A heat-sensitive transfer ink, its preparation and use

Abstract

The present application belongs to the technical field of ink, and particularly relates to a thermal transfer printing ink, a preparation method and application thereof. The present application uses modified ferroferric oxide composite material and carboxylated kaolin to obtain a mixed filler in combination with other components, and introduces silicon-containing phenolic resin into a polymer system, so as to effectively improve the tinting strength and adhesion of the ink, and ensure good initial dryness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ink, and particularly relates to a heat-sensitive transfer printing ink and a preparation method and application thereof. BACKGROUND

[0002] The heat transfer printing technology is a special technology based on the heat melting technology, and the basic principle is that resin particles in the heat transfer printing ink are subjected to heat melting effect under the action of a semiconductor electric heating head or laser heat conduction and pressure, so that image and text information is transferred to the surface of a printing material to form an image and text. The heat transfer printing ink is the most critical material in the heat transfer printing imaging technology. The heat transfer printing ink is coated on a base material in the form of a coating. When the base material is not subjected to heat, the heat transfer printing ink is stably fixed on the base material and does not cause any smearing phenomenon. When the base material is subjected to heat of the electric heating head or laser, pigment microcapsule particles in the heat transfer printing ink are immediately transferred to the printing material to form an image and text imprint during the heat melting process.

[0003] A heat transfer printing ink, a preparation method and application thereof are disclosed in Chinese Patent (Publication No. CN117924995A). The heat transfer printing ink uses the excellent solvent release and printing adaptability of a polymer, and is matched with different proportions of ester cellulose or ether cellulose and chlorovinyl resin. The three components cooperate with each other to achieve the printing adaptability, solvent release and post-processing performance of a benzene-containing and ketone-containing heat transfer printing ink without benzene and ketone. The benzene-free and ketone-free ink in the application can retain good fineness, viscosity and low solvent residue, and does not contain harmful ketone and benzene solvents, and is more environmentally friendly and safe. However, the patent does not solve the problems that the color strength and adhesion of the heat-sensitive transfer printing ink are low, and the initial dryness needs to be improved, which limits the application of the heat-sensitive transfer printing ink.

[0004] Therefore, there is an urgent need for a heat-sensitive transfer printing ink, which can effectively improve the color strength and adhesion of the ink by modifying the pigment component and matching with a suitable polymer material, and ensure good initial dryness. SUMMARY

[0005] The purpose of the application is to provide a heat-sensitive transfer printing ink, a preparation method and application thereof. The modified ferroferric oxide composite material and carboxylated kaolin are used to obtain a mixed filler by matching with other components, and a silicon-containing phenolic resin is introduced into the polymer system, so as to effectively improve the color strength and adhesion of the ink and ensure good initial dryness.

[0006] In order to achieve the above purpose, the application provides the following technical scheme:

[0007] The first aspect of the application provides a preparation method of a heat-sensitive transfer printing ink, which comprises the following steps:

[0008] Step S1: 120-140 parts of anhydrous ethanol and 30-40 parts of deionized water are mixed uniformly, then 1-3 parts of ferroferric oxide is ultrasonically dispersed for 40-60 min, 8-10 parts of tetraethyl orthosilicate and 4-6 parts of ammonia are added and stirred for 8-10 h, after the reaction is completed, washing, drying, to obtain a ferroferric oxide composite; 3-5 parts of the ferroferric oxide composite is added to 280-300 parts of deionized water and ultrasonically dispersed for 30-40 min, then 1-3 parts of 3-aminopropyltriethoxysilane is added, the pH is adjusted to 7.4-7.6, and stirring is carried out at 70-75℃ for 10-12 h, after the reaction is completed, centrifugation, washing, drying, to obtain a modified ferroferric oxide composite;

[0009] Step S2: 15-20 parts of chromium oxide, 15-20 parts of the modified ferroferric oxide composite, 5-10 parts of cobalt oxide and 5-10 parts of kaolin are mixed uniformly to obtain a pigment;

