A processing-free CTP plate that can quickly form graphic areas

Abstract

The present invention relates to a processing-free CTP plate capable of rapidly forming an image and text area, belonging to the field of printing technology. The plate comprises an aluminum substrate and an imaging coating coated on the surface of the aluminum substrate. The imaging coating comprises the following raw materials in parts by weight: 10-20 parts of a linear polyvinyl alcohol resin, 8-17 parts of a modifier, 2-4.5 parts of an infrared absorbing cyanine dye, 1-3 parts of a surfactant, and 65-115 parts of water. The modifier is a double-bond terminated hyperbranched polymer having excellent water solubility and containing a fluorine-containing chain in its molecular structure, thereby shortening the crosslinking time of the imaging coating, enabling rapid formation of images and text during development, improving the affinity of the imaging coating with the plate substrate, and improving the bonding strength between the imaging coating and the plate substrate. The fluorine-containing chain contained in the modifier has a low surface energy characteristic and is easily attracted to the surface of the imaging layer. The high bond energy characteristic of the carbon-fluorine bond in the fluorine-containing chain improves the wear resistance and printability of the imaging coating.

Description

Technical Field

[0001] The invention belongs to the field of printing technology, and in particular relates to a processing-free CTP plate capable of quickly forming a graphic area. Background Art

[0002] Process-free CTP plates are a printing technology that has rapidly developed to adapt to the upgrading of the printing industry. They are low-cost and environmentally friendly. They refer to printing technologies that do not require a development step or use a weaker alkaline developer (or water) during development. This avoids environmental pollution caused by alkaline chemical reagents during development and reduces the impact of the development step on image quality. With its low cost and environmentally friendly characteristics, it has become one of the printing technologies that has gained widespread popularity in recent years. Process-free CTP plates generally include an aluminum base layer and an imaging coating, which is divided into two types: photosensitive and thermal. The development mechanism of process-free CTP plates in a developing environment is as follows: the resin in the imaging coating undergoes a thermally induced phase change during exposure, thereby changing the coating's hydrophilicity to achieve the purpose of imaging. During exposure, the phase change resin changes from hydrophilic to oleophilic. The portion exposed to light forms the printed image area, and the unexposed portion is developed with neutral water to remove the coating, thus forming the plate image.

[0003] However, during the application process: the energy required for imaging of this type of plate during exposure is high, making it difficult to form a clear image; secondly, although the thermo-induced phase change during imaging changes the affinity of the coating, the bonding strength with the plate base is poor, resulting in poor wear resistance and low printability during printing.

[0004] Therefore, it is a technical problem that needs to be solved at present to propose a processing-free CTP plate that can quickly form graphic areas and has excellent press life. Summary of the Invention

[0005] The object of the present invention is to provide a processing-free CTP plate that can quickly form an image and text area, so as to solve the problems mentioned in the background technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A processing-free CTP plate capable of rapidly forming an image area comprises an aluminum substrate and an imaging coating coated on the surface of the aluminum substrate.

[0008] Furthermore, according to the technology known to those skilled in the art, the process-free CTP plate may further include a protective layer coated on the surface of the imaging coating layer to prevent oxidation of the imaging coating layer and prevent the imaging coating layer from undergoing phase change. The protective coating layer is composed of a process-free CTP plate protective glue.

[0009] Furthermore, the imaging coating comprises the following raw materials in parts by weight: 10-20 parts of linear polyvinyl alcohol resin, 8-17 parts of modifier, 2-4.5 parts of infrared absorbing cyanine dye, 1-3 parts of surfactant, and 65-115 parts of water.

