Polypropylene bio-based antibacterial composite film as well as application and preparation process thereof

Abstract

The invention provides a polypropylene bio-based antibacterial composite film and application and a preparation process thereof, the composite film adopts a multi-layer composite structure, the composite film comprises an upper surface layer, a core layer and a lower surface layer which are arranged in sequence, the upper surface layer comprises the following raw material components in percentage by weight: 97-99.5% of co-polypropylene resin and 0.5-5% of an anti-blocking agent, and the core layer comprises the following raw material components in percentage by weight; the core layer is prepared from the following raw material components in percentage by weight: 99 to 99.5 percent of homo-polypropylene resin and 0.5 to 1 percent of antistatic agent; the lower surface layer is prepared from the following raw material components in percentage by weight: 85 to 98.4 percent of co-polypropylene resin, 0.5 to 5 percent of anti-blocking agent, 0.1 to 10 percent of modified compatilizer and 1 to 10 percent of antibacterial master batch. On the basis that performance parameters are guaranteed, good antibacterial and bactericidal functions are achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of composite films, and specifically, to a polypropylene bio-based antibacterial composite film, its application and preparation process. Background Art

[0002] Many existing composite films are used in the field of food packaging, but the composite films used in the field of food packaging often do not have the function of antibacterial and sterilization. Summary of the Invention

[0003] The purpose of the embodiments of the present disclosure is to provide a polypropylene bio-based antibacterial composite film and a preparation process to solve the above problems existing in the prior art.

[0004] To solve the above technical problems, on the one hand, an embodiment of the present disclosure provides a polypropylene bio-based antibacterial composite film, which adopts a multi-layer composite structure, including an upper surface layer, a core layer and a lower surface layer arranged in sequence. The upper surface layer includes components with the following raw material percentages: 97-99.5% of copolymerized polypropylene resin and 0.5-5% of anti-blocking agent. The core layer includes components with the following raw material percentages: 99-99.5% of homopolymerized polypropylene resin and 0.5-1% of antistatic agent; the lower surface layer includes components with the following raw material percentages: 85-98.4% of copolymerized polypropylene resin, 0.5-5% of anti-blocking agent, 0.1-10% of modified compatibilizer and 1-10% of antibacterial masterbatch.

[0005] In some embodiments, the copolymerized polypropylene resin is at least one of binary copolymerized polypropylene and ternary copolymerized polypropylene; wherein, the density of polypropylene is 0.90-0.98 g / cm 3 , and the melt index is 2-10 g / 10 min under the test conditions of a temperature of 230 °C and a load of 2.16 kg.

[0006] In some embodiments, the antibacterial masterbatch includes 10-20% of bio-based antibacterial agent, 0.05-1% of compatibilizer and 80-90% of matrix resin.

[0007] In some embodiments, the bio-based antibacterial agent includes at least one of flavonoids and their derivatives, phenolic acid extracts, tannin compounds, and monoterpene extracts;

[0008] In some embodiments, the modified compatibilizer includes a compatibilizer and a matrix resin.

[0009] In some embodiments, the compatibilizer is at least one of maleic anhydride grafted polyolefin, polyolefin elastomer, peroxide compatibilizer, acrylic acid grafted to polyolefin resin, and glycidyl methacrylate.

[0010] In some embodiments, the matrix resin is polypropylene or polyethylene.

[0011] One aspect of the embodiments of the present disclosure provides an application of a polypropylene bio-based antibacterial composite film in inhibiting bacteria. The polypropylene bio-based antibacterial composite film is the polypropylene bio-based antibacterial composite film of any one of the above, and the bacteria can be at least Gram-positive bacteria and Gram-negative bacteria.

[0012] One aspect of the embodiments of the present disclosure provides a preparation process of a polypropylene bio-based antibacterial composite film. The polypropylene bio-based antibacterial composite film is the polypropylene bio-based antibacterial composite film of any one of claims 1-7. The preparation process includes the following steps:

[0013] Step 1: Uniformly mix the raw materials of each component in each of the above layers, then perform melt co-extrusion and cooling to form a thick sheet;

[0014] Step 2: Pass the thick sheet formed in Step 1 through a longitudinal stretching device and a transverse stretching device in sequence to perform a biaxial stretching process to generate a film;

[0015] Step 3: Perform corona treatment on the film stretched in Step 2 to increase the surface tension;

[0016] Step 4: Wind the film processed in Step 3 into a master roll and perform aging treatment;

[0017] Step 5: Cut the film processed in Step 4 into products according to requirements.

