A UV-resistant ink CTP plate imaging coating, a UV-resistant ink CTP plate and a preparation method thereof

Abstract

The present application relates to the technical field of printing plate coatings, and specifically discloses a UV-resistant ink CTP plate imaging coating, a UV-resistant ink CTP plate, and a preparation method thereof. The technical points are: a UV-resistant ink CTP plate imaging coating, which is made of the following components in parts by weight: 10-60 parts of acrylamide-acrylate polymer, 10-60 parts of mixed phenol resin, 2-12 parts of solubilizer, 3-25 parts of dissolution-promoting resin, 0-1 parts of retardant resin, 1-5 parts of infrared absorbing dye, and 1-2 parts of dye. The UV-resistant ink CTP plate uses the above-mentioned coating as an imaging coating and is made of an aluminum-based plate. The preparation method thereof is: S1, using phosphoric acid or acetone cleaning solution to clean the surface of the plate base and dry it; S2, applying the imaging coating. The coating prepared in the present application can be applied in a single layer, which simplifies the process, improves the yield rate, and reduces the cost.

Description

Technical Field

[0001] The present application relates to the technical field of printing plate coatings, and more specifically, to a UV-resistant ink CTP plate imaging coating, a UV-resistant ink CTP plate, and a preparation method thereof. Background Art

[0002] Thermal CTP plate is an offset printing plate that uses 830nm laser for imaging. Due to its easy production, moderate cost, brightroom operation, high imaging quality and ease of use, it has accounted for a considerable proportion of the entire offset printing plate.

[0003] Ordinary thermal CTP plates can only be used for printing with ordinary offset inks. If used for printing with UV inks, the surface coating will be quickly dissolved by the UV inks and its life will end after a few hundred prints. As UV ink printing is increasingly used in packaging printing, the demand for thermal CTP plates with UV ink resistance is becoming more and more urgent.

[0004] At present, the thermal CTP plates in the market are all coated with double layers on the surface. The surface layer plays an imaging role but is not resistant to printing, while the bottom layer has no imaging property but is relatively resistant to printing. After laser scanning, the non-graphic part of the surface layer changes and is dissolved during the development process to expose the bottom layer. The bottom layer has good solvent resistance but is easily dissolved by alkaline developer. Only the surface layer and the bottom layer of the graphic part are retained. The surface layer wears out quickly during printing, and the bottom layer plays the leading role in printing resistance. Double-layer coated UV-resistant ink thermal CTP plates have the advantage of high printing resistance.

[0005] With respect to the above-mentioned related technologies, the inventors believe that when preparing a double-layer coated CTP plate, a bottom layer is first coated on the surface of the base plate, and after the bottom layer is formed and dried, the surface layer is coated to form a double-layer coating, which has the disadvantages of complex process and high cost. Summary of the invention

[0006] In order to simplify the CTP plate coating process, reduce costs, and improve the yield rate, the present application provides a UV-resistant ink CTP plate imaging coating, a UV-resistant ink CTP plate and a preparation method thereof.

[0007] In the first aspect, the present application provides a UV-resistant ink CTP plate imaging coating, which adopts the following technical solution:

[0008] A UV-resistant ink CTP plate imaging coating is prepared from the following components in parts by weight: 10-60 parts of acrylamide-acrylate polymer, 10-60 parts of mixed phenol resin, 2-12 parts of solubilizer, 3-25 parts of dissolution-promoting resin, 0-1 part of dissolution-resistant resin, 1-5 parts of infrared absorbing dye and 1-2 parts of dye.

[0009] By adopting the above technical scheme, acrylamide-acrylate polymer can resist the dissolution of UV ink; mixed phenol resin can be used to form a film, so that a uniform film is formed during coating, and it absorbs ink and resists mechanical wear during printing, and its alkali resistance is better than that of inter-phenol resin; solubilizer and dissolution-promoting resin are used to increase the solubility of coating development; anti-dissolution resin protects the graphics during development and increases resolution; infrared absorbing dyes are used for photothermal conversion, so that the molecular structure of the area scanned by the laser changes and is easily dissolved during development; dyes make the graphics easier to observe after development. The imaging layer provided in this application only needs to be coated with a layer on the surface of the plate base after sealing, and it does not need to coat the bottom layer to obtain the same printing durability as the double-layer coated CTP plate. Since the steps of coating the bottom layer are reduced, the process is simplified, the yield rate is improved, and the cost is reduced.

