Medium-temperature printing ink as well as preparation method and application thereof

Abstract

The invention discloses medium-temperature printing ink as well as a preparation method and application thereof, and aims to solve the problems that the existing ink-jet printing ink is high in curing temperature, insufficient in adhesive force to inert base materials such as glass and ceramic, poor in adaptability to flexible base materials such as soft porcelain and the like. According to the ink, color paste, resin and a solvent form basic slurry, and the basic slurry is matched with an anti-settling agent, an ultraviolet absorbent, a light stabilizer, a dispersing agent and a coalescing agent to form a multifunctional system; the preparation method comprises the following steps: mixing the color paste, the resin and the solvent to form basic slurry, then adding the auxiliary agent according to the mass of the basic slurry, carrying out high-speed dispersion and micron-sized filtration to obtain the medium-temperature ink-jet ink, and rapidly curing the obtained ink to form a film at 150-300 DEG C. Through the synergistic effect of a specific resin structure and the coalescing agent, the ink shows excellent adhesive force, weather resistance and jet stability on glass, ceramic rock plates, soft porcelain materials and other base materials, energy consumption is reduced, printing quality is improved, and the application range of the ink jet technology is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inkjet printing materials, in particular to a medium-temperature printing ink and a preparation method and application thereof. BACKGROUND

[0002] With the advantages of high resolution, non-contact processing mode and adaptation to personalized decoration needs, inkjet printing technology has become a key technical means in the fields of building decoration materials, ceramic pattern making and glass deep processing. With the development of product form diversification in the building material industry, the universality, adhesion, weather resistance and solidification energy consumption of ink have become important factors restricting industrial application. Especially on the surface of inert substrates such as glass and ceramic, traditional ink can only obtain strong adhesion through high-temperature sintering process. However, high-temperature processing not only has huge energy consumption, but also limits equipment configuration, material compatibility range and production flexibility, making it difficult to meet the needs of new flexible building materials.

[0003] The current ceramic ink system mainly used in industry relies on high-temperature sintering to form a stable inorganic network structure, so it generally needs high-temperature solidification above 600℃. Although this high-temperature solidification strategy can obtain strong weather resistance and adhesion, it is obviously not suitable for new building material systems such as soft porcelain and composite boards that are sensitive to temperature. On the other hand, low-temperature or UV-curable inks quickly form films at room temperature or low temperature, but due to their weak resin network structure, they often have insufficient adhesion on low-surface-energy substrates such as glass and ceramic, and insufficient ultraviolet resistance and poor yellowing resistance, making it difficult to provide long-term stable weather resistance in outdoor environments. In addition, the UV ink solidification process requires high equipment investment and high energy consumption, and is sensitive to the surface state of the substrate, which is not conducive to large-scale promotion.

[0004] In contrast, medium-temperature curable ink provides a potential solution. The core idea is to design the resin structure and control the film formation of the system, so that the ink can form a stable film layer in the range of 150-300℃. This not only significantly reduces the overall energy consumption, but also is compatible with most non-temperature-resistant flexible and composite substrates. However, the existing medium-temperature ink system still has many limitations: on the one hand, the film formation and adhesion of the resin system are often difficult to balance; on the other hand, the solvent volatilization behavior and rheological properties are difficult to adapt to the inkjet nozzle, resulting in unstable jetting, poor sedimentation or insufficient storage stability and other problems. More importantly, obtaining a firm adhesion layer on glass and ceramic non-absorbing substrates is still one of the bottlenecks in the industry.

[0005] Therefore, it is of great significance to develop a medium-temperature inkjet ink system that can achieve rapid solidification in the medium-temperature range, has high adhesion, wide compatibility and good jetting stability, to solve the problems of high energy consumption, poor compatibility and limited application in the industry. SUMMARY

[0006] The present application provides a medium-temperature printing ink, a preparation method thereof and application thereof on various substrates to solve the core problems of high solidification temperature, insufficient adhesion or poor jetting stability in the existing ink system.

