Color paste as well as preparation method and application thereof

Abstract

The invention relates to the technical field of printing supplies, in particular to color paste as well as a preparation method and application thereof. The color paste provided by the invention is prepared from the following raw materials in percentage by mass: 60-80% of titanium dioxide, 6-28% of a dispersing agent, 3-10% of an organic solvent and the balance of deionized water, the dispersing agent comprises an acrylic block copolymer, and the amine value of the acrylic block copolymer is 15-20mg KOH / g. The acrylic block copolymer with the amine value of 15-20 mg KOH / g is used as a dispersing agent in the color paste, a stable adsorption layer can be formed on the surfaces of titanium dioxide particles through the acrylic block copolymer containing the amine groups, direct contact and aggregation among the particles are prevented, the dispersity and long-term stability of the color paste are improved, and the color paste has the advantages of being high in stability and good in stability. Meanwhile, negative charges of titanium dioxide are neutralized by amino, electrostatic repulsion among particles is reduced, titanium dioxide agglomeration is prevented, and the dispersity of titanium dioxide in the color paste is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of printing consumables, and in particular to a color paste and a preparation method and application thereof. Background Art

[0002] Thermal bubble printing technology is a common inkjet printing technology that uses electric current to pass through a heating element to quickly heat the ink in the ink chamber, causing the local ink to evaporate quickly to generate bubbles. The pressure generated by the expansion of the bubbles sprays tiny ink droplets onto the printing medium to form text or images. After the bubbles disappear, the ink chamber quickly replenishes the ink through capillary action to prepare for the next spray. The ink used in thermal bubble printing technology requires excellent adhesion and quick drying properties to maintain stable performance on the printing medium.

[0003] At present, most of them adjust the content of surfactants or other solvents in the ink or the selection of materials to improve the adhesion and quick-drying performance of the ink. At the same time, the colorant content is reduced to reduce the viscosity of the ink to ensure the ink quality. However, the adjustment of materials such as surfactants affects the glossiness and reflectivity of the ink to light, and the reduction of colorant content affects the uniformity of the distribution of colorant in the ink, resulting in poor ink whiteness effect. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor ink whiteness effect under the premise of maintaining low viscosity ink adhesion and quick drying performance in the prior art, thereby providing a color paste and its preparation method and application.

[0005] To this end, the present invention provides a color paste, which is made of the following raw materials in mass fraction: 60%-80% titanium dioxide, 6%-28% dispersant, 3-10% solvent, and the rest is deionized water, wherein the dispersant includes an acrylic block copolymer containing an amine group, and the amine value of the acrylic block copolymer is 15-20 mg KOH / g.

[0006] Preferably, the dispersant is PX 4780, PX 4787 and At least one of PX 4310.

[0007] In some embodiments, the color paste further includes a defoamer, and the mass fraction of the defoamer is 0.1%-0.3%.

[0008] Preferably, the defoaming agent is a polyether-siloxane copolymer.

[0009] More preferably, the defoaming agent is at least one of a polyether-modified polydimethylsiloxane copolymer, a polyether-polysiloxane copolymer, and a polyether-modified silicone copolymer.

[0010] In some of the embodiments, the particle size of titanium dioxide in the color paste is 300nm-700nm, preferably 350nm-650nm.

[0011] In some embodiments, the structural formula of the solvent is as shown in formula (I),

[0012]

[0013] Wherein, R1, R2 or R3 are independently selected from at least one of a C1-C6 alkyl group or a hydrogen atom, n is 1-6, and m is 1-6.

[0014] Preferably, in the formula (I), R1, R2 or R3 is independently selected from a C1-C2 alkyl group, n is 1-2, and m is 1-2.

[0015] More preferably, the solvent is at least one of dipropylene glycol butyl ether and dipropylene glycol methyl ether.

[0016] On the other hand, the present invention provides a method for preparing the above-mentioned color paste, comprising the following steps: mixing various raw materials according to a proportion to obtain the color paste.

