Anti-settling universal white coating paste and preparation method thereof

Abstract

The present application relates to the field of paint, in particular to a kind of anti-settling general white paste of paint and its preparation method, for solving the existing traditional white paste in the storage process prone to sedimentation phenomenon, lead to uneven distribution of pigment, and the short metamorphic time of white paste problem;The main raw material of the white paste is composite white pigment, the composite white pigment has high tinting strength and hiding power, and the advantages of non-toxic and non-polluting, strong chemical stability, and after adding sedimentation inhibitor to it, the surface tension between composite white pigment particles can be reduced, so that it is easy to disperse and keep stable state, can increase the cohesion of paste, prevent the sedimentation of composite white pigment particles during storage;The white paste of the present application has good anti-settling performance and stability by reasonable formula and preparation process, can meet the preparation needs of different paints.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paint, in particular to a paint universal white paste capable of preventing sedimentation and a preparation method thereof. BACKGROUND

[0002] Paint is a widely used chemical product, which is used for decorating and protecting various material surfaces. White paste is a basic pigment in paint, which is widely used in various paint products due to its high hiding power and reflection performance. However, the conventional white paste is prone to sedimentation during storage, which leads to uneven distribution of pigments and affects the performance and aesthetics of the paint. Moreover, titanium dioxide, which is the main raw material of the white paste, has some drawbacks: firstly, titanium dioxide is prone to agglomeration, which leads to the failure of the excellent performance of titanium dioxide; secondly, titanium dioxide has photocatalytic activity and is prone to generate free radicals, which leads to the accelerated deterioration of the white paste.

[0003] Therefore, it is of great practical significance to develop a paint universal white paste capable of preventing sedimentation and a preparation method thereof. SUMMARY

[0004] In order to overcome the above technical problems, the purpose of the present application is to provide a paint universal white paste capable of preventing sedimentation and a preparation method thereof: the composite white pigment, the sedimentation inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoaming agent and the ethanol solution are added into a mixing machine and stirred and mixed, and then placed in a grinding machine for grinding to obtain the paint universal white paste capable of preventing sedimentation, which solves the problems of the conventional white paste, such as the sedimentation during storage, the uneven distribution of pigments and the short deterioration time of the white paste.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] A paint universal white paste capable of preventing sedimentation comprises the following components by weight:

[0007] 35-55 parts of composite white pigment, 3.5-9.5 parts of sedimentation inhibitor, 32-46 parts of acrylic resin, 5-9 parts of butyl acetate, 3-5 parts of diethylene glycol monobutyl ether, 1.5-2.5 parts of defoaming agent and 10-15 parts of ethanol solution;

[0008] The composite white pigment is prepared by the following steps:

[0009] The nano-titanium dioxide, sodium hexametaphosphate and deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, and ultrasonic treatment is carried out for 10-15 min under the condition of ultrasonic power of 200-300 W, and then stirring reaction is carried out for 15-20 min under the condition of temperature of 60-65 DEG C and stirring speed of 300-350 r / min, and then the pH is adjusted to 9-9.5 by using a sodium hydroxide solution, and then a sodium silicate solution is added and stirring reaction is carried out for 1-1.5 h, and then a cerium sulfate solution is added and stirring reaction is carried out for 2-3 h, and then the reaction product is cooled to room temperature, and then centrifugation is carried out, and the precipitate is washed with distilled water for 2-3 times, and then it is placed in a vacuum drying oven and dried for 8-10 h under the condition of temperature of 80-85 DEG C, and then it is crushed to obtain the composite white pigment.

[0010] As a further scheme of the present application, the defoaming agent is BYK088 silicone defoaming agent, and the volume fraction of the ethanol solution is 85-95%.

[0011] As a further scheme of the present application, the use amount ratio of the nano-titanium dioxide, sodium hexametaphosphate, deionized water, sodium silicate solution and cerium sulfate solution is 10 g:0.1-0.15 g:25-30 mL:15-20 mL:15-20 mL.

[0012] As a further scheme of the present application, the mass fraction of the sodium hydroxide solution is 20-25%, the molar concentration of the sodium silicate solution is 0.1 mol / L, and the molar concentration of the cerium sulfate solution is 0.1 mol / L.

[0013] As a further scheme of the present application, the settling inhibitor is prepared by the following steps:

[0014] Step s1: tetraphenylmethane and fuming nitric acid are added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a constant pressure dropping funnel, and nitrogen protection is carried out, and stirring reaction is carried out for 1-1.5 h under the condition of temperature of -30 DEG C and stirring speed of 300-350 r / min, and then acetic anhydride solution is added drop by drop while stirring, and the dropping speed is controlled to be 1-2 drops / s, and after the addition is completed, acetic acid is added and the temperature is increased to 25-30 DEG C, and then stirring reaction is carried out for 4-5 h, and then the reaction product is vacuum filtered, and then the filter cake is washed with anhydrous ethanol for 3-5 times, and then it is placed in a vacuum drying oven and dried for 2-3 h under the condition of temperature of 60-65 DEG C to obtain intermediate 1.