[0007] The ink system of the present application can form a resin film layer with good adhesion and weather resistance under medium-temperature conditions, while maintaining excellent rheological properties and jet head adaptability by reasonably designing the synergistic ratio of the base slurry and the additive system.

[0008] To solve the above technical problems, the technical solutions adopted by the present application are as follows: The present application provides a medium-temperature printing ink, which is composed of a base slurry and an additive. The base slurry is composed of the following components in mass percentage: color paste 20-60%, resin 20-60%, solvent 10-40%. The additive is added in an amount of 0.1-5% of the total mass of the base slurry, respectively: anti-settling agent 0.1-5%, ultraviolet absorber 0.1-5%, light stabilizer 0.1-5%, dispersant 0.01-2%, leveling agent 0.01-0.3%, defoaming agent 0.1-0.5%, and film-forming aid 2-20%.

[0009] The present application uses a resin that can form a tough resin film layer under medium-temperature conditions as the main film-forming body, controls the flowability through alcohol ether or ester solvents, and further compounds anti-settling agents, light stabilizing systems, and fluorosilicon film-forming aids, thereby achieving controllable jetting, rapid solidification, and weather resistance.

[0010] As a most preferred solution, the color paste is an inorganic pigment color paste. From the aspects of color saturation, durability, and hiding power, the white inorganic pigment can be at least one of titanium white and zinc oxide; the yellow inorganic pigment can be at least one of iron oxide yellow and titanium nickel yellow; the black inorganic pigment can be at least one of carbon black, iron oxide black, and copper chromium black; the red inorganic pigment can be at least one of iron oxide red and cadmium red; and the blue inorganic pigment can be at least one of ultramarine, iron blue, and cobalt blue.

[0011] As a most preferred solution, the resin is at least one of fluorocarbon resin, organic silicon resin, and acrylic resin.

[0012] As a most preferred solution, the solvent is at least one of alcohol ether solvent, ester solvent, or mixed solvent, and more preferably at least one of dipropylene glycol monomethyl ether, propylene glycol ether, or diol ester.

[0013] As a most preferred solution, the film-forming aid is at least one of organic fluorosilicon resin, modified siloxane resin, or a combination thereof.

[0014] As a most preferred solution, the anti-settling agent comprises at least one of polyamide wax, anti-settling polyester or modified bentonite.

[0015] As a most preferred solution, the ultraviolet absorber and light stabilizer comprises at least one of hydroxybenzophenone, hindered amine or ester absorber.

[0016] As a most preferred solution, the dispersant is a polyurethane dispersant or an acrylate dispersant.

[0017] The present application also provides a preparation method of the medium-temperature printing ink, comprising the following steps: (1) The raw materials are weighed according to the proportion, and the color paste, resin and solvent are mixed to form a base paste; (2) The anti-settling agent, ultraviolet absorber, light stabilizer, dispersant and film-forming aid are added to the base paste, and a blast-proof disperser is used to stir and disperse at 1500-3000 r / min for 20-80 min; (3) Then vacuum filtration is performed through a 0.5-5 μm filter to obtain the medium-temperature printing ink.

[0018] As a most preferred solution, the base paste is kept at 20-40℃ during the mixing process.

[0019] As a most preferred solution, the viscosity of the ink is controlled at 7-35 mPa•s, and the particle size D90 of the ink is less than 1 μm.

[0020] The present application also provides an application of the medium-temperature printing ink in inkjet printing, comprising the following steps: (1) Printing: the ink is sprayed to the surface of a printing substrate to form a pattern; (2) Drying: the printed substrate is dried to solidify and form a resin film layer.

[0021] As a most preferred solution, the printing substrate is at least one of soft porcelain, ceramic rock plate or glass.

[0022] As a most preferred solution, the drying temperature is 150-300℃.

[0023] As a most preferred solution, the drying time is 30-60 min.

[0024] As a most preferred solution, the hardness of the resin film layer is greater than 5H, and the weather resistance time is more than 1500 h.

