Polypropylene mildew-proof material as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene mildew-proof material as well as a preparation method and application thereof, and belongs to the technical field of indoor furniture. Comprising the following raw materials in parts by weight: 80-100 parts of polypropylene resin, 4-5 parts of nano zinc oxide, 0.5-1.5 parts of a dispersing agent, 2-6 parts of an organic mildew preventive, 5-8 parts of a compatilizer, 0.1-0.3 part of an initiator and 1.2-1.8 parts of an antioxidant. Wherein nano-zinc oxide is used as an inorganic mildew preventive, can destroy a mould cell structure through active oxygen generated by photocatalysis and a zinc ion dissolution effect, can improve the mildew resistance of the material, and is high in safety and good in heat resistance; wherein the organic mildew preventive contains a plurality of functional groups, so that the mildew resistance of the material is remarkably improved, and the organic mildew preventive is high in migration resistance and good in processing stability; in conclusion, the polypropylene material prepared by the invention has stable and efficient mildew-proof performance, and has important application value in the field of indoor furniture susceptible to mould erosion.

Description

Technical Field

[0001] This invention belongs to the field of indoor furniture technology, specifically relating to a polypropylene anti-mildew material, its preparation method, and its application. Background Technology

[0002] Polypropylene, as a general-purpose thermoplastic polymer material, has become one of the indispensable basic materials in the furniture industry due to its low density, strong chemical corrosion resistance, excellent processing fluidity and balanced mechanical properties. It is widely used in the manufacture of structural and decorative parts for chairs, storage boxes, tabletops and various household products.

[0003] Existing polypropylene materials lack polarity in their molecular structure and do not contain functional groups that inhibit microbial growth. In humid and hot environments, especially in high-humidity and high-heat applications like home bathrooms, they are susceptible to mold growth, leading to surface mildew, performance degradation, and shortened lifespan. Furniture products containing polypropylene may develop unsightly mold spots, damaging their appearance and reducing their usability and lifespan. More seriously, mold produces numerous spores and metabolic byproducts during its growth and reproduction, which can spread into indoor spaces through airflow. Inhaling these mold spores or coming into contact with mold metabolites can cause respiratory infections, skin allergies, asthma, and other health problems, posing a serious threat to the health of residents, especially the elderly, children, and people with allergies.

[0004] Currently, the industry typically modifies polypropylene materials by adding antifungal agents to improve their antifungal properties. However, commonly used organic antifungal agents suffer from insufficient heat stability, easily decomposing and failing under the high-temperature conditions of polypropylene processing, and readily migrating and precipitating from the matrix, resulting in a short antifungal effective period and difficulty in maintaining a long-lasting antibacterial effect. Therefore, there is an urgent need to solve these problems and invent a polypropylene material with stable antifungal properties to meet the higher application demands in the field of indoor furniture technology. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polypropylene anti-mildew material, its preparation method, and its application.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A polypropylene anti-mildew material comprises the following raw materials in parts by weight: 80-100 parts polypropylene resin, 4-5 parts nano zinc oxide, 0.5-1.5 parts dispersant, 2-6 parts organic anti-mildew agent, 5-8 parts compatibilizer, 0.1-0.3 parts initiator, and 1.2-1.8 parts antioxidant.

[0008] As a further technical solution, the dispersant is one or more of polyethylene wax, calcium stearate, zinc stearate and paraffin.

[0009] As a further technical solution, the compatibilizer is maleic anhydride-grafted polypropylene.

[0010] As a further technical solution, the initiator is one of benzoyl peroxide and di-tert-butyl peroxide.

[0011] As a further technical solution, the antioxidant is obtained by compounding the main antioxidant 1010 and the auxiliary antioxidant 168 in a mass ratio of 2:1.

[0012] As a further technical solution, the organic antifungal agent is prepared through the following steps:

[0013] A1. Assemble a three-necked round-bottom flask, an electric stirrer, a spherical reflux condenser, and a thermometer to construct a reaction apparatus. Add anhydrous acetonitrile to the flask and start stirring. Then, add 5-bromo-1-pentene and 5-chloro-2-methylisothiazolin-3-one in sequence. Slowly heat the reaction apparatus to 82-85°C under water bath conditions, maintaining the reaction system in a micro-reflux state. The reaction time is 7-8 hours. After the reaction is complete, perform post-processing to obtain the intermediate product.

