Long-acting antibacterial PP composite material for cleaning brush and preparation method of long-acting antibacterial PP composite material

Abstract

The invention discloses a long-acting antibacterial PP composite material for a cleaning brush and a preparation method, and relates to the technical field of antibacterial PP. The invention relates to a long-acting antibacterial PP composite material for a cleaning brush. The long-acting antibacterial PP composite material is prepared from the following components in parts by mass: 60-80 parts of polypropylene resin, 5-15 parts of polyisobutene, 15-30 parts of inorganic filler, 0.5-2.0 parts of an antibacterial agent, 3-8 parts of a migration enhancer, 0.5-1.5 parts of an antioxidant, 0.5-1.5 parts of a lubricant and 0.1-0.5 part of a nucleating agent. The long-acting antibacterial PP composite material for the cleaning brush has excellent antibacterial performance. The antibacterial agent is unique in structural design and can efficiently destroy bacterial cell membranes, so that a broad-spectrum antibacterial effect is achieved. Gram-positive bacteria and Gram-negative bacteria can be effectively inhibited, and the problem that a traditional PP material is insufficient in antibacterial performance is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial polypropylene, and in particular to a long-lasting antibacterial PP composite material for cleaning brushes and a preparation method thereof. Background Art

[0002] Traditional polypropylene (PP) is widely used in cleaning brushes due to its chemical resistance and lightweight construction. However, its antibacterial properties are becoming increasingly limited. Bacteria easily grow on the surface of conventional PP, causing not only discoloration and odor problems on the brushes but also secondary contamination. This is especially true in humid environments like kitchens and bathrooms, where rapid bacterial growth poses a serious health threat to users and compromises the effectiveness of the brushes.

[0003] While antimicrobial cleaning brushes are available on the market, most suffer from a short-lived antimicrobial effect. While some antimicrobial agents can effectively inhibit bacterial growth in the initial stages of use, with frequent use, they tend to rapidly migrate from the interior of the material to the surface and be gradually consumed, causing the antimicrobial properties to rapidly degrade and failing to meet the need for long-term antimicrobial protection. Furthermore, some antimicrobial cleaning brushes contain excessive amounts of antimicrobial agents to enhance their effectiveness, causing them to migrate too quickly. This not only wastes resources but can also lead to potential biosafety issues, such as skin irritation or toxicity.

[0004] To address these issues, developing a long-lasting antimicrobial PP composite material for cleaning brushes is of great practical significance. This material must maintain the basic performance of the cleaning brush while meticulously controlling the type and content of the antimicrobial agent, as well as its synergistic effects with other additives, to achieve long-term, stable antimicrobial efficacy. This, combined with ensuring the material's safety and reliability, ensures that the cleaning brush maintains its antimicrobial properties over long periods of use and protects the user's health. Summary of the Invention

[0005] The purpose of the present invention is to address the problems in the prior art of polypropylene materials for cleaning brushes, such as poor antibacterial performance, short-term antibacterial effect and insufficient safety, and to provide a long-lasting antibacterial PP composite material for cleaning brushes, which has the characteristics of long-lasting antibacterial performance, safety and reliability, and meets the needs of long-term antibacterial protection.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a long-lasting antibacterial PP composite material for cleaning brushes, composed of the following components by weight: 60-80 parts of polypropylene resin, 5-15 parts of polyisobutylene, 15-30 parts of inorganic filler, 0.5-2.0 parts of antibacterial agent, 3-8 parts of migration enhancer, 0.5-1.5 parts of antioxidant, 0.5-1.5 parts of lubricant, and 0.1-0.5 parts of nucleating agent; The antibacterial agent has a structure shown in Formula 1: Formula 1; The Z1 is: O, S, N(H), C(H2).

[0007] Furthermore, the polypropylene resin is a homopolymer polypropylene with a melt index of 10-30 g / 10 min (230° C. / 2.16 kg) and an isotacticity of ≥90%.

[0008] Furthermore, the inorganic filler is barium sulfate.

[0009] Furthermore, the antibacterial agent is any one of the compounds shown in the following structures: ; .

[0010] Furthermore, the migration enhancer is sorbitol.

[0011] Furthermore, the antioxidant is Irganox 1010.

[0012] Furthermore, the structure of Irganox 1010 is: .

[0013] Furthermore, the lubricant is calcium stearate; the nucleating agent is sodium benzoate.

[0014] A method for preparing a long-lasting antibacterial PP composite material for a cleaning brush comprises the following steps: S1. The polypropylene resin, polyisobutylene, inorganic filler, antibacterial agent, migration enhancer, antioxidant, lubricant and nucleating agent are premixed in a mixer for 5-10 minutes and mixed to obtain a mixture; S2. The mixture was fed into a twin-screw extruder for melt extrusion, the extrusion temperature was 180-220 ℃, the screw speed was 200-400 rpm, and the extrudate was obtained; S3. The extrudate is cooled in a water-cooling tank and then pelletized to obtain a long-lasting antibacterial PP composite material for a cleaning brush.

