A kind of polyurethane ink preparation method

Abstract

The invention relates to the technical field of water-ink, and in particular to a method for preparing a polyurethane water-ink. The method comprises the following raw materials in parts by weight: 70-80 parts of acrylic resin liquid, 30-40 parts of deionized water, 8-10 parts of water-based pigment, 8-10 parts of ethanol, 8-12 parts of functional additives, 5-8 parts of connecting materials, 5-8 parts of wetting agents, 4-6 parts of defoaming agents, 1.2-1.8 parts of activators and 0.3-0.6 parts of drying agents. The invention prepares the functional additives as the main additive of the polyurethane water-ink by mixing modified ethoxylated polyurethane with water-based polyurethane adhesive. The modified ethoxylated polyurethane can form a stable structure in the water-ink, condense inside the polymer to form a three-dimensional network cross-linked structure, improve the cross-linking density of the water-ink structure, improve the density of the surface of the ink layer, and at the same time, produce an adsorption effect on the coating surface through the combination of its groups, so as to effectively improve the adhesion of the water-ink.

Description

Technical Field

[0001] The invention relates to the technical field of water-ink, in particular to a method for preparing polyurethane water-ink. Background Art

[0002] Water-based ink is a kind of printing ink with the characteristics of environmental protection, safety, low cost and excellent performance. In the printing industry, water-based ink plays an important role and promotes the continuous advancement of printing technology.

[0003] In the prior art, water-based ink has strong fluidity due to its water-based ratio, and poor adhesion after coating, which affects the coating effect of the ink. Based on this, the present invention provides a method for preparing polyurethane water-based ink. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a polyurethane ink. The ink prepared by the present invention not only has good adhesion performance, but also has excellent tinting performance, which effectively improves the applicability of the ink.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A polyurethane ink is composed of the following raw materials in parts by weight: 70-80 parts of acrylic resin liquid, 30-40 parts of deionized water, 8-10 parts of water-based pigment, 8-10 parts of ethanol, 8-12 parts of functional additives, 5-8 parts of connecting materials, 5-8 parts of wetting agents, 4-6 parts of defoaming agents, 1.2-1.8 parts of active agents and 0.3-0.6 parts of drying agents.

[0007] Preferably, the preparation method of the functional additive comprises the following steps:

[0008] Step 1, pre-mixing the modified ethoxylated polyurethane and the waterborne polyurethane adhesive in a ratio of 1:2-2.5, adding the mixture into a flask, stirring and heating to 30-35°C, adding 0.1-0.15 times the mass of the modified ethoxylated polyurethane hydroxyethyl cellulose, stirring and heating to 70-75°C, adding 0.05-0.08 times the mass of the modified ethoxylated polyurethane polystyrene, continuing to stir and heating to 80-85°C, then keeping the temperature for 50-60 minutes, adding alkanolamine to adjust the pH value to 7-8, and obtaining the first mixed material for standby use;

[0009] Step 2: Mix deionized water and polyvinyl alcohol at a mass ratio of 1:1.5-1.8 to obtain a prepared liquid, mix the first mixed material with the prepared liquid at a mass ratio of 1:0.5-0.6, stir and heat to 90-95°C, keep warm for 40-50 minutes, wait for cooling, and obtain the second mixed material for standby use;

[0010] Step 3: After mixing the first mixture and the second mixture, add alkanolamine to adjust the pH value to 6-7, add to the internal mixer after adjustment, and mix in the internal mixer for 1-1.5 hours at a temperature of 160-180°C. After mixing, wait for it to drop to room temperature, add to the mixing equipment, and stir at medium-low speed for 15-20 minutes to obtain the functional additive.

