JP2004321915A - Coating method and coater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a thin coating layer by precisely controlling a film thickness. <P>SOLUTION: Tapped holes (as indicated by points P4, P5, and P6) for push bolts and/or pull bolts are formed in a coater body 10a. The coater body 10a is curved in a manner that its outside approaches to a web 12. The push bolt is used as the point 4 to allow a front lip 15a to approach to the web 12. Pull bolts are used as the points P5 and P6 on the outside of the curved coater body 10a so as to separate the front lip 15a from the web 12. By adjusting a clearance between the web 12 and the front lip 15a, a wet film becomes substantially uniform along the direction of coating width and the fluctuation in the wet film thickness of the coating layer can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４４】
表１より、本発明に係る塗布装置（コーター）を用いると、切削温度と異なる塗布液を送液してもクリアランスのばらつきＷを抑制できることが分かる。さらに、スロットダイの側面側と中心側とに押し型ボルト及び／または引き型ボルトを取り付けて調整を行った実施例１及び実施例２の実験では、ばらつきＷを抑制する効果が顕著に見られることが分かった。
【００４５】
［光学補償シートの作製及び評価］
ウェブ１２には、厚み１００μｍのセルローストリアセテート基材（商品名；フジタック、富士写真フイルム（株）製）を用い、塗布液を塗布する前に長鎖アルキル変性ポリビニルアルコール（商品名；ポバールＭＰ−２０３、クラレ（株）製）の２重量％溶液を２５ｍｌ／ｍ^２ で塗布し、６０℃で１分間乾燥して配向膜用樹脂層を形成した。配向膜用樹脂層をあらかじめ形成したウェブ１２を送り、配向膜用樹脂層の表面にラビング処理を施して配向膜を形成し、そのまま塗布工程へ搬送して塗布を実施した。なお、ラビング処理におけるラビングローラの回転周速を５．０ｍ／秒とし、ウェブ１２に対する押しつけ圧力を９．８×１０^−３Ｐａに設定した。
【００４６】
塗布液１４には、化１に示すディスコティック化合物ＴＥ−（１）とＴＥ−（２）の重量比率４：１の混合物に、光重合開始剤（商品名；イルガキュア９０７、日本チバガイギー（株）製）を１重量％添加した４０重量％メチルエチルケトン溶液である、液晶性化合物を含む溶液を用い、塗布層の厚み（湿潤膜厚）Ｔが５μｍとなるように、実施例１の条件のコーターを用いて５０ｍ／分で搬送させたウェブ１２に対して塗布した。なお、塗布液１４の温度は２３℃であった。減圧度は１６００Ｐａに設定し、デジタルマノメーターでその変動幅を測定した。塗布液１４を塗布したウェブ１２を、１００℃に設定した乾燥ゾーン、及び１３０℃に設定した加熱ゾーンを通過させ、その表面の液晶層に紫外線ランプ（１６０Ｗ空冷メタルハライドランプ、アイグラフィックス（株）製）を用いて紫外線を照射した。巻き取ったあと塗布層１４ｂを目視検査した。この結果、塗布層１４ｂに段状ムラ等は全く認められず、塗布層の面状態は非常に良好であった。このように、本発明の塗布方法によれば、湿潤膜厚が５μｍの塗布層を良好に形成することが可能であることが分かった。
【００４７】
【化１】

【００４８】
【発明の効果】
以上のように、本発明塗布方法及び塗布装置によれば、ブロック切削温度と塗布液の温度とが異なる場合であっても、塗布層の厚みが薄いものを連続的かつ高精度に形成できる。
【図面の簡単な説明】
【図１】本発明に係る塗布装置を説明するための要部断面図である。
【図２】図１に示した塗布装置の斜視図である。
【図３】本発明に係る塗布装置のクリアランス調整に用いられる部材の一実施形態を説明するための図である。
【図４】本発明に係る塗布装置のクリアランス調整に用いられる部材の他の実施形態を説明するための図である。
【図５】本発明に係る塗布装置のクリアランス調整の一実施形態を説明するための要部平面図である。
【図６】本発明に係る塗布装置のクリアランス調整の他の実施形態を説明するための要部平面図である。
【図７】本発明に係る塗布装置のクリアランス調整の他の実施形態を説明するための要部平面図である。
【図８】本発明に係る塗布装置のクリアランス調整の他の実施形態を説明するための要部平面図である。
【図９】図１に示す塗布装置の要部平面図である。
【図１０】本発明に係る塗布装置の他の実施形態の要部背面図である。
【図１１】本発明に係る塗布装置の他の実施形態の要部背面図である。
【図１２】本発明に係る塗布装置の他の実施形態の要部背面図である。
【図１３】本発明に係る塗布装置を用いた実施例を説明するための要部平面図である。
【符号の説明】
１０ コーター
１０ａ コーター本体
１２ ウェブ
１５ａ 下流側先端リップ
２０ａ 上流側ブロックねじ孔
３２ 架台
３２ａ 架台ねじ孔
４０ 引き型ボルト
４１，４３ ロックナット
４２ 押し型ボルト[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating method and a coating apparatus using a die, and in particular, a photographic photosensitive emulsifier, a magnetic liquid, a liquid that imparts antireflection and antiglare properties, a liquid that imparts a viewing angle widening effect, and a pigment for a color filter. A coating method for producing a highly functional laminated film by coating a coating liquid such as a liquid or a surface protection liquid on a flexible support (hereinafter referred to as a web) such as a plastic film, paper, or metal foil; The present invention relates to a coating apparatus.
