JP4830754B2 - Coating apparatus and coating film forming method - Google Patents

Description

  The present invention relates to an extrusion (extrusion) type coating apparatus, and dissolves or disperses a functional substance that exhibits a function in a flexible support such as a plastic film, paper, or metal foil in a solvent by a die coating method. The present invention relates to a coating apparatus for producing a sheet molded product that exhibits high functionality by coating the applied coating liquid.

  There are two types of processes for producing sheet-like products that exhibit high functionality: dry processes such as vapor deposition and wet processes such as coating. In recent years, the so-called “pre-weighing type” coating method using a die head has been used in the wet process. In the coating process using a die head, after the coating liquid is introduced into the die head, it is once spread in the width direction at a place called a manifold, and is applied uniformly in the width direction by passing through a narrow gap called a slit. . In order to prevent the coating liquid passed through the die head from being applied with a certain desired width and not to reach an undesired width, it is common to use what is called a width regulating plate. An example of use of the width regulating plate is described in Patent Document 1.

  If you continue to produce the same product, you only need to use one type of width restriction plate, there is no need to change the installation state, and there is an option of having a structure with no width restriction plate by providing a step on the die head mating surface . In Patent Document 2, it is proposed to change the coating width by shifting the width regulating plate in order to deal with various products with one die head. However, in this case, even though the coating width can be changed, the slit gap cannot be changed by changing the width regulating plate.

Patent Document 3 also proposes a method of changing the gap between the slits. However, in this case, even if the slit gap can be changed, it is difficult to change the coating width.

  Therefore, in order to change both the slit gap and the coating width, not the method of forming a step to form the desired gap by matching the blocks of the die head, but forming the mating surface part of the block and the slit and manifold. This is achieved by inserting width regulating plates that provide desired slit gaps at three locations on both ends of the portion to be formed. This width restricting plate may be a “U-shaped” width restricting plate in which three portions are integrated, or may be a “three-part separated type” in which three portions are formed separately at each portion. In Patent Document 4, a “U-shaped” width regulating plate is described.

  In the first place, it is necessary to change the width regulating plate when the product is changed because the discharge amount distribution is uneven due to the physical properties such as the viscosity and flow rate of the coating liquid. Regarding the influence, there is a discussion as disclosed in Patent Document 5. When the type of coating liquid is changed, the value of the slit gap that affects the discharge amount distribution has an optimum value.

  On the other hand, it is also known that the accuracy in the width direction of the slit gap affects the uniform coating. For example, Patent Document 7 describes an adjustment method for maintaining the accuracy. Although the slit gap is directly adjusted, it can be said that it is a suitable method for fine adjustment. However, fine adjustment on the actual production site may cause a difference depending on a practitioner and is not suitable for stable production.

  Of course, the straightness of the block of the die head forming the slit is also important, and is described in, for example, Patent Document 7. However, in order to form the slit gap with the width regulating plate, not only the straightness of the block but also the film thickness uniformity of the width regulating plate itself is important.

Japanese Patent Laid-Open No. 3-89969 JP-A-11-179260 JP-A-9-85149 Japanese Patent Laid-Open No. 9-253555 JP 2003-10762 A JP-A-9-131561 Japanese Patent Laid-Open No. 2-207866

  In order to produce various products with a single die head, it is necessary to use a "U-shaped" or "3-part separation type" width restriction plate that can realize an optimal slit gap by changing the width restriction plate. Realistic. However, the use of these width restricting plates makes it easy for variations in the slit gap to occur, and adjustment is not possible after being sandwiched. In particular, when a “U-shaped” or “three-part separation type” width restricting plate is used, the slit gap at both ends tends to widen compared to the center of the coating width, and the film thickness in the width direction There was a problem that a non-uniform coating film was formed. Accordingly, an object of the present invention is to provide means for realizing an accurate slit gap in the width direction when using a “U-shaped” or “three-part separated type” width regulating plate.

In order to solve the above problems, it is effective for the present invention to take the following measures.

The invention according to claim 1 is used at the time of coating in an extrusion method, and a slit gap which sandwiches a width regulating plate between two blocks and serves as a discharge port for the coating liquid depending on the thickness of the width regulating plate. A coating device comprising a die head on which is formed,
The width regulating plate is composed of a block aligning portion disposed over the width direction of the die head, and end portions formed at both ends of the block aligning portion disposed at both ends of the die head,
The coating apparatus is characterized in that t ₁ , t ₂ , and t ₃ satisfy the following formulas when the thickness of the block matching portion is t ₁ and the thicknesses of both ends are t ₂ and t ₃ , respectively. .
0.93t ₁ <t ₂ <t ₁
0.93t ₁ <t ₃ <t ₁

According to a second aspect of the present invention, there is provided the coating apparatus according to the first aspect, wherein a thickness t ₁ of the block matching portion is 50 μm or more and 200 μm or less.