[0017] In some of the embodiments, titanium dioxide and a solvent are first mixed under stirring to obtain a mixed liquid, and then a dispersant is added to the mixed liquid. When titanium dioxide and the solvent are mixed, ultrasonic oscillation is adopted, and the frequency of the ultrasonic oscillation is 19.5kHz to 20.5kHz. When the dispersant and the mixed liquid are mixed, they are stirred at a speed of 2000rpm-2800rpm for 1-1.5h, and then ground at a speed of 2000rpm-2200rpm.

[0018] Meanwhile, the present invention also provides an ink, which includes the above-mentioned color paste or the color paste prepared by the above-mentioned color paste preparation method.

[0019] In some of the embodiments, the mass fraction of the color paste in the ink is 15%-35%.

[0020] In some of the embodiments, the ink further includes a resin, a wetting agent, an organic solvent, and a surfactant.

[0021] Preferably, the resin is at least one of a polyurethane resin and a modified polyurethane resin.

[0022] More preferably, the polyurethane resin is a polyurethane resin of model RL-02 or RL-11 produced by DIC Corporation.

[0023] The modified polyurethane resin is a modified polyurethane resin obtained by modifying polyurethane by conventional means.

[0024] The wetting agent is an organic substance containing an affinity group, and the organic substance containing an affinity group includes at least one of a polymer containing an affinity group and a polyhydroxy organic substance.

[0025] Preferably, the polyhydroxy organic substance is at least one of glycerol and an alcohol solvent, and the alcohol solvent is at least one of propylene glycol, butylene glycol, isopropanol and ethanol.

[0026] Preferably, the wetting agent of the polymer containing affinity groups is of at least one of BYKJET-9175 and TEGO Dispers760W.

[0027] The surfactant is a nonionic surfactant.

[0028] Preferably, the model of the surfactant is Surfynol465.

[0029] The ink also includes a bactericide, and the concentration of the bactericide in the ink is 0.1wt%-1wt%.

[0030] The fungicide is 1,2-benzisothiazolin-3-one (BIT20).

[0031] In some of the embodiments, the content of the resin in the ink is 8wt%-12wt%, the content of the wetting agent is 0.5wt%-3wt%, the content of the organic solvent is 56wt%-75wt%, and the content of the surfactant is 0.5wt%-1wt%.

[0032] In some embodiments, the boiling point of the organic solvent is less than or equal to 70°C.

[0033] In some embodiments, the organic solvent includes a first solvent and a second solvent, the boiling point of the second solvent is lower than that of the first solvent, and the mass ratio of the first solvent to the second solvent is (3-9):(2-5).

[0034] Preferably, the first solvent is a C2-C3 alcohol solvent,

[0035] Preferably, the second solvent is at least one of C1-C6 alkanes or methanol.

[0036] More preferably, the second solvent is n-hexane.

[0037] Furthermore, the color paste and the color paste and ink prepared by the color paste preparation method provided by the present invention can be applied to thermal foaming printing, and the printed substrate is a non-permeable substrate.

[0038] Among them, the non-permeable substrate is a material that the printing material cannot penetrate into the interior of the substrate, and the surface of the non-permeable substrate is usually smooth and dense.

[0039] Preferably, the non-permeable substrate is at least one of plastic, metal, glass, ceramic, coated paper, and wood.

[0040] The material of the plastic includes at least one of polyvinyl chloride (PVC), polyethylene terephthalate (PET) and polypropylene (PP). The metal includes at least one of aluminum plate and stainless steel, preferably steel. The glass is at least one of transparent glass or frosted glass. The ceramic includes at least one of ceramic tile or tableware. The coated paper includes glossy coated paper or matte coated paper.

