A high-gloss general-purpose aqueous kaolin filler slurry, its preparation method and application

Abstract

The present invention discloses a high-gloss general-purpose water-based kaolin filler slurry, its preparation method and application, which relate to the field of coatings. The kaolin filler slurry comprises kaolin powder, a dispersant, a coating resin, a composite anti-settling agent, a solvent, an antifoaming agent, and a wetting agent; the dispersant is BYK194, NOPCALL-5180 and SN-1776, and the coating resin is THYON PH729, THYON SRT3069, THYON SR675 and THYON SR705. The filler slurry of the present application utilizes the mutual anchoring of the active groups of the dispersant and the surface functional groups of kaolin to reduce the viscosity and particle size. The solvated chain segments in the dispersant extend in the coating resin to form a polymer chain segment barrier layer, preventing the polymerization and agglomeration between powder particles, so that the slurry has small particle size and narrow particle size distribution. Adding a large amount of it to the coating does not reduce the gloss, and improves the dry film hiding power of the paint film, reducing the usage of titanium dioxide, emulsion and water in the water-based paint.

Description

Technical Field

[0001] The present invention relates to the field of coatings, and particularly to a high-gloss general-purpose aqueous kaolin filler slurry, a preparation method thereof, and an application thereof. Background Art

[0002] The water in waterborne metal anti-corrosion coatings requires more time to evaporate and dry, and is sensitive to the construction environment. The curing process is greatly affected by temperature and humidity, and unsuitable environmental conditions may be unfavorable for the formation of the paint film. During paint construction, the wet film contains a large amount of solvents or water, and these liquid components help to disperse the pigment particles and reduce the aggregation between the pigments, enabling the paint to cover the underlying substrate more effectively. As the paint dries, the solvents or water gradually evaporate, and the pigment particles rearrange and may aggregate, resulting in a decrease in hiding power. Therefore, the hiding power of the dry film is usually lower than that of the wet film. The reason is that the refractive index difference between the pigments in the paint and the paint matrix (such as water or resin) affects the hiding power. When the paint is wet, the pigment particles are surrounded by water, while after drying, the pigment particles are surrounded by resin or air. Since the refractive indices of water and resin or air are different, this will affect the way light passes through the paint film, thereby affecting the hiding power. Especially when applying pure white or light white paint, the color or defects of the primer are invisible when spraying the wet film of the topcoat, but the color or defects of the primer appear after the topcoat film dries.

[0003] To ensure that the topcoat has good dry hiding power to cover the defects or color of the underlying primer, a large amount of titanium white paste is often added to the topcoat or a thicker topcoat is sprayed, resulting in an increase in cost. The topcoat of waterborne metal anti-corrosion coatings requires high protective performance and decorative performance, and mostly has high requirements for gloss. Therefore, the pigment-volume concentration is generally very low, and only a small amount of filler powder is added to the formulation, mostly resin, solvent, and water.

[0004] Since adding more resin and solvent to waterborne metal anti-corrosion coatings will increase the product cost, while adding more water will slow down the evaporation of water and additionally increase the dosage of thickeners. Therefore, it is of great significance to develop a general-purpose filler slurry with strong versatility, better dispersion effect, low impact on the gloss of the paint film, and significantly improved dry hiding power of the paint film. Summary of the Invention

[0005] The present invention provides a high-gloss general-purpose aqueous kaolin filler slurry, a preparation method thereof, and an application thereof, to provide a filler slurry with strong versatility, small particle size and uniform dispersion, low impact on the gloss of the paint film, effectively improve the dry film hiding power of the paint film, reduce the addition amount of titanium dioxide, resin emulsion and water, and reduce the cost.

