Inorganic powder composition for gloss-adjustable extinction and use thereof

Abstract

The application discloses an inorganic powder composition with adjustable glossiness and extinction and application thereof, relates to the technical field of extinction agents, and comprises porous silica powder and fused quartz powder, wherein the porous silica powder is composed of nano-silica aggregates, and the nano-silica is connected through chemical bonds to form a pore interpenetrating structure; when the composition of the two kinds of powder is applied in paint, coating and ink, the glossiness, viscosity and anti-sagging property can be adjusted in a large range to meet different requirements of customers; meanwhile, the functions of the two kinds of powder are clear and obviously different, so that when quality fluctuation occurs, the source can be quickly found, and the problem can be solved in a targeted manner.

Description

Technical fields:

[0001] This invention relates to the field of matting agents, specifically to an inorganic powder composition for matting with adjustable gloss and its application. Background technology:

[0002] Paints, coatings, and inks have a wide range of important applications in various industries, such as furniture, home decoration, industrial coating, automobiles, high-speed rail, airplanes, ships, and electronics, where they play a vital role in aesthetics, dust prevention, easy cleaning, and corrosion protection.

[0003] The gloss and matte finish of paints, coatings, and inks not only affect people's visual and aesthetic experience, but also, in more critical areas such as transportation, impact personal safety and property security. Excessively glossy surfaces can produce strong reflections, threatening the safety of pedestrians, drivers, and passengers. Therefore, matte finishing treatments are necessary for paints, coatings, and inks.

[0004] The principle behind the matting effect of paints, coatings, and inks is that the rough surface of the cured synthetic resin causes light scattering. To achieve this matting effect, the most widely used method is to add an appropriate amount of matting agent (usually a powder) to the synthetic resin. Matting agents include both inorganic and organic powders, with inorganic powders mainly including crystalline quartz powder, titanium dioxide, and barium sulfate. Because inorganic powders are dense and have poor compatibility with organic phases, they are prone to sedimentation. Therefore, to improve the uniformity of dispersion, flowability, sedimentation, and sag of inorganic powders in the organic phase, surface treatment can be applied to the surface of the inorganic powder.

[0005] Patent CN 109852104A discloses a method for preparing a titanium dioxide matting agent. This method first uses aluminum alkoxide to achieve aluminum-coated anatase-type ultrafine titanium dioxide, then uses a silane coupling agent for hydrolytic grafting onto the alumina-coated titanium dioxide powder. Finally, the powder is washed, centrifuged, dried, and pulverized to prepare a matting agent for nylon fibers. This method improves weather resistance by coating titanium dioxide with alumina, while the silane coupling agent treatment improves the compatibility of the powder with the polymer matrix and its dispersion uniformity in the polymer. However, this preparation process involves the uniform addition of raw materials, which is difficult to control. Furthermore, there are many overall process control points, making industrial production relatively difficult to control, and ensuring uniformity between different batches of products is challenging. Moreover, the UV-Vis diffuse reflectance of the alumina-coated titanium dioxide only increases from 82% to 88%, a limited increase.

[0006] Patent CN 107057453A discloses a matting composition comprising: 20-50 wt% barium sulfate powder, 20-50 wt% talc powder, and 20-50 wt% silica powder. This composition achieves a good matting effect, and the raw materials are readily available and inexpensive. However, this method uses a mixture of multiple powders to achieve the matting effect; due to the different powder compositions, it is difficult to achieve good compatibility when added to the same organic phase. Summary of the Invention:

[0007] The technical problem to be solved by this invention is to provide an inorganic powder composition for adjustable gloss matting. This powder can significantly suppress light reflection and reduce gloss, while giving coatings and inks good flowability and anti-sagging properties, ensuring that the processing performance meets customer requirements. By adjusting the ratio of the two components in the composition, the gloss of the synthetic resin can be adjusted as needed.

[0008] The technical problem to be solved by this invention is achieved by the following technical solution:

[0009] An inorganic powder composition for adjustable gloss matting is composed of porous silica powder and fused silica powder. The porous silica powder is composed of aggregated nano-silica, which are connected by chemical bonds to form an interpenetrating pore structure.

