Environment-friendly long-acting mildew-proof and antibacterial interior wall putty powder and preparation method thereof

Abstract

The application discloses an environment-friendly long-acting mildew-proof and antibacterial interior wall putty powder and a preparation method thereof, and particularly relates to the technical field of building materials, and comprises the following raw materials in parts by weight: 80-88 parts of heavy calcium carbonate; 1-5 parts of grey calcium; 10-15 parts of white cement; 0.1-1 part of cellulose ether; 0.01-1 part of lignocellulose; 0.1-1 part of glue powder; and 1-5 parts of modified wood wax oil. The application has excellent long-term mildew-proof and antibacterial performance, overcomes the defects that traditional organic mildew-proof agents are prone to loss and quick failure, is green, environment-friendly, safe and non-toxic, meets the demand of consumers for a healthy living environment, and can enhance the adhesion and adaptability to a base material, and has good construction performance and dispersibility. The raw materials have excellent compatibility, the process is simple, industrial production is easy, raw materials are widely sourced, cost is controllable, and the application has good economic efficiency and market promotion value.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and more specifically, to an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder and its preparation method. Background Technology

[0002] Putty powder is a key supporting material for leveling the base layer in building coating projects. Its main functions are to fill minor defects in the wall, correct the flatness of the base, and provide a firm and uniform adhesion base for subsequent paint layers. As an indispensable intermediate layer before painting, the putty layer not only directly affects the decorative effect of the wall, but also effectively prevents quality problems such as peeling, cracking, and flaking caused by uneven base or insufficient adhesion. Therefore, putty powder has a wide range of applications in the field of building decoration.

[0003] In recent years, with rapid economic development and a significant improvement in people's living standards, the aesthetics and health and safety of indoor living environments have received increasing attention. Consumers' requirements for building decoration materials are no longer limited to basic functionality, but rather they are paying more attention to the environmental protection attributes and additional health benefits of materials. While traditional interior wall putty powder can meet the basic needs of leveling construction, its function is relatively limited, lacking effective inhibition of microbial growth. In high-humidity environments or poorly ventilated indoor spaces (such as basements, walls adjacent to bathrooms, and rooms during the rainy season in southern China), the putty layer easily absorbs moisture and becomes a breeding ground for mold, bacteria, and other microorganisms. Mold on walls not only damages the aesthetics of the decoration but also releases microbial metabolic products, reducing indoor air quality and posing a potential risk to the respiratory health of residents.

[0004] Many existing anti-mildew putty products achieve their antibacterial and anti-mildew effects by adding heavy metals (such as mercury, lead, cadmium, etc.) or organic synthetic anti-mildew agents (such as isothiazolinones, benzimidazoles, etc.). Although these ingredients have a certain inhibitory effect in the short term, they pose health and safety risks such as heavy metal toxicity or skin sensitization, which contradicts the current green and environmentally friendly decoration concept. On the other hand, organic anti-mildew agents are easily decomposed and ineffective in alkaline putty environments, or they migrate and run off rapidly during use, making it difficult to maintain the anti-mildew and antibacterial effect. This often results in the common problem of being effective in the early stage but ineffective in the later stage.

[0005] Therefore, there is an urgent need for an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder and its preparation method to solve the above problems. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder and its preparation method, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder, comprising the following raw materials in parts by weight:

[0008] 80-88 parts of heavy calcium carbonate;

[0009] 1-5 parts of gray calcium;

[0010] 10-15 parts white cement;

[0011] Cellulose ether 0.1-1 part;

[0012] Lignocellulose 0.01-1 part;

[0013] 0.1-1 part of adhesive powder;

[0014] 1-5 parts of modified wood wax oil.