The invention according to claim 3 is used at the time of coating in the extrusion method, and a slit that serves as a discharge port for the coating liquid is sandwiched between the two blocks and the two blocks, and the thickness of the width regulating plate. A coating apparatus comprising a die head to be formed,
The width regulating plate has a block alignment plate arranged over the width direction of the die head, and end plates arranged at both ends of the die head,
The coating apparatus is characterized in that t ₄ , t ₅ , and t ₆ satisfy the following formulas, where the thickness of the block matching plate is t ₄ and the thicknesses of both end plates are t ₅ and t ₆ , respectively. .
0.93t ₄ <t ₅ <t ₄
0.93t ₄ <t ₆ <t ₄

According to a fourth aspect of the present invention, there is provided the coating apparatus according to the third aspect, wherein the thickness t ₄ of the block alignment plate is 50 μm or more and 200 μm or less.

According to a fifth aspect of the present invention, a coating liquid is applied to a flexible support using the coating apparatus according to any one of the first to fourth aspects, and a coating film is formed on the support. It is set as the formation method of the coating film characterized.

  In claim 1, by setting the thickness of the block-matching portion of the "U-shaped" width regulating plate and the thickness of both ends of the die head, the slit gap variation that occurs when the width regulating plate is used, In particular, compared to the center of the coating width, the slit gaps at both ends are not widened, and it becomes possible to form a coating film with a high precision with a uniform film thickness distribution in the coating width direction.

  Further, in claim 3, by setting the thicknesses of the block aligning plate and both end plates of the “three-part separated type” width restricting plate, similarly to claim 1, it is generated by using the width restricting plate. The slit gap variation, especially the slit gap at both ends compared to the center of the coating width, is no longer spread, the film thickness distribution in the coating width direction is constant, and it is possible to form a highly accurate coating film became.

  A first aspect of a die head using a “U-shaped” width regulating plate in the coating apparatus of the present invention will be described. FIG. 1 shows a perspective view of a first embodiment of a die head in the coating apparatus of the present invention. In FIG. 1, the die head 10 has a structure in which a width regulating plate X is sandwiched between two blocks 11 and 12 and both blocks. Further, the die head 10 has a manifold portion 13 that becomes a liquid pool in one or both of the blocks. The width restricting plate is composed of a block aligning portion disposed over the width direction of the die head and an end portion for restricting the coating width disposed at both ends of the die head, and these are integrated, and the “U-shaped” width restricting plate and It has become.

  Both blocks 11 and 12 are fixed by a block fastening bolt (not shown) in a form sandwiching a width regulating plate. There are no restrictions on the number or position of the bolt holes 14 for fastening with the fastening bolts, but usually, the block is usually below the midpoint of the length in the height direction when the block is erected so that the slit tip faces upward. A bolt hole for a fastening bolt is opened in the portion, and the width restricting plate is also sandwiched.

  FIG. 2 shows a sectional view of the die head when the two blocks and the width regulating plate in the coating apparatus of the present invention are fixed. A width regulating plate X is tightly sandwiched between the two blocks 11 and 12. As shown in FIG. 2, the slit gap d varies depending on the thickness of the width regulating plate. In the present invention, by defining the thickness of the block matching portion and the end of the width regulating plate, the slit gap d formed by the width regulating plate can be a uniform die head in the width direction of the die head. A coating film having a uniform film thickness in the direction can be obtained.

FIG. 3 shows a plan view of a “U-shaped” width regulating plate in the coating apparatus of the present invention. As shown in FIG. 1, the “U-shaped” width restricting plate is divided into three parts: a block aligning portion X1 arranged over the width direction of the head and end portions X2 and X3 formed at both ends of the block aligning portion. It is done. In the present invention, the thicknesses of the block alignment portion X1 and the end portions X2 and X3 are respectively defined. The present invention is characterized in that the thicknesses t ₂ and t ₃ of the end portions X2 and X3 of the width regulating plate are made smaller than the thickness t ₁ of the block mating portion X1, and further, the thickness t _{2 of the} end portion. , T ₃ is larger than 0.93 t ₁ . That is, the “U-shaped” width regulating plate of the present invention is characterized in that t ₁ , t ₂ , and t ₃ satisfy the following expressions.
0.93t ₁ <t ₂ <t ₁
0.93t ₁ <t ₃ <t ₁

By making the thicknesses t ₂ and t ₃ of the end portions smaller than the thickness t ₁ of the matching portions of the blocks, the tendency that the slit width near the center of the slit becomes larger than the width of the slit end portion can be prevented. When t ₂ and t ₃ are 0.93 t ₁ or less, the width regulating plate becomes too thin with respect to the slit width, and the liquid in the manifold oozes out.

