Anti-fading printing ink for Bailey film printing and preparation method of anti-fading printing ink

Abstract

The invention relates to the technical field of water-based ink, and discloses anti-fading ink for Bailey film printing and a preparation method of the anti-fading ink for Bailey film printing. The water-resistant modified acrylate emulsion is prepared by taking butyl acrylate, methyl methacrylate, acrylic acid and an alkenylated fluorine-containing water-resistant monomer as raw materials under the action of a compound emulsifier and a compound initiator, firstly forming a pre-emulsion by utilizing the emulsifier through a pre-emulsion method, and then generating free radicals and initiating free radical polymerization reaction under the action of the initiator. The alkenylation fluorine-containing water-resistant monomer is prepared by taking perfluorobutyl ethyl alcohol, chloroethyl isocyanate and eugenol as raw materials through an ammonia esterification reaction and a substitution reaction; the anti-fading printing ink is excellent in water resistance, adhesive force and stability, is not easy to fade when meeting water or in a humid environment, and can meet the printing requirement of the Bailey film.

Description

Technical Field

[0001] This invention relates to the field of water-based ink technology, and in particular to a colorfast ink for printing with Peli film and its preparation method. Background Technology

[0002] Tetra Pouch is a packaging form for liquid dairy products and beverages, typically made of thermoplastic polyolefin multilayer co-extruded film. With increasing environmental awareness, water-based inks have gradually become one of the mainstream choices for printing Tetra Pouches. Water-based inks use water as a dispersant, have the advantages of low production costs, low emissions of volatile organic compounds, strong environmental protection, and a mild odor after printing, meeting market demand.

[0003] Water-based acrylic esters are a type of binder in inks, dispersing and adhering pigments to the printing substrate. They form the film-forming substance after ink drying and directly determine the ink's film-forming properties, printability, and overall performance. Water-based acrylic ester coatings exhibit excellent performance in terms of weather resistance, oxidation resistance, and stain resistance.

[0004] However, water-based acrylic binders have shortcomings. On the one hand, the thermoplastic polyolefin multilayer co-extruded film of Telibao has low surface energy, making it difficult for water-based inks to form an effective bond with Telibao, resulting in insufficient adhesion. Corona treatment of the polyolefin film surface is usually required. On the other hand, the presence of hydrophilic groups in water-based acrylics leads to poor water resistance. When exposed to water or in humid environments, the ink layer is penetrated by moisture, causing swelling and softening. This reduces the adhesion between the ink layer and the polyolefin substrate, making it easier for pigment particles to be carried away by external mechanical forces, resulting in color fading. This reduces the user experience and limits the application of water-based inks. Summary of the Invention

[0005] This invention proposes an anti-fading ink for printing on Baili film and its preparation method. The ink product is an environmentally friendly water-based ink with excellent water resistance, strong adhesion and stability. It effectively improves the problem of water-based inks fading easily when exposed to water and can meet the printing needs of Baili film.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A fade-resistant ink for printing on Baili film, the fade-resistant ink being composed of a water-resistant modified acrylic emulsion, pigments and additives, wherein the water-resistant modified acrylic emulsion is prepared by a pre-emulsification emulsion method using acrylic monomers and alkenylated fluorinated water-resistant monomers as raw materials.

[0008] The mass ratio of the alkenylated fluorinated water-resistant monomer to the acrylic monomer is 1.5-7:100.

[0009] A method for preparing a fade-resistant ink for printing on Peli film includes the following steps:

[0010] Preparation of water-resistant modified acrylate emulsion;

[0011] Add 8-15 parts by weight of pigment and 0.5-3 parts by weight of BYK-181 dispersant to deionized water, stir and disperse to prepare water-based color paste;

[0012] A water-based color paste, 0.1-2.5 parts by weight of tributyl phosphate defoamer, 0.1-1.5 parts by weight of LD-2002 leveling agent, and 10-15 parts by weight of isopropanol are added to 30-60 parts by weight of water-resistant modified acrylic emulsion. The mixture is then dispersed by high-speed shearing, and the pH value is adjusted to 8-9.5 to obtain a uniformly dispersed, colorfast ink.

[0013] Preferably, the water-resistant modified acrylic emulsion comprises the following raw materials in parts by weight:

[0014] 20-30 parts butyl acrylate;

[0015] 20-30 parts methyl methacrylate;

[0016] 2-3 parts acrylic acid;

[0017] 1-3 parts of alkenylated fluorinated water-resistant monomer;

[0018] 1-3.5 parts compound emulsifier;

[0019] 0.2-1.5 parts of composite initiator.

