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

Abstract

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

Description

Technical Field

[0001] This invention relates to the field of antibacterial polypropylene technology, specifically to a long-lasting antibacterial PP composite material for cleaning brushes and its preparation method. Background Technology

[0002] In cleaning brush applications, traditional polypropylene (PP) materials are widely used due to their advantages such as chemical resistance and lightweight texture. However, the limitations of their antibacterial properties are becoming increasingly apparent. Conventional PP materials are prone to bacterial growth, which can cause problems such as discoloration and odor in the cleaning brush, and may also lead to secondary pollution. Especially in damp environments such as kitchens and bathrooms, the rapid proliferation of bacteria seriously threatens the user's health and affects the normal performance of the cleaning brush.

[0003] While antibacterial cleaning brushes are available on the market, most suffer from short-lived antibacterial effects. Some antibacterial agents may initially inhibit bacterial growth, but with frequent use, they rapidly migrate from the material to the surface and are gradually consumed, leading to a rapid decline in antibacterial performance and failing to meet the need for long-term protection. Furthermore, some antibacterial cleaning brushes contain excessive amounts of antibacterial agents to enhance their effectiveness, causing excessively rapid migration. This not only wastes resources but may also raise potential biosafety concerns, such as skin irritation or toxicity.

[0004] To address these issues, researching a long-lasting antibacterial PP composite material for cleaning brushes is of significant practical importance. This material needs to achieve a stable, long-term antibacterial effect while maintaining the basic performance of the cleaning brush. This can be achieved through precise control of the type and content of antibacterial agents and their synergistic effects with other additives, while simultaneously ensuring the safety and reliability of the material. This will meet the need for cleaning brushes to maintain their antibacterial properties and protect user health during long-term use. Summary of the Invention

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

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a long-lasting antibacterial PP composite material for cleaning brushes, comprising the following components in parts 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;

[0007] The antibacterial agent has the structure shown in Formula 1:

[0008] Formula 1;

[0009] Z1 is: O, S, N(H), C(H2).

[0010] Furthermore, the polypropylene resin is a homopolymer polypropylene with a melt index of 10-30 g / 10 min (230℃ / 2.16 kg) and an isotacticity of ≥90%.

[0011] Furthermore, the inorganic filler is barium sulfate.

[0012] Furthermore, the antibacterial agent is any one of the compounds shown in the following structures:

[0013] ;

[0014] .

[0015] Furthermore, the migration enhancer is sorbitol.

[0016] Furthermore, the antioxidant is Irganox 1010.

[0017] Furthermore, the structure of the Irganox 1010 is as follows: .

[0018] Furthermore, the lubricant is calcium stearate; the nucleating agent is sodium benzoate.

[0019] A method for preparing a long-lasting antibacterial PP composite material for cleaning brushes includes the following steps:

[0020] 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 until uniformly mixed to obtain a mixture;

[0021] S2. The mixture is fed into a twin-screw extruder for melt extrusion at an extrusion temperature of 180-220℃ and a screw speed of 200-400 rpm to obtain the extrudate;

[0022] S3. The extrudate is cooled in a water-cooling tank and then pelletized to obtain a long-lasting antibacterial PP composite material for cleaning brushes.

[0023] Furthermore, the extrusion temperature in S2 is specifically 190-210℃.

[0024] Furthermore, the screw speed of the twin-screw extruder in S2 is specifically 250-350 rpm.

[0025] The hydrophobic groups in the antibacterial agent of this invention can insert into the lipid bilayer of the cell membrane, disrupting membrane integrity. Cell membrane perforation leads to the leakage of intracellular proteins, nucleic acids, and other substances, ultimately killing bacteria. This mechanism is effective against both Gram-positive and Gram-negative bacteria. The long-lasting effect of the antibacterial agent relies 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 antibacterial agent molecules from the material interior to the surface; controlling the migration rate avoids rapid consumption caused by initial explosive release. Polyisobutylene, as a compatible elastomer, encapsulates the antibacterial agent through molecular entanglement; during the use of the cleaning brush, the polyisobutylene (PIB) phase gradually releases the antibacterial agent under mechanical friction, achieving on-demand supply.