[0025] The present application also provides a medium-temperature inkjet printer, wherein the inkjet printer comprises an ink supply module and a print head, and the ink supply module contains a printing ink, which is the above-mentioned medium-temperature printing ink.

[0026] Compared with the prior art, the present application has the following advantages: (1) The resin system selected in the present application can complete curing at medium temperature (150-300 DEG C), avoiding the problems of high energy consumption and limited substrate caused by traditional high-temperature ink curing at above 600 DEG C, so that the ink can be widely applied to soft porcelain, ceramic rock plate, glass and other substrates sensitive to temperature or special in shape; (2) The fluorosilicon film-forming additive compounded in the present application and the low-surface-energy resin jointly act to significantly improve the adhesion, flexibility and weather resistance of the cured film layer, so that the printed pattern is resistant to rubbing, aging and falling off; (3) By optimizing the solvent system and the type of dispersant, the viscosity of the ink is stable, and it is suitable for various industrial nozzles, and the jetting process is smooth, and it is not easy to produce blocked heads and satellite points; (4) The ink has less volatile matter during medium-temperature curing, forms film quickly, and has excellent ultraviolet resistance and light stability, and can be used for a long time in building exterior wall decoration and decoration scenes susceptible to environmental influences; (5) The composition range of the ink of the present application is wide, and the formula is compatible, which can be flexibly adjusted according to the requirements of different substrates, and is convenient for large-scale production and industrial promotion. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Digital photo of the medium-temperature printing ink prepared in Example 1.

[0028] Figure 2 Pattern photo of the medium-temperature printing ink prepared in Example 1 sprayed on the surface of glass. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with the drawings and specific examples. It should be understood that these examples are only used to illustrate the present application and are not used to limit the scope of the present application. The operation methods not specified in the following examples are usually carried out according to conventional conditions or according to the conditions recommended by the manufacturers.

[0030] The color paste used in the following examples is inorganic pigment color paste. From the color saturation, durability, hiding power and the like, the white inorganic pigment can be at least one of titanium white and zinc oxide; the yellow inorganic pigment can be at least one of iron oxide yellow and titanium nickel yellow; the black inorganic pigment can be at least one of carbon black, iron oxide black and copper chromium black; the red inorganic pigment can be at least one of iron oxide red and cadmium red; and the blue inorganic pigment can be at least one of ultramarine, iron blue and cobalt blue.

[0031] The examples of the present application take titanium white paste as an example to prepare ink.

[0032] Example 1: When preparing the ink base slurry, 40% titanium white paste, 20% fluorocarbon resin and 40% dipropylene glycol monomethyl ether were taken by mass percentage and added into the stirring kettle. The base slurry was uniformly mixed by stirring at a speed of 600 r / min for 20 min in the stirring kettle.

[0033] Then, 0.1% polyamide wax, 0.1% hydroxybenzophenone, 2% polyurethane dispersant and 10% organic fluorosilicon resin were added by mass percentage of the total mass of the base slurry, wherein the polyamide wax was used as a sedimentation inhibitor to establish a reasonable yield stress to inhibit the sedimentation of the color paste, and the organic fluorosilicon resin was used as a film-forming aid, which was a resin type additive with fluorosilicon structural units, to enhance the weather resistance of the final film layer and the interfacial wetting ability on the soft porcelain surface. After adding the additives, the system entered the high-speed dispersion stage, the speed was increased to 2000 r / min and the stirring was continued for 40 min, so that the solvent, the color paste, the resin and the various additives formed a stable composite dispersion system.

[0034] After the dispersion step was completed, the ink was filtered through a 1 μm polytetrafluoroethylene filter to remove possible coarse particles or agglomerates to ensure that the particle size requirement for the inkjet print head was met. The obtained ink appeared as a uniform and stable fluid state without obvious stratification or flocculation. The viscosity was measured by a digital viscometer, the rotor was set to 0#, the speed was 6, and the viscosity was measured to be 7 mPa·s, which met the viscosity standard of normal pressure inkjet printing.

