JP6840459B2 - The process of preparing biodegradable or biocomposable or biodigestible plastics - Google Patents

Description

The present invention relates to biodegradable, biocomposable, biodigestible plastics and methods for preparing them, and particularly to the process of preparing biodegradable or biocomposable or biodigestible plastics.

Plastics such as polyethylene and polypropylene are made from petroleum.
Decomposition of these plastics takes many years in the natural environment and pollutes water, soil and air.

Synthetic polymers undergo different rates and different degrees of environmental degradation depending on their polymer properties and the environment in which they are present.
This type of decomposition occurs by the catalytic reaction of mechanical forces such as light, heat, air, water, microorganisms, wind, rain, and traffic.
Polymers are usually changed from hydrophobic to hydrophilic materials by additives, modifications of the polymer backbone, introduction of functional groups, or mixing of suitable fillers, and their stability and / or Decomposition is enhanced.
However, many of these decomposition techniques give rise to harmful attributes in polymer products.

Petroleum-based synthetic polymers or plastics have excellent physical properties, light weight, and high cost performance, so they can overcome the problems and limitations of using natural materials.
Plastic materials are one of the hallmarks of modern science, and the development of various hydrophilic polymers, especially hydrophilic plastics, has already been demonstrated.
However, as the pollution problems caused by large quantities of plastic products around the world become more serious, various countermeasures have been enacted in various countries around the world.
Moreover, resolving the pollution caused by plastic waste has become a challenging agenda.

Recycling, incineration and landfill have been the primary solutions to the environmental pollution problems caused by various solid wastes, including plastics.
However, the essential problem is that the problem of environmental pollution cannot be completely solved even by landfilling and recycling of waste.

Therefore, recently, the development of biodegradable and / or biocomposable plastics that spontaneously decompose at the end of the life cycle has promoted great interest and research.
The above techniques apply the area of degradable plastics to photodegradation, oxidative degradation, oxidative biodegradation, biodegradability, bio-photomultidegradation, and more recently on an industrial manufacturing scale with light and / or oxygen groups and / Alternatively, it was classified into a combination of biodegradable plastic compounding technology.

Currently, various biodegradable plastics are already being developed.
For example, microbially formed polymers include PHBs (polyβ-hydroxybutyrate), which are biochemical polymers made using microorganisms or natural polymers, including polymers of chitin or starch.
In the present specification, starch is taken up in order to improve the problem of various polymer additives related to the technique of the present invention.

G. J. L. Griffin's Patent Document 1 discloses a preparation method for improving a biodegradable thin film.
In the above method, the surface of starch is treated with a silane coupling agent, thereby forming hydrophobicity on the surface.
However, it can only increase the strength of a small amount of physical interaction between the matrix resin and starch, and cannot solve the problem of deterioration of its physical performance when the thin film binds to starch.

United States Department of Agriculture (USDA) F. H. Patent Document 2 and Patent Document 3 applied for by Oty et al. Disclose a method for preparing a biodegradable thin film by adding α-starch to an ethylene-acrylic acid copolymer.
However, the physical performance of the thin film produced by the ethylene-acrylic acid copolymer is low and the price is high, and it is difficult to spread it in large quantities.

Patent Document 4 and Patent Document 5 applied for by Seonil Glucose of Korea increase the hydrophobicity of starch or the hydrophilicity of matrix resin to increase the strength of physical interaction between matrix resin and starch. Disclose how to fortify and increase compatibility between matrix resin and starch.

Patent Document 6 discloses photodegradable and biodegradable polyethylene.
It produces a ternary copolymer with better photodegradability than copolymers by co-treated ethylene and 2-methylene-1,3-dioxepane (MDOP).
This is because the carbonyl added to the polymer ruptures when it absorbs light (sunlight or ultraviolet light).
The ternary copolymer is photodegradable and biodegradable at the same time because the ester and carbonyl are functionalized together.

Patent Document 7 discloses a biodegradable polyethylene composition that forms a chemical bond with starch and a method for preparing the biodegradable polyethylene composition.

Therefore, it is necessary to provide a peptide-polyethylene having high production efficiency.
In the present invention, it is called PEPrene.
It has good biodegradability or biocomposable or biodigestibility in the environment.

U.S. Pat. No. 4,02138 U.S. Pat. No. 4,133,784 U.S. Pat. No. 4,337,181 Korean Patent No. 90-6336 Korean Patent No. 91-8553 U.S. Pat. No. 5,281,681A U.S. Pat. No. 5,461,094A

The process of preparing a biodegradable or biocomposable or biodigestable plastic according to the present invention provides a biodegradable or biocomposable or biodigestible plastic or polymer product.

Super bags, agricultural cover films, packaging films, etc. are all in polymer processing and are biodegradable, biocomposable or biodigestible by mixing biodegradable, biocomposable or biodigestible additives. It has the characteristics of.
This replaces ordinary petroleum-based plastics.
Therefore, a plastic formulation is developed by mixing edible levels of natural peptides or enzymes or proteins.
As a result, polyethylene, polypropylene and other grade products of petroleum polymers that have been difficult to biodegrade, that is, polyolefins, become biodegradable, biocomposable or biodigestible polyolefin polymers.

