A latex paint and a method for preparing the same

Abstract

This invention relates to a latex paint and its preparation method, belonging to the technical field of latex paints. The latex paint raw materials of this invention include raw material A and water. Raw material A, by mass, comprises: 40-60 parts of aqueous polyurethane dispersion A; the particle size of solid particles in aqueous polyurethane dispersion A is 1-2 μm; 10-20 parts of aqueous polyurethane dispersion B; the particle size of solid particles in aqueous polyurethane dispersion B is <0.5 μm; 0-10 parts of titanium dioxide; 10-20 parts of calcium carbonate; 0.5-5 parts of aqueous dispersant; 0.2-5 parts of defoamer; and 0.2-5 parts of thickener. The latex paint of this invention has excellent skin feel and good scrub resistance.

Description

Technical Field

[0001] This invention belongs to the field of latex paint technology, specifically relating to a latex paint and its preparation method. Background Technology

[0002] Latex paint is the most common type of interior paint decoration. Interior paint is an important part of interior design and decoration. As people's living standards improve, they are also starting to demand more functionality and uniqueness in interior decoration styles, hoping to add more effects, such as functional products like formaldehyde-removing paint and lotus leaf paint.

[0003] In order to better meet people's pursuit of quality of life, the development of more functional and unique latex paints has become a current research hotspot. Summary of the Invention

[0004] Therefore, the present invention provides a latex paint and a method for preparing the same. The latex paint of the present invention is white and has a skin-like feel, while also having excellent washability.

[0005] To this end, the present invention provides the following technical solution.

[0006] In a first aspect, the present invention provides a latex paint, the raw materials of which include raw material A and water, wherein raw material A comprises, by weight:

[0007] 40-60 parts of waterborne polyurethane dispersion A; the particle size of the solid particles in waterborne polyurethane dispersion A is 1-2 μm;

[0008] 10-20 parts of waterborne polyurethane dispersion B; the particle size of the solid particles in waterborne polyurethane dispersion B is <0.5 μm;

[0009] 0-10 parts of titanium dioxide;

[0010] 10-20 parts calcium carbonate;

[0011] 0.5 to 5 parts of aqueous dispersant;

[0012] Defoamer 0.2-5 parts;

[0013] Thickener 0.2 to 5 parts.

[0014] In one possible implementation, the mass of the water is 0.1 to 0.5 times the total mass of raw material A, preferably 0.1 to 0.2 times.

[0015] Preferably, the pH of the latex paint is 7 to 9.

[0016] In one possible implementation, the aqueous polyurethane dispersion A and the aqueous polyurethane dispersion B are each independently selected from at least one or more of the following: aqueous aliphatic polyether polyurethane dispersion, aqueous aliphatic polyester polyurethane dispersion, aqueous aromatic polyether polyurethane dispersion, and aqueous aromatic polyester polyurethane dispersion.

[0017] Optionally, the waterborne polyurethane dispersion A is a waterborne aliphatic polyether polyurethane dispersion.

[0018] Optionally, waterborne polyurethane dispersion B is a waterborne aliphatic polyester polyurethane dispersion, whose flexibility can give latex paint a better damping feel and further improve the skin feel.

[0019] In one possible implementation, titanium dioxide comprises one or both of anatase and rutile titanium dioxide. Titanium dioxide can be purchased directly or produced via sulfuric acid or chloride processes.

[0020] In one possible implementation, the calcium carbonate comprises heavy calcium carbonate and / or light calcium carbonate;

[0021] Preferably, the calcium carbonate comprises calcium carbonate powder of 300-2000 mesh;

[0022] Preferably, the calcium carbonate comprises calcium carbonate powder of 300-800 mesh and 1000-2000 mesh.

[0023] Optionally, the calcium carbonate includes one or more of the following: 300 mesh, 800 mesh, 1000 mesh and 1500 mesh calcium carbonate powder.

[0024] Optionally, calcium carbonate includes calcium carbonate powder with two or more mesh sizes. The calcium carbonate powder with multiple mesh sizes is layered and matched. The fine mesh powder can fill the gaps of the larger mesh powder, making the entire powder more compact and improving properties such as washability and hiding power.