[0010] Step S3: 45-50 parts of epoxy resin, 8-10 parts of phenolic resin, 0.2-0.5 parts of dispersant and 0.2-0.5 parts of dimethyl silicone oil are added to 80-100 parts of solvent, stirring is carried out at 70-80℃ for 2-4 h, then the temperature is controlled at 40-50℃, 40-60 parts of the pigment is added and stirred uniformly to obtain a mixture, the mixture is transferred into a horizontal sand mill and ground for 4-6 h to obtain a thermal transfer printing ink.

[0011] The modified ferroferric oxide composite contains a mesoporous silica carrier and surface amino groups, which can endow the material with good thixotropy, help the ink to maintain good fluidity and printing suitability during printing, and at the same time, rapidly form a stable surface layer after printing, reduce the diffusion and sagging phenomenon, and effectively improve the ink coloring power.

[0012] As a preferred solution, the kaolin is carboxylated kaolin; a preparation method of the carboxylated kaolin comprises: 20-30 parts of alkenylated kaolin is dispersed in 250-300 parts of ethyl acetate, then 10-14 parts of itaconic acid and 1-3 parts of benzoyl peroxide are added, and reaction is carried out at 80-90℃ for 4-6 h, after the reaction is completed, cooling to room temperature, centrifugation, washing, vacuum drying, to obtain the carboxylated kaolin.

[0013] As a preferred solution, the preparation method of the alkenylized kaolin includes: adding 1-3 parts of sodium hydroxide into 250-300 parts of deionized water to stir and dissolve, then adding 20-30 parts of kaolin, stirring at 80-90℃ for 8-10h, centrifuging, washing, drying to obtain activated kaolin; mixing 10-20 parts of deionized water and 80-90 parts of anhydrous ethanol uniformly, adding 20-30 parts of the activated kaolin, adjusting the pH to 5.2-5.4 with 10% acetic acid solution, ultrasonic dispersion for 40-60min, then adding 5-7 parts of γ-(methacryloyloxy)propyl trimethoxysilane, reacting at 85-90℃ for 6-8h, cooling to room temperature after the reaction is completed, centrifuging, washing, drying to obtain the alkenylized kaolin.

[0014] As a preferred solution, the particle size of the kaolin is 60-90nm, and the specific surface area is 160-180m 2 / g.

[0015] The carboxylated kaolin can affect the evaporation of the solvent in the ink, make it quickly release on the surface while maintaining proper internal fluidity, thus promoting the rapid drying of the ink surface, optimizing the evaporation rate of the solvent through the carboxylated kaolin, and improving the initial dryness of the thermal transfer printing ink.

[0016] As a preferred solution, the epoxy resin is a bisphenol type epoxy resin and a naphthalene type epoxy resin; the mass ratio of the bisphenol type epoxy resin and the naphthalene type epoxy resin is (1-2):1.

[0017] As a preferred solution, the phenolic resin is a silicon-containing phenolic resin; the preparation method of the silicon-containing phenolic resin includes: mixing 6-8 parts of oxalic acid and 4-6 parts of sulfuric acid uniformly, then adding 100-110 parts of resorcinol to stir uniformly, adding 10-12 parts of formaldehyde at 90-95℃ for 50-60min; then adding 2-4 parts of sodium hydroxide and 4-6 parts of methyl trimethoxysilane at 100-110℃, stirring for 1-3h, cooling to room temperature after the reaction is completed to obtain the silicon-containing phenolic resin.

[0018] The silicon-containing phenolic resin can better wet the surface of the substrate by introducing siloxane groups to improve the interfacial compatibility, ensuring uniform spreading of the ink, reducing the generation of bubbles and voids, which helps to increase the contact area between the ink and the substrate and enhance the adhesion.