The present invention uses peptides or enzymes or proteins, other additives, and polyethylene chains to prepare biodegradable, biocomposable, or biodigestible thin films by chemical bonding.
Polyolefins are commonly applied and widely used polymers as a preparation method.
The processing technique can also be applied to other polyolefins such as polypropylene.

It is an environmental biodegradable state of the PEPrene thin film. The PEPrene thin film is in a biodegradable state after 150 days of environmental soil. Peptides or enzymes or proteins mixed in the PEPrene masterbatch indicated by the FTIR test. It is a peptide, enzyme or protein mixed in a PEPrene thin film shown by FTIR test. The biodegradation percentage of PEPrene.

(One Embodiment)
The present invention discloses biodegradable, biocomposable, biodigestible plastics and methods for preparing them.
The compositions provided by the present invention and methods of their preparation accelerate the biodegradability, biocomposability or biodigestibility of PEPrene materials.

The method of preparing the composition comprises at least one peptide bond, at least one protein and enzyme, and a fermenting agent.
Next, in the presence of preferred additives, at temperature conditions of 45-300 ° C., at least one polymer is mixed to retain the required catalytic reaction performance and the essence of the peptide or enzyme or protein.
The composition produced by this method can be used directly or is contained in a polymer to form a coating composition or coating liquid.

The compositions of the above various embodiments are described below.
Enzymes-Cellulase, papaya enzyme. However, it is not limited to the embodiment described in the text.
Protein or peptide -milk, vegetables (soybeans, okra), but not limited to the embodiments described in the text.
Fermentant- Carboxymethyl cellulose, hydrolyzed mutton fat. However, it is not limited to the embodiment described in the text.
Polymer-Polyethylene is at least one type of linear low density polyethylene (LLDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene, ethylene vinyl acetate (EVA) and butyl ethylene acrylate (EBA). And any combination thereof.
Additives-Citric acid, lactobacillus, hydrolyzed mutton fat, yeast and any combination thereof to improve the biodegradability, biocomposability or biodigestibility of polymeric materials.

The composition of the present invention is a food-grade material having a natural component, and may contain other charcoal-water compounds such as lactose and starch.
The present invention simplifies the process of preparing the composition and reduces production costs.
It enhances the strength of the physical interaction between the matrix resin and the peptide or enzyme or protein and the above-mentioned additives, thus solving the problem of thin film property degradation.
In addition, another specific embodiment, a biodegradable, biocomposable or biodigestible polyethylene composition and starch are interconnected by chemical bonding.

As shown in FIG. 1, the PEPrene composition has a molecular weight of at least about 7000 and has good biodegradability, biocomposability or biodigestibility.

As shown in FIGS. 3 and 4, in plastic polymers, peptides or enzymes or protein groups (carboxyls, etc.) are random along the polyethylene polymer backbone based on functional groups with different concentrations of x, y, z in spatial integers. Or uniformly distributed in the polymer.
The compression temperature of the blend of plastic compositions is 100-350 ° C.
Thus, during the compression process, the composition infiltrates or injects the cell or molecular structure of the polymer when the polymer is in a pre-melted state.

The plastic products obtained by the process of the present invention include secondary packaging or plastic films, vest bags, trash can liners, trash bags, agricultural cover films and many other types of thin films.
Currently blends of compositions are applied to polymers.
For example, 3D printing, fiber spinning, injection molded non-woven materials, and melt spinning processing techniques are included, but these are just examples.

The biodegradable mechanism involves several steps:
Treatment: Peptides or enzymes or proteins are introduced to make the polymer chain hydrophilic. In the process of compressing the peptide or enzyme or protein to penetrate the polymer, the polymer is in a pre-melted state, thus the polymer formulation is hydrophilic.
Pyrolysis: Hydrophilic polymers are further processed into polymer membranes. Pyrolysis then occurs or is broken down into smaller fragments, based on laboratory temperature conditions, environmental humidity and the reaction of light with oxygen.
Soil treatment: After thermal decomposition (whether in laboratory conditions or in the natural environment), the peptides, enzymes or proteins present in the compositions of the present invention are hydrophilic and therefore easily aspirate soil microorganisms and polymer. Is attacked. Due to the hydrophilicity of the composition and / or the water content in the soil (eg, 58% water content), the polymer formulation contains a unique water content that separates or weakens the polymer chain into a molecular state. In this way, through the process of natural composting, the depolymerized products in it provide nutrients for microorganisms in the soil, and the surplus products become raw substances.
Degradation: Polymers are metabolized by microorganisms to become the final metabolites of biodegradation, carbon dioxide and water.

In one specific embodiment, the enzyme composition of the present invention mixes a kind of powdery copolymer, namely linear low density polyethylene (LLDPE).
Polyethylene is used in the production of thin films for secondary packaging such as vest bags, trash can liners, trash bags, agricultural cover films and the like.
A linear low density polyethylene (LLDPE) copolymer needs to be mixed to increase the elasticity and expandability of the thin film.
Peptides or enzymes or proteins present in polyethylene and other additives aspirate microorganisms in the soil, producing the action of compost material.
Residuals are biomass, water and carbon dioxide.
The PEPrene polymer biodegradable residue of the present invention is carbon dioxide and water.

