Environment-friendly water-based ink for gravure of plastic film and preparation method thereof

Abstract

The invention belongs to the technical field of water-based ink, and particularly relates to environment-friendly water-based ink for plastic film gravure and a preparation method of the environment-friendly water-based ink. The water-based ink is prepared from, by mass, 30-50 parts of water-based acrylic resin liquid, 10-15 parts of water-based polyurethane resin, 20-30 parts of deionized water, 1-2 parts of dispersing agent, 10-14 parts of pigment, 2-4 parts of modified calcium carbonate, 0.5-1 part of polyvinyl alcohol wax, 4-10 parts of ethyl alcohol and 1-2 parts of anti-settling agent, silica modified calcium carbonate is adopted as the modified calcium carbonate, and the preparation method of the water-based ink is provided. The problems of poor dispersibility and poor stability of calcium carbonate are solved, calcium carbonate is wrapped in a silica modification mode, surface inertia of calcium carbonate is converted into silicon hydroxyl activity in a silica system, and the dispersibility and stability of calcium carbonate are effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based inks, and in particular relates to an environmentally friendly water-based ink for gravure printing of plastic films and a preparation method thereof. Background Art

[0002] With the development of culture, science and technology, and economy, the printing industry has developed rapidly. As an indispensable raw material for the printing industry, the world's ink production has reached 4.2 million tons. The environmental pollution caused by ink is serious every year, which directly endangers human health. With the continuous improvement of people's environmental awareness, green and environmental protection are becoming more and more important in the field of ink. Therefore, the development of low-pollution and pollution-free green ink has become an inevitable requirement for the green development of the printing field. Therefore, the research and development of water-based inks has become more and more important. In water-based inks, the dispersibility of filler-based water-based inks will decrease significantly over time, and even sedimentation will occur directly. In addition, the filler will appear powdered during the long-term static state of water-based ink printing, resulting in a decrease in printing quality, especially calcium carbonate fillers. In response to this problem, the market needs an excellent filler-based water-based ink. Summary of the invention

[0003] In view of the problems in the prior art, the present invention provides an environmentally friendly water-based ink for gravure printing of plastic films, which solves the problems of poor dispersibility and poor stability of calcium carbonate. The calcium carbonate is wrapped by silicon-oxygen modification, and the surface inertness of the calcium carbonate is converted into the silanol activity in the silicon-oxygen system, which effectively improves the dispersibility and stability of the calcium carbonate.

[0004] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0005] An environmentally friendly water-based ink for gravure printing of plastic films, the mass ratio of which is:

[0006] 30-50 parts of water-based acrylic resin liquid, 10-15 parts of water-based polyurethane resin, 20-30 parts of deionized water, 1-2 parts of dispersant, 10-14 parts of pigment, 2-4 parts of modified calcium carbonate, 0.5-1 parts of polyvinyl alcohol wax, 4-10 parts of ethanol, and 1-2 parts of anti-settling agent.

[0007] The waterborne acrylic resin has a solid content of 30-35 wt %, and a viscosity of 700-900 MPa·s at 25° C.

[0008] The waterborne polyurethane resin adopts model PU7307 waterborne polyurethane, which is purchased from Shanghai Belt New Material Technology Co., Ltd.

[0009] The dispersant used is low molecular weight polyethylene glycol, and the molecular weight of the low molecular weight polyethylene glycol is 400 - 600. The low molecular weight polyethylene glycol has good permeability and lubricity, can quickly penetrate into surface cracks, and can also be quickly dispersed into the resin solution, thus achieving the effect of homogeneous dispersion. Aiming at the granularity and physical insolubility of the modified calcium carbonate itself, polyethylene glycol can effectively improve the stability and dispersion of the modified calcium carbonate, prevent its deposition in the water-based ink, and ensure its homogeneous dispersion in the whole ink; at the same time, the surface of the modified calcium carbonate belongs to silicon-oxygen modified calcium carbonate, and is covered with silicon hydroxyl groups. Combining with the high reaction activity of the low molecular weight polyvinyl alcohol, a chemical reaction is achieved; secondly, the low molecular weight polyethylene glycol can form good solubility in ethanol and achieve the effect of preliminary dispersion. Combining with the homogeneous dispersion of the modified calcium carbonate, the initial preferential aggregation effect is achieved, realizing the dispersion and stability of the modified calcium carbonate. Finally, the low molecular weight polyethylene glycol has good fluidity.