Further, in the present invention, the thickness t ₁ of the block matching portion is as follows when the desired slit gap of the die head when the both blocks and the width regulating plate as shown in FIG. It is preferable to satisfy the formula.
d <t ₁ <1.05d

  A desired slit width d is set in the width direction by using a width regulating plate having a block matching portion having a thickness larger than the desired slit gap d and an end portion having a thickness smaller than the block matching portion. The die head can be uniformly provided.

Particularly in the coating apparatus of the present invention, a great effect can be obtained when the thickness t ₁ of the block matching portion of the width control plate is 50 μm or more and 200 μm. When it is necessary to form a very thin coating film with a wet film thickness of 15 μm on the support, a very narrow slit gap with a slit width of 50 μm to 200 μm is formed, depending on the coating speed. There is a need to. In the case of coating using a die head having such a narrow slit gap, it has a great influence on the film thickness distribution of the coating film from which the uniformity of the slit gap in the width direction is obtained. It can be suitably used.

  Next, a method for measuring the thickness of the width restriction plate of the die head in the coating apparatus of the present invention will be described. The width regulating plate used in the manufacturing machine has a size exceeding 1 m in the width direction, and it is unrealistic to measure the thickness of the entire width regulating plate. FIG. 4 shows an explanatory view of the width regulating plate in the coating apparatus of the present invention. As shown in FIG. 4, the thickness of the block alignment portion X1 of the width regulating plate is divided into 5 in the die head width direction and 2 in the vertical direction, and the block alignment portion is divided into 10 regions. The thickness can be measured, and the average value of the thickness of each region can be used as the thickness of the block matching portion. Regarding the thickness of each region, it is preferable to measure the center of the region, but if the center cannot be measured by a bolt hole or the like, it may be near the center.

  As shown in FIG. 4, the widths X2 and X3 are divided into two parts in the width direction of the die head and five parts in the vertical direction, as shown in FIG. The average value of the thickness can be the thickness of the width portion.

In the width regulating plate of the present invention, when the maximum value among the thicknesses measured in each region is t _max , the minimum value is t _min , and the average thickness of each region is t _av ( It is preferable that the film thickness distribution (%) obtained by t _max −t _min ) / t _av × 100 is 5% or less.

  For example, a contact-type film thickness meter manufactured by Mitutoyo can be used as the film thickness measuring device, but either a contact-type film thickness meter or a non-contact-type film thickness meter may be used, and the thickness value depends on the measuring device. do not do.

  A second aspect of the die head using the “three-part separation type” width regulating plate in the coating apparatus of the present invention will be described. FIG. 5 shows a perspective view of a second embodiment of the die head in the coating apparatus of the present invention. In FIG. 5, the die head 10 has a structure in which a width regulating plate Y is sandwiched between two blocks 11 and 12 and both blocks. The die head 10 has a manifold portion 6 that serves as a liquid pool in one or both of the blocks. The width regulating plate is composed of a block aligning plate Y1 arranged over the width direction of the die head and end plates Y2 and Y3 arranged at both ends of the die head to regulate the coating width, and these are formed independently. This is a “part separation type” width regulating plate Y.

  Both blocks are fixed by a block fastening bolt (not shown) with a width regulating plate interposed therebetween. There are no restrictions on the number or position of the bolt holes 14 for fastening with the fastening bolts, but usually, the block is usually below the midpoint of the length in the height direction when the block is erected so that the slit tip faces upward. A bolt hole for a fastening bolt is opened in the portion, and the width restricting plate is also sandwiched.

  The “3-part separation type” width restriction plate is installed in the same place as the “U-shaped” width restriction plate, but the end plates Y2 and Y3 sandwiched between the manifold and the part where the slit is formed are shifted during production. Sometimes. In order to prevent displacement of the end plates Y2 and Y3, the end plate can be fixed to the block with a small pin or a small bolt.

