High-temperature-resistant environment-friendly plastic bag

Abstract

The invention relates to the technical field of plastic bags, in particular to a high-temperature-resistant environment-friendly plastic bag which is mainly made of bio-based plastic, the bio-based plastic and polypropylene are mixed to obtain a mixed material, and the mixed material has good heat resistance and can be degraded, so that the plastic bag is more environment-friendly in use, and the service life of the plastic bag is prolonged. Additives with multiple functions are further added into the mixed material and used for improving the performance of the mixed material, the additives comprise a heat stabilizer, a flexibilizer, a compatilizer, a light stabilizer and the like, and the environment-friendly plastic bag has the high temperature resistance in daily use, is not prone to hot melting, is produced from degradable environment-friendly materials and is environmentally friendly. Toxic and harmful substances are not generated, and the use is safer and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of plastic bags, in particular to a high-temperature resistant and environmentally friendly plastic bag. Background Art

[0002] Many of the plastic bags currently on the market are non-degradable or incompletely degradable, posing a huge threat to the natural environment. At present, the annual plastic production in the world is 100 million tons. If we calculate based on the annual plastic waste of 15%, the annual plastic waste in the world is 15 million tons. The annual plastic waste in China is more than 1 million tons, and the proportion of waste plastic in garbage accounts for 40%. A large amount of waste plastic is buried underground as garbage, which undoubtedly brings great harm to the environment; common plastic bags generally cannot be placed in a high temperature environment, and are easy to melt and deform, affecting their use.

[0003] Therefore, it is necessary to design a plastic bag that can be completely degraded and has no pollution to the environment. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a high temperature resistant and environmentally friendly plastic bag, which can not only achieve complete degradation but also improve the high temperature resistance.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A high-temperature resistant environmentally friendly plastic bag, the raw materials of which include: bio-based plastics, polypropylene and functional additives, the proportion of the bio-based plastics is 20%-30%, the proportion of the polypropylene is 50%-60%, the functional additives include toughening agents, compatibilizers, and heat stabilizers, the proportion of the toughening agents is 5%, the proportion of the compatibilizers is 3%-5%, the proportion of the heat stabilizers is 1%-2%, the raw materials also include reinforcing materials, the reinforcing materials include nano calcium carbonate, the proportion of the nano calcium carbonate is 5%-10%.

[0006] Optionally, in one embodiment of the present invention, the functional additive further includes an antibacterial agent, and the antibacterial agent is any one of nanosilver or chitosan.

[0007] Optionally, in one embodiment of the present invention, the compatibilizer is maleic anhydride grafted polypropylene.

[0008] Optionally, in one embodiment of the present invention, the toughening agent is any one of a polylactic acid-based toughening agent or a bio-based elastomer.

[0009] Optionally, in one embodiment of the present invention, a coupling agent is added to the nano-calcium carbonate for activation treatment before use.

[0010] Optionally, in one embodiment of the present invention, the thermal stabilizer is a calcium / zinc composite stabilizer.

[0011] Optionally, in one embodiment of the present invention, the functional additive further includes an antioxidant, and the antioxidant is any one of tea polyphenols, vitamin E or ascorbic acid and its derivatives, or a mixture of two thereof.

[0012] Beneficial effects of the present invention The high temperature resistant and environmentally friendly plastic bag of the present invention mainly adopts bio-based plastic mixed with polypropylene as raw materials. The generated mixed material has environmental protection and high temperature resistance characteristics. A variety of functional additives are added to the mixed material to further improve other properties of the plastic bag, such as toughness and impact resistance, high temperature resistance, high temperature stability, antioxidant performance, antibacterial performance, etc. The additives used are all food-grade and more environmentally friendly additives. The plastic bag can be degraded, has little impact on the environment, and can meet the needs of daily life. DETAILED DESCRIPTION

[0013] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited to the specific embodiments disclosed below.