[0011] Preferably, the preparation method of the modified ethoxy polyurethane is as follows: carbonic anhydride and diol are mixed and reacted at a dosage ratio of 1:2-2.5 to obtain a first reaction liquid, 1.5-1.8 times the mass of the first reaction liquid of polycaprolactone polyol is obtained and mixed and added to a flask, 0.2-0.3 times the mass of the first reaction liquid of isophorone diisocyanate is obtained, the isophorone diisocyanate is preheated to 80-85°C, kept warm for 1-1.2h, cooled at room temperature to obtain a second reaction liquid, the first reaction liquid and the second reaction liquid are mixed and added to a beaker to obtain a preliminary mixed liquid, and the temperature is raised. The reaction mixture was heated to 60-65°C for 2-2.5h. During the reaction, isocyanate propyl triethoxysilane was added dropwise at intervals of 10-15min, and the total amount of addition was 2-3% of the mass in the beaker. After the reaction was completed, the temperature was lowered to 35-40°C and kept warm for 20-30min. Ammonia water was added to adjust the pH value to 8-8.5. Aqueous polyurethane emulsion and isophorone diamine were mixed at a mass ratio of 1:0.5-0.6 to obtain a third reaction liquid. The third reaction liquid with a mass of 0.1-0.15 times that of the first reaction liquid was added to the preliminary mixed liquid to obtain modified ethoxy polyurethane.

[0012] Preferably, the preparation method of the waterborne polyurethane adhesive is: mixing waterborne polyurethane resin and N-isobutyloxymethyl acrylamide at a mass ratio of 1:0.01-0.015, adding a mixing device after the mixing is completed, then adding methyl methacrylate accounting for 5-6% of the total amount as an adhesive, starting the mixing device and stirring and mixing at medium speed for 4-6 minutes to obtain a waterborne polyurethane adhesive.

[0013] Preferably, the preparation method of the binder is as follows: the binder uses bone glue as raw material, adds bone glue into the grinding chamber of a ball mill, starts the ball mill at a rotation speed of 500-600r / min and continues ball milling for 10-15min, obtains aggregate powder after grinding, mixes the aggregate powder with alum solution at a mass ratio of 1:2-2.5, and obtains the binder.

[0014] Preferably, the wetting agent is selected from one or more combinations of polyethylene glycol, alkyl silicone oil, and isomeric alcohol ethers, and the defoaming agent is selected from any one of methyl silicone oil and polysiloxane.

[0015] Preferably, the active agent is one or more combinations of sodium dodecylbenzene sulfonate, sodium benzene sulfonate, and sodium citrate, and the drying agent is any one of silicate and sodium silicate.

[0016] Preferably, the connecting material and the water-based pigment are pre-mixed before preparation, poured into a mixing device and stirred at high speed for 8-10 minutes, and allowed to settle after the stirring is completed, and the settling time is 6-8 hours. After the settling, the suspension is collected to obtain a pigment mixture.

[0017] Preferably, the pigment mixture is placed in an oven during the precipitation process to control the precipitation temperature, and the oven is set to maintain a temperature of 60-70° C. during the precipitation process.

[0018] Furthermore, a method for preparing a polyurethane ink comprises the following steps:

[0019] S1: Weigh the pigment mixture and acrylic resin liquid as needed and put them into the dispersion tank for preliminary mixing. Set the speed to 300-350rpm and the time to 1-1.5min;

[0020] S2: Deionized water, ethanol, functional additives, wetting agents, defoaming agents, activators and drying agents are weighed as needed and put into a dispersion tank, the speed is set to 700-750rpm, the time is 4-5min, all raw materials are mixed, and polyurethane ink is obtained.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention prepares a functional additive as the main additive of polyurethane ink by mixing modified ethoxylated polyurethane with water-based polyurethane adhesive. The modified ethoxylated polyurethane can form a stable structure in the ink and condense inside the polymer to form a three-dimensional network cross-linked structure, thereby increasing the cross-linking density of the ink structure and the density of the ink layer surface. At the same time, the combination of its groups produces an adsorption effect on the coating surface, thereby effectively improving the adhesion of the ink.

