Printing image eliminating liquid and preparation method thereof

Abstract

The application relates to the technical field of graphic printing, and particularly discloses a printing graphic eliminating liquid and a preparation method thereof. The printing graphic eliminating liquid is prepared from raw materials containing solvent oil, pure water, an emulsifier, a bacteriostatic agent, a thickening agent, a defoaming agent, oleic acid, citric acid and triethanolamine by weight, and the preparation method comprises the following steps: adding the solvent oil, the pure water, the bacteriostatic agent, the thickening agent, the defoaming agent, the oleic acid, the citric acid and the triethanolamine into a high-shear emulsifier, stirring to form a uniform and stable mixed liquid, then adding the emulsifier into the mixed liquid, and stirring to obtain the printing graphic eliminating liquid. The printing graphic eliminating liquid can be used for eliminating graphic traces on the surface of a CTP plate material, has the advantages of good eliminating effect and high eliminating efficiency, and the preparation method has the advantages that the prepared printing graphic eliminating liquid is more uniform and stable and is not prone to stratification.

Description

Technical Field

[0001] This application relates to the technical field of graphic printing, and more specifically, to a printing graphic removal liquid and its preparation method. Background Technology

[0002] With the continuous development of CTP, plate technology has increasingly become a key research focus in the industry. Computer-to-plate (CTP) refers to the process of directly scanning and recording image and text information onto a plate using a computer, without the need for film. After development, the plate is ready for printing. Such plates are called CTP plates. Among them, wash-free CTP plates are those that do not require chemical developing solutions after plate making; they can be directly printed after rinsing with water or without any other treatment. Wash-free CTP plates are developed on the printing wash machine, significantly shortening the plate-making process and reducing the need for plate-making machines. This not only saves costs but also significantly increases production capacity, meeting users' high demands for efficiency and profit.

[0003] Generally, after printing images and text, no-wash CTP plates will leave printed marks on their surface, which people can see from the printed content. If the printed content does not involve confidential information, it is not necessary to remove these marks. However, if the printed content involves confidential information, the printed marks on the CTP plate surface must be destroyed for confidentiality purposes.

[0004] In related technologies, the following two methods are generally used to eliminate graphic traces on the surface of CTP plates: 1. Using a shredder to shred the CTP plate, but graphic traces can still be seen on the shredded CTP plate, and cannot achieve complete confidentiality; 2. Using a grinding method to burn and grind the surface of the CTP plate to destroy the graphic traces on the surface of the CTP plate, but this confidentiality treatment method still cannot completely destroy the graphic traces, and some graphic traces will remain on the surface of the CTP plate. Moreover, this treatment method is not environmentally friendly and is extremely costly.

[0005] Therefore, there is an urgent need to develop a product that can completely eliminate graphic marks on the surface of no-rinse CTP plates. Summary of the Invention

[0006] In order to effectively and completely eliminate the graphic marks on the surface of a no-rinse CTP plate, this application provides a printing graphic removal liquid and its preparation method.

[0007] In a first aspect, this application provides a print removal liquid, which adopts the following technical solution:

[0008] A print erasing liquid, made from raw materials comprising the following parts by weight:

[0009]

[0010]

[0011] By adopting the above technical solution, solvent oil and pure water are used as the main components of the removal liquid. Combined with emulsifiers and other additives, a relatively viscous, milky white removal liquid can be prepared. When the removal liquid is evenly applied to the surface of the CTP plate, it can effectively and completely eliminate the graphic marks on the surface of the CTP plate.

[0012] Generally, CTP plates have a photosensitive emulsion on their surface, and the graphic marks are located on the photosensitive emulsion layer. The photosensitive emulsion usually contains phenolic resin. In this application, solvent oil is used to effectively dissolve and corrode the phenolic resin to remove the graphic marks from the surface of the CTP plate. Furthermore, under acidic conditions, oleic acid can react with phenolic resin, promoting the dissolution and corrosion of the phenolic resin by the solvent oil. In this application, oleic acid and solvent oil are combined to further accelerate the dissolution and corrosion of the phenolic resin, effectively eliminating the graphic marks on the surface of the CTP plate.

