Production process of treatment-free CTP plate material

Abstract

The invention provides a treatment-free CTP plate production process, and relates to the technical field of CTP plates. The method comprises the following steps: carrying out alkali washing oil removal, electrolysis sand mesh production, anodic oxidation and hole sealing on an aluminum base plate, then coating a photosensitive resist in a layered manner, drying, feeding the plate material into a CTP plate making machine, exposing according to an image signal, immersing the exposed plate material into a weakly alkaline fountain solution, washing an unexposed part, dissolving a hydrophilic group, developing, washing with deionized water, and then drying at a low temperature; the photosensitive adhesive comprises the following components: a resin carrier, a photosensitive group, a wear-resistant reinforcing agent and a functional auxiliary agent, the drying in the step S5 is gradient drying. The scratch resistance of the photosensitive resist is optimized, and the performance of a plate material is prevented from being influenced.

Description

Technical Field

[0001] This invention relates to the field of CTP plate technology, and specifically to a process for producing CTP plates without processing. Background Technology

[0002] CTP plates without processing are printing plate-making materials that directly transfer images to the plate through laser scanning. They do not require traditional chemical developing processes and can be made simply by developing with water.

[0003] In the existing technology, untreated CTP plates inevitably develop microcracks or microdamage that are difficult to detect. These cracks or damages will gradually worsen during use, resulting in the CTP plate having no wear-resistant support, low printing durability, and affecting the performance of the plate. Summary of the Invention

[0004] The purpose of this invention is to develop a treatment-free CTP plate production process that optimizes the scratch resistance of photosensitive emulsion and avoids affecting the plate performance.

[0005] This invention is achieved through the following technical solution: A process for producing CTP plates without processing includes the following steps: S1. The aluminum plate substrate is subjected to alkaline washing to remove oil, followed by water washing; S2. After degreasing and cleaning, the aluminum plate base is placed in an electrolytic cell. The electrolyte is hydrochloric acid solution, which produces sand particles. Then it is washed with water. S3. The aluminum substrate is anodized using sulfuric acid solution to produce a dense oxide layer, followed by water washing. S4. Seal the micropores with a sealing liquid, then wash with water and dry. The sealing liquid can be hot water or sodium silicate solution. S5. Apply photosensitive emulsion in layers: first apply the base photosensitive emulsion and dry it, then apply the top photosensitive emulsion and dry it. S6. The plate is fed into the CTP plate-making machine and exposed according to the image signal. After exposure, the plate is immersed in a weak alkaline dampening solution to rinse the unexposed parts, dissolve the hydrophilic groups, develop, rinse with deionized water, and then dry at low temperature. S7. After drying, the plate is irradiated with ultraviolet light to trigger secondary cross-linking; S8. Detects image accuracy, coating defects, scratch resistance, and printing durability; S9. Obtain the finished product and cut it to the required size; The photosensitive adhesive comprises a resin carrier, photosensitive groups, abrasion-resistant enhancers, and functional additives. In step S5, the drying process is gradient drying.

[0006] Optionally, the resin carrier is an acrylic-hydroxyethyl acrylate-maleic anhydride terpolymer resin.

[0007] Optionally, the photosensitive group includes cyanin infrared absorbers, free radical initiators, and co-initiators.

[0008] Optionally, the cyanine infrared absorber is neoindocyanine green, the free radical initiator is 1173 photoinitiator, and the co-initiator is triethanolamine.

[0009] Optionally, the wear-resistant reinforcing agent includes modified nano-alumina, nano-silica, multifunctional crosslinking agent, and ultraviolet crosslinking accelerator.

[0010] Optionally, the multifunctional crosslinking agent includes 9,10-bisphenylanthracene and trimethylolpropane triacrylate, and the ultraviolet crosslinking accelerator is benzophenone.