[0023] 2. The present invention achieves preliminary dispersion and purification of the colorant by separately treating the water-based pigment and the binder to form a pigment mixture, collecting the suspension through mixing and precipitation, and stirring and mixing the pigment mixture in batches. This preliminary dispersion and purification can reduce the agglomeration of the colorant during the subsequent stirring of the entire raw material, so that the colorant is evenly distributed in the ink, thereby improving the coloring power of the ink. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] Embodiment 1

[0026] A polyurethane ink is composed of the following raw materials in parts by weight: 70 parts of acrylic resin liquid, 30 parts of deionized water, 8 parts of water-based pigment, 8 parts of ethanol, 8 parts of functional additives, 5 parts of connecting materials, 5 parts of wetting agents, 4 parts of defoaming agents, 1.2 parts of activating agents and 0.3 parts of drying agents.

[0027] First, the preparation method of the functional additive comprises the following steps:

[0028] Step 1, pre-mix the modified ethoxy polyurethane and the water-based polyurethane adhesive in a ratio of 1:2, add them into a flask, stir and heat to 30°C, add 0.1 times the mass of the modified ethoxy polyurethane hydroxyethyl cellulose, stir and heat to 70°C, add 0.05 times the mass of the modified ethoxy polyurethane polystyrene, continue to stir and heat to 80°C, then keep warm for 50 minutes, add alkanolamine to adjust the pH value to 7, and the result is the first mixture for standby use;

[0029] Step 2: Mix deionized water and polyvinyl alcohol in a mass ratio of 1:1.5 to obtain a prepared liquid, mix the first mixed material with the prepared liquid in a mass ratio of 1:0.5, stir and heat to 90°C, keep warm for 40 minutes, wait for cooling, and obtain the second mixed material for standby use;

[0030] Step 3: After mixing the first mixture and the second mixture, add alkanolamine to adjust the pH value to 6. After the adjustment, add them to the internal mixer. Keep the internal mixer warm and mix for 1 hour at a temperature of 160°C. After mixing, wait for it to drop to room temperature, add it to the mixing equipment, and stir at medium-low speed for 15 minutes to obtain the functional additive.

[0031] The preparation method of the modified ethoxy polyurethane is as follows: carbonic anhydride and diol are mixed and reacted at a dosage ratio of 1:2 to obtain a first reaction liquid, polycaprolactone polyol with a mass of 1.5 times that of the first reaction liquid is obtained and mixed and added to a flask, isophorone diisocyanate with a mass of 0.2 times that of the first reaction liquid is obtained, isophorone diisocyanate is preheated to 80°C, kept warm for 1 hour, and cooled at room temperature to obtain a second reaction liquid, the first reaction liquid and the second reaction liquid are mixed and added to a beaker to obtain a preliminary mixed liquid, the temperature is raised to 60°C for reaction for 2 hours, isocyanate propyl triethoxy silane is added dropwise at intervals of 10 minutes during the reaction, and the total amount of dropwise addition is 2% of the mass in the beaker, the temperature is lowered to 35°C after the reaction is completed, and the temperature is kept warm for 20 minutes, ammonia water is added to adjust the pH value to 8, an aqueous polyurethane emulsion and isophorone diamine are mixed at a mass ratio of 1:0.5 to obtain a third reaction liquid, and the third reaction liquid with a mass of 0.1 times that of the first reaction liquid is obtained and added to the preliminary mixed liquid to obtain the modified ethoxy polyurethane.

[0032] Among them, the preparation method of the water-based polyurethane adhesive is: mix the water-based polyurethane resin and N-isobutyloxymethyl acrylamide in a mass ratio of 1:0.01, add a mixing device after the mixing is completed, and then add methyl methacrylate accounting for 5% of the total amount as an adhesive, start the mixing device and stir and mix at medium speed for 4 minutes to obtain the water-based polyurethane adhesive.

