Preparation method of dispersing agent for ink jet

Abstract

The invention provides a preparation method of a dispersing agent for ink jet. The preparation method comprises the following steps: (1) preparing polyhydroxy acrylate; (2) preparing macromolecular polyurethane; and (3) mixing 20-25 parts by mass of polymer polyurethane, 10-15 parts by mass of polyhydroxy acrylate, 0.1-0.3 part by mass of dibutyltin dilaurate and 80-90 parts by mass of butyl acetate, stirring for 4-8 hours at the temperature of 90-110 DEG C, under the pressure of 0.1-0.5 MPa and under the protection of introduced nitrogen, cooling to 64-67 DEG C, adding 5-9 parts by mass of the modified nano material, continuously stirring and dissolving for 40-50 minutes, cooling and filtering to obtain the dispersing agent for ink jet. The groups in the dispersant can form an effective steric hindrance barrier, so that the environmental stability of the color paste can be improved. The dispersing agent disclosed by the invention can be used for preparing weak-solvent ink-jet color paste and is good in dispersity and stability.

Description

Technical Field

[0001] The invention belongs to the technical field of dispersants, and in particular relates to a method for preparing a dispersant for inkjet. Background Art

[0002] Inkjet dispersants play a vital role in inkjet inks. They are used to stabilize pigment particles, prevent them from aggregating or settling in the ink, and ensure that the ink can be evenly transported and sprayed during the printing process. Organic pigment color pastes are widely used and can be used in coatings, inks, inkjet inks, etc. However, there are always problems with unstable color pastes, easy stratification or floating color. The reason is that organic pigments are not easy to disperse stably in solvents, and the pigments are easy to precipitate and aggregate to cause sedimentation. Dispersants use the pigment affinity of the anchoring group to adsorb to the pigment surface, and then use the electrostatic repulsion or steric hindrance of the solubilized group to inhibit the attraction between pigment particles. However, current dispersants still cannot solve the problem of aggregation and sedimentation of organic pigments very well, and current dispersants are generally used in traditional solvent inks and have poor applicability to weak solvent inkjet color pastes.

[0003] Therefore, there is an urgent need for a dispersant suitable for weak solvent inkjet color paste. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a dispersant for inkjet.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: A method for preparing an inkjet dispersant, the method comprising the following steps: (1) Add 25-35 parts by weight of acrylic acid monomer and 2-4 parts by weight of initiator to 50-70 parts by weight of propylene glycol methyl ether acetate at a temperature of 120°C to 140°C and a pressure of 0.1MPa to 0.3MPa under nitrogen protection for 2-5 hours, keep the temperature for 2-4 hours, cool and filter to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 7-9 parts by weight of diol and 620-650 parts by weight of dimethylformamide are mixed, the temperature is raised to 72-75°C for reaction for 70-90 minutes, the temperature is lowered to 68-72°C, a dimethylformamide solution of dimethylol propionic acid is added dropwise, and after the addition is complete, dibutyltin dilaurate is added, the reaction is carried out for 90-100 minutes, and a hydrophilic carboxyl diol solution is continuously added dropwise for end-capping; the temperature is lowered to 50-55°C, a sodium carbonate solution with a concentration of 20-25wt% is slowly added dropwise, and water is added to adjust the solid content of the system to 30-35%, the temperature is raised to 65-70°C, and stirring and dissolving is continued for 40-50 minutes to obtain a high molecular weight polyurethane; (3) Mix 20-25 parts by weight of high molecular weight polyurethane, 10-15 parts by weight of polyhydroxy acrylate, 0.1-0.3 parts by weight of dibutyltin dilaurate and 80-90 parts by weight of butyl acetate, stir for 4 h to 8 h at a temperature of 90°C to 110°C, a pressure of 0.1 MPa to 0.5 MPa and nitrogen protection, cool to 64-67°C, add 5-9 parts by weight of modified nanomaterials, continue stirring and dissolving for 40-50 min, cool and filter to obtain a dispersant for inkjet.

[0006] Furthermore, the acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.3-1.6:1:0.2-0.5.

