JPH0781030A - Form plate sheet for laser platemaking - Google Patents

Abstract

PURPOSE:To obtain a form plate sheet for laser platemaking wherein perforation sensitivity can be increased and, further, solvent resistance and hardness in dots can be enhanced. CONSTITUTION:A form plate sheet for laser platemaking has a first cured resin layer 1 and a second cured resin layer 2 provided in order on a base material 3, and the first cured resin layer 1 and the second cured resin layer 2 comprise a cured composition which contains a curing agent and resin having a hydroxyl group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser engraving plate sheet suitable for application to, for example, an electronic gravure plate sheet.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As a plate sheet for electronic gravure, one having a carbon-containing resin layer on a substrate has been proposed (for example, Japanese Patent Application No. 5-176683). In this electronic gravure plate sheet, the first layer (lower layer) of the carbon-containing resin layer was in an uncured state in order to enhance the sensitivity of laser plate making. However, in this case, when a dot is formed, alcohol solvent in the ink enters the uncured dot and swells or dissolves in the dot, resulting in durability of the dot and transfer of the ink to paper. The printing durability of the plate sheet and the quality of the printed matter were deteriorated due to the deterioration of the printing property.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a plate plate for laser plate making which is capable of enhancing perforation sensitivity and solvent resistance and hardness in dots. .

On the other hand, the electronic gravure plate sheet composed of a two-layer type resin layer has drawbacks that the manufacturing process becomes more complicated and the cost becomes higher.

The present invention has been made in view of the above problems, has a simple manufacturing process, is inexpensive in manufacturing cost, and is capable of increasing solvent resistance and hardness in a dot and for laser plate making. The purpose is to obtain a plate sheet.

[0006]

In the plate sheet for laser plate making of the present invention, a first cured resin layer 1 and a second cured resin layer 2 are sequentially provided on a substrate 3 as shown in FIG. 1, for example. It is a thing.

In the laser plate making sheet of the present invention, the first cured resin layer 1 and the second cured resin layer 2 are obtained by curing a composition containing a curing agent and a resin having a hydroxyl group. Is a plate sheet for laser plate making having the above-mentioned constitution.

Further, in the plate plate for laser plate making of the present invention, the amount of the curing agent with respect to the resin having hydroxyl groups in the first cured resin layer 1 is 0.2% by weight or more, and the second cured resin. It is the plate plate for laser plate making of the said structure which is below the quantity of the hardening | curing agent with respect to the resin which has the hydroxyl group of layer 2.

The laser plate-making plate sheet of the present invention is a laser plate-making plate sheet having a cured resin layer on a substrate, wherein the cured resin layer contains a curing agent and a resin having a hydroxyl group. In addition, it is obtained by curing a composition in which the amount of the curing agent with respect to the resin having a hydroxyl group is 5% by weight or more.

According to the plate plate for laser plate making of the present invention, the first cured resin layer 1 and the second cured resin layer 2 are sequentially provided on the base material 3, and the first cured resin layer 1 and the second cured resin layer 2 are cured. The resin layer 2
By using a composition obtained by curing a composition containing a curing agent and a resin having a hydroxyl group, it is possible to increase the perforation sensitivity and the solvent resistance and hardness in the dots.

Further, according to the plate plate for laser plate making of the present invention, in the plate plate for laser plate making having a cured resin layer on a substrate, the cured resin layer comprises a curing agent and a resin having a hydroxyl group. By including a cured composition containing 5% by weight or more of the curing agent based on the resin having a hydroxyl group, the manufacturing process is simple, and the manufacturing cost is low. The solvent resistance and hardness in the dots can be increased.

[0011]

EXAMPLE An example of the laser plate making sheet of the present invention will be described below with reference to FIG.

First, carbon black having the composition shown in Table 1 was dispersed with a sand grinder. For the first layer, the addition amount of melamine resin was 0%, 1%, 3%,
Six types were manufactured by changing the amount to 5%, 10% and 20%. In addition, the second layer contains 20% melamine resin.
Only the one of% was produced. Here, the addition amount of the melamine resin represents weight% with respect to the total amount of polyester and nitrocellulose.