[0033] Furthermore, the preparation method of the binder is as follows: the binder uses bone glue as raw material, adds bone glue into the grinding chamber of a ball mill, starts the ball mill at a speed of 500r / min and continues ball milling for 10 minutes, obtains aggregate powder after grinding, mixes the aggregate powder with alum solution at a mass ratio of 1:2, and obtains the binder.

[0034] Furthermore, the wetting agent is polyethylene glycol, and the defoaming agent is methyl silicone oil.

[0035] Furthermore, the active agent is sodium dodecylbenzene sulfonate, and the drying agent is silicate.

[0036] Furthermore, the connecting material and the water-based pigment are pre-mixed before preparation, poured into a mixing device and stirred at high speed for 8 minutes, and allowed to settle after the stirring is completed, and the settling time is 6 hours. After the settling, the suspension is collected to obtain a pigment mixture.

[0037] Furthermore, the pigment mixture is placed in an oven during the precipitation process to control the precipitation temperature, and the oven is set to maintain a temperature of 60° C. during the precipitation process.

[0038] This embodiment also provides a method for preparing a polyurethane ink, comprising the following steps:

[0039] S1: Weigh the pigment mixture and acrylic resin liquid as needed and put them into the dispersion tank for preliminary mixing. Set the speed to 300 rpm and the time to 1 min.

[0040] S2: Deionized water, ethanol, functional additives, wetting agents, defoaming agents, activators and drying agents are weighed as needed and put into a dispersion tank. The speed is set to 700 rpm and the time is 4 minutes to complete the mixing of all raw materials to obtain polyurethane ink.

[0041] Embodiment 2

[0042] The preparation method of the polyurethane ink in this embodiment is basically the same as that in Example 1, except that the specific ratios of the raw materials used and the preparation methods of the functional additives used in the two are different. The specific ratios of the raw materials used to prepare the polyurethane ink in this embodiment and the preparation methods of the functional additives are as follows:

[0043] A polyurethane ink is composed of the following raw materials in parts by weight: 75 parts of acrylic resin liquid, 35 parts of deionized water, 9 parts of water-based pigment, 9 parts of ethanol, 10 parts of functional additives, 6 parts of connecting materials, 6 parts of wetting agents, 5 parts of defoaming agents, 1.5 parts of activators and 0.4 parts of drying agents.

[0044] First, the preparation method of the functional additive comprises the following steps:

[0045] Step 1: premix the modified ethoxylated polyurethane and the waterborne polyurethane adhesive in a ratio of 1:2.2, add them into a flask, stir and heat to 32°C, add 0.12 times the mass of the modified ethoxylated polyurethane hydroxyethyl cellulose, stir and heat to 72°C, add 0.06 times the mass of the modified ethoxylated polyurethane polystyrene, continue stirring and heat to 82°C, then keep warm for 55 minutes, add alkanolamine to adjust the pH value to 7.5, and obtain the first mixture for standby use;

[0046] Step 2: Deionized water and polyvinyl alcohol are mixed at a mass ratio of 1:1.6 to obtain a prepared liquid, and the first mixed material and the prepared liquid are mixed at a mass ratio of 1:0.55, and the mixture is stirred and heated to 92° C., and kept warm for 45 minutes. After cooling, the obtained mixture is a second mixed material for standby use;

[0047] Step 3: After mixing the first mixture and the second mixture, add alkanolamine to adjust the pH value to 6.5. After the adjustment, add it to the internal mixer. Keep the mixer warm and mix for 1.2 hours at a temperature of 170°C. After mixing, wait for it to drop to room temperature, add it to the mixing equipment, and stir at medium-low speed for 17 minutes. The result is a functional additive.

