Water-based composite high-temperature printing ink and preparation process thereof

Abstract

The invention relates to the technical field of water-based ink, in particular to water-based composite high-temperature ink and a preparation process thereof. The problems that water-based ink is poor in high temperature resistance, insufficient in adhesive force, low in drying speed, uneven in printing and poor in water resistance are solved. The modified acrylic resin is prepared as a binder, so that the water-based composite high-temperature ink has good high-temperature resistance; by controlling the grinding temperature, the grinding fineness and the use amount of the wetting agent, the adhesion fastness of the water-based ink is improved; by controlling the proportion of water and alcohol solvents in the solvent and the type of the alcohol solvents, the non-uniform phenomena such as stripes and spots in the printing process are reduced, and the printing ink can be uniformly printed on a printing stock; by controlling the type and dosage of the chain extender, the crosslinking degree and tightness of a molecular chain are improved by utilizing the chain extender, and the water resistance of the water-based ink is improved.

Description

Technical Field

[0001] The invention relates to the technical field of water-based inks, in particular to a water-based composite high-temperature ink and a preparation process thereof. Background Art

[0002] With the continuous development of modern industry, the printing industry has become increasingly important in production. The development level of the printing industry is often one of the important indicators of a country's industrialization and modernization. As ink technology continues to develop towards high technology, people's environmental awareness is also increasing. The development of environmentally friendly inks is an issue that must be considered in the future development of inks. Since the 1970s, developed countries such as Western Europe and North America have launched nationwide activities for environmental governance and environmental protection, and environmental protection departments and industrial departments of various countries have also successively formulated relevant laws and regulations. Against this background, water-based inks came into being.

[0003] People often come into contact with food packaging prints in their daily lives. With the improvement of living standards and environmental awareness, people have put forward higher requirements for food packaging prints, requiring that the printing inks used in the high-temperature disinfection process do not fall off, do not fade, and do not release toxic substances. Therefore, the demand for high-temperature inks is increasing. Traditional high-temperature inks mostly use solvent-based resins, which have problems such as environmental pollution and harm to the human body. Although water-based high-temperature inks have reduced environmental pollution to a certain extent, their high-temperature resistance and adhesion still need to be improved.

[0004] Chinese patent CN101717596B discloses a water-based ink for high-adhesion film packaging printing and its preparation method, which is prepared from the following raw materials by weight: 10%-30% water, 5%-25% alcohol solvent, 5%-50% modified chlorinated polypropylene emulsion, 0%-40% auxiliary emulsion, 5%-40% pigment, and 1%-15% additive composition. The invention uses a self-made functional organic acid-modified chlorinated polypropylene water-based emulsion to make ink, and the prepared water-based ink can greatly improve the adhesion and composite performance of the ink on the film. However, the use of too much organic acid in the invention will cause problems such as uneven printing color and blurred imprints in printed products.

[0005] Chinese patent CN105482549A discloses an environmentally friendly sun-proof and wear-resistant water-based ink and its preparation method, including the weight ratio of raw materials: 25%-30% water-based acrylic emulsion, 18%-20% deionized water, 0.2%-0.5% dispersant, 0.2%-0.5% dimethylethanolamine, 0.2%-0.4% wetting agent, 1.5%-2% slow-drying agent, 5%-10% anti-wear agent, 10%-15% anti-ultraviolet sunscreen, 0.2%-0.4% leveling agent and 30%-35% organic pigment. The invention applies a single acrylic emulsion to water-based ink, which has the disadvantages of poor water resistance and poor adhesion, and it is difficult to achieve an ideal printing effect on the metal surface.

[0006] Chinese patent CN103421386A discloses a water-based gold ink for tipping paper, and its raw materials, measured by weight, include the following components: 60-65 parts of water-based color paste; 10-16 parts of water-soluble acrylic resin; 10-15 parts of dispersant; 10-3 parts of water; 0.5-1 parts of additives. Through a special formula and process flow, the problem of water-based gold ink undergoing oxidation reaction in contact with water and turning into copper green is solved, and the printing fastness of the obtained water-based gold ink is also improved. Its printing effect can reach or exceed that of the currently used solvent-based gold ink, and it has great practical application value. However, the connecting material selected in the invention is a water-soluble acrylic resin, which has poor quick-drying performance.

[0007] Therefore, in order to solve the problems of fire safety, reduce oil resource consumption, reduce atmospheric pollution and improve food packaging hygiene requirements, it is of great significance for the ink and plastic film printing industry to actively develop and apply water-based composite high-temperature inks with excellent high-temperature resistance and environmental protection.