[0026] The synergistic mechanism of components in a long-lasting antibacterial PP composite material for cleaning brushes described in this invention systematically solves three major technical problems of traditional PP materials for cleaning brushes: poor antibacterial performance, short-lived effect, and insufficient safety. Its core lies in:

[0027] 1) The antibacterial agent uses a specific hydrophobic structure to efficiently destroy the lipid bilayer of bacterial cell membranes, achieving broad-spectrum bactericidal action (covering Escherichia coli, Staphylococcus aureus, etc.) and directly enhancing initial antibacterial performance;

[0028] 2) Sorbitol, a migration enhancer, forms a hydrophilic microchannel network in the PP matrix, which works synergistically with the molecular entanglement and encapsulation of polyisobutylene elastomer to construct a dual control mechanism of "directional migration-on-demand release": sorbitol regulates the directional slow release of antibacterial agents, while polyisobutylene is dynamically released in response to external forces, significantly prolonging the antibacterial half-life and solving the problem of short-lived effect;

[0029] 3) The highly crystalline polypropylene matrix is ​​optimized by nucleating agents to form a dense structure, which inhibits bacterial adhesion. Barium sulfate filler enhances wear resistance and protects the antibacterial layer. Antioxidant Irganox 1010 prevents oxidation deactivation and toxic residues. Lubricant ensures uniform processing, which together improves safety and lifespan.

[0030] 4) The premixing, temperature-controlled extrusion and water-cooled curing processes in the preparation process work together to lock the interactive network of components, thereby improving the utilization rate of antibacterial agents and achieving long-lasting antibacterial effect, no secondary pollution and reliable biosafety in cleaning brush applications.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. Significantly Enhanced Antibacterial Properties: The long-lasting antibacterial PP (polypropylene) composite material for cleaning brushes of this invention exhibits outstanding antibacterial performance. Its unique antibacterial agent structure design effectively disrupts bacterial cell membranes, thereby achieving a broad-spectrum antibacterial effect. It effectively inhibits both Gram-positive and Gram-negative bacteria, solving the problem of insufficient antibacterial properties in traditional PP materials.

[0033] 2. Long-lasting and stable antibacterial effect: Through the synergistic effect of migration enhancers and polyisobutylene, this invention constructs a dual control mechanism of "directional migration-on-demand release." The migration enhancer forms microchannels in the PP matrix, promoting the directional migration of the antibacterial agent from the material's interior to the surface, while polyisobutylene encapsulates the antibacterial agent through molecular entanglement, allowing it to be gradually released through mechanical friction during the use of the cleaning brush. This design effectively avoids the initial explosive release and rapid consumption of the antibacterial agent, significantly extending the duration of the antibacterial effect.

[0034] 3. Material Performance Optimization: While ensuring antibacterial properties, this invention also focuses on improving the overall performance of the material. The highly crystalline polypropylene matrix, after optimization 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 deactivation and toxic residues; and the lubricant ensures uniformity during processing. These improvements collectively enhance the material's safety and service life, enabling it to maintain stable and reliable performance over long-term use. Attached Figure Description

[0035] Figure 1 The antibacterial agent 1 of the present invention 1 HNMR image. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely 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.

[0037] Synthesis example 1:

[0038] Synthesis of antibacterial agent 1:

[0039] ;

[0040] Step 1: Under a nitrogen atmosphere, add 20 g of starting material 1, 20.26 g of starting material 2, 4.92 g of concentrated sulfuric acid, and 250 g of tetrahydrofuran to the reaction system. Refrigerate at 80°C for 6 hours. After the reaction is complete, cool to room temperature, adjust the pH of the system to neutral with a 0.1 mol / L sodium bicarbonate aqueous solution, add 200 g of water, shake, allow to stand, separate the liquids, and retain the organic phase. Dry the organic phase with anhydrous magnesium sulfate, filter, evaporate to dryness, and perform silica gel column chromatography using a mixture of petroleum ether and ethyl acetate as eluent. Evaporate to dryness to obtain 27.21 g of intermediate 1.