[0048] The preparation method of the modified ethoxy polyurethane is as follows: carbonic anhydride and diol are mixed and reacted at a dosage ratio of 1:2.2 to obtain a first reaction liquid, 1.6 times the mass of the first reaction liquid of polycaprolactone polyol is obtained and mixed and added to a flask, 0.25 times the mass of the first reaction liquid of isophorone diisocyanate is obtained, the isophorone diisocyanate is preheated to 82°C, kept warm for 1.1 hours, and cooled at room temperature to obtain a second reaction liquid, the first reaction liquid and the second reaction liquid are mixed and added to a beaker to obtain a preliminary mixed liquid. , heat to 62 ° C and react for 2.2 hours, add isocyanate propyl triethoxysilane dropwise at intervals of 12 minutes during the reaction, and the total amount of addition is 2.5% of the mass in the beaker. After the reaction is completed, cool to 40 ° C and keep warm for 25 minutes, add ammonia water to adjust the pH value to 8.2, mix the aqueous polyurethane emulsion and isophorone diamine in a mass ratio of 1:0.55 to obtain a third reaction liquid, obtain 0.12 times the mass of the first reaction liquid, and add the third reaction liquid to the preliminary mixed liquid to obtain modified ethoxy polyurethane.

[0049] Among them, the preparation method of the water-based polyurethane adhesive is: mix the water-based polyurethane resin and N-isobutyloxymethyl acrylamide in a mass ratio of 1:0.012, add a mixing device after the mixing is completed, and then add methyl methacrylate accounting for 5.5% of the total amount as an adhesive, start the mixing device and stir and mix at medium speed for 5 minutes to obtain the water-based polyurethane adhesive.

[0050] Furthermore, the preparation method of the binder is as follows: the binder uses bone glue as raw material, adds bone glue into the grinding chamber of a ball mill, starts the ball mill at a rotation speed of 550r / min and continues ball milling for 12 minutes, obtains aggregate powder after grinding, mixes the aggregate powder with alum solution at a mass ratio of 1:2.2, and obtains the binder.

[0051] Furthermore, the wetting agent is a combination of polyethylene glycol and isomeric alcohol ether, and the defoaming agent is polysiloxane.

[0052] Furthermore, the active agent is a combination of sodium benzenesulfonate and sodium citrate, and the drying agent is sodium silicate.

[0053] Furthermore, the connecting material and the water-based pigment are pre-mixed before preparation, poured into a mixing device and stirred at high speed for 9 minutes, and allowed to settle after the stirring is completed, and the settling time is 7 hours. After the settling, the suspension is collected to obtain a pigment mixture.

[0054] Furthermore, the pigment mixture is placed in an oven during the precipitation process to control the precipitation temperature, and the oven is set to maintain a temperature of 65°C during the precipitation process.

[0055] This embodiment also provides a method for preparing a polyurethane ink, comprising the following steps:

[0056] S1: Weigh the pigment mixture and acrylic resin liquid as needed and put them into the dispersion tank for preliminary mixing. Set the speed to 320 rpm and the time to 1.2 min.

[0057] S2: Deionized water, ethanol, functional additives, wetting agents, defoaming agents, activators and drying agents are weighed as needed and put into a dispersion tank. The speed is set to 720 rpm and the time is 4.5 min. All raw materials are mixed to obtain polyurethane ink.

[0058] Embodiment 3

[0059] The preparation method of the polyurethane ink in this embodiment is basically the same as that in Example 1, except that the specific ratios of the raw materials used and the preparation methods of the functional additives used in the two are different. The specific ratios of the raw materials used to prepare the polyurethane ink in this embodiment and the preparation methods of the functional additives are as follows:

[0060] A polyurethane ink is composed of the following raw materials in parts by weight: 80 parts of acrylic resin liquid, 40 parts of deionized water, 10 parts of water-based pigment, 10 parts of ethanol, 12 parts of functional additives, 8 parts of connecting materials, 8 parts of wetting agents, 6 parts of defoaming agents, 1.8 parts of activators and 0.6 parts of drying agents.