[0013] In addition, triethanolamine, while acting as an emulsifier, has excellent penetrating properties. During the corrosion of phenolic resin, triethanolamine penetrates into the phenolic resin and, under the action of citric acid, promotes the reaction between the phenolic resin and triethanolamine, so that triethanolamine self-cures on the surface of the corroded phenolic resin and forms a film, which facilitates the removal of the corroded phenolic resin from the CTP plate surface and reduces damage to the aluminum substrate on the CTP plate surface.

[0014] Compared to traditional techniques that involve crushing or grinding CTP plates to destroy graphic traces for confidentiality purposes, this application uses an erasure liquid to chemically corrode the graphic traces on the CTP plate surface. The traces are then completely removed by rinsing or wiping with water. This method offers a simple, quick, and efficient way to completely eliminate graphic traces from the CTP plate surface.

[0015] Preferably, the thickener is one or more of corn flour, potato starch dextrin, and xanthan gum.

[0016] By adopting the above technical solution, corn flour and potato starch dextrin can effectively increase the viscosity of the printing image removal liquid, allowing the removal liquid to be applied to the CTP plate surface for a longer period of time. This facilitates the dissolution and corrosion of the photosensitive emulsion on the CTP plate surface by the removal liquid, thereby improving the removal power of image marks. In addition, the xanthan gum used in this application as a thickener can provide a smooth and leveling effect to the removal liquid, ensuring that the removal liquid can quickly and completely cover the CTP plate surface during the application process, eliminating the need for repeated application and making the operation simple and quick. Furthermore, since this application uses corn flour and potato starch dextrin, especially since both contain protein, antibacterial agents are added for sterilization, antibacterial and preservative treatment to prevent bacterial growth and maintain the excellent removal performance of the removal liquid.

[0017] Preferably, the mass ratio of xanthan gum to potato starch dextrin is 1:4.

[0018] By adopting the above technical solution, when the mass ratio of xanthan gum to corn flour is 1:4, the resulting elimination liquid has better viscosity and is smoother, making it easier and faster to apply.

[0019] Preferably, the emulsifier is one or more of AEO 90, MP9 and Tween 80.

[0020] Preferably, the solvent oil is a high-boiling-point solvent oil, and the solvent oil is one or a combination of several of S150, D80 and D100.

[0021] By adopting the above technical solution, the high-boiling-point solvent oil used in this application is heated before use to reduce bacteria and thus reduce the impact of bacteria on potato starch dextrin. If a low-boiling-point solvent oil is used, bacteria will grow, affecting the removal performance of the removal solution. The high-boiling-point solvent oil, while serving as a solvent for the removal solution, also plays a role in dissolving and corroding phenolic resin, so that the removal solution can completely remove the graphic marks on the surface of the CTP plate.

[0022] Preferably, the antibacterial agent is one or more of the following: hydroxyphenyl esters, benzoic acid, potassium sorbate, and sodium benzoate.

[0023] Preferably, the mass ratio of triethanolamine, oleic acid and citric acid is 1:3:3.

[0024] By adopting the above technical solution, since oleic acid can react with phenolic resin, and under the promoting effect of citric acid, the self-curing film-forming reaction of triethanolamine and phenolic resin is further accelerated. The three work together to quickly form a film that detaches from the CTP plate surface while eliminating graphic traces, thereby reducing damage to the aluminum substrate of the CTP plate.

[0025] Furthermore, the combination of oleic acid and solvent oil can effectively dissolve and corrode phenolic resin. At the same time, oleic acid can promote the reaction between triethanolamine and phenolic resin, accelerate the penetration and film formation rate of triethanolamine, so that triethanolamine can form a film on the surface of phenolic resin more quickly, and make the graphic marks more efficiently and completely eliminated from the surface of CTP plate.

[0026] Secondly, this application provides a method for preparing a print removal liquid, which adopts the following technical solution:

[0027] A method for preparing a print erasing solution includes the following steps:

[0028] Solvent oil, pure water, antibacterial agent, thickener, defoamer, oleic acid, citric acid and triethanolamine are mixed and added to a high-shear emulsifier. The mixture is stirred at 800-1000 rpm for 25-30 minutes to form a homogeneous and stable mixture. Then the emulsifier is added to the mixture and stirred at 800-1000 rpm for 25-30 minutes to obtain the printing image removal solution.

