JP3222920B2 - Plate making method of wood channel groove embossing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of making an embossing plate that faithfully reproduces the shape and the continuous distribution of the depth of a conduit groove in a natural woodgrainboard by a photo-corrosion method.

[0002]

2. Description of the Related Art Conventionally, as a method of making an embossing plate for reproducing the shape of a wood grain conduit groove, a method of engraving a plate material surface using a mill having irregularities reverse to that of the embossing plate, or a method of making a mold from a natural wood grain board. Take, and electroplate on the mold,
A method of releasing a mold after growing a metal is known.

[0003]

However, the embossing plate obtained by the above-mentioned method using a mill cannot reproduce the continuous distribution of the shape and depth of the wood-grain conduit groove, and has a problem in terms of design. In the method using electroplating, it is possible to obtain an embossed plate that can faithfully reproduce the continuous distribution of the shape and depth of the conduit groove of the wood grain board,
The plate making method itself consists of several types of complicated steps such as molding, inversion of male and female molds, conductive treatment of molds, plating, etc.
There is also a problem in terms of plate making costs.

[0004] An object of the present invention is to solve the above problems.
It is an object of the present invention to provide a method for easily and inexpensively making an embossing plate capable of faithfully reproducing the shape of a conduit groove and its continuous depth.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a method for optically transmitting light through a continuous shallow portion of a conduit groove such that the deeper the groove is, the lower the optical transmission density becomes. The negative-grained original film of the wood grain board converted to the density is baked on a photosensitive negative resist film, the resist film is transferred onto a metal plate material surface, and unexposed portions are removed. Disclosed is a plate making method for embossing a wood-grain conduit groove, characterized in that a thinner portion of the resist film acts on the plate material to perform corrosion so that the plate material has a greater corrosion depth, and a thicker portion has a smaller corrosion depth.

In the present invention, a photosensitive positive resist film is transferred onto the surface of a metal plate material, and the resist film is formed so that the optical transmission density becomes higher as the depth of the conduit groove on the grained wood surface increases. Continuous deep and shallow, bake the wood original board film corresponding to the optical transmission density, then remove the unexposed part of the resist film, and further act on the plate material with a corrosive liquid on the resist film, the resist film Disclosed is a plate making method for embossing a wood grain conduit groove, characterized in that corrosion is performed such that a thinner portion has a greater corrosion depth of the plate material and a thicker portion has a smaller corrosion depth.

After the corrosion is completed by the above method, a step of forming a metal film having higher wear resistance and / or chemical resistance than the plate material on the plate material surface, or matte surface roughening treatment of the plate material surface , A step of forming a metal coating having higher abrasion resistance and / or chemical resistance than the plate material can be added. In addition, the above method uses a gravure screen at the time of printing, and quantizes the image of the original film into cells, but since the image of the conduit groove is extremely delicate, when divided into cells, the natural shape is obtained. Will be different. Therefore, the present invention discloses a method of printing an original film without using a gravure screen in order to faithfully reproduce a natural conduit groove.

Further, when printing is performed without using a gravure screen in accordance with the above method, the conduit grooves are formed of thin lines (about 1 mm or less in width) isolated from each other. There is a disadvantage that the resist film is peeled off due to the penetration of the corrosive liquid into the gap between the peripheral portion of the resist film and the projection of the plate material caused by the formation of the height difference on the plate material surface due to the shearing force and the corrosion.

In order to solve this problem, the present invention prints an original film provided with a conduit groove pattern having the same exposure amount during printing, an optical transmission density of two gradations of black and white, and a gravure screen provided. 130% of the value when
A method of increasing the resist film strength to 150%, which is higher than usual, and a conduit groove pattern having the same Baume degree of a ferric chloride solution used as a corrosive liquid, an optical transmission density of two gradations of black and white, and a gravure screen provided. 1 to 2 degrees higher than the value obtained when the original film was baked to reduce the penetration of ferric chloride from the gaps around the resist pattern, which occurs with the progress of corrosion, and the resist film Disclosed is a method for preventing peeling off from the sheet.

Hereinafter, the present invention will be described step by step. (1) A step of producing an original film. Simply photographing the woodgrain board yields only a film of conduit grooves with two levels of optical density, black and white, which can be used to express the continuous depth of the natural woodgrain conduit grooves even when gravure engraving is performed. Can not do it. For this reason, it is necessary to perform a process for continuously changing the optical transmission density so as to correspond to the conduit groove of the woodgrainboard. Such processing methods include:
For example, a method in which two types of intermediate films described later are shifted and photographed, a method in which a white paint is sprayed on a wood grain board dyed with a dark paint, and a method in which a colored transparent resin is used can be exemplified.