[0015] Furthermore, the extrusion temperature in S2 is specifically 190-210°C.

[0016] Furthermore, the screw speed of the twin-screw extruder in S2 is specifically 250-350 rpm.

[0017] The hydrophobic groups in the antimicrobial agent described in the present invention can be inserted into the lipid bilayer of the cell membrane, destroying the integrity of the membrane. The perforation of the cell membrane leads to the leakage of intracellular proteins, nucleic acids and other substances, ultimately killing bacteria. This mechanism is effective for both Gram-positive and Gram-negative bacteria. The long-term effectiveness of the antimicrobial agent depends on the synergistic effect of the migration enhancer and polyisobutylene. Sorbitol, as a hydrophilic small molecule, forms microchannels in the PP matrix, promoting the directional migration of antimicrobial molecules from the interior of the material to the surface; controlling the migration rate to avoid rapid consumption caused by the initial explosive release. Polyisobutylene, as a compatible elastomer, wraps the antimicrobial agent through molecular entanglement; during the use of the cleaning brush, the polyisobutylene (PIB) phase is subjected to mechanical friction and gradually releases the antimicrobial agent, achieving on-demand supply.

[0018] The synergistic mechanism of the components in the long-lasting antibacterial PP composite material for cleaning brushes described in this invention systematically addresses the three major technical issues of traditional cleaning brush PP materials: poor antibacterial performance, short-lived effects, and insufficient safety. Its core lies in: 1) The antibacterial agent adopts a specific hydrophobic structure to efficiently destroy the lipid bilayer of bacterial cell membranes, achieving broad-spectrum bactericidal effect (covering Escherichia coli, Staphylococcus aureus, etc.), directly improving the initial antibacterial performance; 2) The migration enhancer sorbitol forms a hydrophilic microchannel network within the PP matrix, synergizing with the molecular entanglement and wrapping of the polyisobutylene elastomer to create a dual control mechanism of "directional migration and on-demand release": sorbitol regulates the directional sustained release of the antimicrobial agent, while polyisobutylene dynamically releases in response to external force, significantly extending the antimicrobial half-life and addressing the issue of short-lived effects. 3) The high-crystallinity polypropylene matrix is optimized with a nucleating agent to form a dense structure, inhibiting bacterial adhesion. The barium sulfate filler enhances wear resistance and protects the antibacterial layer. The antioxidant Irganox 1010 prevents oxidative inactivation and toxic residues. The lubricant ensures processing uniformity, which together improves safety and lifespan. 4) Premixing, temperature-controlled extrusion, and water-cooling solidification in the preparation process synergistically lock the component interaction network, thereby improving the utilization rate of the antimicrobial agent and achieving long-term antibacterial effect, no secondary pollution, and biosafety and reliability in the cleaning brush application.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly Improved Antimicrobial Performance: The long-lasting antimicrobial PP (polypropylene) composite material for cleaning brushes presented in this invention exhibits outstanding antimicrobial performance. Its unique antimicrobial agent structure effectively destroys bacterial cell membranes, achieving a broad-spectrum antimicrobial effect. It effectively inhibits both Gram-positive and Gram-negative bacteria, resolving the issue of insufficient antimicrobial performance in traditional PP materials.

[0020] 2. Long-lasting and stable antimicrobial effect: Through the synergistic effect of a migration enhancer and polyisobutylene, this invention establishes a dual control mechanism of "directional migration and on-demand release." The migration enhancer forms microchannels within the PP matrix, promoting the directional migration of the antimicrobial agent from the interior to the surface of the material. The polyisobutylene, on the other hand, encapsulates the antimicrobial agent through molecular entanglement, allowing it to be gradually released by mechanical friction during use. This design effectively avoids an initial burst of antimicrobial release and rapid depletion, significantly extending the duration of the antimicrobial effect.

[0021] 3. Optimized Material Performance: While maintaining antibacterial properties, this invention also focuses on improving the overall performance of the material. The high-crystallinity polypropylene matrix, optimized with a nucleating agent, forms a dense structure that effectively inhibits bacterial adhesion. The addition of barium sulfate filler enhances the material's wear resistance and protects the antibacterial layer. The use of the antioxidant Irganox 1010 prevents oxidative inactivation and toxic residues. Lubricants ensure uniform processing. These improvements collectively enhance the material's safety and service life, ensuring stable and reliable performance over long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 For the antibacterial agent 1 of the present invention 1 HNMR spectrum. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Synthesis example 1: Synthesis of antibacterial agent 1: ; The first step: under a nitrogen atmosphere, 20g of raw material 1, 20.26g of raw material 2, 4.92g of concentrated sulfuric acid and 250g of tetrahydrofuran were added to the reaction system, and the temperature was raised to 80°C and refluxed for 6 hours. After the reaction was completed, it was cooled to room temperature, the pH of the system was adjusted to neutral with 0.1mol / L sodium bicarbonate aqueous solution, 200g of water was added, shaken, allowed to stand, separated, and the organic phase was retained. The organic phase was dried over anhydrous magnesium sulfate, filtered, spin-dried, and subjected to silica gel column chromatography using a mixture of petroleum ether and ethyl acetate as eluent, spin-dried to obtain 27.21g of intermediate 1.