[0035] Figure 1 For the digital photo of the warm printing ink in Example 1, it can be seen that the ink is stably dispersed.

[0036] Example 2: The ink was prepared by the same method as in Example 1, and the specific ink formula was as follows: the base slurry was 50% titanium white paste, 40% acrylic resin and 10% glycol diacetate; the addition amount of each additive was 0.1% polyamide wax, 0.1% hydroxybenzophenone, 2% polyurethane dispersant and 10% organic fluorosilicon resin, based on the mass of the base slurry. The ink prepared in Example 1 was loaded into a piezoelectric inkjet printing device, and a pattern was printed on a glass substrate. After printing, the sample was placed in a ventilated heating oven at 200°C and dried for 50 min to cure the resin system. The cured film layer was uniform and dense, and the surface was smooth without cracks. The film layer adhesion was evaluated by a cross-hatch adhesion test, and the result showed 0-1 level, indicating that the ink of the present application had very high adhesion reliability on the soft porcelain surface. Further bending test showed that the sample was subjected to 50 times of reciprocating bending at a bending radius of 5 cm, and the film layer had no peeling or cracking phenomenon, indicating that the film layer had both flexibility and mechanical stability.

[0037] Figure 2The pattern photo sprayed on the glass surface of Example 1 shows that the pattern edge is clear and the color is uniform without ink drop diffusion. The result shows that the ink of the present application has good interface adaptability with the soft porcelain material, the process is simple and rapid curing, and is suitable for industrial production.

[0038] Example 4: The difference from Example 3 is only that the printing substrate is soft porcelain material, and the rest is the same.

[0039] Example 5: The difference from Example 3 is only that the printing substrate is ceramic rock plate, and the rest is the same. Comparative Example 1: In this comparative example, the film-forming aid described in Example 1 is removed, and the rest of the conditions are the same as in Example 1. The adhesion of the ink on the soft porcelain surface is obviously insufficient, and the crosshatch test result is 3-4 levels, and the film layer is prone to cracking or partial peeling in the bending test. The result shows that the addition of the film-forming aid plays a key role in improving the adhesion and flexibility under medium temperature conditions.

[0040] Comparative Example 2: In this comparative example, all the medium temperature film-forming resins used in Example 1 are replaced with conventional acrylic resins (without fluorine-silicon structure), and the rest of the formulation and process conditions remain the same. The film layer prepared and cured after water immersion, crosshatch and ultraviolet aging tests shows that although the adhesion can still reach 2-3 levels in the short term, obvious optical yellowing and edge blistering occur after 500 h of ultraviolet accelerated aging, and the weather resistance and long-term color fastness are inferior to Example 1; the result shows that the chemical composition of the resin (especially the fluorine / silicon modified unit) is crucial to the long-term weather resistance and anti-yellowing performance of the film layer.

[0041] Comparative Example 3: In this comparative example, the solvent system is replaced by high-volatility low-boiling-point solvents (for example, a mixed solvent mainly containing ethanol) from the medium-volatility alcohol ether solvents of Example 1, and the rest of the formulation remains unchanged. It is found during the test process that the ink has obvious volatilization loss during preparation and filling, the droplet formation is unstable during inkjet printing, the nozzle end is accompanied by dryness, the nozzle clogging rate significantly increases (about 3 times the number of clogging compared with Example 1), and the printed pattern edge appears stringing and ink overflow. The cured film layer has different degrees of surface holes and micro-wrinkles, resulting in a decrease in optical uniformity, indicating that the solvent evaporation rate has a significant effect on the inkjet processing adaptability and the integrity of the cured film layer.