The woodgrain used is preferably one in which the conduit grooves can be clearly seen when sawn. Such woods include, for example, zelkova, oak, lauan and the like. In addition, the conduit groove here is a cross section, an inclined cross section, or a vertical cross section of a conduit generated when lumber is turned into wood, and refers to a portion that appears to be recessed in an elongated groove shape running in the fiber direction of the wood. .

The original film may be either a negative image or a positive image, and the photosensitive emulsion and the base film used for the film may be:
There is no particular limitation as long as each is transparent. (2) Baking process The photosensitive resist to be used is determined according to the original film. In other words, if the original film is a negative image, a method of transferring the exposed resist film to a plate material using a negative resist which causes a crosslinking reaction and a polymerization reaction by exposure to light and becomes insoluble in a solvent is adopted, and the original film is a positive image. If so, a method of using a positive resist which becomes soluble in a solvent upon exposure to light and directly exposing the resist film formed on the surface of the plate material to that is adopted.

As the properties of the resist, those having a property that the degree of reaction H (hardening or softening) sharply increases from a certain exposure density d (= light intensity I × exposure time t) are preferable. As other conditions, the photosensitive wavelength, transferability to the plate material, development dissolution permeability, non-corrosiveness to the corrosive liquid, excellent balance of the permeation rate of the corrosive liquid in the resist film thickness direction, etc. are excellent. Desired. Considering these conditions, it is preferable to use dichromated gelatin as the negative resist.

As the base film for temporarily indicating the resist, a resin film such as polyethylene terephthalate used for a so-called auto film can be used in addition to a varnish paper used for a so-called carbon tissue. When importance is placed on the reproducibility of the natural wood channel, it is preferable to perform printing without using a gravure screen used for ordinary gravure plate making for the reasons described above.

The amount of exposure at the time of printing may be the same as that of normal gravure printing. However, when printing is performed without using a gravure screen, the amount of exposure is set higher than usual, and the same conduit groove pattern is exposed to the optical transmission density. Is preferably 130% to 150% of the value obtained when an original film provided with a gravure screen is printed. Here, setting the optical transmission density to two gradations of black and white means that, in the process of producing the original film, a process is performed in which the depth of the wood grain conduit groove does not correspond to the optical transmission density of the original film. Means taking a picture of the wood grain conduit as it is. Here, white means a state where the optical density of the original film is the lowest (close to 0), and black means a state where the optical density of the original film is the maximum.

As a light source used for printing, a light source that emits ultraviolet light or visible light such as a carbon arc lamp or a mercury lamp can be used. (3) Transfer Step The transfer of the resist film is performed after baking for a negative resist, and before baking for a positive resist.
The method of transferring may be a method used for ordinary gravure plate making, for example, when a negative resist is used, imparts moisture to the resist to give tackiness to uncured gelatin,
It can be transferred to a plate material by close contact pressure. Also, the plate material used at this time may be one used for normal gravure plate making, for example, a copper plate, an iron plate,
A cylindrical plate can be used. In addition, only in the case of a positive resist, since it is formed directly on the plate material surface,
Instead of the above transfer method, a resist may be directly applied and formed.

(4) Developing Step The developing may be performed in accordance with a usual gravure plate making method, and the uncured portion of the resist and the base film may be removed using hot water or the like. (5) Corrosion Step Corrosion can also be performed by applying a corrosive liquid to a plate material via a resist film in the same manner as in a normal gravure plate making method. Corrosion liquid can be appropriately determined according to the properties of the resist or metal plate material, but when using dichromated gelatin as the resist and copper or iron as the plate material, use a ferric chloride solution Is preferred. The concentration of the ferric chloride solution may be the concentration and time used for normal gravure plate making, but if a gravure screen is not used, there is a problem of exfoliation of the resist film as described above. It is preferable to use a ferric chloride solution having a conduit groove pattern having an optical transmission density of two gradations of black and white and a Baume degree of 1 to 2 times higher than a value obtained when printing an original film provided with a gravure screen. In addition, when the concentration of ferric chloride in the corrosion liquid increases,
Since the water content is relatively small, the permeation speed of the etchant through the resist film is reduced. In order to compensate for this, the corrosion time is usually set to 130% to 140% of the value obtained when the original channel film having the same conduit groove pattern and the optical transmission density is set to two gradations of black and white and a master film provided with a gravure screen is printed. Preferably, it is extended.