[0025] Step 2: Under a nitrogen atmosphere, add 27.21g of intermediate 1, 27.96g of raw material 3, 0.8g of tri-tert-butyl phosphine, 0.27g of palladium carbon, 21.53g of anhydrous potassium carbonate and 300g of toluene into the reaction system, heat to 120°C and reflux for 12 hours. After the reaction is completed, lower the temperature slightly and filter with diatomaceous earth. After the filtrate is cooled to room temperature, wash it three times with water and retain the organic phase. The aqueous phase is then extracted with ethyl acetate, and after the organic phases are combined, the organic phase is dried over anhydrous magnesium sulfate, filtered, and dried, and subjected to silica gel column chromatography. A mixture of petroleum ether and ethyl acetate is used as an eluent, and dried to obtain 35.64g of antibacterial agent 1. The antibacterial agent 1 1 HNMR diagram Figure 1 .

[0026] Structure identification: MS (m / z) of intermediate 1: [M+H] + =350; MS (m / z) of antibacterial agent 1: [M+H] + =568; Antimicrobial Agent 1 1 HNMR Chloroform-d: δ7.36-7.07(m, 9H), 6.98(dd, 1H), 6.83-6.71(m, 2H), 6.42(d, 1H), 5.1 7 (d, 1H), 4.95 (m, 1H), 3.16 (m, 1H), 2.13-1.93 (m, 2H), 1.88-1.54 (m, 6H), 1.35 (d, 9H).

[0027] Synthesis Example 2-Synthesis Example 4: Antibacterial agents 2 to 4 were synthesized in sequence in Synthesis Examples 2 to 4, referring to the synthesis method of Synthesis Example 1, replacing the raw material 2, and remaining the same as Synthesis Example 1. Specific structures of raw material 2, antibacterial agents 2 to 4, and MS (m / z): [M+H] + See Table 1 for data.

[0028] Table 1. Structure of raw material 2, antimicrobial agent 2-antimicrobial agent 4 involved in synthesis examples 2-4, MS (m / z): [M+H] + data.

[0029] Example 1: Preparation of a long-lasting antibacterial PP composite material for cleaning brushes: 1. In this embodiment, the components and mass fractions of the long-lasting antibacterial PP composite material are as follows: Polypropylene resin: 70 parts (specifically homopolymer polypropylene with a melt index of 20 g / 10 min (230°C / 2.16 kg) and an isotacticity of 95%); Polyisobutylene: 10 parts; Inorganic filler: 20 parts (barium sulfate); Antibacterial agent: 1.0 part (using antibacterial agent 1 prepared in Synthesis Example 1); Migration enhancer: 5 parts (specifically sorbitol); Antioxidant: 1.0 part (Irganox 1010, purchased from Guangzhou Dayin New Materials Co., Ltd., No. 6683-19-8); Lubricant: 1.0 part (calcium stearate); Nucleating agent: 0.3 parts (sodium benzoate).

[0030] 2. In this embodiment, the preparation method of the long-lasting antibacterial PP composite material is: S1. All the above components (70 parts of polypropylene resin, 10 parts of polyisobutylene, 20 parts of inorganic filler, 1.0 part of antibacterial agent, 5 parts of migration enhancer, 1.0 part of antioxidant, 1.0 part of lubricant, 0.3 parts of nucleating agent) were added to a high-speed mixer and premixed at room temperature for 10 minutes. The mixer speed was set to 500 rpm to obtain a mixture; S2. The mixture was fed into a twin-screw extruder (model: co-rotating, L / D = 40) for melt extrusion. The extrusion temperature was controlled at 200 ° C, specifically: feeding section 190 ° C, melting section 205 ° C, extrusion section 210 ° C, the screw speed was set to 300 rpm to obtain an extrudate; S3. The extrudate was cooled in a water-cooling trough (water temperature: 15±2°C, cooling time: 30 seconds) to rapidly solidify the melt. Subsequently, the solidified extrudate was cut into pellets with a particle size of approximately 3 mm using a pelletizer to obtain a long-lasting antibacterial PP composite material for a cleaning brush.