[0018] In some embodiments, in the step of uniformly mixing the raw materials of each component in each of the above layers, then performing melt co-extrusion and cooling to form a thick sheet, the lower surface layer is extruded through a first auxiliary extruder, and its outlet temperature is 245-250 °C; the core layer is extruded through a main extruder, and its outlet temperature is 245-250 °C; the upper surface layer is extruded through a second auxiliary extruder, and its outlet temperature is 245-250 °C and the die head temperature is 245-250 °C; in addition, the temperature of the cooling casting sheet device is controlled at 75-80 °C; in the step of passing the thick sheet formed in Step 1 through a longitudinal stretching device and a transverse stretching device in sequence to perform a biaxial stretching process to generate a film, the temperature of the rollers in the longitudinal stretching device is controlled as follows: preheating zone 85-90 °C, stretching zone 110-115 °C, shaping zone 90-95 °C, stretching ratio 4.5-5.5; the temperature of the rollers in the transverse stretching device is controlled as follows: preheating zone 150-155 °C, stretching zone 125-130 °C, shaping zone 95-100 °C, stretching ratio 6-8.

[0019] On the basis of ensuring the performance parameters, the embodiments of the present disclosure also have good antibacterial and bactericidal functions. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of the polypropylene bio-based antibacterial composite film in the embodiments of the present disclosure. Detailed implementation manners

[0022] Reference is made herein to the various aspects and features of the present disclosure with reference to the accompanying drawings.

[0023] It should be understood that various modifications can be made to the embodiments applied herein. Therefore, the above description should not be regarded as a limitation, but only as an example of the embodiments. Those skilled in the art will think of other modifications within the scope and spirit of the present disclosure.

[0024] The accompanying drawings included in and forming a part of the specification illustrate the embodiments of the present disclosure, and together with the general description of the present disclosure given above and the detailed description of the embodiments given below are used to explain the principles of the present disclosure.

[0025] These and other features of the present disclosure will become apparent from the following description of the preferred forms of the embodiments given by way of non-limiting examples with reference to the accompanying drawings.

[0026] It should also be understood that although the present disclosure has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present disclosure, which have the features as described in the claims and thus are all within the protection scope defined thereby.

[0027] When combined with the accompanying drawings, in view of the following detailed description, the above and other aspects, features and advantages of the present disclosure will become more apparent.

[0028] Hereinafter, the specific embodiments of the present disclosure will be described with reference to the accompanying drawings; however, it should be understood that the embodiments applied are only examples of the present disclosure and can be implemented in various ways. Well-known and / or repetitive functions and structures are not described in detail to avoid unnecessary or redundant details from obscuring the present disclosure. Therefore, the specific structural and functional details applied herein are not intended to be limiting, but only as a basis and representative basis for the claims to teach those skilled in the art to combine substantially arbitrarily.

[0029] The first embodiment of the present disclosure provides a polypropylene bio-based antibacterial composite film, which adopts a multi-layer composite structure and is prepared by polypropylene modified resin and a biaxial stretching process, as Figure 1 shown, the polypropylene bio-based antibacterial composite film includes an upper surface layer 1, a core layer 2, and a lower surface layer 3 arranged in sequence. Among them, the upper surface layer 1, the core layer 2, and the lower surface layer 3 are all based on copolymerized polypropylene resin.

[0030] Specifically, the upper surface layer 1 includes components with the following raw material percentages: 97-99.5% of copolymerized polypropylene resin and 0.5-5% of anti-blocking agent. Here, adding the anti-blocking agent helps prevent adhesion to, for example, packaged items; the core layer 2 includes components with the following raw material percentages: 99-99.5% of homopolymerized polypropylene resin and 0.5-1% of antistatic agent; the lower surface layer 3 includes components with the following raw material percentages: 85-98.4% of copolymerized polypropylene resin, 0.5-5% of anti-blocking agent, 0.1-10% of modified compatibilizer, and 1-10% of antibacterial masterbatch.

[0031] The above-mentioned copolymerized polypropylene resin is at least one of binary copolymerized polypropylene and ternary copolymerized polypropylene; among them, the density of polypropylene is 0.90-0.98 g / cm3, and the melt index is 2-10 g / 10 min under the test conditions of a temperature of 230 °C and a load of 2.16 kg.