[0029] By adopting the above technical solution, this application uses a high-shear emulsifier to stir and disperse other raw materials and additives, so that the molecular particle size of each additive is similar and the dispersion is uniform, so that the raw materials are mixed evenly and do not separate into layers. Then, the emulsifier is added for stirring and dispersion, making the prepared printing image removal liquid more uniform and stable and less prone to separation.

[0030] In summary, this application has the following beneficial effects:

[0031] 1. In this application, solvent oil can effectively dissolve and corrode phenolic resin to remove graphic traces from the surface of CTP board; and under acidic conditions, oleic acid can react with phenolic resin to promote the dissolution and corrosion of phenolic resin by solvent oil. In this application, oleic acid and solvent oil are combined to further accelerate the dissolution and corrosion of phenolic resin and efficiently eliminate graphic traces on the surface of CTP board.

[0032] 2. Triethanolamine, while acting as an emulsifier, also has excellent penetrating properties. During the corrosion of phenolic resin, triethanolamine penetrates into the phenolic resin and, under the action of citric acid, promotes the reaction between the phenolic resin and triethanolamine, so that triethanolamine self-cures on the surface of the corroded phenolic resin and forms a film. This facilitates the removal of the corroded phenolic resin from the CTP plate surface and reduces damage to the aluminum substrate on the CTP plate surface.

[0033] 3. The high-boiling-point solvent oil used in this application is heated before use to reduce the bacteria in it, thereby reducing the impact of bacteria on potato starch dextrin; at the same time, the high-boiling-point solvent oil, while serving as a solvent for the removal liquid, also plays a role in dissolving and corroding phenolic resin, so that the removal liquid can completely remove the graphic marks on the surface of the CTP plate.

[0034] 4. In this application, a high-shear emulsifier is used to stir and disperse other raw materials and additives, so that the molecular particle size of each additive is similar and the dispersion is uniform, so that the raw materials are mixed evenly and do not separate into layers. Then, the emulsifier is added to stir and disperse, making the prepared printing image removal liquid more uniform and stable and less prone to separation. Attached Figure Description

[0035] Figure 1 This is a comparison diagram showing the effect of the removal liquid in Embodiment 2 of this application in removing graphic marks on the surface of CTP plates.

[0036] Figure 2 This is a comparison diagram showing the effect of rinsing before and after using the rinsing solution to remove graphic marks on the surface of a CTP plate in Embodiment 2 of this application.

[0037] Figure 3 This is a schematic diagram of different thicknesses of the anti-removal liquid layer applied to the surface of the CTP plate in Embodiment 2 of this application;

[0038] Figure 4 This is a schematic diagram illustrating the effect of different thicknesses of the removal liquid layer on the removal of graphic marks on the surface of CTP plates in Embodiment 2 of this application;

[0039] Figure 5 This is a schematic diagram of the elimination solution of Comparative Example 1 of this application during use;

[0040] Figure 6 This is an image showing the effect of the removal solution of Comparative Example 1 of this application on the removal of graphic traces on the surface of a CTP plate. Detailed Implementation

[0041] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that: in the following embodiments, unless otherwise specified, the conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer, and the raw materials used in the following embodiments can be obtained from commercially available sources unless otherwise specified.

[0042] Example

[0043] Example 1

[0044] A method for preparing a print erasing solution includes the following steps:

[0045] Weigh out 40 parts of high-boiling-point solvent oil D80, 45 parts of pure water, 0.3 parts of antibacterial agent benzoic acid, 2.0 parts of thickener potato starch dextrin, 0.06 parts of defoamer, 2 parts of oleic acid, 2 parts of citric acid and 0.5 parts of triethanolamine respectively, mix and add to a high-shear emulsifier, stir at 1000 rpm for 25 min to form a homogeneous and stable mixture, then add emulsifier AEO 90 to the mixture and stir at 1000 rpm for 25 min to obtain a milky white viscous printing image removal solution.

