JP2977014B2 - Method for producing printing blanket and vulcanized paper used in the method - 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 for producing a printing blanket used in an offset printing machine and a vulcanized paper used in the method, and more particularly, to preventing adhesion between a surface rubber and a vulcanized paper. The present invention relates to a method for producing a printing blanket that does not require talc, and a vulcanized paper used in the method.

[0002]

2. Description of the Related Art In offset printing, an image is transferred from a printing plate to a blanket once, and the image transferred to the blanket is printed on paper. As a printing blanket used for high-speed offset printing, a compressible blanket provided with a compressible layer and an incompressible blanket provided with no compressible layer are used. In the production of any printing blanket, when applying the surface rubber layer and winding it,
To prevent sticking, powder talc on the surface rubber layer,
A vulcanized paper is laminated thereon and wound up. In other words, after applying the surface rubber layer, when winding it on a roll for vulcanization, in order to obtain the thickness accuracy of the surface rubber layer, and to suppress foaming of the surface rubber layer due to gas generated during vulcanization. To
The vulcanized paper is wound under tension while sandwiching it. However, if the vulcanized paper is directly laminated on the surface rubber layer, the vulcanized paper will not peel off after vulcanization, so talc is dusted on the surface rubber layer to prevent adhesion, and the vulcanized paper is laminated on it. It is wound up.

A conventional method of manufacturing a compressible printing blanket will be described with reference to FIG. 2. The compressible printing blanket is formed by applying a rubber paste to a cotton cloth, rayon cloth or the like.
The compressible layer 3 is provided on the support 2 laminated in three layers, and the support 4 made of cotton cloth is laminated on the compressible layer 3 to form the intermediate laminate 5. Next, an oil-resistant surface rubber layer 6 serving as a printing surface is applied to the intermediate laminate 5. For laminating the surface rubber layer 6, the surface rubber layer 6 is applied by a coating device 7 such as a knife coater, and then the talc 8 is powdered on the surface rubber layer to perform an anti-adhesion treatment. The paper is wound around the roll 10 with tension applied while sandwiching the paper.

[0004] Then, it is vulcanized in a dry heat vulcanizing can 11 while being wound on a roll 10. The vulcanization conditions are determined by the size of the roll winding, and are usually 135 ° C to 150 ° C.
Vulcanization at about 10 hours for about 10 hours is common. When the vulcanization is completed, the vulcanized paper 9 is removed and the surface rubber layer 6 is polished.
In order to remove the vulcanized paper 9, the vulcanized paper 9 may be removed while rewinding. At this time, since the talc 8 is powdered between the surface rubber layer 6 and the vulcanized paper 9, the vulcanized paper 9 can be peeled off smoothly. After the vulcanized paper 9 is peeled off, the surface rubber layer is polished by a polishing machine such as a sandpaper grinder, and the surface is formed into a fine uneven surface having a predetermined roughness. This surface roughness is usually formed with a 10-point average roughness of 2 to 5 μm using a stylus type roughness meter.

[0005]

As described above, in the conventional blanket manufacturing method, the surface rubber layer 6 and the vulcanized paper 9
Since talc 8 is used to prevent adhesion between the two, there are the following problems. That is, when powdering talc 8,
When the vulcanized paper 9 is peeled off from the surface rubber layer 6 while being rewound, dust is generated, thereby deteriorating environmental hygiene. Further, since the production equipment is heavily soiled, frequent cleaning is required to protect environmental hygiene and maintain product quality. For this reason, there is a problem that not only the working environment is deteriorated but also the working efficiency is reduced and the cost is increased in terms of cost.

When the amount of powdered talc 8 on the surface rubber layer 6 decreases, the vulcanized paper 9 adheres to the surface rubber layer 6 and hardly peels off. It is set to be large considering this. The powdered talc 8 not only adheres to the surface of the surface rubber layer 6 but also
When the amount of powdered talc 8 increases, the amount of talc buried in the surface rubber layer 6 increases accordingly. If talc is left on the printing surface, the ink transfer property is impaired. Therefore, polishing must be performed so that talc does not remain on the printing surface. However, if the amount of talc buried in the surface rubber layer 6 increases, the polishing allowance must be increased accordingly. Must. In order to secure a surface rubber layer having a predetermined thickness after polishing and to increase the polishing allowance, it is necessary to increase the coating thickness of the surface rubber layer before polishing. If the coating thickness is increased, not only does it take extra time to apply it, but it also takes extra polishing time,
Naturally, the cost increases.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and enables the vulcanized paper to be peeled off after vulcanization without using talc, thereby preserving the working environment and reducing the cost of products. An object of the present invention is to provide a method for producing a printing blanket that can be used and vulcanized paper used in the method.

