JP2005103426A - Manufacturing method of sheet-like coated material and coater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method that is capable of rapidly coating both sides of a sheet-like material to be coated and forming a film excellent in appearance and having a high thickness accuracy even if the thickness of the material to be coated is small, and to provide an apparatus therefor. <P>SOLUTION: The coating apparatus arranges two coating rolls at a distance that are contacted with each other or closely contacted with each other and that grips the sheet-like material to be coated so that the face to be coated becomes parallel to the gravity direction and of which the rotation shaft is parallel to the gravity direction and of which the surface is comprised of an elastomer in order to grip the material to be coated from both faces. The coated sheet-like material is prepared by passing the material to be coated through the two rolls impregnated with a coating solution while horizontally transferring at least one of the material to be coated and the coating rolls and rotating the coating rolls to the same direction as the proceeding direction of the material to be coated, thereby simultaneously forming the film on both faces of the material to be coated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides materials, colorants, and the like that impart various functions such as scratch resistance, antistatic properties, antireflection properties, antifouling properties, antifogging properties, and light absorption properties to sheet-shaped plate-shaped molded products. The present invention relates to a method for producing a plate-like coating material in which various functional films, protective films, colored films, design films and the like are formed by applying a coating solution containing the coating liquid, and a coating apparatus suitable for use in the method.

As a method for simultaneously applying a plate-shaped object to be coated simultaneously, for example, in Japanese Patent Application Laid-Open No. 2002-143739 (Patent Document 1), a rotating shaft is passed between two coating rolls that are substantially vertical. It has been proposed that the distance between the two coating rolls may be about 20 to 100% of the thickness of the coating object when the surface is made of an elastic body. Japanese Patent Laid-Open No. 2002-254002 (Patent Document 2) proposes that the rotation axis pass between two coating rolls that are substantially horizontal, and the interval between the two coating rolls is as follows. It is described that when the surface is made of an elastic body, it should be equal to or larger than the thickness of the object to be coated, and may be smaller than the thickness of the object to be coated.
JP 2002-143739 A JP 2002-254002 A

  However, in these conventional methods, if the thickness of the object to be coated is small, the appearance of the film may be deteriorated, or the film thickness accuracy of the film may not be sufficient.

  Accordingly, the present inventors have developed a coating method and an apparatus therefor that can apply both surfaces of a plate-shaped object at the same time quickly, and are excellent in the appearance and film thickness accuracy of the film even when the thickness of the object is small. As a result of diligent research to develop, two application rolls whose rotation axis is almost vertical are arranged at an interval where they are in contact or in close contact with each other in an unloaded state, and the surface to be coated is drooped almost vertically. It was found that by passing a plate-shaped object to be coated, a film having the desired appearance and film thickness accuracy was formed, and a coated product could be produced with high productivity, and the present invention was achieved.

  That is, the present invention grips a plate-shaped object so that the surface to be coated is substantially parallel to the direction of gravity, and the rotation axis is substantially parallel to the direction of gravity so that the object is sandwiched from both sides. Two coating rolls whose surfaces are made of an elastic body are arranged at intervals that contact or closely contact each other in a state where the object to be coated is not sandwiched, and at least one of the object to be coated and the coating roll is moved in the horizontal direction, and While rotating the coating roll in the same direction as the traveling direction of the coated object, the coated film is simultaneously formed on both surfaces of the coated object by passing the coated object between the two coating rolls with the coating liquid. And providing a method for producing a plate-like coated product.

  According to the present invention, there is also provided a coating apparatus suitable for this method. The coating apparatus grips a plate-shaped coated object so that the coated surface is substantially parallel to the direction of gravity. The fixing means, the rotation axis is substantially parallel to the direction of gravity, the surface is made of an elastic body, and in a state where the object to be coated is not sandwiched, they are arranged at an interval in contact with or in close contact with each other, and the same direction as the traveling direction of the object to be coated A coating roll means having two coating rolls that rotate in rotation, a transport means for moving the object to be coated or the coating roll means in the horizontal direction, and a coating liquid supply means for supplying the coating liquid to the coating roll. By passing the object between two coating rolls, the coating film is formed simultaneously on both surfaces of the object to be coated.

  According to the method of the present invention, both sides can be applied simultaneously at a high application rate, and the coating film has a good appearance and high film thickness uniformity even for a thin plate-like object to be coated. Can be formed. Moreover, according to this invention, the coating device suitable for this method is also provided.

  Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 schematically shows a state where a plate-like object is applied according to the present invention, wherein (A) is a perspective view and (B) is a BB line in (A). It is a longitudinal cross-sectional view which follows. The plate-like object 1 is suspended so that the surface to be coated is substantially parallel to the direction of gravity, and rotation shafts 3 and 3 that are substantially parallel to the direction of gravity are provided so as to sandwich the object 1 to be coated from both sides. The two coating rolls 2 and 2 are disposed, the coating object 1 is passed between the coating rolls 2 and 2, and the coating liquid supplied in advance to the surfaces of the coating rolls 2 and 2 is coated with the coating object 1. It is applied to the surface (surface to be coated).

  In order to pass the coating object 1 between the coating rolls 2 and 2, the coating object 1 may be moved in the horizontal direction as shown by the white arrow in FIG. As shown, the application rolls 2 and 2 may be moved in the horizontal direction, or both the article 1 and the application rolls 2 and 2 may be moved in the horizontal direction.

  The type of the plate-like object 1 is not particularly limited, and for example, plate glass or a resin molded product is used. Examples of the resin molded article include (meth) acrylic resins, polycarbonate resins, polyester resins, cellulose resins, polystyrene resins, styrene- (meth) acrylate copolymer resins, and the like.

  Although there is no special restriction | limiting also in the dimension of the to-be-coated article 1, Usually, width is 300-2000 mm and length is about 500-4000 mm. The relationship between the width and the length here is that the long side of the rectangle is the length and the short side is the width. At least one of the four sides of the workpiece 1 is fixed and gripped. Although FIG. 2 shows a state in which the length direction of the workpiece 1 is the upper side and is fixed by the fixed frame 4, it may be fixed with the width direction as the upper side. The coated object 1 has a coated surface substantially parallel to the direction of gravity, that is, the normal of the coated surface indicated by an arrow in FIG. 2B is substantially parallel to the ground. Are arranged as follows.

  Moreover, there is no special restriction | limiting also in the thickness of the to-be-coated object 1, Usually, it is about 0.05-20 mm, However, The method of this invention is an external appearance and film thickness also to the to-be-coated object with small thickness. Since the coating film excellent in accuracy can be formed advantageously, the coated object 1 having a small thickness of about 0.05 to 1 mm is suitably applied.

  The method for fixing the workpiece 1 is not particularly limited. For example, as shown in FIG. 3, several holes 7 and 7 are formed in a portion near the end of the side to be fixed, and a string is formed in the holes 7 and 7. It may be hung from the fixed frame 4 by passing the hanging tools 6 and 6 such as wire or wire, and as shown in FIG. 4, it is fixed by being clamped by clamping means 8 and 8 such as a vise or a fixing screw. It may be fixed to the frame 4. As shown in FIGS. 2 to 4, the upper side gripping part of the object 1 gripped by the fixing means usually passes above the part sandwiched between the coating rolls 2 and 2 so that the coating liquid is not applied thereto. Although not shown, such fixing means are not shown in other drawings. Further, the upper side grip portion where the coating liquid is not applied in this way and thus the coating film is not formed is usually cut off after the coating is completed.

  The fixed object 1 and / or application rolls 2 and 2 are moved at a constant speed in the horizontal direction as indicated by white arrows or black arrows in FIG. When moving the workpiece 1, for example, as shown in FIG. 2, transport means such as a conveyor 5 can be used. The moving speed of the article 1 is not necessarily limited, but usually a value of about 0.5 to 20 m / min is employed. If the moving speed is too slow, the productivity is lowered, and if it is too fast, the surface of the coating film may be disturbed.

  As shown in FIG. 1, the coating object 1 passes between two parallel coating rolls 2 and 2 to which a coating solution is adhered, whereby a coating film is formed on the surface thereof. The size of the coating rolls 2 and 2 is appropriately selected according to the size of the object to be coated 1, and usually a roll 10 to 1000 mm longer than the length in the width direction of the object to be coated 1 is used. The diameter of the roll is not particularly limited, but is usually about 50 to 500 mm in diameter.

  The surfaces of the coating rolls 2 and 2 are made of an elastic body, and generally, an elastic material such as rubber or resin that has resistance to the coating liquid is appropriately selected. For example, a coating solution containing an organic solvent is appropriately selected from butyl rubber, ethylene-propylene rubber, nitrile rubber, styrene-butadiene rubber, silicone rubber, urethane resin, fluororesin, and the like depending on the solvent used. The thickness of the elastic layer on the surface of the coating rolls 2 and 2 is not particularly limited, but is usually about 3 to 50 mm. This elastic body preferably has a hardness of about 20 to 80 degrees as measured by a spring type hardness test A defined in JIS K 6301.