[0008] Therefore, a water-based composite high-temperature ink and its preparation process are proposed. Summary of the invention

[0009] The object of the present invention is to provide a water-based composite high-temperature ink and a preparation process thereof, wherein the monomers methyl methacrylate, methacrylic acid and maleic anhydride are mixed, and then a proper amount of initiator is added to obtain a modified acrylic resin; the prepared modified acrylic resin is used as a connecting material, and is mixed with a pigment, deionized water, an alcohol solvent, a chain extender, a pH adjuster, a dispersant, a wetting agent and a defoaming agent to obtain a water-based composite high-temperature ink. Modified acrylic resin is used as a linker to make the water-based composite high-temperature ink have good high-temperature resistance; controlling the grinding temperature and the amount of wetting agent can make the ink have good wetting properties, thereby improving the ink adhesion; the grinding fineness determines the size and dispersibility of the pigment particles. By controlling the grinding fineness, the pigment particles are fine and evenly distributed to form a firm adhesion layer; by changing the type and amount of defoaming agent, the generation and stability of bubbles are inhibited, which helps the ink to spread more evenly on the substrate and improves the drying speed of the water-based composite high-temperature ink; by controlling the ratio of water and alcohol solvents in the solvent and the type of alcohol solvent, the ink can maintain good fluidity during the printing process, thereby reducing uneven phenomena such as stripes and spots during the printing process, so that the ink is printed evenly on the substrate; by controlling the type and amount of chain extenders, chain extenders are used to increase the crosslinking degree and tightness of the molecular chain, thereby more effectively resisting the penetration and erosion of water molecules, so that the water-based composite high-temperature ink has good water resistance.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] On the one hand, the present invention provides a preparation process of a water-based composite high-temperature ink, wherein the water-based composite high-temperature ink is prepared by the following steps:

[0012] Put 20 parts of solvent in a stirring barrel; add 15 parts of pigment to the solvent while stirring, until the pigment is dissolved and dispersed evenly to obtain a pre-dispersed pigment; add 80 parts of a binder to the pre-dispersed pigment while stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; the aqueous color paste solution is ground to obtain a ground color paste with a grinding fineness of 8-20 μm; the grinding temperature is 25-45°C; add an auxiliary agent to the ground color paste and stir to mix evenly to obtain the aqueous composite high-temperature ink.

[0013] The connecting material is a modified acrylic resin;

[0014] The solvent is a mixed solvent of deionized water and an alcohol solvent;

[0015] The mixing ratio of the deionized water to the alcohol solvent is 1-5:1;

[0016] The auxiliary agent includes 1-3 parts of chain extender, 1 part of pH adjuster, 1 part of dispersant, 1-3 parts of wetting agent and 1-3 parts of defoamer;

[0017] Preferably, the alcohol solvent is one of ethanol, butanol and ethylene glycol.

[0018] Preferably, the chain extender is one of glyceryl monostearate, 2,2-dihydroxymethylpropionic acid, and 2,2-dihydroxymethylbutyric acid.

[0019] Chain extenders can react with the functional groups on the linear polymer chain to extend the molecular chain and increase the molecular weight. In water-based inks, chain extenders are often used to improve the water resistance of acrylic resins. The addition of chain extenders increases the cross-linking density of the high-temperature resistant acrylic resin linker, making the particle structure in the high-temperature resistant acrylic resin more compact and less likely to penetrate with water. After the water-based ink dries, the particles are tightly squeezed to form a denser waterproof ink layer. Therefore, the addition of chain extenders can significantly improve the water resistance of water-based inks.

[0020] Preferably, the pH adjuster is aqueous ammonia.

[0021] Preferably, the dispersant is octadecenylamine acetate.

[0022] Preferably, the wetting agent is polyether-modified silane.

[0023] The main function of wetting agent in water-based ink is to reduce the surface tension of ink and improve the wetting performance of ink. It can help ink to better wet the surface of substrate, increase the contact area between ink and substrate, and thus improve the adhesion of ink. In addition, wetting agent can also improve the fluidity of ink, help the ink to spread evenly during the printing process, and further improve the adhesion performance.

[0024] Preferably, the defoaming agent is one of polyether-siloxane copolymer, polysiloxane and higher alcohol.

[0025] Preferably, the preparation method of the modified acrylic resin comprises the following steps:

[0026] Three monomers, maleic anhydride, methyl methacrylate and methacrylic acid, are mixed to obtain a mixture; 0.8 parts of an initiator, azobisisobutyronitrile, is added to the mixture, and the mixture is stirred evenly to obtain component one; isopropanol is added to a reaction bottle and the temperature is raised to 45°C to obtain heated isopropanol; the ratio of the mixture to the isopropanol is 1:1; the component one is added dropwise to the heated isopropanol under heating and stirring, and the addition is completed evenly within 30 minutes; after the monomer and the initiator are fully dissolved and mixed evenly, the temperature is raised to 75-100°C; the reaction is carried out at a constant temperature for 1-3 hours; the reaction is stopped by cooling to 40°C to obtain a light yellow viscous liquid; after the light yellow viscous liquid is cooled to room temperature, it is dissolved in a mixed solution of water and ethanol and centrifuged for multiple times to obtain the modified acrylic resin.

[0027] Preferably, the ratio of the mixture of the maleic anhydride, the methyl methacrylate and the methacrylic acid is 7-11:8:1-5.

