Composite hydrophillic printing substrate and manufacturing and regenerating methods thereof

Abstract

The invention discloses a composite hydrophillic printing substrate and manufacturing and regenerating methods thereof. The composite hydrophilic printing substrate comprises an aluminium foil, a substrate layer arranged on a side surface of the aluminium foil, a hydrophillic layer arranged on the side of the substrate layer far from the aluminium foil and an organic plate connected to the side ofthe aluminium foil which is not provided with the hydrophillic layer. The manufacturing method comprises the following steps: coating the substrate layer on at least one side surface of the selectedaluminium foil; coating the hydrophillic layer on the side surface of the substrate layer far from the aluminium foil; coating photosensitive emulsion on a side surface of the hydrophillic layer far from the aluminium foil, and coating adhesive glue on a side surface of the aluminium foil far from the substrate layer; and adhering the organic plate to the surface of the aluminium foil coated withthe adhesive glue and pressing through lamination. The regenerating method comprises the following steps: cleaning to remove ink on the printing substrate; soaking the printing substrate with solutionof a treating agent to remove a picture and text part; and coating hydrophillic dispersion on the prior hydrophillic layer to form a new hydrophillic layer. The composite hydrophillic printing substrate has simple process and low cost.

Description

technical field [0001] The invention relates to a composite hydrophilic printing plate base and a method for manufacturing and regenerating the same. More specifically, the invention relates to a composite hydrophilic printing plate base which does not require oxidation in the manufacturing process and a method for manufacturing and regenerating the same. Background technique [0002] Lithographic printing technology is the main printing technology commonly used in the printing industry at present, and the most commonly used ones are PS technology and CTP technology. [0003] Both PS technology and CTP technology use the principle of oil-water separation for printing. That is, during the printing process, all the non-graphic parts of the surface of the printing plate base are evenly covered with water. When the printing ink is supplied to the surface of the printing plate base, the non-graphic parts covered by water cannot be stained with printing ink, so the printing ink I...

AI Technical Summary

Problems solved by technology

[0005] At present, the PS plate on the market cannot be reused after being used once, and can only be recycled as scrap aluminum, and only a very small part of it is recycled to the PS plate recycling plant for regeneration

In the regeneration process, it is generally necessary to use strong alkali to remove the aluminum oxide grains to expose the light foil, and then go through the same process as the new PS plate manufacturing process, that is, form a new sand grain layer on the light foil through anodic oxidation. Regeneration of PS plate, the thickness of the raw material is lost during the regeneration process

Generally, after 1-2 times of regeneration process, due to the limitation of plate thickness, the regeneration cannot continue

[0006] Therefore, the existing PS printing technology has many disadvantages as follows: 1. It needs to undergo electrochemical corrosion to form an aluminum oxide hydrophilic layer on the surface of the anodized aluminum plate. There are relatively large losses, and the price of aluminum and other metal materials is relatively expensive, and the price is rising day by day. Affected by the price pressure of aluminum ingots, the cost of PS plates not only increases, but also the price rises accordingly; 2. At the same time, the existing PS plates The value of the aluminum substrate accounts for about 70% of the total cost. Because the traditional PS plate has high requirements on the corrosion resistance of the substrate, and the hydrophilic layer must be formed through the anodic oxidation process, the anodic oxidation process has different types and thicknesses of the aluminum material. There are strict requirements, and it must be aluminum with high purity, which further increases the production cost of PS plates; 3. The regeneration of PS plates is to save aluminum plates, but in the process of regeneration, it will cause a lot of loss of aluminum materials At the same time, it also causes waste of electric energy and water; 4. It is necessary to carry out acid treatment and electrolytic anodizing treatment on the substrate. Cause serious pollution; 5. After many times of printing, the traditional PS printing plate base often appears dirty on the non-graphic part, so the current general PS printing plate base has a short service life. This is because the traditional PS printing plate In the production process of the substrate, it is generally made hydrophilic by corroding and anodizing the substrate. The main component of the hydrophilic layer formed by this corrosion is Al, which itself is not excellent in hydrophilicity. 2 o 3 , Wear and tear will occur after repeated use, which will reduce the hydrophilicity, and the hydrophilic surface of the printing plate base will easily lose its hydrophilicity during use. In addition, the photosensitive layer will be developed after exposure to remove the unexposed photosensitive layer. When it is used, it will also cause damage to the hydrophilic surface, and even have a certain impact on the graphic part

However, this No. 200510113287.X patent application has the following disadvantages: First, due to the performance of the hydrophilic plate coating it uses, it must make the substrate in the temperature range of 140 ° C to 180 ° C before coating Heat for 8 to 12 minutes to shrink the substrate so that it has a shrinkage rate of 0.2% to 2.0%, which increases its process complexity; secondly, the performance of the hydrophilic lithographic coating it uses depends largely on the two The amount of silica used and even the particle size, so it limits the ratio between catalyst to accelerator to crosslinker to binder to pigment to anionic surfactant to silica particles to 1:2 to 1:2 to 2 :1 to 20:25 to 60:80, which basically excludes the possibility of using other oxides, but in fact other oxides can also be used to prepare hydrophilic plate coatings; in addition, it will make the base material of the printing plate Restricted to polymeric sheets, which basically excludes the possibility of using other materials, but in fact other materials can also be used as the substrate of the printing plate; finally, the means of modifying the substrate include etching, acid treatment, etc., which will Contaminate the environment and cause damage to the substrate

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