[0010] The pigment used is a water-based pigment, and the water-based pigments are red, yellow, blue, black, and white water-based pigments. The particle size of the water-based pigment is nanoscale. In the silicon-oxygen modified layer of the modified calcium carbonate, there are not only pore structures after the polycondensation reaction of silicon hydroxyl groups, but also pore structures of the dispersant. That is, the silicon-oxygen modified layer has a porous structure and also has the activity of silicon hydroxyl groups. When the water-based pigment is mixed with the modified calcium carbonate, the water-based pigment will directly penetrate and adhere to the surface of the modified calcium carbonate, forming good adhesion. Combining with the transparency of the silicon-oxygen material itself, the influence of the color of the calcium carbonate itself is solved.

[0011] The modified calcium carbonate uses a silicon-oxygen modified calcium carbonate material. The surface of calcium carbonate is inert, resulting in poor surface connectivity. In the storage of water-based ink, the resin and dispersant in the ink can form a homogeneous dispersion initially, ensuring the formation of a stable structure of calcium carbonate in the water-based ink. However, as time goes by, calcium carbonate will initially settle due to its own gravity, forming filler deposition. In ink printing, the inertness of the calcium carbonate surface ensures the formation of a gap between it and the resin, and this gap will gradually expand during the aging of the resin. After a long time of storage, calcium carbonate will fall off, that is, the water-based ink will show a phenomenon of powder dropping. To solve the above problems, the silicon-oxygen modified calcium carbonate material uses a silicon-oxygen structure as a framework to completely wrap calcium carbonate, forming a porous outer shell on the surface. This porous outer shell can not only form physical clamping and curing in an interpenetrating manner using its own porous structure, but also the silanol groups on the porous outer shell can form stable connectivity, achieving the effect of chemical connection. Finally, through physical clamping and chemical connection, the modified calcium carbonate can always maintain excellent stability and dispersibility after ink printing. The preparation method of the silicon-oxygen modified calcium carbonate includes the following steps: a1, adding light calcium carbonate into an ethanol aqueous solution and performing low-temperature ultrasonic treatment, then filtering and drying after wet grinding to obtain fine light calcium carbonate powder; the volume of ethanol in the ethanol aqueous solution is 40-50%, the mass ratio of light calcium carbonate to the ethanol aqueous solution is 3-5:1, the temperature of the low-temperature ultrasonic treatment is 5-10°C, the ultrasonic frequency is 70-90 kHz, the pressure of the wet grinding is 0.4-0.6 MPa, the temperature is 20-50°C, and the drying temperature after filtration is 100-200 g / L. This step utilizes the surface porous characteristics and insolubility of light calcium carbonate to form good dispersibility, and through wet grinding, the light calcium carbonate is made into fine powder. Finally, surface impurities are removed by ultrasonic washing and filtration to obtain relatively clean fine light calcium carbonate powder; a2, adding polyvinyl alcohol into water and stirring evenly to form a dilute solution, then adding the fine light calcium carbonate powder and performing ultrasonic treatment for 2-4 h, filtering and drying to obtain coated calcium carbonate powder. The concentration of polyvinyl alcohol in water is 10-30 g / L, the stirring speed for even stirring is 500-700 r / min, the concentration of the fine light calcium carbonate powder in the dilute solution is 100-200 g / L, the ultrasonic frequency of the ultrasonic treatment is 60-80 kHz, and the temperature is 30-40°C; the drying temperature is 120-125°C. This step utilizes the solubility characteristics of polyvinyl alcohol in water to form a dilute solution. When adding the fine light calcium carbonate powder and performing ultrasonic treatment, the ultrasonic waves remove the bubbles on the surface of the fine light calcium carbonate powder, ensuring the deposition of polyvinyl alcohol on the surface of the calcium carbonate powder, and obtaining a polyvinyl alcohol coating after drying;a3, sintering the coated calcium carbonate fine powder at a constant temperature for 20-30 minutes, then adding it to a silane solution and soaking it at low temperature for 20-30 minutes, filtering and drying it to obtain a secondary coated fine powder, wherein the constant temperature sintering temperature is 250-255°C, and the constant temperature sintering is carried out under a nitrogen atmosphere, the silane solution contains bis(3-chloropropyl)dichlorosilane, further, the silane solution is a bis(3-chloropropyl)dichlorosilane-ether solution, the concentration of bis(3-chloropropyl)dichlorosilane in the silane solution is 30-60g / L, the concentration of ethyl cellulose is 10-20g / L, the low temperature soaking temperature is 5-10°C, and the drying temperature is 35-40°C; in this step, polyvinyl alcohol is in-situ condensed into a polymer containing conjugated double bonds by constant temperature sintering; soaking it in an ether solution containing ethyl cellulose and bis(3-chloropropyl)dichlorosilane, and during the low temperature soaking process, the ether solution is deposited on the coated A liquid film is formed on the film calcium carbonate fine powder, and after drying, a composite surface film of bis(3-chloropropyl)dichlorosilane and ethyl cellulose is obtained; a4, the secondary coating fine powder is sealed and allowed to stand for 2-4 hours, sintered for 1-2 hours, immersed in ethanol, filtered and dried to obtain silicon-oxygen modified calcium carbonate, the atmosphere of the sealed standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10-12:1, the temperature is 5-10°C, the sintering temperature is 100-120°C, and the drying temperature is 100-110°C. In this step, during the sealed standing, bis(3-chloropropyl)dichlorosilane is in-situ hydrolyzed to form bis(3-hydroxypropyl)dihydroxysilane, and in-situ polycondensation is formed during sintering to obtain a surface silicon oxide layer. At the same time, ethyl cellulose itself has good stability and plays a barrier effect, thereby ensuring the porosity and porous interlaced structural characteristics of the silicon oxide layer and exposing the internal polymer containing conjugated double bonds. The silicon-oxygen modified calcium carbonate prepared by this process seals the calcium carbonate to the inner core, and uses a polymer containing conjugated double bonds to wrap it, and cooperates with the silicon-oxygen porous structure to achieve the dual combination of the active exposure of conjugated double bonds and silicon hydroxyl groups and the porous structure. The conjugated double bond polymer not only has good antistatic properties, forms static transfer and adsorption, and reduces the impact of static electricity, but also its own activity can react with other materials to improve the overall connection stability of calcium titanate. ;