[0015] In a preferred embodiment, the preparation steps of the modified wood wax oil are as follows:

[0016] a. Dissolve tea polyphenols and tea saponins in any one of the mixed solvents of ethanol and water, stir thoroughly until completely dissolved, then add nano-mesoporous titanium dioxide, place in an ultrasonic dispersion device for ultrasonic dispersion, after ultrasonication, allow to stand at room temperature for adsorption, and then transfer the adsorbed slurry to a vacuum drying oven for vacuum drying to obtain functional nanocomposite powder with preloaded active ingredients.

[0017] b. Add the above composite powder to the wood wax oil base in proportion, disperse it using a high-speed disperser, let it stand to defoam after dispersion, and then seal and mature it to obtain the modified wood wax oil with slow-release antibacterial and antifungal functions.

[0018] In a preferred embodiment, the mass ratio of wood wax oil, tea polyphenols, tea saponins, and nanoporous titanium dioxide in the modified wood wax oil is 100:1-20:1-20:1:20.

[0019] In a preferred embodiment, the reaction in step a involves ultrasonic dispersion for 20-30 minutes, static adsorption for 12 hours, and vacuum drying at a temperature of 40°C-50°C.

[0020] In a preferred embodiment, the reaction in step b involves a high-speed dispersion rate of 15,000-20,000 rpm and a high-speed dispersion time of 10-20 minutes.

[0021] A method for preparing an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder, comprising the environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder as described in any one of the above-mentioned methods, and the following steps:

[0022] Step 1: Weigh the raw materials, including heavy calcium carbonate, lime, white cement, cellulose ether, lignocellulose, adhesive powder, and modified wood wax oil, according to the stated weight proportions.

[0023] Step 2: Add heavy calcium carbonate, lime, white cement, cellulose ether, lignocellulose, adhesive powder, and modified wood wax oil to either a dry powder mixer or a vertical mixer and mix. Stir at 20-50 rpm for 15-25 minutes at room temperature until the mixture is homogeneous to obtain an environmentally friendly, long-lasting, mildew-proof, and antibacterial interior wall putty powder.

[0024] The technical effects and advantages of this invention are as follows:

[0025] 1. This invention possesses excellent long-term anti-mold and antibacterial properties. It introduces wood wax oil modified with tea polyphenols, tea saponins, and nano-mesoporous titanium dioxide into putty powder. Tea polyphenols, as a natural polyphenolic antibacterial agent, effectively inhibit the growth of common wall molds (such as Aspergillus niger and Penicillium) and bacteria. Due to its unique pore structure, nano-mesoporous titanium dioxide provides loading and slow-release effects for tea polyphenols and tea saponins, significantly extending the release cycle of the active ingredients. This allows the putty layer to maintain stable anti-mold and antibacterial activity during long-term use, overcoming the shortcomings of traditional organic anti-mold agents, such as easy loss and rapid failure.

[0026] 2. This invention is green, environmentally friendly, safe, and non-toxic. The wood wax oil, tea polyphenols, and tea saponins used in this invention are all natural materials, free from heavy metals, formaldehyde, volatile organic compounds (VOCs), and synthetic antifungal agents such as isothiazolinones. It is non-irritating to human skin and respiratory system, and meets the requirements of GB 30981.1 "Limits of Hazardous Substances in Coatings - Part 1: Architectural Coatings" and green building materials evaluation standards, satisfying consumers' demand for a healthy living environment.

[0027] 3. This invention can enhance adhesion and substrate adaptability. The introduction of modified wood wax oil in this invention not only gives the putty powder anti-mildew and antibacterial functions, but also improves the interfacial bonding ability between the putty layer and various substrates. Experiments show that the putty powder of this invention exhibits good bonding strength with common wall bases such as cement substrates, gypsum board, and wood boards. It has a low drying shrinkage rate, effectively reducing the risk of wall peeling, cracking and falling off, and is suitable for different interior decoration scenarios.

[0028] 4. This invention exhibits excellent workability and dispersibility. Due to the natural surface activity of tea saponin, it promotes the uniform dispersion of modified wood wax oil in the putty powder system, preventing the agglomeration of functional components and ensuring the smoothness, water retention, and construction time of the putty powder during application. There is no abnormal odor during construction, the application is smooth, and the surface is flat and delicate after drying, with good sandability, facilitating subsequent paint application.