[0006] To solve the above technical problems, one of the objectives of the present invention is to provide a high-gloss general-purpose aqueous kaolin filler slurry, which comprises the following components in parts by weight:

[0007] Kaolin powder: 50 parts - 60 parts;

[0008] Dispersant: 1 part - 3 parts;

[0009] Coating resin: 1 part - 4 parts;

[0010] Compound anti-settling agent: 0 part - 3 parts;

[0011] Solvent: 1 part - 5 parts;

[0012] Defoamer A: 0.3 part - 1 part;

[0013] Wetting agent A: 0.2 part - 0.5 part;

[0014] Among them, the dispersant includes BYK194, NOPCALL-5180 and SN-1776 with a mass ratio of (2 - 6):(2 - 6):(2 - 6), and the coating resin includes THYON PH729, THYON SRT3069, THYON SR675 and THYON SR705 with a mass ratio of (2 - 8):(2 - 8):(2 - 8):(2 - 8).

[0015] By adopting the above scheme, the viscosity of the high-concentration kaolin slurry is mainly related to its internal structure and the interaction between particles. At high concentrations, the contact between kaolin particles becomes more frequent, and the interaction force between particles increases, resulting in an increase in the viscosity of the fluid. The shape and surface characteristics of kaolin particles also affect their dispersion state and interaction in water. Irregular particle shapes and rough surfaces may increase the friction between particles. In the kaolin filler slurry of this application, the dispersant is a compound of BYK194, NOPCALL-5180 and SN-1776. The multiple active groups with positive and negative charges of the dispersant are adsorbed on the surface of fine kaolin particles, and hydrogen bonds are formed with functional groups such as hydroxyl groups (-Si(Al)-OH), silicon-oxygen tetrahedrons (-Si-O-Al-), and aluminum-oxygen octahedrons (-Si(Al)-O) on the kaolin surface, thus generating an anchoring effect to activate the powder. The dispersant can form a steric hindrance effect, effectively reducing the irregular shape and rough surface of the particles, and then effectively reducing the viscosity of the kaolin filler slurry under high shear force. Moreover, the particle size of the slurry is small, which helps to disperse in the subsequent water-based emulsion.

[0016] In addition, the coating resin added in this application is a modified acrylic resin. The dispersant has segments with numerous hydrogen bond donors and acceptors. The solvated segments in the dispersant extend into the coating resin, forming a polymer chain segment barrier layer with a certain thickness to prevent the polymerization and agglomeration of powder particles, making the particle size of kaolin smaller. The particle size distribution of the kaolin slurry is narrow. When a large amount is added to the coating, it will not reduce the gloss, and at the same time, it can improve the dry film hiding power of the paint film and reduce the usage amount of titanium dioxide.

[0017] As a preferred solution, the composite anti-settling agent comprises RHEOBYK-420, BYK R 605, RHEOBYK-H7625VF and AEROSIL 200 with a mass ratio of (1-4):(1-4):(1-4):(1-4).

[0018] By adopting the above solution, the composite anti-settling agent of the present application forms micelles in the aqueous phase system. The hydrophobic ends are adsorbed together with the hydrophobic structures in the dispersant and the coating resin, synergistically solving the problems of difficult anti-settling and poor storage stability, forming a three-dimensional anti-settling network structure. The hydrophilic ends of the composite anti-settling agent thicken through hydrogen bond hydration, adjusting the viscosity of the system, improving the stability of the filler slurry system, and being able to withstand long-term and high-temperature storage.

[0019] As a preferred solution, the solvent is at least one of ethanol, propylene glycol, ethylene glycol monobutyl ether, and diethylene glycol monobutyl ether; the defoaming agent A is at least one of BYK022, BYK028, TEGO901W, TEGO902W, NOPTAM-398, NOPTAM-1311, and SN-6024, and the wetting agent A is at least one of BYK-346, BYK-345, TEGO270, TEGO4100, SURFYNOL465, and SURFYNOL104E.

[0020] To solve the above technical problems, the second object of the present invention provides a preparation method of a high-gloss general-purpose aqueous kaolin filler slurry, comprising the following steps:

[0021] (1) Add the water, solvent, dispersant, defoaming agent, and wetting agent in sequence and mix them evenly. After adding the kaolin powder and dispersing it evenly, grind it with a horizontal mill until the particle size of the slurry reaches 0.8um≥95% to obtain a fine kaolin raw material slurry;

[0022] (2) Add the coating resin and the composite anti-settling agent during the grinding of the fine kaolin raw material slurry, and mix them evenly to obtain a kaolin filler slurry.