[0014] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the preferred embodiments. Example

[0015] In order to make the use of plastic bags more environmentally friendly and resistant to high temperatures, a high-temperature resistant and environmentally friendly plastic bag has been developed. The specific plan is as follows: A high-temperature resistant environmentally friendly plastic bag, the raw materials of which include: bio-based plastics, polypropylene and functional additives, the proportion of bio-based plastics is 20%-30%, the proportion of polypropylene is 50%-60%, the functional additives include toughening agents, compatibilizers, and heat stabilizers, the proportion of toughening agents is 5%, the proportion of compatibilizers is 3%-5%, and the proportion of heat stabilizers is 1%-2%, and the raw materials also include reinforcing materials, the reinforcing materials include nano-calcium carbonate, and the proportion of nano-calcium carbonate is 5%-10%.

[0016] As an inorganic nanofiller, nano calcium carbonate can improve the mechanical properties and thermal stability of composite materials.

[0017] In this embodiment, the proportion of bio-based plastic is 20%, the proportion of polypropylene is 60%, the proportion of toughening agent is 5%, the proportion of compatibilizer is 3%, the proportion of heat stabilizer is 1%, and the proportion of nano-calcium carbonate is 9%. The resulting composite material has a 20.5% increase in tensile strength, a 15% increase in flexural strength, and a 20% increase in notched impact strength.

[0018] Increasing the amount of nano-calcium carbonate added within a suitable range can also significantly improve the thermal stability of the composite material and increase the initial degradation temperature.

[0019] The functional additives also include antibacterial agents, and the antibacterial agent is any one of nanosilver or chitosan.

[0020] If the plastic bag needs to have antibacterial properties to ensure the freshness of the food inside, an appropriate amount of antibacterial agent can be added to the composite material to make the plastic bag more antibacterial and fresh-keeping for food.

[0021] The compatibilizer is maleic anhydride grafted polypropylene, which has good compatibility with polypropylene, thereby enhancing the overall performance of the bio-based plastic and polypropylene mixed material.

[0022] The toughening agent is any one of a polylactic acid-based toughening agent or a bio-based elastomer.

[0023] Maleic anhydride grafted polylactic acid is also well compatible with polypropylene. Bio-based elastomers can be natural rubber derivatives or bio-based polyurethane elastomers, which can be used to improve the toughness of composite materials.

[0024] Before use, the nano calcium carbonate is activated by adding a coupling agent.

[0025] The activation treatment can be carried out by dissolving the coupling agent in a suitable solvent, then adding the nano-calcium carbonate powder thereto, stirring and reacting at a certain temperature for a period of time, so that the coupling agent and the surface of the nano-calcium carbonate are chemically bonded. After the reaction is completed, the activated and coupled nano-calcium carbonate is obtained by filtering, washing, drying and other steps. In other embodiments, the activation treatment of the surface of the nano-calcium carbonate can also be carried out with an acid solution. The nano-calcium carbonate powder is divided into an appropriate amount of acid solution. The acid solution can be hydrochloric acid or acetic acid. The reaction is stirred at a certain temperature for a period of time to allow the acid rain nano-calcium carbonate to fully act. After the reaction is completed, the activated nano-calcium carbonate is obtained by filtering, washing, drying and other steps.

[0026] The activation treatment grafts a layer of polymer segments with good compatibility with the polymer matrix onto the surface of the nano-calcium carbonate particles through chemical reactions. The interaction between the nano-calcium carbonate and the polymer matrix is ​​enhanced. The dispersibility and compatibility of the nano-calcium carbonate after surface modification are significantly improved, and a uniformly distributed nano-structure can be formed in the polymer matrix. This nano-structure can effectively transmit and disperse stress, thereby improving the mechanical properties and processing properties of the polymer.

[0027] The heat stabilizer is a calcium / zinc composite stabilizer.

[0028] Calcium / zinc composite stabilizers can significantly improve the thermal stability of bio-based plastics and polypropylene mixtures. During high-temperature processing and use, the mixture can maintain stable performance, reduce degradation and discoloration, and improve the processing properties of the mixture, such as increasing fluidity and reducing melt viscosity. This helps to reduce processing difficulty, improve production efficiency and product quality, does not contain toxic heavy metal components, and meets environmental protection requirements.

[0029] The functional additives also include antioxidants, which are any one of tea polyphenols, vitamin E or ascorbic acid and its derivatives, or a mixture of two of them.