[0028] On the other hand, the present invention provides a water-based composite high-temperature ink, the raw materials used in the production of the water-based composite high-temperature ink include pigments, modified acrylic resins, deionized water, alcohol solvents, chain extenders, pH regulators, dispersants, wetting agents and defoaming agents; the water-based composite high-temperature ink is prepared by any of the preparation processes described above; the high temperature resistance of the water-based composite high-temperature ink is 220°C, and the water-based composite high-temperature ink does not fall off or change color at high temperatures; the adhesion fastness of the water-based composite high-temperature ink is 98%; the initial drying of the water-based composite high-temperature ink is 48mm; the viscosity of the water-based composite high-temperature ink is 20s, and the water-based composite high-temperature ink is printed evenly on the substrate; the color difference of the water-based composite high-temperature ink before and after being wet is 0.53.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention prepares a modified acrylic resin by mixing monomers of methyl methacrylate, methacrylic acid and maleic anhydride, and then adding a proper amount of initiator. By changing the ratio of the three monomers, the amount of initiator, the reaction temperature and the reaction time, the prepared modified acrylic resin is used as a connecting material to make the water-based composite high-temperature ink have a high temperature resistance of 220°C, and there is no shedding or discoloration at high temperatures, and the high temperature resistance is significantly improved.

[0031] 2. The present invention controls the grinding temperature and the amount of wetting agent so that the ink has good wetting properties. Good wetting properties help the ink form a uniform ink film on the surface of the substrate, thereby improving adhesion. The grinding fineness determines the size and dispersibility of the pigment particles. The present invention controls the grinding fineness so that the pigment particles are fine and evenly distributed, and can better penetrate into the surface or interior of the substrate to form a strong adhesion layer. The adhesion fastness of the prepared water-based composite high-temperature ink is 98%, showing significantly improved adhesion.

[0032] 3. The present invention inhibits the generation and stabilization of bubbles by changing the type and amount of defoaming agent, which helps the ink to spread more evenly on the substrate. When there is no air bubble interference on the ink surface, the surface area exposed to the air increases, thereby improving the efficiency of volatile drying. The initial dryness of the prepared water-based composite high-temperature ink is 48mm, and the drying speed is significantly improved.

[0033] 4. The present invention can maintain good fluidity of the ink during the printing process by controlling the ratio of water and alcohol solvents in the mixed solvent and the type of alcohol solvent. The improvement of fluidity can reduce uneven phenomena such as stripes and spots in the printing process, so that the ink is evenly distributed on the substrate. The viscosity of the prepared water-based composite high-temperature ink is 20s, and the water-based composite high-temperature ink is printed evenly on the substrate.

[0034] 5. The present invention controls the type and amount of chain extenders and utilizes chain extenders to improve the crosslinking degree and tightness of the molecular chains, thereby more effectively resisting the penetration and erosion of water molecules. The color difference value of the prepared water-based composite high-temperature ink before and after being wetted is 0.53, showing significantly improved water resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a graph showing the drying speed test results of the water-based composite high-temperature ink of Example 35 of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0037] See also Figure 1 The present invention provides a water-based composite high-temperature ink and a preparation process thereof, and the technical scheme is as follows:

[0038] The substance information involved in the present invention is as follows:

[0039] Methyl methacrylate CAS: 80-62-6; methacrylic acid CAS: 79-41-4; maleic anhydride CAS: 108-31-6; azobisisobutyronitrile CAS: 78-67-1; isopropyl alcohol CAS: 67-63-0; glyceryl monostearate CAS: 31566-31-1; 2,2-dihydroxymethylpropionic acid CAS: 4767-03-7; 2,2-dihydroxymethylbutyric acid CAS: 10097-02-6; ammonia CAS: 1336-21-6; polysiloxane CAS: 63148-62-9; alcohol solvents were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; octadeceneamine acetate was purchased from Hunan Changsha Hengchang Chemical Co., Ltd.; polyether modified silane was purchased from Guangzhou Xinguan Chemical Technology Co., Ltd.; polyether-siloxane copolymer was purchased from Jiangsu Yak Technology Co., Ltd.; high carbon alcohol was purchased from Huzhou Shengtao Biotechnology Co., Ltd.

[0040] Example 1

[0041] Preparation of modified acrylic resin:

[0042] The three monomers of maleic anhydride, methyl methacrylate and methacrylic acid are mixed in a ratio of 7:8:5 to obtain a mixture; 0.8 parts of azobisisobutyronitrile as an initiator are added to the mixture, and the mixture is stirred evenly to obtain component one; isopropanol in a ratio of 1:1 to the monomer is added to a reaction bottle, and the temperature is raised to 45°C; the component one is added dropwise under heating and stirring, and the addition is completed evenly over 30 minutes; after the monomer and the initiator are fully dissolved and mixed evenly, the temperature is raised to 75°C; the reaction is carried out at a constant temperature for 1 hour; the reaction is stopped by cooling to 40°C to obtain a light yellow viscous liquid; after the light yellow viscous liquid is cooled to room temperature, it is dissolved in a mixed solution of water and ethanol and centrifuged several times to obtain the modified acrylic resin.