[0046] Example 2

[0047] A method for preparing a print erasing solution includes the following steps:

[0048] Weigh out 43 parts of high-boiling-point solvent oil S150, 42 parts of pure water, 0.5 parts of antibacterial agent sodium benzoate, 2.5 parts of thickener, 0.1 parts of defoamer, 3 parts of oleic acid, 3 parts of citric acid and 1.0 parts of triethanolamine respectively, mix and add to a high-shear emulsifier, stir at 800 rpm for 30 min to form a homogeneous and stable mixture, then add emulsifier Tween 80 to the mixture and stir at 800 rpm for 30 min to obtain a milky white viscous printing image removal solution;

[0049] The thickener consists of 2.0 parts potato starch dextrin and 0.5 parts xanthan gum.

[0050] Example 3

[0051] A method for preparing a print erasing solution includes the following steps:

[0052] Weigh out 46 parts of high-boiling-point solvent oil D100, 40 parts of pure water, 0.6 parts of antibacterial agent potassium sorbate, 3.0 parts of thickener corn flour, 0.12 parts of defoamer, 4 parts of oleic acid, 4 parts of citric acid and 1.5 parts of triethanolamine respectively, mix and add to a high-shear emulsifier, stir at 800 rpm for 30 min to form a homogeneous and stable mixture, then add emulsifier MP9 to the mixture and stir at 800 rpm for 30 min to obtain a milky white viscous printing image removal solution.

[0053] Example 4

[0054] A method for preparing a print erasing solution includes the following steps:

[0055] Weigh out 43 parts of high-boiling-point solvent oil S150, 42 parts of pure water, 0.5 parts of antibacterial agent sodium benzoate, 2.5 parts of thickener, 0.1 parts of defoamer, 2 parts of oleic acid, 3 parts of citric acid and 1.0 parts of triethanolamine respectively, mix and add to a high-shear emulsifier, stir at 800 rpm for 30 min to form a homogeneous and stable mixture, then add emulsifier Tween 80 to the mixture and stir at 800 rpm for 30 min to obtain a milky white viscous printing image removal solution;

[0056] The thickener consists of 2.0 parts potato starch dextrin and 0.5 parts xanthan gum.

[0057] Table 1: Composition ratio of printing image erasure solution in Examples 1-4

[0058]

[0059]

[0060] Comparative Example

[0061] Comparative Example 1

[0062] The disinfectant used was Kodak Clean, a product purchased from the market.

[0063] Comparative Example 2

[0064] Compared to Example 2, no triethanolamine was added in Comparative Example 2.

[0065] Comparative Example 3

[0066] Compared to Example 2, no oleic acid and citric acid were added in Comparative Example 3.

[0067] Comparative Example 4

[0068] Compared to Example 2, Comparative Example 4 did not contain potato starch dextrin or xanthan gum.

[0069] Performance testing

[0070] The printing image erasing solutions prepared in Examples 1-4 and Comparative Examples 1-4 were subjected to the following performance tests. The specific test data are shown in Table 2:

[0071] Elimination effect: The printing image removal liquids prepared in Examples 1-4 and Comparative Examples 1-4 were applied in equal amounts to the surface of CTP plates with image marks. Then, a coater was used to evenly coat the image marks with the removal liquid, resulting in a coating thickness of 4 mm. After a period of time, the coating of the removal liquid became translucent. After testing, when the image marks had completely disappeared and turned white, the removal liquid was rinsed off with water or wiped with a sponge and then rinsed to observe the elimination effect. The time taken during the entire elimination process was defined as the elimination time.

[0072] Table 2: Test data of the print removal liquids of Examples 1-4 and Comparative Examples 1-4

[0073]

[0074] As can be seen from Examples 1-4 and Comparative Examples 1-4, and Table 2, the printing image removal liquid prepared in this application is a milky white, viscous liquid with good fluidity, which allows it to be easily applied to the surface of CTP plates and adheres stably to the CTP surface, providing sufficient time to remove image marks. Furthermore, in Example 1, the mass ratio of triethanolamine to oleic acid was 1:2. Experiments showed that while this method effectively removed image marks, it had poor film-forming properties, making it difficult to quickly remove the removal liquid from the CTP plate surface after removal. In contrast, the mass ratio of triethanolamine, oleic acid, and citric acid used in Example 2 was 1:3:3, resulting in better removal effects and excellent film-forming properties, allowing for rapid detachment from the CTP plate surface and reducing damage to the aluminum substrate of the CTP plate.