[0007] Furthermore, the initiator is di-tert-butyl peroxide.

[0008] Furthermore, the diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.2-1.5:0.6-0.8.

[0009] Furthermore, the diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.4-0.7:1.2-1.6.

[0010] Furthermore, in step (2), the dibutyltin dilaurate accounts for 0.15-0.25wt% of the total mass of the diisocyanate and the diol.

[0011] Furthermore, the concentration of the dimethylformamide solution of dimethylolpropionic acid is 25 wt % to 30 wt %.

[0012] Furthermore, the total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:13-18.

[0013] Furthermore, the reaction conditions of the end-capping are: end-capping, reaction time is 140-150min, and reaction temperature is 78-80°C.

[0014] Furthermore, the preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.3-1.7:0.4-0.8 to obtain a nano mixed powder; (2) Mixing nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 4-6:1:60-80:100, reacting at 50-55°C for 5-8h, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 2-4:13-15:100:0.5-1 are heated to 55-60°C for reaction for 20-25 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0015] Furthermore, the particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g.

[0016] Furthermore, the particle size of nano zirconium boride is 50-100nm and the specific surface area is 10-20m 2 / g.

[0017] Furthermore, the average particle size of nano-silicon carbide is 500nm and the specific surface area is 5-10m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0018] The invention also provides an inkjet dispersant prepared by the preparation method.

[0019] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: the groups in the dispersant of the present invention are synergistically compounded with the modified nanofiller to form an effective steric hindrance, which can improve the environmental stability of the color paste. The dispersant of the present invention can be used to prepare weak solvent inkjet color paste, which has good dispersibility and stability, will not settle after long-term storage, and the viscosity, particle size and surface tension of the ink meet the requirements of inkjet printing. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1 This embodiment provides a method for preparing an inkjet dispersant, the preparation method comprising the following steps: (1) At a temperature of 130° C., a pressure of 0.2 MPa and nitrogen protection, 30 parts by weight of acrylic acid monomer and 3 parts by weight of initiator were added dropwise to 60 parts by weight of propylene glycol methyl ether acetate for 4 hours, the mixture was kept warm for 3 hours, cooled and filtered to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 8 parts by weight of diol and 640 parts by weight of dimethylformamide were mixed, the temperature was raised to 74°C for reaction for 80 minutes, the temperature was lowered to 70°C, a dimethylformamide solution of dihydroxymethylpropionic acid was added dropwise, dibutyltin dilaurate was added after the addition was complete, the reaction was continued for 95 minutes, and a hydrophilic carboxyl diol solution was continued to be added dropwise for end-capping; the temperature was lowered to 52°C, a sodium carbonate solution with a concentration of 23wt% was slowly added dropwise, and water was added to adjust the solid content of the system to 33%, the temperature was raised to 67°C, and stirring and dissolving was continued for 45 minutes to obtain a high molecular weight polyurethane; (3) 23 parts by mass of high molecular weight polyurethane, 12 parts by mass of polyhydroxy acrylate, 0.2 parts by mass of dibutyltin dilaurate and 85 parts by mass of butyl acetate were mixed, stirred for 6 hours at a temperature of 100°C, a pressure of 0.3 MPa and nitrogen protection, cooled to 66°C, 7 parts by mass of modified nanomaterials were added, and stirring and dissolving was continued for 45 minutes. The mixture was cooled and filtered to obtain a dispersant for inkjet.

[0022] The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.5:1:0.4.

[0023] The initiator is di-tert-butyl peroxide.

[0024] The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.3:0.7.

[0025] The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.6:1.4.

[0026] In the step (2), dibutyltin dilaurate accounts for 0.2 wt% of the total mass of diisocyanate and diol.

[0027] The concentration of the dimethylformamide solution of dimethylolpropionic acid was 28 wt %.

[0028] The total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:15.

[0029] The reaction conditions for end-capping are: end-capping, reaction time is 145 min, and reaction temperature is 79°C.

[0030] The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.5:0.6 to obtain a nano mixed powder; (2) Mixing the nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 5:1:70:100, reacting at 52°C for 7 hours, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 3:14:100:0.7 were heated to 57°C for reaction for 22 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0031] The particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g.