[0015] Step s2: Intermediate 1, 5% palladium-carbon and anhydrous ethanol were added into a three-necked flask equipped with a stirrer, thermometer, nitrogen inlet pipe, reflux condenser and constant pressure dropping funnel, and the flask was protected by nitrogen, and then stirred at a temperature of 25-30 DEG C and a stirring speed of 300-350 r / min for 15-20 min, and then hydrazine hydrate solution was added dropwise while stirring, and the dropping speed was controlled at 1-2 drops / s, and after the addition was completed, the reaction was continued at a refluxing temperature for 15-20 h, and then the reaction product was cooled to room temperature, and then the solvent was removed by rotary evaporation, and then eluted with a mixed solvent, and then placed in a vacuum drying oven, and dried at a temperature of 40-45 DEG C for 5-6 h to obtain intermediate 2.

[0016] Step s3: Intermediate 2, (3-chloropropyl)triethoxysilane, anhydrous potassium carbonate, potassium iodide and anhydrous toluene were added into a three-necked flask equipped with a stirrer, thermometer and nitrogen inlet pipe, and the flask was protected by nitrogen, and then stirred at a temperature of -5-0 DEG C and a stirring speed of 300-350 r / min for 30-50 min, and then the reaction was continued at a temperature of 80-85 DEG C for 25-30 h, and then the reaction product was cooled to room temperature, and then filtered under vacuum, and the filtrate was rotary evaporated to remove the solvent, and then washed with anhydrous ethanol for 3-5 times, and then placed in a vacuum drying oven, and dried at a temperature of 35-40 DEG C for 8-10 h to obtain the sedimentation inhibitor.

[0017] As a further scheme of the present application: the amount ratio of the tetraphenylmethane, fuming nitric acid, acetic anhydride solution and acetic acid in step s1 is 10 mmol: 18-22 mL: 15-20 mL: 40-50 mL.

[0018] As a further scheme of the present application: the mass fraction of the fuming nitric acid in step s1 is 97.5%, and the acetic anhydride solution is a solution formed by dissolving acetic anhydride in acetic acid at a volume ratio of 1:1.8-2.

[0019] As a further scheme of the present application: the amount ratio of the intermediate 1, 5% palladium-carbon, anhydrous ethanol and hydrazine hydrate solution in step s2 is 1 g: 0.2-0.25 g: 50-55 mL: 5-8 mL.

[0020] As a further scheme of the present application: the mass fraction of the hydrazine hydrate solution in step s2 is 85%, and the mixed solvent is a mixture of anhydrous ethanol and dichloromethane at a volume ratio of 1:9.

[0021] As a further scheme of the present application: the amount ratio of the intermediate 2, (3-chloropropyl) triethoxysilane, anhydrous potassium carbonate, potassium iodide and anhydrous toluene in step s3 is 10 mmol: 45-50 mmol: 50-55 mmol: 5-6 mmol: 120-150 mL.

[0022] As a further scheme of the present application: a preparation method of the anti-settling universal white paste for paint, comprising the following steps:

[0023] Step one: according to the weight part, the composite white pigment 35-55 parts, the settling inhibitor 3.5-9.5 parts, the acrylic resin 32-46 parts, the butyl acetate 5-9 parts, the diethylene glycol monobutyl ether 3-5 parts, the defoaming agent 1.5-2.5 parts and the ethanol solution 10-15 parts are weighed and prepared;

[0024] Step two: the composite white pigment, the settling inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoaming agent and the ethanol solution are added into the mixing machine, then stirred and mixed under the condition that the temperature is 25-30 DEG C and the stirring rate is 300-350 r / min for 20-30 min, then placed in the grinding machine and ground under the condition that the temperature is 60-65 DEG C and the stirring rate is 150-200 r / min for 3-6 h, to obtain the anti-settling universal white paste for paint.

[0025] The beneficial effects of the present application:

[0026] The anti-settling universal white paste for paint and the preparation method thereof, the composite white pigment, the settling inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoaming agent and the ethanol solution are added into the mixing machine and stirred and mixed, then placed in the grinding machine and ground, to obtain the anti-settling universal white paste for paint; the main raw material of the white paste is the composite white pigment, the composite white pigment has the advantages of high color strength and hiding power, non-toxic and non-polluting, strong chemical stability, and after adding the settling inhibitor, the surface tension between the composite white pigment particles is reduced, so that it is easy to disperse and keep stable state, the cohesiveness of the paste can be increased, and the composite white pigment particles can be prevented from settling during storage; the white paste of the present application has good anti-settling performance and stability through reasonable formula and preparation process, and can meet the preparation requirements of different paints.