[0010] Furthermore, the modifier is prepared by the following steps:

[0011] A1. After uniformly mixing 3-(trifluoromethoxy)benzoic acid, p-toluenesulfonic acid, a polymerization inhibitor, and toluene, the temperature of the reaction system was controlled at 75-90° C. with condensed water, and a toluene solution of citric acid was slowly added dropwise under stirring. After the addition was complete, the reaction was continued with stirring for 2-4 hours, the reaction was stopped, and the temperature was reduced to 60° C. and evaporated under reduced pressure. The resulting organic phase was washed several times with methanol and dried to obtain a tricarboxylic acid, wherein the molar ratio of 3-(trifluoromethoxy)benzoic acid to citric acid was 1:1, the mass of p-toluenesulfonic acid added was 1-3% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid added, the mass of the polymerization inhibitor added was 3-5% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid added, and the polymerization inhibitor was methylhydroquinone;

[0012] In the above reaction, the carboxyl group in 3-(trifluoromethoxy)benzoic acid reacts with the hydroxyl group in citric acid to obtain a tricarboxylic acid. It can be seen that the tricarboxylic acid contains a fluorine-containing chain.

[0013] A2. After uniformly mixing tricarboxylic acid, 1,4-butanediol, p-toluenesulfonic acid and glacial acetic acid, the temperature of the reaction system was controlled at 75-90°C with condensed water, and the reaction was stirred for 2-3 hours. Then, the mixture was kept warm and decompressed under reduced pressure ((-0.5)-(-0.1) MPa) for 1.5-2 hours. Then, a glacial acetic acid solution of a capping agent and tetrabutylammonium bromide was slowly added dropwise at normal pressure and 80-95°C. After the addition, the mixture was stirred for 4-6 hours, the reaction was stopped, and the temperature was lowered to 60°C. The mixture was rotary evaporated under reduced pressure, washed with methanol several times, and dried to obtain a modifier, wherein the mass ratio of tricarboxylic acid, 1,4-butanediol, capping agent, and tetrabutylammonium bromide was 50-75:9-10:60-62:40-50, and the mass of p-toluenesulfonic acid added was 1-3% of the total mass of the tricarboxylic acid and 1,4-butanediol.

[0014] In the above reaction, a hyperbranched polymer is obtained by the polymerization reaction between a tricarboxylic acid and 1,4-butanediol. The hyperbranched polymer is a polyester polymer with high branching characteristics. Because its structure contains a large number of carboxyl groups, it has good water solubility. The hydroxyl or carboxyl groups in the hyperbranched polymer are then reacted with the epoxy groups in the capping agent to obtain a modifier. On the one hand, the hyperbranched polymer is connected to the ether chain segment to avoid reducing the water solubility of the hyperbranched polymer. On the other hand, the hyperbranched polymer is double-bonded.

[0015] Furthermore, the capping agent is prepared by the following steps:

[0016] After 1,4-butanediol diglycidyl ether and tetrahydrofuran are uniformly mixed, the reaction temperature is controlled at 70-85°C with condensed water, and while stirring, methyl propylene glycol and tetrabutylammonium bromide tetrahydrofuran solution are slowly added dropwise. After the addition is completed, the reaction is continued with stirring for 1.5-2 hours, the reaction is stopped, the temperature is lowered to 60°C, and vacuum rotary evaporation is performed to obtain a capping agent, wherein the molar ratio of methyl propylene glycol, 1,4-butanediol diglycidyl ether, and tetrabutylammonium bromide is 1:1:1.1-1.2.

[0017] Beneficial effects of the present invention:

[0018] To solve the problems in the background technology, the present invention introduces a modifier into a linear polyvinyl alcohol resin system. The modifier is a double-bond terminated hyperbranched polymer with excellent water solubility and contains a fluorine-containing chain in its molecular structure. On the one hand, the double bonds of the modifier and the main resin (linear polyvinyl alcohol resin) are cross-linked under heat or light absorption during the development process. Because the modifier contains a large number of double bonds and a hyperbranched structure, the cross-linking time of the imaging coating is shortened, allowing the image to be formed quickly during the development process. In addition, the modifier contains ester groups, hydroxyl groups, and ether groups in its molecular structure, which improves the affinity of the imaging coating with the plate substrate and the bonding strength between the imaging coating and the plate substrate. On the other hand, the fluorine-containing chain contained in the modifier has low surface energy characteristics and is easily attracted to the surface of the imaging layer. The high bond energy characteristics of the carbon-fluorine bonds in the fluorine-containing chain improve the wear resistance and printability of the imaging coating. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1

[0021] Preparation of capping agent:

[0022] After uniformly mixing 0.1 mol of 1,4-butanediol diglycidyl ether and 60 mL of tetrahydrofuran, the reaction temperature was controlled at 70°C with condensed water. While stirring, 50 mL of a tetrahydrofuran solution containing 0.1 mol of methyl propylene alcohol and 0.11 mol of tetrabutylammonium bromide was slowly added dropwise. After the addition, the reaction was continued with stirring for 1.5 h. The reaction was stopped, the temperature was lowered to 60°C, and vacuum rotary evaporation was performed to obtain the end-capping agent.

