CN216153285U

CN216153285U - Biodegradable high-barrier paper-plastic packaging composite film

Info

Publication number: CN216153285U
Application number: CN202121845224.4U
Authority: CN
Inventors: 顾成; 周伟学; 孙宁; 李斌斌
Original assignee: Jiangsu Leater Green Packaging Corp ltd
Current assignee: Jiangsu Leater Green Packaging Corp ltd
Priority date: 2021-08-09
Filing date: 2021-08-09
Publication date: 2022-04-01
Anticipated expiration: 2031-08-09

Abstract

The utility model provides a biodegradable high-barrier paper-plastic packaging composite film which sequentially comprises an ink layer, a paper layer, a barrier coating, an adhesive layer and a PLA layer from the outside to the inside, wherein the PLA layer can ensure the heat sealing performance of the composite film and meet the packaging requirements of different contents and different weights; the barrier coating can ensure that the final finished product has good barrier property and the shelf life of the contents is prolonged. The biodegradable high-barrier paper-plastic packaging composite film has the advantages of exquisite printing appearance, good display effect and the like, is made of degradable materials, can be biodegraded after being used, and has no pollution to the environment.

Description

Biodegradable high-barrier paper-plastic packaging composite film

Technical Field

The utility model belongs to the field of packaging materials, and particularly relates to a biodegradable high-barrier paper-plastic packaging composite film.

Background

The traditional plastic products become common consumables in life of people due to the characteristics of lightness and low price. However, since the plastic products are difficult to degrade, the plastic products left after being discarded can bring serious harm to the environment, namely the plastic products are commonly called as 'white pollution'. According to the analysis of Kearney, only 8% of plastics are currently recycled in the world, and 800 million tons of plastic waste enter the ocean every year. The total amount of global plastic usage is about 30% from the packaging article, which number amounts to 1.1 million tons in 2019. By 2050, plastic production is expected to increase dramatically, and this number is predicted to reach 7 billion tons. If no countermeasures are taken, this would result in 6.44 million tons of plastic entering the landfill annually. With the increasing proportion of the packaging in the global plastic and the increasing awareness of consumers, consumers demand enterprises to change.

With the increasing severity of the problem of white pollution, the national institute of government has gone out of the "plastic restriction" in 2007 month 12, and the plastic shopping bags with the thickness less than 0.025 mm are required to be prohibited from production and sale and used nationwide. In 1 month 2020, the national institute of improvement and improvement, department of ecological environment, issued "opinions on further enhancement of plastics pollution control" (article 80), which requires prohibition and restriction of production, sale and use of part of plastic products, and "plastic-restricted order" is upgraded from this to "plastic-prohibited order".

No. 80 documents simultaneously require that: the method is directed to recycling, easy recovery and degradability, and develops plastic products and substitute products with standard popularization performance, environmental protection, economy and applicability. At present, the conventional plastic package usually adopts high polymer films such as PE (polyethylene), PET (polyethylene terephthalate), PP (polypropylene), PVC (polyvinyl chloride), PA (nylon) and the like as base materials, and among these high polymer films, PE, PET, PP, PVC and the like all belong to non-biodegradable high polymer materials, and PA is a degradable material, but the degradation period is generally more than 30 years. These high molecular materials are not suitable for the development of the new generation of degradable plastic packaging.

In the research and development of degradable plastics, the current main global trend is starch-based plastics, PLA, PBAT. The PLA (polylactic acid) is pollution-free in the production process, reliable in biosafety, good in mechanical property and easy to process, the degraded products are carbon dioxide and water, the environment cannot be influenced, the PLA is a well-known degradable material with the greatest development prospect, and the PLA can be used for manufacturing food packages, medical packages, agricultural mulching films and the like.

However, PLA has the disadvantages of poor heat resistance, low softening temperature, difficult film formation, brittle and breakable quality, general barrier property and the like. If these problems are solved by the modification method, the cost is greatly increased. This is also the main reason why PLA plastic articles are not currently used on a large scale. Therefore, it is an urgent problem to provide a biodegradable packaging composite film material meeting the use requirements.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, an object of the present invention is to provide a biodegradable high-barrier paper-plastic packaging composite film, which is made of a degradable material, can be biodegraded after use, and has no environmental pollution, and the composite film includes a barrier coating layer and a PLA layer, which can improve the barrier property thereof, and meet the packaging requirements of different contents and different weights.

