JP2536763B2 - Printing blanket and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a printing blanket and a method for manufacturing the same, and more particularly, to a printing blanket having a good paper discharge property and a method for manufacturing the same.

(Technical background of the invention) As for a printing machine, for example, when an offset printing machine is taken as an example, a plate cylinder 1 around which a plate serving as a document is wound, and a blanket 5 that rotates in conjunction with the plate cylinder 1 are wound. Blanket torso 2
Also, the blanket cylinder 2 and the impression cylinder 4 for sandwiching the printing paper 3 under pressure are basically constructed. Then, ink is adhered to the plate wound around the plate cylinder 1, the image formed by the ink is once transferred to the blanket 5 of the blanket cylinder 2, and the transferred image is printed on the contacting printing paper 3. It is a thing.

In the blanket 5 used in such a printing machine, as shown in FIG. 2, a compression layer 52 of an elastic body is generally formed on a base fabric 51 as needed, and a surface layer 53 is further formed on the compression layer 52. The printing paper 3 comes into contact with the surface layer 53.

One problem in using such a printing blanket 5 is that the printing blanket 5 is attached to the printing paper 3.
It can be mentioned that the printing blanket 5 and the printing paper 3 are less likely to be peeled off after being printed by. It is considered that this is mainly caused by a vacuum state occurring between the surface layer 53 of the printing blanket 5 and the printing paper 3, and the printing paper 3 being adsorbed on the surface of the blanket 5. Therefore, as shown in FIG. 2, the surface of the surface layer 53 of the printing blanket 5 is polished to form a rough surface 54, and the rough surface 54 allows air to easily enter between the blanket 5 and the printing paper 3. And has a structure that allows good peeling.

However, in the printing blanket having the structure in which the rough surface 54 is provided by the above-described polishing, it has not been possible to maintain a good paper discharge property. That is, in order to secure a good paper discharge property, it is necessary to perform polishing for a long time and increase the number of the rough surfaces 54. However, if the number of the rough surfaces is increased in this way, the halftone dot reproducibility is deteriorated and the printing is good. This will result in being unable to do so. For this reason,
The current situation is to ensure good halftone dot reproducibility at the expense of the paper discharge property.

(Summary of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to provide a printing blanket having a better paper discharge property and halftone dot reproducibility than a conventional one, and a manufacturing method thereof. To do.

Therefore, the printing blanket according to the present invention is a printing blanket having a surface layer that comes into contact with an object to be printed on a base fabric, with an adhesive layer on the surface of the surface layer,
Cylindrical protrusions are provided at a density of 20 to 70%, the top surface dimension of the protrusions is 5 to 50 μm, and the height is 2.5 to 25 μm.

Further, according to the method for producing a printed blanket according to the present invention, an oil-resistant or solvent-resistant polymer is laminated on a base fabric, vulcanized to form a surface layer, and then an adhesive is applied to the surface layer. Then, a photosensitive resin is laminated at a rate of 2.5 to 35 g / m ² , exposed to a dot shape of 5 to 50 μm at a rate of 20 to 70%, and the non-exposed portion is removed by etching. To do.

According to the printing blanket of the present invention, cylindrical protrusions are provided on the surface of the surface layer through the adhesive layer at a density of 20 to 70%, and the size of the protrusions is 5 to 50 μm.
It has been found that a printing blanket having a good paper discharge property can be obtained by setting the height m to 2.5 m and the height to 2.5 to 25 μm. That is, as a result of diligent research on the printing blanket surface layer in which a rough surface is formed by the conventional polishing, the present inventor has found that the roughness of the rough surface of the surface layer by the conventional polishing has a height of 1 to 10 μm and a peak-peak ( (Valley-valley)
It was found that the pitch between them was in the range of 50 to 100 μm, and based on this result, the authors found a surface layer structure with good paper discharge properties and good dot reproducibility. Then, as described above, by providing a cylindrical projection through the adhesive and controlling the density and size of the projection, while maintaining good halftone dot reproducibility, it is possible to print with excellent paper discharge properties. The present invention has been completed by finding out that it becomes a blanket.

Further, according to the method for producing a printing blanket according to the present invention, an oil-resistant or solvent-resistant polymer is laminated on a base fabric and vulcanized to form a surface layer, and then an adhesive is applied to the surface layer. Along with the application, the photosensitive resin is applied at a rate of 2.5 to 35 g / m ² , and the density is 20 to 70% in a dot shape of 5 to 50 μm.
By exposing the non-exposed area at the same time and removing the unexposed area by etching, it is possible to form protrusions with good dimensional controllability, uniformity, and uniform density on the surface layer, which results in good paper ejection and halftone dots. There is an advantage that a printing blanket having reproducibility can be manufactured.

(Detailed Description of the Invention) In the printing blanket according to the present invention, as shown in FIG. 3, a compression layer 52 made of an elastic material is laminated on a base fabric 51, and a surface layer 53 is further formed on the compression layer 52. It has a formed structure. An adhesive 55 is applied on the surface of the surface layer 53, and a plurality of protrusions 56 are further formed on the adhesive layer 55, so that good paper discharge performance can be secured.

