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CN-121973524-A - Fully biodegradable layered composite material and product thereof

CN121973524ACN 121973524 ACN121973524 ACN 121973524ACN-121973524-A

Abstract

The invention discloses a fully biodegradable layered composite material and a product thereof. The layered composite material has at least three layers, including an outer layer, a barrier layer and an inner layer from the outside to the inside. The composition of the outer layer and the inner layer each comprise a polyolefin and a bioconversion additive comprising a non-enzymatic catalyst. The barrier layer is selected from high barrier polymer layers and may contain additives or biodegradable polyesters to participate in the degradation. The concentration of the bioconversion additive in the outer layer is higher than that of the inner layer, and the protection and the collaborative design of the barrier layer are combined, so that the layered composite material has stable performance in the service period of the product, can be orderly bioconverted and degraded from the outer layer after being abandoned and exposed to natural environment, is finally completely converted into an environment-friendly substance, and does not generate microplastic. The layered composite material is perfectly compatible with the existing processing and recycling system, is suitable for products such as hoses, packaging films and the like, and solves the contradiction between high-performance packaging and complete environmental degradation.

Inventors

  • ZHANG JINGJING
  • LIU LEI

Assignees

  • 三樱包装（江苏）有限公司

Dates

Publication Date
20260505
Application Date
20260212

Claims (11)

  1. 1. A fully biodegradable layered composite material, characterized by a layered composite structure having at least three layers, said at least three layers comprising from the outside to the inside: An outer layer, the composition of which comprises a polyolefin and a bioconversion additive; A barrier layer; An inner layer, the composition of which comprises a polyolefin and the bioconversion additive; the bioconversion additive comprises a non-enzymatic catalyst; The layered composite maintains stable properties under normal storage conditions and is capable of undergoing bioconversion degradation from the outer layer upon exposure to the natural environment.
  2. 2. The layered composite of claim 1, wherein the concentration of the bioconversion additive in the outer layer is higher than the concentration of the bioconversion additive in the inner layer.
  3. 3. The layered composite of claim 2, wherein the bioconversion additive is present in the outer layer in an amount of 2wt% to 5wt% and the bioconversion additive is present in the inner layer in an amount of 1wt% to 3wt%, based on the total mass of the corresponding monolayer composition.
  4. 4. The layered composite of claim 1, wherein the composition of the outer layer further comprises a photosensitizer, and wherein the photosensitizer is present in an amount of 1wt% to 2wt%, based on the total mass of the outer layer composition.
  5. 5. The layered composite of claim 1, wherein the barrier layer is selected from any one of the following structures: A blend layer or co-extruded film layer comprising at least one of an ethylene-vinyl alcohol copolymer, polyamide or polyester, and wherein the bioconversion additive is included; A polyolefin film layer comprising an ethylene-vinyl alcohol copolymer, or a polyolefin coated film layer surface coated with a polyvinylidene chloride barrier coating, and wherein the bioconversion additive is included; a blend layer comprising an ethylene vinyl alcohol copolymer and a biodegradable polyester.
  6. 6. The layered composite of claim 5, wherein when the barrier layer is a blend layer comprising an ethylene-vinyl alcohol copolymer and a biodegradable polyester, the biodegradable polyester is selected from at least one of poly (adipic acid)/poly (butylene terephthalate), poly (lactic acid), poly (hydroxy fatty acid ester).
  7. 7. The layered composite of claim 1, wherein a degradation channel layer is further disposed between the outer layer and the barrier layer, the composition of the degradation channel layer comprising a polyolefin, a water-soluble polymer, and the bioconversion additive.
  8. 8. The layered composite of claim 7, wherein the water-soluble polymer is polyvinyl alcohol or polyethylene oxide.
  9. 9. The layered composite of claim 7, comprising, based on the total mass of the degradation channel layer composition: 30 Polyolefin accounting for 70-wt percent by weight; 30 water-soluble polymer accounting for 70 percent to wt percent of the weight, and 1-4Wt% of the bioconversion additive.
  10. 10. The layered composite as defined in claim 1, wherein an adhesive layer is further provided between said outer layer and said barrier layer and/or between said barrier layer and said inner layer, said adhesive layer comprising a biodegradable resin and/or said bioconversion additive.
  11. 11. An article characterized in that the body structure of the article is made of the layered composite material of any one of claims 1-10.