[0023] Example 2

[0024] Preparation of capping agent:

[0025] After uniformly mixing 0.1 mol of 1,4-butanediol diglycidyl ether and 60 mL of tetrahydrofuran, the reaction temperature was controlled at 85°C with condensed water. While stirring, 50 mL of a tetrahydrofuran solution containing 0.1 mol of methyl propylene alcohol and 0.12 mol of tetrabutylammonium bromide was slowly added dropwise. After the addition, the reaction was continued with stirring for 2 h. The reaction was stopped, the temperature was lowered to 60°C, and vacuum rotary evaporation was performed to obtain the end-capping agent.

[0026] Example 3

[0027] Preparation of modifier:

[0028] A1. After uniformly mixing 0.1 mol of 3-(trifluoromethoxy)benzoic acid, p-toluenesulfonic acid, a polymerization inhibitor, and 70 mL of toluene, the temperature of the reaction system was controlled at 75° C. with condensed water, and 20 mL of a toluene solution containing 0.1 mol of citric acid was slowly added dropwise under stirring. After the addition was complete, the reaction was continued with stirring for 2 h. The reaction was stopped and the temperature was reduced to 60° C. and the organic phase was washed several times with methanol and dried to obtain a tricarboxylic acid, wherein the added mass of p-toluenesulfonic acid was 1% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, the added mass of the polymerization inhibitor was 3% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, and the polymerization inhibitor was methylhydroquinone;

[0029] A2. After uniformly mixing 50 g of tricarboxylic acid, 9 g of 1,4-butanediol, p-toluenesulfonic acid and 60 mL of glacial acetic acid, the temperature of the reaction system was controlled at 75 ° C with condensed water, and the reaction was stirred for 3 h. Then, the mixture was kept warm and reacted under reduced pressure (-0.5 MPa) for 1.5 h. Then, 100 mL of glacial acetic acid solution containing 60 g of end-capping agent and 40 g of tetrabutylammonium bromide was slowly added dropwise at normal pressure and 80 ° C. After the addition, the reaction was continued with stirring for 6 h. The reaction was stopped, and then the temperature was lowered to 60 ° C. The mixture was evaporated under reduced pressure, washed with methanol several times, and dried to obtain a modifier, wherein the added mass of p-toluenesulfonic acid was 1% of the total mass of the tricarboxylic acid and 1,4-butanediol.

[0030] Example 4

[0031] Preparation of modifier:

[0032] A1. After uniformly mixing 0.1 mol of 3-(trifluoromethoxy)benzoic acid, p-toluenesulfonic acid, a polymerization inhibitor, and 70 mL of toluene, the temperature of the reaction system was controlled at 90° C. with condensed water, and 20 mL of a toluene solution containing 0.1 mol of citric acid was slowly added dropwise under stirring. After complete addition, the reaction was continued with stirring for 2 h, the reaction was stopped, and the temperature was reduced to 60° C. and evaporated under reduced pressure. The resulting organic phase was washed several times with methanol and dried to obtain a tricarboxylic acid, wherein the added mass of p-toluenesulfonic acid was 3% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, the added mass of the polymerization inhibitor was 5% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, and the polymerization inhibitor was methylhydroquinone;

[0033] A2. After uniformly mixing 75 g of tricarboxylic acid, 10 g of 1,4-butanediol, p-toluenesulfonic acid and 60 mL of glacial acetic acid, the temperature of the reaction system was controlled at 90 ° C with condensed water, and the reaction was stirred for 2 h. Then, the mixture was kept warm and decompressed (-0.1 MPa) for 2 h. Then, 100 mL of glacial acetic acid solution containing 62 g of end-capping agent and 50 g of tetrabutylammonium bromide was slowly added dropwise at normal pressure and 95 ° C. After the addition, the reaction was continued with stirring for 4 h. The reaction was stopped, and then the temperature was lowered to 60 ° C. The mixture was evaporated under reduced pressure, washed with methanol several times, and dried to obtain a modifier, wherein the added mass of p-toluenesulfonic acid was 3% of the total mass of the tricarboxylic acid and 1,4-butanediol.