[0027] The process for preparing the anti-settling universal white paste for paint comprises the following steps: firstly, a composite white pigment is prepared, wherein the composite white pigment is prepared by taking nano titanium dioxide as the core, and then treating the core with sodium silicate solution and cerium sulfate solution to form a SiO2 and CeO2 composite film layer on the surface of the core; the titanium dioxide has high purity, soft color, good whiteness, high refractive index, large scattering coefficient and large absorption coefficient, and thus has good hiding power; the SiO2 and CeO2 composite film layer coated on the titanium dioxide can reduce the photocatalytic activity of the titanium dioxide, improve the dispersion performance of the titanium dioxide, make the titanium dioxide uniformly dispersed in the white paste, improve the stability of the titanium dioxide, enhance the anti-settling effect, and avoid the generation of free radicals caused by photocatalysis and the decline of the performance of the paint;

[0028] The process for preparing the anti-settling universal white paste for paint also comprises the following steps: firstly, tetraphenylmethane is nitrified by fuming nitric acid to introduce a nitro group into the para position of the benzene ring of the tetraphenylmethane to obtain an intermediate 1; then, the intermediate 1 is treated with hydrazine hydrate to reduce the nitro group into an amino group to obtain an intermediate 2; finally, the intermediate 2 is reacted with (3-chloropropyl)triethoxysilane to introduce siloxane through a nucleophilic substitution reaction between the amino group of the intermediate 2 and the chlorine atom of the (3-chloropropyl)triethoxysilane to obtain the anti-settling agent; the anti-settling agent contains a large number of siloxane groups, and the siloxane groups can form silanol after hydrolysis, which can dehydrate and condense with the hydroxyl groups on the surface of the composite white pigment particles, so as to improve the dispersibility of the composite white pigment, make the composite white pigment disperse and stably exist in the color paste, and prevent the composite white pigment from settling. BRIEF DESCRIPTION OF DRAWINGS

[0029] The application will be further described below with reference to the drawings.

[0030] Figure 1 is a process flow chart of the preparation method of the anti-settling universal white paste for paint in the application;

[0031] Figure 2 is a scanning electron microscope image of the nano titanium dioxide in the application;

[0032] Figure 3 is a scanning electron microscope image of the composite white pigment in the application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0034] Embodiment 1:

[0035] Referring to Figure 1 The embodiment is a preparation method of a general white paste capable of preventing sedimentation, comprising the following steps:

[0036] Step one: 35 parts of composite white pigment, 3.5 parts of sedimentation inhibitor, 32 parts of acrylic resin, 5 parts of butyl acetate, 3 parts of diethylene glycol monobutyl ether, 1.5 parts of defoaming agent and 10 parts of ethanol solution are weighed according to weight parts for standby; the defoaming agent is BYK088 silicone defoaming agent, and the volume fraction of the ethanol solution is 85%;

[0037] Step two: the composite white pigment, the sedimentation inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoaming agent and the ethanol solution are added into a mixer, and then stirred and mixed under the condition that the temperature is 25°C and the stirring rate is 300 r / min for 20 min, and then placed in a grinder and ground under the condition that the temperature is 60°C and the stirring rate is 150 r / min for 3 h, to obtain the general white paste capable of preventing sedimentation;

[0038] The composite white pigment is prepared by the following steps:

[0039] 10 g of nanometer titanium dioxide, 0.1 g of sodium hexametaphosphate and 25 mL of deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, ultrasonic treatment is carried out under the condition that the ultrasonic power is 200 W for 10 min, then stirring reaction is carried out under the condition that the temperature is 60°C and the stirring rate is 300 r / min for 15 min, then the pH is adjusted to 9 with a 20% sodium hydroxide solution, then 15 mL of 0.1 mol / L sodium silicate solution is added and stirring reaction is continued for 1 h, then 15 mL of 0.1 mol / L cerium sulfate solution is added and stirring reaction is continued for 2 h, the reaction product is cooled to room temperature after the reaction is completed, then centrifugation is carried out, the precipitate is washed with distilled water for 2 times, then placed in a vacuum drying oven and dried under the condition that the temperature is 80°C for 8 h, then crushed to obtain the composite white pigment;

[0040] The sedimentation inhibitor is prepared by the following steps:

[0041] Step s1: 10 mmol of tetraphenylmethane, 18 mL of 97.5% fuming nitric acid were added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a constant pressure dropping funnel, and stirred at a temperature of -30°C and a stirring speed of 300 r / min for 1 h under nitrogen protection, then 15 mL of acetic anhydride solution dissolved in acetic acid at a volume ratio of 1:1.8 was added dropwise while stirring at a dropping speed of 1 drop / s, after the addition was completed, 40 mL of acetic acid was added and the reaction was continued to stir at a temperature of 25°C for 4 h, then the reaction product was vacuum filtered, the filter cake was washed with anhydrous ethanol for 3 times, and then placed in a vacuum drying oven for drying at a temperature of 60°C for 2 h to obtain intermediate 1;

[0042] Step s2: 1 g of intermediate 1, 0.2 g of 5% palladium-carbon and 50 mL of anhydrous ethanol were added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a reflux condenser and a constant pressure dropping funnel, and stirred at a temperature of 25°C and a stirring speed of 300 r / min for 15 min under nitrogen protection, then 5 mL of 85% hydrazine hydrate solution was added dropwise while stirring at a dropping speed of 1 drop / s, after the addition was completed, the reaction was continued to stir at reflux for 15 h, then the reaction product was cooled to room temperature, the solvent was removed by rotary evaporation, then eluted with a mixed solvent of anhydrous ethanol and dichloromethane at a volume ratio of 1:9, and then placed in a vacuum drying oven for drying at a temperature of 40-45°C for 5 h to obtain intermediate 2;

[0043] Step s3: 10 mmol of intermediate 2, 45 mmol of (3-chloropropyl)triethoxysilane, 50 mmol of anhydrous potassium carbonate, 5 mmol of potassium iodide and 120 mL of anhydrous toluene were added into a three-necked flask equipped with a stirrer, a thermometer and a nitrogen inlet tube, and stirred at a temperature of -5°C and a stirring speed of 300 r / min for 30 min under nitrogen protection, then the reaction was continued to stir at a temperature of 80°C for 25 h, then the reaction product was cooled to room temperature, the filtrate was rotary evaporated to remove the solvent, then washed with anhydrous ethanol for 3 times, and then placed in a vacuum drying oven for drying at a temperature of 35°C for 8 h to obtain the sedimentation inhibitor.

[0044] Example 2:

[0045] Please refer to Figure 1 As shown in the figure, the present embodiment is a preparation method of a general white paint slurry capable of preventing sedimentation, comprising the following steps:

[0046] Step one: according to the weight part, 45 parts of composite white pigment, 6.5 parts of sedimentation inhibitor, 39 parts of acrylic resin, 7 parts of butyl acetate, 4 parts of diethylene glycol monobutyl ether, 2.0 parts of defoaming agent and 12 parts of ethanol solution are weighed, and prepared for use; the defoaming agent is BYK088 silicone defoaming agent, and the volume fraction of the ethanol solution is 90%;

[0047] Step two: the composite white pigment, the sedimentation inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoaming agent and the ethanol solution are added into a mixer, then stirred and mixed at a temperature of 28℃ and a stirring rate of 325r / min for 25min, and then placed in a grinder, and grinded at a temperature of 62℃ and a stirring rate of 175r / min for 4.5h, to obtain the anti-settling general white paste of the paint;

[0048] The composite white pigment is prepared by the following steps:

[0049] 10g of nanometer titanium dioxide, 0.12g of sodium hexametaphosphate and 28mL of deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, and ultrasonic treated at an ultrasonic power of 250W for 12min, then stirred and reacted at a temperature of 62℃ and a stirring rate of 325r / min for 18min, then adjusted to pH 9.2 with a 22wt% sodium hydroxide solution, then added 18mL of a 0.1mol / L sodium silicate solution and continued to stir and react for 1.2h, then added 18mL of a 0.1mol / L cerium sulfate solution and continued to stir and react for 2.5h, and then cooled to room temperature, centrifuged, washed the precipitate with distilled water for 2 times, and then placed in a vacuum drying oven and dried at a temperature of 82℃ for 9h, then crushed to obtain the composite white pigment;

[0050] The sedimentation inhibitor is prepared by the following steps:

[0051] Step s1: 10mmol of tetraphenylmethane and 20mL of 97.5wt% fuming nitric acid are added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a constant pressure dropping funnel, and protected by nitrogen, then stirred and reacted at a temperature of -30℃ and a stirring rate of 325r / min for 1.2h, then added 18mL of acetic anhydride solution dissolved in acetic acid at a volume ratio of 1:1.9 drop by drop while stirring, and controlled the dropping rate to be 2 drops / s, after the dropping was completed, 45mL of acetic acid was added and the temperature was increased to 28℃, and the stirring was continued for 4.5h, then the reaction product was vacuum filtered, then the filter cake was washed with anhydrous ethanol for 4 times, and then placed in a vacuum drying oven and dried at a temperature of 62℃ for 2.5h to obtain the intermediate 1;