[0029] 5. The raw materials of this invention have excellent compatibility. No layering, precipitation or reaction sedimentation occurs between wood wax oil and inorganic fillers. Nanoporous titanium dioxide serves as a carrier, further enhancing the chemical stability of functional components in alkaline putty environment and ensuring that the product's performance does not degrade during storage and use.

[0030] 6. The process of this invention is simple and easy to industrialize. The preparation method of this invention adopts a pre-composite and high-speed dispersion process, which is simple to operate, has low equipment requirements, does not require high temperature and high pressure or complex post-processing, and is suitable for large-scale industrial production. At the same time, the raw materials are widely available and the cost is controllable, which has good economic benefits and market promotion value. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention provides an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder and its preparation method, comprising the following raw materials in parts by weight:

[0033] 80-88 parts of heavy calcium carbonate;

[0034] 1-5 parts of gray calcium;

[0035] 10-15 parts white cement;

[0036] Cellulose ether 0.1-1 part;

[0037] Lignocellulose 0.01-1 part;

[0038] 0.1-1 part of adhesive powder;

[0039] 1-5 parts of modified wood wax oil.

[0040] The preparation steps of the modified wood wax oil are as follows:

[0041] a. Pre-composite process: Dissolve tea polyphenols and tea saponins in any mixed solvent of ethanol and water (preferably a volume ratio of 5:1 to 3:1), stir thoroughly until completely dissolved, then add nanoporous titanium dioxide, place in an ultrasonic dispersion device, and ultrasonically disperse for 20-30 minutes at 40 kHz and 100-200W to remove air from the pores and promote the diffusion of active molecules into the mesopores. After ultrasonication, allow to stand at room temperature for 12 hours to fully load tea polyphenols and tea saponins into the pores of the nanoporous titanium dioxide. Finally, transfer the adsorbed slurry to a vacuum drying oven and vacuum dry at 40-50°C for 12-24 hours to remove the solvent, obtaining loose functional nanocomposite powder. It should be noted that the drying temperature should not exceed 60°C to avoid oxidation and inactivation of tea polyphenols.

[0042] b. Dispersion and Curing: Add the composite powder obtained in the above steps to the wood wax oil base in the required proportion and disperse it using a high-speed disperser at a speed of 15,000-20,000 rpm for 10-20 minutes. This speed range is much higher than the stirring speed in conventional wood wax oil modification (usually 1,500-2,000 rpm). The purpose is to use high shear force to fully deagglomerate the nanocomposite powder and disperse it evenly in the high-viscosity wood wax oil system. After dispersion, let it stand for 30-60 minutes to defoam, and then seal and cure for 24 hours to allow the interfaces of each component to fully balance, thus obtaining the modified wood wax oil product with slow-release antibacterial and antifungal functions.

[0043] The modified wood wax oil contains wood wax oil, tea polyphenols, tea saponins, and nanoporous titanium dioxide in a mass ratio of 100:1-20:1-20:1:20.

[0044] A method for preparing an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder, comprising the environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder as described in any one of the above-mentioned methods, and the following steps:

[0045] Step 1: Accurately weigh all raw materials according to the above weight proportions: heavy calcium carbonate, lime, white cement, cellulose ether, lignocellulose, glue powder, and modified wood wax oil;

[0046] Step 2: Add heavy calcium carbonate, lime, white cement, cellulose ether, lignocellulose, adhesive powder, and modified wood wax oil to either a dry powder mixer or a vertical mixer and mix at room temperature at a speed of 20-50 rpm for 15-25 minutes until all components are evenly mixed and have a consistent color. Then, discharge and package the mixture to obtain an environmentally friendly, long-lasting, mildew-proof, and antibacterial interior wall putty powder.