[0008]

The present invention has the following configuration to achieve the above object. That is, as a method for producing a printing blanket, a step of providing a surface rubber layer serving as a printing surface on at least one layer of a support, and a step of directly providing the surface rubber layer with a surface pH of 6.0 or more on the surface rubber layer To
A step of bringing the vulcanized paper formed by release treatment into close contact and winding it up,
Vulcanizing by heating means, removing the vulcanized paper,
A polishing step of finishing the surface of the surface rubber layer. The release treatment of the base paper is performed by applying 0.1% to the surface of the base paper.
2 g / m ² or more of fluorinated resin or silicone compound
It is preferable to perform this by providing a layer of an object. Also,
The vulcanized paper used in the above-mentioned production method has a surface p
H is not less than 6.0, and at least one surface of the base paper has
0.2 g / m ² or more of fluororesin or silicone
It is provided with a compound layer.

[0009] In the production method according to the present invention, after the surface rubber layer is applied, the vulcanized paper is directly wound in close contact with the talc without powdering, and then the wound roll is vulcanized. As the vulcanized paper, wood pulp is formed to facilitate peeling after vulcanization without powdering the talc on the base paper surface, and at least one surface of the base paper is 0.2 mm.
A layer is provided by applying or impregnating a coating liquid of a fluorine-based resin or a silicone-based compound of g / m ² or more. The coating or impregnating of a coating solution of a fluororesin or a silicone compound to provide a layer of 0.2 g / m ² or more prevents adhesion between the vulcanized paper and the surface rubber layer after vulcanization, This is because the peeling is smooth, and if it is less than 0.2 g / m ² , the peeling becomes heavy and the vulcanized paper is damaged.

As the wood pulp used in the present invention, pulp obtained by chemically and / or mechanically treating plant materials such as conifers and hardwoods can be used alone or in combination, and is particularly limited. Not something. In addition, as additives to be added to the pulp slurry, additives usually used in papermaking, for example, fillers, sizing agents, paper strength agents, retention agents, defoamers, slime control agents,
There are drainage improvers and the like, and these additives can be contained as needed.

As the filler, heavy calcium carbonate, light calcium carbonate, kaolin, clay, satin white,
Titanium oxide, talc, and the like can be given, and use of these fillers in combination is no problem. Typical examples of the sizing agent include, but are not limited to, an alkyl ketene dimer sizing agent, an alkenyl succinic anhydride sizing agent, and a neutral rosin sizing agent.

Here, in order to maintain the paper strength of the base paper after the dry heat vulcanization can treatment, the paper surface pH is preferably set to 6 or more. The reason for setting the paper surface pH to 6 or more is that when the paper surface pH is in an acidic region (acid paper), the paper fibers collapse (thermal degradation of the fibers) due to the acid under high temperature conditions in the vulcanization step. is there. As a method of adjusting the paper surface pH, there is a method of adding a sulfuric acid band, caustic soda, a sizing agent, calcium carbonate, and the like to a pulp slurry.

Examples of the fluorine-based resin include perfluoroalkyl phosphate, polytetrafluoroethylene and the like. Examples of the silicone compound include polydimethylsiloxane, dimethylsiloxane and methylvinylsiloxane copolymer, and dimethylsiloxane and methylhexenylsiloxane copolymer.

The amount of coating on the base paper surface is preferably 0.2 g / m ² or more for the purpose of preventing adhesion between the surface rubber layer after vulcanization and the vulcanized paper and smoothly removing the vulcanized paper. Means for providing the layer include size press impregnation, coating with a coater machine or a gate roll. Further, by using oxidized starch, polyvinyl alcohol, CMC, sodium alginate or the like in combination with the fluororesin used here, the vulcanized paper can be more smoothly separated.

Next, a method of manufacturing a printing blanket will be described with reference to FIG. FIG. 1 is a process chart showing a blanket manufacturing method according to the present invention. First, a blanket having a known structure is manufactured. For example, as shown in FIG. 1, a rubber cement to create a support 12 which is laminated to adhesive pull to two layers cotton cloth, a compressible layer 13 formed thereon, further, on the compressible layer 13 The intermediate laminate 15 is formed by laminating the supports 14 made of cotton cloth. Next, an oil-resistant surface rubber layer 16 serving as a printing surface is applied and laminated on the intermediate laminated body 15 by the application device 7. For the supports 12 and 14, besides cotton cloth, known woven cloth such as rayon cloth and polyester cloth can be used.
For example, one or more of a vulcanizing agent such as sulfur, a vulcanization accelerator, an antioxidant and the like are added to oil-resistant rubber such as chloroprene rubber, nitrile rubber and acrylic rubber. A spreader, a knife coater, a roll coater, or the like can be used as the coating device 7, and the coating device 7 is coated and laminated to a thickness of 0.2 to 0.8 mm.