[0032] The particle size of nano zirconium boride is 50-100nm and the specific surface area is 10-20m 2 / g.

[0033] The average particle size of nano-silicon carbide is 500nm and the specific surface area is 5-10m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0034] Comparative Example 1 The difference between this comparative example and Example 1 is that the acrylic acid monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1:1:1.

[0035] A method for preparing an inkjet dispersant, the method comprising the following steps: (1) At a temperature of 130° C., a pressure of 0.2 MPa and nitrogen protection, 30 parts by weight of acrylic acid monomer and 3 parts by weight of initiator were added dropwise to 60 parts by weight of propylene glycol methyl ether acetate for 4 hours, the mixture was kept warm for 3 hours, cooled and filtered to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 8 parts by weight of diol and 640 parts by weight of dimethylformamide were mixed, the temperature was raised to 74°C for reaction for 80 minutes, the temperature was lowered to 70°C, a dimethylformamide solution of dihydroxymethylpropionic acid was added dropwise, dibutyltin dilaurate was added after the addition was complete, the reaction was continued for 95 minutes, and a hydrophilic carboxyl diol solution was continued to be added dropwise for end-capping; the temperature was lowered to 52°C, a sodium carbonate solution with a concentration of 23wt% was slowly added dropwise, and water was added to adjust the solid content of the system to 33%, the temperature was raised to 67°C, and stirring and dissolving was continued for 45 minutes to obtain a high molecular weight polyurethane; (3) 23 parts by mass of high molecular weight polyurethane, 12 parts by mass of polyhydroxy acrylate, 0.2 parts by mass of dibutyltin dilaurate and 85 parts by mass of butyl acetate were mixed, stirred for 6 hours at a temperature of 100°C, a pressure of 0.3 MPa and nitrogen protection, cooled to 66°C, 7 parts by mass of modified nanomaterials were added, and stirring and dissolving was continued for 45 minutes. The mixture was cooled and filtered to obtain a dispersant for inkjet.

[0036] The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1:1:1.

[0037] The initiator is di-tert-butyl peroxide.

[0038] The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.3:0.7.

[0039] The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.6:1.4.

[0040] In the step (2), dibutyltin dilaurate accounts for 0.2 wt% of the total mass of diisocyanate and diol.

[0041] The concentration of the dimethylformamide solution of dimethylolpropionic acid was 28 wt %.

[0042] The total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:15.

[0043] The reaction conditions for end-capping are: end-capping, reaction time is 145 min, and reaction temperature is 79°C.

[0044] The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.5:0.6 to obtain a nano mixed powder; (2) Mixing the nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 5:1:70:100, reacting at 52°C for 7 hours, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 3:14:100:0.7 were heated to 57°C for reaction for 22 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0045] The particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g.

[0046] The particle size of nano zirconium boride is 50-100nm and the specific surface area is 10-20m 2 / g.

[0047] The average particle size of nano-silicon carbide is 500nm and the specific surface area is 5-10m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0048] Comparative Example 2 The difference between this comparative example and Example 1 is that the diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1:1.

[0049] A method for preparing an inkjet dispersant, the method comprising the following steps: (1) At a temperature of 130° C., a pressure of 0.2 MPa and nitrogen protection, 30 parts by weight of acrylic acid monomer and 3 parts by weight of initiator were added dropwise to 60 parts by weight of propylene glycol methyl ether acetate for 4 hours, the mixture was kept warm for 3 hours, cooled and filtered to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 8 parts by weight of diol and 640 parts by weight of dimethylformamide were mixed, the temperature was raised to 74°C for reaction for 80 minutes, the temperature was lowered to 70°C, a dimethylformamide solution of dihydroxymethylpropionic acid was added dropwise, dibutyltin dilaurate was added after the addition was complete, the reaction was continued for 95 minutes, and a hydrophilic carboxyl diol solution was continued to be added dropwise for end-capping; the temperature was lowered to 52°C, a sodium carbonate solution with a concentration of 23wt% was slowly added dropwise, and water was added to adjust the solid content of the system to 33%, the temperature was raised to 67°C, and stirring and dissolving was continued for 45 minutes to obtain a high molecular weight polyurethane; (3) 23 parts by mass of high molecular weight polyurethane, 12 parts by mass of polyhydroxy acrylate, 0.2 parts by mass of dibutyltin dilaurate and 85 parts by mass of butyl acetate were mixed, stirred for 6 hours at a temperature of 100°C, a pressure of 0.3 MPa and nitrogen protection, cooled to 66°C, 7 parts by mass of modified nanomaterials were added, and stirring and dissolving was continued for 45 minutes. The mixture was cooled and filtered to obtain a dispersant for inkjet.