Description

Fully biodegradable layered composite material and product thereof Technical Field The invention relates to the technical field of packaging materials, in particular to a completely biodegradable composite sheet and a hose. Background In the current society, with the increasing awareness of environmental protection, the problem of white pollution caused by traditional plastic packaging is widely focused. Taking a packaging hose pipe as an example, the packaging hose pipe is widely applied to the fields of daily chemicals, foods, medicines and the like, and a multi-layer composite structure (such as polyethylene/ethylene-vinyl alcohol copolymer/polyethylene, namely PE/EVOH/PE structure) is generally adopted to meet the severe requirements of contents on barrier property, flexibility, printability, sealing property and the like. However, such hoses are often made of non-degradable polyolefins (e.g., polyethylene PE, polypropylene PP), which are difficult to recycle after use, most of which end up in landfills or are discarded to the natural environment, creating persistent pollution. Currently, sustainable solutions for packaging hoses are mainly developed around material systems, and existing maturation paths all have significant limitations: The first class is biobased plastics. The core of this class of materials is that ‌ extracts monomer ‌ from renewable biomass resources (e.g., sugarcane, corn), replacing petroleum-based raw materials to reduce the carbon footprint, but "biobased" is not equivalent to "biodegradable". Typically representing, for example, bio-based polyethylene (Bio-PE), which has a chemical structure identical to that of petroleum-based polyethylene PE and is therefore compatible with existing processing and recovery systems, but is as difficult to degrade in natural environments as conventional PE, and does not solve the problem of environmental pollution after disposal. The second type is a paper-plastic composite hose. It is made by replacing part of the plastic with paper and compounding with an adhesive. Although the proposal can reduce the plastic consumption and improve the texture, the complex composite material structure makes the recovery and separation difficult, and the existence of the paper layer can affect the whole barrier property and durability. The third type is a single material recyclable hose. The single polymer structure such as full PP or full PE is adopted, so that the difficult recovery problem caused by incompatibility of resins in the traditional multilayer material is avoided, and the traditional recovery flow can be smoothly entered. However, this approach is often difficult to meet long-term storage requirements for oxygen, water vapor sensitive high-end contents at the expense of high barrier properties, and has a limited range of applications. In addition, the search for biodegradable plastics (e.g., polylactic acid PLA, poly (butylene adipate/terephthalate) PBAT) is also facing bottlenecks in the hose field. Firstly, the material performance has the disadvantages of large brittleness and poor moisture resistance of PLA, low PBAT strength and insufficient barrier property, and is difficult to meet the comprehensive requirements of a hose on mechanics and barrier, secondly, the degradation of the material usually depends on specific hydrolytic enzymes secreted by microorganisms, the material can be completely degraded only in industrial composting facilities with specific temperature, humidity and microbial communities, the degradation is slow and incomplete in open land or marine environments, and finally, the chemical structure of the material is different from that of the traditional polyolefin, and if the material is mixed into a main stream recovery stream, the quality of regenerated polyolefin is polluted. It should be noted that the foregoing description of the background art is only for the purpose of providing a clear and complete description of the technical solution of the present application and is presented for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background of the application section. Disclosure of Invention The invention aims to provide a completely biodegradable composite sheet and a hose, which are used for solving the problem that the prior art scheme has irreconcilable contradiction among material performance, degradation conditions and system compatibility. To achieve the above object, the present invention provides a completely biodegradable layered composite material having a layered composite structure of at least three layers including, from the outside to the inside: An outer layer, the composition of which comprises a polyolefin and a bioconversion additive; A barrier layer; An inner layer, the composition of which comprises a polyolefin and the bioconversion additive; the