[0052] Step s2: 1 g of intermediate 1, 0.22 g of 5% palladium on carbon, and 52 mL of absolute ethanol were added to a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a reflux condenser, and a constant-pressure dropping funnel, and the mixture was stirred at a temperature of 28°C and a stirring rate of 325 r / min under nitrogen protection for 18 min, after which 7 mL of 85% hydrazine hydrate was added dropwise to the mixture while stirring, the dropping rate was controlled at 1 drop / s, and after the addition was completed, the reaction was continued at a reflux temperature for 18 h, the reaction product was cooled to room temperature, the solvent was removed by rotary evaporation, the product was eluted with a mixed solvent of absolute ethanol and dichloromethane (1:9 by volume), and then the product was placed in a vacuum drying oven and dried at a temperature of 42°C for 5.5 h to obtain intermediate 2;

[0053] Step s3: 10 mmol of intermediate 2, 48 mmol of (3-chloropropyl)triethoxysilane, 52 mmol of anhydrous potassium carbonate, 5.5 mmol of potassium iodide, and 135 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, and the mixture was stirred at a temperature of -3°C and a stirring rate of 325 r / min under nitrogen protection for 40 min, after which the temperature was increased to 82°C and the reaction was continued for 28 h, the reaction product was cooled to room temperature, and then filtered under vacuum, the filtrate was rotary evaporated to remove the solvent, and then washed with absolute ethanol 4 times, and then placed in a vacuum drying oven and dried at a temperature of 38°C for 9 h to obtain the sedimentation inhibitor.

[0054] Example 3:

[0055] See Figure 1 As shown in the figure, the present embodiment is a preparation method of a general white paste for anti-settling paint, which comprises the following steps:

[0056] Step one: the composite white pigment 55 parts, the sedimentation inhibitor 9.5 parts, the acrylic resin 46 parts, the butyl acetate 9 parts, the diethylene glycol monobutyl ether 5 parts, the defoamer 2.5 parts, and the ethanol solution 15 parts were weighed according to the weight parts, and were prepared for use; the defoamer was BYK088 silicone defoamer, and the volume fraction of the ethanol solution was 95%;

[0057] Step two: the composite white pigment, the sedimentation inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoamer, and the ethanol solution were added to a mixer, and then stirred and mixed at a temperature of 30°C and a stirring rate of 350 r / min for 30 min, and then placed in a grinder and ground at a temperature of 65°C and a stirring rate of 200 r / min for 6 h to obtain the general white paste for anti-settling paint;

[0058] The composite white pigment is prepared by the following steps:

[0059] The 10 g nano-titanium dioxide, 0.15 g sodium hexametaphosphate and 30 mL deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, and then ultrasonic treatment is carried out under the condition of 300 W ultrasonic power for 15 min. Then, the reaction is stirred at 65℃ and a stirring speed of 350 r / min for 20 min. Then, the pH value is adjusted to 9.5 by using a 25% sodium hydroxide solution. Then, 20 mL of a 0.1 mol / L sodium silicate solution is added and the reaction is continuously stirred for 1.5 h. Then, 20 mL of a 0.1 mol / L cerium sulfate solution is added and the reaction is continuously stirred for 3 h. After the reaction is completed, the reaction product is cooled to room temperature, and then centrifuged. The precipitate is washed with distilled water for 3 times, and then placed in a vacuum drying oven and dried at 85℃ for 10 h. Then, the product is crushed to obtain the composite white pigment.

[0060] The settling inhibitor is prepared by the following steps:

[0061] In step s1, 10 mmol of tetraphenylmethane and 22 mL of a 97.5% fuming nitric acid solution are added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a constant pressure dropping funnel. Nitrogen is introduced for protection. The reaction is stirred at -30℃ and a stirring speed of 350 r / min for 1.5 h. Then, 20 mL of an acetic anhydride solution dissolved in acetic acid at a volume ratio of 1:2 is added dropwise while stirring. The dropping speed is controlled to be 2 drops / s. After the addition is completed, 50 mL of acetic acid is added and the reaction is continuously stirred at 30℃ for 5 h. After the reaction is completed, the reaction product is vacuum filtered. Then, the filter cake is washed with anhydrous ethanol for 5 times. Then, the product is placed in a vacuum drying oven and dried at 65℃ for 3 h to obtain intermediate 1.