[0041] The technical solution of the present invention has the following advantages:

[0042] 1. A color paste provided by the present invention is made of the following raw materials in mass fraction: 60%-80% titanium dioxide, 6%-28% dispersant, 3-10% organic solvent, and the rest is deionized water, wherein the dispersant comprises an acrylic block copolymer, and the amine value of the acrylic block copolymer is 15-20 mg KOH / g. The present invention uses an acrylic block copolymer with an amine value of 15-20 mg KOH / g as a dispersant in a color paste, and utilizes the amine group in the acrylic block copolymer. On the one hand, the acrylic block copolymer containing the amine group can form a stable adsorption layer on the surface of titanium dioxide particles, providing a steric hindrance effect, preventing direct contact and aggregation between particles, and improving the dispersibility and long-term stability of the color paste; on the other hand, the amine group is utilized to neutralize the negative charge of titanium dioxide, reducing the electrostatic repulsion between particles. At the same time, the amine group can reduce the interfacial tension between titanium dioxide and the dispersant, improve the wettability of titanium dioxide, prevent titanium dioxide from agglomerating, and improve the dispersibility of titanium dioxide in the color paste. At the same time, the present invention controls the amine value of the acrylic front-stage copolymer used as a dispersant to be 15-20 mg KOH / g, so that the titanium dioxide particles in the color paste maintain good dispersibility and stability, achieve an increase in the titanium dioxide content in the color paste, and enhance the whiteness of the color paste.

[0043] 2. The present invention provides a color paste, wherein the particle size of titanium dioxide in the color paste is 350nm to 650nm. The present invention limits the particle size of titanium dioxide in the color paste, improves the whiteness of the color paste, enhances the hiding power, and improves the adaptability of the color paste in the application field.

[0044] 3. The ink provided by the present invention comprises the above-mentioned color paste. The ink provided by the present invention has the characteristics of strong dispersibility, good stability and quick drying.

[0045] 4. The present invention provides an ink, wherein the resin is at least one of a polyurethane resin and a modified polyurethane resin. The present invention utilizes the dispersant in the color paste to react with the isocyanate group in the polyurethane resin and the modified polyurethane resin, thereby further improving the wettability of the titanium dioxide surface in the color paste, reducing the difficulty of ink preparation, and at the same time, improving the cohesion and adhesion of the ink layer, thereby enhancing the mechanical properties and chemical resistance of the ink-formed pattern coating.

[0046] 5. The present invention provides an ink, wherein the boiling point of the solvent in the ink is less than or equal to 70°C. The present invention uses a solvent with a boiling point less than or equal to 70°C as a raw material in the ink, and the obtained ink has a quick-drying property, can reduce the fluidity of the ink on substrates that are difficult to adhere to, such as steel, and improve the quality of the ink image.

[0047] 6. The present invention provides an ink, wherein the organic solvent comprises a first solvent and a second solvent, and the boiling point of the second solvent is lower than that of the first solvent. Since the use of an organic solvent with a boiling point lower than 70°C in the ink will cause the ink stability to decrease, which will not only cause the nozzle to be blocked, but also cause the adhesion between the ink and the substrate to decrease, affecting the effect of the printed image, the present invention uses a compound of two solvents to reduce the possibility of a single solvent being deposited on the nozzle, adjust the surface tension of the ink, and improve the drying rate and stability of the ink, so that the volatilization of the ink can be hierarchical, can adapt to the complex and changeable ink printing process, and the printed pattern has better accuracy.

[0048] 7. The color paste, the color paste preparation method and the ink provided by the present invention can be applied to thermal foaming printing. The preferred printing substrate is a non-permeable substrate. The ink provided by the present invention has good adhesion and quick drying properties. The drying time when printed on a non-permeable substrate, especially on steel, is only 2s. DETAILED DESCRIPTION

[0049] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0050] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0051] The model of the ultrasonic mixer was SCIENTZ-750F, purchased from Ningbo Xinzhi Biotechnology Co., Ltd.;

[0052] TEGO810, that is Foamex 810, a highly efficient defoamer concentrate based on polyether siloxane technology, is particularly suitable for aqueous systems, has excellent defoaming effect during the grinding stage and has good compatibility.

[0053] Dispersant BYK-163 was purchased from BYK, Germany, and dispersants Dispex Ultra PX 4575 and BASF Efka PX4701, PX 4780, PX 4787 and PX 4310 was purchased from BASF.