Next, a vulcanized paper 17 is brought into close contact with the surface rubber layer 16 and wound on a roll 18. Said
The vulcanized paper 17 includes the vulcanized paper described above, that is,
The surface pH of the paper is at least 6.0 and at least one of the base paper
On one side, 0.2 g / m ² or more of a fluororesin or
A vulcanized paper 17 provided with a layer of a silicone compound is used. Then, the roll 18 is put into the dry heat vulcanizing pot 11 and
Vulcanization is performed at 35 ° C. to 150 ° C. for about 10 hours. Immediately after vulcanization is completed, the process proceeds to a balancing step for removing the vulcanized paper 17 from the surface rubber layer 16. In the balancing process, the vulcanized paper 17
In the removal, only the vulcanized paper is peeled off while being wound up on a roll. Next, in the polishing step, the upper surface of the surface rubber layer 16 is polished to form a fine uneven surface having a predetermined surface roughness. This surface roughness is usually measured with a stylus type roughness meter.
The point average roughness is formed to 2 to 5 μm.

[0017]

Embodiments 1 to 4 The present invention will be described below based on embodiments.

[Manufacture of vulcanized paper] Manufacture of vulcanized paper was performed as follows. First, a pulp raw material composed of 70% by weight of LBKP and 30% by weight of NBKP was beaten to a freeness of 380 ml CSF, and the following additives were added to the pulp slurry in the pulp slurry. That is, 2.0% by weight of heavy calcium carbonate (NS-600 manufactured by Nitto Powder Chemical Co.), 0.15% by weight of alkyl ketene dimer (AS-263 manufactured by Nippon PMC), and paper strength agent (High Holder 301 manufactured by Oji National) 1 0.0% by weight, yield improver (Kurita Kogyo High Holder 301)
A chemical-added pulp slurry obtained by adding 0.02% by weight to the pulp slurry was paper-made with a fourdrinier paper machine to obtain a base paper having a basis weight of 95.0 g / m ² . The surface p of the obtained base paper
H was 6.0.

[0018]

[Adjustment of Surface pH] Based on the base paper having the surface pH of 6.0, caustic soda or a sulfate band was added to adjust the surface pH. First, the case where the surface pH of the base paper was changed and the amount of the release agent applied was fixed was examined. That is,
In Example 1, a fluororesin (Asahigard AG-manufactured by Meisei Chemical Co., Ltd.) was applied with a size press such that the coating amount (basis weight) on one surface of the base paper having a surface pH of 6.0 was 0.3 g / m ^2.
530) to obtain a vulcanized paper. In Example 2, a silicone compound (X52-151 manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to one surface of the base paper at a coating amount (basis weight) of 0.3 g / m 2.
^The mixture was applied by a size press to obtain a vulcanized paper.
In Example 3, caustic soda was added to the pulp slurry of Example 1, and the surface pH of the vulcanized paper was adjusted to 7.2. 3g / m
^The vulcanized paper was obtained by applying the above-mentioned fluororesin by a size press so as to obtain No. 2. Further, in Example 4, similarly to Example 3, caustic soda was added to the pulp slurry of Example 1, the surface pH of the vulcanized paper was adjusted to 7.2, and the surface of the obtained base paper was 0.3 g / m ^{2 of} silicone compound
By a size press to obtain a vulcanized paper.

[0019]

Comparative Examples 1 and 2 A base paper was obtained in the same manner as in Example 1 except that a sulfuric acid band was added to the pulp slurry of Example 1 and the surface pH of the vulcanized paper was adjusted to 5.1. Vulcanized paper obtained by applying the fluororesin to the surface of the base paper by a size press so as to be 0.3 g / m ² was used as Comparative Example 1. A cured paper obtained by applying the silicone-based compound to the surface of the base paper having a surface pH of 5.1 by a size press so as to be 0.3 g / m ² was used as Comparative Example 2.