[0047] In actual use, add an appropriate amount of water (usually 35%-45% of the powder weight) to the above putty powder, stir into a uniform paste, let stand for 5-10 minutes, stir again until uniform, and then apply.

[0048] To make the technical solution of this invention clearer, three specific embodiments are provided below. All raw materials used in these embodiments are commercially available industrial-grade products. The wood wax oil base is a solvent-free clear oil blended from natural plant oils and natural waxes; the tea polyphenol purity is ≥90%; the tea saponin purity is ≥60%; and the nanoporous titanium dioxide has a pore size of 5-20 nm and a specific surface area ≥200 m². 2 / g.

[0049] Example 1

[0050] Raw material weight parts: 84 parts heavy calcium carbonate, 3 parts lime, 12 parts white cement, 0.5 parts cellulose ether (hydroxypropyl methylcellulose), 0.3 parts lignocellulose, 0.4 parts adhesive powder (vinyl acetate-ethylene copolymer), 2 parts modified wood wax oil. Modified wood wax oil preparation parameters: the mass ratio of wood wax oil, tea polyphenols, tea saponins, and nano-mesoporous titanium dioxide is 100:5:5:5. In step a, ultrasonic dispersion is performed for 25 minutes, static adsorption is allowed for 12 hours, and vacuum drying is carried out at 45℃. In step b, high-speed dispersion is performed at 16000 rpm for 15 minutes.

[0051] Putty powder preparation: Weigh the raw materials according to the above ratio, mix and stir for 20 minutes to obtain the putty powder product.

[0052] Example 2

[0053] Raw material weight parts: 80 parts heavy calcium carbonate, 5 parts lime, 10 parts white cement, 0.8 parts cellulose ether (methylcellulose), 0.6 parts lignocellulose, 0.8 parts adhesive powder (acrylic adhesive powder), and 4 parts modified wood wax oil.

[0054] Preparation parameters of modified wood wax oil: The mass ratio of wood wax oil, tea polyphenols, tea saponins and nano-mesoporous titanium dioxide is 100:12:10:15. In step a, ultrasonic dispersion is performed for 30 minutes, static adsorption is performed for 12 hours, and vacuum drying is performed at 50℃. In step b, high-speed dispersion is performed at 18000 rpm for 10 minutes.

[0055] Putty powder preparation: Weigh the raw materials according to the above ratio, mix and stir for 15 minutes to obtain the putty powder product.

[0056] Example 3

[0057] Raw material weight parts: 88 parts heavy calcium carbonate, 1 part lime, 15 parts white cement, 0.2 parts cellulose ether (hydroxyethyl cellulose), 0.1 parts lignocellulose, 0.2 parts adhesive powder (polyvinyl acetate adhesive powder), and 5 parts modified wood wax oil.

[0058] Preparation parameters of modified wood wax oil: The mass ratio of wood wax oil, tea polyphenols, tea saponins and nano-mesoporous titanium dioxide is 100:18:18:8. The mixture is ultrasonically dispersed in S1 for 20 minutes, allowed to stand for 12 hours for adsorption, and vacuum dried at 40℃. In S2, the mixture is dispersed at high speed at 15000 rpm for 20 minutes.

[0059] Putty powder preparation: Weigh the raw materials according to the above ratio, mix and stir for 25 minutes to obtain the putty powder product.

[0060] Example 4

[0061] Raw material weight parts: 85 parts heavy calcium carbonate, 4 parts lime, 13 parts white cement, 0.4 parts cellulose ether, 0.2 parts lignocellulose, 0.3 parts glue powder, and 3 parts modified wood wax oil.

[0062] Preparation parameters of modified wood wax oil: The mass ratio of wood wax oil, tea polyphenols, tea saponins and nano-mesoporous titanium dioxide is 100:10:10:10. In S1, it is ultrasonically dispersed for 25 minutes, allowed to stand for adsorption for 12 hours, and vacuum dried at 45℃. In S2, it is dispersed at high speed of 17500 rpm for 15 minutes.