[0014] A2. Assemble a reaction apparatus by combining a three-necked round-bottom flask, an electric stirrer, a spherical reflux condenser, and a thermometer. Add anhydrous N,N-dimethylformamide to the flask and start stirring. Then, add pentafluorophenol and sodium hydroxide powder in sequence. Heat the mixture to 40-50°C in a water bath and stir for 20-30 minutes. Then, slowly add the intermediate product. After the addition is complete, heat the mixture to 70-75°C and maintain the temperature for 6-7 hours. After the reaction is complete, perform post-treatment to obtain an organic antifungal agent.

[0015] As a further technical solution, the ratio of anhydrous acetonitrile, 5-bromo-1-pentene, and 5-chloro-2-methylisothiazolin-3-one in step A1 is 100mL:14.8g:14.9g.

[0016] As a further technical solution, the ratio of anhydrous N,N-dimethylformamide, pentafluorophenol, sodium hydroxide powder, and intermediate product in step A2 is 100mL:18.3g:4.0g:21.8g.

[0017] The reaction formula for preparing the organic antifungal agent according to this invention is as follows:

[0018]

[0019] As can be seen from the above reaction formula, in the process of preparing organic antifungal agent, step A1 introduces a double bond into the raw material containing the isothiazolinone structure through a quaternization reaction; step A2 introduces multiple fluorine elements into the intermediate product through a nucleophilic substitution reaction using fluorine-containing raw material, and finally obtains the antifungal agent.

[0020] In the organic antifungal agent prepared by this invention, isothiazolinone and fluorine play the main antifungal roles. The N-S bond in the isothiazolinone molecule is a highly active electrophilic center that can bind to key metabolic enzymes of mold, thereby inhibiting the activity of key metabolic enzymes in mold cells and improving the antifungal performance of the matrix. The introduced multiple fluorine elements can reduce the surface energy of the matrix and improve its water resistance, making it difficult for water molecules to wet and penetrate into the material's interior and surface. The material surface is also difficult to form a continuous water film that mold can utilize, thus limiting the mold's growth environment and inhibiting its growth. This synergistic effect with isothiazolinone significantly enhances the antifungal performance of the matrix.

[0021] The organic antifungal agent prepared by this invention not only provides antifungal properties but also introduces a benzene ring structure and an unsaturated double bond structure. The benzene ring structure is a rigid structure, which can improve the thermal stability of the antifungal agent during processing and make it less prone to decomposition and failure. Finally, the unsaturated double bond structure can be grafted onto the polypropylene matrix under the action of an initiator, thereby improving the migration resistance of the small molecule antifungal agent.

[0022] This invention also provides a method for preparing a polypropylene anti-mildew material, comprising the following steps:

[0023] B1. Pour nano zinc oxide, dispersant and polypropylene resin into a high-speed mixer and mix at 60-75℃ for 5-10 minutes to form a premix.

[0024] B2. The premix, organic mildew inhibitor, compatibilizer, initiator and antioxidant are fed into the feed hopper of a twin-screw extruder in sequence. After melting, shearing, mixing and degassing in the extruder, the material is extruded into strips through the die, cooled by water and granulated to obtain polypropylene mildew-resistant material.

[0025] As a further technical solution, the high-speed mixing speed is 1000-1200 rpm.

[0026] As a further technical solution, the temperatures of each section of the twin-screw extruder are as follows: Zone 1 170-175℃, Zone 2 180-185℃, Zone 3 190-195℃, Zone 4 195-200℃, Zone 5 195-200℃, and Die head 195-200℃.

[0027] The beneficial effects of this invention are:

[0028] 1. The addition of nano zinc oxide to the raw materials of this invention not only serves as an inorganic antifungal agent, but also destroys the mold cell structure through photocatalysis and the dissolution of zinc ions, thereby improving the antifungal properties of the material. Furthermore, it is highly safe and has good heat resistance.