The corrosion of the plate material is controlled mainly by the thickness of the resist film. In other words, it takes a long time for the corrosion liquid to reach the plate material surface in a thick portion of the resist film, so that the corrosion time is relatively short, while a thin portion of the resist film has a long time to reach the plate material surface. Since the length is short, the corrosion time becomes long, and as a result, the corrosion proceeds according to the thickness of the resist film. Therefore, irregularities corresponding to the thickness of the resist film can be formed on the plate material without using any special method.However, according to normal gravure plate making, several types of ferric chloride solutions having different Baume degrees are used. Are preferably applied in descending order of the Baume degree.

(6) Step of Forming Metal Coating As the metal used for forming the coating, it is preferable to use chromium or the like which is excellent in abrasion resistance and chemical resistance. The method of coating the metal plate material with chromium can be performed by electroplating according to a usual method. In addition, it is also possible to perform a matte roughening treatment by sandblasting or the like prior to the metal coating.

[0020]

The operation of the above arrangement in the case where a negative master film is used will be described below. An image of a negative master film having an optical transmission density corresponding to the continuous shallowness of the conduit groove and having a lower density at a deeper position is printed on a photosensitive negative resist film. Thereby, the curing depth of the resist film is
It becomes smaller in proportion to the optical transmission density of the negative master film. In other words, curing progresses to a portion having a low optical transmission density to a portion deeper than the surface on the light source side, and a portion having a high optical transmission density progresses to a portion shallower than the surface on the light source side.
Since the uncured portion in the resist film is removed during the development process, the thickness of the resist film has a thickness that continuously corresponds to the optical transmission density of the original film. Next, according to the above-mentioned method, the ferric chloride solution is allowed to act on the resist film in order from the high concentration. Regardless of the concentration of the etchant, the thinner part of the resist film reaches the plate surface earlier and the thicker part arrives later, so the corrosion time is determined according to the thickness of the film. By using this, the difference in the corrosion time with respect to the film thickness can be made larger. This is because the high concentration of the etchant cannot pass through the thick portion of the resist film, so that the difference in the timing of starting the corrosion between the thick portion and the thin portion of the resist film is further increased. Such a difference in the corrosion time due to the thickness of the resist film becomes a difference in the corrosion depth as it is, and this difference results in the formation of irregularities on the plate material surface.

In this way, the continuous depth of the conduit groove is converted into the optical transmission density of the original film and the thickness of the resist film in order, and finally corresponds to the unevenness of the plate material. .

[0022]

[Example] Continuous depth of conduit groove corresponds to optical transmission density
The following three methods are used to correspond to the negative
There is a method. (1) Using a wood grain board as a black and white two-tone image by the usual method
Take a picture to obtain a negative intermediate film 1 and a positive intermediate film 2.
You. These are referred to as positive intermediate film 2 as shown in FIG.
垂直 x_V1At a distance, horizontally in a conduit
Δx in groove direction_HShift to the shallower depth
Place the LUM1. More vertical than the negative intermediate film 1
Δx downward_V2And another photosensitive film 3 is placed
And printing is performed. Positive image intermediate film 2 and negative image intermediate film
The light transmitted through the film 1 is a positive intermediate filter as shown in FIG.
As a result, the light that has passed through the
The film 3 has a conduit running direction and a width direction orthogonal thereto.
With a concentration distribution in which the optical transmission density changes continuously
An image of the groove is exposed. Photosensitive film 3 in FIG.
In the case of a negative image, A has the highest optical transmission density,
It becomes thin continuously in the order of B, C, D, E, and A, B,
Even within the ranges of C, D and E, Δx_V1, Δx _V2, Δx
_HThe optical transmission density changes continuously depending on the value of. This
The image of the photosensitive film 3 photographed as in
The deeper the image, the higher the optical transmission density
The film's optical transmission density.
Thus, a negative film is obtained. (2) The conduit groove of the natural wood grain board is as shown in Fig. 2-4.
A continuous slope from the shallowest part 5 toward the deepest part 6 of the conduit groove
It is getting deeper. Wood grain board surface including this conduit groove 4
Dye (black, blue, green, red, etc.)
To color. As a result, a dark paint layer 7 is formed on the entire surface of the woodgrain plate.
Is done. Next, from the direction of the arrow, that is, the diagonal direction,
Spray system paint. Formed by sprayed paint
The white paint layer 8 has a thick layer on the non-conduit groove portion of the woodgrain board surface.
Is formed in the conduit groove 4 from the shallowest part 5 of the conduit groove.
The thickness of the layer becomes thinner toward the deepest part 6 of the groove. This result tree
The optical reflection density of the eye channel groove is higher in the deeper part and lower in the shallower part.
When this is taken, the depth distribution of the natural conduit groove is optically transparent.
A film similar to that converted to overdensity is obtained. (3) As shown in Fig. 3, colored transparent resin is applied to the woodgrainboard, for example.
For example, solvent drying, heating, chemical reaction with curing agent, or UV
Silicone resin, acrylic resin, etc. that are cured by radiation etc.
A small amount of pigment or dye such as phthalocyanine blue
Pour the added liquid composition, dry and cure, release
The mold of the colored transparent resin with the channel groove and the unevenness reversed by doing
A film 9 is obtained. This mold film 9 is used as a photosensitive film.
Place it on the camera 3 and irradiate it with light.
Where the film thickness is thin, the exposure amount is large, and where it is thick, the exposure amount is small.
The depth of the conduit groove was converted to optical transmission density.
Obtain a plate film.