[0019] As a preferred solution, the dispersant is selected from any one or a combination of at least two of sodium hexametaphosphate, sodium tripolyphosphate, and sodium pyrophosphate.

[0020] As a preferred solution, the solvent is selected from any one or a combination of at least two of acetone, butanone, and cyclohexanone.

[0021] The second aspect of the present application provides a heat-sensitive transfer printing ink prepared by the preparation method of the first aspect.

[0022] The third aspect of the present application provides an application of the heat-sensitive transfer printing ink prepared by the preparation method of the first aspect in the field of printing.

[0023] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0024] 1、The modified ferroferric oxide composite material of the present application is loaded on a mesoporous silica carrier and introduces amino groups through surface treatment, and the kaolin introduces carboxyl groups through modification treatment, and the molecular chain segment of the silicon-containing phenolic resin has hydroxyl groups, and the above active groups can be combined with the epoxy groups of the epoxy resin, thereby forming an interpenetrating network structure, and the polymer can form a more firm interface bonding with the substrate surface through chemical interaction, thereby improving the ink adhesion; at the same time, through the high specific surface area of part of the materials, the uniform distribution of pigments is ensured, thereby improving the tinting strength and initial dryness.

[0025] 2、The modified ferroferric oxide composite material of the present application contains a mesoporous silica carrier and surface amino groups, which can endow the material with good thixotropy, which is helpful to maintain good fluidity and printing suitability of the ink during printing, and at the same time, a stable surface layer is quickly formed after printing, reducing the diffusion and sagging phenomenon, and effectively improving the ink tinting strength.

[0026] 3、The carboxylated kaolin of the present application can affect the volatilization of solvents in the ink, allowing it to be quickly released on the surface while maintaining proper fluidity inside, thereby promoting the rapid drying of the ink surface, and by optimizing the volatilization rate of the solvent through carboxylated kaolin, the initial dryness of the heat-sensitive transfer printing ink is improved.

[0027] 4、The silicon-containing phenolic resin of the present application improves the interfacial compatibility by introducing siloxane groups, thereby better wetting the substrate surface, ensuring uniform spreading of the ink, and reducing the generation of bubbles and voids, which helps to increase the contact area between the ink and the substrate and enhance the adhesion. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] Some components in the examples and comparative examples are as follows:

[0030] Chromium oxide, CAS No. 12182-82-0, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0031] Commercially available iron tetroxide, CAS number 1317-61-9, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0032] Cobalt oxide, CAS No. 1307-96-6, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0033] Commercially available kaolin I, product number TG-Y-3, has a particle size of 80 nm and a specific surface area of ​​180 m². 2 / g, purchased from Guangzhou Changyu Chemical Co., Ltd.;

[0034] Commercially available kaolin II, product number 1332-58-7, has a particle size of 300 nm and a specific surface area of ​​32 m². 2 / g, purchased from Shandong Zaozhuang Sanxing High-tech Materials Co., Ltd.;

[0035] Bisphenolic epoxy resin, model jER828EL, purchased from Mitsubishi Chemical Company;

[0036] Naphthalene-type epoxy resin, model ESN-475V, purchased from Nippon Steel Chemical Materials Co., Ltd.

[0037] Phenolic resin, model PF-8010, was purchased from Shandong Shengquan New Material Co., Ltd.

[0038] Sodium hexametaphosphate, CAS No. 10124-56-8, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0039] Sodium tripolyphosphate, CAS No. 7758-29-4, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0040] Sodium pyrophosphate, CAS No. 7722-88-5, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0041] Dimethyl silicone oil, CAS No. 9016-00-6, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0042] Tetraethyl silicate, CAS No. 78-10-4, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0043] 3-Aminopropyltriethoxysilane, CAS No. 919-30-2, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0044] γ-(methacryloyloxy)propyltrimethoxysilane, CAS No. 2530-85-0, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0045] Itaconic acid, CAS No. 97-65-4, purchased from Shanghai Macklin Biochemical Technology Co., Ltd.;