[0029] 2. This invention produces a self-made organic antifungal agent. The antifungal agent contains a variety of functional groups, which significantly improves the antifungal properties of the material, and has strong migration resistance and good processing stability.

[0030] 3. This invention achieves highly efficient anti-mold performance by combining inorganic and organic anti-mold agents;

[0031] 4. The preparation principle of this invention is simple, the raw materials are readily available, and it is suitable for industrial production;

[0032] In summary, the polypropylene material prepared by this invention has stable and efficient anti-mildew properties, and has important application value in the field of indoor furniture that is susceptible to mold erosion. Detailed Implementation

[0033] 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.

[0034] Example 1

[0035] Preparation of organic antifungal agents:

[0036] A1. Assemble a reaction apparatus by combining a three-necked round-bottom flask, an electric stirrer, a spherical reflux condenser, and a thermometer. Add 100 mL of anhydrous acetonitrile to the flask and start stirring. Then, add 14.8 g of 5-bromo-1-pentene and 14.9 g of 5-chloro-2-methylisothiazolin-3-one sequentially. Slowly heat the reaction apparatus to 82 °C under water bath conditions, maintaining a micro-reflux state for 7 hours. After the reaction is complete, remove the water bath and allow the system to cool to room temperature. Disassemble the apparatus, distill the reaction solution under reduced pressure, dissolve it in ethyl acetate, wash three times with saturated brine, separate the liquid, and take the organic phase. Dry it with anhydrous magnesium sulfate, filter to remove the drying agent, distill under reduced pressure, and finally purify it by silica gel column chromatography (eluent: ethyl acetate / n-hexane = 1:4). Remove the eluent under reduced pressure to obtain the intermediate product.

[0037] A2. Assemble a reaction apparatus by combining a three-necked round-bottom flask, an electric stirrer, a spherical reflux condenser, and a thermometer. Add 100 mL of anhydrous N,N-dimethylformamide to the flask and start stirring. Then, add 18.3 g of pentafluorophenol and 4.0 g of sodium hydroxide powder sequentially. Heat the mixture to 40 °C in a water bath and stir for 20 min. Then, slowly add 21.8 g of the intermediate product. After the addition is complete, heat the mixture to 70 °C and maintain the temperature for 6 h. Once the reaction is complete, remove the water bath and allow the system to cool to room temperature. Disassemble the apparatus, wash with saturated brine, separate the liquids, and collect the organic phase. Dry the organic phase with anhydrous magnesium sulfate, filter to remove the desiccant, and then rotary evaporate the filtrate to obtain the crude product. Purify the crude product by silica gel column chromatography (eluent: ethyl acetate / petroleum ether = 1:5). Remove the eluent by rotary evaporation to obtain the organic antifungal agent.

[0038] A method for preparing a polypropylene anti-mildew material includes the following steps:

[0039] B1. Pour 4g of nano zinc oxide, 0.5g of polyethylene wax and 80g of polypropylene resin into a high-speed mixer and mix at 1000rpm for 5 minutes at 60℃ to form a premix.

[0040] B2. The premix, 2g of organic antifungal agent, 5g of maleic anhydride-grafted polypropylene, 0.1g of benzoyl peroxide and 1.2g of antioxidant (0.8g of primary antioxidant 1010 and 0.4g of secondary antioxidant 168) are sequentially fed into the feed hopper of a twin-screw extruder (the temperatures of each section of the twin-screw extruder are as follows: Zone 1 170℃, Zone 2 180℃, Zone 3 190℃, Zone 4 195℃, Zone 5 195℃, and the die head 195℃). After melting, shearing, mixing and degassing in the extruder, the material is extruded into strips through the die head, cooled by water at 15℃, and granulated to obtain polypropylene antifungal material.

