Preparation process of antibacterial polypropylene material for blister packaging

Abstract

The invention relates to the technical field of polypropylene, and discloses a preparation process of an antibacterial polypropylene material for blister packaging, which comprises the following steps: reacting hexamethylene diisocyanate, 2, 2 '-diamino-N-methyldiethylamine and 1-chloro-3-(cardanol) oxy-2-propanol to obtain a quaternized cardanol copolymer; the preparation method comprises the following steps: adding 100 parts by weight of polypropylene resin, 4-8 parts by weight of quaternized cardanol copolymer and the like into a twin-screw extruder, performing melt extrusion, and pelletizing to obtain the antibacterial polypropylene material for blister packaging. The quaternized cardanol copolymer contains hydrophilic ureido, hydroxyl and quaternary ammonium salt groups, so that the hydrophilicity of polypropylene is improved, the antistatic performance is improved, and the impact strength is improved. In addition, the antibacterial quaternary ammonium salt group is contained, so that the polypropylene material shows excellent antibacterial performance. The practical application of polypropylene in antibacterial packaging materials of food, medicines and the like is favorably expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of polypropylene, and specifically to a preparation process of an antibacterial polypropylene material for blister packaging. Background Art

[0002] Blister packaging products are widely used in the packaging and transportation of products such as food, medical drugs, and health products. The materials of blister packaging products mainly include polypropylene, polyvinyl chloride, polyethylene terephthalate, etc. Among them, polypropylene has the advantages of being non-toxic and odorless, having a transparent appearance, low density, and light weight, and is widely used. Traditional polypropylene and its blister packaging products have problems such as poor antibacterial performance and poor antistatic performance, which are not conducive to their practical applications in food, medical drug packaging, etc.

[0003] Antibacterial agents for polypropylene mainly include nano-silver, nano-titanium dioxide, quaternary ammonium salts, etc. Organic quaternary ammonium salt antibacterial agents have good compatibility with polymer resins, low cost, and diverse preparation methods, and are an organic antibacterial agent with excellent performance. Chinese Patent CN112281309B discloses an antibacterial and radiation-proof non-woven fabric and its preparation method. By using the conductivity of silicon carbide fibers and the antistatic property of modified methyl cellulose, and at the same time using hexadecyl ether and trimethylammonium chloride to protonate the hydroxyl groups on the surface of bacterial cellulose, introducing quaternary ammonium salt groups or alkyl chain groups, the polypropylene non-woven fabric has good antistatic, antibacterial and other properties. However, the raw materials of this patent are relatively complex, and the mechanical properties of polypropylene products are not improved. Cardanol is a natural compound extracted from cashew nut shell oil, which is cheap and easy to obtain, has good biocompatibility, and strong high-temperature resistance. It can be made into toughening agents, emulsifiers, antibacterial agents, etc., and has important applications in polymer materials such as polypropylene, polyethylene, and epoxy resins. Summary of the Invention

[0004] The present invention solves the problems of poor antibacterial and antistatic properties of the antibacterial polypropylene material for blister packaging.

[0005] The technical solution of the present invention: A preparation process of an antibacterial polypropylene material for blister packaging:

[0006] (1) Add a solvent, hexamethylene diisocyanate (CAS registry number 822-06-0), 2,2'-diamino-N-methyldiethylamine (CAS registry number 4097-88-5) to a reaction vessel equipped with a condenser reflux tube, and carry out a polymerization reaction at 45 - 70 °C with stirring for 2 - 4 h. Remove the solvent by vacuum distillation, wash with ethanol, and dry to obtain a tertiary amine-based polyurea copolymer.

[0007] (2) Add N,N-dimethylformamide, tertiary amine-based polyurea copolymer, and 1-chloro-3-(cardanol)oxy-2-propanol to the reaction vessel, stir and react at 100-130 °C for 18-36 h, remove N,N-dimethylformamide by vacuum distillation, wash with dichloromethane, and dry to obtain the quaternized cardanol copolymer. The reaction formula is:

[0008]

[0009] In the reaction formula, n is 25-31.

[0010] (3) Add 100 parts by weight of polypropylene resin, 4-8 parts by weight of quaternized cardanol copolymer, and 0.2-0.4 parts by weight of antioxidant to a twin-screw extruder, melt extrude and pelletize to obtain an antibacterial polypropylene material for thermoformed packaging.

