CN102277005A - A highly filled fully biodegradable packaging material - Google Patents

Abstract

A high-filling full-biodegradable packaging material is prepared by mixing and extruding the following components in parts by weight: 70-90 parts of filler, 10-30 parts of biodegradable polymer, 0.5-3 parts of coupling agent and 2-5 parts of plasticizer. Drying the filler at 100-200 ℃ until the water content is less than or equal to 0.5%, stirring and mixing the coupling agent and the dried filler in a high-speed mixer according to a certain proportion, adding the biodegradable polymer and the plasticizer according to a certain proportion, uniformly mixing, extruding and granulating the mixture in an extruder to obtain the packaging material, and processing the packaging material into various packaging materials by blow molding, injection molding, die pressing and the like. After being discarded, the packaging plastic can be degraded into carbon dioxide, water and inorganic minerals in natural environment, solves the problem of white pollution, is a green and environment-friendly packaging material, has high inorganic filler content of over 70 percent, and greatly reduces the production cost. Low production cost, simple preparation process and strong economic and practical applicability.

Description

A highly filled fully biodegradable packaging material

technical field

The invention relates to packaging materials, in particular to a fully biodegradable packaging material mainly composed of inorganic powder.

Background technique

With the development of human economy and society, the demand for plastic packaging materials is increasing day by day, with an annual growth rate of 5%. Common types of plastics used as packaging materials include polyethylene, polypropylene, polyvinyl chloride, etc. With the extensive use of plastics, there have been two serious problems: on the one hand, most of the raw materials of the plastic industry come from petroleum. Natural gas resources are gradually reduced or even exhausted, and the plastic industry will face a shortage of raw materials; on the other hand, because plastics are not easy to decompose and recycle, they become "white pollution" that can be seen everywhere, destroying the ecological environment. Therefore, more and more people and countries advocate the development and application of fully biodegradable plastics. Fully biodegradable plastics are degraded by naturally occurring microorganisms (such as red bacteria, molds, and seaweeds) in nature or under specific conditions (such as composting, anaerobic digestion, or aqueous culture fluid), and can be completely degraded into carbon dioxide or/and Methane, water, etc., are materials with low environmental load. In addition, a considerable part of the main raw materials of biodegradable plastics can be obtained from agricultural resources that are regenerated every year, as a supplementary replacement for limited and depleted non-renewable petroleum resources. At present, there are dozens of biodegradable plastics that have been developed, among which the fully biodegradable plastics that have been industrialized mainly include polylactic acid (PLA), polybutylene succinate (PBS), and polyhydroxyalkanoate (PHA). , polyhydroxybutyrate (PHB), polycaprolactone (PCL), etc., have a very wide range of applications in the fields of medical materials, agriculture, forestry and fishery, packaging, hygiene products, etc., and many industrialized products have been put on the market, such as compost Bags, disposable tableware, agricultural mulching film, packaging film, fishing gear, diapers, surgical binding wire, etc. For example, patent CN1450120A discloses a fully biodegradable aliphatic polyester/starch composite material and its preparation method, which mainly consists of p-dioxanone polymer, starch and compatibilizer. Patent CN1491986A invented a completely biodegradable aliphatic polyester composite material and its preparation method. The fully biodegradable aliphatic polyester is filled with cheap inorganic filler calcium carbonate, and different products can be processed by various processing methods such as extrusion, molding, injection molding, and spinning. Wherein the content of calcium carbonate is 25%-50%. If the content of calcium carbonate is further increased to more than 70%, or even 90%, to develop a truly high-filling and fully biodegradable packaging material, there are relatively few reports on this, and related packaging products are rarely sold on the market.

Contents of the invention

The technical problem to be solved by the present invention is to provide an environmentally friendly non-toxic green packaging material to solve the problem that traditional packaging materials cannot be degraded and cause environmental pollution. The inorganic filler of the packaging material can reach 70-90% of the weight. Highly filled, fully biodegradable packaging materials with significantly reduced costs.

The technical solutions adopted are:

A highly filled fully biodegradable packaging material, which is mixed and extruded from the following components, in parts by weight:

Inorganic filler 70-90

Biodegradable polymer 10-30

Coupling agent 0.5-3

Plasticizer 2-5

The fillers mainly refer to inorganic fillers, which are characterized in that the inorganic fillers are cheap inorganic powders, including but not limited to calcium carbonate, magnesium carbonate, calcium sulfate, magnesium sulfate, fly ash, clay, talc Powder, mica powder, kaolin, titanium dioxide, chalk or magnesia powder or a mixture of several, especially inorganic powder with a particle size of less than 800 meshes.

The biodegradable polymer refers to fully biodegradable plastics that can be completely decomposed into water and carbon dioxide by microorganisms in the environment, including but not limited to polybutylene succinate, polylactic acid, polyglycolide, poly One or more mixtures of caprolactone and polyhydroxybutyrate.

The coupling agent is used to improve the compatibility between adding inorganic fillers and fully biodegradable plastics, including but not limited to silicon-based coupling agents, titanium-based coupling agents, aluminum-based coupling agents or aluminum-titanium One or more mixtures in the composite coupling agent.

The plasticizer is an auxiliary agent to improve the toughness and processability of the whole system, and is preferably a mixture of polyols, citric acid esters and waxes. Especially preferred are ethylene glycol, glycerol, sorbitol, tributyl citrate (TBC), trioctyl citrate (TOC), acetyl tributyl citrate (ATBC), acetyl trioctyl citrate (ATOC) , one or more mixtures of methylene laurate maleate, stearic acid, and calcium stearate.