[0010] More preferably, the solubilizing agent is tetrahydrophthalic anhydride or alkoxybenzoic acid.

[0011] By adopting the above technical solution, the solubilizer is used to increase the solubility of the coating development, and the solubilizer is selected from tetrahydrophthalic anhydride or alkoxybenzoic acid, wherein tetrahydrophthalic anhydride can also improve the adhesion, elasticity, gloss and solubility resistance of the coating.

[0012] More preferably, the mixed phenol resin is a mixture of a polymer condensed from m-cresol and formaldehyde and a polymer condensed from p-cresol and formaldehyde, and the number average molecular weight of the mixed phenol resin is 6,000-10,000.

[0013] By adopting the above technical solution, mixed phenol resin is used to replace meta-phenol resin, and the mixed phenol resin has better alkali resistance.

[0014] More preferably, the dissolution-promoting resin is an alkylphenol formaldehyde resin with a number average molecular weight of 3000-5500, and the dissolution-retarding resin is an alkylphenol formaldehyde resin with a number average molecular weight of 10000-12000.

[0015] By adopting the above technical solution, the dissolution-promoting resin and the dissolution-retarding resin can improve the alkali resistance of the mixed phenol resin and also increase the developability of the coating.

[0016] More preferably, the infrared absorbing dye is a 830nm thermosensitive infrared absorbing cyanine dye.

[0017] By adopting the above technical solution, infrared absorbing dyes are used for photothermal conversion, so that the molecular structure of the area scanned by the laser changes and is easily dissolved during development. The maximum absorption peak of the 830nm thermosensitive infrared absorbing cyanine dye is at 830nm. It is soluble in a variety of organic solvents with good solubility and has the appearance of reddish-brown sparkling crystals.

[0018] More preferably, the dye is ethyl violet or Victoria blue.

[0019] By adopting the above technical solution, the dye makes the pattern easier to observe after development. The present application adopts ethyl violet or Victoria blue, which has a darker color and good dyeing property.

[0020] In the second aspect, the present application provides a UV-resistant ink CTP plate, which adopts the following technical solution:

[0021] A UV-resistant ink CTP plate material consists of a plate base and the above-mentioned imaging coating.

[0022] By adopting the above technical solution and using the above imaging coating to coat the substrate, only one layer of coating is needed to achieve a good printing effect, which not only reduces the coating steps and simplifies the process, but also improves the yield and reduces the cost.

[0023] More preferably, the substrate is an aluminum substrate.

[0024] By adopting the above technical solution, an aluminum base plate is used as the plate base, the quality is easy to control, the printing performance is good, and the surface defects of the aluminum base plate are easy to control and the quality is relatively stable.

[0025] In a third aspect, the present application provides a method for preparing a UV-resistant ink CTP plate, using the following technical solution:

[0026] A method for preparing a UV-resistant ink CTP plate comprises the following steps:

[0027] S1. Clean the surface of the substrate with phosphoric acid or acetone cleaning solution and dry it;

[0028] S2. Applying an imaging coating.

[0029] By adopting the above technical solution, the imaging layer in the present application is used to replace the double-layer coating, the process is simplified, and the prepared plate can improve the yield during the printing process, thereby reducing costs.

[0030] Further preferably, the substrate is roughened before coating, and the specific steps are: coating the treatment liquid on the surface of the substrate, washing with deionized water for 1-2 minutes, and drying, wherein the treatment liquid is composed of the following components in parts by weight: 5-10 parts of a hydrochloric acid solution with a concentration volume ratio of 3%, 0.1-0.3 parts of thiourea, 0.5-1 parts of aluminum phosphate, 0.3-0.5 parts of methyl glucose polyoxyethylene ether, and 0.3-0.5 parts of polyoxyethylene fatty alcohol ether.