[0020] Preferably, the preparation method of the alkenylated fluorinated water-resistant monomer is as follows:

[0021] Under the action of an organotin catalyst, the hydroxyl group in 1 molar equivalent of perfluorobutyl ethyl alcohol undergoes an amino esterification reaction with the isocyanate group in chloroethyl isocyanate to obtain chloroethyl fluorinated intermediate.

[0022] Under the action of an alkaline catalyst, the chlorine substituent in 1 molar equivalent of chloroethyl fluorinated intermediate undergoes a substitution reaction with the phenolic hydroxyl group in 1 molar equivalent of eugenol to prepare an alkenylated fluorinated water-resistant monomer.

[0023] Preferably, the organotin catalyst is dibutyltin dilaurate or stannous octoate.

[0024] Preferably, the alkaline catalyst is anhydrous potassium carbonate or anhydrous sodium carbonate.

[0025] Preferably, the composite emulsifier is composed of sodium dodecyl sulfate and octylphenol polyoxyethylene ether in a mass ratio of 1:0.5-0.8.

[0026] Preferably, the composite initiator is composed of a water-soluble initiator and an oil-soluble initiator in a mass ratio of 1:0.5-1; the water-soluble initiator is ammonium persulfate or potassium persulfate; and the oil-soluble initiator is benzoyl peroxide or tert-butyl peroxide-2-ethylhexanoate.

[0027] Preferably, the pigment is any one of Permanent Orange G, Titanium Dioxide Type A, Permanent Red F6B, Phthalocyanine Blue BGS, and Phthalocyanine Green.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention synthesizes alkenylated fluorinated water-resistant monomers as functional modifying monomers. Water-resistant modified acrylate emulsions are prepared via a pre-emulsification emulsion method. These emulsions are then mixed and dispersed with pigments and additives to prepare colorfast inks. The rigid benzene rings and fluorinated groups in the alkenylated fluorinated water-resistant monomers effectively improve the water resistance of water-based inks, preventing water molecules from invading the ink layer in humid environments, causing swelling, loosening of the film structure, and decreased adhesion to the polyolefin packaging substrate. This leads to pigment migration, color fading, ink bubbling, and peeling, negatively impacting the user experience. Furthermore, the aminomethyl ester and phenyl ether bonds in the alkenylated fluorinated water-resistant monomers can form hydrogen bonds with the corona-treated polyolefin packaging surface, effectively improving adhesion and firmly adhering the ink to the packaging surface, thus enhancing the durability of printed materials.

[0030] The test results show that the colorfast ink prepared by this invention does not stain the water at all after being soaked in water for 24 hours, and the ink layer does not fade at all. This indicates that the ink layer is not easy to fade when exposed to water or in a humid environment, and has excellent water resistance. The adhesion strength is ≥95%, and the adhesion is strong. No delamination, gelation, or flocculation occurred within three months, and the stability performance is excellent, meeting the printing requirements of Baili film. Detailed Implementation

[0031] In the prior art, fluoromethacrylates, such as dodecafluoroheptyl methacrylate, are commonly used to modify water-based inks with acrylate as a binder. Although this effectively improves the water resistance of the acrylate binder, it is insufficient in terms of adhesion. The alkenylated fluorinated water-resistant monomer designed and synthesized in this invention overcomes the defects of the prior art, so that the prepared acrylate ink can not only maintain excellent water resistance, but also form an effective bond with polyolefin-type polyacrylate, and has strong adhesion.

[0032] Experimental Example 1:

[0033] The mechanism for synthesizing alkenylated fluorinated water-resistant monomers is as follows:

[0034] Under the action of dibutyltin dilaurate, the hydroxyl group in 1 molar equivalent of perfluorobutyl ethyl alcohol undergoes an amino esterification reaction with the isocyanate group in chloroethyl isocyanate to prepare chloroethyl fluorinated intermediate.

[0035] In the presence of anhydrous potassium carbonate, the chlorine substituent in 1 molar equivalent of chloroethyl fluorinated intermediate undergoes a substitution reaction with the phenolic hydroxyl group in 1 molar equivalent of eugenol to prepare an alkenylated fluorinated water-resistant monomer.

