KR20090008117A - Biodegradable Base Resin Composition Using Biodegradable Polymer and Fine Calcium Carbonate and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a biodegradable base resin composition prepared using ultra-fine calcium carbonate, a biodegradable polymer, starch, a plasticizer, a lubricant, a compatibilizer, based on fine calcium carbonate, and 5 to 50% by weight of fine calcium carbonate, 5 to 40% by weight ultrafine calcium carbonate, 5 to 60% by weight biodegradable polymer, 5 to 50% by weight starch, 1 to 15% by weight plasticizer, 0.1 to 20% by weight lubricant, 0.005 to 5% by weight compatibilizer It is characterized by. In the case of the existing biodegradable composition, in addition to the disadvantages of low heat resistance, productivity, and moldability, there is a limit in the industrial availability due to the excessively expensive and incompatible with other polymers. The biodegradable base resin composition according to the present invention can be produced by controlling the desired physical properties, strength, price, etc. of the finished packaged product by simply mixing the biodegradable polymer resin with a suitable ratio and other properties when producing the finished product. Packaging finished products are virtuous in their natural state and rot and return to nature without straining the environment.

Description

Biodegradable base resin composition using biodegradable polymer and fine calcium carbonate and manufacturing method thereof

The present invention relates to a biodegradable base resin composition, 5 to 50% by weight of fine calcium carbonate, 5 to 40% by weight of ultrafine calcium carbonate, 5 to 60% by weight of biodegradable polymer, 5 to 50% by weight of starch, 1 to 1 plasticizer 15 wt%, 0.1-20 wt% of lubricant, 0.005-5 wt% of compatibilizer. Existing biodegradable resin composition provides a more competitive biodegradable base resin composition by compensating for the disadvantages of lack of industrial availability due to lack of heat resistance, productivity, moldability, water resistance, and lack of price competitiveness. The biodegradable base resin composition according to the present invention can be produced by controlling the desired physical properties, strength, price, etc. of the finished packaged product by simply mixing the biodegradable polymer resin with a suitable ratio and other properties when producing the finished product. Packaging finished products are virtuous in their natural state and rot and return to nature without straining the environment.

The biodegradable base resin composition according to the present invention may be used as a raw material for food containers, industrial packaging materials, agricultural and horticultural packaging materials according to general production methods such as sheet production, vacuum molding, pressure vacuum, injection molding, and the like. In addition, properties of the existing biodegradable eco-packaging products are expected to improve properties, reduce cost, incineration, and improve productivity. The finished product packaging material is structurally stable, but has surface improvement effects, strength increase, and polymer compatibility. Biodegradable polymer used in the present invention as a fine calcium carbonate, a composition using a compatibilizer is excellent in compatibility with a variety of polymer materials, raw materials for film and vinyl extrusion, sheet molding, vacuum molding, vacuum molding, injection molding products There is an advantage that can be applied to various.

    Polymer materials such as plastics have made great contributions to modern people's abundant daily life and industrial development with diverse, water resistance, excellent physical properties and low price, while environment caused by incineration or landfill of various waste vinyl, styrofoam, plastic containers, etc. It is emerging as a cause of serious environmental pollution such as hormonal leakage and air pollution caused by incomplete combustion of toxic dioxin detection waste.

    In order to solve the problem of the plastic waste, while maintaining the processability, durability, and mechanical properties of the plastic, in addition to the decomposability, the research has been conducted to solve the convenience and environmental pollution problems of plastics.

        Recently, in the case of plastic products, such as disposable food containers, garbage bags, and buffers for packaging commercial products, except for products that require reflection, new eco-friendly degradable polymer materials that can be decomposed within a short period of time are used. As research to utilize as substitute material is actively conducted, its use is expanding and new new materials are actively developed. In particular, the price of crude oil derived from fossil fuels has risen sharply and worries about the depletion of petroleum resources, global warming, carbon dioxide reduction, and environmental pollution are required. In the case of previously developed biodegradable materials, further research and development through the increase of physical properties, cost reduction, and similar eco-friendly materials and blending and compound are very active. In addition to reducing use and developing alternative materials, the importance of resource saving through recycling and reuse is becoming more important.