[0046] Benzoyl peroxide, CAS No. 94-36-0, purchased from Shanghai Macklin Biochemical Technology Co., Ltd.;

[0047] Resorcinol, CAS No. 108-46-3, purchased from National Pharmaceutical Group Chemical Reagent Co., Ltd.;

[0048] Formaldehyde, CAS No. 50-00-0, purchased from National Pharmaceutical Group Chemical Reagent Co., Ltd.;

[0049] Methyl trimethoxysilane, CAS No. 1185-55-3, purchased from National Pharmaceutical Group Chemical Reagent Co., Ltd.

[0050] Example 1

[0051] The present embodiment provides a preparation method of a heat-sensitive transfer ink, comprising the following steps:

[0052] Preparation of carboxylated kaolin: (1) 3 parts of sodium hydroxide were added to 300 parts of deionized water and stirred to dissolve, then 30 parts of kaolin I (particle size of 80 nm, specific surface area of 180 m 2 / g) was added, stirred at 90°C for 8h, centrifuged, washed, dried to obtain activated kaolin; 20 parts of deionized water and 90 parts of anhydrous ethanol were mixed uniformly, 30 parts of the activated kaolin was added, the pH was adjusted to 5.4 with 10% acetic acid solution, ultrasonic dispersion for 60 min, then 7 parts of γ-(methacryloyloxy) propyl trimethoxysilane was added, and the reaction was carried out at 90°C for 6h. After the reaction was completed, it was cooled to room temperature, centrifuged, washed, and dried to obtain alkenyl kaolin. (2) 30 parts of alkenyl kaolin was dispersed in 300 parts of ethyl acetate, then 14 parts of itaconic acid and 3 parts of benzoyl peroxide were added, and the reaction was carried out at 90°C for 4h. After the reaction was completed, it was cooled to room temperature, centrifuged, washed, and vacuum dried to obtain carboxylated kaolin.

[0053] Preparation of silicon-containing phenolic resin: 8 parts of oxalic acid and 6 parts of sulfuric acid were mixed uniformly, then 110 parts of resorcinol was added and stirred uniformly, 12 parts of formaldehyde was added at 95°C and kept for 50 min; then 4 parts of sodium hydroxide and 6 parts of methyl trimethoxysilane were added at 110°C and stirred for 1h. After the reaction was completed, it was cooled to room temperature to obtain silicon-containing phenolic resin.

[0054] Step S1: 140 parts of anhydrous ethanol and 40 parts of deionized water were mixed uniformly, then 3 parts of ferroferric oxide was ultrasonically dispersed for 60 min, 10 parts of tetraethyl silicate and 6 parts of ammonia were added and stirred for reaction for 10 h, after the reaction was completed, it was washed and dried to obtain a ferroferric oxide composite material; 5 parts of the ferroferric oxide composite material was added into 300 parts of deionized water and ultrasonically dispersed for 40 min, then 3 parts of 3-aminopropyl triethoxysilane was added, the pH was adjusted to 7.6, and it was stirred for reaction for 10 h at 75℃, after the reaction was completed, it was centrifuged, washed, and dried to obtain a modified ferroferric oxide composite material;

[0055] Step S2: 20 parts of chromium oxide, 20 parts of the modified ferroferric oxide composite material, 10 parts of cobalt oxide and 10 parts of carboxylated kaolin were mixed uniformly to obtain a pigment;

[0056] Step S3: 45 parts of epoxy resin (30 parts of bisphenol type epoxy resin and 15 parts of naphthalene type epoxy resin), 10 parts of silicon-containing phenolic resin, 0.5 parts of sodium hexametaphosphate and 0.5 parts of dimethyl silicone oil were added into 100 parts of acetone, stirred for 2 h at 80℃, then the temperature was controlled to 50℃, 60 parts of the pigment was added and stirred uniformly to obtain a mixture, the mixture was transferred into a horizontal sand mill and ground for 6 h to obtain a thermal transfer printing ink.