[0012] The anti-settling agent is fumed silica, and the particle size of the fumed silica is 200-400nm; the anti-settling agent has a small particle size, a large specific surface area, and a silanol group on the surface, and can form a homogeneous structure with modified calcium carbonate, thereby improving the wear resistance of the ink; the hydrogen bond formed by the modified calcium carbonate and the fumed silica greatly improves the sedimentation performance of the modified calcium carbonate, and has excellent dispersibility.

[0013] The method for preparing the environmentally friendly water-based ink for gravure printing of plastic films comprises the following steps:

[0014] Step 1: Add a dispersant to ethanol and stir evenly. Then, add modified calcium carbonate and an anti-settling agent in sequence. After constant-temperature stirring, a dispersed filler is obtained. The stirring speed for even stirring is 300 - 500 r / min, the temperature for constant-temperature stirring is 30 - 40 °C, and the stirring speed is 100 - 200 r / min.

[0015] Step 2: Add an aqueous acrylic resin solution and an aqueous polyurethane resin to a reaction kettle for constant-temperature stirring to obtain a mixed material. The temperature for constant-temperature stirring is 120 - 150 °C, and the stirring speed is 400 - 600 r / min.

[0016] Step 3: Add distilled water to the dispersed filler, and then add a pigment, polyvinyl alcohol wax, and the mixed material in sequence for rapid stirring to obtain an aqueous ink. The stirring speed for rapid stirring is 1000 - 2000 r / min.