In addition to these methods, a black and white two-tone conduit image is scanned by a scanner and converted into a digital signal, which is converted into a continuous density image using digital image processing, and is then transferred to a photosensitive film by a scanner. It is also possible to output. The negative master plate film 10 obtained by any of the above methods is superposed on the photosensitive negative resist film 11 as shown in FIG. 4 and is baked using ultraviolet light or visible light. The negative resist film 11 is originally soluble in a solvent, but hardens by light to become insoluble. Since this photochemical reaction occurs in proportion to the amount of exposure, the portion having a low optical transmission density cures to a portion deeper than the light source side,
In a portion having a high optical transmission density, curing occurs only to a portion shallower than the light source side. The exposure amount at this time is 130% to 130% of the value in the case of ordinary gravure plate making, that is, when the same conduit groove pattern is made to have an optical transmission density of two gradations of black and white and an original film provided with a gravure screen is printed. For example, in the case of the present invention, the exposure time is set to 390 sec in the case where the exposure of the resist film of the mercury lamp is 26000 lux and the exposure is 270 sec in the normal case. As a result, the strength of the resist film is increased, and the swollen resist film is less likely to be broken and peeled by the liquid flow due to the moisture in the corrosion liquid.

As shown in FIG. 5, the photosensitive negative type resist film 11 after the baking is placed on the opposite side of the base sheet 11c downward, and is pressed tightly while applying moisture to the separately prepared plate material 12. Transcribe. The moisture makes the gelatin film contained in the uncured portion 11b in the photosensitive negative resist film sticky, and makes the resist film 11 and the plate material 12 adhere to each other. Developing the plate material 12 on which the photosensitive negative resist film 11 was transferred to 35-
Perform by immersing in a hot water pad at 45 ° C. Undeveloped gelatin melts out of the periphery of the resist film by the development treatment, and the base film is peeled off from the resist film.
Only remain. As a result, a resist film having a thickness corresponding to the optical transmission density of the negative master plate film is formed on the plate material. After development, thoroughly wash the surface of this resist with water,
Finally, about 85% of alcohol is sprinkled to remove water in the resist evenly and dried well, so that each part of the resist film retains uniform water.

Next, the plate material 12 is corroded with a corrosive liquid. Prior to this, a liquid obtained by dissolving asphalt with benzol is applied to the periphery and unnecessary portions of the plate to prevent corrosion. As a corrosion liquid, a ferric chloride solution was used, and the concentration was the same conduit groove pattern and the optical transmission density was set to two gradations of black and white,
In addition, a film having a Baume degree of 1 to 2 times higher than the value obtained when printing an original film provided with a gravure screen is used. For example, when the normal Baume degree is 39 degrees, in the present invention, 40.5
Degree. First, apply the solution with the highest Baume degree,
The solution having the lowest concentration is applied in order, and the solution having the lowest Baume degree is applied last. By such an operation, the corrosion is first started in the thinnest resist film in FIG. 6A, followed by b and c, and the corrosion is started last in d.
The earlier the onset of corrosion, the longer the corrosion time and the greater the depth of corrosion. Therefore, the height of the plate after the completion of the corrosion decreases in the order of d, c, b, and a as shown in FIG. Such unevenness of the plate material 12 is obtained by reversing the unevenness of the wood grain conduit groove. Further, the corrosion time is set to 130% to 140% of the time normally used for the above-mentioned reason. For example, if the normal corrosion time is 270 seconds, it is set to 390 seconds in the case of the present invention.