[0043] Preparation of water-based composite high-temperature ink:

[0044] Place 20 parts of a mixed solvent of deionized water and ethanol in a stirring barrel in a ratio of 1:1; add 15 parts of pigment to the solvent while stirring until the pigment is dissolved and dispersed evenly to obtain a pre-dispersed pigment; add 80 parts of the connecting material to the pre-dispersed pigment while stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; grind the aqueous color paste solution to obtain a grinding color paste with a grinding fineness of 8 μm; the grinding temperature is 25°C; add 1 part of the chain extender glyceryl monostearate, 1 part of the pH adjuster ammonia water, 1 part of the dispersant octadeceneamine acetate, 1 part of the wetting agent polyether modified silane, and 1 part of the defoaming agent polyether-siloxane copolymer to the grinding color paste and stir to mix evenly to obtain an aqueous composite high-temperature ink.

[0045] Example 2-13

[0046] With reference to the process conditions of Example 1, the specific differences are listed in Table 1.

[0047] Table 1 Parameter conditions of Examples 2-13

[0048]

[0049]

[0050] Comparative Example 1

[0051] Commercially available water-based ink.

[0052] Example 14 High temperature resistance test

[0053] The high temperature resistance of the ink was tested by thermogravimetric analysis using a TGA55 thermogravimeter.

[0054] Select labels of the same specification of 4 cm × 4 cm, and coat the back thereof with the water-based composite high-temperature ink with a thickness of 3 mm prepared in Examples 1-13 and Comparative Example 1, and then bond the labels to the same carrier, select a polished metal plate as the carrier, and place the metal plate with the labels in an oven at 160°C for 5 h, 10 h, 15 h, 20 h, and 30 h, respectively, to observe the degree of bonding strength and whether there is any peeling or discoloration. The results are shown in Table 2.

[0055] Table 2 High temperature resistance test of Examples 1-13 and Comparative Example 1

[0056]

[0057]

[0058] As shown in Table 2, in Examples 1-4, as the content of maleic anhydride increases, the monomer conversion rate is improved, and the high temperature resistance of the polymerized product is significantly improved; however, in Example 5, when the proportion of maleic anhydride is too large, the proportion of other monomers is too low, which is not conducive to the polymerization reaction to form acrylic resin. At this time, the high temperature resistance is reduced to 171°C, and the phenomenon of shedding and discoloration will occur after being stored at high temperature for 20 hours; in Examples 2, 9, and 10, the reaction temperature is low, resulting in a slow reaction speed or even incomplete reaction, and the molecular weight of the synthetic resin is low, so that the prepared ink has poor high temperature resistance; increasing the temperature is conducive to increasing the monomer conversion rate, but in the synthesis process of acrylic resin, the reaction temperature is inversely proportional to the final molecular weight. If the temperature is too high, it is easy to cause side reactions such as thermal polymerization of acrylic acid, resulting in a decrease in the conversion rate of the resin monomer and a corresponding decrease in the molecular weight of the resin. The low molecular weight acrylic resin leads to a decrease in high temperature resistance. In Examples 5, 6, and 13, the reaction temperature reaches 100°C, the reaction speed is too fast, the reaction is difficult to control, and even explosion occurs, resulting in reduced high temperature resistance of the obtained ink; in Examples 1 and 9, the reaction time is too short, the reaction cannot be completed, and the monomers that are not completely reacted and remain in the resin will have an adverse effect on the high temperature resistance of the resin, and will fall off and discolor after being stored at high temperature for 20 hours; as the reaction time increases, the conversion rate increases, which will cause more chains to transfer to large molecular weight, and the high temperature resistance is also improved accordingly. However, after the molecular weight increases to a certain extent, it no longer increases with the reaction time, and the high temperature resistance of the synthetic resin is no longer improved. In Example 12, the reaction time is extended to 3 hours, and the high temperature resistance of the obtained ink is 216°C, which does not continue to increase. In Example 8, when the three monomers of maleic anhydride, methyl methacrylate, and methacrylic acid were mixed in a ratio of 9:8:3, the reaction time was 2.5h, and the reaction temperature was 82°C, the modified acrylic resin had the best high temperature resistance, and the water-based composite high temperature ink obtained had a high temperature resistance of 220°C, and would not fall off or change color even if stored at high temperature for a long time. The commercially available ink used in Comparative Example 1 had poor high temperature resistance, with a high temperature resistance of only 130°C, and would fall off or change color when stored at high temperature.

[0059] Embodiment 15

[0060] Preparation of modified acrylic resin:

[0061] The three monomers of maleic anhydride, methyl methacrylate and methacrylic acid are mixed in a ratio of 9:8:3 to obtain a mixture; 0.8 parts of azobisisobutyronitrile as an initiator are added to the mixture, and the mixture is stirred evenly to obtain component one; isopropanol in a ratio of 1:1 to the monomer is added to a reaction bottle, and the temperature is raised to 45°C; the component one is added dropwise under heating and stirring, and the addition is completed evenly over 30 minutes; after the monomer and the initiator are fully dissolved and mixed evenly, the temperature is raised to 82°C; the reaction is carried out at a constant temperature for 2.5 hours; the reaction is stopped by cooling to 40°C to obtain a light yellow viscous liquid; after the light yellow viscous liquid is cooled to room temperature, it is dissolved in a mixed solution of water and ethanol and centrifuged several times to obtain the modified acrylic resin.