[0017] As can be seen from the above description, the present invention has the following advantages:

[0018] 1. The present invention solves the problems of poor dispersibility and stability of calcium carbonate. By using the silicon-oxygen modification method to wrap calcium carbonate, the surface inertness of calcium carbonate is transformed into the activity of silanol groups in the silicon-oxygen system, effectively improving the dispersibility and stability of calcium carbonate.

[0019] 2. The present invention uses fumed silica as an anti-settling agent. It not only forms good dispersibility in the ink and improves the abrasion resistance of the ink, but also the silanol groups on the surface of fumed silica form hydrogen bond interactions with the silanol groups of the silicon-oxygen porous layer, effectively improving the sedimentation performance of the modified calcium carbonate.

[0020] 3. The present invention uses low-molecular-weight polyethylene glycol as a dispersant. By utilizing the permeability and dispersibility of its low-molecular system, it effectively improves the dispersion effect of the modified calcium carbonate. At the same time, its good solubility and lubricity improve the dispersibility and adhesion of the aqueous ink, thereby achieving the practicality of the aqueous ink. Specific Embodiments

[0021] The present invention will be described in detail in combination with embodiments, but no limitation is made to the claims of the present invention.

[0022] Example 1

[0023] An aqueous ink for intaglio printing of an environmentally friendly plastic film has the following mass ratio:

[0024] 30 parts of an aqueous acrylic resin solution, 10 parts of an aqueous polyurethane resin, 20 parts of deionized water, 1 part of a dispersant, 10 parts of a pigment, 2 parts of modified calcium carbonate, 0.5 part of polyvinyl alcohol wax, 4 parts of ethanol, and 1 part of an anti-settling agent.

[0025] The solid content of the waterborne acrylic resin is 30-35 wt%, and the viscosity is 700-900 MPa·s at 25°C.

[0026] The waterborne polyurethane resin used is waterborne polyurethane of model PU7307, specifically purchased from Shanghai Belt New Material Technology Co., Ltd.

[0027] The dispersant used is low molecular weight polyethylene glycol, and the molecular weight of the low molecular weight polyethylene glycol is 400-600.

[0028] The pigment used is a waterborne pigment, and the waterborne pigments are red, yellow, blue, black, and white waterborne pigments. The particle size of the waterborne pigment is nanoscale.

[0029] The modified calcium carbonate used is a silicon-oxygen modified calcium carbonate material, and the preparation method of the silicon-oxygen modified calcium carbonate includes the following steps: a1. Add light calcium carbonate to an ethanol aqueous solution and perform low-temperature ultrasonic treatment. After wet grinding, filter and dry to obtain fine light calcium carbonate powder. The volume of ethanol in the ethanol aqueous solution is 40%, the mass ratio of light calcium carbonate to the ethanol aqueous solution is 3:1, the temperature of the low-temperature ultrasonic treatment is 5°C, the ultrasonic frequency is 70 kHz, the pressure of the wet grinding is 0.4 MPa, the temperature is 20°C, and the drying temperature after filtration is 100 g / L; a2. Add polyvinyl alcohol to water and stir evenly to form a dilute solution. Then add the fine light calcium carbonate powder and perform ultrasonic treatment for 2 h. After filtration, dry to obtain coated calcium carbonate fine powder. The concentration of polyvinyl alcohol in water is 10 g / L, the stirring speed for even stirring is 500 r / min, the concentration of the fine light calcium carbonate powder in the dilute solution is 100 g / L, the ultrasonic frequency of the ultrasonic treatment is 60 kHz, and the temperature is 30°C; the drying temperature is 120°C; a3. Keep the coated calcium carbonate fine powder at a constant temperature and sinter for 20 min, then add it to a silane solution and soak at low temperature for 20 min. After filtration, dry to obtain secondary coated fine powder. The temperature of the constant temperature sintering is 250°C, and the constant temperature sintering is carried out in a nitrogen atmosphere. The silane solution contains bis(3-chloropropyl) dichlorosilane, and the silane solution is a bis(3-chloropropyl) dichlorosilane-ether solution. The concentration of bis(3-chloropropyl) dichlorosilane in the silane solution is 30 g / L, the concentration of ethyl cellulose is 10 g / L, the temperature of the low-temperature soaking is 5°C, and the drying temperature is 35°C; a4. Keep the secondary coated fine powder sealed and static for 2 h, sinter for 1 h, then soak it in ethanol. After filtration, dry to obtain silicon-oxygen modified calcium carbonate. The atmosphere of the sealed static is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, the temperature is 5°C, the sintering temperature is 100°C, and the drying temperature is 100°C.