[0062] In step s2, 1 g of intermediate 1, 0.25 g of 5% palladium-carbon and 55 mL of anhydrous ethanol are added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a reflux condenser and a constant pressure dropping funnel. Nitrogen is introduced for protection. The reaction is stirred at 30℃ and a stirring speed of 350 r / min for 20 min. Then, 8 mL of an 85% hydrazine hydrate solution is added dropwise while stirring. The dropping speed is controlled to be 2 drops / s. After the addition is completed, the reaction is continuously stirred at reflux for 20 h. After the reaction is completed, the reaction product is cooled to room temperature. Then, the solvent is removed by rotary evaporation. Then, the product is eluted with a mixed solvent prepared by mixing anhydrous ethanol and dichloromethane at a volume ratio of 1:9. Then, the product is placed in a vacuum drying oven and dried at 45℃ for 6 h to obtain intermediate 2.

[0063] Step s3: 10 mmol of intermediate 2, 50 mmol of (3-chloropropyl)triethoxysilane, 55 mmol of anhydrous potassium carbonate, 6 mmol of potassium iodide and 150 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer and a nitrogen inlet tube, protected by nitrogen, stirred at a temperature of 0°C and a stirring rate of 350 r / min for 50 min, then the temperature was raised to 85°C and the stirring was continued for 30 h. After the reaction was completed, the reaction product was cooled to room temperature, then filtered under vacuum, the filtrate was rotary evaporated to remove the solvent, then washed with anhydrous ethanol for 5 times, then placed in a vacuum drying oven, dried at a temperature of 40°C for 10 h to obtain the sedimentation inhibitor.

[0064] Comparative Example 1

[0065] The present comparative example is a preparation method of a sedimentation-preventable general white paste for paint, comprising the following steps:

[0066] Step one: 55 parts of nano-titanium dioxide, 46 parts of acrylic resin, 9 parts of butyl acetate, 5 parts of diethylene glycol monobutyl ether, 2.5 parts of defoaming agent and 15 parts of ethanol solution were weighed according to weight parts, and prepared for use. The defoaming agent is BYK088 silicone defoaming agent, and the volume fraction of the ethanol solution is 95%;

[0067] Step two: the nano-titanium dioxide, acrylic resin, butyl acetate, diethylene glycol monobutyl ether, defoaming agent and ethanol solution were added to a mixer, then stirred and mixed at a temperature of 30°C and a stirring rate of 350 r / min for 30 min, then placed in a grinder, and ground at a temperature of 65°C and a stirring rate of 200 r / min for 6 h to obtain the sedimentation-preventable general white paste for paint.

[0068] Comparative Example 2

[0069] The present comparative example is a preparation method of a sedimentation-preventable general white paste for paint, comprising the following steps:

[0070] Step one: 55 parts of nano-titanium dioxide, 46 parts of acrylic resin, 9 parts of butyl acetate, 5 parts of diethylene glycol monobutyl ether, 2.5 parts of defoaming agent and 15 parts of ethanol solution were weighed according to weight parts, and prepared for use. The defoaming agent is BYK088 silicone defoaming agent, and the volume fraction of the ethanol solution is 95%;

[0071] Step two: the composite white pigment, acrylic resin, butyl acetate, diethylene glycol monobutyl ether, defoaming agent and ethanol solution were added into the mixer, then stirred and mixed at 30℃ and 350r / min for 30min, and then placed in the grinder, and grinded at 65℃ and 200r / min for 6h to obtain the anti-settling general white paste for paint;

[0072] The composite white pigment was prepared by the following steps:

[0073] 10g of nano-titanium dioxide, 0.15g of sodium hexametaphosphate and 30mL of deionized water were added into a three-necked flask equipped with a stirrer and a thermometer, and ultrasonic treated at 300W for 15min, then stirred at 65℃ and 350r / min for 20min, then adjusted to pH 9.5 with 25% sodium hydroxide solution, then added 20mL of 0.1mol / L sodium silicate solution and continued to stir for 1.5h, then added 20mL of 0.1mol / L cerium sulfate solution and continued to stir for 3h, then cooled the reaction product to room temperature, then centrifuged, washed the precipitate with distilled water for 3 times, then placed in a vacuum drying oven at 85℃ for 10h, then crushed to obtain the composite white pigment.