[0062] Preparation of water-based composite high-temperature ink:

[0063] Place 20 parts of a mixed solvent of deionized water and ethanol in a stirring barrel in a ratio of 1:1; add 15 parts of pigment to the solvent while stirring until the pigment is dissolved and dispersed evenly to obtain a pre-dispersed pigment; add 80 parts of the connecting material to the pre-dispersed pigment while stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; grind the aqueous color paste solution to obtain a grinding color paste with a grinding fineness of 8 μm; the grinding temperature is 25°C; add 1 part of the chain extender glyceryl monostearate, 1 part of the pH adjuster ammonia water, 1 part of the dispersant octadeceneamine acetate, 1.5 parts of the wetting agent polyether modified silane, and 1 part of the defoaming agent polyether-siloxane copolymer to the grinding color paste and stir to mix evenly to obtain an aqueous composite high-temperature ink.

[0064] Examples 16-24

[0065] Referring to the process conditions of Example 15, the specific differences are listed in Table 3.

[0066] Table 3 Parameters and conditions of Examples 16-24

[0067] Example Wetting agent dosage / part Grinding fineness / μm Grinding temperature / ℃ Example 16 2 8 25 Embodiment 17 2.5 8 25 Embodiment 18 3 8 25 Embodiment 19 2 13 25 Embodiment 20 2 16 25 Embodiment 21 2 20 25 Embodiment 22 2 8 30 Embodiment 23 2 8 38 Embodiment 24 2 8 45

[0068] Comparative Example 2

[0069] A water-based composite high-temperature ink was prepared according to the method of Example 15, except that no wetting agent was added.

[0070] Example 25 Adhesion Test

[0071] Prepare the scraping sample with reference to the national standard GB / T13217.1, place the scraping sample at room temperature for 24 hours, use tape to evenly adhere to the surface of the ink layer, and then place it on the adhesive tape roller to roll it back and forth 3 times. After it is firmly adhered, keep the tape at a right angle to the ink layer and quickly tear off the tape in the opposite direction. Use a 2mm wide translucent grid paper to place it on the ink surface torn by the tape, observe the remaining ink layer and the number of grids of the ink layer removed by the tape, and calculate the ink adhesion strength with the formula: Where A is the ink adhesion strength, M is the number of ink layers, and N is the number of ink layers removed; the results are shown in Table 4.

[0072] Table 4 Adhesion test of Examples 8, 15-24 and Comparative Example 1

[0073]

[0074]

[0075] As shown in Table 4, in Example 18, excessive amount of wetting agent will lead to excessively high water content in the ink and insufficient drying of the ink, thereby reducing the adhesion of the ink, and the adhesion fastness is reduced to 90%. The printed matter is prone to deinking, fading and other problems during subsequent processing or use; in Example 8, insufficient amount of wetting agent is used, the surface tension of the ink will be relatively high, and it is difficult to fully wet the surface of the substrate, which will lead to weakened adhesion of the ink on the substrate, the adhesion fastness is 91%, and the printing effect is not ideal. The fineness of the ink directly determines the size of the pigment particles and the degree of dispersion in the binder. Inks with good fineness have uniformly distributed pigment particles and a larger specific surface area, which can provide more opportunities for interaction with the surface of the substrate, thereby better penetrating into the surface or interior of the substrate to form a strong adhesion layer. Inks with good fineness can maintain good fluidity during the printing process, forming a more uniform and smooth ink film, which can better contact the surface of the substrate, reduce the generation of voids and bubbles, and thus improve adhesion. On the contrary, inks with poor fineness are prone to problems such as plate clogging and plate sticking during the printing process, affecting the quality and adhesion of the ink film. In Examples 16, 19-21, as the grinding fineness increases, the adhesion strength gradually decreases. The grinding temperature will affect the solubility and dispersibility of the resin, pigment and other components in the ink. If the grinding temperature is too high, the components may volatilize or deteriorate, which will affect the wetting performance and adhesion of the ink. In Example 24, the grinding temperature is 45°C, and the ink adhesion is reduced to 93%; if the temperature is too low, the viscosity of the ink will increase and the fluidity will deteriorate, which will make it difficult for the ink to be evenly spread on the substrate during the printing process, thereby affecting the adhesion of the ink. In Example 16, when the grinding temperature is 25°C, the ink adhesion is 92%. In Example 22, when 2 parts of wetting agent are added, the grinding fineness is 8μm, and the grinding temperature is controlled at 30°C, the obtained water-based composite high-temperature ink has the best adhesion performance and the adhesion reaches 98%; while in Comparative Example 2, the adhesion of the water-based composite high-temperature ink obtained without adding a wetting agent is only 82%.

[0076] Embodiment 26

[0077] The modified acrylic resin was prepared according to the method of Example 15 above.