[0023] As a preferred solution, in step (1), the grinding medium balls include medium balls with diameters of 3mm, 1.5mm, and 0.8mm with a mass ratio of 1:2:2. The grinding speed is 500-800 revolutions per minute, the grinding time is 1-3h, and the grinding temperature is less than 70°C.

[0024] To solve the above technical problems, the third object of the present invention provides an application of a high-gloss general-purpose aqueous kaolin filler slurry in the field of preparing aqueous emulsion coatings.

[0025] To solve the above technical problems, a fourth object of the present invention is to provide an aqueous emulsion paint, which includes a high-gloss general-purpose aqueous kaolin filler slurry with a mass fraction of 5wt%-20wt%.

[0026] As a preferred embodiment, it includes the following components in parts by weight:

[0027] Aqueous emulsion: 50 parts - 70 parts;

[0028] Defoamer B: 0.3 parts - 0.8 parts;

[0029] Wetting agent B: 0.2 parts - 0.6 parts;

[0030] Leveling agent: 0.1 parts - 0.3 parts;

[0031] Film-forming aid: 2 parts - 6 parts;

[0032] Aqueous titanium white paste: 5 parts - 15 parts;

[0033] High-gloss general-purpose aqueous kaolin filler slurry: 10 parts - 20 parts;

[0034] Water: 10 parts - 20 parts.

[0035] By adopting the above solution, the kaolin filler slurry in the present application is added to the aqueous emulsion paint. Since the kaolin particles have a narrow particle size distribution, small particle size, and low viscosity, adding a large amount does not affect the gloss of the paint film. At the same time, the kaolin filler slurry can also improve the dry film hiding power of the paint, reduce the addition amount of titanium white paste, and reduce costs. The higher concentration addition of the kaolin filler slurry can also reduce the content ratio of the aqueous emulsion and water in the system, and improve the volatilization rate of the moisture in the paint film; and the particle size of the kaolin filler slurry is stable, can withstand a high-temperature environment and long-term storage, and will not stratify, which can improve the storage stability of the paint.

[0036] As a preferred embodiment, the film-forming aid is C12 alcohol ester.

[0037] As a preferred embodiment, the aqueous emulsion is an aqueous acrylic emulsion.

[0038] As a preferred embodiment, the defoamer B is at least one of BYK022, BYK028, TEGO901W, TEGO902W, NOPTAM-398, NOPTAM-1311, SN-6024, and the wetting agent B is at least one of BYK-346, BYK-345, TEGO270, TEGO4100, SURFYNOL465, SURFYNOL104E.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. In the kaolin filler slurry of this application, the dispersant is a compound of BYK194, NOPCALL-5180, and SN-1776. Multiple active groups with positive and negative charges in the dispersant are adsorbed on the surface of fine kaolin particles during the grinding process, and form hydrogen bonds with functional groups such as hydroxyl groups, silicon-oxygen tetrahedrons, and aluminum-oxygen octahedrons on the kaolin surface, thus achieving an anchoring effect, activating the powder, effectively reducing the irregular shape and rough surface of the particles, and then effectively reducing the viscosity of the kaolin filler slurry under high shear force. Moreover, the particle size of the slurry is small, which helps to disperse in the subsequent aqueous emulsion without affecting the gloss of the aqueous emulsion.

[0041] 2. The coated resin added in this application is a modified acrylic resin. The dispersant has segments with numerous hydrogen bond donors and acceptors. The solvated segments in the dispersant extend into the coated resin, forming a polymer segment barrier layer with a certain thickness, preventing the polymerization and agglomeration of powder particles, making the particle size of kaolin smaller, and the particle size of the kaolin slurry showing a narrow particle size distribution. When a large amount is added to the coating, it will not reduce the gloss, and at the same time, it improves the dry film hiding power of the paint film and reduces the usage amount of titanium dioxide.