[0020]

[Manufacture of blanket] As shown in FIG. 1, a rubber substrate is glued on a cotton cloth to form a support 12 which is laminated in two layers, and a compressive layer 13 is formed thereon.
An oil-resistant surface rubber layer 16 serving as a printing surface was applied and laminated on the support 3 through a support 14 made of cotton cloth. Next, the vulcanized papers of Examples 1 to 4 and Comparative Examples 1 and 2 were brought into direct contact with each other on the surface rubber 16 and wound around a vulcanizing drum.
This vulcanizing drum is placed in a dry heat vulcanizing kettle at 145 ° C. for 1 hour.
Vulcanized for 0 hours. Immediately after the vulcanization, the vulcanized paper alone was peeled off while the surface rubber layer 16 was immediately rewound on a roll. In the polishing step, the upper surface of the surface rubber layer 16 was polished to form fine irregularities. Then, the exfoliation suitability when removing each vulcanized paper from the surface rubber layer 16 was evaluated. The evaluation results are as shown in Table 1.
As is clear from Table 1, when the surface pH of the vulcanized paper was 6.0 or more, peeling from the surface rubber layer was possible, and all Examples were better than Comparative Examples. Accordingly, it has become possible to produce a printing blanket without using talc for preventing adhesion between the surface rubber layer and the vulcanized paper.

[0021]

[Table 1]

[0022]

Examples 5 to 8 In Examples 5 to 8, the case where the surface pH of the base paper was kept constant at 6.0 and the amount of the release agent applied was changed was examined. That is, in Example 5, the surface pH 6.
Example 6 was a case where a fluororesin (Asahigard AG-530 manufactured by Meisei Chemical Co., Ltd.) was applied to one surface of a base paper of No. 0 so as to have an application amount (basis weight) of 0.2 g / m ^2. Is a case in which the coating amount (weight per unit area) is 0.5 g / m ² . Further, in Example 7, a silicone compound (X52-151 manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to one surface of the base paper having a surface pH of 6.0 with a size press so that the application amount (basis weight) was 0.2 g / m ^2. Example 8 is a case in which application was performed so that the application amount (weight per unit area) was 0.5 g / m ² .

[0023]

Comparative Examples 3 and 4 The amount of the fluororesin (Asahigard AG-530 manufactured by Meisei Chemical Co., Ltd.) applied to the base paper of Example 1 was 0.1.
g / m ² was set as Comparative Example 3, and Comparative Example 4 was set with a silicone compound (X52-151 manufactured by Shin-Etsu Chemical Co., Ltd.) applied amount (weight per unit area) of 0.1 g / m ² .

[0024]

[Manufacture of blanket] A blanket was manufactured in the same manner as in Examples 1 to 4 and Comparative Examples 1 and 2, and the peeling aptitude at the time of removing the vulcanized paper from the surface rubber layer was evaluated. Table 2 shows the evaluation results. As is clear from Table 2, when the coating amount was 0.2 g / m ² or more, the vulcanized paper could be separated from the surface rubber layer, and all were better than the comparative examples. Accordingly, it has become possible to produce a printing blanket without using talc for preventing adhesion between the surface rubber layer and the vulcanized paper.

[0025]

[Table 2]

[0026]

According to the present invention, the following effects can be obtained. That is, according to the manufacturing method of the present invention,
Because talc is not used, environmental hygiene is deteriorated due to dust generated when talc is dusted or peeled from the surface rubber of vulcanized paper, and dirt on manufacturing equipment is eliminated, maintaining a good work environment and improving work efficiency. I do. In addition, in order to remove the amount of talc buried in the surface rubber layer in the polishing step, it is not necessary to secure a large polishing allowance by increasing the coating thickness of the surface rubber before polishing, and the polishing time can be shortened. The cost of the product can be reduced. Further, since the vulcanized paper of the present invention does not adhere to the applied surface rubber, the use of talc can be omitted.

[Brief description of the drawings]

FIG. 1 is a process diagram of a blanket manufacturing according to the present invention.

FIG. 2 is a process diagram of a conventional blanket manufacturing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Support 13 Compressible layer 14 Support 16 Surface rubber layer 17 Vulcanized paper

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshio Iwasaki 1 Nobesawa, Kaisei-cho, Ashigara-gun, Kanagawa Pref. Hei 5-588 (JP, A) JP-A Hei 3-290291 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41N 10/00

Claims (3)

(57) [Claims] 1. A comprising the steps of providing at least one layer surface rubber layer as a printing surface to a support, directly to the surface rubber layer, the table
Do not release the surface of the base paper having a surface pH of 6.0 or more.
A blanket for printing, comprising: a step of bringing a vulcanized paper into close contact and winding it up; a step of vulcanizing by a heating means; and a polishing step of removing the vulcanized paper and finishing the surface of a surface rubber layer. Manufacturing method. 2. The method according to claim 1, wherein the release processing of the base paper is performed on a surface of the base paper.
0.2 g / m ² or more of fluororesin or silicone
A process characterized by providing a layer of a compound.
The method for producing a printing blanket according to claim 1 . 3. The paper base paper having a surface pH of 6.0 or more.
There, on at least one surface of the base paper, 0.2 g / m ² or more
Provide a layer of fluorine resin or silicone compound on top
A vulcanized paper used in the method for producing a printing blanket according to claim 1.