[0002]
[Prior art]
The high-functional laminated film is manufactured by applying and laminating a coating solution on a web using a coater (coating device) using a slot die. In recent years, in the production of a highly functional laminated film, there is an increasing demand for a high-precision film thickness control coating technique for each layer constituting the laminated film in order to express a desired function. In performing the coating, the clearance between the slot die coating liquid discharge section (hereinafter referred to as the tip lip) and the web may be uneven due to various disturbances, for example, distortion such as bending due to the temperature change of the slot die. . In this case, a non-uniform coating film thickness phenomenon occurs, and this phenomenon generally tends to become a serious problem as the required film thickness accuracy becomes severe.
[0003]
In particular, in the thin layer coating having a wet film thickness of 25 μm or less, the required accuracy of the film thickness is increased, so that the deformation of the block constituting the slot die can be suppressed and the clearance accuracy between the tip lip and the web can be maintained. I need it. For example, by matching the cutting temperature and the coating liquid temperature when the block is formed, the curvature of the slot die is reduced and the accuracy is easily maintained. Also, if the cutting temperature and the coating liquid temperature are different, the tip lip and web being applied are started by applying the liquid at the same temperature as the coating liquid to the block in advance to settle the deformation of the block. Variation in clearance due to changes with time can be suppressed. However, when the original cutting temperature and the coating liquid temperature are different, the curvature of the block itself cannot be suppressed. Therefore, even if the deformation (curvature) is settled, the clearance varies in the application width direction. In view of this, an apparatus has been proposed in which the block has a curved structure in advance in accordance with the deformation of the backup roller during application of tension (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-328600 (Page 2, Fig. 1)
[0005]
[Problems to be solved by the invention]
However, since the apparatus is only a pressing force mechanism for the block, it may be difficult to perform fine adjustment. Further, it can cope only with a gentle deformation in the coating width direction with respect to deformation such as bending. For this reason, when the block side is deformed due to the influence of temperature or the like, there is a problem that a clearance that satisfies the required accuracy of the film thickness cannot be maintained. In addition, the pressing force mechanism only considers the response to uniform deformation with a long pitch such as deformation of the backup roller when tension is applied, and does not assume that the block itself is curved.
[0006]
The present invention has been made in view of the above problems, and is a case where continuous coating on a web, particularly when the temperature of the coating solution at which the block of the slot die tends to deform differs from the cutting temperature of the block. However, it is an object of the present invention to provide a coating method and a coating apparatus capable of forming a highly accurate coating layer, particularly a thin layer.
[0007]
[Means for Solving the Problems]
The coating method of the present invention is a coating method in which a coating liquid is applied to a web from a tip lip of a die supported by a gantry, and a gantry support facing the die back surface on the opposite side of the tip lip. A screw member is provided between the front end lip and the web by controlling the clearance between the tip lip and the web by separating or approaching the die back surface portion and the gantry support portion. The screw member is a pull-type screw member that is screwed into a die side screw hole provided in the die back surface portion to bring the die back surface portion and the gantry support portion close to each other, or a gantry side screw hole provided in the gantry support portion. It is preferable to act as one of push-type screw members that are screwed together to separate the die back surface portion and the gantry support portion. The die side screw hole to which the screw member is attached and the gantry side screw hole are formed at a position where both face each other, and the gantry side screw hole is formed to be larger than the die side screw hole, and the die side screw When the pull-type screw member is attached to the hole, the base-side screw hole acts as a through hole, and when the push-type screw member is attached to the base-side screw hole, the tip of the push-type screw member is the die-side screw hole. It is preferable to abut on the peripheral part.