[0030] In this embodiment, the antioxidant is tea polyphenols, and the addition ratio of the antioxidant is 1%. Tea polyphenols have excellent antioxidant properties and good biocompatibility. It can not only be used as food packaging materials, but also inhibit the oxidation reaction in food to a certain extent, maintaining the freshness and nutritional value of food.

[0031] In this embodiment, the preparation process of the plastic bag is as follows: Step S1, washing and crushing the bio-based plastic; Step S2, activating the nano calcium carbonate; Step S3, mixing the bio-based plastic, polypropylene, toughening agent, compatibilizer, heat stabilizer and nano calcium carbonate uniformly according to a predetermined ratio; The order of mixing the raw materials is as follows: First, the bio-based plastic is mixed with polypropylene, and then the toughening agent is added to the polypropylene for better dispersion and mixing. Then the compatibilizer is added to ensure the uniform mixing and stabilization of the bio-based plastic and other ingredients such as polypropylene. Then nano calcium carbonate is added, and finally the heat stabilizer and antioxidant are added to prevent the plastic from degrading during high-temperature processing.

[0032] Step S4, feeding the mixed raw materials into a melt extruder, and melt-mixing them under high temperature and high pressure to form a uniform solution; Step S5, extruding the molten plastic through the annular die of the film blowing machine, and introducing compressed air to expand it into a tubular film, and finally processing it into a plastic bag.

[0033] The high temperature resistant and environmentally friendly plastic bag of this scheme uses natural biomass as raw material, has biodegradable characteristics, can be decomposed into carbon dioxide and sulfur by microorganisms in the natural environment, reduces environmental pollution, reduces dependence on petroleum resources, and contributes to sustainable development. In the mixed material, the raw materials contain polypropylene and heat stabilizer, which can improve the high temperature resistance of the plastic bag. The addition of toughening agent can significantly improve the toughness and impact resistance of the plastic bag, and it will not break easily. The addition of compatibilizer improves the stability and efficiency of the processing process. The addition of nano calcium carbonate improves the strength of the plastic bag and makes the molding and processing of the plastic bag easier. All raw materials meet environmental protection requirements, are harmless to the human body and the environment, and can ensure the safety and hygiene of food. Example

[0034] In this embodiment, the composition of the plastic bag is substantially the same as that of the plastic bag in Embodiment 1, except that tea polyphenols are added to the composition to enhance the antioxidant properties of the plastic bag.

[0035] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above in the form of preferred embodiments, it is not intended to limit the present invention. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high temperature resistant environmentally friendly plastic bag, characterized in that: The raw materials include: bio-based plastics, polypropylene and functional additives. The proportion of the bio-based plastics is 20%-30%, the proportion of the polypropylene is 50%-60%, the functional additives include toughening agents, compatibilizers, and heat stabilizers. The proportion of the toughening agent is 5%, the proportion of the compatibilizer is 3%-5%, and the proportion of the heat stabilizer is 1%-2%. The raw materials also include reinforcing materials, and the reinforcing materials include nano-calcium carbonate, and the proportion of the nano-calcium carbonate is 5%-10%.

2. The high temperature resistant environmentally friendly plastic bag according to claim 1, characterized in that: The functional additive also includes an antibacterial agent, and the antibacterial agent is any one of nanosilver or chitosan.

3. The high temperature resistant environmentally friendly plastic bag according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted polypropylene.

4. The high temperature resistant environmentally friendly plastic bag according to claim 1, characterized in that: The toughening agent is any one of a polylactic acid-based toughening agent or a bio-based elastomer.

5. The high temperature resistant environmentally friendly plastic bag according to claim 1, characterized in that: Before use, the nano calcium carbonate is activated by adding a coupling agent.

6. The high temperature resistant environmentally friendly plastic bag according to claim 1, characterized in that: The heat stabilizer is a calcium / zinc composite stabilizer.

7. The high temperature resistant environmentally friendly plastic bag according to claim 1, characterized in that: The functional additives also include antioxidants, which are any one of tea polyphenols, vitamin E or ascorbic acid and derivatives thereof, or a mixture of two of them.