[0010] The specific surface area of ​​the inorganic powder composition is 1-200 m². 2 / g, preferably 5-100m 2 / g; oil absorption value is 10-100g / 100g, preferably 30-90g / 100g.

[0011] The weight ratio of the porous silica powder to the fused silica powder is 1:100-10:1, preferably 1:100-1:1.

[0012] The porous silica powder has a median particle size of 1-10 μm, preferably 2-5 μm; and a specific surface area of ​​150-300 m². 2 / g, preferably 180-240m 2 / g; pore diameter is 2-3nm.

[0013] The fused silica powder has a narrow particle size distribution, high purity, a median particle size controlled between 0.1-10 μm, preferably 0.5-1.5 μm, and a specific surface area of ​​0.5-50 m². 2 / g, preferably 5-15m 2 / g.

[0014] The specific steps for preparing the porous silica powder are as follows:

[0015] Step (1): Add nano-silica to water and stir. Turn on the heating to a temperature of 40-80℃ to obtain the mixed slurry.

[0016] Step (2): Adjust the pH of the slurry to 1-5;

[0017] Step (3): Add coupling agent while stirring, react for 8-20 hours to obtain reaction product;

[0018] Step (4): The reaction product is ion cleaned, filtered, dried and pulverized to obtain porous silica powder.

[0019] The mass ratio of water, nano-silica, and coupling agent is 100:(5-15):(1-6).

[0020] The particle size of the nano-silica is 5-50 nm.

[0021] The coupling agent is at least one of silane coupling agents and titanate coupling agents.

[0022] The inorganic powder composition is used in the field of polymer-based composite materials, and the application systems include, but are not limited to, paints, coatings, and inks.

[0023] The inorganic powder composition, after being treated with a silane coupling agent, increases the compatibility of the above-mentioned application system, thereby improving the extinction effect and sag performance of the application system.

[0024] The silane coupling agents include, but are not limited to, methyltrimethoxysilane, triethoxysilane, vinyltrimethoxysilane, triethoxysilane, aminosilane, phenylaminosilane, epoxysilane, and acryloyloxysilane. These silane coupling agents can also be used in the preparation of porous silica powder.

[0025] The beneficial effects of this invention are:

[0026] (1) This invention provides an inorganic powder composition for adjustable gloss matting, comprising a porous silica powder and fused silica powder. The porous silica powder has an interpenetrating pore structure and uniform particle size. Its macroscopically regular and microscopically porous structure is highly conducive to the scattering of incident light, thereby greatly suppressing light reflection and achieving a matting effect. Compared with the prior art, the preparation method of porous silica powder is relatively simple and easy to control in production.

[0027] (2) Since the porous silica powder and fused silica powder are small in size and each component has a uniform particle size, the mechanical properties of the resin matrix are reduced due to uneven particle size. The hardness, stiffness, scratch resistance, high temperature resistance and smoothness of the paint film of the resin matrix are improved. Since both components are silica and have the same elemental composition, the compatibility of the resin matrix is ​​not easily different after the coupling agent is used.

[0028] (3) Since fused silica powder helps maintain the good flowability of synthetic resins, the combination of porous silica powder and fused silica powder can achieve a wide range of adjustments in gloss, viscosity, and anti-sagging properties when applied to paints, coatings, and inks, meeting different customer needs. At the same time, the two powders have clear and distinct functions, making it easy to quickly find the source and address problems in a targeted manner when quality fluctuations occur. Detailed implementation method:

[0029] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0030] The base coats used in the following examples and comparative examples were provided by the customer and are of the type of acrylic / polyurethane resin two-component paint.

[0031] Example 1

[0032] Preparation of porous silica powder:

[0033] Step (1): Add nano-silica to water and stir. Turn on the heater to a temperature of 40°C to obtain the mixed slurry.

[0034] Step (2): Adjust the pH of the slurry to 5;

[0035] Step (3): Add coupling agent while stirring, react for 2 hours to obtain the reaction product;

[0036] Step (4): The reaction product is subjected to ion washing, filtration, drying and pulverization to obtain the porous silica powder of the present invention;

[0037] The mass ratio of the reactants is water: nano-silica: coupling agent = 100:5:1. The nano-silica has a particle size of 50 nm, and the coupling agent is methyltrimethoxysilane.