[0054] Polyurethane was purchased from DIC Corporation with models RL-02 and RL-11.

[0055] It should be noted that the method for determining the particle size of titanium dioxide in the second material in the examples and comparative examples of the present invention is the same as that in Example 1.

[0056] Example 1

[0057] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are as follows:

[0058] (1) 60 g of nano-TiO2 powder, 0.1 g of defoamer and 4.5 g of dipropylene glycol butyl ether were added to a SCIENTZ-750F ultrasonic mixer and stirred at a frequency of 20 kHz to form a uniform slurry, 6 g of dispersant was added thereto, the volume was fixed to 100 g with water, and the mixture was mixed continuously to form a first material, wherein the defoamer was of model TEGO-10, and the dispersant was an acrylic block copolymer of model PX 4780, amine value 20 mg KOH / g;

[0059] (2) putting the first material into a mixer (model: VMA DISPERMAT CN70), stirring at 2200 rpm for 1 hour, and obtaining the second material;

[0060] (3) putting the second material into a horizontal sand grinder and grinding it in a cycle at 2200 rpm to make the particle size of titanium dioxide in the second material reach 500 nm, and filtering to obtain a white color paste;

[0061] The method for determining the particle size of titanium dioxide in the second material is to place the sample on a LA-960V2 laser particle size analyzer for measurement. The laser in the instrument irradiates the sample, and the light scattered by the particles is captured by the detector. The data of key particle sizes including D10, D50 and D90 are then analyzed through software, where the average particle size, i.e., D50, is the particle size of titanium dioxide in the second material.

[0062] Example 2

[0063] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are the same as those of Embodiment 1, except that the particle size of titanium dioxide in the second material in step (3) is 350 nm.

[0064] Example 3

[0065] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are the same as those of Embodiment 1, except that the particle size of titanium dioxide in the second material in step (3) is 650 nm.

[0066] Example 4

[0067] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are the same as those of Example 1, except that the particle size of titanium dioxide in the second material in step (3) is 300 nm.

[0068] Example 5

[0069] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are the same as those in Embodiment 1, except that the particle size of titanium dioxide in the second material in step (3) is 700 nm.

[0070] Example 6

[0071] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are as follows:

[0072] (1) 80 g of nano-TiO2 powder, 0.3 g of defoamer and 3 g of dipropylene glycol methyl ether were added to an ultrasonic mixer and stirred at a frequency of 19.5 kHz to form a uniform slurry, and then 15 g of dispersant was added thereto, and the volume was fixed to 100 g with water, and the mixing was continued to form a first material, wherein the defoamer was TEGO-10, and the dispersant was an acrylic block copolymer. PX 4780, amine value 20 mg KOH / g;

[0073] (2) putting the first material into a mixer and stirring at high speed for 1.5 hours to obtain the second material;

[0074] (3) The second material is placed in a horizontal sand grinder and circulated at 2000 rpm to make the particle size of titanium dioxide in the second material reach 500 nm. A white color paste is obtained after filtering.

[0075] Example 7

[0076] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are as follows:

[0077] (1) 70 g of nano-TiO2 powder, 0.2 g of defoamer and 10 g of dipropylene glycol methyl ether were added to an ultrasonic mixer and stirred at a frequency of 20.5 kHz to form a uniform slurry, and then 10 g of dispersant was added thereto, and the volume was fixed to 100 g with water, and the mixing was continued to form a first material, wherein the defoamer was TEGO-10, and the dispersant was an acrylic block copolymer. PX 4787, amine value 15 mg KOH / g;

[0078] (2) putting the first material into a mixer and stirring at high speed for 1.5 hours to obtain the second material;

[0079] (3) The second material is placed in a horizontal sand grinder and circulated at 2000 rpm to make the particle size of titanium dioxide in the second material reach 500 nm. A white color paste is obtained after filtering.

