply means 41 includes a coating liquid supply nozzle 43, a coating liquid supply device 45, a coating liquid tank 83, and a supplementary coating liquid tank 85. The coating liquid tank 83 is connected to the coating liquid supply device 45 and the replenishment coating liquid tank 85 via a supply path 87 such as a pipe. The coating solution supply device 45 supplies the coating solution 49 supplied from the coating solution tank 83 dropwise onto the mask plate 25 from the coating solution supply nozzle 43. When the remaining amount of the coating liquid 49 in the coating liquid tank 83 decreases, the coating liquid 49 is replenished from the replenishing coating liquid tank 85 to the coating liquid tank 83.

  The blade coating apparatus 300 further includes a coating liquid collecting unit 95. The coating liquid recovery means 95 includes a coating liquid recovery opening 89 provided in the mask plate 25, a coating liquid recovery part 91 disposed below the opening 89, and a coating liquid reforming part 93. The coating solution recovery unit 91, the coating solution reforming unit 93, and the coating solution tank 83 are connected via a supply path 97 such as a pipe.

The opening 89 is a rectangular hole formed in the mask plate 25 on the operation end side of the blade 51, for example, having a long side longer than the length of the blade 51 (length in the direction perpendicular to the paper surface in the drawing). The coating liquid recovery unit 91 is a container that receives and recovers the coating liquid 49 dripped from the opening 89, and the coating liquid modification unit 93 filters the coating liquid 49 recovered by the coating liquid recovery unit 91 to apply the coating liquid Impurities mixed in 49 are removed, and if necessary, a deficient component is added to modify the same so as to have the same quality as the new coating liquid 49, and then supplied to the coating liquid tank 83.
Since the other parts are the same as those of the blade coating apparatus 100 described above, the same parts are denoted by the same reference numerals or the corresponding reference numerals, and the description thereof is simplified or omitted.

The blade 51 applies the application liquid 49 to the application surface 57 of the optical disc D exposed by the opening 27 of the mask plate 25 by horizontally moving on the mask plate 25 from the right to the left in the drawing. When the blade 51 reaches the position of the opening 89 formed in the mask plate 25, the coating liquid 49 remaining without being applied is dropped from the opening 89 and collected by the coating liquid collection unit 91. The recovered coating liquid 49 is reformed by the coating liquid reforming unit 93 and returned to the coating liquid tank 83, and is again dropped from the coating liquid supply nozzle 43 onto the mask plate 25 and reused.
Thus, since the coating liquid 49 remaining without being applied is circulated and reused, there is no useless coating liquid 49 and all the coating liquids 49 are used effectively.

Next, an example in which a coating solution is applied to an optical disk by a blade coating apparatus having the same configuration as that of the above embodiment and a comparative example will be described.
In both the example and the comparative example, the coating liquid was applied to the surface of the optical disk while variously changing the thickness t of the mask plate and the gap G between the lower surface of the blade and the mask plate shown in FIG. As the coating solution, a coating solution made of a material shown in Table 1 for forming a receiving layer on an optical disk was used. The liquid viscosity of the coating liquid was 500 cP as a result of measurement with a B-type viscometer (bismetholone) at 25 ° C.

  Table 2 shows the evaluation results under each coating condition.

As shown in Table 2, when the gap G between the lower surface of the blade and the mask plate is 150 μm or more, dripping occurs in the coating liquid layer, and when it is 20 μm or less, streaks occur in the coating liquid layer and the coating has good surface properties A liquid layer was not obtained. On the other hand, when the gap G between the lower surface of the blade and the mask plate was 20 μm to 150 μm, it was confirmed that coating with good surface properties was possible.
Therefore, the effectiveness of the present invention was demonstrated.

  Note that the blade coating apparatus according to the present invention is not limited to the above-described embodiments, and can be appropriately modified and improved.

It is a block diagram showing schematic structure of the coating device which concerns on this invention. It is the perspective view showing the outline of the external appearance of the coating device shown in FIG. It is a principal part side view of the coating device shown in FIG. It is explanatory drawing which represented the basic procedure of the coating method which concerns on this invention by (a)-(c). It is explanatory drawing which represented the basic procedure of the coating method which concerns on this invention by (d)-(g). It is a top view of the to-be-coated member which application was completed. It is a principal part side view of the coating device of other embodiment provided with the braid | blade of the hard rubber. It is a principal part side view of the coating device of further another embodiment provided with the coating liquid collection | recovery means. A state in which a coating liquid is applied by a conventional disk coating apparatus is shown, (a) is a perspective view showing a state in which the coating liquid is applied to the optical disk by a blade, and (b) is a perspective view showing a state in which the optical disk is separated from the mask plate. FIG.

Explanation of symbols

100 Blade coating device 25 Mask plate (mask)
27 Opening 49 Coating liquid 51 Blade 59 Lower surface of blade 65 Coating liquid layer D Optical disc (disc-shaped recording medium, flat substrate)
G Gap between the lower surface of the blade and the mask plate T Thickness of the coating liquid layer

Claims (2)

A mask having an opening is superposed on a flat substrate, a coating liquid is supplied onto the mask, and the coating liquid is coated on the mask by a blade that moves relative to the mask above the mask, and then the mask. And a blade coating method of forming a coating liquid layer corresponding to the opening of the mask on the planar substrate,
A blade coating method, wherein a gap between the mask and the lower surface of the blade is 20 μm to 150 μm.   A disk coating method comprising forming at least one layer of a printing surface of a disk-shaped recording medium by the blade coating method according to claim 1.

Images