The adhesive 55 is provided to secure the adhesive strength of the protrusion 56. For this reason, the adhesive 55 is attached to the above-mentioned protrusion 56.
Basically, any material can be used as long as it can be bonded well. For example, one or more kinds of two-component urethane resin, isocyanate-containing synthetic rubber paste and the like can be used. The thickness of the adhesive layer 55 is preferably 2 to 20 μm.
It is good. If it is less than 2 μm, good adhesive strength may not be ensured, while if it exceeds 20 μm, the adhesive strength is reduced and the thickness accuracy is reduced.

The shape of the protrusion 56 formed on the adhesive layer 55 is not basically limited, and for example, as shown in the front view of FIG. 4, the top surface shape may be circular, Further, it can have various shapes such as an ellipse and a square. Also,
The arrangement of the protrusions 56 is not basically limited in the present invention, and for example, the protrusions 56 may be arranged alternately as shown in FIG.

Such a protrusion 56 is a part of the surface 53 of the present invention.
It is provided with a density of ~ 70%. If this density is less than 20%, the projections 56 may be too small to ensure good paper discharge performance, while if it exceeds 70%, the halftone dot reproducibility may be impaired.

The size of such a protrusion 56 is 5 to 50 μm. If the protrusions 56 are too small, it may be difficult for air to enter between the printing paper 3 and the printing blanket 5 and the paper ejection performance may not be good. On the other hand, if the projections 56 are more than 50 μm, halftone dot reproducibility is similarly obtained. This is because it may cause damage. here,
The dimension of the protrusion 56 is indicated by the length of the longest portion of the top surface of the protrusion 56. That is, when the shape of the top surface is circular, it is the diameter of the circle, when it is square, the diagonal line,
If the shape is elliptical, it means the length of the major axis.

The height of the protrusion 56 is 2.5 to 25 μm. If the height of the protrusions 56 is less than 2.5 μm, the paper ejection property may be deteriorated, while if it exceeds 25 μm, the halftone dot reproducibility may be impaired.

Next, a method for manufacturing the printing blanket of the present invention will be described.

According to the method for producing a printing blanket of the present invention, first, the surface layer is formed after forming the compression layer on the base fabric or without forming the layer.

When manufacturing this surface layer, first, an oil-resistant or solvent-resistant polymer, which is a base material for forming the surface layer, is provided by coating or the like on the base cloth without the compression layer.

In the present invention, the base cloth or the compression layer is not particularly limited, and the base cloth or compression layer conventionally used in this type of printing blanket can be effectively used. For example, the base fabric can be a base fabric made of cotton, strong human silk, or a reinforced fiber (Kevlar fiber or the like) having little stretchability.

The compression layer has a compressive stress of 2.0 to 8.0 kg / c.
Elastic bodies in the m ^{2 range} (stress at 1 mm / min compression rate, 0.15 mm compression) can be used. Various types of such elastic bodies are known.

According to the present invention, a surface layer is formed on such a base fabric or a compressed layer, and the body oily polymer or body solvent polymer which is the base material of the surface layer is basically used in the present invention. It is not limited. The polymers conventionally used for forming this type of surface layer can be effectively used. For example, one or more of acrylonitrile-butadiene rubber (NBR), polyvinyl chloride, chloroprene rubber, fluorine rubber, acrylic rubber, polysulfide rubber, polyurethane, hydrin rubber and the like can be used. One or more of vulcanizing agents such as sulfur, vulcanization accelerators, antioxidants, processing aids such as stearic acid, etc., added to such polymers conventionally in oil-resistant or solvent-resistant polymers. Ingredients can be added.

Such oil-resistant polymers or solvent-resistant polymers are usually used in a semi-fluid state, and examples of the solvent include at least one kind of ethane dichloride and toluene.

After the unvulcanized surface layer is formed from such an oil-resistant polymer or solvent-resistant polymer, it is vulcanized to form the surface layer 53.

After forming the surface layer 53 in this manner, the adhesive 55 is applied (FIG. 5A).

Such an adhesive 55 is as described above,
This coating amount is preferably ² to 25 g / m ² . If it is less than 2 g / m ² , the adhesive strength may not be sufficiently secured, while if it exceeds 25 g / m ² , both the adhesive strength and the thickness accuracy may be reduced.

After applying such an adhesive 55, a photosensitive resin 57 is laminated (FIG. 5c).

The photosensitive resin is not basically limited in the present invention, but may be one formed on the adhesive 55 and contacting with a printing ink, contacting with a printing object, etc. Considering this, it is preferable that it has elasticity, good compression set, oil resistance, and good adhesive strength with the adhesive 55.
As such a photosensitive resin, urethane type or polyester type can be used. Specific examples of such a photosensitive resin include, for example, APR (Asahi Kasei Co., Ltd.), Devista (Tokyo Ohka Kogyo Co., Ltd.), UD-022M (Yokohama Rubber Co., Ltd.), APL (Toray Co., Ltd.), NAPP (Japan). Paint Co., Ltd.), etc.