[0075] As can be seen from Example 2 and Comparative Example 2, and Table 2, Comparative Example 2 did not add triethanolamine, resulting in poor film-forming properties of the removal solution, making it difficult to remove from the CTP plate surface and requiring excessively long removal time. Furthermore, experiments revealed that the absence of triethanolamine for film formation easily damages the aluminum substrate of the CTP plate.

[0076] Combining Example 2 and Comparative Example 3 with Table 2, it can be seen that Comparative Example 3 did not add oleic acid and citric acid. The experiment found that, in particular, the time to remove graphic marks on the surface of CTP plates increased, the removal effect of the removal liquid was poor, and the cleaning power of the graphic marks became worse.

[0077] Combining Example 2 and Comparative Example 4 with Table 2, it can be seen that Comparative Example 4 did not add potato starch dextrin and xanthan gum. It is obvious that the viscosity of the prepared removal liquid is small and the stickiness is also very small, making it difficult to stably adhere to the surface of CTP board to remove graphic marks.

[0078] Combination Figure 1 and Figure 5as well as Figure 6 It is evident that the eliminator prepared in this application has an excellent eliminating effect, and Figure 5 In comparison, the removal solution in Example 1 showed poor removal effect and could not completely remove graphic traces from the CTP plate surface. Furthermore, from... Figure 2 As can be seen, the removal solution in Comparative Example 1 has poor viscosity and produces a lot of foam, making it difficult for the removal solution to completely soak in and remove the graphic traces.

[0079] Combination Figure 1 and Figure 2 It is evident that the removal solution prepared in Example 2 of this application can completely eliminate graphic traces on the surface of CTP plates. Figure 2 It can be seen from this that Figure 2 The diagram on the left shows a scenario where the disinfectant has already been used. At this point, simply rinsing with water is sufficient. Figure 2 The text and image traces in the image have been completely eliminated. Figure 2 The image on the right shows the process of rinsing with water. It is clear from the image that most of the graphic traces have been washed away. This demonstrates that the removal solution of this application can completely remove graphic traces, and the operation is simple and the removal efficiency is high.

[0080] Figure 3 and Figure 4 It was found that using different thicknesses of the eraser coating to remove graphic marks on the CTP board surface revealed that while a thinner coating resulted in slightly less effective removal, the impact was minimal, and the marks were still completely removed. However, excessively thick coatings easily left a white residue on the CTP board surface, negatively impacting the user experience. Furthermore, a thinner coating became semi-transparent after use, making it easier for users to observe the removal effect.

[0081] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A printing image erasing liquid, characterized in that: Made from the following ingredients in parts by weight: Solvent oil 40-46 parts; 40-45 parts pure water; Emulsifier 3.0-4.0 parts; Antibacterial agent 0.3-0.6 parts; Thickener 2.0-3.0 parts; Defoamer 0.06-0.12 parts; 2-4 parts oleic acid; Citric acid 2-4 parts; Triethanolamine 0.5-1.5 parts; The solvent oil is a high-boiling-point solvent oil, and the solvent oil is one of S150, D80 and D100.

2. The printing image erasing liquid according to claim 1, characterized in that: The thickener is one or more of corn flour, potato starch dextrin, and xanthan gum.

3. The printing image erasing liquid according to claim 2, characterized in that: The mass ratio of xanthan gum to potato starch dextrin is 1:

4.

4. The printing image erasing liquid according to claim 1, characterized in that: The emulsifier is one or more of AEO 90, MP9 and Tween 80.

5. The printing image erasing liquid according to claim 1, characterized in that: The antibacterial agent is one or more of the following: hydroxyphenyl esters, benzoic acid, potassium sorbate, and sodium benzoate.

6. The printing image erasing liquid according to claim 1, characterized in that: The mass ratio of triethanolamine, oleic acid, and citric acid is 1:3:

3.

7. A method for preparing a print removal liquid as described in any one of claims 1-6, characterized in that: Includes the following steps: Solvent oil, pure water, antibacterial agent, thickener, defoamer, oleic acid, citric acid and triethanolamine are mixed and added to a high-shear emulsifier. The mixture is stirred at 800-1000 rpm for 25-30 minutes to form a homogeneous and stable mixture. Then the emulsifier is added to the mixture and stirred at 800-1000 rpm for 25-30 minutes to obtain the printing image removal solution.

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