[0011] Preferably, the solvent in (1) is dichloromethane, tetrahydrofuran, toluene or N,N-dimethylformamide.

[0012] Preferably, the dosage of hexamethylene diisocyanate in (1) is 100 parts by weight, and the dosage of 2,2'-diamino-N-methyldiethylamine is 65-75 parts by weight.

[0013] Preferably, the dosage of the tertiary amine-based polyurea copolymer in (2) is 100 parts by weight, and the dosage of 1-chloro-3-(cardanol)oxy-2-propanol is 80-140 parts by weight.

[0014] Preferably, the temperatures of each section of the twin-screw extruder in (3) are 150-190 °C, and the screw speed is 40-80 r / min.

[0015] Preferably, the antioxidant in (3) is a hindered phenol antioxidant or a phosphite antioxidant.

[0016] The technical effect of the present invention: Polymerize hexamethylene diisocyanate and 2,2'-diamino-N-methyldiethylamine to obtain a tertiary amine-based polyurea copolymer. Its tertiary amine group then undergoes a quaternization reaction with the chlorine atom of 1-chloro-3-(cardanol)oxy-2-propanol to obtain a quaternized cardanol copolymer. Finally, it is melt-blended with polypropylene to obtain an antibacterial polypropylene material for thermoformed packaging. The main chain of this quaternized cardanol copolymer contains a urea-based hydrophilic group, and at the same time, the side chain contains hydrophilic hydroxyl and quaternary ammonium salt groups. Adding it to polypropylene is beneficial to improving the hydrophilicity of polypropylene, enabling polypropylene to adsorb moisture in the air and form a conductive water molecule film on the surface, thereby reducing the surface resistivity and improving the antistatic performance.

[0017] The side chain of the quaternized cardanol copolymer of the present invention contains a quaternary ammonium salt group with antibacterial properties, which can effectively kill and inhibit bacterial microorganisms, enabling the polypropylene material to exhibit excellent antibacterial performance. This is conducive to expanding the practical applications of polypropylene in antibacterial packaging materials such as food and medicine.

[0018] The side chain of the quaternized cardanol copolymer of the present invention contains a large number of cardanol alkyl long chains, which has good compatibility with polypropylene. When added to polypropylene, it has little impact on its mechanical properties. At the same time, a large number of alkyl long chains form physical entanglement with the polypropylene molecular chains, which can increase the crosslinking degree between the polypropylene molecular chains, facilitating the improvement of impact strength and mechanical properties. Detailed implementation mode

[0019] Although the specific implementation modes of the present invention are described above, they do not limit the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made without creative efforts by those skilled in the art are still within the protection scope of the present invention.

[0020] The following polypropylene resin, model Yuanye 990, is purchased from Maoming Yuanye Plastic Products Co., Ltd.

[0021] According to the method in the journal "Henan Chemical Industry", Volume 30 in 2013, the literature "Process Technology Research on Cardanol Glycidyl Ether", prepare 1-chloro-3-(cardanol)oxy-2-propanol. Add 3 g (about 10 mmol) of cardanol, 50 mmol of epichlorohydrin, and 0.06 g of catalyst benzyltriethylammonium chloride to the reaction vessel, react at 80 °C for 4 h, add water for dilution, extract and wash with dichloromethane. After separation, the dichloromethane organic phase is distilled under reduced pressure and separated by a chromatography column. The eluent is a petroleum ether and ethyl acetate solution with a volume ratio of 10:1 to obtain 1-chloro-3-(cardanol)oxy-2-propanol. The structural formula is n is 25 - 31.

[0022] According to the method in the master's thesis of Tianjin University of Technology "Synthesis and Antibacterial Properties of Quaternized Cardanol", prepare brominated cardanol ether. Add 25 mL of isopropanol, 1.17 g (6.25 mmol) of 1,2-dibromoethane, and 3.45 g (25 mmol) of potassium carbonate to the reaction vessel equipped with a condenser reflux tube, and dropwise add 10 mL of an isopropanol solution containing 0.3 g (about 1 mmol) of cardanol. React at 90 °C for 12 h. Filter, distill the filtrate under reduced pressure, and separate by a chromatography column. The eluent is a petroleum ether and ethyl acetate solution with a volume ratio of 10:1 to obtain brominated cardanol ether. The structural formula is: n is 27 - 31.

