JP2000000500A - Smoothing roll and painted object subjected to treatment by using the smoothing roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coated surface which is smoothly treated by using a roll which is grooved for the coated surface treatment of a coating layer formed by coating a base material with a coating liquid. SOLUTION: The grooving of the smoothing roll 4 is executed by engraving the mirror finished surface roll itself or winding fine wires thereon or using chemical etching, etc. The angle, depth and number of the grooves are properly selected by coating conditions, as the states of the base material and the coated surface, the state of the coating liquid and a coating weight. The surface of the base material film 7 which is un-wound from an un-winding roll 1 and is subjected to printing, etc., is coated with the coating liquid 8 by a gravure coating method having a gravure roll 3 and thereafter, the coated surface is subjected to the smoothing treatment by the smoothing roll 4. Volatile contents are evaporated to dry the coating in a drying furnace 5. The film is taken up by a take-up roll 6 in the state of averting the occurrence of blocking. The coated object 9 subjected to the smoothing treatment is thus obtd. By which, the defects of the coated surface, such as stripes, when the surface is coated with the coating liquid having a high viscosity and thixotropic property are ameliorated and the smoothly coated surface may be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll for smoothing a coated surface in printing and coating on a substrate such as paper, a plastic film or a metal plate, and a smoothing treatment using the roll. Regarding the coating.

[0002]

2. Description of the Related Art For example, when printing or coating a substrate (hereinafter referred to as a substrate) such as paper or plastic film,
In order to obtain or maintain the smoothness of the coated surface, transfer the ink or coating agent (hereinafter referred to as coating liquid) from the plate to the substrate, and then print and coat before drying and completely forming the coating film. A mirror plate (hereinafter, referred to as a smoothing roll) rotated in the reverse or natural direction with respect to the surface (hereinafter, referred to as a coated surface) with respect to the flowing direction of the substrate was applied to the substrate.

As described above, by applying a smoothing roll, a physical leveling action on a coated surface and uneven distribution of a chemical substance are leveled, and the coated surface is often smoothed. In addition, by heating the smoothing roll, the temperature of the coating liquid on the coating surface rises instantaneously, thereby reducing the uneven distribution of the coating liquid additive due to the decrease in viscosity and synergistic effect by applying the smoothing roll. In many cases, the coated surface became good.

[0004] However, depending on the type of the coating liquid, there is a case where the smoothness of the coated surface cannot be obtained even by the above method.

[0005] The types of coating liquids that do not provide smoothness of the coated surface include:
Particularly, a water-soluble coating liquid, an aqueous emulsion coating liquid, a non-solvent coating liquid, a high-viscosity coating liquid, a coating liquid containing a filler such as an inorganic material, or the above-mentioned coating liquid, and a coating liquid having a high thixotropic property, etc. .

[0006] In the case of such a coating liquid, the coating liquid is transferred from the plate, and even when a mirror-like smoothing roll is applied, the coating surface becomes uneven or has a streak-like surface state. There was a problem that was not obtained.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to provide a method for coating and coating a substrate such as paper, a plastic film and a metal plate. It is an object of the present invention to provide a smoothing roll for smoothing a surface and a coated product having a smooth coated surface that has been subjected to a smooth treatment using the roll.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to improve the above problems, and have reached the following invention.

The invention according to claim 1 is characterized in that the roll for smoothing the coating surface of the coating layer formed by coating the substrate with the coating liquid is a grooved roll. Smoothing roll.

According to a second aspect of the present invention, in the smoothing roll according to the first aspect, the groove has a depth satisfying a range of 10 to 300 μm.

[0011] The invention according to claim 3 is the invention according to claim 1 or 2.
In the smoothing roll according to the present invention, assuming that the flow direction of the coating liquid is 0 °, the groove is a diagonal groove in a range of 0 to 180 ° and at least one diagonal groove that does not intersect is formed.
It is characterized by being applied.

The invention according to claim 4 is the first or second invention.
In the smoothing roll described above, when the flow direction of the coating liquid is 0 °, the grooves are diagonal grooves in a range of 0 to 180 degrees, and two or more diagonal grooves intersect symmetrically or asymmetrically. It is characterized by having been given.

According to a fifth aspect of the present invention, using the smoothing roll according to any one of the first to fourth aspects, a coating surface of a coating layer formed by applying a coating liquid to a substrate is smoothed. It is a coated product characterized by having been subjected to the following.

[0014]

Embodiments of the present invention will be described below in detail. The method of forming grooves in the roll of the present invention includes a method of carving a mirror-like roll itself, a method of winding a thin wire like a wire bar, or a method of forming grooves using chemical corrosion or the like, but is not particularly limited. Not something.