[0031] By adopting the above technical scheme, the surface of the aluminum substrate is pre-treated with the above treatment liquid to form a slightly uneven rough surface on its surface, thereby improving the bonding strength of the subsequent coating and ensuring the printing durability of the coating. The present application adopts the treatment liquid prepared with the above components and can ensure that the surface roughness of the aluminum substrate is uniform.

[0032] In summary, this application has the following beneficial effects:

[0033] (1) The imaging layer of the present application only needs to be coated on the surface of the 1050 aluminum substrate after the holes are sealed. Since the coating steps of the bottom layer are reduced, the process is simplified, the yield is improved, and the cost is reduced;

[0034] (2) The imaging layer prepared by the present application has strong resistance to UV ink, is not easily dissolved, and the printing life is greatly extended;

[0035] (3) When preparing the CTP plate, the surface of the aluminum substrate is first pretreated to make its surface uniformly roughened, and then the coating treatment is performed, which can greatly improve the bonding force of the imaging layer on the surface of the aluminum substrate and increase the service life of the coating. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the embodiments.

[0037] Example

[0038] Example 1

[0039] A UV-resistant ink CTP plate is prepared by the following steps:

[0040] S1. Clean the surface of the aluminum substrate with phosphoric acid cleaning solution and dry it;

[0041] S2. Apply UV-resistant ink CTP plate imaging coating to the surface of aluminum substrate. After drying, the residual solvent is controlled below 3% and the coating weight is controlled at 1.5-1.6g / m 2 , and obtain UV-resistant ink CTP plate.

[0042] The above-mentioned UV-resistant ink CTP plate imaging coating is made of the following components by weight: 1 kg acrylamide-acrylate polymer, 0.6 kg mixed phenol resin, 0.2 kg solubilizer, 0.3 kg solubility-promoting resin, 0.1 kg resistance resin, 0.1 kg infrared absorption dye, and 0.1 kg dye.

[0043] The mixed phenol resin is a mixture of a polymer condensed from m-cresol and formaldehyde and a polymer condensed from p-cresol and formaldehyde, and the number average molecular weight of the mixed phenol resin is 6000-10000; the solubilizer is tetrahydrophthalic anhydride; the solubility-promoting resin is an alkylphenol formaldehyde resin, and the number average molecular weight is 3000-5500; the anti-solvent resin is an alkylphenol formaldehyde resin, and the number average molecular weight is 10000-12000; the infrared absorbing dye is an 830nm thermosensitive infrared absorbing cyanine dye; and the dye is ethyl violet.

[0044] Example 2

[0045] A UV-resistant ink CTP plate, which is different from Example 1 in that the UV-resistant ink CTP plate imaging coating used is made of components including the following weights: 3.5 kg of acrylamide-acrylate polymer, 3.5 kg of mixed phenol resin, 0.7 kg of solubilizer, 1.4 kg of solubility-promoting resin, 0.05 kg of resistance resin, 0.3 kg of infrared absorbing dye, and 0.15 kg of dye.

[0046] Example 3

[0047] A UV-resistant ink CTP plate, which is different from Example 1 in that the UV-resistant ink CTP plate imaging coating used is made of components including the following weights: 6 kg of acrylamide-acrylate polymer, 1 kg of mixed phenol resin, 1.2 kg of solubilizer, 2.5 kg of solubilizing resin, 0.5 kg of infrared absorbing dye, and 0.2 kg of dye.

[0048] Example 4

[0049] A UV-resistant ink CTP plate, which is different from Example 1 in that the solubilizer is alkoxybenzoic acid.

[0050] Example 5

[0051] A UV-resistant ink CTP plate, which is different from Example 1 in that the dye is Victoria blue.