[0030] The anti-settling agent used is fumed silica, and the particle size of the fumed silica is 200-400 nm.

[0031] The preparation method of the water-based ink for intaglio printing of the environment-friendly plastic film comprises the following steps:

[0032] Step 1: Add a dispersant to ethanol and stir evenly, then sequentially add modified calcium carbonate and an anti-settling agent, and obtain a dispersed filler through constant-temperature stirring; the stirring speed for the even stirring is 300 r / min, the temperature for the constant-temperature stirring is 30 °C, and the stirring speed is 100 r / min;

[0033] Step 2: Add the water-based acrylic resin liquid and the water-based polyurethane resin to a reaction kettle for constant-temperature stirring to obtain a mixed material, the temperature for the constant-temperature stirring is 120 °C, and the stirring speed is 400 r / min;

[0034] Step 3: Add distilled water to the dispersed filler, sequentially add a pigment, polyvinyl alcohol wax and the mixed material, and stir rapidly to obtain the water-based ink, and the stirring speed for the rapid stirring is 1000 r / min.

[0035] Example 2

[0036] A water-based ink for intaglio printing of an environment-friendly plastic film, and its mass ratio is as follows:

[0037] 50 parts of water-based acrylic resin liquid, 15 parts of water-based polyurethane resin, 30 parts of deionized water, 2 parts of dispersant, 14 parts of pigment, 4 parts of modified calcium carbonate, 1 part of polyvinyl alcohol wax, 10 parts of ethanol, 2 parts of anti-settling agent.

[0038] The solid content of the water-based acrylic resin is 30-35 wt%, and the viscosity is 700-900 MPa·s at 25 °C.

[0039] The water-based polyurethane resin adopts the water-based polyurethane of model PU7307, and is specifically purchased from Shanghai Belt New Material Technology Co., Ltd.

[0040] The dispersant adopts low-molecular-weight polyethylene glycol, and the molecular weight of the low-molecular-weight polyethylene glycol is 400-600.

[0041] The pigment adopts water-based pigments, and the water-based pigments are red, yellow, blue, black and white water-based pigments, and the particle size of the water-based pigments is nanoscale.

[0042] The modified calcium carbonate uses a silica-oxygen modified calcium carbonate material, and the preparation method of the silica-oxygen modified calcium carbonate includes the following steps: a1. Add light calcium carbonate to an ethanol aqueous solution and perform low-temperature ultrasonic treatment. After wet grinding, filter and dry to obtain fine light calcium carbonate powder. The volume of ethanol in the ethanol aqueous solution is 50%, the mass ratio of light calcium carbonate to the ethanol aqueous solution is 5:1, the temperature of the low-temperature ultrasonic treatment is 10°C, the ultrasonic frequency is 90 kHz, the pressure of the wet grinding is 0.6 MPa, the temperature is 50°C, and the drying temperature after filtration is 200 g / L; a2. Add polyvinyl alcohol to water and stir evenly to form a dilute solution. Then add the fine light calcium carbonate powder and perform ultrasonic treatment for 4 h. After filtration and drying, obtain coated calcium carbonate fine powder. The concentration of polyvinyl alcohol in water is 30 g / L, the stirring speed for uniform stirring is 700 r / min, the concentration of the fine light calcium carbonate powder in the dilute solution is 200 g / L, the ultrasonic frequency of the ultrasonic treatment is 80 kHz, and the temperature is 40°C; the drying temperature is 125°C; a3. Keep the coated calcium carbonate fine powder at a constant temperature and sinter for 30 min, then add it to a silane solution and soak at low temperature for 30 min. After filtration and drying, obtain secondary-coated fine powder. The temperature of the constant-temperature sintering is 255°C, and the constant-temperature sintering is carried out in a nitrogen atmosphere. The silane solution contains bis(3-chloropropyl)dichlorosilane, and the silane solution is a bis(3-chloropropyl)dichlorosilane-ether solution. The concentration of bis(3-chloropropyl)dichlorosilane in the silane solution is 60 g / L, the concentration of ethyl cellulose is 20 g / L, the temperature of the low-temperature soaking is 10°C, and the drying temperature is 40°C; a4. Keep the secondary-coated fine powder sealed and static for 4 h. After sintering for 2 h, soak it in ethanol. After filtration and drying, obtain silica-oxygen modified calcium carbonate. The atmosphere of the sealed static state is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 12:1, the temperature is 10°C, the sintering temperature is 120°C, and the drying temperature is 110°C.