[0038] The median particle size of the obtained porous silica powder was 10 μm, and the specific surface area was 240 m². 2 / g, the pore diameter was analyzed by the BJH method (desorption method), and the average pore diameter was 3nm.

[0039] Porous silica powder and fused silica powder were mixed in a ratio of 5:95 to obtain an inorganic powder composition, wherein the median particle size of the fused silica powder was 1.0 μm and the specific surface area was 8.9 m². 2 / g.

[0040] Add 650g of base paint to a high-speed shear press and start stirring at 500r / min. Slowly add 350g of inorganic powder composition. After the addition is complete, adjust the speed to 1000r / min and stir for 30min to obtain well dispersed matte paint. Deposit this paint onto a black glass plate to form a 40um wet film. Dry at 80℃ for 24h and measure the gloss.

[0041] Example 2

[0042] Preparation of porous silica powder:

[0043] Step (1): Add nano-silica to water and stir. Turn on the heater to 80°C to obtain the mixed slurry.

[0044] Step (2): Adjust the pH of the slurry to 1;

[0045] Step (3): Add coupling agent while stirring, react for 8 hours to obtain the reaction product;

[0046] Step (4): The reaction product is subjected to ion washing, filtration, drying and pulverization to obtain the porous silica powder of the present invention;

[0047] The mass ratio of the reactants is water: nano-silica: coupling agent = 100:15:6. The nano-silica has a particle size of 5 nm, and the coupling agent is vinyltrimethoxysilane.

[0048] The median particle size of the porous silica powder obtained was 6.0 μm, and the specific surface area was 220 m². 2 / g, the pore diameter was analyzed by the BJH method (desorption method), and the average pore diameter was 2nm.

[0049] Porous silica powder and fused silica powder were mixed in a ratio of 20:80 to obtain an inorganic powder composition, wherein the median particle size of the fused silica powder was 0.8 μm and the specific surface area was 9.8 m². 2 / g.

[0050] Add 650g of base paint to a high-speed shear press and start stirring at 500r / min. Slowly add 350g of powder composition. After the addition is complete, adjust the speed to 1000r / min and stir for 30min to obtain a well dispersed matte paint. Deposit this paint onto a black glass plate to form a 40um wet film. Dry at 80℃ for 24h and measure the gloss.

[0051] Example 3

[0052] Preparation of porous silica powder:

[0053] Step (1): Add nano-silica to water and stir. Turn on the heater to 80°C to obtain the mixed slurry.

[0054] Step (2): Adjust the pH of the slurry to 1;

[0055] Step (3): Add coupling agent while stirring, react for 8 hours to obtain the reaction product;

[0056] Step (4): The reaction product is subjected to ion washing, filtration, drying and pulverization to obtain the porous silica powder of the present invention;

[0057] The mass ratio of the reactants is water: nano-silica: coupling agent = 100:10:4. The nano-silica has a particle size of 5 nm, and the coupling agent is vinyltrimethoxysilane.

[0058] The median particle size of the obtained porous silica powder was 3.0 μm, and the specific surface area was 180 m². 2 / g, the pore diameter was analyzed by the BJH method (desorption method), and the average pore diameter was 2.5nm.

[0059] Porous silica powder and fused silica powder were modified separately using methyltrimethoxysilane coupling agent. The modification method was as follows: the powder was added to a high-speed mixer, and 2% of the modifier by weight of the powder was added. The mixture was stirred at high speed for 10 minutes. The two modified powders were then mixed in a ratio of 20:80 to obtain a modified inorganic powder composition, wherein the median particle size of the fused silica powder was 0.8 μm, and the specific surface area was 9.8 m². 2 / g.

[0060] Add 650g of base paint to a high-speed shear press and start stirring at 500r / min. Slowly add 350g of powder composition. After the addition is complete, adjust the speed to 1000r / min and stir for 30min to obtain a well dispersed matte paint. Deposit this paint onto a black glass plate to form a 40um wet film. Dry at 80℃ for 24h and measure the gloss.