  Further, the distance between the two coating rolls 2 and 2 is maintained such that the surfaces are in contact with each other or in close contact with each other when there is no load, that is, in a state where the object to be coated is not sandwiched. Here, the value obtained by subtracting the sum of the roll radii when the coating rolls 2 and 2 are held individually (no load) from the distance between the rotation shafts 3 and 3 of the coating rolls 2 and 2 is expressed as “roll interval”. "Roll interval" is 0 mm or less, preferably -3 to 0 mm. By adopting such a roll arrangement, it is possible to advantageously form a film excellent in appearance and film thickness accuracy even on an object having a small thickness.

  The two coating rolls 2 and 2 may each have a driving means such as a motor for rotational driving, and can be freely rotated with the movement of the object 1 without the driving means. It may be. These coating rolls 2 and 2 are rotated in the same direction as the traveling direction of the workpiece 1. For this reason, the direction of rotation differs between the two coating rolls 2 and 2. The rotation speed of the coating rolls 2 and 2 is not particularly limited, and is appropriately selected according to the diameter of the roll and the moving speed of the article 1 or the coating rolls 2 and 2, but is usually in the range of about 0.05 to 50 rpm. Is preferred. In terms of rotational peripheral speed, the speed is about 0.1 to 20 m / min.

  The surfaces of the coating rolls 2 and 2 may be flat or uneven. Further, in order to adjust the coating film to a desired thickness, fine grooves 9 can be formed on the surfaces of the coating rolls 2 and 2 as shown in FIGS. As the shape of the fine grooves formed on the surfaces of the coating rolls 2 and 2, for example, a V-shaped cross section as shown in FIGS. 5A and 5B, FIG. And a semicircular shape as shown in FIG. 5 and a trapezoidal shape as shown in FIG. As shown in FIGS. 6A and 6B, a plurality of fine grooves 9 may be formed concentrically on the coating rolls 2 and 2, or (C) and (D) in FIG. ), One or more may be formed in a spiral shape, and further, as shown in FIG. Good. Although the depth of the fine groove | channel 9 is not specifically limited, Usually, it is 0.01-1 mm. Moreover, the distance (groove interval) between the central portion of the groove and the central portion of the adjacent groove is not particularly limited, but is usually 0.01 to 5 mm. Between the groove and the adjacent groove, there may be a flat portion as shown in FIGS. 5A, 5C, and 5D, or a flat portion as shown in FIG. 5B. It does not have to be.

  The diameter of the coating rolls 2 and 2 is usually constant from one end to the other end, but in order to keep the pressure applied on the workpiece 1 constant, as shown in FIG. A crown may be provided in the length direction of the coating rolls 2 and 2 so that the diameter of the central portion is slightly larger than the end portion. Further, in the coating method of the present invention, since the film thickness of the upper part in the vertical direction tends to be thin due to gravity due to the vertical arrangement of the object 1, as shown in FIG. The diameter of the roll can be tapered so that the diameter of the upper part of the roll is slightly reduced. Even when the diameter of the roll is changed in this way, it is appropriate that the ratio of the change is such that the diameter of the smallest part is 90% or more, further 99% or more with respect to the diameter of the largest part. It is.

  A coating solution is supplied onto the coating rolls 2 and 2. Usually, it is preferable to supply the coating liquid so that the coating liquid adheres to the entire surface of the coating rolls 2 and 2 before coming into contact with the workpiece 1. In supplying the coating liquid onto the coating rolls 2 and 2, the coating liquid may be distributed over the entire surface at the contact portion with the object to be coated 1. For example, as shown in FIG. A method can be employed in which a coating liquid supply means 10 for a roll such as a flow nozzle is provided on the upper part, and the coating liquid flows down from there. The supply amount of the coating solution is usually appropriately selected from the range of about 0.1 to 2 L / min. In addition, in order to remove excess coating liquid adhering to the coating rolls 2 and 2, the surface of the roll is attached to the surface of the roll just before coming into contact with the coating object 1 by scraping means such as a metal or resin bar, rod, roll or blade. For example, as shown in FIG. 9, the doctor bars 11 and 11 may be disposed so as to come into contact with the surfaces of the coating rolls 2 and 2 as scraping means.