[0008]
The tightening of the pull-type screw member can make the die move away from the web as it is tightened, and the push-type screw member can deform the die closer to the web when tightened. it can.
[0009]
It is preferable that a plurality of the screw members are provided in the width direction of the web. It is preferable that a plurality of the screw members are provided at a rate of 5 cm or more and 100 cm or less along the coating width direction. The screw member is preferably provided within 100 mm from the end of the die. It is preferable to adjust the variation of the clearance within 10 μm along the coating width direction of the die.
[0010]
By providing a plurality of screw members in the width direction of the web, the clearance can be adjusted by adjusting the clearance by making the screw member a pulling die and / or a pushing die due to the difference in coating conditions and the bending condition of the die. It becomes possible to suppress variation in the direction clearance. In this case, it is more preferable to adjust the clearance after the deformation due to the temperature change of the die is settled. For example, as the method, a method in which a liquid having the same temperature as the coating liquid for 2 hours or more is allowed to flow through the die.
[0011]
The larger the number of the screw members, the more preferable because it can cope with various deformations of the die. Even in the case of gentle deformation, it is more preferable that the gap between the screw members does not exceed 100 cm. Furthermore, it is most preferable to provide the screw members at equal intervals. Since the die always has a warped shape, the outermost screw member is preferably installed on the side surface of the die as much as possible, and most preferably at least 10 cm from the side surface of the die. However, if too many screw members are provided, the straightness of the die and the pedestal is affected, so the interval between the screw members is preferably at least 5 cm.
[0012]
The coating method of the present invention is particularly effective when carried out under the following conditions 1) to 3).
1) The average clearance between the web and the tip lip is in the range of 30 μm to 100 μm.
2) At least the tip lip is made of a super hard material.
3) Application | coating whose wet film thickness of the coating layer formed from the said coating liquid is 25 micrometers or less.
[0013]
The coating apparatus of the present invention includes a gantry, a die that is supported by the gantry and applies a coating solution from the tip lip to the web, a die back surface opposite to the tip lip, and a gantry support facing the die back surface. And a screw member that controls clearance between the tip lip and the web by separating or approaching the die back surface portion and the gantry support portion. The screw member is a pull-type screw member that is screwed into a die side screw hole provided in the die back surface portion to bring the die back surface portion and the gantry support portion close to each other, or a gantry side screw hole provided in the gantry support portion. It is preferable to act as any one of the push-type screw members that are screwed together to separate the die back surface portion and the gantry support portion. The die-side screw hole to which the screw member is attached and the gantry-side screw hole are formed at positions where they face each other, and the gantry-side screw hole is larger than the die-side screw hole, When the pull-type screw member is attached, the pedestal-side screw hole acts as a through hole, and when the push-type screw member is attached to the pedestal-side screw hole, the tip of the push-type screw member is around the die-side screw hole. It is preferable to contact the part.
[0014]
According to the present invention, one screw hole can be used for either the push-type screw member or the pull-type screw member. However, if the screw hole is continuously used, it is used differently for the push-type screw member and the pull-type screw member, and there is a concern that the screw hole may be damaged. Therefore, when the frequency of adjustment is high, it is preferable to provide the screw hole dedicated to the push-type screw member and the screw hole dedicated to the pull-type screw member separately. In that case, a method of arranging two types of screw holes vertically and arranging them at the same position in the width direction (see FIG. 11) is also possible, and a method of arranging two types of screw holes alternately in a straight line (see FIG. 12). ) Is also possible.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a sectional view of a coater 10 using a slot die 13, and FIG. 2 is a perspective view. The coater 10 is applied to the web 12 supported by the backup roller 11 and continuously applied from the slot die 13 as a bead 14a to form a coating layer 14b on the web 12.
[0016]
The slot die 13 is assembled by a plurality of members, and the main ones are two blocks 20 and 21. The upstream side in the running direction of the web 12 is referred to as an upstream block 20, and the downstream side is referred to as a downstream block 21. The upstream block 20 and the downstream block 21 are assembled integrally by inserting and fastening bolts 22 as fastening members into the screw holes 25 and 26. A slot 23 and a pocket 24 are formed inside the slot die 13, and a width regulating plate 30 and a pocket plug 31 are attached to the slot die 13 (see FIG. 2), respectively, to regulate the coating width of the coating liquid and Prevents leakage. Further, a stand 32 is provided to fix the position of the slot die 13 and is fixed by bolts 33 to 35. In addition, although three bolts were illustrated for description, the number of bolts is not limited thereto.