[0057] Example 2

[0058] The embodiment provides a preparation method of a thermal transfer printing ink, comprising the following steps:

[0059] The preparation method of the carboxylated kaolin comprises the following steps: (1) 1 part of sodium hydroxide was added into 250 parts of deionized water and stirred to dissolve, then 20 parts of kaolin I (particle size of 80 nm, specific surface area of 180 m 2 / g) was added, stirred for 10 h at 80℃, centrifuged, washed, and dried to obtain activated kaolin; 10 parts of deionized water and 80 parts of anhydrous ethanol were mixed uniformly, 20 parts of the activated kaolin was added, a 10% acetic acid solution was used to adjust the pH to 5.2, ultrasonically dispersed for 40 min, then 5 parts of γ-(methacryloyloxy) propyl trimethoxysilane was added, and reacted for 8 h at 85℃, after the reaction was completed, it was cooled to room temperature, centrifuged, washed, and dried to obtain alkenyl kaolin; (2) 20 parts of the alkenyl kaolin was dispersed in 250 parts of ethyl acetate, then 10 parts of itaconic acid and 1 part of benzoyl peroxide were added, and reacted for 6 h at 80℃, after the reaction was completed, it was cooled to room temperature, centrifuged, washed, and vacuum dried to obtain carboxylated kaolin.

[0060] The preparation method of the silicon-containing phenolic resin comprises the following steps: uniformly mixing 6 parts of oxalic acid and 4 parts of sulfuric acid, then adding 100 parts of resorcinol and stirring uniformly, adding 12 parts of formaldehyde at 90℃ and keeping for 60 min; then adding 2 parts of sodium hydroxide and 4 parts of methyltrimethoxysilane at 100℃ and stirring for 3 h, and cooling to room temperature after the reaction is completed to obtain the silicon-containing phenolic resin.

[0061] Step S1: uniformly mix 120 parts of anhydrous ethanol and 30 parts of deionized water, then ultrasonically disperse 1 part of ferroferric oxide for 40 min, then add 8 parts of tetraethyl silicate and 4 parts of ammonia water and stir for 8 h, wash and dry after the reaction is completed to obtain a ferroferric oxide composite; ultrasonically disperse 3 parts of the ferroferric oxide composite in 280 parts of deionized water for 30 min, then add 1 part of 3-aminopropyl triethoxysilane, adjust the pH to 7.4, and stir at 70℃ for 12 h, and centrifuge, wash and dry after the reaction is completed to obtain a modified ferroferric oxide composite;

[0062] Step S2: uniformly mix 15 parts of chromium oxide, 15 parts of the modified ferroferric oxide composite, 5 parts of cobalt oxide and 5 parts of carboxylated kaolin to obtain a pigment;

[0063] Step S3: add 50 parts of epoxy resin (25 parts of bisphenol type epoxy resin and 25 parts of naphthalene type epoxy resin), 8 parts of the silicon-containing phenolic resin, 0.2 parts of sodium tripolyphosphate and 0.2 parts of dimethyl silicone oil into 80-100 parts of methyl ethyl ketone, stir at 70℃ for 4 h, then control the temperature to be 40℃, add 40 parts of the pigment and stir uniformly to obtain a mixture, and transfer the mixture into a horizontal sand mill and grind for 4 h to obtain a thermal transfer printing ink.