This photosensitive resin is applied to the surface layer at a rate of 2.5 to 35 g / m ² . If the coating amount is less than 2.5 g / m ^2, it is difficult for the height of the protrusions formed to be 2.5 μm or more, while 35 g
If it exceeds / m ² , it is also difficult to form protrusions of 25 μm or less.

After laminating such a photosensitive resin 57 on the surface layer 53, a predetermined pattern is irradiated with energy rays to form a dot-shaped exposed portion (FIG. 5C).

The exposure method of the predetermined pattern shape is not limited in the present invention. For example, a halftone dot-shaped exposed portion is formed by irradiating an energy ray (indicated by an arrow) through a mask 7 having a window 6 in a predetermined pattern shape. Can be formed. In this case, the size of the exposed portion 58 is 5 to 50 μm.
And the exposure is performed such that 20 to 70% of the area of the front surface layer is occupied by the protrusions 56 (FIG. 5d).

Ultraviolet rays are usually used as the energy rays.
This is because, for example, in the case of a resin that is exposed to visible light, the storage and exposure steps become complicated and it is not practical.

The exposed portion 58 thus exposed becomes insoluble in the etching liquid (Fig. 5d), and the projection 56 can be formed by removing the non-exposed portion 59 by etching or the like (Fig. 5f).

This etching is performed, for example, on the part not exposed to the etching solution.
This is done by dissolving 59. Such an etching solution varies depending on the type of the photosensitive resin, but examples thereof include weak alkaline water such as sodium carbonate water and sodium hydroxide water.

 Examples of the present invention will be described below.

Example After providing a compression layer on a base fabric, a surface rubber layer of unvulcanized NBR was formed and then vulcanized to form a surface layer.

A two-component urethane adhesive is applied to this surface layer at a rate of 10 g / m ² , and after drying, APR resin (photosensitive resin)
(Asahi Kasei Co., Ltd.) was laminated, and the photosensitive resin was exposed using a mask having a halftone dot pattern. The top surface dimension of the exposed portion was 25 μm and the density was 50%. What was exposed in this way was diluted with sodium carbonate solution (etching solution)
By immersing in, the non-exposed portion was removed, and a surface layer having protrusions 56 having a height of 15 μm and a top surface dimension of 25 μm at a density of 50% was formed.

After using the same base cloth and compression layer as this printing blanket and forming the surface layer using the same NBR,
A printing blanket, which was simply polished and provided with a rough surface, was manufactured for comparison, and the paper discharge property and halftone dot reproducibility were measured.

 The results are shown in Table 1.

Table 1 Paper discharge property (diagonal gap of 5 cm square after printing transfer) Example 54 mm Comparative example 1 28 mm Comparative example 2 25 mm Halftone dot reproducibility (50% halftone dot density) Example 0.63 Comparative example 1 0.67 Comparative example 2 0.78 ( EFFECTS OF THE INVENTION As is apparent from the above description, in the printing blanket according to the present invention, the projections are provided with a predetermined size, density and height through the adhesive layer, so that the paper discharge property can be remarkably improved. There is an advantage. In this case, the halftone dot reproducibility is equivalent to or slightly improved compared to the conventional one.
It has the advantage of being a printing blanket with very good performance. Further, since the adhesive layer is provided, the adhesion strength of the protrusions is good, and a printing blanket having excellent durability can be obtained.

Further, according to the method for producing a printing blanket according to the present invention, a printing blanket having the above-mentioned good halftone dot reproducibility and excellent paper discharge property has a large degree of freedom in design, good controllability, and easy It has the advantage of being manufacturable.

[Brief description of drawings]

1 is a schematic view of a printing machine, FIG. 2 is a sectional view showing the structure of a conventional printing blanket, FIG. 3 is a sectional view of an example of the printing blanket of the present invention, and FIG. 4 is a front view of the blanket. 5 and 5 are diagrams schematically showing an example of the method of the present invention. 5 ... printing blanket, 53 ... surface layer, 55 ... adhesive, 56 ... protrusion, 57 ... photosensitive resin, 58 ... exposed portion,
59 …… Non-exposed area, 6 …… Window, 7 …… Mask.

Claims (2)

(57) [Claims] 1. A printing blanket having a surface layer contacting a material to be printed on a base cloth, wherein cylindrical protrusions are provided on the surface of the surface layer via an adhesive layer at a density of 20 to 70%. , The top dimension of the protrusion is 5 to 50 μm, and the height is 2.5 to 25
A printing blanket characterized by having a thickness of μm. 2. An oil-resistant or solvent-resistant polymer is laminated on a base fabric, vulcanized to form a surface layer, an adhesive is applied to the surface layer, and then 2.5 to 35 g / m ² is applied. A method for producing a printing blanket, which comprises laminating photosensitive resins in a proportion, exposing them in a dot pattern of 5 to 50 μm at a density of 20 to 70%, and removing the non-exposed portions by etching.