[0061] First, the preparation method of the functional additive comprises the following steps:

[0062] Step 1, pre-mix the modified ethoxylated polyurethane and the waterborne polyurethane adhesive in a ratio of 1:2.5, add them into a flask, stir and heat to 35°C, add 0.15 times the mass of the modified ethoxylated polyurethane hydroxyethyl cellulose, stir and heat to 75°C, add 0.08 times the mass of the modified ethoxylated polyurethane polystyrene, continue to stir and heat to 85°C, then keep warm for 60 minutes, add alkanolamine to adjust the pH value to 8, and the result is the first mixture for standby use;

[0063] Step 2: Mix deionized water and polyvinyl alcohol in a mass ratio of 1:1.8 to obtain a prepared liquid, mix the first mixed material with the prepared liquid in a mass ratio of 1:0.6, stir and heat to 95°C, keep warm for 50 minutes, wait for cooling, and obtain the second mixed material for standby use;

[0064] Step 3: After mixing the first mixture and the second mixture, add alkanolamine to adjust the pH value to 7. After the adjustment, add them to the internal mixer. Keep the mixer warm and mix for 1.5 hours at 180°C. After mixing, wait for it to drop to room temperature, add it to the mixing equipment, and stir at medium-low speed for 20 minutes to obtain the functional additive.

[0065] The preparation method of the modified ethoxy polyurethane is as follows: carbonic anhydride and diol are mixed and reacted at a dosage ratio of 1:2.5 to obtain a first reaction liquid, 1.8 times the mass of the first reaction liquid of polycaprolactone polyol is obtained and mixed and added to a flask, 0.3 times the mass of the first reaction liquid of isophorone diisocyanate is obtained, the isophorone diisocyanate is preheated to 85°C, kept warm for 1.2 hours, cooled at room temperature to obtain a second reaction liquid, the first reaction liquid and the second reaction liquid are mixed and added to a beaker to obtain a preliminary mixture. The mixture was heated to 65°C and reacted for 2.5 hours. During the reaction, isocyanatepropyltriethoxysilane was added dropwise at intervals of 15 minutes, and the total amount of addition was 3% of the mass in the beaker. After the reaction was completed, the temperature was lowered to 40°C and kept warm for 30 minutes. Ammonia water was added to adjust the pH value to 8.5. Aqueous polyurethane emulsion and isophoronediamine were mixed at a mass ratio of 1:0.6 to obtain a third reaction liquid. The third reaction liquid with a mass of 0.15 times that of the first reaction liquid was added to the preliminary mixed liquid to obtain modified ethoxy polyurethane.

[0066] Among them, the preparation method of the water-based polyurethane adhesive is: mix the water-based polyurethane resin and N-isobutyloxymethyl acrylamide in a mass ratio of 1:0.015, add a mixing device after the mixing is completed, and then add methyl methacrylate accounting for 6% of the total amount as an adhesive, start the mixing device and stir and mix at medium speed for 6 minutes to obtain the water-based polyurethane adhesive.

[0067] Furthermore, the preparation method of the binder is as follows: the binder uses bone glue as raw material, adds bone glue into the grinding chamber of a ball mill, starts the ball mill at a speed of 600r / min and continues ball milling for 15 minutes, and after grinding, aggregate powder is obtained, and the aggregate powder is mixed with alum solution at a mass ratio of 1:2.5 to obtain the binder.

[0068] Furthermore, the wetting agent is isomeric alcohol ether, and the defoaming agent is methyl silicone oil.

[0069] Furthermore, the active agent is sodium citrate and the drying agent is sodium silicate.

[0070] Furthermore, the connecting material and the water-based pigment are pre-mixed before preparation, poured into a mixing device and stirred at high speed for 10 minutes, and allowed to settle after the stirring is completed, and the settling time is 8 hours. After the settling, the suspension is collected to obtain a pigment mixture.

[0071] Furthermore, the pigment mixture is placed in an oven during the precipitation process to control the precipitation temperature, and the oven is set to maintain a temperature of 70° C. during the precipitation process.