[0061] Comparative Example 1

[0062] Add 650g of base coat to a high-speed shear press and start stirring at 500 rpm. Slowly add 350g of conventional matting agent crystalline quartz powder. The median particle size of the quartz powder is 3.0 μm, and the specific surface area is 7.2 m². 2 / g, after the powder is added, adjust the speed to 1000r / min and stir for 30min to obtain a well dispersed matte varnish. Deposit this varnish on a black glass plate to form a 40um wet film, dry at 80℃ for 24h, and measure the gloss.

[0063] Comparative Example 2

[0064] Conventional matting agent crystalline quartz powder was modified with a methyltrimethoxysilane coupling agent. The modification method was as follows: the powder was added to a high-speed mixer, followed by 2% (by weight) of the modifier, and the mixture was stirred at high speed for 10 minutes. 650g of the base paint was then added to a high-speed shear mixer, and stirring was initiated at 500 rpm. 350g of the modified crystalline quartz powder was then slowly added. The median particle size of the crystalline quartz powder was 3.0 μm, and its specific surface area was 7.2 m². 2 / g, the modified parameters are shown in Table 1. After the powder is added, the speed is adjusted to 1000r / min and stirred for 30min to obtain a well dispersed matte varnish. This varnish is deposited on a black glass plate to form a 40um wet film, dried at 80℃ for 24h, and the gloss is measured.

[0065] Table 1

[0066]

[0067]

[0068] "-" indicates that it is not applicable.

[0069] As shown in Table 1, the inorganic powder composition of the present invention reduces the gloss (60°) of the primer from 61.7 to 3.2-4.1, demonstrating a significant effect in adjusting gloss. Compared with commercially available ordinary crystalline quartz powder, the gloss is reduced from 28.8 to 3.2-4.1, a reduction of over 80%, indicating that the matting effect is superior to conventional matting agent crystalline quartz powder. Furthermore, the gloss is further reduced after modification with a silane coupling agent, indicating that the compatibility between the powder and the system can be adjusted through modification. Table 1 also shows that the inorganic powder composition of the present invention exhibits significant anti-sagging properties.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An inorganic powder composition for matting with adjustable gloss, characterized in that: It is composed of porous silica powder and fused silica powder. The porous silica powder is composed of aggregated nano-silica, which are connected by chemical bonds to form an interpenetrating pore structure. The specific steps for preparing the porous silica powder are as follows: Step (1): Add nano-silica to water and stir. Turn on the heating to a temperature of 40-80℃ to obtain the mixed slurry. Step (2): Adjust the pH of the slurry to 1-5; Step (3): Add coupling agent while stirring, react for 8-20 hours to obtain reaction product; Step (4): The reaction product is subjected to ion washing, filtration, drying and pulverization to obtain porous silica powder; The porous silica powder has a median particle size of 1-10 μm and a specific surface area of ​​150-300 m². 2 / g, with a pore diameter of 2-3nm; The median particle size of the fused silica powder is controlled at 0.1-10 μm, and the specific surface area is 0.5-50 m². 2 / g.

2. The inorganic powder composition for adjustable matting gloss according to claim 1, characterized in that: The specific surface area of ​​the inorganic powder composition is 1-200 m². 2 / g; oil absorption value is 10-100g / 100g.

3. The inorganic powder composition for adjustable matting gloss according to claim 1, characterized in that: The weight ratio of the porous silica powder to the fused silica powder is 1:100-10:

1.

4. The inorganic powder composition for adjustable matting gloss according to claim 1, characterized in that: The mass ratio of water, nano-silica, and coupling agent is 100:(5-15):(1-6); the particle size of the nano-silica is 5-50 nm; and the coupling agent is at least one of silane coupling agent and titanate coupling agent.

5. The application of the inorganic powder composition prepared according to any one of claims 1-4 in the field of polymer-based composite materials, wherein the application system includes, but is not limited to, coatings and inks.

6. The application according to claim 5, characterized in that: The inorganic powder composition is treated with a silane coupling agent.

7. The application according to claim 6, characterized in that: The silane coupling agents include, but are not limited to, methyltrimethoxysilane, triethoxysilane, vinyltrimethoxysilane, aminosilane, epoxysilane, and acryloyloxysilane.

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