In order to achieve the purpose, the utility model adopts the technical scheme that:

the utility model provides a biodegradable high-barrier paper-plastic packaging composite film, which comprises an ink layer, a paper layer, a barrier coating, a bonding layer and a PLA layer which are sequentially arranged from the outside to the inside; the bonding layer is solvent-free polyurethane adhesive; the barrier coating is a PVA film.

The biodegradable high-barrier paperThe water vapor transmission rate of the plastic packaging composite film at 38 ℃ is less than 1g/m²(d) oxygen transmission rate at 23 ℃ of less than 0.5cm³/m²/d。

The ink layer is degradable water-based ink.

The paper layer is kraft paper, wood pulp paper or glassine paper.

Compared with the prior art, the utility model has the beneficial effects that:

the biodegradable high-barrier paper-plastic packaging composite film provided by the utility model sequentially comprises an ink layer, a paper layer, a barrier coating, an adhesive layer and a PLA layer from the outside to the inside, wherein the barrier coating can ensure that a final finished product has good barrier property and prolong the quality guarantee period of contents, and the PLA layer can meet the packaging requirements of different contents and different weights. The biodegradable high-barrier paper-plastic packaging composite film has the advantages of exquisite printing appearance, good display effect and the like, is made of degradable materials, can be biodegraded after being used, has no pollution to the environment, accords with the global commitment book of new plastic economy, is expected to be exported to countries and regions where degradable plastic products such as Europe and America are applied in a large scale except for domestic sale, and has good market prospect.

Furthermore, the selection of paper and ink in the utility model ensures that the final product has good printing performance and appearance effect, and can be naturally degraded at normal temperature and normal pressure.

Furthermore, the solvent-free adhesive is selected, so that the compounded material has good compounding fastness, surface smoothness and stiffness.

Drawings

FIG. 1 is a schematic structural diagram of a biodegradable high-barrier paper-plastic packaging composite film according to the present invention;

wherein: 1 is an ink layer, 2 is a paper layer, 3 is a barrier coating, 4 is an adhesive layer, and 5 is a PLA layer.

Detailed Description

The present invention is described in further detail below.

Referring to fig. 1, the biodegradable high-barrier paper-plastic packaging composite film provided by the utility model comprises an ink layer 1, a paper layer 2, a barrier coating layer 3, an adhesive layer 4 and a PLA layer 5 which are sequentially arranged from the outside to the inside.

In order to ensure the biodegradation effect, the selected materials of the utility model are all green and environment-friendly materials, wherein the ink layer 1 is degradable water-based ink, for example, WPH series degradable water-based ink products of Guangdong Jiajing science and technology corporation can be used, and the products obtain a certification certificate of the biodegradable materials, namely European Union OK composite certification. The paper layer 2 can be kraft paper, wood pulp paper or glassine paper. The selection of paper and printing ink ensures that the final product has good printing performance and appearance effect, and can be naturally degraded at normal temperature and normal pressure. The PLA layer 5 is polylactic acid, also called polylactide, which is a polyester polymer obtained by polymerizing lactic acid as a main raw material, and is a novel biodegradable material. The adhesive layer 4 is a commercially available solvent-free polyurethane adhesive, can be a single-component adhesive or a two-component adhesive, can realize the adhesion and connection of media under the solvent-free condition, is a green and environment-friendly potential adhesive which can be used for food packaging and the like, and can ensure that the compounded material has good compounding fastness, surface flatness and stiffness.

In the utility model, the PVA film is selected as the barrier coating 3, the PVA has unique strong cohesiveness, involucra flexibility, smoothness, oil resistance, solvent resistance, protective colloid property, gas barrier property and wear resistance, and is used as a fiber raw material and also used for producing products such as coating, adhesive, paper processing agent, emulsifier, dispersant, film and the like in a large quantity, and the application range of the PVA is in the industries such as textile, food, medicine, construction, wood processing, paper making, printing, packaging, agriculture, steel, polymer chemical industry and the like. The PVA solution has good adhesion and film forming property, and the PVA solution is prepared to be coated on the surface of the paper layer to obtain the barrier coating 3, so that the final finished product can have good barrier property, and the quality guarantee period of the content can be prolonged. In addition, PVA can be decomposed and degraded by specific bacteria in soil, and has the performance of environmental protection.