[0036] The chemical structural formula of the alkenylated fluorinated water-resistant monomer is as follows:

[0037] ;

[0038] A method for preparing alkenylated fluorinated water-resistant monomers includes the following steps:

[0039] 2.5 g of perfluorobutyl ethyl alcohol was added to 30 mL of tetrahydrofuran and mixed evenly. Nitrogen gas was introduced, 1 g of chloroethyl isocyanate was added and mixed evenly. 0.05 g of dibutyltin dilaurate was added, the temperature was raised to 60 °C, and the reaction was maintained at this temperature for 5 h. The mixture was then cooled to room temperature, tetrahydrofuran was removed by vacuum distillation, and the mixture was washed with deionized water and dried to obtain the chloroethyl fluorinated intermediate.

[0040] 3.7 g of chloroethyl fluorinated intermediate was added to 50 mL of dimethyl sulfoxide and mixed thoroughly. Nitrogen gas was introduced, and 1.64 g of eugenol and 0.2 g of anhydrous potassium carbonate were added and mixed thoroughly. The temperature was raised to 65 °C and the reaction was maintained for 8 h. The mixture was filtered, washed with saturated brine, and dried with anhydrous sodium sulfate to obtain the alkenylated fluorinated water-resistant monomer.

[0041] The 1H NMR characterization results of the alkenylated fluorinated water-resistant monomer are as follows:

[0042] 1 H NMR (400MHz, DMSO-D6, δ, ppm): 2.23-2.34(m, 2H), 3.31-3.33(d, 2H), 3.51-3.54(m, 2H), 3.84(s, 3H), 4.14- 4.15(t, 2H), 4.20-4.23(t, 2H), 5.03-5.15(m, 2H), 5.17-5.20(t, 1H), 5.88-5.98(m, 1H), 6.73-6.82(m, 3H).

[0043] Experimental Example 2:

[0044] Water-resistant modified acrylic emulsion is prepared by using butyl acrylate, methyl methacrylate, acrylic acid, and alkenylated fluorinated water-resistant monomers as raw materials. Under the action of composite emulsifiers and composite initiators, the pre-emulsification emulsion method is used to first form a pre-emulsion using emulsifiers, and then generate free radicals under the action of initiators to initiate a free radical polymerization reaction.

[0045] Water-resistant modified acrylic emulsion a, comprising the following raw materials in parts by weight:

[0046] 25 parts butyl acrylate;

[0047] 25 parts methyl methacrylate;

[0048] 2 parts acrylic acid;

[0049] 1 part of alkenylated fluorinated water-resistant monomer;

[0050] Three parts of composite emulsifier (sodium dodecyl sulfate and octylphenol polyoxyethylene ether, with a mass ratio of 1:0.65);

[0051] 1 part of a composite initiator (ammonium persulfate and benzoyl peroxide in a mass ratio of 1:1);

[0052] 0.3 parts sodium bicarbonate;

[0053] 80 portions of deionized water;

[0054] A method for preparing a water-resistant modified acrylic emulsion includes the following steps:

[0055] 65% of the composite emulsifier, 5% of the composite initiator, sodium bicarbonate and alkenylated fluorinated water-resistant monomer, butyl acrylate, methyl methacrylate, acrylic acid and deionized water were added sequentially to the pre-emulsification tank. Under normal temperature conditions, the stirring speed was set to 2000 rpm and the mixture was stirred and dispersed for 30 min to obtain the pre-emulsion.

[0056] Add the remaining composite emulsifier to the polymerization reactor, set the stirring speed to 250 rpm, raise the temperature to 70°C, add the remaining initiator, raise the temperature to 80°C, add 20% of the pre-emulsion, keep warm for 1 hour, add the remaining pre-emulsion dropwise using a constant pressure funnel, control the dropwise addition time to 2.5 hours, after the dropwise addition is completed, raise the temperature to 85°C again, keep warm for 1 hour, cool down to room temperature, filter, and obtain water-resistant modified acrylic emulsion a;

[0057] The only difference between the preparation method of water-resistant modified acrylate emulsion b and the preparation method of water-resistant modified acrylate emulsion a is that 2 parts by weight of alkenylated fluorinated water-resistant monomer are used instead of 1 part by weight of alkenylated fluorinated water-resistant monomer.

[0058] The only difference between the preparation method of water-resistant modified acrylate emulsion c and the preparation method of water-resistant modified acrylate emulsion a is that 3 parts by weight of alkenylated fluorinated water-resistant monomer are used instead of 1 part by weight of alkenylated fluorinated water-resistant monomer.