FIG. 6 shows a plan view of a “three-part separation type” width regulating plate in the coating apparatus of the present invention. As shown in FIG. 5, the “three-part separation type” width regulating plate Y has three parts: a block aligning plate Y1 arranged over the width direction of the head and end plates Y2 and Y3 arranged at both ends of the die head. Formed. In the present invention, the thicknesses of the block alignment plate and the end plate are respectively defined. In the present invention, the thicknesses t ₅ and t ₆ of the end plates Y2 and Y3 of the width regulating plate are made smaller than the thickness t ₄ of the block alignment plate Y1, and the end plates Y2 and Y3 are further characterized. the thickness _t 5, _{t 6} of, characterized by a value smaller than the large _{t 4} than 0.93t _4. That is, the “three-part separation type” width regulating plate of the present invention is characterized in that t ₄ , t ₅ , and t ₆ satisfy the following expressions.
0.93t ₄ <t ₅ <t ₄
0.93t ₄ <t ₆ <t ₄

By making the thicknesses t ₂ and t ₃ of the end plates Y2 and Y3 smaller than the thickness t _{4 of the} laminated plate Y1 of the block, the slit width near the center of the slit is prevented from becoming larger than the width of the slit end portion. However, when t ₅ and t ₆ are 0.93 t ₄ or less, the width regulating plate becomes too thin with respect to the slit width, so that the liquid in the manifold oozes out.

In the present invention, the thickness t4 of the block aligning plate preferably satisfies the following equation, where d is the desired slit gap of the die head when both blocks and the width regulating plate are fixed.
d <t ₄ <1.05d

  A desired slit width d is set in the width direction by using a width regulating plate having a block matching portion having a thickness larger than the desired slit gap d and an end portion having a thickness smaller than the block matching portion. The die head can be uniformly provided.

Especially In the coating apparatus of the present invention can be achieved a great effect when the thickness t ₄ of the block combined plate Y1 width control plate was at 200μm or 50 [mu] m. When it is necessary to form a very thin coating film with a wet film thickness of 15 μm or less on the support, it is necessary to form a very narrow slit gap with a slit width of 50 μm to 200 μm, depending on the coating speed. is there. In the case of coating using a die head having such a narrow slit gap, it has a great influence on the film thickness distribution of the coating film from which the uniformity of the slit gap in the width direction is obtained. It can be suitably used.

  In the second embodiment, the thickness of the width regulating plate is obtained by dividing the block alignment plate and the end plate by 5 × 2 = 10 and measuring the film thickness at the center of each region, as in the first embodiment. It is done.

  Since the width regulating plate in the coating apparatus of the present invention determines the coating width, the positional relationship is set based on the coating width. The material is generally metal, among which SUS is generally used, but other metals such as aluminum and iron, super hard materials such as tungsten carbide, and alloys can also be used. Use of a resin such as polyethylene terephthalate, Teflon (registered trademark), or vinyl chloride does not hinder the effects of the present invention. The width regulating plate can be manufactured by punching from a large metal plate or by cutting it with a wire cut. The effects of the present invention are not affected by the manufacturing method. Also, means such as polishing can be used to adjust the thickness of each part of the width regulating plate.

  Next, the coating apparatus of the present invention will be described. FIG. 7 shows a schematic diagram of the coating apparatus of the present invention. The coating apparatus of the present invention has a structure in which the die head 10 is connected to the coating liquid tank 32 by a pipe 31 and the coating liquid in the coating liquid tank 32 is fed into the die head 10 by a liquid feeding pump 33. The coating liquid fed to the die head 10 discharges the coating liquid from the slit gap, and a coating film is formed on a flexible support 34 such as a plastic film, paper, or metal foil. By using the roll roller 35 using the roll-up support 34, a coating film can be continuously formed on the support by a roll-to-roll method.

  A 50 wt% acrylic UV curable resin using a roll-up polyethylene terephthalate (PET) substrate having a width of 650 mm and using an extrusion type die head having a width of 640 mm as a diluent solvent of methyl ethyl ketone (MEK) and methyl acetate. A coating solution was prepared and applied at a speed of 50 m / min. At this time, a "U-shaped" width regulating plate was incorporated in the die head, and the blocks having different thicknesses t1 and widths t2, t3 were manufactured, and each was attached to the die head for coating. . In Example 1 and Comparative Examples 1 to 3, the wet film thickness was 10 μm, and in Example 2 and Comparative Examples 4 to 6, the wet film thickness was 20 μm. The viscosity of the coating solution is 4 mPas and the surface tension is 25 mN / m.