Based on the characteristic that paper and polylactic acid (PLA) are degradable in natural environment, the PLA layer and the paper layer with the barrier coating are compounded by adopting a solvent-free compounding process, and the problems of insufficient temperature resistance, flexibility, barrier property and the like of a pure PLA film are solved through the barrier coating. Organic solvent and solvent type ink are not used in the preparation process, the whole preparation process applies green printing technology, good prevention and control means are provided before and after production, the generation of organic waste gas can be effectively reduced, the production process is pollution-free, and the environmental protection requirement is met.

The preparation method of the biodegradable high-barrier paper-plastic packaging composite film comprises the following steps:

1) adding PVA powder into deionized water at the temperature of 80-95 ℃, and uniformly mixing to prepare a PVA solution; defoaming, cooling, filtering and extruding the PVA solution to obtain a solution; coating the solution on a paper layer at 40-60 ℃ until the thickness of a wet film is 300-500 microns, drying at 60-100 ℃, and hot-pressing to flatten the paper to obtain a barrier coating; wherein the drying time is 1-5 minutes, and a flattening roller is adopted to carry out hot pressing on the paper.

2) Printing degradable water-based ink on the other side of kraft paper, wood pulp paper or glassine paper by adopting a gravure printing technology;

3) adding PLA particles into a casting machine, heating to enable the PLA particles to reach a molten state, and extruding through a flat sheet-shaped opening die to form a film to obtain a PLA layer, wherein the film forming temperature is 40-60 ℃;

4) bonding the barrier coating layer with the PLA layer through a solvent-free polyurethane adhesive, and curing at 40-60 ℃ for 30-72 hours to obtain the biodegradable high-barrier paper-plastic packaging composite film.

The bonding method comprises the following specific steps: at room temperature, rolling a component A of the solvent-free polyurethane adhesive on the PLA layer, spraying a component B at 35-45 ℃, and pressing the barrier coating on the PLA layer, wherein the pressing temperature is room temperature-60 ℃; or mixing the component A and the component B of the solvent-free polyurethane adhesive at 35-45 ℃, spraying the mixture on a PLA layer, and pressing the separation coating on the PLA layer at room temperature-60 ℃; or, the single-component solvent-free polyurethane adhesive is coated on the PLA layer in a roller coating or spraying manner, and the barrier coating is pressed on the PLA layer, wherein the pressing temperature is room temperature to 60 ℃.

Through performance tests, the biodegradable high-barrier paper-plastic packaging composite film has excellent water vapor and oxygen barrier properties, wherein the water vapor transmission rate is less than 1g/m²(d) oxygen transmission rate at 23 ℃ of less than 0.5cm³/m²And d. Excellent oil/grease/alcohol resistance; the rubber has excellent mechanical property, excellent kinking property and high stiffness; has good application prospect.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A biodegradable high-barrier paper-plastic packaging composite film is characterized in that: comprises an ink layer (1), a paper layer (2), a barrier coating (3), an adhesive layer (4) and a PLA layer (5) which are arranged from the outside to the inside in sequence; the bonding layer (4) is a solvent-free polyurethane adhesive; the barrier coating (3) is a PVA film.

2. The biodegradable high-barrier paper-plastic packaging composite film according to claim 1, characterized in that: the biodegradable high-barrier paper-plastic packaging composite film has a water vapor transmission rate of less than 1g/m at 38 DEG C²(d) oxygen transmission rate at 23 ℃ of less than 0.5cm³/m²/d。

3. The biodegradable high-barrier paper-plastic packaging composite film according to claim 1, characterized in that: the ink layer (1) is degradable water-based ink.

4. The biodegradable high-barrier paper-plastic packaging composite film according to claim 1, characterized in that: the paper layer (2) is kraft paper, wood pulp paper or glassine paper.