[0059] The only difference between the preparation method of acrylate emulsion and the preparation method of water-resistant modified acrylate emulsion a is that the alkenylated fluorinated water-resistant monomer is not used.

[0060] The only difference between the preparation method of fluorinated acrylate emulsion and the preparation method of water-resistant modified acrylate emulsion a is that 1 part by weight of dodecafluoroheptyl methacrylate is used instead of 1 part by weight of alkenylated fluorinated water-resistant monomer.

[0061] Example 1:

[0062] A type of colorfast ink a for printing on Peli film comprises the following raw materials in parts by weight:

[0063] 30 parts of water-resistant modified acrylic emulsion a;

[0064] 10 parts Phthalocyanine Blue BGS;

[0065] 2 parts tributyl phosphate defoamer;

[0066] 2.5 parts BYK-181 dispersant;

[0067] 1 part LD-2002 leveling agent;

[0068] 15 parts isopropanol;

[0069] 2 parts ammonia water;

[0070] 20 portions of deionized water;

[0071] A method for preparing a fade-resistant ink a for printing on Peli film includes the following steps:

[0072] Phthalocyanine Blue BGS pigment, BYK-181 dispersant and deionized water were stirred at 200 rpm for 5 min, and then the speed was increased to 2000 rpm and dispersed for 30 min to obtain an aqueous color paste.

[0073] According to the formula dosage, water-based color paste, tributyl phosphate defoamer, LD-2002 leveling agent, and isopropanol were added to water-resistant modified acrylic emulsion a. The rotation speed was set to 3000 rpm, and the mixture was dispersed at high speed by shearing for 1 hour. Ammonia water was added to adjust the pH value to 9, and the mixture was discharged to obtain a uniformly dispersed colorfast ink a.

[0074] Example 2:

[0075] The only difference between the preparation method of the colorfast ink b and the preparation method of the colorfast ink a is that the water-resistant modified acrylic emulsion b is used instead of the water-resistant modified acrylic emulsion a.

[0076] Example 3:

[0077] The only difference between the preparation method of colorfast ink c and the preparation method of colorfast ink a is that water-resistant modified acrylic emulsion c is used instead of water-resistant modified acrylic emulsion a.

[0078] Comparative Example 1:

[0079] The only difference between the preparation method of ink a and the preparation method of colorfast ink a is that acrylic emulsion is used instead of water-resistant modified acrylic emulsion a.

[0080] Comparative Example 2:

[0081] The only difference between the preparation method of ink b and the preparation method of anti-fading ink a is that fluorinated acrylate emulsion is used instead of water-resistant modified acrylate emulsion a.

[0082] Performance testing:

[0083] The PE film was cleaned with deionized water and ethanol to remove surface impurities. The dried PE film was then placed on a corona treatment machine with a power of 1.5W and a corona treatment time of 30s to obtain a corona-treated PE film.

[0084] I. Water Resistance Test of Ink

[0085] Anti-fading ink was applied to a corona-treated PE film. After the ink layer was completely dry, half of the ink layer was immersed in water and the other half was not. After 24 hours, the water staining was observed. The film was then removed, and the ink layer immersed in water was compared with the unimmersed ink layer to evaluate the water resistance of the ink. The results are shown in Table 1.

[0086] Table 1 Test results of water resistance of ink

[0087]

[0088] II. Ink Adhesion Test

[0089] Anti-fading ink was applied to a corona-treated PE film. After the ink layer was completely dry, 3M 600 tape was adhered to the coating, pressed firmly, and then peeled off. The tape was held at a 60° angle to the film, and the tape was slowly pulled off. A semi-transparent 20mm x 20mm grid paper was used to cover the area where the ink coating was peeled off. The number of grids occupied by the ink layer and the number of grids of the removed ink layer were counted. The adhesion strength of the ink was calculated using the formula: A = [A1 / (A1+A2)] × 100%, where A is the ink adhesion strength, A1 is the number of grids of the ink layer, and A2 is the number of grids of the removed ink layer. This was used to evaluate the ink adhesion. The results are shown in Table 2.

[0090] Table 2 Test results of ink adhesion

[0091]

[0092] III. Testing of ink stability

[0093] The ink was placed at room temperature in a sealed container and its appearance was observed. If phenomena such as layering, gelation, or flocculation occurred within three months, it indicated that the ink was unstable. The test results are shown in Table 3.