[0025] In one possible implementation, the aqueous dispersant includes one or more of the following: aqueous acrylic homopolymer sodium salt, aqueous acrylic homopolymer ammonium salt, aqueous acrylic copolymer sodium salt, and aqueous acrylic copolymer ammonium salt.

[0026] In one possible implementation, the defoamer includes one or more of silicone, polyether, and non-silicone defoamers, preferably one or more of silicone emulsion-type, non-silicone phosphate ester, and mineral oil-type defoamers.

[0027] In one possible implementation, the thickener is a water-based alkali-swellable thickener; preferably, the water-based alkali-swellable thickener includes one or more of anionic and nonionic alkali-swellable thickeners. The high thickening efficiency and low flowability of the water-based alkali-swellable thickener improve the spraying performance and feel of the latex paint.

[0028] In one possible implementation, the latex paint has a solids content of 30-55% by weight;

[0029] Preferably, the latex paint has a Stormo viscosity of 75-105 Ku when tested with Stormo viscosity agent at 25°C and 50% humidity.

[0030] In a second aspect, the present invention provides a method for preparing latex paint, comprising mixing various raw materials to obtain latex paint.

[0031] In one possible implementation, the preparation method includes the following steps:

[0032] S1. Mix the thickener and water evenly to obtain pre-mixed liquid A;

[0033] Pre-formulated solution B is prepared by mixing titanium dioxide, calcium carbonate, aqueous dispersant, defoamer and water;

[0034] S2. Mix the aqueous polyurethane dispersion and the preformed liquid B to obtain the preformed liquid C;

[0035] S3. Add pre-prepared liquid A to pre-prepared liquid C, filter and discharge to obtain latex paint;

[0036] Preferably, titanium dioxide, calcium carbonate, aqueous dispersant, defoamer and water are mixed and then dispersed using a disperser at a speed of 1800-2500 RPM for 30-60 minutes.

[0037] Preferably, after mixing the aqueous polyurethane dispersion and the preform B, the mixture is stirred at a uniform speed of 600 RPM to 800 RPM using a disperser.

[0038] Preferably, pre-prepared liquid A is added to pre-prepared liquid C, and after the addition is complete, the mixture is stirred at a constant speed for 20 to 40 minutes.

[0039] Pre-mixed liquid A is prepared by mixing thickener and water, which avoids the formation of particles in the latex paint system that may occur if the thickener is added directly to the system.

[0040] In the process of preparing latex paint, using some water first and then adding the rest at the end can avoid the problem of the raw materials not being easily dispersed during the stirring process due to the initial low viscosity.

[0041] The conditions inside the production vessel are, for example, indoor environment, temperature 5-40℃, humidity 5%-95%, and standard atmospheric pressure.

[0042] Latex paint can be easily applied using a roller, a soft brush, or a spray gun. These methods are suitable for general latex paint application and offer advantages such as ease of use and good adaptability.

[0043] The technical solution of this invention has the following advantages:

[0044] 1. The latex paint raw material of the present invention includes raw material A and water. Raw material A, by mass parts, includes: 40-60 parts of waterborne polyurethane dispersion A; the particle size of the solid particles in waterborne polyurethane dispersion A is 1-2 μm; 10-20 parts of waterborne polyurethane dispersion B; the particle size of the solid particles in waterborne polyurethane dispersion B is <0.5 μm; 0-10 parts of titanium dioxide; 10-20 parts of calcium carbonate; 0.5-5 parts of waterborne dispersant; 0.2-5 parts of defoamer; and 0.2-5 parts of thickener.

[0045] This invention provides a white latex paint with a skin-like feel. The latex paint contains a waterborne polyurethane dispersion A with solid particles having a particle size of 1-2 μm. The larger particle size, after drying, forms an uneven resin surface on the dry film, making the surface morphology similar to human skin. Furthermore, the polyether or polyester segments in the dispersion provide a soft and resilient feel to the paint film. Compared to traditional acrylic polymers, this system has higher resilience and damping, making its feel even closer to that of skin. The waterborne polyurethane dispersion B contains solid particles with a particle size <0.5 μm. The smaller particle size makes the paint film surface smoother and more even, effectively improving scrub resistance.