[0078] Preparation of water-based composite high-temperature ink:

[0079] Place 20 parts of a mixed solvent of deionized water and ethanol in a stirring barrel in a ratio of 1:1; add 15 parts of pigment to the solvent while stirring until the pigment is dissolved and dispersed evenly to obtain a pre-dispersed pigment; add 80 parts of the connecting material to the pre-dispersed pigment while stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; grind the aqueous color paste solution to obtain a grinding color paste with a grinding fineness of 8 μm; the grinding temperature is 30°C; add 1 part of the chain extender glyceryl monostearate, 1 part of the pH ammonia water, 1 part of the dispersant octadeceneamine acetate, 2 parts of the wetting agent polyether modified silane, and 1.5 parts of the defoaming agent polyether-siloxane copolymer to the grinding color paste, stir and mix evenly to obtain an aqueous composite high-temperature ink.

[0080] Examples 27-34

[0081] Referring to the process conditions of Example 26, the specific differences are listed in Table 5.

[0082] Comparative Example 3

[0083] A water-based composite high-temperature ink was prepared according to the method of Example 26, except that no defoaming agent was added.

[0084] Example 35 Drying speed test

[0085] Refer to the national standard GB / T13217.5, add the ink to be tested to the deepest groove of the 0μm-100μm scraper fineness gauge and fill the groove, use a scraper to quickly scrape it off and start timing, after 30s, use a PET film to cover the groove and press it tightly, immediately peel off the PET film, measure the length without ink from 0μm, measure three times in parallel, and take the arithmetic average; the results are as follows Figure 1 And as shown in Table 5.

[0086] Table 5 Drying speed test of Examples 22, 26-34 and Comparative Example 3

[0087] Example Defoamer Type Defoamer dosage / portion Initial dryness / mm Embodiment 22 Polyether-siloxane copolymer 1 42 Embodiment 26 Polyether-siloxane copolymer 1.5 44 Embodiment 27 Polyether-siloxane copolymer 2 48 Embodiment 28 Polyether-siloxane copolymer 3 43 Embodiment 29 Polysiloxane 1 42 Embodiment 30 Polysiloxane 2 45 Embodiment 31 Polysiloxane 3 42 Embodiment 32 High carbon alcohol 1 41 Embodiment 33 High carbon alcohol 2 45 Embodiment 34 High carbon alcohol 3 41 Comparative Example 3 / / 31

[0088] like Figure 1As shown in the results of Table 5, the initial drying properties of the water-based composite high-temperature inks prepared in Examples 22, 26-34, and Comparative Example 3 are 31-48 mm. The bubbles in the ink will hinder the contact between the ink and the air, thereby delaying the drying process, and the defoaming agent can reduce the tiny bubbles in the ink, making it easier for water or other volatile components to escape from the ink; when there is no interference from bubbles on the surface of the ink, the surface of the ink is smoother and can be spread more evenly on the substrate, and its surface area exposed to the air increases, thereby increasing the speed of volatile drying. Excessive addition of defoaming agent in Examples 28, 31, and 34 causes the ink to be too thin, making it easy for the ink to flow during the printing process and forming an uneven coating, which in turn affects the drying speed and reduces the initial drying property; excessive defoaming agent may also cause defects such as ink stratification, agglomeration, or shrinkage holes, thereby affecting the drying performance of the ink. The polyether-siloxane copolymer defoamer combines the advantages of polyether and siloxane, has good compatibility with the water-based ink system, can effectively reduce the generation of bubbles without affecting the viscosity, fluidity and adhesion of the ink, has excellent defoaming and anti-foaming properties, makes the ink surface smoother, thereby facilitating the contact between the ink and the air and improving the drying speed. In Example 27, 2 parts of polyether-siloxane copolymer were added as a defoamer to the water-based composite high-temperature ink, which increased the drying speed of the water-based composite ink, and its initial dryness reached 48mm; while in Comparative Example 3, no defoamer was added to the water-based composite high-temperature ink, and its initial dryness was only 31mm, and the drying speed was slow.

[0089] Embodiment 36

[0090] The modified acrylic resin was prepared according to the method of Example 15 above.

[0091] Preparation of water-based composite high-temperature ink:

[0092] Place 20 parts of a mixed solvent of deionized water and ethanol in a stirring barrel in a ratio of 3:1; add 15 parts of pigment to the solvent while stirring until the pigment is dissolved and dispersed evenly to obtain a pre-dispersed pigment; add 80 parts of the connecting material to the pre-dispersed pigment while stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; grind the aqueous color paste solution to obtain a grinding color paste with a grinding fineness of 8 μm; the grinding temperature is 30°C; add 1 part of the chain extender glyceryl monostearate, 1 part of the pH adjuster ammonia water, 1 part of the dispersant octadeceneamine acetate, 2 parts of the wetting agent polyether modified silane, and 2 parts of the defoaming agent polyether-siloxane copolymer to the grinding color paste and stir and mix evenly to obtain an aqueous composite high-temperature ink.

[0093] Examples 37-43

[0094] Referring to the process conditions of Example 36, the specific differences are listed in Table 6.

[0095] Comparative Example 4

[0096] A water-based composite high-temperature ink was prepared according to the method of Example 36, except that no alcohol solvent was added.

[0097] Example 44 Viscosity and printing uniformity test

[0098] Use the Japanese Zahn Cup No. 4 cup for testing. Put the water-based composite high-temperature ink into the Zahn Cup No. 4, release your fingers, and use the time (s) from the emulsion flowing out to the line breaking to indicate the viscosity. The longer the flow time, the greater the viscosity. Measure three times and take the average value.