[0052] Example 6

[0053] A UV-resistant ink CTP plate, which is different from Example 1 in that it is prepared by the following steps:

[0054] S1, take 0.5kg of 3% volume ratio hydrochloric acid solution, 0.01kg of thiourea, 0.05kg of aluminum phosphate, 0.03 parts of methyl glucose polyoxyethylene ether, and 0.03kg of polyoxyethylene fatty alcohol ether, mix them evenly to obtain a treatment solution, apply the treatment solution to the surface of the aluminum plate, wash it with deionized water after 1 minute, and dry it;

[0055] S2, using acetone cleaning solution to clean the surface of the aluminum substrate for a second time, and then drying it;

[0056] S3, apply UV-resistant ink CTP plate imaging coating to the surface of aluminum base plate, control the residual solvent content below 3% after drying, and control the coating weight to 1.5-1.6g / m 2 , and obtain UV-resistant ink CTP plate.

[0057] Example 7

[0058] A UV-resistant ink CTP plate, which is different from Example 1 in that it is prepared by the following steps:

[0059] S1, take 0.75kg of 3% volume ratio hydrochloric acid solution, 0.02kg of thiourea, 0.075kg of aluminum phosphate, 0.04 parts of methyl glucose polyoxyethylene ether, and 0.04kg of polyoxyethylene fatty alcohol ether, mix them evenly to obtain a treatment solution, apply the treatment solution to the surface of the aluminum substrate, wash it with deionized water after 1.5 minutes, and dry it;

[0060] S2, using phosphoric acid cleaning solution to clean the surface of the aluminum substrate for a second time, and then drying it;

[0061] S3, apply UV-resistant ink CTP plate imaging coating to the surface of aluminum base plate, control the residual solvent content below 3% after drying, and control the coating weight to 1.5-1.6g / m 2 , and obtain UV-resistant ink CTP plate.

[0062] Example 8

[0063] A UV-resistant ink CTP plate, which is different from Example 1 in that it is prepared by the following steps:

[0064] S1, take 1kg of 3% volume ratio hydrochloric acid solution, 0.03kg of thiourea, 0.1kg of aluminum phosphate, 0.05 parts of methyl glucose polyoxyethylene ether, and 0.05kg of polyoxyethylene fatty alcohol ether, mix them evenly to obtain a treatment solution, apply the treatment solution to the surface of the aluminum plate, wash with deionized water after 2 minutes, and dry;

[0065] S2, using phosphoric acid cleaning solution to clean the surface of the aluminum substrate for a second time, and then drying it;

[0066] S3, apply UV-resistant ink CTP plate imaging coating to the surface of aluminum base plate, control the residual solvent content below 3% after drying, and control the coating weight to 1.5-1.6g / m 2 , and obtain UV-resistant ink CTP plate.

[0067] Comparative Example

[0068] Comparative Example

[0069] A CTP plate is prepared by the following steps:

[0070] S1. Clean the surface of the aluminum substrate with phosphoric acid cleaning solution and dry it;

[0071] S3, coating the aluminum substrate with a hydrophilic primer, wherein the hydrophilic primer is a terpolymer of vinylidene chloride / methyl acrylate / methyl succinic acid;

[0072] S2. Mechanically apply an imaging coating on the surface of the hydrophilic primer. The imaging coating components include 100 g of a 10% aqueous solution of polyester vinyl ester, 20 g of methyl orthosilicate, 300 g of a 10% aqueous solution of calcium silicate, 3 g of a 10% aqueous solution of polyquaternium 3, and 5 g of a 10% aqueous solution of Triton X-100.

[0073] Performance testing

[0074] The CTP plates prepared in Examples 1-8 and the comparative example were tested respectively. A 465mm×380mm format was taken, and imaging was performed on a COLOR TP-2624E laser platemaking machine. The plates were developed in a DV-T developer at 23°C for 25s. The dots were tested with ICPlate, and the coating residue in the full exposure area was tested with acetone to determine which level of energy laser could just clear the bottom. UV ink car wash water was dripped onto the surface of the baked plate, and dried with a paper towel after 1 minute. The optical density D1 of the part contacted with the liquid and the optical density D2 of the peripheral part not contacted with the liquid were tested with an X-Rite densitometer 504, and the value of D1 / D2 was calculated. The larger the value, the better the surface resistance to UV ink car wash water, and the higher the printing resistance when UV ink printing is performed.