[0041] Example 2

[0042] Preparation of organic antifungal agents:

[0043] A1. Assemble a reaction apparatus by combining a three-necked round-bottom flask, an electric stirrer, a spherical reflux condenser, and a thermometer. Add 100 mL of anhydrous acetonitrile to the flask and start stirring. Then, add 14.8 g of 5-bromo-1-pentene and 14.9 g of 5-chloro-2-methylisothiazolin-3-one sequentially. Slowly heat the reaction apparatus to 85 °C under water bath conditions, maintaining a micro-reflux state for 8 hours. After the reaction is complete, remove the water bath and allow the system to cool to room temperature. Disassemble the apparatus, distill the reaction solution under reduced pressure, dissolve it in ethyl acetate, wash three times with saturated brine, separate the liquid, and take the organic phase. Dry it with anhydrous magnesium sulfate, filter to remove the drying agent, distill under reduced pressure, and finally purify it by silica gel column chromatography (eluent: ethyl acetate / n-hexane = 1:4). Remove the eluent under reduced pressure to obtain the intermediate product.

[0044] A2. Assemble a reaction apparatus by combining a three-necked round-bottom flask, an electric stirrer, a spherical reflux condenser, and a thermometer. Add 100 mL of anhydrous N,N-dimethylformamide to the flask and start stirring. Then, add 18.3 g of pentafluorophenol and 4.0 g of sodium hydroxide powder sequentially. Heat the mixture to 50 °C in a water bath and stir for 30 min. Then, slowly add 21.8 g of intermediate product. After the addition is complete, heat the mixture to 75 °C and maintain the temperature for 7 h. Once the reaction is complete, remove the water bath and allow the system to cool to room temperature. Disassemble the apparatus, wash with saturated brine, separate the liquids, and collect the organic phase. Dry the organic phase with anhydrous magnesium sulfate, filter to remove the desiccant, and evaporate the filtrate by rotary evaporation to obtain the crude product. Purify the crude product by silica gel column chromatography (eluent: ethyl acetate / petroleum ether = 1:5), and evaporate the eluent by rotary evaporation to obtain the organic antifungal agent.

[0045] A method for preparing a polypropylene anti-mildew material includes the following steps:

[0046] B1. Pour 4.5g of nano zinc oxide, 1.0g of calcium stearate and 90g of polypropylene resin into a high-speed mixer and mix at 1200rpm for 10 minutes at 70℃ to form a premix.

[0047] B2. The premix, 4g of organic antifungal agent, 6.5g of maleic anhydride-grafted polypropylene, 0.2g of di-tert-butyl peroxide, and 1.8g of antioxidant (1.2g of primary antioxidant 1010 and 0.6g of secondary antioxidant 168) are sequentially fed into the feeding hopper of a twin-screw extruder (the temperatures of each section of the twin-screw extruder are as follows: Zone 1 175℃, Zone 2 185℃, Zone 3 195℃, Zone 4 200℃, Zone 5 200℃, and the die head 200℃). After melting, shearing, mixing, and degassing in the extruder, the material is extruded into strips through the die head, cooled by water at 20℃, and granulated to obtain polypropylene antifungal material.

[0048] Example 3

[0049] The only difference between this embodiment and Embodiment 2 is that, in this embodiment, a method for preparing a polypropylene anti-mildew material includes the following steps:

[0050] B1. Pour 5g of nano zinc oxide, 1.5g of zinc stearate and 100g of polypropylene resin into a high-speed mixer and mix at 1200rpm for 10 minutes at 75℃ to form a premix.

[0051] B2. The premix, 6g of organic antifungal agent, 8g of maleic anhydride-grafted polypropylene, 0.3g of di-tert-butyl peroxide, and 1.8g of antioxidant (1.2g of primary antioxidant 1010 and 0.6g of secondary antioxidant 168) are sequentially fed into the feed hopper of a twin-screw extruder (the temperatures of each section of the twin-screw extruder are as follows: Zone 1 175℃, Zone 2 185℃, Zone 3 195℃, Zone 4 200℃, Zone 5 200℃, and the die head 200℃). After melting, shearing, mixing, and degassing in the extruder, the material is extruded into strips through the die head, cooled by water at 15-20℃, and granulated to obtain polypropylene antifungal material.

