Preparation method of piperazinyl reflective ink

Abstract

The invention relates to a preparation method of piperazinyl reflective ink, and relates to the technical field of ink preparation. The preparation method comprises the following steps: adding a resin binder, a dispersant and a solvent into a stirring container, and stirring to form a uniform mixed solution; adding the pigment and the reflective micro-beads into the mixed solution, and continuously stirring, so that the pigment and the reflective micro-beads are preliminarily dispersed in the mixed solution; transferring the mixture into a grinding machine for grinding, so that the pigment and the reflective microspheres are further refined and uniformly dispersed in a mixed system; adding a flatting agent, a polydimethylsiloxane defoaming agent and a solvent into the ground material, stirring, and sufficiently and uniformly mixing the components to obtain the reflective ink. The reflective ink prepared by the invention has a relatively high retroreflection coefficient and a good reflective effect.

Description

Technical Field

[0001] The invention relates to the technical field of ink preparation, in particular to a method for preparing piperazine-based reflective ink. Background Art

[0002] Reflective ink, a special type of ink that reflects bright light when exposed to sunlight, is widely used in traffic signs, advertising billboards, safety protection, and other fields. Currently, existing reflective inks on the market suffer from unstable reflective effects and poor adhesion to printed substrates. This is primarily due to inadequate raw material formulations and manufacturing processes. Some reflective inks contain uneven dispersion of the reflective material, resulting in inconsistent reflective effects. Furthermore, the binder in the ink does not bond tightly to the reflective material and pigment, affecting the ink's adhesion to the printed substrate and limiting its application and effectiveness. Therefore, there is an urgent need to develop a new method for preparing reflective inks to address these issues. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a method for preparing a piperazine-based reflective ink, the operating steps of which are as follows:

[0004] S1 Pre-dispersion: Add 30-50 parts of resin binder, 1-5 parts of dispersant, and 10-20 parts of solvent into a stirring container, and stir at a speed of 300-500 rpm for 10-20 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0005] S2: Add pigment and reflective microbeads: Add 5-15 parts of pigment and 20-35 parts of reflective microbeads to the mixed solution, increase the stirring speed to 800-1200 rpm, and stir for 20-30 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0006] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 10-20 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0007] S4 post-treatment: add 0.5-3 parts of leveling agent, 0.5-3 parts of polydimethylsiloxane defoaming agent, and 10-20 parts of solvent to the ground material, stir at a speed of 300-500 rpm for 10-15 minutes to fully mix the components to obtain reflective ink.

[0008] As a preferred embodiment of the present invention, the resin binder is acrylic resin or polyurethane resin.

[0009] As a preferred embodiment of the present invention, the dispersant is one of sodium polyacrylate, ammonium polyacrylate and sodium polymethacrylate.

[0010] As a preferred embodiment of the present invention, the solvent is one of ethyl acetate, butanone and toluene.

[0011] As a preferred embodiment of the present invention, the reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, and the particle size thereof is 10-50 microns.

[0012] As a preferred embodiment of the present invention, the leveling agent is one of a polyethylene glycol type polyether modified silicone leveling agent, a polypropylene glycol type polyether modified silicone leveling agent, and a polyethylene glycol-polypropylene glycol block type polyether modified silicone leveling agent.

[0013] As a preferred embodiment of the present invention, the preparation method of the piperazinylsilane-metal coordinated polyurethane modified glass microspheres is:

[0014] T1 piperazine silane grafting:

[0015] Add 20-35 parts of glass microspheres to a three-necked flask equipped with a condenser, a thermometer, and a stirrer, add 200-300 parts of anhydrous toluene, start the stirrer, and stir at a speed of 200-300 rpm. Add 1-3 parts of 3-piperazinepropyltrimethoxysilane with a purity of ≥97%; raise the temperature of the reaction system to 80-100° C. using a heating mantle, and reflux and stir for 2-5 hours; filter and separate the glass microspheres, and then vacuum dry to constant weight to obtain piperazine-modified glass microspheres;