[0046] The larger particle size of the waterborne polyurethane dispersion A enables diffuse reflection on the paint film surface, increasing the tactile feel of the latex paint while reducing gloss. This prevents unevenness and other details on the wall surface from being exposed due to a glossy paint film, further improving the paint's concealing properties. Furthermore, the latex paint of this invention has low VOC content and low odor.

[0047] The skin-feel latex paint of this invention has the advantages of excellent touch, workability, low-temperature film-forming properties, low gloss, and good environmental performance, and is especially suitable for use in the field of interior wall decorative coatings.

[0048] 2. The latex paint preparation method of the present invention is applicable to general latex paint production methods and has the advantages of simple operation and good equipment adaptability. Detailed Implementation

[0049] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0050] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0051] Table 1. Raw Material Information

[0052]

[0053] Example 1

[0054] This embodiment provides a latex paint, the raw materials of which include: 50g titanium dioxide, 135g calcium carbonate (1500 mesh), 5g water-based dispersant, 5g defoamer, 400g water-based polyurethane dispersion A, 100g water-based polyurethane dispersion B, 5g thickener and 305g water.

[0055] This embodiment provides a method for preparing the above-mentioned latex paint, including:

[0056] S1. Mix the thickener and water at a mass ratio of 1:1 to obtain the pre-mixed liquid A;

[0057] Titanium dioxide, calcium carbonate, aqueous dispersant, defoamer and 200g water were mixed and dispersed in a reactor at high speed using a disperser at 2000RPM for 45min to obtain pre-prepared liquid B.

[0058] S2. After mixing the aqueous polyurethane dispersion and the preform B, stir the mixture in a reactor using a disperser at a speed of 800 RPM to obtain the preform C.

[0059] S3. Add pre-prepared liquid A and 100g of water to pre-prepared liquid C. After the addition is complete, adjust the pH to 7-9, continue stirring at a constant speed for 30 minutes, filter through a 100-mesh filter to obtain latex paint.

[0060] Examples 2-8 were prepared using essentially the same method as in Example 1, with the only difference being that the raw materials were selected and the amounts used in each example were adjusted according to Table 2.

[0061] Table 2. Raw material selection and weight (g) for each embodiment.

[0062]

[0063]

[0064] Comparative Examples 1-4 were prepared using essentially the same method as Example 1, with the only difference being that the raw materials were selected and the amounts used in each example were adjusted according to Table 3.

[0065] Table 3. Raw material selection and dosage in Comparative Examples 1-4 (unit: g)

[0066]

[0067] The latex paints prepared in each embodiment and comparative example were tested for film feel, surface drying time, gloss, low-temperature film-forming properties, film appearance, and scrub resistance. The test methods were as follows:

[0068] Paint film touch test method: Latex paint is sprayed on a sprayer, with two coats of putty applied during application. The wet film thickness is approximately 300 micrometers. After 72 hours, the paint film surface is touched with fingers / palms, and a score of 0-5 is given based on how closely the paint film resembles the feel of skin. 0 points represent a rough feel, and 5 points represent a skin-like feel. Ten testers are assigned to evaluate the paint film, and the average score of the ten scores is taken.

[0069] Test methods for paint film surface drying time, low temperature film formation, scrub resistance and paint film appearance: described according to the requirements for topcoat in GB / T9756-2018 "Synthetic Resin Emulsion Interior Wall Coatings".

[0070] Gloss test: Under the conditions of 25℃ and 50% humidity, the coating is applied to black and white cardstock using a 100-micron gauge wire rod. After curing for 24 hours, the gloss is tested at a 60° angle using a gloss meter.

[0071] The test results are shown in Tables 4 and 5.

[0072] Table 4. Test results of paint film properties obtained from latex paint in the examples.

[0073]

[0074] Table 5. Test results of paint film properties obtained from latex paint in the comparative examples.