[0017]
The slot 23 is a flow path of the coating liquid 14 from the pocket 24 to the web 12, has a cross-sectional shape in the width direction of the slot die 13, and the opening 23 a located on the web side generally has a width regulating plate 30. It is adjusted so that the width is approximately the same as the coating width. The angle θ formed by the tangent line in the web traveling direction of the backup roller 11 at the tip of the slot 23 is preferably 30 ° or more and 90 ° or less.
[0018]
The pocket 24 has a cross section formed by a curve and a straight line, and may be, for example, substantially circular or semicircular. Like the slot 23, the pocket 24 is a liquid storage space for the coating liquid 14 extended in the width direction of the slot die 13 with its cross-sectional shape, and the effective extension length is equal to or slightly longer than the coating width. It is common. The supply of the coating liquid 14 to the pocket 24 is preferably performed from the side surface of the slot die 13 or from the center of the surface opposite to the slot opening 23a.
[0019]
The slot die 13 is formed in a tapered shape over leading end lips 15a and 15b where the opening 23a of the slot is located, and the leading end is a flat portion called a land. A decompression chamber (not shown) is provided below the tip lip 15b. The decompression chamber is installed on the side opposite to the traveling direction side of the web 12 at a position where it does not come into contact so that sufficient decompression adjustment can be performed on the bead 14a. The decompression chamber includes a back plate and a side plate for maintaining its operating efficiency.
[0020]
In addition, as a means for forming the thickness (wet film thickness) T of the coating layer with high accuracy, the distance between the downstream tip lip 15a and the web 12 is shortened more accurately than the upstream tip lip 15b, thereby providing a coating layer thickness. Even when T is small, the film thickness can be easily controlled (see, for example, Japanese Patent Application No. 2002-081699). In that case, it is important to maintain the uniformity of the clearance between the tip lip and the web along the width direction of the coating width. Therefore, the coating method and the coating apparatus according to the present invention in which the clearance can be easily adjusted can be preferably applied to those having a thickness T of 25 μm or less.
[0021]
A method for adjusting the clearance between the tip lip and the web 12 will be described with reference to FIGS. 3 and 4. The adjustment of the clearance is performed by using, for example, two types of bolts 40 and 42 of M10 and M14 instead of the bolt 33. The upstream block 20 is formed with an M10 screw hole 20a, and the mount 32 is formed with an M14 screw hole 32a having a size larger than the bolt 40. The bolt 40 is screwed into the screw hole 20a, and the screw hole 32a becomes a through hole. In this case, the bolt 40 becomes a pull-type bolt, and the upstream block 20 can be drawn to the mount 32. Reference numeral 41 denotes a lock nut that adjusts the tightening amount and locks this fastening state. The lock nut 41 may be omitted. In this case, the tightening amount is adjusted using a short bolt. The other bolts 34 and 35 can also be used as pulling bolts by adopting the same form.
[0022]
Further, if M14 bolts 42 and locknuts 43 are used instead of the M10 bolts 40 and the locknuts 41, they can act as push-type bolts (see FIG. 4). Since the bolt 42 having a diameter larger than that of the screw hole 20a is used, the tip 42a of the bolt 42 abuts on the vicinity 20b of the screw hole 20a. By abutting, the bolt 42 becomes a push-type bolt that pushes the upstream block 20 to the web side. In this case, after the bolt 42 is rotated to adjust the pushing amount, the lock nut 43 is used to lock this state. In addition, the other volt | bolts 34 and 35 can also be used as a push-type volt | bolt by making it the same form.
[0023]
As described above, the fixing position of the upstream block can be adjusted by using the push-type bolt and the pull-type bolt. Note that the forms of bolts, lock nuts, formed screw holes, and the like used in the description are not limited to those described above. In the coating apparatus (coater) 10 of the present invention, it is of course possible to use a fixing bolt other than the push-type bolt and / or the pull-type bolt as a member for connecting the slot die 13 and the mount 32. After fixing the slot die 13 to the gantry 32 with a large number of fixing bolts, coating with a controlled film thickness is performed by finely adjusting the clearance using bolts arranged as push-type bolts and pull-type bolts. be able to.