[0016] T2 metal coordination crosslinking:

[0017] Add 20-40 parts of polyester polyol with acid value ≤ 5mgKOH / g into a reaction kettle equipped with a stirrer and a thermometer, add analytically pure zinc acetate according to 2-5% of the mass of the polyester polyol; turn on the stirrer and react at 100-120℃ for 2-4 hours to obtain Zn-containing 2+ Hydroxyl terminated polyester;

[0018] T3: piperazine-modified glass microspheres containing Zn 2+ The hydroxyl-terminated polyester and 8-hydroxyquinoline nickel are added into the reactor in a mass ratio of 1:0.6-0.8:0.03-0.3, stirred at a speed of 150-200 rpm, and reacted at 60-70°C for 2-4 hours. After the reaction, the modified glass microbeads are separated by filtration, washed with ethanol multiple times, and dried in vacuum to constant weight to obtain piperazine silane-metal coordinated polyurethane modified glass microbeads.

[0019] Reaction mechanism

[0020] Various coordination and interactions: The nitrogen atom in the piperazine group on the surface of piperazine-modified glass microspheres has a lone pair of electrons and can interact with Zn-containing 2+Zn in hydroxyl-terminated polyester 2+ The nickel ions in 8-hydroxyquinoline nickel can also coordinate with piperazine groups and certain groups in the polyester, further enhancing the crosslinking of the system. Furthermore, hydrogen bonds between the hydroxyl groups on the polyester molecular chain and the silanol groups remaining on the surface of the glass microbeads enhance the binding force between the glass microbeads and the polyester, making the entire system more stable.

[0021] Technical Effects

[0022] The present invention provides a method for preparing a piperazine-based reflective ink. Compared with the prior art, the present invention has the following significant effects:

[0023] 1. Good dispersibility: Through a specific preparation process and the selection of suitable dispersants, the pigments and reflective microbeads are evenly dispersed in the ink, which improves the stability and consistency of the reflective effect.

[0024] 2. Good leveling and defoaming properties: The added leveling agent and defoaming agent effectively improve the leveling and defoaming properties of the ink and improve the printing quality.

[0025] 3. Improved Dispersion: The surface properties of the glass microspheres modified by piperazine silane grafting and metal coordination crosslinking have been altered, significantly enhancing their compatibility with the resin binder. This allows the reflective microspheres to be more evenly dispersed in the ink system, preventing microbead agglomeration and thus improving the overall dispersion stability of the reflective ink. During the printing process, the evenly dispersed reflective microspheres can more effectively reflect light, ensuring the consistency and stability of the reflective effect.

[0026] 4. Enhanced mechanical properties: The stable structure formed by metal coordination cross-linking enhances the bonding force between glass beads and polyester, making the reflective ink have better mechanical properties after curing.

[0027] 5. Improve weather resistance: 8-Hydroxyquinoline nickel has certain light stability and antioxidant properties. Its introduction can improve the weather resistance of reflective ink. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention object, the following is a detailed description in conjunction with examples and comparative examples:

[0029] The retroreflection coefficient tester (model: SMD-2001, Tianjin Jinanrui Instrument Co., Ltd.) was used to measure the retroreflection coefficient of the reflective ink layer at different angles.

[0030] Example 1

[0031] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0032] S1 Pre-dispersion: Add 30g of resin binder, 1g of dispersant, and 10g of solvent into a stirring container and stir at 300 rpm for 10 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0033] S2: Add pigment and reflective microbeads: Add 5g of pigment and 20g of reflective microbeads to the mixed solution, increase the stirring speed to 800 rpm, and stir for 20 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0034] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 20 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0035] S4 post-treatment: 0.5 g of leveling agent, 0.5 g of Dow Corning AFE-1410 polydimethylsiloxane defoaming agent, and 10 g of solvent were added to the ground material, and stirred at a speed of 300 rpm for 10 minutes to fully mix the components to obtain reflective ink.

[0036] The resin connecting material is Hanwha S90 acrylic resin.

[0037] The dispersant is SP-02 sodium polyacrylate.