[0042] 3. The composite anti-settling agent in this application forms micelles in the aqueous phase system. The hydrophobic ends are adsorbed together with the hydrophobic structures in the dispersant and the coated resin, forming a three-dimensional anti-settling network structure, which synergistically solves the problems of difficult anti-settling and poor storage stability, can improve the stability of the filler slurry system, can withstand long-term and high-temperature storage, and the effective solid concentration of the aqueous kaolin filler slurry is higher, with better cost performance. Specific Embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0044] Table 1 - Sources of raw materials used in the examples and comparative examples of this application

[0045]

[0046]

[0047] Example 1

[0048] A high-gloss general-purpose aqueous kaolin filler slurry, comprising 3 wt% propylene glycol solvent, 0.5 wt% TEGO 902W defoamer, 0.3 wt% BYK 346 wetting agent, 50 wt% calcined kaolin powder, 2 wt% coating resin, 1.2 wt% dispersant, 1 wt% composite anti-settling agent, and the balance deionized water. The coating resin includes 0.8 wt% of THYON PH729, 0.6 wt% of THYON SRT3069, 0.4 wt% of THYON SR675, and 0.2 wt% of THYON SR705 based on the mass fraction of the filler slurry. The composite anti-settling agent includes 0.2 wt% of RHEOBYK-420, 0.1 wt% of BYK R 605, 0.4 wt% of RHEOBYK-H7625VF, and 0.3 wt% of AEROSIL 200 based on the mass fraction of the filler slurry. The dispersant includes 0.4 wt% of BYK194, 0.6 wt% of NOPCALL-5180, and 0.2 wt% of SN-1776 based on the mass fraction of the filler slurry.

[0049] The preparation method of the above-mentioned high-gloss general-purpose aqueous kaolin filler slurry includes the following steps:

[0050] (1) Add deionized water, solvent, dispersant, defoamer, and wetting agent into a stirring kettle in sequence and mix evenly. After adding kaolin powder, disperse at a high speed of 1000 revolutions per minute for 30 minutes; then grind with a horizontal mill. The grinding medium balls include medium balls with diameters of 3 mm, 1.5 mm, and 0.8 mm in a mass ratio of 1:2:2. The grinding speed is 600 revolutions per minute, the grinding time is 2 h, and the grinding temperature is less than 70 °C. Finally, the particle size of the kaolin slurry reaches 0.8 um ≥ 95%, obtaining a fine kaolin raw material slurry;

[0051] (2) After the particle size meets the standard, add the coating resin and the composite anti-settling agent during the grinding of the fine kaolin raw material slurry and mix evenly to obtain the kaolin filler slurry.

[0052] Example 2

[0053] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that the dispersant includes 0.2 wt% of BYK194, 0.4 wt% of NOPCALL-5180, and 0.6 wt% of SN-1776 based on the filler slurry.

[0054] Example 3

[0055] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that the dispersant includes 0.6 wt% of BYK194, 0.2 wt% of NOPCALL-5180, and 0.4 wt% of SN-1776 in the filler slurry.

[0056] Example 4

[0057] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that the dispersant includes 0.6 wt% of BYK194, 0.4 wt% of NOPCALL-5180, and 0.2 wt% of SN-1776 in the filler slurry.

[0058] Comparative Example 1

[0059] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that the dispersant includes 1.2 wt% of SN-5040 in the filler slurry.

[0060] Comparative Example 2

[0061] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that the dispersant includes 1.2 wt% of TEGO760W in the filler slurry.

[0062] Comparative Example 3

[0063] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that the dispersant includes 1.2 wt% of NOPCALL-5180 in the filler slurry.