[0050] The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.5:1:0.4.

[0051] The initiator is di-tert-butyl peroxide.

[0052] The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1:1.

[0053] The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.6:1.4.

[0054] In the step (2), dibutyltin dilaurate accounts for 0.2 wt% of the total mass of diisocyanate and diol.

[0055] The concentration of the dimethylformamide solution of dimethylolpropionic acid was 28 wt %.

[0056] The total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:15.

[0057] The reaction conditions for end-capping are: end-capping, reaction time is 145 min, and reaction temperature is 79°C.

[0058] The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.5:0.6 to obtain a nano mixed powder; (2) Mixing the nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 5:1:70:100, reacting at 52°C for 7 hours, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 3:14:100:0.7 were heated to 57°C for reaction for 22 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0059] The particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g.

[0060] The particle size of nano zirconium boride is 50-100nm and the specific surface area is 10-20m 2 / g.

[0061] The average particle size of nano-silicon carbide is 500nm and the specific surface area is 5-10m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0062] Comparative Example 3 The difference between this comparative example and Example 1 is that the diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:1:1.

[0063] A method for preparing an inkjet dispersant, the method comprising the following steps: (1) At a temperature of 130° C., a pressure of 0.2 MPa and nitrogen protection, 30 parts by weight of acrylic acid monomer and 3 parts by weight of initiator were added dropwise to 60 parts by weight of propylene glycol methyl ether acetate for 4 hours, the mixture was kept warm for 3 hours, cooled and filtered to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 8 parts by weight of diol and 640 parts by weight of dimethylformamide were mixed, the temperature was raised to 74°C for reaction for 80 minutes, the temperature was lowered to 70°C, a dimethylformamide solution of dihydroxymethylpropionic acid was added dropwise, dibutyltin dilaurate was added after the addition was complete, the reaction was continued for 95 minutes, and a hydrophilic carboxyl diol solution was continued to be added dropwise for end-capping; the temperature was lowered to 52°C, a sodium carbonate solution with a concentration of 23wt% was slowly added dropwise, and water was added to adjust the solid content of the system to 33%, the temperature was raised to 67°C, and stirring and dissolving was continued for 45 minutes to obtain a high molecular weight polyurethane; (3) 23 parts by mass of high molecular weight polyurethane, 12 parts by mass of polyhydroxy acrylate, 0.2 parts by mass of dibutyltin dilaurate and 85 parts by mass of butyl acetate were mixed, stirred for 6 hours at a temperature of 100°C, a pressure of 0.3 MPa and nitrogen protection, cooled to 66°C, 7 parts by mass of modified nanomaterials were added, and stirring and dissolving was continued for 45 minutes. The mixture was cooled and filtered to obtain a dispersant for inkjet.

[0064] The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.5:1:0.4.

[0065] The initiator is di-tert-butyl peroxide.

[0066] The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.3:0.7.

[0067] The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:1:1.

[0068] In the step (2), dibutyltin dilaurate accounts for 0.2 wt% of the total mass of diisocyanate and diol.

[0069] The concentration of the dimethylformamide solution of dimethylolpropionic acid was 28 wt %.

[0070] The total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:15.

[0071] The reaction conditions for end-capping are: end-capping, reaction time is 145 min, and reaction temperature is 79°C.