As for the groove, the angle of the groove is also an important factor. The condition of the groove angle can be varied up to 180 degrees when the coating flow direction is 0 degree. The effect of the angle of the groove varies depending on the coating liquid used, and therefore it is preferable to appropriately select the angle depending on the substrate, the state of the coated surface, the state of the coating liquid, and the coating conditions. Usually, a range of 20 degrees to 170 degrees seems to be preferred. Especially from 30 degrees
60 °, 120 ° to 150 ° are particularly preferred.

Further, it is necessary to consider a factor of the depth of the groove. The depth is between 10 and 300 μm. It may be appropriately selected from coating conditions such as the substrate, the state of the coated surface, the state of the coating liquid, and the amount of coating, but is preferably about 20 to 200 μm.

The number of grooves need not be one, and it may be better to provide a plurality of grooves. In that case,
It is possible to form grooves at symmetrical or asymmetrical angles.However, in terms of equalizing excess coating liquid and obtaining a smooth surface, it depends on the coating liquid and coating conditions at that time. A symmetrical angle groove may be preferred. In this case, symmetric,
Asymmetric means that the direction of flow is 0 degree, so that the direction opposite to the flow is 180 degrees, which is also symmetric. For example, 50 degrees and 130 degrees, and 70 degrees and 110 degrees are symmetric. Intersection is asymmetric.

Further, when a plurality of grooves are formed, the depth of each groove may be changed within the range of 10 to 300 μm, but it is preferable that each groove has the same depth.

The number of grooves is not particularly limited because it is determined by the depth and angle of the groove.

When the smoothing roll of the present invention is disposed on the coating surface of the coating layer, the coating surface depends on the coating conditions such as the base material, the state of the coating surface, the amount of coating, and the depth and angle of the groove of the smoothing roll used. However, it is not particularly limited, but is preferably applied horizontally to the painted surface, and the degree of the application may be determined while appropriately observing the condition of the painted surface.

In addition, with respect to a certain grooved smoothing roll, the application thereof may be not only horizontally but also at a certain angle, whereby the angle of the groove with respect to the coating surface changes, It is also possible to find an appropriate angle with one groove angle, and it is also possible to find the best painted surface with one groove angle by fixing at that angle. In particular, the same applies to a roll having a plurality of grooves. By this operation, a condition for obtaining an optimum coating surface can be found, and a roll meeting the condition can be produced.

The rotation speed of the smoothing roll is also the same as above.
At this time, depending on the rotation direction and the coating speed, it is necessary to check the coating surface condition by using the base material, the coating surface, the coating conditions, the groove depth and angle of the smoothing roll used, and the coating speed at that time.
The rotation speed in the range of 000 rpm / min may be appropriately selected, but the rotation speed is more preferably 10 to 100 rpm / min. Also, in some cases, the rotation direction of the roll is
Depending on the roll used, the roll may be rotated not only in the reverse direction but also in the natural direction.

The raw material of the smoothing roll of the present invention is not particularly limited, but may be a commonly used material. It is better to match the motor capacity of the machine to be used.If the motor capacity is small, the motor may be overloaded or the rotation speed may not increase. It is good to use what you have done. Further, it is more preferable that the surface is subjected to chrome plating, polishing, or the like.

At this time, with respect to the coating liquid to be applied, the coating liquid formed between the coating and the smoothing roll is hardened or solidified, and the coating liquid which does not serve the function of smoothing is removed. The solvent is not particularly limited, and examples thereof include a solvent type (solvent dilution type), an aqueous type (water dilution type), a non-solvent type, and a hot melt type. In addition, as a matter of course, not only one kind but also two or more kinds of coating liquids may be mixed in the coating liquid, and an inorganic filler or an additive as needed may be mixed in the coating liquid. it can.

The substrate that can be used in the present invention is also not particularly limited, and may be any substrate that can be generally coated, such as paper, plastic film, and metal (foil or plate). Those that can withstand the tension caused by applying the roll are still better.

Regarding the coating method that can be used in the present invention,
There is no problem with ordinary coating methods such as gravure coating, roll coating, gravure offset coating, microgravure coating, and comma coating, and there is no particular limitation. There is no particular problem as long as the smoothing roll of the present invention can be attached.