Biodegradable materials developed as substitutes for petroleum resources previously developed include chitin, chitosan, alginic acid, collagen, bacterial cellulose, and polyamino acids. Also derived from microorganisms or chemically synthesized, polylactic acid (PLA), polyhydroxybutyrate valerate (PHBV), polycaprolactone (PCL), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polyhydrate Aliphatic polyesters (AP) such as oxyalkanoate (PHA) and the like have been developed and marketed. However, there is a disadvantage that the price is expensive, there is a price resistance of the existing consumer, and also heat resistance, processability, productivity is poor, the situation is not actively applied in the actual industrial field. Accordingly, various efforts have been made to improve the properties, formability, and processability of existing biodegradable materials by using two or more existing biodegradable materials in combination or developing new biodegradable materials. Biodegradable raw materials that have been developed so far have weaknesses that are easily damaged due to their weak physical properties. Also, due to the high cost of raw materials, the economic efficiency is lowered, and the cooling time is long after production. There are disadvantages.

      In order to solve these problems, various researches using materials other than PLA and expensive aliphatic polyester, which are deformed even in hot water, have been conducted in various ways. It could not solve the easy-cut phenomenon that is easily torn in the direction of the time pattern, there was a weak product properties. Korean Patent Application No. 10-2005-0032965 denatures corn starch and uses inorganic fillers, but the manufacturing process is complicated. Korean Patent Application No. 10-2002-0058408 mainly uses starch and fibrous materials to enhance strength. In addition, Korean patent application 10-2007-0089849, which the inventors have selected, also has a disadvantage that is still expensive, and thus has a disadvantage in that the industrial application is inferior.

It is to solve the problem that the industrial applicability of the existing biodegradable resin composition is lowered due to the deterioration of product moldability, heat resistance, productivity reduction, and expensiveness. It can reduce the cost of the product, give heat resistance through the modification of the properties of starch, and greatly improve the compatibility of the fatty-based aliphatic polyesters to provide a very improved product properties and low-cost biodegradable base resin composition Has its purpose. Another object of the present invention is to use the same as the master batch to produce a finished product by simply mixing the raw material and the biodegradable base resin of the present invention before producing the finished product packaging material without compounding with various polymer materials. It is an object of the present invention to provide a biodegradable base resin composition which can easily achieve a desired purpose such as cost reduction, supplementation of finished product strength, and physical property control by providing a biodegradable base resin composition. It is another object of the present invention to provide a method for preparing a biodegradable base resin composition.

This object of the present invention is achieved by the method of the present invention comprising the following steps:

        Starch, plasticizer, ultrafine calcium carbonate, fine calcium carbonate, lubricant, and compatibilizer, which are inorganic fillers, are added to a mixer and mixed at 500 to 1,500 rpm to remove moisture and mix;

Adding the biodegradable polymer, which serves as a binder of the powder raw material of the first step, into the mixture of the first step, and then mixing at 500 to 1,500 rpm;

After completing the mixing process, the material is put into the hopper, and then one or more kneading zones and one or more reverse screws are installed, and water and volatile substances that can be generated during processing of powder raw materials are discharged. Three steps of discharging the raw material produced by kneading, mixing, and thermochemical modification by processing at a processing temperature of 100 to 230 degrees while passing through a conventional twin extruder having one or more vent holes installed therein;

The biodegradable base raw material strand discharged through the die is cut to prepare a biodegradable base resin composition using pellet-shaped biodegradable polymer and fine calcium carbonate.

In general, a method of cutting raw material strands into pellets is generally carried out by blow-drying a raw material discharged through a die after face cutting, or by cutting and drying the blown strand while transferring the discharged strand through a conveyor belt, or by using a gala system. In addition, the strand may be manufactured in a pellet form by a general cutting method of cutting the surface after passing the strand through a water bath.