[0032] Furthermore, a modified compatibilizer and an antibacterial masterbatch are added to the lower surface layer 3 here. The antibacterial masterbatch has a bactericidal effect and has bio-based compounds; in order to achieve the combination of the antibacterial masterbatch and polypropylene, a trace amount of modified compatibilizer is added to the antibacterial masterbatch, which can endow the polypropylene film with antibacterial effect. That is, the purpose of using the modified compatibilizer here is to improve the compatibility between the bio-based compounds and the surface film.

[0033] Specifically, the main antibacterial component of the antibacterial masterbatch is a bio-based extract, which includes 10-20% of bio-based antibacterial agent, 0.05-1% of compatibilizer, and 80-90% of matrix resin. Among them, the bio-based antibacterial agent includes at least one of flavonoids and their derivatives, phenolic acid extracts, tannin compounds, and monoterpene extracts; the modified compatibilizer includes a compatibilizer and a matrix resin. The above-mentioned compatibilizer is at least one of maleic anhydride grafted polyolefin, polyolefin elastomer, peroxide compatibilizer, acrylic acid grafted to polyolefin resin, and glycidyl methacrylate. In addition, it can also be a low-molecular-weight compatibilizer, etc.; the above-mentioned matrix resin is polypropylene or polyethylene.

[0034] In a specific embodiment, the upper surface layer 1 comprises components with the following raw material percentages: 97% of a copolymerized polypropylene resin and 3% of an anti-blocking agent; the core layer 2 comprises components with the following raw material percentages: 99% of a homopolymerized polypropylene resin and 1% of an antistatic agent; the lower surface layer 3 comprises components with the following raw material percentages: 90% of a copolymerized polypropylene resin, 3% of an anti-blocking agent, 2% of a modified compatibilizer, and 5% of an antibacterial masterbatch. Among them, the antibacterial masterbatch comprises 10% of a bio-based antibacterial agent, 1% of a compatibilizer, and 89% of a matrix resin. In order to achieve the combination of the bacteriostatic agent and polypropylene, a trace amount of compatibilizer is added to the antibacterial material to endow the polypropylene film with a bacteriostatic effect.

[0035] On the basis of ensuring performance parameters, the embodiments of the present disclosure also have good antibacterial and bactericidal functions.

[0036] The second embodiment of the present disclosure provides an application of a polypropylene bio-based antibacterial composite film in inhibiting bacteria. The polypropylene bio-based antibacterial composite film is the polypropylene bio-based antibacterial composite film in any one of the above embodiments. The bacteria here can be at least Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), and of course, other bacteria can also be included.

[0037] On the basis of ensuring performance parameters, the embodiments of the present disclosure also have good antibacterial and bactericidal functions.

[0038] The third embodiment of the present invention provides a preparation process of a polypropylene bio-based antibacterial composite film. The polypropylene bio-based antibacterial composite film here is the polypropylene bio-based antibacterial composite film in any one of the above. The preparation process includes the following steps:

[0039] Step 1. The raw materials of the components in each layer above are uniformly mixed and then melt co-extruded and cooled to form a thick sheet. Among them, the lower surface layer 3 is extruded through a first auxiliary extruder, and its outlet temperature is 245 - 250°C; the core layer 2 is extruded through a main extruder, and its outlet temperature is 245 - 250°C; the upper surface layer 1 is extruded through a second auxiliary extruder, and its outlet temperature is 245 - 250°C and the die head temperature is 245 - 250°C; in addition, the temperature of the cooling casting device is controlled at 75 - 80°C;

[0040] Step 2. The thick sheet formed in Step 1 is successively passed through a longitudinal stretching device (Machine Direction Orientation, MDO) and a transverse stretching device (Transverse Direction Orientation, TDO) to perform a biaxial stretching process to generate a film:

[0041] Among them, the temperature control of the rollers in the longitudinal stretching device is as follows: preheating zone 85 - 90 °C, stretching zone 110 - 115 °C, shaping zone 90 - 95 °C, stretching ratio 4.5 - 5.5;

[0042] Among them, the temperature control of the rollers in the transverse stretching device is as follows: preheating zone 150 - 155 °C, stretching zone 125 - 130 °C, shaping zone 95 - 100 °C, stretching ratio 6 - 8;

[0043] Step 3. Corona-treat the film stretched in the above Step 2 to increase the surface tension;

[0044] Step 4. Wind the film processed in the above Step 3 into a master roll for aging treatment;

[0045] Step 5; Cut the film processed in the above Step 4 into products according to requirements.

[0046] The effects of the polypropylene bio-based antibacterial composite film prepared by the above preparation process are shown in the following table:

[0047]

[0048] On the basis of ensuring the performance parameters, the embodiments of the present disclosure also have good antibacterial and bactericidal functions.