[0064] Example 3

[0065] The embodiment provides a preparation method of a thermal transfer printing ink, comprising the following steps:

[0066] The preparation method of the carboxylated kaolin comprises the following steps: (1) uniformly mix 2 parts of sodium hydroxide into 280 parts of deionized water and stir to dissolve, then add 25 parts of kaolin I (with a particle size of 80 nm and a specific surface area of 180 m 2 / g), stirring at 85℃ for 9h, centrifugation, washing, drying to obtain activated kaolin; 15 parts of deionized water and 85 parts of anhydrous ethanol were mixed uniformly, 25 parts of the activated kaolin was added, the pH was adjusted to 5.3 with 10% acetic acid solution, ultrasonic dispersion was performed for 50 min, then 6 parts of γ-(methacryloyloxy) propyl trimethoxysilane was added, and reaction was performed at 88℃ for 7h. After the reaction was completed, it was cooled to room temperature, centrifuged, washed, and dried to obtain alkenyl kaolin. (2) 25 parts of alkenyl kaolin was dispersed in 280 parts of ethyl acetate, then 12 parts of itaconic acid and 2 parts of benzoyl peroxide were added, and reaction was performed at 85℃ for 5h. After the reaction was completed, it was cooled to room temperature, centrifuged, washed, and vacuum dried to obtain carboxylated kaolin.

[0067] The preparation method of the silicon-containing phenolic resin comprises the following steps: 7 parts of oxalic acid and 4-6 parts of sulfuric acid are uniformly mixed, then 105 parts of resorcinol is uniformly stirred, 11 parts of formaldehyde is added at 92℃ and kept for 55 min; then 3 parts of sodium hydroxide and 5 parts of methyl trimethoxysilane are added at 105℃, and stirring reaction is performed for 2h. After the reaction is completed, it is cooled to room temperature to obtain the silicon-containing phenolic resin.

[0068] Step S1: 130 parts of anhydrous ethanol and 35 parts of deionized water are uniformly mixed, then 2 parts of ferroferric oxide is ultrasonically dispersed for 50 min, 9 parts of tetraethyl orthosilicate and 5 parts of ammonia water are added and stirring reaction is performed for 9h. After the reaction is completed, it is washed and dried to obtain a ferroferric oxide composite material; 4 parts of the ferroferric oxide composite material is added to 290 parts of deionized water and ultrasonically dispersed for 35 min, then 2 parts of 3-aminopropyl triethoxysilane is added, the pH is adjusted to 7.5, and stirring reaction is performed at 72℃ for 11h. After the reaction is completed, it is centrifuged, washed, and dried to obtain a modified ferroferric oxide composite material.

[0069] Step S2: 18 parts of chromium oxide, 17 parts of the modified ferroferric oxide composite material, 8 parts of cobalt oxide, and 7 parts of carboxylated kaolin are uniformly mixed to obtain a pigment.

[0070] Step S3: 48 parts of epoxy resin (30 parts of bisphenol type epoxy resin and 18 parts of naphthalene type epoxy resin), 9 parts of silicon-containing phenolic resin, 0.4 parts of sodium pyrophosphate, and 0.4 parts of dimethyl silicone oil are added to 90 parts of cyclohexanone, stirring is performed at 75℃ for 3h, then the temperature is controlled at 45℃, 50 parts of the pigment is added and uniformly stirred to obtain a mixture, and the mixture is transferred into a horizontal sand mill and ground for 5h to obtain a thermal transfer printing ink.

[0071] Comparative Example 1

[0072] The difference between the present comparative example and Example 1 is that commercially available ferroferric oxide is used instead of the modified ferroferric oxide composite.

[0073] Comparative Example 2

[0074] The difference between the present comparative example and Example 1 is that commercially available kaolin is used instead of carboxylated kaolin.

[0075] Comparative Example 3

[0076] The difference between the present comparative example and Example 1 is that commercially available kaolin II is used instead of commercially available kaolin I in preparation.

[0077] Comparative Example 4

[0078] The difference between the present comparative example and Example 1 is that commercially available phenolic resin is used instead of silicon-containing phenolic resin.

[0079] Comparative Example 5

[0080] The difference between the present comparative example and Example 1 is that the amount of bisphenol-type epoxy resin is changed to 35 parts and the amount of naphthalene-type epoxy resin is changed to 10 parts.