[0041] Step 2: Under a nitrogen atmosphere, add 27.21 g of intermediate 1, 27.96 g of starting material 3, 0.8 g of tri-tert-butylphosphine, 0.27 g of palladium on carbon, 21.53 g of anhydrous potassium carbonate, and 300 g of toluene to the reaction system. Recirculate at 120°C for 12 hours. After the reaction, slightly lower the temperature and filter using diatomaceous earth. After cooling the filtrate to room temperature, wash three times with water, retaining the organic phase. Then extract the aqueous phase with ethyl acetate, combine the organic phases, dry the organic phase with anhydrous magnesium sulfate, filter, evaporate to dryness, and perform silica gel column chromatography using a mixture of petroleum ether and ethyl acetate as eluent. Evaporate to dryness to obtain 35.64 g of antibacterial agent 1. 1 HNMR image see Figure 1 .

[0042] Structural assessment:

[0043] MS(m / z) of intermediate 1: [M+H] + =350;

[0044] MS (m / z) of antibacterial agent 1: [M+H] + =568;

[0045] Antibacterial 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).

[0046] Synthesis Example 2-Synthesis Example 4:

[0047] In Synthesis Examples 2-4, antibacterial agents 2-4 were synthesized sequentially, following the same synthesis method as in Synthesis Example 1, except that raw material 2 was replaced; the rest remained the same as in Synthesis Example 1. Specific structures of raw material 2, antibacterial agents 2-4, and MS (m / z): [M+H] are detailed below. + The data is shown in Table 1.

[0048] Table 1. Structures of raw material 2, antibacterial agent 2 to antibacterial agent 4, and MS (m / z): [M+H] involved in Synthesis Examples 2-4 + data.

[0049]

[0050] Example 1:

[0051] Preparation of a long-lasting antibacterial PP composite material for cleaning brushes:

[0052] 1. In this embodiment, the components and mass fractions of the long-lasting antibacterial PP composite material are as follows:

[0053] Polypropylene resin: 70 parts (specifically, homopolymer polypropylene with a melt index of 20 g / 10 min (230℃ / 2.16 kg) and an isotacticity of 95%);

[0054] Polyisobutylene: 10 parts;

[0055] Inorganic filler: 20 parts (barium sulfate);

[0056] Antibacterial agent: 1.0 part (using antibacterial agent 1 prepared in Synthesis Example 1);

[0057] Migration enhancer: 5 parts (specifically sorbitol);

[0058] Antioxidant: 1.0 part (Irganox 1010, purchased from Guangzhou Dayin New Material Co., Ltd., item number 6683-19-8);

[0059] Lubricant: 1.0 part (calcium stearate);

[0060] Nucleating agent: 0.3 parts (sodium benzoate).

[0061] 2. In this embodiment, the preparation method of the long-lasting antibacterial PP composite material is as follows:

[0062] S1. Add all the above components (70 parts polypropylene resin, 10 parts polyisobutylene, 20 parts inorganic filler, 1.0 part antibacterial agent, 5 parts migration enhancer, 1.0 part antioxidant, 1.0 part lubricant, and 0.3 parts nucleating agent) to a high-speed mixer and premix for 10 minutes at room temperature. Set the mixer speed to 500 rpm to obtain the mixture.

[0063] S2. The mixture is fed into a twin-screw extruder (model: co-rotating type, L / D=40) for melt extrusion. The extrusion temperature is controlled at 200℃, specifically: 190℃ in the feeding section, 205℃ in the melting section, and 210℃ in the extrusion section. The screw speed is set to 300 rpm to obtain the extrudate.