[0074] Comparative example 3:

[0075] The present comparative example is a preparation method of an anti-settling general white paste for paint, comprising the following steps:

[0076] Step one: 55 parts of nano-titanium dioxide, 9.5 parts of a settlement inhibitor, 46 parts of acrylic resin, 9 parts of butyl acetate, 5 parts of diethylene glycol monobutyl ether, 2.5 parts of a defoaming agent and 15 parts of an ethanol solution were weighed according to the weight parts, and prepared for use; the defoaming agent was BYK088 silicone defoaming agent, and the volume fraction of the ethanol solution was 95%;

[0077] Step two: the nano-titanium dioxide, the settlement inhibitor, the acrylic resin, the butyl acetate, the diethylene glycol monobutyl ether, the defoaming agent and the ethanol solution were added into the mixer, then stirred and mixed at 30℃ and 350r / min for 30min, and then placed in the grinder, and grinded at 65℃ and 200r / min for 6h to obtain the anti-settling general white paste for paint;

[0078] The settlement inhibitor was prepared by the following steps:

[0079] Step s1: 10 mmol of tetraphenylmethane, 22 mL of 97.5% fuming nitric acid were added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a constant pressure dropping funnel, and stirred at a temperature of -30°C and a stirring rate of 350 r / min for 1.5 h under nitrogen protection, then 20 mL of acetic anhydride solution dissolved in acetic acid at a volume ratio of 1:2 was added dropwise under stirring at a dropping rate of 2 drops / s, after the addition was completed, 50 mL of acetic acid was added and the reaction was continued to be stirred at a temperature of 30°C for 5 h, after the reaction was completed, the reaction product was vacuum filtered, then the filter cake was washed with anhydrous ethanol for 5 times, and then placed in a vacuum drying oven for drying at a temperature of 65°C for 3 h to obtain intermediate 1;

[0080] Step s2: 1 g of intermediate 1, 0.25 g of 5% palladium-carbon and 55 mL of anhydrous ethanol were added into a three-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a reflux condenser and a constant pressure dropping funnel, and stirred at a temperature of 30°C and a stirring rate of 350 r / min for 20 min under nitrogen protection, then 8 mL of 85% hydrazine hydrate solution was added dropwise under stirring at a dropping rate of 2 drops / s, after the addition was completed, the reaction was continued to be stirred at reflux for 20 h, after the reaction was completed, the reaction product was cooled to room temperature, then the solvent was removed by rotary evaporation, then eluted with a mixed solvent of anhydrous ethanol and dichloromethane at a volume ratio of 1:9, and then placed in a vacuum drying oven for drying at a temperature of 45°C for 6 h to obtain intermediate 2;

[0081] Step s3: 10 mmol of intermediate 2, 50 mmol of (3-chloropropyl)triethoxysilane, 55 mmol of anhydrous potassium carbonate, 6 mmol of potassium iodide and 150 mL of anhydrous toluene were added into a three-necked flask equipped with a stirrer, a thermometer and a nitrogen inlet tube, and stirred at a temperature of 0°C and a stirring rate of 350 r / min for 50 min under nitrogen protection, then the reaction was continued to be stirred at a temperature of 85°C for 30 h, after the reaction was completed, the reaction product was cooled to room temperature, then the filtrate was vacuum filtered and the solvent was removed by rotary evaporation, then washed with anhydrous ethanol for 5 times, and then placed in a vacuum drying oven for drying at a temperature of 40°C for 10 h to obtain the sedimentation inhibitor.

[0082] The anti-settling paint universal white paste of examples 1-3 and comparative examples 1-3 was detected, and the detection results are as follows:

[0083]

[0084] According to the data in the above table, it can be seen from the comparison between Examples 1-3 and Comparative Examples 1-3 that the use of the settlement inhibitor can greatly improve the anti-settling effect of the general white paste for coatings, and the use of the composite white pigment instead of nano-titanium dioxide can greatly improve the coloring effect and hiding power of the general white paste for coatings.

[0085] The nano-titanium dioxide is subjected to scanning electron microscope analysis, as shown in Figure 2 The composite white pigment is subjected to scanning electron microscope analysis, as shown in Figure 3

[0086] The Figure 2 , Figure 3 are compared, it can be seen that the surface of the composite white pigment is smooth compared with the nano-titanium dioxide particles, and because it is covered with a uniform film layer, the film layer is a SiO2 / CeO2 composite layer, after the nano-titanium dioxide particles are wrapped with SiO2 / CeO2, a dense film layer is formed, which improves the dispersibility of titanium dioxide, and SiO2 / CeO2 also has excellent ultraviolet shielding performance, which improves the coloring power and hiding power, and at the same time reduces the active sites on the surface of titanium dioxide, achieves the purpose of inhibiting photocatalytic activity, avoids the degradation of the white paste due to the generation of free radicals caused by photocatalysis after the white paste is used in coatings, and causes the material to deteriorate.

[0087] In the description of the present specification, the description referring to the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description 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.