[0013]

[Table 1]

Next, a 188 μm PET film was coated with the above-prepared carbon-containing polymer solution,
A two-layer type resin layer containing carbon was formed as shown in FIG. Here, the manufacturing conditions are as follows. Coating thickness First layer: 20 to 21 μm Second layer: 5 to 6 μm Drying conditions Drying at 80 ° C. for 3 minutes and further drying at 100 ° C. for 3 minutes Curing conditions 130 ° C. for 8 minutes

Next, the composition as shown in Table 2 was used.
Bonblack was dispersed with a sand grinder.
Addition amount of melamine resin is 0%, 1%, 3%, 5%, 10
% And 20% are the same as those in Table 1, but other than this, 0.2%, 0.4%, 0.6%, 0.8%
The composition of was also prepared.

[0016]

[Table 2]

Next, a 188 μm PET film was coated with a carbon-containing polymer solution to form a one-layer type carbon-containing resin layer.

Here, the conditions are as follows. Coating thickness: 20 μm Drying conditions: Dry at 80 ° C for 3 minutes and then at 100 ° C for 3 minutes.
Drying for minutes Curing conditions: 130 ° C for 8 minutes

Next, the relationship between the amount of melamine resin added and the sensitivity was investigated. That is, a 60 μm square dot was produced with a semiconductor laser having an output of 1 W on the two-layer type resin layer produced above, and the perforation depth was measured.

The dot depth was measured by the following method. A laser microscope was used. Width 6 mm x length 8 cm
2 stripes were prepared, and the depths of the holes at 3 locations / stripe × 2 stripes = 6 locations were measured. The measurement results are shown in Table 3, and the value in Table 3 is the average value of 6 data. From the results in Table 3, it can be seen that the greater the amount of melamine resin added, that is, the smaller the perforation depth as the crosslinking reaction proceeds, and the lower the sensitivity. here,
The perforation depth is preferably 10 μm or more. Therefore, as can be seen from Table 3, the amount of melamine resin added is 0%.
In the range of up to 20.0%, sufficient perforation depth was obtained.

[0021]

[Table 3]

Next, the relationship between the added amount of the melamine resin and the solvent resistance and the relationship between the added amount of the melamine resin and the pencil hardness were investigated. That is, the surface of the resin layer is treated with ethanol, methanol,
Wiping was performed with IPA or the like to examine the added amount of the melamine resin and the solvent resistance (alcohol resistance), and the relationship between the added amount of the melamine resin and the pencil hardness. Table 4 shows the measurement results.
As shown in.

The solvent resistance is determined by wiping the surface of the resin layer with ethanol, methanol, or IPA, and if the surface has uneven gloss or peeling, it is NG, and if not, OK.
And The pencil hardness was measured according to JIS K5400.

From the results shown in Table 4, even when the amount of melamine resin added was as small as 0.2%, alcohol resistance was satisfactory and pencil hardness of 2H or higher was obtained. Also,
Satisfactory results were obtained even when the addition amount was more than this, that is, in the range of 0.4 to 20%.

[0025]

[Table 4]

From the above, according to this example, the perforation sensitivity can be increased by making the addition amount of the melamine resin in the first layer smaller than that in the second layer. Further, the solvent resistance in the dots is increased, and the hardness is also increased, so that the printing durability is improved. Further, as the plate making speed is increased, a sheet having a high perforation sensitivity is required, and in such a case, the method according to the present invention can meet the requirement.

Next, other examples of the plate sheet for laser plate making of the present invention will be described. Here, a study was made on one having a one-layer type cured resin layer. The composition of the cured resin layer and the production conditions were the same as those in the above-mentioned examples.

The relationship between the amount of melamine resin added and the depth of perforation was examined for the one-layer type cured resin layer thus produced. In addition, the presence or absence of distortion in the dot shape at this time was also examined. The irradiation conditions of the semiconductor laser when forming dots and the method of measuring the dot depth were the same as in the above-mentioned embodiment. Further, the presence or absence of the distortion of the dot shape was observed by a microscope.

Table 5 shows the measurement results of the perforation depth when the addition amount of the melamine resin was changed. The vertical column on the left side shows the amount of melamine resin added (%). The middle row is the measurement result of the one-layer type resin layer. Here, the perforation depth is 25.6 μm when the melamine resin addition amount is 0%, whereas the perforation depth becomes shallower as the melamine resin addition amount is increased. However, since it is practically desirable that the perforation depth is 10 μm or more, a sufficient perforation depth is obtained when the amount of the melamine resin added is 0 to 20%.

[0030]

[Table 5]

The column on the right side shows the measurement results of the two-layer type resin layer, which is the same as the result of the above-mentioned embodiment. That is, it is shown for comparison with the measurement results of the one-layer type resin layer, but the perforation depth of the one-layer type resin layer is larger than that of the two-layer type resin layer by addition of the melamine resin. If the amount is the same, it is recognized that it is slightly smaller.