[0024]
The coater body 10 a includes a slot die 13 composed of blocks 20 and 21 and a mount 32. A method of adjusting the clearance between the coater body 10a and the web 12 using a push bolt and / or a pull bolt will be described. In the drawing, the distortions of the coater body 10a and the downstream end lip 15a are exaggerated for explanation. As shown in FIG. 5, when the coater main body 10a has a convex curve with respect to the web 12, a point P1 is formed at a substantially central portion of the coater main body 10a, and a pull bolt is screwed together. The distortion of the coater body 10a and the tip lip 15a can be corrected. In the present invention, the point means a combination of the block screw hole and the mount screw hole described above.
[0025]
When the coater main body 10a is concavely curved with respect to the web 12 as shown in FIG. 6, the coater main body 10a and the like are formed by screwing the pull bolts to the points P2 and P3 on the side surface side of the coater main body 10a. Can correct distortion. Since the curvature of the side surface side of the coater main body 10a is the largest, it is preferable that the positions of P2 and P3 for screwing the pull bolt are provided as close as possible to the side surface of the coater main body 10a. Further, when correcting the distortion of the concave curve, as shown in FIG. 7, the push bolt is screwed to the point P4 at the center of the coater body 10a, and the pull bolt is attached to the points P5 and P6 on the side surface side. By screwing, distortion of the coater body 10a and the like can be corrected more strictly.
[0026]
Further, as shown in FIG. 8, when the coater main body 10a is undulated and distorted, a pulling bolt is screwed into the distorted portion where the downstream end lip 15a approaches the web 12 to move away. A push-type bolt is screwed into a place where distortion occurs. That is, in FIG. 8, by using pull-type bolts for P7, P9, P11, and P13 and using push-type bolts for P8, P10, and P12, the distortion of the coater body 10a can be corrected more strictly.
[0027]
The distortion of the coater main body 10a can be corrected by screwing the push-type bolt and / or the pull-type bolt into a point formed at an appropriate position of the coater main body 10a. As a result, as shown in FIG. 9, it is possible to reduce the variation W between the position W1 where the tip lip 15a is closest to the web 12 and the position W2 where the tip lip 15a is farthest from the web 12. The variation W is preferably 0 μm. However, if it is practically 10 μm or less, even if the thickness T of the coating layer 14 b is a thin layer of 25 μm or less, it can be applied with high accuracy. More preferably, it is 5 μm or less.
[0028]
In addition, the number of the pressing die and / or the pulling bolt used is not particularly limited. Since the screw holes (points) into which the bolts are screwed can be adapted to various deformations of the coater body 10a, the effect can be exhibited. For example, when using a coater 10 having a slot length L ′ of 1500 mm and a coating width L of 1450 mm, considering the case of gentle deformation, at least the gap between the points should not exceed 100 cm. It is useful to form. Moreover, it is preferable to make it equidistant between points. Furthermore, since the outer side of the coater body 10a is easily deformed, the outermost point is preferably formed on the outer side (that is, closer to the side surface) as much as possible, and is preferably formed at least within 10 cm from the side surface of the coater body 10a. However, increasing the number of points affects the straightness of the blocks 20 and 21 and the gantry 32, so it is preferable that there is a gap of at least 5 cm between the points.
[0029]
In the present invention, the average clearance C _ave 30μm ≦ C _ave This is particularly effective when coating is performed in the range of ≦ 100 μm. Therefore, the clearance is measured. As shown in FIG. 9, the tip lip 15a, which is one end of the clearance, fluctuates due to a variation W that is the difference between W1 from the most web and W2 that is farthest from the web. Yes. The variation W can be measured at a plurality of locations using a gap gauge, or by a measuring method described in Japanese Patent Application No. 2002-047075.
[0030]
When fixing the slot die 13 to the gantry 32, it is also effective to measure and adjust the clearance after performing the temperature adjustment found by the present inventors (see Japanese Patent Application No. 2002-047075). Deformation such as the bending of the slot die 13 is noticeable when the cutting temperature when the blocks 20 and 21 are formed by cutting and the temperature of the coating liquid are different. This is because the material (for example, SUS) of the blocks 20 and 21 expands and contracts depending on the temperature. Therefore, when the cutting temperature and the temperature of the coating liquid are different from each other, the inventors flow a liquid having the same temperature as the temperature of the coating liquid to the blocks 20 and 21 for a certain period of time so that the deformation of the blocks 20 and 21 is constant. It is also found that if the clearance between the tip lip and the web is measured and the slot die is fixedly adjusted to the frame with a push bolt and / or a pull bolt based on the result, it can be adjusted easily and with high accuracy. It was.