[0063] Putty powder preparation: Weigh the raw materials according to the above ratio, mix and stir for 20 minutes to obtain the putty powder product.

[0064] Comparative Example 1

[0065] The raw materials did not contain modified wood wax oil, and the remaining components were the same as in Example 4. After application, the prepared putty powder was tested and found to have the following properties: anti-mold grade 3 (obvious mold growth), antibacterial rate <30%, and bonding strength 0.55 MPa. This indicates that conventional putty powder without modified wood wax oil lacks anti-mold and antibacterial capabilities.

[0066] Comparative Example 2

[0067] Using the same weight proportions of ordinary wood wax oil (unmodified with tea polyphenols, tea saponins, and nanoporous titanium dioxide) instead of the modified wood wax oil in Example 4, the test results showed: a mildew resistance level of 2, an antibacterial rate of approximately 50%, and a bond strength of 0.58 MPa. Furthermore, after 14 days of accelerated aging, the antibacterial rate decreased to below 20%. This indicates that while the unmodified wood wax oil has a temporary inhibitory effect, it cannot achieve long-term mildew and antibacterial protection.

[0068] Comparative Example 3

[0069] The modified wood wax oil was prepared without the addition of nanoporous titanium dioxide, otherwise the process was the same as in Example 4. Test results: Initially, the anti-mold level was 0 and the antibacterial rate was ≥99%. However, after 30 days of accelerated aging, the anti-mold level dropped to 2 and the antibacterial rate dropped to below 60%, indicating that the lack of the sustained-release effect of nanoporous titanium dioxide resulted in rapid loss of active ingredients and difficulty in achieving a lasting effect.

[0070] The interior wall putty powders prepared in Examples 1-4 and Comparative Examples 1-3 were used as samples for performance testing. The test results are shown in Table 1.

[0071] Table 1

[0072] Test Project Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Anti-mildew performance (mildew growth level) Level 0 Level 0 Level 0 Level 0 Level 0 Level 3 Level 2 Level 1 Antibacterial rate (Staphylococcus aureus, %) ≥99 ≥99 ≥99 ≥99 ≥99 <30 Approximately 50 ≥99 Bond strength (MPa) 0.62 0.58 0.65 0.70 0.72 0.55 0.58 0.68 Drying time (surface dry, h) ≤2 ≤2 ≤2 ≤2 ≤2 ≤2 ≤2 ≤2 Water resistance (96h) No abnormalities No abnormalities No abnormalities No abnormalities No abnormalities Slight bubbling No abnormalities No abnormalities VOC content (g / L) Not detected Not detected Not detected Not detected Not detected Not detected Not detected Not detected Sustained-release period (days) >60 >60 >60 >90 >90 — <14 Approximately 30

[0073] Anti-mold and antibacterial properties: The anti-mold level of Examples 1-5 was all 0 (the highest level), and the antibacterial rate against Staphylococcus aureus was all above 99%, demonstrating excellent anti-mold and antibacterial capabilities. Comparative Example 1 (without modified wood wax oil) had almost no anti-mold and antibacterial effect, with a mold growth level of 3; Comparative Example 2 (using unmodified wood wax oil) had a certain initial inhibitory effect, but the effect was limited; Comparative Example 3 (modified wood wax oil lacking nanoporous titanium dioxide) had excellent initial performance, but the later performance deteriorated significantly.

[0074] Sustained-release effect: The sustained-release period of Examples 1-3 exceeded 60 days, and the sustained-release period of Examples 4-5 exceeded 90 days, indicating that the sustained-release effect of nano-mesoporous titanium dioxide on the loading of tea polyphenols and tea saponins is significant. The sustained-release period of Comparative Example 2 was less than 14 days, and that of Comparative Example 3 was only about 30 days, proving that the synergistic effect of tea saponins and nano-mesoporous titanium dioxide is the key to achieving long-lasting antifungal and antibacterial effects.