[0038] The solvent is ethyl acetate.

[0039] The reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, and the particle size is 50 microns.

[0040] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0041] The preparation method of the piperazinylsilane-metal coordinated polyurethane modified glass microspheres is as follows:

[0042] T1 piperazine silane grafting:

[0043] 20 g of glass microspheres were added to a three-necked flask equipped with a condenser, a thermometer, and a stirrer. 200 g of anhydrous toluene was added, and the stirrer was turned on and stirred at 200 rpm. 1 g of 3-piperazinepropyltrimethoxysilane (CAS: 40762-28-5) with a purity of ≥97% was added. The reaction system temperature was raised to 80° C. using a heating mantle, and the reaction was refluxed and stirred for 2 hours. The glass microspheres were separated by filtration and then vacuum dried to constant weight to obtain piperazine-modified glass microspheres.

[0044] T2 metal coordination crosslinking:

[0045] Add 20g of polyester polyol with acid value ≤5mgKOH / g into a reactor equipped with a stirrer and a thermometer, add analytically pure zinc acetate according to 2% of the mass of the polyester polyol; turn on the stirrer and react at 100℃ for 2 hours to obtain Zn-containing 2+ Hydroxyl terminated polyester;

[0046] T3: piperazine-modified glass microspheres containing Zn 2+ The hydroxyl-terminated polyester and 8-hydroxyquinoline nickel were added into the reactor in a mass ratio of 1:0.6:0.03, stirred at a speed of 150 rpm, and reacted at 60°C for 2 hours. After the reaction, the modified glass microbeads were separated by filtration, washed with ethanol several times, and dried in vacuum to constant weight to obtain piperazine silane-metal coordinated polyurethane modified glass microbeads.

[0047] Example 2

[0048] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0049] S1 Pre-dispersion: Add 35g of resin binder, 2g of dispersant, and 13g of solvent into a stirring container and stir at 350 rpm for 15 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0050] S2: Add pigment and reflective microbeads: Add 8 g of pigment and 25 g of reflective microbeads to the mixture, increase the stirring speed to 900 rpm, and stir for 25 minutes to initially disperse the pigment and reflective microbeads in the mixture;

[0051] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 15 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0052] S4 post-treatment: 1 g of leveling agent, 1 g of Dow Corning AFE-1410 polydimethylsiloxane defoamer, and 14 g of solvent were added to the ground material, and stirred at a speed of 350 rpm for 10 minutes to fully mix the components to obtain reflective ink.

[0053] The resin connecting material is Hanwha S90 acrylic resin.

[0054] The dispersant is Weifang Luyi ammonium polyacrylate 5020.

[0055] The solvent is butanone.

[0056] The reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, and the particle size is 40 microns.

[0057] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0058] The preparation method of the piperazinylsilane-metal coordinated polyurethane modified glass microspheres is as follows:

[0059] T1 piperazine silane grafting:

[0060] 25 g of glass microspheres were added to a three-necked flask equipped with a condenser, a thermometer, and a stirrer. 240 g of anhydrous toluene was added, and the stirrer was turned on and stirred at 250 rpm. 2 g of 3-piperazinepropyltrimethoxysilane (CAS: 40762-28-5) with a purity of ≥97% was added. The reaction system temperature was raised to 85° C. using a heating mantle, and the reaction was refluxed and stirred for 3 hours. The glass microspheres were separated by filtration and then vacuum dried to constant weight to obtain piperazine-modified glass microspheres.

[0061] T2 metal coordination crosslinking:

[0062] Add 25g of polyester polyol with acid value ≤5mgKOH / g into a reactor equipped with a stirrer and a thermometer, add analytically pure zinc acetate according to 3% of the mass of the polyester polyol; turn on the stirrer and react at 105℃ for 3 hours to obtain Zn-containing 2+ Hydroxyl terminated polyester;

[0063] T3: piperazine-modified glass microspheres containing Zn 2+ The hydroxyl-terminated polyester and 8-hydroxyquinoline nickel were added into the reactor in a mass ratio of 1:0.7:0.1, stirred at a speed of 160 rpm, and reacted at 65°C for 3 hours. After the reaction, the modified glass microbeads were separated by filtration, washed with ethanol several times, and dried in vacuum to constant weight to obtain piperazine silane-metal coordinated polyurethane modified glass microbeads.