  Before the coating object 1 comes into contact with the coating rolls 2 and 2, a film made of a coating solution may be formed on the surface of the coating object 1 in advance by flow coating. For example, as shown in FIG. It is possible to employ a method in which a coating liquid supply means 12 for an object to be coated such as a flow nozzle is provided on the top of the coated material 1 and the coating liquid is caused to flow from there. Although the amount of liquid of a flow is not specifically limited, For example, if it flows on the to-be-coated article 1 with the width | variety of about 5-10 cm, about 1-5 L / min is normally preferable on the single side | surface of the to-be-coated object 1. This amount varies depending on the area of the flowing part. By performing flow coating in advance, it is possible to wash away the dust adhering to the surface of the object to be coated 1, and the appearance of the obtained coated material is improved. Further, in this case, even if a large amount of coating film is formed on the object to be coated 1, since the remaining parts are removed by the coating rolls 2 and 2, the dust on the object to be coated 1 is removed. In addition, the influence of dust on the coating rolls 2 and 2 can be reduced.

  In the present invention, the coating liquid is preferably circulated by a circulation means such as a pump. For example, as shown in the flowchart of FIG. 11, the coating liquid 31 is pumped from the tank 30 containing the coating liquid 31 by the pump 33 via the valve 34, and then branched to the coating liquid supply means 10 for rolls. What is necessary is just to supply to the upper part of each of the 10 coating rolls 2 and 2 from 10. Further, when supplying the coating liquid to the surface of the coating object 1, the pumping liquid 31 is pumped up by the pump 33, and then the coating liquid is branched. One may be piped as a flow to the coating rolls 2 and 2. In FIG. 11, the pressure of the coating liquid pumped up by the pump 33 is detected by the pressure gauge 40 via the valve 35 and branched via the valve 36, one of which is the valves 37 and 37 and the flow meters 42 and 42. To the coating liquid supply means 10 and 10 for rolls, and the other is guided to the coating liquid supply means 12 and 12 for coating objects via valves 38 and 38 and flow meters 43 and 43. It has come to be. The pressure gauge 40 is preferably provided in order to detect an abnormality such as a clogged pipe.

  Immediately after being pumped up by the pump, or before being supplied to the rolls 2 and 2 or the object to be coated 1, the coating liquid is cleaned with a filter or the like to remove dust that may be contained in the coating liquid. It is preferable to do so. In FIG. 11, a filter 45 is arranged and filtered before the path of the coating liquid branches for the roll and the object to be coated. Further, of the coating liquid pumped up by the pump, the remainder after being routed to the supply path to the coating rolls 2 and 2 and the workpiece 1 returns to the tank 50 through the bypass 50 having the valve 39. It has become. Furthermore, it is preferable that the excess coating liquid after flowing onto the rolls 2 and 2 and the excess coating liquid after flowing onto the article to be coated 1 if necessary are recovered and returned to the tank 30. In FIG. 11, excess coating liquid generated in the flow to the coating rolls 2 and 2 passes from the recovery path 52, and excess paint generated in the flow to the coating object 1 flows from the recovery path 53 to the tank 30. It is supposed to be returned.

  By the method described above, a coating film of the coating solution is formed on the article 1 to be coated. Thereafter, the object to be coated 1 is made into a product by drying and removing the solvent contained in the coating solution. Alternatively, after removal of the solvent, the film is cured by crosslinking, polymerization, or the like by heating or irradiation with activating radiation such as ultraviolet rays or electron beams as necessary, to produce a product.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples. The percentages in the examples are by weight unless otherwise specified.

Example 1
As an object to be coated, an acrylic resin plate (Sumitomo Chemical Co., Ltd., Sumipex E000) having a width of 1000 mm, a length of 2000 mm, and a thickness of 0.8 mm is used. Were conveyed at a conveyance speed of 3.0 m / min. In addition, a coating material obtained by diluting a hard coat agent (manufactured by Shin-Nakamura Kagaku, NK Hard M-101; paint containing 80% urethane acrylate compound) to 40% with ethylene glycol monoethyl ether was used as the coating solution.

The outline of the apparatus used in this example and the flowchart of the coating liquid circulation are as shown in FIGS. 10 and 11, respectively. As the coating rolls 2 and 2, a surface layer having a thickness of about 10 mm was formed of butyl rubber having a hardness of 40 degrees (JIS K 6301 A method), and two rolls having a length of 1350 mm and a diameter of 150 mm were used. In this coating roll, V-shaped grooves (groove angle of 90 degrees) having a depth of 0.15 mm and an interval of 0.5 mm are formed on the surface in parallel with the line traveling direction. The supply amount of the coating liquid to the two coating rolls 2 and 2 was 0.5 L / min per one, and the rotation peripheral speed of the coating rolls 2 and 2 was 3.0 m / min. The distance between the two coating rolls 2 and 2 was 0 mm in a state where they were in contact with each other at no load, that is, the “roll distance” defined above. Furthermore, the coating liquid was flow-coated at 3.0 L / min on both surfaces of the coating object 1 before the coating object 1 passed through the coating rolls 2 and 2. The time required for coating was about 40 seconds. The coated object 1 after coating was dried at 40 ° C. for 10 minutes, and then irradiated with 500 mJ / cm ² of ultraviolet rays to cure the coating.