[0011] Optionally, the functional additives include a developer enhancer, a surface lubricant, a fluorocarbon surfactant, and propylene glycol methyl ether. The developer enhancer is AEO-9, the surface lubricant is reactive PDMS, and the fluorocarbon surfactant is perfluorooctyl ethyl acrylate.

[0012] Optionally, the preparation process of the photosensitive adhesive includes: Modified nano-alumina and nano-silica, used as wear-resistant reinforcing agents, are mixed with propylene glycol methyl ether, used as functional additives, and then dispersed by high-speed shearing and stirring followed by ultrasonication. Add acrylic-hydroxyethyl acrylate-maleic anhydride terpolymer resin as resin carrier, new indocyanine green as photosensitive group, 1173 photoinitiator, triethanolamine to the reaction vessel, and then add propylene glycol methyl ether as functional additive. Stir at low speed and control the temperature at 23±2℃ to avoid thermal decomposition of the photosensitizer. AEO-9, reactive PDMS, perfluorooctyl ethyl acrylate, 9,10-diphenyl anthracene, trimethylolpropane triacrylate, and benzophenone were added sequentially to the reaction vessel as functional additives. Stirring was continued, and the entire process was carried out in the dark to prevent the photosensitizer from reacting prematurely. The coating undergoes filtration and impurity removal. It is filtered under pressure by a filter element to remove particulate impurities. After filtration, the coating is clear and transparent with no visible impurities.

[0013] Optionally, the gradient drying in step S5 includes: the first stage of heating is infrared radiation heating at a temperature of 70±2℃; the second stage of heating is hot air circulation heating at a temperature of 110±2℃; the third stage of heating is a combination of infrared radiation heating and hot air heating at a temperature of 140±2℃; and the fourth stage of heating is low-temperature hot air shaping at a temperature of 80±2℃.

[0014] Optionally, after step S7 is completed, a polyvinyl alcohol protective adhesive is applied to enhance scratch resistance and moisture resistance.

[0015] The beneficial effects of this invention are: This invention employs a layered photosensitive emulsion coating, which enhances the adhesion between the aluminum plate base and the photosensitive emulsion, preventing the entire coating from peeling off during printing. The base coating strengthens adhesion, while the top coating enhances abrasion resistance, improving the printing plate's durability. The added abrasion-resistant enhancer optimizes the photosensitive emulsion's scratch resistance and increases print yield. The photosensitive emulsion is environmentally friendly with low VOC content, meeting green production requirements. Gradient drying improves drying efficiency and shortens drying time while ensuring minimal solvent residue, preventing coating blistering and cracking. Detailed Implementation

[0016] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the following description is to be considered exemplary in nature and not restrictive.

[0017] The embodiments of the present invention will be described in detail below.