[0080] Example 8

[0081] This embodiment provides a method for preparing a color paste, and the specific steps and parameters are as follows:

[0082] (1) 60 g of nano-TiO2 powder, 0.2 g of defoamer and 8 g of dipropylene glycol methyl ether were added to an ultrasonic mixer and stirred at a frequency of 20 kHz to form a uniform slurry, and then 28 g of dispersant was added thereto, and the volume was fixed to 100 g with water, and the mixing was continued to form a first material, wherein the defoamer was TEGO-10 and the dispersant was an acrylic block copolymer. PX 4310, amine value 20 mg KOH / g;

[0083] (2) putting the first material into a mixer and stirring at high speed for 1.5 hours to obtain the second material;

[0084] (3) The second material is placed in a horizontal sand grinder and circulated at 2000 rpm to make the particle size of titanium dioxide in the second material reach 500 nm. A white color paste is obtained after filtering.

[0085] Comparative Example 1

[0086] This comparative example provides a method for preparing a color paste. The specific steps and parameters are the same as those of Example 1, except that a dispersant of equal mass and model number BYK-163 is used to replace the dispersant in step (1), and the amine value of model number BYK-163 is 10 mg KOH / g.

[0087] Comparative Example 2

[0088] This comparative example provides a method for preparing a color paste. The specific steps and parameters are the same as those in Example 1, except that a dispersant of the same mass as Dispex Ultra PX 4575 is used to replace the dispersant in step (1), and the amine value of Dispex Ultra PX 4575 is 0 mg KOH / g.

[0089] Comparative Example 3

[0090] This comparative example provides a method for preparing a color paste. The specific steps and parameters are the same as those in Example 1, except that an equal mass of BASF Efka PX4701 (formerly Efka 7701) is used to replace the dispersant in step (1), and the amine value of BASF Efka PX4701 is 40 mg KOH / g.

[0091] Application Example 1 to Application Example 11

[0092] This application example provides a series of ink preparation methods. The specific steps and parameters are as follows:

[0093] At 25°C, 10g of polyurethane resin (purchased from DIC, model RL-02), 2g of propylene glycol, 36g of n-hexane, 26g of ethanol, 1g of surfactant (Surfynol 465), 0.2g of fungicide (BIT20), and 20g of color paste were added to a volume of 100g with deionized water, stirred at 750rpm for 5min, and then stirred at 1000rpm for 10min to form ink.

[0094] The color pastes are the color pastes provided in Examples 1-8 and Comparative Examples 1-3 respectively.

[0095] Application Example 12

[0096] This application example provides a method for preparing an inkjet printing ink. The specific steps and parameters are the same as those of Application Example 1, except that 36 g of ethanol is used instead of n-hexane.

[0097] Application Example 13

[0098] This application example provides a method for preparing an inkjet printing ink. The specific steps and parameters are the same as those of Application Example 1, except that 26 g of n-hexane is used instead of ethanol.

[0099] Application Example 14

[0100] This application example provides a series of ink preparation methods. The specific steps and parameters are as follows:

[0101] At 25°C, 8g of polyurethane resin (purchased from DIC, model RL-11), 0.5g of wetting agent (model BYKJET-9175), 21g of n-hexane, 35g of ethanol, 0.5g of surfactant (Surfynol465), 0.1g of fungicide (BIT20), water and 32g of color paste were diluted to 100g with deionized water, stirred at 750rpm for 5min, and then stirred at 1000rpm for 10min to form ink.

[0102] The color pastes are the color pastes provided in Example 1.

[0103] Application Example 15

[0104] This application example provides a series of ink preparation methods. The specific steps and parameters are as follows:

[0105] At 25°C, 8g of polyurethane resin (purchased from DIC, model RL-02), 0.5g of wetting agent (model TEGO Dispers 760W), 42g of n-hexane, 30g of ethanol, 0.5g of surfactant (Surfynol 465), 1g of fungicide (BIT20) water and 15g of color paste were diluted to 100g with deionized water, stirred at 750rpm for 5min, and then stirred at 1000rpm for 10min to form ink, wherein the color pastes were the color pastes provided in Example 1.