[0075] Bond strength and mechanical properties: The bond strength of all embodiments reached ≥0.58 MPa, which is higher than the requirement of JG / T 298-2010 standard (≥0.50 MPa), with Embodiment 5 (preferred ratio) reaching 0.72 MPa. The introduction of modified wood wax oil not only did not weaken the adhesion, but also enhanced the interfacial bonding due to the good permeability of wood wax oil.

[0076] Environmental performance: The VOC content of all examples and comparative examples was undetectable, which meets the requirements of the revised GB / T30981.1-2025 standard, proving the green and environmentally friendly characteristics of this invention with natural materials as the core.

[0077] Based on the above test results, the environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder provided by this invention (Examples 1-5) is significantly superior to the comparative products in terms of anti-mildew and antibacterial performance, slow-release and long-lasting effect, bonding strength, environmental friendliness, and construction performance. Among them, Example 5 is the preferred formulation case, with the best overall performance, having a slow-release period of over 90 days and a bonding strength of 0.72 MPa, fully meeting the requirements of high-quality interior decoration materials. This invention, through the synergistic modification of tea polyphenols, tea saponins, and nano-mesoporous titanium dioxide, and their introduction into the putty powder, enables the product to possess efficient and long-lasting anti-mildew and antibacterial properties, excellent construction performance, and green environmental protection characteristics. Each component is indispensable.

[0078] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder, characterized in that, The ingredients include the following parts by weight: 80-88 parts of heavy calcium carbonate; 1-5 parts of gray calcium; 10-15 parts white cement; Cellulose ether 0.1-1 part; Lignocellulose 0.01-1 part; 0.1-1 part of adhesive powder; 1-5 parts of modified wood wax oil.

2. The environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder according to claim 1, characterized in that, The preparation steps of the modified wood wax oil are as follows: a. Dissolve tea polyphenols and tea saponins in any one of the mixed solvents of ethanol and water, stir thoroughly until completely dissolved, then add nano-mesoporous titanium dioxide, place in an ultrasonic dispersion device for ultrasonic dispersion, after ultrasonication, allow to stand at room temperature for adsorption, and then transfer the adsorbed slurry to a vacuum drying oven for vacuum drying to obtain functional nanocomposite powder with preloaded active ingredients. b. Add the above composite powder to the wood wax oil base in proportion, disperse it using a high-speed disperser, let it stand to defoam after dispersion, and then seal and mature it to obtain the modified wood wax oil with slow-release antibacterial and antifungal functions.

3. The environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder according to claim 2, characterized in that: The modified wood wax oil contains wood wax oil, tea polyphenols, tea saponins, and nanoporous titanium dioxide in a mass ratio of 100:1-20:1-20:1:

20.

4. The environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder according to claim 2, characterized in that: In step a, the reaction is ultrasonically dispersed for 20-30 minutes, allowed to stand for 12 hours for adsorption, and then vacuum dried at 40℃-50℃.

5. The environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder according to claim 1, characterized in that: In step b, the high-speed dispersion speed is 15,000-20,000 rpm, and the high-speed dispersion time is 10-20 minutes.

6. A method for preparing an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder, characterized in that, Includes an environmentally friendly, long-lasting anti-mildew and antibacterial interior wall putty powder as described in any one of claims 1-5, and the following steps: Step 1: Weigh the raw materials, including heavy calcium carbonate, lime, white cement, cellulose ether, lignocellulose, adhesive powder, and modified wood wax oil, according to the stated weight proportions. Step 2: Add heavy calcium carbonate, lime, white cement, cellulose ether, lignocellulose, adhesive powder, and modified wood wax oil to either a dry powder mixer or a vertical mixer and mix. Stir at 20-50 rpm for 15-25 minutes at room temperature until the mixture is homogeneous to obtain an environmentally friendly, long-lasting, mildew-proof, and antibacterial interior wall putty powder.