[0018] This invention discloses a process for producing CTP plates without processing, comprising the following steps: S1. The aluminum plate substrate is subjected to alkaline washing to remove oil, followed by water washing; S2. After degreasing and cleaning, the aluminum plate base is placed in an electrolytic cell. The electrolyte is hydrochloric acid solution, which produces sand particles. Then it is washed with water. S3. The aluminum substrate is anodized using sulfuric acid solution to produce a dense oxide layer, followed by water washing. S4. Seal the micropores with a sealing liquid, then wash with water and dry. The sealing liquid can be hot water or sodium silicate solution. S5. Apply photosensitive emulsion in layers: first apply the base photosensitive emulsion and dry it, then apply the top photosensitive emulsion and dry it. S6. The plate is fed into the CTP plate-making machine (830nm infrared laser), exposed according to the image signal, and after exposure, the plate is immersed in a weak alkaline dampening solution to rinse the unexposed parts, dissolve the hydrophilic groups, develop, rinse with deionized water, and then dry at low temperature. S7. After drying, the plate is irradiated with ultraviolet light to trigger secondary cross-linking, which enhances the hardness and wear-resistant adhesion of the coating. S8. Detects image accuracy, coating defects, scratch resistance, and printing durability; S9. Obtain the finished product and cut it to the required size; The components of photosensitive emulsion include resin carrier, photosensitive groups, abrasion-resistant enhancers, and functional additives. The resin carrier is a terpolymer resin of acrylic acid-hydroxyethyl acrylate-maleic anhydride and a silane coupling agent, which provides hydrophilic groups and carboxyl / anhydride groups to ensure that the unexposed part is soluble in the dampening solution. The photosensitive groups include cyanine infrared absorbers, free radical initiators, and co-initiators. The cyanine infrared absorber is neoindocyanine green (IR-820), the free radical initiator is 1173 photoinitiator (HMPP), and the co-initiator is triethanolamine. The wear-resistant reinforcing agent includes modified nano-alumina (modified with KH-570 silane coupling agent), nano-silica, multifunctional crosslinking agent, and ultraviolet crosslinking accelerator. The multifunctional crosslinking agent includes 9,10-diphenylanthracene (DPHA) and trimethylolpropane triacrylate (TMPTA), and the ultraviolet crosslinking accelerator is benzophenone. Functional additives include developer enhancers, surface lubricants, fluorocarbon surfactants, and propylene glycol methyl ether. The developer enhancer is AEO-9, the surface lubricant is reactive PDMS, and the fluorocarbon surfactant is perfluorooctyl ethyl acrylate. The preparation process of photosensitive emulsion includes: Modified nano-alumina, nano-silica, and propylene glycol methyl ether were mixed, sheared and stirred at high speed, and then ultrasonically dispersed. The shearing speed was 3000-5000 r / min for 20-30 minutes, and the ultrasonic power was 500W for 15-20 minutes. This resulted in a particle size of ≤50nm detectable by a laser particle size analyzer, with no agglomeration. Add acrylic acid-hydroxyethyl acrylate-maleic anhydride terpolymer resin, IR-820, HMPP, triethanolamine to the reaction vessel, then add propylene glycol methyl ether, stir at low speed (800-1000 r / min) for 30 minutes, and control the temperature at 23±2℃ to avoid thermal decomposition of the photosensitizer. Add AEO-9, reactive PDMS, perfluorooctyl ethyl acrylate, DPHA, TMPTA, and benzophenone to the reactor in sequence, and continue stirring at a speed of 600-800 r / min for 20 minutes. The entire process should be carried out in the dark to prevent the photosensitizer from reacting prematurely. The coating is filtered to remove impurities. It is then filtered under pressure using a 1μm filter element at a pressure of 0.2-0.3MPa to remove particulate impurities. After filtration, the coating is clear and transparent with no visible impurities, and the viscosity is controlled at 20-30cP (25℃, measured by a rotational viscometer). In step S5, the drying is a gradient drying process. The first stage of heating is infrared radiation heating at a temperature of 70±2℃. The second stage of heating is hot air circulation heating at a temperature of 110±2℃. The third stage of heating is a combination of infrared radiation heating and hot air heating at a temperature of 140±2℃. The fourth stage of heating is low-temperature hot air shaping at a temperature of 80±2℃. After step S7 is completed, a polyvinyl alcohol protective coating (concentration 3%-5%) can be applied to enhance scratch resistance and moisture resistance.

[0019] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of the patent of the present invention.