[0106] Experimental example

[0107] The viscosity, adhesion, whiteness, stability, and standby performance, drying speed, and smoothness of the inks prepared according to Examples 1-15 were tested. The test results are shown in Table 1, where:

[0108] Ink viscosity test method:

[0109] Test according to GB / T 13217.4-2020 and record the viscosity value.

[0110] The test method for ink adhesion is as follows:

[0111] Print the ink on the substrate (steel), rub it 20 times with your hands or rub it 10 times with paper, and then observe the printed code or handwriting.

[0112] Definition A means that the printed code or handwriting is clearly visible, without ink leakage and no linear defects; Definition B means that the printed code or handwriting is recognizable, with minor ink leakage and minor linear defects; Definition C means that the printed code or handwriting is barely recognizable, with ink leakage and wider linear defects; Definition D means that the printed code or handwriting is blurred and unrecognizable.

[0113] Ink whiteness test method:

[0114] After the ink is loaded into the ink cartridge, it is printed on the substrate (steel) by the machine. After a drying time of 2 seconds, a visual judgment is made. The visual judgment rating ranges from 1 to 5, with 1 representing the worst whiteness, the larger the number, the better the whiteness, and 5 representing the best whiteness.

[0115] Ink stability test program:

[0116] After the ink is loaded into the ink cartridge, let it sit for more than 3 months and then compare the printing results with those without the ink cartridge to observe the changes.

[0117] Definition A means that the printing effect before and after does not change, and the printed code or handwriting is clearly visible;

[0118] Definition B means that the printing effect before and after has little change, the printed code or handwriting is clearly visible, but the whiteness is slightly reduced, or the printed code or handwriting has minor defects;

[0119] Definition C means that the printing effect before and after changes greatly, and the printed code or handwriting is not clear.

[0120] Standby performance test method:

[0121] Take the ink and put it into the ink cartridge. Use the thermal printer to print for 1 hour without any treatment. Set the machine not to clean or flash. Operate the nozzle to enter the empty window state (suspend the nozzle in the air). Print the test strip after the empty window is full for 5 minutes, 10 minutes, and 15 minutes. The ambient temperature is controlled at 25℃ and the ambient humidity is controlled at 40% to 50% during the printing and standby stages.

[0122] Definition A is to print the test strip after the blank window for 15 minutes, and the writing is clear and without defects;

[0123] Definition B is to print the test strip after the blank window is 10 minutes, and the writing is clear and without defects;

[0124] Define C as printing a test strip after a blank window of 5 minutes, with clear and flawless writing;

[0125] Define D as printing a test strip after a blank window of 5 minutes, with defective characters.

[0126] Drying speed test method:

[0127] After loading the ink into the ink cartridge, print on the substrate (steel) on the machine. After 2s to 5s of drying time, rub it with your fingers or wipe it with a non-woven cloth to observe the printing effect.

[0128] Definition A means that the printed code or handwriting remains unchanged and is still clearly visible;

[0129] Definition B means that the printed code or handwriting has little variation and slight burrs;

[0130] C is defined as the printed code or handwriting being too large and blurry to be recognized.

[0131] Fluency test method:

[0132] Put the ink into the ink cartridge, use all the ink in one ink cartridge for printing test on the machine, and observe the printing effect;

[0133] Definition A means that there will be no interruption during printing, and the printed characters will have no breakpoints;

[0134] Definition B means that no discontinuity is observed during printing, but the printed characters have breakpoints;

[0135] Definition C means that there is a jam during printing and the printed characters are defective.