[0023] Example 1

[0024] (1) Add 200 mL of tetrahydrofuran, 40 g of hexamethylene diisocyanate, and 28 g of 2,2'-diamino-N-methyldiethylamine to a reaction vessel equipped with a condensation reflux tube. Stir at 60 °C for 3 h for a polymerization reaction. Remove the solvent by vacuum distillation, wash with ethanol, and dry to obtain a tertiary amino polyurea copolymer.

[0025] (2) Add 300 mL of N,N-dimethylformamide, 50 g of the tertiary amino polyurea copolymer, and 55 g of 1-chloro-3-(cardanol)oxy-2-propanol to a reaction vessel. Stir at 100 °C for 36 h for a reaction. Remove N,N-dimethylformamide by vacuum distillation, wash with dichloromethane, and dry to obtain a quaternized cardanol copolymer.

[0026] (3) Add 10 kg of polypropylene resin, 400 g of the quaternized cardanol copolymer, and 40 g of the hindered phenol antioxidant 1010 to a twin-screw extruder. The temperatures of each section are 150 °C, 175 °C, 190 °C, 190 °C, and 185 °C, and the screw speed is 50 r / min. Melt extrude and pelletize to obtain an antibacterial polypropylene material for blister packaging.

[0027] Example 2

[0028] (1) Add 300 mL of dichloromethane, 40 g of hexamethylene diisocyanate, and 26 g of 2,2'-diamino-N-methyldiethylamine to a reaction vessel equipped with a condensation reflux tube. Stir at 40 °C for 4 h for a polymerization reaction. Remove the solvent by vacuum distillation, wash with ethanol, and dry to obtain a tertiary amino polyurea copolymer.

[0029] (2) Add 400 mL of N,N-dimethylformamide, 50 g of the tertiary amino polyurea copolymer, and 70 g of 1-chloro-3-(cardanol)oxy-2-propanol to a reaction vessel. Stir at 120 °C for 24 h for a reaction. Remove N,N-dimethylformamide by vacuum distillation, wash with dichloromethane, and dry to obtain a quaternized cardanol copolymer.

[0030] (3) Add 10 kg of polypropylene resin, 500 g of the quaternized cardanol copolymer, and 28 g of the phosphite antioxidant 168 to a twin-screw extruder. The temperatures of each section are 150 °C, 175 °C, 190 °C, 190 °C, and 185 °C, and the screw speed is 80 r / min. Melt extrude and pelletize to obtain an antibacterial polypropylene material for blister packaging.

[0031] Example 3

[0032] (1) Add 200 mL of N,N-dimethylformamide, 40 g of hexamethylene diisocyanate, and 28 g of 2,2'-diamino-N-methyldiethylamine to a reaction vessel equipped with a condensation reflux pipe. Stir at 70 °C for a polymerization reaction for 2 h. Remove the solvent by vacuum distillation, wash with ethanol, and dry to obtain a tertiary amino polyurea copolymer.

[0033] (2) Add 300 mL of N,N-dimethylformamide, 50 g of the tertiary amino polyurea copolymer, and 40 g of 1-chloro-3-(cardanol)oxy-2-propanol to a reaction vessel. Stir and react at 120 °C for 24 h. Remove N,N-dimethylformamide by vacuum distillation, wash with dichloromethane, and dry to obtain a quaternized cardanol copolymer.

[0034] (3) Add 10 kg of polypropylene resin, 650 g of the quaternized cardanol copolymer, and 30 g of phosphite antioxidant 168 to a twin-screw extruder. The temperature of each section is 150 °C, 175 °C, 190 °C, 190 °C, 185 °C, and the screw speed is 80 r / min. Melt extrude and pelletize to obtain an antibacterial polypropylene material for blister packaging.

[0035] Example 4

[0036] (1) Add 200 mL of toluene, 40 g of hexamethylene diisocyanate, and 30 g of 2,2'-diamino-N-methyldiethylamine to a reaction vessel equipped with a condensation reflux pipe. Stir at 65 °C for a polymerization reaction for 3 h. Remove the solvent by vacuum distillation, wash with ethanol, and dry to obtain a tertiary amino polyurea copolymer.

[0037] (2) Add 400 mL of N,N-dimethylformamide, 50 g of the tertiary amino polyurea copolymer, and 55 g of 1-chloro-3-(cardanol)oxy-2-propanol to a reaction vessel. Stir and react at 130 °C for 18 h. Remove N,N-dimethylformamide by vacuum distillation, wash with dichloromethane, and dry to obtain a quaternized cardanol copolymer.