Other biodegradable or biorefined products are gases (methane, etc.), ketones (acetone, etc.), alcohols (methanol, ethanol, propanol, butanol, etc.).
Products such as methane and ethanol are known energy sources, and these or other products expected to be obtained may be available and can be further used as energy sources and the like.

The advantages of the present invention are that the polymer products produced by the present invention retain the required mechanical performance and shelf life, and the polymers can be recycled in the same manner as non-biodegradable polymers such as polyethylene.
Unlike spontaneous polymer degradation by photooxidation or oxidative degradation agents, it does not reduce the shelf life of polymer products and is exposed to the microbial environment during biodegradable or biodegradable or biodigestible processes by enzymatic degradation. All you have to do is do it, and then it will end according to the life cycle.

In the present invention, a peptide, enzyme or protein composition is used to prepare a PEPrene thin film by a method of directly dispersing or including.
Furthermore, based on ASTM D5988, ISO14855, ISO17556 and EN13432 or ASTM D6400 (equivalent standard to other countries) test standards, we succeeded in testing the biodegradability and ecotoxicity of these thin films, including the ability to germinate plants in soil. did.
For example, the EN rule stipulates that cellulosic products achieve 90% or more degradation within 180 days.

As shown in FIGS. 1 and 2, the product of the present invention begins to decompose from 90 days based on the composting test conditions.
Degradation rates are usually affected by environmental microbial conditions, the amount of peptide or enzyme or protein composition and product thickness.
For example, the extrusion film thickness of the decomposable products prepared by the present invention reaches 5-50 microns.
Thus, another advantage of the present invention is that the composition is naturally food grade raw material, contains regulations for national plastic materials or products, does not contain toxic substances after decomposition, and / or heavy metal content is within the regulation range. Inside.

The products of the present invention are also recyclable under the ASTM D7209 and EN15347 norms.
The products of the present invention can also be composted according to the EN13432 standard.
Based on ASTM D5988, ISO14855, ISO17556 standards and EN13432 or ASTM D6400 (equivalent to other countries) test norms, this product is a biodegradable plastic (see Figure 5).
The present invention also conforms to food contact safety provisions based on the tests of the US FDA 177.1520.

Another advantage of the present invention is that the materials prepared according to the present invention are easily biodegradable under suitable environmental conditions.
The PEPrene thin films of the present invention are all very stable prior to treatment under soil embedding, composting, landfilling, using biodegradation equipment or similar equipment, and under anaerobic conditions.
The materials are the microbial community formed by the colonies present in the composition of the present invention and the effective microorganisms in the soil, which are metabolically occurring substances.
The thin film of the polyolefin such as polyethylene in the composition of the present invention is attacked by oxidizing microorganisms under aerobic conditions, and is completely biodegraded and biocomposted.
The present invention is easily modified, adjusted, and modified by technical personnel who are proficient in this area.

The embodiments of the present invention described above do not limit the present invention, and therefore, the scope protected by the present invention is based on the claims described later.

Claims (5)

The process of preparing a biodegradable or biocomposable or biodigestible plastic, comprising the following steps:
At least one of the cellulase or papaya enzymes is mixed with at least one peptide or protein derived from milk, soybeans, or okra.
Add a fermenting agent of carboxymethyl cellulose and
Linear low density polyethylene (LLDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), medium in the presence of citric acid, lactobacillus, hydrolyzed mutton fat, yeast and any combination thereof. At least one polyolefin polymer consisting of high density polyethylene (MDPE), vinyl ethylene acetate (EVA) and butyl ethyleneacrylate (EBA) and any combination thereof can be mixed at a temperature of 45-300 ° C to produce a plastic. The process of preparing a characteristic biodegradable or biocomposable or biodigestible plastic. The process for preparing a biodegradable or biocomposable or biodigestible plastic according to claim 1, wherein the plastic preparation by the process is by blow or injection molded product, melt spinning, or 3D printing. According to claim 1 or 2, the plastic product produced by the process includes a secondary packaging or a plastic film, a vest bag, a trash can liner, a trash bag, an agricultural cover film, a polymer fiber, and a non-woven material. The process of preparing the biodegradable or biocomposable or biodigestible plastics described. Linear low density polyethylene (LLDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), vinyl ethylene acetate (EVA) and butyl ethyleneacrylate (EBA) and any combination thereof. Polyolefin polymer consisting of
At least one enzyme of cellulase or papaya enzyme, and at least one peptide or protein derived from any of milk, soybean, and okra.
Carboxymethyl cellulose fermentant and
A biodegradable or biocomposable or biodigestible plastic consisting of citric acid, lactobacillus, hydrolyzed mutton fat, yeast and any combination of additives thereof. The biodegradable or biocompos according to claim 4, wherein the plastic product comprises a secondary packaging or plastic film, a vest bag, a trash can liner, a trash bag, an agricultural cover film, a polymer fiber, and a non-woven material. Table or biodigestible plastic.

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