[0043] The anti-settling agent uses fumed silica, and the particle size of the fumed silica is 200 - 400 nm.

[0044] The preparation method of the water-based ink for intaglio printing of the environment-friendly plastic film includes the following steps:

[0045] Step 1. Add a dispersant to ethanol and stir evenly. Then add the modified calcium carbonate and the anti-settling agent in sequence, and obtain dispersed filler through constant-temperature stirring. The stirring speed for uniform stirring is 500 r / min, the temperature of the constant-temperature stirring is 40°C, and the stirring speed is 200 r / min;

[0046] Step 2. Add the water-based acrylic resin liquid and the water-based polyurethane resin to a reaction kettle and perform constant-temperature stirring to obtain a mixed material. The temperature of the constant-temperature stirring is 150°C, and the stirring speed is 600 r / min;

[0047] Step 3: Add distilled water to the dispersed filler, and then sequentially add pigments, polyvinyl alcohol wax, and the mixed materials and stir rapidly to obtain water-based ink. The stirring speed of the rapid stirring is 2000 r / min.

[0048] Example 3

[0049] A water-based ink for intaglio printing of environmentally friendly plastic films, with the following mass ratio:

[0050] 40 parts of water-based acrylic resin solution, 13 parts of water-based polyurethane resin, 25 parts of deionized water, 2 parts of dispersant, 12 parts of pigments, 3 parts of modified calcium carbonate, 0.8 part of polyvinyl alcohol wax, 8 parts of ethanol, and 2 parts of anti-settling agent.

[0051] The solid content of the water-based acrylic resin is 30 - 35 wt%, and the viscosity is 700 - 900 MPa·s at 25°C.

[0052] The water-based polyurethane resin used is water-based polyurethane of model PU7307, specifically purchased from Shanghai Belt New Material Technology Co., Ltd.

[0053] The dispersant used is low molecular weight polyethylene glycol, and the molecular weight of the low molecular weight polyethylene glycol is 400 - 600.

[0054] The pigments used are water-based pigments, namely red, yellow, blue, black, and white water-based pigments, and the particle size of the water-based pigments is nanoscale.

[0055] The modified calcium carbonate uses a silica-modified calcium carbonate material, and the preparation method of the silica-modified calcium carbonate includes the following steps: a1. Add light calcium carbonate to an ethanol aqueous solution and perform low-temperature ultrasonic treatment. After wet grinding, filter and dry to obtain fine light calcium carbonate powder. The volume of ethanol in the ethanol aqueous solution is 45%, the mass ratio of light calcium carbonate to the ethanol aqueous solution is 4:1, the temperature of the low-temperature ultrasonic treatment is 8°C, the ultrasonic frequency is 80 kHz, the pressure of the wet grinding is 0.5 MPa, the temperature is 40°C, and the drying temperature after filtration is 150 g / L; a2. Add polyvinyl alcohol to water and stir evenly to form a dilute solution. Then add the fine light calcium carbonate powder and perform ultrasonic treatment for 3 h. After filtration and drying, obtain coated calcium carbonate fine powder. The concentration of polyvinyl alcohol in water is 20 g / L, the stirring speed for uniform stirring is 600 r / min, the concentration of the fine light calcium carbonate powder in the dilute solution is 150 g / L, the ultrasonic frequency of the ultrasonic treatment is 70 kHz, and the temperature is 35°C; the drying temperature is 125°C; a3. Keep the coated calcium carbonate fine powder at a constant temperature and sinter for 25 min, then add it to a silane solution and soak at low temperature for 25 min. After filtration and drying, obtain secondary-coated fine powder. The temperature of the constant-temperature sintering is 252°C, and the constant-temperature sintering is carried out in a nitrogen atmosphere. The silane solution contains bis(3-chloropropyl) dichlorosilane, and the silane solution is a bis(3-chloropropyl) dichlorosilane-ether solution. The concentration of bis(3-chloropropyl) dichlorosilane in the silane solution is 50 g / L, the concentration of ethyl cellulose is 15 g / L, the temperature of the low-temperature soaking is 8°C, and the drying temperature is 38°C; a4. Keep the secondary-coated fine powder sealed and static for 3 h, sinter for 2 h, then soak in ethanol. After filtration and drying, obtain silica-modified calcium carbonate. The atmosphere of the sealed static state is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 11:1, the temperature is 8°C, the sintering temperature is 110°C, and the drying temperature is 105°C.