Claims

1. A process for producing CTP plates without processing, characterized in that, Includes the following steps: S1. The aluminum plate substrate is subjected to alkaline washing to remove oil, followed by water washing; S2. After degreasing and cleaning, the aluminum plate base is placed in an electrolytic cell. The electrolyte is hydrochloric acid solution, which produces sand particles. Then it is washed with water. S3. The aluminum substrate is anodized using sulfuric acid solution to produce a dense oxide layer, followed by water washing. S4. Seal the micropores with a sealing liquid, then wash with water and dry. The sealing liquid can be hot water or sodium silicate solution. S5. Apply photosensitive emulsion in layers: first apply the base photosensitive emulsion and dry it, then apply the top photosensitive emulsion and dry it. S6. The plate is fed into the CTP plate-making machine and exposed according to the image signal. After exposure, the plate is immersed in a weak alkaline dampening solution to rinse the unexposed parts, dissolve the hydrophilic groups, develop, rinse with deionized water, and then dry at low temperature. S7. After drying, the plate is irradiated with ultraviolet light to trigger secondary cross-linking; S8. Detects image accuracy, coating defects, scratch resistance, and printing durability; S9. Obtain the finished product and cut it to the required size; The photosensitive adhesive comprises a resin carrier, photosensitive groups, abrasion-resistant enhancers, and functional additives. The drying process in step S5 is gradient drying.

2. The process for producing CTP plates without processing according to claim 1, characterized in that, The resin carrier is an acrylic acid-hydroxyethyl acrylate-maleic anhydride terpolymer resin.

3. The process for producing CTP plates without processing according to claim 1, characterized in that, The photosensitive group includes cyanin infrared absorbers, free radical initiators, and co-initiators.

4. The process for producing CTP plates without processing according to claim 3, characterized in that, The cyanine infrared absorber is neoindocyanine green, the free radical initiator is 1173 photoinitiator, and the co-initiator is triethanolamine.

5. The process for producing CTP plates without processing according to claim 1, characterized in that, The wear-resistant reinforcing agent includes modified nano-alumina, nano-silica, multifunctional crosslinking agent, and ultraviolet crosslinking accelerator.

6. The process for producing CTP plates without processing according to claim 5, characterized in that, The multifunctional crosslinking agent includes 9,10-bisphenylanthracene and trimethylolpropane triacrylate, and the ultraviolet crosslinking accelerator is benzophenone.

7. The process for producing CTP plates without processing according to claim 1, characterized in that, The functional additives include a developer enhancer, a surface lubricant, a fluorocarbon surfactant, and propylene glycol methyl ether. The developer enhancer is AEO-9, the surface lubricant is reactive PDMS, and the fluorocarbon surfactant is perfluorooctyl ethyl acrylate.

8. The process for producing CTP plates without processing according to claim 1, characterized in that, The preparation process of the photosensitive adhesive includes: Modified nano-alumina and nano-silica, used as wear-resistant reinforcing agents, are mixed with propylene glycol methyl ether, used as functional additives, and then dispersed by high-speed shearing and stirring followed by ultrasonication. Add acrylic-hydroxyethyl acrylate-maleic anhydride terpolymer resin as resin carrier, new indocyanine green as photosensitive group, 1173 photoinitiator, triethanolamine to the reaction vessel, and then add propylene glycol methyl ether as functional additive. Stir at low speed and control the temperature at 23±2℃ to avoid thermal decomposition of the photosensitizer. AEO-9, reactive PDMS, perfluorooctyl ethyl acrylate, 9,10-diphenyl anthracene, trimethylolpropane triacrylate, and benzophenone were added sequentially to the reaction vessel as functional additives. Stirring was continued, and the entire process was carried out in the dark to prevent the photosensitizer from reacting prematurely. The coating undergoes filtration and impurity removal. It is filtered under pressure by a filter element to remove particulate impurities. After filtration, the coating is clear and transparent with no visible impurities.

9. The process for producing CTP plates without processing according to any one of claims 1 to 8, characterized in that, The gradient drying in step S5 includes: the first stage of heating is infrared radiation heating at a temperature of 70±2℃; the second stage of heating is hot air circulation heating at a temperature of 110±2℃; the third stage of heating is a combination of infrared radiation heating and hot air heating at a temperature of 140±2℃; and the fourth stage of heating is low-temperature hot air shaping at a temperature of 80±2℃.

10. The process for producing CTP plates without processing according to claim 1, characterized in that, After step S7 is completed, a polyvinyl alcohol protective adhesive is applied to enhance scratch resistance and moisture resistance.