[0064] S3. The extrudate is cooled in a water cooling tank (water temperature: 15±2℃, cooling time: 30 seconds) to rapidly solidify the melt. Then, the solidified extrudate is cut into particles with a particle size of about 3mm by a pelletizer to obtain a long-lasting antibacterial PP composite material for cleaning brushes.

[0065] Examples 2-4:

[0066] The preparation of a long-lasting antibacterial PP composite material for cleaning brushes is carried out by referring to the synthesis method of Example 1, except that the antibacterial agent is replaced sequentially with antibacterial agent 2-antibacterial agent 4 synthesized in Synthesis Examples 2-4, and the rest is the same as in Example 1.

[0067] Comparative Example 1:

[0068] The preparation of a long-lasting antibacterial PP composite material for cleaning brushes is carried out according to the synthesis method of Example 1, without the addition of antibacterial agent, and otherwise remains the same as in Example 1.

[0069] Comparative Example 2:

[0070] The preparation of a long-lasting antibacterial PP composite material for cleaning brushes is carried out by referring to the synthesis method of Example 1, except that the mass fraction of polyisobutylene is replaced with 25 parts, and the rest remains the same as in Example 1.

[0071] Comparative Example 3:

[0072] The preparation of a long-lasting antibacterial PP composite material for cleaning brushes is carried out by referring to the synthesis method of Example 1, except that the mass fraction of the inorganic filler is replaced with 5 parts, and the rest is the same as in Example 1.

[0073] Performance testing:

[0074] 1. Antibacterial properties: The long-lasting antibacterial PP composite material for cleaning brushes prepared in the examples and comparative examples was tested according to QB / T2591-2003 "Antibacterial Plastics - Evaluation and Test Methods of Antibacterial Properties". The test bacteria were Escherichia coli and Staphylococcus aureus, and the sterilization rate (%) after 24 hours was calculated. The data are shown in Table 2.

[0075] 2. Bending performance test: The long-lasting antibacterial PP composite material for cleaning brushes prepared in the examples and comparative examples was tested according to GB / T9341-2000 "Test method for bending performance of plastics". The data are shown in Table 2.

[0076] Table 2. Performance test data of a long-lasting antibacterial PP composite material for cleaning brushes prepared in the examples and comparative examples.

[0077]

[0078] The examples demonstrated excellent antibacterial properties and mechanical strength, while the comparative examples showed a clear trend of performance degradation. The antibacterial effect was highly sensitive to the presence of the active ingredient (it failed in the absence of the antibacterial agent), excessive plasticizer weakened the bactericidal rate and mechanical properties, and insufficient inorganic filler primarily impaired the material's rigidity. Overall, the balance and coordination of the components are key to achieving long-lasting antibacterial effects and structural stability.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

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

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 at 230℃ / 2.16 kg and an isotacticity ≥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 antioxidant is Irganox 1010.

6. 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.

7. A method for preparing a long-lasting antibacterial PP composite material for a cleaning brush according to any one of claims 1-6, characterized in that, Includes 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 until uniformly mixed to obtain a mixture; S2. The mixture is fed into a twin-screw extruder for melt extrusion at an extrusion temperature of 180-220℃ and a screw speed of 200-400 rpm to obtain the extrudate; S3. The extrudate is cooled in a water-cooling tank and then pelletized to obtain a long-lasting antibacterial PP composite material for cleaning brushes.

8. The method for preparing a long-lasting antibacterial PP composite material for cleaning brushes according to claim 7, characterized in that, The extrusion temperature in S2 is specifically 190-210℃.

9. A method for preparing a long-lasting antibacterial PP composite material for a cleaning brush according to claim 7, characterized in that, The screw speed of the twin-screw extruder in S2 is specifically 250-350 rpm.

Images