[0072] The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.5:0.6 to obtain a nano mixed powder; (2) Mixing the nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 5:1:70:100, reacting at 52°C for 7 hours, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 3:14:100:0.7 were heated to 57°C for reaction for 22 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0073] The particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g.

[0074] The particle size of nano zirconium boride is 50-100nm and the specific surface area is 10-20m 2 / g.

[0075] The average particle size of nano-silicon carbide is 500nm and the specific surface area is 5-10m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0076] Comparative Example 4 The difference between this comparative example and Example 1 is that the ratio of the mixed powder is different.

[0077] A method for preparing an inkjet dispersant, the method comprising the following steps: (1) At a temperature of 130° C., a pressure of 0.2 MPa and nitrogen protection, 30 parts by weight of acrylic acid monomer and 3 parts by weight of initiator were added dropwise to 60 parts by weight of propylene glycol methyl ether acetate for 4 hours, the mixture was kept warm for 3 hours, cooled and filtered to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 8 parts by weight of diol and 640 parts by weight of dimethylformamide were mixed, the temperature was raised to 74°C for reaction for 80 minutes, the temperature was lowered to 70°C, a dimethylformamide solution of dihydroxymethylpropionic acid was added dropwise, dibutyltin dilaurate was added after the addition was complete, the reaction was continued for 95 minutes, and a hydrophilic carboxyl diol solution was continued to be added dropwise for end-capping; the temperature was lowered to 52°C, a sodium carbonate solution with a concentration of 23wt% was slowly added dropwise, and water was added to adjust the solid content of the system to 33%, the temperature was raised to 67°C, and stirring and dissolving was continued for 45 minutes to obtain a high molecular weight polyurethane; (3) 23 parts by mass of high molecular weight polyurethane, 12 parts by mass of polyhydroxy acrylate, 0.2 parts by mass of dibutyltin dilaurate and 85 parts by mass of butyl acetate were mixed, stirred for 6 hours at a temperature of 100°C, a pressure of 0.3 MPa and nitrogen protection, cooled to 66°C, 7 parts by mass of modified nanomaterials were added, and stirring and dissolving was continued for 45 minutes. The mixture was cooled and filtered to obtain a dispersant for inkjet.

[0078] The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.5:1:0.4.

[0079] The initiator is di-tert-butyl peroxide.

[0080] The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.3:0.7.

[0081] The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.6:1.4.

[0082] In the step (2), dibutyltin dilaurate accounts for 0.2 wt% of the total mass of diisocyanate and diol.

[0083] The concentration of the dimethylformamide solution of dimethylolpropionic acid was 28 wt %.

[0084] The total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:15.

[0085] The reaction conditions for end-capping are: end-capping, reaction time is 145 min, and reaction temperature is 79°C.

[0086] The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1:1 to obtain a nano mixed powder; (2) Mixing the nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 5:1:70:100, reacting at 52°C for 7 hours, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 3:14:100:0.7 were heated to 57°C for reaction for 22 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0087] The particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g.

[0088] The particle size of nano zirconium boride is 50-100nm and the specific surface area is 10-20m 2 / g.

[0089] The average particle size of nano-silicon carbide is 500nm and the specific surface area is 5-10m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0090] Comparative Example 5 The difference between this comparative example and Example 1 is that the raw materials of the mixed powder are different.

[0091] A method for preparing an inkjet dispersant, the method comprising the following steps: (1) At a temperature of 130° C., a pressure of 0.2 MPa and nitrogen protection, 30 parts by weight of acrylic acid monomer and 3 parts by weight of initiator were added dropwise to 60 parts by weight of propylene glycol methyl ether acetate for 4 hours, the mixture was kept warm for 3 hours, cooled and filtered to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 8 parts by weight of diol and 640 parts by weight of dimethylformamide were mixed, the temperature was raised to 74°C for reaction for 80 minutes, the temperature was lowered to 70°C, a dimethylformamide solution of dihydroxymethylpropionic acid was added dropwise, dibutyltin dilaurate was added after the addition was complete, the reaction was continued for 95 minutes, and a hydrophilic carboxyl diol solution was continued to be added dropwise for end-capping; the temperature was lowered to 52°C, a sodium carbonate solution with a concentration of 23wt% was slowly added dropwise, and water was added to adjust the solid content of the system to 33%, the temperature was raised to 67°C, and stirring and dissolving was continued for 45 minutes to obtain a high molecular weight polyurethane; (3) 23 parts by mass of high molecular weight polyurethane, 12 parts by mass of polyhydroxy acrylate, 0.2 parts by mass of dibutyltin dilaurate and 85 parts by mass of butyl acetate were mixed, stirred for 6 hours at a temperature of 100°C, a pressure of 0.3 MPa and nitrogen protection, cooled to 66°C, 7 parts by mass of modified nanomaterials were added, and stirring and dissolving was continued for 45 minutes. The mixture was cooled and filtered to obtain a dispersant for inkjet.