[0052] Comparative Example 1

[0053] The only difference between this comparative example and Example 3 is that in this comparative example, an equal amount of 5-chloro-2-methylisothiazolin-3-one was used to replace the organic antifungal agent to prepare the antifungal material.

[0054] Comparative Example 2

[0055] This comparative example uses ordinary polypropylene material.

[0056] The anti-mildew performance of Examples 1, 2, and 3, and Comparative Examples 1 and 2 was tested:

[0057] The testing standard is GB / T 24128-2018. The mold growth on the sample surface is observed and graded according to the mold coverage area (0 grade: no mold, 5 grade: severe mold).

[0058] Examples 1, 2, 3 and Comparative Example 1 were stored at room temperature for 300 days, and their anti-mildew performance was measured using the same standard.

[0059] The measurement results are shown in Table 1:

[0060] Table 1

[0061]

[0062] As shown in Table 1, the anti-mold performance of the embodiments of the present invention is significantly improved compared with the comparative example after the addition of organic anti-mold agent. Moreover, the organic anti-mold agent has good stability and long anti-mold life. Therefore, the polypropylene material prepared by the present invention has important application value in the field of indoor furniture.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A polypropylene anti-mildew material, characterized in that, It includes the following raw materials in parts by weight: 80-100 parts polypropylene resin, 4-5 parts nano zinc oxide, 0.5-1.5 parts dispersant, 2-6 parts organic antifungal agent, 5-8 parts compatibilizer, 0.1-0.3 parts initiator and 1.2-1.8 parts antioxidant.

2. The polypropylene anti-mildew material according to claim 1, characterized in that, The organic antifungal agent is prepared through the following steps: A1. Add anhydrous acetonitrile to a flask, start stirring, and then add 5-bromo-1-pentene and 5-chloro-2-methylisothiazolin-3-one in sequence. React at 82-85℃ for 7-8 hours until the reaction is complete, and the intermediate product is obtained. A2. Add anhydrous N,N-dimethylformamide to a flask, start stirring, then add pentafluorophenol and sodium hydroxide powder in sequence. Stir at 40-50℃ for 20-30 min, then add the intermediate product. After the addition is complete, heat to 70-75℃ and react at a constant temperature for 6-7 h. Once the reaction is complete, an organic antifungal agent is obtained.

3. The polypropylene anti-mildew material according to claim 2, characterized in that, In step A1, the ratio of anhydrous acetonitrile, 5-bromo-1-pentene, and 5-chloro-2-methylisothiazolin-3-one is 100 mL: 14.8 g: 14.9 g.

4. The polypropylene anti-mildew material according to claim 2, characterized in that, In step A2, the ratio of anhydrous N,N-dimethylformamide, pentafluorophenol, sodium hydroxide powder, and intermediate product is 100 mL: 18.3 g: 4.0 g: 21.8 g.

5. The polypropylene anti-mildew material according to claim 1, characterized in that, The dispersant is one or more of polyethylene wax, calcium stearate, zinc stearate, and paraffin.

6. The polypropylene anti-mildew material according to claim 1, characterized in that, The compatibilizer is maleic anhydride-grafted polypropylene.

7. The polypropylene anti-mildew material according to claim 1, characterized in that, The initiator is one of benzoyl peroxide and di-tert-butyl peroxide.

8. The polypropylene anti-mildew material according to claim 1, characterized in that, The antioxidant is obtained by compounding the main antioxidant 1010 and the auxiliary antioxidant 168 in a mass ratio of 2:

1.

9. A method for preparing a polypropylene anti-mildew material, characterized in that, A polypropylene antifungal material according to any one of claims 1-8 is prepared by mixing polypropylene resin, nano zinc oxide and dispersant, then melt-blending with organic antifungal agent, compatibilizer, initiator and antioxidant, extruding and granulating.

10. The application of a polypropylene anti-mildew material according to any one of claims 1-8 or a polypropylene anti-mildew material prepared by the preparation method according to claim 9 in the field of indoor furniture technology.

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