[0081] Comparative Example 6

[0082] The difference between the present comparative example and Example 1 is that the amount of bisphenol-type epoxy resin is changed to 15 parts and the amount of naphthalene-type epoxy resin is changed to 30 parts.

[0083] Performance test

[0084] The thermal sensitive transfer ink prepared in the above examples and comparative examples is subjected to the following tests:

[0085] (1) Color strength test

[0086] The color strength is tested according to the requirements of GB / T 13217.1-2020 Ink Color and Color Strength Test Method.

[0087] (2) Initial dryness test

[0088] The initial dryness is tested according to the requirements of GB / T 13217.5-2023 Ink Drying Test Method.

[0089] (3) Adhesion test

[0090] The adhesion is tested according to the requirements of GB / T 13217.7-2023 Ink Adhesion Test Method.

[0091] Table 1 Performance test results

[0092]

[0093] From the performance test results, it can be seen that the thermal transfer printing ink of Examples 1-3 has the best comprehensive effect, the tinting strength is 98.9-99.4%, the initial dryness is 32-34s, and the adhesion is 93.1-93.7%, which is mainly because the modified ferroferric oxide composite material and carboxylated kaolin are used to obtain a mixed filler with other components, and the silicon-containing phenolic resin is introduced into the polymer system, which effectively improves the tinting strength and adhesion of the ink and ensures good initial dryness.

[0094] Compared with Example 1, the tinting strength, initial dryness and adhesion of the thermal transfer printing ink of Comparative Example 1 are all reduced because the commercially available ferroferric oxide is used instead of the modified ferroferric oxide composite material. Compared with Example 1, the tinting strength, initial dryness and adhesion of the thermal transfer printing ink of Comparative Example 2 are all reduced because the commercially available kaolin is used instead of the carboxylated kaolin. Compared with Example 1, the tinting strength, initial dryness and adhesion of the thermal transfer printing ink of Comparative Example 3 are all reduced because the commercially available kaolin II is used instead of the commercially available kaolin I, and the particle size of the commercially available kaolin II is too large and the specific surface area is too small, resulting in poor modification effect. Compared with Example 1, the tinting strength, initial dryness and adhesion of the thermal transfer printing ink of Comparative Example 4 are all reduced because the commercially available phenolic resin is used instead of the silicon-containing phenolic resin. Compared with Example 1, the tinting strength, initial dryness and adhesion of the thermal transfer printing ink of Comparative Example 5 are all reduced because the amount of the bisphenol-type epoxy resin is changed to 35 parts and the amount of the naphthalene-type epoxy resin is changed to 10 parts, and the amount of the bisphenol-type epoxy resin is too large, resulting in poor compounding effect. Compared with Example 1, the tinting strength, initial dryness and adhesion of the thermal transfer printing ink of Comparative Example 6 are all reduced because the amount of the bisphenol-type epoxy resin is changed to 15 parts and the amount of the naphthalene-type epoxy resin is changed to 30 parts, and the amount of the naphthalene-type epoxy resin is too large, resulting in poor compounding effect. The above experimental results further prove the importance of the limited technical solutions in the present application to the technical effects.