[0088] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.​

Claims

1. A universal white slurry for coatings that can prevent sedimentation, characterized in that: It comprises the following components in parts by weight: 35-55 parts of composite white pigment, 3.5-9.5 parts of sedimentation inhibitor, 32-46 parts of acrylic resin, 5-9 parts of butyl acetate, 3-5 parts of diethylene glycol monobutyl ether, 1.5-2.5 parts of defoaming agent and 10-15 parts of ethanol solution; The defoamer is BYK088 organosilicon defoamer, and the volume fraction of the ethanol solution is 85-95%; Wherein, the composite white pigment is prepared by the following steps: Nano-titanium dioxide, sodium hexametaphosphate and deionized water are ultrasonically treated, and then stirred to react. Then, the pH is adjusted with a sodium hydroxide solution, and then a sodium silicate solution and a cerium sulfate solution are sequentially added and stirred to react. After the reaction is completed, the reaction product is cooled, centrifuged, and the precipitate is washed, dried, and then crushed to obtain a composite white pigment. The sedimentation inhibitor is prepared by the following steps: Step s1: Tetraphenylmethane and fuming nitric acid are stirred for reaction, and then acetic anhydride solution is added dropwise with stirring. After the addition is complete, acetic acid is added and the stirring reaction is continued. After the reaction is completed, the reaction product is vacuum filtered, and the filter cake is washed and dried to obtain Intermediate 1; Step s2: stirring the intermediate 1, 5% palladium on carbon, and anhydrous ethanol, then adding the hydrazine hydrate solution dropwise while stirring, and continuing to stir the reaction after the addition is complete. After the reaction is completed, the reaction product is cooled, then rotary evaporated, eluted with a mixed solvent, and then dried to obtain the intermediate 2; Step s3: The intermediate 2, (3-chloropropyl)triethoxysilane, anhydrous potassium carbonate, potassium iodide, and anhydrous toluene are stirred for reaction. After the reaction is completed, the reaction product is cooled and then vacuum filtered. The filtrate is rotary evaporated, washed, and dried to obtain a sedimentation inhibitor.

2. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: The dosage ratio of the nano-titanium dioxide, sodium hexametaphosphate, deionized water, sodium silicate solution and cerium sulfate solution is 10g: 0.1-0.15g: 25-30mL: 15-20mL: 15-20mL.

3. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: The mass fraction of the sodium hydroxide solution is 20-25%, the molar concentration of the sodium silicate solution is 0.1 mol / L, and the molar concentration of the cerium sulfate solution is 0.1 mol / L.

4. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: The usage ratio of the tetraphenylmethane, fuming nitric acid, acetic anhydride solution and acetic acid in step s1 is 10 mmol:18-22 mL:15-20 mL:40-50 mL.

5. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: The mass fraction of the fuming nitric acid in step s1 is 97.5%, and the acetic anhydride solution is a solution formed by dissolving acetic anhydride in acetic acid at a volume ratio of 1:1.8-2.

6. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: The usage ratio of the intermediate 1, 5% palladium carbon, anhydrous ethanol and hydrazine hydrate solution in step s2 is 1 g: 0.2-0.25 g: 50-55 mL: 5-8 mL.

7. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: The mass fraction of the hydrazine hydrate solution in step s2 is 85%, and the mixed solvent is a mixture of anhydrous ethanol and dichloromethane in a volume ratio of 1:

9.

8. The universal white slurry for coatings capable of preventing sedimentation according to claim 1, characterized in that: In step s3, the usage ratio of the intermediate 2, (3-chloropropyl)triethoxysilane, anhydrous potassium carbonate, potassium iodide and anhydrous toluene is 10 mmol: 45-50 mmol: 50-55 mmol: 5-6 mmol: 120-150 mL.

9. A method for preparing a universal white slurry for coatings capable of preventing sedimentation according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Weigh 35-55 parts of composite white pigment, 3.5-9.5 parts of sedimentation inhibitor, 32-46 parts of acrylic resin, 5-9 parts of butyl acetate, 3-5 parts of diethylene glycol monobutyl ether, 1.5-2.5 parts of defoaming agent and 10-15 parts of ethanol solution according to weight, and set aside; Step 2: Add the composite white pigment, sedimentation inhibitor, acrylic resin, butyl acetate, diethylene glycol monobutyl ether, defoaming agent and ethanol solution into a mixer, then stir and mix for 20-30 minutes at a temperature of 25-30°C and a stirring rate of 300-350r / min, then place in a grinder and grind for 3-6 hours at a temperature of 60-65°C and a stirring rate of 150-200r / min to obtain the universal white slurry for anti-settling coating.

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