[0072] This embodiment also provides a method for preparing a polyurethane ink, comprising the following steps:

[0073] S1: Weigh the pigment mixture and acrylic resin liquid as needed and put them into the dispersion tank for preliminary mixing. Set the speed to 350 rpm and the time to 1.5 min.

[0074] S2: Deionized water, ethanol, functional additives, wetting agents, defoaming agents, activators and drying agents are weighed as needed and put into a dispersion tank. The speed is set to 750 rpm and the time is 5 minutes to complete the mixing of all raw materials to obtain polyurethane ink.

[0075] Comparative Example 1: The difference between this comparative example and Example 1 is that this example uses an equal amount of aqueous polyurethane emulsion to replace the functional additive.

[0076] Comparative Example 2: The difference between this comparative example and Example 1 is that this example does not contain a connecting material.

[0077] Comparative Example 3: The difference between this comparative example and Example 1 is that in this example, no isocyanatepropyltriethoxysilane is added when preparing the functional additive.

[0078] Comparative Example 4: The difference between this comparative example and Example 1 is that this example does not contain a functional additive.

[0079] Performance test: The relevant properties of the polyurethane ink samples provided in Examples 1-3 and Comparative Examples 1-4 were tested respectively;

[0080] In the performance test, the adhesion test method is: according to the sample substrate, the ink film is cut into a grid pattern with a grid cutter with different spacings, so that it just penetrates the substrate, and the resistance of the ink film to separation from the substrate is evaluated. The area of ​​the ink film falling off from the substrate in the grid area is evaluated, and the grades are 0 to 5, with 0 being the best and 5 being the worst;

[0081] The test method for tinting strength is: after the ink is evenly coated on the surface of the substrate, the surface color is inspected at an incident angle of (45±5)° and under a standard light source, and the inspected color grade is evaluated. The evaluation results are divided into A, B, and C, among which A is the best and C is the worst;

[0082] The test data obtained are recorded in the following table:

[0083]