[0064] Example 3

[0065] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0066] S1 Pre-dispersion: Add 45g of resin binder, 4g of dispersant, and 18g of solvent into a stirring container and stir at 450 rpm for 15 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0067] S2 Add pigment and reflective microbeads: Add 13g of pigment and 30g of reflective microbeads to the mixed solution, increase the stirring speed to 1100 rpm, and stir for 25 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0068] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 15 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0069] S4 post-treatment: 2 g of leveling agent, 2 g of Dow Corning AFE-1410 polydimethylsiloxane defoaming agent, and 18 g of solvent were added to the ground material, and stirred at a speed of 450 rpm for 15 minutes to fully mix the components to obtain reflective ink.

[0070] The resin connecting material is PU548 polyurethane resin.

[0071] The dispersant is Weifang Luyi ammonium polyacrylate 5020.

[0072] The solvent is butanone.

[0073] The reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, and the particle size is 20 microns.

[0074] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0075] The preparation method of the piperazinylsilane-metal coordinated polyurethane modified glass microspheres is as follows:

[0076] T1 piperazine silane grafting:

[0077] 30 g of glass microspheres were added to a three-necked flask equipped with a condenser, a thermometer, and a stirrer. 280 g of anhydrous toluene was added, and the stirrer was turned on and stirred at 250 rpm. 2 g of 3-piperazinepropyltrimethoxysilane (CAS: 40762-28-5) with a purity of ≥97% was added. The reaction system temperature was raised to 95° C. using a heating mantle, and the reaction was refluxed and stirred for 4 hours. The glass microspheres were separated by filtration and then vacuum dried to constant weight to obtain piperazine-modified glass microspheres.

[0078] T2 metal coordination crosslinking:

[0079] In a reaction kettle equipped with a stirrer and a thermometer, 35 g of polyester polyol with an acid value of ≤5 mgKOH / g was added, and analytically pure zinc acetate was added according to 4% of the mass of the polyester polyol; the stirrer was turned on and the reaction was carried out at 115 ° C for 3 hours to obtain a Zn-containing 2+ Hydroxyl terminated polyester;

[0080] T3: piperazine-modified glass microspheres containing Zn 2+The hydroxyl-terminated polyester and 8-hydroxyquinoline nickel were added into the reactor in a mass ratio of 1:0.7:0.2, stirred at a speed of 180 rpm, and reacted at 65°C for 3 hours. After the reaction, the modified glass microbeads were separated by filtration, washed with ethanol several times, and dried in vacuum to constant weight to obtain piperazine silane-metal coordinated polyurethane modified glass microbeads.

[0081] Example 4

[0082] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0083] S1 Pre-dispersion: Add 50g of resin binder, 5g of dispersant, and 20g of solvent into a stirring container and stir at 500 rpm for 20 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0084] S2: Add pigment and reflective microbeads: Add 15g of pigment and 35g of reflective microbeads to the mixed solution, increase the stirring speed to 1200 rpm, and stir for 30 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0085] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 10 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0086] S4 post-treatment: 3 g of leveling agent, 3 g of Dow Corning AFE-1410 polydimethylsiloxane defoaming agent, and 20 g of solvent were added to the ground material, and stirred at a speed of 500 rpm for 15 minutes to fully mix the components to obtain reflective ink.

[0087] The resin connecting material is PU548 polyurethane resin.

[0088] The dispersant is sodium polymethacrylate R116306-1L from Roan Company.

[0089] The solvent is toluene.

[0090] The reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, and the particle size is 10 microns.