[0042] Performance Test Adhesion test: test according to the standard of “GB / T1720-1979 Paint Film Adhesion Test Method”; Hardness test: test according to the standard of “GB / T6739-1996 Pencil Method for Testing Paint Film Hardness”; Color test: test according to the standard of GB / T13217.1-2020 Ink color and tinting power test method; Printing effect test: print the ink with high-speed rotary printing machine, the speed is 200 m / min, print Chinese and numbers with Chinese font No. 8, evaluate the quality according to the clear degree, wherein A represents clear and smooth line, B represents relatively clear and slightly thick line, C represents with burr and blur; the test results are shown in Table 1.

[0043] Table 1 Performance test results As can be seen from Table 1, the samples obtained by the above examples can all achieve the technical index of ink coating.

[0044] In addition, it should be understood that, after reading the above description of the present application, those skilled in the art can make various modifications or modifications to the present application, and these equivalent forms also fall within the scope defined by the claims attached to the present application.

Claims

1. A mid temperature printing ink, characterized by The medium-temperature printing ink is composed of a base paste and additives; The base paste is composed of the following components in percentage by mass: color paste 20-60%, resin 20-60%, solvent 10-40%; The additives are added in the following amounts based on the total mass of the base paste: anti-settling agent 0.1-5%, ultraviolet absorber 0.1-5%, light stabilizer 0.1-5%, dispersant 0.01-2%, leveling agent 0.01-0.3%, defoaming agent 0.1-0.5%, and film-forming aid 2-20%.

2. The mid-range printing ink according to claim 1, characterized in that, The color paste is inorganic color paste; The resin is at least one of fluorocarbon resin, silicone resin, and acrylic resin; The solvent is alcohol ether solvent, ester solvent, or mixed solvent thereof; preferably, the solvent is one of dipropylene glycol monomethyl ether, propylene glycol ether, or diol ester.

3. The mid-range printing ink according to claim 1, characterized in that, The film-forming aid is one or more of fluorocarbon resin, silicone resin, silazane resin, and modified siloxane resin; The anti-settling agent is at least one of polyamide wax, anti-settling polyester, and modified bentonite; The ultraviolet absorber and light stabilizer are at least one of hydroxybenzophenone, hindered amine, and ester absorber; The leveling agent is at least one of polyether-modified polysiloxane, acrylate, and fluorocarbon compound; The defoaming agent is at least one of polyether, polyether-modified polysilicon, and non-silicon high polymer; The dispersant is polyurethane dispersant or acrylate dispersant.

4. The mid-range printing ink according to claim 1, characterized in that, The viscosity of the ink is 7-35 mPa·s, and the ink particle size D90 is less than 1 μm.

5. A method of preparing a medium temperature printing ink as defined in any one of claims 1 to 4, characterized in that The method comprises the following steps: (1) The raw materials are weighed according to the ratio, the color paste, resin, and solvent are mixed to form a base paste; (2) The anti-settling agent, ultraviolet absorber, light stabilizer, dispersant, and film-forming aid are added to the base paste, and a blast-proof disperser is used to stir and disperse at 1500-3000 r / min for 20-80 min; (3) Vacuum filtration is performed through a 0.5-5 μm filter to obtain the medium-temperature printing ink.

6. The method of making a mid-range printing ink according to claim 5, characterized in that, The temperature of the base paste is kept at 20-40℃ during the mixing process.

7. Use of a mid temperature printing ink according to any one of claims 1 to 4 in inkjet printing, characterized in that The method comprises the following steps: (1) Printing: the ink is sprayed onto the surface of a printing substrate to form a pattern; (2) Drying: the printed substrate is dried to cure and form a resin film layer.

8. Use according to claim 7, characterized in that, The printing substrate is at least one of soft porcelain, ceramic rock plate, glass, or plastic powder spraying substrate.

9. Use according to claim 7, characterized in that, The drying temperature is 150-300℃, the drying time is 30-60 min, and the hardness of the resin film layer is greater than 5H, and the weather resistance time is more than 1500 h.

10. A mid temperature inkjet printer characterized by, The inkjet printer comprises an ink supply module and a print head, wherein the ink supply module contains the printing ink, which is the medium-temperature printing ink according to any one of claims 1-4.

Images