The results of observing the dot shape when the amount of melamine resin added was changed are shown in Table 6. Here, the middle row shows the melamine resin addition amount (%). The bottom row shows the observation results of the dot shape with symbols. Here, X indicates that the dot shape is distorted, Δ indicates that the dot shape is slightly distorted, and ○.
Indicates that there is no distortion in the dot shape. As can be seen from the results in the table, distortion was observed in the dot shape in the range where the melamine resin addition amount was 0 to 1.0%. Further, when the amount of melamine resin added was 3.0%, some distortion was observed. On the other hand, no strain was observed when the amount of melamine added was in the range of 5.0 to 20.0%.

[0033]

[Table 6]

As described above, from the measurement result of the perforation depth and the observation result of the dot shape, in the one-layer type resin layer, if the addition amount of the melamine resin is within the range of 5.0 to 20.0%. It was confirmed that a resin layer sufficient for practical use could be obtained. On the other hand, regarding the solvent resistance and the pencil hardness, since the results of the above-described examples can be used as they are, satisfactory results can be obtained when the melamine resin addition amount is within the range of 5.0 to 20.0%. Recognize.

From the above, according to this example, by adjusting the addition amount of the melamine resin even in the one-layer type resin layer, the manufacturing process is simple and the cost is low, and it is practically sufficient. It is possible to obtain various perforation depths, enhance solvent resistance in dots, and enhance hardness, and improve printing durability. Further, as the plate making speed is increased, a sheet having a high perforation sensitivity is required, and in such a case, the method according to the present invention can meet the requirement.

The one-layer type resin layer is similar to the two-layer type resin layer in that the thickness of the first and second layers, the oil absorption of carbon black, the content of carbon black, etc. The limitation is that the control of drilling sensitivity is limited because it cannot be changed. In addition, since the one-layer type resin layer optimizes the dot shape and maintains the hardness while maintaining the sensitivity, the oil absorption of carbon black and the carbon black of the carbon black are the same as those of the two-layer type resin layer. Content,
Alternatively, it is difficult to satisfy the both by changing the amount of melamine resin.

On the other hand, the two-layer type resin layer has a merit that the manufacturing process becomes complicated, whereas the one-layer type resin layer can be manufactured at a lower cost.

Therefore, in terms of sensitivity, the one-layer type resin layer is slightly lower than the two-layer type resin layer, but since it is at the same level, the sensitivity is remarkably high, and the dot shape and hardness are also high. If you want something that satisfies your needs, use the two-layer type, and if you want to make a cheap one with a dot shape and hardness that is at a practical level and sensitivity, then use the one-layer type. It is possible to flexibly meet the demands of.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0040]

As described above, according to the present invention,
By making the addition amount of the melamine resin in the first layer smaller than that in the second layer, the perforation sensitivity can be increased. Further, the solvent resistance in the dots is increased, and the hardness is also increased, so that the printing durability is improved. Further, it is possible to produce a sheet having a high perforation sensitivity, which is required as the plate making speed increases.

Further, according to the present invention, it is possible to obtain a practically sufficient perforation depth with a simple manufacturing process and at low cost, and also to improve the solvent resistance in the dot and the hardness. The printing durability can be improved.

[Brief description of drawings]

FIG. 1 is a constitutional view showing an example of a plate sheet for laser plate making of the present invention.

[Explanation of symbols]

 1 1st layer 2 2nd layer 3 Base material

Claims (4)

[Claims] 1. A plate plate for laser plate making, comprising a base material on which a first cured resin layer and a second cured resin layer are sequentially provided. 2. The first cured resin layer and the second cured resin layer are formed by curing a composition containing a curing agent and a resin having a hydroxyl group. Laser printing plate sheet. 3. The amount of the curing agent with respect to the resin having a hydroxyl group in the first cured resin layer is 0.2% by weight or more, and the amount of the curing agent with respect to the resin having a hydroxyl group in the second cured resin layer. The plate sheet for laser plate making according to claim 2, wherein: 4. A laser prepress plate sheet having a cured resin layer provided on a substrate, wherein the cured resin layer comprises a curing agent,
A laser plate-making plate sheet, comprising a resin having a hydroxyl group and comprising a cured composition containing 5% by weight or more of the curing agent based on the resin having a hydroxyl group.