  The film thickness of the cured film was measured at a 50 mm interval in the width direction of the coated product (vertical direction during conveyance) using a microscopic film thickness meter (manufactured by Otsuka Electronics Co., Ltd., MS-2000), and the results are shown in FIG. It was. The difference in film thickness was within 5 μm, and the appearance of the obtained coated product was good with no uneven coating due to paint disturbance.

Example 2
Example 1 except that the interval between the two application rolls 2 and 2 was 0.5 mm pressed in close contact with each other when no load was applied, that is, the previously defined “roll interval” was −0.5 mm. The same operation was performed. The film thickness measurement results are shown in FIG. The difference in film thickness was within 5 μm, and the appearance of the obtained coated product was good with no uneven coating due to paint disturbance.

Comparative Example 1
The same operation as in Example 1 was performed except that the interval between the two coating rolls 2 and 2 was 0.5 mm at no load, that is, 0.5 mm with the previously defined “roll interval”. The film thickness measurement results are shown in FIG. The film thickness difference was about 10 μm, and periodic coating unevenness occurred in the obtained coated product as shown in FIG.

The state currently apply | coated to a plate-shaped to-be-coated article is shown typically, Comprising: (A) is a perspective view, (B) is a cross-sectional view which follows the BB line of (A). An example of a gripping state of an object to be coated and a conveying means are schematically shown, wherein (A) is a front view and (B) is a side view. An example of a holding means is shown typically, and (A) is a front view and (B) is a side view. An example of another holding means is shown typically, and (A) is a front view and (B) is a side view. It is the partial expanded cross-section schematic diagram of the application roll which shows some examples about the cross-sectional shape of the groove | channel provided in the surface of an application roll. It is a front view which shows some examples typically about the direction of the groove | channel provided in the surface of an application roll. It is a front view which shows typically the example from which the cross-sectional diameter of an application roll is changing from the upper part to the lower part. It is a perspective view which shows typically the state which attached | subjected the coating liquid supply means to the coating roll. It is a perspective view which shows typically the state which attached | subjected the scraping means to the application roll. It is a perspective view which shows typically the state which attached | subjected the coating liquid supply means to the to-be-coated object. It is a flowchart which shows an example in the case of circulating a coating liquid. It is a graph showing the film thickness distribution of the coated material surface obtained in Examples 1 and 2 and Comparative Example 1. It is a front view which shows typically the state of the coated material surface obtained by the comparative example 1. FIG.

Explanation of symbols

1 …… Substance to be coated
2 ... coating roll,
3 …… Coating roll rotating shaft,
4 ... Fixed frame,
5 ... Conveyor 6 ... Suspension tool,
7 …… Hole,
8 …… Fixing screw,
9 …… Coating roll groove,
10: Roll coating liquid supply means (flow nozzle)
11 …… Doctor bar 12 …… Coating liquid supply means (flow nozzle)
30 …… Tank
31 …… Coating solution,
33 …… Pump,
34, 35, 36, 37, 38, 39 ... valves,
40 …… Pressure gauge,
42, 43 …… Flow meter,
45 …… Filter,
50 …… Bypass,
52, 53... Application liquid recovery path.

Claims (2)

  The plate-shaped object is gripped so that the surface to be coated is substantially parallel to the direction of gravity, and the rotation axis is substantially parallel to the direction of gravity and the surface is an elastic body so that the object to be coated is sandwiched from both sides. Two coating rolls made of the above are disposed at intervals where they are in contact with or in close contact with each other when no object is sandwiched, and at least one of the object to be coated and the coating roll is moved in the horizontal direction, and the coating roll is coated. It is characterized in that a coating film is simultaneously formed on both surfaces of a coating object by passing the coating object between two coating rolls with a coating liquid while rotating in the same direction as the traveling direction of the coating. A method for producing a plate-like coated product. Fixing means for the object to be gripped so that the surface to be coated is almost parallel to the direction of gravity, the rotation axis is almost parallel to the direction of gravity, and the surface is made of an elastic material. In the state where the object is not sandwiched, the application roll means having two application rolls that are arranged at an interval in contact or in close contact with each other and rotate in the same direction as the traveling direction of the application object, the application object or the application roll means in the horizontal direction And a coating liquid supply means for supplying the coating liquid to the coating roll. By passing the coating between the two coating rolls, both surfaces of the coating are coated simultaneously. A coating apparatus characterized in that the coating device is formed.

Images