[0034] Example 5

[0035] A processing-free CTP plate capable of rapidly forming an image area comprises an aluminum substrate and an imaging coating applied on the surface thereof;

[0036] The imaging coating comprises the following raw materials in parts by weight: 10 parts of linear polyvinyl alcohol resin, 8 parts of the modifier prepared in Example 3, 2 parts of infrared absorbing cyanine dye, 1 part of surfactant (the surfactant is sodium dodecylbenzenesulfonate), and 65 parts of water.

[0037] Example 6

[0038] A processing-free CTP plate capable of rapidly forming an image area comprises an aluminum substrate and an imaging coating applied on the surface thereof;

[0039] The imaging coating comprises the following raw materials in parts by weight: 15 parts of linear polyvinyl alcohol resin, 12 parts of the modifier prepared in Example 4, 3 parts of infrared absorbing cyanine dye, 2 parts of surfactant (the surfactant is sodium dodecylbenzene sulfonate), and 100 parts of water.

[0040] Example 7

[0041] A processing-free CTP plate capable of rapidly forming an image area comprises an aluminum substrate and an imaging coating applied on the surface thereof;

[0042] The imaging coating comprises the following raw materials in parts by weight: 20 parts of linear polyvinyl alcohol resin, 17 parts of the modifier prepared in Example 3, 4.5 parts of infrared absorbing cyanine dye, 3 parts of surfactant (the surfactant is sodium dodecylbenzenesulfonate), and 115 parts of water.

[0043] Comparative Example 1

[0044] A processing-free CTP plate capable of rapidly forming an image area comprises an aluminum substrate and an imaging coating applied on the surface thereof;

[0045] Compared with Example 5, the imaging coating package is the same as Example 5 except that the modifier is replaced with a modifier prepared by the following steps:

[0046] A1. After uniformly mixing 0.1 mol of 3-(trifluoromethoxy)benzoic acid, p-toluenesulfonic acid, a polymerization inhibitor, and 70 mL of toluene, the temperature of the reaction system was controlled at 75° C. with condensed water, and 20 mL of a toluene solution containing 0.1 mol of citric acid was slowly added dropwise under stirring. After the addition was complete, the reaction was continued with stirring for 2 h. The reaction was stopped and the temperature was reduced to 60° C. and the organic phase was washed several times with methanol and dried to obtain a tricarboxylic acid, wherein the added mass of p-toluenesulfonic acid was 1% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, the added mass of the polymerization inhibitor was 3% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, and the polymerization inhibitor was methylhydroquinone;

[0047] A2. After uniformly mixing 50 g of tricarboxylic acid, 9 g of 1,4-butanediol, p-toluenesulfonic acid and 60 mL of glacial acetic acid, the temperature of the reaction system was controlled at 75 ° C with condensed water, and the reaction was stirred for 3 h. Then, the mixture was kept warm and reacted under reduced pressure (-0.5 MPa) for 1.5 h. Then, the reaction was stopped at normal pressure and 80 ° C. The temperature was then lowered to 60 ° C, and the mixture was evaporated under reduced pressure. The mixture was washed with methanol several times and dried to obtain a modifier, wherein the added mass of p-toluenesulfonic acid was 1% of the total mass of the tricarboxylic acid and 1,4-butanediol.

[0048] Comparative Example 2

[0049] A processing-free CTP plate capable of rapidly forming an image area comprises an aluminum substrate and an imaging coating applied on the surface thereof;

[0050] Compared with Example 6, the imaging coating package has the modifier deleted therein, and the rest is the same as Example 6.