[0084] By comparing and analyzing the relevant data in the table, it can be seen that the polyurethane ink prepared by the present invention not only has good adhesion performance, but also has excellent tinting performance. This shows that the polyurethane ink and the preparation method provided by the present invention have a broader market prospect and are more suitable for promotion.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A polyurethane ink, characterized in that: The method is composed of the following raw materials in parts by weight: 70-80 parts of acrylic resin liquid, 30-40 parts of deionized water, 8-10 parts of water-based pigment, 8-10 parts of ethanol, 8-12 parts of functional additives, 5-8 parts of connecting materials, 5-8 parts of wetting agents, 4-6 parts of defoaming agents, 1.2-1.8 parts of active agents and 0.3-0.6 parts of drying agents; The preparation method of the functional additive comprises the following steps: Step 1, pre-mixing the modified ethoxylated polyurethane and the waterborne polyurethane adhesive in a ratio of 1:2-2.5, adding the mixture into a flask, stirring and heating to 30-35°C, adding 0.1-0.15 times the mass of the modified ethoxylated polyurethane hydroxyethyl cellulose, stirring and heating to 70-75°C, adding 0.05-0.08 times the mass of the modified ethoxylated polyurethane polystyrene, continuing to stir and heating to 80-85°C, then keeping the temperature for 50-60 minutes, adding alkanolamine to adjust the pH value to 7-8, and obtaining the first mixed material for standby use; Step 2: Mix deionized water and polyvinyl alcohol at a mass ratio of 1:1.5-1.8 to obtain a prepared liquid, mix the first mixed material with the prepared liquid at a mass ratio of 1:0.5-0.6, stir and heat to 90-95°C, keep warm for 40-50 minutes, wait for cooling, and obtain the second mixed material for standby use; Step 3, after mixing the first mixed material and the second mixed material, add alkanolamine to adjust the pH value to 6-7, add them to the internal mixer after adjustment, and mix them in the internal mixer for 1-1.5 hours at a temperature of 160-180°C. After mixing, wait for it to cool to room temperature, add it to the mixing equipment, and stir at medium-low speed for 15-20 minutes to obtain the functional additive; The preparation method of the modified ethoxy polyurethane comprises: mixing carbonic anhydride and diol at a dosage ratio of 1:2-2.5 to obtain a first reaction liquid, obtaining polycaprolactone polyol with a mass of 1.5-1.8 times that of the first reaction liquid, mixing and adding the mixture into a flask, obtaining isophorone diisocyanate with a mass of 0.2-0.3 times that of the first reaction liquid, preheating the isophorone diisocyanate to 80-85° C., keeping the temperature for 1-1.2 hours, cooling at room temperature to obtain a second reaction liquid, mixing the first reaction liquid and the second reaction liquid into a flask, obtaining a preliminary mixed solution, heating the mixture to 6 0-65℃ for reaction for 2-2.5h, during the reaction process, add isocyanate propyl triethoxysilane dropwise at intervals of 10-15min, and the total amount of dropwise addition is 2-3% of the mass of the preliminary mixed solution, after the reaction is completed, cool to 35-40℃ for 20-30min, add ammonia water to adjust the pH value to 8-8.5, mix the aqueous polyurethane emulsion and isophorone diamine at a mass ratio of 1:0.5-0.6 to obtain a third reaction solution, obtain the third reaction solution with a mass of 0.1-0.15 times of the first reaction solution, and add it to the preliminary mixed solution to obtain a modified ethoxy polyurethane; The preparation method of the waterborne polyurethane adhesive comprises: mixing waterborne polyurethane resin and N-isobutyloxymethyl acrylamide at a mass ratio of 1:0.01-0.015, adding a mixing device after the mixing is completed, then adding methyl methacrylate accounting for 5-6% of the total amount as an adhesive, starting the mixing device and stirring and mixing at a medium speed for 4-6 minutes, thereby obtaining the waterborne polyurethane adhesive; The preparation method of the connecting material is as follows: the connecting material uses bone glue as a raw material, the bone glue is added into the grinding chamber of a ball mill, the ball mill is started at a rotation speed of 500-600r / min and the ball milling is continued for 10-15min, after the grinding is completed, the bone glue powder is obtained, and the bone glue powder is mixed with an alum solution at a mass ratio of 1:2-2.5 to obtain the connecting material; The connecting material and the water-based pigment are pre-mixed before preparation, poured into a mixing device after mixing and stirred at high speed for 8-10 minutes, and allowed to stand for precipitation after the stirring, the precipitation time is 6-8 hours, and the suspension is collected after standing for precipitation to obtain a pigment mixture; The pigment mixture is placed in an oven during the precipitation process to control the precipitation temperature, and the oven is set to maintain a temperature of 60-70°C during the precipitation process.

2. The polyurethane ink according to claim 1, characterized in that: The wetting agent is selected from one or more combinations of polyethylene glycol, alkyl silicone oil, and isomeric alcohol ethers, and the defoaming agent is selected from any one of methyl silicone oil and polysiloxane.

3. The polyurethane ink according to claim 1, characterized in that: The active agent is selected from one or more combinations of sodium dodecylbenzene sulfonate, sodium benzene sulfonate, and sodium citrate, and the drying agent is selected from silicate.

4. A method for preparing a polyurethane ink according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Weigh the pigment mixture and acrylic resin liquid as needed and put them into the dispersion tank for preliminary mixing. Set the speed to 300-350rpm and the time to 1-1.5min; S2: Deionized water, ethanol, functional additives, wetting agents, defoaming agents, activators and drying agents are weighed as needed and put into a dispersion tank, the speed is set to 700-750rpm, the time is 4-5min, all raw materials are mixed, and polyurethane ink is obtained.

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