[0056] The anti-settling agent uses fumed silica, and the particle size of the fumed silica is 200 - 400 nm.

[0057] The preparation method of the water-based ink for intaglio printing of the environmentally friendly plastic film includes the following steps:

[0058] Step 1. Add a dispersant to ethanol and stir evenly, then sequentially add the modified calcium carbonate and the anti-settling agent, and obtain dispersed filler through constant-temperature stirring. The stirring speed for uniform stirring is 400 r / min, the temperature of the constant-temperature stirring is 35°C, and the stirring speed is 150 r / min;

[0059] Step 2. Add the water-based acrylic resin liquid and the water-based polyurethane resin to a reaction kettle and perform constant-temperature stirring to obtain a mixed material. The temperature of the constant-temperature stirring is 140°C, and the stirring speed is 500 r / min;

[0060] Step 3: Add distilled water to the dispersed filler, then sequentially add pigment, polyvinyl alcohol wax, and the mixed material, and stir rapidly to obtain water-based ink. The stirring speed of the rapid stirring is 1500 r / min.

[0061] Comparative Example 1

[0062] A water-based ink for gravure printing of environmentally friendly plastic films, with the following mass ratio:

[0063] 40 parts of water-based acrylic resin solution, 13 parts of water-based polyurethane resin, 25 parts of deionized water, 2 parts of dispersant, 12 parts of pigment, 3 parts of calcium carbonate, 0.8 part of polyvinyl alcohol wax, 8 parts of ethanol, 2 parts of anti-settling agent.

[0064] The solid content of the water-based acrylic resin is 30 - 35 wt%, and the viscosity is 700 - 900 MPa·s at 25°C.

[0065] The water-based polyurethane resin used is water-based polyurethane of model PU7307, specifically purchased from Shanghai Belt New Material Technology Co., Ltd.

[0066] The dispersant used is low molecular weight polyethylene glycol, and the molecular weight of the low molecular weight polyethylene glycol is 400 - 600.

[0067] The pigment used is water-based pigment, and the water-based pigments are red, yellow, blue, black, and white water-based pigments. The particle size of the water-based pigment is nanoscale.

[0068] The anti-settling agent used is fumed silica, and the particle size of the fumed silica is 200 - 400 nm.

[0069] The preparation method of the water-based ink for gravure printing of the environmentally friendly plastic film includes the following steps:

[0070] Step 1: Add the dispersant to ethanol and stir evenly, then sequentially add calcium carbonate and the anti-settling agent, and obtain the dispersed filler through constant temperature stirring; the stirring speed of the even stirring is 400 r / min, the temperature of the constant temperature stirring is 35°C, and the stirring speed is 150 r / min;

[0071] Step 2: Add the water-based acrylic resin solution and the water-based polyurethane resin to the reaction kettle and stir at a constant temperature to obtain the mixed material. The temperature of the constant temperature stirring is 140°C, and the stirring speed is 500 r / min;

[0072] Step 3: Add distilled water to the dispersed filler, then sequentially add pigment, polyvinyl alcohol wax, and the mixed material, and stir rapidly to obtain water-based ink. The stirring speed of the rapid stirring is 1500 r / min.