[0051] Example 8

[0052] The CTP plates obtained in Examples 5-7 and Comparative Examples 1-2 were exposed and developed using an 830 nm infrared laser in a conventional manner, and then the following performance tests were performed:

[0053] Test of coating photosensitivity and solvent loss rate: The developing performance and solvent loss rate were tested according to HG / T4865 standard. The results are shown in Table 1:

[0054] Table 1

[0055]

[0056] As can be seen from the data in Table 1, the solvent resistance loss rate of the CTP plate obtained in Example 5-7 is much lower than that of the CTP plate obtained in Comparative Example 1-2, indicating that the imaging coating of the CTP plate obtained in Example 5-7 has good adhesion to the aluminum substrate. At the same time, the photosensitivity data (dot data) of the CTP plate obtained in Example 5-7 is also better than the corresponding data of the CTP plate obtained in Comparative Example 1-2, indicating that the imaging performance of the CTP plate obtained in Example 5-7 is better than that of the CTP plate obtained in Comparative Example 1-2.

[0057] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0058] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A processing-free CTP plate capable of rapidly forming graphic areas, characterized by: It includes an aluminum substrate and an imaging coating coated on the surface thereof; The imaging coating comprises the following raw materials in parts by weight: 10-20 parts of linear polyvinyl alcohol resin, 8-17 parts of modifier, 2-4.5 parts of infrared absorbing cyanine dye, 1-3 parts of surfactant, and 65-115 parts of water; The modifier comprises the following steps: After uniformly mixing tricarboxylic acid, 1,4-butanediol, p-toluenesulfonic acid and glacial acetic acid, the temperature of the reaction system is controlled at 75-90°C with condensed water, and the reaction is stirred for 2-3 hours, followed by heat preservation and reduced pressure reaction for 1.5-2 hours, and then slowly adding a blocking agent and a glacial acetic acid solution of tetrabutylammonium bromide dropwise at normal pressure and 80-95°C. After the addition is complete, the reaction is continued with stirring for 4-6 hours, the reaction is stopped, and the modifier is obtained through post-treatment; The tricarboxylic acid comprises the following steps: After 3-(trifluoromethoxy)benzoic acid, p-toluenesulfonic acid, polymerization inhibitor and toluene are evenly mixed, the temperature of the reaction system is controlled at 75-90°C with condensed water, and a toluene solution of citric acid is slowly added dropwise under stirring. After the addition is complete, the reaction is continued with stirring for 2-4 hours, and the tricarboxylic acid is obtained after post-treatment. The end-capping agent comprises the following steps: After methyl propylene glycol and tetrahydrofuran are evenly mixed, the reaction temperature is controlled at 70-85°C with condensed water. While stirring, 1,4-butanediol diglycidyl ether and tetrabutylammonium bromide tetrahydrofuran solution are slowly added dropwise. After the addition is completed, the reaction is continued with stirring for 1.5-2 hours. The reaction is stopped, the temperature is lowered to 60°C, and vacuum rotary evaporation is performed to obtain the capping agent.

2. The process-free CTP plate capable of rapidly forming graphic areas according to claim 1, characterized in that: The mass ratio of the tricarboxylic acid, 1,4-butanediol and the end-capping agent is 50-75:9-10:60-62, and the mass of the added p-toluenesulfonic acid is 1-3% of the total mass of the tricarboxylic acid and 1,4-butanediol.

3. The process-free CTP plate capable of rapidly forming graphic areas according to claim 1, characterized in that: The added mass of the p-toluenesulfonic acid is 1-3% of the total mass of the added 3-(trifluoromethoxy)benzoic acid and citric acid.

4. The process-free CTP plate capable of rapidly forming graphic areas according to claim 1, characterized in that: The added mass of the polymerization inhibitor is 3-5% of the total mass of 3-(trifluoromethoxy)benzoic acid and citric acid, and the polymerization inhibitor is methylhydroquinone.

5. The process-free CTP plate capable of rapidly forming graphic areas according to claim 1, characterized in that: The molar ratio of the 3-(trifluoromethoxy)benzoic acid to the citric acid is 1:

1.

6. The process-free CTP plate capable of rapidly forming graphic areas according to claim 1, characterized in that: The molar ratio of methyl propylene alcohol, 1,4-butanediol diglycidyl ether and tetrabutylammonium bromide is 1:1:1.1-1.2.

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