The preparation method of the above-mentioned highly filled fully biodegradable packaging material comprises the following steps:

Step 1: Ensure that the water content of the inorganic filler is ≤0.5%, if it cannot be reached, dry the inorganic filler at a temperature of 60-150°C;

Step 2: Stir the filler and coupling agent in Step 1 in a high-mixer, and heat to activate;

Step 3: Mix the filler activated in Step 2 with the biodegradable polymer and plasticizer;

Step 4: The mixture and granulation of Step 3.

The high-filling and fully biodegradable packaging material of the present invention is prepared by using conventional melt blending methods and equipment. First, the filler is dried at 100-130°C for 2-4 hours to remove moisture; After fully mixing and stirring with the dried calcium carbonate in a high-speed mixer, mix the mixed calcium carbonate, biodegradable polymer and plasticizer in proportion to extrude and granulate in an extruder to obtain high-filling Fully biodegradable packaging materials. According to product requirements, this packaging material can be processed into various packaging materials by blow molding, injection molding, molding and other processing methods.

The beneficial technical effects of the present invention are: after use, the highly filled and fully biodegradable plastic of the present invention can be absorbed into fragments or powder in the natural environment, and further degrade into carbon dioxide, water, and inorganic minerals, solving the problem of "white Pollution" problem, is a truly green and environmentally friendly packaging materials. Moreover, the content of inorganic filler in the material is very high, reaching more than 70%, which greatly reduces the production cost. The production cost is low, the preparation process is simple, and the economical practicability is strong.

Detailed ways

Below in conjunction with embodiment the present invention is described in further detail:

Embodiment one

First select 7 kg of heavy calcium carbonate of 1500 mesh, dry at 100°C for 2 hours; stir and mix in a high-speed mixer, and add 0.2 kg of titanium-based coupling agent of zinc titanate, the temperature is 100°C, and mix for 10 minutes; then Add 3 kg of polybutylene succinate biodegradable polymer and 0.2 kg of ethylene glycol plasticizer and mix evenly, then extrude and granulate in a twin-screw (Φ35) extruder, and set the temperature of the extruder to At 150-200° C., with a rotating speed of 300 rpm, a packaging material is prepared.

According to the ASTM D5338-92 standard test method for aerobic biodegradation of plastics under controlled composting conditions, the results are as follows: a packaging film with a thickness of 0.02mm was prepared by blowing the film as the raw material of this example, and buried in soil at room temperature for 60 Days later began to degrade, 7-9 months completely degraded.

Embodiment two

Select 8 kg of heavy calcium carbonate of 2500 mesh, dry at 100°C for 2 hours; stir and mix in a high-speed mixer, and add 0.3 kg of titanium-based coupling agent of zinc titanate, the temperature is 100°C, and mix for 10 minutes; then add 2 kg of polybutylene succinate biodegradable polymer and 0.2 kg of ethylene glycol plasticizer are mixed evenly and then extruded and granulated in a twin-screw (Φ35) extruder. The temperature of the extruder is set at 150-200° C., with a rotating speed of 300 rpm, to obtain packaging materials.

According to the ASTM D5338-92 standard test method for aerobic biodegradation of plastics under controlled composting conditions, the results are as follows: a packaging film with a thickness of 0.02mm was prepared by blowing the film as the raw material in this example, and buried in soil at room temperature for 45 Days later began to degrade, 5-6 months completely degraded.

Claims (6)

1. A highly filled fully biodegradable packaging material, characterized in that: it is mixed and extruded from the following components, in parts by weight: Filler 70-90 Biodegradable polymer 10-30 Coupling agent 0.5-3 Plasticizer 2-5. 2. The highly filled fully biodegradable packaging material according to claim 1, characterized in that the filler is calcium carbonate, magnesium carbonate, calcium sulfate, magnesium sulfate, fly ash, clay, talcum powder, mica powder, One or more mixtures of kaolin, titanium dioxide, chalk or magnesia powder. 3. The highly filled fully biodegradable packaging material according to claim 1, characterized in that said biodegradable polymer is polybutylene succinate, polylactic acid, polyglycolide, polycaprolactone, One or more mixtures of starch and polyvinyl alcohol. 4. The highly filled fully biodegradable packaging material according to claim 1, characterized in that said coupling agent is mainly titanium-based coupling agent, aluminum-based coupling agent, and aluminum-titanium composite coupling agent. 5. The highly filled fully biodegradable packaging material according to claim 1, characterized in that the plasticizer used is polyols or citric acid esters, and the polyols can be ethylene glycol, glycerol, sorbitol; Citrates may be tributyl citrate (TBC), trioctyl citrate (TOC), acetyl tributyl citrate (ATBC), acetyl trioctyl citrate (ATOC). 6. The preparation method of highly filled fully biodegradable packaging material according to claim 1, characterized in that the method comprises the steps: Step 1: Crush the filler, take a particle size of 1000-2500 mesh, and dry it in a dryer at a temperature of 100-200°C until the water content is ≤0.5%; Step 2: Stir the filler in step 1 and the coupling agent in a set ratio in a high-speed mixer, heat to activate, mix for 10-20min, and the temperature is 80-120°C; Step 3: Mix the activated filler, biodegradable polymer, and plasticizer in the high-speed mixer according to the set ratio in step 2; Step 4 Extrude and granulate the mixture in step 3 with an extruder, and the extrusion temperature is 150-200°C.