[0091] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0092] The preparation method of the piperazinylsilane-metal coordinated polyurethane modified glass microspheres is as follows:

[0093] T1 piperazine silane grafting:

[0094] 35 g of glass microspheres were added to a three-necked flask equipped with a condenser, a thermometer, and a stirrer. 300 g of anhydrous toluene was added, and the stirrer was turned on and stirred at 300 rpm. 3 g of 3-piperazinepropyltrimethoxysilane (CAS: 40762-28-5) with a purity of ≥97% was added. The reaction system temperature was raised to 100° C. using a heating mantle, and the reaction was refluxed and stirred for 5 hours. The glass microspheres were separated by filtration and then vacuum dried to constant weight to obtain piperazine-modified glass microspheres.

[0095] T2 metal coordination crosslinking:

[0096] 40g of polyester polyol with acid value ≤5mgKOH / g was added to a reactor equipped with a stirrer and a thermometer, and analytically pure zinc acetate was added according to 5% of the mass of the polyester polyol; the stirrer was turned on and the reaction was carried out at 120℃ for 4 hours to obtain Zn-containing 2+ Hydroxyl terminated polyester;

[0097] T3: piperazine-modified glass microspheres containing Zn 2+ The hydroxyl-terminated polyester and 8-hydroxyquinoline nickel were added into the reactor in a mass ratio of 1:0.8:0.3, stirred at a speed of 200 rpm, and reacted at 70°C for 4 hours. After the reaction, the modified glass microbeads were separated by filtration, washed with ethanol several times, and dried in vacuum to constant weight to obtain piperazine silane-metal coordinated polyurethane modified glass microbeads.

[0098] Comparative Example 1

[0099] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0100] S1 Pre-dispersion: Add 30g of resin binder, 1g of dispersant, and 10g of solvent into a stirring container and stir at 300 rpm for 10 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0101] S2: Add pigment and reflective microbeads: Add 5g of pigment and 20g of reflective microbeads to the mixed solution, increase the stirring speed to 800 rpm, and stir for 20 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0102] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 20 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0103] S4 post-treatment: 0.5 g of leveling agent, 0.5 g of Dow Corning AFE-1410 polydimethylsiloxane defoaming agent, and 10 g of solvent were added to the ground material, and stirred at a speed of 300 rpm for 10 minutes to fully mix the components to obtain reflective ink.

[0104] The resin connecting material is Hanwha S90 acrylic resin.

[0105] The dispersant is SP-02 sodium polyacrylate.

[0106] The solvent is ethyl acetate.

[0107] The reflective microbeads are glass microbeads with a particle size of 50 microns.

[0108] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0109] Comparative Example 2

[0110] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0111] S1 Pre-dispersion: Add 30g of resin binder, 1g of dispersant, and 10g of solvent into a stirring container and stir at 300 rpm for 10 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0112] S2: Add pigment and reflective microbeads: Add 5g of pigment and 20g of reflective microbeads to the mixed solution, increase the stirring speed to 800 rpm, and stir for 20 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0113] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 20 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0114] S4 post-treatment: 0.5 g of leveling agent, 0.5 g of Dow Corning AFE-1410 polydimethylsiloxane defoaming agent, and 10 g of solvent were added to the ground material, and stirred at a speed of 300 rpm for 10 minutes to fully mix the components to obtain reflective ink.

[0115] The resin connecting material is Hanwha S90 acrylic resin.

[0116] The dispersant is SP-02 sodium polyacrylate.

[0117] The solvent is ethyl acetate.

[0118] The reflective microbeads are modified glass microbeads with a particle size of 50 microns.

[0119] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0120] The preparation method of the modified glass microspheres is as follows:

[0121] T1 piperazine silane grafting:

[0122] 20 g of glass microspheres were added to a three-necked flask equipped with a condenser, a thermometer, and a stirrer. 200 g of anhydrous toluene was added, and the stirrer was turned on and stirred at 200 rpm. 1 g of 3-piperazinepropyltrimethoxysilane (CAS: 40762-28-5) with a purity of ≥97% was added. The reaction system temperature was raised to 80° C. using a heating mantle, and the reaction was refluxed and stirred for 2 hours. The glass microspheres were separated by filtration and then vacuum dried to constant weight to obtain piperazine-modified glass microspheres.