[0092] The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.5:1:0.4.

[0093] The initiator is di-tert-butyl peroxide.

[0094] The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.3:0.7.

[0095] The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.6:1.4.

[0096] In the step (2), dibutyltin dilaurate accounts for 0.2 wt% of the total mass of diisocyanate and diol.

[0097] The concentration of the dimethylformamide solution of dimethylolpropionic acid was 28 wt %.

[0098] The total mass ratio of dimethylol propionic acid to diisocyanate and mixed diol is 1:15.

[0099] The reaction conditions for end-capping are: end-capping, reaction time is 145 min, and reaction temperature is 79°C.

[0100] The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.5:0.6 to obtain a nano mixed powder; (2) Mixing the nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 5:1:70:100, reacting at 52°C for 7 hours, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide (CAS No.: 32099-65-3) and triethylamine in a mass ratio of 3:14:100:0.7 were heated to 57°C for reaction for 22 hours, filtered, washed and dried to obtain a modified nanomaterial.

[0101] The particle size of nano zinc oxide is 100-500nm and the specific surface area is 5-10m 2 / g.

[0102] The particle size of nano zirconium boride is 400-500nm and the specific surface area is 2-8m 2 / g.

[0103] The average particle size of nano-silicon carbide is 800nm ​​and the specific surface area is 1-5m 2 / g. All were purchased from Zhejiang Zhiti Nano Micro New Materials Co., Ltd.

[0104] Performance Testing A weak solvent inkjet color paste comprises the following raw materials in parts by weight: 20 parts of a pigment, 15 parts of a dispersant prepared in Example 1 and Comparative Examples 1-5, and 50 parts of a weak solvent, dipropylene glycol monomethyl ether.

[0105] Environmental stability is measured by high temperature accelerated aging test. The test method is: place the color paste at 60℃ for 7 days to accelerate the aggregation of the pigments, and then test the viscosity, surface tension, particle size and filterability of the color paste. QC evaluation criteria: After aging, the particle size change is less than 10%, the surface tension change is less than 5%, the viscosity change is less than 10%, and the filterability is less than 3min / 1kg, which is qualified.

[0106] The viscosity test was performed using a Brookfield Wells cone-plate viscometer.

[0107] The surface tension test was conducted using a KYOWA CBVP surface tension meter.

[0108] The filterability test was conducted by using a 1.0 μm pore size PVDF filter membrane. The test results are shown in Table 1.

[0109] Table 1 Performance test results

[0110] It can be seen from the above performance test results that the performance of the dispersant of Example 1 is the most outstanding, while the comparative example is significantly worse than the embodiment in the corresponding performance test because it does not adopt the necessary technical scheme. The above experimental results further prove the importance of the technical scheme defined in the present invention to its technical effect.