The results of measuring the film thickness distribution of the coating film formed on the PET substrate after coating with a contact-type film thickness meter were compared. The film thickness distribution is represented by the following equation when the maximum film thickness in the width direction of the coated film after application is T _max , the minimum film thickness is T _min , and the average film thickness is T _av .
Film thickness distribution (%) of coating film = (T _max −T _min ) / T _av × 100

  Below, the result of the film thickness distribution of the obtained coating film of Examples 1, 2 and Comparative Examples 1-6 is shown. Further, among the film thickness distributions, those smaller than 3% are marked as “good”, and those with 3% or more are marked as “bad”.

  In Example 1 which is an embodiment of the present invention in Example 1 and Comparative Examples 1 to 3, the film thickness distribution of the coating film obtained in comparison with Comparative Examples 1 to 3 shows a good value, and in the width direction It was confirmed that a uniform coating film was obtained.

In Example 2 and Comparative Examples 4 to 6, in Example 2, which is an embodiment of the present invention, the film thickness distribution of the coating film shows a better value than in Comparative Examples 4 to 6, and the coating is uniform in the width direction. It was confirmed that a film was obtained. However, in the case of Example 2 where t ₁ is 200 μm or more, since the film thickness uniformity is improved as a whole, the effect of the present invention is small compared to the case of Example 1 and Comparative Examples 1 to 3. .

The present invention relates to a coating method, and in particular, a sheet-like material that exhibits high functionality by applying a dispersion that exhibits a function to a flexible support such as a plastic film, paper, or metal foil. It can be used suitably when manufacturing a product, and in particular, it can be suitably used when forming a coating film made of a thin film on which a film thickness distribution in the width direction is difficult to control on a support.

FIG. 1 is a perspective view of a first embodiment of a die head in the coating apparatus of the present invention. FIG. 2 is a cross-sectional view of the die head when two blocks and a width regulating plate are fixed in the coating apparatus of the present invention. FIG. 3 is a plan view of a “U-shaped” width regulating plate in the coating apparatus of the present invention. FIG. 4 is an explanatory view of a width regulating plate in the coating apparatus of the present invention. FIG. 5 is a perspective view of a second embodiment of the die head in the coating apparatus of the present invention. FIG. 6 is a plan view of a “three-part separation type” width regulating plate in the coating apparatus of the present invention. FIG. 7 is a schematic view of the coating apparatus of the present invention.

Explanation of symbols

10 Die head 11 Block 12 Block 13 Manifold part 14 Bolt hole d Slit gap X Width regulating plate ("U-shaped")
X1 Width regulating plate ("U-shaped") Block alignment part X2 Width regulating plate ("U-shaped") End X3 Width regulating plate ("U-shaped") End Y Width regulating plate ("3 Site separation type ")
Y1 Width regulating plate ("3-part separation type") Block alignment plate Y2 Width-regulating plate ("3-part separation type") End plate Y3 Width regulation plate ("3-part separation type") End plate 31 Pipe 32 Coating liquid tank 33 Liquid feed pump 34 Support 35 Rotating roll

Claims (5)

Used in extrusion coating, a coating provided with a die head in which a width regulating plate is sandwiched between two blocks, and a slit gap is formed as a coating liquid discharge port depending on the thickness of the width regulating plate A device,
The width regulating plate is composed of a block aligning portion disposed over the width direction of the die head, and end portions formed at both ends of the block aligning portion disposed at both ends of the die head,
An applicator characterized in that t ₁ , t ₂ , and t ₃ satisfy the following equations, where t _{1 is} the thickness of the block matching portion, and t ₂ and t ₃ are the thicknesses of both ends.
0.93t ₁ <t ₂ <t ₁
0.93t ₁ <t ₃ <t ₁ The coating apparatus according to claim 1, wherein a thickness t ₁ of the block matching portion is 50 μm or more and 200 μm or less. A coating apparatus having a die head that is used when coating in an extrusion method, sandwiching a width regulating plate between two blocks and forming a slit serving as a coating liquid discharge port depending on the thickness of the width regulating plate Because
The width regulating plate has a block alignment plate arranged over the width direction of the die head, and end plates arranged at both ends of the die head,
An applicator characterized in that t ₄ , t ₅ , and t ₆ satisfy the following equations, where t _{4 is} the thickness of the block alignment plate, and t ₅ and t ₆ are the thicknesses of both end plates.
0.93t ₄ <t ₅ <t ₄
0.93t ₄ <t ₆ <t ₄ The coating apparatus according to claim 3, wherein a thickness t ₄ of the block alignment plate is 50 μm or more and 200 μm or less.   A coating film forming method, wherein a coating liquid is applied to a flexible support using the coating apparatus according to claim 1, and a coating film is formed on the support. .