[0049] In addition, the features of the embodiments shown in the drawings of the present application or various embodiments mentioned in this specification need not be understood as independent embodiments of each other. Instead, each feature described in one example of one embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings.

[0050] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A polypropylene bio-based antibacterial composite film, characterized in that: It adopts a multi-layer composite structure, which includes an upper surface layer, a core layer and a lower surface layer which are arranged in sequence. The upper surface layer includes components with the following raw material percentages: 97-99.5% of copolymerized polypropylene resin and 0.5-5% of anti-blocking agent, the core layer includes components with the following raw material percentages: 99-99.5% of homopolymerized polypropylene resin and 0.5-1% of antistatic agent; the lower surface layer includes components with the following raw material percentages: 85-98.4% of copolymerized polypropylene resin, 0.5-5% of anti-blocking agent, 0.1-10% of modified compatibilizer and 1-10% of antibacterial masterbatch.

2. The polypropylene bio-based antibacterial composite film according to claim 1, characterized in that: The copolymerized polypropylene resin is at least one of binary copolymerized polypropylene and ternary copolymerized polypropylene; wherein the density of the polypropylene is 0.90-0.98 g / cm3, and the melt index is 2-10 g / 10 min under the test conditions of temperature 230°C and load 2.16 kg.

3. The polypropylene bio-based antibacterial composite film according to claim 1, characterized in that: The antibacterial masterbatch comprises 10-20% of a bio-based antibacterial agent, 0.05-1% of a compatibilizer and 80-90% of a base resin.

4. The polypropylene bio-based antibacterial composite film according to claim 1, characterized in that: The bio-based antibacterial agent includes at least one of flavonoids and their derivatives, phenolic acid extracts, tannin compounds, and safflower extracts.

5. The polypropylene bio-based antibacterial composite film according to claim 1, characterized in that: The modified compatibilizer comprises a compatibilizer and a base resin.

6. The polypropylene bio-based antibacterial composite film according to claim 1, characterized in that: The compatibilizer is at least one of maleic anhydride grafted polyolefin, polyolefin elastomer, peroxide compatibilizer, acrylic acid grafted to polyolefin resin, and glycidyl methacrylate.

7. The polypropylene bio-based antibacterial composite film according to claim 1, characterized in that: The base resin is polypropylene or polyethylene.

8. Application of a polypropylene bio-based antibacterial composite film in inhibiting bacteria, characterized in that: The polypropylene bio-based antibacterial composite film is the polypropylene bio-based antibacterial composite film according to any one of claims 1 to 7, and the bacteria can be at least Gram-positive bacteria and Gram-negative bacteria.

9. A process for preparing a polypropylene bio-based antibacterial composite film, characterized in that: The polypropylene bio-based antibacterial composite film is the polypropylene bio-based antibacterial composite film according to any one of claims 1 to 7, and the preparation process comprises the following steps: Step 1, uniformly mixing the raw materials of each component in each layer, performing melt co-extrusion and cooling to form a thick sheet; Step 2, the thick sheet formed in step 1 is sequentially subjected to a biaxial stretching process by a longitudinal stretching device and a transverse stretching device to form a film; Step 3, performing corona treatment on the film stretched in step 2 to increase the surface tension; Step 4, winding the film treated in step 3 into a mother roll for aging treatment; Step 5, the film processed in step 4 is cut into products according to demand.

10. The process for preparing the polypropylene bio-based antibacterial composite film according to claim 9, characterized in that: The raw materials of the components in the above-mentioned layers are uniformly mixed, melt co-extruded and cooled to form a thick sheet, the lower surface layer is extruded by a first auxiliary extruder, and its outlet temperature is 245-250°C; the core layer is extruded by a main extruder, and its outlet temperature is 245-250°C; the upper surface layer is extruded by a second auxiliary extruder, and its outlet temperature is 245-250°C and the die head temperature is 245-250°C; in addition, the temperature of the cooling casting device is controlled at 75-80°C; In the process of biaxially stretching the thick sheet formed in step 1 through a longitudinal stretching device and a transverse stretching device in sequence to generate a film, the temperature of the rollers in the longitudinal stretching device is controlled as follows: 85-90°C in the preheating zone, 110-115°C in the stretching zone, 90-95°C in the shaping zone, and a stretching ratio of 4.5-5.5; the temperature of the rollers in the transverse stretching device is controlled as follows: 150-155°C in the preheating zone, 125-130°C in the stretching zone, 95-100°C in the shaping zone, and a stretching ratio of 6-8.

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