[0064] The stickiness and viscosity of the kaolin fine raw material slurry before grinding and the particle size characteristics of the kaolin filler slurry in Examples 1-4 and Comparative Examples 1-3 were detected and recorded. The kaolin filler slurries in Examples 1-4 and Comparative Examples 1-3 were respectively applied to prepare test samples for aqueous emulsions. The blank group samples used an aqueous emulsion to replace the kaolin filler slurry in equal amounts and were tested, including the following operating steps:

[0065] (1) Before grinding the kaolin fine raw material slurry, conduct a stickiness test on the slurry. Use one end of a glass rod to press against the inner wall of the container and stir quickly in the same direction to feel the resistance during the process. At the same time, conduct a viscosity test in accordance with GB / T 9269-2009 "Determination of coating viscosity - Stormer viscometer method", and conduct a particle size test on the kaolin filler slurry;

[0066] (2) Prepare a waterborne emulsion paint. Take 60 g of the waterborne acrylic emulsion of Wanhua Chemical model 0626, add 0.5 g of the defoamer of model TEGO902W, 0.3 g of the wetting agent of model BYK346, 0.2 g of the leveling agent of model TEGO450, 4 g of the C12 alcohol ester film-forming aid, 10 g of the Guangdong Kedi W1006-SI waterborne titanium dioxide slurry and 10 g of water. Then add 15 g of the kaolin filler slurry and mix evenly to prepare the waterborne emulsion paint;

[0067] (3) Film the waterborne emulsion paint on a glass plate with a film thickness of 100 μm;

[0068] (3) Conduct gloss and dry film reflectivity tests on the film sample. The glossiness test refers to GB / T 9754-2007 "Determination of 20°, 60° and 85° specular gloss of paint films of paints and varnishes - Paints not containing metallic pigments", and the reflectivity test method refers to GB / T 23981.1-2019 "Determination of hiding power of paints and varnishes - Part 1: Determination of contrast ratio of white and light-colored paints". The test results are shown in Table 2 below.

[0069] Table 2 - Performance test results of waterborne emulsions prepared from kaolin fillers in Examples 1-4 and Comparative Examples 1-3 of this application

[0070]

[0071]

[0072] As shown in Table 2, compared with the blank group without kaolin filler slurry, in Examples 1-4 of the present application, the dispersants in the kaolin filler slurry are compounded and added in proportion by BYK194, NOPCALL-5180 and SN-1776. The shape and surface characteristics of kaolin particles also affect their dispersion state and interaction in water. In the present application, various active groups with positive and negative charges of the dispersant are adsorbed on the surface of fine kaolin particles, and hydrogen bonds are formed with functional groups such as hydroxyl groups (-Si(Al)-OH), silicon-oxygen tetrahedrons (-Si-O-Al-), and aluminum-oxygen octahedrons (-Si(Al)-O) on the kaolin surface during the grinding process, thus anchoring occurs, activating the powder. The dispersant can form a steric hindrance effect, effectively reducing the irregular shape and rough surface of the particles, and further effectively reducing the viscosity of the kaolin filler slurry under high shear force, which is beneficial to reducing the particle size of kaolin and dispersing it evenly in the water-based emulsion, improving the dry hiding power of the paint film, and having a low impact on the gloss of the paint film; at the same time, compared with the single dispersant component in the kaolin filler slurry of Comparative Examples 1-3, the film made by adding the compounded dispersant in Examples 1-4 of the present application has a higher gloss and dry film reflectivity.

[0073] Example 5

[0074] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 1, except that the mass fraction of kaolin powder in the filler slurry is 60wt%.

[0075] Example 6

[0076] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 2, except that the mass fraction of kaolin powder in the filler slurry is 60wt%.

[0077] Example 7

[0078] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 3, except that the mass fraction of kaolin powder in the filler slurry is 60wt%.

[0079] Example 8

[0080] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 4, except that the mass fraction of kaolin powder in the filler slurry is 60wt%.

[0081] Comparative Example 4

[0082] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 5. The difference is that the dispersant includes SN-5040 accounting for 1.2 wt% of the filler slurry.

[0083] Comparative Example 5

[0084] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 5. The difference is that the dispersant includes TEGO760W accounting for 1.2 wt% of the filler slurry.