[0075] performance Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Surface drying time <2h <2h <2h <2h Stormer viscosity 90-95ku 100-105ku 95-100ku >105ku gloss <10％ 30％～40％ 30％～40％ <10％ Paint film appearance normal normal normal normal Low temperature film formation pass pass pass pass Paint film feel 5 2 0 2 Scrub resistance <350 times >1000 times >1000 times <350 times

[0076] As shown in Tables 4 and 5, the paint film obtained by the latex paint of the present invention has a skin-like feel and a washability of >350 cycles, which meets the requirements of GB / T9756-2018.

[0077] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A latex paint, characterized in that, The raw materials include raw material A and water. Raw material A, by mass, comprises: 40-60 parts of waterborne polyurethane dispersion A; the particle size of the solid particles in waterborne polyurethane dispersion A is 1-2 μm; 10-20 parts of waterborne polyurethane dispersion B; the particle size of the solid particles in waterborne polyurethane dispersion B is <0.5 μm; 0-10 parts of titanium dioxide; 10-20 parts calcium carbonate; 0.5 to 5 parts of aqueous dispersant; Defoamer 0.2-5 parts; Thickener 0.2 to 5 parts.

2. The latex paint according to claim 1, characterized in that, The mass of the water is 0.1 to 0.5 times the total mass of raw material A, preferably 0.1 to 0.2 times; Preferably, the pH of the latex paint is 7 to 9.

3. The latex paint according to claim 1, characterized in that, The aqueous polyurethane dispersion A and aqueous polyurethane dispersion B are each independently selected from at least one or more of the following: aqueous aliphatic polyether polyurethane dispersion, aqueous aliphatic polyester polyurethane dispersion, aqueous aromatic polyether polyurethane dispersion, and aqueous aromatic polyester polyurethane dispersion.

4. The latex paint according to claim 1, characterized in that, Titanium dioxide includes one or both of anatase and rutile titanium dioxide.

5. The latex paint according to claim 1, characterized in that, The calcium carbonate includes heavy calcium carbonate and / or light calcium carbonate; Preferably, the calcium carbonate comprises calcium carbonate powder of 300-2000 mesh; Preferably, the calcium carbonate comprises calcium carbonate powder of 300-800 mesh and 1000-2000 mesh.

6. The latex paint according to claim 1, characterized in that, Aqueous dispersants include one or more of the following: aqueous acrylic homopolymer sodium salt, aqueous acrylic homopolymer ammonium salt, aqueous acrylic copolymer sodium salt, and aqueous acrylic copolymer ammonium salt.

7. The latex paint according to claim 1, characterized in that, Defoamers include one or more of silicone, polyether, and non-silicone defoamers, preferably one or more of silicone emulsion-type defoamers, phosphate ester-type and mineral oil-type non-silicone defoamers.

8. The latex paint according to claim 1, characterized in that, The thickener is an aqueous alkali-swellable thickener; preferably, the aqueous alkali-swellable thickener includes one or more of anionic alkali-swellable thickeners and nonionic alkali-swellable thickeners.

9. A method for preparing the latex paint according to any one of claims 1-8, characterized in that, This includes mixing various raw materials to produce latex paint.

10. The method for preparing latex paint according to claim 9, characterized in that, The preparation method includes the following steps: S1. Mix the thickener and water evenly to obtain pre-mixed liquid A; Pre-formulated solution B is prepared by mixing titanium dioxide, calcium carbonate, aqueous dispersant, defoamer and water; S2. Mix the aqueous polyurethane dispersion and the preformed liquid B to obtain the preformed liquid C; S3. Add pre-prepared liquid A to pre-prepared liquid C, filter and discharge to obtain latex paint; Preferably, titanium dioxide, calcium carbonate, aqueous dispersant, defoamer and water are mixed and then dispersed using a disperser at a speed of 1800-2500 RPM for 30-60 minutes. Preferably, after mixing the aqueous polyurethane dispersion and the preform B, the mixture is stirred at a uniform speed of 600 RPM to 800 RPM using a disperser. Preferably, pre-prepared liquid A is added to pre-prepared liquid C, and after the addition is complete, the mixture is stirred at a constant speed for 20 to 40 minutes.

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