        In the present invention, the amount of each raw material used is 5 to 50% by weight of fine calcium carbonate, 5 to 40% by weight of ultra fine calcium carbonate, 5 to 60% by weight of biodegradable polymer, 5 to 50% by weight of starch, and 1 to 15% by weight of plasticizer. %, Lubricant 0.1 to 20% by weight, compatibilizer 0.005 to 5% by weight.

        The micro-grade fine calcium carbonate according to the present invention may be used having a particle diameter of 3 to 100㎛, when using only ultra-fine calcium carbonate, the calcium carbonate is agglomerated by a strong self-cohesive force to adversely affect the finished product packaging material do. For example, disadvantages such as deterioration of surface condition, lowering of dimensional stability, lowering of elastic modulus of elasticity, lowering of physical properties such as strength and lowering of productivity are increased. The amount of fine calcium carbonate may be 5 to 70% by weight, preferably 5 to 50% by weight based on the total weight of the composition.

       The nano-grade ultra-fine calcium carbonate according to the present invention uses a particle size of 50 to 200 nm, the amount may be 3.0 to 70% by weight, preferably 5.0 to 50% by weight based on the total weight of the composition. . The ultra fine calcium carbonate forms a bond with the monomer of the high molecular material, and the ultra fine particles fill the void space between the polymers, thereby improving physical properties such as strength and improving the surface. When it is used at less than 3.0% by weight, it is difficult to expect the effects of product compatibility, surface modification, and physical property increase when applied to the finished product packaging material, and when it is used at more than 50% by weight, productivity decreases, cost increases, and materials aggregate. It will adversely affect the properties of the biodegradable base resin composition such as development. In the case of using such ultrafine calcium carbonate, the surface area is increased by the ultrafine particles and the proportion of ions placed on the surface is increased. Therefore, it plays a very large role in the physical properties of the polymer such as bonding strength, cohesion, and the like, a remarkable effect of physical properties improvement, surface modification, strength increase.

        The biodegradable polymer according to the present invention is polyhydroxybutyrate valerate (PHBV), polycaprolactone (PCL), polybutylene succinate (PBS), polylactic acid (PLA), polyhydroxybutyrate (PHB), poly Hydroxyalkanoate (PHA), aliphatic polyester, and starch resin can be used alone or in combination. This is to act as a binder between the raw materials is to play an important role in the formation of pellets by improving the binding force between the raw materials of the composition, the higher the Melt Index (MI) is more convenient for use. The amount used may be 3.0 to 70% by weight, preferably 5.0 to 50% by weight. If it is added less than 5% by weight, it is difficult to form pellets by weakening the binding force, there is no particular problem when using more than 50% by weight, but there is a disadvantage that the product cost increases.

The starch according to the present invention is a starch commonly used in the art, for example, starch extracted from various plants such as corn, potato, tapioca, sweet potato, wheat, rice and grains. Starch is divided into ground starch and underground starch according to the type of plant and storage area. Each starch has different shape, particle size, and unique characteristics of starch particle shape, particle size, and appearance, and there are many differences in physicochemical properties according to varieties. In many cases, one or more mixtures selected from the group consisting of corn starch, tapioca starch and wheat starch were used as raw starch in the present invention. The amount used may be 5.0 to 70% by weight, preferably 5 to 50% by weight based on the total weight of the composition. There is no particular problem when the starch is used more than 50%, but the cost of the calcium carbonate is lowered and the cost is increased.

        The plasticizer according to the present invention may be used alone or in combination with glycerin, glycerol monostearate (GMS), sorbitol, the amount of the use may be 0.5 to 30% by weight, preferably 1 to 15% by weight. The plasticizer has an effect of improving the fluidity and processability of the starch, and has a disadvantage in that it is eluted to the surface when used in excess. The plasticizer is used for the purpose of denaturing starch. When the plasticizer is added to the polymer material, the blend is increased in flexibility, elasticity and warpage, thereby improving workability and formability. Polymeric material such as starch itself is not easily deformed due to its large molecular weight, but plasticity can be easily deformed by external force. Thermoplastic plastics are called thermoplastics. In the present invention, starch is plasticized to impart thermoplasticity to the carbonized starch when heat is applied.