[0085] Comparative Example 6

[0086] A high-gloss general-purpose water-based kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those in Example 5. The difference is that the dispersant includes NOPCALL-5180 accounting for 1.2 wt% of the filler slurry.

[0087] The stickiness and viscosity of the fine kaolin raw material slurry before grinding and the particle size characteristics of the kaolin filler slurry in Examples 5-8 and Comparative Examples 4-6 above were detected and recorded. The kaolin filler slurries in Examples 5-8 and Comparative Examples 4-6 were respectively applied to prepare test samples for water-based emulsions, and the film gloss and dry film reflectivity were tested. The operation steps for preparing the water-based emulsion coatings and film samples were the same as those described above and will not be elaborated here. Among them, the blank group samples used water-based emulsion to replace the kaolin filler slurry equivalently. The test results are shown in Table 3 below.

[0088] Table 3 - Performance test results of water-based emulsions prepared with kaolin fillers in Examples 5-8 and Comparative Examples 4-6 of this application

[0089]

[0090] As shown in Table 3, the increase in the kaolin concentration in the filler slurries of Comparative Examples 4-5 led to more frequent contact between particles, enhanced mutual interaction, increased viscosity of the filler slurry, strong stickiness, and difficulty in grinding treatment. The uneven distribution and large particle size of kaolin particles resulted in a serious decrease in the gloss of the finally prepared film. Although the filler slurries in Examples 5-8 of this application had a certain degree of viscosity increase, the stickiness was relatively slight and did not affect grinding. The dry hiding power of the prepared film was improved, and the gloss was higher than that in Comparative Examples 4-6 and could be maintained at a relatively high level.

[0091] Example 9

[0092] A high-gloss general-purpose waterborne kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are all the same as those in Example 7. The difference lies in that the coating resin includes 0.2 wt% of THYON PH729, 0.4 wt% of THYON SRT3069, 0.6 wt% of THYON SR675, and 0.8 wt% of THYON SR705 based on the mass fraction of the filler slurry.

[0093] Example 10

[0094] A high-gloss general-purpose waterborne kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are all the same as those in Example 7. The difference lies in that the coating resin includes 0.4 wt% of THYON PH729, 0.6 wt% of THYON SRT3069, 0.2 wt% of THYON SR675, and 0.8 wt% of THYON SR705 based on the mass fraction of the filler slurry.

[0095] Example 11

[0096] A high-gloss general-purpose waterborne kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are all the same as those in Example 7. The difference lies in that the coating resin includes 0.6 wt% of THYON PH729, 0.2 wt% of THYON SRT3069, 0.8 wt% of THYON SR675, and 0.4 wt% of THYON SR705 based on the mass fraction of the filler slurry.

[0097] Comparative Example 7

[0098] A high-gloss general-purpose waterborne kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are all the same as those in Example 7. The difference lies in that the coating resin includes 2 wt% of Xinghengtai 518H based on the mass fraction of the filler slurry.

[0099] Comparative Example 8

[0100] A high-gloss general-purpose waterborne kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are all the same as those in Example 7. The difference lies in that the coating resin includes 2 wt% of Lihua Yi 702 based on the mass fraction of the filler slurry.

[0101] Comparative Example 9

[0102] A high-gloss general-purpose waterborne kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are all the same as those in Example 7. The difference lies in that the coating resin includes 2 wt% of THYON SR675 based on the mass fraction of the filler slurry.

[0103] The kaolin filler slurries of Examples 7, 9 - 11 and Comparative Examples 7 - 9 were respectively applied to prepare test samples for the aqueous emulsion, and the film gloss and dry film reflectance were tested. The preparation operation steps of the aqueous emulsion paint and the film samples were the same as those described above and will not be elaborated here. Among them, the blank group samples used the aqueous emulsion to replace the kaolin filler slurry equivalently. Compared with the film samples of Example 10 in the experimental group, the difference was that 2 g of the aqueous titanium white slurry was replaced with water. The test results are shown in Table 4 below.