[0123] T2: piperazine-modified glass microspheres and 8-hydroxyquinoline nickel were added to a reactor at a mass ratio of 1:0.03, stirred at 150 rpm, and reacted at 60°C for 2 hours. After the reaction, the modified glass microspheres were separated by filtration, washed with ethanol multiple times, and dried in a vacuum dryer to a constant weight to obtain modified glass microspheres.

[0124] Comparative Example 3

[0125] A method for preparing a piperazine-based reflective ink, comprising the following steps:

[0126] S1 Pre-dispersion: Add 30g of resin binder, 1g of dispersant, and 10g of solvent into a stirring container and stir at 300 rpm for 10 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture;

[0127] S2: Add pigment and reflective microbeads: Add 5g of pigment and 20g of reflective microbeads to the mixed solution, increase the stirring speed to 800 rpm, and stir for 20 minutes to initially disperse the pigment and reflective microbeads in the mixed solution;

[0128] S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 20 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system;

[0129] S4 post-treatment: 0.5 g of leveling agent, 0.5 g of Dow Corning AFE-1410 polydimethylsiloxane defoaming agent, and 10 g of solvent were added to the ground material, and stirred at a speed of 300 rpm for 10 minutes to fully mix the components to obtain reflective ink.

[0130] The resin connecting material is Hanwha S90 acrylic resin.

[0131] The dispersant is SP-02 sodium polyacrylate.

[0132] The solvent is ethyl acetate.

[0133] The reflective microbeads are modified glass microbeads with a particle size of 50 microns.

[0134] The leveling agent is polyethylene glycol type polyether modified silicone leveling agent Silok-355.

[0135] The preparation method of the modified glass microspheres is as follows:

[0136] T1 piperazine silane grafting:

[0137] 20 g of glass microspheres were added to a three-necked flask equipped with a condenser, a thermometer, and a stirrer. 200 g of anhydrous toluene was added, and the stirrer was turned on and stirred at 200 rpm. 1 g of 3-piperazinepropyltrimethoxysilane (CAS: 40762-28-5) with a purity of ≥97% was added. The reaction system temperature was raised to 80° C. using a heating mantle, and the reaction was refluxed and stirred for 2 hours. The glass microspheres were separated by filtration and then vacuum dried to constant weight to obtain piperazine-modified glass microspheres.

[0138] T2 metal coordination crosslinking:

[0139] Add 20g of polyester polyol with acid value ≤5mgKOH / g into a reactor equipped with a stirrer and a thermometer, add analytically pure zinc acetate according to 2% of the mass of the polyester polyol; turn on the stirrer and react at 100℃ for 2 hours to obtain Zn-containing 2+ Hydroxyl terminated polyester;

[0140] T3: piperazine-modified glass microspheres containing Zn 2+ The hydroxyl-terminated polyester was added into the reactor at a mass ratio of 1:0.6, stirred at a speed of 150 rpm, and reacted at 60°C for 2 hours. After the reaction, the modified glass microbeads were separated by filtration, washed with ethanol several times, and dried in vacuum to constant weight to obtain modified glass microbeads.

[0141] Table 1: Test results of Examples and Comparative Examples

[0142] <![CDATA[0° / cd / lx·m 2 ]]> <![CDATA[10° / cd / lx·m 2 ]]> <![CDATA[30° / cd / lx·m 2 ]]> <![CDATA[60° / cd / lx·m 2 ]]> Example 1 234.5 215.7 203.6 185.9 Example 2 236.1 217.3 205.1 188.0 Example 3 239.2 219.5 208.5 191.4 Example 4 241.3 221.1 211.6 193.2 Comparative Example 1 200.7 188.2 161.9 133.7 Comparative Example 2 225.4 207.5 196.7 169.1 Comparative Example 3 228.6 209.8 198.3 172.6

[0143] Through the data analysis of the above examples and comparative examples, the reflective ink prepared by the present invention has a higher retroreflection coefficient and a good reflective effect.