[0031]
It is preferable that at least the tip lips 15a and 15b are made of a super hard material. Examples of the super hard material include, but are not limited to, diamond, boron nitride (cubic), silicon carbide, boron carbide, tungsten carbide, and the like.
[0032]
A slot die used in a coater according to another embodiment of the present invention will be described with reference to FIGS. Each figure shows a rear view of the slot die. The slot die 50 shown in FIG. 10 includes a downstream block 50a and an upstream block 50b. The point 51 is formed with a bolt screw hole that can be used for either a push bolt and / or a pull bolt.
[0033]
In the slot die 55 of FIG. 11, two rows of points 57 and 58 are provided on the upstream block 55b along the coating width direction. The upper point 57 is used as a pull bolt screw hole, and the lower point 58 is used as a push bolt screw hole. The upper point 57 may be used as a push bolt screw hole, and the lower point 58 may be used as a pull bolt screw hole. Moreover, you may arrange | position in zigzag form which replaced these alternately.
[0034]
In the slot die 60 of FIG. 12, a row of points 61 and 62 are formed in the upstream block 60b along the coating width direction. These points 61 and 62 can be used alternately as a push bolt screw hole 61 and a pull bolt screw hole 62. In the present invention, the push-type bolt screw holes 61 and the pull-type bolt screw holes 62 are not necessarily formed alternately, and may be arranged in any manner such as random. Moreover, although the example which formed the screw hole for volt | bolts which becomes a point in each upstream block 50b, 55b, 60b of slot die 50, 55, 60 of FIG. 10 thru | or FIG. 12 was shown in this invention, downstream block 50a, Bolt screw holes may be further formed in 55a and 60a, or bolt screw holes may be formed only in the downstream blocks 50a, 55a and 60a. Further, the number, shape, formation position, and the like of the bolt screw holes in FIGS. 10 to 12 are not limited to those shown in the drawings.
[0035]
In the coating method of the present invention, various known solvents can be used as the solvent for the coating solution. For example, water, various halogenated hydrocarbons, alcohols, ethers, esters, ketones and the like can be used alone or in combination.
[0036]
The coating solution preferably has a viscosity of 0.5 mPa · s to 100 mPa · s and a surface tension of 20 mN / m to 70 mN / m at the temperature during application. The coating speed can be applied in an area of approximately 500 m / min or less.
[0037]
Various known webs can be used as the flexible support. In general, various known plastic films such as polyethylene terephthalate, polyethylene-2,6-naphthalate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide, polyamide and the like can be mentioned. It is done. In addition, various laminated papers obtained by applying or laminating α-polyolefins (repeating units are polymerized from α-olefins having 2 to 10 carbon atoms) such as polyethylene, polypropylene, and ethylene butene copolymers on paper and paper. And so on. Alternatively, a metal foil made of aluminum, copper, tin or the like, such as those obtained by forming a preliminary processed layer on the surface of a belt-like substrate, or various composite materials obtained by laminating these layers are included. Further, the optical compensation sheet coating solution, antireflection film coating solution, magnetic coating solution, photographic photosensitive coating solution, surface protection, antistatic or slipping coating solution, etc. were applied to the web and dried. Later, it may be cut into a desired length and width, and representative examples thereof include, but are not limited to, an optical compensation sheet and an antireflection film.
[0038]
【Example】
The coating apparatus and coating method of the present invention were incorporated into an existing optical compensation sheet manufacturing process. In the optical compensation sheet manufacturing process, the web is fed by a feeder and passes through a rubbing treatment roll while being supported by a guide roll. Thereafter, the coating process of the present invention is incorporated. After that, the basic process is to pass through a drying zone, a heating zone, and an ultraviolet lamp and wind up by a winder.
[0039]
The blocks 20 and 21 were manufactured from SUS630 at a grinding temperature of 23 ° C. and a width L ′ in the coating direction of 1500 mm. These blocks 20 and 21 were assembled as a slot die 13 to produce a coater body 10a. With points P21 to P25 as the reference Ls on one side surface of the coater body 10a, the distance L1 from the reference Ls to P21 is 30 mm, the distance L2 from P22 is 500 mm, the distance L3 from P23 is 750 mm, and the distance L4 from P24 is 1000 mm And the distance L5 of P24 was 1400 mm.