[0104] Meanwhile, the film samples of the blank group, the experimental group and Example 10 were subjected to hardness (pencil method), adhesion (cross - hatch method) and solid content tests. The solid content test referred to the standard of GB / T 1725 - 2007 "Determination of non - volatile content of paints, varnishes and plastics". The solid content test conditions were 105 °C / 1 h. The test results are shown in Table 4 below.

[0105] Table 4 - Performance test results of the aqueous emulsions prepared with the kaolin fillers of Examples 7, 9 - 11 and Comparative Examples 7 - 9 of the present application

[0106] As shown in Table 4, compared with the single - coated resin of Comparative Examples 7 - 9, the coated resin added in Examples 7, 9 - 11 of the present application was a modified acrylic resin. At the same time, the added dispersant had segments with numerous hydrogen - bond donors and acceptors. The solvated segments of the dispersant extended in the coated resin, forming a polymer - chain - segment barrier layer with a certain thickness, preventing the polymerization and agglomeration between powder particles, making the kaolin particle size smaller, and improving the gloss of the prepared aqueous paint film.

[0107] Example 12

[0108] A high - gloss general - purpose aqueous kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those of Example 10. The difference is that the composite anti - settling agent includes 0.1 wt% of RHEOBYK - 420, 0.2 wt% of BYK R 605, 0.3 wt% of RHEOBYK - H7625VF, and 0.4 wt% of AEROSIL 200 based on the mass of the kaolin filler slurry.

[0109] Example 13

[0110] A high - gloss general - purpose aqueous kaolin filler slurry, the steps of its preparation method and the reagents, equipment, and process parameters used in each step are the same as those of Example 10. The difference is that the composite anti - settling agent includes 0.2 wt% of RHEOBYK - 420, 0.1 wt% of BYK R 605, 0.3 wt% of RHEOBYK - H7625VF, and 0.4 wt% of AEROSIL 200 based on the mass of the kaolin filler slurry.

[0111] Example 14

[0112] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 10. The difference is that a composite anti-settling agent is also added. The composite anti-settling agent includes 0.1 wt% of RHEOBYK-420, 0.2 wt% of BYK R 605, 0.4 wt% of RHEOBYK-H7625VF, and 0.3 wt% of AEROSIL 200 based on the mass of the kaolin filler slurry.

[0113] Comparative Example 10

[0114] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 10. The difference is that the composite anti-settling agent includes 1 wt% of DISPARLON AQ-607 based on the mass of the kaolin filler slurry.

[0115] Comparative Example 11

[0116] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 10. The difference is that the composite anti-settling agent includes 1 wt% of Guojian SHV based on the mass of the kaolin filler slurry.

[0117] Comparative Example 12

[0118] A high-gloss general-purpose aqueous kaolin filler slurry, the steps of its preparation method, the reagents, equipment, and process parameters used in each step are the same as those in Example 10. The difference is that the composite anti-settling agent includes 1 wt% of RHEOBYK-420 based on the mass of the kaolin filler slurry.

[0119] The kaolin filler slurries of the above Examples 10, 12 - 14 and Comparative Examples 10 - 12 were subjected to a 7-day treatment verification on a shaker at 50°C, with a swing amplitude diameter of 26 mm and a swing frequency of 75 rpm. The properties of the filler slurry were observed. At the same time, a 30-day heat storage treatment verification at 55°C was carried out. The properties of the filler slurry were observed and the percentage decrease in the particle size of the slurry less than 0.8 μm before and after heat storage was measured and recorded. The test results are shown in Table 5 below.

[0120] Table 5 - Performance test results of the kaolin fillers of Examples 10, 12 - 14 and Comparative Examples 10 - 12 of the present application

[0121] As shown in Table 5, compared with the single anti-settling agent in Comparative Examples 10-12, the composite anti-settling agents are used in Examples 10, 12-14 of the present application. The composite anti-settling agents form micelles in the aqueous phase system, and the hydrophobic ends are adsorbed together with the hydrophobic structures in the dispersant and coating resin to form a three-dimensional anti-settling network structure. The hydrophilic ends of the composite anti-settling agents thicken through hydrogen bond hydration to adjust the viscosity of the system, improve the stability of the filler slurry system, and can withstand long-term and high-temperature storage.