[0136] Table 1 Ink performance test results

[0137]

[0138]

[0139] According to the data in Table 1, compared with Comparative Example 1 using a high molecular weight wetting dispersant BYK-163, which contains a high molecular weight block copolymer with a pigment affinity group and an amine value of 10 mg KOH / g, the final ink viscosity is high, the adhesion and fluidity are poor, and the whiteness value is low. Comparative Example 2 uses an acrylic acid-blocked copolymer dispersant DispexUltra PX 4575 with an amine value of 0, and the final ink viscosity is high, and the whiteness and adhesion performance are poor. Comparative Example 3 uses an acrylic acid-blocked copolymer dispersant BASF Efka with an amine value of 40 mg KOH / g PX4701, because the amine value of the dispersant is too high, the electrostatic repulsion with the dioxide peptide is too strong, resulting in poor dispersibility, poor whiteness, and poor covering power. At the same time, the dispersant will over-react with the polyurethane in the ink, resulting in a significant decrease in the adhesion of the ink. The dispersant provided by the present invention can reduce the viscosity of the ink, improve the adhesion and stability, and has a faster drying speed. At the same time, it greatly improves the whiteness printed on the substrate and enhances the covering power.

[0140] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A color paste, characterized in that: The method comprises the following raw materials by mass fraction: 60%-80% titanium dioxide, 6%-28% dispersant, 3%-10% solvent, and the rest is deionized water. The dispersant comprises an acrylic block copolymer containing an amine group, and the amine value of the acrylic block copolymer is 15 mg KOH / g to 20 mg KOH / g.

2. The color paste according to claim 1, characterized in that The color paste further includes a defoamer, the mass fraction of the defoamer is 0.1%-0.3%; and / or, The particle size of titanium dioxide in the color paste is 300nm-700nm, preferably 350nm-650nm; The structural formula of the solvent is shown in formula (I), Wherein, R1, R2 or R3 are independently selected from at least one of a C1-C6 alkyl group or a hydrogen atom, n is 1-6, and m is 1-6.

3. The color paste according to claim 2, characterized in that: The defoamer is a polyether-siloxane copolymer; In the formula (I), R1, R2 or R3 are independently selected from C1-C2 alkyl groups, n is 1-2, and m is 1-2.

4. A method for preparing the color paste according to any one of claims 1 to 3, characterized in that: The following steps are included: The raw materials are mixed according to a proportion to obtain a color paste.

5. The method for preparing the color paste according to claim 4, characterized in that: Under stirring, titanium dioxide and solvent are first mixed to obtain a mixed solution, and then a dispersant is added to the mixed solution. When titanium dioxide and solvent are mixed, ultrasonic oscillation is used for stirring, and the frequency of ultrasonic oscillation is 19.5kHz to 20.5kHz. When the dispersant is mixed with the mixed liquid, stir at a rotation speed of 2000rpm-2800rpm for 1h-1.5h, and then grind at a rotation speed of 2000rpm-2200rpm.

6. An ink, characterized in that: The invention relates to a color paste comprising the color paste described in any one of claims 1 to 3 or a color paste prepared by the method for preparing the color paste described in any one of claims 4 to 5.

7. The ink according to claim 6, characterized in that The mass fraction of the color paste in the ink is 15-35%; and / or, The ink further comprises a resin, a wetting agent, an organic solvent and a surfactant.

8. The ink according to claim 7, characterized in that The content of the resin in the ink is 8wt%-12wt%, the content of the wetting agent is 0.5wt%-3wt%, the content of the organic solvent is 56wt%-75wt%, and the content of the surfactant is 0.5wt%-1wt%; and / or, The boiling point of the organic solvent is less than or equal to 70°C; The organic solvent comprises a first solvent and a second solvent, the second solvent has a boiling point lower than the first solvent, and the mass ratio of the first solvent to the second solvent is (3-9):(2-5); and / or, The resin is at least one of a polyurethane resin and a modified polyurethane resin; and / or, The first solvent is a C2-C3 alcohol solvent, The second solvent is at least one of C1-C6 alkane or methanol.

9. Use of the color paste according to any one of claims 1 to 3, or the color paste prepared by the method for preparing the color paste according to any one of claims 4 to 5, or the ink according to any one of claims 6 to 8 in thermal foaming printing.

10. The use according to claim 9, characterized in that: The printed substrate is a non-porous substrate.

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