[0111] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing an inkjet dispersant, characterized in that: The preparation method comprises the following steps: (1) Add 25-35 parts by weight of acrylic acid monomer and 2-4 parts by weight of initiator to 50-70 parts by weight of propylene glycol methyl ether acetate at a temperature of 120°C to 140°C and a pressure of 0.1MPa to 0.3MPa under nitrogen protection for 2-5 hours, keep the temperature for 2-4 hours, cool and filter to obtain polyhydroxy acrylate; (2) Under the protection of nitrogen, 10 parts by weight of diisocyanate, 7-9 parts by weight of diol and 620-650 parts by weight of dimethylformamide are mixed, the temperature is raised to 72-75°C for reaction for 70-90 minutes, the temperature is lowered to 68-72°C, a dimethylformamide solution of dihydroxymethylpropionic acid is added dropwise, dibutyltin dilaurate is added after the addition is complete, the reaction is carried out for 90-100 minutes, and a hydrophilic carboxyl diol solution is continuously added dropwise for end-capping; the temperature is lowered to 50-55°C, a sodium carbonate solution with a concentration of 20-25wt% is slowly added dropwise, and water is added to adjust the solid content of the system to 30-35%, the temperature is raised to 65-70°C, and stirring and dissolving is continued for 40-50 minutes to obtain a high molecular weight polyurethane; (3) Mix 20-25 parts by weight of high molecular weight polyurethane, 10-15 parts by weight of polyhydroxy acrylate, 0.1-0.3 parts by weight of dibutyltin dilaurate and 80-90 parts by weight of butyl acetate, stir for 4 h to 8 h at a temperature of 90°C to 110°C, a pressure of 0.1 MPa to 0.5 MPa and nitrogen protection, cool to 64-67°C, add 5-9 parts by weight of modified nanomaterials, continue stirring and dissolving for 40-50 min, cool and filter to obtain a dispersant for inkjet.

2. The method for preparing an inkjet dispersant according to claim 1, characterized in that: The acrylic monomer is a mixture of hydroxyethyl acrylate, methyl methacrylate and glycidyl methacrylate in a molar ratio of 1.3-1.6:1:0.2-0.

5.

3. The method for preparing an inkjet dispersant according to claim 1, characterized in that: The initiator is di-tert-butyl peroxide.

4. The method for preparing an inkjet dispersant according to claim 1, characterized in that: The diisocyanate is a mixture of hexamethylene diisocyanate, cyclohexane diisocyanate and dicyclohexylmethane diisocyanate in a mass ratio of 1:1.2-1.5:0.6-0.

8.

5. The method for preparing an inkjet dispersant according to claim 1, characterized in that: The diol is a mixture of sorbitol, pentanediol and bisphenol A in a mass ratio of 1:0.4-0.7:1.2-1.

6.

6. The method for preparing an inkjet dispersant according to claim 1, characterized in that: In the step (2), the dibutyltin dilaurate accounts for 0.15-0.25wt% of the total mass of the diisocyanate and the diol.

7. The method for preparing an inkjet dispersant according to claim 1, characterized in that: The concentration of the dimethylformamide solution of dimethylolpropionic acid is 25wt%-30wt%; the total mass ratio of dimethylolpropionic acid to diisocyanate and mixed diol is 1:13-18.

8. The method for preparing an inkjet dispersant according to claim 1, characterized in that: The preparation method of the modified nanomaterial is: (1) mixing nano zinc oxide, nano zirconium boride and nano silicon carbide in a mass ratio of 1:1.3-1.7:0.4-0.8 to obtain a nano mixed powder; (2) Mixing nano-mixed powder, silane coupling agent KH560, ethanol and water in a mass ratio of 4-6:1:60-80:100, reacting at 50-55°C for 5-8h, filtering and washing to obtain a silane-modified product; (3) The silane-modified product, N,N-dimethylformamide, N-(4-anilinophenyl)maleimide and triethylamine in a mass ratio of 2-4:13-15:100:0.5-1 are heated to 55-60°C for reaction for 20-25 hours, filtered, washed and dried to obtain a modified nanomaterial.

9. The method for preparing an inkjet dispersant according to claim 8, characterized in that: The particle size of nano zinc oxide is 30-50nm and the specific surface area is 15-30m 2 / g; the particle size of nano zirconium boride is 50-100nm, and the specific surface area is 10-20m 2 / g; the average particle size of nano-silicon carbide is 500nm, and the specific surface area is 5-10m 2 / g.

10. An inkjet dispersant prepared by the preparation method according to any one of claims 1 to 9.

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