[0040]
[Example 1]
The average clearance C between the downstream end lip 15a and the web 12 using pull bolts, push bolts, push bolts, and pull bolts at points P21, P22, P24, and P25. _ave Was adjusted to 50 μm (see FIG. 9). The temperature of a coating solution to be described later was adjusted to 30 ° C. and fed to the coater 10 for 5 hours for coating. Thereafter, when the clearance between the web 12 and the downstream end lip 15a was measured using a gap gauge at intervals of 10 cm starting from Ls, the variation W was 4 μm. The experimental conditions and results are summarized in Table 1 later.
[0041]
[Examples 2 to 4]
In Example 2, the experiment was performed under the same conditions as in Example 1 except that a pull bolt, a push bolt, and a pull bolt were used for each point of P21, P23, and P25. In addition, Example 3 and Example 4 were also tested under the same conditions as in Example 1 except for the experimental conditions shown in Table 1.
[0042]
[Comparative Example 1 and Comparative Example 2]
In Comparative Example 1, the experiment was performed under the same conditions as in Example 1 except that the temperature of the coating solution was 23 ° C. and the clearance was not adjusted. In Comparative Example 2, the experiment was performed under the same conditions as Comparative Example 1 except that the temperature of the coating solution was set to 30 ° C.
[0043]
[Table 1]

[0044]
It can be seen from Table 1 that when the coating apparatus (coater) according to the present invention is used, the variation in clearance W can be suppressed even if a coating liquid different from the cutting temperature is fed. Furthermore, in the experiment of Example 1 and Example 2 in which the adjustment is performed by attaching the push-type bolt and / or the pull-type bolt to the side surface side and the center side of the slot die, the effect of suppressing the variation W is noticeable. I understood that.
[0045]
[Production and evaluation of optical compensation sheet]
For the web 12, a cellulose triacetate base material (trade name; Fujitac, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 100 μm was used, and before application of the coating solution, long-chain alkyl-modified polyvinyl alcohol (trade name; Poval MP-203). 2% by weight solution of Kuraray Co., Ltd.) ² And dried at 60 ° C. for 1 minute to form an alignment film resin layer. The web 12 on which the alignment layer resin layer was formed in advance was fed, and the surface of the alignment layer resin layer was rubbed to form an alignment layer, which was transported to the coating process as it was for coating. In addition, the rotational peripheral speed of the rubbing roller in the rubbing process is 5.0 m / second, and the pressing pressure against the web 12 is 9.8 × 10. ^-3 Pa was set.
[0046]
In the coating liquid 14, a photopolymerization initiator (trade name; Irgacure 907, Nippon Ciba Geigy Co., Ltd.) was added to a mixture of a discotic compound TE- (1) and TE- (2) shown in Chemical Formula 1 in a weight ratio of 4: 1. The coater under the conditions of Example 1 was used so that the coating layer thickness (wet film thickness) T was 5 μm, using a solution containing a liquid crystalline compound, which was a 40 wt% methyl ethyl ketone solution with 1 wt% of It applied with respect to the web 12 conveyed by 50 m / min. The temperature of the coating solution 14 was 23 ° C. The degree of vacuum was set to 1600 Pa, and the fluctuation range was measured with a digital manometer. The web 12 coated with the coating solution 14 is passed through a drying zone set at 100 ° C. and a heating zone set at 130 ° C., and an ultraviolet lamp (160 W air-cooled metal halide lamp, Eye Graphics Co., Ltd.) is formed on the liquid crystal layer on the surface. Were used for irradiation with ultraviolet rays. After winding, the coating layer 14b was visually inspected. As a result, no step-like unevenness or the like was observed in the coating layer 14b, and the surface state of the coating layer was very good. Thus, it has been found that according to the coating method of the present invention, it is possible to satisfactorily form a coating layer having a wet film thickness of 5 μm.
[0047]
[Chemical 1]

[0048]
【The invention's effect】
As described above, according to the coating method and the coating apparatus of the present invention, even when the block cutting temperature and the temperature of the coating liquid are different, a thin coating layer can be formed continuously and with high accuracy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part for explaining a coating apparatus according to the present invention.
FIG. 2 is a perspective view of the coating apparatus shown in FIG.
FIG. 3 is a view for explaining an embodiment of a member used for clearance adjustment of the coating apparatus according to the present invention.