[0031] Example 2-Example 4: A long-lasting antibacterial PP composite material for a cleaning brush was prepared by referring to the synthesis method of Example 1, wherein the antibacterial agent was replaced with antibacterial agent 2 to antibacterial agent 4 synthesized in Synthesis Examples 2 to 4, respectively, and the rest remained the same as Example 1.

[0032] Comparative Example 1: A long-lasting antibacterial PP composite material for a cleaning brush was prepared by referring to the synthesis method of Example 1, except that the antibacterial agent was not added, and the rest of the preparation was the same as in Example 1.

[0033] Comparative Example 2: A long-lasting antibacterial PP composite material for a cleaning brush was prepared by referring to the synthesis method of Example 1, except that the mass fraction of polyisobutylene was replaced with 25 parts, and the rest remained the same as in Example 1.

[0034] Comparative Example 3: A long-lasting antibacterial PP composite material for a cleaning brush was prepared by referring to the synthesis method of Example 1, except that the mass fraction of the inorganic filler was replaced with 5 parts, and the rest remained the same as in Example 1.

[0035] Performance testing: 1. Antibacterial Performance: The long-lasting antibacterial PP composite materials for cleaning brushes prepared in the Examples and Comparative Examples were tested in accordance with QB / T2591-2003, "Antibacterial Plastics - Evaluation and Test Methods of Antibacterial Performance." The sterilization rates for Escherichia coli and Staphylococcus aureus were measured over 24 hours (%). See Table 2 for the data.

[0036] 2. Bending performance test: The long-lasting antibacterial PP composite materials for cleaning brushes prepared in the examples and comparative examples were tested with reference to the standard GB / T9341-2000 "Test method for bending performance of plastics". The data are shown in Table 2.

[0037] Table 2. Performance test data of a long-lasting antibacterial PP composite material for cleaning brushes prepared in Examples and Comparative Examples.

[0038] The examples demonstrated excellent antimicrobial performance and mechanical strength, while the comparative examples showed a clear trend of performance degradation. The antimicrobial effect is highly sensitive to the presence of active ingredients (ineffective in the absence of antimicrobial agents), while excessive amounts of plasticizers can weaken the sterilization rate and mechanical properties, while insufficient inorganic fillers primarily impair material rigidity. Overall, a balanced and coordinated approach among the various components is key to achieving both long-lasting antimicrobial efficacy and structural stability.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A long-lasting antibacterial PP composite material for cleaning brushes, characterized in that: The invention is composed of the following components in parts by mass: 60-80 parts of polypropylene resin, 5-15 parts of polyisobutylene, 15-30 parts of inorganic filler, 0.5-2.0 parts of antibacterial agent, 3-8 parts of migration enhancer, 0.5-1.5 parts of antioxidant, 0.5-1.5 parts of lubricant, and 0.1-0.5 parts of nucleating agent; The antibacterial agent has a structure shown in Formula 1: Formula 1; The Z1 is: O, S, N(H), C(H2).

2. The long-lasting antibacterial PP composite material for cleaning brushes according to claim 1, characterized in that: The polypropylene resin is a homopolymer polypropylene with a melt index of 10-30 g / 10 min (230° C. / 2.16 kg) and an isotacticity of ≥90%.

3. The long-lasting antibacterial PP composite material for cleaning brushes according to claim 1, characterized in that: The inorganic filler is barium sulfate.

4. The long-lasting antibacterial PP composite material for cleaning brushes according to claim 1, characterized in that: The antibacterial agent is any one of the compounds shown in the following structures: ； 。 5. The long-lasting antibacterial PP composite material for cleaning brushes according to claim 1, characterized in that: The migration enhancer is sorbitol.

6. The long-lasting antibacterial PP composite material for cleaning brushes according to claim 1, characterized in that: The antioxidant is Irganox 1010.

7. The long-lasting antibacterial PP composite material for cleaning brushes according to claim 1, characterized in that: The lubricant is calcium stearate; the nucleating agent is sodium benzoate.

8. A method for preparing a long-lasting antibacterial PP composite material for a cleaning brush according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. The polypropylene resin, polyisobutylene, inorganic filler, antibacterial agent, migration enhancer, antioxidant, lubricant and nucleating agent are premixed in a mixer for 5-10 minutes and mixed to obtain a mixture; S2. The mixture was fed into a twin-screw extruder for melt extrusion, the extrusion temperature was 180-220 ℃, the screw speed was 200-400 rpm, and the extrudate was obtained; S3. The extrudate is cooled in a water-cooling tank and then pelletized to obtain a long-lasting antibacterial PP composite material for a cleaning brush.

9. The method for preparing a long-lasting antibacterial PP composite material for cleaning brushes according to claim 8, characterized in that: The extrusion temperature in S2 is specifically 190-210°C.

10. The method for preparing a long-lasting antibacterial PP composite material for cleaning brushes according to claim 8, characterized in that: The screw speed of the twin-screw extruder in S2 is specifically 250-350 rpm.

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