        The lubricant according to the present invention is calcium stearate, zinc stearate, glycerin stearate, butyl stearate, solid paraffin wax, liquid paraffin wax, beeswax, drive wax, emulsion wax, candelilla wax, paraffin, liquid paraffin. It may be used alone or in combination, the amount thereof may be 0.2 to 20% by weight, preferably 0.5 to 15% by weight. Lubricants have a disadvantage in that the cost of materials increases when using behenic acid series with 22 carbon atoms, which have good lubrication effects. There is an advantage in In addition, when using a fatty acid-based lubricant, there is an advantage in showing the affinity to the inorganic material, such as filler, there is an advantage that the surface is modified by coating a hydrophilic inorganic material. Lubricants are additives that are used to literally reduce and smooth the friction between raw materials. Not all frictions are bad, but the heat of friction during mixing, melting, and processing of the raw materials causes the raw materials to be heated and decomposed more than necessary, carbonizing organic additives such as starch in the raw materials, and It is used to eliminate the occurrence of defects by pressing on the surface.

The compatibilizer according to the present invention may be used alone or mixed with benzoyl peroxide, polyvinyl alcohol (PVA), benzophenone, the amount of the amount may be 0.001 to 1% by weight, preferably 0.005 to 2% by weight. The compatibilizer is present at the interface between the raw materials due to the interfacial action between the raw materials used, thereby lowering the interfacial tension, and improving the compatibility between the raw materials by improving the reactivity between the raw materials. Improve the defective rate, lowering the physical properties

The biodegradable base resin composition prepared according to the present invention is compatible with the biodegradable polymer, so that no problems were found in preparing the eco-packaging finished product, and the productivity of the product was excellent and the product strength was increased. In addition, by using the biodegradable base resin composition of the present invention can be easily mixed with a variety of polymers to produce a biodegradable finished product of various physical properties it is easy to produce and supply a product of the physical properties desired by the buyer in a simple way. As the product of the present invention is applied to industrialization, there is an advantage in that it is easily decomposed in the natural state to increase soil organic matter and does not pollute the environment. By using the biodegradable base resin composition of the present invention there is an advantage that can be used as a production machine in the existing production site as it is, it is possible to achieve a cost reduction of expensive biodegradable polymer is very high industrial applicability.

The biodegradable base resin composition according to the present invention is mixed using a mixer such as a conventional Henschel mixer, a super mixer, and has a size of about 2-8 mm through a melt extrusion process using a conventional twin extruder. It is made into a pellet state having. The conventional polymer resin and the additive composition required according to the use can be molded into a product to be prepared by mixing immediately. Alternatively, the required thermoplastic polymer resin and the other components may be mixed in an appropriate ratio according to the use to prepare a compound beforehand to prepare a desired product. Packaging materials that can be manufactured can be manufactured in a variety of known forms such as films, vinyl, sheets, vacuum molded products, injection molded products. Such biodegradable base resin composition is suitably prepared to the extent that it can be mixed and used in a ratio of about 5% to 75% with respect to the total weight of the conventional polymer resin, but the present invention is not limited thereto.

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples are intended to illustrate the invention and are not intended to limit the invention thereto.

<Example 1>

        28 wt% of fine calcium carbonate, 25 wt% of ultra fine calcium carbonate, 15 wt% of corn starch, 2 wt% of sorbitol, 2 wt% of zinc stearate, 1.97 wt% of pywax, and 0.03 wt% of benzoyl peroxide were added to the mixer and 1,000 rpm. Moisture removal and mixing. 10% by weight of PBS and 16% by weight of PCL were further added to the mixer, and the mixture was further mixed at 800 rpm. After completing the mixing process, the material is put into the hopper, and then one or more kneading zones and one or more reverse screws are installed, and water and volatile substances that can be generated during processing of powder raw materials are discharged. Strand through which the raw material, which is kneaded, mixed and thermochemically modified, is discharged through the die by processing at a processing temperature of 175 ° C and a screw 950 rpm while passing through a conventional twin extruder equipped with one or more vent holes. Was cut to prepare a biodegradable base resin composition.