FIG. 4 is a view for explaining another embodiment of a member used for clearance adjustment of the coating apparatus according to the present invention.
FIG. 5 is a plan view of a main part for explaining an embodiment of clearance adjustment of the coating apparatus according to the present invention.
FIG. 6 is a plan view of an essential part for explaining another embodiment of clearance adjustment of the coating apparatus according to the present invention.
FIG. 7 is a plan view of an essential part for explaining another embodiment of the clearance adjustment of the coating apparatus according to the present invention.
FIG. 8 is a plan view of an essential part for explaining another embodiment of clearance adjustment of the coating apparatus according to the present invention.
FIG. 9 is a plan view of an essential part of the coating apparatus shown in FIG.
FIG. 10 is a main part rear view of another embodiment of the coating apparatus according to the present invention.
FIG. 11 is a main part rear view of another embodiment of the coating apparatus according to the present invention.
FIG. 12 is a main part rear view of another embodiment of the coating apparatus according to the present invention.
FIG. 13 is a plan view of an essential part for explaining an embodiment using the coating apparatus according to the present invention.
[Explanation of symbols]
10 Coater
10a Coater body
12 Web
15a Downstream end lip
20a Upstream block screw hole
32 platform
32a Mounting screw hole
40 pull bolt
41, 43 Lock nut
42 Push-type bolt

Claims (13)

In the coating method of coating the coating liquid from the tip lip of the die supported by the gantry to the web,
A screw member is provided between the back surface of the die opposite to the front end lip and the gantry support portion facing the back surface of the die.
A coating method, wherein the clearance between the tip lip and the web is controlled by separating or approaching the die back surface portion and the gantry support portion with the screw member. The screw member is a pull-type screw member that is screwed into a die-side screw hole provided in the die back surface portion to bring the die back surface portion and the gantry support portion close to each other.
The coating according to claim 1, wherein the coating acts as any one of a push-type screw member that is screwed into a pedestal side screw hole provided in the pedestal support portion and separates the back surface portion of the die and the pedestal support portion. Method. While forming the die side screw hole to which the screw member is attached and the gantry side screw hole at a position where both face each other,
Forming the pedestal side screw hole larger than the die side screw hole;
When the draw screw member is attached to the die side screw hole, the gantry side screw hole acts as a through hole,
The coating method according to claim 2, wherein when the push-type screw member is attached to the gantry-side screw hole, a tip of the push-type screw member abuts on a peripheral portion of the die-side screw hole. The coating method according to any one of claims 1 to 3, wherein a plurality of the screw members are provided in a width direction of the web. 5. The coating method according to claim 1, wherein a plurality of the screw members are provided at a rate of 5 cm or more and 100 cm or less along the coating width direction. 6. The coating method according to claim 1, wherein the screw member is provided within 100 mm from the end of the die. The coating method according to claim 1, wherein variation in the clearance is adjusted within 10 μm along a coating width direction of the die. The coating method according to claim 1, wherein an average clearance between the web and the tip lip is adjusted to 30 μm or more and 100 μm or less. The coating method according to any one of claims 1 to 8, wherein at least the tip lip is formed of a super hard material. The coating method according to claim 1, wherein the coating is performed so that a wet film thickness of the coating layer formed from the coating solution is 25 μm or less. A gantry, and a die that is supported by the gantry and applies a coating liquid from its tip lip to the web;
Provided between a die back surface opposite to the tip lip and a gantry support portion facing the die back surface, and the die lip portion and the gantry support portion are separated or approached to bring the tip lip and the web And a screw member for controlling the clearance with the coating device. The screw member is a pull-type screw member that is screwed into a die-side screw hole provided in the die back surface portion to bring the die back surface portion and the gantry support portion close to each other.
The coating according to claim 11, wherein the coating acts as any one of a push screw member that is screwed into a pedestal side screw hole provided in the pedestal support portion and separates the back surface portion of the die and the pedestal support portion. apparatus. Forming the die side screw hole to which the screw member is attached and the gantry side screw hole at a position where both face each other;
The gantry side screw hole is larger than the die side screw hole,
When the draw screw member is attached to the die side screw hole, the gantry side screw hole acts as a through hole,
13. The coating apparatus according to claim 12, wherein when the push-type screw member is attached to the gantry-side screw hole, a tip end of the push-type screw member comes into contact with a peripheral portion of the die-side screw hole.

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