After the plate material has been completely corroded, the plate surface is thoroughly cleaned, and a sword is used to correct scratches and other parts. Thereafter, the surface is subjected to a matte surface roughening treatment using sand blast, and finally, chromium electroplating is performed in order to improve abrasion resistance and chemical resistance of the surface. The embossing plate of the present invention can be used for normal embossing in which a thermoplastic resin such as polyvinyl chloride is heated and softened, and the embossing plate is pressed to form irregularities in the conduit groove. A UV or electron beam curable resin coating is applied to the surface of a roll plate as described in the publication, and after backing and laminating the base sheet via the coating, the coating is cured with UV or electron beam to form the plate unevenness. The embossing plate of the present invention can also be used in an embossing method of shaping and then releasing the base sheet and the shaped hardened paint adhered and laminated on the base sheet.

[0027]

According to the present invention, an embossing plate capable of faithfully reproducing the shape of the wood-grained board groove and its continuous depth can be manufactured at a lower cost and a simpler method than the conventional method such as the molding electroforming method. Plate making can be performed by a manufacturing method.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method for producing an original film using an intermediate film.

FIG. 2 is a diagram showing a method for preparing an original film using a white paint.

FIG. 3 is a diagram showing a method for producing an original film using a colored transparent resin.

FIG. 4 is a view showing a step of printing on a photosensitive negative resist film.

FIG. 5 is a view showing a step of transferring a photosensitive negative resist film to a plate material.

FIG. 6 is a view showing a step of corroding a plate material.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Kenzo Eya 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (72) Sachiko Shima 1-1-1, Ichigaga-cho, Shinjuku-ku, Tokyo No. 1 Inside Dai Nippon Printing Co., Ltd. (56) References JP-A-3-13944 (JP, A) JP-A-62-1291662 (JP, A) JP-A-5-247670 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03F 7/00 G03F 1/02 B29C 59/02

Claims (7)

(57) [Claims] (1) A negative master plate film of a woodgrain board is prepared by converting the continuous depth of a conduit groove into an optical transmission density so that the optical transmission density becomes lower as the depth of the conduit groove on the woodgrain board surface becomes lower. Process. (2) a step of baking the negative master film on a photosensitive negative resist film; (3) a step of transferring the resist film onto a metal plate material surface. (4) A step of removing unexposed portions of the resist film transferred onto the plate material by a development process. (5) A step of causing the etching liquid to act on the plate material from above the resist film, and performing corrosion so that the thinner the resist film, the greater the corrosion depth of the plate material, and the thicker the portion, the smaller the corrosion depth. A method for making a wood grain conduit groove embossing plate, characterized by performing the above steps in this order. (1) A positive master plate film of a woodgrain board is produced by converting the continuous depth of the conduit groove into an optical transmission density such that the optical transmission density becomes higher as the depth of the conduit groove on the woodgrain board surface becomes higher. Process. (2) A step of transferring the photosensitive positive resist film onto the surface of a metal plate material. (3) A step of baking the positive master film on the resist film transferred onto the plate material. (4) a step of removing unexposed portions of the resist film by a development process; (5) A step of causing the etching liquid to act on the plate material from above the resist film, and performing corrosion so that the thinner the resist film, the greater the corrosion depth of the plate material, and the thicker the portion, the smaller the corrosion depth. A method for making a wood grain conduit groove embossing plate, characterized by performing the above steps in this order. 3. The method according to claim 1, further comprising the step of forming a metal film having higher abrasion resistance and / or chemical resistance than the plate material on the surface of the plate material after the completion of the corrosion. The plate making method of the wood grain conduit groove embossing plate described. 4. After the completion of the corrosion, the surface of the plate material is subjected to a matte surface roughening treatment, and further a step of forming a metal film having higher abrasion resistance and / or chemical resistance than the plate material is provided. The plate making method of a wood grain channel embossing plate according to claim 1 or 2, characterized in that: 5. A method according to claim 1, wherein a gravure screen is not used when baking the original film on the photosensitive resist film. 6. A conduit groove pattern having the same exposure amount at the time of baking an original film on a photosensitive resist film is subjected to an optical transmission density of 2 black and white.
6. The method according to claim 5, wherein the value is 130% to 150% of the value obtained when the original film having a gradation and a gravure screen is baked. 7. The value obtained by printing the same groove groove pattern with the same corrosive liquid at the optical transmission density of two gradations of black and white and the baking of an original film provided with a gravure screen.
The plate making method of a wood grain channel groove embossing plate according to claim 5 or 6, wherein the ferric chloride solution has a value of about 2 times higher.