[0038] (3) Add 10 kg of polypropylene resin, 800 g of the quaternized cardanol copolymer, and 40 g of hindered phenol antioxidant 1010 to a twin-screw extruder. The temperature of each section is 150 °C, 175 °C, 190 °C, 190 °C, 185 °C, and the screw speed is 40 r / min. Melt extrude and pelletize to obtain an antibacterial polypropylene material for blister packaging.

[0039] Comparative Example 1

[0040] (1) Add 10 kg of polypropylene resin and 40 g of hindered phenol antioxidant 1010 to a twin-screw extruder. The temperature of each section is 150 °C, 175 °C, 190 °C, 190 °C, 185 °C, and the screw speed is 50 r / min. Melt and extrude, then pelletize to obtain the polypropylene material for blister packaging.

[0041] Comparative Example 2

[0042] (1) Add 10 kg of polypropylene resin, 400 g of tertiary amine-based polyurea copolymer (prepared in Example 1), and 40 g of hindered phenol antioxidant 1010 to a twin-screw extruder. The temperature of each section is 150 °C, 175 °C, 190 °C, 190 °C, 185 °C, and the screw speed is 50 r / min. Melt and extrude, then pelletize to obtain the polypropylene material for blister packaging.

[0043] Comparative Example 3

[0044] (1) Add 300 mL of N,N-dimethylformamide, 50 g of tertiary amine-based polyurea copolymer (prepared in Example 1), and 55 g of benzyl chloride to a reaction vessel. Stir and react at 100 °C for 36 h. Distill off N,N-dimethylformamide under reduced pressure, wash with dichloromethane, and dry to obtain the quaternized copolymer.

[0045] (2) Add 10 kg of polypropylene resin, 400 g of quaternized copolymer, and 40 g of hindered phenol antioxidant 1010 to a twin-screw extruder. The temperature of each section is 150 °C, 175 °C, 190 °C, 190 °C, 185 °C, and the screw speed is 50 r / min. Melt and extrude, then pelletize to obtain the antibacterial polypropylene material for blister packaging.

[0046] Comparative Example 4

[0047] (1) Add 300 mL of N,N-dimethylformamide, 50 g of tertiary amine-based polyurea copolymer (prepared in Example 1), and 55 g of brominated cardanol ether to a reaction vessel. Stir and react at 100 °C for 36 h. Distill off N,N-dimethylformamide under reduced pressure, wash with dichloromethane, and dry to obtain the quaternized cardanol copolymer.

[0048] (2) Add 10 kg of polypropylene resin, 400 g of quaternized cardanol copolymer, and 40 g of hindered phenol antioxidant 1010 to a twin-screw extruder. The temperature of each section is 150 °C, 175 °C, 190 °C, 190 °C, 185 °C, and the screw speed is 50 r / min. Melt and extrude, then pelletize to obtain the antibacterial polypropylene material for blister packaging.

[0049] Manufacture the polypropylene material into specimens by an injection molding machine, and the injection molding temperature is 210 °C.

[0050] The simple supported beam impact strength of the specimen was tested according to the method of GB / T 1043-1-2008.

[0051] The surface resistivity of the specimen was tested using a high resistance meter. The test temperature was 25 °C and the relative humidity was 50%.

[0052] The antibacterial performance was tested according to the method of QB / T 2591-2003. The test bacterial strains were Escherichia coli and Staphylococcus aureus respectively. The antibacterial rate R = (B - C) / B × 100%. B is the average number of recovered bacteria (cfu / sheet) of the blank control sample (comparative example 1). C is the average number of recovered bacteria (cfu / sheet) of the antibacterial plastic sample.

[0053] Table 1 Performance Test of Polypropylene Materials

[0054]

[0055]