[0094] Table 3 Test results of ink stability performance

[0095]

[0096] The following conclusions can be drawn from the performance test results:

[0097] The ink modified with the alkenylated fluorinated water-resistant monomer synthesized by this invention has excellent water resistance and effectively inhibits the swelling or reemulsification of the ink after it comes into contact with water, which would cause the ink to fade.

[0098] The ink modified with the alkenylated fluorinated water-resistant monomer synthesized in this invention exhibits significantly better adhesion than the ink modified with dodecafluoroheptyl methacrylate. The alkenylated fluorinated water-resistant monomer contains groups that form hydrogen bonds with the surface of the corona-treated PE film, thus resulting in stronger adhesion. Furthermore, the anti-fading ink prepared in this invention demonstrates excellent stability.

Claims

1. A fade-resistant ink for printing on Peli film, characterized in that, The colorfast ink is composed of water-resistant modified acrylic emulsion, pigments and additives. The water-resistant modified acrylic emulsion is prepared by a pre-emulsification emulsion method using acrylic monomers and alkenylated fluorinated water-resistant monomers as raw materials. The chemical structural formula of the alkenylated fluorinated water-resistant monomer is: ； The mass ratio of the alkenylated fluorinated water-resistant monomer to the acrylic monomer is 1.5-7:

100.

2. A method for preparing the anti-fading ink for Peli film printing as described in claim 1, characterized in that, Includes the following steps: Preparation of water-resistant modified acrylate emulsion; Add 8-15 parts by weight of pigment and 0.5-3 parts by weight of BYK-181 dispersant to deionized water, stir and disperse to prepare water-based color paste; A water-based color paste, 0.1-2.5 parts by weight of tributyl phosphate defoamer, 0.1-1.5 parts by weight of LD-2002 leveling agent, and 10-15 parts by weight of isopropanol are added to 30-60 parts by weight of water-resistant modified acrylic emulsion. The mixture is then dispersed by high-speed shearing, and the pH value is adjusted to 8-9.5 to obtain a uniformly dispersed, colorfast ink.

3. The method for preparing a fade-resistant ink for printing on Peli film according to claim 2, characterized in that, The water-resistant modified acrylic emulsion comprises the following raw materials in parts by weight: 20-30 parts butyl acrylate; 20-30 parts methyl methacrylate; 2-3 parts acrylic acid; 1-3 parts of alkenylated fluorinated water-resistant monomer; 1-3.5 parts compound emulsifier; 0.2-1.5 parts of composite initiator.

4. The method for preparing a fade-resistant ink for printing on Peli film according to claim 3, characterized in that, The preparation method of the alkenylated fluorinated water-resistant monomer is as follows: Under the action of an organotin catalyst, the hydroxyl group in 1 molar equivalent of perfluorobutyl ethyl alcohol undergoes an amino esterification reaction with the isocyanate group in chloroethyl isocyanate to obtain chloroethyl fluorinated intermediate. Under the action of an alkaline catalyst, the chlorine substituent in 1 molar equivalent of chloroethyl fluorinated intermediate undergoes a substitution reaction with the phenolic hydroxyl group in 1 molar equivalent of eugenol to prepare an alkenylated fluorinated water-resistant monomer.

5. The method for preparing a fade-resistant ink for printing on Peli film according to claim 4, characterized in that, The organotin catalyst is dibutyltin dilaurate or stannous octoate.

6. The method for preparing a fade-resistant ink for printing on Peli film according to claim 4, characterized in that, The alkaline catalyst is anhydrous potassium carbonate or anhydrous sodium carbonate.

7. The method for preparing a fade-resistant ink for printing on Peli film according to claim 3, characterized in that, The composite emulsifier is composed of sodium dodecyl sulfate and octylphenol polyoxyethylene ether in a mass ratio of 1:0.5-0.

8.

8. The method for preparing a fade-resistant ink for printing on Peli film according to claim 3, characterized in that, The composite initiator is composed of a water-soluble initiator and an oil-soluble initiator in a mass ratio of 1:0.5-1; the water-soluble initiator is ammonium persulfate or potassium persulfate; the oil-soluble initiator is benzoyl peroxide or tert-butyl peroxide-2-ethylhexanoate.

9. The method for preparing a fade-resistant ink for printing on Peli film according to claim 2, characterized in that, The pigment is any one of Permanent Orange G, Titanium Dioxide Type A, Permanent Red F6B, Phthalocyanine Blue BGS, and Phthalocyanine Green.

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