[0099] The water-based composite high-temperature ink was printed on a plastic film using a manual color wheel and dried in an electric heated blast constant temperature drying oven at 80°C for 30 seconds to obtain an ink sample, and the ink uniformity was visually inspected; the results are shown in Table 6.

[0100] Table 6 Viscosity and printing uniformity test of Examples 27, 36-43 and Comparative Example 4

[0101]

[0102]

[0103] Viscosity directly affects the transfer performance of ink and the quality of printed products. Low viscosity can speed up the transfer speed of ink, but before the ink dries, it will produce corresponding expansion, which will lead to an unbalanced overall spreading effect of the ink, resulting in problems such as light color and large dot expansion; high viscosity will slow down the transfer of ink and affect the printing effect, such as dirty and paste versions. Ethanol is often used as a diluent in water-based inks, which can quickly and evenly disperse the ink, improve printing uniformity, and reduce the consumption of ink and reduce costs; in addition, ethanol has a fast evaporation rate, which can prevent pollution and blurring in printing; butanol has a relatively slow evaporation rate, which will cause the ink to dry too slowly, causing the printed product to stick and blur; ethylene glycol has a certain hygroscopicity, which is easy to absorb moisture in the air, thereby causing the viscosity of the ink to change, and then affecting the printing uniformity of the ink. If the water content in the ink is too high, it may also cause the ink to dry slowly. In Examples 38-43, when butanol or ethylene glycol is used as an alcohol solvent, the printing uniformity of the obtained ink is not as good as that of the ink obtained when ethanol is used as an alcohol solvent. The viscosity of the ink can be changed by adjusting the ratio of ethanol to water. When the viscosity of the ink is too high, increasing the proportion of ethanol appropriately can reduce the viscosity and improve the fluidity and transfer performance of the ink. As shown in Table 6, in Example 27, the excessively high proportion of ethanol causes the ink to be too diluted, affecting the uniformity of the ink printing, and the viscosity of the obtained ink is 15s. In Example 36, deionized water and ethanol are selected as mixed solvents. When the mixing ratio is 3:1, the viscosity of the ink is moderately 20s, and it is printed evenly on the substrate; in Comparative Example 4, only deionized water is used as the solvent, and the viscosity is too high, resulting in uneven printing.

[0104] Embodiment 45

[0105] The modified acrylic resin was prepared according to the method of Example 15 above.

[0106] Preparation of water-based composite high-temperature ink:

[0107] Place 20 parts of a mixed solvent of deionized water and ethanol in a stirring barrel in a ratio of 3:1; add 15 parts of pigment to the solvent while stirring until the pigment is dissolved and dispersed evenly to obtain a pre-dispersed pigment; add 80 parts of the connecting material to the pre-dispersed pigment while stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; grind the aqueous color paste solution to obtain a grinding color paste with a grinding fineness of 8 μm; the grinding temperature is 30°C; add 2 parts of the chain extender glyceryl monostearate, 1 part of the pH adjuster ammonia water, 1 part of the dispersant octadeceneamine acetate, 2 parts of the wetting agent polyether modified silane, and 2 parts of the defoaming agent polyether-siloxane copolymer to the grinding color paste and stir to mix evenly to obtain an aqueous composite high-temperature ink.

[0108] Examples 46-52

[0109] Referring to the process conditions of Example 45, the specific differences are listed in Table 7.

[0110] Comparative Example 5

[0111] A water-based composite high-temperature ink was prepared according to the method of Example 46, except that no chain extender was added.

[0112] Example 54 Water resistance test

[0113] Use a gravure proofing machine to make proofs on different substrates. After they are dried naturally, use an X-rite528 spectrophotometer to measure and record the Lab value. Use a cotton swab to take a small amount of water and evenly apply it on the substrate. After a period of time, use a paper towel to absorb excess water. After drying, measure the Lab value again and calculate the Lab color difference. The color difference calculation formula is: Wherein L is the lightness of the tested product, a is the red / green value of the product, and b is the yellow / blue value of the product; the results are shown in Table 7.

[0114] Table 7 Water resistance test of Examples 36, 45-52 and Comparative Example 5

[0115] Example Chain Extender Chain extender quantity / part Color difference value Embodiment 36 Glyceryl Monostearate 1 1.51 Embodiment 45 Glyceryl Monostearate 2 1.23 Embodiment 46 Glyceryl Monostearate 3 1.30 Embodiment 47 2,2-Dihydroxymethylpropionic acid 1 1.12 Embodiment 48 2,2-Dihydroxymethylpropionic acid 2 1.06 Embodiment 49 2,2-Dihydroxymethylpropionic acid 3 1.14 Embodiment 50 2,2-Dihydroxymethylbutyric acid 1 0.79 Embodiment 51 2,2-Dihydroxymethylbutyric acid 2 0.53 Embodiment 52 2,2-Dihydroxymethylbutyric acid 3 0.88 Comparative Example 5 / / 3.02