<Example 2>

        60 wt% of the biodegradable base resin composition prepared in Example 1, 20 wt% of PCL, and 20 wt% of PBS were mixed to prepare a sheet using a conventional sheet extruder.

<Example 3>

        Using the sheet prepared in Example 2, a vacuum molded article was manufactured using a conventional vacuum molding machine.

<Example 4>

        60 wt% of the biodegradable base resin composition prepared in Example 1, 20 wt% PLA, and 20 wt% of starch resin were mixed to prepare an injection molded article in a conventional injection molding machine.

<Example 5>

        Injection molded articles were manufactured in a conventional injection molding machine using 100 wt% of the biodegradable base resin composition prepared in Example 1.

<Example 6>

        60 wt% of the biodegradable base resin composition prepared in Example 1, 20 wt% of PCL, and 20 wt% of PBS were mixed to prepare a film using a conventional film extruder.

Claims (7)

        5 to 50% by weight of fine calcium carbonate having a particle diameter of 3 to 100 µm, 5 to 40% by weight of ultrafine calcium carbonate having a particle size of 50 to 900 nm, 5 to 60% by weight of biodegradable polymer, 5 to 50% by weight of starch, plasticizer 1 to 15% by weight, 0.1 to 20% by weight of lubricant, 0.005 to 5% by weight of compatibilizer is prepared in pellet form having a size of about 2-8mm using a conventional single or twin extruder Biodegradable base resin composition using biodegradable polymer and fine calcium carbonate The method of claim 1, wherein the biodegradable polymer is polyhydroxybutyrate valerate (PHBV), polycaprolactone (PCL), polybutylene succinate (PBS), polylactic acid (PLA), polyhydroxybutyrate (PHB ), Polyhydroxyalkanoate (PHA), aliphatic polyester, biodegradable base resin composition using a biodegradable polymer and fine calcium carbonate, characterized in that one or two or more selected from starch resins The biodegradable base using biodegradable polymer and fine calcium carbonate according to claim 1, wherein the starch is at least one selected from corn starch, tapioca starch, wheat starch, potato starch, sweet potato starch and rice starch. Resin Composition The biodegradable base resin composition using biodegradable polymer and fine calcium carbonate according to claim 1, wherein the plasticizer is one or two or more selected from glycerin, glycerol monostearate (GMS) and sorbitol. The method of claim 1, wherein the lubricant is calcium stearate, zinc stearate, glycerin stearate, butyl stearate, solid paraffin wax, liquid paraffin wax, beeswax, drive wax, emulsion wax, candelilla wax, paraffin, liquid Biodegradable base resin composition using biodegradable polymer and fine calcium carbonate, characterized in that one or two or more selected from paraffins The biodegradable base resin composition using biodegradable polymer and fine calcium carbonate according to claim 1, wherein the compatibilizer is one or two or more selected from benzoyl peroxide, polyvinyl alcohol (PVA), and benzophenone.         Starch, plasticizer, ultrafine calcium carbonate, fine calcium carbonate, lubricant, and compatibilizer, which are inorganic fillers, are added to a mixer and mixed at 500 to 1,500 rpm to remove water and mix; Adding the biodegradable polymer, which serves as a binder of the powder raw material of the first step, into the mixture of the first step, and then mixing at 500 to 1,500 rpm; After completing the mixing process, the material is put into the hopper, and then one or more kneading zones and one or more reverse screws are installed, and water and volatile substances that can be generated during processing of powder raw materials are discharged. Three steps of discharging the raw material produced by kneading, mixing, and thermochemical modification by processing at a processing temperature of 100 to 230 degrees while passing through a conventional twin extruder having one or more vent holes installed therein; Method for producing a biodegradable base resin composition using a biodegradable polymer and fine calcium carbonate, characterized in that it comprises four steps of cutting the biodegradable base raw material strand discharged through a die into a pellet shape