[0073] Comparative Example 2

[0074] Comparative Example 2 used a commercially available water-based ink, specifically purchased from a certain Color Technology Co., Ltd. in Huizhou City.

[0075] Performance Testing

[0076] The water-based inks of Examples 1-3 and Comparative Examples 1-2 were used as test samples, and the performance test results are as follows:

[0077]

[0078] Among them, the temperature for water resistance was 23°C for 24 h, and the yellowing resistance was treated by heating at 220°C for 30 min; the drying rate was the time for UV light to irradiate a 1-mm coating until it was completely dry.

[0079] The above data comparison shows that: from the comparison between Examples 1-3 and Comparative Example 1, the modified calcium carbonate has good surface activity, which not only effectively solves the sedimentation problem of calcium carbonate, but also effectively improves the stable connection between calcium carbonate and other materials by the surface activity, greatly enhancing the stability of calcium carbonate and solving the powdering problem after long-term standing. At the same time, in the staggered combination of water-based polypropylene and water-based polyurethane, with the addition of silicon-oxygen materials, not only the water resistance is greatly improved, but also a stable connection can be formed with the silicon-oxygen materials, improving the internal crosslinking property, making the ink film have advantages such as water resistance, wear resistance, and yellowing resistance; moreover, the flatness of the ink film is better, improving the visual and tactile sensations of the suede ink film and making the printed product of better quality.

[0080] It can be understood that the above specific description of the present invention is only for explaining the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effects; as long as it meets the use requirements, it is within the protection scope of the present invention.

Claims

1. An environmentally friendly water-based ink for gravure printing of plastic films, characterized in that: The mass ratio is: 30-50 parts of water-based acrylic resin liquid, 10-15 parts of water-based polyurethane resin, 20-30 parts of deionized water, 1-2 parts of dispersant, 10-14 parts of pigment, 2-4 parts of modified calcium carbonate, 0.5-1 parts of polyvinyl alcohol wax, 4-10 parts of ethanol, 1-2 parts of anti-settling agent, wherein the modified calcium carbonate adopts silicon-oxygen modified calcium carbonate material.

2. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The waterborne acrylic resin has a solid content of 30-35 wt %, and a viscosity of 700-900 MPa·s at 25° C.

3. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The waterborne polyurethane resin adopts model PU7307 waterborne polyurethane, which is purchased from Shanghai Belt New Material Technology Co., Ltd.

4. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The dispersant is low molecular weight polyethylene glycol, and the weight of the low molecular weight polyethylene glycol is 400-600.

5. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The pigment is water-based pigment, and the water-based pigment is red, yellow, blue, black, and white water-based pigment, and the particle size of the water-based pigment is nanometer level.

6. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The silicon-oxygen modified calcium carbonate material uses the silicon-oxygen structure as a framework to completely wrap the calcium carbonate to form a porous shell on the surface.

7. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The anti-settling agent is fumed silica, and the particle size of the fumed silica is 200-400nm.

8. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 1, characterized in that: The method for preparing the environmentally friendly water-based ink for gravure printing of plastic films comprises the following steps: Step 1, adding a dispersant to ethanol and stirring evenly, then sequentially adding modified calcium carbonate and an anti-settling agent, and stirring at a constant temperature to obtain a dispersed filler; Step 2, adding the aqueous acrylic resin liquid and the aqueous polyurethane resin into a reaction kettle and stirring at a constant temperature to obtain a mixed material; Step 3, adding distilled water to the dispersed filler, and then adding the pigment, polyvinyl alcohol wax and the mixed material in sequence, and stirring rapidly to obtain a water-based ink, wherein the stirring speed of the rapid stirring is 1000-2000 r / min.

9. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 8, characterized in that: The stirring speed for uniform stirring in step 1 is 300-500 r / min, the temperature for constant temperature stirring is 30-40° C., and the stirring speed is 100-200 r / min.

10. The environmentally friendly water-based ink for gravure printing of plastic films according to claim 8, characterized in that: The temperature of the constant temperature stirring in step 2 is 120-150° C., and the stirring speed is 400-600 r / min.

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