[0056] After testing, compared with comparative example 1, the polypropylene materials of examples 1-4 have lower surface resistivity, which is beneficial to improving the antistatic performance of the materials. At the same time, they show good antibacterial performance against Escherichia coli and Staphylococcus aureus. The main reason is that the main chain of the quaternized cardanol copolymer added contains a urea group The hydrophilic group, while the side chain contains hydrophilic hydroxyl and quaternary ammonium salt groups. When added to polypropylene, it is beneficial to improve the hydrophilicity of polypropylene, enabling polypropylene to adsorb moisture in the air and form a conductive water molecule film on the surface, thereby reducing the surface resistivity and improving the antistatic performance. And the side chain of the copolymer contains antibacterial quaternary ammonium salt groups, which can effectively kill and inhibit bacteria and microorganisms, showing excellent antibacterial performance. The side chain of the copolymer contains a large number of cardanol alkyl long chains, which have good compatibility with polypropylene. When added to polypropylene, it has little effect on its mechanical properties. The impact strength of example 1 has little difference from that of comparative example 1. At the same time, a large number of alkyl long chains form physical entanglement with the polypropylene molecular chains, which can improve the crosslinking degree between polypropylene molecular chains and is beneficial to improving the mechanical properties. The polypropylene materials of examples 2-3 show better impact strength.

[0057] Compared with comparative example 2, only the tertiary amine-based polyurea copolymer was added, which does not contain hydrophilic quaternary ammonium salt and hydroxyl groups, resulting in lower hydrophilicity of the polypropylene material than that of example 1, larger surface resistivity, and poor antistatic effect. And it does not improve the antibacterial performance of the polypropylene material. At the same time, the side chain of the tertiary amine-based polyurea copolymer does not contain alkyl long chains, and its compatibility with polypropylene is poor, resulting in a significant decrease in the impact strength of the material.

[0058] Comparative Example 3 uses the quaternization reaction of the chlorine atom of conventional benzyl chloride with the tertiary amine group of the tertiary amine-based polyurea copolymer. The resulting quaternized polymer does not contain hydrophilic hydroxyl groups, resulting in a lower hydrophilicity of the polypropylene material than that of Example 1, a relatively large surface resistivity, and poor antistatic effect. Moreover, the side chain of the quaternized polymer does not contain an alkyl long chain, and the compatibility with polypropylene is poor, resulting in a significant decrease in the impact strength of the material.

[0059] Comparative Example 4 uses the quaternization reaction of the bromine atom of conventional brominated cardanol-based ether with the tertiary amine group of the tertiary amine-based polyurea copolymer. The resulting quaternized cardanol copolymer does not contain hydrophilic hydroxyl groups, resulting in a lower hydrophilicity of the polypropylene material than that of Example 1, a relatively large surface resistivity, and poor antistatic effect.

Claims

1. A preparation process of an antibacterial polypropylene material for blister packaging, characterized in that, The preparation process is as follows: (1) Add N,N-dimethylformamide, tertiary amine-based polyurea copolymer, and 1-chloro-3-(cardanol)oxy-2-propanol into a reaction vessel, stir and react, perform vacuum distillation, wash, and dry to obtain a quaternized cardanol copolymer; (2) Add 100 parts by weight of polypropylene resin, 4 - 8 parts by weight of quaternized cardanol copolymer, and 0.2 - 0.4 parts by weight of antioxidant into a twin-screw extruder, melt extrude and pelletize to obtain an antibacterial polypropylene material for blister packaging.

2. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 1, characterized in that, The reaction temperature in (1) is 100 - 130 °C, and the reaction time is 18 - 36 h.

3. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 1, characterized in that, The dosage of the tertiary amine-based polyurea copolymer in (1) is 100 parts by weight, and the dosage of 1-chloro-3-(cardanol)oxy-2-propanol is 80 - 140 parts by weight.

4. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 3, characterized in that, The preparation process of the tertiary amine-based polyurea copolymer is: Add a solvent, hexamethylene diisocyanate, and 2,2'-diamino-N-methyldiethylamine into a reaction vessel, carry out a polymerization reaction, perform vacuum distillation, wash, and dry to obtain the tertiary amine-based polyurea copolymer.

5. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 4, characterized in that, The solvent is dichloromethane, tetrahydrofuran, toluene, or N,N-dimethylformamide.

6. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 4, characterized in that, The dosage of hexamethylene diisocyanate is 100 parts by weight, and the dosage of 2,2'-diamino-N-methyldiethylamine is 65 - 75 parts by weight.

7. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 4, characterized in that, The polymerization reaction temperature is 45 - 70 °C, and the reaction time is 2 - 4 h.

8. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 1, characterized in that, The temperature of each section of the twin-screw extruder in (2) is 150 - 190 °C, and the screw speed is 40 - 80 r / min.

9. The preparation process of the antibacterial polypropylene material for blister packaging according to claim 1, characterized in that, The antioxidant in (2) is a hindered phenol antioxidant or a phosphite antioxidant.

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