[0122] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. In particular, for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-gloss general-purpose water-based kaolin filler slurry, characterized in that: It comprises the following components in parts by weight: Kaolin powder: 60 parts; Dispersant: 1.2 parts; Coating resin: 2 parts; Composite anti-settling agent: 1 part; Solvent: 1-5 parts; Defoaming agent A: 0.3-1 part; Wetting agent A: 0.2-0.5 parts; The total weight of the filler slurry is 100 parts, and the balance is water; The dispersant comprises BYK194, NOPCALL-5180 and SN-1776 in a mass ratio of 2:4:6, 6:2:4 or 6:4:2, and the coating resin comprises THYON PH729, THYON SRT3069, THYON SR675 and THYON SR705 in a mass ratio of (2-8): (2-8): (2-8): (2-8); The composite anti-settling agent comprises RHEOBYK-420, BYK R 605, RHEOBYK-H7625VF and AEROSIL 200 in a mass ratio of 2:1:3:4 or 2:1:4:3; The defoaming agent A is at least one of BYK022, BYK028, TEGO901W, TEGO902W, NOPTAM-398, NOPTAM-1311, and SN-6024; the wetting agent A is at least one of BYK-346, BYK-345, TEGO270, TEGO4100, SURFYNOL465, and SURFYNOL104E.

2. A high-gloss universal water-based kaolin filler slurry as claimed in claim 1, characterized in that: The solvent is at least one of ethanol, propylene glycol, ethylene glycol butyl ether and diethylene glycol monobutyl ether.

3. A method for preparing a high-gloss universal water-based kaolin filler slurry as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: (1) adding the water, solvent, dispersant, defoamer and wetting agent in sequence and mixing them evenly, adding kaolin powder and dispersing them evenly, and then grinding them with a horizontal mill to make the slurry particle size reach 0.8 μm ≥ 95%, thereby obtaining kaolin fine raw material slurry; (2) Grinding the kaolin fine raw material slurry, adding the coating resin and the composite anti-settling agent, and mixing them evenly to obtain a kaolin filler slurry.

4. The method for preparing a high-gloss general-purpose water-based kaolin filler slurry according to claim 3, characterized in that: In step (1), the grinding medium balls include medium balls with diameters of 3 mm, 1.5 mm and 0.8 mm in a mass ratio of 1:2:2, the grinding speed is 500-800 rpm, the grinding time is 1-3 h, and the grinding temperature is less than 70°C.

5. Use of the high-gloss universal water-based kaolin filler slurry as claimed in any one of claims 1 to 2 in the field of preparing water-based emulsion coatings.

6. A water-based emulsion paint, characterized in that: The method comprises 5wt%-20wt% of the high-gloss universal water-based kaolin filler slurry as described in any one of claims 1-2.

7. A water-based emulsion paint as claimed in claim 6, characterized in that: It comprises the following components in parts by weight: Aqueous emulsion: 50-70 parts; Defoaming agent B: 0.3-0.8 parts; Wetting agent B: 0.2-0.6 parts; Leveling agent: 0.1-0.3 parts; Film-forming aid: 2-6 parts; Water-based titanium dioxide slurry: 5-15 parts; High gloss general purpose water-based kaolin filler slurry: 10-20 parts; Water: 10-20 parts; The defoamer B is at least one of BYK022, BYK028, TEGO901W, TEGO902W, NOPTAM-398, NOPTAM-1311, and SN-6024; the wetting agent B is at least one of BYK-346, BYK-345, TEGO270, TEGO4100, SURFYNOL465, and SURFYNOL104E.

8. A water-based emulsion paint as claimed in claim 7, characterized in that: The film-forming aid is C12 alcohol ester.

9. A water-based emulsion paint as claimed in claim 7, characterized in that: The aqueous emulsion is an aqueous acrylic emulsion.

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