[0144] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a piperazine-based reflective ink, comprising the following steps: S1 Pre-dispersion: Add 30-50 parts of resin binder, 1-5 parts of dispersant, and 10-20 parts of solvent into a stirring container, and stir at a speed of 300-500 rpm for 10-20 minutes to fully dissolve the dispersant in the resin binder and solvent to form a uniform mixture; S2: Add pigment and reflective microbeads: Add 5-15 parts of pigment and 20-35 parts of reflective microbeads to the mixed solution, increase the stirring speed to 800-1200 rpm, and stir for 20-30 minutes to initially disperse the pigment and reflective microbeads in the mixed solution; S3 Grinding: Transfer the mixture to a grinder for grinding until the fineness of the material reaches 10-20 microns, so that the pigment and reflective microbeads are further refined and evenly dispersed in the mixed system; S4 post-treatment: add 0.5-3 parts of leveling agent, 0.5-3 parts of polydimethylsiloxane defoaming agent, and 10-20 parts of solvent to the ground material, stir at a speed of 300-500 rpm for 10-15 minutes to fully mix the components to obtain reflective ink; The reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, which are composed of piperazine-modified glass microbeads, Zn-containing 2+ It is prepared by reacting hydroxyl-terminated polyester and 8-hydroxyquinoline nickel.

2. The method for preparing a piperazine-based reflective ink according to claim 1, wherein: The resin connecting material is acrylic resin or polyurethane resin.

3. The method for preparing a piperazine-based reflective ink according to claim 1, wherein: The dispersant is one of sodium polyacrylate, ammonium polyacrylate and sodium polymethacrylate.

4. The method for preparing a piperazine-based reflective ink according to claim 1, wherein: The solvent is one of ethyl acetate, butanone and toluene.

5. The method for preparing a piperazine-based reflective ink according to claim 1, wherein: The reflective microbeads are piperazine-silane-metal coordinated polyurethane modified glass microbeads, and the particle size thereof is 10-50 microns.

6. The method for preparing a piperazine-based reflective ink according to claim 1, wherein: The leveling agent is one of a polyethylene glycol type polyether modified organic silicon leveling agent, a polypropylene glycol type polyether modified organic silicon leveling agent, and a polyethylene glycol-polypropylene glycol block type polyether modified organic silicon leveling agent.

7. The method for preparing a piperazine-based reflective ink according to claim 5, wherein: The preparation method of the piperazinylsilane-metal coordinated polyurethane modified glass microspheres is as follows: T1 piperazine silane grafting: Add 20-35 parts of glass microspheres to a three-necked flask equipped with a condenser, a thermometer, and a stirrer, add 200-300 parts of anhydrous toluene, start the stirrer, and stir at a speed of 200-300 rpm. Add 1-3 parts of 3-piperazinepropyltrimethoxysilane with a purity of ≥97%; raise the temperature of the reaction system to 80-100° C. using a heating mantle, and reflux and stir for 2-5 hours; filter and separate the glass microspheres, and then vacuum dry to constant weight to obtain piperazine-modified glass microspheres; T2 metal coordination crosslinking: Add 20-40 parts of polyester polyol with acid value ≤ 5mgKOH / g into a reaction kettle equipped with a stirrer and a thermometer, add analytically pure zinc acetate according to 2-5% of the mass of the polyester polyol; turn on the stirrer and react at 100-120℃ for 2-4 hours to obtain Zn-containing 2+ Hydroxyl terminated polyester; T3: piperazine-modified glass microspheres containing Zn 2+ The hydroxyl-terminated polyester and 8-hydroxyquinoline nickel are added into the reactor in a mass ratio of 1:0.6-0.8:0.03-0.3, stirred at a speed of 150-200 rpm, and reacted at 60-70°C for 2-4 hours. After the reaction, the modified glass microbeads are separated by filtration, washed with ethanol multiple times, and dried in vacuum to constant weight to obtain piperazine silane-metal coordinated polyurethane modified glass microbeads.