FIG. 1 illustrates a process for producing a coated article using the smoothing roll of the present invention. The coating liquid 8 is applied to the surface of the base film 7 that has been printed or the like unwound from the unwinding roll 1 by a gravure coating method including the gravure roll 3 as an example, and is then provided in a coating apparatus. After the coating surface is subjected to a smoothing treatment by the smoothing roll 4 of the present invention, the volatile matter is blown off in the drying furnace 5 and dried, and the coating material 9 is wound up by the winding roll 6 in a state where blocking does not occur. Can be obtained.

<Effect> Conventionally, when a coating solution having a high viscosity and a high thixotropic property is applied, a smoothing roll having only a mirror surface does not improve the coating surface defect and cannot form a smooth coating surface. However, by using a smoothing roll containing grooves such as diagonal lines of the present invention, even on a rough substrate such as a plastic film or a metal plate, to smooth the coating surface in printing and coating on the substrate. By promoting smoothing of the knitting of the coating liquid on the coated surface using the smoothing roll and the smoothing roll, it is possible to provide the coated product having a smooth coated surface.

[0029]

The present invention will be described below in more detail with reference to examples. However, the present invention is not limited by these.

<Example 1> Table 1 shows the winding of a polyester film (E5100, 25 µm, manufactured by Toyobo Co., Ltd.) on which white solid printing was performed using a gravure coating machine equipped with a drying path and a smoothing roll. The coating solution having the formulation shown was coated using a gravure plate (oblique engraving 120 L, 85 μm), after which a smoothing roll was set, reversely rotated, rotated at 20 rpm, and rotated at a line speed of 5 rpm.
After flowing at 0 m / min, the volatile components were removed in a drying path and dried to prevent blocking, and then wound up to prepare a sample. The smoothing roll used at this time had an angle of 45 °, a plate depth of 50 μm, and a single groove.

[0031]

[Table 1]

Example 2 A sample was prepared in the same manner as in Example 1 except that the grooves of the smoothing roll used were symmetrical at 45 ° and 135 °, and the plate depth was 50.
μm one was used.

Example 3 A sample was prepared in the same manner as in Example 1, except that the grooves of the smoothing roll used were two asymmetrical ones having angles of 45 ° and 145 °, and the plate depth was 5 for both.
The thing of 0 μm was used.

<Comparative Example 1> A sample was prepared in the same manner as in Example 1, except that the smoothing roll used had no grooves and was a so-called mirror-finished plate (bose plate).

In the evaluation method, the painted surface on the wound film is visually judged. The evaluation of the visual judgment was evaluated on a three-point scale and defined as follows. ×: A state in which uneven or streaky coating marks are left on the coated surface and the coated surface is rough. ●: The coating surface is almost in good condition, although some uneven or streaky coating marks are observed on the coating surface. ：: The coating surface is uniformly leveled without unevenness or streaky coating marks, and the coating surface is good.

At the same time, the gloss of the coated surface was measured and determined as one factor of the smoothness of the coated surface. The gloss was measured by specular reflection at 60 ° using a gloss meter (manufactured by Big Chemie).
As an index, it is assumed that the higher the gloss value, the smoother the coated surface.

[0037]

[Table 2]

As can be seen from the results in Table 2, the effect of the smoothing treatment of the smoothing roll of the present invention is clearly recognized from the results of the visual evaluation of the coated surface and the results of the glossiness of the coated surface.

[0039]

According to the present invention, it is possible to improve the coating surface such as streaks of a coating layer obtained by coating a coating solution having a high viscosity and a high thixotropic property, and to obtain a coating having a smooth coating surface. Things are obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a production process of a coated article using a smoothing roll of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Unwinding 2 ... Nip roll 3 ... Gravure roll 4 ... Smoothing roll 5 ... Drying furnace 6 ... Winding 7 ... Base film 8 ... Coating liquid 9 ... Coating

Claims (5)

[Claims] 1. A smoothing roll, which is a roll provided with a groove in a roll for smoothing a coating surface of a coating layer formed by coating a base material with a coating liquid. 2. A smoothing roll according to claim 1, wherein said groove has a depth satisfying a range of 10 to 300 μm. 3. The groove is characterized in that, assuming that the flowing direction of the coating liquid is 0 °, at least one diagonal groove is formed in a range of 0 to 180 ° and does not intersect each other. The smoothing roll according to claim 1 or 2, wherein 4. When the flow direction of the coating liquid is 0 °, the grooves are diagonal grooves in the range of 0 to 180 °, and two or more diagonal grooves intersect symmetrically or asymmetrically. The smoothing roll according to claim 1, wherein the smoothing roll is provided. 5. A coating layer formed by applying a coating liquid to a substrate by using the smoothing roll according to claim 1 to smooth the coating surface. Coated product characterized.