[0075] It can be seen from the test data in Table 1 that, compared with the double-layer CTP plate in the comparative example, the CTP plate in Examples 1-8 only needs to coat one imaging layer on the aluminum base plate, which simplifies the process, increases the yield rate to more than 90%, greatly reduces the cost, and has good reproducibility. Compared with the comparative example, when the CTP plates in Examples 6-8 are made, the surface of the secondary aluminum base plate is treated to improve the adhesion of the coating and the coating performance, so that its D1 / D2 value is stably higher than the D1 / D2 value in the comparative example, indicating that the CTP plate molding coating prepared in Examples 6-8 has strong resistance to UV ink, is not easily dissolved, and has a long printing life.

[0076] Group Yield rate (%) 10% outlets Clearing energy (mW) UV ink resistance (D1 / D2) Example 1 90.8 9.4 160 0.56 Example 2 90.7 9.6 160 0.55 Example 3 91.2 9.5 170 0.56 Example 4 91.5 9.4 160 0.57 Example 5 90.8 9.3 170 0.52 Example 6 92.3 9.5 170 0.66 Example 7 92.6 9.5 160 0.66 Example 8 92.5 9.6 160 0.67 Comparative Example 80.2 9.2 160 0.60

[0077] The above is only the preferred implementation of the present application. The protection scope of the present application is not limited to the above embodiments. All technical solutions under the concept of the present application belong to the protection scope of the present application. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present application should also be regarded as the protection scope of the present application.

Claims

1. A method for preparing a UV-resistant ink CTP plate, characterized in that: The steps include: S1. Clean the surface of the substrate with phosphoric acid or acetone cleaning solution and dry it; S2, coating the imaging coating; The substrate is also roughened before coating, and the specific steps are: coating the surface of the substrate with a treatment liquid, washing with deionized water for 1-2 minutes, and drying, wherein the treatment liquid is composed of the following components in parts by weight: 5-10 parts of a hydrochloric acid solution with a concentration volume ratio of 3%, 0.1-0.3 parts of thiourea, 0.5-1 parts of aluminum phosphate, 0.3-0.5 parts of methyl glucose polyoxyethylene ether, and 0.3-0.5 parts of polyoxyethylene fatty alcohol ether.

2. The method for preparing a UV-resistant ink CTP plate according to claim 1, characterized in that: The UV-resistant ink CTP plate imaging coating is prepared from the following components in parts by weight: 10-60 parts of acrylamide-acrylate polymer, 10-60 parts of mixed phenol resin, 2-12 parts of solubilizer, 3-25 parts of dissolution-promoting resin, 0-1 part of resistance resin, 1-5 parts of infrared absorption dye and 1-2 parts of dye.

3. The method for preparing a UV-resistant ink CTP plate according to claim 2, characterized in that: The solubilizing agent is tetrahydrophthalic anhydride or alkoxybenzoic acid.

4. The method for preparing a UV-resistant ink CTP plate according to claim 2, characterized in that: The mixed phenol resin is a mixture of a polymer condensed from m-cresol and formaldehyde and a polymer condensed from p-cresol and formaldehyde, and the number average molecular weight of the mixed phenol resin is 6000-10000.

5. The method for preparing a UV-resistant ink CTP plate according to claim 2, characterized in that: The dissolution-promoting resin is an alkylphenol formaldehyde resin with a number average molecular weight of 3000-5500, and the dissolution-retarding resin is an alkylphenol formaldehyde resin with a number average molecular weight of 10000-12000.

6. The method for preparing a UV-resistant ink CTP plate according to claim 2, characterized in that: The infrared absorbing dye is a 830nm thermosensitive infrared absorbing cyanine dye.

7. The method for preparing a UV-resistant ink CTP plate according to claim 2, characterized in that: The dye is ethyl violet or Victoria blue.

8. The method for preparing a UV-resistant ink CTP plate according to claim 1, characterized in that: The plate base is an aluminum base plate.

9. The method for preparing a UV-resistant ink CTP plate according to claim 1, characterized in that: UV-resistant ink CTP plate consists of a base and an imaging coating.