[0116] As shown in Table 7, in Examples 36, 47, and 50, when the amount of chain extender is insufficient, the cross-linking reaction in the ink is insufficient, resulting in the inability to effectively improve the water resistance of the ink, and the color difference before and after water exposure is large; in Examples 46, 49, and 52, excessive amount of chain extender will lead to excessive cross-linking reaction in the ink, forming an overly dense network structure, which will reduce the flexibility and adhesion of the ink, and thus reduce the water resistance of the ink; 2,2-dihydroxymethylbutyric acid has better solubility, and the water-based composite high-temperature ink prepared by adding 2,2-dihydroxymethylbutyric acid has better water resistance. In Example 52, 2 parts of 2,2-dihydroxymethylbutyric acid are added to the water-based composite high-temperature ink as a chain extender. At this time, the color difference value of the water-based composite high-temperature ink before and after water exposure is only 0.53, and the water resistance is the best; while in Comparative Example 5, the water resistance of the water-based composite high-temperature ink prepared without adding a chain extender is significantly reduced, and the color difference value before and after water exposure reaches 3.02.

[0117] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a water-based composite high-temperature ink, characterized in that: The water-based composite high-temperature ink is prepared by the following steps: Put 20 parts of solvent in a stirring barrel; add 15 parts of pigment into the solvent under stirring until the pigment is dissolved and dispersed uniformly to obtain pre-dispersed pigment; add 80 parts of connecting material into the pre-dispersed pigment under stirring to obtain an aqueous color paste solution; the stirring speed is 800 rpm; grind the aqueous color paste solution to obtain a grinding color paste with a grinding fineness of 8-20 μm; the grinding temperature is 25-45°C; add an auxiliary agent into the grinding color paste and stir and mix uniformly to obtain the aqueous composite high-temperature ink; The connecting material is a modified acrylic resin; The solvent is a mixed solvent of deionized water and an alcohol solvent; The mixing ratio of the deionized water to the alcohol solvent is 1-5:1; The auxiliary agent includes 1-3 parts of chain extender, 1 part of pH adjuster, 1 part of dispersant, 1-3 parts of wetting agent and 1-3 parts of defoamer.

2. The process for preparing a water-based composite high-temperature ink according to claim 1, characterized in that: The alcohol solvent is one of ethanol, butanol and ethylene glycol.

3. The process for preparing a water-based composite high-temperature ink according to claim 2, characterized in that: The chain extender is one of glyceryl monostearate, 2,2-dihydroxymethyl propionic acid and 2,2-dihydroxymethyl butyric acid.

4. The process for preparing a water-based composite high-temperature ink according to claim 1, characterized in that: The pH regulator is aqueous ammonia.

5. The process for preparing a water-based composite high-temperature ink according to claim 1, characterized in that: The dispersant is octadecenylamine acetate.

6. The process for preparing a water-based composite high-temperature ink according to claim 1, characterized in that: The wetting agent is polyether-modified silane.

7. The process for preparing a water-based composite high-temperature ink according to claim 1, characterized in that: The defoamer is one of polyether-siloxane copolymer, polysiloxane and higher alcohol.

8. The process for preparing a water-based composite high-temperature ink according to claim 1, characterized in that: The preparation method of the modified acrylic resin comprises the following steps: Three monomers, maleic anhydride, methyl methacrylate and methacrylic acid, are mixed to obtain a mixture; 0.8 parts of an initiator, azobisisobutyronitrile, is added to the mixture, and the mixture is stirred evenly to obtain component one; isopropanol is added to a reaction bottle and the temperature is raised to 45°C to obtain heated isopropanol; the ratio of the mixture to the isopropanol is 1:1; the component one is added dropwise to the heated isopropanol under heating and stirring, and the addition is completed evenly within 30 minutes; after the monomer and the initiator are fully dissolved and mixed evenly, the temperature is raised to 75-100°C; the reaction is carried out at a constant temperature for 1-3 hours; the reaction is stopped by cooling to 40°C to obtain a light yellow viscous liquid; after the light yellow viscous liquid is cooled to room temperature, it is dissolved in a mixed solution of water and ethanol and centrifuged for multiple times to obtain the modified acrylic resin.

9. The process for preparing a water-based composite high-temperature ink according to claim 8, characterized in that: The mixing ratio of the maleic anhydride, the methyl methacrylate and the methacrylic acid is 7-11:8:1-5.

10. A water-based composite high-temperature ink, characterized in that: The raw materials for producing the water-based composite high-temperature ink include pigments, modified acrylic resins, deionized water, alcohol solvents, chain extenders, pH regulators, dispersants, wetting agents, and defoamers; the water-based composite high-temperature ink is prepared by the preparation process described in any one of claims 1 to 9; the water-based composite high-temperature ink has a high temperature resistance of 220°C, and the water-based composite high-temperature ink does not fall off or change color at high temperatures; the adhesion fastness of the water-based composite high-temperature ink is 98%; The initial dryness of the water-based composite high-temperature ink is 48mm; the viscosity of the water-based composite high-temperature ink is 20s, and the water-based composite high-temperature ink is printed evenly on the substrate; The color difference of the water-based composite high-temperature ink before and after being wetted with water is 0.53.

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