[0095] The above is a preferred embodiment of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A method of preparing a heat-sensitive transfer ink, characterized in that, Comprising the following steps: Step S1: 120~140 parts of anhydrous ethanol and 30~40 parts of deionized water are mixed uniformly, then 1~3 parts of ferroferric oxide is ultrasonically dispersed for 40~60 min, 8~10 parts of tetraethyl silicate and 4~6 parts of ammonia are added and stirred for 8~10 h, after the reaction is completed, it is washed, dried, and ferroferric oxide composite material is obtained; 3~5 parts of the ferroferric oxide composite material is added to 280~300 parts of deionized water and ultrasonically dispersed for 30~40 min, then 1~3 parts of 3-aminopropyl triethoxysilane is added, the pH is adjusted to 7.4~7.6, and stirring is carried out at 70~75℃ for 10~12 h, after the reaction is completed, centrifugation, washing, and drying are carried out, and modified ferroferric oxide composite material is obtained; Step S2: 15~20 parts of chromium oxide, 15~20 parts of modified ferroferric oxide composite material, 5~10 parts of cobalt oxide, and 5~10 parts of kaolin are mixed uniformly to obtain a pigment; Step S3: 45~50 parts of epoxy resin, 8~10 parts of phenolic resin, 0.2~0.5 parts of dispersant, and 0.2~0.5 parts of dimethyl silicone oil are added to 80~100 parts of solvent, stirring is carried out at 70~80℃ for 2~4 h, then the temperature is controlled at 40~50℃, 40~60 parts of the pigment is added and stirred uniformly to obtain a mixture, the mixture is transferred into a horizontal sand mill and ground for 4~6 h to obtain a heat-sensitive transfer ink; The kaolin is carboxylated kaolin, and the preparation method comprises the following steps: 20~30 parts of alkenylated kaolin is dispersed in 250~300 parts of ethyl acetate, then 10~14 parts of itaconic acid and 1~3 parts of benzoyl peroxide are added, and reaction is carried out at 80~90℃ for 4~6 h, after the reaction is completed, it is cooled to room temperature, centrifuged, washed, and vacuum dried to obtain carboxylated kaolin; The epoxy resin is bisphenol type epoxy resin and naphthalene type epoxy resin, and the mass ratio is (1~2):1; The phenolic resin is a silicon-containing phenolic resin, and the preparation method comprises the following steps: 6~8 parts of oxalic acid and 4~6 parts of sulfuric acid are mixed uniformly, then 100~110 parts of resorcinol is added and stirred uniformly, 10~12 parts of formaldehyde is added at 90~95℃ and kept for 50~60 min; then 2~4 parts of sodium hydroxide and 4~6 parts of methyltrimethoxysilane are added at 100~110℃, and stirring is carried out for 1~3 h, after the reaction is completed, it is cooled to room temperature, and the silicon-containing phenolic resin is obtained.

2. The method of preparing a thermal transfer ink according to claim 1, characterized in that, The preparation method of the alkenylized kaolin clay comprises: adding 1-3 parts of sodium hydroxide into 250-300 parts of deionized water by weight and stirring to dissolve, then adding 20-30 parts of kaolin clay, stirring at 80-90℃ for 8-10h, centrifuging, washing, drying to obtain activated kaolin clay; mixing 10-20 parts of deionized water and 80-90 parts of anhydrous ethanol uniformly, adding 20-30 parts of the activated kaolin clay, adjusting the pH to 5.2-5.4 with a 10% acetic acid solution by mass fraction, ultrasonic dispersing for 40-60min, then adding 5-7 parts of γ-(methacryloyloxy)propyl trimethoxysilane, reacting at 85-90℃ for 6-8h, cooling to room temperature after the reaction is completed, centrifuging, washing, drying to obtain the alkenylized kaolin clay.

3. The method of preparing a thermal transfer ink according to claim 2, wherein The particle size of the kaolin is 60-90 nm, and the specific surface area is 160-180 m 2 / g.

4. The method of claim 1, wherein the heat sensitive transfer ink is prepared by the steps of: The dispersant is selected from any one or a combination of at least two of sodium hexametaphosphate, sodium tripolyphosphate and sodium pyrophosphate.

5. The method of claim 1, wherein the heat sensitive transfer ink is prepared by the steps of: The solvent is selected from any one or a combination of at least two of acetone, butanone and cyclohexanone.

6. A heat sensitive transfer ink characterized in that, Prepared according to the method of any one of claims 1-5.

7. Use of a heat-sensitive transfer ink prepared according to the method of any one of claims 1-5 in the field of printing.

Images